9 research outputs found

    Joint topology design with routing and power control in ad hoc networks

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    Cataloged from PDF version of article.We discuss the problem of designing an ad hoc network topology by jointly using power control and routing. A well-designed topology in ad hoc networks provides several advantages: increasing the capacity, decreasing the complexity and reducing the power consumption. We formulate the topology design problem as an Integer Linear Programming (ILP) model. An optimal topology is designed subject to interference and connectivity constraints with three different objective functions and two power control approaches. Common transmit power (COMPOW) and the adaptive power (ADPOW) are the two different power control techniques used in this thesis. The objectives of the models that are used in the topology design are maximizing the number of established links, using shortest path routing strategy and minimizing the maximum traffic load over the most congested link by load balancing. Performance comparisons between two power control approaches with three different objectives in the topology design are achieved using numerical results on a sample network. Minimum end-to-end throughput, total throughput, total power consumption and the number of established links are used as the performance metrics. The numerical results show that selecting the optimal power for both power control approaches provides similar performance results. Therefore, simplicity of the COMPOW makes it more attractive than ADPOW in the topology design.Önal, AydoğanM.S

    Nutritional characteristic of children with inflammatory bowel disease in the nationwide inflammatory bowel disease registry from the Mediterranean region

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    © 2022, The Author(s), under exclusive licence to Springer Nature Limited.Background/objectives: We analyzed the nationwide pediatric inflammatory bowel disease (PIBD) registry (1998–2016), to evaluate the nutritional status at the time of diagnosis. Subjects/methods: Nine types of nutritional status by the combination of weight-for-length (2 years) and length/height-for-age with three categories (2 SD) were described. Malnutrition was defined by WHO criteria. Univariate and multivariate regression analysis was used to identify risk factors for malnutrition. Results: In total, 824 IBD patients (498 Ulcerative colitis (UC); 289 Crohn’s Disease (CD); 37 Indeterminate Colitis (IC); 412 male; the median age 12.5 years) were eligible. The prevalence of eutrophy, wasting/thinness, stunting, overweight, tall stature, concurrent wasting/thinness and stunting, tall stature with overweight, tall stature with wasting/thinness, and short stature with overweight were 67.4%, 14.9%, 6.6%, 3.1%, 3.2%, 3.3%, 1.1%, 0.4%, and 0.1%, respectively. The prevalence of malnutrition was 32.7%, indicating a higher prevalence in CD (p 10 years), prepubertal stage, severe disease activity, perianal involvement, and high C reactive protein level were independently associated with malnutrition in pediatric IBD. Conclusion: We showed the frequency of nutritional impairment in PIBD. The percentage of overweight subjects was lower than the other studies. The age of onset, disease activity, CRP level, perianal involvement, and pubertal stage were associated with a higher risk for developing malnutrition. Our results also confirmed that CD patients are particularly vulnerable to nutritional impairment. Clinical trial number: ClinicalTrials.gov Identifier: NCT04457518
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