• Journal of the Korean Institute of Gas
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• v.25 no.4
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• pp.27-35
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• 2021

Recently, as a solution to the sharp drop in "power reserve ratio", it is being converted to a microgrid that enables bi-directional transmission and distribution. A microgrid is composed of a small-scale distributed power supply and a load. As a representative technology of distributed power generation, there is a Micro Combined Heat and Power system applied to homes and buildings. In this study, a safety standard was developed by dividing the power generation system, cooling system, lubrication system, and exhaust system to derive safety standards for a small gas engine power generation system with a gas consumption less than 232.6kW (200,000 kcal/h). In the case of the power generation system, a filter was installed and the system was stopped by detecting gas leakage and abnormalities in engine speed or output and the cooling system is stipulated to stop the system in case of insufficient cooling water or overheating. The lubrication system monitors the pressure and temperature of the lubricating oil and stops the system when an abnormality occurs, and the exhaust gas emission concentration regulation value was specified in accordance with domestic and foreign standards. Through the results of this study, it is judged that the safety of the gas engine power generation system can be improved and it can contribute to the commercialization of products.

• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.475-483
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• 2019

Special chemical warfare agents are lethal gases that attack the human respiratory system. One of such gases are blood agents that react with the irons present in the electron transfer system of the human body. This reaction stops internal respiration and eventually causes death. The molecular sizes of these agents are smaller than the pores of an activated carbon, making chemical adsorption the only alternative method for removing them. In this study, we carried out a Computational Fluid Dynamics simulation by passing a blood agent: cyanogen chloride gas through an SG-1 gas mask canister developed by SG Safety Corporation. The adsorption bed consisted of a Silver-Zinc-Molybdenum-Triethylenediamine activated carbon impregnated with copper, silver, zinc and molybdenum ions. The kinetic analysis of the chemical adsorption was performed in accordance with the test procedure for the gas mask canister and was validated by the kinetic data obtained from experimental results. We predicted the dynamic behaviors of the main variables such as the pressure drop inside the canister and the amount of gas adsorbed by chemisorption. By using a granular packed bed instead of the Ergun equation that is used to model porous materials in Computational Fluid Dynamics, applicable results of the activated carbon were obtained. Dynamic simulations and flow analyses of the chemical adsorption with varying gas flow rates were also executed.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.2
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• pp.119-133
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• 2022

Due to the improvement of surveying, mapping and communication techniques, various apps for road direction guides and vehicle navigations have been developed. Although such a development has impacted on walking and driving, there is a limit to improving the daily convenience of the socially impaired people. This is mainly due to the fact that the software have been developed for normal pedestrians and drivers. Therefore, visually impaired people still have problems with the confusion of direction and/or non-provision of risk factors in walking. This study aimed to propose a scheme which constructs data for mobility-impaired or traffic-impaired people based on various geospatial information. The factors and components related to walking for the visually impaired are selected by geospatial data and a walking route guidance network that can be applied to a commercial software. As a result, it was confirmed that road direction guidance would be possible if additional contents, such as braille blocks (dotted/linear), sound signals, bus stops, and bollards are secured. In addition, an initial version of the application software was implemented based on the suggested data model and its usefulness was evaluated to a visually impaired person. To advance the stability of the service in walking for the visually impaired people, various geospatial data obtained by multiple institutes are necessary to be combined, and various sensors and voice technologies are required to be connected and utilized through ICT (Information and Communications Technologies) technology in near future.

• Journal of the Korean Regional Science Association
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• v.38 no.4
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• pp.3-17
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• 2022

This study aims to empirically analyze the impacts of the topographic characteristics of residential areas and the characteristics of land use and transportation on average trip distance of the senior citizens in Busan Metropolitan city. Multiple regression is conducted to accomplish the purpose of this study, and the conclusions and policy implications of the analysis are as follows. First, the average and standard deviation of the residential areas are significantly related to average trip distance of the senior citizens. Thus, urban transportation policies need to take account of the topographic characteristics of the residential areas. Second, average distance from the nearest subway station and density of bus stops have positive and negative association respectively. Mobility improvement polices for senior citizens should consider urban spatial structure and different approach processes to transportation facilities by modes. Third, mobility and residential environment improvement policies for senior citizens should take into account different sociodemographic characteristics by locations. This shows that the mobility convenience policy for senior citizens is more necessary than any other policy for administrative dong, where traffic access is relatively low and the single senior citizen population is concentrated.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.109-115
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• 2022

Vitellogenesis is the process by which yolk accumulates in developing oocytes. The initiation of vitellogenesis represents an important control point in oogenesis. When females of the model insect Drosophila melanogaster molt to become adults, their ovaries lack mature vitellogenic oocytes, only producing them after reproductive maturation. After maturation, vitellogenesis stops until a mating signal re-activates it. Juvenile hormone (JH) from the endocrine organ known as the corpora allata (CA) is the major insect gonadotropin that stimulates vitellogenesis, and the seminal protein sex peptide (SP) has long been implicated as a mating signal that stimulates JH biosynthesis. In this review, we discuss our new findings that explain how the nervous system gates JH biosynthesis and vitellogenesis associated with reproductive maturation and the SP-induced post-mating response. Mated females exhibit diurnal rhythmicity in oogenesis. A subset of brain circadian pacemaker neurons produce Allatostatin C (AstC) to generate a circadian oogenesis rhythm by indirectly regulating JH and vitellogenesis through the brain insulin-producing cells. We also discuss genetic evidence that supports this model and future research directions.

• Korean Journal of Social Welfare Studies
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• v.40 no.1
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• pp.235-260
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• 2009

This study aims to analyze consumption inequality of Korean elderly households. The justification for analyzing consumption inequality during old age could be summarized as follows. First, due to the rapid growth of elderly population, the intra generational inequality of older people will bring greater consequences to the society in the coming years. Second, inequality is more actualized during old age when income stops playing a major role and the everyday lives are based mostly on consumption activities. For analysis, this study used the 2nd, 5th, 7th and 9th wave of 『Korea Labor and Income Panel Study』. The findings are as follows. First, total consumption inequality of elderly households is gradually decreasing after the economic crisis. Also, the gini coefficient of consumption items representing modern consumption culture, such as expenditures on eating out and car maintenance is decreasing. However, the inequality contribution rate of such items is continually rising, indicating that whereas the elderly households in general are being assimilated to the mainstream consumption culture, the disparity between classes is continually expanding. Second, gini coefficient and inequality contribution rate of the essentials such as food and housing has decreased indicating that basic livelihoods in general has risen. Third, the inequality of education expenditure is increasing after the year 2000 which implies that the problem of education inequality in general might have an effect on elderly households.

• Journal of Soil and Groundwater Environment
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• v.13 no.1
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• pp.43-51
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• 2008

Periodic fluctuation of water levels were analyzed for their causes and effects on groundwater movement. Groundwater levels were monitored from two shallow monitoring wells, G1 and G4, located at a headwater catchment in the Gwangneung Ecohydrological Research Site using pressure transducers with automatic data-loggers by five-minute interval from February to October, 2006. The water table fluctuates on a daily basis with a clear diurnal variation, and the fluctuation amplitude increases with time from the winter to the summer. Results from spectral analysis of water-level data show periodic variations in 24.38 hour and in 12.19 hour, indicating $P_1$ diurnal and $L_2$ semidiurnal tidal components, respectively. The diurnal component of the water level in summer has greater power than that in winter, implying that the water table is affected not only by earth tides, but also by evapotranspiration. Right after rain stops, the power of diurnal component of the water level decreases, indicating that evapotranspiration influences significantly diurnal periodicity. The effects of diurnal and semidiurnal components of the water level range from 0.4 to 4.2 cm and from 0.2 to 0.7 cm, respectively.

• Journal of the Economic Geographical Society of Korea
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• v.9 no.2
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• pp.149-166
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• 2006

The purpose of this study is to produce time-distance cartograms based on the various Korean transportation networks, and to analyze the spatial structure of time-distance accessibilities. For the purpose this study attempts to develop continuous area cartogram by utilizing Wolf's algorithm for creating contiguous cartogram in ArcGIS 9. The absolute physical space was transformed to the functional space indexed by time-distances along various transportation networks in Korea. We examined the differences in the time-distance accessibilities among transportation networks. This study makes a comparison between the spatial structure of time-distance accessibility of KTX network with them of existing railroad network, as well as with them of road network. In order to clarify the spatial structures of time-distance accessibilities, we restructured them on the time-distance circular diagrams and performing Multi-Dimensional Scaling analysis. Overall structure of time-distance accessibilities shows similar patterns: The time distances are shrinked a lot along the Seoul-Busan axis, while coastal parts, in particular the eastern part of the county, are shrinked relatively little via all transportation networks. The Road network affects significantly on the accessibilities of cities in Gangwon-do and Gyeonggi-do, while railway network affects on the accessibilities of cities in Jeolla-do and Gyeongsang-do in general. When we compared the time-distance accessibilities based on the 5 largest cities, Seoul appears as the most accessible city from/to all other cities in Korea. We can also find significant changes in the time-distance accessibility between KTX network and existing railroad network. Cities along the KTX network, in particular cities which has KTX stops, improved significantly in time-distance accessibilities.

• Journal of KIISE:Databases
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• v.33 no.7
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• pp.655-667
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• 2006

Due to the rapid development in mobile communication technologies, the usage of mobile devices such as cellular phones and PDAs becomes increasingly popular. One of the best ways to maximize the usability of mobile devices is to make them aware of their current locations and the locations of other fixed and mobile objects. In this paper, we propose a cost-effective Bus Information System, ACE-BIS, which utilizes a mobile device to retrieve the bus routes to reach a destination from the current location. To accomplish this task, ACE-BIS maintains a small amount of information on bus stops and bus routes in a mobile device and runs a heuristic routing algorithm based on such information. When a user asks more accurate route information or calls for a 'leave later query', ACE-BIS entrusts the task to a server into which real-time traffic and bus location information is being collected. By separating the roles into a mobile device and a server, ACE-BIS is able to provide bus routes at the lowest cost for wireless communications, without imposing much burden to a server. The results of extensive experiments revealed that ACE-BIS is effective and scalable in most experimental settings.

• Cartoon and Animation Studies
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• s.6
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• pp.7-22
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• 2002

Animation constitutes the core of the media industry, which in turn lies at the center of the cultural industry. It is considered one of the industries where South Korea has the competitive edge over other countries. With the pool of customers getting wider, the genre of animation has become more and more diverse, forming a great market for it. Aware of this trend, this study focused on animation as a part of the pop culture, and on providing corresponding various viewpoints for future cultural studies. This researcher measured the practicality and persuasiveness of this study through Shreck, a three-dimensional C.G. animation which is acclaimed for its success in dismantling the old grammar of animation movies that represent the anti-Disney ideas. This researcher felt it imperative to heed the unique language of Shreck, which contains discourses on various cultural ideologies such as paradoxical structure that pits entertainment that is shown through dismantling of the canon, feminism and antifeminism against each other. This study analyzed the entertaining element of the animation genre by means of the Semiotics of Keith Moxey, thereby attempting to establish a legitimate social status of the genre, whose artfulness has been depreciated in the art society. In chapter II, this researcher examines the chronological development of three-dimensional C.G. animation that has shown a rapid advancement. Chapter III defines the cultural ideology of Shreck by exploring basic theories and texts employed in analysis of art works. This study started with the assumption that defines, from the viewpoint of symbology, the animation text as an aggregate of discourses on entertainment, and competitive and paradoxical ideologies. Then, this researcher analyzed the text and the generation process of meanings in Shreck. Consequently, this study has come to the following conclusions: First, Shreck induces changes of concepts about the canon by means of distorting and reversing the existing animation movies, which seems to reflect in the contemporary tendency of seeking new interpretations of entertainment. Second, Shreck shows up the cognitive changes of our age as to feminism by competing feminism against antifeminism. Although Shreck serves as a venue of competition between the two opposing ideas, it stops short of brushing off women as outsiders in society. Rather, it represents the resistance to the male chauvinism existing in the structures of animation and culture. As shown in the text analysis, Shreck presents an advent of a new ideology critical of the previous animation films. In addition, it reflects in the struggle between the pro-feminism on the part of the viewers and the anti-feminism that lies in the social and culture structure. This study, however, is limited in its scope and selection of subject. First, although this researcher has stressed the importance of understanding the animation as part of the pop culture and conducting researches within the historic paradigm, this study fails to provide an in-depth insight in the impacts that the changes in the C.G. industry and the systematic conditions may have on the three-dimensional C.G. animation genre. Furthermore, this study runs the risk of being understood as pro-American due to its selection of Shreck as its research subject.