PC Compatible Machines Research Articles

Electron Diffraction Based Analysis of Phase Fractions and Texture in Nanocrystalline Thin Films, Part II: Implementation

This series of articles describes a method that performs (semi)quantitative phase analysis for nanocrystalline transmission electron microscope samples from selected area electron diffraction (SAED) patterns. Volume fractions of phases and their textures are obtained separately in the method. First, the two-dimensional SAED pattern is converted into an X-ray diffraction-like one-dimensional distribution. Volume fractions of the nanocrystalline components are determined by fitting the spectral components, calculated for the previously identified phases with a priori known structures. Blackman correction is also applied to take into account dynamic effects for medium grain sizes. Peak shapes and experimental parameters (camera length, etc.) are refined during the fitting iterations. Parameter space is explored with the help of the Downhill-SIMPLEX algorithm. Part I presented the principles, while Part II now elaborates current implementation, and Part III will demonstrate its usage by examples. The method is implemented in a computer program that runs under the Windows operating system on IBM PC compatible machines.

MASSHA– a graphics system for rigid-body modelling of macromolecular complexes against solution scattering data

A program,MASSHA, for three-dimensional rendering and rigid-body refinement is presented. The program allows display and manipulation of high-resolution atomic structures and low-resolution models represented as smooth envelopes or ensembles of beads.MASSHAis coupled with a computational module to align structural models of different nature and resolution automatically. The main feature is the possibility for rigid-body refinement of the quaternary structure of macromolecular complexes. If high- or low-resolution models of individual subunits are available, the complex can be constructed on the computer display and refined to fit the experimental solution scattering data.MASSHAprovides both interactive and automated refinement modes to position subunits in a heterodimeric complex (general case) and in a homodimeric complex with a twofold symmetry axis. Examples of application of the program (running on IBM PC compatible machines under Windows 9x/NT/2000) are given.

A stable vision system for moving vehicles

This paper presents a novel approach to stabilize the output of video camera installed on a moving vehicle in a rugged environment. A 2.5D interframe motion model is proposed so that the stabilization system can perform in situations where significant depth changes are present and the camera has both rotation and translation. Inertial motion filtering is proposed in order to eliminate the vibration of the video sequences with enhanced perceptual properties. The implementation of this new approach integrates four modules: pyramid-based motion detection, motion identification and 2.5D motion parameter estimation, inertial motion filtering, and affine-based motion compensation. The stabilization system can smooth unwanted vibrations or shakes of video sequences and achieve real-time speed. We test the system on IBM PC compatible machines and the experimental results show that our algorithm outperforms many algorithms which require parallel pipeline image processing machines.

A real-time interface for a formant speech synthesizer

This paper describes a multi-parametric user interface based around the Musical Instrument Digital Interface (MIDI) Creator system developed at York which provides MIDI data in response to changing pressures on five strain gauge sensors to control the fundamental frequency, first three formants and the overall amplitude of synthesized speech. Vocal synthesis is achieved by means of a freely available time domain formant synthesis system running on a standard PC compatible machine. The result is a novel hand-controlled speech synthesizer which is not command:phoneme based, but is rather more like a continually controlled musical instrument where the speech sounds are shaped in real-time.

A Linux kernel module implementation of restricted Ada tasking

An Ada tasking kernel is implemented as a layer beneath the Linux operating system on a PC-compatible machine. This implementation is derived from Yodaiken's Real-Time Linux kernel, with new scheduling and synchronization primitives introduced specifically to support the GNAT Ada runtime system. Primitive operations for real-time Ada tasks are directly implemented on top of the underlying hardware in the form of a loadable Linux kernel module. This design not only reduces execution overhead and improves control over execution timing for tasks, but also opens the door for a simple restricted-tasking runtime system that could be certified for safety-critical applications.

Automatic adaptive finite element mesh generation over arbitrary two-dimensional domain using advancing front technique

The basic principles for the generation of adaptive finite element meshes over arbitrary two-dimensional domains using the advancing front technique are described. Methods to generate triangular and quadrilateral meshes are also presented. In addition to the description of the mesh generation algorithms, implementation details concerning both the speed and memory requirement are given. Mesh generation examples demonstrate that the proposed mesh generator is capable of discretizing the problem domain into a well-graded, high quality adaptive finite element mesh with element sizes compatible with the user specification. The whole automatic mesh generation program can be run on an IBM PC compatible machine and meshes with up to 9000 elements can be generated within a practical time limit.

A comparison between singing pitching strategies of 8 to 11 year olds and trained adult singers

A microcomputer-based system known as SINGAD (SINGing Assessment and Development) is described which enables note pitching ability to be assessed and developed. Versions of the SINGAD system currently exist for the BBC and Atari range of computers and work is currently in progress on a version for PC compatible machines. This paper describes results from a SINGAD experiment in which the pitching abilities were assessed of 175 children aged between 8 and 11 years inclusive attending a York primary school. The assessment was made against computer generated musically meaningful three note patterns from the major tonic triad of Bb 3. Each child responded to 15 such three note stimuli. A marked contrast between the pitching abilities of boys and girls is observed and discussed in relation to SINGAD assessment data gathered from a group of trained adult singers.

Computer vision based morphometric characterization of neural cells

This article reports on the application of computer vision techniques, implemented on an IBM PC-compatible machine, as a means of obtaining morphometric characterization of neural cells. The features considered include projection polar histograms, orientation polar histograms, and the determination of the convex hull of dendritic (or axonal) arborizations. As will be discussed in this work, the Hough transformation technique has proven to be of great help for the determination of all the above-mentioned parameters. Two actual application examples respective to the analysis of retinal ganglion cells are also presented and discussed.

PBM: a software package to create, display and manipulate interactively models of small molecules and proteins on IBM-compatible PCs.

The PBM package was developed to create, display and conveniently manipulate protein and small molecule structures on IBM-compatible microcomputers. It consists of four modules: CREATE, SPHERE, RIBBON and CONVERT. CREATE includes commands to create or alter ('mutate') the primary and subsequently the tertiary structure of a given peptide or protein by defining phi and psi angles of residues at will, options to add, delete or alter atoms in a structure, utilities to choose easily between the most common rotamers of amino acid residue sidechains and options to analyse in various ways a protein conformation. SPHERE provides for an interactive manipulation of structures containing up to 2700 atoms which can belong up to six different molecules. All manipulations can be made with the use of an ordinary mouse, by choosing from a variety of pull-down menus. Three types of models can be implemented to display molecules on the computer screen or the plotter: skeletal, solid space-filling and wireframe space-filling models. RIBBON creates ribbon models of proteins and allows for a limited variety of interactive manipulations. CONVERT is a file converter, which is capable of converting files of atom coordinates of literally any format to Brookhaven Data Bank format files. The package produces very good results for protein molecules of reasonable sizes, both in terms of graphics quality and speed of operations, on an 80486 IBM PC-compatible machine equipped with a 1 MByte VGA display card and a colour VGA monitor, which is a recommended configuration.

An expert system using an exchange heuristic for the resource-constrained scheduling problem

In this paper, we discuss the development and implementation of an expert system for the resource-constrained scheduling problem. The objective of the system is to minimize the makespan (or duration of a project). This approach can accommodate up to 400 operations (activities) and 50 different resources. The knowledge contained in the expert system is based upon an exchange heuristic algorithm that has been applied succesfully to various resource-constrained scheduling problems and has been shown to be a very general and efficient search method for large-sized problems. The exchange heuristic takes an initial schedule and improves upon it via exchanging and rearranging operations, while continually maintaining feasibility. In this system, a forward chaining strategy is used as the inference process. These production system language OPS83 with external C-language links is utilized as the system development tool. In order to evaluate the performance of the expert system, we compared it with an earlier heuristic programming version and found that superior computation performance and enhanced software maintenance were achieved. A number of large-sized problems have been tested on this system, and the results have shown that the makespans were reduced by 10–16 percent compared to initial schedules. Advanced programming techniques were utilized to reduce computer memory requirements and to increase the search speed. Therefore, the system can deal with large-sized problems on PC-compatible machines (with 640KB RAM or more), running MS-DOS, with short CPU execution times.

The core guided discovery approach to acquiring programming skills

The CORE approach is a design method for constructing learning environments based on principles derived from studies of language and cognitive development. The method has been applied so far to the design of learning environments for acquiring programming skills. This approach is in direct contrast to traditional didactic, rule based approaches where instructions are first given, and practice to implement these instructions follows. The CORE approach, by contrast, engages the student as an active problem solver from the very beginning. The central principle is to present the user not with abstract rules to be learned but with concrete examples to be understood. These key examples are followed by a series of questions and feedback answers which allow the learner to clarify and extend their understanding. The other two major features of the method are to set a clear context for each learning session, and to get the learners to express and reflect on their knowledge at the end of each session. A computer aided learning environment for Pascal has been developed for IBM PC compatible machines. This was used with groups of students for an extended period of time. The students' assessment of the CORE Pascal learning system as an effective and enjoyable learning environment was very positive.

Real time trigonometric function evaluation

The paper considers a microcomputer implementation of an algorithm for generating sine and cosine functions at high speed and with moderate precision. In essence, the trigonometric functions are derived by interpolating between function values held in a look-up table: the method uses simple integer arithmetic and it does not require the services of an arithmetic coprocessor device. From a detailed examination of interpolation errors, a design rule is established for determining the minimum size of table for a particular function magnitude, and for realizing errors below 1/2 LSB. For those applications requiring increased accuracy, a modification to the basic interpolation algorithm is offered to allow estimation and cancellation of the interpolation errors. As an illustration of the design method, a subroutine that produces sine and cosine function values to 13-bit 2's complement precision on an 80286 microprocessor system is listed. Testing the subroutine's accuracy confirms the validity of the error analysis, the design rule and the interpolation error correcting scheme. Further tests, performed on a range of IBM PC compatible machines, show that the subroutine calculates the function faster than one that relies on the PC's attendant coprocessor device.

MOMENT: software for analysis and display of amphiphilic regions in proteins.

MOMENT is a 53 kbyte program written in Borland TurboPascal with Borland Turbo Graphics, which will run on IBM PC-compatible machines. The program reads protein sequence files and calculates the hydrophobic moment of user-defined segments. The values produced can be displayed in the form of a scan through the sequence, as vector diagrams and helical wheels, as plots of hydrophobic moment versus hydrophobicity, or as hydrophobic moment as a function of angle.

Principles and Performance of a PC-Based Program for Simulation of Grazing Incidence X-Ray Reflectivity Profiles

ABSTRACTWe describe PC- based software which calculates grazing incidence X-ray reflectivity profiles from model thin film structures, including interface grading. We discuss the mathematical principles of the model and benchmark tests for speed of operation on two PC compatible machines are presented. Curvature of the specimen results in selective loss of fringe visibility at low scattering vectors and is treated rigorously. We discuss the treatment of roughness and use a generalized formula that is valid at large and small values of the reflectivity; its effects are illustrated using the program.

Managing Software Projects Designed Using a Graphic Language

Experience with development of engine control software using a graphic design language is presented. The Bendix integrated software development environment centers around an internally developed graphic design language, the Bendix Orthogonal Graphics System (BOGS). BOGS graphics are used to specify every software function, including program flow, and are automatically processed to generate deliverable code. Additional software tools aid in testing and documenting the engine control software. Many software tools are developed in-house, with the benefits of faster response on tool changes and tools better matched to user needs. BOGS is shown to aid in creating structured, modular, readable software that is efficient. The same BOGS language and supporting tools can be used to specify all engine control software designs, independent of target language or CPU. Bendix engine control software designs have common architectural features that support real time control and testing. Self-test functions are common between projects. PC-based software test stations are used to achieve real time software testing on the target CPU at the developer's desk. Speed of execution of tools has improved dramatically as they were rehosted on PC-compatible machines and rewritten to take maximum advantage of the PC capabilities.

QUAD: a computer package for the analysis of QUantal assay data

The computer package QUAD has been developed at the University of Kent, U.K. It is menu-driven and written in Advanced BASIC. It runs on IBM PC compatible machines equiped with a suitable graphics facility such as CGA or simulated CGA. QUAD is available on a floppy disk, for a small handling charge. QUAD has four main functions: it performs a logit analysis of quantal assay data; it provides a flexible way of analysing the data, allowing dose transformations and providing alternative confidence intervals for ED p values; it produces a range diagnostics for assessing the fit of models to data; it provides and fits two families of extended models, each containing the logit as a special case. The package makes use of the latest statistical research, and fitted models are displayed by means of the good graphics facilities available on microcomputers. This document describes the facilities available in detail, and provides and discusses illustrations of the package at work. QUAD has been designed as a pilot package. Further additions and developments are planned and described later.

Paralanguage and human-computer interaction. Part 2: comprehension of synthesized vocal segregates

Abstract Abstract. The comprehension of synthesized vocal segregates was studied using a paired-associate learning task. Twenty-one naive subjects attempted to learn associations between six vocal segregates and assigned meanings, where the segregates were synthesized using the simple sound facilities common to all PC-compatible machines. In the natural condition sounds were paired with the correct meanings, whereas in the random condition sounds were randomly assigned to incorrect meanings. Subjects in the natural condition showed a significant initial advantage over those in the random condition and significantly better overall performance across learning trials. The results show that uninformed subjects are predisposed to make the correct sound-meaning associations for segregates synthesized with inexpensive hardware, and that associations which are not initially identified are quickly learned. Potential applications are discussed.

ELBAMAP: software for management of electrophoresis banding patterns.

ELBAMAP (Electrophoresis Band Management Package) is a 41-kbyte program written in Borland Turbo Pascal, which will run on IBM PC compatible machines. The program consists of 16 procedures involved in data entry, calculation, comparison and graphic representation of banding patterns. These procedures are selected interactively in response to a main menu and a series of prompts. Database files may be stored for subsequent analysis or addition of data. Pairwise comparisons of banding patterns may be stored as a similarity matrix suitable for use by other packages which will carry out multivariate or cluster analysis. The system has been used successfully for storage and comparison of plasmid DNA digest patterns analysed by agarose gel electrophoresis and seed promoter profiles analysed by SDS-polyacrylamide gel electrophoresis.

Decision Support Systems for the Higher Managerial Tasks

In this paper we describe a number of decision support systems which have been developed in Manchester to help senior managers to tackle important Decision Making problems. The systems deal with both the strategic and the operational decision making levels. Real Life Examples are also given of the use of these systems in different industries (e.g. Retailing, Manufacturing, Transportation and Financial Services) based on work done with European companies in these areas. The systems which are described in the paper could be classed as Hybrid Knowledge Based Systems where managerial intuition is extracted, combined with “hard” data and then a mathematically based inference engine (using optimisation, game theory etc.) is used to recommend a decision based on a particular set of assumptions. The systems also allow the managers to see the impact of changing some of these assumptions on the recommended decisions. The systems also provide the facility of changing/updating the Knowledge Base of the system in the light of new information or new managerial perceptions. All the systems run on IBM personal computers or PC compatible machines with a hard disk. The systems which are described in the paper are Resource-opt (A resource allocation systems), Price-Strat (A system for competitive pricing), Mark-opt (for competitive decision making by manufacturers) and Pharipplan (a business game for the pharmaceutical industry).

PC‐Based Traffic Accident Data Analysis Program

A menu-oriented microcomputer database package has been developed to record and analyze traffic accident data in a small- to medium-sized jurisdiction. Designed primarily for the traffic engineer, the package was developed during a microcomputer software development project funded by the FHWA Rural Technical Assistance Program. The program runs under MS-DOS on IBM PC compatible machines, and requires dBase III or III Plus. KSLAD accepts up to 59 data items from each accident report, nine of which can be defined by the user to meet any particular need. The database can be used with any accident report form, because the allowable values of coded data fields may be altered by the user. Output consists of summary reports based on location or accident characteristic criteria specified by the user, or for the entire data set; a high accident location analysis procedure is also included. The program provides a starting point for the evaluation and correction of high accident locations.