• Macromolecular Research
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• 제12권4호
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• pp.391-398
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• 2004

Thick-film photolithography is a new technology that combines lithography processes, such as exposure and development, with the conventional thick-film process applied to screen-printing. In this study, we developed a low-temperature cofireable silver paste applicable for thick-film processing to form fine lines using photolitho-graphic technologies. The optimum paste composition for forming fine lines was investigated. The effect of processing parameters, such as the exposing dose, had on the fine-line resolution was also investigated. As the result, we found that the type of polymer and monomer, the silver powder loading, and the amount of photoinitiator were the main factors affecting the resolution of the fine lines. The developed photoimageable silver paste was printed on a low-temperature cofireable green sheet, dried, exposed, developed in an aqueous process, laminated, and then fired. Our results demonstrate that thick-film fine lines having widths < 20 $\mu\textrm{m}$ can be obtained after cofiring.

• 대한기계학회논문집B
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• 제31권12호
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• pp.1024-1032
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• 2007

The flow characteristics with the impinging angles of defrost nozzle jet inside a commercial vehicle passenger compartment were investigated experimentally by using the two-dimensional duct-nozzle model. The shape of the nozzle contraction was designed according to the curved line of cubic equation to the vertical plan of the flow direction. The impinging angles, defined as the angle between nozzle axis and a vertical line to the windshield, were varied from the $0^{\circ}\;to\;80^{\circ}$. The mean velocity distributions, the half-widths, and the momentum distributions with the cases of both the free jet and the impinging jet onto the dummy windshield were measured. The impinging jet flows similarly with wall jet from $X/b_o=20$, and the impinging angle has an effect on the half-width of the impinging jet. The momentum distributions onto the windshield increased with the increase of impinging angle, and then their inflection point was observed around the impinging angle of $60^{\circ}$.

• 한국표면공학회지
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• 제51권6호
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• pp.387-392
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• 2018

Nanopatterning is one of the essential nanotechnologies to fabricate electronic and energy nanodevices. Therefore, many research group members made a lot of efforts to develop simple and useful nanopatterning methods to obtain highly ordered nanostructures with functionality. In this study, in order to achieve pattern formation of three-dimensional (3D) hierarchical nanostructures, we introduce a simple and useful patterning method (nano-transfer printing (n-TP) process) consisting of various linewidths for diverse materials. Pt and $WO_3$ hybrid line structures were successfully stacked on a flexible polyimide substrate as a multi-layered hybrid 3D pattern of Pt/WO3/Pt with line-widths of $1{\mu}m$, $1{\mu}m$ and 250 nm, respectively. This simple approach suggests how to fabricate multiscale hybrid nanostructures composed of multiple materials. In addition, functional hybrid nanostructures can be expected to be applicable to various next-generation electronic devices, such as nonvolatile memories and energy harvesters.

• 천문학회보
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• 제43권2호
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• pp.58.2-58.2
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• 2018

Theoretically, the magnetic helicity transport flux through the solar surface into the upper atmosphere can be estimated indefinitely precisely by magnetic field footpoint tracking if the observational resolution is infinitely fine, even with magnetic flux emergence or submergence. In reality, the temporal and spatial resolutions of observations are limited. When magnetic flux emerging or submerging, the footpoint velocity goes to infinity and the normal magnetic field vanishes at the polarity inversion line. A finite observational resolution thus generates a blackout area in helicity flux estimation near the polarity inversion line. It is questioned how much magnetic helicity is underestimated with a footpoint tracking method due to the absence of information in the blackout area. We adopt the analytical models of Gold-Hoyle and Lundquist force-free flux ropes and let them emerging from below the solar surface. The observation and the helicity integration can start at different emerging stages of the flux rope, i.e., the photospheric plane initially cuts the flux rope at different levels. We calculate the magnetic helicity of the flux rope below the photospheric level, which is eventually to emerge, except the helicity hidden in the region to be swept by the blackout area with different widths. Our calculation suggests that the error in the integrated helicity flux estimate is about half of the real value or even larger when small scale magnetic structures emerge into the solar atmosphere.

• 천문학회보
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• 제46권2호
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• pp.36.1-37
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• 2021

Six images of IRC+10216 taken by the Hubble Space Telescope at three epochs in 2001, 2011, and 2016 are compared in the rest frame of the central carbon star. An accurate astrometry has been achieved with the help of Gaia Data Release 2. The positions of the carbon star in the individual epochs are determined using its known proper motion, defining the rest frame of the star. In 2016, a local brightness peak with compact and red nature is detected at the stellar position. A comparison of the color maps between 2016 and 2011 epochs reveals that the reddest spot moved along with the star, suggesting a possibility of its being the dusty material surrounding the carbon star. Relatively red, ambient region is distributed in an Ω shape and well corresponds to the dusty disk previously suggested based on near-infrared polarization observations. In a larger scale, differential proper motion of multiple ring-like pattern in the rest frame of the star is used to derive the average expansion velocity of transverse wind components, resulting in ~12.5 km s-1 (d/123 pc), where d is the distance to IRC+10216. Three dimensional geometry is implied from its comparison with the line-of-sight wind velocity determined from half-widths of submillimeter emission line profiles of abundant molecules. Uneven temporal variations in brightness for different searchlight beams and anisotropic distribution of extended halo are revisited in the context of the stellar light illumination through a porous envelope with postulated longer-term variations for a period of 10 years.

• 한국전자파학회논문지
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• 제9권5호
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• pp.630-639
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• 1998

본 논문에서는 T-모양의 마이크로스트립 급전 구조는 슬롯의 폭 변화에도 임피던스 정합이 쉽게 이룰 수 있는 방법을 제시하였다. 그리고 슬롯 안테나의 대역폭은 슬롯 폭에 비례하여 확장되는 특성을 얻었다. 여기서 제시한 급전 구조는 방사저항이 낮은 값으로 일정하게 유지되어 슬롯 폭과 거의 무관한 좋은 특성을 얻었다. 그리고 FDTD법을 사용하여 T-모양 급전선으로 여기된 슬롯 안테나를 모델링하여 파의 진행 과정과 전계분포를 시간영 역에서 각각 계산하였다. 그리고 FDTD법올 사용하여 얻은 값들을 Fourier 변환하여 최적화된 슬롯 안테나의 반사손실, 입력 임피던스, 복사 패턴을 주파수 영역에서 계산하였다. 이러한 결과로부터 최적의 안테나를 셜계 및 제작하였고, 슬롯폭이 16mm일때 약 35% 정도의 우수한 대역폭올 얻었으며, 이 계산값들은 측정치들과 비교적 잘 일치하는 특성을 얻었다.

• 복식문화연구
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• 제25권1호
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• pp.64-74
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• 2017

The purpose of this study is to identify the sensibility images when the direction and width of stripes change on semi-tight skirts. The researcher made 12 stimuli consisting of images of skirts with a combination of six stripe directions and two stripe widths. The images were assessed by 126 subjects who were students majoring in apparel. Three sensibility image factors were found: personality, attractiveness, and activity. Images of skirts with different stripe directions were perceived as having significant differences among these factors. Stripe widths of 1.5cm and 3cm in upward diagonal, vertical side line, and downward diagonal directions influenced the personality factor. Diagonal stripes with a width of 1.5cm positively influenced attractiveness and activity. Stripes in a vertical direction increased attractiveness when the stripe width was 1.5cm rather than 3cm. Although the interaction of stripe direction and width significantly influenced perceptions of attractiveness and activity in images of semi-tight skirts, they did not significantly influence personality. In accordance with the analysis, stripe direction was significantly different for all factors. This analysis indicated that each factor has its own independent influence. Stripe width had major independent effects, showing significance in attractiveness and activity. However, personality did not indicate any significant difference. The results of this study will help women select suitable clothing according to their individual preferences and body shapes by influencing how images are depicted because women will be able to use the images to estimate their body images when the skirts are put on.

• 복식문화연구
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• 제17권2호
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• pp.203-215
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• 2009

The purpose of this study was to investigate current garment sizes of women's formal jackets, targeting plus-size women in online shopping malls, and to identify effective size information involved in online apparel purchase behaviors to overcome the short comings of current garment sizes from the perspectives of consumers. Basic 88 size formal jackets from the seven companies found on the 22 websites were collected and analyzed. The data were collected from March to October 2007, and analyzed using SPSS 14.0. The results were summarized as follows. First, there was no website using standard garment size labeling with 'bust-hip-height' set up by KS K 0051 among the 22 websites. Instead, all 22 websites used garment size labeling with figures such as 88, 99, 100, 110, and 120 or with letters such as L, XL, and XXL. The websites presented no body size, but listed garment size. Furthermore, the size information was presented differently, ranging from three items of bust circumference, upper arm length, and jacket length to six items of shoulder width, bust circumference, waist circumference, sleeve width, sleeve length, and jacket length. In addition, no website presented basic information for hip circumference, despite the jacket length covering the hips. Second, a total of 85.7% the websites listed bust circumferences in 88 garment sizes collected as 100cm. Shoulder widths were presented as 39cm or 37cm. Sleeve circumferences were addressed the same, 36cm, in all websites. Third, comparing the differences between guidance sizes and measurement sizes, only 28.5% of the web sites posted guidance sizes of shoulder widths the same as those of the measurement sizes. All web sites presented guidance sizes of bust circumstances as 1 to 5cm smaller than those of the measurement sizes.

• 한국응용곤충학회지
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• 제30권1호
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• pp.54-57
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• 1991

파밤나방 유충을 실내에서 5세대 동안 인공사육하여 탈피할 때마다 두폭의 최대치를 측정하여 영기별 생장율을 구한 결과 2령 유충의 생장율은 1.43 이었고, 3령은 1.55, 4령은 1.48, 5령은 1.54, 6령은 1.76이었다. 한편 두폭 평？치의 대수를 Ycnr, 령의 수를 X축으로 하여 회귀직선식을 구한 결과 LogY=-0.819+0.1872X($r^{2}$=)었고 Dyar의 법칙과 동일한 기하급수적 생장을 하였다. 각영기별 두폭의 평균치와 Dyar의 법칙과 적합도는 1령 유충이 94.7%, 2령은 98.3, 3령은 98.7, 5령은 94.6 6령은 92.2%었다. Dyar의 항수 (K)는 1.54였다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 춘계학술대회 논문집
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• pp.371-374
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• 2007

A method for metal nano powder imprinting is proposed as a patterning process for conductive tracks that is inexpensive and scalable down to the nanoscale. Conductive tracks with line widths of $0.5{\sim}20{\mu}m$ were fabricated using this method. The processing conditions were optimized to avoid various types of defects, and to increase the degree of sintering and electric conductivity of the imprinted conductive tracks. The mean electric resistivity of the conductive tracks imprinted under optimum conditions was $8.95{\mu}{\Omega}{\cdot}cm$, which is in the range required for practical applications.