6,271 research outputs found

    Testing for a General Class of Functional Inequalities

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    In this paper, we propose a general method for testing inequality restrictions on nonparametric functions. Our framework includes many nonparametric testing problems in a unified framework, with a number of possible applications in auction models, game theoretic models, wage inequality, and revealed preferences. Our test involves a one-sided version of LpL_{p} functionals of kernel-type estimators (1p<)(1\leq p <\infty ) and is easy to implement in general, mainly due to its recourse to the bootstrap method. The bootstrap procedure is based on nonparametric bootstrap applied to kernel-based test statistics, with estimated "contact sets." We provide regularity conditions under which the bootstrap test is asymptotically valid uniformly over a large class of distributions, including the cases that the limiting distribution of the test statistic is degenerate. Our bootstrap test is shown to exhibit good power properties in Monte Carlo experiments, and we provide a general form of the local power function. As an illustration, we consider testing implications from auction theory, provide primitive conditions for our test, and demonstrate its usefulness by applying our test to real data. We supplement this example with the second empirical illustration in the context of wage inequality.Comment: 128 page

    Testing functional inequalities

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    This paper develops tests for inequality constraints of nonparametric regression functions. The test statistics involve a one-sided version of L p-type functionals of kernel estimators. Drawing on the approach of Poissonization, this paper establishes that the tests are asymptotically distribution free, admitting asymptotic normal approximation. Furthermore, the tests have nontrivial local power against a certain class of local alternatives converging to the null at the rate of n -1/2 . Some results from Monte Carlo simulations are presented.

    Supersymmetric Higgs Boson Decays in the MSSM with Explicit CP Violation

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    Decays into neutralinos and charginos are among the most accessible supersymmetric decay modes of Higgs particles in most supersymmetric extensions of the Standard Model. In the presence of explicitly CP--violating phases in the soft breaking sector of the theory, the couplings of Higgs bosons to charginos and neutralinos are in general complex. Based on a specific benchmark scenario of CP violation, we analyze the phenomenological impact of explicit CP violation in the Minimal Supersymmetric Standard Model on these Higgs boson decays. The presence of CP--violating phases could be confirmed either directly through the measurement of a CP--odd polarization asymmetry of the produced charginos and neutralinos, or through the dependence of CP--even quantities (branching ratios and masses) on these phases.Comment: 14 pages, latex, 4 eps figure

    Optimal Precoder Designs for Sum-utility Maximization in SWIPT-enabled Multi-user MIMO Cognitive Radio Networks

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    In this paper, we propose a generalized framework that combines the cognitive radio (CR) techniques for spectrum sharing and the simultaneous wireless information and power transfer (SWIPT) for energy harvesting (EH) in the conventional multi-user MIMO (MuMIMO) channels, which leads to an MuMIMO-CR-SWIPT network. In this system, we have one secondary base-station (S-BS) that supports multiple secondary information decoding (S-ID) and secondary EH (S-EH) users simultaneously under the condition that interference power that affects the primary ID (P-ID) receivers should stay below a certain threshold. The goal of the paper is to develop a generalized precoder design that maximizes the sum-utility cost function under the transmit power constraint at the S-BS, and the EH constraint at each S-EH user, and the interference power constraint at each P-ID user. Therefore, the previous studies for the CR and SWIPT systems are casted as particular solutions of the proposed framework. The problem is inherently non-convex and even the weighted minimum mean squared error (WMMSE) transformation does not resolve the non-convexity of the original problem. To tackle the problem, we find a solution from the dual optimization via sub-gradient ellipsoid method based on the observation that the WMMSE transformation raises zero-duality gap between the primal and the dual problems. We also propose a simplified algorithm for the case of a single S-ID user, which is shown to achieve the global optimum. Finally, we demonstrate the optimality and efficiency of the proposed algorithms through numerical simulation results.Comment: 12pages, 9 figures, submitted to IEEE Systems Journa

    Dissociation of Akt1 from its negative regulator JIP1 is mediated through the ASK1–MEK–JNK signal transduction pathway during metabolic oxidative stress: a negative feedback loop

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    We have previously observed that metabolic oxidative stress–induced death domain–associated protein (Daxx) trafficking is mediated by the ASK1–SEK1–JNK1–HIPK1 signal transduction pathway. The relocalized Daxx from the nucleus to the cytoplasm during glucose deprivation participates in a positive regulatory feedback loop by binding to apoptosis signal–regulating kinase (ASK) 1. In this study, we report that Akt1 is involved in a negative regulatory feedback loop during glucose deprivation. Akt1 interacts with c-Jun NH2-terminal kinase (JNK)–interacting protein (JIP) 1, and Akt1 catalytic activity is inhibited. The JNK2-mediated phosphorylation of JIP1 results in the dissociation of Akt1 from JIP1 and subsequently restores Akt1 enzyme activity. Concomitantly, Akt1 interacts with stress-activated protein kinase/extracellular signal–regulated kinase (SEK) 1 (also known as MKK4) and inhibits SEK1 activity. Knockdown of SEK1 leads to the inhibition of JNK activation, JIP1–JNK2 binding, and the dissociation of Akt1 from JIP1 during glucose deprivation. Knockdown of JIP1 also leads to the inhibition of JNK activation, whereas the knockdown of Akt1 promotes JNK activation during glucose deprivation. Altogether, our data demonstrate that Akt1 participates in a negative regulatory feedback loop by interacting with the JIP1 scaffold protein

    Finding 9-1-1 Callers in Tall Buildings

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    Accurately determining a user’s floor location is essential for minimizing delays in emergency response. This paper presents a floor localization system intended for emergency calls. We aim to provide floor-level accuracy with minimum infrastructure support. Our approach is to use multiple sensors, all available in today’s smartphones, to trace a user’s vertical movements inside buildings. We make three contributions. First, we present a hybrid architecture for floor localization with emergency calls in mind. The architecture combines beacon-based infrastructure and sensor-based dead reckoning, striking the right balance between accurately determining a user’s location and minimizing the required infrastructure. Second, we present the elevator module for tracking a user’s movement in an elevator. The elevator module addresses three core challenges that make it difficult to accurately derive displacement from acceleration. Third, we present the stairway module which determines the number of floors a user has traveled on foot. Unlike previous systems that track users’ foot steps, our stairway module uses a novel landing counting technique
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