Multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) technology has been used widely in many wireless communication systems. Signals will be distorted when they are transmitted in wireless channels. For the reason that wireless channel is time or location variant, we have to estimate the channel impulse response and use the channel state information to compensate the channel distortion. Pilot signals can be spaced separated in the transmitted symbols. In the receiver, the channel impulse response can be estimated at the positions of pilot signals. The other channel information at the data signals can be obtained by interpolating the estimated channel impulse response. However, error caused by channel interpolation can not be avoided. In this paper we propose a pilot-aided iterative maximum likelihood (ML) channel estimation algorithm for MIMO OFDM systems. At first, an ML channel estimate is obtained by using pilot tones. The receiver uses the estimated channel to help the detection/decision of data signals. And then the channel estimation treats the detected signals as known data to perform a next stage channel estimation iteratively. By utilizing the iterative channel estimation and signal detection process we can reduce the estimation error caused by channel interpolation between pilots. The accuracy of the channel estimation can be improved by increasing the number of iteration process. Simulation results demonstrate the iterative ML channel estimation algorithm can provide better mean-square-error and bit-error-rate performance than conventional methods. By changing the system parameters we can see that the improvement provided by this algorithm is different. Systems with fewer pilots have more improvement from the iterative ML algorithm. On the other hand, systems with more pilots have less improvement from the iterative algorithm. Finally, several channel environments are also considered in this thesis to compare the performance improvement introduced by the iterative algorithm.

Abstract Equal channel angular extrusion (ECAE) has been used to investigate the formation of submicron grain structures in copper deformed to ultra-high plastic strains by different die angles, deformation routes, and deformation temperatures. The result was characterized by the use of transmission election microscopy (TEM), and the evolution of the deformed Cu depended on several parameters such as die angle, deformation route, and deformation temperature. It has been demonstrated that the most effective method of forming high angle boundaries and recrystallized grains by severe plastic deformation is to rotate billets with a constant clockwise 90o between each pass (route BC) via a 90o die angle. Besides, the temperature effect on the microstructural evolution is studied. With increasing deformation temperature, the microstructure becomes more homogeneous because the climb and the cross-slip of dislocations are easier at higher temperatures, and the fraction of high angle boundaries, recrystallized grains and size of them are increased significantly with the deformation temperature. In addition, the thermomechanical process was also investigated in the present work. It is suggested that a uniform submicron grained structure could be obtained by increasing the deformation temperature and decreasing the intermediate annealing temperature to promote dynamic recovery and to inhibit discontinuous recrystallization.

The growing Internet is more and more important, which affects our society significantly, and leads to the revolutions of industry, like economy of Internet and economy of knowledge. The main theories of this dissertation are concerning on the concepts of the ¡§Diffusion of Innovations¡¨ and ¡§Organization Communication¡¨. The purpose of this dissertation is to research the diffusion of communication channels of Internet, and hope to explore whether the traditional theories can apply to the Internet web site or not. The object of the research is a web site on Internet named ¡§Loxa¡¨, the URL of which is ¡§http://www.Loxa.edu.tw¡¨. The methods of collecting data are to interview change agent and users of Loxa web site. This dissertation has some conclusions. First, the communication channels of Loxa web site still follow traditional theories of diffusion. Second, the communication channels of Loxa web site are ¡§missive¡¨, ¡§seminar¡¨, ¡§catalog¡¨, ¡¨interpersonal communication¡¨. Third, the core networks of diffusion of Loxa web site is focused on the information-teacher who manages the equipments of computer software and hardware.

This dissertation considers three different aspects of modern digital communication systems and is therefore divided in three parts. The first part is distributed coding. This part deals with source and source- channel code design issues for digital communication systems with many transmitters and one receiver or with one transmitter and one receiver but with side information at the receiver, which is not available at the transmitter. Such problems are attracting attention lately, as they constitute a way of extending the classical point-to-point communication theory to networks. In this first part of this dissertation, novel source and source-channel codes are designed by converting each of the considered distributed coding problems into an equivalent classical channel coding or classical source-channel coding problem. The proposed schemes come very close to the theoretical limits and thus, are able to exhibit some of the gains predicted by network information theory. In the other two parts of this dissertation classical point-to-point digital com- munication systems are considered. The second part is quantization of coded chan- nel measurements at the receiver. Quantization is a way to limit the accuracy of continuous-valued measurements so that they can be processed in the digital domain. Depending on the desired type of processing of the quantized data, different quantizer design criteria should be used. In this second part of this dissertation, the quantized received values from the channel are processed by the receiver, which tries to recover the transmitted information. An exhaustive comparison of several quantization cri- teria for this case are studied providing illuminating insight for this quantizer design problem. The third part of this dissertation is faster-than-Nyquist signaling. The Nyquist rate in classical point-to-point bandwidth-limited digital communication systems is considered as the maximum transmission rate or signaling rate and is equal to twice the bandwidth of the channel. In this last part of the dissertation, we question this Nyquist rate limitation by transmitting at higher signaling rates through the same bandwidth. By mitigating the incurred interference due to the faster-than-Nyquist rates, gains over Nyquist rate systems are obtained.

The MotA and MotB proteins of E. coli form a MotA4MotB2 complex. Proton flow through a transmembrane channel in the complex powers flagellar rotation. Protonation of Asp-32 of MotB within the channel is proposed to cause a conformational change in the large cytoplasmic loop of MotA, which pushes against FliG in the rotor. MotB is believed to anchor the complex to the cell wall via a conserved sequence that is found in many proteins that bind peptidoglycan. The research presented in this dissertation focused primarily on the formation and activation of the MotAB proton channel. A proposed amphipathic α-helical region, extending from residue 52 through 65 of the periplasmic domain of MotB, was discovered to block proton flow through the channel in its inactive state prior to incorporation into a flagellar motor. The plug is thought to lie parallel to the periplasmic face of the cell membrane and to be removed from the membrane by a conformational change triggered by contact with the motor. Negatively charged residues near the cytoplasmic C-terminus of MotA and positively charged residues at the cytoplasmic N-terminus of MotB were identified as being important for motility. A mutational analysis and subsequent suppressor analysis suggest that these residues may align MotA and MotB to form the MotA4MotB2 complex in the proper position relative to FliG and the rotor. The underlying mechanism for producing MotA and MotB in a 2:1 ratio was also investigated and found to be primarily due to translational coupling of motA and motB. The stop codon of motA and the start codon of motB overlap, allowing the ribosome that has just completed translation of motA to reinitiate and translate motB. The efficiency of reinitiation is about 66%; presumably degradation of excess MotB not in the MotA4MotB2 complex produces the final 2:1 ratio. Research was also conducted to determine whether MotB binds directly to the peptidoglycan layer of the cell wall. Although inconclusive, the preliminary results appear to support this notion. The overall work provides insights into several aspects of the assembly and subsequent activation of the stator component of the bacterial flagellar motor.

¡§The Wal-Mart Effect¡¨ indicates how Wal-Mart impacts the stakeholders such as employees, supplier, community and the environment when it becomes one of the biggest companies in the world. The effect on its suppliers is not only confined to the regular transaction relationship, but also their decision making. Even the Procter and Gamble, the giant company of consumer goods, has to increase its bargaining power to Wal-Mart by merging other brands. The ¡§mass selling¡¨, which was first introduced into Taiwan by foreign hypermarket in the 1980s¡¦ impacts the original retailing business of Taiwan. After being entering and withdrawing by several companies, the hypermarket business in Taiwan is now mainly dominated by three companies, Carrefour, RT-Mart and FE-Geant, which have fierce price competition between one another. This study attempts to find out whether the bargaining power of the hypermarketers to their suppliers is increased these years as well as the effect of this power to their suppliers by using the case-study method. We interviewed one hypermarket company and several suppliers of hypermarket companies in order to know their content of transaction. It is found that the hypermarket industry in Taiwan decayed in recent years, but the dominant companies, such as Carrefour, still has an increasing power to their suppliers. This increasing power reflects mainly on its imposition of sales commission and promotion fee. Besides, hypermarket retailers have more power to affect the smaller suppliers¡¦ the decision making of products. From the cases that are discussed in this paper, it¡¦s also found that the smaller suppliers would avoid price-competition of the hypermarket retailers by supplying products with few differences in specification. However, these suppliers should pay more attention to their cash flow to ensure their ability to contract with hypermarket retailers which usually have strict payment conditions.

Abstract Insurance Marketing Channel is a form of media which is known for delivering insurance products directly from Insuers to the Consumer. Though the banking and insurance industries are in the same finacial field. However, the gap between them has become more and more pronounced. A major cause for this is related to the fact that regulations are being de-regulated and gradually unchained by individual conturies. The reasons why the Bancassurance marketing channel has become one of the insurance industry¡¦s most important marketing channel is due in large part to a series of reforms in the financial field which took place soon after Taiwan joined the WTO. These reforms have also boosted the profile of Bancassurance and made it directly important, especially after the enactment of the ¡§Financial Holding Company Act¡¨ of 2001 and ¡§ Rules for jointly promoting products or providing related service¡¨ of 2003 by the Financail Supervisory Commission. Due to the bank, insurance, and securities companies cross-integration into X-selling, to satisfy one-stop shopping needs of clients; these industries have come together to form the strategic alliance of Bancassurance. From bank company¡¦s viewpoint, they can earn more risk-free fee income by way of selling insurance products to ease the pain of the negative spread from red ocean banking environment. From insurance company¡¦s point of view, they can leverage the banking industry¡¦s large customer basis and their massive branch banking network to significantly cut their basic unit selling cost through the massing capabilities of Bancassurance Marketing Channel. From the consumers viewpoint they can reduce the cost or broad spectrum saerching and better satisfy their one-stop shopping needs. After the ¡§Financial Holding Company Act¡¨ was put into effective, Financial Holdings can possess subsideries like bank, insurance companies (both life or general insurance), and securities companies to better serve their client¡¦s one-stop shopping needs. This represent a far greater challenge to those insurance companies who do not have the background of or access to the resourances that Financial Holdings can offer, forming a barrier that makes it difficult for those above mentioned insurance companies to enter into the Financial Holings Bancassurance marketing channel. Based upon this, my reaserch will present a case study and in-depth interviews of high level banking and insurance company executives who are, themselves, in charge of Bancassurance business, and I will also look into a general insurance company with a non-Financial Holdings background to explore how it can develop its Bancassurance channels. Due to the emergence of Bancassurance, Market Channels are widely successful and advanced in many western countries, and are also well-developed in the life insurance industry here in Taiwan. The traditional way of marketing in the general insurance is by way of solicitors; however, the quantity of solicitors is less than that of life insurance industry. In this regard, it is very important for the non-financail holding, general insurance companies to properly leverage the advantage of the bankingindustries¡¦ island-wide branches and their good relationship with their clients to make this strategic alliance and truly reach a win-win-win synergy between banks, general insurance companies and consumer. Keyword: Bancassurance, Market Channel

The direct sequence ultra-wideband (DS-UWB) system has the characteristics of low transmission power constraints and wide transmitted bandwidth. The wide bandwidth will introduce fine timing resolution and severe inter-symbol interference (ISI), which will is cause larger delay spread. Therefore, the traditional acquisition methods are no longer suitable here. A modified acquisition method and a coarse channel estimation algorithm are proposed in this thesis. Three different strategies with composition of acquisition and channel estimation are compared. Based on three strategies, the tasks of coarse acquisition and channel estimation can be achieved with limited length of acquisition sequence. From simulation results, the parallel strategy is robust enough to operate under the UWB channel in severe ISI conditions and the time duration for completing the tasks of coarse acquisition and channel estimation meets the specification of IEEE 802.15.3a.

In the era of lacking raw materials, the energy and resources are getting precious; these factors raise our concern on environmental protection issues and take good care of the only earth. Resource recycling has been built in our daily life, as a result. Upon government¡¦s initiatives and policies, what private sectors can play to maximize the impact? We believe the structure of ¡§recycling channel¡¨ is the most effective operational model with speed. And it will retrieve the valuable resources from consumers, eventually distribute to related industries for recycling. This study targets on Taiwan first island-wide resource recycling channel firm¡¦s innovative business model, and his competition strategy to extend his coverage in mainland China. We analysis and compare the business model and core competence between two firms with different background and industry¡¦s characters Our target firm has been in the business for 8 years, however it still lacks of experience or cases that is similar to our assumption. Our methodology is to interview with experts, review theories, study target firm¡¦s management system, and correlate with my own experience in this industry. We adopt SWOT, Porter¡¦s Five-Force Analysis, Strategy Matrix, and strategy structure to be the framework for this research. We try to propose a solution to target firm for the possible business strategy adjustment, and study the feasibility of copying Taiwan experience onto China. After SWOT analysis, the case company has the competitive advantage of ¡§management system, IT solution, and quality talents¡¨. In order to enlarge the business scale, business strategy should be shifted from ¡§market penetration¡¨ to ¡§diversification¡¨ gradually. To allocate organizational resources align with weighted growth strategy, and utilize current products and services to serve new markets. In the future, the company can move onto the strategies of ¡§sales development and training, seeking alliance inside or outside recycling industry, creative and customized service model, and market segmentations¡¨. To sum up, the case company should choose ¡§differentiation strategy¡¨, and to be recognized and supported by customers. This is the way to avoid price war and secure the profits. Without protection by government resources and policies, Taiwan experience can¡¦t be transplanted to China, due to the nature of different political situation and culture gap.

The mechanism of action of notexin in the facilitation of spontaneous transmitter release at neuromuscular synapse was investigated in Xenopus cell culture by using whole-cell patch clamp recording. Exposure of the culture to notexin dose-dependently enhanced the frequency of spontaneous synaptic currents (SSCs). Either buffering of intracellular Ca2+ rise by BAPTA or replacing culture medium with Ca2+-free Ringer¡¦s solution effectively hampered notexin effect, suggesting Ca2+ influx is requisite for this facilitation. Pretreatment of the cultures with a TRP channel inhibitor SKF96365, instead of voltage-dependent L-type Ca2+ channel blockers nifedipine or verapamil, significantly abolished the SSC facilitating effect of notexin. Furthermore, knockdown the expression of TRPC channels by TRPC-specific morpholino abruptly abolished notexin effect, suggesting that TRPC channel is the major entranceway of extracellular Ca2+. The notexin-enhanced SSC frequency was also obviously reduced under intracellular Ca2+ store depletion by pretreatment of the cultures with pharmacological Ca2+-ATPase inhibitor thapsigargin or CPA. Bath application of membrane-permeable inositol 1,4,5-triphosphate (IP3) inhibitor, XeC, effectively occluded the facilitation of SSC frequency elicited by notexin. Furthermore, notexin-induced SSC frequency facilitation was blocked in the presence of phospholipase C (PLC) inhibitor, U73122. Taken collectively, these results suggest that notexin elicits a Ca2+ release from the IP3-sensitive intracellular Ca2+ store which resulted in further store depletion-operated Ca2+ influx through membrane TRPC channels of the presynaptic nerve terminal. This is done via PLC signaling cascade, leading to an enhancement of spontaneous transmitter release. Notexin-induced synaptic facilitation is potentially reduced while structural modification with phenylglyoxal. In addition, bath application of PLA2 inhibitor either aristolochic acid or glycyhirrzin effectively abolished notexin effect, suggesting the PLA2 activity is involved in notexin-induced SSC frequency facilitation. Previously it has been suggested local accumulation of PLA2-induced lipid metabolites myristoyl lysophosphatidylcholine (mLPC) and oleic acid (OA) promotes the fusion of the hemifused synaptic vesicles with plasma membrane, hence facilitating the neurotransmitter release in cultured cerebella granular neurons and thus resulted in bulges formation along the neurite. Our real-time morphometric analysis and synaptic activity assays showed that bulges formation along the neurite appeared significantly earlier and was induced at lower notexin concentrations than synaptic activity facilitation. Bath application of either mLPC, OA alone or their mixtures failed to mimic the notexin-induced facilitation in spontaneous transmitter release. Attenuation of PLA2 activity by chemical modification (notexin-80) resulted in correlated decrease of notexin-induced synaptic facilitation but not the degenerative morphological sign. Moreover, PLP-notexin, a site-specific modification of notexin with full intact PLA2 activity, shows significant loss the ability of notexin-induced neurite degeneration. Overall, results from our studies suggest the morphologic changes and synaptic facilitating effect induced by notexin are resulted from different cellular mechanisms.