• Imaging Science in Dentistry
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• 제54권2호
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• pp.147-157
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• 2024

Purpose: The aim of this study was to explore the correlations of cone-beam computed tomographic findings with the apnea-hypopnea index in patients with obstructive sleep apnea. Materials and Methods: Forty patients with obstructive sleep apnea were selected from the ear-nose-throat (ENT) outpatient clinic, Faculty of Medicine, Mansoura University. Cone-beam computed tomography was performed for each patient at the end of both inspiration and expiration. Polysomnography was carried out, and the apnea-hypopnea index was obtained. Linear measurements, including cross-sectional area and the SNA and SNB angles, were obtained. Four oral and maxillofacial radiologists categorized pharyngeal and retropalatal airway morphology and calculated the airway length and volume. Continuous data were tested for normality using the Kolmogorov-Smirnov test and reported as the mean and standard deviation or as the median and range. Categorical data were presented as numbers and percentages, and the significance level was set at P<0.05. Results: The minimal value of the cross-sectional area, SNB angle, and airway morphology at the end of inspiration demonstrated a statistically significant association (P<0.05) with the apnea-hypopnea index, with excellent agreement. No statistically significant difference was found in the airway volume, other linear measurements, or retropalatal airway morphology. Conclusion: Cone-beam computed tomographic measurements in obstructive sleep apnea patients may be used as a supplement to a novel radiographic classification corresponding to the established clinical apnea-hypopnea index classification.

• 대한건축학회논문집:구조계
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• 제36권1호
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• pp.173-178
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• 2020

In this study, we analyzed space heating and domestic hot water(DHW) charges from 2017 to 2018 for 151,206 households in 202 apartment complexes built from 1997 to 2016, in order to evaluate the effectiveness of Korea's insulation standards reinforcement. The applied insulation standards were revised three times(in 1987, 2001 and 2010). We used the Anderson-Darling test to review the normality of the space heating and DHW charges. As a result, each p-value was greater than 0.05 and it followed the normal distribution. The annual average space heating charges per unit area of apartments with the 1987 insulation standards were 5,237￦/㎡a in 2017 and 5,328￦/㎡a in 2018. The heating charges with the 2001 standards were 4,827￦/㎡a in 2017 and 4,817￦/㎡a in 2018. Compared to previous standards(1987 standards), heating charges decreased by 7.8% and 9.6%. Also the heating charges with the 2010 standards were 3,683￦/㎡a in 2017 and 3,734￦/㎡a in 2018. Compared to previous standards(2001 standards), heating charges decreased by 24.3% and 21.5%. On the other hand, compared to each previous standards, DHW charges were decreased by 12.2%, 13.6% or increased by 4.6%, 6.9%, which means there's no correlation between insulation standards reinforcement and DHW charges.

• 대한토목학회논문집
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• 제10권3호
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• pp.107-113
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• 1990

압축성(壓縮性) 모래를 사용하여 주응력(主應力)을 각기 독립적으로 조절할 수 있는 입방체삼축시험(立方體三軸試驗)을 하였다. 그 결과 초기(初期) 변형계수(變形係數)는 b값의 증가와 더불어 증가하고 중간주응력(中間主應力)이 b값이 적을 때는 주변형율간(主變形率間)의 거동(擧動)에 영향을 미치지 못하고 배수(排水) 경우는 b=0.3, 비배수(非排水)경우는 b=0.6 값에서부터 b값이 커질수록 최대주변형율(最大主變形率)(${\varepsilon}_1$) 값이 더 적은 값에서 파괴(破壞)된다. 파괴시(破壞時) 소성변율(塑性變形率) 중분벡터의 방향은 배수조건(排水條件)에 무관하고 직교조건은 3축면(三軸面)에서는 만족되지 않으나 팔면체면(八面體面)에서는 만족되는 재료(材料)임을 알았다.

• 한방재활의학과학회지
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• 제29권3호
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• pp.87-101
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• 2019

Objectives The purpose of this study is to investigate characteristics of low back pain patients and trends of Korean medicine conservative treatment effects of low back pain patients by registry data. Methods A total of 78 patients were analyzed, statistical analysis was performed using a generalized linear model. The comparison between groups was performed using independent two samples t-test or Wilcoxon rank sum test according to the distribution of normality. Before and after the treatment effects, ANOVA and Kruskal-Wallis method were used for the comparison, Sheffe method was used for the post test. Results The average age of hospitalized patients was 31.8 years old and out-patient department (OPD) patients was 44.9 years old. Lots of OPD patients and hospitalized patients were classified to 'Lumbago due to Coexist Qu Stagnation and Bloos Stasis'. Both OPD patients and hospitalized patients classified to 'Lumbago due to Coexist Qu Stagnation and Bloos Stasis' showed statistically significant decrease in RMDQ (Roland-Morris disability questionnaire) and NRS (numeric rating scale) on 1 month and 3 month after clinical research start date. Comparing the treatment effects of Chuna manual therapy, both Chuna group and non-Chuna group showed statistically significant decrease in RMDQ and NRS on discharge date, 1 month and 3 month after clinical research start date. Conclusions We expect that a larger scale registry study will be carried out to provide a higher level of basis for the Korean medical treatment of low back pain.

• 한국산업보건학회지
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• 제24권4호
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• pp.547-555
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• 2014

Objective: This study was conducted to investigate the association between subjective distress symptoms and argon welding among workers in Gyeongnam Province shipyard. Method: 31 argon and 29 non-argon welding workers were selected as study subjects in order to measure concentrations of personal dust, welding fumes and other hazardous materials such as ZnO, Pb, Cr, FeO, MnO, Cu, Ni, $TiO_2$, MgO, NO, $NO_2$, $O_3$, $O_2$, $CO_2$, CO and Ar. An interviewer-administered questionnaire survey was also performed on the same subjects. The items queried were as follows: age, height, weight, working duration, welding time, welding rod amounts used, drinking, smoking, and rate of subjective distress symptoms including headache and other symptoms such as fever, vomiting and nausea, metal fume fever, dizziness, tingling sensations, difficulty in breathing, memory loss, sleep disorders, emotional disturbance, hearing loss, hand tremors, visual impairment, neural abnormality, allergic reaction, runny nose and stuffiness, rhinitis, and suffocation. Statistical analysis was performed using SPSS software, version 18. Data are expressed as the mean ${\pm}SD$. An ${\chi}^2$-test and a normality test using a Shapiro wilk test were performed for the above variables. Logistic regression analysis was also conducted to identify the factors that affect the total score for subjective distress symptoms. Result: An association was shown between welding type (argon or non-argon welding) and the total score for subjective distress symptoms. Among the rate of complaining of subjective distress symptoms, vomiting and nausea, difficulty breathing, and allergic reactions were all significantly higher in the argon welding group. Only the concentration of dust and welding fumes was shown to be distributed normally after natural log transformation. According to logistic regression analysis, the correlations of working duration and welding type (argon or non-argon) between the total score of subjective distress symptoms were found to be statistically significant (p=0.041, p=0.049, respectively). Conclusion: Our results suggest that argon welding could cause subjective distress symptoms in shipyard workers.

• 대한간호학회지
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• 제22권4호
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• pp.620-635
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• 1992

This study identified correlations between perceived family support and hopelessness in patients admitted to Neuro - surgical Intensive Care Units. The purpose was to enhance theoretical understanding of the relationships of these two variables. The subjects of this study were 51 patients admitted to N-lCU, at three general hospitals in Seoul. Data were collected by researcher in structured interviews from Aug. 12 to Oct. 13, 1992. The research tools were parts of the Moos Family Environment Scale and the Beck Hopelessness Scale. The general characteristic data were analyzed for frequency and percentage ; the hypothesis was tested by the pearson product Moment Correlation Coefficient. After normality tests by using Kolmogorov - Sminorvtest, and T- test, ANOVA and Mann-Whitney U test, Kruskal -Wallis test were used on the Family Support and the Hopelessness about general charcteristics. The results of the above analysis were as follows 1) The average family support score for the group was 63.61 (tool average 51) and item average was 3.74 (tool item average 3) : the family support score of this sample was higher than average. The average family cohesion score of family support was 35.25 (tool average 27) and item average was 3.91 (tool item average 3). The average family expression score of family support was 28.35 (tool average 24) and item average was 3.57 (tool average 3). In this sample, perceived family expression was lower than family cohesion. 2) The average hopelessness score was 45.88 (tool average 60) and item average was 2.29 (tool item average 3) : the hopelessness score of this sample was low in comparison to the average. 3) The hypothesis in this study was supported. The main hypothesis that the higher the perceived family support level, the lower the level Of the hopelessness, was Supported (r＝-.3869 p＝.003). The sub-hypothesis that the higher the perceived family cohesion level, the lower the level of hopelessness, was supported(r＝-.3688 p＝.004). The sub-hypothesis that the higher the perceived family expression level, the lower the level of hopelessness, was supported (r＝-.3068 p＝.014). 4) General characteristics of the objects related to family support were ‘economic status’(p＝.025) and ‘helping person’(P＝.044) : the higher the economic status, the greater the family support. When the patient identified the helping person as a spouse, family support was rated more highly. The only general characteristic related to family cohesion was ‘helping person’(p＝.041). No general characteristics were related to family expression. 5) The one general characteristic related to hopelessness was ‘education’(p＝.002) : the higher their education, the lower their hopelessness. For these ICU patients, were related perceived family support and hopelessness, and family expression level was low in comparison to family cohesion level. The perceived family support of these seriously ill patients in situational crisis may have influenced the patient's emotional reaction of hopelessness. This study concluded that nurses in the ICU confirm the family support of the patient, and involve the family as the most intimate support systems in the care of the patient to help reduce the patient's hopelessness.

• 한국산학기술학회논문지
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• 제19권8호
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• pp.193-200
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• 2018

대학교부설 과학영재교육원은 전국에 27개가 과학기술정보통신부의 지원으로 운영되고 있으며 각 과학영재교육원에는 수학, 물리, 화학, 생물, 지구과학, 정보반이 개설되고 있다. 과학영재의 특징으로는 지적요인뿐만 아니라 정의 및 동기요인이 영재성을 규명하는데 중요한 준거가 된다. 정보영재 학생들을 위한 컴퓨팅 사고력의 구성요소를 가지는 교육과정을 개발하였다. 그 교육과정이 정보영재의 정의적 영역인 컴퓨터 과학적 태도에 효과가 있는지를 분석하기 위하여 TOSRA를 수정하여 검사지를 개발하였다. 개발된 교육과정을 K 대학교부설 과학영재교육원의 중학교 1-2 학년생으로 구성된 정보반 학생들을 대상으로 1년간 수업을 진행하면서 정보영재 학생들의 컴퓨터 과학적 태도검사를 실시하여 t-검정으로 비교 분석하였다. 검사결과에 의하면 과학영재교육원에서 진행한 교육과정의 컴퓨터 과학적 태도는 유의도 수준 0.05에서 유의한 차이가 있었다. 컴퓨터과학의 사회적 시사영역, 컴퓨터과학 탐구에 대한 태도영역, 컴퓨터 기술자의 평범함영역은 유의도 수준 0.05에서 유의한 차이가 있었으나 컴퓨터 과학적 태도의 수용영역, 컴퓨터과학 수업의 즐거움영역, 컴퓨터과학 관련 취미에 대한 관심영역, 컴퓨터과학 관련 직업에 대한 관심영역은 유의도 수준 0.05에서 유의한 차이가 없었다.

• 유통과학연구
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• 제13권9호
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• pp.103-112
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• 2015

Purpose - This paper aims to provide a step-by-step approach to factor analytic procedures, such as principal component analysis (PCA) and exploratory factor analysis (EFA), and to offer a guideline for factor analysis. Authors have argued that the results of PCA and EFA are substantially similar. Additionally, they assert that PCA is a more appropriate technique for factor analysis because PCA produces easily interpreted results that are likely to be the basis of better decisions. For these reasons, many researchers have used PCA as a technique instead of EFA. However, these techniques are clearly different. PCA should be used for data reduction. On the other hand, EFA has been tailored to identify any underlying factor structure, a set of measured variables that cause the manifest variables to covary. Thus, it is needed for a guideline and for procedures to use in factor analysis. To date, however, these two techniques have been indiscriminately misused. Research design, data, and methodology - This research conducted a literature review. For this, we summarized the meaningful and consistent arguments and drew up guidelines and suggested procedures for rigorous EFA. Results - PCA can be used instead of common factor analysis when all measured variables have high communality. However, common factor analysis is recommended for EFA. First, researchers should evaluate the sample size and check for sampling adequacy before conducting factor analysis. If these conditions are not satisfied, then the next steps cannot be followed. Sample size must be at least 100 with communality above 0.5 and a minimum subject to item ratio of at least 5:1, with a minimum of five items in EFA. Next, Bartlett's sphericity test and the Kaiser-Mayer-Olkin (KMO) measure should be assessed for sampling adequacy. The chi-square value for Bartlett's test should be significant. In addition, a KMO of more than 0.8 is recommended. The next step is to conduct a factor analysis. The analysis is composed of three stages. The first stage determines a rotation technique. Generally, ML or PAF will suggest to researchers the best results. Selection of one of the two techniques heavily hinges on data normality. ML requires normally distributed data; on the other hand, PAF does not. The second step is associated with determining the number of factors to retain in the EFA. The best way to determine the number of factors to retain is to apply three methods including eigenvalues greater than 1.0, the scree plot test, and the variance extracted. The last step is to select one of two rotation methods: orthogonal or oblique. If the research suggests some variables that are correlated to each other, then the oblique method should be selected for factor rotation because the method assumes all factors are correlated in the research. If not, the orthogonal method is possible for factor rotation. Conclusions - Recommendations are offered for the best factor analytic practice for empirical research.

• 한국산학기술학회논문지
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• 제21권7호
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• pp.537-543
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• 2020

4차 산업혁명 시대에 필요한 인재를 양성하기 위해서는 정보영재를 선발하여 체계적으로 교육하는 것이 필요하다. 영재의 정의적 특성은 자아개념, 성격, 사회성, 성취동기, 도덕성, 태도나 흥미 등을 들 수 있으며 성취도에 영향을 끼치는 중요한 요소이며 특히 컴퓨터 과학적 태도는 컴퓨터과학 학습의 출발점 행동으로 컴퓨터과학 성취도에 영향을 미치는 중요 변인이다. 본 연구에서는 정보영재의 정의적 특성을 측정하기 위하여 Fraser가 개발한 TOSRA를 기반으로 컴퓨터 과학적 태도 검사 도구를 개발하였다. 컴퓨터 과학적 태도 검사 도구는 컴퓨터과학의 사회적 시사영역, 컴퓨터과학 탐구에 대한 태도영역, 컴퓨터 과학적 태도의 수용영역, 컴퓨터과학 수업의 즐거움영역, 컴퓨터과학 관련 취미에 대한 관심영역, 컴퓨터과학 관련 직업에 대한 관심영역, 컴퓨터과학자의 평범함 영역으로 7개의 영역으로 구성된다. 개발된 검사 도구를 사용하여 정보영재 학생들의 컴퓨터 과학적 태도와 학업성취도간의 관계를 분석하였다. 컴퓨터 과학적 태도가 학업성취도를 유의하게 예측하는지를 확인하기 위하여 회귀분석을 실시한 결과 t=2.543, p=0.025로 유의 수준 .05에서 컴퓨터 과학적 태도의 평균이 학업성취도를 유의하게 예측하였다.

• 벤처창업연구
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• 제16권6호
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• pp.157-175
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• 2021

본 연구는 기술보증기금이 2017년부터 2019년까지 기술평가를 통하여 보증 지원한 기술 중소기업 중 3,214개 기업을 대상으로 4차 산업혁명 기업과 일반 중소기업으로 구분한 후 경영 특성이 고성장 기업 결정에 미치는 영향을 실증 분석하였다. 고성장 기업 판단은 OECD(2007)의 정의를 적용하여 최근 2년간 매출액 증가율이 연간 평균 20% 이상인 기업이다. 표본 대상의 두집단이 비정규분포를 따르고 있어 Mann-Whitney U test 비모수 검증으로 평균치 차이 분석을 하였다. 또한 정규성 가정이 덜 엄격한 이변량 로지스틱 회귀분석을 실시하였다. 독립변수는 대표자 역량, 인적자본 역량, 기술혁신 역량, 기본 특성, 지역더미, 기술수준 더미이다. 이에 대응하는 하위변수는 대표자 학력, 대표자 동업종 경험 수준, 상시 종업원, 연구 인력, 지식 재산권 수, 연구개발 투자금액, 기업 업력, 총자산, 지역_수도권, 지역_중부권, 기술수준_첨단기술, 기술수준_중기술이다. 분석결과, 4차 산업혁명 기업은 대표자 동업종 경험수준, 상시종업원, 기업업력, 총자산, 기술수준_첨단기술의 연구가설이 지지되었다. 일반 중소기업은 대표자 동업종 경험수준, 연구인력, 총자산, 지역_수도권의 연구가설이 지지되었다.