Shigemichi Suzuki

An approximation method for line production rate of a serial production line with a common buffer

Abstract A serial, synchronized, and multi-stage production line with a finite common buffer storage is considered. The capacity of the common buffer storage is shared among all stages. It is assumed that every stage has a geometric distribution of up cycles. When an arriving customer can enter this line if space is available, the independent balance does not hold because of blocking. Since it is necessary to solve a large scale system of simultaneous linear equations to obtain the exact solution of the steady state output rate of the line without independent balance, we propose an efficient method to obtain a good approximate solution. The method is compared with exact solutions or computer simulations, and found to be reasonably accurate.

Graphical editing and analysis system for network system (Geans)

Abstract Network analysis is powerful in building formal network models of various computational systems or social systems and obtaining their functions and performance exactly because of simplicity of binary relations in networks. Traditionally, it takes lots of effort in network analysis because network analysis was performed by the use of lots of numerical data in batch processing form. Effective network analysis activity, satisfying the system requirements based on consideration for such traditional manner with high cost, requires semiautomatic or computer aided man-machine facilities with interactive editing, analysis, and result viewing functions. We have developed Graphical Editing and Analysis system for Network System (Geans) on DEC PDP-11/34 minicomputer with a graphic display which enables us to edit or modify various network representations and analyze their qualitative and quantitative property, smoothly and interactively with the use of graphics and data abstraction. Geans is composed of a network editing system with effective use of a graphic display, a network data management system with systematic use of network data abstraction, a network analysis system with construction of shared library routines and specific object problem oriented routines, and a node/arc shape definition system. Geans has been applied to various network models such as a transportation analysis problem, PERT/CPM planning, Petri Net analysis and a guidance system for an urban railway network, and moreover it is being applied to other analysis areas as evolving itself.

The design of a precompensator for multivariable adaptive control-a network-theoretic approach

A network-theoretic approach to the design of a dynamic precompensator C(s) for a multiinput, multioutput plant T(s) is considered. The design is based on the relative degree of each element of T(s). Specifically, an efficient algorithm is presented for determining whether a given plant T(s) has a diagonal precompensator C(s) such that, for almost all cases, T(s)C(s) has a diagonal interactor. The algorithm also finds any optimal precompensator, in the sense that the total relative degree is minimal. The algorithm can be easily modified to work even when a T(s) represented by a nonsquare matrix is given. >

Man-machine interactive guidance for urban railway networks

Abstract A passenger requires precise and timely guidance information about his path from origin to destination on an urban railway network, e.g. the shortest time path and the minimal cost path. Such two paths are not easy to estimate because the former path is dynamically varied in time-dependent fashion by the ununiformity of train traffic density on time and by the mixture of different train traffic scheduling systems of several companies and the latter path may be composed of one or more lines operated by several companies with their different fare systems. This paper clarifies smooth and effective interaction steps for the guidance for urban railway networks, enumerates I/O devices suitable for the effective guidance, enumerates data items to be required for the effective guidance, clarifies the relationships among them, describes the problems in solving the shortest time path and the minimal cost path, shows our newly devised two analysis algorithms, and shows the overview of the pilot system of our man-machine guidance system in terms of a graphic display.

Graphics for dynamic analysis/synthesis of vibration systems with arbitrary degrees-of-freedom (DAVIS)

Abstract Analysis or synthesis for a vibration system with multi degrees-of-freedom, which is composed of some pointmasses, springs, dashpots and so on, is also an object of the so-called circuit theory. Traditionally, in analysis or synthesis for such a system, tremendous efforts are required such as reformulation of the equations of motion and alteration of computer programs manually even when the system must be slightly modified. Moreover, even if a system with a few degrees-of-freedom is dealt with, it is not easy to understand rapidly the dynamic behavior of the whole system. One of the methods of increasing the efficiency of analysis and synthesis is to introduce computer aided man-machine interactive facilities. We have developed a graphical editing and Dynamic Analysis system for VIbration Systems with arbitrary degrees-of-freedom (DAVIS) on PDP-11/34 minicomputer. DAVIS enables us to edit or modify interactively various representations of systems with arbitrary degrees-of-freedom, to formulate automatically the governing equations, and to understand intuitively dynamic behaviors of the whole system based on dynamic result viewing functions of a graphic display. Especially DAVIS has been developed in consideration of a network property of the systems and also enables us simultaneous analysis for some topologically unconnected systems. DAVIS permits the user who has no knowledge about internal organization of network data to implement dynamic simulations of vibration systems with arbitrary degrees-of-freedom. DAVIS can be used not only for educational but also for practical purposes.