시설잎들깨에 발생하는 차먼지응애를 친환경적으로 방제하고자 피레스럼(pyrethrum)의 농도별 방제효과를 조사하였다. 2%, 4%, 6% 피레스럼 1,000배 희석액에 대한 차먼지응애 약·성충의 생충률은 약제 살포 3일 후 각각 58.1%, 27.5%, 22.7% 였으며, 5일 후 각각 73.4%, 37.3%, 30.6% 였다. 차먼지응애에 대하여 방제효과가 우수했던 6% 피레스럼 1,000배액와 화학약제인 밀베멕틴(milbemectin EC 2%) 1,000 배액을 이용하여 약제 살포 후 차먼지응애에 대한 약·성충 밀도를 지름 1cm 잎디스크 내에서 조사한 결과, 6% 피레스럼을 차먼지응애의 발생이 예측되는 시기인 5월 10일부터 10일 간격으로 사용한 곳에서 밀도가 낮게 유지된 반면 차먼지응애의 피해가 확인된 후 화학약제를 사용한 곳에 서는 1주 간격 1~2회의 살포로는 차먼지응애의 밀도를 낮출 수 없었으며 1주 간격 3회 살포 이후 밀도가 낮아졌다. 따라서, 시설잎들깨에서 효과 적으로 차먼지응애를 방제하기 위해서는 발생이 예측되는 초기부터 방제제를 사용하는 것이 효과적이다.
차먼지응애(Polyphagostarsonemus latus)는 잎들깨에서 잎을 직접적으로 가해하여 농가 소득에 치명적인 피해를 야기하고 있지만 표본단위가 설정되어 있지 않아 적절한 표본 조사가 이루어지지 못하는 상황이다. 따라서, 본 연구에서는 잎들깨의 주내분포 연구를 통하여 표본단위와 최적표본수를 제시하고자 수행하였다. 차먼지응애는 하나의 들깨잎에서 엽병 부위를 중심으로 개체가 형성되어 전체잎으로 퍼져나가는 특징을 보였으며, 이때 기간은 접종 후 25일이 소요되었다. 단위면적당 차먼지응애의 밀도를 조사한 결과, 접종 후 경과 기간에 관계없이 신초에서의 밀도가 중엽과 성엽보다 높아 대표성을 띠기 때문에 표본단위는 신초가 적합할 것으로 판단되었다. 주당 표본수는 1개의 신초에 있는 알과 약성충 모두를 조사할 경우 정밀도 0.25를 충족할 것으로 추정되었다. 따라서, 시설 잎들깨에서 차먼지응애의 표본조사는 주당 1개의 신초에서 알과 약성충을 조사 할 때 가장 정확도가 높고 경제적이었다.
Korea has numerous astronomical resources, such as observational records, star maps, and a wealth of literature, covering the period from the Three Kingdoms (54 BC - 932 AD) to the Joseon Dynasty (1392 - 1910 AD). The research activities related to these resources have been limited to those by individual researchers. It is now necessary to conduct research by efficiently and systematically collecting and managing Korean astronomical records using an accessible Web environment. The purpose of this study is to complete a system that enables researchers systematically to collect and verify a large number of historical records related to astronomical phenomena in a Web environment. In 2017, a preliminary survey was conducted, and the requirements pertaining to an implementation target system were devised. In addition, a joint development plan was carried out by the developer, lasting three months in 2018. Although the system is relatively simple, it is the first system to be attempted in the historical astronomy field. In order to proceed with the systematic development, the software development methodology is applied to the entire process from deriving the requirements of researchers to completing the system. The completed system is verified through integrated function and performance tests. The functional test is repeated while modifying and testing the system based on various test scenarios. The performance test uses a performance measurement test tool that takes measurements by setting up a virtual operation environment. The developed system is now in normal operation after a one-year trial period. Researchers who become authorized to use the system can use it to verify the accuracy of data and to suggest improvements. The collected feedback will be reflected in future systems, and Korean astronomical records will be available for use internationally through a multilingual service.
충남 금산지역 잎들깨 시설하우스에서 차먼지응애(Polyphagotarsonemus latus)는 5월 하순 최초 발생하기 시작하여 6월 중순에 1차 최대 발생양상을 보인 후 7월 상순부터 급격히 밀도가 증가하여 7월 중순 가장 밀도가 높은 2차 최대 발생양상을 보였다. 방제방법에 따라 발생양상에는 차이가 없었으나 밀도에는 차이를 보여 화학약제를 사용하는 하우스에서 가장 높았고 유기농업자재를 사용하는 하우스에서 가장 낮았다. 이는 크기가 작아 육안으로 관찰할 수 없는 차먼지응애를 방제하기 위해 화학약제를 사용할 경우, 농약 잔류 문제로 지속적인 사용을 못하므로 밀도가 높아지고, 유기농업자재를 사용하는 경우에서는 농약잔류에 대한 걱정 없이 유기농업자재를 지속적으로 사용함으로써 방제가 이루어졌던 것으로 판단된다. 잎들깨 주간내 발생양상을 조사한 결과, 차먼지응애는 접종 25일 후 최대 발생밀도를 보였고, 중엽, 성엽, 신초의 순으로 알과 약성 충의 총밀도가 조사되었다. 그러나 엽장과 차먼지응애 밀도와의 상관성 분석 결과, 상관성이 없어 차먼지응애 발생예찰시 어떤 샘플을 채취해도 정확한 예찰이 이루어질 것으로 판단된다.
Song, I-Yeong (1619 ~ ?) was an active astronomer in the Joseon dynasty at the era of adopting the Shixian-li, Chinese calendar in Qing dynasty. His astronomical contribution was recorded in Annals of the Joseon Dynasty, Diary of the Royal Secretariat, Comparative Review of Records and Documents-Its Revision and Enlargement, and Treatise on the Bureau of Astronomy. In addition the details on his life and works were found at the genealogies of the Song Family from Yeonan and the Kim Family from Seonsan. His major astronomical activities can be summarized in three items. First, as a specialist astronomer, he has attempted to make a systematic observation of two comets. Second, he designed and fabricated the Jamyeong-jong, the weight-powered armillary clock, which became a typical model of the astronomical clock in the Joseon dynasty. Last, he served as a royal astronomical professor, greatly contributing on implementing the Shixian-li. Song has concentrated on performing astronomical duties for his royal official service time. Song is regarded as an important astronomer who made it possible to enforce the Shixian-li until the late Joseon dynasty.
We investigate the life of Lee Cheon (1376-1451) who was closely connected with astronomy during the reign of King Sejong of the Joseon dynasty. Lee Cheon is widely regarded as one of the outstanding scientists of King Sejong’s period. However, his contributions to the development of the astronomy during the period have not been enlightened. Based on the historical records on the life and achievements of Lee Cheon, mainly referring to the Joseonwangjosillok (Annals of the Joseon Dynasty), we address three important points. First, Lee Cheon was a distinguished administrator who filled various government posts. Second, he was a supervising engineer in public works and metal smelting during his position in military. Third, he was a scientific technician and manufactured precision equipment such as the metal movable type sets. By virtue of these aspects, Lee Cheon was taken into confidence by King Sejong on the Ganui-dae project (i.e., manufacture various astronomical instruments and construct their platform in order to make a calendar suitable for Joseon). During the period of this project, Lee Cheon not only supervised the construction of the Ganui (simplified armillary sphere) and Ganui-dae (platform for astronomical instruments) but also participated in the production of the astronomical instruments such as Gyupyo (Gnomon) and Honcheonui (Armillary Sphere). In conclusion, we regard Lee Cheon as one of the astronomers who led a great advance in astronomy during King Sejong’s era.
The life and astronomical activity of Lee Deok-Seong (李德星, 1720-1794) was studied using various historical sources, including the astronomical almanac, Seungjeongwon-Ilgi (Daily records of Royal Secretariat of Joseon dynasty), and the Gwansang-Gam’s logbooks during Joseon dynasty (A.D. 1392– 1910). We present the results of the study including the following main findings. First, from the investigation of Lee’s family tree, we find that a number of his relatives were also astronomers, notably Samryeok-Gwan (三曆官, the post of calendrical calculation). Second, we find that he took part in the compilation of an annual astronomical almanac over a period of at least 16 years. His major achievements in the astronomy of the Joseon dynasty were to establish a new method of calendar-making calculation and to bring astronomical materials to the Joseon court through a visit to China. The Joseon dynasty enforced the Shixianli (時憲曆, a Chinese calendar made by Adam Shall) in 1654 without fully understanding the calendar. So an astronomer and an envoy were dispatched to China in order to master the intricacies of the calendar and to learn as much of Western science as was available in that time and place. Lee Deok-Seong worked at the Gwansang-Gam (觀象監, Royal Astronomical Bureau) during the reigns of King Yeongjo (英祖) and Jeongjo (正祖). As best as we can ascertain in relation with the calculations in the Shixian calendar, Lee visited China four times. During his trips and interactions, he learned a new method for calendar-making calculations, and introduced many Western-Chinese astronomical books to Joseon academia. Lee greatly improved the accuracy of calendrical calculations, even while simplifying the calculation process. With these achievements, he finally was promoted to the title of Sungrok-Daebu (崇祿 大夫), the third highest grade of royal official. In conclusion, history demonstrates that Lee Deok-Seong was one of the most outstanding astronomers in the late-Joseon dynasty.
고성능 투명 전극의 개발은 유기 태양 전지, 유기 발광 다이오드와 같은 저가형 유연 유기 광전자 소자의 개발에 매우 중요하다. 가장 널리 쓰이고 있는 투명전극인 indium tin oxide (ITO)는 비싼 가격과 잘 깨어지는 특성 을 가지고 있어서 저가형 유연 전자 소자의 개발에 많은 제한을 주고 있으며, 이를 극복하기 위한 대체 투명 전극의 개발에 대한 연구가 활발히 진행되고 있다. 은 나노와이어(silver nanowire, AgNW)는 우수한 전기 전도도와 광 투과 도를 가지고 저렴하며 뛰어난 유연성 때문에 ITO의 대체 투명전극으로서 큰 각광을 받고 있다. 그러나 AgNW의 거 친 표면은 유기 광전자 소자의 누설전류를 크게 증가시켜서 소자의 효율을 떨어뜨리기 때문에 이를 극복하는 기술의 개발이 시급한 실정이다. 본 연구에서는 UV 광 경화성 접착제를 이용하여 AgNW를 PET기판으로 transfer 시키는 방법으로 AgNW가 매몰된 유연 전도성 투명 기판을 제작하였으며, 이 기판은 낮은 표면 거칠기, 낮은 면저항과 높은 광투과도를 보여준다. 본 연구에서 개발된 AgNW가 매몰된 유연 전도성 투명 기판은 유기전자소자의 대체투명전극 으로 활용될 수 있는 가능성을 보여준다.
KASI (Korea Astronomy and Space Science Institute) has developed an SLR (Satellite Laser Ranging) system since 2008. The name of the development program is ARGO (Accurate Ranging system for Geodetic Observation). ARGO has a wide range of applications in the satellite precise orbit determination and space geodesy research using SLR with mm-level accuracy. ARGO-M (Mobile, bistatic 10 cm transmitting/40 cm receiving telescopes) and ARGO-F (Fixed stationary, about 1 m transmitting/receiving integrated telescope) SLR systems development will be completed by 2014. In 2011, ARGO-M system integration was completed. At present ARGO-M is in the course of system calibration, functionality, and performance tests. It consists of six subsystems, OPS (Optics System), TMS (Tracking Mount System), OES (Opto-Electronic System), CDS (Container-Dome System), LAS (Laser System) and AOS (ARGO Operation System). In this paper, ARGO-M system structure and integration status are introduced and described.
A space launch vehicle system represents a typical example of large-scale multi-disciplinary systems, consisting of subsystems such as mechanical structure, electronics, control, telecommunication, propulsion, material engineering etc. A lot of cost is