• 한국안전학회지
• /
• 제12권4호
• /
• pp.15-20
• /
• 1997

This study is to investigate the behavior of fatigue crack growth with ATOS 55 steel which can be applied to the commercial car Dump Frame. It is to obtain the material coefficients after tensile and fatigue crack growth test with the variation of thickness or heat treatment. Also, that is proved the Pari's law by experiment. The summarized results are as follows ; 1) Increasing thickness, tensile and yield strength measured highly regardless to heat treatment and measured lowly as variation of heat treatment temperature. 2) Specimen of thickness 8.0㎜ measured the faster of crack growth rate than another thickness according to the results of experiment. It was the different of stress conditions in crack tip. 3) It was found that the experimental constant m was range of 2∼5 to the relationship between fatigue crack growth rate and stress intensity factor range. Also, it was to prove the Paris's law by the experiment.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2004년도 추계학술대회 논문집
• /
• pp.1461-1466
• /
• 2004

Recently Domestic EMU's on board signal systems are gradually changed form Cab signal(Fix Block) to Distance-to-go. Interfaces with on board signal system, TCMS Redundancy structure is mainly required. This paper suggest Manaul/Automatic Driving based on TCMS-ATC interface and design of backup system which is operated by Stan-by Computer when one of it's Local Interface Unit(LIU) is out of oder. For the purpose of Precision Train Stop, Distance-to-go signal system require accuracy speed. Free-axle structure is required for this system This paper suggest Free-axle braking system that lack of brake-force is compensated by the distributed brake-force using TCMS. And one of braking system has out of order, compensation of brake-force for Free-axle system. Then we prove our design to Complete Car Test

• 한국해양공학회지
• /
• 제13권2호통권32호
• /
• pp.18-25
• /
• 1999

Western coastal ports of Korea experience severe tidal range with up to 9.7 meter between high and low tides. The significant water level variation implicates many operational difficulties during loading and un-loading from cargo ships. To overcome problems due to tide and to secure the continuous loading operation, a new loading system for container cargo called "container pallet system" is developed and introduced in the paper. Three types of structure forms, offshore structural deck, double bottom structural form and the mixed form, are inverstigated with MSC/NASTRAN software. The results prove that the mixed type structure with truss enforcement is found to be the most appropriate for the region.

• 한국자동차공학회논문집
• /
• 제11권4호
• /
• pp.204-210
• /
• 2003

A PC-based analysis and design system of exhaust muffler is described. It makes use of software packages such as Sysnoise and STAR-CD to calculate transmission loss(TL) and back pressure. The system is applied to redesign a main muffler of passenger car to improve its performance. The effects of design parameters on acoustic and pressure loss characteristics are examined. Taguchi method Is used to determine optimal combination of parameters which affects muffler performances such as TL and back pressure. Three models are chosen and compared in laboratory bench test and engine dynamometer test to prove their performances.

• 한국조경학회지
• /
• 제19권2호
• /
• pp.12-22
• /
• 1991

The purpose of this study is to identify demand and methods of projection, including to prove the variables affecting the fluctuation of visitors and to analyze the relationship between these variables in National Park. Statistical analysis method (Multiple Linear Regression Analysis, ANOVA, and Model diagnostics) was carried out by computer program SAS/pc. 13 variables (1. Total Population, 2. Per Capita PDI, 3. Employment Ratio of S.O.C. & others, 4. NO. of Passenger Car, 5. Length of Roads, 6. Leisure Expenditure of Farm Household, 7. Leisure Expenditure of Urban Household, 8. Price Index, 9. NO. of Bus, 10. Exchange on Dollars, 11. Export, 12. Import, and 13. Visitors in National Park) had been used to this study. The scope of time period is during the last 17 years (1970-1986). The results were as follows; 1) Participation depends only on the specific characteristics of the economic factors (Price Index and Leisure Expenditure of Urban Household). These factors are the importance factors directly affecting the participation of visitors. The statistical Model for projecting the visitors in National Parks is the function of "Visitors in National Parks (thousand)=14915+0.210311*Leisure Expenditure of Urband Household (won)-157.835619*Price Index(1985=100)" 2) The external factors affecting the participation depends upon the interelated features of availability and accessibility (NO. of Passenger Car, Length of Roads, and NO. of Bus) of recreation resources or sites, and the economic factors (Per Capita PDI, Export, and Import). These factors are the factors indirectly affecting the participation of visitors. 3) The participation depends on the specific characteristics of demographic factors (Total Population and Employment Ratio of S.O.C. & others). These factors are the factors indirectly affecting the participation of visitors. 4) The unexpected fluctuation of yearly visitors depends on oil shock or inflation (1971, 1973-1974, 1979-1980), promulgation of national emergency decrees (1971-1972, 1974-1975, 1979-1980), and national events (assassination of president Park's wife, Madame Yuk in 1974 and president Park I 1979).

• 대한기계학회논문집A
• /
• 제24권4호
• /
• pp.926-936
• /
• 2000

Actual and strict definition of the shift quality for the powertrain system equipped an automatic transmission must be understood through the acceleration change of the vehicle body, which the driver directly feels as a shift shock. For this reason, it is necessary to concurrently analyze the characteristics of the powertrain system and the vehicle body. This paper presents the mathematical model of the vehicle body, which is based on the equivalent lumped system, to append to the developed model of the powertrain system. The concept of tire slip is also introduced for the experimental relationship between tire/road and driving force. Using the developed dynamic simulation programs, shift transients characteristics are analyzed. Theoretical results are compared with experimental ones from real car tests in equal conditions in order to prove the validity of presented model. In these tests, the system to measure the vehicle acceleration is used with various speeds and engine throttle sensors. It is expected that the presented modeling techniques can provide good predictions of the vehicle driving comfortability.

• 한국HCI학회:학술대회논문집
• /
• 한국HCI학회 2008년도 학술대회 1부
• /
• pp.205-209
• /
• 2008

최근 하드웨어의 발달로 영상처리를 사용한 운전자 보조 기능의 차선인식 시스템이 상용화 되고 있다. 하지만 고속도로 주행과 같은 차선이 확실하고 곡률이 완만한 비교적 이상적인 상황에서의 차선인식을 전제로 만들어진 시스템이 많아 시내도로와 같이 상대적으로 곡률이 크고 일부 차선이 확실치 않은 장소에서는 차선인식이 힘들어 무인 자동차 제어에는 적용하기 힘들다. 본 논문은 무인차량의 자동주행을 위해 labeling과 차선예측을 통해 급격한 곡선 차로나 차선이 한쪽만 그려져 있는 경우에도 강인하게 차선인식이 가능한 시스템을 제안한다. 제안된 방법을 이용하여 이상적인 경우가 아닌 급격한 곡선차로가 있거나, 차선이 한쪽만 있는 실제 환경의 경우에서도 차선인식이 가능함을 보였다.

• 한국컴퓨터산업학회논문지
• /
• 제5권9호
• /
• pp.1005-1016
• /
• 2004

기존 교통신호등은 최적 교통신호주기기능을 상실했다. 기존 교통신호주기는 현시 교통주기와 30% -45% 가 일치하지 않고 있다. 본 논문에서는 평균 주행속도를 개선하고 평균 승용차 대기시간을 단축하기위해서 전자 교통신호등을 본 논문에서 제안한다. 본 논문에서는 실제 교통상황의 교통량, 출발 지연시간, 자동차속도 등의 40가지 센서 입력조건들을 저장하는 방법을 연구 중이다. 지능형 퍼지 기법을 이용하면, 서로 다른 10개의 교차로에 서 최 적의 녹색시간을 예측할 수 있다. 컴퓨터 모의실험 결과, 자동차 길이를 고려하지 않은 기존 교통신호등보다 . 오프셋 및 평균 자동차 대기시간을 줄일 수 있음이 입증되었다.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제49권6호
• /
• pp.299-306
• /
• 2000

The primary cause of air pollution by vehicles is imperfect combustion of fuel. One of the most usual causes of this imperfect combustion is the misfire in IC(Intenal Combustion) engine. Recently it is obligated for an ECU to monitor the emission level and warn the driver in case of exceeding specified emission standards. Therefore, in order to comply with this OBD-II regulations, car makers are investing a considerable amount into technology which would enable the detection of misfire and the particular cylinder in which misfire is taking place. So far, it has been able to detect misfire using engine speed, which can be obtained crank angle. However, such a method posed a problem in analyzing at high speed and in recognizing the misfire from the load impact at bumpy road. In this paper, misfire detection is made possible by simple arithmetic using WDFT, especially at high engine speed. In addition, the moving window method of a Walsh function is applied to determine the cylinders under misfire in case of multiple misfires. An actual experiment was conducted to prove that WDFT is applicable to effective in computation speed and to same result in misfire detection and cylinder determination at idle, part load and bumpy road conditions.

• 제어로봇시스템학회논문지
• /
• 제7권6호
• /
• pp.523-531
• /
• 2001

This paper describes and automatic mirror adjustment system that rotates a pair of side mirrors and the room mirror of a car to the optimal position for a driver by using the locating of the driver\`s pupils. A stereo vision system measures 3D coordinates of a pair pupils by analyzing the input images of stereo B/W CCD cameras mounted on the instrument panel. this system determines the position angle of each mir-ror on the basis of information about the location of the pupils and rotates each mirror to the appropriate po-sition by mirror actuators. The vision system can detect the driver\`s pupils regardless of whether it is day-time or nighttime by virtue of an infrared light source. information about the pair of nostrils in used to im- prove the correctness of pupil detection. This system can adjust side mirrors and the room mirror automati- cally and rapidly by a simple interface regardless of driver replacement of driver\`s posture. Experiment has shown this to be a new mirror adjustment system that can make up for the weak points of previous mirror adjustment systems.