• Journal of Korean Institute of Industrial Engineers
• /
• v.40 no.1
• /
• pp.140-150
• /
• 2014

University ranking models, though they consider multiple indicators to evaluate universities, determine the overall score of each university based on their own normalization and aggregation methods. Thus, the rankings provided by such models primarily depend on actual scores of evaluation indicators, but they are also significantly affected by the normalization and aggregation methods. We examine the normalization methods of four university ranking models used in South Korea, China, and United Kingdom. We discuss a possible unintended consequence of these methods, i.e., some universities who want to improve their rankings may focus on unnecessary indicators, contrary to the evaluator's intension, due to the normalization methods. We suggest a new normalization method based on the statistical characteristics of the distribution of each evaluation indicator so that the new method can motivate the universities to move into the desirable directions intended by the evaluator.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.23 no.4
• /
• pp.355-362
• /
• 2020

EFP composed of explosive, charge and liner generally penetrates standoff a target by Monroe effect. Its performance highly depends on penetrator characteristics and flight stability. Penetration ability can be dramatically reduced when the penetrator reaches the target with AOA, even if the penetrator has high kinetic energy and L/D ratio. Therefore, it is important to research not only penetrator characteristics and but also flight stability. In this work, the effect of liner shape on penetrator characteristics was examined using free flight test and numerical tools. It was found that tip velocity of penetrator was increased with decreasing liner thickness. It was also found that thicker liner had higher static margin leading to better flight status.

• Proceedings of the Korean Information Science Society Conference
• /
• 2005.07a
• /
• pp.163-165
• /
• 2005

유비쿼터스 환경이 도래하면서 언제, 어느 곳에서든 네트?을 사용하여 정당한 사용자임을 확인하고자 하는 요구가 증대하고 있다. 기존의 사용자 인증 방식은 인증기관으로부터 받은 인증서와 비밀키를 하드웨어 장치나 스마트카드 등의 보조 기억장치에 저장하여 휴대하고 다녀야 하는 번거로움이 있다. 또한 사용자의 비밀키를 키위탁 센터에 위탁하여 필요할 때 사용할 수 있도록 하고 있으나 여러 가지 위협으로부터 안전할 수 없는 상황이다. 본 논문에서는 이러한 휴대의 불편함과 여러 가지 위협으로부터 보호하고, 사용자가 언제 어디서든 인증을 제공받을 수 있는 동적 키생성 및 키복구 모듈을 제안한다.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.63 no.1
• /
• pp.123-131
• /
• 2014

An INS/vision integrated navigation algorithm is proposed for environments with insufficient number of landmarks. In the proposed algorithm, the raw measurements on the focal plane are directly used in order to cope with the situation where the number of landmarks are not sufficient. In addition to this, the combination of landmarks, which has smallest value of DOP, is used in the update of measurement in order to improve navigation performance. In order to evaluate the performance of the proposed integrated navigation system, Monte-Carlo simulation and van test was performed. The results of the simulation and experiment show that the proposed navigation system gives better navigation performance than an INS/vision integrated navigation system which does not use the raw measurements on the focal plane and the navigation system provides navigation solutions even in environments with insufficient number of landmarks.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2015.10a
• /
• pp.541-543
• /
• 2015

최근 스마트폰 카메라를 이용하여 심방세동을 진단하기 위해 PPG를 이용하여 Pulse Peak 사이의 간격을 구하고 RMSSD와 섀넌 엔트로피를 이용하여 불규칙 정도를 계산하는 연구가 활발히 진행되고 있다. 본 논문에서는 심방세동 환자와 정상인을 포함한 한국인을 대상으로 스마트폰을 이용한 심방세동 검출을 실험하고 정확률을 계산하였다. 심방세동 환자를 포함한 한국인 29명을 대상으로 PPG 신호를 수집하여 실험하였다. 실험결과에서 정확률 85.18%를 보였다.

• Journal of the Korean Chemical Society
• /
• v.63 no.5
• /
• pp.323-326
• /
• 2019

• Journal of the Optical Society of Korea
• /
• v.17 no.6
• /
• pp.467-470
• /
• 2013

We propose a blind feedforward phase noise mitigation method in the time-domain for a coherent optical orthogonal frequency division multiplexing (CO-OFDM) systems. By exploiting the redundancy of the cyclic prefix (CP), the proposed scheme acquires the overall phase noise difference information during an OFDM block and attempts to mitigate the phase noise in the time domain using a linear approximation. The proposed algorithm mitigates common phase error (CPE) and inter-carrier-interference (ICI) due to phase noise simultaneously, improving the system performance, especially when decision-directed equalizers are used. The simulation results demonstrate the effectiveness of the proposed feedforward phase noise mitigation approach in time domain.

• Current Optics and Photonics
• /
• v.5 no.2
• /
• pp.93-100
• /
• 2021

Three factors that degrade the accuracy of modal decomposition are extensively studied using simulated and measured beams. These include a beam size mismatch, beam center mismatch, and signal-to-noise ratio of the images. The beam size and beam center are scanned using simulated noisy beams, and the result of the modal decomposition is compared with that of real beams. Based on the suggested procedure, error functions of approximately 1-4 × 10-3 can be acquired for real beams. This study provides important information regarding the impact of the three factors on the practical modal decomposition and tolerances of a mismatch, helping estimate the achievable values of the error function in a real beam modal decomposition.

• Journal of the Architectural Institute of Korea Planning & Design
• /
• v.36 no.1
• /
• pp.15-26
• /
• 2020

The purpose of this study is to develop every possible real-time evacuation scenarios for large-scale buildings which considering continuously changing conditions during the events. From the review of the previous studies on smartphone-based real-time evacuation systems, this study proposed the customized egress scenarios. The scenario considered the characteristics of facilities, disaster types, and individual factors of evacuees. This study verified the proposed process for real-time evacuation scenarios by applying the several actual fire cases happened recently in Korea. Based on the result of this research, necessary technologies for the real-time evacuation systems are identified and can be applied to develop the more effective evacuation system.

• Journal of the Architectural Institute of Korea Planning & Design
• /
• v.35 no.12
• /
• pp.3-12
• /
• 2019

The purpose of this study is to address the Issues on Architectural Plagiarism through the analysis of the discourses written in texts form. This study selected 60 texts of 20 suspected pairs of architectural plagiarism to derive key-words and key-passages to understand the Issues on Architectural Plagiarism. As a result, the Issues on Architectural Plagiarism are categorized into six different topics; Prototype, Archetype, Motif, Expression of Idea, Commodification, and Westernized-modernization. Meanwhile, the six issues were not discussed independently, but several issues were considered simultaneously in individual cases. This study is the first step to establish the objective guideline to judge Architectural Plagiarism and to be a basis in Architectural Plagiarism research.