Modular interactive analysis-design of prestressed concrete structural elements

A computer system for interactive analysis-design of pretensioned prestressed concrete members has been developed adding another working tool to the designer's collection of design aids. The interactive concept allows the designer to interact with the computer, making decisions that might be impractical or impossible to include in a program but allowing the computer to carry out rigorous computations. The process of designing pretensioned prestressed concrete members is organized into distinct phases. In order to produce an optimum design, various phases of the design process may have to be carried out numerous times depending on the effect of the design variables that are changed during the process. The modular interactive design system allows each module to be examined in any order and in any frequency after initial data has been input. This flexibility has been obtained by treating each module as a subroutine called by a control module. The system is designed to communicate with the designer in a conversational mode. Instructions are given to the user before requiring a response and the user has before him sufficient information to make necessary decisions. The present system can be used for the analysis-design of simple span beams and one-way slabs, with or without cantilever end spans, and of structures where the dead load is carried by simple beam action and superimposed dead and live loads are carried by continuous beam action where mild steel is provided to develop continuity over interior supports. The system is designed to be used on a minicomputer.     

Integrating member selection and structural appraisal in the design of steelwork

The paper describes a prototype computer aid for the design of steelwork based on a reappraisal of the handling of design information. Interactive computer assistance derived essentially from manual design procedures is examined and the relationship between designer and computer discussed. Characteristics of the design process are considered and the design check defined, being the basic source of information for design decisions. The computer aid operates as an executive system for handling design checks held in a library. Relevant checks are carried out sequentially for all structural parts without concurrent display of results. Compact displays of design information available at the end of this process facilitate assessment and reselection of material. The technique for displaying details of all checks carried out, including internal logic, parameters and performance indicators is described and illustrated.     

Knowledge representation of the software architecture design process based on situation calculus

Software architecture design is an interactive, complex, decision‐making process. Such a design process involves the exploration, evaluation, and composition of design alternatives. Increasingly, new computer‐aided tools are available to help designers in these complex activities. However, these tools do not know how design is actually done, in other words, by means of which design activities the final artefact was obtained. In fact, the architectural design knowledge exclusively rests in the mind of designers, and there is an urgent need to move it, as much as possible, to a computer‐supported environment that enables the capture of this type of knowledge. This contribution addresses this need by introducing a model for capturing how products under development are generated and transformed along the software architecture design process. The proposed model follows an operational perspective, where architectural design decisions are modelled by means of sequences of operations that are applied on the design products. Situation calculus is used to formally express the existence of an object in a given state of a design process. In addition, this formalism allows us expressing without ambiguities when an operation can be performed in a specific state of the design process.     

Polo problem oriented language organizer

The design process requires that engineers integrate the operation of several separate but related subtasks. The result of each subtask either creates data for the next lower level in the design, or dictates that earlier decisions be modified before proceeding further. The use of the computer as an aid to design can lead to a number of problems with respect to communication, which do not exist in the conventional design process. Problem Oriented Language (POL) supervisory systems such as ICES and the Translator Generator are available for engineers to use in communicating with the computer. However, a number of problems concerning data management and machine dependence indicate that a second look at POL supervisory systems is needed.     

Model management systems: Design for decision support

Changes in computer technology have provided decision makers with the necessary tools for the design and implementation of computerized models for decision support. These models are frequently developed to solve a specific problem for a specific user and lack the flexibility and generalizability necessary to solve unstructured, strategic problems. In addition, problems of model redundancy, inconsistency, integrity and security have prompted an increased interest in the design of model management systems (MMS) that provide for centralized management of organizational models. This paper describes the use of a framework, developed by the authors, to design an MMS for support of planning decisions within an organization. The architecture of the MMS is described in detail and the rationale for the design decisions is presented.     

基于DELPHI的CT医学图象处理系统研究及实现

医学图象处理系统(MIPS:MedicalImageProcessingSystem)作为独立于CT设备的后处理系统,主要针对现有CT设备,利用计算机对CT图象进行处理和分析。其目的是实现一个基于PC机的通用CT医学图象处理系统,满足医学图象分析要求以及医生对辅助诊断、病历报告、病历管理、影像教学等辅助功能的要求。该项研究主要针对医学CT图象处理系统软、硬件环境,改进了系统实现过程,优化系统各处理模块分析和实现。该系统基于Windows操作系统,采用面向对象并具有良好图象处理能力的Delphi语言作为RAD平台。由于对系统采用面向对象的方法进行分析、设计、开发,系统有良好的可维护性、可操作性、友好的界面。     

Multidisciplinary approach to aeroelastic studies of long-span bridges

This paper focuses on the design of long-span suspension bridges under aeroelastic constraints. Such challenging structures need to be protected against wind-induced instabilities as flutter. The authors envision that a set of scientific disciplines not currently used in bridge engineering may help along the design process and constitute a useful tool. First, the formulation of sensitivity analysis of flutter speed is described, indicating how this technique can be a guide for engineers making changes in the prototype; two examples of important bridges, as the Great Belt and Messina Strait, are used to demonstrate the capability of this approach. Then, the idea of producing computer animations to represent the aeroelastic deformation of bridges simulating virtual boundary layer wind tunnel testing is presented showing pictures of the Tacoma Narrows and Messina Bridges. Finally, the advantages of introducing distributed computing to make easier to implement the previously mentioned techniques are demonstrated. The authors have previously published papers related with sensitivity analysis in bridges or computer animations of the aeroelastic behaviour of suspension bridges. However, this is the first time that their comprehensive multidisciplinary approach is presented.     

An Integrated Framework for Representing Design History

This paper addresses the problem of representing design history. Inparticular we describe a design information system that capturesthree different aspects of design history: exploration of designalternatives, reasons for design decisions and design constraints.These three aspects of design history are basically different and itis appropriate to represent them in different ways. An integrateddesign information system (IDIS) which supports the representation of these different aspects of design history is presented. Three casestudies which have been used to test the system at various stagesduring its development are presented. One of the components of thesystem, which uses the issue based representation, was tested usingan example from process engineering. The example helped us toidentify some of the strengths and weaknesses of that component. Thisevaluation also enabled us to formulate the principle of preservingtemporal integrity. A case study is also presented which tested theability of the system to retrospectively represent design informationthat is currently recorded in a design project. This case study alsohighlighted some of the problems with existing design documentationprocedures. In the final case study the system was used off-line torecord design information as it was generated. These case studiesfound that the system could represent the required information andprovided a methodology and semi-formal representation that helpedthe designers. Due to the success of these trials the system is nowbeing used by a team of researchers in an industrial setting toprovide the next level of testing.     

A Review of Exploratory Factor Analysis Decisions and Overview of Current Practices: What We Are Doing and How Can We Improve?

Authors within the fields of cyberpsychology and human?computer interaction have demonstrated a particular interest in measurement and scale creation, and exploratory factor analysis (EFA) is an extremely important statistical method for these areas of research. Unfortunately, EFA requires several statistical and methodological decisions to which the best choices are often unclear. The current article reviews five primary decisions and provides direct suggestions for best practices. These decisions are (a) the data inspection techniques, (b) the factor analytic method, (c) the factor retention method, (d) the factor rotation method, and (e) the factor loading cutoff. Then the article reviews authors’ choices for these five EFA decisions in every relevant article within seven cyberpsychology and/or human–computer interaction journals. The results demonstrate that authors do not employ the recommended best practices for most decisions. Particularly, most authors do not inspect their data for violations of assumptions, apply inappropriate factor analytic methods, utilize outdated factor retention methods, and omit the justification for their factor rotation methods. Further, many authors omit altogether their EFA decisions. To rectify these concerns, the current article provides a step-by-step guide and checklist that authors can reference to ensure the use of recommended best practices. Together, the current article identifies concerns with current research and provides direct solutions to these concerns.     

Recognizing design decisions in programs

The authors present a characterization of design decisions that is based on the analysis of programming constructs. The characterization underlies a framework for documenting and manipulating design information to facilitate maintenance and reuse activities. They identify and describe the following categories of design decisions: composition and decomposition; encapsulation and interleaving; generalization and specialization; representation; data and procedures; and function and relation. The authors discuss how to recognize and represent design decisions     

Distributed system software design paradigm with application tocomputer networks

A paradigm for the system and software design of distributed systems is presented with application to an actual large-scale computer network involving both local area networks and a wide area network. A number of design principles are offered with particular reference to how they can be applied to the design of distributed systems. The author's major point is an explanation of how to make design decisions about distributed systems in a way which will enhance maintainability and understandability of the software and, at the same time, result in good system performance. The aim is to recognize the implications for software quality of various decisions which must be made in the process of specifying a distributed system     

The TI Advanced Scientific Computer

The authors describe some of the design decisions that determined the architecture and implementation of the Advanced Scientific Computer (ASC). They explain why certain design decisions were made, with a retrospective evaluation. They discuss the architecture, central processor, peripheral processor, circuits and packaging, and cooling. Looking back over this twenty-year project, the authors evaluate their design decisions     

Metric-based reasoning about pseudocode design in the partial metrics system

The goal of the PMS project is to produce an environment in which the intelligent online assessment of the design for large-scale ADA programming projects is provided. The focus is on the representation of knowledge about the design process for an individual module. Changes in pseudocode complexity are measured in terms of partial metrics. These metrics can take the designers inferences about the pseudocode program structure into account when assessing module complexity. Next, a model of the stepwise refinement process is given which demonstrates how pseudocode elaboration decisions can be modelled in partial metric terms. Finally, the decisions associated with each refinement step for 17 example refinements taken from the computer science literature are described using partial metrics.     

A ‘speculative pasts’ pedagogy: where speculative design meets historical thinking

ABSTRACT

This paper provides a pedagogic context for the authors’ concept of ‘Speculative Pasts,’ framed within an auto-ethnographic account of their co-taught course ‘How the Computer Became Personal.’ Blending disciplinary methodologies from historical practice and speculative and critical design, the Speculative Pasts assignment asks students to create primary documents from a hypothetical historical scenario related to an aspect of American personal computing history. This paper lays out the disciplinary contexts and development process for working across design and history disciplines, curricular organization, assignment process, and offers analysis of examples from student work. Additionally, this paper details how ‘Speculative Pasts’ offer a critique of the narrowness and problematic futurism of ‘speculative futures.’ Altogether, the authors offer this course and its primary project as a model for making history essential, rather than supplementary, to design and for leveraging practice-based production as a valued mode of historical inquiry.     

Cohesive design of personalized Web applications

Good software engineering practices, such as separating concerns and identifying patterns, simplify the critical design decisions in building personalized Web applications. The authors use the object-oriented hypermedia design method (OOHDM) for constructing customized Web applications. Incorporating well-known object-oriented design structures and techniques, OOHDM produces flexible Web application models. Designers can add personalized behavior to these models with minimal code manipulation, and reasoning over design objects yields better insight into the personalization process. Although this article casts the discussion in terms of the OOHDM primitives, the ideas presented can be easily applied to other design approaches, such as WebML     

面向工业造型设计的产品设计定位方法研究

针对传统的设计定位对市场、用户等人文因素不能量化处理,需求分析结果不能满足后续工业造型设计要求,该文综合决策论方法、设计风格的语义描述方法,在产品设计定位中融入用户偏好等心理因素,以及市场变化等动态因素,以基于市场调查的市场细分的目标市场从上向下驱动和基于用户数据库的自下而上的数据驱动方式结合的方式,使产品市场定位更为准确、实用,后续设计所需的产品描述更为完备。同时根据该方法,构建了相应的软件系统,为更系统地将设计学方法知识与计算机系统结合,创造实用的CAID系统创造了条件。     

A Course of Study in Computer Hardware Architecture

The subject of computer architecture as currently taught in most computer engineering and computer science programs is a mixture of architectural principles, organizational strategies, and implementation techniques. This blurring of the hierarchy of system levels that characterize the structure of a computer has made it very difficult for students ( and. often instructors as well) to determine what were the forces that led to the design decisions they have seen reflected in machines.     

基于有限元逆算法的压边力优化

依据理想形变理论，研究开发了冲压成形过程模拟的有限元逆算法，实现了计算机程序，并利用有限元逆算法，以变形后工件中厚度分布误差为目标函数，对冲压过程中的压边力进行优化。通过实例证明了逆算法及基于逆算法的冲压工艺参数优化方法的有效性。     

Supporting systems development by capturing deliberations duringrequirements engineering

Support for various stakeholders involved in software projects (designers, maintenance personnel, project managers and executives, end users) can be provided by capturing the history about design decisions in the early stages of the system's development life cycle in a structured manner. Much of this knowledge, which is called the process knowledge, involving the deliberation on alternative requirements and design decisions, is lost in the course of designing and changing such systems. Using an empirical study of problem-solving behavior of individual and groups of information systems professionals, a conceptual model called REMAP (representation and maintenance of process knowledge) that relates process knowledge to the objects that are created during the requirements engineering process has been developed. A prototype environment that provides assistance to the various stakeholders involved in the design and management of large systems has been implemented