• 응용통계연구
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• 제27권7호
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• pp.1077-1095
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• 2014

관찰연구를 이용하여 인과관계를 추론할 경우 무작위 통제시험과는 달리 교란변수로 인한 편향을 제어하기 위한 통계적 전략이 필요하다. 최근에는 성향점수(propensity score) 를 이용한 짝짓기나 원인변수의 역확률을 가중치로 사용하는 주변구조모형이 제안되어 사용되고 있다. 이러한 인과관계 추론은 처치(treatment)가 명확히 주어진 경우에 교란변수를 통제하고 그 처치가 결과에 미치는 영향을 평가하는 방법에 초점이 맞추어져 있다. 하지만 기존의 방법의 경우 원인변수인 처치가 직접관측이 가능한 범주형 변수이고 결과변수 또한 직접관측이 가능한 변수인 경우에만 사용할 수 있는 한계를 갖고 있다. 본 연구에서는 원인변수인 처치와 결과변수의 결괏값의 직접적인 관측이 어려운 경우, 측정오차를 고려한 잠재범주모형(latent class analysis)의 변수로 모형화 함으로써 잠재범주 간의 원인적 영향력을 추정하는 방법을 제시하고자 한다. 그리고 미국의 The National Longitudinal Study of Adolescent Health 자료를 이용하여, 약물사용의 잠재범주에 대한 청소년기의 비행(delinquency)이라는 잠재범주의 원인적 영향력을 추정하였다.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제30권2호
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• pp.74-82
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• 2019

Objectives: The objective of this study was to investigate clinical and neuropsychological factors associated with treatment response and adverse events of atomoxetine in children with attention-deficit/hyperactivity disorder (ADHD) in Korea. Methods: Children with ADHD were recruited at the Department of Psychiatry of Asan Medical Center from April 2015 to April 2018. Diagnoses of ADHD and comorbid psychiatric disorders were confirmed with the Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version. The subjects were subsequently treated with atomoxetine for 12 weeks and illness severity was scored using the ADHD Rating Scale, Clinical Global Impression-Severity scale (CGI-S) and/or Improvement scale (CGI-I), at pre- and post-treatment. They also completed the Advanced Test of Attention (ATA), while their caregivers completed the Korean Personality Rating Scale for Children (KPRC) at pre- and post-treatment. Independent t-test, Fisher's exact test, ${\chi}^2$ test, mixed between-within analysis of variance and correlation analysis were used for statistical analysis. Results: Sixty-five children with ADHD (mean age: $7.9{\pm}1.4years$, 57 boys) were enrolled, of which, 33 (50.8%) were treatment responders. Scores on the social dysfunction subscale of the KPRC (p=0.021) and commission errors on the visual ATA (p=0.036) at baseline were higher in treatment non-responders than in responders; however, the statistical significances disappeared after adjusting for multiple comparisons. Mood changes were also observed in 13 subjects (20.0%), and three of them discontinued atomoxetine due to this. Additionally, atomoxetine-emergent mood change was observed more frequently in girls (p=0.006), while the intelligence quotient (p=0.040) was higher in those subjects with mood changes than in those without. Conclusion: The results of our study suggest that clinical and neuropsychological factors could be associated with treatment response or adverse events of atomoxetine in children with ADHD. Further long-term studies with larger samples are needed.

• 상하수도학회지
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• 제35권1호
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• pp.53-61
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• 2021

The quantified analysis of damages to wastewater treatment plants by natural disasters is essential to maintain the stability of wastewater treatment systems. However, studies on the quantified analysis of natural disaster effects on wastewater treatment systems are very rare. In this study, a total disaster index (DI) was developed to quantify the various damages to wastewater treatment systems from natural disasters using two statistical methods (i.e., AHP: analytic hierarchy process and PCA: principal component analysis). Typhoons, heavy rain, and earthquakes are considered as three major natural disasters for the development of the DI. A total of 15 input variables from public open-source data (e.g., statistical yearbook of wastewater treatment system, meteorological data and financial status in local governments) were used for the development of a DI for 199 wastewater treatment plants in Korea. The total DI was calculated from the weighted sum of the disaster indices of the three natural disasters (i.e., TI for typhoon, RI for heavy rain, and EI for earthquake). The three disaster indices of each natural disaster were determined from four components, such as possibility of occurrence and expected damages. The relative weights of the four components to calculate the disaster indices (TI, RI and EI) for each of the three natural disasters were also determined from AHP. PCA was used to determine the relative weights of the input variables to calculate the four components. The relative weights of TI, RI and EI to calculate total DI were determined as 0.547, 0.306, and 0.147 respectively.

• Journal of Acupuncture Research
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• 제34권3호
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• pp.23-38
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• 2017

Objectives : The purpose of this study was to evaluate the clinical prognostic factors affecting facial palsy in 98 idiopathic facial palsy patients who were hospitalized and treated in 2015, using retrospective statistical analysis. Methods : We investigated patients with idiopathic facial nerve palsy, admitted to a Korean medical hospital in 2015, and examined patients' variables and therapeutic variables. For analysis of clinical data, an independent sample t-test, analysis of variance (ANOVA), and simple regression analysis were performed using IBM SPSS version 24.0. Results : 1. The initial degree of facial palsy showed statistical significance with age. The older the age, the more severe the initial palsy. 2. Following treatment degree of facial palsy was statistically significant with age, hypertension, and fasting blood sugar (FBS). The higher the value, the slower the recovery from facial palsy. There was a statistical significance with the number of treatments in a Korean medical hospital. The more frequent the treatment, the faster the facial palsy recovery. 3. Degree of facial palsy after 12 months was statistically significant with age, hypertension, diabetes, FBS, and the initial severity of facial palsy. The higher the value, the slower the facial palsy recovery. 4. Sex, left or right sided palsy, alcohol consumption, smoking, history of facial palsy, season of onset, total number of treatments and bio chemistry (BC), complete blood cell count (CBC), urinalysis (UA) factors had no statistical significance with prognosis of facial palsy. Conclusion : Age, season of onset, hypertension, diabetes, FBS, initial severity of facial palsy, and the number of treatments at a Korean medical hospital showed statistical significance. The number of treatments at the Korean medical hospital positively correlated with facial palsy prognosis, and the others variables showed a negative correlation with facial palsy prognosis.

• Nuclear Engineering and Technology
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• 제16권1호
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• pp.36-46
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• 1984

가압경수로의 정상운전상태는 물론 예상 과도상태에서도 노심내에서 DNB가 발생하지 않아야 된다는 설계근거를 만족시키는 새로운 설계방법 즉, 통계처리에 의한 열설계 방법이 개발되어 이에 대하여 검토하였다. 이같은 설계방법을 사용하여 설계변수에 대한 불확실도를 통계적으로 처리함으로써 노심설계에 따른 설계여유도를 정량적으로 계산할 수 있어 원자로심의 안전성을 충분히 유지하면서도 DNB비례산에 따른 불필요한 보수성을 배제할 수 있다. 본 기술검토보고서는 미국의 Westing-house와 B & W원자로 제작회사가 개발한 통계적 열설계방법을 소개하고 본 설계방법의 특성을 설명하며 이어서 불확실도의 통계처리 과정, DNB설계 제한치 설정방법, 그리고 본 방법의 응용 결과를 비교하여 보여준다. 본 검토를 통하여 두 회사의 설계방법은 근본적으로 유사하나 통계처리를 위한 설계변수의 선택과 이들 불확실도의 처리방법이 다소 상이하다는 것을 알았으며 또한 본 방법의 사용으로 노심설계에 있어서 설계여유도가 현저히 증가한다는 것을 알았다.

• 대한물리치료과학회지
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• 제4권1호
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• pp.291-301
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• 1997

This study was conducted to fine out factors related with the complains low back pain in eldery persons. The Questionnaires was done for 273 eldery persons who live in Pusan, Anyang, Ansan region from May 1996 ro April 1997. The results were as follows : 1. The prevalence rate were 49.5% and among them 20.74% were male was while 68.12% which shows high prevalance of female 2. There were no statistical significance except sex difference(P>0.05) 3. There statistical different with some factor fators which includes general health condition, the frequency of treatment, sleeping bed style, condition for future life (P<0.05). But showed no statistical significance with the other factors. 4. When compared between rural and urban area, there were some statistical difference among some factor such as ; where to treat, moring exercise frequency, walking duration, sleeping bed style, agricultural work involement, prepartory condition for future life.(P<0.05)

• 대한치과교정학회지
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• 제30권1호
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• pp.91-99
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• 2000

본 연구는 조선대학교 치과대학 부속치과병원 교정과에 내원한 환자 중 악태모형을 제작하고 CPI (condylar position indicator) 에 의한 하악과두의 위치를 평가하여 중심위 -중심교합 편위양이 전후방 및 수직적으로 1.0 mm 이내, 측방으로 0.3 mm 이내인 정상 범주를 벗어나는 성인 여자 환자 16명을 대상으로 교합안정장치를 3개월간 장착하고, 이들을 장착 기간에 따라 장착 직전, 장착 1개월 후, 장착 2개월 후, 장착 3개월 후로 분류하여 교합안정장치의 장착에 따른 교합력과 교합접촉점 수의 변화 여부를 평가하기 위해 T-scan system을 이용하여 다음과 같은 결론을 얻었다. 1. 교합력의 변화는 교합안정장치 장착 직전에서 장착 1개월 후 사이에 유의성 있게 감소되었다 (P<0.05). 2. 교합력의 변화는 교합안정장치 장착 1개월 후부터 장착 3개월 후 까지는 유의한 차이를 보이지 않았다 (P>0.05). 3. 전치부 교합접촉점 수의 변화는 장착기간에 관계없이 유의성있는 차이가 없었다 (P>0.05). 4. 구치부 교합접촉점 수의 변화는 교합안정장치 장착 직전에서 장착 1개월 후 사이에 유의성 있게 감소되었다 (P<0.05). 5. 구치부 교합접촉점 수의 변화는 교합안정장치 장착 1개월 후부터 장착 3개월 후 까지는 유의한 차이를 보이지 않았다 (P>0.05). 6. 교합접촉점 수의 변화는 전치부에서 보다는 구치부에서 절대적으로 영향을 미쳤다. 이상을 종합해볼 때, 교합안정장치는 장착 1개월 후면 어느정도 중심위로의 하악골 안정을 기대할 수 있을것으로 사료된다.

• The Journal of Korean Physical Therapy
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• 제19권5호
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• pp.43-49
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• 2007

Purpose: The purpose of this study was to the effects of temporomandibular joint movement restriction on treatment of SCM muscle pain. Methods: The Subjects(n=20) were males(n=7) and females(n=13) that had SCM muscle pain and movement restriction at one side oftemporomandibular joint. The massage and Taping performed on the SCM muscle during 4 weeks. The measured items of SCM pain were pressure-pain scale, DITI. The measured items of temporomandibular joint movement restriction were VAS, ROM, deviation. Results: SCM muscle of pressure-pain scale is lower in ipsilateral than counterlateral, But temperature is higher in ipsilateral than counterlateral. Pressure-pain scale was statistical significance (p<0.05). After studying, the pain and temperature of SCM muscle was decreased and statistical significance(p<0.05). After studying, VAS of Temporomandibular joint was decreased, ROM was increased, deviation was decreased. All of measured items of Before and after studying found a statistical significance(p<0.05). Conclusion: This study showed that SCM muscle pain related TM joint pain and movement restriction. The patient with TM joint movement restriction that may take effect on reducing SCM muscle pain.

• Communications for Statistical Applications and Methods
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• 제23권1호
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• pp.1-20
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• 2016

Causal inference methodologies have been developed for the past decade to estimate the unconfounded effect of an exposure under several key assumptions. These assumptions include, but are not limited to, the stable unit treatment value assumption, the strong ignorability of treatment assignment assumption, and the assumption that propensity scores be bounded away from zero and one (the positivity assumption). Of these assumptions, the first two have received much attention in the literature. Yet the positivity assumption has been recently discussed in only a few papers. Propensity scores of zero or one are indicative of deterministic exposure so that causal effects cannot be defined for these subjects. Therefore, these subjects need to be removed because no comparable comparison groups can be found for such subjects. In this paper, using currently available causal inference methods, we evaluate the effect of arbitrary cutoffs in the distribution of propensity scores and the impact of those decisions on bias and efficiency. We propose a tree-based method that performs well in terms of bias reduction when the definition of positivity is based on a single confounder. This tree-based method can be easily implemented using the statistical software program, R. R code for the studies is available online.

• Communications for Statistical Applications and Methods
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• 제15권4호
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• pp.497-507
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• 2008

동일 환경에서 할 수 있는 실험의 크기가 2인 경우 $2^n$요인실험과 그 일부실시법을 설계하려면 교락법을 반복적으로 사용해야한다. $2^n$요인실험 또는 그 일부실시법의 교락법들을 적절히 조합하면 모든 주효과와 2인자 교호작용효과 전부 또는 일부를 검출할 수 있는 실험을 설계할 수 있다. 이런 실험을 설계하기 위해 정의대비를 이용했고 설계된 실험의 처리조합을 제시하였다.