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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.
51

A Prototype Software To Select And Construct Control Charts For Short Runs

Doganci, Hakan 01 October 2004 (has links) (PDF)
Small and Medium Sized Enterprises (SMEs) were founded to improve the activity and effectiveness of small industries, to provide economic and social needs of the country, to increase the competitive level of the country, and to establish integration in the industry. In today&rsquo / s competition conditions, SMEs should continuously improve themselves / otherwise, they could lose their market shares. One of the major problems encountered in Turkish SMEs is poor quality activities / especially, not being able to exploit the Statistical Process Control (SPC) techniques. Production runs become shorter and shorter, and the product variety seems to be ever increasing, which cause short production runs. Using traditional control charts for short production runs can yield wrong and costly results. Instead of traditional control charts, short run charts such as Difference Charts (DNOM), Zed Charts, and Zed-Star Charts should be preferred.For this purpose, software that not only constructs short run control charts but also implements charts by tests to solve the problems of SMEs is developed. A Control Chart Selection Wizard, which is capable of emulating human expertise in finding a suitable control chart according to the user response for different cases is developed and added as a subprogram. Software was tested at Ar&ccedil / elik Dishwasher Plant in Ankara. The overall evaluation of the developed software, as regards the user, was satisfactory. The software can meet some requirements of the SMEs.
52

Optimisation et réduction de la variabilité d’une nouvelle architecture mémoire non volatile ultra basse consommation / Optimization and reduction of the variability of a new nonvolatile memory architecture ultra-low power consumption

Agharben, El Amine 05 May 2017 (has links)
Le marché mondial des semi-conducteurs connait une croissance continue due à l'essor de l'électronique grand public et entraîne dans son sillage le marché des mémoires non volatiles. L'importance de ces produits mémoires est accentuée depuis le début des années 2000 par la mise sur le marché de produits nomades tels que les smartphones ou plus récemment les produits de l’internet des objets. De par leurs performances et leur fiabilité, la technologie Flash constitue, à l'heure actuelle, la référence en matière de mémoire non volatile. Cependant, le coût élevé des équipements en microélectronique rend impossible leur amortissement sur une génération technologique. Ceci incite l’industriel à adapter des équipements d’ancienne génération à des procédés de fabrication plus exigeants. Cette stratégie n’est pas sans conséquence sur la dispersion des caractéristiques physiques (dimension géométrique, épaisseur…) et électriques (courant, tension…) des dispositifs. Dans ce contexte, le sujet de ma thèse est d’optimiser et de réduire la variabilité d’une nouvelle architecture mémoire non volatile ultra basse consommation.Cette étude vise à poursuivre les travaux entamés par STMicroelectronics sur le développement, l’étude et la mise en œuvre de boucles de contrôle de type Run-to-Run (R2R) sur une nouvelle cellule mémoire ultra basse consommation. Afin d’assurer la mise en place d’une régulation pertinente, il est indispensable de pouvoir simuler l’influence des étapes du procédé de fabrication sur le comportement électrique des cellules en s’appuyant sur l’utilisation d’outils statistiques ainsi que sur une caractérisation électrique pointue. / The global semiconductor market is experiencing steady growth due to the development of consumer electronics and the wake of the non-volatile memory market. The importance of these memory products has been accentuated since the beginning of the 2000s by the introduction of nomadic products such as smartphones or, more recently, the Internet of things. Because of their performance and reliability, Flash technology is currently the standard for non-volatile memory. However, the high cost of microelectronic equipment makes it impossible to depreciate them on a technological generation. This encourages industry to adapt equipment from an older generation to more demanding manufacturing processes. This strategy is not without consequence on the spread of the physical characteristics (geometric dimension, thickness ...) and electrical (current, voltage ...) of the devices. In this context, the subject of my thesis is “Optimization and reduction of the variability of a new architecture ultra-low power non-volatile memory”.This study aims to continue the work begun by STMicroelectronics on the improvement, study and implementation of Run-to-Run (R2R) control loops on a new ultra-low power memory cell. In order to ensure the implementation of a relevant regulation, it is essential to be able to simulate the process manufacturing influence on the electrical behavior of the cells, using statistical tools as well as the electric characterization.
53

Dynamic Probability Control Limits for Risk-Adjusted Bernoulli Cumulative Sum Charts

Zhang, Xiang 12 December 2015 (has links)
The risk-adjusted Bernoulli cumulative sum (CUSUM) chart developed by Steiner et al. (2000) is an increasingly popular tool for monitoring clinical and surgical performance. In practice, however, use of a fixed control limit for the chart leads to quite variable in-control average run length (ARL) performance for patient populations with different risk score distributions. To overcome this problem, the simulation-based dynamic probability control limits (DPCLs) patient-by-patient for the risk-adjusted Bernoulli CUSUM charts is determined in this study. By maintaining the probability of a false alarm at a constant level conditional on no false alarm for previous observations, the risk-adjusted CUSUM charts with DPCLs have consistent in-control performance at the desired level with approximately geometrically distributed run lengths. Simulation results demonstrate that the proposed method does not rely on any information or assumptions about the patients' risk distributions. The use of DPCLs for risk-adjusted Bernoulli CUSUM charts allows each chart to be designed for the corresponding particular sequence of patients for a surgeon or hospital. The effect of estimation error on performance of risk-adjusted Bernoulli CUSUM chart with DPCLs is also examined. Our simulation results show that the in-control performance of risk-adjusted Bernoulli CUSUM chart with DPCLs is affected by the estimation error. The most influential factors are the specified desired in-control average run length, the Phase I sample size and the overall adverse event rate. However, the effect of estimation error is uniformly smaller for the risk-adjusted Bernoulli CUSUM chart with DPCLs than for the corresponding chart with a constant control limit under various realistic scenarios. In addition, there is a substantial reduction in the standard deviation of the in-control run length when DPCLs are used. Therefore, use of DPCLs has yet another advantage when designing a risk-adjusted Bernoulli CUSUM chart. These researches are results of joint work with Dr. William H. Woodall (Department of Statistics, Virginia Tech). Moreover, DPCLs are adapted to design the risk-adjusted CUSUM charts for multiresponses developed by Tang et al. (2015). It is shown that the in-control performance of the charts with DPCLs can be controlled for different patient populations because these limits are determined for each specific sequence of patients. Thus, the risk-adjusted CUSUM chart for multiresponses with DPCLs is more practical and should be applied to effectively monitor surgical performance by hospitals and healthcare practitioners. This research is a result of joint work with Dr. William H. Woodall (Department of Statistics, Virginia Tech) and Mr. Justin Loda (Department of Statistics, Virginia Tech). / Ph. D.
54

Shifting focus of the traditional centres of contemporary art : Scotland's evolving position from periphery to prominence

Jackson, Deborah January 2014 (has links)
My thesis considers the distinctive characteristics of contemporary artistic production and display in Scotland from the 1960s to the present. The main objective is to make manifest the diversification of global sites of contemporary art away from traditional centres by examining less exposed aspects of art practice in Scotland. My methodology is driven by a set of case studies of artist-run initiatives (ARIs), which provide models of enquiry into alternative methods of production and display of contemporary art and that demonstrate the role of ARIs in producing art scenes, and not merely representing those that already exist. I focus on counter-histories of self-organised ARIs and their legacies, and adopt a genealogical approach to examine how recent praxis and infrastructures came into existence and how their initial impetus intersected with their historical conditions. Anthony Giddens’ structuration theory is employed to examine local forms of power and infrastructure, as well as the wider, global structures of the art world. The emphasis is on how ARIs and established institutions can and do negotiate with each other and in recognising the interpenetration of different scales of art institutions. I apply a bifurcated approach in order to bring Scotland into dialogue with anthropological discussions of cultural globalisation. I ask how locality, nationalism and globalisation are configured in (visual) culture generally and as applied specifically to a Scottish context. This is underpinned by a consideration of Scottish Devolution as a disintegration of hierarchical domination, which correlates to the ideologies of artist-run practice. Finally, I propose the eradication of top-down delivery in favour of horizontal distributions of knowledge and practice via self-organisation.
55

Structural analysis of energy market failure : empirical evidence from US

Hosseini Tabaghdehi, Seyedeh Asieh January 2013 (has links)
This thesis is concerned with the econometric modelling of gasoline prices in US. The intention is to characterize the market process in this crucial and significant industry. Overall we have been seeking to identify a mechanism to signal and measure market failure and consequently improve market performance. Firstly we examine the time series properties of gasoline prices using the criteria for perfect arbitrage to test market efficiency from the stationarity of price proportions. This is done by considering market efficiency across in different regions of the US, by applying a range of different stationary tests. In this analysis we collected a comprehensive data set of gasoline prices for all regions of the US mainland for the longest period available. Forni (2004), outlined reasons why the analysis of price proportions may be advantageous; especially when the sample is limited. Stationarity corresponds to a broad market, it is found here that the US gasoline market is on average broad. Except for the Gulf Coast and Lower Atlantic, which may be seen as economically and/or geographically separated, market structure in the rest of the US would not appear to be a problem Next we investigate possible long-run price leadership in the US gasoline market and the inter-relatedness of price behaviour relevant to a competitive market. Following Hunter & Burke (2007) and Kurita (2008) market definition is tested. This is done on an extended regional data set to Kurita and following the analysis in Hunter and Burke on a set of company data for the US.We analysed long-run price leadership through the cointegrated vector auto-regression (VAR) to identify key characteristics of long-run structure in the gasoline market. The analysis of the system of regional prices confirms problems with the Gulf Coast and Lower Atlantic, but also based on the finding that the cointegrating rank is less than N-1 using both types of data ( regional price data and company price data) and the findings on weak exogenity it is suggested that competition across the whole of the US is further limited. We applied further tests to company data on prices and quantity data to investigate further the need to regulate for potential anomalies and to capture more directly consumer harm. The variance screening method applied to recent weekly data indicates that there is too little variation in gasoline prices and this would seem to support the cointegration study. Furthermore we applied a dynamic disequilibrium analysis to attempt to identify long-run demand and supply in the gasoline market. Finding significant variables using the Phillips-Hansen fully modified estimation of the switching regression is necessary to distinguish two long-run equations (S&D). Moreover a comparison is made with a Markov Switching Model (MSM) of prices and this suggests a similar pattern of regime to the quantity information analysed in by our disequilibrium model.
56

Essays on technological progress and economic growth

Growiec, Jakub 24 October 2007 (has links)
This thesis covers a broad range of topics in the general area of economic growth theory and economics of technological change. It is primarily about the ultimate sources of growth and its ultimate limitations. We scrutinize the implications of several specifications of long-run growth "engines" which can be found across the theoretical literature and put forward their generalizations and extensions. At the highest level of generality, we provide a formal proof that balanced (i.e. exponential) growth requires knife-edge assumptions which cannot be satisfied by typical values of model parameters. This result implies that at least one such knife-edge assumption must be made if a given model is supposed to deliver balanced growth over the long run. Next, we deal with the issue of resource-based limits to long-run growth. We propose to promote technological progress which would improve the substitutability between non-renewable and renewable resources: if the elasticity of substitution between the two kinds of resources exceeds unity, production will not fall down to zero even after the non-renewable resources will have been completely depleted. Factor-augmenting technological progress can also be helpful, but its effects are much less pronounced and it must go on forever in order to assure sustainable production. Another question asked is whether it is plausible that R&D-based growth, fueled by steady increases in the world’s population, can be extended into indefinite time. We answer this question by introducing endogenous fertility choice, with population entering the utility functional multiplicatively, into an R&D-based semi-endogenous growth model. The next issue addressed here are the idea-based microfoundations of aggregate production functions. We discuss the correspondence between the shape of production functions, the direction of technical change, and the possibility of sustained endogenous growth. A broad class of production functions, nesting both the Cobb-Douglas and the CES function, is derived. Finally, we discuss the impact of the heterogeneity of innovations on long-run economic dynamics: we extend the semi-endogenous growth model with a distinction between radical and incremental innovations. Total R&D output is assumed to depend on technological opportunity which is depleted by incremental innovations but renewed by radical innovations. The dynamic interplay of the arrivals of the two types of innovations is shown to give rise to oscillations along the transition to the economy’s balanced growth path.
57

Contaminant Transfer in a Run-Around Membrane Energy Exchanger

2012 December 1900 (has links)
Volatile Organic Compounds (VOCs) constitute an important class of indoor air contaminants and they may cause adverse health effects for occupants in buildings. Indoor generated contaminants may be transferred between the supply and exhaust air streams of the building’s Heating, Ventilation and Air-conditioning (HVAC) system when air-to-air energy recovery devices are used. The run-around membrane energy exchanger (RAMEE) is a novel exchanger, which uses aqueous magnesium chloride (MgCl2) salt solution (34-35 wt%) as a liquid desiccant to transfer heat and moisture between remote supply and exhaust air streams. In the RAMEE, a gas-phase porous membrane is placed between the air stream and the liquid desiccant stream in each exchanger and the membrane prevents the salt solution from entering the air stream but still allows the transfer of water vapor through the semi-permeable membrane. In the RAMEE, VOCs may transfer between the exhaust and supply air streams due to (i) air leakage or (ii) due to dissolution of VOCs into the liquid desiccant in the exhaust exchanger and their subsequent evaporation into the air stream of the supply exchanger. These two transfer mechanisms were tested in the laboratory using two counter-cross-flow RAMEE prototypes (Prototype #4 and Prototype #6). Tests were conducted at different air and desiccant flow rates at AHRI standard summer and winter operating conditions. Sulfur hexafluoride (SF6) was used as a tracer gas to test air leakage and toluene (C7H8) and formaldehyde (HCHO) were used to test VOC dissolution and transfer. From an external source, a known concentration of VOC was injected into the exhaust air inlet stream and the transfer fraction of VOC to the supply air stream was calculated. This transfer fraction or Exhaust Air Transfer Ratio (EATR) defined by ANSI/ASHRAE Standard 84 (2012) at steady state conditions was used to quantify and compare the transfer fraction of contaminants in both prototypes. The uncertainty in the transfer fraction was calculated and all the uncertainty bounds were calculated for 95% confidence interval. The transfer fraction of sulfur hexafluoride was 0.02 +/- 3.6% for both prototypes tested, which means that the air leakage between the air streams is negligible. The transfer of toluene, which has a low solubility in water, was less than the uncertainty in the measurement. EATR* values for toluene were 2.3-3.4% and the uncertainties were 3.4-3.6%. The transfer of formaldehyde between the exhaust and the supply air streams was the highest and the EATR* values just exceeded the uncertainties in the EATR* measurement. The highest EATR* values for the transfer of formaldehyde in Prototype #4 and Prototype #6 were 6.4 +/- 3.6% and 5.3 +/- 3.6%, respectively. At steady state, the measured EATR* values for both prototypes were insensitive to changes in the air flow rate, the liquid desiccant flow rate, the latent effectiveness and the environmental conditions but time delays to reach steady state were significant. These results imply that there is a negligible transfer of contaminants due to air leakage between the air streams, a negligible transfer of low water soluble VOCs (such as toluene), but possibly a small detectable transfer of very water soluble VOCs (such as formaldehyde) between the exhaust and supply air streams of the RAMEE.
58

Effect of CNC axis movement on the surface roughness in milling

Liu, Yuan January 2015 (has links)
In this paper, the performance of a new measurement system CITE (CNC Integrity Tracing Equipment) is investigated. CITE measurement system is the name given to the data acquisition hardware and software developed by University West for recording the movements of CNC machine tools. It can be used for monitoring of the milling process and recording the milling errors. The aim of this study is investigate the capability of the CITE system in prediction of the surface roughness. In an example cutting test, the CITE measurement system was used for recording selected sections in straight milling process and curved milling process. After that, surface roughness, predicted by the CITE measurement system, was compared with the CMM (Coordinate measurement machine). The investigation shows that the CITE measurement system is comparable to the CMM for evaluation of roughness in curved sections. In straight sections, the evaluation of roughness by CMM machine is close to the simulation values that predicts surface roughness considering tool run-out.
59

Vliv běhu se zátěží na posturální stabilitu / The effect of running a load on postural stability

Kellner, Petr January 2015 (has links)
1 Abstract Title: The effect of running with a load on postural stability. Objectives: The establishment of changes in postural stability after a 3 km maximum effort run with a 15 kg load. Research sample: The tested subject group was constitued by seven soldiers of the Army of The Czech Republic at the average age of 25,6 ± 2,1 years who are students of the Military specialization at the Faculty of sport and physical education of The Charles University. Methods: This master's thesis was drawn up as a observational study of theoretic empiric character, realised through intraindividual comparative analysis on a group of 7 subjects. Postural stability was examined with RS Footscan forceplate and clinical balance test U.S. Military Academy Stance Test. The run was realised on a treadmill, without and with a load. For statistical analysis nonparametric statistic tests of significance were used. Results: The results of relations between postural control changes and 3km run with a load of 15 kg display a deterioration of postural stability tested after the run. The extend of deterioration of postural stability after 3-km run with a load within tested group is similar to one after 3-km run of analogous intensity. Key words: run, load, postural stability, balance
60

Závislost výkonů ve vybraných atletických disciplínách žáků druhého stupně ZŠ / Dependence of performance in selected athletic disciplines students in second level primary schools

Vopršálek, Radek January 2016 (has links)
NAME: Determine the dependence of performance in selected athletic disciplines students in primary schools AUTHOR: Radek Vopršálek DEPARTMENT: Katedra tělesné výchovy SUPERVISOR: PhDr. PaedDr. Ladislav Kašpar, Ph.D. ABSTRACT: The aim of this thesis is to explore the relationship and dependency between performances in chosen sports disciplines for pupils of primary school. The disciplines I have chosen to determine the relative performance are: long jump and 60 meters sprint. In the theoretical part there is a description and analysis of these sports disciplines. In the practical part there is a measurement of pupils' performances in that two sports disciplines and creating a dependency relationship between them. KEYWORDS: Long jump, Bounce, Run, Relationship.

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