• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2002년도 춘계학술대회 논문집
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• pp.185-190
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• 2002

It has made a special study of bending behavior of F.R.P sandwich beams with bonded 2nd-reinforced plies. Specimens were made of Chopped Mat 300-450, Roving Clothes 570 and the mixture weight ratio of Resin versus hardener was 55:45 for bending tests. it was fabricated by hand lay-up method, hardened for 24 hours in nature, cut specimens according to ASTM standard C393-94 Knowing exact behavior of bonded area's stress and strain depends upon various bonded F.R.P length on which covered lap joint. We also considered shear stress in adhered area and have done computational estimation by ANSYS as well. This study reveals that the length of plies covered lap joint are longer, Failure stresses are remarkably larger.

• 소음진동
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• 제7권3호
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• pp.439-447
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• 1997

In this study, the dynamic instabilities of a nonlinear elastic system subjected to follower forces are investigated. The two-degree-of-freedom double pendulum model with nonlinear geometry, cubic spring, and linear viscous damping is used for the study. The constant, the initial impact forces acting at the end of the model are considered. The chaotic nature of the system is identified using the standard methods, such as time histories, power density spectrum, and Poincare maps. The responses are chaotic and unpredictable due to the sensitivity to initial conditions. The sensitivities to parameters, such as geometric initial imperfections, magnitude of follower force, direction control constant, and viscous damping, etc., are analysed. Dynamic buckling loads are computed for various parameters, where the loads are changed drastically for the small change of parameters.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.685-689
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• 2004

Numerical simulation is conducted to clarify the heat transfer and fluid flow characteristics of HVAC(Heating, Ventilating and Air-Conditioning) for double' deck train. The HVAC system is installed under the roof of carbody. In the lay-out of HVAC system, air duct must be installed to supply air to 1st and 2nd floor respectively. The standard k-$\epsilon$ and LES models for turbulence and SIMPLE algorithm for pressure equation hased on finite volume method are used to solve the physic a] HVAC model. To assure convergence, QUICK scheme for momentum equation and the 2nd order upwind scheme for turbulent equations arc used. From the results of simulation, the temperature and velocity magnitude are also distributed uniformly in the interior of double-deck passenger car.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 춘계학술발표대회 논문집
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• pp.215-220
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• 2008

This study shows the results on thermal performance test with domestic solar collector for low-temperature applications using KS, then reveals the efficiency difference between KS and EN standard. Using the test results, this study presents the status of thermal performance with domestic solar collector including flat-plate, single evacuated, and double evacuated (with mirror or U-tube) solar collector.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권1호
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• pp.296-308
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• 2015

Advanced Encryption Standard (AES) is widely used for protecting wireless sensor network (WSN). At the Workshop on Cryptographic Hardware and Embedded Systems (CHES) 2012, G$\acute{e}$rard et al. proposed an optimized collision attack and break a practical implementation of AES. However, the attack needs at least 256 averaged power traces and has a high computational complexity because of its byte wise operation. In this paper, we propose a novel double sieve collision attack based on bitwise collision detection, and an improved version with an error-tolerant mechanism. Practical attacks are successfully conducted on a software implementation of AES in a low-power chip which can be used in wireless sensor node. Simulation results show that our attack needs 90% less time than the work published by G$\acute{e}$rard et al. to reach a success rate of 0.9.

• 한국환경과학회지
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• 제26권1호
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• pp.11-21
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• 2017

In this study, bacterial growth was assessed by flow cytometry analysis of fluorescent probes-stained bacteria. Flow cytometry has many advantages of rapid analytical time, a low standard deviation, and highly sensitive detection of live and Dead E.coli over colony forming assay. When untreated bacteria were stained by using Thiazole Orange (TO) and Propidium Iodide (PI), double staining had a short analytical time as compared with that of single staining while its error rate was similar to that of single staining. Through double staining experiments, it was determined that optimal concentrations for TO and PI staining were 420 nM and $9.6{\mu}M$, respectively.

• 치과방사선
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• 제10권1호
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• pp.35-40
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• 1980

The purpose of this survey was to reveal a incidence of dens invaginatus in the max. illary incisor region. The material was 1671 sets of full mouth intraoral standard films, which was taken from the patients visiting for the routine check at the Infirmary of College of Dentistry, Kyung Hee University. The following results were obtained; 1. The incidence of dens invaginatus was 14.90 and that of slightly dilated dens invaginatus was 9.46%. 2. The incidence of dens invaginatus showed no difference between male and female. 3. Most of the dens invaginatus occurred in the maxillary lateral incisors (93.53%) and a few in the maxillary central incisors (6.46%) showed slight invagination. 4. Among the cases with dens invaginatus, over a half (53.4l%) showed bilateral occurrence. 5. Comparatively rare cases, i.e. bilateral dens invaginatus of the maxillary central incisors, unilateral double dens invaginatus of the maxillary lateral incisor, and bilateral dens invaginatus of the maxillary lateral incisors, one side double and one side single, were reported.

• 한국작물학회지
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• 제46권5호
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• pp.345-347
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• 2001

This study was conducted to evaluate the effect of insecticides on control of Spodoptera exigua, growth characteristics, and dry root yield in the cultivation of Alisma plantago after early maturing rice cropping. All pesticides treated had no effect on growth and flowering rate of Alisma plantago. The major insecticides were teflubenzuron Wp, 5%, tebufenozide Wp, 8%, iufenuron Ec, 5%, and tebufenozide Wp, 5%. Dry root yield were increased largely with tebufenozide Wp, 5%(20 g/20 l), insecticide than the other insecticides and no control. All insecticides had no injury with standard dosage. On the other hand, all insecticides had slight injury in the double dosage level for the Alisma plantago.

• 센서학회지
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• 제21권1호
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• pp.7-12
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• 2012

In this paper, we propose a 4-transistor active pixel sensor(APS) with a novel correlated double sampling(CDS) circuit for the purpose of extending dynamic range. Dual sampling techniques can overcome low-sensitivity and temporal disparity problems at low illumination. To accomplish this, two images are obtained at the same time using different sensitivities. The novel CDS circuit proposed in this paper contains MOS switches that make it possible for the capacitance of a conventional CDS circuit to function as a charge pump, so that the proposed APS exhibits an extended dynamic range as well as reduced noise. The designed circuit was fabricated by using $0.35{\mu}m$ 2-poly 4-metal standard CMOS technology and its characteristics have been evaluated.

• 한국작물학회지
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• 제46권5호
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• pp.348-351
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• 2001

This study was conducted to evaluate the control effect of fungicides on control of brown leaf blight, growth characteristics, and dry root yield in the cultivation of Alisma plantago after early maturing rice cropping. All fungicides treated had no effect on the growth and flowering rate of Alisma plantago. The major fungicides were mancozeb Wp, 75%, chlorothalonil Wp, 75%, dithianon Wp, 43%, difenoconazole Wp, 10%, benomyl Wp, 50%, and propineb Wp, 70%. Dry root of yield were increased largely with chlorothalonil Wp, 75%(33 g/20), fungicide than the other fungicides and control. All fungicides had no injury with standard dosage. On the other hand all fungicides had slight injury in the double dosage level for the Alisma plantago.