Dissertations / Theses on the topic 'Kirk effect'

Ce travail est une contribution à l'étude du transistor bipolaire hyperfréquence sur puce de silicium. Il présente tout d’abord deux méthodes originales permettant de réduire la Capacité extrinsèque Base-Collecteur, d'augmenter la tension de claquage Base-Collecteur, d'augmenter la tension Early VA, d'augmenter le gain en puissance maximal Gpmax et d'augmenter la fréquence de transition FT. Il présente ensuite un nouveau transistor, de structure hybride entre le NPN vertical et le NPN latéral, baptisé bipolaire-CLEV (à Collecteur Latéral-Emetteur Vertical). Ce travail est généralisable à d'autres technologies de transistors hyperfréquences telles que les transistors à substrats III-V ou les transistors à hétérojonctions
This work is a contribution to the study of the high-speed bipolar transistor on silicon chip. First, it presents two original methods allowing to reduce the Base-Collector extrinsic Capacitance, to increase the Base-Collector breakdown voltage, to increase the Voltage Early VA, to increase the maximum power gain Gpmax and to increase the transition frequency FT. Then, it presents a new transistor, hybrid structure between the vertical NPN and the lateral NPN, named bipolar-CLEV (lateral collector-vertical emitter). This study can be generalized to other high speed transistor technologies such as III-V substrate transistors or heterojunction transistors

Ce travail est une contribution à l'étude du transistor bipolaire hyperfréquence sur puce de silicium. Il présente tout d’abord deux méthodes originales permettant de réduire la Capacité extrinsèque Base-Collecteur, d'augmenter la tension de claquage Base-Collecteur, d'augmenter la tension Early VA, d'augmenter le gain en puissance maximal Gpmax et d'augmenter la fréquence de transition FT. Il présente ensuite un nouveau transistor, de structure hybride entre le NPN vertical et le NPN latéral, baptisé bipolaire-CLEV (à Collecteur Latéral-Emetteur Vertical). Ce travail est généralisable à d'autres technologies de transistors hyperfréquences telles que les transistors à substrats III-V ou les transistors à hétérojonctions
This work is a contribution to the study of the high-speed bipolar transistor on silicon chip. First, it presents two original methods allowing to reduce the Base-Collector extrinsic Capacitance, to increase the Base-Collector breakdown voltage, to increase the Voltage Early VA, to increase the maximum power gain Gpmax and to increase the transition frequency FT. Then, it presents a new transistor, hybrid structure between the vertical NPN and the lateral NPN, named bipolar-CLEV (lateral collector-vertical emitter). This study can be generalized to other high speed transistor technologies such as III-V substrate transistors or heterojunction transistors

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.
Includes bibliographical references (leaves 68-72).
by Alexander N. Ernst.
M.Eng.

The purpose of this study was to assess the acute effects of static stretching on foot velocity at impact with a soccer ball. Eighteen Division I female soccer athletes underwent two test conditions separated by 48 hr. Each condition was randomly assigned and began by placing four retro-reflective markers on bony landmarks of the ankle (total of eight markers, four on each ankle). One condition was the no-stretch condition, in which each participant performed a self-paced jog for 5 min as a warm-up, and then sat quietly for 6 min before performing three maximal instep kicks into a net. The second condition was the stretch condition, which was identical to the no-stretch condition, except the participants performed a series of six randomly ordered stretches instead of sitting quietly for 6 min. Three-dimensional motion analysis was used to quantify the resultant velocity of the head of the 5th metatarsal immediately prior to foot impact with a soccer ball. The results of a dependent t test indicated that there was no significant difference between the no-stretch (18.34 ± 1.29 m/s) and stretch conditions (17.96 ± 1.55 m/s; p = .102, d = .3) Based on these findings, acute stretching performed one time for 30 s before maximal instep soccer kicking has no effect on the resultant foot velocity of Division 1A university female soccer players. Pre-event stretching performed in a like manner may best be prescribed at the discretion of the athlete.

Master of Science
Department of Electrical and Computer Engineering
William Kuhn
Studies of Silicon-on-Sapphire (SOS) CMOS device operation in cryogenic environments are presented. The main focus was to observe the characteristic changes in high, medium and low threshold SOS NFETs as well as SOS silicide blocked (SN) resistors when the operational temperature is in the devices’ freeze-out range below 77 Kelvin. The measurements taken will be useful to any integrated circuit (IC) designer creating devices based on an SOS process intended to operate in cryogenic environments such as superconducting electronics and planetary probes. First, a 1N4001 rectifier and a 2N7000 NFET were tested to see how freeze-out effects standard diode and MOS devices. These devices were tested to see if the measurement setup could induce carrier freeze-out. Next, SOS devices were studied. Data was collected at room temperature and as low as 5 Kelvin to observe resistance changes in an SN resistor and kink effect, threshold voltage shifts and current level changes in transistors. A 2μm high threshold NFET was tested at room temperature, 50 Kelvin, 30 Kelvin and 5 Kelvin to observe effects on I-V curves at different temperatures with-in the freeze-out range. A 2μm medium threshold NFET was tested down to 56 Kelvin to see if the behavior is similar to the high threshold FET. A 2μm intrinsic, or low threshold, NFET was also tested with the assumption it would be the most susceptible to carrier freeze-out. All of the devices were found to behave well with only mild effects noted.

Purpose: The aim of this study was to investigate the relationship between heart rate and external workload in intermittent sprint with and without instep kick. Participants: 20 male junior players participated in the field experiment consisting of different exercise with blocks of sprint. Method: The exercise was conducted on two different days and the order of the sprint with and without instep kick was changed each day. One sprint is 32 meters in total and last 5 to 6 seconds, with a 180 degrees turning point halfway. A new sprint was performed every 30 seconds. Recovery time between the 2 blocks of sprints was about 3 minutes. The exercise was used as a part of normal training regime which means that it was not added to the team’s weekly training dosage. Heart rate (HR) was recorded by the Polar Team 2 system and ZXY tracking device was used to record position and acceleration of the players from which work and power were calculated. Result: No significant effect was found for instep kick or players playing position in intermittent sprint. Significant differences were observed for average heart rate (HRavg) and peak heart rate (HRpeak), but not for duration of heart rate peak in seconds (TPHR) between the two days. Considering interaction between day and different blocks of sprint, significant differences was found for HRavg, HRpeak (p < 0.01), but not for duration of TPHR. For absolute work (AW), peak power acceleration (Ppeak-acc) and peak power deceleration (Ppeak-dec) statistical significant differences were not observed between days and blocks of sprint. No significant effect was found for interaction between condition and day for these variables. Conclusion: This study demonstrated that neither an instep kick nor playing position has an effect on sprint performance, meaning that adding instep kick into intermittent exercise does not affect performance regarding heart rate and external workload.

La magnétohydrodynamique présente un grand intérêt pour l'étude des plasmas de fusion magnétiquement confinés. Les équations linéarisées de la MHD idéale peuvent être mises sous une forme adaptée à l'analyse spectrale; le système est alors décrit par des opérateurs linéaires auto-adjoints. La prise en compte d'une résistivité finie affecte profondément le système. Les opérateurs linéaires ne sont plus auto-adjoints; de ce fait, on ne peut plus recourir à un principe variationnel. Les valeurs propres deviennent complexes et de nouvelles instabilités apparaissent. Nous présentons un code numérique qui résout les équations linéarisées de la MHD résistive en géométrie cylindrique; un choix judicieux des éléments finis (des polynômes cubiques d'Hermite et de polynômes quadratiques} s'avère nécessaire pour approximer correctement la totalité du spectre. Le problème aux valeurs propres généralisé est résolu par l'itération vectorielle inverse qui se montre la plus efficace. Nous discutons également un code d'évolution temporelle implicite fondé sur la même discrétisation. Les modes d'Alfvèn forment une composante continue du spectre. Dans le cas résistif ces modes singuliers disparaissent; les fonctions propres deviennent régulières et les valeurs propres se placent sur des courbes bien définies du plan complexe. Nous étudions également le spectre d'une couche de plasma dans laquelle la conductivité thermique est radiative. Nous montrons qu'en géométrie torique le kink interne est toujours instable pour des profils de courant creux et le taux de croissance est plus élevé que celui du kink interne pour un profil de courant monotone. Des simulations non linéaires de cette instabilité en géométrie cylindrique montrent qu'elle s'achève par une disruption ou une saturation, suivant l'énergie disponible.

Haematopoietic stem cell transplantation is the only curative treatment for some forms of haematologcial malignancies and bone marrow failure. The role of donor Natural Killer (NK) cells that accompany the donor stem cells is under investigation. In particular, there is interest in the role of the killer immunoglobulin-like receptors (KIR) family of receptors expressed on the surface receptors of NK cells. In this study, we focused on the donor KIR genes and the possibility that the KIR receptors interact with other transplant variables to influence survival. We analyzed a cohort of 140 unrelated donors from bone marrow transplants carried out at Royal Perth Hospital and Princess Margaret Hospital. The variables that were analyzed for interactions with KIR were: cytomegalovirus (CMV) status, transplant graft source, conditioning agents. A number of significant interactions between KIR and transplant variables were identified, the strongest being the interaction between KIR2DS2 and the use of cyclophosphamide as a conditioning agent. Kaplan-Meier analyses showed that the presence of KIR2DS2 in a cyclophosphamide positive transplant resulted in a significantly improved survival (p=0.002) whereas the presence of KIR2DS2 in a cyclophosphamide negative transplant resulted in a poorer survival (p=0.032). Hence the presence of KIR2DS2 could be beneficial or deleterious depending on the presence or absence of cyclophosphamide. As this was an exploratory study, observations of the interactions discovered need to be confirmed in additional studies.

Les cellules tueuses naturelles (NK) sont régulées par des récepteurs activateurs et inhibiteurs. La plupart des récepteurs inhibiteurs reconnaisse des molécules du complexe majeur d'histocompatibilité (CMH) de classe I, et protège les cellules saines des phénomènes d'auto-immunité médiés par les cellules NK. Cependant, certains récepteurs activateurs, incluant le récepteur killer cell Ig-like receptor (KIR) 2DS1, reconnaissent aussi des ligands CMH de classe I. Cela pose la question de savoir comment les cellules NK qui expriment des récepteurs activateurs deviennent tolérantes au soi. Nous avons cherché à déterminer si la présence de HLA-C2, le ligand du récepteurs 2DS1, peut induire les cellules NK qui expriment le 2DS1 à développer un état de tolérance au soi. Indépendamment de la présence ou de l'absence du ligand HLA-C2 dans le donneur, une activité anti-HLA-C2 a été identifiée in vitro dans certains clones NK 2DS1-positifs. La fréquence des clones NK avec réactivité anti-HLA-C2 était élevée parmi les donneurs homozygotes pour HLA-C1. De façon étonnante, nous n'avons pas constaté de différence statistiquement significative dans la fréquence de cytotoxicité anti-HLA-C2 entre les donneurs HLA-C2 hétérozygotes et les donneurs sans ligand HLA-C2. Par contre, les donneurs HLA-C2 homozygotes montrent une fréquence réduite de clones NK avec réactivité anti-HLA-C2 par rapport aux autres donneurs. Clones 2DS1-positifs qui co-expriment des KIR inhibiteurs spécifiques des molécules HLA de classe I du soi n’étaient pas communément cytotoxiques, et la cytotoxicité anti-HLA-C2 était limité presque exclusivement à des clones positifs seulement pour 2DS1 (« single positive » 2DS1 clones). Nous avons aussi identifié des clones 2DS1 « single positive » avec réactivité anti-HLA-C2 dans des patients recevant une greffe de cellules souches hématopoïétiques à partir de donneurs 2DS1. Ces résultats montrent que plusieurs cellules NK avec réactivité anti-HLA-C2 sont présentes dans des donneurs 2DS1 soit hétérozygotes soit homozygotes pour HLA-C1. En revanche, les clones 2DS1-positifs obtenus par des donneurs homozygotes pour HLA-C2 sont fréquemment tolérants aux antigènes HLA-C2
NK cells are regulated by inhibiting and activating cell surface receptors. Most inhibitory receptors recognize MHC-class I antigens, and protect healthy cells from NK cell-mediated auto-aggression. However, certain activating receptors, including the human killer cell Ig-like receptor (KIR) 2DS1, also recognize MHC-class I. This raises the question of how NK cells expressing such activating receptors are tolerized to host tissues. We investigated whether the presence of HLA-C2, the cognate ligand for 2DS1, induces tolerance in 2DS1-expressing NK cells. Anti-HLA-C2 activity could be detected in vitro in some 2DS1 positive NK clones irrespective of presence or absence of HLA-C2 ligand in the donor. The frequency of anti-HLA-C2 reactivity was high in donors homozygous for HLA-C1. Surprisingly, there was no significant difference in frequency of anti-HLA-C2 cytotoxicity in donors heterozygous for HLA-C2 and donors without HLA-C2 ligand. However, donors homozygous for HLA-C2 had significantly reduced frequency of anti-HLA-C2 reactive clones as compared to all other donors. 2DS1 positive clones that express inhibitory KIR for self-HLA class I were commonly non-cytotoxic, and anti-HLA-C2 cytotoxicity was nearly exclusively restricted to 2DS1 single positive clones lacking inhibitory KIR. 2DS1 single positive NK clones with anti-HLA-C2 reactivity were also present post-transplantation in HLA-C2 positive recipients of hematopoietic stem cell transplants from 2DS1 positive donors. These results demonstrate that many NK cells with anti-HLA-C2 reactivity are present in HLA-C1 homozygous and heterozygous donors with 2DS1. In contrast, 2DS1 positive clones from HLA-C2 homozygous donors are frequently tolerant to HLA-C2

As Si-manufacturing compatible SiGe HBTs are making rapid in-roads into RF through mm-wave circuit applications, with performance levels steadily marching upward, the use of these devices under extreme environment conditions are being studied extensively. In this work, test structures of SiGe HBTs were designed and put into extremely low temperatures, and a new negative differential resistance effect and a novel collector current kink effect are investigated in the cryogenically-operated SiGe HBTs. Theory based on an enhanced positive feedback mechanism associated with heterojunction barrier effect at deep cryogenic temperatures is proposed. The accumulated charge induced by the barrier effect acts at low temperatures to enhance the total collector current, indirectly producing both phenomena. This theory is confirmed using calibrated 2-D DESSIS simulations over temperature. These unique cryogenic effects also have significant impact on the ac performance of SiGe HBTs operating at high-injection. Technology evolution plays an important role in determining the magnitude of the observed phenomena, and the scaling implications are addressed. Circuit implication is discussed.

This thesis aims to determine effects of wearing textured insoles and compression socks on performance of dynamic interceptive actions in young skilled and less-skilled footballers. An ecological dynamics theoretical framework was addressed on how movement organisation patterns may be adapted in young individuals as a result of wearing textured and compression materials in shoes. Findings revealed that wearing textured and compression materials constrained movement organisation of skilled and less skilled football players and improved performance of kicking and ball reception task. This may occur through enhanced somatosensory system feedback utilised for foot placement and movement organisation of the lower limbs during complex and dynamic interceptive actions.

The case study was made in the area of Kiru Valley, Tanzania, in order to study the conflicts over the water in the river Dodumera, and also to understand how the villages Mawemairo, Matufa and Mapea have been affected by the construction of the IFAD irrigation scheme. The aim was to connect the conflicts in the area with a general view of how water can create such conflicts. The method used in the case study was semi-structured interviews. The results from the interviews made with farmers and officials in Kiru Valley was analysed through general theories about water conflicts and theories about governing common-pool resources, such as Ostrom’s eight principles and the theory the Tragedy of the Commons. The analysis was also made through the IFAD poverty reduction strategy programme (PRSP). The conclusion made on the basis of this analysis was that the IFAD project, in Kiru Valley, was in correlation with the PRSP and an attempt to reduce poverty in the two villages Mawemairo and Matufa. The project has been very successful and has contributed to an increase of livelihood and development in the villages. However, the scheme has also affected other villages, such as Mapea. The scheme has contributed to a decrease of water availability in the Dodumera River for Mapea. Nowadays they only rely on rain-fed irrigation. The conflicts have been affected by the scheme, not so much in the quantity of the conflicts but more in the target of the conflicts. Before the construction of the scheme the conflicts was directed at the big-scale farmers, now they are directed at the scheme. On the other hand, the scheme has helped reducing the conflicts between the farmers in Mawemairo and Matufa. There are solutions to conflicts and water scarcity, such as more efficient irrigation techniques and Ostrom’s principles on governing the common-pool resources.

The problem of heating the solar corona requires the conversion of magnetic energy into thermal energy. Presently, there are two promising mechanisms for heating the solar corona: wave heating and nanoflare heating. In this thesis, we consider nanoflare heating only. Previous modelling has shown that the kink instability can trigger energy release and heating in large scale loops, as the field rapidly relaxes to a lower energy state under the Taylor relaxation theory. Two distinct experiments were developed to understand the coronal heating problem: the avalanche effect within a multiple loop system, and the importance of thermal conduction and optically thin radiation during the evolution of the kinked-unstable coronal magnetic field. The first experiment showed that a kink-unstable thread can also destabilise nearby threads under some conditions. The second experiment showed that the inclusion of thermal conduction and optically thin radiation causes significant change to the internal energy of the coronal loop. After the initial instability occurs, there is continual heating throughout the relaxation process. Our simulation results show that the data is consistent with observation values, and the relaxation process can take over 200 seconds to reach the final relaxed state. The inclusion of both effects perhaps provides a more realistic and rapid heating experiment compared to previous investigations.

The natural dynamics are not ideal or linear. To understand their complex behavior, we needs to study the nonlinear dynamics in more simple models. This thesis is consist of two main setups. Both setups are simplified models for the behavior occurs in the complex systems. We studied in both systems the same nonlinear dynamics such as higher-harmonics, sub-harmonics, solitary waves,...etc. In Chapter (2), the propagation of nonlinear waves in a lattice of repelling particles is studied theoretically and experimentally. A simple experimental setup is proposed, consisting in an array of coupled magnetic dipoles. By driving harmonically the lattice at one boundary, we excite propagating waves and demonstrate different regimes of mode conversion into higher harmonics, strongly in influenced by dispersion. The phenomenon of acoustic dilatation of the chain is also predicted and discussed. The results are compared with the theoretical predictions of FPU equation, describing a chain of masses connected by nonlinear quadratic springs. The results can be extrapolated to other systems described by this equation. We studied theoretically and experimentally the generation and propagation of kinks in the system. We excite pulses at one boundary of the system and demonstrate the existence of kinks, whose properties are in very good agreement with the theoretical predictions, that is the equation that approaches, under the conditions of our experiments, the one corresponding to full model describing a chain of masses connected by magnetic forces. The results can be extrapolated to other systems described by this equation. Also, In the case of a lattice of finite length, where standing waves are formed, we report the observation of subharmonics of the driving wave. In chapter (3), we studied the propagation of intense acoustic waves in a multilayer crystal. The medium consists in a structured fluid, formed by a periodic array of fluid layerswith alternating linear acoustic properties and quadratic nonlinearity coefficient. We presents the results for different mathematicalmodels (NonlinearWave Equation,Westervelt Equation and Constitutive equations). We show that the interplay between strong dispersion and nonlinearity leads to new scenarios of wave propagation. The classical waveform distortion process typical of intense acoustic waves in homogeneous media can be strongly altered when nonlinearly generated harmonics lie inside or close to band gaps. This allows the possibility of engineer a medium in order to get a particular waveform. Examples of this include the design of media with effective (e.g. cubic) nonlinearities, or extremely linear media. In chapter (4), the oscillatory behavior of a microbubble is investigated through an acousto-mechanical analogy based on a ring-shaped chain of coupled pendula. Observation of parametric vibration modes of the pendula ring excited at frequencies between 1 and 5 Hz is considered. Simulations have been carried out and show spatial mode, mixing and localization phenomena. The relevance of the analogy between a microbubble and the macroscopic acousto-mechanical setup is discussed and suggested as an alternative way to investigate the complexity of microbubble dynamics.
La dinámica natural no es ideal ni lineal. Para entender su comportamiento complejo, necesitamos estudiar la dinámica no lineal en modelos más simples. Esta tesis consta de dos configuraciones principales. Ambas configuraciones son modelos simplificados de el comportamiento que se produce en los sistemas complejos. Estudiamos en ambos sistemas la misma dinámica no lineal como son la generación de armónicos superiores, los sub-armónicos, las ondas solitarias, etc. En elCapítulo (2), se estudia, tanto teórica comoexperimentalmente, la propagación de ondas no lineales en sistemas periodicos de partículas acopladas mediante fuerzas repulsivas. Se propone una configuración experimental simple, que consiste en una matriz de dipolos magnéticos acoplados. Inyectando armónicamente la señal en un extremo, excitamos ondas de propagación y demostramos diferentes regímenes de conversión de modos en armónicos, fuertemente influenciados por la dispersión. También se predice y se discute el fenómeno de dilatación acústica de la cadena. Los resultados se comparan con las predicciones teóricas de la ecuación FPU, describiendo una cadena de masas conectadas por muelles cuadráticos no lineales. Los resultados pueden ser extrapolados a otros sistemas descritos por esta ecuación. Estudiamos también teórica y experimentalmente la generación y propagación de kinks. Excitamos pulsos en la frontera del sistema y demostramos la existencia de kinks cuyas propiedades están en muy buen acuerdo con las predicciones teóricas, es decir, con la ecuación que aproxima bajo las condiciones de nuestros experimentos la correspondiente al modelo completo que describe un cadena de masas conectadas por fuerzas magnéticas. Los resultados pueden ser extrapolados a otros sistemas descritos por esta ecuación. Además, en el caso de una red finita, donde se forman ondas estacionarias, describimos la observación de subarmónicos del armónico principal. En el capítulo (3), estudiamos la propagación de ondas acústicas intensas en un cristal multicapa. El medio consiste en un fluido estructurado, formado por un conjunto periódico de capas fluidas con propiedades acústicas lineales alternas y coeficiente de no linealidad cuadrática. Presentamos los resultados de diferentes modelos matemáticos (ecuación de ondas no lineal, ecuación de Westervelt y ecuaciones constitutivas). Mostramos que la interacción entre la fuerte dispersión y la no linealidad conduce a nuevos escenarios de propagaciónde ondas. El proceso de distorsión de la onda clásica, típico de las ondas acústicas intensas en medios homogéneos, puede ser alterado de forma importante cuando los armónicos generados no linealmente se encuentran dentro o cerca del gap. Esto permite la posibilidad de diseñar un medio con el fin de obtener una forma de onda en particular. Ejemplos de esto incluyen el diseño demedios con no linealidad efectiva (por ejemplo, cúbica) o medios extremadamente lineales. En el capítulo (4), el comportamiento oscilatorio de una microburbuja se investiga a través de una analogía acusto-mecánica basada en una cadena en forma de anillo de péndulos acoplados. Se estudian los modos de vibración paramétrica del anillo pendular excitado a frecuencias entre 1 y 5 Hz. Se han llevado a cabo simulaciones que muestran la presencia de modos espaciales, mixtos y fenómenos de localización. Se discute la relevancia de la analogía entre una microburbuja y la configuración macroscópica acústico-mecánica y se sugiere como una vía alternativa para investigar la complejidad de la dinàmica de microburbujas.
La dinàmica natural no és ideal ni tampoc lineal. Per entendre el seu comportament complex, es necessita estudiar la dinàmica no lineal dels models més simples. Aquesta tesi consisteix en l'estudi de dues configuracions principals, que són models simplificats del comportament que es produeix en els sistemes complexos. Estudiem en ambdós sistemes la mateixa dinàmica no lineal, com és la generació d'harmònics superiors, sub-harmònics, ones solitàries, etc. En el capítol (2), estudiem, tant teòrica com experimentalment, la propagació de les ones no lineals en sistemes periòdics de partícules acoblades mitjançant forces repulsives. Es proposa una configuració experimental simple, que consisteixen en una matriu de dipols magnètics acoblats. En conduint harmònicament la xarxa en un límit, excitemla propagació de les ones i demostrem diferents règims de conversió de modes en harmònics més alts, força influenciada per la dispersió. El fenomen de la dilatació acústica de la cadena també es prediu i es discuteix. Els resultats es comparen amb les prediccions teòriques que descriu una cadena de masses conectades per molls quadràtics no lineals. Els resultats es poden extrapolar a altres sistemes descrits per aquesta equació. Hem estudiat teòrica i experimentalment la generació i propagació de Kinks. Excitem polsos a la frontera del sistema i demostrem l'existència d'Kinks, les propietats desl quals estan en molt bon acord amb les prediccions teòriques, és a dir, de l'equació que aproxima sota les condicions dels nostres experiments la corresponent al model complet que descriu un cadena demasses connectades per forcesmagnètiques. Els resultats es poden extrapolar a altres sistemes descrits per aquesta equació. A més, en el cas d'una xarxa finita, on es formen ones estacionàries, descrivim l'observació de subarmónicos de l'harmònic principal. En el capítol (3), s'estudia la propagació d'ones acústiques intenses en un medi multicapa. El medi consisteix en un fluid estructurat, format per una matriu periòdica de capes de fluid amb l'alternança de propietats acústiques lineals i coeficient de no linealitat de segon grau. Es presenten els resultats per a diferents models matemàtics no lineals (equació d'ones no lineal, equació de Westervelt i les equacions constitutives). Es demostra que la interacciò entre la forta dispersió i no linealitat condueix a nous escenaris de propagació de l'ona. El procés de distorsió en formad'ona clàssica, típica de les ones acústiques intenses en medis homogenis, es pot alterar de manera significativa quan els harmònics generats de forma no lineal es troben dins o a prop del gap. Això obri la possibilitat de dissenyar unmedi per tal d'obtenir una forma d'ona particular. Exemples d'això inclouen el disseny delsmedis amb una no linealitat efectiva (per exemple cúbica), o medis extremadament lineals. En el capítol (4), el comportament oscilatori d'una micro-bombolla és investigat a través d' una analogia acústica-mecànica basada en una cadena en forma d'anell de pèndols acoblats. Es considera l'observació dels modes de vibració paramètriques de l'anell pendular excitat amb freqüències entre 1 i 5 Hz. S'han dut a terme simulacions que mostren la presència de moes espacilas, mixtes i fenòmens de localització. Es discuteix la relevància de l'analogia entre les microbambolles i la configuració macroscòpica acústica-mecànica i es suggereix una formaalternativa per a investigar la complexitat de la dinàmica demicrobombolles.
Mehrem Issa Mohamed Mehrem, A. (2017). Nonlinear acoustics in periodic media: from fundamental effects to applications [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/80289
TESIS

La filière HEMT Métamorphique de part ses performances, apparaît très prometteuse pour les applications d'amplification pour les modules émetteur et récepteur des systèmes de télécommunications optiques longue distance et haut débit (50 Gbit/s). En effet, elle présente de bonnes performances en terme de bande passante (Ft > 160 GHz), de tenue en tension (> 8 V) et permet des possibilités de contrôle de gain efficace. Ce travail de recherche s'est déroulé dans le cadre du projet RNRT HEMERODE. Il a consisté à étudier expérimentalement les dysfonctionnements (effets parasites) liés au fonctionnement du MHEMT sur l'ensemble des structures disponibles. Un mécanisme d'ionisation par impact qui contribue à l'effet de coude (kink effect) et qui influe sur le lieu de claquage des transistors au travers de courants de grille en excès élevés a été observé. Une comparaison des résultats en fonction de la structure (simple ou double canal) et du recess de grille a été reportée. Les tensions de claquage en mode passant et en mode bloqué ont été mesurées et se sont avérées faibles, compte tenu de la forte influence du mécanisme d'ionisation par impact. Les MHEMT ont également été évalués en terme de mécanisme de piégeage/dépiégeage. Des mesures de gate-lag et de drain-lag ont mis en évidence la présence de pièges dont les signatures typiques de l'AlInAs ont été trouvées par mesure de relaxation isotherme. Ensuite, nous avons modélisé électriquement les différents effets parasites (excès de courant de grille, effet de kink, gate-lag et drain-lag) relevés lors des mesures expérimentales et les lieux de claquage des transistors. Ces modèles ont été développés à l'aide du logiciel ADS
Metamorphic HEMT, regarding its performances, appears very promising for amplification applications for the transmitter and receiver modules of long distance and high bit rate (50 Gbit/s) optical systems of telecommunications. Indeed, it presents good performances in term ofbandwidth (Ft∼160 GHz), ofbreakdown voltage (8 V) and allows possibilities of effective gain control. This research bas been developed within the framework of project RNRT HEMERODE. First, it consisted in studying, experimentally, the misfunctioning (parasitic effects) related to the operation of the MHEMT on the whole of the structures available. An impact ionisation mechanism, which contributes to the kink effect and influences the breakdown areas of the transistors because of excess gate current, was observed. A comparison of the results according to the structure (simple or double channel) and of the gate recess was reported. The "on-state" and "off-state" breakdown voltages were measured and appear to be weak, because of the strong influence of the impact ionization mechanism. The MHEMT were also evaluated in term of trapping/detrapping mechanisms. Measurements of gate-lag and drain- lag highlighted the presence of traps of which typical signatures of AlInAs were found by isothermal drain current relaxation experiments under gate filling pulses. Then we modelled the various parasitic effects (excess gate current, kink effect, gate-lag and drain-lag) obtained by experimental measurements and security area model of the transistors was defmed. These models were developed using ADS® software

L’objectif de cette étude est d’évaluer les potentialités des transistors HEMTs AlGaN/GaN pour l’amplification de puissance aux fréquences micro-ondes, à l’aide d’un banc de mesures I(V) et paramètres [S] en régime impulsionnel, et de proposer un modèle précis de ce type de transistors facilement implémentable dans les logiciels de C. A. O. Des circuits. Après un passage en revue des différentes technologies disponibles sur le marché pour l’amplification de puissance, les transistors HEMTs grand gap à base de Nitrures de Gallium apparaissent comme des candidats naturels pour ces applications (Figures de mérites de Johnson, …). Cependant, ces transistors plus que prometteurs ne sont pas exempts de défauts. En effet, plusieurs phénomènes limitatifs inhérents à la technologie GaN, à savoir l’auto-échauffement et les effets des pièges, doivent être pris en compte lors de la conception des circuits micro-ondes. Une étude de ces différents effets limitatifs en terme de puissance est effectuée. Enfin, un modèle non-linéaire électrothermique d’un transistor HEMT 8x125 µm est présenté, et validé à l’aide de deux banc de mesures fonctionnelles (banc Load-Pull et banc LSNA)
The aim of this study is to assess the potentialities of HEMTs AlGaN/GaN transistors for power amplification at microwave frequencies, thanks to a bench in pulsed I(V) and [S] parameters measurement, and to propose a precise model of this type of transistor easily implemented in circuit C. A. D software. After considering the different technologies available on the market for power amplification, wide gap HEMTs transistors based on Gallium Nitrides appear as natural candidates for these applications (Johnson’s Figures of Merit,…). However these more than promising transistors are not infallible. Indeed, several restrictive phenomena inherent to GaN technology, that is to say selfheating and trapping effects, must be taken into account in the process of designing microwave circuits. A study of these various restrictive phenomena in terms of power is carried out. Lastly, a non-linear electrothermal model of a HEMT 8x125 µm transistor is presented, and validated thanks to two functional measurement benches (Load-Pull Bench and LSNA Bench)

Aujourd’hui, la conception de circuits intégrés de puissance hautes fréquences large bande est devenue un enjeu majeur pour les systèmes modernes de défense. Nous proposons dans ce manuscrit une étude du transistor HEMT GaN afin de mettre en évidence son intérêt pour ces applications. Une conception d’amplificateur de puissance large bande 6-18 GHz sur substrat SiC est présentée, démontrant les potentialités de la filière GH25 d’UMS. Malheureusement, pour ces applications hautes fréquences, une étude démontre que le transistor HEMT AlGaN/GaN est limité par deux phénomènes : les effets thermiques et les effets de pièges. Ainsi, un modèle non-linéaire électrothermique incluant les effets de pièges d’un transistor HEMT 8x75 μm est présenté. Les caractérisations effectuées mettent en lumière les limitations des techniques actuelles de modélisation des pièges et nous permettront d’ouvrir de nouvelles perspectives dans ce domaine
Nowadays, the design of high-frequency broadband power integrated circuits is an important research axis in modern defense systems. This manuscript proposes a study about GaN HEMT in order to highlight its interest for these applications. The first part consists in design and measurement data of a broadband 6-18 GHz power amplifier. The obtained results demonstrate the performance of UMS GH25 technology based on SiC substrate. Unfortunately, for high frequency applications, AlGaN/GaN HEMT is limited by two phenomena that are thermal and trapping effects. Thus, a non-linear electrothermal model including these effects for a HEMT 8x75 μm is proposed. Some specific characterizations have shown limitations of current techniques for trap modeling and their analyses should open new perspectives in this field

Cette these presente une etude experimentale a temperature ambiante et aux temperatures cryogeniques de transistors a effet de champ a heterojonctions (hemts) inalas/ingaas/inalas en accord de maille et pseudomorphiques sur substrat inp, de longueur de grille submicronique. Malgre des performances microondes a l'etat de l'art, ces composants souffrent d'une technologie encore immature qui rend difficile une bonne reproductibilite de transistors performants. L'analyse des potentialites microondes sur la frequence de coupure du gain en courant de ces transistors revele que ces derniers s'ameliorent significativement avec la reduction de la longueur de grille et dans une moindre mesure avec l'abaissement de la temperature. L'absence d'evolution significative des capacites intrinseques avec la temperature confirme un bon confinement des porteurs dans le canal aux temperatures cryogeniques. Par ailleurs, la frequence maximale d'oscillation s'ameliore avec l'augmentation de la tension de drain, neanmoins l'utilisation des composants dans ces regimes de fonctionnement est limitee par la faible tenue au claquage des hemts sur inp. L'obtention de fortes densites de porteurs et des tensions de claquage elevees constituent les deux facteurs clef pour une montee en frequence encore plus importante. Les causes du claquage precoce de ces hemts sont etudiees de facon originale a partir de mesures d'electroluminescence. Celles-ci ont revele l'apparition d'un processus d'ionisation par choc dans le canal ingaas pour expliquer le claquage du composant. Par ailleurs, des anomalies ont ete observees sur les caracteristiques courant-tension. Ces anomalies sont la consequence de mecanismes de piegeage/depiegeage de porteurs dans les couches inalas et aux differentes interfaces. En conclusion, l'evolution des performances avec la temperature nous a permis de mieux comprendre les phenomenes physiques qui regissent le fonctionnement des hemts sur substrat inp a grille courte. L'etude a temperature variable s'est averee etre un outil precieux de caracterisation de l'ensemble de ces phenomenes

碩士
國立交通大學
電子工程系
89
In this thesis, we would investigate into the feasibility about using the characteristic, which Kink effect changes threshold voltage, to build a One-Transistor-DRAM and use a numerical simulator ”Medici” to determine “the holes produced by Impact Ionization would accumulate and induce Kink effect. ” or not. Chapter 1 gives the introduction of this thesis. In Chapter 2, we will illustrate the formation of Kink effect, which most people think. Generally speaking, the major reason of forming Kink effect is excess free holes can’t drain away immediately and accumulate at the bottom of SOI structure to rise body potential and induce body effect. Then, it would cause threshold voltage variation and then bring Kink effect. But is it true that the composition of Kink effect is as people said in general? If it is, the statement in general publications seems not match the principle of Electrical-Neutrality. In Chapter 3, we considered that excess holes would accumulate until reaching a forward bias voltage, which is provided by the buried oxide capacitor to ground. The voltage can forward bias the body-source junction and induce a proper current, which is equal to excess-holes flowing. As reaching equilibrium, the junction voltage would play a significant part on inducing Kink effect. The other part we assume to form Kink effect is the voltage drop of current flowing. But in our analytical-model results we can see the order is much less than junction voltage. Utilizing a numerical simulator “Medici” of Avant!, we found that the Kink effect doesn’t have huge influence when we modified the doping concentration at the bottom of SOI. So we can sure that Kink effect is dominated by junction voltage. Besides, it is worthy to know that the part of excess holes accumulated at bottom is extremely smaller than all excess holes induced by impact ionization, and is the cause of the extremely small value of buried oxide capacitor. Hence, the statement that Kink effect induced by accumulated holes seems not well. It is induced by the Quasi-Fermi potential, which is formed by excess holes flowing. Then, we try to derive the simulation model of Kink effect by our point of view. In Chapter 3 we will describe and derive the Kink effect model precisely. Based on the points of view as discussed before, we will discuss the feasibility about using Kink effect to build a One-Transistor DRAM. In Chapter 4, we will utilize this characteristic that Kink effect would modify threshold voltage, and build a larger potential barrier and buried oxide capacitor to trap more excess holes, to function the logic of DRAM. Hence, we don’t need a capacitor for this DRAM externally, that’s why we call it a “Single Transistor DRAM”. Finally, in Chapter 5, the major contribution of this thesis and future researches are summarized.

博士
國立臺灣師範大學
體育學系
104
Purpose: To improve kicking performance. This study analyzed the differences in kinematics and kinetics to understand the effects of arm movement on kicking. Method: Twenty-two male soccer players were recruited in this study (11 subjects in the first division, age: 22.2 ± 3.1, height: 172.5 ± 6.7, mass: 70.4 ± 13.9 kg, experience: 10.4 ± 3.2 years; 11 subjects in the second division, age: 25.2 ± 3.1, height: 173.4 ± 4.3 cm, mass: 69.8 ± 9.9 kg, experience: 7.0 ± 3.1 years). Vicon high-speed cameras (200 Hz) were used to capture 3D kicking motion. A Kistler force plate (1000 Hz) was used to measure ground reaction force. The Noraxon wireless electromyography system (1500 Hz) was used to acquire and measure surface muscle activity. Visual3D software was used to calculate the biomechanical parameters. Two-way ANOVA and t-tests were used to compare the ball velocity, segment linear velocity, joint angle, angular velocity, kinetics chain, area of center of pressure, and muscle activity between two kicking conditions and divisions. The statistical significance was set at α = .05. Result: Greater ball velocity was found in kicking with arm swing in first division players. The velocity was 27.2 ± 2.2 m/s and 24.4 ± 1.9 m/s with and without arm swing, respectively. No difference in ball velocity was found in second division players. The ball velocity was 21.2 ± 1.9 m/s and 20.2 ± 2.2 m/s with and without arm swing, respectively. Greater segment linear velocity, angular velocity, and range of motion were found in first division players when kicking with arm swing. Both first and second division players had a greater lean angle on the supporting foot and a longer time of thigh acceleration in the kinetics chain when kicking with arm swing. Muscle activity was similar between the two kicking conditions, but earlier onset of vastus lateralis activity was observed when kicking with arm swing in first division players. Conclusion: Arm swing increased the lean angle in the supporting leg, and provided better space for increasing segment velocity and angular velocity in the kicking leg. Ball velocity was improved by arm swing in first division players but not in second division players. Second division players can increase shank extension to improve ball velocity. When first division players kicked without arm awing, the thigh had less extension and the onset of vastus lateralis activity was earlier to assist knee external rotation and flexion in the kicking position.

碩士
臺北市立大學
競技運動訓練研究所
104
Purpose: The study was designed to explore the effect of self-verbal cueing on hitting rate of karate hook kick and roundhouse kick. Methods: Subjects were 10 collegiate karate kumite athletes and were assigned evenly into experimental and control groups. Experimental group had the one by one self-verbal intervention with the researcher one hour a week for six weeks. All subjects were tested on the hitting rate of designated and random hook kicks and roundhouse kicks with the pretest in the first week, midtest in the third week, and the posttest a week within the end of the intervention. Results: After six weeks of self-verbal cueing interventions, hitting rates of designated and random hook kick and roundhouse kick were all improved significantly. No difference was found between experimental and control groups on hitting rates of designated and random hook kick and roundhouse kick. Conclusion: Improvement on karate performance was observed after six weeks of self-verbal cueing intervention. Future research could recruit more subjects, and shorter cues should be designed for a better mastering of the skills.

碩士
逢甲大學
電子工程所
95
In this thesis, the characteristics of the InAlAs/InGaAs metamorphic HEMT by gate engineering have been studied. The gate structures included evaporating Au, Ni/Au, and Ni/Au with SiNx passivation. The In-rich channel of InAlAs/InGaAs MHEMTs have demonstrated excellent high frequency and low noise performance. However, high indium content of InGaAs-channel had the kink effects, low breakdown, and degraded power performance. In order to relieve the kink effects, evaporating nickel metal with high work function at the Schottky gate led to decrease the sheet carrier concentration and suppress impact ionization. Besides, we grown a SiNx passivation on the InAlAs Schottky layer with nickel metal which also contributed to repress kink effects and avoided surface trap generation. From experimental results, the Ni/Au gate exhibited the best high-frequency performance and the minimum noise. Besides, the SiNx passivation with Ni/Au gate showed the lowest output conductance, the highest voltage gain, the best linearity, breakdown voltage, and power performances. Consequently, the InAlAs/InGaAs MEMTs with Ni/Au gate and SiNx passivation is suitable for high-power with good linearity MMIC applications.

碩士
國立臺灣體育運動大學
體育研究所
104
The purpose of this study was to investigate the effects of counterattack timing on biomechanical characteristics of kicking leg in Taekwondo roundhouse kicks. Sixteen male college Taekwondo athletes were recruited as the participants voluntarily for this study. The mean age, height, body mass, and practice age of the participants were 20.5 ± 0.6 years old, 175.4 ± 4.9 cm, 64.5 ± 6.6 kg, and 10.1 ± 2.6 years, respectively. Each participant was asked to perform the front leg roundhouse kick under the condition of counterattack in active and passive randomly. Eight Vicon infrared digital cameras (MX-F40, 300 Hz) and four Kistler force platforms (9260AA6, 1500 Hz) were synchronized to acquire the kinematical and kinematical data respectively. The Vicon Nexus system (version 1.8.2) was used to calculate the joints angle, angular velocities, joints moment of kick leg. Repeated measures t tests were used to test the statistical differences for biomechanical parameters with the alpha level .05. The result showed that the kick leg takeoff delayed the leg takeoff of attacker 32.5 ± 41.2 ms in the active counterattack, and delayed 130.2 ± 76.0 ms in the passive counterattack due to take a step back. The flexion/extension moments and angular velocity of knee joint in the active counterattack were higher significantly than the passive counterattack. The findings of the study indicated that the Taekwondo athletes had to accelerate positively to execute an active counterattack perfectly. However, because the step back made the distance change between attacker and counterattacker in the condition of passive counterattack, the lower knee moment and angular velocity were the adjustable or controlled strategies to prepare for a counterattack efficiently.

碩士
國立臺北科技大學
機電整合研究所
102
Recently, that is an imperative method to introduce high-k materials replacing the conventional oxynitride to be gate dielectrics. However, with the technique development fast, the physical gate oxide thickness still come to a critical range for the gate leakage. Therefore, people must be to create or find out the more avant-garde technology to resolve that, the gate oxide issues of reliability. The experimental devices were fabricated from 28 nm node high performance logic technology of United Micro-electronics Corporation (UMC). The process of HfZrOx dielectric layer was deposited by atomic layer deposition (ALD) technology. The wafers were then annealed with different annealing temperatures and nitrogen concentrations after ALD. In this research, the different experimental temperatures (25℃, 75℃ and 125℃) and channel lengths (1 μm, 0.12 μm and 0.033 μm) are included in the experiment. In this study, the gated diode metrology with source terminal floating was adopted. The experimental results indicated that the drain current had a kink effect at VG = -0.62V, when the gate voltage (VG) was swept from –Vcc to 0V. In the contrary, it happened at VG = -0.64V when VG was swept reversely. In order to make sure this phenomenon, the different operating temperatures were raised and the analytical consequence showed that, it had a consistent trend with stress temperature. Therefore, we found that the kink effect is related with greatly gate-to-bulk tunneling leakage inducing the variation of junction width in the drain terminal. So, we observe that a similar “trapping and de-trapping” phenomenon was happened at this gate voltage point, inducing this kink effect of the drain current.

碩士
中國文化大學
體育學系運動教練碩博士班
100
Purpose: The study was to design a set of core muscle training and to investigate the effect of core muscle training on swimmers’ performance of dolphin kick. Methods: The subjects were 22 swimming athletes of Nei-Hu elementary school. All subjects’ average age, height and weight were 11.27 ± 0.75 years, 151.05 ± 7.26 cm and 42.45 ± 8.09 kg respectively. All subjects were divided randomly into core training group (n=11) and control group (n=11). The core training group accepted core muscle training three times per week for six weeks. All subjects were assessed 25 meters of dolphin kick test pre and post-training period. Mixed design two-way ANOVA was used to compare the results and statistics of pre-test and the post-test. Results: After six-week core muscle training, the statistics revealed core training group had significant progress in 25 meters of dolphin kick and indicated significant difference in effect between pre-test and post-test (p＜.05), and the range of progress were significantly greater than that of the control group.

碩士
國立彰化師範大學
運動學系
106
This study aims to compare the differences between taekwondo athletes who have or don’t have electronic protective and score system in term of the movement in roundhouse kicks. Twenty-one elite taekwondo athletes were recruited to the study. Also, six inertial sensors (Noraxon myoMotion, 200 Hz) and one 3D accelerometer (Noraxon DTS 24G, 1500 Hz) were used synchronously to acquire the lower limbs kinematic data, striking timing, and foot takeoff timing, respectively. Each participant was asked to stand in front of the cardboard cut-out and do the roundhouse kick for five times to the target. Independent samples t tests were conducted to determine whether there were significant differences between the participants who have or don’t have the Electronic protective and score system. The level of significance was set a priori at α = .05. The results showed that the athletes who have electronic protective and score system are slower than the athletes who don’t have the electronic protective and score system at the stage of foot takeoff because of the knee flexion. At the stage of hitting, the athletes who have electronic protective and score system are faster than those who don’t have electronic protective and score system. In terms of the angle of the right hip joint, the athletes who don’t have electronic protective and score system have higher angles of leg lifting. This study indicated that there were significant differences between the athletes who have or don’t have electronic protective and score system in term of the movement in roundhouse kicks

博士
國立成功大學
微電子工程研究所碩博士班
95
In this dissertation, we have successfully fabricated and investigated InAlAs/InGaAs high electron mobility transistors (HEMT’s) by employing different InxGa1-xAs channel designs and fabrication processes to improve the breakdown voltage and power characteristics. First, an InP etch stop layer was inserted on top of the InAlAs Schottky layer to improve the surface traps on the InAlAs layer and to alleviate the kink effects. Because increasing the carrier transport property and the threshold field for impact ionization in a linearly-graded channel structure, the LGC-HEMT has demonstrated high device gain of 342 mS/mm, high current drive capability of 360 mA/mm, low gate leakages of -2.0 μA/mm at VDS = 2V, low output conductance of 3.9 mS/mm, high voltage gain of 94.2, high output power of 12.43 dBm, and good thermal stability, as compared to those of the LMC-HEMT and ILGC-HEMT, respectively. Then, we’ve investigated the double ��-doped In0.425Al0.575As/In0.425Ga0.575As MHEMT’s. Since the energy band-gap of In0.425Ga0.575As channel is wider than that of the In0.53Ga0.47As channel in lattice-matched InP HEMT devices, the impact ionization phenomenon within the channel is expected to be reduced, thus relieving the kink effects. Consequently, the proposed double ��-doped MHEMT has shown low output conductance of 0.73 mS/mm, improved gate-drain breakdown voltage of -19.2 V, voltage gain of 402 and saturated output power of 18.28 dBm. Besides, the proposed MHEMT has also demonstrated superior high-temperature performance up to 500 K with positive thermal threshold coefficient (�gVth/�gT) of 0.39 mV/K. To facilitate the high-frequency applications, we have further investigated a ��-doped In0.45Al0.55As/InxGa1-xAs MHEMT by using a linearly-graded InxGa1-xAs (0.63→0.53) channel. Due to the high indium composition of the InxGa1-xAs channel, better carrier transport characteristics have been obtained to improve the transconductance and high-frequency characteristics. We have used the SiNx surface passivation and double-recess techniques to relieve the above-mentioned kink effects. Therefore, the propose MHEMT device has improved the extrinsic transconductance (gm) from 419 to 445 mS/mm, breakdown voltage from -7.7 to -13.1 V, output conductance (gd) from 17.7 to 6.3 mS/mm, voltage gain (AV) from 29 to 69, cut-off frequency (ft) from 55 to 61 GHz and maximum oscillation frequency (fmax) from 92 to 108GHz, the output power (Pout) from 14.33 to 18.91 dBm and the third-order intercept point (OIP3) from 19.3 to 28.2 dBm at 300 K, respectively. In addition, the device with double gate-recess has also demonstrated improved thermal stability with the deviations of gm,max and ID,max from 300 K to 500 K are only 18.8 % and 12.6 %, respectively. In addition to using the SiNx surface passivation and double-recess techniques, we’ve further investigated to relieving kink effects by using the ozone water oxidation treatment. The gate oxidation process provides a cost-effective method to deposit an about 8-nm thick oxide film with superior surface flatness in the gate structure of the MOS-MHEMT. In comparison, the proposed MHEMT with the ozone treatment has demonstrated improved peak gate leakage density from 59.5 μA/mm to7.1 μA/mm, breakdown voltage (BVGD) from -5.8 V to -14.9 V, output conductance (gd) from 33.1 to 4.5 mS/mm, voltage gain (Av) from 11.7 to 80.5, gate-voltage swing (GVS) from 0.45 to 0.9 V, output power (Pout) from 13.43 to 18.34 dBm and OIP3 from 15.8 to 26.1 dBm at 300 K, respectively.

碩士
國立臺灣師範大學
運動競技學系
105
Background: Poomsae is different from fighting and ball games in terms of the fact that its scores result from their own body movement. For example, in Taekwondo one scores after he/she hits the opponent; in basketball one scores after making the shot; in golf one scores when he/she putts the ball into the hole. Poomsae has its own specific rules about the starting and ending points of the movement, the trajectory of movement, and the spatial location. Therefore movement form is the primary evaluation criterion. Athletes sometimes pay special attention to their muscle control. The majority of coaches provide related information of body parts to instruct the skills in training or competition. However, those instructions are in contrast to the contemporary results of attentional focus studies. Therefore, this study intended to explore attentional focus in the learning of poomsae. Purpose: This study intended to compare the effect of internal focus and external focus on poomsae scores. Method: Twenty college students with no experience in either Taekwondo or poomsae learning, randomly assigned to an internal focus group, or an external focus group. The task was learning "Front kick" basic action. The learning effect was compared under the same task goal but different instructions of attentional foci. Results: There were significant improvements in the post-test performance for both groups. The external focus group, however, showed superior performance than the internal focus group for both post-test and transfer test. The normalized accuracy and presentation scores also showed the similar trend. Conclusions: The result of the study provide evidence to support the superior effect of the external attentional focus on learning the motor task that the movement form is of the primary goal such as Taekwondo poomsae action.

碩士
國立臺灣師範大學
體育研究所
89
The main purpose of this study is to investigate the effects of various knowledge of performance (KP) on the inside kick skill performance, which will show the difference of the precision of skill performance and performance quality. Sixty-four junior high first graders are served as subjects. Each subject proceeds a three-day motor skill practice under different feedback information. The subjects received a skill performance test right after they completed the third day practice. The independent variable was different KP, and the dependent variable was the precision score of the test and performance quality. One-way ANOVA with a LSD ( List Significant Different) posteriori comparison method was applied to analyze the collected data. The result showed: 1.Providing with different KP made a significant difference on the precision of the skill performance and performance quality of inside kick. 2.Verbal KP wasn’t good enough to help improve skill performance precision. Other feedback information, like demonstration or video KP is needed to improve precision. 3.Comparing to demonstration feedback, video KP feedback is a better way to improve the precision of inside kick skill performance and to produce better performance quality. 4.Providing video KP feedback makes a significant influence on the precision and the correctness of the skill of performance and performance quality of inside kick.

碩士
國立交通大學
顯示科技研究所
94
Abstract This thesis divided into two parts. First, we studied the grain control technology: heat retaining enhanced crystallization (H-REC). The heat retaining layer absorbs the laser energy and keeps providing heat to amorphous silicon film. Also the heat retaining layer slows down the heat dispersion. This heat retaining enhanced crystallization technology makes it possible to control the position of grain growth and enlarging the grain size, too. First, we proposed a new heat retaining material of the heat retaining enhanced crystallization. The novel heat retaining material: “diamond like carbon” (DLC). It shows great optical absorbance over a wide wavelength. Therefore, DLC can be used in the laser instrument nowadays, such as the shorter wavelength laser: excimer laser (308nm) and the longer wavelength laser: solid state laser (532nm). In out experiment, we successfully controlled the position of lateral growth grain crystallized by XeF laser (351nm) and the heat retaining material: DLC. The maximum grain size can achieve 1um. Moreover the crystallinity can be realized by the Raman characteristics for instance, the Raman peak position and full width at half maximum (FWHM) are 516.25cm-1 and 4.9cm-1 respectively. These reveal great qualities of crystallized film. Second, we studied in the grain affected high electric field effect in polysilicon thin film transistors: “Kink Effect”. Kink effect mainly caused by the avalanche multiplication in depletion region near the drain. So we take the multiplication factor as a reference parameter to represent the influence of kink effect. It is found that the multiplication factor is mainly affected by two factors: (i) grain boundary barrier height (EB) and (ii) grain size (LG). When the grain boundary barrier height increases, the local high electric field caused by grain boundary barrier is enlarged and the multiplication factor becomes larger. Moreover, when the grain size increases, the local high electric field is reduced and the multiplication factor is also becomes smaller. Increasing the laser energy can suppress the kink effect in both manners: (i) the grain boundary barrier height is reduced and (ii) the grain size is enlarged. Finally, we found that kink effect is less serious in solid state laser devices than in excimer laser devices. Since the polysilicon film crystallized by excimer laser has higher grain boundary barrier height than it crystallized by solid state laser. This also proves the proposed mechanism that: the grain boundary barrier height enlarges local electric field and enhances avalanche multiplication effect.

碩士
建國科技大學
自動化工程系暨機電光系統研究所
105
The back kick, being a higher technique, is an important attacking action in Taekwondo. Its characteristics are both fast and powerful to knock down the opponents. The advantage is that the contestants can win three scores from the trunk, and four scores from the head. The back kick would block continuous attack from the opponents, and even break their tempo. However, the ways of the back kick are multiform but in-depth research is sparse. Therefore, the purpose of this study was to understand the back kick velocity including minimum, maximum, and mean；and further, to analyze the action types of technical variations/imperfections with their different effects on kicking velocity. The research method was to analyze the kicking performance on fifteen taekwondo athletes (ages 17 to 20 years), based on biomechanical characteristics to execute data analysis from kicking is used as the research. The instrument of study used was Sony Cyber-shot DSC-RX100 digital camera, and After Effects cc capturing system. The study mainly utilized the statistical software SPSS (Statistical Package for the Social Science) version 21.0 to deal with the descriptive analysis,test, independent sample t test, and one-way ANOVA (Analysis of Variance), with a significance level of α= .05. The results showed that：1. The kicking velocity mean = .54s with the minimum = .46s and the maximum = .68s. 2. The frequency distribution of the action types of technical variations/imperfections is as follows support-foot moving 14 times (22％), stance-position squatting 24 times (32％), hip over rotation 15 (23％), 1800 turning with kick 36 times (42％), kick-foot unfolding without flexing the knee 26 times (34％). Thus, stance-position squatting was the primary factor in causing the action types of technical variations/imperfections from the back kick. 3. According to kicking velocity differences, the means were .52s and 55s, respectively. For this finding, there were fewer action types of technical variations/imperfections. The athletes would have faster kicking velocity and better sports performance by keeping things simple. 4. Here were the differences of kicking velocity in the action types of technical variations/imperfections. Support-foot moving could be one of the main factor in slowing the kicking velocity of the back kick. The conclusion was that proper execution of technique was needed to make corrections actively for enhancing sports performance and effective attacking levels. Therefore, the action types of technical variations/imperfections might clearly reveal athletic disadvantages. The suggestions of the author would indicate there will be a need for a systematic breakdown of each movement by experts and scholars so they could be standardized and made more effective.

碩士
國立體育大學
競技與教練科學研究所
107
During the competition, Taiji athletes often have difficulty movement in flying front snap kick and single leg landing. Most of junior and high school students can’t finish flying front snap kick and single leg landing because it’s difficult to them. If the athletes’ technical movement didn't enough, it would break their knee and ankle. For example, ACL, ankle injury et al. It also may impact Taiji athletes’ career. The better balance ability and pose stability not only can increase performance but also reduce low limb injury.The purpose of the research is to investigate the effect of hip stability training to Taiji athletes’ flying front snap kick and single leg landing. Method: the research will recruit 10 Taiji athletes as control group and 10 Taiji athletes as experiment group. All the subject will test their flying front snap kick+ single leg landing and half-kneeing balance to compare the difference between before and after hip stability training. Flying front snap kick + single leg landing and half-kneeing balance will be analaysis by Zebris 30. Results: all parameters showed no significant differences between two groups (sway length of balance: 100.17±31.27 vs 97.36±42.61, P =.53; sway velocity of balance: 33.41±10.31 vs 32.48±14.14, P =.502; sway length of jumping: 892.75±510.23 vs 921.96±774.96, P =.580; sway velocity of jumping: 446.43±255.10 vs 461.13±387.39, P =.580; performance during competitions: P >.05; experiment group vs control group; respectively). Conclusion: half-kneeing balance is not correlated either with the flying front snap kick and single leg landing technique or the performance during competitions.

碩士
國立臺灣大學
電子工程學研究所
96
This thesis reports the STI-induced mechanical stress-related kink effect behaviour of the 40nm PD SOI NMOS device. As verified by the experimentally measured data and the 2D simulation results, the kink effect behaviour in the saturation region occurs at a higher VD for the 40nm PD device with a smaller S/D length of 0.17μm as compared to the one with the S/D length of 1.7μm due to the higher body-source bandgap narrowing effect on the parasitic bipolar device from the higher STI-induced mechanical stress, offset by the impact ionization enhanced by the bandgap narrowing in the high electric field region near the drain.

碩士
國立體育大學
競技與教練科學研究所
107
The purpose of the study is to explore the accuracy and the power of the task, effects of different types of self-talk in Tae Kwon Do front roundhouse kick performance. The 30 participants are from National Taiwan Sports University Tae Kwon Do athletes. In the first time, we’ll teach the self-talk in two days. The experiment is divided into two task "accuracy task" and "power task". The participants were instructed to execute the fastest kick in accuracy task and the most powerful kicks in power task the outcome under three dialogue modalities of instructional self-talk, motivational self-talk, and non-related self-talk. The result showed that whether in precision task or power task, there is a significant difference between instructional self-talk, motivational self-talk and non-related self-talk. However, self-talk had significantly effect to the fastest kick task, and the instructional self-talk and the motivational self-talk had more significant effect than non-related self-talk. And there is no significant in instructional self-talk and motivational self-talk. The other hand, the self-talk had significantly effect to the most powerful kicks. The motivational self-talk had more significant effect than the instructional self-talk and non-related self-talk. And there is no significant in instructional self-talk and non-related self-talk.

碩士
臺北市立大學
競技運動訓練研究所
102
Purpose: The purpose of this study was to investigate the effects of different plyometric training on lower limb power, speed and axe kick of high school taekwondo athletes. Methods: 12 high school taekwondo athletes were chosen as subjects and are divided into two groups: forward jump training group (n = 6) and cross jump training group (n = 6). These two groups were respectively trained by forward jump training and cross jump training for two weeks with three times per week. The training volume for both groups was 140 times/day and the jumping height was at a height of 40 cm. Tests on counter movement jump (CMJ), 30-meter sprint and axe kick were conducted before and after the corresponding plyometric training. The results were analyzed by mixed two-way mixed design ANOVA so as to assess the performance of the two groups before and after the corresponding training. Statistical significance level was set at α = .05. Results: Regarding the CMJ and 30-meter sprint, there are no significant difference (p > .05) between the pre- and post-testing for both groups. Also, there was also no significant difference (p > .05) in interaction comparison; however, there was significant difference (pre-test 5.83 ± 0.34 sec., post-test 5.63 ± 0.23 sec., p &;lt; .05) in the performance of axe kick between the pre- and post-testing. Conclusion: Through 2-week plyometric training in stretch shortening cycle (SSC) stimulation mechanism, the axe kick speed of the trained taekwondo athletes was improved, which in turn significantly enhance the effectiveness of the attacks. Additionally, forward jump training session was relatively simple, safe and fluent. Recommendation: further research on single kick or turning kick may be conducted as a future work.

碩士
臺北市立大學
競技運動訓練研究所碩士在職專班
103
Purpose: This purpose this research were to compare the back of the prone leg curls with weight training weight lifting training for high school taekwondo athletes of lower limb power, agility run and the spin-kick hit the training effect on the differences in the case. Methods: The subjects were 12 (8 boys, 4 girls) high school taekwondo athletes and are randomly grouped into the back of the weight training group consisting of 6 people (4 boys, 2 girls) and prone leg curls weight training group consisting of 6 people (4 boys, 2 girls). Each group was trained through weight training back prone Leg lift weight training methods for 4 weeks, 3 days a week, the amount of training are all groups of 30 times / day , weight adjustment for individual maximum strength 70% by weight of the bars of the piece, and before training and after training were detected lower extremity power, agility run and spin kick hit special ability. The raw data was analysed by SPSS statistical software, 18.0 version. Before and after the test parameters for two-factor analysis of variance test measured before and after each group of lower extremity power (CMJ), agility run (20-meter shuttle run), the difference spin kick hit the special circumstances of detection capability results, and to explore the weight back differences training group and prone leg curls measured before and after the training group, all statistical tests are scheduled for a significant level of α = .05. Results : The lower extremity power(pretest 33.99 ± 6.20 cm, measured after 35.90 ± 6.80 cm), agility run(Pretest 5.48 ± 0.34 sec, measured after 4.77 ± 0.34 sec) and spin kick hit (pretest 0.53 ± 0.06 sec., after measuring 0.50 ± 0.05 sec.) achieve significant differences (p <.05). Conclusion: After four weeks of weight training, the performance of all the athletes in terms of the power of lower limbs, agility run and spin kick hit is improved significantly. v Key words: weight training, agility, leg training, high school taekwondo athletes, shuttle run

碩士
臺北巿立體育學院
運動科學研究所
94
Our country has been actively promoting TAE KWON DO sports for several years. Exercise is hypothesized to induce oxidative stress by a number of biochemical events. Exercise induced increases of metabolism rate and metabolic leak from mitochondrial electron transport chains are now thought to be the most important source of oxygen-derived radicals. The increase in oxygen uptake during exercise is accompanied by an elevation of reactive oxygen species (ROS) leading to oxdative stress. Oxidative stress has contributed to muscule and endurance fatigue. Exercise may also induce inflammatory reactions similar to the acute phase response occurring in injury or infection. Exercise is also associated with various degree of immune disturbance, with its severity depending on the intensity of exercise. T cell plays an important role in the human immune system, not only having the ability to carry on cytolysis function of the cell that suffered from the virus infection, but also having functions of regulating other immunocytes. Whey protein is thought to exert its effects that are by intracellular conversion of the amino acid cysteine to glutathione, a potent intracellular antioxidant. And the change of the GSH concentration can affect the activity of the T cell. We had investigated the effects of supplementation with whey protein on exercise performance, glutathione concentration, and T cell activity. Twenty-four distance running athletes were participated in this study. Pre-supplementation and 4 weeks post-supplementation with either Immunocal (20g/day) or none were studied. After dietary supplementation with whey protein, slightly increases in muscle ratio and muscle endurance were found, but not significantly. For the immune function part, the TH and TC cell counts and activities were both increased (p < .05). And the cytokine IFN-γ and IL-10 producing cells were significant reduced. In conclusion, after 4 weeks of supplementation with whey protein, the lymphocyte surface GSH concentration was raised, and TH cell and TC cell count and activity were stimulated. However, the numbers of INF-γ and IL-4 or IL-10 producing TH1 and TH2 cells respectively were both decreased under the higher concentration of GSH indicating that the effects of dietary whey protein supplementation on the immunological status of human can not be assessed only by a few kind cytokines production and thus need further investigation.

碩士
國立屏東教育大學
體育學系碩士班
101
The main objectives of this research were to investigate the performance effects of the imagery ability and imagery practice on the sixth grade sepak takraw beginners’learning about instep kick serving. The experiment participants (average age =11.7) are 45 sixth grade students(male=22、female =23). They are beginners with no experience in serving skills and imagery ability training. They are divided randomly into three groups, which are imagery training group, body-practicing group and controlled group. There were 15 students in each group. Before the pre-test of the ability of skill, according the scores they got from the test of Movement Imagery Questionnaire-revised（MIQ-R）, they are assigned into the higher imagery abilty team( the top 5 students), middle imagery abilty team and lower imagery abiltiy team(the last 5 students). After six weeks, twice a week practices, We held post-test and cognitive tests to understand that different groups, the level of imagery ability and different test time which affects the learning of the experiment participants more. The results are tested through three-way mixed design ANOVA. There were several results found by this study as follows: 1. Both imagery practice and physical practice contribute to the performance effects of skills and cognitive learning. 2.As to the effects of imagery practice , subject’s imagery ability is a important factor that influences skill learning and performance. 3. For simplicity,blocking skills ,subject’s imagery ability maybe not a important factor that influences skill learning and performance.

碩士
中國文化大學
體育學系運動教練碩博士班
107
Background and Motivation: Due to the complexity of offensive skills and the interference of the defensive players, it decreased the successful rate of scoring in the soccer game. When the offensive team met a standoff, Lace-Kick may be one of the optimal choices to score. Moreover, how to judge the level of soccer players in lack-kick performance focused mainly on the accuracy of kicking. In the past, the strength and technique training method in soccer always strengthened both two-legs strength (bilateral training) but neglected one foot (unilateral training). Purpose: This study aimed to investigate the effects of 6-week unilateral resistance training on the accuracy in Lace-kick and soccer-specific abilities in the young soccer players. Methods: 20 male soccer athletes were recruited as the experimental subjects (age = 16.7 ± 0.66 years old). The experimental intervention included three sessions of unilateral strength training per week with 5-day regular soccer training. The assessment was as below: Accuracy ability (lace-kick test), Agility (505 agility test), Speed (30 m sprint), and as well as Balance (Y-Balance Test: left foot standing, LYBT; and right foot standing, RYBT). The statistical method utilized the dependent sample t-test to compare all parameters before and after the unilateral training. The statistical significance was set as α= 0.05. Results: The results showed that all parameters appeared statistical significance in Accuracy of Lace-keck performance (t = 2.29, p = 0.034 <0.05), 30-Meter Sprint (t = -10.735, p = 0.002 < 0.05), Agility (t = -10.735, p = 0.000 < 0.05), Balance (LYBT: t = 14.64, p = 0.000 < 0.05; RYBT: t = 11.66, p = 0.000 < 0.05). Conclusion: After six-week unilateral training, young soccer athletes improved significantly in the accuracy of kicking, agility, speed, and balance.

碩士
國立體育學院
體育研究所
84
The purpose of the study was to combine goal orientation theory with cognitive evaluation theory to explore the effects of goal orientations and extrinsic rewards on intrinsic motivation, soccer''''s penalty kick. Subjects were 84 male technical school students who were high task / low ego oriented (n=42) and high ego / low task oriented (n=42) selected from 236 students participating in soccer class ( mean age = 16.1±.25 years ). Before the expriment, Subjects were randomly assigned to expected reward, un-expected reward, or no reward condition. Each condition was 14 subjects. The results were as follows: 　　Firstly, goal orientations and extrinsic rewards had the interactional effects on subjects intrinsic motivation. Specifically, high task / low ego oriented students in expected and no reward condition reported greater intrinsic motivation than high ego / low task oriented ones, but there were no difference in un-expected reward. Besides, high task / low ego oriented students in un-expected reward reported greater intrinsic motivation than those in expected reward. However, high ego / low task oriented students in un-expected reward reported greater intrinsic motivation than those in no reward and expected reward. In addition, no reward also reported greater intrinsic motivation than expected reward. 　　Secondly, goal orientations and extrinsic rewards had different effects on intrinsic motivation''''s perceived competence, enjoyment, pressure, and effort. High taskb / low ego oriented students reported more enjoyment, effort, and perceived less pressure than high ego / low task oriented subjects. during the penalty kick. In addition, subjects who were in un-expected reward reported higher perceived competence, more enjoyment, and less pressure than those in expected reward. 　　In summary, previous research in the physical domain examined the antecedent factors on intrinsic motivation has shown inadequate. The results indicated that individual''''s goal orientation was a very important variable in intrinsic motivation. Future study to examine different motivation theory on intrinsic motivation is warranted.