Abstract: This paper describes a UDP over IP based, server-oriented redundant host configuration protocol (RHCP) that can be used by collaborating embedded systems in an ad-hoc network to acquire a dynamic IP address. The service is provided by a single network device at a time and will be dynamically reassigned to one of the other network clients if the primary provider fails. The protocol also allows all participating clients to monitor the dynamic makeup of the network over time. So far the algorithm has been implemented and tested on an 8-bit embedded system architecture with a 10Mbit Ethernet interface.
Abstract: This paper proposes a three-phase four-wire currentcontrolled
Voltage Source Inverter (CC-VSI) for both power quality
improvement and PV energy extraction. For power quality
improvement, the CC-VSI works as a grid current-controlling shunt
active power filter to compensate for harmonic and reactive power of
loads. Then, the PV array is coupled to the DC bus of the CC-VSI
and supplies active power to the grid. The MPPT controller employs
the particle swarm optimization technique. The output of the MPPT
controller is a DC voltage that determines the DC-bus voltage
according to PV maximum power. The PSO method is simple and
effective especially for a partially shaded PV array. From computer
simulation results, it proves that grid currents are sinusoidal and inphase
with grid voltages, while the PV maximum active power is
delivered to loads.
Abstract: Health problems linked to urban growth are current
major concerns of developing countries. In 2002 and 2005, an
interdisciplinary program “Populations et Espaces ├á Risques
SANitaires" (PERSAN) was set up under the patronage of the
Development and Research Institute. Centered on health in
Cameroon-s urban environment, the program mainly sought to (i)
identify diarrhoea risk factors in Yaoundé, (ii) to measure their
prevalence and apprehend their spatial distribution. The crosssectional
epidemiological study that was carried out revealed a
diarrheic prevalence of 14.4% (437 cases of diarrhoea on the 3,034
children examined). Also, among risk factors studied, household
refuse management methods used by city dwellers were statistically
associated to these diarrhoeas. Moreover, it happened that levels of
diarrhoeal attacks varied consistently from one neighbourhood to
another because of the discrepancy urbanization process of the
Yaoundé metropolis.
Abstract: This paper presents a review on published literature
and experimental works on local sands for possible use as proppant,
specifically those from Terengganu coastal area. This includes
examination on characteristics of sand samples and selection of
experiments for proppant testing. Sand samples from identified areas
were tested according to particle size distribution, density, roundness
and sphericity, turbidity and mineralogy. Results from sand samples
were compared against proppant specifications set by API RP 56 and
selected commercial proppants. The present study found that the size
distribution, sphericity, turbidity and bulk density of Terengganu
sands are at par with some of commercial proppants. Nevertheless,
Terengganu sand samples do not completely surpass the required
roundness for use as proppant.
Abstract: Malaysia is aggressive in promoting the usage of ICT
to its mass population through the support by the government
policies and programs targeting the general population. However,
with the uneven distribution of the basic telecommunication
infrastructure between the urban and rural area, cost for being
“interconnected" that is considered high among the poorer rural
population and the lack of local contents that suit the rural population
needs or lifestyles, it is still a challenge for Malaysia to achieve its
Vision 2020 Agenda moving the nation towards an information
society by the year 2020. Among the existing programs that have
been carried out by the government to encourage the usage of ICT by
the rural population is “Kedaikom", a community telecenter with the
general aim is to engage the community to get exposed and to use the
ICT, encouraging the diffusion of the ICT technology to the rural
population. The research investigated by using a questionnaire
survey of how Kedaikom, as a community telecenter could play a
role in encouraging the rural or underserved community to use the
ICT. The result from the survey has proven that the community
telecenter could bridge the digital divide between the underserved
rural population and the well-accessed urban population in Malaysia.
More of the rural population, especially from the younger generation
and those with higher educational background are using the
community telecenter to be connected to the ICT.
Abstract: Mobile Ad hoc Networks is an autonomous system of
mobile nodes connected by multi-hop wireless links without
centralized infrastructure support. As mobile communication gains
popularity, the need for suitable ad hoc routing protocols will
continue to grow. Efficient dynamic routing is an important research
challenge in such a network. Bandwidth constrained mobile devices
use on-demand approach in their routing protocols because of its
effectiveness and efficiency. Many researchers have conducted
numerous simulations for comparing the performance of these
protocols under varying conditions and constraints. Most of them are
not aware of MAC Protocols, which will impact the relative
performance of routing protocols considered in different network
scenarios. In this paper we investigate the choice of MAC protocols
affects the relative performance of ad hoc routing protocols under
different scenarios. We have evaluated the performance of these
protocols using NS2 simulations. Our results show that the
performance of routing protocols of ad hoc networks will suffer when
run over different MAC Layer protocols.
Abstract: Added stresses due to adjacent structure should be
considered in foundation design and stress control in soil under the structure. This case is considered less than other cases in design and
calculation whereas stresses in implementation are greater than analytical stress.
Structure load are transmitted to earth by foundation and role of foundation is propagation of load on the continuous and half extreme
soil. This act cause that, present stresses lessen to allowable strength
of soil. Some researchers such as Boussinesq and westergaurd by
using of some assumption studied on this issue, theorically. Target of
this paper is study and evaluation of added stresses under structure
due to adjacent structure. For this purpose, by using of assumption, theoric relation and numeral methods, effects of adjacent structure
with 4 to 10 storeys on the main structure with 4 storeys are studied
and effect of parameters and sensitivity of them are evaluated.
Abstract: In this paper a tuning fork type structure of Ultra
Wideband (UWB) antenna is proposed. The antenna offers excellent
performance for UWB system, ranging from 3.7 GHz to 13.8 GHz.
The antenna exhibits a 10 dB return loss bandwidth over the entire
frequency band. The rectangular patch antenna is designed on FR4
substrate and fed with 50 ohms microstrip line by optimizing the
width of partial ground, the width and position of the feedline to
operate in UWB. The rectangular patch is then modified to tuning
fork structure by maintaining UWB frequency range.
Abstract: This article presents the results using a parametric approach and a Wavelet Transform in analysing signals emitting from the sperm whale. The extraction of intrinsic characteristics of these unique signals emitted by marine mammals is still at present a difficult exercise for various reasons: firstly, it concerns non-stationary signals, and secondly, these signals are obstructed by interfering background noise. In this article, we compare the advantages and disadvantages of both methods: Auto Regressive models and Wavelet Transform. These approaches serve as an alternative to the commonly used estimators which are based on the Fourier Transform for which the hypotheses necessary for its application are in certain cases, not sufficiently proven. These modern approaches provide effective results particularly for the periodic tracking of the signal's characteristics and notably when the signal-to-noise ratio negatively effects signal tracking. Our objectives are twofold. Our first goal is to identify the animal through its acoustic signature. This includes recognition of the marine mammal species and ultimately of the individual animal (within the species). The second is much more ambitious and directly involves the intervention of cetologists to study the sounds emitted by marine mammals in an effort to characterize their behaviour. We are working on an approach based on the recordings of marine mammal signals and the findings from this data result from the Wavelet Transform. This article will explore the reasons for using this approach. In addition, thanks to the use of new processors, these algorithms once heavy in calculation time can be integrated in a real-time system.
Abstract: Video sensor networks operate on stringent requirements
of latency. Packets have a deadline within which they have
to be delivered. Violation of the deadline causes a packet to be
treated as lost and the loss of packets ultimately affects the quality
of the application. Network latency is typically a function of many
interacting components. In this paper, we propose ways of reducing
the forwarding latency of a packet at intermediate nodes. The
forwarding latency is caused by a combination of processing delay
and queueing delay. The former is incurred in order to determine the
next hop in dynamic routing. We show that unless link failures in a
very specific and unlikely pattern, a vast majority of these lookups
are redundant. To counter this we propose source routing as the
routing strategy. However, source routing suffers from issues related
to scalability and being impervious to network dynamics. We propose
solutions to counter these and show that source routing is definitely
a viable option in practical sized video networks. We also propose a
fast and fair packet scheduling algorithm that reduces queueing delay
at the nodes. We support our claims through extensive simulation on
realistic topologies with practical traffic loads and failure patterns.
Abstract: Developing a supply chain management (SCM) system is costly, but important. However, because of its complicated nature, not many of such projects are considered successful. Few research publications directly relate to key success factors (KSFs) for implementing a SCM system. Motivated by the above, this research proposes a hierarchy of KSFs for SCM system implementation in the semiconductor industry by using a two-step approach. First, the literature review indicates the initial hierarchy. The second step includes a focus group approach to finalize the proposed KSF hierarchy by extracting valuable experiences from executives and managers that actively participated in a project, which successfully establish a seamless SCM integration between the world's largest semiconductor foundry manufacturing company and the world's largest assembly and testing company. Future project executives may refer the resulting KSF hierarchy as a checklist for SCM system implementation in semiconductor or related industries.
Abstract: This paper reports on investigations into capacity of a
Multiple Input Multiple Output (MIMO) wireless communication
system employing a uniform linear array (ULA) at the transmitter and
either a uniform linear array (ULA) or a uniform circular array (UCA)
antenna at the receiver. The transmitter is assumed to be surrounded by
scattering objects while the receiver is postulated to be free from
scattering objects. The Laplacian distribution of angle of arrival
(AOA) of a signal reaching the receiver is postulated. Calculations of
the MIMO system capacity are performed for two cases without and
with the channel estimation errors. For estimating the MIMO channel,
the scaled least square (SLS) and minimum mean square error
(MMSE) methods are considered.
Abstract: Memristor is also known as the fourth fundamental
passive circuit element. When current flows in one direction through
the device, the electrical resistance increases and when current flows
in the opposite direction, the resistance decreases. When the current
is stopped, the component retains the last resistance that it had, and
when the flow of charge starts again, the resistance of the circuit will
be what it was when it was last active. It behaves as a nonlinear
resistor with memory. Recently memristors have generated wide
research interest and have found many applications. In this paper we
survey the various applications of memristors which include non
volatile memory, nanoelectronic memories, computer logic,
neuromorphic computer architectures low power remote sensing
applications, crossbar latches as transistor replacements, analog
computations and switches.
Abstract: Brucellosis is a zoonotic disease; its symptoms and appearances are not exclusive in human and its traditional diagnosis is based on culture, serological methods and conventional PCR. For more sensitive, specific detection and differentiation of Brucella spp., the real time PCR method is recommended. This research has performed to determine the presence and prevalence of Brucella spp. and differentiation of Brucella abortus and Brucella melitensis in house mouse (Mus musculus) in west of Iran. A TaqMan analysis and single-step PCR was carried out in total 326 DNA of Mouse's spleen samples. From the total number of 326 samples, 128 (39.27%) gave positive results for Brucella spp. by conventional PCR, also 65 and 32 out of the 128 specimens were positive for B. melitensis, B. abortus, respectively. These results indicate a high presence of this pathogen in this area and that real time PCR is considerably faster than current standard methods for identification and differentiation of Brucella species. To our knowledge, this study is the first prevalence report of direct identification and differentiation of B. abortus and B. melitensis by real time PCR in mouse tissue samples in Iran.
Abstract: The controllable electrical loss which consists of the
copper loss and iron loss can be minimized by the optimal control of
the armature current vector. The control algorithm of current vector
minimizing the electrical loss is proposed and the optimal current
vector can be decided according to the operating speed and the load
conditions. The proposed control algorithm is applied to the
experimental PM motor drive system and this paper presents a
modern approach of speed control for permanent magnet
synchronous motor (PMSM) applied for Electric Vehicle using a
nonlinear control. The regulation algorithms are based on the
feedback linearization technique. The direct component of the current
is controlled to be zero which insures the maximum torque operation.
The near unity power factor operation is also achieved. More over,
among EV-s motor electric propulsion features, the energy efficiency
is a basic characteristic that is influenced by vehicle dynamics and
system architecture. For this reason, the EV dynamics are taken into
account.
Abstract: This paper investigates experimentally and
analytically the torsion behavior of steel fibered high strength self
compacting concrete beams reinforced by GFRP bars. Steel fibered
high strength self compacting concrete (SFHSSCC) and GFRP bars
became in the recent decades a very important materials in the
structural engineering field. The use of GFRP bars to replace steel
bars has emerged as one of the many techniques put forward to
enhance the corrosion resistance of reinforced concrete structures.
High strength concrete and GFRP bars attract designers and
architects as it allows improving the durability as well as the esthetics
of a construction. One of the trends in SFHSSCC structures is to
provide their ductile behavior and additional goal is to limit
development and propagation of macro-cracks in the body of
SFHSSCC elements. SFHSSCC and GFRP bars are tough, improve
the workability, enhance the corrosion resistance of reinforced
concrete structures, and demonstrate high residual strengths after
appearance of the first crack. Experimental studies were carried out
to select effective fiber contents. Three types of volume fraction from
hooked shape steel fibers are used in this study, the hooked steel
fibers were evaluated in volume fractions ranging between 0.0%,
0.75% and 1.5%. The beams shape is chosen to create the required
forces (i.e. torsion and bending moments simultaneously) on the test
zone. A total of seven beams were tested, classified into three groups.
All beams, have 200cm length, cross section of 10×20cm,
longitudinal bottom reinforcement of 3
Abstract: This paper presents the findings of two experiments that were performed on the Redundancy in Wireless Connection Model (RiWC) using the 802.11b standard. The experiments were simulated using OPNET 11.5 Modeler software. The first was aimed at finding the maximum number of simultaneous Voice over Internet Protocol (VoIP) users the model would support under the G.711 and G.729 codec standards when the packetization interval was 10 milliseconds (ms). The second experiment examined the model?s VoIP user capacity using the G.729 codec standard along with background traffic using the same packetization interval as in the first experiment. To determine the capacity of the model under various experiments, we checked three metrics: jitter, delay and data loss. When background traffic was added, we checked the response time in addition to the previous three metrics. The findings of the first experiment indicated that the maximum number of simultaneous VoIP users the model was able to support was 5, which is consistent with recent research findings. When using the G.729 codec, the model was able to support up to 16 VoIP users; similar experiments in current literature have indicated a maximum of 7 users. The finding of the second experiment demonstrated that the maximum number of VoIP users the model was able to support was 12, with the existence of background traffic.
Abstract: This study used positivist quantitative approach to examine the mathematical concepts acquisition of- KS4 (14-16) Special Education Needs (SENs) students within the school sector education in England. The research is based on a pilot study and the design is completely holistic in its approach with mixing methodologies. The study combines the qualitative and quantitative methods of approach in gathering formative data for the design process. Although, the approach could best be described as a mix method, fundamentally with a strong positivist paradigm, hence my earlier understanding of the differentiation of the students, student – teacher body and the various elements of indicators that is being measured which will require an attenuated description of individual research subjects. The design process involves four phases with five key stages which are; literature review and document analysis, the survey, interview, and observation; then finally the analysis of data set. The research identified the need for triangulation with Reid-s phases of data management providing scaffold for the study. The study clearly identified the ideological and philosophical aspects of educational research design for the study of mathematics by the special education needs (SENs) students in England using the virtual learning environment (VLE) platform.
Abstract: This paper presented the technique of robot control by event-related potentials (ERPs) of brain waves. Based on the proposed technique, severe physical disabilities can free browse outside world. A specific component of ERPs, N2P3, was found and used to control the movement of robot and the view of camera on the designed brain-computer interface (BCI). Users only required watching the stimuli of attended button on the BCI, the evoked potentials of brain waves of the target button, N2P3, had the greatest amplitude among all control buttons. An experimental scene had been constructed that the robot required walking to a specific position and move the view of camera to see the instruction of the mission, and then completed the task. Twelve volunteers participated in this experiment, and experimental results showed that the correct rate of BCI control achieved 80% and the average of execution time was 353 seconds for completing the mission. Four main contributions included in this research: (1) find an efficient component of ERPs, N2P3, for BCI control, (2) embed robot's viewpoint image into user interface for robot control, (3) design an experimental scene and conduct the experiment, and (4) evaluate the performance of the proposed system for assessing the practicability.
Abstract: Thermal water hammer is a special type of water
hammer which rarely occurs in heat exchangers. In biphasic fluids, if
steam bubbles are surrounded by condensate, regarding lower
condensate temperature than steam, they will suddenly collapse. As a
result, the vacuum caused by an extreme change in volume lead to
movement of the condensates in all directions and their collision the
force produced by this collision leads to a severe stress in the pipe
wall. This phenomenon is a special type of water hammer. According
to fluid mechanics, this phenomenon is a particular type of transient
flows during which abrupt change of fluid leads to sudden pressure
change inside the tube. In this paper, the mechanism of abrupt failure
of 80 tubes of 481 tubes of a methanol heat exchanger is discussed.
Initially, due to excessive temperature differences between heat
transfer fluids and simultaneous failure of 80 tubes, thermal shock
was presupposed as the reason of failure. Deeper investigation on
cross-section of failed tubes showed that failure was, ductile type of
failure, so the first hypothesis was rejected. Further analysis and more
accurate experiments revealed that failure of tubes caused by thermal
water hammer. Finally, the causes of thermal water hammer and
various solutions to avoid such mechanism are discussed.