• Journal of the Korean Society of Industry Convergence
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• v.26 no.5
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• pp.915-923
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• 2023

As environmental regulations on carbon emissions are strengthened worldwide, the existing internal combustion engine-centered automobile industry is being reformed. In particular, large buses and large cargo trucks are pointed out as one of the main causes of environmental destruction due to excessive carbon emissions. The E-Highway power collection system, which has recently been proposed as a solution, uses the vehicle's battery as a backup power source or regenerative braking, depending on whether the pan head of the pentograph installed in the vehicle is in contact with the overhead line. It is used to store the excess energy generated. However, wear through contact due to continuous contact reduces the current collection effect and causes failure. In this paper, by using the current difference, the horizontal position information of the panhead in contact with the overhead line is acquired, thereby reducing the abrasion of the conductor and the panhead Make it possible to follow the overhead line. The position estimation method proposed in this paper simply configures a device that can detect the position of the overhead line of the pantograph by the difference in resistance. It is economical and has the advantage of reducing the volume. The characteristics of the pantograph estimating the location of overhead lines were analyzed using the difference between the two currents of the current collector, the feasibility of the positioning estimation system was verified through simulations and experiments.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.5
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• pp.92-107
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• 2023

Recently, along with the continuous increase in the supply of electric vehicles, electric vehicle fire accidents are also showing a rapidly increasing trend. Electric vehicle fires last for a long time compared to fires in internal combustion engine vehicles and have problems with the risk of secondary explosions and the generation of large amounts of smoke. In particular, electric vehicle fires in underground roads, which are semi-enclosed spaces, may amplify the problems of existing electric vehicle fires. On the other hand, there are no domestic response guidelines for electric vehicle fires occurring inside underground roads. Therefore, an awareness of fire accidents was confirmed through a survey of the general public, and electric vehicle fire characteristics and primary considerations were derived from stakeholders related to electric vehicle fires in underpasses. Through this, the guidelines for responding to electric vehicle fires on underground roads were established.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.05a
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• pp.111-112
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• 2009

Diamond-like carbon (DLC) is a convenient term to indicate the compositions of the various forms of amorphous carbon (a-C), tetrahedral amorphous carbon (ta-C), hydrogenated amorphous carbon and tetrahedral amorphous carbon (a-C:H and ta-C:H). The a-C film with disordered graphitic ordering, such as soot, chars, glassy carbon, and evaporated a-C, is shown in the lower left hand corner. If the fraction of sp3 bonding reaches a high degree, such an a-C is denoted as tetrahedral amorphous carbon (ta-C), in order to distinguish it from sp2 a-C [2]. Two hydrocarbon polymers, that is, polyethylene (CH2)n and polyacetylene (CH)n, define the limits of the triangle in the right hand corner beyond which interconnecting C-C networks do not form, and only strait-chain molecules are formed. The DLC films, i.e. a-C, ta-C, a-C:H and ta-C:H, have some extreme properties similar to diamond, such as hardness, elastic modulus and chemical inertness. These films are great advantages for many applications. One of the most important applications of the carbon-based films is the coating for magnetic hard disk recording. The second successful application is wear protective and antireflective films for IR windows. The third application is wear protection of bearings and sliding friction parts. The fourth is precision gages for the automotive industry. Recently, exciting ongoing study [1] tries to deposit a carbon-based protective film on engine parts (e.g. engine cylinders and pistons) taking into account not only low friction and wear, but also self lubricating properties. Reduction of the oil consumption is expected. Currently, for an additional application field, the carbon-based films are extensively studied as excellent candidates for biocompatible films on biomedical implants. The carbon-based films consist of carbon, hydrogen and nitrogen, which are biologically harmless as well as the main elements of human body. Some in vitro and limited in vivo studies on the biological effects of carbon-based films have been studied [$2{\sim}5$].The carbon-based films have great potentials in many fields. However, a few technological issues for carbon-based film are still needed to be studied to improve the applicability. Aisenberg and Chabot [3] firstly prepared an amorphous carbon film on substrates remained at room temperature using a beam of carbon ions produced using argon plasma. Spencer et al. [4] had subsequently developed this field. Many deposition techniques for DLC films have been developed to increase the fraction of sp3 bonding in the films. The a-C films have been prepared by a variety of deposition methods such as ion plating, DC or RF sputtering, RF or DC plasma enhanced chemical vapor deposition (PECVD), electron cyclotron resonance chemical vapor deposition (ECR-CVD), ion implantation, ablation, pulsed laser deposition and cathodic arc deposition, from a variety of carbon target or gaseous sources materials [5]. Sputtering is the most common deposition method for a-C film. Deposited films by these plasma methods, such as plasma enhanced chemical vapor deposition (PECVD) [6], are ranged into the interior of the triangle. Application fields of DLC films investigated from papers. Many papers purposed to apply for tribology due to the carbon-based films of low friction and wear resistance. Figure 1 shows the percentage of DLC research interest for application field. The biggest portion is tribology field. It is occupied 57%. Second, biomedical field hold 14%. Nowadays, biomedical field is took notice in many countries and significantly increased the research papers. DLC films actually applied to many industries in 2005 as shown figure 2. The most applied fields are mold and machinery industries. It took over 50%. The automobile industry is more and more increase application parts. In the near future, automobile industry is expected a big market for DLC coating. Figure 1 Research interests of carbon-based filmsFigure 2 Demand ratio of DLC coating for industry in 2005. In this presentation, I will introduce a trend of carbon-based coating research and applications.

• Korean Journal of Construction Engineering and Management
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• v.9 no.2
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• pp.99-107
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• 2008

Rapidly increasing automobile supply rate according to improved economic level of life makes lack of parking space of apartments. Even though the initial design of parking space compiled with old regulations, it may not observe either new laws or requirement of inhabitants. Even if old apartments have no structural durability problem, outworn facilities and insufficient parking area may be a main reason for reconstruction. It causes waste of national resources and makes recycling issues. Additionally, irregularly parked cars make traffic obstruction to a fire engine and result in many fire accident victims. Parking problems of apartments are not only inconvenience but also serious safety issues. From these points of view, remodeling only for parking area expansion is necessary to avoid overall reconstruction of apartments. The purpose of this study is to suggest a retaining wall selection method for apartments underground parking lots expansion without evacuation of resident people. Effect factors to select retaining wall system are analyzed and weight values are calculated by applying AHP. One selection method of retaining wall is proposed by evaluating applicability and its sensitivity analysis is executed. This selection method is expected to help decision-making of retaining wall system selection.

• 대한공업교육학회지
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• v.32 no.1
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• pp.33-54
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• 2007

The purpose of this study was to verify the effects of cooperative learning on academic achievement of the maintenance of intake and exhaust stroke education in the technical high school. The following null hypotheses were stated and utilized for the purpose of the study. (1) Taxonomy of educational objectives(cognitive, affective and psychomotor domain) and (2) the level of entering behavior To verify the hypotheses of the study, 2 parts(17 students in each part) of the second grades from technical high school were selected. The data were collected and interpreted statistically by t-test using SPSS(ver. 10) at the .05 level of significance. The result of this study were as follows; First, learning together cooperative learning had little effect on the academic achievement in the cognitive domain but the affective and psychomotor domain were more effective than the traditional teaching method on the taxonomy of educational objectives. Second, learning together cooperative learning was effective on the academic achievements of lower and higher ability group of students, while wasn't effective on middle ability group in the level of entering behavior.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.6
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• pp.1292-1305
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• 2013

Along with the strengthening vehicle environmental regulations and the growing needs for the energy consumption reduction technology, the researches on the engine idle stop system, have been briskly carried out around the automobile manufacturers before the development of alternative energy. Furthermore, there is a movement to disseminate the environment friendly idle stop system by combining the system to the generalized smart key system to not only increase purchasing but also provide the convenience and save the energy as well. In this paper, we designed and implemented the idle stop system algorithm for the aftermarket smart key system with the OBD-II interface. The implemented start stop system is capable of controlling two independent systems, the smart key system and intelligent idle stop system, on a single ECU. In addition, the implemented start stop system standardizes the communication interface with the vehicles to reduce the time required for installing the start stop system to the various vehicles, and satisfies every standard response time limit for the vehicle status request signals.

• Journal of the Korean Applied Science and Technology
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• v.33 no.4
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• pp.824-835
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• 2016

Although the number of registered cars in South Korea is above 21million and one family has about 1.07 cars, there is no national standard for automobile reference fuel in South Korea. Reference fuel is the fuel used for certificating vehicle performance, emissions and fuel economy. Now, domestic market fuels are used as reference fuel. However, the quality of domestic market fuel is constantly changing by seasonal and fuel manufacturers. It may effect vehicle performance, emissions and fuel efficiency test result. On this study, market fuel quality was monitored and reference fuel standard(draft) was set by reflecting market fuel monitoring result. Reference fuel standard(draft) was applied to GDI and MPI engine. As a result, the difference of fuel economy between fuels meeting the reference fuel standards(draft) was reduced to 1.1% while the difference of fuel economy between market fuels was 3.8%.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.5 no.4
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• pp.83-93
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• 1994

1886년 고트리브 다이믈러와 칼 벤즈가 가솔린 자동차를 개발한 이후 100여년이 지난 지금 자동차는 비약적으로 진보, 발전하여 현대 산업사회와 개인의 생활에 있어 산업운송수단과 이동수단으 로서 필요불가결하게 되어 밀접한 관계를 갖고 있다. 우리나라 자동차 공업의 역사는 자동차가 사회적, 경제적 효용에 따라 그 생산과 보유대수가 날이 갈수록 증가 일로에 있으며, 자동차의 생산대수는 전세 계에서 년간 약 50,606천대('94년)로서 중요한 국가 기간 산업으로 자리하고 있다. 한편 전기, 전자공업의 발전에 따른 자동차의 Car Electronics가 많이 채용되게 됨에 따라 현재의 자 동차에는 대부분이 전자제어 System으로 구성되어 있다. 최근에는 Micro Processor를 이용한 전자부품이 많이 사용되어 전자파에 대한 문제가 다양하게 발생 하고 있다. 예를 들면 미국 캘리포니아주에서 전자점화제어장치와 연료분사 장치를 설치한 구미의 자동 차가 주행중 28MHz, 28W의 아마추어 무선을 탑제한 자동차가 통과할 때 엔진이 고르지 못한 보고가 있 었고, 화학섬유로된 옷을 착용한 전자부품이 다른 부품에 영향을 주는 사례가 맣아지고 있다. 따라서 자동차에는 여러가지의 전장품, 전자기기를 탑재하기 때문에 자동차 자체에서 발생하는 것과 외부로 부터 받는 전자장해 EMI(Electromagnetic Interference), EMS(Electromagnetic Susceptibility) 가 문제로 되어 자동차 및 부품 maker에 의한 EMC(Electromagnetic Compatibility) 평가의 중요성이 고조되고 있다. 차제무전기, 차제무전기, Car-Radio는잡음방해를 많이 받기도 하지만, 잡음원이 되기 도 한다. 또한 Engine 제어, 차속제어, Brake 제어등에 이용되는 전자제품은 방해에 의한 오동작 또는 파괴가 발생하여 주행기능, 안전성에 문제가 야기되지 않도록 해야 한다. 이러한 전자기 환경은 모두 RF(Radio Frequence)와 자동차에서의 전자파 장해 문제의 원이 될 수 있다. 자동차 및 그 부품의 전자기 방해에 관한 규격화는 1987년부터 괄목할 만하게 진행되어 이에 따른 규제 움직임이 IEC(International Electrotechnical Commission: 국제전기기술위원회) 산하의 하부기 구인 CISPR(International Special Committeeon Radio Interference: 국제 무선 장해 특별위원회)가 전자기 방해파에 대한 측정법 통일안을 제안 하였고, ISO(International Standardization Organiza- tion: 국제표준화 기구) 가운데 TC 22/SC3가 자동차의 전장품에 대한 장해를 논의히고 있다. 특히, 자동차의 EMC에 관한 국가 규격은 국제 규격에서 저술한 바와 같이 특별히 규정된 것이 없고 VDE(Verband Deutscher Elektrotechniker: 서독전기기술 협회)와 SAE(Society of Automotive Engi- neers: 자동차 기술자 협회)에서 비교적 활발하고 Jaso(Japanese Automobile Standards Organization: 일본 자동차 표준협회)에서 많이 진행중에 있다. 본 고에서는 자동차의 전자제어에 따른 잡음 발생 요인과 전자파 간섭 관련 자동차 규격과 시험평가 방법에 대해 간단히 소개 하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.570-575
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• 2019

Active muffler is implemented by applying active noise control technique to reduce exhaust noise of automobile muffler. Conventional Filtered_x LMS algorithm has a problem that the degree of control filter becomes very large and convergence deteriorates when acoustic feedback is present. The recursive LMS algorithm can compensate for this problem because it can be easily diverted in the adaptive filter adaptation process. In this paper, the structure of the primary path and the secondary path transfer function is designed as the IIR filter to improve the convergence performance and the computational burden, and the stabilization filter algorithm is applied to secure stability which is a disadvantage of the IIR filter structure. The stabilization filter algorithm plays a role of pulling the pole into the unit circle to prevent the pole of the transfer function corresponding to the acoustic feedback from diverging during the adaptation process. In this way, the computational burden of the active muffler system and the convergence performance can be improved. In order to show the usefulness of the proposed system, we compared the performance of the proposed Filtered_x LMS algorithm with the performance of the proposed system for the exhaust sound of a diesel engine, which is a variable environment. Compared to conventional algorithm, proposed algorithm's computational burden is less than half, and convergence performances are more than 4 times.

• Journal of Digital Convergence
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• v.17 no.11
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• pp.207-213
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• 2019

The fuel-cut coast-down driving mode is activated when the acceleration pedal is released with transmission gear engaged, and it's a default function for electronic-controlled engine of vehicles. The fuel economy becomes better because fuel injection stops during fuel-cut driving mode. A fuel-cut detection method is suggested in the study and it's based on the speed, acceleration and road gradient data from GPS sensor. It detects fuel-cut driving mode by comparing calculated acceleration and realtime acceleration value. The one is estimated with driving resistance in the condition of fuel-cut driving and the other is from GPS sensor. The detection accuracy is about 80% when the method is verified with road driving data. The result is estimated with 9,600 data set of vehicle speed, acceleration, fuel consumption and road gradient from test driving on the road of 12km during 16 minutes, and the road slope is rather high. It's easy to detect fuel-cut without injector signal obtained by connecting wire. The detection error is from the fact that the variation range of speed, acceleration and road gradient data, used for road resistance force, is larger than the value of fuel consumption data.