• 제목/요약/키워드: Independent Park

검색결과 3,501건 처리시간 0.036초

A Technique to Improve the Fit of Linear Regression Models for Successive Sets of Data

  • Park, Sung H.
    • Journal of the Korean Statistical Society
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    • 제5권1호
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    • pp.19-28
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    • 1976
  • In empirical study for fitting a multiple linear regression model for successive cross-sections data observed on the same set of independent variables over several time periods, one often faces the problem of poor $R^2$, the multiple coefficient of determination, which provides a standard measure of how good a specified regression line fits the sample data.

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Demographic and lifestyle factors and selenium levels in men and women in the U.S.

  • Park, Kyong;Rimm, Eric;Siscovick, David;Spiegelman, Donna;Morris, J. Steven;Mozaffarian, Dariush
    • Nutrition Research and Practice
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    • 제5권4호
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    • pp.357-364
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    • 2011
  • Selenium is an antioxidant trace element linked to cardiovascular disease and cancer. Although diet is a major source, relatively little else is known about independent determinants of selenium levels in free-living humans. In this study, we aimed to investigate the independent demographic. lifestyle, and dietary determinants of selenium levels in 1,997 men and 1,905 women in two large prospective U.S. cohorts. Toenail selenium levels were quantified using neutron activation analysis. Diet, geographic residence, demographic, and environmental factors were assessed by validated self-administered questionnaires. Multivariate generalized linear models were conducted to assess the independent relations of these factors with toenail selenium levels, correcting for measurement error in the diet. In multi variable-adjusted analyses, independent predictors of higher selenium were male gender (6.3% higher levels); living in West and Northern-Midwest U.S. regions (8.9% and 7.4% higher than Southern-Midwest regions, respectively); consumption of beef and bread products (between 0.7 - 2.5% higher per daily serving); and selenium supplement use (6.9% higher than non-users); whereas cigarette smoking (5-10% lower than never smokers), older age (0.6% lower per 5 years), and consumption of eggs, white rice, dairy products, coffee, and alcohol (between 0.1 to 2.0% lower per daily serving) were associated with lower selenium. Multiple dietary and non-dietary factors independently predicted selenium levels, suggesting that both consumption and non-dietary processes (e.g.. related to oxidant status) may affect levels. Significant geographic variation in selenium levels exists in the US.

Excel의 추세선을 이용한 표준곡선 검증 (Standard Curve Validation using Trendlines in Excel)

  • 이경화;박형기;신영만
    • 핵의학기술
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    • 제20권2호
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    • pp.69-74
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    • 2016
  • Insulin 83건을 검사 대상으로, 장비 WIZARD(PerkinElmer, USA)와 DREAM- G-10(Shinjin, KOREA)의 Graph Algorithm 중에 표준곡선과 신뢰성이 가장 높은 Excel의 추세선은 다항식 추세선이다. 다음으로 다항식 추세선식을 이용하여 표준농도 1개씩을 제외하여 표준농도의 회귀식에 미치는 영향을 비교한 결과 최고농도($315{\mu}IU/m{\ell}$)의 평균값이 표준물질 6개로 실시한 표준 회귀식을 이용한 평균값과 비교하여 49%나 평균값이 저하되었다. 단 낮은 농도에서는 영향이 미비하였다. 마지막으로 WIZARD의 Point to Point형식과 DREAM G-10의 Point to Point형식이 적합성이 높고, DREAM G-10(Point to Point)와 Excel 다항식 추세선이 적합성이 높으며, Excel 다항식 추세선과 DREAM G-10(2'nd order Polynomial)의 적합성이 높다.

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빌딩간 연결을 통한 복합제어시스템의 최적설계 (Optimal Design of Hybrid Control System through Inter-Building Connection)

  • 박관순;옥승용
    • 한국안전학회지
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    • 제32권6호
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    • pp.81-88
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    • 2017
  • This study deals with the optimal design of a hybrid control system composed of a combination of active control system and passive control system for effective seismic performance improvement of two adjacent structures. The proposed hybrid control system adopts a configuration of installing an active control device in one building and connecting two adjacent structures with a passive control device so that the one-side active control force can be bi-directionally applied to both buildings through the passive connecting devices. In order to derive the optimal performance of the proposed system, the design parameters of the passive and active control systems were searched using the genetic algorithm. Numerical simulations of 10-story and 8-story buildings have been performed to verify the effectiveness of the proposed technique. For the purpose of comparison, the conventional independent control system with two identical active control systems being installed separately for each structure was also optimally designed and its seismic response has been evaluated as well. From the comparative results of the two control systems, it is demonstrated that the proposed hybrid control system requires larger control force for its one-side active control device than the conventional independent control system does for each of both-side active devices, but quite less than the total control force required for both-side devices of the independent control system, while maintaining similar seismic performance. Therefore, the proposed system is more economical and reliable than the conventional independent control system with two identical active devices.

무릎관절 골관절염 환자의 보행기 보행에서 생역학적 특성 (Biomechanical Properties of the Anterior Walker Dependent Gait of Patients with Knee Osteoarthritis)

  • 이인희;권기홍;박상영
    • The Journal of Korean Physical Therapy
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    • 제25권5호
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    • pp.239-245
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    • 2013
  • Purpose: Osteoarthritis occurs in many different joints of the body, causing pain, stiffness, and decreased function. The knee is the most frequently affected joint of the lower limb. The aim of this study was to investigate the differences of biomechanics between independent gait and anterior walker dependent gait of patients with osteoarthritis of the knee. Methods: Lower limb joint kinematics and kinetics were evaluated in 15 patients with knee osteoarthritis when walking independently and when walking with an anterior walker. Participants were evaluated in a gait laboratory, with self-selected gait speed and natural arm swing. Results: When walking with a dependent anterior walker, participants walked significantly faster (p<0.01), using a longer stride length (p<0.01), compared to independent gait. When walking with a dependent anterior walker, participants exhibited significantly greater knee flexion/extension motion (p<0.01) and lower knee flexion moment (p<0.05) compared to independent gait. When walking with a dependent anterior walker, participants showed significantly greater peak ankle motion (p<0.01), ankle dorsiflexion/plantarflexion moments (p<0.01), and ankle power generation (p<0.05) compared to independent gait. Conclusion: These biomechanical properties of gait, observed when participants walked with a dependent anterior walker, may be a compensatory response to impaired knee function to allow sufficient power generation for propulsion. Therefore, rehabilitative strategies for patients with osteoarthritis of the knee are needed in order to improve not only knee function but also hip and ankle function.

Spatiotemporal Analysis of Hippocampal Long Term Potentiation Using Independent Component Analysis

  • Kim, T.S.;Lee, J.J.;Hwang, S.J.;Lee, Y.K.;Park, J.H.
    • 대한의용생체공학회:의공학회지
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    • 제28권1호
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    • pp.17-23
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    • 2007
  • Long-term potentiation (LTP) of synaptic transmission is the most widely studied model for learning and memory. However its mechanisms are not clearly elucidated and are a subject for intense investigation. Previous attempts to decipher cellular mechanisms and network properties involved a current-source density analysis (CSDA) of the LTP from small animal hippocampus measured with a limited number of microelectrodes (typically <3), only revealing limited nature of spatiotemporal dynamics. Recent advancement in multi-electrode array (MEA) technology allows continuous and simultaneous recordings of LTP with more than 60 electrodes. However CSDA via the standard Laplacian transform is still limited due to its relatively high sensitivity toward noise, inability of resolving overlapped current sources and sinks, and its requirement for tissue conductivity values. In this study, we propose a new methodology for improved CSDA. Independent component analysis and its joint use (i.e., Joint-ICA) are applied to extract spatiotemporal components of LTP. The results show that ICA and Joint-ICA are capable of extracting independent spatiotemporal components of LTP generators. The ICs of LTP indicate the reversing roles of current sources and sinks which are associated with LTP.

노인의 독립적 삶의 기대감이 세대 간 자원 하향이전에 미치는 영향 연구 (The Study on the Impact of the Expectation of Independent Life in Old Age on Intergenerational Downward Transfer of Korean Old People)

  • 강유경;박승희
    • 한국사회복지학
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    • 제63권2호
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    • pp.133-154
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    • 2011
  • 본 연구는 자녀와 동거하지 않는 65세 이상 노인을 대상으로 노년기 독립적인 삶의 기대감과 노인의 하향이전의 관계를 실증적으로 검토하여 분석하였다. 분석에 사용된 자료는 "2008년도 전국 노인생활실태 및 복지욕구조사"자료이며, 자료분석은 다중회귀분석을 이용하였다. 분석결과, 노인의 독립적인 삶의 기대감 정도는 노인의 하향이전 정도에 정적(+)인 영향을 주는 것으로 나타났으며, 구체적으로 경제적 신체적 독립적인 삶의 기대감은 노인의 경제적 서비스 하향이전에 정적(+)인 영향을 주는 것으로 나타난 반면, 심리적 독립적인 삶의 기대감은 노인의 서비스 하향이전에는 정적(+)인 영향을 주는 것으로 나타났지만 경제적 하향이전에는 영향을 주지 않는 것으로 나타났다.

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