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Taiwan is the country which relies on foreign trade and the value of import and export markets accounts for eighty percent of the Gross Net Product¡]GNP¡^. It is obvious that the feature of economic system in island highly depends on the existence of foreign trade. Therefore, exchange rate is considered as one of the major indexes for Taiwan¡¦s economic activities. Federal Reserve System¡]FED¡^has constantly begun to lower the interest rate for thirteen times since 2001, and this would influence the trends of the interest rate of the whole world. Also, it seems that reducing the interest rate promotes the low interest which leads to a more prosperous economy in Taiwan society than before. It is clear, thus, that the interest is regarded as a major variable in economic system. The stock market of Taiwan has shifted from bear market to bullish one since 2002 and it would have developed the bullish market for almost ten years. According to this phenomenon, the issue of how to evaluate the trend of the stock index has been becoming important for Taiwanese investors to explore the stock market. This study is based on the observation of the relationships between the stock index and the two rates, exchange and interest rates. It is hoping, by doing so, that investors can obtain sufficient information and successfully estimate different aspects of investing trends in the stock market in Taiwan.

Οι τεχνικές προσανατολισμένης λήψης έχουν μελετηθεί εκτενώς τις τελευταίες δεκαετίες, καθώς βρίσκουν εφαρμογή σε διάφορους τομείς. Ωστόσο, για σήματα ευρείας ζώνης το πρόβλημα αυτό δεν έχει διερευνηθεί διεξοδικά. Σκοπός αυτής της εργασίας είναι να αναδείξει τις δυνατότητες και τους εγγενής περιορισμούς των τεχνικών προσανατολισμένης λήψης. Στα πρώτα κεφάλαια παρουσιάζονται οι θεμελιώδεις έννοιες της επεξεργασίας σημάτων σε διατάξεις μικροφώνων και οι πιο ευρέως χρησιμοποιούμενες τεχνικές προσανατολισμένης λήψης. Στο τελευταίο κεφάλαιο πραγματοποιούνται εξοικειώσεις πραγματικών ακουστικών συνθηκών σύμφωνα με το πρότυπο ETSI EG 202 396. Το μη-ανηχοϊκό μοντέλο υιοθετείται και πραγματικά ακουστικά σήματα λαμβάνονται από γραμμικές διατάξεις μικροφώνων. Ακόμη, η τεχνική ημίτονου εκθετικής σάρωσης χρησιμοποιείται για την εκτίμηση της κρουστικής απόκρισης των Ν-ακουστικών καναλιών. Τέλος, το μοντέλο 3-QUEST χρησιμοποιείται για την μέτρηση της ποιότητας ομιλίας σε θορυβώδη περιβάλλοντα. / Beamforming techniques have been studied extensively due to its applications in various areas. However, most of the efforts have been focused on the narrowband case. For wideband signals, this problem has not been thoroughly investigated. This thesis aims is to highlight potentials and the limitations of the conventional beamforming techniques. In the first chapters, the fundamental array processing theory and the most widely used beamforming techniques are presented. In the last chapter, different real-world acoustic scenarios are simulated according to ETSI EG 202 396-3 standard. In the simulations, the reverberant model is assumed and real audio signals are captured by a linear microphone array. The coefficients of the spatial filter are computed with the MVDR criterion. Moreover, acoustic impulse responses measurements are presented and performed for the construction of the steering vector. The speech quality in presence of background noise is measured by the 3-QUEST model.