• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 386
  • 132
  • 61
  • 55
  • 33
  • 22
  • 20
  • 14
  • 13
  • 13
  • 11
  • 10
  • 9
  • 7
  • 6
  • Tagged with
  • 883
  • 368
  • 215
  • 91
  • 75
  • 75
  • 73
  • 72
  • 72
  • 64
  • 62
  • 61
  • 59
  • 55
  • 48
  • 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.
421

Sources of Cost Saving Opportunities in Highway Construction Quality Assurance Practices

Uddin, Mohammad M., Newland, J. 31 March 2018 (has links)
US transportation agencies are dealing with shrinking budgets, limited work forces, and deteriorating infrastructure. In order to cope with funding uncertainty, state highway agencies are now looking into their own organizations and identifying programs, practices, and processes that have potential for cost saving. A quality assurance (QA) program is an integral part of highway construction and ensures a project’s contracted level of quality. The cost of quality (conforming and nonconforming) can constitute a sizable part of total construction cost. As the quality assurance programs evolved, various practices and processes were developed over time and later adopted by state highway agencies. These practices and processes include different QA standards and specifications, varying testing methods, central testing lab vs. on site testing, performance based vs. prescribed quality assurance practices, implementation of innovative quality assurance practices, etc. Therefore, there is an opportunity to assess different QA strategies and recommend those practices that are effective and cost efficient. A national survey was conducted by the authors, which provided a detailed mapping of various QA practices and processes used as part of QA programs and identified areas where agencies can focus on for cost savings. The survey found that QA sampling and testing plans, optimization of sampling plans, optimization of QA standards and specifications, and implementation of innovative test methods and processes are the main areas the agencies should focus to lean the current QA programs.
422

Individens sparande : En kvantitativ undersökning om individens sparande i relation till ålder

Fejzullahi, Fiola, Westerlund, Elin January 2022 (has links)
Title: The individuals private savings – A quantitative survey of the individualssavings in relationship to age Authors: Fiola Fejzullahi & Elin Westerlund Study topic: Business Economics, Administration Bachelor Theses, 15 hp Advisor: Bodil Sandén Differences in age can, based on economic theories, explain differences insaving and consumption behaviours for individuals. The study deals withprevious research and factors which explain how and why the individual saves.Based on previous research, the following theories referred to are: the life cyclehypothesis, the permanent income hypothesis and Ricardian equivalence. Thestudy examines whether saving differs between age groups in relation to selectedfactors and theories. The method used is a quantitative survey which dividedinto 417 respondent participations. In this study, we could not see any significant associations for individuals savingand consumption behaviour in different age groups. However, the study hasshown several interesting relationships and non-relationships for selectedfactors in relation to given age groups and savings. For example, the factorincome, according to a cycle hypothesis, is higher for those individuals who arein the middle of their life cycle. Despite this, it was not possible to find anysignificant relationship for factor income in relation to the factor saving. Thiscontradicts the assumptions made in the life cycle and permanent incomehypothesis, which mean that an individuals savings depends on the size of theindividual's income. Additional factors that have contributed to an interesting result for studiesinclude individual financial knowledge, savings management, interest rates andinflation. For the factors financial knowledge, interest rates and inflation, wewere able to find significant correlations in relation to age group. Regarding themanagement of savings, we could not find any significant connection in relationto age group.
423

Energieffektivisering i KTHs huvudbyggnad : En kulturhistorisk byggnad / Energy efficiency in KTH's main building : A historical building

Karout, Kawthar, Ström, Josefine January 2020 (has links)
Med det rådande klimathotet ställs högre krav på fastighetsbranschen att minska sin energianvändning. Denna rapport fokuserar på energieffektivisering i KTHs, Kungliga Tekniska Högskolans, huvudbyggnad som förvaltas av Akademiska Hus. Huset, som är en av KTHs minst energieffektiva hus, är byggt i nationalromantisk byggstil och invigdes 1917. Idag klassificeras byggnaden som en blå byggnad, enligt Stockholms Stadsmuseum, vilket är deras högsta klassificering och betyder att den har ett högt historiskt värde. Denna rapport studerar och utvärderar de energibesparingsåtgärder som Akademiska Hus har genomfört i huvudbyggnaden sedan 2016. Ytterligare studeras andra energieffektiviseringsåtgärder i andra hus med kulturhistoriska värden. En undersökning över befintliga tekniker och metoder för energieffektivisering redovisas även i rapporten. Resultatet visar att många energibesparingsåtgärder har genomförts i huset och lett till förbättring men denna förbättring motsvarar inte Akademiska Hus mål om en energiminskning på minst 3 % per år. Det finns nya tekniker som kan implementeras i olika delar av huset för att minska energianvändningen utan att påverka det kulturhistoriska värdet. En av dessa tekniker är att optimera styrning av värme- och kylsystemet. / With the current climate threat, higher demands are placed on the real estate industry to reduce its energy use. This report focuses on the energy efficiency in KTH's, Royal Institute of Technology’s, main building, which is managed by Akademiska Hus. The building, which is one of KTH's least energy-efficient buildings, is built in a national romantic building style and opened in 1917. Today, the building is classified as a blue building, according to the Stockholm City Museum, which is their highest classification and means that it has a high cultural-historical value. This report studies and evaluates the energy saving measures that Akademiska Hus has implemented in the main building since 2016. Furthermore, energy saving measures are being studied in other houses with cultural-historical values. A study of other technologies and methods for energy conservation has also been done in the report. The results shows that many energy saving measures have been implemented in the main building and have led to improvement, but this improvement does not meet Akademiska Hus's goal of an energy reduction of at least 3 % per year. There are new technologies that can be implemented in different parts of the building to reduce the energy used. One of these methods is the optimization of heating and cooling system.​
424

Head-of-Line Blocking Reduction in Power-Efficient Networks-on-Chip

Escamilla López, José Vicente 03 November 2017 (has links)
Tesis por compendio / Nowadays, thanks to the continuous improvements in the integration scale, more and more cores are added on the same chip, leading to higher system performance. In order to interconnect all nodes, a network-on-chip (NoC) is used, which is in charge of delivering data between cores. However, increasing the number of cores leads to a significant power consumption increase, leading the NoC to be one of the most expensive components in terms of power. Because of this, during the last years, several mechanisms have been proposed to address the NoC power consumption by means of DVFS (Dynamic Voltage and Frequency Scaling) and power-gating strategies. Nevertheless, improvements achieved by these mechanisms are achieved, to a greater or lesser extent, at the cost of system performance, potentially increasing the risk of saturating the network by forming congested points which, in turn, compromise the rest of the system functionality. One side effect is the creation of the "Head-of-Line blocking" effect where congested packets at the head of queues prevent other non-blocked packets from advancing. To address this issue, in this thesis, on one hand, we propose novel congestion control techniques in order to improve system performance by removing the "Head-of-Line" blocking effect. On the other hand, we propose combined solutions adapted to DVFS in order to achieve improvements in terms of performance and power. In addition to this, we propose a path-aware power-gating-based mechanism, which is capable of detecting the flows sharing buffer resources along data paths and perform to switch them off when not needed. With all these combined solutions we can significantly reduce the power consumption of the NoC when compared with state-of-the-art proposals. / Hoy en día, gracias a las mejoras en la escala de integración cada vez se integran más y más núcleos en un mismo chip, mejorando así sus prestaciones. Para interconectar todos los nodos dentro del chip se emplea una red en chip (NoC, Network-on-Chip), la cual es la encargada de intercambiar información entre núcleos. No obstante, aumentar el número de núcleos en el chip también conlleva a su vez un importante incremento en el consumo de la NoC, haciendo que ésta se convierta en una de las partes más caras del chip en términos de consumo. Por ello, en los últimos años se han propuesto diversas técnicas de ahorro de energía orientadas a reducir el consumo de la NoC mediante el uso de DVFS (Dynamic Voltage and Frequency Scaling) o estrategias basadas en "power-gating". Sin embargo, éstas mejoras de consumo normalmente se obtienen a costa de sacrificar, en mayor o menor medida, las prestaciones del sistema, aumentado potencialmente así el riesgo de saturar la red, generando puntos de congestión que, a su vez, comprometen el rendimiento del resto del sistema. Un efecto colateral es el "Head-of-Line blocking", mediante el que paquetes congestionados en la cabeza de la cola impiden que otros paquetes no congestionados avancen. Con el fin de solucionar este problema, en ésta tesis, en primer lugar, proponemos técnicas novedosas de control de congestión para incrementar el rendimiento del sistema mediante la eliminación del "Head-of-Line blocking", mientras que, por otra parte, proponemos soluciones combinadas adaptadas a DVFS con el fin de conseguir mejoras en términos de rendimiento y energía. Además, proponemos una técnica de "power-gating" orientada a rutas de datos, la cual es capaz de detectar flujos de datos compartiendo recursos a lo largo de rutas y apagar dichos recursos de forma dinámica cuando no son necesarios. Con todas éstas soluciones combinadas podemos reducir el consumo de energía de la NoC en comparación con otras técnicas presentes en el estado del arte. / Hui en dia, gr\`acies a les millores en l'escala d'integraci\'o, cada vegada s'integren m\'es i m\'es nuclis en un mateix xip, la qual cosa millora les seues prestacions. Per tal d'interconectar tots els nodes dins el xip es fa \'us d'una Xarxa en Xip (NoC; Network-on-Chip), la qual \'es l'encarregada d'intercanviar informaci\'o entre els nuclis. No obstant aix\`o, incrementar el nombre de nuclis en el xip tamb\'e comporta un important augment en el consum de la NoC, la qual cosa fa que aquesta es convertisca en una de les parts m\'es costoses del xip en termes de consum. Per aix\`o, en els \'ultims anys s'han proposat diverses t\`ecniques d'estalvi d'energia orientades a reduir el consum de la NoC mitjançant l'\'us de DVFS (Dynamic Voltage and Frequency Scaling) o estrat\`egies basades en ``power-gating''. Malgrat aix\`o, aquestes millores en les prestacions normalment s'obtenen a costa de sacrificar, en major o menor mesura, les prestacions del sistema i augmenta aix\'i el risc de saturar la xarxa al generar-se punts de congesti\'o, que al mateix temps, comprometen el rendiment de la resta del sistema. Un efecte col-lateral \'es el ``Head-of- Line blocking'', mitjançant el qual, els paquets congestionats al cap de la cua, impedixen que altres paquets no congestionats avancen. A fi de solucionar eixe problema, en aquesta tesi, en primer lloc, proposem noves t\`ecniques de control de congesti\'o amb l'objectiu d'incrementar el rendiment del sistema per mitj\`a de l'eliminaci\'o del ``Head-of- Line blocking'', i d'altra banda, proposem solucions combinades adaptades a DVFS amb la finalitat d'aconseguir millores en termes de rendiment i energia. A m\'es, proposem una t\`ecnica de ``power-gating'' orientada a rutes de dades, la qual \'es capa\c c de detectar fluxos de dades al compartir recursos al llarg de les rutes i apagar eixos recursos de forma din\`amica quan no s\'on necessaris. Amb totes aquestes solucions combinades podem reduir el consum d'energia de la NoC en comparaci\'o amb altres t\`ecniques presents en l'estat de l'art. / Escamilla López, JV. (2017). Head-of-Line Blocking Reduction in Power-Efficient Networks-on-Chip [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/90419 / Compendio
425

A newly designed economizer to improve waste heat recovery: A case study in a pasteurized milk plant

Niamsuwan, S., Kittisupakorn, P., Mujtaba, Iqbal January 2013 (has links)
no / An economizer is normally employed to perform heat recovery from hot exhaust gases to cold fluid. In this work, a newly designed economizer is devised to achieve high heat recovery in a pasteurized milk plant. In the economizer, the hot exhaust gas is divided into two channels flowing up on the left and right sides. After that, it is moving down passing over aligned banks of tubes, which water is flowing inside, in a triple passes fashion. Moreover, three dimensional (3D) models with heat transfer including fluid dynamic have been developed, validated by actual plant data and used to evaluate the performance of the economizer. Simulation results indicate that the newly designed economizer can recover the heat loss of 38% and can achieve the cost saving of 13%.
426

Uncertainty and the effects of a pay-as-you-go social security program on economic growth

McCoy, Christopher January 1981 (has links)
This paper examines the implications of a simplified social security program on future wages and interest rates in the context of uncertainty. Individual consumption-savings and portfolio decisions are integrated into stochastic growth models to find how a social security program alters intermediate and long-run equilibrium factor payments. Two forms of uncertainty are used, namely, production uncertainty and labor force participation. In the first part of this paper recent arguments over how social security affects individual savings are presented and evaluated. Conclusions are made that Feldstein's tax and benefit effects represent the dominant influences on personal savings behavior. A neo-classical growth model is then built, that integrates the two period consumption savings decisions of individuals, and long-run equilibrium wages and interest rates are derived. A social security program is then introduced, causing wages to fall and interest rates to rise. Production uncertainty is then added to the model to find how social security impacts on factor payments via individual consumption and portfolio decisions. Certain questions regarding a social security program are then examined within the production uncertainty model. They include: determining the optimal amount of social security; examining the implications of a fully funded program; studying the relationship between future labor force participation and private investment; examining if optimal social security varies, depending on the individual's wage income and introducing technological growth to see how it effects optimal savings. An alternative form of uncertainty, labor force participation, is then substituted into the model to see if the implications of social security differ, depending on the form of uncertainty. The results are similar to those found in the production uncertainty model. In addition, it is shown that social security tends to increase the variance of future stochastic wages. / Ph. D.
427

Women's Retirement Income Satisfaction and Saving Behaviors

Hsu, Chungwen 11 January 2013 (has links)
Retirement saving research frequently has investigated the differences between working men and working women and primarily focused on the near retirement and retirement years. There is limited research targeting young to old working-age women including those who do not work for pay and are unemployed. The purpose of this study was to examine what factors affect non-retired working-age (25 years and older) women's retirement saving behaviors, retirement savings, and retirement income satisfaction. To implement the study, a research framework was developed based on Deacon and Firebaugh's Family Resource Management Model. The research framework for this study consisted of three major sections: (a) input (demographics, saving motives, retirement saving involvement level, retirement information seeking, current financial assets and debts, and future expectations), (b) throughput (retirement saving behaviors such as calculating needed retirement savings, being a retirement saver, starting saving for retirement age, and being a regular retirement saver), and (c) output (the objective retirement savings and the subjective retirement income satisfaction). An online survey instrument was developed to obtain data for the study. Two pilot tests were conducted to confirm the validity and reliability of the instrument. Data for this study were collected from a national population between May 25, 2012 and May 30, 2012 with 591 valid responses. Several statistical methods were employed: descriptive statistics, one-way between-groups analysis of variance (ANOVA), direct logistic regression, and standard multiple regression. From the results of the study, only about one-third of the women (31.8%) reported they expect to get the full amount of Social Security retirement income that today's retirees get. However, around 60% of the women only save less than $25,000 or none in employer-provided retirement accounts or in personal investments and savings. There is an un-addressed gap between the cognition of the need to save for retirement and real saving action. A regular retirement saver is more likely to save more in employer-provided retirement accounts and to feel more satisfied with that retirement income. Yet, regular retirement savers have less savings in personal investments and savings, possibly because they believe their work investments will be sufficient or some women may make direct deposits to meet the annual limits of retirement plans. Other researchers have not reported this relationship. Those women who are more cognitively involved with saving for retirement are more likely to calculate needed retirement savings and to be a retirement saver, but they are less satisfied with retirement income from Social Security and from personal investments and savings. Satisfaction level is subjective; thus, those who expect to own more types of assets in retirement may have a higher satisfaction level with the expected income from both employer-sponsored retirement accounts and personal investments and savings. Generally, greater satisfaction with expected retirement income is associated with higher accumulation in retirement savings, and the female savers have much more retirement savings than non-savers. However, there is no difference in the retirement income satisfaction of savers and non-savers. These findings have implications for financial educators, counselors and advisors, researchers, employers, and policy makers. There are recommendations for women and future research. / Ph. D.
428

The sustainability of domestic budget deficits in open economies

Langdana, Farrokh K. January 1987 (has links)
This paper presents a framework for exploring the sustainability of U.S. domestic budget deficits in the presence of the currently experienced capital inflows. A 'sustainable' deficit-financing policy is defined as one in which the combination of debt-financing and seigniorage precludes the creation of a large unanticipated inflation to wipe out the debt in real terms. The model implemented is a rational expectations model of the open economy and two separate cases are analyzed. In Case I, domestic money creation is held 'fixed' and any increases in the deficit are financed by the sale of one-year discounted government bonds to domestic and foreign residents. In Case II domestic money and bonds are both endogenously determined. The asset market, in both the cases, is characterized by perfect capital mobility as defined by uncovered nominal interest parity. Real interest parity, however, does not exist as domestic and foreign goods are not perfect substitutes. In Case I, the solution of the domestic price level exhibits price-neutrality with respect to the deficits. The nominal and real exchange rates, however, are found to appreciate with increases in deficits and the situation is aggravated further by an exodus of domestic real wealth. In Case II, on the other hand, deficits are found to be inflationary and both nominal and real exchange rates depreciate with increases in the deficit. Furthermore, increases in the amount of debt being rolled over cause even greater upward pressures on domestic inflation and result in the further weakening of the dollar. The solutions also provide us with an expression for the maximum amount of debt that can be rolled over without causing the domestic price level to explode or the currency to collapse. This 'critical value' of debt is found to bear an inverse relationship to the rate of growth of the domestic deficit. Bond-financed deficits are therefore non-sustainable in both the cases discussed, and the arithmetic, it seems, is unpleasant indeed. / Ph. D.
429

Mobile-cloud assisted video summarization framework for efficient management of remote sensing data generated by wireless capsule sensors

Mehmood, Irfan, Sajjad, M., Baik, S.W. 18 July 2019 (has links)
Yes / Wireless capsule endoscopy (WCE) has great advantages over traditional endoscopy because it is portable and easy to use, especially in remote monitoring health-services. However, during the WCE process, the large amount of captured video data demands a significant deal of computation to analyze and retrieve informative video frames. In order to facilitate efficient WCE data collection and browsing task, we present a resource- and bandwidth-aware WCE video summarization framework that extracts the representative keyframes of the WCE video contents by removing redundant and non-informative frames. For redundancy elimination, we use Jeffrey-divergence between color histograms and inter-frame Boolean series-based correlation of color channels. To remove non-informative frames, multi-fractal texture features are extracted to assist the classification using an ensemble-based classifier. Owing to the limited WCE resources, it is impossible for the WCE system to perform computationally intensive video summarization tasks. To resolve computational challenges, mobile-cloud architecture is incorporated, which provides resizable computing capacities by adaptively offloading video summarization tasks between the client and the cloud server. The qualitative and quantitative results are encouraging and show that the proposed framework saves information transmission cost and bandwidth, as well as the valuable time of data analysts in browsing remote sensing data. / Supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2013R1A1A2012904).
430

Significant energy saving in industrial natural draught furnace: A model-based investigation

Karem, S., Al-Obaidi, Mudhar A.A.R., Alsadaie, S., John, Yakubu M., Mujtaba, Iqbal 28 March 2022 (has links)
Yes / In all industrial petrochemical plants and refineries, the furnace is the source of heat resulting from fuel combustion with air. The model-based furnace simulation is considered one of the efficient methods help to reduce the energy loss and maintain fixed refinery revenues, conserving energy, and finally reducing external fuel consumption and total fuel cost. In this paper, a model-based simulation is carried out for a natural air draught industrial scale furnace related to Liquified Petroleum Gas (LPG) production plant in Libya to thoroughly investigate the most responsible factors in lowering the furnace butane exit temperature, which is supposed to be two degrees Fahrenheit higher than inlet temperature. Therefore, to resolve this industrial problem, Aspen Hysys V10, coupling with EDR (exchanger design and rating) is used to carry out rigorous model-based simulation. This is specifically used to assess the impact of heat loss from inside the firebox to the surrounding medium and heat loss from the furnace stack and walls, besides the effect of excess air on the furnace efficiency. Furthermore, this research intends to verify whether the operating conditions, such as furnace tubes inlet flow rate, temperature and pumping pressure, are conforming to the upstream process design specifications or need to be adjusted. The results confirm that increasing furnace outlet temperature two degrees Fahrenheit from off specification 190 °F instead of 184 °F is successfully achieved by decreasing upstream stream flowrate 25% below the operating value and cutback excess air gradually until 20%. Also, the results clarify the necessity of increasing the flue gas temperature by 7% over design condition, to gain a significant reduction of heat loss of 31.6% and reach as low as 35.5 MBtu/hr. This improvement is achieved using optimum operating conditions of an excess air of 20%, and flue gas oxygen content of 3.3% delivered to stack. Accordingly, the furnace efficiency has been increased by 18% to hit 58.9%. Furthermore, the heat loss from the furnace walls can be also reduced by 68% from 5.41 MBtu/hr to 1.7 MBtu/hr by increasing the refractory wall thickness to 6 in., which entails an increase in the furnace efficiency by 3.66% to reach 58.96%. Decreasing the heat loss fraction through the refractory wall, pip doors, expansion windows and refractory hair cracks would also increase the efficiency by 21% to reach a high of 59.7%. Accordingly, a significant reduction in daily fuel consumption is observed, which costs 1.7 M$ per year. The outcomes of this research clearly show the potential of reducing the operation and maintenance costs significantly.

Page generated in 0.0781 seconds