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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.
711

Essays on airine competition and network structure

Belford, Carlene. January 2008 (has links)
No description available.
712

Cost-Utility Analysis/Cost Effectiveness of Nursing Care

Vanhook, Patricia M. 25 June 2015 (has links)
No description available.
713

Construction and Analysis of Linear Trend-Free Factorial Designs Under a General Cost Structure

Kim, Kiho 07 August 1997 (has links)
When experimental units exhibit a smooth trend over time or in space, random allocation of treatments may no longer be appropriate. Instead, systematic run orders may have to be used to reduce or eliminate the effects of such a trend. The resulting designs are referred to as trend-free designs. We consider here, in particular, linear trend-free designs for factorial treatment structures such that estimates of main effects and two-factor interactions are trend-free. In addition to trend-freeness we incorporate a general cost structure and propose methods of constructing optimal or near-optimal full or fractional factorial designs. Building upon the generalized foldover scheme (GFS) introduced by Coster and Cheng (1988) we develop a procedure of selection of foldover vectors (SFV) which is a construction method for an appropriate generator matrix. The final optimal or near-optimal design can then be developed from this generator matrix. To achieve a reduction in the amount of work, i.e., a reduction of the large number of possible generator matrices, and to make this whole process easier to use by a practitioner, we introduce the systematic selection of foldover vectors (SSFV). This method does not always produce optimal designs but in all cases practical compromise designs. The cost structure for factorial designs can be modeled according to the number of level changes for the various factors. In general, if cost needs to be kept to a minimum, factor level changes will have to be kept at a minimum. This introduces a covariance structure for the observations from such an experiment. We consider the consequences of this covariance structure with respect to the analysis of trend-free factorial designs. We formulate an appropriate underlying mixed linear model and propose an AIC-based method using simulation studies, which leads to a useful practical linear model as compared to the theoretical model, because the theoretical model is not always feasible. Overall, we show that estimation of main effects and two-factor interactions, trend-freeness, and minimum cost cannot always be achieved simultaneously. As a consequence, compromise designs have to be considered, which satisfy requirements as much as possible and are practical at the same time. The proposed methods achieve this aim. / Ph. D.
714

Life-Cycle Cost-Based Optimal Seismic Design of Structures with Energy Dissipation Devices

Shin, Hyun 05 January 2011 (has links)
Seismic designs of building structures are currently made based on the design criterion of life-safety and this requires that the structures do not collapse to compromise safety of people in the structure, but they can be designed to experience some damage. However, this design approach has allowed large economic losses primarily due to the damage to the nonstructural components at relatively moderate levels of seismic intensities. This led to a new thinking about design approach called performance-based design approach that satisfies the life-safety objective at the same time, reduces the economic loss to an acceptable level. The performance-based design approaches are multi-level design that addresses several different levels of structural performances under different levels of seismic intensities. In this study, we have investigated the use of energy dissipating damping devices to achieve the performance of a building structure in a desirable manner over all levels of seismic intensity. Since the initial motivation of performance-based design was reducing economic loss, the life-cycle cost-based optimization is considered in this study to obtain the optimal designs with different damping devices. For the optimal design, three types of devices are used in this study: fluid viscous dampers, solid visco-elastic dampers, and yielding metallic dampers. The combinations of two different types of dampers are also examined in this study. The genetic algorithm (GA) approach is adopted as an optimizer that searches for the optimal solution in an iterative manner. Numerical results from the application of the optimal design to the selected model building are presented to demonstrate the applicability of the developed approach and to estimate the effectiveness of the obtained optimal design with each device. It is shown in the results that the optimal design with each individual damping devices or the combination of two different types of damping devices are very effective in reducing the expected failure cost as well as the displacement response quantities and fragilities. The results also show that the optimal designs focus relatively more on reducing economic losses for the lower but more frequent excitation intensities as these intensities contribute most to the failure costs. / Ph. D.
715

Design and Prototyoing of a Wireless Data Transceiver in the 900MHz ISM Band

Grady, Benjamin M. 08 May 2000 (has links)
The Communications industry is currently involved in a wireless revolution. Consequently, there is a need for a wide variety of wireless solutions to replace existing wired systems. The major systems, such as cellular and satellite, are costly to put in place and require a low BER (bit error rate) to be successful for their real-time applications. In contrast to this are those systems that can tolerate a higher BER as a trade off for cost (<$50.00) and complexity. A typical application for these lower cost systems is monitoring non-critical data that is not required to be delivered real-time. The work presented here focused on designing, building and testing a Proof of Concept Prototype (POCP) for a low-cost wireless data link (WDL). In a typical WDL application, problems arise when too large a data rate attempts to travel the allotted channel bandwidth in the frequency band of interest. Also, limitations imposed by current radio transceiver technology tend to limit WDL design. The existing sponsor's wired system operates at a 9600 Baud, and presented the opposite problem: the data rate was too low for the RF Microdevices RF2905 used for the POCP. This challenge necessitated the development of a low-cost encoding scheme using standard digital logic gates in place of more costly Manchester Encoding. For the digital logic encoding scheme to work, the crystal oscillators had to be modified. This resolved the problem with the low frequency limitations of the RF2905 phase locked-loop. In addition, the polled, asynchronous, and unbalanced RS485 connections of the wired system had to be adapted to interface with the single-ended data connections of the WDL. Finally, the successful design of a timing scheme, using standard TTL components and balanced to unbalanced drivers, resolved the interface problems resulting in a low-cost WDL designed to operate with an existing wired system without requiring modifications to that system. The WDL is transparent in connection and operation and can be inserted without disrupting the current wired system. / Master of Science
716

Identifying the Economic Barriers to CLT Cost Estimation Among Building Construction Professionals

Stutesman, Jonathan Harley 04 February 2020 (has links)
Cross-laminated timbers (CLTs) are strong and lightweight structural building materials. CLTs are made from renewable wood resources and have significant economic potential as a new value-added product for the United States. However, market penetration has been obstructed by product affordability and lack of availability for use. Previous studies and projects have surveyed opinions of designers and contractors about the adoption of CLTs. No previous study was found that surveyed cost estimators, who serve the essential function of creating economic comparisons of alternative materials in commercial construction. CLTs are not included in these current cost estimation tools and software packages which may be limiting the potential use of CLT in construction. The purpose of this study was to discover if cost estimation is being used to make structural decisions potentially affecting the marketability of CLT use in construction and building design because of the ability to estimate CLTs adequately. Through the use of a survey, the re-designing of a building, and discussions with subject matter experts, this study examined the knowledge level of cross-laminated timbers of under-surveyed building construction professions and the relationship between cost estimation and structural material choices. Their responses are demonstrating the need for better cost estimation tools for cross-laminated timbers such as inclusion in the Construction Specifications Institute's classification systems in order for CLTs to become a more competitive product. The study concluded that cost estimation is important for CLT market development, because it is being used extensively in the construction industry. / Master of Science / Cross-laminated timbers (CLTs) are strong and lightweight structural building materials that also serve as a method of sequestering carbon rather than emitting carbon like more traditional construction materials. CLT construction is straightforward and quick to assemble, requiring minimal time and labor. CLTs are made from abundant and renewable wood resources and have significant economic potential as a job creator and as a new value-added product for the United States. However, market penetration has been obstructed by product affordability and lack of availability for use. Previous studies and projects have surveyed opinions of designers and contractors about CLT use. However, no previous study has been found that examined the opinions of cost estimators, who serve an essential function in providing economic comparisons of different construction systems for designers and building owners to select in the commercial construction area. CLTs are currently not included in these cost estimates, and this lack of information may be limiting the potential of this construction system. The purpose of this study was to discover if cost estimation is being used to make structural decisions potentially affecting the marketability of CLT use in construction and building design because of the ability to estimate CLTs adequately. Through the use of a survey and discussions with subject matter experts, this study examined the knowledge level of crosslaminated timbers of under-surveyed building construction professions and the relationship between cost estimation and structural material choices. They are demonstrating the need for better cost estimation tools for cross-laminated timbers such as inclusion in the Construction Specifications Institute’s classification systems in order for CLTs to become a more competitive product. Cost estimation is performed early in the design process before the structural material has been chosen. However, making cost estimates of CLT materials early in the design process is not a practical solution at this point due to the lack of cost data available. As an alternative solution, this project developed a design tool that is meant to accelerate the design process and allow companies to approach suppliers for quotes, which require mostly complete designs. While this is not a complete solution, if designs are made faster and more effortless, they should also be a more affordable investment for clients. 5 | Page Building construction professionals perceived CLT construction as too expensive, unavailable to the consumer, or unwanted by the client. It was found that the lack of data, due primarily to the material being new to the US construction industry, was a significant barrier to CLT cost estimation. The custom design of many previous CLT projects, due to the lack of CLT construction in the current building codes, limits the collection of standard CLT construction data. There is also an issue with the discrete sizes of CLT panels limiting their competitiveness. These barriers were identified in this study, and further research is needed to develop complete solutions.
717

What is the Cost of an Adequate Vermont High School Education?

Rucker, Frank D. 01 February 2010 (has links)
Access to an adequate education has been widely considered an undeniable right since Chief Justice Warren stated in his landmark decision that “Today, education is perhaps the most important function of state and local governments…it is doubtful that any child may reasonably be expected to succeed in life if he is denied the opportunity of an education” (Brown vs. Board of Education, 1954). State constitutions establish rights to public education. State legislatures define expected outcomes and funding mechanisms to operate schools. Over the past sixteen years, plaintiffs have overwhelmingly prevailed in court cases where they have claimed that children have been denied access to an adequate education. Close scrutiny of state education finance systems revealed that few states had seriously attempted to determine objectively the amount of resources actually required to meet children’s learning requirements (Rebell, 2006). The purpose of this study is to assist policy makers in efforts to link resources with expected and mandated outcomes. The central question addressed is “what is the cost of an adequate high school education?” Recommendations focus on: 1) how an adequate education should be defined; 2) understanding conditions that affect student outcomes; 3) using successful school smart practices to allocate resources; and 4) the cost of adequacy. Findings from this study identified three spending thresholds. Vermont high schools that spent below $10,006/ pupil in total “current expense,” below $685/pupil in student support services, or below $595/pupil in administrative services, were very unlikely to have provided an adequate education. The statewide cost of adequacy requires an additional 4.2% in spending per pupil if all schools spend at the threshold level (based on 4 year averages 2002-2005). Recommendations articulate the need for policy makers to accept responsibility for setting student-outcome standards within a framework that considers student needs and the resources they are willing to appropriate to achieve mandated results. State funding incentives for allocating resources to schools must be reconsidered to address the inequitable system presently in place. Further research which articulates smart practices related to governance systems, school leadership, experiential learning opportunities, and instructional methods is necessary.
718

Commentary: Is cost transparency necessarily good for consumers?

Kuah, A.T.H., Weerakkody, Vishanth J.P. January 2015 (has links)
No / The purpose of this paper is to present a critical viewpoint on the negative aspects of market, price and cost transparencies to consumers in terms of its costs. It adopts an inter-disciplinary approach from the marketing, economics and accounting literature. The paper explores market transparency in the ever-changing world and uses brand names like Starbucks and iPhone to illuminate instances where imperfect markets are supported by consumers. Recognizing the role that the Internet plays in promoting price transparency, it espouses how extant information can add costs and risks to the consumer’s value judgement. Finally, the paper advocates that arbitrary judgements existing in cost accounting make it difficult to compare unit cost. This could result in consumers paying extra money to benefit from cost transparency. This paper argues that three main issues may arise in providing unit cost to the consumers. First, transparency entails built-in costs, whether they are in taxes or product prices. Second, in accounting, unit cost information is currently not equitable between businesses. Finally, the paper argues that extra time and effort in making sense of unit cost information lead to questions about the viability of transparent costing. The arguments for transparency have been widely discussed, supported and promoted by many. While negative aspects are known to businesses, few consider the consumer’s perspective. By amalgamating evidence and arguments from different disciplines, this paper lends value, providing a critical perspective where transparent unit cost revelation can be more costly and less viable than what is assumed.
719

Home Street Home Homelessness - A Case Study of Hamilton

Cagalj, Susan 04 1900 (has links)
<p> Existing in our society today are a number of people that live in the streets and use emergency shelter services for the basic needs of survival. This research report attempts to define the scale and nature of homelessness using Hamilton as a case study. It is a descriptive analysis that provides a synopsis of homelessness in Hamilton and provides recommendations based on individuals that directly work with the homeless. This research invovles a first hand perspective experience with working with the homeless. Therefore, it incorporates the human element involved in homelessness. </p> / Thesis / Bachelor of Arts (BA)
720

Use of Low Order Models for Near-Optimal Control of High Order Systems

de Bruin, Huibregt 25 June 2015 (has links)
<p> Ten different reduced models, of a particular test system are selected. Two cost functions are selected and the test system minimum cost is found for each. The model optimal controls are found for each cost function and are used to provide sub-optimal control of the system using two different methods. The system cost is calculated for each case and compared to the minimum attainable. The reduction methods are compared with a view to application for the near-optimal control of a linear system.</p> / Thesis / Master of Engineering (MEngr)

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