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Sound Quality Evaluation of HVAC&R EquipmentWeonchan Sung (9188837) 04 August 2020 (has links)
Characteristics of heating, ventilation, air conditioning and refrigeration (HVAC&R) equipment sounds and people's responses to them were studied in order to develop models to predict annoyance from recordings of the sound. These models are intended to address shortcomings of currently used methods for HVAC&R product sound assessment. Coupled with sound prediction models, the annoyance models will be used to monitor and guide improvements to HVAC&R equipment sound quality throughout the product design process: from virtual early design, through to the prototyping and product refinement stages. Responses to residential and refrigerated truck product noise was studied; both produce broadband random noise and families of harmonics related to rotating and reciprocating components within the system. Tests were conducted to determine how people describe HVAC&R equipment sounds; how their descriptions relate to sound characteristics and overall assessments; and to develop models that relate predicted strengths of sound characteristics to the overall assessment. Annoyance models were developed for each types of product. Loudness and spectral balance metrics are included in models for both types of product. Inclusion of a tonalness metric improved models for residential units, and roughness and impulsiveness metrics improved models for refrigerated truck units. The models developed were used to predict responses in the other tests and there was good agreement between predicted and measured responses. An illustration of the use of the annoyance models, in conjunction with sound visualization and signal modification techniques, to guide improvements to product sound quality is given.
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Oil Management in Systems Running Vapor Compression CycleVatsal M Shah (11155080) 24 July 2021 (has links)
<p>Most air conditioning and refrigeration systems that employ the vapor compression cycle rely on oil circulating with refrigerant to lubricate the bearings and other contact surfaces in the compressor. The lubricant acts as a sealant to reduce leakage losses during the compression process and it also helps to absorb some of the excess heat that is generated in the compression chamber. However, this oil circulation results in oil retention in various other components outside the compressor depending on the physical interaction between lubricant and refrigerant and their transport properties. Other factors, such as the geometry and orientation of connecting lines, and the system operating conditions, such as refrigerant flow rate and oil circulation ratio, also impact the oil retention. Because of oil retention, the oil level in the compressor reduces, which may ultimately affect its efficiency and life span. In addition, the effectiveness of heat exchangers (evaporators and condensers) decreases. The current line sizing rules reported in the ASHRAE Handbook on Refrigeration have only limited consideration of the effects of oil in the system. With the increasing development of variable-speed systems as well as future use of newer HFO refrigerants, there is a need in the industry for upgrading the line sizing recommendations, especially the connecting gas lines of unitary split systems, which consider the effects of oil retention. To develop these rules, measuring oil retention at different operating conditions is important. A test setup has been built to measure oil retention in horizontal and vertical lines of different diameters at different refrigerant and oil flow conditions. Based on the collected data, a physics-based semi-empirical model is developed which can predict oil retention in gas lines for some of the commonly used refrigerant-lubricant combinations in the HVAC&R industry.</p><p>Oil Circulation Ratio (OCR) is one of the input parameters to the model which predicts oil retention. A non-invasive, in-situ method to measure OCR in real time, which involves minimal human intervention, is developed. This method is based on oil separation and is implemented on the suction line. The approach has been validated with two different methods, one of which is an ASHRAE standard. The results of the study offer clear evidence that the method is as accurate as a standard method and it involves less human intervention as the measurement process is automated.</p>
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Var arbetar den kvinnliga kocken?Lindqvist, Anders January 2008 (has links)
Som utbildad kock och flitig besökare på restauranger av utvald kvalité, tycker jag mig se att det är en övervägande majoritet av män som huserar i våra restaurangkök. Syftet med denna fallstudie var att ta reda på vad de kvinnor som utbildat sig för ett arbete inom restaurangbranschen arbetar med sju år efter avslutad gymnasieutbildning. Jag använde mig av personliga, bandade intervjuer med sex slumpvis utvalda kvinnor från avgångsklasserna på HR-programmet år 2000. Med detta ville jag ta reda på: vad, var och varför de arbetar med det de gör just nu. Sammanfattningsvis visade resultatet av min fallstudie att ingen av de intervjuade kvinnorna arbetar som kock i ett restaurang-varmkök. Resultatet av denna begränsade undersökning antyder även att deras val är genusrelaterad.
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Engaging asylum seeking and refugee (AS&R) women in midwifery educationHaith-Cooper, Melanie, McCarthy, Rose January 2015 (has links)
Yes
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Hodnocení kvality pneumatických lineárních pohonů / Quality assessment of pneumatic linear drivesPecl, Tomáš January 2015 (has links)
This Master’s thesis deals with the evaluation of quality pneumatic linear drives. The theoretical part describes the problems in the field of pneumatic cylinders and statistical methods to perform the analysis. The practical part includes the execution and evaluation of the statistical analysis of the measurement process and pneumatic cylinders, also brings recommendations to optimize the measurement process. The methods used included analysis Gage R & R, Analysis control charts and data analysis using the process capability. The study was made for the purpose of improving test equipment Norgren Ltd. Used computer programs was Minitab Statistical Software and MS Excel.
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A study of the Jean.January 1984 (has links)
fashion industry in Hong Kong : a case study : Sparkle / by Choi Hung Wai, Ricky. / Bibliography : leaves [43] - 44 / Thesis (M.B.A.)--Chinese University of Hong Kong, 1984
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Análise de dados funcionais aplicada ao estudo de repetitividade e reprodutividade : ANOVA das distânciasPedott, Alexandre Homsi January 2010 (has links)
Esta dissertação apresenta um método adaptado do estudo de repetitividade e reprodutibilidade para analisar a capacidade e o desempenho de sistemas de medição, no contexto da análise de dados funcionais. Dado funcional é a variável de resposta dada por uma coleção de dados que formam um perfil ou uma curva. O método adaptado contribui para o avanço do estado da arte sobre a análise de sistemas de medição. O método proposto é uma alternativa ao uso de métodos tradicionais de análise, que usados de forma equivocada, podem deteriorar a qualidade dos produtos monitorados através de variáveis de resposta funcionais. O método proposto envolve a adaptação de testes de hipótese e da análise de variância de um e dois fatores usados em comparações de populações, na avaliação de sistemas de medições. A proposta de adaptação foi baseada na utilização de distâncias entre curvas. Foi usada a Distância de Hausdorff como uma medida de proximidade entre as curvas. A adaptação proposta à análise de variância foi composta de três abordagens. Os métodos adaptados foram aplicados a um estudo simulado de repetitividade e reprodutibilidade. O estudo foi estruturado para analisar cenários em que o sistema de medição foi aprovado e reprovado. O método proposto foi denominado de ANOVA das Distâncias. / This work presents a method to analyze a measurement system's performance in a functional data analysis context, based on repeatability and reproducibility studies. Functional data are a collection of data points organized as a profile or curve. The proposed method contributes to the state of the art on measurement system analysis. The method is an alternative to traditional methods often used mistakenly, leading to deterioration in the quality of products monitored through functional responses. In the proposed method we adapt hypothesis tests and one-way and two-way ANOVA to be used in measurement system analysis. The method is grounded on the use of distances between curves. For that matter the Hausdorff distance was chosen as a measure of proximity between curves. Three ANOVA approaches were proposed and applied in a simulated repeatability and reproducibility study. The study was structured to analyze scenarios in which the measurement system was approved or rejected. The proposed method was named ANOVA of the distances.
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Análise de dados funcionais aplicada ao estudo de repetitividade e reprodutividade : ANOVA das distânciasPedott, Alexandre Homsi January 2010 (has links)
Esta dissertação apresenta um método adaptado do estudo de repetitividade e reprodutibilidade para analisar a capacidade e o desempenho de sistemas de medição, no contexto da análise de dados funcionais. Dado funcional é a variável de resposta dada por uma coleção de dados que formam um perfil ou uma curva. O método adaptado contribui para o avanço do estado da arte sobre a análise de sistemas de medição. O método proposto é uma alternativa ao uso de métodos tradicionais de análise, que usados de forma equivocada, podem deteriorar a qualidade dos produtos monitorados através de variáveis de resposta funcionais. O método proposto envolve a adaptação de testes de hipótese e da análise de variância de um e dois fatores usados em comparações de populações, na avaliação de sistemas de medições. A proposta de adaptação foi baseada na utilização de distâncias entre curvas. Foi usada a Distância de Hausdorff como uma medida de proximidade entre as curvas. A adaptação proposta à análise de variância foi composta de três abordagens. Os métodos adaptados foram aplicados a um estudo simulado de repetitividade e reprodutibilidade. O estudo foi estruturado para analisar cenários em que o sistema de medição foi aprovado e reprovado. O método proposto foi denominado de ANOVA das Distâncias. / This work presents a method to analyze a measurement system's performance in a functional data analysis context, based on repeatability and reproducibility studies. Functional data are a collection of data points organized as a profile or curve. The proposed method contributes to the state of the art on measurement system analysis. The method is an alternative to traditional methods often used mistakenly, leading to deterioration in the quality of products monitored through functional responses. In the proposed method we adapt hypothesis tests and one-way and two-way ANOVA to be used in measurement system analysis. The method is grounded on the use of distances between curves. For that matter the Hausdorff distance was chosen as a measure of proximity between curves. Three ANOVA approaches were proposed and applied in a simulated repeatability and reproducibility study. The study was structured to analyze scenarios in which the measurement system was approved or rejected. The proposed method was named ANOVA of the distances.
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Análise de dados funcionais aplicada ao estudo de repetitividade e reprodutividade : ANOVA das distânciasPedott, Alexandre Homsi January 2010 (has links)
Esta dissertação apresenta um método adaptado do estudo de repetitividade e reprodutibilidade para analisar a capacidade e o desempenho de sistemas de medição, no contexto da análise de dados funcionais. Dado funcional é a variável de resposta dada por uma coleção de dados que formam um perfil ou uma curva. O método adaptado contribui para o avanço do estado da arte sobre a análise de sistemas de medição. O método proposto é uma alternativa ao uso de métodos tradicionais de análise, que usados de forma equivocada, podem deteriorar a qualidade dos produtos monitorados através de variáveis de resposta funcionais. O método proposto envolve a adaptação de testes de hipótese e da análise de variância de um e dois fatores usados em comparações de populações, na avaliação de sistemas de medições. A proposta de adaptação foi baseada na utilização de distâncias entre curvas. Foi usada a Distância de Hausdorff como uma medida de proximidade entre as curvas. A adaptação proposta à análise de variância foi composta de três abordagens. Os métodos adaptados foram aplicados a um estudo simulado de repetitividade e reprodutibilidade. O estudo foi estruturado para analisar cenários em que o sistema de medição foi aprovado e reprovado. O método proposto foi denominado de ANOVA das Distâncias. / This work presents a method to analyze a measurement system's performance in a functional data analysis context, based on repeatability and reproducibility studies. Functional data are a collection of data points organized as a profile or curve. The proposed method contributes to the state of the art on measurement system analysis. The method is an alternative to traditional methods often used mistakenly, leading to deterioration in the quality of products monitored through functional responses. In the proposed method we adapt hypothesis tests and one-way and two-way ANOVA to be used in measurement system analysis. The method is grounded on the use of distances between curves. For that matter the Hausdorff distance was chosen as a measure of proximity between curves. Three ANOVA approaches were proposed and applied in a simulated repeatability and reproducibility study. The study was structured to analyze scenarios in which the measurement system was approved or rejected. The proposed method was named ANOVA of the distances.
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Measurement Systems Analysis Studies: A Look at the Partition of Variation (POV) MethodJanuary 2015 (has links)
abstract: The Partition of Variance (POV) method is a simplistic way to identify large sources of variation in manufacturing systems. This method identifies the variance by estimating the variance of the means (between variance) and the means of the variance (within variance). The project shows that the method correctly identifies the variance source when compared to the ANOVA method. Although the variance estimators deteriorate when varying degrees of non-normality is introduced through simulation; however, the POV method is shown to be a more stable measure of variance in the aggregate. The POV method also provides non-negative, stable estimates for interaction when compared to the ANOVA method. The POV method is shown to be more stable, particularly in low sample size situations. Based on these findings, it is suggested that the POV is not a replacement for more complex analysis methods, but rather, a supplement to them. POV is ideal for preliminary analysis due to the ease of implementation, the simplicity of interpretation, and the lack of dependency on statistical analysis packages or statistical knowledge. / Dissertation/Thesis / Masters Thesis Industrial Engineering 2015
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