• Composites Research
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• v.24 no.3
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• pp.1-5
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• 2011

Since the environmental problems and new stricter regulations are forcing the industries to introduce more ecological materials for their products, biodegradable materials have attracted increasing attention. Among these materials, Polylactic acid(PLA) is a promising candidate for its modulus, strength, chemical resistance. However, PLA could not be used for automobile industries for its low heat resistance and impact strength. In this study natural fibers were (jute fiber was) introduced as reinforcements in order to improve heat resistance and impact strength of PLA. Especially for improving the adhesion between PLA and jute, various surface treatments were tried. With each treatment, we verified that the impact strength of composite was improved. With annealing treatment, we found a remarkable increase of heat resistance of PLA composite.

• Applied Chemistry for Engineering
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• v.18 no.4
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• pp.303-313
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• 2007

Various commercial catalysts used in chemical related applications have been disposed as an industrial waste when the catalytic activity of catalysts is not good enough to achieve an optimum yield. In addition, the amount of disposed three way catalysts (TWC) has been continuously increased. Considering the physicochemical, environmental, and economical characteristics, the deactivated spent catalysts can be treated in several alternative ways such as regeneration, recycling, and disposal. In view of the environmental and economical matters, the spent catalyst should be regenerated and used for the various purposes, although its activity is not as good as a fresh catalyst. On the other hand, spent catalysts containing noble and metal oxides can be applicable for the catalytic oxidation of volatile organic compounds (VOCs) by applying the proper treatment method. Therefore in this review the quantity of the spent catalysts and the available regeneration methods for the spent catalysts are briefly summarized and especially the proper regeneration method for applying the catalytic oxidation of VOCs and its results are introduced.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.51
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• pp.199-210
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• 1999

The number of car accident is Recently on the increase in Korea because of the explosive increase of cars, the poor road condition, the lack of safety facility, and others. The insurant with a accident has to decide whether receiving a insurance or not. In this paper, we represent a reasonable decision support material by calculating the approximate insurance fee based on the discount rate and premium additive rate, which is changed by the accident type and the accident expenditure. Practically, there is difference in the standard insurance rate and premium additive rate according to the accident type and the accident expenditure in Korea. The premium additive rate is assessed considering the number of accident, the pattern of accident, and the reason of accident for 3 years. In this paper, we represent a decision making method considering not only the first-time car accident but also the future car accident. For considering the repeated accident, we analyzed the real data accumulated until the year of 1996 from S Insurance Company, and estimated the probability density function between the first and the second-time accident, and executed the goodness of fit test using ARENA and STATISTICA software. Using this conditional PDF, we can calculate the insurance fee next 3 years and compare the insurance fee with the equivalent present value of cash flows. The program performing this analysis is represented, and written in VISUAL BASIC Language. We tried to suggest an accurate guideline for the insurant to decide the insurance coverage rationally, and tried to correct a wrong idea of dependence on the car insurance only by the amount of the accident expenditure. And we expect this study can generally be applied to many different accident types under the uncertain circumstances in our daily life.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.4
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• pp.10-20
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• 2017

The proportion of software in the automotive industry is steadily increasing due to the rapid technological development of automobile E/E parts. Because the automotive E/E technology is now on the basis of intelligent automobile and advanced safety automobile technology. The purpose of this study is to investigate the effect of organizational capability (organizational resource capability and management capability), process capability (process capability, customer Requirement management capability), performance dimension (motivation, participation level). In this study, we conducted questionnaires and statistical analysis on engineers (members of the Korea Advanced Automotive Technology Association) who perform research and development activities in the R&D organization of the automotive E/E part in South Korea. ANOVA is applied for the verification of the difference in performance measured by organizational capability, process maturity, and motivation participation level according to company characteristics (level of processing : supply chain configuration, annual sales, total SW development ratio). According to the results of this study, in order to improve the performance of ASPICE or ISO 26262-related consulting project, a different consulting approach strategy considering the characteristics of organization and personnel is needed. In summary, the analysis results for the three main treatment levels are as follows. The difference in organizational capacity, process capability and performance was found to be statistically significant according to supply chain configuration and annual sales, but it was found that the difference of response according to the proportion of total SW was not significant.

• Composites Research
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• v.33 no.3
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• pp.115-124
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• 2020

Laminate composites, especially Carbon fiber-reinforced composites are wide used in various industry such as aerospace and automotive industry due to their high specific strength and specific stiffness. However, the laminate composites has a big disadvantage that delamination occurs because the arrangement of the fibers is all arranged in the in-plane direction, which limits the field of application of the laminate composites. In this study, we first developed a laminate composites T-beam in which π-beam and flat plate were combined and optimized the design parameters through structural analysis and mechanical tests. Afterwards, 3D weave preform T-beam was developed by applying the same design parameters of laminate composites T-beams, and improved mechanical strength was achieved compared to laminated structures. These findings are expected to be applicable to existing laminated composite structures that require increased strength.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.36
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• pp.49-59
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• 1995

The vehicle navigation system is developed for helping driver to retrieve driving information more easily and fastly. Navigation System informs driver many pieces of driving information - roadway structure and system, on-line traffic condition, the position of vehicle, route guidance, destination and other information service. As the style of information is diverse and the amount of information is large, driver may have mental and visual overload. The display of information can disturb the driver's attention and this can cause accidents. This state is caused by the defect of human-machine interactions. When the navigation system is designed, human factors - cognitive, judgment, operating - must be considered. The display style must be designed simply and easily, not to be obstacle of human -machine interface. In this study, outside-in view display style and inside-out view display style are compared each other. Two factors are measured. One is cognitive factor-time of cognition on information that is displayed by screen display, cognition error rate. The other is image of screen display - subject's feeling about several styles of display, degree of subject's preference. The prototype of roadway is four kinds - Cross, T-cross, Y-cross and O-cross. Roadway display for test is taken from paper maps. Traffic condition display style, vehicle position display style and route guidance display style are taken from current display style. Traffic condition display style is symbol. Vehicle position display style and route guidance display style are described as color and symbol. The test on screen display is implemented doing given tasks. Then the test is analyzed statistically, The result of test analysis gives the guideline to the designer for the map display of the vehicle navigation system.

• Journal of Internet Computing and Services
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• v.20 no.3
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• pp.1-11
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• 2019

Today's software systems are becoming larger and more complicated, and the risk of accidents and failures have also grown larger. Software failures and accidents in industrial fields such as automobiles, nuclear power plants, railroad industries, etc. may lead to severe damage of property and human life. The safety-related international standards, such as IEC 61508 have been established and applied to industries for decades. The safety life cycle specified in the standards emphasize the activities to develop safety requirements through hazard and risk analysis in the early stage of software development. In this paper, we propose 'Hazard Analysis Process based on STPA using SysML' in order to ensure the safety of software at the early stage of software development. The proposed hazard analysis can be effectively performed minimizing the loss of hazard by using the BDD and the IBD of SysML to define the control structure of a system. The proposed method also improves the specification of the safety constraints(requirement) by using SD. As a result, it is possible to identify the hazard without missing and identify the hazard scenarios in detail, and safety can be sufficiently ensured in the early stage of software development.

• Journal of Digital Convergence
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• v.17 no.5
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• pp.217-223
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• 2019

A study in predicting defects of spot welding in real time in automotive field is essential for cost reduction and high quality production. Welding quality is determined by shear strength and the size of the nugget, and results depend on different independent variables. In order to develop the real-time prediction system, multiple regression analyses were conducted and the two dependent variables were obtained with sufficient statistical results with three independent variables, however, the quality prediction by the regression formula could not ensure accuracy. In this study, a multi-layer neural network circuit was constructed. The neural network by 10 dynamic resistance variables was constructed with three hidden layers to obtain execution functions and weighting matrix. In this case, the neural network was established with three independent variables based on regression analysis, as there could be difficulties in real-time control due to too many input variables. As a result, all test data were divided into poor, partial, and modalities. Therefore, a real-time welding quality determination system by three independent variables obtained by multiple regression analysis was completed.

• Convergence Security Journal
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• v.18 no.5_1
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• pp.99-104
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• 2018

Modern society has entered the era of the fourth industrial revolution beyond the information age. In other words, technology innovations such as life science, unmanned automobiles, drone, artificial intelligence, big data, robot technology, Internet of things, and nano-technology are leading the change of the world. In these technologies use and delivery of information is playing a key role, and the field of information security for the safe use of information has become an indispensable discipline. In this sense, it is necessary to standardize the curriculum of universities to foster security manpower to meet the needs of the era. In this paper, we develop and present a model to standardize the curriculum in the field of information security. Using this model, each educational institution will be able to select the necessary track or field to guide the students and cultivate information security manpower effectively.

• Applied Chemistry for Engineering
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• v.22 no.5
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• pp.508-513
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• 2011

Hemp is known as one of the most productive and useful plants, which grows quickly in a moderate climate with only moderate water and fertilizer. Traditionally in Korea, hemp bast is used to natural fibres, and remaining such as stem and root is treated as waste. Those of hemp by-products can be transformed to bio fuel such as bio-oil and activated carbon. To understand pyrolysis characteristics, thermogravimetric analysis were carried out in TGA, in which hemp by-products were mostly decomposed at the temperature range of $270{\sim}370^{\circ}C$. The corresponding kinetic parameters including activation energy and pre-exponential factor were determined by differential method over the degree of conversions. The values of activation energies for pyrolysis were increased as the conversion increased from 10 to 90%.