• Journal of The Korean Astronomical Society
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• v.47 no.2
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• pp.77-86
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• 2014

Using a cosmological ${\Lambda}CDM$ simulation, we analyze the differences between the widely-used spin parameters suggested by Peebles and Bullock. The dimensionless spin parameter ${\lambda}$ proposed by Peebles is theoretically well-justified but includes an annoying term, the potential energy, which cannot be directly obtained from observations and is computationally expensive to calculate in numerical simulations. The Bullock's spin parameter ${\lambda}^{\prime}$ avoids this problem assuming the isothermal density profile of a virialized halo in the Newtonian potential model. However, we find that there exists a substantial discrepancy between ${\lambda}$ and ${\lambda}^{\prime}$ depending on the adopted potential model (Newtonian or Plummer) to calculate the halo total energy and that their redshift evolutions differ to each other significantly. Therefore, we introduce a new spin parameter, ${\lambda}^{\prime\prime}$, which is simply designed to roughly recover the value of ${\lambda}$ but to use the same halo quantities as used in ${\lambda}^{\prime}$. If the Plummer potential is adopted, the ${\lambda}^{\prime\prime}$ is related to the Bullock's definition as ${\lambda}^{\prime\prime}=0.80{\times}(1+z)^{-1/12}{\lambda}^{\prime}$. Hence, the new spin parameter ${\lambda}^{\prime\prime}$ distribution becomes consistent with a log-normal distribution frequently seen for the ${\lambda}^{\prime}$ while its mean value is much closer to that of ${\lambda}$. On the other hand, in case of the Newtonian potential model, we obtain the relation of ${\lambda}^{\prime\prime}=(1+z)^{-1/8}{\lambda}^{\prime}$; there is no significant difference at z = 0 as found by others but ${\lambda}^{\prime}$ becomes more overestimated than ${\lambda}$ or ${\lambda}^{\prime\prime}$ at higher redshifts. We also investigate the dependence of halo spin parameters on halo mass and redshift. We clearly show that although the ${\lambda}^{\prime}$ for small-mass halos with $M_h$ < $2{\times}10^{12}M_{\odot}$ seems redshift independent after z = 1, all the spin parameters explored, on the whole, show a stronger correlation with the increasing halo mass at higher redshifts.

• Journal of Korean Philosophical Society
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• v.137
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• pp.109-130
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• 2016

Plato learned of teleology from his teacher Socrates and expanded it to its application in cosmology. His cosmological work Timaeus was the final edition of teleological view. The motive that Demiurge created the cosmos was in resemblance of his goodness. He then modeled the idea of the Good imposing limit to the Forms of Good in a material world. In this sense, Demiurge was an excellent creator and created the Good cosmos. The cosmic body was made from four elements (water, fire, air, earth) and the cosmic soul entered the cosmic body and the cosmic intelligence (nous) entered the cosmic soul. According to these steps, this cosmos was created and named a living god. In conclusion, Plato asserts that this cosmos was created by God's teleological project, and resembles the goodness of a god. When man followed the order and balance in the cosmos, the good of the individual and the state would be accomplished.

• The Journal of Korean Philosophical History
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• no.35
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• pp.385-413
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• 2012

This thesis is a study on the relation of between Xiangshu Zhouyi Theory and mathematics, Zhouyi Theory as the one of the study of Chinese classics, was formed by Zhouyi' Eight Diagrams, the theory of Yinyangwuxing and the knowledge of natural science in Han dynasty. 'Xiangshu' had been regarded as the important concept and theory in the history of Zhouyi Theory From the beginning of Han dynasty to the end of Qing dynasty. At this developing of this Periodical Change, 'Xiangshu' had been endoded in the expression system of mathematics. This thesis considers binary system and surplus nembers, multiple and progression, magic square and circular constant, a proportional expression from Zhouyi Theory point of view. Xiangshu Zhouyi theory got the answer of these questions like the origin of Zhouyi, interpreting Guayao-word and Cosmology by using those expression systems of mathematics. Besides mathematics, Xiangshu Zhouyi theory was also related to astronomy, medicine, etc. Xiangshu Zhouyi theory had kept the pace with the general development of natural science. This thesis from the premise that Xiangshu Zhouyi theory kept the pace with natural science, summing up the mathematical expression system in the history of Zhouyi theory, proves that Xiangshu Zhouyi theory had developed according as the conditions of natural science.

• Journal of Astronomy and Space Sciences
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• v.22 no.4
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• pp.377-384
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• 2005

Since gamma-ray bursts(GRBs) have been first known to science societites in 1973, many scientists are involved in their studies. Observations of GRB afterglows provide us with much information on the environment in which the observed GRBs are born. Study of GRB afterglows deals with longer timescale emissions in lower energy bands (e.g., months or even up to years) than prompt emissions in gamma-rays. Not all the bursts accompany afterglows in whole ranges of waveleogths. It has been suggested as a reason for that, for instance, that radio and/or X-ray afterglows are not recorded mainly due to lower sensitivity of detectors, and optical afterglows due to extinctions in intergalactic media or self-extinctions within a host galaxy itself. Based on the idea that these facts may also provide information on the GRE environment, we analyze statistical properties of GRB afterglows. We first select samples of the redshift-known GRBs according to the wavelength of afterglow they accompanied. We then compare their distributious as a function of redshift, using statistical methods. As a results, we find that the distribution of the GRBs with X-ray afterglows is consistent with that of the GRBs with optical afterglows. We, therefore, conclude that the lower detection rate of optical afterglows is not due to extinctions in intergalactic media.

• The Journal of Korean Philosophical History
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• no.56
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• pp.81-117
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• 2018

The purpose of this study is to clarify the overall features and its meaning of the Gaebyok(開闢) through the intercomparison of the Gaebyok idea that is the core idea of a newly risen modern religion in Korea. Limitation of most studies so far is that they have stayed in the fragmentary study on the Gaebyok idea of each new religion. In order to overcome this problem, first of all, the Gaebyok idea was studied from a philosophical point encompassing the cosmological view of time in the book of changes. And based on this methodological foundation, with organizing the existing result of study, the process of development and characteristics in the Gaebyok idea of a posteriori Donghak(東學), Right I Ching (正易), Won Buddhism(圓佛敎), and Kangjeungsan(姜甑山) was investigated respectively. And through comparing and analyzing each Gaebyok idea, the similarities and differences between each other were organized. The founders of new religions thought that a great change in the universal and natural luck was made before and after the point of their living. The concept of the frequency of revolution theory is the concept to explain the aspect of transition according to the frequency of revolution(運度) of the cosmological nature that returns to the beginning, and in the idea of the posterior Gaebyok, this content and concepts is contained as it was. This study showed that the concept of the frequency of revolution theory in an apriority and a posterior like those becomes appeared in some preaches of Suun, Ilbu, Sotaesan and Jeungsan. An apriority in the Gaebyok idea of new religion is the world of crisis that represents the limited condition of human being, and a posterity means the religious ideal world realized through the power of the absolute being or a dramatic universal change from that limited circumstances. So the Gaebyok ida is a kind of an universal eschatology and religious view that expects the coming of ideal world in the future. In addition, since the universal eschatology is a kind of a view of time, it inevitably has an issue how long time apriority and a posterity included in it have. And especially, it becomes to premise the content how the social condition and human condition change in an apriority and a posterity. Accordingly, in this study, based on the understanding of the view of time in the cosmological level, the content of answers that each newly risen religion discloses was listed and analyzed with comparison. It can be considered that Suun took charge of a mission to deliver the message through being possessed of a god in heaven who is able to be called a transcendental existence, Ilbu disclosed the coming of the world of a posterity beyond an apriority through the Book of Changes(易學), Jeungsan proclaimed himself as the absolute being who could make such a posterity and bring it, and Sotaesan proposed the Gaebyok of mind in order to meet with the world of a posterity and to live in that era.

• Journal of the Daesoon Academy of Sciences
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• v.21
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• pp.99-156
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• 2013

This paper is to indicate research tendencies of faith in Daesoonjinrihoe and controversial points of those, and to consider the outlook on Sangje after defining it as theological understanding and explanation for Gu-Cheon-Sang-Je (High-est ruling Entity that is the object of devotion in Daesoon-jinrihoe). As the first introduction to the work, various descriptions for Sangje are arranged and the meanings of those are analyzed. In brief, first, the name of Gu-Cheon-Eung-Won-Nweh-Seong-Bo-Hwa-Cheon-Jon, expresses the fact that the authority of Sangje (the Supreme Entity) is exposed by spatial concept Sangje dwells in Ninth Heaven. This fact can be compared with the doctrines Allah in Islam and Jehovah in Christianity each are dwelled in Seventh Heaven. And the name shows Sangje is the ruler who reigns over the universe by using yin and yang. Second, the name, Gu-Cheon-Eung-Won-Nweh-Seong-BoHwa-Cheon-Jon, is imported from China Taoism because it has been in Ok-Chu-Gyeong (the Gaoshang shenlei yushu). But in fact it's root is in Korea because Buyeo and Goguryeo, the ancient Korean nations, have the source of the name. While the name is not the Supreme Entity in China Taoism, it is the Supreme Entity in Daesoonjinrihoe. This fact is a important difference. Third, arbitrarily or not, the name, Gu-Cheon-Eung-Won-Nweh-Seong-Bo-Hwa-Cheon-Jon, is put on the image of 'resolution of grievances'. The reason is that many peoples in Korea and China has called the name for about 1,000 years ago to help their fortunes and escape predicaments. Forth, not only Gu-Cheon-Eung-Won-Nweh-Seong-Bo-Hwa-Cheon-Jon but also the name, Three Pure Ones and Ok-Cheon-Jin-Wang (Yuqingzhenwang) in China Taoism used as the Highest ruling Entity in Daesoonjinrihoe. But the relations between three Pure Ones and Ok-Cheon-Jin-Wang and Gu-Cheon-Eung-Won-Nweh-Seong-Bo-Hwa-Cheon-Jon in Dae-soonjinrihoe are different from that in China Taoism. Fifth, Sangje is associated with the Polaris divinity of Tae-Eul, view on God in Oriental Cosmology. The description Tae-Eul as well as Gu-Cheon-Eung-Won-Nweh-Seong-Bo-Hwa-Cheon-Jon is indicated Sangje is linked to the faith of Buyeo and Goguryeo. Sixth, Sangje is not only Mugeuk-Sin (The God of The Endless) who supervise the Endless but also Taegeuk-Ji-Cheon-Jon (The God of The Ultimate Reality) who supervise the Ultimate Reality. These descriptions directly display the fact Sangje is a creator. Seventh, in case explaining Sangje, the point of view is necessary that grasps the whole viewpoints Sangje 'was' Hidden God(deus otiosus) and 'is' Unhidden God after Incarnation. Eighth, Sangje is Cheon-Ju in Donghak, but different from that. Cheon-Ju in Donghak has both transcendence and immanence in tightrope tension, but Cheon-Ju in Daesoonjinrihoe emphasize transcendence than immanence. That difference is the result of the fact Cheon-Ju in Donghak was a being having revealed a man and Cheon-Ju in Daesoonjinrihoe was a being having incarnated after revealing a man. Ninth, Sangje is Gae-Byeok-Jang who is the manager of the transforming and ordering the Three Realms of the World by the Great Do which is the mutual beneficence of all life and Hae-Won-Sin who is the God of resolution of grievances.