Now showing items 1-20 of 28

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    Co-existance between AC-distribution and DC-distribution: in the view of appliances 

    Kittiphan Techakittiroj; Virach Wongpaibool (2009)

    This work demonstrates the possibility of using the available-in-market appliances in a DC-distribution system. This demonstration also represents an alternative migration from AC-distribution to DC-distribution. DC-distribution has been shown to be more efficient and provided good power quality in a distribution system. The power supply technology in the modern appliances makes the possibility of an appliance to be used in either both AC-distribution and DC-distribution without any modification. Appliances are tested by using an AC-source ...
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    Video enhancement using a robust iterative SRR based on leclerc stochastic estimation 

    Vorapoj Patanavijit (2009-09)

    Recent results in SRR (Super Resolution Reconstruction) demonstrate that the fusion of a sequence of low-resolution noisy blurred images can produce a higher-resolution image or sequence. Since noise is always present in practical acquisition systems, almost video enhancement algorithms are developed assuming AWGN model for the corruption noise. When the underlying video measurements are corrupted by other noise models such as Poisson Noise, impulsive Noise (Salt & Pepper) and Speckle Noise, the enhancement algorithms fail to recover a close ...
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    Pattern matching by optimizing load in a reflectarray antenna 

    Bhattarai, Amulya; Wallace, Jon (2009-10)

    A novel method to match radiation pattern of a reflectarray antenna by optimizing the load is presented in this paper. By varying the load attached to each element in a reflectarray the reflection coefficient at each element is varied, which varies the overall radiation pattern of the reflectarray antenna. This paper addresses the synthesis problem, "What is the optimal loading configuration given a target radiation pattern?" Mathematical solution for computing the optimal load for a target radiation pattern is presented. ADS and MATLAB ...
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    Multiframe resolution-enhancement using a robust iterative SRR based on leclerc stochastic technique 

    Vorapoj Patanavijit (2009-10)

    This paper proposes a multiframe resolution-enhancement using a robust iterative SRR (Super-Resolution Reconstruction) for applying on images that is corrupted by several nose models. Typically, the success of SRR algorithms is highly dependent on the model accuracy regarding the imaging process. The real noise models corrupting the measure sequence are unknown hence SRR algorithms using L1 or L2 norm may degrade the image sequence rather than enhance it. The proposed enhancement algorithm is based on the stochastic regularization SRR technique ...
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    Video enhancement using a robust iterative SRR based on andrew's sine regularization technique 

    Vorapoj Patanavijit (2009-12)

    In this paper, we propose a alternative robust video enhancement algorithm using SRR based on the regularization ML technique. First, the classical registration process is used to estimate the relationship between the reference frame and other neighboring frames. Subsequently, the Andrew's Sine norm is used for measuring the difference between the projected estimate of the high quality image and each low high quality image and for removing outliers in the data. Moreover, Tikhonov regularization is incorporated in the proposed framework in order ...
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    A fast image recovery using compressive sensing technique with block based orthogonal matching pursuit 

    Vorapoj Patanavijit; Parichat Sermwuthisarn; Supatana Auethavekiat (2009-12)

    Traditionally, the problems of applying Orthogonal Matching Pursuit (OMP) to large images are its high computing time and its requirement for a large matrix. In this paper, we propose a fast image recovery algorithm by dividing the image into block of nxn pixels and applying OMP to each nxn block instead of the entire image. The key idea is that small matrix requires less computing time and less memory. In the experiment, the block based OMP was applied to three standard test images: Lena, Mandrill and Pirate. Compared to standard OMP, block ...
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    Video enhancement using a robust iterative SRR based on a German&McClure stochastic estimation with a general observation model 

    Vorapoj Patanavijit (2010-05)

    This paper proposes the novel robust SRR algorithm that can be effectively applied on the sequence that are corrupted by various noise models and can be applied on the real or standard sequence. First, the proposed SRR algorithm is based on the German&McClure norm that used for measuring the difference between the projected estimate of the high quality image and each low high quality image and for removing outliers in the data. Second, in order to cope with real video sequences and complex motion sequences, the proposed SRR is based on a general ...
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    Performance evaluation of L1, L2 and SL0 on compressive sensing based on stochastic estimation technique 

    Ha, Pham Hong; Vorapoj Patanavijit (2010-05)

    In this paper, we proposed 2 algorithms based on L1 and L2 norm estimator to recover the signal by using just few components. Moreover we comprehensively present the recovery algorithm based on L1, L2 and SL0 for digital signal or image under some several noise models from their incomplete observation. The proposed algorithm is used with a matrix that the number of row is much fewer than the column. The algorithm states that if signal or image is sufficient sparse, we can recover it from small number of linear measurement by solving convex ...
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    Robust compressed sensing in Gaussian noise environment by resampling with replacement 

    Vorapoj Patanavijit; Duangrat Gansawaf; Parichat Sermwuthisarn; Supatana Auethavekiat (2012)

    A reconstruction method using the ensemble of compressed measurement signals is proposed for reconstructing the image from the signal corrupted by Gaussian noise. The ensemble is created from one signal under the assumption that an image is highly redundant; hence, it is approximated as the mixture of a number of signals. The proposed method adopted the sampling with replacement in bootstrapping to extract L signals from the mixture. The extracted L signals from the ensemble of signals corrupted by Gaussian noise with the same mean and variance. ...
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    An Experimental Performance Analysis of Image Reconstruction Techniques under Both Gaussian and Non-Gaussian Noise Models 

    Vorapoj Patanavijit (2012-07)

    Recently, the images reconstruction approaches are very essential in digital image processing (DIP), especially in terms of removing the noise contaminations and recovering the content of images. Each image reconstruction approach has different mathematical models. Therefore a performance of individual reconstruction approach is varied depending on several factors such as image characteristic, reconstruction mathematical model, noise model and noise intensity. Thus, this paper presents comprehensive experiments based on the comparisons ...
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    Experimental Study Efficiency of Robust Models of Lucas-Kanade Optical Flow Algorithms in the Present of Non-Gaussian Noise 

    Vorapoj Patanavijit (2012-07)

    This paper presents experimental efficiency study of noise tolerance model of spatial optical flow based on LucasKanade (LK) algorithms such as original LK with kernel of Barron, Fleet, and Beauchemin (BFB), confidence based optical flow algorithm for high reliability (CRR), robust motion estimation methods using gradient orientation information (RGOI), and a novel robust and high reliability for LucasKanade optical flow algorithm using median filter and confidence based technique (NRLK) under several NonGaussian Noise. These experiment ...
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    Single Loop and Double Loop Control of AU Self-Balancing Bicycle (AUSB) 

    Narong Aphiratsakun; Kittiphan Techakittiroj (2012-12)

    This paper evaluates the controllers performance on AU Self-balancing Bicycle (AUSB). The gyroscope is used to sense the balanced position of the bicycle while an encoder is used to sense the position of the flywheel. The Single loop uses a gyroscope sensor and an additional encoder sensor is used in the Double loop. The main objective of this paper is to demonstrate the improvement in the performance of the AUSB. In the Single loop control, the bicycle can balance within a certain flywheel angle, and then the bicycle will fall. In the Double ...
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    Fast Image Restoration Technique for Car License Plate Based on PWS filter Using 2DPCA Algorithm 

    Vorapoj Patanavijit (2013)

    In this paper, we propose the algorithm that used to identify car license plate that the capture images come in degraded version by combining a PWS filtering technique with a 2DPCA algorithm. From experiment results, our algorithm has three advantages. First, it can be operated to the image directly without transforming the structure of the image, which is two dimensional data, into a vector. Second, it can be implemented with less burden of computation and requires less memory. At last, less time is required to restore the image.
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    Capacity and Fairness Analysis of Game Theoretic Power Controlled Wireless Access Network 

    Katan Vattanaviboon; Patrachart Komolkiti; Chaodit Aswakul (2013)

    In wireless networks, transmission power has adverse effects. With low transmission power, the received signal may be eclipsed by the noise and interference from other transmitters, resulting in low SINR. On the other hand, with high transmission power, the interference seen at other receivers could be too large, also resulting in low SINR. This paper aims to address this problem by using the game theory. Particularly, the scenario of wireless access network with two transmitters, each with two intended receivers, is considered. Selection of ...
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    A Novel Frequency Domain Image Reconstruction Based on the Tikhonov Regularization and Robust Estimation Technique for Compressive Sensing 

    Vorapoj Patanavijit (2013-05)

    Recently, a lot of attention has been paid to image reconstructionalgorithms based on Smoothed L0 (SL0) under the frequency domain. SL0 is fast and accurate under the noise free environment however it is unstable with the additional noise.According to ill-posed condition; without any prior information of the original image, the reconstruction procedure of SL0 is much affected by the noise. The frequency domain Tikhonov reduces and constrains the gap of restored image due to the ill-posed situation. Therefore, image restoration algorithm is ...
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    Experimental Efficiency Analysis in Robust models of Spatial Correlation Optical Flow Methods under Non Gaussian Noisy Contamination 

    Darun Kesrarat; Vorapoj Patanavijit (2013-05)

    In this paper, we present a performance analysis of several robust models of spatial correlation optical flow algorithms including an original spatial correlation optical flow (SCOF), bidirectional for high reliability optical flow (BHR), gradient orientation information for robust motion estimation (GOI), and robust and high reliability based on bidirectional symmetry and median motion estimation (RHR) under the non Gaussian noise conditions. The simulated results are tested on 4 different in foreground and background movement characteristics ...
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    Improved Bandwidth Allocation In Cognitive Radio Networks Based on Game Theory 

    Bhattarai, Amulya; Patrachart Komolkiti; Chaodit Aswakul (2013-05)

    In this paper, an improved method for bandwidth allocation in a Cognitive Radio Network based on game theory is presented. In this work, utility has been modified by inserting weights to the three terms, received power, interference to other links and interference from other links. Inserting weights enables us to treat different CRN scenarios separately and appropriately as per the requirement of the administrator. Moreover, a suitable performance index for a CRN that considers throughput and interference to other links has been introduced ...
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    Performance and Comparative Exploration of Reconstructed Quality for An Iterative SRR Algorithm Based on Robust Norm Functions Under Several Noise Surrounding 

    Vorapoj Patanavijit (2014)

    The multi-frame SRR (Super Resolution Reconstruction) algorithm has become the significant theme in digital image research society in the last ten years because of its performance and its cost effectiveness hence many robust norm functions (both redescending and non-redescending influence functions) have been usually incorporated in the multi-frame SRR framework, which is combined a stochastic Bayesian approach and a regularization technique into the unify SRR framework. Consequently, this paper thoroughly presents experimental exploration ...