PURPOSES: The national highways and expressways in Korea constitute a total length of 17,951 km. Of this total length of pavement, the asphalt pavement has significantly deteriorated, having been in service for over 10 years. Currently, hot in-place recycling (HIR) is used as the rehabilitation method for the distressed asphalt pavement. The deteriorated pavement becomes over-heated, however, owing to uncontrolled heating capacity during the pre-heating process of HIR in the field. METHODS: In order to determine the appropriate heating method and capacity of the pre-heater at the HIR process, the heating temperature of asphalt pavement is numerically simulated with the finite element software ABAQUS. Furthermore, the heating transfer effects are simulated in order to determine the inner temperature as a function of the heating system (IR and wire). This temperature is ascertained at 300 ℃, 400℃, 500℃, 600℃, 700°℃, and 800℃ from a slab asphalt specimen prepared in the laboratory. The inner temperature of this specimen is measured at the surface and five different depths (1 cm, 2 cm, 3 cm, 4 cm, and 5 cm) by using a data logger. RESULTS: The numerical simulation results of the asphalt pavement heating temperature indicate that this temperature is extremely sensitive to increases in the heating temperature. Moreover, after 10 min of heating, the pavement temperature is 36%~38% and 8%~10% of the target temperature at depths of 25 mm and 50 mm, respectively, from the surface. Therefore, in order to achieve the target temperature at a depth of 50 mm in the slab asphalt specimen, greater heating is required of the IR system compared to that of the gas. CONCLUSIONS : Numerical simulation, via the finite element method, can be readily used to analyze the appropriate heating method and theoretical basis of the HIR method. The IR system would provide the best heating method and capacity of HIR heating processes in the field.
PURPOSES : The applicability of the mechanics-based similarity concept (suggested by Feng et al.) for determining scaled variables, including length and load, via laboratory-scale tests and discrete element analysis, was evaluated. METHODS: Several studies on the similarity concept were reviewed. The exact scaling approach, a similarity concept described by Feng, was applied in order to determine an analytical solution of a free-falling ball. This solution can be considered one of the simplest conditions for discrete element analysis. RESULTS : The results revealed that 1) the exact scaling approach can be used to determine the scale of variables in laboratory tests and numerical analysis, 2) applying only a scale factor, via the exact scaling approach, is inadequate for the error-free replacement of small particles by large ones during discrete element analysis, 3) the level of continuity of flowable materials such as SCC and cement mortar seems to be an important criterion for evaluating the applicability of the similarity concept, and 4) additional conditions, such as the kinetics of particle, contact model, and geometry, must be taken into consideration to achieve the maximum radius of replacement particles during discrete element analysis. CONCLUSIONS : The concept of similarity is a convenient tool to evaluate the correspondence of scaled laboratory test or numerical analysis to physical condition. However, to achieve excellent correspondence, additional factors, such as the kinetics of particles, contact model, and geometry, must be taken into consideration.
This study was conducted, using 10 high-quality rice varieties, at 24 experimental sites in 2013 and 2014 to analyze the comparative relationship among head rice yield (HRY), its attributes and sub-attributes. In the data set pooled across sites, years and varieties, where regional and varietal variations were combined, HRY was associated with milled rice yield (MRY) more closely than percentage of head rice (PHR) although both MRY and HRY demonstrated significant relationship with HRY. In the PHR higher than 80%, compared to 80% or less, fitness of the regression between PHR and HRY decreased. MRY and PHR, the two attributes of HRY, were not significantly associated with each other. Regional variation of HRY was associated only with MRY while varietal variation of HRY was related to both MRY and PHR. HRY and MRY showed regional variation greater than varietal variation meanwhile PHR demonstrated regional and varietal variations in a similar range. In the data set pooled across sites, years and varieties, MRY demonstrated relationship with spikelets per square meter (SPIK) in a higher significance than percentage of grain filling (PGF) and 1000-brown rice weight (TBRW). Both regional and varietal variations of MRY showed significant relationship only with SPIK, neitherwith PGF nor TBRW. It is concluded that regional variation of HRY was affected by MRY, varietal variation by both MRY and PHR, and region-variety combined variation mainly by MRY.
In this paper, the full-size structural performance test for a lightweight soundproof tunnel composed of partitioned pipe truss members is carried out to investigate the structural performance. In addition, a nonlinear structural analysis of the same finite element model as the full-size testing model is performed to compare the test result. The test and analysis results showed that the lightweight soundproof tunnel ensures the structural safety against wind loads, snow loads and load combinations. As a result, the full-size test and analysis results m
본 논문에서는 범용유한요소해석 프로그램인 ABAQUS를 사용하여 국내에서 사용되는 콘크리트벽돌을 조적채움벽으로 가진 철근콘크리트 골조를 대상으로 유한요소해석을 실시하였다. 해석대상은 순수골조, 채움벽의 두께가 0.5B인 골조, 두께가 1.0B인 골조의 3종류이다. 철근콘크리트 골조 및 채움벽의 재료특성은 재료시험 결과로부터 구하였으나 두께가 1.0B인 채움벽의 경우 벽돌의 쌓기방법의 차이에 의해 0.5B 두께의 실험체보다 4배 정도 증가된 인장강도를 사용하였다. 유한요소해석결과는 실험을 통해 구한 하중-변위관계 및 변위각에 따른 균열양상을 상당히 정확하게 예측하였다. 유한요소해석 결과의 분석을 통해 조적채움벽과 골조사이의 접촉응력 및 골조의 전단력과 휨모멘트를 산정하였다.
This study analyzes the four composition elements : profile, anchorage and connection, material and member rigidity, stability, as the main composition design elements of flexure structure systems, in order to explore possibilities for more various structure designs in architectures with flexure structure system. It also examines typical design methods that use the mentioned four composition elements. At the results, this research presents an understanding of the differences between funicular shape and non-funicular shape and mechanical features of the shapes in the profile element, regarding to the ratio of rise height to span length(f/l). Also, the typical design methods are presented for the designable usages of the hinge joints and the fix joints, and for the applications of member rigidity expressed by the index of the ratio of member depth to span length(d/l). And it was presented that connection styles, addition of brace members, placement of shear walls are the main design methods in the stability element. This data would be useful to architectural designs concerning integrated design with structures.
This study investigated the correlation between consumer’s buying habits and food styling visual elements. Differentiated and original techniques were used to determine whether or not visual elements in tteok menus reflect the aesthetic needs of consumers without altering the nutrition of tteok. The targeted tteok cafes were in Jeonju Hanok Village, which is a tourist attraction in Korea. First, sub-factors of food styling visual elements applied to tteok café menus such as shape, size/volume, color, and texture all had significantly positive effects on customer satisfaction, proving that food styling visual effects applied to tteok café menus have significant effects on customer satisfaction. Second, sub-factors of food styling visual elements applied to tteok café menus all had significantly positive effects on buying habits. Third, customer satisfaction of menus had a significant effect on buying habits, as proven by previous studies. Fourth, the effects of customer satisfaction on the relationship between food styling visual factors applied to tteok café menus and buying habits were investigated.
This study investigated the preference of sensibility expression factors regarding fashion materials, such as the color, pattern and texture of fabric. Moreover, this study analyzed the relationship between the preference of sensibility expression factors and the preference of fashion images by identifying the preference of fashion images. The survey subjects were 312 women ranging in age from 20 to 40 years old. This study utilized a questionnaire as a measurement tool. First, this study performed a factorial analysis on the preference of sensibility expression factors of fashion materials. In regards to color preference, this study considered color depth such as light tone color, moderate tone color, dark tone color and vivid tone color. In regards to pattern preference, this study examined: geometric pattern, floral pattern, animal skins pattern, check pattern and symbolical pattern. In regard to preference of the texture, this study assessed: roughness, luster, flatness and lightness. Second, this study performed a factorial analysis on the preference of fashion images. This study examined five factors: dignity, uniqueness, femininity, activity and simplicity. Third, this study analyzed the effects of the preference of sensibility expression factors of fashion materials on the preference of fashion images. As a result, the color preference was related to the image preference associated with dignity, femininity and simplicity, whereas the pattern preference was related to the images of uniqueness, femininity, activity and simplicity. Moreover, the preference of texture image was related to the images of dignity, uniqueness, femininity and activity.
한국경제교육협회가 제시한 초등학생이 알아야 할 표준 경제 개념을 포괄적으로 포함하도록 총 3차시에 걸친 ‘원더랜드 만들기’ 프로그램을 개발하였다. 원더랜드 만들기 프로그램은 이미 개발되어 있는 ‘놀이공원 경제교육 프로그램’과 기본적으로 비슷한 철학과 구조를 가지고 있지 만 주어진 예산을 자신의 필요와 욕구에 따라 배분한다는 점, 예금과 대출의 역할을 하는 은 행을 포함한다는 점, 회계장부 사용을 통해 자신의 경제 활동 점검한다는 점 등이 추가되어 있다는 점에서 차이가 있다.
원더랜드 만들기 프로그램은 크게 활동 소개 및 가상계획 세우기, 원더랜드 숙소 설치하기, 세금 납부 및 순이익 계산하기 활동으로 구분된다. 첫 차시인 원더랜드 만들기 활동 소개 및 가상계획 세우기에서는 원더랜드를 소개하고 본 활동에서 사용할 화폐의 단위를 정한다. 또한 자신이 세울 시설물의 비용과 예산을 고려하여 대출 또는 예금 활동을 선택하고 마지막으로 예산 안에서 시설물을 설치한다. 두 번째 차시인 원더랜드 숙소 설치하기 활동에서는 의사결정 표를 만들어 4가지 시설물 중 어떤 종류의 숙소를 세울지 결정하고 이를 통해 기회비용의 의 미를 이해한다. 그 후 시설물을 설치할 때 사용한 비용과 수요표를 확인하여 숙소를 통해 얻 은 매출을 계산한다. 마지막 3차시에서는 세금 납부 및 순이익 계산하는 것이 주요 활동이다. 시설물의 매출을 계산하고 이윤에 대해 세금을 납부한다. 또한 1차시 때 예금한 돈을 찾고 대 출한 돈을 갚으며 최종적으로 순이익(매출-비용)을 계산한다.
원더랜드 만들기 프로그램의 효과를 검증하기 위하여 인천시 연수구에 위치한 6학년 8개 반을 대상으로 경제 지식 및 태도에 대한 사전 검사를 실시했다. 원더랜드 만들기 프로그램을 적용한 후 경제지식 및 태도 검사지 분석을 통해 두 영역 모두 유의미하게 향상되었음을 확인할 수 있었다.
본 논문에서는 유한요소법을 이용하여 공동주택의 중량충격음을 예측하기 위해 구조해석 모델과 음향해석 모델을 개발하고 예측결과와 실험결과를 비교하여 정확성을 검증하였다. 패널 임피던스 값을 사용하여 거실의 적절한 흡음 특성을 반영할 수 있었으며, 수치해석에 주파수 응답함수 특성을 적용하여 1회 수치해석만으로 다양한 충격원에 대한 응답을 예측할 수 있도록 하였다. 구조진동에 의한 실내 소음해석은 유한요소 수치해석 기법이 진동 및 음향모드에 대한 응답을 비교적 정확하게 예측할 수 있도록 하였으며, 본 연구의 예측결과는 실험결과와 비교적 유사한 값을 나타내었다. 향후 정확도가 보다 향상된 수치해석 모델개발을 통해 바닥충격음 저감에 효과적인 공동주택 설계가 가능할 것으로 판단된다.
모던시의 특징 중의 하나는 서사 형태를 사용하고 있다는 점이다. 이는 모던시인들이 가장 높고 고귀한 형식의 시로 꼽는 서사시를 그들의 시대에 되살리려 했다는 사실을 입증한다. 그리고 학자들은 이 예로 에즈라 파운드의 캔토스와 티에 스 엘리엇의 황무지를 꼽는다. 나는 윌리엄 버틀러 예이츠도 이 모던시인의 그룹에 속해야 한다고 믿는다. 예이츠는 비록 캔토스나 황무지에 비견될만한 서사형태의 시를 쓰지는 않았지만 그가 쓴 많은 시들이 서사시의 요소를 갖고 있기 때문이다. 이 는 예이츠 역시 파운드나 엘리엇처럼 전통을 존중하고 그 전통에서 시적영감을 얻을 뿐만 아니라 시적 연속성을 지켜야 한다고 믿었기 때문이다.
This study aims to empirically analyze the relationship between climate change elements and catch amount of coastal fisheries, which is predicted to be vulnerable to climate change since its business scale is too small and fishing ground is limited. Using panel data from 1974 to 2013 by region, we tested the relationship between the sea temperature, salinity and the coastal fisheries production. A spatial panel model was applied in order to reflect the spatial dependence of the ocean. The results indicated that while the upper(0-20m) sea temperature and salinity have no significant influence on the coastal fisheries production, the lower(30-50m) sea temperature has significant positive effects on it and, by extension, on the neighboring areas’s production. Therefore, with sea temperature forecast data derived from climate change scenarios, it is expected that these results can be used to assess the future vulnerability to the climate change.
본 연구의 목적은 TV산업에서 지배적 디지털 TV에 영향을 미치는 지배적 디 자인 결정요인과 제품핵심요소를 규명하는 것이다. 이를 위하여, 전문가 설문조사를 통해 자 료를 수집하고, 구조방정식 모형을 이용하여 분석하였다. 연구 결과, 지배적 디자인의 결정요 인은 디스플레이, 디자인, 특성에 영향을 주고 디스플레이와 디자인이 지배적 디지털 TV를 만드는 데 영향을 주는 것으로 밝혀졌다. 본 연구는 우리나라 TV기업이 지속적으로 지배적 디자인을 선도하여 선도자로서의 역할을 유지토록 사업전략 수립의 기초자료로써 큰 의미가 있다 하겠다.
Shim, Young-sook. 2015. “An analysis of ELF-oriented features in Korean middle school English textbooks”. The Sociolinguistic Journal of Korea 23(3). 147~176. This study examined how ELF-oriented features were incorporated into English textbooks used in Korean middle schools. A total of 213 dialogues and 214 reading texts presented in 21 textbooks were analyzed from the perspective of English as a global language. The analysis of the data revealed the following findings. First, most of the textbook dialogues took place between either English native speakers or an English native speaker and a Korean speaker, with the number of dialogues involving non-Korean ESL or EFL speakers remaining very low. Second, nearly all the audio-recordings of the dialogues and the reading texts presented American English accent regardless of the nationalities and cultural backgrounds of the speakers or narrators in the materials. Lastly, a considerable portion of the reading texts contained topics or situations that can potentially enhance learners' interculturality, though ELF-related issues were rarely addressed in the texts. Based on the findings, this paper suggested some implications for ELF-based English education in Korean context.
Various hybrid dampers have been developed in Korea to control the vibration due to a wind and earthquake. In order to minimize the installment space, cost and construction process, the new hybrid friction damper is developed. This hybrid damper is composed of several rotary friction components having two frictional joint. Because of these components, the building vibration due to wind and earthquake can be mitigated by hybrid friction damper. In this paper, various dependency tests were carried out to evaluate on the structural performance of two joint rotational friction component of the hybrid damper. Test results show that two joint rotational components do not depend on a displacement and a frequency of forcing but friction coefficients is reducing as a clamping force is increasing.
This study performed a finite element stress analysis of pipe system connected by bellows based on APDL(ANSYS Parametric Design Language) customizing. The effects of different shapes of developed pipes for various parameters are studied using the finite element commercial package for this study. The structural behavior of complex pipe structures with bellows was also investigated to study the interactions between bellows and other parts. Based on the ANSYS APDL, the effect of initial axial and lateral displacements, and internal temperature and pressure on the Von Mises stress distribution is also analyzed.
본 연구는 지하철 입구 공공공간에서 피험자의 선택적 주의집중 분석을 위한 공간요소별 주시데이터 추출이다. 주시데이터의 추출방법 연구 결과는 다음과 같다. 첫째, 눈을 통해 획득되는 시각정보의 특성을 분석하는 과정에 중심와의 반경을 이용하여 주시범위를 설정하는 방식은 기존의 시지각 이론을 근간에 두면서 선택적 주의집중에 해 당하는 주시데이터의 추출 결과를 객관화시킬 수 있는 방법을 정리했다. 둘째, 주시데이터 추출방법으로 기존에는 격자에 의한 빈도 분석이 주를 이루었는데 세부적 특성으로 공간정보를 분석함에 한계를 가지고 있었다. 이에 비해 선택적 주의집중 정도를 알 수 있는 주시데이터 추출방법은 공간에서 특정 요소에 시선이 얼마만큼 집중되는지를 분석해 낼 수 있었다. 선택적 주의집중을 통해 공간사용자의 주시특성을 분석하게 되면, 요소 맞춤형 주시데이터 추출이 가능하고, 이를 공간디자인이나 사인 배치에 활용하고 성과를 검증하는 것도 가능하다. 셋째, 공간요소에 대 한 시간범위별 분석을 통해 특정 공간 요소를 주시한 데이터 특성을 시계열적으로 추적하여 정리하는 것이 가능했는 데, 본 연구에서 대상으로 삼은 「해당 공간범위」의 결과를 보면, 남녀 모두 2분을 지난 시점에서 주의집중 정도가 급격히 떨어진 것을 확인할 수 있었다. 넷째, 주시 우위빈도를 통해 선택적 주의집중이 일어난 구역을 시간범위별로 분석하였는데, 성별에 따라 남자는 Ⅰ시간범위(52.4 %), 여자는 Ⅳ시간범위(24.0 %)에서 강한 주시가 이루어진 특 성이 있어, 성별 차이가 나타난 것을 확인할 수 있었다. 즉, 성별에 따라 선택적 주의집중이 일어나는 시간범위가 서로 다르다는 것에서부터 성별 차이를 향후 피험자 특성으로 설정하여 실험하고 분석하는 것이 필요하다.