9,120 research outputs found

    An N-bit digitally variable ultra wideband pulse generator for GPR and UWB applications

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    This paper presents a low-cost Ultra Wideband (UWB) pulse generator that can vary the pulse duration digitally by using a Step Recovery Diode (SRD), microstrip transmission lines and PIN diodes. First, a sharp edge is generated by using a SRD circuitry. Then a pulse is formed from the sharp edge through the use of transmission lines and the PIN diodes. Based on the number of transmission lines (N), the duration of the pulse can be varied in steps. The UWB pulse generator circuits are implemented on an FR-4 substrate using microstrip line technology and UWB pulses with durations of 550 to 2400 psec are measured. N2 Ke

    State Complexity of Regular Tree Languages for Tree Matching

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    We study the state complexity of regular tree languages for tree matching problem. Given a tree t and a set of pattern trees L, we can decide whether or not there exists a subtree occurrence of trees in L from the tree t by considering the new language Lā€² which accepts all trees containing trees in L as subtrees. We consider the case when we are given a set of pattern trees as a regular tree language and investigate the state complexity. Based on the sequential and parallel tree concatenation, we define three types of tree languages for deciding the existence of different types of subtree occurrences. We also study the deterministic top-down state complexity of path-closed languages for the same problem.</jats:p

    The Importance of Binary Gravitational Microlensing Events Through High-Magnification Channel

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    We estimate the detection efficiency of binary gravitational lensing events through the channel of high-magnification events. From this estimation, we find that binaries in the separations ranges of 0.1 < s < 10, 0.2 < s < 5, and 0.3 < s < 3 can be detected with ~ 100% efficiency for events with magnifications higher than A=100, 50, and 10, respectively, where s represents the projected separation between the lens components normalized by the Einstein radius. We also find that the range of high efficiency covers nearly the whole mass-ratio range of stellar companions. Due to the high efficiency in wide ranges of parameter space, we point out that majority of binary-lens events will be detected through the high-magnification channel in lensing surveys that focus on high-magnification events for efficient detections of microlensing planets. In addition to the high efficiency, the simplicity of the efficiency estimation makes the sample of these binaries useful in the statistical studies of the distributions of binary companions as functions of mass ratio and separation. We also discuss other importance of these events.Comment: 5 pages, 1 figure, 1 tabl

    Trends in Cancer Screening Rates among Korean Men and Women: Results from the Korean National Cancer Screening Survey (KNCSS), 2004-2010

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    PURPOSE: The Korean National Cancer Screening Survey (KNCSS) is a continuous nationwide survey implemented by the National Cancer Center in Korea since 2004. The purpose of the present study was to report trends in cancer screening rates for the five major cancers (stomach, liver, colorectal, breast, and cervix uteri) in Korean men and women. MATERIALS AND METHODS: The study used KNCSS data collected between 2004 and 2010. The survey was conducted on Korean men aged 40-74 years and Korean women aged 30-74 years with no history of cancer diagnosis. The annual percentage change and corresponding 95% confidence intervals were used to examine changes in annual screening rates. RESULTS: Screening rates with recommendation increased by 4.4% annually for stomach cancer, 1.5% for liver cancer, 2.8% per year for colorectal cancer, 4.5% for breast cancer, and 1.2% for cervix uteri cancer. The increasing trend in cancer screening rates, with the exception of liver cancer, was significant. CONCLUSION: Cancer screening rates have increased consistently from 2004 to 2010 among Korean men and women. Stomach and breast cancer screening rates in particular have increased markedly.ope

    Trace element determination result for the USGS standard rocks BCR2, BIR1a and GSP2 during 2015-2019

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    Trace element concentrations of the US Geological Survey's basalt standards (BCR2, BIR1a) and a granite standard (GSP2) were determined during five years from 2015 to 2019. These data will be helpful for judging data quality of trace element concentrations determined for the geochemical interpretation at KIGAM trace-isotope team. In addition, our data also include measurements of some elements whose recommendation values are not available in the US Geological Survey report

    Erratum to: A genome-wide assessment of genetic diversity and population structure of Korean native cattle breeds

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    Background: The native cattle breeds are an important genetic resource for meat and milk production throughout Asia. In Asia cattle were domesticated around 10,000 years ago and in Korea cattle are being raised since 2000 B.C. There are three native breeds of cattle in Korea viz. Brown Hanwoo, Brindle Hanwoo and Jeju Black. While one of these breeds, Brown Hanwoo, is a part of a Food and Agricultural Organization and national genetic evaluation plans, others get little attention. This study is an effort to understand and provide a detailed insight into the population structure and genetic variability of the Korean cattle breeds along with other Asian breeds using various methods. In this study we report the genetic variation and structure of the Korean cattle breeds and their comparison with five other Asian cattle breeds along with a panel of animals from European taurine, African taurine and indicine cattle breeds. Results: Asian cattle were found to be least differentiated which reflects their recent history. Amongst the Asian breeds Hainan, which is an indicine breed, had the lowest gene diversity while Yanbian had the highest followed by Mongolian and Korean cattle. Amongst the Korean breeds Brown Hanwoo had the highest diversity followed by Brindle Hanwoo and Jeju Black. The genetic diversity in Asian cattle breeds was found comparable to the European taurines and more than the African taurines and Zebu cattle. Korean cattle breed, Brown Hanwoo was consistently found to be closer to Yanbian, a Chinese cattle breed. We found low divergence and moderate levels of genetic diversity among the native Korean breeds. Indicine introgression from Hainan was seen in other Asian breeds. From Europe, Limousin, Holstein and Hereford introgression was found in Asian breeds. Conclusions: In this study we provide a genome-wide insight into the genetic history of the native cattle breeds of Korea. The outcomes of this study will help in prioritization and designing of the conservation plans
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