• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.4
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• pp.571-583
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• 2013

Internet banking service has a advantage that is unrestricted by time. If automated programs are able to attack Internet banking services, a number of accounts can be attacked at the same time and as a result, damage will be considerably increased. To cope with such attacks, two methods, VPS and MS watermark, were introduced by Arcot and MS respectively. The methods use text-based CAPTCHAs in the process of transfer approval to distinguish automated programs from legal human users. In this paper, we point out the security threats of the methods when those are applied to Internet banking services. Especially, we consider the attack that are performed by extract specific string from text-based CAPTCHAs and it's countermeasure. Also we suggest a method of enhancing security of internet banking services. Our method is based on contents-based CAPTCHAs that are consist of known transfer information between user and server.

• The Journal of Engineering Geology
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• v.18 no.1
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• pp.7-16
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• 2008

Limestone area have mostly certain geological defects such as the internal cavities due to melting and fractured zone by external pressures. Especially, in case of constructing grand bridge, the treatment of the limestone cavities area having the geological defects is inevitable. In order to reduce foundation settlement and to reinforce the ground in the limestone cavities area, high pressure jet grouting has been carried out as a countermeasure method. Despite the fact that high pressure jet grouting method has already adopted at a lot of limestone cavities area, but the amount of research and technical data on the high pressure jet grouting have not been accumulated properly so for. Therefore this paper intends to investigate the strength characteristics and deformation characteristics for reinforced limestone cavities area by high pressure jet grouting method. In addition, load carrying capacity obtained by static pile load test with load transfer measuring system is analyzed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.765-768
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• 2007

In this paper, the security evaluation method about mobile web services message is suggested in the method for improving the safety an reliability about the mobile web services message. In order that the goal of this paper is accomplished, the security threat and the security vulnerability which can be occurred in the mobile web services message are defined. The evaluation method for performing the security evaluation about the mobile web services message is defined. Also, the requirements for the mobile web services message security evaluation are defined. Finally, the evaluation framework for performing the mobile web services message security evaluation is constituted, and the evaluation scenario example is suggested. By using the mobile web services message security evaluation defined in the paper, before the mobile web services is deployed, the security threats and security vulnerability can be verified. Also, the countermeasure for the security threat and security vulnerability discovered in the verification result can be prepared. Therefore, the sorority and reliability about the mobile web services can be improved.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.10
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• pp.810-818
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• 2017

This paper presents the approaching target above ground tracking based on Kalman filter applied to the proximity sensor for the active defense system. The proximity sensor located on the front of the countermeasure is not easy to detect when the anti-tank threat enters a fragment dispersion range due to limited antenna beamwidth. In addition, it is difficult for the proximity sensor to detect the anti-tank threat accurately at a terrestrial environment including various clutters. To solve these problems, this study presents the approaching target above ground tracking based on Kalman filter and applies the novel estimation method for a noise covariance matrix to improve a tracking performance. Then, a high tracking performance of Kalman filter applied the proposed noise covariance matrix is presented through field firing test results and the validity of the proposed study is examined.

• Journal of the Institute of Convergence Signal Processing
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• v.15 no.4
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• pp.119-127
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• 2014

Recently, various methods derived from the experiences and the practices to manage knowledge have been proposed. However, the effects of the most of those methods have not been demonstrated quantitatively, but only the successful cases reported. In this paper, a method for knowledge transfer in a group is proposed to evaluate the effect of knowledge management and to express a shape that knowledge is transferred in the group by the multi-agent simulation. Simulation results show that the performance of the entire group is improved by introducing a knowledge database and a knowledge manager. In addition, the experience knowledge of the entire group is shown to be lost by reviewing results of the social issues by the proposed method. As a countermeasure for that, it was confirmed that the introduction of the knowledge database and the knowledge manager is more effective than those of an extension of the retirement age and of an increase of the intermediate recruitment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.11B
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• pp.1696-1703
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• 2010

Increased demand for military satellite communications system and due to the depletion of resources of existing satellite communications frequencies, Ka-band and EHF-band satellite communication systems is growing demand for development. As a result, the study of rain attenuation mitigation for Ka/EHF-band frequencies has been achieved. The method to compensate rain attenuation on Ka-band(20/30) using the signal power measurement function in Digital Transponder of Next Military Satellite has been proposed in this paper. This method is more effective than generally used method by Beacon and UPC(uplink power control) in giving the precise rain attenuation measurement and correction.

• Journal of Korea Water Resources Association
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• v.46 no.2
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• pp.99-109
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• 2013

Increasing complexity of the basin environments makes it difficult for single decision maker to consider all relevant aspects of problem, and thus the uncertainty of decision making grows. This study attempts to develop an approach to quantify the spatial flood vulnerability of South Korea. Fuzzy TOPSIS is used to calculate individual preference by each group and then three GDM techniques (Borda count method, Condorcet method, and Copeland method) are used to integrate the individual preference. Finally, rankings from Fuzzy TOPSIS, TOPSIS, and GDM are compared with Spearman rank correlation, Kendall rank correlation, and Emond & Mason rank correlation. As a result, the rankings of some areas are dramatically changed by the use of GDM techniques. Because GDM technique in regional vulnerability assessment may cause a significant change in priorities, the model presented in this study should be considered for objective flood vulnerability assessment.

• The Journal of Society for e-Business Studies
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• v.16 no.4
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• pp.97-108
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• 2011

Small IT service organizations operate their business with limited resources and workforce in comparison with large enterprises, and they could be categorized in various types based on the method of value creation. But the recent studies on information security have been conducted and they were focused on the construction of general information security countermeasure, without considering size of the business and characteristic. Hence we have undergone the process of classifying information assets. Then we extracted and categorized the information assets considering characteristics of small organization's size and business process. Specifically we have classified the information assets according to business scenario design through qualitative observation method. Then we have validated the classified information assets by utilizing statistical method. We may anticipate that this study results could be basic data for developing the differentiated information security countermeasures for small IT service organization.

• Journal of Korea Port Economic Association
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• v.19 no.2
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• pp.1-32
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• 2003

The purpose of this study is to identify and evaluate the competitiveness of ports in ASEAN(Association of Southeast Asian Nations), which plays a leading role in basing the hub of global logistics strategies as a countermeasure in changes of logistics environments. This region represents most severe competition among Mega Hub ports in the world in terms of container cargo throughput at the onset of the 21st century. The research method in this study accounted for overlapping between attributes, and introduced the HFP method that can perform mathematical operations. The scope of this study was strictly confined to the ports of ASEAN, which cover the top 100 of 350 container ports that were presented in Containerization International Yearbook 2002 with reference to container throughput. The results of this study show Singapore in the number one position. Even when we compare with major ports in Korea (after getting comparative ratings and applying the same data and evaluation structure), the number one position still goes to Singapore and then Busan(2) and Manila(2), followed by Port Klang(4), Tanjung Priok(5), Tanjung Perak(6), Bangkok(7), Inchon(8), Laem Chabang(9) and Penang(9). In terms of the main contributions of this study, it is the first empirical study to apply the combined attributes of detailed and representative attributes into the advanced HFP model which was enhanced by the KJ method to evaluate the port competitiveness in ASEAN. Up-to-now, none has comprehensively conducted researches with sophisticated port methodology that has discussed a variety of changes in port development and terminal transfers of major shipping lines in the region. Moreover, through the comparative evaluation among major ports in Korea and ASEAN, the presentation of comparative competitiveness for Korean ports is a great achievement in this study. In order to reinforce this study, it needs further compensative research, including cost factors which could not be applied to modeling the subject ports by lack of consistently quantified data in ASEAN.

• Journal of the Korea Society for Simulation
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• v.20 no.4
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• pp.21-29
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• 2011

Wireless sensor nodes operate in open environments. The deployed sensor nodes are very vulnerable to physical attacks from outside. Attackers compromise some sensor nodes. The compromised nodes by attackers can lead to false data injection into sensor networks. These attacks deplete the limited energy of sensor nodes. Ye et al. proposed the Statistical En-Route Filtering (SEF) as a countermeasure of the attacks. The sensor node in SEF examines the event reports based on certain uniform probability. Thus, the same energies are consumed in both legitimate reports and false reports. In this paper, we propose a method that each node controls the probability of attempts to verify a report to reduce energy consumption of sensor nodes. The probability is determined in consideration of the remaining energy of the node, the number of hops from the node to SINK node, the ratio of false reports. the proposed method can have security which is similar with SEF and consumes lower energy than SEF.