86 research outputs found

    Enabling Internet-Scale Publish/Subscribe In Overlay Networks

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    As the amount of data in todays Internet is growing larger, users are exposed to too much information, which becomes increasingly more difficult to comprehend. Publish/subscribe systems leverage this problem by providing loosely-coupled communications between producers and consumers of data in a network. Data consumers, i.e., subscribers, are provided with a subscription mechanism, to express their interests in a subset of data, in order to be notified only when some data that matches their subscription is generated by the producers, i.e., publishers. Most publish/subscribe systems today, are based on the client/server architectural model. However, to provide the publish/subscribe service in large scale, companies either have to invest huge amount of money for over-provisioning the resources, or are prone to frequent service failures. Peer-to-peer overlay networks are attractive alternative solutions for building Internet-scale publish/subscribe systems. However, scalability comes with a cost: a published message often needs to traverse a large number of uninterested (unsubscribed) nodes before reaching all its subscribers. We refer to this undesirable traffic, as relay overhead. Without careful considerations, the relay overhead might sharply increase resource consumption for the relay nodes (in terms of bandwidth transmission cost, CPU, etc) and could ultimately lead to rapid deterioration of the system’s performance once the relay nodes start dropping the messages or choose to permanently abandon the system. To mitigate this problem, some solutions use unbounded number of connections per node, while some other limit the expressiveness of the subscription scheme. In this thesis work, we introduce two systems called Vitis and Vinifera, for topic-based and content-based publish/subscribe models, respectively. Both these systems are gossip-based and significantly decrease the relay overhead. We utilize novel techniques to cluster together nodes that exhibit similar subscriptions. In the topic-based model, distinct clusters for each topic are constructed, while clusters in the content-based model are fuzzy and do not have explicit boundaries. We augment these clustered overlays by links that facilitate routing in the network. We construct a hybrid system by injecting structure into an otherwise unstructured network. The resulting structures resemble navigable small-world networks, which spans along clusters of nodes that have similar subscriptions. The properties of such overlays make them an ideal platform for efficient data dissemination in large-scale systems. The systems requires only a bounded node degree and as we show, through simulations, they scale well with the number of nodes and subscriptions and remain efficient under highly complex subscription patterns, high publication rates, and even in the presence of failures in the network. We also compare both systems against some state-of-the-art publish/subscribe systems. Our measurements show that both Vitis and Vinifera significantly outperform their counterparts on various subscription and churn scenarios, under both synthetic workloads and real-world traces

    Vitis: A Gossip-based Hybrid Overlay for Internet-scale Publish/Subscribe

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    Peer-to-peer overlay networks are attractive solutions for building Internet-scale publish/subscribe systems. However, scalability comes with a cost: a message published on a certain topic often needs to traverse a large number of uninterested (unsubscribed) nodes before reaching all its subscribers. This might sharply increase resource consumption for such relay nodes (in terms of bandwidth transmission cost, CPU, etc) and could ultimately lead to rapid deterioration of the system’s performance once the relay nodes start dropping the messages or choose to permanently abandon the system. In this paper, we introduce Vitis, a gossip-based publish/subscribe system that significantly decreases the number of relay messages, and scales to an unbounded number of nodes and topics. This is achieved by the novel approach of enabling rendezvous routing on unstructured overlays. We construct a hybrid system by injecting structure into an otherwise unstructured network. The resulting structure resembles a navigable small-world network, which spans along clusters of nodes that have similar subscriptions. The properties of such an overlay make it an ideal platform for efficient data dissemination in large-scale systems. We perform extensive simulations and evaluate Vitis by comparing its performance against two base-line publish/subscribe systems: one that is oblivious to node subscriptions, and another that exploits the subscription similarities. Our measurements show that Vitis significantly outperforms the base-line solutions on various subscription and churn scenarios, from both synthetic models and real-world traces

    Correlation between expression levels of mRNA IL-6 and H. pylori-infected patients with cagA

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    BACKGROUND AND OBJECTIVE: Helicobacter pylori (H. pylori) infection is associated with marked infiltration inflammatory cells such as neutrophil, macrophage and H. pylori-specific T and B cell in the gastric mucosa. The molecular pathways that control H. pylori-associated inflammatory reaction are complex, but locally induced cytokines seem to contribute to maintaining the ongoing inflammation. The purpose of this study was to evaluate IL-6 gene expression in the H. pylori-infected and uninfected gastric patients and correlation it’s with cagA among H. pylori infected patients. METHODS: This study is case - control. Biopsies were collected from 58 H. pylori-infected patients and 44 uninfected. Mucosal IL-6 mRNA levels were measured by real-time PCR. Presence of cagA virulence factor was evaluated using PCR. Cytokine expression is presented as means and differences between infected and non-infected groups were analysed using the T-Test test. FINDINGS: The IL-6 mRNA expression levels were signiïŹcantly more elevated in H. pylori-positive patients than uninfected. There was no association between cagA virulence factor in H. pylori-infected patients and IL-6 mRNA expression. Conclusion: The enhanced induction of IL-6 may be independent cagA virulence factor involved in the pathogenesis of H. pylori-associated gastritis

    Semi-Supervised Multiple Disambiguation

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    Determining the true entity behind an ambiguousword is an NP-Hard problem known as Disambiguation. Previoussolutions often disambiguate a single ambiguous mention acrossmultiple documents. They assume each document contains onlya single ambiguous word and a rich set of unambiguous contextwords. However, nowadays we require fast disambiguation ofshort texts (like news feeds, reviews or Tweets) with few contextwords and multiple ambiguous words. In this research we focuson Multiple Disambiguation (MD) in contrast to Single Disambiguation(SD). Our solution is inspired by a recent algorithm developed for SD. The algorithm categorizes documents by first,transferring them into a graph and then, clustering the graphbased on its topological structure. We changed the graph-baseddocument-modeling of the algorithm, to account for MD. Also,we added a new parameter that controls the resolution of theclustering. Then, we used a supervised sampling approach formerging the clusters when appropriate. Our algorithm, comparedwith the original model, achieved 10% higher quality in termsof F1-Score using only 4% sampling from the dataset.QC 20160407</p

    Determination of Optimal Structure of Capital Using Particles’ Mass Optimization Combination Algorithm

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    The aim of this study was to determine optimal structure of the listed companies on Tehran Stock Exchange using particles’ mass optimization algorithm. Its population included all companies listed on Tehran Stock Exchange from 2004 to 2012 (n= 157). There were selected 100 companies as sample. Particles’ mass combination algorithm was used to analyze data. The results showed that the obtained optimal debt by particles’ mass algorithm is more than or equal to the obtained corresponding values ​​by genetic algorithm in all companies and different industries. Since there is a significant negative relationship between capital structure and rate of return on assets (profitability), lower debt ratio means more profitability. The results indicate that particles mass algorithm has more capable than genetic algorithm to achieve high-quality results. In other words, particles mass algorithm is stronger and more successful than GA to determine optimal capital structure in all companies and different industries

    Effectiveness of Short-Term Cognitive-Behavioral Group Therapy on Binge Eating Disorder in Females

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    Purpose: Due to an increasing prevalence of over eating disorders, this paper aims to investigate the effectiveness of short-term group cognitive-behavioral therapy on reducing binge eating behavior and depression symptoms among females suffered from binge eating disorder (BED) in Qazvin, Iran. Methodology: This is aquasi-experimental study (pre-post testing plan with control group). Using a convenience sampling technique, binge eating scale (BES) and clinical interviews, 30 persons were selected among all clients who had referred to weight loss centers in Qazvin, these persons were randomly placed into two control and experimental groups. The experimental group participated in a seven-session plan on short-term cognitive-behavioral group therapy. Results: The results showed that the short term group cognitive-behavioral therapy results in a significant reduction in binge eating signs and depressive symptoms within the experimental group, compared to the control. Conclusion: Regarding the results, it is known that short-term group cognitive-behavioral therapy is effective in reducing overeating symptoms. Hence, it can be used as an economical and effective treatment method for individuals suffering from BED

    Effectiveness of Short-Term Cognitive-Behavioral Group Therapy on Binge Eating Disorder in Females

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    Purpose: Due to an increasing prevalence of over eating disorders, this paper aims to investigate the effectiveness of short-term group cognitive-behavioral therapy on reducing binge eating behavior and depression symptoms among females suffered from binge eating disorder (BED) in Qazvin, Iran. Methodology: This is aquasi-experimental study (pre-post testing plan with control group). Using a convenience sampling technique, binge eating scale (BES) and clinical interviews, 30 persons were selected among all clients who had referred to weight loss centers in Qazvin, these persons were randomly placed into two control and experimental groups. The experimental group participated in a seven-session plan on short-term cognitive-behavioral group therapy. Results: The results showed that the short term group cognitive-behavioral therapy results in a significant reduction in binge eating signs and depressive symptoms within the experimental group, compared to the control. Conclusion: Regarding the results, it is known that short-term group cognitive-behavioral therapy is effective in reducing overeating symptoms. Hence, it can be used as an economical and effective treatment method for individuals suffering from BED

    A Distributed Algorithm For Large-Scale Graph Partitioning

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    Detta kandidatarbete har sin placering pĂ„ Skeppsbron/Skeppsbrokajen i centrala Stockholm. Inriktningen jag valde var att rita ett förslag för en fiskmarknad som skulle placeras pĂ„ denna plats. Mitt arbete har fĂ„tt inspireras av Sveriges största och mest kĂ€nda fiskmarknad, Feskekörkan, i Göteborg. Analyser av Feskekörkan som organisation och dess planlösning har i mitt arbete lett till en tektoniskt uppbyggd struktur dĂ€r material byggnadskonstruktion var viktiga element. Med bland annat en fiskfjĂ€llsfasad i mĂ€ssing och en bĂ€rande skelett av storskaliga limtrĂ€balkar. Platsen som byggnaden ligger pĂ„ Ă€r ett vĂ€lbesökt promenadstrĂ„k med en bred och lĂ„ng kajkant som anvĂ€nds flitigt av sĂ„vĂ€l, turister som besöker gamla stan och det kungliga slottet, och Stockholmare som tar sig mellan Södermalm och Norrmalm. Jag har valt att bebygga platsen pĂ„ ett sĂ€tt som bĂ„de tar vara pĂ„ det vackra promenadstrĂ„ket men ocksĂ„ ger möjlighet för besökande att stanna upp och ta del av fiskmarknaden.This candidate's work has its placement on Skeppsbron/Skeppsbrokajen in the central area of Stockholm. The focus I chose was to draw a proposal for a fishmarket that would be placed at this location. My work has been inspired by the largest and most famous fish market in Sweden, Feskekörkan, in Gothenburg. Analyses of Feskekörkan’s organization and its plan has, in my work, led to a tectonically constructed structure where building materials were important elements. Including a fish scale facade made of brass and a bearing skeleton of large glulam beams. The place which the building is situated on a popular promenade with a broad and long quay which is widely used by both, tourists visiting the Old Town and the Royal Palace, and the Stockholm citizens who ride between Södermalm and Norrmalm. I have chosen to build on the site in a way that both takes advantage of the beautiful promenade but also provides the opportunity for visitors to stop and take some of the fish market

    Comparative evaluation between diameter difference of thumb and asymmetry of lateral cerebral ventricles in child with developmental delay; a new finding

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    How to Cite This Article: Keihanidoust Z, Shariat M, Rahimian E, Tehrani F, Saddighi Gh. Comparative Evaluation between Diameter Difference of the Thumb and Asymmetry of Lateral Cerebral Ventricles in Children with Developmental Delay: A  New Finding. Iran J Child Neurol. Summer 2015;9(3):9-12.Abstract Objective Anthropometry (measurement of body dimensions) has been used for clinical diagnosis of growth and developmental disorders during pregnancy and after birth. Different brain volumes have also been shown in abnormal developmental disorders. This study compares the different horizontal diameters of the left- and right-hand thumbnails and asymmetry of lateral cerebral ventricles in children with developmental delays. Materials &amp; Methods This retrospective case control study was carried out in the Pediatric Neurologic Outpatient of a university hospital in Tehran, Iran (2009–2011). Twenty-eight patients with motor developmental disorders (case) and 28 healthy individuals (control) had brain MRIs and volume of lateral cerebral ventricles size had been studied. The maximum horizontal diameters of the left and right thumbnails were measured by calipers during physical and neurological exams by a pediatric neurologist. Finally, we compared and analyzed different horizontal diameters of the left and right hand thumbnails and asymmetry of lateral cerebral ventricles. Results There was a significant correlation between asymmetry of brain lateral ventricles size and mean difference of horizontal diameter of thumb nails (P = 0.0001). A meaningful relation between brain hemispheres asymmetry and developmental delay (P = 0.04) was seen. Conclusion The asymmetry of thumbnails can be a marker for asymmetry of lateral ventricles and child developmental delays
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