• The KIPS Transactions:PartC
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• v.15C no.2
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• pp.125-132
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• 2008

As the development of Internet technology, the number of IDs managed by each individuals has been increased. And many software development institutes have developed ID/PW management solutions to facilitate secure and convenient management of ID/PW. However, these solutions also can be vulnerable in case of administrator's password exposure. Thus, we need to derive security requirements from the vulnerability analysis of these solutions, also we need evaluation criteria for secure ID/PW management solution development. In this paper, we analyze the vulnerability of ID/PW management solution and propose the evaluation criteria for secure ID/PW management solution.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.5
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• pp.413-418
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• 2002

This paper proposed a feed-forward adaptive position controller that is robust for variable Inertia. The control system consists of PI Position controller, feed-forward and model reference adaptive control. A parameter g(t) of the feed-forward adaptive position controller is adapted by using both the reference model speed and position error. So it improves the transient response and reduces the settling time. And normalization function Is used to make linear adaptation time. The validity of the feed-forward adaptive controller is confirmed by simulation results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.3C
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• pp.209-214
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• 2003

Multi-mode coding method is a reliable DC-suppression method. There are two ways to improve the DC-suppression performance. One is improving scrambler's performance, and the other is improving selection criteria. The latter uses the MRDS(minimum running digital sum) criterion. It is easy to calculate, but its performance goes down when the length of codeword is getting longer. The MSW(mean squared weight) criterion that is known as the best so far regardless of the length of codeword has the high complexity. In this paper, we present the new selection criteria, MPRDS(minimum peak RDS) and A BSRDS(absolute RDS). Their performance are close to the MSW, implementation is simple. And also we present the SC(sign change) that has a subsidiary role with the original selection criteria and improve the capacity.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.1A
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• pp.13-17
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• 2002

For elimination DC component, the optical recording systems generally exploit WRDS (word-end running digital sum) criterion. However, its performance is degraded if the lengths of the control bits and codewords are increased. Another criterion is MSW (mean-square weight) method. Whereas MSW criterion has the complexity, this hs optimal performance. In this paper, we have proposed a new dc-component suppression method (MPRDS, minimum peak RDS) of the modulation codes for high density optical recording system. This method requires less complexity than MSW's, and the performance is near to MSW's even if the lengths of the control bits and codewords are increased.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.154-157
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• 2002

본 연구는 관성의 변화, 비선형 마찰 등에 견실한 피드포워드 적응 위치제어기를 제안한다. 제안된 적응 위치제어기의 특징은 제어기 적응파라미터가 위치오차에 기준모델의 속도 정보를 받아들여 셀프 튜닝된다. 이것은 과도응답 특성을 향상시키고, 정상상태의 수렴 시간을 줄여 시스템의 성능을 개선시킨다. 시뮬레이션을 통하여 제안된 피드포워드 적응 위치제어기의 동작과 설계 방법의 타당성을 보였다.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.9
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• pp.215-224
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• 2012

Using password on system is easy to build and shorten the access time to authorize user, which is high in use for vary system that requires users' authorization. Many input device are able to perform the password system easily, such as PC, smart-phone, tablet PC, etc. Beside the high usability of password, physical attack occurs when user put their password on the device, known as Shoulder Surfing attack. It used to be formed in numbers, characters or mix of different kinds, but new kind of password arose. Exploiting image or making scenarios are those kinds which are able to reflect users' intentions. Not many estimation exists for new password, so there's need to be standard for those new password for highlighting usability and accessability. In this paper, we propose password system with simple image and switching key-board to test statistical method to estimate usability on the password.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.12
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• pp.463-478
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• 2014

Portal site is not only providing search engine and e-mail service but also various services including blog, news, shopping, and others. The fact that average number of daily login for Korean portal site Naver is reaching 300 million suggests that many people are using portal sites. With the increase in number of users followed by the diversity in types of services provided by portal sites, the attack is also increasing. Most of studies of password authentication is focused on threat and countermeasures, however, in this study, we analyse the security threats and security requirement of membership, login, password reset first phase, password reset second phase. Also, we measure security score with common criteria of attack potential. As a result, we compare password authentication system of domestic and abroad portal sites.

• Review of KIISC
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• v.9 no.4
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• pp.51-64
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• 1999

클라이언트 측의 사용자들이 응용서버(application server)로 부터의 서비스를 받기위 해서는 사요자간에 또는 사용자와 암호시스템 간에 인증은 필수적인 요구조건이다. 이러한 인증과정은 현재 사용자가 통신을 통해 정보를 교환하고 있는 상대가 실제 의도한 상대인지 를 확인하는 과정을 의미한다. 따라서 이러한 문제를 해결하기 위한 보다 효율적이고 안전 한 프로토콜의 개발이 절실하며 본논문에서는 이를 위해 기존에 제시되어진 패스워드를 이 용한인증프로토콜들을평문등가(plaintext-equivalent)프로토콜과 확인자 기반(verifiier-based) 프로토콜로 나누어 고찰해 보고 이들을 안정성, 그리고 연산속도 메시지 전송횟수를 기준으 로 비교 분석해 보고자 한다.

• Journal of The Korean Association of Information Education
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• v.19 no.4
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• pp.409-418
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• 2015

The purpose of this study is derived implications at software curriculum development utilizing the backward design model. In this study, we developed 'Algorithms and Programming' unit teaching plan based on backward design template. First, we have derived enduring understandings, essential questions, specific knowledge and skill on 'Algorithms and Programming' unit by considering the goal, content, achievement standard of Software education operating instructions. Second, we developed authentic tasks using GRASPS technic and holistic scoring rubrics. Third, we developed 7 lesson 14 WHERETO element for effective teaching in 'Algorithms and Programming' unit. Fourth, we investigated about the effectiveness of the development unit based on backward design. Backward design could be useful of developing curriculum unit and lesson plan at software education.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.4
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• pp.661-674
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• 2021

Edwardsiellosis is difficult to treat in cultured olive flounder, Paralichthys olivaceus. It is present in the fish for a long period during all growth stages, and it often leads to mass mortalites. In this paper, the clinical patterns of Edwardsiellosis were analyzed by dividing the data into the whole-water temperature, low-water temperature, low-high water temperature, high-water temperature, and high-low water temperature groups based on various clinical signs of diseased cultured olive flounder using a decision tree technique. In the clinical sign patterns in the decision trees analyzed in the experiment, clinical signs in the liver, such as liver nodules, liver hemorrhages, and liver degeneration, were selected as the criteria for determining Edwardsiellosis. The selected clinical signs were known as the major clinical signs of Edwardsiellosis, and through consultation with fishery disease experts, the analysis confirmed that the clinical signs of Edwardsiellosis were successfully found in this study.