Title: Distinguished elements of group rings Author: Bc. Zuzana Procházková Department: Department of Algebra Supervisor: doc. Mgr. et Mgr. Jan Žemlička, Ph.D., Department of Algebra Abstract: This thesis is about finding idempotents in a group ring. We describe three techniques of finding idempotents in a semisimple group ring and in the last chapter there is an attempt to find idempotents in a group ring that does not have to be semisimple. The first technique uses representations and characters of a group. The second technique finds idempotents through the use of Shoda pairs. The third technique lifts idempotent from the factor ring with the help of CNC system of ideals, which is a generalization of a well-known technique with nilpotent ideals, and it is here extended to group rings formed by non-abelian group and noncommutative ring. iii

This research seeks to adopt a post-foundationalist practical theology paradigm, as discussed by J C Müller, in order to create a bridge between the three concepts of the pastoral care perspective, the narrative perspective based on social-constructionism and post-foundationalism. Furthermore, I made use of Müller’s seven movements of methodology which laid a strong foundation to base my research on regarding married migrant women living within Korean multicultural families. Korean society which is a homogeneous culture is currently facing many challenges as a result of becoming more and more multicultural. These multicultural issues are becoming major social and political issues in South Korea. The main reason that South Korean society has become more multicultural is because of intercultural marriages which have also resulted in an increase in multicultural families. These migrant women are faced with many kinds of discrimination and prejudice as a result of their different appearance, culture and language. Furthermore, Korean culture often deprives women of having any position above men especially once they are married. After being married a woman should become invisible, voiceless, and nameless in order to become culturally acceptable. This often results in a migrant woman feeling stressed, fearful, isolated and alone which often results in the development of a low self-esteem, a lack of self-confidence and a low self-image. In my research, I sought to listen to and identify the stories of migrant women, namely foreign women who have married Korean men with a focus on the impact on their identities within a Korean multicultural family through a narrative perspective in order to have a positive growth and outcome from their intercultural differences within South Korea. I decided to view my co-researchers not as co-researchers but as companions on a journey which we could undertake together. The use of the metaphors ‘journey’ and ‘companions’ seemed to give my companions the freedom to speak more openly and placed us on an equal level. Furthermore, I not only discovered my companions’ identities through their own stories, but also developed my companions’ true identities/multi-identities through the broader, inter-relational stories of other people within multicultural communities through a six step process of Listening to the voice, Gaining voice, Giving voice, Finding alternative voice, Retelling voice and Creating future voice. I made use of the narrative approach in order to listen to my companions so that a unity would exist between their past, present and future stories. As I listened to the stories of my companions from a narrative perspective new possibilities were opened which lead to alternative and future stories. Furthermore, my companions were given the opportunity to find themselves and make new identities on the real journey of life. Through the process of my research I also developed a multicultural identity model specifically for married migrant women in South Korea, but ultimately the purpose of my research was not to show or develop a multicultural identity model regarding migrant women, but was more to help these migrant women find their identities themselves and in this become self-empowered to become contributors to Korean society. / Thesis (PhD)--University of Pretoria, 2014. / gm2014 / Practical Theology / unrestricted

Thesis solves an issue of application unconventional materials used in horizontal boring machine design. Chosen problem is solved step by step from general selection of suitable material for supporting structure. The selected material is applicated on WFT 13 CNC machine design from production of Fermat and it is created 9 conceptual options of machine’s frame. Finite element method is used for analysis of conceptual options. Based on data from analyses, the best option is selected for constructional part with use of multi-criteria PATTERN method. Constructional part of thesis elaborates on the design of selected conceptual option and gives recommendation for essential processes used in development and production of sandwich structures. The master’s thesis comes with new construction solution for supporting structure of selected machine and especially insight in development and production of new unconventional materials in horizontal boring machines design.

The diploma’s thesis deals with the current state of requirements for products resulting from directives of the European Parliament and the European Council. The aim of the thesis is a system analysis of the issue, proposal and justification of the chosen procedure for solving the objectives. Furthermore, the analysis of requirements of current standards and safety analysis related to the work of machine operators in the areas of operation, service and maintenance of horizontal boring machine WHN 13 CNC. The analysis is followed by a proposal for preventive measures for hazards where the value of risks and criticality is unacceptable, leading to their reduction.

Direct Machining And Control (DMAC) is a new method of controlling machine tools directly from process planning software. A motion planning module is developed for the DMAC system that operates directly off path geometry without pre-tessellation. The motion planner is developed with the intent to process Bezier curves. The motion planning module includes a deterministic predictor-corrector-type curve interpolator, a dynamics limiting module, and a two-pass jerk-limited speed profiling algorithm. The methods are verified by machining an automotive surface in a clay medium and evaluating the resultant machine dynamics, feed rate, and chordal error throughout the machining process.

В данной магистерской диссертации представлены результаты разработки методов повышения точности преобразователей вращательного движения в поступательное для систем отсчета перемещения рабочих органов станков с ЧПУ, что и является целью выпускной квалификационной работы. Актуальность темы обусловлена тем, что точность машин и механизмов является основной характеристикой их качества. Традиционные механические передачи (зубчатые, реечные и др.) имеют широкое применение во всех отраслях машиностроения. Требования к точности изготавливаемых деталей существенно ужесточаются, поэтому необходимо непрерывно совершенствовать методы повышения точности передач. Научная новизна обусловлена разработкой новых методов повышения точности систем отсчета перемещений путем уменьшения или ликвидирования кинематических погрешностей и погрешностей от износа преобразователей вращательного движения в поступательное. Рассмотрены элементы, применяемые при построении современных систем отсчета перемещений и возникающие в них погрешности. Проведен анализ существующих методов уменьшения кинематических погрешностей и погрешностей от износа преобразователей вращательного движения в поступательное. На его основе разработаны: метод отсчета перемещений рабочего органа станка с компенсацией погрешностей ходового винта; метод снижения износа передачи винт-гайка скольжения; метод снижения износа передачи винт-гайка качения; метод отсчета перемещений рабочего органа станка с коррекцией кинематических погрешностей рейки; метод снижения износа зубчато-реечной передачи; насос, предназначенный для использования при реализации перечисленных методов. В ходе работы над магистерской диссертацией было подано шесть заявок на изобретения. В результате было получено пять патентов: патент на изобретение №2750575 «Насос шестеренный реверсивный», патент на изобретение №2756797 «Передача винт-гайка качения», патент на изобретение №2764105 «Зубчато-реечный привод подачи металлорежущего станка с ЧПУ», патент на изобретение №2768807 «Устройство отсчета перемещений рабочего органа машины с ходовым винтом» и патент на изобретение №2767381 «Передача винт гайка скольжения». На рассмотрении в ФИПС находится заявка на изобретение №2021114570 «Зубчато-реечный привод подачи рабочего органа тяжелого крупногабаритного металлорежущего станка». / This master's thesis presents the results of the development of methods for precision improvement of reference systems for the movement of movable operating element of CNC machines, which is the purpose of the final qualifying work. The relevance of the topic is due to the fact that the precision of machines and mechanisms is the main characteristic of their quality. Traditional mechanical gears (gear, rack and pinion, etc.) are widely used in all branches of mechanical engineering. The requirements for the precision of manufactured parts are significantly tightened, so it is necessary to continuously improve methods for improving the precision of transmissions. The scientific novelty is due to the development of new methods for improving the precision of displacement reference systems by reducing or eliminating kinematic errors and errors from wear of rotary motion converters to translational. The elements used in the construction of modern displacement reference systems and the errors arising in them are considered. The analysis of existing methods for reducing kinematic errors and errors from wear of rotary motion converters to translational motion is carried out. Based on it, the following methods have been developed: the method of counting the movements of the movement of movable operating element of the machine with compensation of errors of the lead screw; the method of reducing the wear of the transmission screw-nut sliding; the method of reducing the wear of the rolling screw-nut transmission; the method of counting the movements of the movement of movable operating element of the machine with correction of kinematic errors of the rail; the method of reducing the wear of rack and pinion transmission; the pump, designed for use in the implementation of the above-mentioned methods. During the work on the master's thesis, six applications for inventions were submitted. As a result, five patents were obtained: patent for invention No. 2750575 "Reversible gear pump", patent for invention No. 2756797 "Rolling screw-nut transmission", patent for invention No. 2764105 "Rack-and-pinion feeding drive of CNC metal cutting machine", patent for invention No. 2768807 "Device for counting the movements of the operating member of a machine with a drive screw" and patent for invention No. 2767381 "Sliding screw-nut gearing". The application for invention No. 2021114570 "Rack-and-pinion feeding drive of the operating member of a heavy large-sized metal-cutting machine" is under consideration in the federal institute of industrial property.

Early in the ship design process, naval architects must often evaluate and compare multiple hull forms for a specific set of requirements. Analytical tools are useful for quick comparisons, but they usually specialize in a specific hull type and are therefore not adequate for comparing dissimilar hull types. Scale model hydrodynamic testing is the traditional evaluation method, and is applicable to most hull forms. Scale model tests are usually performed on the largest model possible in order to achieve the most accurate performance predictions. However, such testing is very resource intensive, and is therefore not a cost effective method of evaluating multiple hull forms. This thesis explores the testing of small scale models. It is hypothesized that although the data acquired by these tests will not be accurate enough for performance predictions, they will be accurate enough to rank the performance of the multiple hull forms being evaluated.

本研究針對台灣工具機產業廠商，探索其研發專案知識管理對新產品開發績效的影響，及其技術知識特質對知識管理的關聯性。本論文以深入個案訪談法為主要的研究方法，訪談國內具代表地位的二家工具機業大廠之設計及開發部門，並自其中各選擇二個研發專案作為研究對象。 　　本研究歸納分析所得到的研究發現如下： 　　【研究發現一】研發專案知識吸收來源愈多、範圍愈廣、組織學習活動愈多，其新產品開發績效愈高。 　　【研究發現二】研發專案知識創造技術突破愈多、創新價值愈高，其新產品開發績效愈高。 　　【研究發現三】研發專案知識蓄積文件化程度愈高、蓄積活動愈多、累積專案核心能耐愈多，其新產品開發績效愈高。 　　【研究發現四】研發專案知識擴散方式愈多、擴散活動愈多，其新產品開發績效愈高。 　　【研究發現五】技術知識變動程度對研發專案的知識管理有明顯的影響。 　　【研究發現六】技術知識外顯程度對研發專案的知識管理有明顯的影響。 　　【研究發現七】技術知識路徑相依度對研發專案知識管理的影響，似乎不是很明顯。 　　【研究發現八】技術知識模組化程度對研發專案知識管理的影響，似乎不是很明顯。 　　【研究發現九】技術知識複雜化程度對研發專案的知識管理有明顯的影響。 　　因此，本研究建議企業為了提升新產品開發的成效，的確需要強化知識管理，同時其研發部門應設計符合技術知識特質及利於推動知識管理的組織型態與作為。平時應作好內部技術傳承及外部技術來源佈置工作，並在新產品開發不同階段妥善配置適合的資源與人力。 / This research is focused on Taiwan's CNC machine industries for exploring the impacts of knowledge management on the performance of new product development. The influence of the characteristics of technological knowledge on knowledge management is also studied. The research was conducted mainly based on deep case studied. The research subjects include four R&D projects two which are selected from two companies of CNC machine industry. 　　The preliminary conclusions are as follows: 　　1. The more the R&D project knowledge is absorbed from different sources, wide ranges,and multiple organizational learning activities, the better the performance of new product development would be. 　　2. The more the R&D project knowledge creates the technological breakthrough and thenewly added value, the better the performance of new product development would be. 　　3. The more the R&D project knowledge is accumulated with the documentation, the amass of activities, and the core resourcefulness, the better the performance of new product development would be. 　　4. The more the R&D project knowledge is diffused in different patterns and activities, the better the performance of new product development would be. 　　5. There exists a direct relationship between the knowledge management of R&D project and the degree of change of technological knowledge. 　　6. There exists a direct relationship between the knowledge management of R&D project and the degree of explicitness of technological knowledge. 　　7. There doesn't exist a direct relationship between the knowledge management of R&D project and the degree of path dependence of technological knowledge path. 　　8. There doesn't exist a direct relationship between the knowledge management of R&D project and the degree of modualization of technological knowledge. 　　9. There exists a direct relationship between the knowledge management of R&D projects and the degree of complexity of technological knowledge. 　　As a result, it is suggested that the R & D departments of the companies possessed with different characteristics of technological knowledge should design the organizational form and activities that are conformed to the characteristics of technological knowledge for facilitating the practices of knowledge management. 　　The internal technology inheritance and the external technology resource deployment have to be executed ordinarily; and the appropriate resources as well as human powershall be properly allocated in accordance with the different steps of new product development with a view to intensifying the satisfactory result.

This master‘s thesis is presenting the way of the optimization of grinding characteristics when grinding cemented carbides by diamond wheels. There is described the theory of grinding, including grinding wheels and basic characteristics of cemented carbides in the theoretical part. There are defined experimental metering accomplished on the CNC grinding machine Walter Helitronic Power Mini in the practical part. There were tested eight grinding wheels. The grinding rate, surface roughness Ra, theoretic guaranteed storage period of grinding wheel in number of cuts, theoretical capacity of machined material, achievement of grinding machine and behaviour of the wheels when grinding ware evaluated from the reached results.

Dans cette thèse, des particules de polymère fonctionnalisées en surface avec des groupes poly (éthylène glycol) (PEG) ont été synthétisées pour favoriser leur interaction avec les dérivés cellulosique via liaisons hydrogène intermoléculaires. Deux voies de synthèse ont été proposées pour obtenir ses composites cellulose/latex.La première voie est basée sur l'auto-assemblage induit par polymérisation (PISA) pour former des nanoparticules fonctionnalisées avant leur adsorption sur un substrat cellulosique. La PISA tire profit de la formation de copolymères blocs amphiphiles dans l'eau en combinant la polymérisation en émulsion avec les techniques de polymérisation radicalaire contrôlées (RDRP). Ces dernières sont utilisées pour synthétiser des polymères hydrophiles agissant à la fois comme précurseur pour la polymerization en émulsion d'un monomère hydrophobe, et comme stabilisant des particules de latex obtenues. Deux techniques de RDRP ont été étudiées : les polymérisations RAFT et SET-LRP. Des polymères hydrophiles à base de PEG de faible masse molaire ont été synthétisés en utilisant ses deux techniques qui sont ensuite utilisés pour la polymérisation d'un bloc hydrophobe dans l'eau. Le transfert de l'agent de contrôle au site de la polymérisation était difficile en utilisant la SET-LRP en émulsion, conduisant à la formation de larges particules. En utilisant la RAFT en émulsion, des particules nanométriques ont été obtenues, avec un changement morphologique observé en fonction de la taille du segment hydrophobe, puis adsorbées sur des nanofibrilles de cellulose (CNF).La seconde voie utilise la polymérisation en émulsion classique réalisée en présence de nanocristaux de cellulose (CNC) conduisant à une stabilisation Pickering des particules de polymère. L'interaction cellulose/particule est assurée grâce à l'ajout d’un comonomère à type PEG. Une organisation a été visualisé dans laquelle plusieurs particules de polymère recouvrent chaque CNC / In this thesis, polymer particles surface-functionalized with poly(ethylene glycol) (PEG) groups were synthesized to promote their interaction with cellulose derivatives via intermolecular hydrogen bond. Two synthetic routes were proposed to obtain such cellulose/latex composites.The first route was based on the polymerization-induced self-assembly (PISA) to form functionalized polymer nanoparticles prior to adsorption onto cellulosic substrate. PISA takes advantage of the formation of amphiphilic block copolymers in water by combining emulsion polymerization with reversible-deactivation radical polymerization (RDRP) techniques. The latter were used to synthesize well-controlled hydrophilic polymer chains, acting as both precursor for the emulsion polymerization of a hydrophobic monomer, and stabilizer of the final latex particles. Two RDRP techniques were investigated: reversible addition-fragmentation chain transfer (RAFT), and single electron transfer-living radical polymerization (SET-LRP). Low molar mass PEG-based hydrophilic polymers have been synthesized using both techniques, used for the polymerization of a hydrophobic block in water. The transfer of controlling agent at the locus of the polymerization was challenging for SET-LRP in emulsion conditions leading to surfactant-free large particles. Nanometric latex particles were obtained via RAFT-mediated emulsion polymerization, with morphology change from sphere to fibers observed depending on the size of the hydrophobic segment, which were then able to be adsorbed onto cellulose nanofibrils (CNFs).The second route used conventional emulsion polymerization performed directly in presence of cellulose nanocrystals (CNCs) leading to Pickering-type stabilization of the polymer particles. Cellulose/particle interaction was provided thanks to the addition of PEG-based comonomer. Original organization emerged where CNCs were covered by several polymer particles