• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.428-439
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• 2020

The continuous development of information and communication technologies has resulted in an exponential increase in data. Consequently, technologies related to data analysis are growing in importance. The shipbuilding industry has high production uncertainty and variability, which has created an urgent need for data analysis techniques, such as machine learning. In particular, the industry cannot effectively respond to changes in the production-related standard time information systems, such as the basic cycle time and lead time. Improvement measures are necessary to enable the industry to respond swiftly to changes in the production environment. In this study, the lead times for fabrication, assembly of ship block, spool fabrication and painting were predicted using machine learning technology to propose a new management method for the process lead time using a master data system for the time element in the production data. Data preprocessing was performed in various ways using R and Python, which are open source programming languages, and process variables were selected considering their relationships with the lead time through correlation analysis and analysis of variables. Various machine learning, deep learning, and ensemble learning algorithms were applied to create the lead time prediction models. In addition, the applicability of the proposed machine learning methodology to standard work hour prediction was verified by evaluating the prediction models using the evaluation criteria, such as the Mean Absolute Percentage Error (MAPE) and Root Mean Squared Logarithmic Error (RMSLE).

• The Journal of shipping and logistics
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• v.35 no.1
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• pp.93-109
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• 2019

This study applied the statistically significant factors to the short-run model in the existing nonlinear long-run equilibrium relation analysis for the forecasting of maritime economy using the mixed cycle model. The most common univariate AR(1) model and out-of-sample forecasting are compared with the root mean squared forecasting error from the mixed-frequency model, and the prediction power of the mixed-frequency approach is confirmed to be better than the AR(1) model. The empirical results from the analysis suggest that the new approach of high-level mixed frequency model is a useful for forecasting marine industry. It is consistent that the inclusion of more information, such as higher frequency, in the analysis of long-run equilibrium framework is likely to improve the forecasting power of short-run models in multivariate time series analysis.

• Korea Trade Review
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• v.45 no.4
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• pp.107-123
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• 2020

The purpose of this paper is to analyze the Granger Causality relations between Korean FDI and exports in Vietnam using time-series from 2005 to 2019. Using 15-industry semi-annual data of Korean FDI and exports toward Vietnam, the Granger Causality Tests were conducted. Var and VEC models were decided after unit-root and cointegration tests of variables. Findings and implications of the empirical tests are as follows. First, unexpectedly FDI did not Grange-cause exports only in one direction. In two industries, food & beverage and medical & chemical products, there were Granger causality relations in both directions. In eight industries including print, publishig, pulp & paper, exports did Grange-cause FDI. In the rest of five industries including automative & trailer industry, there were no Granger Causality relation in both directions. Second, we presume that the both direction-causality relations are desirable phenomenon for Korea. Because Korean FDI and exports are increasing at the same time. On the other hand, substitution relationship between Korea's exports and FDI occur in the industry that exports did Grange-cause FDI. Finally, more in-depth researches considering Vietnam's consumer demand and the oriented characteristics of FDI are needed. The results of this research will contribute to understand structural patterns of FDI and exports in Vietnam and to make investment and export decisions.

• Journal of the Semiconductor & Display Technology
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• v.22 no.3
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• pp.62-66
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• 2023

With the advancement in technology and rapid increase in the demand for microelectromechanical systems (MEMS) based inertial measurement units (IMUs), high-volume production and test system remain a major challenge for the MEMS industry. To compete with the challenging market of Industry 4.0, here we developed an automatic test system to evaluate the performance of the ovenized IMU sensors as well as analyze the data. The automatic test system was developed by interfacing a commercial MEMS IMU (BMI 088) using LabVIEW. The BMI 088 was tested experimentally for long-term bias stability, ON/OFF bias repeatability, and root mean square (rms) noise. Furthermore, the data was analyzed through the developed test system. The results show that the automatic test system has improved the test time and reduced human effort. The developed automatic test system is a significant approach to MEMS research and development (R&D) to increase and improve the mass production of IMUs.

• Journal of the Korean Society of Costume
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• v.64 no.2
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• pp.50-69
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• 2014

Sustainability has been a big issue over the whole global industry lately and is an important fashion trend that reflects the modern phase of the time. The concept of sustainable fashion includes physical fashion products made from eco-friendly or recycle materials as well as ethical value such as corporate social responsibility for environment, labor or working condition. Fashion companies of advanced countries who are aware of the geo-environmental and ethical issues found that generating profits by setting trends and pursuing external beauty can no longer be the ultimate goal of fashion companies, and started to recognize the importance of sustainable fashion as a future-oriented trend. Not only fashion industry but also governments of advanced countries have been playing a leading role to educate the people regarding the importance of sustainable fashion and making large investments to foster industry specialists in educational institution. The aim of this study is to propose sustainable fashion design education program that fits the domestic university curriculum and government-leading education program in order to set the foundation for sustainable fashion industry. Thus, this study investigates successful cases of foreign government-led sustainable fashion education that can be introduced to improve domestic sustainable fashion education. The empirical study of the research is developing 12-15 week university level education program to foster specialists in sustainable fashion. The survey carried out by the students who participated in the program shows the change of perception on sustainable fashion. Developed university level program can be spread to municipal corporation, school of continuing education, and etc. in order to derive participation and problem perception of the citizens on sustainability. Developing systemized sustainable fashion design education program would be the first step of sustainable fashion by educating students who will take the leading role in the future fashion industry. Moreover, it can strongly influence future customer education as well as a special education inducing interest on sustainability in everyday life. A follow-up study is expected to serve as a foundation for sustainable fashion to take root successfully in the fashion industry.

• Convergence Security Journal
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• v.13 no.5
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• pp.129-135
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• 2013

The revised security industry law revised 17 provisions among 31 provisions in order to root out the violent event. The main contents of the revised security industry law is the intensitfication of the required condition of permission, intensitfication of the obligation, management strengthening of the public resentment of group field, official, reason of expansion of the expenses instructor and guard, dress and equipment, vehicle, intensitfication of the managing director, intensitfication of the punishment, and etc. However, there is the problem including the putting under an obligation of the arrangement new appointment education, cause provider punishment of the service company violence, awareness of the police to the security company, excessive regulation, intensification of punishment problem, supervision power intensitfication of the revised security industry law is excessive the police, and etc. The individual responsibility education completion method and public resentment of group field in addition to is thought in order to solve this that exclusion of the prior education obligation, revision of the security industry law, burden on tax payers of the extra charge, punishment of the violence request contract trader, introduction of the guard qualification certificate system, and etc. are needed.

• Journal of Korea Game Society
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• v.5 no.4
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• pp.39-48
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• 2005

The gift coupon system was introduced in the AWP(Amusement With Prize) Game Industry in February 2002 to revitalize the sluggish domestic game industry and establish the cultural industry base. Today, however, speculations regarding these coupons are fast becoming a serious social issue. Therefore, this study proposes the establishment of the MCTF Management System as a possible solution to the analysis and resolution of the problem of gift coupons aimed at promoting the AWP Game Industry and ensuring its soundness as well as bridging the gap between the domestic and international game markets in terms of the industrial structure; thus securing global competitiveness. Unlike any other measure taken to date to prevent speculations, the MCTF Management System can eradicate problems related to coupons offered for free in the AWP Game Industry. This strategic system consists of Merchandise Coupon Management, Central Management, Tripartite Guarantee Management, and Fund Management System. Finally, this system is expected to help root out the problems related to gift coupons.

• Korean Journal of Plant Resources
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• v.31 no.4
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• pp.283-293
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• 2018

This study was performed to analysis of chemical constituent in Polygonum multiflorum root (PMR) by different dry methods (hot-air dry, shade dry, and freeze dry). The results are summarized as followings; major free sugar were detected fructose, glucose, and sucrose in dried PMR based on various dry methods. The highest content of free sugars was found in freeze dried PMR. The four organic acids were detected in dried PMR by HPLC analysis. The content of oxalic acid in shade dried PMR was higher than the dried PMR by different dry methods. The content of total amino acid and essential amino acids were high in the orders of freeze drying > shade drying > hot-air drying. The potassium and magnesium levels of freeze dried PMR was significantly higher than the other drying method of PMR. Whereas the calcium and sodium levels were higher in hot-air dried PMR. The major fatty acids were determined the linoleic acid in PMR by different dry methods.

• Journal of the Korean Wood Science and Technology
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• v.44 no.6
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• pp.890-896
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• 2016

Paulownia tomentosa is one of fast-growing wood species in Korea. In order to evaluate the solid bioenergy properties of Paulownia tree, this study examined the heating value, moisture content (MC), pH and proximate analysis of stem, branch, root, bark and leaf. The heating values of wood parts were slightly higher than those of bark and leaf, and that of branch was the highest among all the samples. The higher moisture content of bark and leaf referred to their lower heating value. Also, the pH of stem, branch and root was similar and lower than those of bark and leaf. The ash content of bark and leaf was much higher than that of wood parts, which is the one of the reasons for effect on the lower heating value and higher pH. While, the volatile matter content (VMC) of bark and leaf was lower than those of wood parts. The bark showed the highest fixed carbon content (FCC), while the FCC of stem was the lowest among all the samples. The obtained results are encouraging that the Paulownia tree could be totally utilized as alternative fuels for bioenergy production.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.11
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• pp.1705-1712
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• 2001

Mechanical component has striation with constant width and SEM can estimate fracture type and loading condition. SEM has benefit to fatigue fracture analysis but striation can be observed according to the kind of material and range of crack growth rate and can't. In this case, it needs AFM that can measure 3-dimensional surface profile with resolution of atomic size. In this study. to find fracture reason of torsion-mounted blade in nuclear plant, we estimate the relation between stress intensity factor range and root mean square roughness in 12% Cr steel by AFM and predict in-service loading condition of turbine blade. failure analysis is performed by finite element method and Goodman diagram on torsion-mounted blade.