• Journal of the Korea Institute of Information Security & Cryptology
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• v.9 no.1
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• pp.47-56
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• 1999

RBAC(Role Based Access Control) is an access control method based on the user's roles and it provides more flexibility and applicability on the various computer and network security fields than DAC(Discretionary Access Control) or MAC(Mandatory Access Control). In this paper, we newly propose ERBAC$_{0}$(Extended RBAC$_{0}$) model by considering subject's and object's roles additionally to REAC$_{0}$ model which is firstly proposed by Ravi S. Sandhu as a base model. The proposed ERBAC$_{0}$ model provides finer grained access control on the base of subject and object level than RBAC$_{0}$ model.

• Journal of the Korean association of regional geographers
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• v.16 no.2
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• pp.137-153
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• 2010

The issue of spatial equity in public healthcare services is an important issue in rural areas with lower healthcare resources. This study investigates spatial accessibility to public healthcare services by public transport, focusing on bus travel in Yeoju-gun, Gyeonggi-do. We comprehensively analyzed the spatial patterns of accessibility using the measures based on spatial interaction, and compared them with the accessibility patterns by car travel. As a result of analysis, the spatial disparity between the central part of Yeoju-gun (lower accessibility) and its peripheries (higher accessibility) was identified. More specifically, the area and population of lower accessibility areas are greater than those of higher accessibility areas, and the difference in the accessibility values between higher and lower accessible areas is considerably large. Moreover, the accessibility patterns appears somewhat different according to two different travel modes. In particular, about 20% of the entire area presented the opposite patterns between two travel modes. Interestingly, less populated peripheral areas are more included in higher accessible areas by car.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.5
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• pp.183-196
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• 2022

Public transportation accessibility has been evaluated through minimum level of service for public transportation. However it is evaluated based operators rather than users. This study analyzed the users' accessibility(first-mile, last-mile) to public transportation using altteul transport card data. As a result of user's accessibility of public transportation, rural areas was lower than that in the urban areas. This study calssified type 1 and 2 based average approach time, and average approach time of Type 1 and 2 were more than average approach time of total area. We propsed an efficient introduction of autonomous public transportation on-demand service using delphi survey. As a result of delphi survey, experts agreed on 9 items regarding function, service item, route operation, approach distance, route mileage, punctuality.

• Environmental and Resource Economics Review
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• v.10 no.1
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• pp.25-44
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• 2001

본 논문의 목적은 양분선택질문형 비시장가치평가법을 통한 편익추정에 사용되는 제 함수의 적합성 여부를 검증하기 위해 사용될 수 있는 방법론들을 비교 검토하는 것이다. 여가수렵의 환경적 요인의 변화에 따른 편익추정에 사용된 함수의 적합성을 판단하기 위해 변이계수접근법, 함수설정 오류 테스트, 그리고 비모수접근법 등이 각 함수에 적용되었다. 결과에 따르면, 편익추정에 이용된 세 가지 로짓함수(선형, 로그, 쉐어모형) 모두 적합한 것으로 판정되었다. 주어진 함수형태에 적용된 세 방법론간에 밀접한 일치성을 보였으며 경우에 따라서는 상호보완적이라는 함축성을 보이기도 하였다 이와 같은 결론은 로짓함수로부터 추정된 값들에 Krinsky-Robb 시뮬레이션을 이용하여 구축한 신뢰구간의 함수간 비교를 통해서도 확인되었다. 주어진 환경 시나리오에 대해 각 함수로부터 도출된 평균 추정치의 신뢰구간이 모두 충분히 중복되었기 때문에 편익추정과 관련하여 함수형태간에 유의적 차이가 없음이 입증된 것이다.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.1260-1263
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• 2011

모바일 애드혹 네트워크에서는 모바일 노드의 이동성과 네트워크의 단절성으로 인해 데이터 접근성이 감소하게 된다. 이런 문제점을 해결하기 위해 데이터 복제본을 활용하여 데이터 접근성 향상을 위한 많이 기법들이 연구되었다. 하지만, 제안된 기법들은 노드가 가지는 이기적인 특징을 고려하지 않은 기법이기 때문에 실제 모바일 애드혹 네트워크에서 이기적 행동을 하는 노드가 존재할 경우에는 데이터 접근성이 상당히 낮아진다. 최근에 이기적 노드가 존재하는 모바일 애드혹 네트워크에서의 데이터 복제본 할당을 위한 기법이 제안되엇다. 하지만 이 기법은 이기적 노드를 데이터 복제본 할당 기법에서 완전히 배제를 시키기 때문에 이기적 노드를 활용할 수 없다. 그 결과, 데이터 접근성에 안좋은 영향을 미치게 된다. 본 논문은 모바일 애드혹 네트워크에서 이기적 노드가 존재할 경우에 이기적 노드를 활용하기 위해 모든 노드를 이기적 정도와 거리에 따라 측정을 하고, 측정값을 기준으로 노드들을 레벨화 할 수 있는 기법을 제안한다. 실험 결과는 제안하는 기법이 기존 기법에 비해 이기적 노드들이 모바일 애드혹 네트워크 상에 존재하는 환경에서 데이터 접근성이 향상됨을 보여준다.

• Journal of Nutrition and Health
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• v.47 no.6
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• pp.475-483
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• 2014

Purpose: The purpose of this study was to measure accessibility and to examine distribution of restaurants in the local community. Methods: The target area of this study was two urban areas and a rural area in a city. We collected location information on all restaurants in target areas and classified all restaurants according to Korean food restaurants and Non-Korean food restaurants. We measured restaurant density per 100 m from the residences of the study population and calculated the distance of the nearest restaurant from the residences of the subjects using the Geographic Information System (GIS) analysis method. We compared the accessibility and distribution of restaurants in urban areas with that of the rural area, and compared the accessibility and distribution of Korean restaurants with that of Non-Korean restaurants. Results: Restaurants in urban areas were more dense than those in the rural area, and, in urban areas, restaurants were intensively distributed around the subjects' residence. Also, there were more Non-Korean food restaurants than Korean food restaurants in urban areas, and it was opposite in the rural area. Conclusion: It is important that we understood the current state of the restaurant environment in the local community using GIS analysis for the first time in the field of food environment. Further research is necessary on the association of restaurant environments and the dietary life of the population.

• Journal of Digital Convergence
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• v.11 no.5
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• pp.405-410
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• 2013

Due to the enforcement of a law about disability nondiscrimination and rights protection in 2008, the web accessibility has become an obligation. According to a survey targeting public sectors such as central administrative organization, local autonomous entity and etc., the level of compliance with web accessibility appeared to be improved every year. However, such legal mechanism focuses on the improvement of convenience for disabled people only and does not meet the concept of universal design that aims to satisfy every user. Therefore, this study verifies the status of web accessibility on 17 homepages of metropolitan and provincial offices of education. The status survey was carried out with 3 steps: 1) Verification through automated verification tool by National Information Society Agency, 2) Verification through Web Content Accessibility Guidelines(UD-WCAG) that adopts the concept of universal design, 3) Verification by using screen reader. Compared to the verification through automated verification tool, the overall compliance rate verified through UD-WCAG was reported lower.

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.01a
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• pp.5-7
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• 2016

본 논문에서는 블록 생성 번호를 활용한 동적 마모도 평준화 기법을 제안한다. 지금까지 제안된 동적 마모도 평준화 기법들은 콜드 블록을 판별하기 위해 경과 시간을 사용하고 있다. 하지만 저장장치의 데이터 접근은 일정한 시간 간격으로 이루어지는 것이 아니기 때문에 이와 같은 경과 시간을 사용하는 방식은 데이터에 대한 블록 접근 정보가 왜곡될 수 있는 단점이 있다. 이러한 단점을 해결하기 위해, 본 논문에서 제안하는 기법은 블록을 할당할 때 블록 순차 번호를 테이블에 저장하고 이를 이용하여 블록의 접근 빈도를 판별한다. 실험에서 제한하는 기법은 기존의 CB, CAT 기법과 비교하여 최대 11% 수명이 향상됨을 확인하였다.

• Journal of Digital Convergence
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• v.15 no.6
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• pp.219-227
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• 2017

Network access control should be able to effectively block security threats to the IT infrastructure, such as unauthorized access of unauthorized users and terminals, and illegal access of employees to internal servers. From this perspective, it is necessary to build metrics based on relevant standards to ensure that security is being met. Therefore, it is necessary to organize the method for security evaluation of NAC according to the related standards. Therefore, this study builds a model that combines the security evaluation part of ISO / IEC 15408 (CC: Common Criteria) and ISO 25000 series to develop security metric of network access control system. For this purpose, we analyzed the quality requirements of the network access control system and developed the convergence evaluation metric for security of the two international standards. It can be applied to standardization of evaluation method for network access control system in the future by constructing evaluation model of security quality level of network access control system.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.1 no.1
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• pp.37-43
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• 2007

Internet is essential to live nowadays, but persons with disabilities are hard to use internet because people who develops and operate web sites don't think and comply the web accessibility standard. In order to solve this problem, Korea governments implement a lot of policies such as. making web accessibility standard, operating web accessibility education program, etc.. The purpose of this paper is examined the web accessibility compliance of major web sites such as portal, news, banking, education in Korea. In order to investigate the web accessibility compliance status of major web sites's in Korea, 15 web sites were chosen. This study was used the 4 major checkpoints that must be the crucial among 14 checkpoints in Internet Web Contents Accessibility Guidelines which was amended by Ministry of the Information and Communication in 2005. The results of this study showed that 15 major web sites in Korea didn't meet the 4 major checkpoints.