• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.1
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• pp.107-112
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• 2010

In this paper, we design and implement the contents transferring the location information between a customer and a proxy driver by utilizing 'WIPI.' Customers are able to request a call-service through a client in order to call a proxy driver. And, once a proxy driver who is most adjacent to the customer accepts the order of a call-service from him or her through a location-management server using the concepts of LBS and GPS, 'WIPI' sends the information about the location of the customer to the driver, and also sends information to the custome by calculating the distance from the driver to the customer. This content was modeled based on how information is transferred between a customer and a proxy driver under the mobile circumstance, and also a server and a client, made up from JAVA, were modeled by using SKT emulator.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.6 s.360
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• pp.69-76
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• 2007

A new circuit design for Bus-Invert Coding is presented in this paper. The new scheme sends the coding information through the bus-lines instead of the invert-line which has been used conventionally for many types of Bus-Invert algorithms. By employing a newly developed bus-driver called Flip-Driver and a selection circuit, it not only removes the invert-line but suppresses the additional bus-transitions in sending coding information. It is verified by simulations that the efficiency of various Bus-Invert algorithms is increased about 40% to 100% by employing the new design.

• Journal of Korean Society of Transportation
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• v.8 no.2
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• pp.7-25
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• 1990

In road traffic, road circumstances, vehicle, and driver are closely related each other. When road facilities are established in road planning, only road structure has been considered. However, relatively little work has been done regarding the relation between road circumstances and human with respect to a driver. This dissertation focuses on analysis of driver's visual characteristics to improve road circumstances. In this study, driver's visual characteristics are measured with eye-mark recorder and analyzed statistically. This study includes that visual characteristics, visual range, visual time, distribution of fixation duration, and visual moving angle with respect to road circumstances are established qualitatively and quantitatively by driving testing vehicle on streets, roads and high-ways. The main features of this study are : The driver's visual ranges are different over 10% depending on lane in multi-lanes. The visual range on two-lanes is more than twice as big as that on multi-lanes at 85% of whole vision. The right and left visual ranges by as big as that on multi-lanes at 85% of whole vision. The right and left visual ranges by as big as that on multi-lanes at 85% of whole vision. The right and left visual ranges by as big as that on multi-lanes at 85% of whole vision. The right and left visual ranges by speed are $34^{\circ}$ for 30-50km/hr, $28^{\circ}$ for 50-70km/hr, $22^{\circ}$ for 70-90km/hr and 16^{\circ} for over 90km/hr at 95% of visual rate. Accordingly, increasing speed results in narrow visual range.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.13 no.1
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• pp.50-58
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• 2013

Estimating a driver's head pose is an important task in driver-assistance systems because it can provide information about where a driver is looking, thereby giving useful cues about the status of the driver (i.e., paying proper attention, fatigued, etc.). This study proposes a system for estimating the head pose using monocular images, which includes a novel use of backprojection. The system can use a single image to estimate a driver's head pose at a particular time stamp, or an image sequence to support the analysis of a driver's status. Using our proposed system, we compared two previous pose estimation approaches. We introduced an approach for providing ground-truth reference data using a mannequin model. Our experimental results demonstrate that the proposed system provides relatively accurate estimations of the yaw, tilt, and roll angle. The results also show that one of the pose estimation approaches (perspective-n-point, PnP) provided a consistently better estimate compared to the other (pose from orthography and scaling with iterations, POSIT) using our proposed system.

• International Journal of Automotive Technology
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• v.5 no.4
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• pp.277-285
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• 2004

This paper describes an intelligent mirror adjustment system that rotates a pair of side mirrors and the room mirror of a car to the optimal position for a driver by using the location of the driver's pupils. A stereo vision system measures the three-dimensional coordinates of a pair of pupils by analyzing the input images of stereo B/W CCD cameras mounted on the instrument panel. This system determines the position angle of each mirror on the basis of information about the location of the pupils and rotates each mirror to the appropriate position by mirror actuators. The vision system can detect the driver's pupils regardless of whether it is daytime or nighttime by virtue of an infrared light source. Information about the pair of nostrils is used to improve the correctness of pupil detection. This system can adjust side mirrors and the room mirror automatically and rapidly by a simple interface regardless of driver replacement or driver's posture. Experiment has shown this to be a new mirror adjustment system that can make up for the weak points of previous mirror adjustment systems.

• Journal of Power Electronics
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• v.16 no.4
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• pp.1288-1297
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• 2016

This study proposes a single-stage light-emitting diode (LED) tube lamp driver with input-current shaping for T8/T10-type fluorescent lamp replacements. The proposed AC-DC LED driver integrates a dual-boost converter with coupled inductors and a half-bridge series-resonant converter with a bridge rectifier into a single-stage power conversion topology. This paper presents the operational principles and design considerations for one T8-type 18 W-rated LED tube lamp with line input voltages ranging from 100 V rms to 120 V rms. Experimental results for the prototype driver show that the highest power factor (PF = 0.988), lowest input current total harmonic distortion (THD = 7.22%), and highest circuit efficiency (η = 92.42%) are obtained at an input voltage of 120 V. Hence, the proposed driver is feasible for use in energy-efficient indoor lighting applications.

• The Journal of Korean Physical Therapy
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• v.25 no.5
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• pp.352-359
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• 2013

Purpose: For patients with CNS injury who are restricted in the use of public transportation, car driving means more than simple movements and is essential for their independent lives, such as participation in society and returning to jobs. Therefore, in order to enhance the quality of life of disabled persons, their high perception and necessity of driving rehabilitation are required. The purpose of this study is to determine the perception and necessity of driver rehabilitation in patients with CNS injury. Methods: In order to survey the perception of patients with CNS injury and necessity of driving rehabilitation, questionnaires were distributed to patients with CNS injury. Questionnaires were composed of demographic characteristics, disability related characteristics, and driver's license related characteristics. Results: Our results showed that the number of driving participants with a driver's license for the disabled was significantly higher than that for non- driving participants with a previous general driver's license in the perception of driving rehabilitation. Conclusion: We suggest that driving rehabilitation for patients with CNS injury should be supported in terms of evaluation and treatment.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.1
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• pp.71-77
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• 2008

This paper proposes an Electronic Throttle Body (ETB) model considering a non-linearity of DC motor driver which is integrated with a H-bridge and a gate driver. A propagation delay and reverse recovery time of switching components cause non-linear characteristic of DC motor driver. This non-linearity affects not only the amateur voltage of DC motor, but also entire behaviour and parameters of ETB. In order to analyze the behavior of ETB more accurately, this non-linear effect of DC motor driver is modeled. The developed ETB model is validated by use of the step response and ramp response experiments, and it shows relatively accurate results compared with linear DC motor driver model.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.4
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• pp.81-90
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• 2017

This paper presents a smart seat for correction of driver posture while driving. We introduce good postures with seat height, seat angle, head height, back of knees, distances of foot pedals, tilt of seat, etc. There have been some studies on correction of good posture while driving, effects of driving environment on driver's posture, sitting strategies based on seating pressure distribution, estimation of driver's standard postures, and others. However, there are a few studies on guide of good postures while driving for problem of driver's posture using machine leaning. Therefore, we suggest a smart seat for correction of driver's posture based on machine leaning, 1) developed the system to get postures by 10 piezoelectric effect element, 2) collect piezoelectric values from 37 drivers and 28 types of cars, 3) suggest 4 types of good postures while driving, 4) analyze test postures by kNN. As the results, we can guide good postures for bad or problems of postures while driving.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.4
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• pp.612-616
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• 2012

This paper presents an active current regulator for LED driver IC. The proposed driver circuit is consists of DC-DC converter for supplying constant DC voltage to LED, active current regulator for compensating channel-to-channel current error from LED strings and feedback circuit for controlling duty ratio of the converter. The proposed active current regulator senses current of LED channels by equalizing both $V_{DS}$ and $V_{GS}$ at LED current control transistor. Because the proposed circuit directly measures the LED channel current without a sensing resistor and regulates all channel with same regulation loop, the power consumption and the current error are much small compared with previous works. The measured maximum efficiency of overall LED driver IC is approximately 94% and current error of LED channel-to-channel is under ${\pm}1.3%$. The proposed LED driver IC is fabricated Dongbu 0.35um BCD process.