• Proceedings of the Optical Society of Korea Conference
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• 2002.07a
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• pp.158-159
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• 2002

오늘날에도 RSA암호문은 현대 암호에 대부분 적용될 정도로 안전하다고 생각되어왔다. 또한 PGP(Pretty Good Privacy)라는 가장 대중적인 암호화 소프트웨어도 RSA 원리를 기반으로 하고 있다. 그러나 RSA암호화체계는 주요한 결점이 있다. 인수분해하는 것이 ＂어렵다＂라고 하지만, 결코 증명되지 않았고, 또한 인수분해를 수행하는 아주 빠른 알고리즘의 존재가 전혀 불가능하지는 않기 때문이다. 따라서 현존하는 암호화 체계보다 더 확실한 안전을 보장해주는 새로운 암호화 체계와 암호화키의 분배시스템의 필요성이 대두되고 있다. (중략)

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.136-137
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• 2011

선박평형수내 미생물 처리를 위해 다양한 방법들이 사용되고 있으며, 본 논문에서는 랩테스트를 위한 전기분해장치로서 전기분해 방식에 사용되는 정류기 개발 및 그 장치에 관한 것이다. 선박평형수를 처리하기 위해 설계된 시스템은 랩테스트용 도로 적용이 가능하다.

• Proceedings of the KAIS Fall Conference
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• 2002.05a
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• pp.222-225
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• 2002

소프트웨어 설계 프로세스는 일반적으로 두 가지 활동을 통해 수행되는 데, 한 가지는 소프트웨어 시스템을 적절한 크기의 기능모듈로 분해해 나가는 것이며, 다른 한가지는 분해된 모듈을 구조적 패턴 위에 매핑 하는 것이다 본 논문의 관점은 분해된 기능모듈을 매핑 하는 구조적 패턴을 개발하는 데 있으며, 이러한 패턴들이 체계화하여 기능모듈을 구조화하는 작업을 보다 효율적으로 추진하여 높은 품질의 소프트웨어를 효율적으로 개발할 수 있도록 하고자 한다.

• Clean Technology
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• v.15 no.2
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• pp.116-121
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• 2009

In this paper, we investigated the effect of an indirect oxidation zone in an electrolysis reactor that used Ti/$IrO_2$ as the anode and SUS 316L as the cathode. Based on our preliminary results, the electrolysis reactor was operated with pole plate interval of 6 mm, current density 1.0 $A/dm^2L$ and electrolyte concentration 15%. The removal efficiency, COD (chemical oxygen demand), was additionally increased by 55% and 12.5${\sim}$15.0% in the direct and indirect oxidation zones, respectively. The removal efficiencies of T-N (total nitrogen) and T-P (total phosphorus) were found to be 88% and 75%, respectively. It was shown that the additional effect of the indirect oxidation zone on the removal was nearly negligible. Also, as the removal of COD,T-N and T-P took place during the initial2${\sim}$5 days of reaction, it was concluded that there was no need to extend the retention time of the electrolysis reactor.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2000.04a
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• pp.19-144
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• 2000

막대한 에너지원을 갖고 있는 고분자 폐기물은 열분해에 의하여 오일화가 가능하며 이 오일은 대체 연료유로서 사용이 가능하다. 그러나 이 연료유를 생산하기 위해서는 폐플라스틱 및 폐타이어의 경우는 공정을 서로 달리하여야 이용이 가능하며 생성유의 유질에서도 다소 차이가 있다. 올레핀계가 함유된 폐플라스틱을 열분해 오일화 하기 위해서는 분해 촉매를 사용하여야 하며 열분해유는 경유분과 d사한 성상을 갖고 있으며 폐타이어의 열분해유는 유황성분 및 BTX 분을 상당량 함유하고 있어서 경유분과는 다소 다른 성상을 갖고 있다. 또한 폐타이어 및 폐플라스틱의 열분해 기술이 사용화되기 위해서는 열분해시 발생하는 Coking 문제 극복 및 시스템에 대한 설계기술이 뒷받침되어야 한다.

• Journal of the Korean Society of Propulsion Engineers
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• v.8 no.4
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• pp.102-108
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• 2004

A layout of regenerative liquid rocket engine using turbo pump has been designed for development of high performance liquid rocket engine. each components of engine system was placed by considering assembly and characteristic. first stage engine system is controled by one plane of axis gimballing and composed of four engine assembly to cluster with launch vehicle. second stage engine system is controled by two plane of axis gimballing and composed of one engine assembly. assembly and disassembly Processes and required program have been developed. various shape of instruments were also developed for carrying out assembly and disassembly process efficiently.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.2
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• pp.191-197
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• 2006

This paper deals with a fault detection system design for nuclear steam generator water level control system. We expressed the nonlinear properties of the steam generator level system as a T-S fuzzy system with time varying uncertain parameters. We design a residual generator using a left coprime factorization of the T-S fuzzy model and a fault detection filter in order to improve the fault detection performance. We demonstrate the efficiency of the suggested design method via many computer simulations.

• Applied Chemistry for Engineering
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• v.24 no.1
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• pp.87-92
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• 2013

Nonthermal plasma hybridized with photocatalysts is proven to be an effective tool to degrade toxic organics in wastewater. In this study, a specially designed dielectric barrier discharge (DBD) plasma system combined with photocatalysts was applied to decompose pestiticides such as dichlorovos, carbofuran and methidathon, which are frequently used in the golf courses and the orange plantations. The degradations of the pesticides in single and coupled systems were evaluated. The single system was used with ozone plasma which consisted of electrons, radicals, ions produced by oxygen gas and air, with and without ultra-violet (UV) irradiation, respectively. The coupled systems utilized the air-derived ozone plasma combined with zinc oxide, titanium dioxide and graphite oxide photocatalyst activated by UV. The graphite oxide was synthesized by a modified Hummer's method and characterized using FTIR spectrometer. It was elucidated that the plasma reaction with graphite oxide (0.01 g/L) brought about almost 100% of degradation degrees for dichlorovos and carbofuran in 60 min, as compared with the performances showed by no catalyst condition. The photocatalyst-hybridized plasma in the presence of UV irradiation was proven to be an effective alternative for degrading pesticides.

• Journal of Korean Institute of Industrial Engineers
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• v.13 no.2
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• pp.47-57
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• 1987

The main purpose of this paper is to design a simple interactive software system for planning activities, called APS. We discuss the importance of informal and formal specifications of the system design, and survey a number of promissing design methodologies. To design APS, we present a methodology based upon the hierarchical decomposition of the system, and illustrate the methodology as applied to the design of an activity planning system.

• Applied Chemistry for Engineering
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• v.10 no.3
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• pp.349-353
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• 1999

A study was carried out to see the effects of phenol on the biological degradation of a wastewater containing 2,4-dichlorophenol and 2,4-dinitrophenol and the biodegradation kinetic coefficients of Eckenfelder's modified model for the activated sludge process. The system containing base mix (BM) which was formulated with essential energy sources and nutrients was run down and washed out when 2,4-dichlorophenol and 2,4-dinitrophenol was introduced into the base mix unit without acclimation to phenol. Whereas for the system acclimated to phenol, the treatment efficiency was 91.9% in terms of $BOD_5$ and treatability for each chemical of phenol, 2,4-dichlorophenol, and 2,4-dinitrophenol was 99.8%, 43.3% and 62.5% based on concentration, respectively. Additional BM was added into the combined unit containing phenol, 2,4-dichlorophenol, 2,4-dinitrophenol so that the better treatment efficiency was achieved for each compound. The biokinetic coefficient of Eckenfelder's modified model without phenol acclimation was not estimated because the system did not reach the steady state. Thc coefficient for the phenol acclimation was 12.44 /day, however it was changed as 46.91 /day in addition of both of phenol acclimation and 47 mg/l of BM. The results presented above could be useful for the process design and further study in the field of biodegradation of benzene derivatives.