• Journal of the Korean Society of Industry Convergence
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• v.14 no.4
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• pp.135-142
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• 2011

Convergence between telecom and broadcasting is today a worldwide phenomenon. Diverse services like VoD, mobile broadcasting, IPTV and interactive services have already made their market debut or are currently being commercialized. Regulatory systems are also being revised to appropriately regulate this new breed of services. We propose the new model of educational broadcasting system using the internet network, it is not different conventional coaxial cable methods. Especially, we design the multicast method of the network using the limited channel and resource, propose the method of intercommunication in the school between the broadcasting system and database system.

• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.2
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• pp.201-211
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• 2015

Acoustic propagation in shallow water with changing environments is a major concern of navy. Temporal and spatial variability of acoustic propagation in the northern East China Sea (ECS) is studied, using the 11 years hydrographic data and the Bellhop acoustic model. Acoustic propagation in the northern ECS is highly variable due to extensive interaction of various ocean currents and boundaries. Seasonal variations of transmission loss (TL) with various source depths are highly affected by sharp gradient of sound speed and bottoms interaction. Especially, various bottom sediment types lead to severely degrading a waterborne propagation with bottom loss. In particular, the highly increased TL near the ocean front depends on the source position, and the direction of sound propagation.

• 한국해양학회지
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• v.20 no.1
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• pp.1-11
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• 1985

Two Typhoon surges generated during the period of July-August 1978 are investigated dynamically using a vertically-integrated finite-difference model of the Yellow Sea and the East China Sea, Computed residuals are compared oeth hourly records from selected tide gauges (Inchon, Kunsan, Mokpo, Jeju, Yeosu) slong the coast of Korea. Some of the preliminary results are presented and discussed. This initial hindcast study has been undertaken in association with SEASAT-A altimeter data correction work in the East China Sea.

• Ocean and Polar Research
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• v.23 no.2
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• pp.133-139
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• 2001

Ocean currents estimated from sea height anomalies derived from inter-calibrated TP/ERS are compared with daily mean currents measured with satellite-tracked drifters. The correlation coefficient between the geostrophic current from TP/ERS and surface current at 15 m depth from drifter tracks was found to be about 0.5. Due to the limitation of satellite ground tracks, small scale eddies less than 80 km are poorly resolved from TP/ERS. One of the interesting results of this study is that coastal currents along the eastern coast of Korea were well reproduced from sea height anomalies when the coastal currents were developed in association with eddies near the South Korean coast. The eddy kinetic energy (EKE) estimated from drifters, TP/ERS, and a numerical model are also compared. The EKE estimated from drifters was about 22 % higher than EKE calculated from TP/ERS. The pattern of low EKE level in the northern basin and high EKE level in the southern East Sea is shown in the EKE estimates derived from both the drifters and TP/ERS.

• 한국해양학회지
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• v.21 no.4
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• pp.229-235
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• 1986

The response of coastal water to the summertime intensification of the East Korea Warm Current is considered theoretically. A simply analytic model explains well the development of southward coastal current in the north (37-38$^{\circ}$N) and the uprising of lower cold water in the south (35-36$^{\circ}$N). The mechanism involved is the Rossby adjustment to a sudden increase of current.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.2 no.4
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• pp.231-244
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• 1990

The objectives of this multiyear research are directed toward the investigation of mesoscale circulation dynamics in the Yellow Sea and the East China Sea. With the advent of Supercomputers and increasing necessity of resolving the flow with enough details, a hydrodynamic numerical model of the East China Sea has been developed with resolution of 1/15$^{\circ}$latitude by 1/12$^{\circ}$longitude covering the entire continental shelf. As a first step M$_2$tidal regime representing the domanant tidal conditions of the shelf was computed. Preliminary results are presented and discussions for further developments are presented.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.5 no.2
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• pp.121-132
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• 1993

A three-dimensional barotropic model is used to compute meteorologically-induced circulations in the East Sea for monthly, seasonal and annual basis. The computed barotropic responses have shown that in the upper part of the 40$^{\circ}$ North latitude. counterclockwise meso-scale eddies have been formed off Dong Han Man, middle part of the East Sea and sea area between the Siberian coast and Hokkaido throughout the year except summer season. These results are in good agreements with some of earlier schematic circulation diagram.

• Asian review of World Histories
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• v.1 no.1
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• pp.117-149
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• 2013

The purpose of this essay is threefold. First, to highlight research of Seonmin KIM, whose 2006 Ph.D. dissertation elucidates complex relationships among Ming China, Choson Korea, Tokugawa Japan, and mountainous ginseng-producing "borderlands" between Korea and China; her story concludes with the remarkable rise of a borderlands power that overthrew Ming China, there-by establishing dominance that lasted into the $20^{th}$ century - the Qing Dynasty. A second purpose is to showcase application of a non-standard-model - the Hydraulic Metaphor - that elucidates economic components of Professor KIM's history via visual and intuitive mechanisms designed to be understandable for non-specialists. Last, an outline of East Asian history is placed within context of centuries of monetary evolution that eventually yielded the late-$16^{th}$-century birth of globalization.

• Ocean and Polar Research
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• v.21 no.2
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• pp.87-97
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• 1999

To estimate absolute transports by advection in the southwestern East Sea (Japan Sea), an inverse method was applied to CTD data obtained in July 1993. The relative velocities are calculated using the thermal wind equation. The inverse model was formulated to obtain a reference velocity based on the mass conservation in each of four vertical layers within a region enclosed by hydrographic sections and the coastal boundary. The flow patterns in the surface layer are clockwise and anti-clockwise in the regions south and northwest of Ulleung Island, respectively, and a strong northward flow appears in between them. In the second layer, the flow fields are generally weak. The inverse calculation yields the southward flow along the coast, and this suggests that the subsurface low salinity water in the Ulleung Basin is supplied by the southward transport along the east coast of Korea.

• International Journal of Computer Science & Network Security
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• v.21 no.2
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• pp.181-187
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• 2021

The purpose of this study is to examine empirically the short- and long-run determinants of entrepreneurial activity in a sample of 15 the Middle East and North African economies between 2006 and 2018. More specifically, four groups of determinants are considered in the analysis, namely economic, demographic, business environment, and institutional. Given the autoregressive feature of the entrepreneurial activity process, a dynamic panel data model is estimated using the system GMM estimator. Findings reveal that unemployment, trade openness, population density, and economic freedom are the main drivers of new business creation in the short-run, while the cost and number of procedures to start a new business negatively affect entrepreneurship. In the long-run, the same findings hold true. Moreover, education and political stability and the absence of violence/terrorism positively affect entrepreneurial activity. Policy recommendations are accordingly designed.