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2018

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Probabilistic Dynamic Security Assessment Of Large Power Systems Using Machine Learning Algorithms, Sevda Jafarzadeh, Veysel Murat İstemi̇han Genç Jan 2018

Probabilistic Dynamic Security Assessment Of Large Power Systems Using Machine Learning Algorithms, Sevda Jafarzadeh, Veysel Murat İstemi̇han Genç

Turkish Journal of Electrical Engineering and Computer Sciences

Arrhythmia, also known as dysrhythmia, is a condition involving an irregular heartbeat. A problem in the heart may cause problems in other organs, and as time passes, this will lead to more severe problems. Arrhythmia must be detected at an early stage to prevent such a problem occurring in the heart. Detection of arrhythmia from an electrocardiogram is an easy method that does not need much equipment and does not harm the patient. The purpose of this research is to find a faster and more accurate system to classify nine classes of arrhythmia. The St. Petersburg Institute of Cardiological Technics …

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The Application Of Analytical Mechanics In A Multimachine Power System, Zhijie Wang, Zhiyuan Liu, Jie Wang, Xiuchen Jiang, Sanming Liu, Yifang Liu, Gehao Sheng, Tianyu Liu Jan 2018

The Application Of Analytical Mechanics In A Multimachine Power System, Zhijie Wang, Zhiyuan Liu, Jie Wang, Xiuchen Jiang, Sanming Liu, Yifang Liu, Gehao Sheng, Tianyu Liu

Turkish Journal of Electrical Engineering and Computer Sciences

Analytical mechanics methods play an important role in determining the energy function and Hamilton realization of a system. In this paper, the Hamilton function of the system is obtained directly from the system differential equation by means of analytical mechanics. In addition, the system Hamiltonization process requires that the system must be even order, and the commonly used generator model is a single-axis third-order model. For this reason, the odd-order power system model is extended to an even-order system. The Hamilton function of the system is deduced with coordinate transformation and the generalized force. Then the standard form of Hamilton …

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Conception And Control Of A Wtgs System Using A Novel Control Technique Based On Mpc-Dpc-Mvf With A Switch Optimization Process, Mansour Madaci, Djallel Kerdoun Jan 2018

Conception And Control Of A Wtgs System Using A Novel Control Technique Based On Mpc-Dpc-Mvf With A Switch Optimization Process, Mansour Madaci, Djallel Kerdoun

Turkish Journal of Electrical Engineering and Computer Sciences

The work proposed through this paper presents a novel technique applied for the control of a wind turbine generation system (WTGS) prototype. A model predictive control combined with a direct power control technique (MPC-DPC) based on SVM control and a novel switching cycle sequence pattern for thermal switch losses reduction have been adopted. The novel developed direct power control (DPC) scheme based on a multivariable filter (MVF) topology for power estimation process has been illustrated. The control of the converter system is adopted through a predictive control strategy to achieve a complete and an instantaneous control over the active and …

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High-Power Density Switched Reluctance Machine Development For High-Speed Spindle Applications, Yusuf Yasa, Yilmaz Sözer, Muhammet Gari̇p Jan 2018

High-Power Density Switched Reluctance Machine Development For High-Speed Spindle Applications, Yusuf Yasa, Yilmaz Sözer, Muhammet Gari̇p

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a high-speed switched reluctance machine (HS-SRM) with cobalt-iron lamination material is proposed for spindle motors, which are used in computer numerical control machines. Wide torque-speed range, high power density, high efficiency, and low cost are the crucial issues in spindle applications. Three types of electric machine candidates, the permanent magnet synchronous machine (PMSM), induction machine (IM), and switched reluctance machine (SRM), are compared with their outstanding features. The SRM spindle motor will offer a more robust, reliable, compact, and cost-effective solution compared to the IM or PMSM spindle applications. Moreover, advancement on cobalt-iron laminations gives a chance …

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Adaptive Collaborative Speed Control Of Pmdc Motor Using Hyperbolic Secant Functions And Particle Swarm Optimization, Omer Saleem, Khalid Mahmood-Ul-Hasan Jan 2018

Adaptive Collaborative Speed Control Of Pmdc Motor Using Hyperbolic Secant Functions And Particle Swarm Optimization, Omer Saleem, Khalid Mahmood-Ul-Hasan

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents an adaptive collaborative speed controller for a permanent magnet direct-current (PMDC) motor. The proposed scheme beneficially combines the control efforts of a proportional-integral (PI) controller and a linear-quadratic regulator (LQR) via a weighted summing module. Initially, the weightages of the summing module are kept fixed. They are optimally tuned and tested via the particle swarm optimization algorithm. In order to synergize the controller combination, these weightages are adaptively modulated as well, using hyperbolic secant functions of the error dynamics of the motor's angular speed. The adaptive combination renders significant enhancement in the transient response, steady-state response, input-energy …

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Simulation Of Infinite Periodic Graphene Planar Grating In The Thz Range By The Method Of Singular Integral Equations, Mstislav Kaliberda, Leonid Lytvynenko, Sergey Pogarsky Jan 2018

Simulation Of Infinite Periodic Graphene Planar Grating In The Thz Range By The Method Of Singular Integral Equations, Mstislav Kaliberda, Leonid Lytvynenko, Sergey Pogarsky

Turkish Journal of Electrical Engineering and Computer Sciences

Plane wave diffraction by the infinite periodic planar graphene grating and infinite grating above a perfectly conducting plane in the THz range is considered. The mathematical model is based on the graphene surface impedance and the method of singular integral equations. A comparison with finite grating is made. Reflectance, transmittance, and absorbance are studied as a function of graphene and grating parameters.

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Performance Analysis Of Distributed Fiber Raman Amplifiers Employing Higher Order Pumping Schemes In Optical Transmission Systems, Kulwinder Singh Malhi, Manjeet Singh Patterh, Manjit Singh Bhamrah Jan 2018

Performance Analysis Of Distributed Fiber Raman Amplifiers Employing Higher Order Pumping Schemes In Optical Transmission Systems, Kulwinder Singh Malhi, Manjeet Singh Patterh, Manjit Singh Bhamrah

Turkish Journal of Electrical Engineering and Computer Sciences

Performance of fiber Raman amplifier is explored with special emphasis on higher order pumping configurations for wavelength division multiplexed optical transmission systems. The amplification analysis is done in terms of equivalent noise figure (ENF), optical signal-to-noise ratio (OSNR), and double Rayleigh backscattering (DRBS) noise powers. The investigations reveal that at 36 dB on--off gain, ENF improvement of 1 dB (using second order pumping) and of 2 dB (using third order pumping configuration) can be achieved. On similar lines, by varying input optical power and fiber length, OSNR and DRBS are reported for the higher order of pumping configurations. Overall, the …

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On The Power Handling Of A High Power Combiner For Industrial, Scientific, And Medical Applications, Arash Ahmadi Jan 2018

On The Power Handling Of A High Power Combiner For Industrial, Scientific, And Medical Applications, Arash Ahmadi

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper a 2-way broadband power combiner that can handle up to 1 kW output power is designed and fabricated. The combiner covers the frequency range of 30 to 500 MHz, which is intended for industrial, scientific, and medical (ISM) applications. The power handling of the power combiner depends on the power handling of the components that constitute the combiner. The combiner is composed of some coaxial transmission lines and a transmission line transformer. The ferrite cores, which are used to suppress the common mode current, are one of the major limiting factors, regarding the power handling of the …

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Sf6 Gas-Insulated 50-Kva Distribution Transformer Design, Okan Özgönenel, David Thomas, Ünal Kurt Jan 2018

Sf6 Gas-Insulated 50-Kva Distribution Transformer Design, Okan Özgönenel, David Thomas, Ünal Kurt

Turkish Journal of Electrical Engineering and Computer Sciences

There are increasing environmental concerns such that governments are pressured to cooperate with international concurrences. One of the most harmful contaminants is mineral oil when it infiltrates the soil. Although it is a good material in the act of insulating in distribution/power transformers, it presents some environmental hazards and safety disadvantages. For this reason, gas-insulated transformers are considered particularly for hazardous locations. An oil-insulated distribution transformer of 50 kVA, 34.5/0.4 kV, and 50 Hz is investigated and converted to SF6 gas-insulated transformer in this study. The suggested distribution transformer model with SF6 insulated has many benefits, such as being explosion-proof …

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A Low-Complexity Rare-Based 2-D Doa Estimation Algorithm For A Mixture Of Circular And Strictly Noncircular Sources, Kashif Shabir, Tarek Hasan Al Mahmud, Rui Zheng, Zhongfu Ye Jan 2018

A Low-Complexity Rare-Based 2-D Doa Estimation Algorithm For A Mixture Of Circular And Strictly Noncircular Sources, Kashif Shabir, Tarek Hasan Al Mahmud, Rui Zheng, Zhongfu Ye

Turkish Journal of Electrical Engineering and Computer Sciences

A new rank reduction (RARE)-based two-dimensional (2-D) direction of arrival (DOA) estimation algorithm is proposed considering a mixture of circular and strictly noncircular sources. To enhance array aperture, a geometry of three uniform linear arrays is considered and then treated as displaced arrays from a virtual array using a simple linear transformation. The received data and the conjugated counterpart are combined together, exploiting the noncircular property. Both sources can be estimated separately by designing and exploiting the distinctive nature of circular and noncircular steering vectors. However, a 2-D spectrum search would lead to a high computational complexity burden. To reduce …

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Long-Term Multiobject Tracking Using Alternative Correlation Filters, Kemal Batuhan Başkurt, Refi̇k Samet Jan 2018

Long-Term Multiobject Tracking Using Alternative Correlation Filters, Kemal Batuhan Başkurt, Refi̇k Samet

Turkish Journal of Electrical Engineering and Computer Sciences

We propose a real-time multiobject-tracking approach that is minimally affected by environmental conditions and target appearance change. The aim of the proposed approach is to track any object in a scene, regardless of object type, since tracking all of the objects in a scene is critical and widely used in surveillance applications. Thus, motion detection results are used to initialize the trackers. The proposed object-tracking approach is realized with two types of independent correlation filters estimating location and scale. Alternative correlation filters representing different appearances of the target are also proposed in order to increase the robustness of the approach …

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Image Reconstruction For Frequency-Domain Diffuse Optical Tomography, Vicky Mudeng, Yun Priyanto, Andhika Giyantara Jan 2018

Image Reconstruction For Frequency-Domain Diffuse Optical Tomography, Vicky Mudeng, Yun Priyanto, Andhika Giyantara

Turkish Journal of Electrical Engineering and Computer Sciences

The image reconstruction algorithm of diffuse optical tomography (DOT) is based on the diffusion equation and involves both the forward problem and inverse solution. The forward problem solves the diffusion equation using the finite element method for calculating the transmitted light distribution under the condition of presumed light source and optical coefficient. The inverse solution reconstructs the optical property coefficient distribution using Newton's method. The work within this study develops an image reconstruction algorithm for frequency-domain DOT. A numerical simulations approach to light propagation in the tissue is conducted, while the optical property is reconstructed employing data around the boundary. …

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An Efficient Structure For T-Cntfets With Intrinsic-N-Doped Impurity Distribution Pattern In Drain Region, Ali Naderi, Maryam Ghodrati Jan 2018

An Efficient Structure For T-Cntfets With Intrinsic-N-Doped Impurity Distribution Pattern In Drain Region, Ali Naderi, Maryam Ghodrati

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, by using impurity distribution engineering of drain region, an efficient structure is proposed for tunneling carbon nanotube field-effect transistors (T-CNTFETs). The drain region of the proposed structure consists of two parts. The impurity density of the part close to the channel is intrinsic and the other is n-type with constant density of 1 nm$^{-1}$. In conventional T-CNTFETs, heavily doped drain causes a spiky drop of potential energy around the channel to drain junction resulting in a pathway for carriers in the valence band to tunnel to the conduction band which means ambipolar behavior and large leakage current. …

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Improved Transient Response Capacitor Less Low Dropout Regulator Employing Adaptive Bias And Bulk Modulation, Suresh Alapati, Sreehari Rao Patri Jan 2018

Improved Transient Response Capacitor Less Low Dropout Regulator Employing Adaptive Bias And Bulk Modulation, Suresh Alapati, Sreehari Rao Patri

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a low quiescent current, fast settling time, and adaptively biased capacitor less low-dropout (LDO) regulator. The topology involves a segmented pass transistor with bulk modulation and adaptively biased current control stages to improve the transient performance. The bulk modulation of the pass transistor assists in fast settling of the output voltage. The frequency compensation makes the LDO voltage regulator stable adaptively over load current transitions. In addition, the biasing stage is designed such that it adapts to the load transitions while consuming the quiescent current abstemiously. This arrangement further improves settling time to be within 1 µs …

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Design Of An On-Chip Hilbert Fractal Inductor Using An Improved Feed Forward Neural Network For Si Rfics, Akhendra Kumar Padavala, Bheema Rao Nistala Jan 2018

Design Of An On-Chip Hilbert Fractal Inductor Using An Improved Feed Forward Neural Network For Si Rfics, Akhendra Kumar Padavala, Bheema Rao Nistala

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents an efficient modeling of Hilbert fractal inductors by improved feed forward neural network trained hybrid particle swarm optimization and gravitational search algorithm (FNNPSOGSA). The proposed model computes the effective inductance value (L) and quality factor (Q) of Hilbert fractal inductors with metal trace width, effective fractal length, frequency, and oxide thickness as input parameters. In contrast to the traditional feed forward neural network, the proposed FNNPSOGSA has been designed with fewer hidden neurons with much-enhanced learning and generalization capabilities. As a consequence, the proposed model achieves better speed and is as accurate as electromagnetic simulations. From the …

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An Enhanced Grey Wolf Optimization Algorithm With Improved Exploration Ability For Analog Circuit Design Automation, M A Mushahhid Majeed, Sreehari Rao Patri Jan 2018

An Enhanced Grey Wolf Optimization Algorithm With Improved Exploration Ability For Analog Circuit Design Automation, M A Mushahhid Majeed, Sreehari Rao Patri

Turkish Journal of Electrical Engineering and Computer Sciences

A novel circuit sizing technique with improved accuracy and efficiency is proposed to resolve the sizing issues in the analog circuit design. The grey wolf optimization (GWO) algorithm has the total number of iterations divided equally for exploration and exploitation, overlooking the impact of balance between these two phases, aimed for the convergence at a globally optimal solution. An enhanced version of a typical GWO algorithm termed as enhanced grey wolf optimization (EGWO) algorithm is presented with improved exploration ability and is successfully applied in analog circuit design. A set of 23 classical benchmark functions is evaluated and the outcomes …

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Design Of A Fractional Order Pid Controller With Application To An Induction Motor Drive, Ashraf Saleem, Hisham Soliman, Serein Al-Ratrout, Mostefa Mesbah Jan 2018

Design Of A Fractional Order Pid Controller With Application To An Induction Motor Drive, Ashraf Saleem, Hisham Soliman, Serein Al-Ratrout, Mostefa Mesbah

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a new method for designing a fractional-order proportional-integral-derivative (FO-PID) controller with an application to an induction motor drive is proposed. In the proposed method, the motor drive is modeled using an autoregressive with exogenous input (ARX) model whose parameters are experimentally identified using real I/O data. A genetic algorithm is then used to find the FO-PID parameters. To guarantee the robustness of the controller against load variations, minimax optimization is adopted. To validate the results, the proposed controller is applied to a real-life motor drive using a hardware-in-the-loop (HIL) simulator. The experimental results show that the proposed …

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Human Sleep Scoring Based On K-Nearest Neighbors, Shahnawaz Qureshi, Seppo Karrila, Sirirut Vanichayobon Jan 2018

Human Sleep Scoring Based On K-Nearest Neighbors, Shahnawaz Qureshi, Seppo Karrila, Sirirut Vanichayobon

Turkish Journal of Electrical Engineering and Computer Sciences

Human sleep is one of the essential indicators that gauge the overall health and well-being. Presently, it is common for people to face issues related to sleep. Various biomedical signals including electroencephalogram (EEG), electrooculography (EMG), and electrooculography (EOG) are utilized in the diagnosis and during the treatment of sleep disorder cases. An automatic classification to diagnose sleep problems can help in the analysis of sleep EEG data. In this current study, an effort is made to classify the sleep stages from a single EEG channel (C4-A1) based on K-nearest neighbors (K-NN) with three alternative distance metrics. The Euclidean distance is …

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Sign Language Recognition With Multi Feature Fusion And Ann Classifier, Sunitha Ravi, Maloji Suman, Polurie Venkata Vijay Kishore, Kiran Kumar Eepuri Jan 2018

Sign Language Recognition With Multi Feature Fusion And Ann Classifier, Sunitha Ravi, Maloji Suman, Polurie Venkata Vijay Kishore, Kiran Kumar Eepuri

Turkish Journal of Electrical Engineering and Computer Sciences

Extracting and recognizing complex human movements such as sign language gestures from video sequences is a challenging task. In this paper this kind of a difficult problem is approached with Indian sign language (ISL) videos. A new segmentation algorithm is developed by fusion of features from discrete wavelet transform (DWT) and local binary pattern (LBP). A 2D point cloud is formed from fused features, which represent the local hand shapes in consecutive video frames. We validate the proposed feature extraction model with state of the art features such as HOG, SIFT and SURF for each sign video on the same …

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Improved Method Of Heuristic Classification Of Vowels From An Acoustic Signal, Josef Krocil, Zdenek Machacek, Jiri Koziorek, Radek Martinek, Jan Nedoma, Marcel Fajkus Jan 2018

Improved Method Of Heuristic Classification Of Vowels From An Acoustic Signal, Josef Krocil, Zdenek Machacek, Jiri Koziorek, Radek Martinek, Jan Nedoma, Marcel Fajkus

Turkish Journal of Electrical Engineering and Computer Sciences

This paper describes research in the field of the improved methodology of the classification of vowels /a, a:/, /$\varepsilon$, $\varepsilon$:/, /ı, i:/, /o, o:/, and /u, u:/ (vowel symbols according to IPA, i.e. International Phonetic Alphabet). The aim is to develop an improved method enabling the automatic allocation of vowel symbols to the corresponding time segments of acoustic recordings of an undisturbed speech signal. The combined classification method is based on finding frequencies of the first two local maxims (formants) in a smoothed linear predictive amplitude spectrum (LPC, linear predictive coding) and zero-crossing values of each speech active voiced short-term …

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Fpga Implementation Of A Low-Power And Area-Efficient State-Table-Based Compression Algorithm For Dslr Cameras, Mohd Rafi Lone, Najeeb Ud Din Hakim Jan 2018

Fpga Implementation Of A Low-Power And Area-Efficient State-Table-Based Compression Algorithm For Dslr Cameras, Mohd Rafi Lone, Najeeb Ud Din Hakim

Turkish Journal of Electrical Engineering and Computer Sciences

Small image acquisition devices like digital single lens reflex (DSLR) cameras most commonly use Joint Photographic Expects Group (JPEG) coding standard for lossy compression. Although JPEG is a simple coding standard, its compression efficiency is very low as compared to any typical state-of-the-art image coding standards like set partitioning in hierarchical trees (SPIHT). In this paper, a novel state-table-based SPIHT (STS) algorithm and its field programmable gate array (FPGA) implementation is proposed. The STS uses two small state-tables and two extremely small lists. The STS not only provides better compression efficiency than the state-of-the-art JPEG 2000 at high bit rates …

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Path Loss Model For Indoor Emergency Stairwell Environment At Millimeter Wave Band For 5g Network, Ahmed Mohammed Alsamman, Tharek Abd Rahman, Mohd Nour Hindia, Jamal Nasir Jan 2018

Path Loss Model For Indoor Emergency Stairwell Environment At Millimeter Wave Band For 5g Network, Ahmed Mohammed Alsamman, Tharek Abd Rahman, Mohd Nour Hindia, Jamal Nasir

Turkish Journal of Electrical Engineering and Computer Sciences

The unused millimeter-wave (mmWave) spectrum offers a superb opportunity to increase mobile broadband capacity due to the enormous amount of available bandwidth. Different candidate operating frequencies for 5G wireless networks are available at the mmWave band. For 5G wireless networks, the emergency case is one of the applications. This paper presents the outcome of indoor emergency stairwell measurement campaigns for 5G system at 26 GHz, 28 GHz, 32 GHz, and 38 GHz, which were conducted at the University Technology Malaysia, Kuala Lumpur, Malaysia. To effectively evaluate the performance of 5G wireless systems in these different bands, single- and multifrequency path …

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Artificial Immune System Based Wastewater Parameter Estimation, Cengi̇z Sertkaya, Ni̇lüfer Yurtay Jan 2018

Artificial Immune System Based Wastewater Parameter Estimation, Cengi̇z Sertkaya, Ni̇lüfer Yurtay

Turkish Journal of Electrical Engineering and Computer Sciences

The basis of a wastewater treatment system is to achieve the desired characteristics of the wastewater treatment process. An estimation of the obtained wastewater treatment characteristics provides the information needed to set up the current process steps, and it is important to have an optimum treatment. In this study, an artificial immune system (AIS) structure is developed to estimate important wastewater output parameters such as pH, DBO, DQO, and SS for the first time. The proposed AIS models are based on the clonal selection principle, and the dataset is provided from the University of California Irvine (UCI) Machine Learning Library. …

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Horizontal Diversity In Test Generation For High Fault Coverage, Arbab Alamgir, Abu Khari Bin A'Ain, Norlina Paraman, Usman Ullah Sheikh, Ian Grout Jan 2018

Horizontal Diversity In Test Generation For High Fault Coverage, Arbab Alamgir, Abu Khari Bin A'Ain, Norlina Paraman, Usman Ullah Sheikh, Ian Grout

Turkish Journal of Electrical Engineering and Computer Sciences

Determination of the most appropriate test set is critical for high fault coverage in testing of digital integrated circuits. Among black-box approaches, random testing is popular due to its simplicity and cost effectiveness. An extension to random testing is antirandom that improves fault detection by maximizing the distance of every subsequent test pattern from the set of previously applied test patterns. Antirandom testing uses total Hamming distance and total cartesian distance as distance metrics to maximize diversity in the testing sequence. However, the algorithm for the antirandom test set generation has two major issues. Firstly, there is no selection criteria …

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Computational Fluid Dynamics Modeling Of The Climate Inside A Chicken House, Nuttaphon Kanjanaudomsuk Jan 2018

Computational Fluid Dynamics Modeling Of The Climate Inside A Chicken House, Nuttaphon Kanjanaudomsuk

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, most of chicken products are from a closed house system. Climate inside such chicken house can significantly affect chicken welfare and its productivity. Moreover, Thailand is in a tropical region where thermal stress is easily occurred. Suitable operating condition and chicken house design can help improve interior climate which can be evaluated by computational fluid dynamics (CFD) modeling technique. In this study, realizable k-ε model, energy conservation and species transport equations were applied to simulate the air velocity, temperature and relative humidity, respectively, inside the chicken house. The model was validated with measured air velocity, temperature and relative humidity …

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Design Of Solid Oxide Fuel Cell-Molten Carbonate Fuel Cell Combined System For Power Generation And Carbon Dioxide Emission Reduction, Prathak Jienkulsawad Jan 2018

Design Of Solid Oxide Fuel Cell-Molten Carbonate Fuel Cell Combined System For Power Generation And Carbon Dioxide Emission Reduction, Prathak Jienkulsawad

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research concentrates on the design and performance analysis of a solid oxide fuel cell (SOFC) and a molten carbonate fuel cell (MCFC) integrated system with using methane as fuel. Because SOFCs cannot completely use their fuel, there is remaining fuel leaving the system. In addition, the exhaust gas from an SOFC can be directly fed into an MCFC. The integrated fuel cell system shows an electrical efficiency of 55.22%, which is higher than a single fuel cell system. Fuel utilization of both fuel cells, SOFC temperature dramatically affect the performance of the integrated system. Four configurations were next proposed …

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Synthesis Of Black Titanium Dioxide And Effect Of Calcination Conditions And Reducing Agent On Photocatalytic Degradation Of Methyl Orange, Saran Saensook Jan 2018

Synthesis Of Black Titanium Dioxide And Effect Of Calcination Conditions And Reducing Agent On Photocatalytic Degradation Of Methyl Orange, Saran Saensook

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research studied the synthesis and application of black titanium dioxide in the photocatalytic degradation of methyl orange (MO). First, titanium dioxide was prepared via a sol-gel method. Then sodium borohydride was used as the reducing agent in order to synthesize black titanium dioxide. Thus, a 2x2x3 factorial experimental design was employed to assess the significance of the following three factors: (A) calcination temperature (400 and 500 °C); (B) calcination time (5 and 10 h); and (C) the molar ratio of NaBH4 to TiO2 used (0:1, 0.5:1, and 1:1). The removal of MO under UV and visible light were the …

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Carbon Dioxide Capture On Nitrogen-Doped Carbon Nanoparticle Derived From Aromatic Compounds Via Solution Plasma And Nitridation, Phuwadej Pornaroontham Jan 2018

Carbon Dioxide Capture On Nitrogen-Doped Carbon Nanoparticle Derived From Aromatic Compounds Via Solution Plasma And Nitridation, Phuwadej Pornaroontham

Chulalongkorn University Theses and Dissertations (Chula ETD)

The carbon dioxide (CO2) adsorption on nanocarbon (C), oxygen-doped nanocarbon synthesized from benzene and a mixture of benzene and metal working fluid (MWF), respectively, via solution plasma process (SPP) have been revealed in this study. Firstly, they showed low CO2 adsorption capacity at 25 °C. However, their capacities were enhanced by nitridation under ammonia atmosphere at high temperature. The maximum CO2 adsorption capacity of 1.63 mmol g-1 was achieved on nitrogen-oxygen-codoped nanocarbon obtained from SPP discharging a mixture containing 15 vol% MWF nitrided at 800 °C (noC15(800)). The characterizations revealed that the micropososity and nitrogen functionality on the adsorbent are …

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Computational Fluid Dynamics Of Fluid Transport And Deposition Of Particles Under Unsteady Flow In Human Fluid System, Ratchanon Piemjaiswang Jan 2018

Computational Fluid Dynamics Of Fluid Transport And Deposition Of Particles Under Unsteady Flow In Human Fluid System, Ratchanon Piemjaiswang

Chulalongkorn University Theses and Dissertations (Chula ETD)

Computational fluid dynamics has been widely used to investigate flow phenomena in many different applications. This study focuses on the development of computational fluid dynamic model in biomedical applications, including the flow within human respiratory system and the flow within human circulating system. For the model of respiratory system, electrostatic charge model was coupled, and the effect of breathing frequency was investigated. The accomplishment of the study will gain better understanding of the hydrodynamics when applying the electrostatic field, and will use to identify the potential aerosol deposition location. The aerosol properties and morphologies were also considered their effect on …

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Development Of Optical Sensor For Detection Of Chloride Ions And Electrochemical Sensor For Detection Of Clinical Indicators, Abdulhadee Yakoh Jan 2018

Development Of Optical Sensor For Detection Of Chloride Ions And Electrochemical Sensor For Detection Of Clinical Indicators, Abdulhadee Yakoh

Chulalongkorn University Theses and Dissertations (Chula ETD)

This dissertation concentrated on the development of nanomaterials-based miniaturized platforms for the detection of some important compounds/indicators from environmental, pharmaceutical, and clinical application. This dissertation can be classified into two main parts: (1) development of nanomaterials-based miniaturized platforms for optical sensing application, and (2) development of nanomaterials-based miniaturized platforms for electrochemical sensing applications. In the first part, two sub-sections were discussed. For the first sub-section, the paper-based colorimetric sensor for chloride ion determination using silver nanoprisms was developed. Using a smartphone as an optical readout, the color change from the oxidative etching of the silver nanoprisms to the silver nanospheres …

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