http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
오늘 본 자료
A modified tone injection scheme for PAPR reduction using genetic algorithm
이원철,최주평,Chuyen Khoa Huynh 한국통신학회 2015 ICT Express Vol.1 No.2
Owing to the capability to provide a wide variety of intelligent behaviors, cognitive radio (CR) has become a promising technology to improve spectrum utilization efficiently. One of the popular techniques which adapt CR concept to multi-carrier systems is known as tone injection scheme. This scheme is a sort of peak-to-average-power ratio (PAPR) reduction methods deployable to multi-carrier systems such as orthogonal frequency division multiplexing (OFDM). However, a conventional tone injection scheme might increase averaged transmit power attributed to expanding the size of constellation on purpose to get optimal PAPR reduction. Based on a weighted-sum genetic algorithm to resolve multi-objective optimization problem (MOOP), the modified tone injection scheme exploits the agility of CR technology to rapidly adapt operating parameters in order to fulfill PAPR reduction as well as mitigation of power increase optimally. The simulation results verify that the proposed scheme is flexible because it could not only control the performance of PAPR reduction, but also alleviate power increase by steering weight values at the expense of relatively low complexity comparing with other conventional method.
이원철,Lee, Won-Cheol 한국건설안전협회 1992 建設 安全技術 Vol.2 No.3
건설현장에서 대형사고의 발생시 그 원인과 대책, 책임의 소재를 시행사, 감독관, 감리자에게 묻고 있는바, 현장주재 감리자로서 업무의 범위, 수행 과정상의 문제점 및 개선점 등에 대하여 요약 기술하고자 한다. <필자 주>
건강검진 총괄 : 우리나라 국가건강검진 현황 및 발전방향
이원철,이순영 대한의사협회 2010 대한의사협회지 Vol.53 No.5
National Health Screening Program of Korea for chronic diseases was started in 1980. During the last 20 years, the problems of the program has been discussed. The problems discusses were as follows: (1) The current guideline is based on weak rationale, without concrete evidence-based decisions (2), The goal of the screening program was not set based on evidence, and there has been no evaluation for the effectiveness of the program (3), the program consists of test items without the diseases (4), the program was run by separate municipalities,so it was not organized for the subjects, and finally (5), there has been no remarkable reduction in incidence or prevalence of the related diseases. To improve the program, there have been many efforts including new national screening program called‘National screening program for the transitional period’in 2007 and launching the National Health Screening Act in 2009. The brief history of the National Health Screening program of Korea was reviewed. The Goal of the National Screening program is to reduce the mortality and/or morbidity of the target disease. To achieve this goal, the basic aspects of the Program should be fulfilled. Proper Guidelines, high screening uptake rate, high quality, appropriate follow-up program were discussed. And national screening programs are not so commonly provided internationally. Only Japan provide national health screening program and Japanese program was renovated in 2008. The aim, contents and the procedure of the Japanese program was reviewed. Finally, the aspects that should be discussed for the improvement of the national health screening program was listed.
김정만,조규상,정치경,이원철 가톨릭대학산업의학센타 산업의학연구소 1981 韓國의 産業醫學 Vol.20 No.2
An epidemiological study of byssinosis was carried out by the standard questionnaire in a group of 343 women employed in carding and spinning room, and acute changes of ventilatory function during work shift were measured on Monday in 121 of 343 carders and spinners in a textile mill. Symptoms of byssinosis were found in 13.4% of 67 carders, in 11.6% of 276 spinners. Symptoms of byssinosis had no relation to duration of cotton dust exposure. In 121 carders and spinners forced expiratory volume in 1 second (FEV??) decreased significantly during work on Monday. There were no significant differences of these changes between workers with and without history of byssinosis, and the duration of dust exposure did not affect the decrease of FEV?? on Monday. FEV?? decreased 4.5% during work on Monday whereas maximal mid-expiratory flow (MMF) and maximal expiratory flow at 50% of forced vital capacity(V??) on maximal expiratory flow-volume (MEFV) curve decreased 7.0% and 10.1%. MMF and V?? were more sensitive indices than FEV?? in the detection of acute ventilatory changes caused by cotton dust. The average concentrations of respirable cotton dust (lint-free dust, fibers≤15μin length), measured with vertical elutriator, were 0.220mg/m³in carding room and 0.167mg/m³in spinning room.