• Journal of Information Display
• /
• 제13권1호
• /
• pp.51-54
• /
• 2012

In this study, the bias-temperature stress and current-temperature stress induced by the electrical stabilities of half-Corbino hydrogenated-amorphous-silicon (a-Si:H) thin-film transistors (TFTs) with different gate electrode geometries fabricated on the same substrate were examined. The influence of the gate pattern on the threshold voltage shift of the half-Corbino a-Si:H TFTs is discussed in this paper. The results indicate that the half-Corbino a-Si:H TFT with a patterned gate electrode has enhanced power efficiency and improved aperture ratio when compared with the half-Corbino a-Si:H TFT with an unpatterned gate electrode and the same source/drain electrode geometry.

• 전자공학회논문지A
• /
• 제32A권1호
• /
• pp.61-69
• /
• 1995

a numerical method to the problem of mutual admittance between two slots is considered by use of conservation of complex power. Calculation of mutual admittance is compared with other results. And mutual admittance obtained by the method is used in the analysis for the broadband rectangular microstrip antenna geometry using E0plane gap coupling. The theoretical results for both return loss and radiation pattern of the broadband antenna are compared with experimental results. Good agreement between calculated and measured values has been observed.

• ETRI Journal
• /
• 제42권3호
• /
• pp.420-432
• /
• 2020

The reconstruction of archaeological fragments in 3D geometry is an important problem in pattern recognition and computer vision. Therefore, we implement an algorithm with the help of a 3D model to perform reconstruction from the real datasets using the slope features. This approach avoids the problem of gaps created through the loss of parts of the artifacts. Therefore, the aim of this study is to assemble the object without previous knowledge about the form of the original object. We utilize the edges of the fragments as an important feature in reconstructing the objects and apply multiple procedures to extract the 3D edge points. In order to assign the positions of the unknown parts that are supposed to match, the contour must be divided into four parts. Furthermore, to classify the fragments under reconstruction, we apply a backpropagation neural network. We test the algorithm on several models of ceramic fragments. It achieves highly accurate results in reconstructing the objects into their original forms, in spite of absent pieces.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2010년 춘계학술대회논문집
• /
• pp.67-70
• /
• 2010

Spandex yarn requires a twisting process during winding and unwinding processes at the textile industry. The air-twist nozzle is widely used as part of the winding and unwinding. This paper describes computational approach to design the geometry of the air-twist nozzle. The nozzle has circular yarn-channel and the air-inlet which is perpendicularly connected to the yarn-channel with yarn-loading slit. The air-inlet of the nozzle is designed while measurements of the yarn-channel are fixed. The airflow inside the air-twist nozzle is simulated by using Computational Fluid Dynamic model. The Ansys CFX was used to perform steady simulations of the airflow for the air-twisting process. The vortical structure and the airflow pattern such as velocity streamline, vorticity, velocity of the air-twist nozzle are discussed. Computational results are compared with experimental results in this paper.

• 전기학회논문지
• /
• 제62권12호
• /
• pp.1719-1724
• /
• 2013

In this paper, a size-reduction technique is presented for the RFID reader antenna working at two UHF bands. To tackle the problem of size increase in multi-band applications, two resonance paths are made to occur in one geometry with a single feed. While one resonance path is combined with the other, the entire geometry is determined to guarantee the resonance at the target frequencies through the dual-band input impedance matching. The antenna performance is predicted by the full-wave simulation, and the design method is verified by observing the good agreement between the simulated and measured results. At the two frequencies, the satisfactory return loss as well as the antenna efficiency and peak gain of the far-field pattern is obtained.

• 한국진공학회지
• /
• 제2권2호
• /
• pp.171-180
• /
• 1993

X-선 광전자 분광법(XPD)을 이용하여 GaAs(110) 절개면의 결정구조를 이해하였다. 각분해 X-선 분광법으로 GaAs(110) 면의 내각준위 Ga 및 As 3d의 스펙트럼을 얻어, 이 내각 준위의 세기 비율(intensity ratio)의 방위각과 편각에 따른 변화를 SSC(Single Scattering Cluster) 모델에서 얻은 회절패턴으로 곡선분석(fitting)하여 절개면의 재구성 구조(reconstruction geometry)를 얻었다. 이 절개면의 재구성된 값은 다른 실험의 결과와 비슷하였다.

• 대한수학교육학회지:수학교육학연구
• /
• 제9권1호
• /
• pp.121-132
• /
• 1999

We have compared Korean and American mathematics curriculums in 5 areas: whole number(concepts and its operations); geometry; pattern and relations; measurements; statistics and probability. We have found significant differences in geometry area. Korean curriculums contain simple planar figures (circles, triangles, rectangles, and squres) and some of the spatial figures until 3rd grades. But in America they learn various planar and spatial fugures(cone, pyramid, triangular prism, etc) since the 1st grade starts. They also start the 1st grade by dealing with topological concepts like open/closed, inside/outside, order, etc. As the grade goes on, students learn other geometrical concepts like congruence, symmetry, 3-dimensional views. We also found that American curriculum focuses on students' activities and courages communication through projects, groupwork, journal writing, etc. It's also superior in respects of motivation, and connections with real life and other subjects. Korean curriculum needs more improvements in these aspects. Furthermore for lower graders reviewing sections need to be enhanced for feedback.

• 인터넷정보학회논문지
• /
• 제11권5호
• /
• pp.27-35
• /
• 2010

본 논문에서는 평면 스크린을 사용할 수 없는 휴대형 프로젝터의 사용 환경에서 평면이 아닌 임의의 영사면(혹은 벽면)의 기하학적 형태에 의해 발생되는 영상의 기하학적 왜곡을 효과적으로 보정할 수 있는 방법을 제안한다. 제안한 방법에서는 먼저 격자패턴을 임의의 영사면에 영사한 후 영사면의 형태에 따라 왜곡된 격자패턴과 원본 격자패턴 간의 기하학적 관계를 나타내는 직선의 방정식을 도출한다. 다음으로 영사면의 기하학적 형태에 따라 적절하게 적용될 수 있는 원본 격자패턴의 크기를 결정하여 도출된 직선의 방정식으로부터 왜곡된 영상을 대칭적으로 보정할 수 있는 보정패턴을 생성한다. 최종적으로 프로젝터로부터 영사될 실제 영상을 격자패턴과 동일하게 분할하여 보정패턴에 맞게 미리 워핑(warping)함으로써 영사된 영상의 기하학적 왜곡을 보정한다. 제안한 방법의 성능 평가를 위하여 평면 스크린을 사용할 수 없는 영사 환경에서 자주 접할 수 있는 영사면 형태들인 기울어진 평면, 꺾인 평면 및 곡면을 대상으로 영사 영상 보정에 대한 실험을 진행하였다. 실험결과로부터 일반적으로 발생하는 몇 가지 영사면의 형태들에 인한 기하학적 왜곡들이 적절히 보정되어 제안한 방법이 영사 영상의 기하학적 왜곡을 매우 효과적으로 보정할 수 있음을 알 수 있었다.

• 한국실내디자인학회논문집
• /
• 제20권2호
• /
• pp.120-130
• /
• 2011

The purpose of this study is to propose cognitive ecological effects of fractal patterns in space design. This study investigated the perception and cognition problems regarding landscape patterns showing fractal properties from the cognitive perspective instead of the traditional speculative approach. In particular, the researcher has verified that fractal geometry theory and fractal pattern concept provide insight in space aesthetic values and cognitive effects. Research results are as follows. First, most environmentally-friendly fractal urban forms provide cognitive connectivity. In particular, this space provides a positive emotional response and preference to humans and displays self-organized complexity. This study found that such complexity of space form has characteristics corresponding to parallel cognitive structures of the human brain. Simultaneously, the researcher suggests that the fractal landscape pattern is an alternative for stiff and homogenized modern space. Second, fractal patterns provide hierarchical connectivity within the brain through continuous difference and repetition. In particular, self-similarities of fractal patterns administer significant visual grouping and coherence in human perception. It can be determined whether scaling coherence facilitates easier organization in cognitive organization. Third, fractal patterns in space design provide the basic method for achieving the connection between concept, construction, and urban factors. As a result, the researcher has suggested that scale distribution of geometrical factors, such as fractal patterns, an be a design method to connect various space typologies.

• 복식
• /
• 제51권8호
• /
• pp.1-12
• /
• 2001

An empirical review on silk fabrics of the Chosen period showed that they varied in kind and design according to their uses. Thus the purpose of this study is to classify the fabrics into temple and excavated fabrics according to their uses and collected places and then to examine characteristics of each type. Concerning fabrics collected in temples. satin was most used, followed by twill, tabby, multiply, leno and gauze and clossing fabrics in order. Tabby and silk fabrics used Ju(紬) as their main material. Cho( ) was much more used in fabrics collected in temples than in excavated ones. This indicate that Cho( ), more luxurious than Ju(紬), had divine applications such as covering Buddha s bones of temples. Brilliant, colorful multiply fabrics using goldern and color threads had high effects of ornamenting altar covers, umbrellas, surplices and palanquins. Fabrics held in temples adapted composite designs, in which more than two shapes were used, rather than single ones. Single designs employed plant shapes in most cases. followed by treasures pattern, geometrical, cloud and animal shapes in order. Most composite designs used a combination of animal and plant shapes, followed by plant and geometry, treasures pattern and plant, cloud and animal, and animal, treasures pattern and plant in order. Few excavated fabrics used animal designs while fabrics collected in temples were often designed with shapes of propitious animals such as dragon. Treasures pattern. representing a good omen of Buddhism, was often used sing1y or sometimes compositely with another design.nother design.