4,645 research outputs found
Enhancing thermoelectric figure-of-merit by low-dimensional electrical transport in phonon-glass crystals
Low-dimensional electronic and glassy phononic transport are two important
ingredients of highly-efficient thermoelectric material, from which two
branches of the thermoelectric research emerge. One focuses on controlling
electronic transport in the low dimension, while the other on multiscale phonon
engineering in the bulk. Recent work has benefited much from combining these
two approaches, e.g., phonon engineering in low-dimensional materials. Here, we
propose to employ the low-dimensional electronic structure in bulk phonon-glass
crystal as an alternative way to increase the thermoelectric efficiency.
Through first-principles electronic structure calculation and classical
molecular dynamics simulation, we show that the - stacking
Bis-Dithienothiophene molecular crystal is a natural candidate for such an
approach. This is determined by the nature of its chemical bonding. Without any
optimization of the material parameter, we obtain a maximum room-temperature
figure of merit, , of at optimal doping, thus validating our idea.Comment: Nano Lett.201
Comorbidity and confounding factors in attention-deficit/hyperactivity disorder and sleep disorders in children
Sleep problems are commonly reported in children with attention-deficit/hyperactivity disorder (ADHD) symptoms. Research data regarding the complex and reciprocal relationship between ADHD and sleep disturbances has now accumulated. This paper is focused on the types of sleep problems that are associated with ADHD symptomatology, and attempts to untangle confounding factors and overlapping symptoms. The goal is also to present an updated overview of the pathophysiology of and treatment strategies for sleep problems in children with ADHD. The review also points out that future research will be needed to clarify further the other psychiatric comorbidities and side effects of medication in order to improve treatment outcomes and prevent misdiagnosis in clinical practice
A primal-dual interior-point relaxation method with adaptively updating barrier for nonlinear programs
Based on solving an equivalent parametric equality constrained mini-max
problem of the classic logarithmic-barrier subproblem, we present a novel
primal-dual interior-point relaxation method for nonlinear programs. In the
proposed method, the barrier parameter is updated in every step as done in
interior-point methods for linear programs, which is prominently different from
the existing interior-point methods and the relaxation methods for nonlinear
programs. Since our update for the barrier parameter is autonomous and
adaptive, the method has potential of avoiding the possible difficulties caused
by the unappropriate initial selection of the barrier parameter and speeding up
the convergence to the solution. Moreover, it can circumvent the jamming
difficulty of global convergence caused by the interior-point restriction for
nonlinear programs and improve the ill conditioning of the existing primal-dual
interiorpoint methods as the barrier parameter is small. Under suitable
assumptions, our method is proved to be globally convergent and locally
quadratically convergent. The preliminary numerical results on a well-posed
problem for which many line-search interior-point methods fail to find the
minimizer and a set of test problems from the CUTE collection show that our
method is efficient.Comment: submitted to SIOPT on April 14, 202
Reliable Data Transmission through Private CBRS Networks
We consider the use of a domain proxy assisted private citizen broadband
radio service (CBRS) network and propose a Maximum Transmission Continuity
(MTC) scheme to transmit Internet of Things (IoT) data reliably. MTC
dynamically allocates available CBRS channels to sustain the continuity of data
transmission without violating the channel access requirements. MTC allocates
the granted CBRS channels according to the priority of each user, the instant
channel access status, interference among users, and the fairness. The
simulation results demonstrate the improvement in managing reliable IoT data
transmission in the private CBRS network.Comment: 5 pages, 5 figure
Extensive Reading with Guidance
A language learning mode called “word-focused extensive reading” has been proposed to facilitate word-usage learning. The user inputs a word in the computer program designed and implemented for reading to find its usage in the context of a sentence. The computer program then searches for the knowledge base for the word and provides guidance to show a summary of the salient features of word collocation. Sentences with the word in question are displayed one at a time. For each sentence the relevant collocating words are highlighted. In this way the reader sees the word collocation so as to recognize the salient features of the word and thus incrementally acquires the knowledge of word usage. The program works with large Chinese and English collections of texts. For Chinese the knowledge of word collocation was built on the basis of the Balanced Corpus of Academia Sinica. The English collocation features were collected from the British National Corpus. The program can also be useful for learning to differentiate near-synonyms
The Relationship Between Information Transparency And The Informativeness Of Accounting Earnings
The issue of corporate governance has prompted calls for greater transparency and disclosure on companies around the world. As a result, a disclosure ranking system, Information Transparency and Disclosure Ranking System (ITDRS) was launched in Taiwan since 2003 by the request of Taiwan Stock Exchange Corporation (TSEC). This paper examines the relationship between information transparency and the informativeness of accounting earnings. The empirical tests are conducted using TEJ database for firms listed on the Taiwan Stock Exchange with fiscal year ends between 2003 and 2004. Empirical results indicate that, information transparency, measured by the ranking of ITDRS, reduces the informativeness of accounting earnings. However, if information transparency is measured by the ratio of long-term investment in stocks, evidences show higher earnings response coefficients (ERC) for the more transparent firms. The results suggest that accounting numbers are more useful or valuable than the ITDRS ranking results from investors’ perspective. It also suggests that the ITDRS may be not a good proxy for financial transparency
A lack of association between genetic polymorphisms in beta-defensins and susceptibility of psoriasis in Taiwanese: A case–control study
AbstractBackgroundGenetic predisposition of the inflammatory-host response may affect the development of psoriasis. Previous studies have shown that copy number variations (CNVs) of β-defensin genes (DEFB) are associated with the susceptibility of psoriasis in Caucasian populations.ObjectivesThis study aimed to assess the role of the CNVs of the DEFB4 gene and functional variants in the DEFB1 gene in Taiwanese patients with psoriasis.MethodsIn total, 196 patients with psoriasis and 196 control individuals were analyzed for the presence of the DEFB4 CNVs using the paralogue ratio test, and also for the DEFB1 polymorphisms rs11362, rs1800972, and rs1799946, using a polymerase chain reaction.ResultsNone of the polymorphisms were found to be associated with psoriasis. The distribution of DEFB4 genomic CNVs did not significantly differ between the control group and psoriasis group. The frequencies of patients who carried a greater than the median (≥ 5) number of copies did not significantly differ in patients with psoriasis and controls. The multivariate analysis similarly revealed that the DEFB4 CNVs were not associated with psoriasis (odds ratio = 1.03, 95% confidence interval = 0.89–1.19, p = 0.720). No significant difference was detected in the genotype and allele distribution for any of the individual DEFB1 polymorphisms between the cases and the controls. Finally, the overall haplotype frequency profiles derived from the three polymorphisms did not significantly differ between the cases and the controls.ConclusionOur results do not suggest that these genetic variants of the β-defensin genes contribute to the genetic background of psoriasis in Taiwanese patients
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