• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.346-347
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• 2019

본 논문에서는 3.3 [kW] on-board charger (OBC) 용 phasw-shifted full-bridge (PSFB) 컨버터의 고효율 및 고전력 밀도 달성을 위한 스위칭 주파수 설계 방안을 제안한다. 스위칭 주파수에 따라 달라지는 손실 양상 및 전력 밀도에 대해 분석하기 위해 각 스위칭 주파수 별 반도체 소자 손실과 수동 소자 손실을 계산하고, 수동 소자의 부피 변화에 따른 전력밀도 변화를 분석한다. 분석 결과를 바탕으로 고효율 및 고전력밀도 달성을 위한 시스템 설계 포인트를 선정하고 시뮬레이션을 통하여 설계 결과를 검증한다.

• Korean Journal of Food Science and Technology
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• v.48 no.4
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• pp.366-371
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• 2016

This study was carried out to evaluate the feasibility of using domestic wheat flour as ingredient of pizza dough by examining the physicochemical and sensory properties of the dough. Five pizza dough samples were prepared with different ratio of domestic and imported wheat flour. Significant differences were observed in crude protein content, crude ash content, and color of the pizza dough samples; however, no significant difference was found in mechanically measured rheology. A sensory evaluation based on 23 descriptive attributes indicated significant differences between pizza dough made from domestic wheat flour and that made from imported wheat flour for springiness and softness of the surface, roughness, and chewiness (p<0.05). Principal component analysis showed that the greater amount of Korean wheat flour in the dough resulted in different values from negative to positive ends of principal component 1 (37.4%).

• Journal of Applied Tourism Food and Beverage Management and Research
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• v.16 no.2
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• pp.1-15
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• 2005

This study was intended to make Korean type of sourdough bread using domestic wheat produced in Korea, while measuring and analyzing gluten content, pH level, TTA level and mixograph of wheat to extract the most excellent sourdough starter. Furthermore, this study also used CrumbScan to compare and analyze the properties of product as shown in making sourdough bread with the above starter. pH level ranged from 4.0 to 4.5 throughout all kinds of Korean wheat four, which were considered to be appropriately available as sourdough starter. As the result of analysis from mixogram, SF fit for making bread but korean wheat flour showed less level of mixing tolerance and content of protein, which were considered inappropriate for making bread. As the result of imaging analysis by CrumbScan, SF, KWF 5 and KWF 6 showed the higher fineness and elongation than any other kind of korean wheat flour, which were considered appropriate for making bread.

• Proceedings of the Korea Hospitality Industry Research Society Conference
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• 2005.11a
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• pp.134-146
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• 2005

This study was intended to make Korean type of sourdough bread using domestic wheat produced in Korea, while measuring and analyzing gluten content, pH level, TTA level and mixograph of wheat to extract the most excellent sourdough starter. Furthermore, this study also used CrumbScan to compare and analyze the properties of product as shown in making sourdough bread with the above starter. pH level ranged from 4.0 to 4.5 throughout all kinds of Korean wheat flour, which were considered to be appropriately available as sourdough starter. As the result of analysis from mixogram, SP fit for making bread but korean wheat flour showed less level of mixing tolerance and content of protein, which were considered inappropriate for making bread. As the result of imaging analysis by CrumbScan, SF, KWF 5and KWF 6 showed the higher fineness and elongation than any other kind of korean wheat flour, which were considered appropriate for making bread.

• Journal of the Institute of Convergence Signal Processing
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• v.5 no.4
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• pp.281-286
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• 2004

The wear process of end mill is a so complicated process that a more reliable technique is required for the monitoring and controling the tool life and its performance. This research presents a new tool wear monitoring method based on the sound signal generated on the machining. The experiment carried out continuous-side-milling for using the high-speed steel end mill under wet condition. The sound pressure was measured at 0.5m from the cutting zone by a dynamic microphone, and was analyzed at frequency domain. The tooth passing frequency appears as a harmonics form, and end mill wear is related with the first harmonic. It can be concluded from the result that the tool wear is correlate with the intensity of the measured sound at tooth passing frequency estimation of end mill wear using sound is possible through frequency analysis at tooth passing frequency under the given circumstances.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3D
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• pp.287-293
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• 2008

Density is used as the measure of effectiveness within the ramp junction influence area suggested in the KHCM 2005 in the LOS analysis of the ramp junction, and also density predictive models suggested in the KHCM 2005 is constructed based on the expressway with the speed limit of 100km/h or 110km/h in Korea. So, the density predictive models suggested in the KHCM 2005 are needed to verify if the models could be applied to the urban freeway with the speed limit of 80km/h or less, because the speed limits on most of the urban freeways in Korea are 80km/h or less. The purpose in this study is to construct and verify the appropriate density predictive model within the on-ramp merge influence area of the urban freeway by comparing with the USHCM 2000 and KHCM 2005 models.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.4
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• pp.20-29
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• 2014

Density is applied both three major macroscopic traffic variables (traffic volume, speed, and density) and two measures of effectiveness (MOE) for level of service (LOS) on highway (density and V/C). Especially, it is known for the most accurate MOE on evaluating the LOS of highway. Despite such importance, there is a lack of study on density relatively than other variables for its difficulty of measurement. Existing density estimation methods have some limitations such as density values of same traffic flow vary with collecting time. In this study, we researched actual density measuring method with panoramic image, after each CCTV images in the Sapaesan Tunnel on Seoul Ring Expressway are matched into one panoramic image. Analysis through the Central Limit Theorem shows that density of 24 1 km-images, which means 24 second, applies traffic situation well. That is to say that reasonable density value regardless of collecting time, and practical density which represents actual traffic flow can be taken in case of measuring density by suggested collecting cycle.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.98-98
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• 2019

중력류 또는 밀도류는 주변 유체에 비해 상대적으로 밀도가 큰 유체가 밀도차에 의한 추진력으로 흐르는 것이다. 중력류의 수치모델링에는 두 가지 어려움이 있다. 즉, 적합한 지배방정식을 구성하여 적용하는 것 그리고 난류의 영향을 합리적으로 반영하는 것이다. 기존 중력류 해석을 위한 지배방정식들은 유체의 연속방정식과 운동량 방정식 그리고 밀도 또는 농도의 이송방정식을 조합하여 구성된다. 이들 지배방정식을 이용한 연구들은 대부분 두 유체 사이의 밀도차가 충분히 작아서 밀도 변동(variations)의 영향은 오로지 부력항에서만 유지된다는 Boussinesq 근사에 근거를 둔다. 그리고 이송방정식에서 밀도 또는 농도의 확산계수을 점성계수의 함수로 표현하기 위해서 Schmidt 수를 이용한다. 수치모델링에서 Schimdt 수는 상수값을 적용하지만, 이 값은 밀도의 연직방향 경사에 근거한 부력빈도(buoyancy frequency)와 난류량의 따라 큰 차이를 보이는 것으로 알려져있다. 한편, 표준 통계학적 난류모델과 벽함수를 적용한 수치모델링은 초기 중력에 의해서 무너지는(slumping) 단계를 넘어 관성력으로 추진되는 단계와 점성 효과가 지배적인 단계에서는 정확도에 현저히 낮아지기 때문에 대부분 큰와모의(large-eddy simulation, LES) 또는 DNS(direct numerical simulation)수준의 고해상도(high-resolution) 해석기법을 적용하여 공학적인 문제에 적용하는 데는 한계가 있다. 이 연구에서는 Boussinesq 근사와 Schmidt 수를 사용하지 않으며, LES 보다 적용이 용이한 DES (detached-eddy simulation)기법을 조합한 다상흐름 수치모델을 적용하여 중력류를 해석을 시도하였다. 수치해석결과를 실험값과 함께 기존 수치모델링 기법으로 구한 수치해와 비교분석하여 이 연구에서 개발 및 적용된 수치모델링 기법의 적용성을 평가한다.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2001.05a
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• pp.32-35
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• 2001

본 연구에서는 폰트를 식별할 수 있는 모듈을 제공하고 각 폰트마다 가지고있는 감성정보를 추출한다. 각 폰트의 특징 추출을 위해 세그먼트 폭 밀도함수를 사용한다. 각 폰트가 가지는 고유한 밀도함수로부터 폰트를 식별할 수 있다. 두 번째 모듈로서 각 폰트가 수반하는 감성정보를 추출한다. 각 폰트가 갖는 감성정보는 사용자기반의 감성데이타를 수집하고 이를 퍼지 멤버쉽을 이용하여 정의한다. 즉, 폰트정보만을 분석함으로서도 문서, E메일, 웹 문서 등에서 폰트가 수반하는 감성정보를 추출할 수 있다.

• KOREAN POULTRY JOURNAL
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• v.3 no.10 s.24
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• pp.60-63
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• 1971

옥수수 수입가격의 앙등으로 인하여 옥수수를 대치할 수 있는 수수, 밀, 보리등의 이용방법을 사료업계에서 논의하고 있는 이 때에 아미노산의 영양적 성분과 이용을 이해할 필요가 있다. 무엇보다 아미노산 분석표의 적합성을 항상 고려하여 아미노산의 유효성에 관한 실험결과를 참작하여야 할 것이다. 옥수수, 수수, 밀, 보리 같은 식물성 단백질에 공통적으로 결핍되어 있는 아미노산은 주로 라이신, 알지닌, 메치오닌, 시스틴, 드레오닌이며 이 아미노산의 유효성은 사료분석표에 나타나 있는 함량과 다르다는 점에 특별히 유의하여야 될 것이다. 국내사료자원의 개발이 절실히 요구되는 이때에 고 라이신 옥수수(opaque-2)와 같은 수수, 밀, 보리가 우리나라에서도 재배 개량되기를 바라마지 않는다.