• Title/Summary/Keyword: correcting frame

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Structural Analysis for the Collapse Accident of Tower Crane (타워크레인 붕괴사고의 구조적 분석)

  • 이명구;노민래
    • Journal of the Korean Society of Safety
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    • v.16 no.4
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    • pp.147-152
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    • 2001
  • The tower cranes are the very useful construction machine in the high place works. But they are very susceptible to the load balance, the wind load and the hanging load because they are the very slender structures and those center of gravity is located in the upper part. Therefore, the collapse accidents of tower one have repeatedly happened during the assemble or disassemble works. The correcting frame may has often used in order to correct the error in the setting of foundation anchors. The goal of this study is that propose the methods preventible the collapse accident of tower crane which is constructed by using the correcting frame. In order to accomplish the goal of this study, the field survey, the reference investigation and the structure analysis were performed for the collapse accident of tower crane using the correcting frame. This study result in the methods preventible the same accident.

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Robust Digital Watermarking for High-definition Video using Steerable Pyramid Transform, Two Dimensional Fast Fourier Transform and Ensemble Position-based Error Correcting

  • Jin, Xun;Kim, JongWeon
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.7
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    • pp.3438-3454
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    • 2018
  • In this paper, we propose a robust blind watermarking scheme for high-definition video. In the embedding process, luminance component of each frame is transformed by 2-dimensional fast Fourier transform (2D FFT). A secret key is used to generate a matrix of random numbers for the security of watermark information. The matrix is transformed by inverse steerable pyramid transform (SPT). We embed the watermark into the low and mid-frequency of 2D FFT coefficients with the transformed matrix. In the extraction process, the 2D FFT coefficients of each frame and the transformed matrix are transformed by SPT respectively, to produce two oriented sub-bands. We extract the watermark from each frame by cross-correlating two oriented sub-bands. If a video is degraded by some attacks, the watermarks of frames contain some errors. Thus, we use an ensemble position-based error correcting algorithm to estimate the errors and correct them. The experimental results show that the proposed watermarking algorithm is imperceptible and moreover is robust against various attacks. After embedding 64 bits of watermark into each frame, the average peak signal-to-noise ratio between original frames and embedded frames is 45.7 dB.

Realtime Implementation Method for Perspective Distortion Correction (원근 왜곡 보정의 실시간 구현 방법)

  • Lee, Dong-Seok;Kim, Nam-Gyu;Kwon, Soon-Kak
    • Journal of Korea Multimedia Society
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    • v.20 no.4
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    • pp.606-613
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    • 2017
  • When the planar area is captured by the depth camera, the shape of the plane in the captured image has perspective projection distortion according to the position of the camera. We can correct the distorted image by the depth information in the plane in the captured area. Previous depth information based perspective distortion correction methods fail to satisfy the real-time property due to a large amount of computation. In this paper, we propose the method of applying the conversion table selectively by measuring the motion of the plane and performing the correction process by parallel processing for correcting perspective projection distortion. By appling the proposed method, the system for correcting perspective projection distortion correct the distorted image, whose resolution is 640x480, as 22.52ms per frame, so the proposed system satisfies the real-time property.

Design of A Turbo-code Decoder for Speech Transmission in IMT-2000 (IMT-2000에서 음성 전송을 위한 터보 코드 복호기 설계)

  • 강태환;박성모
    • Proceedings of the IEEK Conference
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    • 2000.11b
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    • pp.273-276
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    • 2000
  • Recently, Turbo code has been considered for channel coding in IMT-2000(International Mobile Telecommunication-2000) system, because it offers better error correcting capability than the traditional convolution/viterbi coding . In this paper, a turbo code decoder for speech transmission in IMT-2000 system with frame size 192 bits, constrait length K=3, generator polynomials G(5,7) and code rate R=1/3 is designed using SOVA(Soft Output Viterbi Algorithm) and block interleaver

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The study on the safety inspection system model of the tower crane a construction site in Korea (국내 건설현장 타워크레인 안전진단 관리시스템 모델에 관한 연구)

  • Yeon, In-Soo;Seo, Jang-Hoon;Kang, Kyeong-Sik
    • Proceedings of the Safety Management and Science Conference
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    • 2006.11a
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    • pp.499-507
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    • 2006
  • The tower cranes are widely used in very useful construction machine the sites of constructing high-structure and have a structural sensitiveness. Therefore, the accidents have often happened due to the deficiency of laborer's understanding md lack of safety of structure. Till now, as we have research and studied above, we can properly protect accidents by construction equipments particularly crane as well as most disasters which occur frequently in construction site. The goal of this study is the safety inspection model of the tower crane a construction site, which preventible the collapse accident of tower crane which is constructed by using the correcting frame. In order to accomplish the goal of this study, the field survey, the reference investigation and the structure analysis were performed for the collapse accident of tower nine using the correcting data. This study will be proposed a build-up solutions about operating and release of safety constructions and researched about software safety estimation. Also, preventing safety problems of Tower Crane Construction site as applying safety estimation program and laws and regulations. As a result, The real time control of tower crane inspection system is implemented by to illustrate the application of the adopted optimal design model.

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A Study on the Safety Inspection System Model of The Tower Crane a Construction Site in Korea (국내 건설현장 타워크레인 안전진단 관리시스템 모델에 관한 연구)

  • Yoon, In-Soo;Kang, Kyung-Sik
    • Journal of the Korea Safety Management & Science
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    • v.9 no.1
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    • pp.37-49
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    • 2007
  • The tower cranes are widely used in very useful construction machine the sites of constructing high-structure and have a structural sensitiveness. Therefore, the accidents have often happened due to the deficiency of laborer's understanding and lack of safety of structure. Till now, as we have research and studied above, we can properly protect accidents by construction equipments particularly crane as well as most disasters which occur frequently in construction site. The goal of this study is the safety inspection model of the tower crane a construction site, which preventible the collapse accident of tower crane which is constructed by using the correcting frame. In order to accomplish the goal of this study, the field survey, the reference investigation and the structure analysis were performed for the collapse accident of tower crane using the correcting data. This study will be proposed a build-up solutions about operating and release of safety constructions and researched about software safety estimation. Also, preventing safety problems of Tower Crane Construction site as applying safety estimation program and laws and regulations. As a result, The real time control of tower crane inspection system is implemented by to illustrate the application of the adopted optimal design model.

Correction of Rotated Frames in Video Sequences Using Modified Mojette Transform (변형된 모젯 변환을 이용한 동영상에서의 회전 프레임 보정)

  • Kim, Ji-Hong
    • Journal of Korea Multimedia Society
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    • v.16 no.1
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    • pp.42-49
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    • 2013
  • The camera motion is accompanied with the translation and/or the rotation of objects in frames of a video sequence. An unnecessary rotation of objects declines the quality of the moving pictures and in addition is a primary cause of the viewers' fatigue. In this paper, a novel method for correcting rotated frames in video sequences is presented, where the modified Mojette transform is applied to the motion-compensated area in each frame. The Mojette transform is one of discrete Radon transforms, and is modified for correcting the rotated frames as follows. First, the bin values in the Mojette transform are determined by using pixels on the projection line and the interpolation of pixels adjacent to the line. Second, the bin values are calculated only at some area determined by the motion estimation between current and reference frames. Finally, only one bin at each projection is computed for reducing the amount of the calculation in the Mojette transform. Through the simulation carried out on various test video sequences, it is shown that the proposed scheme has good performance for correcting the rotation of frames in moving pictures.

Algorithm for Correcting Error in Smart Card Data Using Bus Information System Data (버스정보시스템 데이터를 활용한 교통카드 정류장 정보 오류 보정 알고리즘)

  • Hye Inn Song;Hwa Jeong Tak;Kang Won Shin;Sang Hoon Son
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.22 no.3
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    • pp.131-146
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    • 2023
  • Smart card data is widely used in the public transportation field. Despite the inevitability of various errors occur during the data collection and storage; however, smart card data errors have not been extensively studied. This paper investigates inherent errors in boarding and alighting station information in smart card data. A comparison smart card data and bus boarding and alighting survey data for the same time frame shows that boarding station names differ by 6.2% between the two data sets. This indicates that the error rate of smart card data is 6.2% in terms of boarding station information, given that bus boarding and alighting survey data can be considered as ground truth. This paper propose 6-step algorithm for correcting errors in smart card boarding station information, linking them to corresponding information in Bus Information System(BIS) Data. Comparing BIS data and bus boarding and alighting survey data for the same time frame reveals that boarding station names correspond by 98.3% between the two data sets, indicating that BIS data can be used as reliable reference for ground truth. To evaluate its performance, applying the 6-step algorithm proposed in this paper to smart card data set shows that the error rate of boarding station information is reduced from 6.2% to 1.0%, resulting in a 5.2%p improvement in the accuracy of smart card data. It is expected that the proposed algorithm will enhance the process of adjusting bus routes and making decisions related to public transportation infrastructure investments.

Wyner-Ziv Video Compression using Noise Model Selection (잡음 모델 선택을 이용한 Wyner-Ziv 비디오 압축)

  • Park, Chun-Ho;Shim, Hiuk-Jae;Jeon, Byeung-Woo
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.46 no.4
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    • pp.58-66
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    • 2009
  • Recently the emerging demands of the light-video encoder promotes lots of research efforts on DVC (Distributed Video Coding). As an appropriate video compression method, DVC has been studied, and Wyner-Ziv (WZ) video compression is its one representative structure. The WZ encoder splits the image into two kinds of frames, one is key frame which is compressed by conventional intra coding, and the other is WZ frame which is encoded by WZ coding. The WZ decoder decodes the key frame first, and estimates the WZ frame using temporal correlation between key frames. Estimated WZ frame (Side Information) cannot be the same as the original WZ frame due to the absence of the WZ frame information at decoder. As a result, the difference between the estimated and original WZ frames are regarded as virtual channel noise. The WZ frame is reconstructed by removing noise in side information. Therefore precise noise estimation produces good performance gain in WZ video compression by improving error correcting capability by channel code. But noise cannot be estimated precisely at WZ decoder unless there is good WZ frame information, and generally it is estimated from the difference of corresponding key frames. Also the estimated noise is limited by comparing with frame level noise to reduce the uncertainty of the estimation method. However these methods cannot provide good noise estimation for every frame or each bit plane. In this paper, we propose a noise nodel selection method which chooses a better noise model for each bit plane after generating candidate noise models. Experimental result shows PSNR gain up to 0.8 dB.

Mobile Watermarking Based on the Distortion Analysis of Display-Capture Image in a Smart Phone (스마트폰에서 디스플레이-캡쳐 영상의 왜곡분석에 기반한 모바일 워터마킹)

  • Bae, Jong-Wook;Jung, Sung-Hwan
    • Journal of Korea Multimedia Society
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    • v.15 no.7
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    • pp.847-858
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    • 2012
  • In this paper, we propose a mobile watermarking based on the distortion analysis of display-capture image in a smart phone. We compose a random sequence by utilizing the property of frequency band in the wavelet domain. Then we calculate the CCS (Coefficients Comparative Sum) using the block wavelet coefficients of selected subbands after the wavelet transformation and the random sequence and repeatedly embed a watermark using an insertion threshold for the watermark robustness. For correcting a distortion caused by the display-capture process, we adopt a frame at the outside of watermarked image, then we can equate a watermark synchronization by detecting the frame. And we can improve frame detection ratio by using an iteratively adaptive threshold. A proposed scheme embedded information of 206 bits into standard digital images and it shows an average about 41.42 dB in PSNR. In watermark extract experiments, a proposed scheme accurately recognizes the frame more than 97% in total captured images. Also in BER (Bit Error Ratio) of captured images, it shows about 3.73%, then it was improved more than 70%, compared with the Pramila's method.