This paper describes a method of modeling the engineeringdesign process and a simulation that implements the model. The model explicitly represents the communication requirements of interdependent design projects and...
详细信息
User interface design is a complex task within the development of interactive software, and not sufficiently supported in general software development. We present MEMFIS, a method laid out for development of software ...
详细信息
This thesis focuses on modeling physical systems. Specifically, it is about enhancing a human's ability to select standard-part models for specific tasks. In this thesis we define the word "model" as any...
详细信息
This thesis focuses on modeling physical systems. Specifically, it is about enhancing a human's ability to select standard-part models for specific tasks. In this thesis we define the word "model" as any representation system whose behavior is analogous to the behavior of some other object or system. Furthermore, we define "modeling" as the activity of creating a representation of an artifact that captures behavioral features significant to the modeling agent. modeling complex physical systems is a difficult, error-prone, time consuming activity and requires skilled and experienced practitioners. Constructing an adequate model is a necessary step towards effectively reasoning about physical systems and in most cases the user constructs the device model. Although complete automation of practical physical system modeling is still beyond current technology, supplying a repository of standard parts could alleviate some of modeling difficulties. As a basis for addressing modeling difficulties, we focus on modeling a large-scale, complex system from a realistic domain using the Functional modeling (FM) approach, as well as enhancing a modeler's ability to select adequate models from a standard part library. We first examine the feasibility of Functional modeling for reverse engineering of physical systems for the purpose of consequence finding. We then investigate the scalability of Functional modeling in a realistic, heterogenous domain drawn from the aerospace industry. The term "scalability" is used to signify the ability of FM to scale to larger sized systems and to model a system in a profoundly different domain than the previously investigated domains. We investigate the issues of component connectivity and substance flow. We construct a representational framework to incorporate the connectivity enhancement to the current theory of the Functional modeling. We define a standard part as an abstraction of a known, off-the-shelf artifact, suitable for instantiation and
As an important portion of the brain system, the hippocampus performs cognitive functions of learning and memory. VLSI implementation of a hippocampal model has been proposed and a mixed analog-digital chip which uses...
详细信息
As an important portion of the brain system, the hippocampus performs cognitive functions of learning and memory. VLSI implementation of a hippocampal model has been proposed and a mixed analog-digital chip which uses analog circuits for parallel computing and digital circuit for interconnection was designed. The design with one extensive hippocampal neuron has been sent for fabrication. One of the objectives of this research effort is to incorporate adequate biological constraints as possible into the hardware design.
The problem of designing individual macrocells for a library with power and speed considerations is addressed here. A new technique for optimization using posynomial approximating functions is devised. In the design o...
详细信息
The problem of designing individual macrocells for a library with power and speed considerations is addressed here. A new technique for optimization using posynomial approximating functions is devised. In the design of each macrocell, optimality in design is critical and highly accurate techniques for measuring the performance are required during optimization. This paper presents methods for accurately estimating the worst-case contribution of the power and delay of a cell to a circuit. The program uses circuit-level simulation to calculate the power dissipation and delay of the cell with the highest accuracy. A rationale for using arbitrary degree posynomial modeling functions for area, delay and power modeling is presented. The problem is then formulated as a convex programming problem, and a rigorous optimization technique is used to arrive at the optimal macrocell.
In this paper, a simple analytical model for estimating standby and switching power dissipation in deep submicron CMOS digital circuits is introduced. The model is based on Berkeley Short-Channel (BSIM) model and fits...
详细信息
In this paper, a simple analytical model for estimating standby and switching power dissipation in deep submicron CMOS digital circuits is introduced. The model is based on Berkeley Short-Channel (BSIM) model and fits HSPICE simulation results well. A design methodology to minimize the power-delay product by selecting the lower and upper bounds of the supply and threshold voltages is presented.
In-this paper, we present an efficient and accurate I/sub DDQ/ fault modeling technique for digital CMOS circuit. Both the normal and faulty "current" behaviors of a CMOS digital circuit can be described by ...
详细信息
In-this paper, we present an efficient and accurate I/sub DDQ/ fault modeling technique for digital CMOS circuit. Both the normal and faulty "current" behaviors of a CMOS digital circuit can be described by this model. Also the parasitic capacitive and inductive parameters can be emulated. A formal method for creating this model from any given CMOS circuit is obtained. Using this model, circuit design of built-in current sensors (BICSs) can be designed and validated without introducing the actual circuit under test (CUT) which implanted a fault. Experimental data for the application to the design of BICSs is also given.
The Sea Water Lift Pump(SLP) system is responsible for maintaining the open canal level to provide the suction flow of Circulating Water Pump(CWP) at the set point. The response of the SLP system is so slow that it is...
详细信息
The Sea Water Lift Pump(SLP) system is responsible for maintaining the open canal level to provide the suction flow of Circulating Water Pump(CWP) at the set point. The response of the SLP system is so slow that it is difficult to maintain an optimal open canal level by manual or two step pump speed control operation and to reduce overflow of seawater. The objective of this paper is to apply the fuzzy control method, which can utilize the flexibility and the heuristic operation strategy employed by operators, to SLP system in fossil fired power plant. In order to verify a proposed fuzzy system, we developed simplified models such as mathematical model of SLP, CWP, seawater level and intake canal. The result of the simulation test shows that the proposed fuzzy control method can reflect successfully the experience gained in skilled manual operation. It is expected that the fuzzy control can contribute to the reduction of power consumption of SLP, human error and man power, and to the improvement of the reliability and safety of the plant operation.
Dimensional analysis enables engineers to reduce the computational complexity of engineering analysis and effectively utilize dynamic scale modeling and simulation. Prior to the age of powerful digital computers and n...
详细信息
Dimensional analysis enables engineers to reduce the computational complexity of engineering analysis and effectively utilize dynamic scale modeling and simulation. Prior to the age of powerful digital computers and numerical methods for complex design problems, dimensional analysis was critical to the development of large scale complex dynamic physical systems. While fuzzy mathematics provides the tools for dealing with fuzzy systems, complexity of problem formulation and computation costs still seriously limit analysis of large scale "people-in-the-loop" fuzzy systems. Use of dimensional analysis should improve the quality, lower costs and reduce the time to analyze complex fuzzy systems.
The CERN Research and Development project (RD-38), named CICERO [1], aims to identify and design the main building blocks of a generic control information system based on distributed objects. The project is producing ...
详细信息
The CERN Research and Development project (RD-38), named CICERO [1], aims to identify and design the main building blocks of a generic control information system based on distributed objects. The project is producing an integrating framework (named Cortex [2]) into which user real-time control objects will ultimately be plugged (and played) and a control information system to support its configuration and management. Development of Cortex is following the ESA PSS-05-02 software engineering standards [3]. Cortex is providing an environment which allows real-time control systems to share information, control and analysis functions;which presents a uniform human interface;which permits upgrades and additions without code modification;and which is sufficiently generic to allow its use both by existing or future control systems at CERN and by industrial real time control systems. It provides both high level data access, abstracting objects to a level appropriate for on-line control and low level data access to allow views of experimental sub-components for detailed real-time control. Additionally, the Cortex system shall enable developers to grow their control systems from a lab-based test system to the complete experimental system and is therefore both scaleable and flexible to change. Technical solutions are being identified in CICERO which could later be the major components of a basic turnkey control system for future medium to large scale HEP experiments and accelerators as well as for industrial control systems. This paper outlines the modelling concepts behind Cortex.
暂无评论