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GIPP: GPU-based Path Planning and Navigation Mesh Generation : A Novel Automatic Navigation Mesh Generator and Path Planning Algorithm using the Rendering PipelineLundin, Elliot, Mathiasson, Felix January 2024 (has links)
Background. Geometry-Independent Path Planning (GIPP) can be done by generating a navigation mesh and computing paths on that mesh in real-time for parallel and dynamic path planning. However, many of the existing algorithms are not suitable for the Graphics card, therefore a new path planning algorithm is created. Hardware Accelerated Line Of Sight (HALOS) performs parallel path planning on grid maps in real-time using the GPU. Objectives. This thesis aims to implement an automatic navigation mesh generation algorithm using the GPU rendering pipeline and a GPU-bound path planning algorithm for a grid-based map. The proposed method should generate accurate paths and run in real-time. To gather results, the methods are measured in run-time on different types of hardware and scenarios. Methods. Multiple experiments are conducted. A navigation mesh is generated in real-time using the rendering pipeline of the GPU. In addition, a novel path planning algorithm generates paths in real-time using the GPU by utilizing line of sight on the navigation mesh. GIPP is a multi-source, single-destination algorithm. The path planning is done parallel and dynamically to navigate around moving obstacles. Results. The experiments show that GIPP can generate a dynamic navigation mesh in real-time. However, the coverage of GIPP is poor, and some resolutions of GIPP result in agents being unable to reach the goal node. The performance effect of dynamic worlds on path planning is not noticeable compared to static worlds. Conclusions. The proposed method can perform real-time navigation mesh generation and path planning. Different resolutions of GINT show inconsistencies in the length of the path generated. This method, GIPP, is well suited for complex, dynamic, single-floor meshes that more traditional navigation mesh generators are not guaranteed to handle in real-time. The main performance bottleneck for GIPP is the number of layers created during path planning. / Bakgrund. Geometrioberoende vägplanering (GIPP) kan utföras genom att generera ett navigationsnät och beräkna vägar på detta nät i realtid för parallell och dynamisk vägplanering. Många vägplaneringsalgoritmer kan inte köras i realtid på grafikkortet. Därför har Hardware Accelerated Line Of Sight (HALOS) skapats, vilket utför parallell vägplanering i realtid med hjälp av GPU:n. Mål. Denna avhandling syftar till att implementera en automatisk algoritm för generering av navigationsnät med hjälp av GPU:ns renderingspipeline och implementera en GPU-bunden vägplaneringsalgoritm för en rutbaserad karta. Den föreslagna metoden genererar vägar och körs i realtid. För att samla in resultat mäts metoderna i körtid på olika typer av hårdvara och scenarier. \newline\textbf{Metoder.} Flertalet experiment utförst på GIPP. Ett navigationsnät genereras i realtid med hjälp av GPU:ns renderingspipeline och en ny vägplaneringsalgoritm genererar vägar i realtid med hjälp av sikten längs navigationsnätet. Denna algoritm har flera källor med en destination (MSSD) för att hantera ett stort antal agenter. Vägplaneringen görs parallellt och dynamiskt för att navigera runt rörliga hinder. Resultat. Experimenten visar att GIPP kan generera ett navigationsnät i realtid. GIPP har dock dålig precision när det gäller att generera effektiva vägar mot målet. Vissa upplösningar leder till att agenter inte når slutmålet. Dynamiska världar har omärkbar påverkan på prestandan i jämförelse med statiska världar när det gäller vägplanering. Slutsatser. Den föreslagna metoden kan utföra navigationsnätsgenerering och vägplanering i realtid. Olika upplösningar av navigationsnätet visar att vägplanering har olikeheter i avstånd. Denna metod, GIPP, lämpar sig väl för komplexa, dynamiska, enplansvärldar. GIPPs flaskhals i prestandan är mängden lager som skapas under vägplaneringen.
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Дигитална мамографија и томосинтеза у детекцији и радиолошкој БИ РАДС категоризацији туморских лезија дојке / Digitalna mamografija i tomosinteza u detekciji i radiološkoj BI RADS kategorizaciji tumorskih lezija dojke / Digital mammography and tomosynthesis in BIRADS lesions characterizationPrvulović Bunović Nataša 28 April 2015 (has links)
<p>Циљ ове студије је да се упореди дијагностичкa значајност 2Д и 2Д+3Д мамографије у детектовању тумора дојке. Испитивали смо 864 дојки у 740 пацијенткиња. Студија је спроведена у току рутинског рада у Центру за имиџинг дијагностику Институту за онкологију Војводине. 2Д + 3Д мамографија су начињене појединачно или у истом акту снимања као комбо опција на Selenia Dimensions апарату произвођача фирме Холоџик. Радиолошки извешатаји су класификовани у категорије 1-5 према АЦР БИ РAДС-у. Патохистолошка верификација је вршена у свих суспектних промена или у току њиховог праћења . Све пацијенткиње са уредним налазом или мамографски уочених бенигних промена су радиолошки праћене најкраће током 2 године. Уочено је 103 малигне лезије у дојкама класификованих као БИ РАДС 4, 5 на дигиталној мамографији и у 22 дојке чије су промене класификоване као БИ РАДС 1-3, током праћења или прегледа дојки помоћу других модалитета. На 2Д + 3Д мамографији малигните је потврђен у 125 дојке од којих је 118 класификовано као БИ РАДС 4,5 и у 7 дојки чује су промене категорисане у БИРАДС 1-3. Постоји статистички значајна разлика у дистрибуцији малигних налаза у односу на подгрупе Студија је показала 20% лажно негативних налаза на 2Д, а 5,6% на 2Д + 3Д модалитету прегледа дојки. Осетљивост у откривању рака у овој студији износи 82,4% на 2Д и 94,4% на 2Д+3Д методи прегледа, док је специфичност 90,5% и 92,0%, респективно. ППВ је већа за 2Д + 3Д технику прегледа , износи 66,7%, као и негативна предиктивна вредност која износи 99,0%. У 172 случаја (19, 9%) налази 2Д мамографије се не уочавају на 3Д техници прегледа и сматрају се последицом структурне или анатомске „буке“. Већина не -сталних налаза (85%) је класификовано као фокална асиметрија. У овој студији 500 дојки је класификовано према АЦР структури у масне (АЦР 1) или дифузне фибро-гландуларне (АЦР 2), а преосталих 264 је било хетеродензно (АЦР 3) и значајно дензно (АЦР 4). Статистички значајна разлика није показана приликом дистрибуције малигних налаза у поређењу са подгрупама дојки начињеним према њиховој густини - складу са правилима АЦР-а. Укупна тачност теста износи 89,4% за 2Д и 92,4% за 2Д + 3Д мамографију. Предиктивне вредности добијене за 2Д + 3Д мамографију су боље од оних које се односе само на 2Д мамографију, што је резултат њене веће осетљивости и шире могућности карактеризације промена. Варијабилност у интерпретацији налаза међу два радиолога је је ниска, показано је слагање у интершпретавцији евалуираних мамограма у 94.1% случајева.</p> / <p>Cilj ove studije je da se uporedi dijagnostička značajnost 2D i 2D+3D mamografije u detektovanju tumora dojke. Ispitivali smo 864 dojki u 740 pacijentkinja. Studija je sprovedena u toku rutinskog rada u Centru za imidžing dijagnostiku Institutu za onkologiju Vojvodine. 2D + 3D mamografija su načinjene pojedinačno ili u istom aktu snimanja kao kombo opcija na Selenia Dimensions aparatu proizvođača firme Holodžik. Radiološki izvešataji su klasifikovani u kategorije 1-5 prema ACR BI RADS-u. Patohistološka verifikacija je vršena u svih suspektnih promena ili u toku njihovog praćenja . Sve pacijentkinje sa urednim nalazom ili mamografski uočenih benignih promena su radiološki praćene najkraće tokom 2 godine. Uočeno je 103 maligne lezije u dojkama klasifikovanih kao BI RADS 4, 5 na digitalnoj mamografiji i u 22 dojke čije su promene klasifikovane kao BI RADS 1-3, tokom praćenja ili pregleda dojki pomoću drugih modaliteta. Na 2D + 3D mamografiji malignite je potvrđen u 125 dojke od kojih je 118 klasifikovano kao BI RADS 4,5 i u 7 dojki čuje su promene kategorisane u BIRADS 1-3. Postoji statistički značajna razlika u distribuciji malignih nalaza u odnosu na podgrupe Studija je pokazala 20% lažno negativnih nalaza na 2D, a 5,6% na 2D + 3D modalitetu pregleda dojki. Osetljivost u otkrivanju raka u ovoj studiji iznosi 82,4% na 2D i 94,4% na 2D+3D metodi pregleda, dok je specifičnost 90,5% i 92,0%, respektivno. PPV je veća za 2D + 3D tehniku pregleda , iznosi 66,7%, kao i negativna prediktivna vrednost koja iznosi 99,0%. U 172 slučaja (19, 9%) nalazi 2D mamografije se ne uočavaju na 3D tehnici pregleda i smatraju se posledicom strukturne ili anatomske „buke“. Većina ne -stalnih nalaza (85%) je klasifikovano kao fokalna asimetrija. U ovoj studiji 500 dojki je klasifikovano prema ACR strukturi u masne (ACR 1) ili difuzne fibro-glandularne (ACR 2), a preostalih 264 je bilo heterodenzno (ACR 3) i značajno denzno (ACR 4). Statistički značajna razlika nije pokazana prilikom distribucije malignih nalaza u poređenju sa podgrupama dojki načinjenim prema njihovoj gustini - skladu sa pravilima ACR-a. Ukupna tačnost testa iznosi 89,4% za 2D i 92,4% za 2D + 3D mamografiju. Prediktivne vrednosti dobijene za 2D + 3D mamografiju su bolje od onih koje se odnose samo na 2D mamografiju, što je rezultat njene veće osetljivosti i šire mogućnosti karakterizacije promena. Varijabilnost u interpretaciji nalaza među dva radiologa je je niska, pokazano je slaganje u interšpretavciji evaluiranih mamograma u 94.1% slučajeva.</p> / <p>The aim of this study was to compare diagnostic importance of 2D and 2D+3D diagnostic mammography in breast tumor detection. We evaluated 864 breasts in 740 patients. Study was performed in Diagnostic Imaging Center at Oncology Institute of Vojvodina. 2D+3D mammography were performed during single procedure or via combo option at Selenia Dimensions unit, Hologic, BE. Radiological findings were classified in categories 1-5 according to ACR BIRADS. Pathohistologic verification was obtained in all suspicious findings or after follow up studies. All other patients with mammographic normal findings or benign findings were fallowed up during 2 years period or longer. We detected malignant lesions in 103 breasts classified as BIRADS 4,5 at digital mammography, and in 22 breasts classified as BIRADS 1-3 after followed up or diagnosed by other imaging modalities. At 2D+3D mammography malignancy was confirmed in 125 breasts, 118 classified as BIRADS 4,5 and in 7 breasts classified as BIRADS 1-3. There is statistically significant difference (p<0.001) in distribution of malignant findings compared to the subgroups classified according to 2D mammography. There was 20% false negative findings on 2D, and 5.6% on 2D+3D modality. Sensitivity in cancer detection in this study is 82.4% and 94.4% for 2D and 2D+3D mammography, while specificity is 90.5% and 92.0%, respectively. PPV is higher for 2D+3D technique (66.7%), as well as negative predictive value (99.0%). In 172 cases (19, 9%) 2D mammography findings did not persist on 3D mammography and were considered as structural or anatomical noise. The majority of the non-persistent findings (85%) were classified as asymmetric focal density. In this study 500 breast were classified according to ACR as fatty (ACR 1) or scattered fibroglandular densities (ACR 2), and the remaining 264 had heterogeneously (ACR 3) and extremely dense breasts (ACR 4). Statistically significant difference (p<0.001) was not shown in distribution of malignant findings compared to the subgroups of density structure according to ACR. Overall accuracy of the test was 89.4% and 92.4% for 2D and 2D+3D mammography, respectively. Predictive values obtained in 2D+ 3D mammography are better than those for 2D mammography alone, as a result of its higher sensitivity and better possibility of lesion characterization. Interobserver variability is low, there is an agreement between two radiologist between two radiologic interpretations in 94.1% cases.</p>
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Progressive Meshes / Progressive MeshesValachová, Michaela January 2012 (has links)
This thesis introduces a representation of graphical data, progressive meshes, and its fields of usage. The main part of this work is mathematical representation of progressive meshes and the simplification algorithm, which leads to this representation. Examples of changes in progressive mesh representation are also part of this thesis, along with few examples. The result is an application that implements the calculation of the Progressive Meshes model representation
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A posteriori error estimation for anisotropic tetrahedral and triangular finite element meshesKunert, Gerd 08 January 1999 (has links)
Many physical problems lead to boundary value problems for partial differential equations, which can be solved with the finite element method. In order to construct adaptive solution algorithms or to measure the error one aims at reliable a posteriori error estimators. Many such estimators are known, as well as their theoretical foundation.
Some boundary value problems yield so-called anisotropic solutions (e.g. with boundary layers). Then anisotropic finite element meshes can be advantageous. However, the common error estimators for isotropic meshes fail when applied to anisotropic meshes, or they were not investigated yet.
For rectangular or cuboidal anisotropic meshes a modified error estimator had already been derived. In this paper error estimators for anisotropic tetrahedral or triangular meshes are considered. Such meshes offer a greater geometrical flexibility.
For the Poisson equation we introduce a residual error estimator, an estimator based on a local problem, several Zienkiewicz-Zhu estimators, and an L_2 error estimator, respectively. A corresponding mathematical theory is given.For a singularly perturbed reaction-diffusion equation a residual error estimator is derived as well. The numerical examples demonstrate that reliable and efficient error estimation is possible on anisotropic meshes.
The analysis basically relies on two important tools, namely anisotropic interpolation error estimates and the so-called bubble functions. Moreover, the correspondence of an anisotropic mesh with an anisotropic solution plays a vital role.
AMS(MOS): 65N30, 65N15, 35B25
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Hybrid particle-element method for a general hexahedral meshHernandez, Roque Julio 02 November 2009 (has links)
The development of improved numerical methods for computer simulation of high velocity impact dynamics is of importance in a variety of science and engineering fields. The growth of computing capabilities has created a demand for improved parallel algorithms for high velocity impact modeling. In addition, there are selected impact applications where experimentation is very costly, or even impossible (e.g. when certain bioimpact or space debris problems are of interest). This dissertation extends significantly the class of problems where particle-element based impact simulation techniques may be effectively applied in engineering design. This dissertation develops a hybrid particle-finite element method for a general hexahedral mesh. This work included the formulation of a numerical algorithm for the generation of an ellipsoidal particle set for an unstructured hex mesh, and a new interpolation kernel for the density. The discrete model is constructed using thermomechanical Lagrange equations. The formulation is validated via simulation of published impact experiments. / text
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Adaptyvieji algoritmai elipsiniams uždaviniams / Adaptive algorithms for elliptic problemsBugajev, Andrej 14 June 2011 (has links)
Pagrindinis šio darbo tikslas - sudaryti efektyvius skaitinius algoritmus elipsinio tipo uždaviniams spręsti. Galiorkino metodu sprendžiami du uždaviniai: vienmatis pasienio sluoksnio uždavinys ir dvimatis elipsinis uždavinys su L formos geometrijos sritimi. Algoritmų efektyvumui gerinti naudojami adaptyvieji tinklai, sudaryti remiantis aposterioriniais įverčiais. Darbe parodyta kaip iš dualiųjų įverčių teorijos gauti Bakhvalovo tinklą. Taip pat parodytas Šiškino tinklo ryšys su Bakhvalovo tinklu. Iš aposteriorinių įverčių teorijos gautos σ parametro (jis naudojamas Bakhvalovo ir Šiškino tinkluose) reikšmės, kurios skiriasi skirtinguose normose. Teorinės σ reikšmės patvirtintos skaitiniais eksperimentais, jas galima naudoti kaip rekomendacija sudarant Šiškino arba Bakhvalovo tinklus. Remiantis aposterioriniais įverčiais sudaryta Šiškino tinklo modifikacija, kuri prisitaiko prie šaltinio ir reakcijos funkcijų ypatumų, atlikti skaitiniai eksperimentai. Aposteriorinių įverčių metodas pritaikytas dvimačiam uždaviniui, atlikti eksperimentai, ištirtas adaptyviojo tinklo efektyvumas. / The objective of this paper is to construct effective numerical algorithms for elliptic problems. We use Galerkin method to solve two problems: a one-dimensional boundary layer problem and the two-dimensional elliptic problem with a specific geometry of L form. To optimize computations we use adaptive meshes that are constructed from aposteriori error estimates. We show how to derive Bakhvalov mesh from aposteriori estimates. Also we show the relation between Shishkin and Bakhvalov meshes. From aposteriori estimates we derive the exact values of σ parameter(which is used in Shishkin and Bakhvalov meshes), which depends on a norm in which we calculate the error. Theoretical σ values were confirmed by calculations, they can be used as a recommendation, when a problem is being solved using Shishkin or Bakhvalov meshes. Also we use duality-based aposteriori error estimation to construct a modification of Shishkin mesh, which use additional information about parameters in differential equation, we experimentally compare this mesh with the original(Shishkin) one. We apply aposteriori error estimation technique to a two-dimensional problem and investigate efficiency of an adaptive mesh.
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Estudo topológico de escoamento trifásico óleo-água-ar através de sensor de impedância de resposta rápida do tipo \"wire-mesh\" / Topologic study of three-phase pipe flow by means of fast-response wire-mesh impedance sensorVelasco Peña, Hugo Fernando 27 February 2015 (has links)
A ocorrência frequente de escoamentos multifásicos em tubulações tem motivado um grande interesse acadêmico nas últimas décadas. O caso particular de escoamentos líquidolíquido é geralmente encontrado na indústria do petróleo, onde uma série de aplicações envolve escoamentos óleo-água, tais como a produção de petróleo e seu transporte. No entanto, ele não tem recebido a mesma atenção quando comparado com escoamentos gás-líquido. Ainda não existe uma explicação física razoável para um número significativo de fenômenos observados em escoamento óleo-água, como o fenômeno de redução de atrito, observado em escoamento disperso, e a estrutura interfacial ondulada em escoamento estratificado. Os escoamentos trifásicos têm sido ainda menos estudados. Há técnicas de medição, desenvolvidas para escoamento gás-líquido, que supostamente são adaptáveis aos escoamentos líquido-líquido, mas várias delas ainda precisam de validação adequada. O sensor wire-mesh, um método híbrido baseado na medição de resistência ou capacitância, que combina medição local intrusiva da fração de fase e imagens tomográficas transversais, oferece uma boa resolução espacial e alta resolução temporal em comparação com outras técnicas atuais. Porém, a literatura existente em aplicações do sensor wire-mesh cobre quase apenas o escoamento gás-líquido e, até agora, não é possível avaliar o limite de viscosidade do fluido para a sua aplicação. Neste contexto, este projeto propõe o estudo de aspectos importantes da fenomenologia de escoamentos líquido-líquido e líquido-líquido-gás com o auxílio da tecnologia wire-mesh. O principal objetivo prático é a validação da técnica wire-mesh como ferramenta de referência para o desenvolvimento de instrumentação para aplicações em campos petrolíferos, com especial atenção devotada ao efeito da viscosidade do óleo sobre a confiabilidade da medição e à extensão da tecnologia para lidar com escoamentos óleo-água-gás. / The frequent occurrence of multiphase flows in pipes has motivated a great research interest over the last decades. The particular case of liquid-liquid flow is commonly encountered in the petroleum industry, where a number of applications involve oil-water flow such as crude oil production and transportation. However, it has not received the same attention when compared to gas-liquid flow. There is no reasonable physical explanation for a significant number of phenomena observed in oil-water flow, as the drag reduction phenomenon observed in dispersed flow and the interfacial wavy structure of stratified flow. Much less has been investigated when it comes to three-phase flow. Several measurement techniques that are supposed to be adaptable to liquid-liquid flow have been proposed recently, but many of them still need proper validation. The wire-mesh sensor, a hybrid impedance-based method that combines intrusive local measurement of phase fraction and tomographic cross-sectional imaging, offers good spatial resolution and high temporal resolution in comparison with other current techniques. However, the existing literature on wire-mesh sensor applications covers almost only the gas-liquid flow and, so far, it is not possible to evaluate the fluid-viscosity limit for its application. In that context, this project proposes the study of important aspects of liquidliquid and liquid-liquid-gas flow phenomenology with the aid of the wire-mesh technology. The main goal is the validation of the wire-mesh technique as a reference tool for the development of instrumentation for oilfield application, with especial attention paid to the effect of oil viscosity on measurement reliability and the extension of the technology for dealing with oil-water-gas flow.
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Avaliação de impactos à saúde:desenvolvimento internacional e perspectivas no Brasil / Health Impact Assessment: international development and perspectives in BrazilBalby, Cecilia Negrão 21 August 2012 (has links)
Introdução: A Avaliação de Impactos à Saúde (AIS) é adotada em vários países como estratégia para abordar os potenciais impactos à saúde relacionados a políticas, planos, programas ou projetos, mas não é ainda utilizada no Brasil. Objetivo: Identificar as condições brasileiras que podem corroborar com vantagens e limitações da AIS já descritas na literatura internacional, considerando sua aplicação futura no Brasil, especialmente no caso de projetos. Métodos: Revisão da literatura científica e de outros documentos internacionais sobre AIS, identificados através de bases de dados (Pub Med e Science Direct), e de portais especializados, para entender o contexto e compilar vantagens e limitações da AIS. Revisão da literatura científica nacional e de outros documentos sobre avaliação de impactos e saúde, identificados através das bases de dados LILACS, SCIELO e outros portais brasileiros que tratam desses temas. Pesquisa qualitativa complementar com profissionais e pesquisadores brasileiros. Resultados e discussão: A AIS ainda está se desenvolvendo no mundo, por isso há vantagens e limitações igualmente importantes associadas aos seus indutores; ao objeto da avaliação (políticas, planos, programas ou projetos); à fase em que é conduzida (prospectiva ou retrospectiva); aos patrocinadores e avaliadores; ao tipo de AIS adotada; à sua institucionalização; à integração a outras formas de avaliação de impactos (AIA ou AAE); à abordagem em saúde, ao escopo e aos métodos adotados; à participação das partes afetadas e a sua influência no processo de tomada de decisão. No Brasil, os estudos que abordam os impactos à saúde são frequentemente retrospectivos e a abordagem de saúde na AIA apresenta lacunas. Os poucos estudos prospectivos ainda não utilizam as ferramentas e passos da AIS. O Ministério da Saúde vem articulando o processo de introdução da AIS no país. Conclusões e Recomendações: Há oportunidades para introduzir a AIS de projetos no país. Entretanto, é urgente o engajamento dos profissionais brasileiros da área de saúde e de avaliação de impactos com as redes de profissionais nacionais e internacionais, visando aprimorar a discussão e prepará-los para enfrentar questionamentos à AIS eventualmente levantados por aqueles que veem no processo de avaliação de impactos obstáculos para a eficiência e rapidez da tomada de decisão sobre projetos. É também preciso organizar padrões mínimos para que não sejam reproduzidos no Brasil problemas já vivenciados e solucionados em outras localidades / Introduction: Health Impact Assessment (HIA) is adopted as a strategy to address the potential health impacts associated with policies, plans, programs or projects in various countries, but not yet in Brazil. Objective: To identify the Brazilian conditions that can contribute to HIA advantages and constraints already described in the literature, considering its future adoption in Brazil, particularly in the case of projects. Method: Review of scientific literature and other documents on HIA, identified in Pub Med and Science Direct, as well as in HIA websites, in order to understand the context and compile HIA advantages and constraints already described in the literature. Review of Brazilian scientific literature and other Brazilian documents on impact assessment and health, identified through LILACS and SCIELO databases as well as other Brazilian web sites that address the subject. Additional qualitative research with Brazilian stakeholders. Results and discussion: HIA is still developing worldwide. Due to that, there are equally important advantages and limitations associated to its drivers, its object (policies, plans, programs or projects), when it is conducted (prospective or retrospective), HIA sponsors and assessors, HIA types, if HIA is institutionalized, if it is integrated with other forms of impact assessment (AIA, SEA), its approach to health, its scope and methods, the participation of affected parties and its influence to decision making. In Brazil, health impact assessments are frequently retrospective and do not adopt HIA tools and its steps. The Brazilian Ministry of Health is working to introduce HIA in the country. Conclusions and recommendations: There are opportunities to introduce HIA of projects in the country. However, it is urgent to engage Brazilian health and impact assessment professionals with national and international networks, in order to deepen and improve the discussion and to prepare them to face future questioning to HIA eventually raised by those that view the impact assessment process as an obstacle to efficiency in the context of project decision making. It is also necessary to develop minimum standards so that some issues already faced and solved elsewhere are not repeated in Brazil
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Hernienreparationen mit Netzprothesen klinische und experimentelle UntersuchungenZieren, Jürgen 16 March 2001 (has links)
In einer prospektiv-randomisierten klinischen Studie zur Leistenhernienreparation wurde die konventionelle Shouldice Operation mit den spannungsfreien Verfahren durch Netzimplantation in endoskopischer (transabdominelle praeperitoneale Netzplastik, TAPP) und offener Technik (Plug und Patch Reparation; PP) verglichen. Bezogen auf das Hauptzielkriterium postoperative Schmerzen ergaben beide spannungsfreie Verfahren (TAPP, PP) signifikant guenstigere Ergebnisse als die Shouldice Operation. Bei vergleichbarer Komplikationsrate war die Dauer postoperativer Einschraenkungen bei den spannungsfreien Verfahren ebenfalls signifikant kuerzer als nach Shouldice Operation. Zur Verbesserung der fuer die spannungsfreie Reparation erforderlichen Netzimplantate wurde in einer Tierstudie versucht, die bislang durch Resorption ungenuegende mechanische Stabilitaet eines resorbierbaren Polyglycolsaeure-Netzes durch Zugabe von Fibrinkleber bzw. humanen thrombozytaeren Wachstumsfaktoren zu verbessern. Hierdurch gelang ein signifikanter Anstieg der mechanischen Stabilitaet, so daß in dem verwendeten Tiermodell keine Herniationen auftraten. / In a prospective-randomized study conventional Shouldice operation was compared with tension-free procedures using mesh implantation in endoscopic (transabdominal preperitoneal mesh repair, TAPP) and open technique (Plug and patch repair; PP) for inguinal hernia repair. Regarding the mean end point postoperative pain both tension-free procedures (TAPP, PP) revealed significantly better results than Shouldice operation. Complications were comparable between the groups but duration of postoperative restrictions was significantly shorter after both tension-free procedures. To improve mesh quality for tension-free hernia repair an animal experiment was performed using a resorbable polyglycolic acid mesh. Despite good incorporation this mesh shows insufficient tensile strength due to absorption. Application of fibrin glue or platelet releasates significantly improve the mechanical stability of the repair protecting against herniation in this animal model.
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Avaliação de impactos à saúde:desenvolvimento internacional e perspectivas no Brasil / Health Impact Assessment: international development and perspectives in BrazilCecilia Negrão Balby 21 August 2012 (has links)
Introdução: A Avaliação de Impactos à Saúde (AIS) é adotada em vários países como estratégia para abordar os potenciais impactos à saúde relacionados a políticas, planos, programas ou projetos, mas não é ainda utilizada no Brasil. Objetivo: Identificar as condições brasileiras que podem corroborar com vantagens e limitações da AIS já descritas na literatura internacional, considerando sua aplicação futura no Brasil, especialmente no caso de projetos. Métodos: Revisão da literatura científica e de outros documentos internacionais sobre AIS, identificados através de bases de dados (Pub Med e Science Direct), e de portais especializados, para entender o contexto e compilar vantagens e limitações da AIS. Revisão da literatura científica nacional e de outros documentos sobre avaliação de impactos e saúde, identificados através das bases de dados LILACS, SCIELO e outros portais brasileiros que tratam desses temas. Pesquisa qualitativa complementar com profissionais e pesquisadores brasileiros. Resultados e discussão: A AIS ainda está se desenvolvendo no mundo, por isso há vantagens e limitações igualmente importantes associadas aos seus indutores; ao objeto da avaliação (políticas, planos, programas ou projetos); à fase em que é conduzida (prospectiva ou retrospectiva); aos patrocinadores e avaliadores; ao tipo de AIS adotada; à sua institucionalização; à integração a outras formas de avaliação de impactos (AIA ou AAE); à abordagem em saúde, ao escopo e aos métodos adotados; à participação das partes afetadas e a sua influência no processo de tomada de decisão. No Brasil, os estudos que abordam os impactos à saúde são frequentemente retrospectivos e a abordagem de saúde na AIA apresenta lacunas. Os poucos estudos prospectivos ainda não utilizam as ferramentas e passos da AIS. O Ministério da Saúde vem articulando o processo de introdução da AIS no país. Conclusões e Recomendações: Há oportunidades para introduzir a AIS de projetos no país. Entretanto, é urgente o engajamento dos profissionais brasileiros da área de saúde e de avaliação de impactos com as redes de profissionais nacionais e internacionais, visando aprimorar a discussão e prepará-los para enfrentar questionamentos à AIS eventualmente levantados por aqueles que veem no processo de avaliação de impactos obstáculos para a eficiência e rapidez da tomada de decisão sobre projetos. É também preciso organizar padrões mínimos para que não sejam reproduzidos no Brasil problemas já vivenciados e solucionados em outras localidades / Introduction: Health Impact Assessment (HIA) is adopted as a strategy to address the potential health impacts associated with policies, plans, programs or projects in various countries, but not yet in Brazil. Objective: To identify the Brazilian conditions that can contribute to HIA advantages and constraints already described in the literature, considering its future adoption in Brazil, particularly in the case of projects. Method: Review of scientific literature and other documents on HIA, identified in Pub Med and Science Direct, as well as in HIA websites, in order to understand the context and compile HIA advantages and constraints already described in the literature. Review of Brazilian scientific literature and other Brazilian documents on impact assessment and health, identified through LILACS and SCIELO databases as well as other Brazilian web sites that address the subject. Additional qualitative research with Brazilian stakeholders. Results and discussion: HIA is still developing worldwide. Due to that, there are equally important advantages and limitations associated to its drivers, its object (policies, plans, programs or projects), when it is conducted (prospective or retrospective), HIA sponsors and assessors, HIA types, if HIA is institutionalized, if it is integrated with other forms of impact assessment (AIA, SEA), its approach to health, its scope and methods, the participation of affected parties and its influence to decision making. In Brazil, health impact assessments are frequently retrospective and do not adopt HIA tools and its steps. The Brazilian Ministry of Health is working to introduce HIA in the country. Conclusions and recommendations: There are opportunities to introduce HIA of projects in the country. However, it is urgent to engage Brazilian health and impact assessment professionals with national and international networks, in order to deepen and improve the discussion and to prepare them to face future questioning to HIA eventually raised by those that view the impact assessment process as an obstacle to efficiency in the context of project decision making. It is also necessary to develop minimum standards so that some issues already faced and solved elsewhere are not repeated in Brazil
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