4,925 research outputs found

    Lower bounds for Arrangement-based Range-Free Localization in Sensor Networks

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    Colander are location aware entities that collaborate to determine approximate location of mobile or static objects when beacons from an object are received by all colanders that are within its distance RR. This model, referred to as arrangement-based localization, does not require distance estimation between entities, which has been shown to be highly erroneous in practice. Colander are applicable in localization in sensor networks and tracking of mobile objects. A set S⊂R2S \subset {\mathbb R}^2 is an (R,ϵ)(R,\epsilon)-colander if by placing receivers at the points of SS, a wireless device with transmission radius RR can be localized to within a circle of radius ϵ\epsilon. We present tight upper and lower bounds on the size of (R,ϵ)(R,\epsilon)-colanders. We measure the expected size of colanders that will form (R,ϵ)(R, \epsilon)-colanders if they distributed uniformly over the plane

    Nonesophageal Eosinophilic Gastrointestinal Disorders: Clinical Care and Future Directions

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    Eosinophilic gastrointestinal disorders are a set of conditions with a wide range of clinical manifestations and treatment modalities. The disorders are suspected to result from an abnormal inflammatory response to allergen(s), and individuals may develop a relapsing or chronic disease, if the allergen is not eliminated. Mechanisms of disease pathogenesis, including the humoral immune response, need to be fully elucidated. A variety of therapies are used, though there is a lack of well-defined randomized, prospective studies. Other therapeutic options are needed as the current treatments have potential concerns; elimination diets may impair a child’s quality of life, and corticosteroids have adverse risks with long-term use. We review what is known about non-esophageal eosinophilic gastrointestinal disorders, and discuss research investigations which need to be conducted to facilitate diagnosis and enhance treatment methods

    Steroids in pediatric eosinophilic esophagitis

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    Swallowed fluticasone and oral viscous budesonide are effective first-line therapies for eosinophilic esophagitis in children. Side effects are minimal without evidence of Cushing syndrome, as seen in treatment with systemic corticosteroids. New studies on alternative delivery systems and different corticosteroids (eg, ciclesonide) are encouraging. As knowledge of corticosteroids in eosinophilic esophagitis expands, newer questions continue to arise concerning dose, delivery, and choice of corticosteroids; long-term adverse effects; and maintenance therapies

    The STRESS Method for Boundary-point Performance Analysis of End-to-end Multicast Timer-Suppression Mechanisms

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    Evaluation of Internet protocols usually uses random scenarios or scenarios based on designers' intuition. Such approach may be useful for average-case analysis but does not cover boundary-point (worst or best-case) scenarios. To synthesize boundary-point scenarios a more systematic approach is needed.In this paper, we present a method for automatic synthesis of worst and best case scenarios for protocol boundary-point evaluation. Our method uses a fault-oriented test generation (FOTG) algorithm for searching the protocol and system state space to synthesize these scenarios. The algorithm is based on a global finite state machine (FSM) model. We extend the algorithm with timing semantics to handle end-to-end delays and address performance criteria. We introduce the notion of a virtual LAN to represent delays of the underlying multicast distribution tree. The algorithms used in our method utilize implicit backward search using branch and bound techniques and start from given target events. This aims to reduce the search complexity drastically. As a case study, we use our method to evaluate variants of the timer suppression mechanism, used in various multicast protocols, with respect to two performance criteria: overhead of response messages and response time. Simulation results for reliable multicast protocols show that our method provides a scalable way for synthesizing worst-case scenarios automatically. Results obtained using stress scenarios differ dramatically from those obtained through average-case analyses. We hope for our method to serve as a model for applying systematic scenario generation to other multicast protocols.Comment: 24 pages, 10 figures, IEEE/ACM Transactions on Networking (ToN) [To appear

    An integrated control/structure design method using multi-objective optimization

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    The benefits are demonstrated of a multiobjective optimization based control structure integrated design methodology. An application of the proposed CSI methodology to the integrated design of the Spacecraft COntrol Lab Experiment (SCOLE) configuration is presented. Integrated design resulted in reducing both the control performance measure and the mass. Thus, better overall performance is achieved through integrated design optimization. The mutliobjective optimization approach used provides Pareto optimal solutions by unconstrained minimization of a differentiable KS function. Furthermore, adjusting the parameters gives insight into the trade-offs involved between different objectives

    Influence of prolonged disposal of municipal solid waste on soil productivity factors

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    The prolonged disposal of municipal waste influences the soil productivity factors. Therefore, the present study was carried out at dumping site near Chandi bridge Hardwar (Uttarakhand) to determine the effect of physico-chemical parameters of the solid waste on soil productivity factors of soil at different sites-  Site-A: It was near to slump area. Site-B (500 meter far from site-A: It was used for dumping and partially submerged with water and had a swampy condition, Site-C (500 meter far from site-B): It was near to Chandi devi ropeway and contained fresh as well as partially decomposed waste. Site- D and Site-E (500 meter far from site-C): It was used for dumping and had putrefied odour due to decomposition of fresh waste. The control site- X (Bilkeshwar mountain region): 10 Km far from experimental sites in N-W direction of Chandi bridge municipal waste dumping area at Hardwar (Uttarakhand), India during the year 2006-2009 at present these sites have been closed for dumping of waste. The soil productivity factors viz. available nitrogen (0.32 ppm), organic matter (0.89%) were found maximum at site-A, temperature (24.610C) at site-C and electrical conductivity (1.05 dSM-1) available phosphorus (33.16ppm), available potash (260.17ppm) at site-E of dumping area in comparison to the soil of control site-X (Bilkeshwar mountain range). At control site, bulk density (1.37 g/cc) and pH (7.65) were maximum while the bulk density (1.08 ± 0.22) g/cc at site-D and pH (7.02) at site-E were observed minimum. The results were statistically analyzed to indicate that the dumping of municipal waste influenced the pH and bulk density of soil and increased the acidity and porosity of soil through which pollutants leach to ground water. But higher amount of organic matter, N, P, K makes it fit for the raw material that may be used in fertilizing industries by using appropriate technologies. The study would be helpful for utilization of  municipal wastes   in compost formation and to indicate the influence of municipal waste on soil quality of the dumping sites of other places.&nbsp
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