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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.
71

Performance based contracting: A concept for cost-effective operation and maintenance of wind power plants

Dibennardo, Maurizio January 2011 (has links)
No description available.
72

The effect of talk and instructional mode on enhancing secondary English students’ interpretation of, response to, and appreciation for short fiction

Nickerson, Warren Thor 29 September 2006 (has links)
Reading practices in high school English language arts should lead students to write richer, more developed responses to literature. Teacher-led, reflective, and performance-based instructional modes were combined with either talk or writing to produce six activities for enhancing response. A repeated measures design varied the order of the six learning activities for three classes (n=44) in a Midwest suburban high school. Later written responses were scored for interpretation, response, and appreciation. Pearson correlations revealed the task and criteria were reliable. Analyses of variance (ANOVA) found that for interpretation and response, talking led to higher achievement. Conversely, writing was nearly superior to talk for appreciation. Practice and feedback may be more significant than instructional condition for raising the quality of response.
73

A Two-Phase Maintenance and Rehabilitation Framework for Pavement Assets under Performance Based Contracts

Alyami, Zaid January 2012 (has links)
Traditional Canadian pavement construction contracts provide detailed specifications for the work that needs to be carried out. This is the case for both maintenance and rehabilitation contracts. However, for many road agencies around the world, this traditional way of contracting had shortcomings. These agencies have been proactive in changing their contracts to maintain the road networks while reducing the cost. The challenge of maintaining the road networks to the highest possible condition while investing the minimal amount of money has promoted innovative contracting approaches. Furthermore, road agencies have increased the private sector involvement through warranty contracts. According to road agencies around the world, there has been a movement over the last two decades towards Performance Based Contracts (PBCs); a long term warranty contract. In PBCs, the client agency specifies certain clearly defined minimal performance measures to be met or exceeded during the contract period and payments are explicitly linked to the contractor successfully meeting or exceeding those performance measures. Therefore, the PBC maintenance and rehabilitation selection differs significantly from that of traditional asset management contracts and more complex due to the pavement deterioration process and probability of failure to achieve the specified level of service for various performance measures along the contract period. This thesis involves the development of a novel framework that facilitates the selection of maintenance and rehabilitation activities for pavement assets under PBCs. The framework consists of two phases. Phase-One, called the Initial Program, uses historical data, performance modeling, and optimization to establish and select the maintenance and rehabilitation program for the bidding stage. Phase-Two, called Project Asset Management, is implemented after the contract is awarded. This phase uses the contract performance monitoring data and the cost estimate from Phase-One as a baseline budget to update and validate the established program through performance modeling and optimization. A case study using data from the Ministry of Transportation Ontario (MTO) second generation Pavement Management System (PMS2) is used to illustrate the framework.
74

The effect of talk and instructional mode on enhancing secondary English students’ interpretation of, response to, and appreciation for short fiction

Nickerson, Warren Thor 29 September 2006 (has links)
Reading practices in high school English language arts should lead students to write richer, more developed responses to literature. Teacher-led, reflective, and performance-based instructional modes were combined with either talk or writing to produce six activities for enhancing response. A repeated measures design varied the order of the six learning activities for three classes (n=44) in a Midwest suburban high school. Later written responses were scored for interpretation, response, and appreciation. Pearson correlations revealed the task and criteria were reliable. Analyses of variance (ANOVA) found that for interpretation and response, talking led to higher achievement. Conversely, writing was nearly superior to talk for appreciation. Practice and feedback may be more significant than instructional condition for raising the quality of response.
75

Toward advanced analysis in steel frame design

Hwa, Ken 05 1900 (has links)
The trends for analysis and design of steel frames are indicated in this dissertation. The current practice consists of applying the first-order elastic analysis with amplification factors or second-order elastic analysis in combination with the AISC-LRFD interaction equations. Determination of the effective length factors and individual member capacity checks are necessary to select adequate structural member sizes. The direct analysis method is a second-order elastic analysis approach that eliminates the determination of effective length factors from the current AlSC-LRFD method. Unsupported member length is used to calculate the axial strength of a member. Equivalent notional loads and/or modified stiffness are applied together with the external loads to account for the effects of initial out-of-plumbness and inelastic softening. For both AlSC-LRFD and direct analysis methods, a structure is analyzed as a whole, but the axial and flexural strength of each member is examined individually. Inelastic redistribution of internal forces in the structural system cannot be considered. As a result, determined member forces are not correct and more conservative member sizes will be obtained. Moreover, member-based approaches cannot predict structural behaviors such as failure mode and overstength factor. The advanced analysis method considered in this work is a second-order refined plastic hinge analysis in which both effective length factors and individual member capacity checks are not required. In addition, advanced analysis is a structure systembased analysis/design method that can overcome the difficulties of using member-based design approaches. Thus, advanced analysis is a state-of-the-art method for steel structure design. Several numerical examples are provided to show the design details of all three methods. The design requirements corresponding to each analysis approach are illustrated in these examples. The pros and cons of each method are discussed by comparing the design results. Advanced analysis is also a computer-based analysis and design procedure consistent with the features of performance-based design. Applying advanced analysis to performance-based fire resistance and seismic design are proposed. This dissertation shows advanced analysis is efficient in predicting the duration that structures could support load under elevated temperature and capable of determining the performance level of a structure subjected to seismic forces.
76

Towards a Universal and Integrated Digital Representation of Physical Processes

Schwede, Dirk Alexander January 2006 (has links)
Doctor of Philosophy(PhD) / This thesis describes the exploration and the development of computational means to investigate the behaviour of design objects before they are available for investigation in the physical world. The motivation is to inform the design process about the design object’s performance in order to achieve better – more performance-oriented – design outcomes in the sense of energy efficiency and comfort performance than can be achieved by conventional design techniques. The research is structured into five successive parts. - Concept Development – A review of the objective domains comfort assessment and energy efficiency assessment is conducted and the design process, human design activity and the application of simulation in the architectural domain is discussed in order to identify requirements for the development of computational means for design analysis. Requirements regarding model content, model features and model integration are developed. The main requirements are that a highly integrated, three-dimensional and dynamic representation of physical processes is needed and that a universal and integrated representation is required. - Concept Formulation – Based on the identified requirements, the concept for a model is formulated. In order to achieve a universal and integrated representation of physical processes the concept uses the approach of a constructive language. Space is represented with autonomous spatial elements, called congeneric cells. Interaction between the cells is represented by near- and remote-conjunctions. Physical and geometric self-contained formulations of the model reduce the model input requirements, so that geometric information and simple property specification (material, activity) is sufficient to describe the design object in the model. - Model Development – The concept is formulated in mathematical physical terms based on well known physical laws and building physical models (first-principle approach). Heat and moisture conduction, diffusion of various components and a flow model is formulated as near-conjunction processes. Heat radiation, light and sound are modelled with a radiosity approach as remote-conjunctions. The simulation algorithm, which governs the interaction between the cells in order to represent the behaviour of space, is explained. - Computational Implementation – The concept and the model is tested by implementation of a prototype using C++ and OpenGL on a conventional Pentium 4 notebook. The prototype consists of three parts: user-interface, model translator and simulation engine. The user interface functions as model-input and result-output device. The implementation of the concept and of further model parts is described in detail. - Assessment and Testing – The developed concept and the model, as implemented in the prototype, are tested and assessed against the initially developed requirements. The physical model is assessed in regard to plausibility and accuracy of the representation of the physical phenomena. At the end of the thesis the project is summarized, the achievements of the project’s objectives are discussed critically and issues for future research are suggested. Possible applications of the developed model are listed, and the contributions to the application of computational simulation in the architectural domain, developed in this research, are named. At the current stage the required processing time and high memory requirements prevent implementation of a design assessment system, following the suggested concept, at a useful scale. Also the developed physical models require further refinement and testing. Although the general feasibility of the concept and the model was successfully demonstrated, its implementation in a fully applicable design assessment system based on the universal and integrated representation of physical processes was not achieved at this stage. While detailed description and analysis is given in the body of the thesis, detailed formulations of the work and the developed model are given in the appendix. The body and the appendix together provide a complete picture of the research presented.
77

Application of Sliding Isolation Bearings with Upward Lifting Mechanism for Seismic Performance Enhancement of Multi-Story Structures / 多層構造物の地震時性能向上のための上揚運動機構を有するすべり免震支承の適用

FAKHOURI, Muhannad Yacoub 26 March 2012 (has links)
Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第16821号 / 工博第3542号 / 新制||工||1535(附属図書館) / 29496 / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 小池 武, 教授 竹脇 出, 准教授 五十嵐 晃 / 学位規則第4条第1項該当
78

Lower extremity function in patients following hip arthroscopy and an asymptomatic control group. A cross-sectional comparison based on self- reported outcomes and performance based measures.

Nilsson, Johanna January 2017 (has links)
Background: This study aimed to evaluate physical function, measured with self-reported outcomes and performance-based measures (PBMs), in patients 6-10 months following hip arthroscopy (HA) compared to an asymptomatic control group.   Methods: A cross-sectional comparison (21 patients, 22 controls) based on self-reported outcomes (HAGOS), range of motion (ROM), muscle strength and PBMs (The Y-balance test (cm), medial and lateral triple hop test (cm) and Illinois agility test (s)). Independent sample t test was performed to asses between-group differences.   Results: HA-patients reported significantly worse self-reported outcomes in all HAGOS subscales, greatest difference was in QoL (-37,3 (95% CI -47,9; -26,8) p<0.001). HA-patients also reported significantly lower results (p<0.05) in active and passive flexion (ROM) and external rotation (strength). No significant differences were observed regarding PBMs.   Conclusions: HA-patients reported significantly lower hip function following HA compared with the control group. Lower muscle strength and ROM were observed in patients however, few differences were significant. No significant differences were observed regarding PBMs. This could indicate that physical function is re-established in patients 6-10months after surgery or that tests were not sensitive enough to detect potential remaining functional limitations in this patient group.
79

Simplified thermal and structural analysis methods for cold-formed thin-walled steel studs in wall panels exposed to fire from one side

Shahbazian, Ashkan January 2013 (has links)
The advantages of cold-formed thin-walled steel studs are many and their applications in building constructions continue to grow. They are used as load-bearing members. An example is lightweight wall panel assemblies which consist of channel steel studs with gypsum plasterboard layers attached to the two flanges, often with interior insulation. At present, expensive fire tests or advanced numerical modelling methods are necessary in order to discover the fire resistance of such wall assemblies. For common practice this is not effective and a simplified method, suitable for use in daily design, is necessary. The aim of this research is to develop such simplified methods. The first main objective of this study is to develop a simple approach to calculate the temperature distributions in the steel section, in particular the temperatures on both the exposed and unexposed sides when the panel is exposed to fire exposure from one side. These two temperatures are the most influential factors in the fire resistance of this type of wall assembly. The proposed method calculates the average temperatures in the flanges of the steel section and assumes that the temperature in the web is linear. The proposed method is based on a simple heat balance analysis for a few nodes representing the key components of the wall panel. The thermal resistance of these nodes are obtained by the weighted average of thermal resistances in an effective width of the panel within which heat transfer in the panel width direction is assumed to occur. The proposed method has been extensively validated by comparison with numerical parametric studies. In order to calculate the ultimate capacity of steel studs, the traditional method is by using effective width. However, this method is now being questioned as it considers elements of section in isolation and does not consider interaction between the elements. In addition, this method is not appropriate to be extended to steel studs under fire conditions. The cross-section under fire conditions has non-uniform temperature distribution which results in the non-uniform distribution of mechanical properties. Using an effective width method to deal with this problem will require many assumptions whose accuracy is uncertain. Recently, the direct strength method (DSM) has been developed and its accuracy for ambient applications has been comprehensively validated. This method calculates cross-sectional plastic resistance and elastic critical loads for local, distortional and global buckling modes with the aid of simple computer programs. The elastic and plastic resistances are then combined to give the ultimate resistance of the structure using interaction equations. This method is suited to steel studs with non-uniform temperature distribution in the cross-section. The second main objective of this study is to extend the direct strength method for application to thin-walled steel studs having non-uniform elevated temperature distributions in the cross-section. It has been found that the DSM concept is applicable, but the interaction equations should be modified to allow for the effects of elevated temperature (non-uniform temperature distribution and changes in stress-strain relationships). Also the effects of thermal bowing should be included when calculating the plastic resistance and the elastic buckling loads of the cross-section. This research has proposed new interaction equations and has developed design tools. By comparing the results of the proposed method with validated Finite Element simulations over a very large range of parametric studies, the proposed method has been demonstrated to be valid. The validation studies include both standard and parametric fire exposures and are generally applicable.
80

A Methodological Framework for Modeling Pavement Maintenance Costs for Projects with Performance-based Contracts

Panthi, Kamalesh 12 November 2009 (has links)
Performance-based maintenance contracts differ significantly from material and method-based contracts that have been traditionally used to maintain roads. Road agencies around the world have moved towards a performance-based contract approach because it offers several advantages like cost saving, better budgeting certainty, better customer satisfaction with better road services and conditions. Payments for the maintenance of road are explicitly linked to the contractor successfully meeting certain clearly defined minimum performance indicators in these contracts. Quantitative evaluation of the cost of performance-based contracts has several difficulties due to the complexity of the pavement deterioration process. Based on a probabilistic analysis of failures of achieving multiple performance criteria over the length of the contract period, an effort has been made to develop a model that is capable of estimating the cost of these performance-based contracts. One of the essential functions of such model is to predict performance of the pavement as accurately as possible. Prediction of future degradation of pavement is done using Markov Chain Process, which requires estimating transition probabilities from previous deterioration rate for similar pavements. Transition probabilities were derived using historical pavement condition rating data, both for predicting pavement deterioration when there is no maintenance, and for predicting pavement improvement when maintenance activities are performed. A methodological framework has been developed to estimate the cost of maintaining road based on multiple performance criteria such as crack, rut and, roughness. The application of the developed model has been demonstrated via a real case study of Miami Dade Expressways (MDX) using pavement condition rating data from Florida Department of Transportation (FDOT) for a typical performance-based asphalt pavement maintenance contract. Results indicated that the pavement performance model developed could predict the pavement deterioration quite accurately. Sensitivity analysis performed shows that the model is very responsive to even slight changes in pavement deterioration rate and performance constraints. It is expected that the use of this model will assist the highway agencies and contractors in arriving at a fair contract value for executing long term performance-based pavement maintenance works.

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