• Journal of the Korean Society for Precision Engineering
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• v.33 no.7
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• pp.551-558
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• 2016

Reduction of welding residual stress is very important in the railway industry, but calculating its distribution in structures is difficult because welding residual stress formation is influenced by various parameters. In this study, we developed a finite element model for simulating the repair welding process to recover a surface damaged rail, and conducted a series of parametric studies while varying the cooling rate and the duration of post weld heat treatment (PWHT) to find the best conditions for reducing welding residual stress level. This paper presents a three-dimensional model of the repair welding process considering the phase transformation effect implemented by the ABAQUS user subroutine, and the results of parametric studies with various cooling rates and PWHT durations. We found that heat treatment significantly reduced the residual stress on the upper rail by about 170 MPa.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.11
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• pp.479-489
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• 2020

The purpose of this paper is to uncover whether and how contextual factors (information exchange, participation, trust in management, and training), relate to resistance to change. It also explores the mediating effect of perceived impact of change on the relations between contextual factors and resistance to change. This study is conducted in several manufacturing plants in food processing industry in Vietnam, which is implementing a top-down large-scale change - Lean transformation, adopting Total Productive Maintenance (TPM) program, to be specific. The findings suggest that all four contextual factors are negatively associated with resistance to change, in which training had the strongest impact. Also, the perceived change impact partially mediates the relationships between the four contextual factors and resistance to change. The practical implications of this paper are that employees who receive adequate, timely and useful information relating to change are less likely to show opposing behaviors towards change. Fostering trust in management among employees, and employee involvement in decision-making, also have a significant influence when addressing employee resistance to change. Employees who are well-trained, well-equipped with tools and knowledge about the change, are less likely to resist as they view the benefits of changes more significant than the risks.

• Journal of Microbiology and Biotechnology
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• v.28 no.7
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• pp.1217-1224
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• 2018

Seaweeds produce antioxidants to counteract environmental stresses, and these antioxidant genes are regarded as important defense strategies for marine algae. In this study, the expression of Pyropia yezoensis (Bangiales, Rhodophyta) ascorbate peroxidase (PyAPX) and manganese-superoxide dismutase (PyMnSOD) was examined by qRT-PCR in P. yezoensis blades under abiotic stress conditions. Furthermore, the functional relevance of these genes was explored by overexpressing them in Chlamydomonas. A comparison of the different expression levels of PyAPX and PyMnSOD after exposure to each stress revealed that both genes were induced by high salt and UVB exposure, being increased approximately 3-fold after 12 h. The expression of the PyAPX and PyMnSOD genes also increased following exposure to $H_2O_2$. When these two genes were overexpressed in Chlamydomonas, the cells had a higher growth rate than control cells under conditions of hydrogen peroxide-induced oxidative stress, increased salinity, and UV exposure. These data suggest that Chlamydomonas is a suitable model for studying the function of stress genes, and that PyAPX and PyMnSOD genes are involved in the adaptation and defense against stresses that alter metabolism.

• Journal of Powder Materials
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• v.23 no.6
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• pp.458-465
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• 2016

A $TiO_2$/CNT nanohybrid photocatalyst is synthesized via sol-gel route, with titanium (IV) isopropoxide and multi-walled carbon nanotubes (MWCNTs) as the starting materials. The microstructures and phase constitution of the nanohybrid $TiO_2$/CNT (0.005wt%) samples after calcination at $450^{\circ}C$, $550^{\circ}C$ and $650^{\circ}C$ in air are compared with those of pure $TiO_2$ using field-emission scanning electron microscopy and X-ray diffraction, respectively. In addition, the photocatalytic activity of the nanohybrid is compared with that of pure $TiO_2$ with regard to the degradation of methyl orange under visible light irradiation. The $TiO_2$/CNT composite exhibits a fast grain growth and phase transformation during calcination. The nanocomposite shows enhanced photocatalytic activity under visible light irradiation in comparison to pure $TiO_2$ owing to not only better adsorption capability of CNT but also effective electron transfer between $TiO_2$ and CNTs. However, the high calcination temperature of $650^{\circ}C$, regardless of addition of CNT, causes a decrease in photocatalytic activity because of grain growth and phase transformation to rutile. These results such as fast phase transformation to rutile and effective electron transfer are related to carbon doping into $TiO_2$.

• The Korean Journal of Applied Statistics
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• v.31 no.2
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• pp.189-204
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• 2018

This study is on forecasting the electricity consumption of an industrial manufacturing building called GGM from January 2014 to April 2017. We fitted models using SARIMA, SARIMA + GARCH, Holt-Winters method and ARIMA with Fourier transformation. We also forecasted electricity consumption for one month ahead and compared the predicted root mean square error as well as the predicted error rate of each model. The electricity consumption of GGM fluctuates weekly and annually; therefore, SARIMA + GARCH model considering both volatility and seasonality, shows the best fit and prediction.

• Journal of Advanced Navigation Technology
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• v.27 no.2
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• pp.228-234
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• 2023

As the increasing demand for high-quality software, there is huge requiring for quality certification of international standards, industrial functional safety (IEC 61508), automotive (ISO 26262), embedded software guidelines for weapon systems, etc., in the industry. Software companies are very difficult to systematically acquire the quality certification in terms of cost and manpower of Startup, venture small-sized companies. For their companies one test case automatic generation is considered as a core technique to evaluate or improve software quality. This paper proposes a test case automatic generation method based on the design decision table for system and software design verification. We apply the proposed method with OMG's standard techniques of metamodel and model transformation for automatically generating test cases. To do this, we design the metamodels of design decision table (Model) and test case document (Text) and define model transformation to automatically generate test cases, which will expect to easily work MC/DC coverage.

• Journal of the Korea Furniture Society
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• v.22 no.3
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• pp.160-173
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• 2011

Increased internet use under a ubiquitous environment may be called as a great human information space revolution followed by Industrial Revolution. This revolution is exerting its significant influence over all the industry as a whole with speed faster than that of any other times. Along with this trend, if furniture design field that leads living culture should fail to jump on this main stream without noticing it, it may be reduced to a unpopular field some day without any sign of recovery. Under this background, this study is intended to recognize a goal aiming at understanding our rapidly changing living environment and leading our way positively. Currently, our surrounding living environment is immersed in computers here and there and Mark Weiser once defined a system that moves in advance before an action as ubiquitous computing and in this respect, I am going to observe a detailed transformation process of space. First nature of the space may be defined as atoms, a physical space equivalent to a spatial element and Bits space that is untouchable is usually called as 2nd space and a combination of atoms and Bits is an intelligent space - 3rd space - that can be intelligible without touching it and finally, this space is called as a ubiquitous space. This spatial transformation is developed by several changes of living environment and we may call it as living trend or interior design trend. Transformation in terms of social perspective, space structural perspective and digital technique perspective may be enumerated. These transformations were surveyed based on its contents being implemented at a future housing exhibition hosted by 5 construction companies along with fusion of information furniture and furniture depending on each housing space. In conclusion, it could be realized that most of the companies were decorating future space by implementing ubiquitous environment as a success factor of future housing market. It may be meaningful to note once again that under an interior environment, a fusion of furniture and information furniture is required considering interior trend elements.

• Journal of Information Technology Services
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• v.20 no.4
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• pp.23-33
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• 2021

The prolonged coronavirus 19 (COVID-19) has caused serious problems such as job losses and youth unemployment, but as the fourth industrial revolution and digital transformation accelerate, the importance of SW is highlighted and more qualified jobs are expected in the SW industry. However, domestic SW companies are having difficulties in not properly recognizing the value of SW products. Among many related issues, commercial SW maintenance-related issues are representative, and the main problem is the difference in the maintenance fee rates between domestic and foreign SW. In this study, the expected job creation effect when the SW maintenance rate is raised was analyzed using data related to the SW industry and commercial software. As a result of the analysis, the amount required to raise the commercial SW maintenance rate by 1% is 162 billion won. If all of these are used for employment, the expected new job creation effect is 3,240 jobs per year, and 15,451 jobs are created per year when calculated and estimated as the effect of increasing sales through the employment inducement coefficient. In addition, the amount required to raise the current average maintenance rate of 11.1% to 15% is 631.9 billion won, and it was possible to estimate the effect of creating jobs for 12,648 people based on the simple average wage and 60,259 people from the sales increase effect.

• Fashion & Textile Research Journal
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• v.23 no.6
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• pp.790-798
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• 2021

With digital technology innovation, increased data access and mobile network use by consumers, products and services are changing toward pursuing differentiated values for personalization, and personalized markets are rapidly emerging in the fashion industry. This study aims to identify trends in digital customized automation technology by deriving types of digital customizing and analyzing cases by type, and to present directions for the development of digital customizing processes and the use of technology in the future. As a research method, a literature study for a theoretical background, a case study for classification and analysis of types was conducted. The results of the study are as follows. The types of digital customizing can be classified into three types: 'cooperative customization', 'selective composition and combination', 'transparent suggestion', and automation technologies shown in each type include 3D printing, 3D virtual clothing, robot mannequin, human automatic measurement program, AR-based fitting service, big data, and AI-based curation function. With the development of digital automation technology, the fashion industry environment is also changing from existing manufacturing-oriented to consumer-oriented, and the production process is rapidly changing with IT and artificial intelligence-based automation technology. The results of this study hope that digital customized automation technology will meet various needs of personalization and customization and present the future direction of digital fashion technology, where fashion brands will expand based on the spread of digital technology.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.103-113
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• 2020

The construction industry is undergoing a digital transformation in which Building Information Modelling (BIM) is a key technology. The potential of BIM in several areas such as design optimization, time management, cost management, and asset management/facility management (AM/FM) is widely acknowledged by the AECO (Architecture, Engineering, Construction, and Operation) industry around the world. However, BIM implementation in construction projects is faced with problems such as project delay and cost overruns. The lack of identification of risks in BIM projects and standard guidelines on mitigation techniques furthers poor performance, dissatisfaction, and disputes between employers and project participants, which results in low BIM adoption rates. Therefore, the objective of this paper is to identify the potential risks in BIM implementation under the primary categories - (1) technical, (2) contractual, (3) management-related, and (4) personnel-related risks in BIM projects and present solutions to reduce, manage, and mitigate risks. To meet the objective of this paper, a survey was designed and conducted in the Hong Kong construction industry in which over 140 respondents from different disciplines, with experience in BIM projects, have participated. Based on the analysis of the survey data, the most severe and frequently occurring BIM risks and their potential mitigation strategies were identified and discussed in this paper.