• 한국자동차공학회논문집
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• 제15권6호
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• pp.102-107
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• 2007

A fast response $CO_2$ ($fCO_2$) analyzer for real-time measurement of carbon dioxide concentration during transient states of internal combustion engines has been developed. This analyzer uses non-dispersive infrared absorption (NDIR) technique for measuring $CO_2$ concentration and Kalman filter for removing noise components from output signals. The analyzer has good linearity, repeatability and drift with a response time of 11 ms; it is sufficiently fast to detect $CO_2$ concentration during transient states of internal combustion engines. The $fCO_2$ analyzer was used to measure transient $CO_2$ concentration of exhaust gas of the SI engine with a standard gas analyzer, and the signal of the $fCO_2$ analyzer was compared to that of the standard gas analyzer. The two concentrations were well matched during the steady state, and the $fCO_2$ analyzer could measure the variations of $CO_2$ concentration during the transient state.

• 한국게임학회 논문지
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• 제10권5호
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• pp.103-113
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• 2010

본 논문은 얼굴의 표정과 몸 동작을 광학식 동작 포착장비를 활용하여 동시에 포착하는 경우에 있어 얼굴 부위 마커들에 대한 노이즈에 강건한 데이터 처리 방법에 대해 다룬다. 일반적인 얼굴 표정만 포착하는 경우와 달리, 몸의 움직임과 동시에 포착할 경우 포착용 카메라가 멀리 있어 얼굴에 붙인 마커들의 궤적 데이터는 특별한 처리를 요한다. 특히 궤적의 표식화, 빈 곳 메우기, 노이즈 제거의 과정이 필수적이며, 이러한 과정을 위해 본 논문에서는 지역좌표에 기반을 둔 궤적 데이터 처리 방법을 제안한다. 지역 좌표는 강체변형에 불변한 특징이 있으며, 얼굴모양의 국지적인 변화를 의미하여, 궤적 데이터처리에 효과적으로 활용 될 수 있음을 보였다. 또한 제안한 방법을 활용하여 애니메이션을 제작해 실제 제작 환경에 적용 가능함을 보였다.

• 한국정보통신학회논문지
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• 제15권9호
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• pp.1865-1870
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• 2011

본 논문에서는 비파괴 검사를 통하여 얻어진 항공 갑판 영상에서, 조직의 결함의 정도를 자동으로 검출하는 방법을 제안한다. 먼저 비파괴 검사를 통하여 얻어진 항공 갑판 영상에서 감마상관 변환과 7${\times}$7 소벨 마스크와 13${\times}$13 소벨 마스크를 각각 적용하여 윤곽선을 추출하고 추출된 윤곽선 영역을 평활화와 평균 이진화 기법을 적용하여 영상을 보정한다. 마지막으로 보정된 영상에서 침식 연산과 팽창 연산을 이용하여 잡음을 제거한 후, 라벨링 기법을 적용하여 항공 갑판의 결함 영역을 추출한다. 실험 결과에서, 항공 갑판에서 결함을 추출하는데 기존의 방법보다 효과적인 것을 확인하였다.

• 비파괴검사학회지
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• 제37권2호
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• pp.106-114
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• 2017

This paper presents an automated subsurface micro void detection technique based on pulsed infrared thermography for inspecting epoxy molding compounds (EMC) used in electronic device packaging. Subsurface micro voids are first detected and visualized by extracting a lock-in amplitude image from raw thermal images. Binary imaging follows to achieve better visualization of subsurface micro voids. A median filter is then applied for removing sparse noise components. The performance of the proposed technique is tested using 36 EMC samples, which have subsurface (below $150{\mu}m{\sim}300{\mu}m$ from the inspection surface) micro voids ($150{\mu}m{\sim}300{\mu}m$ in diameter). The experimental results show that the subsurface micro voids can be successfully detected without causing any damage to the EMC samples, making it suitable for automated online inspection.

• 조명전기설비학회논문지
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• 제20권9호
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• pp.103-109
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• 2006

This research is contents about output characteristic of optic current sensor that use faraday effect. optic current sensor used in an experiment is consisted of three parts.(1) Source of light used laser diode of 1310[nm].(2) Sensor section manufactured circularly according to gas insulated switchgear. And $9/125[{\mu}m]$ standard single mode optical fiber for communication was installed winding 20 [turn] on sensor section core surroundings of diameter 31 [cm].(3) Electrical signal of PD(Photo detector) is collected using NI company's 16bit DAQ board via terminal block. Collected data analyzed by different three signal processing methods. NI company's $Labview^{TM}$ was used to signal processing software. As a result, In signal processing of optic current sensor, we could know that noise greatly more influences the error generation than fluctuation of light intensity. also, 1 class CT(current transformer) manufacture that have error rate less than 1[%] was available by removing these

• 로봇학회논문지
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• 제10권1호
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• pp.1-8
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• 2015

This paper proposes a study for accurate surface localization system using DWT(Discrete Wavelet Transform) and GPS/INS fusion algorithm. Because the propagation in the underwater is not passed by characteristics of the medium unlike the ground, the sonar system like DVL is used instead of GPS. But since these systems are installed on the seafloor and operated, a long time is required for installation and navigation systems are limited outside of the range area. And it is difficult to estimate position in a three-dimensional considering the depth in actual marine environment. In this paper, before the development of underwater localization system, precisely estimated position system is proposed in a two-dimensional by developing surface localization system using removing noise and disturbance with DWT and relatively inexpensive GPS and INS sensor.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.227-229
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• 1997

A new phased-array quadrature RF coil for one or two RF acquisition channels is developed for spine MR imaging. Quadrature RF coils for MRI have been useful to improve the signal-to-noise ratio (SNR) by $"\sqrt{2}"$ using two orthogonal RF coils in combination [1]. More recently, the phased-array RF coil has been proposed for more improvement of SNR by using an array of RF coil elements with a reduced size and coverage for each element. Two new schemes are proposed for the new phased-array quadrature RF coil as follows : (1) Proper overlapping of two quadrature RF coils thus removing the mutual inductance and (2) Attaching preamplifiers right after the coil section and combining the signal with proper phase delays. The coil has been implemented for receive- only mode. It has been tested through phantom and volunteer imaging. The experimental results show the utility of the proposed RF coil.

• 제어로봇시스템학회논문지
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• 제17권2호
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• pp.157-163
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• 2011

This paper proposes a hybrid image stabilizing system which uses both optical image stabilizing system based on EKF (Extended Kalman Filter) and digital image stabilization based on SURF (Speeded Up Robust Feature). Though image information is one of the most efficient data for object recognition, it is susceptible to noise which results from internal vibration as well as external factors. The blurred image obtained by the camera mounted on a robot makes it difficult for the robot to recognize its environment. The proposed system estimates shaking angle through EKF based on the information from inclinometer and gyro sensor to stabilize the image. In addition, extracting the feature points around rotation axis using SURF which is robust to change in scale or rotation enhances processing speed by removing unnecessary operations using Hessian matrix. The experimental results using the proposed hybrid system shows its effectiveness in extended frequency range.

• Asian Pacific Journal of Cancer Prevention
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• 제16권18호
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• pp.8351-8358
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• 2016

Electronic cleansing is an image post processing technique in which the tagged colonic content is subtracted from colon using CTC images. There are post processing artefacts, like: 1) soft tissue degradation; 2) incomplete cleansing; 3) misclassification of polyp due to pseudo enhanced voxels; and 4) pseudo soft tissue structures. The objective of the study was to subtract the tagged colonic content without losing the soft tissue structures. This paper proposes a novel adaptive method to solve the first three problems using a multi-step algorithm. It uses a new edge model-based method which involves colon segmentation, priori information of Hounsfield units (HU) of different colonic contents at specific tube voltages, subtracting the tagging materials, restoring the soft tissue structures based on selective HU, removing boundary between air-contrast, and applying a filter to clean minute particles due to improperly tagged endoluminal fluids which appear as noise. The main finding of the study was submerged soft tissue structures were absolutely preserved and the pseudo enhanced intensities were corrected without any artifact. The method was implemented with multithreading for parallel processing in a high performance computer. The technique was applied on a fecal tagged dataset (30 patients) where the tagging agent was not completely removed from colon. The results were then qualitatively validated by radiologists for any image processing artifacts.

• 한국정보통신학회논문지
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• 제7권6호
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• pp.1297-1303
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• 2003

반도체 방식의 capacitive type 지문인식센서의 신호처리를 위한 개선된 회로를 설계하였다. 최 상위 sensor plate가 지문의 굴곡을 감지한 capacitance의 변화를 전압의 신호로 전환하기위해서 charge-sharing 방식의 회로를 적용하였다. 지문센서 감도저하의 가장 큰 원인인 sensor plate에 존재하는 parasitic capacitance를 최소화하고 ridge와 valley 사이의 전압차를 향상시키기 위하여 기존과는 다른 아날로그버퍼회로를 설계하였다. 센서전압과 기준전압 신호를 비교하기 위해서 비교기를 설계하였으며, 센서어레이의 수직, 수평간 isolation 대책을 통하여 ESD 및 노이즈방지를 위한 설계를 제안하였다. 제안된 신호처리회로는 128${\times}$l44 pixel 규모의 회로로 구현되었다. 본 설계회로는 향후 생체인식을 이용한 정보보호용 지문인식 시스템에 응용될 수 있으리라본다.