• 한국컴퓨터정보학회논문지
• /
• 제14권12호
• /
• pp.97-107
• /
• 2009

TV뉴스는 매일 전 세계의 소식을 불특정 다수에게 전달함으로써 시청자의 정보 해석에 중요한 영향을 미친다. 방송환경의 급격한 변화로 HDTV로 불리는 고화질 시대에 앵커의 미세한 표정과 옷차림까지 들춰질 수 있는 시각적인 집중도가 있는 점을 감안할 때, 해상도에 더욱 신경을 써야하는 세심함이 요구된다. 따라서 HDTV에 더욱 중요한 조명 기술이 가지는 표현의 미는 강조의 여지가 없다. 보도방송에서도 이러한 변화추세에 따른 현상으로, TV 뉴스 제작 행태는 DLP(Digital Lighting Processing)나 LED(Light Emitting Diode)기법을 통해서, 기존 TV뉴스 제작 행태를 탈피하고자 하는 변화의 길을 모색해 왔다. 이와 같은 노력은 HDTV에 적합한 화질을 구현하는데 기여하였다. 요즈음 디지털영상에서는 조명 장치만을 사용하던 기존 아날로그 기반의 조명 환경이 IT기술의 발전과 더불어 디지털화된 조명 장비의 개발로 TV뉴스 제작행태에 활력을 불어 넣고 있다. 이러한 변화는 HDTV 스튜디오 구축과 세트 및 조명 시스템을 설비하기에 이르렀다 1990년대 이후, HDTV의 등장으로 필름 세트와 스크린에 영상을 투사하는 프로젝터와 최근 들어 그 활용도가 커진 PDP, LCD, DLP등이 있으며, 뉴스 외에 다른 프로그램에서 자주사용되는 LED 배경화면이 그 예이다. 본 논문은 이러한 방송환경 변화에 따라 텔레비전 영상 구성 요소가 TV뉴스 시청자의 화면 집중도에 미치는 영향을 탐색하기 위해서 KBS9시 뉴스의 조명 기법을 분석하였다. 분석 결과를 토대로 앵커가 정보를 전달하는데 있어서 앵커 이미지 형성의 범주를 조명 기법으로 제안한다.

• 대한치과기공학회지
• /
• 제42권4호
• /
• pp.355-361
• /
• 2020

Purpose: In this study, we added two kinds of photoinitiators (CQ and TPO) to prepare two kinds of denture base resins (Bis-GMA series and UDMA series) for three-dimensional (3D) printing to compare and analyze their mechanical and biological properties and to find the optimal composition. Methods: Control specimens were made using the mold made of polyvinyl siloxane of the same size. Light curing was performed twice for 20 seconds on both the upper and lower surfaces with LED (light emitting diode) light-curing unit (n=10). Experimental 3D printing dental resins were prepared, to which two photoinitiators were added. Digital light processing type 3D printer (EMBER, Autodesk, CA, USA) was used for 3D printing. The specimen size was 64 mm×10 mm×3.3 mm according to ISO 20795-1. The final specimens were tested for flexural strength and flexural modulus, and MTT test was performed. Furthermore, one-way analysis of variance was performed, and the post-test was analyzed by Duncan's test at α=0.05. Results: The flexural strength of both Bis-GMA+CQ (97.12±6.47 MPa) and UDMA+TPO (97.40±3.75 MPa) was significantly higher (p<0.05) in the experimental group. The flexural modulus in the experimental group of UDMA+TPO (2.56±0.06 GPa) was the highest (p<0.05). MTT test revealed that all the experimental groups showed more than 70% cell activity. Conclusion: The composition of UDMA+TPO showed excellent results in flexural strength, flexural modulus, and biocompatibility.

• 한국정밀공학회지
• /
• 제4권2호
• /
• pp.36-46
• /
• 1987

An optical technique using laser for non-contact measurement of surface roughness and form accuracy of ground surfaces is presented. It is found that, when a ground surface is illuminated by a beam of laser light, the roughness height and slope distribution has significant influence on the pattern of reflection and it maintains an unique Gaussian distribution relationship with the surface roughness. The principle idea of the optical measurement system is therefore monitor the radiation, and then calibrate it in process against surface roughness by means of necessary digital data processing. On the other hand, measuring the form accuracy of a ground surface is accomplished by using a triangular method, which is based on observing the movement of an image of a spot of light projected onto the surface. The image is focused, through a series of lenses for magnification, on a photodetector array lf line configur- ation. Then the relative movement of image and consequently the form accuracy of the surface can be obtained through appropriate calibration procedures. Experimental test showed that the optical roughness measurement technique suggested in this work is very efficient for most industrial applications being capable of monitoring the roughness heights ranging 0.1 to 0.6 .$\mu$m CLA values. And form accuracy can be measured in process with a resolution of 10 .$\mu$m.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제12권7호
• /
• pp.3239-3267
• /
• 2018

Image and video dehazing is a popular topic in the field of computer vision and digital image processing. A fast, optimized dehazing algorithm was recently proposed that enhances contrast and reduces flickering artifacts in a dehazed video sequence by minimizing a cost function that makes transmission values spatially and temporally coherent. However, its fixed-size block partitioning leads to block effects. The temporal cost function also suffers from the temporal non-coherence of newly appearing objects in a scene. Further, the weak edges in a hazy image are not addressed. Hence, a video dehazing algorithm based on well designed spectral clustering is proposed. To avoid block artifacts, the spectral clustering is customized to segment static scenes to ensure the same target has the same transmission value. Assuming that edge images dehazed with optimized transmission values have richer detail than before restoration, an edge intensity function is added to the spatial consistency cost model. Atmospheric light is estimated using a modified quadtree search. Different temporal transmission models are established for newly appearing objects, static backgrounds, and moving objects. The experimental results demonstrate that the new method provides higher dehazing quality and lower time complexity than the previous technique.

• Nuclear Engineering and Technology
• /
• 제52권12호
• /
• pp.2910-2917
• /
• 2020

Digital light processing three-dimensional (3D) printing technique is a powerful tool to rapidly manufacture plastic scintillators of almost any shape or geometric features. In our previous study, the main properties of light output and transmission were analyzed. However, a more detailed study of the other properties is required to develop 3D printed plastic scintillators with expectable and reproducible properties. The 3D printed plastic scintillator displayed an average decay time constants of 15.6 ns, intrinsic energy resolution of 13.2%, and intrinsic detection efficiency of 6.81% for 477 keV Compton electrons from the ¹³⁷Cs γ-ray source. The 3D printed plastic scintillator showed a similar decay time and intrinsic detection efficiency as that of a commercial plastic scintillator BC408. Furthermore, the presented estimates for the properties showed good agreement with the analyzed data.

• 대한치과기공학회지
• /
• 제46권1호
• /
• pp.8-14
• /
• 2024

Purpose: This study compares the deformation of traditional resin dentures to resin dentures printed with digital light processing (DLP). Methods: Eleven edentulous research models were developed. Ten of them were made with traditional resin dentures. The remaining one was prepared for scanning and 3D (three-dimensional) printing. Ten traditional resin dentures were made, with the remaining artificial teeth created using 3D software and a DLP printer. Traditional resin dentures, 3D printed resin denture artificial teeth, and a denture base with artificial teeth were all cleaned simultaneously in an ultrasonic cleaner for 3 minutes. Three groups were assigned four artificial tooth measurement points, which were then measured with digital calipers. The measured data was analyzed using descriptive statistics. The significance test was conducted using a nonparametric test Kruskal-Wallis test due to the small number of specimens (α=0.05). Results: The traditional resin dentures had the lowest strain rate at -0.04%, while the group that manufactured only artificial teeth had the highest strain rate at -0.09%. However, no statistically significant difference was observed between the 3 groups (p>0.05). Conclusion: During ultraviolet-type ultrasonic cleaning, traditional resin dentures (TD group) and denture base with artificial teeth made of DLP (DD group) demonstrated stable durability, whereas the artificial teeth made of DLP (AD group) with only artificial teeth did not show a good deformation rate.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2002년도 춘계학술대회 논문집
• /
• pp.357-360
• /
• 2002

Nowadays, the improvement and development of Multi-media, information and communication technology are rapidly processed. And many products, for example, digital camera, digital camcorder, and PDA, are used for them. They need large data storage capacity and small size, light storage system. Due to that, many studies and researches in data storage system have been carried out. Especially, micro drive system was presented by IBM.(1) However, its system is expensive and uneasy to be portable. In ODD technologies, 1 inch drive system is not yet or in processing status.(2) If to be possible and to be come up, it is cheap than HDD system and easy to transfer information. In this paper, a miniaturized actuator(about linch) is designed and tested for ODD system. Specially, it is adapted for NFR(Near-field Recoding) system using SIL(Solid Immersion Lens). It is the dual-servo actuator which consists of a coarse actuator and fine actuator. Its actuating force generation method is VCM(Voice Ceil Motor). The fine actuator has 4-wire suspensions and bobbin wrapped by coil and includes focusing motion as well as tracking motion. The coarse actuator has an actuating coil and V-grooved guide mechanism. Also, the characteristics of the designed actuator is estimated by sine-swept mode and LDV(Laser Doppler Vibro-meter).

• 전자공학회논문지D
• /
• 제34D권11호
• /
• pp.90-100
• /
• 1997

In this paper, we propose a new optical thresold generator as a key-stream genrator for stream cipher systems. The random key-bit stream is generated by a digital generator that is composed of LFSRs and nonlinear ligics. Digital implementatin of a key-stream generator requires large memory to implement programmable tapping points. This memory problem may be overcome easily by using the proposed optical system which has the proberty of 2D parallel processing.To implement hte threshold generator optically, we use conventional twisted nematic type SLMs (LCDs). This proposed system is based on the shadow casting technique for the AND operation between taps and sregister stages. It is also based on the proposed PMRS method for modulo 2 addition. The proposed PMRS method uses the property of light's polarization on LCD and can be implemented optically using one LCD and some mirrors. One of the major advantages of the proosed system is that there is no limitation of the number of the progarmmable tapping points. Therefore, the proposed system can be applied for the 2D encryption system which processes large amounts of data such as 2D images. We verify the proposed system with some simulation.

• 디지털산업정보학회논문지
• /
• 제12권4호
• /
• pp.107-114
• /
• 2016

Recently, 3D related technology has become a hot topic for IT. 3D technologies such as 3DTV, Kinect and 3D printers are becoming more and more popular. According to the flow of the times, the goal of this study is that the general public is exposed to 3D technology easily. we have developed a web-based application program that enables 3D modeling of facial front and side photographs using a mobile phone. In order to realize 3D modeling, two photographs (front and side) are photographed with a mobile camera, and ASM (Active Shape Model) and skin binarization technique are used to extract facial height such as nose from facial and side photographs. Three-dimensional coordinates are generated using the face extracted from the front photograph and the face height obtained from the side photograph. Using the 3-D coordinates generated for the standard face model modeled with the standard face as a control point, the face becomes the face of the subject when the RBF (Radial Basis Function) interpolation method is used. Also, in order to cover the face with the modified face model, the control point found in the front photograph is mapped to the texture map coordinate to generate the texture image. Finally, the deformed face model is covered with a texture image, and the 3D modeled image is displayed to the user.

• 정보처리학회논문지:소프트웨어 및 데이터공학
• /
• 제4권12호
• /
• pp.561-570
• /
• 2015

IT 기술이 급격히 발전함에 따라서 디지털 멀티미디어 장치 및 소프트웨어를 이용한 콘텐츠가 범람하고 있다. 그러나 불법적 목적을 가지고 있는 사용자가 활용함에 따라 이를 이용한 범죄가 증가되고 있고 멀티미디어 포렌식을 통한 콘텐츠의 보호 및 불법 사용 차단의 필요성이 대두되고 있다. 본 논문에서는 센서 패턴 잡음을 이용하여 디지털 영상 획득 장치 판별을 위한 포렌식 기술에 대하여 제안한다. 먼저 광자 탐지기의 빛에 대한 민감도가 불완전해 생기는 센서 패턴 잡음을 검출하기 위한 기술에 대하여 제시한다. 그다음에 참조 영상들에 대하여 센서 패턴 잡음을 추정하고, 검사 영상에 대하여 센서 패턴 잡음을 추정한 후 두 잡음 사이의 유사성 계산을 통하여 디지털 영상을 획득한 장치에 대하여 판별하는 방법을 설명한다. 제안한 기술의 성능 분석을 위하여 DSLR 카메라, Compact 카메라, 스마트폰, 캠코더 등을 포함한 총 10대 장치에 대하여 개발한 알고리즘에 대한 정량적 성능의 분석을 수행하였고, 그 결과 99.6%의 판별 정확도를 달성하였다.