고효율 효소를 분비하는 균주의 선발 및 신문고지의 효소탈묵 특성(제5보) - Bacillus sp.에서 단리한 Cellulase와 Xylanase의 특성 -

박성철,이양수,정인수,Park, Seong-Cheol,Lee, Yang-Soo,Jeong, In-Soo 한국펄프종이공학회 2005 펄프.종이기술 Vol.37 No.3

This study was carried out to investigate the characteristics of extracellular cellulase and xylanase from 4 selected different species, such as enzyme activity and stability by pH, temperature and metal ions, for application into enzymatic deinking system. The optimal temperature and pH for enzyme activity of Bacillus pumilus I, B. subtilis I, B. pumilus II and B. subtilis II were mainly $40{\sim}60^{\circ}C$ and pH $6.0{\sim}7.0$, respectively. Certain metal ions, calcium and cobalt, elevated enzyme activity, even though there were different results of enzyme activities based on various metal ions in 4 different species. With these results we suggest that enzymatic deinking system should be proceed at $50^{\circ}C$ with neutral pH condition.

DEA-SBM 모델과 EM 군집 분석에 근거한 자동차 공급사슬 효율성 평가 및 벤치마킹 방안

박성철,이장희 한국기업경영학회 2016 기업경영연구 Vol.23 No.1

The objective of this paper is to present the model for evaluating the supply chain efficiency and benchmarking process of the component suppliers in Korean automotive industry. The proposed method is theoretically based on the combination of the slacks based super efficiency model (DEA-SBM) and the expectation maximization (EM) algorithm clustering analysis. DEA-SBM is one of many data envelopment analysis (DEA) with input and output criteria to evaluate the relative efficiency in order to rank the decision making unit (DMU). EM algorithm makes cluster based on probability considering the maximization of log-likelihood. This method can be differentiated from previous approaches in the literature. This study uses time series data from 2012 to 2014 of 64 tier-one Korean domestic automotive chassis parts suppliers and adopts the DEA-SBM model in order to increase the analysis's accuracy and EM clustering to classify the suppliers by the actual input resources. It also suggests the practical stepwise benchmarking paths to the inefficient firms. In this study, three input factors are selected: number of employees, assets and cost of goods sold (COGS). The output factors include two financial and three non-financial data: sales, operating profit and three kinds of customer’s evaluation scores about suppliers, i.e quality, delivery and technology. Firstly, we conduct the EM clustering to classify the suppliers depending on three input factors, resulting in seven clusters. We analyze the cluster changes of each supplier over time so as to monitor the cause of changes. Then, we calculate the super-efficiency scores of the suppliers using DEA-Solver Pro 9.0 software. We also conduct the analysis about the changes of efficiency scores over time. From this analysis, we apparently recognize which suppliers get better or worse over three years. For the sake of the comprehensive evaluation, we use a hybrid approach, i.e. the efficiency analysis based on the EM cluster as well as on the industrial sectors. Since the value chain is totally different depending on the industrial sectors. The industrial sector is also a key perspective like EM cluster. The best efficient EM cluster was cluster 7 and the worst was cluster 4. On the other hand, the best efficient industrial sector was assembly sector and the worst was fastener sector. From the results of the analysis, we can find out the most inefficient cluster and industrial sectors which need to improve efficiency to increase the overall supply chain performance. In the case study, we selected the fastener sector as the improvement targets. We suggested the stepwise improvement paths. One stage is the efficiency improvement within the same EM cluster, which anticipated fast benchmarking and improvement due to the similarity of the firms' scales. Other stage is the improvement between different EM clusters. To obtain the final improvement targets, we adopt the DEA projection analysis within the selected industrial sector. We illustrate the benchmarking paths as the case of DMU #7 belonging to the fastener sector and EM cluster 5. As we have seen in the case study, this study provides the inefficient firms with a stepwise benchmark approach considering industrial sectors with final improvement target in terms of input and output factors to reach the highest level of efficiency frontier in the same industrial sector. With this proposed method, the buyer, specifically a car manufacturer, can precisely evaluate their suppliers, strategically select the improvement targets, practically determine improving direction and suggest effective benchmarking paths to suppliers. 본 연구는 자동차 산업 1차 협력사를 대상으로 DEA-SBM 모델과 EM 군집분석을 활용하여 자동차 공급 사슬의 효율성 분석을 실시하였다. 협력사가 속한 EM 군집의 변동과 효율성의 변동에 대해 시계열 분석을 하였으며, EM 군집 및 업종을 고려한 효율성 분석을 통하여 개선이 필요한 집단을 선별하였다. 효율이 낮은 기업이 효과적으로 개선을 진행할 수 있도록 단계별 벤치마킹 경로를 제시하고 전략적 개선 방향과 함께 최종 개선 목표값을 제시하였다. 기존 선행 연구에서는 협력사가 속한 업종 및 규모에 대한 통합적 고려 없이 전체 협력사를 대상으로 산출된 효율성 점수만으로 개선 대상을 선정하였고, 전체 공급사슬의 경쟁력을 향상하기 위해 개선이 필요한 저 효율 기업에 대해 구체적인 개선 경로 및 방안을 제시하지 못 하였다. 자동차 샤시 부품 군에 속하는 64개 협력사의 3년간 재무 자료와 고객사 평가 점수를 투입변수와 산출변수로 사용하여 실증 연구를 실시한 결과, 규모와 업종에 따른 개선 대상 집단을 효과적으로 선별할 수 있었으며, 단계별 개선 경로를 도식화하여 개선의 방향성에 대해서 명확히 제시할 수 있었다. 협력사의 특성을 통합적으로 고려한 평가 방법과 단계별 구체적인 개선 방안을 제시한 점에서 기존 연구와 차별화되며, 자동차 산업 공급사슬 관리에 실효성 있는 모형으로 공헌할 것으로 판단된다.

포스터 전시 발표 순서 : 소화기 ; 커피 관장으로 유발된 직장대장염 1예 (초)

박성철,금보라,김은선,정은석,장진수,이세동,권용대,박상훈,서연석,김용식,진윤태,전훈재,엄순호,김창덕,류호상 대한내과학회 2008 대한내과학회지 Vol.75 No.1S

Overexpression of Arabidopsis YUCCA6 enhances environment stress tolerance and inhibits storage root formation in sweetpotato

박성철,김호수,이형은,김윤희,곽상수 한국식물생명공학회 2019 Plant biotechnology reports Vol.13 No.4

Auxin is a major plant hormone that regulates many developmental processes in plants. Arabidopsis thaliana YUCCA6 (AtYUCCA6) mediates the tryptophan-dependent auxin biosynthesis pathway in A. thaliana. To study the effect of auxin in sweetpotato [Ipomoea batatas (L.) Lam], we generated transgenic sweetpotato plants expressing AtYUCCA6 under the control of the oxidative stress-inducible SWPA2 promoter (referred to as SY plants). SY plants displayed high-auxin phenotypic traits such as narrow downward-curled leaves, increased height, and increased node numbers. SY plants showed increased tolerance to 5 μM of methyl viologen-mediated oxidative stress by maintaining a lower ion leakage than wild-type (WT) plants. Moreover, SY plants exhibited higher relative water contents and lower malondialdehyde contents than WT plants under drought stress. Young SY plants also showed inhibition of adventitious root growth. SY plants showed significantly lower storage root formation than WT plants. Our results indicate that AtYUCCA6-mediated auxin overproduction is associated with tolerance to oxidative and drought stress. It also suggests that negatively regulates the formation of storage roots in sweetpotato.

토크컨버터의 극저온 시동성 향상에 관한 연구

박성철,김준혁 한국자동차공학회 2018 한국자동차공학회 지부 학술대회 논문집 Vol.2018 No.11

반어적 의미의 구성방식과 그 성격에 대하여

박성철 한국텍스트언어학회 2000 텍스트언어학 Vol.8 No.-

토크컨버터의 터빈 발란스 노이즈 개선에 관한 연구

박성철 한국자동차공학회 2020 한국자동차공학회 학술대회 및 전시회 Vol.2020 No.11

Bacterial toxin (세균성독소) 에 대한 문헌적 고찰

박성철 김천대학교 2016 김천대학교 논문집 Vol.13 No.-

감염증의 성립과정은 감영과 발병으로 나누어 고찰 할 수 있다.

공립단설유치원 신설 소요경비 산정

박성철,박희원,Park, Sung-Chul,Park, Hee-Won 한국교육녹색환경연구원 2014 교육·녹색환경연구 Vol.13 No.1

The purpose of this study is to propose different construction costs based on the number of kindergarten classrooms. Literature review reorganized the space program for kindergartens. For suggesting the room sizes of each spaces, this paper collected the three types of analysis; 1) the previous researches, 2) field survey, and 3) construction drawings. Based on the results, building sizes for the individual class sizes were presented. And, this paper made a standard priced BOQ(Bill of Quantity) through analysis on the existing priced BOQ. Finally, the recommendable construction costs were proposed by applying the building sizes to the standard priced BOQ. The practitioners of school districts and government organizations can make appropriate budgets considering the building sizes.

Integrated process design of Al6061 alloy bolts for fastening offshore platforms

박성철,이동훈,고대철,김병민,김명환,이경훈 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.8

In this study, we design an integrated manufacturing process for Al6061 alloy bolts to fasten offshore platforms. The proposed scheme includes the theoretical design and numerical study for the heading, trimming, and thread-rolling process. For the theoretical design, the initial rod diameter and the penetration depth (PD) in the thread-rolling process are calculated according to thread standards and geometric relation. The dimensions of the initial workpiece for the heading process are obtained using the volume constancy law. Considering process limitations to predict the defects, the number of stages is set, and the preform is then determined using the design rule in the heading process. Based on the theoretical design, finite-element (FE)-analysis is conducted. In order to predict the defects and fracture phenomena, the ductile fracture criterion was applied during the heading and trimming processes. The Taguchi method is used to optimize the trimming and thread-rolling process with the set of design parameters, such as the PD, transfer velocity, and revolutions per minute in the thread-rolling process, and the blade radius (BR), land width, and stop distance in the trimming process, respectively. Results show that the PD and BR have the most significant effect on the dimensional accuracy and forming load. To validate the proposed design, the aluminum alloy bolt-forming experiment is performed. We obtain the sound Al6061 alloy M12 hexagonal bolt shaped with highdimensional accuracy. Therefore, this research provides valuable guidelines for the design of the integrated forming process in actual bolt production.