• Journal of Korean Neurosurgical Society
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• v.40 no.2
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• pp.90-94
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• 2006

Objective : Acute vertebral burst fractures warrant extensive fixation and fusion on the spine. Osteoplasty [vertebroplasty with high density resin without vertebral expansion] has been used to treat osteoporotic vertebral compression fractures. We report our experiences with osteoplasty in acute vertebral burst fractures. Methods : Twenty-eight cases of acute vertebral burst fracture were operated with osteoplasty. Eighteen patients had osteoporosis concurrently. Preoperative MRI was performed in all cases to find fracture level and to evaluate the severity of injury. Preoperative CT revealed burst fracture in the series. The patients with severe ligament injury or spinal canal compromise were excluded from indication. Osteoplasty was performed under local anesthesia and high density polymethylmethacrylate[PMMA] was injected carefully avoiding cement leakage into spinal canal. The procedure was performed unilaterally in 21 cases and bilaterally in 7 cases. The patients were allowed to ambulate right after surgery. Most patients discharged within 5 days and followed up at least 6 months. Results : There were 12 men and 16 women with average age of 45.3[28-82]. Five patients had 2 level fractures and 2 patients had 3 level fractures. The average injection volume was 5.6cc per level Average VAS [Visual Analogue Scale] improved 26mm after surgery. The immediate postoperative X-ray showed 2 cases of filler spillage into spinal canal and 4 cases of leakage into the retroperitoneal space. One patient with intraspinal leakage was underwent the laminectomy to remove the resin. Conclusion : Osteoplasty is a safe and new treatment option in the burst fractures. Osteoplasty with minimally invasive technique reduced the hospital stay and recovery time in vertebral fracture patients.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.5
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• pp.892-901
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• 2001

Despite of many advantages over conventional radio paths, application of the Meteor Burst Path in commercial communication system is so far limited to a few extent because of its low duty rate, which is, less than several percent at best. In order to get through maximum number of data bits during the short interval of each burst, which normally lives a fractions of a second, a sophisticated communication protocol is called for. In this paper, author introduces a communication protocol which can effectively locate and fetch burst signal by sending out periodic detection signal from master station and, with minimal delay, switch over to transmission states so as to put as many data bits through the detected burst as the burst length permits. By analyzing time period required for each transaction steps, the author derives optimal packet length for various bursts which assures to get a message string through in minimum delay. According to the analysis, the author proposes a protocol including a routine which automatically accesses average length of bursts at each environment and automatically adapt length of data packet so as to maximize data throughput under Riven burst conditions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.8B
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• pp.514-524
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• 2005

In optical burst switching(OBS) networks, the ingress edge router assembles packets in the same class queue into the appropriate size of burst. A burst control packet(BCP) is generated for channel reservation of corresponding data burst and sent earlier than the corresponding data burst with an offset time. Offset time is determined considering the number of hops from source to destination and the required quality of service(QoS). After offset time, the burst data is passed through tile pre-configured optical switches without any O/E/O conversion. But a failure in OBS networks may lead to the loss of bursts until the ingress nodes receive the failure indication signal. This results in a significant degradation in QoS. Therefore, in this paper, we propose a fault-tolerant node architecture based on sub-carrier multiplexing to reduce the effects of failure in OBS networks. The Performance of the proposed fault-tolerant node architecture exhibits considerable improvement as compared with the previous ones.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.66.3-67
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• 2021

Low-mass stars form by the gravitational collapse of dense molecular cores. Observations and theories of low-mass protostars both suggest that accretion bursts happen in timescales of ~100 years with high accretion rates, so called episodic accretion. One mechanism that triggers accretion bursts is infalling fragments from the outer disk. Such fragmentation happens when the disk is massive enough, preferentially activated during the embedded phase of star formation (Class 0 and I). Most observations and models focus on the gas structure of the protostars undergoing episodic accretion. However, the dust and ice composition are poorly understood, but crucial to the chemical evolution through thermal and energetic processing via accretion burst. During the burst phase, the surrounding material is heated up, and the chemical compositions of gas and ice in the disk and envelope are altered by sublimation of icy molecules from grain surfaces. Such alterations leave imprints in the ice composition even when the temperature returns to the pre-burst level. Thus, chemical compositions of gas and ice retain the history of past bursts. Infrared spectral observations of the Spitzer and AKARI revealed a signature caused by substantial heating, toward many embedded protostars at the quiescent phase. We present the AKARI IRC 2.5-5.0 ㎛ spectra for embedded protostars to trace down the characteristics of accretion burst across the evolutionary stages. The ice compositions obtained from the absorption features therein are used as a clock to measure the timescale after the burst event, comparing the analyses of the gas component that traced the burst frequency using the different refreeze-out timescales. We discuss ice abundances, whose chemical change has been carved in the icy mantle, during the different timescales after the burst ends.

• Fisheries and Aquatic Sciences
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• v.4 no.2
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• pp.88-92
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• 2001

To examine effects of cadmium on the respiratory burst of kidney phagocytes and antioxidant defense in liver, juvenile red seabream Pagrus major were fed a cadmium-incorporated diet $(1g\;CdC1_2/kg\;diet)$. The respiratory burst activity measured by chemiluminescence (CL) was significantly reduced by oral intake of cadmium. Lipid peroxidation in liver expressed as thiobarbituric acid reactive substances (TBARS) was significantly higher in the fish fed a cadmium-incorporated diet than that of the fish fed a control diet both on Day 3 and Day 9. Liver Glutathione S-transferase (GST) activitiy was significantly increased both on Day 3 and Day 9 by feeding a cadmium-incorporated diet, when compared with the controls. From the present results, it can be concluded that oral intake of cadmium in red seabream is associated with marked reduction of respiratory burst capacity of kidney phagocytes which can elevate susceptibility of fish against infecting pathogens. Cadmium administration also elicits significant increment of lipid peroxidation in liver, and fish try to detoxify cadmium by increasing GST activity.

• Journal of the Korean Society of Safety
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• v.30 no.4
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• pp.168-173
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• 2015

A steam generator tubing is one of the main pressure boundary of the reactor coolant system in the nuclear power plants. Structural integrity refers to maintaining adequate margins against failure of the tubing. Burst pressure of a tube at tube support plate can be higher than that for a free-span tube because failure behaviors could be interfered from the tube support plate. Alternative repair criteria for out-diameter stress corrosion cracking indications in tubes to the drilled type tube support plate were developed, however, there are very limited information to the eggcrate type tube support plate. This paper discussed reinforcement effect of steam generator tube burst pressure with axial out-diameter stress corrosion cracking within an eggcrate type tube support plate. A series of tube burst tests were performed under the room temperature and it was found out that there is no significant but marginal effects.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.279-284
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• 2004

In this study, we suggested the ring creep test using the ring specimen of Arsene for estimating the burst creep properties of the cladding in stead of burst creep test. For this objective, we used the load-displacement conversion relationship of ring specimen called LCRR which had been determined on our previous study at high temperature by performing the ring tensile test and the numerical analysis. Then we carried out both the ring creep test and the burst creep test between 350 $^{\circ}C$ and 600$^{\circ}C$ which were higher then the in-service temperature of the cladding in a reactor. The creep properties from the ring creep test with applying LCRR were compared with those from the burst creep test of closed-end specimens. From the results, it could be seen an very strong relationship between them, especially in Larson- Miller parameter. So, it is expected that we can easily anticipate the creep properties of not only claddings but also various small pressure pipes using the ring creep test.

• Journal of the Korean Society of Safety
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• v.20 no.2 s.70
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• pp.38-43
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• 2005

Several nuclear power plants reported that they often found the combination cracks, which consist of longitudinal and circumferential cracks in the tubes. For the burst pressure of a tube with a single longitudinal or circumferential crack several experimental equations have been proposed in published literatures. But for the combination crack appropriate fracture criterion has not been proposed yet. In this study the burst pressures of a tube with a longitudinal crack or a T-type combination crack consisting of longitudinal and circumferential cracks were obtained experimentally and analytically. Fracture parameters such as crack opening angle (COA) were investigated by using elastic plastic analysis. Also the burst pressure far a T-type combination crack located near a tubesheet was considered to develop a length-based criterion. Because most of the axial, circumferential or combination cracks initiate in roll transition zone near the tubesheet.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.2
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• pp.171-176
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• 2003

Meteor Burst Communication can provide effective and economical means of communication where long distance VHF NLOS(None Line of sight) data transmission is needed; often ranges more than 1200 km. It has been, however, so far considered unsuitable for distance as short as 700km application because of phenomenal decrease in burst durations, which leads to decreation of total duty rate of the system. This paper introduce experimental characteristics of very shot distance MB(Meteor Hurst) path. Also the occurring rate and average length measured on 50km paths between kyongsan-city to Andong-city shows that Meter Burst communication is useful communication system in mountain and valley communication.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.5
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• pp.78-83
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• 2015

In the composite case, the first ply failure is considered total failure of the case. When the case is constructed by filament winding over a metal liner, the first ply failure does not necessarily mean total failure of the case. In this study, we compared the results through finite element analysis and burst test to predict the burst pressure of the hybrid case (filament-wound composite case with metal liner). Through it predicts the burst pressure of the hybrid case, we can determine the thickness of the metal liner and composite.