• Information Systems Review
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• v.17 no.3
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• pp.113-133
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• 2015

In this paper, DEA analysis is employed to compare and evaluate the relative efficiency of a business intelligence (BI) system among five industrial groups such as IT and financial services, electricity and electronics, energy and chemistry, automotive and heavy machinery, and food and apparel. Especially, this study has analyzed the improving tendency of relative efficiency of the industrial groups since they adopted the BI System using Time-Window Analysis. The research findings show that the energy and chemical industry group tends to be remarkably more efficient than the other groups and the electrical and electronic industry turns out to gradually improve their efficiency since the adoption of the BI system.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.2
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• pp.81-86
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• 2011

Without a special mineral resources in Korea, such as petrochemical industries, electronics and automotive industries to supply the basic material, but remains a key industry locations. Gongjeongsang dealing with hazardous materials, such as a fire or explosion hazard, and from this site sangjonhae safety regulations to protect human and material disaster prevention activities are focused. However, depending on the actual implementation of standardized safety regulations as necessary if not originally intended, proper objectivity and reliability of safety regulations, as well as impaired resulting in a waste of public and private administrative power and petrochemical industries and the competitiveness of the entire drop factor will. Accordingly, this study petrochemical plant is applied to a representative safety regulations, items for their safety are needed and these regulations as being implemented that was identified, according to a study, some of the need for regulation and implementation both in terms of reliability was low.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.2
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• pp.144-155
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• 2019

One of the issues of the automotive industry today is autonomous driving vehicles. In order to achieve level 3 or higher as defined by SAE International, harmonization of autonomous driving technology and connected technology is essential. Current vehicles have new features such as autonomous driving, which not only increases the number of electrical components, but also the amount and complexity of software. As a result, the attack surface, which is the access point of attack, is widening, and software security vulnerabilities are also increasing. However, the reality is that the essential security requirements for vehicles are not defined. In this paper, based on real attacks and vulnerability cases and trends, we identify the assets in the in-vehicle network and derive the threats. We also defined the security requirements and derived essential security requirements that should be applied at least to the safety of the vehicle occupant through risk analysis.

• Journal of Korea Multimedia Society
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• v.22 no.5
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• pp.613-625
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• 2019

The rise of the Internet of Things (IoT) devices have greatly influenced many industries and one of them is healthcare where wearable devices started to track all your daily activities for better health monitoring accuracy and even down to tracking daily food intake in some cases. With the amounts of data that are being tracked and shared between from these devices, questions were raised on how to uphold user's data privacy when data is shared between these IoT devices and third party. With the blockchain platforms started to mature since its inception, the technology can be implemented according to a variety of use case scenarios. In this paper, we present a system architecture based on the healthcare system and IoT network by leveraging on multiple blockchain networks as the medium in between that should enable users to have direct authority on data accessibility of their shared data. We provide proof of concept implementation and highlight the results from our testing to show how the efficiency and scalability of the healthcare system improved without having a significant impact on the performance of the Electronic Medical Record (EMR) that mostly affected by the previous solution since these solutions directly connected to a public blockchain network and which resulted in significant delays and high cost of operation when a large amount of data or complicated functions are involved.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.3
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• pp.82-87
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• 2019

Recently, plastic materials have become more diversified, and the development of materials with excellent mechanical properties and plasticity has enabled wider application, miniaturization, and refinement of injection molded products. As a result, the utilization of these products in household goods, electronics, automotive parts, and aircraft parts is increasing in almost all industries. Injection molded parts are often used externally on finished commercial products. This means that the injection mold industry is very important to the value of these products. For this reason, the industry is performing research on the precision and efficiency of the injection molding process. In this study, we investigated the applicability of the core in core cooling method to the problem of product deformation due to temperature variation in existing injection mold designs. We also characterized the cooling performance of an injection mold when using this cooling method.

• Journal of Auto-vehicle Safety Association
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• v.13 no.2
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• pp.30-34
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• 2021

Electrical failures and reliability problems of electronic components by ionic migration between adjacent device terminals have become an issue in automotive electronics. Especially unlike galvanic corrosion, ionic migration is occurred at high temperature and high humidity under applied electric field condition. Until now, although extensive studies of the ionic migrations dealing with PCBs, electrodes, and solders were reported, there is no study on the effect of insulation polymers and metallic fillers for ionic migration. In this research, therefore, ionic migration induced by the types and contents of polymers and metallic fillers, and variety conditions of temperature, humidity, and applied voltage was studied in detail. Ester and amide types of liquid crystal polymer (LCP) and poly (phthalamide) (PPA) were used as base polymers, respectively and compounded with the metallic fillers of Copper iodide (CuI), Zinc stearate (Zn-st), or Calcium stearate (Ca-st) in various compositions. The compounding polymers were fabricated in IPC-B-24 of SIR test coupon according to ISO 9455-17 with Cu electrodes for ionic migration test. While there is no change in LCP-based samples, ionic migration in PPA compounding sample with a high water absorption property was accelerated in the presence of 0.25 wt% or above of CuI at the environmental conditions of 85℃, 85% RH and 48V. The dendritic short-circuit growth of Cu caused by ionic migration between the electrodes on the surface of compounded polymers was systematically observed and analyzed by using optical microscopy and SEM (EDX).

• Tribology and Lubricants
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• v.36 no.6
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• pp.365-370
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• 2020

Recently, additive manufacturing (AM) technology has been applied to various industries such as automotive, aviation, medical, and electronics. Most prior studies are limited to the mechanical properties of printed materials, and few studies are being conducted on their tribological characteristics. However, the friction and wear characteristics of the material should be studied in order to utilize the components manufactured using AM technology as mechanical parts. In this study, the friction and wear characteristics of acrylonitrile-butadiene-styrene (ABS)-like resin printed with stereo lithography apparatus (SLA) 3D printing are evaluated according to the viscosity of silicon oil lubricant using a ball-on-disk experiment. Lubricants with a viscosity of 500, 1000, and 2000 cSt are prepared for the experiment. If silicon oil lubricants are used during the ball-on-disk test, the coefficient of friction (COF) and wear rates are significantly reduced, and the higher the viscosity of the lubricant, the lower will be the COF and wear rates. It is also verified that the temperature of the specimen owing to friction also decreases according to the viscosity of the lubricant. This is because of the silicon oil film thickness, and the higher the viscosity of the lubricant, the thicker will be the oil film. More studies on the tribological characteristics of 3D printing materials and suitable lubricants will be required to use 3D printed parts as mechanical elements.

• Journal of IKEEE
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• v.25 no.4
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• pp.762-765
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• 2021

In this paper, an automotive ECU (electronic control unit) with Kalman filter accelerator is designed and implemented. RISC-V is exploited as a processor core. Accelerator for Kalman filter matrix operation, CAN (controller area network) controller for in-vehicle network, and LIN (local interconnect network) controller are designed and embedded. Kalman filter operation consists of time update process and measurement update process. Current state variable and its error covariance are estimated in time update process. Final values are corrected from input measurement data and Kalman gain in measurement update process. Usually floating-point multiplication is exploited in software implementation, but fixed-point multiplier considering accuracy analysis is exploited in this paper to reduce hardware area. In 28nm silicon fabrication, its operating frequency, area, and gate counts are 100MHz, 0.37mm², and 760k gates, respectively.

• Journal of IKEEE
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• v.26 no.4
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• pp.614-621
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• 2022

This paper proposes RIDS (Random Forest-Based Intrusion Detection), which is an intrusion detection system to detect hacking attack based on random forest. RIDS detects three typical attacks i.e. DoS (Denial of service) attack, fuzzing attack, and spoofing attack. It detects hacking attack based on four parameters, i.e. time interval between data frames, its deviation, Hamming distance between payloads, and its diviation. RIDS was designed in memory-centric architecture and node information is stored in memories. It was designed in scalable architecture where DoS attack, fuzzing attack, and spoofing attack can be all detected by adjusting number and depth of trees. Simulation results show that RIDS has 0.9835 accuracy and 0.9545 F1 score and it can detect three attack types effectively.

• Journal of IKEEE
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• v.26 no.4
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• pp.553-559
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• 2022

In this paper, RC snubber circuit design technology for oscillation suppression in half-bridge configuration of cascode gallium nitride (GaN) field effect transistors (FETs) is analyzed. A typical wide band-gap (WBG) device, cascode GaN FET, has excellent high-speed switching characteristics. However, due to such high-speed switching characteristics, a false turn-off problem is caused, and an RC snubber circuit is essential to suppress this. In this paper, the commonly used experimental-based RC snubber design technique and the RC snubber design technique using the root locus method are compared and analyzed. In the general method, continuous circuit changes are required until the oscillation suppression performance requirement is met based on experimental experience . However, in root locus method, the initial value can be set based on the non-oscillation R-C map. To compare the performance of the two aforementioned design methods, a simulation experiment and a switching experiment using an actual double pulse circuit are performed.