• 대한방사선기술학회지:방사선기술과학
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• 제44권3호
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• pp.231-237
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• 2021

The ongoing coronavirus disease 2019 (COVID-19) pandemic has highlighted the importance of hospital hygiene and infection control in hospital settings. To raise hygiene awareness among ultrasound technicians, we evaluated the hygiene status of an ultrasound room, in comparison with that of objects used in daily life. Using the swab method, the following surfaces were examined: eight surfaces in the ultrasound room including the ultrasound probes (convex, linear, sector, 3D), ultrasound track ball, ultrasound keyboard, ultrasound gel (sealed and in use) and pillow as well as four surfaces of everyday objects including subway handles, common computer keyboards, common computer mouse, and cell phones. The streak plate technique was used for inoculation into media, which was observed for the formation of bacterial colonies following incubation for 24 h. Six bacterial strains were detected from objects used in the ultrasound room, including methicillin-resistant Staphylococcus aureus. Four strains of bacteria were detected on surfaces of everyday objects. The equipment and accessories used in an ultrasound room can act as vehicles for infecting patients. Establishment of standardized hygiene protocols and periodic training of the staff are recommended to avoid cross-infection.

• Korean Journal of Radiology
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• 제21권8호
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• pp.1018-1023
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• 2020

The coronavirus disease (COVID-19) outbreak has reached global pandemic status as announced by the World Health Organization, which currently recommends reverse transcription polymerase chain reaction (RT-PCR) as the standard diagnostic tool. However, although the RT-PCR test results may be found negative, there are cases that are found positive for COVID-19 pneumonia on computed tomography (CT) scan. CT is also useful in assessing the severity of COVID-19 pneumonia. When clinicians desire a CT scan of a patient with COVID-19 to monitor treatment response, a safe method for patient transport is necessary. To address the engagement of medical resources necessary to transport a patient with COVID-19, our institution has implemented the use of mobile CT. Therefore, we report two cases of COVID-19 pneumonia evaluated by using mobile cone-beam CT. Although mobile cone-beam CT had some limitations regarding its image quality such as scatter noise, motion and streak artifacts, and limited field of view compared with conventional multi-detector CT, both cases had acceptable image quality to establish the diagnosis of COVID-19 pneumonia. We report the usefulness of mobile cone-beam CT in patients with COVID-19 pneumonia.

• 농업과학연구
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• 제49권4호
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• pp.873-883
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• 2022

American plum line pattern virus (APLPV), a member of the genus Ilarvirus in the family Bromoviridae, is one of the plant quarantine pathogens in Korea. In this study, 15 candidate primer sets were designed and examined to develop a reverse transcription polymerase chain reaction (RT-PCR) assay for plant quarantine inspection of APLPV. Using APLPV-infected and healthy samples, the primer sets were assessed for APLPV detection. To confirm the occurrence of nonspecific reactions, six ilarviruses (Apple mosaic virus, Asparagus virus 2, Blueberry shock virus, Prune dwarf virus, Prunus necrotic ringspot virus, and Tobacco streak virus) and 10 target plants (Prunus mume, P. yedoensis, P. persica, P. armeniaca, P. dulcis, P. tomentosa, P. avium, P. glandulosa, P. salicina, and P. cerasifera) were examined. Finally, two primer sets were selected. These primer sets could generate the expected amplicons even with at least 1 ng of the total RNA template in concentration-dependent amplifications. In addition, a positive clone was developed for use as a positive control in the abovementioned RT-PCR assay.

• 한국측량학회지
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• 제31권1호
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• pp.89-97
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• 2013

최근, 지구 온난화에 따른 이상기후로 폭설로 인한 사회 경제적인 피해가 확산되고 있다. 국지적 기습 폭설에 의한 도로지역 피해를 저감하기 위해서는 도로 구간별 강설현황을 정확히 파악하여 대책을 마련하는 것이 중요하다. 본 논문은 도로에 설치되어 있는 CCD 영상을 이용하여 도로 강설강도를 탐지하는 알고리즘을 다룬다. 첫째, 전체 영상 공간 중 차량의 움직임 및 차선이 존재하지 않는 MLZ(MotionLess Zone)를 설정한다. 다음으로, 각 영상의 MLZ를 통과하는 눈 궤적을 Canny 연산자와 제안된 알고리즘을 이용하여 추출한다. 또한 1분 동안 MLZ 안의 눈 궤적의 개수를 나타내는 SII(Snow Intensity Index)를 정의한다. 마지막으로, 69분 동안 계산된 SII 값과 영상을 육안 비교함으로써 본 논문에서 제안된 알고리즘의 유효성을 검증한다. 실험결과 SII의 integration은 실제 적설량과 깊은 연관관계를 나타내었다.

• Journal of Astronomy and Space Sciences
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• 제30권3호
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• pp.193-206
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• 2013

The detector subsystem of the Optical Wide-field Patrol (OWL) network efficiently acquires the position and time information of moving objects such as artificial satellites through its chopper system, which consists of 4 blades in front of the CCD camera. Using this system, it is possible to get more position data with the same exposure time by changing the streaks of the moving objects into many pieces with the fast rotating blades during sidereal tracking. At the same time, the time data from the rotating chopper can be acquired by the time tagger connected to the photo diode. To analyze the orbits of the targets detected in the image data of such a system, a sequential procedure of determining the positions of separated streak lines was developed that involved calculating the World Coordinate System (WCS) solution to transform the positions into equatorial coordinate systems, and finally combining the time log records from the time tagger with the transformed position data. We introduce this procedure and the preliminary results of the application of this procedure to the test observation images.

• 대기
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• 제19권1호
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• pp.37-51
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• 2009

Kinematic characteristics of a heavy rainfall event occurred in Changma front are analyzed using synoptic weather charts, satellite imagery and NCEP(National Centers for Environmental Prediction) / NCAR(National Centers for Atmospheric Research) reanalysis data. The heavy rainfall is accompanied with mesoscale rain clouds developing over the Southwest region of Korea during the period from 0300 LST to 2100 LST 25 June 2006. The surface cyclone in the Changma front is generated and developed rapidly when it meets following vertical conditions: The maximum value of relative vorticity is appeared at 700 hPa and is extended gradually near the surface. It is thought that the vertical structure of relative vorticity is closely related with the descent of strong wind zone exceeding $10ms^{-1}$. The jet core at 200 hPa is shifted southward and extended downward and the low-level jet stream associated with upper-level jet stream appeared at 850 hPa. Kinematic features of heavy rainfall system at cyclone-generating point are as follows: In the generating stage of cyclone, the relative vorticity below 850 hPa increased and the convergence below 850 hPa and the divergence at 400 hPa are intensified by southward movement of jet core at 200 hPa. The heavy rainfall system seems to locate to the south of the exit region of upper-level jet streak; In the developing stage of cyclone, the relative vorticity below 850 hPa and the convergence near surface are further strengthened and upward vertical velocity between 850 hPa and 200 hPa is increased.

• Journal of Astronomy and Space Sciences
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• 제28권4호
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• pp.333-344
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• 2011

An optical tracking system has advantages for observing geostationary earth orbit (GEO) satellites relatively over other types of observation system. Regular surveying for unidentified space objects with the optical tracking system can be an early warning tool for the safety of five Korean active GEO satellites. Two strategies of positioning on the observed image of Communication, Ocean and Meteorological Satellite 1 are tested and compared. Photometric method has a half root mean square error against streak method. Also eccentricity method for initial orbit determination (IOD) is tested with simulation data and real observation data. Under 10 minutes observation time interval, eccentricity method shows relatively better IOD results than the other time interval. For follow-up observation of unidentified space objects, at least two consecutive observations are needed in 5 minutes to determine orbit for geosynchronous orbit space objects.

• 한국항공우주학회지
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• 제44권12호
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• pp.1017-1026
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• 2016

두 가지의 비표면 가시화 기법과 이들 기법의 와류 적용 예를 기술한다. 두 가지 가시화 기법 중 하나는 전통적인 연기선 기법이고, 또 다른 하나는 가정용 초음파 가습기에서 발생하는 미세 수적을 사용하는 기법이다. 연기선 기법은 공기 흐름 속도에 제한이 있으며(0.07 mm 지름의 연기선의 경우 약 5 m/sec), 오염의 문제점이 있지만 매우 정교하고 선명한 연기 유맥선 시트를 발생시킬 수 있다. 이 기법은 3차원 날개의 날개 끝 와류의 가시화에 적용되었다. 초음파 가습기 미세 수적 기법은 연기선 기법에 비하여 공기 흐름 속도를 보다 크게 할 수 있으며(10 m/sec 이상), 독성과 오염의 문제를 해결할 수 있다. 초음파 가습기 미세 수적 기법은 정점 스트레이크를 가지는 이중 삼각날개에서 발생하는 복잡한 와류 시스템의 가시화에 성공적으로 적용되었다.

• 폴리머
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• 제27권4호
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• pp.313-322
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• 2003

상용화제와 교환반응 촉진제 도입에 따른 폴리(에틸렌 테레프탈레이트) (PET)/폴리(메타-자이렌 아디프아미드) (MXD-6) 블렌드의 형태구조 변화와 일축 연신한 블렌드 시료의 변형 형태구조를 조사하였다. 연신시료는 피브릴 구조의 분산상을 보여주었으며, 피브릴 구조는 연신비 증가에 따라서 점차 미세하게 변형되었다. 교환반응 촉진제나 상용화제의 첨가는 계면 접착력 향상에 기여하기보다는 분산상과 연속상 간에 결함을 야기함으로써 피브릴 구조의 균일성을 감소시켰다. H$_{v}$ 모드의 광산란을 이용하여 블렌드 조성과 연신비에 따른 고차구조 변화를 알아보았다. H$_{v}$ 산란패턴으로부터 결정들이 스택을 이루며, 스택은 연신 방향에 대하여 특정한 각도로 배향됨을 알 수 있었다. 분산상과 연속상 내의 결정은 연신비 증가에 따라서 점진적으로 배향되어, 연신비가 6.0인 경우에는 매우 높은 배향 수준을 보여주었다.

• 한국광학회지
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• 제17권4호
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• pp.347-353
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• 2006

전자습윤현상에 기초한 응용 기술들은 액체렌즈로 대표되는 광학분야에서부터, 바이오 칩 등의 생체분야까지 다양하지만, 아직 동적 특성에 대한 이해가 부족하고, 수 미리 초에 발생하는 현상을 측정하는 방법도 매우 제한적이다. 전기 습윤의 동적인 현상을 측정, 평가 하기 위해서는 전압 인가 후 빠르게 움직이는 계면의 동적 현상이 계면의 정보를 표현할 수 있는 수치로 표현되어야 하며, 연속적인 측정이 가능해야 한다. 본 연구에서는 전자습윤 현상에 의한 액체 계면의 동적인 변화를 광량변화를 통해 실 시간적으로 측정할 수 있는 방법을 제시하였고, 실험을 통하여 제시된 방법의 정확도를 검증하였다. 제시된 광량변화 측정 방법은 장치가 단순하여 기존의 방법에 비해 고가의 장비 및 추가의 데이터 분석 기술이 필요치 않으면서도 연속적인 실시간 데이터를 얻을 수 있다.