• KIISE Transactions on Computing Practices
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• v.23 no.12
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• pp.691-697
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• 2017

Volcanic ash has been predicted to be the main source of damage caused by a potential volcanic disaster around Mount Baekdu and the regions of the Korean peninsula. Computer simulations to predict the diffusion of volcanic ash should be performed according to prevalent meteorological situations within a predetermined time. Therefore, a workflow using pipelining is proposed to parallelize the software used for this computation. Due to the nature of volcanic calamities, the simulations need to be carried out for various plausible conditions given that the parameters cannot be precisely determined during the simulations, even at the time of a volcanic eruption. Among the given conditions, computations need to be first performed for the condition with the highest probability so that a response to the volcanic disaster can be provided using these results. Further action can then be performed later based on subsequent results. The computations need to be performed using a volcanic disaster damage prediction system on a computing server with limited computing performance. Hence, an optimal distribution of the computing resources is required. We propose a method through which specific data can be provided first to the proposed pipeline-based workflow.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.6
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• pp.73-83
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• 2015

The objective of this study is to establish implications for forest restoration planning in North Korea by analyzing spatio-temporal forest changes and detecting bio-physical factors driving forest degraded. We measured the relationship and spatial distribution between shifting cultivation and sparse forest. We also analyzed between degraded forest land and ecological variables by binary logistic regression to find biophysical drivers of forest degradation and deforestation in North Korea. Between the sparse forest and the shifting cultivation, a positive relationship is found (r=0.91) and scattered discontinuously throughout the country (Moran's I = -1, Z score = -13.46 (p=0.000)). The sparse forest showed a negative relationship with the warmest month(bio 9), the coldest month(bio10), and the minimum of soil water contents (swc_min), while the shifting cultivation had a negative relationship with the warmest month(bio 9) and the minimum of soil water contents(swc_min). However, the most critical drivers convert forests into sloping farmland were the three months rainfall in summer(bio8) and the yearly mean of soil water contents. Such results reflect the growth period of crops which overlaps with the rainy season in North Korea and the recent land reclamation of uplands where the soil water contents are maintained with a dense forest. When South Korea aids forest restoration projects in North Korea, in consideration of food shortage due to North Korea's cropland deficiency, terrace farmlands where soil water contents can be maintained should be excluded from the priority restoration area. In addition, an evaluation method for selecting a potential restoration area must be modified and applied based on multiple criteria including altitude and socio-economic factors in the respective regions.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.6
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• pp.627-636
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• 2010

Image segmentation technique is becoming increasingly important in the field of remote sensing image analysis in areas such as object oriented image classification to extract object regions of interest within images. This paper presents a new method for image segmentation to consider spectral and spatial information of high resolution satellite image. Firstly, the initial seeds were automatically selected using local variation of multi-spectral edge information. After automatic selection of significant seeds, a segmentation was achieved by applying MSRG which determines the priority of region growing using information drawn from similarity between the extracted each seed and its neighboring points. In order to evaluate the performance of the proposed method, the results obtained using the proposed method were compared with the results obtained using conventional region growing and watershed method. The quantitative comparison was done using the unsupervised objective evaluation method and the object-based classification result. Experimental results demonstrated that the proposed method has good potential for application in the object-based analysis of high resolution satellite images.

• Proceedings of the KSRS Conference
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• v.1
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• pp.29-33
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• 2006

The potential impact of past Caribbean tsunamis generated by earthquakes and/or massive submarine slides/slumps, as well as the tsunamigenic potential and population distribution within the Intra-Americas Sea (IAS) was examined to help define the optimal location for coastal sea level gauges intended to serve as elements of a regional tsunami warning system. The goal of this study was to identify the minimum number of sea level gauge locations to aid in tsunami detection and provide the most warning time to the largest number of people. We identified 12 initial, prioritized locations for coastal sea level gauge installation. Our study area approximately encompasses $7^{\circ}N$, $59^{\circ}W$ to $36^{\circ}N$, $98^{\circ}$ W. The results of this systematic approach to assess priority locations for coastal sea level gauges will assist in developing a tsunami warning system (TWS) for the IAS by the National Oceanic and Atmospheric Administration (NOAA) and the Intergovernmental Oceanographic Commission's Regional Sub-Commission for the Caribbean and Adjacent Regions (IOCARIBE-GOOS).

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.2
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• pp.103-112
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• 2016

As supply chains are globalized, multinational companies are trying to optimize distribution networks using a hub and spoke structure. In this hub and spoke network structure, multinational companies locate regional distribution centers at hub airports, which serve demands in their corresponding regions. Especially when customers put higher priority on the service lead-time, hinterlands of international hub airports become ideal candidate locations for the regional hub distribution centers. By utilizing excellent airport and logistics services from hub airports, regional distribution centers in the hub airports can match supply with demand efficiently. In addition, regional hub distribution centers may increase air cargo volume of each airport, which is helpful in the current extremely competitive airport industry. In this paper, we classified locational preferences into three primary categories including demand, service and risk and applied the analytic hierarchy process methodology to prioritize factors of locational preferences. Primary preference factors include secondary factors. Demand factor contains access to current and prospect markets. Service factor comprises airport and logistics perspectives. Service factor in terms of airport operations includes secondary factors such as airport service and connectivity. Service factor in terms of logistics operations contains infrastructure and logistics operations efficiency. Risk factor consists of country and business risks. We also evaluated competitiveness of Asian hub airports in terms of candidate location for regional hub distribution centers. The candidate hub airports include Singapore, Hong Kong, Shanghai, Narita and Incheon. Based on the analytic hierarchy process analysis, we derived strategic implications for hub airports to attract multinational companies' regional hub distribution centers.

• Journal of Ocean Engineering and Technology
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• v.32 no.3
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• pp.184-191
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• 2018

Recently, as sea ice in the Arctic has been decreasing due to global warming, it has become easier to develop oil and gas resources buried in the Arctic region. As a result, Russia, the United States, and other Arctic coastal states are increasingly interested in the development of oil and gas resources, and the demand for offshore structures to support Arctic sea resources development is expected to significantly increase. Since offshore structures operating in Arctic regions need to secure safety against various drifting ice conditions, the concept of an ice-strengthened design is introduced here, with a priority on calculation of ice load. Although research on the estimation of ice load has been carried out all over the world, most ice-load studies have been limited to estimating the ice load of the icebreaker in a non-oblique state. Meanwhile, in the case of Arctic offshore structures, although it is also necessary to estimate the ice load according to oblique angles, the overall research on this topic is insufficient. In this paper, we suggest algorithms for calculating the ice load of managed ice (pack ice, 100% concentration) in an oblique state, and discuss validity. The effect of oblique angle according to estimated ice load with various oblique angles was also analyzed, along with the impact of ship speed and ice thickness on ice load.

• Journal of Microbiology
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• v.43 no.2
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• pp.133-143
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• 2005

Shigellosis is a global human health problem. Four species of Shigella i.e. S. dysenteriae, S. flexneri, S. boydii and S. sonnei are able to cause the disease. These species are subdivided into serotypes on the basis of O-specific polysaccharide of the LPS. Shigella dysenteriae type 1 produces severe disease and may be associated with life-threatening complications. The symptoms of shigellosis include diarrhoea and/or dysentery with frequent mucoid bloody stools, abdominal cramps and tenesmus. Shigella spp. cause dysentery by invading the colonic mucosa. Shigella bacteria multiply within colonic epithelial cells, cause cell death and spread laterally to infect and kill adjacent epithelial cells, causing mucosal ulceration, inflammation and bleeding. Transmission usually occurs via contaminated food and water or through person-to-person contact. Laboratory diagnosis is made by culturing the stool samples using selective/differential agar media. Shigella spp. are highly fragile organism and considerable care must be exercised in collecting faecal specimens, transporting them to the laboratories and in using appropriate media for isolation. Antimicrobial agents are the mainstay of therapy of all cases of shigellosis. Due to the global emergence of drug resistance, the choice of antimicrobial agents for treating shigellosis is limited. Although single dose of norfloxacin and ciprofloxacin has been shown to be effective, they are currently less effective against S. dysenteriae type 1 infection. Newer quinolones, cephalosporin derivatives, and azithromycin are the drug of choice. However, fluoroquinolone-resistant S. dysenteriae type 1 infection have been reported. Currently, no vaccines against Shigella infection exist. Both live and subunit parenteral vaccine candidates are under development. Because immunity to Shigella is serotype-specific, the priority is to develop vaccine against S. dysenteriae type 1 and S. flexneri type 2a. Shigella species are important pathogens responsible for diarrhoeal diseases and dysentery occurring all over the world. The morbidity and mortality due to shigellosis are especially high among children in developing countries. A recent review of literature (KotIoff et al.,1999) concluded that, of the estimated 165 million cases of Shigella diarrhoea that occur annually, $99\%$ occur in developing countries, and in developing countries $69\%$ of episodes occur in children under five years of age. Moreover, of the ca.1.1 million deaths attributed to Shigella infections in developing countries, $60\%$ of deaths occur in the under-five age group. Travellers from developed to developing regions and soldiers serving under field conditions are also at an increased risk to develop shigellosis.

• The Journal of the Korea Contents Association
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• v.6 no.1
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• pp.41-53
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• 2006

In this paper, an adaptive ROI(region of interest) detection system for spatialtemporal features is proposed. It utilizes spatiotemporal features for the purpose of detecting ROI. It is assumed that motion representing temporal visual conspicuity between adjacent frames takes higher priority over spatial visual conspicuity. Because objects or regions in motion usually draw stronger attention than others in motion pictures. In case of still images visual features that constitute topographic feature maps are used as spatial features. Comparative experiments with a human subjective evaluation show that correct detection rate of visual attention region is improved by exploiting both spatial and temporal features compared to the case of exploiting either feature.

• Journal of Korean Society on Water Environment
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• v.28 no.3
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• pp.444-452
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• 2012

This study aims at assessing vulnerability of water quality and aquatic ecosystem to climate change by using proxy variables. Vulnerability to climate change is defined as a function of exposure to climate, sensitivity, and adaptive capacity. Detailed proxy variables were selected considering availability and then standardized by re-scaling concept. After adequate weights were assigned to standardized proxy variables by Delphi technique, vulnerability index was calculated. As results, vulnerability of adjacent regions to coastal areas include water quality and aquatic ecosystem is relatively higher than that of inland areas, and especially adjacent region to the western and southeast seas, and Jeju show high vulnerabilities. Vulnerability in the future was performed based on A1B scenario (IPCC, 2000). Temporally, the increase of vulnerability from 2050s to 2100s may be larger than the increase from 2000s to 2050s. Because vulnerability index was estimated through the relationship among various proxy variables, it is important to consider characteristics of local region with measurements and policies for reduction of sensitivity and enhancement of adaptive capacity on climate change. This study is expected to be useful in planning adaptation measures and selecting priority to the policy on climate change.

• Journal of Korea Port Economic Association
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• v.27 no.2
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• pp.39-57
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• 2011

Recently Incheon Port and Pyeongtak·Dangjin Port called as Capital Region Ports have enjoyed ever-increasing cargo volumes. However, there is a lack of research on this region while plenty of outputs were suggested on mega hub and regional hub ports in terms of shipping companies and stakeholders' port choice criteria. To identify and evaluate the Capital Region Ports, this paper identifies the factors and sub-components influencing their port choice and presents a structure for evaluating them. Based on the literature related to port selection and competition, a regional survey employed Factor Analysis to reveal that 'port facility and link', 'cost and service', 'port hinterland' and 'information service and port operation policy' are the determining factors in these regions. From the overall evaluation using Fuzzy Theory, Port of Incheon Port obtained high score compare to that of Port of Pyeongtak Dangjin.