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O papel da omentectomia na cirurgia do câncer gástrico / The role of omentectomy in gastric cancer surgeryLeandro Cardoso Barchi 10 August 2018 (has links)
INTRODUÇÃO: Tradicionalmente, a omentectomia total (OT) é realizada juntamente com a ressecção gástrica associada à linfadenectomia na cirurgia do câncer gástrico (CG). No entanto, evidências sólidas em relação ao seu benefício oncológico são escassas. Este estudo foi elaborado para avaliar a incidência de metástases em linfonodos (LN) do grande omento em pacientes submetidos à gastrectomia potencialmente curativa por CG, assim como, avaliar os fatores de risco para a ocorrência de linfonodos metastáticos no grande omento e a evolução dos pacientes. PACIENTES E MÉTODOS: Foram avaliados 284 pacientes operados pelo Serviço de Cirurgia de Estômago, Duodeno e Intestino Delgado do HCFMUSP, no período de março de 2009 a abril de 2016, com diagnóstico de adenocarcinoma. Critérios de inclusão: pacientes submetidos a cirurgias potencialmente curativas com ressecção R0, com linfadenectomia a D2 ou D2 modificada conforme preconizado pela Escola Japonesa. Foram excluídos os pacientes que apresentaram doença disseminada ou metástases a distância, mesmo sendo submetidos a ressecções paliativas, assim como, pacientes com invasão macroscópica do grande omento, pacientes com neoplasias sincrônicas ou metacrônicas, neoplasia de coto gástrico, cirurgia com menos de 15 LN ressecados e ausência de tumor na análise anatomopatológica. O tempo de seguimento de todos os pacientes variou entre 1 e 89,5 meses, com mediana de 27,6 meses. O tempo de seguimento mediano dos pacientes livres de doença foi de 34,3 meses (mínimo de 1 e máximo de 89,5). A associação entre o acometimento de LN no omento com variáveis categóricas foram investigadas por testes exatos de Fisher ou teste qui-quadrado e com variáveis numéricas por testes de Wilcoxon-Mann-Whitney. Adotou-se nível de significância de 5%. RESULTADOS: A média de idade foi 61,8 anos (±11,9; entre 25 e 86). Dos 284 pacientes, cinco (1,8%) tinham LN metastáticos no grande omento (um: pT3N3bM0; dois: pT4aN3bM0; um: pT4aN2M0 e um pT4bN3bM0). Quatro deles faleceram e um estava sob tratamento paliativo com quimioterapia devido à recidiva da doença. Os LN metastáticos no grande omento tiveram correlação significativa com o tamanho do tumor, no qual se encontrou o ponto de corte de 5,25cm (área sob a curva ROC: 0,8072; IC95%: 0,6645 - 0,9498), estádio N (p < 0,001), estádio clínico (p=0,022), invasão venosa (p=0,003), recorrência (p=0,006), local de recorrência (peritôneo: p=0,008; fígado: p=0,023; ovário: p=0,035) e óbito (p=0,008). CONCLUSÃO: A incidência de LN metastático no grande omento de pacientes submetidos à gastrectomia radical por CG é baixa. A OT pode ser evitada em tumores menores que 5,25 cm e estádios T1/T2. Entretanto, a presença de metástases linfonodais no grande omento está associada a recidiva no peritônio, fígado, ovário e óbito / BACKGROUND: Traditionally, total omentectomy is performed along with gastric resection and extended lymphadenectomy in gastric cancer (GC) surgery. However, solid evidences regarding its oncologic benefit still lacks. The aim of this study was to evaluate the incidence of metastatic omental lymph nodes (LN) in patients undergoing potentially curative gastrectomy for GC, as well as its risk factors and patients\' outcomes. PATIENTS AND METHODS: In order to perform this analysis, 284 patients with adenocarcinoma operated at the Department of Surgery of Stomach, Duodenum and Small Intestine at HCFMUSP from March 2009 to April 2016 were reviewed. Inclusion criteria was: patients who underwent potentially curative R0 surgery with D2 lymphadenectomy as recommended by the Japanese School. Patients with disseminated disease or distant metastases, even if undergoing palliative resections were excluded from the study. As well as patients with macroscopic omental invasion, synchronic or metachronous neoplasms, gastric stump neoplasia, surgery with less than 15 harvested LN and absence of tumor in pathological analysis. The follow-up period of all patients ranged from 1 to 89.5 months, with a median of 27.6 months. The median follow-up period of disease-free patients was 34.3 months (minimum of 1 and maximum of 89.5 months). The association between omental LN involvement with categorical variables was investigated by Fisher\'s exact tests or chi-square test and numerical variables by Wilcoxon-Mann-Whitney tests. A significance level of 5% was adopted. RESULTS: The mean age was 61.8 years (± 11.9, range 25 - 86). Of 284 patients included, five (1.8%) patients had metastatic omental LN (one: pT3N3bM0; two: pT4aN3bM0; one: pT4aN2M0 and one pT4bN3bM0). Four of them deceased and one was under palliative chemotherapy due relapse. LN metastases in the greater omentum significantly correlated with tumor\'s size in which the cut-off found was 5.25cm (area under the ROC curve: 0.8072; IC95%: 0.6645 - 0.9498), N stage (p < 0.001), clinical stage (p=0.022), venous growth (p=0.003), recurrence (p=0.006), site of recurrence (peritoneum: p=0.008; liver: p=0.023; ovary: p=0.035) and death (p=0.008). CONCLUSION: The incidence of metastatic omental LN of patients undergoing radical gastrectomy due to GC is extremely low and may be avoided in tumors smaller than 5.25cm and T1/T2 tumors. Though, when present is associated with recurrence in peritoneum, liver, ovary and death
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DescriÃÃo de tÃcnica cirÃrgica para abordagem da cadeia mamÃria interna em esternos isolados de cadÃver / Description of surgical technique for boarding of the internal mammary chain in isolated esternos of corpsePaulla Vasconcelos Valente 08 January 2008 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / To identify the lymph node positioned along the internal mammary vessels in isolated sternum of human cadaver, to distinguish the number of lymph nodes at the second, third and forth intercostals spaces and to standardize the surgical approach to those nodes, in order to establish anatomical landmarks to be used with the current techniques of mammary gland sentinel lymph node detection. Ten sternum plates removed from unclaimed cadavers were used in this study. Sternal plates were removed using bilateral incisions of the ribs at the midclavicular lines. The characterization of the internal mammary vessels and the anatomical integrity of the parietal pleura were indispensable requirements during the procedure. The study was descriptive experimental. A total of 56 lymph nodes were removed from the second, third and forth intercostals spaces, being 30 at the right side and 26 ones at the left side. The second intercostal space was the one that shows the greatest number of lymph nodes in both sides. The lymph nodes of the chain of internal mammary vessels were dissected by a safe and practical technique, different from the one practiced by the Italian surgeons, pioneers at the dissection of the lymph nodes of the internal mammary vessels. The first stage of the dissection consisted of detaching the pectorals major muscle from its attachments to the manubrium and sternal body, exposing the sternocostal joints. Upon identification and detachment of the intercostals muscles approximately five cm from the ribs, special attention is paid to the neurovascular structures located at the superior border of the intercostal space, forming a window in a format of âUâ, exposing the internal mammary vessels and the lymph nodes to them related. The approach used is a reliable surgical technique for removing lymph node from sterna plates. The model is therefore valuable for breast surgeons training in sentinel node biopsy, an important procedure for breast cancer patients / Identificar os linfonodos localizados ao longo dos vasos mamÃrios internos em esternos isolados de cadÃveres, discriminar o nÃmero de linfonodos nos 2Â, 3Â e 4Â espaÃos intercostais e padronizar a abordagem cirÃrgica desses linfonodos, registrando os pontos de reparo a serem utilizados nas tÃcnicas atuais de pesquisa do linfonodo sentinela da mama. Estudaram-se dez esternos isolados de cadÃveres humanos. Os esternos foram obtidos atravÃs de secÃÃo bilateral do gradil costal ao nÃvel das linhas hemiclaviculares. A individualizaÃÃo e a integridade anatÃmica da pleura parietal e dos vasos mamÃrios internos foram requisitos imprescindÃveis durante a dissecÃÃo das peÃas. O estudo foi experimental descritivo. Um total de 56 linfonodos foram removidos dos 2Â, 3Â e 4Â espaÃos intercostais, sendo 30 Ã direita e 26 Ã esquerda. O 2Â espaÃo intercostal foi o que apresentou maior nÃmero de linfonodos nos lados direito e esquerdo. Os linfonodos da cadeia mamÃria interna foram abordados por uma tÃcnica segura, prÃtica e diferente da praticada pelos italianos, pioneiros na dissecÃÃo de linfonodos da cadeia mamÃria interna. Ocorre a divulsÃo do mÃsculo peitoral maior da sua inserÃÃo do manÃbrio e corpo do esterno, expondo as cartilagens esternocostais. Desinsere-se um segmento do mÃsculo intercostal de aproximadamente cinco cm a partir do bordo esternal de sua inserÃÃo no bordo superior da costela inferior do espaÃo intercostal, formando uma janela em âUâ, expondo assim os vasos mamÃrios internos e os linfonodos a eles relacionados. A abordagem cirÃrgica usada neste estudo demonstrou ser uma tÃcnica adequada para a exÃrese de linfonodos esternais. Conclui-se assim que o modelo utilizado se presta ao treinamento para o procedimento de biÃpsia de linfonodo sentinela, de grande valor na abordagem das pacientes portadoras de cÃncer de mama
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Caracterização dos padrões de drenagem linfática nas linfocintilografias de pacientes com câncer de mama / Characterization of the lymphatic drainage of patients with breast cancerFranciele Cristina Bernardes 26 January 2012 (has links)
O câncer de mama (CA de mama), com exceção do câncer de pele do tipo não melanoma, é o tumor de maior incidência dentre as mulheres, sendo que no Brasil são encontrados principalmente nas regiões Sul e Sudeste. Seu principal tratamento é o cirúrgico. A disseminação do tumor pode ocorrer por via linfática, acometendo linfonodos regionais. A biópsia do linfonodo sentinela (BLNS) é um procedimento altamente relevante, é altamente sensível na identificação de metástases. A técnica de linfocintilografia (LINCT) pré-operatória é essencial, pois permite avaliar a cadeia linfática acometida e possibilita a visualização do linfonodo sentinela (LNS) durante a cirurgia. O objetivo é descrever os padrões de drenagem linfática e avaliar a contribuição da LCINT na localização dos LNS em pacientes com CA de mama. No período de março de 2009 a agosto de 2011 foram estudados 70 casos sequenciais da rotina clínica, submetidos ao tratamento cirúrgico do CA de mama com estudo do LNS através da técnica de LCINT. Na LCINT foram aplicadas 4 injeções intradérmicas contendo 37 MBq (1,0 mCi) do FITATO-Tecnécio99m, ao redor da aréola mamária. Após a localização do LNS foi realizado marcações na pele, nas incidências anterior, oblíqua e lateral, para auxiliar o cirurgião na abordagem cirúrgica ulterior, juntamente com a sonda gama intra-operatória e corante azul patente. Dos 70 casos submetidos ao estudo, todos são do sexo feminino (100%) com faixa etária entre 28 e 77 anos, média de 54 anos. O tamanho médio do tumor encontrado nos pacientes foi de 1,4 cm. Os tipos histológicos mais incidentes foram o carcinoma ductal invasivo com 45 (64,4%) pacientes, seguido de carcinoma ductal in situ com 16 (22,8%). No exame de LCINT, todos os pacientes apresentaram drenagem linfática do radiofármaco a partir do local da injeção. Em 43 (61.5%) pacientes, observamos drenagem para 1 LNS, em 21 (30%) para 2 LNS/LNNS (linfonodo não sentinela), em 5 (7%) para 3 LNS/LNNS e em 1 (1.5%) para 4LNS/LNNS. Dos 70 pacientes, 68 (97%) apresentaram drenagem linfática ipsilateral e 2 (3%) apresentaram drenagem linfática bilateral. Em relação aos territórios de drenagem linfática dos LNS/LNNS, em 68 (97%) pacientes apresentaram drenagem para a região axilar, 1 (1,5%) para a região mamária interna e 1 (1,5%) para as regiões axilar e mamária interna. Os LNS/LNNS presentes na cadeia mamária interna não foram retirados. No intra-operatório, os cirurgiões utilizaram o corante azul patente em 35 (50%) pacientes, destes o corante identificou os LNS/LNNS em 79% dos casos. A técnica de LCINT possibilitou a visualização de todos os LNS e em alguns casos não foi possível a visualização do LNNS, o qual foi localizado e retirado com a sonda gama. Com isso, a técnica de LCINT foi eficaz em 88,5% dos casos. Dos 69 pacientes submetidos à BLNS apenas 13 (18,8%) pacientes apresentaram LNS/LNNS metastáticos, sendo estes submetidos à linfadenectomia axilar. Conclui-se que o exame pré-operatório de LCINT foi muito eficiente para o estudo da drenagem linfática, visualizando os canais linfáticos, linfonodos funcionalmente ativos e seus respectivos territórios de drenagem. Por tanto, esta técnica auxiliou o cirurgião na abordagem cirúrgica juntamente com a sonda gama intra-operatória e corante azul patente para a realização da BLNS. / With the exception of non-melanoma skin cancer, the Breast cancer (breast CA) is the most incident cancer in women. In Brazil, the breast CA is more often found in South and Southeast regions. The main treatment of breast CA is the surgery. The main pathway for the tumor spreading is the lymphatic system, which may affect the regional lymph nodes. The sentinel node biopsy (SLNB) is of considerable importance, once it has a high sensitivity in identifying metastases. The technique of preoperative lymphoscintigraphy (LINCT) is essential because it allows evaluating the lymphatic drainage chain and enables the visualization of sentinel lymph node (SLN) during surgery. We aim here to describe the lymphatic drainage patterns and to evaluate the contribution of LCINT to the location of SLN in patients with breast CA. We evaluated 70 patients sequentially selected from the clinical routine, between march 2009 and august 2011, and that underwent the surgical treatment for breast CA, including the usage of the technique of LCINT for the SLN location. The LCINT were performed by the injection of four periareolar intradermal injections containing 37 MBq (1.0 mCi) of the radiopharmaceutical PHYTATE-99m-Technetium. Based on the LCINT images, we performed skin marks in the dermal projections of the SLN in all anterior/posterior, oblique and lateral views. Additionally, the gamma probe and blue dye were used to help surgeons in the surgical location of the SLN. All of the 70 patients of our study were female, ranging from 28 to 77 years, mean 54 years. The average tumor size was 1.4 cm. The most commonly found histological types were invasive ductal carcinoma (45 patients, 64.4%), followed by the in situ ductal carcinoma (16 patients, 22.8%). All LCINT procedures were well succeeded in demonstrating at least one SLN in our sample of patients. We observed lymphatic drainage for only one SLN in 43 patients (61.5%), for 2 SLN/SLNN in 21 (30%) (non sentinel lymph node), for 3 SLN/SLNN in 5 (7%) and for 4 SLN/SLNN in one patient (1.5%). From the 70 patients, 68 (97%) exhibited ipsilateral and 2 (3%) exhibited bilateral lymphatic drainage. Concerning the lymphatic territories, 68 patients (97%) exhibited drainage to SLN/SLNN in the axillary region, 1 patient (1.5%) in the internal mammary region and another patient (1.5%) in both axillary and internal mammary regions. The two SLN/SLNN found in the internal mammary chain were not removed. Complimentary to the LCINT, the surgeons used blue dye in 35 patients (50%), which enabled them to identify the SLN/SLNN in 79% of cases. On the other hand, LCINT allowed the visualization of all SLN (100%). In some cases, in which was not possible to visualize the SLNN, these ones were found by the use of the gamma probe. Thus, the LCINT technique was effective to localize the SLN in 88.5% of cases. From the 69 patients who underwent SLN biopsy, only 13 patients (18.8%) exhibited metastatic infiltration of the SLN/ SLNN. All these patients were submitted to the axillary dissection. We conclude that the preoperative LCINT was very effective for the study of lymphatic drainage, enabling the visualization of the lymphatic channels, functionally active nodes and their drainage areas. Therefore, this technique helped surgeons in the surgical approach with intraoperative gamma probe and patent blue dye for SLNB.
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Linfonodectomia retroperitoneal e pélvica lateral guiada por radiotraçador e azul patente no estadiamento do adenocarcinoma do reto / Retroperitoneal and lateral pelvic lymphadenectomy mapped by lymphoscintigraphy and blue dye for rectal adenocarcinoma stagingClaudio de Almeida Quadros 18 September 2009 (has links)
INTRODUÇÃO: A excisão total do mesorreto é o procedimento cirúrgico padrão para o tratamento do adenocarcinoma do reto. Resultados satisfatórios, em termos de prognóstico, alcançados com a associação da linfonodectomia retroperitoneal e pélvica lateral questionam se somente a excisão total do mesorreto seria suficiente para um estadiamento adequado, podendo afetar decisões relacionadas ao tratamento adjuvante. Este estudo avaliou o impacto das metástases em linfonodos retroperitoneais e/ou pélvicos laterais na mudança do estadiamento de pacientes com adenocarcinoma do reto e a acurácia da identificação de metástases em linfonodos das cadeias retroperitoneais e/ou pélvicas laterais com o uso de tecnécio-99m-fitato e/ou azul patente. MÉTODOS: Foi realizado estudo prospectivo de janeiro de 2004 a agosto de 2008, composto por 97 pacientes com adenocarcinoma do reto extraperitoneal submetidos a tratamento cirúrgico curativo com excisão total do mesorreto e linfonodectomia retroperitoneal e pélvica lateral, com pesquisa de linfonodos das cadeias retroperitoneais e pélvicas laterais identificados com tecnécio-99m-fitato e/ou corados em azul patente. Os linfonodos radioativos e/ou azuis, quando negativos ao exame histopatológico com hematoxilina-eosina, foram submetidos à multisecções histológicas com uso de técnicas imunohistoquímicas com anticorpos anticitoqueratinas (AE1/AE3). RESULTADOS: A média de linfonodos nas peças de excisão total do mesorreto foi de 11,5 (1119/97) e nas cadeias retroperitoneais e pélvicas laterais foi de 11,7 (1136/97). A linfonodectomia retroperitoneal e pélvica lateral identificou metástases em 17,5% dos pacientes do estudo e promoveu aumento do estádio TNM II para III em 8,2% dos pacientes. As variáveis relacionadas à presença de linfonodos retroperitoneais e/ou pélvicos laterais metastáticos foram o estádio III estabelecido na peça cirúrgica da excisão total do mesorreto (P < 0,04); a classificação pT3/pT4 do tumor primário (P = 0,047); níveis elevados de antígeno carcinoembrionário, com média de 30,6 ng/ml e mediana de 9,9 ng/ml (P = 0,014); e grandes tumores, com tamanho médio de 5,5 ± 3,2 cm (P = 0,03). A migração do tecnécio e/ou azul patente para linfonodos retroperitoneais e/ou pélvicos laterais ocorreu em 37,1% (36/97), modificando o estadiamento em 11,1% dos pacientes estudados. A acurácia do uso do tecnécio e/ou azul patente na detecção de metástases nos linfonodos retroperitoneais e pélvicos laterais foi de 100%, com sensibilidade de 100%, valor preditivo negativo de 100% e zero de falso-negativos. CONCLUSÕES: Deve-se aprimorar o uso de marcadores na identificação de metástases para indicação seletiva da linfonodectomia retroperitoneal e pélvica lateral em adenocarcinoma retal. / BACKGROUND: Total mesorectal excision is the standard surgical procedure for rectal adenocarcinoma treatment. Good prognostic results achieved with retroperitoneal and lateral pelvic lymphadenectomy have questioned that total mesorectal excision might not be satisfactory for adequate patient staging, affecting adjuvant therapeutic definitions. The aims of this study were to define the upstaging impact of metastasis to retroperitoneal and/or lateral pelvic nodes in patients with rectal adenocarcinoma and the accuracy of dye and/or probe search in the detection of metastatic retroperitoneal and/or lateral pelvic nodes. METHODS: A prospective study was carried on from January of 2004 to August of 2008, composed of 97 extraperitoneal rectal adenocarcinoma patients submitted to curative intent surgeries with total mesorectal excision and retroperitoneal and lateral pelvic lymphadenectomy, with retroperitoneal and lateral pelvic nodes mapping using technetium-99m-phytate and/or patent blue. The radioactive and/or blue nodes, when negative to histopathological hematoxylin-eosin staining, were submitted to step-sectioning and immunohistochemical examination with antibody against cytokeratin (AE1/AE3). RESULTS: Mean node count of the mesorectal excision specimen was 11.5 (1119/97) and of the retroperitoneal and lateral pelvic lymphadenectomy was 11.7 (1136/97). Retroperitoneal and lateral pelvic lymphadenectomy identified metastasis in 17.5% of the studied patients and modified TNM stage II to III in 8.2% of the patients. Factors related to metastatic retroperitoneal and lateral pelvic nodes were stage III defined by examination of the surgical specimen of the total mesorectal excision (P < 0,004); tumor pT3/pT4 classification (P = 0,047); high levels of carcinoembryonic antigen, with average of 30.6 ng/ml and median of 9.9 ng/ml (P = 0,014); and large tumors, with mean size of 5.5 cm ± 3,2 cm (P = 0,03). Technetium and/or patent blue migration to retroperitoneal and/or lateral pelvic nodes occurred in 37.1% (36/97), upstaging 11.1% of the studied patients. Technetium and/or patent blue accuracy in the detection of metastasis to retroperitoneal and/or lateral pelvic nodes was of 100%, with sensibility of 100%, negative predictive value of 100% and zero false negatives. CONCLUSIONS: The use of markers should be improved in the identification of metastasis for selective indication of retroperitoneal and lateral pelvic lymphadenectomy.
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Authentication in peer-to-peer systems / Autenticering i peer-to-peer systemÅslund, Jonas January 2002 (has links)
In the environment of the 3:rd generation Internet based on peer-to-peer architecture, well-trusted methods must exist to establish a secure environment. One main issue is the possibility to verify that a node actually is who it claims to be (authentication). Establishment of authentication between nodes in a peer-to-peer environment where nodes are exchanging information directly with each other requires more planning than in a typical client-server environment where the authentication methods are server-based. The peer-to-peer applications described in this report use authentication methods based on central authorities as well as solutions without central authorities. Lack of standards in the way peer-to-peer systems should communicate and apply security lead to a variety of “local” communication and security solutions. These local solutions make different applications incompatible with each other, meaning that a peer using one application will not be able to communicate and exchange information with other peers using some other application.
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Energy Efficient Wireless Sensor Node Architecture for Data and Computation Intensive ApplicationsShahzad, Khurram January 2014 (has links)
Wireless Sensor Networks (WSNs), in addition to enabling monitoring solutions for numerous new applications areas, have gained huge popularity as a cost-effective, dynamically scalable, easy to deploy and maintainable alternatives to conventional infrastructure-based monitoring solutions. A WSN consists of spatially distributed autonomous wireless sensor nodes that measure desired physical phenomena and operate in a collaborative manner to relay the acquired information wirelessly to a central location. A wireless sensor node, integrating the required resources to enable infrastructure-less distributed monitoring, is constrained by its size, cost and energy. In order to address these constraints, a typical wireless sensor node is designed based on low-power and low-cost modules that in turn provide limited communication and processing performances. Data and computation intensive wireless monitoring applications, on the other hand, not only demand higher communication bandwidth and computational performance but also require practically feasible operational lifetimes so as to reduce the maintenance cost associated with the replacement of batteries. In relation to the communication and processing requirements of such applications and the constraints associated with a typical wireless sensor node, this thesis explores energy efficient wireless sensor node architecture that enables realization of data and computation intensive applications. Architectures enabling raw data transmission and in-sensor processing with various technological alternatives are explored. The potential architectural alternatives are evaluated both analytically and quantitatively with regards to different design parameters, in particular, the performance and the energy consumption. For quantitative evaluation purposes, the experiments are conducted on vibration and image-based industrial condition monitoring applications that are not only data and computation intensive but also are of practical importance. Regarding the choice of an appropriate wireless technology in an architecture enabling raw data transmission, standard based communication technologies including infrared, mobile broadband, WiMax, LAN, Bluetooth, and ZigBee are investigated. With regards to in-sensor processing, different architectures comprising of sequential processors and FPGAs are realized to evaluate different design parameters, especially the performance and energy efficiency. Afterwards, the architectures enabling raw data transmission only and those involving in-sensor processing are evaluated so as to find an energy efficient solution. The results of this investigation show that in-sensor processing architecture, comprising of an FPGA for computation purposes, is more energy efficient when compared with other alternatives in relation to the data and computation intensive applications. Based on the results obtained and the experiences learned in the architectural evaluation study, an FPGA-based high-performance wireless sensor platform, the SENTIOF, is designed and developed. In addition to performance, the SETNIOF is designed to enable dynamic optimization of energy consumption. This includes enabling integrated modules to be completely switched-off and providing a fast configuration support to the FPGA. In order to validate the results of the evaluation studies, and to assess the performance and energy consumption of real implementations, both the vibration and image-based industrial monitoring applications are realized using the SENTIOF. In terms of computational performance for both of these applications, the real-time processing goals are achieved. For example, in the case of vibration-based monitoring, real-time processing performance for tri-axes (horizontal, vertical and axial) vibration data are achieved for sampling rates of more than 100 kHz. With regards to energy consumption, based on the measured power consumption that also includes the power consumed during the FPGA’s configuration process, the operational lifetimes are estimated using a single cell battery (similar to an AA battery in terms of shape and size) with a typical capacity of 2600 mA. In the case of vibration-based condition monitoring, an operational lifetime of more than two years can be achieved for duty-cycle interval of 10 minutes or more. The achievable operational lifetime of image-based monitoring is more than 3 years for a duty-cycle interval of 5 minutes or more.
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Reliability in wireless sensor networks / Fiabilisation des transmissions dans les réseaux de capteurs sans filsMaalel, Nourhene 30 June 2014 (has links)
Vu les perspectives qu'ils offrent, les réseaux de capteur sans fil (RCSF) ont perçu un grand engouement de la part de la communauté de recherche ces dernières années. Les RCSF couvrent une large gamme d'applications variant du contrôle d'environnement, le pistage de cible aux applications de santé. Les RCSFs sont souvent déployés aléatoirement. Ce dispersement des capteurs nécessite que les protocoles de transmission utilisés soient résistants aux conditions environnementales (fortes chaleurs ou pluies par exemple) et aux limitations de ressources des nœuds capteurs. En effet, la perte de plusieurs nœuds capteurs peut engendrer la perte de communication entre les différentes entités. Ces limitations peuvent causer la perte des paquets transmis ce qui entrave l'activité du réseau. Par conséquent, il est important d'assurer la fiabilité des transmissions de données dans les RCSF d'autant plus pour les applications critiques comme la détection d'incendies. Dans cette thèse, nous proposons une solution complète de transmission de données dans les RCSF répondant aux exigences et contraintes de ce type de réseau. Dans un premier temps, nous étudions les contraintes et les challenges liés à la fiabilisation des transmissions dans les RCSFs et nous examinons les travaux proposés dans la littérature. Suite à cette étude nous proposons COMN2, une approche distribuée et scalable permettant de faire face à la défaillance des nœuds. Ensuite, nous proposons un mécanisme de contrôle d'erreur minimisant la perte de paquets et proposant un routage adaptatif en fonction de la qualité du lien. Cette solution est basée sur des acquittements implicites (overhearing) pour la détection des pertes des paquets. Nous proposons ensuite ARRP une variante de AJIA combinant les avantages des retransmissions, de la collaboration des nœuds et des FEC. Enfin, nous simulons ces différentes solutions et vérifions leurs performances par rapport à leurs concurrents de l'état de l'art. / Over the past decades, we have witnessed a proliferation of potential application domainsfor wireless sensor networks (WSN). A comprehensive number of new services such asenvironment monitoring, target tracking, military surveillance and healthcare applicationshave arisen. These networked sensors are usually deployed randomly and left unattendedto perform their mission properly and efficiently. Meanwhile, sensors have to operate ina constrained environment with functional and operational challenges mainly related toresource limitations (energy supply, scarce computational abilities...) and to the noisyreal world of deployment. This harsh environment can cause packet loss or node failurewhich hamper the network activity. Thus, continuous delivery of data requires reliabledata transmission and adaptability to the dynamic environment. Ensuring network reliabilityis consequently a key concern in WSNs and it is even more important in emergencyapplication such disaster management application where reliable data delivery is the keysuccess factor. The main objective of this thesis is to design a reliable end to end solution for data transmission fulfilling the requirements of the constrained WSNs. We tackle two design issues namely recovery from node failure and packet losses and propose solutions to enhance the network reliability. We start by studying WSNs features with a focus on technical challenges and techniques of reliability in order to identify the open issues. Based on this study, we propose a scalable and distributed approach for network recovery from nodefailures in WSNs called CoMN2. Then, we present a lightweight mechanism for packetloss recovery and route quality awareness in WSNs called AJIA. This protocol exploitsthe overhearing feature characterizing the wireless channels as an implicit acknowledgment(ACK) mechanism. In addition, the protocol allows for an adaptive selection of therouting path by achieving required retransmissions on the most reliable link. We provethat AJIA outperforms its competitor AODV in term of delivery ratio in different channelconditions. Thereafter, we present ARRP, a variant of AJIA, combining the strengthsof retransmissions, node collaboration and Forward Error Correction (FEC) in order toprovide a reliable packet loss recovery scheme. We verify the efficiency of ARRP throughextensive simulations which proved its high reliability in comparison to its competitor.
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基於臉書互動行為的關係圖領域專屬語言與工具 / A Domain Specific Language for Describing Facebook Interaction Graphs潘宗佐, Pan, Tsung Tso Unknown Date (has links)
因大量臉書用戶留下不少行為紀錄,吸引研究人員蒐集臉書資料,從中挖掘具有價值的潛在資訊與研究成果,並用 Graph 點線關係圖視覺化呈現成果。然而透過臉書 Graph API 蒐集資料的方法,自 2.0 版起漸漸提高了限速限制,造成蒐集資料開始是一個問題。雖有研者人員提出應對方法,卻也產生用戶識別度弱化問題。故本研究動機是提出一套工具能有效協助研究人員進行臉書資料蒐集與建立關係圖以利進行分析與研究,在進行相關臉書蒐集資料與社會網絡與社群網絡分析文獻探討後,實作一種基於爬蟲技術,蒐集具用戶識別度之臉書資料;以及提出描述臉書互動行為的關係圖領域專屬語言;實作對應之使用者操作介面工具,讓使用者透過圖形化操作方式描述定義臉書粉絲頁、使用者、Hashtag、留言及回覆與貼文之間互動行為建立關係圖。經過本研究實驗設計與驗證,證明蒐集資料具識別度、產生的關係圖是正確以及問卷調查指出 75% 受試人員認同本系統可快速建立關係圖。未來可以結合爬蟲與關係圖領域專屬語言線上即時建立關係圖,以及導入更多社群分析功能,以利研究人員可以在本系統上進行更深入的分析與研究。 / The huge amount of digital footprints of Facebook users have become a good
research resource and we have seen many good results developed by collecting
data from Facebook and visualizing it to node-link diagram. However, there are
more and more rate limits in Facebook Graph API since version 2.0. Although
one could overcome the restriction of rate limits by creating more Facebook
App resources, yet this makes user identification become cumbersome in
analyzing the retrieved data. Therefore, the motivation of this research is to
provide a set of tools to assist researchers in collecting recognizable Facebook
user data with a crawler and propose a domain specific language (DSL) to build
the relation graph by describing Facebook interactions. With our crawler and
the DSL tool, we are able to gather unique user data successfully. The
experimental results show that we can construct node-link diagram conveniently,
and 75% of the surveyed subjects agreed that our tool could be helpful for building graph.
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Loftus metrorail station : from barrier to catalystKotze, Michelle 25 November 2008 (has links)
South Africa is more than ever, in need of a public transport system integrated within its surroundings. A successful transportation network needs an environment where users can change transport systems with ease and peace of mind. The ultimate goal is to achieve a pedestrian orientated city. This dissertation will attempt to address these problems by redesigning Loftus Metrorail Station located in Hatfield, Pretoria, South Africa. Within the transport node, Loftus station, the challenge is to combine the different movement systems intersecting at this point, reinforcing connectivity and accessibility. The transition from public to private needs to be clear and legible - this can be achieved through the appropriate design of the building interface, and clearly defining spatial boundaries. The sense of place is lacking in this area, already containing various landmarks associated with Hatfield. These landmarks assist with the legibility of the project area. This orientation device assists with ease of movement and circulation within the area. The defragmentation of facilities in the Loftus precinct area is due to the large scale of the city block. Loftus station becomes a barrier between the University of Pretoria and Loftus Versfeld Stadium. It is an isolated site – dislocated from its surroundings. The lack of facilities has lead to the station becoming underutilized and dilapidated. By dividing the study area into human scaled city blocks, the area becomes manageable. This division reinforces already existing pedestrian movement patterns. The activation of edges and transparency of the structure ensures a secure environment. The different movement systems at this node influenced the design and choice of materials used in the project. The user requirements had to be satisfied. The careful integration of commerce within the station and surroundings ensure not only a transition space, but also a controlled and activated destination place. / Dissertation (MArch(Prof))--University of Pretoria, 2009. / Architecture / unrestricted
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Genius Loci : a cultural centre for the visual and performing artsSparks, Christopher Duane 09 December 2009 (has links)
The aim of this dissertation is to explore the possibilities of architecture as a sensory phenomenon and to explore how we can experience architectural space through all our senses, and how architecture can influence how we experience our senses in space. The project is located within the cultural node identified within the Nelson Mandela Development Corridor (MDC) and the proposed building is one of a cultural centre for the visual and performing arts. The centre is aimed at creating a heightened awareness and insight into the creative processes of artists and performers for the general public, community, users and occupants of the centre and passers-by. This will be achieved through the creation of visual connections and physical interactions between the users, artists and performers and passers by as well has creating a heightened experience of space and place on a human scale for visitors, performers, artists and general public. The centre also incorporates retail, commercial and residential components in order to energise the square and centre throughout the day and night, creating an active 24hour environment, which is often lacking in a development of this nature. The activities of the centre, along with those of the existing Oeverzicht houses and old M.O.T.H. club, that have been incorporated into the development spill out onto a central urban activity square, where impromptu and planned performances are to be staged. The aim of the development is ultimately to develop a synthesis between arts, culture, economy and urban vitality by creating a platform for the arts. The aim of this dissertation is to explore the ability of spaces inside this building typology to assist in inspiring each of its occupants through the creation of memorable spatial experiences. / Dissertation (MArch(Prof))--University of Pretoria, 2010. / Architecture / unrestricted
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