• 시큐리티연구
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• 제8호
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• pp.379-407
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• 2004

The cyber-crime is one of the results occurring from the increased dependency toward information-telecommunication devices. Currently, the Korean National Police Agency and many other related law enforcement agencies have made efforts to respond against the cyber-crimes. However, the number of cyber-crime is increasing steadily. The worse problem is that the arresting rate for the cyber-crime has been decreased than before. The reasons of decreasing arresting rate come from many different kinds of cyber-crime methods with the developed computer and network technology, Also, the easy concealment of the cyber-crime by the violater and the difficulty of specification against the data objected to search and seizure make the crackdown difficult. The other difficulties come from the lack of professionally trained investigators, the lack of high-technological investigation devices, and the failure of the technology development for the search and seizure of evidences because of the budget deficit. That is to say, these phenomenon show the comprehensive problem of the cyber-police system. Accordingly, to respond against newly changed cyber-crime activities and to investigate effectively, the cyber-police has to take consideration into the professional reorganization of the cyber-police, the development of the investigation technology, and the adjustment of current cyber-crime laws. Most importantly, the cyber-police needs the high-technological investigation devices, the development of the investigation methods, and the training for the professional human resources with the enough budget support.J

• Management Science and Financial Engineering
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• 제14권2호
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• pp.89-104
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• 2008

Growth curves including Bass, Logistic and Gompertz functions are widely used in forecasting the market demand. Nonlinear least square method is often adopted for estimating the model parameters but it is difficult to set up the starting value for each parameter. If a wrong starting point is selected, the result may lead to erroneous forecasts. This paper proposes a method of selecting starting values for model parameters in estimating some growth curves by nonlinear least square method through grid search and transformation into linear regression model. Resealing the market data using the national economic index makes it possible to figure out the range of parameters and to utilize the grid search method. Application to some real data is also included, where the performance of our method is demonstrated.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2004년도 추계학술대회
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• pp.299-304
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• 2004

With the development of mobile and wireless environments, the Ubiquitous era has com on the base of technologies of Semantic Web and Web Services. To accelerate proliferation of the E-Commerce in the Ubiquitous era, the importance of information search is emphasized more and more and its time to need more intelligent search for product and service which can consider location and other context-aware related information. As a starting point to meet these requirements, we proposed more effective product information search service framework through web services under semantic web environment. Over the wireless internet and we also examined its technical validity with the prototype system, implemented prototype and investigated the technological possibility.

• 지식경영연구
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• 제16권4호
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• pp.1-16
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• 2015

This paper aims to explore the small and medium sized enterprises'(SMEs') technological innovation through an open innovative strategy. Researchers have identified open innovation as external search 'breadth' and 'depth'. Although an open innovation strategy is well known as an effective way for SMEs' innovation, this stream of research examines differences between pursuing breadth of external knowledge and depth of external knowledge for SEMs' innovation. The sample comprises a total of 1106 SMEs included in the Korean Innovation Survey, and logistic regression analysis and odds ratio comparison were used to evaluate the relationship between external knowledge search and innovation outcomes. The results show that both 'breadth' and 'depth' positively affect the SMEs' innovation. When SMEs are simultaneously pursuing external searching for breadth and depth, however, a negative result on innovation outcome followed because of the lack of their internal resources and capacities. Despite these contributions, we have certain limitations that can be regarded as means of future research. Even though breadth and depth are adopted to measure the way of how a firm sources the external knowledge, companies may place the different weight on each source of knowledge. And also, it is difficult to understand how the knowledge gained through external search contributes to a firm's incremental and radical innovation, respectively.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권11호
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• pp.3937-3954
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• 2014

With the increasing electricity consumption and the wide application of renewable energy sources, energy auction attracts a lot of attention due to its economic benefits. Many schemes have been proposed to support energy auction in smart grid. However, few of them can achieve range query, ranked search and personalized search. In this paper, we propose an efficient multi-keyword range query (EMRQ) scheme, which can support range query, ranked search and personalized search simultaneously. Based on the homomorphic Paillier cryptosystem, we use two super-increasing sequences to aggregate multidimensional keywords. The first one is used to aggregate one buyer's or seller's multidimensional keywords to an aggregated number. The second one is used to create a summary number by aggregating the aggregated numbers of all sellers. As a result, the comparison between the keywords of all sellers and those of one buyer can be achieved with only one calculation. Security analysis demonstrates that EMRQ can achieve confidentiality of keywords, authentication, data integrity and query privacy. Extensive experiments show that EMRQ is more efficient compared with the scheme in [3] in terms of computation and communication overhead.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권10호
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• pp.4873-4888
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• 2018

A joint blind parameter estimation algorithm based on minimum channel stability function aimed at the non-cooperative high-order modulated paired carrier multiple access (PCMA) signals is proposed. The method, which uses hierarchical search to estimate time delay, amplitude and frequency offset and the estimation of phase offset, including finite ambiguity, is presented simultaneously based on the derivation of the channel stability function. In this work, the structure of hierarchical iterative processing is used to enhance the performance of the algorithm, and the improved algorithm is used to reduce complexity. Compared with existing data-aided algorithms, this algorithm does not require a priori information. Therefore, it has significant advantage in solving the problem of blind parameter estimation of non-cooperative high-order modulated PCMA signals. Simulation results show the performance of the proposed algorithm is similar to the modified Cramer-Rao bound (MCRB) when the signal-to-noise ratio is larger than 16 dB. The simulation results also verify the practicality of the proposed algorithm.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권4호
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• pp.1442-1462
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• 2014

Packet classification is a key technology of the Internet for routers to classify the arriving packets into different flows according to the predefined rulesets. Previous packet classification algorithms have mainly focused on search speed and memory usage, while overlooking update performance. In this paper, we propose PreCuts, which can drastically improve the update speed. According to the characteristics of IP field, we implement three heuristics to build a 3-layer decision tree. In the first layer, we group the rules with the same highest byte of source and destination IP addresses. For the second layer, we cluster the rules which share the same IP prefix length. Finally, we use the heuristic of information entropy-based bit partition to choose some specific bits of IP prefix to split the ruleset into subsets. The heuristics of PreCuts will not introduce rule duplication and incremental update will not reduce the time and space performance. Using ClassBench, it is shown that compared with BRPS and EffiCuts, the proposed algorithm not only improves the time and space performance, but also greatly increases the update speed.

• 전자통신동향분석
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• 제39권2호
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• pp.93-102
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• 2024

As the scale of research and development (R&D) increases, countries and companies are consistently establishing R&D directions to meet strategic goals and market demands as well as roadmaps to increase efficiency through concentration and selection. However, establishing an effective roadmap and discovering promising technologies are challenging under the current numerous technological possibilities and uncertainties. The importance of discovering promising technologies to secure future technological competitiveness is recognized worldwide, and Europe, the United States, and Japan are establishing processes to identify promising future technologies and support related R&D. Methods for discovering promising future technologies can be classified into future social needs analysis, forecasting, surveys, use of expert opinions, and data analysis. We describe the types and limitations of technology roadmaps and investigate the status of domestic and foreign organizations using weak signal search through quantitative data analysis.

• 한국문헌정보학회지
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• 제46권1호
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• pp.99-117
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• 2012

본 연구의 목적은 최근 독서 매체로 급부상하고 있는 전자책을 중심으로 어린이 이용자들의 접근 및 탐색 모형을 제시하고자 하였다. 이를 위해 먼저 문헌정보학 분야의 정보탐색행태에 관한 문헌 연구를 고찰하여 기초 모형안을 설계하였다. 다음으로 서울 경기 지역의 5개 도서관 이용자인 남녀 초등학생 30명을 대상으로 면담 및 관찰 조사를 수행하였다. 이를 바탕으로 제시된 어린이 이용자의 전자책 접근 및 탐색 모형안을 수정하여 맥락내의 어린이 이용자, 실행기제, 중재변수, 정보추구행위 및 전략, 정보원 선택, 이용으로 이어지는 순환형 모형으로 제안하였다.

• 디지털콘텐츠학회 논문지
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• 제18권2호
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• pp.373-382
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• 2017

과학기술콘텐츠가 증가함에 따라 과학기술콘텐츠의 효율적인 검색을 지원하는 서비스가 요구되고 있다. 저자의 소속기관명을 키워드로 사용할 경우 한 기관에서 생산된 콘텐츠를 확인할 수 있을 뿐만 아니라 저자, 용어를 키워드로 사용한 검색 결과의 식별율을 향상 시킬 수 있다. 검색 키워드로 사용되는 데이터들의 중의성과 모호성으로 인해 검색 결과에 false negative, false positive가 포함될 수 있으므로 데이터의 식별을 통한 통제는 중요하다. 저자의 소속기관명의 식별을 통한 통제 역시 기관의 이명, 약어 검색을 지원가능하게 하므로 매우 중요하지만 기존의 데이터 식별을 통한 통제에 대한 연구는 저자, 용어에 대한 연구가 주를 이루었다. 본 연구에서는 기관명 식별 알고리즘을 제안하고, 한국과학기술정보연구원에서 보유하고 있는 국내 과학기술콘텐츠들에 대한 데이터를 이용한 실험 결과를 보인다.