• Journal of the korean Society of Automotive Engineers
• /
• v.8 no.4
• /
• pp.24-35
• /
• 1986

현재 주요 가스상물질은 미국의 경우 규제전보다 일산화탄소가 96%, 탄화수소 96%, 질소산화물 76%가 개선되어 어느정도 안정단계에 들어 갔다고 볼 수 있다. 그러나, 입자상물질규제는 디이 젤자동차의 증가와 더불어 1986-1994기간동안 대폭적으로 강화되고 있다. 그러나 자동차 배출 가스중에는 수백가지의 화학물질이 존재하고 인체에 유독한 물질은 규제물질외에도 엄청나게 많다. 따라서 1977년 8월에 개정된 미국의 대기정정법(CAA, clean air act)에는 "신규 제작자동 차나 엔진에 사용되는 어떠한 방지장치, 시스템 또는 부품도 공중보건, 복지 및 안전에 부당한 위험을 일으키거나 일으키는 요인이 될 수 없다"(참조, CAA 202 (a) 및 CFR 86.084-5)고 규 정하고 있다. 이에 따라 미국환경청에서는 회람 등을 통하여 가능한 독성물질에 대하여 경우에 따라 측정할 것을 요구하고 있다. 국내 환경보전법에도 자동차연료첨가제 사용할 때 현저하게 유해한 물질이 배출된다고 인정하는 때에는 그 사용을 규제할 수 있게 되어있고 새로 제정될 자동차 배출가스 시험검사방법 및 절차에 관한 규정에 이에 관한 사항을 추가할 움직임이 있다. 물론 미규제물질의 규제하는 인체에 대한 피해정도나 측정방법 등의 여러 가지 문제가 수반되나 장기적인 국민보건과 환경보전 측면에서 신중하게 다루어져야 되리라 봐서 여러 가지 오염물질의 현황이나 분석방법 등에 대하여 기술코자 한다.여 기술코자 한다.

• Journal of the korean Society of Automotive Engineers
• /
• v.1 no.1
• /
• pp.21-24
• /
• 1979

오늘날 자동차배기의 대기오염공해는 큰 사회문제가 되었으며 선진제국은 이미 오래전부터 배 기정화를 시작하여 상당한 성과를 거두고 있으나 우리나라는 지금이 시작이 아닌가 생각된다. 배기정화는 자동차관계자가 해결해야 할 가장 큰 과제의 하나일 것이다. 자동차의 원동기로서 피스톤식 내연기관을 사용하는 한 최종적으로는 어떠하든 간에 배기처리를 할 필요가 있다. 따 라서 배기처리방법의 성공의 여부는 자동차용 내연기관의 운명이 걸려있다고도 할 수 있다. 이 러한 시점에 있어서 다른 사람 등이 해온 배기처리방법을 고찰해 보는 것도 결코 무의미한 것이 아니라 생각되기에 저자는 약 10년전에 발족한 일본자동차연구소 (JARI : JAPAN AUTOMOBILE RESEARCH INSTITUTE) 에서 시험제작을 하여 중점적으로 배기정화의 연 구를 해온 배기의 완전무해화장치 (JAPECS;JARI Perfect Emission Control System)를 소개하고 이것에 대한 고찰을 하고자 한다. JAPECS의 시험제작연구의 목적은 단지 자동차배기의 완전 무해화장치의 시험제작에 있는 것이 아니고 이 연구를 추진함으로써 1) 내연기관의 배기정화의 궁극적인 가능성을 추구할 수 있는 것과 2) 각 단계의 배기규제에 대처할 수 있는 가장 효과적이고 실용적인 배기처리장치의 개발을 위한 기술적인 검토가 될 수 있는 것으로 되어있다. 이 JAPECS project에서는 현재 사용되고 있는 모든 종류의 자동차엔진의 배기정화를 목표로 하고 있고 최초의 2년은 기초적인 검토에 중점을 두고 그후는 실용화에 중점을 두고 있다.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.21 no.1
• /
• pp.68-77
• /
• 2013

This paper presents AUTOSAR-ready light software architecture (AUTOSAR-Lite), which is a light weighted version of the AUTOSAR, for automotive embedded control systems. The proposed AUTOSAR-Lite reduces overhead problems caused by the excessive standard specifications of AUTOSAR. Concurrently, AUTOSAR-Lite keeps advantages of AUTOSAR such as a scalability, re-usability, reliability, and transferability. The fundamental design of AUTOSAR-Lite is originated from the AUTOSAR standard. AUTOSAR-Lite is composed of three layers such as an application software, runtime environment, and basic software layer. The application software layer adopts component-based design methodology as AUTOSAR. The runtime environment layer integrates interfaces between application and basic software layers. In case of the basic software layer, restrictions of the module configurations and interfaces of basic software are minimized. In order to validate the feasibility of AUTOSAR-Lite, a software design result based on AUTOSAR-Lite software architecture for electronic throttle control (ETC) system is suggested.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.8 no.6
• /
• pp.543-550
• /
• 2003

Thin paper proposes a new three-phase rectifier that actively shapes the input current sinusoidal by means of two rectifier bridges, each followed by a dc-dc boost converter. The proposed approach draws sinusoidal input current at unity power factor and has output voltage regulation capability The size and weight of magnetic material Is reduced by Incorporating a low KVA three-phase autotransformer and by directly connecting the dc outputs each other without using low frequency interphase transformer(IPT). The operation principle is described along with simple control method, and experimental results on a 1.5KW prototype are provided.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.31 no.1
• /
• pp.49-57
• /
• 2003

The flight trajectory of a boomerang is predicted with the momentum theory (actuating disk theory) and the blade element method generally used as tools to analyze in the rotary-wing aerodynamics. Boomerangs made by students are actually compared with the computational results, utilized to get the physical intuition. The transition from helicopter mode to autogyro mode with the gyroscopic precession is observed in numerical analysis and experiment like a 'flying rotor' after the boomerang taking off. The whole system is shown to be highly nonlinear and very sensitive to the initial conditions. Various flight loci may be obtained if we change the parameters.

• Journal of Korea Society of Industrial Information Systems
• /
• v.24 no.1
• /
• pp.23-30
• /
• 2019

As deep learning with the network-based algorithms evolve, artificial intelligence is rapidly growing around the world. Among them, finance is expected to be the field where artificial intelligence is most used, and many studies have been done recently. The existing financial strategy using deep-run is vulnerable to volatility because it focuses on stock price forecasts for a single stock. Therefore, this study proposes to construct ETF products constructed through portfolio methods by calculating the stocks constituting funds by using deep learning. We analyze the performance of the proposed model in the KOSPI 100 index. Experimental results showed that the proposed model showed improved results in terms of returns or volatility.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.12 no.3
• /
• pp.87-94
• /
• 2002

This study presents an MSB(Most Significant Bit) Int multiplier using cellular automata, along with a new MSB first multiplication algorithm over GF($2^m$). The proposed architecture has the advantage of high regularity and a reduced latency based on combining the characteristics of a PBCA(Periodic Boundary Cellular Automata) and with the property of irreducible AOP(All One Polynomial). The proposed multiplier can be used in the effectual hardware design of exponentiation architecture for public-key cryptosystem.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.25 no.3
• /
• pp.275-284
• /
• 2022

Linear Shaped Charge(LSC) is widely used as a separation system in the field of weapon system. However, there are some disadvantages that are charging lots of explosives due to lack of uniformity and having difficulties of the design of liner and explosives because of manufacturing process. In order to solve these problems, Precision Linear Shaped Charge(PLSC) that can design a liner independently and charge explosives uniformly has been developed. In this study, PLSC was designed to have a proper liner shape and amount of explosives, and the penetration test of PLSC with different stand-off distance from liner to target was conducted. On the basis of the penetration test results of PLSC, the numerical analysis method using AUTODYN was established and verified. The penetrative mechanism and characteristics of PLSC with targets of different materials was analyzed from experimental and numerical results.

• Journal of the Semiconductor & Display Technology
• /
• v.21 no.4
• /
• pp.59-64
• /
• 2022

Vibration is one of the factors that degrades the performance of equipment and measurement equipment used in high-tech industries such as semiconductors and display. The vibration isolator is classified into passive type and active type. The passive vibration isolator has the weakness of insufficient vibration isolation performance in the low frequency band, so an active vibration control system that can overcome these problems is used recently. In this paper, PID controller is used to control the active vibration isolator. Methods for setting the gain of the PID controller include the Zeigler-Nichols method, the pole placement method. These methods have the disadvantage of requiring a lot of time or knowing the system model accurately. This paper proposes the gain auto tuning method of the active vibration isolator applied with the PSO algorithm, which is an optimization algorithm that is easy to implement and has stable convergence performance with low calculations. It is expected that it will be possible to improve vibration isolation performance and reduce the time required for gain tuning by applying the proposed PSO algorithm to the active vibration isolator.

• Journal of the Korean Society of Industry Convergence
• /
• v.26 no.5
• /
• pp.743-750
• /
• 2023

Aluminum alloy is a material widely used in the aircraft industry. However, since it has relatively low hardness, strength and tribological properties, it is necessary to improve these properties. In this paper, a TiN thin film was coated on the surface of AL7075-T7351 using DC magnetron sputtering. The coating was performed by setting different deposition pressure, deposition time, and applied power. Then, the tribological properties of the thin film were investigated. As a result of the experiment, the hardness of the thin film was higher than that of the base material, and the specimen with the highest hardness had excellent friction coefficient, wear amount, and adhesive strength characteristics. Through this study, it was confirmed that the tribological characteristics of aluminum alloy can be improved by depositing thin films using DC magnetron sputtering.