• 폴리머
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• 제26권2호
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• pp.218-226
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• 2002

산화에틸렌 함량, 분자량 및 분자사슬의 구조가 다른 폴리에테르형 기포개방제를 사용하여 고탄성 폴리우레탄 발포체를 제조하고 이 때 기포개방제의 구조 변화가 계의 반응속도, 유변학적 성질, 발포체의 구조적인 안정성, 개방기포 함량 및 기계적인 성질 등에 미치는 영향을 조사하였다. 기포개방제의 산화에틸렌 함량 증가와 분자사슬에 에스테르 결합의 도입에 따라 우레아 생성 반응이 지연되었으나, 기포개방제의 분자량은 큰 영향이 없음을 관찰하였다. 유변학적 성질의 관찰로 기포개방제의 산화에틸렌 함량과 분자량의 증가에 따라 반응물의 점도와 저장탄성율의 감소를 확인하였고, 이 때 얻어진 발포체는 낮은 구조적인 안정성과 높은 개방기포 함량을 가졌다. 에스테르 결합이 도입된 기포개방제는 가장 낮은 점도와 저장탄성율을 나타내었고 제조된 발포체는 높은 개방기포 함량을 가졌으며, 또한 에스테르 결합에 의해 증가된 분자간 힘으로 인해 구조적인 안정성이 증가하였다 발포체의 경도, 인장강도, 인열강도, 신율은 기포개방제의 산화에틸렌 함량과 분자량의 증가에 따라 저하하였으나, 에스테르 결합이 도입된 기포개방제의 경우에는 우수한 인장강도, 인열강도, 신율을 나타내었다.

• 한국초등과학교육학회지:초등과학교육
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• 제27권4호
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• pp.356-370
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• 2008

The study aims to explore sequence of earth science content in elementary school science curriculum in Korea and the U.S.. The analysis is focused on a) general content structure of earth science part; b) concept relationship between grades in the specific field of 'geology'; c) longitudinal connection of concepts and content in 'geology.' The findings are as follows. First, earth science curriculum content in Korea is structured according to sub-scientific disciplines centering on not science concepts but topics or inquiry activities whereas the U.S. curricular content is organized through integrative earth science topics with basic concepts and sub-concepts. Second, it is a common feature that basic concepts are interrelated to sub-concepts in all grades in both countries. However, basic concepts are scattered all over the grades, presented in a linear pattern in Korea while those are provided together in 3rd grade and repeated with extended concepts in a spiral structure in the U.S.. Last, it is not clear how concepts and content are longitudinally connected between grades in Korean curriculum. On the contrary, concepts and content in the U.S. curriculum have a strong longitudinal connection between grades with conceptual hierarchy. Such results indicate that Korean elementary school science curriculum would limit students' comprehensive understanding of science concepts through grades. The study suggests Korean science content should strengthen interrelationship among concepts as well as longitudinal connection between grades, in order to achieve the ultimate goal of science education, 'scientific literacy'.

• 음성과학
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• 제8권2호
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• pp.133-148
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• 2001

Focus and information structure are closely related with the distribution of pitch accents. A focused word conveys new information and bears a pitch accent. A content word can usually get a pitch accent, but it can be deaccented if it is mentioned earlier in the discourse. In this paper, we test how English native speakers and Korean learners of English realize pitch accents according to focus and information structure of a sentence. The production experiment shows that English native speakers give a pitch accent to narrow-focused items, deaccenting all the other items of the sentence. For VP broad focus, native speakers give a pitch accent either to both the verb and its complement or to the complement only. On the other hand, it is found that Koreans give pitch accents to most content words regardless of focus and information structure. Moreover, the perception experiment confirms that Koreans' intonation patterns, which are not appropriate in terms of focus and information structure, may jeopardize listeners' comprehension. This paper shows that Korean speakers have little knowledge about focus and information structure for intonational realization, and that such notions should be applied to teaching of English intonation.

• 정보처리학회논문지D
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• 제8D권5호
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• pp.451-460
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• 2001

본 논문에서는 XML 문서의 효율적인 구조 검색을 위한 색인 모델을 제안한다. 색이 모델은 문선 계층상의 모든 레벨에서 내용 기반 질의와 구조 및 에트리뷰트 질의와 같은 다양한 질의를 지원하기 위한 구조정보와 이를 이용한 색이 구조로 구성된다. 구조검색을 지원하기 위해 새로운 구조정보 표현 방법을 제안한다. 제안한 구조정보 표현 방법에 따라 표현된 구조정보를 이용해 효율적인 검색을 위한 내용 색인, 구조 색인, 에트리뷰트 색인을 구성한다. 또한 내용과 구조가 혼합된 질의의 처리과정을 설명하고, 제안하는 색인 모델의 성능평가를 보임으로써 기존의 방법보다 성능이 우수함을 보인다.

• Food Science and Biotechnology
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• 제16권5호
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• pp.832-835
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• 2007

Moisture content of normal, waxy, and high amylose com starches was adjusted to 10-35%, and irradiated in a microwave oven. The effect of microwave irradiation on the crystalline structure of starch was measured by using a differential scanning calorimetry (DSC), and X-ray diffractometry. Pasting viscosity profile was also determined by using a rapid viscoanalyzer (RVA). For all the 3 types of starches tested, the rate of temperature increase by the microwave irradiation was faster and more rapidly reached the maximum temperature of the pressure bomb ($120^{\circ}C$) when the moisture content was higher. X-ray diffraction and DSC data revealed that the microwave irradiated starch underwent partial disruption of crystalline structure. RVA studies showed that the irradiation caused significant reductions in maximal viscosity and breakdown, whereas pasting temperature was increased. Overall trends revealed that the microwave irradiation on the starch containing limited moisture content (less than 35%) provided the effects similar to the heat moisture treatment. These effects became more significant when the moisture content was higher. Compared to waxy com starch, normal, and high amylose com starches appeared to be more susceptible to the microwave irradiation.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.8-9
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• 2021

The unit-water content of concrete is one of the important factors in determining the quality of concrete and is directly related to the durability of the construction structure, and the current method of measuring the unit-water content of concrete is applied by the Air Meta Act and the Electrostatic Capacity Act. However, there are complex and time-consuming problems with measurement methods. Therefore, high frequency moisture sensor was used for quick and high measurement, and unit-water content of mortar was evaluated through machine running and deep running based on measurement big data. The multi-input deep learning model is as accurate as 24.25% higher than the OLS linear regression model, which shows that deep learning can more effectively identify the nonlinear relationship between high-frequency moisture sensor data and unit quantity than linear regression.

• 한국환경복원기술학회지
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• 제7권3호
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• pp.64-72
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• 2004

The research was carried out to define the environmental characteristics and vegetation structure of the evergreen fern habitat in Jejudo. The growth conditions of evergreen fern in various habitats was surveyed, including topographical features, vegetation structure, air temperature, humidity, intensity of light, water content and organic matter content in the soil. In the direction of the native habitat, 70% of research area was located in the southeast-facing slopes, 30% was located in southern slopes. The gradient ranged from $0^{\circ}$ to $30^{\circ}$. Temperature ranged from $16^{\circ}C$ to $28^{\circ}C$, and $22.3^{\circ}C$ was the average. Humidity ranged from 20 to 68%, and 36% was the average. In the native habitat, the highest light intensities reached 60,000 to 80,0001ux, but in general ranged from 300 to 40001ux. Water content in the soil ranged from 32% to 59%, organic matter content ranged from 8 to 13%. Within a unit of 25$m^2$, there were tall-tree layer such as Quercus galuca and Castanopsis cuspidata with a covering of rate 40~80%, a sub-tall-tree layer such as Camellia japonica, Staphylea bumalda and Sambucus williamsii with the covering rate of 3~5%, a shrub layer with the covering rate of 5~20%, and a grass layer with the covering rate of 40~95%. This research provides the basic data about the native habitat environment of the evergreen fern plant. Continuous monitoring and accumulation of data is necessary for the use of evergreen fern as vegetation materials.

• 디지털융복합연구
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• 제18권4호
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• pp.433-438
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• 2020

미디어 환경과 콘텐츠의 제작 기술이 급속히 발달하면서 멀티 플랫폼 기반의 융·복합 트랜스미디어 시대가 대두되었고, 트랜스미디어 콘텐츠를 통한 의사소통 방식이 주목받게 되었다. 트랜스미디어 콘텐츠는 개별적 콘텐츠가 멀티 플랫폼으로 트랜스 되는 개념을 말하며, 이 때 컨버전스라는 확장된 세계관을 구축하게 되는데, 또한 이 과정에서 발생되는 인터랙션은 콘텐츠의 진행에 있어 매우 중요하면서도 통제하기 어려운 요인으로 작용한다. 본 논문에서는 이에 대한 해결 방안으로써 트랜스미디어 콘텐츠와 게이미피케이션 개념과의 결합에 주목하였고, 게임 디자인을 실행하기 위한 분석 및 접근법에 관한 이론체계인 'MDA 프레임 워크'를 기반으로 게임 디자인의 구조를 살펴보았다. 기술과 감성의 밸런스를 통한, 가치와 재미의 경험에 대한 예측 체계를 세우는 원론적인 게임 디자인의 구조에 대한 고찰이 트랜스 미디어 콘텐츠 설계에 있어 기초적 토대로써 도움이 될 것으로 기대한다.

• 한국연소학회지
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• 제19권1호
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• pp.17-28
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• 2014

In this study, the laminar burning velocity of syngas fuel($H_2/CO$) and flame structure with various hydrogen contents were studied using both experimental measurements and detailed kinetic analysis. The laminar burning velocities were measured by the angle method of Bunsen flame configuration and the numerical calculations including chemical kinetic analysis were made using CHEMKIN Package with USC-Mech II. A wide range of syngas mixture compositions such as $H_2$ : CO = 10 : 90, 25 : 75, 50 : 50, 75:25 and equivalence ratios from lean condition of 0.5 to rich condition of 5.0 have been considered. The experimental results of burning velocity were in good agreement with previous other research data and numerical simulation. Also, it was shown that the experimental measurements of laminar burning velocity linearly increased with the increment of $H_2$ content although the burning velocity of hydrogen is faster than the carbon monoxide above 10 times. This phenomenon is attributed to the rapid production of hydrogen related radicals such as H radical at the early stage of combustion, which is confirmed the linear increase of radical concentrations on kinetic analysis. Particular concerns in this study are the characteristics of burning velocity and flame structure different from lean condition for rich condition. The decrease of OH radicals and double peaks are observed with $H_2$ content in rich condition once $H_2$ fraction exceeds over threshold.

• 한국디지털정책학회:학술대회논문집
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• 한국디지털정책학회 2004년도 춘계학술대회
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• pp.53-67
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• 2004

On the base of IT growth, competition between countries for preoccupation of digital content market is keen. And it is prospected that the development of digital content industry will be more rapid with the base of telecommunication infra-structure(for example internet, digital broadcasting) which is the main channel for distribution of digital content. The bill of "Act for Development of Online Digital Content Industry", has passed the national assembly jan, 2002, and "Draft Blueprint for Developing Online Digital Content Industry(2003$\sim$2005)" was made on the base on that law feb, 2003. And we can find measures for protect the digital content manufacture in the laws such as "Literary Property Law", "Trademarks Law" and "law for prevention of unfair competition". On this study we suggested three measures to make digital content industry more profitable by the method of research of related law and industry survey.