• Title/Summary/Keyword: Z-Transform

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3D Reconstruction Method for 3D Engraving Systems (3D 조각가공 시스템을 위한 3 차원 복원 방법)

  • Lee, Won-Seck;Chung, Sung-Chong
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1204-1209
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    • 2008
  • Design is important in the IT, digital appliance, and auto industries. Aesthetic and art images are being applied for better design satisfaction of the products. Various artistic image patterns are used to satisfy demand of design, but it takes much lead-time and effort to implement them for making dies and molds. In this paper, a hybrid reverse engineering method generating accurate 3D engraving models from 2D art images is proposed through image processing, 3D reconstruction, and NURBS interpolation methods. In order to generate the 3D model from the 2D artistic image, cloud points with z-depth are extracted according to intensity values of the image. An adaptive median filter and harmonic filter are used to obtain the intensity values accurately. NURBS surfaces are generated through the interpolation of the cloud points. Performance of the developed system is to be confirmed through the realization of Mona Lisa and Golden Gate Bridge.

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The crystal and molecular structure of $\gamma$-hydroxy-.$\beta$-amino butyric acid

  • Kim, Yang-Bae
    • Archives of Pharmacal Research
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    • v.8 no.1
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    • pp.1-6
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    • 1985
  • The crystal structure or $\gamma$-hydroxy-$\betha$-aminobutyric acid was determined by MULTAN system with X-ray intensity data on a diffractometer and refined by the least-squares method to an R-value 0.034 for 711 reflections. The crystals were orthorhombic, space group $P2_{1}2_{1}2_{1}$, Z = 4, with a = 10.220, b = 8.257 and c = 6.556$\AA$. The molecule takes the zwitterionic form and skeletal conformation is trans-transform. The molecules are held together by intra-and intermolecular NH-O and OH--O hydrogen bonds.

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The Correcting Algorithm on Geometric Distortion of Polar Format Algorithm (PFA의 기하 왜곡 보정 기법)

  • Lee, Hankil;Kim, Donghwan;Son, Inhye
    • Journal of the Korea Institute of Military Science and Technology
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    • v.21 no.1
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    • pp.17-24
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    • 2018
  • Polar fomat algorithm (PFA) was derived from medical imaging theory, known as back projection, to process synthetic aperture radar(SAR) data. The difference between the operating condition of SAR and back projection assumption makes two distortions. First, the focusing performance of PFA is degraded in proportion to distances from the scene center. Second, the geometric accuracy in SAR images is distorted. Several methods were introduced to mitigate the distortions, but some disadvantages, such as the geometric discontinuity, are arisen when sub-images are combined. This paper proposes the novel method to compensate the geometric distortion with chirp Z-transform (CZT). This method corrects precisely the geometric errors without any problems, because a whole image can be processed all at once.

Optimized Automatic Noise Level Calculations for Broadband FT-ICR Mass Spectra of Petroleum Give More Reliable and Faster Peak Picking Results

  • Hur, Manhoi;Oh, Han-Bin;Kim, Sung-Hwan
    • Bulletin of the Korean Chemical Society
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    • v.30 no.11
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    • pp.2665-2668
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    • 2009
  • A new algorithm for determining noise level is proposed for more reliability in interpreting spectral data for complex Fourier transform ion cyclotron resonance (FTICR) mass spectra of petroleum. In the new algorithm, a moving window with a fixed number of data points was adopted, instead of a fixed m/z width. In the analysis of petroleum, it was found that a moving window of 50,000 or more data points was optimal. This optimized automated peak picking performed well even with frequency-dependant noise in the mass spectrum. Additionally, this fast, automated peak picking algorithm was suitable for the analysis of a large set of samples.

Cavity-backed Two-arm Spiral Antenna with a Ring-shaped Absorber for Partial Discharge Diagnosis

  • Kim, Han-Byul;Hwang, Keum-Cheol;Kim, Hyeong-Seok
    • Journal of Electrical Engineering and Technology
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    • v.8 no.4
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    • pp.856-862
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    • 2013
  • A cavity-backed two-arm spiral antenna for partial discharge diagnosis is presented. The proposed antenna consists of a two-arm Archimedean spiral, a tapered microstrip balun as spiral antenna feed, and a ring-shaped absorber-loaded cavity. The Archimedean spiral antenna is designed for the operating frequency band of 0.3 GHz to 1.5 GHz and fed by the tapered microstrip balun. The cavity is utilized to transform the bidirectional beam into a unidirectional beam, thereby enhancing gain. The ring-shaped absorber is stacked in the cavity to reduce the reflected waves from the cavity wall. The proposed antenna is designed and simulated using CST Microwave Studio. A prototype of the proposed antenna is likewise fabricated and tested. The measured radiation patterns are directional to the positive z-axis, and the measured peak gain is 8.13 dBi at a frequency of 1.1 GHz.

Improvement in Control Performance of a Servo System Compensating Bandwidth Variations at Low Speed

  • Ji, Young-Eun;Park, Je-Wook;Hwang, Seon-Hwan;Baek, Kwang-Ryul;Kim, Jang-Mok
    • Journal of Power Electronics
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    • v.10 no.4
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    • pp.382-387
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    • 2010
  • This paper presents a novel design method for determining the PID gains of a speed controller for a servo system compensating variations in bandwidth at a low speed. The variations in bandwidth of a speed controller are measured at a low speed and the relationship between the bandwidth and the damping ratio are verified by determining the location of the closed loop pole. The proposed algorithm uses the z-transform of a plant and speed controller and applies the time-varying sampling method for determining the PID gains of the speed controller at low speed. The magnitude and the phase condition are considered for finding a suitable control gain. The usefulness and effectiveness of the proposed method is demonstrated through experimental results such as low speed control and robust disturbance responses.

Radix-2 16-points FFT accelerator implementation using FPGA (FPGA 를 사용한 radix-2 16-points FFT 알고리즘 가속기 구현)

  • Gyu Sup Lee;Seong-Min Cho;Seung-Hyun Seo
    • Proceedings of the Korea Information Processing Society Conference
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    • 2023.05a
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    • pp.23-25
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    • 2023
  • 본 논문에서는 FPGA 를 활용하여 radix-2 Fast Fourier Transform(FFT) 알고리즘을 빠르고 효율적으로 구현하는 연구에 대해 기술한다. 본 논문에서 zybo z7-20 FPGA 를 사용하여 Processing System(PS)에서만 동작하는 구현과 Programmable Logic(PL)에서 동작하며 파이프라인과 병렬처리를 사용한 FFT 구현 결과를 비교한다. 또한 유사한 논문과의 결과 비교를 통해 본 구현 방법의 연산 시간 및 리소스 사용의 효율성을 분석한다.

Transient dynamic analysis of sandwich beam subjected to thermal and pulse load

  • Layla M. Nassir;Mouayed H.Z. Al-Toki;Nadhim M. Faleh;Hussein Alwan Khudhair;Mamoon A.A. Al-Jaafari;Raad M. Fenjan
    • Steel and Composite Structures
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    • v.51 no.1
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    • pp.1-8
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    • 2024
  • Transient dynamic behavior of a sandwich beam under thermal and impulsive loads has been researched in the context of higher-order beam theory. The impulse load of blast type has been enforced on the top exponent of the sandwich beam while it is in a thermal environment. The core of the sandwich beam is cellular with auxetic rectangular pattern, whereas the layers have been built with the incorporation of graphene oxide powder (GOP) and are micromechanically introduced through Halpin-Tsai formulization. Governing equations for the sandwich beam have been solved through inverse Laplace transform style for obtaining the dynamical deflections. The connection of beam deflections on temperature variability, GOP quantity, pulse load situation and core relative density has been surveyed in detail.

Analysis of antigenic domain of GST fused major surface protein (p30) fragments of Toxoplasma gondii (융합단백질로 발현된 톡소포자충의 주요막단백질(p30) 절편의 항원성)

  • 남호우;임경심
    • Parasites, Hosts and Diseases
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    • v.34 no.2
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    • pp.135-142
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    • 1996
  • Antigenic domain of jai or surface protein (p30) of Toxoplosmc Sondii was analyzed after polymerase chain reaction (PCR) of its gene fragments. Hydrophilic or hydrophobic moiety of amino acid sequences were expressed as glutathione S-transferase (G57) fusion proteins. Fragments of p30 gene were as follows: 737, total p30 open reading frame (ORF) ; S28, total ORF excluding N-terminal signal sequence and C-terminal hydrophobic sequence; Al9, N-terminal 2/3 parts of A28; A19, N-terminal 2/3 of S28; P9, C-terminal 2/3 part of S28; Z9. middle 1/3 of S28; and 29, C-terminal 1/3 of S28. respectively. Primer of each fragment was synthesized to include clamp sequence of EcoR I restriction site. PCR amplified DNA was inserted info GST (26 kDa) expression vector, PGEX-47-1 to transform into Escheri,hia coei (.JM105 strain). G57 fusion proteins were expressed with IPTG induction as 63. 54, 45, 45, 35, 36. and 35 kDa proteins measured by SDS-PAGE. Each fusion protein was confirmed with G57 detection kit. Western blot analysis with the serum of a toxoplasmosis patient revealed antigenicity in proteins expressed by T37. S28, and Al9 but not those by Pl8. X9, Y10, and Z9. Antigenicity of p30 seems to be located either in N-terminal 115 part in the presence of middle 1/3 part or in the oligopeptides between margins of the first and second 1/3 parts.

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Analysis of IR-UWB Tapered Slot Antenna Radiation Pattern using the Group delay and Fidelity (군 지연 및 충실도를 이용한 IR-UWB용 테이퍼 슬롯 안테나 방사패턴 분석)

  • Kim, Keun-Yong;Ko, Yong-Mok;Park, Kyoung-Jin;Kang, Een-Kyun;Lee, Dae-Woo;Park, Jong-Hyun;Ra, Keuk-Whan
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.8
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    • pp.308-315
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    • 2013
  • In this paper, Tapered slot antenna of IR-UWB was Designed and fabricated using HFSS and we suggest the beam width of the broadband antenna using group-delay and fidelity. For this purpose, acquired data from the Network Analyzer was analyzed in the time domain by using the chirp-Z transform and Simulation was conducted and confirmed with the CST microwave studio. Analysis of the antenna radiation pattern is the antenna separation at intervals of 0.5 metres and then transmit antenna is fixed and the receiving antenna 360 degree intervals of 10 degree each, The results of the analysis are as follows, and analyzer of the fidelity of the antenna's performance. An analysis of more than 90 percent of the cases is less than ${\pm}40$ degrees in good fidelity, more than 90% less than ${\pm}40$ degrees and lowe fidelity. In conclusion, Analysis of Beam width of wideband antenna with more precise is possible through using these radiation pattern using fidelity.