• Title/Summary/Keyword: Lunar cycle

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DATING ISSUE OF THE NATIONAL FOUNDATION DAY OF KOREA (개천절 일자(日字)와 단군조선 개국년도 문제 고찰과 제언)

  • Park, Changbom
    • Publications of The Korean Astronomical Society
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    • v.30 no.1
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    • pp.1-9
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    • 2015
  • The National Foundation Day of Korea (개천절, 開天節) is currently celebrated on October 3 in Gregorian calendar. We review the history of dating the National Foundation Day of Korea and make a suggestion that it be celebrated on October 3 in the lunar calendar. We present numerous historical records on heaven-worship rites supporting the date October 3 in the lunar calendar. It is pointed out that October 3 in the solar calendar has been adopted in 1949 by the National Assembly with the thought that the lunar calendar is inferior and behind the times. The thought originates from misunderstanding on the value of the lunar calendar and from the ignorance of importance of history and tradition. Since there are now many national holidays that follow the lunar calendar, the logic of the National Assembly in 1949 also makes no sense. We emphasize that the lunar calendar should be followed for the National Foundation Day of Korea for its historical and symbolic characteristics restoration. We also investigate the year of the foundation of the first country of Korea, Dangun Joseon. It is found that even though the majority of the literature before late 15th century recorded the beginning year of Dangun Joseon dynasty to be equal to that of Liao Dynasty (堯), it was accidentally changed to the 25th year of Liao Dynasty in 1484 through a misinterpretation of the previous records. We claim that the beginning year of Dangun Joseon should be set to that of Liao Dynasty as recorded in the original literature in the earlier days. According to the two main opinions accepted by Korea, the beginning year of Liao Dynasty was 2357 B.C. or 2333 B.C., which correspond to the year of Gap-Jin (the 41st year of the sexagenary cycle) or Mu-Jin (the 4th year of the sexagenary cycle), respectively.

Reproductive Cycle and Spawning Rhythm of the Ascidian, Halocynthia hilgendorfi ritteri

  • Choi, Young-Jin;Lee, Chi-Hoon;Rho, Sum;Lee, Young-Don
    • Animal cells and systems
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    • v.8 no.1
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    • pp.33-40
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    • 2004
  • Reproductive cycle and spawning rhythm with lunar cycle of the ascidian, Halocynthia hilgendorfi ritteri were investigated by histological examination. The specimens were sampled in the coastal waters of Yongdam, northwest of Jeju Island, Korea, from November 2001 to January 2003. H. hilgendorfi ritteri is a synchronous hermaphrodite; the gonads are located in the mantle. The reproductive cycle can be grouped into the following successive stages in the ovary: growth (February to June), vitellogenesis (April to September), mature (July to December), spent (November to February), and recovery (December to April). Likewise, in the testis, the stages observed were: growth (October), mature (October to December), spent (November to February), and resting (January to September). Major spawning probably occurs between November and January, when water temperatures decrease. The histological observations of the gonads suggested that this species is a multiple spawner during the spawning period. Spawning occurred between the new moon and full moon, and again between the full moon and new moon, suggesting that the spawning rhythm is influenced by the lunar cycle.

Conceptual Design of Korea Aerospace Research Institute Lunar Explorer Dynamic Simulator

  • Rew, Dong-Young;Ju, Gwang-Hyeok;Kang, Sang-Wook;Lee, Sang-Ryool
    • Journal of Astronomy and Space Sciences
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    • v.27 no.4
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    • pp.377-382
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    • 2010
  • In lunar explorer development program, computer simulator is necessary to provide virtual environments that vehicle confronts in lunar transfer, orbit, and landing missions, and to analyze dynamic behavior of the spacecraft under these environments. Objective of simulation differs depending on its application in spacecraft development cycle. Scope of use cases considered in this paper includes simulation of software based, processor and/or hardware in the loop, and support of ground-based flight test of developed vehicle. These use cases represent early phase in development cycle but reusability of modeling results in the next design phase is considered in defining requirements. A simulator architecture in which simulator platform is located in the middle and modules for modeling, analyzing, and three dimensional visualizing are connected to that platform is suggested. Baseline concepts and requirements for simulator development are described. Result of trade study for selecting simulation platform and approaches of defining other simulator components are summarized. Finally, characters of lunar elevation map data which is necessary for lunar terrain generation is described.

Reproductive Cycle of Top Shell, Trochus niloticus in Chuuk Island, Micronesia (Micronesia Chuuk Island에 서식하는 Top shell, Trochus niloticus의 생식주기)

  • Jin, Young-Seok;Park, Yong-Ju;Kim, Han-Jun;Na, Oh-Soo;Song, Young-Bo;Lee, Chi-Hoon;Choi, Myun-Sik;Rho, Sum;Lee, Young-Don
    • The Korean Journal of Malacology
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    • v.20 no.1
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    • pp.65-73
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    • 2004
  • Gametogenesis, changes of gonad bulk index (GBI), monthly variation in oocyte diameter, reproductive cycle and spawning with lunar cycle of the top shell, Trochus niloticus were investigated by histological examination. The specimens were sampled in the coastal waters of Chuuk Island, Micronesia, form November 1999 to September 2000. T. niloticus is a gonochorism, and the female and male were present in an approximately 1:1 ratio (p > 0.05). The ovary contained with the oocyte of yolk stage, the testis composed of the spermatid and spermatozoa at around the year. Monthly GBI were higher at February, March, April and June than the other months. Major spawning occurred between April and May, and June and July but the individuals of partially spawning were presented throughout the year. GBI with lunar cycle were higher at the full moon than the other lunar phase. These results suggest that the spawning occurred between the full moon and last quarter moon.

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A Study on the Use of the Lunar Principle of MULDAE as a Predictor of Tidal Phenomenon (물때의 실용화에 관한 연구)

  • 박청정
    • Journal of the Korean Institute of Navigation
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    • v.9 no.1
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    • pp.41-81
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    • 1985
  • Tidal phenomenon can be utilized by the wise and cautious mariner to safely perform his duties as pilot and navigator. It can be either a help or hindrance to the mariner. The principle of MULDAE which expresses the determination of the state of the tide based upon knowledge of the lunar date and it has been used in Korea since ancient times. The folk method of calculation was essentially based on an unsystematic division of the lunar month, traditionally using the numbers 7 or 8. As the lunar cycle is complete in 15 days the tidal cycle should also correspondence closely to the lunar date. This paper represents the first scientific attempt to systematically investigate this unique traditional method of tidal calculation and contains a comparison of the MULDAE and ordinary (solar based) tide calculation methods. MULDAE was compared with the standard tide table for standard and island ports in Korea from 1982 to 1985. This study concluded that MULDAE was indeed an accurate adn reliable predictor of tidal activity. Furthermore, the number 6 was found to be the correct divisor upon which to base MULDAE calculations Also a formula expressing MULDAE as a function was discovered. This research show that MULDAE can be applied nationwide and is a reliable and easy way to predict tides based upon mean figures for certain ports and island A calender showing MULDAE is presented here for the first time. A clear relationship between the MULDAE method of calculating tides and the use of ordinary tide tables is proven.

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A Study on the correlation between Drinking and MMPI in lunar cycle (달의 주기(週期)에 따른 음주(飮酒)와 인성(人性)과의 연관성(聯關性)에 관(關)한 조사연구(調査硏究))

  • Lee Seok-Jun;Ryu Yeong-Su;Ryu Hui-Yeong
    • Journal of Oriental Neuropsychiatry
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    • v.4 no.1
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    • pp.155-164
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    • 1993
  • In this study the author had attempted to establish a correlation among alcohol use and MMPI and lunar cycle. MMPI was carried on 2, April 1992(the last day of the second lunar month) and 15, June 1992(the fifteenth day of the fifth lunar month). These experiments took male and female students who were in WON KWANG University as subjects. The results of it suggested the followings. 1) Drinkers and normal subjects average of T-score in each scales were in a normal scores. 2) In every scales except L,K,Si scales drinkers showed higher scores than normal subjects. There was a significant difference on L, F, Pd, Pa, Sc, Ma scales. 3) On the fifteenth day of the month, drinkers showed Higher T-Scores than normal subjects in every scales excepts L,K,Si scales. There was a significant difference in Ma scale. 4) On the last day of the month, drinkers showed higher T-scores than normal subjects in every scales except L,K,Mf,Si scales. There was a significant difference on L, F, Pd, Sc, Ma scales. 5) Drinkers showed higher than normal subjects in symptom of neurosis and psychosis. As the results of above, human character changes to some extend according to alcohol use. There is a tendency that repeated drinking of college students prone to change into habitual drinking or alcoholic impairment. So controlled drinking among the college students is highly recommended.

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Heat Flux Analysis of Lunar Lander for Potential Landing Candidate Area (달 착륙선의 착륙 후보지별 열 유입량 분석)

  • Park, Tae-Yong;Chae, Bong-Geon;Lee, Jang-Joon;Kim, Jung-Hoon;Oh, Hyun-Ung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.4
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    • pp.324-331
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    • 2018
  • The thermal environment on lunar surface is more severe than that of earth's surface or low earth orbit because of the long daytime and nighttime due to 28 days of rotation cycle of moon. Thus, analyzing heat flux on lunar lander at potential landing sites is important to determine the landing site in its initial design phase. In this study, thermal model of lunar regolith that can simulate lunar surface temperature was constructed for analyzing thermal characteristics according to the potential landing sites of lunar lander. The heat flux analyses were performed various latitudes of equator, mid-latitude, polar regions, lunar mare and highland. In addition, we also investigated the heat flux of lunar lander when it is landed on adjacent area to hill.

The Effect of Solar Burst in Communications System for Lunar Exploration (달 탐사 통신 시스템에서 태양 폭발의 영향)

  • Kim, Sanggoo;Hong, Heejin;Oh, Janghoon;Yoon, Dongweon;Hyun, Kwangmin
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.2
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    • pp.309-316
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    • 2013
  • Since the solar activity, one of the factors influencing on lunar communication systems, is to reach its maximum occurring at 11-year solar cycle in autumn 2013, the solar burst frequency and strength are expected to increase. The solar burst has an effect on earth magnetosphere and causes malfunction, loss of communication, and breakdown of various types of satellites and probes. These problems give rise to huge economic and physical loss. Therefore, we should analyze the effect of solar burst on lunar communications and minimize the expected loss. In this paper, we perform the analysis of the link model and link performance between a land station and a lunar orbiter under the solar burst for orbiter's survivability and stable communication channel operations.

A Study on the correlation between the lunar cycle and M. M. P. I (우주변화(宇宙變化)와 인성(人性)과의 관련성(關連性)에 관한 조사연구(調査硏究))

  • Lee Seok-Jun;Yu Yeong-Su
    • Journal of Oriental Neuropsychiatry
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    • v.3 no.2
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    • pp.87-96
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    • 1992
  • In order to see the variation of human nature, M.M.P.I. was carried on 2, April 1992 (the last day of the second lunar month) and 15, June 1992 (the fifteenth day of the fifth lunar month). These experiments took male and female students who were in Won kwang University as subjects (108 students on 2, April, 105 students on 15, June). The results of it suggested the followings. 1) Every students' average of T-grades on each measure were in a normal scope. 2) There were no significant differences in comparison between the fifteenth day and the last day of the month. 3) On every measure except L, Mf, Si, the female students showed higher grade in the fifteenth day than the last day of the month. But there was no significant difference in male students. Both male and female students didn't show the significant one. 4) On the fifteenth day of the month, the female students showed higher T-grade then male did on every measure except Mf, Ma, Si. There was a significant difference on D, Pd, Mf(P<0.05) measure. 5) On the last day of the month, male students showed higher T-grade then female did on every measure except L, K, Hy, Pt. There was a significant difference on L(P<0.001), K(P<0.01). 6) On experiments about female students, there was no symptom of neurosis and psychosis on the last day of the month. But three of sixteen students(18.7%) showed symptom of neurosis, one of thirteen(6%) showed symptom of psychosis on the fifteenth day of the month. On experiments about male students, eleven of ninety-two(11.9%), four of ninety-two(4.3%) showed symptom of neurosis and psychosis respectively on the fifteenth day of the month. Ten of ninety-two(10.8%), six of ninety-two(6.5%) showed symptom of neurosis and psychosis respectively on the last day of the month. As the results of the above, human nature changes to some extend according to lunar cycle. And there are many changes in female than male. But it is difficult to generalize this fact by limited subject and only one experiments. So the controlled studies are needed on the basis of this result and have to take many person as a subject.

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Study on Net Assessment of Trustworthy Evidence in Teleoperation System for Interplanetary Transportation

  • Wen, Jinjie;Zhao, Zhengxu;Zhong, Qian
    • Journal of Information Processing Systems
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    • v.15 no.6
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    • pp.1472-1488
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    • 2019
  • Critical elements in the China's Lunar Exploration reside in that the lunar rover travels over the surrounding undetermined environment and it conducts scientific exploration under the ground control via teleoperation system. Such an interplanetary transportation mission teleoperation system belongs to the ground application system in deep space mission, which performs terrain reconstruction, visual positioning, path planning, and rover motion control by receiving telemetry data. It plays a vital role in the whole lunar exploration operation and its so-called trustworthy evidence must be assessed before and during its implementation. Taking ISO standards and China's national military standards as trustworthy evidence source, the net assessment model and net assessment method of teleoperation system are established in this paper. The multi-dimensional net assessment model covering the life cycle of software is defined by extracting the trustworthy evidences from trustworthy evidence source. The qualitative decisions are converted to quantitative weights through the net assessment method (NAM) combined with fuzzy analytic hierarchy process (FAHP) and entropy weight method (EWM) to determine the weight of the evidence elements in the net assessment model. The paper employs the teleoperation system for interplanetary transportation as a case study. The experimental result drawn shows the validity and rationality of net assessment model and method. In the final part of this paper, the untrustworthy elements of the teleoperation system are discovered and an improvement scheme is established upon the "net result". The work completed in this paper has been applied in the development of the teleoperation system of China's Chang'e-3 (CE-3) "Jade Rabbit-1" and Chang'e-4 (CE-4) "Jade Rabbit-2" rover successfully. Besides, it will be implemented in China's Chang'e-5 (CE-5) mission in 2019. What's more, it will be promoted in the Mars exploration mission in 2020. Therefore it is valuable to the development process improvement of aerospace information system.