• KSBB Journal
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• 제5권3호
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• pp.279-291
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• 1990

Partial hydrolysed and deacetylated chitin, CHITA and CHITB as supports of immobilized enzyme were obtained by treatment of acid and base respectively. Glutaraldehyde, bifunctional reagent, was employed for crosslinking between $\beta$-glucosidase and support. Immobilized enzyme activities of CHITA-Gase and CHITB-Gase were determined with the reaction of p-nitrophenol-$\beta$-D-glucopyranoside(PNG) in batch reactor, CSTR and PFR. Their optimum temperature, pH and enzymatic characteristics including Km and Vmax values were observed with variation of the flow rates. Mass transfer coefficient(h), effectiveness factor(η), deactivation rate(kd ) of two immobilized enzymes were also examined to compare efficiency of reactors.

• Proceedings of the Korean Information Science Society Conference
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• 한국정보과학회 2012년도 한국컴퓨터종합학술대회논문집 Vol.39 No.1(A)
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• pp.262-264
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• 2012

유비쿼터스 지능형 공간에서 사용자의 개입 없이도 자율 실행하는 서비스 플러그 앤 플레이 시스템(Service Plug and Play System)은 기능적인 모델로서 총체적인 시스템의 협력 프로토콜 부재로 그 동시성 및 병렬성을 반영한 실행관리를 하기 어렵다. 이는 시스템을 구성하는 모듈로, 컨텍스트 수집기, 서비스 실행기, 공간관리기, 모바일 제어기 등이 UML의 시퀀스 다이어그램으로 모델링하여 각 기기의 기능과 실행흐름을 독립적으로 표현할 뿐, 기기간의 상호작용, 특히 병렬 및 동시 실행 알고리즘을 설계하고 검증하는 절차의 부재 때문이다. 본 논문에서, 각 기기의 실행 흐름 및 상호작용을 Petri Net을 이용하여 모델링함으로써, 시스템을 구성하는 각 디바이스의 상호작용 및 실행 흐름을 정의 하고 검증한다.

• Proceedings of the Korea Information Processing Society Conference
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• 한국정보처리학회 2011년도 춘계학술발표대회
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• pp.1466-1469
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• 2011

플러그인 프레임워크는 기존 M&S 프레임워크에서의 문제점인 구성요소 간 높은 종속관계 및 낮은 유연성을 해결하고자 개발된 프레임워크 설계 방식으로, 프레임워크를 구성하는 컴포넌트를 플러그인으로 제공하여 구성요소의 추가 및 변경이 동적으로 이루어질 수 있게 한다. 또한 플러그인 컴포넌트간 통신을 위한 메시지 구조 정의가 실행 시점에 동적으로 결정되어, 컴포넌트 간 상호 독립적인 인터페이스를 보장해준다. 하지만, 플러그인 컴포넌트들의 조합이 이뤄진 상태에서 전체적인 메시지 연결 흐름이 원활하기 위해서는 각 컴포넌트에서 개별적으로 작성된 인터페이스에 대한 검증이 사전에 이뤄줘야 한다. 이에 본 논문에서는 XML 기반으로 작성된 객체 모델 명세서에 대한 무결성과 중복성을 검증할 수 있는 객체 모델 명세서 검증 도구에 대해 제안하고 이에 대한 설계내용을 설명하도록 한다.

• Journal of the Korea Society for Simulation
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• 제18권4호
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• pp.81-94
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• 2009

Research of reusability and variability design for embedded system development is insufficient. An embedded system should be designed to support new devices. If extensibility of embedded system is not considered, it is difficult to reconstruct. Currently, the development productivity and reusability of embedded system are very poor, and this will be cased about problems of increasing maintenance and development cost, and decreasing system quality such as software crisis. In this paper, we present framework of embedded system that address those problems of embedded system. We suggest a plug-in technique, based on reusability framework, which can support various devices dynamically. Also, we propose a dynamic Meta model which is base on plug-in technique.

• Applied Chemistry for Engineering
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• 제8권5호
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• pp.816-821
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• 1997

The hydrodynamics and the liquid flow characteristics were investigated in an internal circulation airlift reactor with a single nozzle as a gas distributor. In an air-water system, the gas holdup in the individual flow zone and the impulse-response curve of tracer were measured at various gas velocities and reactor heights. Experimental results showed that for the higher gas velocity(>about 8 cm/s), the flow behavior of bubbles in the riser was turbulent flow due to strong bubble coalescences and the axial height of dispersion zone of large bubbles having uniform sizes in the downcomer was decreased with increasing gas velocity. And mean gas holdups in the individual flow zone and the reactor were increased with increasing gas velocities and were decreased with increasing heights of the top section of the reactor and it was decreased with increasing the height of the top section and gas velocity. Flow characteristics of liquid in the riser and the downcomer was tend to access to plug flow and the overall flow behavior of liquid was mainly varied with the size of the top section which it was assumed to be perfect mixing zone. In these conditions, liquid circulation velocities were increased with increasing gas velocities and they were higher than those by using other gas distributors.

• Journal of Environmental Science International
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• 제2권4호
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• pp.311-316
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• 1993

Methane production from grain dust was studied using a 3 L laboratory-scale anaerobic plug flow digester. The digester was operated at; temperature of 35, 45, and 55$^{\circ}C$; hydraulic retention time(HRT) of 6 and 12 days; and influent concentration($S_o$) of 7.8 and 9.0 % total solids(%TS). With ten different operation conditions, this study showed the significant effects of temperature, hydraulic retention time, and influent concentration on methane production. The highest methane-production rate achieved was 1.903 (L methane) /(L digester)(day) at 55$^{\circ}C$, 6 days HRT, and $S_0$ of 7.8 %TS. A total of 3.767 L of biogas per day with a methane content of 50.57 % was obtained from this condition. The ultimate methane yield($B_0$) was found to be a function of temperature and influent concentration, and was described as : $B_0$ = 0.02907T-0.1263-0.00297(T-10)(%TS), where TS is the total solids in the liquid effluent, and T is temperature($^{\circ}C$). Our results showed that thermophilic condition is better than mesophilic for grain dust stabilization in an anaerobic plug flow digester.

• Transactions of the Korean Society of Mechanical Engineers
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• 제18권6호
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• pp.1551-1558
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• 1994

An experiment was conducted to investigate whether an equation of heat transfer coefficient derived form energy equation of two-phase plug flow can be actually applied to the industrial field. The heat is constantly transfered to the sand beds from the wall of heat exchanger while the sand moves down through cylindrical heat exchanger by gravity from feed hooper. To increase heat transfer, turbulators such as glass ball and steel pipe packings were used. In addition, the experiment in the case of fluidizing the sand beds was also carried out. The temperatures of the sand beds and the wall were measured along the heat exchanger axis. The density and porosity of the sand beds were also measured. The deviations of the mean velocity of sands from the velocity on the wall surface because of the slip conditions on the wall were negligible (within 3%). The heat transfer coefficients when the turbulators were used and when the sand beds were fluidized were found to be much greater than those of the plain plug flow.

• Journal of Korean Society of Environmental Engineers
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• 제37권12호
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• pp.689-695
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• 2015

A biofilm filtration for the removal of gaseous pollutants has been recognized as a process with a complex interaction between the gas flow characteristics and the process operating variables. This study aims to develop an one dimensional dynamic numerical model which can be utilized as a tool for the analysis of biofilm filtration process operated in plug flow mode. Since, in a plug flow system, minor environmental changes in a gaseous unit process cause a drastic change in reaction and the interaction between the pollutants is an influencing factor, plug flow system was generalized in developing the model. For facilitation of the model development, dispersion was simplified based on the principles of material balance. Several reactions such as competition, escalation, and control between the pollutants were included in the model. The applicability of the developed model was evaluated by taking the calibration and verification steps on the experimental data performed for the removal of BTX at both low and high flow concentration. The model demonstrated a correlation coefficient ($R^2$) greater than 0.79 under all the experimental conditions except for the case of toluene at high flow condition, which suggested that this model could be used for the generalized gaseous biofilm plug flow filtration system. In addition, this model could be a useful tool in analyzing the design parameters and evaluating process efficiency of the experiments with substantial amount of complexity and diversity.

• Korean Architects
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• 통권568호
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• pp.120-125
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• 2016

오랜만에 지난 작업들을 뒤돌아 볼 기회가 생겼습니다. 누구에게나 인생의 큰 흐름에 영향을 미치는 사건이 일어나기 마련인데요, 저의 경우는 지난 근 십년간 함께 해온 파라메트릭 디자인을 접하게 된 일이 그러한 사건들 중 하나였다고 생각이 됩니다. 그런 의미에서 트레이싱지 위에 로트링펜으로 선을 처음 그었던 그 강렬했던 기억 이후로 건축 설계를 해오면서 가장 기억에 남는 한 사건을 꼽으려고 한다면 단연히 Cornell 건축 대학원 재학 당시 처음 접하게 되었던 GenerativeComponents 수업을 이야기 하고 싶습니다. 연재를 시작하면서 잠시 언급한 바가 있었던 것 같은데요, 파라메트릭 디자인이라는 미지의 영역을 알게 해준 것이 바로 Bentley 사에서 만든 GenerativeComponents 라는 파라메트릭 디자인 툴 입니다. Microstation은 Autocad와 함께 건축설계 시장에서 많은 사용자층을 확보 하였던 캐드 툴 중 하나 이었으며 자체적으로 BIM 및 파라메트릭 툴을 위한 패키지가 Rhino의 Grasshopper의 출현 이전부터 존재하여 왔을 정도로 발전된 자동화 설계 플랫폼이었습니다. 현재도 특정 건축사사무소들이 Microstation을 꾸준히 사용하고 있으며 특히 Infra structure, plant나 civil engineering 등의 건축 외 설계 분야에서는 여전히 폭넓은 사용자층을 확보하고 있습니다. 하지만 건축 시장에서는 Rhino를 바탕으로 하는 플러그인 패키지 및 Autodesk의 건축설계 통합 패키지 등에 밀려서 사용자층이 얇아진 편입니다.

• Proceedings of the Korea Information Processing Society Conference
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• 한국정보처리학회 2015년도 추계학술발표대회
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• pp.658-660
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• 2015

W3C가 발표한 차세대 웹 표준 HTML5의 등장으로 자바스크립트의 기능이 대폭 향상 되었다. 별도의 플러그인 설치 없이 자바스크립트만으로 미디어 재생, 3D 그래픽 처리, 웹 소켓 통신 등을 제공함으로서 Active X와 같은 비표준 기술을 대체할 만큼 강력한 기능을 제공하고 있다. 이러한 흐름에 맞추어 HTML5 기능의 핵심이 되는 자바스크립트를 악용한 위험성을 인지하고 이와 관련된 연구도 활발히 이루어지고 있다. 하지만, 현재의 악성 스크립트를 탐지하는 기술은 대부분 시그니처를 기반으로 하는 패턴 매치이기 때문에 난독화 된 악성 스크립트를 탐지하기에는 많은 한계가 있다. 따라서 본 논문에서는 이런 한계를 극복하기 위해 호스트레벨에서 난독화 된 악성 스크립트를 탐지 및 실행을 방지할 수 있는 난독화 된 악성 스크립트 대응 기술을 제안한다.