• Title/Summary/Keyword: Z변환

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A Study on Improvement of Face Recognition Rate with Transformation of Various Facial Poses and Expressions (얼굴의 다양한 포즈 및 표정의 변환에 따른 얼굴 인식률 향상에 관한 연구)

  • Choi Jae-Young;Whangbo Taeg-Keun;Kim Nak-Bin
    • Journal of Internet Computing and Services
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    • v.5 no.6
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    • pp.79-91
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    • 2004
  • Various facial pose detection and recognition has been a difficult problem. The problem is due to the fact that the distribution of various poses in a feature space is mere dispersed and more complicated than that of frontal faces, This thesis proposes a robust pose-expression-invariant face recognition method in order to overcome insufficiency of the existing face recognition system. First, we apply the TSL color model for detecting facial region and estimate the direction of face using facial features. The estimated pose vector is decomposed into X-V-Z axes, Second, the input face is mapped by deformable template using this vectors and 3D CANDIDE face model. Final. the mapped face is transformed to frontal face which appropriates for face recognition by the estimated pose vector. Through the experiments, we come to validate the application of face detection model and the method for estimating facial poses, Moreover, the tests show that recognition rate is greatly boosted through the normalization of the poses and expressions.

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A Design of the New Three-Line Balun (새로운 3-라인 발룬 설계)

  • 이병화;박동석;박상수
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.14 no.7
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    • pp.750-755
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    • 2003
  • This paper proposes a new three-line balun. The equivalent circuit of the proposed three-line balun is presented, and impedance matrix[Z]of the equivalent circuit is derived from the relationship between the current and voltage at each port. The design equation for a given set of balun impedance at input and output ports is presented using[S]parameters, which is transferred fom impedance matrix,[Z]. To demonstrate the feasibility and validity of design equation, multi-layer ceramic(MLC) chip balun operated in the 2.4 GHz ISM band frequency is designed and fabricated by the use of the low temperature co-fired ceramic(LTCC) technology. By employing both the proposed new three-line balun equivalent circuit and multi-layer configuration provided by LTCC technology, the 2012 size MLC balun is realized. Measured results of the multi-layer LTCC three-line balun match well with the full-wave electromagnetic simulation results, and measured in band-phase and amplitude balances over a wide bandwidth are excellent. This proposed balun is very easily applicable to multi-layer structure using LTCC as shown in the paper, and also can be realized with microstrip lines on PCB. This distinctive performance is very favorable for wireless communication systems such as wireless LAN(Local Area Network) and Bluetooth applications.

Design of a 5.8 GHz Broad Band-Pass Filter with Second of Harmonics Suppression Using the Open Stubs (2차 고조파가 억제된 5.8 GHz 광대역 개방형 스터브 대역 통과 여파기 설계)

  • Choi, Young-Gu;Kim, Bok-Ki
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.18 no.10
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    • pp.1107-1116
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    • 2007
  • In this paper, a broadband open stubs band pass filters which can suppress the second harmonics using Z-transform technique, is designed, fabricated and characterized. The proposed broadband filters integrate the band stop filter with the FSCS structure and ${\lambda}_g/4$ open stub in order to suppress the second harmonics. Due to insertion of BSF at input and output terminal, the size of the filter was increased in the conventional filter, however, in the proposed structure, the position of inverter that connects the stubs can be integrated between those stubs, thereby decreasing the size. So, it can be fabricated in the size of $18.7{\times}16.9mm^2$ which is smaller size than conventional one. The measured results of the proposed filters have center frequency of a 5.8 GHz with bandwidth of 95 %, insertion loss of 0.6 dB, return loss of 14 dB. The simulation results are consistent with measurement results. The filter is designed far X-band satellite communication and ITS applications.

A Study on Depth Data Extraction for Object Based on Camera Calibration of Known Patterns (기지 패턴의 카메라 Calibration에 기반한 물체의 깊이 데이터 추출에 관한 연구)

  • 조현우;서경호;김태효
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2001.06a
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    • pp.173-176
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    • 2001
  • In this thesis, a new measurement system is implemented for depth data extraction based on the camera calibration of the known pattern. The relation between 3D world coordinate and 2D image coordinate is analyzed. A new camera calibration algorithm is established from the analysis and then, the internal variables and external variables of the CCD camera are obtained. Suppose that the measurement plane is horizontal plane, from the 2D plane equation and coordinate transformation equation the approximation values corresponding minimum values using Newton-Rabbson method is obtained and they are stored into the look-up table for real time processing . A slit laser light is projected onto the object, and a 2D image obtained on the x-z plane in the measurement system. A 3D shape image can be obtained as the 2D (x-z)images are continuously acquired, during the object is moving to the y direction. The 3D shape images are displayed on computer monitor by use of OpenGL software. In a measuremental result, we found that the resolution of pixels have $\pm$ 1% of error in depth data. It seems that the error components are due to the vibration of mechanic and optical system. We expect that the measurement system need some of mechanic stability and precision optical system in order to improve the system.

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Design of Magnetic Systems for SNUT-79 Tokamak (SNUT-79 토카막의 자장 계통 설계)

  • Cheol Hee Nam;Sang Hee Hong;Kie Hyung Chung;Sang Ryul In
    • Nuclear Engineering and Technology
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    • v.16 no.2
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    • pp.89-96
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    • 1984
  • A toroidal-field (TF) coil with a pure tension D-shape curve is designed for the confinement of high-temperature plasmas in the SNUT-79, which is a tokamak being built at Seoul National University. A toroidal assembly of 16 D-shape TF coils is designed to produce the magnetic field of up to 3T, of which ripples appear to be below 4% of the average toroidal field in the plasma region. Exact positions and currents in six equilibrium coils distributed symmetrically in the z=0 plane are found by the solution of a set of linear equations which is transformed from a Fredholm integral equation of the first kind. The decay indices resulted from equilibrium field indicate that the stability condition for vertical and horizontal displacements is satisfied.

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Quasi Phase-Matched Second Harmonic-Wave Generation based on Nonlinear-Optic Effect Utilizing Ti:PPLN Optical Waveguides (Ti:PPLN 광도파로를 이용한 비선형광학 기반의 의사 위상정합 2차 조화파 발생)

  • Jung, Hong-Sik;Jung, Young-Sik
    • Korean Journal of Optics and Photonics
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    • v.19 no.6
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    • pp.408-415
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    • 2008
  • The characteristics of a ferroelectric-domain inverted grating fabricated by applying a high-voltage pulse at room temperature in Ti-diffused channel waveguides in z-cut $LiNbO_3$ (Ti:PPLN) were examined for channel waveguide quasi phase-matched secondharmonic generation devices. The fabrication conditions of uniform periodic domain-inversion were examined. Ti:PPLN with period ${\Lambda}=16.6{\mu}m$ for SHG were fabricated and the performances were measured. A normalized SHG efficiency as high as 473 (%/W) was obtained with 49 mm interaction length.

NURBS Post-Processing of Linear Tool Path (미소직선 공구경로의 NURBS 변환)

  • Kim, Su-Jin;Choi, In-Hugh;Yang, Min-Yang
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.7
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    • pp.1227-1233
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    • 2003
  • NURBS (Non Uniform Rational B-Spline) is widely used in CAD system and NC data for high speed machining. Conventional CAM system changes NURBS surface to tessellated meshes or Z-map model, and produces linear tool path. The linear tool path is not good fur precise machining and high speed machining. In this paper, an algorithm to change linear tool path to NURBS one was studied and the machining result of NURBS tool path was compared with that of linear tool path. The N-post including both a post-processing and a virtual machining software was developed. The N-Post transforms linear tool path to NURBS tool path and quickly shades a machined product on OpenGL view, while comparing a machined surface with a original CAD one. A virtulal machined model of original tool path and post-processed tool path was compared to original CAD model. The machining error and machining time of post-processed NURBS tool path were investigated.

A Study on Information Retrieval Systems Integration Using Common Object Request Broker Architecture (CORBA기능을 이용한 정보검색시스템 통합에 관한 연구)

  • 최한석;김상미;남태우;손덕주
    • Journal of the Korean Society for information Management
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    • v.13 no.2
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    • pp.223-242
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    • 1996
  • This study proposes an integration model of information retrieval systems using a standard distributed object computing technology in digital library environments. In the proposed integration model called DDIRIORB, the middleware broker based on CORBA is designed for the transparent access to the distributed information repositories and the consistent view of the information retrieval by applying 239.50 protocol. The DDIRIORB is an adaptable open architecture that allows for the following benefits : bibliographic and abstract information retrieval simultaneously, interoperability between application servers and clients, consistent view of search results, complexity reduction of integration interfaces, and easy to use.

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A Study on the non -linearity of wave washer spring (웨이브 와셔 스프링의 비선형성에 관한 연구)

  • 이수종;왕지석
    • Journal of Advanced Marine Engineering and Technology
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    • v.21 no.3
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    • pp.246-255
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    • 1997
  • The wave washer springs are expected to behave non-linearly between forces and displace¬ments due to contractions of the height and due to expansions in radial direction. To find out the non -linearity of wave washer springs, the three dimensional plate analysis theory using the finite element method is adopted in this paper. The wave washer springs are considered to be three dimensional plate structures rather than frame structures, because their thickness is normally much smaller than their width. The displacements of nodal points due to small increment of force are calculated by the finite element method and the calculated nodal displacements are added to X - Y Z coordinates of nodal points. The new stiffness matrix of the system using the new coordinates of nodal points is adopted to calculate the another nodal displacements, that is, the step by step method is used in this paper. The relations between the increments of forces and displacements in each step are recorded and plotted in chart. The experimental results are compared with the calculated chart and it is shown that there are good coincidences between measured values and calculated ones.

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NURBS Post-processing of Linear Tool Path (미소직선 공구경로의 NURBS 변환)

  • Kim, Su-Jin;Choi, In-Hugh;Yang, Min-Yang
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1111-1117
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    • 2003
  • NURBS (Non Uniform Rational B-Spline) is widely used in CAD system and NC data for high speed machining. Conventional CAM system changes NURBS surface to tessellated meshes or Z-map model, and produces linear tool path. The linear tool path is not good for precise machining and high speed machining. In this paper, an algorithm to change linear tool path to NURBS one was studied, and the machining result of NURBS tool path was compared with that of linear tool path. The N-post, post-processing and virtual machining software was developed. The N-Post post-processes linear tool path to NURBS tool path and quickly shades machined product on OpenGL view and compares a machined product with original CAD surface. A virtual machined model of original tool path and post-processed tool path was compared to original CAD model. The machining error of post-processed NURBS tool path was reduced to 43%. The original tool path and NURBS tool path was used to machine general model using same machine tool and machining condition. The machining time of post-processed NURBS tool path was reduced up to 38%.

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