The quest to accurately capture flow phenomena with length-scales both short and long and to accurately represent complex flow phenomena within disparately sized geometry inspires a need for an efficient, highidelity, multi-block structured computational fluid dynamics (CFD) parallel computational scheme. This research presents and demonstrates a more efficient computational method by which to perform multi-block structured CFD parallel computational simulations, thus facilitating higheridelity solutions of complicated geometries (due to the inclusion of grids for "small" flow areas which are often merely modeled) and their associated flows. This computational framework offers greater flexibility and user-control in allocating the resource balance between process count and wallclock computation time. The principal modifications implemented in this revision consist of a "multiple grid-block per processing core" software infrastructure and an analytic computation of viscous flux Jacobians. The development of this scheme is largely motivated by the desire to simulate axial compressor stall inception with more complete gridding of the flow passages (including rotor tip clearance regions) than has been previously done while maintaining high computational efficiency (i.e., minimal consumption of computational resources), and thus this paradigm shall be demonstrated with an examination of instability in a transonic axial compressor. However, the paradigm presented herein facilitates CFD simulation of myriad previously impractical geometries and flows and is not limited to detailed analyses of axial compressor flows. While the simulations presented herein were technically possible under the previous structure of the subject software, they were much less computationally efficient and thus not pragmatically feasible; the previous research using this software to perform three-dimensional, full-annulus, timeurate, unsteady, full-stage (with sliding-interface) simulations of rotating stall inception in axial compressors utilized tip clearance periodic models, while the scheme here is demonstrated by a simulation of axial compressor stall inception utilizing gridded rotor tip clearance regions. As will be discussed, much previous research --- experimental, theoretical, and computational --- has suggested that understanding clearance flow behavior is critical to understanding stall inception, and previous computational research efforts which have used tip clearance models have begged the question, "What about the clearance flows?". This research begins to address that question.

This research is motivated by identified gaps in contemporary planning practices and production processes within firms. Relying solely on experiential knowledge has proven limiting, necessitating a more systematic approach. Previous instances of data anomalies, particularly ongoing challenges in achieving satisfactory delivery reliability, have underlined the need for deeper insights into underlying patterns. The objectives of this study are: • To identify and analyze specific obstacles and challenges affecting load balance and delivery security in Borl.nge's production system. • To explore various methods or strategies aimed at enhancing the process of generating reliable capacity forecasting methods. Both primary and secondary research methods were employed. Primary methods included interviews and the development of a forecast model, while secondary studies encompassed the latest research in the field. The thesis revealed five primary factors hindering capacity attainment: 1. WIP(work in progress)/ slabs material shortages disrupt production flow and escalate costs due to the need for external sourcing of slabs. 2. Transport issues, including incorrect internal deliveries and the weather conditions, pose challenges. 3. Personnel shortages hinder the efficient utilization of production capacity. 4. Machine breakdowns result in production interruptions, leading to capacity loss and inefficiency. 5. Inventory problems, such as insufficient capacity and poor management, impede smooth production operations. Additionally, the second objective was addressed by implementing exponential smoothing for capacity planning forecasts. By updating forecasts every 13 weeks, this study improves the production forecast.

Storage systems used for supercomputers and high performance computing (HPC) centers exhibit load imbalance and resource contention. This is mainly due to two factors: the bursty nature of the I/O of scientific applications; and the complex and distributed I/O path without centralized arbitration and control. For example, the extant Lustre parallel storage system, which forms the backend storage for many HPC centers, comprises numerous components, all connected in custom network topologies, and serve varying demands of large number of users and applications. Consequently, some storage servers can be more loaded than others, creating bottlenecks, and reducing overall application I/O performance. Existing solutions focus on per application load balancing, and thus are not effective due to the lack of a global view of the system. In this thesis, we adopt a data-driven quantitative approach to load balance the I/O servers at extreme scale. To this end, we design a global mapper on Lustre Metadata Server (MDS), which gathers runtime statistics collected from key storage components on the I/O path, and applies Markov chain modeling and a dynamic maximum flow algorithm to decide where data should be placed in a load-balanced fashion. Evaluation using a realistic system simulator shows that our approach yields better load balancing, which in turn can help yield higher end-to-end performance. / Master of Science / Critical jobs such as meteorological prediction are run at exa-scale supercomputing facilities like Oak Ridge Leadership Computing Facility (OLCF). It is necessary for these centers to provide an optimally running infrastructure to support these critical workloads. The amount of data that is being produced and processed is increasing rapidly necessitating the need for these High Performance Computing (HPC) centers to design systems to support the increasing volume of data. Lustre is a parallel filesystem that is deployed in HPC centers. Lustre being a hierarchical filesystem comprises of a distributed layer of Object Storage Servers (OSSs) that are responsible for I/O on the Object Storage Targets (OSTs). Lustre employs a traditional capacity-based Round-Robin approach for file placement on the OSTs. This results in the usage of only a small fraction of OSTs. Traditional Round-Robin approach also increases the load on the same set of OSSs which results in a decreased performance. Thus, it is imperative to have a better load balanced file placement algorithm that can evenly distribute the load across all OSSs and the OSTs in order to meet the future demands of data storage and processing. We approach the problem of load imbalance by splicing the whole system into two views: filesystem and applications. We first collect the current usage statistics of the filesystem by means of a distributed monitoring tool. We then predict the applications’ I/O request pattern by employing a Markov Chain Model. Finally, we make use of both these components to design a load balancing algorithm that eventually evens out the load on both the OSSs and OSTs. We evaluate our algorithm on a custom-built simulator that simulates the behavior of the actual filesystem.

Made available in DSpace on 2016-04-04T18:31:28Z (GMT). No. of bitstreams: 1 Adriano Almeida Goes.pdf: 1890295 bytes, checksum: 24b4098cee62cc9c7d9d7e7d523ea3c2 (MD5) Previous issue date: 2009-10-30 / This work proposes a methodology for intelligent distribution of traffic between users and cells in a mobile network with adaptive modulation. In this dissertation a new method of handover to enable the proposal for load balancing traffic, serving as support for the planning and design of these networks. An example of this case is the IEEE802.16e adopted as a platform in this work. As developed a simulation platform that contains the requirements necessary to analyze and compare the current method of handover with the proposed method under different topologies. The results show a gain in the effective data rate of the cell 25% of the proposed method of handover for the current method of handover. Index: IEEE802.16e, Load Balance, Handover, mobile WiMAX / Este trabalho prop?e uma metodologia para distribui??o inteligente de usu?rios e tr?fego entre c?lulas de uma rede m?vel com modula??o adaptativa. Para isso foi proposto nesta disserta??o um m?todo de Handover que viabiliza a proposta de balanceamento de tr?fego servindo de apoio para o planejamento e dimensionamento destas redes, Como ? o caso da IEEE802.16e, plataforma utilizada neste trabalho. Foi desenvolvida uma plataforma de simula??o que cont?m os requisitos necess?rios para analisar e comparar o m?todo atual de Handover com o m?todo proposto sob topologias diferentes. Os resultados mostram um ganho efetivo na taxa de dados geral da c?lula de 25% do m?todo de Handover proposto em rela??o a m?todo de Handover atual.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Nowadays, the water resource degradation may be verified at any Brazilian cities just by observing its stream flow. Accordingly, the conditions of the stream flows in the Federal University of Santa Maria - UFSM (southern Brazil, Rio Grande do Sul State) follow the degradation. Therefore, the present research intends to analyze a methodology for evaluation of the environment impacts in order to collaborate to water resources management, according to smaller watersheds. This analysis allows that pollution sources identify their environment problems and control the pollution to adjust its conditions to the Federal and Spatial Legislation. Thus, the purposed methodology evaluates the three major parameters: i) surface water resources; ii) groundwater resources; iii) liquid effluents. The surface water resource is evaluated by the quali quantitative monitoring of several parameters of water quality. This control is carried out in two monitoring stations located at the UFSM. These stations are: Gráfica gutter where the upstream subwatershed loads are monitored and Pains gutter where the downstream subwatershed loads are monitored. This division allows finding the pollutant load generated by the respective subwatershed separately (Load Balance), as well as the effluent liquid volume generated by the subwatersheds. The purposed methodology for the evaluation of liquid effluents supplied by UFSM considers the identification of the main point pollution sources and also the quali quantitative monitoring of these effluents. To evaluate the pollution vulnerability of the groundwater it was used the G.O.D method. In this method, some weights are defined in order to represent the geological characteristics and the groundwater level. The qualitative groundwater pollutant risk was determined by crossing the vulnerability data and the liquid effluent data. Hence, by means of inquiry applications, the sanitary - environment characterization of the UFSM external area was achieved, according to the watershed in analysis. The analysis of the outcomes demonstrates that if the pollutant loads were considered, so the water quality of the downstream watershed become highly dependent of the pollutant load deposited in the upstream watershed. Accordingly, it was concluded that the methodology of Load Balance allows verifying the influence of the anthropogenic impacts connected to the degradation of surface water quality. Besides, the methodology presents the pollution supplied to the different basin areas (downstream and upstream), which becomes an appropriate system to support the water quality control in smaller watersheds. The identification, specialization and evaluation of the point pollution sources, together with the evaluation of the pollution vulnerability of the groundwater, permit to hierarch the places extremely affected by the pollution. This fact demonstrates that a simple combination of those methods is a useful tool for the decision makers. The data from water quality of the some well sources in UFSM call attention to discordance between the limits established by the actual legislation and the achieved outcomes, concerning some water quality parameters. To conclude, it is possible to consider that the UFSM groundwater must be suffering the interference of the mankind actions related to the pollutant risk in the watershed. / Atualmente, a degradação dos recursos hídricos pode ser observada em qualquer cidade brasileira apenas pela visualização de seus córregos. Essa realidade não é diferente no Campus da Universidade Federal de Santa Maria (UFSM). Nesse contexto, a presente pesquisa visa ensaiar uma metodologia de avaliação de impacto ambiental que contribua para a gestão dos recursos hídricos em pequenas bacias hidrográficas e possibilite que instituições potencialmente poluidoras caracterizem seus problemas ambientais e controlem seus poluentes adequando-se à legislação Federal e Estadual vigentes. A metodologia utilizada consiste na avaliação de três variáveis principais: i) recursos hídricos superficiais; ii) recursos hídricos subterrâneos; e iii) efluentes líquidos. A avaliação dos recursos hídricos superficiais consiste no monitoramento quali-quantitativo de diversos parâmetros de qualidade da água, realizado em duas estações de monitoramento localizadas no Campus da UFSM: Calha da Gráfica, onde são monitoradas as cargas da sub-bacia de montante (área externa ao Campus e semi-urbanizada), e Calha do Pains, onde são monitoradas as cargas da sub-bacia de jusante (área predominantemente do Campus, com poucas habitações particulares). Esta divisão possibilita a atribuição da carga poluente gerada pelas respectivas sub-bacias individualmente (balanço de cargas), assim como o volume de efluentes líquidos gerado por elas. A metodologia utilizada para a avaliação dos efluentes líquidos gerados pela UFSM considera a identificação das principais fontes pontuais de emissão desses efluentes e seu posterior monitoramento quali-quantitativo. Para a avaliação da vulnerabilidade à poluição dos recursos hídricos subterrâneos utilizou-se o método G.O.D. que consiste na atribuição de valores que representam as características geológicas e o nível da água subterrânea da área de estudo. O risco qualitativo de poluição da água subterrânea foi determinado pelo cruzamento dos dados de vulnerabilidade com os dados referentes aos efluentes líquidos. Ainda, por meio da aplicação de questionários, realizou-se a caracterização sanitária-ambiental da área externa ao Campus da bacia hidrográfica em questão. Os resultados observados evidenciam que, se considerarmos as cargas poluentes específicas a qualidade da água da bacia de jusante torna-se fortemente dependente das contribuições das cargas despejadas na bacia de montante. Constatou-se que a metodologia do balanço de cargas permite a verificação da influência dos impactos das atividades antrópicas ligadas à degradação da qualidade da água superficial, atribuindo a poluição gerada às diferentes áreas da bacia (montante e jusante), tornando-se um sistema adequado de suporte para o controle da qualidade da água em pequenas bacias hidrográficas. A identificação, espacialização e avaliação das fontes pontuais de emissão de efluentes líquidos integrada com a avaliação da vulnerabilidade à poluição da água subterrânea possibilitaram realizar a hierarquização dos locais mais afetados pela poluição, o que demonstra que, embora simples, a combinação dos métodos apresenta-se útil para os gestores. Os valores da avaliação qualitativa da água subterrânea de alguns poços de abastecimento do Campus evidenciam que existe discordância entre os limites estabelecidos pela legislação vigente, de alguns parâmetros de qualidade da água, e os valores obtidos, ou seja, é possível considerar que a água subterrânea já deve estar sofrendo a interferência das ações humanas desenvolvidas na bacia, relativas aos riscos de poluição.

Submitted by Mariana Dornelles Vargas (marianadv) on 2015-05-28T14:17:29Z No. of bitstreams: 1 Getlb.pdf: 3597932 bytes, checksum: 9c794d7c5c59244cce8b65e3ccd9e1d3 (MD5) / Made available in DSpace on 2015-05-28T14:17:29Z (GMT). No. of bitstreams: 1 Getlb.pdf: 3597932 bytes, checksum: 9c794d7c5c59244cce8b65e3ccd9e1d3 (MD5) Previous issue date: 2013 / Nenhuma / Transações eletrônicas financeiras - em inglês EFT (Electronic Funds Transfer) - representam uma realidade em expansão que impulsiona a aproximação entre consumidores e fornecedores. As transações podem ser originadas de diferentes meios de captura da informação e são transmitidas para um centro de processamento, que decodifica, executa e retorna os resultados no menor tempo possível. Em especial, a presente dissertação de mestrado está enquadrada no dia-a-dia da empresa GetNet e no balanceamento de carga sobre um de seus sistemas de processamento. O sistema em estudo dispõe atualmente de uma arquitetura na qual as transações são recebidas em um nó centralizador, representado por um chaveador Cisco, e são distribuídas para Máquinas Processadoras (MP) segundo o algoritmo de escalonamento Round Robin. Esse algoritmo é adequado para as situações onde as MP são homogêneas e o tempo de rede entre elas e o nó centralizador é também uniforme. Essa configuração pode ser restritiva para um sistema transacional que precisa estar dimensionado para atender uma empresa em expansão geográfica que use MP em diferentes localizações. Em adição, a atuação do algoritmo Round Robin permite que transações sejam repassadas para MP que já possuem alta carga de trabalho ou se encontram indisponíveis. Nesse contexto, essa dissertação descreve uma arquitetura para o sistema transacional chamada GetLB, que proporciona um balanceamento de carga a partir do chaveador com base em monitoração das máquinas de processamento. A infraestrutura GetLB propõe um novo escalonador chamado LL (Load Level). Diferente do Round Robin, para cada transação i, LL calcula n funções LL(i; j), onde j é a MP alvo e n a quantidade das mesmas. Para tal, serão verificadas as suas condições para atender à demanda conforme índices de ocupação de CPU, memória, disco e estado das filas das máquinas processadoras, entre outros. A eficiente combinação desses fatores, para o despacho de transações, configura a contribuição científica do trabalho. Assim como a eficiência em notificar o chaveador quando ocorrem eventos assíncronos no sistema, como parada ou perda de capacidade de processamento de alguma máquina. A arquitetura GetLB também visa proporcionar capacidade de operação com heterogeneidade de máquinas processadoras, possibilitando o uso de máquinas especialistas para certos tipos de transações e a integração de MPs de diferentes redes (domínios administrativos). Os resultados dos testes mostraram que GetLB é mais eficiente que Round-Robin em muitos aspectos, sobressaindo mais em situações de heterogeneidade de recursos e dinamicidade de eventos. Verificou-se também que as notificações acrescentam muito valor ao sistema, auxiliando na manutenção e melhoria contínua da solução. / Electronic financial transactions represents an expanding reality that drives the approach between consumers and suppliers. Transactions can be originated from different information’s capture terminals and are transmitted to a processing center, which decodes, executes and returns the results in the shortest time possible. In particular, this dissertation is framed in the day-to-day operations of GetNet, a network and service provider company, and load balancing on one of its processing systems. The system under study currently has an architecture in which transactions are received at a centralized node, represented by a Cisco switch, and are distributed to machines processors (MP) according to Round Robin scheduling algorithm. This algorithm is suitable for situations where the MP are homogeneous and network transfer time between them and the centralized node is also uniform. This setting can be restrictive for a transactional system that needs to be sized to meet an expanding company and uses geographic MP at different locations. In addition, the performance of Round Robin algorithm enables transactions to be passed to MP who already have high workload or are unavailable. In this context, this work describes an architecture for a transactional system called GetLB, which provides load balancing from the switch based on processing machines’s monitoring. The infrastructure GetLB proposes a new scheduler called LL (Load Level). Unlike the Round Robin, for each transaction i, LL calculates n functions LL (i, j) where j is the target MP and n quantity of machines. This will check their conditions to meet demand as occupancy rate of CPU, memory, disk, and state of the queues of processing machines, among others. The efficient mix of these factors to dispatch transactions, sets the scientific work. As well as the efficiency to notify the switch when asynchronous events occur in the system, such as stopping or loss of processing capacity of some machine. The architecture also aims to provide GetLB operation capability with heterogeneous processing machines, enabling the use of machinery specialists for certain types of transactions and the integration of MPs from different networks (administrative domains). The test results showed that GetLB is more efficient than Round-Robin in many aspects and stand out in case of heterogeneous resources and dynamic events. It was also found that the notifications adds much value to system, assisting in the maintenance and continuous solution’s improvement

在服務經濟的時代，人們為了提升生活品質越來越重視心靈需求而非過往所重視的物質需求。文化創意產業提供的原創性以及內容扮演越來越重要的角色，文化創意產業近年來在世界各國之經濟地位也漸趨重要；本篇論文提出一個透過網際網路提供台灣國立故宮博物院動態展覽的嶄新影音廣播服務--「故宮影音頻道」。故宮影音頻道意圖透過影音多媒體展示，更全方位且完整地呈現中華文物的精緻特質和內涵，以帶給瀏覽者更清晰具體的文物觀賞體驗，以及激發瀏覽者之創意靈感。 故宮影音頻道為了符合高標準的服務品質以及處理來自世界各地使用者的潛在高峰需求而特別設計負載平衡的機制。本篇論文更進一步地探討故宮影音頻道平台後端作業流程的技術挑戰以及展示提供線上影音廣播服務的具備彈性、靈活、分散特性的雲端平台。首先，我們在雲端平台上建立具有處理大量使用者的負載平衡機制的故宮影音頻道。接著我們讓故宮影音頻道上線進行實驗、收集資料及分析。根據實驗的結果，我們為了維持高標準的服務品質應用排隊理論設計了兩階段的服務系統，最後探討在不同電腦及網路環境下，如何利用該服務系統計算出符合服務品質的設定。 / The iPalace Video Channel is a video-based website and provide people around the world a brand new video-broadcasting service on the Internet which introduces relics in National Palace Museum in Taiwan. The iPalace Video Channel is designed to meet the high standard of service quality which users can watch videos without delay and be capable of coping with potential high peak demands from worldwide. In this paper, first, we establish the iPalace Video Channel and an elastic and reliable mechanism via load balancing that is capable of handling potential huge peak-demand of video services. Second, we conduct an experiment by sampling the video-based service in practice and evaluating the presented approach online. Third, from the finding of evaluation, we establish the two phase service system for delivering video services with high standard of service quality. Finally, we discuss the formal queuing model of video services from which the settings of the queuing system that satisfy acceptable service quality could be calculated under various computer and network environments

在使用者較為密集的場合中，常會碰到無線網路壅塞的問題，例如在一個大型會議廳中，常會在各個IEEE 802.11頻道上部署不同的WiFi AP（Access Point），來分散使用者的連線。但是由於IEEE 802.11的連線機制是屬於使用者主導（client driven），只能透過使用者去選定AP進行連線，對於使用者裝置來說,，連線到不同AP的優先順序，是依照接收到不同AP的信號強度（RSSI）作為排序指標。這種做法會讓在空間上使用者分佈不平均的環境中，造成多數使用者UE只連線到少數AP，而其餘AP資源閒置無用的情形。 本論文提出一個IEEE 802.11的負載平衡解決方案，結合藍牙低功耗（Bluetooth Low Energy，BLE）及IEEE 802.11成為一個智慧型AP架構。我們利用藍牙低功耗通訊協定GATT （Generic Attribute Profile）分派AP給不同使用者進行連線，再結合馬可夫鏈平穩狀態分佈（Markov Chains Stationary Distribution）演算法，依照使用者在AP網路拓樸中的歷史分佈紀錄，將多個AP的分派轉化為Erlang-C模型的排隊系統以計算AP分派規則，藉此達到系統的負載平衡。 / Usually, a user crowded space encounters wireless network congestion problem. For example, a large conference hall often deploys different wireless AP (Access Point) on each IEEE 802.11 channel to separate users’ connections. However, since the connection mechanism of IEEE 802.11 is client driven, the AP connection is selected by the user and the selection is according to the received signal strength (RSSI) from different APs. This conventional approach may result in most of the user devices connect to relatively limited number of APs, and the resource of the rest of the APs left unused. This paper proposes a smart AP architecture which is able to manage load balance for IEEE 802.11 Wireless LAN using Bluetooth Low Energy (BLE) GATT (Generic Attribute Profile) protocol in order to appropriately assign AP to different user devices. The core AP assignment algorithm is based on Markov chain stationary distribution. Simulation results show that the proposed BM-MS (BLE Management with Markov-Chains Stationary Load Balance) method outperforms RSSI based method in terms of system throughput and average user data rate.

The Cell processor is an example of the trade-offs made when designing a mass market power efficient multi-core machine, but the machine-exposing architecture and raw communication mechanisms of Cell are hard to manage for a programmer. Cell's design is simple and causes software complexity to go up in the areas of achieving low threading overhead, good bandwidth efficiency, and load balance. Several attempts have been made to produce efficient and effective programming systems for Cell, but the attempts have been too specialized and thus fall short. We present Jack Rabbit, an efficient thread pool work queue implementation, with load balancing mechanisms and double buffering. Our system incurs low threading overhead, gets good load balance, and achieves bandwidth efficiency. Our system represents a step towards an effective way to program Cell and any similar current or future processors. / text

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