• Structural Engineering and Mechanics
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• v.48 no.6
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• pp.791-807
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• 2013

Ultra High Performance Cementitious Composites with compressive strength 200MPa (UHPCC-200) is proposed for the structural design of super high hybrid wind turbine tower to gain durability, ductility and high strength design objectives. The minimal wall thickness is analyzed using basic bending and compression theory and is modified by a toque influence coefficient. Two cases of wall thickness combination of middle and bottom segment including varied ratio and constant ratio are considered within typical wall thickness dimension. Using nonlinear finite element analysis, the effects of wall thickness combinations with varied and constant ratio and prestress on the structural stress and lateral displacement are calculated and analyzed. The design limitation of the segmental wall thickness combinations is recommended.

• Journal of Korean Neurosurgical Society
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• v.49 no.4
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• pp.226-228
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• 2011

We report a case of spontaneous right carotid-cavernous fistula (CCF) in a proximal segment of persistent primitive trigeminal artery (PPTA) and combined vascular anomalies such as left duplicated hypoplastic proximal posterior cerebral arteries and a variation of anterior choroidal artery supplying temporal and occipital lobe. A 45-year-old male presented with progressive right exophthalmos, diplopia, and ocular pain. With manual compression of the internal carotid artery, a cerebral angiography revealed a right CCF from a PPTA. Treatment involved the placement of detachable non-fibered and fibered coils, and use of a hyperglide balloon to protect against coil herniation into the internal carotid artery. A final angiograph revealed complete occlusion of PPTA resulted in no contrast filling of CCF.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.746-750
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• 2007

Vertebroplasty has drawn much attention as a medical treatment for the compression fracture of spine, which strengthens the vertebral body and corrects deformity, and relieves pain in patients by injecting bone cement. However vertebroplasty can cause fracture on adjacent vertebra due to relative stiffness change. This study involves the biomechanical evaluation of the vertebroplasty especially on adjacent vertebral body. The finite element method has been employed to analyze the patient who was treated vertebroplasty under static and dynamic loading. For this study, a three-dimentioal model of the three-level ligamentous lumbar segment ($L1{\sim}L3$)is created from medical image data (CT)and compared with the experimental results in vitro.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1012-1017
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• 2007

To reduce the cost and the time of transport in Eurasian railroad networks such as TKR(Trans-Korea Railway), TCR(Trans-China Railway) and TSR(Trans-Siberia Railway) owing to the problem of different track gauges (narrow/standard/broad gauge), it is important to develop the gauge - adjustable wheelset system to adapt easily to these gauges. Moreover, this system accomplishes periodically a conversion operation from the gauge variable segment between different gauge. Gauge adjustable compression coil spring during conversion process accomplishes repetitively a central role for operation mechanism between flange and locking part. Therefore, to assure the safety of the gauge-adjustment wheelset system, it is necessary to stress analysis of the optimized spring in the system. In this study, it was performed to optimal design of the spring for stress analysis by using the genetic algorithm.

• Journal of Chest Surgery
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• v.21 no.2
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• pp.389-394
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• 1988

The patient was 22-year old male who had been suffered from labored breathing. Computerized tomography, tracheoscopy, tracheogram disclosed tracheal obstruction by external mass compression on Tl level, which ranged 4.Oem in the length and approximately 4mm in diameter on tracheogram. Under the local anesthesia, tracheostomy was done to prevent intraoperative airway obstruction. And general anesthesia, low collar incision 8z extended median sternotomy was made and nearly total thyroidectomy was performed. After the circumferential resection of the obstructed segment approximately 4cm in length[7 tracheal rings], direct end-to-end anastomosis of trachea was performed. Postoperatively, the patient`s neck was maintained in flexion state to reduce tension of anastomotic site. Postoperatively. medical therapy[Comthyroid k Calcium lactate] and radiotherapy were done. At present, 2-months after operation, he lives well.

• The Korean Journal of Pain
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• v.26 no.1
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• pp.76-79
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• 2013

During the early stage of postherpetic neuralgia, an epidural block on the affected segment is helpful in controlling pain and preventing progression to a chronic state. The main neurologic complication following an epidural block is cord compression symptom due to an epidural hematoma. When neurologic complications arise from an epidural block for the treatment of postherpetic neuralgia, it is important to determine whether the complications are due to the procedure or due to the herpes zoster itself. We report a case of a patient who was diagnosed with herpes zoster myelitis during treatment for postherpetic neuralgia. The patient complained of motor weakness in the lower extremities after receiving a thoracic epidural block six times. Although initially, we believed that the complications were due to the epidural block, it was ultimately determined to be from the herpes zoster myelitis.

• Communications of the Korean Mathematical Society
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• v.38 no.2
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• pp.431-450
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• 2023

The basic goal of quantization for probability distribution is to reduce the number of values, which is typically uncountable, describing a probability distribution to some finite set and thus to make an approximation of a continuous probability distribution by a discrete distribution. It has broad application in signal processing and data compression. In this paper, first we define the uniform distributions on different curves such as a line segment, a circle, and the boundary of an equilateral triangle. Then, we give the exact formulas to determine the optimal sets of n-means and the nth quantization errors for different values of n with respect to the uniform distributions defined on the curves. In each case, we further calculate the quantization dimension and show that it is equal to the dimension of the object; and the quantization coefficient exists as a finite positive number. This supports the well-known result of Bucklew and Wise [2], which says that for a Borel probability measure P with non-vanishing absolutely continuous part the quantization coefficient exists as a finite positive number.

• Journal of Yeungnam Medical Science
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• v.20 no.2
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• pp.160-168
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• 2003

Background: Confirm the stability of intervertebral disc sustaining each fused lumbar spine cases, comparing vertical compression, A-P shear force and rotational moment on intervertebral disc of instrumented lumbar spine with simple vertical compression load and follower load using finite element analysis. Materials and Methods: We analyze the stability of intervertebral disc L4-5 supporting fused lumbar spine segments. After performing finite element modelling about L1-L5 lumbar vertebral column and L1-L4 each fusion level pedicle screw system for fused lumbar spine fine element model. Intervertebral discs with complex structure and mechanical properties was modeled using spring element that compensate stiffness and tube-to-tube contact element was employed to give follower load. Performing geometrical non-linear analysis. Results: The differences of intervertebral disc L4-5 behavior under the follower compression load in comparision with vertical compression load are as follows. Conclusion: As a result of finite element interpretation of instrumented lumbar spine, the stability of L4-5 sustaining fused lumbar segment, the long level fused lumbar spine observed hing stability under follower load. This research method can be the basis tool of effects prediction for instrumentation, a invention of a more precious finite element interpretation model which consider the role of muscle around the spine is loaded.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2449-2456
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• 2013

The column-oriented database storage is a very advanced model for large-volume data analysis systems because of its superior I/O performance. Traditional data storages exploit row-oriented storage where the attributes of a record are placed contiguously in hard disk for fast write operations. However, for search-mostly datawarehouse systems, column-oriented storage has become a more proper model because of its superior read performance. Recently, solid state drive using MLC flash memory is largely recognized as the preferred storage media for high-speed data analysis systems. In this paper, we introduce fast column-oriented data storage model and then propose a new storage management scheme using a cross compressed replication for the high-speed column-oriented datawarehouse system. Our storage management scheme which is based on two MLC SSD achieves superior performance and reliability by the cross replication of the uncompressed segment and the compressed segment under high workloads of CPU and I/O. Based on the results of the performance evaluation, we conclude that our storage management scheme outperforms the traditional scheme in the respect of update throughput and response time of the column segments.

• The Journal of the Acoustical Society of Korea
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• v.15 no.2
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• pp.40-48
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• 1996

In this paper, a 40 dimensional segment vector with 4 frame and 7 frame width in every monosyllable interval was compressed into a 10, 14, 20 dimensional vector using K-L expansion and neural networks, and these was used to speech recognition feature parameter for CHMM. And we also compared them with CHMM added as feature parameter to the discrete duration time, the regression coefficients and the mixture distribution. In recognition test at 100 monosyllable, recognition rates of CHMM +${\bigtriangleup}$MCEP, CHMM +MIX and CHMM +DD respectively improve 1.4%, 2.36% and 2.78% over 85.19% of CHMM. And those using vector compressed by K-L expansion are less than MCEP + ${\bigtriangleup}$MCEP but those using K-L + MCEP, K-L + ${\bigtriangleup}$MCEP are almost same. Neural networks reflect more the speech dynamic variety than K-L expansion because they use the sigmoid function for the non-linear transform. Recognition rates using vector compressed by neural networks are higher than those using of K-L expansion and other methods.