• 한국인터넷방송통신학회논문지
• /
• 제8권5호
• /
• pp.211-219
• /
• 2008

본 논문은 기존의 접근제어 모델을 확장하여 상황인식 기반 접근제어 모델을 제안하였다. 본 논문에서 xoRBAC와 CAAC와 같은 상황인식기반 보안모델에 대한 최근연구들을 조사하였다. 정확한 정책평가를 위해 기존의 CAAC 보안모델에 상황브로커와 파인더 컴포넌트를 추가하였다. 이 보안모델에 의해 더욱 명확한 정책결정을 위해 상황정보 및 상황결정정보를 보다 용이하게 수집할 수 있다. 또한, 접근된 자원에서 또 한번의 사용자 이벤트를 판단하여, 접근할 수 있는 모든 가능한 자원들을 제어하였다. 본 논문에서 제안된 보안모델은 역할에 따른 특정정책과 제약조정을 통해 다양한 보안등급 및 접근권한방식을 동적으로 제공할 수 있다.

• 한국임상약학회지
• /
• 제28권1호
• /
• pp.40-50
• /
• 2018

Objective: This study presented the analysis period, the complexity of combined therapy and comparator choice as the key limitations in the economic evaluation of new drugs, and discussed programs for coping with these limitations. Methods: This study evaluated the post-evaluation, risk-sharing agreement, extra funding program, and flexible incremental cost-effectiveness ratio (ICER) threshold as actions or programs that would increase accessibility to costly new drugs. The study also presented the cases of other countries. The application of the post-evaluation was considered to deal with high uncertainty regarding new drugs. Results: The risk-sharing agreement was introduced in European countries as well as South Korea and has been responsible for the shift from using the financial schemes to outcome-based schemes. The drug funding program has had troubled in securing stable extra funds. The application of higher ICER in the economic evaluation of expensive and innovative oncology drugs was criticized because of the inequity between oncology patients and patients with other diseases. Conclusion: Therefore, introducing and applying actions that would increase the accessibility to costly new drugs in South Korea have been deemed necessary after careful reviews and discussions with various stakeholders (insurer, policy makers, pharmaceutical companies and patients).

• Journal of Communications and Networks
• /
• 제15권1호
• /
• pp.25-30
• /
• 2013

Uplink multicarrier code-division multiple-access (MC-CDMA) with equal gain combining (EGC) over Nakagami fading channels is considered. An improved expression which is a feasible alternative for the bit error rate (BER) performance evaluation of MC-CDMA signals is proposed. Simulated annealing algorithm is employed to obtain the optimum value of the coefficients belonging to the proposed expression. Numerical examples show that the performance curves computed by the improved expression are in good agreement with the results obtained by the exact expression. Thus, the proposed expression can improve the accuracy of BER performance evaluation that has been realized by the approximate expression.

• Journal of Information Science Theory and Practice
• /
• 제12권1호
• /
• pp.87-101
• /
• 2024

As the academic publishing environment evolves rapidly and the open science paradigm emerges, the demand for efficient and transparent peer review is growing. This study outlines efforts to actively introduce advanced concepts in scholarly communication into the submission and review system. AccessON Peer Review Management System Plus (ACOMS+), developed and operated by the Korea Institute of Science and Technology Information, is an online submission and peer review system that aims for open science. This study provides an overview of ACOMS+ and presents its four main features: open peer review, open access publishing and self-archiving, online quantitative/qualitative evaluation, and peer reviewer invitation. The directions for further developing ACOMS+ to fully support open science are also discussed. ACOMS+ is the first system in Korea to introduce the open peer review process and is distinguished as a system that supports open access publishing and digital transformation of academic journals. Furthermore, ACOMS+ is expected to contribute to the advancement of the academic publishing environment through the increasing shift toward open access publishing, transparent peer review, and open science.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제16권5호
• /
• pp.1634-1652
• /
• 2022

Due to the increasing need for data sharing in the age of big data, how to achieve data access control and implement user permission revocation in the blockchain environment becomes an urgent problem. To solve the above problems, we propose a novel blockchain-based data sharing scheme (BDSS) with fine-grained access control and permission revocation in this paper, which regards the medical environment as the application scenario. In this scheme, we separate the public part and private part of the electronic medical record (EMR). Then, we use symmetric searchable encryption (SSE) technology to encrypt these two parts separately, and use attribute-based encryption (ABE) technology to encrypt symmetric keys which used in SSE technology separately. This guarantees better fine-grained access control and makes patients to share data at ease. In addition, we design a mechanism for EMR permission grant and revocation so that hospital can verify attribute set to determine whether to grant and revoke access permission through blockchain, so it is no longer necessary for ciphertext re-encryption and key update. Finally, security analysis, security proof and performance evaluation demonstrate that the proposed scheme is safe and effective in practical applications.

• 한국콘텐츠학회논문지
• /
• 제7권11호
• /
• pp.43-51
• /
• 2007

접근 제어 기법은 아주 작은 단위의 보호 수준을 지원할 만큼 충분히 유연해야 한다. 또한 접근 제어 정책은 문서 타입과 관련하여 명세될 가능성이 매우 높으므로 문서가 기존의 접근 제어 정책에 의해 다루어지지 않는 상황을 적절하게 관리해야 한다. 기존의 접근 제어는 HTML의 근본적인 한계 때문에 정보 구조와 의미론을 충분히 고려하지 못하였다. 또한 XML 문서에 대한 접근 제어는 읽기 실행만을 제공하며, 복잡한 권한의 평가 과정 때문에 시스템 성능이 저하되는 문제점이 존재한다. 이러한 문제점을 해결하기 위해 본 논문에서는 미세 접근 제어가 가능한 XML 접근 제어 관리 시스템을 설계한다. 접근 제어 시스템을 개발함에 있어 어떤 권한부여를 명세하고 어떤 접근 제어를 실행해야 하는가와 관련하여 XML 문서 권한부여 주체와 객체 정책에 관하여 기술한다.

• Journal of Communications and Networks
• /
• 제14권5호
• /
• pp.524-532
• /
• 2012

In this paper, we present the performance evaluation of the reliable cooperative media access control (RCO-MAC) protocol, which has been proposed in [1] by us in order to enhance system throughput in bad wireless channel environments. The performance of this protocol is evaluated with computer simulation as well as mathematical analysis in this paper. The system throughput, two types of average delays, average channel access delay, and average system delay, which includes the queuing delay in the buffer, are used as performance metrics. In addition, two different traffic models are used for performance evaluation: The saturated traffic model for computing system throughput and average channel access delay, and the exponential data generation model for calculating average system delay. The numerical results show that the RCO-MAC protocol proposed by us provides over 20% more system throughput than the relay distributed coordination function (rDCF) scheme. The numerical results show that the RCO-MAC protocol provides a slightly higher average channel access delay over a greater number of source nodes than the rDCF. This is because a greater number of source nodes provide more opportunities for cooperative request to send (CRTS) frame collisions and because the value of the related retransmission timer is greater in the RCO-MAC protocol than in the rDCF protocol. The numerical results also confirm that the RCO-MAC protocol provides better average system delay over the whole gamut of the number of source nodes than the rDCF protocol.

• 정보보호학회논문지
• /
• 제17권2호
• /
• pp.61-72
• /
• 2007

With the increasing growth of Internet and wireless IP networks, Multimedia systems need to be envisaged as information resources where users can access anywhere and anytime. However, efficient services in these multimedia systems are open and challenging research problem due to user mobility, limited resources in wireless devices and expensive radio bandwidth. To implement multimedia services over heterogeneous network, the IP header compression scheme can be used for saving bandwidth. In this paper, we present an efficient solution for header compression, which is modified form of ECRTP. It shows an architectural framework adopting modified ECRTP when IP tunneling network using GRE over IPSec is implemented. We have conducted simulations in order to analyze the effects of different header compression techniques while delivering real-time services to the wireless access network through secured IP Network. The impacts on performance have been investigated through a series of experiments.

• 한국통신학회논문지
• /
• 제30권5B호
• /
• pp.310-316
• /
• 2005

본 논문에서는 HIPERLAN/2(HIgh PErformance Radio Local Area Network type 2)의 랜덤 액세스 과정에서 채널 환경을 고려함으로 처리 성능을 높이고 전송 지연을 개선한 적응적 랜덤 액세스 기법(ARAH : Adaptive Random Access algorithm for HIPERLAN/2)을 제안하고 기존 방식에 비해 성능이 향상됨을 검증하였다. 본 논문에서는 HIPERLAN/2에서 채널의 상태에 따라 OFDM(Orthogonal frequency Division Multiplexing) modulation scheme을 기반으로 제공하는 7가지 PHY(Physical) mode를 Good 그룹과 Bad 그룹으로 양분하고, Good 그룹에 속하는 단말들에게 랜덤 액세스 과정에서 우선순위를 갖게 함으로써 처리율을 높이도록 하는 방식을 취하고 있다. ARAH 방식에 대하여 성능을 평가한 결과, 처리율과 전송 지연에 대해 성능이 향상됨을 보이고 있다.

• 한국콘텐츠학회:학술대회논문집
• /
• 한국콘텐츠학회 2004년도 추계 종합학술대회 논문집
• /
• pp.291-295
• /
• 2004

XML 문서가 웹 문서의 표준으로 자리 잡음에 따라 많은 정보들이 XML 문서 형식으로 표현되면서 XML 문서의 보안에 관한 요구도 커지고 있다. 현재까지의 XML 보안에 관한 연구는 암호화와 전자 서명 같은 통신상의 보안에 관한 연구가 중심이 되었으나 XML 문서가 방대해지고 복잡해짐에 따라 XML 문서에 대한 통신상의 보안 뿐 아니라 관리적인 보안이 필요하게 되었다. 하지만 XML 문서의 암호화는 단순한 통신상의 보안만을 제공할 뿐 관리적 보안 요소인 다양한 사용자와 다양한 접근 권한 정책을 반영하지 못하고 있다. 본 논문에서는 XML 문서의 보안을 위해 주체별 권한 정책을 반영한 접근 제어를 보장하는 주체 기반 XML 문서의 암호화 기법을 제안한다. 접근 제어를 보장하는 암호화를 수행함으로써 다양한 사용자의 다양한 권한 정책을 반영할 수 있다. 또한 제안하는 암호화 기법은 전처리 과정을 이용하여 기존의 접근 제어 기법의 복잡한 접근 평가 비용을 줄일 수 있다.