• 한국경영과학회지
• /
• 제21권2호
• /
• pp.95-109
• /
• 1996

In automobile industry, the depot (distribution center) system is utilized to adjust the inventory and to supply the demands to the firm timely. In case of the small lot demands of short delivery cycle and the long distance from the parts manufacturing to the firm, the depot system is very important. In this paper, a model to minimize the sum of costs of holding, inventory and transportation, is proposed to determine the optimal quantities of production and transportation in JTT system. Finally, computational results that verify the effectiveness of the proposed model are demonstrated.

• 한국자동차공학회논문집
• /
• 제11권6호
• /
• pp.80-85
• /
• 2003

In the present paper, dynamics analyses of pressure control characteristics have been performed in a variable pressure solenoid valve. A number of solenoid valves have been used in the electronic control system, especially automatic transmission of an automobile. Variable pressure solenoid valve is intended to produce spatial movement by the electrical signal. Dynamics analyses of pressure control characteristics have been practiced by the Finite Difference Method, which show the pressure distribution in the solenoid valve. The results of numerical analyses show the dependence of pressure distribution on the displacement of the spool in the solenoid valve, and then, are compared with the experimental results.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2003년도 추계학술대회
• /
• pp.199-204
• /
• 2003

In the present study, the compression process in scroll compressor was simulated in consideration of flow leakage and heat transfer. Tangential and radial leakages of the refrigerant between the scrolls were considered as nozzle flow. The experiment was first conducted with a scroll compressor for automobile air conditioning system and R134a as a refrigerant. Temperature and pressure were measured at the suction and discharge ports of the compressor to determine the thermodynamic states of the refrigerant flow. Temperature distribution of the scroll with the involute angle was also measured by thermocouples that were installed inside the scroll. Measured temperature distribution was compared with the numerical results. From this result, the thermal effect of mechanical contact was found to be important in heat transfer of the compression process.

• 한국수소및신에너지학회논문집
• /
• 제28권6호
• /
• pp.704-711
• /
• 2017

Korea, which has a high dependency on energy imports, is greatly affected by fluctuations in international oil prices. In order to offset these effects, various policies such as 'diversification of energy sources' and 'energy mix' are being pursued. Renewable Fuel Standard (RFS) is a policy promoted for this purpose, and a compulsory mixing system is applied only to the diesel. In order to reduce dependence on fossil fuels in various countries, they are concentrating on the dissemination of bio-alcohol as well as bio-diesel, and commercialization through various verification. In this study, evaluation of domestic materials and vehicles was carried out to promote domestic bio alcohol fuel. We analyzed the fuel characteristics of domestic quality standard items by mixing them with gasoline of automobile at a certain mixing ratio (0%, 3%, 6%, and 10%).

• 한국기계가공학회지
• /
• 제17권6호
• /
• pp.117-123
• /
• 2018

Automotive headlamps have been continuously developed as one of the most important devices for securing the driver's view, and the LED lamps are getting popular in recent years. However, in case of the LED lamps, because the heat generated by the LED lamps are too high, it shorten the product life and lower the LED efficiency. Therefore, this study was investigated the cooling characteristics of the LED lamp heat sink for automobile by forced convection for LED heat generation control. In order to analyze the cooling characteristics of the heat sink, the temperature distribution results were investigated through the experiment and computational analysis under the increase of the air flow velocity, and the convective heat transfer coefficient was obtained. Also, convective heat transfer coefficient was calculated by the theoretical formula under the same condition and compared with experimental and computational results. From the result of this study, as the air flow velocity around the heat sink fins increased, the convective heat transfer coefficient significantly increased, confirming the improvement in the cooling effect.

• 한국안전학회지
• /
• 제19권4호
• /
• pp.141-149
• /
• 2004

가솔린 엔진을 장착한 자동차는 고전압발생장치인 점화코일을 이용하여 고전압을 발생 연소실 내의 혼합기를 점화 및 연소시킴으로써 동력을 얻고 엔진을 구동하게 된다. 점화코일은 1차측 낮은 전압을 스위칭 작용으로 2차측 높은 전압을 발생시키고, 이를 전극으로 보내는데, 점화코일에 작은 결함이 발생하게 되면 제 성능을 발휘하지 못한다. 본 연구에서는 현재 사용하고 있는 에폭시 성형 점화코일과 절연재료인 에폭시수지를 시료로 선택하여 시료에 전압이 인가될 때 발생하는 부분방전 특성을 측정하여 전압변화에 따른 위상각, 방전전하량 및 발생빈도 수 등의 분포를 연구하고 검토한 결과를 실제 자동차점화장치에 접목시켜 점화코일의 성능향상과 전기장치의 신뢰성 확보에 기여하고자 한다.

• 산경연구논집
• /
• 제9권3호
• /
• pp.57-68
• /
• 2018

Purpose - The purpose of this study is to classify that the quality factors for comparing the Visegrard Group with the Nordic Council have historical similarities against Germany and the Soviet Union. However, this is because in the integrated European market, the competitiveness possessed by the two groups of countries is invested in the priority order to grow. Research design, data, and methodology - The study was conducted on the research design, and the reason for trying to compare the competence of the automobile industry in the assessment of industrial capability is that the Visegrard Group focuses on automotive production and the Nordic Association focuses on the commercialization of the automobile(market). In this study, searching and quantifying indirect evidence was made through standards are more complementary in Europe since each country acts like the role of the European automotive industry for example, which is different from the realistic evaluation criteria, are more important than those of the United States(first in the world) or Germany(first in Europe). Results - The results of this study are as follows: In the global EV market U.S.(export: $ 2.62 billion /share: 36.7%), Germany($ 1.29 billion /18.1%), France($ 390 million /5.4%), United Kingdom($ 380 million /5.4%), and South Korea($ 320 million/ 4.4%). South Korea's share of the EV market is 4.4%, while TSI reaches at +0.9 which measures the comparative advantage of a specific commodity in the world trade market. There is great potential for evaluated as products processing in export competition. But, commercialization, standardization, and overall market expansion did not have a positive impact on global satisfaction. Conclusions - EVs put importance on various utilities. So this suggests that Korea's exports to the EU, including the Visegrard Group, should be more focused on marketability when illuminating with a sharing industrial system under the European Union. It is necessary to specialize in manufacturing and commercialization by country(region) to prepare sharing economy and blockchain in order to create a smart-sharing city linked on artificial intelligence, as the commercialization of electric vehicles, which will have a larger growth rate than that of manufacturing in the fourth revolutionary era.

• 한국산학기술학회논문지
• /
• 제18권2호
• /
• pp.478-483
• /
• 2017

본 논문에서는 소형 전자기기와 같은 발열부 온도 제어를 위해 압전 소자와 열전 소자를 이용하여 국소부 냉각 성능을 실험적으로 조사해 보았다. 실험은 열전 소자를 이용하여 실험 영역내에 냉각부를 형성하고, 압전 소자에 80Hz와 110Hz 의 인가주파수를 각각 적용하여, 압전 소자를 작동시켰을 때와 작동시키지 않았을 때 열전 소자에 의해 형성된 시험부의 냉각 영역에서 온도 분포를 측정하였다. 또한, 냉각 영역의 온도측정 결과를 토대로 압전 소자를 적용하였을 때와 적용하지 않았을 때 냉각 영역의 성능 계수를 계산하고, 가시화 장치를 구성한 후 시험부내에 냉각 영역의 열유동 현상도 확인해 보았다. 실험결과, 온도분포 측정 실험 결과와 성능 계수 계산 결과로 부터 압전 소자를 작동하지 않은 경우보다 압전 소자를 작동한 경우에서 냉각 성능이 개선되는 것을 확인할 수 있었다.. 또한, 가시화 결과를 토대로 열전 소자에 의해 형성된 냉각 영역에 압전 소자를 작동시켰을 경우에 냉각 영역의 국소부에 압전 소자에 의한 상하 진동의 강제 대류 현상이 발생하면서 냉각영역 전체에 고르게 분포하는 유동을 형성하고 냉각 성능이 개선되는 원인을 확인할 수 있었다.

• 동력기계공학회지
• /
• 제22권6호
• /
• pp.67-73
• /
• 2018

Gasoline that meets the quality standards is distributed in Korea. However, consumers who use toluene or solvent mixed with gasoline have appeared due to rising crude oil prices and for the purpose of tax evasion. Gasoline quality standard is enacted by the domestic and international research reference. A wrong fuel can influence automobile performance or environmental issue. Thus, empirical data from this issue is necessary. Therefore, this research observed catalyst influence by gasoline property change and inspect influence of environment. In this study, fuel property evaluation, lean-burn evaluation, and real vehicle exhaust emission test were performed. In the result of fuel property, the fuel "A" was measured to be up to 27% less octane than the normal gasoline and the distillation property was measured 24% higher than normal gasoline. In the test result of single cylinder engine lean-burn test, the fuels "A" and "B" show torque value 20% less than the normal gasoline. As a result of vehicle test using the catalyst, the fuel "A" was increased more than the normal gasoline with 83% THC, 1,806% CO and 128% NOx, and the fuel "B" was increased more than normal gasoline with 1.6% THC, 391% CO and 142% NOx.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1996년도 하계학술대회 논문집 B
• /
• pp.1107-1109
• /
• 1996

In this paper, we discuss the automatic recognition system of vehicle types and licence plate numbers using artificial neural networks, which will be used as vehicle identifier. We confine to expose the vehicle licence number for violating bus lane and stolen cars. Therefore, the vehicle height, width and distribution profile are used as the feature parameters of vehicle type. This system is composed of two parts: one is an image preprocessor of vehicle images and the other one is a pattern classifier by neural networks. The experimental results show that our method has good results for the recognition of vehicle types and numbers.