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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.
11

Laminar Filmwise Condensation Of Flowing Vapor On A Sphere

Erol, Dogus 01 June 2004 (has links) (PDF)
The objective of this study is to analyze theoretically the laminar film condensation of water vapor flowing on a sphere. For this purpose, the problem was handled by including all of the two-phase boundary layer parameters such as gravity, effect of vapor shear, inertia, energy convection and pressure gradient. For this full two-phase boundary layer system, the boundary layer equations, boundary conditions and the interfacial conditions were first analyzed, and then discretized. A computer program in Mathcad, solving these discretized equations, was written to obtain the velocity and temperature profiles within the condensate, the velocity profiles within the vapor, the condensate film thickness and the local Nusselt number. The effects of pressure gradient, gravity, vapor oncoming velocity and sphere radius on these parameters were examined. By alternating the formulation of the problem, the results for the flow over a horizontal cylinder were obtained. These results were then compared with those for the sphere. Finally, the results for the system with Mercury vapor flowing on a sphere were obtained. All of these results were represented as diagrams and tables, and were discussed at the end of the study.
12

Isomorphisms Of L-kothe Spaces

Karapinar, Erdal 01 October 2003 (has links) (PDF)
In this thesis, we study on l-K&ouml / the spaces. By the help of interpolation theory, we use linear topological invariants to get isomorphisms of Cartesian products of l-power series spaces. We also see that multirectangular n-equivalent characteristics is linear toplogical invariant for power l-K&ouml / the spaces of first type.
13

The Nonextensive Generalisation Of Boltzmann-gibbs Its Applications

Bagci, Gokhan B 01 January 2005 (has links) (PDF)
This thesis analyzes the nonextensive generalization of Boltzmann-Gibbs statistics and study its applications to some physical models such as isotropic rigid and non-rigid rotators. The thesis will also try to show what kind of internal energy constraint must be chosen for entropy optimization in a mathematically consistent manner.
14

Invariant Subspaces Of Positive Operators On Riesz Spaces And Observations On Cd0(k)-spaces

Caglar, Mert 01 August 2005 (has links) (PDF)
The present work consists of two main parts. In the first part, invariant subspaces of positive operators or operator families on locally convex solid Riesz spaces are examined. The concept of a weakly-quasinilpotent operator on a locally convex solid Riesz space has been introduced and several results that are known for a single operator on Banach lattices have been generalized to families of positive or close-to-them operators on these spaces. In the second part, the so-called generalized Alexandroff duplicates are studied and CDsigma, gamma(K, E)-type spaces are investigated. It has then been shown that the space CDsigma, gamma(K, E) can be represented as the space of E-valued continuous functions on the generalized Alexandroff duplicate of K.
15

On The Generalizations And Properties Of Abramovich-wickstead Spaces

Polat, Faruk 01 November 2008 (has links) (PDF)
In this thesis, we study two problems. The first problem is to introduce the general version of Abramovich-Wickstead type spaces and investigate its order properties. In particular, we study the ideals, order bounded sets, disjointness properties, Dedekind completion and the norm properties of this Riesz space. We also define a new concrete example of Riesz space-valued uniformly continuous functions, denoted by CDr0 which generalizes the original Abramovich-Wickstead space. It is also shown that similar spaces CD0 and CDw introduced earlier by Alpay and Ercan are decomposable lattice-normed spaces. The second problem is related to analytic representations of different classes of dominated operators on these spaces. Our main representation theorems say that regular linear operators on CDr0 or linear dominated operators on CD0 may be represented as the sum of integration with respect to operator-valued measure and summation operation. In the case when the operator is order continuous or bo-continuous, then these representations reduce to discrete parts.
16

Characterization and Mechanical Properties of Nanoscale Precipitates in Modified Al-Si-Cu Alloys Using Transmission Electron Microscopy and 3D Atom Probe Tomography.

Hwang, Junyeon 05 1900 (has links)
Among the commercial aluminum alloys, aluminum 319 (Al-7wt%Si-4wt%Cu) type alloys are popularly used in automobile engine parts. These alloys have good casting characteristics and excellent mechanical properties resulting from a suitable heat treatment. To get a high strength in the 319 type alloys, grain refining, reducing the porosity, solid solution hardening, and precipitation hardening are preferred. All experimental variables such as solidification condition, composition, and heat treatment are influence on the precipitation behavior; however, precipitation hardening is the most significant because excess alloying elements from supersaturated solid solution form fine particles which act as obstacles to dislocation movement. The challenges of the 319 type alloys arise due to small size of precipitate and complex aging response caused by multi components. It is important to determine the chemical composition, crystal structure, and orientation relationship as well as precipitate morphology in order to understand the precipitation behavior and strengthening mechanism. In this study, the mechanical properties and microstructure were investigated using transmission electron microscopy and three dimensional atom probe tomography. The Mn and Mg effects on the microstructure and mechanical properties are discussed with crystallographic study on the iron intermetallic phases. The microstructural evolution and nucleation study on the precipitates in the low-Si 319 type aluminum alloys are also presented with sample preparation and analysis condition of TEM and 3DAP tomography.
17

Convergence Of Lotz-raebiger Nets On Banach Spaces

Erkursun, Nazife 01 June 2010 (has links) (PDF)
The concept of LR-nets was introduced and investigated firstly by H.P. Lotz in [27] and by F. Raebiger in [30]. Therefore we call such nets Lotz-Raebiger nets, shortly LR-nets. In this thesis we treat two problems on asymptotic behavior of these operator nets. First problem is to generalize well known theorems for Ces`aro averages of a single operator to LR-nets, namely to generalize the Eberlein and Sine theorems. The second problem is related to the strong convergence of Markov LR-nets on L1-spaces. We prove that the existence of a lower-bound functions is necessary and sufficient for asymptotic stability of LR-nets of Markov operators.
18

Uncertainty Assessment In Reserv Estimation Of A Naturally Fractured Reservoir

Ericok, Ozlen 01 December 2004 (has links) (PDF)
ABSTRACT UNCERTAINTY ASSESSMENT IN RESERVE ESTIMATION OF A NATURALLY FRACTURED RESERVOIR ERI&Ccedil / OK, &Ouml / zlen M.S., Department of Petroleum and Natural Gas Engineering Supervisor : Prof. Dr. Fevzi G&Uuml / MRAH December 2004, 169 pages Reservoir performance prediction and reserve estimation depend on various petrophysical parameters which have uncertainties due to available technology. For a proper and economical field development, these parameters must be determined by taking into consideration their uncertainty level and probable data ranges. For implementing uncertainty assessment on estimation of original oil in place (OOIP) of a field, a naturally fractured carbonate field, Field-A, is chosen to work with. Since field information is obtained by drilling and testing wells throughout the field, uncertainty in true ranges of reservoir parameters evolve due to impossibility of drilling every location on an area. This study is based on defining the probability distribution of uncertain variables in reserve estimation and evaluating probable reserve amount by using Monte Carlo simulation method. Probabilistic reserve estimation gives the whole range of probable v original oil in place amount of a field. The results are given by their likelyhood of occurance as P10, P50 and P90 reserves in summary. In the study, Field-A reserves at Southeast of Turkey are estimated by probabilistic methods for three producing zones / Karabogaz Formation, Kbb-C Member of Karababa formation and Derdere Formation. Probability density function of petrophysical parameters are evaluated as inputs in volumetric reserve estimation method and probable reserves are calculated by @Risk software program that is used for implementing Monte Carlo method. Outcomes of the simulation showed that Field-A has P50 reserves as 11.2 MMstb in matrix and 2.0 MMstb in fracture of Karabogaz Formation, 15.7 MMstb in matrix and 3.7 MMstb in fracture of Kbb-C Member and 10.6 MMstb in matrix and 1.6 MMstb in fracture of Derdere Formation. Sensitivity analysis of the inputs showed that matrix porosity, net thickness and fracture porosity are significant in Karabogaz Formation and Kbb-C Member reserve estimation while water saturation and fracture porosity are most significant in estimation of Derdere Formation reserves.
19

Barriers to trade and labour mobility in conflict-affected regions: an economy-wide analysis with applications to the Palestinian economy

Agbahey, Johanes Uriel Ibidjola 10 December 2018 (has links)
Der Austausch von Waren, Dienstleistungen und Arbeitskräften wird im Falle von politischen Konflikten gestört. Im Palästinensisch-Israelischen Konflikt macht die Machtasymmetrie die palästinensische Wirtschaft abhängig von Israels Politik. Obwohl dieser Konflikt wegen seiner Gewalt und seinen politischen Entwicklungen in den Medien viel beachtet wird, wurden politische Optionen in den Bereichen Handel und Arbeitsmärkte und deren Auswirkungen auf die palästinensische Ökonomie bislang wenig untersucht und bewertet. Dies ist das Ziel der vorliegenden Arbeit, die sich auf die Ökonomie des Westjordanlands konzentriert. Diese Arbeit macht vier Beiträge zur Wissenschaft: Der erste ist die Entwicklung der ersten Sozialrechnungsmatrix für das Westjordanland. Der zweite ist die empirische Analyse von Auswirkungen unterschiedlicher Arbeitsmarktbedingungen in Gleichgewichtsmodellen. Der dritte ist die Anwendung einer verschachtelten Nutzen-Funktion, die die Vorteile von linearen Ausgabesystemen und konstanter Elastizität von Substitutionsfunktionen kombiniert. Schließlich hat diese Arbeit wichtige politische Implikationen für die Palästinensischen Autonomiebehörde (PA). In Bezug auf die Arbeitsmärkte wird gezeigt, dass es für die PA sinnvoll ist eine verstärkte palästinensische Beschäftigung in Israel anzustreben. Dabei sollten die negative Auswirkungen von aus Israel zufließendem Arbeitseinkommen („Holländische Krankheit“) gelindert werden. Dies könnte die PA durch Besteuerung von palästinensischer Beschäftigung in Israel und Schaffung von Anreizen zur Erhöhung der internationalen Wettbewerbsfähigkeit erreichen. In Bezug auf den Handel zeigt diese Arbeit, dass das die PA eine liberale, nicht diskriminierende Handelspolitik verfolgen sollte. Da Israel auch in Zukunft wohl der dominierende Handelspartner für das Westjordanland bleiben wird, sollte die PA die freiest mögliche Mobilität von Gütern und Dienstleistung zwischen dem Westjordanland und Israel anstreben. / The movement of goods, services and labour is disrupted when conflicts arise. In the case of the Palestinian-Israeli conflict, the asymmetry of power between the two parties leaves the Palestinian economy vulnerable to policies implemented by Israel. While this conflict attracts considerable media attention for its violence and political developments, the assessment of the economy-wide implications of trade and labour market policy options on the Palestinian economy is understudied. Exploring these implications is the objective of this thesis, focusing on the West Bank economy. This thesis makes four contributions to science. The first original contribution is the development of the first social accounting matrix for the West Bank. Second, this thesis contributes to the current state of knowledge by assessing empirically the implications of different labour market conditions in general equilibrium models. Third, this thesis contributes to model development by adopting a nested utility function combining the benefits of linear expenditure systems and constant elasticity of substitution functions to depict household preferences. Finally, this thesis has important policy implications for the Palestinian National Authority (PNA). Seen the limited development options in the West Bank, it is interesting for the PNA to seek an increased Palestinian employment in Israel in order to improve the welfare of Palestinian households. Meanwhile, the “Dutch disease” effects of labour income inflow from Israel can be mitigated by collecting a tax on Palestinians employed in Israel and incentivising the private sector to invest and create employment opportunities in the domestic market. With respect to trade, this thesis finds that the West Bank would be better off with a liberal and non-discriminatory trade policy. As Israel will remain the main trade partner for the West Bank, the PNA should seek the freest possible movement of goods and services between the West Bank and Israel.
20

台灣教育創新模式之探討:兩個表演藝術教育破壞性創新實例 / An education innovation model for Taiwan: two examples of disruptive innovation in performing arts education

紀博善, Dale Albanese Unknown Date (has links)
近年來,創造力教育受到越來越多守門人的關注,包括企業界領袖、學者專家、政策制定者和教育工作者。另外在學術界和教育界,也有 越來越多的人接受「創造力是可以教」的觀念。因此,追求文化和社會適當的教育創新模式來實施創造力教育是非常重要的。 接觸藝術、學習藝術是培養創造力的重要途徑, 但在正式教育體制很難提供機會平等的平台時,相關的教育守門人就必須創造機會解決此一問題。Christensen、Horn與Johnson (2008、2011)也認為傳統的教育創新只是進行永續性的創新,所以他們進而提出破壞性創新的教育模式,以彌補傳統創新教育模式之不足。 本研究的目的是在探討兩個台灣表演藝術教育破壞性創新的個案:紙風車319鄉村兒童藝術工程和台北景文高中之優人神鼓表演藝術班。本研究的研究方法包括文獻分析,深度訪談和觀察。研究結果發現紙風車319鄉村兒童藝術工程的破壞性教育模式提供更多的機會讓偏遠的兒童可以接觸藝術,對他們產生正面的影響。優人神鼓表演藝術班的教育創新模式讓具有藝術興趣和才能的學生開啟創新的學習管道,一方面發展他們的藝術才情,另一方面也可以在正式教育中表現良好。 / In recent years, creativity in education has received increased attention from gatekeepers - the business leaders, scholars, policy-makers, and educators – around the world. There is also growing acceptance in the academic and educational worlds that “creativity can be taught.” Thus it is now crucial to pursue culturally and socially appropriate models for implementing creativity education. Encountering and studying the arts is an important approach to developing creativity. However, when traditional formal education systems are unable to provide an equal platform for encountering the arts, relevant gatekeepers must come up with new solutions. Christensen, Johnson, & Horn (2008; 2011) write that traditionally, educational innovation has relied on sustaining innovation, which they hold is insufficient for new educational demands today. They propose instead a model of disruptive innovation for education, which has greater potential impact on the education system, to help close the gap between educational ideals and practice. Leadbeater and Wong (2010) further categorize innovations in either formal or informal educational settings. This study examines two cases of disruptive innovation in performing arts education from Taiwan: Paper Windmill Theatre’s First Mile, Kid’s Smile 319 Townships Art Project program and the U-Theatre Performing Arts Class at Taipei Jingwen High School. The research methods employed include document analysis, in-depth interviews, and observations. The research findings conclude that the 319 Project's disruptive innovation model for informal education provided children in remote locations with opportunities to encounter the arts, making a positive impact on their lives. The disruptive innovation model for formal education used by the U-Theatre Performing Arts Class gave students with interests and potential in performing arts a channel for their abilities, both helping them develop their artistic interests and talents and enter university.

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