We describe a software program designed to control a broadband pulse nuclear magnetic resonance (NMR) spectrometer used in zero-field NMR studies of magnetic metals. The software is written in the graphical language L...
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We describe a software program designed to control a broadband pulse nuclear magnetic resonance (NMR) spectrometer used in zero-field NMR studies of magnetic metals. The software is written in the graphical language Labview. This type of programming allows modifications and the inclusion of new routines to be carried out easily by the non-specialist, without changing the basic structure of the program. The program corrects for differences in the gain of the two acquisition channels (U (phase) and V (quadrature)), and automatic baseline subtraction. We present examples of measurements of NMR spectra, spin-echo decay (T-2), and quadrupolar oscillations, performed in magnetic intermetallic compounds.
In the present communication a personal computer control methodology for pH data acquisition and analysis in biological systems is reported. The instrumental control, acquisition, storage, processing and presentation ...
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In the present communication a personal computer control methodology for pH data acquisition and analysis in biological systems is reported. The instrumental control, acquisition, storage, processing and presentation of the experimental data are provided by a data acquisition board, a graphical programming software and numerical analysis,'graphics software. The major objective of this work is to improve the performance and flexibility of the personal computer acquisition system compared with traditional approaches depending on potentiometric recorders. In particular. virtual instruments for interfacing pH meters of different brands to a personal computer and for measuring proton changes in lightly buffered solutions during enzymatic reactions are provided. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.
At the Project Design Center at the Jet Propulsion Laboratory, a concurrent design environment is under development for supporting development and analyses of space instruments and telescopes in the early, conceptual ...
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ISBN:
(纸本)0819428035
At the Project Design Center at the Jet Propulsion Laboratory, a concurrent design environment is under development for supporting development and analyses of space instruments and telescopes in the early, conceptual design phases. This environment is being utilized by a Team I, a multidisciplinary group of experts. Team I is providing study and proposal support. To provide the required support, the Team I concurrent design environment features effectively interconnected high-end optics, CAD, and thermal design and analysis tools. Innovative approaches for linking tools, and for transferring files between applications have been implemented. These approaches together with effective sharing of geometry between the optics, CAD, and thermal tools are already showing significant timesavings.
In the present communication a personal computer control of electrodes particularly suited for mitochondrial research such as the oxygen electrode, the pH electrode and ion-selective electrodes is described. A persona...
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In the present communication a personal computer control of electrodes particularly suited for mitochondrial research such as the oxygen electrode, the pH electrode and ion-selective electrodes is described. A personal computer equipped with a data acquisition board, a color monitor, a graphical programming software and a numerical analysis/graphics software provides complete instrumental control, data storage, processing and presentation of experimental data. The major objective of this work is the analysis and utilization of a virtual instrumentation software for data acquisition and control of electrochemical detectors;this may greatly improve the performance and flexibility of the system compared to traditional approaches such as the potentiometric recorders.
In the paper, the application of the virtual instrument concept for the measurement of magnetic characteristics, such as magnetisation curve, hysteresis and losses in soft magnetic materials, is described. The concept...
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In the paper, the application of the virtual instrument concept for the measurement of magnetic characteristics, such as magnetisation curve, hysteresis and losses in soft magnetic materials, is described. The concept accelerates vastly the design and development phase of a magnetic measurement system, simplifies and shortens the measurements and is extremely versatile.
Modern distributed systems consisting of powerful workstations and high-speed interconnection networks are an economical alternative to special-purpose supercomputers. The technical issues that need to be addressed in...
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Modern distributed systems consisting of powerful workstations and high-speed interconnection networks are an economical alternative to special-purpose supercomputers. The technical issues that need to be addressed in exploiting the parallelism inherent in a distributed system include heterogeneity, high-latency communication, fault tolerance and dynamic load balancing. Current software systems for parallel programming provide little or no automatic support towards these issues and require users to be experts in fault-tolerant distributed computing. The Paralex system is aimed at exploring the extent to which the parallel application programmer can be liberated from the complexities of distributed systems. Paralex is a complete programming environment and makes extensive use of graphics to define, edit, execute, and debug parallel scientific applications. All of the necessary code for distributing the computation across a network and replicating it to achieve fault tolerance and dynamic load balancing is automatically generated by the system. In this paper we give an overview of Paralex and present our experiences with a prototype implementation.
Managing the buffering of data along arcs is a critical part of compiling a synchronous dataflow (SDF) program. This paper shows how dataflow properties can be analyzed at compile-time to make buffering more efficient...
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Managing the buffering of data along arcs is a critical part of compiling a synchronous dataflow (SDF) program. This paper shows how dataflow properties can be analyzed at compile-time to make buffering more efficient. Since the target code corresponding to each node of an SDF graph is normally obtained from a hand-optimized library of predefined blocks, the efficiency of data transfer between blocks is often the limiting factor in how closely an SDF compiler can approximate meticulous manual coding. Furthermore, in the presence of large sample-rate changes, straightforward buffering techniques can quickly exhaust limited on-chip data memory, necessitating the use of slower external memory. The techniques presented in this paper address both of these problems in a unified manner.
We describe K-NET, a support system for development of sequence control programs. The K-NET description model is based on the colored Petri net and timed Petri net. K-NET concisely expresses sequence control flow incl...
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We describe K-NET, a support system for development of sequence control programs. The K-NET description model is based on the colored Petri net and timed Petri net. K-NET concisely expresses sequence control flow including synchronization, interlock and concurrence, and provides high-level data processing by being combined with a conventional procedural language. K-NET has an editor, simulator, generator, reporter and monitor to support the control program development procedure ranging from basic and detail design to programming and testing. We have added a new function to K-NET so it assists development of control programs for programmable controllers, and have applied it to an automatic bolt supplying system. The operation results are satisfactory.
The subject of this paper, the Integrated Model Development Environment (IMDE), addresses basic difficulties experienced in simulating airbase logistics. These difficulties arise during two major modeling activities: ...
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The subject of this paper, the Integrated Model Development Environment (IMDE), addresses basic difficulties experienced in simulating airbase logistics. These difficulties arise during two major modeling activities: 1) developing the conceptual model, and 2) translating the conceptual model to a particular simulation software implementation. The difficulty of the former activity is largely irreducible, a consequence of the inherent complexity of large, dynamic, and uncertain military systems such as airbase logistics. However, while the latter activity is also complex, key technologies have the potential to simplify this part of the modeling process. This paper discusses how a synergistic combination of object-oriented programming and data bases, graphical programming, software environments, and powerful computer workstations can provide significant enhancements to simulation modeling capabilities. In addition, the paper presents the object-oriented decomposition of the airbase logistics domain as it is implemented in IMDE. The paper also discusses how the IMDE design meets the needs of airbase logistics modelers with widely differing capabilities and mission requirements. This is accomplished by providing different modeling "levels", each with its own user interface, skill requirements and degree of access to modeling tools. The paper concludes with a description of the current status of this large scale research and development effort.
This paper explores analytical properties of programming languages with dataflow graph semantics. Such languages are currently used in certain application domains, such as digital signal processing, and a better analy...
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This paper explores analytical properties of programming languages with dataflow graph semantics. Such languages are currently used in certain application domains, such as digital signal processing, and a better analytical understanding of their properties may broaden their applicability. One of their most serious problems is that subtle inconsistencies between parts of the dataflow graph can be inadvertently created. These inconsistencies can lead to deadlock, or in the case of nonterminating programs, to unbounded memory requirements. Consistency is defined to mean that the same number of tokens is consumed as produced on any arc, in the long run. A token-flow model is developed for testing for consistency. The method is a generalization of consistency checks for synchronous dataflow (SDF) graphs [17]. Although inspired by the similar tests of Benveniste et al. [7], the method and the languages to which it applies are different.
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