• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권5호
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• pp.2768-2780
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• 2019

Ciphertext-policy attribute-based encryption (CP-ABE) is one of the practical technologies to share data over cloud since it can protect data confidentiality and support fine-grained access control on the encrypted data. However, most of the previous schemes only focus on data confidentiality without considering data receiver privacy preserving. Recently, Li et al.(in TIIS, 10(7), 2016.7) proposed a CP-ABE with hidden access policy and testing, where they declare their scheme achieves privacy preserving for the encryptor and decryptor, and also has high decryption efficiency. Unfortunately, in this paper, we show that their scheme fails to achieve hidden access policy at first. It means that any adversary can obtain access policy information by a simple decisional Diffie-Hellman test (DDH-test) attack. Then we give a method to overcome this shortcoming. Security and performance analyses show that the proposed scheme not only achieves the privacy protection for users, but also has higher efficiency than the original one.

• 한국정보통신학회논문지
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• 제24권1호
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• pp.145-148
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• 2020

Wearable computing is growing rapidly as research on body area communication network using wireless sensor network technology is actively conducted. In particular, there is an increasing interest in smart clothing measuring unrestrained and insensitive bio signals, and research is being actively conducted. However, research on smart clothing is mainly based on 1: 1 wireless communication. In this paper, we propose a multi-access monitoring system that can measure bio-signals by multiple users wearing smart clothing. The proposed system consists of wireless access device, multiple access control server and monitoring system. It also provides a service that allows multiple users to monitor and measure bio signals at the same time.

• 한국통신학회논문지
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• 제28권1A호
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• pp.17-24
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• 2003

Access Network은 대부분의 정보통신망에서 가장 중요한 요소라 할 수 있다. 또한 최종 이용자에서 직접 연결되는 부문으로 가장 많은 투자 재원이 요구되며, 최근에는 광대역의 매우 다양한 접속 기술이 개발 보급되고 있는 상황이다. 가입자의 이동성에 따른, 그리고 무선 전파 자원과 유선 교환 및 전송망을 이용한다는 복합적 특성으로 인하여 기존 유선의 가입자 망과는 다르게 이동망의 Access Network 내지는 가입자 접속부문에 대한 명확한 정의나 상세한 기능 및 범위가 정립되지 못하고 있는 상황이다 이에 본 논문은 ITU-T의 일반적인 Access Network의 기능적 모델을 참조하여 IS 95 A/B 및 cdma2000-1X 이동통신기술 표준의 음성 서비스를 위한 CDMA 기지국 시스템, 기지국 제어 시스템, 이동교환시스템 등의 하위시스템의 특성과 기능을 고찰하여 보다 체계적이고, 기능적 관점에서의 가입자 접속부문에 대한 대안적 정의를 제시한다.

• 한국문헌정보학회지
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• 제55권4호
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• pp.45-65
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• 2021

본 연구는 국내 연구자의 학술지 선택 특히 오픈액세스 학술지 선택의 기준과 오픈액세스 학술지 투고 경험을 조사함으로써 오픈액세스 인식 수준을 평가하고자 하였다. 대표적인 오픈액세스 메가 학술지인 PLOS ONE에 투고 경험이 있는 국내 교신 저자를 대상으로 온라인 설문을 진행하였으며, 총 238명이 응답하였고 202개의 유효 설문을 대상으로 분석을 수행하였다. 데이터의 해석을 위해 유사한 조사를 수행한 국제적인 연구 결과와 비교를 하였다. 오픈액세스 출판 경험이 있는 국내 연구자에게 학술지의 영향력 지수는 학술지 선택에 있어 가장 중요한 고려 사항이다. 또한 일반적인 학술지 선택의 기준과 오픈액세스 학술지 선택의 기준은 상당한 차이가 있는 것으로 나타났다. 국내 연구자들의 오픈액세스 출판 경험에 대한 만족도는 비교 연구의 결과에 비해 전반적으로 낮은 수준이다. 이는 국내 연구자들의 오픈액세스에 대한 기대 수준이 낮은데서 기인한 것으로 향후 정책과 교육을 통한 개선이 필요한 부분이다.

• Journal of Information Science Theory and Practice
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• 제1권3호
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• pp.47-59
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• 2013

The present study aims to assess the growth of open access journals at a global level. The concept of Open Access (OA) publishing is being well received among academic circles and as a result we can see more and more scholarly content is being made these days available in open access format. The present study is simply an attempt to assess the trend and growth of open access journals during the last decade, viz. for the period 2003-2012, for which data has been retrieved from the Directory of Open Access Journals (DOAJ), which as of date hosts more than 9700 journals from 120 countries across the world covering major languages of the world. But keeping in view the period of our study the data has been retrieved as per our applicability, which as a result confines our study to 8453 journals only. The directory covers 18 main subject areas having 76 sub-disciplines, each having on average 118.53 journals. During the entire decade the number of countries which entered into OA publishing rose from 49 to 120 with a growth of 144%, and if this growth rate continues to be the same for the next five years, viz. by 2018, the world will turn into 100% open access. At the continental level Europe leads the tally by publishing a maximum of 3140 OA journals contributed by 43 countries across Europe, which again is the highest number from any continent.

• 경영과학
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• 제24권2호
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• pp.127-142
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• 2007

This study deals with the optimal design of mobile access network connecting base stations(BSs) and mobile switching centers(MSCs). Generally mobile operators constitute their access networks by leasing communication lines. Using the characteristic of leased line rate based on administration region, we build an optimization model for mobile access network design which has much smaller number of variables than the existing researches. And we develop a GUI based optimization tool integrating the well-known softwares such as MS EXCEL. MS VisualBasic, MS PowerPoint and Ip_solve, a freeware optimization software. Employing the current access network configuration of a Korean mobile carrier, this study using the optimization tool obtain an optimal solution for both single MSC access network and nation-wide access network. Each optimal access network achieves 7.45% and 9.49% save of lease rate, respectively. Considering the monthly charge and total amount of lease line rate, our optimization tool provides big amount of save in network operation cost. Besides the graphical representation of access networks makes the operator easily understand and compare current and optimal access networks.

• 융합보안논문지
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• 제2권2호
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• pp.49-58
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• 2002

역할기반 접근통제는 추상적 기본 개념의 임의적 접근통제나 강제적 접근통제에 비하여 응용 개념의 역할에 기반한 접근통제 모델이다. 모델은 BLP 모델에서 출발한 커널 단위의 액세스 제어의 제한적 기능과 달리 다양한 컴퓨터 네트워크 보안분야에 있어서 유연성과 적용성을 제공한다. 본 논문에서는 기존의 역할기반 접근통제 기본 모델인 $RBAC_0$ 모델에 주체 및 객체의 역할을 추가로 고려한 역할 계층을 포함하는 확장된 역할기반 접근통제 ($ERBAC_0$ : Exteded $RBAC_0$ 모델을 제안하였다. 제안된 $ERBAC_0$ 모델은 기존의 $RBAC_0$ 모델에 비하여 주체 및 객체 수준에서의 역할을 계층적으로 정교하게 할당하고, 할당된 역할에 기반하여 접근통제 서비스를 보다 유연하게 제공할 수 있다.

• 한국임상약학회지
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• 제28권2호
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• pp.124-130
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• 2018

Objective: This study examined the Risk Sharing Agreement (RSA) on pharmaceutical pricing system in Korean national health insurance. Through RSA, the insurer was able to maintain the principles in the price listing process while managing the budget effectively and improving patient access to new drugs. Despite these positive effects, there are still issues raised by some stakeholders, such as lack of transparency in the listing process and doubts about its effectiveness. Therefore, we investigated the impacts of RSA on national health insurance financing and patient access to analyze the effects of RSA. Methods: The impact of RSA was investigated by analyzing the health insurance claims data for 2014~2016. The degree of improvement in patient access was determined by the decreased amount of patients' payment. Results: Results showed that the financial impact of RSA was not significant and patients' access to the new drug greatly improved. Conclusion: These results show that RSA is a good system for improving patient access to new drugs without additional expense on insurance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권11호
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• pp.3892-3912
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• 2021

The recent rapid growth of mobile network traffic places multi-access edge computing in an important position to reduce network load and improve network capacity and service quality. Contrasting with traditional mobile cloud computing, multi-access edge computing includes a base station cooperative cache layer and user cooperative cache layer. Selecting the most appropriate cache content according to actual needs and determining the most appropriate location to optimize the cache performance have emerged as serious issues in multi-access edge computing that must be solved urgently. For this reason, a cache placement algorithm based on comprehensive utility in big data multi-access edge computing (CPBCU) is proposed in this work. Firstly, the cache value generated by cache placement is calculated using the cache capacity, data popularity, and node replacement rate. Secondly, the cache placement problem is then modeled according to the cache value, data object acquisition, and replacement cost. The cache placement model is then transformed into a combinatorial optimization problem and the cache objects are placed on the appropriate data nodes using tabu search algorithm. Finally, to verify the feasibility and effectiveness of the algorithm, a multi-access edge computing experimental environment is built. Experimental results show that CPBCU provides a significant improvement in cache service rate, data response time, and replacement number compared with other cache placement algorithms.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권1호
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• pp.145-164
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• 2023

Cloud computing offers a platform that is both adaptable and scalable, making it ideal for outsourcing data for sharing. Various organizations outsource their data on cloud storage servers for availing management and sharing services. When the organizations outsource the data, they lose direct control on the data. This raises the privacy and security concerns. Cryptographic encryption methods can secure the data from the intruders as well as cloud service providers. Data owners may also specify access control policies such that only the users, who satisfy the policies, can access the data. Attribute based access control techniques are more suitable for the cloud environment as they cover large number of users coming from various domains. Multi-authority attribute-based encryption (MA-ABE) technique is one of the propitious attribute based access control technique, which allows data owner to enforce access policies on encrypted data. The main aim of this paper is to comprehensively survey various state-of-the-art MA-ABE schemes to explore different features such as attribute and key management techniques, access policy structure and its expressiveness, revocation of access rights, policy updating techniques, privacy preservation techniques, fast decryption and computation outsourcing, proxy re-encryption etc. Moreover, the paper presents feature-wise comparison of all the pertinent schemes in the field. Finally, some research challenges and directions are summarized that need to be addressed in near future.