• Title/Summary/Keyword: random field

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Contextual Modeling and Generation of Texture Observed in Single and Multi-channel Images

  • Jung, Myung-Hee
    • Korean Journal of Remote Sensing
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    • v.17 no.4
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    • pp.335-344
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    • 2001
  • Texture is extensively studied in a variety of image processing applications such as image segmentation and classification because it is an important property to perceive regions and surfaces. This paper focused on the analysis and synthesis of textured single and multiband images using Markov Random Field model considering the existent spatial correlation. Especially, for multiband images, the cross-channel correlation existing between bands as well as the spatial correlation within band should be considered in the model. Although a local interaction is assumed between the specified neighboring pixels in MRF models, during the maximization process, short-term correlations among neighboring pixels develop into long-term correlations. This result in exhibiting phase transition. In this research, the role of temperature to obtain the most probable state during the sampling procedure in discrete Markov Random Fields and the stopping rule were also studied.

Comparison of Simple Random Sampling and Two-stage P.P.S. Sampling Methods for Timber Volume Estimation (임목재적(林木材積) 산정(算定)을 위(爲)한 Simple Random Sampling과 Two-stage P.P.S. Sampling 방법(方法)의 비교(比較))

  • Kim, Je Su;Horning, Ned
    • Journal of Korean Society of Forest Science
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    • v.65 no.1
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    • pp.68-73
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    • 1984
  • The purpose of this paper was to figure out the efficiencies of two sampling techniques, a simple random sampling and a two-stage P.P.S. (probability proportional to size) sampling, in estimating the volume of the mature coniferous stands near Salzburg, Austria. With black-and-white infrared photographs at a scale 1:10,000, the following four classes were considered; non-forest, young stands less than 40 years, mature beech and mature coniferous stands. After the classification, a field survey was carried out using a relascope with a BAF (basal area factor) 4. For the simple random sampling, 99 points were sampled, while for the P.P.S. sampling, 75 points were sampled in the mature coniferous stands. The following results were obtained. 1) The mean standing coniferous volume estimate was $422.0m^3/ha$ for the simple random sampling and $433.5m^3/ha$ for the P.P.S. sampling method. However, the difference was not statistically significant. 2) The required number of sampling points for a 5% sampling error were 170 for the two stage P.P.S. sampling, but 237 for the simple random sampling. 3) The two stage P.P.S. method reduced field survey time by 17% as compared to the simple random sampling.

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The invariance principle for $\rho$-mixing random fields

  • Kim, Tae-Sung;Seok, Eun-Yang
    • Journal of the Korean Mathematical Society
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    • v.32 no.2
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    • pp.321-328
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    • 1995
  • Ibragimov(1975) showed the central limit theorem and the invariance principle for $\rho$-mixing random variables satisfying $\sigma^2(n) = nh(n) \longrightarrow \infty$ and $E$\mid$\zeta_0$\mid$^{2+\delta} < \infty$ for some $\delta > 0$ where $\sigma^2(n)$ denotes the variance of the partial sum $S_n$ and h(n) is a slowly varying function.

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Structural Aspects in the Theory of Random Walk

  • Heyer, H.
    • Journal of the Korean Statistical Society
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    • v.11 no.2
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    • pp.118-130
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    • 1982
  • Random walks as specia Markov stochastic processes have received particular attention in recent years. Not only the applicability of the theory already developed but also its extension within the frame work of probability measures on algebraic-topological structures such as semigroups, groups and linear spaces became a new challenge for research work in the field. At the same time new insights into classical problems were obtained which in various cases lead to a more efficient presentation of the subject. Consequently the teaching of random walks at all levels should profit from the recent development.

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The invariance principle for associated random fields

  • Kim, Tae-Sung;Seok, Eun-Yang
    • Journal of the Korean Mathematical Society
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    • v.31 no.4
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    • pp.679-689
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    • 1994
  • Let ${X_\underline{j} : \underline{j} \in Z^d}$ be a random field on some probability space $(\Omega, F, P)$ with $EX_\underline{j} = 0, EX_\underline{j}^2 < \infty$.

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Impact of Trap Position on Random Telegraph Noise in a 70-Å Nanowire Field-Effect Transistor

  • Lee, Hyunseul;Cho, Karam;Shin, Changhwan;Shin, Hyungcheol
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.2
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    • pp.185-190
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    • 2016
  • A 70-${\AA}$ nanowire field-effect transistor (FET) for sub-10-nm CMOS technology is designed and simulated in order to investigate the impact of an oxide trap on random telegraph noise (RTN) in the device. It is observed that the drain current fluctuation (${\Delta}I_D/I_D$) increases up to a maximum of 78 % due to the single electron trapping. In addition, the effect of various trap positions on the RTN in the nanowire FET is thoroughly analyzed at various drain and gate voltages. As the drain voltage increases, the peak point for the ${\Delta}I_D/I_D$ shifts toward the source side. The distortion in the electron carrier density and the conduction band energy when the trap is filled with an electron at various positions in the device supports these results.

Image Dehazing using Transmission Map Based on Hidden Markov Random Field Model (은닉 마코프 랜덤 모델 기반의 전달 맵을 이용한 안개 제거)

  • Lee, Min-Hyuk;Kwon, Oh-Seol
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.1
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    • pp.145-151
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    • 2014
  • This paper proposes an image haze removal algorithm for a single image. The conventional Dark Channel Prior(DCP) algorithm estimates a transmission map using the dark information in an image, and the haze regions are then detected using a matting algorithm. However, since the DCP algorithm uses block-based processing, block artifacts are invariably formed in the transmission map. To solve this problem, the proposed algorithm generates a modified transmission map using a Hidden Markov Random Field(HMRF) and Expectation-Maximization(EM) algorithm. Experimental results confirm that the proposed algorithm is superior to conventional algorithms in image haze removal.

Exact Decoding Probability of Random Linear Network Coding for Tree Networks

  • Li, Fang;Xie, Min
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.2
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    • pp.714-727
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    • 2015
  • The hierarchical structure in networks is widely applied in many practical scenarios especially in some emergency cases. In this paper, we focus on a tree network with and without packet loss where one source sends data to n destinations, through m relay nodes employing random linear network coding (RLNC) over a Galois field in parallel transmission systems. We derive closed-form probability expressions of successful decoding at a destination node and at all destination nodes in this multicast scenario. For the convenience of computing, we also propose an upper bound for the failure probability. We then investigate the impact of the major parameters, i.e., the size of finite fields, the number of internal nodes, the number of sink nodes and the channel failure probability, on the decoding performance with simulation results. In addition, numerical results show that, under a fixed exact decoding probability, the required field size can be minimized. When failure decoding probabilities are given, the operation is simple and its complexity is low in a small finite field.