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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.
1

Study on the Fuel NOx Formation for Oxidation of Air-Borne Nitrogen-Containing VOC by Regenerative Thermal Oxidizer

Pan, Chung-po 20 July 2005 (has links)
In this study, a regenerative thermal oxidizer (RTO) was used to test the relationship between VOC concentration and nitrogen oxides(NOx) formed, and to estimate its performance. The RTO is electrically heated and contains two 0.152 m ¡Ñ 0.14 m ¡Ñ 1.0 m (L ¡Ñ W ¡Ñ H) beds both packed with gravel particles of around 1.11 cm in average diameter to a height of 1.0 m. The bed has a void fraction of 0.416. Experiments include two phases: (1) tests to find the VOC destruction and NOx formed with DMF only in the influent air stream in the following condition: setting temperature Tset=700-900oC, flowrate Q=0.5-1.0 Am3/min, influent concentration Co=0-500ppm, shift time ts=1.5 min. and before that, to test the effect to thermal recovery efficiency and pressure drop. (2) tests to find the VOC destruction and NOx formed for the air stream with MEK/DMF mixed in the influent air stream in the following condition: setting temperature Tset=600-900oC ,flowrate Q=0.5 Am3/min, influent MEK/DMF ratio =100/100,200/100,500/100(ppm/ppm), shift time ts=1.5 min. and before that, to test the effect to thermal recovery efficiency and pressure drop. Result show : (1)there have no NOx formed in cool-bed with DMF only in the influent air stream. DMF destruction is proportional to influent concentration(low Co > high Co ) and setting temperature(900 > 800 > 700oC).NOx formed is inversely proportional to Co.(2)in the phase two Experiment, DMF destruction is proportional to add MEK in. NOx formed is inversely proportional to Co. MEK/DMF ratio is proportional to (NOx formed/DMF removed) at Tset=600oC,but not closely related during Tset=700-800oC.NO2 formation is significant at Tset=800 oC. (3)Ergun equation is suitable to estimate pressure drop of RTO.
2

Performace study on the treatment of gas-borne chlorohydrocarbons by Regenerative Thermal Oxidizer

Hei, Cheng-Ming 11 July 2002 (has links)
In this study, a pilot-scale regenerative thermal oxidizer (RTO) was used to test its performance for volatile organic compound (VOC) destruction and degree of thermal energy recovery. The purposes were to improve its performance and establish its operation conditions. The RTO is electrically heated and contains two 0.5 m ¡Ñ 0.5 m ¡Ñ 2.0 m (L ¡Ñ W ¡Ñ H) beds both packed with gravel particles of around 1.16 cm in average diameter to a height of 1.48 m. The bed has a void fraction of 0.405. Experiments include two phases: (1) tests to find the degree of energy conservation and the pressure drop for the air stream with no VOC in the influent air stream, and (2) tests to find the degree of VOC destruction with influent air streams containing one of the three VOCs: trichloroethylene, dichloromethane, and dibutyl ether. Intermediates in the course of VOC destruction were also detected in the second phase experiment. Phase one experiment was conducted for the following conditions: superficial gas velocity (evaluated at ambient temperatures of 26-29oC) Ug = 10-20 m/min, bed shift time ts = 1.5 min, and maximum gravel temperature Tmax = 474-778oC. Results show that the RTO has a thermal recovery efficiency R of over 85% and Ug is the main affecting factor. R is inversely proportional to Ug. Gas pressure drop over the bed height is proportional to the average temperature of the bed gravels. In the phase two experiments, Ug of 10-20 m/min, ts of 1.5 min, and Tmax of 475-487 and 758-778oC were used. Results show that over 90% of the influent VOCs were destructed when Tmax was set in the higher range. However, in the lower Tmax, over 80% destruction was obtained only for dibutyl ether and the VOC destruction was not closely related to Ug. For Tmax = 475-487oC and Ug = 10-20 m/min, complete oxidation products of trichloroethylene and dichloromethane are HCl, CO2, and H2O, and the main intermediates are CO, COCl2, and C2Cl4 (detected only for trichloroethylene). For dibutyl ether, complete oxidation products are CO2, and H2O, and the main intermediates are CO, alkenes, alcohol, alkenes, and acetic acid. For Tmax = 758-778oC and Ug = 10-14.5 m/min, complete oxidation products of trichloroethylene and dichloromethane are HCl, CO2, and H2O, and the main intermediates are CO and COCl2. No acetic acid was detected for dibutyl ether in the higher temperature range. An operation cost of US$ 3.33/(1,000 m3 waste gas) was estimated with the RTO operated in the higher temperatures and a flowrate of 2.5 m3/min (Ug = 10 m/min).
3

Multicasting Retransmission Mechanism Using Negative ACK for WiFi Network

Lin, San-Tai 11 September 2012 (has links)
Multicast is an effective technology to save network bandwidth while transmitting data packets in WiFi networks. However, it lacks of a mechanism to recover lost packets. When interference or congestion occurs in wireless networks, the receiver cannot receive complete data. In this Thesis, we propose a multicast retransmission mechanism which integrates NACK in WiFi networks. Also, the sender can dynamically adjust retransmission parameters according to the network status reported from the receiver. To demonstrate our proposed mechanism, three parts are implemented on the Linux platform. First, the RTP header is added in each packet and the buffer is maintained in both the sender and the receiver before the sender can transmit data. Second, a module is installed in the wireless card driver to examine the CRC errors caused by interference. Then the sender can be notified by NACK such that the sender may know the reasons of packet loss and the numbers of dropped packets. Third, the sender utilizes RTCP to calculate RTT and derive RTO. The retransmission time is calculated based on RTO, interferences, and congestion. Finally, our measurement results show that the sender can effectively use multicast retransmission according to various background traffics. Besides, the number of retransmitted packets can be significantly reduced.
4

Effectiveness of Backup and Disaster Recovery in Cloud : A Comparative study on Disk and Cloud based Backup and Disaster Recovery

Kaveti, Akash January 2015 (has links)
Context: Definitive information is what makes enterprises in the contemporary world continuously move up the ladder in today’s world. Hence they need to be always up to date with the latest advancements. A key point in the enterprise structure is Backup and Disaster Recovery, DR system and this has very high scope for development since it can be integrated with a lot of our daily requirements. On account of this, it has a lot of applicability in future for development of technology. Due to this, we have chosen a Fast Moving Consumer Goods Company, FMCG to conduct experimentation on their Backup and DR system. Objectives: In every organization, Backup and DR plays a crucial role in Business Continuity Planning. This work relates to associate backup and recovery plan with an organizational view. And thereby work on its association with Recovery Time Objective, Recovery Point Objective, time taken for backup, time take for recovery and Total Cost of Ownership. Methods: Literature study is the first step to understand present scenario of trending technologies. Hence our understanding led us to conduct an experimental setup where we compared data that was collected in a case study and evaluated its performance of Backup and DR problems that are faced in today’s technology dominated world. Results: In our research, we took various parameters into consideration, which affect performance of an enterprise Backup and DR system. This drove us to assess disk-based and cloud-based Backup and DR plans in the FMCG environment. Conclusions: In conclusion, we summate that even though there have been a lot of theories and research on how Backup and DR is vital, we still lag behind in research work on which the organizations can rely upon to shift towards advanced technologies without risking their competence. With sufficient research on the entrepreneurial environment, we can improve performance enterprises and improve our present knowledge about cloud Backup and DR thereby improving its conventional usage in the present world.
5

Omvänt Förvärv, ett fenomen på First North : en studie i skillnader mellan bolags sätt att ta sig till Nasdaqs tillväxtmarknad

Axelsson, Tobias, Pettersson, Kristoffer January 2015 (has links)
New companies go public through Nasdaqs growth market First North constantly. The reasons for going public are many, and the interest at the moment is big. There are different ways to go public, the most common being the traditional IPO. This study is about the companies that have been listed on Nasdaq First North between 2008 and 2013 through traditional IPO, or by RTO (reverse takeover). The differences between these two ways of going public are that the IPOs are reviewed more thoroughly by Nasdaq and the market. This makes the study interesting, as the RTOs go public in a faster way, and avoid the review from outside parties largely. In this study you will see whether there is a difference in investing in either group of companies, from a shareholders point of view. In the study, we establish that there is no difference in the performance between the two groups of companies. However, we do see clear differenes between the companies development, not from a share perspective, but in other interesting perspectives such as takeovers, listing changes, bankruptcy, and delistings. / På Nasdaqs tillväxtmarknad First North sker ständigt nya introduktioner av företag. Anledningarna till börsnoteringarna är många, och intresset är i skrivande stund stort för att introduceras på börsen. Det finns olika sätt att introduceras på börsen, där det vanligast förkommande är genom en så kallad IPO-process. Denna studie utgår från bolag som har börsnoterats på Nasdaq First North under tidsperioden 2008-2013 genom IPO och RTO (omvända förvärv). Skillnaderna mellan dessa introduktioner är att IPO-bolagen granskas i högre grad av Nasdaqoch marknaden i övrigt inför introduktionen. Detta gör det intressant då RTO-bolagen kommer snabbare in på börsen och undviker granskningen från utomstående parter till stordel. I studien får du ur ett aktieägarperspektiv svar på om det är värt att investera i större utsträckning i någon av kategorierna, samt aktiernas utveckling i relation till deras branschindex på Nasdaq First North. I studien konstaterar vi att RTO-bolagen inte presterar sämre än IPO-bolagen om man ser till branschindex. Vi ser dock genomgående att det är tydliga skillnader vad gäller företagens utveckling, men inte ur ett aktiekursperspektiv utan snarare till andra intressanta aspekter såsom uppköp, listbyten, konkurser samt avnoteringar.
6

SCTP and Diameter Parameters for High Availability in LTE Roaming

Xiong, Xuelin January 2015 (has links)
Today mobile network operators utilize IP Packet exchange (IPX) carriers to interconnect their networks with other operators. Mobile network operators are free to choose one IPX carrier for their data traffic and another for their control traffic. This thesis examines the case of control traffic, specifically Stream Control Transmission Protocol (SCTP) carrying Diameter protocol traffic arising from users roaming from their home Long Term Evolution (LTE) network to another operator’s LTE network. The thesis project aims to identify a set of SCTP parameter configurations that can provide improved application/service level availability between two Diameter nodes in different network connectivity environments, specifically for IPX carriers who are Diameter service providers. These service providers provide Diameter connectivity for their customers who are mobile network operators. These mobile network operators in turn provide LTE roaming services to their customers. Unfortunately, applying the ‘One size fits all’ configuration recommendations given in the SCTP documentation is unsuitable for different network environments. In addition, the amount of Diameter signaling traffic is growing at a very rapid rate. Therefore, it is valuable to identify suitable parameter selection criteria for Diameter service providers to ensure 100% Diameter connectivity reliability for their customers. In this thesis project, author investigated how tuning SCTP parameter values affect Diameter message transmission in terms of Round Trip Delay and identified its determining parameters for packet loss recovery performance. Both IPX carriers and mobile network operators may use these values as reference when attempting to ensure high availability of Diameter transmissions under reliable, semi reliable, and unreliable network transport conditions. / Mobilnätsoperatörer använder sig av IP Packet exchange (IPX) tjänstetillhandahållare för att koppla ihop sina nät med andra operatörers nät. Mobilnätsoperatörer kan fritt välja en IPX tjänstetillhandahållare för sin datatrafik och en annan för sin kontrolltrafik. Denna uppsats undersöker fallet för kontrolltrafik, specifikt Stream Control Transmission Protocol (SCTP) kommunikationsprotokoll för Diameter protocol-trafik vid användares roaming från sitt Long Term Evolution (LTE)-hemmanät till en annan operatörs LTE-nät. Examensarbetet avser etablera en uppsättning av SCTP-parameterkonfigurationer som ger förbättrad applikations-/tjänstetillgänglighetsnivå mellan två Diameter-noder i olika nätmiljöer, särskilt för IPX tjänstetillhandahållare som är Diameter tjänstetillhandahållare.  Dessa tjänstetillhandahållare erbjuder Diameter-konnektivitet till sina kunder, som är mobilnätsoperatörer. Dessa mobilnätsoperatörer tillhandahåller i sin tur LTE-roamingtjänster till sina kunder. Tyvärr är det olämpligt att tillämpa de enhetliga konfigurationsrekommendationer, som ges i SCTP- och Diameter-protokollens dokumentation, i olika nätmiljöer. Samtidigt ökar Diameter-signaleringstrafiken mycket snabbt. Därför är det värdefullt att identifiera lämpliga parameterkriterier för Diameter-tjänstetillhandahållare att säkerställa 100% tillförlitlig Diameter-tillgänglighet för sina kunder. I detta examensarbete har författaren undersökt hur trimning av SCTP-parametervärden påverkar Diameter-meddelandeöverföring vad avser överföringstiden tur- och retur, och identifierat de avgörande parametrarna för återställande av paketförluster. Både IPX tjänstetillhandahållare och mobilnätsoperatörer kan använda dessa värden som referens för att åstadkomma hög tillgänglighet för Diameter-överföring vid tillförlitliga, halvtillförlitliga och otillförlitliga nättransportförutsättningar.
7

Real Time Evolution (RTE) for on-line optimisation of continuous and semi-continuous chemical processes

Sequeira, Sebastián Eloy 15 July 2003 (has links)
En general, el control de procesos es muy eficiente cuando el punto de operación deseado ha sido determinado a priori y el sistema tiene capacidad suficiente para responder a las perturbaciones. Mientras el control de procesos es requerido a fin de regular algunas variables de proceso, la aplicación de tal técnica puede no ser apropiada para todas las variables significativas. En algunos casos, el punto optimo de operación cambia debido al efecto combinado de perturbaciones internas y externas por lo que un sistema de control prefijado puede no responder adecuadamente a los cambios. Cuando ciertas condiciones son satisfechas, la optimización en-línea surge como una alternativa adecuada para ajustarse a ese optimo cambiante.A fin de "perseguir" este optimo móvil, la optimización en-línea resuelve en forma periódica problemas de optimización, usando datos que vienen directamente de la planta y un modelo el cual es actualizado continuamente. La aplicación mas frecuente de la optimización en-línea corresponde a la categoría de procesos continuos. Esto se debe principalmente a que los modelos de estado estacionario son mas simples y fáciles de desarrollar y validar, además de que los procesos continuos tienen normalmente asociado elevada producción y por ende, pequeñas mejoras en la eficiencia del proceso se traducen en importantes ganancias. Sin embargo, aunque el uso de modelos al estado estacionario simplifica enormemente las tareas de modelización, hace emerger ciertos aspectos ligados a la validez de la hipótesis de un estado estacionario.Comenzaron a surgir varias aplicaciones a gran escala de la optimización en-línea, pero, si bien varios vendedores ofrecen productos y servicios en este área, la mayoría de las aplicaciones industriales abordan problemas de control avanzado, dejando a la optimización en un segundo plano. Los industriales han reportado que después de cuatro décadas ha tenido lugar una mejora progresiva en la metodología llevada a cabo en la optimización en-línea, pero que siguen estando presente los puntos débiles originales. Tales aspectos están directamente relacionados con la detección del estado estacionario (o las frecuencias de las perturbaciones) y la optimización en si misma.Los objetivos de la presente tesis están dirigidos a solventar parcialmente tales puntos débiles de la metodología actual. Como resultado, se propone una estrategia alternativa que saca ventaja de las mediciones y busca una mejora continua en lugar de una optimización formal. Se muestra que tal estrategia resulta muy efectiva y puede no solo ser aplicada para la optimización de puntos de consigna, pero también para tomar (en-línea) las decisiones discretas necesarias en procesos que presentan degradación (aspecto normalmente resuelto usando programación matemática).La estructura de la tesis es como sigue. El primer capitulo explica las principales motivaciones y objetivos del trabajo, mientras que el capitulo 2 consiste en una revisión bibliográfica que abarca, hasta cierto punto, los tópicos y funcionalidades mas importantes asociados a la optimización en-línea. Luego, los capítulos 3 y 4 presentan la estrategia propuesta a través de dos metodologías para la optimización en-línea, lo cual es la contribución mas importante de la tesis. El primero, (capitulo 3) se centra en la persecución de un optimo que se mueve por el efecto combinado de perturbaciones externas e internas. Por otro lado, en el capitulo 4 se explica una metodología paralela, concebida para procesos que presentan desempeño decreciente con el tiempo y requieren decisiones discretas en relación a acciones de mantenimiento. Ambos capítulos incluyen una primera parte, mas bien teórica, y una segunda parte dedicada a la validación usando casos de referencia. Luego, el capitulo 5 describe la aplicación de tales metodología sobre dos escenarios industriales, con la intención de complementar los resultados obtenidos sobre los casos académicos. Posteriormente, el capitulo 6 aborda dos problemas asociados a la implementación: la influencia de los parámetros ajustables y la arquitectura del software usada. Finalmente, el capitulo 7 resume las principales conclusiones y observaciones de la tesis. / In general, process control is very effective when the desired operation point has been determined from prior analysis and the control system has sufficient time to respond to disturbances. While process control is required for regulating some process variables, the application of these methods may be not appropriate for all important variables. In some situations, the best operating conditions change because of the combined effect of internal and external disturbances, and a fixed control design may not respond properly to these changes. When certain conditions are met, on-line optimisation becomes a suitable choice for tracking the moving optimum.In order to "pursue" that moving optimum, on-line optimisation solves periodically optimisation problems using data coming directly form the plant and a continuously updated model. The most common use of on-line optimisation corresponds to the continuous processes category. This is mainly owed to that steady state models are simpler and easier to develop and validate, besides that continuous processes have commonly high production rates, thus small relative improvements in the process efficiency originates significant economic earnings. Nevertheless, although the use of steady state models greatly simplifies the modelling task, it raises other issues associated with the validity of the steady state assumption. Large-scale applications of on-line optimisation started to spread, however, even when several vendors offer products and services in the area, most of the application address advanced control issues while on-line optimisation is released to a second plane. Industry practitioners have reported that after four decades there has been a progressive improvement in the on-line optimisation methodology, but the same initial weakness or more generally speaking some common causes of poor performance still remain. These issues are directly related with the steady state detection (or disturbance frequency) and the optimisation itself.The objectives of this thesis work are then directed to overcome at least partially the weak points of the current approach. The result is the proposal of an alternative strategy that takes fully advantage of the on-line measurements and looks for periodical improvement rather than a formal optimisation. It is shown how the proposed approach results very efficient and can be applied not only for set-point on-line optimisation but also for taking the on-line decision required in processes that presents decaying performance (aspect typically solved of-line via mathematical programming). The thesis is structured as follows. The first chapter explains the main motivations and objectives of the work, while chapter 2 consists in a literature review that addresses, to some extension, the most significant issues around the on-line optimisation functionality. After that, chapter 3 and chapter 4 introduce two methodologies that use the proposed strategy for on-line optimisation, which is the main thesis contribution. The first one (in chapter 3) focuses in tracking fast moving optima, which is caused mainly by the combined effect of external and internal disturbances. On the other hand, a parallel methodology is explained in 4, conceived for processes that present decaying performance and that require discrete decision related to maintenance actions. Both chapters include a first part, rather theoretical, and a second part devoted to the validation over typical benchmarks. Then, chapter 5 describes the application of such methodologies over two existing industrial scenarios, in order to complement the results obtained using the benchmarks. After that, chapter 6 addresses two issues related to the implementation aspects: the influence of the adjustable parameters of the proposed procedure and the software architectures used. Finally, chapter 7 draws conclusions and main observations.
8

Hybrid Model for Optimization Of Crude Distillation Units

Fu, Gang 11 1900 (has links)
Planning, scheduling and real time optimization (RTO) are currently implemented by using different types of models, which causes discrepancies between their results. This work presents a single model of a crude distillation unit (preflash, atmospheric, and vacuum towers) suitable for all of these applications, thereby eliminating discrepancies between models used in these decision processes. Hybrid model consists of volumetric and energy balances and partial least squares model for predicting product properties. Product TBP curves are predicted from feed TBP curve, operating conditions (flows, pumparound heat duties, furnace coil outlet temperatures). Simulated plant data and model testing have been based on a rigorous distillation model, with 0.5% RMSE over a wide range of conditions. Unlike previous works, we do not assume that (i) midpoint of a product TBP curve lies on the crude distillation curve, and (ii) midpoint between the back-end and front-end of the adjacent products lies on the crude distillation curves, since these assumptions do not hold in practice. Associated properties (e.g. gravity, sulfur) are computed for each product based on its distillation curve. Model structure makes it particularly amenable for development from plant data. High model accuracy and its linearity make it suitable for optimization of production plans or schedules. / Thesis / Master of Applied Science (MASc)
9

L'évaluation de la performance des réseaux territorialisés d'organisations : le cas des pôles de compétitivité français / Performance evaluation of clusters : the french "pôles de compétitivité" case

Lallemand, Anne-Sophie 24 October 2013 (has links)
L’évaluation de la performance des réseaux territoriaux d’organisations (RTO), quel que soit leur forme (clusters, districts industriels, pôles de compétitivité, etc.) est un champ de recherche encore émergent, situé à la croisée des préoccupations des managers de réseaux, des pouvoirs publics et du monde académique. La littérature, bien que protéiforme, s’accorde à souligner l’influence des caractéristiques structurelles et des facteurs de contingence sur l’évaluation que ces réseaux font de leur performance, mais elle ne prend pas en compte, pour l’instant, l’influence de leur environnement institutionnel et donc les apports possibles de la théorie néo-institutionnelle. C’est à partir de l’identification de cette lacune de la littérature que nous avons bâti notre réflexion, dans le dessein de comprendre s’il existe un tel impact et, dans ce cas, d’analyser les répercussions de l’environnement institutionnel des RTO sur l’évaluation de leur performance. Nous avons choisi de focaliser notre analyse sur la nature et l’intensité des pressions institutionnelles subies, les réactions stratégiques suscitées ainsi que les logiques institutionnelles à l’oeuvre. La partie empirique de notre recherche se base sur un type précis de RTO, à savoir les pôles de compétitivité français. Après un travail exploratoire, fondé sur l’analyse de plus de 300 indicateurs de performance utilisés au sein des pôles, la phase intensive de notre recherche repose sur des entretiens réalisés auprès des directeurs de 37 pôles de compétitivité (soit 52% de l’ensemble des pôles de compétitivité français), et ce par une approche qualitative fondée sur une analyse par catégories conceptualisantes. Trois niveaux de résultats sont proposés. Nous identifions tout d’abord les pressions institutionnelles subies par les pôles de compétitivité ainsi que leur impact sur l’évaluation de la performance menée en leur sein. Puis, l’analyse met en exergue les stratégies que les pôles adoptent vis-à-vis de ces pressions. Enfin, à partir de la construction d’idéaux-types, nous montrons l’existence de deux logiques institutionnelles au sein de ce champ. / Evaluating the effectiveness of different types of clusters (e.g. clusters, industrial districts or centres of excellence (French pôles de compétitivité) is a newly emerging field of research, and is the convergent point for the common concerns of cluster managers, the public authorities and academic circles. Although varied in its approach, the available literature nevertheless highlights the influence of structural features, as well as specific situational factors, on self-evaluation by clusters. However, for the moment, it does not take into consideration the influence of their institutional environment and, therefore, the possible inputs from neo-institutional theory. This gap in the literature was the starting point for our analysis aimed at understanding whether there is such an effect and, if so, analysing the impact of the institutional environment on the evaluation of clusters. Our approach focuses on the French clusters known as “pôles de compétitivité”. A preliminary analysis considered more than 300 specific performance indicators used by the French clusters and the body of our present research is based on 37 interviews with directors of « pôles de compétitivité » (52% of all such clusters). Three levels of result are proposed. Firstly, we identify the institutional pressures on these clusters and their impact on self-evaluation. Then, the analysis highlights the strategies used by the clusters in response to this pressure. Finally, through a proposition of typical ideal patterns, we demonstrate the existence of two different institutional rationales in this field.
10

A multi-agent software system for real-time optimization of chemical plants. / Sistema multi-agentes de software para a otimização em tempo real de plantas quí­micas.

Estrada Martínez, Elyser 09 March 2018 (has links)
Real-Time Optimization (RTO) is a family of techniques that pursue to improve the performance of chemical processes. As general scheme, the method reevaluates the process conditions in a frequent basis and tries to adjust some selected variables, taking into account the plant state, actual operational constraints and optimization objectives. Several RTO approaches have born from the academy research and industrial practices, at the same time that more applications have been implemented in real facilities. Between the main motivations to apply RTO are the dynamic of markets, the seek for quality in the process results and environmental sustainability. That is why the interest on deeply understand the phases and steps involved in an RTO application has increased in recent years. Nevertheless, the fact that most of the existing RTO systems have been developed by commercial organizations makes it difficult to meet that understanding. This work studies the nature of RTO systems from a software point of view. Software requirements for a generic system are identied. Based on that, a software architecture is proposed that could be adapted for specfic cases. Benefits of the designed architecture are listed. At the same time, the work proposes a new approach to implement that architecture as a Multi-Agent System (MAS). Two RTO system prototypes were developed then, one for a well-know academic case study and the other oriented to be used in a real unit. The benefits of the MAS approach and the architecture, for researching on the RTO field and implementation on real plants, are analyzed in the text. A sub-product of the development, a software framework covering main concepts from the RTO ontology, is proposed as well. As the framework was designed to be generic, it can be used in new applications development and extended to very specific scenarios. / Otimização em Tempo Real (OTR) é uma família de técnicas que buscam melhorar o desempenho dos processos químicos. Como esquema geral, o método reavalia frequentemente as condições do processo e tenta ajustar algumas variáveis selecionadas, levando em considera ção o estado da planta, restrições operacionais e os objetivos da otimização. Várias abordagens para OTR t^em surgido da pesquisa acadêmica e das práticas industriais, ao mesmo tempo em que mais aplicações têm sido implementadas em plantas reais. As principais motivações para aplicar OTR são: a dinâmica dos mercados, a busca de qualidade nos resultados dos processos e a sustentabilidade ambiental. É por isso que o interesse em entender as fases e etapas envolvidas em uma aplicação OTR cresceu nos últimos anos. No entanto, o fato de que a maioria dos sistemas OTR em operação foram desenvolvidos por organizações comerciais dificulta o caminho para chegar nesse entendimento. Este trabalho analisa a natureza dos sistemas OTR desde o ponto de vista do software. Os requerimentos para um sistema genérico são levantados. Baseado nisso, é proposta uma arquitetura de software que pode ser adaptada para casos específicos. Os benefícios da arquitetura projetada foram listados. Ao mesmo tempo, o trabalho propõe uma nova abordagem para implementar essa arquitetura: Sistema Multi-Agentes (SMA). Dois protótipos de sistema OTR foram desenvolvidos. O primeiro aplicado num estudo de caso bem conhecido na literatura acadêmica. O segundo voltado para ser usado em uma unidade industrial. Os benefícios da abordagem SMA e da arquitetura, tanto na pesquisa relacionada com OTR, quanto na implementação em plantas reais, são analisados no texto. Um arcabouço de software que abrange os principais conceitos da ontologia OTR é proposto como resultado derivado do desenvolvimento. O arcabouço foi projetado para ser genérico, possibilitando seu uso no desenvolvimento de novas aplicações OTR e sua extensão a cenários muito específicos.

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