• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.1
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• pp.40-47
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• 2009

This paper presents the method of measuring the feedback interference channel, which is developed between the transmit and receive antennas of a wireless repeater by receiving the transmit signal at the receive antenna of the identical repeater, and experiment results obtained by analyzing the measurements. This experiment uses 2 GHz WCDMA signal and is carried out near a highway. The high-speed mobiles on highways cause reflected signals with high Doppler frequencies and large energy. In order to characterize the feedback channel, the power delay profile and the scattering function are estimated by identifying the delay spread, the Doppler spread, the number of fingers, and the attenuation with delay. Since the feedback interference channel is constructed between the fixed TX and RX antennas, which is dependent upon the multipaths developed by moving or fixed objects around the antennas, the channel shows different properties comparing to the conventional channels between the base station and the mobile station. Therefore, the results presented in the paper are expected to provide guidelines for designing and evaluating wireless repeater systems.

• Journal of the Korean Society of Earth Science Education
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• v.4 no.3
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• pp.278-296
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• 2011

The purpose of this study is to examine the pedagogical content knowledge (PCK) elements and the changes in the science lesson planning and implementation difficulties experienced by high-career elementary school teachers with over 20 years of educational experience through the instructional consulting case of the Seoul City Office of Education Scholarship Support Group in order to find implications on effective instructional consulting support plan for improving the science teaching professionalism of high-career elementary school teachers. The result of this study is as follows : First, the pedagogical content knowledge (PCK) elements on the science lesson planning and implementation difficulties experienced by high-career elementary school teachers with over 20 years of educational experience were related to teaching strategy and they experienced difficulties in lesson content organization using lesson model and experiment facilitation and questioning, as well as in the area of interest and motive management that are definitional characteristic of learner in the learner element. Second, as for the changes in the PCK through science instructional consulting, they recognized the importance of the designing and experimenting process as students become the subject in the experiment facilitation in lesson, and they ended up attempting the postscript for promoting the thinking power of students. In addition, it was found that not only the cognitive characteristic but also the definitional characteristic of learner is important in science lesson and that students' motive is also an element that needs to be continuously managed. Third, as for effective instructional consulting plan for enhancing the science teaching professionalism of high-career elementary school teachers, it was revealed that it is necessary to first develop lesson expertise improvement consulting program that takes into account of teaching profession advancement phase of high-career teachers, and establish instructional consulting system and human resource pool of high-quality consultants based on the administrative and financial support from the Office of Education. The academic significance of this study is in the fact that it examined and searched for support plan on science teaching professionalism of high-career elementary school teacher, but a more extensive and in-depth study is needed since there is a limitation in this study on the object of study and the period.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.5
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• pp.442-448
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• 1999

We introduce the systematization design method using similarity theory which is profitable in the c compatability and standardization of the developed products and the reduction of construction time and price to d develop and design a machine equipment. Systematization design method is to select the standard model for d designing and developing from the large machinery to the super precision one and then to induce the c characteristic of machines step by step in advance in case of miniaturizing and making largelongleftarrowscale. With this m method, we extract the peculiar characteristics through the close analysis on the physical and ttx:hnical part a and predict the characteristic experiment for the magnitude we desire by an머ogical mathematical analysis. At l last, we will get the design sample the users demand with the verification of the data on optimum design p previously. In this paper, we could predict the characteristic of the product the users rC'Quire in advance with the d design method applying similarity theor${\gamma}$ and suggested the design method which could meet the various r requirements the users want. Also, it is shown that the standardization design by the similarity theory is a available as comparing the characteristic values expc'Cted through the experiment of the actual actuator with t the theoretical character data of similarity theoη after selecting the linear actuator as a model.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.2
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• pp.73-88
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• 2000

A series of analysis and experiment on the fishing gear and method of the existing midwater pair trawl net with 12,800mm of maximum mesh size is carried out to determine the most effective shape factor. As the first step of this study, the fishing gear and method for the existing net are analyzed to solve problems, such as being low of the net height by increasing the towing speed, twist of net pendant and twine, suspension of float between knots of mesh. etc. Standing on these results, the existing net are modified by very effective shape based on the theory and technology designing the fishing gear. Also, the model experiment is carried out to determine the most effective shape factor of the modified net in the circulation water channel. The obtained results can be summarized as follows : 1. On the length of net pendants(No.2 and No.3) connected with side line, opening efficiency of net with length 8.0cm of net pendant is the greatest and in the order of 11.5cm, 15.0cm. 2. On the number of the net pendant, opening efficiency of net with 4 lines of net pendant is the greatest and in the order of 3 lines, 2 lines. Center part of side panel is pushed out backward, and the pushed length is increasing by increasing flow speed. 3. On the sinking force, opening efficiency of the net is increasing by increasing sinking force. And opening efficiency shows almost the same when sinking force is greater about 1.5 times than that of the existing net in case of the net with 3 lines of net pendant, and about 1.6 ~ 1.7 times than that of the existing net in case of the net with 2 lines.

• Science of Emotion and Sensibility
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• v.10 no.1
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• pp.87-98
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• 2007

The aim of this study is to grasp the features of the object which reveals its own specific purposes, and to apply them to the product concept and design forms when designers develop products. For this study, the subjects of the experiment were chosen to fill out a basic questionnaire, and an image analysis of them was performed. After the analysis, the functional design elements of the subjects were extracted and coded. They preyed the correlation between the results of the image analysis and the characteristics of the subjects. The questionnaire was carried out to determine the characteristics of the subjects. As the features of specific products were extracted through this experiment, they can be used as basic data to analyze consumer needs and to better understand the products when we design for them. This can be useful fundamental data enabling designers to understand products easily and to establish concepts for their designs. In the case of the MP3 player in this study, the results of the image analysis of it are turned out to be sound quality, compatibility, portability, employment, interface, and personality. Their respective related features were investigated as well. The important features of designing the MP3 player were presented. Through this fundamental study, it will be possible to understand consumer's needs more effectively, which will bring about the development of the fundamental basis of various fields in design.

• Science of Emotion and Sensibility
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• v.13 no.4
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• pp.677-686
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• 2010

This study intends to provide the data to extract the elements that influence users' preference from "setting-up," a Traditional craft skills, and apply it to design and use it, so as succeed to the traditional values by connecting the Traditional craft skills with design and to establish a design-supporting system that can meet contemporary users' desire. In this light, this study, as a basic research, selects a sense of beauty and functional quality as a standard for applying setting-up to design and conducts an experiment to extract the elements of design that are important in setting-up. An analysis of factors based on the experiment reveals that in terms of a sense of beauty and functional quality, typical quality, creativity, historicalness, productivity, safeness are derived as elements that influence setting-up. And an analysis of meaningfulness tells that each element of Panjac Setting-up and Yeongui Setting-up is the most meaningful. This result shows that it is important to know the relationship with elements extracted as emotional elements, which can be useful as an index for establishing a design-supporting system that can serve as a guideline in designing through applying to design.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.2
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• pp.153-158
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• 2011

This paper presents subjective experimental results to understand how audio should be changed when a video clip is watched in 3D than 2D. This paper divided auditory perceptual information into two categories; distance and azimuth that a sound source contributes mostly, and spaciousness that scene or environment contribute mostly. According to the experiment for distance and azimuth, i.e. sound localization, we found that distance and azimuth of sound sources were magnified when heard with 3D than 2D video. This lead us to conclude 3D sound for localization should be designed to have more distance and azimuth than 2D sound. Also we found 3D sound are preferred to be played with not only 3D video clip but also 2D video clip. According to the experiment for spaciousness, we found people prefer sound with more reverberation when they watch 3D video clips than 2D video clips. This can be understood that 3D video provides more spacial information than 2D video. Those subjective experimental results can help audio engineer familiar with 2D audio to create 3D audio, and be fundamental information of future research to make 2D to 3D audio conversion system. Furthermore when designing 3D broadcasting system with limited bandwidth and with 2D TV supportive, we propose to consider transmitting stereoscopic video, audio with enhanced localization, and metadata for TV sets to generate reverberation for spaciousness.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.6
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• pp.31-43
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• 2014

Confined and mechanically ventilated broiler house has been recently come into wide use to increase productivity and control rearing conditions. However, high dust concentration inside facility can threaten respiratory welfare of farmers and broilers. In Korea, there is no regulation in terms of air quality control inside agricultural facilities and sufficient data is not available. To cope with these, periodic monitoring of inhalable and respirable dust concentration were conducted according to season, broiler's activity and specific events such as shipment work for broilers in mechanically ventilated broiler house. Chamber experiment was also designed to analyze mechanism of dust generation from ground beds according to water contents and surrounding wind environment. Results showed that significant increase of inhalable (p=0.002) and respirable (p=0.03) dust were observed when activity of broilers was high according to entrance of the workers. Even shipment work for matured broilers, high level of dust were observed; inhalable dust was exceeded the threshold limit over maximum 303 % and respirable dust was over maximum 1,550 %, implying that acute respiratory symptoms could be manifested for the workers. From the chamber experiment, critical water contents for interrupting of dust generation were measured; about 45 % for inhalable dust and about 50 % for respirable dust. These results can be a trigger for designing plan of dust control however it still needs consideration of various environmental conditions, hygiene problems, etc.

• Journal of The Korean Association For Science Education
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• v.12 no.2
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• pp.109-128
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• 1992

Elementary science textbooks are the major instructional materials which contain sceientific objectives to be acquired by students. The purpose of this study is to analyze the development system, to evaluate the inquiry activity in current elementary science testbooks, and to make suggestions for the improvement of them. The questionnaires were administered to 116 subjects that participated in development of the 5th elementary science textbooks, and 86 of the subjects responded. Based on the data gathered and analyzed in this study, the major findings are as follows. First, regarding the analysis and evaluation of elementary science textbooks. 1. The instructional objectives in elementary science textbooks are analyzed. The proportions of comprehension objectives is 38%, scientific inquiry process objectives 21%, experimental skills objectives 7%, scientific attitudes and interests objectives 4%. 2. The science concepts in elementary science textbooks of the 3rd grade required the preconcrete operational level(82%) and of the 6rd grade required the postconcrete operational level (73%) by J. Piaget 3. The inquiry activities in elementary science textbooks are emphasizing gathering and organizing results and evaluation, and hypothesizing and designing an experiment Inquiry index of the elementary science textbooks is 76. This is significantly higher than 35${\sim}$50 of America and U.K.. 4. The number of questions per class hour is mostly three, and most of them require the students to explain phenomena in nature or in experiment Second, regarding the development system of elementary science textbooks. 1. The budget for and the period of the development of elementary science textbook should be expanded. 2. For the improvement of elementary science textbooks, more abundant resources and time should be used for the basic study and the field trial of textbooks. 3. The elementary science textbook must include the affective objectives as well as the scientific knowledges and scientific inquiry skills. 4. It is not desirable to assign equal number of pages to the content of physics, chemistry, biology, and earth science. 5. Closer cooperation system is needed among the ministry of education, development research center and the field trial schools.

• Korean Journal of Construction Engineering and Management
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• v.19 no.3
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• pp.97-104
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• 2018

This paper aims to evaluate the performance of S University's Premier Global Construction Engineer Training Program. The net impact of the program is evaluated through a quasi-experiment design approach. The competency level of an individual participant is compared with that of a non-participating expert with similar professional background. The results show that the training program contributed to a significant improvement in the professional competencies of the participating students. The competency level was regressed on the subjects of curriculum. The achievements are attributable to a group of subjects focused on the skills for project development such as PPP, feasibility study, and project financing. Another group of subjects found to have significantly contributed to the improved competencies can be categorized as subjects focused on nurturing global perspectives. The paper shows it is possible to quantify the contribution of the program and the results provide a set of information that can be useful in designing and operating similar programs.