• Structural Engineering and Mechanics
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• v.59 no.4
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• pp.719-737
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• 2016

The present study investigated the earthquake behavior of R/C structures considering the vertical earthquake motion with the help of a comparative study. For this aim, the linear time-history analyses of a high-rise R/C structure designed according to TSC-2007 requirements were conducted including and excluding the vertical earthquake motion. Earthquake records used in the analyses were selected based on the ratio of vertical peak acceleration to horizontal peak acceleration (V/H). The frequency-domain analyses of the earthquake records were also performed to compare the dominant frequency of the records with that of the structure. Based on the results obtained from the time-history analyses under the earthquake loading with (H+V) and without the vertical earthquake motion (H), the value of the overturning moment and the top-story vertical displacement were found to relatively increase when considering the vertical earthquake motion. The base shear force was also affected by this motion; however, its increase was lower compared to the overturning moment and the top-story vertical displacement. The other two parameters, the top-story lateral displacement and the top-story rotation angle, barely changed under H and H+V loading cases. Modal damping ratios and their variations in horizontal and vertical directions were also estimated using response acceleration records. No significant change in the horizontal damping ratio was observed whereas the vertical modal damping ratio noticeably increased under H+V loading. The results obtained from this study indicate that the desired structural earthquake performance cannot be provided under H+V loading due to the excessive increase in the overturning moment, and that the vertical damping ratio should be estimated considering the vertical earthquake motion.

• Tuberculosis and Respiratory Diseases
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• v.59 no.1
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• pp.104-108
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• 2005

A broncholith is a calcified mediastinal lymph node, which partially or completely erodes into the bronchial lumen, and is related to the late tissue response to healing of granulomatous pulmonary infections, most commonly histoplasmosis or tuberculosis. However, there have been a few reports on broncholithiasis caused by Aspergillus. We experienced a case of broncholithiasis caused by Aspergillus, with broncho-obstructive pneumonia and massive hemoptysis. A 39 year-old woman was admitted to our hospital with right middle lobar pneumonia. On the fourth day following admission, massive hemoptysis developed, so an emergent bronchial artery embolization was performed. On the ninth day following admission, a broncholith on the lateral segmental bronchus of the right middle lobe was found by bronchoscopy, which was proved to be Aspergillus hypae with calcification on histological examination. After the simple bronchoscopic removal of the broncholith and empirical antibiotic therapy, the patient recovered without any complications.

• Journal of the Earthquake Engineering Society of Korea
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• v.14 no.4
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• pp.23-28
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• 2010

This study evaluated the effect of vibration, level of lateral yielding strength, site conditions, ductility factor, strain-hardening ratio, and post-capping ratio of the strength limited bilinear SDF systems on the inelastic displacement ratio. The nonlinear response history analysis was conducted using 240 ground motions which were collected at the sites classified as site classes B, C, and D according to the NEHRP. To account for the P-$\Delta$ effects, this study considered negative stiffness ratios ranging from -0.1 to -0.5 of elastic stiffness. Four different damping ratios are used: 2, 5, 10, and 20%. From this study, an equation of inelastic displacement ratio was proposed using nonlinear regression analysis.

• Journal of Periodontal and Implant Science
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• v.33 no.2
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• pp.215-223
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• 2003

The main goal of periodontal treatment is the long-term maintenance of teeth. Periodic maintenance program is need to prevent periodontal disease and maintain healthy periodontium. Hirschfeld and Wasserman(1978) studied 600 treated periodontal patients. This study categorized periodontal patients using well-maintained, downhill, extreme downhill groups. The purpose of our study is to evaluate effect of periodontal treatment and analyse tooth loss after periodontal treatment using this classification. The study population of j9 patients had been treated and maintained for mean 5.8 years. All patients were on a periodic maintenance program at 2-, 3-, 4, or 6-month intends. The avenge age of the patients at the time of original therapy was 49.6 years. To analyse tooth loss, modified classification was used on the basis of response to therapy using by Hirschfeld and Wasserman in 1978. The results were as follows : 1. 59 treated patients were lost mean 1.42 teeth per patient for 5.8 years of maintenance period. 2. Maxillary first molars were most frequently lost but mandibular lateral incisors were lost no tooth during maintenance period. 3. Tooth mortality received surgical treatment had similar to received nonsurgical treatment. 4. Tooth loss was more frequent in maxillary teeth than mandibular teeth, and posterior teeth than anterior teeth, and more frequent tendency in male than female.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.9
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• pp.1931-1942
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• 2002

In this paper a formulation of robust optimization is presented and illustrated by a design example of vibratory micro gyroscopes in order to reduce the effect of variations due to uncertainties in MEMS fabrication processes. For the vibratory micro gyroscope considered it is important to match the resonance frequencies of the vertical (sensing) and lateral (driving) modes as close as possible to attain a high sensing sensitivity. A deterministic optimization in which the difference of both the sensing and driving natural frequencies is minimized as an objective function results in highly enhanced performance but apt to be very sensitive to fabrication errors. The formulation proposed is to attain robustness of the performance by including the sensitivity of the response with respect to uncertain variables as a term of objective function to be minimized. This formulation is simple and practically applicable since no detail statistical information on fabrication errors is required. The geometric variables, beam width, length and thickness of vibratory micro gyroscopes are adopted as design variables and at the same time considered as uncertain variables because here occur the fabrication errors. A robustness test in terms of a percentage yield by using the Monte Carlo simulation has shown that the robust optimum produces twice more acceptable designs than the deterministic optimum. Improvement of robustness becomes bigger as the amount of fabrication errors is assumed larger. Considering that the magnitude of fabrication errors and uncertainties in a MEMS structure are comparatively large, the present method is illustrated to be a viable approach for a robust MEMS design.

• The Journal of Korean Medicine
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• v.22 no.2
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• pp.31-40
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• 2001

This experimental studies was to investigate location of labeled neurons in CNS following injection of pseudorabies virus(PRV), Bartha strain, into the uterus and Sanyinjiao(Sp6) of rats. After survival times of 4-5 days following the injection of PRV, the rats were perfused, and their brain and spinal cord were frozen sectioned($30\mu\textrm{m}$). These sections were stained by PRV immunohistochemical staining methods, and observed with light microscope. The results were as follows: 1. In the spinal cord, overlap areas of PRV labeled neurons projecting to uterus and Sp6 were observed in lamina VII, IX and X areas of cervical segments. In thoracic segments, overlap areas were observed in lamina IV, VII, X and intermediolateral n.. In lumbar segments, overlap area of PRV labeled neurons were observed in lamina I, V-VII, IX, X and intermediolateral n.. In sacral segments, overlap areas of PRY labeled neurons were observed in lamina N, V, VII, X and sacral parasympathetic n.. 2. In the brain, overlap areas of PR V labeled neurons projecting to the uterus and Sp6 were observed in lateral paragigantocellular n., rostroventrolateral reticular n., raphe obscurus n., raphe pallidus n., raphe magnus n., locus coeruleus n., Barrington's n., A5 cell group, central gray n., paraventricular hypothalamic n. and arcuate n. This results suggest that overlap areas of PRV labeled neurons of the spinal cord projecting to the uterus and Sp6 might be the first-order neurons related to the viscera-somatic sensory and sympathetic preganglionic neurons. PRV labeled neurons of the brain may be the second and third-order neurons response to the movement of smooth muscle of uterus. These PRV labeled neurons may be central autonomic center related to the integration and modulation of reflex control linked to the sensory and motor system monitoring the internal environment. These overlap areas of spinal cord and brainmay be related to autonomic centers related to regulation of uterus.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.8
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• pp.752-760
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• 2011

In tilting pad bearing design process, the selection of the proper configuration type of either a load-between-pad(LBP) or load-on-pad(LOP) as well as preload and pivot offset conditions is to be carefully considered. Also the bearing needs to be designed in order to be suited for the rotor-bearing system and operating condition. In this paper, it is observed that the dynamic characteristics in a five pad tilting pad bearing for the LBP and the LOP configurations are influenced by the variation of preload and pivot offset. In this context, rotor dynamic analysis of the 5 MW industrial gas turbine supported by the tilting pad bearing at the front and roller bearing at the rear is carried out based on the dynamic coefficients of the tilting pad bearing investigated. The result shows that two rigid body critical modes experience various changes according to the influence of the tilting pad bearing uniquely applied to one side of this machine. Mainly, the second critical speed, the rigid body mode of conical shape with high whirling in the tilting pad bearing, is significantly changed by preload and pivot offset regardless of the LBP and LOP configurations. And, the first critical mode, the rigid body mode of conical shape with high whirling in the roller bearing, is sensitively affected by preload applied to the LOP configuration and by its asymmetric dynamic properties.

• Steel and Composite Structures
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• v.16 no.5
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• pp.491-506
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• 2014

Buckling-restrained braces (BRBs) have excellent hysteretic behavior while buckling-restrained braced frames (BRBFs) are susceptible to residual lateral deformations. To address this drawback, a novel self-centering (SC) BRB with Basalt fiber reinforced polymer (BFRP) composite tendons is presented in this work. The configuration and mechanics of proposed BFRP-SC-BRBs are first discussed. Then an 1840-mm-long BFRP-SC-BRB specimen is fabricated and tested to verify its hysteric and self-centering performance. The tested specimen has an expected flag-shaped hysteresis character, showing a distinct self-centering tendency. During the test, the residual deformation of the specimen is only about 0.6 mm. The gap between anchorage plates and welding ends of bracing tubes performs as expected with the maximum opening value 6 mm when brace is in compression. The OpenSEES software is employed to conduct numerical analysis. Experiment results are used to validate the modeling methodology. Then the proposed numerical model is used to evaluate the influence of initial prestress, tendon diameter and core plate thickness on the performance of BFRP-SC-BRBs. Results show that both the increase of initial prestress and tendon diameters can obviously improve the self-centering effect of BFRP-SC-BRBs. With the increase of core plate thickness, the energy dissipation is improved while the residual deformation is generated when the core plate strength exceeds initial prestress force.

• Journal of the Earthquake Engineering Society of Korea
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• v.7 no.6
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• pp.81-91
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• 2003

Recently, many high-rise reinforced concrete(RC) bearing-wall structures of multiple uses have been constructed, which have the irregularities of weak(or soft) story and torsion at the lower stories simultaneously. The study stated herein was performed to investigate seismic performance of such a high-rise RC structure through a series of shaking table tests of a 1: 12 model. Based on the observations of the test results, the conclusions are drawn as follows: 1) Accidental torsion due to the uncertainty on the properties of structure can be reasonably predicted by using the dynamic analysis than by using lateral force procedure. 2) The mode coupled by translation and torsion induced the overturning moments not only in the direction of excitations but also in the perpendicular direction: The axial forces in columns due to this transverse overturning moment cannot be adequately predicted using the existing mode analysis technique, and 3) the hysteretic curve and the strength diagram between base shear and torque(BST) clearly reveal the predominant mode of vibrations and the failure mode.

• Journal of the Earthquake Engineering Society of Korea
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• v.15 no.6
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• pp.67-80
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• 2011

This paper presents the results of shaking table tests on a 1:5 scale 10-story R.C. wall-type residential building model. The following conclusions are drawn based on the test results. (1) The model responded linear elastically under the excitations simulating an earthquake with a return period of 50 years, and showed a nonlinear response under the excitations simulating the design earthquake of Korea. (2) The model showed a significant strength drop under the maximum considered earthquake, with a return period of 2400 years. (3) The major portion of the resistance to lateral inertia forces came from the walls used for the elevator and stair case. (4) Finally, the damage and failure modes appear to be due to the flexural behavior of walls and slabs. A significant deterioration of stiffness and an elongation of the fundamental periods were observed under increased earthquake excitations.