• Title/Summary/Keyword: random texture

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Front-side Texturing of Crystalline Silicon Solar Cell by Micro-contact Printing (마이크로 컨텍 프린팅 기법을 이용한 결정질 실리콘 태양전지의 전면 텍스쳐링)

  • Hong, Jihwa;Han, Yoon-Soo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.11
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    • pp.841-845
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    • 2013
  • We give a textured front on silicon wafer for high-efficiency solar cells by using micro contact printing method which uses PDMS (polydimethylsiloxane) silicon rubber as a stamp and SAM (self assembled monolayer)s as an ink. A random pyramidal texturing have been widely used for a front-surface texturing in low cost manufacturing line although the cell with random pyramids on front surface shows relatively low efficiency than the cell with inverted pyramids patterned by normal optical lithography. In the past two decades, the micro contact printing has been intensively studied in nano technology field for high resolution patterns on silicon wafer. However, this promising printing technique has surprisingly never applied so far to silicon based solar cell industry despite their simplicity of process and attractive aspects in terms of cost competitiveness. We employ a MHA (16-mercaptohexadecanoic acid) as an ink for Au deposited $SiO_2/Si$ substrate. The $SiO_2$ pattern which is same as the pattern printed by SAM ink on Au surface and later acts as a hard resist for anisotropic silicon etching was made by HF solution, and then inverted pyramidal pattern is formed after anisotropic wet etching. We compare three textured surface with different morphology (random texture, random pyramids and inverted pyramids) and then different geometry of inverted pyramid arrays in terms of reflectivity.

An MRF-Based Texture Segmentation Using Genetic Algorithm (유전자 알고리즘을 이용한 MRF기반의 Texture분할)

  • Lee, Kyung-Mi;Kim, Sang-Kyoon;Kim, Hang-Joon
    • The Transactions of the Korea Information Processing Society
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    • v.5 no.10
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    • pp.2713-2724
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    • 1998
  • This paper proposes a new method for the parameter estimation in Markov Random Field(MRF) model of textured color images. The MRF models allow an image region to bel described using a finite number of parameters that characterize spatial interactionsl within and between bands of al color image. An important problem is estimation of the parameters since the randorn field model-based textured color image is the mostly parametric images of natural scenes to verify the validit of the proposed method proves that the method is not affected by the size of the image and shows well-segmented images.

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Quality Characteristics of Muffin Added with Rice Bran Powder (미강을 첨가한 머핀의 품질 특성)

  • Jang, Kyung-Hee;Kang, Woo-Won;Kwak, Eun-Jung
    • Journal of the East Asian Society of Dietary Life
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    • v.22 no.4
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    • pp.543-549
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    • 2012
  • Muffins were prepared with different amounts of rice bran powder (0~30%), and their quality characteristics were investigated. The specific gravity of batters increased with increasing rice bran. While the initial pasting temperature increased with increasing rice bran amount, peak viscosity and viscosity at $95^{\circ}C$ after 15 min gradually decreased. The pH value of batters and muffins decreased with increasing rice bran amount. Moisture content of muffins was affected by the addition of rice bran powder. The lightness and yellowness values of muffins decreased with increasing rice bran amount, whereas redness value increased. For textural characteristics, hardness, gumminess and chewiness of muffins significantly increased with increasing rice bran amount, whereas cohesiveness and springiness decreased. Aircell uniformity of muffins became larger and more random as rice bran powder content increased. In the sensory evaluation, scores of taste and texture were the highest in muffin added with 5% rice bran powder. Overall acceptability was highest in control and the 5% group without any significant difference. Values of color, flavor, taste, texture and overall acceptability of muffins tended to decrease as rice bran powder content increased.

Influence of Inverted Pyramidal Surface on Crystalline Silicon Solar Cells (결정질 실리콘 태양전지 표면 역 피라미드 구조의 특성 분석)

  • Yang, Jeewoong;Bae, Soohyun;Park, Se Jin;Hyun, Ji Yeon;Kang, Yoonmook;Lee, Hae-Seok;Kim, Donghwan
    • Current Photovoltaic Research
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    • v.6 no.3
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    • pp.86-90
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    • 2018
  • To generate more current in crystalline silicon solar cells, surface texturing is adopted by reducing the surface reflection. Conventionally, random pyramid texturing by the wet chemical process is used for surface texturing in crystalline silicon solar cell. To achieve higher efficiency of solar cells, well ordered inverted pyramid texturing was introduced. Although its complicated process, superior properties such as lower reflectance and recombination velocity can be achieved by optimizing the process. In this study, we investigated optical and passivation properties of inverted pyramid texture. Lifetime, implied-Voc and reflectance were measured with different width and size of the texture. Also, effects of chemical rounding at the valley of the pyramid were observed.

Boundary-adaptive Despeckling : Simulation Study

  • Lee, Sang-Hoon
    • Korean Journal of Remote Sensing
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    • v.25 no.3
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    • pp.295-309
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    • 2009
  • In this study, an iterative maximum a posteriori (MAP) approach using a Bayesian model of Markovrandom field (MRF) was proposed for despeckling images that contains speckle. Image process is assumed to combine the random fields associated with the observed intensity process and the image texture process respectively. The objective measure for determining the optimal restoration of this "double compound stochastic" image process is based on Bayes' theorem, and the MAP estimation employs the Point-Jacobian iteration to obtain the optimal solution. In the proposed algorithm, MRF is used to quantify the spatial interaction probabilistically, that is, to provide a type of prior information on the image texture and the neighbor window of any size is defined for contextual information on a local region. However, the window of a certain size would result in using wrong information for the estimation from adjacent regions with different characteristics at the pixels close to or on boundary. To overcome this problem, the new method is designed to use less information from more distant neighbors as the pixel is closer to boundary. It can reduce the possibility to involve the pixel values of adjacent region with different characteristics. The proximity to boundary is estimated using a non-uniformity measurement based on standard deviation of local region. The new scheme has been extensively evaluated using simulation data, and the experimental results show a considerable improvement in despeckling the images that contain speckle.

Effect of Interesterification for Increasing Creaming Power in Lard (라아드의 크림성 향상에 대한 에스테르교환의 효과)

  • Lim, Hye-Kyoung;Kim, Myoung-Ae
    • Korean Journal of Food Science and Technology
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    • v.25 no.6
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    • pp.730-735
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    • 1993
  • This study was performed in order to clarify whether the creaming power of lard could be improved by random interesterification. The physicochemical properties, solid fat content, consistency, and creaming power of fat, and sensory evaluation on cream were investigated. The temperature of SFC $5{\sim}30$ showed the wider range from $10^{\circ}C\;to\;33^{\circ}C$ in random interesterified lard than that from $16^{\circ}C\;to\;30^{\circ}C$ in lard. The consistency of random interesterified lard was gradually decreased as temperature was increased, and was about $2000g\;per\;cm^{2}$ at low temperature level below $10^{\circ}C$. The sensory evaluation at maximum over ruu indicated that texture, polish and solubility of the cream made with random interesterified lard was slightly lower than that with lard, but random interesterified lard greatly improved the viscosity and firmness of cream. As the result of this study, the creaming power of lard was increased by random interesterification. Especially, the random interesterified lard could be considered as the better fat materials used in winter cream.

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Efficient Methodology in Markov Random Field Modeling : Multiresolution Structure and Bayesian Approach in Parameter Estimation (피라미드 구조와 베이지안 접근법을 이용한 Markove Random Field의 효율적 모델링)

  • 정명희;홍의석
    • Korean Journal of Remote Sensing
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    • v.15 no.2
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    • pp.147-158
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    • 1999
  • Remote sensing technique has offered better understanding of our environment for the decades by providing useful level of information on the landcover. In many applications using the remotely sensed data, digital image processing methodology has been usefully employed to characterize the features in the data and develop the models. Random field models, especially Markov Random Field (MRF) models exploiting spatial relationships, are successfully utilized in many problems such as texture modeling, region labeling and so on. Usually, remotely sensed imagery are very large in nature and the data increase greatly in the problem requiring temporal data over time period. The time required to process increasing larger images is not linear. In this study, the methodology to reduce the computational cost is investigated in the utilization of the Markov Random Field. For this, multiresolution framework is explored which provides convenient and efficient structures for the transition between the local and global features. The computational requirements for parameter estimation of the MRF model also become excessive as image size increases. A Bayesian approach is investigated as an alternative estimation method to reduce the computational burden in estimation of the parameters of large images.

Near-lossless Coding of Multiview Texture and Depth Information for Graphics Applications (그래픽스 응용을 위한 다시점 텍스처 및 깊이 정보의 근접 무손실 부호화)

  • Yoon, Seung-Uk;Ho, Yo-Sung
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.46 no.1
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    • pp.41-48
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    • 2009
  • This Paper introduces representation and coding schemes of multiview texture and depth data for complex three-dimensional scenes. We represent input color and depth images using compressed texture and depth map pairs. The proposed X-codec encodes them further to increase compression ratio in a near-lossless way. Our system resolves two problems. First, rendering time and output visual quality depend on input image resolutions rather than scene complexity since a depth image-based rendering techniques is used. Second, the random access problem of conventional image-based rendering could be effectively solved using our image block-based compression schemes. From experimental results, the proposed approach is useful to graphics applications because it provides multiview rendering, selective decoding, and scene manipulation functionalities.

A Study on the Relationship between College Women's Preference in Clothing Design and Interest (여대생의 의복디자인 기호와 흥미간의 상관연구)

  • 이인자
    • Journal of the Korean Home Economics Association
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    • v.12 no.34
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    • pp.663-677
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    • 1974
  • The social and psychological approaches to clothing researches by Fluge,l, Hurlock and Barr in the early 1930's have since been developed greatly. It has now been generally agreed that clothing is the symbol of one's personality and social status, for clothing is regarded as the second skin and a manifestation of one's emotional states as well. Based on this consensus, this study was intended to observe the possible relationship between one's clothing design preference-in line, color and texture- and interest. For this survey, 200 college woman students from four universities were selected at random, and an interest-test standardized by prof. Jung Bum Mo and a questionaire made of 20 items on the clothing prferences were given. The results as commputerized and analyzed are as follows : 1. Line Preference a) Structural line : It is quite obvious that those like straight line are interested in fine arts, and curved line in physics. b) Out-line : Among tubular, bell and bustle of the silhouette, those like the bustle have shown particular interest in music, and the tubular in politics and business. c) Style : There is a salient tendency that those like a dressy style are much interested in music, and casual style in physics and physical exercise. 2. Color Preference a) Favorite color : Those like red, orange and yellow show a high interest in artistic activities and physical exercise, and black, grey and white in politics. b) Variety and combination of color ; These have shown no relationship to the interest. 3. Texture Preference a) The touch : Those like the texture with the feeling the crisp and rough are interested in fine arts, and of soft and smooth in the field of social service. b) Fabric surface : Those like naturalistic pattern, i.e. print of flowers, show much interest in music and literature, and plain fabrics in physical exercise.

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Object Tracking Using Particle Filters in Moving Camera (움직임 카메라 환경에서 파티클 필터를 이용한 객체 추적)

  • Ko, Byoung-Chul;Nam, Jae-Yeal;Kwak, Joon-Young
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.5A
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    • pp.375-387
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    • 2012
  • This paper proposes a new real-time object tracking algorithm using particle filters with color and texture features in moving CCD camera images. If the user selects an initial object, this region is declared as a target particle and an initial state is modeled. Then, N particles are generated based on random distribution and CS-LBP (Centre Symmetric Local Binary Patterns) for texture model and weighted color distribution is modeled from each particle. For observation likelihoods estimation, Bhattacharyya distance between particles and their feature models are calculated and this observation likelihoods are used for weights of individual particles. After weights estimation, a new particle which has the maximum weight is selected and new particles are re-sampled using the maximum particle. For performance comparison, we tested a few combinations of features and particle filters. The proposed algorithm showed best object tracking performance when we used color and texture model simultaneously for likelihood estimation.