• 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.

• Journal of Korea Society of Waste Management
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• v.35 no.8
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• pp.692-700
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• 2018

In this study, the results of PBDEs and HBCDs of the products and waste that contain BFRs such as domestic electronic products, automobiles and textile products were compared with international management standards, and their excess rates were calculated. Deca-BDE was detected among the PBDEs in TV rear cover plastics, car seats, automotive interior plastics, and automobile shredding residues of products and waste containing BFRs. The comparison with Basel Convention management standards (1,000 mg/kg) for PBDE-containing wastes (4 types in total) shows that the excess rate of all samples was less than 1.5%. The estimated excess rate compared to the EU and Basel convention management standards (1,000 mg/kg) for PBDEs (4 species + deca-BDE) and TV rear cover plastics was 37.5% (30 of 80 samples exceeded the standards). The estimated excess rate compared to the Basel convention management standards (1,000 mg/kg) for HBCD, building materials products and waste was 15.7% (17 of 108 samples exceeded the standards). In the case of PBDEs, it is necessary to remove only the rear cover of CRT TV among the electric and electronic products and treat it in the flame retardant treatment facility to improve the recycling collection system. In the case of HBCD, it is necessary to appropriately dispose of the recycled materials, heat insulation materials, TV plastics, and styrofoam in marine fishery among construction materials and restrict the use as recycled raw materials.

• Korean Journal of Metals and Materials
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• v.47 no.11
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• pp.707-715
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• 2009

This paper deals with cyclic stress and strain responses during isothermal low cycle fatigue (LCF) and thermo-mechanical fatigue (TMF) loadings on Nb and Mo containing 15Cr stainless steel, which is used for exhaust manifolds in automobiles. The test temperatures ($T_{i}$) of the isothermal LCF were 600 and $800^{\circ}C$. The minimum temperature of the TMF test was $100^{\circ}C$ and the maximum temperaures ($T_{p}$) were varied between 500 and $800^{\circ}C$. In both loading conditions, weak cyclic softening is observed at $T_{i}=T_{p}=800^{\circ}C$, but the transition to strong cyclic hardening is completed with the temperature decrease below $T_i=600{\sim}700^{\circ}C$ for LCF and $T_{p}=500{\sim}600^{\circ}C$ for TMF. The stress-strain hysteresis loops in the TMF loading show a significant stress relaxation during compressive (heating) half cycle at $T_{p}>500^{\circ}C$, which develops tensile mean stress during cycling. Due to the stress relaxation, the TMF test sample reveals much lower dislocation density than the isothermally fatigued sample at the same temperature with $T_{p}$. A detailed correlation between fatigue microstructure and cycling deformation behavior is discussed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.4
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• pp.93-106
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• 2020

This research explores how imported automobile companies can develop their strategies to improve the outcome of their recalls. For this, the researchers analyzed patterns of recall demand, classified recall types based on the demand patterns and examined response strategies, considering plans on how to procure parts and induce customers to visit workshops, recall execution capacity and costs. As a result, recalls are classified into four types: U-type, reverse U-type, L- type and reverse L-type. Also, as determinants of the types, the following factors are further categorized into four types and 12 sub-types of recalls: the height of maximum demand, which indicates the volatility of recall demand; the number of peaks, which are the patterns of demand variations; and the tail length of the demand curve, which indicates the speed of recalls. The classification resulted in the following: L-type, or customer-driven recall, is the most common type of recalls, taking up 25 out of the total 36 cases, followed by five U-type, four reverse L-type, and two reverse U-type cases. Prior studies show that the types of recalls are determined by factors influencing recall execution rates: severity, the number of cars to be recalled, recall execution rate, government policies, time since model launch, and recall costs, etc. As a component demand forecast model for automobile recalls, this study estimated the ARIMA model. ARIMA models were shown in three models: ARIMA (1,0,0), ARIMA (0,0,1) and ARIMA (0,0,0). These all three ARIMA models appear to be significant for all recall patterns, indicating that the ARIMA model is very valid as a predictive model for car recall patterns. Based on the classification of recall types, we drew some strategic implications for recall response according to types of recalls. The conclusion section of this research suggests the implications for several aspects: how to improve the recall outcome (execution rate), customer satisfaction, brand image, recall costs, and response to the regulatory authority.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.3
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• pp.40-46
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• 2021

An automatic transmission of automobiles enables comfortable driving experience with lower transmission shifting jerks. However, the assembly structure is more complicated and requires additional components with lower efficiency than the manual transmission system. Extensive research has been conducted to improve the overall transmission efficiency by optimizing each component of the automatic transmission assembly. This study focuses on enhancing the friction torque of double angular contact ball bearings used in automatic transmission. The friction torque of the bearing varies with the operating conditions such as the operational load and rotating speed. Since reducing the friction torque of the bearing tends to deteriorate the durability of the bearing, it is necessary to design the bearing having a minimum required friction torque by determining the durability life of an automatic transmission assembly, In this study, the theoretical life and friction torque of conventional and newly-developed bearings are calculated. The difference in the friction torque between the new and existing bearings are also evaluated.

• Journal of the Korean Institute of Gas
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• v.26 no.1
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• pp.7-19
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• 2022

Hydrogen purification is generally performed through chemical and physical methods. Among various types of purification method PSA(Pressure Swing Adsorption) is widely used with its purification capacity and economic efficiency. In Korea, most of the hydrogen used in automobiles and power generation fuel cells is purified using PSA. Hydrogen produced in petrochemical complexes has difficulties in transportation. The government is planning to install hydrogen extractors that produce hydrogen directly from consumers in connection with the city gas supply chain, and companies are also installing related research and demonstration facilities one after another. Europe and others have recently established safety standards related to PSA and are making efforts for systematic safety management at the construction and operation stage, but domestic safety standards related to PSA are still insufficient. This study aims to identify problems of existing facilities through surveys and risk assessment by companies operating existing PSA, and to prepare domestic technical standards including them in overseas technical standards to promote the safety of new and existing PSA systems.

• Textile Coloration and Finishing
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• v.34 no.2
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• pp.109-116
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• 2022

Tire codes are made of materials such as hemp, cotton, rayon, nylon, steel, polyester, glass, and aramid are fiber reinforcement materials that go inside rubber to increase durability, driveability, and stability of vehicle tires. The reinforcement of the tire cord may construct a composite material using tires such as automobiles, trucks, aircraft, bicycles, and fibrous materials such as electric belts and hoses as reinforcement materials. Therefore, it is essential to ensure that the adhesive force between the rubber and the reinforced fiber exhibits the desired physical properties in the rubber composite material made of a rubber matrix with reinforced fibers. This study is a study on the heat treatment conditions for improving the adhesion strength of the tire cord and the reinforced fiber for tires. The core technology of the drying process is a uniform drying technology, which has a great influence on the quality of the reinforcement. Therefore, the uniform airflow distribution is determined by the geometry and operating conditions of the dryer. Therefore, this study carried out a numerical analysis of the shape of a drying nozzle for improving the performance of hot air drying in a dryer used for drying the coated reinforced fibers. In addition, the flow characteristics were examined through numerical analysis of the study on the change in the shape of the chamber affecting drying.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.9
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• pp.1330-1339
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• 2022

3D object detection generally aims to detect relatively large data such as automobiles, buses, persons, furniture, etc, so it is vulnerable to small object detection. In addition, in an environment with limited resources such as embedded devices, it is difficult to apply the model because of the huge amount of computation. In this paper, the accuracy of small object detection was improved by focusing on local features using only one layer, and the inference speed was improved through the proposed knowledge distillation method from large pre-trained network to small network and adaptive quantization method according to the parameter size. The proposed model was evaluated using SUN RGB-D Val and self-made apple tree data set. Finally, it achieved the accuracy performance of 62.04% at mAP@0.25 and 47.1% at mAP@0.5, and the inference speed was 120.5 scenes per sec, showing a fast real-time processing speed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.6
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• pp.473-480
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• 2021

In this paper, We analyze and present improvements to problems in software quality through Static Analysis for Open Source, which is widely used as the Flight Controller software for small unmanned aerial vehicle drones. MISRA coding rules, which are widely applied based on software quality, have been selected. Static analysis tools were used by LDRA tools certified international tools used in all industries, including automobiles, railways, nuclear power and healthcare, as well as aviation. We have identified some safety-threatening problems across the quality of the software, such as structure of open source modules, analysis of usage data, compliance with coding rules, and quality indicators (complexity and testability), and have presented improvements.

• Journal of the Korean Applied Science and Technology
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• v.38 no.6
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• pp.1533-1542
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• 2021

Eco-friendly polyurethane can be defined as a highly utilized material used in various fields. The various structural properties of the synthesis of isocyanates and polyols provide versatility and customization for use in the manufacturing field. The characteristics of polyurethane vary widely from soft touch coatings to hard building materials like rocks. These mechanical, chemical and biological properties and ease of alignment are drawing tremendous attention not only in the field of research but also in related industries. In order to improve the performance of water-dispersible polyurethane materials, it can be derived through processes such as adjusting the blending of raw materials and adding additives and nanomaterials. This study highlights the basic chemical structure of eco-friendly water-dispersible polyurethane in the fields of medical science, automobiles, coatings, adhesives, paints, textiles, marine industries, wood composite materials, and clothing.