Prediction of the rapidly fading envelope of a mobile radio channel enables a number of capacity improving techniques like fast resource allocation and fast link adaptation. This thesis deals with linear prediction of the complex impulse response of a channel and unbiased quadratic prediction of the power. The design and performance of these predictors depend heavily on the correlation properties of the channel. Models for a channelwhere the multipath is caused by clusters of scatterers are studied. The correlation for the contribution from a cluster can be approximated as a damped complex sinusoid. A suitable model for the dynamics of the channel is an ARMA-process. This motivates the use of linear predictors. A limiting factor in the prediction are the estimation errors on the observed channels. This estimation error, caused by measurement noise and time variation, is analyzed for a block based least squares algorithm which operates on a Jakes channel model. Efficient noise reduction on the estimated channel impulse responses can be obtained with Wienersmoothers that are based on simple models for the dynamics of the channel combined with estimates of the variance of the estimation error. Power prediction that is based on the squared magnitude of linear prediction of the taps will be biased. Hence, a bias compensated power predictor is proposed and the optimal prediction coefficients are derived for the Rayleigh fading channel. The corresponding probability density functions for the predicted power are also derived. A performance evaluation of the prediction algorithm is carried out on measured broadband mobile radio channels. The performance is highly dependent on the variance of the estimation error and the dynamics of the individual taps.

In the nervous system, the roles of Kv channels are well established as being critical for regulating action potential frequency, membrane potential, and neurotransmitter release. However, their role in glial cells, a non-excitable cell type, is yet to be fully understood. Whole-cell current kinetics, pharmacology, immunocytochemistry and RT-PCR were used to characterize A-type current in hippocampal astrocyte cultures to better understand its function. Pharmacological analysis suggests that ~70%, 10% and less than 5% of total A current is associated with Kv4, Kv3 and Kv1 channels, respectively. In addition, pharmacology and kinetics provide novel evidence for a significant contribution of KChIP accessory proteins to astrocytic A-channel composition. Localization of the Shaw Kv3.4 channel to astrocytic processes and the Shal Kv4.3 channel to soma suggest that these channels serve a specific function. Since astrocytes are known to be subjected to neuronal firing frequencies of up to 200 Hz in the hippocampus, the role of A currents in membrane voltage oscillations was assessed. Although TEA-sensitive delayed-rectifying currents are involved in the extent of repolarization, 4-AP-sensitive A currents serve to increase the rate. Astrocytes and HEK293 cells were used to investigate the mechanism of the previously found GABAA induced anion-mediated reduction of Kv channels in more detail. Astrocytes demonstrate an anion concentration specific depolarizing effect on inactivating A-type (also termed transient voltage-gated) K+ channel activation kinetics whereas a hyperpolarizing effect was seen upon expression of Kv4.2 or Kv1.4 in HEK293 cells, but only after disruption of the cytoskeleton using cytochalasin D. It is hypothesized that cytoskeletal interactions and Cl -mediated effects are mediated through N-terminal conformational stabilities. <p>In summary, the results indicate that hippocampal astrocytes in vitro express multiple A type Kv channel á subunits with accessory, Ca2+-sensitive cytoplasmic subunits that appear to be specifically localized to subcellular membrane compartments. Functions of these channels remain to be determined in a physiological setting, but suggest that A-type Kv channels enable astrocytes to respond rapidly with membrane voltage oscillations to high frequency incoming signals, possibly synchronizing astrocyte function to neuronal activity. Furthermore, studies of anion and cytoskeletal effects on Kv channels demonstrate channel function to be highly localized/targeted and susceptible to changes in ionic environment.

Sec translocon is the major machinery for protein translocation in E.coli including SecYEG, SecA and other Sec proteins. It is generally assumed that during translocation process, SecYEG serves as a protein-conducting channel and transports the protein across membranes by using SecA ATPase as driving force. However, previous work suggested that protein translocation can occur without SecYEG. In order to understand the role of SecA in this SecYEG-independent process, we use voltage clamp recording as a tool to study the ionic activity of SecA-dependent protein-conducting channel. In a major deviation from the conventional view, we found that SecA alone is sufficient to promote the channel activity with liposomes made of E.coli phospholipids in both whole cell recording in the oocytes and in the single channel recording with patch clamp. The activity is strictly dependent on the presence of functional SecA, including those from different species of bacteria. However, this SecA-alone dependent channel activity is less efficient compared to the membranes containing SecYEG. Furthermore, the channel activity loses the signal peptide specificity. Addition of purified SecYEG restores the signal peptide specificity as well as the efficiency. This channel activity is more sensitive to SecA-specific inhibitors compared with membranes containing wild-type SecYEG but is less sensitive to membranes containing suppressor proteins. This is the first time it has been shown that SecA binds to lipid low-affinity site and functions as a protein-conducting channel. To further characterize the structural roles of SecA as the core of the channel, we use several SecA variants to reconstitute with liposomes to determine the domains involved in forming functional channels. Using deletion truncated domains of 901 residues SecA and liposomes in the oocytes recordings, we identify two critical SecA domains for the formation of pore channel activity: with phospholipids alone, and for interacting with SecYEG to gain higher activity. These data provide fundamental understanding for the SecA-dependent protein –conducting channels. Our findings also suggest the possible evolution process on the protein translocation pathways from prokaryotes through eukaryotes.

In the nervous system, the roles of Kv channels are well established as being critical for regulating action potential frequency, membrane potential, and neurotransmitter release. However, their role in glial cells, a non-excitable cell type, is yet to be fully understood. Whole-cell current kinetics, pharmacology, immunocytochemistry and RT-PCR were used to characterize A-type current in hippocampal astrocyte cultures to better understand its function. Pharmacological analysis suggests that ~70%, 10% and less than 5% of total A current is associated with Kv4, Kv3 and Kv1 channels, respectively. In addition, pharmacology and kinetics provide novel evidence for a significant contribution of KChIP accessory proteins to astrocytic A-channel composition. Localization of the Shaw Kv3.4 channel to astrocytic processes and the Shal Kv4.3 channel to soma suggest that these channels serve a specific function. Since astrocytes are known to be subjected to neuronal firing frequencies of up to 200 Hz in the hippocampus, the role of A currents in membrane voltage oscillations was assessed. Although TEA-sensitive delayed-rectifying currents are involved in the extent of repolarization, 4-AP-sensitive A currents serve to increase the rate. Astrocytes and HEK293 cells were used to investigate the mechanism of the previously found GABAA induced anion-mediated reduction of Kv channels in more detail. Astrocytes demonstrate an anion concentration specific depolarizing effect on inactivating A-type (also termed transient voltage-gated) K+ channel activation kinetics whereas a hyperpolarizing effect was seen upon expression of Kv4.2 or Kv1.4 in HEK293 cells, but only after disruption of the cytoskeleton using cytochalasin D. It is hypothesized that cytoskeletal interactions and Cl -mediated effects are mediated through N-terminal conformational stabilities. <p>In summary, the results indicate that hippocampal astrocytes in vitro express multiple A type Kv channel á subunits with accessory, Ca2+-sensitive cytoplasmic subunits that appear to be specifically localized to subcellular membrane compartments. Functions of these channels remain to be determined in a physiological setting, but suggest that A-type Kv channels enable astrocytes to respond rapidly with membrane voltage oscillations to high frequency incoming signals, possibly synchronizing astrocyte function to neuronal activity. Furthermore, studies of anion and cytoskeletal effects on Kv channels demonstrate channel function to be highly localized/targeted and susceptible to changes in ionic environment.

In a CR network, the maximum SUs throughput is desired generally. In this thesis, We investigate and formulate the problem of the secondary users¡¦ throughput maximization in cognitive radio systems under channel capacity constrain. By using KKT theorem, an objec- tive function is developed to obtain an optimal solution for the SU throughput maximization problem. An numerical example is also presented for illustration. The most important results revealed in the example show that the maximum SU throughput is achieved by cooperating an optimal number of SU pairs instead of cooperating all the SU pairs.

Due to the gradual increase of the women income and with the rise of living standard, the market also expands for cosmetic products; the cosmetics enter the pluralistic channels district trough the market. How to select the best channel and maintain the service quality in distribution channels of cosmetics are important for the vendor. Thus, this research aims to discuss the relation between the distribution channel of cosmetics, consumer behavior and service quality. This research takes the SHISEIDO¡¦s consumers from Kaohsiung as the research objects for verification and analysis, the questionnaire materials which carry on 200 consumers. The major result of this research as follow: consumers of different behavior have obvious differences in select channels, and different channels have obvious differences in service quality.

Following to the industrial competition which is getting along intense day by day, it is a deeply concerned subject to the manufacturer from spread global world, how to prove their product into the international market successfully. Facing in the culture and language of different country, as well as various countries¡¦ tedious product laws, regulations and multiple limits in the procedure, the manufacturer confront the enormous challenge with the product development into the global market. Increasing by the demands of the global certification system gradually, in order to win the initiative, it is essential to let their product obtain various countries¡¦ approval positively and rapidly. The main purpose for this research contains the discussion in different circuit¡¦s characteristic of certification body, different circuit¡¦s shortcomings and advantages, and the choices¡¦ estimation of consideration factor in certification systems. This pattern of research adopts personal methodology in processing empirical analysis which belongs to the personal design and analysis issue. We discover that different circuit strategy causes the influence on the manufacturer and certification body. While the certification body draws up the circuit strategy to comply with the manufacturer¡¦s demands, they must expect the effect to different circuit¡¦s variation meanwhile. Speaking of the manufacturer or certification body, it causes different kinds of advantages and shortcomings no matter for the zeroth order circuit or the first-order circuit. Although the zeroth order circuit is a pipeline that lets the coordination and communication between manufacturer and the certification body directly, however, the latent shortcoming still exists. The different circuit system applies to different suitable situation in Taiwan. Keywords: Distribution Channel Strategies, Certification Body

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.

In previous studies, the thermal performance of ribbed channels was studied for Reynolds numbers up to 100,000 with different rib shapes. In more recent studies, the thermal performance of ribbed channels was studied up to Reynolds numbers of 400,000 for angled ribs to cover the range of internal cooling inside land-based gas turbines. Previous studies also show that the thermal performance of V-shaped ribs is better than the angled ribs. In this study, the Reynolds number from 30,000 to 400,000 is studied with V-shaped ribs. The blockage ratio e/D is 0.1, 0.15, and 0.18 and spacing ratio P/e is 5, 7.5, and 10. The results show that the Nusselt number enhancement decreases when the Reynolds number increases. The friction factor is found to be independent of The Reynolds number. The thermal performance decreases when the Reynolds number increases. Correlations for the Nusselt number and the friction factor as function of Re, e/D, and P/e are developed.

This work presents a data estimation scheme for wide band multi-channel charge sampling receivers with sinc filter banks together with a complete system calibration and synchronization algorithm for the receiver. A unified model has been defined for the receiver containing all first order mismatches, offsets and imperfections and a technique based on least mean squares algorithm is employed to track these errors. The performance of this technique under noisy channel conditions has been verified. The sinc filter bank is compared with the conventional analog filter banks and it is shown that the sinc filter banks have very low computational complexity in data estimation Nextly, analytical tools for the design of clock-jitter tolerant multi-channel filterbank receivers have been developed. Clock-jitter is one of the most fundamental obstacles for the future generation of wideband receivers. Additionally all the trade-offs and specifications of a design example for a multi-channel receiver that can process a 5 GHz baseband signal with 40 dB of signal-to-noise-ratio (SNR) using sampling clocks that can tolerate up to 5 ps of clock-jitter standard deviation are presented. A novel bandwidth optimization technique has been presented. As a part of it the bandwidth of the filters present in each path is optimized thereby improving the performance of the receiver further in the presence of sampling clock jitter. The amount of bandwidth reduction possible depends on the order of the filter and the noise amplification provided by the reconstruction matrix. It has been shown that 3rd order filters of bandwidth 1 GHz can be replaced with 1st order filters of bandwidth 100 MHz without any depreciation in the output resolution, implying huge power savings.