Abstract: In order to supplement the brittle property of concrete,
fibers are added into concrete mixtures. Compared to general concrete,
various characteristics such as tensile strength, bending strength,
bending toughness, and resistance to crack are superior, and even
when cracks occur, improvements on toughness as well as resistance
to shock are excellent due to the growth of fracture energy. Increased
function of steel fiber reinforced concrete can be differentiated
depending on the fiber dispersion, and sand percentage can be an
important influence on the fiber dispersion. Therefore, in this research,
experiments were planned on sand percentage in order to apprehend
the influence of sand percentage on the bending properties and direct
tension of SFRC and basic experiments were conducted on bending
and direct tension in order to recognize the properties of bending
properties and direct tension following the size of the aggregates and
sand percentage.
Abstract: Ad hoc networks are characterized by multihop wireless connectivity, frequently changing network topology and the need for efficient dynamic routing protocols. We compare the performance of three routing protocols for mobile ad hoc networks: Dynamic Source Routing (DSR), Ad Hoc On-Demand Distance Vector Routing (AODV), location-aided routing (LAR1).Our evaluation is based on energy consumption in mobile ad hoc networks. The performance differentials are analyzed using varying network load, mobility, and network size. We simulate protocols with GLOMOSIM simulator. Based on the observations, we make recommendations about when the performance of either protocol can be best.
Abstract: Many of the compounds present in potato are important because of their beneficial effects on health, therefore, are highly desirable in the human diet. Potato tubers contain significant amounts of anthocyanins. The aim of this research was to determine the content of anthocyanins and its relationship with the colour of organically and conventionally cultivated potato varieties. In the research eight potato samples of three potato varieties were analyzed on anthocyanins, dry matter content and color. Obtained results show that there was no significant influence on amount of anthocyanins between different cultivation environments (p>0.05) while between varieties – significant difference (p
Abstract: Due to the limited lifetime of the nodes in ad hoc and sensor networks, energy efficiency needs to be an important design consideration in any routing algorithm. It is known that by employing a virtual backbone in a wireless network, the efficiency of any routing scheme for the network can be improved. One common design for routing protocols in mobile ad hoc networks is to use positioning information; we use the node-s geometric locations to introduce an algorithm that can construct the virtual backbone structure locally in 3D environment. The algorithm construction has a constant time.
Abstract: Ion-acoustic solitary and shock waves in dense
quantum plasmas whose constituents are electrons, positrons, and
positive ions are investigated. We assume that ion velocity is weakly
relativistic and also the effects of kinematic viscosity among the
plasma constituents is considered. By using the reductive
perturbation method, the Korteweg–deVries–Burger (KdV-B)
equation is derived.
Abstract: The communication networks development and
advancement during two last decades has been toward a single goal
and that is gradual change from circuit-switched networks to packed
switched ones. Today a lot of networks operates are trying to
transform the public telephone networks to multipurpose packed
switch. This new achievement is generally called "next generation
networks". In fact, the next generation networks enable the operators
to transfer every kind of services (sound, data and video) on a
network. First, in this report the definition, characteristics and next
generation networks services and then ad-hoc networks role in the
next generation networks are studied.
Abstract: The purpose of this study is to suggest energy efficient
routing for ad hoc networks which are composed of nodes with limited
energy. There are diverse problems including limitation of energy
supply of node, and the node energy management problem has been
presented. And a number of protocols have been proposed for energy
conservation and energy efficiency. In this study, the critical point of
the EA-MPDSR, that is the type of energy efficient routing using only
two paths, is improved and developed. The proposed TP-MESR uses
multi-path routing technique and traffic prediction function to increase
number of path more than 2. It also verifies its efficiency compared to
EA-MPDSR using network simulator (NS-2). Also, To give a
academic value and explain protocol systematically, research
guidelines which the Hevner(2004) suggests are applied. This
proposed TP-MESR solved the existing multi-path routing problem
related to overhead, radio interference, packet reassembly and it
confirmed its contribution to effective use of energy in ad hoc
networks.
Abstract: An Ad hoc wireless network comprises of mobile
terminals linked and communicating with each other sans the aid of
traditional infrastructure. Optimized Link State Protocol (OLSR) is a
proactive routing protocol, in which routes are discovered/updated
continuously so that they are available when needed. Hello messages
generated by a node seeks information about its neighbor and if the
latter fails to respond to a specified number of hello messages
regulated by neighborhood hold time, the node is forced to assume
that the neighbor is not in range. This paper proposes to evaluate
OLSR routing protocol in a random mobility network having various
neighborhood hold time intervals. The throughput and delivery ratio
are also evaluated to learn about its efficiency for multimedia loads.
Abstract: Routing in MANET is extremely challenging because
of MANETs dynamic features, its limited bandwidth, frequent
topology changes caused by node mobility and power energy
consumption. In order to efficiently transmit data to destinations, the
applicable routing algorithms must be implemented in mobile ad-hoc
networks. Thus we can increase the efficiency of the routing by
satisfying the Quality of Service (QoS) parameters by developing
routing algorithms for MANETs. The algorithms that are inspired by
the principles of natural biological evolution and distributed
collective behavior of social colonies have shown excellence in
dealing with complex optimization problems and are becoming more
popular. This paper presents a survey on few meta-heuristic
algorithms and naturally-inspired algorithms.
Abstract: The lack of any centralized infrastructure in mobile ad
hoc networks (MANET) is one of the greatest security concerns in
the deployment of wireless networks. Thus communication in
MANET functions properly only if the participating nodes cooperate
in routing without any malicious intention. However, some of the
nodes may be malicious in their behavior, by indulging in flooding
attacks on their neighbors. Some others may act malicious by
launching active security attacks like denial of service. This paper
addresses few related works done on trust evaluation and
establishment in ad hoc networks. Related works on flooding attack
prevention are reviewed. A new trust approach based on the extent of
friendship between the nodes is proposed which makes the nodes to
co-operate and prevent flooding attacks in an ad hoc environment.
The performance of the trust algorithm is tested in an ad hoc network
implementing the Ad hoc On-demand Distance Vector (AODV)
protocol.
Abstract: Trauma in early life is widely regarded as a cause for
adult mental health problems. This study explores the role of
secondary trauma on later functioning in a sample of 359 university
students enrolled in undergraduate psychology classes in the United
States. Participants were initially divided into four groups based on
1) having directly experienced trauma (assaultive violence), 2)
having directly experienced trauma and secondary traumatization
through the unanticipated death of a close friend or family member
or witnessing of an injury or shocking even), 3) having no
experience of direct trauma but having experienced indirect trauma
(secondary trauma), or 4) reporting no exposure. Participants
completed a battery of measures on concepts associated with
psychological functioning which included measures of
psychological well-being, problem solving, coping and resiliency.
Findings discuss differences in psychological functioning and
resilience based on participants who experienced secondary
traumatization and assaultive violence versus secondary
traumatization alone.
Abstract: Routing in mobile ad hoc networks is a challenging task because nodes are free to move randomly. In DSR like all On- Demand routing algorithms, route discovery mechanism is associated with great delay. More Clearly in DSR routing protocol to send route reply packet, when current route breaks, destination seeks a new route. In this paper we try to change route selection mechanism proactively. We also define a link stability parameter in which a stability value is assigned to each link. Given this feature, destination node can estimate stability of routes and can select the best and more stable route. Therefore we can reduce the delay and jitter of sending data packets.
Abstract: In this paper, a mathematical model for data object replication in ad hoc networks is formulated. The derived model is general, flexible and adaptable to cater for various applications in ad hoc networks. We propose a game theoretical technique in which players (mobile hosts) continuously compete in a non-cooperative environment to improve data accessibility by replicating data objects. The technique incorporates the access frequency from mobile hosts to each data object, the status of the network connectivity, and communication costs. The proposed technique is extensively evaluated against four well-known ad hoc network replica allocation methods. The experimental results reveal that the proposed approach outperforms the four techniques in both the execution time and solution quality
Abstract: A novel physico-chemical route to produce few layer graphene nanoribbons with atomically smooth edges is reported, via acid treatment (H2SO4:HNO3) followed by characteristic thermal shock processes involving extremely cold substances. Samples were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy and X-ray photoelectron spectroscopy. This method demonstrates the importance of having the nanotubes open ended for an efficient uniform unzipping along the nanotube axis. The average dimensions of these nanoribbons are approximately ca. 210 nm wide and consist of few layers, as observed by transmission electron microscopy. The produced nanoribbons exhibit different chiralities, as observed by high resolution transmission electron microscopy. This method is able to provide graphene nanoribbons with atomically smooth edges which could be used in various applications including sensors, gas adsorption materials, composite fillers, among others.
Abstract: With the rapid advanced of technology, the industrial processes become increasingly demanding, from the point of view, power quality and controllability. The advent of multi levels inverters responds partially to these requirements. But actually, the new generation of multi-cells inverters permits to reach more performances, since, it offers more voltage levels. The disadvantage in the increase of voltage levels by the number of cells in cascades is on account of series igbts synchronisation loss, from where, a limitation of cells in cascade to 4. Regarding to these constraints, a new topology is proposed in this paper, which increases the voltage levels of the three-cell inverter from 4 to 8; with the same number of igbts, and using less stored energy in the flaying capacitors. The details of operation and modelling of this new inverter structure are also presented, then tested thanks to a three phase induction motor. KeywordsFlaying capacitors, Multi-cells inverter, pwm, switchers, modelling.
Abstract: Collaborative networked learning (hereafter CNL)
was first proposed by Charles Findley in his work “Collaborative
networked learning: online facilitation and software support" as part
of instructional learning for the future of the knowledge worker. His
premise was that through electronic dialogue learners and experts
could interactively communicate within a contextual framework to
resolve problems, and/or to improve product or process knowledge.
Collaborative learning has always been the forefront of educational
technology and pedagogical research, but not in the mainstream of
operations management. As a result, there is a large disparity in the
study of CNL, and little is known about the antecedents of network
collaboration and sharing of information among diverse employees in
the manufacturing environment. This paper presents a model to
bridge the gap between theory and practice. The objective is that
manufacturing organizations will be able to accelerate organizational
learning and sharing of information through various collaborative
Abstract: Mobile Ad Hoc Networks (MANETs) are multi-hop
wireless networks in which all nodes cooperatively maintain network
connectivity. In such a multi-hop wireless network, every node may
be required to perform routing in order to achieve end-to-end
communication among nodes. These networks are energy constrained
as most ad hoc mobile nodes today operate with limited battery
power. Hence, it is important to minimize the energy consumption of
the entire network in order to maximize the lifetime of ad hoc
networks. In this paper, a mechanism involving the integration of
load balancing approach and transmission power control approach is
introduced to maximize the life-span of MANETs. The mechanism is
applied on Ad hoc On-demand Vector (AODV) protocol to make it
as energy aware AODV (EA_AODV). The simulation is carried out
using GloMoSim2.03 simulator. The results show that the proposed
mechanism reduces the average required transmission energy per
packet compared to the standard AODV.
Abstract: Supersonic open and closed cavity flows are investigated experimentally and computationally. Free stream Mach number of two is set. Schlieren imaging is used to visualise the flow behaviour showing stark differences between open and closed. Computational Fluid Dynamics (CFD) is used to simulate open cavity of flow with aspect ratio of 4. A rear wall treatment is implemented in order to pursue a simple passive control approach. Good qualitative agreement is achieved between the experimental flow visualisation and the CFD in terms of the expansion-shock waves system. The cavity oscillations are shown to be dominated by the first and third Rossister modes combining to high fluctuations of non-linear nature above the cavity rear edge. A simple rear wall treatment in terms of a hole shows mixed effect on the flow oscillations, RMS contours, and time history density fluctuations are given and analysed.
Abstract: Kwashiorkor is one of nutritional problem in
Indonesia, which lead to decrease immune system. This condition
causes susceptibility to infectious disease, especially tuberculosis.
Development of new tuberculosis vaccine will be an important
strategy to eliminate tuberculosis in kwashiorkor. Previous research
showed that 38-kDa Mycobacterium tuberculosis protein is one of the
potent immunogen. However, the role of oral immunization with 38-
kDa Mycobacterium tuberculosis protein to the number of
lymphocytes in the rat model of kwashiorkor is still unknown. We
used kwashiorkor rat model groups with 4% and 2% low protein diet.
Oral immunization with 38-kDa Mycobacterium tuberculosis protein
given with 2 booster every week. The lymphocytes number were
measured by flowcytometry. There was no significant difference
between the number of lymphocytes in the normal rat group and the
kwashiorkor rat groups. It may reveal the role of 38-kDa
Mycobacterium tuberculosis protein as a potent immunogen that can
increase the lymphocytes number from kwashiorkor rat model same
as normal rat.
Abstract: This paper presents results of measurements campaign
carried out at a carrier frequency of 24GHz with the help of TPLINK
router in indoor line-of-sight (LOS) scenarios. Firstly, the
radio wave propagation strategies are analyzed in some rooms with
router of point to point Ad hoc network. Then floor attenuation is
defined for 3 floors in experimental region. The free space model and
dual slope models are modified by considering the influence of
corridor conditions on each floor. Using these models, indoor signal
attenuation can be estimated in modeling of indoor radio wave
propagation. These results and modified models can also be used in
planning the networks of future personal communications services.