• Journal of the Ergonomics Society of Korea
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• v.23 no.4
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• pp.35-43
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• 2004

The purpose of this study is to redesign a letter sorting station and to present the optimal work-space through the ergonomic analysis of the sorting station for reducing the 'Work-Related MusculoSkeletal Disorders(WMSDs)'. We surveyed the work environment in terms of the reason causing WMSDs. According to the survey results, Deltoid on the arm, Trapezius on the shoulder and Erector Spinae on the waist are most frequent attacking parts. Accordingly, We classified sorting stations by the horizontal work-space(Level 1, Level 2, Level 3) and the vertical work space(Level 1, Level 2) based on the criteria of ergonomic optimal work-space. In addition we improved the sorting station through investigation and analysis of the work-load regard the each defined work-space. In order to analyze the effect of the horizontal and vertical work-space, subjects carried out simulated sorting tasks. Each level(Level 1, Level 2, Level3) of the horizontal work-space is significant regarding each muscles(the shoulder, arm and waist), and each level(Level 1, Level 2) of the vertical work-space is significant regarding the arm and waist, but not shoulder. Finally, we founded the difference of work-load according to the work-spaces. Then, it is necessary to improve the work-space causing the high work-load(Level 3 of the horizontal work-space). Then, this study presented the specification of a sorting station which is suitable to the korean body size, and constructed the 3D shaped model of the stations by the ergonomic analysis.

• Bulletin of the Korean Space Science Society
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• 2010.04a
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• pp.39.3-39.3
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• 2010

Solar-terrestrial links in short-time scales(daily ~monthly) are extensively explored in recent years: such as a response of low cloud amounts to the Forbush decrease, a response of Northern Atlantic oscillation index to sudden increase in electric field intensity of solar wind and so on (e.g., Svensmark et al., 2009; Boberg & Lundstedt, 2002). In this study, we perform the superposed epoch analysis to see any possible response of the sea-level pressure over Korean peninsula to the fast solar wind stream. Data sets are daily values, and zero days are determined to be days when the solar wind velocity exceeds 800km/s. Average profile of superposed sea-level pressure shows a gradual increase during the first 2 days and a decrease afterward below the normal level with a low pressure condition maintained for a few days. This result indicates that the sea-level pressure may respond to the fast solar wind stream. In other words, the average profile of sea-level pressure mimics the average velocity profiles. The correlation coefficient between two average profiles is 0.80, with 2 day lag.

• Journal of Power Electronics
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• v.14 no.5
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• pp.937-945
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• 2014

This paper presents an optimized space vector pulse-width modulation (OSVPWM) technique for a five-level cascaded H-bridge (CHB) inverter. The space vector diagram of the five-level CHB inverter is optimized by resolving it into inner and outer two-level space vector hexagons. Unlike conventional space vector topology, the proposed technique significantly reduces the involved computational time and efforts without compromising the performance of the five-level CHB inverter. A further optimized (FOSVPWM) technique is also presented in this paper, which significantly reduces the complexity and computational efforts. The developed techniques are verified through MATLAB/SIMULINK. Results are compared with sinusoidal pulse-width modulation (SPWM) to prove the validity of the proposed technique. The proposed simulation system is realized by using an XC3S400 field-programmable gate array from Xilinx, Inc. The experiment results are then presented for verification.

• Journal of Korea Game Society
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• v.17 no.5
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• pp.19-26
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• 2017

A game player experiences gameplay that game designer sets in play space according to goal of a game. Player's experiential behaviors are affected by the space structure of game level and its arrangements. Therefore, it is an important process to understand and analyze the space structure of game level at the initial stage of game designing. In this paper, we was aimed to analyze the space structure and components of FPS game level based on space theory. To attain the objective, observation was carried out on a total of 204 levels in 3 different kinds of FPS games and the difference in the distribution of spatial composition factors by the goal of a game level was identified. As a result of the analysis, experiential behaviors in the play space show a clear difference according to the goal of the game level and the space structure that derives this is different.

• Journal of the Korean Society of Earth Science Education
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• v.6 no.3
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• pp.252-260
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• 2013

The purpose of this study is find out the correlation of level of knowledge of pre-service elementary teacher with space perception ability on 'Earth and Space' of elementary science. During the second semester of 2013, for 15 weeks, the classes were conducted for 3 hours per week and we find out knowledge Understanding degree and select terms offered by 5th grade science courses 'The solar system and the stars', 'Earth and Moon', 'change of seasons' section and measured space perception ability degree of pre-service elementary school teacher with a questionnaire. We analyzed the correlation of understanding level of knowledge in the field of astronomy of pre-service elementary school teacher with space perception ability. The results of the study are presented as follows. First, pre-service elementary school teacher showed a low level of knowledge understanding as it goes the upper grades about upper concept in 'The solar system and the stars', 'Earth and Moon', 'change of seasons' section' of astronomy area of elementary science 'Earth and space sector'. The pre-service elementary school teachers needs to acquire knowledge of astronomy area in elementary school curriculum. Second, pre-service elementary school teacher showed that there are differences individually in 'finding solid body' of sub-element of space perception ability. This shows that 'finding solid body' factor is associated with space perception ability. Third, in the section of 'The earth and the Universe' for elementary education, 'Reflection' and 'Finding solid body' which are low-level components of space perception ability were verified that have a corelationship with general grades in the astronomy conception test.

• Journal of Power Electronics
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• v.12 no.2
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• pp.285-293
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• 2012

Multilevel inverters have gained attention in high-power applications due to their numerous advantages in comparison with conventional two-level inverters. In this paper a simplified Space-Vector Modulation (SVM) algorithm for a three-level Neutral-Point Clamped (NPC) inverter is implemented on a Freescale$^{(R)}$ DSP56F8037. The algorithm is based on a simplification of the space-vector diagram for a three-level inverter so that it can be used with a two-level inverter. Once the simplification has been achieved, calculation of the dwell times and the switching sequences are carried out in the same way as for the two-level SVM method. Details of the hardware design are included. Experimental results are analyzed to validate the performance of the simplified algorithm.

• Journal of the Korean Institute of Educational Facilities
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• v.2 no.2
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• pp.51-64
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• 1995

This study investigates possible of linkage between kindergarten infants and the lower level elementary school students so aims to take a triangular position which direction of architectural space plan. The results of the study are as follows: 1) The results of analysis which infants and lower level elementary school students' behavior and activity showed similar play patterns in space attitude, rule of space use, similar to satisfaction and kinds of play, the time required, groups scale and place of play. 2) Architectures of kindergarten and lower level elementary school can classify style of selfhelp-singleness, establishment as an annex-singleness, establishment as an annex-attachment and divides space of education, management, service and analogized kinds of necessary space. 3) Infants of four, five years old and six, seven years old(first, second elementary school students) are similar to physical, intellectual, emotional development and have special characters of successions so kindergarten and lower level elementary school buildings must be necessary for organic linkage and intergration.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2005.11a
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• pp.269-272
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• 2005

The purpose of this study is to analyze the relation between the dwelling location and the satisfaction level, and suggest a proposal to increase the quality of the livability space. A first of this study began from public surveys conducted to gather the information of satisfaction level from 4 multi-family housing sites in Gwang-ju. The plan was to the characteristics of the LS(livability space). The poll and the observation investigation was run concurrently. The cross analysis and the frequency analysis were used to analyze the data from the questionnaires. The validity of fixed quantitative index was got through the correlation analysis between the result of former analysis and index of livability space. The result said that the dwelling location have relations with the satisfaction level. In the conclusion, this will be a suggestion of the methods to enhance equal-quality of the livability space.

• Journal of the Korean housing association
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• v.8 no.3
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• pp.197-207
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• 1997

This study is about the improvement of housing environment through the research and analysis on how district-level roads are used and what the residents want about housing environment. The results are as follows: 1. As a result of the research on space usage, we could get the conclusion that street furniture occupies much space in the district-level roads, and the main causes of the space usage problems are from cars. 2. Because much space is used for parking, the district-level roads supposed to be the place for the pleasant and safe housing is changing into the main cause of the housing problems. Therefore we should find how to prevent the housing environment from being deteriorated through pridicting the traffic generation of future residential area. 3. Most residents park their cars near their houses in the district-level roads. In order to solve this problem, we have to secure the parking space and guarantee the safe traffic by designing the road space efficiently in spite of the inconvenience.

• Journal of the Korean housing association
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• v.20 no.6
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• pp.119-126
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• 2009

This study focused on the analysis of residential satisfaction and environment awareness depending on the environment-friendly level on the outdoor space of the housing complexes. The purpose of this study is to present basic materials of the environment-friendly outdoor space planning of housing complexes. The major findings of the study are as follows. First, the results of the comparative analysis of the satisfaction of the outdoor space of apartment complexes show that the complexes with the most application of environment-friendly elements had higher residential satisfaction. But there was no meaningful statistical difference between the complexes with the higher level of application of the environment-friendly elements and the complexes with medium level of application. Secondly, according to a comparative analysis, the overall residential satisfaction of the apartment complexes was the same as the residential satisfaction of the outdoor space. Thirdly, the results of the correlative analysis of residential satisfaction and environmental awareness showed that the satisfaction of the apartment complexes decreases as the awareness of the environment-friendly apartment complex increases. The results of this study can be used as basic materials for environment-friendly outdoor space planning of apartment complexes.