• Biotechnology and Bioprocess Engineering:BBE
• /
• 제11권3호
• /
• pp.251-257
• /
• 2006

The components of the media used to elicit the biosynthesis of $poly-{\gamma}-glutamic$ acid $({\gamma}-PGA)$ by Bacillus subtilis ZJU-7 were investigated, particularly the carbon and nitrogen sources Of the 7 carbon sources investigated, sucrose induced the highest rate of ${\gamma}-PGA$ productivity; among the nitrogen sources, tryptone had the best effect for ${\gamma}-PGA$ production. A $2^{6-2}$ fractional factorial design was used to screen factors that influence ${\gamma}-PGA$ production significantly, and a central composite design was finally adopted to formulate the optimal medium. ${\gamma}-PGA$ productivity improved approximately 2-fold when the optimal medium was used compared with the original nonoptimized medium, and volumetric productivity reached a maximum of 58.2 g/L after a 24-h cultivation period.

• Design & Manufacturing
• /
• 제10권2호
• /
• pp.39-43
• /
• 2016

Most of automobile parts manufactured through sheet metal forming are mass-produced by using press mold. In recent years, automation and speeding up of press lines have been expanding to maximize product productivity using a press die. The proportion of the moving time in the press line is high, and therefore requires high-speed and automated equipment for the moving process. In this paper, to provide the double-moving system can be the moving time reduction and increased productivity. Developed transport system consists of the material supply, the material feeding device and the PLC controller and the devices are positioned between each of the pressing process. In this paper, the double-moving system including developed units using a multi-axial single-acting through this reduced the C/T(cycle time) and improved the productivity.

• 대한안전경영과학회지
• /
• 제10권2호
• /
• pp.205-210
• /
• 2008

The research interprets the principles of sampling error design for quality statistics models such as hypothesis test, interval estimation, control charts and acceptance sampling. Introducing the proper discussions of the design of significance level according to the use of hypothesis test, then it presents two methods to interpret significance by Neyman-Pearson and Fisher. Second point of the study proposes the design of confidence level for interval estimation by Bayesian confidence set, frequentist confidential set and fiducial interval. Third, the content also indicates the design of type I error and type II error considering both productivity and customer claim for control chart. Finally, the study reflects the design of producer's risk with operating charistictics curve, screening and switch rules for the purpose of purchasing and subcontraction.

• 한국생산제조학회지
• /
• 제20권3호
• /
• pp.298-303
• /
• 2011

Recently, demand on machine tools has been increased because the machine and automobile industry is booming. Therefore, the machine tools need to have a high accuracy and productivity. To build a high precision machine tool and increase its productivity, structural analysis needs to be carried out for vibration and stiffness of the machine tool before its detail design. However, it is the fact that many manufacturers of machine tools depend on their know-how about design experience. Therefore, in this paper, the static and dynamic analysis is carried out for evaluating a horizontal CNC lathe and then, applied to its detail design. It is positive that the analysis can lead to reduction of design time and improvement of the quality of the lathe as its design proceeds.

• 대한안전경영과학회지
• /
• 제21권1호
• /
• pp.17-23
• /
• 2019

The diesel engine generate many pollutants such as PM(Particulate matter) and NOx(Nitrogen oxide). So the SCR(Selective catalytic reduction) must be required to meet the emission standard. The SCR catalyst market is growing rapidly, and the automobile markets using alternative energy sources are growing rapidly. This study deals with optimization of the calcination process the manufacturing process of SCR catalyst to be competitive. The calcination process is a bottleneck and it is required to optimize productivity and accept to be safety, But we cannot trade off anything in terms of safety. We applied DOE(Design of experiments) among many research methods performed in various fields. In order to achieve quality and productivity optimization. The dependent variables in the DOE were selected as NO Conversion(%). The independent variables were selected as the calcination temperature, soaking time and fan speed RPM. the CCD(Central composite designs) constructs response surface using the data onto experience and finds optimum levels within the fitted response surfaces. Our tests are our stability guarantee and efficient together with operation.

• 국제학술발표논문집
• /
• The 1th International Conference on Construction Engineering and Project Management
• /
• pp.1208-1211
• /
• 2005

The design phase has a great influence on the success of subsequent phases in the project which can be connected with the success of the overall project. Several studies have focused on the effective design management. However, it is too complicated and difficult to manage the design process for the reason that it has a lot of participants and design information and consists of thousands of decisions by an architect alone. Accordingly, it is the main issue for the success of the project how well the design phase be organized and managed. In recent, even in domestic, the importance of design phase has begun to be referred in the conferences. Lean Construction also has a close look at those issues and makes ready to apply specific management methods, called to Lean Design & Construction. Managers can consider a variety of uncertainties to be under control through making the overall process effectively from the early stage. By establishing the efficient process from the design phase before the construction phase, managers can result in a desirable productivity. The aim of this study is to bring the concept (Lean Design & Construction) in domestic design circumstances and verifies the possibility how to apply the concept to the design phase.

• Journal of Advanced Marine Engineering and Technology
• /
• 제37권7호
• /
• pp.784-791
• /
• 2013

Recent advanced IT made layout design fast and accurate by using algorithms. Layout design should be determined by considering the position of equipment with satisfying various space constraints and its component works with optimum performance. Especially, engine room layout design is performed with mother ship data, theoretical optimal solution, design requirements and several design constraints in initial design stage. Piping design is affected by position of equipment seriously. Piping design depends on experience of designer. And also piping designer should consider correlation of equipment and efficiency of space. In this study, space evaluation method has been used to evaluate efficiency of space. And also this study suggested object function for optimal piping route, Average Reservation Index(ARI), Estimated Piping Productivity(EPP) and with modified space evaluation method. In this study, optimum pipe routing system has been developed to reflect automated piping route with space efficiency and experience of piping designer. Engine room is applied to the design of the piping in order to confirm validity of the developed system.

• 유통과학연구
• /
• 제17권3호
• /
• pp.31-39
• /
• 2019

Purpose - This study aims to investigate and analyze the factors that affect women's work productivity based on ethnic in the food and beverage industry. Also, it is also to determine whether there are differences in the productivity of female workers based on these ethnic groups. Research design, data, and Methodology - The approach of this research is quantitative by using multiple linear regression analysis and analysis of different tests using SPSS and tested on 114 samples of female workers in various small-scale, medium-sized food and beverage industry categories and large in Makassar City, Indonesia. Determination of samples based on proportional stratified sampling. Industry sampling criteria based on some workers, assets and wealth. Results and Conclusions - The results of this study state that health, years of service, work ethic, age, wages, and work environment have a significant effect on work productivity. While the level of education, the number of dependents does not have a considerable impact, the fact that there is a difference in the productivity index of female workers in a significant sector is compared to small and medium scale enterprises, including the variables of government policies related to pension insurance, work accident insurance and health insurance.

• 대한간호학회지
• /
• 제43권1호
• /
• pp.20-29
• /
• 2013

Purpose: The purpose of this study was to propose and test a predictive model that could explain and predict nursing productivity. Methods: A survey using a structured questionnaire was conducted with 360 nurses in Korea. The data were analyzed using SPSS Windows 18.0 and AMOS 19.0 program. Results: Based on the constructed model, burnout and organizational commitment were found to have direct effects on nurses' turnover intention and nursing productivity. While nursing work environment was found to have indirect effects on nurses' turnover intention and nursing productivity. Conclusion: This structural equational model is a comprehensive theoretical model that explains the related factors and their relationship with nursing productivity. Comprehensive organizational interventions to improve nursing productivity should focus on improving the nursing work environment. Findings from this study can be used to design appropriate strategies to decrease nurse turnover in Korea. Further studies are needed to prospectively verify these causal relationships with larger samples.

• Journal of Korea Trade
• /
• 제23권3호
• /
• pp.1-19
• /
• 2019

Purpose - This research examines the effect of a foreign subsidiary on the productivity growth of a Two-way trading manufacturing firm in Korea. We explore firms engaged in both trade and FDI simultaneously to verify whether participation in GVC as a broad concept is an efficient internationalization strategy to increase the productivity of a Korean manufacturing firm. Design/methodology - Based on the firm-level data by utilizing the Survey of Business Activities from Statistics Korea, we examine the impact of vertically integrated foreign subsidiaries on the productivity of a manufacturing firm that exports and imports simultaneously. Findings - The results show that if a Two-way trading firm establishes one or more overseas subsidiaries, the total factor productivity growth increases. Moreover, the FDI effect is statistically significant when the destination country has an economically close relationship with Korea. However, these effects are disparate depending on the industrial competitiveness or market situation where the subsidiary is located. Nonetheless, the synergy effect resulting from industrial combination is represented in China and the USA only. Originality/value - As the importance of GVC has become more emphasized around the world. In spite of the scarcity of related domestic studies, we explored the effect of multinational manufacturing firms participating in GVC using firm-level data.