Essentials of computing systems

Computers were invented to “compute“, i.e., to solve all sort of mathematical problems. A computer system contains hardware and systems software that work together to run software applications. The underlying concepts that support the construction of a computer are relatively stable. In fact, (almost) all computer systems have a similar organization, i.e., their hardware and software components are arranged in hierarchical layers (or levels) and perform similar functions. This book is written for programmers and software engineers who want to understand how the components of a computer work and how they affect the correctness and performance of their programs.Publishe

Openstage: a low-cost motorized microscope stage with sub-micron positioning accuracy

Recent progress in intracellular calcium sensors and other fluorophores has promoted the widespread adoption of functional optical imaging in the life sciences. Home-built multiphoton microscopes are easy to build, highly customizable, and cost effective. For many imaging applications a 3-axis motorized stage is critical, but commercially available motorization hardware (motorized translators, controller boxes, etc) are often very expensive. Furthermore, the firmware on commercial motor controllers cannot easily be altered and is not usually designed with a microscope stage in mind. Here we describe an open-source motorization solution that is simple to construct, yet far cheaper and more customizable than commercial offerings. The cost of the controller and motorization hardware are under $1000. Hardware costs are kept low by replacing linear actuators with high quality stepper motors. Electronics are assembled from commonly available hobby components, which are easy to work with. Here we describe assembly of the system and quantify the positioning accuracy of all three axes. We obtain positioning repeatability of the order of [Formula: see text] in X/Y and [Formula: see text] in Z. A hand-held control-pad allows the user to direct stage motion precisely over a wide range of speeds ([Formula: see text] to [Formula: see text]), rapidly store and return to different locations, and execute "jumps" of a fixed size. In addition, the system can be controlled from a PC serial port. Our "OpenStage" controller is sufficiently flexible that it could be used to drive other devices, such as micro-manipulators, with minimal modifications

Teaching lower level computer science courses via virtual classroom and video : course reports by faculty

New Jersey Institute of Technology is the grateful recipient of a generous grant from the Alfred P. Sloan Foundation which has enabled it to explore the use of asynchronous learning networks to create and deliver an entire undergraduate degree program in computer and information science. Each of these courses uses some amount of lecture-type material delivered via videotape. These materials are usually available to students in three different ways: by viewing broadcasts on a New Jersey cable station, by renting the set of videotapes, or by viewing in a special room in the library. Videotapes for distance learning are not new and are not, in themselves, a very effective means of delivery. The innovative part of this project is the Virtual Classroom™ which is a specially tailored set of features embedded in New Jersey Institute of Technology\u27s computer conferencing system, EIES (Electronic Information Exchange System). This makes possible a rich interchange and collaboration among students and faculty as they discuss and work through the problems and concepts in a course. As of the spring of 1995, both the B.A.I.S and the B.S.C.S. are available to distance and oncampus students. Teaching in a Virtual Classroom mixed with other media (such as video or CD ROM) is not simple however. The purpose of the enclosed descriptions of experiences by faculty members is to familiarize prospective teachers using this media mix in the future with both some ideas for how to organize their online activities, and knowledge of problems that have been encountered. The faculty members were given a suggested outline of topics to include in their reports, but otherwise were free to include whatever they thought would be of most use to other faculty members in the future, teaching the same or similar courses. Those who are interested in learning more about teaching and learning in ALN environments are referred to two book-length treatments: Starr Roxanne Hiltz, The Virtual Classroom: Learning Without Limits via Computer Networks (Ablex, Norwood NJ, 1994); and Linda Harasim, Starr Roxanne Hiltz, Lucio Teles and Murray Turoff, Learning Networks: A Field Guide to Teaching and Learning Online (MIT Press, 1995

Congruent Weak Conformance

This research addresses the problem of verifying implementations against specifications through an innovative logic approach. Congruent weak conformance, a formal relationship between agents and specifications, has been developed and proven to be a congruent partial order. This property arises from a set of relations called weak conformations. The largest, called weak conformance, is analogous to Milner\u27s observational equivalence. Weak conformance is not an equivalence, however, but rather an ordering relation among processes. Weak conformance allows behaviors in the implementation that are unreachable in the specification. Furthermore, it exploits output concurrencies and allows interleaving of extraneous output actions in the implementation. Finally, reasonable restrictions in CCS syntax strengthen weak conformance to a congruence, called congruent weak conformance. At present, congruent weak conformance is the best known formal relation for verifying implementations against specifications. This precongruence derives maximal flexibility and embodies all weaknesses in input, output, and no-connect signals while retaining a fully replaceable conformance to the specification. Congruent weak conformance has additional utility in verifying transformations between systems of incompatible semantics. This dissertation describes a hypothetical translator from the informal simulation semantics of VHDL to the bisimulation semantics of CCS. A second translator is described from VHDL to a broadcast-communication version of CCS. By showing that they preserve congruent weak conformance, both translators are verified

Standardized development of computer software. Part 2: Standards

This monograph contains standards for software development and engineering. The book sets forth rules for design, specification, coding, testing, documentation, and quality assurance audits of software; it also contains detailed outlines for the documentation to be produced

Feasibility study of an Integrated Program for Aerospace vehicle Design (IPAD). Volume 4: IPAD system design

The computing system design of IPAD is described and the requirements which form the basis for the system design are discussed. The system is presented in terms of a functional design description and technical design specifications. The functional design specifications give the detailed description of the system design using top-down structured programming methodology. Human behavioral characteristics, which specify the system design at the user interface, security considerations, and standards for system design, implementation, and maintenance are also part of the technical design specifications. Detailed specifications of the two most common computing system types in use by the major aerospace companies which could support the IPAD system design are presented. The report of a study to investigate migration of IPAD software between the two candidate 3rd generation host computing systems and from these systems to a 4th generation system is included

An 8-Bit Analog-to-Digital Converter for Battery Operated Wireless Sensor Nodes

Wireless sensing networks (WSNs) collect analog information transduced into the form of a voltage or current. This data is typically converted into a digital representation of the value and transmitted wirelessly using various modulation techniques. As the available power and size is limited for wireless sensor nodes in many applications, a medium resolution Analog-to-Digital Converter (ADC) is proposed to convert a sensed voltage with moderate speeds to lower power consumption. Specifications also include a rail-to-rail input range and minimized errors associated with offset, gain, differential nonlinearity, and integral nonlinearity. To achieve these specifications, an 8-bit successive approximation register ADC is developed which has a conversion time of nine clock cycles. This ADC features a charge scaling array included to achieve minimized power consumption and area by reducing unit capacitance in the digital-to-analog converter. Furthermore, a latched comparator provides fast decisions utilizing positive feedback. The ADC was designed and simulated using Cadence Virtuoso with parasitic extraction over expected operating temperature range of 0 – 85°C. The design was fabricated using TSMC’s 65 nanometer RF GP process and tested on a printed circuit board to verify design specifications. The measured results for the device show an offset and gain error of +7 LSB and 31.1 LSB, respectively, and a DNL range of -0.9 LSB to +0.8 LSB and an INL range of approximately -4.6 LSB to +12 LSB. The INL is much improved in regard to the application of the temperature sensor. The INL for this region of interest is from -3.5 LSB to +2.8 LSB

A rationale and design of a microcomputer system for schools and colleges

Imperial Users onl

Rapid prototyping using a precision robotic manipulator

A rapid prototyping system using a precision robotic manipulator has been developed. The system is comprised of a latest personal computer (Pentium II, 300 MHz, 128 MB RAM and 5 GB hard disk capacity), interfacing system (PS-23 indexer, KS-drives and servomotors), a four degrees of freedom precision manipulator and a ball nosed end milling equipment. The hardware is integrated with the AutoSurf (CAD software), which is used in designing engineering models, section cut the surface models and changing graphic file into DXF files (neutral format files). The AutoLISP (AutoSurf programming language) has been used to simulate the additive prototyping process. The hardware is also linked with the self-developed CAM programs for data processing and motion control. With the above hardware and software configuration, subtractive prototyping models have been produced successfully. Simple additive prototyping process was also simulated graphically in AutoSurf environment. The CAM programs were also tested to be fine with the additive prototyping models’ data files. Generally, the rapid prototyping system using the precision robotic manipulator has the advantage of being cheaper, effective, time and space saving, with dual purposes (subtractive and additive processes) and it is an all in one system