Kim,Dong-jo

장재철,김동윤,박영순,전철,김동조 群山大學校 自然科學硏究所 1991 自然科學硏究 Vol.6 No.-

홍삼 추출물이 반치사량정도의 방사선(5Gy)에 조사된 생쥐조직 및 이들 조직에서의 효소활성에 미치는 영향을 관찰하기 위하여 ICR계 생쥐를 대상으로, 생리적 식염수군을 대조구군으로 하여, 홍삼 추출물 투여군과 방사선만을 조사한군 및 홍삼 추출물 투여후 방사선 조사군 등 4군으로 나누어 1일, 4일, 9일, 17일 및 30일 등 5회에 걸쳐 생체의 조직중 비장 및 고환에서의 중량 변화 및 GOT와 GPT의 활성을 측정하여 결과를 얻었다. 비장의 중량변화는 1일째 및 4일째 최소치를 보이다가 이후 증가추세를 보였으며, 고환의 중량 변화는 17일 이후 급격한 감소로 30일에도 증가하지 못했다. GOT의 활성도 변화는 비장에서는 초기에 현저히 증가했으며 이후 회복하는 경향이었다. 방사선 조사군들에서는 홍삼추출물 투여군이 방사선만을 조사한 군보다 빠르게 회복하는 경향이었으며 고환에서의 GOT활성은 매우 불안정하였다. GPT 활성도 변화는 비장, 고환에서 모두 초기에 증가하다가 점차 회복하는 경향이었으며 홍삼 추출물 투여후 방사선 조사군이 방사선만을 조사한군보다 빠르게 회복하는 경향이었다. 이러한 결과로 볼 때 홍삼 추출물은 방사선 조사에 의하여 기인된 비장 및 고환의 GOT와 GPT활성도 증가에 방호효과가 있다고 생각된다. This study was prepared to observe the change of tissues weight, glutamate oxaloacetate transminase(GOT) and glutamate pyruvate transminase(GPT) activities in the spleen and testis treated with red ginseng extract injection in the gamma ray irradiated mice. Groups were divided into control, red ginseng extract injection, irradiation after saline injection and irradiation after red ginseng extract injection. The spleen and testis weights were decreased at 17th day irradiation after saline injection and irradiation after red ginseng extract injection. The GOT activity showed earlier recovery at irradiation after red ginseng extract injection group than irradiation after saline injection group in the spleen. The GPT activity showed earlier recovery at irradiation after red ginseng extract injection group than irradiation after saline injection group in the spleen and testis. The above result suggest that red ginseng extract have the recovery effect on the change GOT and GPT activity after radiation injury in the spleen and testis of mice.

Energy dissipation of steel-polymer composite beam-column connector

Yun-Che Wang,Chih-Chin Ko 국제구조공학회 2015 Steel and Composite Structures, An International J Vol.18 No.5

The connection between a column and a beam is of particular importance to ensure the safety of civil engineering structures, such as high-rise buildings and bridges. While the connector must bear sufficient force for load transmission, increase of its ductility, toughness and damping may greatly enhance the overall safety of the structures. In this work, a composite beam-column connector is proposed and analyzed with the finite element method, including effects of elasticity, linear viscoelasticity, plasticity, as well as geometric nonlinearity. The composite connector consists of three parts: (1) soft steel; (2) polymer; and (3) conventional steel to be connected to beam and column. It is found that even in the linear range, the energy dissipation capacity of the composite connector is largely enhanced by the polymer material. Since the soft steel exhibits low yield stress and high ductility, hence under large deformation the soft steel has the plastic deformation to give rise to unique energy dissipation. With suitable geometric design, the connector may be tuned to exhibit different strengths and energy dissipation capabilities for real-world applications.

Effects of thickness variations on the thermal elastoplastic behavior of annular discs

Yun-Che Wang,Sergei Alexandrov,Yeau-Ren Jeng 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.47 No.6

Metallic annular discs with their outer boundary fully constrained are studied with newly derived semi-analytical solutions for the effects of thickness variations under thermal loading and unloading. The plane stress and axisymmetric assumptions were adopted, and the thickness of the disk depends on the radius hyperbolically with an exponent n. Furthermore, it is assumed that the stress state is two dimensional and temperature is uniform in the domain. The solutions include the elastic, elastic-plastic and plasticcollapse behavior, depending on the values of temperature. The von Mises type yield criterion is adopted in this work. The material properties, Young’s modulus, yield stress and thermal expansion coefficient, are assumed temperature dependent, while the Poisson’s ratio is assumed to be temperature independent. It is found that for any n values, if the normalized hole radius a greater than 0.6, the normalized temperature difference between the elastically reversible temperature and plastic collapse temperature is a monotonically decreasing function of inner radius. For small holes, the n values have strong effects on the normalized temperature difference. Furthermore, it is shown that thickness variations may have stronger effects on the strain distributions when temperature-dependent material properties are considered.

《아시연설가(我是演說家)》우승자와 준우승자의 레토릭 지수 비교 분석

제윤지 ( Che Yun Ji ),나민구 ( Na Min Gu ) 한국외국어대학교 중국연구소 2019 中國硏究 Vol.81 No.-

This paper aims to find out how rhetorical the rhetoric effect is in the speeches of the winners and runners-ups in the final round of the fifth final title. The subjects of this paper are the speeches of the winners and runner-ups who won the 5th and 10th finalist finals of “I Am a Speaker”, which aired on Beijing TV on March 6, 2019. These speeches have images as well as texts, so we will look at the rhetorical expressions in the text and the speech and gesture language of the speakers. In addition, photographs presented as background data on stage when the winner and the runner-up each speak will be included in the analysis.In this paper, we will apply the “Rhetorical Sensitivity Scale”, which quantifies the ability of persuasion as a methodology, and sets up the evaluation items based on the traditional theory of rhetoric and then analyzes two speeches. The traditional theory of rhetoric can be divided into five areas and three persuasive elements. The five areas include idea, disposition, expression, memory, and action delivery. The three persuasion elements are Ethos, Logos, and Pathos.In order to pursue objectivity as much as possible, this paper will proceed with both text analysis with verbal expression and video analysis with field situations at the time of speech.

Effects of thickness variations on the thermal elastoplastic behavior of annular discs

Wang, Yun-Che,Alexandrov, Sergei,Jeng, Yeau-Ren Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.47 No.6

Metallic annular discs with their outer boundary fully constrained are studied with newly derived semi-analytical solutions for the effects of thickness variations under thermal loading and unloading. The plane stress and axisymmetric assumptions were adopted, and the thickness of the disk depends on the radius hyperbolically with an exponent n. Furthermore, it is assumed that the stress state is two dimensional and temperature is uniform in the domain. The solutions include the elastic, elastic-plastic and plastic-collapse behavior, depending on the values of temperature. The von Mises type yield criterion is adopted in this work. The material properties, Young's modulus, yield stress and thermal expansion coefficient, are assumed temperature dependent, while the Poisson's ratio is assumed to be temperature independent. It is found that for any n values, if the normalized hole radius a greater than 0.6, the normalized temperature difference between the elastically reversible temperature and plastic collapse temperature is a monotonically decreasing function of inner radius. For small holes, the n values have strong effects on the normalized temperature difference. Furthermore, it is shown that thickness variations may have stronger effects on the strain distributions when temperature-dependent material properties are considered.

상대(商代)의 천문현상(天文現象) 연구(硏究)-문자 이미지를 중심으로-

제윤지 ( Yun Ji Che ),박흥수 ( Heung-soo Park ) 한국외국어대학교 언어연구소 2017 언어와 언어학 Vol.0 No.75

This paper is purposed to study that the shape of Chinese characters were reflected by the astronomical phenomenon. In Chapter 2, we suggest that the original meaning of 日, 月was celestial body and could be extended to the concept of a day and month. 星was the Chinese character that collectively meant for shining things at night. 圭had the meaning of a jade written in < Shuowenjiezi >, as well as the meaning of astronomical observation instrument. In Chapter 3, we maintain that the shape of the Chinese characters of a day reflected the astronomical movement process. The Chinese characters of expressing “day”, 旬means same meaning as the original meaning of 10 days in the present, “年” indicates a year as it took a year before the grain ripening. In Chapter 4 shows that 屯meant Spring in oracle bone script, but it has been changed to defense or difficult now. In addition, the Chinese characters meaning the seasons were made by the relation with weather`s natural phenomena.

Stress analysis of a two-phase composite having a negative-stiffness inclusion in two dimensions

Wang, Yun-Che,Ko, Chi-Ching Techno-Press 2009 Interaction and multiscale mechanics Vol.2 No.3

Recent development in composites containing phase-transforming particles, such as vanadium dioxide or barium titanate, reveals the overall stiffness and viscoelastic damping of the composites may be unbounded (Lakes et al. 2001, Jaglinski et al. 2007). Negative stiffness is induced from phase transformation predicted by the Landau phase transformation theory. Although this unbounded phenomenon is theoretically supported with the composite homogenization theory, detailed stress analyses of the composites are still lacking. In this work, we analyze the stress distribution of the Hashin-Shtrikman (HS) composite and its two-dimensional variant, namely a circular inclusion in a square plate, under the assumption that the Young's modulus of the inclusion is negative. Assumption of negative stiffness is a priori in the present analysis. For stress analysis, a closed form solution for the HS model and finite element solutions for the 2D composite are presented. A static loading condition is adopted to estimate the effective modulus of the composites by the ratio of stress to average strain on the loading edges. It is found that the interfacial stresses between the circular inclusion and matrix increase dramatically when the negative stiffness is so tuned that overall stiffness is unbounded. Furthermore, it is found that stress distributions in the inclusion are not uniform, contrary to Eshelby's theorem, which states, for two-phase, infinite composites, the inclusion's stress distribution is uniform when the shape of the inclusion has higher symmetry than an ellipse. The stability of the composites is discussed from the viewpoint of deterioration of perfect interface conditions due to excessive interfacial stresses.

Molecular dynamics studies of interaction between hydrogenand carbon nano-carriers

Wang, Yun-Che,Wu, Chun-Yi,Chen, Chi,Yang, Ding-Shen Techno-Press 2014 Coupled systems mechanics Vol.3 No.4

In this work, quantum molecular dynamics simulations (QMD) are preformed to study the hydrogen molecules in three types of carbon nanostructures, $C_{60}$ fullerene, (5,5) and (9,0) carbon nanotubes and graphene layers. Interactions between hydrogen and the nanostructures is of importance to understand hydrogen storage for the development of hydrogen economy. The QMD method overcomes the difficulties with empirical interatomic potentials to model the interaction among hydrogen and carbon atoms in the confined geometry. In QMD, the interatomic forces are calculated by solving the Schrodinger's equation with the density functional theory (DFT) formulation, and the positions of the atomic nucleus are calculated with the Newton's second law in accordance with the Born-Oppenheimer approximation. It is found that the number of hydrogen atoms that is less than 58 can be stored in the $C_{60}$ fullerene. With larger carbon fullerenes, more hydrogen may be stored. For hydrogen molecules passing though the fullerene, a particular orientation is required to obtain least energy barrier. For carbon nanotubes and graphene, adsorption may adhere hydrogen atoms to carbon atoms. In addition, hydrogen molecules can also be stored inside the nanotubes or between the adjacent layers in graphite, multi-layer graphene.

Molecular dynamics studies of interaction between hydrogenand carbon nano-carriers

Wang, Yun-Che,Wu, Chun-Yi,Chen, Chi,Yang, Ding-Shen Techno-Press 2013 Interaction and multiscale mechanics Vol.6 No.3

In this work, quantum molecular dynamics simulations (QMD) are preformed to study the hydrogen molecules in three types of carbon nanostructures, $C_{60}$ fullerene, (5,5) and (9,0) carbon nanotubes and graphene layers. Interactions between hydrogen and the nanostructures is of importance to understand hydrogen storage for the development of hydrogen economy. The QMD method overcomes the difficulties with empirical interatomic potentials to model the interaction among hydrogen and carbon atoms in the confined geometry. In QMD, the interatomic forces are calculated by solving the Schrodinger's equation with the density functional theory (DFT) formulation, and the positions of the atomic nucleus are calculated with the Newton's second law in accordance with the Born-Oppenheimer approximation. It is found that the number of hydrogen atoms that is less than 58 can be stored in the $C_{60}$ fullerene. With larger carbon fullerenes, more hydrogen may be stored. For hydrogen molecules passing though the fullerene, a particular orientation is required to obtain least energy barrier. For carbon nanotubes and graphene, adsorption may adhere hydrogen atoms to carbon atoms. In addition, hydrogen molecules can also be stored inside the nanotubes or between the adjacent layers in graphite, multi-layer graphene.

미세 다공질 광물과 아미드계 분해제의 적용을 통한 건축자재의 습도 조절과 폼알데히드 분해 성능 특성 평가

이제철(Lee, Che Cheol),김윤환(Kim, Yun Hwan),윤승희(Yun, Seng Hee) 한국생태환경건축학회 2014 한국생태환경건축학회 논문집 Vol.14 No.3