• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.90-104
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• 2001

This study is aimed to analyze and to evaluate the revegetation and soil conservation technology in desertification-affected sandy land, resulting from the project of "Studies on the desertification combating and sand industry development". Main native plants for combating desertification : The general characteristics of vegetation distribution in desertified regions are partially concentrated vegetation distribution types including the a) desert plants in low zone of desert or sanddune of depressed basin, b) salt-resistant plants around saline lakes, c) grouped vegetation with Poplar and Chinese Tamarix of freshwater-lakes, saline-lakes and river-banks, d) gobi vegetation of gravel desert and e) grassland and oasis-woods around the alluvial fan of rivers, etc. Generally, Tamarix ehinensis Lour., Haloxylon ammodendron Bunge., Calligonum spp., Populus euphratica Oliver., Elaeagnus angustifolia L., Ulmus pumila L., Salix spp., Hedysarum spp., Caragana spp., Xanthoceras sorbifolia Bunge., Nitraria tangutorum Bobr., Lespedeza bicolor, Alhagi sparsifolia Shap., Capparis spinosa L., Artemisia arenaria DC., etc. are widely distributed in desertified regions. It is necessary for conducting research in the native plants in desertified regions. Analysis of intensive revegetation technology system for combating desertification : In the wind erosion region, the experimental research projects of rational farming systems (regional planning, shelterbelts system, protection system of oasis, establishment of irrigation-channel networks and management technology of enormous farmlands, etc.), rational utilization technology of plant resources (fuelwood, medicinal plants, grazing and grassland management, etc.), utilization technology of water resources (management and planning of watershed, construction of channel and technology of water saving and irrigation, etc.), establishment of sheltetbelts, control of population increase and increased production technology of agricultural forest, fuelwood and feed, etc. are preponderantly being promoted. And in water erosion region, the experimental research projects of development of rational utilization technology of land and vegetation, engineering technology and protection technology of crops, etc. are being promoted in priority. And also, the experimental researches on the methods of utilization of water (irrigation, drainage, washing and rice cultivation, etc.), agricultural methods (reclamation of land, agronomy, fertilization, seeding, crop rotation, mixed-cultivation and soil dressing works, etc.) and biological methods (cultivation of salt-resistant crops and green manure and tree plantation, etc.) for improvement of saline soil and alkaline soil in desertified-lands are actively being promoted. And the international cooperations on the revegetation technology development projects of desertified-lands are sincerely being required.

• Geophysics and Geophysical Exploration
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• v.14 no.3
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• pp.227-233
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• 2011

Attention has been focused on geothermal energy as an alternative energy because it is continuously operable without external supply. Most of geothermal anomalies in Korea are related to deep circulation of groundwater through a fracture system in granite area. Therefore it is very important to understand the distribution of the fracture system which is the main channel of ground water. In this research, we constructed the velocity models with a fracture system and the layered sediments, respectively, and generated synthetic data sets with them to verify the presented vertical seismic profiling (VSP) preprocessing scheme. We compared the results from conventional VSP preprocessing flow to those from VSP preprocessing flow considering fracture system. We noticed that the preprocessing flow considering fracture system retains more sufficient signal including down-going wave than conventional preprocessing. In addition, we applied 3D VSP prestack phase screen migration to the preprocessed reversed VSP (RVSP) data from Seokmo Island so that we were able to image fracture structure of the geothermal site in Seokmo Island.

• The Journal of the Korea Contents Association
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• v.21 no.12
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• pp.66-75
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• 2021

The research is centered towards analyzing the usage status of YouTube platform and the nature of content supplied to YouTube by selecting Korean two Traffic Broadcastings Based on TBS(Traffic Broadcasting System) and TBN(Traffic Broadcasting Network). TBS operates 'Citizen's Broadcasting', which has 1.1 million subscribers among 13 YouTube channels, as its main channel. TBN has only 15,000 subscribers to its main 'TBN Tong', and YouTube channels in 12 local networks. TBS which has a dedicated YouTube manpower, is far ahead of TBN in terms of YouTube channel management and content composition. Both broadcasters are passive about creating new media content due to job stability. For the development of the YouTube platform for these two broadcasters, organizational changes within traffic broadcasting and changes in the perception of members are required, and live broadcasting and discovery of star creators are required. In the changing media environment two traffic broadcastings need a program distribution strategy that can be included in various media platforms.

• Journal of Soil and Groundwater Environment
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• v.17 no.6
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• pp.119-128
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• 2012

The applicability and accuracy of Revised Universal Soil Loss Equation (RUSLE) model on the estimation of soil loss at impacted area of shooting range was tested to further the understanding of soil erosion at shooting ranges by using RUSLE. At a shooting range located in northern Kyunggi, the amount of soil loss was estimated by RUSLE model and compared with that estimated by Global Positioning System-Total Station survey. As results, the annual soil loss at a study site (202 m long by 79 m wide) was estimated to be 2,915 ton/ha/year by RUSLE and 3,058 ton/ha/year by GPS-TS survey, respectively. The error between two different estimations was less than 5%, however, information on site conditions should be collected more to adjust model coefficients accurately. At the study shooting range, sediments generated by rainfall was transported from the top to near the bottom of the sloping face through sheet erosion as well as rill erosion, forming a gully along the direction of the storm water flow. Coarser fractions of the sediments were redeposited in the limited area along the channel. Distribution characteristics of explosive compounds in soil before and after summer monsoon rainfall in the study area were compared with the erosion patterns. Soil sampling and analyses results showed that the dispersion of explosive compounds in surface soil was consistent with the characteristics of soil erosion and redeposition pattern of sediment movements after rainfalls.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.772-776
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• 2001

The flow structures of turbulent shear layer behind oil fences with different tip configurations were investigated experimentally using flow visualization and PIV velocity field measurement. An oil fence was installed in a circulating water channel and the flow structure around the fence tip was mainly analyzed in this experiment. The four tip configurations tested in this experiment are knife edge; semi-circle edge, circular edge and rectangular edge. The 300 instantaneous velocity fields were measured using the single-frame PIV system and they were ensemble averaged to give the mean velocity field and spatial distribution of turbulent statistics. Free stream velocity was fixed at 10ms/sec and the corresponding Reynolds number based on the fence height was Re=4000. As a result, for the oil fence with rectangular edge, the streamwise velocity component was decreased. On the other hand it was increased for the oil fence with circular edge. For all four fences tested in this study, general flow pattern of the lower shear layer is analogous but the upper layer shows difference depending on the tip configurations. The oil fence with circular edge has more diffusive upper shear layer than that of the others. The shear layer of the oil fence with rectangular edge has relatively thin thickness. The oil fence with circular edge was found to be proper shape for tandem fence.

• Progress in Superconductivity
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• v.4 no.2
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• pp.114-120
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• 2003

We employed a method eliminating a temporally partial principal component (PC) of multichannel-recorded neuromagnetic fields for excluding spatially correlated noises from event-evoked signals. The noises in magnetoencephalography (MEG) are considered to be mainly spontaneous neuromagnetic fields which are spatially correlated. In conventional MEG experiments, the amplitude of the spontaneous neuromagnetic field is much lager than that of the evoked signal and the synchronized characteristics of the correlated rhythmic noise makes it possible for us to extract the correlation noises from the evoked signal by means of the general PC analysis. However, the whole-time PC of the fields still contains a little projection component of the evoked signal and the elimination of the PC results in the distortion of the evoked signal. Especially, the distortion will not be negligible when the amplitude of the evoked signal is relatively large or when the evoked signals have a spatially-asymmetrical distribution which does not cancel out the corresponding elements of the covariance matrix. In the period of prestimulus, there are only the spontaneous fields and we can find the pure noise PC that is not including the evoked signal. Besides that, we propose a method, called the extended temporal decorrelation method (ETDM), to suppress the distortion of the noise PC from remanent evoked signal components. In this study, we applied the Partial Principal component elimination method (PPCE) and ETDM to simulated signals and the auditory evoked signals that had been obtained with our homemade 37-channel magnetometer-based SQUID system. We demonstrate here that PPCE and ETDM reduce the number of epochs required in averaging to about half of that required in conventional averaging.

• Journal of the korean society of oceanography
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• v.39 no.1
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• pp.96-106
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• 2004

A total of 116 surface sediment samples were obtained on the Yellow Sea and analyzed for grain size and geochemical elements in order to interpret the present sediment transportation. Thirty-nine cores and 3,070 line-km shallow seismic profiles are analyzed for sedimentary records of Yellow Sea in the past. Results show that the boundary of sediment transport between Korean side and Chinese side is about between $123^{\circ}E$ and $124^{\circ}E$. The similar result is produced from Shi et al. (in this publication). Two cyclonic patterns of surface sediments are recognized in the northeastern and southwestern Yellow Sea, while the strong front zone of the mud patch and sandy sediments are found in the southeastern Yellow Sea (the southwestern part of Korean coasts). The formation of fine-particle sediment packages, called for Northwest Mudbelt Deposit (NWMD), Hucksan Mudbelt Deposit (HSMD) and Jeju Mudbelt Deposit (JJMD), are resulted from eddies (gyres) of water circulations in the Yellow Sea. NWMD has been formed by cyclonic (anticlockwise) eddy. NWMD is composed of thick, homogeneous, relatively semi-consolidated gray clay-dominated deposit. On the other hand, HSMD and JJMD are formed by anticyclonic (clockwise) eddies. They are thick, homogeneous, organic-rich gray, silt-dominated deposit. Both core and surface sediments show that the middle zone across Chinese and Korean side contains bimodal frequency of grain-size distribution, indicating that two different transport mechanisms exist. These mud packages are surrounded by sand deposits from both Korea and China seas, indicating that Yellow Sea, which is the shallow sea and epicontinental shelf, is formed mostly by sand deposits including relict sands. The seismic profiles show such as small erosional/non-depositional channels, sand-ridges and sand-waves, Pleistocene-channelfilled deposits, a series of channels in the N-S major channel system, and thick Holocene sediment package, indicating that more complex sedimentary history exists in the Yellow Sea.

• Progress in Superconductivity
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• v.7 no.1
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• pp.41-45
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• 2005

The diagnostic management of patients with chest pain remains a clinical challenge. Magnetocardiography (MCG) has been proposed as a new non-invasive method for detection of myocardial ischemia. To date, however, MCG technique is not intensively introduced for clinical use. One of the main reasons might be the absence of statistically valid and diagnostically clean criteria, which can determine the presence of certain heart disease. In this work, we suggested a new method to classify the diagnostic value of MCG for the detection of coronary artery disease (CAD) in patients with chest pain. MCG was recorded for three groups (healthy subjects and patients without and with CAD) by means of the 64 channel SQUID gradiometer system installed at a hospital. Using four parameters, which were found to be significantly different between groups, we evaluated a probability, in which parameters can be classified into each group based on the distribution function of the parameter in each group. For all parameters, sum of probabilities was compared between groups to determine the presence of CAD. Our classification method shows that the MCG can be a useful tool to predict the presence of CAD with sensitivity and specificity of higher than $80\%$ each.

• Journal of the Korea Convergence Society
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• v.9 no.9
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• pp.159-165
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• 2018

In this research, the researcher is seeking how to develop growing O2O food delivery platform service. The food delivery platform is newly creating the profit system which wasn't exist before by adding up IT and new technologies, and young generations who are used to mobile environment have became main consumers. For the methodology of research, internal and external delivery platform cases research is used to suggest the development idea. Food delivery platform market is showing an active development like business expansion by M&A of IT, distribution, manufacturing, circulation and it still has to attract the constant use of consumer through zero commission, discount events. Further research is required for various delivery platform channel and consumer's value of overall experience, above hereafter food delivery platform based on this research.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.13
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• pp.1013-1032
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• 2000

At present, the scale of Electronic Commerce through internet has been rapidly increasing due to the development of information & communication technology, and aggregated to 2.4 billion dollar in America last year (1998). The market scale of worldwide electronic commerce is also presumed to be about 130 billion dollar in 2000, and to occupy more than 20% of the whole world trade in world 2020. Since the right of trademark, despite of being effective only in registered nations on the principle of territorialism, is unified on the cyber space of internet without domestic barrier or local limitation which make it easier to conduct the distribution of information rapidly through the address-internet domain name, those are very important that the systematic dispute-solving plan on problems such as decision of its Act and international jurisdiction to be established, in an effort to prevent the newly emerging dispute instances such as trademark infringement and improper competitiveness. In addition, it is natural that on the threshold of the electronic commerce age which formed with an unified area without the worldwide specific regulation, each country including us makes haste with the enactment of "electronic commerce Act" aiming at coming into force in 1999, in keeping with getting through "non-tariff law on electronic commerce" by U. S. parliament on May, 1998. In view of the properties of electronic commerce transactions through internet, there are the large curtailment of distributive channel, surmounting of restrictions on transaction area, space and time and the easy feedback with consumer and the cheap-required capital, from which the problems may arise - registration of trademark, the trademark infringement of domain name and the protection of prestigious trademark. Therefore, it is necessary to take the counter-measure, with a view of reviewing the infringement of trademark and domain name and the instances of each national precedent and to preventing the disputes. The improvement of the persistent system should be needed to propel the harmonious protection of those holding trademark right's credit and demanders' expectant profit by way of the righteous use of trademark.