• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.7
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• pp.561-566
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• 2014

Our Korean traditional cultural inheritance Bangpae Kite has the stable rectangular shield shape decorated with artistic paint or poem and a good flight performance due to the central wind hole. In this paper, to analyse the wind hole effect to kite performance we performed the wind tunnel testing of the various design factor of kite model and air flow visualization passing through the wind hole. As the result of aerodynamic analysis, we knew that the wind hole of kite displays similar function of slot system for the wing high lift device. This fact demonstrates that our ancestor understood the function of slot system and applied effectively to the development of kite flight performance.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.9
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• pp.866-870
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• 2011

In this paper, the aerodynamic forces of a Korean Traditional Bangpae Kite with the wind hole and spanwise curved dihedral were measured by wind tunnel test. For the flat plate kite without the wind hole, the stall presents at ${\alpha}=35^{\circ}$ with $C_{Lmax}$=1.2. The Korean Traditional Bangpae Kite with the wind hole had $C_{Lmax}$=1.05 at ${\alpha}=30^{\circ}$ without the apparent stall phenomena. As the wind hole size growing, the lift and drag of kite were changed slowly after stalling angle of attack. As increasing the leading edge dihedral angle, lift curves were more increased than drag curves. As the growing of wind hole size, the effect of dihedral angle was constant affect to the lift and drag of kite.

• Defense and Technology
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• no.11 s.261
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• pp.62-71
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• 2000

5세기 초반 로마인들은 아드리아노플 전투의 재앙스러웠던 교훈으로 인하여 그들의 군사제도를 조정하는 데에 열중하였는데, 그들은 특히 훈족 기마 궁수병의 효과에 감탄하였다. 이것은 페르시안과의 전투 경험과 결합되어 로마 기병의 발전에 영향을 미쳤다. 이와 같은 새로운 형태의 로마 기병은 처음에는 경무장이었고 조직과 훈련면에서 야만인 페데라티와 구분되었다. 로마의 기병은 서서히 무거운 갑옷을 입게 되고 창, 칼 및 방패를 활과 함께 휴대하기 시작하였다.

• Defense and Technology
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• no.12 s.262
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• pp.58-69
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• 2000

5세기 초반 로마인들은 아드리아노플 전투의 재앙스러웠던 교훈으로 인하여 그들의 군사제도를 조정하는 데에 열중하였는데, 그들은 특히 훈족 기마 궁수병의 효과에 감탄하였다. 이것은 페르시안과의 전투 경험과 결합되어 로마 기병의 발전에 영향을 미쳤다. 이와 같은 새로운 형태의 로마 기병은 처음에는 경무장이었고 조직과 훈련면에서 야만인 페데라티와 구분되었다. 로마의 기병은 서서히 무거운 갑옷을 입게 되고 창, 칼 및 방패를 활과 함께 휴대하기 시작하였다.

• The Korean Journal of Pesticide Science
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• v.3 no.2
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• pp.74-80
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• 1999

These studies were carried out to investigate the effects of nonsteroidal ecdysone agonist, tebufenozide on embryonic and postembryonic development of sycamore lace bug, Corythucha ciliata. Tebufenozide exhibited ovicidal activity($LC_{50}=4.0$ ppm). Susceptibility of each instar nymphs to tebufenozide was nearly same($LC_{50}=2.3{\sim}6.0$ ppm). The tebufenozide treatment in the final instar affected the emergence, longevity and fecundity of surving adults significantly. Tebufenozide applied at high concentration (10 ppm) to younger adults delayed prioviposition period, and decreased adult longevity, the number of eggs laid per female and hatchability. The treatment also inhibited the ovarian development of the female adults.

• Journal of Life Science
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• v.17 no.6 s.86
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• pp.828-830
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• 2007

To determine the effects of newly developed insecticide (Ultra) on Sycamore lace bug (Corythucha ciliata), ten leaf discs were sprayed with the Ultra solution including the other selected commercialized insecticide solutions such as Carbaryl and Pirimicarb, and also with a water-sprayed control. According to the results, the control effect of Ultra on the adults and immatures was respectively 98.9% and 97.5% after 48hr, and the corresponding values were higher than that of the other tested insecticides (i.e Carbaryl showed 84.6% for adults and 85.6% for immatures; Pirimicarb showed 83.0% for adults and 90.7% for immatures). For the Susceptibility test, LC$_{50}$ value of Ultra showed the lowest as 1.5ppm, the value of Carbaryl and Pirmicarb were 3.7 ppm and 30.4 ppm, respectively. Therefore, the insecticidal effects were better for the newly developed insecticide than the commercialized insecticides.

• Explosives and Blasting
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• v.23 no.2
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• pp.23-35
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• 2005

Excavation of an opening in a saturated porous rock may lead to the development of pore pressure around the opening due to the redistribution of initial rock stresses. The built-up of pore pressure, in turn, may affect the mechanical behavior of rock mass and give the different pattern of stress distribution around the opening from that of the case where the coupling is neglected. In this study, the short time response of an opening excavated in saturated ground under anisotropic initial stress conditions was investigated numerically. Not on the wall of opening but at a short distance from the wall, the tangential stresses were peak during the short period after excavation when the hydro-mechanical coupling is considered.

• Composites Research
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• v.25 no.4
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• pp.98-104
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• 2012

In recent years, degenerative spinal instability has been effectively treated with a cage. However, little attention is focused on the stiffness of the cage. Recent advances in the medical implant industry have resulted in the use of medical carbon fiber reinforced polymer (CFRP) cages. The biomechanical advantages of using different cage material in terms of stability and stresses in bone graft are not fully understood. A previously validated three-dimensional, nonlinear finite element model of an intact L2-L5 segment was modified to simulate posterior interbody fusion cages made of CFRP and titanium at the L4-L5 disc with pedicle screw, to investigate the effect of cage stiffness on the biomechanics of the fused segment in the lumbar region. From the results, it could be found that the use of a CFRP cage would not only reduce stress shielding, but it might also have led to increased bony fusion.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.662-668
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• 2004

Ames test revealed most methanol extracts of 13 Korean wild mushroom species have strong antimutagenic effects against N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and benzo(a)pyrene[B(a)P]. Methanol extracts of Coriolus versicolor and Phaeolepiota aurea showed 74-94 and 83-88% antimutagenic effects against MNNG and B(a)P in Salmonella typhimurium TA100 strain, while 89 and 91% inhibitions were observed against B(a)P in TA98 strain, respectively. Most water extracts of wild mushrooms did not show antimutagenic activeiy on MNNG and B(a)P. Wild mushrooms extracts inhibited human colon carcinoma cells (HT29), human hepatoma cell (HepG2), and humann histiocytic lymphoma cell (U937) dose-dependently, with most methanol extracts exhibiting stronger effect than water extracts, Highest toxicity was observed against HT-29 cells in methanol extracts of Coriolus versicolor and Phaeolepiota aurea, showing 84% inhibition at 1 mg/mL, whereas C. versicolor water extract showed 53-65% inhibition against HepG2 and U937. These extracts did not show cytotoxic effects against human lymphocyte. Results revealed wild mushrooms have strong antimutagenic and in vitro cytotoxic effects.

• Journal of Korean Society of Forest Science
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• v.89 no.3
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• pp.384-388
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• 2000

For the control of Corythucha ciliata, the insecticidal activity of five commercial pesticides (Monocrotophos 25%SL, Phosphamidon 50%SL, Imidacloprid 20%DC, Thiamethoxam 15%DC and Acetamiprid 20%SL) were examined with trunk injection method in Seoul, Sanbon and Chungju. The insecticidal activity of five commercial pesticides was >88%. The insecticidal activity of Monocrotophos maintained 31 days later after trunk injection when treated leaves were supplied to this pest. This result indicates that one application of trunk injection is enough to control this pest, and this method can save the control cost compared with ground application which should be applied two or three times per year to control this pest. To make the model of treatment dosage at each D.B.H class (cm), $1.0m{\ell}/DBH$, $1.5m{\ell}/DBH$ and $2.0m{\ell}/DBH$ pesticide dosage was used. At <20cm, the insecticidal activity of $1.0m{\ell}$ dosage was >95%, and $1.5-2.5m{\ell}$ dosage was needed for the effective control at 30~50cm. More than $2.5m{\ell}$ dosage was effective at >50cm. Spray method was used in laboratory to select pesticides for ground application. Three commercial pesticides (Ethofenprox 20%EC, Ethofenprox 10%WP and Cyfluthrin 1%EC) were used, and all pesticides showed >95% insecticidal activity.