제주 용암해수로 제조한 쿠키의 품질특성

정성현,전수정,미카일영,문유진,홍예은,권미라,Jung, Sung Hyun,Jeon, Soojeong,Young, Mikhail,Moon, Yoo Jin,Hong, Ye Eun,Kweon, Meera 한국식품조리과학회 2017 한국식품조리과학회지 Vol.33 No.3

Purpose: The present study explored cookie making performance using Jeju magma seawater to elucidate the effects of minerals in water on quality of baked goods. Methods: Seven water samples were analyzed for their mineral content, pH and water hardness. Starch pasting properties of flour in water samples was analyzed using RVA, and cookie making performance using water samples was evaluated with the AACCI wire-cut cookie baking method. Quality of cookies was measured by weight loss during baking, cookie geometry, color, and firmness. Results: Hardness of water samples ranged from 0-4200, and mineral content was in the order of magma seawater > 100% ED mineral water > 50% ED mineral water > 10% ED mineral water > tap water > Samdasoo > distilled water. RVA results showed that water hardness exhibited significant relationships with pasting temperature (p<0.05, R=0.863), peak viscosity (p<0.001, R=0.944), final viscosity (p<0.05, R=0.861), and setback (p<0.05, R=0.782). Cookie baking results showed that cookie diameter increased in the order of magma seawater < 100% ED mineral water < 50% ED mineral water < 10% ED mineral water $\approx$ tap water < Samdasoo < distilled water. Conclusion: As mineral content in water increased, flour pasting temperature and viscosity increased, whereas cookie diameter decreased with color fading. However, cookies formulated with 50% ED mineral water showed similar cookie geometry and texture to those with tap water. Therefore, controlling the mineral content of water can be successfully applied to produce mineral-enriched cookies.

대학육상전공수업의 재미 촉진 및 저해 요인

정성현(Sung Hyun Jung) 한국사회체육학회 2005 한국사회체육학회지 Vol.0 No.23

This study investigated the promotive and interruptive sources of enjoyment in university field and track events. University students(85 man, 35 woman) responded an open-ended question regarding the factors promotive and interruptive sources of enjoyment in field and track events. A total of 468 response(300 promotive and 168 interruptive sources) on the open-ended question were content analyzed. In the 1st subject analysis, the 39 promotive and 43 interruptive dimensions of enjoyment were emerged, and in the details area of 2nd subject analysis, it was divided into the 10 promotive and 9 interruptive dimensions. It the general area of the final classification, the 5 promotive sources were the classes method, classes content, effect of classes, instruction method, and the interruptive sources were classified into classes method, classes content, evaluation, students, educational environment.

구형 미세플라스틱 입자의 침강속도에 관한 실험적 연구

정성현(Sung Hyun Jung),서일원(Il Won Seo),박선구(Sunku Park),이효영(Hyoyoung Lee),김병욱(Byunguk Kim) 한국방재학회 2022 한국방재학회논문집 Vol.22 No.6

최근 해양 및 담수 수계로 유입되는 플라스틱의 양이 급격하게 증가함에 따라서 미세플라스틱(micro-plastics)이 수생태계에 미치는 영향에 대한 연구가 활발하게 수행되고 있다. 수계 내에 유입된 미세플라스틱 입자의 이송 및 확산 거동에 대한 수치 모의와 생태학적 영향 평가를 위해서는 침강속도(settling velocity)특성 규명이 우선적으로 필요하다. 일반적으로 미세플라스틱 입자의 침강거동을 유사 입자(sediment particle)와 유사한 거동을 보인다고 가정하고 있으나, 밀도와 형상 특성이 상이한 미세플라스틱 입자를 대상으로 충분한 실험 및 검증이 수행되지 못했다. 따라서 본 연구에서는 다양한 입경과 밀도를 갖는 구형 미세플라스틱 입자에 대해 입자추적기법을 적용하여 침강 실험을 수행하고, 새로운 침강속도 식의 보정 계수를 제안하였다. 실험결과 층류 영역에서는 Stokes의 관계식과 같은 침강속도와 무차원 입자 직경간에 명확한 선형 관계를 갖는 것으로 나타났으나, 천이 영역에서는 비선형관계로 변화하는 것으로 밝혀졌다. 이러한 천이 영역에서의 비선형성은 항력계수와 입자 레이놀즈수의 관계에서도 명확하게 드러났다. 측정결과를 바탕으로 선행연구에서 제안된 침강속도 경험식의 적용성을 분석한 결과, 유사 입자 기반 경험식들의 경우 20% 이상의 상대 오차를 나타냈다. 본 연구에서 회귀분석을 통해 새롭게 도출된 침강속도 식의 보정 계수를 적용할 경우 기존 유사 입자 연구에서 제안된 경험식들보다 더 높은 예측 정확도를 갖는 것으로 나타났다. Research on the effects of microplastics on water environments is being widely conducted because the discharge of microplastics into the ocean and freshwater systems is rapidly increasing. For the numerical simulation of the transport and diffusion of microplastics introduced into water systems and evaluation of the ecological impacts, the settling velocities of microplastics must be investigated first. The settling behavior of microplastics has been commonly assumed to be similar to that of sediment particles, but this has not been sufficiently verified for various types of microplastic. In this study, a laboratory experiment was performed to measure the settling velocities of spherical microplastic particles in freshwater using a particle tracking technique, and a new calibration coefficient of the settling velocity was proposed based on the experimental data. The experimental results showed a clear linear relationship between the settling velocity and dimensionless particle diameter in the laminar flow region, as suggested by Stokes' law. However, the settling velocities in the transition region had a nonlinear relationship, which was also clearly demonstrated in the relationship between the drag coefficient and the particle Reynolds number. The evaluation of the existing equations for settling velocity showed that previous empirical equations based on experiments on sediment particles produced relative errors of 20% or more. However, the proposed calibration coefficient provided a more accurate prediction of the settling velocities of microplastic particles than the existing empirical equations based on sediment studies.

지체장애인에 대한 한국형 운동중독 척도 적용의 양호도: 문항반응이론 적용

정성현 ( Sung Hyun Jung ),김태형 ( Tae Hyung Kim ) 한국특수체육학회 2009 한국특수체육학회지 Vol.17 No.4

이 연구는 지체장애인에 대한 `한국형 운동중독 척도` 적용의 양호도를 검증하는 것에그 목적이 있다. 연구참여자는 생활체육에 참여하고 있는 지체장애 2급부터 6급까지 총259명(남자 212명, 여자 47명)이다. 수집된 자료는 다국면 Rasch 모형을 이용하여 분석하였으며, 각 국면은 성별, 장애정도, 운동종목이다. 가설 수락을 위한 유의수준은 .05로 설정하였다. `한국형 운동중독 척도` 적용에 대한 각 국면별 반응을 분석한 결과, 성별과 장애정도에 따른 반응수준에는 차이가 없었으나(p=.54, .72), 운동종목에 따른 반응수준에는 차이가 있었다(p<.05). 특히, 양궁의 내적합 제곱 평균이 .5로 나타나 과적합한 것으로 나타났다. 각 문항별 곤란도와 적합도를 분석한 결과, 통계적으로 유의한 것으로 나타났으며, 내적합 제곱 평균이 .7에서부터 1.3사이에 있는 것으로 나타났다. 따라서, `한국형 운동중독 척도`를 생활체육에 참여하고 있는 지체장애인에게 적용하여도 검사의 신뢰도와 타당도는 양호하다. The purpose of this study was to estimate reliability and validity of the Korean exercise addiction scale for people with physical disabled. 259 subjects(212 male, 47 female) with physical disabilities in grade 2-6 participating in sports for all were recruited. The data were analyzed using Many-facet Rasch model and the facets were gender, degree of disability, and exercise type. To select the alternative hypothesis, □ was .05. The results were as follows. There was no significant difference in the degree of response by gender and degree of disability(p=.54 & p=.72) but there was a significant difference in the degree of response by exercise type(p<.05). Specially, archery was overfitting as infit mean square was .5. Analyzing the item difficulty and the goodness of fit of each item, these were statistically significant. Infit mean squares were ranged from .7 to 1.3. Therefore, the exercise addiction scale for Korean was a reliable and valid tool for the physical disabled.

Improved Electrical Contact Property using Ultrathin Al₂O₃ Layers at Metal-Semiconductor Junction

Hyun Joon Ryu(류현준),Sung Hyeon Jung(정성현),Ji Sook Yang(양지숙),Hyung Koun Cho(조형균) 한국표면공학회 2022 한국표면공학회 학술발표회 초록집 Vol.2022 No.11

미세플라스틱 입자의 침강속도에 관한 연구

정성현(Sung Hyun Jung),서일원(Il Won Seo) 대한토목학회 2022 대한토목학회 학술대회 Vol.2022 No.10

생활체육 참여 지체장애인의 성취목표성향, 자기관리, 운동참가의 관계

정성현(Sung Hyun Jung),안동영(Dong Young Ahn),김태형(Tae Hyung Kim) 한국사회체육학회 2010 한국사회체육학회지 Vol.0 No.40

The objective of this research is verifying the causal relations among achievement goal orientation, self-management, and activity participation of the physical disability participating in sport for all, through analyzing measurement model and structural model. 224 physically challenged people, who participated in the sport for all from September to December, 2009, were subject to the study; the data analysis was performed by Amos 16.0 program and the measurement model and structural model were verified. The results of the research work are as follows. First, as a consequence of testing measurement model, 7 questions of achievement goal orientation and 6 questions of self-management were eliminated since they do not show single dimension unidimensionality . The subsequent goodness of fit was appeared to be acceptable. Secondly, it was found that the subordinate concept of achievement goal orientation, or ego goal orientation statically affects their health care and mind control positively, but personal relationships negatively Thirdly, it was found that the subordinate concept of achievement goal orientation, or task goal orientation statically affects their health care, training management, and personal relationship beneficially. Fourthly, it was found that the subordinate concept of self-management, or practice management statically affects the activity participation positively.

유동층 액-액 추출기에서 액적의 크기 및 상승속도

정성현 ( Sung Hyun Jung ),김재한 ( Jae Han Kim ),강태규 ( Tae Gyu Kang ),강용 ( Yong Kang ),김상돈 ( Sang Done Kim ) 한국공업화학회 2005 공업화학 Vol.16 No.1

누에와 혈당강하 활성

정성현(Sung Hyun Chung),류정화(Jung Ha Yu),김은주(Eun Ju Kim),류강선(Kang Sun Ryu) 경희대학교 동서약학연구소 1996 경희약대 논문집 Vol.24 No.-

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신장 조직의 브라디키닌 결합부위 발현

정성현(Sung Hyun Chung),정지창(Jee Chang Jung) 대한약학회 1994 약학회지 Vol.38 No.5

Based upon the previous experiments showing that kidney and lung tissues of rat had relatively abundant bradykinin binding sites, we tried to characterize and determine the densities of the bradykinin binding sites in the rabbit kidney tissue and proximal tubular cells under different growing conditions. Among the kidney tissue renal medulla segments showed the highest bradykinin binding sites. To determine which growth factors are to add in the serum free culture medium to express selectively the bradykinin binding sites in the rabbit kidney proximal tubular cells, we tried so called hormone-deletion approach and in here insulin, hydrocortisone, transferrin, triiodothyronine and prostagiandin E1 are examined. By performing receptor binding assay and determination of protein concentrations, we may conclude that the most required hormones in the expression for bradykinin binding sites are insulin and transferrin, and fetal bovine serum is shown to be less effective in this regard.