• Title/Summary/Keyword: forward selection

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뇌혈관질환과 관상동맥성 심질환의 위험요인에 관한 환자-대조군 연구 (The Case-Control Study on the Risk Factors of Cerebrovascular Diseases and Coronary Heart Diseases)

  • 박종구;김헌주;박금수;이성수;장세진;신계철;권상옥;고상백;이은경
    • Journal of Preventive Medicine and Public Health
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    • 제29권3호
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    • pp.639-655
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    • 1996
  • Cerebrovascular disease and coronary heart disease are the first and the fourth common causes of death among adults in Korea. Reported risk factors of these diseases are mostly alike. But some risk factors of one of these diseases may prevent other diseases. Therefore, we tried to compare and discriminate the risk factors of these diseases. We recruited four case groups and four control groups among the inpatients who were admitted to Wonju Christian Hospital from March, 1994 to November, 1995. Four control groups were matched with each of four case groups by age and sex. The number of patients in each of four case and control groups were 106 and 168 for acute myocardial infarction(AMI), 84 and 133 for subarachnoid hemorrhage(SAH), 102 and 148 for intracerebral hemorrhage(ICH), and 91 and 182 for ischemic stroke(IS) respectively. Factors whose levels were significantly higher in AMI and IS than in responding control group (RCG) were education, economic status, and triglyceride. Factors whose levels were significantly lower in hemorrhagic stroke than in RCG were age of monarch, and prothrombin time. The factor whose level was higher in AMI than ill RCG was uric acid. The factor whose level was higher in AMI, ICH, and SAM than in RCG was blood sugar. Factors whose levels were significantly higher in all the case groups than in RCG were earlobe crease, Quetelet index, white blood cell count, hemoglobin, hematocrit, and total cholesterol. The list of risk factors were somewhat different among the four diseases, though none of the risk factors to the one disease except prothrombin time acted as a preventive factor to the other diseases. The percent of grouped cases correctly classified was higher in the discrimination of ischemic diseases(AMI and IS) from hemorrhagic diseases(SAM and ICH) than in the discrimination of cerebrovascular disease from AMI. The factors concerned in the discrimination of ischemic diseases from hemorrhagic diseases were prothrombin time, earlobe crease, gender, age, uric acid, education, albumin, hemoglobin, the history of taking steroid, total cholesterol, and hematocrit according to the selection order through forward selection.

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The Expression of Genes Related to Egg Production in the Liver of Taiwan Country Chickens

  • Ding, S.T.;Ko, Y.H.;Ou, B.R.;Wang, P.H.;Chen, C.L.;Huang, M.C.;Lee, Y.P.;Lin, E.C.;Chen, C.F.;Lin, H.W.;Cheng, Winston Teng Kuei
    • Asian-Australasian Journal of Animal Sciences
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    • 제21권1호
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    • pp.19-24
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    • 2008
  • The purpose of this study was to detect expression of genes related to egg production in Taiwan Country chickens by suppression subtractive hybridization. Liver samples of mRNA extraction from two Taiwan Country chicken strains (L2 and B), originated from the same population but with very distinct egg production rates after long-term selection for egg and meat production respectively. Two-way subtraction was performed. The hepatic cDNA from the low egg production chickens (B) was subtracted from the hepatic cDNA from the high egg production strain (L2). The reversed subtraction (L2 from B) was also performed. The resulting differentially expressed gene fragments were cloned and sequenced. We sequenced 288 clones from the forward subtraction and 96 clones from the reverse subtraction. These genes were subjected to further screening to confirm the differential expression between the two genetic breeds of chickens. The apolipoprotein B (apoB) was expressed to a greater extent in the liver of the L2 than in the B line chickens. The 5-aminoimidazole- 4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (PURH) was expressed to a greater extent in the liver of the B than in the L2 strain chickens. We demonstrated that both apoB and PURH were more highly expressed in the liver than that in other tissues (muscle, ovary, and oviduct) in laying Taiwan Country chickens. Taken together, these data suggest that after the selection for egg production, expression of apoB and PURH genes were also changed. Whether the changed expression of these genes is directly related to egg production is not known, but these two genes may be useful markers for egg laying performance in Taiwan Country chickens.

평행봉 Tichonkich 동작의 운동학적 분석 (Kinematical Analysis of Tichonkich Motion in Parallel Bars)

  • 박종훈;백진호
    • 한국운동역학회지
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    • 제15권3호
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    • pp.21-30
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    • 2005
  • The purpose of this study is helps to make full use for perfect performance by grasping the defects of Tichonkich motion performed by athlete CSM For this, the study analyzed kinematical variables through Tichonkich motions performed at the first selection competition(1st trial) and final selection competition(2nd trial) for the dispatch to the 28th Athens Olympic Games using the three-dimensional cinematographical method with a high-speed video camera, and obtained the following results. 1. During Tichonkich motion, the execution time of up swing and the right hand moving to the left bar was shorter in the 2nd trial than the 1st one, while the execution time of down swing, the support of the left bar and the right hand moving to the right bar was longer in the 2nd trial than the 1st trial. 2. The horizontal position of COG in the 2nd trial was -35cm in the 1st stage, 42cm in the 3rd stage and 29cm in the 4th stage, that is, it showed a great swing focused on the circular movement compared to the 1st trial, while the vertical position of COG was -59cm in the 2nd stage, that is, it showed a small swing focused on a up and down movement. Also the 5th stage vertical position was 98cm, and the 6th stage vertical position was 95cm in the 2nd trial which were higher than those of the 1st trial, so it has provided magnificence required in the modern gymnastics. 3. And it was indicated that the horizontal velocity at the down swing phase proceeded forward more rapidly in the 2nd trial than that in the 1st trial, and the reverse ascent made a rapid vertical rise lessening left and right velocity change. And in the 5th stage, the 2nd trial was kept very slower in horizontal, vertical and left and right velocity that in the 1st trial, so it reached a handstand with leisurely movement. 4. In the 2nd trial, shoulder joint of the 1st, 2nd, 3rd stages kept a larger angle than that in the 1st trial, that is, it made a great swing while in the 1st trial, it showed a swing movement dependent on kick movement by the flexion and extension of hip joint. Also in the 2nd trial, the body formed a vertical posture with both hands supporting the left bar and hip joint was kept larger as $198^{\circ}$ and $190^{\circ}$ in the 5th and 6th stage than that in the 1st trial, so it made a handstand with the body uprightly stretched out, and magnificent and stable movement.

TPI와 경사도 조합을 이용한 산사태 위험도 평가 (Landslide Susceptibility Assessment Using TPI-Slope Combination)

  • 이한나;김기홍
    • 한국측량학회지
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    • 제36권6호
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    • pp.507-514
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    • 2018
  • TPI (Topographic Position Index)와 경사도를 조합하여 새로운 산사태 인자인 TSI (TPI-Slope Index)를 제안하고 산사태 예측모형에 적용하였다. 이를 위해, 먼저 다양한 분석 반경의 TPI를 서로 비교하여 TPI350이 연구 대상 지역에 가장 적합함을 알아내었고, 이를 경사도와 조합하여 TSI를 제작하였다. 본 논문에서 제안한 TSI의 적용성을 평가하기 위해 로지스틱 회귀분석을 이용한 결과, 산사태 예측 모형에 활용할 수 있다는 결론을 얻었다. 그 후, 기타 지형 정보들과 토양 및 임상 정보를 추가하여 산사태 위험도를 평가하는 로지스틱 회귀 모형을 제작하였다. 이를 위해 DEM (Digital Elevation Model), 토양도, 임상도로부터 추출할 수 있는 산사태 관련 인자들을 수집하고 이들을 검토하여 다른 인자와 상관도가 높거나 산사태와의 연관성이 낮은 인자들은 우선 제외하였다. 그 결과, TSI, 고도, 사면 길이, 경사향, 유효 토심, 영급, 나무 밀도, 임상 등 8개의 인자가 선정되어 회귀분석에 독립변수로 입력되었다. 변수의 입력 방법(전진 선택법, 후진 제거법, 직접 선택법)에 따라 3가지 모형을 생성하였고, 이들에 대한 평가를 수행하였다. 세 모형에서 선택된 변수는 조금씩 다르지만, 공통적으로 유효 토심, 나무 밀도, TSI 인자의 중요도가 높은 것으로 나타났다.

유기화합물의 승화열 예측을 위한 QSPR분석 (QSPR analysis for predicting heat of sublimation of organic compounds)

  • 박유선;이종혁;박한웅;이성광
    • 분석과학
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    • 제28권3호
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    • pp.187-195
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    • 2015
  • 승화열은 대기 유기 오염물질의 확산에 관련된 환경적인 문제를 해결하거나, 위험한 화학 물질의 위해성을 평가하는 데에 중요한 변수이다. 하지만 실험적으로 승화열을 측정하려면 많은 시간과 비용이 소모 되며, 그 실험자체도 복잡하고 위험하다. 따라서 본 연구에서는 유기화합물의 승화열을 간단하게 예측하는 모델을 개발하기 위하여 정량적 구조-물성 상관관계 연구를 이용하였다. 군기반 전진선택방법을 적용하여 다중선형회귀방법과 서포트 벡터 머신과 같은 학습방법에 적합한 분자표현자들을 선택하도록 하였다. 개별 모델과 복합모델들은 부스트래핑 방법과 y-임의추출법에 의해 내부검증이 되었다. 외부 테스트 데이터의 예측 성능은 적용범위를 고려하므로서 개선되었다. 다중선형회귀모델에 따르면, 승화열은 분자간의 분산력, 수소결합, 정전기적 상호작용, 쌍극자-쌍극자 상호작용과 관련이 있는 것을 나타낼 수 있었다.

Research on the support of larger broken gateway based on the combined arch theory

  • Yang, Hongyun;Liu, Yanbao;Li, Yong;Pan, Ruikai;Wang, Hui;Luo, Feng;Wang, Haiyang;Cao, Shugang
    • Geomechanics and Engineering
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    • 제23권2호
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    • pp.93-102
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    • 2020
  • The excavation broken zones (EBZ) of gateways is a significant factor in determining the stability of man-made opening. The EBZ of 55 gateways with variety geological conditions were measured using Ground Penetrating Radar (GPR). The results found that the greatly depth of EBZ, the smallest is 1.5 m and the deepest is 3.5 m. Experimental investigations were carried out in the laboratory and in the coal mine fields for applying the combined arch support theory to large EBZ. The studies found that resin bolts with high tensile strength and good bond force could provide high pretension force with bolt extensible anchorage method in the field. Furthermore, the recently invented torque amplifier could greatly improve the bolt pretension force in poor lithology. The FLAC3D numerical simulation found that the main diffusion sphere of pretension force was only in the free segment zone of the surrounding rock. Further analysis found that the initial load-bearing zone thickness of the combined arch structure in large EBZ could be expressed by the free segment length of bolt. The using of high mechanical property bolts and steel with high pretension force will clearly putting forward the bolt length selection rule based on the combined arch support theory.

침구와 약침에 대한 중개연구 현황 (Current situation of Translational research on Acupuncture, Moxibustion and Pharmacopuncture)

  • 신대철;송호섭
    • Journal of Acupuncture Research
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    • 제33권2호
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    • pp.109-116
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    • 2016
  • Objectives : Our primary objective lies in understanding the current landscape of translational research on acupuncture, moxibustion and pharmacopuncture. Methods : We searched our own selection of keywords of acupuncture, moxibustion and pharmacopuncture and translational research from three overseas databases (Pubmed, Scopus, Medicine) and four domestic databases (DBpia, KISS, Riss4u, Korea Med). Results : We have chosen 41 articles in total-40 articles on acupunture, 6 article on moxibustion(5 articles were duplicated in use in each category). Origin-wise, 48.8 %/24.8 %/17.0 % of our articles pool came from USA/China/Korea, respectively. UK, Austria, Thailand and Italy contributed the rest of our article pool. For those articles written in USA and China, review articles were the most common type. For the US articles, all 10 review articles were non-systematic reviews, while, for China's contribution, one out of 4 review articles were systematic review. Type-wise, our research pool's breakdown is as follows ; 17 review articles, 11 experimental research, 2 randomized controlled trials(RCT), 1 clinical trial, 4 conference reports, 1 letter, 1 study protocol and 4 uncategorized. Topic-wise, brain-neurology was most frequently referred with 8 articles, followed by parkinson's disease (3 articles) and epilepsy (2 articles). Conclusion : 1. In terms of research submission articles, Korea appears to be lacking translational research on acupuncture, moxibustion and pharmacopuncture, compared to USA and China, in our view. 2. Unlike the cases of USA and China, most of Korean translational research is limited to doing a T1 level of translational research. In order to bring bench-to-bedside to light. we believe, there should be more studies, and thereby a certain level of activation, to the T2 level of translational research in Korea. 3. Further, in our view there should be more efforts to improve article quality at the T1 level of translational research, which eventually becomes the fundamentals of the next level of research (i.e. T2 research), as well as to increase the number of research submissions, going forward.

과학적 태도 요소 선정 및 학교, 가정, 사회 상황을 고려한 과학적 태도 측정 도구 개발 (The Development of an Instrument for Scientific Attitudes in School, Home and Social Situations and Selection of Scientific Attitude Elements)

  • 송영욱;김범기
    • 한국과학교육학회지
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    • 제30권4호
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    • pp.375-388
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    • 2010
  • 이 연구의 목적은 국내 외 연구의 과학적 태도 요소를 고찰하여 중요한 과학적 태도 요소를 선정하고, 학교 실험실 상황 및 사회, 가정 상황에서 과학적 태도를 묻는 문항을 개발하여, 중학생들의 학교, 가정, 사회 상황에 과학적 태도 차이가 있는지 알아보는 데 있다. 국내 외 연구의 과학적 태도 요소를 조사하여 학생들이 갖추어야 할 중요한 과학적 태도 요소로 개방성, 객관성, 계속성, 비판성, 신중성, 자진성, 정직성, 준비성, 협동성, 호기심을 선정하였다. 과학적 태도 측정 도구 개발의 타당성을 확보하기 위하여 '예비문항 제작 단계', '판단 단계', '타당도 검토 단계'로 진행하였고 선정한 과학적 태도 요소와 학교, 가정, 사회 상황을 고려한 과학적 태도 측정 도구를 개발하였다. 중학생들의 과학적 태도는 8학년이 7학년, 9학년에 비해 유의하게 낮고, 상황별 과학적 태도는 사회, 가정, 학교 상황으로 높고, 성별로 상황에 따른 차이는 없는 것으로 나타났다.

대전류 코일 전원 공급장치를 위한 12펄스 듀얼 컨버터의 전류제어 (Current Control of 12-pulse Dual Converter for High Current Coil Power Supply)

  • 송승호
    • 전력전자학회논문지
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    • 제7권4호
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    • pp.332-338
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    • 2002
  • 토카막 장치의 초전도 코일에 사용되는 전원 공급장치는 초대형급(20kA) 직류 전원 공급기로서 빠른 전류제어 응답성과 매우 작은 정상상태 리플이 필수적이다. 특히 역전류 공급이 가능한 회생형 컨버터의 운전중 전류 방향이 바뀌는 순간에도 전류기준값을 잘 추종하는 것이 중요하다. 이러한 조건들을 만족시키기 위하여 입력측에 2중 출력($\Delta$, Y)를 갖는 변압기와 출력단에 상간변압기(interphase transformer, IPT)를 이용한 12펄스 싸이리스터 듀얼 컨버터를 설계, 제작하였다. 각 컨버터에서 출력되는 전류의 합이 부하전류 지령치를 따르도록 제어하는 동시에 차 전류의 평균값이 영이 되도록 함으로써 각 컨버터의 부하 분담율을 일정하게 하여 상간 변압기의 포화를 방지한다. 대전류 코일 전류 공급장치의 양방향 전류 제어 성능을 높이기 위하여 위상각 검출 및 게이팅 지연각 구현을 디지털화하고 컨버터 전류방향 정역절환시 초기 응답특성을 개선하는 방법을 제안하였다. 또한 시뮬레이션과 실부하 전류실험을 통해 제안된 제어기의 동작성능을 확인하였다.

다중 중계기 환경에 대한 에너지 하베스팅의 적용 방안 (Applied Method of Energy Harvesting for Multi-Relay Environment)

  • 김태욱;공형윤
    • 한국인터넷방송통신학회논문지
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    • 제14권6호
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    • pp.69-74
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    • 2014
  • 본 논문에서는 협력 통신의 다중 중계기 모델에 에너지 하베스팅 기법을 적용하여 수신단에서 다이버시티 이득을 극대화함과 동시에 중계기의 전력 낭비를 줄일 수 있는 방안을 제안하였다. 송신단은 에너지 하베스팅 기법이 적용된 다중 중계기 중 가장 우수한 중계기를 선택해 메시지를 전송하게 되며 나머지 중계기는 전력으로 변환하여 저장하게 된다. 또한 기존에 선택된 중계기의 전력량이 일정 수준 이하일 경우 차선의 중계기를 선택해 전송을 유지함으로서 수신단의 다이버시티 이득을 유지할 수 있다. 따라서 제안하는 프로토콜을 일반적인 네트워크에 적용할 경우 중계기의 잔여 전력량에 따라 중계기의 교체가 지속적으로 이루어지게 되어 네트워크의 활용도 및 효율성을 증가시킬 수 있다. 마지막으로, 제안한 프로토콜을 레일리 페이딩 환경에서 전력 수집 효율 및 중계기 활용률, 비트 오류율(Bit Error Rate)을 통해 시스템의 성능을 평가한다.