• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.317.1-317
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• 2002

In this paper, static analysis of eddy current brake′s frame, which is one of key structural components of brake system for high speed train, was performed in order to evaluate the design by computer simulation. Calculation was carried out in general for the driving modes "braking" and "frame in upper position(brakes inactive)". Several yield stress load cases and fatigue load cases were analysed fur each of the driving modes. (omitted)

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.3
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• pp.106-116
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• 1997

In this paper, using MATLAB SIMULINK, a generalized design methodology was suggested for multi pass transmission(MPT) by classifying the vehicle power train as prime mover, MPT and vehicle dynamics. This approach enables a designer to investigate the influence of each transmission component by simple combination of system components without changes of overall program. Using the design methodology, a MPT consisting of CVT, 2, clutches and reduction gears was designed for a braking energy regenerative flywheel hybrid vehicle. The CVT is essential in order to connect the engine and flywheel speed with the vehicle speed. For the purpose of smooth clutch operation, control algorithm was suggested by introducing dead zone for the clutch engagement. Using the SIMULINK model, performance of the flywheel hybrid vehicle with MPT was investigated. It was observed from the simulation results that the MPT vehicle showed better fuel economy, 47% than that of AT vehicle, 27% than that of CVT vehicle for ECE-15 driving cycle. Especially destinct fuel efficiency improvement was obtained for city driving cycle requiring more frequent stop and start.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.5
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• pp.355-364
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• 2009

Electro-Luminescence (EL) sheets have been widely used in lighting displays, mainly used as advertisement panels. To drive the ELs in optimal conditions, it is required to understand the load profile of the EL. Hence, in this paper, a modeling for an EL sheet was performed to analyze the load characteristics of the EL. Based on the extracted model of the EL, a topology for inverter system was chosen and the optimal design parameters were obtained. The validity of the designed EL driver system was verified through computer simulations and experiments.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.2
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• pp.195-211
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• 2023

For the commercialization For the commercialization of autonomous vehicles (AV), the operational design domain (ODD) of automated driving systems (ADS) is to be clearly defined. A common language and consistent format must be prepared so that AV-related stakeholders can understand ODD at the same level. Therefore, overseas countries are presenting a standardized ODD framework and developing scenarios that can evaluate ADS-specific functions based on ODD. However, ODD includes conditions reflecting the characteristics of each country, such as road environment, weather environment, and traffic environment. Thus, it is necessary to clearly understand the meaning of the items defined overseas and to harmonize them to reflect the specific domestic conditions. Therefore, in this study, domestic optimization of the ODD classification system was performed by analyzing the domestic driving environment based on international standards. The driving environment of currently operating self-driving car test districts (Sangam, Seoul, and Gwangju) was investigated using the developed domestic ODD items. Then, based on the results obtained, the ranges of the ODDs in each test district were determined and compared.

• Proceedings of the KIEE Conference
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• 2008.04c
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• pp.29-31
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• 2008

Recent years have witnessed that the Korean government prompts the 'Power IT' enterprise to combine electric Power industry with information technology (IT). Especially, in a move to shore up the distribution automation system, the necessity for remote control of molded case circuit breaker (MCCB) is getting more and more important. In this paper, we aimed to propose a remote-controlled MCCB of which the driving device is substituted to electrical equipment for mechanical parts. Driving device of MCCB was designed with the Electromagnetic Force driving Actuator (EMFA). Electromagnetic force and dynamic characteristics of the designed EMFA are analyzed using 2-D finite element method (FEM).

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.6
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• pp.76-84
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• 2001

Generally fuel injection system using solenoid have some problems between control signal and mechanical movement like as time lag. Main purpose of the present study is to help the design optimization of GDSI for real engine application. We have adopted two different solenoid driving circuit, namely saturation and pick-hold type and have investigated experimentally the current, needle force, needle opening duration and injection quantity. The pick-hold type driving circuit surpassed a saturation type in the response time and pression control of injection quantity. Accordingly, Using characterization data of operating factors such as time constant, driving force and so on, can be evaluated and adjusted to obtain an optimum injector performance.

• Journal of the Korea Institute of Military Science and Technology
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• v.5 no.1
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• pp.45-58
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• 2002

In this paper, we designed the circuit of drive control for towing winch. It is composed of reference voltage circuit for driving voltage reference, low pass filter circuit for noise reduction, dead zone circuit for initial transient input, and driving circuit for drum direction/velocity control. Also it is realized a drive control circuit for towing winch drum in accordance with PWM(pulse width modulation) method to suit it's purpose of a large capacity driving system. The performance of the designed circuit is analyzed by experiments and the appliablity for driving the towing winch drum satisfactorily is evaluated through a various testing.

• The Journal of Korea Robotics Society
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• v.18 no.3
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• pp.271-280
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• 2023

FMCW (Frequency Modulated Continuous Wave) radar system is widely used in autonomous driving and navigation applications due to its high detection capabilities independent of weather conditions and environments. However, radar signals can be easily contaminated by various noises such as speckle noise, receiver saturation, and multipath reflection, which can worsen sensing performance. To handle this problem, we propose a learning-free noise removal technique for radar to enhance detection performance. The proposed method leverages adaptive thresholding to remove speckle noise and receiver saturation, and wavelet transform to detect multipath reflection. After noise removal, the radar image is reconstructed with the geometric structure of the surrounding environments. We verify that our method effectively eliminated noise and can be applied to autonomous driving by improving the accuracy of odometry and place recognition.

• 한국가스학회:학술대회논문집
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• 2005.10a
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• pp.117-122
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• 2005

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.1
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• pp.92-98
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• 2013

There are lots of studies about hybrid electric vehicles (HEVs) because of the global warming and energy problems. Series and parallel HEVs are the common types of many developing hybrid vehicle types. Series HEV uses engine only as the generator for the battery but parallel HEV utilizes engine for driving and generating of the vehicle. In this paper, backward simulations based on dynamic programming were conducted for the fuel economy analysis of two different types of hybrid transit buses depending on driving cycles. It is shown that there is a relation between the type of HEV and the characteristics of driving cycles. Regarding the aggressiveness, the series hybrid bus is more efficient than the parallel system on highly aggressive driving cycle. On the other hand, the parallel hybrid bus is more efficient than the series system on low aggressive driving cycle. Based on this results of the paper, it is expected to choose more efficient type of the hybrid buses according to the driving cycle.