• The Journal of the Korea Contents Association
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• v.13 no.8
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• pp.160-170
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• 2013

The present study analyzes a Twitter network of some 175 government organizations belonging to seven countries. They are South Korea, U.S., U.K., Australia, Canada, Singapore, and Japan. The results showed that the U.S. occupied the most central position in terms of the incoming followings. Next, some clusters among countries were also noticeable according to their cultural proximities including national languages. The findings also indicate that some governmental organizations are likely to make international ties with others whose main duties are similar to each other. Finally, the structural connectivity pattern of some inter-governmental Twitter networks was visualized using a social network software. On the other hand, it suggests that there is a potential for a soft power through social media and as a result, it could be assumed that a new knowledge hegemony appears in the future.

• Journal of Navigation and Port Research
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• v.36 no.1
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• pp.51-58
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• 2012

In spite of today's rapid growth of world cruise industry, little academic attention has yet been given to the decision making problems for cruise operations. This research deals with strategic cruise itinerary planning that any cruise company should face. Increasing demands for international itineraries and redeployments of cruise ships are adding complexity to the itinerary planning. A slight modification of the conventional PERT/CPM network is adopted. to cope with this complexity systematically. By this, the concept of candidate itinerary network is suggested for each cruise ship. To integrate these candidate itinerary networks for each ship in a single framework, an integer programming model has been developed to find the optimal itinerary planning for any fleet of cruise ships. A numerical example, based on real cruise itinerary practices, is tested to validate and interpret the model.

• KIEE International Transactions on Power Engineering
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• v.5A no.4
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• pp.357-365
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• 2005

This research investigates the influences of distributed generations (DG), which are interconnected to the bus by the dedicated lines, on the overcurrent relays (OCR) of the neighboring distribution feeders and also proposes a novel method to reduce the negative effects on the feeder protection. Due to the grid connected DG, the entire short-circuit capacity of the distribution networks increases, which may raise the current of the distribution feeder during normal operations as well as fault conditions. In particular, during the switching period for loop operation, the current level of the distribution feeder can be larger than the pickup value for the fault of the feeder's OCR, thereby causing the OCR to perform a mal-operation. This paper proposes the adaptive setting algorithm for the OCR of the distribution feeders having the neighboring dedicated feeders for the DG to prevent the mal-operations of the OCR under normal conditions. The proposed method changes the pickup value of the OCR by adapting the power output of the DG monitored at the relaying point in the distribution network. We tested the proposed method with the actual distribution network model of the Hoenggye substation at the Korea Electric Power Co., which is composed of five feeders supplying the power to network loads and two dedicated feeders for the wind turbine generators. The simulation results demonstrate that the proposed adaptive protection method could enhance the conventional OCR of the distribution feeders with the neighboring dedicated lines for the DG.

• International Journal of Highway Engineering
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• v.13 no.1
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• pp.197-206
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• 2011

The Korean government concentrates on supplying public transit facilities for the mobility handicapped. In other hands, increasing needs of transfer information when the mobility handicapped use transit facilities are substantial but not satisfactory as a whole. This study focuses on evaluating the applicability of developed K-path algorithm to provide user-customized route information that could make an active using of public transit while considering the mobility handicapped preferences. Developed algorithm reflects on requirements considering transfer attributes of the mobility handicapped. Trip attributes of the handicapped are addressed distinguished from handicapped types such as transfer walking time, transfer ratio, facility preferences and etc. This study examines the verification and application of the proposed algorithm that searches the least time K-paths by testing on actual subway networks in Seoul metropolitan areas. It is shown that the K-path algorithm is good enough to provide paths that meet the needs of the mobility handicapped and to be adoptable for the future expansion.

• Journal of Arbitration Studies
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• v.11 no.1
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• pp.37-73
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• 2001

I. Preface It is widely understood that the 21st century, with the development of information technology(IT) and the spread of networks, will be called a digital economy where information-driven business will be norm rather than the smokestack economy of the past. And the drastically changed world market is expected to generate even more commercial transactions across the world creating large numbers of legal disputes. Therefore, each country will attempt to develop ADR(Alternative Dispute Resolution) as an alternative to judicial proceedings in order to cope with not only the ever-increasing international commercial claims but also domestic legal disputes. Taking this reality into account, this study begins with an exploration of mediation procedure as a way of helping the court faced with its overwhelming numbers of lawsuits. And also this study makes a theoretical comparison between ADR and mediation procedure, analyzing critical factors affecting the mediation agreement. Furthermore, it is designed to find ways for disputing parties to make better use of mediation and ensure fairness to the parties involved. It tries to enhance mediators' understanding of critical factors influencing the mediation agreement and their ability to handle commercial disputes in a more efficient way. To make an empirical analysis of these factors, bibliographic research and questionnaire were used. This analysis will fill the gap between the theory and reality, and make possible the structured research on the factors. Therefore, this study sets the model by which we can evaluate how the three critical factors (parties' inclination, mediators' characteristics, institutional features) affect the parties reaching a mediation agreement. Based on this analysis, a theoretical hypothesis was built and a questionnaire was made and distributed. During the course of this work, SPSSWIN 10.0 program was applied.

• Journal of Ecology and Environment
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• v.33 no.4
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• pp.377-389
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• 2010

Understanding the factors relevant to endangerment and the patterns of habitat locations in relation to protected areas is critically important for the conservation of rare species. Although 64 plant species have recently been listed as endangered species in Korea, this information has, until now, not been available, making appropriate management and conservation strategies impossible to devise. Thus, we collected information on potentially threatening factors, as well as information on the locations in which these species were observed. The potentially threatening factors were classified into seven categories. National parks, provincial parks, ecosystem conservation areas, and wetland conservation areas were defined as protected conservation areas. Korean digital elevation model data, along with the maps of all protected areas were combined with the maps of endangered plant species, and analyzed via Geographic Information Systems (GIS). Excluding the category of "small population", endangered plant species in Korea were associated more frequently with extrinsic factors than intrinsic factors. Considering land surface only, all conservation areas in Korea totaled 4.9% of the land, far lower than International Union for Conservation of Nature and Natural Resources (IUCN)'s 10% coverage target. At the species level, 69% of the endangered plant species were detected in conservation areas, mostly in national parks. However, this result demonstrates that 31% of endangered species inhabit areas outside the conservation zones. Furthermore, at the habitat level, a large proportion of endangered species were found to reside in unprotected areas, revealing "gaps" in protected land. In the face of rapid environmental changes such as population increases, urbanization, and climate changes, converting these gap areas to endangered species' habitats, or at least including them in habitat networks, will help to perpetuate the existence of endangered species.

• Journal of Environmental Science International
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• v.18 no.2
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• pp.129-139
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• 2009

Development of an artificial neural network model was presented to predict the daily maximum $SO_2$ concentration in the urban-industrial area of Ulsan. The network model was trained during April through September for 2000-2005 using $SO_2$ potential parameters estimated from meteorological and air quality data which are closely related to daily maximum $SO_2$ concentrations. Meteorological data were obtained from regional modeling results, upper air soundings and surface field measurements and were then used to create the $SO_2$ potential parameters such as synoptic conditions, mixing heights, atmospheric stabilities, and surface conditions. In particular, two-stage clustering techniques were used to identify potential index representing major synoptic conditions associated with high $SO_2$ concentration. Two neural network models were developed and tested in different conditions for prediction: the first model was set up to predict daily maximum $SO_2$ at 5 PM on the previous day, and the second was 10 AM for a given forecast day using an additional potential factors related with urban emissions in the early morning. The results showed that the developed models can predict the daily maximum $SO_2$ concentrations with good simulation accuracy of 87% and 96% for the first and second model. respectively, but the limitation of predictive capability was found at a higher or lower concentrations. The increased accuracy for the second model demonstrates that improvements can be made by utilizing more recent air quality data for initialization of the model.

• Journal of Environmental Science International
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• v.22 no.9
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• pp.1199-1211
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• 2013

Mobile sources produce a significant fraction of total anthropogenic emissions in Korea and have harmful effects on air quality. Mobile emissions are intrinsically difficult to estimate due to complicated road networks and variations of traffic volume with location and time. To measure traffic pollutants with high temporal and spatial resolution under real conditions a mobile laboratory was designed. The mobile laboratory provide concentrations of $SO_2$, CO, NO, $NO_2$ and location coordinate value. This approach allowed for pollutant level measurements on many roads within short periods of time. In this study, on-road concentrations of $SO_2$, CO, NO and $NO_2$ were measured using mobile platform measurement along the 25 main roads in Busan to estimate the average air pollution level in short time difference. The measurements were conducted on favorable meteorological days from 2010 to 2012 and the overall concentrations of $SO_2$, CO, NO and $NO_2$ were 0.006, 0.8, 0.182 and 0.055 ppm respectively. The result showed that the concentration of CO, NO and $NO_2$ on road were twice, 18 times and 2.5 times higher than regional air quality monitoring sites mean in same period.

• Journal of Environmental Science International
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• v.22 no.6
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• pp.651-666
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• 2013

This study introduces a novel approach to the differentiation of two phenomena, Asian Dust and haze, which are extremely difficult to distinguish based solely on comparisons of PM10 concentration, through use of the Optical Particle Counter (OPC), which simultaneously generates PM10, PM2.5 and PM1.0 concentration. In the case of Asian Dust, PM10 concentration rose to the exclusion of PM2.5 and PM1.0 concentration. The relative ratios of PM2.5 and PM1.0 concentration versus PM10 concentration were below 40%, which is consistent with the conclusion that Asian Dust, as a prime example of the coarse-particle phenomenon, only impacts PM10 concentration, not PM2.5 and PM1.0 concentration. In contrast, PM10, PM2.5 and PM1.0 concentration simultaneously increased with haze. The relative ratios of PM2.5 and PM1.0 concentration versus PM10 concentration were generally above 70%. In this case, PM1.0 concentration varies because a haze event consists of secondary aerosol in the fine-mode, and the relative ratios of PM10 and PM2.5 concentration remain intact as these values already subsume PM1.0 concentration. The sequential shift of the peaks in PM10, PM2.5 and PM1.0 concentrations also serve to individually track the transport of coarse-mode versus fine-mode aerosols. The distinction in the relative ratios of PM2.5 and PM1.0 concentration versus PM10 concentration in an Asian Dust versus a haze event, when collected on a national or global scale using OPC monitoring networks, provides realistic information on outbreaks and transport of Asian Dust and haze.

• International Journal of Internet, Broadcasting and Communication
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• v.8 no.2
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• pp.49-54
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• 2016

Data delivery is very challenging in VANETs because of its unique characteristics, such as fast topology change, frequent disruptions, and rare contact opportunities. This paper tries to explore the scope of 3G-assisted data delivery in a VANET within a budget constraint of 3G traffic. It is started from the simple S_Random (Srand) and finally reached the 3GSDD, i.e., the proposed algorithm. The performance evaluation of different algorithms is done through the two metrics delivery ratio and average delay. A third function utility is created to reflect the above two metrics and is used to find out the best algorithm. A packet can either be delivered via multihop transmissions in the VANET or via 3G. The main challenge is to decide which set of packets should be selected for 3G transmissions and when to deliver them via 3G. The aim is to select and send those packets through 3G that are most sensitive and requiring immediate attention. Through appropriate communication mechanism, these sensitive information are delivered via VANET for 3G transmissions. This way the sensitive information which could not be transmitted through normal VANET will certainly find its destination through 3G transmission unconditionally and with top priority. The delivery ratio of the packets can also be maximized by this system.