• 한국자동차공학회논문집
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• 제8권5호
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• pp.67-77
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• 2000

Investigated was the effect of propene(C3H6) on the NO-NO2 conversion in dry exhaust gases from lean burn engine using a pulsed corona discharge. A kinetic model was developed to characterize the plasma chemistry in simulated exhausts containing propene. The model uses ELENDIF program to solve Boltzmann equation for electron energy distribution function, and CHEMKIN-II program to solve stiff ODE(ordinary differential equation) problems for species concentrations. The corona discharge energy per pulse and the time-space averaged E/N were obtained by fitting the model to experimental data. The model calculation shows good agreement for NO and NO2 concentrations with the experimental data, and predicts the formation of byproducts such as CH2O, CH3HCO, CO AND CH3NO2 Propene enhances the NOx conversion enormously at lower energy density and the NOx conversion increases with the increase of initial propene and oxygen concentration, and temperature.

• 한국자동차공학회논문집
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• 제19권3호
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• pp.23-28
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• 2011

To secure basic data for intake port design, effects of a port masking on the part load performance were investigated in a 4 valve SI engine. For this purpose, 9 kinds of masking, which have different shapes and masking ratio, are applied to the engine intake system. The characteristics of the performance were estimated through mixture response test at various engine load and speed. The results show that NOx emission, one of indexes for stratification, increases considerably in spite of retarded spark timing due to the stratification which is caused by unequal flow distribution between the two intake ports. The mechanism of stratification by masking is different from axial stratification and the fuel entering through masked port plays a very important role in this stratification process. In conclusion, the port masking method could be easily applied to engine intake system and be very effective for inducing the stratified charging without the change of port design.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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• pp.49-50
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• 2016

Recently in Korea, some studies on concrete that mass quantity of additives are substituted in order to respond to the government's Low Carbon Green Growth Policy are being conducted. As on of additives, FA as an industrial by-product is used in a large quantity. However, In some of the domestic FA refineries, since some quantity of concrete without passing through the refining process is released for sales for the reasons of the shortening of production time and the cost reduction, etc., it exerts a bad influence on the quality of concrete. Therefore, in this study, there was implemented an experiment on the effects of using an extreme quality of FA which is available for distributing domestically on the engineering characteristics of lean mortar. As a result, it was found that the quality of FA exerts its effect on the compression strength bigger than the flow property or the air volume.

• Journal of Information Science Theory and Practice
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• 제9권1호
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• pp.54-67
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• 2021

This paper presents the ISRI (Information Systems Research Indicators) Web tool, publicly and freely available at isri.sciencesphere.org. Targeting Information Systems (IS) researchers, it compiles and organizes IS adoption and use theories/models, constructs, and indicators (measuring variables) available in the scientific literature. Aiming to support the IS theory development process, the purpose of ISRI is to gather and systematize information on research indicators to help researchers and practitioners' work. The tool currently covers eleven theories/models: DeLone and McLean's IS Success Model (D&M ISS); Diffusion of Innovations Theory (DOI); Motivational Model (MM); Social Cognitive Theory (SCT); Task-Technology Fit (TTF); Technology Acceptance Model (TAM); Technology-Organization-Environment Framework (TOE); Theory of Planned Behavior (TPB); Decomposed Theory of Planned Behavior (DTPB); Theory of Reasoned Action (TRA); and Unified Theory of Acceptance and Use of Technology (UTAUT). It also includes currently over 400 constructs, nearly 2,500 indicators, and about 60 application contexts related to the models. For the creation of the tool's database, nearly 580 references were used.

• Nuclear Engineering and Technology
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• 제55권12호
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• pp.4695-4702
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• 2023

Nuclear power plants play a pivotal role in the global energy infrastructure, fulfilling a substantial share of the world's energy requirements in a sustainable way. The management of these facilities, especially the handling of spent nuclear fuel (SNF), necessitates meticulous inspections to guarantee operational safety and efficiency. However, the prevailing inspection methodologies lean heavily on human operators, which presents challenges due to the potential hazards of the SNF environment. This study introduces the design of a novel Pre-Batched Inspection Strategy (PBIS) that integrates robotic automation and image processing techniques to bolster the inspection process. This methodology deploys robotics to undertake tasks that could be perilous or time-intensive for humans, while image processing techniques are used for precise identification of SNF targets and regulating the robotic system. The implementation of PBIS holds considerable promise in minimizing inspection time and enhancing worker safety. This paper elaborates on the structure, capabilities, and application of PBIS, underlining its potential implications for the future of nuclear energy inspections.

• Asian-Australasian Journal of Animal Sciences
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• 제22권8호
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• pp.1069-1077
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• 2009

Castration of male pig produces significant negative effects on skeletal muscle development. The androgen receptor (AR), two splice variants of insulin-like growth factor-I (IGF-I Ea and MGF) and the myostatin gene may play important roles in this process. In the present study, the expression of AR, IGF-I Ea, MGF and myostatin genes in three skeletal muscles, the brachialis, longissimus and semitendinosus, were studied using real-time quantitative RT-PCR. Our experimental design used 14 pairs of male Landrace sire${\times}$Yorkshire dam piglets. The two piglets in each pair were full sibs, one of which was castrated at 21 d of age; the other remained intact. The study group was divided into subgroups of equal size. Animals in the first subgroup were slaughtered at 147 d and those of the second at 210 d of age. Carcass weight and lean meat yield were similar between boars and barrows at 147 d of age (p>0.05), whereas barrows had lower carcass weight and less lean meat yield at 210 d of age (p<0.05). Castration caused down-regulation of AR gene expression at both 147 and 210 d of age (p<0.05). The two splice variants of the IGF-I gene from porcine skeletal muscle were cloned using RT-PCR, and it was found that MGF differs from IGF-I Ea in having a 52-base insert in the last coding exon of the mRNA. Both splice variants were down-regulated by castration only at 210 d of age (p<0.05). No differences in expression of the myostatin gene were observed between boars and barrows at either 147 or 210 d of age (p>0.05). These results suggest that the downregulation of AR, IGF-I Ea and MGF gene expression following castration helps to explain the negative effect of castration on skeletal muscle development.

• Asian-Australasian Journal of Animal Sciences
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• 제31권10호
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• pp.1670-1676
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• 2018

Objective: This study was conducted to enable on-line prediction of primal and commercial cut weights in Korean slaughter pigs by AutoFom III, which non-invasively scans pig carcasses early after slaughter using ultrasonic sensors. Methods: A total of 162 Landrace, Yorkshire, and Duroc (LYD) pigs and 154 LYD pigs representing the yearly Korean slaughter distribution were included in the calibration and validation dataset, respectively. Partial least squares (PLS) models were developed for prediction of the weight of deboned shoulder blade, shoulder picnic, belly, loin, and ham. In addition, AutoFom III's ability to predict the weight of the commercial cuts of spare rib, jowl, false lean, back rib, diaphragm, and tenderloin was investigated. Each cut was manually prepared by local butchers and then recorded. Results: The cross-validated prediction accuracy ($R^2cv$) of the calibration models for deboned shoulder blade, shoulder picnic, loin, belly, and ham ranged from 0.77 to 0.86. The $R^2cv$ for tenderloin, spare rib, diaphragm, false lean, jowl, and back rib ranged from 0.34 to 0.62. Because the $R^2cv$ of the latter commercial cuts were less than 0.65, AutoFom III was less accurate for the prediction of those cuts. The root mean squares error of cross validation calibration (RMSECV) model was comparable to the root mean squares error of prediction (RMSEP), although the RMSECV was numerically higher than RMSEP for the deboned shoulder blade and belly. Conclusion: AutoFom III predicts the weight of deboned shoulder blade, shoulder picnic, loin, belly, and ham with high accuracy, and is a suitable process analytical tool for sorting pork primals in Korea. However, AutoFom III's prediction of smaller commercial Korean cuts is less accurate, which may be attributed to the lack of anatomical reference points and the lack of a good correlation between the scanned area of the carcass and those traits.

• 산업경영시스템학회지
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• 제39권4호
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• pp.106-116
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• 2016

MTO (Make to Order) is a manufacturing process in which manufacturing starts only after a customer's order is received. Manufacturing after receiving customer's orders means to start a pull-type supply chain operation because manufacturing is performed when demand is confirmed, i.e. being pulled by demand (The opposite business model is to manufacture products for stock MTS (Make to Stock), which is push-type production). There are also BTO (Build to Order) and ATO (Assemble To Order) in which assembly starts according to demand. Lean manufacturing by MTO is very efficient system. Nevertheless, the process industry, generally, which has a high fixed cost burden due to large-scale investment is suitable for mass production of small pieces or 'mass customization' defined recently. The process industry produces large quantities at one time because of the lack of manufacturing flexibility due to long time for model change or job change, and high loss during line-down (shutdown). As a result, it has a lot of inventory and costs are increased. In order to reduce the cost due to the characteristics of the process industry, which has a high fixed cost per hour, it operates a stock production system in which it is made and sold regardless of the order of the customer. Therefore, in a business environment where the external environment changes greatly, the inventory is not sold and it becomes obsolete. As a result, the company's costs increase, profits fall, and it make more difficult to survive in the competition. Based on the customer's order, we have built a new method for order system to meet the characteristics of the process industry by producing it as a high-profitable model. The design elements are designed by deriving the functions to satisfy the Y by collecting the internal and external VOC (voice of customer), and the design elements are verified through the conversion function. And the Y is satisfied through the pilot test verified and supplemented. By operating this make to order system, we have reduced bad inventories, lowered costs, and improved lead time in terms of delivery competitiveness. Make to order system in the process industry is effective for the display glass industry, for example, B and C groups which are non-flagship models, have confirmed that the line is down when there is no order, and A group which is flagship model, have confirmed stock production when there is no order.

• 한국산학경영학회:학술대회논문집
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• 한국산학경영학회 2005년도 추계학술발표대회 발표논문집
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• pp.29-46
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• 2005

최근에 국내에서 TPS(Toyota Production System)에 대해 기업이나 제조업 관련 사람들에게 많은 관심을 불러일으키고 있다. TPS는 일본형 생산시스템의 대표적 모델이며, 21세기 후반 생산기술 분야에 많은 기여를 하고 있으며 그 성과 역시 높은 평가를 세계 여러 기업으로부터 받고 있다. 본 연구에서는 TPS의 기본 개념과 특성 그리고 적용 절차 등 TPS의 현재 모습을 통해 기존의 TPS가 안고 있는 문제점과 한계를 조명하고자한다. 이를 통해 현재의 TPS를 앞으로도 지속적으로 적용하고 경쟁력 있는 시스템으로 발전시키기 위한 방안으로 NEW JIT 기법을 활용하고자한다. NEW JIT는 고객제일의 품질관리를 목표로 판매, 개발 그리고 생산의 각 부분의 업무프로세스를 혁신하는 것이다. 하드웨어 시스템으로는 TMS, TDS, TPS로 구성되며, 소프트웨어 시스템은 과학적 SQC(TQM-S)를 이용한 TQM의 전개로 이루어진다. 따라서 앞으로 차세대 제조관리기술을 위해 NEW JIT 기법을 보다 더 우리의 기업환경에 적합하도록 활용할 수 있는지를 검토하고 연구 발전시켜야 한다.

• 한국건설관리학회논문집
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• 제8권1호
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• pp.124-131
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• 2007

공정관리는 일정 계획에 따라 공사의 진도를 관리하는 것뿐만 아니라 프로젝트를 주어진 공기 내에 완성하기 위하여 시공 방법 및 계획을 마련하고 이에 따른 장비, 자재, 인원 등에 대한 계획을 수립하는 것을 포함한다. 본 연구는 실제 고속도로 건설공사 중 포장공정의 계획 수립에 있어서 린 콘크리트 포장작업과 콘크리트 슬래브 포장작업을 대상으로 시뮬레이션 모델을 개발하고 이를 이용하여 공정계획을 수립하는 방안을 제시하고 있다. 또한, 시뮬레이션 모델을 이용하여 수립된 계획과 해당 현장의 기존 포장공정 계획을 비교함으로서 비용과 공기 측면에서 보다 생산적이고 효율적인 대안의 수립에 시뮬레이션 기법이 효과적인 방법론이 될 수 있음을 보여 준다. 결국, 본 연구를 통해 건설공사의 시공 계획을 수립하는 초기단계에서 시뮬레이션 모델을 구축하여 체계적이고 과학적인 분석을 수행하게 되면 보다 효율적이고 생산적인 건설공정 계획 및 관리가 가능하다는 사실을 확인하고 있다.