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本文旨在檢視口語活動時，構思時間對第二語言學習者口語表達之影響，進而探討學生如何運用構思時間，期許對學生構思時的認知過程有所了解，並對教師進行口語相關活動時有教學上的啟示。 本研究以構思時間的不同將實驗學生分為四組：(1) 無構思、(2) 活動前構思、(3) 活動時構思、(4)活動前及活動時構思。探討四組學生語言表達流利度、複雜度、及正確度的差異。實驗結果顯示活動前構思有助於語言表達流利度，活動時構思則有損語言表達流利度。活動前構思傾向增加語言表達複雜度，但活動時構思一組則未顯現清楚影響。正確度方面，四組中只有活動前及活動時構思一組略有助益。由此推論學生首先利用構思時間構思口語表達之內容，語言正確度則需在學生認知處理時間及能力許可時，方能兼顧。此外，本研究發現口語活動困難度、學生語言能力及口語習慣均影響了構思時間對語言表達複雜度及正確度所造成的影響。 / Previous research on the impact of planning on L2 learners’ oral production has lent general support to the claim that pre-task planning facilitates the fluency and complexity aspects of oral production. However, due to lack of consistency in methodology, there has not been a conclusive result of the effects of planning. Besides, mixed results have been found for language accuracy. It remains uncertain whether pre-task planning or on-line planning enhances accuracy. The purpose of this study was to investigate the effects of both pre-task planning and on-line planning on the fluency, complexity and accuracy aspects of oral production. In this study, 40 participants were asked to narrate a picture story and were divided into groups under four conditions: (1) no-planning, (2) pre-task planning, (3) on-line planning, and (4) pre-task planning plus on-line planning. The results showed that pre-task planning improved fluency while on-line planning impeded fluency. Pre-task planning showed a tendency to facilitate complexity while on-line planning did not. It was also found that neither pre-task planning nor on-line planning evidently contributed to accurate language use. This finding contradicts with previous research which claimed that accuracy was more dependent on on-line planning. It appears that during on-line planning time, participants’ first priority remains the propositional content of the oral production. Most of the results in this study fail to reach statistical significance. It may be due to the task difficulty and participants’ proficiency level. The impacts of these two variables on the results of planning studies are in need of more future research.

For life insurance and annuity products whose payoffs depend on the future mortality rates, there is a risk that realized mortality rates will be different from the anticipated rates accounted for in their pricing and reserving calculations. This is termed as mortality risk. Since mortality risk is difficult to diversify and has significant financial impacts on insurance policies and pension plans, it is now a well-accepted fact that stochastic approaches shall be adopted to model the mortality risk and to evaluate the mortality-linked securities. The objective of this thesis is to propose the use of a time-changed Markov process to describe stochastic mortality dynamics for pricing and risk management purposes. Analytical and empirical properties of this dynamics have been investigated using a matrix-analytic methodology. Applications of the proposed model in the evaluation of fair values for mortality linked securities have also been explored. To be more specific, we consider a finite-state Markov process with one absorbing state. This Markov process is related to an underlying aging mechanism and the survival time is viewed as the time until absorption. The resulting distribution for the survival time is a so-called phase-type distribution. This approach is different from the traditional curve fitting mortality models in the sense that the survival probabilities are now linked with an underlying Markov aging process. Markov mathematical and phase-type distribution theories therefore provide us a flexible and tractable framework to model the mortality dynamics. And the time-changed Markov process allows us to incorporate the uncertainties embedded in the future mortality evolution. The proposed model has been applied to price the EIB/BNP Longevity Bonds and other mortality derivatives under the independent assumption of interest rate and mortality rate. A calibrating method for the model is suggested so that it can utilize both the market price information involving the relevant mortality risk and the latest mortality projection. The proposed model has also been fitted to various type of population mortality data for empirical study. The fitting results show that our model can interpret the stylized mortality patterns very well.

HMS Industrial networks is a company that offers communication solutions for automation systems. There exists an abundance of different industrial network technologies and HMS manufactures gateways that translate and allow communication between the different networks.The multiplicity of network technologies introduces problems when it comes to monitoring the processes in an automation system. It is desirable to be able to access the process data through a single network technology and this is what OPC UA is used for. Briefly, OPC UA can be described as an interface for exchange ofprocess data in automation systems. HMS has noticed a rising trend in the interest for OPC UA and therefore wants to investigate the possibility to use OPC UA on their platform, the Anybus X-Gateway. The goal of this thesis has been to port an OPC UA stack, provided by the OPCfoundation, to the HMS operating system running on an Anybus X-Gateway. The port has been successful and has been verified by unit tests and a test application. Thus, a first step towards a complete OPC UA product has been taken. Further, the thesis presents a theoretical summary about real-time operating systems to explain their function and usage.

In this thesis an audio and video streaming system is implemented for its use in rescue robots. WebRTC technology is used in order to stream in real time. Implemented in an architecture based on a Web server, two pages running WebRTC and a TURN1-STUN2 server, the system has been tested in terms of CPU and bandwidth utilization. Measurements show that when WebRTC is run in an Intel Core i3, less than 10% of CPU is used, whereas on smaller tablets the performance is not enough for running the application with the desired quality of service.

Although Annie Dillard has frequently written about the subject of time, no serious study of her treatment of this subject has been published. The purpose of this study was to open the conversation, particularly in the light of her recent book, For the Time Being.Dillard's strongest interest in time is in the relationship between the temporal, time here and now, and the eternal, generally located sometime in the future, somewhere other than here. Since Dillard has repeatedly alluded to this subject in her previous nonfiction books, one may trace the development of her concept of time and eternity from earlier works such as Pilgrim at Tinker Creek, Teaching a Stone To Talk, and Holy the Firm, to its current expression in For the Time Being. She places her questions about time and eternity in a distinctly down-to-earth spirituality informed by modern science and sharpened by pungent humor.Beginning with an analysis of the influence on Dillard's writing of Romantics such as Wordsworth and Transcendentalists such as Thoreau but more particularly Emerson, as well as ancient Judaic thought, this study focuses on how Dillard blends with these theinfluence of twentieth century Christian theologian-philosophers such as Alfred North Whitehead and Teilhard de Chardin to form an eclectic spirituality that is distinctly her own.Though Dillard has often been called a mystic, her spiritual quest is intensely practical and purposeful: by cracking open the mystery of time she intends to discover nothing less than the secrets of God. This study concludes that Dillard is calling readers to recognize that the spiritually alive person can transcend the barriers of the temporal, experience the eternal in the present, and participate with God in the redemption of the universe. / Department of English

Wireless designers constantly seek to improve the spectrum efficiency/capacity, coverage of wireless networks, and link reliability. Space-time wireless technology that uses multiple antennas along with appropriate signalling and receiver techniques offers a powerful tool for improving wireless performance. Some aspects of this technology have already been incorporated into various wireless network and cellular mobile standards. More advanced MIMO techniques are planned for future mobile networks, wireless local area network (LANs) and wide area network (WANs). Multiple antennas when used with appropriate space-time coding (STC) techniques can achieve huge performance gains in multipath fading wireless links. The fundamentals of space-time coding were established in the context of space-time Trellis coding by Tarokh, Seshadri and Calderbank. Alamouti then proposed a simple transmit diversity coding scheme and based on this scheme, general space-time block codes were further introduced by Tarokh, Jafarkhani and Calderbank. Since then space-time coding has soon evolved into a most vibrant research area in wireless communications. Recently, space-time block coding has been adopted in the third generation mobile communication standard which aims to deliver true multimedia capability. Space-time block codes have a most attractive feature of the linear decoding/detection algorithms and thus become the most popular among different STC techniques. The decoding of space-time block codes, however, requires knowledge of channels at the receiver and in most publications, channel parameters are assumed known, which is not practical due to the changing channel conditions in real communication systems. This thesis is mainly concerned with space-time block codes and their performances. The focus is on signal detection and channel estimation for wireless communication systems using space-time block codes. We first present the required background materials, discuss different implementations of space-time block codes using different numbers of transmit and receive antennas, and evaluate the performances of space-time block codes using binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), and quadrature amplitude modulation (QAM). Then, we investigate Tarokh’s joint detection scheme with no channel state information thoroughly, and also propose a new general joint channel estimation and data detection scheme that works with QPSK and 16-QAM and different numbers of antennas. Next, we further study Yang’s channel estimation scheme, and expand this channel estimation scheme to work with 16-QAM modulation. After dealing with complex signal constellations, we subsequently develop the equations and algorithms of both channel estimation schemes to further test their performances when real signals are used (BPSK modulation). Then, we simulate and compare the performances of the two new channel estimation schemes when employing different number of transmit and receive antennas and when employing different modulation methods. Finally, conclusions are drawn and further research areas are discussed.

Pulse time modulation (PTM) techniques have drawn considerable attention over the years as suitable schemes for transmission of information over optical fibres. PTM schemes are known to utilise the vast optical bandwidth to provide efficient transmission characteristics. Pulse code modulation is one such modulation scheme that has been used widely in various communication systems. In this thesis digital pulse interval modulation (DPIM), a form of PTM, is proposed as a suitable modulation scheme for optical communication systems. In this scheme the information is represented by means of varying the anisochronous frame interval between two successive pulses. Each pulse fulfils the dual role of representing the frame boundaries and initiation of the next sampling event within the modulator or sample reconstruction in the demodulator. In this study DPIM frame structure is proposed and sampling criteria, information capacity, bandwidth requirements are discussed in depth. The spectral behaviour of the scheme is investigated and a mathematical model is developed to represent the spectra. The model was numerically evaluated and verified with the practical measurements to prove its validity. Spectral predictions were made for random as well as periodic information signals showing the existence of the distinct slot frequency component, which is used for slot synchronisation. Frame synchronisation is not required as DPIM has self synchronised frame structure. For random signals, slot component is found to be about 15 dB and for periodic single tone sinusoidal signal this was at about 5 dB. Dependency of this component on the various system parameters such as bit resolution, pulse width, pulse shape are discussed. A detailed account of the receiver performance is given. Receiver analysis was carried out for narrow band as well as for wide band channels. Possible error sources are presented and the system performance degradation with these error sources is discussed and a comparison is made with isochronous DPPM and PCM. For performance evaluation of analogue systems, signal-to-noise ratio was mathematically modelled and compared with PCM. This analysis showed that DPIM SNRs shows three important regions as compared to PCM. That is when the SNR is inferior, superior and identical to PCM performance. Threshold levels corresponding to the above regions vary depending on the system bit resolution. A prototype DPIM system was designed and implemented to transmit low speed analogue signal (≈15 kHz) at bit resolutions of 4, 5 and 6 where the slot frequencies are at 510, 990 and 1950 kHz, respectively. Measurements were carried out in order to verify the predicted performance. This results showed close agreement with the predicted. Receiver sensitivity of the prototype at bit error rate of 10^-9 was found to be about -45.5 dBm at all three cases with transmitted average power of -28.8 dBm allowing high optical power budget. The signal-to-noise ratio threshold level of the system was at -47 dBm. Finally, linearity measurements of the overall system were made at the above bit resolutions and the quantitative and qualitative results are presented.