• 한국과학교육학회지
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• 제37권6호
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• pp.971-980
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• 2017

이 연구에서는 고등학생의 학교 과학 탐구에서 나타나는 도구발생의 특징을 탐색하였다. 연구 대상은 고등학교의 과학 동아리 활동에 참여한 1, 2학년 학생 23명으로, 학생들은 6개 조로 나뉘어 한 학기동안 과학 탐구를 자율적으로 계획하고 수행하였다. 학생들의 탐구 활동을 녹음 및 녹화하며 관찰하였고, 반구조화된 심층 면담을 실시하였다. 준비물 요청서와 조별 활동지도 수집하여 분석에 활용하였다. 연구 결과는 학생들의 활동을 도구발생의 여부에 따라 범주화하여 제시하였다. 구체적으로 도구발생이 중단된 경우에는 활동 초기에 도구발생이 중단된 사례, 활동 과정에서 도구발생이 중단된 사례를 각각 기술하였다. 또한 도구발생이 일어난 경우에는 도구 조정화, 도구 조정화 및 전용화, 도구 전용화 범주로 세분하고 각 범주에 해당하는 대표 사례를 기술하였다. 도구발생의 여부와 구체적인 특징은 탐구 맥락에서 조명되었고 도구의 어포던스와 연관하여 해석되었다. 연구 결과를 바탕으로 학생들의 과학 활동에서 도구의 위치를 재고하고 연구에의 시사점을 논의하였다.

• 한국유체기계학회 논문집
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• 제2권3호
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• pp.59-66
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• 1999

In this study the effects of nozzle diameter on the performance characteristics for the tangential impeller-type water meter are studied experimentally. The nozzle is cut along the tangential direction of the inner case in the water meter. The nozzle shape is round and the number of nozzles used for the experimental study are 8. The performance characteristics are discussed for various nozzle diameters such as 3.1, 3.3, 3.5, 4.0, 4.5 and 5.0 mm. Among the tangential impeller-type water meters, the water meter with the nozzle diameter of 5.0 mm shows the least pressure loss and the instrumental error compared to the Korean Standards.

• 한국식품과학회지
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• 제7권3호
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• pp.168-180
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• 1975

Analogs and extenders should have mouthfeel and chewing characteristics that are similar to the food they are replacing or extending. Instrumental methods can measure some of the physical properties that constitute 'texture' but only sensory methods can provide a complete description and quantification of the textural properties of a food. Instrumental methods and sensory methods for measuring texture are reviewed.

• 한국연초학회지
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• 제2권2호
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• pp.1-7
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• 1980

오리엔트산 및 한국산 향끽미종 잎담배의 휘발성이 적은 성분들을 간단한 장치와 간단한 조작을 통해 분리 농축하였다. 각 휘발성이 적은 농축물들은 가시 영역에서 흡광도를 측정하고 박층 크로마토그라피 (TLC)와 고성능 액체 크로마토그라피 (HPLC)에 의해서 상세한 조성분석을 하였다. 각 품종간의 정량적인 차이가 가시광선 흡수 스펙트라, TLC 패턴, HPLC프로파일 상에서 확인되었다.

• Nuclear Engineering and Technology
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• 제37권5호
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• pp.503-510
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• 2005

An instrumental neutron activation analysis was used to measure the concentrations of about 24 elements associated with airborne particulates (PM10) that were collected in the most polluted urban region of Daejeon city, Korea from 2000 to 2002. Using the measurement data for various elements, both the extent of elemental pollution in the study area and the seasonality in their distribution characteristics were examined. Examinations of their distribution patterns indicated that most elements with crustal origin tend to exhibit seasonal peaks during spring, while most elements with anthropogenic origin tend to exhibit seasonal peaks during fall or winter. In order to explain the factors regulating their mobilization properties, the data were processed by a factor analysis. Results of the factor analysis suggested competing roles of both industrial and natural source processes, despite that the study site is located at a downwind position of the industrial complex. Based on the overall results of this study, it is concluded that the site may be strongly impacted by man-made sources but the general patterns of elemental distributions in the study area inspected over a seasonal scale are quite consistent with those typically observed from natural environment.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.688-693
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• 2002

Identification method is formulated to evaluate the dynamic characteristics of air bearings under NFR(Near Field Recording) sliders. Impulse responses and frequency response functions of NFR sliders are obtained on numerical non-linear models including rigid motion of slider and fluid motion of air bearing under the slider. Modal parameters and system parameters are identified by modal analysis method and instrumental variable method. The parameters of sliders are utilized to evaluate the dynamic characteristics of air bearings. Also, this study shows the difference between the dynamic characteristics of NFR and HDD slides, and squeeze effect of air bearings.

• 한국식품조리과학회지
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• 제20권2호
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• pp.170-179
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• 2004

The purpose of this study was to investigate the instrumental and sensory characteristics of coffee-sulgi(rice cake) with different ratios of the ingredients; coffee(30$m\ell$, 40$m\ell$ and 50$m\ell$ of espresso and instant coffee) and sugar (50g and 75g). A commercial scheme for coffee-sulgi was also investigated. The optimal mixing ratios of coffee-sulgi with added espresso were rice flour 500g, salt 5g, espresso 40$m\ell$ and sugar 75g. Those of coffee-sulgi with added instant coffee were the same. As the sensory intensities of coffee aroma, coffee taste, sweetness, moistness, elasticity, color acceptance for coffee-sulgi and overall acceptance for quality were enhanced, the overall preference for coffee-sulgi was increased. In addition, overall preference was positively correlated with adhesiveness and a-value of instrumental characteristics, but negatively correlated with cohesiveness and L-value. In coffee-sulgi with added espresso, intensities of coffee aroma, browniness, coffee taste, color acceptance for coffee-sulgi, overall acceptance for quality and overall preference were higher than those of coffee-sulgi with added instant coffee. In this point, gourmet coffee-sulgi with added espresso and universal coffee-sulgi with added instant coffee could be differentiated in the coffee-sulgi markets. In conclusion, this study of coffee-sulgi and the differential scheme for the market will be useful to expand rice processing, enhance the intake of rice cakes and provide a reference for the commercialization of rice cakes.

• 한국식품과학회지
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• 제16권3호
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• pp.303-308
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• 1984

물성적(物性的) 특성(待性)을 다르게 제조한 츄잉검을 가지고 Rheometer를 사용하여 저작단계별로 초기(初期)에 puncture test, 중기(中期)에 penetration test, 후기(後期)에 penetration test 및 compression test를 하여 기계적(機械約) 물성(物性)을 측정 하였고 같은 시료로 훈련(訓練)된 파넬과 소비자(消費者) 관능검사를 실시하여 관능적(官能的) 물성(物性) 및 기호성(嗜好性)을 측정하였다. 이들 측정 된 물성값으로 기계적(機械約) 물성간(物性間)의 상관관계와 관능적(官能的) 물성간(物性間)의 상관관계를 구하여 물성간(物性間)의 유사성(類似性)과 상관성을 조사하였다. 기계적(機械的) 물성(物性)에서 초기(初期)의 puncture work와 puncture force, 중기(中期)의 hardness와 work, 후기(後期)의 hardness와 work 및 adhesion work와 adhesion force는 각각 유사(類似)한 물성(物性)으로 해석되었으며 후기(後期)의 yield force와 slope는 hardness와, springiness와 adhesion force는 slope와 상관관계가 높았다. 관능적(官能的) 물성(物性)에서 소비자(消費者)와 훈련(訓練)된 파넬의 관능검사 결과(結果)는 거의 일치(一致)하였고 소비자의 경우 초기(初期)의 stiffness가 중기(中期), 후기(後期)의 firmness와 상관관계가 높았다. 훈련(訓練)된 파넬의 경우 후기(後期)의 stiffness는firmness와, cohesion은 lift와 각각 유사(類似)한 물성(物性)으로 해석되었으며 adhesion은 firmness와 부(負)의 상관관계를 나타내었다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.677-684
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• 2004

This paper describes a method for identifying the dynamic characteristics of air foil bearings for high speed turbomachinerys with the LS/IV method. In fact identifying the characteristics of air foil bearings is very difficult work, and it is tried to identify it. Experiments were conducted to determine the structural dynamic and hydrodynamic characteristics of air foil bearings. Numerical predictions compare the static and dynamic force performances. The housing of the bearing on the journal was driven by the impact hammer which were used to simulate impact force acting on air foil bearings. The characteristics of air foil bearings were extracted from the frequency response function (FRF) by LS(Least Square) method and IV(Instrumental Variable) method. The experiment was tested at 0 rpm and $10000\sim16000rpm$. And the test results were introduced about the dynamic characteristics of air foil bearings, and also compared with theoritical results.

• 한국직업건강간호학회지
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• 제24권4호
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• pp.352-362
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• 2015

Purpose: The purpose of this study was to investigate the effects of job stress and support from supervisors on depression of care givers in elderly care facilities. Methods: Subjects were 191 care givers working in elderly care facilities in K-Province in Korea. Data were collected from self-administered questionnaires. Descriptive statistics, ${\chi}^2$ test, t-test, F-test, Pearson's and Spearman's correlation coefficients, and hierarchical multiple logistic regression with dummy variables were used for statistical analysis of data. Results: Job stress measured with Korean Occupational Stress Scale was $56.16{\pm}5.88$. Emotional and instrumental support from supervisors were $37.05{\pm}7.30$ and $32.39{\pm}7.34$, respectively. After controlling for general characteristics, job stress was significantly related to depression (OR: 1.07, 95% CI: 1.01~1.14). However, job stress became non-significant in the model that included instrumental support from supervisors. Not emotional but instrumental support from supervisors was significantly related to depression of care givers (OR: 0.93, 95% CI: 0.88~0.99). Conclusion: Results of this study suggest that job stress has negative effects and instrumental support from supervisors has protective effects on depression of care givers in elderly care facilities. Therefore, measures to increase instrumental support by supervisors should be developed to improve psychological health of care givers in elderly care facilities.