A modified space vector modulation algorithm for a zero-voltage transition three-phase voltage source inverter/boost rectifier is presented. The converter is intended for high performance medium power applications requiring bi-directional power flow. The proposed modified space vector modulation allows the main switches to be operated with constant frequency and soft switching for any phase shift between the three-phase currents and voltages. The modulation algorithm also eliminates any low frequency distortion caused by the zero-voltage transition and can be extended to other soft-switching PWM three-phase converters. Experimental verification of the proposed algorithm is also presented as well as a comparison to the hard switched PWM converter. / Master of Science

La rugosité est une propriété clé des sols qui contrôle de nombreux processus de surface et influence la fonction de diffusion du rayonnement incident, alias sa BRDF (Bidirectional Reflectance Distribution Function). Bien qu’elle dépende fortement de l’échelle spatiale, la rugosité est souvent considérée comme stationnaire dans les modèles photométriques de réflectance de surfaces. En particulier, celui de Hapke l’inclut sous la forme d’un angle de pente moyen, intégré sur toutes les échelles variant de la taille d’un grain du régolithe à celle de la topographie locale. Le sens physique de ce paramètre de rugosité moyenne est largement débattu car l’échelle n’est pas clairement définie. Cette thèse a pour objectifs de comprendre comment la rugosité moyenne peut décrire un phénomène multi-échelle et d’investiguer l’influence des échelles spatiales de rugosité sur la BRDF d’une surface. On teste notamment la capacité du modèle de Hapke à restituer par inversion de la BRDF une rugosité moyenne compatible avec la réalité terrain. La topographie de terrains volcaniques et sédimentaires du Piton de la Fournaise (île de La Réunion) et du rift d’Asal-Ghoubbet (République de Djibouti) a été mesurée par photogrammétrie haute résolution sur une large gamme de résolutions à partir de données multi-instrumentales : images satellite, drone et acquises manuellement. Leur BRDF a été mesurée en parallèle par Pléiades et par un spectro-goniomètre (appelé Chamelon), et simulée numériquement par tracé de rayon sur les MNT réalisés. Une analyse multi-échelle par transformée en ondelettes révèle le comportement multi-modal de la rugosité des surfaces étudiées et permet de montrer que les structures sub-centimétriques dominent à la fois le paramètre de rugosité intégré et la forme de la BRDF. La rugosité estimée par inversion sur les données simulées avec une version simplifiée du modèle de Hapke coïncide avec celle déterminée sur les modèles de surface lorsque les hypothèses du modèle sont respectées et l’albédo connu à priori. L’adéquation n’est pas systématique mais reste bonne dans le cas de terrains à rugosité modérée avec une version complète du modèle de Hapke / Surface roughness is a key property of soils that controls many surface processes and influences the scattering function, or BRDF (Bidirectional Reflectance Distribution Function), of incident radiation. While it is strongly scale-dependent, it is often considered as a stationnary parameter in photometric models. In particular, it is included in the Hapke model as a mean slope angle, integrated over all scales from the grain size to the local topography. Yet its physical meaning is still a question at issue, as the scale at which it occurs is undefined. This thesis aims at understanding how this mean parameter can describe a multiscale phenomenon and to investigate the role of spatial scale on surface BRDF. Finally, we investigate the ability of the Hapke model to retrieve a roughness parameter which is consistent with the ground truth. The topography of volcanic and sedimentary terrains in the Piton de la Fournaise (Réunion Island) and the Asal-Ghoubbet rift (Republic of Djibouti) has been measured using high resolution photogrammetry at a wide range of resolutions thanks to multi-instrumental data : satellite, drone and handheld images. Simultaneously, the BRDF has been numerically simulated, and measured by satellite and a spectrogoniometer (named Chamelon). A multiscale analysis by the means of the wavelet transform reveals the multi-modal behavior of roughness and shows that sub-centimeter surface features dominate both the integrated parameter and the shape of the BRDF. The roughness estimated by inversion of a simplified version of the Hapke model matches the roughness determined over surfaces when the assumptions of the model are verified, with a priori knowledge on surface albedo. The match is not systematic, but remains good for moderately rough terrains using the full Hapke model

Modern health care systems are information dense and increasingly relying on computer-based information systems. Regrettably, many of these information systems behave only as an information repository, and the interoperability between different systems remains a challenge even with decades of investment in health information exchange standards. Medical records are complex data models and developing medical data import / export functions a is difficult, prone to error and hard to maintain process. Bidirectional transformations (bx) theories have been developed within the last decade in the fields of software engineering, programming languages and databases as a mechanism for relating different data models and keeping them consistent with each other. Current bx theories and tools have been applied to hand-picked, small-size problems outside of the health care sector. However, we believe that medical record exchange is a promising industrial application case for applying bx theories and may resolve some of the interoperability challenges in this domain. We introduce BXE2E, a proof-of-concept framework which frames the medical record interoperability challenge as a bx problem and provides a real world application of bx theories. During our experiments, BXE2E was able to reliably import / export medical records correctly and with reasonable performance. By applying bx theories to the medical document exchange problem, we are able to demonstrate a method of reducing the difficulty of creating and maintaining such a system as well as reducing the number of errors that may result. The fundamental BXE2E design allows it to be easily integrated to other data systems that could benefit from bx theories. / Graduate / 0984

The purpose of this study was to examine the bidirectional effects of simulated driving and conversations using different speaking modalities. Participants included 30 males and 30 females with no history of speech, language or hearing disorders. The participants were divided into three age groups: 20s, 40s, and 60s. They completed a driving simulation task in isolation and also while speaking on a hand-held or hands-free cell phone or with a passenger in the car. Speech measures included speaking time ratio, mean, and standard deviation of intensity, as well as mean and standard deviation of fundamental frequency in semitones. Driving measures included standard deviation of lane position, mean, and standard deviation of speed, standard deviation of steering wheel position, and the average number of steering wheel turns. There were significant effects of speaking while driving on mean intensity, speaking time ratio, standard deviation of steering wheel position, and the number of steering wheel turns. There were significant gender effects for speaking time ratio, standard deviation of intensity, and mean intensity, with the females having higher speaking time ratios, and the males having a higher standard deviation and mean of intensity. There was a significant age effect for mean fundamental frequency, standard deviation of lane position, and the standard deviation of steering wheel position. For mean fundamental frequency, the 60s group were lower than the 20s group. The 60s group had a higher standard deviation of lane position and standard deviation of steering wheel position. These findings reveal effects on both speaking and driving performance when speaking and driving concurrently. This has potential clinical implications for planning therapy activities that will help individuals generalize their learned skills from quiet, distraction-free clinic rooms to more realistic situations with distractions and background noise.

Discrete Cosine Transform (DCT) is widely used transform in many areas of the current information age. It is used in signal compression such as voice recognition, shape recognition and also in FBI finger prints. DCT is the standard compression system used in JPEG format. The DCT quality deteriorates at low-bit compression rate. The deterioration is due to the blocking artifact inherent in block DCT. One of the successful attempts to reduce these blocking artifacts was conversion of Block-DCT into Line-DCT. In this thesis we will explore the Line-DCT and introduce a new form of line-DCT called Bidirectional-DCT, which retains the properties of Line- DCT while improving computational efficiency. The results obtained in this thesis show significant reduction in processing time both in one dimensional and two dimensional DCT in comparison with the traditional Block-DCT. The quality analysis also shows that the least mean square error is considerably lower than the traditional Block-DCT which is a consequence of removing the blocking artifacts. Finally, unlike the traditional block DCT, the Bidirectional-DCT enables compression with very low bit rates and very low blocking artifacts.

The charge equalization for the battery power source with battery power modules (BPMs) in series is presented in the thesis. The bidirectional power converters in BPMs are able to serve as chargers with buck conversion during the charging stage. Even though connected in series, all modules can substantially be operated individually, retaining the advantages of independent operation, such as flexible control, easy protection, simple maintenance, and favorable battery power management. Investigation results indicate that automatic charge equalization is possible for the discontinuous conduction mode (DCM) operation. On the other hand, charge equalization can be achieved much faster by individually regulating the charging currents at the continuous conduction mode (CCM). According to the analyzed results, an equalization strategy is proposed to solve the charge imbalance problem by scheduling the individual battery current. Experiments are carried out to demonstrate the effectiveness of charge equalization.

The primary target of this paper is to fabricate bidirectional transceiver modules based on single mode fiber (SMF) and ultra-thin thin-film filter (TFF). Two major components, namely, SMF and ultra-thin TFF are hybrid integrated on the silicon bench using V-groove and U-groove techniques. A 1310 nm wavelength light was launched into the input SMF of the module. After passing through the filter, the light was received by the output SMF of the module. On the other hand, a 1550 nm wavelength light input to the SMF is reflected by the filter and collected by the output multimode fiber (MMF). Transceiver modules using two different fiber structures were fabricated. The first kind of the module uses standard SMF for 1310 nm light transmission. The insertion loss of the module for the 1310 nm wavelength light was 5.66 dB. In the second kind of the module lens fibers were used to replace the standard SMF. The insertion loss for the 1310 nm wavelength light was reduced to 0.98 dB. A reduction of 4.6 dB was achieved. For both modules, the insertion loss for the 1550 nm wavelength light reflected from the filter was around 0.5 dB.

In the AcMNPV genome, ~28% of the genes are arranged divergently on opposite strands with an intergenic region of <1 kbp. In this configuration, a bidirectional promoter generally drives expression of both genes. However, no baculovirus bidirectional promoters have been characterized in any detail. We chose the AcMNPV chiA/v-cath intergenic region to serve as a model to characterize transcriptional regulation of bidirectional gene pairs during AcMNPV infection. We sequentially truncated putative upstream regulatory regions of chiA and v-cath to identify sequences essential for transcriptional initiation. Forty bp of the chiA gene 5’-flanking region was sufficient to support chiA transcription at half the level of the AcΔCC+CC repair virus. Interestingly, v-cath transcription from viruses containing only 40 bp of their upstream 5’-flanking region was found to be higher by 4-fold relative to the level of native expression. Linker-scanning mutagenesis that inserted 5 bp linkers spanning the chiA/v-cath intergenic region identified nucleotides critical for the transcriptional activation of both genes. From this, nucleotides -36 to -45, of the v-cath gene were found to negatively regulate v-cath mRNA expression. Quantitative RT-PCR studies revealed a 2-4 fold higher chiA mRNA expression relative to v-cath possibly explaining why translation of CHIA can be detected 6 hours earlier than V-CATH. This study identifies upstream regions of viral chiA and v-cath required for initiation of transcription and provides the first insight into baculovirus mechanisms for transcriptional regulation of interdependent gene pairs.

This thesis is an investigation of rules which are historically conceptualized as static and unidirectional constructs strictly enforced by parents. This behavioural perspective is focused on parents as active agents and children immediately obey parental requests (Patterson, 1982). In contrast, a developmental perspective was used in this study in which rules are flexible and coconstructed by parents and children (Parkin & Kuczynski, 2012). Forty families participated in open-ended interviews; each family had one child between the ages of eight and thirteen. A thematic analysis was conducted and results suggested that rules were constructed by a bidirectional process in which parents and children were active agents. Parents most commonly perceived the rules to be flexible, coregulated and inherent - few parents described firm and explicit rules. Rules were developed by negotiation, based on the child’s development and by accommodating external influences. Leeway was an inherent, expected component of parent-child interactions

This master thesis presents an experimental design of a laser gyroscope based on a stabilized fiber optical parametric oscillator frequency comb and the results of testing of the proposed design. Before going into the experimental details, a background for different types of gyroscopes is discussed. This new laser gyroscope design is made up of only polarization maintaining (PM) fiber and PM fiber components. By using only fiber and fiber components, we were able to minimize size, weight, and alignment issues that are typical in bulk optical designs for OPO's and gyroscopes. The fiber-based OPO produces counter propagating ultrafast pulses that overlap only twice in the cavity, resulting in a beatnote signal when combined outside of the laser cavity. A mode-locked laser is used as a pump source so the lock-in effect (or deadband region) is avoided for the experiment. The drift of this beatnote signal represents the rotation sensitivity of the experimental setup. Issues seen in past iterations, such as stability of mode-locked pump source and beatnote drift overtime due to environmental variables, have been reduced in this experiment. This has been done by comprising the entire pump source of PM components, and by placing the entire setup in an insulating box to minimize acoustic and temperature fluctuations. By creating a frequency comb and locking the laser gyroscope to an optical clock, this experiment can be used for very precise rotation sensing in comparison to other gyro designs currently available.