• Title/Summary/Keyword: High-event

Search Result 1,629, Processing Time 0.039 seconds

Supernova Rates of the Milky Way and the Local Group

  • Koo, Bon-Chul
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.42 no.1
    • /
    • pp.36.1-36.1
    • /
    • 2017
  • A major goal of the proposed Korean Neutrino Detector and Telescope is to detect neutrino burst from core-collapse supernova (SN) explosions in the Milky Way, which will provide an unprecedented opportunity to look into the core of an exploding massive star. Detection with high statistics would give important information for the explosion physics. It can also detect neutrino signals from SN events in the Local Group and trigger alert of the event for the astronomical community. In this talk, I will review the SN rates of the Milky Way and the Local Group, and will discuss the implications for the proposed neutrino telescope.

  • PDF

항공기 연료탱크 폭발방지를 위한 방안 연구

  • Kim, Seung-Kyem
    • Aerospace Engineering and Technology
    • /
    • v.3 no.1
    • /
    • pp.272-276
    • /
    • 2004
  • Fuel tank design requires special care because tank explosion can cause critical event with high possibility and cause of recent explosion accidents haven't been found out definitely. In this study, cause of fuel tank explosion was reviewed and several design considerations to minimize explosion possibility were introduced.

  • PDF

Global MHD Simulation of the Earth's Magnetosphere Event on October, 1999

  • PARK KYUNG SUN;OGINO TATSUKI
    • Journal of The Korean Astronomical Society
    • /
    • v.34 no.4
    • /
    • pp.317-319
    • /
    • 2001
  • The response of the earth's magnetosphere to the variation of the solar wind parameters and Interplanetary magnetic field (IMF) has been stud}ed by using a high-resolution, three-dimension magnetohydrodynamic (MHD) simulation when the WIND data of velocity Vx, plasma density, dynamic pressure, By and Bz every 1 minute were used as input. Large electrojet and magnetic storm which occurred on October 21 and 22 are reproduced in the simulation (fig. 1). We have studied the energy transfer and tail reconnect ion in association with geomagnetic storms.

  • PDF

Research about optimal installation of ATP system in High speed Rolling-stock (고속차량 ATP시스템 개량의 최적화에 관한 연구)

  • Ryu, Byung-Gwan
    • Proceedings of the KSR Conference
    • /
    • 2009.05a
    • /
    • pp.476-482
    • /
    • 2009
  • A signal equipment improvement project for the existing facility ATS to ATP is under construction in Kyung-Bu and Ho-Nam commercial line including 400 rolling stocks. But there was a concern for the interface between KTX OBCS and ATP from the beginning of the project. At present, this is the front burner event. This paper introduces interface checking and predicted failure point between KTX OBCS and ATP improvement system. Through this measure the optimal installation of the ATP will be possible. The study was made under maintenance efficiency including reliability because the KTX signal equipment must qualify the above condition.

  • PDF

Investigation on Characteristics of High PM2.5 Pollution Occurred during October 2015 in Gwangju (광주 지역에서 2015년 10월에 발생한 PM2.5 고농도 사례 특성 분석)

  • Yu, Geun-Hye;Park, Seung-Shik;Jung, Sun A;Jo, Mi Ra;Lim, Yong Jae;Shin, Hye Jung;Lee, Sang Bo;Ghim, Young Sung
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.34 no.4
    • /
    • pp.567-587
    • /
    • 2018
  • A severe haze event occurred in October 2015 in Gwangju, Korea. In this study, the driving chemical species and the formation mechanisms of $PM_{2.5}$ pollution were investigated to better understand the haze event. Hourly concentrations of $PM_{2.5}$, organic and elemental carbon, water-soluble ions, and elemental constituents were measured at the air quality intensive monitoring station in Gwangju. The haze event occurred was attributed to a significant contribution (72.3%) of secondary inorganic species concentration to the $PM_{2.5}$, along with the contribution of organic aerosols that were strongly attributed to traffic emissions over the study site. MODIS images, weather charts, and air mass backward trajectories supported the significant impact of long-range transportation (LTP) of aerosol particles from northeastern China on haze formation over Gwangju in October 2015. The driving factor for the haze formation was stagnant atmospheric flows around the Korean peninsula, and high relative humidity (RH) promoted the haze formation at the site. Under the high RH conditions, $SO{_4}^{2-}$ and $NO_3{^-}$ were mainly produced through the heterogenous aqueous-phase reactions of $SO_2$ and $NO_2$, respectively. Moreover, hourly $O_3$ concentration during the study period was highly elevated, with hourly peaks ranging from 79 to 95ppb, suggesting that photochemical reaction was a possible formation process of secondary aerosols. Over the $PM_{2.5}$ pollution, behavior and formation of secondary ionic species varied with the difference in the impact of LTP. Prior to October 19 when the influence of LTP was low, increasing rate in $NO_3{^-}$ was greater than that in $NO_2$, but both $SO_2$ and $SO{_4}^{2-}$ had similar increasing rates. While, after October 20 when the impact of haze by LTP was significant, $SO{_4}^{2-}$ and $NO_3{^-}$ concentrations increased significantly more than their gaseous precursors, but with greater increasing rate of $NO_3{^-}$. These results suggest the enhanced secondary transformation of $SO_2$ and $NO_2$ during the haze event. Overall, the result from the study suggests that control of anthropogenic combustion sources including vehicle emissions is needed to reduce the high levels of nitrogen oxide and $NO_3{^-}$ and the high $PM_{2.5}$ pollution occurred over fall season in Gwangju.

Design and Verification Method for the Train Supervisory Controller of the Korean High-Speed Tarin (한국형 고속전철의 열차 관리제어기의 설계 및 검증 방법)

  • Yoo, Seung-Pil;Lee, Doo-Yong
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.7 no.1
    • /
    • pp.1218-1225
    • /
    • 2001
  • This paper presents a design procedure for the supervisory controller(SC) of the high-speed train car. The proposed SC manages control logic and scenario of the overall train system, and monitors input/output signals among the sub-controllers in the system, The roles and functions of each sub-control system are defined, and the interfaces among the control systems are developed. Train control system is modeled with automata, and the model is implemented into a program using a computer-aided software engineering(CASE) tool, Object GEODE, The designed SC is verified and evaluated by using simulation. The SC is shown to successfully perform the designed functions without any errors.

  • PDF

Design of Asynchronous Library and Implementation of Interface for Heterogeneous System

  • Jung, Hwi-Sung;Lee, Joon-Il;Lee, Moon-Key
    • Proceedings of the IEEK Conference
    • /
    • 2000.06b
    • /
    • pp.221-225
    • /
    • 2000
  • We designed asynchronous event logic library with 0.25$\mu\textrm{m}$ CMOS technology and interface chip for heterogeneous system with high-speed asynchronous FIFO operating at 1.6㎓. Optimized asynchronous standard cell layouts and Verilog models are designed for top-down design methodology. A method for mitigating a design bottleneck when it comes to tolerate clock skew is described. This communication scheme using clock control circuits, which is used for the free of synchronization failures, is analyzed and implemented. With clock control circuit and FIFO, high-speed communication between synchronous modules operating at different clock frequencies or with asynchronous modules is performed. The core size of implemented high-speed 32bit-interface chip for heterogeneous system is about 1.1mm ${\times}$ 1.1mm.

  • PDF

Investigation of Thermal Stress of Continuous Welded Rail on High Speed Railway Bridge (경부고속철도 교량상 장대레일의 온도응력 계측 실험)

  • Kang, Jae-Yoon;Choi, Eun-Suk;Chin, Won-Jong;Lee, Jung-Woo;Kwark, Jong-Won;Kim, Byung-Suk
    • Proceedings of the KSR Conference
    • /
    • 2007.11a
    • /
    • pp.458-461
    • /
    • 2007
  • Recently, the continuous welded rail(CWR) track has been used for less maintenance of the High-speed railway tracks. In case of CWR track, track buckling has always been an unpredictable event under the high compressive stress in rail. The behavior and stress state of CWR track is manily influenced by its thermal variations, and it is important to understand seasonal variations of rail temperature and stress to predict the track stability. This paper describes the in-site measurement for the rail temperature and rail stress, and the correlation between the rail temperature and stress was examined.

  • PDF

A Study on Fire Profection and Egress Countermeasure of the High Buildings in the Large City (대도시 고층건물의 방재 및 피난대책에 관한 연구)

  • 김동준
    • Journal of the Korean Society of Safety
    • /
    • v.5 no.1
    • /
    • pp.77-81
    • /
    • 1990
  • In the event of fire, the tendency of over­buildings and high­building resulted from the concentration in population in cities causes great losses of human lives and property. Man is able to prevent fire itself from taking place on his own efforts. One of fire preventions at high­buildings is to Survey the environmental situations around the constructions from the beginning, and when the construction is going on, it is indispensable to install appropriate water­proof dampers with all sorts of equipments. Hence, lots of the owner's investment of the buildings in fire prevention facilities is necessary and, so is constructions in agreement with every regulations.

  • PDF

Analyses of alternative polyadenylation: from old school biochemistry to high-throughput technologies

  • Yeh, Hsin-Sung;Zhang, Wei;Yong, Jeongsik
    • BMB Reports
    • /
    • v.50 no.4
    • /
    • pp.201-207
    • /
    • 2017
  • Alternations in usage of polyadenylation sites during transcription termination yield transcript isoforms from a gene. Recent findings of transcriptome-wide alternative polyadenylation (APA) as a molecular response to changes in biology position APA not only as a molecular event of early transcriptional termination but also as a cellular regulatory step affecting various biological pathways. With the development of high-throughput profiling technologies at a single nucleotide level and their applications targeted to the 3'-end of mRNAs, dynamics in the landscape of mRNA 3'-end is measureable at a global scale. In this review, methods and technologies that have been adopted to study APA events are discussed. In addition, various bioinformatics algorithms for APA isoform analysis using publicly available RNA-seq datasets are introduced.