• Journal of Korean Society of Coastal and Ocean Engineers
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• v.24 no.2
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• pp.138-148
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• 2012

A stochastic reliability analysis model has been developed for evaluating the time-dependent stability performance of armor units of rubble-mound breakwaters subjected to the multiple loads of arbitrary magnitudes which could be occurred randomly. The initial structural capacities and the damage rates of armor units of rubble-mound breakwaters could be estimated as a function of the incident wave height with a given return period by using the modified Hudson's formula and Melby's formula. The structural stability performances of armor units of rubble-mound breakwaters could be analyzed in detail through the lifetime reliability investigations according to the limit states such as the serviceability or ultimate limit state and the conditions of multiple loads. Finally, repair intervals for the structural management of armor units of rubble-mound breakwaters could quantitatively be evaluated by a new approach suggested in this paper that has been based on the target probability for repair and the accumulated probabilities of failure obtained from the present stochastic reliability analysis model.

• School Mathematics
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• v.19 no.2
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• pp.385-403
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• 2017

This paper analyzed the units of capacity and weight in the mathematics textbooks in terms of units, relationship between the units, and the need of standard units. The results of this study showed that there were differences in the representation of the units, the notation of units, the types of units, and the representation of basic amount of units in the mathematics textbooks developed by the 5th, 6th, 7th, 2007 revised, and 2009 revised national mathematics curriculum respectively. The mathematics textbook developed by the 2009 revised mathematics curriculum was found to be generally consistent with the International System of Units (SI). However, the way of defining 1kg through the weight of water was found to be different from the SI. The relationship between the units was consistently described only with a written sentence in the previous mathematics textbooks, but the 2009 revised mathematics textbook presents questions and pictures to foster students' understanding of the relationship. Finally, activities and questions are required for students to recognize the universality and convenience of the standard units through the inconvenience of arbitrary units. Based on these results, this paper provides implications for the development of mathematics textbooks in the units of capacity and weight.

• Journal of The Korea Institute of Healthcare Architecture
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• v.10 no.2
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• pp.39-49
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• 2004

With its rapid modernization and unparalleled speed of aging, South Korea faces the need for dramatic increase in its supply of nursing homes. Among the spacial components of nursing homes, residential units are considered as an essential part because the older person in nursing homes usually spend most of their time in residential units and the nursing homes are mainly composed of various residential units. It is necessary, therefore, to prepare a guideline for the plan of residential units in order to design the healthy and efficient nursing homes. This paper has first identified the concept of residential unit and analyzed 66 cases in the 62 nursing homes from 4 countries. And 4 nursing homes in Korea have been surveyed for the in-depth study. On the basis of this analysis, architectural prototypes of residential units have been proposed and the architectural characteristics of them have been compared analytically.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2004.05a
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• pp.66-70
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• 2004

With its rapid modernization and the unparalleled rate at which its society is aging, South Korea faces the need for a dramatic increase in its supply of nursing homes. Among the spacial components of nursing homes, residential units are considered as an essential part because the older person in nursing homes usually spend most of their time in residential units and the nursing homes are mainly composed of various residential units. It is necessary, therefore, to prepare a guideline for the plan of residential units in order to design the healthy and efficient nursing homes. This paper has first identified the concept of residential unit and analyzed 55 cases in the 51 nursing homes from 4 countries. On the basis of this analysis, architectural prototypes of residential units have been proposed and the architectural characteristics of them have been compared analytically.

• Journal of The Korean Association For Science Education
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• v.18 no.4
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• pp.539-544
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• 1998

The consistency and balance of objectives by objective domains in units, sub-units and instructional units were investigated. The 6th elementary biology curricular teaching guidebooks were analysed. Domains of objectives are cognitive, inquiry process, instrumental skill, creative, affective and STS. Cognitive objectives were most dominant in all units, sub-units and instructional units. But no objective for creative domain were suggested. In unit and sub-unit, proportions of objectives were cognitive, inquiry process, affective, instrumental skill and STS domains in order. Objectives for cognitive and inquiry process domains were more than others in instructional units, Except cognitive and inquiry process domains, objectives for the others were not consistent in all units, sub-units and instructional units. Especially, the percentages of objectives for affective domain decreased in units, sub-units and instructional units orderly. These resulted from teaching objective domains categorized formally, Thus, it is necessary to develope curriculum and textbook to be consistent and balanced with objective domains and reflect upon the characteristics of them.

• Journal of Korean Elementary Science Education
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• v.26 no.5
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• pp.551-557
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• 2007

The purpose of this study was to examine the questions in the 'Matter' units of elementary science textbooks under the 7th curriculum. For the analysis, a total of 338 questions were extracted from 15 units. Six criteria (recalling, recognizing, predictive, applied, divergent, and evaluative question) were reconstructed for textbook question analysis based on Blosser(1973)'s question category system for science. The results were as follows. First, there were more closed (recalling, recognizing, predictive, or applied) questions (72.2%) than open (divergent or evaluative) questions (27.8%) in elementary science textbooks. Second, cognitive-memory (recalling or recognizing) question type was the most frequently asked in all grade levels. Open (divergent or evaluative) questions increased according to grade level whereas convergent (predictive or applied) questions decreased. Third, question types were applied based on the characteristics of each unit rather than on children's developmental characteristics. Educational implications were discussed based on the results.

• Journal of Korean Elementary Science Education
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• v.27 no.4
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• pp.420-436
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• 2008

The purpose of this study was to investigate and analysis the elementary teachers' and students' views about the difficulties in teaching and learning in geology units of elementary school science. For the purpose of this study, semi-structured interviews were conducted individually with seventeen elementary teachers who have serviced more than three years, and with sixteen elementary students located in Cheongju City. The interview questions were developed through Seidman's step to acquire a reliability in the interview data with triangulation, then in-depth interview questions were modified and completed through pre-interview after constructing the trustworthiness of interviewees. In-depth interviews were performed in applying the analytic induction method and the interviews were recorded. From the interviews, we found that elementary teachers' views about the difficulties in teaching geology units; teachers' inner difficulties, the difficulty of lab activities, the problems of rock samples, the problems of curriculum in geology units, the difficulty of the geological feature, the problems of the cramming education, the lack of the opportunity for the speciality, and so on. And the students have the views about the difficulties in learning geology units; the difficulty of the unit contents understanding, the problems of learning by heart, the lack of the interest, the lack of materials, the problems of rock samples, the difficulty of the field learning, and so on. Based on the results, the study suggested that an interesting lab activities should be included in the geology units and taught in the geological field trip to help elementary school students more fully comprehend contents of the geology units.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.381-382
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• 2007

• Computers and Concrete
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• v.23 no.2
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• pp.97-106
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• 2019

This paper describes the design of a new interlocking masonry system, the production of designed interlocking units and mechanical properties of interlocked masonry assemblages with mortar. In this proposed system, units have horizontal and vertical locks to integrate the units to the wall and have a channel to enable the use of horizontal reinforcements in the wall. Using these units, unfilled, filled or reinforced walls can be constructed with or without mortar. In the production of the interlocking units, it was decided to use foamed concrete. 12 trial productions have been carried out at different mix proportions to obtain the optimum concrete mix. At the end of the mentioned productions, the units were produced with foam concrete which is selected as the most suitable in terms of compressive strength and specific gravity. Then, axial compression, diagonal tension and bed joint shear tests were carried out to determine the mechanical properties of the interlocked masonry assemblages with mortar. Results from the tests showed that interlocks designed to strengthen the system against shear stresses by creating discontinuity throughout the joints have been successful to achieve their aim. Obtained data will enable structural analysis of walls to be constructed with these new units.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.2
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• pp.83-90
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• 2018

This study was conducted to investigate the living environment of semi-basement housing units in multi-household houses. It analyzed measurements of temperature and humidity obtained from the housing units. For this study, temperature and humidity sensors were installed in 10 semi-basement housing units to measure interior temperature and humidity for 13 months. A survey was conducted to get information about the occurrence of dew condensation and mildew and to investigate residents' satisfaction level with the residential environment. According to the result, all the housing units under study had dew condensation and mildew. The average summer temperature of the 10 housing units was $27.84^{\circ}C$, and average humidity was 64.91%RH, while the average winter temperature was $20.6^{\circ}C$, and the average humidity was 40.12%RH. Depending on the condition of each housing unit, deviation was big. Residents' average level of satisfaction with the living condition was 2.03 which shows a low satisfaction (on a scale of 1-5 with 5 being completely satisfied.).