• Geomechanics and Engineering
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• v.14 no.3
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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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• v.7 no.2
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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.

• Journal of Korean Society of Rural Planning
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• v.23 no.3
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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.

• Journal of Korean Home Economics Education Association
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• v.3 no.1
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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.

• Journal of Korean Home Economics Education Association
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• v.1 no.1
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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.

• Journal of Korean Society of Forest Science
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• v.102 no.2
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• pp.281-291
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• 2013

This study is design to provide basic directions that Korea can take in forestry negotiation of Korea- Vietnam FTA. Trade trends and characteristics of forestry sector are figured out and the competitiveness of main products are analyzed. The trade amount between Korea and Vietnam is $207,260 thousand. Korea exports nontimber products to Vietnam, while she mainly imports wood products. The average import value of wood products during recent five years accounts for 88% of all value from Vietnam. The export items are not various, and the export value is small. The amount of imports, however, which are mainly composed of low price wood products, is relatively big. The results of analysis say that three items of Korean forest products have competitiveness, while Vietnam has eleven items. According to the study it is recommended that a sawn wood and a plywood should be classified as sensitive products to minimize and to take a long term tariff reduction.

• Journal of the Korean Home Economics Association
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• v.47 no.10
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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.

• Journal of the Korean Institute of Gas
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• v.21 no.6
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• pp.61-69
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• 2017

In case of plant accident, the most important measures that field operators, control-room operators and fire fighters must take are the escape from and going into the accident sites. These two different actions are reverse directional moving actions. By training operators and fire fighters with counter-accident path taking measurements, we can prevent the small accidents from becoming large-scale accidents, and can take efficient measurements in case of actual plant accidents. Out of necessities of path-taking training, in this research, we developed the escape and rescue path-taking method for plant accident response training. We can calculate the escape and rescue routes from a operator or fire fighter's current location as of accident happening and provide route data which in turn can be used as the safety training scenario. We expect this path-taking method can enhance the effectiveness and reality of escape and rescue training scenarios.

• Journal of the Korean School Mathematics Society
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• v.18 no.1
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• pp.39-60
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• 2015

It is one of the fundamental issues that students in teaching and learning process should take a proactive role in school mathematics. Inquiry or discovery learning in school mathematics is the specific method for students to participate in lessons on their own initiative, which is supported by many scholars in mathematics education. In this paper, we investigate pre-service teachers' perspectives of Inquiry or discovery learning by intensively analyzing information and guided orientation in teaching practice. From this, we find the direction of the pre-service teacher training program for carrying out pre-service teachers' role to help students to take a proactive role in school mathematics.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.6
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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.