• Journal of Welding and Joining
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• v.14 no.4
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• pp.79-88
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• 1996

For improvement in productivity and weld quality, weld seam tracking and welding parameter control are very essential in the welding of a structure which can not be cxactly fit-up due to mismatch, discontinous gap, deflection, etc.. In this study, an automatic weld seam tracking system is developed for I-butt joint structure, and the system consists of XYZ working table, vision sensor and user interface program. In the developed vision sensor system, an image projection algorithm for weld-line detection and an adaptive current control algorithm for gap variation were implemented. The user interface program developed in this study by basing on the objct oriented concept could provide very convenient way to utilize the tracking system with the pull-down menu driven structure. The developed system showed a good seam tracking and weld quality control capability corresponding to deflected weld lines and gap variations.

• Journal of Korean Institute of Industrial Engineers
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• v.36 no.3
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• pp.186-192
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• 2010

The present study classified the auto-parts makers into four groups according to their investment ownership. Four groups consist the one fully owned by Koreans, the one fully owned by foreigners, the one owned less than 100% but more than 50% by foreigners, lastly the one owned by less than or equal to 50% by foreigners. Among these, the auto-parts makers, 100% foreign ownership, have the highest Malmquist productivity index while 100% Korean-owned part-makers has the lowest productivity. In case of the 100% foreign ownership companies, the cause of Malmquist change, however, is attributed to the technical efficiency change. In particular, the pure technical change is the main source of the Malmquist change. This may indicate that the 100% foreign-owned companies have successfully transferred their production process technologies to the Korean plants. They are enjoying so called the "imitation-effect." 100% Korean-owned companies were not able to create the "imitationeffect" and therefore failed to close the gap with the foreign-owned companies in terms of the production efficiency. 100% Korean-owned auto-parts makers, however, outperformed the foreign-owned companies in the technological change. The outstanding technological change may indicate that Korean-owned part makers were able to narrow the gap with the foreign-owned companies in the area of engineering technological capabilities. The same results were also observed for 50% foreign-owned companies. Knowing that the core competence of the auto-parts makers lies on the engineering technological capabilities, the research found that the most desirable form of the foreign investment was 50% of foreign ownership.

• International Area Studies Review
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• v.20 no.1
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• pp.147-165
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• 2016

We empirically examine the validity of second generation endogenous growth theory suing 21 OECD countries' panel data(1981~2011). Due to non-stationarity in all variables, we test the cointegrated relationships strongly supporting the semi-endogenous growth model. In the estimation of total factor productivity growth function, the growth of domestic and foreign R&D investment levels statistically significantly affect total factor productivity growth. R&D intensity, however, has significant impacts on the total factor productivity growth only in a few models, and international technology gap also has positive impacts on GDP growth. Thus the semi-endogenous growth model is relatively supported while fully endogenous growth model is weakly and occasionally supported in OECD countries. The policy implication of supporting the semi-endogenous growth model is that the sustaining growth requires increasing R&D expenditures.

• International Area Studies Review
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• v.16 no.3
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• pp.119-134
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• 2012

This paper examines the shift to service economy in the developed countries including Korea and analyzes whether Baumol's cost disease hypothesis could explain the labor productivity growth in the developed countries even though the share of service industry is rising rapidly. We have found the following results: First, the shift to service economy is widely observed in the developed countries. Second, the productivity gap between manufacturing and service industry is widening as a result of stagnant productivity growth in service industry. Third, however, the productivity in the whole economy is still growing because of the large productivity differences among the sub-industries in service industry. Fourth, we have found that the productivities of some service industries, such as finance, communication, business service, etc., are almost same or larger than the productivity of manufacturing industry. From this fact it is likely that the productivity of the whole economy could grow in spite of the stagnant productivity growth in service industry.

• Membrane and Water Treatment
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• v.13 no.1
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• pp.51-62
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• 2022

Vacuum-assisted air gap membrane distillation (V-AGMD) has the potential to achieve higher flux and productivity than conventional air gap membrane distillation (AGMD). Nevertheless, there is not much information on technical aspects of V-AGMD operation. Accordingly, this study aims to analyze the effect of membrane deformation on flux in V-AGMD operation. Experiments were carried out using a bench-scale V-AGMD system. Statistical models were applied to understand the flux behaviors. Statistical models based on MLR, GNN, and MLFNN techniques were developed to describe the experimental data. Results showed that the flux increased by up to 4 times with the application of vacuum in V-AGMD compared with conventional AGMD. The flux in both AGMD and V-AGMD is affected by the difference between the air gap pressure and the saturation pressure of water vapor, but their dependences were different. In V-AGMD, the membranes were found to be deformed due to the vacuum pressure because they were not fully supported by the spacer. As a result, the deformation reduced the effective air gap width. Nevertheless, the rejection and LEP were not changed even if the deformation occurred. The flux behaviors in V-AGMD were successfully interpreted by the GNN and MLFNN models. According to the model calculations, the relative impact of the membrane deformation ranges from 10.3% to 16.1%.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.287-289
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• 2012

The building construction industry of Korea was going through difficulties in improving productivity and competitiveness in international market. Therefore we expected to see the improvement in productivity by applying six-sigma based approach to general reinforced concrete construction work. As a result of applying DMAIC method, one of 6 sigma tools, we found that the most effective inspection items are 'Gap of forms' and 'status of clean'. We could see from this case study that the percentage of additional work days has decreased to 37.7% as a result of applying six-sigma based approach to reinforced concrete construction.

• East Asian Economic Review
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• v.23 no.1
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• pp.89-107
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• 2019

This paper ranks higher education in Korea based upon research productivity in business and economics disciplines. The number of SCI-level journal articles are tabulated using the Web of Science search engine, over the sample period from 1990 to 2016. The league table shows that many private universities dominate top-tier ranks, which is consistent with the school reputations most commonly cited by the general public in Korea. In contrast, many national universities appear in the second-tier, and their scanty performance in business and economics is in sharp contrast with our earlier findings in which national universities performed well in science and engineering fields (Jin and Kim, 2018). In addition, the ranking order in lower-ranked schools is found to be sensitive to a small change in publications, whereas the publication gap among top-tier schools is relatively large. Finally, unlike our general perception, the size of school does not matter for collaborative research. Some policy implications are discussed as a conclusion.

• Proceedings of the Fisheries Business Administration Society of Korea Conference
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• 2006.11a
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• pp.1-22
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• 2006

• Journal of the Korea Safety Management & Science
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• v.15 no.3
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• pp.151-161
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• 2013

This paper proposes a strategic model of linkage between productivity metrics and financial accounting metrics to properly evaluate the financial effect of TPM activities and the business performance. This linkage strategy provides a connection tool for clear communication between factory-level and headquarters that the metrics proposed by this paper ultimately improves a quality of support from the management by receiving the factors required for productivity activities in the practical field. This factor includes such as equipment, raw materials and labors. Here, we propose that chain reaction models using break down structure of productivity metrics and financial metrics enhance the knowledge sharing of KPI (Key Performance Indicator) which generally tend to create oversimplified communication between management in headquarters and employees in the practical fields. The productivity metrics include OEE(Overall Equipment Effectiveness) of TPM (Total Productive Maintenance), OLE (Overall Labor Effectiveness) of PAC(Performance and Analysis and Control) activities, and OYE (Overall Yield Effectiveness) of TMM(Total Material Management) activities. The financial accounting metrics include ROE(Return on Equity), ROA(Return on Asset), and AVR(Added-Value Rate). The suggested chain reaction model selects the financial metrics as initial stage and branch down until final stage of productivity metrics. When demand exceeds supply, an ideal speed rate, the lean OEE strategy can be initially applied to reduce the gap between the demand and supply, then apply variable costing to estimate correct amount of operating profit. In addition, the paper presents a new type of model for linkage between financial accounting metrics including CAPEX(Capital Expenditure), OPEX(Operating Expenditure), EVA(Economic Added Value), DCL(Degree of Combined Leverage), and TPM productivity activities including AM(Autonomous Maintenance), PM(Preventive Maintenance), MP(Maintenance Prevention) and QM(Quality Maintenance). In order to support the evidence of proposed linkage strategy, a case analysis on 52 projects from national TPM contest from 2011 to 2012 is analyzed. The case presents the classification of CAPEX and OPEX activities from TPM, and proposes the correct implementation of financial effect for TPM projects.

• Journal of Technology Innovation
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• v.22 no.1
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• pp.89-117
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• 2014

Employing female in the field of science and engineering is becoming increasingly important with diversity and creativity emerging as key factors to build Creative Economy. Under these circumstances, it is necessary to recognize and discourage gender discrimination in the labor market by analyzing wages - the market value of labor which determines one's economic status. This study uses the Oaxaca-Ransom decomposition (1994) to analyze the gender wage gap and identify factors influencing the pay gap in science and engineering labor force. The results of this study are as follows: First, the average wage of female scientists and engineers reaches only 65% of that of male labor force, and the male scientist and engineers are superior in terms of personal attributes, for instance, education background. Second, looking at the factors that influence wages, wage premiums are associated with higher education background, older age, longer period of service, and weekly working hours for both male and female in managerial positions. Third, the wage decomposition shows that in the case of science and engineering labor force, the productivity difference by personal attributes reaches about 58%, and gender discrimination by the characteristics of the labor market stands at about 41%. This means the wage gap by productivity level in science and engineering labor force is wider, and the gender gap is smaller compared to non-science and engineering fields. However, the results of an analysis on specialties and education background of male and female scientists and engineers suggest that the discrimination against women is more serious when the percentage of the female labor force is low and the percentage of temporary workers in the labor market is high. In order to eliminate this discrimination, it is necessary to reduce the imbalance of female scientists and engineers in the labor market, among others, while female scientists and engineers, themselves, need to make continuous efforts to strengthen their capabilities.