• 한국콘텐츠학회논문지
• /
• 제14권2호
• /
• pp.475-481
• /
• 2014

이 연구의 목적은 감마선 검출 시스템을 개발하여 평행구멍형 조준기와 바늘구멍 조준기를 이용하여, 각각 소동물용 감마영상 획득과 환경 방사선 검출 영상을 획득하는 것이다. 본 연구에서는 크기가 $50{\times}50mm$ 이며, 6 mm 두께의 CsI(Tl) 섬광체와 $50{\times}50mm$ 크기의 Hamamatsu H8500C 위치민감형 광전자증배관, 저항분배회로, 전치증폭기, 성형증폭기, NIM 모듈 및 아날로그 디지털 변환기로 구성된 감마카메라를 개발하였다. 또한. 바늘구멍 감마카메라와 전하결합소자 카메라를 결합하여 환경모니터링에 적용할 수 있는 장비를 개발하였다. 본 연구 결과는 평행 구멍형 조준기와 바늘구멍 조준기를 이용한 감마카메라를 각각 소동물용 감마영상 획득과 환경방사선 측정에 적용 할 수 있음을 보여주었다. 이 시스템은 소 동물전용 감마카메라와 환경방사선 측정 시스템으로 활용 될 수 있을 것이다.

• 한국컴퓨터정보학회논문지
• /
• 제17권12호
• /
• pp.41-47
• /
• 2012

모든 물체는 절대온도 0도 이상에서 복사에너지를 방출한다. 비냉각 열상시스템은 입사된 복사에너지를 검출하여 신호처리를 통해 영상으로 출력하는 장비이다. 최근에는 비냉각 열상장비를 활용하여 의료, 산업, 및 군수 등의 다양한 분야에 응용 되고 있으며, 다양한 응용분야에 대한 많은 연구가 진행되고 있다. 본 논문에서는 비냉각 열상시스템 검출기 내부에 열전소자가 없는 검출기를 보다 효과적으로 제어하여 영상의 화질을 향상시키고 이를 기반으로 온도 측정 정밀도를 극대화 할 수있는 효율적인 제어기법에 대해 설명한다. 제안하는 기법은 비냉각 열상시스템에 TEC-less 및 온도 검출 알고리듬을 적용하는 것이다. 실제 챔버를 활용하여 시험을 수행한 결과 알고리듬 적용 전 시스템보다 우수한 화질의 영상을 획득하고 온도 측정 정밀도가 $1^{\circ}C$이하로 향상됨을 확인할 수 있었다.

• 한국광학회지
• /
• 제32권5호
• /
• pp.215-219
• /
• 2021

최근 농작물의 상황을 실시간이면서도 비파괴적으로 측정하는 시스템이 스마트팜 등의 분야에서 필수적인 요소로 주목받고 있다. 본 연구에서는 초분광 영상 기술을 통해 많은 개체 수의 청경채 유묘 내의 안토시아닌 함량을 비파괴적으로 동시에 측정하였다. 많은 유묘의 동시 측정을 위해서, 기존의 초분광 영상 시스템의 실험 구성을 수정하였다. 품종당 24개씩 총 96개의 유묘를 측정하였고, 한번의 초분광 데이터 획득시 12개의 유묘가 동시에 분석 가능했으며, 총 3분이 소요된다. 본 논문에서 제안한 초분광 영상 기술은 파괴적 화학 분석 방법과 비교 가능한 분석 시스템을 제공하는 것으로 나타났다. 또한 많은 수의 식물을 동시에 측정함으로써, 초분광 영상 기술이 초고속 피노타이핑 시스템에 적용될 수 있다는 가능성을 확인하였다.

• Current Optics and Photonics
• /
• 제5권6호
• /
• pp.606-616
• /
• 2021

A photonic integrated interferometric imaging system possesses the characteristics of small-scale, low weight, low power consumption, and better image quality. It has potential application for replacing conventional large space telescopes. In this paper, the principle of photonic integrated interferometric imaging is investigated. A novel lenslet array arrangement and lenslet pairing approach are proposed, which are helpful in improving spatial frequency coverage. For the novel lenslet array arrangement, two short interference arms were evenly distributed between two adjacent long interference arms. Each lenslet in the array would be paired twice through the novel lenslet pairing approach. Moreover, the image reconstruction model for optical interferometric imaging based on compressed sensing was established. Image simulation results show that the peak signal to noise ratio (PSNR) of the reconstructed image based on compressive sensing is about 10 dB higher than that of the direct restored image. Meanwhile, the normalized mean square error (NMSE) of the direct restored image is approximately 0.38 higher than that of the reconstructed image. Structural similarity index measure (SSIM) of the reconstructed image based on compressed sensing is about 0.33 higher than that of the direct restored image. The increased spatial frequency coverage and image reconstruction approach jointly contribute to better image quality of the photonic integrated interferometric imaging system.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
• /
• pp.488-491
• /
• 2003

Biochip-based diagnostic technology is an effective, time- and money- saving way. But, biochip analyzer including CCD imaging system has a complete optical system. It is one of reasons that the cost of biochip analyzer is expensive with CCD imaging system. In this paper, We suggested the simple and effective optical system for biochip analyzer with CCD imaging system. It consists of two parts with the same structure but opposite direction. Each part consists of achromatic doublet and meniscus. Suggested optical system has less lenses than existing system and more efficiently.

• 치과방사선
• /
• 제29권1호
• /
• pp.149-159
• /
• 1999

Purpose: The purpose of this study was to evaluate cervical lymph node metastasis of oral squamous cell carcinoma patients by MRI film and neural network system. Materials and Methods: The oral squamous cell carcinoma patients(21 patients. 59 lymph nodes) who have visited SNU hospital and been taken by MRI. were included in this study. Neck dissection operations were done and all of the cervical lymph nodes were confirmed with biopsy. In MR images. each lymph node were evaluated by using 6 MR imaging criteria(size. roundness. heterogeneity. rim enhancement. central necrosis, grouping) respectively. Positive predictive value. negative predictive value. and accuracy of each MR imaging criteria were calculated. At neural network system. the layers of neural network system consisted of 10 input layer units. 10 hidden layer units and 1 output layer unit. 6 MR imaging criteria previously described and 4 MR imaging criteria (site I-node level II and submandibular area. site II-other node level. shape I-oval. shape II-bean) were included for input layer units. The training files were made of 39 lymph nodes(24 metastatic lymph nodes. 10 non-metastatic lymph nodes) and the testing files were made of other 20 lymph nodes(10 metastatic lymph nodes. 10 non-metastatic lymph nodes). The neural network system was trained with training files and the output level (metastatic index) of testing files were acquired. Diagnosis was decided according to 4 different standard metastatic index-68. 78. 88. 98 respectively and positive predictive values. negative predictive values and accuracy of each standard metastatic index were calculated. Results: In the diagnosis of using single MR imaging criteria. the rim enhancement criteria had highest positive predictive value (0.95) and the size criteria had highest negative predictive value (0.77). In the diagnosis of using single MR imaging criteria. the highest accurate criteria was heterogeneity (accuracy: 0.81) and the lowest one was central necrosis (accuracy: 0.59). In the diagnosis of using neural network systems. the highest accurate standard metastatic index was 78. and that time. the accuracy was 0.90. Neural network system was more accurate than any other single MR imaging criteria in evaluating cervical lymph node metastasis. Conclusion: Neural network system has been shown to be more useful than any other single MR imaging criteria. In future. Neural network system will be powerful aiding tool in evaluating cervical node metastasis.

• 비파괴검사학회지
• /
• 제35권6호
• /
• pp.389-397
• /
• 2015

Recently, wave propagation imaging based on laser scanning-generated elastic waves has been intensively used for nondestructive inspection. However, the proficiency of the conventional software based system reduces when the scan area is large since the processing time increases significantly due to unavoidable processor multitasking, where computing resources are shared with multiple processes. Hence, the field programmable gate array (FPGA) was introduced for a wave propagation imaging method in order to obtain extreme processing time reduction. An FPGA board was used for the design, implementing post-processing ultrasonic wave propagation imaging (UWPI). The results were compared with the conventional system and considerable improvement was observed, with at least 78% (scanning of $100{\times}100mm^2$ with 0.5 mm interval) to 87.5% (scanning of $200{\times}200mm^2$ with 0.5 mm interval) less processing time, strengthening the claim for the research. This new concept to implement FPGA technology into the UPI system will act as a break-through technology for full-scale automatic inspection.

• 센서학회지
• /
• 제21권3호
• /
• pp.217-222
• /
• 2012

Optical coherence tomography(OCT) is a noninvasive optical imaging tool for biomedical applications. OCT can provide depth resolved two/three dimensional morphological images on biological samples. In this paper, we integrated an OCT system that was composed of an SLED(Superluminescent Light Emitting Diode, ${\lambda}_0$=1305 nm bandwith= 141 nm), a reference arm adopting a rapid scanning optical delay line(RSOD) to get high speed imaging, and a sample arm that used a micro electro mechanical systems(MEMS) scanning mirror. The sample arm contained a compact probe for imaging dental structures. The performance of the system was evaluated by imaging in-vivo human teeth with dental calculus, and the results indicated distinct appearance of dental calculus from enamel, gum or decayed teeth. The developed probe and system could successfully confirm the presence of dental calculus with a very high spatial resolution($6{\mu}m$).

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
• /
• pp.388-391
• /
• 2003

The properties of these detectors can be controlled by electronics and exposure conditions. Flat-panel detectors for digital diagnostic imaging convert incident x-ray images to charge images. Flat panel detectors gain more interest real time medical x-ray imaging. Active area of flat panel detector is $14{\times}17$ inch. Detector is based on a $2560{\times}3072$ away of photoconductor and TFT pixels. X-ray conversion layer is deposited upper TFT array flat panel with a 500m by thermal deposition technology. Thickness uniformity of this layer is made of thickness control technology(5%) of thermal deposition system. Each $139m{\times}139m$ pixel is made of thin film transistor technology, a storage capacitor and charge collection electrode having geometrical fill factor of 86%. Using the separate driving system of two dimensional mosaic modules for large area, that is able to 4.2 second per frame. Imaging performance is suited for digital radiography imaging substitute by conventional radiography film system..

• Korean Journal of Radiology
• /
• 제21권10호
• /
• pp.1115-1125
• /
• 2020

Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a primary liver cancer (PLC) with both hepatocytic and cholangiocytic phenotypes. Recently, the World Health Organization (WHO) updated its histological classification system for cHCC-CCA. Compared to the previous WHO histological classification system, the new version no longer recognizes subtypes of cHCC-CCA with stem cell features. Furthermore, some of these cHCC-CCA subtypes with stem cell features have been recategorized as either hepatocellular carcinomas (HCCs) or intrahepatic cholangiocarcinomas (ICCs). Additionally, distinctive diagnostic terms for intermediate cell carcinomas and cholangiolocarcinomas (previous cholangiolocellular carcinoma subtype) are now recommended. It is important for radiologists to understand these changes because of its potential impact on the imaging-based diagnosis of HCC, particularly because cHCC-CCAs frequently manifest as HCC mimickers, ICC mimickers, or as indeterminate on imaging studies. Therefore, in this review, we introduce the 2019 WHO classification system for cHCC-CCA, illustrate important imaging features characteristic of its subtypes, discuss the impact on imaging-based diagnosis of HCC, and address other important considerations.