Open AccessArticle
Array Multipliers for High Throughput in Xilinx FPGAs with 6-Input LUTs
Computers 2016, 5(4), 20; doi:10.3390/computers5040020 -
Abstract
Multiplication is the dominant operation for many applications implemented on field-programmable gate arrays (FPGAs). Although most current FPGA families have embedded hard multipliers, soft multipliers using lookup tables (LUTs) in the logic fabric remain important. This paper presents a novel two-operand addition [...] Read more.
Multiplication is the dominant operation for many applications implemented on field-programmable gate arrays (FPGAs). Although most current FPGA families have embedded hard multipliers, soft multipliers using lookup tables (LUTs) in the logic fabric remain important. This paper presents a novel two-operand addition circuit (patent pending) that combines radix-4 partial-product generation with addition and shows how it can be used to implement two’s-complement array multipliers. The circuit is specific to modern Xilinx FPGAs that are based on a 6-input LUT architecture. Proposed pipelined multipliers use 42%–52% fewer LUTs, and some versions can be clocked up to 23% faster than delay-optimized LogiCORE IP multipliers. This allows 1.72–2.10-times as many multipliers to be implemented in the same logic fabric and potentially offers 1.86–2.58-times the throughput by increasing the clock frequency. Full article
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Open AccessArticle
Fractal Aspects in Classical Parallel Computing
Computers 2016, 5(3), 19; doi:10.3390/computers5030019 -
Abstract
In this paper, we prove that many parallel communication topologies and several parallel algorithms have fractal properties, which leads to the idea that there is a strong connection between the classical parallel computing and a plausible computing on a fractal medium. Furthermore, [...] Read more.
In this paper, we prove that many parallel communication topologies and several parallel algorithms have fractal properties, which leads to the idea that there is a strong connection between the classical parallel computing and a plausible computing on a fractal medium. Furthermore, we show that some parallel algorithms are suitable for incursive and hyperincursive computation, which links parallel computing to quantum computing and a possible fractal computing. Full article
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Open AccessArticle
A University-Based Smart and Context Aware Solution for People with Disabilities (USCAS-PWD)
Computers 2016, 5(3), 18; doi:10.3390/computers5030018 -
Abstract
(1) Background: A disabled student or employee in a certain university faces a large number of obstacles in achieving his/her ordinary duties. An interactive smart search and communication application can support the people at the university campus and Science Park in a [...] Read more.
(1) Background: A disabled student or employee in a certain university faces a large number of obstacles in achieving his/her ordinary duties. An interactive smart search and communication application can support the people at the university campus and Science Park in a number of ways. Primarily, it can strengthen their professional network and establish a responsive eco-system. Therefore, the objective of this research work is to design and implement a unified flexible and adaptable interface. This interface supports an intensive search and communication tool across the university. It would benefit everybody on campus, especially the People with Disabilities (PWDs). (2) Methods: In this project, three main contributions are presented: (A) Assistive Technology (AT) software design and implementation (based on user- and technology-centered design); (B) A wireless sensor network employed to track and determine user’s location; and (C) A novel event behavior algorithm and movement direction algorithm used to monitor and predict users’ behavior and intervene with them and their caregivers when required. (3) Results: This work has developed a comprehensive and universal application with a unified, flexible, and adaptable interface to support the different conditions of PWDs. It has employed an interactive smart based-location service for establishing a smart university Geographic Information System (GIS) solution. This GIS solution has been based on tracking location service, mobility, and wireless sensor network technologies. (4) Conclusion: The proposed system empowered inter-disciplinary interaction between management, staff, researchers, and students, including the PWDs. Identifying the needs of the PWDs has led to the determination of the relevant requirements for designing and implementing a unified flexible and adaptable interface suitable for PWDs on the university campus. Full article
Open AccessArticle
Color Reduction in an Authenticate Live 3D Point Cloud Video Streaming System
Computers 2016, 5(3), 17; doi:10.3390/computers5030017 -
Abstract
In this paper, an authenticate live 3D point cloud video streaming system is presented, using a low cost 3D sensor camera, the Microsoft Kinect. The proposed system is implemented on a client-server network infrastructure. The live 3D video is captured from the [...] Read more.
In this paper, an authenticate live 3D point cloud video streaming system is presented, using a low cost 3D sensor camera, the Microsoft Kinect. The proposed system is implemented on a client-server network infrastructure. The live 3D video is captured from the Kinect RGB-D sensor, then a 3D point cloud is generated and processed. Filtering and compression are used to handle the spatial and temporal redundancies. A color histogram based conditional filter is designed to reduce the color information for each frame based on the mean and standard deviation. In addition to the designed filter, a statistical outlier removal filter is used. A certificate-based authentication is used where the client will verify the identity of the server during the handshake process. The processed 3D point cloud video is live streamed over a TCP/IP protocol to the client. The system is evaluated in terms of: compression ratio, total bytes per points, peak signal to noise ratio (PSNR), and Structural Similarity (SSIM) index. The experimental results demonstrate that the proposed video streaming system have a best case with SSIM 0.859, PSNR of 26.6 dB and with average compression ratio of 8.42 while the best average compression ratio case is about 15.43 with PSNR 18.5128 dB of and SSIM 0.7936. Full article
Open AccessArticle
Intelligent Intrusion Detection of Grey Hole and Rushing Attacks in Self-Driving Vehicular Networks
Computers 2016, 5(3), 16; doi:10.3390/computers5030016 -
Abstract
Vehicular ad hoc networks (VANETs) play a vital role in the success of self-driving and semi self-driving vehicles, where they improve safety and comfort. Such vehicles depend heavily on external communication with the surrounding environment via data control and Cooperative Awareness Messages [...] Read more.
Vehicular ad hoc networks (VANETs) play a vital role in the success of self-driving and semi self-driving vehicles, where they improve safety and comfort. Such vehicles depend heavily on external communication with the surrounding environment via data control and Cooperative Awareness Messages (CAMs) exchanges. VANETs are potentially exposed to a number of attacks, such as grey hole, black hole, wormhole and rushing attacks. This work presents an intelligent Intrusion Detection System (IDS) that relies on anomaly detection to protect the external communication system from grey hole and rushing attacks. These attacks aim to disrupt the transmission between vehicles and roadside units. The IDS uses features obtained from a trace file generated in a network simulator and consists of a feed-forward neural network and a support vector machine. Additionally, the paper studies the use of a novel systematic response, employed to protect the vehicle when it encounters malicious behaviour. Our simulations of the proposed detection system show that the proposed schemes possess outstanding detection rates with a reduction in false alarms. This safe mode response system has been evaluated using four performance metrics, namely, received packets, packet delivery ratio, dropped packets and the average end to end delay, under both normal and abnormal conditions. Full article
Open AccessArticle
A New Scalable, Distributed, Fuzzy C-Means Algorithm-Based Mobile Agents Scheme for HPC: SPMD Application
Computers 2016, 5(3), 14; doi:10.3390/computers5030014 -
Abstract
The aim of this paper is to present a mobile agents model for distributed classification of Big Data. The great challenge is to optimize the communication costs between the processing elements (PEs) in the parallel and distributed computational models by the way [...] Read more.
The aim of this paper is to present a mobile agents model for distributed classification of Big Data. The great challenge is to optimize the communication costs between the processing elements (PEs) in the parallel and distributed computational models by the way to ensure the scalability and the efficiency of this method. Additionally, the proposed distributed method integrates a new communication mechanism to ensure HPC (High Performance Computing) of parallel programs as distributed one, by means of cooperative mobile agents team that uses its asynchronous communication ability to achieve that. This mobile agents team implements the distributed method of the Fuzzy C-Means Algorithm (DFCM) and performs the Big Data classification in the distributed system. The paper shows the proposed scheme and its assigned DFCM algorithm and presents some experimental results that illustrate the scalability and the efficiency of this distributed method. Full article
Open AccessArticle
Strong Authentication Scheme Based on Hand Geometry and Smart Card Factors
Computers 2016, 5(3), 15; doi:10.3390/computers5030015 -
Abstract
In 2009, Xu et al. presented a safe, dynamic, id-based on remote user authentication method that has several advantages such as freely chosen passwords and mutual authentication. In this paper, we review the Xu–Zhu–Feng scheme and indicate many shortcomings in their scheme. [...] Read more.
In 2009, Xu et al. presented a safe, dynamic, id-based on remote user authentication method that has several advantages such as freely chosen passwords and mutual authentication. In this paper, we review the Xu–Zhu–Feng scheme and indicate many shortcomings in their scheme. Impersonation attacks and insider attacks could be effective. To overcome these drawbacks, we propose a secure biometric-based remote authentication scheme using biometric characteristics of hand-geometry, which is aimed at withstanding well-known attacks and achieving good performance. Furthermore, our work contains many crucial merits such as mutual authentication, user anonymity, freely chosen passwords, secure password changes, session key agreements, revocation by using personal biometrics, and does not need extra device or software for hand geometry in the login phase. Additionally, our scheme is highly efficient and withstands existing known attacks like password guessing, server impersonation, insider attacks, denial of service (DOS) attacks, replay attacks, and parallel-session attacks. Compared with the other related schemes, our work is powerful both in communications and computation costs. Full article
Open AccessArticle
Prediction of Dermoscopy Patterns for Recognition of both Melanocytic and Non-Melanocytic Skin Lesions
Computers 2016, 5(3), 13; doi:10.3390/computers5030013 -
Abstract
A differentiation between all types of melanocytic and non-melanocytic skin lesions (MnM–SK) is a challenging task for both computer-aided diagnosis (CAD) and dermatologists due to the complex structure of patterns. The dermatologists are widely using pattern analysis as a first step with [...] Read more.
A differentiation between all types of melanocytic and non-melanocytic skin lesions (MnM–SK) is a challenging task for both computer-aided diagnosis (CAD) and dermatologists due to the complex structure of patterns. The dermatologists are widely using pattern analysis as a first step with clinical attributes to recognize all categories of pigmented skin lesions (PSLs). To increase the diagnostic accuracy of CAD systems, a new pattern classification algorithm is proposed to predict skin lesions patterns by integrating the majority voting (MV–SVM) scheme with multi-class support vector machine (SVM). The optimal color and texture features are also extracted from each region-of-interest (ROI) dermoscopy image and then these normalized features are fed into an MV–SVM classifier to recognize seven classes. The overall system is evaluated using a dataset of 350 dermoscopy images (50 ROIs per class). On average, the sensitivity of 94%, specificity of 84%, 93% of accuracy and area under the receiver operating curve (AUC) of 0.94 are achieved by the proposed MnM–SK system compared to state-of-the-art methods. The obtained result indicates that the MnM–SK system is successful for obtaining the high level of diagnostic accuracy. Thus, it can be used as an alternative pattern classification system to differentiate among all types of pigmented skin lesions (PSLs). Full article
Open AccessArticle
Optimization of Nano-Process Deposition Parameters Based on Gravitational Search Algorithm
Computers 2016, 5(2), 12; doi:10.3390/computers5020012 -
Abstract
This research is focusing on the radio frequency (RF) magnetron sputtering process, a physical vapor deposition technique which is widely used in thin film production. This process requires the optimized combination of deposition parameters in order to obtain the desirable thin film. [...] Read more.
This research is focusing on the radio frequency (RF) magnetron sputtering process, a physical vapor deposition technique which is widely used in thin film production. This process requires the optimized combination of deposition parameters in order to obtain the desirable thin film. The conventional method in the optimization of the deposition parameters had been reported to be costly and time consuming due to its trial and error nature. Thus, gravitational search algorithm (GSA) technique had been proposed to solve this nano-process parameters optimization problem. In this research, the optimized parameter combination was expected to produce the desirable electrical and optical properties of the thin film. The performance of GSA in this research was compared with that of Particle Swarm Optimization (PSO), Genetic Algorithm (GA), Artificial Immune System (AIS) and Ant Colony Optimization (ACO). Based on the overall results, the GSA optimized parameter combination had generated the best electrical and an acceptable optical properties of thin film compared to the others. This computational experiment is expected to overcome the problem of having to conduct repetitive laboratory experiments in obtaining the most optimized parameter combination. Based on this initial experiment, the adaptation of GSA into this problem could offer a more efficient and productive way of depositing quality thin film in the fabrication process. Full article
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Open AccessArticle
Continuity-Aware Scheduling Algorithm for Scalable Video Streaming
Computers 2016, 5(2), 11; doi:10.3390/computers5020011 -
Abstract
The consumer demand for retrieving and delivering visual content through consumer electronic devices has increased rapidly in recent years. The quality of video in packet networks is susceptible to certain traffic characteristics: average bandwidth availability, loss, delay and delay variation (jitter). This [...] Read more.
The consumer demand for retrieving and delivering visual content through consumer electronic devices has increased rapidly in recent years. The quality of video in packet networks is susceptible to certain traffic characteristics: average bandwidth availability, loss, delay and delay variation (jitter). This paper presents a scheduling algorithm that modifies the stream of scalable video to combat jitter. The algorithm provides unequal look-ahead by safeguarding the base layer (without the need for overhead) of the scalable video. The results of the experiments show that our scheduling algorithm reduces the number of frames with a violated deadline and significantly improves the continuity of the video stream without compromising the average Y Peek Signal-to-Noise Ratio (PSNR). Full article
Open AccessArticle
Face Liveness Detection Using Dynamic Local Ternary Pattern (DLTP)
Computers 2016, 5(2), 10; doi:10.3390/computers5020010 -
Abstract
Face spoofing is considered to be one of the prominent threats to face recognition systems. However, in order to improve the security measures of such biometric systems against deliberate spoof attacks, liveness detection has received significant recent attention from researchers. For this [...] Read more.
Face spoofing is considered to be one of the prominent threats to face recognition systems. However, in order to improve the security measures of such biometric systems against deliberate spoof attacks, liveness detection has received significant recent attention from researchers. For this purpose, analysis of facial skin texture properties becomes more popular because of its limited resource requirement and lower processing cost. The traditional method of skin analysis for liveness detection was to use Local Binary Pattern (LBP) and its variants. LBP descriptors are effective, but they may exhibit certain limitations in near uniform patterns. Thus, in this paper, we demonstrate the effectiveness of Local Ternary Pattern (LTP) as an alternative to LBP. In addition, we adopted Dynamic Local Ternary Pattern (DLTP), which eliminates the manual threshold setting in LTP by using Weber’s law. The proposed method was tested rigorously on four facial spoof databases: three are public domain databases and the other is the Universiti Putra Malaysia (UPM) face spoof database, which was compiled through this study. The results obtained from the proposed DLTP texture descriptor attained optimum accuracy and clearly outperformed the reported LBP and LTP texture descriptors. Full article
Open AccessArticle
Video over DSL with LDGM Codes for Interactive Applications
Computers 2016, 5(2), 9; doi:10.3390/computers5020009 -
Abstract
Digital Subscriber Line (DSL) network access is subject to error bursts, which, for interactive video, can introduce unacceptable latencies if video packets need to be re-sent. If the video packets are protected against errors with Forward Error Correction (FEC), calculation of the [...] Read more.
Digital Subscriber Line (DSL) network access is subject to error bursts, which, for interactive video, can introduce unacceptable latencies if video packets need to be re-sent. If the video packets are protected against errors with Forward Error Correction (FEC), calculation of the application-layer channel codes themselves may also introduce additional latency. This paper proposes Low-Density Generator Matrix (LDGM) codes rather than other popular codes because they are more suitable for interactive video streaming, not only for their computational simplicity but also for their licensing advantage. The paper demonstrates that a reduction of up to 4 dB in video distortion is achievable with LDGM Application Layer (AL) FEC. In addition, an extension to the LDGM scheme is demonstrated, which works by rearranging the columns of the parity check matrix so as to make it even more resilient to burst errors. Telemedicine and video conferencing are typical target applications. Full article
Open AccessArticle
An Artificial Bee Colony-Based COPE Framework for Wireless Sensor Network
Computers 2016, 5(2), 8; doi:10.3390/computers5020008 -
Abstract
In wireless communication, network coding is one of the intelligent approaches to process the packets before transmitting for efficient information exchange. The goal of this work is to enhance throughput by using the intelligent technique, which may give comparatively better optimization. This [...] Read more.
In wireless communication, network coding is one of the intelligent approaches to process the packets before transmitting for efficient information exchange. The goal of this work is to enhance throughput by using the intelligent technique, which may give comparatively better optimization. This paper introduces a biologically-inspired coding approach called Artificial Bee Colony Network Coding (ABC-NC), a modification in the COPE framework. The existing COPE and its variant are probabilistic approaches, which may not give good results in all of the real-time scenarios. Therefore, it needs some intelligent technique to find better packet combinations at intermediate nodes before forwarding to optimize the energy and maximize the throughput in wireless networks. This paper proposes ABC-NC over the existing COPE framework for the wireless environment. Full article
Open AccessReview
Cognitive Radio for Smart Grid with Security Considerations
Computers 2016, 5(2), 7; doi:10.3390/computers5020007 -
Abstract
In this paper, we investigate how Cognitive Radio as a means of communication can be utilized to serve a smart grid deployment end to end, from a home area network to power generation. We show how Cognitive Radio can be mapped to [...] Read more.
In this paper, we investigate how Cognitive Radio as a means of communication can be utilized to serve a smart grid deployment end to end, from a home area network to power generation. We show how Cognitive Radio can be mapped to integrate the possible different communication networks within a smart grid large scale deployment. In addition, various applications in smart grid are defined and discussed showing how Cognitive Radio can be used to fulfill their communication requirements. Moreover, information security issues pertained to the use of Cognitive Radio in a smart grid environment at different levels and layers are discussed and mitigation techniques are suggested. Finally, the well-known Role-Based Access Control (RBAC) is integrated with the Cognitive Radio part of a smart grid communication network to protect against unauthorized access to customer’s data and to the network at large. Full article
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Open AccessArticle
Induction Motor Parameter Identification Using a Gravitational Search Algorithm
Computers 2016, 5(2), 6; doi:10.3390/computers5020006 -
Abstract
The efficient use of electrical energy is a topic that has attracted attention for its environmental consequences. On the other hand, induction motors represent the main component in most industries. They consume the highest energy percentages in industrial facilities. This energy consumption [...] Read more.
The efficient use of electrical energy is a topic that has attracted attention for its environmental consequences. On the other hand, induction motors represent the main component in most industries. They consume the highest energy percentages in industrial facilities. This energy consumption depends on the operation conditions of the induction motor imposed by its internal parameters. Since the internal parameters of an induction motor are not directly measurable, an identification process must be conducted to obtain them. In the identification process, the parameter estimation is transformed into a multidimensional optimization problem where the internal parameters of the induction motor are considered as decision variables. Under this approach, the complexity of the optimization problem tends to produce multimodal error surfaces for which their cost functions are significantly difficult to minimize. Several algorithms based on evolutionary computation principles have been successfully applied to identify the optimal parameters of induction motors. However, most of them maintain an important limitation: They frequently obtain sub-optimal solutions as a result of an improper equilibrium between exploitation and exploration in their search strategies. This paper presents an algorithm for the optimal parameter identification of induction motors. To determine the parameters, the proposed method uses a recent evolutionary method called the gravitational search algorithm (GSA). Different from most of the existent evolutionary algorithms, the GSA presents a better performance in multimodal problems, avoiding critical flaws such as the premature convergence to sub-optimal solutions. Numerical simulations have been conducted on several models to show the effectiveness of the proposed scheme. Full article
Open AccessArticle
An Efficient Decoder for the Recognition of Event-Related Potentials in High-Density MEG Recordings
Computers 2016, 5(2), 5; doi:10.3390/computers5020005 -
Abstract
Brain–computer interfacing (BCI) is a promising technique for regaining communication and control in severely paralyzed people. Many BCI implementations are based on the recognition of task-specific event-related potentials (ERP) such as P300 responses. However, because of the high signal-to-noise ratio in noninvasive [...] Read more.
Brain–computer interfacing (BCI) is a promising technique for regaining communication and control in severely paralyzed people. Many BCI implementations are based on the recognition of task-specific event-related potentials (ERP) such as P300 responses. However, because of the high signal-to-noise ratio in noninvasive brain recordings, reliable detection of single trial ERPs is challenging. Furthermore, the relevant signal is often heterogeneously distributed over several channels. In this paper, we introduce a new approach for recognizing a sequence of attended events from multi-channel brain recordings. The framework utilizes spatial filtering to reduce both noise and signal space considerably. We introduce different models that can be used to construct the spatial filter and evaluate the approach using magnetoencephalography (MEG) data involving P300 responses, recorded during a BCI experiment. Compared to the accuracy achieved in the BCI experiment performed without spatial filtering, the recognition rate increased significantly to up to 95.3% on average (SD: 5.3%). In combination with the data-driven spatial filter construction we introduce here, our framework represents a powerful method to reliably recognize a sequence of brain potentials from high-density electrophysiological data, which could greatly improve the control of BCIs. Full article
Open AccessArticle
The Accurate Method for Computing the Minimum Distance between a Point and an Elliptical Torus
Computers 2016, 5(1), 4; doi:10.3390/computers5010004 -
Abstract
We present an accurate method to compute the minimum distance between a point and an elliptical torus, which is called the orthogonal projection problem. The basic idea is to transform a geometric problem into finding the unique real solution of a quartic [...] Read more.
We present an accurate method to compute the minimum distance between a point and an elliptical torus, which is called the orthogonal projection problem. The basic idea is to transform a geometric problem into finding the unique real solution of a quartic equation, which is fit for orthogonal projection of a point onto the elliptical torus. Firstly, we discuss the corresponding orthogonal projection of a point onto the elliptical torus for test points at six different spatial positions. Secondly, we discuss the same problem for test points on three special positions, e.g., points on the z-axis, the long axis and the minor axis, respectively. Full article
Open AccessArticle
Learning Dispatching Rules for Scheduling: A Synergistic View Comprising Decision Trees, Tabu Search and Simulation
Computers 2016, 5(1), 3; doi:10.3390/computers5010003 -
Abstract
A promising approach for an effective shop scheduling that synergizes the benefits of the combinatorial optimization, supervised learning and discrete-event simulation is presented. Though dispatching rules are in widely used by shop scheduling practitioners, only ordinary performance rules are known; hence, dynamic [...] Read more.
A promising approach for an effective shop scheduling that synergizes the benefits of the combinatorial optimization, supervised learning and discrete-event simulation is presented. Though dispatching rules are in widely used by shop scheduling practitioners, only ordinary performance rules are known; hence, dynamic generation of dispatching rules is desired to make them more effective in changing shop conditions. Meta-heuristics are able to perform quite well and carry more knowledge of the problem domain, however at the cost of prohibitive computational effort in real-time. The primary purpose of this research lies in an offline extraction of this domain knowledge using decision trees to generate simple if-then rules that subsequently act as dispatching rules for scheduling in an online manner. We used similarity index to identify parametric and structural similarity in problem instances in order to implicitly support the learning algorithm for effective rule generation and quality index for relative ranking of the dispatching decisions. Maximum lateness is used as the scheduling objective in a job shop scheduling environment. Full article
Open AccessEditorial
Acknowledgement to Reviewers of Computers in 2015
Computers 2016, 5(1), 2; doi:10.3390/computers5010002 -
Abstract The editors of Computers would like to express their sincere gratitude to the following reviewers for assessing manuscripts in 2015. [...] Full article
Open AccessLetter
Exponentiated Gradient Exploration for Active Learning
Computers 2016, 5(1), 1; doi:10.3390/computers5010001 -
Abstract
Active learning strategies respond to the costly labeling task in a supervised classification by selecting the most useful unlabeled examples in training a predictive model. Many conventional active learning algorithms focus on refining the decision boundary, rather than exploring new regions that [...] Read more.
Active learning strategies respond to the costly labeling task in a supervised classification by selecting the most useful unlabeled examples in training a predictive model. Many conventional active learning algorithms focus on refining the decision boundary, rather than exploring new regions that can be more informative. In this setting, we propose a sequential algorithm named exponentiated gradient (EG)-active that can improve any active learning algorithm by an optimal random exploration. Experimental results show a statistically-significant and appreciable improvement in the performance of our new approach over the existing active feedback methods. Full article