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This paper is proposing a cross-layer optimization method in streaming video over WLAN. Packet losses of layers encoded by H.264 based scalable video codec are recovered by priority differentiated Reed Solomon erasure code. The optimal set of video layers to be transmitted and optimal FEC levels of video layers are determined under the constraints on channel condition time-varying with respect to packet loss ratio and available bandwidth. [ABSTRACT FROM AUTHOR]

Interference is one of the main challenges in designing energy efficient protocols for wireless sensor networks. Decreasing interference can reduce energy consumptions of nodes and prolong the lifetime of the network. Combining graph matching and the protocol interference model, in this paper, we propose a Matching Based Interference-Aware Dominating Set Construction Algorithm (MBIDSC), in which we consider a connected dominating set as a virtual backbone. The upper bounds of message complexity of the algorithm is ]> and the time complexity is ]> . Where n is the total number of nodes, ]> is the maximum degree of the network, r is the round of the algorithm, and d is the diameter of the network. We show the correctness of the algorithms and complexity of time and message by theoretical analysis. To the best of our knowledge, the proposed algorithm is the first results for the protocol interference model based on graph matching. [ABSTRACT FROM AUTHOR]

Sensor networks have attracted much attention in the recent years for its wide applications in biology, medicine, security and battlefield, etc. Data gathering is one of the most important operations in wireless sensor networks. In this paper, we present an energy-delay efficient data gathering protocol, SODG, for sensor networks while taking the transmission interference into considerations. The significance of this proposal is that it is fully localized and distributed, and only depends on the one-hop neighbors΄ information. To minimize the delay, the parallel transmissions are permitted with interference- free guaranteed. The experimental simulations show that our protocol is energy- delay efficient. Especially, SODG protocol improves about 64% over PEGASIS on energy consumption, and about 80% over chain-based protocols on delay. [ABSTRACT FROM AUTHOR]

Between 1927 and 1936 no one had a greater influence on Bohr's thinking than Einstein. It was Einstein's unremitting criticism which provided the severest test of Bohr's interpretation of quantum physics, and which forced him to clarify and refine his arguments. The debate between Bohr and Einstein concerning the interpretation of quantum physics is generally recognised as one of the great intellectual disputes in the history of science. What was the nature of the disagreement between them, and what were the arguments with which each defended his position? The fifth Solvay Conference, 1927 Einstein was not present at the Volta Centennial Conference at Como in September 1927, where Bohr first presented his theory of complementarity; Einstein first learned of Bohr's interpretation of quantum mechanics at the fifth Solvay Conference of Physics at Brussels in October 1927. In the discussion following Bohr's paper Einstein examined an imaginary experiment in which an electron passes through a slit in a diaphragm and impinges at a point on a hemispherical screen. This experiment, Einstein suggested, could be interpreted in either of two ways: the de Broglie–Schrödinger waves represent either (a) an ensemble of electrons spread out in space (but not an individual electron), or (b) a wave-packet corresponding to an individual electron. There is, he noted, a difficulty with the latter interpretation. [ABSTRACT FROM AUTHOR]

THE SUGGESTION OF V-A THEORY The situation discussed at the end of the last chapter was described in papers that proposed that a Universal Fermi Interaction, one that applied to all weak interactions, was a linear combination of V and A. The theory was offered by Sudarshan and Marshak (1957, 1958) and by Feynman and Gell-Mann (1958). This was exactly the opposite conclusion drawn four years earlier by Konopinski and Langer, who had stated, “As we shall interpret the evidence here, the correct law must be what is known as an STP combination” (1953, p. 261). Sudarshan and Marshak examined the available evidence from nuclear β decay and other weak interactions, including strange particle decays, and concluded that the only possible choice for a Universal Fermi Interaction was a linear combination of V and A, even though there was evidence apparently in conflict with this choice. The four experiments cited in opposition to the V-A theory were The electron–neutrino angular correlation experiment on He6 by Rustad and Ruby (1953, 1955), which gave T as the β-decay interaction. The sign of the electron polarization from muon decay. The frequency of the electron mode in pion decay. The asymmetry in polarized neutron decay, which was smaller than predicted. They suggested, All of these experiments should be redone, particularly since some of them contradict the results of other recent experiments on the weak interactions. [ABSTRACT FROM AUTHOR]

Wireless link capacity within a sensor network has direct impact on its performance and throughput. Due to dense sensor deployment, interference seems to be a key factor for varying radio link capacity and also for congestion at hot spot region. Thus it is important to handle interference while removing in-network hot spots. The main goal of this paper is to achieve maximum utilization of link capacity for each sensor node controlling congestion related packet losses. Therefore in this paper we proposed an interference and capacity aware data transport protocol for sensor networks which performs rate control over congested wireless links. Proposed approach identifies the congested links that exists in hot spots and then adapts data transmission rate of corresponding sensor nodes. Perception of radio link interferences i.e. intra-path and inter-path interferences are used to estimate the capacity of each link. Finally simulation outputs have demonstrated the effectiveness of the proposed task and showed a noticeable performance in terms of packet delivery ratio, packet delivery latency and sensor΄s runtime buffer size. [ABSTRACT FROM AUTHOR]

Unlicensed ISM band is used by various wireless technologies. Therefore, issues related to ensuring the required efficiency and quality of operation of coexisting networks become essential. The paper addresses the problem of mutual interferences between IEEE 802.11b transmitters (commercially named Wi-Fi) and Bluetooth (BT) devices.An optimization approach to modeling the topology of BT scatternets is introduced, resulting in more efficient utilization of ISM environment consisting of BT and Wi-Fi networks. To achieve it, the Integer Linear Programming approach has been proposed. Example results presented in the paper illustrate significant benefits of using the proposed modeling strategy. [ABSTRACT FROM AUTHOR]

This paper discusses about the comparative study between spatial and transform domain multimedia data hiding for communication purpose. Still image watermarking can΄t be used for real time communication. That΄s why our key objective directs towards the packet communication through still image watermarking. Since still image data hiding technique generally shows low data embedding rate or payload, it is tried to remove that problem also. Moreover, the proposed scheme has to be such one, which can minimize the co-channel interference thereby extracting the multimedia contents with lowest possible error. Based on this analysis, Zigzag modulation and RGB spatial domain and Discrete Cosine Transformed (DCT) domain techniques are proposed which shows better visual and statistical invisibility. [ABSTRACT FROM AUTHOR]

Inter-node interference is an important performance metric in inter-working multi-hop wireless networks. Such interference results from simultaneous transmissions by the nodes in these networks. Although several interference models exist in literature, these models are for specific wireless networks and MAC protocols. Due to the heterogeneity of link-level technologies in inter-working multi-hop wireless networks, it is desirable to have generic models to evaluate interference on links in inter-working multi-hop wireless networks. This paper presents a generic model to provide information about the interference level on a link irrespective of the MAC protocol in use. The model determines the probability of interference and uses the negative second moment of the distance between a receiver-node and interfering-nodes to estimate the interference power on a link. Numerical results of the performance of the model are presented. [ABSTRACT FROM AUTHOR]

This paper presents a measurement study of interference from six common devices that use the same 2.4 GHz ISM band as the IEEE 802.11 protocol. Using both controlled experiments and production environment measurements, we quantify the impact of these devices on the performance of 802.11 Wi-Fi networks. In our controlled experiments, we characterize the interference properties of these devices, as well as measure and discuss implications of interference on data, video, and voice traffic. Finally, we use measurements from a campus network to understand the impact of interference on the operational performance of the network. Overall, we find that the campus network is exposed to a large variety of non-Wi-Fi devices, and that these devices can have a significant impact on the interference level in the network. [ABSTRACT FROM AUTHOR]

Interference of links in wireless mesh networks has a great impact on the network performance. Most of previous studies of this problem are based on unrealistic interference models which in some cases lead to erroneous results. In this paper, based on realistic physical interference model we give a full classification of interference cases for two links, provided that stations composing these links are arranged on one line and data flows have the same direction. We show that in some cases channel capacity distribution between links is severe unfair and analyze how the probabilities of appearance of these cases depend on the parameters of physical layer of IEEE 802.11 and relative disposition of stations. Also, we discuss possible mechanisms to minimize these probabilities. [ABSTRACT FROM AUTHOR]

Inter-radar interference can cause the important impact to the radar detection performance because radar operates with high transmitter power, sensitive receiver and wideband. Because short-range surveillance radar is deployed rather close to each other, inter-radar interference is more critical. In this paper, the international criteria for radar interference protection is reviewed based on the ITU-R and NTIA documents, and the radar analysis is presented by taking into account the S-band short-range surveillance radar operating environments. Finally, S-band short-range surveillance radar optimum deployment is presented with the interference impact analysis. [ABSTRACT FROM AUTHOR]

The approach of using topology control to reduce interference in wireless sensor networks has attracted attention of many researchers. There are several definitions of interference in the literature. In a wireless sensor network, the interference at a node may be caused by an edge that is transmitting data [16], or it occurs because the node itself is within the transmission range of another [2], [4], [7]. The interference load of a node is either the number of nodes in the broadcasting disk defined by this node or the number of nodes whose disks cover it [2], [4], [7]. In this paper we show that the problem of assigning power level to a set of nodes in the plane to yield a connected geometric graph whose total node interference is bounded is NP-complete under both definitions. We also introduce some heuristics as well as a simplified version of an O(logn) approximation algorithm in [10] and study their performance through simulation. [ABSTRACT FROM AUTHOR]

The approach of using topology control to reduce interference in wireless sensor networks has attracted attention of many researchers. There are several definitions of interference in the literature. In a wireless sensor network, the interference at a node may be caused by an edge that is transmitting data, or it occurs because the node itself is within the transmission range of another. The interference load of an edge is the number of nodes that are in the disks defined by the end nodes of this edge with a radius which is either the Euclidean distance or the power level of the end nodes. In this paper we show that the problem of assigning power level to a set of nodes in the plane to yield a connected geometric graph whose edges have bounded interference is NP-complete under both edge interference definitions. We also study the performance of a number of heuristics through simulation. [ABSTRACT FROM AUTHOR]

Gossiping is to broadcast the message of every node to all the other nodes in multi-hop wireless networks (MWNs). This operation plays an important role and is widely used in MWNs. Interference-aware gossiping scheduling (IAGS) aims to provide an interference-free scheduling for gossiping with the minimum latency. Previous work on IAGS mostly assumes that nodes are always active, and thus is not suitable for duty-cycled scenarios. In this paper, we investigate the IAGS problem in uncoordinated duty-cycled multi-hop wireless networks (IAGS-UDC problem) under protocol interference model and unbounded-size message model. We prove that the IAGS-UDC problem is NP-hard. We propose a novel approximation algorithm called MILD for this problem. The MILD algorithm achieves an approximation ratio of 3β2(∆ + 6)|T|, where β is ]> , α denotes the ratio of the interference radius to the transmission radius, ∆ denotes the maximum node degree of the network, and |T| denotes the number of time-slots in a scheduling period. Moreover, the number of transmissions scheduled by the MILD algorithm is at most 3 times as large as the minimum number of transmissions. [ABSTRACT FROM AUTHOR]

Reducing interference is one of the main challenges in sensor networks and also in ad hoc networks. The amount of interference experienced by a node v corresponds to the number of nodes whose transmission range covers v. We study the problem of minimizing maximum interference for a given set of nodes in a sensor network. This requires finding a connected topology which minimizes the maximum interference for set of nodes. It is proved to be NP-hard by Buchin[5]. In this paper, we propose an algorithm named ˵Minimizing Interference in Sensor Network (MI-S)″, to minimize the maximum interference for a set of nodes in polynomial time maintaining the connectivity of the graph. We also present a variation of this algorithm based on local search technique. We check the results by applying the standard approximation algorithms and study different cases in which they are applicable. Finally we analyze some typical instances as well as average case instances to verify the proposed algorithm. [ABSTRACT FROM AUTHOR]

The approach of using topology control to reduce interference in wireless sensor networks has attracted attention of several researchers. There are at least two definitions of interference in the literature. In a wireless sensor network the interference at a node may be caused by an edge that is transmitting data [15], or it occurs because the node itself is within the transmission range of another [3], [1], [6]. In this paper we show that the problem of assigning power to nodes in the plane to yield a planar geometric graph whose nodes have bounded interference is NP-complete under both interference definitions. Our results provide a rigorous proof for a theorem in [15] whose proof is unconvincing. They also address one of the open issues raised in [6] where Halldórsson and Tokuyama were concerned with the receiver model of node interference, and derived an ]> upper bound for the maximum node interference of a wireless ad hoc network in the plane (∆ is the maximum interference of the so-called uniform radius network). The question as to whether this problem is NP-complete in the 2-dimensional case was left open. [ABSTRACT FROM AUTHOR]

With its abundant bandwidth and worldwide availability, the 60 GHz band has been considered as a promising solution to provide multi-Gbps wireless transmission. Different standard bodies and industrial interest groups start various projects to develop technologies in the 60 GHz band for applications such as high-definition (HD) and fast file transfer. However, until now very little efforts are made to ensure interference-free coexistence between these technologies. In this paper, we investigate the interference problem in the 60 GHz band. The ECMA-387 standard is used as a study case to illustrate how some simple techniques can mitigate the interference among heterogenous devices in the 60 GHz band. We conduct both mathematical analysis and simulations to demonstrate the performance of these simple techniques and identify some problems for future improvements. [ABSTRACT FROM AUTHOR]

The pursuit of low-growing, stable herbaceous and shrub ground covers in utility corridors has been a primary focus for researchers and managers during the past 50 years. A common assumption has been that competition for resources is the regulator of stable plant communities. That assumption may only be partially true as researchers have isolated plant chemicals that prevent seed germination and reduce tree growth in the absence of competitive factors. The role of biochemical interactions, known as allelopathy, is poorly understood in the ecological management of rights-of-way. There is an increasing body of research, however, in allied plant disciplines that may be applicable to a more complete understanding of plant community dynamics. This paper will review aspects of the science of allelopathy as they relate to integrated vegetation management. Factors such as soil texture, drainage, and allelochemical persistence may influence old-field succession, stability, and tree invasion. The development of environmentally compatible bioherbicides based on the molecular structure of allelochemicals may provide enormous opportunities for future control of vegetation. Combinations of allelochemicals may be especially effective in preventing germination and in the inhibition of tree growth. Allelochemicals as a new class of herbicide may be an answer for environmental and social concerns about current types and uses of pesticides. [ABSTRACT FROM AUTHOR]

Multi-hop wireless networks are dynamically forming networks of radio equipped nodes. Most of the early work has been motivated by scenarios where nodes are mobile, leading to both theoretical results for the capacity of the network [1] and to practical proposals for routing protocols [2]. With the recent deployment of community wireless networks, more specific attention has been given to multi-hop wireless networks composed of both mobile mesh clients and more static mesh routers which form the backbone of the wireless mesh and provide the clients with access to the Internet [3]. [ABSTRACT FROM AUTHOR]

This paper presents a methodology that permit; from the NURBS models of surfaces to finish on 3-axis CNC milling machines using ball end mill cutters; the determination of the optimum tool and the minimization of the machining times for each surface. In the proposed methodology, the accessibility problem is first analyzed and then the optimal tool is selected from a database of tools. Next, and depending on the machining method, we select automatically the optimum sweeping method and the associated machining direction for the isoparametric method, and the selection of the optimum machining angle for parallel plane method. Once the tool path is generated, the movements of the CNC machine are simulated virtually. This process allows an important reduction in machining time and therefore the machining costs. [ABSTRACT FROM AUTHOR]

As we saw in the last chapter, there was no generally agreed upon theory of muon decay processes in the early 1950s, although the decays were consistent with an STP combination. It was known that the coupling constants for those processes were approximately equal to those for nuclear β decay. This suggested the idea of a Universal Fermi Interaction that would apply to all weak interactions. The situation was quite different in the area of β-decay theory, where a consensus existed. In his 1943 review of the theory, Konopinski had noted the general support for Fermi's theory with a preference for the Gamow-Teller interaction involving the tensor (T) or axial vector (A) forms of the interaction. By the time of a 1953 review article by Konopinski and Langer, they stated, “As we shall interpret the evidence here, the correct law must be what is known as an STP combination” (1953, p. 261, emphasis added). In this section I will examine the evidence and arguments for this definite conclusion, which, as the subsequent history will show, was wrong, but not unreasonable. There were several attempts, based on general theoretical principles, to reduce the arbitrariness of the forms of the interactions involved in β decay. Recall that Critchfield and Wigner (1941) and Critchfield (1943) had, on the basis of symmetry considerations, found that the antisymmetric sum of the S, A, and P forms would fit the data. [ABSTRACT FROM AUTHOR]

In late 1956 and early 1957 the situation changed dramatically. Following a suggestion by Lee and Yang (1956) that parity, or mirror symmetry, might be violated in the weak interactions, which included β decay, a series of experiments by Wu and her collaborators (1957), by Garwin, Lederman, and Weinrich (1957), and by Friedman and Telegdi (1957a) showed conclusively that this was the case. This discovery had serious implications for the previous analyses of β decay, suggested new experiments, and pointed the way toward a new theory of β decay. We can summarize the history of this discovery as follows. During the 1950s the physics community was faced with what was known as the “θ–τ puzzle.” On one set of accepted criteria, that of identical masses and lifetimes, the θ and τ particles appeared to be the same particle. On another set of accepted criteria, that of spin and parity, they appeared to be different. The spin and parity analysis was performed on the decay products, two pions for the θ and three pions for the τ. Parity conservation was assumed in these decays and the spin and parity of the θ and τ were inferred. There were several attempts to solve this puzzle within the framework of currently accepted theories, but all of these were unsuccessful. In 1956, Lee and Yang recognized that a possible solution to the problem would be the nonconservation of parity in the weak interactions. [ABSTRACT FROM AUTHOR]

Breadth First Search Channel Assignment(BFSCA) is a hybrid channel assignment algorithm that utilize multiple radio interfaces to improve the throughput and minimize the interference within the wireless mesh network and between the mesh network and co-located wireless mesh networks. This new channel assignment scheme allow different nodes in the same network to communicate with each other without causing too much interference to their neighbors. It is introducing Multiradio Conflict Graph(MCG) to model interference in the wireless mesh network. Breadth First Search Channel Assignment considers both the fixed channels(static) and the dynamic channels to reduce interference of the network. BFSCA will increase the network throughput greatly. [ABSTRACT FROM AUTHOR]

Based on current load balance and minimum interference routing technology, a least interference optimization based dynamic multi-path routing algorithm (LI-DMA) in automatically switched optical network (ASON) is proposed. LI-DMA employs least interference technology and takes future demands into consideration while calculating routing paths. In LI-DMA, the link cost is dynamically adjusted according to its residual capacity and criticality, and the traffic is distributed to several disjoint paths equally while loading the connections. Simulation results show that, compared with conventional routing algorithms, LI-DMA can efficiently decrease the blocking probability of network and achieve better performance of load balance. [ABSTRACT FROM AUTHOR]

Aspects are now commonly used to add functionality that otherwise would cut across the structure of object systems. In this survey, both directions in the connection between aspects and formal methods are examined. On the one hand, the use of aspects to facilitate (general) software verification, and especially model checking, is demonstrated. On the other hand, the new challenges to formal specification and verification posed by aspects are defined, and several existing solutions are described. [ABSTRACT FROM AUTHOR]

Having discussed the meaning of complementarity in general and wave particle complementarity in particular, I wish now to explicate Bohr's subtle argument for the thesis that certain pairs of classical concepts which are mutually compatible in classical physics are mutually exclusive in quantum physics, i.e. the thesis of kinematic–dynamic complementarity. It is generally held that Bohr regarded the mutual exclusiveness in question as being not only epistemic but also ontic or semantic, in the sense that the uncertainty principle expresses a restriction not only on the joint measurability of canonically conjugate observables but also on the joint instantiation of the properties corresponding to these observables. I shall consider the question of the ontic or semantic construal of kinematic–dynamic complementarity in Chapter 7. Bohr's argument for complementarity in the epistemic sense is, however, more fundamental: it goes to the heart of his theory of observation and measurement in quantum physics. What, then, is Bohr's argument? The mutual exclusiveness of kinematic and dynamic properties Kinematic and dynamic attributes in quantum mechanics are mutually exclusive in the sense that they cannot be simultaneously measured; they are, in this sense, epistemically incompatible. Why did Bohr think this? His reasons may seem intricate, but they are basically quite simple. Two main factors, he maintains, account for the epistemic incompatibility: (a) measurements of these two different sorts of properties require mutually exclusive experimental arrangements, incompatible measurement procedures; (b) the indeterminability of the interaction between the object and the instrument of measurement precludes extrapolation of the different measurement results to one and the same time. [ABSTRACT FROM AUTHOR]

Compressive sensing has emerged as an important new technique in signal acquisition due to the surprising property that a sparse signal can be captured from measurements obtained at a sub-Nyquist rate. The decoding cost of compressive sensing, however, grows superlinearly with the problem size. In distributed sensor systems, the aggregate amount of compressive measurements encoded by the sensors can be substantial, and the decode cost for all the variables involved can be large. In this paper we propose a method to combine measurements from distributed sensors. With our method we can transport and store a single combined measurement set, rather than multiple sets for all sensors. We show that via source separation and joint decoding, it is possible to recover an approximate to the original signal from combined measurements using progressive reconstruction which focuses on individual sensors. This results in a reduction in the number of variables used in decoding and consequently a reduced decoding time. We show that the computed approximation to the signal can still have sufficient accuracy for target detection. We describe the combining approach and the associated progressive reconstruction, and we illustrate them with image recovery for simple target detection examples., Engineering and Applied Sciences