• Geomechanics and Engineering
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• 제14권3호
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• pp.211-224
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• 2018

In this paper, a predictive method accounting for the scaling effects of rockfill materials in the numerical deformation analysis of rockfill dams is developed. It aims to take into consideration the differences of engineering properties of rockfill materials between in situ and laboratory conditions in the deformation analysis. The developed method is based on the modification of model parameters used in the chosen material model, which is, in this study, an elasto-plastic model with double yield surfaces, i.e., the modified Hardening Soil model. Datasets of experimental tests are collected from previous studies, and a new dataset of the Nam Ngum 2 dam project for investigating the scaling effects of rockfill materials, including particle size, particle gradation and density, is obtained. To quantitatively consider the influence of particle gradation, the coarse-to-fine content (C/F) concept is proposed in this study. The simple relations between the model parameters and particle size, C/F and density are formulated, which enable us to predict the mechanical properties of prototype materials from laboratory tests. Subsequently, a 3D finite element analysis of the Nam Ngum 2 concrete face slab rockfill dam at the end of the construction stage is carried out using two sets of model parameters (1) based on the laboratory tests and (2) in accordance with the proposed method. Comparisons of the computed results with dam monitoring data indicate that the proposed method can provide a simple but effective framework to take account of the scaling effect in dam deformation analysis.

• Journal of Communications and Networks
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• 제7권2호
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• pp.115-125
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• 2005

This paper discusses how to effectively design a next-generation wireless communication system that can possibly provide very high data-rate transmissions and versatile quality services. In order to accommodate the sophisticated user requirements and diversified user environments of the next-generation systems, it should be designed to take an efficient and flexible structure for multiple access and resource allocation. In addition, the design should be optimized for cost-effective usage of resources and for efficient operation in a multi-cell environment. As orthogonal frequency division multiple access (OFDMA) has turned out in recent researches to be one of the most promising multiple access techniques that can possibly meet all those requirements through efficient radio spectrum utilization, we take OFDMA as the basic framework in the next-generation wireless communications system design. So, in this paper, we focus on introducing an OFDMA-based downlink system design that employs the techniques of hybrid multiple access (HMA) and frequency group (FG) in conjunction with intra-frequency group averaging (IFGA). The HMA technique combines various multiple access schemes on the basis of OFDMA system, adopting the multiple access scheme that best fits to the given user condition in terms of mobility, service, and environment. The FG concept and IFGA technique help to reduce the feedback overhead of OFDMA system and the other-cell interference (OCI) problem by grouping the sub-carriers based on coherence band-widths and by harmonizing the channel condition and OCI of the grouped sub-carriers.

• 농촌계획
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• 제23권3호
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• pp.83-96
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• 2017

This study aims to contemplate the archetypal landscape of a scenic site, Suseungdae area in Hwangsan-maeul village, Geochang-gun by reference research and field surveys and drew the results as follows. First, Since Seong Yundong(成允仝; 1450-1540) embarked on operating the Suseungdae in Eonari(魚川) in 16th century, Shin Gwon(愼權, 1501-1573) and Im Hun(林薰, 1500-1584) took a major role of establishing the archetypal landscape of the area. Henceforth, numerous scholars had kept exploring the scenery and completing the archetypal landscape of the area until the 19th century. Second, the locations of 50 archetypal landscape elements, including "Guyeon-dong sipgugyeong(龜淵洞十九景)" which are dispersed along the Wicheon, has been identified. On the base of this, the archetypal landscape of Suseungdae area is figured out as the 'Guyeon-dong(龜淵洞)' area coming down from 'Cheoksuam(滌愁巖)' to 'Byeoram(鼈巖)'. Third, many archetypal landscape elements are from the locations along the river. Among them, the ones named with rock: Am(巖) and Seok(石), which are shapes of turtles or terrapins, take the high rate and so do the ones named with 'Dam(潭)', which are waterscape. Fourth, among the cultural landscape elements, there are many garden structures such as Nujeong(樓亭) and Seowon(書院), which are located at the spots of viewing the landscape and the structures like banks, bridges and dams are also included. Furthermore, the letters engraved on the rocks are mainly about the landscape elements and are sometimes about the records of building and operating the landscapes by the people who were appreciating the arts and nature. Based on the range and characteristics of the archetypal landscape in Suseungdae area from this study, it is needed to take follow-up studies on the guidelines for efficient management by means of classifying the detailed fields so that there are no negative factors conflicting with the adjacent land use.

• 한국가정과교육학회지
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• 제3권1호
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• pp.49-59
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• 1991

The purpose of this study is to find out the influence of Home Economics learning on the recognition and attitude of middle school boy’s home life and to suggest the basic materials for the development of the Home Economics education through students’opinion of Home Economics. For this purpose, a survey was conducted in Cheong-ju area using questionaire. The subjects were 487 boys who studied Home Economics (HE group)and 480 boys who studied Technique (T group) in middle school. The statistics used for data analysis were t-test and x$^2$-test. The results of this study were as follows： 1. The recognition and attitude to home life on the general characteristics of home life； In urban area, the interests in bealth and the role of the consumers were higher than those of rural areas-on the bases of the standard of life, the middle class students had a higher interest in nutrition and food habits, the students whose father were engaged in special job had a higher interest in health and nutrition. 2. The difference of the recognition and attitude between HE & groups； In the field of food life, HE’s knowledge about the six nutrients and the basic food groups and attitude toward buying food were higher than T’s. In the field of family life and resources, HE and T accepted the importance of family life and the role of home as important, hoped to get psychological relax from home and to take the right sexual education. In the field of clothes life, HE and T had the general tendency to have their clothes in proper manner and to select their clothes for themselves, but HE took a higher interest in clothes mending and the role of clothes. 3. The opinions on Home Economics； HE answered that Home Economics was useful to them (more than 90% of HE) and that 57.1% of HE were interested in Home Economics. The order of interest among three fields were as follows： food life, clothes life, family life and resources. 71.9% of T hoped to take Home Economics course.

• 한국가정과교육학회지
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• 제1권1호
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• pp.63-85
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• 1989

The Change of environment related to human life, science, technology, economics and education level have much effect on home life. Therefore Home Economics Education have to get out of past trite concept that it is only a method to become good housewife and take the role to widen the human life and to grow creative power as a academic part of science. For these, Home Economics should become life education, life education of secondary school has to have relation to lifelong education. To achieve effective result from Home Economics Education, the object, system and methods of Home Economics Education, the object, system and methods of Home Economics Education have to be improved and teaching material has to be studied systematically. As an object of aboves and education planning in clothing is made for deep understanding the study of Home Economics Teaching Material. And to understand the real state, made some questions, had interview with 63-teaching in Kangweon province and show the results. 1) Tab 1~20 are the level of recognition about object, teaching content, time structure of secondary school. The object is recognized as cultural education and basic job education. 2) Tab 21~30 show the real state of textbook and study of it. To take effect from school lecture other teaching material except textbook is required. 3) Tab 31~40 are the result of sewing and handicraft practice. Sewing and handicraft needs much time and almost all time is used in practicing. 4) Tab 42~54 are the planning of textbook study for effective teaching, self-estimation and teaching material making is also considered. All above is collarless blouse’s planning. Base on above result, all objects of clothing life should be teached. For the development of Home Economics Education 1) Understanding and affection of teachers is required. 2) To solve indicated problem, national policy, education plan in school and education finance are fully supported. 3) More studies is required in Home Economics Education.

• 한국산림과학회지
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• 제102권2호
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• pp.281-291
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• 2013

이 연구는 한국과 베트남의 임산물 교역동향 및 교역의 특징을 살펴보고 주요품목의 경쟁력을 분석하여 한-베트남 FTA 임산물협상에 있어 한국이 취할 수 있는 방향을 제시하였다. 한-베트남 임산물 교역규모는 2011년 2억726만 달러에 달한다. 한국은 주로 베트남에 단기소득 임산물을 수출하고 있는 반면, 목재류를 수입하고 있다. 특히 최근 5년 평균 목재류 수입액은 한국의 대베트남 수입액 중 88%에 달하는 것으로 나타났다. 한-베트남 교역에 있어 수출 품목은 다양하지 않고 수출액은 적은 반면, 수입은 저부가가치 목제품을 위주로 대량 수입되고 있다. 한-베트남 임산물의 경쟁력 분석결과 한국의 임산물 중 경쟁력이 있는 품목은 3개 품목이나, 베트남은 11개 품목으로 나타났다. 교역구조 및 경쟁력 분석결과와 현행 관세율을 고려할 때 제재목, 합판 등을 민감품목으로 지정하여 관세인하를 최소화하고 관세인하 기간을 장기로 설정할 수 있는 방향으로 협상하도록 하여야할 것이다.

• 대한가정학회지
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• 제47권10호
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• pp.63-72
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• 2009

The purpose of this study was to investigate Korean elementary school children's extracurricular activities by gender, grade and area from a sample of 3,608 children in six Korean provincial areas except Jeju-do. They responded to the questionnaire developed by the researchers. Data were analyzed by frequency and percent using the SPSS PC 15.0 program. Results were as follows: Firstly, 3,337 children(92.5%) participated in extracurricular activities, and the rest(7.5%) did not. This result illustrates that the majority of Korean elementary school children are taking part in at least one or more out-of-school activities. Secondly, the average number of extracurricular activities in which elementary school children participated was 8.48 and the average time allotted was 655.24 minutes; each child took about 8 activities and spent approximately 10 hours per week. Thirdly, main extracurricular activities in which children participated were to go to educational institutes, to take art/physical education lessons, and to study self-learning materials. Lastly, what elementary school children wish to do most in their spare time was to play the computer games, to take a rest, to enjoy family and friend relationships, and to watch the television.

• 한국가스학회지
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• 제21권6호
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• pp.61-69
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• 2017

플랜트 사고 발생 시 현장 운전원, 제어실 운전원 및 소방관 등이 취해야 할 가장 중요한 사항은 사고 현장으로부터의 탈출과 사고 현장으로의 사고 진압 처리를 위한 진입일 것이다. 이 두 가지 중요한 행동은 서로 상반된 방향으로 진행해야 하는 조치이며, 사고 대응 이동 경로에 대한 훈련을 평상시에 훈련함으로써, 사고의 확산을 방지하고 효율적인 사고 대응을 할 수 있다. 이와 같은 필요성에 의해 본 연구에서는 플랜트 사고 대응 훈련을 위한 탈출 및 조치 경로 설계 기법을 개발하였다. 활용 방안으로는, 운전원 및 소방관들의 사고 발생 시점의 플랜트 내 실시간 위치로부터 사고 탈출 및 조치 경로를 계산하여 플랜트 안전훈련시스템에 이동 경로 정보를 제공함으로써, 안전 훈련 시나리오에 적용하여 현실적이고 효과적인 훈련 효과를 제공할 수 있을 것으로 기대된다.

• 한국학교수학회논문집
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• 제18권1호
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• pp.39-60
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• 2015

본 논문에서는 van Hiele의 단계적 교수법에 근거한 예비교사들의 수학 수업에서 학생들을 지식 구성의 주체로 만드는 탐구 활동의 활성화 방안을 탐색하고자 한다. 이를 위하여 예비교사들의 수업 지도안과 수업 시연에서 van Hiele의 단계적 교수법의 정보 단계와 안내된 탐구단계에서의 교수 학습 상황을 분석한다. 이와 같은 교수 학습 상황에서 탐구학습 또는 발견학습의 활성화 가능성을 탐색한다. 특히, 본 연구에서 삼각형의 외심과 내심을 두 도형의 위치관계라는 개념구조 안에서 삼각형과 원의 위치관계를 출발점으로 설정하는 방안을 제안하고 이 제안에 대한 구체적인 실행 방법으로서 "사실1: 삼각형의 외접원은 유일하게 존재한다."와 "사실2: 삼각형의 내접원은 유일하게 존재한다."는 두 가지 사실의 도입과 증명을 van Hiele의 단계적 교수법에 근거한 새로운 지도방법으로 제시하고자 한다.

• 수산해양교육연구
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• 제28권6호
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• pp.1561-1572
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• 2016

The ability to handle materials from one location to another, whether during transit or at the worksite is vital to all segments of industry. To varying degrees, many personnel in numerous workplaces take part in materials handling. Consequently, some employees are injured. In fact, rigging & slinging is a dangerous work using a crane and sling equipment to carry a cargo and the mishandling of materials is the single largest cause of accidents and injuries in the workplace. The majority of accidents associated with cranes and other lifting appliances are caused by faulty slinging, overloading, unbalanced loads, etc. which result in the load falling or tipping out of control, causing injury to people, damage to plant, machinery and the load. Therefore, recognizing the dangers of the works, there are much technical support including skill training in various institutes to minimize accidents during works on land. Although rigging work at sea is much dangerous than on land work because it needs to take account of the movements of the ships and waves, etc. in addition to land based rigging hazards, it is insufficient in appropriate actions that can improve the safety of the workers at sea. Therefore, this study suggested a rigging and slinging course for seafarers to improve their safety at sea by researching hazards and risk of rigging works and related skill training conducted on land.