• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2001.05a
• /
• pp.127-132
• /
• 2001

In this paper, transmitted sound reduction performance of smart panels is studied according to different piezoelectric materials with piezoelectric shunt damping. Peizo-damping is implemented by using a newly proposed tuning method. This method is based on electrical impedance model and maximizing the dissipated energy at the shunt circuit. By measuring the electrical impedance at the piezoelectric patch bonded on a structure, an equivalent electrical model is constructed near the system resonance frequency. After shunting elements are connected to the equivalent circuit, the shunt parameters are optimally searched based on the criterion of maximizing the dissipated energy at the shunt circuit. Transmitted sound reduction performance is compared according to different piezoelectric materials with peizo-damping. Two piezoelectric materials are selected: PZT-5 and QuickPack IDE actuator. When resonant shunt circuit is considered, the use of PZT-5 exhibited the good sound reduction performance.

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.1466-1474
• /
• 2007

In large station with high density traffic, trains is hardly controlled by CTC but by station dispatcher because CTC has difficulties in monitoring all states of affairs happening within the station such as departs and arrivals of many trains from different lines and shunting trains between yards and platforms, etc. Therefore station dispatcher has to make quick decision about how to schedule all trains including trains to arrive and depart before long. And such decisions become harder when an unexpected delay occurs. This study suggests a mathematical model and algorithm about how to detect in advance and resolve efficiently the conflicts occurring within a station and it will be shown how to reduce delay using our approach by means of analysing the schedule of ChyungRyangRi station.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.1100-1105
• /
• 2010

The high speed line and conventional line are a single-phase AC feeding system; and power supplies of different phases meet at SS(SubStation)s or SP(Sectioning Post)s. These sections should be negotiated with the main circuit breaker in the traction vehicle switched off, whereby the length of the neutral zone prevents the pantographs shunting adjacent overhead line section. In order for electric railway vehicles to make power running there, there must be a power supply changeover section (approx. for 1km), where a changeover switch changes a power supply to the other power supply of a train running direction sequentially. For a thorough changeover switching control, the precise train position detection is necessarily required. In this paper, to realize the ground-based train position detection method, configuration scheme of train position detection equipment is suggested by using track circuit and axle counter.

• Journal of Korean Neurosurgical Society
• /
• v.54 no.5
• /
• pp.441-443
• /
• 2013

Liver abscess following ventriculoperitoneal (VP) shunting occurs very rarely. We report an unusual case of multiple liver abscesses caused by Staphylococcus capitis in a 50-year-old compromised woman due to a complicating VP shunt infection. We reviewed the nine cases of VP shunt complications reported in the English literature, and speculated that the most likely pathogenetic mechanism in our case is an infected peritoneal tip that migrated to and penetrated the liver, which subsequently caused the formation of multiple liver abscesses. The patient was successfully treated with percutaneous aspiration, drainage of the abscesses, intravenous antibiotics, and shunt revision. Awareness and vigilance of the possibility of liver abscess formation caused by VP shunt infection will help establish an early accurate diagnosis and therapeutic strategy.

• Journal of Chest Surgery
• /
• v.24 no.1
• /
• pp.106-112
• /
• 1991

A 37-year old man was admitted due to the left subauricular mass of 6 month duration which was 3 x 4cm sized, pulsatile and slowly growing He was suffered from the intermittent left facial and auricular pain radiating to the occipital area. The carotid angiography revealed 3x4cm sized saccular aneurysm of the left internal carotid artery just above the carotid bifurcation, extending to the mandibular angle level. He was planned to be operated under the direct clamp of internal carotid artery or shunting procedure. But, the back pressure of the internal carotid was 35mmHg, which suggested adequate cerebral collateral. Thereby, aneurysmectomy and restoration of cerebral blood flow with saphenous vein graft was done under the direct clamp of internal carotid artery for 25 minutes. Although mild transient neurologic sequelae such as mydriasis, tongue deviation for 10 days, he recovered completely without any complication. The aneurysmal sac had no thrombus and pathologic finding was compatible with congenital origin.

• Journal of Chest Surgery
• /
• v.21 no.1
• /
• pp.101-108
• /
• 1988

Between July, 19S4. and July, 1987, 9 two-stage repair of symptomatic tetralogy of Fallot were carried out at the department of thoracic and cardiovascular surgery, Kyungpook national university hospital. Their age ranged from 5 years to 18 years [mean age 9.4 years] at the time of total correction, and there were improvement of systemic oxygen saturation values by 10% and decrease of hemoglobin by 1.6gm/dl after shunt procedures. The interval between the initial shunting procedure and total correction ranged for 7 to 101 months with a mean of 32.7 months. Four of these patients required patching of the infundibulum alone, three required patching of the right ventricular outflow tract across the pulmonary annulus, and valved conduit was used in one due to coronary artery anomaly. Aortic cross clamping time averaged 122.2minutes [range from 60minutes to 150minutes], and cardiopulmonary bypass time averaged 174.4 minutes [range from 80minutes to 300minutes]. The operative mortality rate was 22% [2/9].

• 대한핵의학회:학술대회논문집
• /
• 1998.11a
• /
• pp.36.2-36.2
• /
• 1998

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• v.11 no.2
• /
• pp.15-29
• /
• 2007

In this paper, we explore some interesting models of the quasi-negative-binomial distribution based on difference differential equations applicable to theory of microorganisms and the situations like that. Some characterizations based on conditional distributions and damage process have been obtained. Further, the distribution of number of accidents as the quasi-negative-binomial distribution in the light of Irwin's theory of ";proneness-liability"; model has been derived. Finally, the proposed model (QNBD) has been applied to study the Shunting accidents, home injuries, and strikes in industries.

• Proceedings of the KSR Conference
• /
• 2008.06a
• /
• pp.684-690
• /
• 2008

LRT System Application Project is performed for the purpose of technical advancement and stabilization of K-AGT system from the viewpoint of practical use and commercialization. For those purpose, the performance test and evaluation procedure for signaling system have been developed, including the scheme of verifying the performance and function of signaling system under driverless multiple train operation environment. In this paper, multiple train operation scheme in K-AGT test line is presented. Test schemes for maintaining the safety distance between trains, operation scenario considering shunting and turning of train, and dia operation schemes in test line are reviewed while researching test vehicle features, route condition and running pattern. Additional equipments for testing each scheme are also reviewed.

• Proceedings of the KSR Conference
• /
• 2008.06a
• /
• pp.748-754
• /
• 2008

This paper studied on the application of Korean Railway Safety Law and Urban Transit Safety Law in Crashworthiness Regulations to the urban maglev vehicle of KIMM. The crashworthiness regulations for urban transit vehicle should be satisfied to the urban maglev vehicles according to crash analysis results using the explicit finite element method. However, according to its numerical results, the crashworthiness regulations of Korean Railway Safety Law were partially satisfied except the coupling and shunting condition. When a commercial urban maglev vehicle is developed in the near future, the crashworthiness regulations of Korean Railway Safety Law should be considered and satisfied during its structural design stage in some details