• 제목/요약/키워드: EL Imaging

검색결과 42건 처리시간 0.028초

GaAs 웨이퍼의 대역단 영상에 대한 정량적 해석 (Quantitative Analysis on Near Band Edge Images in GaAs Wafer)

  • 강성준;나철훈
    • 한국정보통신학회논문지
    • /
    • 제21권5호
    • /
    • pp.861-868
    • /
    • 2017
  • 도핑 되지 않은 반 절연 LEC GaAs내의 EL2와 얕은 준위 분포를 영상화하기 위해 대역단 적외선 영상 기법을 활용했다. 대역단 적외선 투사 매핑에 근거한 본 기법은 분석 속도가 빠르고 비파괴적인 방법이다. EL2 흡수 영상이 콘트라스트 반전되는 대역단 부근에 대한 정량적인 해석은 아직 보고되지 않고 있다. 본 논문은 대역단 부근에서 영상의 특정 부분(cell, wall)에 대한 포토퀀칭 메커니즘의 스펙트럼-, 공간- 및 온도- 종속성을 논하고 있다. 결함 부분별(EL2w, EL2b)로 포토퀀칭 개시점이 다른 것은 불순물 종류의 차이로 인한 서로 다른 전기적 작용에 기인한 것으로 해석할 수 있다. 전위(dislocation) 밀도가 높은 곳에서는 EL2b 밀도는 약간 적은 반면 EL2w 밀도는 보다 많다는 것을 정량적 해석으로부터 확인 했다.

반절연 갈륨비소의 적외선 영상에 의한 웨이퍼성장조건 및 온도종속 퀀칭율 증명 (Evidence of Material-dependent and Temperature- dependent Quenching Rates by Infrared Imaging in S.I. GaAs)

  • 강성준
    • 대한전자공학회논문지SD
    • /
    • 제40권7호
    • /
    • pp.469-473
    • /
    • 2003
  • 적외선 영상기법을 이용해 반절연 GaAs 기판 내의 EL2 영상에 대한 Photoquenching의 영향을 성장원상태(as-grown)의 샘플과 열처리 샘플을 중심으로 분석하였다. 본 논문에서 Quenching 메커니즘은 샘플에 의존적이고 또한 Quenching율은 샘플의 성장조건과 Quenching 온도에 따라 다르다는 것을 영상적으로 정확히 증명하고 있는데 이 기존의 연구내용과는 다소 상충된 새로운 내용이다.

The role of cone-beam computed tomography in the radiographic evaluation of obstructive sleep apnea: A review article

  • Marco Isaac;Dina Mohamed ElBeshlawy;Ahmed ElSobki;Dina Fahim Ahmed;Sarah Mohammed Kenawy
    • Imaging Science in Dentistry
    • /
    • 제53권4호
    • /
    • pp.283-289
    • /
    • 2023
  • The apnea-hypopnea index is widely regarded as a measure of the severity of obstructive sleep apnea (OSA), a condition characterized by recurrent episodes of apnea or hypopnea during sleep that induce airway collapse. OSA is a catastrophic problem due to the wide range of health issues it can cause, including cardiovascular disease and memory loss. This review was conducted to clarify the roles of various imaging modalities, particularly cone-beam computed tomography (CBCT), in the diagnosis of and preoperative planning for OSA. Unfortunately, 2-dimensional imaging techniques yield insufficient data for a comprehensive diagnosis, given the complex anatomy of the airway. Three-dimensional (3D) imaging is favored as it more accurately represents the patient's airway structure. Although computed tomography and magnetic resonance imaging can depict the actual 3D airway architecture, their use is limited by factors such as high radiation dose and noise associated with the scans. This review indicates that CBCT is a low-radiation imaging technique that can be used to incidentally identify patients with OSA, thereby facilitating early referral and ultimately enhancing the accuracy of surgical outcome predictions.

EL-CID를 이용한 발전기 고정자 철심의 건전성 평가 (Healthy Assessment of Generator Stator Cores using EL-CID (ELectromagnetic Core Imperfection Detector))

  • 김병래;김희동
    • 전기학회논문지
    • /
    • 제58권2호
    • /
    • pp.356-362
    • /
    • 2009
  • The ELectromagnetic Core Imperfection Detector (EL-CID) test was performed on a small generator in the laboratory and a gas turbine generator in the field to assess the fault condition of generator stator core. Artificial defects with six different sizes were introduced in the small generator. The scan results on six defects show a very large increase in the magnitude of fault current compared to that obtained with a healthy core. After the stator core heats up, a thermal imaging camera was used to detect hot spot on the inner surface of the core for comparison. Several faults were found during inspection of the gas turbine generator with the EL-CID. It has been shown that the existence of a fault can be determined by monitoring the magnitude of fault current.

360-degree Viewable Cylindrical Integral Imaging System Using Electroluminescent Films

  • Jung, Jae-Hyun;Park, Gil-Bae;Kim, Yun-Hee;Lee, Byoung-Ho
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
    • /
    • pp.1254-1257
    • /
    • 2009
  • A 360-degree viewable three-dimensional display based on integral imaging is proposed. The cylindrically arranged point light source array which is generated by electroluminescent (EL) pinhole film reconstructs 360-degree viewable virtual 3D image at the center of the cylinder. In this paper, the principle of operation and experimental results are presented.

  • PDF

360-degree Viewable Cylindrical Integral Imaging System Using Electroluminescent Films

  • Jung, Jae-Hyun;Park, Gil-Bae;Kim, Yun-Hee;Lee, Byoung-Ho
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
    • /
    • pp.1330-1333
    • /
    • 2009
  • A 360-degree viewable three-dimensional display based on integral imaging is proposed. The cylindrically arranged point light source array which is generated by electroluminescent (EL) pinhole film reconstructs 360-degree viewable virtual 3D image at the center of the cylinder. In this paper, the principle of operation and experimental results are presented.

  • PDF

A New Robust Blind Crypto-Watermarking Method for Medical Images Security

  • Mohamed Boussif;Oussema Boufares;Aloui Noureddine;Adnene Cherif
    • International Journal of Computer Science & Network Security
    • /
    • 제24권3호
    • /
    • pp.93-100
    • /
    • 2024
  • In this paper, we propose a novel robust blind crypto-watermarking method for medical images security based on hiding of DICOM patient information (patient name, age...) in the medical imaging. The DICOM patient information is encrypted using the AES standard algorithm before its insertion in the medical image. The cover image is divided in blocks of 8x8, in each we insert 1-bit of the encrypted watermark in the hybrid transform domain by applying respectively the 2D-LWT (Lifting wavelet transforms), the 2D-DCT (discrete cosine transforms), and the SVD (singular value decomposition). The scheme is tested by applying various attacks such as noise, filtering and compression. Experimental results show that no visible difference between the watermarked images and the original images and the test against attack shows the good robustness of the proposed algorithm.

가강수량의 변화패턴과 기후인자와의 상관성 분석 (Relationship between temporal variability of TPW and climate variables)

  • 이다래;한경수;권채영;이경상;서민지;최성원;성노훈;이창석
    • 대한원격탐사학회지
    • /
    • 제32권3호
    • /
    • pp.331-337
    • /
    • 2016
  • 수증기는 지구 장파 복사에너지의 주요 흡수인자이다. 따라서 수증기량의 변화를 모니터링하고 변화의 원인을 세밀하게 조사하는 것은 필수적이다. 본 연구에서는 위성관측에 의해 얻어지는 Total Precipitable Water (TPW)자료를 사용하여 가강수량의 변화패턴을 모니터링 하고자 한다. 또한 기후인자들 중 수증기를 통해 생성되어 수증기의 변화패턴을 분석하는데 있어 중요한 역할을 하는 강수량과 다른 기후인자들에 비해 비교적 주기적으로 나타나는 엘니뇨를 통해 가강수량의 변화패턴과 기후인자와의 상관성분석을 실시하고자 한다. 본 연구에서는 TERRA/AQUA 위성의 Moderate-Resolution Imaging Spectroadiometer (MODIS) 센서를 통해 관측된 TPW의 장기적인 변화와 한반도 중남부지방의 강수량변화를 정량적으로 분석하고, 이들의 관계를 엘니뇨와 함께 비교하였다. 이를 통해 엘니뇨의 발생이 한반도 중남부지방의 강수량과 TPW의 변화에 영향을 주고 있는 지에 대해 조사하고자 한다. 먼저, 시계열 분석을 통해 TPW와 중남부지방 강수량의 변화를 정량적으로 산출하고 anomaly분석을 통해 이들의 변화를 세밀하게 분석한 결과 서로 반대의 양상을 띠는 부분이 발견되어 엘니뇨의 anomaly분석결과와 비교하였다. 그 결과 대부분 같은 양상을 띠고 있던 TPW와 강수량이 엘니뇨가 발생한 후 서로 반대의 양상을 띠는 것을 확인하였다.

Radiosynthesis and Biodistribution of an 125I-labeled Resveratrol Derivative

  • Kim, Sung-Kew;Lee, Woong-San;Han, Sang-Jin;Kim, Eun-Jung;El-Gamal, Mohammed I.;Kim, Byoung-Soo;Choi, Tae-Hyun;Choi, Chang-Woon;Ham, In-Hye;Oh, Chang-Hyun;Choi, Ho-Young;Cho, Jung-Hyuck
    • Bulletin of the Korean Chemical Society
    • /
    • 제33권2호
    • /
    • pp.489-491
    • /
    • 2012
  • An $^{125}I$-labeled resveratrol derivative 1 was synthesized. It was purified by reverse phase HPLC. Radiochemical purity of the product was more than 98%, and the yield was 35% (decay-corrected). Its biodistribution in tumorbearing mice was studied. The results showed that the highest radioactivity was located in intestine and stomach. The biodistribution profile suggests that compound 1 can be effectively used as a promising imaging probe for intestine and stomach.

The radioactivity levels and beta dose rate assessment from dental ceramic materials in Egypt

  • Mohamed Hasabelnaby;Mohamed Y. Hanfi;Hany El-Gamal;Ahmed H. El Gindy;Mayeen Uddin Khandakerf;Ghada Salaheldin
    • Nuclear Engineering and Technology
    • /
    • 제56권9호
    • /
    • pp.3898-3903
    • /
    • 2024
  • There is a lack of available data on the radioactivity levels of these materials, despite the potential risks they may pose to patients, dental technicians, and dentists. A total of forty samples were collected from different dental markets in Egypt. Using an NaI(Tl) detector, the gamma-ray spectrometer measured the activity levels of uranium-238, radium-226, thorium-232, and potassium-40. The findings revealed that the mean concentration of 238U (below the minimum detectable activity, MDA), 226Ra (135 ± 5 and 132 ± 5 Bq/kg), 232Th (187 ± 4 and 243 ± 8 Bq/kg), and 40K (1560 ± 52 and 2501 ± 89 Bq/kg) in feldspar and zirconia (ZrO2) dental ceramic samples, respectively, were all within the limits established by the International Organization for Standardization (ISO) and the European Commission (EC). The use of feldspar and zirconia dental ceramics to restore all teeth would result in an estimated maximum beta dose of 1.5 mGy/year to the oral tissue. The results suggest that there is no cause for concern regarding any additional beta dose to the oral cavity from the use of feldspar and zirconia dental ceramics.