• Title/Summary/Keyword: cross region

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Adaptive Cross-Coupling Control System Considering Cutting Effects (절삭효과를 고려한 적응 교차축 연동제어 시스템)

  • Ji, Seong-Cheol;Yu, Sang-Pil
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.8
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    • pp.1480-1486
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    • 2002
  • In this study, the cross-coupling control (CCC) with three new features is proposed to maintain contour precision in high-speed nonlinear contour machining. One is an improved contour error model that provides almost exact calculation of the errors. Another is the utilization of variable controller gains based on the instantaneous curvature of the contour and the variable command. For this scheme, a stability is analyzed. As a result, the stability region is obtained, and the variable gains are decided within that region. The other scheme in the proposed CCC is a real-time feedrate adaptation module to regulate cutting force fur better surface finish through regulation of material removal rate (MRR). The simulation results show that the proposed CCC system can provide better precision than the existing method particularly in high-speed machining of nonlinear contours.

Repetitive Homologous Sequences in Flanking Region of Gametophytic Self-Incompatibility Allele in Lycopersicon peruvianum

  • Chung, II-Kyung
    • BMB Reports
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    • v.30 no.1
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    • pp.18-20
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    • 1997
  • Lycopersicon peruvianum shows a gametophytic self-incompatibility (GSI). GSI is controlled by a single locus (S locus) with multiple alleles. S ribonucleases encoded in S alleles cosegregate with their phenotypes of GSI in genetic cross. To understand the genetic role of S allele in L peruvianum, two large genomic fragments isolated previously were analyzed with total genomic DNAs from several tomato lines generated by cross-pollination. Southern blot analysis with the S allele fragments as probes revealed that the flanking region of S allele contained the highly homologous regions. It is speculated that they may play an important role to prevent genetic cross by self-pollination.

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3D Surface Approximation to Serial 2D Cross Sections (단면정보로부터 3차원 근사곡면의 생성)

  • 박형준;김광수
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1994.10a
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    • pp.719-724
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    • 1994
  • This paper describes a hybrid surface-based method for smooth 3D surface approximation to a sequence of 2D cross sections. The resulting surface is a hybrid G $^{1}$ surface represented by a mesh of triangular and rectangular Bezier patches defined on skinning, branching, or capping regions. Each skinning region is approximated with a closed B_spline surface, which is transformed into a mesh of Bezier patches. Triangular G $^{1}$ surfaces are constructed over brabching and capping regions such that the transitions between each capping regions such that the transitions between each triangular surface and its neighboring skinning surfaces are G $^{1}$ continuous. Since each skinning region is represented by an approximated rectangular C $^{2}$ suface instead of an interpolated trctangular G $^{[-1000]}$ surface, the proposed method can provide more smooth surfaces and realize more efficient data reduction than triangular surfacebased method.

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Numerical Investigation of the Flow Pulsation in the Gap connecting with Two Parallel Channels with Different Cross-section Areas (크기가 다른 단면을 가진 평행한 두 채널을 연결하는 협소유로의 맥동유동에 관한 수치해석)

  • Seo, Jeong-Sik;Hong, Seong-Ho;Shin, Jong-Kuen;Choi, Young-Don
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.2810-2815
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    • 2008
  • Flow pulsation in the gap connecting with two parallel channels is investigated by RANS and URANS approaches. The two parallel channels are connected by a small channel called for a gap. The parallel channels are designed to have different cross section area with its ratio of 0.5. Computations are conducted using a CFX 11.0 code. The bulk Reynolds number is 60,000. Predicted results are compared with the previous experimental result. Mean velocity profile at the center of gap region are compared with experiments for its validation. Spectral analysis on the lateral velocity in the center of the gap is presented. Auto and cross correlation for the axial-flow velocity pattern are presented. The unsteady structure of the flow pulsation was visualized in the region of the gap in the parallel channel.

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Composite $G^{1}$ surface construction from 2D cross-sections (2차원 단면 데이터로부터 복합 $G^{1}$ 자유곡면 생성)

  • Park, Hyung-Jun;Na, Sang-Wook;Bae, Chae-Yeol
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2004.05a
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    • pp.44-47
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    • 2004
  • This paper proposes an approach for composite surface reconstruction from 2D serial cross-sections, where the number of contours varies from section to section. In a triangular surface-based approach taken in most reconstruction methods, a triangular $G^{1}$ surface is constructed by stitching triangular patches over a triangular net generated from the compiled contours. In the proposed approach, the resulting surface is a composite $G^{1}$ surface consisting of three kinds of surfaces: skinned, surface is first represented by a B-spline surface approximating the serial contours of the skinned region and then serial contours of the skinned region and then transformed into a mesh of rectangular Bezier patches. On branched and capped regions, triangular $G^{1}$ surfaces are constructed so that the connections between the triangular surfaces and their neighboring surfaces are $G^{1}$ continuous. Since each skinned region is represented by an approximated rectangular $G^{2}$ surface instead of an interpolated triangular $G^{1}$ surface, the proposed approach can provide more visually pleasing surfaces and realize more efficient data reduction than the triangular surface-based approach. Some experimental results demonstrate its usefulness and quality.

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Effect of Different Seasons on Cross-Bred Cow Milk Composition and Paneer Yield in Sub-Himalayan Region

  • Sharma, R.B.;Kumar, Manish;Pathak, V.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.4
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    • pp.528-530
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    • 2002
  • The study was designed to evaluate the seasonal influences on cross-bred cow milk composition and paneer yield in Dhauladhar mountain range of sub-himalayan region. Fifty samples from each season were collected from a herd of $Jersey{\times}Red\;Sindhi{\times}Local$ cross-bred cows during summer (April-June), rainy (July-September) and winter (November-February) and analyzed for fat, total solids (TS) and solids not fat (SNF). Paneer was prepared by curdling milk at $85{\pm}2^{\circ}C$ with 2.5 per cent citric acid solution. Overall mean for fat, TS and SNF content of milk and paneer yield were 4.528, 13.310, 8.754 and 15.218 per cent respectively. SNF and TS content varied among seasons being highest in winter (8.983% and 13.639%) followed by summer (8.835% and 13.403%) and lowest in rainy season (8.444% and 12.888%). Paneer yield was lowest (14.792%) in rainy season and highest (15.501%) in winter season.

Study of Optical Tomography for Measurement of Spray Characteristics at High Ambient Pressure (고압 환경에서의 분무 특성 계측을 위한 광학 토모그래피 기법 연구)

  • Cho, Seong-Ho;Im, Ji-Hyuk;Choi, Ho-Yeon;Yoon, Young-Bin
    • Journal of the Korean Society of Propulsion Engineers
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    • v.13 no.4
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    • pp.36-44
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    • 2009
  • Spray cross-section was measured by the Optical Line Patternator (OLP) and Optical Tomography at high ambient pressure. The laser line beam passed through the spray region, then Mie scattered signal and transmitted light were captured. The measured signal was processed to obtain a distribution of attenuation coefficient in spray cross-section. Beer-Lambert's law and mathematical reconstruction methods were used to reconstruct the distribution of attenuation coefficient. Spray became dense at high pressure and attenuation of scattered signal occurred seriously. OLP method, which uses Mie scattered signal, showed limit in compensating attenuation problem in dense spray region. Optical tomography reconstructed spray cross-section well, from transmission rate of light penetrating spray region.

An Adaptive Occluded Region Detection and Interpolation for Robust Frame Rate Up-Conversion

  • Kim, Jin-Soo;Kim, Jae-Gon
    • Journal of information and communication convergence engineering
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    • v.9 no.2
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    • pp.201-206
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    • 2011
  • FRUC (Frame Rate Up-Conversion) technique needs an effective frame interpolation algorithm using motion information between adjacent neighboring frames. In order to have good visual qualities in the interpolated frames, it is necessary to develop an effective detection and interpolation algorithms for occluded regions. For this aim, this paper proposes an effective occluded region detection algorithm through the adaptive forward and backward motion searches and also by introducing the minimum value of normalized cross-correlation coefficient (NCCC). That is, the proposed scheme looks for the location with the minimum sum of absolute differences (SAD) and this value is compared to that of the location with the maximum value of NCCC based on the statistics of those relations. And, these results are compared with the size of motion vector and then the proposed algorithm decides whether the given block is the occluded region or not. Furthermore, once the occluded regions are classified, then this paper proposes an adaptive interpolation algorithm for occluded regions, which still exist in the merged frame, by using the neighboring pixel information and the available data in the occluded block. Computer simulations show that the proposed algorithm can effectively classify the occluded region, compared to the conventional SAD-based method and the performance of the proposed interpolation algorithm has better PSNR than the conventional algorithms.

Measurement of Turbulent Flows in a Square Sectioned $270^{\circ}$ Bend (열선 유속계에 의한 정사각형 단면의 270도 곡관에서의 난류유동 특성에 관한 연구)

  • Cho, Sok-Hyu;Chun, Kun-Ho;Lee, Gun-Hyee
    • Proceedings of the KSME Conference
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    • 2000.11b
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    • pp.467-472
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    • 2000
  • Most of the past experimental or analytical studies were performed for the curved bend with a square cross-section. Velocity profiles and Reynolds stresses of the turbulence flow in the 270 degree bend with circular cross-section were measured by a hot-wire anemometer. The mean velocity of primary flowing direction effected by the downstream of bend in the entry region of the bend. The flow in the inner part of the bend slowed the distribution velocity relatively large and unsymmetric phenomenon. In the strong secondary flow occurred when the flow passed in the region of 45 degree to 90 degree. The secondary flow appeared very large value in the neighbor region of inner wall.

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Inductance Analysis of Interior Permanent Magnet Synchronous Motor Considering Cross-Coupling Effect (교차 결합 현상을 고려한 매입형 영구자석 전동기의 인덕턴스 특성 해석)

  • Kwak, Sang-Yeop;Kim, Jae-Kwang;Jung, Hyun-Kyo;Lee, Sang-Yub
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.55 no.4
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    • pp.189-195
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    • 2006
  • In this paper, the inductance characteristics of interior permanent magnet synchronous motor (IPMSM) considering cross-coupling effect is analyzed. It is known that the IPMSM has it's operating point at the saturated region. So the cross-coupling effect exists, therefore cross-coupling inductance exists. With the application of Fixed Permeability Method (FPM), we can obtain more exact inductance characteristics of IPMSM. In this paper, a novel method based on the FPM is proposed, which can consider the cross-coupling effect. And the cross-coupling inductance which is the analysis result is shown. Finally, the validity of proposed method is verified by the comparison with the experimental result.