The use of minicomputers in structural analysis

Methods for supplying medical personnel, especially in isolated areas, with the same sophisticated medical information and computational facilities that are available in major medical centers, were investigated. Inexpensive, readily available input/output terminals, including the pushbutton telephone, were tested with several biomedical application programs. An experimental network, consisting of several independent commercial time-sharing computers linked to user terminals through a small communication control computer, was constructed to demonstrate an efficient and flexible approach to remote computer access. The communication control computer, acting as a message handling and translating interface, allowed the use of a uniform terminal control language and common data handling conventions. By linking to the most powerful commercial time-sharing systems available, a reliable medical data processing network was established without a major investment in computer hardware or system software. This experimental work is a major part of the Medical Information Telecommunication Project in the Division of Computer Research and Technology (DCRT) at the National Institutes of Health (NIH).

: The feasibility is determined of using small computer systems (including programmable desktop calculators and minicomputers) for interactive electronic circuit simulation. Several aspects of the simulator architecture are considered: the computer language, the data word format, the computing speed, and the computer memory configuration. Interactive circuit simulation on programmable desktop calculators is investigated using simulator program BIAS-D (BASIC), written in BASIC for HP9830A desktop calculator. Analysis techniques are presented which conserve memory and advantage of the idiosyncrasies of these small computers. Interactive-mode circuit simulation and batch-mode simulation on minicomputers are compared relative to the simulator architecture and required simulation speed. The more significant speed- and memory-dependent algorithms, used in circuit simulators are compared in detail. Also compared are the execution speeds of several different minicomputer systems, including the HP2100, the PDP 11/45, and the PRIME 400. The speed and memory requirements of these minicomputers executing BIAS-D are compared to an IBM 370/168 also executing BIAS-D. A new method for computing small-signal frequency response is introduced. Because complex arithmetic is not required, this technique is particularly suited to minicomputer simulators and requires minimal additional memory when implemented in a circuit simulator with a transient analysis capability. The frequency response of both linear and nonlinear circuits can be modeled, as can that of high-Q circuits. Magnitude and phase errors of less than 1 percent and 0.5 degrees, respectively, are easily attainable.

Diffractive optical element (DOE) designs and fabrication techniques were investigated for a vertical optical interconnect architecture illustrated in Fig 1. This design provides high interconnect densities for stacked Multi Chip Module (MCM) computer architectures required in future high speed, low power, and small size computer systems. A 16 channel interconnect was demonstrated and an evaluation of greater interconnect densities is presented. Key design parameters for this effort were: ease of fabrication, compatibility of fabrication techniques with industry standards, density of interconnects, misalignment tolerance, data rates, and power consumption.

This paper is a discussion about how the Application Perspective works in practice.1 We talk about values and attitudes to system development and computer systems, and we illustrate how they have been carried out in practice by examples from the Florence project.2 The metaphors ‘utensil’ and ‘epaulet’ refer to questions about how we conceive the computer system we are to design in the system development process. Our experience is that, in the scientific community, technical challenges mean making computer systems that may be characterised as ‘epaulets’: they have technical, fancy features, but are not particularly useful. Making small, simple, but useful computer systems, more like ‘utensils’, does not give as much credit even if the development process may be just as challenging.

Deconvolution, differentiation and Fourier transformation algorithms for noise-containing data based on splines and global approximation

Structured tools and techniques were applied to the software design process of an information system for a local health care agency. The design process was based upon a hierarchical decomposition of user requirements into detail system specifications. The tools and techniques included data flow diagrams, pseudo code, a data model based upon the relational approach, and a data dictionary. Together, the design process and the tools and techniques represented an approach to bridge the gap between readily available small computer hardware and an information system that is totally integrated into the organization.

Structured tools and techniques were applied to the software design process of an information system for a local health care agency. The design process was based upon a hierarchical decomposition of user requirements into detail system specifications. The tools and techniques included data flow diagrams, pseudo code, a data model based upon the relational approach, and a data dictionary. Together, the design process and the tools and techniques represented an approach to bridge the gap between readily available small computer hardware and an information system that is totally integrated into the organization.

There are some asynchronous web-based courses available in the civil engineering technology field but to the author’s knowledge, very few courses exist in structural analysis and design. The advantages of web-based online learning include flexibility and the ability to accommodate various learning styles such as visual and auditory learners, with the visual learning style being the most common among people of college age and older. The Civil Engineering Technology program at RIT recently developed a suite of web-based courses as part of the new Certificate in Structural Design. The online courses available include Structural Analysis, Timber Design, Reinforced Concrete Design, Structural Steel Design, and Applied Mechanics. The web-based course management software used to create the e-learning environment is the Prometheus (or myCourses at RIT) platform developed at the University of Washington. This platform includes an integrated e-mail list, discussion boards, live chat rooms and an online grade book. The purpose of this paper is to present a simple and effective approach used by the author in teaching a structural analysis distance-learning course. Structural analysis is a very analytical course that involves a lot of problem solving, diagrams and figures; consequently, a combination of web-based and text-based delivery formats was used in this course. The course was divided into several modules with each module having its own Intended Learning Outcomes (ILO’s). The course modules serve as a benchmark and compass to guide and measure student learning throughout the quarter. After the completion of each module, the students were asked to provide quantitative feedback on the ILO’s for that module to the instructor, thus enabling the instructor to reinforce any concept that may not have been fully grasped by the students. Student-toinstructor interaction was maintained through the use of the discussion board in myCourses and by e-mail. The syllabus, course modules, homework assignments and other pertinent information were posted on the course web site. Weekly homework was assigned and the students submitted their homework to the instructor by fax. A proctor that was pre-approved by the RIT Office of Online Learning proctored all the tests and the final exam in this course in the student’s locality. In this paper, the author discusses the organization of the course, the course modules and ILO’s, student-to-student and student-to-instructor interactions, feedback and guidance, and students’ responses and lessons learned. Based on the student feedback and performance in this course, we conclude that the structural analysis course has been successfully delivered via a combination of web-based and text-based delivery formats.

Econometric models of the U.S. computer market have been developed to study the relationships between system price and hardware performance. Single measures of price/performance such as “Grosch's Law” are shown to be so oversimplified as to be meaningless. Multiple-regression models predicting system cost as a function of several hardware characteristics do, however, reveal a market dichotomy. On one hand there exists a stable, price predictable market for larger, general purpose computer systems. The other market is the developing one for small business computer systems, a market which is relatively unstable with low price predictability.

While small computer systems have provided us with a wide array of development and operational environments, implementation methods, and domains of the software to be developed, it has also made the software development more risky. This paper proposes a new framework for improving the software development process on small computer systems to reduce software development risks. The key idea of the proposed framework is that the solutions to the software development problems can be extracted by the project manager, with relatively low overload, from the development processes that were actually executed in order to reduce the development risks, and then be formalized and stored in a database. The formalized solutions can be used not only for process improvement, but also for devising new solutions if new problems should occur in the future. We believe that the proposed framework is capable of making up for the difficulties in implementing CMM on small computer systems, and it encourages us to apply CMM to such risky software development.

To supply data needed for a rational fatigue design of structures subject to random load there must be some appropriate testing methods which are able to reproduce a specified time history of the random variable such as load, stress, strain and stress intensity factor and also must be inexpensive to be popular ones.With a small micro computer system alone, it is very difficult to perform exact experiments considering the dynamic characters of the test system varying as the fatigue damage accumulates in the specimen. In this report, two Micro Processing Units are used to perform experiments with or without response compensation by FFT. Stationary Gaussian random processes are generated with a large computer and data are packed into special forms to be sent through TSS within a reasonable time.The developed soft and hardware are satisfactory and fatige crack growth tests under a stationary random stress intensity factor showed the effect of the compensation and indicated the possibility of a simplified and less time consuming test method without response compensation.

This paper describes the author's experiences using a low-cost system-on-a-chip (SoC) embedded computer system and a commercial real-time operating system (RTOS) in the laboratory component of an undergraduate embedded system design class. The target hardware is a small low-cost X86 SoC computer system that has a wide range of I/O features. For software development, a popular commercial hard RTOS is used that has been designed for use in embedded devices. This course covers both hardware and software topics in embedded systems, and the course culminates in a final team-based design project. A full set of course materials including a textbook with laboratory tutorials, instructor slides, and code examples has been developed and is available online in electronic form.

The structural design and analysis of a cryogen-free open superconducting magnet for interventional MRI applications is presented. The magnet assembly consisted of two identical halves connected together by four posts. The magnet separation allows a surgeon access to the patient within the field-of-view of the imaging system. Each half of the assembly consisted of three superconducting coils, a stainless steel bobbin, a copper thermal ring, and three overwrap rings. The suspension components of the magnet consisted of eight radial straps and eight axial rods. A structural analysis was carried out that considered the differential thermal contraction caused by the cooldown to the magnet cryogenic operating temperature, and the electromagnetic forces on the coils when the magnet is energized at the design current value. The results are compared to the equivalent stresses caused by a simulation of a quench that was initiated at the inner diameter of one of the superconducting coils. The post-quench thermal transient analysis predicted a nonuniform 3-D temperature field in the range of 10 to 178 K and asymmetric electromagnetic forces on the superconducting coils. The three dimensional structural model of the assembly was developed in ANSYS.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The structural analysis and design of the Heidrun tension leg platform presented many technical Challenge a that had to be overcome in a fast and efficient manner to meet the demands of a very tight schedule. Some are inherent in the nature of a compliant structure such as a TLP with its complicated interaction between the structure, the mooring system and the environment and the importance of proper weight and at ability control during the different phase a of construction and operation. However, many other a were unique to the Heidrun platform. The Heidrun hull is the first large offshore structure built entirely of high strength lightweight aggregate (LWA) concrete. The topside modules form an integral component of the structural system of the platform. The interface between the steel topside modules and the concrete hull proved to be a very complex engineering task requiring very detailed analyses, tight fabrication and installation tolerances as well as testing of a number of key components. Ringing loads were included in the structural design of the platform for the first time in an offshore structure. The transportation of the large topside modules, mounted transversely on barges, and their mating to the hull was unique. The reserve capacity built into the design to provide additional safety in the critical components of the structure. The paper presents an overview of the multitude of challenges encountered during the detail design of the platform. Introduction The Heidrun TLP introduced several structural innovations not seen previously on any offshore platform. Examples of these include the concrete Module Support Beams (MSBS) as a main structural member of the platform and for supporting the topside modules, unique solutions for connecting the topside modules to the substructure, exclusive use of high strength LWA concrete in the construction of the hull, design and fabrication of very large diameter columns, and design of the platform for the structural effects of ringing. This paper gives an overview of the structural analysis and design activities required in connection with the development of the Heidrun TLP and concentrates on design aspects which are novel or required more extensive consideration due to the nature of the TLP configuration or construction method. A short description of the platform is provided followed by the most significant aspects of thehydrodynamic and structural analyses. Special analyses and some of the unique design considerations associated with the hull and topsides design are presented. For completeness brief descriptions are given of the construction sequence of the hull, the foundations and the independent design verification performed for the structural design.

An on-line system to analyze cardiac arrhythmias was developed by the use of a small scale digital computer. In this system, the electrocardiographic signals were fed into the computer, being adjusted within the input range by a buffer amplifier. The analog signals of each electrocardiogram were converted to the digital form at the rate of 1, 000 per second for 20 seconds by the analog-to-digital converter insatlled in the computer. Thus, the digitized electrocardiogram was processed by the diagnostic program. The computation time for the parameter measurements and the interpretation of an electrocardiogram by this system was about 15 seconds. The automated systems of this type would serve as a diagnostic aid for physicians in the routine electrocardiographic interpretation and the mass screening of heart diseases.