The error performance of Gray encoded QPSK and 8-PSK schemes in afading channel with cochannel interference

Closed-form BER (bit error rate) expressions are derived for Gray-encoded QPSK (quadrature phase shift keying) and 8-PSK schemes using coherent detection in a slow Rayleigh fading narrowband channel with fading cochannel interference. Earlier work has been limited to deriving the approximate BER using the canonical Stein (1961) receiver concept. The symbol error rate (SER) for the QPSK scheme is also derived. The desired signal and the cochannel interferer are both PSK signals, modulated by different baseband pulses with identical signaling rate     

Mining gene–sample–time microarray data: a coherent gene cluster discovery approach

Extensive studies have shown that mining microarray data sets is important in bioinformatics research and biomedical applications. In this paper, we explore a novel type of gene–sample–time microarray data sets that records the expression levels of various genes under a set of samples during a series of time points. In particular, we propose the mining of coherent gene clusters from such data sets. Each cluster contains a subset of genes and a subset of samples such that the genes are coherent on the samples along the time series. The coherent gene clusters may identify the samples corresponding to some phenotypes (e.g., diseases), and suggest the candidate genes correlated to the phenotypes. We present two efficient algorithms, namely the Sample-Gene Search and the Gene–Sample Search, to mine the complete set of coherent gene clusters. We empirically evaluate the performance of our approaches on both a real microarray data set and synthetic data sets. The test results have shown that our approaches are both efficient and effective to find meaningful coherent gene clusters. Daxin Jiang received the Ph.D. degree in computer science and engineering from the State University of New York at Buffalo in 2005. He received the B.S. degree in computer science from the University of Science and Technology of China. From 1998 to 2000, he was a M.S. student in Software Institute, Chinese Academy of Sciences. He is currently an assistant professor at the School of Computer Engineering, Nanyang Technology University, Singapore. His research interests include data mining, bioinformatics, machine learning, and information retrieval. Jian Pei received the Ph.D. degree in computing science from Simon Fraser University, Canada, in 2002, under Dr. Jiawei Han's supervision. He also received the B.Eng. and the M.Eng. degrees from Shanghai Jiao Tong University, China, in 1991 and 1993, respectively, both in Computer Science. He is currently an assistant professor of computing science at Simon Fraser University. His research interests include developing effective and efficient data analysis techniques for novel data intensive applications. He is currently interested in various techniques of data mining, data warehousing, online analytical processing, and database systems, as well as their applications in bioinformatics. His current research is supported in part by the Natural Sciences and Engineering Research Council of Canada (NSERC) and the National Science Foundation (NSF) of the United States. Since 2000, he has published over 70 research papers in refereed journals, conferences, and workshops, has served in the organization committees and the program committees of over 60 international conferences and workshops, and has been a reviewer for some leading academic journals. He is a member of the ACM, the ACM SIGMOD, and the ACM SIGKDD. Murali Ramanathan is an associate professor of pharmaceutical sciences and neurology. He received the B.Tech. (Honors) in chemical engineering from the Indian Institute of Technology, India, in 1983. After a 4-year stint in the chemical industry, he obtained the M.S. degree in chemical engineering from Iowa State University, Ames, IA, in 1987, and the Ph.D. degree in bioengineering from the University of California-San Francisco and University of California-Berkeley Joint Program in Bioengineering in 1994. Dr. Ramanathan research interests are primarily focused on the treatment of multiple sclerosis (MS), an inflammatory-demyelinating disease of the central nervous system that affects over 1 million patients worldwide. MS is a complex, variable disease that causes physical and cognitive disability and nearly 50% of patients diagnosed with MS are unable to walk after 15 years. The etiology and pathogenesis of MS remains poorly understood. Dr. Ramanathan's research interests include stochastic modeling of pharmaceutical systems and novel approaches to analyzing and using genetic and genomic data for improving patient care and optimizing therapy. Chuan Lin is currently a Ph.D. student in the Department of Computer Science and Engineering, State University of New York at Buffalo. She received the B.E. and the M.S. degrees in computer science and technology from Tsinghua University in China. Her research interests include bioinformatics, data mining, and machine learning. Chun Tang received the B.S. and M.S. degrees from Peking University, China, in 1996 and 1999, respectively, and the Ph.D. degree from State University of New York at Buffalo, USA, in 2005, all in computer science. Currently, she is a postdoctoral associate of Center for Medical Informatics, Yale University. Her research interests include bioinformatics, data mining, machine learning, database, and information retrieval. Aidong Zhang received the Ph.D. degree in computer science from Purdue University, West Lafayette, Indiana, in 1994. She was an assistant professor from 1994 to 1999, an associate professor from 1999 to 2002, and has been a professor since 2002 in the Department of Computer Science and Engineering at State University of New York at Buffalo. Her research interests include multimedia systems, content-based image retrieval, bioinformatics, and data mining. She is an author of over 140 research publications in these areas. Dr. Zhang's research has been funded by NSF, NIH, NIMA, and Xerox. Zhang serves on the editorial boards of International Journal of Bioinformatics Research and Applications (IJBRA), ACM Multimedia Systems, International Journal of Multimedia Tools and Applications, and International Journal of Distributed and Parallel Databases. She was the editor for ACM SIGMOD DiSC (Digital Symposium Collection) from 2001 to 2003. She was co-chair of the technical program committee for ACM Multimedia in 2001. She has also served on various conference program committees. Dr. Zhang is a recipient of the National Science Foundation CAREER award and SUNY Chancellor's Research Recognition award.     

Gate bias polarity dependence of charge trapping and time-dependentdielectric breakdown in nitrided and reoxidized nitrided oxides

The gate bias polarity dependence of charge trapping and time-dependent dielectric breakdown (TDDB) in nitrided and reoxidized nitrided silicon dioxides prepared by rapid thermal processing (RTP) is reported. Charge trapping during high-field injection can be reduced by rapid thermal nitridation for both substrate and gate injection. While reoxidation of nitrided oxides shows further reduction in charge trapping for substrate injection, degradation is observed for gate injection. Similar effects are observed for TDDB: reoxidized nitrided oxides show charge-to-breakdown in excess of 300 C/cm² for substrate injection, but less than 30 C/cm² for gate injection. These effects are related to the nitrogen and hydrogen profiles in the oxides. By tailoring the process conditions, a symmetric behavior of NO and RONO films with low charge trappings and Q _BD in excess of 50 C/cm² is possible, making them attractive as long-lifetime dielectrics from EEPROM (electrically erasable programmable ROM) and flash EEPROM technologies     

Characteristics of slurry coated CdSeTe films

CdSe_xTe_1?x films were deposited by the slurry coating technique using CdSe_xTe_1?x powders synthesized in the laboratory. X-ray diffraction studies indicated the formation of a hexagonal phase. From EDAX compositional analysis, the individual concentrations of Se and Te in the films were estimated. Analysis of the optical data indicate the band gap to vary from 1.44 to 1.68 eV as the value of ‘x’ changes from 0 to 1. XPS analysis was also carried out on the films. The films were used as photoanodes in polysulphide electrolyte and it was observed that the films with composition CdSe_0.6Te_0.4 exhibited the maximum photoactivity. The Mott–Schottky plot indicated an n-type behaviour. Spectral response measurements were made and the electrodes exhibited a quantum efficiency of 0.6.     

Formation of BaCrO4 NanoCrystallites within Thermally Evaporated Sodium Bis-2-Ethylhexyl-Sulfosuccinate and Stearic Acid Thin Films

This paper describes the growth of barium chromate (BaCrO₄) nanocrystallites within thermally evaporated thin films of stearic acid (StA) and sodium bis-2-ethylhexyl-sulfosuccinate by a process of Ba²⁺ ion entrapment followed by in situ reaction with CrO₄²⁻ ions. Dense spherical assemblies of BaCrO₄ nanocrystallites of very uniform size (∼50 nm) were obtained within the two different host matrices. The spherical assemblies were composed of smaller (ca. 5–10 nm size) BaCrO₄ crystals indicating that efficient size control over crystal size may be exercised by the matrix. Contact angle measurements of the BaCrO₄–StA and BaCrO₄–sodium bis-2-ethylhexyl-sulfosuccinate films indicated that they were hydrophobic, thus pointing to the possible role of hydrophobic interaction between the StA and sodium bis-2-ethylhexyl-sulfosuccinate monolayer-covered BaCrO₄ crystals in the assembly process.     

Optimal Distributed Location Management in Mobile Networks

An important issue in the design of future Personal Communication Services (PCS) networks is the efficient management of location information. In this paper, we consider a distributed database architecture for location management in which update and query loads of the individual databases are balanced. We obtain lower bounds to the worst-case delay in locating a mobile user, to the average delay, and to the call blocking probability. We then propose a dynamic location management algorithm that meets these lower bounds. The optimality of this algorithm with respect to these three performance measures, as well as simplicity, make it an appealing candidate for distributed location management in PCS networks.     

Synthesis of flexible polymeric shielding materials for soft gamma rays: Physicomechanical and attenuation characteristics of radiation crosslinked polydimethylsiloxane/Bi2O3 composites

Flexible lead‐free high energy radiation shielding material was developed through internal compounding. Polymer‐filler interaction, crosslinking density, specific gravity, physicomechanical characteristics, percentage attenuation, and thermal stability of the crosslinked composites were estimated. It was found that even at very high filler loading composites can be crosslinked; however, the crosslinking density was composition dependent and was highest in 10–50 wt% loading range at 100 kGy and 200 kGy. The Nielsen model was applied to understand the micromechanics of the system. Attenuation of gamma radiation from Am241 was not affected by the crosslinking density. Thermal stability of the composites was found to be significantly affected with bismuth oxide loading. POLYM. COMPOS., 37:756–762, 2016. © 2014 Society of Plastics Engineers     

具有联网功能的家用设备

现在,人人都能使用互联网,它具有采集新闻和内容共享到实时通信多种多样的用途.这些活动主要通过个人计算机和智能手机实现,而在家里联网电视已开始担当这个角色.     

On the Role of Contact Resistance and Electrode Modification in Organic Electrochemical Transistors

Contact resistance is renowned for its unfavorable impact on transistor performance. Despite its notoriety, the nature of contact resistance in organic electrochemical transistors (OECTs) remains unclear. Here, by investigating the role of contact resistance in n‐type OECTs, the first demonstration of source/drain‐electrode surface modification for achieving state‐of‐the‐art n‐type OECTs is reported. Specifically, thiol‐based self‐assembled monolayers (SAMs), 4‐methylbenzenethiol (MBT) and pentafluorobenzenethiol (PFBT), are used to investigate contact resistance in n‐type accumulation‐mode OECTs made from the hydrophilic copolymer P‐90, where the deliberate functionalization of the gold source/drain electrodes decreases and increases the energetic mismatch at the electrode/semiconductor interface, respectively. Although MBT treatment is found to increase the transconductance three‐fold, contact resistance is not found to be the dominant factor governing OECT performance. Additional morphology and surface energy investigations show that increased performance comes from SAM‐enhanced source/drain electrode surface energy, which improves wetting, semiconductor/metal interface quality, and semiconductor morphology at the electrode and channel. Overall, contact resistance in n‐type OECTs is investigated, whilst identifying source/drain electrode treatment as a useful device engineering strategy for achieving state of the art n‐type OECTs.     

Multiplex PCR-based strategy to detect contamination with mycotoxigenic Fusarium species in rice and fingermillet collected from southern India

BACKGROUND: The genus Fusarium comprises a diverse group of fungi including several species that produce mycotoxins in food commodities. In the present study, a multiplex PCR was standardised for the group‐specific detection of fumonisin‐producing and trichothecene‐producing strains of Fusarium species. Primers for genus‐level recognition of Fusarium spp. were designed from the internal transcribed spacer regions 1 and 2 of rDNA. Primers for group‐specific detection were designed from the tri5 and tri6 genes involved in trichothecene biosynthesis and the fum1 and fum13 genes involved in fumonisin biosynthesis. RESULTS: Among the various genera and their strains tested, all the 85 confirmed Fusarium strains were positive for rDNA gene and the rest stayed negative. From among the Fusarium strains, 15 had amplification for trichothecene‐ and 20 for fumonisin‐encoding genes. All PCR positive trichothecene chemotypes of Fusarium species tested were positive for chemical analysis but in the case of fumonisins, of the 20 PCR positive cultures, only 13 showed positive for chemical analysis by HPTLC. CONCLUSION: The assay described here provided a rapid and reliable detection of trichothecene‐ and fumonisin‐producing Fusarium directly from natural food grains and the results were always comparable with a conventional HPTLC detection method. It can, therefore, be used by the food industry to monitor quality and safety. Copyright © 2011 Society of Chemical Industry