Recent Submissions

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    Damped Oscillator under Stokesian Realm and Added-Mass Effects 

    Jiradech Kongthon (2015)

    This article presents the modeling and simulations of a sphere that oscillates vertically in a high-viscosity liquid. The sphere is connected to a linear spring and given an initial displacement from the equilibrium position to allow free vibration and the sphere undergoes the inertia force, the spring force, the drag force, the buoyancy force, the gravity force, and the added-mass force. In general, the added-mass force is not considered in modeling an oscillator. In this article, the added-mass force is included in the modeling to ref...
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    Tracking of High-speed, Non-smooth and Microscale-amplitude Wave Trajectories 

    Jiradech Kongthon (2016)

    In this article, an inversion-based control approach is proposed and presented for tracking desired trajectories with high-speed (100Hz), non-smooth (triangle and sawtooth waves), and microscale-amplitude (10 micron) wave forms. The interesting challenge is that the tracking involves the trajectories that possess a high frequency, a microscale amplitude, sharp turnarounds at the corners. Two different types of wave trajectories, which are triangle and sawtooth waves, are investigated. The model, or the transfer function of a piezoactuator ...
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    Conceptual Framework of Super Resolution Reconstruction Based on Frequency Domain From Aliased Multi-Low Resolution Images: Theory Part 

    Vorapoj Patanavijit (2016)

    Typically, a spatial resolution (Pixel per Area) is an important factor used to define the image quality. Due to the dramatically advance of digital image processing in this decade, high resolution (HR) images are in demand because HR images give more detail and information that directly impact their application performance. Today, there are several techniques that can capture high resolution images such as resolution increment by reducing pixel side. Consequently this high resolution sensor is so expensive and do not proper for general applica...
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    A Conceptual Framework of Super Resolution Reconstruction (SRR) Techniques 

    Vorapoj Patanavijit (2016)

    Typically, a spatial resolution (Pixel per Area) is an important factor used to define the image quality. Due to the dramatically advance of digital image processing in this decade, high resolution (HR) images are in demand because HR images give more detail and information that directly impact their application performance. Today, there are several techniques that can capture high resolution images such as resolution increment by reducing pixel side. Consequently this high resolution sensor is so expensive and do not proper for general ap...
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    A Modified- Fast Spectrum Sensing with Coordinate System under Path Loss Effect and Noise Uncertainty for Cognitive Radio Networks 

    Vorapoj Patanavijit (2015)

    Spectrum sensing is a critical function for cognitive radio which is used to continually monitor the activities of PU in the licensed spectrum band. In this paper, we first re-derive some parameters of FSC algorithm, which is called Modified- fast spectrum sensing with coordinate system (MFSC), to perform spectrum sensing under path loss effect and noise uncertainty. Then, performance of three knowledgebased spectrum sensing techniques — MFD, LED and MFSC — are evaluated under path loss effect and noise uncertainty. From the simulation res...
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    A performance impact of Andrew’s Sine threshold for a robust regularized SRR based on ML framework 

    Vorapoj Patanavijit (2016)

    One of the most successful Digital Image Reconstruction (DIR) techniques for increasing image resolution and improving image quality is the Super-Resolution Reconstruction (SRR), which is the procedure of integrating a collection of aliased low-resolution low-quality images to form a single high-resolution high-quality image. However, the mainstream SRR algorithms are too delicate to noisy environments because these mainstream SRR algorithms are often comprised by the ML (L1 or L2) estimation techniques thereby the new robust SRR algorithm, whi...
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    Comparative Experimental Exploration of Robust Norm Functions for Iterative Super Resolution Reconstructions under Noise Surrounding 

    Vorapoj Patanavijit (2015)

    In DIP (Digital Image Processing) research society, the multi-frame SRR (Super Resolution Reconstruction) algorithm has grown to be the momentous theme in the last ten years because of its cost e ectiveness and its superior spectacle. Consequently, for a multi-frame SRR algorithm which is commonly comprised of a Bayesian ML (Maximum Likelihood) approach and a regularization technique into the unify SRR framework, numerous robust norm functions (which have both redescending and non-redescending in uence functions) have been commonly c...
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    An Adaptive And Statistical Efficiency Myriad Filter For A Recursive Image Reconstruction Using a Multi-Frame SRR Algorithm With A Stochastic Regularization For Video Sequences 

    Vorapoj Patanavijit (2015)

    In real applied implementations, a collection of classical linear filtering theories, for example, a Median filter and a Mean filter, can be only applied to the Gaussian noise environments due to the fact that these linear filters usually gives the poor performance under the presence of non-Gaussian noise environments. Because of the motion estimation blunder and observation process error, which are usually caused from real electronic noise, non-accurate optical devices or mathematical simplification models of observed process systems, the...
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    Studies on Inter-component Communication Latency based on Variation Number of Components and Packet size in SDR-SCA Waveform Application 

    Pasd Putthapipat; Andrian, Jean H.; Liu, Chen (2016)

    The ability to use software defined radio (SDR) in the civilian mobile applications will open up the next generation of mobile devices to reality such as multi-standard personal wireless devices or ubiquitous wireless devices. Many challenges in commercialising SDR are still the subject of interest in the software radio research community. Four main issues that have been already addressed are performance, size, weight, and power. The investigation presents in-depth study of SDR inter-components communications in terms of total link delay relate...
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    Policies for Channel Allocation in Cognitive Radio Networks using Game Theory 

    Bhattarai, Amulya (2016)

    Cognitive radio networks evolve according to the actions of sel sh users who act independently. The eventual state reached in most of the cases by such a system is a Nash Equilibrium (NE). Multiple NE with di erent qualities may exist. In this work we consider the problem of allocating channels to multiple transceivers. Based on policies derived from various network metrics we develop a way to initialize the allocation and choose the appropriate channel for each user to push the system towards a higher normalized cumulative total thro...
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    Computational Tutorial of Steepest Descent Method and Its Implementation in Digital Image Processing 

    Vorapoj Patanavijit (2013)

    In the last decade, optimization techniques have extensively come up as one of principal signal processing techniques, which are used for solving many previous intractable problems in both digital signal processing (DSP) problems and digital image processing (DIP) problem. Due to its low computational complexity and uncomplicated implementation, the Gradient Descent (GD) method [1] is one of the most popular optimization methods for problems, which can be formulated as a differentiable multivariable functions. The GD method is ubiquitousl...

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