• Korean Journal of Ecology and Environment
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• v.36 no.1 s.102
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• pp.74-82
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• 2003

This study was carried out to understand how the bird community would change in a stream ecosystem after implementation of close-to-nature river improvement techniques conducted on the Gwacheon, Seocho and Hakyeul reaches in the Yangiae Stream, 'Seoul. At the Gwacheon reach, the number of species and individuals tended to decline. However, at the Seocho reach, the number of species was increased while the number of individuals appeared to be not changed greatly. Especially, density of Dabbling Ducks were rapidly increased. At the Hakyeul reach was both the number of species and the number of individuals were increased. Density of Herons and Dabbling Ducks rose, while density of Wagtails was decreased suddenly. Except the Gwacheon reach, the survey areas were gradually improved in species richness and density after the construction of river improvement. We suggested that the naturally-formed meandering (channel) bar, restoration of riparian vegetation and artificial ponds were helpful for birds habitation, however bicycle path constructed in flood plain was negative.

• Korean Journal of Environment and Ecology
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• v.26 no.6
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• pp.884-891
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• 2012

The characteristic of fish fauna and distribution by habitat type in the Yanghwa stream were investigated from August, 2008 to June, 2009. During the surveyed period, 30 species belonging 8 families were collected. And there were 10 Korea endemic species(33.3%), including Rhodeus uyekii et and so on. Dominant species was Rhodeus notatus, and subdominant species was Pseudorasbora parva. Dominant species according to habitat type was Pseudorasbora parva in Dam type pool and Channel conected pool, Pseudogobio esocinus(Run), Zacco platypus(Riffle), Rhodeus notatus(Side channel and Substrate type pool), Squalidus gracilis majimae(Meander type pool), and Carassius auratus(Channel unconnected pool), respectively. As a results of community analysis in the Yanghwa Stream, diversity, richness, and abundance indices showed relatively high values, indicating that studied stream have relatively stable community structure. Moreover, cluster and principal component analysis were divided by two groups(lotic and lentic habitats), suggest that species and individuals were different among habitat types.

• 한국해양학회지
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• v.30 no.3
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• pp.170-183
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• 1995

Eddies and surface current field in the southwestern part of the East Sea were investigated using satellite-tracked drifters, CTD, and ADCP from November 1992 to September 1993. Trajectories of surface drifters provided information for the first time on the meandering motion of the East Korean Warm Current in the Ullung Basin (referred as UB) and clearly indicated the existence of cyclonic and anticyclonic eddies of various scales. Anticyclonic eddies persisting for a relatively long period were observed in UB and the southwestern corner of the Northern (Japan) Basin (SNB), while a cyclonic eddy was found in the coastal area between Sokcho and Donghae during the summer. Analysis shows that the eddy in UB behaved as a stationary eddy at least during the observation period and the cyclonic eddy was closely related to the existence of a cold water mass. The anticyclonic eddy in SNB was larger than that in UB, but much elongated in shape. The eddy in UB is characteristic of major and minor axes of about 120 and 70 km, revolution period of 13.6 days, mean swirl velocity of about 24 cm/s, and mean eddy kinetic energy of 392 cm$\^$2//s$\^$2/. The eddy in SNB is described as follows; major and minor axes of 168 and 86 km, period of 14.9 days, mean swirl velocity of 29 cm/s and mean eddy kinetic energy of 629 cm$\^$2//s$\^$2/. The mean translational speed is about 3 cm/s for both eddies. The agreement of the surface current pattern in UB observed by ADCP with the geostrophic flow pattern may suggest that the eddy in UB was nearly in geostrophic balance. The eddy was found to be strongly bottom-controlled.

• The Journal of the Korea Contents Association
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• v.16 no.3
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• pp.415-425
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• 2016

Game industry is certain to change rapidly as its attribute. Therefore, It's not easy that the law response to reflect the technological change of game industry properly, and a new legal issue that is difficult to cover with the existing law. Recently, Court battle or cases about games are socially receiving attention. Nevertheless, Research accumulation about the legal action to response this is rare situation. The legal system that is related games mostly approach in the regulation and punishment of one-sided administration so far. Relatively, Approach from the game industry development and promotion act standpoint is low. Shrinking rapidly the current game industry is not an irrelevance to this. So It is necessary to reconstruct rationally in side that embrace with variety of views of members of the society and interests about current game-related laws, systems and regulation instruments. Access to how will develop competitiveness of the game industry in legal aspects and how will promote the balanced development between game industries are needed. The problems that needs to handle in legal aspect such as game development, game distribution, and game usage which in the part of the game industry are getting more and more in the future. Therefore, there is a need to review consistently in the legal aspect for the game industry promotion.

• Korean Journal of Environmental Biology
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• v.36 no.2
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• pp.156-164
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• 2018

In order to investigate the upwelling and island effects following the wind storm events in the East Sea (i.e., Uljin-Ulleungdo-Dokdo line) during spring, we assessed the vertical and horizontal profiles of abiotic and biotic factors, including phytoplankton communities. The assessment was based on the Geostationary Ocean Color Imager (GOCI) and field survey data. A strong south wind occurred on May 3, when the lowest sea level pressure (987.3 hPa) in 2016 was observed. Interestingly, after this event, huge blooms of phytoplankton were observed on May 12 along the East Korean Warm Current (EKWC), including the in the offshore waters of Ulleungdo and Dokdo. Although the diatoms dominated the EKWC area between the Uljin coastal waters and Ulleungdo, the population density of raphidophytes Heterosigma akashiwo was high in the offshore waters of Ulleungdo-Dokdo. Based on the vertical profiles of Chlorophyll-a (Chl. a), the sub-surface Chl. a maximum appeared at 20 m depths between Uljin and Ulluengdo, whereas relatively high Chl. a was distributed equally across the entire water column around the waters of Ulleungdo and Dokdo islands. This implies that the water mixing (i.e., upwelling) at the two islands, that occurred after the strong wind event, may have brought the rapid proliferation of autotrophic algae, with nutrient input, to the euphotic layer. Therefore, we have demonstrated that a strong south wind caused the upwelling event around the south-eastern Korean peninsula, which is one of the most important role in occurring the spring phytoplankton blooms along the EKWC. In addition, the phytoplankton blooms may have potentially influenced the oligotrophic waters with discrete time lags in the vicinity of Ulleungdo and Dokdo. This indicates that the phytoplankton community structure in the offshore waters of Ulleungdo-Dokdo is dependent upon the complicated water masses moving related to meandering of the EKWC.

• The Journal of the Korea Contents Association
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• v.17 no.1
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• pp.426-435
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• 2017

Since online betting occurs on online where anybody can access through internet, thus, the online gambling market has been expanding. Domestic illegal gambling market size is 4 times bigger than that of legal gambling market, and illegal online betting market is rapidly growing as well. Currently online gambling does exist domestically in form of Sports promotion voting rights, also known as, Toto and Proto and internet lottery. However, the need for other types of online gambling to be permitted, expanded and managed has been suggested. This research has analyzed online gambling users, online gambling addicts and general population's awareness on expansion and operation of online gambling, contraction measures of illegal online gambling and operation measures in case of permitted expansion of online gambling. The result of this research's analysis showed that each group has significantly different awareness level on positive and negative effects of permitting online gambling's expansion. Also, it showed that each group has significantly different awareness on permitting expansion of racing betting as a legal gambling item. Since it is the proven fact that illegal online gambling users could turn into legal users and that users could use the service more positively if online gambling is legalized through allowance and expansion process; one could expect the positive effects from permitting expansion of online gambling.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.553-555
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• 2013

Game Rating Board(GRB) of Korea set up in 29 October, 2006 has been 7th years and it will disappear in 23 November, 2013. For the first time the 'GRB' of Korea has the goal which held the nonofficial transfer of rating classification for game. But it had the justification which become more distant from the nonofficial transfer due to the affairs of 'See Story' in August, 2006. As a result, because of rapid normalization of game rating rather than the systematic transfer from 'Video Rating Board' of Korea cause no preparation of scientific professional rating review. It showed the entry-level appearance though stressing profession from the beginning of setup. Specially more transaction expense were increased because of no consistency and predictability for game review. However, it could be overcome by preparation for definite global standard and scientific rating system. Consequently technological possibility of BMM Korea based on 'Gaming Laboratory Institute(GLI)' standard expected to be alternative in the technical review of the adult arcade game.

• Journal of Korea Water Resources Association
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• v.48 no.4
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• pp.291-298
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• 2015

The aim of this study is that a theoretical formula for estimating the one-dimensional longitudinal dispersion coefficient is derived based on a transverse distribution equation for the depth averaged stream-wise velocity in open channel. In "Part I. Theoretical equation for stream-wise velocity" which is the former volume of this article, the velocity distribution equation is derived analytically based on the Shiono-Knight Model (SKM). And then incorporating the velocity distribution equation into a triple integral formula which was proposed by Fischer (1968), the one-dimensional longitudinal dispersion coefficient can be derived theoretically in "Part II. Longitudinal dispersion coefficient" which is the latter volume of this article. SKM has presented an analytical solution to the Navier-Stokes equation to describe the transverse variations, and originally been applied to straight and nearly straight compound channel. In order to use SKM in modeling non-prismatic and meandering channels, the shape of cross-section is regarded as a triangle in this study. The analytical solution for the velocity distribution is verified using Manning's equation and applied to velocity data measured at natural streams. Although the velocity equation developed in this study do not agree well with measured data case by case, the equation has a merit that the velocity distribution can be calculated only using geometric data including Manning's roughness coefficient without any measured velocity data.

• Journal of the Korea Convergence Society
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• v.9 no.2
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• pp.137-143
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• 2018

This study is an interaction design study which can improve the usability of random item boxes that are used as in - game contents in Korean mobile games. Currently, Korean mobile game sales continue to rise. Sales of random item boxes are the main reason for the increase in sales. Problems with the use of random item boxes have been continuously raised, and legal regulations are currently in place. When using random item boxes, the user can not know the exact percentage information. There is a concern that this expresses gambling. In this context, we have studied interaction design to improve the usability of random item boxes, and conducted user online surveys and in - depth interviews to provide users with a better game experience. As a result, it is shown that providing percentage information intuitively when using random item boxes can enhance user experience. Through this study, it is expected that interaction design research will be actively conducted to provide a better user experience when using random item boxes.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.2
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• pp.121-128
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• 2020

The purpose of this study is to investigate the distribution patterns of displacement and acceleration fields in a nonlinear soil ground based on the interaction of high-speed train, wheel, rail, and ground. For this purpose, a high-speed train in motion was modeled as the actual wheel, and the vertical contact of wheel and rail and the lateral contact, caused by meandering motion, were simulated; this simulation was based on the moving mass analysis. The soil ground part was given the nonlinear behavior of the upper ground part by using the modified the Drucker-Prager model, and the changes in displacement and acceleration were compared with the behavior of the elastic and inelastic grounds. Using this analysis, the displacement and acceleration ranges close to the actual ground behavior were addressed. Additionally, the von-Mises stress and equivalent plastic strain at the ground were examined. Further, the equivalent plastic and total volumetric strains at each failure surface were examined. The variation in stresses, such as vertical stress, transverse pressure, and longitudinal restraint pressure of wheel-rail contact, with the time history was investigated using moving mass. In the case of nonlinear ground model, the displacement difference obtained based on the train travel is not large when compared to that of the elastic ground model, while the acceleration is caused to generate a large decrease.