• 대한예방한의학회지
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• 제11권1호
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• pp.109-129
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• 2007

This study aims at grasping the relativity between laborers' yangseng level and stress so as to present the groundwork for preventive oriental medicine approach in industrial health. The researcher prepared the questionnaire on general character, health-related yangseng level and chose 632 people to execute Autonomic balance test through heartbeat change. The collected material was analyzed by SPSS and tested by T-test, ANOVA. The general yangseng level average is 3.27, morality yangseng 3.91, sleep yangseng 3.39, mind yangseng 3.32, sex life yangseng 3.29, exercise yangseng 3.14, activities and rest yangseng 3.07, diet yangseng 2.95, seasonal yangseng 2.84. The highest is morality yangseng and seasonal yangseng is the lowest. In the aspect of yangseng level : Having a spouse, Non-smoking, Non-drinking, Regular exercising, Sufficient sleeping have higher yanseng levels. In Autonomic balance test, age from 35 to 40 has the highest autonomic activity and job period from 5 years to 10 years has the highest stress resistance. Non-smokers have high autonomic activity and stress resistance. Further, have low autonomic balance, stress index and fatigue strength. In the case of regular exercising person, he/she has high autonomic activity and stress resistance with low stress index. Regarding sleeping time, autonomic balance is the highest when he/she sleeps less than 6 hours. Stress resistance is the highest when he/she sleeps 7 hours and stress index is the highest when he/she sleeps 6 hours. After comparing the relativity between yangseng level autonomic balance test, only exercise yangseng has plus factor on autonomic activity and stress resistance and minus factor on stress ind ex and fatigue strength. Yangseng level has been affected by individual character and daily habits. Also stress is more influenced by daily habits than by individual character. We can find the relativity of exercise yangseng between yangseng and stress which suggests that we need to take measures to win over stress in individual health in the near future.

• 대한의료기공학회지
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• 제10권1호
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• pp.100-129
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• 2007

This study aims at grasping the relativity between laborers' yangseng level and stress so as to present the groundwork for preventive oriental medicine approach in industrial health. The researcher prepared the questionnaire on general character, - health-related yangseng level and chose 632 people to execute Autonomic balance test through heartbeat change. The collected material was analyzed by SPSS and tested by T-test, ANOVA The general yangseng level average is 3.27, morality yangseng 3.91, sleep yangseng 3.39, mind yangseng 3.32, sex life yangseng 3.29, exercise yangseng 3.14, activities and rest yangseng 3.07, diet yangseng 2.95, seasonal yangseng 2.84. The highest is morality yangseng and seasonal yangseng is the lowest. In the aspect of yangseng level: Having a spouse, Non-smoking, Non-drinking, Regular exercising, Sufficient sleeping have higher yangseng levels. In Autonomic balance test, age from 35 to 40 has the highest autonomic activity and job period from 5 years to 10 years has the highest stress resistance. Non-smokers have high autonomic activity and stress resistance. Further, have low autonomic balance, stress index and fatigue strength. In the case of regular exercising person, he/she has high autonomic activity and stress resistance with low stress index. Regarding sleeping time, autonomic balance is the highest when he/she sleeps less than 6 hours. Stress resistance is the highest when he/she sleeps 7 hours and stress index is the highest when he/she sleeps 6 hours. After comparing the relativity between yangseng level autonomic balance test, only exercise yangseng has plus factor on autonomic activity and stress resistance and minus factor on stress index and fatigue strength. Yangseng level has been affected by individual character and daily habits. Also stress is more influenced by daily habits than by individual character. We can find the relativity of exercise yangseng between yangseng and stress which suggests that we need to take measures to win over stresses in individual health in the near future.

• 대한수학회보
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• 제25권2호
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• pp.195-201
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• 1988

In general relativity, analyzing causality is central to the study of black holes, to cosmology, and to each of the major recent mathematical theorems. By causality we refer to the general question of which points in a space-time can be joined by causal curves; relativistically which events can influence (be influenced by) a given event. Various causality conditions have been developed for space-times of the problems associated with examples of causality violations (2, 4). Causally continuous space-times were defined by Hawking and Sachs (5). Budic and Sachs (3) established causal completion. A metrizable topology on the causal completion of a causally continuous space-time was studied by Beem(1). Recently the region of space-time where causal continuity is violated was studied by Ishikawa (6) and Vyas and Akolia (8). In this paper we show characterization for reflectingness in terms of continuity of set valued functions. We investigate some properties of the region related to a causally continuous space-time where distinguishingness is violated, and characterize the chronology condition in terms of distinguishing-violated region.

• 천문학회지
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• 제45권4호
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• pp.101-110
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• 2012

I present here one approach to general relativistic radiation hydrodynamics. It is based on covariant tensor conservation equations and considers only the frequency-integrated total energy and momentum exchange between matter and the radiation field. It is also a mixed-frame formalism in the sense that, the interaction between radiation and matter is described with quantities in the comoving frame in which the interaction is often symmetric in angle while the radiation energy and momentum equations are expressed in the fixed frame quantities in which the derivatives are simpler. Hence, this approach is intuitive enough to be applied straightforwardly to any spacetime or coordinate. A few examples are provided along with caveats in this formalism.

• Journal of Astronomy and Space Sciences
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• 제38권1호
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• pp.39-44
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• 2021

In the general accretion disk model theory, the accretion disk surrounding an astronomical object comprises fluid rings obeying Keplerian motion. However, we should consider relativistic and rotational effects as we close in toward the center of accretion disk surrounding spinning compact massive objects such as a black hole or a neutron star. In this study, we explore the geometry of the inner portion of the accretion disk in the context of Mukhopadhyay's pseudo-Newtonian potential approximation for the full general relativity theory. We found that the shape of the accretion disk "puffs up" or becomes thicker and the luminosity of the disk could exceed the Eddington luminosity near the surface of the compact spinning black hole.

• 천문학회지
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• 제34권4호
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• pp.191-201
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• 2001

My contribution to these proceedings summarizes a general overview on High Resolution Shock Capturing methods (HRSC) in the field of relativistic hydrodynamics with special emphasis on Riemann solvers. HRSC techniques achieve highly accurate numerical approximations (formally second order or better) in smooth regions of the flow, and capture the motion of unresolved steep gradients without creating spurious oscillations. In the first part I will show how these techniques have been extended to relativistic hydrodynamics, making it possible to explore some challenging astrophysical scenarios. I will review recent literature concerning the main properties of different special relativistic Riemann solvers, and discuss several 1D and 2D test problems which are commonly used to evaluate the performance of numerical methods in relativistic hydrodynamics. In the second part I will illustrate the use of HRSC methods in several astrophysical applications where special and general relativistic hydrodynamical processes play a crucial role.

• 대한지구과학교육학회지
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• 제16권1호
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• pp.13-29
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• 2023

본 연구는 대칭성에 대해 이론적으로 고찰하고 이의 과학교육적 함의를 도출하는 것을 목표로 한다. 이를 위해 첫째, 고대 그리스 학자들을 통해 일반적인 서양 과학의 사유방식을 살펴보았다. 둘째, 대칭성에 대한 인식을 고대와 근현대로 나누어 살펴보았다. 셋째, 이에 대한 과학교육적 함의를 도출하였다. 본 연구의 결과는 첫째, 서양 과학의 사유방식은 파르메니데스에서 시작되어 플라톤이 정립한 '추상화'이다. 둘째, 고대의 대칭성 인식은 추상화를 기반으로 한 아름다운 비율과 조화로서의 대칭성, 근현대의 대칭성 인식은 변화에서 불변을 찾고자 했던 추상화를 기반으로 한 불변의 관점으로서의 대칭성이다. 그리고 고대의 대칭성의 예시로서 에라토스테네스의 지구 둘레 측정 실험에 대해 고찰하였으며, 근현대의 대칭성의 예시로서 갈릴레이 상대성 및 변환을 고찰하였다. 셋째, 이에 따른 과학교육적 함의는 다음과 같다. 대칭성에 대한 인식은 고대부터 근현대 과학을 관통하는 핵심주제라는 관점에서 과학의 본성 교육에 도움이 될 수 있다. 둘째, 에라토스테네스 지구 둘레 측정 실험과 갈릴레이 상대성 및 변환의 경우 2022 개정 교육과정에는 제시되어 있지 않지만 과학과 핵심역량 및 개념 이해에 도움이 될 수 있다. 마지막으로, 대칭성을 중심으로한 통합적 접근으로의 과학교육은 과학적 태도와 흥미에 긍정적인 영향을 줄 수 있다.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2000년도 춘계 학술대회 및 국제 감성공학 심포지움 논문집 Proceeding of the 2000 Spring Conference of KOSES and International Sensibility Ergonomics Symposium
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• pp.39-46
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• 2000

The imploded open $\pi$-rays comprise of the space and their diameters are distributed from nearly zero to infinite. The change of the potential energy in the open $\pi$-ray produces an attraction force between them and it is sensible to the geometric shape factor and its frequency. The equivalent principle of general relativity means that in the wave equation its velocity of the force wave is infinite. The change of the state in a open $\pi$-ray(or any force wave) can be transferred to any sensible open $\pi$-ray via space at a finite velocity. Many properties of the light wave can be deduce from the motions of open $\pi$-rays.The nonsteady and steady Schr dinger equations include the dynamics of open $\pi$-rays and closed $\pi$-rays.$\prod$-ray is a tool of entity for constructing physics and metaphysics at the same time.

• 천문학회보
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• 제43권1호
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• pp.62.2-62.2
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• 2018

From the gaussian, near scale-invariant density perturbations observed in the CMB to the late time clustering of galaxies, CDM provides a minimal theoretical explanation for a variety of cosmological data. However accepting this explanation, requires that we include within our cosmic ontology a vacuum energy that is ~122 orders of magnitude lower than QM predictions, or alternatively a new scalar field (dark energy) that has negative pressure. Alternatively, modifications to Einstein's General Relativity have been proposed as a model for cosmic acceleration. Recently there have been many works attempting to test for modified gravity using the large scale clustering of galaxies, ISW, cluster abundance, RSD, 21cm observations, and weak lensing. In this work, we compare various modified gravity models using cosmic shear data from the Deep Lens Survey as well as data from CMB, SNe Ia, and BAO. We use the Bayesian Evidence to quantify the comparison robustly, which naturally penalizes complex models with weak data support. In this poster we present our methodology and preliminary constraints on f(R) gravity.

• 논리연구
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• 제12권2호
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• pp.171-199
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• 2009

본 논문은 형식적인 조건을 통하여 뉴턴 물리학에서 아인슈타인 물리학으로의 이론변화의 연속성을 이해하려는 과학이론에 대한 진보적 견해를 비판적으로 고찰한다. '상응 원리'이나 '공변 원리'와 같은 형식적인 측면이 이 이론변화에서 중요한 정보를 담고 있는 것은 부정할 수 없지만, 이 형식적 속성은 뉴턴역학에서 아인슈타인의 특수 그리고 일반 상대성 이론으로의 발전에 대한 진화적 견해를 위한 본질적 요소를 제공하기에는 충분치 않다.