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Distribution channel strategies of Japanese machine tool builders馮偉興, Fung, Wai-hing, Anthony. January 1989 (has links)
published_or_final_version / Business Administration / Master / Master of Business Administration
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A study of tool life and machinability parameters in high speed milling of hardened die steelsNiu, Caotan., 牛草坛. January 2007 (has links)
published_or_final_version / abstract / Mechanical Engineering / Master / Master of Philosophy
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Chatter reduction through active vibration dampingGanguli, Abhijit 24 November 2005 (has links)
The aim of the thesis is to propose active damping as a potential control strategy for chatter instability in machine tools.
The regenerative process theory explains chatter as a closed loop interaction between the structural dynamics and the cutting process. This is considered to be the most dominant reason behind machine tool chatter although other instability causing mechanisms exist.
The stability lobe diagram provides a quantitative idea of the limits of stable machining in terms of two physical parameters: the width of contact between tool and the workpiece, called the width of cut and the speed of rotation of the spindle. It is found that the minimum value of the stability limit is proportional to the structural damping ratio for turning operations. This important finding provides the motivation of influencing the structural dynamics by active damping to enhance stability limits of a machining operation.
A direct implementation of active damping in an industrial environment may be difficult. So an intermediate step of testing the strategy in a laboratory setup, without conducting real cutting is proposed. Two mechatronic "Hardware in the Loop" simulators for chatter in turning and milling are presented, which simulate regenerative chatter experimentally without conducting real cutting tests. A simple cantilever beam, representing the MDOF dynamics of
the machine tool structure constitutes the basic hardware part and the cutting process is simulated in real time on a DSP board. The values of the cutting parameters such as spindle speed and the axial width of cut can be changed on the DSP board and the closed loop interaction between the structure and the cutting process can be led to instability.
The demonstrators are then used as test beds to investigate the efficiency of active damping, as a potential chatter stabilization strategy. Active damping is easy to implement, robust and does not require a very detailed model of the structure for proper functioning, provided a collocated sensor and actuator configuration is followed. The idea of active damping is currently being implemented in the industry in various metal cutting machines as part of the European Union funded SMARTOOL project (www.smartool.org), intended to propose smart chatter control technologies in machining operations.
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A logic language as a database utilityLucas, R. J. January 1986 (has links)
No description available.
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An open CNC interface for intelligent control of grindingStatham, Craig G. January 1999 (has links)
No description available.
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Composite cutting tip and materials for mining toolsLake, P. W. January 1986 (has links)
No description available.
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The development of a rock classification system for use with diamond toolsWright, D. N. January 1997 (has links)
No description available.
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The growth, structure and properties of sinter-necks in mixed ferrous powder systemsRhodes, Nigel Anthony January 1998 (has links)
No description available.
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The influence of peer coaching in stimulating educators' learning in the work place / Patricia Nomasonto SookaneSookane, Patricia Nomasonto January 2006 (has links)
The aims of this research were to describe the role that coaching plays in the development of educators and to make recommendations for the way in which schools can make use of coaching as an educator human resource development tool at the workplace. According to the findings from the literature review, coaching plays an important role in the success of novice educators. Educators who are coached typically develop a strong self-concept, become consistent in the implementation of policies and procedures, show a greater focus on the teaching and learning purpose within the classroom and display more confidence in themselves, which increases their personal ability and selfefficacy
to help and develop learners, and thereby increasing the learners' love for learning and academic achievement. Educators who display the personal traits mentioned in the above paragraph, according to the findings from the literature study, become effective and expert educators who have something to offer to the learners and are recognized as professionals in their field. Various researchers in the reviewed literature stress the need for coaching for its inherent potential of being a panacea for educator attrition and turnover which are always the result of job dissatisfaction. The qualitative research method in the form of focus group interviews was used to elicit primary empirical data from a population sample of eighteen educator participants who were all at post level one. This educator participant population sample was engaged by the researcher on a three-day coaching session in Outcomes-Based Education and Training as a new teaching and learning system in South Africa. After this three-day coaching session, the participants were interviewed to determine the role that coaching plays in the development of educators, with a view to making recommendations for the way in which schools can make use of coaching as an educator human resource development tool at the workplace. The results of the empirical research revealed that educator participants who formed the population sample of this research experienced the three-day coaching session which the researcher conducted as follows: developmental; providing support and guidance; leading to paradigm shifts; setting aside any power differences to offer a relaxed atmosphere; and eventful.
Recommendations for educational practice and further research were made. / Thesis (M.Ed.)--North-West University, Vaal Triangle Campus, 2006.
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Languages, Logics, Types and Tools for Concurrent System ModellingGutkovas, Ramūnas January 2016 (has links)
A concurrent system is a computer system with components that run in parallel and interact with each other. Such systems are ubiquitous and are notably responsible for supporting the infrastructure for transport, commerce and entertainment. They are very difficult to design and implement correctly: many different modeling languages and verification techniques have been devised to reason about them and verifying their correctness. However, existing languages and techniques can only express a limited range of systems and properties. In this dissertation, we address some of the shortcomings of established models and theories in four ways: by introducing a general modal logic, extending a modelling language with types and a more general operation, providing an automated tool support, and adapting an established behavioural type theory to specify and verify systems with unreliable communication. A modal logic for transition systems is a way of specifying properties of concurrent system abstractly. We have developed a modal logic for nominal transition systems. Such systems are common and include the pi-calculus and psi-calculi. The logic is adequate for many process calculi with regard to their behavioural equivalence even for those that no logic has been considered, for example, CCS, the pi-calculus, psi-calculi, the spi-calculus, and the fusion calculus. The psi-calculi framework is a parametric process calculi framework that subsumes many existing process calculi. We extend psi-calculi with a type system, called sorts, and a more general notion of pattern matching in an input process. This gives additional expressive power allowing us to capture directly even more process calculi than was previously possible. We have reestablished the main results of psi-calculi to show that the extensions are consistent. We have developed a tool that is based on the psi-calculi, called the psi-calculi workbench. It provides automation for executing the psi-calculi processes and generating a witness for a behavioural equivalence between processes. The tool can be used both as a library and as an interactive application. Lastly, we developed a process calculus for unreliable broadcast systems and equipped it with a binary session type system. The process calculus captures the operations of scatter and gather in wireless sensor and ad-hoc networks. The type system enjoys the usual property of subject reduction, meaning that well-typed processes reduce to well-typed processes. To cope with unreliability, we also introduce a notion of process recovery that does not involve communication. This is the first session type system for a model with unreliable communication.
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