• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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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.

• Archives of Pharmacal Research
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• 제8권1호
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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.

• 한국군사과학기술학회지
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• 제21권1호
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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.

• Bulletin of the Korean Chemical Society
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• 제30권11호
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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.

• Journal of Electrical Engineering and Technology
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• 제8권4호
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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.

• Journal of Power Electronics
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• 제10권4호
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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.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2023년도 춘계학술발표대회
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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.

• Steel and Composite Structures
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• 제51권1호
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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.

• Parasites, Hosts and Diseases
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• 제34권2호
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• pp.135-142
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• 1996

톡소포자충(Toxoplosma gondii) 주요막단백질의 하나인 30 kDa 단백질(p30)의 항원부위를 결정하고자 p30의 아미노산 분석에 따른 친수성 부위 및 혐수성 부위에 맞게 유전자를 증폭하고 발현시켜 항원성을 검토하였다 p30의 절편으로는 p30 전체 p30의 N-말단 Signal Sequence와 C- 탈단의 혐수성 부위를 제거한 S28. S28의 N-말단 2/3부위인 Al9. S28의 C-말단 2/3부위인 Pl9. 528의 N-탈난 1/3부위인 X9 중앙 1/3부위인 Y10 및 C-말단 1/5부위인 Z9로 구성하였다. 각절편에 대한 primer에는 EcoR I의 clampsequence를 포함시켜 중합효소반응으로 증폭시켰으며 G57를 발현하는 pGEX-4T-1 vector에 삽입시킨 후 Eschericha coli(.JM105 strain)에 형질변형시키고 IgG로 각 절편이 GST와 융합단백질로 발현되도록 하였다 SDS-PAGE상에서 p30은 63 kDa. S28는 54 kDa Al9과 Pl9은 각각 45 kDa. X9은 35 kDa. Y10은 36 kDa 및 29은 35 kDa 단백질로 발현되었다. 각각의 단백질은 westemblot상에서 GSTdetectionkit와 잘 반응하여 융합단백질임을 확인하였다. 톡소포자충증 환자 혈청과 westem blot에서 p30. S28 및 Al9은 반응하여 항원성이 인정되었으나 Pl9 . X9, Y10 및 Z9는 반응하지 않았다 따라서. p30의 중간 1/3 부위의 존재하에 N-말단 1/3부위가 항원성을 나타내는 구조적 항원이거나. 첫 1/3부위와 중 간 1/3부위의 경계에 위치한 polypeptide가 항원성을 발현하는 것으로 추정되었다.

• 전자공학회논문지
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• 제50권8호
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• pp.308-315
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• 2013

본 논문에서는 IR-UWB를 위한 테이퍼 슬롯 안테나를 Ansoft인 HFFS을 사용하여 설계 및 제작 하였고 안테나의 군 지연 및 충실도를 사용하여 광대역 안테나의 빔 폭에 대해 연구를 제안하였다. 이를 위해 Network Analyzer에서 획득한 데이터를 Chirp Z-transform을 사용하여 시간영역에서의 분석을 하였고 시뮬레이션은 CST microwave studio를 이용하여 이를 확인 하였다. 안테나의 방사패턴의 분석은 두 안테나를 0.5 미터 간격으로 이격시킨 후 송신 안테나를 고정 후 수신 안테나를 $10^{\circ}$ 간격으로 $360^{\circ}$ 회전하여 각각의 충실도를 획득하여 안테나의 성능 분석하였다. 분석한 결과 ${\pm}40^{\circ}$ 미만일 경우 90%이상의 양호한 충실도를 얻었고 ${\pm}40^{\circ}$ 이상은 90%이하의 낮은 결과를 얻었다. 이러한 충실도를 이용한 방사패턴을 사용함으로 광대역 안테나의 빔 폭을 보다 정확한 분석을 할 수 있다.