• 한국컴퓨터정보학회논문지
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• 제17권11호
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• pp.83-91
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• 2012

사용자 익명성 제공 인증기법은 Das 등에 의해 처음으로 제안되었으며, 대부분의 사용자 익명성 기법들은 통신 채널상의 외부공격에 대한 사용자 익명성을 제공한다. 본 논문에서는 서버 공격에 의한 개인정보 노출 사고가 증가함에 따라, 외부공격에 대한 사용자 익명성뿐만 아니라 서버에 대한 사용자 익명성을 제공하는 새로운 인증기법을 제안한다. 더욱이 제안 인증기법은 원격 서버가 악의적인 사용자를 추적할 수 있는 기능을 제공하며, 패스워드 오입력시의 취약점을 개선하여 원격 서버의 계산로드가 증가하는 문제도 함께 해결한다.

• 한국통신학회논문지
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• 제38C권11호
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• pp.1078-1083
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• 2013

유비쿼터스 시대에 발맞춰 LED를 이용한 WPAN(Wireless Personal Area Network) 기술 개발이 진행 중이다. 그러나 LED를 이용한 가시광 통신은 통신 성능이 저하되는 취약점이 있다. 백열등, 형광등, 태양광선 등과 같은 광잡음으로 인한 정보의 손실을 줄이기 위해 채널 코딩 방식인 이중 이진 터보 코딩을 제안하고자 한다. 본 논문에서는 제안된 시스템의 부호화 방식을 설명하고 시뮬레이션 결과를 분석하여 제안한 이중 이진 터보 코딩을 이용하여 기존의 가시광 통신 시스템의 성능이 향상된 것을 확인할 수 있었다.

• KIEE International Transactions on Power Engineering
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• 제3A권4호
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• pp.214-221
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• 2003

In view of the fact that gas insulated switchgear (GIS) is an important piece of equipment in a substation, it is highly desirable to continuously monitor the state of equipment by measuring the partial discharge (PD) activity in a GIS, as PD is a symptom of an insulation weakness/breakdown. However, since the PD signal is relatively weak and the external noise makes detection of the PD signal difficult, it therefore requires careful attention in its detection. In this paper, the algorithm for detection of PD in the GIS using the wavelet transform (WT) is proposed. The WT provides a direct quantitative measure of the spectral content and dynamic spectrum in the time-frequency domain. The most appropriate mother wavelet for this application is the Daubechies 4 (db4) wavelet. 'db4', the most commonly applied mother wavelet in the power quality analysis, is very well suited to detecting high frequency signals of very short duration, such as those associated with the PD phenomenon. The proposed algorithm is based on utilizing the absolute sum value of coefficients, which are a combination of D1 (Detail 1) and D2 (Detail 2) in multiresolution signal decomposition (MSD) based on WT after noise elimination and normalization.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2001년도 추계종합학술대회
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• pp.199-202
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• 2001

본 논문에서는 21세기 해양시대를 맞이하여 21세기에 전개될 지식화, 정보화 및 세계화 둥 해양수산 전반적인 여건변화에 능동적인 대처를 위해 실천적인 국가 해양화 전략의 수단으로 해양 지리정보체계 구축을 실시하였을 때 기반이 되는 국ㆍ내외 사례들을 조사분석하여 해양GIS 구축에 기초자료로 이용하고자 한다. 본 논문은 GIS 관련기술이 발달되고 성숙한 단계에 이른 외국의 자료 및 사례조사를 위해서, 현재 GIS 선진국이라고 할 수 있는 미국을 중심으로 하여 외국의 해양기관을 대상으로 문헌조사와 인터넷 둥의 전자정보망을 이용한 사례조사 방법을 사용하였다. 활용사례연구는 그 적용분야에 따라 해양종합, 항만건설, 수산ㆍ어업, 해운물류, 해양안전 등 5개의 활용분야로 구분하여 조사하였으며, 각각의 사례에 대하여 관리운영주체, GIS시스템, 데이터베이스, 시스템내용 및 시스템의 장단점 등을 살펴서 우리나라의 해양GIS 개발정책 수립에 도움이 되는 시사점을 고찰하였다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 춘계종합학술대회
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• pp.925-927
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• 2005

The study is about a finite field multiplying unit, which performs a calculation t-times as fast as the Mastrovito's multiplier architecture, suggesting and using the 2-times faster multiplier architecture. Former studies on finite field multiplication architecture includes the serial multiplication architecture, the array multiplication architecture, and the hybrid finite field multiplication architecture. Mastrovito's serial multiplication architecture has been regarded as the basic architecture for the finite field multiplication, and in order to exploit parallelism, as much resources were expensed to get as much speed in the finite field array multipliers. The array multiplication architecture has weakness in terms of area/performance ratio. In 1999, Parr has proposed the hybrid multipcliation architecture adopting benefits from both architectures. In the hybrid multiplication architecture, the main hardware frame is based on the Mastrovito's serial multiplication architecture with smaller 2-dimensional array multipliers as processing elements, so that its calculation speed is fairly fast costing intermediate resources. However, as the order of the finite field, complex integers instead of prime integers should be used, which means it cannot be used in the high-security applications. In this paper, we propose a different approach to devise a finite field multiplication architecture using Mastrovito's concepts.

• 정보저장시스템학회논문집
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• 제10권2호
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• pp.50-54
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• 2014

Object image using DRPE(Double Random Phase Encryption) in 4f system is encrypted by space-division method using amplitude mask. However, this method has the weakness for the case of having partial data of amplitude mask which can access the original image. To improve the security, we propose the method using the 2-dimension logistic chaos function which shuffles the encrypted data. It is shown in simulation results that the proposed method is highly sensitive to chaos function parameters. To properly decrypt from shuffled encryption data, below 1e-5 % errors of each parameter should be required. Thus compared with conventional method the proposed shows the higher security level.

• 한국산학기술학회논문지
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• 제12권12호
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• pp.5895-5901
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• 2011

본 논문에서는 An[7]이 제안한 스킴이 패스워드 기반 스마트카드를 이용한 사용자 인증 스킴에서 고려하는 보안 요구사항을 만족하지 못함을 보였다. 이러한 보안 취약점을 해결하기 위하여 해시함수와 ElGamal 서명기반의 개선된 사용자 인증 스킴을 제안한다. 제안한 사용자 인증 스킴은 패스워드 추측공격, 위장공격, 재전송공격에 대응할 수 있고, 순방향 비밀성을 제공하는 스킴이다. 제안한 스킴은 An의 인증 스킴과 비교할 때,계산복잡도는 별 차이가 없이 유사하나, 안전성은 상대적으로 효율적임을 알 수 있다.

• Asia pacific journal of information systems
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• 제25권1호
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• pp.143-161
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• 2015

The South Asian Association for Regional Cooperation (SAARC) nations are a potpourri of diverse religions, races and cultures with rich natural and cultural heritage but yet to tap the full potential of tourism. An investigation into the glorifying heritage of these eight SAARC nations pinpoints towards their rich food and culinary heritage that is yet to be explored to carve them as food destinations that would definitely help ameliorating tourism too. The Global Report on Food Tourism of the United Nations World Tourism Organization (UNWTO) reveals results from a survey on food tourism marketing promotion, from which internet marketing tools, such as websites have been effectively utilized to promote food tourism in a particular destination. (UNWTO, 2012). Sensing the importance of the websites in the promotion of food tourism for any destination, the present study aims at the comparative content analysis of the official tourism websites of SAARC nations to evaluate their performance from the perspective of promotion of culinary heritage on world -wide web. The modified Balanced ScoreCard (BSC) approach is incorporated into the evaluation by taking into consideration four perspectives: technical, user friendliness and site attractiveness, tourism effectiveness and food tourism effectiveness. A set of 88 critical success factors representing these four perspectives is then used to examine the websites. The study reflects on the relative strength and weakness of the tourism websites of SAARC nations in promoting food tourism and as well help suggesting the remedial measures catalyzing the food tourism promotion through websites.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권9호
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• pp.3126-3145
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• 2014

Cloud computing is a computing paradigm in which users can rent computing resources from service providers according to their requirements. A spot instance in cloud computing helps a user to obtain resources at a lower cost. However, a crucial weakness of spot instances is that the resources can be unreliable anytime due to the fluctuation of instance prices, resulting in increasing the failure time of users' job. In this paper, we propose a Genetic Algorithm (GA)-based workflow scheduling scheme that can find the optimal task size of each instance in a spot instance-based cloud computing environment without increasing users' budgets. Our scheme reduces total task execution time even if an out-of-bid situation occurs in an instance. The simulation results, based on a before-and-after GA comparison, reveal that our scheme achieves performance improvements in terms of reducing the task execution time on average by 7.06%. Additionally, the cost in our scheme is similar to that when GA is not applied. Therefore, our scheme can achieve better performance than the existing scheme, by optimizing the task size allocated to each available instance throughout the evolutionary process of GA.

• 디지털산업정보학회논문지
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• 제15권2호
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• pp.43-52
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• 2019

The recent technological developments of smart devices, multiple services are provided to enhance the users' quality of life including smart city, smart energy, smart car, smart healthcare, smart home, and so on. Academia and industries try to provide the users with convenient services upon seamless technological research and developments. Also, whenever and wherever a variety of services can be used without any limitation on the place and time upon connecting with different types of devices. However, security weaknesses due to integrations of multiple technological elements have been detected resulting in the leakage of user information, account hacking, and privacy leakage, threats to people's lives by device operation have been raised. In this paper, safer communication framework is suggested by device control and user authentication in the mobile network environment. After implementations of registration and authentication processes by users and devices, safe communication protocol is designed based on this. Also, renewal process is designed according to the safe control of the device. In the performance evaluation, safety was analyzed on the attack of protocol change weakness occurred in the existing system, service halt, data leakage, illegal operation control of message, and so on, which confirmed the enhanced speed approximately by 8% and 23% in the communication and verification parts, respectively, compared to the existing system.