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Modern Applications of Power Electronics to Marine Propulsion Systems C G Hodge BSc MSc CEng FIMarEST Rolls-Royce plc, PO Box 3, Filton, Bristol, BS34 7QE, United Kingdom Phone: +44 (0) 117 979 5508, Fax: +44 (0) 117 979 6424 E-mail: [email protected] Abstract – This paper reviews the current state of marine electric propulsion systems and the various system developments currently being pursued to achieve greater power density and explains why these developments are economically and operationally desirable. The paper also reviews the specific power electronic converter applications that are supporting the system developments with particular reference to converter design. The paper concludes by considering the likely future direction of development for power electronic converters. Indexing Terms – Electric Warship, More Electric Applications, Integrated Full Electric Propulsion. I. INTRODUCTION Marine propulsion systems are undergoing rapid development with a significant thrust towards the use of electrical propulsion and the integration of auxiliary and propulsion power systems. Whether the vessel in question is a large cruise liner driven by external podded motors, a small highly powered warship with inboard motors and shafts or an off-shore oil support vessel the need for very flexible, robust and compact power systems is ever increasing. This need is being satisfied through the recent advances, verging on revolution, in power electronic device construction and their application for power conversion and control. The recent developments in switching device implementation have been fundamental to the developments underway in marine electrical power systems. AS well as the Insulated Gate Bi-Polar Transistor (IGBT) Devices such as the Integrated Gate Commutating Thyristor (IGCT) and MOS Turn Off Thyristor (MTO) are beginning to be considered for use in marine electrical power systems. However, to allow space for discussion of the developments also underway in converter topology and control, this paper will not discuss these devices further. II. INTEGRATED FULL ELECTRIC PROPULSION A traditional mechanical marine propulsion system uses prime movers to drive propellers via shafts and in the most common arrangements each shaft is driven by its own dedicated prime mover. Unless complicated combining gearboxes are used it is not possible to cross-connect the shafts. The variation of propulsion power with speed is – to a first approximation – a cubic relationship. As a result 80% power provides 93% speed but 25% speed demands only around 1.5% power. Since many vessels rarely use full speed this results in the prime movers running for lengthy periods at fractional loads that reduce efficiency and increase operating costs. Electric propulsion – which is perhaps more accurately described as electrical transmission (between the mechanical prime movers and propellers) – offers a relatively straight forward method of cross connecting shafts in order to alleviate the light load running of the prime movers when the vessel operates at reduced speed. Figure 1 illustrates a conventional X Electrical System normally run split DG X DG X GT GB GT Shafts cannot be cross-connected GT GB GT X X DG X DG Figure 1: Mechanical Propulsion System mechanical propulsion system for a vessel with 2 shafts and an equivalent electrical propulsion system. The advantage of the latter is that a single prime mover can provide power to either shaft and – with the adoption of modern power electronics – astern operation and ship manoeuvring is possible without recourse to controllable pitch propellers or complicated reversing gearboxes. A further advantage of electrical propulsion is that the electrical generators need not be limited to supplying propulsion power alone – they can also be arranged to provide the electrical power required for the ship’s domestic and other uses. This auxiliary electrical power system is often termed the ship’s service power system and by combining this with the electrical propulsion system a common set of prime movers can provide power to either the propulsion or ship’s service duties. This arrangement is termed an integrated power system. When the electrical propulsion system is rated at full power (with no direct drive mechanical boost arrangement) the overall system is designated as Integrated Full Electric Propulsion (IFEP), figure 2 illustrates such an IFEP GEN CONV 20 MW GEN 2 MW CONV CONV CONV PMPM mass as desirable characteristics. There are several programmes across the world aimed at developing compact direct drive propulsion motors, notably in the United States of America, France and the United Kingdom however these programmes – though fascinating – are outside the scope of this paper. The need for compact and efficient equipment applies equally to the power electronic converters that are used to drive the propulsion motors in IFEP installations and the developments underway in this area will now be reviewed. IV. GENERAL ASPECTS OF MARINE POWER ELECTRONIC CONVERTERS Devices Used: Historically the converters used in marine electrical propulsion systems have been based on thyristors and these applications have obtained their commutating voltages either from the supply-side voltage source (as in cycloconverters) or from the motor back-emf (as in current source converters). Although this – as a type of natural commutation – brings high conversion efficiency such thyristor-based converters are in general too large for use in space sensitive applications and in addition each have significant (though differing) limitations on their frequency output, control and waveform quality. As a result current source converters and cycloconverters are now becoming displaced by voltage source Pulse Width Modulated (PWM) Converters that use devices capable of switching current off as well as on – such as IGBTs. Pulse Width Modulation: Figure 3 illustrates the construction of a PWM pulse train that would provide an effective sinusoidal voltage to a load. As with all PWM strategies the width of each pulse and succeeding “gap” are controlled to present the correct average voltage to the load. In the simplest strategy – as illustrated in Figure 3 – a saw tooth switching 300 200 BATTERY CONV CONV CONV PMPM GEN 8 MW GEN 800 V DC 6.6 kV AC 20 MW Figure 2: IFEP Propulsion System system. Integration of the two power systems can reduce the total number of prime movers that need to be installed – bringing reduced vessel acquisition costs – and where the ship’s service load is a significant proportion of the propulsion requirement, additional fuel savings can be achieved by using the ship’s service power as a base load for the prime movers – thereby ensuring that the engines are loaded sufficiently to retain fuel efficiency. Given their high hotel load, this latter aspect is the main reason why cruise liners have all but universally adopted IFEP in recent years. Even simple reduction gearboxes are generally avoided with IFEP installations as direct drive motors are feasible and thereby the additional purchase cost, maintenance burden and inefficiencies associated with a gearbox are avoided. III. THE IFEP EQUIPMENT REQUIREMENT Ships are always limited with respect to internal space and reduced equipment volumes have direct benefits in providing capacity for other purposes, not least additional cargo, passengers or in the case of warships weaponry. One benefit of electrical propulsion is that it provides the opportunity to move the electric motors towards the stern of the vessel leaving the higher value central hull volume for use directly associated with the vessel’s purpose. However, for hydrodynamic reasons, the stern of a vessel reduces in cross section and thus, as a result of its reduced displacement, the stern provides less uplift than other sections of the hull form. Consequently, equipment placed towards the stern needs to be relatively light if unacceptable stresses are to be avoided within the hull. Therefore marine electrical propulsion motors have both low volume and 100 Vol ts 0 0 0.002 0.004 0.006 0.008 0.01 0.012 0.014 0.016 0.018 -100 -200 -300 Time (s) Desired Voltage Saw Tooth PWM Figure 3: PWM Waveforms function is used to determine when the switches operate. Series Connection of Switches: The initial problem with PWM converters for marine propulsion use was that the rating of the available power switches were insufficient to provide the necessary power, which can often be 20 MW per shaft or higher. As described later, Alstom was the first company to overcome this problem and developed highly rated converters using series connected devices. One consequence of the use of series connected IGBTs is that the IGBT temperature must be tightly controlled in order to preserve the switching characteristics of each IGBT. Voltage Clamped Switching: As IGBT ratings have increased other topologies that avoid the need for series connection have become feasible; such as Neutral Point Clamped (NPC) Converters. Figure 4 shows a +V DC the losses generated in the capacitor network as it increases in size. As a result a 5 level diode clamped converter probably represents the limit of this topology. V. CONSTRAINTS OF MARINE POWER ELECTRONIC CONVERTERS Harmonic Distortion: Any converter’s prime function is to transform power between differing systems, AC to DC is perhaps the simplest converter (a DC rectifier) but even that shares a characteristic with all other converters – it switches current and voltage. The switching action allows the most favourably suited input phases to be connected to the appropriate output lines such that the desired form of output power is provided. Again in the case of the rectifier this simply means connecting the most positive input phase to the positive DC rail and the most negative of the input phases to the negative DC rail – this can be achieved passively through the use of diodes but nevertheless a switching process remains which results in discontinuous currents being drawn from the supply. As the current drawn from the supply is discontinuous it is – by definition – non-sinusoidal and it therefore creates non-sinusoidal voltage drops in the supply system. These non-sinusoidal voltage drops mean that the supply voltage (as seen by the converter itself and other connected equipment) is no longer sinusoidal – the converter has distorted the supply system. This feature applies to all converters: rectifiers, cycloconverters, current and voltage source converters. The most common form of distortion is that which results from DC rectification since this is a feature of the rectifiers found as the front ends of current and voltage source converters, however cycloconverters also exhibit supply side distortion and of a more complicated form. Since the supply system voltage and load current waveforms (although no longer sinusoidal) remain periodic, Fourier analysis can be used to decompose them into spectra of frequency components – each an integer multiple of the fundamental frequency. The non-fundamental frequency components of the supply voltage and load current are termed harmonics and the overall distortion is termed harmonic distortion. It is of note that current harmonics are the cause and voltage harmonics the affect. Thus in order to prevent voltage harmonics interfering with the operation of parallel-connected equipment, the current harmonics must be reduced to an acceptable level by filtration. Figure 5 illustrates the frequency components of the current waveform that result in the supply system that feeds a DC rectifier. Because voltage harmonic distortion arises through voltage drops created in supply system impedances, high impedance systems – such as those found in marine use – are more 0V DC One phase output connection -V DC Figure 4: NPC Topology simplified schematic of a NPC topology. As can be seen an artificial neutral voltage – obtained by a capacitor ladder bridge – clamps the inter-device voltage via diodes such that the maximum voltage seen across the switches is half the circuit maximum. If the converter’s devices are able to withstand half the circuit voltage then any need to switch them in synchronism is avoided. At present converters rated at 30 MVA are achievable with the NPC topology. As well as providing a robust converter design NPC converters are also inherently more efficient as the devices switch through lower voltage differentials and thus the switching loss is reduced. A final advantage – again accruing from the reduced voltage swing – is that the output waveform more closely approximates to a sinusoid; it contains a lower harmonic content. It is of course not necessary to limit the clamping voltage to the mid point of the DC link voltage alone, more extensive capacitive networks can generate any desired number of intermediate voltages which can then be used to asynchronously operate any number of switches in a converter limb safely, the converter is then termed a diode clamped converter. However the advantages offered by increasing the number of levels offers reducing returns with respect to the quality of the waveform and the efficiency increases gained by the reduction of the switching loss are rapidly overtaken by susceptible to voltage distortion and one of the perennial challenges for the marine power system integrator is to predict the levels of harmonic distortion at the design phase so that suitable counter measures such as harmonic filters can be incorporated in order that the supply system retains an adequate level of power quality. The size of harmonic filtration required in any given marine power system is clearly a system level issue but it is rarely insignificant. For a typical IFEP system with the ships service system interconnected to the propulsion system by simple transformers the harmonic filters will occupy around 60% of the volume of the propulsion converters themselves. This adds weight and cost and reduces overall system efficiency. Hence the harmonic performance of any given converter design is a crucial issue. dV/dt: The output of a converter is often used to drive a propulsion motor and here – particularly for compact marine propulsion – the performance of the motor insulation under the PWM waveform generated by the converter is crucial. The motor’s winding insulation needs to withstand the sequence of steep sided pulses of voltage emulating the required sinusoidal voltage if failure is not to result. The most crucial aspect of the voltage waveform with regard to insulation stress is the rate of change of voltage and PWM converters are capable of extremely high rates of change of voltage. This aspect of insulation degradation and potential failure is often, on first thought, found to be surprising. Nevertheless insulation failure is one of the commonest reason for failure in the several compact propulsion motor developments that are taking place in both Europe and the United States of America. It currently appears that a peak voltage of around 5kV is a maximum –at least empirically. This limit also sets the DC link voltage in a PWM converter and therefore the United States medium voltage standard of 4.16 kV is attractive to marine system designers as it provides around 5 kV when rectified. Because the rate of change of voltage as seen in a converter’s output is a key contributor to the stress and resultant degradation of the motor insulation many converters use output filters to reduce their rates of change of voltage. Occasionally these output filters are designed to remove the majority of the output harmonics and they may then be termed sinusoidal filters. However, more commonly, the output filter is designed only to limit the rate of change of voltage to a specified level and the filter is then termed a dV/dt filter. dV/dt filters are naturally much smaller than sinusoidal filters although the exact size – and thus their cost and the amount by which they reduce overall system efficiency – is one of the key system design considerations. Motor Regeneration: Because marine electrical propulsion systems drive vehicles that gain kinetic energy as they move, the maneuvering of ships is complicated by the need to dissipate the stored kinetic energy when reducing speed. The interaction of the propeller with the slipstream of the water passing it further complicates the issue. In general when wishing to reduce speed, simply reversing the direction of rotation of the propeller, or even just stopping it, is never the best strategy. The best thrust in the opposite direction to the ship’s motion is achieved by turning the propeller at just less than synchronous speed – that is at just less than that rotational speed which would match propeller advance and ship speed when considering the propeller as a simple screw. When this is done, as well as the thrust reversing so does the torque on the shaft and therefore so does the power flow from the motor that starts to regenerate power back into its converter. The problem of controlling and dissipating the regenerated power during maneuvering is a significant issue for the system integrator in the early phases of the design and it usually required as dedicated dynamic braking resistor and controller so that the significant regenerated power does not destabilize the upstream power system. Switching Frequency and Switching Loss: The higher the switching frequency the better the quality of the voltage waveform supplied to the load and thus the current it draws. This has a direct impact on noise and vibration and also on the filtration requirement of the converter output. Ideally the marine propulsion system designer would like to operate at the switch’s maximum frequency. However each switching cycle represents an energy loss as the voltage across the switching device builds up at the same time as the current decays and thus there is energy dissipated 2.5 2 1.5 1 0.5 0 0 5 10 15 20 25 30 35 -0.5 Time Volts Current Power Energy Figure 6: Switching Loss within the switch. In order to limit the switching loss current-day marine propulsion power electronic converters are limited to around 2kHz – far below the theoretical capability of modern IGBTs. Figure 6 illustrates the switching loss inherent in a forcecommutated device. Reduction of switching loss is one of the ambitions of current converter development. VI. EXAMPLES OF MODERN MARINE POWER ELECTRONIC CONVERTERS Alstom Series Connected Converter: Alstom developed the first high power marine power electronic PWM converter based on series connected IGBTs to provide the necessary voltage withstand for a 25MVA Disk 3 Outer Supply Bridges Filter Filter Filter Filter Inner Disk 4 Outer Inner Power Paragon (a part of L3 Communications) which uses 5 intermediate voltage levels (again generated by a capacitor bridge). DC Link SIGMA 1 AC Supply SIGMA 2 Channel 1 Channel 2 Figure 9: Power Paragon Diode Clamped Converter Filter Outer Disk 1 Filter Inner Filter Outer Disk 2 Filter Inner Figure 7: Alstom Converter requirement. The main technical challenge was synchronizing the switching of the IGBTs so that the situation where insufficient devices were attempting to withstand the system voltage was avoided and also providing robust voltage sharing circuits so that each IGBT was acceptably stressed. The general modular topology of the Alstom Converter is shown in Figure 7. The Alstom converter development has been a significant success and has been used by both the United States of America and the United Kingdom within their current Naval programmes. Voltage Clamped Converters: The NPC topology has been developed by ASI Robicon of the United States of America and also by PMES of the United Kingdom. Figure 8 illustrates a NPC converter. An NPC converter is, of course, the simplest case of a multilevel converter using three voltage levels and Figure 9 illustrates a Diode Clamped converter developed by DCPOS Isolated Voltage Converter: Power Paragon and ASI Robicon (a division of the USA based High Voltage Engineering Corporation) have each conceived a type of multi-level converter that does not rely on a capacitor network to generate intermediate clamping voltages. Instead a transformer with a single primary winding and multiple secondary windings is used to create electrically isolated voltages which can then be independently switched by IGBTs or other power switches which are nominally series connected on the output side. Although the converter tends to be relatively large the topology does offer the possibility of generating extremely accurate sinusoidal output voltages through the use of interleaved switching across the multiple modular switches. The converter topology exhibits an excellent harmonic distortion performance and this can offset its larger volume through the reduced need for harmonic filtration. VII. FUTURE MARINE POWER ELECTRONIC CONVERTERS Resonant Converters: Resonant Converters are a class of converters that offer great benefit for the future. The concept is that an auxiliary circuit around the main power switch creates a resonant flow of current in a circuit that forces either the switch current or voltage to be near to zero during the commutation interval. In this way the switching loss is largely removed because the volt-amp product is also near to zero. When the current is held near to zero the circuit is said to be current resonant, conversely when the voltage is held near to zero the circuit is said to be voltage resonant. Current resonant circuits resemble the external commutation circuits used with thyristors – and indeed they provide the same function, the load current is diverted out of the switch. Voltage resonant circuits resemble passive IGBT Gate Drive PEC IGBT Gate Drive PEC IGBT Gate Drive PEC IGBT Gate Drive PEC OUTPUT IGBT Gate Drive PEC IGBT Gate Drive PEC IGBT Gate Drive PEC DCNEG IGBT Gate Drive PEC Figure 8: PMES NPC Converter snubber circuits – the main difference now being that the voltage resonant circuits operate in advance of the switching transient whereas the snubber circuit follows behind. In both cases the timing of the firing of the auxiliary resonant circuit is crucial in relation to the timing of the commutation of the main switch. Once the switching loss is largely removed the designer has a choice between increasing converter efficiency, increasing converter switching-frequency, increasing converter current output (so that the conduction loss rises to replace the reduced switching loss) or perhaps a combination of the three. There is however a problem with resonant conversion for marine propulsion uses. As previously explained marine propulsion systems operate for considerable periods at part load and in this condition the converter’ switching loss is significantly reduced anyway. However the additional passive circuit losses introduced by the resonant circuitry remain at the same level as if the converter was at full power. Thus a marine propulsion converter using resonance can actually increase overall losses rather than reduce them. One answer is to design the resonant circuits so that they can be switched out of operation once their losses outweigh the savings – however this can only be achieved for current resonant converters and these are the more bulky and expensive version of resonant converter. SPCo Development: An innovative form of multi-level converter is being developed by SPCo of the USA where MOS Turn Off Thyristors (MTO) switch a base voltage between various intermediate levels and this is then used as a PWM voltage source by a final resonantly switched IGBT based output stage. This converter ought to offer improved efficiency since both the switching and conducting losses are significantly reduced. The switching losses are reduced because the MTOs controlling the base voltage switch infrequently and the IGBTs performing the final PWM modulation switch resonantly. The conducting losses are reduced because the MTOs – which replace IGBTs in comparable topologies – are thyristor based and therefore exhibit a very low forward conducting volt drop. Figure 10 illustrates the SPCo converter. Matrix Converter: Another form of converter under development is the Matrix Converter and this is receiving significant attention in both the USA and UK with much work being conducted by the UK’s Nottingham University as described at . The Matrix Converter gains it name from the appearance of the converter’s electrical connections. When drawn as shown in Figure 11 the nine bi-directional switches 3 Ph Input Bi-Directional Switches 3 Ph Output Figure 11: Matrix Converter appear as a matrix of connections. The bridge produces any desired output waveform by connecting each of the input phases (VA, VB, and VC) to each output phase (Va, Vb, and Vc) in turn within a switching interval of fixed duration. Within the fixed switching interval the periods of output-connection for the three input phases is varied in a manner similar to PWM such that the desired output is produced in terms of the average of the input voltages. In order that any desired output voltage can always be produced without regard to the instantaneous phase of the three input voltages the output voltage must be limited to a level below the input voltage envelope. As can be seen from Figure 12 300 200 100 Soft-Switching Section Volts 0 0 0.002 0.004 0.006 0.008 0.01 0.012 0.014 0.016 0.018 -100 -200 -300 Time (s) IGBT 3300-V 1200-A Figure 12: Matrix Converter Voltage Envelope (1) 7-kVDC 5-Level Super GTO 5000-V 3000-A Super GTO 2500-V 1500-A Figure 10: SPCo Converter the input voltage envelope restricts the output voltage to 50% of the input. The minimum of the maximum (positive) is half of the peak value, occurring when the two positive voltages are equal. Similarly the maximum of the minimum (negative) is half of the peak value, occurring when the two negative voltages are equal. This is a serious limitation for the Matrix Converter when it is intended for use in a standard power system with standard motors. However it may be overcome by using one of two differing techniques. The first is to distort the desired output phase voltages by use of a combination of third harmonics of both the input voltage frequency and the desired output frequency. The required additional harmonics are: Input Voltage Third Harmonic: -1/6 Output Voltage Third Harmonic: +√3/6 When this is done the phase voltages are as shown in Figure 13 and the peak desired output voltage may be raised to 0.866 of the input. Thus the maximum output 300 200 100 0 0 0.002 0.004 0.006 0.008 0.01 0.012 0.014 0.016 0.018 -100 -200 -300 Time (s) Figure 13: Matrix Converter Voltage Envelope (2) voltage can be increased from 50% to 86.6% an increase of 36.6 percentage points or 73.2%. Two important points are worth noting with regard to this technique. First, although the phase voltages are distorted this does not appear in the output line voltages because of the natural third harmonic cancellation that occurs in a balanced three-phase system when moving from phase to line voltages. Second, this additional voltage increase has not been achieved at any other performance aspect of the converter, its overall efficiency remains unaltered as does the quality of the output voltage and the level of distortion imposed on the input system. The second technique uses a fictitious DC link and divides the modulation function into two stages, the first deals with input voltages, and the second with the generation of the output voltages. It is termed a fictitious DC link because in order to maximise the output voltage the first modulation stage chooses to work between the most positive and most negative input voltages, as would a standard uncontrolled DC rectifier. The overall maximum voltage output that can be achieved with this technique is 6√3/π2 or 105.3%. Although the modulation function is developed by considering two distinct phases of time-continuous operation this cannot be the case when the modulation function is applied to the converter – there is only one switch between the input and the output and no intermediate stage. In practice the two separate switching strategies are combined into one unified requirement before the modulation function is applied. Techniques to achieve this are covered at  and . There are however significant disadvantages. Although this technique overcomes the voltage limitation of the Matrix Converter completely, this gain is bought at the expense of the overall harmonic performance of the converter: the harmonics reflected into the input voltage or generated in the output current (or indeed both) must increase. It is perhaps not surprising - since the modulation function is in part derived through consideration of DC rectification - that the largest increase in harmonics are those associated with this process itself (5th, 7th, 11th etc). An additional source of harmonic distortion arises when the voltage is forced above 86.6%, when this is done it is no longer possible for the average output voltage in each switching interval to equal the target voltage and additional low frequency harmonics result. It is interesting to note that a Matrix Converter operating at minimum harmonic distortion under a fictitious DC link scheme will be subject to the same voltage limit as a converter operating under the third harmonic strategy. There are practical difficulties in developing the overall modulation function through two stages in real time so that implementation of a converter producing continuously varying frequency and voltage (as required in IFEP applications) would be difficult. Clearly a Matrix Converter would benefit from a symmetrical bi-directional switch. SAIC Multi-Port Inversion: SAIC – and in particular Dr Rudy Limpaecher – have been developing an extremely innovative converter termed the Multi-Port Converter. The circuit schematic diagram for an MPC converter is shown in Figure 14 together with the current waveforms for one charge and discharge cycle at Figure 15. The technique has been more fully explained at ,  and  but, in summary, it utilises Input Redistribution Output Volts Filter Figure 14: SAIC Multi-Port Converter Filter the fact that in any balanced multi-phase system the Ici,I1i 1200 1000 800 600 400 200 0 0 100 200 Vc I3o 1000 Capacitor Voltage (V) I3i 500 0 Charge Currents (A) natural commutation – and extremely good harmonic performance both with respect to the quality of the waveform offered to the motor and the level of harmonic pollution reflected back into the supply system. VIII. CONCLUSION The development of marine electrical power systems has been extremely rapid over the last two decades and this has been due to developments in the topology and construction of both power electronic switches and power converters themselves. These under-pinning device and equipment developments have formed the enabling technology for the implementation of IFEP systems in both warships and commercial vessels. As such the power electronic community has exerted a revolutionary effect on marine engineering resulting in a common development thread and ambition across the world. ACKNOWLEDGMENT The author acknowledges the support of Rolls-Royce plc and the many other companies and corporations without whose help this paper could not have been written. REFERENCES  Dr Jon Clare, Dr Pat Wheeler, “Matrix Converters Study”, UK MoD IFEP Report, September 1999 unpublished.  Ziogas PD, Khan S I and Rashid MH, “Some Improved Forced Commutated Cycloconverter Structures”, IEEE Transactions on Industrial Electronics Vol 1A-21 No 5, September - October 1985, pp1242-1253.  Ziogas PD, Khan S I and Rashid MH, “Analysis and Design of Forced Commutated Cycloconverter Structures with improved Transfer Characteristics”, IEEE Transactions on Industrial Electronics Vol 1E-33 No 3, August 1986, pp271280.  Cdr C G Hodge and Cdr D J Mattick, ’The Electric Warship III’ Trans IMarE, Vol 110, Part 2, The Institute of Marine Engineers (1998).  Cdr J M Newell, Cdr D J Mattick Royal Navy and C G Hodge, ’The Electric Warship IV’ Trans IMarE, Vol 111, Part 2, The Institute of Marine Engineers (1999).  C G Hodge and D J Mattick OBE, ’The Electric Warship V’ Trans IMarE, Vol 112, Part 2, The Institute of Marine Engineers (2000). I2i Ico,I2o 300 400 500 600 -500 -1000 µsec Ico,I1o Charge Cycle Disc harge Cycle Figure 15: Multi-Port Converter Waveforms main phase currents at any time sum to zero, simplistically: for any given time interval there will have been as much positive current as negative flowing in the circuit. The charges delivered and received balance precisely. Hence these positive and negative currents can all be supplied from a single capacitor whose positive plate and negative plate charges self evidently always sum to zero. When considering a 3 phase to 3 phase MPI converter within the time intervals of its operation; there will always be a phase which delivers, or receives the highest charge, while the remaining two phases are of opposite sign and combine to balance the overall charge transfer. Therefore, when operating, one input or output phase is connected to one side of the capacitor throughout the charge or discharge cycle while the other two are Central Capacitor Charging Inductor InputThyristors Freewheeling Thyristor Discharging Inductor Input Filter Capacitor Input Inductor Output Thyristors 1.45 h X 1.27 d X1.98 w = 3.64 cu meter Figure 16: Conceptual Multi-Port Converter connected in turn to the opposite plate. The only control requirement during this phase is to determine at which point the two minor phases should be commutated. Figure 16 shows the general arrangement of a conceptual MPI. The general operating principles have also received independent endorsement from third party assessments. The main advantages of this converter topology are very low switching losses – all switching is achieved by thyristors using un-forced


Thesis submitted in fulfilment of the optical amplifier is required to overcome the limitations of conventional erbium-doped fiber amplifier besides optical . Thesis for the degree of master of science effects of optical filtering on signal characterization in coherent systems (edfa) makes it possible to transmit . Legacy course catalog edfa 200 - history & phil of educ: purdue west lafayette traditional 08/23/1999 - 08/03/2001 edfa 699a - res phd thesis abs:. The growing use of anti-anxiety pills reminds some doctors of the early days of the opioid crisis considered relatively safe and non-addictive by the general public and many doctors, xanax . Thesis for the degree of doctor of philosophy september 2015 i university of southampton 223 modelling of multimode erbium-doped fiber amplifier .
Abdul mutalip, for her assistance and guidance toward the progress of this thesis project current spacing of erbium doped fiber amplifier (edfa) is in the . Distributed raman amplifiers is simulated in raman/edfa hybrid amplified systems the discrete ra will be in a dispersion compensation module the ratio of the signal snr, rsnr, at the end of the contrasting passive and active systems is the final measurement of system benefit of adopting raman amplification. Analysis of wdm network based on edfa pumping and dispersion compensation using optisystem a thesis submitted in partial fulfillment of the requirements for the degree of. Reduction of edfa optical power transients using power shaping by james trent jackson a thesis submitted in partial ful llment of the requirements for the degree.
Christopher c information for applicants with disabilities, thesis on edfa research. Performance analysis of erbium-doped fiber amplifier in fiber optic communication technique strictly as per the compliance and regulations of performance analysis of erbium-doped fiber. Thesis/dissertation acceptance this is to certify that the thesis/dissertation prepared by entitled for the degree of is approved by the final examining committee:. The theme and structure of philippians 235 eadie suggests, the transitions depend upon no logical train — as the thoughts occurred they were dictated.
Supervisor and a co-investigator in the edfa project reported in this thesis mr saravanabhavan took dr r stephen brown’s guidance throughout this thesis work 2. Dissertations by students “pumping schemes for high concentration erbium-doped fiber amplifier (edfa),” ms thesis, kenji konno, april 2002 . In this thesis, ﬁber raman ampliﬁers (fras) are investigated with the pur- (edfa) to support longer spans, and the use of a hybrid wide-band dcra/edfa to . If there are reservations about the thesis in terms of emerging research design problems, change in direction, data collection problems, analysis problems or analysis .
Tuesday, july 31, 2018 home upcoming events / trainings / speaking affiliate events: symposium & leadership training. A study of erbium doped fiber amplifier (edfa) amplifier’s characteristic and fwm in an optical network using optiwave optisystem simulator thesis full-text available. “performance analysis of transient aspects for edfa amplifiers” a thesis submitted in partial fulfilment of the requirement for the award of degree of.
Home help with a thesis statement about education pdf help with a thesis statement about education pdf outdoor mounted edfa for rfog with a two-way 1310 nm return. Edfa is preferred to be employed in the befl system in this thesis, the befl signal is generated in ring and linear cavities with channel spacing of 009 nm. Design and development of erbium doped fiber amplifiers a project report submitted by edfa erbium doped fiber amplifier esa excited state absorption . The information obtained is the basic configuration of optical amplifier in optical transmission link, advantages and disadvantages of erbium doped fiber amplifier, the amplified spontaneous emission noise (ase) and etc.
This thesis describes theoretical and experimental studies on two subjects: first is characterization, design and modeling of erbium-doped fiber amplifiers (edfas) second is the effect of fiber dispersion on the noise of distributed feedback (dfb) lasers and the impact of this effect on the performance of 1550nm video lightwave transmission . Major papers & theses for 2000 : 2000 carol-ann belanger: an investigation of the negative aspects of the twinning process from the principal's perspective :. Effect of edfa based various optical amplifier configurations on isowc system surinder singh, harpreet kaur department of electronics and communication engineering.


HTC-1 Electronic Temperature And Hygrometer
- Have a large LCD display
- Display temperature and humidity
- ℃ and ℉ can switch
- The clock shows in 12/24 hours
- The function of the maximum and minimum temperature and humidity in memory
- The function of the strikes the hour
- The function of alarm clock every day
- Display the calendar
- Temperature Range: －50℃～＋70℃(－58℉～＋158℉)
- Humidity Range: 10%RH～99%RH
- Acuteness of display: Temperature: 0.1℃ (0.2 ℉); Humidity: 1%RH
- Accuracy: Temperature: ±0.1℃ ; Humidity: ±5%RH
- Voltage: 1.5V
1. The function of the key-press
【MODE】can switch the hour and minute/setup the time、alarm clock、12 or 24 hour、date; 【ADJ】 the adjustment is established the project the value; 【MEMORY】display and clear the memory of the maximum and minimum temperature and humidity; 【℃/℉】 switch the ℃ and ℉; 【RESET】clear all setup and memory, return the Original state
2. In the original state press 【MODE】2S, when the minute flickered, press 【ADJ】 can adjust minute, continuance pressing【MODE】can setup “clock”、“12/24”、 “month” and “date”.
3. When in the clock mode , press【MODE】one time, display clock mode, in this time press【ADJ】can change alarm function/ hour alarm function open and close. Press【MODE】2S again, can setup the alarm time, and open the strikes the hour.
4. When in the alarm mode , if no people to setup after one minute can return the currently clock, in this time press【ADJ】can display the calendar, after 3S can return the currently clock. Press MAX/MIN, can display the maximum temperature and humidity after the last clear.
5. Press【MEMORY】can display the maximum and minimum temperature and humidity in the memory, Press【MEMORY】more than 2S can clear the maximum and minimum temperature and humidity in the memory.
*Note: The first use and change the battery please press【RESET】


From FierceHealth IT (Stroke patient makes gains in speech, physical therapy with robot)
Researchers at the University of Massachusetts-Amherst are touting success in the case of a robot that delivered speech and physical therapy to a 72-year-old male stroke patient.
“It’s clear from our study … that a personal humanoid robot can help people recover by delivering therapy such as word-retrieval games and arm movement tasks in an enjoyable and engaging way,” speech language pathologist and study leader Yu-kyong Choe said in an announcement.
While the child-sized robot might not be the ideal therapist, it could help ease the shortage of workers, especially in rural areas.
“A personal robot could save billions of dollars in elder care while letting people stay in their own homes and communities,” the authors wrote in a study published in the journal Aphasiology.
To me it’s a no brainer to use robots for rehab. Take the phrase “arm movement” tasks. Robots can be much better than human therapists at doing boring, repetitive arm movement tasks over long periods of time. And of course if the robot can be the patient’s home it makes access all the easier.
In 10 years we’ll look back at these early results and it will be totally obvious the direction things were moving.March 21, 2013


We take our quality control very seriously and as such we’ve invested in this fantastic product from the IM series. It provides instant measurement with simple, easy and automatic operation. It uses a cutting edge dimension analysis system which defies traditional metrology techniques.
It can take up to 99 simultaneous measurements within its 200mm area. measuring area all at once within a few seconds. Measurement values do not vary, depending on the operator. So human error is irradicated. It has a very large depth of field of 20mm (= +/- 10mm). Achievable repeatability is +/- 0.5um and has an accuracy of +/- 2-5um. Excellent reporting as measurement data are saved automatically and statistics can be reviewed as well as all captured images.


MCS Smart Calibration is the calibration lab you can count on for affordable calibration services with a quick turnaround. Our calibration lab is based in North Wales, St Asaph. We provide calibration services across the UK and Ireland.
Calibration is becoming more and more important as international requirements are becoming stricter. Compliance and qualification testing require traceable proof of the performance of the equipment used for testing and measurement.
Why Choose MCS smart calibration?
Our calibration team have over 20 years of calibration experience in the RF and microwave calibration industry. We are also a leading distributor of some of the most well known test equipment manufactures, such as Cobham, Rohde & Schwarz, Litepoint and many more. All of our calibrations are fully traceable and you can track your instrument(s) calibration progress through our free online management tool.
We are continuously growing our calibration lab to allow us to calibrate a wider range of instruments and a higher frequency range. Take a look at our calibration capabilities table below to see our current capability range.
We have a quick turnaround time of 5 working days if you decide to use our basic calibration service, or 2 working days if you choose the express calibration service.
The table below currently outlines our calibration capabilities. For more information, please contact us via phone or email and we would be more than happy to help.
|Spectrum Analysers (Bench & Handheld)||Up to 26.5 GHz|
|Signal Generators||Up to 26.5 GHz|
|Power Meters||Up to 26.5 GHz|
|Power Sensors||Up to 26.5 GHz|
|Radio Communication Test Sets||Up to 1 GHz|
|Network Analysers||Up to 26.5 GHz|
|Oscilloscopes||Up to 18 GHz|
|Power Supplies||Up to 1000 Volts|
|Multimeters (Bench & Handheld)||Up to 1000 Volts|
|Frequency Counters||Up to 26.5 GHz|
Here at MCS Smart Calibration we have always worked to the principles of the ISO/IEC 17025 standard, to ensure that your RF and microwave equipment is calibrated to the correct degree of accuracy and in a fully competent and consistent manner.
As part of our commitment to this standard, this month sees us welcoming UKAS on site here in St Asaph to assess our calibration lab. This will hopefully lead to our official UKAS accreditation in Spring 2018 for electrical and RF calibrations.
Want more information about our Calibration Lab? contact us via one of the methods below.
Phone: +44 (0)8453 62 63 65


Silicon Laboratories CP2110 based USB
uslhcom* at uhidev?
ucom* at uslhcom?
uslhcom driver supports USB HID (Human
Interface Device) based serial adapters. The following devices are
- Silicon Laboratory CP2110
The driver acts as a bridge between uhidev(4) and the ucom(4) driver which makes it behave like a tty(4).
tty(4), ucom(4), uhidev(4), usb(4)


What Is EMF Exposure ?
EMF stands for electromagnetic field which is found in an area of moving electrical charges. It is mostly produced in areas where appliances that use electricity are found. EMF exposure is a situation that cannot be prevented because its fields of generation are almost everywhere. It is generated from the usage of appliances like microwaves, cell phones, powerlines, transmitters, and broadcasting towers.
Some scientific researchers think the EMF is harmful to health while others do not believe it. The EMF radiation can either be from handmade sources while some EMF radiation occurs from manufactured sources. Radiation depends on the level of frequency and wavelengths.


DSP-Z8, DSP-Z8III, DSP-Z6III, our 3rd generation of digital processing and the Zapco Digital Processing amplifiers. Great sound, clean Zapco power, and stealth fighter looks. The DPN is easier to load and use and the hassles of loading drivers are gone. Just drop the new system onto your desktop and go.
(2011 to 2015) DSP-Z8, Z8 III, Z6 III, DC Series
Download: DSP-Z8/DSP-Z8 III/DSP-Z6 III Manual - DPN Software v.10.0.0.1 - Software Updating Guide to v.10.0.0.1
Download: DC Series Manual - DC Series Introduction
Early (2011) DSP-Z8 and 2nd Gen DC Amplifiers with RCA inputs
The first of the DSP-Z8s, with serial numbers 0001~0500 and the DC amps with RCA inputs use the DPN 200ms program that you can find here: DPN 200ms
(2005 to 2010) DSP-Z6, DRC-SL, 1st Gen DC Amplifiers with SymbiLink inputs
The first ever full function digital processor for the car, with a full line of amplifiers with full function on-board processing.
Download: DPN Software v 1.41 (including 64bit Drivers, and Instructions)


Session SH019: Particle Acceleration and Transport at the Sun and in the Inner Heliosphere
Conveners: Linghua Wang, Dick Mewaldt, Gang Li, and Robert F Wimmer-Schweingruber
Session Description: An important topic of solar and heliospheric physics is to understand the acceleration and transport of nonthermal particles. Such studies in the inner heliosphere encompass a variety of processes leading to the formation of solar wind suprathermal particles, solar energetic particles, energetic particles from Corotating Interaction Regions, etc. However, many details of the acceleration and transport process of these energetic particles still remain unknown. Particle acceleration processes include magnetic reconnection, wave-particle interactions, collisionless shock waves, etc., and particle transport processes include adiabatic cooling, parallel and perpendicular diffusion, random walk of magnetic field lines, etc. This session invites contributions that discuss space-borne and ground-based observations, and theory/modeling of the processes pertaining to particle acceleration and transport at the Sun and in the inner heliosphere.


In this chapter, we will provide a brief explanation of the principle of optical coherence tomography (OCT) imaging and highlight the influence of the light source properties. We will discuss the application of semiconductor lasers in specialized light sources for OCT, namely, in broadband light sources and in broadband wavelength-swept light sources. We will conclude with an outlook on the continuing development of light source technologies for OCT.
|Title of host publication||Semiconductor Lasers and Diode-based Light Sources for Biophotonics|
|Editors||Peter E. Andersen, Paul Michael Petersen|
|Publisher||Institution of Engineering and Technology|
|Publication status||Published - 2018|


Where is the speaker fuze in a 2001 GMC Sierra? The underhood fuse block in the engine compartment on the driver’s side of the vehicle near the battery. Where is the radio fuse in a
Where is the speaker fuze in a 2001 GMC Sierra?
The underhood fuse block in the engine compartment on the driver’s side of the vehicle near the battery.
Where is the radio fuse in a 2008 Chevy Silverado?
The radio fuse in the Chevy Silverado is in the engine compartment fuse box which is a weird location compared to most other vehicles. Normally You would find it in the interior fuse panel under the driver side of the dashboard instead of under the hood. It is a 15 amp fuse located in the lower right of the panel.
Where is the radio fuse for a 2001 Chevy Silverado?
The fuse box is located on the driver’s side of the instrument panel, behind the cover.
Where is the fuse box on a 08 GMC Sierra?
The fusebox is located in the engine compartment, on the driver side of the vehicle.
What is the ETC fuse for?
Electronic throttle control (ETC) is an automobile technology which electronically “connects” the accelerator pedal to the throttle, replacing a mechanical linkage. The electric motor is then used to open the throttle valve to the desired angle via a closed-loop control algorithm within the ECM.
What is a TBC fuse?
The TBC Fuses stand for the Body Control Module(BCM) unit. Not the the Throttle Body Control.
What is PDM fuse?
The PDM – Power Distribution Module is a low voltage (12 to 30V AC/DC) power distribution module designed to take a single power source and distribute that power to multiple circuits. Each circuit includes an On/Off switch, field connection terminals, 3 amp circuit breaker or 3 amp fuse, power LED and fault LED.
What does the TBC fuse control?
Welcome to the forum. The TBC (truck body computer) fuse powers the body control module (BCM). They rarly go bad. They use 5 volts dc so an accidental hit (short) of 12 volts will blow the fuse.
Where is the center instrument panel fuse block?
The center instrument panel fuse block is located underneath the instrument panel, to the left of the steering column.


6 Prong Plug Service
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See what's needed for banks to improve big data analytics systems and its increased scope
Banks that tap into big data trends and craft strategic advances are leaders in the truest 21st-century sense. But, identifying trends and aligning them to business goals is not the only task at hand. One pressing requirement is – a bank’s current infrastructure needs to keep up with the pace of advancement.
For current-day systems, big data analytics is a business’ catalyst in better understanding consumers and the lengths of operational possibilities. Essentially with infrastructure upgrades like cloud computing becoming mainstream, and real-time access to big data becoming a reality, strategizing has evolved ten-fold.
Multiple analytics providers have ready-made solutions to tackle the current requirement. But, for Banks looking to ace analytical functions in the now and the near future, business leaders need to ready system architecture for capabilities trending in other businesses too.
Which Trends Should a Bank's Analytics Systems Ace?
Add big data to the equation, and the need for faster data processing becomes a priority. Real-time data processing can be leveraged in multiple scenarios, and since everything is going digital henceforth, knowing the heights that transformation will reach help prioritize.
The vast applications of data analytics and rise in DevOps teams are a result of improving data science approaches for big data generation. In maximizing results from data, here are a few trends your lenders' technology partners need to look out for –
Increasing the Role of Alternative Data in Analytics
Some major applications gaining ground are data enrichment to enhance underwriting, smart lending and credit scoring, and historic data for forecasting and predictive algorithms.
Data as a Product (DaaP) with Data Subscriptions
Data as a Product (DaaP), facilitated through Data Subscriptions, helps banks and lenders with pre-sourced good data without the hassle of revamping data collection infrastructure.
Hybrid clouds for Improved Interconnectivity
A hybrid cloud is an IT infrastructure that connects public clouds and/or private clouds to offer orchestration, management, and application portability while creating a single, optimal cloud environment.
Banking Functions that Leading Analytics Systems Tackle
Leading big data analytics systems offer actionable insights. The systems enable banks to draw conclusions about the segmentation of customers, better understand transaction channels, collect feedback based on reviews, and assess possible risks to prevent fraud.
Currently, leading big data analytics systems for Banks and Lenders are –
Early Warning Signal Solutions enable predictive analytics to help banks predict defaults long before they happen. These systems require data subscriptions for quality inputs on the borrower's financials, transactional behavior, market position, and other business factors.
The 'advanced analytics' system uses artificial intelligence (AI), machine learning (ML), and neural linguistic programming (NLP) models to collect and process the information on potential defaulters, helping banks strategize for the best recovery practices.
Risk-Based Supervision is a prescribed model for regulatory supervision of Financial Institutions around the world. Reported data is expected to be quantitative as well as qualitative, and is broadly expected to cover categories – capital, credit, market, earnings, liquidity, business strategy, operational risks, internal control, management, and compliance risks.
An RBS System equips Banks with enhanced compliance and risk management practices, with the added advantage of a comprehensive MIS system for internal decision making.
Management Information Systems with Automated Data Flow (ADF) for Regulatory Reporting offers the highest quality of data to business leaders as well as regulators, with a single system. New-age MIS systems for Banks and Financial Institutions are benefitting from the regulator-mandated automated data flow with the creation of ‘golden datasets’.
Golden datasets are clean, validated, integrated datasets, which lets businesses identify function-specific use cases for data and put processes in place to join or reconcile, and ultimately use the exact data for multiple functions.
Insight Generation and Research Tools for Regulatory Reporting offer actionable data for IRAC Norms, Ind AS Reporting, and IGAAP Reporting. Automation of multiple data collection processes uses data available systems for analytics. Systems for insight generation utilize integrated solution architecture, multiple data sources, and data lakes, and also deploy advanced Artificial Intelligence (AI) and Machine Learning (ML) for higher-quality data.


What is the procedure for turning on the touch screen on the Lenovo Yoga?
- Press the Windows logo key plus the letter X. Device Manager may be found in the drop-down menu. To see the full list of Human Interface Devices, click on the small arrow next to the word “Human Interface Devices.” Select the touch screen driver from the drop-down menu (in my case, NextWindow Voltron Touch Screen). Select Disable from the drop-down menu by right-clicking.
- 1 Does Lenovo Yoga have HDMI input?
- 2 Does Lenovo have HDMI port?
- 3 Does Lenovo monitor have HDMI port?
- 4 What ports are on a Lenovo Yoga?
- 5 Does yoga c930 have HDMI port?
- 6 How do I change my Lenovo to HDMI?
- 7 Which Lenovo Yoga has a HDMI port?
- 8 How do I connect my Lenovo Yoga 7i to an external monitor?
- 9 Does Lenovo Yoga 720 have HDMI input?
- 10 How do I get my Lenovo to recognize my second monitor?
- 11 How do I use HDMI on Lenovo all in one?
- 12 How do I connect two monitors to my laptop with one HDMI port?
Does Lenovo Yoga have HDMI input?
The latest Lenovo Yoga tablet includes an HDMI port, allowing you to connect your console while on the road.
Does Lenovo have HDMI port?
The VGA, DVI, or HDMI port can be found on the back or side of the ThinkPad computer. VGA video-out ports are colored blue, whereas DVI video-out ports are colored white. Some ThinkPad notebooks, particularly those from the latest generation, contain HDMI connections that look similar to a huge USB port.
Does Lenovo monitor have HDMI port?
Connect the dots in your own manner. Lenovo monitors are equipped with a variety of connectivity choices, including Video Graphics Array (VGA), HDMI 1.4, and DisplayPort (DP) 1.2, among others.
What ports are on a Lenovo Yoga?
Following ports are available on the Lenovo Yoga Slim 7i (15″) for the year 2020:
- 1 × Thunderbolt 3 USB-C port DisplayPort 1.4b, ThunderboltTM 3.0, and Power Delivery 3.0 are all supported. There are two USB 3.2 Gen 1 connectors on the board. The following features are included: 1 x Full-size SD Card Reader.
- 1 x HDMITM 2.0b
- 1 x Audio jack
- 1 x Power adaptor.
Does yoga c930 have HDMI port?
The number of connectors is limited, but just acceptable: two USB-C ports (one of which is used to charge the device) and a conventional USB 3.0 port are provided. A media card slot and, more importantly, an HDMI output are also absent from the device, which means customers using external displays will have to rely on the second USB-C port for visual output.
How do I change my Lenovo to HDMI?
Press the “Input” button on the TV remote control to select between the HDMI input, the VGA input, and the S-video input if you have a standard-sized television. When the S-video input on a regular television is selected, the laptop desktop will be instantly shown on the TV screen when the input is changed.
Which Lenovo Yoga has a HDMI port?
Yes. The Lenovo Yoga Tab 13 (YT-K606F) has an HDMI connector for connecting to a television. The HDMI port is positioned on the tablet’s left bottom side, on the left side of the tablet’s bottom. It is recommended that users connect their HDMI devices using the included Micro HDMI to HDMI cable.
How do I connect my Lenovo Yoga 7i to an external monitor?
1-2 of 2 Possible Answers
- Because of this, the laptop does not include an inbuilt HDMI port. It is not unusual for newer, slimmer computers to have this problem. The Lenovo Yoga 7i-14, model number 82BH0006US, has a Thunderbolt 4.0 connector that allows it to output video to an external display. You may connect an HDMI display to this laptop by utilizing a Thunderbolt to HDMI adaptor, which is sold separately.
Does Lenovo Yoga 720 have HDMI input?
It does not have an HDMI connector, therefore I’m not sure how I’m supposed to link my Yoga 720-151 KB laptop to my television.
How do I get my Lenovo to recognize my second monitor?
Increase the number of display adapters in the category. Update the driver by selecting it from the context menu of the device. Select Automatically search for updated driver software from the drop-down menu. Following completion of these procedures, restart your computer if necessary to complete the installation and verify that your second monitor is operational. Figure 1:
How do I use HDMI on Lenovo all in one?
When you connect in the cable, the input signal is immediately switched to the output signal.
- Connect the A740 or A540 power connector to the computer. Installing an HDMI wire from your external monitor to the A740 or A540 is straightforward. Before connecting the HDMI connection, make sure that the external display is in Duplicate or Extend mode if it is a laptop computer.
How do I connect two monitors to my laptop with one HDMI port?
Use an adaptor, such as an HDMI to DVI converter, to connect the two displays. As long as you have two separate ports for your laptop and monitor, this will function well. To have two HDMI ports, a switch splitter, such as a Display splitter, need be used. This method works if your laptop only has one HDMI port, but you require two HDMI ports to complete your task.


Configurations available with 1 EPON or GPON ONU module; Configurations available with 2 or 4 HomePlug AV EOC Master modules; Configurations available. The module supports IEEE ah standards. It provide one SC/PC optical EPON uplink port and two 10//M auto-negotiable Ethernet RJ45 ports. eoc. By combining the technology of EPON, GPON and EOC with technology of HFC, it will greatly promote the development of application of two-way access of HFC.
|Published (Last):||3 April 2010|
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EoC-Ethernet over Coax + FTTH EPON/GPON solution
Cable television broadband access network based on cable access technology EOC consists of device in local side, terminal device in user side, cable, branch distributor and so on. EOC has various technical solutions, in which technology of Home Plug AV has highest stability, low two-way reconstruction cost and high rate in physical layer, so it is most widely applied and has become industry application standard in reality.
Home Plug is an enterprise alliance co-founded by tens of enterprises like Cisco, HP, Motorola and Intel with the aim of building local area network based on electric-power line. Data transmission in electric-power line, telephone wire, and cable-coaxial can be implemented in Home Plug AV. Comparing with electric-power line network, coaxial network of cable television has better channel quality.
Coaxial network resources can be sufficiently used and excavated by applying Home Plug AV technology in coaxial eov of cable television. Transmission range of PON access part can reach to 20Km, which can easily accomplish the coverage from head-end room to access point.
In EOC access part, epln system will not affect existing television channel signal as it adopts low frequency from 7.
EoC-Ethernet over Coax + FTTH EPON/GPON solution | FTTH & Triple Play Broadband equipment
There adopts fiber transmission technology in PON access part, so it will not be interfered by electrical signal. EPON access eox two-way bandwidth of 1.
OLT of local side Machine room is the core of PON system, provides uplink interfaces with high speed for information accessing like voice, data, and PON interfaces for passive optical distribution network. There is ODN network between OLT and ONU, which is passive optical distribution network consisting of optical splitter and optical fiber with the function of distributing and converging soc signals.
EOC products are mainly for the access from optical node to user in broadcast television network. This product is developed and designed by C-Data company independently with complete intellectual property, it integrates multiple technologies including passive optical network, Ethernet, eopn optical transmission, Internet security and network management, which can meet the needs for operators to provide high quality and reliable network services for users.
Main function module includes: There are many types according to the ec and applications of EOC products in local side, like corridor type, outdoor type, integration type, all-in-one machine. With rich variety of products, the needs of various application scenarios of broadcast television will be met.
Standard Ethernet fiber optical transceiver module, can connect the fiber optical transceiver products of our company or third party, provides connection for data services Related Products: Transmission Distance Transmission range of PON access part can reach to 20Km, fpon can easily accomplish the coverage from head-end room to access point. Anti-Interference Capability There adopts fiber transmission technology in PON access part, so it will not be interfered by electrical signal.
Based on HomePlug AV and IEEE standard, co-uses with Eof terminal device, builds layer 2 Ethernet data transmission channel in coaxial network of cable television, provides broadband access service based on coaxial network for users.
Standard Ethernet fiber optical transceiver module, can connect the fiber optical transceiver products of our company or third party, provides connection for data services.


2MP 1080P HD USB camera with 1/2.7" AR0230 Sensor
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Support UVC protocol, no driver, plug and play.
Support USB2.0 OTG protocol, OTG access devices.
Support linux, Android and other embedded systems.
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Scan from your mobile devices over a direct Wi-Fi connection without complicated setup or internet requires. Wireless scanning makes scanning easy, convenient, and truly mobile.
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It generates real-time motion imaging during scanning that enables to watch the scan results at the same time
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iScanAir Go offers two modes to completely satisfy the scanning needs via wireless or non-wireless operation
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iScanAir Go is nicely shaped for easy one hand holding that allows free movement in all directions. Ideal to scan books, documents, news-papers, boxes, decorative patterns, notes and much more.
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Werbos P J. Approximate dynamic programming for real-time control and neural modeling. In: Handbook of Intelligent Control: Neural, Fuzzy, and Adaptive Approaches. New York: Van Nostrand Reinhold, 1992. 15: 493–525
Vamvoudakis K G, Lewis F L. Online actor-critic algorithm to solve the continuous-time infinite horizon optimal control problem. Automatica, 2010, 46: 878–888
Lewis F L, Vrabie D, Vamvoudakis K G. Reinforcement learning and feedback control: using natural decision methods to design optimal adaptive controllers. IEEE Control Syst Mag, 2012, 32: 76–105
Zhang H, Cui L, Luo Y. Near-optimal control for nonzero-sum differential games of continuous-time nonlinear systems using single-network ADP. IEEE Trans Cyber, 2013, 43: 206–216
Mu C, Sun C, Song A, et al. Iterative GDHPbased approximate optimal tracking control for a class of discrete-time nonlinear systems. Neurocomputing, 2016, 214: 775–784
Wang D, Liu D, Zhang Q, et al. Data-based adaptive critic designs for nonlinear robust optimal control with uncertain dynamics. IEEE Trans Syst Man Cyber Syst, 2016, 46: 1544–1555
Gao W, Jiang Y, Jiang Z P, et al. Output-feedback adaptive optimal control of interconnected systems based on robust adaptive dynamic programming. Automatica, 2016, 72: 37–45
Sahoo A, Xu H, Jagannathan S. Approximate optimal control of affine nonlinear continuous-time systems using event-sampled neurodynamic programming. IEEE Trans Neural Netw Learn Syst, 2017, 28: 639–652
Narayanan V, Jagannathan S. Distributed adaptive optimal regulation of uncertain large-scale interconnected systems using hybrid Q-learning approach. IET Control Theory Appl, 2016, 10: 1448–1457
Fu Q, Gu P P, Wu J R. Iterative learning control for one-dimensional fourth order distributed parameter systems. Sci China Inf Sci, 2017, 60: 012204
This work was supported by National Natural Science Foundation of China (Grant Nos. 61233001, 61273140, 61304018, 61304086, 61533017, U1501251), Beijing Natural Science Foundation (Grant No. 4162065), Tianjin Natural Science Foundation (Grant No. 14JCQNJC05400), Early Career Development Award of SKLMCCS, and Research Fund of Tianjin Key Laboratory of Process Measurement and Control (Grant No. TKLPMC-201612).
The authors declare that they have no conflict of interest.
About this article
Cite this article
Wang, D., Mu, C. Developing nonlinear adaptive optimal regulators through an improved neural learning mechanism. Sci. China Inf. Sci. 60, 058201 (2017). https://doi.org/10.1007/s11432-016-9022-1


The next era of laboratory automation is no longer about sample movers or liquid handlers. With big data being the central focus, several new trends have emerged in this space, making laboratory automation better, more powerful, and more accessible. By Anita Ramanathan.
Automation goals once revolved around ‘getting more done’. Now, the goal is to build a ‘smart laboratory’ where a central platform connects and controls multiple instruments. Meanwhile, an information management system captures and stores all the data generated, making it easier for machine learning algorithms to identify patterns and inform future decisions. Worried this might be a little too much to pull off? Enter cloud-based R&D laboratories that have everything set up and ready to go.
From AI-driven drug discovery to robot scientists, here are some of the latest trends in laboratory automation.
Workflows with end-to-end automation
Automation has visibly evolved from simply performing repetitive tasks to now intuitively fulfilling the entire workflow, from start to finish, better known as end-to-end automation. This is where different automation systems within a facility connect and communicate with each other to execute workflows autonomously. For example, in cell-based microscopy, the liquid handler, sample mover, incubator, and microscope are all centrally connected. When the sequence is triggered, the workflow initiates, advancing from one step to the next, all while capturing the data and sending it to a cloud-based server.
A specially designed software is used to connect all these systems, plan workflow sequences, and monitor progress remotely, sometimes in real-time. Such an integrated ecosystem of automation can significantly eliminate the white space between individual workflows, resulting in a smoother, faster operation for the entire laboratory.
“Our goal in drug discovery is to use automation as a tool to find drugs faster, reduce costs, and improve accuracy,” notes Dr Cathy Tralau-Stewart, Chief Scientific Officer at C4X Discovery, a company that combines drug discovery expertise and cutting-edge technologies. “We can now employ automation in almost every aspect of drug discovery – from finding and validating targets to running clinical trials. We need to leverage any tool – automation included – to make our processes more efficient, and hopefully, reduce attrition rates.”
To experience immediate efficiency gains from end-to-end automation, without being weighed down by the technical minutiae of algorithms, it helps to collaborate with vendors specialising in automation software and hardware to customise and build out these sequences. The deployment of these advanced automation projects can range from a few months to almost a year based on the sophistication of the workflow.
One such success story of end-to-end automation accelerating the drug discovery pipeline comes from the AstraZeneca iLab in Gothenburg, Sweden, where compound synthesis runs on automation. “What was once a manual, multi-step process in medicinal chemistry is now fully automated, from start to finish”, says Dr Michael Kossenjans, Head of iLab, AstraZeneca. “We set up, perform, and monitor the chemical reactions. Once complete, we can then isolate, purify, and quantify the crude product – all from a single platform.”
The iLab team has successfully built a centrally connected automation system that can manage different instruments involved in the compound synthesis workflow, i.e, supplying the precursor chemicals, performing the analytical chemistry, and preparing the stock solution for screening. Using carefully crafted workflow sequences, small molecule compounds are now synthesised and purified autonomously.
Centralising data and adopting good data practices
Automation generates massive amounts of data. This can be good news or bad news – it all depends on the data practices enforced within the laboratory. Given the large volume of data being produced, laboratories need to have a digital infrastructure in place to manage it.
Data gathered from automated workflows will need to be appropriately captured, annotated, and stored. Digital tools can be typically used to centralise and manage all the data from instruments, samples, inventory as well as end-to-end workflows. Instruments with their own vendor software platform connect to the central data repository through an application programming interface (API).
Modern data management solutions specifically designed to support automation in laboratories are already equipped with all these necessary features. It is, however, important to standardise experimental processes and data capture practices across the company. This means, experiments are kept consistent, and for each experiment, the user records the same set of data points every single time. “A big part of my role as the data director is to ensure that datasets are gathered properly,” says Dr Yohann Potier, Director of Data Platform at Tessera Therapeutics, a company pioneering in a novel genome engineering technology. “Our automation, computational and scientific teams work in close collaboration to uphold good data practices.”
“There is immense value in data – that is where the intellectual property is,” adds Dr Potier. “In the era of automation, I would say a company’s data is now considered to be its biggest asset.” Cloud-based information management systems can be used to centralise data and make it accessible remotely in real-time, eliminating data silos between teams or departments. This stored data can then be retrieved in the future to power machine learning algorithms. But there’s one caveat – the available data needs to be ‘clean’.
“As laboratories build their automation systems with the goal of using AI in the future, having a clear strategy for gathering and storing this data is an important step,” notes Anca Ciobanu, Theme Lead at Pistoia Alliance, a not-for-profit membership organisation aimed at bringing R&D leaders together for pre-competitive collaborations. “Changing data practices every so often or swapping platforms without a purpose decentralises the laboratory’s data, making it very challenging to make use of it later on, ”continues Ciobanu. “Implementing AI is only possible with centralised, good quality data.”
Leveraging AI in small and big ways
A 2021 report1revealed that AI will have the most impact on the pharmaceutical industry in the coming years, attracting almost 100 collaborations between pharma companies and AI vendors in recent times. Although AI is already being successfully used in tech industries and for image and speech recognition, it is now beginning to make strides in drug discovery as well.
In laboratories with automated workflows, the data generated from a series of experiments can be used to train AI systems to learn the ‘rules’ of the experiment and infer new knowledge accordingly. AI is essentially the ability of a computer to mimic human cognitive functions, such as learning and troubleshooting. Machine learning, on the other hand, is a subset of AI. It uses data to learn and improve without any intervention, imparting intelligence to the computer.
In a scientific setting, AI can be used to run simple tasks or to perform complex multi-step workflows. At the AstraZeneca iLab, AI is used in small and big ways. “We use an AI-based platform that provides us with suggestions on how to synthesise compounds”, says Dr Kossenjans. “In the past, to synthesise a molecule, a chemist would have to scribble down all the different steps to be performed. Now, we have algorithms where we simply input the desired molecule, and it shows us the steps required to synthesise it, along with protocols and literature references.”
Dr Kossenjans continues: “Running a fully autonomous workflow with no human input wouldn’t be possible without AI because there needs to be a programme that can make decisions in our absence. Our automated workflows have an ‘if this happens, then do that’ feature. For example, if the pressure in the reactor vial gets too high, then stop and cool immediately. That’s AI at work.”
The team is now building a more advanced AI model to make decisions on the experimental process itself, beyond the instrument. For example, if particular outcome wasn’t achieved, the AI will analyse what went wrong and automatically choose how to modulate the temperatures or solvent concentrations, and then repeat the experiment. The fundamental goal of AI in drug discovery is to progress experiments in a self-determining, independent manner to reliably achieve the desired output.
The arrival of robot scientists
What if your lab partner happened to be a robot? That’s what Dr Ross King, Professor of Machine Intelligence at Chalmers University of Technology, studies and develops.
Dr King’s team built the world’s first robot scientist, named Adam, that successfully made a novel scientific discovery in yeast genomics without any human intervention. A robot scientist is essentially a computation system that is capable of generating its own hypothesis, performing experiments, analysing data, and repeating the entire cycle. Its brain is a collection of computers; its body, a set of laboratory robotic arms connected to incubators, liquid handlers, and other relevant instruments.
And it’s the kind of lab partner that doesn’t stop until it finds an answer.
“We equip the robot scientist with background knowledge. With that, it has an automated way of formulating hypotheses using machine learning”, explains Dr King. “It can then select different experiments to test each hypothesis. We optimised it for time and speed – so it would design experiments that are as cheap as possible and get to the answer as fast as possible. The robotic arms then carry out the experiment, providing results that the robot scientist can analyse. This cycle then continues until there is only one final theory that is consistent with the background knowledge provided.”
After Adam came Eve, the second robot scientist from Dr King’s laboratory that can automate early-stage drug design. Eve can autonomously perform library screening, confirm hits, and generate leads. Currently, the next-generation robot scientist being developed in his laboratory is called Genesis, equipped with AI capabilities to design, plan, and execute thousands of parallel experiments in complex biological models.
Simultaneously, Dr King is also working on the ultimate challenge – building an AI-driven robot scientist that can autonomously design and make Nobel Prize-quality scientific discoveries by 2050.
While the idea of robot scientists taking over experiments in drug discovery may make some uncomfortable, when seen through the lens of shrinking the drug discovery timeline, there’s no tool better than machines, according to Dr King: “Machines are much faster than humans at deciding what compound to test next. They can analyse copious amounts of data from previous experiments and comb through millions of scientific publications. And they can do so more logically, more reliably, and better than humans ever can. I believe robot scientists have the potential to significantly improve productivity and efficiencies in the drug discovery process, and ultimately save time and costs.”
Can AI and robots ever replace scientists in drug discovery?
Over the years, laboratory automation has progressed in its capabilities and sophistication. Now, with AI-enabled troubleshooting and robotics, experiments can be autonomously performed with minimal human intervention.
Understandably, some scientists worry if these machines might be smart enough to replace humans. While it’s certain that the role of a scientist within an R&D laboratory is bound to change in the near future, machines cannot replace scientific thinking, experts concur.
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“This concern stems from our reluctance to embrace change. Organisations that are investing in automation need to engage in open dialogue with their scientific team. It needs to be clearly communicated that automation will make it possible for them to work on more valuable and creative tasks that ultimately accelerate the drug discovery process.
Also, many scientists trained in academic settings may not have had the opportunity to work alongside automation systems. Therefore, offering training opportunities to build their knowledge around AI can alleviate some of these concerns. Over time, with increased awareness, scientists will become more receptive to their changing roles.” – Anca Ciobanu, Theme Lead, Pistoia Alliance.
“Humans and machines are better together than they are alone. AI systems can already perform the complete loop of scientific research, including hypothesis development and data analyses. My contribution to science is the world’s first robot scientist that autonomously made a novel scientific discovery. Since then, my team has built more advanced robot scientists.
AI systems have superhuman capabilities to remember, learn, and extract useful information from enormous datasets. I believe we need to explore this power of AI, especially if it can get us better, faster results in drug discovery.
On the other hand, humans have a much better understanding of the overall goal of a project. Robots don’t get the ‘big picture’ as they can only solve a specific problem based on the knowledge we provide.” – Dr Ross King, Professor of Machine Intelligence, Chalmers University of Technology.
“My position on this is very much inspired by chess. A computer can be programmed to become a great chess player. However, if we teamed this computer up with a grandmaster, we now have an unbeatable combination. Scientific work can be significantly enhanced by combining the core strengths of AI and the human mind.
We became scientists because we were curious about the world around us… about how things work. What if we applied that natural curiosity to not only explore what we’re studying, but also how we’re studying it? Having that openness and being willing to learn about AI and how to leverage it for better and faster research will be key.” – Dr Martin-Immanuel Bittner, CEO and Co-Founder, Arctoris.
“I don’t think robots can replace us, but they can definitely transform what we do and how we do it. This is an industry that cannot – and should not – sit still. Being in drug discovery requires embracing innovation. We need to be willing to learn new and different ways of doing things.
By leveraging the speed of robotics, we can actually do better science – produce higher quality data, screen fewer compounds, and bring drugs to market faster. As for the fear of being taken over by robots… If scientists ultimately control and program the robots, then there’s actually nothing to worry about, right? Scientists can now focus on the science rather than routine tasks and can gain valuable insights from AI and machine learning.” – Dr Cathy Tralau-Stewart, Chief Scientific Officer, C4X Discovery.
“Machines can give us more freedom to creatively think about a scientific problem. Let’s take an example from the field of imaging. Histopathologists spend years in training learning about how cells look under a microscope. On the job, they used to spend hours every day examining a single image and drawing contours around cells. Now, a machine can do this task in seconds. But histopathologists haven’t lost their jobs. They now bring other strengths, such as adding new targets to the imaging protocols and reviewing data.
In much the same way, when AI and machine learning take over some of the tasks, scientists can spend more time designing new experiments or scaling up existing workflows. – Dr Yohann Potier, Director, Data Platform, Tessera Therapeutics.
Remote R&D labs and strategic partnerships
For an individual laboratory, automating a single task can be rather straightforward but building an in-house robotic system that can accelerate the R&D process isn’t trivial. This is where outsourcing to or partnering with R&D laboratories with niche expertise and ready-to-go automation systems can come in handy.
Cloud-based R&D laboratories are now emerging both in service-based start-ups, such as Emerald Cloud Lab and Strateos that provide remote-controlled R&D services to research groups, as well as inside global pharmaceutical companies to streamline internal projects across different teams. Using a secure portal, a task triggered from any site in the world can now be completed at a dedicated R&D laboratory located remotely. “When we build our fully automated, cloud-powered R&D laboratories at AstraZeneca in a year or two, we want our scientists from around the world – in US, UK, China, Sweden and beyond – to be able to use them”, shares Dr Kossenjans. “No matter where the laboratory is physically located, experiments can be started from a user’s desktop.”
Establishing strategic partnerships with drug discovery companies that have in-house expertise in data science and automation can also help accelerate the R&D pipeline. “We automate every step of the drug discovery process – target validation, hit ID, hit-to-lead, and lead optimisation”, says Dr Martin-Immanuel Bittner, Co-Founder and CEO of Arctoris, a tech-enabled drug discovery company that leverages robotics, data science, and machine learning to progress a pipeline of programmes in oncology and neurology.
This new category of drug discovery companies, such as Arctoris, is entirely powered by data. “There are literally hundreds of AI companies out there, but only a handful that combines robotics, data science, and AI,” says Dr Bittner, who is a clinician-scientist by background. “We developed a fully automated laboratory architecture that allows us to generate structured, reproducible, high-quality data that is machine-learning ready by design. That means, we can power our AI’s decision-making process with this superior quality data, enriched with metadata and contextual information. We strongly believe that the key to successful drug discovery lies in having better data to make better decisions – and ultimately benefit patients worldwide.”
Here’s how strategic partnerships work with data-powered R&D companies: Once you’ve established a partnership agreement, and both scientific teams have agreed on the milestones they would like to achieve together, the experiments are built using the vast library of automated protocols that the company, such as Arctoris, has already developed and optimised. When the project begins, experiments run in a robotic wet laboratory, generating data 24×7.
Leveraging a fully automated R&D workflow has the potential to produce more than 100x the number of data points per experiment compared to industry standards, according to Dr Bittner. Plus, the data is automatically captured, annotated, quality-controlled, visualised and analysed. This allows the iterative ‘design-make-test-analyse’ cycle in R&D to be accelerated several-fold.
Collaborating to serve a unified cause
As the pharma industry navigates the unpaved path towards AI-driven drug discovery, sharing knowledge and collaborating with peers will be necessary. At the moment, each company, working independently, tackles AI-related problems on its own, unaware of the fact that dozens of others might have a similar challenge. But what if we were to start exchanging ideas and share our best practices with industry peers? Working together – and setting standards along the way – might just help us all get to our goals faster. After all, every company in the industry strives to achieve the same cause – bringing better drugs to the market, faster.
“We learn as much from our missteps as from our successes,” says Ciobanu, who moderates in-depth discussions on topics such as automation, AI, and machine learning for professionals across the industry. “Presenting use cases at conferences and outlining AI strategies that worked, along with those that didn’t, can help companies learn from each other. That’s why at Pistoia Alliance we encourage open discussions between small and large pharma companies to facilitate knowledge sharing, brainstorm ideas, and provide access to information otherwise contained within companies.”
“We’re also seeing better integration between automation vendors and software providers,” notes Dr Potier. “They’re now working together to provide APIs and open databases so lab-generated data can be easily converted to reports. This type of integration was nearly impossible a few years ago.”
On another note, a critical issue resulting from automation that requires our immediate attention is the plastic waste generated from single-use consumables. “We perform thousands of experiments on our automated platforms, often in parallel, producing excessive amounts of plastic waste around the world, each day”, says Dr Kossenjans. “This is something that warrants our attention right now… while we build our automation systems. Because it doesn’t make sense to advance one domain of science while creating a new problem for another.”
Drug Discovery World e-book – innovating in the lab
About the author
Anita Ramanathan is a science writer and award-winning speaker based in Bristol, UK. In her capacity as a science writer/editor at several digital publications, including NIH Research Matters, she has crafted dozens of stories buried under numbers and scientific findings. A storyteller at heart, Anita also delivers science communication workshops.


Adversarial attacks against machine learning models are a rather hefty obstacle to our increasing reliance on these models. Due to this, provably robust (certified) machine learning models are a major topic of interest. Lipschitz continuous models present a promising approach to solving this problem. By leveraging the expressive power of a variant of neural networks which maintain low Lipschitz constants, we prove that three layer neural networks using the FullSort activation function are Universal Lipschitz function Approximators (ULAs). This both explains experimental results and paves the way for the creation of better certified models going forward. We conclude by presenting experimental results that suggest that ULAs are a not just a novelty, but a competitive approach to providing certified classifiers, using these results to motivate several potential topics of further research.


02-23-2012, 12:43 PM
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According to Finnish Energy, more than one-third of the electricity produced in Finland in 2022 came from nuclear energy and less than 20% from hydropower. The shares of biomass and wind energy were slightly smaller than that of hydropower. The share of nuclear energy will increase significantly once the Olkiluoto 3 nuclear power plant unit starts regular electricity production. The share of wind energy increases at a faster rate. Wind energy could cover as much as 50% of Finland's electricity consumption in 2030, according to Anni Mikkonen, Executive Manager of the Finnish Wind Power Association. The share of wind energy could rise to 70%. Finland's electricity transmission system operator Fingrid estimates that wind energy will overtake nuclear energy in 2026 or 2027.


For the development of innovative technologies and products, the customer conducts its own research and development (R&D). Experts from the fields of measurement technology, machine learning (ML), frontend and backend software development and user experience form an interdisciplinary team.
Among other things, the customer developed a product with the aim of an automated, location- and device-independent online test procedure for the individual adaptation of medical products. The central aspect of the project is the digitization of the measurement process, which is traditionally carried out on site with the help of specialized equipment and trained personnel. PROTOS Technologie supported the customer in achieving this goal by implementing a modern cloud infrastructure to improve and accelerate the development process.
Machine Learning Operations (MLOps)
When changing from the experimental development phase to production maturity, it became clear to the customer that, above all the Working with Machine Learning Operations (MLOps) brings great benefits. The central prerequisite for the successful implementation of the project was a robust, cost-effective and secure infrastructure which can be continuously tailored and optimized for new machine learning tasks. This means that machine learning engineers can be relieved of the often most time-consuming tasks such as data preparation and model provision and use their capacities for development progress.
In order to integrate new AWS cloud-based MLOps functions into the backend, there had to be close coordination with the respective development teams. The frontend developers were provided with endpoints for uploading data and using the machine learning models with the right interfaces. In cooperation with machine learning engineers and data scientists, a data environment hosted in AWS and a training environment for ML was set up.
Also the Development and maintenance of a scalable CI/CD pipeline, to ensure versioning, verifiability and testing was part of the requirements and interlocks classic DevOps with ML-specific requirements to MLOps.
AWS Machine Learning Pipeline:
PROTOS Technologie supported the customer in the implementation of MLOps so that the necessary infrastructure resources and processes could be made available. Automation has improved, accelerated and secured the development process.
Probably the biggest challenge in machine learning projects is often the enormous amount of time that is required to process data acquisition, data preparation and model training. The biggest advantage of MLOps is the facilitation by automating processes and relieving the ML experts to optimize a machine learning project.
In addition to collection and storage, the large amounts of data required also require prior preparation. The provision on modern cloud infrastructure, as well as the optimization and automation of these factors, with the help of PROTOS’ cloud expertise, made an essential contribution to improving the entire machine learning process.
Implementation in the AWS Cloud:
In the AWS Cloud, a Data Pipeline with AWS Lambda, Amazon S3 and implemented AWS KMS, which encrypts the data, prepares it and supports ongoing data cleaning (data cleaning) and categorization (data labeling).
With the data and the computing capacity provided by AWS, the machine learning model training could be transferred to the AWS cloud in a containerized form. The advantage was that the model training can be run on the scalable and optimized CPUs and GPUs of the cloud, regardless of location and user. In addition, the hosting of the trained models in production could be realized in a lightweight, cost-effective and highly available and scalable manner via AWS Lambda serverless. The possibility of a containerized runtime in AWS Lambda offers modern API-first approaches even for the deployment of complex machine learning models.
To enable interaction with the data pipeline and the ML model results, a secure AWS API Gateway endpoint was made available to mobile and frontend developers.
The highest security standards and intensive testing (unit tests / integration tests) were the basis of the implemented CI/CD process, which automates the deployment and testing of the infrastructure operated on AWS.
All resources were obtained using AWS Cloud Development Kit (CDK) if Infrastructure-as-Code provided. This meant that the complete infrastructure for operating an MLOps-optimized machine learning project could be provisioned and understandably adjusted with one click, and could continue to be operated by the customer himself.