Topology Control

The issues in Mobil ad-hoc networks (MANETs) always bring the attention of research community. The fundamental issues of connectivity, scalability, routing and topology control in MANETS is worth to study. Graph theory plays an important role to study these fundamental issues. This paper highights the concepts of graph theory that are employed to address these fundamental issues. This paper also highights the importance of MANET simulation and also gives an insight into the various simulation models that are used currenty.

Weight reduction techniques have been practiced by automobile manufacturers for the purpose of long range, less fuel consumption and achieving higher speeds. Due to the numerous set objectives that must be met, especially with respect to of car safety, automotive chassis design for vehicle weight reduction is a difficult task. In passenger classed vehicles using a monocoque chassis for vehicle construction has been a great solution for reducing overall wight of the vehicle body yet the structure is more stiffened and sturdier. However, some parts such as A-pillar, B-pillar, roof structure, floor pan can be further optimized to reduce more weight without affecting the strength needed for respective purposes. In this paper, the main focus is on reducing weight of the B-pillar. The B-pillar of a passenger car has been optimized using topology optimization and optimum weight reduction has been done. The modelling and simulation are done using SOLIDWORKS 3D software. The B-pillar in this study has been subjected to a static load of 140 KN. Further by providing goals and constraints the optimization was caried out. The results of Finite Element Analysis (FEA) of the original model are explained. The Topology Optimization resulted in reducing 53% of the original weight of the B-pillar.

In 2003 the Roadmapping Initiative of the European Center of Power Electronics (ECPE) has been started based on a future vision of society in 2020 in order to define the future role of power electronics, and to identify technological barriers and prepare new technologies well in time. In the framework of this initiative a new mathematically supported approach for the roadmapping in power electronics has been developed. As described in this paper the procedure relies on a comprehensive mathematical modeling and subsequent multi-objective optimization of a converter system. The relationship between the technological base and the performance of the system then exists as a mathematical representation, whose optimization assures the best possible exploitation of the available degrees of freedom and technologies. Thus an objective Technology Node of a system is obtained, whereby physical limits are implicitly taken into account. Furthermore, the sensitivity of the system performance with ...

In this second part of a series of articles, we discuss the fusion of analogue and digital decurring from the Klein Bottle, the Inside/Outside image-schema of Cognitive Semantics and its role in the dualistic organization of knowledge, presenting several examples in biology, astrophysics and chemistry. We present the Möbius strips and Klein Bottle (KB) and HyperKlein Bottles non-orientable surfaces, the non-dual logic and logophysics of the KB, that surmount this dualism, and their elementary harmonics, and the relation with palindromes .We present a corresponding topological protoform of Newton's Third Law surmounting its dualistic character. We discuss Chemical Topology as a paradigm incorporating at its foundations the Klein Bottle ontology and logophysics, and particularly the characterization of life as artifact-making, of molecular complementarity and of semiotic agency as related to self-reference. We discuss the relation between these surfaces and enantiomerism and the existence of a bodyplan for humans related to them and give several examples of its manifestation. We discuss the relations between the Inside/Outside image-schema and its surmountal by the Klein Bottle logophysics in biology, chemistry, astrophysics, holography, metamathematics, and of the location of the real world. We introduce the non-orientable topology of the action/perception cycle and discuss the KB topology of the visual and somatosensory cortical mappings, music perception and of electromagnetic and sound vortices. We discuss the Inside/Outside image-schema and its relations to the topologies of genomes.

Constantly growing demands of high productivity and security of computer systems and computer networks call the
interest of specialists in the environment of construction of optimum topologies of computer mediums. In earliest
phases of design, the study of the topological influence of the processes that happen in computer systems and
computer networks allows to obtain useful information which possesses a significant value in the subsequent design.
It has always been tried to represent the different computer network topologies using appropriate graph models.
Graphs have huge contributions towards the performance improvement factor of a network. Some major
contributors are de-Bruijn, Hypercube, Mesh and Pascal. They had been studied a lot and different new features
were always a part of research outcome. As per the definition of interconnection network it is equivalent that a
suitable graph can represent the physical and logical layout very efficiently. In this present study Pascal graph is
researched again and a new characteristics has been discovered. From the perspective of network topologies Pascal
graph and its properties were first studied more than two decades back. Since then, a numerous graph models have
emerged with potentials to be used as network topologies. This new property is guaranteed to make an everlasting
mark towards the reliability of this graph to be used as a substantial contributor as a computer network topology.
This shows its credentials over so many other topologies. This study reviews the characteristics of the Pascal graph
and the new property is established using appropriate algorithm and the results

Constantly growing demands of high productivity and security of computer systems and computer networks call the interest of specialists in the environment of construction of optimum topologies of computer mediums. In earliest phases of design, the study of the topological influence of the processes that happen in computer systems and computer networks allows to obtain useful information which possesses a significant value in the subsequent design. It has always been tried to represent the different computer network topologies using appropriate graph models. Graphs have huge contributions towards the performance improvement factor of a network. Some major contributors are de-Bruijn, Hypercube, Mesh and Pascal. They had been studied a lot and different new features were always a part of research outcome. As per the definition of interconnection network it is equivalent that a suitable graph can represent the physical and logical layout very efficiently. In this present study Pascal graph is researched again and a new characteristics has been discovered. From the perspective of network topologies Pascal graph and its properties were first studied more than two decades back. Since then, a numerous graph models have emerged with potentials to be used as network topologies. This new property is guaranteed to make an everlasting mark towards the reliability of this graph to be used as a substantial contributor as a computer network topology. This shows its credentials over so many other topologies. This study reviews the characteristics of the Pascal graph and the new property is established using appropriate algorithm and the results.

In order for simulation studies to be useful, it is very important that the simulation results match as closely as possible with the testbed results. This paper compares emulated testbed results with simulation results from NS2 and GloMoSim. OLSR was used as a routing protocol and NRL Mobile Network Emulator (MNE) for dynamic topology control and manipulation. Five Linux based laptops, equipped with IEEE 802.11b wireless network cards were used for testbed implementation. At low traffic rates, testbed results matched closely with the simulation results, at higher traffic rates, testbed results not only differed from the simulation results both qualitatively and quantitatively but the simulation results from both the simulators were barely comparable in some scenarios.

A new free-from deforma- tion method is presented in this paper. Object deformation is controlled by a mesh of arbitrary topology, namely a control mesh. The subdivision sur- face determined by the control mesh spans an intermediate deformation space. The object is embedded into the space by the nearest point rule. When the shape of the control mesh is changed,

The lifetime of wireless sensor networks (WSNs) are considered one of the most challenges that face the topology control of WSNs. Topology control of WSNs is a technique to optimize the connections between nodes to reduce the interference between them, save energy and extend network lifetime. In this paper proposed an algorithm based on Whale Optimization Algorithm (WOA) called WOTC, the paper provides a discrete version of the WOA, where the position of each Whale is calculate and represented in a binary format. The proposed fitness function is designed to consider two main target; a minimization in numbers of active nodes, and low energy consumption within these nodes to overcome challenges that face topology control to prolong the WSNs lifetime, the simulations were carried out using Attaraya a simulator. Consequently, the results showed that the final topology obtained by WOTC is better than A3 topology depending on the number of neighbors and their energies for active nodes, use a graph traversal function to ensure that all nodes which selected in network are covered in the best topology selection.

In order to evaluate the behavior and performance of protocols for wireless networks, simulations are a good compromise between cost and complexity, on the one hand, and accuracy of the results, on the other hand. Since there are many simulators for wireless networks, it is often difficult to decide which simulator to choose. To help shed light on this issue, we present a case study in which four popular wireless network simulators were used to evaluate a well-known topology control protocol (SPAN). Within the case study, we describe outstanding and desirable but missing features of the simulators, outlining their strengths and weaknesses. Further, we compare the amount of effort needed for installation, familiarization, implementation (needed lines of code and lines for configuration) and visualization. As opposed to other simulator comparisons, we do not focus on the correlation of the individual simulation results, but try to compare the simulators from feature and usability point of view. This paper can help other researchers to quickly identify which simulator is most suitable for their needs.

In this paper, we study and improve the recovery p roperties of single- and multipath routing strategies when facing networ k failure situations. In particular, we focus our study on two MANET routing protocols: OLSR and its multipath extension MP-OLSR. In various wireless multi-hop network environments, especially in multiple chain topologi es, we define and seek to evaluate the latency

In this article, we design techniques that exploit data correlations in sensor data to minimize communication costs (and hence, energy costs) incurred during data gathering in a sensor network. Our proposed approach is to select a small subset of sensor nodes that may be sufficient to reconstruct data for the entire sensor network. Then, during data gathering only the selected sensors need to be involved in communication. The selected set of sensors must also be connected, since they need to relay data to the data-gathering node. We define the problem of selecting such a set of sensors as the connected correlation-dominating set problem, and formulate it in terms of an appropriately defined correlation structure that captures general data correlations in a sensor network. We develop a set of energy-efficient distributed algorithms and competitive centralized heuristics to select a connected correlation-dominating set of small size. The designed distributed algorithms can be implemen...

The worldwide demand for broadband communications is being met in many places by installed single-mode fiber networks. However, there is still a significant "first-mile" problem, which seriously limits the availability of broadband Internet access. Free-space optical wireless communications has emerged as a viable technology for bridging gaps in existing high-data-rate communications networks, and as a temporary backbone for rapidly deployable

The notion of Q* - open sets in a topological space was introduced by Murugalingam and Lalitha [ 7 ]. We
introduce the notion of Q*s - regular, Q*s - normal, s*Q* - normal and obtain some characterizations Q*s -
regularity and Q*s – normality, s*Q* - normal.