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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.
1

Surface pressure and seated discomfort

Shen, Wenqi January 1994 (has links)
This thesis presents experimental studies on the relationship between external surface pressure and the perceived discomfort in seated body areas, in particular those under the ischial tuberosity and the mid-thigh. It consists of three parts. Part one provides a comprehensive review of the existing knowledge concerning seated discomfort. The current assessment methods of seated discomfort are summarised, with the emphasis on the validity and reliability of the rating scale methods. The implications of surface pressure to seated people are outlined from the perspective of clinical, sensory and perceptual, and ergonomics domains. A brief review of current technologies for pressure measurement is also provided. Part two presents the experimental work. It starts with an exploratory assessment model of seated discomfort, based on pressure measures. Two preliminary experiments were conducted to test the feasibility of the model. Three further psychophysical experiments were carried out to test the validity and reliability of the selected six rating scales, and to investigate the effects of surface pressure levels on perceived pressure intensity and discomfort in the seated mid-thigh and ischial tuberosity areas. Surface pressure stimuli were applied to a seated body area of 3,318 mm2• Subjects judged three items of sensations: pressure intensity, local discomfort, and the overall discomfort. The main results are: I) A 50-point category partitioning scale was identified to be most sensitive and reliable for scaling pressure intensity and discomfort; 2) Sensations of pressure intensity and discomfort linearly increase with the logarithm of the pressure stimulus level; 3) Thresholds for pressure intensity and discomfort in the seated ischium and thigh areas were derived; 4) The sensitivity of intensity and discomfort to the stimuli differs between the locations .The mid-thigh is more sensitive to surface pressure than the ischium. It is considered that this is due to differences in load adaptation, body tissue composition and deformation; 5) Local pressure discomfort dominates the overall discomfort, and ratings of the local discomfort are higher than those of overall discomfort. Part three discusses the findings from this research. Four integration models of the overall discomfort from local discomfort components were proposed. The Weighted Average model asserts that the overall discomfort is a linear combination of local discomfort components, and that the weight of each local discomfort is the proportion of this component out of the arithmetic sum of all local discomfort components. The mechanisms of discomfort were analysed. The fundamental research presented herein uniquely contributes to the knowledge on the human perception of seated pressure discomfort. Although this is not application based, the findings contribute to the methods of seating comfort evaluation as well as provide criteria by which seat designers may formulate design requirements.
2

Effektivisering av urvalsprocesser vid analysering av björnspillning : Ett förslag till den svenska förvaltningen av brunbjörn Ursus arctos

Gustafsson, Jonas January 2015 (has links)
The aim with this report is to formulate a strategic method to optimize selection processes of DNA-samples from a faeces inventory to identify as many individuals in as few analyzes as possible, and by that keep down the costs of brown bear management. Brown bear management in Sweden founds today on results from faeces inventory and is substantially led by the county administration boards. Data from the years of 2004 and 2009´s inventories in Västerbotten was used to test and evaluate different methods in selection processes of which faeces that should be sampled. Comparison were made between making selection by chance, by spatial distribution and by calculating variations in logistic regressions coefficient b, in other words bear density and probability in finding same individual in several faeces. We can show making selection by chance is the most uncertain method. Making selection by spatial distribution, without take in account variations in b, provides the highest number of identified individuals at a low labour and thus a low cost. Therefor we strongly recommend future brown bear management to, if not possible to sample all faces in a dataset, make selection by spatial distribution to minimize the risk of sampling the same bear several times.
3

A Comparison of Methods to Construct an Optimal Membership Function in a Fuzzy Database System

Cunningham, Joanne Marie 01 January 2006 (has links)
A fuzzy set is one in which membership in a category is not Boolean, rather items have a degree of membership. Fuzzy databases expand on this idea by storing fuzzy data and allowing data to be retrieved based on its degree of membership. Determining the degree of membership that satisfies the largest number of users is difficult. Five different methods of determining the membership function: the Direct Rating Method, the Random Method with step sizes of .02 and .03, the Steplock Method, and the Weighted Average Method, were compared on the basis of convergence and user satisfaction. The results support use of the Direct Rating Method and the Steplock Method in conjunction with each other, to produce the membership function in the least time and with the highest user satisfaction.
4

Multi-resolution methods for high fidelity modeling and control allocation in large-scale dynamical systems

Singla, Puneet 16 August 2006 (has links)
This dissertation introduces novel methods for solving highly challenging model- ing and control problems, motivated by advanced aerospace systems. Adaptable, ro- bust and computationally effcient, multi-resolution approximation algorithms based on Radial Basis Function Network and Global-Local Orthogonal Mapping approaches are developed to address various problems associated with the design of large scale dynamical systems. The main feature of the Radial Basis Function Network approach is the unique direction dependent scaling and rotation of the radial basis function via a novel Directed Connectivity Graph approach. The learning of shaping and rota- tion parameters for the Radial Basis Functions led to a broadly useful approximation approach that leads to global approximations capable of good local approximation for many moderate dimensioned applications. However, even with these refinements, many applications with many high frequency local input/output variations and a high dimensional input space remain a challenge and motivate us to investigate an entirely new approach. The Global-Local Orthogonal Mapping method is based upon a novel averaging process that allows construction of a piecewise continuous global family of local least-squares approximations, while retaining the freedom to vary in a general way the resolution (e.g., degrees of freedom) of the local approximations. These approximation methodologies are compatible with a wide variety of disciplines such as continuous function approximation, dynamic system modeling, nonlinear sig-nal processing and time series prediction. Further, related methods are developed for the modeling of dynamical systems nominally described by nonlinear differential equations and to solve for static and dynamic response of Distributed Parameter Sys- tems in an effcient manner. Finally, a hierarchical control allocation algorithm is presented to solve the control allocation problem for highly over-actuated systems that might arise with the development of embedded systems. The control allocation algorithm makes use of the concept of distribution functions to keep in check the "curse of dimensionality". The studies in the dissertation focus on demonstrating, through analysis, simulation, and design, the applicability and feasibility of these ap- proximation algorithms to a variety of examples. The results from these studies are of direct utility in addressing the "curse of dimensionality" and frequent redundancy of neural network approximation.
5

Weighted Average Based Clock Synchronization Protocols For Wireless Sensor Networks

Swain, Amulya Ratna 04 1900 (has links) (PDF)
Wireless Sensor Networks (WSNs) consist of a large number of resource constrained sensor nodes equipped with various sensing devices which can monitor events in the real world. There are various applications such as environmental monitoring, target tracking forest fire detection, etc., which require clock synchronization among the sensor nodes with certain accuracy. However, a major constraint in the design of clock synchronization protocols in WSNs is that sensor nodes of WSNs have limited energy and computing resources. Clock synchronization process in the WSNs is carried out at each sensor node either synchronously, i.e., periodically during the same real-time interval, which we call synchronization phase, or asynchronously, i.e., independently without worrying about what other nodes are doing for clock synchronization. A disadvantage of asynchronous clock synchronization protocols is that they require the sensor nodes to remain awake all the time. Therefore, they cannot be integrated with any sleep-wakeup scheduling scheme of sensor nodes, which is a major technique to reduce energy consumption in WSNs. On the other hand, synchronous clock synchronization protocols can be easily integrated with the synchronous sleep-wakeup scheduling scheme of sensor nodes, and at the same time, they can provide support to achieve sleep-wakeup scheduling of sensor nodes. Essentially, there are two ways to synchronize the clocks of a WSN, viz. internal clock synchronization and external clock synchronization. The existing approaches to internal clock synchronization in WSNs are mostly hop-by-hop in nature, which is difficult to maintain. There are also many application scenarios where external clock synchronization is the only option to synchronize the clocks of a WSN. Besides, it is also desired that the internal clock synchronization protocol used is fault-tolerant to message loss and node failures. Moreover, when the external source fails or reference node fails, the external clock synchronization protocol should revert back to internal clock synchronization protocol with/without using any reference node. Towards this goal, first we propose three fully distributed synchronous clock synchronization protocols, called Energy Efficient and Fault-tolerant Clock Synchronization (EFCS) protocol, Weighted Average Based Internal Clock Synchronization (WICS) protocol, and Weighted Average Based External Clock Synchronization (WECS) protocol, for WSNs making use of peer-to-peer approach. These three protocols are dynamically interchangeable depending upon the availability of external source or reference nodes. In order to ensure consistency of the synchronization error in the long run, the neighboring nodes need to be synchronized with each other at about the same real time, which requires that the synchronization phases of the neighboring nodes always overlap with each other. To realize this objective, we propose a novel technique of pullback, which ensures that the synchronization phases of the neighboring nodes always overlap. In order to further improve the synchronization accuracy of the EFCS, WICS, and WECS protocol, we have proposed a generic technique which can be applied to any of these protocols, and the improved protocols are referred as IEFCS, IWICS, and IWECS respectively. We then give an argument to show that the synchronization error in the improved protocols is much less than that in the original protocols. We have analyzed these protocols for bounds on synchronization error, and shown that the synchronization error is always upper bounded. We have evaluated the performance of these protocols through simulation and experimental studies, and shown that the synchronization accuracy achieved by these protocols is of the order of a few clock ticks even in very large networks. The proposed protocols make use of estimated drift rate to provide logical time from the physical clock value at any instant and at the same time ensure the monotonicity of logical time even though physical clock is updated at the end of each synchronization phase. We have also proposed an energy aware routing protocol with sleep scheduling, which can be integrated with the proposed clock synchronization protocols to reduce energy consumption in WSNs further.
6

Investigating certain share buyback transactions by companies listed on the JSE for the period 2000 to 2005

De Goede, Andre 12 1900 (has links)
Thesis (MBA (Business Management))--University of Stellenbosch, 2007. / ENGLISH ABSTRACT: Prior to 30 June 1999 companies in South Africa were not allowed to buy back their own shares. Amendments to the Companies Act, the Companies Amendment Act (Act 37 of 1999) radically changed the philosophy around capital maintenance. The result of this amendment is that a company is allowed to buy back its own shares and finance the backbuying of its shares under certain circumstances. A sample of 140 companies listed on the Johannesburg Securities Exchange for the period 2000 to 2005 was selected. The backbuying of shares by the relevant company, subsidiary and trust was analysed for the period 2000 to 2005. For the purposes of this empirical study, the financial sector, as well as the alternative exchange, that is focussed on good quality small and medium-sized high growth companies, were excluded during sample selection. The outcome of this exploratory study is the identification of the fact that a share buyback took place or not in Tables 4.1 and 4.2; a summary of the number of shares bought back in Table 4.3; and, in Table 4.4, a summary of the number of shares bought back, expressed as a percentage of the weighted average number of shares in issue. / AFRIKAANSE OPSOMMING: Maatskappye in Suid-Afrika was voor 30 Junie 1999 deur die Maatskappywet verbied om hul eie aandele terug te koop. Wysigings aan die Maatskappywet, naamlik die Wysigingswet op Maatskappye (wet 37 van 1999) het ’n radikale verandering bewerkstellig in die filosofie rakende kapitaalinstandhouding. Die gevolg van dié wysigingswetgewing is dat maatskappye sedert 30 Junie 1999 hul eie aandele kan terugkoop en in sekere omstandighede die aankoop van hul eie aandele finansier. ’n Steekproef van 140 genoteerde maatskappye op die Johannesburgse Aandelebeurs is geselekteer vir die tydperk 2000 tot 2005. Die terugkooptransaksies van aandele deur die betrokke maatskappy, filiaal en trust is opgesom vir die tydperk 2000 tot 2005. Hierdie empiriese ondersoek het die finansiële sektor, asook die alternatiewe beurs van die Johannesburgse Aandelebeurs, wat fokus op goeie kwaliteit klein en mediumgrootte maatskappye met groot groeipotensiaal, tydens die steekproefseleksie uitgesluit. Die resultate van hierdie empiriese ondersoek is die identifisering en opsomming van die terugkooptransaksies van aandele vir die steekproef in Tabelle 4.1 en 4.2; ’n opsomming in Tabel 4.3 van die getal aandele teruggekoop; en ’n opsomming in Tabel 4.4 van die getal aandele teruggekoop, uitgedruk as ’n persentasie van die gemiddelde getal uitgereikte aandele.
7

Ocenenie Volkswagen Group / Valuation of Volkswagen Group

Šusták, Tomáš January 2010 (has links)
Objective of the thesis is determination of Volkswagen Group's equity intrinsic value. Basic starting point of the analysis is seggregation of consolidated financial statements into financial and production division, which are valuated separately. The production division is valuated using both enterprise discounted cashflow and discounted economic profit analysis. Equity cashflow valuation is used to derive value of the financial division. Results of valuation implied by income approach are then compared with market multiples valuation.
8

Investeringskalkyl på självtvätthall för Vetlanda Vägkrog AB / Investment calculation of a self-service car wash facility

Öksuz, Baris, Elvung, John, Tadaris, Sergon January 2014 (has links)
Background and problem: Since the new law took place in 1999, it has been illegal towash a car with substances that can damage the environment on a paved street or on a driveway through a garage. This has conveyed to a new industry where more and more self-service car wash facility have opened around the country. Vetlanda Vägkrog AB has since 2012 been planning to install manual self-service car wash facility at the back of their restaurant business. The authors mission was to make an analysis in order to examine whether an investment of carwashes are lucrative enough for Vetlanda Vägkrog AB. Aim: The study's main objective was to analyze the profitability of an investment in a self-service car wash facility at Vetlanda Vägkrog AB, based on given data. The authors sub-aim was to clarify which factors in general that had played the greatest part in the establishment of a self-service car wash facility. Method: The authors have used an abductive approach in order to fulfill the aim of the study. Furthermore, have the authors used semi-structured interviews in order to gather all empirical data. The interviews were performed on the suppliers, municipal employees and the two owners of Vetlanda Vägkrog AB. The collected data is then explained using theory and henceforth meet the purpose. Conclusion: The results of this study shows that the investment of a self-service car wash facility based on Vetlanda Vägkrog AB conditions is economically efficient and profitable. Net present value method, Pay back and internal rate of return (IRR) is the following methods that the authors consistently have used in order to solve this task. An analysis of three different outcomes were made on the variables that might influence the results, for instance volume and periodic payments has been done in order to get an idea of how sensitive the estimate was. / Bakgrund och problem: Efter den nya lagen som trädde fram 1999 förbjuds tvätt avbilen med ämnen som skadar miljön på en asfalterad gata eller garageuppfart. Detta har medfört till en ny bransch då allt flera självtvätthallar har öppnats runt om i landet. Vetlanda Vägkrog AB har sedan 2012 haft planer på att installera manuella tvätthallar på baksidan av restaurangverksamheten. Vårt uppdrag var att göra en analys där vi granskade om en investering av biltvättar var lukrativt för Vetlanda Vägkrog AB. Syfte: Studiens huvudsyfte var att analysera lönsamheten för en investering i en biltvätthall åt Vetlanda Vägkrog AB, utifrån given data. Delsyftet blev att belysa vilka generella faktorer som hade spelat störst roll vid ett upprättande av en självtvätthall. Metod: För att uppfylla syftet med studien har vi utgått från en abduktiv metod. Vihar genom semistrukturerade intervjuer samlat empiri från leverantörer, kommunalanställda och två av delägarna för Vetlanda Vägkrog AB. Det materialet förklaras sedan med hjälp av teori för att slutligen uppfylla syftet. Slutsats: Resultatet av vår undersökning visar att investering av en självtvätthallutifrån Vetlanda Vägkrog AB förutsättningar är ekonomiskt effektiv och lönsamt. För att lösa uppgiften användes följande metoder payback-metoden, nuvärdemetoden och internräntemetoden.En analys med tre olika utfall gjordes på de variabler som kunde tänkas påverka resultatet, exempelvis volym och särutbetalningar har gjorts för att få en uppfattning påhur känslig kalkylen var. Samtliga utfall påvisade positivt resultat.
9

Náklady na kapitál / Cost of capital

LACINOVÁ, Dana January 2016 (has links)
This master thesis's aim is to determine the price of the individual components of the company´s capital and to consider approaches to capital costs including their influence on the scale of the business performance. The thesis is divided into two main parts. In the theoretical part I deal with the capital structure of property, theories of its optimization, approaches to cost calculation of the equity and foreign capital. Also the weighted averages costs of capital were described. Furthermore, the economic value added as a method of an evaluation of busi-ness performance was defined. In the practical part there are several basic information about the rated compa-ny defined in the introduction. In the next part of the thesis I detect the price of the individual components of the company's capital and I judge approaches to capital cost, including their impact on economic value added. As a basis for the evaluation serve the financial statements of the company and information from company's management. To determine the cost of capitals following models were used: capital asset pricing model (CAPM) and the modular model. Overall financial situation of the business can be assessed negatively. In all three variations of calculating economic value added, the company didn´t generate an economic profit within years 2010 2014.
10

DETERMINANTS OF BILATERAL FOREIGN DIRECT INVESTMENTS: AN EMPIRICAL STUDY

Wang, Di 01 May 2020 (has links)
In this dissertation, we use unique data set to examine bilateral Foreign Direct Investments (FDI) data and find determinant factors of bilateral FDI activities. In Chapter 1, we examine the relationships among the bilateral annual non-aggregated national level FDI, all levels of Economic Integration Agreements (EIAs) and political turnovers happened in both FDI exporting countries and FDI importing countries. In Chapter 2, we test the Tariff-Jumping FDI hypothesis and Export-Oriented FDI hypothesis. In Chapter 3, we examine and determine the key determinant factors of Cross-Hauling FDI status.

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