| 1. |
- Andersson, Carry, et al.
(författare)
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Dynamic Characteristics of a Tool Holder Shank in Lathe
- 2000
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Dynamic characteristics of a Tool Holder Shank were determined by using the Finite Element Method and Experimental Modal Analysis. Good agreement between FE-model and the experimental model was obtained for the Tool Holder Shank itself. With the Tool Holder Shank in Lathe the agreement was less good. Reasons for this are discussed. Suggestions for further work on including actuators to reduce vibrations are given.
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| 2. |
- Bengtsson, PerOlof, et al.
(författare)
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An experiment on creating scenario profiles for software change
- 2000
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Ingår i: Annals of Software Engineering. - BUSSUM : BALTZER SCI PUBL BV. - 1022-7091 .- 1573-7489. ; 9:1-4, s. 59-78
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Tidskriftsartikel (refereegranskat)abstract
- Scenario profiles are used increasingly often for the assessment of quality attributes during the architectural design of software systems. However, the definition of scenario profiles is subjective and no data is available on the effects of individuals on scenario profiles. In this paper we present the design, analysis and results of a controlled experiment on the effect of individuals on scenario profiles, so that others can replicate the experiments on other projects and people. Both scenario profiles created by individuals and by groups are studied. The findings from the experiment showed that groups with prepared members proved to be the best method for creating scenario profiles. Unprepared groups did not perform better than individuals when creating scenario profiles.
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| 3. |
- Bengtsson, PerOlof, et al.
(författare)
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Analyzing Software Architectures for Modifiability
- 2000
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The software architecture plays an important role in achieving a modifiable system, but few methods for modifiability analysis exist. In this paper, we propose an analysis method for software architecture modifiability that has successfully been applied in several cases. The method consists of five main steps, i.e. goal selection, software architecture description, scenario elicitation, scenario evaluation and interpretation.
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| 4. |
- Björklund, Svante, et al.
(författare)
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High Resolution Direction of Arrival Estimation Methods Applied to Measurements from a Digital Array Antenna
- 2000
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Ingår i: First IEEE Sensor Array and Multichannel Signal Processing Workshop (SAM 2000). - : IEEE Signal Processing Society. ; , s. 464-468
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Konferensbidrag (refereegranskat)abstract
- At the Defence Research Establishment of Sweden (FOA) an experimental S-band receiving digital array antenna for radar applications has been designed and built. It consists of a horizontal uniform linear array (ULA) of 12 antenna elements, whose digitized signals are processed in non-real time in a computer. Accurate calibration is utilized.We have compared several spectral and parametric direc- tion-of-arrival (DOA) estimation methods for varying DOA separations, number of samples and signal-to-noise ratios (SNR) on measured data from an anechoic cham- ber.At ideal conditions the resolution can be improved con- siderably with model based DOA methods compared to conventional beamforming. We achieved a resolution 1below /10 of the resolution of conventional beamforming.
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| 8. |
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| 9. |
- Broberg, Magnus
(författare)
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Performance tuning of multithreaded applications for multiprocessors by cross-simulation
- 2000
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Konferensbidrag (refereegranskat)abstract
- Performance tuning of a parallel application is often hard. The use of standards such as POSIX threads, makes it possible to move a multithreaded application from one platform to another. Doing performance tuning for many platforms is even tougher since the implementation of the standards may vary on different operating systems. The developer needs tools for analysing how the application will behave on different operating systems in order to do adequate performance tuning. In this paper we present a technique based on cross-simulation that will solve the issues above. The technique uses a monitored execution of a multithreaded application on a single processor workstation running the Solaris operating system. Then the technique, which has been implemented in a tool, simulates a multiprocessor with an arbitrary number of processors running either Solaris or Linux. The tool then displays the behaviour of the application on the selected target configuration. Validation, using a subset of the SPLASH-2 benchmark suite, shows that the tool predicts speed-ups correctly. The average error in the predicted speed-up when simulating Linux is 5.8%. All this can be done using the ordinary Solaris workstation on the developer's desk, without even having a multiprocessor.
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| 10. |
- Broman, Göran, et al.
(författare)
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Determining Dynamic Characteristics of Bellows by Manipulated Beam Finite Elements of Commercial Software
- 2000
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Ingår i: International Journal of Pressure Vessels and Piping. - Oxford : Elsevier Science. - 0308-0161 .- 1879-3541. ; 77:8, s. 445-453
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Tidskriftsartikel (refereegranskat)abstract
- A procedure for determining dynamic characteristics of bellows by manipulating certain parameters of the beam finite elements of I-DEAS Master Series 6 is presented. The method will work in any software in which these parameters can be set by the user. Compared to a shell elements model the model size is reduced by at least a factor of 100. This is especially advantageous when the bellows is only a part of a system to be optimised with respect to overall design parameters. Stress in the bellows cannot be predicted by this method, but when the dynamic behaviour is known it can be used as input for stress calculations, if desired. In contrast to existing "semi-analytical" methods this method has the potential of considering axial, bending and torsion degrees of freedom simultaneously, and it facilitates the interaction between the bellows and the rest of the system, also modelled by beam or shell finite elements. The procedure is verified by experimental results from other investigators.
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