• Title/Summary/Keyword: shape distortion

Search Result 350, Processing Time 0.022 seconds

A Study on Automation of Steel Plate Forming by Heating Method (열간가공에 의한 강판의 곡 가공 자동화 시스템)

  • B.I. Lee;H.S. Yoo;G.G. Byun;H.G. Kim
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.39 no.2
    • /
    • pp.34-44
    • /
    • 2002
  • Approximately 70 percent of shop's hull plate consists of three-dimensional curved shell. Concerning with the research on the automation of plate forming many studies have been carried out for the last decade. The purpose of this study is to develop the simulator of heating on the basis of the reasonable mechanical model representing a heating phenomenon. The beating experiment has been carried out with varying parameters influencing on the results of heating information at the kinematics analysis, simulatorestimate the shape of deformed plate that process along the processing information. When we get the initial shape and the object shape, we calculate the processing information first, using kinematics analysis. In a simulator we estimate deformed shape from the processing information. After this we compare deformed shape and object shape. If the error of deformed shape and object shape is in the proper limits, that information is determined the final processing information. Else we repeat the process changing variable.

Power Factor Correction Technique of Boost Converter Based on Averaged Model (평균화 모델을 이용한 역률개선 제어기법)

  • 정영석;문건우;이준영;윤명중
    • Proceedings of the KIPE Conference
    • /
    • 1996.06a
    • /
    • pp.85-88
    • /
    • 1996
  • New power factor correction(PFC) technique based on the averaged model of boost converter is proposed. Without measurement of input current, power factor correction scheme derived from the averaged model is presented. With the measurements of input voltage and output voltage, the control signal is generated to make the shape of the line current same as the input voltage. The characteristics of input line current distortion is analyzed by considering the generation of duty cycle.

  • PDF

Analysis of Propagation Characteristics in Microstriplines Using the FDTD (FDTD를 사용한 마이크로스트립라인 전파특성 해석)

  • 류종인;김용진;박영태;이상설
    • Proceedings of the IEEK Conference
    • /
    • 1999.06a
    • /
    • pp.869-872
    • /
    • 1999
  • As integrated circuits are developed, the crosstalk and the pulse distortion have been major problems in the design. In this paper. the PML and one-point resistive source are applied. This paper deal with the microstripline circuit which has the gap and three microstripline. Obtaining the Propagation pulse shape in microstripline, we prove that the use of the FDTD in the microstripline is valid.

  • PDF

Implementation of SA-DCT using a datapath (데이터패스를 이용한 SA-DCT 구현)

  • 박주현;김영민
    • Journal of the Korean Institute of Telematics and Electronics C
    • /
    • v.35C no.5
    • /
    • pp.25-32
    • /
    • 1998
  • In this paper, SA (shape adaptive)-DCT is implemented using a datapath with 4 MACs (multiplication & accumulator). DCT is a well-known bottleneck of real-time video compression using MPEG-like schemes. High-speed pipelined MACs presented here implement real-time DCT. A datapath in this paper executes DCT/IDCT algorithms for QCIF 15fps(frame per second), maximum rate of VLBV(very low bitrte video) in MPEG-4. A 32bit accumulator in a MAC prevents distortion caused by fixed-point process. It can be applied to various operations such as ME (motion estimation) and MC(motion compensation) with a absolutor and a halfer.

  • PDF

The Impact of Signal Intensity and Image Distortion Magnetic Resonance Imaging in the Orthopedic Prosthetic Metal (자기공명영상에서 정형보철 금속이 신호강도와 영상왜곡에 미치는 영향)

  • Kim, Hyeong-Gyun;Choi, Seong-Dae
    • Journal of radiological science and technology
    • /
    • v.35 no.4
    • /
    • pp.321-326
    • /
    • 2012
  • Used as an ingredient in the hospital for orthopedic prosthetic stainless and titanium metal the same size as on the MRI diagnostic value of imaging were compared. Center of images, background high band portion of the video signal is converted into a weighted intensity values Normal images and compared. The area of normal slice and also the distortion of images and cross-sectional imaging of a range of quantitative and sagittal planes were compared. As a result, the periphery high band signal intensity values of Stainless video phantom 2, pig bone 1.8, Titanium imaging of phantom 1.7 has higher value than Normal video pig bone 1.3 times the signal strength rivers. MRI distortion of the shape and the distortions of the range, if the cross-sectional area compared to Normal Slice Stainless case of phantom 65.8 %, pig bone 61.5 %, Titanium distortion phantom 23.1 %, pig bone 38.5 % of the range of community found. In this experiment, as a result, MRI was found to be Titanium more diagnostic value than the specimen with respect to the signal intensity weighted value and low distortion range, Stainless.

Baseline based Binary Shape Coder (기준선 기반 이진 형상 부호화기)

  • 이시화;조대성;조유신;손세훈;장의선;신재섭;서양석
    • Journal of Broadcast Engineering
    • /
    • v.2 no.2
    • /
    • pp.114-124
    • /
    • 1997
  • In object based coding, binary shape ccx:ling plays an important role by ccx:ling the outer shape of object. Here we propose a new shape ccx:ling tool, which enccx:les the outline of shape from a baseline. Different from 2-D (Vertex) shape ccx:ling algorithms. the proposed method encodeds the data that are extracted in a I-D fashion. The enccx:led data consist of the starting position, distance lists, and turning point lists. In the lossless ccx:ling mode, every contour pixel is input for ccx:ling, whereas variable sampling has been employed to enccx:le fewer contour pixels while preserving reasonable distortion. For interframe ccx:ling, a fast motion compensation was achieved by use of distance and turning point lists. Subjective viewing tests proved that the proposed method outperforms the current shape ccx:ling standard, CAE, in MPEG-4. In objective results for compression efficiency, the proposed method was significantly better in intraframe coding than CAE, whereas CAE was better in interframe ccx:ling.

  • PDF

A 3-D Tube Reconstruction based on Axis Alignment of Multiple Laser Scanning (배관측 정렬 방법을 이용한 다중레이저 스캐닝 기반의 3차원 배관복원)

  • Baek, Seung-Hae;Park, Soon-Yong;Kim, Seung-Ho
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.17 no.11
    • /
    • pp.1159-1167
    • /
    • 2011
  • A novel 3D tube scanning technique is proposed. The proposed tube scanning technique is developed for a special tube inspection module which consists of four line-lasers and one camera. Using the scanning module, we can reconstruct the 360 degree shapes of the inner surfaces of a cylindrical tube. From an image frame captured by the camera, we reconstruct a partial tube model based on four laser triangulations. Then by aligning such partial models with respect to a reference tube axis, a complete 3D shape of the tube is reconstructed. The tube axis in each reconstructed frame is aligned with a 3D Euclidean transformation to the reference axis. Several experiments show that the proposed method can align multiple tube axes very accurately and reconstruct 3D shapes of a tube with very low shape distortion.

Adaptive Image Watermarking Using a Stochastic Multiresolution Modeling

  • Kim, Hyun-Chun;Kwon, Ki-Ryong;Kim, Jong-Jin
    • Proceedings of the IEEK Conference
    • /
    • 2002.07a
    • /
    • pp.172-175
    • /
    • 2002
  • This paper presents perceptual model with a stochastic rnultiresolution characteristic that can be applied with watermark embedding in the biorthogonal wavelet domain. The perceptual model with adaptive watermarking algorithm embed at the texture and edge region for more strongly embedded watermark by the SSQ(successive subband quantization). The watermark embedding is based on the computation of a NVF(noise visibility function) that have local image properties. This method uses non-stationary Gaussian model stationary Generalized Gaussian model because watermark has noise properties. In order to determine the optimal NVF, we consider the watermark as noise. The particularities of embedding in the stationary GG model use shape parameter and variance of each subband regions in multiresolution. To estimate the shape parameter, we use a moment matching method. Non-stationary Gaussian model use the local mean and variance of each subband. The experiment results of simulation were found to be excellent invisibility and robustness. Experiments of such distortion are executed by Stirmark benchmark test.

  • PDF

Optimization of the Permanent Magnet Shape in Moving Magnet Type Permanent Magnet Linear Synchronous Motor (Moving Magnet Type PMLSM의 영구자석 형상 최적화)

  • Lee, Dong-Yeup;Kim, Gyu-Tak
    • Proceedings of the KIEE Conference
    • /
    • 2006.04b
    • /
    • pp.121-123
    • /
    • 2006
  • In this paper, the notch of teeth and skew of permanent magnet are used to reduce the detent force caused by slot-teeth structure. Also, the shape of permanent magnet is optimized to reduce the detent forceowing to flux hannonics components of permanent magnet. As a result, thrust is decrease about 2[%]. But, the distortion ratio of thrust is decreased from 1.04[%] to 0.75[%]. And, the ripple ratio of thrust is decreased from 2.6[%] to 1.65[%].

  • PDF

Efficient Aerodynamic Computation of a Wing Model Considering Body Effect for the Aeroelastic Application

  • Lee, Seung-Jun;Im, Dong-Kyun;Lee, In
    • International Journal of Aeronautical and Space Sciences
    • /
    • v.10 no.1
    • /
    • pp.14-19
    • /
    • 2009
  • The typical aeroelastic analysis for a complex configuration such as a complete aircraft was done using the aerodynamic results of the wing and the structural modes of a complete aircraft; that is, the aerodynamics of a wing of a complete aircraft is assumed to be not much influenced by the body shape. Nevertheless, the body shape can cause a distortion of aerodynamic pressure on the wing surface and it is necessary to investigate the body effect in flutter analysis. In this reseasrch, MGM inverse design method is applied to include the body effect of a wing-body model which disturbs the pressure distribution on the wing surface.