A component-based software configuration management model and its supporting system Software configuration management -LRB- SCM -RRB- is an important key technology in software development . Component-based software development -LRB- CBSD -RRB- is an emerging paradigm in software development . However , to apply CBSD effectively in real world practice , supporting SCM in CBSD needs to be further investigated . In this paper , the objects that need to be managed in CBSD is analyzed and a component-based SCM model is presented . In this model , components , as the integral logical constituents in a system , are managed as the basic configuration items in SCM , and the relationships between/among components are defined and maintained . Based on this model , a configuration management system is implemented

O O O O O O O O O O O O O O O O O O O O O O B I O O B I O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

software development
integral logical constituents


Mammogram synthesis using a 3D simulation . II . Evaluation of synthetic mammogram texture We have evaluated a method for synthesizing mammograms by comparing the texture of clinical and synthetic mammograms . The synthesis algorithm is based upon simulations of breast tissue and the mammographic imaging process . Mammogram texture was synthesized by projections of simulated adipose tissue compartments . It was hypothesized that the synthetic and clinical texture have similar properties , assuming that the mammogram texture reflects the 3D tissue distribution . The size of the projected compartments was computed by mathematical morphology . The texture energy and fractal dimension were also computed and analyzed in terms of the distribution of texture features within four different tissue regions in clinical and synthetic mammograms . Comparison of the cumulative distributions of the mean features computed from 95 mammograms showed that the synthetic images simulate the mean features of the texture of clinical mammograms . Correlation of clinical and synthetic texture feature histograms , averaged over all images , showed that the synthetic images can simulate the range of features seen over a large group of mammograms . The best agreement with clinical texture was achieved for simulated compartments with radii of 4-13 .3 mm in predominantly adipose tissue regions , and radii of 2.7-5 .33 and 1.3-2 .7 mm in retroareolar and dense fibroglandular tissue regions , respectively

B I O O B I O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O B I O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I O O

mammogram synthesis
3d simulation
synthetic mammogram texture
adipose tissue compartments
3d tissue distribution
mathematical morphology
fractal dimension
cumulative distributions
synthetic images
dense fibroglandular tissue regions

breast tissue simulation
retroareolar tissue regions
x-ray image acquisition
computationally compressed phantom


An effective feedback control mechanism for DiffServ architecture As a scalable QoS -LRB- Quality of Service -RRB- architecture , Diffserv -LRB- Differentiated Service -RRB- mainly consists of two components : traffic conditioning at the edge of the Diffserv domain and simple packet forwarding inside the DiffServ domain . DiffServ has many advantages such as flexibility , scalability and simplicity . But when providing AF -LRB- Assured Forwarding -RRB- services , DiffServ has some problems such as unfairness among aggregated flows or among micro-flows belonging to an aggregated flow . In this paper , a feedback mechanism for AF aggregated flows is proposed to solve this problem . Simulation results show that this mechanism does improve the performance of DiffServ . First , it can improve the fairness among aggregated flows and make DiffServ more friendly toward TCP -LRB- Transmission Control Protocol -RRB- flows . Second , it can decrease the buffer requirements at the congested router and thus obtain lower delay and packet loss rate . Third , it also keeps almost the same link utility as in normal DiffServ . Finally , it is simple and easy to be implemented

O O B I O O B O O O O B O O O O O O O B O O O O O O O O O O B I O O O O O B O O O B I O O B O O B O O O O O O O O O O O O O O B O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O B I O B O O O O O O O O O O O O O O O O O O O O B O O O O O O O B O O O O O B O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O

qos
diffserv
traffic conditioning
packet forwarding
af
feedback mechanism
fairness
tcp
feedback control


New age computing -LSB- autonomic computing -RSB- Autonomic computing -LRB- AC -RRB- , sometimes called self-managed computing , is the name chosen by IBM to describe the company 's new initiative aimed at making computing more reliable and problem-free . It is a response to a growing realization that the problem today with computers is not that they need more speed or have too little memory , but that they crash all too often . This article reviews current initiatives being carried out in the AC field by the IT industry , followed by key challenges which require to be addressed in its development and implementation

B I I O B I O B I O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O

autonomic computing
new age computing
ac

self-managed computing
ibm initiative
computing reliability
problem-free computing
computer speed
computer memory
computer crash
it industry initiatives
ac requirements
ac development
ac implementation
open standards
self-healing computing
adaptive algorithms


Repeated games with lack of information on one side : the dual differential approach We introduce the dual differential game of a repeated game with lack of information on one side as the natural continuous time version of the dual game introduced by De Meyer -LRB- 1996 -RRB- . A traditional way to study the value of differential games is through discrete time approximations . Here , we follow the opposite approach : We identify the limit value of a repeated game in discrete time as the value of a differential game . Namely , we use the recursive structure for the finitely repeated version of the dual game to construct a differential game for which the upper values of the uniform discretization satisfy precisely the same property . The value of the dual differential game exists and is the unique viscosity solution of a first-order derivative equation with a limit condition . We identify the solution by translating viscosity properties in the primal

B I O O O O O O O O O O O O O O O B I I O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O B I O O B I O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O B I O O O O O O O B I O O O O O O O O O O O O

repeated games
dual differential game
repeated game
discrete time approximations
limit value
discrete time
viscosity solution
limit condition


An attack-finding algorithm for security protocols This paper proposes an automatic attack construction algorithm in order to find potential attacks on security protocols . It is based on a dynamic strand space model , which enhances the original strand space model by introducing active nodes on strands so as to characterize the dynamic procedure of protocol execution . With exact causal dependency relations between messages considered in the model , this algorithm can avoid state space explosion caused by asynchronous composition . In order to get a finite state space , a new method called strand-added on demand is exploited , which extends a bundle in an incremental manner without requiring explicit configuration of protocol execution parameters . A finer granularity model of term structure is also introduced , in which subterms are divided into check subterms and data subterms . Moreover , data subterms can be further classified based on the compatible data subterm relation to obtain automatically the finite set of valid acceptable terms for an honest principal . In this algorithm , terms core is designed to represent the intruder 's knowledge compactly , and forward search technology is used to simulate attack patterns easily . Using this algorithm , a new attack on the Dolve-Yao protocol can be found , which is even more harmful because the secret is revealed before the session terminates

O O O O B I O O O O O O O O O O O O O O O B I O O O O O O B I I I O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O B I O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

security protocols
dynamic strand space model
strand space model
state space explosion
asynchronous composition
check subterms
data subterms

attack-finding algorithm
strand-added on demand
dolve-yao protocol


Revisiting Hardy 's paradox : Counterfactual statements , real measurements , entanglement and weak values Hardy 's -LRB- 1992 -RRB- paradox is revisited . Usually the paradox is dismissed on grounds of counterfactuality , i.e. , because the paradoxical effects appear only when one considers results of experiments which do not actually take place . We suggest a new set of measurements in connection with Hardy 's scheme , and show that when they are actually performed , they yield strange and surprising outcomes . More generally , we claim that counterfactual paradoxes point to a deeper structure inherent to quantum mechanics

O O O O O B I O B I O B O B I O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I

counterfactual statements
real measurements
entanglement
weak values
paradoxical effects
quantum mechanics


Mammogram synthesis using a 3D simulation . I. Breast tissue model and image acquisition simulation A method is proposed for generating synthetic mammograms based upon simulations of breast tissue and the mammographic imaging process . A computer breast model has been designed with a realistic distribution of large and medium scale tissue structures . Parameters controlling the size and placement of simulated structures -LRB- adipose compartments and ducts -RRB- provide a method for consistently modeling images of the same simulated breast with modified position or acquisition parameters . The mammographic imaging process is simulated using a compression model and a model of the X-ray image acquisition process . The compression model estimates breast deformation using tissue elasticity parameters found in the literature and clinical force values . The synthetic mammograms were generated by a mammogram acquisition model using a monoenergetic parallel beam approximation applied to the synthetically compressed breast phantom

B I O O B I O O B I I O B I I O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O B I O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O B I O O O O O O O O O O O O O B I I I O O O O O O O

mammographic compression
x-ray image acquisition
breast lesions
rectangular slice approximation
composite beam model
linear young's moduli


Fast and accurate leaf verification for dynamic multileaf collimation using an electronic portal imaging device A prerequisite for accurate dose delivery of IMRT profiles produced with dynamic multileaf collimation -LRB- DMLC -RRB- is highly accurate leaf positioning . In our institution , leaf verification for DMLC was initially done with film and ionization chamber . To overcome the limitations of these methods , a fast , accurate and two-dimensional method for daily leaf verification , using our CCD-camera based electronic portal imaging device -LRB- EPID -RRB- , has been developed . This method is based on a flat field produced with a 0.5 cm wide sliding gap for each leaf pair . Deviations in gap widths are detected as deviations in gray scale value profiles derived from the EPID images , and not by directly assessing leaf positions in the images . Dedicated software was developed to reduce the noise level in the low signal images produced with the narrow gaps . The accuracy of this quality assurance procedure was tested by introducing known leaf position errors . It was shown that errors in leaf gap as small as 0.01-0 .02 cm could be detected , which is certainly adequate to guarantee accurate dose delivery of DMLC treatments , even for strongly modulated beam profiles . Using this method , it was demonstrated that both short and long term reproducibility in leaf positioning were within 0.01 cm -LRB- 1 sigma -RRB- for all gantry angles , and that the effect of gravity was negligible

O O B I I O B I I O O B I I I O O O B I I O O O O O B I I O O O O O O B I O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O B I I I O O O O O O O O O O O O O O O O O O O O O O B I O O B I O O O B I O O O O O B I I I O O O O O O O O O O O O O O O O O O O O O O O O B I O O O B I O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O B I I O O O O O O O O O O O O O O O O B I O O O O O O O O O O B I O O O O O O O O O

accurate leaf verification
dynamic multileaf collimation
electronic portal imaging device
accurate dose delivery
ionization chamber
sliding gap
leaf pair
gap widths
gray scale value profiles
noise level
signal images
leaf position errors
modulated beam profiles
leaf positioning
gantry angles

intensity modulated radiation therapy profiles

ccd-camera based electronic portal imaging device


Virtual projects at Halden -LSB- Reactor Project -RSB- The Halden man-machine systems -LRB- MMS -RRB- programme for 2002 is intended to address issues related to human factors , control room design , computer-based support system areas and system safety and reliability . The Halden MMS programme is intended to address extensive experimental work in the human factors , control room design and computer-based support system areas . The work is based on experiments and demonstrations carried out in the experimental facility HAMMLAB . Pilot-versions of several operator aids are adopted and integrated to the HAMMLAB simulators and demonstrated in a full dynamic setting . The Halden virtual reality laboratory has recently become an integral and important part of the programme

O O O O O O O O O O O O O O O O O O O O O O O O O B I O B I I O O O O O O O B O B O O O O O O O O O O O O O O B I O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O

human factors
safety
reliability
virtual reality
control room design

halden reactor project
man-machine systems programme
computer-based support system


Evaluation of existing and new feature recognition algorithms . 2 . Experimental results For pt .1 see ibid. , p.839-851 . This is the second of two papers investigating the performance of general-purpose feature detection techniques . The first paper describes the development of a methodology to synthesize possible general feature detection face sets . Six algorithms resulting from the synthesis have been designed and implemented on a SUN Workstation in C++ using ACIS as the geometric modelling system . In this paper , extensive tests and comparative analysis are conducted on the feature detection algorithms , using carefully selected components from the public domain , mostly from the National Design Repository . The results show that the new and enhanced algorithms identify face sets that previously published algorithms can not detect . The tests also show that each algorithm can detect , among other types , a certain type of feature that is unique to it . Hence , most of the algorithms discussed in this paper would have to be combined to obtain complete coverage

O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

feature recognition algorithms
national design repository
face sets


The contiguity in R/M An r.e. degree c is contiguous if deg/sub wtt / -LRB- A -RRB- = deg/sub wtt / -LRB- B -RRB- for any r.e. sets A , B in c . In this paper , we generalize the notation of contiguity to the structure R/M , the upper semilattice of the r.e. degree set R modulo the cappable r.e. degree set M . An element -LSB- c -RSB- in R/M is contiguous if -LSB- deg/sub wtt / -LRB- A -RRB- -RSB- = -LSB- deg/sub wtt / -LRB- B -RRB- -RSB- for any r.e. sets A , B such that deg/sub T / -LRB- A -RRB- , deg/sub T / -LRB- B -RRB- in -LSB- c -RSB- . It is proved in this paper that every nonzero element in R/M is not contiguous , i.e. , for every element -LSB- c -RSB- in R/M , if -LSB- c -RSB- not = -LSB- o -RSB- then there exist at least two r.e. sets A , B such that deg/sub T / -LRB- A -RRB- , deg/sub T / -LRB- B -RRB- in -LSB- c -RSB- and -LSB- deg/sub wtt / -LRB- A -RRB- -RSB- not = -LSB- deg/sub wtt / -LRB- B -RRB- -RSB-

O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

contiguity
upper semilattice
nonzero element

turing degree
recursively enumerable set
recursion theory


Quantum limit on computational time and speed We investigate if physical laws can impose limits on computational time and speed of a quantum computer built from elementary particles . We show that the product of the speed and the running time of a quantum computer is limited by the type of fundamental interactions present inside the system . This will help us to decide as to what type of interaction should be allowed in building quantum computers in achieving the desired speed

B I O B I O O O O O O O O O O O B I O O O O B I O O O O O O O O O O O O O O O O O O O B I O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

quantum limit
computational time
quantum computer
fundamental interactions


A knowledge-navigation system for dimensional metrology Geometric dimensioning and tolerancing -LRB- GD&T -RRB- is a method to specify the dimensions and form of a part so that it will meet its design intent . GD&T is difficult to master for two main reasons . First , it is based on complex 3D geometric entities and relationships . Second , the geometry is associated with a large , diverse knowledge base of dimensional metrology with many interconnections . This paper describes an approach to create a dimensional metrology knowledge base that is organized around a set of key concepts and to represent those concepts as virtual objects that can be navigated with interactive , computer visualization techniques to access the associated knowledge . The approach can enable several applications . First is the application to convey the definition and meaning of GD&T over a broad range of tolerance types . Second is the application to provide a visualization of dimensional metrology knowledge within a control hierarchy of the inspection process . Third is the application to show the coverage of interoperability standards to enable industry to make decisions on standards development and harmonization efforts . A prototype system has been implemented to demonstrate the principles involved in the approach

O O O O B I B I O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O B I O O O O O O O B O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O

geometric dimensioning
tolerancing
dimensional metrology
visualization
interoperability standards
inspection

knowledge navigation
manufacturing training
vrml
web


The semi-algebraic theory of stochastic games The asymptotic behavior of the min-max value of a finite-state zero-sum discounted stochastic game , as the discount rate approaches 0 , has been studied in the past using the theory of real-closed fields . We use the theory of semi-algebraic sets and mappings to prove some asymptotic properties of the min-max value , which hold uniformly for all stochastic games in which the number of states and players ' actions are predetermined to some fixed values . As a corollary , we prove a uniform polynomial convergence rate of the value of the N-stage game to the value of the nondiscount game , over a bounded set of payoffs

O O O O O O O B I O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I O O O O O O O O O O O O O O O O O O O O O

asymptotic behavior
discount rate
uniform polynomial convergence rate

two-player zero-sum finite-state stochastic games


Reproducibility of mammary gland structure during repeat setups in a supine position Purpose : In breast conserving therapy , complete excision of the tumor with an acceptable cosmetic outcome depends on accurate localization in terms of both the position of the lesion and its extent . We hypothesize that preoperative contrast-enhanced magnetic resonance -LRB- MR -RRB- imaging of the patient in a supine position may be used for accurate tumor localization and marking of its extent immediately prior to surgery . Our aims in this study are to assess the reproducibility of mammary gland structure during repeat setups in a supine position , to evaluate the effect of a breast immobilization device , and to derive reproducibility margins that take internal tissue shifts into account occurring between repeat setups . Materials Methods : The reproducibility of mammary gland structure during repeat setups in a supine position is estimated by quantification of tissue shifts in the breasts of healthy volunteers between repeat MR setups . For each volunteer fiducials are identified and registered with their counter locations in corresponding MR volumes . The difference in position denotes the shift of breast tissue . The dependence on breast volume and the part of the breast , as well as the effect of a breast immobilization cast are studied . Results : The tissue shifts are small with a mean standard deviation on the order of 1.5 mm , being slightly larger in large breasts -LRB- V > 1000 cm/sup 3 / -RRB- , and in the posterior part -LRB- toward the pectoral muscle -RRB- of both small and large breasts . The application of a breast immobilization cast reduces the tissue shifts in large breasts . A reproducibility margin on the order of 5 mm will take the internal tissue shifts into account that occur between repeat setups . Conclusion : The results demonstrate a high reproducibility of mammary gland structure during repeat setups in a supine position

O O O O O O B I O O B I O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O B I O O B I O O O O O O O B I I O O O O B I O O B I I O O O O B I O O O O O O O O O O O B I O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O B I O O O O O O O O O O O O O O B I O O B I

repeat setups
supine position
breast conserving therapy
accurate tumor localization
breast immobilization device
reproducibility margins
internal tissue shifts

contrast-enhanced magnetic resonance imaging


Development and evaluation of a case-based reasoning classifier for prediction of breast biopsy outcome with BI-RADS/sup TM / lexicon Approximately 70-85 % of breast biopsies are performed on benign lesions . To reduce this high number of biopsies performed on benign lesions , a case-based reasoning -LRB- CBR -RRB- classifier was developed to predict biopsy results from BI-RADS/sup TM / findings . We used 1433 -LRB- 931 benign -RRB- biopsy-proven mammographic cases . CBR similarity was defined using either the Hamming or Euclidean distance measure over case features . Ten features represented each case : calcification distribution , calcification morphology , calcification number , mass margin , mass shape , mass density , mass size , associated findings , special cases , and age . Performance was evaluated using Round Robin sampling , Receiver Operating Characteristic -LRB- ROC -RRB- analysis , and bootstrap . To determine the most influential features for the CBR , an exhaustive feature search was performed over all possible feature combinations -LRB- 1022 -RRB- and similarity thresholds . Influential features were defined as the most frequently occurring features in the feature subsets with the highest partial ROC areas -LRB- / sub 0.90 / AUC -RRB- . For CBR with Hamming distance , the most influential features were found to be mass margin , calcification morphology , age , calcification distribution , calcification number , and mass shape , resulting in an / sub 0.90 / AUC of 0.33 . At 95 % sensitivity , the Hamming CBR would spare from biopsy 34 % of the benign lesions . At 98 % sensitivity , the Hamming CBR would spare 27 % benign lesions . For the CBR with Euclidean distance , the most influential feature subset consisted of mass margin , calcification morphology , age , mass density , and associated findings , resulting in / sub 0.90 / AUC of 0.37 . At 95 % sensitivity , the Euclidean CBR would spare from biopsy 41 % benign lesions . At 98 % sensitivity , the Euclidean CBR would spare 27 % benign lesions . The profile of cases spared by both distance measures at 98 % sensitivity indicates that the CBR is a potentially useful diagnostic tool for the classification of mammographic lesions , by recommending short-term follow-up for likely benign lesions that is in agreement with final biopsy results and mammographer 's intuition

O O O O O O O O O O O B I I O O O O O O O O O O O O O O B I O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O B I I O O O O O O O O O O B I O B I O B I O B I O B I O B I O B I O B I O B I O O B O O O O O B I I O O O O O O O O O O B O O O O O B I O O O O O O O O O O O O O B I O O O O B I O B I O O O O O O O O O O B I O O B I I I O O O O O O O O O O O O O O O O B I O O O O B I O B I O B O B I O B I O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O B I O B I O B O B I O O B I O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O B I O O O O O O O O O O O O

breast biopsy outcome
benign lesions
cbr similarity
euclidean distance measure
calcification distribution
calcification morphology
calcification number
mass margin
mass shape
mass density
mass size
associated findings
special cases
age
round robin sampling
bootstrap
feature combinations
similarity thresholds
feature subsets
highest partial roc areas
influential features
diagnostic tool

receiver operating characteristic analysis


Evaluation of existing and new feature recognition algorithms . 1 . Theory and implementation This is the first of two papers evaluating the performance of general-purpose feature detection techniques for geometric models . In this paper , six different methods are described to identify sets of faces that bound depression and protrusion faces . Each algorithm has been implemented and tested on eight components from the National Design Repository . The algorithms studied include previously published general-purpose feature detection algorithms such as the single-face inner-loop and concavity techniques . Others are improvements to existing algorithms such as extensions of the two-dimensional convex hull method to handle curved faces as well as protrusions . Lastly , new algorithms based on the three-dimensional convex hull , minimum concave , visible and multiple-face inner-loop face sets are described

O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O B I I O O O O B I O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O B I O O O O O O O O O

feature recognition algorithms
geometric models
sets of faces
protrusion faces
national design repository
curved faces
minimum concave


On deciding stability of constrained homogeneous random walks and queueing systems We investigate stability of scheduling policies in queueing systems . To this day no algorithmic characterization exists for checking stability of a given policy in a given queueing system . In this paper we introduce a certain generalized priority policy and prove that the stability of this policy is algorithmically undecidable . We also prove that stability of a homogeneous random walk in L/sub + / / sup d / is undecidable . Finally , we show that the problem of computing a fluid limit of a queueing system or of a constrained homogeneous random walk is undecidable . To the best of our knowledge these are the first undecidability results in the area of stability of queueing systems and random walks in L/sub + / / sup d / . We conjecture that stability of common policies like First-In-First-Out and priority policy is also an undecidable problem

O O O O B I I I O B I O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O B I O O O B I

queueing systems
constrained homogeneous random walks
generalized priority policy
undecidability results
priority policy
undecidable problem

scheduling policy stability
homogeneous random walk stability
fluid limit computation
first-in-first-out policy


A new algebraic modelling approach to distributed problem-solving in MAS This paper is devoted to a new algebraic modelling approach to distributed problem-solving in multi-agent systems -LRB- MAS -RRB- , which is featured by a unified framework for describing and treating social behaviors , social dynamics and social intelligence . A conceptual architecture of algebraic modelling is presented . The algebraic modelling of typical social behaviors , social situation and social dynamics is discussed in the context of distributed problem-solving in MAS . The comparison and simulation on distributed task allocations and resource assignments in MAS show more advantages of the algebraic approach than other conventional methods

O O B I I O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O B I O O O O B I O B I O B I O O O O O O O O O O O O O O O B I O O O O B I O O O O O O O O O O O O O O O O B I I O B I O O O O O O O O O O O O O

algebraic modelling approach
unified framework
social behaviors
social dynamics
social intelligence
distributed task allocations
resource assignments

distributed problem-solving
multi-agent systems


Benchmarking of the Dose Planning Method -LRB- DPM -RRB- Monte Carlo code using electron beams from a racetrack microtron A comprehensive set of measurements and calculations has been conducted to investigate the accuracy of the Dose Planning Method -LRB- DPM -RRB- Monte Carlo code for dose calculations from 10 and 50 MeV scanned electron beams produced from a racetrack microtron . Central axis depth dose measurements and a series of profile scans at various depths were acquired in a water phantom using a Scanditronix type RK ion chamber . Source spatial distributions for the Monte Carlo calculations were reconstructed from in-air ion chamber measurements carried out across the two-dimensional beam profile at 100 cm downstream from the source . The in-air spatial distributions were found to have full width at half maximum of 4.7 and 1.3 cm , at 100 cm from the source , for the 10 and 50 MeV beams , respectively . Energy spectra for the 10 and 50 MeV beams were determined by simulating the components of the microtron treatment head using the code MCNP4B . DPM calculations are on average within + or-2 % agreement with measurement for all depth dose and profile comparisons conducted in this study . The accuracy of the DPM code illustrated in this work suggests that DPM may be used as a valuable tool for electron beam dose calculations

B O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I B I I O O O B I O B I I I I O O O O B I O O O O O O O B I O O O O O B I O B I I O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O B I O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I

scanned electron beams
racetrack microtron
benchmarking
central axis depth dose measurements
profile scans
water phantom
ion chamber
source spatial distributions
mcnp4b
electron beam dose calculations
50 mev

dose planning method monte carlo code
two-dimensional beam profile
in-air spatial distributions
radiotherapy treatment planning
electron transport
scoring parameters
10 mev


Design and implementation of a reusable and extensible HL7 encoding/decoding framework The Health Level Seven -LRB- HL7 -RRB- , an international standard for electronic data exchange in all health care environments , enables disparate computer applications to exchange key sets of clinical and administrative information . Above all , it defines the standard HL7 message formats prescribed by the standard encoding rules . In this paper , we propose a flexible , reusable , and extensible HL7 encoding and decoding framework using a message object model -LRB- MOM -RRB- and message definition repository -LRB- MDR -RRB- . The MOM provides an abstract HL7 message form represented by a group of objects and their relationships . It reflects logical relationships among the standard HL7 message elements such as segments , fields , and components , while enforcing the key structural constraints imposed by the standard . Since the MOM completely eliminates the dependency of the HL7 encoder and decoder on platform-specific data formats , it makes it possible to build the encoder and decoder as reusable standalone software components , enabling the interconnection of arbitrary heterogeneous hospital information systems -LRB- HIS -RRB- with little effort . Moreover , the MDR , an external database of key definitions for HL7 messages , helps make the encoder and decoder as resilient as possible to future modifications of the standard HL7 message formats . It is also used by the encoder and decoder to perform a well-formedness check for their respective inputs -LRB- i.e. , HL7 message objects expressed in the MOM and encoded HL7 message strings -RRB- . Although we implemented a prototype version of the encoder and decoder using JAVA , they can be easily packaged and delivered as standalone components using the standard component frameworks

O O O O O O O O O O O O B I I O O O O O B I O B I I O O B I I O O O O O O O O O O O O B I O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O B O O B I I O B O O O B O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O B I O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O B I I I O B O O O O O O O O B O O B I O B I O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O

reusable framework
extensible encoding/decoding framework
abstract message form
activex
javabean
corba
clinical information


Instability phenomena in the gas-metal arc welding self-regulation process Arc instability is a very important determinant of weld quality . The instability behaviour of the gas-metal arc welding -LRB- GMAW -RRB- process is characterized by strong oscillations in arc length and current . In the paper , a model of the GMAW process is developed using an exact arc voltage characteristic . This model is used to study stability of the self-regulation process and to develop a simulation program that helps to understand the transient or dynamic nature of the GMAW process and relationships among current , electrode extension and contact tube-work distance . The process is shown to exhibit instabilities at both long electrode extension and normal extension . Results obtained from simulation runs of the model were also experimentally confirmed by the present author , as reported in this study . In order to explain the concept of the instability phenomena , the metal transfer mode and the arc voltage-current characteristic were examined . Based on this examination , the conclusion of this study is that their combined effects lead to the oscillations in arc current and length

B I O O O O O O O B I O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O B I I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

instability phenomena
arc instability
weld quality
gmaw process
exact arc voltage characteristic
metal transfer mode


Sigma - admissible families over linear orders Admissible sets of the form HYP -LRB- M -RRB- , where M is a recursively saturated system , are treated . We provide descriptions of subsets M , which are Sigma / sub * / - sets in HYP -LRB- M -RRB- , and of families of subsets M , which form Sigma - regular families in HYP -LRB- M -RRB- , in terms of the concept of being fundamental couched in the article . Fundamental subsets and families are characterized for models of dense linear orderings

O O O O O B I O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O B I I

linear orders
recursively saturated system
fundamental subsets
dense linear orderings


Incorporating multi-leaf collimator leaf sequencing into iterative IMRT optimization Intensity modulated radiation therapy -LRB- IMRT -RRB- treatment planning typically considers beam optimization and beam delivery as separate tasks . Following optimization , a multi-leaf collimator -LRB- MLC -RRB- or other beam delivery device is used to generate fluence patterns for patient treatment delivery . Due to limitations and characteristics of the MLC , the deliverable intensity distributions often differ from those produced by the optimizer , leading to differences between the delivered and the optimized doses . Objective function parameters are then adjusted empirically , and the plan is reoptimized to achieve a desired deliverable dose distribution . The resulting plan , though usually acceptable , may not be the best achievable . A method has been developed to incorporate the MLC restrictions into the optimization process . Our in-house IMRT system has been modified to include the calculation of the deliverable intensity into the optimizer . In this process , prior to dose calculation , the MLC leaf sequencer is used to convert intensities to dynamic MLC sequences , from which the deliverable intensities are then determined . All other optimization steps remain the same . To evaluate the effectiveness of deliverable-based optimization , 17 patient cases have been studied . Compared with standard optimization plus conversion to deliverable beams , deliverable-based optimization results show improved isodose coverage and a reduced dose to critical structures . Deliverable-based optimization results are close to the original nondeliverable optimization results , suggesting that IMRT can overcome the MLC limitations by adjusting individual beamlets . The use of deliverable-based optimization may reduce the need for empirical adjustment of objective function parameters and reoptimization of a plan to achieve desired results

O B I I I O O O O B I I I O O O B I O O B I O B I O O O O O O O O O O O O O O O B I O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O B I I O O O O O O O O O

intensity modulated radiation therapy
treatment planning
multileaf collimator leaf sequencing
beam delivery
beam optimization
fluence patterns
objective function parameters
deliverable dose distribution
empirical adjustment

iterative optimization
tumor dose
optimized intensity
gradient-based search algorithm
beamlet ray intensities
newton method
dose-volume objective values


Sensorless control of induction motor drives Controlled induction motor drives without mechanical speed sensors at the motor shaft have the attractions of low cost and high reliability . To replace the sensor the information on the rotor speed is extracted from measured stator voltages and currents at the motor terminals . Vector-controlled drives require estimating the magnitude and spatial orientation of the fundamental magnetic flux waves in the stator or in the rotor . Open-loop estimators or closed-loop observers are used for this purpose . They differ with respect to accuracy , robustness , and sensitivity against model parameter variations . Dynamic performance and steady-state speed accuracy in the low-speed range can be achieved by exploiting parasitic effects of the machine . The overview in this paper uses signal flow graphs of complex space vector quantities to provide an insightful description of the systems used in sensorless control of induction motors

B I O B I I O B I I O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O B I O O O O O O O O O O O O B O B I O O B I I I O O O O O O O O O O O O O O O O O O O O O O O O O O B O O B O B I I O O O O O O O O O O O O O O O O B I O O O O O O O O O O B I I O O B I I O O O O O O O O O O B I O O O

sensorless control
induction motor drives
reliability
stator voltages
magnitude
spatial orientation
fundamental magnetic flux waves
robustness
sensitivity
model parameter variations
parasitic effects
signal flow graphs
space vector quantities

stator currents
vector-controlled drives
open-loop estimators
closed-loop observers
steady-state speed accuracy


Construction of two-sided bounds for initial-boundary value problems This paper extends the bounding operator approach developed for boundary value problems to the case of initial-boundary value problems -LRB- IBVPs -RRB- . Following the general principle of bounding operators enclosing methods for the case of partial differential equations are discussed . In particular , continuous discretization methods with an appropriate error bound controlled shift and monotone extensions of Rothe 's method for parabolic problems are investigated

O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O B I O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O B I O O

bounding operator approach
bounding operators
partial differential equations
parabolic problems

two-sided bounds
initial-boundary value problems


Upper bound analysis of oblique cutting with nose radius tools A generalized upper bound model for calculating the chip flow angle in oblique cutting using flat-faced nose radius tools is described . The projection of the uncut chip area on the rake face is divided into a number of elements parallel to an assumed chip flow direction . The length of each of these elements is used to find the length of the corresponding element on the shear surface using the ratio of the shear velocity to the chip velocity . The area of each element is found as the cross product of the length and its width along the cutting edge . Summing up the area of the elements along the shear surface , the total shear surface area is obtained . The friction area is calculated using the similarity between orthogonal and oblique cutting in the ` equivalent ' plane that includes both the cutting velocity and chip velocity . The cutting power is obtained by summing the shear power and the friction power . The actual chip flow angle and chip velocity are obtained by minimizing the cutting power with respect to both these variables . The shape of the curved shear surface , the chip cross section and the cutting force obtained from this model are presented

B I I O B I O B I I O O O O O O O O B I I O B I O O B I I O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O B I O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O B I O O O O O B I O O O O O O O O B I O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O B I I O B I O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O

upper bound analysis
oblique cutting
nose radius tools
chip flow angle
uncut chip area
shear surface
shear velocity
chip velocity
friction area


Friedberg numberings of families of n-computably enumerable sets We establish a number of results on numberings , in particular , on Friedberg numberings , of families of d.c.e. sets . First , it is proved that there exists a Friedberg numbering of the family of all d.c.e. sets . We also show that this result , patterned on Friedberg 's famous theorem for the family of all c.e. sets , holds for the family of all n-c.e. sets for any n > 2 . Second , it is stated that there exists an infinite family of d.c.e. sets without a Friedberg numbering . Third , it is shown that there exists an infinite family of c.e. sets -LRB- treated as a family of d.c.e. sets -RRB- with a numbering which is unique up to equivalence . Fourth , it is proved that there exists a family of d.c.e. sets with a least numbering -LRB- under reducibility -RRB- which is Friedberg but is not the only numbering -LRB- modulo reducibility -RRB-

B I O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Optimization of cutting conditions for single pass turning operations using a deterministic approach An optimization analysis , strategy and CAM software for the selection of economic cutting conditions in single pass turning operations are presented using a deterministic approach . The optimization is based on criteria typified by the maximum production rate and includes a host of practical constraints . It is shown that the deterministic optimization approach involving mathematical analyses of constrained economic trends and graphical representation on the feed-speed domain provides a clearly defined strategy that not only provides a unique global optimum solution , but also the software that is suitable for on-line CAM applications . A numerical study has verified the developed optimization strategies and software and has shown the economic benefits of using optimization

O O O O O B I I I O O B I O O O O O O B I O O O O B I I O B I I I O O O O B I O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O B I O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

single pass turning operations
deterministic approach
cam software
economic cutting conditions
maximum production rate
mathematical analyses
constrained economic trends

cutting conditions optimization
process planning


Monoids all polygons over which are omega - stable : proof of the Mustafin-Poizat conjecture A monoid S is called an omega - stabilizer -LRB- superstabilizer , or stabilizer -RRB- if every S-polygon has an omega - stable -LRB- superstable , or stable -RRB- theory . It is proved that every omega - stabilizer is a regular monoid . This confirms the Mustafin-Poizat conjecture and allows us to end up the description of omega - stabilizers

B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O

omega -stabilizer
s-polygon
mustafin-poizat conjecture


Prediction of tool and chip temperature in continuous and interrupted machining A numerical model based on the finite difference method is presented to predict tool and chip temperature fields in continuous machining and time varying milling processes . Continuous or steady state machining operations like orthogonal cutting are studied by modeling the heat transfer between the tool and chip at the tool-rake face contact zone . The shear energy created in the primary zone , the friction energy produced at the rake face-chip contact zone and the heat balance between the moving chip and stationary tool are considered . The temperature distribution is solved using the finite difference method . Later , the model is extended to milling where the cutting is interrupted and the chip thickness varies with time . The proposed model combines the steady-state temperature prediction in continuous machining with transient temperature evaluation in interrupted cutting operations where the chip and the process change in a discontinuous manner . The mathematical models and simulation results are in satisfactory agreement with experimental temperature measurements reported in the literature

O O O O O O O O O B I O B I O O O B I I O O O O O O O O O O B I O B I I I O O O O O O O O B I O O O O O B I O O O O O O O O O O O O O B I O O O B I O O B I O O O O O O O O O O O O O O O O O O O O O O B I O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

continuous machining
interrupted machining
numerical model
finite difference method
time varying milling processes
orthogonal cutting
heat transfer
shear energy
primary zone
friction energy
temperature distribution

tool temperature prediction
chip temperature prediction
tool-rake face contact zone
first-order dynamic system
thermal properties


Evaluating the complexity of index sets for families of general recursive functions in the arithmetic hierarchy The complexity of index sets of families of general recursive functions is evaluated in the Kleene-Mostowski arithmetic hierarchy

O O O O O O O O O B I I O O B I O O O O O O O O B I I O O O O O B I

general recursive functions
arithmetic hierarchy

index sets complexity
kleene-mostowski arithmetic hierarchy


A summary of methods applied to tool condition monitoring in drilling Presents a summary of the monitoring methods , signal analysis and diagnostic techniques for tool wear and failure monitoring in drilling that have been tested and reported in the literature . The paper covers only indirect monitoring methods such as force , vibration and current measurements . Signal analysis techniques cover all the methods that have been used with indirect measurements including e.g. statistical parameters and Fast Fourier and Wavelet Transform . Only a limited number of automatic diagnostic tools have been developed for diagnosis of the condition of the tool in drilling . All of these rather diverse approaches that have been available are covered in this study . Only in a few of the papers have attempts been made to compare the chosen approach with other methods . Many of the papers only present one approach and unfortunately quite often the test material of the study is limited especially in what comes to the cutting process parameter variation and also workpiece material

O O O O O O B I I O B O O O O O B I O B I O B I O B I O B I O B O O O O O O O O O O O O O O O B I O O O O O O B I O B I O O O O O O O O O O O O O O B I O O O O B I O O O O O O B I I O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

tool condition monitoring
drilling
monitoring methods
signal analysis
diagnostic techniques
tool wear
failure monitoring
current measurements
statistical parameters
wavelet transform
automatic diagnostic tools

indirect monitoring methods
force measurements
vibration measurements
fast fourier transform


An efficient algorithm for sequential generation of failure states in a network with multi-mode components In this work , a new algorithm for the sequential generation of failure states in a network with multi-mode components is proposed . The algorithm presented in the paper transforms the state enumeration problem into a K-shortest paths problem . Taking advantage of the inherent efficiency of an algorithm for shortest paths enumeration and also of the characteristics of the reliability problem in which it will be used , an algorithm with lower complexity than the best algorithm in the literature for solving this problem , was obtained . Computational results will be presented for comparing the efficiency of both algorithms in terms of CPU time and for problems of different size

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O

sequential failure states generation algorithm


JPEG2000 : standard for interactive imaging JPEG2000 is the latest image compression standard to emerge from the Joint Photographic Experts Group -LRB- JPEG -RRB- working under the auspices of the International Standards Organization . Although the new standard does offer superior compression performance to JPEG , JPEG2000 provides a whole new way of interacting with compressed imagery in a scalable and interoperable fashion . This paper provides a tutorial-style review of the new standard , explaining the technology on which it is based and drawing comparisons with JPEG and other compression standards . The paper also describes new work , exploiting the capabilities of JPEG2000 in client-server systems for efficient interactive browsing of images over the Internet

B O O O B I B O O O B I O O O O O B I I I O O O O O O O O O B I I O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O

jpeg2000
interactive imaging
image compression
joint photographic experts group
international standards organization
review

scalable compression
interoperable compression
client-server systems


A method for geometrical verification of dynamic intensity modulated radiotherapy using a scanning electronic portal imaging device In order to guarantee the safe delivery of dynamic intensity modulated radiotherapy -LRB- IMRT -RRB- , verification of the leaf trajectories during the treatment is necessary . Our aim in this study is to develop a method for on-line verification of leaf trajectories using an electronic portal imaging device with scanning read-out , independent of the multileaf collimator . Examples of such scanning imagers are electronic portal imaging devices -LRB- EPIDs -RRB- based on liquid-filled ionization chambers and those based on amorphous silicon . Portal images were acquired continuously with a liquid-filled ionization chamber EPID during the delivery , together with the signal of treatment progress that is generated by the accelerator . For each portal image , the prescribed leaf and diaphragm positions were computed from the dynamic prescription and the progress information . Motion distortion effects of the leaves are corrected based on the treatment progress that is recorded for each image row . The aperture formed by the prescribed leaves and diaphragms is used as the reference field edge , while the actual field edge is found using a maximum-gradient edge detector . The errors in leaf and diaphragm position are found from the deviations between the reference field edge and the detected field edge . Earlier measurements of the dynamic EPID response show that the accuracy of the detected field edge is better than 1 mm . To ensure that the verification is independent of inaccuracies in the acquired progress signal , the signal was checked with diode measurements beforehand . The method was tested on three different dynamic prescriptions . Using the described method , we correctly reproduced the distorted field edges . Verifying a single portal image took 0.1 s on an 866 MHz personal computer . Two flaws in the control system of our experimental dynamic multileaf collimator were correctly revealed with our method . First , the errors in leaf position increase with leaf speed , indicating a delay of approximately 0.8 s in the control system . Second , the accuracy of the leaves and diaphragms depends on the direction of motion . In conclusion , the described verification method is suitable for detailed verification of leaf trajectories during dynamic IMRT

O O O O O O B I I I O O O O O O O O O O O O B I O B I I I O O O O O O O B I O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O B I O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O

geometrical verification method
on-line verification
scanning read-out
liquid-filled ionization chambers
leaf positions
dose distributions
treatment planning


Trading exchanges : online marketplaces evolve Looks at how trading exchanges are evolving rapidly to help manufacturers keep up with customer demand

B I O B I O O O O B I O O O O O B O O O B I

online marketplaces
trading exchanges
manufacturers
customer demand

enterprise platforms
supply chain management
enterprise resource planning
core software platform
private exchanges
integration technology
middleware
xml standards
content management capabilities


Buying into the relationship -LSB- business software -RSB- Choosing the right software to improve business processes can have a huge impact on a company 's efficiency and profitability . While it is sometimes hard to get beyond vendor hype about software features and functionality and know what to realistically expect , it is even more difficult to determine if the vendor is the right vendor to partner with . Thus picking the right software is important , but companies have to realize that what they are really buying into is a relationship with the vendor

O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

vendor relationship
management
software evaluation


Recognizing groups G/sub 2 / -LRB- 3/sup n / -RRB- by their element orders It is proved that a finite group that is isomorphic to a simple non-Abelian group G = G/sub 2 / -LRB- 3/sup n / -RRB- is , up to isomorphism , recognized by a set omega -LRB- G -RRB- of its element orders , that is , H approximately = G if omega -LRB- H -RRB- = omega -LRB- G -RRB- for some finite group H

O O O O O O O O O O O O B I O O O O O B I O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O B I O


Numerical behaviour of stable and unstable solitary waves In this paper we analyse the behaviour in time of the numerical approximations to solitary wave solutions of the generalized Benjamin-Bona-Mahony equation . This equation possesses an important property : the stability of these solutions depends on their velocity . We identify the error propagation mechanisms in both the stable and unstable case . In particular , we show that in the stable case , numerical methods that preserve some conserved quantities of the problem are more appropriate for the simulation of this kind of solutions

B I O O O B I I O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O

numerical behaviour
unstable solitary waves
numerical approximations
error propagation mechanisms
numerical methods


Multiple shooting using a dichotomically stable integrator for solving differential-algebraic equations In previous work by the first author , it has been established that a dichotomically stable discretization is needed when solving a stiff boundary-value problem in ordinary differential equations -LRB- ODEs -RRB- , when sharp boundary layers may occur at each end of the interval . A dichotomically stable implicit Runge-Kutta method , using the 3-stage , fourth-order , Lobatto IIIA formulae , has been implemented in a variable step-size initial-value integrator , which could be used in a multiple-shooting approach . In the case of index-one differential-algebraic equations -LRB- DAEs -RRB- the use of the Lobatto IIIA formulae has an advantage , over a comparable Gaussian method , that the order is the same for both differential and algebraic variables , and there is no need to treat them separately . The ODE integrator has been adapted for the solution of index-one DAEs , and the resulting integrator -LRB- SYMDAE -RRB- has been inserted into the multiple-shooting code -LRB- MSHDAE -RRB- previously developed by R. Lamour for differential-algebraic boundary-value problems . The standard version of MSHDAE uses a BDF integrator , which is not dichotomically stable , and for some stiff test problems this fails to integrate across the interval of interest , while the dichotomically stable integrator SYMDAE encounters no difficulty . Indeed , for such problems , the modified version of MSHDAE produces an accurate solution , and within limits imposed by computer word length , the efficiency of the solution process improves with increasing stiffness . For some nonstiff problems , the solution is also entirely satisfactory

B I O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

multiple shooting
ordinary differential equations
lobatto iiia formulae
dichotomically stable integrator

stiff boundary-value problem
implicit runge-kutta method
initial-value integrator
differential-algebraic equations


New methods for oscillatory problems based on classical codes The numerical integration of differential equations with oscillatory solutions is a very common problem in many fields of the applied sciences . Some methods have been specially devised for this kind of problem . In most of them , the calculation of the coefficients needs more computational effort than the classical codes because such coefficients depend on the step-size in a not simple manner . On the contrary , in this work we present new algorithms specially designed for perturbed oscillators whose coefficients have a simple dependence on the step-size . The methods obtained are competitive when comparing with classical and special codes

O O O B I O O B I O B I O B I O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O

oscillatory problems
classical codes
numerical integration
differential equations
oscillatory solutions
perturbed oscillators


It 's time to buy There is an upside to a down economy : over-zealous suppliers are willing to make deals that were unthinkable a few years ago . That 's because vendors are experiencing the same money squeeze as manufacturers , which makes the year 2002 the perfect time to invest in new technology . The author states that when negotiating the deal , provisions for unexpected costs , an exit strategy , and even shared risk with the vendor should be on the table

O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O B I O O O B I O O B O O O O O

unexpected costs
exit strategy
shared risk
vendor
suppliers
money squeeze

negotiation
buyers market
bargaining power


CRM : approaching zenith Looks at how manufacturers are starting to warm up to the concept of customer relationship management . CRM has matured into what is expected to be big business . As CRM software evolves to its second , some say third , generation , it 's likely to be more valuable to holdouts in manufacturing and other sectors

B O O O O O O B O O O O O O O O O B I I O B O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O B O O O

manufacturers
customer relationship management
crm
manufacturing


A new approach to the d-MC problem Many real-world systems are multi-state systems composed of multi-state components in which the reliability can be computed in terms of the lower bound points of level d , called d-Mincuts -LRB- d-MCs -RRB- . Such systems -LRB- electric power , transportation , etc. -RRB- may be regarded as flow networks whose arcs have independent , discrete , limited and multi-valued random capacities . In this paper , all MCs are assumed to be known in advance , and the authors focused on how to verify each d-MC candidate before using d-MCs to calculate the network reliability . The proposed algorithm is more efficient than existing algorithms . The algorithm runs in O -LRB- p sigma mn -RRB- time , a significant improvement over the previous O -LRB- p sigma m/sup 2 / -RRB- time bounds based on max-flow/min-cut , where p and or are the number of MCs and d-MC candidates , respectively . It is simple , intuitive and uses no complex data structures . An example is given to show how all d-MC candidates are found and verified by the proposed algorithm . Then the reliability of this example is computed

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

d-mc problem
multi-state systems
multi-state components
reliability computation
d-mincuts
failure analysis algorithm
max-flow/min-cut


Marble cutting with single point cutting tool and diamond segments An investigation has been undertaken into the frame sawing with diamond blades . The kinematic behaviour of the frame sawing process is discussed . Under different cutting conditions , cutting and indenting-cutting tests are carried out by single point cutting tools and single diamond segments . The results indicate that the depth of cut per diamond grit increases as the blades move forward . Only a few grits per segment can remove the material in the cutting process . When the direction of the stroke changes , the cutting forces do not decrease to zero because of the residual plastic deformation beneath the diamond grits . The plastic deformation and fracture chipping of material are the dominant removal processes , which can be explained by the fracture theory of brittle material indentation

B I O B I I I O B I O O O O O O O B I O O O O O B I O O B I O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O B I O O O O O B I O O O O O O O B I O B I I

marble cutting
single point cutting tool
diamond segments
frame sawing
kinematic behaviour
residual plastic deformation
fracture chipping
removal processes
fracture theory
brittle material indentation


Portal dose image prediction for dosimetric treatment verification in radiotherapy . II . An algorithm for wedged beams A method is presented for calculation of a two-dimensional function , T/sub wedge / -LRB- x , y -RRB- , describing the transmission of a wedged photon beam through a patient . This in an extension of the method that we have published for open -LRB- nonwedged -RRB- fields -LSB- Med . Phys . 25 , 830-840 -LRB- 1998 -RRB- -RSB- . Transmission functions for open fields are being used in our clinic for prediction of portal dose images -LRB- PDI , i.e. , a dose distribution behind the patient in a plane normal to the beam axis -RRB- , which are compared with PDIs measured with an electronic portal imaging device -LRB- EPID -RRB- . The calculations are based on the planning CT scan of the patient and on the irradiation geometry as determined in the treatment planning process . Input data for the developed algorithm for wedged beams are derived from -LRB- the already available -RRB- measured input data set for transmission prediction in open beams , which is extended with only a limited set of measurements in the wedged beam . The method has been tested for a PDI plane at 160 cm from the focus , in agreement with the applied focus-to-detector distance of our fluoroscopic EPIDs . For low and high energy photon beams -LRB- 6 and 23 MV -RRB- good agreement -LRB- ~ 1 % -RRB- has been found between calculated and measured transmissions for a slab and a thorax phantom

B I I I O B I I O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I O O O B I O O O O O O O O O O O O O O O O O O O O O B I

portal dose image prediction
dosimetric treatment verification
radiotherapy
wedged photon beam
planning ct scan
irradiation geometry
high energy photon beams
thorax phantom
open beams
23 mv

transmission dosimetry
wedged beams algorithm
two-dimensional function
low energy photon beams
slab phantom
in vivo dosimetry
electronic portal imaging devices
fluoroscopic ccd camera
pencil beam algorithm
cadplan planning system
virtual wedges
6 mv


Evolving robust asynchronous cellular automata for the density task In this paper the evolution of three kinds of asynchronous cellular automata are studied for the density task . Results are compared with those obtained for synchronous automata and the influence of various asynchronous update policies on the computational strategy is described . How synchronous and asynchronous cellular automata behave is investigated when the update policy is gradually changed , showing that asynchronous cellular automata are more adaptable . The behavior of synchronous and asynchronous evolved automata are studied under the presence of random noise of two kinds and it is shown that asynchronous cellular automata implicitly offer superior fault tolerance

O O B I I O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O B I O O O O O O O O B I I O O O B I

asynchronous cellular automata
fault tolerance
random noise
synchronous automata

cellular automata
discrete dynamical systems


Moving into the mainstream -LSB- product lifecycle management -RSB- Product lifecycle management -LRB- PLM -RRB- is widely recognised by most manufacturing companies , as manufacturers begin to identify and implement targeted projects intended to deliver return-on investment in a timely fashion . Vendors are also releasing second-generation PLM products that are packaged , out-of-the-box solutions

O O O O O B I I O B I I O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

product lifecycle management
manufacturing companies

product data management
product development
enterprise resource planning


Effect of multileaf collimator leaf width on physical dose distributions in the treatment of CNS and head and neck neoplasms with intensity modulated radiation therapy The purpose of this work is to examine physical radiation dose differences between two multileaf collimator -LRB- MLC -RRB- leaf widths -LRB- 5 and 10 mm -RRB- in the treatment of CNS and head and neck neoplasms with intensity modulated radiation therapy -LRB- IMRT -RRB- . Three clinical patients with CNS tumors were planned with two different MLC leaf sizes , 5 and 10 mm , representing Varian-120 and Varian-80 Millennium multileaf collimators , respectively . Two sets of IMRT treatment plans were developed . The goal of the first set was radiation dose conformality in three dimensions . The goal for the second set was organ avoidance of a nearby critical structure while maintaining adequate coverage of the target volume . Treatment planning utilized the CadPlan/Helios system -LRB- Varian Medical Systems , Milpitas CA -RRB- for dynamic MLC treatment delivery . All beam parameters and optimization -LRB- cost function -RRB- parameters were identical for the 5 and 10 mm plans . For all cases the number of beams , gantry positions , and table positions were taken from clinically treated three-dimensional conformal radiotherapy plans . Conformality was measured by the ratio of the planning isodose volume to the target volume . Organ avoidance was measured by the volume of the critical structure receiving greater than 90 % of the prescription dose -LRB- V/sub 90 / -RRB- . For three patients with squamous cell carcinoma of the head and neck -LRB- T2-T4 N0-N2c M0 -RRB- 5 and 10 mm leaf widths were compared for parotid preservation utilizing nine coplanar equally spaced beams delivering a simultaneous integrated boost . Because modest differences in physical dose to the parotid were detected , a NTCP model based upon the clinical parameters of Eisbruch et al. was then used for comparisons . The conformality improved in all three CNS cases for the 5 mm plans compared to the 10 mm plans . For the organ avoidance plans , V/sub 90 / also improved in two of the three cases when the 5 mm leaf width was utilized for IMRT treatment delivery . In the third case , both the 5 and 10 mm plans were able to spare the critical structure with none of the structure receiving more than 90 % of the prescription dose , but in the moderate dose range , less dose was delivered to the critical structure with the 5 mm plan . For the head and neck cases both the 5 and 10 * 2.5 mm beamlets dMLC sliding window techniques spared the contralateral parotid gland while maintaining target volume coverage . The mean parotid dose was modestly lower with the smaller beamlet size -LRB- 21.04 Gy vs 22.36 Gy -RRB- . The resulting average NTCP values were 13.72 % for 10 mm dMLC and 8.24 % for 5 mm dMLC . In conclusion , five mm leaf width results in an improvement in physical dose distribution over 10 mm leaf width that may be clinically relevant in some cases . These differences may be most pronounced for single fraction radiosurgery or in cases where the tolerance of the sensitive organ is less than or close to the target volume prescription

O O B I I I O B I I O O O O O O B I I I O B I I I O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O B I I I O B I I I O O O O O O O O B I O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O B I O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O B I O O O O O B I O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O

multileaf collimator leaf width
physical dose distributions
head and neck neoplasms
intensity modulated radiation therapy
cns tumors
treatment planning
parotid preservation
conformal radiotherapy
single fraction radiosurgery
beamlet size
5 mm
10 mm

cns neoplasms
optimization parameters
acceptable tumor coverage
minimal toxicity
collimator rotation
21.04 gy
22.36 gy


A comprehensive chatter prediction model for face turning operation including tool wear effect Presents a three-dimensional mechanistic frequency domain chatter model for face turning processes , that can account for the effects of tool wear including process damping . New formulations are presented to model the variation in process damping forces along nonlinear tool geometries such as the nose radius . The underlying dynamic force model simulates the variation in the chip cross-sectional area by accounting for the displacements in the axial and radial directions . The model can be used to determine stability boundaries under various cutting conditions and different states of flank wear . Experimental results for different amounts of wear are provided as a validation for the model

O O B I I O B I I O B I I O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O B I O O O O O O O O B I O O O O O O O O O O O O O O O O

chatter prediction model
face turning operation
tool wear effect
process damping
radial directions
stability boundaries
flank wear


Computing failure probabilities . Applications to reliability analysis The paper presents one method for calculating failure probabilities with applications to reliability analysis . The method is based on transforming the initial set of variables to a n-dimensional uniform random variable in the unit hypercube , together with the limit condition set and calculating the associated probability using a recursive method based on the Gauss-Legendre quadrature formulas to calculate the resulting multiple integrals . An example of application is used to illustrate the proposed method

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O B I O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O

unit hypercube
limit condition
recursive method

failure probabilities computation
reliability analysis applications
n-dimensional uniform random variable
gauss-legendre quadrature formulae
multiple integrals calculation
tail approximation


Self-organized critical traffic in parallel computer networks In a recent paper , we analysed the dynamics of traffic flow in a simple , square lattice architecture . It was shown that a phase transition takes place between a free and a congested phase . The transition point was shown to exhibit optimal information transfer and wide fluctuations in time , with scale-free properties . In this paper , we further extend our analysis by considering a generalization of the previous model in which the rate of packet emission is regulated by the local congestion perceived by each node . As a result of the feedback between traffic congestion and packet release , the system is poised at criticality . Many well-known statistical features displayed by Internet traffic are recovered from our model in a natural way

O O O O B I I O O O O O O O O O O O O O O O O B I I O O O O O O B I O O O O O O O B I O O B I O O O O B I I O B I O O O O O O O O O O O O O O O O O O O B O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O B I O O B I O O O O O O O O O

phase transition
congested phase
transition point
optimal information transfer
wide fluctuations
generalization
packet emission
packet release
statistical features
internet traffic
square lattice architecture
parallel computer networks

self-organized critical traffic
traffic flow dynamics
free phase
scale-free properties


Manufacturing data analysis of machine tool errors within a contemporary small manufacturing enterprise The main focus of the paper is directed at the determination of manufacturing errors within the contemporary smaller manufacturing enterprise sector . The manufacturing error diagnosis is achieved through the manufacturing data analysis of the results obtained from the inspection of the component on a co-ordinate measuring machine . This manufacturing data analysis activity adopts a feature-based approach and is conducted through the application of a forward chaining expert system , called the product data analysis distributed diagnostic expert system , which forms part of a larger prototype feedback system entitled the production data analysis framework . The paper introduces the manufacturing error categorisations that are associated with milling type operations , knowledge acquisition and representation , conceptual structure and operating procedure of the prototype manufacturing data analysis facility . The paper concludes with a brief evaluation of the logic employed through the simulation of manufacturing error scenarios . This prototype manufacturing data analysis expert system provides a valuable aid for the rapid diagnosis and elimination of manufacturing errors on a 3-axis vertical machining centre in an environment where operator expertise is limited

B I I O B I I O O B I I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O B O O O O O O O O O O B I I O O O O O O O O O O O O O B I I I O O O B I I I I I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O B I O O O B I O B I O O O B I I O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

fixturing errors
programming errors
2 1/2d components
3-axis vertical machining centre
knowledge representation
co-ordinate measuring machine
feature-based approach


Implementing : it 's all about processes Looks at how the key to successful technology deployment can be found in a set of four basic disciplines

O O O O O O O O O O O O O O B I O O O O O O O O O O

vendor-supplied hardware integration services

vendor-supplied software integration services


Post-projected Runge-Kutta methods for index-2 differential-algebraic equations A new projection technique for Runge-Kutta methods applied to index-2 differential-algebraic equations is presented in which the numerical approximation is projected only as part of the output process . It is shown that for methods that are strictly stable at infinity , the order of convergence is unaffected compared to standard projected methods . Gauss methods , for which this technique is of special interest when some symmetry is to be preserved , are studied in more detail

O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O

numerical approximation
order of convergence
projected methods


The effect of voxel size on the accuracy of dose-volume histograms of prostate / sup 125/I seed implants Cumulative dose-volume histograms -LRB- DVH -RRB- are crucial in evaluating the quality of radioactive seed prostate implants . When calculating DVHs , the choice of voxel size is a compromise between computational speed -LRB- larger voxels -RRB- and accuracy -LRB- smaller voxels -RRB- . We quantified the effect of voxel size on the accuracy of DVHs using an in-house computer program . The program was validated by comparison with a hand-calculated DVH for a single 0.4-U iodine-125 model 6711 seed . We used the program to find the voxel size required to obtain accurate DVHs of five iodine-125 prostate implant patients at our institution . One-millimeter cubes were sufficient to obtain DVHs that are accurate within 5 % up to 200 % of the prescription dose . For the five patient plans , we obtained good agreement with the VariSeed -LRB- version 6.7 , Varian , USA -RRB- treatment planning software 's DVH algorithm by using voxels with a sup-inf dimension equal to the spacing between successive transverse seed implant planes -LRB- 5 mm -RRB- . The volume that receives at least 200 % of the target dose , V/sub 200 / , calculated by VariSeed was 30 % to 43 % larger than that calculated by our program with small voxels . The single-seed DVH calculated by VariSeed fell below the hand calculation by up to 50 % at low doses -LRB- 30 Gy -RRB- , and above it by over 50 % at high doses -LRB- > 250 Gy -RRB-

O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I O O O O O O O O B I O O O O B I O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

radioactive seed prostate implants
voxel size
computational speed

variseed treatment planning software's dose-volume histogram algorithm


Embedding the outer automorphism group Out -LRB- F/sub n / -RRB- of a free group of rank n in the group Out -LRB- F/sub m / -RRB- for m > n It is proved that for every n > or = 1 , the group Out -LRB- F/sub n / -RRB- is embedded in the group Out -LRB- F/sub m / -RRB- with m = 1 + -LRB- n - 1 -RRB- k/sup n / , where k is an arbitrary natural number coprime to n - 1

O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I O O O O

free group
arbitrary natural number coprime


Recognition of finite simple groups S/sub 4 / -LRB- q -RRB- by their element orders It is proved that among simple groups S/sub 4 / -LRB- q -RRB- in the class of finite-groups , only the groups S/sub 4 / -LRB- 3/sup n / -RRB- , where n is an odd number greater than unity , are recognizable by a set of their element orders . It is also shown that simple groups U/sub 3 / -LRB- 9 -RRB- , / sup 3/D/sub 4 / -LRB- 2 -RRB- , G/sub 2 / -LRB- 4 -RRB- , S/sub 6 / -LRB- 3 -RRB- , F/sub 4 / -LRB- 2 -RRB- , and / sup 2/E/sub 6 / -LRB- 2 -RRB- are recognizable , but L/sub 3 / -LRB- 3 -RRB- is not

O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

finite simple groups recognition
divisibility relation


From powder to perfect parts GKN Sinter Metals has increased productivity and quality by automating the powder metal lines that produce its transmission parts

O O O O O B I I O O O O O O B O B I I O O O O O

gkn sinter metals
powder metal lines
automating

conveyors
gentle transfer units
robotic systems


More than the money -LSB- software project -RSB- Experiences creating budgets for large software projects have taught manufacturers that it is not about the money - it is about what one really needs . Before a company can begin to build a budget for a software . project , it has to have a good understanding of what business issues need to be addressed and what the business objectives are . This step is critical because it defines the business goals , outlines the metrics for success , sets the scope for the project , and defines the criteria for selecting the right software

O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

manufacturing industry
budgeting
management
software requirements


Multiresolution Markov models for signal and image processing Reviews a significant component of the rich field of statistical multiresolution -LRB- MR -RRB- modeling and processing . These MR methods have found application and permeated the literature of a widely scattered set of disciplines , and one of our principal objectives is to present a single , coherent picture of this framework . A second goal is to describe how this topic fits into the even larger field of MR methods and concepts-in particular , making ties to topics such as wavelets and multigrid methods . A third goal is to provide several alternate viewpoints for this body of work , as the methods and concepts we describe intersect with a number of other fields . The principle focus of our presentation is the class of MR Markov processes defined on pyramidally organized trees . The attractiveness of these models stems from both the very efficient algorithms they admit and their expressive power and broad applicability . We show how a variety of methods and models relate to this framework including models for self-similar and 1/f processes . We also illustrate how these methods have been used in practice

B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

multiresolution markov models
wavelets
multigrid methods
pyramidally organized trees

statistical multiresolution modeling
self-similar processes
1/f processes


Direct aperture optimization : A turnkey solution for step-and-shoot IMRT IMRT treatment plans for step-and-shoot delivery have traditionally been produced through the optimization of intensity distributions -LRB- or maps -RRB- for each beam angle . The optimization step is followed by the application of a leaf-sequencing algorithm that translates each intensity map into a set of deliverable aperture shapes . In this article , we introduce an automated planning system in which we bypass the traditional intensity optimization , and instead directly optimize the shapes and the weights of the apertures . We call this approach `` direct aperture optimization . '' This technique allows the user to specify the maximum number of apertures per beam direction , and hence provides significant control over the complexity of the treatment delivery . This is possible because the machine dependent delivery constraints imposed by the MLC are enforced within the aperture optimization algorithm rather than in a separate leaf-sequencing step . The leaf settings and the aperture intensities are optimized simultaneously using a simulated annealing algorithm . We have tested direct aperture optimization on a variety of patient cases using the EGS4/BEAM Monte Carlo package for our dose calculation engine . The results demonstrate that direct aperture optimization can produce highly conformal step-and-shoot treatment plans using only three to five apertures per beam direction . As compared with traditional optimization strategies , our studies demonstrate that direct aperture optimization can result in a significant reduction in both the number of beam segments and the number of monitor units . Direct aperture optimization therefore produces highly efficient treatment deliveries that maintain the full dosimetric benefits of IMRT

B I I O O B I O O O B I I O O O O O O O O O O O B I O O B O O O B I O O B I O O O O O O O O O O O O B I O O O O B I I O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I O O O B O O O O B I I O O O O O O O O O B I O O B I O O O O O B I I O O O O B I I O O O O B I O O O O O O O O B I I O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O B I O O O O B I O B I I O O B I I I O O O B I I O O

direct aperture optimization
turnkey solution
imrt treatment plans
intensity distributions
maps
beam angle
optimization step
intensity map
deliverable aperture shapes
automated planning system
machine dependent delivery constraints
mlc
aperture optimization algorithm
leaf settings
aperture intensities
simulated annealing algorithm
patient cases
dose calculation engine
beam segments
monitor units
highly efficient treatment deliveries
full dosimetric benefits


From continuous recovery to discrete filtering in numerical approximations of conservation laws Modern numerical approximations of conservation laws rely on numerical dissipation as a means of stabilization . The older , alternative approach is the use of central differencing with a dose of artificial dissipation . In this paper we review the successful class of weighted essentially non-oscillatory finite volume schemes which comprise sophisticated methods of the first kind . New developments in image processing have made new devices possible which can serve as highly nonlinear artificial dissipation terms . We view artificial dissipation as discrete filter operation and introduce several new algorithms inspired by image processing

O B I O B I O B I O B I O B I O B I O O B I O O O O O O O O O O O O O O O B I O O O O B I O O O O O O O O O O O O O B I I O O O O O O O O O O O O B I O O O O O O O O O O O B I O O O O B I O B I I O O O O O O O B I

continuous recovery
discrete filtering
numerical approximations
conservation laws
numerical dissipation
central differencing
artificial dissipation
finite volume schemes
image processing
discrete filter operation


Sharpening the estimate of the stability constant in the maximum-norm of the Crank-Nicolson scheme for the one-dimensional heat equation This paper is concerned with the stability constant C/sub infinity / in the maximum-norm of the Crank-Nicolson scheme applied . to the one-dimensional heat equation . A well known result due to S.J. Serdyukova is that C/sub infinity / < 23 . In the present paper , by using a sharp resolvent estimate for the discrete Laplacian together with the Cauchy formula , it is shown that 3 < or = C/sub infinity / < 4.325 . This bound also holds when the heat equation is considered on a bounded interval along with Dirichlet or Neumann boundary conditions

O O O O O B I O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O B I O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I

stability constant
sharp resolvent estimate
discrete laplacian
cauchy formula
neumann boundary conditions

crank-nicolson scheme
one-dimensional heat equation
dirichlet boundary conditions


Measuring return : revealing ROI The most critical part of the return-on-investment odyssey is to develop metrics that matter to the business and to measure systems in terms of their ability to help achieve those business goals . Everything must flow from those key metrics . And do n't forget to revisit those every now and then , too . Since all systems wind down over time , it 's important to keep tabs on how well your automation investment is meeting the metrics established by your company . Manufacturers are clamoring for a tool to help quantify returns and analyze the results

O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O