• Journal of the Korean Society for Railway
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• v.10 no.5
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• pp.607-612
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• 2007

In this paper, operation mode of train was divided into powering, coasting, and braking and rail wear phenomenon has been done comparative analysis by each section. Data of train velocity is transferred to acceleration and deceleration from ATO Logging data. Amount of rail wear has been done comparative analysis by traction force of acceleration and braking force of deceleration and a plan for management of track irregularity is come up with by the result of the analysis.

• Journal of the Korean Society for Railway
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• v.10 no.5
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• pp.626-631
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• 2007

Technical requirements associated with derailment to ensure running safety of train are discussed. By using estimated derailment coefficient ratio, interaction of various parameters such as operation velocity, curve radius, cant, track irregularity, suspension stiffness and static wheel load ratio are analyzed to enhance derailment safety. Sensitivity analysis in terms of pattern and passage speed of curve is performed by using rolling stock and track conditions associated with SMRT Line No. 5.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.107-111
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• 2008

This paper presented a literature review and investigation analysis results of total 19 present guide book and provisions of maintenance and management system in existing railway bridges to development of urban maglev track structures inspection manual. This research carried out a cooperated research subject 3-1, development a design code and maintenance and management inspection manual for urban maglev track structures, of the Center for Urban Maglev Program. Three types of track structures were includes as a major analytical parameter together with railroad, high speed railroad, subway and light rail transit. Bridges were analyzed a general rules, investigation, evaluation, repair and strengthen method as a key aspect. And rail were analyzed examination and maintenance also. This analysis results show that the track structures evaluation are based on the test and examination results, and repaired or strengthened consideration of deterioration, track irregularity and materials according to provision requirements.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1024-1028
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• 2008

The ballast, one of track components, plays an essential role as intermedium in transmitting train load to subgrade safely, and the deterioration of ballast directly effects the growth of track irregularity. In this study, we determined the main factor of ballast deterioration was miniature of ballast gravel caused MTT(Multiple Tie Tamper) works and accumulated traffic loads. To estimate the deterioration characteristics of ballast, we carried out field test through track construction for test and the model test simulating the actual operation environment, have done a comparative analysis with the sample's result(crushing rate) of high-speed railroad running actually.

• YAKHAK HOEJI
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• v.50 no.6
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• pp.367-371
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• 2006

Phellinus pini (Hymenocaetaceae) has been used for the immunomodulating activity hypolipidemic effect, gastric cancer non-insulin dependant diabetes, diarrhea, and menstrual irregularity. From the screening of each fraction for the inhibitory activity of NO production in lipopolysaccaride (LPS) activated RAW 264.7 cells, methanol extract of Phellinus pini and hexane soluble fraction exhibited inhibition of NO production compared with LPS control without toxicity. The hexane soluble fraction showed dose dependent inhibition of NO production. According to activity guided fractionation, the active hexane fr. was repeatedly chromatographed over silica gel, ergosta-4,6,8(14),22- tetraen-3-one was isolated. The compound inhibited NOS activation (IC$_{50}$ = 29.7 uM) and NO production of activated macrophage at 30 uM.

• Journal of Korean Foot and Ankle Society
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• v.22 no.4
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• pp.177-180
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• 2018

This paper reports a rare case of the symptomatic third metatarsal (MT3) - lateral cuneiform (LC) in a 55-year-old male who presented with complaints of severe intermittent pain in his right foot. Plain radiographs and computed tomography scans revealed sclerosis and irregularity at this joint. The intraoperative findings demonstrated a fibrocartilaginous coalition. The pain had improved one year after removing the MT3-LC joint by en bloc and arthrodesis.

• Journal of Neurocritical Care
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• v.11 no.2
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• pp.63-70
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• 2018

Management of mechanical ventilation is essential for patients with neuro-critical illnesses who may also have impairment of airways, lungs, respiratory muscles, and respiratory drive. However, balancing the approach to mechanical ventilation in the intensive care unit (ICU) with the need to prevent additional lung and brain injury, is challenging to intensivists. Lung protective ventilation strategies should be modified and applied to neuro-critically ill patients to maintain normocapnia and proper positive end expiratory pressure in the setting of neurological closed monitoring. Understanding the various parameters and graphic waveforms of the mechanical ventilator can provide information about the respiratory target, including appropriate tidal volume, airway pressure, and synchrony between patient and ventilator, especially in patients with neurological dysfunction due to irregularity of spontaneous respiration. Several types of asynchrony occur during mechanical ventilation, including trigger, flow, and termination asynchrony. This review aims to present the basic interpretation of mechanical ventilator waveforms and utilization of waveforms in various clinical situations in the neuro-ICU.

• Structural Engineering and Mechanics
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• v.82 no.2
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• pp.191-204
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• 2022

A three-mass vehicle model including one rigid mass and two unsprung masses is adopted to predict the vehicle-bridge interaction (VBI) and to establish the nonlinear coupled governing equations. To overcome the numerical instability and large computation problems concerning the vehicle-bridge system, the perturbation method is used to convert the nonlinear coupled governing equations into a set of linear uncoupled equations. Formulas for bridge's natural frequencies considering both the VBI and the dynamic responses of bridge and vehicle are proposed. Compared with the numerical results obtained by the Newmark-β method, the theoretical solutions for natural frequencies and dynamic responses are validated. The effects of the important factors of unsprung mass, vehicle damping, surface irregularity on the natural frequencies and dynamic responses of bridge and vehicle are discussed, based on the theoretical solutions.

• Earthquakes and Structures
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• v.22 no.3
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• pp.305-318
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• 2022

This paper presents a comparative study of the damage potentials for the 2016 Gyeongju and 2017 Pohang earthquakes in Korea. Plausible technical explanations are provided for the more severe damage observed in the 2017 Pohang earthquake in spite of its relatively weaker magnitude and intensity measures based on the response analysis of elastic and inelastic single-degree-of-freedom systems for the recorded ground motions. In addition, a detailed case study was conducted for a fatally damaged piloti building with an eccentric shear wall core based on nonlinear dynamic analysis using the input ground motions modified for the building site.

• Restorative Dentistry and Endodontics
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• v.32 no.5
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• pp.411-418
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• 2007

The most scientific and reliable method for deciding the tooth color is the instrumental measurement. However, such color measuring instrument shows the difference of the measuring value according to the diversified measuring condition. This study was conducted to evaluate what effect of the labial surface irregularity of the tooth to the result of the color measured by spectrometer. 11 models of the teeth were made by injecting the A2 shade Luxatemp Automix Plus (DMG, Germany) into the impression acquired from 11 adults. Standard disk samples (15 mm diameter, 7 mm thickness) were made with same material. CIE $L^*a^*b^*$ value was measured at the incisal, central, and gingival area of the central incisor, lateral incisor, canine and first premolar using Specbos 2100 (JETI, Germany) spectrometer. Color difference was calculated between labial surface and standard samples. Among all models of the teeth, $L^*\;and\;b^*$ value showed the reducing tendency as they go toward the gingival area, but $a^*$ value showed the increasing tendency. Color difference between model teeth and standard samples showed the most difference at the incisal area, but the gingival area showed the least difference. And the canine showed the least color difference from the comparison of standard sample, and the central incisor showed the highest difference (p < 0.01). Although the visually detectable difference of the measuring value showed notably depending on the type and measured area (p < 0.05), $L^*\;and\;a^*$ value showed notable differences depending more on the measured areas than on the type of the teeth.