Abstract: Sensor network applications are often data centric and
involve collecting data from a set of sensor nodes to be delivered
to various consumers. Typically, nodes in a sensor network are
resource-constrained, and hence the algorithms operating in these
networks must be efficient. There may be several algorithms available
implementing the same service, and efficient considerations may
require a sensor application to choose the best suited algorithm. In
this paper, we present a systematic evaluation of a set of algorithms
implementing the data gathering service. We propose a modular
infrastructure for implementing such algorithms in TOSSIM with
separate configurable modules for various tasks such as interest
propagation, data propagation, aggregation, and path maintenance.
By appropriately configuring these modules, we propose a number
of data gathering algorithms, each of which incorporates a different
set of heuristics for optimizing performance. We have performed
comprehensive experiments to evaluate the effectiveness of these
heuristics, and we present results from our experimentation efforts.
Abstract: Several valve stiction models have been proposed in the literature to help understand and study the behavior of sticky valves. In this paper, an alternative black-box modeling approach based on Neural Network (NN) is presented. It is shown that with proper network type and optimum model structures, the performance of the developed NN stiction model is comparable to other established method. The resulting NN model is also tested for its robustness against the uncertainty in the stiction parameter values. Predictive mode operation also shows excellent performance of the proposed model for multi-steps ahead prediction.
Abstract: A wrist-band type biosignal measurement system and its data transfer through human body communication (HBC) were investigated. An HBC method based on pulses of ultra-wide band instead of using frequency or amplitude modulations was studied and implemented since the system became very compact and it was more suited for personal or mobile health monitoring. Our system measured photo-plethysmogram (PPG) and measured PPG signals were transmitted through a finger to a monitoring PC system. The device was compact and low-power consuming. HBC communication has very strongsecurity measures since it does not use wireless network.Furthermore, biosignal monitoring system becomes handy because it does not need to have wire connections.
Abstract: With the increasing number of on-chip components and the critical requirement for processing power, Chip Multiprocessor (CMP) has gained wide acceptance in both academia and industry during the last decade. However, the conventional bus-based onchip communication schemes suffer from very high communication delay and low scalability in large scale systems. Network-on-Chip (NoC) has been proposed to solve the bottleneck of parallel onchip communications by applying different network topologies which separate the communication phase from the computation phase. Observing that the memory bandwidth of the communication between on-chip components and off-chip memory has become a critical problem even in NoC based systems, in this paper, we propose a novel 3D NoC with on-chip Dynamic Random Access Memory (DRAM) in which different layers are dedicated to different functionalities such as processors, cache or memory. Results show that, by using our proposed architecture, average link utilization has reduced by 10.25% for SPLASH-2 workloads. Our proposed design costs 1.12% less execution cycles than the traditional design on average.
Abstract: The load frequency control problem of power systems has attracted a lot of attention from engineers and researchers over the years. Increasing and quickly changing load demand, coupled with the inclusion of more generators with high variability (solar and wind power generators) on the network are making power systems more difficult to regulate. Frequency changes are unavoidable but regulatory authorities require that these changes remain within a certain bound. Engineers are required to perform the tricky task of adjusting the control system to maintain the frequency within tolerated bounds. It is well known that to minimize frequency variations, a large proportional feedback gain (speed regulation constant) is desirable. However, this improvement in performance using proportional feedback comes about at the expense of a reduced stability margin and also allows some steady-state error. A conventional PI controller is then included as a secondary control loop to drive the steadystate error to zero. In this paper, we propose a robust controller to replace the conventional PI controller which guarantees performance and stability of the power system over the range of variation of the speed regulation constant. Simulation results are shown to validate the superiority of the proposed approach on a simple single-area power system model.
Abstract: Optical burst switching (OBS) has been proposed to
realize the next generation Internet based on the wavelength division
multiplexing (WDM) network technologies. In the OBS, the burst
contention is one of the major problems. The deflection routing has
been designed for resolving the problem. However, the deflection
routing becomes difficult to prevent from the burst contentions as the
network load becomes high. In this paper, we introduce a flow rate
control methods to reduce burst contentions. We propose new flow
rate control methods based on the leaky bucket algorithm and
deflection routing, i.e. separate leaky bucket deflection method, and
dynamic leaky bucket deflection method. In proposed methods, edge
nodes which generate data bursts carry out the flow rate control
protocols. In order to verify the effectiveness of the flow rate control in
OBS networks, we show that the proposed methods improve the
network utilization and reduce the burst loss probability through
computer simulations.
Abstract: CIM is the standard formalism for modeling management
information developed by the Distributed Management Task
Force (DMTF) in the context of its WBEM proposal, designed to
provide a conceptual view of the managed environment. In this
paper, we propose the inclusion of formal knowledge representation
techniques, based on Description Logics (DLs) and the Web Ontology
Language (OWL), in CIM-based conceptual modeling, and then we
examine the benefits of such a decision. The proposal is specified
as a CIM metamodel level mapping to a highly expressive subset
of DLs capable of capturing all the semantics of the models. The
paper shows how the proposed mapping provides CIM diagrams with
precise semantics and can be used for automatic reasoning about the
management information models, as a design aid, by means of newgeneration
CASE tools, thanks to the use of state-of-the-art automatic
reasoning systems that support the proposed logic and use algorithms
that are sound and complete with respect to the semantics. Such a
CASE tool framework has been developed by the authors and its
architecture is also introduced. The proposed formalization is not
only useful at design time, but also at run time through the use of
rational autonomous agents, in response to a need recently recognized
by the DMTF.
Abstract: The analysis of electromagnetic environment using
deterministic mathematical models is characterized by the
impossibility of analyzing a large number of interacting network
stations with a priori unknown parameters, and this is characteristic,
for example, of mobile wireless communication networks. One of the
tasks of the tools used in designing, planning and optimization of
mobile wireless network is to carry out simulation of electromagnetic
environment based on mathematical modelling methods, including
computer experiment, and to estimate its effect on radio
communication devices. This paper proposes the development of a
statistical model of electromagnetic environment of a mobile
wireless communication network by describing the parameters and
factors affecting it including the propagation channel and their
statistical models.
Abstract: This article presents the results of researchrelated to the assessment protocol weightedcumulative expected transmission time (WCETT)applied to cognitive radio networks.The development work was based on researchdone by different authors, we simulated a network,which communicates wirelessly, using a licensedchannel, through which other nodes are notlicensed, try to transmit during a given time nodeuntil the station's owner begins its transmission.
Abstract: Wireless sensor networks can be used to measure and monitor many challenging problems and typically involve in monitoring, tracking and controlling areas such as battlefield monitoring, object tracking, habitat monitoring and home sentry systems. However, wireless sensor networks pose unique security challenges including forgery of sensor data, eavesdropping, denial of service attacks, and the physical compromise of sensor nodes. Node in a sensor networks may be vanished due to power exhaustion or malicious attacks. To expand the life span of the sensor network, a new node deployment is needed. In military scenarios, intruder may directly organize malicious nodes or manipulate existing nodes to set up malicious new nodes through many kinds of attacks. To avoid malicious nodes from joining the sensor network, a security is required in the design of sensor network protocols. In this paper, we proposed a security framework to provide a complete security solution against the known attacks in wireless sensor networks. Our framework accomplishes node authentication for new nodes with recognition of a malicious node. When deployed as a framework, a high degree of security is reachable compared with the conventional sensor network security solutions. A proposed framework can protect against most of the notorious attacks in sensor networks, and attain better computation and communication performance. This is different from conventional authentication methods based on the node identity. It includes identity of nodes and the node security time stamp into the authentication procedure. Hence security protocols not only see the identity of each node but also distinguish between new nodes and old nodes.
Abstract: As the disfunctions of the information society and
social development progress, intrusion problems such as malicious
replies, spam mail, private information leakage, phishing, and
pharming, and side effects such as the spread of unwholesome
information and privacy invasion are becoming serious social
problems. Illegal access to information is also becoming a problem as
the exchange and sharing of information increases on the basis of the
extension of the communication network. On the other hand, as the
communication network has been constructed as an international,
global system, the legal response against invasion and cyber-attack
from abroad is facing its limit. In addition, in an environment where
the important infrastructures are managed and controlled on the basis
of the information communication network, such problems pose a
threat to national security. Countermeasures to such threats are
developed and implemented on a yearly basis to protect the major
infrastructures of information communication. As a part of such
measures, we have developed a methodology for assessing the
information protection level which can be used to establish the
quantitative object setting method required for the improvement of the
information protection level.
Abstract: Energy Efficiency Management is the heart of a
worldwide problem. The capability of a multi-agent system as a
technology to manage the micro-grid operation has already been
proved. This paper deals with the implementation of a decisional
pattern applied to a multi-agent system which provides intelligence to
a distributed local energy network considered at local consumer level.
Development of multi-agent application involves agent
specifications, analysis, design, and realization. Furthermore, it can
be implemented by following several decisional patterns. The
purpose of present article is to suggest a new approach for a
decisional pattern involving a multi-agent system to control a
distributed local energy network in a decentralized competitive
system. The proposed solution is the result of a dichotomous
approach based on environment observation. It uses an iterative
process to solve automatic learning problems and converges
monotonically very fast to system attracting operation point.
Abstract: In large Internet backbones, Service Providers
typically have to explicitly manage the traffic flows in order to
optimize the use of network resources. This process is often referred
to as Traffic Engineering (TE). Common objectives of traffic
engineering include balance traffic distribution across the network
and avoiding congestion hot spots. Raj P H and SVK Raja designed
the Bayesian network approach to identify congestion hors pots in
MPLS. In this approach for every node in the network the
Conditional Probability Distribution (CPD) is specified. Based on
the CPD the congestion hot spots are identified. Then the traffic can
be distributed so that no link in the network is either over utilized or
under utilized. Although the Bayesian network approach has been
implemented in operational networks, it has a number of well known
scaling issues.
This paper proposes a new approach, which we call the Pragati
(means Progress) Node Popularity (PNP) approach to identify the
congestion hot spots with the network topology alone. In the new
Pragati Node Popularity approach, IP routing runs natively over the
physical topology rather than depending on the CPD of each node as
in Bayesian network. We first illustrate our approach with a simple
network, then present a formal analysis of the Pragati Node
Popularity approach. Our PNP approach shows that for any given
network of Bayesian approach, it exactly identifies the same result
with minimum efforts. We further extend the result to a more
generic one: for any network topology and even though the network
is loopy. A theoretical insight of our result is that the optimal routing
is always shortest path routing with respect to some considerations of
hot spots in the networks.
Abstract: The stability of a software system is one of the most
important quality attributes affecting the maintenance effort. Many
techniques have been proposed to support the analysis of software
stability at the architecture, file, and class level of software systems,
but little effort has been made for that at the feature (i.e., method and
attribute) level. And the assumptions the existing techniques based
on always do not meet the practice to a certain degree. Considering
that, in this paper, we present a novel metric, Stability of Software
(SoS), to measure the stability of object-oriented software systems
by software change propagation analysis using a simulation way
in software dependency networks at feature level. The approach is
evaluated by case studies on eight open source Java programs using
different software structures (one employs design patterns versus one
does not) for the same object-oriented program. The results of the
case studies validate the effectiveness of the proposed metric. The
approach has been fully automated by a tool written in Java.
Abstract: Wireless Mesh Networks (WMNs) are an emerging
technology for last-mile broadband access. In WMNs, similar to ad
hoc networks, each user node operates not only as a host but also as a
router. User packets are forwarded to and from an Internet-connected
gateway in multi-hop fashion. The WMNs can be integrated with
other networking technologies i.e. ad hoc networks, to implement a
smooth network extension. The meshed topology provides good
reliability and scalability, as well as low upfront investments. Despite
the recent start-up surge in WMNs, much research remains to be
done in standardizing the functional parameters of WMNs to fully
exploit their full potential. An edifice of the security concerns of
these networks is authentication of a new client joining an integrated
ad hoc network and such a scenario will require execution of a multihop
authentication technique. Our endeavor in this paper is to
introduce a secure authentication technique, with light over-heads
that can be conveniently implemented for the ad-hoc nodes forming
clients of an integrated WMN, thus facilitating their inter-operability.
Abstract: This paper proposes an analytical method for the
dynamics of generating firms- alliance networks along with business
phases. Dynamics in network developments have previously been
discussed in the research areas of organizational strategy rather than in
the areas of regional cluster, where the static properties of the
networks are often discussed. The analytical method introduces the
concept of business phases into innovation processes and uses
relationships called prior experiences; this idea was developed in
organizational strategy to investigate the state of networks from the
viewpoints of tradeoffs between link stabilization and node
exploration. This paper also discusses the results of the analytical
method using five cases of the network developments of firms. The
idea of Embeddedness helps interpret the backgrounds of the
analytical results. The analytical method is useful for policymakers of
regional clusters to establish concrete evaluation targets and a
viewpoint for comparisons of policy programs.
Abstract: Bandwidth allocation in wired network is less complex
and to allocate bandwidth in wireless networks is complex and
challenging, due to the mobility of source end system.This paper
proposes a new approach to bandwidth allocation to higher and lower
priority mobile nodes.In our proposal bandwidth allocation to new
mobile node is based on bandwidth utilization of existing mobile
nodes.The first section of the paper focuses on introduction to
bandwidth allocation in wireless networks and presents the existing
solutions available for allocation of bandwidth. The second section
proposes the new solution for the bandwidth allocation to higher and
lower priority nodes. Finally this paper ends with the analytical
evaluation of the proposed solution.
Abstract: Estimating the lifetime distribution of computer networks in which nodes and links exist in time and are bound for failure is very useful in various applications. This problem is known to be NP-hard. In this paper we present efficient combinatorial approaches to Monte Carlo estimation of network lifetime distribution. We also present some simulation results.
Abstract: This paper presents features that characterize power
quality disturbances from recorded voltage waveforms using wavelet
transform. The discrete wavelet transform has been used to detect
and analyze power quality disturbances. The disturbances of interest
include sag, swell, outage and transient. A power system network has
been simulated by Electromagnetic Transients Program. Voltage
waveforms at strategic points have been obtained for analysis, which
includes different power quality disturbances. Then wavelet has been
chosen to perform feature extraction. The outputs of the feature
extraction are the wavelet coefficients representing the power quality
disturbance signal. Wavelet coefficients at different levels reveal the
time localizing information about the variation of the signal.
Abstract: We consider a two-way relay network where two sources exchange information. A relay helps the two sources exchange information using the decode-and-XOR-forward protocol. We investigate the power minimization problem with minimum rate constraints. The system needs two time slots and in each time slot the required rate pair should be achievable. The power consumption is minimized in each time slot and we obtained the closed form solution. The simulation results confirm that the proposed power allocation scheme consumes lower total power than the conventional schemes.