Anticlastogenic Effects of Galangin against N-Methyl-N'-nitro-N-nitrosoguanidine-induced Micronuclei in Bone-marrow CElls of C57BL/6 Mice

Heo, Moon Young,Sohn, Dong Hun,Kim, Kyeong Ho,Lee, Su Jun,Kwon, Chang Ho,William W. Au4 한국응용약물학회 1993 Biomolecules & Therapeutics(구 응용약물학회지) Vol.1 No.2

The anticlastogenic effect of galangin, flavonoid derivative, was studied in vivo micronucleus test using C57BL/6 mice. The frequencies of micronuclei induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in bone-marrow cells of C57BL/6 mice were significantly decreased by the simultaneous treatment or multiple pre-treatment of galangin. When galangin was orally administered at 0, 0.1, 1.0, or 10.0 mg/kg twice with 24 hr interval, together with intraperitoneally administered MNNG, there were suppressive effects in the tested doses. The most marked suppressive effect was observed in the treatment group of 1.0 mg/kg (64.5%), not in the treatment group of 10.0 mg/kg (36.3%). When galangin was multiply administered at 1/7 or 1 mg/kg for 7 days respectively, galangin showed higher suppressive effect in the treatment group of 1/7 mg/kg (23.5%) rather than in the treatment group of 1 mg/kg (13.5%). In another experiment, galangin was administered at 0.001, 0.01 or 0.1 mg/kg for 1 month respectively. The suppressive effects in one month treatment gradually increased with dose-dependent manner, although suppressive effects were not high. The results showed that galangin was effective in suppressing the frequencies of micronuclei induced by MNNG. Our study indicates that galangin is a potent anticlastogenic agent against MNNG.

Simulation of vibrations of Ting Kau Bridge due to vehicular loading from measurements

Au, F.T.K.,Lou, P.,Li, J.,Jiang, R.J.,Zhang, J.,Leung, C.C.Y.,Lee, P.K.K.,Lee, J.H.,Wong, K.Y.,Chan, H.Y. Techno-Press 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.40 No.4

The Ting Kau Bridge in Hong Kong is a cable-stayed bridge comprising two main spans and two side spans. The bridge deck is supported by three towers, an end pier and an abutment. Each of the three towers consists of a single reinforced concrete mast strengthened by transverse cables and struts. The bridge deck is supported by four inclined planes of cables emanating from anchorages at the tower tops. In view of the heavy traffic on the bridge, and threats from typhoons and earthquakes originated in areas nearby, the dynamic behaviour of long-span cable-supported bridges in the region is always an important consideration in their design. Baseline finite element models of various levels of sophistication have been built not only to match the bridge geometry and cable forces specified on the as-constructed drawings but also to be calibrated using the vibration measurement data captured by the Wind and Structural Health Monitoring System. This paper further describes the analysis of axle loading data, as well as the generation of random axle loads and simulation of vibrations of the bridge using the finite element models. Various factors affecting the vehicular loading on the bridge will also be examined.

날갯짓 기능을 가진 도약 로봇의 종방향 안정성 해석

AU THI KIM LOAN,판호앙부,하기헌,박훈철 제어·로봇·시스템학회 2019 제어·로봇·시스템학회 논문지 Vol.25 No.11

Due to safety concerns, it is difficult for human beings to access a disaster area to rescue survivors. Even a robot may fail to conduct a rescue mission if it can use only one mode of transportation. A robot with multiple modes of trans¬portation may have a greater chance to successfully search for survivors within the golden time. In previous work to develop a dual-mode mobile robot, we introduced a jumping robot assisted by flapping wings called Jump-flapper. The robot was equipped with one driving motor and dual transmissions to operate a winching mechanism for elastic energy storage used for jumping and flapping mechanisms to provide additional thrust in the air immediately after jumping. In this paper, we analyzed the stability of Jump-flapper using a linearized equation of motion. With commercial software ANSYS-Fluent, computational fluid dynamics were used to compute stability derivatives included in the system matrix. The eigenvalue analysis finds that the robot eventually becomes unstable due to two unstable oscillatory modes. For a more accurate estimation of vertical jumping height, the drag of the robot body was included in the equation. Consequently, the equation of motion became non-linear and we used the Euler method to solve the non-linear equation. The estimated vertical jumping height agreed with the prediction by a simple model and with the measured height from our previous work.

Comparison of Aerodynamic Forces and Moments Calculated by Three-dimensional Unsteady Blade Element Theory and Computational Fluid Dynamics

Au, Loan Thi Kim,Phan, Hoang Vu,Park, Hoon Cheol Elsevier Science B.V., Amsterdam 2017 JOURNAL OF BIONICS ENGINEERING Vol.14 No.4

<P>In previous work, we modified blade element theory by implementing three-dimensional wing kinematics and modeled the unsteady aerodynamic effects by adding the added mass and rotational forces. This method is referred to as Unsteady Blade Element Theory (UBET). A comparison between UBET and Computational Fluid Dynamics (CFD) for flapping wings with high flapping frequencies (> 30 Hz) could not be found in literature survey. In this paper, UBET that considers the movement of pressure center in pitching-moment estimation was validated using the CFD method. We investigated three three-dimensional (3D) wing kinematics that produce negative, zero, and positive aerodynamic pitching moments. For all cases, the instantaneous aerodynamic forces and pitching moments estimated via UBET and CFD showed similar trends. The differences in average vertical forces and pitching moments about the center of gravity were about 10% and 12%, respectively. Therefore, UBET is proven to reasonably estimate the aerodynamic forces and pitching moment for flight dynamic study of FW-MAV. However, the differences in average wing drags and pitching moments about the feather axis were more than 20%. Since study of aerodynamic power requires reasonable estimation of wing drag and pitching moment about the feather axis, UBET needs further improvement for higher accuracy.</P>

An Exposition and Evaluation of Whitehead's Philosophical Theology : An evangelical response to process theology

Au, Peter Ying-Yuk Asian Center for Theological Studies and Mission 1986 ACTS 신학저널 Vol.2 No.-

Since the discovery of the quantum mechanics, magnetic and gravitational field theory, Darwin's evolutionary theory, Einstein's theory of relativity, the submolecular vibration and the superconductivity of the near-absolute zero temperature, the traditional Newtonian reality has been shattered. Reality is no longer considered as static corpuscular atoms bound by absolute space and time. These modern ecientific discoveries undermine the entier philosophy of science to account for the nature of things as they perceived it. Consequently, a new metaphysics is necessary to account for the modern science, human moral and religious experiences. Alfred North Whitehead was born at the opportune time to capture the desire of the age and apply the theories of the modern physics to the realm of reality. Thus he becomes and epitome of the inquiry into a new metaphysics. His discovery has a far-reaching implication in the areas of science, philosophy and religion. No scientist, philosopher and tehologian can afford to bypass Whitehead's metaphysics too lightly. whitehead's metaphysics openly challenges the theistic metaphysics and redefines the metaphysical attributes of God. The classical theistic metaphysical attributes of God are aseity, necessity, simplicity, infinity, eternity, purity, and unity. The classical theist conceives God as the necessary being which is uncaused and self-existing(aseity). Everything else in the world is a contingent being dependent upon this necessary being for its existence. Being necessary, God must be also a pure actuality without any potentiality to change. Likewise pure actuality has no parts or principle of division within Him, or He is a simple being. Similarly, he must be non-temporal and non-spatial, for time and space involve some kind of change. Furthermore, a pure actuality is unlimited, for potentiality is the principle of limitation. He must be eternal and infinite. All of the above metaphysical attributes of God are repudiated by the Whiteheadean metaphysics. In other words, the Whiteheadean metaphysics poses a serious challenge to the basic doctrine of orthodox faith, the doctrine of God. This study is an attempt to interact with the Whiteheadean metaphysics and epistemology. The purpose is to understand the system and be able to state it clearly and accurately. Having given the exposition of the system, the author will evaluate and citique it. First of all, we shall look into the development of the Whiteheaden metaphysics in its historical context.

Reconceptualizing Online Free Spaces: A Case Study of the Sunflower Movement

Au, Anson World Association for Triple Helix and Future Stra 2016 Journal of Contemporary Eastern Asia Vol.15 No.2

Using the Sunflower movement as a case study, this article seeks to articulate a theoretical framework to evaluate online "free spaces" as tools for political mobilization. To this end, this article conducts a thematic and content analysis of 151 posts on the official Facebook page of the Sunflower movement. Key results uncover four thematic functions among posts - expressive, informative, informative-support, and promotional - that overlap, in which the expressive theme prevails, and two thematic topics discussed by posts - damages by protesters and their ideology of freedom. I conclude that: (1) combining the logistic and thematic dimensions of posts enables a specific understanding of an online free space's political viability and anticipates the campaigns it will connect itself to; (2) the networked nature of the Sunflower movement page prompts the reconceptualization of (i) online free spaces as nodes through which various political campaigns and struggles are thematically connected by a political ideology; (ii) inactivity as a strategy where protest capital and followers accumulate to prepare and empower future mobilizations.

The role of pH in metal ion removal using coir dust and its modified extract resins

AU Israel,UM Eduok,E. Inam,Kyoung-Woong Kim 한국자원공학회 2012 Geosystem engineering Vol.15 No.4

The role of pH on metal ion adsorption by unmodified coir dust and its modified extract forms (namely carboxylated and sulphonated coir extract resins) was studied in a batch system. The zero point charge pH (pH pzc) of the adsorbents was determined and the results demonstrated that the amount of metal ions adsorbed by the adsorbents was dependent on pH(pzc). The adsorption of these metal ions by the adsorbent increased with increasing pH. The unmodified coir dust, being a lignocellulosic material, removed more metal ions than the modified coir extract resins derived from a tannin-polyhydroxy compound. Hydroxyl, carboxylic and sulphonic functional groups are responsible for the metal ion binding in these adsorbents,as revealed by infra-red spectroscopic analysis. Coir dust, carboxylated coir extract (CTR) and sulphonated coir extract resin (STR) are effective adsorbents for removal of metal ions from aqueous solution and industrial effluents/wastewater.

Chronic myeloid leukemia in Asia

Au, Wing Y.,Caguioa, Priscilla B.,Chuah, Charles,Hsu, Szu Chun,Jootar, Saengsuree,Kim, Dong-Wook,Kweon, Il-Young,O’Neil, William M.,Saikia, Tapan K.,Wang, Jianxiang Springer-Verlag 2009 INTERNATIONAL JOURNAL OF HEMATOLOGY Vol.89 No.1

Monitoring populations for DNA repair deficiency and for cancer susceptibility

Au.William W. 강원대학교 종합약학연구소 1996 약학연구 Vol.9 No.-

Ambient Vibration measurements and finite element modelling for the Hong Kong Ting Kau Bridge

Au, F.T.K.,Tham, L.G.,Lee, P.K.K.,Su, C.,Han, D.J.,Yan, Q.S.,Wong, K.Y. Techno-Press 2003 Structural Engineering and Mechanics, An Int'l Jou Vol.15 No.1

The Ting Kau Bridge in Hong Kong is a cable-stayed bridge comprising two main spans and two side spans. The bridge deck is supported by three towers, an end pier and an abutment. Each of the three towers consists of a single reinforced concrete mast which reduces its section in steps, and it is strengthened by transverse cables and struts in the transverse vertical plane. The bridge deck is supported by four inclined planes of cables emanating from anchorages at the tower tops. In view of the threat from typhoons, the dynamic behaviour of long-span cable-supported bridges in the region is always an important consideration in their design. This paper is devoted to the ambient vibration measurements of the bridge for evaluation of dynamic characteristics including the natural frequencies and mode shapes. It also describes the modelling of the bridge. A few finite element models are developed and calibrated to match with the field data and the results of subsequent structural health monitoring of the bridge.