13949 research outputs found
Sort by
A Survey about Latest Trends and Research Issues in Cryptographic Elements
No full textProgression in computing powers and parallelism technology are creating obstruction for credible security especially in electronic information swapping under cryptosystems. An enormous set of cryptographic schemes persist in which each has its own affirmative and feeble characteristics. Some schemes carry the use of long bits key and some support the use of small key. Practical cryptosystems are either symmetric or asymmetric in nature. In this painstaking gaze, the accurate selection of right encryption scheme matters for desired information swap to meet enhanced security objectives. This survey compares trendy encryption techniques for convinced selection of both key and cryptographic scheme. In addition, this study introduces two new encryption selection constrains (section 4.1) which are neglected in previous studies. Finally this comprehensive survey thrash outs the latest trends and research issues upon cryptographic elements to conclude forthcoming necessities related to cryptographic key, algorithm structure and enhanced privacy especially in transferring the multimedia information
Performance Analysis of 5A’s Web Robots
No full textHuman nature is greedy to follow less effort heuristics in seeking of scientific literature. Despite of manual literature investigation, web robots are vital tools that provide vision to gigantic passageway of WWW knowledge for information seekers. The reputation and implication of web robots need not be introduced further. Optimal searching approach requires efficient response and reliable services with limited time to quest large array of worldwide information. The list of search engines is too vast with varying index size and performance characteristics. This study evaluates performance metrics like (1) response time, (2) load, (3) page download time, (4) health status, (5) down time, (6) uptime and (7) reliability for popular search engines (AOL, Ask, AltaVista, Alltheweb, Aliweb) starting with initial alphabetic ‘A’ so called 5A’s Web Robots. These 5A’s crawlers have not been evaluated with such technical characteristics before. This paper evaluates selected web robots under practical estimation of technical factors with maximum capacity of seven effective performance metrics. We used two web bench marking tools (Mange Engine Application Manager and Web Application Testing WAPT 6.0) under Active probing techniques to obtain experimental results as this approach has active literature support. Finally, this study concludes new and beneficial results for researcher
Secure Chaotic Map Based Block Cryptosystem with Application to Camera Sensor Networks
No full textRecently, Wang et al. presented an efficient logistic map based block encryption system. The encryption system Employs feedback ciphertext to achieve plaintext dependence of sub-keys. Unfortunately, we discovered that their scheme is unable to withstand key stream attack. To improve its security, this paper proposes a novel chaotic map based block cryptosystem. At the same time, a secure architecture for camera sensor network is constructed. The network comprises a set of inexpensive camera sensors to capture the images, a sink node equipped with sufficient computation and storage capabilities and a data processing server. The transmission security between the sink node and the server is gained by utilizing the improved cipher.
Both theoretical analysis and simulation results indicate that the improved algorithm can overcome the flaws and maintain all the merits of the original cryptosystem. In addition, computational costs and efficiency of the proposed scheme are encouraging for the practical implementation in the real environment as well as camera sensor network
Integrated Control Channel Mechanism for Efficient Channel Utilization in TDMA for WLAN Networks
No full textIn this paper we introduced a custom TDMA MAC Layer Protocol. The main idea which actuated the research was to simulate a complex MAC Protocol in a wireless environment and espy its behavior under different physical, traffic, and network configurations. The TDMA protocol itself is completely custom and not based on any one particular industry specification. Our approach is ideal for exchanging data and control information in Mobile Ad hoc Networks (MANET) and wireless mesh networks so that resource needs (in terms of slot availability) of participating nodes can be rapidly accommodated for Quality of Service (QoS) guarantees. The approach described in this paper allow an efficient resource allocation strategy such that each participating node can converge to a consistent TDMA control slot usage that is optimum for the topology and resource demand of a dynamic wireless network environment and then we further proceeded with capacity planning for such networks based on the optimum control slot usage
A Model-Based Approach for Outlier Detection in Sensor Networks
No full textIn this paper, we propose a model-based approach to detect outliers in sensor networks by exploring the spatial correlation among neighboring nodes. This research is motivated by the observation that sensors in close proximity normally present similar readings.We propose to employ Gaussian mixture modeling as a statistical means to build a probability density function for multivariate spatial neighborhood sensor readings. Outlying sensors can be reliably detected since they exhibit extremely low density values. Our extensive simulation evaluation validates the proposed model-based approach for outlier detection in sensor networks
Direct Algorithms for Finding Minimal Unsatisfiable Subsets in Over-constrained CSPs
No full textIn many situations, an explanation of the reasons behind inconsistency in an overconstrained CSP is required. This explanation can be given in terms of minimal unsatisfiable subsets (MUSes) of constraints. This paper presents algorithms for finding minimal unsatisfiable subsets (MUSes) of constraints in overconstrained CSPs with finite domains and binary constraints. The approach followed is to generate subsets in the subset space, test them for consistency and record the inconsistent subsets found. We present three algorithms as variations of this basic approach. Each algorithm generates subsets in the subset space in a different order and curtails search by employing various search pruning mechanisms. The proposed algorithms are anytime algorithms: a time limit can be set on an algorithm's search and the algorithm can be made to find a subset of MUSes. Experimental evaluation of the proposed algorithms demonstrates that they perform two to three orders of magnitude better than the existing indirect algorithms. Furthermore, the algorithms are able to find MUSes in large CSP benchmarks
Ordered Data and Inference Based on Order Statistics from the Generalized Pareto Distribution and Application
No full textwe derive exact explicit expressions for the single, double, triple, and quadruple moments of order statistics from the generalized Pareto distribution (GPD). Also, we obtain the best linear unbiased estimates of the location and scale parameters (BLUE’s) of the GPD. We then use these results to determine the mean, variance, and coefficients of skewness and kurtosis of certain linear functions of order statistics. These are then utilized to develop approximate confidence intervals for the generalized Pareto parameters using Edgeworth approximation and compare them with those based on Monte Carlo simulations. To show the usefulness of our results, we also present a numerical example. Finally, we give an application to real data
In this paper we prove the existence of constant mean curvature hypersur- faces which are cylindrically bounded and which bifurcate from the family of constant mean curvature hypersurfaces of revolution
No full textIn this paper, we study the set of complete noncompact hypersurfaces which have constant mean curvature equal to 1 and a finite number of ends. By means of the application of the implicit function theorem, we will prove that his set has a smooth structure near any nondegenerate element. We start by a
review of the functional properties of elliptic operators acting on functions defined on a manifold with cylindrical ends. This will explain the central role played by he indicial roots about an n-Delaunay hypersurface. Then, we will explain how to apply the implicit function theorem in our setting. We partially generalize, in any dimension, the results of R. Kusner, R. Mazzeo and D. Pollac
معالم تربوية في قصار المفصل
No full textيتناول أهم المعالم التربوية في سور قصار المفصل (من الضحى إلى الناس
Local Study of Constant Scalar Curvature of Two-dimensional Surfaces Obtained by the Motion of Circle
No full textIn this paper we consider the equiform motion of a circle by studying the scalar curvature for the corresponding two-dimensional surface. We prove that if the scalar curvature K is constant, then K = 0. We describe the equations that
govern such surfaces