• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2000년도 추계학술대회 논문집
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• pp.34-40
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• 2000

통합 생산시스템의 성능평가문제는 많은 요소들이 고려되어야하며 수리모델을 위하여 많은 가정사항들이 주어진다. 실제 제생산시스템의 운영환경을 고려한 성능평가를 위하여 Simulation Model들이 많이 연구되어 오고있으나, 실제 활용의 용이성 및 관련 data 및 출력의 이해가 실무자들에게는 매우 어려운 문제로 남아 있다 본 연구에서는 사용자의 요구 수준과 System의 환경 여건에 따른 각종 Simulation Model들을 비교 조사 연구하여 수요자의 요구와 System의 특성에 적절한 방법을 활용할 수 있도록 하였다. 본 연구에 다음과 같은 Simulation Model들을 비교 연구하였다 : 1) CAN-WIP Model, 2) RAM-Cost Model, 3) FACTOR/AIM 응용, 및 4) AutoMod의 응용, 본 연구에 고려된 Simulation Model들의 관련 응용 Program을 개발하고 Sample 예제를 통하여 결과를 비교 분석하였다.

• 산업경영시스템학회지
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• 제37권4호
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• pp.63-71
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• 2014

As power consumption increases, more power utilities are required to satisfy the demand and consequently results in tremendous cost to build the utilities. Another issue in construction of power utilities to meet the peak demand is an inefficiency caused by surplus power during non-peak time. Therefore, most power company considers power demand management with time-based electricity rate policy which applies different rate over time. This paper considers an optimal machine operation problem under the time-based electricity rates. In TOC (Theory of Constraints), the production capacities of all machines are limited to one of the bottleneck machine to minimize the WIP (work in process). In the situation, other machines except the bottleneck are able to stop their operations without any throughput loss of the whole manufacturing line for saving power utility cost. To consider this problem three integer programming models are introduced. The three models include (1) line shutdown, (2) block shutdown, and (3) individual machine shutdown. We demonstrate the effectiveness of the proposed IP models through diverse experiments, by comparing with a TOC-based machine operation planning considered as a current model.

• Korean Chemical Engineering Research
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• 제49권6호
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• pp.697-703
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• 2011

축전식 탈염(CDI)은 높은 비표면적을 갖는 전극에 전기화학적 원리로 이온을 흡착하여 제거하는 기술이다. CDI 기술은 낮은 전위에서 작동하기 때문에 에너지 소비가 작고, 전극을 재생할 때 산, 염기 혹은 염을 사용하지 않기 때문에 환경친화적인 기술이다. 본 연구에서 우리는 CDI 기술의 동향을 알아보기 위해 특허와 논문을 조사했다. 데이터베이스는 WIPS와 Scopus를 사용하여 얻었으며 전극기술, 모듈기술 및 응용기술에 따라 조사되었다. CDI의 기술 동향은 연도별, 국가별, 출원인별, 기술별로 조사되었다.

• Journal of Information Processing Systems
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• 제15권1호
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• pp.181-188
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• 2019

A production system is a management system that supports all activities to perform production operations at the manufacturing site. From the point-of-view of a smart factory, smart manufacturing systems redesigned the concept of onsite production systems to fit the entire system and its necessary functional composition. In this study, we select the key functions needed to build a smart factory for a PCB line and propose a new six-step model for the deployment of a smart manufacturing system by integrating essential functions. The smart manufacturing system newly classified the production and operation tasks of PCB manufacturing and selected necessary functions through requirement analysis and benchmarking of advanced companies. The selected production operation tasks are mapped to the functions of the system and configured into seven modules, and the optimal deployment model is presented to allow flexible responses to the characteristics of the tasks. These methodologies are first presented in this study, and the proposed model was applied to the PCB line to confirm that they had significant changes in the work method, qualitative effects, and quantitative effects. Typically, lead time and WIP have reduced by about 50%.

• Asian Pacific Journal of Cancer Prevention
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• 제16권13호
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• pp.5191-5197
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• 2015

A partial response or resistance to chemotherapeutic agents is considered as a main obstacle in treatment of patients with cancer, including breast cancer. Refining taxane-based treatment procedures using adjuvant or combination treatment is a novel strategy to increase the efficiency of chemotherapy. PPM1D is a molecule activated by reactive oxygen species. whose expression is reported to modulate the recruitment of DNA repair molecules. In this study we examined the impact of arsenic trioxide on efficacy of paclitaxel-induced apoptosis in paclitaxel-resistant MCF-7 cells. We also investigated the expression of PPM1D and TP53 genes in response to this combination treatment. Resistant cells were developed from the parent MCF-7 cell line by applying increasing concentrations of paclitaxel. MTT assays were applied to determine the rate of cell survival. DAPI staining using fluorescent microscopy was employed to study apoptotic bodies. Real-time RT-PCR analysis was also applied to determine PPM1D mRNA levels. Our results revealed that combination of arsenic trioxide and paclitaxel elevates the efficacy of the latter in induction of apoptosis in MCF-7/PAC resistant cells. Applying arsenic trioxide also caused significant decreases in PPM1D mRNA levels (p<0.05). Our findings suggest that arsenic trioxide increases paclitaxel-induced apoptosis by down regulation of PPM1D expression. PPM1D dependent signaling can be considered as a novel target to improve the efficacy of chemotherapeutic agents in resistant breast cancer cells.

• 구강회복응용과학지
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• 제23권3호
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• pp.259-268
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• 2007

purpose: This study was to evaluate the shear bond strength of Lithium Disilicate Glass-Ceramic by removable method of temporary cement on the abutment tooth. Material and Method: Sixty molar teeth of human with the occlusal surface up were mounted in acrylic resin blocks. The 45 specimens were prepared to exposure dentin by diamond bur and the eugenol-containing temporary cement($Cavitec^{TM}$ ($KERR^{(R)}$, U.S.A)was applied to the dentin surfaces. After initial removal of the cement with a dental explorer, the specimens were divided into 4 groups of 15 specimens each. The dentin surfaces of the specimens were treated by rotary instrument with as follow pastes: $Zircate^{(R)}$ prophy paste(Dentsply, U.S.A), Radent Prophy Paste(Pascal company,inc. U.S.A), and Dental pumice(Wip mix corporation,U.S.A). An adhesive resin luting agent(Variolink $II^{(R)}$, Ivoclar Vivadent, Leichtenstein) including Monobond-S and $Excite^{(R)}$ was applied to all specimens. The ceramic specimens were made with an A1 ingot of IPS Empress $II^{(R)}$ (Ivoclar Vivadent, Leichtenstein). After the specimens were stored in distilled water for 48hr, the shear bond strength(MPa) was measured by a Universal testing machine(Zwick 145641, Zwick, Germany) at a 1mm/min cross-head speed. The data were statistically analyzed by one-way ANOVA and Duncan's multiple range test. Results: In all group, there were no significant differences in comparison with the control group(p>0.05). The pattern of most failure showed the mixed type of cohesive and adhesive failure. Conclusion: Resin bond strength of IPS Empress $II^{(R)}$ was not affected by removal method of the temporary cement.

• 산업공학
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• 제25권2호
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• pp.241-254
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• 2012

This paper studies the relationship between SCM(Supply Chain Management) metrics and corporate value (Tobin's Q) for manufacturing and wholesale/retail firms in Korea. Specifically, the multiple regression analysis is used to investigate the relationships 1) between inventory level, inventory turns, and days of inventory and Tobin's Q and 2) between cash-to-cash (C2C) cycle time including its components such as days of inventory, days sales outstanding, and days payable outstanding and Tobin's Q. The results indicate that there exist statistically significant negative relationships between inventory levels and days of inventory (DOI) and Tobin's Q. Also, we found that there exist commonly known negative correlations between days of raw materials inventory and days of work in process (WIP) inventory and Tobin's Q. For the C2C cycle time, we found that there -exists a statistically significant negative relationship between the C2C cycle time and Tobin's Q. Also, we found that there exist commonly known correlations between the two components of C2C cycle time and Tobin's Q such as the negative for DOI and days sales outstanding. This study clearly shows the negative relationship in general between inventory levels and corporate value and between C2C time and corporate value, and this kind of result has not been found by previous studies in Korea.

• 한국작물학회지
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• 제65권2호
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• pp.104-112
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• 2020

본 실험은 옥수수(B73)에서 습해에 대한 생육 특성 변화와 습해 관련 유전자 발현 양상을 조사하여 내습성 옥수수 마커 개발을 위한 기초자료로 활용하고자 수행되었다. 1. 침수 처리구에서 초장(21.3%), 근장(50.6%), 잎 및 뿌리의 무게(21.6%), 잎의 SPAD 값(55.7%) 및 엽록소 함량(35.3%)은 감소하였고, 뿌리의 ROS의 함량은 2시간까지 46.5% 증가하다가 6시간 후에는 차이가 발생하지 않았다. 2. 뿌리 두께가 대조구에 비해 습해 처리구에서 2.5배이상 증가하였고, 뿌리 피층에 다수의 통기조직이 형성되었다. 3. 통기조직 형성(EXP1)과 에틸렌 생합성에 관련된 유전자(EREBP105) 등 습해 관련 유전자 7개가 습해 처리구에서 2.5배 이상 발현이 증가되는 것을 Microarray 분석을 통해 선별하고 RT-PCR을 통해 확인하였다.

• 한국조경학회지
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• 제36권3호
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• pp.29-38
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• 2008

본 연구는 도시숲의 하나인 학교숲의 가치를 평가하는 것을 주요한 연구목적으로 한다. 이를 위해 진술된 선호모형인 컨조인트 모형을 활용하여 학교숲의 환경생태적, 교육적, 사회문화적, 경제적 속성을 연구하였다. 문헌연구 결과， 학교숲의 4개 속성(가치)별 수준이 선정되었고， 학교숲 관계자와 비관계자로 구분하여 279명 을 대상으로 설문조사를 실시하였다. 분석 결과, 4개 속성 중 가장 중요한 학교숲의 속성은 경제적 속성으로 나타났으며, 다음으로 환경생태적, 사회문화적, 교육적 가치 순으로 나타났다. 모형의 적합도는 0.900 이상으로 매우 유의하게 나타났다. 경제적 가치 증에서는 0원, 1,000원 의 효용값이 다른 두 수준보다 높게 선호되었고, 환경생태적 가치 중에서는 도시공기정화 가능의 값이 가장 높고, 다음으로 학교경관 조성, 동물 서식 공간 제공, 미기후조절 순으로 나타났다. 또한 지역주민의 여가활동과 관련된 사회문화적 가치 중에서는 자연관찰이 산책 및 휴식, 운동보다 효용이 더 높게 나타났으며, 교육적 가치 중에서는 환경의 중요성 인식이 가장 높았고, 정서함양, 지식습득 순으로 나타났다. 이러한 효용값을 기초로 가구당 WIP를 추정해본 결과, 전체 응답자의 경우는 3,580원, 학교숲 관계자는 3,650원, 비관계자는 3,540원으로 나타났다. 이를 근거로 연간 전체 가구의 순수 경제적 가치를 추정해보면 약 6,820 억 원이며, 학교숲 관계자의 경우 6,970억원, 비 관계자의 경우 6，750원으로 나타났다.