• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.3
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• pp.1348-1375
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• 2018

Support Vector Machine (SVM) is a well-known machine learning classification algorithm, which has been widely applied to many data mining problems, with good accuracy. However, SVM classification speed decreases with increase in dataset size. Some applications, like video surveillance and intrusion detection, requires a classifier to be trained very quickly, and on large datasets. Hence, this paper introduces two filter-based instance selection techniques for optimizing SVM training speed. Fast classification is often achieved at the expense of classification accuracy, and some applications, such as phishing and spam email classifiers, are very sensitive to slight drop in classification accuracy. Hence, this paper also introduces two wrapper-based instance selection techniques for improving SVM predictive accuracy and training speed. The wrapper and filter based techniques are inspired by Cuckoo Search Algorithm and Bat Algorithm. The proposed techniques are validated on three popular e-fraud types: credit card fraud, spam email and phishing email. In addition, the proposed techniques are validated on 20 other datasets provided by UCI data repository. Moreover, statistical analysis is performed and experimental results reveals that the filter-based and wrapper-based techniques significantly improved SVM classification speed. Also, results reveal that the wrapper-based techniques improved SVM predictive accuracy in most cases.

• Journal of the Korean Operations Research and Management Science Society
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• v.26 no.3
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• pp.21-37
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• 2001

Riding on the wave of the information technology revolution, a slow of internet venture businesses (IVB) came into being. Hence, one of the recent developments in Korean capital market has been the proliferation of IVB, which is in accordance with the worldwide trend of ‘new economy’. Although the fair valuation is crucial for the nourishment of IVB, it is difficult to apply traditional valuation methods to these firms without reservation. It is due to the facts that most venture firms have little records of performance, grow unprecedently fast, and have highly uncertain future. The main purpose of this study is to suggest performance evaluation system of IVB and to develop KPE (Key Performance Indicators). Our empirical study is based upon Kaplan & Norton’s Balance Scorecard (BSC) approach. Specifically, our research has been conducted by the following two subsequent procedures: Firstly, seven internet venture firms have been selected and their executives have been interviewed by FGI(Focus Group Interview) method. Based upon these results, performance indicators have been developed. Secondly, by using the above mentioned BSC items (i.e., financial perspective, customer perspective, internal perspective and innovation & learning perspective), questionnaires have been constructed and sent to IVB through e-mail as well as over the Fax. Among the collected 110 samples, reliable 106 samples have been used to build BSC model and to draw our conclusion. In the future study, it would be much better to consider the role of strategy in IVB and the causal relationship among Key Performance Indicators of BSC.

• The Journal of Society for e-Business Studies
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• v.23 no.3
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• pp.173-187
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• 2018

After Satoshi Nakamoto published 'Bitcoin: A peer-to-peer electronic cash system' in 2008, Blockchain has been GPT (General Purpose Technologies) that affect the whole cycle of the $4^{th}$ Industrial Revolution. This study attempted to identify the innovativeness of Blockchain. Because of Blockchain's ambidextrous characteristics, Blockchain has two kinds of innovativeness, technological innovation by physical technology and social innovation by social technology. Thus, this study will be useful to increase understanding and establishing strategy for Blockchain.

• The Korean Journal of Archival Studies
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• no.75
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• pp.91-134
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• 2023

The presidential records of the participatory government transferred to the Presidential Archives are the result of innovation in the record production system symbolized by the document management card of the e-jiwon system. Records reveal the policy-making process by documenting the decision-making process. This study identified the existing forms of records related to records management innovation produced by the Office of the Records Management Secretary at the Office of the President, and reorganized them into functions-activities-subjects-actions. Thematic record types help to systematically understand the evolution of the matter and the nature of the record. The characteristics of each record were identified by writing detailed information on the record. These attempts are meaningful in that they provide basic data for the evaluation and use of presidential records.

• Information Systems Review
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• v.23 no.3
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• pp.177-200
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• 2021

Recently, the use of prepaid electronic payments such as electronic wallets, digital currency and prepaid points is gradually increasing. Prepaid electronic payments has the characteristic of being used after charging first. This study empirically investigated the factors affecting the intention to use online charging in order to help improve the service that require prepaid recharge by applying transformed TAM. Since there are not many previous studies for the intention to use online charging, we extract factors through preceding researches for electronic cash and mobile easy payment. Also we analyze the intention to use online charging for transportation card users, focusing on the moderating effects. As a result of the study, it was found that 'convenience', 'ubiquity', and 'self-efficacy' among the independent variables had a positive (+) effect on mediation variable 'perceived usefulness'. 'Perceived usefulness' was analyzed to have a significant influence on the dependent variable 'usage intention'. According to users' gender, internet usage time, internet shopping frequency, online charging frequency and transportation card usage type, the moderating effect was significant on 'perceived usefulness' and 'usage intention'. As an implication, it was suggested that service improvement and differentiated marketing are needed in direction of increasing the usefulness of services. Additional research directions were proposed for services such as e-wallets, prepaid points and digital currencies by adding other factors and moderate variables.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.607-610
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• 2008

Phishing is a form of online identity theft that aims to steal sensitive information such as online banking passwords and credit card information from users. Phishing scams have been receiving extensive press coverage because such attacks have been escalating in number and sophistication. According to a study by Gartner, Many Internet users have identified the receipt of e-mail linked to phishing scams and about 2 million of them are estimated to have been tricked into giving away sensitive information. This paper presents a novel browser extension, AntiPhish, that aims to protect users against spoofed web site-based phishing attack.

• Journal of the Chungcheong Mathematical Society
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• v.20 no.4
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• pp.355-366
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• 2007

In this paper, we propose a new blind group identification protocol and a hidden group signature protocol as its application. These protocols involve many provers and one verifier such that (1) the statement of all the provers are proved simultaneously, (2) and also all the provers using computationally limited devices (e.g. smart cards) have no need of computing the bilinear pairings, (3) but only the verifier uses the bilinear pairings. A. Saxena et al. proposed a two-round blind (group) identification protocol in 2005 using the bilinear pairings. But it reveals weakness in the active-intruder attack, and all the provers as well as the verifier must have devices computing bilinear pairings. Comparing their results, our protocol is secure from the active-intruder attack and has more fit for smart cards. In particular, it is secure under only the assumption of the hardness of the Discrete-Logarithm Problem in bilinear groups.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.2
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• pp.724-737
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• 2020

Corrected Block TEA(or XXTEA) is a block cipher designed to correct security weakness in the original block TEA in 1998. In this paper, XXTEA cipher hardware which can encrypt or decrypt between 64-bit and 256-bit messages using 128-bit master key is implemented. Minimum message block size is 64-bit wide and maximal message block size is 256-bit wide. The designed XXTEA can encrypt and decrypt variable-length message blocks which are some arbitrary multiple of 32 bits in message block sizes. XXTEA core of this paper is described using Verilog-HDL and downloaded on Vertex4. The operation frequency is 177MHz. The maximum throughput for 64-bit message blocks is 174Mbps and that of 256-bit message blocks is 467Mbps. The cryptographic IP of this paper is applicable as security module of the mobile areas such as smart card, internet banking, e-commerce and IoT.

• The Journal of Information Technology and Database
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• v.6 no.1
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• pp.89-101
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• 1999

Increasing number of companies recognize that the understanding of customers and their markets is indispensable for their survival and business success. The companies are rapidly increasing the amount of investments to develop customer databases which is the basis for the database marketing activities. Database marketing is closely related to data mining. Data mining is the non-trivial extraction of implicit, previously unknown and potentially useful knowledge or patterns from large data. Data mining applied to database marketing can make a great contribution to reinforce the company's competitiveness and sustainable competitive advantages. This paper develops the classification model to select the most responsible customers from the customer databases for telemarketing system and evaluates the performance of the developed model using LIFT measure. The model employs the decision tree algorithm, i.e., CHAID which is one of the well-known data mining techniques. This paper also represents the effective database marketing strategy by applying the data mining technique to a credit card company's telemarketing system.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.577-580
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• 2006

상품을 구입할 때 사용자의 신체 정보를 적용한 스마트카드를 이용하는 것은 전자상거래를 지원하는 현재의 E-business 시스템에 새로운 변화를 가져올 것이다. 사람의 신체는 모든 부분을 식별할 수 있는 다양한 물리적 측정 기준을 가지고 있다. 중요한 것은, 스마트카드는 바디 메트릭을 저장하기위해 적절한 저장장치이고, 그것과 관련된 컨텐츠의 자바 애플릿의 검색이나 업데이트가 용이하다는 점이다. 만약 고객의 신체 정보가 모바일 스마트카드에 저장되어 사용된다면, 그것은 상거래 프로세스에 효율적인 확장을 가져올 것이다. 이 논문은 웹 브라우저와 자바 임베디드 스마트카드사이의 일정한 접근 인터페이스를 개발, 제공하기위한 자바카드 웹 서비스의 프레임워크를 설명할 것이다.