Purchasing Power Parity (PPP) is an important theory of exchange rate determination. The documents probing into the PPP theory are voluminous nowadays; however, there hasn¡¦t been an agreed conclusion yet. In this paper, we apply the Panel Lagrange Multiplier unit root test, a newly developed panel unit root test that allows for heterogeneous breaks, under both the null and the alternative, in both the level and trend of the series under investigation, addressed by Im, Lee and Tieslau (2010). The validity of PPP theory can be examined by testing the stationary of real exchange rates. We use the data chosen from the countries of Asia, including Taiwan, Japan, Korea, Tailand, Indonesia, Hong Kong and Singapore to proceed the positive analysis. The result shows that no matter we use CPI or WPI as the price index, both considering more about the structure breaks and using the panel unit root test strongly support the PPP theory. And it also shows that when using the WPI as the price index, there would be much more countries support the PPP theory.

Cooperative communication has been shown that it is an effective way to combat the outage caused by channel fading; that is, it provides the spatial diversity for communication. Except for amplify-and-forward (AF) and decode-and-forward (DF), compressed-and-forward (CF) is also an efficient forwarding strategy. In this thesis, we proposed a new CF scheme. In the existing CF protocol, the relay will switch to the DF mode when the source transmitted signal can be recovered by the relay completely; no further compression is made in this scheme. In our proposed, the relay will estimate if the codeword in a block is succeeded decoded, choose the corresponding forwarding methods with LDPC coding; those are based on joint source-channel coding or compressive sensing. At the decode side, a joint decoder with side information that performs sum-product algorithm (SPA) to decode the source message. Simulation results show that the proposed CF scheme can acquire the spatial diversity and outperform AF and DF schemes.

Though erasure codes are widely adopted in high fault tolerance storage systems, there exists a serious small-write problem. Many algorithms are proposed to improve small-write performance in RAID systems, without considering the network bandwidth usage. However, the network bandwidth is expensive in cloud systems. In this thesis, we proposed an ECL-based (E-MBR codes, Caching and Logging-based) technique to improve the small-write performance without using extra network bandwidth. In addition, the ECL-based technique also reduces the delayed parity update and data recovery latency compared with the competing algorithm.

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With the enormous growing applications of mobile communications, how to reduce the power dissipation of wireless communication has become an important issue that attracts much attention. One of the key techniques to achieve low power transmission is to develop a powerful channel coding scheme which can perform good error correcting capability even at low signal-to-noise ratio. In recent years, the trend of the error control code development is based on the iterative decoding algorithm which can lead to higher coding gain. Especially, the rediscovery of the low-density parity-check code ¡]LDPC¡^has become the most famous code after the introduction of Turbo code since it is the code closest to the well-know Shannon limit. However, since the block size used in LDPC is usually very large, and the parity matrix used in LDPC is quite random, the hardware implementation of LDPC has become very difficult. It may require a significant number of arithmetic units as well as very complex routing topology. Therefore, this thesis will address several design issues of LDPC decoder. First, under no SNR estimation condition, some simulation results of several LDPC architectures are provided and have shown that some architectures can achieve close performance to those with SNR estimation. Secondly, a novel message quantization method is proposed and applied in the design LDPC to reduce to the memory and table sizes as well as routing complexity. Finally, several early termination schemes for LDPC are considered, and it is found that up to 42% of bit node operation can be saved.

The author used Put-Call-Futures Parity, Arbitrage-Free, Ex-ante Tests and Ex-post Tests to examine the arbitrage opportunity and market efficiency of the TAIEX index futures (TX) and the TAIEX index options (TXO) in this paper, during the period of December 24th, 2001 to December 31st, 2002. The author first, used daily closing prices to test for the existence of possible arbitrage opportunities. Second, she used ex-ante tests and arbitrage strategy to examine the arbitrage opportunity whether it exists or not with a time lag. Furthermore, The author classified the samples which exist ex-post arbitrage profit into five sub-samples according to call options positions belonging to near-the-money and far-from-the-money, futures positions belonging to positive basis and negative basis, markets belonging to bull markets and bear markets, and different margin requirement. She used ex-post and ex-ante tests to compare the results of over-all markets samples with the sub-samples, then, she also examined the results of included transaction cost or not. The major findings are as follows: 1. Whether taking into transaction cost or not, the TAIEX index futures and the TAIEX index options markets have arbitrage opportunity¡Aand so the markets unefficient. 2. The results of ex-ante tests and the average of arbitrage profit are positive for time to increase. 3. The long arbitrage strategy generates a higher arbitrage profit than the short arbitrage strategy. 4. The investors could proceed arbitrage profit during markets belonging to positive basis and bear market and low margin requirement.

Purchasing Power Party (PPP) has long been intensively studied in empirical researches. However, a unanimous conclusion has not been reached. As an alternative to a narrative literature review, this paper conducts a meta-regression analysis of a collection of thirty-three studies, in order to uncover the sources of variation in the empirical findings relating to PPP. We also test the validities of suggestions made by the narrative literature reviewers that the use of more years of data, more countries, more powerful tests, more general model specifications, and an allowance for non-linearity might mitigate the issue of PPP puzzle. We find that the proposition is true and that whether PPP holds in the long run mainly depends on the methodology employed, the regimes the data are sampled from, and the length of the sample of data that is used. When addressing the persistence of the deviations from PPP, it mostly depends on the methodologies adopted.

This paper reexamines the long-run real interest rate parity of the OECD countries by using the unit root test proposed by Ng and Perron (2001) and by the application of simulation to establish the small sample distribution under the null and the alternative hypothesis. By using the small sample distribution of the unit root statistics, we can make sure that first, size distortions are not the reasons contributing to the rejection of the fact that the alternative hypothesis is unit root. Second, the inference that the low power is not necessary causes the not rejecting the alternative hypothesis is correct. If still can not decide which distributions might cause the real interest difference series by comparing the unit root statistics and the relative location of the small sample distribution, we test that whether the series are asymmetric in those countries which we can not decide what kind of distributions they are by the threshold autoregression model proposed by Caner and Hansen (2001). Finally, the empirical results indicate that the RIPH holds in Australia¡BBelgium¡BCanada¡BFinland¡BFrance¡BGermany¡BJapan and Sweden whenever data frequency under linear time series model. Under quarterly data of Italy and United Kingdom and monthly data of Denmark, it turns out that the data have the traits of nonlinear time series model. Besides, the evidence of supporting the long-run real interest rate parity can not be reached and the phenomena that partial unit root exist in United Kingdom and Denmark.

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (p. 208-215).

Οι MLC NAND Flash μνήμες παίζουν πρωταγωνιστικό ρόλο για την αποθήκευση δε- δομένων, καθώς έχουν μεγάλη αποθηκευτική ικανότητα λόγω της μεγάλης πυκνότητάς τους, χαμηλό κόστος και χαμηλή απαίτηση σε ισχύ. Για τους λόγους αυτούς, έγινε εφικτό από τους σκληρούς δίσκους οδήγησης (HDDs) πλέον έχουμε περάσει στην εποχή των Solid State Drives (SSDs) που αποτελούν ένα μεγάλο βήμα για την αποθήκευση δεδομένων αποδοτικά και αξιόπιστα. Βέβαια η παρουσία λαθών στις MLC NAND Flash μνήμες, λόγω φαινομένων όπως η γήρανση του υλικού καθιστά απαραίτητη την εφαρμογή κωδίκων διόρθωσης λαθών (ECC) ώστε να διατηρηθεί η αξιοπιστία σε επιθυμητά επίπεδα. Σκοπός λοιπόν αυτής της διπλωματικής είναι αρχικά η ανάπτυξη ενός παραμετροποιήσιμου μοντέλου MLC NAND Flash μνήμης για την εξομοίωση εμφάνισης λαθών. Στη συνέχεια η χρησιμοποίηση soft-decision Low Density Parity Check (LDPC) κωδίκων για τη διόρθωση λαθών με τέτοι οτρόπο ώστε να παρατείνουμε το χρόνο ζωής της μνήμης και τελικά να υπολογίσουμε το Life Time Capacity που αποτελεί το συνολικό μέγεθος της πληροφορίας που μπορεί να αποθηκευθεί σε μία μνήμη καθ’όλη τη διάρκεια ζωής της. / --