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- Classification (10)
- Machine learning (10)
- Support vector machine (8)
- Feature selection (7)
- Genetic algorithm (7)
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- Feature extraction (6)
- Optimization (6)
- Wireless sensor networks (6)
- Particle swarm optimization (5)
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- Fuzzy logic control (3)
- Gravitational search algorithm (3)
- Image processing (3)
- K-means (3)
- Low power (3)
- Sentiment analysis (3)
- Social media (3)
- Social networks (3)
- Voltage stability (3)
- Artificial neural networks (2)
Articles 1 - 30 of 335
Full-Text Articles in Physical Sciences and Mathematics
Sensorless Second-Order Switching Surface For A Three-Level Boost Converter, Tarek Messikh, Nasrudin Abd Rahim, Saad Mekhilef
Sensorless Second-Order Switching Surface For A Three-Level Boost Converter, Tarek Messikh, Nasrudin Abd Rahim, Saad Mekhilef
Turkish Journal of Electrical Engineering and Computer Sciences
This paper proposes a sensorless second-order switching surface to control a three-level boost converter (TLBC). A predictive current method is proposed to reduce the number of sensors in the normal second-order switching surface method. Based on a developed model of the TLBC, the current is estimated and a switching surface is formulated in the state-energy plane. Simulation and hardware tests are carried out to verify the viability and the effectiveness of the proposed control technique. Results obtained show a good performance of the converter in term of DC-bus balancing and fast dynamic response under sudden load change.
Three-Channel Control Architecture For Multilateral Teleoperation Under Time Delay, Uğur Tümerdem
Three-Channel Control Architecture For Multilateral Teleoperation Under Time Delay, Uğur Tümerdem
Turkish Journal of Electrical Engineering and Computer Sciences
Multilateral teleoperation is an extension of bilateral/haptic teleoperation framework to multiple operators/robots and finds applications in haptic training. As in bilateral teleoperation, time delay is an important problem, and stability and transparency, which quantifies the performance of the teleoperation system, are critical in the design of multilateral control systems. This paper proposes a novel three-channel-based multilateral control architecture with damping injection to guarantee delay-independent L2 stability and high transparency in multilateral teleoperation systems. The theoretical and computational analyses are verified with experiment results.
Contribution Of Artificial Proprioception On A Dynamic Finger Flexion Task, Mehdi Hojatmadani, Evren Samur
Contribution Of Artificial Proprioception On A Dynamic Finger Flexion Task, Mehdi Hojatmadani, Evren Samur
Turkish Journal of Electrical Engineering and Computer Sciences
There has been a considerable effort to provide sensory feedback for myoelectric prostheses. Among the solutions provided in the literature, sensory substitution is an easy and cost-effective way to provide feedback through different sensory modalities at different locations on the body. In this study, we evaluate the effect of sensory substitution of force and position feedback on a two-degree-of-freedom dynamic finger flexion task. For this purpose, a new methodology and an experimental setup are developed. The experimental methodology is based on the "strength-dexterity test", working on the principle of buckling of compression springs. The experimental setup comprises a haptic interface, …
Optimized Modeling Of Ni-Mh Batteries Primarily Based On Taguchi Approach And Evaluation Of Used Ni-Mh Batteries, Hani Muhsen, Ahmad Al-Muhtady
Optimized Modeling Of Ni-Mh Batteries Primarily Based On Taguchi Approach And Evaluation Of Used Ni-Mh Batteries, Hani Muhsen, Ahmad Al-Muhtady
Turkish Journal of Electrical Engineering and Computer Sciences
This paper aims to generate an optimized model of the Ni-MH battery based on the Taguchi method and it further aims to evaluate used Ni-MH batteries that served in hybrid electric vehicles and electric vehicles. The status of twelve used Ni-MH batteries is studied to determine their usefulness after their life cycle in automotive applications. The status of used batteries is evaluated by investigating their state of charge, remaining useful life, and degradation in performance. Accordingly, the tested batteries are classified into four categories and they are proposed to serve in different applications. The novelty of the work lies in …
Evaluation Of Power System Robustness In Order To Prevent Cascading Outages, Farnaaz Hajbani, Heresh Seyedi, Kazem Zare
Evaluation Of Power System Robustness In Order To Prevent Cascading Outages, Farnaaz Hajbani, Heresh Seyedi, Kazem Zare
Turkish Journal of Electrical Engineering and Computer Sciences
Power system robustness against overload condition is a challenging issue in the fields of power system planning and operation. In this paper, two indices are proposed to evaluate power system robustness. The proposed indices are used to identify critical lines whose failure is due to overload, leading the power system to cascading outages and blackout. The first proposed index is a linear index. The second index is based on graph theory metrics. To prevent cascading outages, system robustness is calculated for all N-1 and N-2 contingencies. The lines whose outages lead to the smallest robustness values are considered as critical …
Improved Vsm Control Of Pmsg-Based Wind Farms For Transient Stability Enhancement, Mohamed Abbes, Ines Mehouachi, Souad Chebbi
Improved Vsm Control Of Pmsg-Based Wind Farms For Transient Stability Enhancement, Mohamed Abbes, Ines Mehouachi, Souad Chebbi
Turkish Journal of Electrical Engineering and Computer Sciences
This paper analyzes the optimal control strategy of PMSG-based wind farms during faults in order to improve the transient stability of a power system with a high penetration rate of wind power. The investigated control strategies are the unity power factor (UPF), reactive power control (RPC), and particularly the concept of virtual synchronous machine (VSM). The transient stability level is assessed using the critical clearing time index, which was calculated based on trajectory sensitivity analysis. In light of the obtained results, it was found that RPC gives the best transient stability level, followed by the classical VSM control. Hence, an …
Determination Of Distance Between Dc Traction Power Centers In A 1500-V Dc Subway Line With Artificial Intelligence Methods, Mehmet Taci̇ddi̇n Akçay, İlhan Kocaarslan
Determination Of Distance Between Dc Traction Power Centers In A 1500-V Dc Subway Line With Artificial Intelligence Methods, Mehmet Taci̇ddi̇n Akçay, İlhan Kocaarslan
Turkish Journal of Electrical Engineering and Computer Sciences
The electrification system in rail systems is designed with regard to the operating data and design parameters. While the electrification system is formed, the minimum voltage rating that the traction force requires during the operation needs to be provided. The highest value of the voltage drop occurring on the line is determined by the distance between power centers. This value needs to be kept within certain limits for the continuity of operation. In this study, the determination of the distance between DC traction power centers for a 1500-V DC-fed rail system is done by means of the adaptive neuro-fuzzy inference …
A Fuzzy Model Of Directional Relationships From The Phi-Descriptor, Mohammad Naeem, Nasir Ahmad, Sahib Khan, Asma Gul
A Fuzzy Model Of Directional Relationships From The Phi-Descriptor, Mohammad Naeem, Nasir Ahmad, Sahib Khan, Asma Gul
Turkish Journal of Electrical Engineering and Computer Sciences
Directional spatial relationships are a category of spatial relationships and have applications in the fields of image processing, geographic information systems, natural language processing, and robot navigation. They can be directly extracted from images or can be interpreted from a type of image descriptors called the relative position descriptors. Examples of relative position descriptors are the angle histogram, the force histogram, and the recently proposed phi-descriptor. So far, fuzzy models of directional spatial relationships from the angle histogram and force histograms have been proposed in the literature. These include the compatibility method, the aggregation method, and the method of effective …
Heuristic Optimization Techniques For Voltage Stability Enhancement Of Radial Distribution Network With Simultaneous Consideration Of Network Reconfiguration And Dg Sizing And Allocations, Mahiraj Singh Rawat, Shelly Vadhera
Heuristic Optimization Techniques For Voltage Stability Enhancement Of Radial Distribution Network With Simultaneous Consideration Of Network Reconfiguration And Dg Sizing And Allocations, Mahiraj Singh Rawat, Shelly Vadhera
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, heuristic optimization techniques, such as integrated particle swarm optimization (IPSO), teaching--learning-based optimization (TLBO), and Jaya optimization, were applied effectively for the first time to optimize the radial distribution network (RDN) by simultaneously considering reconfiguration of the network and allocation and sizing of the distributed generations (DG). The objectives were to maximize the voltage stability and to minimize the power loss of the network without violating the system constraints. In standard PSO technique, the movement of current particle depends upon global best position and its own best position up to current step. However, if the particle lies too …
Convex Polygon Triangulation Based On Planted Trivalent Binary Tree\\ And Ballot Problem, Muzafer Saracevic, Aybeyan Seli̇mi̇
Convex Polygon Triangulation Based On Planted Trivalent Binary Tree\\ And Ballot Problem, Muzafer Saracevic, Aybeyan Seli̇mi̇
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents a new technique of generation of convex polygon triangulation based on planted trivalent binary tree and ballot notation. The properties of the Catalan numbers were examined and their decomposition and application in developing the hierarchy and triangulation trees were analyzed. The method of storage and processing of triangulation was constructed on the basis of movements through the polygon. This method was derived from vertices and leaves of the planted trivalent binary tree. The research subject of the paper is analysis and comparison of a constructed method for solving of convex polygon triangulation problem with other methods and …
Data Analysis Through Social Media According To The Classified Crime, Serkan Savaş, Nuretti̇n Topaloğlu
Data Analysis Through Social Media According To The Classified Crime, Serkan Savaş, Nuretti̇n Topaloğlu
Turkish Journal of Electrical Engineering and Computer Sciences
The amount and variety of data generated through social media sites has increased along with the widespread use of social media sites. In addition, the data production rate has increased in the same way. The inclusion of personal information within these data makes it important to process the data and reach meaningful information within it. This process can be called intelligence and this meaningful information may be for commercial, academic, or security purposes. An example application is developed in this study for intelligence on Twitter. Crimes in Turkey are classified according to Turkish Statistical Institute criminal data and keywords are …
A Tree-Based Approach For English-To-Turkish Translation, Özge Bakay, Begüm Avar, Olcay Taner Yildiz
A Tree-Based Approach For English-To-Turkish Translation, Özge Bakay, Begüm Avar, Olcay Taner Yildiz
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, we present our English-to-Turkish translation methodology, which adopts a tree-based approach. Our approach relies on tree analysis and the application of structural modification rules to get the target side (Turkish) trees from source side (English) ones. We also use morphological analysis to get candidate root words and apply tree-based rules to obtain the agglutinated target words. Compared to earlier work on English-to-Turkish translation using phrase-based models, we have been able to obtain higher BLEU scores in our current study. Our syntactic subtree permutation strategy, combined with a word replacement algorithm, provides a 67 % relative improvement from …
Improving Anomaly Detection In Bgp Time-Series Data By New Guide Features And Moderated Feature Selection Algorithm, Mahmoud Hashem, Ahmed Bashandy, Samir Shaheen
Improving Anomaly Detection In Bgp Time-Series Data By New Guide Features And Moderated Feature Selection Algorithm, Mahmoud Hashem, Ahmed Bashandy, Samir Shaheen
Turkish Journal of Electrical Engineering and Computer Sciences
The Internet infrastructure relies on the Border Gateway Protocol (BGP) to provide essential routing information where abnormal routing behavior impairs global Internet connectivity and stability. Hence, employing anomaly detection algorithms is important for improving the performance of BGP routing protocol. In this paper, we propose two algorithms; the first is the guide feature generator (GFG), which generates guide features from traditional features in BGP time-series data using moving regression in combination with smoothed moving average. The second is a modified random forest feature selection algorithm which is employed to automatically select the most dominant features (ASMDF). Our mechanism shows that …
Automatic Concept Identification Of Software Requirements In Turkish, Fatma Bozyi̇ği̇t, Özlem Aktaş, Deni̇z Kilinç
Automatic Concept Identification Of Software Requirements In Turkish, Fatma Bozyi̇ği̇t, Özlem Aktaş, Deni̇z Kilinç
Turkish Journal of Electrical Engineering and Computer Sciences
Software requirements include description of the features for the target system and express the expectations of users. In the analysis phase, requirements are transformed into easy-to-understand conceptual models that facilitate communication between stakeholders. Although creating conceptual models using requirements is mostly implemented manually by analysts, the number of models that automate this process has increased recently. Most of the models and tools are developed to analyze requirements in English, and there is no study for agglutinative languages such as Turkish or Finnish. In this study, we propose an automatic concept identification model that transforms Turkish requirements into Unified Modeling Language …
Fuzzy Logic-Based Disparity Selection Using Multiple Data Costs For Stereo Correspondence, Akhil Appu Shetty, V.I George, C Gurudas Nayak, Raviraj Shetty
Fuzzy Logic-Based Disparity Selection Using Multiple Data Costs For Stereo Correspondence, Akhil Appu Shetty, V.I George, C Gurudas Nayak, Raviraj Shetty
Turkish Journal of Electrical Engineering and Computer Sciences
Stereo matching algorithms are capable of generating depth maps from two images of the same scene taken simultaneously from two different viewpoints. Traditionally, a single cost function is used to calculate the disparity between corresponding pixels in the left and right images. In the present research, we have considered a combination of simple data costs. A new method to combine multiple data costs is presented and a fuzzy-based disparity selection method is proposed. Experiments with different combinations of parameters are conducted and compared through the Middlebury and Kitti Stereo Vision Benchmark.
Formally Analyzed M-Coupon Protocol With Confirmation Code (Mcwcc), Keri̇m Yildirim, Gökhan Dalkiliç, Nevci̇han Duru
Formally Analyzed M-Coupon Protocol With Confirmation Code (Mcwcc), Keri̇m Yildirim, Gökhan Dalkiliç, Nevci̇han Duru
Turkish Journal of Electrical Engineering and Computer Sciences
There are many marketing methods used to attract customers' attention and customers search for special discounts and conduct research to get products cheaper. Using discount coupons is one of the widely used methods for obtaining discounts. With the development of technology, classical paper-based discount coupons become e-coupons and then turn into mobile coupons (m-coupons). It is inevitable that retailers will use m-coupon technology to attract customers while mobile devices are used in daily life. As a result, m-coupon technology is a promising technology. One of the significant problems with using m-coupons is security. Here it is necessary to ensure the …
Stegogis: A New Steganography Method Using The Geospatial Domain, Ömer Kurtuldu, Mehmet Demi̇rci̇
Stegogis: A New Steganography Method Using The Geospatial Domain, Ömer Kurtuldu, Mehmet Demi̇rci̇
Turkish Journal of Electrical Engineering and Computer Sciences
Geographic data are used on a variety of computing devices for many different applications including navigation, tracking, location planning, and marketing. The prevalence of geographic data makes it possible to envision new useful applications. In this paper, we propose using geographic data as a medium for secret communication, or steganography. We develop a method called StegoGIS for hiding messages in geographic coordinates in the well-known binary of fast-moving objects and transmitting them secretly. We show that discovering this secret communication is practically impossible for third parties. We also show that a large amount of secret data can be transmitted this …
Accurate And Compact Stochastic Computations By Exploiting Correlation, Hamdan Abdellatef, Mohamed Khalil Hani, Nasir Shaikh-Husin
Accurate And Compact Stochastic Computations By Exploiting Correlation, Hamdan Abdellatef, Mohamed Khalil Hani, Nasir Shaikh-Husin
Turkish Journal of Electrical Engineering and Computer Sciences
Recent studies have shown, contrary to what was previously believed, that by exploiting correlation in stochastic computing (SC) designs, more accurate SC circuits with low area cost can be realized. However, if these basic SC circuits or blocks are cascaded in series to form a large complex system, correlation between stochastic numbers (SNs) from one block to the next would be lost; thus, inaccuracies are introduced. In this study, we propose correlating circuits to be used in building complex correlated SC systems. One of the circuits is the correlator that restores lost correlations between two SNs due to previous processing. …
Motion Blur Image Deblurring Using Edge-Based Color Patches, Xixuan Zhao, Jiangming Kan
Motion Blur Image Deblurring Using Edge-Based Color Patches, Xixuan Zhao, Jiangming Kan
Turkish Journal of Electrical Engineering and Computer Sciences
The shaking of a camera can easily cause blurs in an image. Thus, deblurring is a problem that is worth solving and has always been an active research interest. The color information in an image is an important feature and contains clues for image deblurring that have not been widely exploited. In this paper, we present an efficient and stable blurring kernel estimation method by solving an energy function constructed by a weighted color approximation regularization term. The term is derived from a two-color model, and we use a defined weight to alleviate the color change through the blurring process. …
A Multiseed-Based Svm Classification Technique For Training Sample Reduction, Imran Sharif, Debasis Chaudhuri
A Multiseed-Based Svm Classification Technique For Training Sample Reduction, Imran Sharif, Debasis Chaudhuri
Turkish Journal of Electrical Engineering and Computer Sciences
A support vector machine (SVM) is not a popular method for a very large dataset classification because the training and testing time for such data are computationally expensive. Many researchers try to reduce the training time of SVMs by applying sample reduction methods. Many methods reduced the training samples by using a clustering technique. To reduce its high computational complexity, several data reduction methods were proposed in previous studies. However, such methods are not effective to extract informative patterns. This paper demonstrates a new supervised classification method, multiseed-based SVM (MSB-SVM), which is particularly intended to deal with very large datasets …
Optimal Set Of Eeg Features In Infant Sleep Stage Classification, Maja Cic, Mario Milicevic, Igor Mazic
Optimal Set Of Eeg Features In Infant Sleep Stage Classification, Maja Cic, Mario Milicevic, Igor Mazic
Turkish Journal of Electrical Engineering and Computer Sciences
This paper evaluates six classification algorithms to assess the importance of individual EEG rhythms in the context of automatic classification of infant sleep. EEG features were obtained by Fourier transform and by a novel technique based on the empirical mode decomposition and generalized zero crossing method. Of six evaluated classification algorithms, the best classification results were obtained with the support vector machine for the combination of all presented features from four EEG channels. Three methods of attribute ranking were assessed: relief, principal component analysis, and wrapper-based optimized attribute weights. The outcomes revealed that the optimal selection of features requires one …
On The Stability Of Inverse Dynamics Control Of Flexible-Joint Parallel Manipulators In The Presence Of Modeling Error And Disturbances, Sitki Kemal İder, Ozan Korkmaz, Mustafa Semi̇h Deni̇zli̇
On The Stability Of Inverse Dynamics Control Of Flexible-Joint Parallel Manipulators In The Presence Of Modeling Error And Disturbances, Sitki Kemal İder, Ozan Korkmaz, Mustafa Semi̇h Deni̇zli̇
Turkish Journal of Electrical Engineering and Computer Sciences
Inverse dynamics control is considered for flexible-joint parallel manipulators in order to obtain a good trajectory tracking performance in the case of modeling error and disturbances. It is known that, in the absence of modeling error and disturbance, inverse dynamics control leads to linear fourth-order error dynamics, which is asymptotically stable if the feedback gains are chosen to make the real part of the eigenvalues of the system negative. However, when there are modeling errors and disturbances, a linear time-varying error dynamics is obtained whose stability is not assured only by keeping the real parts of the frozen-time eigenvalues of …
A Coordinated Dc Voltage Control Strategy For Cascaded Solid State Transformer With Star Configuration, Zhendong Ji, Yichao Sun, Cheng Jin, Jianhua Wang, Jianfeng Zhao
A Coordinated Dc Voltage Control Strategy For Cascaded Solid State Transformer With Star Configuration, Zhendong Ji, Yichao Sun, Cheng Jin, Jianhua Wang, Jianfeng Zhao
Turkish Journal of Electrical Engineering and Computer Sciences
Cascaded solid-state transformer (SST) can be directly connected to the high-voltage distribution grid, and it has broad applications in the future smart grid, traction locomotive, and renewable energy integration. However, the reliability of the cascaded SST is seriously influenced by the DC voltage and power imbalance issues with this configuration. This paper presents a coordinated DC voltage control strategy for cascaded SST with star configuration, in which the average DC voltage and the balancing DC voltage are controlled separately without current sensors in dual active bridge (DAB) modules. This strategy not only reduces the cost and the complexity of the …
Synchronization And Antisynchronization Protocol Design Of Chaotic Nonlinear Gyros: An Adaptive Integral Sliding Mode Approach, Fazal Ur Rahman, Qudrat Khan, Rini Akmeliawati
Synchronization And Antisynchronization Protocol Design Of Chaotic Nonlinear Gyros: An Adaptive Integral Sliding Mode Approach, Fazal Ur Rahman, Qudrat Khan, Rini Akmeliawati
Turkish Journal of Electrical Engineering and Computer Sciences
A novel control protocol design, via integral sliding mode control with parameter update laws, for synchronization and desynchronization of a chaotic nonlinear gyro with unknown parameters is the focus of this work. The error dynamics of the actual system are substructured into nominal and uncertain parts to employ adaptive integral sliding mode (AISM) control. The uncertain parameters are estimated via devised adaptive laws. Then the disagreement dynamics are guided to origin via AISM control. The stabilizing controller is also designed in terms of nominal control along with a compensating component. The control and the parameter update laws are constructed to …
Assessment Of Techno-Economic Benefits For Smart Charging Scheme Of Electric Vehicles In Residential Distribution System, Kumari Kasturi, Manas Ranjan Nayak
Assessment Of Techno-Economic Benefits For Smart Charging Scheme Of Electric Vehicles In Residential Distribution System, Kumari Kasturi, Manas Ranjan Nayak
Turkish Journal of Electrical Engineering and Computer Sciences
Connecting multiple electric vehicles (EVs) to a power system network for the purpose of charging has major setbacks like decrease in power quality, instability in voltage profile, and increase in power losses and thus electricity price. This paper focuses on devising an optimal charging scheme to reduce the negative impacts of EVs' presence in the distribution network by limiting the charging process to only off-peak demand periods when the electricity price is comparatively lower. The salp swarm algorithm, an efficient, fast, and reliable optimization technique, is used to obtain the optimal locations for the EVs and their charging schedule in …
Lung Segmentation In Chest Radiographs Using Fully Convolutional Networks, Rahul Hooda, Ajay Mittal, Sanjeev Sofat
Lung Segmentation In Chest Radiographs Using Fully Convolutional Networks, Rahul Hooda, Ajay Mittal, Sanjeev Sofat
Turkish Journal of Electrical Engineering and Computer Sciences
Automated segmentation of medical images that aims at extracting anatomical boundaries is a fundamental step in any computer-aided diagnosis (CAD) system. Chest radiographic CAD systems, which are used to detect pulmonary diseases, first segment the lung field to precisely define the region-of-interest from which radiographic patterns are sought. In this paper, a deep learning-based method for segmenting lung fields from chest radiographs has been proposed. Several modifications in the fully convolutional network, which is used for segmenting natural images to date, have been attempted and evaluated to finally evolve a network fine-tuned for segmenting lung fields. The testing accuracy and …
Approximation Of Planar Curves, Malik Zawwar Hussain, Ayesha Shakeel, Maria Hussain
Approximation Of Planar Curves, Malik Zawwar Hussain, Ayesha Shakeel, Maria Hussain
Turkish Journal of Electrical Engineering and Computer Sciences
In the present article, we have developed the $G^{2}$-approximation scheme for planar curves arising in science, engineering, computer-aided design, computer-aided manufacturing, and many other fields. The obtained results reveal that the proposed method is a significant addition to the approximation of planar curves. The method is illustrated using different numerical examples. The smaller absolute error confirms the applicability and efficiency of the proposed method.
On Spectral Analysis Of The Internet Delay Space And Detecting Anomalous Routing Paths, Gonca Gürsun
On Spectral Analysis Of The Internet Delay Space And Detecting Anomalous Routing Paths, Gonca Gürsun
Turkish Journal of Electrical Engineering and Computer Sciences
Latency is one of the most critical performance metrics for a wide range of applications. Therefore, it is important to understand the underlying mechanisms that give rise to the observed latency values and diagnose the ones that are unexpectedly high. In this paper, we study the Internet delay space via robust principal component analysis (RPCA). Using RPCA, we show that the delay space, i.e. the matrix of measured round trip times between end hosts, can be decomposed into two components: the estimated latency between end hosts with respect to the current state of the Internet and the inflation on the …
Efficient Virtual Data Center Request Embedding Based On Row-Epitaxial And Batched Greedy Algorithms, Sivaranjani B, Surendran Doraiswamy
Efficient Virtual Data Center Request Embedding Based On Row-Epitaxial And Batched Greedy Algorithms, Sivaranjani B, Surendran Doraiswamy
Turkish Journal of Electrical Engineering and Computer Sciences
Data centers are becoming the main backbone of and centralized repository for all cloud-accessible services in on-demand cloud computing environments. In particular, virtual data centers (VDCs) facilitate the virtualization of all data center resources such as computing, memory, storage, and networking equipment as a single unit. It is necessary to use the data center efficiently to improve its profitability. The essential factor that significantly influences efficiency is the average number of VDC requests serviced by the infrastructure provider, and the optimal allocation of requests improves the acceptance rate. In existing VDC request embedding algorithms, data center performance factors such as …
A Novel Adaptive Hysteresis Dc-Dc Buck Converter For Portable Devices, Sung Sik Park, Ju Sang Lee, Sang Dae Yu
A Novel Adaptive Hysteresis Dc-Dc Buck Converter For Portable Devices, Sung Sik Park, Ju Sang Lee, Sang Dae Yu
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents a new technique that adjusts the hysteresis window depending on the variations in load current caused by a voltage-mode circuit to reduce the voltage and current ripples. Moreover, a compact current-sensing circuit is used to provide an accurate sensing signal for achieving fast hysteresis window adjustment. In addition, a zero-current detection circuit is also proposed to eliminate the reverse current at light loads. As a result, this technique reduces the voltage ripple below 8.08 mV$_{\rm pp}$ and the current ripple below 93.98 mA$_{\rm pp}$ for a load current of 500 mA. Circuit simulation is performed using 0.18 …