로오란C의 9970 chain과 5970 chain을 중심으로, 양 시스템을 이용하여 위치를 측정하였을 때의 측정위치의 정도를 평가할 수 있는 GDOP를 시뮬레이션으로 계산하여, 현 송신국의 이설에 따른 변화, 송신국의 시뮬레이션위치에 따른 변화 및 유효범위에 관하여 검사 분석한 결과를 요약하면 다음과 같다. 1. 9970 chain은 Z 종국이 과거 Yap도에서 현재의 Guam도로 이설된 후의 등GDOP선도에서, 주국의 이남부분을 보면 Yap도였을 때의 GDOP 2.0과 Guam도였을 때의 GDOP 3.0이 거의 일치하였으며, 전체적으로 GDOP의 값이 높아져 위치측정의 정도는 낮아져 있다. 2. 9970 chain의 Z 종국이 영토문제로 인접국인 일본으로 이관되지 않고 폐쇄되는 경우는 남측인 남지나해 및 Guam도 부근해역은 GDOP의 값이 크게 높아져, 5.0의 등GDOP선이 Fig.3에서는 2.0, Fig.4에서는 3.0의 등 GDOP선과 대개 일치하였다. 3. 9970 chain의 X 종국과 5970 chain의 X 종국은 송신국이 이관될 경우 전파의 전파경로 및 배치상태상 재배치하여 위치의 정도를 높이고 이용범위를 넓힐 필요성이 있다.

원예작물을 종합적으로 재배하는 원예시험장에서 원예작물에 직접, 간접으로 많은 피해를 주고있는 진딧물을 Yellow Water Trap을 5월 1일부터 10월 31일까지 설치하여 조사한바 다음과 같은 결과를 얻었다. 1. 본 시험장시는 24종의 매개진딧물을 포함하여 120여종이 분포되어 있다. 2. 본 시험장에 분포된 120여종 중에 이상을 차지하는 우세종 10종은 다음과 같다. * 조급나무진딧물(Aphis spiraecola ) * 아카시아진딧물(Aphis craccivora ) * 복숭아혹진딧물(Myzus persicae ) 자바못털진딧물(Capitophorus hippophaes javanicus H.R. ) 층층나무진딧물(Anoecia fulviabdominalis ) * 목화진딧물(Aphis gossypii ) * 보리수염진딧물(Macrosiphum avenae ) 가시 진딧물(Cervaphis quercus ) * 무우테두리진딧물(Lipaphis erysimi ) 쑥못털진딧물식물(Pleotrichophorus chrysanthemi )(* : 바이러스매개진딧물) 3. 식물바이러스를 매개하는 24종의 진딧물은 전체 진딧물수의 를 차지한다. 4. 본시험장의 진딧물 발생소장을 수원의 4개년(1967-'70) 것과 비교한 바 작물이 자라는 봄. 여름에는 살충제를 뿌리기 때문에 수원의 밀도보다 낮으나 작물의 수확이 끝난 10월에는 살충제살포를 중지하고 또 이 시기는 진딧물이 월동숙주로 이주하기 때문에 10월 중순에 밀도가 갑자기 상승하여 년중 최고곡선을 이룬다. 5. 진딧물 방제를 위해서 작물에만 살충제를 살포하는 것으로 그치는데 주위의 잡초나 숙주식물에도 아울러 살포해야한다. 그리고 작물의 수확이 끝난 10월중에도 원동숙주에 살충제를 살포하여 진딧물의 월동량을 감소시키므로써 다음해 봄에 발생량을 감소시키는 예비책을 써야한 것이다. 진딧물은 원예작물에는 어느 해충보다도 피해가 크다는 것은 주지의 사식이나 이것의 발생은 해에 따라, 기상조건의 변화에 따라 달라지므로 한번의 조사로는 만족할 수 없다. 그러므로 앞으로 영구적인 사업으로 매년 발생상황을 계속적으로 조사해야 될 줄로 믿는다.

This study was conducted to investigate the response of the human body to stress induced by wall recording of subway stations in the city center. The experiment was conducted as a simulation exercise, and six images were selected and produced based on Subway Line 2, a representative underground space in Seoul. The study participants included 24 male and female college students. A three-minute experiment was conducted, during which the participants were shown the control image and green wall image once each. To measure psychological status, the following measurement indicators were used: Semantic Differential, Positive Affect and Negative Affect Schedule and State-Trait Anxiety Inventory. Physiological changes were investigated by tracking participants’ heart rate and blood pressure. Results showed that parasympathetic and sympathetic nerves were activated in the presence of the green wall in the subway station. The psychological evaluation analysis revealed that negative affect toward underground space decreased, while positive affect increased. This study found that the green wall in subway stations has a stable effect on the human body, both psychologically and physiologically. In the future, green walls in underground spaces can be used to reduce psychological stress and increase physiological relaxation.

The auroral observation has been started at Jang Bogo Station (JBS), Antarctica by using a visible All-sky camera (v-ASC) in 2018 to routinely monitor the aurora in association with the simultaneous observations of the ionosphere, thermosphere and magnetosphere at the station. In this article, the auroral observations are introduced with the analysis procedure to recognize the aurora from the v-ASC image data and to compute the auroral occurrences and the initial results on their spatial and temporal distributions are presented. The auroral occurrences are mostly confined to the northern horizon in the evening sector and extend to the zenith from the northwest to cover almost the entire sky disk over JBS at around 08 MLT (magnetic local time; 03 LT) and then retract to the northeast in the morning sector. At near the magnetic local noon, the occurrences are horizontally distributed in the northern sky disk, which shows the auroral occurrences in the cusp region. The results of the auroral occurrences indicate that JBS is located most of the time in the polar cap near the poleward boundary of the auroral oval in the nightside and approaches closer to the oval in the morning sector. At around 08 MLT (03 LT), JBS is located within the auroral oval and then moves away from it, finally being located in the cusp region at the magnetic local noon, which indicates that the location of JBS turns out to be ideal to investigate the variabilities of the poleward boundary of the auroral oval from long-term observations of the auroral occurrences. The future plan for the ground auroral observations near JBS is presented.

For the vast majority of geostationary satellites currently in orbit, station keeping activities including orbit determination and maneuver planning and execution are ground-directed and dependent on the availability of ground-based satellite control personnel and facilities. However, a requirement linked to satellite autonomy and survivability in cases of interrupted ground support is often one of the stipulated provisions on the satellite platform design. It is especially important for a geostationary military-purposed satellite to remain within its designated orbital window, in order to provide reliable uninterrupted telecommunications services, in the absence of ground-based resources due to warfare or other disasters. In this paper we investigate factors affecting the robustness of a geostationary satellite’s orbit in terms of the maximum duration the satellite’s station keeping window can be maintained without ground intervention. By comparing simulations of orbit evolution, given different initial conditions and operations strategies, a variation of parameters study has been performed and we have analyzed which factors the duration is most sensitive to. This also provides valuable insights into which factors may be worth controlling by a military or civilian geostationary satellite operator. Our simulations show that the most beneficial factor for maximizing the time a satellite will remain in the station keeping window is the operational practice of pre-emptively loading East-West station keeping maneuvers for automatic execution on board the satellite should ground control capability be lost. The second most beneficial factor is using short station keeping maneuver cycle durations.

Korea Polar Research Institute (KOPRI) installed an ionospheric sounding radar system called Vertical Incidence Pulsed Ionospheric Radar (VIPIR) at Jang Bogo Station (JBS) in 2015 in order to routinely monitor the state of the ionosphere in the auroral oval and polar cap regions. Since 2017, after two-year test operation, it has been continuously operated to produce various ionospheric parameters. In this article, we will introduce the characteristics of the JBS-VIPIR observations and possible applications of the data for the study on the polar ionosphere. The JBS-VIPIR utilizes a log periodic transmit antenna that transmits 0.5–25 MHz radio waves, and a receiving array of 8 dipole antennas. It is operated in the Dynasonde B-mode pulse scheme and utilizes the 3-D inversion program, called NeXtYZ, for the data acquisition and processing, instead of the conventional 1-D inversion procedure as used in the most of digisonde observations. The JBS-VIPIR outputs include the height profiles of the electron density, ionospheric tilts, and ion drifts with a 2-minute temporal resolution in the bottomside ionosphere. With these observations, possible research applications will be briefly described in combination with other observations for the aurora, the neutral atmosphere and the magnetosphere simultaneously conducted at JBS.

An application of an integrated climate extreme index (CEI) is presented, that quantifies observed climate change of South Korea by various five indicators. Based on an annual basis surface observation station data, climate extreme indicators that measure the fraction of the stations in South Korea are analyzed. Results for the annual CEI indicate that the area experiencing much above-normal maximum and minimum temperatures in recent years has been increased. The extremes in much greater-than-normal number of days with or without precipitation has a large interannual variability similar with much above and below normal standardized precipitation index. Results from above-normal proportion of heavy daily precipitation show a more pronounced increasing feature from 1990’s to the early 2010’s. Five indicators in CEI had distinct contrasting features which indicates that CEI can be a useful tool in providing the information on the percentage of the climate in South Korea that experienced various kinds of extreme conditions during any given year or period.

광주 선교 스테이션은 의료활동을 통해서 복음의 접촉점을 가졌을 뿐만 아니라, 당시 열악한 위생상태와 질병을 통하여 죽어가는 사람들을 치료해 주었다. 특히 광주 선교스테이션의 한센병과 폐결핵환자에 대한 치료는 헌신적이었다. 많은 사람들이 치료를 받고 새로운 삶을 살아가게 되었고, 그리스도의 사랑을 실천함으로 이를 통하여 주님께 돌아오는 이들이 많았다. 환자들을 찾아가기도 했다. 의사가 없는 지역에 순회진료를 했고, 그리고 농어촌 의료봉사, 보건예방교육 등을 통하여 국민건강 증진과 위생에 대한 인식을 변화시켰다. 의료활동은 광주지역을 넘어서 여수와 순천으로 그리고 남부지역으로 확대되었다. 또한 치료와 회복 그리고 재활 프로그램을 통하여 사회의 소중한 일원으로 살아가게 했고, 의료인재를 양성해서 장차 선교한국으로의 토대를 마련했다.

일제의 추방으로 폐쇄되었던 전주 스테이션은 1947년에 복구되어 활동을 시작했는데, 1948년에는 9명의 선교사들이 활동하였다. 이들 가운데 인돈, 위인사, 조요셉 등은 노회원으로 교회들의 목회활동을 도왔지만, 주로 교육분야와 의료분야에서 활동하였다. 인돈 부부는 신흥과 기전의 교장으로, 윈과 폰테인은 한예정신학교를 위해 사역하였고, 구바울 부부와 변마지는 예수병원에서 사역하였다. 해방 후 일제에 의해 강제로 합병되었던 전주 시내 5개 교회들이 문을 다시 열면서 교회가 성장하기 시작하여 1952년에는 12개로 늘어났다. 1952년부터 기장과 예장으로 총회가 분열하면서 노회도 분열하였고, 1959년에 다시 예장 합동과 통합으로 분열하였다. 이 과정에서 1960년에 기장 전북 노회는 16개의 교회로, 통합 전북노회는 1962년에 자립 9개와 미자립 6개로 늘어났고, 합동은 1960년에 7개로 출발하였다. 인톤 선교사가 1946년 7월 귀국한 후에 신흥과 기전 학교의 복교가 추진되어 11월에 문을 열었고 1950년에 중고등학교로 분리되었다. 강흥모에 의해 1955년에 영생중학교와 영생고등학교를 인가받았고 1963년에 영생여자중학교를 인가받았다. 그 결과 1960년대에 전주에서 기독교학교가 중학교에서 차지하는 비중이 20-30%이고, 고등학교에서는 30-40%를 차지하였다. 고등교육기관은 강흥모가 세운 영생대학교와 전주공업전문학교가 오늘 날 전주대학교와 전주비전대학으로, 여자성경학교였던 한예정성경학교가 1968년에 한일여자신학교로, 예수병원의 간호기술학교는 1973년에 간호전문학교로, 기전여자고등학교에서 1974년에 기전전문학교로 발전하였다. 전주예수병원은 1948년 45병상으로 출발하여 1960년에는 160개 병상의 종합병원이자 지방거점병원으로 발전하였다. 구바울, 설대위, 켈리, 필립 등의 다양한 분야의 의사들이 진료를 하였고, 전문수련의 병원으로서의 역할을 통해 1960년대에는 외과, 이비인후과, 안과, 신경외과 등과 함께 암전문치료 병원으로 발전하였다. 전주는 미션 스테이션의 복구와 전주 장로교회들의 협력을 통해 교육과 의료의 인프라를 구축하고 많은 교회들이 설립되어 최근에도 27.6%의 높은 복음화율을 가진 도시가 되었고 많은 기독교 관광장원을 활용하여 기독교를 지역의 특성으로 활용하는 도시가 되었다.

본 연구에서는 Cosmic-ray 토양수분량 관측시스템 구축 시 필요한 검증 네트워크 설계 기법 개발에 목적을 두고 유전율식(dielectric constant) 장비인 Frequency Domain Reflectometry (FDR)와 연계하여 Cosmic-ray 검증시스템을 구축·운영하였다. Cosmic-ray 검증시스템 평가에 필요한 시범지역은 기존 계측 장비와의 연계성과 다양한 수문자료의 활용성을 고려하여 설마천 유역에 구축하였다. 시범지역은 Cosmic-ray 장비와 FDR 센서(10개소)로 구축하였으며 2018년 7월부터 현재까지 운영되고 있다. 본 연구에서는 검증시스템의 신뢰도를 높이기 위해 코어법(soil core sampling method)을 통해 산출한 용적수분함량(volumetric water content)을 유전율식 장비와 정기적으로 검증하였다. 연구기간 중 수행한 코어법과 FDR 센서를 검증한 결과, 두 자료의 통계량이 bias=-0.03 m3/m3과 RMSE=0.03 m3/m3의 유의한 값을 보였다. 또한 연구기간 동안 FDR 센서의 시계열 특성은 모든 강우에 정상적으로 반응하였다. 그러나 일부 지점에서는 낙엽 및 캐노피의 차단과 상부사면의 유출 등으로 인해 상이한 특성을 보였다. Cosmic-ray 영향원(influence line) 내 FDR 센서의 대표성 분석은 시간 안정성 해석법(temporal stability analysis, TSA)을 이용하여 토심별(10 cm, 20 cm, 30 cm, 40 cm)로 분석하였다. 10개소에 대한 토심별 토양 수분량의 대표성을 TSA로 분석한 결과, 토심 10 cm에서는 FDR 5, 토심 20 cm에서는 FDR 8, 토심 30 cm에서는 FDR 2, 토심 40 cm에서는 FDR 1에서 가장 우수한 대표 특성을 보였다. 본 연구의 시범지역 운영 기간이 짧다는 한계는 있지만 지금까지의 분석 결과를 토대로 하여 볼 때, Cosmic-ray 관측시스템 구축 시에는 검증 장비로는 유전율식을 활용하고, Cosmic-ray 영향원 내 토양수분량의 대표성 분석은 TSA 방법으로 수행하는 것이 바람직할 것으로 판단된다.

Korea Astronomy and Space Science Institute (KASI) has been developing the space optical and laser tracking (SOLT) system for space geodesy, space situational awareness, and Korean space missions. The SOLT system comprises satellite laser ranging (SLR), adaptive optics (AO), and debris laser tracking (DLT) systems, which share numerous subsystems, such as an optical telescope and tracking mount. It is designed to be capable of laser ranging up to geosynchronous Earth orbit satellites with a laser retro-reflector array, space objects imaging brighter than magnitude 10, and laser tracking low Earth orbit space debris of uncooperative targets. For the realization of multiple functions in a novel configuration, the SOLT system employs a switching mirror that is installed inside the telescope pedestal and feeds the beam path to each system. The SLR and AO systems have already been established at the Geochang station, whereas the DLT system is currently under development and the AO system is being prepared for testing. In this study, the design and development of the SOLT system are addressed and the SLR data quality is evaluated compared to the International Laser Ranging Service (ILRS) tracking stations in terms of single-shot ranging precision. The analysis results indicate that the SLR system has a good ranging performance, to a few millimeters precision. Therefore, it is expected that the SLR system will not only play an important role as a member of the ILRS tracking network, but also contribute to future Korean space missions.

A Fabry-Perot interferometer (FPI) for mesospheric observations was installed at King Sejong Station (62.2°S, 58.9°W) in Antarctica in 2017. For the initial validation of the FPI measurements, we compare neutral wind data recorded with the FPI with those from a Meteor Radar (MR) located nearby. The overall characteristics of the FPI and MR winds of both OH 892.0 nm (87 km) and OI 557.7 nm (97 km) airglow layers are similar. The FPI winds of both layers generally match the MR winds well on the observed days, with a few exceptions. The correlation analysis of the FPI and MR wind data shows that the correlation coefficients for the zonal winds at 87 and 97 km are 0.28 and 0.54, respectively, and those for the meridional winds are 0.36 and 0.54, respectively. Based on the assumption that the distribution of the airglow emissions has a Gaussian function with respect to the altitude, we calculated the weighted mean winds from the MR wind profile and compared them with the FPI winds. By adjusting the peak height and full width at half maximum of the Gaussian function, we determined the change of the correlation between the two winds. The best correlation for the OH and OI airglow layers was obtained at a peak height of 88–89 km and 97–98 km, respectively.

Jang Bogo Station (JBS), the second Korean Antarctic research station, was established in Terra Nova Bay, Antarctica (74.62°S 164.22°E) in February 2014 in order to expand the Korea Polar Research Institute (KOPRI) research capabilities. One of the main research areas at JBS is space environmental research. The goal of the research is to better understand the general characteristics of the polar region ionosphere and thermosphere and their responses to solar wind and the magnetosphere. Ground-based observations at JBS for upper atmospheric wind and temperature measurements using the Fabry-Perot Interferometer (FPI) began in March 2014. Ionospheric radar (VIPIR) measurements have been collected since 2015 to monitor the state of the polar ionosphere for electron density height profiles, horizontal density gradients, and ion drifts. To investigate the magnetosphere and geomagnetic field variations, a search-coil magnetometer and vector magnetometer were installed in 2017 and 2018, respectively. Since JBS is positioned in an ideal location for auroral observations, we installed an auroral all-sky imager with a color sensor in January 2018 to study substorms as well as auroras. In addition to these observations, we are also operating a proton auroral imager, airglow imager, global positioning system total electron content (GPS TEC)/scintillation monitor, and neutron monitor in collaboration with other institutes. In this article, we briefly introduce the observational activities performed at JBS and the preliminary results of these observations.

The changes in extreme daily rainfall totals in Punjab Province, Pakistan, during the period (1981- 2014) are examined in this study. The analysis was focused on the extreme annual and monthly rainfall events, by processing the exceeding of the daily rainfall over various thresholds, which are indicators for the incidence of extreme rainfall events. To analyze the changes in extreme rainfall events and trends of the time series of the annual number of extreme rainfall days (%) the thresholds of 30mm and 50mm has been estimated. Evidence from the twelve stations considered shows that there is an increase in annual number of extreme rainfall days (%) in dataset. These changes of heavy and extreme rainfall events pronounce significant environmental consequences which cause considerable impact on society.

We have identified the subway of structures as subway station users complained of vibrations from a structures when they walked through middle stairs of escalator. As a result of converting the vibration level to the conversion rate, it was measured at 3.846mm/s(82.7dB) on the B1st floor and 0.966mm/s(70.7dB) on the B2nd floor. These results are higher than the domestic standard of 65dB and lower than the international standard of under 5mm/s. It is felt well with the human body, but the structure is considered to be harmless. Therefore, it is deemded the structure is safe to usue. As the result of measuring the national frequency, the stairs on the B1st floor to be 3.01Hz and the stairs B2nd floor to be 5.36Hz. We consider that the users feel discomfort and anxiety on the B1st floor, where displacement and vibrations are higher.