• Korean Chemical Engineering Research
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• 제59권4호
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• pp.644-651
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• 2021

Alkyl amines are widely used in various industries. Nowadays these are also used in CO₂ capture technology because amines react with CO₂ and remove it from the flue gas. To make the amines more compatible towards this technology, physico chemical properties may be altered by mixing with other solvents. In the present report, we measured the refractive properties of pure diisopropylamine (DIPA) (1) + isomeric butanol (2) at 298.15 K to 308.15 K. The 𝚫n values were positive for DIPA + n-butanol or sec-butanol or isobutanol or tert-butanol mixtures. The measured data was correlated with Redlich-Kister equation. The excess molar volume data were predicted from refractive index data using Nakata and Sakurai model. The experimental data were also predicted by various correlations, and the prediction capability of these correlations was reported through standard deviation. Further, the deviation in refractive index (𝚫n) data was interpreted by the consideration of specific molecular interactions between DIPA and isomeric butanol.

• 대한불안의학회지
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• 제16권2호
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• pp.106-112
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• 2020

Objective : Social anxiety disorder (SAD) is characterized by fear of social threat and exhibits limbic hyper-reactivity toward social stimuli such as emotional faces. A previous study identified the uncinate fasciculus (UF) sub-tract as particularly related to facial memory. To explore the white matter tract relating to face-specific brain regions, we investigated the UF sub-tract in SAD. Methods : The diffusion tensor images of 22 patients with SAD and 20 healthy controls were analyzed with tractography. The UF sub-tract was delineated using the regions of interest of face patches in the anterior temporal lobe and the orbitofrontal cortex, and fractional anisotrophy (FA) and total number of streamlines (ST) were analyzed. We examined the group comparison of FA and ST of the UF sub-tract and correlations of FA and ST with the social anxiety symptoms such as the Liebowitz Social Anxiety Scale (LSAS), the Social Interaction Anxiety Scale (SIAS), the Social Phobia Scale (SPS) and the Fear of Negative Evaluation scale (FNE) in SAD. Results : There were no group differences in FA and ST of the UF sub-tract. However, negative correlations were observed between ST of the right UF sub-tract and severity of social anxiety symptoms (LSAS, r_s=-0.480, p=0.024; SIAS, r_s=-0.580, p=0.005; SPS, r_s=-0.590, p=0.004; FNE, r_s=-0.675, p=0.001) in patients with SAD. Conclusion : Although patients with SAD did not show quantitative abnormalities in the UF sub-tact connecting face-specific brain regions, this structure seems to play a role in the symptom severity of SAD.

• Journal of Chest Surgery
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• 제54권6호
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• pp.487-493
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• 2021

Background: Predicting postoperative lung function after pneumonectomy is essential. We retrospectively compared postoperative lung function to predicted postoperative lung function based on computed tomography (CT) volumetry and perfusion scintigraphy in patients who underwent pneumonectomy. Methods: Predicted postoperative lung function was calculated based on perfusion scintigraphy and CT volumetry. The predicted function was compared to the postoperative lung function in terms of forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV₁), using 4 parameters: FVC, FVC%, FEV₁, and FEV₁%. Results: The correlations between postoperative function and predicted function based on CT volumetry were r=0.632 (p=0.003) for FVC% and r=0.728 (p<0.001) for FEV₁%. The correlations between postoperative function and predicted postoperative function based on perfusion scintigraphy were r=0.654 (p=0.002) for FVC% and r=0.758 (p<0.001) for FEV₁%. The preoperative Eastern Cooperative Oncology Group (ECOG) scores were significantly higher in the group in which the gap between postoperative FEV₁ and predicted postoperative FEV₁ analyzed by CT was smaller than the gap analyzed by perfusion scintigraphy (1.2±0.62 vs. 0.4±0.52, p=0.006). Conclusion: This study affirms that CT volumetry can replace perfusion scintigraphy for preoperative evaluation of patients needing pneumonectomy. In particular, it was found to be a better predictor of postoperative lung function for poor-performance patients (i.e., those with high ECOG scores).

• 한국통신학회논문지
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• 제37권5A호
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• pp.367-374
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• 2012

본 논문에서는 binary offset carrier (BOC) 신호를 위한 새로운 상관함수 주변첨두 제거 기법을 제안한다. 제안한 기법은 BOC 자기상관함수를 구성하는 부상관함수의 결합에 기반을 두고 있으며, 수신기에서 보조 신호를 필요로 하지 않고, sine 위상 및 cosine 위상 BOC 신호에 모두 적용이 가능하다. 또한 모의실험 결과를 통해 제안한 기법이 기존의 기법들에 비해 더 좋은 신호 추적 성능을 가짐을 보인다.

• 대한통합의학회지
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• 제6권4호
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• pp.83-90
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• 2018

Purpose : This study aims to examine the correlation between SPQ (sasang personality questionnaire) results and the significance level of general mental and physical health among youths. Effects of physical factors on the level of health are also examined. Methods : For the purpose of this study, the SPQ test and body mass and the Ponderal index were measured. The SPQ was followed by a survey on physical changes among 686 young people. The correlation between SPQ and BMI was analysed using Pearson's corelation. Post hoc tests were conducted on SPQ sub factors (SPQ-B, SPQ-C, and SPQ-E) were examined. Results : The findings from the analysis of the high, middle and lower group profiles of adolescent SPQ-B, SPQ-C, and SPQ-E showed that the three groups had significant results. This study demonstrates the correlations among sub factors of the SPQ. No correlation was observed regarding physical characteristics. Conclusion : This study demonstrates the correlations among sub factors of the SPQ. No correlation was observed regarding physical characteristics.

• 한국콘텐츠학회논문지
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• 제12권11호
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• pp.539-548
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• 2012

본 연구에서는 보육교사의 역할갈등, 셀프 리더십이 심리적 복지에 미치는 영향에 대하여 연구하였다. 연구대상은 서울과 경기도에 소재한 어린이집 64개를 선정하여 보육교사 260명을 대상으로 상관계수와 중 다회귀분석을 실시하였다. 연구결과는 첫째, 보육교사의 역할갈등, 셀프 리더십, 심리적 복지 간의 관계를 살펴보면, 역할 스트레스와 역할모호성, 행동지향, 건설적 사고는 긍정적 복지가, 역할모호성과 행동지향은 긍정적복지가, 그리고 자연보상과 부정적복지의 하위변인을 제외한 모든 하위영역에서 상관이 있는 것으로 나타났다. 둘째, 중다회귀분석 결과, 심리적 복지에 영향을 미치는 가장 높은 변인은 자연보상, 역할모호성, 그리고 역할스트레스 순으로 나타난 반면, 그 외 모든 하위변인에서는 통계적으로 유의미한 예측변인이 아닌 것으로 나타났다.

• Nuclear Engineering and Technology
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• 제52권11호
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• pp.2442-2451
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• 2020

The safety level of Sodium Fast Reactors is directly related with the sodium void reactivity. A low-void effect design has been proposed within the Horizon2020 ESFR-SMART project thanks to the introduction of a sodium plenum above the active core. In order to assess the impact of this core conception on transient analysis, a map with the spatial distribution of sodium void worth can be computed and fed into a point-kinetics-based transient code. Due to the spatial correlations between neighboring zones, the global effect of voiding two different axial or radial regions is not necessarily the sum of both individual contributions. Neglecting those correlations in the void worth map and consequently in the transient analysis may lead to an unrealistic prediction of the transient sequences. In this work, a method based on sensitivity analysis and similarity assessment is proposed for predicting those correlations. The method proved to be able to establish correlations between axial slices of a sub-assembly and was checked against realistic sodium void propagation patterns.

• 한국대기환경학회지
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• 제3권1호
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• pp.13-26
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• 1987

One-year-old seedlings of Ginkgo biloba, potted in three different soils (nursery soil, mixed and sandy soil), were treated with simulated acid rain (pH 2.0, 3.0, 4.0 and 5.0) and tap water (control, pH 6.4) during the growing seasons (1985. 4. 28 - 1985. 10. 19) to examine the effects of acid rain on growth and physiological characteristics, and the relations between seedling growth and physiological characteristics. The results obtained in this study were as follows: 1. The effects of soil types on the total, top and root dry weight per seedling were significant at 5% level, and those of the pH of the rain treated at 1% level. The total dry weight of the pH 3.0 sub-plots was the highest for nursery soil, while for mixed and sandy soils, those of the control and the pH 5.0 sub-plots were the highest, respectively. 2. The leaf surface areas of pH 2.0 sub-plots severely decreased after July, but those of other sub-plots were not affected. The correlations between growth and leaf surface area differed among soil-types, however, the highest positive correlation was found in September. 3. The injured leaf rate increased with decreasing pH levels of acid rain. Highly negative correlations between growth and injured leaf rate were found. 4. The lower the pH level of acid rain treated was, the more the chlorophyll content was measured at the beginning of treatment, and the more severely it decreased at late growing season. A negative correlations were found in August, September and Octobfer. 5. The photosynthetic ability decreased rapidly after July with decreasing pH levels. A highly positive correlation between growth and photosynthetic ability was found in August.

• Journal of Advanced Marine Engineering and Technology
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• 제33권6호
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• pp.827-834
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• 2009

The cooling heat transfer coefficient of $CO_2$ in a brazing type small diameter tube was investigated experimentally. The main components of the refrigerant loop are a receiver, a $CO_2$ compressor, a mass flow meter, an evaporator and a brazing type small diameter tube as a test section. The mass flux of $CO_2$ is $400{\sim}1600$ [kg/$m^2s$], the mass flowrate of coolant were varied from 0.15 to 0.3 [kg/s], and the cooling pressure of gas cooler were from 8 to 10 [MPa]. The cooling heat transfer coefficients of the brazing type small diameter copper tube is about $4{\sim}11.7%$ higher than that of the conventional type small diameter copper tube. In comparison with test results and existing correlations, correlations failed to predict the cooling heat transfer coefficient of $CO_2$ in a brazing type small diameter copper tube. therefore, it is necessary to develope reliable and accurate predictions determining the cooling heat transfer coefficient of $CO_2$ in a brazing type small diameter copper tube.

• 한국보육학회지
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• 제17권4호
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• pp.145-161
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• 2017

본 연구의 목적은 예비보육교사의 NCS 직업기초능력, 교직 인 적성 및 DISC 행동유형 간의 관계를 분석하는데 있다. 연구대상은 경기도에 소재한 D대학의 예비보육교사 110명을 대상으로 하였다. 'NCS 직업기초능력측정검사', '교직 인 적성 검사도구', 그리고 'DISC 행동유형 검사도구'를 사용하여 연구자료를 수집하였으며 수집된 자료는 Pearson 적률 상관계수를 통해 검증하였다. 연구결과, 첫째, 주도성의 성격요인은 수리능력과 유의미한 정적 상관이 있는 것으로 나타났으며 사교성의 성격요인은 자기개발능력과 유의미한 정적상관이 있는 것으로 나타났고, 안정성의 요인은 수리능력, 문제해결능력, 자기개발능력, 기술능력, 조직이해능력과 유의미한 부적상관이 있는 것으로 나타났다. 둘째, 직업기초능력과 교직 인 적성의 관계를 분석한 결과 대부분의 직업기초능력과 교직 인 적성의 요소들 간에 유의미한 상관이 나타났다. 셋째, 주도성의 특성은 문제해결력/탐구력, 판단력, 창의/응용력, 지도성, 지식/정보력, 계획성, 성실/책임감과 같은 영역에서 유의미한 정적상관이 나타난 반면에서 안정성은 문제해결력. 탐구력, 판단력, 창의응용력, 지도성, 성실/책임감과 유의미한 부적상관이 있는 것으로 나타났다.