• 한국막학회:학술대회논문집
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• 한국막학회 2003년도 The 4th Korea-Italy Workshop
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• pp.21-24
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• 2003

Methane steam reforming (MSR) was studied in a membrane reactor (MR) with a Pd-based and a porous alumina membranes. MRs showed methane conversion higher than that foresaw by the thermodynamic equilibrium for a traditional reactor (TR). Silica membranes prepared at KRICT were characterized with permeation tests on single gases ($N_2$, $H_2$ and $CH_4$). These silica membranes can be also used for high temperature applications such as $H_2$ separation $CO_2$ hydrogenation for methanol production is another reaction where $H_2O$ selective removal can be performed with these silica membranes.

• Journal of information and communication convergence engineering
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• 제13권2호
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• pp.113-122
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• 2015

Feature subset selection is as a pre-processing step in learning algorithms. In this paper, we propose an efficient algorithm, ModifiedFAST, for feature subset selection. This algorithm is suitable for text datasets, and uses the concept of information gain to remove irrelevant and redundant features. A new optimal value of the threshold for symmetric uncertainty, used to identify relevant features, is found. The thresholds used by previous feature selection algorithms such as FAST, Relief, and CFS were not optimal. It has been proven that the threshold value greatly affects the percentage of selected features and the classification accuracy. A new performance unified metric that combines accuracy and the number of features selected has been proposed and applied in the proposed algorithm. It was experimentally shown that the percentage of selected features obtained by the proposed algorithm was lower than that obtained using existing algorithms in most of the datasets. The effectiveness of our algorithm on the optimal threshold was statistically validated with other algorithms.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2022년도 추계학술발표대회
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• pp.866-868
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• 2022

비대면 문화가 확대됨에 따라 다양한 산업의 서비스가 메타버스와 접목되어 사람들에게 제공되고 있다. 사회적 고립 등의 문제로 상담에 대한 필요성이 높아지고 있음에 주목하여 Unity를 사용해 비대면 상담이 가능한 메타버스 플랫폼을 개발하였다. 본 논문에서는 자연스러운 아바타의 움직임, 카메라의 이동, Firebase와의 데이터 전달과 Photon 동기화 기능들을 가지는 3D 월드맵의 구현에 필요한 기술들을 포함하였다. 기존에 대면으로 진행되는 상담 서비스를 대체하여 심리 상담에 대한 진입 장벽을 낮추고 접근성을 높이고자 하며, 해당 플랫폼은 여러 비즈니스들과 결합할 수 있음에도 그 의의가 있다고 본다.

• Korean Membrane Journal
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• 제8권1호
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• pp.58-66
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• 2006

The ${\beta}-glucosidase$ from olive fruit is of particular interest compared to the ones from other sources because it has shown to have high specifity to convert the oleuropein into dialdehydes, which have antibacterial activity and are of high interest for their application in the food and pharmaceutical fields. The enzyme is not yet commercially available and advanced clean and safe technologies for its purification able to maintain the functional stability are foreseen. The purification of this protein from fruit extracts has been already tempted by electrophoresis but either enzyme deactivation or high background with unclear profiles occurred. In this work, fruit extracts obtained from the ripening stage that showed the highest enzyme activity have been processed by diafiltration and ultrafiltration. Asymmetric membranes made of polyamide or polysulphone having 50 and 30 kDa molecular weight cut-off, respectively, were tested for the diafiltration process. Ultrafiltration membranes made of polyethersulfone with 4 kDa molecular weight cut-off were used to concentrate the dia-filtered permeate solutions. The efficiency of the separation processes was evaluated byenzyme activity tests using the hydrolysis of p-D-nitrophenyl-${\beta}$-D-glucopyranoside (pNPGlc) as reaction model. Qualitative and quantitative electrophoresis were applied to analyze the composition of protein solution before and after the membrane separation; in addition dot blot and western blot analyses were applied to verify the presence of ${\beta}-glucosidase$ in the processed fractions. The overall results showed that the ${\beta}-glucosidase$ functional stability was preserved during the membrane operations and the removal of 20 kDa proteins allowed to increase the specific activity of the enzyme of about 52% compared to the one present in the initial fruit extract.

• Asian-Australasian Journal of Animal Sciences
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• 제33권4호
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• pp.588-596
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• 2020

Objective: The objective of this study was to investigate the effects of low doses of organic trace minerals (iron, copper, manganese, and zinc) on productive performance, egg quality, yolk and tissue mineral retention, and fecal mineral excretion of laying hens during the late laying period. Methods: A total of 405 healthy hens (HY-Line White, 50-week-old) were randomly divided into 3 treatments, with 9 replicates per treatment and 15 birds per replicate. The dietary treatments included feeding a basal diet + inorganic trace minerals at commercial levels (CON), a basal diet + inorganic trace minerals at 1/3 commercial levels (ITM), and a basal diet + proteinated trace minerals at 1/3 commercial levels (TRT). The trial lasted for 56 days. Results: Compared to CON, ITM decreased (p<0.05) egg production, daily egg mass, albumen height, eggshell strength, yolk Fe concentration, serum alkaline phosphatase activity and total protein, and increased (p<0.05) egg loss and feed to egg ratio. Whereas with productive performance, egg quality, yolk mineral retention, and serum indices there were no differences (p>0.05) between CON and TRT. The concentrations of Fe and Mn in the tissue and tibia were changed notably in ITM relative to CON and TRT. Both ITM and TRT reduced (p<0.05) fecal mineral excretion compared to CON. Conclusion: These results indicate that dietary supplementation of low-dose organic trace minerals reduced fecal mineral excretion without negatively impacting hen performance and egg quality.

• Smart Structures and Systems
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• 제6권2호
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• pp.167-182
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• 2010

An adaptronic strut for machine tools with parallel kinematics for compensation of the influence of geometric errors is introduced. Implemented within the strut is a piezoelectric sensor-actuator unit separated in function. In the first part of this contribution, the functional principle of the strut is presented. For use of one piezoelectric transducer as both, sensor and actuator as so-called self-sensing actuator, the acquisition of the sensing signal while actuating simultaneously using electrical bridge circuits as well as filter properties are examined. In the second part the control concept developed for the adaptronic strut is presented. A co-simulation model of the strut for simulating the controlled multi-body behavior of the strut is set-up. The control design for the strut as a stand-alone system is tested under various external loads. Finally, the strut is implemented into a model of the complete machine tool and the influence of the controlled strut onto the behavior of the machine tool is examined.

• Membrane and Water Treatment
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• 제5권3호
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• pp.197-205
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• 2014

For the first time in Bangladesh, a bench scale membrane bioreactor (MBR) unit was tested in treating a textile wastewater in the industry premises of EOS Textile Mills LTD, Dhaka for three months. The performance of the unit was compared with that of the conventional activated sludge treatment plant, which is in operation in the same premises. The COD and BOD removal efficiency of the MBR unit reached to around 90% and 80% respectively in 20 days whereas the removal efficiency of the conventional treatment plant was as low as 40-50% and 38-40% respectively. The outlet COD and the BOD level for the MBR unit remained stable in spite of the fluctuation in the feed value, while the conventional effluent treatment plant (ETP) failed to keep any stabilized level. The performance of the MBR unit was much superior to that of the functional ETP and the water treated by the MBR system can meet disposal standard.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2017년도 학술발표회
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• pp.323-323
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• 2017

본 연구 대상인 주암댐-주암조절지댐간 도수터널은 저수지 간 연계운영을 통하여 서 남해안 일대의 용수 공급하기 위하여 건설되어 운영되었으나, 터널의 구조적 불안정성이 제기됨에 따라 향후 발생 가능성이 있는 용수공급 중단을 방지하기 위하여 신규 도수터널이 제안되었다. 계획된 신규 도수 터널의 주요 시설물은 크게 양방향 운영이 가능한 터널(D=3.3 m, L=11.23 km), 각 저수지 상황별 운영을 위한 취수문비 2개소, 도수가 이루어지는 상황에서 수문 돌발 폐쇄시 수충격을 감쇄하기 위한 배기구(air vents) 2개소가 계획되었다. 이에 따라 본 연구에서는 주암댐에서 주암조절지댐으로 최대 유량이 통수되는 상태에서, 수문폐쇄에 따른 수충격을 정량적으로 분석하고자 Joukowsky 공식에 적용하여 완폐쇄와 급폐쇄시 도수터널의 안정성을 검토하였으며, 수문 폐쇄로 인한 천이적인 흐름상태 등 수충격 모의가 가능한 1차원 ITM 모형을 적용하여, 수리분석과 수치모형과 결과 비교하고, 계획된 배기구의 유무에 따른 효과를 알아보고자 하였다. 분석 결과, 계획된 0.3 m/min으로 수문을 폐쇄할 경우, 도수터널의 안정성에는 문제가 없을 것으로 분석되었으나, 수문을 급 폐쇄 할 경우, 압력수두가 크게 증가하여 도수터널에 위험이 있을 것으로 분석되었으며 배기구 유무에 따른 수충격 검토 결과 도수터널 내의 수압상승을 적절히 조절하는 조압수조의 역할을 만족스럽게 수행할 것으로 분석되었다.

• Architectural research
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• 제25권1호
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• pp.11-17
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• 2023

This study aims to derive key construction supervision work that can be digitalized among construction supervision work. The scope of the study includes domestic construction sites to which the Building Act of South Korea is applied. First, the construction supervision process was identified through extensive consultation of construction expert witnesses. Afterwards, the key construction supervision works for digitization were derived through survey results construction expert witnesses. Among the 24 supervision works throughout the pre-construction, construction, and post-construction stages, the proportion of supervision work manpower or cost, the type of data generated by supervision work and the urgency of introducing digital technology, and the impact on productivity and safety of supervision work were evaluated on a 5-point scale from "very low" to "very high" was investigated. The survey was conducted by t-test analysis, and as a result, it was possible to derive that the level of digitization was higher than average in "quality management," "safety management," and "collection and cooperation of maintenance instructions." It can be interpreted that digitization has been introduced on a pilot testing basis or has already been completed according to the needs of the site. On the other hand, it can be interpreted that the work that are obtained below the average score are considered to be realistically constrained at the construction site and that it is inevitable for the supervisor to proceed manually. Future studies include analyzing the quantitative impact of the key construction supervision work once digitalization is fully applied.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2020년도 제62차 하계학술대회논문집 28권2호
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• pp.657-659
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• 2020

공동주택 전기 요금제에는 호별 계약, 단일계약 및 종합계약으로 분류된다. 호별계약은 저압전력이 공급되는 공동 주택에 적용되며, 세대별 사용량에는 주택용 저압요금제가 적용되고 공동부 전기 사용량에는 일반용 저압 또는 주택용 저압 요금제가 적용된다. 단일계약과 종합계약은 고압전력이 공급되는 공동주택에 적용된다. 단일계약은 공동주택 세대별 사용량과 공용설비 전기 사용량을 합산하고 평균하여, 평균세대의 전기요금량을 기준으로 주택용 고압 요금을 적용하여 공동주택 전기 요금을 산정하는 방식이다. 종합계약은 공용설비 전기 사용량에는 일반용 고압요금을 적용하지만, 세대별 전기 사용량에 대해서는 주택용 저압 요금을 적용하여 공동주택 전기 요금을 산정하는 방식이다. 공동주택에서는 3가지 요금제중 하나를 선택하여 한국전력과 계약을 맺을 수 있다. 고압전기를 공급받는 공동주택은 상황에 따라 단일계약이 유리한 경우도 있고, 종합계약이 유리한 경우도 있다. 따라서 본 연구에서는 공동주택에서 전기요금을 시뮬레이션하여 각 공동 주택에 적절한 요금제를 선택하는 의사결정을 지원할 수 있는 공동주택 전기요금 시뮬레이터를 설계하고 개발하고자 한다. 이를 위해 본 연구에서는 공동주택 전기요금 시뮬레이터의 요구사항을 분석하고, 시뮬레이터를 설계하고, 공동주택 전기요금 시뮬레이터 프로토타입을 개발하였다.