21 research outputs found
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Writing World-Wide Web CGI scripts in the REXX language
No full textThis talk is aimed at people who have experience with REXX and are interested in using it to write WWW CGI scripts. As part of this, the author describes several functions that are available in a library of REXX functions that simplify writing WWW CGI scripts. This library is freely available at //www.slac.standard.edu/slac/www/tool/cgi-rexx/
Nut en methoden van tijdstudiën inzonderheid bij massa-productie
No full textCivil Engineering and Geoscience
Development of a Knowledge-Based Engineering Application to Support Conceptual Fuselage Sizing and Cabin Configuration: Towards a Next Generation Multi-Model Generator
No full textThe department of Flight Performance and Propulsion at the Faculty of Aerospace Engineering has developed the Design and Engineering Engine (DEE) concept to supportMultidisciplinary Design Optimization (MDO) of complex products. The goal of the DEE is to accelerate design, analysis and optimization by automating repetitive and non-creative design activities. A central part of the DEE is theMulti-Model Generator (MMG), a Knowledge-Based Engineering (KBE) application that provides a generative modeling capability. Over the years several aircraftMMGs have been developed to support aircraftMDO. The previous aircraft MMG was built using the KBE system GDL. Over the years, several limitations of the fuselage model included in the GDL MMG, called DARfuse, have become apparent. Therefore, this thesis describes research done into the development of a new parametric fuselage model to be included in the next generation Multi-Model Generator, currently under development within the department of Flight Performance and Propulsion. The new fuselage model is called ParaFuse and has been developed using the KBE system ParaPy. The scope of ParaFuse is limited to conventional, low-wing, passenger aircraft certified under CS 25 airworthiness requirements. The first goal of the thesis was to develop a new parametric fuselage model. The implemented modeling approach uses longitudinal guide curves and fuselage cross sections to generate the final fuselage geometry. A separate parameterization approach is taken to provide a smooth nose end cap. Furthermore, a parameterized wing-body fairing has been implemented in ParaFuse. As a second goal, an inside-out fuselage sizing and cabin configuration method has been developed and implemented to automate the fuselage layout and sizing process. The inside-out design method can be used to automatically generate the outer fuselage geometry and interior components based on payload requirements posed by the user, such as passenger capacity and cargo type. The inside-out sizing method has been validated by reconstructing several reference aircraft using ParaFuse. On average, the error of the external dimensions of the resulting fuselages is 2% with respect to the dimensions of the fuselage of the actual aircraft. Thus, it can be concluded that the implemented inside-out sizing method can be used to accurately size the fuselage of conventional, low-wing, passenger aircraft. In addition, an outside-in cabin configuration method has been implemented in ParaFuse. This method can be used to perform cabin (re)configuration studies of fuselages with fixed external dimensions. ParaFuse is able to generate the fuselage models, including cabin interiors, within 20 seconds. This allows the user to rapidly evaluate a large number of different fuselage models. To demonstrate the functionalities of the application, two case studies are presented in this thesis. First of all, ParaFuse has been used to generate several cabin designs for the AAR cruiser, which has been developed by the faculty as part of the RECREATE project. A second case study has been performed to evaluate the fuselage design of a regional turboprop aircraft. The development of ParaFuse, together with the implemented fuselage sizing and cabin configurationmethods, described in this thesis is a step towards a next generation aircraftMulti-Model Generator.Aerospace EngineeringAerodynamics, Wind Energy & PropulsionFlight Performance and Propulsio
Using Genetic Algorithms for Underground Stope Design Optimization in Mining: A Stochastic Analysis
No full textMine design and mine planning are essential to a mining operation as they do not only dictate the outline of the mine, but essentially determine the financial robustness and success of the mining operation. However, as mining is a conservative business mine design is still mostly done by hand. To indicate the effect of uncertainty in mine design, Vallee (2000) reported that 60% of the reviewed mines had an average production rate that was 30% lower than their designed capacity. To provide in better mine design researchers and companies have developed and proposed number of guidance tools in recent years to help optimize mine planning. However their efforts have mainly focussed on open-pit mine design whilst largely ignoring underground mining, which is more versatile and therefore more difficult to assess. Furthermore, the optimization algorithms that have been developed are mostly based on average-type or interpolated resource models, which do not allow assessing uncertainty. Several stochastic approaches have been proposed by Dimitrakopoulos and others as a tool to involve stochastic techniques in mine design optimization as a way to assess uncertainty. However, few practical stochastic solutions have been developed for underground mine design. To contribute to the recent efforts made by the TU Delft in the ‘Horizon 2020 – Real Time Mining’ European Union Research and Innovation Programme, this research has focussed on combining underground mine design optimization with several stochastic analyses. A stope layout optimizer was developed in Matlab based on standard genetic algorithms, a sub-group of evolutionary algorithms. This model was tested on two validation data sets where it showed good optimization performance. A stochastic optimization module was added and tested, but as the validation data set was linear, it showed no added value. Using a resource model of a copper / zinc VMS deposit a number of stochastic approaches were tested. By performing a minimal downside risk / maximum upside potential analysis a stochastic optimization and elimination approach was tested under different economic scenarios by using 20 unconditional economic block model simulations. A stochastic risk analysis using the same 20 economic block models was done to study the effect of stochastic probability on economic value, ore tonnage, waste tonnage, average ore grade and average arsenic content. Lastly, a stochastic design optimization was done using 100 unconditional economic block models and its optimization performance was compared to that for a traditional non-stochastic optimization. Both the minimal downside risk / maximum upside potential analysis and the stochastic design analysis showed better optimization results than traditional optimization using average type orebody models. However, as in the min / max approach emphasis was on robustness instead of profitability, it was unable to show the same degree of improvement over traditional optimization.Civil Engineering and GeosciencesGeoscience & EngineeringResource Engineerin
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Simulation of LSI-11/PDP-11 series minicomputers. [Runs on IBM 370]
No full textA functional simulation of te PDP-11 series minicomputers was implemented to run either interactively or as a batch job on an IBM 370 computer. The simulator operates in two modes, the supervisor mode and the run mode. In the supervisor mode, the simulator implements a command language, which allows users to examine and change the contents of memory or other addressable registers in the simulated machine. Optionally, an instruction trace may also be turned on or off. In the run mode, the simulation of the instruction set is tested by successfully running DEC's MAINDEC basic instruction test on the simulated machine. The interrupt structure is modeled. The simulation is open ended in the sense that users may define new peripheral devices, by including their own FORTRAN callable subroutines for each simulated device. Currently the following devices are supported: floppy disks, a console terminal, a card reader, a card punch, a line printer, and a communications multiplexer (DH11). With these devices DEC's RT-11 versions 2C and 3B have been successfully run on the simulator. At SLAC this simulator is proving useful in debugging software for one-of-a-kind hardware configurations, such as communications front end processors, that are not readily accessible for stand alone testing. 5 figures
What is the Internet doing? Performance and reliability monitoring for the HEP community
No full textA Search for Parity Violation in the Inelastic Scattering of Polarized Electrons from Deuterium at 19.4-GeV
No full textPrescott CY, Atwood WB, Cottrell RLA, et al. A Search for Parity Violation in the Inelastic Scattering of Polarized Electrons from Deuterium at 19.4-GeV. In: Bogolyubov NN, Dzhelepov VP, Kadyshevsky VG, et al., eds. Proceedings, XVIII International Conference on High-Energy Physics Volume 2: July 15-21, 1976 Tbilisi, USSR. 1976: B55-B56
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What is the Internet doing for and to you?
No full textMany HEP sites have been participating in a project to monitor end-to-end Internet performance. A few sites have acted as central collection, analysis and report generation points for the large amount of data generated. The reports are useful for short term trouble identification, long term projections, and the evaluation of Internet services. The work is illustrated by examples of both detailed and more general Internet performance
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Network management and performance monitoring at SLAC
No full textThe physical network plant and everything attached to it, including the software running on ``computers`` and other peripheral devices is the {bold system}. Subjectively, the ultimate measurers of {bold system} performance are the users and their perceptions of the performance of their networked applications. The performance of a {bold system} is affected by the physical network plant (routers, bridges, hubs, etc.) as well as by every ``computer`` and peripheral device that is attached to it, and the software running on the computers and devices. Performance monitoring of a network must therefore include computer systems and services monitoring as well as monitoring of the physical network plant. This paper will describe how this challenge has been tackled at SLAC, and how, via the World Wide Web, this information is made available for quick perusal by concerned personnel and users
