Zugl.: Hamburg, Techn. Univ., Diss., 2009

Thesis (Ph. D.)--University of Washington, 1987. / Vita. Bibliography: leaves [197]-202.

Thesis (M.S.)--California Polytechnic State University, 2009. / Title from PDF title page; viewed on Nov. 10, 2009. "June 2009." "In partial fulfillment of the requirements for the degree [of] Master of Science in Mechanical Engineering." "Presented to the faculty of California Polytechnic State University, San Luis Obispo." Major professor: John Ridgely, Ph.D. Includes bibliographical references (p. 91-97).

Abstract The purposes of the present research were to evaluate (1) the value of ultrasonographically guided fine-needle aspiration biopsy (US-FNAB) in nonpalpable suspicious breast lesions, (2) the preoperative use of methylene blue staining in nonpalpable galactographically suspicious breast lesions, (3) the determinants of positive histologic margins and residual cancer in wire-guided biopsy (WGB) of nonpalpable breast cancer and in lumpectomy for early breast cancer and the determinants of positive radiologic margins and the correlation between radiologic and histologic margins and residual disease in WGB of nonpalpable breast cancer, (4) the assessment of lumpectomy margins by touch preparation cytology in early breast cancer, and (5) the cosmetic outcome of WGB performed for benign breast lesions. The sensitivity and specificity of US-FNAB in 90 nonpalpable breast lesions were 84% and 93%, respectively. Preoperative methylene blue staining was successful in 22 out of 30 (73%) cases, making subsequent selective minimal volume microdochectomy easy to perform. Multivariate analysis of 21 prospectively evaluated variables was done after 71 WGBs of nonpalpable breast cancer followed by 54 re-excisions. Large mammographic lesions had more often positive radiologic margins. Multifocality, large pathologic size and superficial excision were related to positive histologic margins and multifocality to residual disease in re-excisions. The sensitivity and specificity of specimen radiography for predicting histologic margins were 38% and 81% and those for residual disease 27% and 79%, respectively. The corresponding figures for histologic margins in predicting residual disease were 85% and 59%, respectively. In a prospective series of 55 consecutive lumpectomies for early breast cancer, positive histologic margins were found more often in the presence of intraductal cancer and if the pathologic size of the index tumor was large. Residual disease was found in 38% of the cases with positive and in 15% of the cases with negative histologic margins. A multifocal and nonpalpable index tumor predicted residual cancer in 34 re-excision specimens. The sensitivity and specificity of touch preparation cytology in predicting histologic margins were 38% and 85%, respectively. In WGB, the overall cosmesis 6 months after surgery was satisfactory in 75 % of the 101 prospectively evaluated patients with benign proven lesions. Cosmesis was poorer after deep excisions and complications. The results indicate that US-FNAB is a useful tool in evaluating nonpalpable suspicious breast lesions. Preoperative methylene blue staining crucially facilitates selective minimal volume microdochectomy in three-quarters of cases. To obtain free margins in WGB, mammographically and pathologically large lesions should be removed with wider excisions extending down to the fascia. However, radiologic margins in WGB and histologic margins both in WGB and in lumpectomy for early breast cancer may be misleading. Re-excision of the biopsy site of multifocal tumors after WGB and lumpectomy should be considered. This is also important after superficial excision in WGB due to the considerable risk of residual disease. Touch preparation cytology cannot be recommended for the assessment of margins in lumpectomy specimens of early breast cancer. Cosmetic outcome after WGB of benign breast lesions is satisfactory in 75 % of cases. Deep excisions and complications endanger the cosmetic outcome. Preoperative biopsy and tumor localization methods have proven their utility; nevertheless, free margins are still difficult to obtain and to evaluate accurately. The surgeon may often be forced to choose between free margins and an acceptable cosmetic outcome.

The effect of uni-directional stress on the electrode potential of copper in aerated potassium nitrate solutions was studied. The influence of the variables time, temperature, concentration, magnitude of stress, mechanical condition of the metal, and pH was considered. The potential difference between two size #22 B & S copper wires was continuously recorded on a type G Speedomax automatic recorder. A balance pan was attached to one of the wires to which weights were added and the change in the potential difference between the two wires from the pre-stress potential difference was taken as the strain potential. At least four runs, using fresh pairs of wires for each run, were carried out to illustrate each specific point and to show the results have statistical significance and are reproducible. The following results were obtained: (A) Electronegative strain potentials have been obtained for copper metal in aerated potassium nitrate solution; these changes achieve a maximum at the instant of stressing and then decay with a negative acceleration with time. After an initial period of time, the strain potential decayed logarithmically with time. The magnitude of the electronegative strain potential for a given stress increased exponentially with the reciprocal of the absolute temperature and remained essentially unchanged for concentration changes ranging from 0.005N to 0.500N. (B) Experimental evidence was obtained to support the postulate that strain potentials of copper metal in aerated potassium nitrate solution and their time dependence parallel film rupture; the effect of the change in internal energy due to plastic deformation cannot be ignored. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

D.Ing. (Electrical And Electronic Engineering) / Please refer to full text to view abstract

With the recent push towards autonomous cars, a traditional steering wheel with its mechanical connection between the road and driver may soon be unnecessary. To facilitate interior design and lower production costs whilst still maintaining a manual alternative for maneuvering, an alternative steering input device relying on Steer-by-Wire technology is investigated. In order to finish the investigation and development of the steering device within the time-span of a master thesis, the limitation to only investigate the design of a hand wheel was established. The finished alternative steering device utilises an optical encoder for position measurement and a brushless direct current (DC) motor with a planetary gearbox for force feedback. Open-loop speed control proved to be insufficient with the available hardware. Instead, an approach of two PD-controllers regulating the angular error between the steering rack and the steering device was implemented successfully. Initially, mathematical models of the system components were derived and implemented in Mathworks Simulink. The transition from models to test rig implementation proved to be difficult due to unknown parameters in the hardware components such as embedded controllers in the steering gear and the internal works of the sensor emulator used to control the steering gear. By modifying parameters in accordance with system identification measurements performed on the test rig, the models could be validated. At the end of the project, a Volvo S60 was made available and the steering device was tested with real world driving. It was discovered that controllers tuned only for good reference following in the test rig did not translate to good driveability as the controller allowed for overly aggressive maneuvers. Following some in vehicle tuning, the proposed solution performed well during testing with surprisingly high drive-ability. For future iterations of similar hand wheel design projects, a user study was performed with regards to user experience, hand wheel size and perceived driveability.

Medium access mechanisms are one of the most important aspects of buses, which are shared mediums. Almost all standard buses use Time Division Multiple Access (TDMA) as their medium access scheme. Such buses usually are multi-wire, very sensitive to time synchronization, and often managed by a master node. In this thesis, we develop new non-TDMA schemes for bus communications which are based on Code Division Multiple Access (CDMA), or Frequency Division Multiple Access (FDMA) that do not have the intrinsic limitations of traditional buses. The proposed schemes are based on a single wire bus setting. Since, in theory, any node can have a dedicated communication link to any other node on the bus, the nodes virtually form a fully-connected mesh, hence the name Mesh-Bus. In such schemes, no master node is required on the bus; therefore, we can have a distributed bus in which all the nodes have the same functionality. Also, no time synchronization is required. Every node, using its unique code/frequency, creates a virtual private link to the other nodes, and using such interference-resistant virtual private links, the nodes communicate data to each other. This dissertation explores the underlying principals of such non-TDMA schemes and through extensive software simulations investigates various scenarios in for CDMA scheme, and studies the performance for the system. Finally, a hardware implementation of the CDMA scheme is presented, and some experimental results are provided to validate the simulation results.

The project deals with the effect of the airflow and temperature on the gold wirebond due to possible application in hot-wire anemometry. Theoretical fundamentals of wirebonding and hot-air anemometry are included in the text. From the area of anemometry, there is also a detailed description of measurement principles, areas of application and measuring instruments. The practical part of the text deals with design of the experimental sensor for hot-wire anemometry with use of the gold wirebond, including also the verification of the sensor's properties.

Quand des facteurs humains interviennent dans une large majorité des accidents de la route, l’amélioration de la sécurité routière passe par l’introduction de systèmes d’assistance, afin d’aider le conducteur dans les tâches de conduites les plus complexes. Les systèmes de conduites « by-wire », en facilitant le partage des tâches de conduites entre le conducteur et les systèmes d’assistance, représentent une avancée majeure vers une automatisation progressive de la conduite.Cependant, le déploiement de ces systèmes est freiné pour des questions de sûreté de fonctionnement, et nécessite la mise en œuvre d’outils de diagnostique pour détecter et corriger d'éventuelles défaillances. Dans le cadre de cette thèse, nous évaluons un algorithme de détection et de localisation des fautes compatible avec une architecture « by-wire », basé sur l’approche multi-modèles interagissants. Cette méthode nécessite l'estimation probabiliste de l’état du véhicule, pour laquelle différents observateurs non linéaires sont comparés. Pour cette démarche, l’accent est mis sur la validation expérimentale des résultats qui a nécessité l’équipement d’un véhicule de test.Une fois que la faute est localisée, nous étudions les différentes stratégies de contrôle du véhicule en fonction des actionneurs encore disponibles.Cette étude montre que les effets d'une défaillance sur les directions découplées sont particulièrement difficiles à corriger. / The improvement of the road safety implies to increase the place of driving assistance systems for road vehicles. Paving the road of the fully autonomous vehicle, the drive-by-wire technology could improve the potential of the vehicle control. The implementation of these new embedded systems is still limited, mainly for reliability reasons, thus requiring the development of diagnostic mechanisms to detect occurring faults. In a first step, we evaluate a fault detection and isolation algorithm, based on the interacting multiple models approach. The method relies on a probabilistic estimation of the vehicle state, for which different non-linear observer schemes are compared. The experimental validation required the preparation of a test vehicle.Then, when a fault is identified, the optimal back-up control strategies are investigated according to the availability of actuators.Thus study points out that faults on steer-by-wire systems are particularly difficult to treat.