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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

A methodology for assessing the metropolitan locational flexibility of offices

Sikstrom, Brian Murray January 1978 (has links)
The initial premise of the thesis is that the question of metropolitan locational flexibility of offices — or the capability of offices to decentralize activities outside downtown but within the same metropolitan area — needs to be investigated and objectively assessed. It is apparent from the review of the literature no approach or method so far employed to assess office locational flexibility is suitable for use by the researcher and probably for Canadian urban planners and office location decision-makers. The thesis concentrates, therefore, on development and testing on federal government offices in Vancouver of a new method for assessment of metropolitan office locational flexibility. From the literature review ten inter-related factors and their possible influences on office locational flexibility are identified and form a framework or "Criteria Check List" for examination and evaluation of office locational flexibility. In the Criteria Check List methodology analysis of all ten factors and their locational flexibility influences on federal government offices is undertaken in three stages. The first stage, a quantitative and qualitative analysis of six "internal" factors (nature of activity/work; frequency, character and pattern of contacts; prestige; office establishment size and organizational structure; rate of growth and organizational change; tradition) is based on existing information collected for each of 15 sample federal departments. "Working Departmental Composite Sheets", "Indicators", and a point and weighting system are the major tools developed by the researcher to obtain a comparative evaluation of sample federal departments. Federal departments are classified as "most locationally flexible", "locationally flexible", "locationally inflexible" and "most locationally inflexible". In the second stage, information gleaned largely from library research on the four "external" factors ("general" and "special" physical accessibility downtown; metropolitan telecommunications and transportation systems; metropolitan Vancouver office market; planning and politics) is examined qualitatively and a synopsis of the "climate" for federal office locational flexibility in Vancouver presented. The third stage of the analysis is a synthesis of the findings from the two previous stages. The thesis presents conclusions about the methodology and conclusions derived from specific findings on federal office locational flexibility resulting from the testing of the methodology. The chief conclusion, with respect to the latter, is that federal offices have considerable metropolitan office locational flexibility but that prestige; tradition; "general" and "special" accessibility; and the metropolitan office market are prominent factors to be overcome if federal offices are to be relocated in Regional Town Centres. Of the fifteen federal departments examined office locational flexibility is found to be greatest for Supply and Services; Transport; Public Works; Energy, Mines and Resources; Unemployment Insurance; Manpower and Immigration; and Fisheries and Environment departments. The major methodological conclusion is that the Criteria Check List provides a much needed framework for clear thinking on, and examination of, the broad range of inter-related factors which affect office locational flexibility. Its use in the process of office location decision-making and/or planning could provide a rational basis with which perceived locational needs and preferences of offices could be called into question. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate
22

Algorithmic Approaches for Solving the Euclidean Distance Location and Location-Allocation Problems

Al-Loughani, Intesar Mansour 06 August 1997 (has links)
This dissertation is concerned with the development of algorithmic approaches for solving the minisum location and location-allocation problems in which the Euclidean metric is used to measure distances. To overcome the nondifferentiability difficulty associated with the Euclidean norm function, specialized solution procedures are developed for both the location and the location-allocation problems. For the multifacility location problem (EMFLP), two equivalent convex differentiable reformulations are proposed. The first of these is formulated directly in the primal space, and relationships between its Karush-Kuhn-Tucker (KKT) conditions and the necessary and sufficient optimality conditions for EMFLP are established in order to explore the use of standard convex differentiable nonlinear programming algorithms that are guaranteed to converge to KKT solutions. The second equivalent differentiable formulation is derived via a Lagrangian dual approach based on the optimum of a linear function over a unit ball (circle). For this dual approach, which recovers Francis and Cabot's (1972) dual problem, we also characterize the recovery of primal location decisions, hence settling an issue that has remained open since 1972. In another approach for solving EMFLP, conjugate or deflected subgradient based algorithms along with suitable line-search strategies are proposed. The subgradient deflection method considered is the Average Direction Strategy (ADS) imbedded within the Variable Target Value Method (VTVM). The generation of two types of subgradients that are employed in conjunction with ADS are investigated. The first type is a simple valid subgradient that assigns zero components corresponding to the nondifferentiable terms in the objective function. The second type expends more effort to derive a low-norm member of the subdifferential in order to enhance the prospect of obtaining a descent direction. Furthermore, a Newton-based line-search is also designed and implemented in order to enhance the convergence behavior of the developed algorithm. Various combinations of the above strategies are composed and evaluated on a set of test problems. Computational results for all the proposed algorithmic approaches are presented, using a set of test problems that include some standard problems from the literature. These results exhibit the relative advantages of employing the new proposed procedures. Finally, we study the capacitated Euclidean distance location-allocation problem. There exists no global optimization algorithm that has been developed and tested for this class of problems, aside from a total enumeration approach. We develop a branch-and-bound algorithm that implicitly/partially enumerates the vertices of the feasible region of the transportation constraints in order to determine a global optimum for this nonconvex problem. For deriving lower bounds on node subproblems, a specialized variant of the Reformulation-Linearization Technique (RLT) is suitably designed which transforms the representation of this nonconvex problem from the original defining space into a higher dimensional space associated with a lower bounding (largely linear) convex program. The maximum of the RLT relaxation based lower bound that is obtained via a deflected subgradient strategy applied to a Lagrangian dual formulation of this problem, and another readily computed lower bound in the projected location space is considered at each node of the branch-and-bound tree for fathoming purposes. In addition, certain cut-set inequalities in the allocation space, and objective function based cuts in the location space are generated to further tighten the lower bounding relaxation. Computational experience is provided on a set of randomly generated test problems to investigate both the RLT-based and the projected location- space lower bounding schemes. The results indicate that the proposed global optimization approach for this class of problem offers a promising viable solution procedure. In fact, for two instances available available in the in the literature, we report significantly improved solutions. The dissertation concludes with recommendations for further research for this challenging class of problems. Data for the collection of test problems is provided in the Appendix to facilitate further testing in this area. / Ph. D.
23

Semi and non economic factors in the formation, relocation and transfer of manufacturing plants in the north west region of England 1972-1975

McLoughlin, P. J. January 1982 (has links)
No description available.
24

New chelates for protein radiolabelling

Smith, Raymond John January 1993 (has links)
No description available.
25

Vision and proprioception in lower limb interceptive actions

Weigelt, Cornelia January 2000 (has links)
No description available.
26

Disaggregate behavioural airport choice models

Benchemam, Messaoud January 1986 (has links)
The identification of the distribution of air passengers among airports is an important task of the airport planner. It would be useful to understand how trip makers choose among competing airports. The ultimate purpose of this study is to research into , passengers' choice of airport so that the airport system can be planned on a more reliable basis. The choice of airport of passengers originating from central England in 1975 is explained by constructing multinomial disaggregate behavioural models of logit form. The data used for model calibration, were collected during two Civil Aviation Authority surveys. This work makes contribution to: -The definition of the major determinants of airport choice, -The responsiveness of passengers, choice to changes in these determinants, - The policy implications for the regional airports - The transferability of the model in time and space. The method of analysis has been selected after outlining the potential advantages and shortcomings of logit and probit models and after a test on the validity of the Independence from Irrelevant Alternatives (I.I.A.) property has been carried out. The results show that the multinomial logit model used for the airport choice is good in terms of its explanatory ability and successful in predicting the choices actually made. Travel time to the airport, frequency of flights and air fare are found to be decisive factors for a passenger to select a given airport but are not of equal importance. By influencing-these factors, it appears that there exists room for the transport planner to shift traffic from one airport to another to have an economically and/or environmentally efficient airport system. In their original form, the models have been tested and found not to be transferable to the London area in 1978. However, after a Bayesian updating procedure was applied, the business and inclusive tours models were transferable. The leisure model was not statistically transferable but had a good predictive ability while the domestic model was not transferable. Finally, subsequent directions ·for further research are outlined.
27

An empirical study of innovation, entry and diffusion in industrial clusters

Baptista, Rui Miguel Loureiro Nobre January 1996 (has links)
No description available.
28

A secure user authentication scheme for critical mobile applications

Ben Tahayekt Ben Tahaikt, Chaimaa January 2017 (has links)
Smartphones have facilitated tasks in private and work life for its users. In business, employees often should manage sensitive data that unauthorised people cannot access, so some user authentication is needed to perform. Besides the normal user authentication, some employers give the right to access to the sensitive data only if the employees stay in specific locations. That makes sense for those businesses that have various construction sites and offices that are not necessarily located in the same geographical region. In those companies, the employees must be able to perform their tasks from different locations regardless of the available network infrastructure. To protect the data from intruders, this research presents a secure location-based user authentication scheme for mobile application that works offline. This research considers to enable access to the sensitive data using off-the-shelf mobile devices without adding any extra hardware and with no additional information from a fixed infrastructure. This Thesis firstly describes the architecture and attributes of the proposed solution. Then, the techniques used for the design and functionality of the solution are presented. The results of this study reveal that the proposed solution is more suitable for the applications that is used in outdoor locations. Finally, to alleviate the shortcoming of the presented technique for indoor locations, a new method has been discussed and tested. This report is a final Thesis in collaboration with SAAB. The purpose of this research is to examine the best way to protect sensitive data managed by the employees using their smartphones in different workplaces.
29

The effect of postmortem aging and location on tenderness of steaks from beef Semitendinosus and Longissimus lumborum

Matney, MaryAnn Joy January 1900 (has links)
Master of Science / Department of Animal Sciences and Industry / Terry A. Houser / The objective of this study was to determine the effect of extended postmortem aging (DOA), steak location (LOC), and dietary treatment (TRT) on cooked meat tenderness, sarcomere length, and myofibrillar protein degradation of steaks from the Semitendinosus (ST) and Longissimus lumborum (LL). Crossbred feedlot steers (n = 40; initial body weight 638 ± 29 kg) were fed 45 d with the following diets: a control diet, control diet with microalgae meal, microalgae meal and antioxidants fed at the beginning of feeding, and microalgae meal with antioxidants fed during the final 10 d of feeding. The ST and LL were removed from carcasses. The ST was fabricated into 10 steaks, which were paired with an adjacent steak and assigned 5 LOC; LOC 1 was the most proximal and LOC 5 was the most distal. Each LOC was randomly assigned an aging period of 7, 14, 28, 56 or 112 d. The 6 most posterior steaks of the LL were paired with an adjacent steak and assigned 3 locations; LOC 1 being the most anterior and LOC 3 the most posterior. Each LOC of the LL was randomly assigned an aging period of 7, 28, or 112 d. Shear force, sarcomere length, muscle fiber type and size, postmortem proteolysis, and calpain activity were measured across aging periods for each LOC. Improved Warner-Bratzler shear force (WBSF) values were detected throughout the 112 d aging period for both ST and LL steaks (quadratic; P < 0.01). The largest decrease in shear force occurred between d 7 and 28 for LL and ST steaks. Shear force decreased (P < 0.01) from LOC 1 to LOC 5 (proximal to distal) in ST steaks. Steak LOC 5 had the longest sarcomeres over LOC 1, 2, and 3 on d 7, 14, and 28 (P < 0.01) in the ST; LOC 4 and 5 also had a greater percentage of Type I fibers (P < 0.01). Muscle fiber size in ST steaks decreased (P = 0.01) from LOC 1 to LOC 5. As DOA increased, intact calpain-1 decreased (quadratic; P < 0.01), with intact calpain-1 completely disappearing by d 56 and d 28 in the ST and LL, respectively. Intact desmin and troponin-T decreased throughout the 112 d in ST and LL steaks (linear; P ≤ 0.03). Degraded desmin-38 kDa increased (P < 0.01) between d 14 and d 28; however, degraded desmin-38 kDa did not continue to degrade (P = 0.76) from d 56 to d 112 in ST steaks. Degraded desmin-35 kDa content, however, continued to increase through d 112 (P < 0.01). Muscle fiber size and type along with sarcomere length played a substantial role in tenderness differences in steak LOC, whereas calpain and proteolytic activity played a substantial role across DOA.
30

Models and factors used for production location decisions: a review and categorizing framework

Thumawongchai, Veerayuth, Huang, Lu January 2011 (has links)
The study of location has a long and extensive history. As this area of study has evolved, there has been an increased recognition of the challenges and the many significant external factors, driven by the changes of trends and criteria on location decisions. Whether it is the world economy, technology and environment issues, and it has affected the existing models used in production location decision.    The primary aim of this thesis was to review the broad base of literature of production location decision, especially on models and factors concerning the manufacturing and supply chain area. The thesis also uncovers previous research that has examined the current status concerning models and factors used in production localisation decision.   Following a brief quantitative analysis of the research area development, the project applied mainly a qualitative approach to the study. Literature databases, literature reviews and case study reports were used as data sources. Literature reviews were used as base for the description, explanation, exploration and correlation analyses within the study.   Based on existing literature, this thesis presents a framework to categorise the existing location models and factors. The framework presents the used models and factors in production location decisions. Three industrial case study reports (from master thesis projects from Väderstad, Alfdex and IKEA) were gathered and used to examine the researchers’ own synthetic framework and further explore the research questions. The result is summarized in the framework that can lead users to understand the current status and the trend concerning the models and factors used in production location decision.     Keywords: Location decision, Production location, Location models and Location factors, Models and actors categorization.

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