• 한국주조공학회지
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• 제25권6호
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• pp.259-264
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• 2005

The copper clad steel wire is used extensively as lead wires of electronic components such as capacitors, diodes and glass sealing lamp because the wire combines the strength and low thermal expansion characteristic of Fe-Ni steel with the conductivity and corrosion resistance of copper. In order to fabricate the copper clad steel wire, several processes including electro-plating, tubecladding extrusion process and dip forming process have been introduced and applied. The electroplating process for the production of copper clad steel wire shows poor productivity and induces environmental load generation such as electroplating solution. The dip forming process is suitable to mass production of copper clad steel such as trolley wire. and need expensive manufacturing facilities. The present paper describes the improvement of the conventional continuous casting process to fabricate copper clad steel wire, which its core metal is low thermal expansion Fe-Ni alloy and its sheath material is copper. In particular, the formation of intermetallic compound at interface between core and sheath was investigated in order to introduce optimum continuous casting process parameter for fabrication of copper clad steel wire with higher electrical conductivity. The mechanical strength of copper clad steel wire was also investigated through wiredrawing process with of 95% in total reduction ratio.

• 한국응용과학기술학회지
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• 제19권4호
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• pp.327-334
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• 2002

Transesterfication of vegetable oils and methanol with alkaline catalyst was carried out to produce biodiesel fuel by continuous process. The process consists of two static mixers, one tubular reactor and two coolers and gave $96{\sim}99$% of methyl ester yield from soybean oil and rapeseed oil. Experimental variables were the molar ratios of methanol to vegetable oil, alkaline catalyst contents, flow rates, mixer element number. The optimum ranges of operating variables were as follows; reaction temperature of $70^{\circ}C$, l:6 of molar ratio of methanol to oil, O.4%(w/w) sodium hydroxide based on oil, static mixer elements number of 24 and 4 min. residence time.

• 전자공학회논문지B
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• 제32B권12호
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• pp.1545-1551
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• 1995

As the modern industrial processes become more complex, it is getting more difficult to model and control the processes. Naturally, an advanced type of DCS(Distributed Control System) with higher level functions is being sought. Advanced DCS is a DCS with advanced functions such as fault diagnosis, GPC(Generalized Predictive Control), NN(Neural Network), and Fuzzy Control. In this thesis, we have studied a fuzzy control algorithm for realizing an advanced DCS. Its algorithm is implemented in a form of function code which is a process control language, being used by the industrial engineers. To verify the realized function code of the fuzzy control, the function code is applied to a continuous casting process of the Pohang Iron & Steel Works in Kwangyang. The rules of the fuzzy control were collected via interviews of the field operators and their operation documents. Finally under a real-time operating system environment, usability of the function code of the fuzzy control is shown via simulation for the continuous casting process.

• 한국안전학회지
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• 제8권4호
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• pp.127-132
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• 1993

Porphyrin-catalyzed reduction of TNT to triaminotoluene was performed in both batch reactions and a continuous process. Packed-bed reactors were used to study porphyrin-catalyzed reduction in a continuous process. A reactor was packed with DEAD(diethylaminoethyl)-substituted glass beads on which $Co^{+3}$_centered deuteroporpgyrin Ⅸ, -2, 4-disulfonic acid was immobilized, and another containing only DEAE glass beads was used as a control. The porphyrin exhibited catalytic activity in its immobilized state up to 100 hours of operation. Based on the successful abatement of nitrobodies by porphyrin-catalyzed reduction in both batch and continuous process, this process is recommended to be used as a pretreatment for biological treatment or carbon adsorption treatment of TNT wastes.

• 한국축산시설환경학회지
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• 제4권2호
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• pp.149-160
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• 1998

Hog manure slurry amended with sawdust was composted in pilot-scale reactor vessels using continuous aeration nuder different C/N ratios and pH conditions during composting high rate (decomposition) process. For each material two replicated piles were built and monitored over a period of three weeks. The compost piles had an initial volume of 0.18 ㎥. In this study we evaluated the temperature in compost O2 and CO2 evolution, aeration rate, NH3 concentration etc. and investigated the stability of compost during composting high rate process. According to measured results, while the maximum NH3 concentration during composting high rate process. According to measured results, while the maximum NH3 concentration during composting high rate was in the range of 213 to 412 ppm on 5th day which was near the optimum C/N(22∼24) and pH(7.5∼7.9). And then, the NH3 concentration reduced to between 22∼26 ppm by 13th day. The maximum NH3 concentration for the lower C/N(18∼19) and pH value of 6 reached 574∼1,063 ppm by the 16th through 11th days and the NH3 concentration during continuous aerated composting high rate process, it was more important to manage NH3 gas so that compost odor is reduced.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권1호
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• pp.6-10
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• 2001

The production of chitosan from the mycelia of Absidia coerulea was studied to improve cell growth and chitosan productivity. Culture conditions were optimized in batch cultivation (pH 4.5, agitator speed of 250 rpm, and aeration rate of 2 vvm) and the maximum chitosan concentration achieved was 2.3g/L under optimized conditions. Continuous culture was carried out successfully by the formation of new growth spots under optimized conditions, with a chitosan productivity of 0.052g/L(sup)-1 h(sup)-1, which is the highest value to date, and was obtained at a dulution rate of 0.05h(sup)-1. Cell chitosan concentrations reached about 14% in the steady state, which is similar to that achieved in batch culture. This study shows that for the continuous culture of Absidia coerulea it is vital to control the medium composition.

• 대한안전경영과학회지
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• 제16권2호
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• pp.231-236
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• 2014

In this study, the changes in collection efficiencies due to the time changes of activated carbons were ascertained, and in order to identify the magnitude of adsorption, the before-use and after-use iodine adsorption values were analyzed. In addition, as a result of examining the characteristics of continuous process and non-continuous process and as a result of investigating whether the emission standards would be maintained, the continuous process and printing facilities were seen as not being able to maintain the emission standards. Also were found, in the case of non-continuous process,-taking into consideration the special nature of the job -for 4${\o}$ palletized charcoal, a collection efficiency near 50% was shown even after 96 hours. Also, when the inlet concentration was about 300ppm, it is thought that the emission standards would be maintained if the activated carbons are replaced within at least 96 hours in the case of 4${\o}$ palletized charcoal and the use was deemed pointless in the case of carbon. The results of this study are expected to provide assistance in selecting replacement periods for activated carbons and in selecting absorbents at the project sites, and are expected to be of significant help in the selection of precipitators that can collect total hydrocarbons for compliance of the emission standards.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.403-407
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• 2005

This paper proposes a looperless tension control algorithm which is robust to disturbance and tensional variation in rolling process using SVR(Support Vector Regression). Hot rolling process which is global technology to coil steel after continuous finishing process for welded bars followed by roughing mill process, becomes hot issue. Finishing mill process not only makes it possible to produce ultra thin steel strip(0.8 mm) but enhance the quality of terminals of coil, which increases the productivity due to faster process. Constant tension control between stands in hot rolling process is essential to enhance the quality of steel. Sensorless tension control is under research by some advanced companies to replace the conventional tension control method because in continuous finishing mill process, it is impossible to install the looper used in conventional control system. Simulation results show the effectiveness of the proposed algorithm.

• KSBB Journal
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• 제23권3호
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• pp.213-218
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• 2008

일반적으로 약주 생산 공정에서 고정화 담체를 이용하는 연속식 반응기에서는 회분식 반응기와 비교하여 생성되는 알코을 생성량 못지않게 연속식 반응기에서 연속적으로 생성되고 있음을 알 수 있었다. 고정화 담체를 이용한 연속식 반응기는 약주의 품질에 긍정적인 효과를 보이는 것으로 나타났으며 담금 공정에서의 처리효과를 분석한 결과는 다음과 같다. 1) 회분식 배양에서 에탄올의 생성량은 1차 담금 1일 째부터 12%이상 증가하는 것으로 나타났으며 연속배양은 2차 담금에 효모를 주입하지 않아도 회분식 배양에서와 같은 알코올 도수를 가지면서 지속적으로 얻어졌다. 또한 pH는 4.4에서 3.8로 감소하는 패턴을 나타냈으며 산소농도는 1 ppm정도 차이가 나타났으나 이는 연속적으로 기질이 반응기로 주입되기 때문에 증가된 것이다. 2) 폴리플로필렌에 폴리스티렌을 샌드위치식으로 접합한 고정화 미생물담체는 연속배양에서 효모 주입 없이도 회분식 배양과 비교해보았을 경우에 당화과정과 알코올 생성과정 등이 서로 상반되는 패턴을 갖으면서 생물학적인 반응이 정상적으로 진행됨을 증명하였다. 3) 연속배양의 실험결론을 토대로 1차 담금에서 당의 생성기질을 이용하였을 경우, 10톤/일 생산하는 약주생산 공장은 1년간 효모 투입비용을 환산해 본 결과 1억원 이상의 투입비용이 감소하는 것으로 나타났다.

• 정보처리학회논문지D
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• 제14D권3호
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• pp.273-284
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• 2007

RFID 미들웨어 시스템은 애플리케이션의 질의를 처리하기 위해서 다수의 RFID 판독기에 의해 지속적으로 인식되는 RFID 스트리밍 데이터를 수집 및 정제한다. 이러한 질의들은 미들웨어에서 일정기간 동안 수행되기 때문에 연속 질의라고 불린다. 미들웨어의 성능을 개선하기 위해서는, 이러한 연속 질의를 효과적으로 처리하기 위한 색인이 필수적이다. 최근, 데이터가 아닌 질의를 기반으로 색인을 구축하는 질의 색인 기법들이 제안되었으며 이러한 기법들은 이동체 위치 스트리밍 데이터 혹은 센서 스트리밍 데이터에 대하여 연속 질의를 처리하는 환경에서 향상된 성능을 보여준다. EPCglobal은 RFID 애플리케이션을 위한 표준 질의 인터페이스인 Event Cycle Specification (ECSpec)을 제안하였다. ECSpec 기반의 연속 질의는 질의의 조건을 대상 도메인 공간에 표현하면 다수의 세그먼트로 표현되는 특징이 있다. 이러한 RFID 질의 색인의 데이터에 대하여 기존의 질의 색인을 사용하면 다수의 데이터를 삽입해야 하기 때문에 색인을 구축 및 유지하기 위한 비용이 커지게 된다. 이러한 문제를 해결하기 위해서, 이 논문에서는 다수의 세그먼트를 새로운 변환공간으로 표현하고 이것을 결집하여 단일 데이터로써 표현하는 결집 변환(Aggregate Transformation) 기법을 제안한다. 또한, 기존 질의 색인과 변환 기법을 적용한 색인의 성능을 비교한다.