Interactive techniques with graphical output for bridge analyses

This paper considers the implementation of algorithms, in the form of a programming system, for the finite element modeling and analysis of bridges. Also described are the linkages between the modeling and analysis phases as controlled by the user. The nature and type of commands necessary are subsequently presented and discussed. Finally, an example of a single cell box girder bridge with graphical results for the modeling and analysis phases is presented.The modeling system, which communicates with the user through a problem oriented language, allows the user to: define the parameters that characterize the structure; modify an already discretized structure; and obtain graphical or line printer displays of various structural components such as structure geometry, cross section geometry, and various results of analysis such as deflections, reactions and stress resultants. The modeling system automatically performs the following: discretization of the structure; generation of elements and assignment of attributes; and node numbering and location.     

Simulation economic evaluation: An expert system for workshop simulation

The job-shop scheduling optimization problem is an example application of Operations Research and Simulation models. This problem has been extensively researched and different models have been presented in the literature for solving different situations. SLAM (Simulation Language for Alternative Modeling) 4 is a simulation language that can be used to analyze this problem and is now available for microcomputers. However, SLAM, similar to the other specialized simulation languages, requires sophisticated analysts to transcribe the problem in SLAM commands.

This paper presents an expert system that can generate SLAM commands for a job-shop planning application where a user with no SLAM or Simulation knowledge can interact directly with a micro-computer to run the SLAM application. The expert system is in the form of a user-friendly conversational program which automatically translates the problem parameters into SLAM commands, executes the SLAM program, and provides an unsophisticated Simulation user with the analysis results.     

A user oriented computer language for the retrieval and manipulation of energy data

The need for timely energy data for testing the implications of decisions on fiscal, economic and/or regulatory proposals was brought into sharp focus by the Arab Oil embargo of 1973 and has been intensified by the continuing shortage of critical energy resources. To satisfy this need, a research program was begun at the University of Houston to develop an energy data bank and information retrieval system suitable for use by the unsophisticated computer user. The results of this research program include a simple to use, conversational language which allows the user to access a time series energy data bank for the data of interest, to manipulate the data, and to document the data in both tabular and graphical form. The conversational user language consists of a retrieve command, twenty-two analysis commands, and two documentation commands. The command structure uses simple language and syntax which are suggestive of the operation requested. In addition, the language is capable of simple extensions, making it very responsive to the user's needs. The object of this paper is to describe the user language, its operational structure, and to examplify the ease of its use.     

The use of punched cards in US libraries and documentation centers,1936-1965

Librarians, particularly those in traditional academic and public libraries, were slow to take advantage of punched cards. In contrast, special librarians and documentalists, with their small systems and focus on retrieving information for users, readily adopted punched cards. The results were dramatic: improved ability to index scientific and technical information and better user service. The paper presents a history of the use of punched cards in US libraries     

Finite element programs based on general programming systems

This article describes the advantages and inconveniences with a finite element programming system, i.e. blocks of routines already thoroughly tested, which has to be built together by a programmer to a finite element program. This program may be a tailor-made program to fit a special problem or a general purpose finite element program.

The programming system used as an example in this article consists of

1. *NORSAM—finite element programming system

2. *DASA — pre- and postprocessors

3. *ELLIB—element library

Together they form a complete set of subroutines from datageneration through the necessary routines for matrix manipulation to presentation of results, including the multilevel superelement technique.

Reference to finite element programs applying the programming system concept, is given at the end of the article. Among others, programs for buckling, elasto-plastic analysis of 3-dimensional membranes and solids, nonlinear pipeline problems, acoustic field problems and transient heat conduction in solids are developed. The multilevel superelement technique has been applied in several of these application programs.

The concept of the programming system gives undoubtedly a large saving of time and resources and has proved to be more reliable than conventional methods when developing finite element programs.     

Designing screens for people to use easily

The use of interactive computer systems is expanding rapidly. In many applications users can communicate directly with computer-based systems through an interactive dialogue at a display terminal. However, this direct form of communication has created problems. Whereas early users of on-line systems were skilled computer professionals, today's users may have little or no training in computer technology. How then does this group communicate effectively with a computer systems?

The answer is that many users communicate only with considerable difficulty. The result is that the effectiveness of many systems is very much less than expected. The reason for this is simple: these systems are not very good at communicating with their users.

The most common communications bridge between a person and a computer system is a display screen. A well-designed screen format can enhance user productivity, eliminate or reduce user input errors, and promote end user satisfaction. A poorly designed screen has the opposite effect: it will decrease human processing speed, provoke user mistakes, and complicate computer operations.

Screen design requires the same care as designing the overall application. It employs the same techniques as planning and preparing good user documents. Screens, like documents, must be easy to understand and easy to use. To achieve these objectives, screen designers must make good choices regarding three ease-of-use parameters: format; screen content and layout; and style. This paper describes how standards may be established for each of these parameters in a proposed application or system. Futher, an interactive tutorial computer program has been developed (using Bricklin's DEMO program) which may be used to illustrate the application of these standards.     

Finite element analysis of static and dynamic stresses around suddenly punched holes in plates and shells

The magnitude and distribution of stresses around suddenly punched holes in initially stressed plates and shells is of interest to insure that cracks will not precipitate from stress concentration. This problem is of practical interest to pressure vessel designers to preclude catastrophic failure when holes are punched in vessels to release gas. This paper presents a finite element analysis of several problems investigating static and dynamic stress fields around suddenly punched circular holes.

The first problem deals with the investigation of the radial and tangential stress fields in the vicinity of a suddenly punched hole in a stretched, elastic, isotropic plate subjected to an initial hydrostatic stress field. The wave propagation from a punched hole in the plate under a hydrostatic state of stress was solved analytically, using transform techniques, by Miklowitz; the finite element analysis of this problem presented in this paper confirms the analytical solution. Two grid meshes were investigated and results are presented to show the effect of grid mesh on solution accuracy and the power of finite element techniques for solving stress unloading problems. A formula for determining integration step size is found to be a function of the minimum element length and the wave propagation velocity. A similar investigation into the stress effects around a suddenly punched hole in the plate subjected to an initial uniaxial state of stress was also carried out as a prerequisite for the final problem studied.

The last problem is an anisotropic composite shell of varying thickness under an initial stress field due to internal pressure. The static and dynamic stress fields are computed from an unloading wave that radiates outward from a reinforced circular hole that is cut in the shell in 20 μs. A finite-element model of the shell is developed using quadrilateral and triangular plate elements and both in-plane and bending stiffness is included in the analysis as is nonlinear differential stiffening incorporated into the analysis as a single step approximation. Both bending and in-plane waves radiate outward from the cut hole and the dynamic stresses around the hole edge are computed for both unloading waves. The effects of the unloading waves are temporally spaced due to different wave velocities.

The paper demonstrates that fast response stress problems are readily amenable to finite-element analysis. For holes other than circular, the power of finite-element methods is apparent since these shapes lead to mathematically intractable problems if closed form solutions are attempted.     

A software development system based on a macroprocessor

In this paper a system for software development is described. This system consists of a general-purpose macroprocessor and a set of service programs. The macroprocessor has been planned to work in a conversational environment and to this purpose a set of utilities has been inserted to aid the editing and the debugging of the macrodefinitions. Indeed the system allows the user to select, by means of commands, the flow of the operations to be executed and to choose when and how any program has to be expanded. The macroprocessor is easy to use and it is suitable to generate codes for both high-level languages and assembler languages.     

Simulation model for a vanpooling system

Vanpooling programs have recently generated interest as a mode of transporting people to and from work. The vanpooling service can help in decreasing transportation cost, solving parking problems, easing traffic congestion, reducing air pollution, etc.

The implementation and success of a vanpooling program usually depends on the service schedule and economic considerations. Costs have been worked out such that each monthly payment covers all costs of acquiring, maintaining, operating, and replacement of the vans.

This paper will discuss the design, modeling, and simulation of a vanpooling service system. The paper will cover the simulation program that was developed, and an application of this model.

The study demonstrated that the cost per participant is approximately half the cost that is involved in private transportation.     

Interactive multiple objective linear programming system implemented on a microcomputer

Linear programming is one of the most widely used Operations Research/Management Science techniques. Recently, multiple objective decision making has been well established as a practical approach to seek a satisfactory solution to a decision making problem. Much attention has been focused on a microcomputer as an economical management tool.

In this paper we propose an interactive goal attainment method using the eigenvector algorithm for solving a multiple objective linear programming problem interactively on microcomputers. In the software package Micro-LPS based on the method proposed, we design a conversational and user-friendly system in which the user commands are involved.     

Show me: automatic presentation for visual analysis

This paper describes Show Me, an integrated set of user interface commands and defaults that incorporate automatic presentation into a commercial visual analysis system called Tableau. A key aspect of Tableau is VizQL, a language for specifying views, which is used by Show Me to extend automatic presentation to the generation of tables of views (commonly called small multiple displays). A key research issue for the commercial application of automatic presentation is the user experience, which must support the flow of visual analysis. User experience has not been the focus of previous research on automatic presentation. The Show Me user experience includes the automatic selection of mark types, a command to add a single field to a view, and a pair of commands to build views for multiple fields. Although the use of these defaults and commands is optional, user interface logs indicate that Show Me is used by commercial users.     

IMMIView: a multi-user solution for design review in real-time

IMMIView is an interactive system that relies on multiple modalities and multi-user interaction to support collaborative design review. It was designed to offer natural interaction in visualization setups such as large-scale displays, head mounted displays or TabletPC computers. To support architectural design, our system provides content creation and manipulation, 3D scene navigation and annotations. Users can interact with the system using laser pointers, speech commands, body gestures and mobile devices. In this paper, we describe how we design a system to answer architectural user requirements. In particular, our system takes advantage of multiple modalities to provide a natural interaction for design review. We also propose a new graphical user interface adapted to architectural user tasks, such as navigation or annotations. The interface relies on a novel stroke-based interaction supported by simple laser pointers as input devices for large-scale displays. Furthermore, input devices such as speech and body tracking allow IMMIView to support multiple users. Moreover, they allow each user to select different modalities according to their preference and modality adequacy for the user task. We present a multi-modal fusion system developed to support multi-modal commands on a collaborative, co-located, environment, i.e. with two or more users interacting at the same time, on the same system. The multi-modal fusion system listens to inputs from all the IMMIView modules in order to model user actions and issue commands. The multiple modalities are fused based on a simple rule-based sub-module developed in IMMIView and presented in this paper. User evaluation performed over IMMIView is presented. The results show that users feel comfortable with the system and suggest that users prefer the multi-modal approach to more conventional interactions, such as mouse and menus, for the architectural tasks presented.     

Increasing usability of voice activated dialing systems

Research suggests that cellular phone use while driving increases the risk of an auto accident by a factor of 4. Additionally, it has yet to be shown that hands-free phones (such as those which use voice-activated dialing systems (VADS)) provide any added safety benefit over manual phones. Since it has been shown that driving performance is degraded during complex conversations especially under demanding driving conditions it makes sense to design the VADS interface to be as intuitive and simple to navigate as possible in order to reduce the risk of an accident. This paper presents the results of an investigation of a commercially available voice-activated dialing system under simulated driving conditions and provides recommendations for improvement of its call flows and user-interface design. Considering the call flow findings, we conclude that the voice phone book metaphor provides an adequate mental map which helps users navigate the menu hierarchy with some minor exceptions. With regard to the user interface design findings, we conclude that any VADS could be improved by following the principles of conversational speech such as avoiding repetition and being flexible in its handling of interruptions.

Relevance to industry

The design of a VADS interface should be as intuitive and simple to navigate as possible. This study suggests recommendations to improve both the call flow structure and user interface design of a commercially available VADS.     

Parallel on-line parsing in constant time per word

An on-line parser processes each word as soon as it is typed by the user, without waiting for the end of the sentence. Thus, in an interactive system, a sentence will be parsed almost immediately after the last word has been presented.

The complexity of an on-line parser is determined by the resources needed for the analysis of a single word, as it is assumed that previous words have been processed already. Sequential parsing algorithms like CYK or Earley need O(n²) time for the nth word. A parallel implementation in O(n) time on O(n) processors is straightforward. In this paper a novel parallel on-line parser is presented that needs O(1) time on O(n²) processors.     

Expert systems can do job shop scheduling: An exploration and a proposal

We develop a concept for an expert system for job shop scheduling. The system uses heuristics for setting priorities and establishing the sequencing during the early part of the schedule.

The program was used to test several example problems. The schedules developed were very good and near or at optimal.

The program uses an expert system shell and a list processing machine. The processing time runs from about 3 to 6 minutes.     

Using CAD/CAM for three-dimensional linear programming models

A software package has been developed for the Intergraph CAD/CAM system to illustrate three-dimensional linear programming models. The software, called LPVAX, allows a user to enter a linear programming model with three variables and receive a complete solution including sensitivity analysis. The use may then, by menu commands, enter the solution into a graphics file for the CAD/CAM system to convert into graphics displays. The user can display all of the constraints and the objective function in a three-dimensional graph. The solution solid can be viewed and rotated continuously, a key technique for user understanding of the feasible solution space. Constraints can be removed from or added to the display singly or in groups so that any number of the constraints may be displayed immediately. The system is menu-driven for ease of use.     

CIMBASE中分布式C预编译程序的实现研究

ＣＩＭＢＡＳＥ是为计算机集成制造系统而设计的一个异构分布式数据库管理系统．ＣＩＭＢＡＳＥ的重要用户接口之一是它的Ｃ预编译程序．它允许用户在Ｃ里访问远程数据库，是用户开发计算机集成制造系统的重要编程接口．在这篇论文里，我们先介绍它的主要功能，而后集中讨论有关它的实现技术．特别是必要的通信命令设计，主程序、代理程序的工作模式、结构及其生成，以及与之相关的某些算法．     

From Neweul to Neweul-M<Superscript>2</Superscript>: symbolical equations of motion for multibody system analysis and synthesis

The state-of-the-art for deriving symbolical equations of motion for multibody systems is reviewed. The fundamentals of formalisms based on Newton–Euler equations are presented and the recent development of a research software called Neweul-M² is highlighted. The modeling approach with commands and a graphical user interface are discussed as well as system analysis options, control design by export to Matlab/Simulink, and parameter optimization for system synthesis. The alternatives within the program using symbolic and numeric approaches are emphasized. A double pendulum is used to explain the program features and a vehicle benchmark model is presented as an example. Advanced applications include closed kinematic loops and flexible bodies.