OWL-Net: A global network of robotic telescopes for satellite observation

Park, Jang-Hyun,Yim, Hong-Suh,Choi, Young-Jun,Jo, Jung Hyun,Moon, Hong-Kyu,Park, Young-Sik,Bae, Young-Ho,Park, Sun-Youp,Roh, Dong-Goo,Cho, Sungki,Choi, Eun-Jung,Kim, Myung-Jin,Choi, Jin Elsevier 2018 ADVANCES IN SPACE RESEARCH Vol.62 No.1

<P><B>Abstract</B></P> <P>The OWL-Net (Optical Wide-field patroL Network) is composed of 0.5-m wide-field optical telescopes spread over the globe (Mongolia, Morocco, Israel, South Korea, and USA). All the observing stations are identical, operated in a fully robotic manner, and controlled by the headquarters located in Daejeon, Korea. The main objective of the OWL-Net is to obtain the orbital information of Korean LEO and GEO satellites using purely optical means and to maintain their orbital elements.</P> <P>The aperture size of the mirror is 0.5 m in the Ritchey-Chretien configuration, and its field of view is 1.1 deg on the CCD sensor. The telescope is equipped with an electrically cooled 4 K CCD camera with a 9-µm pixel size, and its pixel scale is 1 arcsec/pixel. A chopper wheel with variable speed is adopted to obtain multiple points in a single shot. Each observatory is equipped with a heavy-duty environment monitoring system for robust robotic observation. The headquarters has components for status monitoring, scheduling, network operation, orbit calculation, and database management.</P> <P>The test-phase operation of the whole system began in early 2017, although test runs for individual sites began in 2015. Although the OWL-Net has 7 observation modes for artificial satellites and astronomical objects, we are concentrating on a few modes for LEO satellites and calibration during the early phase. Some early results and analysis for system performance will be presented, and their implications will be discussed.</P>

Development of a Reduction Algorithm of GEO Satellite Optical Observation Data for Optical Wide Field Patrol (OWL)

Park, Sun-youp,Choi, Jin,Jo, Jung Hyun,Son, Ju Young,Park, Yung-Sik,Yim, Hong-Suh,Moon, Hong-Kyu,Bae, Young-Ho,Choi, Young-Jun,Park, Jang-Hyun The Korean Space Science Society 2015 Journal of Astronomy and Space Sciences Vol.32 No.3

An algorithm to automatically extract coordinate and time information from optical observation data of geostationary orbit satellites (GEO satellites) or geosynchronous orbit satellites (GOS satellites) is developed. The optical wide-field patrol system is capable of automatic observation using a pre-arranged schedule. Therefore, if this type of automatic analysis algorithm is available, daily unmanned monitoring of GEO satellites can be possible. For data acquisition for development, the COMS1 satellite was observed with 1-s exposure time and 1-m interval. The images were grouped and processed in terms of "action", and each action was composed of six or nine successive images. First, a reference image with the best quality in one action was selected. Next, the rest of the images in the action were geometrically transformed to fit in the horizontal coordinate system (expressed in azimuthal angle and elevation) of the reference image. Then, these images were median-combined to retain only the possible non-moving GEO candidates. By reverting the coordinate transformation of the positions of these GEO satellite candidates, the final coordinates could be calculated.

Benefit of neoadjuvant concurrent chemoradiotherapy for locally advanced perihilar cholangiocarcinoma

Jung, Jang Han,Lee, Hyun Jik,Lee, Hee Seung,Jo, Jung Hyun,Cho, In Rae,Chung, Moon Jae,Park, Jeong Youp,Park, Seung Woo,Song, Si Young,Bang, Seungmin Baishideng Publishing Group Inc 2017 WORLD JOURNAL OF GASTROENTEROLOGY Vol.23 No.18

<P><B>AIM</B></P><P>To clarify the role of neoadjuvant concurrent chemoradiotherapy (NACCRT) followed by surgical resection for localized or locally advanced perihilar cholangiocarcinoma (CCA).</P><P><B>METHODS</B></P><P>We retrospectively reviewed 57 patients who underwent surgical resection with or without NACCRT for perihilar CCA; 12 patients received NACCRT and 45 patients did not received NACCRT. Patients with locally advanced perihilar CCA requiring NACCRT were defined as follows: (1) a mass involving unilateral branches of the portal vein or hepatic artery with insufficient volume of the anticipated remnant lobe; or (2) an infiltrating mass in the main portal vein that was too long for reconstruction, identified at preoperative staging.</P><P><B>RESULTS</B></P><P>The median disease-free survival (DFS) durations of the neoadjuvant and non-neoadjuvant CCRT groups were 26.0 and 15.1 mo, respectively (<I>P</I> = 0.91). The median overall survival (OS) durations of the neoadjuvant and non-neoadjuvant CCRT groups were 32.9 and 27.1 mo, respectively (<I>P</I> = 0.26). The NACCRT group showed a downstaging tendency compared to the non-NACCRT group as compared with the tumor stage confirmed by histological examination after surgery and the tumor stage confirmed by imaging test at the time of diagnosis (<I>P</I> = 0.01).</P><P><B>CONCLUSION</B></P><P>NACCRT does not prolong DFS and OS in localized or locally advanced perihilar CCA. However, NACCRT may allow tumor downstaging and improve tumor resectability.</P>

Development of a Data Reduction algorithm for Optical Wide Field Patrol

Park, Sun-Youp,Keum, Kang-Hoon,Lee, Seong-Whan,Jin, Ho,Park, Yung-Sik,Yim, Hong-Suh,Jo, Jung Hyun,Moon, Hong-Kyu,Bae, Young-Ho,Choi, Jin,Choi, Young-Jun,Park, Jang-Hyun,Lee, Jung-Ho 한국우주과학회 2013 Journal of Astronomy and Space Sciences Vol.30 No.3

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.

Minimum Number of Observation Points for LEO Satellite Orbit Estimation by OWL Network

Maru Park,조중현,조성기,최진,Chun-Hwey Kim,박장현,임홍서,최영준,문홍규,배영호,Sun-youp Park,Ji-Hye Kim,Dong-Goo Roh,Hyun-Jung Jang,Young-Sik Park,정민지 한국우주과학회 2015 Journal of Astronomy and Space Sciences Vol.32 No.4

By using the Optical Wide-field Patrol (OWL) network developed by the Korea Astronomy and Space Science Institute (KASI) we generated the right ascension and declination angle data from optical observation of Low Earth Orbit (LEO) satellites. We performed an analysis to verify the optimum number of observations needed per arc for successful estimation of orbit. The currently functioning OWL observatories are located in Daejeon (South Korea), Songino (Mongolia), and Oukaïmeden (Morocco). The Daejeon Observatory is functioning as a test bed. In this study, the observed targets were Gravity Probe B, COSMOS 1455, COSMOS 1726, COSMOS 2428, SEASAT 1, ATV-5, and CryoSat-2 (all in LEO). These satellites were observed from the test bed and the Songino Observatory of the OWL network during 21 nights in 2014 and 2015. After we estimated the orbit from systematically selected sets of observation points (20, 50, 100, and 150) for each pass, we compared the difference between the orbit estimates for each case, and the Two Line Element set (TLE) from the Joint Space Operation Center (JSpOC). Then, we determined the average of the difference and selected the optimal observation points by comparing the average values.

Development of a Reduction Algorithm of GEO Satellite Optical Observation Data for Optical Wide Field Patrol (OWL)

Sun-youp Park,Jin Choi1,Jung Hyun Jo,Ju Young Son,Yung-Sik Park,Hong-Suh Yim,Hong-Suh Yim,Hong-Kyu Moon,Young-Ho Bae,Jang-Hyun Park 한국우주과학회 2015 Journal of Astronomy and Space Sciences Vol.32 No.3

An algorithm to automatically extract coordinate and time information from optical observation data of geostationary orbit satellites (GEO satellites) or geosynchronous orbit satellites (GOS satellites) is developed. The optical wide-field patrol system is capable of automatic observation using a pre-arranged schedule. Therefore, if this type of automatic analysis algorithm is available, daily unmanned monitoring of GEO satellites can be possible. For data acquisition for development, the COMS1 satellite was observed with 1-s exposure time and 1-m interval. The images were grouped and processed in terms of “action”, and each action was composed of six or nine successive images. First, a reference image with the best quality in one action was selected. Next, the rest of the images in the action were geometrically transformed to fit in the horizontal coordinate system (expressed in azimuthal angle and elevation) of the reference image. Then, these images were median-combined to retain only the possible non-moving GEO candidates. By reverting the coordinate transformation of the positions of these GEO satellite candidates, the final coordinates could be calculated.

기관지 천식에서 impulse oscillometry(IOS)의 유용성

김중선(Jung Sun Kim),김철우(Cheol Woo Kim),박정엽(Jeong Youp Park),정혜원(Hye Won Chung),박중원(Jung Won Park),홍천수(Chein Soo Hong) 대한내과학회 2000 대한내과학회지 Vol.59 No.5

N/A Background : Impulse oscillometry(IOS) is a method to characterize the mechanical properties of respiratory system over wide range of frequency. It's most important advantage is to require minimal cooperations from subject. Therefore it is used to estimate pulmonary function of young children and to study epidemiology of occupational asthma. This study was performed to evaluate the usefulness for the clinical applications of IOS in bronchial asthmatics by estimating the associations between asthma severity and IOS parameters, and the relationships between IOS parameters and conventional spirometry. Methods : 216 subjects with bronchial asthma were enrolled in this study. Subjects were grouped to 3 different groups according to their symptoms and pulmonary functions. Respiratory impedance, resistance (at 5Hz, 20Hz, 35Hz) and resonant frequency were measured by IOS. FEV1, FVC and MMEF were measured with conventional spirometry. Results : There were significant difference of resonant frequency, resistance at 5Hz and 20Hz, resistance difference at 5Hz and 20Hz according to asthma severity(p<0.05, respectively). Resonant frequency, resistance at 5Hz, impedance were significantly correlated with FEV1 (r= -0.55, 0.48, 0.49, p<0.05, respectively). And resistance at 5Hz had similar reproducibility compared to FEV1 (resistance at 5Hz, r= 0.78 vs FEV1, r= 0.79). Conclusion : IOS is an useful and alternative method to evaluate clinical status of brnochial asthmatics. And further studies will be needed to clarify its values for wide range of clinical applications.(Korean J Med 59:522-528, 2000)

흡입제의 올바른 흡입방법 교육 시 전산화 평가프로그램을 이용한 반복교육의 효과

유성근 ( Sung Ken Yu ),박성임 ( Sung Im Park ),박소영 ( So Young Park ),박정규 ( Jung Kyu Park ),김성은 ( Sung Eun Kim ),김정엽 ( Jung Youp Kim ),신경철 ( Kyeong Cheol Shin ),정진홍 ( Jin Hong Chung ),이관호 ( Kwan Ho Lee ) 대한결핵 및 호흡기학회 2007 Tuberculosis and Respiratory Diseases Vol.63 No.6

연구배경: 기관지천식과 만성폐쇄성폐질환과 같은 만성기도질환의 여러 가지 치료법 중 흡입제가 가장 효과적 방법이지만 상당수 환자에서 부정확하게 흡입제를 사용하고 있고, 순응도 또한 낮은 편이다. 저자들은 흡입제의 정확한 사용과 치료 순응도를 높이고자 전산화 흡입제 상담 서비스 프로그램을 개발하여 흡입제 사용에 대한 반복적 교육과 평가를 시행하여 흡입제의 사용 능력 및 치료 순응도에 미치는 효과를 알아보았다. 방법: 만성기도질환 환자를 대상으로 저자들이 개발한 전산화 흡입제 상담 서비스 프로그램을 실시하였다. 2회 이상 방문한 환자를 대상으로 흡입제의 사용능력을 9개 항목에 따라 교육과 함께 평가를 하였으며, 교육 전후 질병의 이해와 약물의 순응도를 알아보았다. 결과: 흡입제 사용 능력이 교육 전후, 1차와 2차, 2차와 3차 방문사이에 유의하게 향상되었다(p<0.05). 자신의 질환에 대한 이해도는 1차 방문에서 70.7%, 2차 방문에서는 78.7%, 3차 방문에서는 78.9%로 증가하였다. 순응도는 2차 방문에서 70.1%, 3차 방문에서는 81.8%로 향상되었다. 결론: 저자들이 개발한 전산화 흡입제 상담 서비스 프로그램은 만성기도질환 환자에서 흡입제 사용능력 및 순응도, 질병에 대한 이해도를 향상시킬 수 있었다. Background: The best way of delivering drugs for the treatment of asthma and chronic obstructive pulmonary disease (COPD) is via the inhaled route of administration. However, many patients use inhaler devices incorrectly. To augment the proper use of inhalation medicine and to improve knowledge of the disease and compliance, we have developed a Computerized Respiratory Service Program and applied the use of this program to educate patients. Methods: Prospectively, this study was performed in 164 patients with asthma or COPD prescribed with inhaled medication. When inhalation medication was first prescribed, education using a drug model was conducted two times and thereafter every month. In addition, education using a drug model was conducted and the ability of the patient to use inhalation medicine properly was evaluated. Results: A total of 164 patients participated in the sessions more than two times and received education. Fifty-seven patients participated in three sesions. After the patients received education one time, the ability of these patients to use an inhaler had an average score of 20.6. After the patients received education two times, the average score was 21.9. After the patients received education three times, the average score was 22.3, a further increase. The compliance of using the inhaler was 70.1% at the second session and increased to 81.8% at the third session. Conclusion: Feedback education using the Computerized Respiratory Service Program will increase the ability of the patient to use an inhaler and consistent education can maintain patient compliance with inhaler use. (Tuberc Respir Dis 2007;63:491-496)

무증상 천식 환자에서 impulse oscillometry 의 유용성

이재훈,홍천수,박중원,김철우,박정엽,박윤수,박병규 대한알레르기학회 2001 천식 및 알레르기 Vol.21 No.3

Background : Impulse oscillometry (IOS) is a valuable method for evaluating respiratory function in a patient with bronchial asthma. There have been no reports on compliance assessment of the remodeled airway by estimation of the relationship between resistance and breathing volume in asymptomatic asthma using IOS. Objective: This study was performed to evaluate whether IOS could distinguish asymptomatic asthma from healthy control and detect altered physiology of the airway due to airway remodeling in asymptomatic asthmatic patients with normal pulmonary function. Method: 16 healthy and 16 asymptomatic patients with bronchial asthma were asked to breathe with the usual tidal volume (Vt) and with twice the amount of Vt. Using IOS, impedance, resistance for frequency at 5Hz and 20 Hz, reactance, and resonant frequency were measured. Results: Resonant frequency was significantly higher in asymptomatic asthma than in healthy control for breathing with both usual Vt and twice the amount of Vt (mean±S.E.M. 16.351.44 Hz vs 13.34±0.66 Hz, 16.27±0.72 Hz vs 13.68±0.66 Hz, p$lt;0.05 respectively), but the discriminant power of resonant frequency for distinguishing asymptomatic asthma from healthy control was low. There were no significant differences of other IOS parameters between asthma and control groups. Compared with control group, asymptomatic asthma group showed no significant change of IOS parameters according to breathing volume change. Conclusion: In this study, we could not find any IOS parameters sensitive enough to detect altered physiology of the remodeled airway in patients with asymptomatic bronchial asthma. Further studies are recommended to improve sensitivity of IOS method for investigating airway physiology in bronchial asthma.

The Expression of Programmed Death-Ligand 1 on Immune Cells Is Related to a Better Prognosis in Biliary Tract Cancer

Kwon Sung Chan,Bang Seungmin,Park Young Nyun,Park Ji Hoon,Kim So Jeong,Jo Jung Hyun,Chung Moon Jae,Park Jeong Youp,Park Seung Woo,Song Si Young,Park Eunhyang,Lee Hee Seung 거트앤리버 소화기연관학회협의회 2023 Gut and Liver Vol.17 No.6

Background/Aims: Programmed death-ligand 1 (PD-L1) expression in tumor cells is associated with a poor biliary tract cancer (BTC) prognosis; tumor-infiltrating immune cells in the tumor microenvironment are associated with a better prognosis. The effect of PD-L1 expression on immune cells on survival is unclear. We investigated the relationship between PD-L1 expression in immune cells and BTC prognosis. Methods: PD-L1 expression was evaluated using an anti-PD-L1 22C3 mouse monoclonal primary antibody, and its relationships with clinical characteristics and prognosis were analyzed using the Cox proportional hazard model to investigate the prognostic performance of PD-L1 in BTC. Results: Among 144 analyzed cases, patients with positive PD-L1 expression in tumor cells and negative PD-L1 expression in immune cells showed poorer overall survival rates than those exhibiting other expressions (tumor cells: hazard ratio [HR]=1.023, p<0.001; immune cells: HR=0.983, p=0.021). PD-L1 expression in tumor cells was an independent predictor of poor overall survival (HR=1.024, p<0.001). In contrast, PD-L1 expression in immune cells was a predictive marker of good prognosis (HR=0.983, p=0.018). Conclusions: PD-L1 expression in immune cells may be used as an independent factor to evaluate the prognosis of patients with BTC.