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Optimizing printed circuit board assembly times on a high-speed pick-and-place machine.Weedmark, Mark Archie. January 1995 (has links)
In this thesis, we investigate the problem of minimizing printed circuit board assembly time on high-speed pick-and-place machines. As it is considered unlikely that efficient methods will be found for this problem, heuristic methods which give near optimal solutions are sought. Several such methods currently exist, but there are no comparisons made between the different methods. One of the reasons for this is the differences in the models used. In the thesis, we develop a more general model for the problem which encompasses most other models, and is robust, i.e. it can easily be adapted to different situations. We adapt two of the heuristic methods from the literature to this model, implement and test them and report the resulting assembly times. We also provide improvements to these methods, and improved lower bounding techniques for the problem. Finally, we adapt the best method to a real-world situation, namely the environment at the Mitel Corporation in Ottawa, Canada. We test this method against the sophisticated software tool currently being used at Mitel, with good results.
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SIMEX: A simulation-based expert production scheduling system.Coskun, Risvan. January 1995 (has links)
A good methodology for production scheduling can result in high efficiency in reducing manufacturing costs. SIMEX is an experimental simulation-based expert production scheduler developed by the author for applications in flexible flow shop systems in a dynamic factory environment. This study introduces the general framework of SIMEX. A prototype is developed on an IBM compatible PC in Prolog, MODSIM II, Visual Basic, and Visual C++ to generate feasible and acceptable schedules with a synchronous data exchange facility. In general, primary tasks of SIMEX are to meet due dates of the final products, to increase throughput by reducing the number of setups, and to reduce inventory cost in a flexible flow shop system in real time. SIMEX has also an ability to change its expert system's rule base interactively by means of a user interface. The expert system module of SIMEX allows to use heuristics, and production rules which are the simplifications that help limit the search for possible problem solutions and handling unexpected events. Simulation-based scheduler written in MODSIM II, is another module of SIMEX. It generates the schedules, repeatedly, to analyze and verify proposed design and alternatives. (Abstract shortened by UMI.)
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Towards an organizational planning system design: Implications for regional planning.Lemire, Jean-Marc. January 1978 (has links)
The purpose of the thesis is to explore the design of a planning system applicable to any formal organization. To do this, issues which are related to planning systems of various types (corporate, voluntary, public) are examined in chapter I. In order to take these issues into account, the chapters II and III indicate that the concepts of system and of design should be better understood. This provides tentative guidelines for the design of systems applicable to the management of organizations (chapter IV). These first four chapters make up the first part of the thesis and provide a review of some of the basic concepts which are needed to formulate a planning system of the type envisaged. The second part of the thesis essentially describes the various components of the planning system using the guidelines and concepts provided in the first part. In chapter V, an overview of the system is provided while chapters VI, VII and VIII focus on three aspects of the planning system. Chapter VI, 'Planning Operations,' essentially revises already provided steps of the planning process and chapter VII provides guidelines for 'planning authority and responsibilities' which do not appear to have been extensively discussed in previous literature on planning systems. As a conclusion, chapter VIII presents a series of implications of a general planning system for regional planning theory and practice.
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A study of the solubility of synthetic hydroxyapatite.Sleeman, Kenneth Jack January 1963 (has links)
study was made of the solubility of synthetic hydroxyapatite (Ca₁₀(PO₄)₆(OH₂). The basic calcium phosphate was synthesized in CO₂ free systems, over a pH range of 5.0 to 8.0 using reaction temperatures of 40°, 60°, and 90°C, and reaction periods of 24 and 96 hours. The study was divided into two phases. In one phase the pH of the suspensions, and the calcium and phosphorus concentrations in solution were measured after precipitation and after redispersing the preparations in water. The application of solubility criteria to these studies showed that the differences in solubility obtained by synthesis with varying reaction period and temperature were not brought about by conditions of super saturation. Solubility was found to decrease with increased synthesis reaction period and increased temperature of synthesis. With a given temperature and synthesis reaction period the hydroxyapatite preparations had a uniform solubility. Solubility changed only when the conditions of synthesis were changed. X-ray diffraction analysis of the solid phase indicated that the solubility of hydroxyapatite decreased with increasing crystallinity. Examination with the electron microscope, however, showed that increased crystallinity was not due to increasing crystal size. Owing to the smallness of crystals, it was not possible to examine the hydroxyapatite with a petrographic microscope, and hence it was not possible to detect the presence of amorphous phases. It is possible, then, that small amounts of amorphous substances were present in the solid phase, and, as a result the apparent degree of crystallinity was altered.
In the second phase, studies of the Ca:P mole ratios of the preparations showed that Mole ratios were not constant for any mode of synthesis. Further studies indicated that adsorption was of no, or at best, minor importance in determining the Ca:P ratios of hydroxyapatite. Isomorphous substitution with OH¯ions replacing PO₄¯ ions, and H₃O⁺ ions replacing Ca⁺⁺ ions might have occurred, but it was not possible to detect solubility differences which should result from this substitution. Hence it was not possible to correlate solubility with composition of hydroxyapatite. Even though the hydroxyapatite appeared to be of variable composition, it was found that this basic calcium phosphate had a definite pKsp value in the pH range of 5.0 to 8.0. / Land and Food Systems, Faculty of / Graduate
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Some aspects of the oceanographic structure in the Jervis Inlet systemLazier, John Robert Nicholas January 1963 (has links)
The variations in the distributions of temperature, salinity, and dissolved oxygen content in the water in the Jervis system of inlets, between July 1961 and March 1963, have been examined in order to ascertain net current patterns and interactions between the inlets. The depths of the entrance sills divide the inlets into two groups. Of the four inlets in the system three possess shallow sills which force the tide water to enter the inlets in a turbulent jet. The circulation pattern resulting from the influence of this jet on the inlet is proposed. In contrast, the sill of the largest inlet in the system (Jervis) is deep and the tidal flow does not destroy the vertical stratification in the inlet to any appreciable degree. The relatively small fresh water runoff into Jervis creates a weak estuarine circulation resulting in slow renewal of the intermediate and deep water. The low oxygen concentrations found at mid-depths near the head of Jervis are attributed to this abnormally slow renewal. A mid-depth oscillatory flow of unknown period was found during the winter of 1962-63 in Jervis Inlet. This flow is attributed to strong south-westerly winds which raise the water level in Jervis Inlet forcing a mid-depth outflow. The direction of this flow possesses a negative correlation with the depth of the surface layer. / Science, Faculty of / Physics and Astronomy, Department of / Graduate
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The relationship of brachial pulse wave measurements to the performance of cross country runnersYarr, Alan David January 1963 (has links)
The cardiovascular condition of five members of the University of B.C. cross country team was checked weekly with the Cameron Heartometer. Heartograph measures taken twenty-four hours before competition were compared to the coach's subjective appraisal of the athlete's performance to see if fluctuations in any of the measures corresponded to fluctuations in performance. A record of the runners' training load was also kept.
Using case study methods the information above was observed and studied to see if the heartometer is a practical device for anticipating staleness, incipient infection or general inability to adapt to the training load. The autonomic nervous tone of the athlete is indirectly represented by the heartometer measures. The measures of the heartograph were also statistically interpreted to see which measures showed significant trends during the nine weeks of testing.
Each of the five athletes showed results that were different than those of his teammates. One athlete, with a long history of endurance training, significantly improved most of the aspects of his cardiovascular condition in the short nine-week season. This runner ran well throughout the season with no apparent staleness. Another athlete, who has had severe attacks of asthma, performed well until attempting a particularly heavy amount of work. After this work he ran a very poor race. The heartograph showed a rest-to-work ratio that had dipped sharply from previous readings, on a graph taken twenty-four hours before this race. A third subject had been training all year. From the beginning of testing this runner showed strong pulse wave responses. However, his performance was not as would be expected from an athlete that was adapting well to his training. During the season the athlete had a slight nervous breakdown which indicates that he was not adapting to the stresses of his overall programme. With a reduction of training his running improved somewhat as did certain measures of his pulse wave. The fourth subject trained hard but did not perform as well as might be expected for an athlete undertaking this amount of training. The fifth man trained moderately throughout the season. This subject was basically a middle distance runner and participated in cross country in preparation for the track season. His heartograph measures showed gradual improvements and three - systolic blood pressure, pulse pressure and rest-to-work ratio - showed significant linear increase during the training period. This runner performed as expected in all races.
Four measures of the pulse wave showed parallel development with improving cardiovascular condition; these were the diastolic surge, rest-to-work ratio, systolic blood pressure and pulse pressure. The rest-to-work ratio showed variations that on observation best indicated staleness or inability to adapt to the training load. / Education, Faculty of / Curriculum and Pedagogy (EDCP), Department of / Graduate
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A study of rhabdomyosarcomas induced by nickel sulphide in rats.Capstick, Valerie January 1963 (has links)
The study of rhabdomyosarcomas induced by nickel sulphide was undertaken in order to investigate their growth and responsiveness characteristics and to evaluate their possible usefulness as experimental tumour systems. A study was also made on the carcinogenic specificity of nickel sulphide.
Intramuscular injections of 0.5 to 20 mg. of Ni₃S₂ resulted in tumours after two to six months, which grew fairly rapidly, once palpable. On transplantation they proved to be highly malignant, causing 100 per cent takes within approximately two weeks and death of the host within three to eight weeks. Detailed histological study was performed on many sections of tumour and muscle in order to establish identity of the rhabdomyosarcomas and to observe such cytological phenomena as muscle degeneration, tissue disruption and development of anaplasia.
The carcinogenic activity of Ni₃S₂ was emphasized by the rapidity of tumour induction observed after very low doses, while the difference in latent periods suggested some correlation between dose and response. Injections of Ni₃S₂ into body organs illustrated the extreme toxicity of the substance in individual tissues. Although results were somewhat inconclusive within the time limit of the experiment, the general tenor of the data suggested that Ni₃S₂ had a toxic rather than tumourigenic action on most tissues. The appearance of rhabdomyosarcomas when the compound was in contact with abdominal or leg musculature gave evidence that nickel sulphide might have some specificity for striated muscle. Preliminary experiments with NiS indicated that its carcinogenicity, if any, was considerably less than that of Ni₃S₂, with different solubility in muscle being a possible explanation.
Several of the induced tumours were used for metabolic and experimental therapy studies with various compounds. Numerous experiments indicated that the tumour was essentially unreliable for such studies since growth rates and response were not reproducible in different tumour generations. However, some general trends were noted. Response to the corticoids ranged from residual to complete inhibition of many tumours during the period of treatment with Cortisol or cortisone. Subcutaneous injections of testosterone showed acceleration of growth in some tumour lines. Tests with the Vinca alkaloids suggested some correlation with clinical anti-tumour effects, indicating an increased effectiveness of both Vinblastine and Vincristine when administered during the first week after transplantation. / Medicine, Faculty of / Cellular and Physiological Sciences, Department of / Graduate
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Studies of dispersion-hardening parametersArmstrong, John Torrance January 1963 (has links)
Experiments were carried out with 1 micron copper powder compacts containing up to 7.5 vol % .018 micron alumina, and with various types of lead powder compacts containing up to 20 vol % of various other materials.
The results indicate that dispersion-hardened alloys should be divided into three groups on the basis of the nature of the second phase.
i) particulate, adherent (not coherent) with matrix
ii) particulate, non-adherent with matrix
iii) semi-continuous
It is suggested that the room temperature strengthening of the second and third groups of alloys may be due primarily to a grain size effect as described by the Hall-Petch relationship.
The cell-like structure recently proposed for S.A.P. has been observed in the lead-lead oxide system by electron microscopy.
An explanation of the difference in properties between extruded and rolled dispersion-hardened alloys has been offered in terms of the directional deformation caused by rolling. / Applied Science, Faculty of / Materials Engineering, Department of / Graduate
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Anxiety and masculinity-femininityPruesse, Manfred Gebhard January 1962 (has links)
The primary purpose of the study was to investigate the relationship between anxiety and masculinity-femininity in order to clarify some of the causes of the sex differences found in anxiety. A secondary purpose was to investigate the overt and covert aspects of anxiety in feminine males and masculine females. The sample was composed of 33 male and 38 female university students enrolled in a second year summer school course in psychology. The IPAT Anxiety Scale and the MMPI Mf Scale were administered, in that order, during a regular classroom period. The relationship between the two sets of scores was examined. The 15 most feminine males and the 15 most masculine males were compared with respect to their overt and covert anxiety scores. The same was done with the female subjects.
A correlation of 0.26, significant at the 0.01% level, was obtained between the anxiety scores and the Mf scores. Feminine males were overtly and covertly significantly more anxious than masculine males. Feminine females were overtly significantly more anxious than masculine females. However, feminine and masculine females scored approximately equally on the covert anxiety scale.
It was concluded that anxiety is associated with femininity. The suggestion was made that it may be some aspect of the female sex role, as delineated by society, that accounts for the higher anxiety in feminine people. / Arts, Faculty of / Psychology, Department of / Graduate
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Some oceanographic features of the Northeast Pacific ocean during August 1955.Bennett, Edward Bertram January 1958 (has links)
Physical oceanographic data from the international NorPac survey of August 1955, in the area north of Latitude 45° N and east of Longitude 161° W, were examined. The temperature, salinity, and density distribution and structure from the surface to 2000 meters are discussed.
The temperature structure showed an isothermal layer to about 30 meters depth, a marked thermocline to about 100 meters depth, a temperature inversion in most of the area, and below this a gradual temperature decrease into the abyss. At all depths the water was coldest in a "cold core" centered about 100 miles south of Kodiak and the Shumagin Islands. From there the temperature increased at each level in all directions.
The salinity structure showed an isohaline layer to about 100 meters depth, a marked halocline to about 200 meters depth, and below this the salinity increased slightly into the abyss. The salinity structure did not coincide with the temperature structure.
The density structure showed an isopycnal layer to about 30 meters depth, a pycnocline associated with the thermocline, a second isopycnal layer, a second pycnocline associated with the halocline, and below this the density increased slightly into the abyss.
Variations in these structures throughout the region are discussed in some detail.
There is no horizontal isosteric level in the 2000 meters of depth. It is concluded that there is no level of "no net motion" in this range, but a reference level of 2000 decibars for dynamic calculations is more acceptable than the usual 1000 decibar level. A new procedure is introduced to extend the reference level into the bottom in near coastal areas.
The geostrophic currents were calculated. There was a major latitudinal drift from the west into the central part of the area. It veered northward and continued around the Gulf of Alaska, forming the Alaska Gyral, and left the area to the westward, as an intensified current (Alaska Stream) close along the Alaskan Peninsula. This intensification is probably due to conservation of absolute vorticity through changing latitude.
The circulation pattern extended to at least 2000 meters depth, and probably to the bottom. It transported about 17 milion cubic meters of water per second. There were a number of eddies in the system, some of which were observed on earlier surveys.
The major flow pattern was not wind-generated within the region. The influence of local winds was limited to the upper 200 meters of depth. In some areas it aided the flow, and in others retarded it.
There is evidence to show that two chains of sea mounts influenced the current pattern according to the Bjerknes concept. Since the major portion of these is below 2000 meters depth it is concluded that currents exist in the abyss, in essentially the same direction as at the upper levels. This is consistent with the concept of conservation of absolute vorticity with changing latitude. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate
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