In the modern urban lifestyle, more and more people are exposed to noise pollution in form of traffic noise. As a response to this, the automotive OEMs (Original Equipment Manufacturer) are put under pressure to reduce the emitted noise from vehicles. To be able to meet the upcoming, stricter regulations, the automotive OEMs seeks new techniques to be able to front load the pass-by noise engineering in the vehicle development process and to identify and understand the different sources that contributes to the exterior noise.Earlier exterior sources ranking using ASQ (Airborn Source Quantification) with an energetic approach during pass-by noise test has yielded very good and reliable results for an ICE (Internal Combustion Engine) vehicle.In this Master Thesis, two exterior source ranking methods have been tested and evaluated for an electric vehicle during in-room pass-by noise test. The two methods were: ASQ and OPA (Operational Path Analysis). In total, five models were built from the two methods and each model was evaluated for, in total, three driving conditions corresponding to the current ISO362-1:2007 and the proposed, revised version.The results show that the ASQ models are not capable to correctly estimate the engine contribution due to its high tonality. Moreover, it was seen that the energetic ASQ model is very sensitive to small changes. Both ASQ models underestimated the tire noise.The OPA model on the other hand managed to estimate the total contribution very well. Both the engine contribution and the tire contributions are well estimated. Nevertheless, OPA as method has several weaknesses and building an OPA model is not a straightforward task. Its weaknesses and the process to reach a final OPA model are discussed in this thesis.It was seen that one of the most crucial steps in an OPA model is to have clean references to get meaningful results. A MIMO-FIR filter was therefore used to filter out engine harmonics from the tire references. Its principles and importance for the end results are also discussed.Included is also an overview of the basic principles in TPA (Transfer Path Analysis), ASQ, OPA and in room pass by noise test as well as a description of the test campaign.

Thesis (PhD)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: Please refer to full text for abstract.

published_or_final_version / Business Administration / Master / Master of Business Administration

<p>Fans are often used in equipment such as home appliances andelectronic equipment where the margin of profit is small butcustomers demands on a low noise level are high. Therefore,methods for predicting the noise emitted by an applicationincluding one or several fans are desirable in order toimprove, accelerate and reduce the cost of low-noise design.The Noise Shaping Technology (NST) has been developed withinthe EC-project NABUCCO in order to fulfil the aboverequirements on a prediction method. According to NST, thenoise source (not necessary a fan) is described by one orseveral noise descriptors, CSSs, and the correspondingtransmission paths through the structure described by one orseveral transfer functions, ACFs. In this thesis, theapplicability of NST is evaluated on a cabinet for electronicequipment where small axial cooling fans constitute the primarysources of the airborne sound.</p><p>As an axial fan is a complex source of sound,simplifications are necessary when modelling its acousticproperties. Therefore, the sound radiation of an axial fan infree space was examined by expanding the generated soundpressure field into spherical harmonics. The conclusion on asource model for the cabinet example, where the fans are moreor less In-duct mounted, is a modified single axial dipole. Themodel is expected to be valid in the entire frequency range ofinterest except in the mid-frequency range where the modaldensity is low. In order to improve the source model in thisfrequency range, a future model based on a rotating dipole isproposed.</p><p>The sound power of a small axial fan is measured in an ISO10302 test-rig. In order to take account of flow conditions,acoustically transparent ducts have been developed. These shallbe attached to the test-rig when measuring the sound power ofthe fan. A simple but practical method of how to correct thesound power for the baffling effect of the test-rig has alsobeen developed. Finally, the sound power can be converted intodipole force, which is the airborne CSS corresponding to thesingle axial dipole model.</p><p>The corresponding airborne transfer function (ACF), i.e.,from dipole force at the source point to sound pressure at thereceiver point, is measured reciprocally by taking use ofLyamshevs reciprocity relation.</p><p>From multiplication of the CSS and the ACF, the soundpressure can be predicted. The prediction shows quite goodagreement with the measured values.</p><p><b>Keywords:</b>axial fan, airborne sound, sourcecharacterisation, transmission path analysis, In-duct,spherical harmonics, rotating dipole, installation effects, ISO10302, flow conditions, baffling effect, acousticallytransparent ducts, Lyamshevs reciprocity relation, reciprocity,CSS, ACF, GSM, NST.</p>

It is widely accepted that the LGB (Lesbian, gay and bisexual) population have a higher risk of psychological distress compared to their heterosexual counterparts. Meyer (2003) proposed the minority stress model to explain this increased prevalence. This model proposed that the LGB population are subjected to additional stressors due to their minority status which results in the increased psychological distress observed. The purpose of this study was to investigate some of the risk factors proposed by this model, specifically experiences of sexual prejudice, negative internalised beliefs about homosexuality/bisexuality, coping strategies and how these factors interact to influence the development of psychological distress. This study included 542 LGB individuals who completed measures of sexual prejudice, internalised homophobia, coping strategies and current levels of psychological distress using an online survey. The study found a high prevalence of sexual prejudice within the sample, with 84% of the sample reporting at least one experience of sexual prejudice. 67% reported being verbally abused and 17% reported being physically assaulted. A high number of participants scored above the cut-off for a diagnosis of depression (27%) and anxiety (19%). Regression and path analysis revealed that maladaptive coping had the strongest effect on psychological distress. Sexual prejudice and internalised homophobia, also both had a significant direct impact upon psychological distress, and they were also partially mediated by maladaptive coping. Problem-focused coping was found to be a protective factor with a direct, albeit weak, effect on psychological distress. Problem-focused coping also partially mediated the relationship between sexual prejudice and psychological distress, slightly reducing the negative impact of sexual prejudice. The results suggest that maladaptive coping was the greatest risk factor, out of the ones measured, in the development of psychological distress in the LGB population. The outcomes suggest that clinical psychologists may wish to target their interventions at the development of more adaptive coping strategies, and the reduction of internalised homophobia. They should consider ways to reduce experiences of sexual prejudice by working at a community level to reduce the stigma of homosexuality/bisexuality.

This study examines the relationship between voluntary associations and the psychological well-being of older people through path analysis. The goals of the study were: (1) to ascertain whether differential research findings are due to measurement artifact, (2) to evaluate the assertions of traditional activity theory versus those of a modified activity theory taking quality into account, and (3) to isolate factors which contribute to and/or mediate the relationship of voluntary-association participation and psychological well-being. Analysis was conducted at two levels. First, a model was developed to study individual participation in voluntary associations, satisfaction with participation, and well-being. Second, a model was developed to examine types of volimtary associations and their effects on satisfaction with participation and on well-being. Subjects were 50 members of voluntary associations who were recruited from target groups in the Durham, North Carolina area. There were 26 males and 24 females. They ranged in age from 61 to 90. The results of the individual path analysis indicate that differential findings due to measurement artifact is likely. After controlling for the effects of health, education, income, and social desirability bias in the model, voluntary-association activity as measured by the Chapin scale was significantly correlated with psychological well-being as measured by the Bradburn scale; however, measurement of volantary-association activity by an average number of meetings measure was not correlated significantly with any measure of well-being. In addition, the Chapin measure did not correlate significantly with the LSI-Z or with the Cantril Ladder. The examination of traditional activity theory versus modified activity theory was somewhat inconclusive, although the results did suggest that mere participation may have effects on psychological well-being that are equal to or greater than the effects of satisfaction with participation. The results of the voluntary association path analysis indicate that their characteristics have consequences both for satisfaction with voluntary associations and for psychological well-being. People who belonged to larger groups were significantly more satisfied with those groups and also were significantly happier. Also, even though people who belonged to age-graded groups were slightly more satisfied with these groups, they were significantly less happy. In addition, people who belonged to church-related groups were slightly more satisfied with these groups, but were significantly less happy. Finally, people who belonged to instrumental groups were slightly less satisfied with these groups than with more expressive groups and were slightly less happy. Discussion focused on possible explanations for the findings. It was suggested that a "happiness" measure seems more sensitive to effects such as those of voluntary-association activity. As for satisfaction with voluntary associations, it was acknowledged that the mere fact that respondents are taking an active part in life may be a key factor to their well-being. As explanations for the findings related to size of voluntary associations, it was suggested that large group activity may be less emotionally demanding and/or may allow contact with more potential friends. For age-graded groups, it was suggested that many older people may maintain a view of themselves as "younger" as the result of non-age-graded activities. For church- related groups, it was suggested that prior findings are due to the relationship between religiosity and well-being rather than characteristics of such groups. Finally, for the instrumental-expressive variable, it was suggested that older people such as in this sample may not value "feeling useful" as much as has been thought. Suggestions for future research included alternative methods of measuring association satisfaction, longitudinal analysis with representative sampling, and further investigation of voluntary-association characteristics. / This thesis was digitized as part of a project begun in 2014 to increase the number of Duke psychology theses available online. The digitization project was spearheaded by Ciara Healy.

The purpose of this study was to propose an exploratory causal model that examines the influence of several antecedent variables on burnout. The antecedent variables included age, marital status, education, tenure, Type A personality, Jungian types, death anxiety, leadership style, job satisfaction, stress, coping efficacy, and marital satisfaction. The validity of the causal model was tested by using path analysis. Subjects were 100 male firefighters who completed self-report measures of the predictor variables. Instruments included the Jenkins Activity Survey, Myers- Briggs Type Indicator, Collett-Lester Attitudes Toward Death Scale, Leader Behavior Description Questionnaire, Job Descriptive Index, Perceived Job Stress, The Coping Inventory, Dyadic Adjustment Scale, and the Maslach Burnout Inventory. Perceived work stress made the only direct contribution to the variance in burnout. Direct paths were found to stress from job satisfaction, Type A personality, and single marital status. Job satisfaction was directly related to leadership (consideration) and the Jungian Introversion, Feeling, and Perceiving preferences. Direct paths were found to marital satisfaction from death anxiety, leadership (consideration), and leadership (structure). Leadership (consideration) was directly related to structure. From the above results, it can be concluded that perception of stress is an important factor in predicting burnout. Other factors are important contributors to stress and have indirect effects on burnout. Implications for the prevention and treatment of job burnout are discussed.

Thesis (Ph.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / The size, diversity and continued growth of the World Wide Web combine to make its understanding difficult even at the most basic levels. The focus of our work is in developing novel methods for measuring and analyzing the Web which lead to a deeper understanding of its performance. We describe a methodology and a distributed infrastructure for taking measurements in both the network and end-hosts. The first unique characteristic of the infrastructure is our ability to generate requests at our Web server which closely imitate actual users. This ability is based on detailed analysis of Web client behavior and the creation of the Scalable URL Request Generator (SURGE) tool. SURGE provides us with the flexibility to test different aspects of Web performance. We demonstrate this flexibility in an evaluation of the 1.0 and 1.1 versions of the Hyper Text Transfer Protocol. The second unique aspect of our approach is that we analyze the details of Web transactions by applying critical path analysis (CPA). CPA enables us to precisely decompose latency in Web transactions into propagation delay, network variation, server delay, client delay and packet loss delays. We present analysis of pe1formance data collected in our infrastructure. Our results show that our methods can expose surprising behavior in Web servers, and can yield considerable insight into the causes of delay variability in Web transactions. / 2031-01-01

O presente trabalho teve por objetivo compreender sistemas de produção agrícola e agropecuária a campo pela avaliação da diversidade, funcionalidade e dinâmica espaço-temporal de espécies, assim como pelo padrão de variação da qualidade do solo e dos fatores que a determinam. Para isso, foi avaliado na “Agropecuária Guajuvira” localizada no município de São Miguel das Missões – RS quatro sistemas conservacionistas de produção. Foram eles: 1- sistema agrícola tradicional, representando a sucessão soja/trigo e soja/aveia preta amplamente praticada na região; 2- Sistema agrícola irrigado, semelhante ao anterior, mas, com recente inserção de milho no verão; 3- Sistema integrado de produção agropecuária 1, representando a sucessão soja/pastejo de azevém e 4- Sistema integrado de produção agropecuária 2, representando um sistema misto por apresentar alterações na composição de espécies no inverno pela sucessão soja/aveia preta pastejada, soja/aveia preta não pastejada e soja/nabo forrageiro/trigo O estoque de carbono (EC), estabilidade de agregados do solo (EAS) e índice de manejo de carbono (IMC) foram escolhidos como indicadores da qualidade sistêmica do solo. Seus padrões de variação foram compreendidos pela integração de atributos químicos, físicos e biológicos do solo, assim como por variáveis de paisagem inerentes às unidades amostrais. Os fatores que caracterizaram os sistemas de produção e o uso da análise de caminhos permitiram um maior entendimento de sistemas complexos de produção agrícola e agropecuária a campo. / The aim of this research was to understand agricultural and integrated crop-livestock production systems by the species diversity, functionality and spatial-temporal dynamics evaluation, as well as of the variation pattern of soil quality and factors that determine then. For this, four no-tillage production systems were evaluated on the "Agropecuária Guajuvira" located in São Miguel das Missões county in southern Brazil. The production systems were: 1- Traditional agricultural system, representing the succession soybean/wheat and soybean/black oat widely practiced in the region; 2- Irrigated agricultural system, similar to the previous one, but, with recent insertion of corn in the summer; 3 - Integrated crop-livestock system 1, representing the succession of soybean /grazed ryegrass and 4 - Integrated crop-livestock system 2, representing a mixed system due changes in species composition during winter by succession of soybean/grazed black oat, soybean/no-grazed black oat and soybean/forage radish/wheat The carbon stock (CS), soil aggregate stability (SAS) and carbon management index (CMI) were chosen as systemic soil quality indicators. Their variation patterns were understood by the integration of chemical, physical and biological soil attributes, as well as by landscape variables inherent to the sampling units. The factors that characterized the production systems and the path analysis utilization allowed a greater understanding of complex agricultural and integrated crop-livestock production systems in the field.

Appreciative Inquiry (AI) introduces a new approach to educational change. Most state and federal initiatives for educational change grow out of a deficit model of what is wrong with schools and what is needed to fix them. Implementation of new reforms has historically been mandated by administrators with little impact. The emphasis of AI is upon what is right with the organization and forms the basis for new initiatives and further change. This model proposes a cycle of inquiry used by leaders who distribute leadership across their constituents. Organizational learning is a process of individual and collective inquiry that modifies or constructs organizational theories-in-use and changes practice. Using AI as a process to implement the Common Core State Standards (CCSS), embraces a distributed leadership structure, produces organizational learning opportunities, and creates the conditions for a more impactful implementation of the next reform. The study explored the relationship of the AI, distributed leadership, and organizational learning qualities that exist within the five unified school districts in the High Desert. Additionally, the relationships were analyzed in combination with participants’ preparedness for the implementation of the CCSS reform. To explore the relationships, a survey was created based on four already existing instruments. A path diagram was proposed and path analysis was conducted. Inventories of appreciative capacities and principles, distributed leadership, and organizational learning capabilities in an educational system provided insight into the applicability of using AI as a process for implementation of the CCSS and future educational reforms. Throughout the analysis significant correlations existed and the model held. Utilizing appreciative inquiry, distributed leadership, and organizational leadership singularly or in combination within districts would strengthen CCSS implementation.