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2020

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Articles 14911 - 14940 of 15205

Full-Text Articles in Physical Sciences and Mathematics

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 …


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 …


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 …


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 …


Passenger Scoring For Free-Pass Promotion In Public Transportation, Ufuk Demi̇r Alan, Derya Bi̇rant Jan 2020

Passenger Scoring For Free-Pass Promotion In Public Transportation, Ufuk Demi̇r Alan, Derya Bi̇rant

Turkish Journal of Electrical Engineering and Computer Sciences

The focus of promotions targeted to increase the use of public transportation concentrates on increasing the attractiveness of it, particularly by decreasing transportation fares. To serve that purpose, this paper proposes a novel passenger scoring model, namely RFLT (recency, frequency, loyalty, and time), for offering a free-pass promotion in public transportation. It presents the comparison results of RFLT and wRFLT (weighted version) using a real-world dataset obtained by a near field communication (NFC) mobile payment application. The experimental results show that the w-RFLT model provides a more balanced score distribution than the RFLT model, and the frequency parameter (F), among …


A Content-Based Recommender System For Choosing Universities, Miftahul Jannat Mokarrama, Sumi Khatun, Mohammad Shamsul Arefin Jan 2020

A Content-Based Recommender System For Choosing Universities, Miftahul Jannat Mokarrama, Sumi Khatun, Mohammad Shamsul Arefin

Turkish Journal of Electrical Engineering and Computer Sciences

Recommender system (RS) is a knowledge discovery and decision-making system that has been extensively used in a myriad of applications to assist people in making distinct choices from vast sources. This paper proposes a recommendation system that will help the prospective students of Bangladesh in choosing the most suitable private universities for getting admission. Since selecting the best private university does not depend merely on a few criteria or choices and making a decision considering all those criteria is not an easy task, a recommendation system can be of great assistance in this scenario for the prospective students. In this …


An Oceanographic Perspective On Early Human Migrations To The Americas, Thomas C. Royer, Bruce Finney Jan 2020

An Oceanographic Perspective On Early Human Migrations To The Americas, Thomas C. Royer, Bruce Finney

OES Faculty Publications

Early migrants to the Americas were likely seaworthy. Many archaeologists now agree that the first humans who traveled to the Americas more than 15,000 years before present (yr BP) used a coastal North Pacific route. Their initial migration was from northeastern Asia to Beringia where they settled for thousands to more than ten thousand years. Oceanographic conditions during the Last Glacial Maximum (18,000-24,000 yr BP) would have enhanced their boat journeys along the route from Beringia to the Pacific Northwest because the influx of freshwater that drives the opposing Alaska Coastal Current was small, global sea level was at least …


A Random Subspace Based Conic Functions Ensemble Classifier, Emre Çi̇men Jan 2020

A Random Subspace Based Conic Functions Ensemble Classifier, Emre Çi̇men

Turkish Journal of Electrical Engineering and Computer Sciences

Classifiers overfit when the data dimensionality ratio to the number of samples is high in a dataset. This problem makes a classification model unreliable. When the overfitting problem occurs, one can achieve high accuracy in the training; however, test accuracy occurs significantly less than training accuracy. The random subspace method is a practical approach to overcome the overfitting problem. In random subspace methods, the classification algorithm selects a random subset of the features and trains a classifier function trained with the selected features. The classification algorithm repeats the process multiple times, and eventually obtains an ensemble of classifier functions. Conic …


Quantifying Seagrass Distribution In Coastal Water With Deep Learning Models, Daniel Perez, Kazi Islam, Victoria Hill, Richard Zimmerman, Blake Schaeffer, Yuzhong Shen, Jiang Li Jan 2020

Quantifying Seagrass Distribution In Coastal Water With Deep Learning Models, Daniel Perez, Kazi Islam, Victoria Hill, Richard Zimmerman, Blake Schaeffer, Yuzhong Shen, Jiang Li

OES Faculty Publications

Coastal ecosystems are critically affected by seagrass, both economically and ecologically. However, reliable seagrass distribution information is lacking in nearly all parts of the world because of the excessive costs associated with its assessment. In this paper, we develop two deep learning models for automatic seagrass distribution quantification based on 8-band satellite imagery. Specifically, we implemented a deep capsule network (DCN) and a deep convolutional neural network (CNN) to assess seagrass distribution through regression. The DCN model first determines whether seagrass is presented in the image through classification. Second, if seagrass is presented in the image, it quantifies the seagrass …


A 88 $\Mu W$ Digital Phase-Domain Gfsk Demodulator Compatible With Low-If And Zero-If Receiver With Preamble Detection For Ble, Shen Jie Ung, Ab Al-Hadi Ab Rahman Jan 2020

A 88 $\Mu W$ Digital Phase-Domain Gfsk Demodulator Compatible With Low-If And Zero-If Receiver With Preamble Detection For Ble, Shen Jie Ung, Ab Al-Hadi Ab Rahman

Turkish Journal of Electrical Engineering and Computer Sciences

Unlike conventional analog-to-digital converter (ADC), phase-domain ADC (Ph-ADC) is more power efficient for the implementation of fully digital Gaussian frequency shift keying (GFSK) demodulator in bluetooth low energy (BLE). Besides, Ph-ADC based demodulator is flexible to pair with low-IF and zero-IF receiver, opposed to limiter based demodulator that work with low-IF receiver only. Yet, currently reported Ph-ADC based demodulator lack of preamble detection for BLE which will be used as symbol clock synchronization. In this work, a Ph-ADC based demodulator is proposed with the feature of preamble detection on BLE's packet. The detected preamble is used for symbol clock recovery …


Bibsqlqc: Brown Infomax Boosted Sql Query Clustering Algorithm To Detectanti-Patterns In The Query Log, Vinothsaravanan Ramakrishnan, Palanisamy Chenniappan Jan 2020

Bibsqlqc: Brown Infomax Boosted Sql Query Clustering Algorithm To Detectanti-Patterns In The Query Log, Vinothsaravanan Ramakrishnan, Palanisamy Chenniappan

Turkish Journal of Electrical Engineering and Computer Sciences

Discovery of antipatterns from arbitrary SQL query log depends on the static code analysis used to enhance the quality and performance of software applications. The existence of antipatterns reduces the quality and leads to redundant SQL statements. SQL log includes a large load on the database and it is difficult for an analyst to extract large patterns in a minimal time. Existing techniques which discover antipatterns in SQL query face a lot of innumerable challenges to discover the normal sequences of queries within the log. In order to discover the antipatterns in the log, an efficient technique called Brown infomax …


Towards Sustained Monitoring Of Subsidence At The Coast Using Insar And Gps: An Application In Hampton Roads, Virginia, Brett Buzzanga, David P.S. Bekaert, Ben D. Hamlington, Simran S. Sangha Jan 2020

Towards Sustained Monitoring Of Subsidence At The Coast Using Insar And Gps: An Application In Hampton Roads, Virginia, Brett Buzzanga, David P.S. Bekaert, Ben D. Hamlington, Simran S. Sangha

OES Faculty Publications

Hampton Roads is among the regions along the U.S. Atlantic Coast experiencing high rates of relative sea level rise. Partly to mitigate subsidence from aquifer compaction, Hampton Roads is injecting treated wastewater into the underlying aquifer. However, the GPS (Global Positioning System) station spacing (∼30 km) is too coarse to capture the spatial variability of subsidence and potential uplift from the injection. We present a cost‐effective workflow for generating an InSAR (interferometric synthetic aperture radar) and GPS combined displacement product. We leverage a live, open‐access archive of InSAR products generated from Sentinel‐1 data. We find an overall subsidence rate of …


Disturbance Observer Based Control Of Twin Rotor Aerodynamic System, Hamid Ali, Ahsan Ali, Inam Ul-Hasan Shaikh Jan 2020

Disturbance Observer Based Control Of Twin Rotor Aerodynamic System, Hamid Ali, Ahsan Ali, Inam Ul-Hasan Shaikh

Turkish Journal of Electrical Engineering and Computer Sciences

Twin rotor aerodynamic system (TRAS) approximates the dynamics of helicopters and other vertical take off rotor crafts. The nonlinear nature with significant cross-coupling between the inputs and outputs of the main and tail rotors make the control of such system for either stabilization or reference tracking a challenging task. In this paper, the problem of disturbance rejection for TRAS is addressed by designing disturbance observers through $H_{\infty}$ based approach. The system is decoupled into main and tail rotors subsystems. For each subsystem, an inner loop disturbance observer is synthesized that provides disturbance rejection, whereas to ensure stability and performance an …


Bacterial Biofilms Colonizing Plastics In Estuarine Waters, With An Emphasis On Vibrio Spp. And Their Antibacterial Resistance, Amanda L. Laverty, Sebastian Primke, Claudia Lorenz, Gunnar Gerdtz, Fred Dobbs Jan 2020

Bacterial Biofilms Colonizing Plastics In Estuarine Waters, With An Emphasis On Vibrio Spp. And Their Antibacterial Resistance, Amanda L. Laverty, Sebastian Primke, Claudia Lorenz, Gunnar Gerdtz, Fred Dobbs

OES Faculty Publications

Since plastics degrade very slowly, they remain in the environment on much longer timescales than most natural organic substrates and provide a novel habitat for colonization by bacterial communities. The spectrum of relationships between plastics and bacteria, however, is little understood. The first objective of this study was to examine plastics as substrates for communities of Bacteria in estuarine surface waters. We used next-generation sequencing of the 16S rRNA gene to characterize communities from plastics collected in the field, and over the course of two colonization experiments, from biofilms that developed on plastic (low-density polyethylene, high-density polyethylene, polypropylene, polycarbonate, polystyrene) …


Net-Lda: A Novel Topic Modeling Method Based On Semantic Document Similarity, Eki̇n Eki̇nci̇, Sevi̇nç İlhan Omurca Jan 2020

Net-Lda: A Novel Topic Modeling Method Based On Semantic Document Similarity, Eki̇n Eki̇nci̇, Sevi̇nç İlhan Omurca

Turkish Journal of Electrical Engineering and Computer Sciences

Topic models, such as latent Dirichlet allocation (LDA), allow us to categorize each document based on the topics. It builds a document as a mixture of topics and a topic is modeled as a probability distribution over words. However, the key drawback of the traditional topic model is that it cannot handle the semantic knowledge hidden in the documents. Therefore, semantically related, coherent and meaningful topics cannot be obtained. However, semantic inference plays a significant role in topic modeling as well as in other text mining tasks. In this paper, in order to tackle this problem, a novel NET-LDA model …


Modelling Silicate - Nitrate - Ammonium Co-Limitation Of Algal Growth And The Importance Of Bacterial Remineralisation Based On An Experimental Arctic Coastal Spring Bloom Culture Study, Tobias R. Vonnahme, Martial Leroy, Silke Thoms, Dick Van Oevelen, H. Rodger Harvey, Svein Kristiansen, Rolf Gradinger, Christoph Voelker Jan 2020

Modelling Silicate - Nitrate - Ammonium Co-Limitation Of Algal Growth And The Importance Of Bacterial Remineralisation Based On An Experimental Arctic Coastal Spring Bloom Culture Study, Tobias R. Vonnahme, Martial Leroy, Silke Thoms, Dick Van Oevelen, H. Rodger Harvey, Svein Kristiansen, Rolf Gradinger, Christoph Voelker

OES Faculty Publications

Arctic coastal ecosystems are rapidly changing due to climate warming, which makes modelling their productivity crucially important to better understand future changes. System primary production in these systems is highest during the pronounced spring bloom, typically dominated by diatoms. Eventually the spring blooms terminate due to silicon or nitrogen limitation. Bacteria can play an important role for extending bloom duration and total CO2 fixation through ammonium regeneration. Current ecosystem models often simplify the effects of nutrient co-limitations on algal physiology and cellular ratios and neglect bacterial driven regeneration, leading to an underestimation of primary production. Detailed biochemistry- and cell-based models …


A Secure And Energy-Efficient Opportunistic Routing Protocol With Void Avoidancefor Underwater Acoustic Sensor Networks, Varun Menon, Divya Midhunchakkaravarthy, Sonali John, Sunil Jacob, Amrit Mukherjee Jan 2020

A Secure And Energy-Efficient Opportunistic Routing Protocol With Void Avoidancefor Underwater Acoustic Sensor Networks, Varun Menon, Divya Midhunchakkaravarthy, Sonali John, Sunil Jacob, Amrit Mukherjee

Turkish Journal of Electrical Engineering and Computer Sciences

Recently, underwater acoustic sensor networks (UASNs) have gained wide attention due to their numerous applications in underwater surveillance, oil leakage detection, assisted navigation, and disaster prevention. With unique characteristics like increased propagation delay, constant mobility of sensor nodes, high error rate, and limitations in energy and interference, efficient routing of data packets from the source node to the destination is a major challenge in UASNs. Most of the protocols proposed for traditional sensor networks do not work well in UASNs. Although many protocols have been specifically proposed for underwater environments, the aim of most of them is to improve only …


On A Yearly Basis Prediction Of Soil Water Content Utilizing Sar Data: A Machinelearning And Feature Selection Approach, Emrullah Acar, Mehmet Si̇raç Özerdem Jan 2020

On A Yearly Basis Prediction Of Soil Water Content Utilizing Sar Data: A Machinelearning And Feature Selection Approach, Emrullah Acar, Mehmet Si̇raç Özerdem

Turkish Journal of Electrical Engineering and Computer Sciences

Soil water content (SWC) performs an important role in many areas including agriculture, drought cases, usage of water resources, hydrology, crop diseases and aerology. However, the measurement of the SWC over large terrains with standard computational techniques is very hard. In order to overcome this situation, remote sensing tools are preferred, which can produce much more successful results in less time than standard calculation techniques. Among all remote sensing tools, synthetic aperture radar (SAR) has a significant impact on determining SWC over large terrains. The main objective of this study is to predict SWC on a yearly basis over the …


The Impact Of Eddies On Nutrient Supply, Diatom Biomass And Carbon Export In The Northern South China Sea, Yung-Yen Shih, Chin-Chang Hung, Sing-How Tuo, Huan-Jie Shao, Chun Hoe Chow, Francois L.L. Muller, Yuan-Hong Cai Jan 2020

The Impact Of Eddies On Nutrient Supply, Diatom Biomass And Carbon Export In The Northern South China Sea, Yung-Yen Shih, Chin-Chang Hung, Sing-How Tuo, Huan-Jie Shao, Chun Hoe Chow, Francois L.L. Muller, Yuan-Hong Cai

OES Faculty Publications

We have investigated the effect of eddies (cold and warm eddies, CEs and WEs) on the nutrient supply to the euphotic zone and the organic carbon export from the euphotic zone to deeper parts of the water column in the northern South China Sea. Besides basic hydrographic and biogeochemical parameters, the flux of particulate organic carbon (POC), a critical index of the strength of the oceanic biological pump, was also measured at several locations within two CEs and one WE using floating sediment traps deployed below the euphotic zone. The POC flux associated with the CEs (85 ± 55 mg-C …


Partial Discharge Detection And Localization On The Medium Voltage Xlpe Cableswith Multiclass Support Vector Machines, Fati̇h Serttaş, Fati̇h Onur Hocaoğlu Jan 2020

Partial Discharge Detection And Localization On The Medium Voltage Xlpe Cableswith Multiclass Support Vector Machines, Fati̇h Serttaş, Fati̇h Onur Hocaoğlu

Turkish Journal of Electrical Engineering and Computer Sciences

In medium voltage cables, partial discharges (PD?s) are the major problems that trigger electrical insulation failures. Therefore, classification of PD source type and failure localization in medium voltage cables are significant issues of medium voltage engineering. Therefore, in this study, both detection and localization of PD are studied. As a first step, 4 different kind of defects are artificially generated at the same length of the same kind of medium voltage cross-linked polyethylene (XLPE) cables. Consequently, an experimental setup is built. During the experiments, different medium voltage levels are applied to the cables, then the PD signals are measured and …


Optimal Svc Allocation In Power Systems Using Lightning Attachment Procedureoptimization, Ayman Awad, Salah Kamel, Heba Youssef, Francisco Jurado Jan 2020

Optimal Svc Allocation In Power Systems Using Lightning Attachment Procedureoptimization, Ayman Awad, Salah Kamel, Heba Youssef, Francisco Jurado

Turkish Journal of Electrical Engineering and Computer Sciences

Flexible AC transmission systems (FACTS) technology is widely adopted and utilized to maintain the performance of power systems. However, the improvements of power system performance achieved by FACTS devices depend on the right sizing and allocation of such devices. For technical and economic considerations, a FACTS device's location and size should be selected very carefully in order to maximize its benefits to the power system. In this paper, the sizing and location of a static VAR compensator (SVC) are optimally determined using a new optimization technique called lightning attachment procedure optimization (LAPO). The optimal allocation of the SVC is determined …


Performance Across Worldview-2 And Rapideye For Reproducible Seagrass Mapping, Megan M. Coffer, Blake A. Schaeffer, Richard C. Zimmerman, Victoria Hill, Jiang Li, Kazi A. Islam, Peter J. Whitman Jan 2020

Performance Across Worldview-2 And Rapideye For Reproducible Seagrass Mapping, Megan M. Coffer, Blake A. Schaeffer, Richard C. Zimmerman, Victoria Hill, Jiang Li, Kazi A. Islam, Peter J. Whitman

OES Faculty Publications

Satellite remote sensing offers an effective remedy to challenges in ground-based and aerial mapping that have previously impeded quantitative assessments of global seagrass extent. Commercial satellite platforms offer fine spatial resolution, an important consideration in patchy seagrass ecosystems. Currently, no consistent protocol exists for image processing of commercial data, limiting reproducibility and comparison across space and time. Additionally, the radiometric performance of commercial satellite sensors has not been assessed against the dark and variable targets characteristic of coastal waters. This study compared data products derived from two commercial satellites: DigitalGlobe's WorldView-2 and Planet's RapidEye. A single scene from each platform …


Field-Of-View Optimization Of Magnetically Actuated 2d Gimballed Scanners, Gökçe Aköz, Yi̇ği̇t Dağhan Gökdel Jan 2020

Field-Of-View Optimization Of Magnetically Actuated 2d Gimballed Scanners, Gökçe Aköz, Yi̇ği̇t Dağhan Gökdel

Turkish Journal of Electrical Engineering and Computer Sciences

This work presents the field of view (FOV) maximization of a magnetically actuated two-dimensional (2D) gimballed scanner. The process of maximization is completed in two steps. (1) Optimization of the electrocoil providing the magnetic force that moves the scanner and (2) precise choice of optimum respective locations of both the scanner and the electrocoil. We first derived a formula relating the generated magnetic flux density, coil design parameters and driving voltage. Subsequently, we discussed the design trade-offs of an actuating electrocoil. We also conducted several experiments on a stainless steel 430 scanner having a footprint of 15 mm × 15 …


Exploring The Power Of Supervised Learning Methods For Company Name Disambiguation In Microblog Posts, Nafi̇ye Polat, Ali̇ Çakmak, Rabi̇a Turan Jan 2020

Exploring The Power Of Supervised Learning Methods For Company Name Disambiguation In Microblog Posts, Nafi̇ye Polat, Ali̇ Çakmak, Rabi̇a Turan

Turkish Journal of Electrical Engineering and Computer Sciences

Twitter is an online social networking website where people can post short messages on any subject, and these messages become visible to other users. Users intentionally express their opinions about companies or products via microblogging texts. Analyzing such messages might help explore what customers think about company products, or what the broad feelings of customers are. Identifying tweets referring to products and companies is becoming an important tool recently. However, company names are often vague. Hence, the first step is to locate the messages that are relevant to a company. In this paper, we present a number of supervised learning …


Low Power And Low Phase Noise Vco With Dual Current Shaping For Iotapplications, Sajad Nejadhasan, Narges Moazenian, Ebrahim Abiri, Mohammah Reza Salehi Jan 2020

Low Power And Low Phase Noise Vco With Dual Current Shaping For Iotapplications, Sajad Nejadhasan, Narges Moazenian, Ebrahim Abiri, Mohammah Reza Salehi

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, two low phase noise and power consumption VCO circuits, which are suitable for Internet of things (IoT) applications, are proposed. In the first structure, in order to have more control of the current consumption, the current shaping technique is used in the PMOS and NMOS biasing circuit. In the second structure, for increasing the oscillation amplitude and reducing the phase noise, independent biasing for the NMOS section is used. In both structures, to increase the frequency tuning range (FTR), without using a capacitor bank, the varactor is used in the biasing structure. In the first structure the …


Prominent Quality Attributes Of Crisis Software Systems: A Literature Review, Ahmet Ari̇f Aydin Jan 2020

Prominent Quality Attributes Of Crisis Software Systems: A Literature Review, Ahmet Ari̇f Aydin

Turkish Journal of Electrical Engineering and Computer Sciences

Developing software systems to meet user-demanded functionality is critical. Achieving the design goals by providing the needed functionality is a necessary task, and it is about figuring out a proper set of quality attributes and implementing each one by reflecting a complete set of quality attributes. This study presents popular quality attributes of crisis software systems by conducting a literature review. Each crisis software system has been studied by concentrating on crisis management phases where the system is used, design purposes, and the data processing style. The findings of this research shed light on the crisis software development process by …


Efficient Bandwidth Management Algorithm For Ng-Epon, Ammar Rafiq, Muhammad Faisal Hayat Jan 2020

Efficient Bandwidth Management Algorithm For Ng-Epon, Ammar Rafiq, Muhammad Faisal Hayat

Turkish Journal of Electrical Engineering and Computer Sciences

Next generation ethernet passive optical network (NG-EPON) is a promising technology to cater huge bandwidth and efficient distribution demands of the future Internet services. IEEE working group has been doing efforts for the standardization of NG-EPON. Four wavelength channels of 25Gbps each are supported by NG-EPON for the transmission of optical network unit (ONU) traffic towards optical line terminal (OLT). Dynamic wavelength and bandwidth allocation (DWBA) algorithms are needed for the efficient arbitration of bandwidth resources between subscribers. In this paper, we have proposed a DWBA algorithm named as efficient bandwidth management algorithm (EBMA) for NG-EPON. EBMA has been designed …


Harmonic Effects Optimization At A System Level Using A Harmonic Power Flowcontroller, Reza Mehri, Hossein Mokhtari Jan 2020

Harmonic Effects Optimization At A System Level Using A Harmonic Power Flowcontroller, Reza Mehri, Hossein Mokhtari

Turkish Journal of Electrical Engineering and Computer Sciences

Increase of nonlinear loads in industries has resulted in high levels of harmonic currents and consequently harmonic voltages in power networks. Harmonics have several negative effects such as higher energy losses and equipment life reduction. To reduce the levels of harmonics in power networks, different methods of harmonic suppression have been employed. The basic idea in all of these methods is to prevent harmonics from flowing into a power network at customer sides and the point of common coupling (PCC). Due to the costs, none of the existing mitigating methods result in a harmonic-free power system. The remaining harmonic currents, …


Construction And Performance Analysis Of A New Sac-Ocdma Code Based Onlatin Square Matrix, Amel Aissaoui, Latifa Hacini Jan 2020

Construction And Performance Analysis Of A New Sac-Ocdma Code Based Onlatin Square Matrix, Amel Aissaoui, Latifa Hacini

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper a family of novel spreading code called Latin square code (LSC) is proposed for spectral amplitude coding-optical code division multiple access (SAC-OCDMA) system. The main feature of the proposed code is the zero cross-correlation which eliminates both multiple access interference (MAI) and phase induced intensity noise (PIIN). The code construction can be easily accomplished using Latin square matrix (LSM) for any weight and number of users. The simplicity in the construction code has made it a compelling candidate for future OCDMA applications. SAC-OCDMA system employing direct decoding is mathematically analyzed and then numerically simulated using Matlab and …


Modelling Sensor Ontology With The Sosa/Ssn Frameworks:A Case Study For Laboratory Parameters, Özlem Aktaş, Mehmet Mi̇lli̇, Sanaz Lakestani̇, Musa Mi̇lli̇ Jan 2020

Modelling Sensor Ontology With The Sosa/Ssn Frameworks:A Case Study For Laboratory Parameters, Özlem Aktaş, Mehmet Mi̇lli̇, Sanaz Lakestani̇, Musa Mi̇lli̇

Turkish Journal of Electrical Engineering and Computer Sciences

Recently, the use of sensor-based systems in many areas has led to an exponential increase in the raw sensor data. However, the lack of neither syntactic nor semantic integrity between these sensor data limited their sharing, reusability, and interpretation. These inabilities can cause some problems. For example, different wireless sensor networks may not work together due to the subtle variations in their sensing methods, operating systems, syntax, and data structure. In recent years, to cope with these inabilities, the semantic sensor web approach, which enables us to enrich the meaning of sensor data, has been seen as the critical technology …