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2020

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Articles 14761 - 14790 of 15205

Full-Text Articles in Physical Sciences and Mathematics

Low Harmonic 12-Pulse Rectifier With A Circulating Current Shaping Circuit, Jingfang Wang, Xuliang Yao, Qi Guan, Changji Deng, Shiyan Yang Jan 2020

Low Harmonic 12-Pulse Rectifier With A Circulating Current Shaping Circuit, Jingfang Wang, Xuliang Yao, Qi Guan, Changji Deng, Shiyan Yang

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a four-star 12-pulse diode rectifier with a circulating current shaping circuit (CCSC) on the DC side to decrease the input current harmonics effectively. The type of circulating current that can eliminate the input current harmonics is analysed and its waveform parameters are derived. The effects of triangular circulating current on the harmonics of the input current are analysed, and the harmonic suppression mechanism of the triangular circulating current is revealed. This scheme has excellent harmonic suppression capability, and the capacity of CCSC is only 2.35% of output power of the 12-pulse rectifier. Thus, this scheme is cost …

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Deep Temporal Motion Descriptor (Dtmd) For Human Action Recognition, Nudrat Nida, Muhammad Haroon Yousaf, Aun Irtaza, Sergio A. Velastin Jan 2020

Deep Temporal Motion Descriptor (Dtmd) For Human Action Recognition, Nudrat Nida, Muhammad Haroon Yousaf, Aun Irtaza, Sergio A. Velastin

Turkish Journal of Electrical Engineering and Computer Sciences

Spatiotemporal features have significant importance in human action recognition, as they provide the actor's shape and motion characteristics specific to each action class. This paper presents a new deep spatiotemporal human action representation, the deep temporal motion descriptor (DTMD), which shares the attributes of holistic and deep learned features. To generate the DTMD descriptor, the actor?s silhouettes are gathered into single motion templates by applying motion history images. These motion templates capture the spatiotemporal movements of the actor and compactly represent the human actions using a single 2D template. Then deep convolutional neural networks are used to compute discriminative deep …

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Deep Neural Network Based M-Learning Model For Predicting Mobile Learners'performance, Muhammad Adnan, Asad Habib, Jawad Ashraf, Shafaq Mussadiq, Arsalan Ali Jan 2020

Deep Neural Network Based M-Learning Model For Predicting Mobile Learners'performance, Muhammad Adnan, Asad Habib, Jawad Ashraf, Shafaq Mussadiq, Arsalan Ali

Turkish Journal of Electrical Engineering and Computer Sciences

The use of deep learning (DL) techniques for mobile learning is an emerging field aimed at developing methods for finding mobile learners' learning behavior and exploring important learning features. The learning features (learning time, learning location, repetition rate, content types, learning performance, learning time duration, and so on) act as fuel to DL algorithms based on which DL algorithms can classify mobile learners into different learning groups. In this study, a powerful and efficient m-learning model is proposed based on DL techniques to model the learning process of m-learners. The proposed m-learning model determines the impact of independent learning features …

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Feature Points-Based Image Registration Between Satellite Imagery And Aerialimages Of Agricultural Land, Mohsin Abbas, Sajid Saleem, Fazli Subhan, Abdul Bais Jan 2020

Feature Points-Based Image Registration Between Satellite Imagery And Aerialimages Of Agricultural Land, Mohsin Abbas, Sajid Saleem, Fazli Subhan, Abdul Bais

Turkish Journal of Electrical Engineering and Computer Sciences

Rapid advancement in remote sensing sensors has resulted in an enormous increase in the use of satellite imagery (SI) and images taken from unmanned aerial vehicles (UAVs) in a wide range of remote sensing applications. These applications include urban planning, environment monitoring, map updating, change detection, and precision agriculture. This paper focuses on an agricultural application of SI and UAV images. SI-UAV images possess high temporal, textural, and intensity differences due to rapid changes in agricultural crops with the passage of time. Feature points such as scale invariant feature transform (SIFT), oriented FAST and rotated BRIEF (ORB), and speeded-up robust …

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Implicit Relation-Based Question Answering To Answer Simple Questions Overdbpedia, Maryam Jamehshourani, Afsaneh Fatemi, Mohammadali Nematbakhsh Jan 2020

Implicit Relation-Based Question Answering To Answer Simple Questions Overdbpedia, Maryam Jamehshourani, Afsaneh Fatemi, Mohammadali Nematbakhsh

Turkish Journal of Electrical Engineering and Computer Sciences

RDF-based question answering systems give users the capability of natural language querying over RDF data. In order to respond to natural language questions, it is necessary that the main concept of the question be interpreted correctly, and then it is mapped to RDF data. A natural language question includes entities, classes, and implicit and explicit relationships. In this article, by focusing on identification and mapping of implicit relationships in the question (in addition to the explicit relationships), the mapping step has been improved. In the proposed solution (IRQA), entities and implicit/explicit relationships are identified by means of the provided rules …

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Superconducting Radio-Frequency Cavity Fault Classification Using Machine Learning At Jefferson Laboratory, Chris Tennant, Adam Carpenter, Tom Powers, Anna Shabalina Solopova, Lasitha Vidyaratne, Khan Iftekharuddin Jan 2020

Superconducting Radio-Frequency Cavity Fault Classification Using Machine Learning At Jefferson Laboratory, Chris Tennant, Adam Carpenter, Tom Powers, Anna Shabalina Solopova, Lasitha Vidyaratne, Khan Iftekharuddin

Electrical & Computer Engineering Faculty Publications

We report on the development of machine learning models for classifying C100 superconducting radio-frequency (SRF) cavity faults in the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab. CEBAF is a continuous-wave recirculating linac utilizing 418 SRF cavities to accelerate electrons up to 12 GeV through five passes. Of these, 96 cavities (12 cryomodules) are designed with a digital low-level rf system configured such that a cavity fault triggers waveform recordings of 17 rf signals for each of the eight cavities in the cryomodule. Subject matter experts are able to analyze the collected time-series data and identify which of the …

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Fault Identification Of Catenary Dropper Based On Improved Capsnet, Jianpeng Bian, Jiaxing Hao, Shuai Zhao, Weijing Hua, Shichuang Gao Jan 2020

Fault Identification Of Catenary Dropper Based On Improved Capsnet, Jianpeng Bian, Jiaxing Hao, Shuai Zhao, Weijing Hua, Shichuang Gao

Turkish Journal of Electrical Engineering and Computer Sciences

Traditional fault identification algorithms applied to catenary dropper suffer from various problems due to its small contact area. These problems include misidentification and lower recognition rate of the faulty dropper. Compared with the traditional convolutional neural network, the vector is utilized as the input of the capsule network (CapsNet) for the first time, which can well retain the feature information such as the direction and angle of the target, and is more suitable for identifying the dropper under complex background. Therefore, this paper proposes a dropper fault identification algorithm based on improved capsule network. The convolutional layer of traditional 9×9 …

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A Fabrication-Oriented Remeshing Method For Auxetic Pattern Extraction, Levend Mehmet Mert, Ulaş Yaman, Yusuf Sahi̇lli̇oğlu Jan 2020

A Fabrication-Oriented Remeshing Method For Auxetic Pattern Extraction, Levend Mehmet Mert, Ulaş Yaman, Yusuf Sahi̇lli̇oğlu

Turkish Journal of Electrical Engineering and Computer Sciences

We propose a method for extracting auxetic patterns from meshes for fabrication by modifying the existing mesh primitives directly and fully automatically. This direct approach is novel in the sense that most of the fabricationoriented surface tiling methods introduce additional primitives, such as curve networks in an interactive semiautomatic framework. Our method is based on a remeshing procedure that converts a given quad mesh with arbitrary topology into our desired structure that is ready to be fabricated. The main advantages of establishing auxetic patterns on meshes are the achieved flexibility using cheap inflexible materials as well as less material usage …

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User Profiling For Tv Program Recommendation Based On Hybrid Televisionstandards Using Controlled Clustering With Genetic Algorithms And Artificial Neuralnetworks, İhsan Topalli, Selçuk Kilinç Jan 2020

User Profiling For Tv Program Recommendation Based On Hybrid Televisionstandards Using Controlled Clustering With Genetic Algorithms And Artificial Neuralnetworks, İhsan Topalli, Selçuk Kilinç

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, an earlier method proposed by the authors to make smart recommendations utilizing artificial intelligence and the latest technologies developed for the television area is expanded further using controlled clustering with genetic algorithms (CCGA). For this purpose, genetic algorithms (GAs), artificial neural networks (ANNs), and hybrid broadcast broadband television (HbbTV) are combined to get the users' television viewing habits and to create profiles. Then television programs are recommended to the users based on that profiling. The data gathered by the developed HbbTV application for previous studies are reused in this study. These data are employed to cluster users. …

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Nonlinear Adaptive Semiactive Control Of A Half-Vehicle Model Via Hardware In The Loop Simulation, Mahmut Paksoy, Muzaffer Meti̇n Jan 2020

Nonlinear Adaptive Semiactive Control Of A Half-Vehicle Model Via Hardware In The Loop Simulation, Mahmut Paksoy, Muzaffer Meti̇n

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, vehicle body vibrations are semiactively controlled using a nonlinear adaptive controller designed to improve passenger comfort by guaranteeing closed loop system stability under variable road disturbances with parametric uncertainty. Semiactive vibration control is implemented to the system through the magnetorheological damper. The MR damper test system is established in laboratory conditions, and the required values that are measured from the test system are used in computer simulations via the hardware in the loop simulation (HILS) method. By this way, it is possible to avoid the financial and other difficulties of the experimental study by establishing the test …

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A New Semiempirical Model Determining The Dielectric Characteristics Of Citrusleaves For The Remote Sensing At C Band, Abdullah Genç, Habi̇b Doğan, İbrahi̇m Bahadir Başyi̇ği̇t Jan 2020

A New Semiempirical Model Determining The Dielectric Characteristics Of Citrusleaves For The Remote Sensing At C Band, Abdullah Genç, Habi̇b Doğan, İbrahi̇m Bahadir Başyi̇ği̇t

Turkish Journal of Electrical Engineering and Computer Sciences

Dielectric parameters (i.e. permittivity) are fundamental to the simulation, design, modeling, and developing of microwave applications. For targeted objects, the complex permittivity is an essential parameter that affects its characteristics of scattering and microwave radiation. Thus, in microwave remote sensing applications, the knowledge of the dielectric property of vegetable materials is used not only to detect planting areas for monitoring and to able to specify the growth stage of them in seasonal variations, but also to determine the water requirement of the plant for controlling (water stress). This paper focuses on determining the dielectric parameters of orange and lemon leaves, …

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Wideband Patch Array Antenna Using Superstrate Configuration For Future 5gapplications, Sidra Farhat, Farzana Arshad, Yasar Amin, Jonathan Loo Jan 2020

Wideband Patch Array Antenna Using Superstrate Configuration For Future 5gapplications, Sidra Farhat, Farzana Arshad, Yasar Amin, Jonathan Loo

Turkish Journal of Electrical Engineering and Computer Sciences

In this work, four distinct antenna configurations for future-centric 5G applications are proposed. Initially, a single rectangular patch is designed to operate at the frequency of 28 GHz while maintaining a wide operational band. Performance of the antenna is improved by incorporating an array of identical rectangular elements resulting in a higher gain and wider bandwidth. The proposed arrangement consists of three rectangular elements realized using 0.508-mm thick Rogers RT/Duroid 5880 laminate. The bandwidth is further enhanced by increasing the number of radiating elements in the array from three to five. Evolution of the proposed design is concluded by stacking …

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On Efficient Computation Of Equilibrium Under Social Coalition Structures, Buğra Çaşkurlu, Özgün Eki̇ci̇, Fati̇h Erdem Kizilkaya Jan 2020

On Efficient Computation Of Equilibrium Under Social Coalition Structures, Buğra Çaşkurlu, Özgün Eki̇ci̇, Fati̇h Erdem Kizilkaya

Turkish Journal of Electrical Engineering and Computer Sciences

In game-theoretic settings the key notion of analysis is an equilibrium, which is a profile of agent strategies such that no viable coalition of agents can improve upon their coalitional welfare by jointly changing their strategies. A Nash equilibrium, where viable coalitions are only singletons, and a super strong equilibrium, where every coalition is deemed viable, are two extreme scenarios in regard to coalition formation. A recent trend in the literature is to consider equilibrium notions that allow for coalition formation in between these two extremes and which are suitable to model social coalition structures that arise in various real-life …

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Human Activity Recognition By Using Mhis Of Frame Sequences, Saeedeh Zebhi, Smt Almodarresi, Vahid Abootalebi Jan 2020

Human Activity Recognition By Using Mhis Of Frame Sequences, Saeedeh Zebhi, Smt Almodarresi, Vahid Abootalebi

Turkish Journal of Electrical Engineering and Computer Sciences

A motion history image (MHI) is a temporal template that collapses temporal motion information into a single image in which intensity is a function of recency of motion. In recent years, the popularity of deep learning architectures for human activity recognition has encouraged us to explore the effectiveness of combining them and MHIs. Based on this, two new methods are introduced in this paper. In the first method, which is called the basic method, each video splits into N groups of consecutive frames, and the MHI is calculated for each group. Transfer learning with the fine-tuning technique is used for …

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A Ga-Based Adaptive Mechanism For Sensorless Vector Control Of Induction Motor Drives For Urban Electric Vehicles, Asma Boulmane, Youssef Zidani, Driss Belkhayat, Marouane Bouchouirbat Jan 2020

A Ga-Based Adaptive Mechanism For Sensorless Vector Control Of Induction Motor Drives For Urban Electric Vehicles, Asma Boulmane, Youssef Zidani, Driss Belkhayat, Marouane Bouchouirbat

Turkish Journal of Electrical Engineering and Computer Sciences

Induction motors are more attractive to car manufacturers because they are more robust and more cost effective to maintain in comparison with other types of electric machines. The evolution of their control makes them more efficient and less expensive. However, a new control technique known as sensorless control is being used to simplify the implementation of electric machines in electric vehicles. This technique involves replacing the flux and speed sensors with an observer. The estimation of these elements is based on the measurement of currents and voltages. The main purpose of the present study is to design a novel robust …

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A Template-Based Code Generator For Web Applications, Burak Uyanik, Veysel Harun Şahi̇n Jan 2020

A Template-Based Code Generator For Web Applications, Burak Uyanik, Veysel Harun Şahi̇n

Turkish Journal of Electrical Engineering and Computer Sciences

The importance and usage of web applications grow every day. Today from small businesses to large-scale corporations, many institutions prefer web applications for both their internal and external services. Code size and complexity of these kinds of applications grow rapidly. This brings up the question of how to improve the development process of web applications. A solution can be to use code generators. This paper introduces a template-based code generator to improve the development process of web applications. The code generator was developed and integrated into a real-life web application. Today, the web application together with the code generator is …

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Plane Wave Diffraction By Strip With An Integral Boundary Condition, Kami̇l Karaçuha, Vasil Tabatadze, Eldar Ismailovich Veliev Jan 2020

Plane Wave Diffraction By Strip With An Integral Boundary Condition, Kami̇l Karaçuha, Vasil Tabatadze, Eldar Ismailovich Veliev

Turkish Journal of Electrical Engineering and Computer Sciences

In this article, a new solution method is proposed for plane wave diffraction by a strip. On the surface of the strip, an integral boundary condition is used. The impedance of the strip is investigated. The theoretical and numerical analyses show that there is a relation between the complex-valued fractional order of the integral boundary condition and properties of the material such as the impedance. As a further study, the total radar cross-section is investigated using the proposed method.

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An Alternative Method Of Biomedical Signal Transmission Through The Gsm Voice Channel, Seyedmohsen Dehghan, Mehmet Kaya Jan 2020

An Alternative Method Of Biomedical Signal Transmission Through The Gsm Voice Channel, Seyedmohsen Dehghan, Mehmet Kaya

Turkish Journal of Electrical Engineering and Computer Sciences

In this work, a new solution for online and accurate biomedical data transmission is presented. For this purpose, a global system for mobile (GSM) communication voice channel is, for the first time, used as a communication link between the patient and healthcare provider. Biomedical signals are converted into speech-like signals before being transferred over a GSM voice channel. On the receiver side, speech-like symbols are stored in a symbols bank, and constructed using random stochastic signals. On the receiver end, the index of the symbol with the most similarity to the received signal is selected as the identified sample. This …

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Facest: Feedback-Assisted Estimation Of End-To-End Capacity In Ip-Basedcommunication Networks, Fati̇h Abut Jan 2020

Facest: Feedback-Assisted Estimation Of End-To-End Capacity In Ip-Basedcommunication Networks, Fati̇h Abut

Turkish Journal of Electrical Engineering and Computer Sciences

The end-to-end capacity, defined as the maximal transmission rate of the weakest link on the entire path between two end hosts, plays an important role in efficient network design and management. Although various capacity estimation tools have been proposed in the literature, there is still uncertainty in their accuracy and reliability when they are used in today's IP-based communication networks. The main reason for this is that all current capacity estimation tools only yield a potential candidate for an acceptable estimate, without being aware of its reliability level. In this study, we propose a new feedback-assisted end-to-end capacity estimation (FACEST) …

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Assessment Of Environmental Factors Affecting Software Reliability: A Survey Study, Alper Özcan, Çağatay Çatal, Cengi̇z Toğay, Bedi̇r Teki̇nerdoğan, Emrah Dönmez Jan 2020

Assessment Of Environmental Factors Affecting Software Reliability: A Survey Study, Alper Özcan, Çağatay Çatal, Cengi̇z Toğay, Bedi̇r Teki̇nerdoğan, Emrah Dönmez

Turkish Journal of Electrical Engineering and Computer Sciences

Currently, many systems depend on software, and software reliability as such has become one of the key challenges. Several studies have been carried out that focus on the impact of external environmental factors that impact software reliability. These studies, however, were all carried out in the same geographical context. Given the rapid developments in software engineering, this study aims to identify and reinvestigate the environmental factors that impact software reliability by also considering a different context. The environmental factors that have an impact on software reliability as reported in earlier studies have been analyzed and synthesized. Subsequently, a survey study …

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Zeki: Unsupervised Zero-Day Exploit Kit Intelligence, Emre Süren Jan 2020

Zeki: Unsupervised Zero-Day Exploit Kit Intelligence, Emre Süren

Turkish Journal of Electrical Engineering and Computer Sciences

Over the last few years, exploit kits (EKs) have become the de facto medium for large-scale spread of malware. Drive-by download is the leading method that is widely used by EK flavors to exploit web-based client-side vulnerabilities. Their principal goal is to infect the victim's system with a malware. In addition, EK families evolve quickly, where they port zero-day exploits for brand new vulnerabilities that were never seen before and for which no patch exists. In this paper, we propose a novel approach for categorizing malware infection incidents conducted through EKs by leveraging the inherent "overall URL patterns" in the …

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Remac: A Novel Hybrid And Reservation-Based Mac Protocol For Vanets, Fi̇kri̇ Ağgün, Musa Çibuk, Shafqat Ur Rehman Jan 2020

Remac: A Novel Hybrid And Reservation-Based Mac Protocol For Vanets, Fi̇kri̇ Ağgün, Musa Çibuk, Shafqat Ur Rehman

Turkish Journal of Electrical Engineering and Computer Sciences

The period in which a roadside unit (RSU) of a vehicle remains in the coverage area is too short in vehicular ad hoc networks (VANETs) in which the vehicles move at high speeds. In this short period, it is necessary for the vehicles to join the network and establish continuous communication with the RSU. To accomplish this, the RSU and vehicles need an efficient and robust media access control (MAC) protocol. In this study, a new reservation-based MAC (ReMAC) protocol in which multiple channels are used is suggested to ensure rapid connection to RSUs, smooth transition between RSUs, and efficient …

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Quasi-Physical Modeling Of Robot Irb 120 Using Simscape Multibody For Dynamicand Control Simulation, Truc Le Ngoc, Tung Lam Nguyen Jan 2020

Quasi-Physical Modeling Of Robot Irb 120 Using Simscape Multibody For Dynamicand Control Simulation, Truc Le Ngoc, Tung Lam Nguyen

Turkish Journal of Electrical Engineering and Computer Sciences

The mathematical model of robot that is used to design control algorithms is mostly reused in numerical simulations as a virtual plant. The use of same model for both control design and simulation tasks makes the outcome idealized. Consequently, the effectiveness and feasibility of designed control methodologies when applied in practice seem to be questionable. The paper presents the quasi-physical modeling of a 6-DOF robot using MATLAB/Simscape Multibody for dynamic and control simulation. The bodies of the robot are assembled into a physical network with connections that represent physical domains. The dynamical manners of the quasi-physical model are close to …

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Improvement Of The Distribution Network State Estimation With Increase Ofaccurate Information And Using A Two-Step Method, Karim Amiri, Rasool Kazemzadeh Jan 2020

Improvement Of The Distribution Network State Estimation With Increase Ofaccurate Information And Using A Two-Step Method, Karim Amiri, Rasool Kazemzadeh

Turkish Journal of Electrical Engineering and Computer Sciences

Distribution networks (DNs) are gradually changing and this makes their control and utilization complicated. State estimation (SE) plays a significant role in active distribution networks. The performance of the energy management center in modern distribution networks is highly dependent on the results obtained from the SE. In the present study, considering the shortage of measurements in the DN, a two-step state estimation method with a new network reduction process (NRP) is proposed. In the proposed method, a new NRP is used in a two-step state estimation method to improve the performance of SE in a DN. Obtaining accurate initial information …

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Abiotic Formation Of Dissolved Organic Sulfur In Anoxic Sediments Of Santa Barbara Basin, Hussain A. Abdulla, David J. Burdige, Tomoko Komada Jan 2020

Abiotic Formation Of Dissolved Organic Sulfur In Anoxic Sediments Of Santa Barbara Basin, Hussain A. Abdulla, David J. Burdige, Tomoko Komada

OES Faculty Publications

Sulfurization has been found to enhance organic matter preservation and petroleum formation in marine sediments. However, we do not yet have a comprehensive understanding of sulfurization mechanisms. In this study, we investigated several possible mechanisms of dissolved organic sulfur (DOS) formation in the top 4.5 m of anoxic sediments of Santa Barbara Basin (SBB), California Borderland. Using Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FTICR-MS), we identified chemical formulas of potential dissolved organic matter (DOM) precursors to these DOS compounds. We also examined how the formulas of abiotically formed DOS changed as a function of depth across a major redox …

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Sketic: A Machine Learning-Based Digital Circuit Recognition Platform, Mohamamd Abdel Majeed, Tasneem Almousa, Maysaa Alsalman, Abeer Yosef Jan 2020

Sketic: A Machine Learning-Based Digital Circuit Recognition Platform, Mohamamd Abdel Majeed, Tasneem Almousa, Maysaa Alsalman, Abeer Yosef

Turkish Journal of Electrical Engineering and Computer Sciences

In digital system design, digital logic circuit diagrams are built using interconnects and symbolic representations of the basic logic gates. Constructing such diagrams using free sketches is the first step in the design process. After that the circuit schematic or code has to be generated before being able to simulate the design. While most of the mentioned steps are automated using design automation tools, drafting the schematic circuit and then converting it into a valid format that can be simulated are still done manually due to the lack of robust tools that can recognize the free sketches and incorporate them …

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An Efficient Reliability Simulation Tool For Lifetime-Aware Analog Circuit Synthesis, Engi̇n Afacan Jan 2020

An Efficient Reliability Simulation Tool For Lifetime-Aware Analog Circuit Synthesis, Engi̇n Afacan

Turkish Journal of Electrical Engineering and Computer Sciences

Time-dependent degradation (aging) has become more severe in modern CMOS technologies. Therefore, it is highly critical to capture the variation effects and design reliable circuits against aging. Simulation of time-dependent variations is quite complicated since the degradation is a function of time, where the step count of simulation directly affects the accuracy and the efficiency of the analysis. Commercial simulator tools use a constant step count during reliability simulations, in which choosing a large step count degrades the efficiency whereas keeping it small may result in accuracy problems. To overcome this bottleneck, a couple of different approaches have been proposed …

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Transmit Antenna Selection Schemes For Stbc-Sm, Belal Asaati, Ammar Abu Hudrouss Jan 2020

Transmit Antenna Selection Schemes For Stbc-Sm, Belal Asaati, Ammar Abu Hudrouss

Turkish Journal of Electrical Engineering and Computer Sciences

The coupling of space-time block codes (STBCs) with the spatial modulation (SM) scheme can introduce a spatial diversity to the SM systems. This paper presents antenna selection techniques to provide an additional coding gain with the space-time block coded spatial modulation (STBC-SM). Specifically, the selection of optimal transmit antenna elements at the transmitter to send a spatially modulated space-time block code is studied. This paper studies the effects of applying the capacity optimized antenna selection (COAS) algorithm with the STBC-SM. The COAS algorithm has a suboptimal performance with a trade-off between complexity and bit-error-rate (BER) enhancement. Simulation results for STBC-SM …

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Deep Equatorial Pacific Ocean Oxygenation And Atmospheric Co2 Over The Last Ice Age, Franco Marcantonio, Ryan Hostak, Jennifer E. Hertzberg, Matthew W. Schmidt Jan 2020

Deep Equatorial Pacific Ocean Oxygenation And Atmospheric Co2 Over The Last Ice Age, Franco Marcantonio, Ryan Hostak, Jennifer E. Hertzberg, Matthew W. Schmidt

OES Faculty Publications

Ventilation of carbon stored in the deep ocean is thought to play an important role in atmospheric CO2 increases associated with Pleistocene deglaciations. The presence of this respired carbon has been recorded by an array of paleoceanographic proxies from various locations across the global ocean. Here we present a new sediment core from the Eastern Equatorial Pacific (EEP) Ocean spanning the last 180,000 years and reconstruct high-resolution 230Th-derived fluxes of 232Th and excess barium, along with redox-sensitive uranium concentrations to examine past variations in dust delivery, export productivity, and bottom-water oxygenation, respectively. Our bottom-water oxygenation record is compared to …

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Metabolic Profiling Reveals Biochemical Pathways Responsible For Eelgrass Response To Elevated Co2 And Temperature, Carmen C. Zayas-Santiago, Albert Rivas-Ubach, Li-Jung Kuo, Nicholas D. Ward, Richard C. Zimmerman Jan 2020

Metabolic Profiling Reveals Biochemical Pathways Responsible For Eelgrass Response To Elevated Co2 And Temperature, Carmen C. Zayas-Santiago, Albert Rivas-Ubach, Li-Jung Kuo, Nicholas D. Ward, Richard C. Zimmerman

OES Faculty Publications

As CO2 levels in Earth’s atmosphere and oceans steadily rise, varying organismal responses may produce ecological losers and winners. Increased ocean CO2 can enhance seagrass productivity and thermal tolerance, providing some compensation for climate warming. However, the metabolic shifts driving the positive response to elevated CO2 by these important ecosystem engineers remain unknown. We analyzed whole-plant performance and metabolic profiles of two geographically distinct eelgrass (Zostera marina L.) populations in response to CO2 enrichment. In addition to enhancing overall plant size, growth and survival, CO2 enrichment increased the abundance of Calvin Cycle and …

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