• Biomolecules & Therapeutics
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• v.15 no.4
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• pp.245-251
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• 2007

The object of this study was to evaluate the single dose toxicity of Kong-Jin-Dan (KJD), a polyherbal formula in male and female mice. KJD was administered to female and male ICR mice as an oral dose of 2000, 1000 and 500 mg/kg (body wt.) according to the recommendation of KFDA Guidelines. Animals were monitored for the mortality and changes in body weight, clinical signs and gross observation during 14 days after dosing, upon necropsy, organ weight and histopathology of 12 principle organs were examined. As results, we could not find any mortality, clinical signs, and changes in the body and organ weight except for increases of lymphoid organ weights in KJD-dosing groups. These increases of lymphoid organ weights considered that related to the immune modulate effect of KJD not toxicological signs. In addition, no KJD-treatment related abnormal gross findings and changes in histopathology of principle organs were detected except for some sporadic accidental findings. The results obtained in this study suggest that the KJD does not cause any toxicological signs. The $LD_{50}$ and approximate LD of KJD extracts in both female and male mice were considered as over 2000 mg/kg.

• Structural Engineering and Mechanics
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• v.63 no.2
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• pp.161-169
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• 2017

In this paper, using consistent couple stress theory and Hamilton's principle, the free vibration analysis of Euler-Bernoulli nano-beams made of bi-directional functionally graded materials (BDFGMs) with small scale effects are investigated. To the best of the researchers' knowledge, in the literature, there is no study carried out into consistent couple-stress theory for free vibration analysis of BDFGM nanostructures with arbitrary functions. In addition, in order to obtain small scale effects, the consistent couple-stress theory is also applied. These models can degenerate into the classical models if the material length scale parameter is taken to be zero. In this theory, the couple-tensor is skew-symmetric by adopting the skew-symmetric part of the rotation gradients as the curvature tensor. The material properties except Poisson's ratio are assumed to be graded in both axial and thickness directions, which it can vary according to an arbitrary function. The governing equations are obtained using the concept of Hamilton principle. Generalized differential quadrature method (GDQM) is used to solve the governing equations for various boundary conditions to obtain the natural frequencies of BDFG nano-beam. At the end, some numerical results are presented to study the effects of material length scale parameter, and inhomogeneity constant on natural frequency.

• Review of Korean Society for Internet Information
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• v.14 no.3
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• pp.52-57
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• 2013

Information and Communication Technologies(ICTs) have substantially enlarged both the opportunities to realize one's human rights but have also resulted in the emergence of new challenges. ICTs are so deeply embedded and cental to almost all aspects of human activity. And ICTs are assuming an increasingly central role in all aspects of human and societal development across the world. But this is especially true of the right to privacy, which faces challenges such as profiling and data mining for public(including national security) and private purposes. ICTs access is a fundamental right for all humans in the information age. So we have need for regulation based on human rights in the digital age. And governments have a responsibility to protect individuals against violations of human rights and data protection by public authorities, but also by private entities. In addition, internet governance and multi-stakeholder principle have to be stressed on all of the internet issues because internet governance is included in the principle of democracy which have bottom-up communication and equality. So it is very importance that Internet Governance Forum is the space for a meaningful discussion on public policy issues relating to the internet.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.4
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• pp.897-902
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• 2005

Internal deficiency of vital Qi is origination of cancer and root cause of its development from the viewpoint of traditional Chinese medicine(TCM). For about 40 years, China has developed a combined system of TCM and Western medical system in treatment of cancers, laying stress on the therapeutic principle of strengthening the body resistance and restoring normal functioning of the body to consolidate the constitution (Fu Zheng Pei Ben). According to the results of the latest clinical and experimental studies, Chinese medicine not only increases curative effectiveness, but also reduces the side effect caused by the toxic, radio and chemical treatment of cancer cases in the western medical system as well as various complications. Long-term taking Chinese herbal medicine prevents recurrence and metastasis of tumor, and heightens long-term curative effectiveness after western medical treatments. It also helps to relieve symptoms, improve the quality of life, and prolong life of terminal cancer patients who have already lost opportunities of western medical treatments. In addition, it can prevent and cure premonitory symptoms of cancer.

• Food Science and Biotechnology
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• v.16 no.4
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• pp.610-614
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• 2007

Dynamic rheological properties of honeys with invert sugar at different mixing ratios of honey and invert sugar (10/0, 812, and 6/4 ratios) were evaluated at various low temperatures (-15, -10, -5, and $0^{\circ}C$) using a controlled stress rheometer for small-deformation oscillatory measurements. Honey-invert sugar mixtures displayed a liquid-like behavior, with loss modulus (G") predominating over storage modulus (G') (G">>G'), showing the high dependence on frequency (${\omega}$). The magnitudes of G' and G" increased with a decrease in temperature while their predominant increases were noticed at -10 and $-15^{\circ}C$. The greater tan ${\delta}$ values were found at higher temperature and ratio of honey to invert sugar, indicating that the honey samples at subzero temperatures become more viscous with increased ratio of honey to invert sugar and temperature. The time-temperature superposition (TTS) principle was used to bring G" values at various temperatures together into a single master curve. The TTS principle was suitable for the honey samples in the liquid-like state. The progress of viscous property (G") was also described well by the Arrhenius equation with high determination coefficients ($R^2=0.99$). Dynamic rheological properties of honey samples seem to be greatly influenced by the addition of invert sugar.

• Hwankyungkyoyuk
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• v.11 no.2
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• pp.238-251
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• 1998

Environmental education, which has been thought as the most fundamental solution to environmental problems, should be performed not only in school but also in home and society with a long-term plan. In line with this, environmental-friendly attitude in daily life should be achieved by the perception of the vital environmental principle-new understanding of relation between nature and human being. It is in the city park that children in urban area, who has little opportunity to contact nature, have rather easier access to nature and realize the principle. Despite such great potential, the city park in Korea has not played its pivotal role because of lack of both facilities and activities. In addition, existing studies on this issue are not satisfactory. Therefore, this study is aimed at analyzing and evaluating city parks' environmental education function, potential and problems according to their types, then offering practical reform measures and programs in order to make students better understand the parks as an everyday natural experience spot. These plans are not based on full-scale revision, instead focuses on optimizing potential of existing natural environment and parks. Additionally, activities to experience various nature are included in the study. The value of city park is not decided by the park itself, but by its relationship with visitors. Environmental education function of city park is not confined to building up facilities and providing programs. It also should be complemented and improved, reflecting visitors' opinions and evaluation of environmental education.

• Steel and Composite Structures
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• v.10 no.3
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• pp.245-260
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• 2010

In this paper, experimental and theoretical investigations on the response and collapse of 310 stainless steel tubes with different diameter-to-thickness ratios subjected to cyclic bending are discussed. The tube-bending device and curvature-ovalization measurement apparatus were used to conduct the experiment. The endochronic theory combined with the principle of virtual work and finite element software, ANSYS, were used to simulate the moment-curvature and ovalization-curvature relationships. It is shown that although the two methods lead to good simulation of the moment-curvature relationship, the endochronic theory combined with the principle of virtual work has the better simulation of the ovalization-curvature response when compared with experimental data and the simulation by ANSYS. In addition, the theoretical formulations proposed by Kyriakides and Shaw (1987) and Lee et al. (2001) were used to simulate the controlled curvature-number of cycles to produce buckling relationship. It is shown that the theoretical formulations effectively simulate the experimental data.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.99-102
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• 2003

The electronic structure of ${\beta}-MnO_2$ having impurities in the site of Mn was theoretically investigated by $DV-X_{\alpha}$ (the discrete variation $X{\alpha}$) method, which is a sort of the first principle molecular orbital method using Hatre-Fock-Slater approximation. The used cluster model was $[Mn_{14}MO_{56}]^{-52}$ (M = transient metals). Madelung potential and spin polarization were considered for more exact calculations. As results of calculations, the energy levels of all electron included in the model were obtained. The energy band gap and positions of impurity levies were discussed in association with impurity 34 orbital that seriously affect electrical properties of $MnO_2$. It was shown that the energy band gap decreased with the increase of the atomic number of transient metal impurity.

• Journal of the Korea Society of Computer and Information
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• v.24 no.5
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• pp.171-177
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• 2019

In this paper, we analyze the current phenomenon of child abuse crimes based on the information gathered by the National Child Protection Agency. The purpose of this paper is to diagnose the seriousness of child abuse by biological parents based on the analyzed information and propose measures against it. Comprehensive and integrated measures are needed for child abuse committed by biological parents due to abuse concealment, continuity of damage, and inactive national intervention by considering punishment on attackers through national intervention, fundamental in-depth psychological counseling, therapeutic care, promoting recovery of victims, and ultimately continuous and regular management and monitoring as a long-terms measure. To do so, developing customized and individual educational programs and make them obligations can be first presented to identify child abuse in advance and build up preventive systems based on the principle of family preservation. In addition, problems should be addressed at a fundamental level by performing various and active therapeutic treatments such as psychological treatment, mental treatment, or drug treatment gradually and through phases for biological parents who commit child abuse and contributing to recovering the relationship. Furthermore, proper protection and treatment service should be provided to children victimized by abuse by extending professional children care facilities and adopting the professional family commission system as measures by separating family.

• Advances in nano research
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• v.14 no.2
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• pp.141-154
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• 2023

Effects of viscoelastic foundation on vibration of curved-beam structure with clamped and simply-supported boundary conditions is investigated in this study. In doing so, a micro-scale laminate composite beam with two piezoelectric face layer with a carbon nanotube reinforces composite core is considered. The whole beam structure is laid on a viscoelastic substrate which normally occurred in actual conditions. Due to small scale of the structure non-classical elasticity theory provided more accurate results. Therefore, nonlocal strain gradient theory is employed here to capture both nano-scale effects on carbon nanotubes and microscale effects because of overall scale of the structure. Equivalent homogenous properties of the composite core is obtained using Halpin-Tsai equation. The equations of motion is derived considering energy terms of the beam and variational principle in minimizing total energy. The boundary condition is assumed to be clamped at one end and simply supported at the other end. Due to nonlinear terms in the equations of motion, semi-analytical method of general differential quadrature method is engaged to solve the equations. In addition, due to complexity in developing and solving equations of motion of arches, an artificial neural network is design and implemented to capture effects of different parameters on the inplane vibration of sandwich arches. At the end, effects of several parameters including nonlocal and gradient parameters, geometrical aspect ratios and substrate constants of the structure on the natural frequency and amplitude is derived. It is observed that increasing nonlocal and gradient parameters have contradictory effects of the amplitude and frequency of vibration of the laminate beam.