• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.343.1-343
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• 1998

No Abstract, See Full Text

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.889-893
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• 1987

This paper suggests a model for the economic evaluation and the selection of alternatives using teletraffic. Economic evaluation is analyzed by the comparison of revenue loss which happens without trunk extension and additional revenue which results from trunk extension. Simulation technique is used as a methodology to apply economic evaluation to telephone system. The study results will provide a support in a optimal decision about investment strategies.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.750-751
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• 2008

본 논문은 컨버터용 변압기의 여자전류 해석을 통해 DC 성분 유입시 자속밀도-여자전류 곡선 그래프를 도출하여 철심포화 여부를 확인하며, 철심 공극에 의해 발생되는 누설자속(Leakage Flux)으로 인한 철구조물(Lock Plate)의 와전류 손실을 계산하였다. 변압기 해석을 위해 상용 해석 소프트웨어인 Maxwell 3D를 이용하였고, 철심의 비선형성을 고려하여 해석하였다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.48 no.4
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• pp.245-245
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• 2022

• Journal of Korean Neurosurgical Society
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• v.30 no.8
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• pp.998-1003
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• 2001

Objective : The maintenance of the correction of kyphotic deformity is one of the difficult problem in tuberculous spondylitis after anterior debriment and fusion with tricortical bone graft. The goal of this study is to find out the efficacy of titanium mesh cage impacted with autogenous bone chip in tuberculous spondylitis treated with anterior intervertebral fusion. Materials and Method : Twelve patients were treated with anterior intervertebral fusion using titanium mesh cage for tuberculous spondylitis from January 1996 to June 1999. We analized the changes in the correction of kyphotic deformity, changes of ESR and CRP, fusion state and recurrence after anterior intervertebral fusion with titanium mesh cage. Results : Clinical symptoms were improved in all twelve patients without any neurologic complications. The mean kyphotic angle corrected was 7.3 degrees immediately after operation, but the loss of correction of kyphotic angle was 2.2 degrees after 3 months and 2.6 degrees after 6 months. We found that the loss of correction of kyphotic deformity occurred mainly within the first 3 months after surgery. Only one patient, suffered from acute hepatic failure after first operation and had an insufficient anti-tuberculous medication therapy, showed recurrence of tuberculous spondylitis after 6 months. The patient underwent a second operation with posterior fixation procedure with good outcome. The changes of ESR and CRP were not specifically important factor to reveal recurrence of tuberculosis of the spine in our series. Conclusion : The surgical procedure of tuberculous spondylitis using titanium mesh cage with bone chip seems to be an effective procedure to minimize loss of the correction of kyphotic deformity without any aggravating inflammatory change and recurrence with titanium mesh cage, when sufficient debridement and anti-tuberculous chemotherapy are achieved.

• Biomolecules & Therapeutics
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• v.20 no.5
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• pp.463-469
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• 2012

Atopic dermatitis is a chronic, inflammatory disease of the skin with increased transepidermal water loss. Both an abnormal inflammatory response and a defective skin barrier are known to be involved in the pathogenesis of atopic dermatitis. Protease activated receptor 2 (PAR2) belongs to a family of G-protein coupled receptors and is activated by both trypsin and a specific agonist peptide, SLIGKV-$NH_2$. PAR2 is expressed in suprabasal layers of the epidermis and regulates inflammatory responses and barrier homeostasis. In this study, we show that nordihydroguaiaretic acid (NDGA) inhibits the PAR2-mediated signal pathway and plays a role in skin barrier recovery in atopic dermatitis. Specifically, NDGA reduces the mobilization of intracellular $Ca^{2+}$ in HaCaT keratinocytes by down-regulating inflammatory mediators, such as interleukin-8, thymus and activation-regulated chemokine and intercellular cell adhesion molecule-1 in HaCaT keratinocytes. Also, NDGA decreases the protein expression of involucrin, a differentiation maker of keratinocyte, in both HaCaT keratinocytes and normal human epidermal keratinocytes. We examined NDGA-recovered skin barrier in atopic dermatitis by using an oxazolone-induced atopic dermatitis model in hairless mice. Topical application of NDGA produced an increase in transepidermal water loss recovery and a decrease in serum IgE level, without weight loss. Accordingly, we suggest that NDGA acts as a PAR2 antagonist and may be a possible therapeutic agent for atopic dermatitis.

• Nuclear Engineering and Technology
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• v.47 no.3
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• pp.240-252
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• 2015

In the original licensing application for the prototype fast-breeder reactor, MONJU, the event progression during an unprotected loss of flow (ULOF), which is one of the technically inconceivable events postulated beyond design basis, was evaluated. Through this evaluation, it was confirmed that radiological consequences could be suitably limited even if mechanical energy was released. Following the Fukushima-Daiichi accident, a new nuclear safety regulation has become effective in Japan. The conformity of MONJU to this new regulation should hence be investigated. The objectives of the present study are to conduct a preliminary evaluation of ULOF for MONJU, reflecting the knowledge obtained after the original licensing application through CABRI experiments and EAGLE projects, and to gain the prospect of in-vessel retention for the conformity of MONJU to the new regulation. The preliminary evaluation in the present study showed that no significant mechanical energy release would take place, and that thermal failure of the reactor vessel could be avoided by the stable cooling of disrupted-core materials. This result suggests that the prospect of in-vessel retention against ULOF, which lies within the bounds of the original licensing evaluation and conforms to the new nuclear safety regulation, will be gained.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.4 no.2
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• pp.153-163
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• 2000

The non-dimensional convective heat losses from each surface are investigated as a function of the non-dimensional fin length, width and the ratio of upper surface Biot number to bottom surface Biot number (Bi2/Bi1) using the three-dimensional separation of variables method. Heat loss ratio in view of each surface with the variation of Bi2/Bi1 is presented. The variation of the non-dimensioal temperare profile along the fin center line for a thermally asymmetric conditions is also presented.

• Journal of Ceramic Processing Research
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• v.22 no.1
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• pp.54-60
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• 2021

Cracking in ceramics poses a serious threat to the safety of components. In the study of crack healing, SiO2 was the healingmaterial. In this study, TiO2 was added to improve the strength of ceramics, and SiO2 was added or coated to heal cracking. These show effectiveness by heat treatment. The bending strength increased by adding TiO2 and SiO2, and the frictioncoefficient and wear loss were smaller than that of the non-addition.

• Journal of Korea Water Resources Association
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• v.46 no.5
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• pp.559-568
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• 2013

Surface compaction significantly impacts runoff and soil erosion under rainfall since it leads to changes of soil physical characteristics such as increase of bulk density and shear stress, change of microporosity, and decrease of hydraulic conductivity. This study addressed surface compaction effects on runoff and soil loss from bare and disturbed soils that are commonly distributed on construction sites. Thirty-six rainfall simulations from three replicates of each involving rainfall intensities (68.5 mm/hr, 95.6 mm/hr) and plot gradients ($5^{\circ}$, $12.5^{\circ}$, $20^{\circ}$) were conducted to measure runoff and soil loss for two different soil surface treatments (compacted surface, non-compacted surface). Compacted surface increased significantly soil bulk density and soil strength. However, the effect of surface treatments on runoff changed with rainfall intensity and plot gradient. Rainfall intensity and plot gradient had a positive effect on mean soil loss. In addition, the effect of surface treatments on soil loss responded differently with rainfall intensity and plot gradient. Compacted surfaces increased soil loss at gentle slope ($5^{\circ}$) while they decreased soil loss at steep slope ($20^{\circ}$). These results indicate that there exists transitional slope range ($10{\sim}15^{\circ}$) between gentle and steep slope by surface compaction effects on soil loss under disturbed bare soils and simulated rainfalls.