• Proceedings of the PSK Conference
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• 2003.10b
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• pp.67.3-68
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• 2003

The purpose of this study is to improve repeatability of a non-invasive blood glucose measurement. The portable NIR system that was newly integrated by our lab includes a tungsten halogen lamp, a specialized reflectance fiber optic probe and a photo diode array type InGaAs detector, which was developed by a microchip technology based on the lithography. Reflectance NIR spectra of finger tip were recorded by using a fiber optic probe. The probe was fixed in the system and subjects put their finger on the probe head. (omitted)

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.3
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• pp.276-280
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• 2016

This study investigated luring distributions by water layer of common squid which were targeted by angling fishing vessels equipped with LED and metal-halide lamps using a scientific echosounder with a 120 kHz frequency in order to develop energy-effective underwater fish aggregation devices. In the analysis, angles of a transducer were changed from $0^{\circ}$ to $45^{\circ}$ and were rotated every $10^{\circ}$ horizontally. It was shown that common squid were densely distributed from the surface to 40 m and they were also distributed in directions of $10^{\circ}{\sim}+30^{\circ}$, $-30^{\circ}{\sim}-60^{\circ}$, and $-120^{\circ}{\sim}-130^{\circ}$with the head of vessel as the center. Comparative results of angles of transducer on acoustical densities of common squid distributing in 21~40 m water depth showed an average $101.8m^2/nm^2$ in vertical direction of $0^{\circ}$, $12.3m^2/nm^2$ in angle of $30^{\circ}$, and $42.4m^2/nm^2$ in angle of $45^{\circ}$, respectively. It implied that more considerations on acoustic scattering strength by incidence angle direction of the transducer and swimming oriental angle direction of common squid would be required.

• Tribology and Lubricants
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• v.35 no.1
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• pp.59-64
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• 2019

When slipping occurs between two materials, the coefficients of friction must be considered because these values determine the overall efficiency of the machine or slip characteristics. Therefore, it is important to find the coefficient of friction between two materials. This paper focuses on obtaining the coefficient of friction between an aiming bolt and a retainer located in the headlamps of a vehicle. This bolt supports the headlamp, and if the bolt is loosened by external vibration, the angle of the light will change and block the vision of pedestrians or other drivers. In order to study these situations, the coefficient of friction between aiming bolts and retainers needs to be measured. In addition, the coefficient of friction of materials used in the headlamp should be obtained. To determine these two factors, a new device is designed for two cases: surface-surface contact and surface-line contact. To increase reliability of the results, the device is designed using an air-bearing stage which uses compressed air as lubricant to eliminate the friction of the stage itself. Experiments were carried out by applying various vertical forces, and the results show that the coefficient of friction can be measured consistently. The procedure for designing the device and the results are discussed.

• Korean Journal of Ichthyology
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• v.27 no.2
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• pp.153-158
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• 2015

Five specimens of Lethotremus awae (Cyclopteridae) were collected from the northern coastal waters of Jeju Island, Korea, during a survey on larval and juvenile fishes flocking to aquatic lamp in 2004 ~ 2007. They were characterized by having a spherical body with three barbel-like tubes on head and the first dorsal fin overgrown by skin with undiscernible rays as well as VIII-9 dorsal fin rays, 8 ~ 9 anal fin rays and 22 ~ 23 pectoral fin rays. A new Korean name, "Eom-ji-do-chi", was proposed for the species.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.777-783
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• 2001

This paper is mainly concerned with the state of the practical developments of a constants PWM bridge type resonants DC-DC suitable converter for Nd:YAG Laser with a Microprocessor. (PIC16C54 & 8051) The use of IGBT power supply with feedback control of flashLamp currents imparts a advantages to Nd:YAG Laser for materials processing. these include the alility to tailor the pulseshape and modify pulse parameters on a pulse- by pulse basis. And Correct choice of pulseshape can enhance the repeatability of the process. as higher power IGBT became available, act ive pulseforming power supplies will find greater user in deep hole drilling machine By Using certain control tecniques, utililized in designing Pic16c54 from Microchip technology and Intel 8051, also Mornitoring from Microsoft Visual Basic 5, And it allowed us to designed and fabricate ahigh repel it ion rate and high power(HRHP) pulsed Nd:YAG laser system, As a result of that, the current pulsewidth could be contort led 200s to 350s(step 50s) , and the pulse repetition rate could be adjusted 500pps to 1150pps. In addition, in the case of one laser head consisting of a Nd:YAG laser rod and two flashlamps , the maximum laser output of 240w was produced at the condition of 350s and 1150pps, and that of about 480w was generated at the same condition when two laser heads were arranged in cascade.

• Transactions of Materials Processing
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• v.25 no.1
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• pp.29-35
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• 2016

In the current study, finite element analysis was conducted for the press hemming of automotive panels in order to predict various hemming defects such as roll-in and turn down. The analysis used the exact punch movement based on the cam location and considered the sealer between the inner and outer panels with an artificial contact thickness. The analysis results quantify the hemming defects especially at the flange edge in the matching region of the head lamp. A design of experiments along with the parameter study was used to obtain the optimum process parameters for minimizing hemming defects. The optimization process selects the intake angle, bending angle of the hemming punch, and the flange height of the outer panel. The optimum design process determines an appropriate tool angle and flange height to reduce the roll-in and turn-down as compared to the initial design.

• Journal of ILASS-Korea
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• v.14 no.3
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• pp.109-116
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• 2009

The purpose of this study is the experimental and numerical investigation on the DME spray characteristics in the combustion chamber according to the injection timing in a common-rail injection system. The visualization system consisted of the high speed camera with metal halide lamp was used for analyzing the spray characteristics such as spray development processes and the spray tip penetration in the free and in-cylinder spray under various ambient pressure. In order to observe the spray characteristics as a function of injection timing, the piston head shape of re-entrant type was created and the fuel injected into the chamber according to various distance between nozzle tip and piston wall in consideration of injection timing. Also, the spray and evaporation characteristics in the cylinder was calculated by using KlVA-3V code for simulating spray development process and spray tip penetration under real engine conditions. It was revealed that the high ambient pressure of 3 MPa was led to delay the spray development and evaporation of DME spray. In addition, injected sprays after BTDC 20 degrees entered the bowl region and the spray at the BTDC 30 degrees was divided into two regions. In the calculated results, the liquefied spray tip penetration and fuel evaporation were shorter and more increased as the injection timing was retarded, respectively.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04a
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• pp.261-264
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• 2002

자동차 전조등에서 나오는 데이터는 다양한 패턴을 가지는 영상자료와 부분적으로 보이는 문자자료이다. 내용기반 영상검색을 통해 자동차 전조등에서 검사자가 판독하는 텍스트와 부분적인 전조등의 영상정보로 차량의 정보를 추출하기 위한 검색 방법을 국립과학수사연구소의 자료를 기반으로 설계하였으며, 영상검색에 사용된 영상특징값의 구성과 영상 검색방법을 연구하였다. 본 논문에서는 영상데이터의 검색을 위해 효과적인 영상특징이 추출 되도록 향상된 방법론을 제시하였다. 특징함수에 대한 유효성 검증을 위해 샘플 영상에서 각 후보 특징함수들에 대한 결과값들을 비교하였으며, 이를 기반으로 유효한 특징함수를 찾아서 검색에 사용되어지도록 구성하였다. 사용되어진 영상의 특징값은 전조등 영상이 가지는 다수의 텍스쳐함수와 가로, 세로 성분값을 사용하였다. 영상 검색을 위해 추출된 영상 특징값을 데이터베이스화하고 용의차량의 전조등 영상을 질의 영상으로 하여 후보 차량에 대한 정보를 검색하도록 하였다.

• IEMEK Journal of Embedded Systems and Applications
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• v.10 no.5
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• pp.325-333
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• 2015

Vision based night-time vehicle detection has been an emerging research field in various advanced driver assistance systems(ADAS) and automotive vehicle as well as automatic head-lamp control. In this paper, we propose night-time vehicle detection method based on multi-class support vector machine(SVM) that consists of thresholding, labeling, feature extraction, and multi-class SVM. Vehicle light candidate blobs are extracted by local mean based thresholding following by labeling process. Seven geometric and stochastic features are extracted from each candidate through the feature extraction step. Each candidate blob is classified into vehicle light or not by multi-class SVM. Four different multi-class SVM including one-against-all(OAA), one-against-one(OAO), top-down tree structured and bottom-up tree structured SVM classifiers are implemented and evaluated in terms of vehicle detection performances. Through the simulations tested on road video sequences, we prove that top-down tree structured and bottom-up tree structured SVM have relatively better performances than the others.

• IEMEK Journal of Embedded Systems and Applications
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• v.10 no.5
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• pp.297-305
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• 2015

AFLS (Adaptive front lighting System) is being applied to improve safety in driving automotive at night. Safe embedded system for controlling head-lamp has to be tightly designed by considering safety requirement of hardware-dependent software, which is embedded in automotive ECU(Electronic Control Unit) hardware under severe environmental noise. In this paper, we propose an adaptive headlight controller with newly-designed symmetric angle sensor compensator, which is integrated with ECU-based adaptive front light system. The proposed system, on which additional backup hardware and emergency control algorithm are integrated, effectively detects abnormal situation and restore safe status of controlling the light-angle in AFLS operations by comparing result in symmetric angle sensor. The controlled angle value is traced into internal memory in runtime and will be continuously compared with the pre-defined lookup table (LUT) with symmetric angle value, which is used in normal operation. The watch-dog concept, which is based on using angle sensor and control-value tracer, enables quick response to restore safe light-controlling state by performing the backup sequence in emergency situation.