• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.2
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• pp.69-74
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• 2016

Most hot water heating valves for apartments are constant-flow types, which limit the flow rate through an individual household for even distribution of heating water to other households. The constant-flow type is implemented by an on-off control. As a result, heating water is supplied intermittently and hence, indoor air temperature also fluctuates. Returning water temperature is also high, which reduces energy efficiency. To implement continuous feedback control, the indoor temperature dynamics was simulated to fit a measured temperature history by a state-of-the-art physical model. From the model, it was found that the most important disturbance is outdoor temperature and its effect on indoor temperature lasts about an hour. To cope with the slow response and the significant disturbance, a prediction control with proportional feedback is proposed. The control was found to be successful in implementing continuous heating water flow and improved indoor temperature control.

• The Journal of Korean Association of Computer Education
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• v.6 no.4
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• pp.195-207
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• 2003

The Seventh Curriculum uses not only individual assessment but also team assessment method that organizes and solves assignments by team unit. It also helps students to learn cooperation and responsibility and share the ideas and process of the team project with other students through class presentation. It is also cooperative learning which is performed by several students together. Therefore, the assessment of team project is required to synthetically assess the performance process not the itself. This thesis will examine the actual problems about team project assessment and analyze related literatures. Then, this study designs and implements a practical system which alleviates the burden of teachers in charge of a team project assessment and improves reliability and validity in assessing team projects through multilateral assessment aiming at process as well as result objectives.

• Journal of Korean Elementary Science Education
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• v.39 no.3
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• pp.412-432
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• 2020

The purpose of this study is to explore the characteristics and the level of fourth grade elementary students' system thinking when they learn the unit of "Journey of Water" in terms of four key elements of system thinking such as understanding of the structure of a system, non-linearity and cyclic features, inter-relations and feedback between system properties, and temporal and invisible aspects of a system. Data included students' worksheets and their responses to a set of Likert-scaled and written assessment items on water cycle. The results showed that the level of students' system thinking did not have any hierarchy in relation to the key elements of water cycle system. In addition, the aspects of individual student's system thinking on its sub-elements were different from each other. Also, there were core ideas of system thinking which were intensively considered according to a given context to understand a complex systemic subject. When students learn water cycle, understanding of non-linearity and inter-relations were weaker compared with other key elements of system thinking. Therefore, if these two factors are taught in advance, it can promote understanding of whole system of water cycle.

• Journal of Family Resource Management and Policy Review
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• v.12 no.4
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• pp.1-13
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• 2008

The purpose of this study is to analyze and assess the family policy of the Lee administration and to suggest agendas for sustainable future family policy. Traditionally, families are a unique unit of production and reproduction of family members and social laborers. In addition, families are the social safety net help people survive in a society. Therefore, family policies play an important role in contemporary society. In this context, we review the literature related to family and social policy, and the contents of Ministry for Health, Welfare and Family Affairs, which is the main authority in Korea. The results are as follow: Firstly, the Lee administration ignored the data showing that family policy should be a unique policy, and not a sub-division of welfare policy. Secondly, there is no difference between the active welfare policy of the Lee administration and policies of past administrations. Finally, this study suggests that subjects of future oriented family policy should focus on co-developing programs for the individual, family, and society, to develop problem-prevention and family needs- ordered policy, and to make integrated family policy through laws and delivery systems such as Healthy Family Centers.

• Journal of the Korean housing association
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• v.22 no.2
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• pp.101-109
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• 2011

Until now, several comparative approaches were developed within the studies of Korean, Chinese, and Japanese traditional housings. In those studies, however, each space in the traditional houses was only treated in individual and fragmentary manners, and they lacked the interpretation of the topological attribute of each space within a holistic structure organized by unit spaces, and of the cultural-behavioral meaning of them within a holistic space-use pattern of the housing. The topological attribute and behavioral meaning can be analyzed and interpreted with the quantitative spatial analysis method such as Space Syntax. This study aims to analyze the traditional housings in Korea, China and Japan in the holistic aspect of spatial structure using Space Syntax, and to compare the analysis results with relating the structural attributes to the space-use pattern. In this study, the 'Banga' in Chosun era, the 'Siheyuan' in Ming-Ching era, and the 'Shoinzukuri' in Edo era were selected as the analysis subjects. The integration indices were calculated from the convex maps representing the subjects, and the common and different attributes of the three subjects were defined through comparative analyses.

• Journal of Korean Institute of Industrial Engineers
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• v.28 no.4
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• pp.415-424
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• 2002

Semiconductor manufacturing has been emerged as a highly competitive but profitable business. Accordingly it becomes very important for semiconductor manufacturing companies to meet customer demands at the right time, in order to keep the leading edge in the world market. However, due-date oriented production is very difficult task because of the complex job flows with highly resource conflicts in fabrication shop called FAB. Due to its cyclic manufacturing feature of products, to be completed, a semiconductor product is processed repeatedly as many times as the number of the product manufacturing cycles in FAB, and FAB processes of individual manufacturing cycles are composed with similar but not identical unit processes. In this paper, we propose a production scheduling and control scheme that is designed specifically for semiconductor scheduling environment (FAB). The proposed scheme consists of three modules: simulation module, cycle due-date estimation module, and dispatching module. The fundamental idea of the scheduler is to introduce the due-date for each cycle of job, with which the complex job flows in FAB can be controlled through a simple scheduling rule such as the minimum slack rule, such that the customer due-dates are maximally satisfied. Through detailed simulation, the performance of a cycle due-date based scheduler has been verified.

• Journal of Agricultural Extension & Community Development
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• v.23 no.2
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• pp.145-156
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• 2016

The purpose of this study is to analyze the farms growing domestic kiwi fruit 'Gold' on their management performance and efficiency in order to reduce the risks involved with introducing new kind of crops for growing, and suggest improvements. First, the result of analysis showed that domestic kiwi fruit 'Gold' growers' income were higher than the average growers due to the fruit's high unit price and productivity. Second, the analysis of management efficiency resulted in scale efficiency having greater impact on inefficiency rather than pure technical efficiency. As for the analysis of technical efficiency, the depreciation costs of agricultural facilities had the greatest influence on its inefficiency. Third, inefficient farms put in excessive inputs across the board, while labor costs(self labor cost + hired labor cost) were the largest factor of optimal inputs according to the models of technical efficiency and pure technical efficiency. Fourth, because of greater reliance on mechanical tools from rising labor costs, there's a need for individual farms to avoid buying farming equipments and instead share the equipments of nearby farms and agricultural cooperatives, or start renting agricultural machines from companies.

• Journal of Digital Contents Society
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• v.8 no.4
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• pp.615-622
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• 2007

A game engine should have the architecture that can manage various interactions between entities in a game for offering users various game experience. For this purpose, the game engine architecture based on message system is used. But only by this message based system, it is difficult to change game world continuously according to some storylines. The reason of this is event-driven system like message based system is appropriate for processing individual message but is not appropriate for processing more bigger logical work unit. For this purpose this paper proposes the storyline entity. The storyline entity has logical flows for a storyline and is called by engine continuously. By this proposed game engine architecture he or she can maintain free game experience by message based system and can add some progressing of storylines.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.141-142
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• 2017

New waterproofing technologies have emerged in the field of building waterproofing due to the recent diversification of the size and type of structures, the enhancement of required performance, and the diversification of new technologies (such as materials and methods)(Sheet waterproofing material, coating waterproofing material) is reduced, and composite waterproofing materials that utilize mutual benefits are widely used by compounding them (sheet+coating film, coating film+sheet). However, it is true that there is no evaluation method that can verify these composite waterproof materials, which is the most widely used at present, but the KS standard only specifies tests for individual materials However, there is a situation in which the countermeasures without a test method for composite waterproofing become sudden.

• Journal of the Korean Institute of Landscape Architecture
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• v.25 no.2
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• pp.73-81
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• 1997

The main purpose of this study was to develop a new method for evaluation of stream naturalness in order to appraise and prescribe for streams effectively in the process of ecological restoration of stream corridors. The results are as follows : 1) For this purpose six factors were selected on considering the spatial axes of stream corridor variation and total 20 descriptors about the physical structure were selected. 2) The calculation of S.N.I. for each segment was consisted of three steps, such as calculation of S.N.I.s of the individual descriptors, averaging all the descriptors's for each factor, and finally averaging the factors's for the Total S.N.I. 3) The evaluation unit was decided to be 100m size. The score system ranging 1~5 was adopted. Weighting parameters of factors were unified with each other. 4) A GIS model was adopted for classification, calculation, querying, analysing, and presenting S.N.I. information. And the format of S.N.I. maps including statistical graphs and other spatial watershed information was designed for the GIS odel. The naturalness of stream corridor was was investigated by the naturalness of habitat, and assessed by the descriptors focused on physical structure, therefore the S.N.I. can manifest prescriptions for restoration of the stream corridor. On the other hand because some evaluation factors such as water quality, water volume, fauna, flora, functions of stream exosystem has been excluded, S.N.I. could have some limits on representing the full aspects of stream naturalness. This evaluation method is hypothetical one, so it would be investigated through iterative applicatons.