Au cours des dernières années, un développement continu a été observé dans les domaines des systèmes électroniques et des ordinateurs. Une série de mécanismes menaçant la fiabilité ont émergé. Par exemple, des défauts physiques provenant de fils mal lithographié, vias et d'autres dispositifs de bas niveau sont fréquemment observées dans les circuits nanométriques. D'autre part, les circuits sont également devenus plus sensibles aux grèves de particules excitées. Ces deux mécanismes, bien que essentiellement différente, peuvent causer de multiples fautes qui contribuent pour fiabilités plus faibles dans les circuits intégrés. Fautes multiples sont plus inquiétant que de simples car elles sont plus graves et aussi parce qu'ils peuvent surmonter les techniques de tolérance aux fautes. Les circuits numériques sont utilisés dans la plupart des systèmes électroniques aujourd'hui, mais il y a un contexte spécifique dans lequel ils doivent être fiable. Tel contexte comprend des applications de haute dépendabilité. Et cela est le scénario dans lequel cette thèse est conçu. Il a un double objectif: (a) de proposer des méthodes pour évaluer la fiabilité des circuits numériques, et (b) de proposer des techniques d'amélioration de la fiabilité. En ce qui concerne le premier objectif, plusieurs méthodes ont été proposées dans la littérature et le texte montre comment ces méthodes présentent des limitations en ce qui concerne la taille de circuit (nombre de portes), le type de circuit (séquentielle ou combinatoire) et le profil de faute (unique ou fautes multiples). Cette thèse propose deux méthodes pour l'évaluation de la fiabilité. La première méthode est appelée SPR+ et elle vise l'analyse de la logique combinatoire seulement. SPR+ améliore la précision de l'analyse, en tenant compte de l'effet de chaque nœud de fanout par rapport à la fiabilité de l'ensemble du circuit. Une autre méthode, appelée SNaP, est également proposé dans cette thèse. Il s'agit d'une approche hybride, car il est partiellement basée sur la simulation. SNaP peut être utilisé pour la logique combinatoire et séquentielle, et peut également être émulé dans un dispositif FPGA pour une analyse plus rapide. Les deux méthodes, SPR+ et SNAP, peuvent traiter de fautes multiples. / With the current advances achieved in the manufacturing process of integrated circuits, a series of reliability-threatening mechanisms have emerged or have become more prominent. For instance, physical defects originating from poorly lithographed wires, vias and other low-level devices are commonly seen in nanometric circuits. On the other hand, circuits have also become more sensitive to the strikes of highly energized particles. Both mechanisms, although essentially different, can cause multiple faults that contribute for lower reliabilities in integrated circuits. Multiple faults are more troubling than single faults since these are more severe and also because they can overcome fault tolerance techniques. Digital circuits are used in most electronic systems nowadays, but there is a specific context in which they are required to be reliable. Such context comprises high-dependability applications. This is the scenario in which this thesis is conceived. It’s goals are twofold : (a) to pro pose methods to assess the reliability of digital circuits, and (b) to propose techniques for reliability improvement. Concerning the first goal, several methods have been proposed in the literature and the text shows how these methods present limitations with respect to circuit size (number of gates), circuit type (sequential or combinational) and fault profile (single versus multiple faults). This thesis proposes two methods for reliability assessment. The first method is termed SPR+ and its targeted at the analysis of combinational logic only. SPR+ improves the average analysis accuracy by taking into account the effect of each fanout reconvergent node to the overall circuit reliability. Another method, termed SNaP, is also proposed in this thesis. It is a hybrid approach since it is partially based on simulation. SNaP can be used for combinational and sequential logic and can also be emulated in an FPGA device for faster analysis. Both SPR+ and SNaP can cope with multiple faults.

Abstract Heavy metals are used in many industrial processes and their cations are either valuable or environmentally harmful to discharge in wastewater. Thus, it is necessary to separate heavy metals in wastewater treatment. Amongst several technical methods of separation, use of permeable membranes is an important one. For separation processes, membranes can be selective towards a target heavy metal cation either against mono-valent common cations or against other similar heavy metal cations. Synthesis of selective permeable membranes for separation purposes is an area of continuous research to meet specific needs in different applications. One of the common applications of selective separation by a permeable membrane is cation/anion separation processes using cation exchange and anion exchange membranes. Another application of selective permeable membranes is the separation of mono-valent cations from other higher valence cations. Some researchers have focused on specific selective separation of heavy metal cation from other heavy metal cations having the same valent charge. Some use chelating particulates dispersed in a neutral polymeric membrane matrix and others applied a thin chelating film on the surface of a commercial cation exchange membrane. In this work, the synthesis of novel permeable selective membranes and their use for selective separation between two di-valent heavy metal cations is presented. Three different sets of membranes were prepared in non-imprinted and imprinted forms. The ion imprinted membranes form is prepared by pre-reacting the target metal ion with the selective chelating monomer before applying in situ polymerization step, and in the non-imprinted membranes form this step is not considered. Their morphological and chemical structures were determined and their separation performances were investigated using a diffusion dialysis technique. The first membrane (non-imprinted polyvinylidene fluoride-divinylbenzyl-triethylenetetramine (PVDF/diVB-TETA) and Cu-imprinted PVDF/diVB-TETA-Cu forms) was prepared by in situ polymerization of the chelating monomer divinylbenzyl-triethylenetetramine diVB-TETA (or diVB-TETA-Cu) within a PVDF substrate, using a divinylbenzene cross-linker. Fourier transform infrared FT-IR spectroscopy showed the successful in situ polymerization of the chelating monomer within the PVDF texture. The permeation study showed that the ion-imprinted membrane has a Cu2+ selectivity factor of 3.78, while the non-imprinted membrane has a Cu2+ selectivity factor of 1.65. In addition the Cu2+ permeation flux in the imprinted membrane is 3.9 time that in the non-imprinted membrane For the second membrane, the synthesis is similar to the first membrane for both non-imprinted and imprinted forms (polyvinylidene fluoride-divinylbenzyl-triethylenetetramine-N,N'-methylenebis(acrylamide) (PVDF/diVB-TETA-N) and PVDF/diVB-TETA-N-Cu respectively), except that the used cross-linker was N,N'-methylenebis(acrylamide). In addition, sodium 4-vinylbenzyl sulfonate was added in selected percentages, (5-15% mol), to enhance the permeation flux. FT-IR spectroscopy analysis of the prepared membranes confirmed the chemical structure of diVB-TETA-N and sulfonate group into PVDF. Permeation and selective separation studies for the prepared membranes showed that the ion-imprinted membrane has a higher selectivity for copper permeation over the non-imprinted membrane. However imprinted membrane showed a lower flux for the permeated cations than that of the non-imprinted membranes The addition of the sulfonate groups to the prepared membranes enhanced the flux of the permeated cations, but the copper selective permeation decreased for both types (non-imprinted and ion-imprinted). Moreover, the ion-imprinted membrane PVDF/diVB-TETA-N-Cu showed a lower flux for the permeated cations than that of the non-imprinted membranes PVDF/diVB-TETA-N. Selective separation factors decreased to unity when the content of the sulfonate groups increased to 15% mol. Ion imprinted membrane prepared with 10% of sulfonate group showed optimum copper selectivity factor (α = 30304) and permeation flux for copper (0.4949 μmol cm‒2 h‒1) The third membrane (non-imprinted Selemion TM cation exchange membrane-divinylbenzyl-triethylenetetramine (CMV-S/diVB-TETA) and ion-imprinted CMV-S/diVb-TETA-Cu forms) was prepared by in situ polymerization of the chelating monomer, diVB-TETA (or diVB-TETA-Cu), on the surface of the commercial cation exchange membrane, Selemion, using divinylbenzene as cross-linker. FT-IR spectroscopy confirmed the chemical structure of the chelating polymer on the CMV-S membrane surface. Permeation study showed that ion-imprinted CMV-S/diVB-TETA-Cu membrane reached high separation factor (α = 17), yet the flux is low (0.0391 μmol cm‒2 h‒1). Non-imprinted CMV-S/diVB-TETA membrane of thickness (0.115±0.005 mm) using cross-linker (10% DVB) showed reasonable copper selectivity factor (α = 2.723) and permeation flux (0.433 μmol cm‒2 h‒1) / Thesis / Doctor of Philosophy (PhD)

Our study investigated the effect of preparatory selective attention on encoding two target items (T1 and T2), causing an attentional blink effect (AB), as observed in previous studies. We altered participants' readiness state on a trial-to-trial basis using informative or uninformative cues for selective attention. Additionally, we varied their overall state of readiness by randomly mixing cue types (mixed cue-context) or presenting them in separate blocks (blocked cue- context). Our findings demonstrated a clear advantage in performance when participants received informative cues compared to uninformative ones in the mixed cue-condition, regardless of the lag between T1 and T2. Notably, in the blocked cue-context condition, cueing benefits were limited to the shortest T1-T2 lag. This suggests that participants proactively prepared to focus on T1 when anticipating conflict, but the extent of this preparation varied between cue-contexts. A heightened state of preparation led to an overinvestment of resources to T1 encoding, which negatively affected T2 encoding. / Thesis / Master of Science (MSc)

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Ultra-wideband systems can be used in indoor wireless personal area network (WPAN) or short-range wireless local area network (WLAN) transmission. Yet owing to the effects of indoor dense multipath, it will cause more power consumption. We usually use Rake receiver to improve system performance. However, we should do some compromise between system performance and the design complexity. Thus, the concept of Selective Rake can be used to substitute for the conventional Rake receiver. Selective Rake receiver uses fewer but more powerful paths instead of using all the paths to raise system performance. Hence, we have to precisely detect the multipath components for best performance. Earlier we use CLEAN algorithm to estimate the multipath components. The CLEAN algorithm can be used in selecting the paths with relatively high energy. But as the impact of frequency selective fading makes the transmitted signal distorted, the CLEAN algorithm no longer applies to this situation. Thus, we use Multiscale CLEAN algorithm instead. Multiscale CLEAN algorithm calculate the value of cross-correlation between the received signal and a set of waveforms, and then choose the higher one as the waveform transmitted. Besides, we use Maximal Ratio Combining to weigh the different paths to get the signal with more power. We represent the signal affected by frequency selective fading by using the second derivatives of Gaussian waveform function with different effective widths of pulse. The waveforms corresponding different effective widths have different spectra which represent the different effects of fading. It is seen that that the multiscale CLEAN has better performance than the CLEAN algorithm with more precise estimation of multipath components. In simulation result, we can figure out path searching using Multiscale CLEAN algorithm is more accurate than using CLEAN algorithm. Even the path with smaller energy gain, using multiscale CLEAN algorithm can search successfully, while CLEAN algorithm cannot do.

The problem of this study was to provide a more comprehensive and accurate profile of various aspects of selective mutism—family atmosphere/dynamics, aetiology and manifestations of mutism, usages and outcomes of therapeutic approaches, and a profile of the affected child—and to provide a more comprehensive and consistent basis to guide effective treatment strategies and facilitate additional research. A content analysis of case studies of selective mute children completed from 1929-1994 was used to educe this data.

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