6,271 research outputs found
Testing for a General Class of Functional Inequalities
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
functionals of kernel-type estimators 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
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
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
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
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
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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