Every day data communication networks carry more and more information, which sometimes is very important and needs to be delivered in time. To achieve that, data transfer networks must meet quality requirements that are formed in SLA contracts between clients and service providers. Supplied data transfer link’s quality is described by worldwide defined quality metrics, which include: one way delay, IP delay variation, link loss and round trip time. In order to measure these metrics, special software was created during projects “QoS monitoring system” first phase. This paper continues the project and explores available tuning methods for created software including time synchronization and mobility problems in order to provide better accuracy with higher mobility. New system topology and time offset correction using measurement packets were proposed during the analysis part. Possible system improvements were put to test in order to evaluate the efficiency during the experiment.

The purpose of this work is to optimize the chemical composition as well as the heat treatment for improving the mechanical performance of the TRIP steel by employing the theoretical models. TRIP steel consists of the microstructure with ferrite, bainite, retained austenite and minor martensite. Austenite contributes directly to the TRIP effect as its transformation to martensite under the external stress. In order to stabilize austenite against the martensitic transformation through the heat treatment, the two-step heat treatment is broadly applied to enrich the carbon and stabilize the austenite. During the first step of the heat treatment, intercritical annealing (IA), a dual phase structure (ferrite+austenite) is achieved. The austenite can be initially stabilized because of the low carbon solubility of ferrite. The bainite isothermal treatment (BIT) leads to the further carbon enrichment of IA-austenite by the formation of carbon-free ferrite. Comparing to the experiments, the thermodynamic and kinetic models are the lower and upper bounds of the carbon content of retained austenite. The mechanical properties are predicted using the swift model based on the predicted microstructure. In this work, a theoretical approach is coupled to a Genetic Algorithm-based optimization procedure to design (1) the heat treated temperatures to maximize the volume fraction of retained austenite in a Fe-0.32C-1.42Mn-1.56Si alloy and the chemical composition of (2) Fe-C-Mn-Si and (3) Fe-C-Mn-Si-Al-Cr-Ni alloy. The results recommend the optimum conditions of chemical composition and the heat treatment for maximizing the TRIP effect. Comparing to the experimental results, this designing strategy can be utilized to explore the potential materials of the novel alloys.

Transformation-induced plasticity (TRIP) steels have excellent strength, ductility and work hardening behaviour, which can be attributed to a phenomenon known as the TRIP effect. The TRIP effect involves a metastable phase, retained austenite (RA), transforming into martensite as a result of applied stress or strain. This transformation absorbs energy and improves the work hardening rate of the steel, delaying the onset of necking. This work describes two distinct TRIP steel microstructures and focuses on how microstructure affects the RA-to-martensite transformation and the uniaxial tensile behaviour. A two-step heat treatment was applied to an aluminum-alloyed TRIP steel to obtain a microstructure consisting of equiaxed grains of ferrite surrounded by bainite, martensite and RA -- the equiaxed microstructure. The second microstructure was produced by first austenitizing and quenching the steel to produce martensite, followed by the two-step heat treatment. The resulting microstructure (labelled the lamellar microstructure) consisted of elongated grains of ferrite with bainite, martensite and RA grains. Both microstructural variants had similar initial volume fractions of RA. A series of interrupted tensile tests and ex-situ magnetic measurements were conducted to examine the RA transformation during uniform elongation. Similar tests were also conducted on an equiaxed microstructure and a lamellar microstructure with similar ultimate tensile strengths. Results show that the work hardening rate is directly related to the RA transformation rate. The slower transformation rate, or higher RA stability, that was observed in the lamellar microstructure enables sustained work hardening at high strains. In contrast, the equiaxed microstructure has a lower RA stability and thus exhibits high values of work hardening at low strains, but the effect is quickly exhausted. Several microstructural factors that affect RA stability were examined, including RA grain size, aspect ratio, carbon content and spatial distribution of the phases. Two of these factors were characteristic of only the lamellar microstructures and led to higher RA stabilities: elongated RA grains and RA grains being primarily surrounded by bainite. The results were also compared with previous work on a silicon-alloyed TRIP steel to show that the aluminum-alloyed compositions could achieve similar, if not better, combinations of strength and ductility. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2012-09-24 16:52:28.032

Les différents travaux de recherche menés dans le cadre de la présente thèse, ont pour objectifs de :(i) comprendre les mécanismes et phénomènes prenant part dans la plasticité des aciers en présence d'une transformation de phases diffusive ou martensitique. (ii) développer des outils de prédiction de TRIP capables d'une part de reproduire correctement cette déformation macroscopique pour des cas de chargements complexes et d'autre part de nous offrir des enseignements sur les interactions élasto-visco-plastiques locales entre phase naissante et phase parente. Pour ce faire, de nouvelles campagnes d'essais TRIP à chargements uni- et bi-axiaux constants ou variables ont été menées sur l'acier 35NCD16 pour une transformation austénitemartensite et l'acier 100C6 pour une transformation austénite-perlite. En complément, des essais de traction-compression et relaxation ont été réalisés pour caractériser les propriétés élastoviscoplastique ssur chacune des 2 phases de l'acier 100C6...

This thesis aims to improve sales forecasting in the context of passenger airlines. We study two important issues that could potentially improve forecasting accuracy: day-to-day price change rather than price itself, and linking flights that are likely to be considered as pairs for a round trip by passengers; we refer to the latter as the Round-Trip Model (RTM). We find that price change is a significant variable regardless of days remaining to flight in the last three weeks to flight departure, which opens the possibility of planning for revenue maximizing price change patterns. We also find that the RTM can improve the precision of the forecasting models, and provide an improved pricing strategy for planners. In the study of the effect of price change on sales, analysis of variance is applied; finite regression mixture models were tested to identify linked traffic in the two directions and the linked flights on a route in reverse directions; adaptive neuro-fuzzy inference system (ANFIS) is applied to develop comparative models for studying sales effect between price and price change, and one-way versus round-trip models. The price change model demonstrated more robust results with comparable estimation errors, and the concept model for the round-trip with only one linked flight reduced estimation error by 5%. This empirical study is performed on a database with 22,900 flights which was obtained from a major North American passenger airline.

The economic behavior of Hawaii's longline fishers was analyzed using a cross-sectional and time-series dataset from 1991 to 1998. Three empirical essays were written analyzing (1) the technological and economic interrelationships in the longline fishery, (2) trip choice behavior, and (3) vessel entry, stay, and exit decisions of the longline fishers. Studies on the analysis of technical-economic interrelationships among species suggest that Hawaii's longline fishery is characterized by a joint production process. Substantial economic and technical interactions existed, as many of the cross-price elasticities were significant, indicating either complementary or substitution relations in production among species. There was insufficient evidence for rejecting the null hypothesis of input-output separability. Output supplies were independent of their own prices. Output elasticities to effort and stock levels were positive and significant. Fishers' trip (or fishery) choice behavior was examined by applying the utility theoretic mixed model. Fishers exhibited utility maximizing behavior by choosing the trip type that yields best return, but they appeared to be risk-averse by choosing trip alternatives with less varying return, ceteris paribus. They exhibited "inertia" in switching to an alternative trip. Stock abundance indices of major species significantly influenced the type of trip chosen. Older and smaller vessels were more likely to choose the tuna trip rather than the swordfish or the mixed trip. Finally, the vessel entry-stay-exit decision was analyzed by applying the multinomial logit (unordered) model. The probability of a vessel to stay (or exit) in the fishery increased (or decreased) for an increase in the annual earning potential of a fisher. The fleet congestion level had a significant impact on the vessel entry-stay-exit decision. Vessels were reluctant to enter to and willing to exit from the fishery for an increase in fleet size. Entry-stay-exit decision was also based on a perceived abundance in major species stock levels. A vessel was more likely to stay in the fishery when the vessel owner was a Hawaii resident or a vessel captain. Vessel age had little impact on the entry-stay-exit decision. Simulation of probabilities for both forms of choices was carried out under different fleet structure and stock conditions.

Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1988. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 192-198).

Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / A presente pesquisa discute de que maneira as leitoras da revista TRIP para mulher (Tpm) se apropriam do conteúdo da publicação, em especial no que tange à figura feminina. Discute-se se a mulher apresentada pela revista, que se posiciona como inovadora em relação à imprensa feminina, reforça estereótipos de gênero e quais são as formulações das leitoras a esse respeito. Investiga-se de que maneira tal discurso está presente em suas vidas cotidianas, buscando-se compreender como ele se liga a suas práticas sociais e culturais. Com esse objetivo, foi realizada uma pesquisa qualitativa com 15 leitoras, por meio do método de entrevistas individuais semi-estruturadas. Após a realização das entrevistas, foram formuladas categorias de análise, que ajudaram a compreender a realidade pesquisada. Foram identificados diferentes discursos a respeito da mulher contemporânea, que mostram uma permanente negociação de sentido entre a revista e suas leitoras. / This research discusses how the readers of the magazine TRIP para mulher (Tpm) appropriate the content of the publication, especially regarding the female figure. We discuss if women presented by the magazine, which positions itself as an innovator in relation to women's press, reinforces gender stereotypes and what are the formulations of readers in this regard. This research investigates how such discourse is present in their daily lives, trying to understand how it binds to its social and cultural practices. With this objective, a qualitative study with 15 readers was conducted, using the method of semi-structured individual interviews. After the interviews were formulated categories of analysis that helped understand the reality studied. There were identified different discourses about the contemporary woman, showing a sense of permanent negotiation between the magazine and its readers.

Made available in DSpace on 2016-06-02T20:00:53Z (GMT). No. of bitstreams: 1 5462.pdf: 6522300 bytes, checksum: 08eb2b085e1c0d4ae808a440e1e9dc9c (MD5) Previous issue date: 2012-06-28 / Financiadora de Estudos e Projetos / Developments in the health sector, especially those placed in public care are fundamental to the care of the entire population of a city and region. The location of health projects such as "Santa Casa" was made since many decades ago, or even the latest developments seem not to have been concerned with the accessibility of the population. Moreover, the travels generators poles, including the establishments of the health sector, cause significant impacts on its surroundings and also in the transport systems of the region they live. In general, the public hospitals, mainly in Brazil, aim to attend the portions of the population of low income families that use displacement on foot, by car or public transport. As a result, this study aimed to perform an analysis of levels of accessibility to hospitals such as "Santa Casa", considering mainly the population groups that most need the public health. The proposed method is based on an indicator (time) to measure accessibility to hospitals by different ways: on foot, by car and public transport, making use of geographic information systems. IBGE data were used to estimate the income levels of traffic areas. A survey with users from hospitals located in the cities of Rio Claro and São Carlos was performed to characterize the source and location of the travel. Using the data obtained in both case studies it was found that the population, in most cases, has used the car travel to hospitals. The accessibility by car was high, because even in distant neighborhoods, the travel time was at 15 minutes for both cities. In contrast, traveling on foot had low accessibility in relation to hospitals, mainly in the distant neighborhoods. The analysis done for public transport accessibility shows the minimum value of 30 minutes to Rio Claro and 35 minutes to São Carlos. Analyzing data from the 2000 Census, it is evident that the population with lower monthly household income is concentrated in the suburb areas of the cities. Thus, the distances done every day by the citizens compromise the access to different services available in the cities, as the travel time, or the lack of public transport routes, or lack of conditions of using public transport. / Empreendimentos do setor de saúde, principalmente os inseridos na rede pública de atendimento, são fundamentais para o atendimento de toda a população de uma cidade e região. A localização dos empreendimentos de saúde do tipo Santa Casa , em geral, foi feita há muitas décadas, ou mesmo os empreendimentos mais recentes, parecem não ter tido a preocupação com a acessibilidade da população. Além disso, os polos geradores de viagens, dentre eles os estabelecimentos do setor de saúde, causam impactos significativos nos seus arredores e também nos sistemas de transporte da região em que estão inseridos. Os hospitais públicos, principalmente no Brasil, visam atender às parcelas da população de menor renda, que se utilizam de deslocamentos a pé, por automóvel ou por transporte coletivo público por ônibus. Em vista disso, este trabalho teve como objetivo realizar uma análise dos níveis de acessibilidade a hospitais do tipo Santa Casa , considerando, principalmente, as parcelas da população que mais necessitam do sistema público de saúde. O método proposto se baseou em um indicador (tempo) para se medir a acessibilidade aos hospitais pelos modos a pé, automóvel e transporte coletivo, fazendo-se uso de sistemas de informações geográficas. Dados do IBGE foram utilizados para a estimativa de níveis de rendimento de zonas de tráfego. Uma pesquisa com usuários dos hospitais localizados nas cidades de Rio Claro e São Carlos foi realizada para a caracterização e localização de origem das viagens. Através dos dados obtidos nestes os estudos de caso, verificou-se que a população, na maioria das vezes, utiliza o automóvel para realizar as viagens aos hospitais. A acessibilidade por automóvel obteve tempo de viagem de até 15 minutos, mesmo em bairros mais distantes, para as duas cidades. Em contrapartida, para as viagens a pé, o tempo de viagem médio foi de até 20 minutos em um raio de 1,5 km dos hospitais, para os estudos de caso. A análise feita para o transporte coletivo mostra o valor de tempo mínimo de 30 minutos para Rio Claro e de 35 minutos para São Carlos. Analisando-se os dados do Censo 2000, fica evidente que a população com menor rendimento médio mensal familiar se concentra nas regiões periféricas das cidades. Assim, as distâncias a serem vencidas diariamente pelos cidadãos comprometem o acesso aos diversos serviços disponíveis nas cidades, seja pelo tempo de viagem, ou pela falta de linhas de transporte público, ou de condições de se utilizar o transporte público.