and the development programs are reviewed. It is concluded that the integration of an experienecd test team in the checkout equipment development program would ensure implementation of the total checkout philosophy. Author (ESA) N79-31992# Bell Telephone Mfg. Co., Antwerp (Belgium). S. P. Chellingsworth In ESA Spacecraft Onboard Data Management Dec. 1978 p 229-236 (For primary document see N79-31962 22-60) Avail: NTIS HC A15/MF A01 The need for a reliable automated integration and checkout equipment for fast Spacelab turnaround is identified and the various configurations illustrated. The data intensive nature of the task is examined to highlight the complexity and variability of the data paths. An approach based on stratified hardware and software is discussed with flexibility achieved using interpretive programs and late binding techniques. An electrical ground support equipment based on this approach is described in terms of its major assemblies and links, and with reference to its integral health monitoring features. The operator interface is discussed to emphasize the technological design. Author (ESA) N79-31993# Systems Designers Ltd., Camberley (England). Avail: NTIS HC A15/MF A01 Check-out systems evolved to offer facilities which are effective, proven, and well accepted by their users. However, three major constraints, all undesirable, can be indentified in existing check-out systems: limited processing power, lack of evolutionary capability, and lack of commonality. These constraints are not inherent in the basic concepts or design of the check-out system; rather, they arise at the implementation stage, which introduces restrictions on the modularity and flexibility of the overall system. Advances in hardware and software technology made better implementations both technically and economically feasible. By retaining the existing concepts and facilities, but implementing the check-out system on a modular architecture which is inherently flexible, it should be possible to remove the constraints without sacrificing any of the existing benefits, thereby laying the foundation for a smooth expansion in the capabilities of the check-out systems of the future. Author (ESA) N79-31994# European Space Agency, Noordwikj (Netherlands). MAJOR INFLUENCES IN THE DEVELOPMENT OF OVERALL CHECKOUT EQUIPMENT (OCOE) Des Deaney In ESA Spacecraft Onboard Data Management Dec. 1978 p 251-254 ref (For primary document see N79-31962 22-60) Avail: NTIS HC A15/MF A01 Although standardization of hardware and software is the cornerstone of cost efficiency and reliability of the overall checkout equipment, it must not be allowed to unnecessarily restrict the evolution of the equipment or test methods. Nor, on the other hand, should new technologies be used for their own sake. Some ideas which might be considered as background for a continuous reevaluation of the checkout equipment are given and some of the main areas where changes are taking place which will have a significant impact on the design of future checkout equipment are identified. Author (ESA) N79-31996# European Space Agency, Noordwikj (Netherlands). GUIDELINES TO MEASURING THE PERFORMANCE OF FUTURE CHECKOUT SYSTEMS Wim van Leeuwen In ESA Spacecraft Onboard Data Management Dec. 1978 p 259-260 (For primary document see N79-31962 22-60) Avail: NTIS HC A15/MF A01 Measuring techniques for future overall checkout equipment are discussed. A summary of the existing measuring aids and suggestions on how to further develop these techniques are presented. Author (ESA) N79-31997# European Space Agency, Noordwikj (Netherlands). A LOOK AT THE FUTURE OBDH GROUND SUPPORT REQUIREMENTS Oscar Pace In ESA Spacecraft Onboard Data Management Dec. 1978 p 261-263 (For primary document see N79-31962 22-60) Avail: NTIS HC A15/MF A01 A brief look at future requirements of the ESA Standard Onboard Unit and Sub-system Test Equipment is presented and some suggestions as to how these requirements might be met are made. The introduction of onboard intelligence and the related testing approach together with the necessity of having a clear definition of software/hardware testing interfaces and boundaries are mentioned. The need to have the onboard signals accessible to the test equipment in order to decrease the complexity of the ground hardware and to increase its failure analysis capability is stressed. Finally, a model of the sub-system test process is proposed in order to optimize both the design of the onboard unit/sub-system and the related test equipment. Author (ESA) N79-31999# European Space Agency, Noordwikj (Netherlands). POSSIBLE IMPACT OF MICRO-ELECTRONICS DEVELOPMENT ON THE OPERABILITY AND MAINTAINABILITY ASPECTS OF A GPCOE SYSTEM Marc Chofflet In ESA Spacecraft Onboard Data Management Dec. 1978 p 267 (For primary document see N79-31962 22-60) Avail: NTIS HC A15/MF A01 An outline of the main areas of a General Purpose Checkout Equipment (GPCOE) system where micro-electronic utilization is likely to improve the operability, and maintainability features is presented. It is concluded that a sensible usage of microelectronics technology can significantly improve the operability and availability of the GPCOE systems with a minimum cost impact at the level of capital involved and a significant savings in terms of operation and maintenance costs. Author (ESA) N79-32001# European Space Agency, Noordwikj (Netherlands). PAYLOAD SENSOR DATA PROCESSING ASPECTS R. W. Okkes In ESA Spacecraft Onboard Data Management Dec. 1978 p 275-277 (For primary document see N79-31962 22-60) Avail: NTIS HC A15/MF A01 The benefits which could be obtained by performing the processing of payload sensor data on board the spacecraft are considered. Following a general description, its applicability to earth observation missions with respect to processing of SAR (Synthetic Aperture Radar) data and image data reduction on board is covered in some detail. The achievements made within the European Space Agency in the area of payload sensor data processing are summarized and the development program to implement the required facilities for future missions is indicated. Author (ESA) N79-32002# European Space Operations Center, Darmstadt (West Germany). PAYLOAD DATA PRE-PROCESSING C. Mazza In ESA Spacecraft Onboard Data Management Dec. 1978 p 279-290 refs (For primary document see N79-31962 22-60) Avail: NTIS HC A15/MF A01 Some aspects of overall payload data management normally indicated as pre-processing activities are reviewed. Pre-processing deals with the correction or geometric and radiometric distortions to give an image corresponding to an idealized undistorted system. A summary of the most important processing functions and of the corresponding algorithms is given. The results of an investigation on ground control points selection through the sequential similarity detection algorithm, a mapping function definition, computations, and image resampling techniques are presented. Where pre-processing is applicable, some aspects of pre-processing potential are examined. Author (ESA) N79-32003# Engins Matra, Velizy (France). Lab. de Traitment des Images. IMAGE DATA REDUCTION G. E. Lowitz In ESA Spacecraft Onboard Data Management Dec. 1978 p 291-298 refs Sponsored by ESTEC Original contains color illustrations (For primary document see N79-31962 22-60) Avail: NTIS HC A15/MF A01 A survey of some ESA sponsored image processing research is presented. Subjects reviewed include cluster compression of multispectral imagery, iterative clustering algorithms, clustering into a variable (adaptive) number of classes, end to end data management cost benefits, thematic mapping of a whole frame. noise filtering, and cascade clustering. Author (ESA) N79-32004# Ferranti Ltd., Bracknell (England). ING D. J. Bonfield, K. M. Harvey, and J. R. E. Thomas In ESA Several synthetic aperture radar real time processor architectures, suitable for use onboard a satelilite, are discussed. The principles of Synthetic Aperture Radar (SAR) are explained. Data processing for SAR, SAR azimuth processing architectures, multilook processing, and image formatting are reviewed in detail. The applicability of charge coupled devices and surface acoustic wave devices to the implementation of these architectures is examined. Author (ESA) N79-32005# Marconi Co. Ltd., Great Baddow (England). GROUND PROCESSING OF SEASAT-A SAR DATA AT AN EARTHNET STATION A. B. E. Ellis In ESA Spacecraft Onboard Data Management Dec. 1978 p 309-316 refs (For primary document see N79-31962 22-60) Avail: NTIS HC A15/MF A01 A proposed ground based processor for SEASAT-A Synthetic Aperture Radar (SAR) is described. The data from the satellite is recorded digitally prior to being correlated in both the range and along-track directions to produced a radar image of a strip Advanced systems for the numerical processing of SAR (Synthetic Aperture Radar) images are described. Several data processing system architectures are proposed, built around the MITRA 125 computers and the PROPAL 2 associative parallel processor. The various systems are characterized by their processing power and their ability to support different numerical image processing algorithms. The highest performance system in the first study processes 40 images in 24 hours. The system proposed in the second study processes one image in about 8 hours. All these systems are entirely programmable; they can support diverse processing algorithms and can be used for developing and validating all other computational methods. and will also assist in the final integration and checkout of the MIME hardware. This report analyzes the conceptual implementations of monitor/debugger systems and applies these implementations to the MIME computer. The analysis results are presented which recommend that a dual processor hybrid monitor/ debugger implementation should be developed for the MIME. This implementation of a hybrid system combines the flexibility of software with the speed of hardware. The MIME Monitor/ Debugger System design presented in this report when fabricated and tested, will produce a monitor/debugger system that is interactive with the system user, has the flexibility to encompass changing user requirements, and has the speed to monitor and control the real-time operation of the MIME computer. GRA The nature of integrated circuit technology dictates an upper limit on the number of gates that can be placed on a single chip and still permit production that is economically feasible. This upper limit is constantly being increased by improving technology. The first integrated circuits had a small number of individual gates on a chip. As technology progressed, mediumscale-integrated (MSI) chips were produced with complex functions such as multiplexers, counters and shift registers. Early in the 1970's the maximum number of gates had increased to the point where a complete system or subsystem, such as a microprocessor could be placed on a single chip. This technology is referred to as large-scale-integration (LSI). GRA The General Purpose Input Processor (INPUTP) program is a very flexible, entirely data-driven utility that may be used as an input preprocessor to any FORTRAN program. The INPUTP program reads two external files to define the names and default values for all user input. Then through input, the user may override the default values for any input parameters. The input processor generates two FORTRAN block data routines containing DATA statements to define the input parameters. These routines must be compiled and loaded to initialize all input variables. All data is read by the input processor in a free-form format, which simplifies the creation and maintenance of the data files and greatly reduces the chances for user input errors. The INPUTP program is coded in the SIMSCRIPT 11.5 language, and is operational on the Control Data Corporation (CDC) 6700 computer system under the SCOPE 3.4 operating system. GRA N79-32013# Sandia Labs., Albuquerque, N. Mex. MICROPROCESSOR CONTROLLED DATA ACQUISITION SYSTEM R. L. White Jul. 1978 30 prefs (Contract EY-76-C-04-0789) This report documents a design effort for an automated system to record and report the configuration status of software for Air Force embedded computer systems. The work included requirements analysis, software design, and data-base design. Because of the flexibility given to program managers in tailoring their reporting requirements and in selecting the data integrator, only the requirements of a single AFSC program office were presented in detail. However, the requirements of other offices were considered as well. Current software engineering techniques were used to derive the design. They are highly recommended for use on other software development projects. GRA evaluation is performed in three steps. First, the existing system is modeled into its logical equivalent using bubble charts. This model shows the flow of data through the system, and the activities performed on that data. Second, a similar model is produced describing the required system as defined by the users. This model is a representation of the users' desires and requirements, and is similar to a model which might be produced during the requirements definition phase of a computer's life cycle. The third step is to compare the two models to evaluate the existing system's effectiveness, and reveal areas requiring modification for full utilizatin of the system. Following the evaluation, several recommendations and changes are proposed to increase the system's capability to meet the user requirements. GRA (Contract NO0014-75-C-0729) (AD-A069310; Serial-T-388) Avail: NTIS HC A03/MF A01 CSCL 12/1 The multi-level programming problem is defined as an n-person nonzero-sum game with perfect information in which the players move sequentially. The bi-level linear case is addressed in detail. Solutions are obtained by recasting this problem as a standard mathematical program and appealing to its implicitly separable structure. The reformulated optimization problem is linear save for a complementary constraint of the form <u,g> O This constraing is decomposed in a manner that permits us to achieve separability with very little cost in dimensionality. A general branch and bound algorithm is then applied to obtain solutions. Unlike the conventional mathematical program though, the multi-level program may fail to have a solution even when the decision variables are defined over a compact set. An auxiliary optimization problem is employed to detect such failure. Finally, the general max-min problem is discussed within the bi-level programming framework. Examples are given for a variety of related problems. N79-32019# Massachusetts Inst. of Tech., Cambridge. for Information and Decision Systems. GRA Lab. Any programming language that supports concurrency needs a synchronization construct with which to express access control for shared resources. This thesis examines synchronization constructs from the standpoint of language design for reliable software. The criteria a synchronization mechanism must satisfy to support construction of reliable, easily maintainable concurrent software are defined. Some of these criteria, such as expressive power, can be defined only with respect to the set of problems the mechanism is expected to handle. A definition of the range of problems considered to be synchronization problems is therefore needed. Such a definition is provided by describing the possible types of constraints that may be imposed on access to shared resources. We then use this taxonomy of synchronization constraints to develop techniques for evaluating how well synchronization constructs meet the criteria discussed. These techniques are then applied to three existing synchronization mechanisms: monitors, path expressions, and serializers. Evaluations are presented, and the three mechanisms compared. GRA N79-32021# Southern Methodist Univ., Dallas, Tex. Dept. of Computer Science. IMPLEMENTATION AND EVALUATION OF INTERNAL ARITHMETIC SOFTWARE. REPORT 5: THE CDC CYBER 70 SYSTEM David A. Cohn, J. Brian Potter, and Myron Ginsberg Apr. 1979 107 p refs Avail: NTIS (Contract DACA39-77-M-0105; Grant NSF MCS-77-06611) This is Report 5 of a series entitled 'Implementation and Evaluation of Interval Arithmetic Software'. The potential user of this or any other interval analysis package should take into consideration the limitations of this technique. Some of the limitations are inherent in all interval analysis implementations and others are dependent upon one specific package. The user should be aware that software interval analysis tends to be very slow. Cases run on one CDC Cyber 70 have required as much 100-fold increase in execution time over a noninterval version. Thus, large production codes involving significant amounts of floating-point computations are not viable candidates for a complete interval implementation. However, small portions of the computation might benefit from use of the package. The computed bounds using interval analysis can be overly pessimistic as well as being time-consuming to determine. The tightness of the bounds is dependent upon the arithmetic of the host computer and possible numerical anomalies introduced by compile-time arithmetic. Another factor affecting the performance of the interval package is the accuracy of the host computer's FORTRAN library routines. GRA N79-32022# Oak Ridge Gaseous Diffusion Plant, Tenn. DESCRIPTION OF DATA ENTRY FOR AUTOMATED COST ESTIMATING N. H. VanWie Apr. 1979 45 p refs (Contract W-7405-eng-26) (K/CSD/TM-29) Avail: NTIS HC A03/MF A01 A series of computer programs was developed to aid in the computation and reporting of a proiect cost estimate. These programs are operative on any project, regardless of scale, as long as a minimal set of rules for preparation of the data base is followed. The data base for a project is subdivided into four types of data or files: a title file, a front-end file, a file of cost sheets for the base cost estimate, and a file of cost items with their schedules for the time-phased estimate. The data requirements formating and specifications for preparation of these files to enable computation are described. Examples are presented and alternative approaches to accomplish an end result are explained. DOE N79-32023# Argonne National Lab., III. IMPLEMENTATION AND TESTING OF OPTIMIZATION SOFTWARE J. J. More 1978 16 p refs (Contract W-7405-eng-38) (DOE/TIC-10096) Avail: NTIS HC A02/MF A01 The development of a transportable optimization software is outlined. Guidelines for the implementation of optimization software are suggested, and the (often dramatic) effect that these guidelines have on the performance of the implementation is shown. In addition, the weaknesses in the usual approaches to performance testing of optimization software are discussed and DOE some remedies are suggested. N79-32024# Argonne National Lab., III. TESTING UNCONSTRAINED OPTIMIZATION SOFTWARE Jorge J. More, B. S. Garbow, and K. E. Hillstrom Jul. 1978 96 p refs (Contract W-31-109-eng-38) (ANL-AMD-TM-324) Avail: NTIS HC A05/MF A01 (Contract ESOC-3365/78-D-JS(SC)) (ESA-CR(P)-1208-Vol-1) Avail: NTIS HC A04/MF A01 The results of a numerical study of conservative filters are presented in a two volume report. In this volume the algorithms used and the experiments conducted are described. A variety of conservative prediction and updating filtering algorithms, which were obtained in a previous theoretical study, were implemented and tested. After a unified reformulation of the algorithms for the different concepts of conservativity, a general numerical method was devised to obtain conservative terms by optimization techniques. Moreover, procedures to select in an optimum way arbitrary parameters in algorithms were designed. The methods were implemented and tested in typical orbit determination problems. Tests were made separately for the prediction and for the updating step, since they are of a totally different nature. Results obtained are reported and commented on. Besides the verification of conserveness, they point out satisfactory results. but at the same time reveal some critical items in the applications. The software used is also described in detail. Author (ESA) the form of computer programs to convert expressions with very large numbers of literals to networks meeting the indicated bounds, leaving only small (eg. 3 to 5 literals) networks to be constructed by hand or through table search. All bounds and constructions in this paper are based upon the size of the input expressions where for any expression E the size of E is represented by abs. val. (E) and is equal to the number of literals in E. The techniques presented treat each literal as distinct (eg. AB-AC has 4 literals). Thus, these techniques are most useful when the size of the expression is large and the number of repetitions of variable names is relatively small. GRA N79-32028# SEMA (Metra International), Paris (France). (ESA-CR(P)-1186) Avail: NTIS HC A18/MF A01 Concerning view factors computation, previous work was continued in order to define algorithms ensuring sufficient precision in any case. New preshade methods were developed so that the system would save a lot of central processing unit time when modifying of combining models. Much work was done on the management aspects; items and concepts are precisely defined and a first description of the specifications of the treatments is presented. Author 63 CYBERNETICS Includes feedback and control theory. For related information see also 54 Man/ System Technology and Life Support. (Contract ESOC-3365/78-D-JS(SC)) (ESA-CR(P)-1208-VOL-2) Avail: NTIS HC A08/MF A01 The results of a numerical study of conservative filters are presented in a two volume report. In this volume a complete description of the software is given. The conservative filter software is composed of the filter package itself and a special program of plotting. The filter package is divided into four steps with an overlay structure. For the overly structure, a user's guide chapter is included. A seperate plotting program uses two files generated by the filter to produce a picture file which can be used by Tektronix of Stromberg-Carlson devices. References to volume 1 details concerning the implemented equations are given. 62 COMPUTER SYSTEMS Includes computer networks. K. L. Author (ESA) Michael G. Safonov and Michael Athans 1 Sep. 1979 refs N79-32030*# Massachusetts Inst. of Tech., Cambridge. N79-32027# Illinois Univ. at Urbana-Champaign. Science Lab. The design of high speed digital systems requires careful effort to minimize the propagation delay through combinational logic networks. For technological reasons these networks are often most desirably constructed from either NAND or NOR gates with various fan-in limits. It is simpler for the designer to write Boolean expressions which define the desired network behavior in terms of the general class of binary Boolean operators (henceforth referred to as B2) instead of multiple input NAND or NOR operators. The main objective of this paper is to provide a methodology for convenient design of combinational networks. The techniques provided here are not merely existence proofs but are constructive and could, for example, be implemented in In order to provide a theoretical tool suited for characterizing the stability margins of multiloop feedback systems, multiloop input-output stability results generalizing the circle stability criterion are considered. Generalized conic sectors with 'centers' and radii' determined by linear dynamical operators are employed to specify the stability margins as a frequency dependent convex set of modeling errors (including nonlinearities, gain variations and phase variations) which the system must be able to tolerate in each feedback loop without instability. The resulting stability criterion gives sufficient conditions for closed loop stability in the presence of frequency dependent modeling errors, even when the modeling errors occur simultaneously in all loops. The stability conditions yield an easily interpreted scalar measure of the amount by which a multiloop system exceeds, or falls short of, its stability margin specifications. KL N79-32031# Air Force Inst. of Tech., Wright-Patterson AFB, Ohio. School of Engineering. SEGMENTATION OF TOUCHING ENGLISH LETTERS |