• 한국통신학회논문지
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• 제29권5C호
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• pp.618-626
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• 2004

본 논문에서는 로봇의 endeffector를 인식하기 위하여 모듈라 신경회로망인식 시스템을 제안 및 구현하였다. 본 논문에서 제안한 로봇 endeffector 인식시스템은 영상을 획득하고 획득한 영상에서 전처리를 이용하여 로봇의 enddffector를 검색하기 위한 특징 값들을 구한다. 3차원 공간에서 로봇의 endeffector는 움직임에 따라 다양한 형태로 변화하므로 빠르고 정확하게 endeffector를 인식하기 위하여 위치검출 신경회로망 모듈과 크기 검출 신경회로망 모듈로 이루어진 다중모듈신경회로망(MNN; Modular Neural Network)을 이용한다. 이렇게 함으로써 각각의 모듈들에 신경회로망의 인식 능력을 이용하여 로봇 endeffector를 인식하고 좀더 빠른 시간 내에 위치 및 크기를 검출하도록 하는 로봇 endeffector 인식시스템을 구성하도록 하였다. 본 논문에서 제안한 인식 시스템은 잡음에 덜 민감하며 로봇의 endfeector를 인식하는데 좋은 성능을 보임을 알 수 있다. 다중 모듈 신경회로망을 이용한 방법은 기존의 단일 신경회로망보다 14％ 향상된 94％의 인식률을 보이며 원격지에 있는 운영자의 편의를 위해 로봇의 endeffector를 인식하여 화면의 정 중앙에 정확히 위치시킬 수 있다.

• 한국컴퓨터정보학회논문지
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• 제16권12호
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• pp.93-102
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• 2011

본 논문은 야외 환경에서 하나의 카메라를 이용한 시각 장애인을 위한 보행 안내 시스템을 제안한다. 기존의 스테레오 비전을 이용한 보행 지원 시스템과는 다르게 제안된 시스템은 사용자의 허리에 고정된 하나의 카메라를 이용하여 꼭 필요한 정보만을 얻는 것을 목표로 하는 시스템이다. 제안하는 시스템은 먼저 탑-뷰 영상을 생성하고, 생성된 탑-뷰 영상 내 지역적인 코너 극점을 검출한다. 검출된 극점에서 방사형의 히스토그램을 분석하여 장애물을 검출한다. 그리고 사용자 움직임은 사용자에 가까운 지역 안에서 옵티컬 플로우를 사용하여 추정한다. 이렇게 영상으로부터 추출된 정보들을 기반으로 음성 메시지 생성 모듈은 보행 지시 정보를 합성된 음성을 통해 시각 장애인에게 전달한다. 다양한실험 영상들을 사용하여 제안한 보행 안내 시스템이 일반 인도에서 유용한 안내 지시를 제공하는 것이 가능함을 보인다.

• ETRI Journal
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• 제37권6호
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• pp.1143-1153
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• 2015

In this paper, we propose an efficient architecture for a real-time image stitching engine for vision SoCs found in motor vehicles. To enlarge the obstacle-detection distance and area for safety, we adopt panoramic images from multiple telegraphic cameras. We propose a stitching method based on a fixed homography that is educed from the initial frame of a video sequence and is used to warp all input images without regeneration. Because the fixed homography is generated only once at the initial state, we can calculate it using SW to reduce HW costs. The proposed warping HW engine is based on a linear transform of the pixel positions of warped images and can reduce the computational complexity by 90% or more as compared to a conventional method. A dual-core SW/HW image stitching engine is applied to stitching input frames in parallel to improve the performance by 70% or more as compared to a single-core engine operation. In addition, a dual-core structure is used to detect a failure in state machines using rock-step logic to satisfy the ISO26262 standard. The dual-core SW/HW image stitching engine is fabricated in SoC with 254,968 gate counts using Global Foundry's 65 nm CMOS process. The single-core engine can make panoramic images from three YCbCr 4:2:0 formatted VGA images at 44 frames per second and frequency of 200 MHz without an LCD display.

• 한국정보통신학회논문지
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• 제23권9호
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• pp.1088-1095
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• 2019

최근 발전되고 있는 정보통신 IT 기술은 자동차 시장에도 큰 영향을 미치며 발전하고 있다. 근래에는 운전자의 안전성과 편의성을 위해 IT 기술이 접목된 장치들이 장착되고 있다. 하지만 편의성이 증가된 장점과 함께 운전자의 주의 분산으로 인해 교통사고를 증가시키는 단점도 가져오게 되었다. 이러한 사고를 미연에 방지하기 위해 여러 방식과 종류의 안전시스템 개발이 필요하다. 본 논문에서는 두 개 이상의 센서를 이용한 레이더센서 와 카메라 융합 방식 및 Stereo Camera 방식을 이용하지 않고 하나의 단일 Camera를 이용하여 주/야간 차선이탈 경보 및 장애물 및 보행자 인식이 가능한 플랫폼을 구현 하고 차량에서 인식률 평가 및 유효성을 분석 하여 단일 카메라를 이용한 다기능 주행안전 플랫폼 연구를 제안 한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권5호
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• pp.1814-1828
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• 2021

Low-light image enhancement is a key technique to overcome the quality degradation of photos taken under scotopic vision illumination conditions. The degradation includes low brightness, low contrast, and outstanding noise, which would seriously affect the vision of the human eye recognition ability and subsequent image processing. In this paper, we propose an approach based on deep learning and Retinex theory to enhance the low-light image, which includes image decomposition, illumination prediction, image reconstruction, and image optimization. The first three parts can reconstruct the enhanced image that suffers from low-resolution. To reduce the noise of the enhanced image and improve the image quality, a super-resolution algorithm based on the Laplacian pyramid network is introduced to optimize the image. The Laplacian pyramid network can improve the resolution of the enhanced image through multiple feature extraction and deconvolution operations. Furthermore, a combination loss function is explored in the network training stage to improve the efficiency of the algorithm. Extensive experiments and comprehensive evaluations demonstrate the strength of the proposed method, the result is closer to the real-world scene in lightness, color, and details. Besides, experiments also demonstrate that the proposed method with the single low-light image can achieve the same effect as multi-exposure image fusion algorithm and no ghost is introduced.

• 전기학회논문지
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• 제66권7호
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• pp.1117-1122
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• 2017

Pedestrian detection is a very important and valuable part of artificial intelligence and computer vision. It can be used in various areas for example automatic drive, video analysis and others. Many works have been done for the pedestrian detection. The accuracy of pedestrian detection on multiple pedestrian image has reached high level. It is not easily get more progress now. This paper proposes a new structure based on the idea of HOG and convolutional filters to do the pedestrian detection in single pedestrian image. It can be a method to increase the accuracy depend on the high accuracy in single pedestrian detection. In this paper, we use Multiblock HOG and magnitude of the pixel as the feature and use convolutional filter to do the to extract the feature. And then use NEWFM to be the classifier for training and testing. We use single pedestrian image of the INRIA data set as the data set. The result shows that the Convolutional Multiblock HOG we proposed get better performance which is 0.015 miss rate at 10-4 false positive than the other detection methods for example HOGLBP which is 0.03 miss rate and ChnFtrs which is 0.075 miss rate.

• Advances in concrete construction
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• 제17권3호
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• pp.159-165
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• 2024

The interaction of short range zigzag single walled carbon nanotubes CNTs based on modified elasticity model is studied in this paper. The numerical accurate results are presented. Through this model the vibrational frequency of zigzag (5, 0), (12, 0) single-walled CNTs with certain end conditions are estimated. The natural frequencies of single walled carbon nanotubes are obtained by elasticity model. It is considered for various estimation of height-to-diameter ratio of zigzag tube. This simulation is performed to quantify small scale effects. Moreover, the natural frequencies increase by increasing the height-to-diameter ratio. These frequencies are very sensitive with low height-to-diameter ratio. The feasibility and effective use of present model is explained by comparison of outputs of earlier investigations.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권1호
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• pp.12-17
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• 1999

$MgIn_2Se_4 and MgIn_2Se_4 : Ni^{2+}$ single crystals were grown in the rhombohedral structure by the chemical transport reaction (C.T.R.) method using iodine as a transport agent. The optical absorption measured near the fundamental band edge showed that the optical energy band structure of these compounds had a direct band gap. The fundamental absorption band edge of these single crystals shift to a shorter wavelength region by decreasing temperature and the temperature dependence of the optical energy gaps in these compounds satisfy Varshni equation. The impurity optical absorption peaks due to nickel are observed in $MgIn_2Se_4 and MgIn_2Se_4 : Ni^{2+}$ single crystal. These impurity optical absorption peaks can be attributed to the electronic transitions between the split energy levels of $Ni_{2+}$ ions located at $T_d$ symmetry site of $MgIn_2Se_4$ host lattice. In the hotoluminescence spectrum of the single crystal at 10 K, a blue emission with a peak at 687nm and a green emission with a peak at 815nm for the $MgIn_2Se_4$ single crystal were observed.

• 한국운동역학회지
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• 제24권2호
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• pp.111-119
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• 2014

The purpose of this study was to investigate the effects of localized muscle fatigue and whole body fatigue on postural control during single-leg stance after impairment induced by heel raise and the Harvard step test. Thirty-eight university students (19 men: age, $20.1{\pm}0.2$ yrs; height, $175.0{\pm}5.23cm$; weight, $66.8{\pm}5.6kg$; body mass index, $21.8{\pm}1.7kg/m^2$, 19 women: age, $20.6{\pm}1.1yrs$ ; height, $163.6{\pm}6.7cm$; weight, $58.8{\pm}4.6kg$; body mass index, $22.0{\pm}2.2kg/m^2$) were participated in this study. Subjects performed a series of single-leg postural tasks prior to, following, and 24 hours after completing: heel raise or the Harvard step test. This study showed that the root mean squared distance and velocity in the anteroposterior and mediolateral planes of the center of pressure decreased significantly due to heel raise exercise-induced fatigue. Furthermore, the root mean squared distance in the anteroposterior and mediolateral planes, and the 95% confidence ellipse area of the center of pressure also decreased significantly 24 hours after completing the Harvard step test. In conclusion, this study showed that both heel raise exercise- and Harvard step exercise-induced fatigue affects postural control during single-leg stance in AP and ML planes. Furthermore, this study suggests that changes in the postural control strategy may have occurred after the fatigue protocols during single-leg stance. Also vision can attenuate the postural deficits associated with the fatigues. In order to clarify these results, further studies using other equipment and variables are necessary.

• 제어로봇시스템학회논문지
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• 제19권2호
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• pp.164-170
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• 2013

Quadrotor UAV (Unmanned Aerial Vehicle) is a flying robotic platform which has drawn lots of attention in the recent years. The attraction comes from the fact that it is able to perform agile VTOL (Vertical Take-Off Landing) and hovering functions. In addition, the efficient modular structure composed of four electric rotors makes its design easier compared to other single-rotor type helicopters. In many cases, a quadrotor often utilizes vision systems in order to obtain altitude control and navigation solution in hostile environments where GPS receivers are not working or deniable. For carrying out their successful missions, it is essential for flight control systems to have fast and stable control responses of heading angle outputs. This paper presents a Fuzzy Logic based lateral PI controller to stabilize and control the quadrotor vehicle equipped with vision systems. The advantage of using the fuzzy based PI controller lies in the fact that it could acquire a desired output response of a heading angle even in presence of disturbances and uncertainties. The performance comparison of the newly proposed Fuzzy-PI controller and the conventional PI controller was carried out with various simulation results.