• 한국주조공학회지
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• 제31권5호
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• pp.288-292
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• 2011

In order to complement the drawbacks of quartz crucible such as fragile-like break and melt-leakage through open slit nozzle, a new PFC system has been developed using a common graphite crucible and plugging system. The u melt is fed on to the rotating a roll through slit nozzle by self-gravity. The new equipment was designed and manufactured successfully. An effort for optimizing all related parameter has been made. Then using the optimized parameters about 10 meters u foil having very thin thickness, which meets the target thickness of 130 ${\mu}m$ and enough width more than 60 mm could be made. The thickness homogeneity set improved, due to the lower eddy flowing of the melt flow the self-gravity feeding system.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.196.1-196.1
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• 2016

TCO(Transparent Conducting Oxide) on flat glass is used in thin-film photovoltaic cell, flat-panel display. Nowadays, Corning(R) Willow Glass(R), known as flexible substrate, has attracted much attention due to its many advantages such as reliable roll-to-roll glass processing, high-quality flexible electronic devices, high temperature process. Also, it can be an alternative to flexible polymer substrates which have their poor stability and degradation of electrical and optical qualities. For application on willow glass, the flexibility, electrical, optical properties can be greatly influenced by the TCO thin film thickness due to the inherent characterization of thin film in nanoscale. It can be expected that while thick TCO layer causes poor transparency, its sheet resistance become low. Also, rarely reports were focusing on the influence of flexible properties by varying TCO thickness on flexible glass. Therefore, it is very important to optimize TCO thickness on flexible Willow glass. In this study, Ti-ZnO thin films, with different thickness varied from 0 nm to 50 nm, were deposited on the flexible willow glass by atomic layer deposition (ALD). The flexible, electrical and optical properties were investigated, respectively. Also, these properties of Ti-doped ZnO thin films were compared with un-doped ZnO thin film. Based on the results, when Ti-ZnO thin films thickness increased, resistivity decreased and then saturated; transmittance decreased. The Figure of Merit (FoM) and flexibility was the highest when Ti-ZnO thickness was 40nm. The flexible, electrical and optical properties of Ti-ZnO thin films were better than ZnO thin film at the same thickness.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2004년도 추계학술발표대회 개요집
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• pp.150-152
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• 2004

This study was aimed at evaluation of residual stress of steel pipe structures. The production process of pipes was complex (at first bending was done by roll forming or press forming and welding was final process of making of steel pipes). So there could be effected high residual stresses in steel pipes. In order to evaluate the changes of residual stress the locations of measurement were selected carefully. Measurements of residual stress were done for various kinds of pipes (shapes in circular and square). For the evaluation of residual stress, hole-drilling method (ASTM E837 was applied. The results showed that along the weld Eine high tensile stress were measured as effected, and high tensile stresses were measured where large plastic deformation developed. Through these efforts, experimental results could be more effectively assisted by numerical method.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.277-281
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• 1997

Reliab~l~ty englneerlng IS regarded as the major and important roll for all Industry And advanced nianufactur~ng systems w~th h~gh speed and lntell~gent ha\\ulcorner been dcvelop~ng for betterment of lnachln~ng db~l~ty In th~study, Me have rystem~~ed c\, ~luat~on c r f relidb~litl for nldchlntry system We proposed the rel~ab~l~ty asvxmcnt and dci~yned and manufactured r~ildb~llty tcst-bed to eualuate rcl~dbil~ty In ddd~t~on we acquired relldb~l~ty data uslng test-bed sydem and mde database to handle relrab~l~t) data And also he not only use rel~ab~l~ty data by andlyzlng rel~ab~l~ty, but also apply design revlew method usmg analycing crltlcal unlt5 of machlnery system From th~s stud), he u ~ l l expect to gu~de md Increase the rel~ab~l~t) englneerlng in devclop~ng and procerslng phase of h~gh qualrty product

• 대한기계학회논문집B
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• 제22권12호
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• pp.1774-1783
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• 1998

The transition from steady laminar to chaotic convection in a glass melting furnace specified by upper surface temperature distribution has been studied by the direct numerical analysis of the two and three-dimensional time dependent Navier-Stokes equations. The thermal instability of convection roll may take place when modified Rayleigh number($Ra_m$) is larger than $9.71{\times}10^4$. It is shown that the basic flows in a glass melting furnace are steady laminar, unsteady periodic, quasi-periodic or chaotic flow. The dimensionless time scale of unsteady period is about the viscous diffusion time, ${\tau}_d=H^2/{\nu}_0$. Through primary and secondary instability analyses the fundamental unsteady feature in a glass melting furnace is well defined as the unsteady periodic or weak chaotic flow.

• 복식
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• 제50권2호
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• pp.15-28
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• 2000

This paper focuses on the sports look expressed in 20th century fashion. It is Age of Sport just as rock'n roll became dominant cultural form of the 1960's and 1970's . In the 1990's the sportsware is fashion. Designers gazing into the future are inspired by the details and functionality of clothing for snow boarding , skiing , motorbike racing and fitness. No doubt fashion in 2000 will also be full of references to it. Since the late 1960's the sportswear that was originally a term for clothing worn for various sports activities in the 1890's has changed and is now considered as fashion for day as well as evening. This has occurred primarily in the U.S. due to the adoption of less formal lifestyles by Americans. while the sportwear is the term which stemmed from the need for functionality in sports, sports look is the style inspired by the formative elements, that is, the details, the shilhouette, and the colors of the sportswear. New technologies for sports, the powerful influence of youthful culture, and the celebritizations of the sports stars made the sports look much hipper and more popular. It can be categoried into three aesthetic values, I. e., the functional sports look,, purism and no useless ornament, the street sports look with fun, androgynous and unisex mode and the mix and match of different texture and colors, and the futuristic sports look with new high tech fabrics and avant-garde style.

• 동력기계공학회지
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• 제15권5호
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• pp.16-21
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• 2011

The large scale decisive battle will be gradually reduced on the sea in the future and surface combatant ship installed advanced weapon units as well as propulsion system will be continuously increased. The high level of military technology leads to appear state-of-the-art weapon system using high power energy. As a results, fossil fuel powered main prime mover as diesel engine and gas turbine which are composed of mechanical propulsion system should be decreased from combatant ship in the near future. The new building naval combatant ship with the latest technology has electric based propulsion method of the hybrid type combined with mechanical and electrical drive. U.S. and Royal Navy, especially, select the integrated fully electric based propulsion system for the next generation combat ship and play an important roll for developing them. In this context, this paper was focused on the deduction of implications through analyzing the combatant ship propulsion system using diesel and gas turbine engine which are promoted on the worldwide.

• Bulletin of the Korean Chemical Society
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• 제29권10호
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• pp.1937-1940
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• 2008

The P1 duplex of Tetrahymena group I ribozyme is the important system for studying the conformational changes in folding of ribozyme. The formation of the P1 duplex between IGS and substrate RNA and the catalytic activity of ribozyme require a variety of metal ions such as $Mg^{2+}$ and $Mn^{2+}$. In order to investigate the effect of the $Mg^{2+}$ concentration on the conformation of the P1 duplex, the NMR study was performed as a function of $Mg^{2+}$ concentration. This study revealed that the less stable AU-rich region formed duplex at $50{^{\circ}C}$ under high $Mg^{2+}$ concentration condition but melts out under low $Mg^{2+}$ concentration condition. It was also found that in the active conformation under 10 mM $MgCl_2$ condition, the unstable central G${\cdot}$U wobble pair maintains the significant base pairing up to $50{^{\circ}C}$. This study provides the information of the unique feature of the P1 duplex structure and the roll of $Mg^{2+}$ ion on the formation of the active conformation.

• Journal of electromagnetic engineering and science
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• 제10권1호
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• pp.28-34
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• 2010

This paper introduces a new U.S. ultra-wideband(UWB: 3.1~10.6 GHz) 1:2 power divider based on a single section Wilkinson type configuration. The divider provides very flat in-band power splitting, high isolation, low insertion loss, sharp roll-off bandpass filtering, and DC blocking characteristics. The circuit consists of a $\lambda$/4 Y resonator, three capacitively coupled $\lambda$/2 short-circuited lines, and a resistor between the two output ports. The circuit structure was simulated with ADS and HFSS, and realized with low-temperature co-fired ceramic(LTCC) green tape, which has a dielectric constant of 7.8. $|S_{11}|$ better than 10 dB, $|S_{21}|$ and $|S_{31}|$ less than 3.2 dB, with both $|S_{22}|$ and $|S_{32}|$ measured as better than 12 dB for the whole UWB band. Measurement results agree closely with HFSS simulation results. The power divider has a compact size of $4\times9\times0.6mm^3$.

• Applied Microscopy
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• 제33권2호
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• pp.105-116
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• 2003

U. unicinctus 난세포를 인공수정한 결과 수정 시기는 germinal vesicle (2n)기였으며 정자 중앙부에서 돌출한 actomere와 난모세포의 미세융모 끝에서 세포막 융합이 시작되는 것으로 관찰되었다. Germinal vesicle기에 수정이 가능하였으므로 pre-mitotic spindle이 관찰되지 않은 것으로 사료되었다. 수정 후 난모세포는 제1, 2감수분열을 수행하였으며 각각의 감수분열 장치들은 감수분열 말기에 난모세포막과 밀접한 구조를 형성하였고, 이 부위에서 극체가 형성되는 것을 볼 수 있었다. 극체 형성시 난모세포막은 세포분열의 관점에서 형태가 없는 것이 아니라 항-튜블린-FITC에 대한 활성구조를 형성하였으며, 각 감수분열 장치의 한쪽 극 (pole)과 어떤 복합구조를 형성하는 것으로 보인다. 제2극체 형성도 제1극체와 유사한 방법으로 형성되었으나, 제2감수분열 장치는 난모세포막의 접선에 평행하게 생성된 후 세포막을 향해 이동하면서 방추사의 양극성이 회전 (shift-rotation)하였고 접선에 수직으로 정렬하는 것을 볼 수 있었다. 난모세포의 감수분열 장치에서 방추사의 활성은 강하였으나 aster의 활성은 비교적 약한 것으로 보였다. 제2감수분열이 진행되는 동안 난모세포질에 머믈고 있던 정자는 점차 미래의 자성 전핵 형성부인 난모세포막 근접부로 이동하는 것이 관찰되었다. 난모세포막 근접부로 이동하는 동안 정자 aster의 활성은 점차 강해지는 반면 난모세포의 aster에서는 활성이 미약한 것으로 보아서 자웅 전핵융합을 주도하는 것은 정자 유래의 aster인 것으로 사료되었다. 제1난모세포의 감수분열 장치가 활성화되는 시기에 제1극체의 방추사에서도 강한 활성을 관찰할 수 있었다.