The research presented in this thesis describes a substantial part of the design of a prototypical surgical training simulator. The results are intended to be applied in future simulators used to educate and train surgeons for bone milling operations. In earlier work we have developed a haptic bone milling surgery simulator prototype based on three degrees-of-freedom force feedback. The contributions presented here constitute an extension to that work by further developing the haptic algorithms to enable six degrees-of-freedom (6-DOF) haptic feedback. Such feedback is crucial for a realistic haptic experience when interacting in a more complex virtual environment, particularly in milling applications.The main contributions of this thesis are:The developed 6-DOF haptic algorithm is based on the work done by Barbic and James, but differs in that the algorithm is modified and optimized for milling applications. The new algorithm handles the challenging problem of real-time rendering of volume data changes due to material removal, while fulfilling the requirements on stability and smoothness of the kind of haptic applications that we approach. The material removal algorithm and the graphic rendering presented here are based on the earlier research. The new 6-DOF haptic milling algorithm is characterized by voxel-based collision detection, penalty-based and constraint-based haptic feedback, and by using a virtual coupling for stable interaction.Milling a hole in an object in the virtual environment or dragging the virtual tool along the surface of a virtual object shall generate realistic contact force and torque in the correct directions. These are important requirements for a bone milling simulator to be used as a future training tool in the curriculum of surgeons. The goal of this thesis is to present and state the quality of a newly developed 6-DOF haptic milling algorithm. The quality of the algorithm is confirmed through a verification test and a face validity study performed in collaboration with the Division of Orthopedics at the Karolinska University Hospital. In a simulator prototype, the haptic algorithm is implemented together with a new 6-DOF haptic device based on parallel kinematics. This device is developed with workspace, transparency and stiffness characteristics specifically adapted to the particular procedure. This thesis is focuses on the 6-DOF haptic algorithm. / QC 20120226

Des de l'inici de la meva activitat laboral a final dels anys setanta he viscut experiències de implantació de Equips de Millora en diverses empreses del nostre entorn industrial, algunes de les quals formaven part de grups multinacionals. Aquestes experiències seguient els mètodes de diversos experts internacionals. Malgrat els esforços esmerçats en el llançament, en molts casos aquests no es veien recompensats pels resultats obtinguts, i l'activitat dels Equips s'anava progressivament abandonant. Tanmateix els experts, tant els tècnics com els psicòlegs industrials, han continuat sempre afirmant la bondat d'aquestes pràctiques, que s'ofereixen en el mercat sota denominacions com «Mètode Juran», «Mètode Deming» o «Six Sigma».¿Perquè una activitat en teoria tant beneficiosa és tan difícil de portar a la pràctica? ¿Quins són els factors que afavoreixen l'èxit i la continuïtat dels Equips?L'estudi de les principals metodologies disponibles en el mercat, dels mecanismes del procés d'aprenentatge, de les informacions aportades per un grup de 15 empreses, i de la experiència pròpia en una empresa pilot ens ha permès proposar i provar un model que dona resposta a les preguntes exposades.Fins on hem vist totes les metodologies proposades pels experts tenen un tronc comú, que correspon al que també coneixem com mètode científic, de manera que es poden considerar com variacions d'aquest. Si l'èxit dels Equips no depèn del mètode, doncs tan sols n'hi ha un, haurà de dependre de aspectes complementaris al mètode. Com que es tracta de emprar el mètode científic en una empresa, els aspectes de contorn seran aquells lligats a les condicions de treball en les empreses, i específicament al factor humà i a les complexitats tècniques i de relació del dia a dia. Hem après que en aquest context les persones ens comportem com si genèticament (memèticament) tinguéssim un mecanisme de rebuig a tota mena de canvis en el nostre entorn laboral, anàleg al mecanisme genètic de rebuig del nostre sistema immunològic. També hem après que les complexitats psicològiques i tècniques augmenten les probabilitats de cometre errors, la qual cosa juga a favor del mecanisme de rebuig esmentat.Per tant si volem augmentar les probabilitats d'èxit i de continuïtat haurem de prestar atenció a neutralitzar aquest sistema immunològic mental i a involucrar especialistes en navegar per les complexitats, tant tècniques com psicològiques.Basant-me en aquests fets he desenvolupat un model per a la implantació de programes de millora a les organitzacions que contempla tant els aspectes tècnics, com organitzatius i humans, que és la principal contribució de la tesi i que ha estat posat en pràctica amb èxit a la empresa pilot.La «autopoièsi», que és com hem anomenat aquest fenomen de resistència innata als canvis, l'hem combatut amb la única eina que hem trobat eficaç : les tècniques de comunicació. La complexitat l'hem afrontat amb persones expertes en pensament sistèmic, i en mètode científic i les seves eines estadístiques. A aquests experts els hem anomenat Facilitadors. Amb aquests elements en un any hem aconseguit completar 28 projectes de millora, que han tingut uns beneficis bruts superiors a 2.5 Milions d' , amb un cost total de 0.75 Milions d' . Això significa una relació Benefici/Cost de 3.3, o bé una rendibilitat financera equivalent mitja del 73% o del 184% en el casos més desfavorables de càlcul dels beneficis, i depenent del tipus de Equip utilitzat.Considero els resultats prou engrescadors, tot reconeixent les limitacions de una prova restringida a una sola empresa. Per a mi és clar que aquest tipus de activitat és molt rendible en termes relatius, i lamentablement també ha quedat clar que l'autopoièsi es extremadament potent: a l'empresa hi ha persones que han continuat sempre negant la evidència dels resultats aconseguits, malgrat estar aquests validats pel departament financer. Tot i les dificultats l'activitat continua, i ja portem 3 anys. / From the beginning of my professional life at the end of the seventies I've witnessed Quality Improvement Teams implementation experiences in several companies of my industrial environment, most of them belonging to multinational groups. Those experiences were implemented following models proposed by international experts. In most cases the efforts spent in launching those activities very rarely were compensated by good results, and thus Teams activity was progressively abandoned. But both technical experts and psychologists still continued claiming the adequation of such methods, that are available in the market under names such as «Juran Method», «Deming Method» or «Six Sigma».¿Why such in theory good practices are so difficult to implement in real life? ¿Which are the factors that will facilitate us to achieve implementation success and continuity of Improvement Teams activity?The analysis of the most popular «methodologies» available in the market, of learning processes mechanisms, of informations supplied by a group of 15 companies, and of our own pilot experience in a company has allowed us to propose and test an implementation model that enables us to respond the exposed questions.As far as we've seen all the methodologies proposed by the experts have a common structure, that corresponds to what we also know as «scientific method», and so all the methods can be taken as variations of it. So, there's only one method. If Teams success does not depend on the method (there's only one, so no choice), it must depend on complementary aspects. Since we're trying to use scientific method in a company, the complementary aspects will surely be those reflecting the working environment in a company, and specifically the human factor and the technical and relational complexities of the day to day life. We've learnt that in this context people behave as we all had a genetic (memetic) mechanism of rejection of all kind of changes in our working environment, in analogy to our inmunologic rejection genetic mechanism. We've also learnt that psychological and technical complexities increase our risk of making mistakes, which is something in favour of the rejection mentioned mechanism, and thus preventing success.So if we want to increase the success and continuity probabilities we will have to devote special attention to neutralise the effects of this mental inmunologis mechanism and involve specialists in «navigate complexities», both technical and psychological.Based on those facts I've developed an Organisational Improvement Program implementation model, taking into account technical, organisational and human behavioural aspects, being this model the main contribution of this work. The model has been successfully implemented in a pilot company.We've fought «autopoiesis» (this is how we've called the change rejection mechanism) with the only effective tool we've found : communication techniques. We've faced complexity with the help of experts in systems thinking, and scientific method and its statistical tools. We've called those experts Facilitators. With those elements in one year we've managed to close 28 team improvement projects, with total gross savings higher Than 2.5 Million , with a total cost of 0.75 Million . That means a ratio Benefit/Cost of 3.3, or a financial equivalent mean profitability of 73% or 184% using the less favourable savings calculation way, and depending of the Team type used.I consider that those results are exciting enough, while recognising the limitations linked to a pilot test in one company alone. It is clear for me that this kind of approach is very profitable in relative terms, and is for me disappointingly clear that autopoiesis is extremely powerful : there are still in the pilot company many people that continue to negate the evidence of the results achieved by the Teams, in spite of having been validated by finance department. Though Teams are still working after 3 years.

Nowadays high speed and high data rate communication are highly demanded. Consequently, wideband and high frequency transmitter and receivers should be designed. New transmitters and receivers should also have low power consumption, simple design and low manufacturing price in order to fulfill manufacturers’ requests for mass production. Having all above specifications, six-port correlator is a proper choice to be used as modulator and demodulator in transmitters and receivers. In this thesis the six-port correlator is introduced, modeled and simulated using Advanced Design System (ADS) software. A simple six-port transmitter/receiver system with a line of sight link is modeled and analyzed in BER, path length and noise terms. The modulation in this system is QAM, frequency is 7.5 GHz and symbol rate is 500 Msymbol/s. Furthermore two methods are proposed for high frequency and high symbol rate M-PSK and M-QAM modulation using six-port correlator. The 7.5 GHz modulators are modeled and simulated in ADS. Data streams generated by pseudo random bit generator with 1 GHz bandwidth are applied to modulators. Common source field effect transistors (FETs) with zero bias are used as controllable impedance termination to apply baseband data to modulator. Both modulators show good performance in M-PSK and M-QAM modulation.

In modern telecommunication there is the demand of high data rates using wideband component design. FCC has introduced the UWB spectrum for high speed data communication. UWB systems have attracted the attention of researchers.  Six-port transmitters and receivers are strong candidates for UWB systems and research is being done on six-port modulators and demodulators. In this work an effort is made to compare the performance of conventional single-ended six-port transmitter and receiver with differential six-port transmitters and receivers.    In this thesis, single ended and differential six-port correlators are designed on 7.5 GHz using Agilent Inc. EDA tool ADS and their performance is evaluated. A new wide-band differential six-port correlator is implemented using rat-race couplers and double-sided parallel strip-line phase inverter. The designed six-port correlators are used for 8-PSK modulation and demodulation. For transmitter-receiver system, mixed analog-DSP designing is used. The integral components of the system are evaluated individually and behavioral modeling is used to evaluate the complete transmitter-receiver system. The single-ended and differential systems are evaluated for noise-figure, dynamic range, bit error rate and data rate.

No description available.

Efficient functioning of service providing organizations highly depends on quality of their services as it contributes to companies’ competitiveness and customers’ satisfaction (Gill, 2009, p. 533). Thus, quality management should be an integral part of service organizations’ performance. Healthcare industry is a specific representative of the service industry that regards quality as a fundamental value of medical care. To manage quality within the healthcare settings is a challenging task due to its complexity. Hence, the purpose of the current qualitative study was to propose an efficient approach toward quality management within the healthcare industry. In order to be efficient quality management should consider issues that relate to the healthcare organizations’ complexity such as different interests of a wide range of parties involved in healthcare service processes. As mentioned parties are presented by patients, physicians, nurses, receptionists and others, their perceptions of quality could be rather distinctive. So, the first step towards achieving the purpose of the study was to discover an aligned or combined perception of healthcare service quality from patients’ and healthcare service providers’ perspectives. Common perception of quality would give opportunity to focus on improvement of aspects that are essential for the core stakeholders of healthcare organizations. Hence, the second intention that would contribute to efficient quality management was to develop a combined quality management model based on an aligned or combined quality perception. In order to investigate a common perception of quality, we conducted semi-structured individual interviews with patients and healthcare service providers. Having analyzed obtained data we revealed the most vital (sub-) dimensions of service quality for both parties. These aspects relates to the providing information for the patients, emotional support, involving patients into the treatment and having good medical equipment. Also, some important (sub-) dimensions were not stressed by both patients and providers, so we supplemented common (sub-) dimensions with these distinctive aspects. For example, providers mentioned professional skills dimension as the most essential aspect of healthcare service quality. In conclusion, we constructed one common perception of healthcare service quality consisting of common and distinct aspects of healthcare service quality. For the purpose of developing a combined quality management model we selected the most appropriate values, methodologies and tools from such quality management initiatives as TQM, Lean and Six Sigma. The selection was guided by dimensions from the common perception of healthcare service quality. The conducted study contributes to theoretical as well as practical areas. We believe that our research supplemented Quality Management theory by proposing beneficial combinations of TQM, Lean and Six Sigma and Service Quality literature by revealing additional aspects of service quality perception. Practical field will gain from the proposed flexible approach toward assembling quality management model.

Quality and quality management have gained importance in the construction industry also due to losses of life and property. For high-quality buildings, the amount of defects during the construction works must be reduced. Thus, it is important to determine the defects which lead to low quality in the construction projects / and architectural, structural and constructional standards to measure some indicators of quality like workmanship, design of components and usage of correct and highquality materials. Therefore a systematic approach is required to achieve good standards both in design and construction. CONQUAS quality assessment system and Six Sigma quality management system are systems that could provide this systematic approach. The objective of this research is to evaluate the quality in mass-housing projects via Six Sigma. Thus, level of construction quality of the three houses in ODT&Uuml / KENT housing units in Turkey were assessed through Six Sigma with the contribution of CONQUAS quality assessment system. CONQUAS was used for determination of standards, whilst Six Sigma was used for data analysis. After the evaluation of interviews with contractor, site-supervisor, occupants and visual observations, defects and their reasons were determined. Reasons of poor quality in ODT&Uuml / KENT housing units were listed as firstly poor workmanship, then improper or of poorquality material usage and lastly problems in design of detailing. Despite different construction dates of units studied, the results show that nothing was learned from the previous mistakes and same defects were repeated. This shows the importance of a system providing feedback and evaluation of quality level of a construction project and quality improvement efforts of the contractor, and measuring the progress over time like Six Sigma.

Significant advances in modern ac/ac power converter technologies and demands of industries have reached beyond standard ac/ac power converters with voltage-source inverters fed from diode rectifiers. Power electronics converters have been matured to stages toward compact realization, increased high-power handling capability, and improving utility interface. Modern ac/ac power converter topologies with various control strategies have been introduced for the further improvements, such as matrix converters, current-fed converters, PWM rectifiers, and active power filters. In this dissertation, several new converter topologies are proposed in conjunction with developed control schemes based on the modern ac/ac converters which enhance performance and solve the drawbacks of conventional converters. In this study, a new fault-tolerant PWM strategy is first proposed for matrix converters. The added fault-tolerant scheme would strengthen the matrix converter technology for aerospace and military applications. A modulation strategy is developed to reshape output currents for continuous operation, against fault occurrence in matrix converter drives. This study designs a hybrid, high-performance ac/ac power converter for high power applications, based on a high-power load commutated inverter and a mediumpower voltage source inverter. Natural commutation of the load commutated inverter is actively controlled by the voltage source inverter. In addition, the developed hybrid system ensures sinusoidal output current/voltage waveforms and fast dynamic response in high power areas. A new topology and control scheme for a six-step current source inverter is proposed. The proposed topology utilizes a small voltage source inverter, to turn off main thyristor switches, transfer reactive load energy, and limit peak voltages across loads. The proposed topology maximizes benefits of the constituent converters: highpower handling capability of large thyristor-based current source inverters as well as fast and easy control of small voltage source inverters. This study analyzes, compares, and evaluates two topologies for unity power factor and multiple ac/ac power conversions. Theoretical analyses and comparisons of the two topologies, grounded on mathematical approaches, are presented from the standpoint of converter kVA ratings, dc-link voltage requirements, switch ratings, semiconductor losses, and reactive component sizes. Analysis, simulation, and experimental results are detailed for each proposed topology.

Today’s fast-paced global economy has intensified the demand for manufacturing companies to make their products more quickly and with higher quality to meet heightened consumer expectations while reducing costs. This competitive environment requires small to medium enterprise’s (SMEs) to implement well-designed business processes and leverage information technology (IT), such as an Enterprise Resource Planning (ERP) system, within their facilities to become more agile, flexible, and integrated to meet changing market demands. Issues emerge when facility managers lack reliable data on performance and costs, which subsequently impairs even basic decisions for resource allocation or process improvement. Although the benefits of a successful ERP implementation in large firms are recognized, there is a general lack of empirical IT productivity literature focusing on SMEs. This research is expected to contribute to a framework for performance measurement, providing facility decision-makers with important metrics for analyzing their firm’s ability to improve upon competitive priorities. Employing the Delphi process, key performance indicators (KPIs) including time, speed, quality, and cost, and corresponding performance measurement metrics, investigations are conducted between traditional manufacturing processes in SMEs and processes enhanced through ERP adoption. In this longitudinal case study, significant improvements are observed in production operations relative to time following ERP implementation including a reduction in the defect rate, total manufacturing cost, and scrap rate along with increases in on-time delivery and flexibility.

Transformation is change—especially under challenging circumstances—that is significant, systematic, and sustained, resulting in high levels of achievement for all students in all settings (Caldwell, 2006). Urban education is the primary focus and target of the school reform movement. The No Child Left Behind Act (NCLB) includes explicit requirements to ensure that students served by Title I are given the same opportunity achieve to high standards and are held to the same high expectations as all other students in each state. Urban public school superintendents confront social and economic challenges unique to urban districts and are under pressure to meet NCLB’s accountability standards and mandated policies. This study started with a broad question about effective urban public school superintendent management concepts and strategies. The study was designed and conducted to (a) identify the prevailing management concepts and strategies initiated by the superintendent to attain organizational clarity and effectiveness in improving student performance; (b) examine the degree to which the superintendent’s leadership and management concepts and strategies were understood, supported, and embraced by key members of the organization; and (c) examine how the management concepts and strategies used by the superintendent align with a business management concept that may be useful to district leaders and administrators seeking a concept or strategy to sustain organizational change. This researcher used a single-case study to examine the management concepts and strategies used by an urban public school district superintendent. This study was conducted in the largest urban public school system in Texas. The superintendent, 6 members of the district’s leadership team, and five principals were interviewed and answered online questionnaires. A board member was also interviewed. Finally, student achievement data were examined. The study found the superintendent implemented management leadership concepts and strategies that prevailed over the social and economic barriers faced by urban students. Use of these strategies increased and sustained student performance. Despite limitations, this study opens opportunities for further research in management leadership. Opportunities include further research within this urban district, outside the school district, or on each management leadership concept or strategy identified in this study. / text