A Novel Model of Sybil Attack in Cluster-Based Wireless Sensor Networks and Propose a Distributed Algorithm to Defend It

Wireless Personal Communications - Today, Wireless Sensor Networks are widely employed in various applications including military, environment, medical and urban applications. Thus, security...     

Multiloop transportation simplex algorithm

In large-scale transportation problems (TPs), various methods have been developed to obtain an optimal solution. One of the methods is the transportation simplex algorithm (TSA), which obtains an optimal solution for TP. Various heuristic methods have been developed to find an initial basic feasible solution for transportation algorithms. These methods differ in terms of computational cost and finding good initial solution. In TSA, the better the basic feasible solution, the less the number of iterations the algorithm will run. At each step, it uses pivoting operation, where a loop involving the nonbasic variable with the largest cost reduction is determined. Then, it eliminates the entering basic variable. However, for large-scale problems, even the best basic feasible solution may result in high number of iterations. In this paper, we present a novel algorithm called multiloop transportation simplex algorithm which finds multiple independent loops during pivoting operation. This causes larger cost reductions in every iteration. We experimentally show that the average number of iterations and runtime to solve the TP are dramatically reduced.     

A novel circularly polarized cavity backed SIW antenna with capability to change polarization diversity by a reconfigurable polarizer structure

This article examines a substrate integrated waveguide (SIW) cavity‐backed circularly polarized diversity antenna. In the proposed novel antenna, parasitic patch and reconfigurable diodes are used to change polarization diversity from left hand to right hand and vice versa, respectively. In addition to, what makes distinctive proposed antenna in compared with similar works, is ability to change linear polarization from a SIW slot to circularly polarization by a parasitic patch. Chopping off two diagonally opposite corners makes the resonance frequency of the mode along this diagonal to be higher than that for the mode along the unchopped diagonal. By exciting parasitic patch with a slot along axes of it the orthogonal modes are generated which causes to CP. The comparison between simulation and measurement results validate antenna design. The measured impedance BW (VSWR < 2) for state 1 and 2 are 22.18% (11.86‐14.82 GHz) and 21.68% (11.88‐14.77 GHz), and The measured 3‐dB AR BW for states 1 and 2 are about 11.46% (11.43‐12.82 GHz) and 11.23% (11.43‐12.79 GHz), respectively. Finally, the measured maximum gain is 9.81 dBic.     

Spectral Angle Mapper and aeromagnetic data integration for gold-associated alteration zone mapping: a case study for the Central Eastern Desert Egypt

The Spectral Angle Mapper (SAM) classification technique is integrated with the surface structure and aeromagnetic data to map the potential gold mineralization sites associated within alteration zones in Central Eastern Desert (CED), Egypt. The surface reflectances of the Enhanced Thematic Mapper Plus (ETM+) and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data were classified using the SAM classifier. Five spectral reflectance curves of the alteration minerals (haematite, illite, kaolinite, chlorite, and quartz) were utilized as end-members for the SAM classification. The surface lineation, and shear zone systems were delineated using ETM+ bands. The deep-seated faults were defined using the Euler deconvolution filter on the gridded aeromagnetic data. The magnetic data analysis inferred the subsurface structural depths range from 500 m to 2000 m. Geographic information system (GIS) overlaying operation was performed using the surface lineation and the subsurface faults layers to identify the structural continuity and to extract the possible migratory pathways of the hydrothermal solutions. Within Multiple Criteria Decision Analysis (MCDA), fuzzy membership operations were applied to identify the prospective alteration sites. The mapped results were compared with global positioning system (GPS) locations of existing alteration zones. The current proposed mapping method is considered a robust tool for decision-making and potential site selection technique for further mineral exploration in CED.     

“突厥语大词典”电子词典的设计与实现

介绍了11世纪中国突厥语言学著作"突厥语大词典"的电子词典软件的设计与实现。突厥语大辞典的电子版是突厥语大辞典的维、土、汉、英版本的基础上研究了多语种(维吾尔语、土耳其语、汉语、英语)突厥语大辞典电子版的构建技术。实现了具有通过原词或原词在以上四种不同语言中的词义来快速查找的功能。详细介绍了本词典的总体结构、功能、数据库设计、查找算法、系统运行机制。最后提出了进一步增强、改进系统的一些设想。     

Traffic signal timing using two-dimensional correlation,neuro-fuzzy and queuing based neural networks

Optimizing the traffic signal control has an essential impact on intersections efficiency in urban transportation. This paper presents a two-stage method for intersection signal timing control. First, the traffic volume is predicted using a neuro-fuzzy network called Adaptive neuro-fuzzy inference system (ANFIS). The inputs of this network include two-dimensional, hourly and daily, traffic volume correlations. In the second stage, appropriate signal cycle and optimized timing of each phase of the signal are estimated using a combination of Self Organizing and Hopfield neural networks. The energy function of the Hopfield network is based on a traffic model derived by queuing analysis. The performance of the proposed method has been evaluated for real data. The two-dimensional correlation presents superior performance compared to hourly traffic correlation. The evaluation of proposed overall method shows considerable intersection throughput improvement comparing to the results taken form Synchro software.     

A peer-to-peer file search and download protocol for wireless ad-hoc networks

Deployment of traditional peer-to-peer file sharing systems on a wireless ad-hoc network introduces several challenges. Information and workload distribution as well as routing are major problems for members of a wireless ad-hoc network, which are only aware of their immediate neighborhood. In this paper, we propose a file sharing system that is able to answer location queries, and also discover and maintain the routing information that is used to transfer files from a source peer to another peer. We present a cross-layer design, where the lookup and routing functionality are unified. The system works according to peer-to-peer principles, distributes the location information of the shared files among the members of the network. The paper includes a sample scenario to make the operations of the system clearer. The performance of the system is evaluated using simulation results and analysis is provided for comparing our approach with a flooding-based, unstructured approach.     

Natural language watermarking via morphosyntactic alterations

We develop a morphosyntax-based natural language watermarking scheme. In this scheme, a text is first transformed into a syntactic tree diagram where the hierarchies and the functional dependencies are made explicit. The watermarking software then operates on the sentences in syntax tree format and executes binary changes under control of Wordnet and Dictionary to avoid semantic drops. A certain level of security is provided via key-controlled randomization of morphosyntactic tools and the insertion of void watermark. The security aspects and payload aspects are evaluated statistically while the imperceptibility is measured using edit-hit counts based on human judgments. It is observed that agglutinative languages are somewhat more amenable to morphosyntax-based natural language watermarking and the free word order property of a language, like Turkish, is an extra bonus.