• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.2
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• pp.128-134
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• 2008

The variable speed engine generator set is interested for an isolated power system due to reduced fuel consumption and less emission. However, because of sluggish dynamic behavior of the internal combustion engine the power quality would be degraded during the sudden load power surge, where the power required by the load is not available by the engine due to the reduced engine speed. An isolated power system based on variable speed engine with a super-capacitor bank can improve dynamic characteristics under such a sudden load change, and power quality, fuel consumption, and pollutants can be improved remarkably. Also, it is verified by the computer simulation that the inverter of 3phase-4leg is compatible to the isolated power system with unbalanced load. In this paper, the feasibility of the system has been verified based on a 26kw commercial diesel engine system.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.1 no.1
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• pp.25-38
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• 1988

In order to evaluate the relationship between the bibliographical and clinical effectiveness of Socheongryoungtang, this study was carried out to investigate the effects of Socheongryoungtang on the respiratory system, cardiovascular system and isolated organ in the experimental animals. The following results of Socheongryoungtang were obtained; 1. The relaxing effect on the muscular contraction of isolated ileum induced by acetylcholine chloride, barium chloride and histamine${\cdot}$2HCl was recognized in mice, rat and guinea-pig. 2. The effect of direct vasodilatation was noted in rabbit. 3. The effect of hypotensor was recognized in rabbit. 4. The antihistamine effect was noted on both isolated ileum and tracheal strip-chain in guinea-pig. 5. The inhibitory effect on gastric ulcer induced by histamine${\cdot}$2HCl was noted in rat. 6. The inhibitory effect on vascular permeability was revealed in mice. 7. The antitussive effect was recognized in both dog and cat. 8. The effect of expectorant was recognized in rabbit. According to the above results, we has recognized that Socheongryoungtang has good efficacy for bibliographical and clinical diseases caused from respiratory system (especially allergic rhinitis etc.), cardiovascular system and digestive system.

• Structural Engineering and Mechanics
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• v.46 no.5
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• pp.645-672
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• 2013

The differential settlements and rotations among footings cannot be avoided when the frame-footing-soil system is subjected to seismic/dynamic loading. Also, there may be a situation where column(s) of a building are located near adjoining property line causes eccentric loading on foundation system. The strap beams may be provided to control the rotation of the footings within permissible limits caused due to such eccentric loading. In the present work, the seismic interaction analysis of a three-bay three-storey, space frame-footing-strap beam-soil system is carried out to investigate the interaction behavior using finite element software (ANSYS). The RCC structure and their foundation are assumed to behave in linear manner while the supporting soil mass is treated as nonlinear elastic material. The seismic interaction analyses of space frame-isolated footing-soil and space frame-strap footing-soil systems are carried out to evaluate the forces in the columns. The results indicate that the bending moments of very high magnitude are induced at column bases resting on eccentric footing of frame-isolated footing-soil interaction system. However, use of strap beams controls these moments quite effectively. The soil-structure interaction effect causes significant redistribution of column forces compared to non-interaction analysis. The axial forces in the columns are distributed more uniformly when the interaction effects are considered in the analysis.

• Earthquakes and Structures
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• v.6 no.1
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• pp.111-125
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• 2014

Multiple level performance of seismically isolated elevated storage tank isolated with multi-phase friction pendulum bearing is investigated under totally 60 records developed for multiple level seismic hazard analysis (SLE, DBE and MCE). Mathematical formulations involving complex time history analysis have been proposed for analysis of typical storage tank by multi-phase friction pendulum bearing. Multi-phase friction pendulum bearing represent a new generation of adaptive friction isolation system to control super-structure demand in different hazard levels. This isolator incorporates four concave surfaces and three independent pendulum mechanisms. Pendulum stages can be set to address specific response criteria for moderate, severe and very severe events. The advantages of a Triple Pendulum Bearing for seismic isolation of elevated storage tanks are explored. To study seismic performance of isolated elevated storage tank with multi-phase friction pendulum, analytical simulations were performed with different friction coefficients, pendulum radii and slider displacement capacities.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.7-9
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• 1988

K-means iteration method is generally used for creating the templates in speaker-independent isolated-word recognition system. In this paper the initialization method of initial centers is proposed. The concepts are sorting and trace segmentation. All the tokens are sorted and segmented by trace segmentation so that initial centers are decided. The performance of this method is evaluated by isolated-word recognition of Korean digits. The highest recognition rate is 97.6%.

• Journal of Pharmaceutical Investigation
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• v.10 no.1
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• pp.1-3
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• 1980

The model of an isolated organ system has been developed to simulate the kinetic behavior of drug levels in an acting organ or site. The model is developed from basic considerations of drug distribution with hemodynamical and pharmacokinetical meanings. Model: It is considered a situation in which non-metabolic drug substance is injected into the arterial inflow of an isolated organ at constant rate. The volume of distribution and the concentration of drug in the venous outflow can be mathematically expressed as a function of time.

• The Journal of Internal Korean Medicine
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• v.13 no.1
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• pp.70-79
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• 1992

This study was carried out to investigate the effect of Yeemosan extract on the contractile force of the isolated guinea pig trachea smooth muscle and elucidate its mechanism. The results were obtained as follows: 1. The contractile response of the trachea smooth muscle of isolated guinea pig to acetylcholine was significantly inhibited by Yeemosan. 2. The contractile response of the trachea smooth muscle of isolated guinea pig pretreated propranolol was significantly inhibited by Yeemosan. 3. Effects of Yeemosan extract on the contractile response of the isolated guineapig trachea smooth muscle pretreated methylene blue was not significant. 4. The contractile response of the trachea smooth muscle of isolated guinea pig to prostaglandin $F2{\alpha)$ was significantly inhibited by Yeemosan. 5. Effects of prostaglandin $F2{\alpha)$ on the contractile response of the isolated guinea pig trachea smooth muscle pretreated Yeemosan was not significant. According to the above results. it was suggested that the contractile response mechanism of the guinea pig trachea smooth muscle to Yeemosan was related to sympathetic nervous system receptor and other mechanism should have further study.

• Structural Engineering and Mechanics
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• v.23 no.5
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• pp.543-562
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• 2006

Base isolation technology has been accepted as a feasible and attractive way in improving seismic resistance of structures. The seismic design of new seismically isolated structures is mainly governed by the Uniform Building Code (UBC-97) published by the International Conference of Building Officials. In the UBC code, the distribution formula of the inertial (or lateral) forces leads to an inverted triangular shape in the vertical direction. It has been found to be too conservative for most isolated structures through experimental, computational and real earthquake examinations. In this paper, four simple and reasonable design formulae, based on the first mode of the base-isolated structures, for the lateral force distribution on isolated structures have been validated by a multiple-bay three-story base-isolated steel structure tested on the shaking table. Moreover, to obtain more accurate results for base-isolated structures in which higher mode contributions are more likely expected during earthquakes, another four inertial force distribution formulae are also proposed to include higher mode effects. Besides the experimental verification through shaking table tests, the vertical distributions of peak accelerations computed by the proposed design formulae are in good agreement with the recorded floor accelerations of the USC University Hospital during the Northridge earthquake.

• Earthquakes and Structures
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• v.13 no.6
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• pp.561-572
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• 2017

Seismic base isolation has been accepted as one of the most popular design procedures to protect important structures against earthquakes. However, due to lack of information and experimental data the application of base isolation is quite limited to nuclear power plant (NPP) industry. Moreover, the effects of inelastic behavior of soil beneath base-isolated NPP have raised questions to the effectiveness of isolation device. This study applies the wavelet analysis to investigate the effects of soil-structure interaction (SSI) on the seismic response of a base-isolated NPP structure. To evaluate the SSI effects, the NPP structure is modelled as a lumped mass stick model and combined with a soil model using the concept of cone models. The lead rubber bearing (LRB) base isolator is used to adopt the base isolation system. The shear wave velocity of soil is varied to reflect the real rock site conditions of structure. The comparison between seismic performance of isolated structure and non-isolated structure has drawn. The results show that the wavelet analysis proves to be an efficient tool to evaluate the SSI effects on the seismic response of base-isolated structure and the seismic performance of base-isolated NPP is not sensitive to the effects in this case.

• Earthquakes and Structures
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• v.13 no.2
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• pp.119-130
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• 2017

This paper presents a numerical investigation on the seismic behavior of isolated bridges with supplemental viscous damping. Usually very large displacements make seismic isolation an unfeasible solution due to boundary conditions, especially in case of existing bridges or high risk seismic regions. First, a suggested optimal design procedure is introduced, then seismic performance of three real bridges with different isolation systems and damping levels is investigated. Each bridge is studied in four different configurations: simply supported (SSB), isolated with 10% damping (IB), isolated with 30% damping (LRB) and isolated with optimal supplemental damping ratio (IDB). Two of the case studies are investigated under spectrum compatible far-field ground motions, while the third one is subjected to near-fault strong motions. With respect to different design strategies proposed by other authors, results of the analysis demonstrated that an isolated bridge equipped with HDLRBs and a total equivalent damping ratio of 70% represents a very effective design solution. Thanks to confirmed effective performance in terms of base shear mitigation and displacement reduction under both far field and near fault ground motions, as well as for both simply supported and continuous bridges, the suggested control system provides robustness and reliability in terms of seismic performance also resulting cost effective.