A method of reducing overhead caused by the processor synchronization process and common memory access in finely grained tasks is described. The authors propose a hardware configuration to eliminate the synchronizatio...
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A method of reducing overhead caused by the processor synchronization process and common memory access in finely grained tasks is described. The authors propose a hardware configuration to eliminate the synchronization time and a scheduler which minimizes the redundant accesses to shared memory. The proposed scheduler algorithm is processed in parallel. The processes share the common upper bound and the lower bound function which includes the preparation time for shared memory access. The effectiveness of the proposed scheme was confirmed by applying it to the computation of Newton-Euler equations for dynamic arm control, using a multiple digital signal processing system with four TMS320C25 processors.< >
Based on the SCARA concept, accepted worldwide, this paper considers the possibility of realizing SCARA with a full circle working area. The basis of the approach is a mechanism with two eccentrically positioned rotat...
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Based on the SCARA concept, accepted worldwide, this paper considers the possibility of realizing SCARA with a full circle working area. The basis of the approach is a mechanism with two eccentrically positioned rotating discs instead of two joined links. In this way, apart from a circular working area and some other advantages, the installation of several tools (hands) is also facilitated. This paper analyzes the advantages of the proposed solution and the possibilities of its realization.
A novel protocol under a priority time constraint for real-time communication systems is proposed. This protocol can maintain two priority classes. The characteristics of the proposed protocol and its features are pre...
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A novel protocol under a priority time constraint for real-time communication systems is proposed. This protocol can maintain two priority classes. The characteristics of the proposed protocol and its features are presented, and a simulator is built to examine its performance. The performance of the protocol is compared with that of the virtual-time carrier sense multiple-access (VT-CSMA) protocol. The results show that, although the proposed protocol has less throughput than the VT-CSMA protocol, its behavior is better than that of VT-CSMA with respect to high-priority packets. This behavior is the main goal of the protocol, which reduces high-priority-packet loss.< >
This paper presents details in the implementation of an adaptive autopilot unit used for ship course keeping and course changing. The control strategy is based on the scheme of self-tuning regulator (STR) in which the...
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This paper presents details in the implementation of an adaptive autopilot unit used for ship course keeping and course changing. The control strategy is based on the scheme of self-tuning regulator (STR) in which the generalized minimum variance (GMV) control law is combined with an extended least square (ELS) parameter identification technique. A time-varying extended state Kaiman filter (EKF) is designed to estimate the state of the system under disturbances induced by the sea environment and loading conditions. ELS and EKF constitute an adaptive estimator by which both state vector and parameter vector can be estimated properly. A dual microcomputer system using warm standby redundant design is implemented to guarantee the reliability in the control and safety in the steering. The construction principles of hardware and software are discussed. A sophisticated simulation facility is extensively used in the design stage of the autopilot unit. Several sea trials have been performed at “DAQING 232”, a 15000 tdw tanker, the results of which show that the unit reduces the propulsion losses of the ship motion in addition to keeping the course satisfactorily.
The problem of determining a shaping filter which minimized the output roundoff-noise variance is discussed. It is shown that in the family of shaping filters of an identical McMillan degree having an identical power ...
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The problem of determining a shaping filter which minimized the output roundoff-noise variance is discussed. It is shown that in the family of shaping filters of an identical McMillan degree having an identical power spectrum, the shaping filter of minimum phase attains a minimum output roundoff-noise variance in either the case of optimal word lengths or the case of equal word lengths. It is shown out by examples that this is not valid in the family of shaping filters having an identical power spectrum and different McMillan degrees.
The interpreting and analysis of real time sampled signals is important for improvement of quality of products. This article developed an expert system shell ASESS for interpreting and analyzing the real time signals ...
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The interpreting and analysis of real time sampled signals is important for improvement of quality of products. This article developed an expert system shell ASESS for interpreting and analyzing the real time signals ...
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The interpreting and analysis of real time sampled signals is important for improvement of quality of products. This article developed an expert system shell ASESS for interpreting and analyzing the real time signals based on the analysis-synthesis (A-S) inference technology which frequently used by human expert in considering complex problems. The A-S technology is introduced. In order to meet the need of speed of real time control, in ASESS two measures are taken: 1. Knowledge classification and meta-rules are applied. 2. The system is developed with the combination of three languages: Assembler, Fortran and Prolog. Considering the vagueness in inference of human experts, the fuzzy inference technology are applied. The knowledge base of ASESS can be separated from inference engine and can be edited easily, so the system ASESS can be used effectively in different cases by adding appropriate knowledge in that field.
In this paper we attempt to propose a method for preference degree analysis in multiobjective decisionmaking problems(MDMPs), called the multiple factor analysis method based on a hierarchical analysis model. The conc...
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In this paper we attempt to propose a method for preference degree analysis in multiobjective decisionmaking problems(MDMPs), called the multiple factor analysis method based on a hierarchical analysis model. The concept of preference degree(PD) is first discussed. Here a PD is used as a measurement for describing preference information of decision makers (DMs) to some value of an objective. A hierarchical model for analyzing the preference information is then deduced by defining objective domain of discourse (ODD), fuzzy degree domain of discourse (FDDD), factor domain of discourse (FDD) and sensitivity vector. Furthermore, some methods are explored for analyzing DMs* PDs of objective values according to a single factor and multiple factors, respectively. At last, an example is briefly introduced.
An on-line scheme to fault detection in adaptive control systems is proposed by introducing Kullbaek Discrimination Information (KDI) as a detection index. When a physical parameter change due to a failure has occurre...
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An on-line scheme to fault detection in adaptive control systems is proposed by introducing Kullbaek Discrimination Information (KDI) as a detection index. When a physical parameter change due to a failure has occurred in a system under adaptive control, the failure effect will hardly be visible in the output performance because of the adaptation mechanism. Such a parameter change is also difficult to detect by monitoring the regulator parameters, which are determined by a recursive identification based on the direct approach. Since the failure effect is reflected as a change in the predictor model used for the adaptive control design, the fault detection leads to a model discrimination problem. It has been shown that the KDI can be used as an effective distortion measure for the model discrimination and the index can be applied in a modified form to detect a fault on-line. Simulation studies on a second order damped oscillatory system have been carried out to demonstrate the efficiency of the method.
A general formula for the slope and mathematical models of digitized straight-line segments are derived and discussed in detail. The models are parametric and the parameters are calculated uniquely and in closed form ...
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ISBN:
(纸本)0818608781
A general formula for the slope and mathematical models of digitized straight-line segments are derived and discussed in detail. The models are parametric and the parameters are calculated uniquely and in closed form from the slope without the need for recursion or interaction. The modeling is information-preserving and explicitly uses the slope. The models are in a form convenient for plotting, detecting, and recognizing digitized straight-line segments.< >
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