• Structural Engineering and Mechanics
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• 제58권1호
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• pp.121-142
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• 2016

The national standard being used in Turkey for suspended ceiling systems (SCS) regulates material and dimensional properties but does not contain regulations regarding installation instructions which cause substandard applications of SCSs in practice. The lack of installation instructions would potentially affect the dynamic performance of these systems. Also, the vast majority of these systems are manufactured using substandard low-quality materials, and this will inevitably increase SCS related damages during earthquakes. The experimental work presented here focuses on the issue of dynamic performance of SCSs with different types of carrier systems (lay-on and clip-in systems), different weight conditions, and material-workmanship qualities. Moreover, the effects of auxiliary fastening elements, so called seismic perimeter clips, in improving the dynamic performance of SCSs were experimentally investigated. Results show that clip-in ceiling system performs better than lay-on system regardless of material and workmanship qualities. On the other hand, the quality aspect becomes the most important parameter in affecting the dynamic performance of lay-on type systems as opposed to tile weights and usage of perimeter clips. When high quality system is used, tile weight does not change the performance of lay-on system, however in poor quality system, tile weight becomes an important factor where heavier tiles considerably decrease the performance level. Perimeter clips marginally increase the dynamic performance of lay-on ceiling system, but it has no effect on the clip-in ceiling system under the shaking levels considered.

• 해양환경안전학회지
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• 제17권3호
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• pp.185-189
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• 2011

본 연구는 낙동강 하구역의 사주지형 변화를 예측하기 위한 기초적 연구로서 하천유량의 변화에 따른 부유사의 물질수지에 대하여 검토하였다. 낙동강 하구역의 부유사 물질수지는 갈수기시 60,708 kg/day가 유입하고, 홍수기는 306,892 kg/day가 외해를 통하여 유출하는 것으로 산정되었다. 낙동강 하구역은 전반적으로 갈수기 및 평수기에 부유사의 유입, 홍수기에 부유사의 유출이 반복 되지만, 사주지형 주변에서는 부유사의 유입과 유출 거동이 복잡하게 나타나 장기 지형변동 모니터링이 필요한 것으로 나타났다.

• 한국해안해양공학회지
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• 제14권3호
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• pp.222-231
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• 2002

ADP는 음향의 Doppler효과를 이용하여 층별 유속과 유향을 측정하는 장비이며, 최근에는 반사음향의 강도로부터 부유 퇴적물의 농도측정이 가능하다고 제기되고 있다. 본 연구에서는 염산 인근의 한 정점에 ADP 기기를 설치하고 자료를 수집하였다. 부유사 농도를 분석하기 위하여 해수 분석을 통한 음향계수를 정한 후 보정된 음향강도를 이용하여 부유사 농도를 구하였다. 관측된 부유사 농도분포 식은 해석해와 비교하였으며, 농도변화의 경향에 대해서는 비교적 양호한 결과를 나타냈다. 또한, 관측기간 동안의 부유물질의 이동량에 대한 정량적 결과를 얻었으며 ADP를 활용한 연직방향의 부유입자 농도변화를 관측할 수 있음을 보였다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2002년도 학술발표회 논문집(II)
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• pp.1047-1050
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• 2002

• Transactions on Electrical and Electronic Materials
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• 제4권3호
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• pp.19-24
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• 2003

The experimental and simulation study of insulator failure by cement growth on suspended insulators (16,500kgf) for transmission line was discussed. To get more practical and analytic calculation results, the advanced program was used. This analysis tool was possible to calculate stress behaviors with mechanical loading when cement displacement happened. From simulation results, the. cement displacement changed with linear according to temperature. The shear stress was about $7 kgf/mm^2$ at $0.07\%$ displacement provided from $200^{\circ}C$, then it could be seen that the cement would be fractured even if $0.07\%$ displacement acted, because the cement had about $7-9 kgf/mm^2$ flexure strength. The curve patterns of shear stress with the increase of mechanical loading were changed at $0.02\%$ as a turning point, when the cement displacement was over $0.02\%$ the shear stresses decreased reversely with the increase of mechanical loading. From analysis on porcelain body it was known that there were enough margin to protect the fracture of porcelain body before the cement

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.252-252
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• 2008

The microhotplates consisting of a Pt-ased heating element on AlN/poly 3C-SiC layers were fabricated. The microhotplate has a $600{\mu}m{\times}600{\mu}m$ square shaped membrane which made of $1{\mu}m$ thick ploycrystalline 3C-SiC suspended by four legs. 3C-SiC is known for excellent chemical durability, mechanical strength and sustaining of high temperature. The membrane is fabricated by surface micromachining using oxidized Si sacrificial layer. The Pt thin film is used for heating material and resist temperature sensor. The fabrication methodology allows intergration of an array of heating material and resist temperature detector. For reasons of a short response time and a high sensitivity a uniform temperature profile is desired. The dissipation of microhotplate was examined by a IR thermoviewer and the power consumption was measured. Measured and simulated results are compared and analyzed. Thermal characterization of the microhotplates shows that significant reduction in power consumption was achieved using suspended structure.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1312-1314
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• 2007

The effect of gate insulator surface treatment on electrical characteristics of bottom contact (BC) and suspended source/drain (SSD) organic thinfilm transistors (OTFTs) was studied. Triisopropylsilylethynyl pentacene was used as an active material and was printed by ink-jet printing method. In case of the BC OTFTs, threshold voltage was shifted from positive to near zero, and the fieldeffect mobility was increased when the gate insulator surface was treated with hexamethyldisilazane. However, in case of SSD OTFT, threshold voltage shift was not observed and the field-effect mobility was decreased.

• 물과 미래
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• 제23권1호
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• pp.119-127
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• 1990

점착성 부유사 농도분포는 해수유동과 물질 확산에 의해서 결정되며 지배방정식으로는 2차원 수심적분된 Reynolds운동방정식, 연속방정식과 Fick의 확산법칙에 근거를 둔 대류-확산방정식이 사용되었다. 해수유동과 점성퇴적물 확산인 두개의 모형은 유한차분법을 이용하였고 유동모형은 양해법, 확산모형은 다증법을 사용하여 부유사 이동의 현상을 파악하였다. 해수유동방정식의 적용시 이송항의 포함여부에 대해서 조사하였으며 물질확산 방정식에 대해서는 한계전단응력값의 변화가 부유사농도에 영향을 주는가에 대해서 비교하였다.

• Journal of the korean society of oceanography
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• 제31권2호
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• pp.55-63
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• 1996

Distribution of suspended particulate matter, dissolved oxygen and major inorganic nutrients along a meridional section ($126^{\circ}$ 33' E) in the Cheju Strait is described along with the hydrographic and current data obtained during April 25-27, 1995. The current measurements was conducted using a vessel-mounted Acoustic Doppler Current Profiler (ADCP). Repeated coverage along an ADCP transect during 25 hours allows to calculate the daily mean along- and cross-strait currents. Measured material concentrations and the mean current speed were used to estimate the flux density (cencentration times current speed) of materials. Two types of depth distibution of flux densities were observed. for nitrate and suspended particulate matter, the depth distribution pattern of materials determines those of flux densities. However, flow patterns determine those of flux densities for dissolved oxygen, phosphate and silicic acid. The total along-strait water volume transport is about 0.3 Sv (1Sv $10^{6}$ $m^{3}/s^{-1}$). The total along-strait material transports are estimated to be 3.1 $${\times} $10^{5}$ $g/s^{-1},$ 2.4 ${\times}$ $10^{6}\;g/s^{-1},$ 7.I ${\times}$ $10^{2}\;mol/s^{-1},$ 3.I ${\times}$ $10\;mol/s^{-1},$ 1.7 ${\times}$ $10^{3}\;mol/s^{-1}$ for suspended particulate matter, dissolved oxygen, nitrate ion, silicic acid and phosphate ion, respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 연구회
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• pp.59-61
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• 2001

Polymeric suspended insulators for the electric track line have been developed. The main elements to design polymeric insulators are the insulation ability related with materials of FRP core and housing, and the optimal structure related with fitting parts and interface characteristics. To confirm the design fitness of insulator samples the electric field distribution by FEM and mechanical stress distribution by NASTRAN program was analysed with housing shed shapes and fitting structure. The leakage distance and breakage voltage properties which are core parameters to determine electric insulation ability are selected according to the requirement values of user specification, then the power frequency wet withstand voltage was specified above 22kV and the leakage distance was required above 290mm. The contamination condition of the electric track line was the heavy class according to IEC 815 in order to retain the enough safety margin against overvoltages.