This paper focuses on the H∞ controller design for linear systems with time-varying delays and norm-bounded parameter perturbations in the system state and control/disturbance. On the existence of delayed/undelayed f...This paper focuses on the H∞ controller design for linear systems with time-varying delays and norm-bounded parameter perturbations in the system state and control/disturbance. On the existence of delayed/undelayed full state feedback controllers, we present a sufficient condition and give a design method in the form of Riccati equation. The controller can not only stabilize the time-delay system, but also make the H∞ norm of the closed-loop system be less than a given bound. This result practically generalizes the related results in current literature.展开更多
There has been an increasing interest in integrating decision support systems (DSS) and expert systems (ES) to provide decision makers a more accessible, productive and domain-independent information and computing env...There has been an increasing interest in integrating decision support systems (DSS) and expert systems (ES) to provide decision makers a more accessible, productive and domain-independent information and computing environment. This paper is aimed at designing a multiple expert systems integrated decision support system (MESIDSS) to enhance decision makers' ability in more complex cases. The basic framework, management system of multiple ESs, and functions of MESIDSS are presented. The applications of MESIDSS in large-scale decision making processes are discussed from the following aspects of problem decomposing, dynamic combination of multiple ESs, link of multiple bases and decision coordinating. Finally, a summary and some ideas for the future are presented.展开更多
To improve the reliability and accuracy of the global po- sitioning system （GPS）/micro electromechanical system （MEMS）- inertial navigation system （INS） integrated navigation system, this paper proposes two diff...To improve the reliability and accuracy of the global po- sitioning system （GPS）/micro electromechanical system （MEMS）- inertial navigation system （INS） integrated navigation system, this paper proposes two different methods. Based on wavelet threshold denoising and functional coefficient autoregressive （FAR） model- ing, a combined data processing method is presented for MEMS inertial sensor, and GPS attitude information is also introduced to improve the estimation accuracy of MEMS inertial sensor errors. Then the positioning accuracy during GPS signal short outage is enhanced. To improve the positioning accuracy when a GPS signal is blocked for long time and solve the problem of the tra- ditional adaptive neuro-fuzzy inference system （ANFIS） method with poor dynamic adaptation and large calculation amount, a self-constructive ANFIS （SCANFIS） combined with the extended Kalman filter （EKF） is proposed for MEMS-INS errors modeling and predicting. Experimental road test results validate the effi- ciency of the proposed methods.展开更多
Based on the information fusion theory, a kind of integrated navigation system integration for cruise missile is presented in this paper. Besides, the way with which the system is integrated and the related data fusio...Based on the information fusion theory, a kind of integrated navigation system integration for cruise missile is presented in this paper. Besides, the way with which the system is integrated and the related data fusion technique are discussed. Information-fusion-based hybrid navigation system integration can fully utilize information provided by all kinds of navigation sensor subsystem and can improve the precision of the system effectively. Simultaneously, the reconstructing ability ensures the system of great reliability.展开更多
The problem of robust stabilization for nonlinear systems with partially known uncertainties is considered in this paper. The required information about uncertainties in the system is merely that the uncertainties are...The problem of robust stabilization for nonlinear systems with partially known uncertainties is considered in this paper. The required information about uncertainties in the system is merely that the uncertainties are bounded, but the upper bounds are incompletely known. This paper can be viewed as an extension of the work in reference [1]. To compensate the uncertainties, an adaptive robust controller based on Lyapunov method is proposed and the design algorithm is also suggested. Compared with some previous controllers which can only ensure ultimate uniform boundedness of the systems, the controller given in the paper can make sure that the obtained closed-loop system is asymptotically stable in the large. Simulations show that the method presented is available and effective.展开更多
A simple criterion for delay-independent stability of large-scale linear time-varying systems is deduced by employing a type of Lyapunov function. The notable features of the results in this paper are its simplicity a...A simple criterion for delay-independent stability of large-scale linear time-varying systems is deduced by employing a type of Lyapunov function. The notable features of the results in this paper are its simplicity and efficiency in testing the stability large-scale linear time-varying systems. Some illustrative examples are given to demonstrate the advantages of the obtained results over those in literature.展开更多
This paper mainly discusses the following problems: the important meaning and special function of simulation system; the definition, contents and relationship of system and system simulation science; the definition an...This paper mainly discusses the following problems: the important meaning and special function of simulation system; the definition, contents and relationship of system and system simulation science; the definition and technology of simulation system and its equipments; and systematic description and exploration in relation to the developing trend of system simulation science and simulation system technology.展开更多
Nowadays, many kinds of computer network data management systems have been built widely in China. People have realized widely that management information system (MIS) has brought a revolution to the management mechani...Nowadays, many kinds of computer network data management systems have been built widely in China. People have realized widely that management information system (MIS) has brought a revolution to the management mechanism. Moreover, the managers of company need wide-range and comprehensive decision information more and more urgently which is the character of information explosion era. The needs of users become harsher and harsher in the design of MIS, and these needs have brought new problems to the general designers of MIS. Furthermore, the current method of traditional database development can't solve so big and complex problems of wide-range and comprehensive information processing. This paper proposes the adoption of parallel processing mode, the built of new decision support system (DSS) is to discuss and analyze the problems of information collection, processing and the acquirement of full-merit information with cross-domain and cross-VLDB (very-large database).展开更多
A marine INS/GPS adaptive navigation system is presented. GPS with two antenna providing vessel＇ s altitude is selected as the auxiliary system fusing with INS to improve the performance of the hybrid system. The Kal...A marine INS/GPS adaptive navigation system is presented. GPS with two antenna providing vessel＇ s altitude is selected as the auxiliary system fusing with INS to improve the performance of the hybrid system. The Kalman filter is the most frequently used algorithm in the integrated navigation system, which is capable of estimating INS errors online based on the measured errors between INS and GPS. The standard Kalman filter （SKF） assumes that the statistics of the noise on each sensor are given. As long as the noise distributions do not change, the Kalman filter will give the optimal estimation. However GPS receiver will be disturbed easily and thus temporally changing measurement noise will join into the outputs of GPS, which will lead to performance degradation of the Kalman filter. Many researchers introduce fuzzy logic control method into innovation-based adaptive estimation adaptive Kalman filtering （IAE-AKF） algorithm, and accordingly propose various adaptive Kalman filters. However how to design the fuzzy logic controller is a very complicated problem still without a convincing solution. A novel IAE-AKF is proposed herein, which is based on the maximum likelihood criterion for the proper computation of the filter innovation covariance and hence of the filter gain. The approach is direct and simple without having to establish fuzzy inference rules. After having deduced the proposed IAEAKF algorithm theoretically in detail, the approach is tested by the simulation based on the system error model of the developed INS/GPS integrated marine navigation system. Simulation results show that the adaptive Kalman filter outperforms the SKF with higher accuracy, robustness and less computation. It is demonstra- ted that this proposed approach is a valid solution for the unknown changing measurement noise exited in the Kalman filter.展开更多
A robust adaptive fuzzy control scheme is presented for a class of strict-feedback nonaffine nonlinear systems with modeling uncertainties and external disturbances by using a backstepping approach.Fuzzy logic systems...A robust adaptive fuzzy control scheme is presented for a class of strict-feedback nonaffine nonlinear systems with modeling uncertainties and external disturbances by using a backstepping approach.Fuzzy logic systems are employed to approximate the unknown parts of the desired virtual controls,and the approximation errors of fuzzy systems are only required to be norm-bounded.The function tanh（·） is introduced to avoid problems associated with sgn（·）.The tracking error is guaranteed to be uniformly ultimately bounded with the aid of an additional adaptive compensation term.Chua＇s circuit system and R o¨ssler system are presented to illustrate the feasibility and effectiveness of the proposed control technique.展开更多
To verify the effectiveness of the integrated importance measure （IIM） for multi-state coherent systems of k level, the definition and physical meaning of IIM are demonstrated. Then, the improvement potential and Δ...To verify the effectiveness of the integrated importance measure （IIM） for multi-state coherent systems of k level, the definition and physical meaning of IIM are demonstrated. Then, the improvement potential and Δ-importance measures are generalized to multi-state coherent systems based on the system performance level, and the relationships between IIM and traditional importance measures are discussed. The characteristics of IIM are demonstrated in both series and parallel systems. Also, an application to an oil transportation system is given. The comparison results show that： （i） IIM has some useful properties that are not possessed by traditional importance measures; （ii） IIM is effective in evaluating the component role in multi-state systems when the component reliability and the failure rate are simultaneously considered.展开更多
This paper deals with the Self-Increasing-Difficulty system (SIDIS) separated from general systems, with emphasis on the relevant methodology based on the Spiral Combining Propulsion Principle (SPIPRO principle in sho...This paper deals with the Self-Increasing-Difficulty system (SIDIS) separated from general systems, with emphasis on the relevant methodology based on the Spiral Combining Propulsion Principle (SPIPRO principle in short). The system feature and its causative factors are analysed, and the implications and mechanism of the SPIPRO principle are discussed. Finally, the application possibilities of this methodology are illustrated with some examples.展开更多
Under the premise of unchanging the collective ownership and the mode of family business, China should choose land shares pack system as the goal pattern of farmland system innovation. It is hoped that the pattern is ...Under the premise of unchanging the collective ownership and the mode of family business, China should choose land shares pack system as the goal pattern of farmland system innovation. It is hoped that the pattern is accepted and supported by both sides of the government and the farmers, and then it constructs the land reasonable circulation and the effective centralism mechanism, thus realizing smooth transition from the traditional agriculture to the modem agriculture.展开更多
Power control is an important technique in WCDMA mobile systems for both increasing system capacity and guaranteeing the required QoS (time delay and wireless link transmission quality) of multimedia services. The opt...Power control is an important technique in WCDMA mobile systems for both increasing system capacity and guaranteeing the required QoS (time delay and wireless link transmission quality) of multimedia services. The optimum power control for narrow band CDMA cellular systems is a problem of single threshold optimization. Because these systems have only one type of traffic and have the same QoS requirement. However, WCDMA mobile system should provide multimedia services and different types of traffic have different QoS requirements. Thus, the power control in WCDMA mobile systems isn't a problem of single threshold optimizing, but turns into the optimizing problem of multi-threshold. We analyze the power control problem in WCDMA cellular mobile systems and propose the optimum transmitter power control algorithm. Three criteria to optimize transmitter power levels of multi-thresholds based on grading the priority orders of multimedia services are proposed. Simulation results show that the proposed algorithms are more effective than conventional algorithms and can provide better performance for WCDMA cellular mobile systems.展开更多
Lookup table is widely used in automotive industry for the design of engine control units(ECU).Together with a proportional-integral controller,a feed-forward and feedback control scheme is often adopted for automotiv...Lookup table is widely used in automotive industry for the design of engine control units(ECU).Together with a proportional-integral controller,a feed-forward and feedback control scheme is often adopted for automotive engine management system(EMS).Usually,an ECU has a structure of multi-input and single-output(MISO).Therefore,if there are multiple objectives proposed in EMS,there would be corresponding numbers of ECUs that need to be designed.In this situation,huge efforts and time were spent on calibration.In this work,a multi-input and multi-out(MIMO) approach based on model predictive control(MPC) was presented for the automatic cruise system of automotive engine.The results show that the tracking of engine speed command and the regulation of air/fuel ratio(AFR) can be achieved simultaneously under the new scheme.The mean absolute error(MAE) for engine speed control is 0.037,and the MAE for air fuel ratio is 0.069.展开更多
The focus of this paper is on a new concept framework and an architecture of an intelligent decision support syetem generator (DSSG). The framework results from a synthesis of two existing frameworks: Spragae and Bonc...The focus of this paper is on a new concept framework and an architecture of an intelligent decision support syetem generator (DSSG). The framework results from a synthesis of two existing frameworks: Spragae and Bonczek, while the architecture is a rooted partial order network. From our experience which comes out of the project of DSSG, we consider that they are keys of further research and development of DSS.展开更多
In this paper, a real-time computation method for the control problems in differential-algebraic systems is presented. The errors of the method are estimated, and the relation between the sampling stepsize and the con...In this paper, a real-time computation method for the control problems in differential-algebraic systems is presented. The errors of the method are estimated, and the relation between the sampling stepsize and the controlled errors is analyzed. The stability analysis is done for a model problem, and the stability region is ploted which gives the range of the sampling stepsizes with which the stability of control process is guaranteed.展开更多
距国际煤和有机岩石学委员会(ICCP)讨论制定新的显微组分分类近30 a后,国际煤地质学杂志(International Journal of Coal Geology)于2017年发表了类脂体新的分类方案“Classification of liptinite-ICCP System 1994”。在此之前,ICCP...距国际煤和有机岩石学委员会(ICCP)讨论制定新的显微组分分类近30 a后,国际煤地质学杂志(International Journal of Coal Geology)于2017年发表了类脂体新的分类方案“Classification of liptinite-ICCP System 1994”。在此之前,ICCP发表了镜质体(ICCP,1998)、惰质体(ICCP,2001)和腐植体(Sykorova等,2005)的分类方案。类脂体新分类方案的发表,标志着ICCP完成了对煤显微组分分类体系的构建。这4个分类方案统称为“ICCP System 1994”。与ICCP的旧分类方案(Stopes Heerlen分类)相比,该类脂体分类适用于所有煤化作用程度的煤和变质程度的沉积岩中的分散有机质。新的类脂体分类方案包括9种显微组分,即角质体、木栓质体、孢子体、树脂体、渗出沥青体、叶绿素体、藻类体、类脂碎屑体、沥青质体。“ICCP system 1994”和中华人民共和国国家标准《烟煤显微组分分类》(GB/T 15588—2013)相比,后者有树皮体和荧光体,并明确地划分出了显微亚组分(即孢粉体分为大孢子体和小孢子体,藻类体分为结构藻类体和层状藻类体)。“ICCP system 1994”有叶绿素体,并将荧光体作为树脂体的一种。其他显微组分在国家标准《烟煤显微组分分类》和“ICCP System 1994”中相互对应。与“ICCP system 1994”的适用范围不同,国家标准《烟煤显微组分分类》适用于中阶煤。展开更多
与镜质体和类脂体相比,惰质体具有明显的惰性,特别是在碳化过程中其惰性更为明显。惰质体的定义和分类是“ICCP system 1994”的重要组成部分。在“ICCP system 1994”中,惰质体包含7种显微组分,不包含亚组。这7种显微组分包括丝质体、...与镜质体和类脂体相比,惰质体具有明显的惰性,特别是在碳化过程中其惰性更为明显。惰质体的定义和分类是“ICCP system 1994”的重要组成部分。在“ICCP system 1994”中,惰质体包含7种显微组分,不包含亚组。这7种显微组分包括丝质体、半丝质体、真菌体、分泌体、粗粒体、微粒体和惰质碎屑体;前3者保存细胞的结构,分泌体、粗粒体、微粒体没有保存植物的细胞结构。对于具有结构的惰质体显微组分,只有那些具有高反射率的组织细胞壁才能鉴定为惰质体的组分。该分类方案有2个突出特点:①真菌体和分泌体替代了旧分类方案中的菌类体;②重新定义了显微组分粗粒体,以便使其与分泌体之间有清晰的分辨界限。真菌体仅包括真菌的遗骸;虽然分泌体和真菌菌核的光学性质近似,但前者实际上是氧化后又经历了煤化作用的植物分泌物。惰质体其他显微组分和旧分类方案(即Stopes Heerlen烟煤显微组分分类方案)没有太大区别。“ICCP system 1994”和国家标准《烟煤显微组分分类》相比,2者之间的显微组分是相互对应的,但是后者多了显微亚组分(即丝质体分为火焚和氧化丝质体;粗粒体分为粗粒体1和粗粒体2)。对煤中丝质体属于火焚成因还是氧化成因或者其他成因,尚存在不同的认识。不同于镜质体的分类适于中阶煤和高阶煤,惰质体的分类适用于从泥炭到变无烟煤整个煤化作用阶段。展开更多
煤的显微组分定义与分类的国际标准"ICCP system 1994"是国际煤和有机岩石学委员会(ICCP)历经26 a(1991-2017)完成,按照显微组分组和发表的时间,该标准共分4个部分,分别是镜质体(1998)、惰质体(2001)、腐质体(2005)和类脂体(2...煤的显微组分定义与分类的国际标准"ICCP system 1994"是国际煤和有机岩石学委员会(ICCP)历经26 a(1991-2017)完成,按照显微组分组和发表的时间,该标准共分4个部分,分别是镜质体(1998)、惰质体(2001)、腐质体(2005)和类脂体(2017)。"ICCP system 1994"目前已被国际上从事煤岩学和有机岩石学研究的科研工作者广泛采用。国际煤和有机岩石学委员会在1994年第46届ICCP年会上确定了镜质体显微组分组、亚组和显微组分的定义和分类,并于1998年发表,它是"ICCP system 1994"重要的组成部分。在"ICCP system 1994"镜质体分类方案中,镜质体显微组分组被划分为3个亚组,结构镜质体亚组、碎屑镜质体亚组和凝胶镜质体亚组,它们分别进一步被划分为2个显微组分。其中,划分亚组的主要依据是植物组织的破环(降解)程度,显微组分之间的区分主要依据是凝胶化程度和(或)形貌特征。该分类体系与ICCP腐植体分类体系紧密关联。基于"ICCP system 1994",对镜质体各亚组和各显微组分的定义、光学特征、物理和化学特征、来源以及实际应用等方面进行了解析,对"ICCP system 1994"中镜质体显微组分分类提出了尽可能规范的中文名称。中华人民共和国国家标准《烟煤显微组分分类》(GB/T 15588—2013)和"ICCP system 1994"相比,前者采用了显微组分组、显微组分和显微亚组分的分类方案,将均质镜质体(Telocollinite;即本文中的胶质结构体Collotelinite)和基质镜质体(Desmocollinite;即本文中的胶质碎屑体Collodetrinite)划入无结构的显微亚组分。展开更多
基金This project was supported by the National Natural Science Foundation of China (No. 69974022).
文摘This paper focuses on the H∞ controller design for linear systems with time-varying delays and norm-bounded parameter perturbations in the system state and control/disturbance. On the existence of delayed/undelayed full state feedback controllers, we present a sufficient condition and give a design method in the form of Riccati equation. The controller can not only stabilize the time-delay system, but also make the H∞ norm of the closed-loop system be less than a given bound. This result practically generalizes the related results in current literature.
文摘There has been an increasing interest in integrating decision support systems (DSS) and expert systems (ES) to provide decision makers a more accessible, productive and domain-independent information and computing environment. This paper is aimed at designing a multiple expert systems integrated decision support system (MESIDSS) to enhance decision makers' ability in more complex cases. The basic framework, management system of multiple ESs, and functions of MESIDSS are presented. The applications of MESIDSS in large-scale decision making processes are discussed from the following aspects of problem decomposing, dynamic combination of multiple ESs, link of multiple bases and decision coordinating. Finally, a summary and some ideas for the future are presented.
基金supported by the National Natural Science Foundation of China (60902055)
文摘To improve the reliability and accuracy of the global po- sitioning system （GPS）/micro electromechanical system （MEMS）- inertial navigation system （INS） integrated navigation system, this paper proposes two different methods. Based on wavelet threshold denoising and functional coefficient autoregressive （FAR） model- ing, a combined data processing method is presented for MEMS inertial sensor, and GPS attitude information is also introduced to improve the estimation accuracy of MEMS inertial sensor errors. Then the positioning accuracy during GPS signal short outage is enhanced. To improve the positioning accuracy when a GPS signal is blocked for long time and solve the problem of the tra- ditional adaptive neuro-fuzzy inference system （ANFIS） method with poor dynamic adaptation and large calculation amount, a self-constructive ANFIS （SCANFIS） combined with the extended Kalman filter （EKF） is proposed for MEMS-INS errors modeling and predicting. Experimental road test results validate the effi- ciency of the proposed methods.
文摘Based on the information fusion theory, a kind of integrated navigation system integration for cruise missile is presented in this paper. Besides, the way with which the system is integrated and the related data fusion technique are discussed. Information-fusion-based hybrid navigation system integration can fully utilize information provided by all kinds of navigation sensor subsystem and can improve the precision of the system effectively. Simultaneously, the reconstructing ability ensures the system of great reliability.
文摘The problem of robust stabilization for nonlinear systems with partially known uncertainties is considered in this paper. The required information about uncertainties in the system is merely that the uncertainties are bounded, but the upper bounds are incompletely known. This paper can be viewed as an extension of the work in reference [1]. To compensate the uncertainties, an adaptive robust controller based on Lyapunov method is proposed and the design algorithm is also suggested. Compared with some previous controllers which can only ensure ultimate uniform boundedness of the systems, the controller given in the paper can make sure that the obtained closed-loop system is asymptotically stable in the large. Simulations show that the method presented is available and effective.
文摘A simple criterion for delay-independent stability of large-scale linear time-varying systems is deduced by employing a type of Lyapunov function. The notable features of the results in this paper are its simplicity and efficiency in testing the stability large-scale linear time-varying systems. Some illustrative examples are given to demonstrate the advantages of the obtained results over those in literature.
文摘This paper mainly discusses the following problems: the important meaning and special function of simulation system; the definition, contents and relationship of system and system simulation science; the definition and technology of simulation system and its equipments; and systematic description and exploration in relation to the developing trend of system simulation science and simulation system technology.
文摘Nowadays, many kinds of computer network data management systems have been built widely in China. People have realized widely that management information system (MIS) has brought a revolution to the management mechanism. Moreover, the managers of company need wide-range and comprehensive decision information more and more urgently which is the character of information explosion era. The needs of users become harsher and harsher in the design of MIS, and these needs have brought new problems to the general designers of MIS. Furthermore, the current method of traditional database development can't solve so big and complex problems of wide-range and comprehensive information processing. This paper proposes the adoption of parallel processing mode, the built of new decision support system (DSS) is to discuss and analyze the problems of information collection, processing and the acquirement of full-merit information with cross-domain and cross-VLDB (very-large database).
基金This project was supported by the National Natural Science Foundation of China (40125013 &40376011)
文摘A marine INS/GPS adaptive navigation system is presented. GPS with two antenna providing vessel＇ s altitude is selected as the auxiliary system fusing with INS to improve the performance of the hybrid system. The Kalman filter is the most frequently used algorithm in the integrated navigation system, which is capable of estimating INS errors online based on the measured errors between INS and GPS. The standard Kalman filter （SKF） assumes that the statistics of the noise on each sensor are given. As long as the noise distributions do not change, the Kalman filter will give the optimal estimation. However GPS receiver will be disturbed easily and thus temporally changing measurement noise will join into the outputs of GPS, which will lead to performance degradation of the Kalman filter. Many researchers introduce fuzzy logic control method into innovation-based adaptive estimation adaptive Kalman filtering （IAE-AKF） algorithm, and accordingly propose various adaptive Kalman filters. However how to design the fuzzy logic controller is a very complicated problem still without a convincing solution. A novel IAE-AKF is proposed herein, which is based on the maximum likelihood criterion for the proper computation of the filter innovation covariance and hence of the filter gain. The approach is direct and simple without having to establish fuzzy inference rules. After having deduced the proposed IAEAKF algorithm theoretically in detail, the approach is tested by the simulation based on the system error model of the developed INS/GPS integrated marine navigation system. Simulation results show that the adaptive Kalman filter outperforms the SKF with higher accuracy, robustness and less computation. It is demonstra- ted that this proposed approach is a valid solution for the unknown changing measurement noise exited in the Kalman filter.
基金supported by the National Natural Science Foundation of China (9071602811001128)
文摘A robust adaptive fuzzy control scheme is presented for a class of strict-feedback nonaffine nonlinear systems with modeling uncertainties and external disturbances by using a backstepping approach.Fuzzy logic systems are employed to approximate the unknown parts of the desired virtual controls,and the approximation errors of fuzzy systems are only required to be norm-bounded.The function tanh（·） is introduced to avoid problems associated with sgn（·）.The tracking error is guaranteed to be uniformly ultimately bounded with the aid of an additional adaptive compensation term.Chua＇s circuit system and R o¨ssler system are presented to illustrate the feasibility and effectiveness of the proposed control technique.
基金supported by the National Natural Science Foundation of China (7110111671271170)+2 种基金the National Basic Research Program of China (973 Progrom) (2010CB328000)the National High Technology Research and Development Program of China (863 Progrom) (2012AA040914)the Basic Research Foundation of Northwestern Polytechnical University (JC20120228)
文摘To verify the effectiveness of the integrated importance measure （IIM） for multi-state coherent systems of k level, the definition and physical meaning of IIM are demonstrated. Then, the improvement potential and Δ-importance measures are generalized to multi-state coherent systems based on the system performance level, and the relationships between IIM and traditional importance measures are discussed. The characteristics of IIM are demonstrated in both series and parallel systems. Also, an application to an oil transportation system is given. The comparison results show that： （i） IIM has some useful properties that are not possessed by traditional importance measures; （ii） IIM is effective in evaluating the component role in multi-state systems when the component reliability and the failure rate are simultaneously considered.
文摘This paper deals with the Self-Increasing-Difficulty system (SIDIS) separated from general systems, with emphasis on the relevant methodology based on the Spiral Combining Propulsion Principle (SPIPRO principle in short). The system feature and its causative factors are analysed, and the implications and mechanism of the SPIPRO principle are discussed. Finally, the application possibilities of this methodology are illustrated with some examples.
文摘Under the premise of unchanging the collective ownership and the mode of family business, China should choose land shares pack system as the goal pattern of farmland system innovation. It is hoped that the pattern is accepted and supported by both sides of the government and the farmers, and then it constructs the land reasonable circulation and the effective centralism mechanism, thus realizing smooth transition from the traditional agriculture to the modem agriculture.
文摘Power control is an important technique in WCDMA mobile systems for both increasing system capacity and guaranteeing the required QoS (time delay and wireless link transmission quality) of multimedia services. The optimum power control for narrow band CDMA cellular systems is a problem of single threshold optimization. Because these systems have only one type of traffic and have the same QoS requirement. However, WCDMA mobile system should provide multimedia services and different types of traffic have different QoS requirements. Thus, the power control in WCDMA mobile systems isn't a problem of single threshold optimizing, but turns into the optimizing problem of multi-threshold. We analyze the power control problem in WCDMA cellular mobile systems and propose the optimum transmitter power control algorithm. Three criteria to optimize transmitter power levels of multi-thresholds based on grading the priority orders of multimedia services are proposed. Simulation results show that the proposed algorithms are more effective than conventional algorithms and can provide better performance for WCDMA cellular mobile systems.
基金Project supported by the Centre for Smart Grid and Information Convergence(CeSGIC)at Xi’an Jiaotong-Liverpool University,China
文摘Lookup table is widely used in automotive industry for the design of engine control units(ECU).Together with a proportional-integral controller,a feed-forward and feedback control scheme is often adopted for automotive engine management system(EMS).Usually,an ECU has a structure of multi-input and single-output(MISO).Therefore,if there are multiple objectives proposed in EMS,there would be corresponding numbers of ECUs that need to be designed.In this situation,huge efforts and time were spent on calibration.In this work,a multi-input and multi-out(MIMO) approach based on model predictive control(MPC) was presented for the automatic cruise system of automotive engine.The results show that the tracking of engine speed command and the regulation of air/fuel ratio(AFR) can be achieved simultaneously under the new scheme.The mean absolute error(MAE) for engine speed control is 0.037,and the MAE for air fuel ratio is 0.069.
文摘The focus of this paper is on a new concept framework and an architecture of an intelligent decision support syetem generator (DSSG). The framework results from a synthesis of two existing frameworks: Spragae and Bonczek, while the architecture is a rooted partial order network. From our experience which comes out of the project of DSSG, we consider that they are keys of further research and development of DSS.
文摘In this paper, a real-time computation method for the control problems in differential-algebraic systems is presented. The errors of the method are estimated, and the relation between the sampling stepsize and the controlled errors is analyzed. The stability analysis is done for a model problem, and the stability region is ploted which gives the range of the sampling stepsizes with which the stability of control process is guaranteed.
文摘距国际煤和有机岩石学委员会(ICCP)讨论制定新的显微组分分类近30 a后,国际煤地质学杂志(International Journal of Coal Geology)于2017年发表了类脂体新的分类方案“Classification of liptinite-ICCP System 1994”。在此之前,ICCP发表了镜质体(ICCP,1998)、惰质体(ICCP,2001)和腐植体(Sykorova等,2005)的分类方案。类脂体新分类方案的发表,标志着ICCP完成了对煤显微组分分类体系的构建。这4个分类方案统称为“ICCP System 1994”。与ICCP的旧分类方案(Stopes Heerlen分类)相比,该类脂体分类适用于所有煤化作用程度的煤和变质程度的沉积岩中的分散有机质。新的类脂体分类方案包括9种显微组分,即角质体、木栓质体、孢子体、树脂体、渗出沥青体、叶绿素体、藻类体、类脂碎屑体、沥青质体。“ICCP system 1994”和中华人民共和国国家标准《烟煤显微组分分类》(GB/T 15588—2013)相比,后者有树皮体和荧光体,并明确地划分出了显微亚组分(即孢粉体分为大孢子体和小孢子体,藻类体分为结构藻类体和层状藻类体)。“ICCP system 1994”有叶绿素体,并将荧光体作为树脂体的一种。其他显微组分在国家标准《烟煤显微组分分类》和“ICCP System 1994”中相互对应。与“ICCP system 1994”的适用范围不同,国家标准《烟煤显微组分分类》适用于中阶煤。
文摘与镜质体和类脂体相比,惰质体具有明显的惰性,特别是在碳化过程中其惰性更为明显。惰质体的定义和分类是“ICCP system 1994”的重要组成部分。在“ICCP system 1994”中,惰质体包含7种显微组分,不包含亚组。这7种显微组分包括丝质体、半丝质体、真菌体、分泌体、粗粒体、微粒体和惰质碎屑体;前3者保存细胞的结构,分泌体、粗粒体、微粒体没有保存植物的细胞结构。对于具有结构的惰质体显微组分,只有那些具有高反射率的组织细胞壁才能鉴定为惰质体的组分。该分类方案有2个突出特点:①真菌体和分泌体替代了旧分类方案中的菌类体;②重新定义了显微组分粗粒体,以便使其与分泌体之间有清晰的分辨界限。真菌体仅包括真菌的遗骸;虽然分泌体和真菌菌核的光学性质近似,但前者实际上是氧化后又经历了煤化作用的植物分泌物。惰质体其他显微组分和旧分类方案(即Stopes Heerlen烟煤显微组分分类方案)没有太大区别。“ICCP system 1994”和国家标准《烟煤显微组分分类》相比,2者之间的显微组分是相互对应的,但是后者多了显微亚组分(即丝质体分为火焚和氧化丝质体;粗粒体分为粗粒体1和粗粒体2)。对煤中丝质体属于火焚成因还是氧化成因或者其他成因,尚存在不同的认识。不同于镜质体的分类适于中阶煤和高阶煤,惰质体的分类适用于从泥炭到变无烟煤整个煤化作用阶段。
文摘煤的显微组分定义与分类的国际标准"ICCP system 1994"是国际煤和有机岩石学委员会(ICCP)历经26 a(1991-2017)完成,按照显微组分组和发表的时间,该标准共分4个部分,分别是镜质体(1998)、惰质体(2001)、腐质体(2005)和类脂体(2017)。"ICCP system 1994"目前已被国际上从事煤岩学和有机岩石学研究的科研工作者广泛采用。国际煤和有机岩石学委员会在1994年第46届ICCP年会上确定了镜质体显微组分组、亚组和显微组分的定义和分类,并于1998年发表,它是"ICCP system 1994"重要的组成部分。在"ICCP system 1994"镜质体分类方案中,镜质体显微组分组被划分为3个亚组,结构镜质体亚组、碎屑镜质体亚组和凝胶镜质体亚组,它们分别进一步被划分为2个显微组分。其中,划分亚组的主要依据是植物组织的破环(降解)程度,显微组分之间的区分主要依据是凝胶化程度和(或)形貌特征。该分类体系与ICCP腐植体分类体系紧密关联。基于"ICCP system 1994",对镜质体各亚组和各显微组分的定义、光学特征、物理和化学特征、来源以及实际应用等方面进行了解析,对"ICCP system 1994"中镜质体显微组分分类提出了尽可能规范的中文名称。中华人民共和国国家标准《烟煤显微组分分类》(GB/T 15588—2013)和"ICCP system 1994"相比,前者采用了显微组分组、显微组分和显微亚组分的分类方案,将均质镜质体(Telocollinite;即本文中的胶质结构体Collotelinite)和基质镜质体(Desmocollinite;即本文中的胶质碎屑体Collodetrinite)划入无结构的显微亚组分。
