Investigators are attracted by the complexity and significance of preventive maintenance problem,and there are hundreds of maintenance models and methods to solve the maintenance problems of companies and army,going w...Investigators are attracted by the complexity and significance of preventive maintenance problem,and there are hundreds of maintenance models and methods to solve the maintenance problems of companies and army,going with a lot of investigative harvests. However,one-component system or series system is focused by most of the literature.The problem of preventive maintenance（PM） on cold standby repairable system does not attach importance despite the fact that the cold standby repairable system is ubiquitous in engineering systems.In this paper,an optimal replacement model for gamma deteriorating system is studied.This methodology presented uses a gamma distribution to model the material degradation,and the impact of imperfect maintenance actions on system reliability is investigated.After an imperfect maintenance action,the state of a degrading system is assumed as a random variable and the maintenance time follows a geometric process.A maintenance policy（N）is applied by which the system will be repaired whenever it experiences the Nth PM,and an optimal policy（N~＊） could be determined numerically or analytically for minimizing the long-run average cost per unit time.A numerical example about how to confirm the optimal maintenance time by the inspecting information of liquid coupling device is given to demonstrate the use of this policy.This paper presents a condition-based replacement policy for cold standby repairable system under continuous monitoring.Its contribution embody in two aspects,relaxing the restrictions of hypothesis and investigating the condition-based maintenance policy of the cold standby repairable system which is ignored by others.展开更多
This paper explores and proposes a design solution of an integrated skip cycle mode （SCM） control circuit with a simple structure. The design is simulated and implemented with XD10H-1.0μm modular DIMOS 650 V proces...This paper explores and proposes a design solution of an integrated skip cycle mode （SCM） control circuit with a simple structure. The design is simulated and implemented with XD10H-1.0μm modular DIMOS 650 V process. In order to meet the requirement of a wide temperature range and high yields of products, the schematic extracted from the layout is simulated with five process corners at 27℃ and 90℃. Simulation results demonstrate that the proposed integrated circuit is immune to noise and achieves skipping cycle control when switching mode power supply （SMPS） works with low load or without load.展开更多
In this paper, we study availability and profit optimization of a series-parallel system consisting of three subsystems A, B and C in which A and B are cold standby. Subsystem A consists of linear consecutive k-out-of...In this paper, we study availability and profit optimization of a series-parallel system consisting of three subsystems A, B and C in which A and B are cold standby. Subsystem A consists of linear consecutive k-out-of-n units while subsystems B and C consist of a single unit each. The system works if any of A or B and C work. The objective of this study is to maximize the steady-state availability and profit. To solve the optimization problem, different numbers of units for n = 2, 3, 4, 5 in subsystem A are considered. Explicit expressions for busy period of repairmen, steady-state availability and profit function are derived using linear first order differential equations. Several cases are analyzed graphically for n = 2, 3, 4, 5 to investigate the effects of various system parameters on availability and profit. The paper also presents graphical comparison for specific values of system parameters and finds that the optimal system configuration is when n = 5.展开更多
Silicon-on-insulator (SOI) CMOS technology is a very attractive option for implementing digital integrated circuits for low power applications. This paper presents migration of standby subthreshold leakage control tec...Silicon-on-insulator (SOI) CMOS technology is a very attractive option for implementing digital integrated circuits for low power applications. This paper presents migration of standby subthreshold leakage control technique from a bulk CMOS to SOI CMOS technology. An improved SOI CMOS technology based circuit technique for effective reduction of standby subthreshold leakage power dissipation is proposed in this paper. The proposed technique is validated through design and simulation of a one-bit full adder circuit at a temperature of 27℃, supply voltage, VDD of 0.90 V in 120 nm SOI CMOS technology. Existing standby subthreshold leakage control techniques in CMOS bulk technology are compared with the proposed technique in SOI CMOS technology. Both the proposed and existing techniques are also implemented in SOI CMOS technology and compared. Reduction in standby subthreshold leakage power dissipation by reduction factors of 54x and 45x foraone-bit full adder circuit was achieved using our proposed SOI CMOS technology based circuit technique in comparison with existing techniques such as MTCMOS technique and SCCMOS technique respectively in CMOS bulk technology. Dynamic power dissipation was also reduced significantly by using this proposed SOI CMOS technology based circuit technique. Standby subthreshold leakage power dissipation and dynamic power dissipation were also reduced significantly using the proposed circuit technique in comparison with other existing techniques, when all circuit techniques were implemented in SOI CMOS technology. All simulations were performed using Microwindver 3.1 EDA tool.展开更多
The central nervous system （CNS） contains the two most important organs, the brain and spinal cord, for the orchestration of the mental and physical activities of life. Because of its importance, the human body has ...The central nervous system （CNS） contains the two most important organs, the brain and spinal cord, for the orchestration of the mental and physical activities of life. Because of its importance, the human body has evolved barrier systems to protect CNS tissue from the external environment. This barrier is a membrane composed of tightly apposed cells and is selectively permeable to specific molecules by way of membrane transporters.展开更多
This paper outlines the barriers and potential benefits of using standby diesel generators in mitigating the peak demands for commercial and industrial customers. The feasibility of utilizing the standby diesel genera...This paper outlines the barriers and potential benefits of using standby diesel generators in mitigating the peak demands for commercial and industrial customers. The feasibility of utilizing the standby diesel generators to reduce the electricity bills for customers is carried out by using the hybrid optimization model for electric renewable(HOMER)software. The size of the standby diesel generator and its operational duration are determined based on the lowest cost of electricity obtained from the evaluations. The economic assessments demonstrate that there is potential to reduce the electricity bills for commercial and industrial customers under the existing fuel price and tariffs. The commercial customers under the tariff C2 have the highest potential to save their electricity bills with the use of standby diesel generators for peak reduction. This study demonstrates the potential of the standby diesel generators in peak reduction.展开更多
The protection device with low price and high maintenance cost can be used for a long time. In order to improve availability of protection system,a method of increasing redundancy and periodic replacement is proposed....The protection device with low price and high maintenance cost can be used for a long time. In order to improve availability of protection system,a method of increasing redundancy and periodic replacement is proposed. Firstly,the equivalent model of cumulative failure probability was established. Then,the wasting time of the spare part is converted into the working time of the using part.Considering the optimization objective,under the strategy of block replacement, the availability model in infinite period with the maximum availability and the cost model in finite period with the minimum cost are established separately. In this case,we seek out the optimum replacement interval and verify the applicability and validity of the model through contrast and analysis. Finally,the paper gives a brief discussion of future research area about warm standby system maintenance.展开更多
In this paper, four new hybrid digital circuit design techniques, namely, hybrid multi-threshold CMOS complete stack technique, hybrid multi-threshold CMOS partial stack technique, hybrid super cutoff complete stack t...In this paper, four new hybrid digital circuit design techniques, namely, hybrid multi-threshold CMOS complete stack technique, hybrid multi-threshold CMOS partial stack technique, hybrid super cutoff complete stack technique and hybrid super cutoff partial stack technique, have been proposed to reduce the subthreshold leakage power dissipation in standby modes. Techniques available in literature are compared with our proposed hybrid circuit design techniques. Performance parameters such as subthreshold leakage power dissipation in active and standby modes, dynamic power dissipation and propagation delay, are compared using existing and proposed hybrid techniques for a two input AND gate. Reduction of subthreshold leakage power dissipation in standby mode is given more importance, in comparison with the other circuit design performance parameters. It is found that there is reduction in subthreshold leakage power dissipation in standby and active modes by 3.5× and 1.15× respectively using the proposed hybrid super cutoff complete stack technique as compared to the existing multi-threshold CMOS (MTCMOS) technique. Also a saving of 2.50× and 1.04× in subthreshold leakage power dissipation in standby and active modes respectively were observed using hybrid super cutoff complete stack technique as compared to the existing super cutoff CMOS (SCCMOS) technique. The proposed hybrid super cutoff stack technique proved to perform better in terms of subthreshold leakage power dissipation in standby mode in comparison with other techniques. Simulation results using Microwind EDA tool in 65 nm CMOS technology is provided in this paper.展开更多
This paper we proposed advanced burst mode control technique to reduce the standby power consumption of the switch mode power supply (SMPS). To reduce the standby power consumption, most of the converter use burst mod...This paper we proposed advanced burst mode control technique to reduce the standby power consumption of the switch mode power supply (SMPS). To reduce the standby power consumption, most of the converter use burst mode or skip mode control technique. However Conventional standby mode control techniques have some problems such as audible noise and poor regulation. In proposed techniques, basically, the burst mode control technique is employed to reduce the fundamental switching frequency while limiting the peak drain current. But, in proposed technique, to improve the regulation characteristic, burst period of the proposed technique is shorter than that of the conventional burst mode technique. And also, to reduce the switching loss increase due to the short burst period, burst switching signal of the proposed technique is partially skipped. By using proposed advanced burst mode control technique, calculated standby power is 0.695W while standby power of the conventional burst mode control is 1.014W.展开更多
Willing to work in reliability theory in a general set up, under stochastically dependence conditions, we intend to characterize a not identically spare standby redundancy operation through compensator transform under...Willing to work in reliability theory in a general set up, under stochastically dependence conditions, we intend to characterize a not identically spare standby redundancy operation through compensator transform under a complete information level, the physic approach, that is, observing its component lifetime. We intend to optimize system reliability under standby redundancy allocation of its components, particularly, under minimal standby redundancy. To get results, we will use a coherent system representation through a signature point process.展开更多
This paper investigates a warm standby repairable retrial system with two types of components and a single reparman,where type 1 components have priority over type 2 in use.Failure and repair times for each type of co...This paper investigates a warm standby repairable retrial system with two types of components and a single reparman,where type 1 components have priority over type 2 in use.Failure and repair times for each type of component are assumed to be exponential distributions.The retrial feature is considered and the retrial time of each failed component is exponentially distributed.By using Markov process theory and matrix analytic method,the system steady-state probabil-ities are derived,and the system steady-state availability and some steady-state performance indices are obtained.Using the Bayesian approach,the system parameters can be estimated.The cost-benefit ratio function of the system is constructed based on the failed components and repairman's states.Numerical experiments are given to evaluate the effect of each parameter on the system steady-state availability and optimize the system cost-benefit ratio with repair rate as a decision variable.展开更多
SRAM standby leakage reduction plays a pivotal role in minimizing the power consumption of ap- plication processors. Generally, four kinds of techniques are often utilized for SRAM standby leakage reduction： Vdd lowe...SRAM standby leakage reduction plays a pivotal role in minimizing the power consumption of ap- plication processors. Generally, four kinds of techniques are often utilized for SRAM standby leakage reduction： Vdd lowering （VDDL）, Vss rising （VSSR）, BL floating （BLF） and reversing body bias （RBB）. In this paper, we comprehensively analyze and compare the reduction effects of these techniques on different kinds of leakage. It is disclosed that the performance of these techniques depends on the leakage composition of the SRAM cell and temperature. This has been verified on a 65 nm SRAM test macro.展开更多
基金supported by National Natural Science Foundation of China(Grant No.60904002)
文摘Investigators are attracted by the complexity and significance of preventive maintenance problem,and there are hundreds of maintenance models and methods to solve the maintenance problems of companies and army,going with a lot of investigative harvests. However,one-component system or series system is focused by most of the literature.The problem of preventive maintenance（PM） on cold standby repairable system does not attach importance despite the fact that the cold standby repairable system is ubiquitous in engineering systems.In this paper,an optimal replacement model for gamma deteriorating system is studied.This methodology presented uses a gamma distribution to model the material degradation,and the impact of imperfect maintenance actions on system reliability is investigated.After an imperfect maintenance action,the state of a degrading system is assumed as a random variable and the maintenance time follows a geometric process.A maintenance policy（N）is applied by which the system will be repaired whenever it experiences the Nth PM,and an optimal policy（N~＊） could be determined numerically or analytically for minimizing the long-run average cost per unit time.A numerical example about how to confirm the optimal maintenance time by the inspecting information of liquid coupling device is given to demonstrate the use of this policy.This paper presents a condition-based replacement policy for cold standby repairable system under continuous monitoring.Its contribution embody in two aspects,relaxing the restrictions of hypothesis and investigating the condition-based maintenance policy of the cold standby repairable system which is ignored by others.
文摘This paper explores and proposes a design solution of an integrated skip cycle mode （SCM） control circuit with a simple structure. The design is simulated and implemented with XD10H-1.0μm modular DIMOS 650 V process. In order to meet the requirement of a wide temperature range and high yields of products, the schematic extracted from the layout is simulated with five process corners at 27℃ and 90℃. Simulation results demonstrate that the proposed integrated circuit is immune to noise and achieves skipping cycle control when switching mode power supply （SMPS） works with low load or without load.
文摘In this paper, we study availability and profit optimization of a series-parallel system consisting of three subsystems A, B and C in which A and B are cold standby. Subsystem A consists of linear consecutive k-out-of-n units while subsystems B and C consist of a single unit each. The system works if any of A or B and C work. The objective of this study is to maximize the steady-state availability and profit. To solve the optimization problem, different numbers of units for n = 2, 3, 4, 5 in subsystem A are considered. Explicit expressions for busy period of repairmen, steady-state availability and profit function are derived using linear first order differential equations. Several cases are analyzed graphically for n = 2, 3, 4, 5 to investigate the effects of various system parameters on availability and profit. The paper also presents graphical comparison for specific values of system parameters and finds that the optimal system configuration is when n = 5.
文摘Silicon-on-insulator (SOI) CMOS technology is a very attractive option for implementing digital integrated circuits for low power applications. This paper presents migration of standby subthreshold leakage control technique from a bulk CMOS to SOI CMOS technology. An improved SOI CMOS technology based circuit technique for effective reduction of standby subthreshold leakage power dissipation is proposed in this paper. The proposed technique is validated through design and simulation of a one-bit full adder circuit at a temperature of 27℃, supply voltage, VDD of 0.90 V in 120 nm SOI CMOS technology. Existing standby subthreshold leakage control techniques in CMOS bulk technology are compared with the proposed technique in SOI CMOS technology. Both the proposed and existing techniques are also implemented in SOI CMOS technology and compared. Reduction in standby subthreshold leakage power dissipation by reduction factors of 54x and 45x foraone-bit full adder circuit was achieved using our proposed SOI CMOS technology based circuit technique in comparison with existing techniques such as MTCMOS technique and SCCMOS technique respectively in CMOS bulk technology. Dynamic power dissipation was also reduced significantly by using this proposed SOI CMOS technology based circuit technique. Standby subthreshold leakage power dissipation and dynamic power dissipation were also reduced significantly using the proposed circuit technique in comparison with other existing techniques, when all circuit techniques were implemented in SOI CMOS technology. All simulations were performed using Microwindver 3.1 EDA tool.
基金supported by the Global Research Laboratory Program(2011-0021874)Brain Korea 21 Program,the Global Core Research Center(GCRC)Program(20110030001)through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT and Future Planning(MSIP)
文摘The central nervous system （CNS） contains the two most important organs, the brain and spinal cord, for the orchestration of the mental and physical activities of life. Because of its importance, the human body has evolved barrier systems to protect CNS tissue from the external environment. This barrier is a membrane composed of tightly apposed cells and is selectively permeable to specific molecules by way of membrane transporters.
文摘This paper outlines the barriers and potential benefits of using standby diesel generators in mitigating the peak demands for commercial and industrial customers. The feasibility of utilizing the standby diesel generators to reduce the electricity bills for customers is carried out by using the hybrid optimization model for electric renewable(HOMER)software. The size of the standby diesel generator and its operational duration are determined based on the lowest cost of electricity obtained from the evaluations. The economic assessments demonstrate that there is potential to reduce the electricity bills for commercial and industrial customers under the existing fuel price and tariffs. The commercial customers under the tariff C2 have the highest potential to save their electricity bills with the use of standby diesel generators for peak reduction. This study demonstrates the potential of the standby diesel generators in peak reduction.
文摘The protection device with low price and high maintenance cost can be used for a long time. In order to improve availability of protection system,a method of increasing redundancy and periodic replacement is proposed. Firstly,the equivalent model of cumulative failure probability was established. Then,the wasting time of the spare part is converted into the working time of the using part.Considering the optimization objective,under the strategy of block replacement, the availability model in infinite period with the maximum availability and the cost model in finite period with the minimum cost are established separately. In this case,we seek out the optimum replacement interval and verify the applicability and validity of the model through contrast and analysis. Finally,the paper gives a brief discussion of future research area about warm standby system maintenance.
文摘In this paper, four new hybrid digital circuit design techniques, namely, hybrid multi-threshold CMOS complete stack technique, hybrid multi-threshold CMOS partial stack technique, hybrid super cutoff complete stack technique and hybrid super cutoff partial stack technique, have been proposed to reduce the subthreshold leakage power dissipation in standby modes. Techniques available in literature are compared with our proposed hybrid circuit design techniques. Performance parameters such as subthreshold leakage power dissipation in active and standby modes, dynamic power dissipation and propagation delay, are compared using existing and proposed hybrid techniques for a two input AND gate. Reduction of subthreshold leakage power dissipation in standby mode is given more importance, in comparison with the other circuit design performance parameters. It is found that there is reduction in subthreshold leakage power dissipation in standby and active modes by 3.5× and 1.15× respectively using the proposed hybrid super cutoff complete stack technique as compared to the existing multi-threshold CMOS (MTCMOS) technique. Also a saving of 2.50× and 1.04× in subthreshold leakage power dissipation in standby and active modes respectively were observed using hybrid super cutoff complete stack technique as compared to the existing super cutoff CMOS (SCCMOS) technique. The proposed hybrid super cutoff stack technique proved to perform better in terms of subthreshold leakage power dissipation in standby mode in comparison with other techniques. Simulation results using Microwind EDA tool in 65 nm CMOS technology is provided in this paper.
文摘This paper we proposed advanced burst mode control technique to reduce the standby power consumption of the switch mode power supply (SMPS). To reduce the standby power consumption, most of the converter use burst mode or skip mode control technique. However Conventional standby mode control techniques have some problems such as audible noise and poor regulation. In proposed techniques, basically, the burst mode control technique is employed to reduce the fundamental switching frequency while limiting the peak drain current. But, in proposed technique, to improve the regulation characteristic, burst period of the proposed technique is shorter than that of the conventional burst mode technique. And also, to reduce the switching loss increase due to the short burst period, burst switching signal of the proposed technique is partially skipped. By using proposed advanced burst mode control technique, calculated standby power is 0.695W while standby power of the conventional burst mode control is 1.014W.
文摘Willing to work in reliability theory in a general set up, under stochastically dependence conditions, we intend to characterize a not identically spare standby redundancy operation through compensator transform under a complete information level, the physic approach, that is, observing its component lifetime. We intend to optimize system reliability under standby redundancy allocation of its components, particularly, under minimal standby redundancy. To get results, we will use a coherent system representation through a signature point process.
基金This work was supported by the National Natural Science Foundation of China[Grant Number 72071175,72001070].
文摘This paper investigates a warm standby repairable retrial system with two types of components and a single reparman,where type 1 components have priority over type 2 in use.Failure and repair times for each type of component are assumed to be exponential distributions.The retrial feature is considered and the retrial time of each failed component is exponentially distributed.By using Markov process theory and matrix analytic method,the system steady-state probabil-ities are derived,and the system steady-state availability and some steady-state performance indices are obtained.Using the Bayesian approach,the system parameters can be estimated.The cost-benefit ratio function of the system is constructed based on the failed components and repairman's states.Numerical experiments are given to evaluate the effect of each parameter on the system steady-state availability and optimize the system cost-benefit ratio with repair rate as a decision variable.
基金Project supported by the National High Technology Research and Development Program of China(Nos.2008AA031401,2011AA010404)the National ST Project(No.2011ZX02502)the Shanghai STC Project(No.12XD1400800)
文摘SRAM standby leakage reduction plays a pivotal role in minimizing the power consumption of ap- plication processors. Generally, four kinds of techniques are often utilized for SRAM standby leakage reduction： Vdd lowering （VDDL）, Vss rising （VSSR）, BL floating （BLF） and reversing body bias （RBB）. In this paper, we comprehensively analyze and compare the reduction effects of these techniques on different kinds of leakage. It is disclosed that the performance of these techniques depends on the leakage composition of the SRAM cell and temperature. This has been verified on a 65 nm SRAM test macro.
