• Earthquakes and Structures
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• v.13 no.1
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• pp.9-15
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• 2017

In this paper, the influence of the rotational component, about a vertical axis, of earthquake ground motion on the response of building structures subjected to seismic action is considered. The torsional component of ground motion is generated from the records of translational components. Torsional component of ground motion is then, together with translational components, applied in numerical linear dynamic analysis of different reinforced concrete framed structure of three stories buildings. In total, more than 40 numerical models were created and analyzed. The obtained results show clearly the dependence of the effects of the torsional seismic component on structural system and soil properties. Thus, the current approach in seismic codes of accounting for the effects of accidental torsion due to the torsional ground motion, by shifting the center of mass, should be reevaluated.

• Communications for Statistical Applications and Methods
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• v.6 no.1
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• pp.1-10
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• 1999

When the component proportions in mixture experiments are restricted by lower and upper bounds multicollinearity appears all too frequently. The ridge regression can be used to stabilize the coefficient estimates in the fitted model. I propose a graphical method for evaluating the mixture component effects of ridge regression estimator with respect to the prediction variance and the prediction bias.

• Smart Structures and Systems
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• v.20 no.6
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• pp.641-656
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• 2017

The effects of vertical component of earthquakes on torsional amplification due to mass eccentricity in seismic responses of base-isolated structures subjected to near-field ground motions are studied in this paper. 3-, 6- and 9-story superstructures and aspect ratios of 1, 2 and 3 have been modeled as steel special moment frames mounted on Triple Concave Friction Pendulum (TCFP) bearings considering different period and damping ratios. Three-dimensional linear superstructures resting on nonlinear isolators are subjected to both 2 and 3 component near-field ground motions. Effects of mass eccentricity and vertical component of 25 near-field earthquakes on the seismic responses including maximum isolator displacement and base shear as well as peak superstructure acceleration are studied. The results indicate that the effect of vertical component on the responses of asymmetric structures, especially on the base shear is significant. Therefore, it can be claimed that in the absence of the vertical component, mass eccentricity has a little effect on the base shear increase. Additionally, the impact of this component on acceleration is remarkable so the roof acceleration of a nine-story structure has been increased 1.67 times, compared to the case that the structure is subjected to only horizontal components of earthquakes.

• Earthquakes and Structures
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• v.7 no.1
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• pp.83-99
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• 2014

This study is devoted to estimate higher-mode effects for multi-story structures with considering soil-structure interaction subjected to decomposed parts of near-fault ground motions. The soil beneath the super-structure is simulated based on the Cone model concept. Two-dimensional structural models of 5, 15, and 25-story shear buildings are idealized by using nonlinear stick models. The ratio of base shears for the soil-MDOF structure system to those obtained from the equivalent soil-SDOF structure system is selected as an estimator to quantify the higher-mode effects. The results demonstrate that the trend of higher-mode effects is regular for pulse component and has a descending variation with respect to the pulse period, whereas an erratic pattern is obtained for high-frequency component. Moreover, the effect of pulse component on higher modes is more significant than high-frequency part for very short-period pulses and as the pulse period increases this phenomenon becomes vice-versa. SSI mechanism increases the higher-mode effects for both pulse and high-frequency components and slenderizing the super-structure amplifies such effects. Furthermore, for low story ductility ranges, increasing nonlinearity level leads to intensify the higher-mode effects; however, for high story ductility, such effects mitigates.

• Journal of the Korean Statistical Society
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• v.28 no.4
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• pp.489-501
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• 1999

In this paper, we consider the panel data regression model in which the disturbances have nested error component. We derive a Lagrange Multiplier(LM) test which is jointly testing for the presence of random individual effects and nested effects under the normality assumption of the disturbances. This test extends the earlier work of Breusch and Pagan(1980) and Baltagi and Li(1991). Further, it is shown that this LM test has the same asymptotic distribution without normality assumption of the disturbances.

• Journal of Korea Foundry Society
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• v.24 no.4
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• pp.202-208
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• 2004

Effects of Co addition on sliding wear properties of multi-component white cast iron were investigated. The microstructures of multi-component white cast iron containing from 0%Co to 10%Co exhibited little difference. However, the hardness increased with an increase of the Co content. Increasing the Co content, wear properties were improved and the iron oxide on worn surface was increased in the low sliding speed range of the steady-state wear region. Hence, Co addition was effective to improve the wear properties of multi-component white cast iron by accelerating the corrosive wear as well as the enhancement effect of hardness.

• The Korean Journal of Pharmacology
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• v.10 no.2
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• pp.13-23
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• 1974

Results of an experiment on the general behavior of rats in order to explore the possible pharmacological actions of Panax Ginseng upon the central nervous system can be summarized as follows: 1) The rats treated with Ginseng-saponin intraperitoneally with the doses of 50 or 100 mg/kg show the decreased sleeping component and increase in lying and grooming component and walking and rearing component of general behavior. 2) There are no difference between control group and saline treated group in pattern of general behavior components. 3) In the Ginseng-saponin treated groups, the amphetamine stimulated walking and rearing component of genenarl behavior are reduced but lying and grooming component are elevated. 4) Ginseng-saponin shows very low acute toxicity in mice. The $LD_{50}$ in mice of 24 hours after intraperitoneal injection was 795 mg/kg. From the above findings, it is to suggest that the Ginseng saponin might stimulate the central nervous system but its mode of action appears to be different from that of amphetamine. And the effects of Ginseng saponin may be varied depending on various experimental situation or condition of animals.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.6
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• pp.1769-1776
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• 2004

The aim of this study was to find out the effects of the Yukmijihwangtang on transcription activity of Genes related to Bone Morphogenesis. For this purpose, experiments were performed to compare the polyphosphate contents of Yukmijihwangtang and its component herbs, and to verify their Effects on transcription activity of Genes related to Bone Morphogenesis. We know that Yukmijihwangtang and its component herbs have adequate amount of polyphosphate contents and have effects on transcription activity of Genes such as BMP1A, BMP2B, OTN, MGP, COL. In the conclusion, Yukmijihwangtang and its component herbs are strongly believed to have effectiveness on bone morphogenesis.

• KIEE International Transactions on Power Engineering
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• v.5A no.4
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• pp.322-330
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• 2005

This paper proposes methods to incorporate station related aging failures in composite system reliability assessment. Aging failures of station components, such as circuit breakers and bus bars, are a major concern in composite power system planning and operation as an increasing number of station components approach the wear-out phase. This paper presents probabilistic models for circuit breakers involving aging failures and relevant evaluation techniques to examine the effects of station related aging outages. The technique developed to incorporate station related aging failures are illustrated by application to a small composite test system. The paper illustrates the effects of circuit breaker aging outages on bulk system reliability evaluation and examines the relative effects of variations in component age. System sensitivity analysis is illustrated by varying selected component parameters. The results show the implications of including component aging failure considerations in the overall analysis of a composite system.

• Journal of Korean Elementary Science Education
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• v.32 no.4
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• pp.379-392
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• 2013

The purpose of this study was to examine the effects of animation-based instruction on elementary students' level of understanding and interest on a plant's structure and function, using "Magic School Bus(Joanna Cole, Bruce Degen, 1986)". The understanding and interest measurements were administered to 99 fifth grade students at a elementary school located in Seoul. The study examined the changes in understanding and interest through pre-test and post-test of the two groups. Intensive interviews were conducted to find factors that enhance understanding and interest. Three key findings were revealed from the results. First, the animation-based instruction enhanced the level of understanding in the experimental group compared to the control group. Second, animation-based instruction made high-achieving students enhance their interest in topic component and attitude component. And, animation-based instruction did not led low-achieving students to increase their interest in the topic component and attitude component. We suggest that animation-based instruction positively influences students' understanding, but its effects on students' interest are dependent on their conceptual understanding of the topic.