• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.527-531
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• 2003

Previous researches on scalability problem of distributed virtual environment (DVE) have been mainly focused on spatial partitioning of area of interest (AOI). Congestion phenomena by avatar groups in AOI have been neglected relatively. However, AOI congestion is highly related to scalability of DVT because it exhausts system resources such as network bandwidth and rendering time, and could be a bar to perform collaboration among participants. In this paper, this will be defined as the problem that must be solved for the realization of the scalable DVE, and a model will be proposed to measure and control congestion situation in AOI. The purposes of the proposed model are to prevent high density of participants in AOI, and to protect stable collaboration in DVE. For evaluation of the performance it is compared with a previous method by defining the resource cost model which is dynamically activated to AOI congestion.

• Journal of Navigation and Port Research
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• v.33 no.6
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• pp.415-421
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• 2009

Recently, the volume of transshipment containers in Busan Port has been declining significantly and domestic ports' throughput is shown far below the projected one. Accordingly, the national port development plan made to capture the sharply increasing demand in the past seems to be subject to an amendment, and inducing port container traffic becomes a key issue. In such situation this paper aims at analysing the effect of logistics cost saving when Japanese import and export containers are transshipped in Busan port. For this we developed 3 scenarios for the movement of containers through the major container ports in western cost of Japan, analysed logistics costs together with cost savings and finally derived some implication for inducing the containers to Busan Port.

• BMB Reports
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• v.42 no.3
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• pp.148-153
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• 2009

Pyrrolidine dithiocarbamate (PDTC) is a stable anti-oxidant or pro-oxidant, depending on the situation, and it is widely used to inhibit the activation of NF-${\kappa}B$. We recently reported that PDTC activates the MIP-2 gene in a NF-${\kappa}B$-independent and c-Jun-dependent manner in macrophage cells. In this work, we found that PDTC activates signal transduction pathways in mouse ES cells. Among the three different mitogen-activated protein kinase (MAPK) pathways, including the extracellular-signal-regulated kinase (ERK), p38 MAP kinase, and stress-activated protein kinase (SAPK)/Jun N-terminal kinase (JNK) pathways, only the ERK pathway was significantly activated in mouse ES cells after stimulation with PDTC. Additionally, we observed a synergistic activation of ERK and induction of c-Fos after stimulation with PDTC in the presence of mouse embryonic fibroblast (MEF) conditioned medium. In contrast, another NF-${\kappa}B$ inhibitor, BMS-345541, did not activate the MAP kinase pathways or induce expression of c-Fos. These results suggest that changes in the presence of the NF-${\kappa}B$ inhibitor PDTC should be carefully considered when it used with mouse ES cells.

• Journal of Korea Water Resources Association
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• v.46 no.3
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• pp.287-299
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• 2013

The objective of this study is to derive and evaluate the drought threshold level based on hydro-meteorological data using historical drought events. After collecting the drought events during 1991 to 2009 year, the observed meteorological data and estimated hydrological component from LSM are used as input for the percentile analysis that is drought analysis data. The drought threshold level that precipitation and runoff of 3 month duration are less than 35%, soil moisture of 2 month duration is less than 35% and evapotranspiration of 3 month duration is more than 65% is derived using ROC analysis that are objective test method. ROC analysis with SPI (3) is performed to evaluate the applicability of threshold level in the domestic. As a result, it can be concluded that the derived drought threshold level show better performance to reflect the historical drought events than SPI (3) and it reasonably explain the spatial drought situation through the spatial analysis.

• Journal of the military operations research society of Korea
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• v.32 no.1
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• pp.13-35
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• 2006

This study aims to propose alternative suggestions for practical and efficient implementation of Dual Use Technology Programs(CUTP) in Korea which can strengthen both national security and industrial competitiveness. DUTP of Korea has suffered from inefficiency and inactivity. This study analyzes the Inefficiency and negative factors of DUTP of Korea by examining the previous cases of the advanced countries. It also examines individual problems of DUTP carefully and attempts to derive alternative solutions to improve the current situation. First, a global government plan should be made considering Korea's weapon system and Korea's industrial characteristics. Second, DUTP should begin to develop core technology in connection with technology level evaluation and technology exchange project should establish a comprehensive information network system which links any civilian and military technology data. Third, technology transfer project should be promoted by utilizing cyber technology exchange market and military defense venture center. Fourth, standardization project should be expanded by establishing a national standard information system.

• The KIPS Transactions:PartC
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• v.12C no.6 s.102
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• pp.855-864
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• 2005

In this paper, we propose an intrusion detection system(IDS) architecture which can detect and respond against the generation of abnormal traffic such as malicious code and Internet worms. We model the system, design and implement a simulator using OPNET Modeller, for the performance analysis on the response capacity of alert information in the proposed system. At first, we model the arrival process of alert information resulted from abnormal traffic. In order to model the situation in which alert information is intensively produced, we apply the IBP(Interrupted Bernoulli Process) which may represent well the burstiness of traffic. Then we perform the simulation in order to gain some quantitative understanding of the system for our performance parameters. Based on the results of the performance analysis, we analyze factors which may hinder in accelerating the speed of security node, and would like to present some methods to enhance performance.

• Journal of KIISE:Databases
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• v.27 no.1
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• pp.13-21
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• 2000

Online analytical processing (OLAP) systems are introduced to support decision support systems. Many researches focussed on efficient processing of aggregate functions that usually occur in OLAP queries. However, most previous researches in the literature are deal with the situation in which aggregate functions arc applied to all the values in a given range. Since those approaches utilize characteristic of aggregate functions applied to a range, they are difficult to be applied to a muitipoint query that is a query considering only some points in a given range. In this paper, we propose the Ranking Index and the flanking Decision Tree (RDT) for efficient evaluation of multipoints MAX/MIN queries. The ranking of possible MAX/MIN values are computed with RDT Then MAX/MIN values can be acquired from the Ranking Index. We show through experiments that our method provides high performance in most situations. In other words, the proposed method is robust as well as efficient. A single common set of precomputed results for both MAX and MIN values is another advantage of the proposed method.

• Journal of Digital Convergence
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• v.15 no.3
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• pp.295-300
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• 2017

The purpose of this study is to analyze the EBS special lecture, which is an educational application, from a user 's point of view and to propose a direction for improvement of the user experience according to the GUI design. Firstly, we surveyed the theoretical background and service situation through literature review, and secondly, we surveyed the user experience questionnaire based on 7 principles of honeycomb model of Peter Morville. As a result, the EBS special lecture showed improvement of GUI due to lack of visual part in addition to its use. Based on this research, I hope that the service for improvement of the user experience of the education application will be improved in the future and it will be helpful to study the educational application user experience to be conducted in the future.

• Archives of design research
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• v.14 no.2
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• pp.175-185
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• 2001

This study is concerned about the meaning of space-direction in environmental design and its form for examples of Javacheff Christo's works. As environmental design that space-direction is very important thing, but it is difficult to find some concreted style. Even more there are greatly indistinct in the boundary between environmental art and environmental design. Studying on Cristo's work which is valuable way of using space-direction. We will applicate for needful methods in environmental design. Christo's works are divided three boundary. ai. environmental wrapping, environmental installation, environmental partition. His way of space-direction that is dramatic, participating in process, concentrating in place-specific, and various way of utilizing object. It is meaningful study that survey to Christo's works. They present as environmentally directing object, showing situation, and building experience of space. So it is possible to judge the evaluation of his works. Finally, space-direction that finding in Christo's work is very useful way in environmental design process.

• Journal of Korean Foot and Ankle Society
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• v.7 no.1
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• pp.95-100
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• 2003

Purpose: To evaluate the incidence, contributing factors, and clinical results of refracture of proximal 5th metatarsal stress fracture treated operatively in athletes Materials and Methods: This study included 8 patients who had been treated for refracture of proximal 5th metatarsal stress fracture with operaton. Their charts & radiologic findings were evaluated retrospectively. Results: The overall incidence of refracture was 13%. Main contributing factors were time of return to sports activity and associated deformities such as cavus foot or flat foot. Seven cases were managed with nonoperative treatment, and we added percutaneous pin fixation under local anesthesia in one case. Bony union was seen at average 8. 5 weeks in 7 cases except 1 nonunion and all of 8 patient returned to athletics at average 16 weeks. Conclusion: The incidence of refracture of proximal 5th metatarsal stress fracture treated operatively in athletes was relatively high. Time of rerum to sports activity must be decided very carefully on individual situation and further imaging study may be helpful for bony union evaluation. The non-operative treatment may have a good result if bone graft was done initially.