Inexpensive Microcomputer Research Articles

WAALSURF: Molecular graphics on a personal computer

The advent of increasingly powerful graphics boards for personal computers will soon allow quite advanced molecular graphics applications on inexpensive personal computer configurations. This paper describes an interactive molecular data display program, called WAALSURF, implemented on two different personal computers, IBM's PC-AT equipped with a Professional Graphics Adapter and Commodore's Amiga. These programs allow the inspection of data bases containing data of molecules with some thousand atoms each. The molecular data can be used to generate a range of representations from skeleton, ball-and-stick to space filled Van der Waals surfaces. To foster 3D perception coloring, perspective and lighting depth cues are included, with stereo images as an option. A versatile user interface is provided, allowing the operator to manipulate objects as well as display parameters. Under interactive control the user may rotate molecules in static or animation mode, label sections, strip outer layers and dock molecules while changing the color and the number of atoms displayed. A logging facility is provided to resume a new session where the previous one left off.

One hundred differential equations execute directly on the IBM PC

Inexpensive personal computers (IBM PC/XT/AT and com patibles) can do very respectable dynamic-system simula tions at remarkable speed, as shown in this brief technical note. The direct-executing ENHANCED DESIRE system solves up to one hundred ordinary differential equations typed and edited on the CRT screen, without noticeable delay for program translation. Monochrome or color graph ics are produced.

Analysis of Geophysical Logs of Water Wells with a Microcomputer

ABSTRACTA microcomputer can be a significant aid in the analysis of geophysical logs of wells used in investigations of ground‐water systems. Geophysical logs, test data, and laboratory analyses present a large volume of data that can most efficiently be manipulated with a computer. Techniques for the analysis of logs using mainframe computers and minicomputers have been developed and used in the petroleum industry for a number of years. These techniques have not been used widely in ground‐water investigations because available programs were oil‐oriented, and both programs and computers were too expensive to be cost‐effective for most ground‐water investigations. These programs also tended to be too complex for the part‐time user to learn. The advent of the relatively inexpensive microcomputer and a number of inexpensive, easy‐to‐use generic programs made computer‐aided log analysis available to most hydrologists.A microcomputer can be used to transfer well logs by telephone and to correct the data received. The logs then can be collated, compared, and analyzed statistically. Two logs can be cross‐plotted in order to identify lithology or to provide porosity corrected for matrix effects. Logs can be plotted against laboratory analyses of cores or samples for purposes of log calibration.As an example of this technique, logs and core data from a test well completed in the Madison Limestone were analyzed using a microcomputer and generic programs. Computer‐aided log analysis facilitated the identification of the lithologic units penetrated and the intervals of secondary porosity that produced water. Plots of logs and other data included in the paper were reproduced directly from the graphics subprogram that is part of the spreadsheet program.

A Low Cost Adaptive Autopilot for Inland Ships

This paper discusses the design of an autopilot for inland ships. The autopilot makes use of adaptive strategies which can be implemented in inexpensive microcomputers. As the paper makes clear, both the adaptive features and the possibility to implement these in inexpensive hardware are essential for realizing an acceptably priced autopilot. As an example of these, the adaptive controller of the ship's hydraulic steering machine is described. This controller computes on-off signals for the relays which control two hydraulic valves. For the realization of the autopilot an 8-bit microprocessor system is chosen which can be programmed in a high-level language. The reasons for selecting this system are given along with some properties of the system, which have to be taken into consideration in the software design process. The results of simulation and of full-scale trials are described.

DEVELOPMENTS WITH THE COBLO BLOCK ADJUSTMENT PROGRAM

AbstractIn spite of the striking progress in block adjustment techniques, it is widely assumed that their application continues to be out of reach for a large part of the photogrammetric community that cannot afford expensive computer systems. The COBLO program performs rigorous block adjustment with models and can be implemented even on inexpensive microcomputers. The first COBLO versions are in operation in several places in South America and Europe and the latest versions, which are considerably more efficient, are now being introduced. This paper describes the main features of different COBLO versions and presents the experience of some users.

Microcomputers in the statistical environment of developed and developing countries

The influence of cheap and powerful microcomputers on data processing policies is currently debated in most statistical agencies. Many see the fast evolution of this new technology as a threat, some as a promise. The main effects of microcomputers on the statistical environment will be external as opposed to internal. Their impact on access to data may alter not only the production process of statistics but also the kinds of statistics we produce and, perhaps, the very concept of statistics. The use of microcomputers will probably tum out to be more profitable regarding software rather than hardware aspects, although advantageous evolution with respect to hardware remain possible through the installation of local area networks provided that investment policies are sufficiently flexible. In developing countries, the emergence of inexpensive and reliable microcomputers has created particular hopes for statistical work. Our current experience indicates that many of these expectations may well be fulfilled.

The Decision Support System of the Greek Popular Lottery

The D.S.S. to be considered in this paper is a real case study which is concerned with the raffle of the Greek popular lottery. The applied technique is an original one from the point of view of computational methods in operational research and can be applied in any organization which has a lottery. It is based on the construction of finite semi-groups or semi-Latin squares under stochastic conditions. The proposed technique, implemented on a mini-computer or an inexpensive microcomputer, finds a deterministic decision-table that corresponds to a stochastic problem.

Description of electrophysiological data using a microcomputer*

ABSTRACT. Customization of an inexpensive microcomputer and peripherals to produce hard copy outputs of electrophysiological data is described. The system uses any of the Apple II series computers and a common A/D+D/A card together with a digital plotter. For the 1–2 s recordings normally used in studies of insect chemoreception, this computer configuration can replace more laborious permanent hard copy production techniques. Additional analytical programs can easily use the three data files produced by the current sytem.

A Microcomputer‐Controlled Leafweighing System1

AbstractA completely, automated weighing system was built to facilitate large numbers of repetitive wheat‐leaf weighings required in a drought program (wheat: Triticum aestivumL.). Leaf samples (up to 265) were clipped to holders suspended from hangers on a conveyor chain. The samples were then repetitively weighed (three samples per minute) throughout the day to determine individual water‐loss rates. An inexpensive microcomputer controlled all operations including movement of the conveyor chain, transfer of samples to and from the balance, taring and weighing operations, and data storage. With minor modifications this weighing system can be easily applied to other types of routine weighing needed in agricultural research.

An inexpensive microcomputer digital imaging system for densitometry: quantitative autoradiography of insulin receptors with 125I and LKB ultrofilm

This article describes a video digitizing system designed for measuring film optical density. The system, which is based on a 6-bit (64 gray level) digitizer, solid state video camera, and Apple II microcomputer, digitizes a rectangular area selected by the operator and converts the gray level values into preselected standard units. In order to develop autoradiographic standard curves for quantitative autoradiography with 125I-insulin, liver slices labeled with 125I-insulin and plastic sections containing known amounts of tritium were apposed to the same sheet of LKB Ultrofilm for exposures of 1–7 days. The results indicate that 3H plastic standards can be used to calibrate QAR of 125I-labeled ligands with LKB Ultrofilm. The Apple system was also used to measure binding of 125I-insulin to the external plexiform layer (EPL) in slices of the rat olfactory bulb. Results suggest that the EPL has two binding sites for insulin, a high affinity site with K d = 1.0 × 10 −8 M and a low affinity site having a K d = 1.4 × 10 −5 M.

Multilead ECG analysis

This paper describes the results of our recent research in computer-assisted ECG VCG interpretation. It comprises new developments which were initiated by the advent of relatively inexpensive microcomputers. Our previous systems performed an off-line analysis of ECGs. Currently, there is a trend to move computer power near to the patient and to provide on-line analysis of ECGs. Besides the advantage of the direct availability of the ECG interpretation, quality control will reduce the number of uninterpretable ECGs and hence the number of repeated recordings. This paper describes the requirements that were established for a system for on-line ECG analysis. The system is based on our modular approach just like our off-line system, Modular ECG A Nalysis System (MEANS). Changes in the Methods and software had to be made mainly because of the simultaneity of all ECG leads and the concurrency of the processing tasks. Other modifications and extensions of the algorithms necessary to meet the requirements of on-line ECG interpretation especially those related to processing speed, are discussed, and evaluation results are presented

Optimal design of structures with multiple design variables per group and multiple loading conditions on the personal computer

A finite element based programming system for minimum weight design of a truss-type structure subjected to displacement, stress, and lower and upper bounds on design variables is presented. The programming system consists of a number of independent processors, each performing a specific task. These processors, however, are interfaced through a well-organized data base, thus making the tasks of modifying, updating, or expanding the programming system much easier in a friendly environment provided by many inexpensive personal computers. The proposed software can be viewed as an important step in achieving a “dummy” finite element for optimization. The programming system has been implemented on both large and small computers (such as VAX, CYBER, IBM-PC, and APPLE) although the focus is on the latter. Examples are presented to demonstrate the capabilities of the code. The present programming system can be used stand-alone or as part of the multilevel decomposition procedure to obtain optimum design for very large scale structural systems. Furthermore, other related research areas such as developing optimization algorithms (or in the larger level: a structural synthesis program) for future trends in using parallel computers may also benefit from this study.

Microcomputer-driven digital data processing of mouse actograph activity

The system is designed to measure the ambulatory activity of each of a set of eight mice, using a group of actographs driven by an inexpensive microcomputer, thus avoiding unnecessary usage of a costly instrument over an extended period. A toric actograph was chosen since it is sensitive to ambulatory activity even at low amplitudes. In this computerized system, actograph data are recorded on audio cassettes during the experiment, and later reread by an Apple II microcomputer for storage on floppy disks. This makes it possible to perform all types of mathematical treatment at a later date. Since the experiments last for several days and the environment is kept constant, activity rhythms can be studied. The data processing takes place off-line and employes digital filtering, which is shown to be preferable for the presentation of temporal data to a simple smoothing, by a moving average. Spectral analysis is obtained through a discrete Fourier transform. Two methods of reconstitution of temporal curves from the frequency analyses are presented: an inverse Fourier transform, or summation of the Fourier series.

Programming for the DNA analysis of FCM data on an IBM microcomputer.

The analysis of data generated on a flow cytometer (FCM) is often performed on a computer obtained especially for dedicated use with the flow cytometer. This computer component can be expensive and also presents the FCM user with the added burden of mastering specialized programming language or of accepting the secret analytical processes of protected proprietary program routines. We believe that the evolution of more accurate and efficient FCM analyses that have the power to consider complex signal distributions can be assisted by the availability of analysis programs written in languages common to many users. DNA analysis routines written for a relatively inexpensive microcomputer (IBM PC/XT) in Basic and Pascal are described here. The routines can automatically process multiple FCM data files and can provide high-resolution graphic hardcopy. A foreground/background utilization is also described that allows the computer to be available for other uses in the laboratory.

Visual Stimulator for Eye Movement Studies Based on a Microcomputer System

SummaryA visual stimulator system for studies of eye movements has been developed. The system is controlled by an inexpensive microcomputer. It is employed for otoneurological studies both in clinical work and in research, but can also be applied for studies of eye movements in other medical areas. Three types of eye movements are produced, viz. saccadic and smooth pursuit eye movements and optokinetic nystagmus. The stimulator system can be connected to another computer for an analysis of eye movements.

Rechnergestütztes Experimentieren in der chemischen Reaktionstechnik

AbstractComputer‐aided experiments in chemical reaction engineering. In recent years, relatively inexpensive microcomputers have become available which are very suitable for data acquisition, data storage, data handling, and for control and experimental design of laboratory reactors in reaction engineering. Various experimental set‐ups (integral, gradientless, and pulse reactors) as built in the Institute for Technical Chemistry I of Erlangen‐Nürnberg University are presented, their advantages and remaining problems discussed, and some results on kinetic analysis and reaction modelling reported.

A microcomputer system for analysis of coronary artery calibre and blood flow.

Measurement of myocardial blood flow and assessment of coronary calibre in man has important clinical and research value. An inexpensive microcomputer system has been developed to facilitate analysis of each of these. Coronary sinus and great cardiac vein blood flow are measured using the thermodilution technique. The output of the temperature measurement circuitry is digitized and used to calculate blood flows. For coronary artery calibre measurement, the outline of an arterial segment recorded during coronary arteriography is digitized manually. The microcomputer system provides a graphic display of the digitized artery and calculates diameters throughout its length. Excellent correlations were observed between computer and manual methods for both systems.

A microcomputer system for simulation modelling

Microcomputers are now widely used for discrete-event simulation work in Operational Research. An inexpensive microcomputer system for simulation modelling is presented. Based on an Apple II, it allows the programmer to develop three-phase activity based interactive models in Ucsd Pascal. Use is made of disc emulation for the provision of simultaneously available pictorial displays and the extension of fast access on-line memory for the development of large simulations. Use of a microcomputer speeds development time and gives the user a transportable computer dedicated to the simulation. Pascal facilitates the development of readable portable simulations. The simulation of a conveyer belt system demonstrates the simplicity and flexibility of the pictorial display. A practical study in the Health Service (modelling the treatment of chronic renal failure) illustrates that the package may be used to simulate a real and complex system.

A microcomputer-based program for video analysis of chemotaxis under agarose

We have developed a computerized system for the quantification of video images of cell migration patterns obtained in the chemotaxis under agarose assay. This system allows either manual or automatic measurement of standard parameters of chemotaxis, as well as quantification of three new parameters which reflect mean cell movement and chemokinesis. The parameters of mean cell population movement are not obtainable by the traditional analysis of the chemotaxis under agarose assay. Our system operates on an inexpensive microcomputer, is easy to use and provides data output in a format that is directly transferable to standard statistical packages.

Analysis of radioligand binding experiments: A collection of computer programs for the IBM PC

It is now well accepted that graphic methods are a poor choice of analytical technique for analyzing radioligand binding data given the complexity of some radioligand-binding site interactions; this is true not only for studies performed at equilibrium but also for those examining kinetic properties of the radioligand. As a consequence the computer plays an important role in all forms of radioligand binding experiments because it reduces the labor-intensive calculations associated with such experiments and it allows the use of more appropriate weighted nonlinear curve-fitting techniques that more accurately describe the radioligand-binding site interaction. This paper describes a collection of four programs ( klnetic, ebda, ligad, and lowry) that can be used to analyze most forms of radioligand binding experiments. The programs have been adapted for use on an IBM PC, which is a popular, inexpensive microcomputer and which is well suited to the analysis of radioligand binding data.