• 제목/요약/키워드: R, Model2

검색결과 5,386건 처리시간 0.035초

Effects of Lifestyle and Dietary Behavior on Cardiovascular Risks in Middle-aged Korean Men

  • Yim, Kyeong-Sook
    • Journal of Community Nutrition
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    • 제2권2호
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    • pp.119-128
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    • 2000
  • Lifestyle and dietary behavior intervention as the primary prevention of lipid disorder seems safe and compatible with other treatments of cardiovascular diseases. Cross-sectional associations between lifestyle factors and dietary behavioral factors with plasma lipid and lipoprotein levels were analyzed in 189 middle-aged men in Suwon, Korea. Overnight fasting plasma levels of total cholesterol, high-density lipoprotein(HDL)-cholesterol, triacylglycerol and glucose were analyzed. Blood pressure and anthropometric data were also measured. Lifestyle factors such as smoking status, alcohol consumption and frequency of physical exercise were evaluated by a self-administered questionnaire. Questions regarding dietary behavior were also asked. The subjects were 43.8%${\pm}$7.9 years old, and 23.8%${\pm}$2.6kg/m$^2$. From stepwise regression analyses, significant correlates with total cholesterol level were body mass index(BMI), alcohol intake(negative), age and coffee drinking(model R$^2$=14.3%). BMI, breakfast-skipping, age, and sleeping hours were significant for triacylglycerol level(model R$^2$=15.8%). BMI, alcohol drinking(negative), age, and coffee drinking were significant for low-density lipoprotein(LDL)(model R$^2$=11.7%). Age(negative), BMI(negative), alcohol drinking, stress level(negative), physical exercise, and cigarette smoking(negative) were significant for high-density lipoprotein(HDL)(model R$^2$=12.1%). From stepwise regression analyses, excluding BMI and age as factors in the model, alcohol intake(negative) and coffee drinking were significantly correlated with total cholesterol level(model R$^2$=4.4%) : breakfast-skipping with triacylglycerol(model R$^2$=3.2%) : alcohol intake (negative) with LDL level(model R$^2$=3.4%) : alcohol intake, physical exercise and stress level(negative) with HDL level(model R$^2$=6.3%). The findings suggest that a healthy daily lifestyle and dietary behavior may have an anti-atherogenic effect by altering plasma lipid and lipoprotein levels in middle-aged Korean men. (J Community Nutrition 2(2) : 119∼128, 2000)

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서비스 R&D 예산편성 및 투자전략 연구 (A Study on Service R&D Budgeting and Investment Strategy)

  • 김현수
    • 한국IT서비스학회지
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    • 제12권2호
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    • pp.373-386
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    • 2013
  • The purpose of this research is to develop a model for efficient service R&D investment in government budgeting process. It is necessary to develop an efficient and effective investment model to improve competitiveness of the service industry and national economy. Various existing types of service R&D classification have been reviewed. And object-oriented service R&D request classification types have been derived. A tentative model for evaluating service R&D requests have been developed through extensive discussions on effective methodologies. The model has been refined and revised by four service budgeting experts. The revised and refined checklists and guidelines have been used for 40 real service R&D requests evaluations. As a result, a full model for service R&D evaluation and budgeting has been proved to be useful. Also, a need for more efficient and concise evaluation model has been raised through this evaluation process. A brief model with only 10 checklists has been developed and its usefulness has been proven by pilot test with 10 real service R&D requests. The results of this study can be used for evaluation of service R&D proposals and effective budgeting of R&D requests for improving global competitiveness. Further research is needed for refining the developed evaluation models.

Associations of Single Nucleotide Polymorphisms in miR-146a, miR-196a, miR-149 and miR-499 with Colorectal Cancer Susceptibility

  • Du, Wei;Ma, Xue-Lei;Zhao, Chong;Liu, Tao;Du, Yu-Liang;Kong, Wei-Qi;Wei, Ben-Ling;Yu, Jia-Yun;Li, Yan-Yan;Huang, Jing-Wen;Li, Zi-Kang;Liu, Lei
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권2호
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    • pp.1047-1055
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    • 2014
  • Background: MicroRNAs (miRNAs) are an abundant class of endogenous small non-coding RNAs of 20-25 nucleotides in length that function as negative gene regulators. MiRNAs play roles in most biological processes, as well as diverse human diseases including cancer. Recently, many studies investigated the association between SNPs in miR-146a rs2910164, miR-196a2 rs11614913, miR-149 rs229283, miR-499 rs3746444 and colorectal cancer (CRC), which results have been inconclusive. Methodology/Principal Findings: PubMed, EMBASE, CNKI databases were searched with the last search updated on November 5, 2013. For miR-196a2 rs11614913, a significantly decreased risk of CRC development was observed under three genetic models (dominant model: OR = 0.848, 95%CI: 0.735-0.979, P = 0.025; recessive model: OR = 0.838, 95%CI: 0.721-0.974, P = 0.021; homozygous model: OR = 0.754, 95%CI: 0.627-0.907, P = 0.003). In the subgroup analyses, miR-$196a2^*T$ variant was associated with a significantly decreased susceptibility of CRC (allele model: OR = 0.839, 95%CI: 0.749-0.940, P = 0.000; dominant model: OR = 0.770, 95%CI: 0.653-0.980, P = 0.002; recessive model: OR = 0.802, 95%CI: 0.685-0.939, P = 0.006; homozygous model: OR = 0.695, 95%CI: 0.570-0.847, P = 0.000). As for miR-149 rs2292832, the two genetic models (recessive model: OR = 1.199, 95% CI 1.028-1.398, P = 0.021; heterozygous model: OR = 1.226, 95% CI 1.039-1.447, P = 0.013) demonstrated increased susceptibility to CRC. On subgroup analysis, significantly increased susceptibility of CRC was found in the genetic models (recessive model: OR = 1.180, 95% CI 1.008-1.382, P = 0.040; heterozygous model: OR = 1.202, 95% CI 1.013-1.425, P = 0.013) in the Asian group. Conclusions: These findings supported that the miR-196a2 rs11614913 and miR-149 rs2292832 polymorphisms may contribute to susceptibility to CRC.

Note on Use of $R^2$ for No-intercept Model

  • Do, Jong-Doo;Kim, Tae-Yoon
    • Journal of the Korean Data and Information Science Society
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    • 제17권2호
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    • pp.661-668
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    • 2006
  • There have been some controversies on the use of the coefficient of determination for linear no-intercept model. One definition of the coefficient of determination, $R^2={\sum}\;{\widehat{y^2}}\;/\;{\sum}\;y^2$, is being widely accepted only for linear no-intercept models though Kvalseth (1985) demonstrated some possible pitfalls in using such $R^2$. Main objective of this note is to report that $R^2$ is not a desirable measure of fit for the no-intercept linear model. In fact it is found that mean square error(MSE) could replace $R^2$ efficiently in most cases where selection of no-intercept model is at issue.

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궤도상을 이동하는 커서 이동시간의 예측 모델 (A Time Prediction Model of Cursor Movement with Path Constraints)

  • 홍승권;김성일
    • 대한산업공학회지
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    • 제31권4호
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    • pp.334-340
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    • 2005
  • A mouse is an important input device that is used in most of all computer works. A mouse control time prediction model was proposed in this study. Especially, the model described the time of mouse control that made a cursor to move within path constraints. The model was developed by a laboratory experiment. Cursor movement times were measured in 36 task conditions; 3 levels of path length, 3 levels of path width and 4 levels of target's width. 12 subjects participated in all conditions. The time of cursor movement with path constraints could be better explained by the combination of Fitts' law with steering law($r^2=0.947$) than by the other models; Fitts' law($r^2=0.740$), Steering law($r^2=0.633$) and Crossman's model($r^2=0.897$). The proposed model is expected to be used in menu design or computer game design.

World Class SI 기업으로의 도약 : 핵심 경쟁력 확보를 위한 R&D 모델 개발 (A R&D Model for Korean SI Companies' International Competitiveness)

  • 이연희;최진영
    • 한국IT서비스학회지
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    • 제2권2호
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    • pp.15-29
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    • 2003
  • This thesis suggests a R&D model for Korean SI companies who aggressively drive oversea business to overcome domestic market limitation and to become world class SI players. Even though there have been a lot of discussions on IT technologies and new business models, scientific approach to a R&D model for SI companies is rare due to its natural distinctiveness from manufacturing and general service domain. Therefore, this will be a flagship thesis to keep up our study. As business market environment gets more competitive, major Korean SI players will be confronted with much more keen competition among themselves. And as they are willing to expand their oversea market presence, they can not help struggling against global SI players. So, here we are presenting SI players the reinforcement of R&D as one of the key components to build up their own core competencies. That is, SI players have to adopt and evaluate fast changing and complicated IT technologies at the right time, and to apply them into a real business with cost-effective service delivery and operation processes internally. The ultimate purpose of all of these activities is to offer a SI company the value added business model based on its innovative technical capabilities and well refined service deliver model. For this purpose, we suggests, SI company's R&D has to play an important role of emerging technology verification/evaluation/utilization, value added business model creation, future innovation lead, standard body participation, and effective service delivery and quality system development. To become a more effective R&D organization, hybrid R&D, in which central R&D and divisional sub R&D work together, is considered as an idea model. The reliability of the R&D model for Korean SI companies', here we suggest, has been checked by SI companies R&D specialists and on-site business people.

아말감 와동의 파절에 관한 3차원 유한요소법적 연구 (A STUDY ON AMALGAM CAVITY FRACTURE WITH THREE DIMENSIONAL FINITE ELEMENT METHOD)

  • 김한욱;엄정문;이정식
    • Restorative Dentistry and Endodontics
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    • 제19권2호
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    • pp.345-371
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    • 1994
  • Restorative procedures can lead to weakening tooth due to reduction and alteraton of tooth structure. It is essential to prevent fractures to conserve tooth. Among the several parameters in cavity designs, cavity isthmus and depth are very important. In this study, MO amalgam cavity was prepared on maxillary first premolar. Three dimensional. finite element models were made by serial photographic method and cavity depth(1.7mm, 2.4mm) and isthmus (11 4, 1/3, 1/2 of intercuspal distance) were varied. linear, eight and six-nodal, isoparametric brick elements were used for the three dimensional finite element model. The periodontal ligament and alveolar bone surrounding the tooth were excluded in these models. Three types model(B, G and R model) were developed. B model was assumed perfect bonding between the restoration and cavity wall. Both compressive and tensile forces were distributed directly to the adjacent regions. G model(Gap Distance: 0.000001mm) was assumed the possibility of play at the interface simulated the lack of real bonding between the amalgam and cavity wall (enamel and dentin). When compression occurred along the interface, the forces were transferred to the adjacent regions. However, tensile forces perpendicular to the interface were excluded. R model was assumed non-connection between the restoration and cavity wall. No force was transferred to the adjacent regions. A load of 500N was applied vertically at the first node from the lingual slope of the buccal cusp tip. This study analysed the displacement, von Mises stress, 1 and 2 direction normal stress and strain with FEM software ABAQUS Version 5.2 and hardware IRIS 4D/310 VGX Work-station. The results were as follows: 1. G model showed stress and strain patterns between Band R model. 2. B model and G model showed the bending phenomenon in the displacement. 3. R model showed the greatest amount of the displacement of the buccal cusp followed by G and B model in descending order. G model showed the greatest amount of the displacement of the lingual cusp followed by B and R model in descending order. 4. B model showed no change of the displacement as increasing depth and width of the cavity. G and R model showed greater displacement of the buccal cusp as increasing depth and width of the cavity, but no change in the displacement of the lingual cusp. 5. As increasing of the width of the cavity, stress and strain were not changed in B model. Stress and strain were increased on the distal marginal ridge and buccopulpal line angle in G and R model. The possibility of the tooth fracture was increased. 6. As increasing of the depth of the cavity, stress and strain were not changed in B and G model. Stress and strain were increased on the distal marginal ridge and buccopulpal line angle in R model. The possibility of the tooth fracture was increased.

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극단 손실값들을 이용한 VaR의 추정과 사후검정: 사례분석 (Estimation of VaR Using Extreme Losses, and Back-Testing: Case Study)

  • 서성효;김성곤
    • 응용통계연구
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    • 제23권2호
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    • pp.219-234
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    • 2010
  • 시가총액에 따른 인덱스(INDEX) 투자를 했을 경우에, VaR(Value at Risk)을 종합주가지수(KOSPI)로부터 얻은 수익율의 극단 손실값들로부터 추정한다. 이를 위해, 극단값 이론 중 BM(Block Maxima) 모형을 적용하며, 극단 손실값들의 비독립적 발생을 고려하기 위하여, extremal index 역시 추정한다. 모형의 타당성을 알아보기 위해, 실패율방법을 이용한 사후검정 (back-testing) 을 실시한다. 사후검정을 통해, BM 모형을 적용한 VaR의 추정이 적절함을 알 수 있었다. 또한, 일반적으로 많이 사용되는 GARCH 모형을 이용한 VaR의 추정과 비교한다. 이를 통해, 오차가 t-분포를 따른다고 가정하는 경우, GARCH 모형을 이용한 VaR의 추정이 BM 모형을 이용한 경우와 사후 검정결과에 차이가 없음을 확인하였다. 그러나, GARCH 모형을 통한 VaR 추정은 추정시점근방의 극단 손실값들에 민감하게 반응하지만, BM 모형은 그렇지 않았다. 따라서, 현 시점으로부터 단기간동안의 손실위험은 GARCH 모형을 이용한 VaR의 추정값을 사용하는 것이 적절하며, 장기간동안의 손실위험은 BM 모형으로부터 얻은 VaR의 추정값을 사용하는 것이 적절하다.

사회문제 해결형 R&D 모델의 진화 과정 분석과 과제 (A Study on the Evolution of 'Social problem-solving R&D model' in Korea)

  • 성지은;송위진
    • 기술혁신연구
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    • 제31권2호
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    • pp.83-110
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    • 2023
  • 이 연구는 정부의 사회문제 해결형 연구개발사업 진화과정을 통해 사회문제 해결형 R&D 모델이 한국 사회에 자리 잡는 과정을 분석한다. 기업, 과학기술계, 시민사회에도 없었던 사회문제 해결형 R&D 모델이 정부연구개발사업을 통해 형성되고 이 모델에 따라 혁신활동을 수행하는 조직공동체가 전개되는 과정을 살펴볼 것이다. 이를 위해 새로운 혁신모델인 사회문제 해결형 R&D 모델, 그것을 지원·수행하는 조직공동체, 새 모델을 지원하는 제도가 공진화하는 과정을 분석하는 개념적 틀을 제시한다. 그리고 이 틀을 기반으로 사회문제 해결형 연구개발사업이 진행되면서 새로운 혁신모델이 형성·발전되는 과정을 살펴보고 그 의미를 논의할 것이다. 종합에서는 사회문제 해결형 R&D 모델의 활성화를 위한 과제와 정책 방안을 다룬다.

Re-timing 기능을 생략한 광/전/광 파장변환기의 cascadability 분석 및 측정 (Analysis and measurement of the cascadability for 2R O/E/O wavelength converter)

  • 장윤선;김광준
    • 한국광학회지
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    • 제14권3호
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    • pp.215-218
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    • 2003
  • 2R 광/전/광 파장변환기는 이미 검증된 기술을 사용하여 간단히 구현할 수 있으며 데이터 전송율을 제한하지 않는다는 장점이 있다. 그러나, 이 방식은 각 파장변환기를 통과하면서 타이밍 지터 성분이 계속 누적되어 cascadability가 제한된다 본 논문에서는 통상적인 정현파 신호 모델 대신 보다 현실적인 비선형 신호 모델을 제안하여 시스템 성능에 미치는 타이밍 지터의 영향 및 2R 광/전/광 파장변환기의 cascadability를 이론적으로 분석하였으며, 40-km re-circulation loop 실험 장치에서 10 Gb/s 신호에 대한 cascadability를 측정하여 계산 결과와 비교하였다.