• Proceedings of the KSR Conference
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• 2000.05a
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• pp.202-209
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• 2000

This paper introduces the main function and protection method of IGBT gate driver that designed by KOROS. Recently, the applications of insulated gate bipolar transistors(IGBTs) have expanded widely, particularly in the area of railway converters. This driver is suitable for railway traction applications, so they are designed for circumstance of railway vehicle such as vibration. The input control power for this driver is supplied from battery charger of railway. it is no necessary an isolated power supply board or auxiliary power supply, with substantial savings in cost and space in railway applications. This gate driver can be used wide range of input voltage. So, performance of the driver has no relation with the battery voltage(70V∼110V). The protection methods of IGBT gate driver have many kind of ways, but this gate driver it designed to apply to converter for railway system, so this gate driver includes protection for arm short current and low control power voltage, etc. And the process of protection method and protection reference value are optimized by means of sufficient test with our own facilities.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.7
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• pp.474-480
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• 2003

We designed and tested a new scan driver output stage. Compared to conventional CMOS structured scan driver IC′s, the new NMOSFET-only scan driver circuit can reduce the chip area and therefore, the chip cost considerably. We confirmed the circuit operation with open drain power NMOSFET IC′s by driving 2"PDP test panel. We defined critical device parameters and their optimization methods lot the best circuit performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.3
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• pp.1722-1741
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• 2017

Intrusion detection techniques based on virtual machine introspection (VMI) provide high temper-resistance in comparison with traditional in-host anti-virus tools. However, the presence of semantic gap also leads to the performance and compatibility problems. In order to map raw bits of hardware to meaningful information of virtual machine, detailed knowledge of different guest OS is required. In this work, we present VDSM, a lightweight and general approach based on driver separation mechanism: divide semantic view reconstruction into online driver of view generation and offline driver of semantics extraction. We have developed a prototype of VDSM and used it to do intrusion detection on 13 operation systems. The evaluation results show VDSM is effective and practical with a small performance overhead.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.508-510
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• 2005

In this paper, we have studied for the current control method with high accuracy for the high power LED driver that is necessary to the lighting system using LEDs. The control performance of LED driver can be improved with the adjustment of current control boundary by introducing D/A converters for setting high-offset and low-offset. And microprocessor (ATmega128) and D/A converter with 8 bits resolution are used in the proposed driver so that LED's illumination can be remotely controlled by serial communication on the spot or by key input. In the results of performance tests, we confirmed that the proposed control method is superior to the conventional control method using op-amps.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.172-178
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• 2007

The purpose of Railroad Vehicles License Management in accordance with the Railroad Safety Law is to improve the quality of railroad safety. And the train simulators come into use for training of train operation and testing to issue Railroad Vehicles License. So, It is very important that the simulators for the Railroad Vehicles License Test require to work correctly, to measure driver's operation quality in numerical system and to ensure the justice of license test. In fact, nobody can guarantee that the simulators are feasible performance to use in license test. The simulator for train driver license test can be used effectively for studying of needed performance and quality to test new driver's skill. This study hopefully provides the base for improving the quality of the simulator for train driver's license test and contributes furthermore to improve the simulator development technology and railroad safety.

• Journal of Biomedical Engineering Research
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• v.18 no.3
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• pp.315-323
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• 1997

Driving is a complex vigilance task that includes improper lookout, excessive speed and inattention. The primary objective of this research is to detect driver drowsiness so that the driver can be alerted to an impending traffic accident in performance. We developed the automatic detection and warning system during drowsy driving. A drowsiness detection system must be able to monitor driver status and detect the detrimental changes of a driver performance. Eyeblink has been found to be a reliable factor of drowsiness detection in earlier studies. As an additional parameter, we also considered the yawning which often occurs in a low vigilance state and predicts the drowsy state. We used a computer vision method to extract the eyeblink and yawning in the face image sequences. When the drowsy state was detected, the driver was refreshed by alarming device and menthol scent generator after deciding the warning level by fuzzy logic. For the evaluation of our system, we measured the physiological parameters such as EOG and EEG. The results indicated that it is possible to detect and alert the driver drowsiness temporarily or continuously by using our system.

• Journal of Power Electronics
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• v.10 no.4
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• pp.351-356
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• 2010

A new current-balancing multi-channel LED driver is proposed in this paper. The conventional LED driver system consists of three cascaded power conversion stages and its driver stage has the same number of expensive boost converters as those of the LED channels. On the other hand, the proposed LED driver system consists of two cascaded power stages and its driver stage requires only passive devices instead of expensive boost converters. Nevertheless, all of the currents through multi-channel LEDs can be well balanced. Therefore, it features a smaller system size, improved efficiency, and lower cost. To confirm the validity of the proposed driver, its operation and performance are verified on a prototype for a 46" LCD TV.

• International Journal of Automotive Technology
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• v.8 no.3
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• pp.375-382
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• 2007

The multi-driver off-road vehicle drive-line consists of many components, with close connections among them. In order to design and analyze the drive-line efficiently, a modular methodology should be taken. The aim of a modular approach to the modeling of complex systems is to support behavior analysis and simulation in an iterative and thus complex engineering process, by using encapsulated submodels of components and of their interfaces. Multi-driver off-road vehicles are comparatively complicated. The driving-line is an important core part to the vehicle, it has a significant contribution to the performance. Multi-driver off-road vehicles have complex driving-lines, so performance is heavily dependent on the driving-line. A typical off-road vehicle's driving-line system consists of a torque converter, transmission, transfer case and driving-axles, which transfers the power generated by the engine and distributes it effectively to the driving wheels according to the road condition. According to its main function, this paper proposes a modularized approach for design and evaluation of the vehicle's driving-line. It can be used to effectively estimate the performance of the driving-line during the concept design stage. Through an appropriate analysis and assessment method, an optimal design can be reached. This method has been applied to practical vehicle design, it can improve the design efficiency and is convenient to assess and validate the performance of a vehicle, especially of multi-driver off-road vehicles.

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.6
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• pp.564-571
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• 2014

A single-stage current-balancing multi-channel light-emitting diode (LED) driver is proposed in this study. The conventional LED driver system consists of two cascaded power conversion stages, i.e., an isolation DC/DC converter and LED driver. LED driver is usually implemented with the same number of expensive boost converters as those of LED channels to tightly control the current through each LED channel. Therefore, its overall system size is not only bulky, but the cost is rather high. By contrast, the proposed LED driver system is composed of a single power stage with the DC/DC converter and LED driver merged. Although the current balancing circuit of the proposed LED driver requires only passive devices instead of expensive boost converters, all currents through multi-channel LEDs can be well balanced. Therefore, the proposed LED driver features a small system size, improved efficiency, and low cost. To confirm the validity of the proposed driver, its operation and performance are verified on a prototype for a 46" LED TV.

• Electronics and Telecommunications Trends
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• v.38 no.6
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• pp.31-40
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• 2023

Given recent accidents involving autonomous vehicles, driver monitoring technology related to the transition of control in autonomous vehicles is gaining prominence. Driver status monitoring systems recognize the driver's level of alertness and identify possible impairments in the driving ability owing to conditions including drowsiness and distraction. In autonomous vehicles, predictive factors for the transition to manual driving should also be included. During traditional human driving, monitoring the driver's status is relatively straightforward owing to the consistency of crucial cues, such as the driver's location, head orientation, gaze direction, and hand placement. However, monitoring becomes more challenging during autonomous driving because of the absence of direct manual control and the driver's engagement in other activities, which may obscure the accurate assessment of the driver's readiness to intervene. Hence, safety-ensuring technology must be balanced with user experience in autonomous driving. We explore relevant global and domestic regulations, the new car assessment program, and related standards to extract requirements for driver status monitoring. This kind of monitoring can both enhance the autonomous driving performance and contribute to the overall safety of autonomous vehicles on the road.