Micro-channels are very important in bio-medical and cooler research. Although many research have been conducted with micro-channels, few results have been contributed to discuss the properties of fluids inside a micro-channel. For example, the thermal distribution of the fluid in a micro-channel is only simulated with numerical analysis approach. In our research, we aim to design a device that can measure real thermal data within a micro-channel. We first applied excimer laser lithography on a PMMA substrate to fabricate a micro-channel with 20 mm length, 200£gm width and 200£gm depth. Micro-heater and micro-thermal sensor is than fabricated by sputtering pt thin-thim with PVD process on a glass substrate. Finally, these devices were assembled with UV-curing and than applied for further testing. According to our experiment, lift-off process cannot be easily applied to fabricate micro-heater and micro-thermal sensor since the architecture of these devices were fragile in metal line sidewalls. Wet-lithography is than used to conquer this problem. Our primary test on this micro-thermal sensor shows that its resistance varies with thermal changes. Such mechanism can be applied to measuring thermal field in a micro-channel.

Digital signature is widely used to implement many secure protocols. A digital signature has three parameters. They are the message, the key pair, and the signature. In general, the message is given. The key pair is chosen randomly by the signer. The signature is computed from the message and the key pair. But in some cases, we can choose the value of one of the parameters, this may make it possible to other applications such as blind signatures or subliminal channels. There are some researches to discuss the relations between the parameters and the applications of the digital signatures. In this research, we will propose three new schemes as examples of this technique. The first one is a fair blind signature scheme. The other two are subliminal channel schemes. These three new schemes have some important properties. The concept of this research may help the future researches to find new applications of the digital signature. Meanwhile, these new schemes can show that how the concept can help us to develop or improve applications.

In this thesis, we propose a modified MT-CDMA system, which can improve channel estimation accuracy by using transmit diversity of pilot signals. We not only expound the principles and structures of the system we proposed, but analyze its performance in slow Rayleigh fading channel environment. According to different ways to assign data symbols of transmitted signals, we have two different bit error rate results. At the same transmit power, the simulation results show that when we combine comb-type pilot signals of two parallel channels to estimate channel gains, we can recover the drawbacks of comb-type pilot arrangement, which can not perform well in frequency selective fading channel. Finally, the numerical results will be also shown.

ABSTRACT One of the most important issues in Knowledge Management is ¡§knowledge transfer¡¨ and ¡§knowledge share¡¨. The knowledge transfer in organization needs some carriers and medias, and that is one of the factors to influence knowledge management performance. Base on the issue, this reaserch wil study the importance of media richness perception and it¡¦s influence factor from system effective perspective. This study develops based on the channel expansion theory (Carlson and Zmud,1994) and social influence (Fulk et al., 1990) . Four experiences of constructs in channel expansion theory were theexperience with the channel, experience with the messaging topic, experience with the organizational context, and experience with communication coparicipants. And, we will survey the e-learning environment in the NSYSU as our study sample. An empirical survey methodology is applied to test the research model and hypotheses proposed in this study. Five out of seven hypotheses are validated in our research model with Path Analysis. The research result reveals that the social influence dimension has the most impact on the perception of channel; on the other hand, experience with the channel and communication partner also result validates. Keywords: knowledge management, channel expansion theory, information systems effectiveness

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A complex array for constructing perfect sequences is presented in this paper. The row sequences and their discrete Fourier transform form two sets of perfect sequences. The column sequences are orthogonal to each other for any cyclic shift. In addition, any combination of the column sequences with complex weighting coefficients of equal amplitude is also a perfect sequence. In addition, a superimposed training scheme is also proposed for channel estimation in OFDM systems. The perfect sequence is adopted since it has a constant magnitude in both the time domain and the frequency domain. Although the derived channel estimator has a slightly worse performance since the unknown data contributes extra noise, the effective data throughput is substantially increased. In addition, the proposed scheme is shown to have a much better peak-to-average power ratio (PAPR) because the added perfect sequence has a constant magnitude in the time domain.

The Cable Television Channel Planning and Management Regulations, which was promulgated on December 13 in 2004, indicate clearly that each cable station¡¦s third channel is ¡§the public channel¡¨ to practice community people¡¦s ¡§media access rights¡¨. Its major purposes are to protect the freedom of speech, to ensure citizens having channels to express their opinions, and to facilitate the diverse social developments. Theoretically, public access channel should be viewed as the public sphere. Practically, due to the characteristics of local cable television, it is expected to preserve local culture, to educate the local people the functions of regional media, and to contribute to community development. Especially in today Taiwan¡¦s media environment, most media are controlled by the political and business forces and vested interest organizations, the local voice could not be heard in the mainstream media. This survey chose the public accessible channel 3 of the local cable stations in Tainan County (thereinafter referred as Tainan County Third Public Television Service) as study objects. There were three purposes of this study¡Xfirst of all, to understand the current situation of public access channels operated by local cable television stations and how public access channels apply to public affairs; second, to propose the appropriate operational modes for cable television stations by evaluating the difficulties and problems of practicing public affairs; and third, to discuss how public policy could be extend and constructed to create community interaction and hence a citizen society by exploring the interaction between local government and media and analyzing the best operational mode of public access channel. The results of this study indicated that due to the mutual interest structure of politics and businesses, the local government does not fulfill the role of administrator. The responsibility of media to promote civic society was abandoned or fulfilled just merely nominal by the local cable television owners. The channel for public participation is turned back to the communities. Based on the findings of this study, there are two suggestions for policy revision: first, amending the Cable Radio and Television Law and enacting the clauses of rewards and punishments for channel management to ensure the participation of public affairs; second, the public access channels of cable television stations should serve as a platform for video production for the public. This study mainly explored the possibility of using the public access channels of cable television to practice public affairs. Due to the scopes and limits of research design, the case examined was limited to the case of Tainan County. Advance studies could be focused on the performance of the provision of programs (i.e. programs in social community education, etc.) to contribute to the public sphere and civic society.

Multi-channel MAC protocol is that schedules frames to be exchanged on different channels. To analyze the performance of multi-channel MAC protocol, an analytical model is proposed to compute the network throughput. Simulation results show that the proposed model is able to model the behaviors of multi-channel MAC protocol accurately. Furthermore, based on the analysis model, in this thesis we also proposes an adaptive contention window scheme to enhance the network throughput by tuning the initial contention window size. Results indicate that the proposed scheme can reduce the cost of collisions and increase the network throughput.

This thesis addresses the design and implementation of a dual-mode channel decoder for two advanced wireless communication systems. One of the targetsystems is the digital video broadcasting for hand-held terminals (DVB-H) , and the other one is Worldwide Interoperability for Microwave Access (WiMAX) system based on the recently approved IEEE 802.16e. Both standards promise to deliver high data bandwidth within very broad regions. The error control coding schemes of both standards are all built on the similar concatenated code, with the exception of the way of data interleaving. Therefore, the decoders for both standards can be highly integrated. To achieve the low-cost and low-power decoder, this thesis proposes several novel design ideas. First, a fast dynamic multiple path convergence mechanism is proposed for the design of Viterbi decoder module, which can determine the survivor path at earlier stage. Furthermore, a new modified forward path prediction method is also presented which can efficiently predict the possiblesurvivor path such that the number of memory operations during the trace-back canbe significantly reduced. The proposed methodology can reduce up to 50% to 80%of memory operations compared with the best prediction scheme in the literature at high signal-to-noise ration. Secondly, for the block deinterleaver adopted by IEEE 802.16. a new multi-bank architecture is proposed by properly splitting and allocating the input data to suitable bank. The proposed block deinterleaver can be highly integrated with the byte-level convolutional deinterleaver adopted by the DVB-H standard by realizing the multiply First-In-First-Out (FIFO) data branches as the circular buffer. The other salient feature of the proposed dual-mode decoder is that all the major data storage units can all be realized by single-port memory such that the overall cost can be highly reduced.

In this thesis, the poly-Si TFTs with different channel width and channel length are successfully fabricated and characterized. In particular, by using the T-gate structure and body contact, we can measure the substrate current and body voltage. Therefore, short channel effects in polycrystalline silicon thin-film transistors are investigated clearly. In order to study impact ionization effect and floating body effect more carefully, we measure and compare the electrical behaviors of device with different grain boundary trap density, grain size, and channel dimension. The influences of these factors on the short channel effects are also discussed and explained. In this experiment, it is found that the devices with short channel length, exhibit improved normalized turn on current and smaller threshold voltage. But on the other hand the sever kink effect which generated by the impact ionization also observed. Moreover, the floating body under the channel region serve as a parasitic BJT as in silicon-on-insulator devices. The related single transistor latch-up is observed and discussed for short-channel devices with various channel width. The severe impact ionization effects in polycrystalline silicon thin-film transistors are investigated and characterized. By directly measuring the substrate current from conventional TFTs with body contact, the impact-ionization effects can be characterized and analyzed very clearly. An anomalous substrate current under high gate voltage is observed. The parasitic tunneling effect between inversion region and body region is proposed to explain this phenomenon. Finally, a physically-based model is established and compared with the measured substrate current. Good agreements are found when the vertical field scattering effect is included into the maximum electric field impact ionization model.