4,224 research outputs found

    Data-Discriminants of Likelihood Equations

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    Maximum likelihood estimation (MLE) is a fundamental computational problem in statistics. The problem is to maximize the likelihood function with respect to given data on a statistical model. An algebraic approach to this problem is to solve a very structured parameterized polynomial system called likelihood equations. For general choices of data, the number of complex solutions to the likelihood equations is finite and called the ML-degree of the model. The only solutions to the likelihood equations that are statistically meaningful are the real/positive solutions. However, the number of real/positive solutions is not characterized by the ML-degree. We use discriminants to classify data according to the number of real/positive solutions of the likelihood equations. We call these discriminants data-discriminants (DD). We develop a probabilistic algorithm for computing DDs. Experimental results show that, for the benchmarks we have tried, the probabilistic algorithm is more efficient than the standard elimination algorithm. Based on the computational results, we discuss the real root classification problem for the 3 by 3 symmetric matrix~model.Comment: 2 table

    Kufor-Rakeb syndrome, pallido-pyramidal degeneration with supranuclear upgaze paresis and dementia, maps to 1p36

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    Kufor-Rakeb syndrome is an autosomal recessive nigro-striatal-pallidal-pyramidal neurodegeneration. The onset is in the teenage years with clinical features of Parkinson’s disease plus spasticity, supranuclear upgaze paresis, and dementia. Brain scans show atrophy of the globus pallidus and pyramids and, later, widespread cerebral atrophy. We report linkage in Kufor- Rakeb syndrome to a 9 cM region of chromosome 1p36 delineated by the markers D1S436 and D1S2843, with a maximum multipoint lod score of 3.6. (J Med Genet 2001;38:680–682

    One-minute rain rate statistics prediction using Ito-Hosoya model in Malaysia

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    This paper investigates one-minute rain rate in Kuala Lumpur, Malaysia predicted based on Ito-Hosoya model. The model is categorized into meteorological based model as it receives as input local meteorological parameter. The best part about this model is it does not requires measured rain rate data to be converted into one-minute, instead it depends on long-term meteorological parameter values which widely available from various sources. In this paper, the local meteorological parameters are extracted from TRMM database which are average accumulation rainfall (from TMPA 3B43) and thunderstorm ratio (from TRMM PR 3A25 and TMI 3A12). The result shows that this model could be promising for use in Malaysia region as it produces better performance compared to the ITU-R model

    Treatment of gastrointestinal stromal tumor: focus on imatinib mesylate

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    Gastrointestinal stromal tumor (GIST) is a rare primary neoplasm of the gastrointestinal tract, mesentery, or omentum. In the past, surgery has been the only effective treatment. The diagnosis and treatment of GIST has been revolutionized over the past decade, since expression of the receptor tyrosine kinase KIT was shown to occur on these tumors. Mutations in this proto-oncogene commonly cause constitutive activation of the KIT tyrosine kinase receptor, an important factor in the pathogenesis of the disease. The development of specific tyrosine kinase inhibitors, such as imatinib mesylate, has led to a breakthrough in the treatment of advanced GIST. Treatment with this drug has led to significant improvements in survival, with overall response rates in excess of 80%. Side effects are common, but usually manageable. The success of this drug has led to further trials investigating its use in the pre- and postoperative situation. This review summarizes the current knowledge of GIST and imatinib treatment and possible future developments

    Implementation of adaptive coding and modulation for satellite communication links in heavy rain region: an operators perspective

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    This contribution presents an implementation of adaptive modulation and coding (ACM) for the real operating satellite- based internet protocol (IP) communication system from the Nigeria communication satellite (NigComSat-1R) very small aperture terminal (VSAT) network. Specifically, different modulation schemes are chosen according to the weather conditions in order to achieve the highest available data rate and preserve the link availability. The experimental results indicate that at least a 24% bandwidth reduction can be achieved with the same data rate by implementing the ACM technique. Further work should focus on the ACM selection strategy based on the peculiarities of the meteorological characteristics in a specific area so that ACM implementation will lead to maximum efficiency in terms of radio resource management and exploitation

    It's all about me! The Influence of Personality on Susceptibility to Mobile Security Attacks

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    Design of a cell selection mechanism to mitigate interference for cell-edge macro users in femto-macro heterogeneous network

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    The Femto-Macro heterogeneous network is a promising solution to improve the network capacity and coverage in mobile network. However interference may rise due to femtocell deployment nearby to macro user equipment (MUE) within macrocell network coverage. Femtocell offers main priority in resource allocation to its subscribed femto user equipment (FUE) rather than unsubscribed MUE. MUEs will suffer severe interference when they are placed near or within the femtocell area range especially at the cell edge. This phenomenon occurs due to the distance is far from its serving macro base station (MBS) to receive good signal strength. This paper presents a design of cell selection scheme for cell-edge MUE to select an optimal femto base station (FBS) as its primary serving cell in physical resource block allocation. In this study, the proposed cell selection consists of four main elements: measuring the closest FBS distance, Signal to Interference-plus-Noise-Ratio (SINR), physical resource block (PRB) availability and node density level for the selected base station. The main goal is to ensure cell-edge MUE has priority fairly with FUE in physical resource block allocation per user bandwidth demand to mitigate interference. Hence, the cell-edge MUE has good experienced on receiving an adequate user data rate to improve higher network throughput
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