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        검색결과 22

        1.
        2024.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Mars is the planet closest to Earth. Many support that it may house humanity in the future. On the surface of Mars, sufficient resources are available to support life. Active studies are required to fundamentally comprehend the varied operating conditions and the major governing parameters involved in the growth of space colonization and supported atmospheric conditions. The existing legal framework of the Outer Space Treaty (OST), which was designed several decades ago, describes its goal of peaceful collaboration based on principles that we have not been able to uphold on Earth. It is vital to address the gaps in the legal system and ultimately deal with the mostly unanswered legal and regulatory questions. As interest in Martians colonisation missions from both government agencies and the private sector evolves, a workable solution that respects the essence of the OST and allows for limited sovereignty claims outside of protected habitation has been proposed.
        5,200원
        7.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Colors have been derived from the observed optical spectrum of Mars and Jupiter. It is known that the planets and the Moon emit re ected sunlight and thus their spectra are similar to the spectrum of solar radiation. The question was then why is the color of Mars different from that of other planets, i.e. red, although it would share the same spectrum of re ected sunlight. Can one derive color from the spectrum? Therefore, we observed the optical spectra of the scattered sunlight in day time for the Moon and Mars using a 1-D array spectrograph on the 12-inch reflecting telescope in the Korea Science Academy of KAIST in Busan, Korea. We adopted the International Commission on Illumination (CIE) in 1931 of three spectral sensitivity peaks for the human eye in short, medium and long wavelengths in visible light. The observed spectra were imposed on CIE sensitivities and the color detected by the human eye was derived. The Mars spectrum represents red color and the Moon white. It is a similar color to that which a human would see. This result means that color is easily derived from astronomical spectra. The appearance of the planets surface can be determined for Mars, which is the result of iron oxide.
        3,000원
        9.
        2015.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A three-dimensional computational fluid dynamics code is developed for predicting nonequilibrium flowfields over Mars entry probes. The numerical scheme is based on the cell-vertex finite volume method for a prismatic unstructured mesh system. Internal energy excitations and chemical reactions with finite rates are considered by introducing the two-temperature model of Park. Eight chemical species, C, N, O, CO, N2, NO, O2, and CO2, and nine chemical reactions are considered in the calculations. The developed code is verified in terms of prediction of heat flux to the body surface near the stagnation point of a Mars entry probe flying with the velocity of 6 km/s. The calculated heat flux reasonably agree with the calculated result in the past studies.
        4,000원
        11.
        2001.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We have constructed a non-spherical model for the hot oxygen corona of Mars by including the effects of planetary rotation and diurnal variation of the Martian ionosphere. Exospheric oxygen densities are calculated by integrating ensemble of ballistic and escaping oxygen atoms from the exobase over the entire planet. The hot oxygen atoms are produced by dissociative recombination of O+2, the major ion in the Martian ionosphere. The densities of hot oxygen atoms at the exobase are estimated from electron densities which have been measured to vary with solar zenith angle. Our model shows that the density difference of hot oxygen atoms between noon and terminator is about two orders of magnitude near the exobase, but reduces abruptly around altitudes of 2000 km due to lateral transport. The diurnal variation of hot oxygen densities remains significant up to the altitude of 10000 km. The diurnal variation of the hot oxygen corona should thus be considered when the upcoming Nozomi measurements are analyzed. The non-spherical model of the hot oxy-gen corona may contribute to building sophisticate solar wind interaction models and thus result in more accurate escaping rate of oxygens from Mars.
        4,000원
        12.
        2000.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We investigate the effects of planetary rotation on the exospheres of the earth and Mars with simple collisionless models. We develope a numerical code that computes exospheric densities by integrating velocity functions at the exobase with a 10 point Gauss method. It is assumed in the model that atoms above the exobase altitude move collisionlessly on an orbit under the planet's gravity. Temperatures and densities at the exobase over the globe are adopted from MSIS-86 for the earth and from Bougher et al's MTGCM for Mars. For both the earth and Mars, the rotation affects the exospheric density distribution significantly in two ways: (1) the variation of the exospheric density distribution is shifted toward the rotational direction with respect to the variation at the exobase, (2) the exospheric densities in general increase over the non-rotating case. We find that the rotational effects are more significant for lower thermospheric temperatures. Both the enhancement of densities and shift of the exospheric distribution due to rotation have not been considered in previous models of Martian exosphere. Our non-spherical distribution with the rotational effects should contribute to refining the hot oxygen corona models of Mars which so far assume simple geometry. Our model will also help in analyzing exospheric data to be measured by the upcoming Nozomi mission to Mars.
        4,000원
        13.
        1990.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the effects of variations in the kinetic structure on the science knowledge acquisition and analyzed the kinetic structure of a sience classroom communication. According to the rationale of the kinetic structure theory, a communication with high structure would facilitate greater knowledge acquisition than that with low structure. To testify that hypothesis, a modified non-equivalent pretest-posttest control group design was used. Four classes(8th grade), two classes for each sex, were selected. On the topic of 'Moon and Macs', two tape-recorded lessons differing in the kinetic structure were developed. Each lessons played 14 minutes long. One of them was high structure(B ̄₁ = 0.48) and the other was low structure(B ̄₁ = 0.19). The results showed that the students with high structure lesson achieved greater than those with low structure lesson(F = 7.03, p $lt; .01). But when the results were analyzed by sex, only boy students' achievement showed a significant difference between low and high structure groups(F = 9.54, p $lt;.01). The results of this study suggest that a high structure communication will facilitate the science learning in the case of boy students. On the other hand, an actual classroom communication on the topic of `Moon and planets' was tape-recorded from a middle school science class(9th grade) and lasted 45 minutes long. It was analyzed by Anderson's and Kim's methods of the kinetic structure analysis. The grand mean fundamental coefficient of the whole communication was 0.20, and the grand mean weighted coefficient was 0.84. This communication showed high mean progression density(D ̄s= 0.88 with (NAC) ̄=1.14). Thus, in general, this verbal communication had low structure and high progression. Therefore, it can be concluded that this classroom communication will give the students some difficulties in their learning.
        4,000원
        14.
        2022.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        By providing an environment where energetic particles and micrometeorites can not penetrate, caves on Mars may serve as a human shelter in future Mars explorations. More than 1,000 cave entrance candidates have been detected; however, their physical characteristics that can be utilized in detecting more candidates have not been explored in detail. In this paper, we explore the nighttime temperature of 100 cave entrance candidates and their surrounding areas to investigate 1) the nighttime temperature tendencies relative to their surrounding areas and 2) the extent of these temperature differences. We find that 79% of the cave entrance candidates exhibit higher temperatures than the surrounding areas, and 59% show a temperature difference over 20K, suggesting that the cave entrances may generally show higher temperatures than the surrounding areas during the nighttime.
        16.
        2012.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        It is a crucial matter to select a landing site for landers or rovers in planning the Mars exploration. The landing site must have not only a scientific value as a landing site, but also geographical features to lead a safe landing for Mars probes. In this regard, this study analyzed landing site of Mars probes and rovers in previous studies and discussed the adequacy of the landing site to scientific missions. Moreover, this study also examined domestic studies on the Mars. The frameworks of these studies will guide the selection of exploration sites and a landing site when sending Mars probe to the Mars through our own efforts. Additionally, this paper will be used as the preliminary data for selection of exploration site and a landing site.
        17.
        2012.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        In this study, the transient second or third layer on the topside of the Martian ionosphere were investigated with the most recently released Mars advanced radar for subsurface and ionospheric sounding/Mars Express data obtained from January 2010 to September 2011 to study the correlation between these topside additional layers and surface magnetic fields, solar zenith angle and solar activities. When examining the zones where the topside layer appeared, the occurrence rate of the topside layer was low at the areas with a strong Martian crustal magnetic field as observed by the Mars global surveyor. The occurrence rate of additional layers on the Martian topside ionosphere decreases as the solar zenith angle increases. However, these layers appeared significantly near the terminator of which solar zenith angle is 90°. In comparison between F10.7 which is the index of solar activities and the occurrence rate of the topside layer by date, its occurrence rate was higher in 2011 than in 2010 with less solar activities. The result of this study will contribute to better understanding of the environments in the topside of the ionosphere through the correlation between the various conditions regarding the Martian ionosphere and the transient layer.
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