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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.
41

OEE IMPROVEMENT USING COST EFFECTIVE RAW MATERIAL INVENTORY MANAGEMENT : A CASE STUDY

YAZICI, Almila Berfin January 2012 (has links)
The companies ought to care about OEE because it is a measure that shows the effect of the performance and quality related losses on the system or equipment. In order to improve OEE, they focus on defining the losses under each OEE elements and try to eliminate these losses.This study aims to enhance raw material inventory management in order to eliminateinventory management related losses and improve OEE.  Lack of raw material and improperstorage of raw material are main problems related to inventory management. A model isdeveloped and tested in order to prevent these problems and eliminate these losses.Performance rate can be improved by preventing idle time due to lack of raw material, andquality rate can be improved by standardization and improving raw material storageprocedure. In the result of model testing, it is shown that raw material inventory managementhas an effect on OEE and OEE can be improved by enhancing raw material inventorymanagement.
42

Development of techniques for in-situ measurement of heat and mass transfer in ammonia-water absorption systems

Lee, Sangsoo 10 July 2007 (has links)
An experimental investigation of heat and mass transfer in a horizontal tube falling-film ammonia-water absorber was conducted. A tube bank consisting of four columns of six 9.5 mm (3/8 ) nominal OD, 0.292 m (11.5 ) long tubes was installed in an absorber shell that allowed heat and mass transfer measurements and optical access. A test facility consisting of all the components of a functional absorption chiller was fabricated specifically for this investigation. Several variations of the basic system set up were fabricated to enable testing over the wide range of conditions (nominally, desorber solution outlet concentrations of 5 - 40% for three nominal absorber pressures of 150, 345 and 500 kPa, over solution flow rates of 0.019 0.034 kg/s.) Measurements at the absorber were used to determine heat transfer rates, overall thermal conductances, solution-side heat and vapor-side mass transfer coefficients for each test condition. For the range of experiments conducted, the solution heat transfer coefficient varied from 923 to 2857 W/m2-K while the vapor mass transfer coefficient varied from 0.0026 to 0.25 m/s and the liquid mass transfer coefficient varied from 5.51×10-6 to 3.31×10-5 m/s depending on the test condition. The solution heat transfer coefficient increased with increasing solution flow rate; however, the vapor and liquid mass transfer coefficients seem to remain unaffected with the variations in solution flow rate and were found to be primarily determined by the vapor and solution properties. The experimental heat and mass transfer coefficients were compared with the relevant studies from the literature. Based on the observed trends, heat transfer correlations and mass transfer correlations in the vapor and liquid phases were developed to predict heat and mass transfer coefficients for the range of experimental conditions tested. These correlations can be used to design horizontal tube falling-film absorbers for ammonia-water absorption systems.
43

An Analysis of Corporate Real Estate Strategies to the Return and Risk of Shareholders: Taiwan¡¦s Case

Cho, Sheng-En 07 July 2011 (has links)
This study examines whether different corporate real estate (CRE) strategies affect the stock outperformance and systemic risk of various companies. The sample of 443 listed companies of 17 industries in Taiwan during 2000 to 2010 was divided into four groups for the different corporate real estate strategies. The pairwise abnormal return and systemic risk of composite and business (without the affect from real estate market) series were empirically examined and compared using a partial adjustment model. This study also conducts the two-stage least squares procedure to determine whether four CRE strategies were considered diversifiable factors when evaluating the firm¡¦s value The results do not indicate an increasingly abnormal return performance associated with the company implementing a certain CRE strategy, but companies with a stable profession and consistent adjustment strategies are considered a good diversifier by stock investors. Aggressive adjustment strategies do not diversify the systematic risk to overall industry, otherwise the scale of total assets would be considered a diversification in companies with aggressive strategies. The companies using an aggressive profession strategy to increase leverage are regarded as risky phenomen for stock investors, and companies with stable profession strategies face higher systemic risk if their book value is greater than their market value. Therefore, this study determines that CRE strategies affect companies¡¦ systematical risk.
44

Comparison of Basic Fly Trainings: The Air Threat Introduced by People¡¦s Liberation Army to Our National Defense

Liu, Wen-shiang 19 July 2005 (has links)
After the end of Cold War, the US has involved in several battles such as two Golf Wars, Afghanistan War, and Kosovo War. With the integration of C4ISR system, the model of existing war has been redefined and changed from the traditional type of ¡§force to force¡¨ to the new type of ¡§hide and seek.¡¨ To integrate the new generation of technology in war has become the main objective of each national department of defense in the world. However if we take the lessons of war which mentioned above and think in the opposite direction from the classical theory of war, the basics of high military performance of the US force are not concluded only by the enhancement of high tech weapons. What else are the key issues which influence the consequence of war? Even the human society has evolved into the age of globalization and information. During the progress of economic integration between two sides of Taiwan Strait, the growing interactivity of economy does not have flow-out effect on the politics. Moreover the conflicts between two political powers become more and more apparent. Political conflicts also turn this area into the powder magazine of war in the world. The overall strength of China, the only imagined adversary of our country, has leapt forward since public revolution in 1978. For years, economic revolution has pushed the pace of China¡¦s military modernization faster and faster. For example, People¡¦s Republic Army has taken a great leap on the training exercise with the expansion of military exchange and with the equipment of new Soviet aircrafts. This new trend is taking away the advantage of quality of our Air Force. This brief takes the new trend in consideration and researches from the perspective of military operation. Questions are obtained from the basic fly training, the cornerstone of Air Force foundation. Taking the well-known strong force of US for example, this brief tries to realize the nature of Air Force through researching the ability of military personnel and to compare the difference of Air Force on basic fly training with other modern countries. The main objective of this brief tries to establish the basics of research and thesis using the research model concerning about subjects of constructing national defense. This brief uses the methods of analysis and comparison together to increase the precision of research theory as well. Even with the restrictions of flexibility and sampling, the first conclusion still shows there is no large difference on basic fly training between R.O.C and US. Cadets finished basic trainings have different fly abilities in R.O.C and US. The leading factors which conclude this difference are not only the training resources and environment but also the enforcement of training and the control of standards in US. Therefore, even the modernization of weapon gets faster and faster, the national force still has the great responsibility of defending national security. Bedsides expending more on military purchase, finding a way to strengthen the basic training which benefits the overall military power is not the one we can throw away.
45

A study between Trust, Delegation and job satisfaction

Han, Nien-Chia 29 January 2007 (has links)
The effectiveness of manager¡¦s management leadership is potentially affected by the interpersonal interactions with and delegation to its employees. At the same time, the level of employee job satisfaction is also affected by such relationships. How much trust does a supervisor has in this subordinate? What level of delegation is exercised by supervisors? In a business organization, what kinds of relationships exist between supervisor¡¦s trust in employees, delegation to employees and employee job satisfaction? When a supervisor¡¦s trust in and delegation to employees are met with employee with orientation toward theory X, or theory Y, what kinds of relationships exist for internal and external job satisfaction? Two sets of samples were collected in this study. One set of data were collected from a group of Taiwanese employee, the other set from a group of Chinese employee employed by Taiwanese business enterprises in the Gungdong district of China. The results of the two groups in different geographic regions were compared. Differences in trust, delegation and employee job satisfaction in the two groups with similar Chinese culture were identified. The research findings are as follows: 1. Trust and delegation are moderately and positively correlated. In this relationship, the Taiwanese employee group exhibits no significant difference with the Chinese employee group.¡@The correlation for this relationship was not highly correlated in for both employee groups. 2. Trust and employee overall job satisfaction showed moderate positive relationship. The results indicate that the Chinese employee group exhibit higher level of job satisfaction relative to the Taiwanese employee group in respect of trust. In the Taiwanese employee group, there was no significant difference between internal and external job satisfaction. But in the Chinese employee group, internal job satisfaction was higher than external job satisfaction with respect to trust. 3. In the sample of Chinese employee studied, there was no employee with theory X orientation. In the Taiwanese employee group, when theory X and Y was introduced as a factor moderating the relationship between trust and internal job satisfaction, employee with theory Y orientation showed higher level of internal job satisfaction with respect to trust than employee with theory X orientation. For both groups of employee with theory Y orientation, the Chinese employee group showed higher level of internal job satisfaction than the Taiwanese employee group. 4. Delegation and overall job satisfaction showed moderate level of positive relationship. There was no difference between the Taiwanese and Chinese employee group. 5. The relationship between delegation and internal and external job satisfaction was moderated by theory X and Y orientation. In this study, the Chinese employee group has no employee with theory X orientation. In the Taiwanese employee group, employee with theory Y orientation exhibit higher level of correlation between delegation and internal job satisfaction than employee with theory X orientation. In both groups of theory Y orientation, there was no significant difference between the Chinese and Taiwanese employee group with respect to internal job satisfaction. With respect to the relationship between delegation and external job satisfaction, in the Taiwanese employee group, the correlation between delegation and external job satisfaction for employee with theory Y orientation was much higher than that for theory X. For both groups of theory Y, the internal job satisfaction in Taiwanese employee group was higher than the Chinese employee group. This study reviews the relationship between supervisor¡¦s trust and delegation with respect to subordinate¡¦s level of job satisfaction. The results serve as reference for supervisors and managers in their management or leadership. For the business managers and supervisors of Taiwanese business enterprises in China, this study has made comparison between the Taiwanese group and Chinese group, which may be beneficial in understanding the organizational behavior of local Chinese employee when considering investment in China.
46

Adiabatic and overall effectiveness in the showerhead of a film cooled turbine vane and effects of surface curvature on adiabatic effectiveness

Nathan, Marc Louis 08 February 2012 (has links)
Two sets of experiments were performed on a simulated turbine nozzle guide vane. First, adiabatic and overall effectiveness measurements were taken in the showerhead region of the vane using adiabatic and matched Biot vane models, respectively. Measurements of overall effectiveness in the showerhead region are not found in the literature, and are a useful baseline for validating the results of computational fluid dynamics (CFD) simulations. Overall effectiveness is useful because it shows the results of combining film cooling, internal convection, and surface conduction to provide a more complete picture of vane cooling than adiabatic effectiveness. An impingement plate was utilized to generate internal jet cooling. Momentum flux ratios were matched between the models and ranged from I*SH = 0.76 to 6.70, based on showerhead upstream approach velocity. The second set of experiments used a different model to examine the effects of surface curvature on adiabatic effectiveness. Results in open literature are found by varying the radius of curvature of a fixed setup, so the current approach was novel in that it looked at adiabatic effectiveness at locations of various curvature around the same vane. Blowing ratios from M = 0.4 to M = 1.6 were tested at a density ratio of DR = 1.20 for two locations on the suction side of the vane. Results were presented in terms of laterally averaged adiabatic effectiveness and contour plots of adiabatic effectiveness, and were compared to literature. / text
47

Experimental investigation of overall effectiveness and coolant jet interactions on a fully cooled C3X turbine vane

McClintic, John W 19 November 2013 (has links)
This study focused on experimentally measuring the performance of a fully cooled, scaled up C3X turbine vane. Experimental measurements focused on investigating row-to-row interactions of coolant jets and the contributions of external film cooling and internal impingement cooling to overall cooling effectiveness. Overall effectiveness was experimentally measured using a thermally scaled, matched Biot number vane model featuring a realistic internal impingement scheme and had normalized surface temperatures that were representative of those found on engine components. A geometrically identical vane was also constructed out of low conductivity polystyrene foam to measure the normalized adiabatic wall temperature, or adiabatic effectiveness of the film cooling configuration. The vanes featured a full coverage film-cooling scheme with a five-row showerhead and 13 total rows of holes containing 149 total coolant holes. This study was the first study to make highly detailed measurements of overall effectiveness on a fully-cooled vane model and expands on previous studies of adiabatic and overall effectiveness on the showerhead and single rows of holes on a matched Biot vane by considering a fully cooled configuration to determine if the results from these previous studies also hold for a fully cooled configuration. Additionally, velocity and thermal fields were measured just upstream of two different suction side rows of holes in order to study the effect of introducing upstream coolant injection. The effects of mainstream turbulence and span-wise location were examined and at the downstream row of holes, the contributions of different rows of holes to the approach flow were compared. This study was the first to measure mean and fluctuating velocity data on the suction side of a turbine vane with upstream coolant injection. Understanding the effects of how upstream injection affects the performance of downstream rows of holes is critical to understanding the film cooling performance on a fully cooled turbine airfoil. / text
48

Choosing the Right Embryo : and not accepting the principle of procreative beneficence

Muullaart, Ida January 2015 (has links)
Är det möjligt att välja rätt embryo vid In-vitro fertilisering (IVF)? I sådana fall, vad innebär det att något är det rätta embryot? I denna uppsats diskuteras IVF och de moraliska dilemman som kan uppstå vid val av embryo. Vid IVF är det möjligt att ställa en preimplantorisk genetisk diagnostik (PGD) vilken kan ge information om genetiska sjukdomar och andra anlag, såväl som kön och kromosomfel. Enligt Julian Savulescu, som förespråkar the Principle of Procreative Beneficence, är vi moraliskt skyldiga att välja ett friskt embryo, vilket också anses vara det rätta embryot. I kontrast till detta ställs Christine Overall som menar att Savulescus princip innebär problem för hur vi bör se på barnafödande. Jag diskuterar vidare hur vi utifrån ett socialt och ett samhällsperspektiv kan se det som moraliskt tveksamt att förbjuda att personer med vissa anlag föds, samt försöker visa på Savulescus ignorans för hur IVF fungerar och att detta bidrar till att hans argument fallerar.
49

Case Study: Production and OEE improvement for an 800 tons stamping press

Narses, Aurélien January 2013 (has links)
The actual industrial development linked to the financial situation over the world lead automotive and other companies to expand their production level to stay competitive. Changing an organization to raise its production or profit is not a one day journey, but requires some steps. Tools exist to develop the production level of manufacturing industry since more or less the fifties, and the continuous improvement is measured by some available and famous indicators around lean manufacturing mainly. Pressing equipment especially like a metal stamping press expressed through the following case study can be improved by respecting some fundamentals. Lean manufacturing aspects as 5 S’s and TPM (Total Productive Maintenance) for example are tools that can be applied to improve the production rate of a stamping press. To even better improve the OEE (Overall Equipment Effectiveness) of the same machine, a tool like SMED (Single Minute Exchange of Dies) reveals to be really powerful when improving the global output rate of the machine. The case study developed inside this present report aims to investigate all the possibilities to improve the OEE of pressing equipment facing theoretical aspects and reality issues. The tools involved are part of the content, but the way to support a company for the organizational change required to the success is another part of the content. Technical solutions are taking part of the outcome, and a strong link to change management is included. Correlation between both technical and managerial aspects is the main line followed to get the final results. An experimental and actual OEE is calculated, and improved following a rating according to the possible improvements. Those results are analyzed to provide a weighted feedback related to the whole research.
50

Investigation of Genomic Estimated Breeding Values and Association Methodologies using Bayesian Inference in a Nellore-Angus Crossbred Population for Two Traits

Hulsman, Lauren Lorene 16 December 2013 (has links)
The objectives of this study were to 1) evaluate marker associations for genomic regions of interest and significant ontology terms, 2) evaluate and compare 4 models for their efficacy in predicting genetic merit, 3) evaluate and compare the impact of using breed-of-origin genotypes in a Bayesian prediction model, and 4) evaluate the effects of data partitioning using family structure on predictions. Nellore-Angus F2, F3 and half-sibling calves were used with records for overall temperament at weaning (OTW; a subjective scoring system; n = 769) and Warner-Bratzler shear force (WBSF; a measure of tenderness; n = 389). After filtering, 34,913 markers were available for use. Bayesian methods employed were BayesB (using ̂) and BayesC (using π = 0 and ̂) in GenSel software, where, after estimation, π ̂ = 0.995 or 0.997 for WBSF or OTW, respectively. No regions associated with either trait were found using π ̂, but when π = 0 associated regions were identified (37 and 147 regions for OTW and WBSF, respectively). Comparison of genomic estimated breeding values from these 3 Bayesian models to an animal model showed that BayesC procedures (using ̂) had the highest accuracy for both traits, but that BayesB had the lowest indication of bias in either case. Using a subset of the population (n = 440), genotypes based on the breed in which the alleles originated from (i.e., breed-of-origin genotypes) were assigned to markers mapped to autosomes (n = 34,449), and incorporated into prediction analyses using BayesB (π ̂ = 0.997) with or without nucleotide-based genotypes. In either case, there was an increase in accuracy when breed-of-origin genotypes were incorporated into prediction analyses. Data partitions based on family structure resulted in 13 distinct training and validations groups. Relationship of individuals in the training with validation individuals did have an impact in some cases, but not all. There was poor prediction of genomic estimated breeding values for individuals in the validation population using BayesB methods, but performed better in all cases than breeding values generated using an animal model. Future studies incorporating breed-of-origin genotypes are of interest to determine if accuracy is improved in these groups.

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