This study use the hydrography and current data measured along a zonal transect across the Penghu Channel (PHC) during 1985-2003 to calculate through-flow, temperature and salt transports (Q, TT and ST), and analyze hydrographic transects and water masses variations through the PHC. The influence of the El Ni&#x00F1;o on the variations of temperature and salinity in the PHC is also investigated. The calculated Q is about 0 Sv (1 Sv = 106 m3/s) in winter, and the TT, ST, heat flux are amount to -0.005¡Ñ1015 W, -2¡Ñ106 kg/s, -1.6¡Ñ106 W/m2; during winter-spring period, the Q increases from 0.5 to 1 Sv as the northeast monsoon weakens, and the TT, ST, heat flux are amount to 0.052~0.113¡Ñ1015 W, 20~40¡Ñ106 kg/s, 16~35¡Ñ106 W/m2, respectively. The Q peaks to 1.5 Sv at the end of southwest monsoon in summer, and the TT, ST, heat flux are 0.162¡Ñ1015 W, 52¡Ñ106 kg/s, 53¡Ñ106 W/m2, respectively. The Q decreases rapidly from 1.5 to 0 Sv when the northeast monsoon intensifies in autumn, and the TT, ST, heat flux are 0.162~-0.005¡Ñ1015 W, 52~ -2¡Ñ106 kg/s and 53~ -1.6¡Ñ106 W/m2, respectively. The relationship between the through-flow transport and the wind stress is expressed as Q (Sv) = 1.37+5.58¡Ñwind stresses (N/m2). The correlation coefficient is 0.97. The water column is strongly stratified in summer and nearly well-mixed in the upper 100 m in winter. The major water masses are the colder and saline Kuroshio Branch Water and the warmer and less saline South China Sea Surface Water respectively in winter and summer. The correlation coefficients for the El Nino index, the Southern Oscillation Index, to the anomalies of depth averaged (< 50 m) temperature and salinity are 0.527 and -0.429, respectively, suggesting that temperature and salinity might be anomalous decrease and increase during the El Ni&#x00F1;o.

In this thesis, we investigate the performance of adaptive loading orthogonal frequency division multiplexing (OFDM) under Nakagami fading with maximal ratio combining (MRC) diversity at receiver. We not only expound the principles and structures of the system, but also analyze its performance of the lower bound on the average capacity under Nakagami fading. First, we defined the lower bound on the average capacity under Nakagami fading with ideal MRC diversity. Then, we fixed the values of bit error rate. A maximum rate adaptive loading strategy is derived for uncoded quadrature-amplitude-modulation modulated OFDM. Simple lower bound expressions are provided for average spectral efficiency of the maximum rate adaptive loading OFDM under Nakagami fading channel. Finally, the numerical results will be also shown.

In this thesis, a precoding scheme is proposed for channel estimation in orthogonal frequency-division multiplexing (OFDM) systems. The precoding scheme utilizes a special code matrix before the inverse fast Fourier transform (IFFT) at the transmitter. The row vectors of the matrix have constant amplitudes in both time domain and frequency domain. With the prcoding scheme, a semi-blind channel estimation method is proposed by using the characteristics of the row code sequences. In the proposed scheme, the channel frequency responses of all sub-carriers can be obtained by using only one pilot sub-carrier, and the proposed architecture can not only increase the data rate, but also avoid interpolation error in channel estimation. In addition, the normalized mean square error (NMSE) function is derived and parameters are optimized to improve system performance. The proposed precoding architecture and channel estimation scheme are shown to have better performances in bit error rate by conducting computer simulation experiments.

In this thesis, a modified Kalman filter is proposed for time varying channel estimation in orthogonal frequency division multiplexing (OFDM). The proposed scheme adopts pre-coding scheme and minimum mean squared error (MMSE) equalizer to improve system performance. By using pre-coding schemes, information can be protected by signal diversities, which prevent Kalman filter to disperse due to erroneous data signals. In this investigation, the proposed system architecture is verified by using simulation experiments. Simulation results demonstrate that the proposed schemes substantially improve system performances under verious channel conditions.

Abstract Since non-profit organizations (NPO) in Taiwan have been developing rapidly, they have to compete for the limited resources in the society. In the meantime, the depression has made the government increase its budget deficit so industry and people reduce their donation. Waiting for the donation can no longer cope with the service cost. Non-profit organizations (NPO) begin to learn to construct and apply commercial marketing channels, and think how to use the least resources, manpower and equipment to frame suitable marketing channels. Thus, they can get what they need and provide service to invite more people to attend public welfare so as to create the greatest value for the society. This is the motif of the research. The purpose of this research is to investigate the relativity between the service specialty of non-profit organizations and the variety and proficiency of marketing channels hoping to achieve the purposes. First, what are the differences between service characteristics and gaining resources of non-profit organizations in choosing marketing channels. Second, what are the contents and levels of marketing channels for non-profit organizations. Third, what are the proficiency orientations on raising resources and service promotion of the marketing channels chosen by non-profit organizations. This research adopted literature analysis and case studies. We chose eight non-profit organizations which provide the welfare for the mentally and physically challenged, the so called social charity groups, and interview them about the relations between their service and marketing. The results are as follows: 1. Marketing channels of non-profit organizations are similar. However, the differences of individual mission statement, service specialty and resources will influence their choice on major marketing channels. 2. To achieve missions with rare resources, singular and multiple marketing strategies are suitable for non-profit organizations 3. The construction of organization channels depends on the cooperation of outer organized systems. Therefore, the cooperation model among channel members will influence the effects of marketing channels. 4. Non-profit organizations have not established sound estimated mechanism on their chosen marketing channels for raising fund and service promotion. 5. Digital marketing channels are new marketing ones to be learned. At the end, this research makes a conclusion and gives some suggestions according to the analyzed discussions of the investigations above. We hope that it can provide a reference for marketing fellows in industry and non-profit organizations, and for further research. Keywords£ºNon-profit organizations (NPO)¡¢Marketing Channel

In mobile radio systems, the bandwidth of spread spectrum signals for CDMA system is very wide. If the bandwidth exceeds the coherence bandwidth of the channel, the signal is seriously distorted by the multiple propagation paths. The available bandwidth is divided into a lot of small parts in Multi-carrier-CDMA system. Selecting the number of subcarriers according to the environment of channel will make the bandwidth of spread spectrum signals smaller than the coherence bandwidth of channel. And then the system can overcome the question of multiple propagation paths. The performance of Multi-carrier CDMA system is sensitive to frequency offset. Frequency offset results from Doppler shift due to mobile movement, as well as from a mismatch between the carrier frequency of local oscillators at the transmitter and receiver. Consequently, the subcarriers¡¦ orthogonality are lost, causing Inter-carrier Interference (ICI). The interference of other subcarriers will make the error of estimated channel coefficients. Effect of frequency offset will lower the performance of the combing detector that needing channel estimated. In this thesis, we propose a method to correct the frequency offset. Using the relation of two continuous received signals to estimate the frequency and compensate it. We will analysis and compare this method in different condition. Simulation results will demonstrate the performance of this proposed method.

Abstract Wideband-CDMA (WCDMA) is a kind of third-generation wireless communication system. It can provide multi-rate services and fast transmission with wideband technology. To improve the solution of no enough wireless bandwidth currently, the 3G communication systems have been researched and developed in several leading countries recently. WCDMA adopts a kind of new spreading codes named Orthogonal Variable Spreading Factor codes (OVSF codes) that have advantages of dynamically variable rates and keeping orthogonality. OVSF codes can provide different data transmission rates by assigning codes with different lengths. By building a code tree, we can discuss some better schemes to assign available data rate. In this paper, we propose an efficient channel assignment scheme that can decrease the call blocking rate and complexity of channel reassignment procedure. Based on the properties of the binary code tree, we use code merge scheme to decrease channel reassignment rate and call blocking rate. This will efficiently improve the performance of channel assignment and spectral efficiency. Simulation results show that the proposed scheme has expected results.

This study investigates the turbulent heat transfer and friction in a trapezoidal channel with opposite walls roughened with transverse and v-shaped ribs. The roughened channel depicts the internal cooling passage of an aerofoil near the trailing edge. The various configurations investigated for this study are smooth channel, channel with 90° transverse ribs and channel with v-shaped ribs angled at 45°. The pitch-toheight ratio (P/e), rib height-to-hydraulic diameter ratio (e/Dh) and the aspect ratio (W/e) were maintained at 12, 0.1906 and 1, respectively. The configuration was tested for Reynolds number ranging from 7,000 to 40,000. The 45° rib was found to produce the maximum heat transfer and minimum pressure loss.

The availability of feedback in communication channels can significantly increase the reliability of transmission while decreasing the encoding and decoding complexity. Most of the applications like cellular telephony, satellite communications and internet involve two-way transmission. Hence, it is important to devise coding schemes which utilize the advantages of feedback. Most of the results in code designs, which make use of feedback, concentrate on noiseless and instantaneous feedback. But in real-time systems, the feedback is usually noisy, and is available at the transmitter after some delay. Hence, it is important that we characterize the gains obtained in this case over that of one-way channels. We consider binary erasure channels to keep the problem tractable. For the erasure channels with noisy feedback, we have designed and analyzed a concatenated coding scheme, which achieves lower probability of error than any forward error correcting code of the same rate. Hence, it is shown that even noisy feedback can be useful in increasing the reliability of the channel. We have designed and analyzed a coding scheme using Low Density Parity Check (LDPC) codes along with selective retransmission strategy, which utilizes the limited (but noiseless), delayed feedback to achieve low frame error rates even with small blocklengths, at rates close to capacity. Furthermore, our scheme provides a way to trade off feedback bandwidth for reliability. The complexity of this scheme is lower than that of a forward error correcting code (FEC) of same blocklength and comparable performance. We have shown that our scheme performs better than the Automatic Repeat Request (ARQ) protocol which makes use of 1 bit feedback to signal retransmissions. For fair comparisons, we have also incorporated the rate loss due to the bits which are fed back in addition to the retransmitted bits. Thus, we have shown that for two-way communications with complexity and delay constraints, it is better to utilize the availability of feedback than to use just FEC.

Abstract High quality powering systems have become the requirements for computers and electronic devices users. Uninterruptible power systems (UPS) are needed in office automation, home and small and medium enterprise computers and governmental network projects. In 2006, total UPSs sold in PRC exceeded 1,279 thousand units, with a sales value exceeding 2.61 billion RMB. The UPS industry experienced an 8% stable growth backed by economy growth of PRC. This research served theoretical basis and the understanding of industry practices as the base, describing the business model of UPS industry in PRC. This thesis also contains an in-depth interview with the leader of Powercom Co., an UPS manufacturer in PRC, on topics such as channel structure (length, width and density), relation control, channel motivation (strategy in effect and methods used) and conflict management (reasons, forms and solutions), trying to combine theories and practices. This study found that Powercom experienced three channel transformations in PRC market. Phase 1: instead of touching the market directly, they entered PRC via an agent, plays only the role of manufacturer ¡V a longer, narrower channel structure, with a traditional marketing relation aims at short-term profits, and price is the incentive. When the relation went down, Powercom took destructive solutions. Phase 2: Retailing channels were established in provinces in PRC, and the PRC market was divided in to four independent geographic marketing sectors, no intersection selling were allowed ¡V allowing the four sections to have their own storage and selling systems and compete with each other, resulting horizontal conflicts between section sellers. Phase 3: the marketing efforts are directed by a Great China concept, although the four offices still in charge of dealing orders and selling, no geographical restrictions exist. The channel structure was turned from density to selective distribution. Their relation with distributors are thus turned in to vertical systems, thus common objective, instead of price alone is the incentive to motivate firm members. Keywords: Uninterruptible power systems, cannel transformation