• Proceedings of the Korea Information Processing Society Conference
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• 2001.04a
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• pp.93-96
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• 2001

공간 데이터베이스에서는 공간 객체에 대해 객체마다 서로 다른 보안 등급을 설정함으로써 공간 객체에 대한 보안을 유지하고 있다. 다단계 보안을 사용하여 사용자의 보안 등급에 따라 공간 객체에 대한 접근을 제어할 경우 인접 객체와의 위상관계를 통해서 공간 정보뿐만 아니라 비공간 정보의 노출(information flow)이라는 문제가 발생하게 된다. 이에 대한 해결책으로 데이터베이스에 대한 부분집합만을 추출하여 사용자의 권한에 맞는 질의 결과를 제공하는 것이다. 즉 공간 뷰를 정의함으로써 사용자 등급에 맞는 결과 집합(result set)을 제공함으로써 보다 효율적인 연산을 수행할 수 있게 된다. 따라서 본 논문에서는 실세계의 지리 객체들에 대한 다양한 사용자 관점과 다단계 보안 등급을 가진 뷰를 지원하기 위해 관계형 데이터베이스의 뷰 개념을 확장한 공간 데이터베이스의 공간 뷰를 제안하고, 공간 연산 시 발생하는 정보 흐름 제어를 위한 방법을 제시한다.

• The Journal of the Convergence on Culture Technology
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• v.5 no.3
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• pp.305-310
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• 2019

This paper proposes the method of exactly identifying both viscous and friction damping from free vibration response to SDOF structure. Both displacement and acceleration free vibration responses to SDOF system, in which both viscous and friction damping are considered as its damping mechanism, are discussed to verify the proposed method. The relationship for identifying both viscous and friction damping is derived from two consecutive amplitudes of displacement or acceleration peak response. The proposed method is verified through the numerical simulation for an assumed SDOF system consisting of mass, both viscous and friction damping and spring components.

• Journal of Korea Multimedia Society
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• v.15 no.9
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• pp.1133-1148
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• 2012

This paper presents a hierarchical structuring method for the multidimensional type inheritance indices (MD-TIXs) that support the processing of XML queries in XML databases. MD-TIX uses a multidimensional index structure for efficiently supporting ancestor-descendant explorations that involve both nested element and type inheritance hierarchies. However, In the case of a long Xpath, the building and maintenance of MD-TIX are very difficult because of index entry construction problem. So, we propose a type inheritance index hierarchy method for solving this difficulty. We first construct base indices that support direct relationship explorations between adjacent two types on a given Xpath, and then, based on these base indices, we construct hierarchically the derived indices that support indirect relationship explorations between any two types of Xpath until constructing one target index for supporting the full Xpath. And we also present an algorithm that efficiently constructs a partial index hierarchy for supporting given a set of sub-pathes explorations.

• The korean journal of orthodontics
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• v.28 no.6 s.71
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• pp.981-989
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• 1998

Positions, angulation and mesiodistal dimension of lower incisors are important in esthetics, occlusion and post-treatment stability of tower arch. When lower incisor is congenitally missing, problems such as increased overjet and overbite, closing in of adjacent teeth and size/space discrepancies may occur. When creating treatment plans, incisor position and angulation, lip support, anteroposterior skeletal relationship canine-molar relationship, overjet overbite, remaining growth potential, crowding and anterior tooth ratio have to be considered. For an accurate analysis of incisal size discrepancy, diagnostic model set-up may be helpful. The two patients in this presentation both had two lower incisor missing, but the degree of crowding, skeletal relationship, lip support, molar relationship are different and therefore treatment plan was different as well. Long term follow-up may be necessary for stability and retention.

• Journal of Korean Society of Transportation
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• v.24 no.2 s.88
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• pp.127-137
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• 2006

This Paper Presents a novel incident detection method for using the speed-density difference between detectors. When a incident is happened the downstream traffic condition is mostly lower speed and higher density and the upstream is higher speed and lower density In respect of such characteristics, we can suggest a method for detecting an incident based on the speed-density information provided from detectors. The incident detection method is tested by using the accident data collected from the Cheonan-Nonsan Highway. The results show that suck an incident detection method can analyze the position of accident by comparing the speed-density difference between detectors. The work described in this paper is only at on early stage, in the sense that there are several areas to be further investigated in application of this method. such as setting a critical value for judging the incident. a level of accident wave, a varying Pattern between the incident locations and detectors, etc.

• Journal of the Korean association of regional geographers
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• v.10 no.4
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• pp.787-799
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• 2004

The industrial community in a metropolis has played an essential role to keep business in a large city. This paper aims to analyze the realities of trade network among enterprises at Buksungro Tools Commercial Cooperative in Daegu. The urban style industrial community is found at Buksungro in Daegu. There are more than one hundred small-sized enterprises. Major trades among enterprises are occurred within and/or by the area. The long-term trade networks within the Buksungro Tools Commercial Cooperative have played the key role to maintain the industrial community. The trade relationship has depended on business networks based on social capital rather than commercial mechanism. The trade networks have been established through credit transactions as well as handling troublesome orders. The trade networks help to transfer technology and to learn the tacit knowledge among firms. The long-term trade networks are more influenced by the social accessibility than spatial accessibility.

• Spatial Information Research
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• v.19 no.1
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• pp.93-105
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• 2011

In recent years, large and complex three-dimensional building has been constructed by the development of building technology and advanced IT skills, and people have lived there and spent a considerable time so far. Accordingly. in this sophisticatcd three-dimensional space, emergencies services or convenient information services have been in demand. In order to provide these services efficiently, understanding of topological relationships among the complex space should be supported naturally. Not on1y each method of understanding the topological relationships but also its efficiency can be different depending on different topological data models. B-rep based data model is the most widely used for storaging and representing of topological relationships. And from early 2000s, many researches on a network based topological data model have been conducted. The purpose of this study is to verify the efficiency of performance on spatial queries. As a result, Network-based topological data model is more efficient than B-rep based data model for determining the spatial relationship.

• Journal of the Korean association of regional geographers
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• v.15 no.5
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• pp.590-603
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• 2009

This report studies what connections was between Ethnic education movement in Bukkando and natural and human knowledge environment as a way to complement total absence of studying Anti-Japanese Movement at the Geographic levels. The summary is as following: At first, the Korean villages, where almost all spread the national schools, so there was a very close relationship. Both from a Longjing as the central plain area to the proliferation of surrounding areas. Second, schools that was adjacent to trunk road were given a great deal of weight on the connection with traffic. After that, however, it decreased gradually. Third, the national schools suffered the dual intervention from China and Japan, experienced a difficult development process. the schools which built by Japan were spreaded areas where concentrate the schools which built by Japan were spreaded areas where concentrated many national schools, both have a close relationship. before 3.13 movement, the distribution of schools that established by the Chinese mainly spreaded the areas concentrated national schools. But, after the 3.13 movement, it appeared a tendency to spread to the Korean people area where relatively dwelled a few people.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.2
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• pp.13-25
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• 2011

Biometric-based authentication can provide strong security guarantee about the identity of users. However, security of biometric data is particularly important as the compromise of the data will be permanent. The fuzzy fingerprint vault system is one of the most popular solutions for protecting the fingerprint template stored in the database. Recently, however, this system is very susceptible to a correlation attack that finds the real minutiae using multiple fingerprint vaults enrolled for different applications. To solve this problem, we propose a robust fuzzy fingerprint vault system against the correlation attack. In this paper, we add chaff minutiae based on the relative information of minutiae such as direction, coordinate instead of adding randomly. Also, our proposed approach allow to add multiple chaff minutiae within tolerance box for enhanced security level. Experimental results show that the proposed approach can protect the correlation attack and achieve enhanced verification accuracy.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2C
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• pp.95-107
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• 2010

To calculate the end bearing capacity of a drilled Shaft socketed into the rockmass, the unconfined compression strength could be used. But it is difficult to find the unconfined compression strength because it is impossible to get undisturbed samples in weathered soils and rocks. So, to calculate the end bearing capacity, the existing bearing formula could not be used. In this study, for five zones (near pile tip, tip~lower 1D, tip~lower 2D, upper 1D~lower 1D, upper 1D~lower 2D), the relationships between the characteristic values of in-situ tests(SPT, DCPT PMT, BST) and the end bearing capacity of drilled shafts were analysed. As a result, DCPT results were represented the best credibility. Also, a design chart of end bearing capacity using DCPT was suggested.