• 천문학회보
• /
• 제36권2호
• /
• pp.70.1-70.1
• /
• 2011

We have investigated properties of merging galaxies in the nearby universe, using Sloan Digital Sky Survey (SDSS) DR7. We first constructed two galaxy samples according to redshift range: Sample 1 for 0 ${\leq}$ z ${\leq}$ 0.025 and Sample 2 for 0.09 ${\leq}$ z ${\leq}$ 0.1. We then identified 118 and 184 merging galaxies among the galaxies in the Sample 1 and 2, respectively, and classified them into different merging types and stages by visual inspection of galaxy images. In the Sample 1, there are more wet mergers than dry mergers, while most merging galaxies in the Sample 2 are dry mergers. The color-magnitude diagram of the merging galaxies in our samples is comparable to that of normal galaxies. Dry mergers tend to locate in the red sequence, while wet and mixed mergers reside mostly in the blue cloud. Unlike some previous studies, we did not find a clear trend that the merger rate increases at higher redshift. However, it is difficult to make a direct comparison of the merger rate found in different studies, because it depends on the number of observed galaxies and criteria for merger classification. From the ratios of emission lines, we infer that the faction of merging galaxies with AGNs is higher in wet mergers than in other types.

• 천문학회보
• /
• 제44권1호
• /
• pp.83.1-83.1
• /
• 2019

Identifying asteroid families, which are groups of asteroids with similar orbital properties, is important for understanding the formation and evolution of the solar system, and probing the origins of Near-Earth Objects (NEOs). Although asteroid taxonomy can be used to identify and refine asteroid families, there are numerous asteroids which are not taxonomically classified yet. Korea Microlensing Telescope Network (KMTNet) can be useful to investigate types of that asteroids, because the telescope can observe a number of asteroids at once by its large field of view. Using KMTNet data, we confirmed that the taxonomic classification of the asteroids is possible by plotting color-color diagram. There is a clear division between C-type and S-type, but ambiguous division between C-type and X-type. In the future, we will observe and classify asteroids which are not classified yet and utilize the data to identify and refine asteroid families.

• 한국지구과학회지
• /
• 제30권3호
• /
• pp.317-329
• /
• 2009

본 연구는 신학 전공 대학생들과 과학 교육 전공 대학생들과의 비교를 통하여 신학 전공 대학생들의 우주와 생명의 기원에 관련된 관점과 과학에 대한 인식을 알아보며, 신학 전공 대학생들을 대상으로 개설한 현대 과학의 이해와 관련된 과목을 한 학기 수강한 이후에 일어나는 관점의 변화를 살펴보는 것이다. 이를 위해 신학 전공 대학생 26명과 과학교육 전공 대학생 19명이 설문에 참여하였다. 신학 전공 대학생들의 경우, 수강 전 젊은 지구 창조론과 오랜 지구 창조론을 합하여 42%, 유신론적 진화론을 지지하는 응답자는 42%로 나타났으며 생물학적 진화론을 지지하는 응답자는 단 한 명도 없었다. 이에 반해, 과학교육을 전공하는 대학생들 대부분의 진화론을 지지하고 있었으며 극단적인 입장의 창조론을 지지하는 응답자는 없는 것으로 드러났다. 또한 창조론을 지지하는 대부분의 응답자는 과학이 창조주의 업적을 기술하는 도구라고 생각하는 경우가 많았고, 과학적 진화론을 지지하는 응답자는 과학이 자연 세계에 대한 논리적이고 기술적인 체계라는 견해를 가지고 있었다. 신학 전공 대학생들이 현대 과학에 대한 이해와 관련한 과목을 수강한 이후, 젊은 지구 창조론과 같은 극단적 관점을 지지하는 경우가 23%에서 4%로 감소하였으며, 유신론적 진화론의 관점은 다소 증가하였다. 이는 신학 전공 대학생들의 과학 관련 과목 수강이 신학 전공의 바탕에서 과학적 진화론을 이해하려는 실마리를 제공한다고 볼 수 있다.

• 한국초등과학교육학회지:초등과학교육
• /
• 제41권2호
• /
• pp.173-185
• /
• 2022

이 연구의 목적은 2022 개정 교육과정의 고시를 앞두고 2007 개정 교육과정부터 2015 개정 교육과정까지의 초등 과학과 교육과정 중 지구와 우주 영역에 대해 반성적으로 검토하고 향후 교육과정 개정을 위한 과제를 제안하는 것이다. 이를 위하여 지구과학교육 전문가와 학교 현장의 초등교사를 대상으로 초등 과학과 교육과정에서 지구와 우주 영역 내용 요소와 내용 체계, 성취 기준과 탐구 활동 구성, 교육과정의 종적·횡적 연계성에 대해 FGI를 실시하였다. FGI를 통해 귀납적으로 도출한 개선 방향에 논리적 일관성을 확보하고자 자유 응답 문항과 가중치를 부여한 계층 분석 문항을 포함하였다. 분석 결과, 2015 개정 교육과정까지 초등 과학 지구와 우주 영역의 학년(군)별 단원 구성이 '지구계'의 각 권역별로 고르게 배분되어 있지 않고, 기초 개념이 부족한 것으로 나타났다. 학습 내용과 기능을 중심으로 서술한 성취 기준은 과학과 핵심역량이 구체적으로 드러나도록 진술할 필요성이 있으며, 다양한 형태의 탐구활동 유형과 학생 스스로 답을 찾는 과정이 포함되도록 탐구 활동을 구성할 필요성이 있다고 제안하였다. 계층 분석을 위한 문항에서는 내용 요소의 감축보다는 필수 내용 요소 포함, 흥미 중심의 현상 학습보다는 이해 중심의 개념 학습, 과목 간 통합 이전에 분과 기초 개념 학습, 학습 내용의 반복과 심화보다는 종적, 횡적 연계성의 확대를 제안하였다. 이 연구에서 제안한 내용이 초등 과학 '지구와 우주' 영역과 관련된 전문가들의 공통된 견해로 일반화하기에는 제한점이 있다. 그러나 2022 개정 교육과정의 주요 비전이 다양한 교육 주체의 참여를 통한 의견 수렴이므로 추후 교육과정의 개정 방향에 고려해야 할 여러 가지 의견 중 하나로 검토할 필요가 있음을 제안한다.

• 대한지구과학교육학회지
• /
• 제4권1호
• /
• pp.66-73
• /
• 2011

This study aims to compare and analyze the types of teaching-learning activities, themes and percentage of STS contents in the area of "The Earth and the Universe" in elementary science subject following the 7th Curriculum and 2007 Revised Curriculum, identifying how STS education has changed and their features. First, the number of pages where STS appears in the 2007 revised science textbook has increased over 10% compared to the that of the 7th curriculum. In particular, the number of pages in the 5th and 6th graders increased substantially to 15% and 34%, respectively. Second, as a result of analysis on components of STS, 'applications of science', 'local and community relevance', 'social problem and issues', 'evaluation concerned fir getting and using information' were obtained in the order named for the 7th curriculum; while 'applications of science', 'local and community relevance', 'career awareness' and 'social problem and issues' were obtained in the order named for 2007 revised curriculum. Third, with regard to the analysis on theme areas, the 7th curriculum was found to cover the theme on use of natural resources most frequently, followed by environmental problem, while 2007 revised curriculum to cover environmental problem and effects of technical development most frequently, followed by space development and use of natural resources. Fourth, in the area of STS teaching activities, 'investigation activity' showed highest percentage in 7th curriculum, followed by 'analysis of data', and 'research design', while 'analysis of data' showed highest frequency of appearance, followed by "investigation activity' and 'actual activities' and 'research design' in the order named in 2007 revised curriculum, showing that the area of 'analysis of data' and 'actual activities' increased substantially compared to the 7th curriculum.

• 천문학회보
• /
• 제43권1호
• /
• pp.59.4-60
• /
• 2018

To investigate the impact of the high-redshift quasars on cosmic reionization, the faint end slope of the quasars luminosity function has to be determined precisely. More quasars with low luminosity are needed to constrain the contribution to reionization in the early universe. However, finding these quasars has been regarded as tough process owing to the improper shallow depth of imaging data. In recent days, the release data of Subaru Hyper Suprime-Cam (HSC) Strategic Program survey which provide the deep images reaching ~ 25 mag facilitates searching the faint quasars candidates. To find faint quasar candidates in ELAIS-N1 field, along with the HSC data, two near-infrared (NIR) data sets also be used : The Infrared Medium-deep Survey (IMS) and The UKIRT Infrared Deep Sky Survey (UKIDSS) - Deep Extragalactic Survey (DXS). Quasar candidates selected from the multi-band color cut were observed by the SED camera for QUasars in EArly uNiverse (SQUEAN) instrument. To trace the redshifted Lyman break efficiently, appropriate medium bands comparable to targeted redshift range are chosen. The most reliable quasar candidates are finally determined through SED fitting. Using this less luminous quasars candidates, we can speculate the relation between the quasar growth and the host galaxy unbiasedly and estimate the contribution to the cosmic reionization.

• 천문학회보
• /
• 제42권2호
• /
• pp.55.2-55.2
• /
• 2017

We present a numerical code for the random scattering histories of Lyman alpha photons in the intergalactic medium. The numerical code calculates the radiative transfer under generic three dimensional density, ionization fraction, and peculiar velocity fields based on N-body + radiation transfer simulations of the epoch of reionization. The code is tested with models having analytical solutions, which have idealized geometry and simplified velocity fields. The emergent line profiles can give constraints to the ionization structure around Lyman alpha sources in the early universe.

• 천문학회지
• /
• 제52권1호
• /
• pp.11-21
• /
• 2019

Intensive Monitoring Survey of Nearby Galaxies (IMSNG) is a high cadence observation program monitoring nearby galaxies with high probabilities of hosting supernovae (SNe). IMSNG aims to constrain the SN explosion mechanism by inferring sizes of SN progenitor systems through the detection of the shock-heated emission that lasts less than a few days after the SN explosion. To catch the signal, IMSNG utilizes a network of 0.5-m to 1-m class telescopes around the world and monitors the images of 60 nearby galaxies at distances D < 50 Mpc to a cadence as short as a few hours. The target galaxies are bright in near-ultraviolet (NUV) with $M_{NUV}$ < -18.4 AB mag and have high probabilities of hosting SNe ($0.06SN\;yr^{-1}$ per galaxy). With this strategy, we expect to detect the early light curves of 3.4 SNe per year to a depth of R ~ 19.5 mag, enabling us to detect the shock-heated emission from a progenitor star with a radius as small as $0.1R_{\odot}$. The accumulated data will be also useful for studying faint features around the target galaxies and other science projects. So far, 18 SNe have occurred in our target fields (16 in IMSNG galaxies) over 5 years, confirming our SN rate estimate of $0.06SN\;yr^{-1}$ per galaxy.

• 대한한의학원전학회지
• /
• 제3권
• /
• pp.1-150
• /
• 1989

Oriental medicine thinks life and death as the following. 1. The universe seems to be a kind of organism which is divided into 3 branches, as Heaven, Earth and Man. Man is not created from nihil by the Creator. Heaven and Earth by their interaction operate to produce man. This is similiar that zygote is not created from nihil, and that sperm and ovum are transformed into zygote by their interaction. The symbolic meaning of sperm is Heaven, and that of ovum is Earth. Mind and body, as well as spirit and body, are not the real, but artificial words for the purpose of observing and expressing one man. So there is not spiritual substance as distinct from body. The expected life span of man is subjected to change, and is always becoming through life. Fate, the Creator and the world to come cannot be said to be. 2. After one's death, man is transformend into Heaven and Earth. Dying is this process of transformation. Although man comes into existence and closes one's life, the total life of the universe does not change. The criteria of determination of death is not in cell death, but in somatic death. Somatic death divided into 2 branches, one is heart-lung death, the other is brain death. For the standard of health changes ceaselessly as time goes by, aging and dying is not the process of losing health. Because of mind cannot be seperated from body, we'll feel at ease bodily and mentally in healthy dying. The completion of lifetimes is the value of healthy dying. 3. From the viewpoint of these, we must think to let a person die healthily is the right medical ethics. The way to let a person die healthily is divided into 3 branches, one is treatment, another is prevention and the other is promotion of health. We should treat and prevent death of sickness, but take care of healthy dying.

• 대한지구과학교육학회지
• /
• 제7권3호
• /
• pp.338-346
• /
• 2014

In this study, find out of recognition of the effect of science, society and ethical aspects on natural disasters and understanding degree of knowledge applying for SSI class aimed at elementary pre-service teachers by developing SSI training program of the 'Earth and Space' field. Also, after SSI class application we examined the change perceptions of elementary pre-service teachers. SSI training program was that elementary pre-service teachers participated in the SSI class of a variety of subjects in the field of 'Earth and Space' and directly joined in the decision-making process and reflectional discussion with colleagues as conducted in this class reflective discussion with the pre-primary teachers pre-service teachers. Elementary pre-service teachers were understanding of the nature of the science and to understand in more depth about the SSI class characteristics. This study, second grade 115 people who was taking 'science and teaching materials' course in B National University of Education at B city participated. In order to apply for SSI class, one semester based on 15 weeks until seven weeks were science and teaching materials and based on the nature of science, after 8 weeks we set the theme of the contents related to the Earth and space and give lesson applied for SSI. During 8 weeks, test subjects 4 classes were taking 50 minutes a week 100 minutes. First time has theoretical lessons in topics related to the 'Earth and space' and on the second week, each classes participate in the decision-making processes respectivly by dicussing and debating on the first week's topic as regarding social and moral aspects of it. We obtained the following results. First, elementary pre-service teachers were acquiring the results of 67% in the knowledge aspects of the 'Earth and space'. This result was determined that most of the elementary pre-service teachers were liberal arts in high school. Second, while participating in the SSI class, elementary pre-service teachers were concretely aware of the nature of SSI and the characteristics of the class. Third, the elementary pre-service teacher are thaught that introduction education courses about 'Earth and space' are needed but most of the students responded that this would require a lot of effort of teachers. This was derived from not familiar class form that did not fulfill in the science teaching methods until now.