• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.707-710
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• 2001

Brakes are one of the important safety parts in cars. The requirements of brakes in performance, in comfort, and working lifetime are high. This paper presents the static analysis on the stress and temperature of a automotive drum brake. The particular interest is the distribution of the contact pressure between brake lining and drum. The problems to be solved are the effects of friction coefficient, actuation force, temperature, and brake component's stiffness. The contact problem includes friction, and is solved using the ABAQUS.

• 공학교육연구
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• 제22권2호
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• pp.16-27
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• 2019

In order to note some points necessary for developing the cornerstone design course concentrating on conceptual design through that students acknowledge that engineering design is not to make things but to produce knowledge not only meet requirements of clients, users, and stake holders but also to solve problems, this paper describes the contents for the course that covers conceptual design as well as embodiment design, explains some ways and tools both for guiding students and for asking for study of lecture materials, and discuss things to be considered when faculty designs the course.

• 한국ITS학회 논문지
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• 제18권2호
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• pp.144-155
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• 2019

오늘날 자동차 산업의 화두 중 하나는 자율주행차량이다. 국제자동차기술자협회(SAE International)가 정의한 레벨 3이상을 달성하기 위해서는 자율주행 기술과 커넥티드 기술의 조화가 필수적이다. 현재의 차량은 자율주행과 같은 새로운 기능을 가지게 됨에 따라 전장 부품의 수뿐 만 아니라 소프트웨어의 양과 복잡성도 늘어났다. 이로 인해 공격 표면(Attack surface)이 확대되고, 소프트웨어에 내재된 보안 취약점도 늘어나고 있다. 실제로 커넥티드 기능을 가진 차량의 보안 취약점을 악용하여 차량을 강제 제어할 수 있음이 연구자들에 의해 증명되기도 했다. 하지만 차량에 적용 되어야 하는 필수적인 보안 요구 사항은 정의되어 있지 않는 것이 현실이다. 본 논문에서는 실제 공격 및 취약점 사례를 바탕으로 차량내부네트워크(In-Vehicle Network)에 존재하는 자산을 식별하고, 위협을 도출하였다. 또한 보안요구사항을 정의 하였고, 위험 분석을 통해 사이버 보안으로 인한 안전 문제를 최소화하기 위한 필수 보안 요구 사항을 도출하였다.

• International Journal of Internet, Broadcasting and Communication
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• 제15권3호
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• pp.219-230
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• 2023

With the development of autonomous driving technology, as the use of software in vehicles increases, the complexity of the system increases and the difficulty of development increases. Developments that meet ISO 26262 must be carried out to reduce the malfunctions that may occur in vehicles where the system is becoming more complex. ISO 26262 for the functional safety of the vehicle industry proposes to consider functional safety from the design stage to all stages of development. Specifically at the software level, the requirements to be complied with during development and the requirements to be complied with during verification are defined. However, it is not clearly expressed about specific design methods or development methods, and it is necessary to supplement development guidelines. The importance of analysis and verification of requirements is increasing due to the development of technology and the increase of system complexity. The vehicle industry must carry out developments that meet functional safety requirements while carrying out various development activities. We propose a process that reflects the perspective of system engineering to meet the smooth application and developmentrequirements of ISO 26262. In addition, the safety analysis/verification FMEA processforthe safety of the proposed ISO 26262 function was conducted based on the FCAS (Forward Collision Avoidance Assist System) function applied to autonomous vehicles and the results were confirmed. In addition, the safety analysis/verification FMEA process for the safety of the proposed ISO 26262 function was conducted based on the FCAS (Forward Collision Avoidance Assist System) function applied to the advanced driver assistance system and the results were confirmed.

• 대한안전경영과학회지
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• 제15권3호
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• pp.61-69
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• 2013

According to ISO 26262 (the international standard on functional safety for automotive industry), the functional safety should be considered during the whole automotive systems life cycle from the design phase throughout the production phase. In order to satisfy the standard, the automotive and related industry needs to take appropriate actions while carrying out a variety of development activities. This paper presents an approach to coping with the standard. Analyzing the standard indicates that the safety issues of the automotive systems should be handled with a system's view whereas the conventional approach to solving the issues has been practiced with focus on the component's level. The aforementioned system's view implies that the functional safety shall be incorporated in the system design from both the system's life-cycle view and the hierarchical view for the structure. In light of this, the systems engineering framework can be quite appropriate in the functional safety development and thus has been taken in this paper as a problem solving approach. Of various design issues, the analysis and verification of the safety requirements for functional safety is a key study subject of the paper. Note, in particular, that the conventional FMEA (failure mode effects analysis) and FTA (fault tree analysis) methods seem to be partly relying on the insufficient experience and knowledge of the engineers. To improve this, a systematic method is studied here and the result is applied in the design of an ABS braking system as a case study.

• 한국자동차공학회논문집
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• 제20권6호
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• pp.1-8
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• 2012

Multidisciplinary design optimization (MDO) for a suspension component of the vehicle front suspension was performed in this research. Shapes and thicknesses of the subframe were optimized to satisfy multi-disciplinary design requirements; weight, fatigue, crash, noise, vibration, and harshness (NVH), and kinematic and compliance (K&C). Analyses procedures of the performance disciplines were integrated and automated by using the process integration and design optimization (PIDO) technique, and the integrated and automated analyses environments enabled various types of analytic design methodologies for solving the MDO problem. We applied an approximate optimization technique which involves sequential sampling and metamodeling. Since the design variables for thicknesses should be dealt as discrete variables. the evolutionary algorithm is selected as optimization technique. The MDO problem was formulated three types of problems according to the order of priorities among the performance disciplines, and the results of MDO provided design alternatives for various design situations.

• 한국정밀공학회지
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• 제26권2호
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• pp.45-53
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• 2009

Today, reduction of $CO_2$ exhaustion gas for global-warming prevention becomes important issues in all industrial fields. Hydraulic systems have been widely used in industrial applications due to high power density and so on. However hydraulic pump is always being operated by engine or electric motor in the conventional hydraulic system. Therefore most of the conventional hydraulic system is not efficient system. Recently, an electro-hydraulic hybrid system, which combines electric and hydraulic technology in a compact unit, can be adapted to a wide variety of force, speed and torque requirements. In the electro-hydraulic hybrid system, hydraulic pump is operated by electric motor only when hydraulic power is needed. Therefore the electro-hydraulic system can reduce the energy consumption drastically when compared to the conventional hydraulic systems. This paper presents a new kind of hydraulic load simulator which is composed of electro-hydraulic hybrid system. Disturbances in the real working condition make the control performance decrease or go bad. QFT controller is designed to eliminate or reduce the disturbance and improve the control performance of the electro-hydraulic load simulator. Experimental results show that the proposed controller is verified to apply for electro-hydraulic hybrid system with varied external disturbances.

• 한국자동차공학회논문집
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• 제21권3호
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• pp.88-97
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• 2013

This paper presents a robust air-to-fuel ratio (AFR) control algorithm for managing exhaust gas recirculation (EGR) systems. In order to handle production tolerance, deterioration and parameter-varying characteristics of the EGR system, quantitative feedback theory (QFT) is applied for designing the robust AFR control algorithm. A plant model of EGR system is approximated by the first order transfer function plus time-delay (FOPTD) model. EGR valve position and AFR of exhaust gas are used as input/output variables of the plant model. Through engine experiments, parameter uncertainty of the plant model is identified in a fixed engine operating point. Requirement specifications of robust stability and reference tracking performance are defined and these are fulfilled by the following steps: during loop shaping process, a PID controller is designed by using a nominal loop transmission function represented on Nichols chart. Then, the frequency response of closed-loop transfer function is used for designing a prefilter. It is validated that the proposed QFT-based AFR control algorithm successfully satisfy the requirements through experiments of various engine operating points.

• 마이크로전자및패키징학회지
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• 제11권1호
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• pp.1-6
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• 2004

자동차 전장품의 시험환경 조건이 엄격해짐에 따라, 전장품 개발 기술자들은 이에 부합하는 성능, 신뢰성, 비용 등을 고려한 보다 효과적인 제품 설계를 위해 노력하고 있다. 본 논문에서는 ECM 알루미나 기판의 플라즈마 세척 영향과 리플로우 후 Sn-37wt%Pb 솔더와 패드 접합부 계면에서 형성되는 금속간 화합물을 관찰하였다. 기판의 플라즈마 세척은 계면 접착력을 저해하였던 C에 의한 유기 잔류물 층이 제거되어 계면 접착력을 향상시키는 효과가 있다. 또한 AFM 분석 결과 도체 패드의 표면 거칠기는 304 nm에서 330 m로 증가하였다. 리플로우 과정에서 솔더와 TiWN/Cu 패드 계면에서 형성된 $Cu_6/Sn_5$는 리플로우 횟수가 증가할 수록 결정립의 크기도 조대화되었다. 솔더와 Ag-Pd 도체패드 계면에서는 세포질 형태의 $Ag_3Sn$화합물이 관찰되었다. $Ag_3Sn$은 지름이 약 0.1∼0.6 $\mu\textrm{m}$이며, 솔더 내부에서는 침상 모양도 관찰되었다.

• Journal of Korea Trade
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• 제23권6호
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• pp.1-13
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• 2019

Purpose - This study deals with a strategic plan for meeting the value added criteria effectively, which is one of the methods of determining origin used in preferential trade such as FTA. Automobile products, one of the major Korean export items, were selected to give a practical use against the FTA requirements. Design/methodology - This study is based on the value-added criteria of the Korea-US and Korea-EU FTAs that apply various value-added criteria. The Korea-US FTA adopts the RVC method based on the integration, deduction and net cost methods, while the MC method is employed in the Korea-EU FTA. The methodology used in this work is an extended literature review, analysis of the value-added criteria applied to automobile products under Korea-US and Korea-EU FTA with some secondary statistics. Findings - Based on in - depth analysis of the value - added criteria requirements for automobile products stipulated in the Korea - US FTA and the Korea - EU FTA, two strategic considerations are suggested. First is 'appropriate value-added strategy' and the second is 'strategy of changing production and trade structure'. The second strategy is a bit used in Korea but this is not considered best if the first strategy is ignored or forgotten. The second one is meaningful when this becomes inevitable. Research limitations/implications - This study is primarily designed to assist Korean auto mobile industry players exporting to EU and USA but this may help to auto part or material producers in FTA counter party territories being EU or USA as the preferential tariffs are applied on a inter region basis. A further research other than auto mobiles using other major FTAs might be followed later. Originality/value - There has been so far little research on strategic factors to meet the value-added origin requirements. This study, therefore, is expected to contribute facilitating the decision of FTA origin and to improve the utilization of FTA by allowing exporting companies using value added criterion to more smoothly meet origin requirements. This will also enable the tax authorities to utilize the value-added criterion to validate effectively the origin of imports where preferential tariffs are applied.