• Architectural research
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• 제22권3호
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• pp.85-95
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• 2020

While there has been a substantial amount of studies on public rental housing of Korea, most have focused on housing policy changes, international comparisons, and current characteristics and future prospects. This article aims to examine the evolving roles of the national and local governments, and the private sector in provision of Korea's public rental housing. The findings suggest that one, although the wave of neoliberalism and financial crisis have prompted the national government to reduce its role and to encourage engagement of other actors by utilizing incentivizing tools, it has continued to assume a central position in formulating and implementing housing supply plans. Two, local governments have played a marginal role throughout the history of public rental housing supply, although they have expanded their participation through redevelopment projects and utilization of existing housings. Three, private sector actors have expanded their role to delivering public benefits of making housing available for a wider range of populace leveraging various incentives that make projects financially more feasible. The study poses a question on how responsibilities and risks can appropriately be allocated among three key actors to achieve housing welfare going forward.

• 경영정보학연구
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• 제9권1호
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• pp.311-341
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• 2007

본 연구는 공기업형 조직인 우정사업본부에 대한 BSC(Balanced Scorecard)시스템 구축사례를 제시한다. 일반적으로 공공부문과 민간부문의 BSC 모델은 서로 상이한 전략목표로 인해 각각 다른 형태로 구축된다. 우정사업본부는 현재 정부기업으로서 공공부문의 성격을 많이 내포하고 있으면서, 또한 민간부문과 유사한 BSC 특성을 가지고 있다. 즉 민간기업이 아닌 공기업으로서의 조직의 형태를 띠고 있다. 현재 공기업을 포함하는 많은 정부 산하기관들이 BSC를 도입했거나, 도입하려고 하지만, BSC에 대한 이해부족으로 말미암아 예상보다 BSC 시스템을 성공적으로 구축하는데 많은 어려움을 겪고 있다. 이에 본 연구에서는 우정사업본부의 BSC 사례분석을 통해 공기업의 BSC 시스템 구축의 주요 성공요인과 문제점을 분석하고, 향후 공기업의 BSC 시스템을 위한 발전방향을 제시하였다.

• 한국인터넷방송통신학회논문지
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• 제19권5호
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• pp.33-38
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• 2019

본 논문에서는 유럽연합의 개인정보 보호 규제인 GDPR을 준수하는 새로운 블록체인 모델을 제안한다. 제안하는 모델은 블록체인 거래에 포함된 개인정보에 대한 접근을 권한에 따라 차등적으로 통제하여 불법적인 개인정보 처리를 방지하는 한편, 보유기간이 경과된 또는 임의의 합법적 삭제 요청을 받은 개인정보에 대하여 접근을 영구히 차단하여 잊혀질 권리을 보장한다. 제안 모델의 핵심 메카니즘은, 개인정보를 접근정책에 따라 속성기반암호화한 후 이를 조회자의 속성(소속, 직무 등)을 반영한 일회용 토큰으로 복호화하는 것이다. 주목할 점은, 기존 기술이 제3의 신뢰기관을 필요로 하였다면 제안 모델은 신뢰기관 없이 블록체인에서 선발된 다수의 노드들로 하여금 그 기능을 대체하도록 하여 신뢰기관 리스크를 개선하였고, 아울러 속성 갱신에 따른 키 관리 효율성을 극대화하고자 복호키를 일회용 토큰으로 생성하였다는 점이다. 우리는 제안 모델을 허가형 블록체인인 패브릭의 체인코드를 이용하여 시뮬레이션 하고, 보안성을 분석함으로써 타당성을 입증하였다.

• 유통과학연구
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• 제13권2호
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• pp.5-13
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• 2015

Purpose - In recent years, concerns over privatization have been growing in some public sectors. Privatization in Britain offers lessons for those who have intended to privatize their industry, and in particular, the port industry. Therefore, it is useful for researchers to examine British port privatization in detail, particularly the implications of UK port privatization. Research design, data, and methodology - After reviewing the historical development of the UK port industry, the important factors determining the success of the British port privatization process were identified. The interpretations could be lessons for some other country to consider port privatization in near future. Results - The key factors in relation to port privatization are first, regulation; second, ownership; and third, utilities and operations, which includes autonomy, efficiency, and competitiveness. In addition, the UK port management system is a pure private port system, which has been successful. Conclusions - In Britain, after deciding to privatize the erstwhile public ports, they were fully privatized, focusing on the aforesaid key factors. This offers important lessons for the privatization of other ports in the world.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -2
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• pp.669-672
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• 2000

This paper deals with cryptography by applying RSA and Petri nets. Firstly, we introduce RSA cryptography and a Petri net based private-key cryptography. Then we propose a new public-key cryptography, Petri Net based Public-Key Cryptography dented as PNPKC, by taking the advantages of these two proposed cryptographys and give an example to show how to apply PNPKC. Finally, we do the comparison between RSA cryptography and PNPKC on security as well as computation order. As the results, the security of PNPKC is as strong as RSA cryptography and further the encryption and decryption of PNPKC are in average 210 times as fast as RSA cryptography from our experimental data.

• Asia pacific journal of information systems
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• 제30권1호
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• pp.21-30
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• 2020

Bitcoin (BTC) is a type of cryptocurrency that supports transaction/payment of virtual money between BTC users without the presence of a central authority or any third party like bank. It uses some cryptographic techniques namely public- and private-keys, digital signature and cryptographic-hash functions, and they are used for making secure transactions and maintaining distributed public ledger called blockchain. In BTC system, each transaction signed by sender is broadcasted over the P2P (Peer-to-Peer) Bitcoin network and a set of such transactions collected over a period is hashed together with the previous block/other values to form a block known as candidate block, where the first block known as genesis-block was created independently. Before a candidate block to be the part of existing blockchain (chaining of blocks), a computation-intensive hard problem needs to be solved. A number of miners try to solve it and a winner earns some BTCs as inspiration. The miners have high computing and hardware resources, and they play key roles in BTC for blockchain formation. This paper mainly analyses the underlying cryptographic techniques, identifies some weaknesses and proposes their enhancements. For these, two modifications of BTC are suggested ― (i) All BTC users must use digital certificates for their authentication and (ii) Winning miner must give signature on the compressed data of a block for authentication of public blocks/blockchain.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 추계학술대회
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• pp.359-362
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• 2009

공인인증서는 온라인 금융거래와 증권거래 등에서 사용자의 신원 확인을 위해 사용된다. 이때 사용자의 공개키는 공인인증서에 저장되며, 이 공개키에 대응되는 사용자의 개인키는 보안을 위해 사용자가 설정하는 패스워드로 암호화 되어 개인키 저장파일에 저장된다. 본 연구에서는 로컬에서 공인인증서에 접근하는 현재의 방식에 문제점을 지적하고 이를 해결할 수 있는 방법으로 모바일 공인인증서 관리 어플리케이션을 제안한다.

• 육아정책연구
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• 제12권3호
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• pp.3-27
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• 2018

본 연구는 유치원 교사의 하루 업무수행의 경향성을 분석하고, 업무시간 운영의 실제와 효율성에 대한 인식을 알아보기 위해 공사립유치원 교사 273명을 대상으로 설문조사를 실시하였다. 연구결과, 첫째, 유치원 교사들은 단위시간(30분)별로 평균 1.41개의 업무를 수행하였으며, 업무 내용에 있어 공립과 사립 간에 차이가 있었다. 둘째, 수업준비시간이 부족한 이유로 공립 교사들은 행정업무가 많아서, 사립 교사들은 행사나 공동 업무가 우선시 되어서를 꼽았고, 수업 외 업무에서 많은 시간을 소비하여 인력지원이 필요한 업무로 공립 교사들은 사무관련 업무, 사립 교사들은 행사관련 업무를 꼽아 차이를 보였다. 셋째, 업무시간의 효율적 운영과 관련해서는 공립과 사립 모두 업무량 과다를 매우 심각하게 보았고, 더불어 공립은 보조인력 부족, 사립은 행사관련 업무 과다 및 관리자의 리더십을 문제시 하였다. 이러한 결과는 유치원 교사의 업무량 적정화, 수업준비시간의 확보 및 업무 효율화, 기관유형에 맞는 지원이 필요함을 시사한다.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
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• pp.347-349
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• 2008

The primitive of Identity-Based Broadcast Encryption allows a sender to distribute session keys or messages for a dynamically changing set of receivers using the receiver's identity as a public key. We already know that the trade-off exists the efficiency between the public parameter size and the ciphertext size. So, if the ciphertext size is O(1), then the public parameter size may be O(n). Some of IBBE scheme take the public parameters as input in decryption phase. Thus, a decryption device (or client) has to store the public parameters or receive it. This means that a decryption device (or client) has to have the proper size storage. Recently, delerabl$\square$e proposed an IBBE which have the O(1) size ciphertexts and the O(n) size public parameters. In this paper, we present an IBBE scheme. In our construction the ciphertext size and the public parameter size are sub-linear in the total number of receivers, and the private key size is constant.

• Current Optics and Photonics
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• 제3권2호
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• pp.119-127
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• 2019

A new secret-key-sharing cryptosystem using optical phase-shifting digital holography is proposed. The proposed secret-key-sharing algorithm is based on the Diffie-Hellman key-exchange protocol, which is modified to an optical cipher system implemented by a two-step quadrature phase-shifting digital holographic encryption method using orthogonal polarization. Two unknown users' private keys are encrypted by two-step phase-shifting digital holography and are changed into three digital-hologram ciphers, which are stored by computer and are opened to a public communication network for secret-key-sharing. Two-step phase-shifting digital holograms are acquired by applying a phase step of 0 or ${\pi}/2$ in the reference beam's path. The encrypted digital hologram in the optical setup is a Fourier-transform hologram, and is recorded on CCDs with 256 quantized gray-level intensities. The digital hologram shows an analog-type noise-like randomized cipher with a two-dimensional array, which has a stronger security level than conventional electronic cryptography, due to the complexity of optical encryption, and protects against the possibility of a replay attack. Decryption with three encrypted digital holograms generates the same shared secret key for each user. Schematically, the proposed optical configuration has the advantage of producing a kind of double-key encryption, which can enhance security strength compared to the conventional Diffie-Hellman key-exchange protocol. Another advantage of the proposed secret-key-sharing cryptosystem is that it is free to change each user's private key in generating the public keys at any time. The proposed method is very effective cryptography when applied to a secret-key-exchange cryptosystem with high security strength.