• 교육시설 논문지
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• 제19권3호
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• pp.33-40
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• 2012

At present, the problem to secure seismic resistance capacity is one of the most important issue in school buildings. However, the range of facilities to consider retrofit or the proper direction of seismic retrofit haven't provided in details. Therefore in this study, a series of school buildings were chosen as established time, and the structure composition and the seismic performance of the school buildings were investigated to get the comprehensive features of seismic resistance capacity in school buildings. At result, it was presented that the member capacities were less than criteria and structure system was showed the brittle behavior at the collapse prevention level at the school buildings before 1990 year. At the school buildings after 1990 year, though it is hard to get general features for various compositions, it was presented that they have problems for seismic performance evaluation in some buildings at life safety level, specially in the direction of X axis. So, considering the introduction process of seismic criteria in Korea, the school buildings before 2005 year should be examined for seismic resistance capacity and the seismic performance should be examined as well as member capacity to resist seismic.

• Carbon letters
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• 제10권3호
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• pp.225-229
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• 2009

Thermal emissivity of commercial nuclear graphites (IG-110, PCEA, IG-430 and NBG-18) following changes in oxidation degrees were examined. Specimens were oxidized to 0%, 5%, and 10% in air flow of 5l/min at $600^{\circ}C$ using a furnace, and the thermal emissivities were measured using an infrared spectrum analyzer. The measuring temperatures for the thermal emissivity were $100^{\circ}C$, $200^{\circ}C$, $300^{\circ}C$, $400^{\circ}C$ $500^{\circ}C$. Also density and porosity of the specimens were observed to compare with thermal emissivity. Results showed that emissivity increased with oxidation, and the 10% oxidized NBG-18 showed the highest emissivity (0.890) which value is larger for 24% than the value of as-received specimen. Investigation of factors affecting the emissivity revealed that increases in the surface roughness and porosity due to oxidation were responsible for the increase in emissivity after oxidation.

• Journal of Electrical Engineering and Technology
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• 제8권3호
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• pp.446-452
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• 2013

Under frequency load shedding (UFLS) is an effective way to prevent system blackout after a serious disturbance occurs in a power system. A novel centralized adaptive under frequency load shedding (AUFLS) scheme using the synchronous phase measurement unit (PMU) is proposed in this paper. Two main stages are consisted of in the developed technique. In the first stage, the active power deficit is estimated by using the simplest expression of the generator swing equation and static load model since the frequency, voltages and their rate of change can be obtained by means of measurements in real-time from various devices such as phase measurement units. In the second stage, the UFLS schemes are adapted to the estimated magnitude based on the presented model. The effectiveness of the proposed AUFLS scheme is investigated simulating different disturbance in IEEE 10-generator 39-bus New England test system.

• Journal of Power Electronics
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• 제16권2호
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• pp.786-797
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• 2016

This paper describes the design and development of a novel semiconductor-based solid-state switch for damped oscillating voltage test system. The proposed switch is configured as two identical series-connected switch stacks, each of which comprising 10 series-connected IGBT function units. Each unit consists of one IGBT, a gate driver, and an auxiliary voltage sharing circuit. A single switch stack can block 20 kV-rated high voltage, and two stacks in series are proven applicable to 30 kV-rated high voltage. The turn-on speed of the switch is approximately 250 ns. A flyback topology-based power supply system with a front-end power factor correction is built for the drive circuit by loosely inductively coupling each unit with a ferrite core to the primary side of a power generator to obtain the advantages of galvanic isolation and compact size. After the simulation, measurement, and estimation of the parasitic effect on the gate driver, a prototype is assembled and tested under different operating regimes. Experimental results are presented to demonstrate the performance of the developed prototype.

• Journal of Power Electronics
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• 제16권6호
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• pp.2359-2367
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• 2016

Inductive power transfer (IPT) systems have become increasingly popular in recharging electric vehicle (EV) batteries. This paper presents an investigation of a series parallel/series (SP/S) resonant compensation network based IPT system for EVs with further optimized circular pads (CPs). After the further optimization, the magnetic coupling coefficient and power transfer capacity of the CPs are significantly improved. In this system, based on a series compensation network on the secondary side, the constant output voltage, utilizing a simple yet effective control method (fixed-frequency control), is realized for the receiving terminal at a settled relative position under different load conditions. In addition, with a SP compensation network on the primary side, zero voltage switching (ZVS) of the inverter is universally achieved. Simulations and experiments have been implemented to validate the favorable applicability of the modified optimization of CPs and the proposed SP/S IPT system.

• Journal of Chest Surgery
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• 제55권1호
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• pp.81-84
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• 2022

Esophagectomy and esophageal reconstruction are commonly chosen as surgical options for esophageal cancer. However, prolonged untreated chyle leakage is associated with a poor prognosis. We report the case of a patient with refractory chylous ascites. To limit the ongoing fluid loss, we utilized the chylous ascites as an additional fluid source in a renal replacement therapy system. A continuous renal replacement therapy (CRRT) drainage system was modified to drain both the chylous ascites and venous blood. The ascites drainage rate was determined empirically and regulated by a dial-flow extension set. The CRRT mode was set to continuous venovenous hemodiafiltration and maintained for 7 days. After the patient was weaned from CRRT, ascites did not reaccumulate, and the patient's general condition improved dramatically. No infections related to the system occurred. This procedure temporarily alleviates symptoms and provides more time for alternative treatment strategies.

• Structural Engineering and Mechanics
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• 제81권1호
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• pp.69-79
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• 2022

The dynamic responses of a pier-pile-soil system subjected to a barge/flotilla collision are analyzed. A coupled high-speed train and bridge system with a damaged pier after barge/flotilla collision is established by taking the additional unevenness of the track induced by the damaged pier as the self-excitation of the system. The whole process of a CRH2 high-speed train running on the 6×32 m simply-supported PC (prestressed concrete) box-girder bridge with a damaged pier is simulated as a case study. The results show that the lateral displacements and accelerations of the bridge with a damaged pier are much greater than the ones before the collision. The running safety indices of the train increase with the train speed as well as with the number of barges in the flotilla. In flotilla collision, the lateral wheel/rail forces of the train exceed the allowable values at a certain speed, which influences the running safety of the trains.

• 대한한의학방제학회지
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• 제19권1호
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• pp.161-174
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• 2011

Objectives : The effects of Extraction after Mixture of Bupleuri Radix and Lycii Radicis Cortex on the change of the HPA-Axis system and the Catecholamic system was investigated. Methods : After performing the Forced Swimming Test(FST), the expressions of corticotropin releasing factor(CRF), c-Fos in the paraventricular nucleus(PVN), and tyrosine hydroxylase(TH) in the ventral tegmental area(VTA) and locus coeruleus(LC) were measured by immunohistochemical method. Results : The duration of immobility in FST was significantly decreased in A 100(Extraction after Mixture of Bupleuri Radix and Lycii Radicis Cortex, 100mg/kg) and A 400(Extraction after Mixture of Bupleuri Radix and Lycii Radicis Cortex, 400mg/kg)(p<0.001). The expression of CRF in the PVN was shown the tendency to reduce in A100 and A400. The expression of c-Fos in the PVN was shown the tendency to reduce in A100 and A400. The expression of TH in the VTA was shown the tendency to reduce mildly in A100 and A400. The expression of TH in the LC was significantly reduced in A400(p<0.001). And the dose dependent reduction tendency was shown, respectively. Conclusions : According to the results above mentioned, the immobility, c-Fos and CRF expression was reduced at lower dose and was increased at higher dose. Therefore there is contradictory effects on the HPA Axis system in accordance with the dose. But in the effects on the catecholaminergic system, it significantly reduced the expression of TH in the LC. It was validated that the effect on the catecholaminergic system was ruled by Bupleuri Radix rather than Lycii Radicis Cortex via mainly the noradernergic system.

• 약학회지
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• 제50권3호
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• pp.145-153
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• 2006

The adverse events which do not appear in the approval process tend to occur more frequently at the early stage of the use. Therefore new drugs, drugs with different active substances or routes of administration, or drugs with explicitly different efficacy added are particularly chosen for re-examination, and go through a study, which is conducted on 600 to 3,000 subjects over 4 to 6 years. Since the re-examination system was implemented in January 1995, 880 drug products have been designated as the subject of re-examination and among them 194 drugs have been completed their re-examination as of until March 2005. Post Marketing Surveillance to insure drug safety should be correlated with re-examination of new drug, re-evaluation of drug, and adverse event monitoring system. And the first labeling change should reflect all information collected for a defined period of time after the marketing authorization is granted. Furthermore centralized management through spontaneous reporting system of adverse event for whole period of time would be the most desirable type of system.

• International Journal of Control, Automation, and Systems
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• 제5권1호
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• pp.104-109
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• 2007

This paper is about a redundancy management system design for the Smart UAV(unmanned aerial vehicle) which utilizes the tilt..rotor mechanism. In order to meet the safety requirement on the PLOC(probability of loss of control) of $1.7{\times}10^{-5}$ per flight hour for FCS (flight control system) failures, a digital FCS is mechanized with a dual redundant structure. A fault detection system which is composed of a CCM(cross channel monitor) and analytic redundancy using the Kalman filtering is designed, and its effectiveness is evaluated through experiments. A threshold level and persistence count for managing redundant sensors are designed based on the statistical analysis of the FCS sensors. To increase the survivability of the UAV after the loss of critical sensors in the SAS(stability augmentation system) and to provide reference information for a tie-breaking condition at which an ILM(in-line monitor) cannot distinguish the faulty channel between two operating ones, the Kalman filter approach is investigated.