모형명세화 오류와 소표본에서 구조방정식모형 모수추정 방법들 비교: 모수추정 정확도와 이론모형 검정력을 중심으로

서동기,정선호,Seo, Dong Gi,Jung, Sunho 한국데이터정보과학회 2017 한국데이터정보과학회지 Vol.28 No.5

구조방정식모형은 사회과학 및 행동과학 연구 분야에서 이론검정을 위해 주로 사용되는 통계방법이다. 최근 이 통계기법에 대한 방법론적 이슈로서 모형명세화 오류와 소표본 문제가 부각되고 있다. 그런데 이 문제들이 구조방정식모형의 대표 추정 방법인 최대우도법에 위한 이론검정에 어떤 영향을 주는지에 대해 여전히 명확하지 않다. 따라서 본 연구에서 최대우도법 그러고 이에 대한 대안으로 개발된 2단계최소자승법과 2단계능형최소자승법을 정확도와 검정력 관점에서 시뮬레이션을 통해 체계적으로 비교해 본다. 이 실험 결과에 따르면, 모형이 정확하게 설정된 경우, 정확도 기준에서 추정방법들 간의 차이는 미미했다. 하지만 모형오류가 발생한 경우, 2단계능형최소자승법은 다른 방법들보다 표본 크기가 작을 때 훨씬 더 정확한 모수추정치를 산출해 내었다. 그러고 이 방법은 명세화 오류에 관계없이 표본 크기가 작을 때에도 제 2종 오류 (Type II error) 수준이 상대적으로 작거나 만족할만한 수준의 검정력을 보여주었다. 이에 반해 다른 두 방법들은 표본이 작은 경우 또는 명세화 오류가 있는 경우 상당히 높은 수준의 제 2종 오류를 나타내었다. Structural equation modeling (SEM) is a basic tool for testing theories in a variety of disciplines. A maximum likelihood (ML) method for parameter estimation is by far the most widely used in SEM. Alternatively, two-stage least squares (2SLS) estimator has been proposed as a more robust procedure to address model misspecification. A regularized extension of 2SLS, two-stage ridge least squares (2SRLS) has recently been introduced as an alternative to ML to effectively handle the small-sample-size issue. However, it is unclear whether and when misspecification and small sample sizes may pose problems in theory testing with 2SLS, 2SRLS, and ML. The purpose of this article is to evaluate the three estimation methods in terms of inferences errors as well as parameter recovery under two experimental conditions. We find that: 1) when the model is misspecified, 2SRLS tends to recover parameters better than the other two estimation methods; 2) Regardless of specification errors, 2SRLS produces small or relatively acceptable Type II error rates for the small sample sizes.

경직형 뇌성마비아동의 마사지 프로그램 적용이 근력, 관절가동범위 및 일상생활활동에 미치는 효과

유인우,서동기,김수현,임준오,이정원,박기대,김진아,Yu, In-Woo,Seo, Dong-Gi,Kim, Soo-Hyun,Im, Jun-Oh,Lee, Jeong-Won,Bak, Ki-Dae,Kim, Jin-A 한국임상보건과학회 2016 한국임상보건과학회지 Vol.4 No.1

Purpose. The purpose of this study was to determine the effect of massage program on muscle strength (MMT), range of motion (ROM) and activities of daily living (ADL) in children with spastic cerebral palsy. Methods. The child welfare center of J city were measurement goniometer by range of motion and evaluation of activities of daily living scale and muscle strength scale. The massage program was applicated with 40 min, 2 times per a week and total 8 weeks. Massage program constituted surface of effleurage, petrisage, deep part of effleurage, friction in regular sequence. Result. For muscle strengths were significantly differenced after 8 weeks. For range of motion were dose dependent increased different two groups. And activities of daily living scale were significantly difference between massage group and non-massage group. Conclusion. In this study, the therapeutic massage program showed a positive effect for muscle strength, range of motion and activities of daily living in spastic cerebral palsy.

한국형 사이코패시: 국내 사이코패시 평가도구 타당화 연구를 바탕으로

강민성,서동기,서종한,Minseong Kang,Dong Gi Seo,Jonghan Sea 한국문화및사회문제심리학회 2024 한국심리학회지: 문화 및 사회문제 Vol.30 No.1

The purpose of this study is to conduct an exploratory investigation into Korean psychopathy by synthesizing the results of prior domestic research on the validation of psychopathy assessment tools. Domestic research on the validation of psychopathy scales has been constrained by limited research methodologies, bias toward male subjects, and the application of inappropriate factor structures. Furthermore, although discrepancies between the original scale and the Korean scale were identified regarding the factor structures through in construct validity research, discussion on the concept of Korean psychopathy has been limited. As a result, this study compared 16 domestic papers on the validation of psychopathy assessment tools along with 9 international foreign papers that addressed the factor structure of each original scale. By comparing the derived factor structures, items assigned to each factor, and omitted items from each study, the characteristics of Korean psychopathy were explored. The findings revealed that Korean psychopathy is recognizable from materialism, machiavellianism, and antisocial behavior and impulsivity. This study holds significance in synthesizing the outcomes of current domestic psychopathy validation research and offers a conceptual foundation to help understand Korean psychopathy.

컴퓨터 기반 맞춤형 검사의 구현을 위한 웹 기반 플랫폼(LIVECAT)의 정확성 및 효율성 검증

김도경(Do-Gyeong Kim),서동기(Dong-Gi Seo) 한국정보기술학회 2020 한국정보기술학회논문지 Vol.18 No.4

Recently, there has been an increase in the need for computerized adaptive testing(CAT), however its practical use is limited. In this study, we developed a web-based platform, LIVECAT, that could practically implement CAT and verified the accuracy and efficiency of our CAT platform. By using this web-based platform based on item response theory, user enable to produce and manage a item bank, conduct tests and report results of tests easily. 141 students of H University attended on this study to demonstrate the accuracy and efficiency of the LIVECAT. As a result, the correlation coefficient between θ estimated through the LIVECAT and θ computed by paper-based test was .779(p<.001). In addition, the length of the test using LIVECAT was about 33% shorter than the length of the paper-based test. In conclusion, if examinees take the exam by using LIVECAT, they can obtain similar results compared to those of a paper-based test with fewer items.

핸드헬드와 스테디캠을 이용한 롱테이크 촬영 기법 연구

고현욱(Hyun-Wook Ko),서동기(Dong-Gi Seo) 한국엔터테인먼트산업학회 2014 한국엔터테인먼트산업학회논문지 Vol.8 No.1s

롱테이크란 카메라를 한 곳에 고정시켜 긴 시간을 담아두는 촬영기법을 말한다. 영화의 기법이 점차 발전하면서 롱테이크에서도 두가지 성향을 볼 수 있는데 그것이 바로 핸드헬드 기법과 스테디캠을 이용한 롱테이크이다. 관객들은 일반적인 롱테이크인 핸드헬드를 통해서 주인공의 감정과 교감 하였고 스테디캠을 사용한 롱테이크의 컷들을 보면서 생동감을 느끼며 빠져들게 되었다. 우리가 기억하는 영화 속에는 이 두 가지 기법의 롱테이크가 사용되었다. 본 논문에서 소개하고자 하는 것은 지금까지 경험하고 보았던 예술적 가치가 발생하는 쇼트의 일부분이었던 핸드헬드와 새롭게 대두되고 있는 스테디캠을 이용한 롱테이크의 이 두가지 롱테이크의 다른 목적에 대해 서술하고 그 활용에 대한 구체적인 방법과 효 과를 분석해 보는 것이 이 연구의 목적이다. Long take refers to a filming technique which is positioning camera in a certain place to film long time. Along with the development in modern society, the filming technique has also improved which made the long take to show two techniques: the "handheld technique" and the "long take using steady cam". Audiences shard their feelings with the character through ordinary long take handheld, and fell into the movie by feeling the movement through cuts of long take using steady cam. These two techniques are used in the movies that we remember. So, what this paper would like to introduce, is the handheld which is the part of shot (which occurs artistic merit) that we experienced and saw until now, and the long take using steady cam which is newly on the rise. In the same time, depicting the purposes of this two long take and analyzing the specific methods and effects about the practical uses of these are the goal of this research.

오메가형 강판을 삽입한 자중저감형 중공 데크플레이트와 TSC 합성보의 성능평가

김성배(Kim Sung-Bae),박동수(Park Dong-Soo),서동기(Seo Dong-Gi),이용교(Lee Yong-Gyo),이창남(Lee Chang-Nam),김상섭(Kim Sang-Seup) 대한건축학회 2011 大韓建築學會論文集 : 構造系 Vol.27 No.7

The purpose of this study is to evaluate the flexural performance of void deck plate inserted omega shaped steel plate (for reducing concrete) and TSC beam. In Composite Beam, install Shear Connectors in order to resist horizontal shear on an interface between two members. And when applying to the void deck plate slab, It can secure the structure that is not only reducing the weight of the building but also eco-friendly. Therefore this study is evaluated the flexural performance by monotonic loading test using actuators. The main parameters are a shape of shear connectors, concrete thickness of upper slabs, and width of haunch. The result of the test, TSC beam applied omega shaped void deck plate has any decline in flexural performance by reduction of concrete slab.

데크플레이트의 직봉을 전단연결재로 활용하는 방안에 관한 연구

김성배(Kim Sung-Bae),박동수(Park Dong-Soo),서동기(Seo Dong-Gi),이용교(Lee Yong-Gyo),김상섭(Kim Sang-Seup) 대한건축학회 2011 大韓建築學會論文集 : 構造系 Vol.27 No.4

Composite Beams have various effects as one unit structural member of a steel beam and a Reinforced Concrete Slab. In Composite Beam, install Shear Connectors to resist horizontal shear on an interface between two members. And when applying to the Deck Plate Slab, vertical Bars are installed for insure safety during the construction. Therefore, this study attempts to examine the ways to develop and utilize a New-Shaped Shear connectors which is functioning as vertical bars and also securing a higher shear capacity using Deformed Bar and Plate instead of Used-Stud Connector.

한국형 역기능우울척도의 개발 및 타당화

김종남(Jong Nam Kim),이순묵(Soonmook Lee),최승원(Seungwon Choi),채정민(Jungmin Chae),서동기(Dong Gi Seo),이헌정(Heon Jeong Lee),원은수(Eun Soo Won) 대한스트레스학회 2018 스트레스硏究 Vol.26 No.2

본 연구는 한국형 역기능우울(dysfunctional depression) 척도를 개발하고 타당화하기 위한 것이다. 자료수집은 우울문제를 주호소로 하는 환자와 내담자를 대상으로 이루어졌으며, 본검사용 40개 역기능우울 문항을 사용하였다. 기존 우울척도와의 문항연계를 통해 분석한 결과(n=360), 최종 20개 문항을 선정하였다. 신뢰도 검증 결과, 높은 내적 일관성을 보였고 검사-재검사 신뢰도에서도 높은 안정성을 보였다. 요인타당도 검증 결과, 일반요인과 함께 특수요인1(신체생리적 요인), 특수요인2(비관적 인식과 소외감 요인)가 추출되었다. 기존 우울척도와의 수렴타당도도 높았다. 마지막으로 기준점수 설정을 위한 전문가 워크샵을 수행한 결과, 일상우울-준임상우울의 기준점수는 44점, 준임상우울-임상우울의 기준점수는 58점이었다. 기준점수 타당화를 위해 분석한 분류일관성과 분류정확성 모두 .85 이상으로 양호하여 기준점수가 타당하게 결정된 것으로 확인되었다. Background: The purpose of this study is to develop and validate the Korean dysfunctional depression scale, which measures pathological depression including subclinical depression and clinical depression. Methods: To achieve this purpose, we collected data from patients diagnosed as having depressive disorder and clients with chief complaints related to depression, and 360 data were analyzed. Results: Using item linkage methods, we decided 20 items as a dysfunctional depression scale for group research. The results of reliability verification show high internal consistency and stable test-retest reliability. In addition, the result of factor validity demonstrates general factor and two specific factors-the first specific factor is ‘the physical-somatic factor’ and the second specific factor is ‘the pessimistic cognition and alienation factor’. Convergent validity was also confirmed good. Lastly, this study performed standard setting workshop consisting of content experts to decide cut-scores of dysfunctional depression scale. Through the workshop, the standard cut-score of normal-subclinical depression was decided as 44 and the standard cut-score of subclinical-clinical depression was decided as 58. The classification consistency and accuracy indices were to validate standard cut-scores. Conclusions: This Korean dysfunctional depression scale is verified to have high reliability and validity.