• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.6
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• pp.148-156
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• 2018

The integrity assessment of the bridge behavior is generalized by field data of a static load-deformation curve and dynamic properties such as impact factors and natural frequencies. Evaluating it with numerical analysis is a reasonable method. The results of the mockup test and the numerical analysis are corresponded with each other since the behavior of service load proceeds in elastic region. In case of the dynamic behavior of structure, especially for the analysis of vibration, the result of the mockup test differs from the result of numerical analysis a little due to the geometric shape and non-homogeneous materials. In order to converge on these tolerances, this study suggested several numerical models, analyzed the sensitivity and finally offered a practical modeling method for the estimation of bridge on the basis of the result of mockup test. Based on the model substituted concrete section for strands section, the natural frequency of the model composed with axial stiffness of strands or the model applied the modified modulus of elasticity was closest with the result of the mockup test.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.48-54
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• 2020

DMSMS (Diminishing Manufacturing Sources and Material Shortage) is increased by developing the scientific technique and downsizing the military part market. DMSMS affects the increase in total life cycle costs and serviceability. Therefore, advance control for parts is important to reduce the cost, and a database is needed to share information on the DMSMS. A task needs to be performed continuously by setting the major control item to management more efficiently. The purpose of this study was to deduce the major control item for the DMSMS management system. Thus, the pre-control item basis of the DAPA (Defense Acquisition Program Administration) Manual and the SD-22 Manual were first selected, and the results of the survey were analyzed by AHP (Analytic Hierarchy Process) method. Fifteen of the detailed items were stratified into three criteria (Impact, Probability, and cost of the DMSMS), and each weight for the items was calculated using a nine-point scale survey. The AHP survey was executed with 25 specialists in the DMSMS management field, and the score of consistency ratio over 0.1 was excluded. The model explained the results and suggested future directions for development.

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.2
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• pp.94-102
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• 2023

The Florence Charter, established in 1981 by the ICOMOS-IFLA International Commission on Historic Gardens, considered the historic garden as a plant-dominated architectural composition, a perpetual balance between the artist and the artisan's desire to remain unaltered in perpetuity. Trees, the main component of the garden, require continuous management as they repeat their creation and calling according to the cycle of the seasons and accordingly, it is suggested that management to maintain the appearance of trees in Korean palaces was an indispensable element. Although it is an important matter to historically verify the tree management techniques of the palaces of the past, research has been difficult due to the absence of historical records and the disconnection of life due to the Japanese colonial period. In addition, according to the view that trees were not generally managed in the palace, research on palace tree management techniques has not been conducted so far. Therefore, this study aimed to examine whether or not the tree management of the palaces was performed in the past through expert interviews based on photographs taken in modern times. With the identification of tree species and pruning through in-depth interviews with experts using photographs taken in the modern period, the results are as follows. First, it was found that the shapes of trees and leaves could be identified through photographs and by observing the phenomena caused by planting and pruning, it was possible to estimate whether or not the tree management was implemented in the modern palace. Second, as a result of in-depth interviews with 8 experts in 4 fields, it was possible to determine the tree species and pruning status, purpose, and method. There was no significant difference in opinions between groups, and the evidence was clearly presented. Third, the type of management of trees in the palace was mainly found to be determination of the types of tree, removal of hazardous factors of trees, and management of lower vegetation and through the photographs of Jondeokjeong and Gwanwanjeong, it was confirmed that the trees were managed even before the Japanese colonial era, considering the time of filming. Based on the photographs taken, it was possible to estimate whether the trees were managed before the Japanese colonial period through expert interviews. However, it could not be clarified due to lack of historical materials as to whether it was carried out on its own according to the circumstances of the times or by the Japanese Empire. Still, in this study, evidence was obtained to refute the view that trees of the palace were not managed in the past through the collected data. Expert opinions supporting this view were collected to make the conclusion. In addition, based on the general theory of pruning, an empirical review of expert opinions was conducted to secure the reliability of the research results.

• Journal of the Korean Society for information Management
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• v.30 no.2
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• pp.101-118
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• 2013

The purpose of this study is to reveal their satisfaction procedures from users of information service expectation-disconfirmation theory. To achieve this goal, we use the NDSLQual model to measure the quality of NDSL service. The results were as follows: First, while the expectation has a negative effect on the expectation-disconfirmation, it has a positive effect on the perceived performance. And perceived performance has a positive effect on the expectation-disconfirmation. Second, the expectation-disconfirmation has a positive effect on the overall satisfaction and loyalty. However the explanatory adequacy of the regression model is very low. Third, perceived performance has a positive effect on the overall satisfaction and loyalty. In order to increase the overall satisfaction and loyalty for NDSL, it is necessary to seek ways to improve the perceived performance and lower the expectation-disconfirmation.

• The Journal of the Korea Contents Association
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• v.18 no.4
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• pp.10-17
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• 2018

Most of the privacy officers of organizations are hard to think of the corrective action about deficiencies of the PIMS(Personal Information Management Systems) certification. Because, it is difficult to define the priority of the complementary measures due to the unique characteristics and procedures of personal information protection for each organization. The purpose of this study is to evaluate the priority of the complementary measures using the Analytic Hierarchy Process(AHP). According to the results, it is important to comply with the legal requirements in the first tier. The second tier, PIMS experts answered that dedicated organization, password management, and agreement of the subject are important. Above all, agreement of the subject was found the highest priority for complementary measures about PIMS's deficiencies.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3B
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• pp.263-269
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• 2006

An optimization model was developed for groundwater development and management in coastal areas. The optimization model consists of coastal groundwater flow model and optimization techniques. The objective of this work is to validate sharp-interface model which is one of major components of the optimization model. A laboratory experimental model is built to simulate freshwater lens, i.e., layer of freshwater floating on top of saltwater, phenomena. Experimental results for the position of fresh-saltwater sharp-interface and the salinity in well are compared with numerical results. Average ratio of relative error is estimated approximately between 2.91% and 4.39%. And the numerical results are in good agreement with the laboratory results of water quality in well in addition to the position of sharp-interface. Accordingly the evaluation of coastal groundwater flow using sharp-interface model can produce reasonable results.

• Information Systems Review
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• v.10 no.3
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• pp.155-183
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• 2008

Current trend of audit is to check the physical aspects of developed information system, such as checking the budget constraints, time constraints or functional fluency etc. However, ultimate goal of information system is to help the organization to achieve the competency over their competitors. Also, there are three different interest groups in system auditing, like audit requesting group, audited group and audit group, who may have different points of interests in auditing. Current auditing process, however, ignores this point, and so does not check the differences between three groups. This study tries to develop new auditing method to cure these two problems. Contributions of this study may be summarized as follows. First, Introduce the new indexes that can check the possibility that the information system may contribute the competency of organization. Also check the feasibility of indexes through Fuzzy AHP. Second, Divide the audit related person into three groups, and their different needs toward the information system was analyzed. Third, Analyze and compare the main interests of three groups, and weights of each groups to each indexes were calculated. Fourth, Fuzzy theory was applied to quantify the qualitative answers, which may minimize the ambiguity of questionnaire replies.

• Journal of KIISE:Information Networking
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• v.32 no.5
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• pp.615-624
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• 2005

In Mobile IP, several types of messages - binding update, binding request and binding acknowledgement - are used to support user mobility. It is necessary to exchange those messages frequently for seamless mobility but it incurs both the increase of network overhead and poor usage of mobile node battery power Thus, we need a mechanism that the server detects users location and also copes with the problems effectively, which is our main concern in this paper Each user records all moving logs locally and periodically makes out profile based on them in HMIPv6. By using profile, estimated resident time can be computed whenever he enters an area and the time is set up as the binding update message lifetime. Of course, the more correct lifetime nay be obtained IP arrival time as well as average resident time Is considered in profile. Through extensive experiments, we measure the bandwidth usage for binding update messages by comparing the proposed schemes with that in HMIPv6. From the results, Gain gets over $80\%$ when mobile node stays more than 13 minutes in a subnet. Namely, we come to know that our schemes improve network usage and energy usage in mobile node by decreasing the number of messages while they also manage users locations like that in HMIPv6.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.1
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• pp.174-182
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• 2014

To monitor the wind-induced responses of buildings, conventional real-time kinematic (RTK) methods based on two global positioning system (GPS) receivers (e.g., a reference and a rover) are widely applied. However, these methods can encounter problems such as difficulty in securing and maintaining a space for a reference station. With the recently developed virtual reference station (VRS)-RTK approach, the position of a structure can be measured using only a rover receiver. In this study, to evaluate the applicability of VRS-RTK methods in monitoring the lateral structural responses of frame structures, we performed free vibration tests on a one-story frame model (the first natural frequency of 1 Hz) and a three-story frame model (the first natural frequency of 0.85 Hz). To assess the reliability of the displacement and acceleration responses measured by the GPS, we performed a concurrent measurement using laser displacement sensors and an accelerometer. The accelerometer results were consistent with the GPS measurements in terms of the time history and frequency content. Furthermore, to derive an appropriate sampling rate for the continuous monitoring of buildings, the errors in the displacement responses were evaluated at different GPS sampling rates (5, 10, 20 Hz). The results indicate that as the sampling rate increased, the errors in the displacement responses decreased. In addition, in the three-story model, all modal components (first, second, and third modes) could be recorded at a sampling rate of 20 Hz.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.6A
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• pp.63-73
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• 2008

RFID(Radio Frequency IDentification) system is an automated identification system that basically consists of tags and readers and Back-End-Databases. Tags and Readers communicate with each other by RF signal. As a reader can identify many tags in contactless manner using RF signal, RFID system is expected to do a new technology to replace a bar-code system in supply-chain management and payment system and access control and medical record and so on. However, RFID system creates new threats to the security of systems and privacy of individuals, Because tags and readers communicate with each other in insecure channel using RF signal. So many people are trying to study various manners to solve these problems against attacks, But they are difficult to apply to RFID system based on EPCglobal UHF Class-1 Generation-2 tags. Recently, Chien and Chen proposed a mutual Authentication protocol for RFID conforming to EPCglobal UHF Class-1 Generation-2 tags. we discover vulnerabilities of security and inefficiency about their protocol. Therefore, We analyze vulnerabilities of their protocol and propose an efficient mutual authentication protocol that improves security and efficiency.