• 천문학회보
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• 제38권2호
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• pp.82.2-82.2
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• 2013

The NISS (Near-infrared Imaging Spectrometer for Star formation history) onboard NEXTSat-1 is being developed by KASI. The NISS will perform the imaging low-resolution spectroscopic observation in the near-infrared range for nearby galaxies, low background regions, starforming regions and so on. The off-axis reflecting telescope with a wide field of view (2 deg. ${\times}$ 2 deg.) will be operated in the wavelength range from 0.95 to $3.8{\mu}m$. In order to reduce thermal noise, a telescope and a HgCdTe infrared sensor will be cooled down to 200K and 80K, respectively. To evade a stray light outside a field of view and use limited space efficiently, the NISS adopted the off-axis reflective optical system. The primary and secondary mirrors, optomechanical part and mechanical structure were designed to use the same material. It will lessen the degradation of optical performance due to a thermal variation. The purpose of NISS is the observation of cosmic near-infrared background in the wide wavelength range as well as the detection of near-infrared spectral lines in nearby galaxies, cluster of galaxies and star forming regions. It will give us less biased information on the star formation history. In addition, we will demonstrate the space technologies related to the development of the Korea's leading near-infrared instrument for the future large infrared telescope, SPICA.

• 한국방사선학회논문지
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• 제3권4호
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• pp.35-38
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• 2009

최근 의료영상분야에서 형광체와 광도전체 물질을 이용한 디지털 평판형 X선 영상검출기가 폭넓게 이용되고 있다. 본 연구는 CsI:Na 형광체층과 광민감도가 우수한 비정질 셀레늄(a-Se)층의 이중 접합구조로 구성된 변환구조 설계를 위한 몬테카를로 시뮬레이션과 X선에 대한 광학적 및 전기적 반응특성을 조사하였다. 먼저 CsI:Na의 발광스펙트럼과 a-Se의 광흡수 스펙트럼을 측정하여 X선에 의한 신호 변환특성을 분석하였다. 또한, 인가전기장의 함수에 따른 X선 민감도을 측정하여 상용화된 a-Se($500{\mu}m$)의 직접변환 검출기와 비교 평가하였다. 측정결과로부터, $10V/{\mu}m$에서 CsI:Na($180{\mu}m$)/a-Se($30{\mu}m$) 변환센서의 X선 민감도는 $7.31nC/mR-cm^2$ 이고, a-Se($500{\mu}m$) 검출기는 $3.95nC/mR-cm^2$로 약 2배 정도 높은 값을 보였다.

• 대한방사선기술학회지:방사선기술과학
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• 제32권1호
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• pp.53-60
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• 2009

인체의 $40{\sim}50%$인 연부조직에 X선을 조사하면 연부조직의 두께에 따라 투과선량이 감소하며 영상에도 질적 저하를 가져온다. 본 연구는 복부 촬영시 위장내 내용물에 따라 X선 감약 및 화질에 차이가 나타날 수 있다는 가정 하에 실제 위의 조직과 비슷한 조직등가물질 phantom을 제작하여 실제 위장내 내용물에 따른 X선의 감약 변화와 DR (Digital Ridiography)의 ROI수치를 비교해보았다. 단백질 두께가 증가할수록 X-선 감약에 의한 투과선량이 감소되었으며(p < 0.001), Film과 DR 영상에서의 ROI Mean값의 변화도 감소하였다(p <0.001). Film과 DR 영상에서의 ROI Mean값에 대한 비교는 Film이 DR 영상에 비해 단백질 두께에 따른 농도의 변화 값이 크게 나타났다(p < 0.001). 이와 같은 결과를 종합해 볼 때 DR system 촬영 보다는 필름을 사용하는 단순촬영에서 금식(NPO ; nothing by mouth)의 필요성이 더 중요함을 알 수 있다.

• 치과방사선
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• 제28권2호
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• pp.471-489
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• 1998

For the successful endodontic treatment, root canal should be cleaned thoroughly by accurate mechanical and chemical canal preparation and sealed completely with canal filling material without damaging the periapical tissues. The accuracy of the root canal length measurement is a prerequisite for the success of the endodontic treatment, and the root canal length is often determined by the standard periapical radiographs and digital tactile sense. In this study, the accuracy and the clinical usefulness of Digora/sup (R)/, an intraoral digital imaging processor and the conventional standard radiographs were compared by measuring the length from the top of the file to the root apex. 30 single rooted premolars were invested in a uniformly sized blocks and No.25 K-file was inserted into and fixed in each canal. Each block was placed in equal distance and position to satisfy the principle of the bisecting angle and paralleling techniques and Digora/sup (R)/ system's image and standard periapical radiographs were taken. Each radiograph was examined by 3 different observers by measuring the length from top of the file to the root apex and each data was compared and analyzed. The results were as follows; 1. In the bisecting angle technique, the average difference between the Digora/sup (R)/ system and standard periapical radiograph was 0.002 mm and the standard deviation was 0.341 mm which showed no statistically significant difference between the two systems(p>0.05). Also, in the paralleling technique, the average difference between these two system was 0.007 mm and the standard deviation was 0.323 mm which showed no statistically significant difference between the two systems(p>0.05). 2. In Digora/sup (R)/ system, the average difference between the bisecting angle and paralleling technique was -0.336 mm and the standard deviation was 0.472 mm which showed a statistically significant difference between the two techniques(p<0.05). Also, in the standard periapical radiographs, the average difference between the bisecting angle and paralleling technique was 0.328 mm and the standard deviation was 0.517 mm which showed a statistically significant difference between these two techniques(p<0.05). 3. In Digora/sup (R)/ system and the standard periapical radiographs. there was a statistically significant difference between the measurement using the bisecting angle technique and the actual length(p<0.05), But there was no statistically significant difference between the measurement using the paralleling technique and the actuallength(p>0.05). In conclusion. the determination of the root canal length by using the Digora/sup (R)/ system can give us as good an image as the standard periapical radiograph and using the paralleling technique instead of the bisecting angle technique can give a measurement closer to the actual canal length. thereby contributing to a successful result. Also. considering the advantages of the digital imaging processor such as decreasing the amount of exposure to the patient. immediate use of the image. magnification of image size. control of the contrast and brightness and the ability of storing the image can give us good reason to replace the standard periapical radiographs.

• 공업화학
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• 제28권3호
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• pp.263-271
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• 2017

최근에, 질량분석기술의 폴리머 분석에의 응용은 MALDI-TOF MS 개발 이후 급속도로 발전하였다. 이 리뷰 논문은 현재까지 연구된 MALDI-TOF MS의 폴리머 특성분석에의 응용에 관한 최신 논문을 정리하였다. MALDI-TOF MS는 바이오 폴리머와, 합성 폴리머의 평균분자량 분석, 폴리머의 시퀀스 분석을 통한 구조의 해석, 모노머의 조성분석에까지 이용되고 있다. 엔드그룹의 특성과 농도를 분석하는 연구도 많이 진행되었고, 복잡한 폴리머의 분자량의 분석에는 SEC와 MALDI-TOF MS를 연결한 분석법을 추천한다. MALDI에 tandem MS를 결합한 분석기술이나, 이온 모빌리티를 응용한 질량분석기, TOF-SIMS, MALDI-TOF-Imaging 기술도 급격히 발전하고 있으며, 이의 폴리머 특성분석에의 응용은 별도의 분리기술이 필요 없어 앞으로 더 많이 이용될 것으로 생각된다. 분자량, 시퀀스, 그리고 모노머의 조성을 정확하게 계산해주는 소프트웨어와 고분자량(> 100 kDa)의 분석을 가능하게 해주는 기술이 개발된다면, 폴리머를 연구하는 과학자들에게 MALDI-TOF MS의 이용은 문제점을 해결하고, 목적하는 폴리머를 합성하는 데 중요한 수단이 될 것이다.

• 대한디지털의료영상학회논문지
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• 제9권2호
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• pp.17-21
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• 2007

The purpose to recognize change of average pixel value of acquisition image by control panel's density and right set up method of speed (sensitivity) and exposure dose(mAs) change that dose in purpose digital flatpanel-detector. X -ray generator DHF-158H2(Hitachi, Japan). Detector CXDI 4OG(Canon, Japan), 12 : 1 grid and exposure ray 135 kVp, 250 mA, 10 ms. focus-detector distance 180 cm and used AEC mode. DICOM reflex analysis program used image J that is digital reflex analysis program that offer in United States America National Health Center(National Institutes of Health : NlH) phantom used chest phantom(Anthromorphic : Flukebrome.medicaI USA). An experiment chest phantom that consist by formation equivalence material use because density value( -3${\sim}$+3) in X-ray control panel and seep that is speed step(slow, medium, fast) each control experimentalize. image analysis reflex neted through an experiment using image j each image compare. These was change in dose according to slow, medium, fast and density's change in an experiment result. According to detector sensitivity and density condition set, dose was relationship dissimilarity 500% from 200%. The dose came highest when is density +3 to slow. and dose more increases gray scale's extent could know that rise. Could know whether how equipment set is important through this experiment. cause of disease which change by digital radiography system forward is thought to increase more, it is considered that suitable education by this and continuous interest about equipment need absolutely.

• Journal of Radiation Protection and Research
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• 제35권1호
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• pp.43-48
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• 2010

방사선의 선질은 X선관의 target에 따라 결정된다. 유방검사의 경우 Molybdenum target을 사용하는데 22~28 kV 범위에서 평균 17.9~19.5 keV의 Mo 특성에너지를 얻어 유방의 high contrast 영상을 얻을 수 있다. 따라서 본 연구에서는 최근 대부분의 유방 검사장치에 이용되는 Mo/Mo 조합 유방장치의 미세병변 탐지능력을 측정하기 위하여 ALVIM TRM 팬텀을 이용하여 그 기초적인 실험으로 획득한 영상을 ROC(receiver operating characteristic) curve를 통해 분석하였다. 유방의 평균 피사체 두께가 40 mm로 가정하고 kV와 mAs, 그리고 두께변화에 따른 질환 검출능력을 실험한 결과, kV 변화에서는 Speck과 Fiber의 병소 검출능력이 거의 차이를 보이지 않은 것으로 나타났으며, mAs와 피사체두께 변화에서는 많은 차이를 보이는 것으로 나타났다. 즉, 유방의 피사체 평균두께인 약 40 mm에서는 관전압 변화가 병소의 검출능력에 많은 영향을 끼치지 않으므로 평균 두께의 피사체에서는 관전압을 높여서는 안된다.

• Investigative Magnetic Resonance Imaging
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• 제2권1호
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• pp.58-66
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• 1998

목적: 본 논문은 마코브 랜덤필드(Markov Random Field)와 깁스 랜덤필드(Gibbs Random Field) 및 라인모델(LIne Model)에 기반한 3차원 자기공명영상의 분류 방법을 소개하고자 하였다. 대상 및 방법 : 통계적으로 이질적 성분들로 구성된 영상을 대상으로한 깁스분류 결과는 영상내의 국소적으로 정적인 영역들을 이웃화소 시스템 내에서 정의되는 상호작용 인자(inetraction parameter)의 메커니즘에 의해 분리하\ulcorner로서 개선시킬 수 있다. 이를 위하여 영상에서 라인모델의 생성을 고려할 수 있으며, 본 논문에서는 영상의 미분방법에 근거한 다중신호영상을 위한 라인모델을 구축하였다. 라인모델은 서로 상이한 통게적 특성을 갖는 영역사이에 존재하는 관측할 수 없는 라인필드의 존재 유무를 확률 값으로 제공한다. 영상으로부터 획득한 라이모델은 Gibbs 분류기의 에너지함수 값을 결정하는 상호작용 인자 값을 결정하는데 사용된다. 결과 : 3차원 자기공명영상의 분류를 위한 MRS-Gibbs 분류기는 영상분류의 도메인이 일반적인 이차원 영상의 $E^{2}$ 공간에서 $E^{3}$ 공간으로 확장되었다. 개발된 깁스분류기를 이용한 자기공명여상의 분류결과 기존의 context free 분류방법에 의한 결과에 비하여 특히 동일성질을 갖고 있는 영역 및 경계부분 등의 분류결과가 우수함을 알 수 있었다. 결론 : 본 논문에서는 다중 신호, 3차원 자기공명영상을 위한 라인모델을 구축하고 그로부터 MRF-Gibbs분류기의 에너지함수를 결정하기 위한 상호작용 인자를 유도하였다.

• International Journal of Railway
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• 제1권4호
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• pp.149-156
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• 2008

During maintenance or construction works in or at the tracks of railways, high risks for passengers and railway staff, especially for the workers on the construction site exist. The high risks result out of the movement of rail vehicles, like trains or construction vehicles, which must be faced by using any available technical and operational technologies for securing them against the environment. Therefore, it is necessary to evaluate the level of protection continuously and to identify new and innovative methods and technologies for the protection of the gang (construction worker, machines and material). Especially on construction sites at line sections with two or more parallel tracks but also with single tracks, there are still a lot of incidents and accidents mostly with seriously injured persons or fatalities. These were mainly gang members that breach the railway-loading gage. By using proper warning or protection systems, the avoidance of such accidents must be achieved. The latest developments. in gang protection systems concern on the one hand fixed barriers in the middle between the construction site and the operated track and on the other hand construction vehicles equipped with automatic warning systems. The disadvantage of such protection methods is that the gang can be warned against an approaching train but a monitoring of the gang members cannot be performed. Only one part of a potential dangerous situation will be detected. If the gang members will overhear the acoustic warning signal of the security staff and the workers will not leave the danger zone in the track, the driver of the approaching train had no chance to react to the dangerous situation. An accident is often inevitable. While the detection of acoustic warning signals by the gang members working on a construction site is very difficult, the acoustical planning of an automatic warning system has to be designed for an acoustic short range level of one meter besides the construction vehicle. The decision about the use of today's technical warning system (fixed systems, automatic warning systems, etc.) must be geared to the technical feasibility and the level of safety which is needed. Criteria for decision guidance to block a track should be developed by danger estimation and economical variables. To realize the actual jurisdiction and to minimize the hazards of railway operations by the use of construction vehicles near the tracks further developments are needed. This means, that the warning systems have to be enhanced to systems for protection, which monitor the realization of the warning signal as a precondition for giving a movement authority to a train. This method can protect against accidents caused by predictable wrongdoing. The actual state of the art technique of using a collective warning combined with additional security staff is no longer acceptable. Therefore, the Institute of Transportation System of the German Aerospace Center in Braunschweig (Germany) will develop a gang warning and protection system based upon imaging methods, with optical sensors such as video in visible and invisible ranges, radar, laser, and other. The advantage of such a system based on the possibility to monitor both the gang itself and the railway-loading gauge either of the parallel track or of the same track still in use. By monitoring both situations, the system will be able to generate a warning message for the approaching train, that there are obstacles in the track, so that the train can be stopped to prevent an accident. And also the gang workers will be warned, while they breach their area.

• 방사선산업학회지
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• 제11권1호
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• pp.1-6
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• 2017

Reported some level of bacteria in areas that are well made contact in Radiology imaging room evaluate the importance of cleanliness in the hospital management of equipment to check for the presence of pathogenic bacteria. Gwang-ju and Jeol-la city and medium-sized hospitals in the material with a cotton swab and rub evenly Radiology selection cassette, a handle, Apron of the imaging apparatus having the most contact with patients from July 2016 to August 2016 as a target in place and special studios 6, and saline solution will placed in a test tube containing. The swab sample was diluted 1,000 times, you can see the bacteria and the intestinal bacterial selective medium Trypticase Soy Agar (TSA), Muller-Hinton Agar (MHA), Eosin-Methylene Blue (EMB), ENDO(BD, NJ, USA) then incubated smear to. In the incubator (incubator, SANYO, Japan) was observed after incubation of bacteria and counting the total number of bacteria also Colonies (colony) suspected intestinal bacteria were isolated and cultured on KIA medium (BD, NJ, USA). As a result, it was found that this came Gram positive Coccus A hospital handle the F hospital, from the C Gram positive Coccus cassette and handle the F hospital. The striking yellow coloring Staphylococcus aureus 110 agar (STA 110) in the medium sample, but it is suspected staphylococcal Coccus to the final identification in the laboratory is not a single specimen of the two samples from Gram positive Coccus biochemical identification Identification Kit is an API could not, it was thought to be non-Staphylococcus aureus was cultured on blood agar suggesting that (BAP) blood of dance. Dynamic tests were conducted biochemical API kit of the two samples were identified from Gram positive Coccus bacteria Escherichia coli (E. coli) is F hospital cassette was confirmed Eenterobacter cloaca in A hospital possession. Did not aggregate O-26, O-111, O-157 and the serum test was conducted in the laboratory from the E. coli F cassette hospital.