<p>In an optimal power control scheme for a Code Division Multiple Access (CDMA) system all mobile stations signals should arrive to the base station at equal power. If not, stronger singals may cause too much interference and block out weaker ones. Commonly used power control schemes utilizes the Signal to Interference Ratio (SIR) to design a Power Control Command (PCC) to adjust the transmit power of the mobile station. A significant problem within the conventional methods is the slow SIR recovery due to deep channel fades. Conventional methods base the PCC on the previous channel state when in fact, the channel state may have significantly changed when transmission occurs. These channel changes may cause the SIR to drop or rise drastically and lead to uncontrollable Multi Access Interference (MAI) resulting in power escalation and making the system unstable. In order to overcome power escalation and improve the recovery from deep fades a novel power control method has been developed. Based on Linear Quadratic Control and Kalman filtering for channel prediction this method designs the PCC based on the coming channel state instead of the current. This optimizes the PCC for the channel state where transmission occurs. Simulations show that this control scheme outperforms previous methods by making the impacts of the deep fades less severe on the SIR and also improves the overall SIR behaviour.</p>

<p><strong>Aim: </strong>The aim of this study is to investigate how retailer’s customer loyalty program can influence the channel power and what relationship between retailer with manufacturer can be created when channel power changes.</p><p> </p><p><strong>Method: </strong>A case study was adopted, and a qualitative research and face-to-face interview were used to collect the fundamental data.</p><p> </p><p><strong>Result & Conclusions</strong>: The results exhibit that the customer loyalty program implemented by retailer can increase its channel power (both in basic power and market power) and create a dominant relationship with high channel conflict with its manufacturer. Based on the research of the case company, I found a close relationship with cooperation and trust could be developed based on the customer loyalty program between retailer and manufacturer to create benefit for the both.</p><p><strong> </strong></p><p><strong>Suggestions for future research: </strong>Only adopted one case and one interview in the research is the main limitation. Additionally, the limited sample size limited the research in some generalizations. It is difficult to use only one case to represent the whole situation of the market. In the further, a larger sample size adopted in research can increases the reliability of researcher’s generalization.</p><p><strong> </strong></p><p><strong>Contribution of the thesis:</strong> The research discloses how retailer’s customer loyalty program can influence the channel power. The drawbacks of the dominant relationship which caused by channel power rising have been researched. How to develop close relationship and what benefit it can bring to retailer have also been investigated in the end.</p>

<p>Increasing capacity in wireless mesh networks can be achieved by using multiple channels and radios. By using different channels, two nodes can send packets at the same time without interfering with each other. To utilize diversity of available frequency, typically cards use channel-switching, which implies significant overhead in terms of delay. Assignment of which channels to use needs to be coupled with routing decisions as routing influences topology and traffic demands, which in turn impacts the channel assignment.</p><p>Routing algorithms for wireless mesh networks differ from routing algorithms that are used in wired networks. In wired networks, the number of hops is usually the only metric that matters. Wireless networks, on the other hand, must consider the quality of different links, as it is possible for a path with a larger amount of hops to be better than a path with fewer hops.</p><p>Typical routing protocols for wireless mesh networks such as Optimized Link State Routing (OLSR) use a single path to send packets from source to destination. This path is precomputed based on link state information received through control packets. The consideration of more information than hop-count in the routing process has shown to be beneficial as for example link quality and physical layer data rate determines the quality of the end-to-end path. In multi-channel mesh networks, also channel switching overhead and channel diversity need to be considered as a routing metric. However, a major drawback of current approaches is that a path is precomputed and used as long as the path is available and shows a good enough metric. As a result, short term variations on link quality or channel switching are not considered.</p><p>In this thesis, a new routing protocol is designed that provides a set of alternative forwarding candidates for each destination. To minimize delay (from both transmission and channel switching), a forwarding mechanism is developed to select one of the available forwarding candidates for each packet. The implementation was tested on an ARM based multi-radio platform, of which the results show that in a simple evaluation scenario the average delay was reduced by 22 % when compared to single path routing.</p>

Two problems of computer security are investigated. On one hand, we are facing a practical problematic of actual processors: the cache, an element of the architecture that brings flexibility and allows efficient utilization of the resources, is demonstrated to open security breaches from which secret information can be extracted. This issue required a delicate study to understand the problem and the role of the incriminated elements, to discover the potential of the attacks and find effective countermeasures. Because of the intricate behavior of a processor and limited resources of the cache, it is extremely hard to write constant-time software. This is particularly true with cryptographic applications that often rely on large precomputed data and pseudo-random accesses. The principle of time-driven attacks is to analyze the overall execution time of a cryptographic process and extract timing profiles. We show that in the case of AES those profiles are dependent on the memory lookups, i.e. the addition of the plaintext and the secret key. Correlations between some profiles with known inputs and some with partially unknown ones (known plaintext but unknown secret key) lead to the recovery of the secret key. We then detail access-driven attacks: another kind of cache-based side channel. This case relies on stronger assumptions regarding the attacker's capacities: he must be able to run another process, concurrent to the security process. Even if the security policies prevent the so-called "spy" process from accessing directly the data of the "crypto" process, the cache is shared between them and its behavior can lead the spy process to deduce the secrets of the crypto process. Several ways are explored for mitigations, depending on the security level to reach and on the attacker's capabilities. The respective performances of the mitigations are given. The scope is however oriented toward software mitigations as they can be directly applied to patch programs and reduce the cache leakage. On the other hand, we tackle a situation of computer science that also concerns many people and where important economical aspects are at stake: although spam is often considered as the other side of the Internet coin, we believe that it can be defeated and avoided. A increasing number of researches for example explores the ways cryptographic techniques can prevent spams from being spread. We concentrated on studying the behavior of the spammers to understand how e-mail addresses can be prevented from being gathered. The motivation for this work was to produce and make available quantitative results to efficiently prevent spam, as well as to provide a better understanding of the behavior of spammers. Even if orthogonal, both parts tackle practical problems and their results can be directly applied.

The motivation to study this non-classical CMOS device is necessary to face with the ITRS constraints. In the ITRS roadmap, the gate length of devices are being scaled down rapidly but this rapid scaling is not in pace with the relatively slow scaling of the gate equivalent oxide thickness which leads to a degradation in the performance of the transistor. One of the solutions to this problem is the use of non-classical devices, such as the Gate-All-Around (GAA) MOSFET. Owing to the flexibility of SOI technology, these novel devices can be adapted to this technology bringing along with it the benefit of SOI technology. One of the main advantage of building this GAA device on SOI technology is that it offers the possibility whereby the second gate is easily built into the back of the device. GAA devices are also interesting because they do not need to scale down the thickness of the gate oxide rapidly but still able to maintain a suitable thickness to avoid problems such as current leakage through the thin gate oxide by tunnelling. The objective of this research can be divided into three parts; the first is to study the feasibility of the various fabrication process for this GAA device, the second to analyse the electrical characteristics of these fabricated GAA devices from DC characteristics up to 110 GHz and the third one is the use of commercial numerical simulation softwares (IE3D, Silvaco) in order to describe the physics of these novel devices. In this study, these different structures shows advantages and disadvantages when used in either analog or RF applications. The graded-channel structure has shown that it is advantageous when used in high performance analog circuits. The advantages of this structure is further enhanced when it is combined with the double-gate structure, forming a double-gate graded channel SOI MOSFET. Optimizing in terms of doping level along the channel of the graded-channel is important to yield good electrical results. In order for these devices to be successful commercially, it is important that they are compatible with the fabrication technology and trends available today and in the near future. To confirm that these devices can be adapted into today's and tomorrow's technology, we have shown that these they are easily adaptable in the current technology. Multiple-gate devices are a new group of devices which have been identified by ITRS as potential devices to meet the demands in the future. In this study, we have shown that these multiple-gate devices do indeed show improved short-channel effects and improved analog and RF characteristics when compared to the single-gate devices in existence. One of the main contributors to these improvements is due to what is known as the “volume inversion”.

The purpose of this thesis is to study the shock/wave turbulent boundary layer interaction by using delayed-detached-eddy simulation (DDES) model with a low diffusion E-CUSP (LDE) scheme with fifth-order WENO scheme. The results show that DDES simulation provides improved results for the shock wave/turbulent boundary layer interaction compared to those of its predecessor the detached-eddy simulation (DES). The computation of mesh refinement indicates that the grid density has significant effects on the results of DES, while being resolved by applying DDES simulation. Spalart in 1997 developed the Detached-Eddy Simulation (DES) model, which is a hybrid RANS and LES method, to overcome the intensive CPU requirement from LES models. Near the solid surface within a wall boundary layer, the unsteady RANS model is realized. Away from the wall surface, the model automatically converts to LES. The Delayed-Detached-Eddy Simulation (DDES) was suggested by Spalart in 2006 to improve the DES model previously developed. The transition from the RANS model to LES in DES is not grid spacing independent, therefore a blending function is introduced to the recently developed DDES model to make the transition from RANS to LES grid spacing independent. The DDES is validated by computing a 3D subsonic flat plate turbulent boundary layer. The first case studied using DDES is a 3D transonic channel with shock/turbulent boundary layer interaction. It consists of two straight side walls, a straight top wall, and a varying shape in span-wise direction for a bottom wall. The second case studied consists of a 3D transonic inlet-diffuser. Both results are compared with experimental data. The computed results of the transonic channel agree well with experimental data.

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 121-137).

There is an increasing demand to support high data rate multimedia applications over the current day wireless networks which are highly prone to errors. Relay channels, by virtue of their spatial diversity, play a vital role in meeting this demand without much change to the current day systems. A compress-forward relaying scheme is one of the exciting prospects in this regard owing to its ability to always outperform direct transmission. With regards to video transmission, there is a serious need to ensure higher protection for the source bits that are more important and sensitive. The objective of this thesis is to develop a practical scheme for transmitting video data over a relay channel using a compress-forward relaying scheme and compare it to direct and multi-hop transmissions. We also develop a novel scheme whereby the relay channel can be used as a means to provide the required unequal error protection among the MPEG-2 bit stream. The area of compress-forward (CF) relaying has not been developed much to date, with most of the research directed towards the decode-forward scheme. The fact that compress-forward relaying always ensures better results than direct transmission is an added advantage. This has motivated us to employ CF relaying in our implementation. Video transmission and streaming applications are being increasingly sought after in the current generation wireless systems. The fact that video applications are bandwidth demanding and error prone, and the wireless systems are band-limited and unreliable, makes this a challenging task. CF relaying, by virtue of their path diversity, can be considered to be a new means for video transmission. To exploit the above advantages, we propose an implementation for video transmission over relay channels using a CF relaying scheme. Practical gains in peak signal-to-noise ratio (PSNR) have been observed for our implementation compared to the simple binary-input additive white Gaussian noise (BIAWGN) and two-hop transmission scenarios.

Les potentiels daction neuronaux sont suivis dune post-hyperpolarisation qui est médiée par les canaux K+ Ca2+-dépendant de faible conductance (canaux SK). Cette post-hyperpolarisation joue un rôle important dans la régulation de lexcitabilité neuronale et les agents modulant lamplitude cette post-hyperpolarisation possèdent un intérêt thérapeutique potentiel (schizophrénie, maladie de Parkinson, maladie dAlzheimer, épilepsie,). Dans un premier temps, cette étude pharmacochimique de la N-méthyl-laudanosine (NML) a permis de mettre en évidence un composé tertiaire possédant une affinité significative vis-à-vis des canaux SK. Cette observation a initié la recherche de bloqueurs non quaternaires des canaux SK. Dans cette seconde partie, deux groupes de composés ont été préparés et testés. Dune part, des bis-isoquinoliniums ont montré des affinités 50 x plus élevées que celle de la NML. Dautre part, la préparation et la résolution de bis-1,2,3,4-tétrahydroisoquinoléines a permis dobtenir un stéréoisomère 4 x plus affin que la NML. Ce composé tertiaire a été caractérisé sur le plan chimique et physico-chimique (cristallographie RX, lipophilie et pKas) et étudié dans un modèle comportemental chez le rat. Sur base des premiers résultats comportementaux, un effet central a effectivement été observé.

Relations between propagators and Green functions of Hamiltonians which are SUSY partners have been obtained. New exact propagators for the family of multi-well, time-dependent and non-hermitian potentials have been calculated. Non-conservative SUSY transformation has been studied in the case of multichannel Schrodinger equation with different thresholds. Spectrum (bound/virtual states and resonances) of the non-conservative SUSY partner of zero potential has been founded. Exactly solvable model of the magnetic induced Feshbach resonance has been constructed. This model was tested in the case of Rb$^{85}$. Conservative SUSY transformations of the first and the second order have been studied in the case of multichannel Schrodinger equation with equal thresholds. Transformations which introduce non-trivial coupling between scattering channels have been founded. The first order SUSY transformation which preserves $S$-matrix eigen-phase shifts and modifies mixing parameter has been founded in the case of two channel scattering with partial waves of different parities. In the case of coinciding parities we have found the second order SUSY transformation which preserves $S$-matrix eigen-phase shifts and modifies mixing parameter. Phenomenological two channel $^3S_1-^3D_1$ neutron-proton potential has been obtained by using single channel, phase equivalent and coupling SUSY transformations applied to zero potential.