• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.137-140
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• 2010

본 연구에서는 일상생활에서 보다 편리하게 건강모니터링을 수행하기 위해 신체에 착용 가능한 심전도 및 맥파 계측 시스템을 구현하고자 하였다. 이를 위하여 배터리로 구동 가능한 초소형의 심전도 및 맥파 측정 시스템을 구현하였으며, 계측된 생체신호의 무선전송을 위해 초저전력 무선 센서네트워크 기술을 적용한 무선 생체신호 전송시스템을 구현하였다. 무선으로 전송된 심전도 및 맥파 신호는 잡음 제거 및 심박동을 검출하기 위하여 전처리과정과 적응 가변형 문턱치를 적용하였으며, 검출된 심박동으로부터 동맥순환계의 긴장도 및 유순도의 변화를 반영하는 맥파전달시간(pulse transit time, PTT)을 계산하였다. 구현된 무선 맥파전달시간 계측시스템과 기존 상용시스템의 비교 평가를 수행함으로써 구현된 시스템의 유용성을 평가하고자 하였으며, 혈압 및 맥파전달시간의 동시계측을 통해 자세 변화에 따른 혈압의 변화 및 맥파전달시간의 변화양상을 관찰함으로써 혈압과 맥파전달시간의 관계를 추정하고자 하였다.

• Journal of KIISE:Software and Applications
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• v.27 no.3
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• pp.241-247
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• 2000

In this paper, a fast change detection is proposed for sequence image. The proposed method enhances the quality of the change detection mask and the speed of the change detection by combining block based method and pixel based method. Firstly, change regions are detected for 16 ${\times}$ 16 blocks in image. And 16 ${\times}$ 16 contour block of change detection mask is divided into 4 subblocks. Finally, for divided 8 ${\times}$ 8 blocks, contour blocks are extracted and then, the pixel-based change regions are detected for them. As this makes use of the block based method, this not only enhances the speed of the change detection, but also reduces effects of noise in change detection mask. Experimental results show not only the improvement of the separated change/non-change region, but also the improvement of the speed.

• The KIPS Transactions:PartB
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• v.11B no.3
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• pp.317-326
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• 2004

This paper presents a new method for the detection of multiple pedestrians and tracking of a specific pedestrian using color information from a moving camera. We first extract motion vector on the input image using BMA. Next, a difference image is calculated on the basis of the motion vector. The difference image is converted to a binary image. The binary image has an unnecessary noise. So, it is removed by means of the proposed noise deletion method. Then, we detect pedestrians through the projection algorithm. But, if pedestrians are very adjacent to each other, we separate them using RGB color information. And we track a specific pedestrian using RGB color information in center region of it. The experimental results on our test sequences demonstrated the high efficiency of our approach as it had shown detection success ratio of 97％ and detection failure ratio of 3％ and excellent tracking.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.8
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• pp.1553-1559
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• 2017

This paper proposes a lane departure detection algorithm using a single camera equipped in front of a vehicle. The proposed algorithm generates a partial top-view image for a small ROI (region of interest) designated on the top-view space form the image acquired by the camera, detects lanes on the small partial top-view image, and makes a decision on the lane departure by checking overlap between the pre-assigned virtual vehicle and the detected lanes. The proposed algorithm also includes the removal of lines occurred by road symbols (noises) disturbing the lane departure detection between lanes and the prediction of lost lanes using lane information of previous fames. In lane departure detection test using real road videos, the proposed algorithm makes the right decision of 99.0% in lane keeping conditions and 94.7% in lane departure conditions.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.7
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• pp.1332-1337
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• 2006

In this paper, a noble second stage hetero-estimator is used for positioning error detection in mobile robot. Previous methods are either expensive in the case of positioning error correction or not able to detect positioning error. To overcome the latter shortage, the positioning error detection is performed using second stage hetero-estimator in motor model of mobile robot without any additional costs. A Kalman filter in the estimator gets the residual of motor current and an adaptive self-tunning filter checks the whiteness of the residual. Some simulation results show the possibility of the proposed method.

• The Journal of the Acoustical Society of Korea
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• v.28 no.7
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• pp.674-679
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• 2009

This paper proposes a method of player event retrieval using combination of two functions: detection of player name in speech information and detection of sound event from audio information in golf videos. The system consists of indexing module and retrieval module. At the indexing time audio segmentation and noise reduction are applied to audio stream demultiplexed from the golf videos. The noise-reduced speech is then fed into speech recognizer, which outputs spoken descriptors. The player name and sound event are indexed by the spoken descriptors. At search time, text query is converted into phoneme sequences. The lists of each query term are retrieved through a description matcher to identify full and partial phrase hits. For the retrieval of the player name, this paper compares the results of word-based, phoneme-based, and hybrid approach.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.1822-1825
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• 2015

본 논문에서는 운동 전후 또는 심장 질환과 관련 있는 사용자가 체중을 측정하면서 동시에 심전도 신호를 측정하여 운동 부하에 따른 심장의 활동 상태를 모니터링 할 수 있는 장치를 고안하였다. 이를 위한 방법으로 체중계에 수정된 바이폴라 금속전극을 적용하여 표준사지 측정법을 이용하여 심장활동 신호를 측정할 수 있는 방법을 제안하였다. 체중계에서 심전도를 측정하기 위해 기존의 Ag-AgCl 전극이 아닌 금속 판 형태의 전극을 사용하였으며 이를 위해 입력 임피던스의 설계를 브릿지 형의 AC-Coupling 회로를 통해 높은 CMRR이 유지되도록 설계하였다. 또한 시시각각 변화하는 노이즈를 제거하기 위해 Savitzky-golay filter를 사용하였으며 이를 통해 Baseline wandering 이 제거된 최종 심장활동 신호를 획득하였다. R-peak 검출을 통해 기준신호와의 심박수 및 Sensitivity의 비교평가를 수행하여 이 장치의 성능을 평가한 결과 심박 검출률의 평균 Sensitivity가 97.1%로 나타났다. 동잡음 제거에 대한 알고리즘이 보다 최적화 되어 최종 출력 신호의 안정성이 향상 된다면 체중계를 통한 심박 검출의 가능성과 그 유효성이 충분할 것으로 사료된다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.2C
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• pp.262-271
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• 2004

There are channel errors when video data are transmitted between encoder and decoder. These channel errors would make decoded image incorrect, so it is very important to detect and recover channel errors. This paper proposes a method of error detection and recovery by hiding specific information into video bitstream using fragile watermark and checking it later. The proposed method requires no additional bits into compressed bitstream since it embeds a user-specific data pattern in the least significant bits of LEVELs in VLC codewords. The decoder can extract the information to check whether the received bitstream has an error or not. We also propose to use this method to embed essential data such as motion vectors that can be used for error recovery. The proposed method can detect corrupted MBs that usually escape the conventional syntax-based error detection scheme. This proposed method is quite simple and of low complexity. So the method can be applied to multimedia communication system in low bitrate wireless channel.

• The KIPS Transactions:PartB
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• v.10B no.2
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• pp.189-196
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• 2003

This paper describes an error resilient video data transmission method using information hiding. In order to localize transmission errors in receiver, video encoder embeds one bit for a macro block during encoding process. Embedded information is detected during decoding process in the receiver, and the transmission errors can be localized by comparing the original embedding data. The localized transmission errors can be easily corrected, thus the degradation in a reconstructed image can be alleviated. Futhermore, the embedded information can be applied to protect intellectual property rights of the video data. Experimental results for 3 QCIF sized video sequenced composed of 150 frames respectively show that, while degradation in video streams in which the information is embedded is negligible, especially in a noisy channel, the average PSNR of reconstructed images can be improved about 5 dB by using embedded information. Also, intellectual property rights information can be effectively obtained from reconstructed images.

• Journal of Convergence for Information Technology
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• v.11 no.11
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• pp.31-37
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• 2021

In this paper, we propose an outlier detection algorithm called C-SCGP to prevent the degradation of localization performance based on RSS (Received Signal Strength) and AOA (Angle of Arrival) in the presence of outliers in wireless sensor networks. Since the accuracy of target estimation can significantly deteriorate due to various cause of outliers such as malfunction of sensor, jamming, and severe noise, it is important to detect and filter out all outliers. The single cluster graph partitioning (SCGP) algorithm has been widely used to remove such outliers. The proposed continuous-SCGP (C-SCGP) algorithm overcomes the weakness of the SCGP that requires the threshold and computing probability of outliers, which are impratical in many applications. The results of numerical simulations show that the performance of C-SCGP without setting threshold and probability computation is the same performance of SCGP.