The Irregular Linear Quadratic Control Problem for Deterministic Case with Time Delay

This study deals with the irregular linear quadratic control problem governed by continuous time system with time delay. Linear quadratic(LQ) control for irregular Riccati equation with time delay remains challenging since the controller could not be solved from the equilibrium condition directly. The merit of this paper is that based on a new approach of ‘two-layer optimization', the controller entries of irregular case with time delay are deduced from two equilibrium conditions in two different layers, which is fundamentally different from the classical regular LQ control. The authors prove that the irregular LQ with time delay is essentially different from the regular case. Specifically,the predictive controller bases on the feedback gain matrix and the state is given in the last part. The presented conclusions are completely new to our best knowledge. Examples is presented to show the effectiveness of the proposed approach.     

Method of Generating Strategic Guidance Information for Driving Evacuation Flows to Approach Safety-Based System Optimal Dynamic Flows: Case Study of a Large Stadium

In previous evacuation flow planning, a system optimal dynamic traffic assignment(SODTA) did not consider the exogenous costs caused by potential traffic accidents. A traffic accident,which might occur as a result of traffic congestion, will impact an evacuation process because of accidentrelated delays experienced by the downstream vehicles. This paper establishes a safety-based SO-DTA linear programming model in which the generalized system cost incorporates both the travel time and the accident-related delay. The goal is to minimize the generalized system cost under the cell transmission setup. Furthermore, the authors provide strategic guidance information that considers both the objective of the decision maker and the route choice behavior of the evacuees. Mathematically,the authors propose an unconstrained non-linear programming model aimed at minimizing the gap between the safety-based flows and the stochastic real-world evacuation flows, to provide strategic travel time information to be published on variable message signs(VMS). In the case study, the authors found that the safety-based SO-DTA model can reduce congestion and improve the evacuation efficiency; the stochastic real-world evacuation flows, guided by strategic information, can approach the safety-based flows.     

Application reliability for communication networks and its analysis method

The network reliability is difficult to be evaluated because of the complex relationship among the network components.It can be quite different for different users running different applications on the same network.This paper proposes a new concept and a model of application reliability.Different from the existing models that ignores the effects of applications,the proposed application reliability model considers the effects of different applications on the network performance and different types of network faults and makes the analysis of network components relationship possible.This paper also provides a method to evaluate the application reliability when the data flow satisfies Markov properties.Finally,a case study is presented to illustrate the proposed network reliability model and the analysis method.     

Capacity analysis of transmit beamforming with variable feedback delay

The feedback delay can severely affect the quality of the channel state information at the transmitter (CSIT) which is fed back from the receiver. The outdated CSIT will cause large performance loss in the transmit beamforming systems. The effect of variable feedback delay on the capacity of transmit beamforming systems over Rayleigh fading channels is studied. First, the case of fixed feedback delay is considered and a closed-form expression of system capacity is derived. Based on the results of fixed delay, the delay following certain distributions in variable delay case is assumed and the closed-form expressions of capacities are derived. The closed-form expressions show that the capacity is significantly affected by the statistical characteristics of the feedback delay. The obtained results provide an analytical insight into the effects caused by variable delay on the system capacity.     

Dynamic channel reservation scheme based on priorities in LEO satellite systems

According to low earth orbit(LEO) satellite systems with users of different levels, a dynamic channel reservation scheme based on priorities is proposed. Dynamic calculation of the thresholds for reserved channels is the key of this strategy. In order to obtain the optimal thresholds, the traffic is predicted based on the high-speed deterministic movement property of LEO satellites firstly. Then, a channel allocation model based on Markov is established. Finally, the solution of the model is obtained based on the genetic algorithm. Without user location, this strategy effectively reduces handover failures and improves channel utilization by adjusting dynamically the thresholds according to traffic conditions. The simulation results show that the system’s overall quality of service can be improved by this strategy.     

Impact of Different Forms of Interest Rate Differential on the Flexible Price Monetary Model

In this paper, in order to investigate whether the impact of different forms of interest rate differential may pass on to the flexible price monetary model, two flexible price monetary models, which are separately derived from the generalized monetary models with log-level interest rate differential and that with interest rate differential, are tested for China yuan to US dollar exchange rate. Through Johansen maximum likelihood method, we find that there is little support in the cointegrating coefllcient estimates for both flexible price monetary models for yuan/dollar exchange rate. However, the latter is generally better than the former in the light of sum of squared residual and log likelihood statistics. Therefore, we conclude that there is no transitive impact of different forms of interest rate differential on the flexible price monetary model.     

Characteristic Analysis and Design of Power Flow of Organizations

This thesis has carried on comparative analysis to the power characteristic of 5 kinds of institutional framework of enterprises at first, and has carried on the survey to the domestic and international train of thought in the research about enterprise‘s power, then puts forward the basic contradiction in enterprises organization (“The contradictions of the complexity of management‘s target and people‘s limited reason“) and essential feature ofcurrent enterprise‘s power (“Solidification of power“), and then has put forward new train of thought in the study of enterprise‘s power and organization (“flow of power“), finally has designed the way and direction that the power flowed in enterprises, Combining enterprise‘s life cycle theory and American scholar L.E.Greiner‘s model about organization development.     

State feedback control of network-based systems with packet disordering

A new method that stabilizes network-based systems with both bounded delay and packet disordering is discussed under the state feedback controller. A novel model, fully describing the dynamic characteristic of network-based systems with packet disordering, is constructed. Different from the existing models of network-based systems, the number of delay items is time-varying in the model proposed. Further, this model is converted into a parameter-uncertain discrete-time system with time-varying delay item numbers in terms of matrix theory. Moreover, the less conservative stability condition is obtained by avoiding utilisation of Moon et al.’ inequality and bounding inequalities for quadratic functional terms. By solving a minization problem based on linear matrix inequalities, the state feedback controller is presented. A numerical example is given to illustrate the effectiveness of the proposed method.     

Coordinating a two-echelon supply chain through different contracts under price and promotional effort-dependent demand

Retail price and promotional effort are two important parameters on which demand of a commodity largely depends.This paper develops and analyzes a two-echelon supply chain where market demand depends on both retail price and sales effort.The centralized model is studied as the benchmark case,and the wholesale price-only contract is studied as the base case in which each entity tries to maximize its individual profit.Different contract mechanisms are implemented to outperform the base case in terms of both total chain’s as well as individual profits.Comparisons among the coordinating contracts are provided so that any entity may choose the better one from available contracts after the contract parameters are negotiated.The model is extensively examined through a numerical example.     

Stability of nonlinearly-perturbed systems with time varying delay using LMIs

This paper studies delay dependent robust stability and the stabilization problem of nonlinear perturbed systems with time varying delay. A new set of sufficient conditions for the stability of open as well as close loop systems are obtained in the sense of Lyapunov-Krasovskii. To reduce the conservatism, the work exploits the idea of splitting the delay interval into multiple equal regions so that less information on the time delay can be imposed to derive the results. The derived criterion not only improves the upper bounds of the time delay but also does not require the derivative of the delay to be known at prior. Easily testable sufficient criteria are presented in terms of linear matrix inequalities. It is shown that the derived conditions are very less conservative while comparing the maximum allowable upper bound of delay with the existing results in literature.     

Algorithm of sky-ground-wave signal separation in CDMA system

To solve the problem of the sky-wave interference in radio positioning system operating in CDMA mode, an algorithm of sky-ground-wave separation is provided. Based on the MLE （maximum likelihood estimate）, and by estimating the amplitude and the phase of the sky-wave signal, the provided algorithm for separating skyground-wave is implemented. The mathematics model used for signal processing is established, and the possible solutions are provided. The structure and signal processing flow implementing the presented algorithm in the receiver are presented. A multi-channels signal searching idea is adopted, some of which process the sky-wave signal, and some of which process the ground-wave signal. Numerical analysis and simulation show that the proposed algorithm has higher accuracy, more rapid processing speed, and simpler implementation for the estimation of the sky-wave signal parameter, and can separate the sky-wave signal and ground-wave signal from the arrival combination signal effectively.     

Model algorithm control using neural networks for input delayed nonlinear control system

The performance of the model algorithm control method is partially based on the accuracy of the system’s model. It is difficult to obtain a good model of a nonlinear system, especially when the nonlinearity is high. Neural networks have the ability to "learn"the characteristics of a system through nonlinear mapping to represent nonlinear functions as well as their inverse functions. This paper presents a model algorithm control method using neural networks for nonlinear time delay systems. Two neural networks are used in the control scheme. One neural network is trained as the model of the nonlinear time delay system, and the other one produces the control inputs. The neural networks are combined with the model algorithm control method to control the nonlinear time delay systems. Three examples are used to illustrate the proposed control method. The simulation results show that the proposed control method has a good control performance for nonlinear time delay systems.     

Modeling the congestion cost and vehicle emission within multimodal traffic network under the condition of equilibrium

Traditional system optimization models for traffic network focus on the treatment of congestion, which usually have an objective of minimizing the total travel time.However,the negative externality of congestion,such as environment pollution,is neglected in most cases.Such models fall short in taking Greenhouse Gas(GHG) emissions and its impact on climate change into consideration.In this paper,a social-cost based system optimization(SO) model is proposed for the multimodal traffic network considering both traffic congestion and corresponding vehicle emission.Firstly,a variation inequality model is developed to formulate the equilibrium problem for such network based on the analysis of travelers’ combined choices.Secondly,the computational models of traffic congestion and vehicle emission of whole multimodal network are proposed based on the equilibrium link-flows and the corresponding travel times.A bi-level programming model,in which the social-cost based SO model is treated as the upper-level problem and the combined equilibrium model is processed as the lower-level problem,is then presented with its solution algorithm.Finally,the proposed models are illustrated through a simple numerical example.The study results confirm and support the idea of giving the priority to the development of urban public transport,which is an effective way to achieve a sustainable urban transportation.     

Method of target tracking with Doppler blind zone constraint

Doppler blind zone （DBZ） has a bad influence on the airborne early warning radar, although it has good detection performance for low altitude targets with pulse Doppler （PD） technology. In target tracking, the blind zone can cause target tracking breakage easily. In order to solve this problem, a parallel particle filter （PF） algorithm based on multi-hypothesis motion models （MHMMs） is proposed. The algorithm produces multiple possible target motion models according to the DBZ constraint. Particles are updated with the constraint in each motion model. Once the first measurement from the target which reappears from DBZ falls into the particle cloud formed by any model, the measurementtrack association succeeds and track breakage is avoided. The simulation results show that on the condition of different DBZ ranges, a high association ratio can be got for targets with different maneuverability levels, which accordingly improves the tracking quality.     

An Integrated DEA Model Allowing Decomposition of Eco-Efficiency:A Case Study of China

A common feature of previous studies about the application of data envelopment analysis(DEA) to determine environmental and economic efficiencies is that the two were analyzed in separate models or frameworks. The purpose of this paper is to analyze the economic efficiency and environmental efficiency with a single model. This paper proposes an integrated DEA model, based on a modification of the directional distance function, which allows us to decompose the eco-efficiency(EE) into the economic efficiency(ECE) and environmental efficiency(ENE). The ECE characterizes the ability of gaining economic benefits while the ENE characterizes the ability to control pollutant emissions in production activities. Identification of ECE and ENE can help decision makers of different regions detect what kind of factor(economic inefficiency or environmental inefficiency) is the main source of eco-inefficiency. This can help decision makers more targeted to improve EE. To illustrate the feasibility of our approach, a case study of 30 regions in China is presented. The empirical results show that almost all regions have very high economic efficiencies. The environmental inefficiency is the main source of eco-inefficiency. The differences of environmental efficiencies lead to the differences of eco-efficiencies in the east, central and west areas, while the economic efficiencies do not have significant differences among these areas. The economic efficiencies showed an opposite "V" shape and the environmental efficiencies showed a decreasing trend during the period 2010–2014.     

Nonlinear autopilot design for interceptors with tail fins and pulse thrusters via θ-D approach

The missile autopilot for an interceptor with tail fins and pulse thrusters is designed via the θ-D approach. The nonlin- ear dynamic model of the pitch and yaw motion of the missile is transformed into a linear-like structure with state-dependent coef- ficient （SDC） matrices. Based on the linear-like structure, a θ-D feedback controller is designed to steer the missile to track refer- ence acceleration commands. A sufficient condition that ensures the asymptotic stability of the tracking system is given based on Lyapunov＇s theorem. Numerical results show that the proposed autopilot achieves good tracking performance and the closed-loop tracking system is asymptotically stable.     

Consensus of Flocks under M-Nearest-Neighbor Rules

This paper investigates a class of flocks with an M-nearest-neighbor rule,where each agent’s neighbors are determined according to M nearest agents with M being a given integer,rather than all the agents within a fixed metric distance as in the well-known Vicsek’s model.Such a neighbor rule has been validated by biologists through experiments and the authors will prove that,similar to the Vicsek’s model,such a new neighbor rule can also achieve consensus under some conditions imposed only on the system’s speed and the number M,n,without resorting to any priori connectivity assumptions on the trajectory of the system.In particular,the authors will prove that if the number M is proportional to the population size n,then for any speed v,the system will achieve consensus with large probability if the population size is large enough.     

Research of improving the dynamic scheduling algorithm in the CAN bus control networks

Currently, the article analyzes the CAN bus＇s rule of priority＇s arbitration bit by bit without destroy. It elicits the conclusion that if static priority based on the affirmatory system model is used, the lower priority＇s messages will be delayed considerably more, even some data will be lost when the bus＇s bandwidth is widely used. The scheduling cannot be modified neither during the system when static priority is used. The dynamic priority promoting method and the math model of SQSA and SQMA are presented; it analyzes the model＇s rate of taking in and sending out in large quantities, the largest delay, the problems and solutions when using SQMA. In the end, it is confirmed that the method of improving dynamic priority has good performances on the network rate of taking in and sending out in large quantities, the average delay, and the rate of network usage by emulational experiments.     

A production optimization model of supply-driven chain with quality uncertainty

Supply-driven chain’s production is different from traditional demand-driven production because its supplies must guide the full production flow toward the markets and respond actively to customer demand. According to the control theory, a novel multi-variable operation model of supply-driven chain is discussed here, integrating suppliers, manufacturers, distributors and market demands. Especially the coordination problem between suppliers and manufacturers is discussed where suppliers play more important role than manufacturers. Because defect is common in real production system, the production operation of supply-driven chain with imperfect quality is described on the basis of fuzzy set to model the ambiguity of quality and to provide appropriate supply coordination mechanism. In a designed numerical example, it is apparent that both response and robustness performances of supply-driven production system on demand with imperfect quality are improved by a fuzzy proportional-integral- differential regulator. The proposed model may apply to similar productions with imperfect quality.     

基于元胞自动机的道路交通堵塞仿真研究

意外交通事件的发生会干扰正常的交通流秩序,甚至引起交通堵塞。建立交通意外事件影响下的交通流仿真模型,将能有效地对拥堵传播控制进行研究。对堵塞车流中车辆个体的行为特征进行了详尽分析后,通过设置＂挤车变道＂规则对现有的元胞自动机模型进行了改进,建立起一种适合描述交通堵塞传播的元胞自动机模型。该模型能够较为准确地模拟出堵塞交通流的时空传播过程。最后,利用本模型探索了主要交通流参数对堵塞传播的影响规律。

Abstract：

Traffic incidents will reduce the traffic capacity,and even cause the traffic congestion. So building an effective simulation model is necessary to study the rules of congestion＇s propagating. The behavioral characteristics of individual vehicles in the traffic jam are different from others,but the current traffic CA （cellular automaton） models neglect those differences. The differences were taken into account by introducing some new rules into the old CA model. With the new CA model,the process of traffic congestion＇s propagating could be simulated correctly. Lastly,the relationships between congestion＇s propagating and some traffic parameters were explored by this model.