• Title/Summary/Keyword: Forward selection

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

  • Park, Jog-Ku;Kim, Hun-Joo;Park, Keum-Soo;Lee, Sung-Su;Chang, Sei-Jin;Shin, Kye-Chul;Kwon, Sang-Ok;Ko, Sang-Baek;Lee, Eun-Kyoung
    • Journal of Preventive Medicine and Public Health
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    • v.29 no.3 s.54
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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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    • v.21 no.1
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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.

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

  • Park, Jong-Hoon;Back, Jin-Ho
    • Korean Journal of Applied Biomechanics
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    • v.15 no.3
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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.

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

  • Lee, Han Na;Kim, Gihong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.36 no.6
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    • pp.507-514
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    • 2018
  • TSI (TPI-Slope Index) which is the combination of TPI (Topographic Position Index) and slope was newly proposed for landslide and applied to a landslide susceptibility model. To do this, we first compared the TPIs with various scale factors and found that TPI350 was the best fit for the study area. TPI350 was combined with slope to create TSI. TSI was evaluated using logistic regression. The evaluation showed that TSI can be used as a landslide factor. Then a logistic regression model was developed to assess the landslide susceptibility by adding other topographic factors, geological factors, and forestial factors. For this, landslide-related factors that can be extracted from DEM (Digital Elevation Model), soil map, and forest type map were collected. We checked these factors and excluded those that were highly correlated with other factors or not significant. After these processes, 8 factors of TSI, elevation, slope length, slope aspect, effective soil depth, tree age, tree density, and tree type were selected to be entered into the regression analysis as independent variables. Three models through three variable selection methods of forward selection, backward elimination, and enter method were built and evaluated. Selected variables in the three models were slightly different, but in common, effective soil depth, tree density, and TSI was most significant.

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

  • Park, Yu Sun;Lee, Jong Hyuk;Park, Han Woong;Lee, Sung Kwang
    • Analytical Science and Technology
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    • v.28 no.3
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    • pp.187-195
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    • 2015
  • The heat of sublimation (HOS) is an essential parameter used to resolve environmental problems in the transfer of organic contaminants to the atmosphere and to assess the risk of toxic chemicals. The experimental measurement of the heat of sublimation is time-consuming, expensive, and complicated. In this study, quantitative structural property relationships (QSPR) were used to develop a simple and predictive model for measuring the heat of sublimation of organic compounds. The population-based forward selection method was applied to select an informative subset of descriptors of learning algorithms, such as by using multiple linear regression (MLR) and the support vector machine (SVM) method. Each individual model and consensus model was evaluated by internal validation using the bootstrap method and y-randomization. The predictions of the performance of the external test set were improved by considering their applicability to the domain. Based on the results of the MLR model, we showed that the heat of sublimation was related to dispersion, H-bond, electrostatic forces, and the dipole-dipole interaction between inter-molecules.

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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    • v.23 no.2
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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.

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

  • Sin, Dae Chul;Song, Ho Sueb
    • Journal of Acupuncture Research
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    • v.33 no.2
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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.

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

  • Song, Young-Wook;Kim, Beom-Ki
    • Journal of The Korean Association For Science Education
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    • v.30 no.4
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    • pp.375-388
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    • 2010
  • The purpose of this study was to develop the instrument for scientific attitudes in school, home and social situations and select the important elements of scientific attitudes. Looking into the elements of scientific attitudes in national and international research, the important elements of scientific attitudes students should have were selected as follows: Openness, objectivity, continuousness, criticalness, prudence, volunteerism, honesty, preparedness, collaboration, and curiosity. To develop the valid instrument of scientific attitudes, we moved forward with the step of making preliminary questions, the judgment step, and the validation examination step. Based on the elements of scientific attitudes and school, family, and social situations, the instrument of the scientific attitudes was developed. We discovered that Middle school students' scientific attitudes, according to their grade levels, appear to be significantly lower than those in the 7th graders and 9th graders. The scientific attitudes in school, home and social situation appeared high in order of society, home, and school. It appeared that there were no differences by gender.

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

  • 송승호
    • The Transactions of the Korean Institute of Power Electronics
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    • v.7 no.4
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    • pp.332-338
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    • 2002
  • High current coil power supply for superconductivity coil of tokamak requires fast dynamics performance of di/dt and smooth change over of current direction. To meet the specification high performance DSP-based controller Is designed for 12-pulse thyristor dual converter with interphase transformer(IPT). Not only the total current of Y and $\Delta$ converter units but also the difference for those should be regulated fast and accurately. Proportional and integral controller is designed for current difference control and the controller output is compensated to $\Delta$ converter. The source voltage phase angle detection and gate pulse generation algorithm are implemented in software for higher reliability of current control. The current error Is reduced by selection of appropriate initial gating angle during the transient of change over of current direction between thyristor converters.

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

  • Kim, Tae-Wook;Kong, Hyung-Yun
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.6
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    • pp.69-74
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    • 2014
  • In this paper, an energy harvesting scheme is investigated in the multi-relay cooperation communication. Our proposal is to maximize the diversity gain and overcome the disadvantages of the limited power wireless devices. The best relay is selected based on the maximizing channel gains from source to relays so that the harvested energy at selected relay is best. If an internal power of the best relay is lower than a defined target power, the best relay will harvest the energy from the source, and the help of the source-destination link is changed to the second best relay. By this operation method, the diversity gain is maintained and the performance of the network is improved. Finally, performance of the proposed protocol is analyzed in terms of bit error rate, utilization efficiency, power collection efficiency.