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- Bengtsson, PerOlof
(author)
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Design and Evaluation of Software Architecture
- 1999
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Licentiate thesis (other academic/artistic)abstract
- The challenge in software development is to develop software with the right quality levels. The main problem is not to know if a project is technically feasible concerning functionality, but if a solution exists that meet the software quality requirements. It is therefore desired to get an early indication of the qualities of the resulting software. Software architecture is concerned with what modules are used to compose a system and how these modules are related to each other, i.e. the structure of system. The software architecture of a system sets the boundaries for these qualities. Hence, to design the software architec-ture to meet the quality requirements is to reduce the risks of not achieving the required quality levels. In this thesis we present the experiences from a software architecture design project with two industry partners. Based on these we propose a method for reengineering architectures and exemplify by an applying the method on a real world example. The method is based on architec-ture transformations and software quality evaluation of the architecture. Further, we present a method for predicting software maintenance effort from the software architecture, for use in the design and reengineering method. The method uses change scenario profiles to describe future changes to the system and architecture impact analysis provide knowl-edge of the modification volume required for the realization of each sce-nario. The results from a quasi experiment supports that groups consisting of prepared members create better scenario profiles. Also, the results suggest that there is a large room for variation between scenario profiles created by individual persons.
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| 2. |
- Dahl, Mattias
(author)
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Acoustic Noise and Echo Cancelling : Microphone Array Methods and Applications
- 1997
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Licentiate thesis (other academic/artistic)abstract
- This Licentiate thesis is divided into three parts corresponding to three different papers. There is one research report, one conference paper and one submitted journal paper. All three parts deal with acoustic echo and/or noise cancelling problems when using adaptive microphone arrays. In particular, the papers address the performance of an adaptive microphone array in a small enclosure such as the car cabin. A calibrating scheme is proposed which is independent of array geometry and channel matching, and which calibrates the adaptive array to the given acoustic environment and to the given electronic equipment. Results from real measurements in a car interior are included and compared with an analytical description of an adaptive microphone array. Part A gives an analytical description of an adaptive microphone array which facilitates a simple built-in calibration to the environment and instrumentation. Part B describes the method for performing acoustic echo cancelling with a dig-ital "on-site", "self-calibrating" microphone array system. The calibration process is a simple indirect calibration which continuously adapts to the actual environment and electronic equipment. There is a US patent based on this part and an international patent is currently under examination. Part C presents a neural network based microphone array system, which is capable to continuously perform speech enhancement and adaptation to nonuniform quantization, such as A-law and µ-law.
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- Larsson, Tobias
(author)
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Effective development of dynamic systems : a structured approach
- 1999
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Licentiate thesis (other academic/artistic)abstract
- This licentiate thesis deals with effective simulation of multibody dynamic systems in the product development process. Previous work to make simulation more effective has concentrated on developing faster calculation methods. Instead, this approach is to make the process of multibody dynamics simulation more effective by structuring of products, simulation models and their usage. Efforts have been made to clarify how computer tools are used in product development in industry today. Insight into the two domains of product development and multibody dynamics is given. These domains have traditionally been separated but the introduction of concurrent engineering and faster computers puts new demands on the integration of computer support and analysis in the development process. A proposal for performing the multibody dynamics methodology in a modular way in the product development process is given based on the performed work.
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