• Title/Summary/Keyword: eclipse

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Photometric Orbital Analysis of an Eclipsing Binary System, RZ Draconis

  • Chou, Kyong-Chol
    • Journal of The Korean Astronomical Society
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    • v.2 no.1
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    • pp.10-22
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    • 1969
  • Two-Color photoelectric observations were made at Flower and Cook Observatory, University of Pennsylvania. Since the spectroscopic elements are available for the system, derivation of an absolute physical dimension is now expected to be feasible. Results of computation of the orbital elements lead to a fact that the system shows an annular eclipse rather than a partial which is a finding reported by Shapley.

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MEANING OF 'EXHAUSTED ECLIPSES' IN ANCIENT EPHEMERIDES (고대 역법에 나오는 일식기(日食旣)의 의미)

  • Ahn, Sang-Hyeon
    • Publications of The Korean Astronomical Society
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    • v.23 no.2
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    • pp.65-71
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    • 2008
  • It has been considered that 'exhausted eclipses' (日食旣) were total eclipses. However, modern precise calculations show that a significant fraction of such records are not realized to be total. Thus we doubt that the two concepts are equivalent. Here we investigate the meaning of 'exhausted eclipses' in the east-Asian history. We first find that eclipses of magnitude greater than 0.8 were regarded as 'exhausted eclipses' by a Korean astronomer of the 18th-century Choson dynasty. His notion was based upon the definition of 'exhausted eclipses' in the ephemerides of pre-modern Chinese dynasties. According to those ephemerides, the 'exhausted eclipses', whose magnitude is greater than 0.8, have the first contact at the western part of the solar disk and the fourth contact at the eastern part of the solar disk. A simple geometrical calculation shows that such cases really occur when the magnitude of eclipse is greater than 0.7. We pointed out that such an ancient definition might not be impractical for ancient astronomers, because the uncertainty of eclipse magnitude estimated by ancient Chinese ephemerides was 10% and the human sight has a spatial resolution of 1.2 arcmin, which is approximately one twentieth of the Sun's angular diameter.

Java based Platform for Educational Robots on AVR (교육용 AVR 로봇의 자바기반 플랫폼)

  • Lee, Lee-Sub;Kim, Seong-Hoon
    • Journal of Intelligence and Information Systems
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    • v.15 no.3
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    • pp.17-29
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    • 2009
  • C programming is a main programming for the Educational Robot Arm which is based on AVR ATmega128. The development environment is not integrated, so it is complex and difficult to study for middle or high school students who want to learn programming and control the educational robot arm. Furthermore, there is no debug and testing environment support. This paper presents a Java-based development platform for the educational robot arm. This platform includes: an up-to-date tiny Java Virtual Machine (NanoVM) for the educational robot arm; An Eclipse based Java integrated development environment as an Eclipse plug-in; a 3D simulator on the PCs to support testing and debugging programs without real robots. The Java programming environment makes development for educational robot arm easier for students.

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Sonication Effect on the Relative Permeability of contaminated Soil (초음파에 의한 오염토의 상대투수계수의 변화)

  • 김영욱
    • Journal of Soil and Groundwater Environment
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    • v.6 no.1
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    • pp.45-52
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    • 2001
  • This study investigated the effectiveness of ultrasonic waves on the relative permeability under a range of soil type, flushing rate, and sonication power. This study was conducted in the laboratory using a specially designed and fabricated equipment, and the laboratory study was simulated by ECLPISE 100 which is a commercial black oil simulator. The test results indicated the sonication increased contaminant extraction significantly. From analytical standpoint, sonication caused a change in the relative permeability of the test samples, a reduction in residual oil saturation and an increase in both irreducible water saturation and wettability. These three parameters are highly related with $(C_{10})^2$. The computer software ECLIPSE 100 can be used to analyze the change of the relative permeability due to sonication in two phase immiscible flow.

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Development of DIagnostic Coronagraph Experiment (DICE) for Total Solar Eclipse

  • Choi, Seonghwan;Kim, Jihun;Park, Jongyeob;Jang, Biho;Bong, Suchan;Cho, Kyung-Suk
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.2
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    • pp.66.3-66.3
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    • 2017
  • Korea Astronomy and Space Science Institute (KASI) is developing a coronagraph in collaboration with National Aeronautics and Space Administration (NASA) which will be installed on the International Space Station (ISS). The coronagraph can measure speed and temperature by using four filters approximately 400 nm and polarization filter in three different angles, differently with older coronagraphs. For the successful mission, it has development and experiment progress in three phases; total solar eclipse experiment in 2017, balloon experiment in 2019, and the ISS installation in 2021. As a first experiment, we developed a coronagraph without an occulter named with Diagnostic Coronagraph Experiment (DICE) for experiment for filter system and imaging sensor. We designed optics with a field of view from 2.5 to 15 solar radii. It has four filters approximately 400 nm and polarizer to measure speed and velocity of the solar corona. For the selection of filter or polarization angle, it has two mechanism parts; filter wheel assembly and a polarizer wheel assembly. Especially we used Core Flight System (CFS) platform which was developed by NASA, when we develop the coronagraph operation software. It provides us stability, reusability, and compatibility.

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2017 Total Solar Eclipse Expedition of KASI

  • Bong, Su-Chan;Choi, Seonghwan;Kim, Jihun;Park, Jongyeob;Jang, Bi-Ho;Park, Young-Deuk;Cho, Kyung-Suk;Cho, Kyuhyoun;Chae, Jongchul
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.2
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    • pp.67.2-67.2
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    • 2017
  • Korea Astronomy and Space Science Institute (KASI) plans to develop a coronagraph to measure the coronal electron density, temperature, and speed using four different filters around 400 nm, where strong Fraunhofer lines from the photosphere are scattered by coronal electrons. During the total solar eclipse occurring on August 21 across USA, KASI will organize an expedition team to demonstrate the coronagraph measurement scheme and the instrumental technology. The observation site is in Jackson Hole, Wyoming, USA. We plan to build two coronagraphs without occulter to improve signal to noise ratio. In addition, images of white light corona, wide field background, and all sky are planned to be taken with DSLR cameras. We will present the preliminary results of the expedition.

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The Implementation of Embedded Web Server System for a Remote Control and Measurement (원격 제어 및 계측을 위한 임베디드 웹 서버 시스템 구현)

  • Lee, Myung-Eui
    • Journal of Advanced Navigation Technology
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    • v.16 no.5
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    • pp.839-845
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    • 2012
  • This paper deals with the design and development of the remote control and measurement systems by Embedded Web Server. The remote control and measurement systems are implemented by Cortex M-3 ARM micro-controller. The user application software for the control and measurement system user, and the firmware software of device drivers for peripherals such as a digital input/output device, AD/DAC(Analog to Digital/Digital to Analog Converter), LCD, and temperature/humidity sensor are developed in Eclipse environment using Codesourcery C, Java script, and HTML. The experimental result of the proposed control and measurement systems implemented in this paper is evaluated via real-time experiments, which works well as designed.

Android mobile phone information push system based on the XMPP protocol (XMPP 프로토콜기반 Android 휴대폰 정보 푸쉬 시스템)

  • Liu, Hao;Liu, Jie;Choi, Kwang-Il;Park, Sang-No;Jung, Hoe-Kyung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2012.10a
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    • pp.646-648
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    • 2012
  • In this paper, android phone information push system based on the XMPP protocol is proposed. It uses Java and eclipse development tools to create an information pushing system in android phone based on the XMPP protocol, and runs on the C/S network situation. Not only, the information can be send and receire form android phone in the PC server, but also the smack packet of the android phone is used fully by this system. Therefore, the speed of the transmission and the transfer are better than other sending sportocol in the basic XMPP protocol of the system.

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Android mobile phone information push system based on the XMPP protocol (XMPP 프로토콜기반 안드로이드 휴대폰 정보 푸쉬 시스템)

  • Pyoun, Do-Kil;Hao, Liu;Jung, Hoe-Kyung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.3
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    • pp.561-566
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    • 2013
  • In this paper, android phone information push system based on the XMPP protocol is proposed. For this, we implement a XMPP(eXtensible Message and Presence Protocol) based instant message system in C/S network environment by using Java language and eclipse device. This system not only allows sending and receiving messages from the PC server to mobile phone client, but also enables the expansion into the smack package of an android phone. Thus, this system shown, in this paper has the better performance in transmission and transfer speed than those of the basic XMPP protocol system.