• Journal of ILASS-Korea
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• v.10 no.4
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• pp.26-31
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• 2005

Today, the research to examine a fact that interaction between the air and the fluid free surface affects the steady state flow and air. We proved the interaction between vortex pairs and free surface on each condition that is created by the end of delta wings. Another purpose of this study is to investigate the effect of surface active material which call change the surface tension and we must consider when we refer to turbulent flow on surface tension. Therefore, this research examined the growth process of vortex pairs on condition of clean, contaminated free surface and wall after we made vortex pairs through counter rotating flaps. The results of this study suggest that vortex pairs in clean free surface rise safely but the vortex pairs in contaminated free surface and rigid, no slip is made secondary vortex or rebounding. However the secondary vortex in rigid, no slip is stronger than before. and we can find the vortex shape which roll up more completely. However, these will disappear by the effect of wall.

• Korean Journal of Logic
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• v.16 no.2
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• pp.155-187
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• 2013

The main objective of this paper is to vindicate the Bayesian belief updating rule, i.e. conditionalization. For this purpose, I introduce first what I call Irrelevance Principle, and show that this principle is equivalent to conditionalization. In turn, the principle is vindicated by means of Bayesian confirmation theory. That is, I suggest some theses that Bayesian confirmation theorists should accept, and prove that if Irrelevance Principle is violated, the theses cannot holds.

• Textile Coloration and Finishing
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• v.6 no.1
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• pp.1-7
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• 1994

A low-temperature dyeing system for silk fabrics based on a redox system has been investigated. Some factors affecting dyeing of silk fabrics with levelling acid dyes in the absence and presence of certain redox system were investigated under different conditions. The variables studied were; type and concentration of redox system, dyeing conditions, i. e. temperature and time, dye concentration, material-to-liquor ration(LR) and colour fastness. The colour strength(K/S value) is outstandingly higher in the presence than in the absence of redox system. A comparison between the colour strength values of such dyeings abtained the three redox system would call for the following order ; Glyoxal/hydrogen peroxide>thiourea/hydrogen peroxide>glucose/hydrgen peroxide> nothing. In the presence of redox system, free radicals are supposed to be formed in both the fiber and the dye and the interaction between these free radicals bring about covalent fixation beside the usual electrostatic bonds, hydrogen bonds and Van der Waals forces.

• Journal of Korea Society of Digital Industry and Information Management
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• v.4 no.3
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• pp.33-43
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• 2008

As internet is spreaded widely, the number of cyber terror using hacking and virus is increased. Also the hacking to the internet shopping mall go on increasing. If the large shopping mall is attacked by the hacker, a number of user's information are exposed to the hacker. The private information as like a resident registration number, user's real name, the date of user's birth, the mobile phone number, the office phone number / address, the home phone number / address and so on include the information. These information are used in the phishing e-mails / call and spam. And them are selling and buying maliciously. The large internet shopping mall 'auction' was hacked in April, 2008. After the incident, this paper suggested a countermeasures on the hacking for the internet shopping mall. The technical item and political item are included among the countermeasures. The countermeasures can protect the hacking not only the internet shopping mall but also the web sites basically.

• Annual Conference of KIPS
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• 2001.04a
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• pp.235-238
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• 2001

프로그램 수행시간의 대부분이 루프 구조에서 소비되고 있기 때문에 순차 프로그램을 병렬 프로그램으로 변환하는 연구들이 많이 행해지고 있고 그 연구들은 하나의 프로시저 내 루프 구조의 변환에 치중되고 있다. 그러나 대부분의 프로그램들은 프로시저 간 잠재된 병렬성을 가지고 있다. 본 논문에서는 프로시저 호출을 가진 루프에서 병렬성 추출 방식을 제안한다. 프로시저 호출을 포함하는 루프의 병렬화는 대부분 uniform 형태의 코드에서만 집중되었다. 본 논문에서는 uniform 코드, nonuniform코드 그리고 복합된(complex) 코드를 제안된 알고리즘과 loop extraction, loop embedding방법을 CRAY-T3E로 성능 평가하였다. 그리고 제안된 알고리즘이 효율적인 방법이라는 것을 보여준다.

• Bulletin of the Korean Chemical Society
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• v.3 no.3
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• pp.122-129
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• 1982

In order to extend our understanding on the multiple inhibition enzyme kinetics, a general equation of an enzyme reaction in the presence of two different reversible inhibitors was derived by what we call "match-box mechanism" under the combined assumption of steady-state and quasi-equilibrium for inhibitor binding. Graphical methods were proposed to analyze the multiple inhibition of an enzyme by any given sets of different inhibitors, i.e., competitive, noncompetitive, and uncompetitive inhibitors. This method not only gives an interaction factor $({\alpha})$ between two inhibitors, but also discerns ${\alpha}_1$ and ${\alpha}_2$ with and without substrate binding, respectively. The factors involved in the dissociation constants of inhibitors can also be evaluated by the present plot. It is also shown that the present kinetic approach can be extended to other forms of activators or hydrogen ions with some modification.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.05a
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• pp.77-78
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• 2019

인천시는 2017년 12월에 발생한 진두항 낚시어선 충돌사고 등 선박에서 발생하는 해양사고를 예방하기 위해 선박충돌경고, 해상안전정보 제공, 실시간 자동 입출항 관리, 해상 e-Call 서비스 등을 제공하는 선박안전 실증사업을 추진하고 있다. 정확화고 표준화된 서비스를 제공하기 위해 서비스에 대한 명확한 정의가 필요하며, 이러한 서비스 정의서 개발을 통해 향후 다양한 서비스 설계를 위한 기틀을 마련할 수 있다. 본 연구에서는 선박안전 실증사업 서비스 정의서를 개발하기 위해 대상이 되는 중소형선박 운항자 및 유관기관 종사자에 대한 요구사항 분석을 실시하였다. 요구사항 분석을 통해 도출된 사항을 바탕으로 서비스 정의서 개발 및 적용할 경우, 보다 정확하고 효율적인 선박안전운행 시스템이 구축 될 것으로 기대된다.

• Journal of Information Processing Systems
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• v.15 no.1
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• pp.169-180
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• 2019

Transmitting visual information over a broadcasting network is not only prone to a copyright violation but also is a forgery. Authenticating such information and protecting its authorship rights call for more advanced data encoding. To this end, electronic watermarking is often adopted to embed inscriptive signature in imaging data. Most existing watermarking methods while focusing on robustness against degradation remain lacking of measurement against security loophole in which the encrypting scheme once discovered may be recreated by an unauthorized party. This could reveal the underlying signature which may potentially be replaced or forged. This paper therefore proposes a novel digital watermarking scheme in temporal-frequency domain. Unlike other typical wavelet based watermarking, the proposed scheme employed the Lorenz chaotic map to specify embedding positions. Effectively making this is not only a formidable method to decrypt but also a stronger will against deterministic attacks. Simulation report herein highlights its strength to withstand spatial and frequent adulterations, e.g., lossy compression, filtering, zooming and noise.

• Proceedings of the Korean Society of Computer Information Conference
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• 2021.07a
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• pp.541-542
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• 2021

클라우드 컴퓨팅 환경에서는 고성능 컴퓨팅을 지원하기 위해 사용자에게 GPU(Graphic Processing Unit)가 할당된 가상머신을 제공하여 사용자가 고성능 응용을 실행할 수 있도록 지원한다. 일반적인 컴퓨팅 환경에서 한 명의 사용자가 GPU를 독점해서 사용하기 때문에 자원 경쟁으로 인한 문제가 상대적으로 적게 발생하지만 독립적인 여러 사용자가 컴퓨팅 자원을 공유하는 클라우드 환경에서는 자원 경쟁으로 인해 서로 성능 영향을 미치는 문제를 발생시킨다. 본 논문에서는 여러 개의 가상머신이 단일 GPU를 공유하는 RPC(Remote Procedure Call) 기반 GPU 가상화 환경에서 다수의 가상머신이 GPGPU(General Purpose computing on Graphics Processing Units) 작업을 수행할 때 GPU 메모리 입력 경쟁으로 인해 발생하는 커널 함수의 실행 지연 문제를 분석한다.

• Annual Conference of KIPS
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• 2024.05a
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• pp.87-88
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• 2024

최근 대규모 애플리케이션의 효율적인 운영을 위한 컨테이너 기술의 도입이 급격하게 이루어지고 있으며, 이에 따라 컨테이너 환경의 보안을 향상하기 위한 여러 기술이 제안되고 있다. 특히 악성 컨테이너의 무분별한 시스템 콜 사용을 막기 위해 Seccomp 정책을 통한 접근 제어 기술을 제공하고 있지만, 현재 컨테이너가 사용하고 있는 Seccomp의 경우 시스템 콜 정책을 업데이트하기 위해서는 컨테이너를 재배포해야 한다는 한계점을 가지고 있다. 본 논문은 이를 해결하기 위해 eBPF와 LSM을사용하여 컨테이너 종료 없이 동적으로 시스템 콜 사용을 제한할 수 있는 KubeRosy를 제안한다.