• 한국전기전자재료학회논문지
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• 제20권11호
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• pp.953-958
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• 2007

In this paper, multilayer actuator structured-ultrasonic nozzle and resonant inverter driving circuit were manufactured, respectively. Its electrical properties were investigated. Multilayer actuator structured ultrasonic nozzle was fabricated using PMN-PNN-PZT ceramics showing excellent piezoelectric characteristics. In order to drive ultrasonic nozzle, resonant PWM inverter was used. The purpose of this study is to find the optimal driving condition of ultrasonic nozzle. Accordingly, electrical and temperature characteristic of multilayer ultrasonic driving system were investigated by experiments as a function of the series resonance inductance. The driving current of ultrasonic nozzle showed the maximum current of 27 mA. Also, the surface temperature of ceramic vibrator showed $44^{\circ}C$ at driving time for 20 min. The ultrasonic nozzle was stably operated in the case of driving for more than 20 min.

• International Journal of Computer Science & Network Security
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• 제22권4호
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• pp.237-244
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• 2022

Eco-driving of vehicles today presents an advantage that aims to reduce energy consumption and limit CO2 emissions. The application for this option is possible to older vehicles. In this paper, we propose an efficient implementation for IoT (Internet of Things) system for controlling vehicle components that affect the quality of driving (acceleration, braking, clutch, gear change) via Smartphone using Wi-Fi and BLE as communication protocol. The user can see in real-time data from sensors that control driver action on vehicle driving systems such as acceleration, braking, and vehicle shifting through a web interface. Thanks to this communication, the user can control his driving quality and, hence, eco-driving can be achieved

• 산업공학
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• 제20권3호
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• pp.309-314
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• 2007

By an explosive increase of proxy driving, customers require the quick and correct services of call center. But because most call centers have an unsystematic management system, grievance of customers is continually increasing. To solve these problem, we constructed a call center system of proxy driving that is based on CTI (Computer Telephony Integration) in this paper. The proposed system is constructed using CID (Caller Identify Display) terminal, SMS (Short Message Service) and call center management program etc. Customer service level could be improved through efficient customer management by using the proposed system. Also it could be convenient and easy to implement customer management, order management, staff management, SMS and settlement of accounts.

• 한국자동차공학회논문집
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• 제12권3호
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• pp.37-43
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• 2004

Engine lubrication system is generally affected by vehicle driving conditions; acceleration, braking deceleration, and cornering. The oil supply system such as oil pan, baffle plate, and oil pick-up pipe should be optimized to cope with severe driving conditions. The main purpose of this paper is to understand the effect of the engine tilting angle on the oil supply system using engine tilting test rig. For the purpose, the oil pressure fluctuation and oil aeration in the main gallery are measured at various engine tilting angles. In addition, the oil flow is visualized by using transparent oil pan to investigate the cause of the formation of oil aeration. The test results show there is a strong correlation between the main gallery oil pressure fluctuation and oil aeration. It is also found that the visualization technique is helpful to stabilize the oil supply system at severe driving conditions.

• 한국기계가공학회지
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• 제3권3호
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• pp.71-78
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• 2004

The loader of this study is an agriculture machine for a stock farmer. We has much researched about power train and steering system in order to develop a new stock machine. So, the loader developed in this study has a 4 wheel driving system and a 4-type wheel steering system. Though the technological region is some large and general, these technologies are very important and their technical life may be very long. The power train of the loader is consisted of many units as follows, engine, clutch, transmission, and axles. And, the 4-type wheel steering system is consisted of oil tank, oil pump, steering valve, solenold valve, electronic controller, hydraulic cylinders, and touch sensors. This study shows construction logics of power train and steering system. We could know from many working tests that the developed loader with 4-type steeling system has many advantages when driving in a narrow corral.

• 자동차안전학회지
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• 제7권2호
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• pp.25-31
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• 2015

This paper presents a performance evaluation procedure for advanced emergency braking (AEB) system. To guarantee the performance of AEB system, AEB test scenario should contains various driving conditions which can be occurred in real driving condition. Also, performances of each elements of AEB system, such as sensor, decision, human machine interface (HMI) and control, should be evaluated in various situations. For this, driving conditions, road types, environment, and elements of AEB system were introduced. Test scenario has been designed to represent the real driving condition and to evaluate the safety performance of AEB system in various situations. To confirm that the proposed AEB test scenario is realistic and physically meaningful, vehicle test have been conducted in two cases of proposed AEB test scenario: subject vehicle cut-out scenario and narrow street turn left scenario.

• 한국기계가공학회지
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• 제18권12호
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• pp.111-116
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• 2019

With the recent acceleration of industrial technologies and active research, wearable robot technologies have been applied to various fields. To study the utility of wearable robots, basic research on kinetic mechanisms of the human body, bio-signal analysis, and system control are essential. In this study, we investigated the basic structure of a wearable system and the operating principles of a driving mechanism. The control system and supporting structure, which comprise the driving mechanism, were designed and manufactured. Motion and load analyses were performed simultaneously for the design of the kinematic drive, and the driving mechanism was constructed by analyzing walking motion. The operating conditions of the cylinder were verified by stride via driving experiments. Further, the accuracy and responsiveness of the system were confirmed by comparison with actual motion, and the system safety was validated by applying loads.

• 한국신뢰성학회지:신뢰성응용연구
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• 제17권3호
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• pp.207-212
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• 2017

Purpose: This article provides an efficient cushion molding method for improving reliability of the rotation driving system. Method: Allowable stress level for cushion is calculated by using physical characteristics of the rotation driving system. In addition, various test units are manufactured and used to conduct the rebound resilience, the burst pressure and the alternating load test. Results: Actual allowable stress level and test results of the rebound resilience, the burst pressure and the alternating load test are provided. Conclusion: The cushion manufactured by the compression molding method gives more preferable characteristics for improving the reliability of the rotation driving system.

• ETRI Journal
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• 제41권4호
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• pp.506-514
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• 2019

Currently, studies on autonomous driving are being actively conducted. Vehicle positioning techniques are very important in the autonomous driving area. Currently, the global positioning system (GPS) is the most widely used technology for vehicle positioning. Although technologies such as the inertial navigation system and vision are used in combination with GPS to enhance precision, there is a limitation in measuring the lane and position in shaded areas of GPS, like tunnels. To solve such problems, this paper presents the use of LED lighting for position estimation in GPS shadow areas. This paper presents simulations in the environment of three-lane tunnels with LEDs of different color temperatures, and the results show that position estimation is possible by the analyzing chromaticity of LED lights. To improve the precision of positioning, a fuzzy logic system is added to the location function in the literature [1]. The experimental results showed that the average error was 0.0619 cm, and verify that the performance of developed position estimation system is viable compared with previous works.

• 한국대기환경학회지
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• 제31권6호
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• pp.562-572
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• 2015

$NO_x$ emissions from diesel vehicles have been regarded as a main cause of high $NO_2$ concentration in metropolitan area. Recent studies have shown that the on-road $NO_x$ emissions of diesel vehicles are quite higher than the emission limits specified with the pre-defined test method for emission certification. To reduce air pollutants effectively, the discrepancy of emissions in certification and real-driving conditions should be tackled. In this study, the real-driving emissions have been estimated with portable emission measurement system (PEMS). The results of this study have shown that the on-road $NO_x$ emissions from diesel vehicles have been decreased as the introduction of stricter emission regulation, EURO-6, but additional reduction should be still required and robust technologies should be applied to control $NO_x$ in real-driving conditions. RDE-LDV (Real Driving Emission - Light Duty Vehicles) test method being developed in the European Union can represent excessive on-road $NO_x$ emissions of diesel vehicles as applied emission technologies and can be a solution to remove discrepant $NO_x$ emissions between certification and Korean real-driving conditions. Among the $NO_x$ reduction technologies for EURO-6 diesel vehicles, selective catalytic reduction (SCR) system has shown the better performance than lean $NO_x$ trap (LNT) system to control on-road $NO_x$ emissions. Implementing RDE-LDV will require vehicle manufacturers to adopt the more effective $NO_x$ reduction technology in real driving conditions.