• 한국통신학회논문지
• /
• 제34권10B호
• /
• pp.1124-1132
• /
• 2009

본 논문은 집적영상의 요소영상을 초해상도 영상복원에 이용하여 집적영상의 해상도를 향상시키는 방법을 제안한다. 집적영상에서 전체 요소영상의 인접한 단일 요소영상들 사이에는 대상물체의 동일한 부분의 상을 포함하는 공통부분이 존재한다. 이러한 공통부분들을 초해상도 영상복원의 저해상도 영상으로 이용하게 되면 CCD(Charge Coupled Device) 등의 영상취득 장치의 제한된 해상도로 인한 집적영상의 낮은 해상도 문제를 보완 할 수 있게 된다. 전체 요소영상과 제안된 방법을 이용하여 해상도를 향상시킨 전체 요소영상을 비교하여 제안된 방법의 타당성을 증명하였다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
• /
• pp.471-472
• /
• 2007

The scalp is skin tissue for skull-protection and roots for hair growth. Therefore continuous monitoring of scalp condition is essential for hair management. However, the equipments for existent are inconvenient to use because of focus tremor and external factors(Hair Gel, Wax, accessories and so on). Furthermore there is a problem to use an expensive optical devices like CCD (Charge Coupled Device) camera or lens of 200 - 1000 magnification. It causes a difficulty of using those equipment. We design the special electrode(length 5.65mm, diameter 0.8mm of needle shape) and the impedance system(1kHz, 78uA). Tn this paper, we can measure scalp impedance with our system. Moreover, we find the possibility of classifying scalp condition with measured impedance values. For the classification of scalp condition, we used ARAMO-TS as an imaging system. In conclusion, the problem of existent devices could be improved using these method. It also has a benefit of continuous monitoring of scalp condition.

• Journal of information and communication convergence engineering
• /
• 제11권3호
• /
• pp.185-189
• /
• 2013

A digital hologram generated by a computer calculation (computer-generated hologram or capture using charge-coupled device [CCD] camera) is one of the most expensive types of content, and its usage is expanding. Thus, it is highly necessary to protect the ownership of digital holograms. This paper presents an efficient visual security scheme for holographic image reconstruction with a low scrambling cost. Most recent studies on optical security concentrate their focus on security authentication using optical characteristics. However, in this paper, we propose an efficient scrambling method to protect a digital hologram. Therefore, we introduce in this paper several scrambling attempts in both the spatial domain and frequency domain on the basis of the results of analyzing the properties of the coefficients in each domain. To effectively hide the image information, 1/4, 1/256, and 1/16,384 of the original digital hologram needs to be scrambled for the spatial-domain scheme, Fresnel-domain scheme, and discrete cosine transform-domain scheme, respectively. The encryption schemes and the analyses in this paper can be expected to be useful in the research on encryption and other works on digital holograms.

• 조명전기설비학회논문지
• /
• 제29권2호
• /
• pp.8-18
• /
• 2015

This paper proposes a dimming method and a hybrid LED driving circuit suitable for the ultra high definition (UHD) broadcasting. There are major two problems during the dimming control for traditional LED broadcast lightings; one is a flicker that occurred when camera filming to these lightings, and the other is that linear control is impossible for LED luminous intensity under 10% due to LED electrical characteristics. The proposed dimming method and the driving circuit are designed to solve two problems simultaneously. For high level dimming control region from 10 to 100%, the analog control method was applied to the switching regulator constructed by MOSFET operated in the saturation region. For low level dimming control region under 10%, the fast PWM control method with the linear regulator constructed by MOSFET in the ohmic region was used. We verified experimentally that the dimming method is able to control the luminous intensity linearly from 1 to 100% and the flicker disappears on images taken by the charge coupled device (CCD) and the complementary metal oxide semiconductor (CMOS) cameras. Therefore, the proposed method is suitable for the UHD broadcasting.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
• /
• pp.1406-1408
• /
• 2003

KOMPSAT-1 (KOrea Multi-Purpose SATellite ? 1) EOC (Electro Optic Camera) raw images are radiometrically corrected on ground based on the characteristics of EOC. They consist of each CCD (Charge?Coupled Device) pixel’s calibration slope which was measured on ground, electrical gains which are applied to amplify for increasing output pixel counts. Currently, radio-metrically corrected EOC images with calibration slope have still shown defective features by residual stripes. So, it should be compensated by adjusting the calibration slope. In this paper, the adjustment of current calibration slope for de-striping EOC images is addressed and test results are shown.

• Journal of the Optical Society of Korea
• /
• 제17권1호
• /
• pp.50-56
• /
• 2013

Optical-fiber electronic speckle pattern interferometry (ESPI) is a non-contact, non-destructive examination technique with the advantages of rapid measurement, high accuracy, and full-field measurement. The optical-fiber ESPI system used in this study was compact and portable with the advantages of easy set-up and signal acquisition. By suitably configuring the optical-fiber ESPI system, producing an image signal in a charge-coupled device camera, and periodically modulating beam phases, we obtained phase information from the speckle pattern using a four-step phase shifting algorithm. Moreover, we compared the actual defect size with that of interference fringes which appeared on a screen after calculating the pixel value according to the distance between the object and the CCD camera. Conventional methods of measuring defects are time-consuming and resource-intensive because the estimated values are relative. However, our simple method could quantitatively estimate the defect length by carrying out numerical analysis for obtaining values on the X-axis in a line profile. The results showed reliable values for average error rates and a decrease in the error rate with increasing defect length or pressure.

• 한국방사성폐기물학회:학술대회논문집
• /
• 한국방사성폐기물학회 2004년도 학술논문집
• /
• pp.137-146
• /
• 2004

방사성폐기물 유리화 공전 중 용융로 내에서 유리시료를 직접분석 하기 위한 레이저유도 플라즈마분광법(LIBS: Laser Induced Breakdown Spectroscopy)을 개발 중이다. LIBS 시스템을 구성하기 위하여 분광기, 검출기, 레이저 등의 장비들을 구축하였다. 분광기는 CCD(charge coupled device)가 보정되어 내장되어있는 ESA 3000을 레이저는 Q-switched Nd-YAG인 Brilliant로 구매하여 분석시스템을 구축하였다. 구축된 분석시스템 분야별 성능들을 확인하였으며 최적화 연구를 수행하였다. 첫 번째 단계로 Fe가 함유된 시료에 레이저를 주사하였을 때 발광스펙트럼을 측정하였으며 검출기의 지연시간을 변화시켰을 때의 발광스펙트럼의 특성과 이를 이용한 여기온도를 Einstein-Boltzmann 식을 이용하여 계산하였다. 시료에 532nm Nd-YAG 레이저를 주사하고 검출기의 지연시간을 500, 1000, 1500, 2000ns로 변화시켰을 때의 분광선의 intensity 및 여기온도 변화를 분석하였다. 그 결과 검출시간이 1500㎱ 일 때 여기온도는 7820k로 가장 최적의 상태를 확인하였다. 향후 이 시스템은 유리화 실증시설에 적용되어 용융로 외부로의 유리시료 이송 없이 현장에서 유리성분들의 정량분석을 수행할 예정이다.

• 한국지리정보학회지
• /
• 제11권3호
• /
• pp.68-79
• /
• 2008

한국건설기술연구원(KICT)에서는 도로의 안전성 분석을 위해서 도로의 각종 정보를 이동하는 차량을 이용하여 신속하게 취득하고, 이를 토대로 도로의 결함구간을 분석할 수 있는 도로 안전성 조사 분석 차량(RoSSAV, Road Safety Survey and Analysis Vehicle)을 개발하였다. 본 연구를 통해 도로의 안전성에 의심이 되는 지역에 대해서 3차원 도로 모델링을 통한 도로 선형 결함 알고리즘을 개발하였으며, 이를 위해서는 신속하고 정확한 데이터가 수집되어야 한다. 차량에 회전식 레이저 스캐너, GPS(Global Positioning System), INS(Inertial Navigation System), CCD(Charge-Coupled Device) 카메라 그리고 DMI(Distance Measuring Instrument) 등 여러 센서를 장착하여 데이터를 취득하였다. 마지막으로 이들 데이터를 통합하여 3차원 도로 기하(도로 중심선, 도로 경계선), 도로 시설물과 사면을 추출하였다.

• 한국측량학회지
• /
• 제36권2호
• /
• pp.75-84
• /
• 2018

본 연구의 목적은 MEMS 기반의 INS를 적용한 저가형 MMS를 개발하고, 개발된 MMS를 이용하여 x, y의 평면 거리오차가 0.546m인 정확도를 확보하여 도로시설물의 판독에 활용하고자 함에 있다. MMS 기술은 해외 유수의 측량장비제작 업체를 중심으로 지리정보 구축을 위한 새로운 측량기술로 활발하게 사용되고 있지만 국내에서는 아직 관련 연구가 초기단계에 있다. 또한, MMS 장비개발은 몇몇 연구원 및 업체에서 시도를 하였으나 안정화가 이루어지지 않은 시작품 단계에 불과하다. 이러한 MMS 기술은 빠른 시간 내에 지형 지물 데이터를 취득할 수 있어 정밀지도 제작과 도로시설물 데이터 취득에 활용되고 있다. 따라서 본 연구에서는 MMS 제작에 사용하는 각종 센서(LiDAR, CCD camera, GPS/INS, DMI 등)를 동기화하여 MEMS 기반의 INS를 탑재한 저가형 MMS를 개발하고자 한다.

• Imaging Science in Dentistry
• /
• 제48권2호
• /
• pp.87-96
• /
• 2018

Purpose: The present study aimed to evaluate which of the following imaging methods best assessed misfit at the tooth-restoration interface: (1) bitewing radiographs, both conventional and digital, performed using a photostimulable phosphor plate (PSP) and a charge-coupled device (CCD) system; (2) panoramic radiographs, both conventional and digital; and (3) cone-beam computed tomography (CBCT). Materials and Methods: Forty healthy human molars with class I cavities were selected and divided into 4 groups according to the restoration that was applied: composite resin, composite resin with liner material to simulate misfit, dental amalgam, and dental amalgam with liner material to simulate misfit. Radiography and tomography were performed using the various imaging methods, and the resulting images were analyzed by 2 calibrated radiologists. The true presence or absence of misfit corresponding to an area of radiolucency in regions subjacent to the esthetic and metal restorations was validated with microscopy. The data were analyzed using a receiver operating characteristic (ROC) curve, and the scores were compared using the Cohen kappa coefficient. Results: For bitewing images, the digital systems (CCD and PSP) showed a higher area under the ROC curve (AUROC) for the evaluation of resin restorations, while the conventional images exhibited a larger AUROC for the evaluation of amalgam restorations. Conventional and digital panoramic radiographs did not yield good results for the evaluation of resin and amalgam restorations (P<.05). CBCT images exhibited good results for resin restorations(P>.05), but showed no discriminatory ability for amalgam restorations(P<.05). Conclusion: Bitewing radiographs (conventional or digital) should be the method of choice when assessing dental restoration misfit.