Abstract: Power loss reduction is one of the main targets in power industry and so in this paper, the problem of finding the optimal configuration of a radial distribution system for loss reduction is considered. Optimal reconfiguration involves the selection of the best set of branches to be opened ,one each from each loop, for reducing resistive line losses , and reliving overloads on feeders by shifting the load to adjacent feeders. However ,since there are many candidate switching combinations in the system ,the feeder reconfiguration is a complicated problem. In this paper a new approach is proposed based on a simple optimum loss calculation by determining optimal trees of the given network. From graph theory a distribution network can be represented with a graph that consists a set of nodes and branches. In fact this problem can be viewed as a problem of determining an optimal tree of the graph which simultaneously ensure radial structure of each candidate topology .In this method the refined genetic algorithm is also set up and some improvements of algorithm are made on chromosome coding. In this paper an implementation of the algorithm presented by [7] is applied by modifying in load flow program and a comparison of this method with the proposed method is employed. In [7] an algorithm is proposed that the choice of the switches to be opened is based on simple heuristic rules. This algorithm reduce the number of load flow runs and also reduce the switching combinations to a fewer number and gives the optimum solution. To demonstrate the validity of these methods computer simulations with PSAT and MATLAB programs are carried out on 33-bus test system. The results show that the performance of the proposed method is better than [7] method and also other methods.
Abstract: This paper provides an in-depth study of Wireless
Sensor Network (WSN) application to monitor and control the
swiftlet habitat. A set of system design is designed and developed
that includes the hardware design of the nodes, Graphical User
Interface (GUI) software, sensor network, and interconnectivity for
remote data access and management. System architecture is proposed
to address the requirements for habitat monitoring. Such applicationdriven
design provides and identify important areas of further work
in data sampling, communications and networking. For this
monitoring system, a sensor node (MTS400), IRIS and Micaz radio
transceivers, and a USB interfaced gateway base station of Crossbow
(Xbow) Technology WSN are employed. The GUI of this monitoring
system is written using a Laboratory Virtual Instrumentation
Engineering Workbench (LabVIEW) along with Xbow Technology
drivers provided by National Instrument. As a result, this monitoring
system is capable of collecting data and presents it in both tables and
waveform charts for further analysis. This system is also able to send
notification message by email provided Internet connectivity is
available whenever changes on habitat at remote sites (swiftlet farms)
occur. Other functions that have been implemented in this system
are the database system for record and management purposes; remote
access through the internet using LogMeIn software. Finally, this
research draws a conclusion that a WSN for monitoring swiftlet
habitat can be effectively used to monitor and manage swiftlet
farming industry in Sarawak.
Abstract: Data objects are usually organized hierarchically, and
the relations between them are analyzed based on a corresponding
concept hierarchy. The relation between data objects, for example how
similar they are, are usually analyzed based on the conceptual distance
in the hierarchy. If a node is an ancestor of another node, it is enough
to analyze how close they are by calculating the distance vertically.
However, if there is not such relation between two nodes, the vertical
distance cannot express their relation explicitly. This paper tries to fill
this gap by improving the analysis method for data objects based on
hierarchy. The contributions of this paper include: (1) proposing an
improved method to evaluate the vertical distance between concepts;
(2) defining the concept horizontal distance and a method to calculate
the horizontal distance; and (3) discussing the methods to confine a
range by the horizontal distance and the vertical distance, and
evaluating the relation between concepts.
Abstract: Dredged sediment (DS) was utilized as source of
silt-clay and organic matter in artificially prepared eelgrass substrates with mountain sand (MS) as the sand media. Addition of DS showed
improved growth of eelgrass in the mixed substrates. Increase in added
DS up to 15% silt-clay showed increased shoot growth but additional
DS in 20% silt-clay mixture didn-t result to further increase in eelgrass
growth. Improved root establishment were also found for plants in pots
with added DS as shown by the increased resistance to uprooting, increased number of rhizome nodes and longer roots. Results demonstrated that addition of DS may be beneficial to eelgrass up to a
certain extent only and too much of it might be harmful to eelgrass plants.
Abstract: In this paper, to resolve the problem of existing
schemes, an alternative fast handover Proxy Mobile IPv6 (PMIPv6)
scheme using the IEEE 802.21 Media Independent Handover (MIH)
function is proposed for heterogeneous wireless networks. The proposed
scheme comes to support fast handover for the mobile node
(MN) irrespective of the presence or absence of MIH functionality
as well as L3 mobility functionality, whereas the MN in existing
schemes has to implement MIH functionality. That is, the proposed
scheme does not require the MN to be involved in MIH related signaling
required for handover procedure. The base station (BS) with MIH
functionality performs handover on behalf of the MN. Therefore, the
proposed scheme can reduce burden and power consumption of MNs
with limited resource and battery power since MNs are not required
to be involved for the handover procedure. In addition, the proposed
scheme can reduce considerably traffic overhead over wireless links
between MN and BS since signaling messages are reduced.
Abstract: IETF defines mobility support in IPv6, i.e. MIPv6, to
allow nodes to remain reachable while moving around in the IPv6
internet. When a node moves and visits a foreign network, it is still
reachable through the indirect packet forwarding from its home
network. This triangular routing feature provides node mobility but
increases the communication latency between nodes. This deficiency
can be overcome by using a Binding Update (BU) scheme, which let
nodes keep up-to-date IP addresses and communicate with each other
through direct IP routing. To further protect the security of BU, a
Return Routability (RR) procedure was developed. However, it has
been found that RR procedure is vulnerable to many attacks. In this
paper, we will propose a lightweight RR procedure based on
geometric computing. In consideration of the inherent limitation of
computing resources in mobile node, the proposed scheme is
developed to minimize the cost of computations and to eliminate the
overhead of state maintenance during binding updates. Compared with
other CGA-based BU schemes, our scheme is more efficient and
doesn-t need nonce tables in nodes.
Abstract: There are several approaches for handling multiclass classification. Aside from one-against-one (OAO) and one-against-all (OAA), hierarchical classification technique is also commonly used. A binary classification tree is a hierarchical classification structure that breaks down a k-class problem into binary sub-problems, each solved by a binary classifier. In each node, a set of classes is divided into two subsets. A good class partition should be able to group similar classes together. Many algorithms measure similarity in term of distance between class centroids. Classes are grouped together by a clustering algorithm when distances between their centroids are small. In this paper, we present a binary classification tree with tuned observation-based clustering (BCT-TOB) that finds a class partition by performing clustering on observations instead of class centroids. A merging step is introduced to merge any insignificant class split. The experiment shows that performance of BCT-TOB is comparable to other algorithms.
Abstract: Due to the complex network architecture, the mobile
adhoc network-s multihop feature gives additional problems to the
users. When the traffic load at each node gets increased, the
additional contention due its traffic pattern might cause the nodes
which are close to destination to starve the nodes more away from the
destination and also the capacity of network is unable to satisfy the
total user-s demand which results in an unfairness problem. In this
paper, we propose to create an algorithm to compute the optimal
MAC-layer bandwidth assigned to each flow in the network. The
bottleneck links contention area determines the fair time share which
is necessary to calculate the maximum allowed transmission rate used
by each flow. To completely utilize the network resources, we
compute two optimal rates namely, the maximum fair share and
minimum fair share. We use the maximum fair share achieved in
order to limit the input rate of those flows which crosses the
bottleneck links contention area when the flows that are not allocated
to the optimal transmission rate and calculate the following highest
fair share. Through simulation results, we show that the proposed
protocol achieves improved fair share and throughput with reduced
delay.
Abstract: In this paper, we proposed an efficient data
compression strategy exploiting the multi-resolution characteristic of
the wavelet transform. We have developed a sensor node called
“Smart Sensor Node; SSN". The main goals of the SSN design are
lightweight, minimal power consumption, modular design and robust
circuitry. The SSN is made up of four basic components which are a
sensing unit, a processing unit, a transceiver unit and a power unit.
FiOStd evaluation board is chosen as the main controller of the SSN
for its low costs and high performance. The software coding of the
implementation was done using Simulink model and MATLAB
programming language. The experimental results show that the
proposed data compression technique yields recover signal with good
quality. This technique can be applied to compress the collected data
to reduce the data communication as well as the energy consumption
of the sensor and so the lifetime of sensor node can be extended.
Abstract: As originally designed for wired networks, TCP (transmission control protocol) congestion control mechanism is triggered into action when packet loss is detected. This implicit assumption for packet loss mostly due to network congestion does not work well in Mobile Ad Hoc Network, where there is a comparatively high likelihood of packet loss due to channel errors and node mobility etc. Such non-congestion packet loss, when dealt with by congestion control mechanism, causes poor TCP performance in MANET. In this study, we continue to investigate the impact of the interaction between transport protocols and on-demand routing protocols on the performance and stability of 802.11 multihop networks. We evaluate the important wireless networking events caused routing change, and propose a cross layer method to delay the unnecessary routing changes, only need to add a sensitivity parameter α , which represents the on-demand routing-s reaction to link failure of MAC layer. Our proposal is applicable to the plain 802.11 networking environment, the simulation results that this method can remarkably improve the stability and performance of TCP without any modification on TCP and MAC protocol.
Abstract: In this work, we are interested in developing a speech denoising tool by using a discrete wavelet packet transform (DWPT). This speech denoising tool will be employed for applications of recognition, coding and synthesis. For noise reduction, instead of applying the classical thresholding technique, some wavelet packet nodes are set to zero and the others are thresholded. To estimate the non stationary noise level, we employ the spectral entropy. A comparison of our proposed technique to classical denoising methods based on thresholding and spectral subtraction is made in order to evaluate our approach. The experimental implementation uses speech signals corrupted by two sorts of noise, white and Volvo noises. The obtained results from listening tests show that our proposed technique is better than spectral subtraction. The obtained results from SNR computation show the superiority of our technique when compared to the classical thresholding method using the modified hard thresholding function based on u-law algorithm.
Abstract: The intermittent connectivity modifies the “always
on" network assumption made by all the distributed query processing
systems. In modern- day systems, the absence of network
connectivity is considered as a fault. Since the last upload, it might
not be feasible to transmit all the data accumulated right away over
the available connection. It is possible that vital information may be
delayed excessively when the less important information takes place
of the vital information. Owing to the restricted and uneven
bandwidth, it is vital that the mobile nodes make the most
advantageous use of the connectivity when it arrives. Hence, in order
to select the data that needs to be transmitted first, some sort of data
prioritization is essential. A continuous query processing system for
intermittently connected mobile networks that comprises of a delaytolerant
continuous query processor distributed across the mobile
hosts has been proposed in this paper. In addition, a mechanism for
prioritizing query results has been designed that guarantees enhanced
accuracy and reduced delay. It is illustrated that our architecture
reduces the client power consumption, increases query efficiency by
the extensive simulation results.
Abstract: In this paper we introduce the notion of protein interaction network. This is a graph whose vertices are the protein-s amino acids and whose edges are the interactions between them. Using a graph theory approach, we observe that according to their structural roles, the nodes interact differently. By leading a community structure detection, we confirm this specific behavior and describe thecommunities composition to finally propose a new approach to fold a protein interaction network.
Abstract: Mobile Ad hoc networks (MANETs) are collections
of wireless mobile nodes dynamically reconfiguring and collectively
forming a temporary network. These types of networks assume
existence of no fixed infrastructure and are often useful in battle-field
tactical operations or emergency search-and-rescue type of
operations where fixed infrastructure is neither feasible nor practical.
They also find use in ad hoc conferences, campus networks and
commercial recreational applications carrying multimedia traffic. All
of the above applications of MANETs require guaranteed levels of
performance as experienced by the end-user. This paper focuses on
key challenges in provisioning predetermined levels of such Quality
of Service (QoS). It also identifies functional areas where QoS
models are currently defined and used. Evolving functional areas
where performance and QoS provisioning may be applied are also
identified and some suggestions are provided for further research in
this area. Although each of the above functional areas have been
discussed separately in recent research studies, since these QoS
functional areas are highly correlated and interdependent, a
comprehensive and comparative analysis of these areas and their
interrelationships is desired. In this paper we have attempted to
provide such an overview.
Abstract: Ad hoc networks are characterized by multi-hop
wireless connectivity and frequently changing network topology.
Forming security association among a group of nodes in ad-hoc
networks is more challenging than in conventional networks due to the
lack of central authority, i.e. fixed infrastructure. With that view in
mind, group key management plays an important building block of
any secure group communication. The main contribution of this paper
is a low complexity key management scheme that is suitable for fully
self-organized ad-hoc networks. The protocol is also password
authenticated, making it resilient against active attacks. Unlike other
existing key agreement protocols, ours make no assumption about the
structure of the underlying wireless network, making it suitable for
“truly ad-hoc" networks. Finally, we will analyze our protocol to show
the computation and communication burden on individual nodes for
key establishment.
Abstract: This paper presents the communication network for
machine vision system to implement to control systems and logistics
applications in industrial environment. The real-time distributed over
the network is very important for communication among vision node,
image processing and control as well as the distributed I/O node. A
robust implementation both with respect to camera packaging and
data transmission has been accounted. This network consists of a
gigabit Ethernet network and a switch with integrated fire-wall is
used to distribute the data and provide connection to the imaging
control station and IEC-61131 conform signal integration comprising
the Modbus TCP protocol. The real-time and delay time properties
each part on the network were considered and worked out in this
paper.
Abstract: The decisions made by admission control algorithms are
based on the availability of network resources viz. bandwidth, energy,
memory buffers, etc., without degrading the Quality-of-Service (QoS)
requirement of applications that are admitted. In this paper, we
present an energy-aware admission control (EAAC) scheme which
provides admission control for flows in an ad hoc network based
on the knowledge of the present and future residual energy of the
intermediate nodes along the routing path. The aim of EAAC is to
quantify the energy that the new flow will consume so that it can
be decided whether the future residual energy of the nodes along
the routing path can satisfy the energy requirement. In other words,
this energy-aware routing admits a new flow iff any node in the
routing path does not run out of its energy during the transmission
of packets. The future residual energy of a node is predicted using
the Multi-layer Neural Network (MNN) model. Simulation results
shows that the proposed scheme increases the network lifetime. Also
the performance of the MNN model is presented.
Abstract: Wireless sensor networks (WSN) consists of many sensor nodes that are placed on unattended environments such as military sites in order to collect important information. Implementing a secure protocol that can prevent forwarding forged data and modifying content of aggregated data and has low delay and overhead of communication, computing and storage is very important. This paper presents a new protocol for concealed data aggregation (CDA). In this protocol, the network is divided to virtual cells, nodes within each cell produce a shared key to send and receive of concealed data with each other. Considering to data aggregation in each cell is locally and implementing a secure authentication mechanism, data aggregation delay is very low and producing false data in the network by malicious nodes is not possible. To evaluate the performance of our proposed protocol, we have presented computational models that show the performance and low overhead in our protocol.
Abstract: One of the key research issues in wireless sensor networks (WSNs) is how to efficiently deploy sensors to cover an area. In this paper, we present a Fishnet Based Dispatch Scheme (FiBDS) with energy aware mobility and interest based sensing angle. We propose two algorithms, one is FiBDS centralized algorithm and another is FiBDS distributed algorithm. The centralized algorithm is designed specifically for the non-time critical applications, commonly known as non real-time applications while the distributed algorithm is designed specifically for the time critical applications, commonly known as real-time applications. The proposed dispatch scheme works in a phase-selection manner. In this in each phase a specific constraint is dealt with according to the specified priority and then moved onto the next phase and at the end of each only the best suited nodes for the phase are chosen. Simulation results are presented to verify their effectiveness.
Abstract: Genetic Zone Routing Protocol (GZRP) is a new
hybrid routing protocol for MANETs which is an extension of ZRP
by using Genetic Algorithm (GA). GZRP uses GA on IERP and BRP
parts of ZRP to provide a limited set of alternative routes to the
destination in order to load balance the network and robustness
during node/link failure during the route discovery process. GZRP is
studied for its performance compared to ZRP in many folds like
scalability for packet delivery and proved with improved results. This
paper presents the results of the effect of load balancing on GZRP.
The results show that GZRP outperforms ZRP while balancing the
load.