불확실 인자를 고려한 회분식 공정 설계

이의수 동국대학교 산업기술연구원 1995 산업기술논문집 Vol.6 No.-

회분식 공정은 생산공정 조건들의 변경이 용이한 특징을 가지고 있으므로, 다품종 소량생산에 적합한 생산공정이다. 그러나 회분식 공정에 의한 생산 시에는 다수의 변수가 존재하고, 이들의 변동폭이 큼으로 인하여 이의 흡수를 위한 중간저장조의 역할이 중요하게 된다. 즉 중간저장조는 공정간의 간섭을 배제시키고 공정변수 값의 변동에 따른 영향을 흡수하여 줌으로써 불연속공정의 운용효율의 증대를 꾀하게 된다. 본 논문에서는 공정의 불확실 인자를 고려한 다품종생산 회분식 공정의 설계에 관하여 논하였다. 또한 중간저장조를 대상으로 규격에 벗어나는 제품의 생산이나 장치의 파손 등과 같은 장기적인 공정이상들을 흡수하기 위한 공정의 가변성 분석을 실시하고 이를 근거로 한 동적공정운용 방안을 제시하였다. 본 논문에서 다루어진 분석방법 및 제안들은 유연한 생산공정의 개발, 최적 재고관리 등에 응용될 수 있으며 조립라인 등과 같은 불연속 공정에서의 공정 유용성 분석 등에도 적용될 것으로 기대한다. Noncontinuous processes are typically used because of the flexibility they provide in accommodating a large number of moderate volume products. But these processes are susceptible to high levels of processing variability and intermediate storage has an important role in improving operating efficiency by decoupling the periodic operation of adjacent batch unites and thus, mitigating these process variabilities. This paper reviews a conceptual formulations for solving the multiproduct batch design problem under uncertainty. It also presents a model to examine the role of intermediate storage in mitigating processing uncertainties, such as batch failures and equipment failures. Investigations on the variability analysis of intermediate storage in batch process are performed and operational strategies to absorb these uncertainties are proposed. These analysis and propositions can provide a tool not only for development of flexible manufacturing system and optimal inventory management but availability studies in various noncontinuous process industries such as automatic transfer lines.

Air Stripping에 의한 트리할로메탄의 제거

임종주,이의수 동국대학교 산업기술환경대학원 1996 산업기술논총 Vol.3 No.-

The removal of trihalomethanes (THM) by air stripping was examined. Experimental variables studied for air stripping were air flow rate, initial THM concentration, and residence time. In batch aeration experiments, CHCl_3 rejection level was found to increase with an increase in air flow rate., residence time and temperature. In continuous aeration experiments, both rejection levels of CHCl_3 and CHBr_3 increased with an increase in air flow rate. For the maximum air flow rate used (air-to-water ratio=20), about 75% or the initial CHCl_3 was removed by aeration whereas only about 40% of the initial CHBr_3 was removed under the same experimental conditions. When doubling the residence time in each experiment, rejection levels of CHCl_3 and CHBr_3 were shown to be increased by a factor of 1.8 and 1.2 respectively. The CHCl_3 removal level was affected by its intial concentration and the effect was found to become more significant as higher air-to-water ratios were used during aeration. On the other hand, CHBr_3 removal was not greatly affected by the initial CHBr_3 concentration. Preliminary experimental results suggested that aeration could be an effective method for the removal of the more volatile THM component, CHCl_3 but some other method such as carbon adsorption must be accompanied in order to obtain a substantial removal of the less volatile THM component, CHBr_3.

PET 표면의 TiO_(2) 도포에 의한 친수화 연구

오성상,윤세훈,이의수 東國大學敎 産業技術硏究院 2005 산업기술논문집 Vol.15 No.1

산화 금속의 얇은 막을 졸-겔 방법으로 폴리에스터 필름 상에 도포하여 표면의 친수성을 물접촉 각으로 측정하였다. 폴리에스터 필름의 표면 친수성은 이산화티타늄의 광촉매 활성에 의해 증진되었다. 바인더로 사용되는 젤라틴, 라텍스와 같은 친수성 고분자는 수분을 받아들여 친수화를 이루기에 장점을 지닌 반면, 폴리에스터 표면과의 부착력 강화에는 단점을 가지고 있다. 실란은 무기물 입자를 폴리에스터 표면에 부착시키기 위한 바인더로 사용되었으며 바인더로서의 기능을 어느 정도 보여주었다. 결과적으로 바인더의 선택이 폴리에스터와 이산화금속의 부착에 중요한 역할을 함을 알 수 있었다. Water contact angle of the polyester film coated by thin metal oxide, which was prepared via the sol-gel method, was measured to evaluate the surface hydrophilicity. Surface hydriphilicity of the polyester film was enhanced due to the photocatalytic activity of the titanium dioxide. Concerning to hydrophilic polymers like gelatin and latex, those chemicals were positive in moisture capture, but in negative in adhesiveness. Silane was used as a binder of the inorganic particles to the polyester film and was shown to be not poor. Other binders - e.g., gelatin, polyurethane primer(alkyd resin type), and etc. - are useful to bridge (or hybrid) polyester with metal oxide. Enhancement of the hydrophilic characteristics of the surface treated polymer substrate was shown in positive in this experiment. As a result, the binder property might be of importance in hybriding polyester with metal oxide.

AgClBr Microcrystal의 결정성장과 Morphology에 관한 연구

송현,권동주,이의수,이명천,임종주 동국대학교 산업기술연구원 2001 산업기술논문집 Vol.12 No.2

감광성 유제(AgClBr)의 제조에 있어 가장 중요한 변수인 할로겐화은염 결정의 크기 및 결정형태 변화를 물리숙성 온도, 반응물의 투입속도, 젤라틴 농도, 할로겐 이온(Cl^-, Br^-)의 농도비등을 변수로 하여 관찰하였다. 실험결과 물리숙성 온도가 증가함에 따라 형성된 AgClBr 결정의 크기는 증가하지만, 반면에 질산은과 할로겐화염의 주입속도의 증가는 AgClBr 결정의 크기가 감소하는 경향을 나타냈다. 또한 젤라틴의 농도 증가는 이온상태로 존재하는 반응물의 이동을 억제하여 결정을 성장하는데 요구되는 회합속도를 저하시켜 결과적으로 생성되는 결정의 크기가 감소하였다. AgClBr의 결정형태는 Cl^-과 Br^- 이온의 농도비에 따라 가장 민감한 변화를 나타냈으며, Br의 농도비가 증가함에 따라 AgClBr 결정은 cubic형에서 round 형태로 변화하는 경향이 관찰되었다. The preparation and the morphology of silver chlorobromide crystals were studied by double-jet method. The crystal size and morphology of silver chlorobromide have been estimated by SEM photos. The influence of physical ripening temperature, rate of addition of reactants, concentration of gelatin and molar ratio of two hailde ions on the crystal growth and change of crystal morphology of obtained silver chlorobromide microparticles were investigated. The crystal size of silver chlorobromide were grown in propotion to increasing of ripening temperature, however the increasing of rate of addition of reactants induced decreasing of crystal size. The crystal morphology of photosensitive silver chlorobromide varied from cubic to round type by the increasing of concentration of bromide ion.

Hypothetical daily operation model of fuel cycle in tritium plant

Lee, Suh-Young,Chang, Min Ho,Yun, Sei-Hun,Ha, Jin-Kuk,Lee, In-Beum,Lee, Euy Soo Elsevier 2018 Fusion engineering and design Vol.130 No.-

<P><B>Abstract</B></P> <P>This paper describes a design model for the fuel cycle of a tritium plant; the model considers both the fueling line and the Neutral Beam Injector line. The fuel cycle typically consists of a 16-h of burn-and-dwell operations followed by an 8-h silent shift, so the behavioral changes of fuel cycle of the tritium plant are influenced by both an hourly cycle of burn-and-dwell operations and 24-h cycle. To provide a tool to optimize the tritium inventory level, and to gain insight into the behavior changes of the fuel cycle, a mathematical model is developed. The model mainly focuses on the Isotope Separation System, which holds the largest amount of gaseous and liquid tritium. The optimization problem is formulated as a mixed integer linear program model with linear constraints. An inductive operation scenario is presented to illustrate the applicability of the proposed model. The obtained minimum tritium working inventory in ISS is 103.498 g in the inductive operation scenario.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We introduced a mathematical model for the fuel cycle modeling of the tritium plant to minimize the tritium level. </LI> <LI> We obtain the tritium working inventory level in the Isotope Separation System during 31 repeating burn and dwell cycles. </LI> <LI> The model gives insights on both the burn and dwell hourly trends and daily trends of the tritium inventory level in the fuel cycle. </LI> </UL> </P>

Optimal Production Sequence and Processing Schedules of Multiproduct Batch Processes for Heat Integration and Minimum Equipment Costs

Lee, Euy Soo,Lee, Bom Sock,Kim, Jeong Chan 한국화학공학회 2001 Korean Journal of Chemical Engineering Vol.18 No.5

A Study on the Kinetics of Coal Tar Pitch Ageing at Elevated Temperature

Lee, Euy Soo 東國大學校 1994 東國論叢 Vol.33 No.-

여러 저장조건에서 콜탈핏치의 물성변화특성에 관한 연구를 위하여, 질소 분위기하에서 저장온도 및 시간에 따른 핏치의 연화점 및 기타 관련물성의 변화를 측정하였다. 그결과 두가지의 별개의 반응공정이 함께 작용하여 핏치물성변화의 특징을 나타냄을 밝혔다. 즉 산소가 없는 조건에서 핏치 고유의 물성변화는 두번째 반응영역에서 나타나며, 이때의 물성변화속도와 저장온도와의 상관관계는 다른문헌에 제시된 결과와도 잘 일치함을 알 수 있었다. 핏치가 공기(산소)와 접촉할때의 물성변화에 관한 연구도 함께 실시되었다. 이때 핏치에 의한 산소 소모속도와 산소농도와의 관계식을 구하였다. 또한 산소의 농도 및 핏치의 비표면적이 물성변화에 미치는 영향을 밝힘으로써, 핏치 저장조 시스템의 설계 및 운전시 고려하여야 할 중요한 인자의 정량적분석이 가능케 되었다. The aging behavior of coal tar pitch measured under a nitrogen atmosphere at various temperatures was monitored by determining time-dependent changes in SP and other properties. It was found that two separate kinetic processes are superimposed to generate the ageing behavior of pitch. The observed rates in the second kinetic regime represented the intrinsic aging behavior of pitches in the absence of oxygen. Correlation between the rate and temperature exhibits a good consistency with other literature data. The ageing behavior of pitches in contact with air was also investigated. A quantitative correlation between the oxygen consumption rate and the A quantitative correlation between the oxygen consumption rate and the concentration of the oxygen was also obtained. In the oxygen induced pitch ageing kinetics, oxygen potential and specific surface which can be defined by the mode of operation and the system design was very important to set up the pitch storage system.

VE1 Antibody Is Not Highly Specific for the <i>BRAF</i> V600E Mutation in Thyroid Cytology Categories With the Exception of Malignant Cases

Lee, Sang-Ryung,Yim, Hyunee,Han, Jae Ho,Lee, Kyi Beom,Lee, Jeonghun,Soh, Euy Young,Kim, Dae Jung,Chung, Yoon-Sok,Jeong, Seon-Yong,Sheen, Seung Soo,Park, So Hyun,Kim, Jang-Hee American Society for Clinical Pathology 2015 American journal of clinical pathology Vol.143 No.3

<P><B>Objectives:</B></P><P>We evaluated the utility of the VE1 antibody that can detect a mutant protein resulting from the <I>BRAF</I> V600E mutation as a diagnostic tool for thyroid fine-needle aspiration cytology (FNAC).</P><P><B>Methods:</B></P><P>We performed VE1 immunocytochemistry on 202 FNAC specimens from surgically confirmed thyroid nodules. The results were compared with the molecular analyses of the <I>BRAF</I> mutation in these specimens matched with their corresponding histology.</P><P><B>Results:</B></P><P>Diagnoses of FNAC specimens included benign (9.4%), atypia of undetermined significance/follicular lesion of undetermined significance (11.4%), follicular neoplasm/suspicious for follicular neoplasm (2.0%), suspicious for malignancy (9.4%), and malignancy (65.8%). VE1 immunostaining was positive in 71.3% of FNAC specimens. The overall sensitivity of the VE1 antibody was 88.8%, specificity was 71.2%, positive predictive value was 88.2%, negative predictive value was 72.4%, and diagnostic accuracy was 83.7%.</P><P><B>Conclusions:</B></P><P>VE1 immunocytochemistry in thyroid FNAC as a screening test for <I>BRAF</I> mutations is highly specific for malignant category cases but can be suboptimal due to its high false-positive rate for the nonmalignant cases.</P>

DYNAMIC OPERATING POLICIES FOR PERIODIC PROCESSES SUBJECT OT EQUIPMENT FAILURES

Lee, Euy Soo 한국화학공학회 1995 Korean Journal of Chemical Engineering Vol.12 No.3

The role of storage in buffering a process train from the effects of periodically reoccuring equipment failure is studied. The effects of deterministic and stochastic variations in the failure frequency and recovery time on the required size of intermediate storage are investigated. A dynamic operating policy is proposed to accommodate process variations in concern with the use of intermediate storage. Dynamic operation offers an increase in the average production rate of the process while using only modest levels of intermediate storage.

Fuel Inventory of the Multi-Bed Storage System of the SDS Considering Daily Operation of the Tokamak

Lee, Jae-Uk,Chang, Min Ho,Yun, Sei-Hun,Ha, Jin-Kuk,Lee, Euy Soo,Lee, In-Beum AMERICAN NUCLEAR SOCIETY, INC. 2017 FUSION SCIENCE AND TECHNOLOGY Vol.71 No.3