• Journal of Sensor Science and Technology
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• v.33 no.3
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• pp.179-184
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• 2024

In the car industry, welding is a fundamental linking technique used for joining components, such as steel, molds, and automobile parts. However, accurate inspection is required to test the reliability of the welding components. In this study, we investigate the detection of weld beads using 2D image processing in an automatic recognition system. The sample image is obtained using a 2D vision camera embedded in a lighting system, from where a portion of the bead is successfully extracted after image processing. In this process, the soot removal algorithm plays an important role in accurate weld bead detection, and adopts adaptive local gamma correction and gray color coordinates. Using this automatic recognition system, geometric parameters of the weld bead, such as its length, width, angle, and defect size can also be defined. Finally, on comparing the obtained data with the industrial standards, we can determine whether the weld bead is at an acceptable level or not.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.5
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• pp.538-548
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• 2016

The purpose of this study is to identify the possibility of effective tuning works, understand the characteristics of tuning engine, and analyse the basic data of engine tuning inspection corresponding to the safe operation and environment of a driving gasoline car. The effects of tuning on the characteristics of performance and exhaust emissions under a wide range of engine speeds are experimentally investigated by the actual driving car with a four-cycle, four-cylinder DOHC, turbo-intercooler, water-cooled gasoline engine operating at four types of non-tuning, tuning 1, 2 and 3. The tuning parts in the gasoline engine are the intake manifold, intake pipe and air filter. In the experiment, the output, torque and air-fuel ratio of the five-speed automatic transmission vehicles were measured at the chassis dynamometer(Dynojet 224xLC) with one person on board. The exhaust emissions of $NO_X$, THC, CO, $O_2$ and $CO_2$, and excess air ratio(${\lambda}$) at the other chassis dynamometer(DASAN-MD-ASM-97-KR-HD) were also measured by the idle/constant-speed mode(ASM2525 mode) test method. It is found that the actual air-fuel ratios of non-tuning and tuning engines were shown to be lower than the stoichiometric air-fuel ratio with increasing engine speed, and the actual air-fuel ratio of non-tuning engine was slightly higher than those of tuning engines when the engine speed is more than 4000 rpm. The output was significantly increased by the tuning whereby the maximum output of tuning engine was more increased to approximately 117.64% than that of non-tuning engine. In addition, CO, THC and $NO_X$ emissions of non-tuning and tuning engines measured by the constant-speed test mode were all satisfied with the inspection standards. CO emission was increased, while THC and $NO_X$ emissions were reduced by tuning.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.4
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• pp.396-410
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• 2012

The purpose of this study is to quantify the contribution of high emitting vehicles to mobile emission inventories. Analyzed emission data include $NO_x$, HC, and CO results, which were measured through the vehicle Inspection and Maintenance (I/M) program in Seoul metropolitan area. The high emitting vehicles were identified as the top 5% worst polluting cars of the fleet. We estimated that 5% of the gasoline passenger car fleet, which is high emitters, generated 25.5% of $NO_x$, 34.5% of HC, and 66.1% of CO emissions of total inventories for gasoline passenger car fleet in year 2010. In the study, we identified that the older vehicles (older than ten years) and high mileage vehicles (more than 120,000 km driven) comprised high emitter fleet with 70.9% and 71.2%, respectively. The emission contribution of high emitters became larger in younger fleet than in the older fleet. This is due to the reduced emission rates in newly manufactured vehicles, which were developed under the more stringent emission regulation limits. This analysis implies that high emitters could be responsible for an even larger fraction of total vehicular emissions as more advanced technology vehicles are being incorporated into the current vehicle fleet. The findings suggested that the high emitting vehicles should be primarily considered for in-use vehicle emission management program, such as I/M, accelerated vehicle retirement, or catalytic converter replacement, in order to enhance the effectiveness of selected program.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1656-1664
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• 2007

This paper introduces a study of improvement for a defect diagnosis of the UM71C track circuit using on HSL. The track circuit on HSL has long operation section. Therefore, when the worker maintain, many times and efforts are spent. So, periodically, we have operated a inspection car. However, we don't know exactly the state changed of the inspection data when track circuit has defect. Actually, We fixed a sample area within operation section on HSL and performed the simulations for short circuit current that is reflected characteristic impedance and propagation factor. We compared the measuring data with the result of the simulation. Using verified simulation program, we estimated inspection data as the malfunction number and the change of capacity of compensation capacitor. These study need to secure of the safety as the train operation. Also, It needs to make a criteria of analysis for the maintenance through comparison simulation data and inspection data.

• Journal of Distribution Science
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• v.7 no.3
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• pp.49-69
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• 2009

With the proliferation of electronic commerce, online transactions have become a norm. Its enormous potential, however, can be truly realized if consumers feel comfortable facing invisible sellers over the Internet, a virtual business channel. Trust has been identified as a key component in many e-Commerce studies. The purpose of this study is to find out which factors play a major role in building buyer trust and how the build-up trust affects buyer's purchase intention in online used car transactions. Based on the information asymmetry, TAM (Technology Acceptance Model), and the trust theory, our research model includes factors such as a buyer's propensity-to-trust, institutional characteristics (inspection and warranty policy), word-of-mouth referral, perceived size, and perceived benefits as independent variables. The model also includes trust as a mediate variable, purchase intention as a dependent variable, and perceived quality risk as a moderate variable. The research model is tested by analyzing 448 sample data gathered from used car websites. The result shows that the trust has significant effects on the online purchase intention, and institutional characteristics have been identified as one of the most significant factors for trust building in used car websites. For those who perceive quality risk high, actual purchasing behavior occurs only when they have trust on the used car websites, indicating that trust plays a vital role as a mediate variable. This study suggests that buyer trust on the used car websites is important to increase buyer's online purchase behavior.

• Journal of Industrial Technology
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• v.24 no.A
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• pp.37-46
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• 2004

A performance analysis for newly being considered electric rail car office has been made in this study. The major purpose is to examine a proposed design in terms of its capacity and the proposed number of travels (82-84) per day. For this study we first examined the overall system configuration with detailed operational processes of cleaning and inspection. We then developed a simulation model using ARENA and designed input data from 12 selected factors and their interaction effects. A simulation run for each treatment combination of $L_{16}(2^{15})$ orthogonal array was run and 20 batch means were obtained. Through careful analyses of the results obtained, we drew a diversity of suggestions including the best factor level combination. Our confirmation experiments at the optimal level combination further validate the possibility of 82 runs and the consistency in the results.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.4
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• pp.455-462
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• 2015

A feature line is a visually noticeable creased line on outer automotive panels. Feature lines play an important role in creating a good impression of a car. Even though the manufacturing quality of feature lines is important, it is difficult to achieve the designed shape owing to the springback of sheet metal. The current study presents five methods of making samples that will be used in a visual experiment to discover a quality control quantitative manufacturing allowance for feature lines. Measurement and inspection methods for the samples are also presented. The results show that plunge machining is the most accurate way to make the desired shape, and that wrapping the machined surface with sheet film is an appropriate way to emulate the roughness and visual texture of the painted outer panels of a car.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.1
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• pp.29-35
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• 2020

Car inspection systems are regularly carried out by the state to ensure the safety and emission status of cars, thereby improving the safety and quality of life by reducing fine dust and greenhouse gases that are the main culprits of vehicle defects and air pollution. These automobile inspections are largely divided into either regular or comprehensive inspections. This study analyzed the smoke measuring probes used in the lug - down 3 mode. In the previously issued paper "Improvement of Soot Probe Efficiency for Automotive Emission Measurement," an improved smoke measurement probe(B) improved on the problems that arise from the current smoke measurement probe (A). In this study, a technique that can improve the probe's inhalation efficiency over the improved (B) probes was applied to probes (C). Probe (C) involves a structure designed close to the center of the circumference of the exhaust pipe, and the suction efficiency was improved by adding a variable center unit.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.4
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• pp.87-96
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• 1996

The proportional pressure control valve(PCV) is an essential component in the open loop controlled rear wheel steering gear of the four wheel steering(4WS) system on the passenger car. The valve should have versatile functions and higher performance. But, it is hard to find the proportional pressure control valve suitable for the 4WS system. In this paper, the determination of the valve parameters was studied by the stability discrimination and the characteristic analysis for the purpose of the development of a new PCV for the 4WS. The mathematical model of the valve was derived from the valve-cylinder system and the programme for numerical computation was developed. The transfer function of the system was obtained from the mathematical model. The characteristics of the valve were inspected through the experiment and compared to those obtained by numerical method. And then the stability discrimination of the system was done by root locus and the analysis of characteristics was done by the developed programme. From the experiment and the analysis of characteristics was done by the developed programme. From the experiment and the inspection, the appropriation of mathematical model and the usefulness of the programme were confirmed. And the parameters which might affect the performance of the valve can be determined by considering the stability discrimination, the characteristics analysis and required functions.

• Journal of ILASS-Korea
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• v.23 no.3
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• pp.128-135
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• 2018

In this study, the following conclusions could be obtained from the analysis of emissions contribution rates and features for contaminated emissions by 13,456 gasoline vehicles passed in the vehicle load test (ASM-idle) under the inspection year 2013 to 2017. It was confirmed that the contamination of the CO, HC, NOx by the displacement is reduced on over 3L engine. As a result of comparing the exhaust gas in the low speed idle mode and the AS2525 mode, the exhaust gas in the low speed idle mode was measured high. It is estimated that if ISG function is applied, emissions from idle condition will be reduced. NOx emissions were reduced when the engine power was above 200HP. It has been confirmed that the amount of exhaust emissions are significantly reduced for vehicles manufactured after 2004. As a result of analyzing the exhaust gas according to the season, it is judged that there is a correlation between HC and NOx according to the ambient temperature. The concentration of exhaust emission in vehicles with high accumulated distance increases, which is considered to be the result of aging of the vehicle.