• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2012년도 하계학술대회
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• pp.401-404
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• 2012

기존 얼굴 인식 알고리즘은 단일 특징 기반의 전역적 방식이었다. 정확도를 향상시키기 위해 복수의 특징점을 이용하는 방법들이 제안되었으나 이는 알고리즘의 복잡도가 증가하고, 계산 속도가 느린 단점이 있다. 본 논문에서는 대표적인 특징점 추출 알고리즘인 SURF (Speeded Up Robust Features)를 이용한 얼굴 인식 방법을 제안한다. SURF 를 통해 기술어를 추출하고, Gabor 특징과 LBP 특징을 이용해 해당 특징점에서 기술어를 추출함으로써 기존 알고리즘보다 경량화할 수 있고, 수행시간을 줄일 수 있다. 잘 알려진 ORL 데이터베이스에서의 실험에서 제안한 방법이 정합시간을 포함한 수행 시간에서 약 16%의 감소를 보였고, 정확도 또한 약 34% 향상되었다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2011년도 추계학술대회
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• pp.19-22
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• 2011

본 논문에서는 대표적인 특징점 추출 알고리즘인 SURF (Speeded Up Robust Features)와 얼굴인식에서 널리 쓰이는 Gabor 기술어를 이용한 얼굴 인식 방법을 소개한다. SURF 기반 영상인식 방법은 특징점을 찾고 해당 특징점에서 기술어를 추출한 후, 정합을 수행한다. 본 논문에서는 SURF 를 통해 추출한 특징점에서 Gabor 웨이블릿 변환을 사용해 기술어를 추출하는 얼굴인식 방법을 제안한다. 잘 알려진 ORL 데이터베이스에서의 실험에서 제안한 방법이 기존 SURF 기반의 얼굴 인식 방법에 비해 더 높은 얼굴 인식 성능을 보여줄 뿐 아니라 정합시간을 포함한 처리 속도면에서도 더 우수한 성능을 보였다. 이러한 실험 결과를 통하여 제안하는 방법이 SURF 보다 얼굴 인식에 적합함을 확인할 수 있었다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2005년도 춘계학술발표대회 개요집
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• pp.229-231
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• 2005

Friction surfacing of STS304 consumable rod on S45C substrate was investigated by microstructural observation and mechanical tests. STS304 layer formed a strongly-bonded thick layer under a wide range of surfacing conditions. The hardness distribution showed the peak value in the boundry layer, while the highest coating efficiency obtained in the condition of 1000rpm-2.5mm/sec-2.5mm/sec. As the consumable rotation rate and the traveling rate increased, the coating efficiency tended to decrease. On the other hand, as the feeding rate increased, the coating efficiency appeared to be increased.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
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• pp.249-253
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• 2004

Wavelet transform (WT) has attracted most engineers and scientists because of its excellent properties. The coherence of practical approach and a theoretical basis not only solves currently important problems, but also gives the potential of formulating and solving completely new problems. It has been show that multi-resolution analysis of Wavelet transforms is good solution in speech analysis and threshold of wavelet coefficients has near optimal noise reduction property for many classes of signals. This paper proposed applications of wavelet in speech processing: pitch detection, voice-unvoice (V -UV) decision, denoising with the detailed algorithms and results.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.667-668
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• 2006

Radio Frequency Identification (RFID) is an automatic identification method, relying on storing and remotely retrieving data using devices called RFID tags or transponders. RFID systems is coming into increasing use in industry and logistics. This paper discuses implementation of multi-protocol RFID reader SoC. The SoC contains multi-protocol RFID RFID reader, CPU, UART, memory.

• Carbon letters
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• 제23권
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• pp.48-54
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• 2017

This research considers the effect of added mesophase pitch (MP) as an additive during the pitch synthesis reaction of pyrolyzed fuel oil (PFO). Two effects are generated by adding MP. One is an enhancement of thermal stability due to the high thermal property of the additive; the other is that the volatile compounds that were removed by vaporization of PFO during the thermal reaction can participate in the pitch synthesis reaction ($PFO{\rightarrow}pitch$) more efficiently. The effect differs according to the amount of the additive. When the amount of the additive is less than 7 wt%, the first effect is dominant, whereas the second effect is dominant when the additive amount exceeds 10 wt%.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1659-1661
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• 2003

Recently, diagnostic techniques have been investigated to defect a partial discharge in high voltage electrical equipment. We have studied the characteristics of the acoustic partial discharge originating from the electrical defects in cubicle GIS(C-GIS). An acoustic emission(AE) sensor is used on the enclosure to detect partial discharge source because the sensor is sensitive to stress waves in its frequency range that may not be from a partial discharge source. AE signal is analyzed with phase-magnitude-frequency number(${\Phi}$-V-n) and pulse per second(PPS). Experience result has shown that the omitted acoustic signal has phase dependency and phase shift characteristic according to increase with applied voltage. These result will be helpful to the pattern recognition of the acoustic partial discharge in a C-GIS.

• 비파괴검사학회지
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• 제12권3호
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• pp.33-39
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• 1992

This paper presents a summary of the immersion ultrasonic test to analyze the quality of diffusion bonding parts. The most important property of diffusion bonding parts is bonding strength, and that can be obtained by shear test. By comparing among data obtained by ultrasonic test(C-Scan) and those by shear test (bonding strength), these data are shown to be in good relation. Therefore ultrasonic C-Scan test result can be used successfully in quantitative quality control for diffusion bonded parts.

• Composites Research
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• 제37권4호
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• pp.330-336
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• 2024

Silicon carbide (SiC) fibers exhibit excellent heat and chemical resistance at high temperatures. In this study, polycarbosilane melt spinning, oxidation curing, and pyrolysis were performed to fabricate amorphous SiC fibers, and their resistance heating characteristics were evaluated. A stick-type amorphous silicon carbide fiber heating element was manufactured, and the resistance was measured using the two-point probe method. The structural, electrical, and heating characteristics were evaluated at different pyrolysis temperatures. The fiber produced at 1300℃ displayed the highest conductivity and the maximum heating compared to the fibers produced at 1200℃ and 1400℃. This may be attributed to difference in the structures of the fibers, particularly the SiC and graphitic carbon structures.

• IMMUNE NETWORK
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• 제5권4호
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• pp.221-231
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• 2005

Background: Immune regulatory dendritic cells (DCs) play an important role in maintaining self-tolerance. Recent evidences demonstrate that DCs expressing indoleamine 2,3-dioxygenase (IDO), which is involved in tryptophan catabolism, play an important role in immunoregulation and tolerance and induce T cell apoptosis. This study was devised to examine the role of IDO in the oral tolerance induction in collagen-induced arthritis (CIA) mouse model. Methods: Beginning 2 weeks before immunization, CII was fed six times to DBA/1 mice and the effect on arthritis was assessed. In tolerized mice, $CD11c^+$ DCs were isolated and stimulated with CII, IFN-${\gamma}$, and LPS with or without IDO inhibitor, 1-methyl-DL-tryptophan (1-MT) and IDO expression by $CD11c^+$ DCs was analyzed using FACS and RT-PCR. The expression of IDO, MHC II, CD80, and CD86 by $CD11c^+$ DCs were examined using confocal microscopy. Regulatory effect of $CD11c^+$ DCs on Ag-specific T cell proliferative response to CII was examined by mixed lymphocyte reaction (MLR) with or without 1-MT. Results: The proportion of IDO-expressing $CD11c^+$ DCs was slightly higher in tolerized mice than in CIA mice and significantly increased after stimulation with CII, IFN-${\gamma}$, and LPS in an IDO-dependent manner. On confocal microscopic examination, the expression of IDO was higher and those of MHC II and CD86 were lower in CD11c + DCs from tolerized mice compared to those from CIA mice. On MLR, $CD11c^+$ DCs from tolerized mice inhibited T cell proliferative response to CII in an IDO-dependent manner. Conclusion: Enhanced IDO expression by $CD11c^+$ DCs from tolerized mice may contribute to the regulation of proliferative response of CII-reactive T cells and could be involved in the induction of oral tolerance to CII.