Abstract: This paper presents a pulse doubling technique in a 12-pulse ac-dc converter which supplies direct torque controlled motor drives (DTCIMD-s) in order to have better power quality conditions at the point of common coupling. The proposed technique increases the number of rectification pulses without significant changes in the installations and yields in harmonic reduction in both ac and dc sides. The 12-pulse rectified output voltage is accomplished via two paralleled six-pulse ac-dc converters each of them consisting of three-phase diode bridge rectifier. An autotransformer is designed to supply the rectifiers. The design procedure of magnetics is in a way such that makes it suitable for retrofit applications where a six-pulse diode bridge rectifier is being utilized. Independent operation of paralleled diode-bridge rectifiers, i.e. dc-ripple re-injection methodology, requires a Zero Sequence Blocking Transformer (ZSBT). Finally, a tapped interphase reactor is connected at the output of ZSBT to double the pulse numbers of output voltage up to 24 pulses. The aforementioned structure improves power quality criteria at ac mains and makes them consistent with the IEEE-519 standard requirements for varying loads. Furthermore, near unity power factor is obtained for a wide range of DTCIMD operation. A comparison is made between 6- pulse, 12-pulse, and proposed converters from view point of power quality indices. Results show that input current total harmonic distortion (THD) is less than 5% for the proposed topology at various loads.
Abstract: Typical Intelligent Decision Support System is 4-based, its design composes of Data Warehouse, Online Analytical Processing, Data Mining and Decision Supporting based on models, which is called Decision Support System Based on Data Warehouse (DSSBDW). This way takes ETL,OLAP and DM as its implementing means, and integrates traditional model-driving DSS and data-driving DSS into a whole. For this kind of problem, this paper analyzes the DSSBDW architecture and DW model, and discusses the following key issues: ETL designing and Realization; metadata managing technology using XML; SQL implementing, optimizing performance, data mapping in OLAP; lastly, it illustrates the designing principle and method of DW in DSSBDW.
Abstract: In this paper, a nonconforming mixed finite element method is studied for semilinear pseudo-hyperbolic partial integrodifferential equations. By use of the interpolation technique instead of the generalized elliptic projection, the optimal error estimates of the corresponding unknown function are given.
Abstract: Dioscorea species or commonly named as yam is
reported to be one of the major food sources worldwide. This
ethnobotanical study was conducted to document local knowledge
and potentials of DioscoreahispidaDennst. and to investigate and
record its distribution in three districts of Terengganu. Information
was gathered from 23 villagers from three districts of Besut, Marang
and Setiu by using semi-structured questionnaire. The villagers were
randomly selected and no appointment was made prior to the visits.
For distribution, the location of Dioscoreahispida was recorded by
using the Global Positioning System (GPS). The villagers identified
Dioscoreahispida or locally named ubigadong by looking at the
physical characteristics that include its leaf shape, stem and the color
of the tuber-s flesh. The villagers used Dioscoreahispida in many
ways in their life such as for food, medicinal purposes and fish
poison.
Abstract: Presently and in line with the United Nations (EPA),
human thinking system has shifted towards clean fuels so as to
maintain a cleaner environment and to save our planet earth.
One of the most successful studies in order to achieve new
energies includes the use of animal wastes and their organic residues,
and the result of these researches has been represented in the form of
very simple and cheap methods called biogas technology. Biogas
technology has developed a lot in the recent decades; its reason is the
high cost of fossil fuels and the greater attention of countries to the
environmental pollutions due to the consumption of this kind of
fuels.
IRAN is ready for the optimized application of renewable
energies, having much enriched resources of this kind of energies; so
a special place could be considered for it when making programs.
The purpose of biogas technology is the recovery of energy and
finally the protection of the environment, which is much appropriate
for the third world farmers with respect to their technical abilities and
economic potentials. Studies show that the production and
consumption of biogas is appropriate and economic in IRAN,
because of the high amount of waste in the agriculture sector, the
significant amount of animal and human excrement production, the
great volume of garbage produced and the most important the
specific social, climatic and agricultural conditions in IRAN, in order
to proceed towards the reduction of pollution due to the use of fossil
fuels.
Abstract: Various intelligences and inspirations have been
adopted into the iterative searching process called as meta-heuristics.
They intelligently perform the exploration and exploitation in the
solution domain space aiming to efficiently seek near optimal
solutions. In this work, the bee algorithm, inspired by the natural
foraging behaviour of honey bees, was adapted to find the near
optimal solutions of the transportation management system, dynamic
multi-zone dispatching. This problem prepares for an uncertainty and
changing customers- demand. In striving to remain competitive,
transportation system should therefore be flexible in order to cope
with the changes of customers- demand in terms of in-bound and outbound
goods and technological innovations. To remain higher service
level but lower cost management via the minimal imbalance scenario,
the rearrangement penalty of the area, in each zone, including time
periods are also included. However, the performance of the algorithm
depends on the appropriate parameters- setting and need to be
determined and analysed before its implementation. BEE parameters
are determined through the linear constrained response surface
optimisation or LCRSOM and weighted centroid modified simplex
methods or WCMSM. Experimental results were analysed in terms
of best solutions found so far, mean and standard deviation on the
imbalance values including the convergence of the solutions
obtained. It was found that the results obtained from the LCRSOM
were better than those using the WCMSM. However, the average
execution time of experimental run using the LCRSOM was longer
than those using the WCMSM. Finally a recommendation of proper
level settings of BEE parameters for some selected problem sizes is
given as a guideline for future applications.
Abstract: Multiplication algorithms have considerable effect on
processors performance. A new high-speed, low-power
multiplication algorithm has been presented using modified Dadda
tree structure. Three important modifications have been implemented
in inner product generation step, inner product reduction step and
final addition step. Optimized algorithms have to be used into basic
computation components, such as multiplication algorithms. In this
paper, we proposed a new algorithm to reduce power, delay, and
transistor count of a multiplication algorithm implemented using low
power modified counter. This work presents a novel design for
Dadda multiplication algorithms. The proposed multiplication
algorithm includes structured parts, which have important effect on
inner product reduction tree. In this paper, a 1.3V, 64-bit carry hybrid
adder is presented for fast, low voltage applications. The new 64-bit
adder uses a new circuit to implement the proposed carry hybrid
adder. The new adder using 80 nm CMOS technology has been
implemented on 700 MHz clock frequency. The proposed
multiplication algorithm has achieved 14 percent improvement in
transistor count, 13 percent reduction in delay and 12 percent
modification in power consumption in compared with conventional
designs.
Abstract: A novel three-phase active power filter (APF) circuit with photovoltaic (PV) system to improve the quality of service and to reduce the capacity of energy storage capacitor is presented. The energy balance concept and sampling technique were used to simplify the calculation algorithm for the required utility source current and to control the voltage of the energy storage capacitor. The feasibility was verified by using the Pspice simulations and experiments. When the APF mode was used during non-operational period, not only the utilization rate, power factor and power quality could be improved, but also the capacity of energy storage capacitor could sparing. As the results, the advantages of the APF circuit are simplicity of control circuits, low cost, and good transient response.
Abstract: Virtual engineering technology has undergone rapid progress in recent years and is being adopted increasingly by manufacturing companies of many engineering disciplines. There is an increasing demand from industry for qualified virtual engineers. The qualified virtual engineers should have the ability of applying engineering principles and mechanical design methods within the commercial software package environment. It is a challenge to the engineering education in universities which traditionally tends to lack the integration of knowledge and skills required for solving real world problems. In this paper, a case study shows some recent development of a MSc Mechanical Engineering course at Department of Engineering and Technology in MMU, and in particular, two units Simulation of Mechanical Systems(SMS) and Computer Aided Fatigue Analysis(CAFA) that emphasize virtual engineering education and promote integration of knowledge acquisition, skill training and industrial application.
Abstract: Thanks to VR technology advanced, there are many
researches had used VR technology to develop a training system.
Using VR characteristics can simulate many kinds of situations to
reach our training-s goal. However, a good training system not only
considers real simulation but also considers learner-s learning
motivation. So, there are many researches started to conduct game-s
features into VR training system. We typically called this is a serious
game. It is using game-s features to engage learner-s learning
motivation. However, VR or Serious game has another important
advantage. That is simulating feature. Using this feature can create
any kinds of pressured environments. Because in the real
environment may happen any emergent situations. So, increasing the
trainees- pressure is more important when they are training. Most
pervious researches are investigated serious game-s applications and
learning performance. Seldom researches investigated how to
increase the learner-s mental workload when they are training. So, in
our study, we will introduce a real case study and create two types
training environments. Comparing the learner-s mental workload
between VR training and serious game.
Abstract: Nosocomial (i.e., hospital-acquired) infections
(NI) is a major cause of morbidity and mortality in hospitals. NI
rate is higher in intensive care units (ICU) than in the general
ward due to patients with severe symptoms, poor immunity,
and accepted many invasive therapies. Contact behaviors
between health caregivers and patients is one of the infect
factors. It is difficult to obtain complete contact records by
traditional method of retrospective analysis of medical records.
This paper establishes a contact history inferential model
(CHIM) intended to extend the use of Proximity Sensing of
rapid frequency identification (RFID) technology to
transferring all proximity events between health caregivers and
patients into clinical events (close-in events, contact events and
invasive events).The results of the study indicated that the
CHIM can infer proximity care activities into close-in events
and contact events.
The infection control team could redesign and build optimal
workflow in the ICU according to the patient-specific contact
history which provided by our automatic tracing system.
Abstract: The fabrication of porous NiTi shape memory alloys (SMAs) from elemental powder compacts was conducted by selfpropagating high temperature synthesis (SHS). Effects of the preheating temperature and the chamber pressure on the combustion characteristics as well as the final morphology and the composition of products were studied. The samples with porosity between 56.4 and 59.0% under preheating temperature in the range of 200-300°C and Ar-gas chamber pressure of 138 and 201 kPa were obtained. The pore structures were found to be dissimilar only in the samples processed with different preheating temperature. The major phase in the porous product is NiTi with small amounts of secondary phases, NiTi2 and Ni4Ti3. The preheating temperature and the chamber pressure have very little effect on the phase constituent. While the combustion temperature of the sample was notably increased by increasing the preheating temperature, they were slightly changed by varying the chamber pressure.
Abstract: This paper presents a review on vision aided systems
and proposes an approach for visual rehabilitation using stereo vision
technology. The proposed system utilizes stereo vision, image
processing methodology and a sonification procedure to support
blind navigation. The developed system includes a wearable
computer, stereo cameras as vision sensor and stereo earphones, all
moulded in a helmet. The image of the scene infront of visually
handicapped is captured by the vision sensors. The captured images
are processed to enhance the important features in the scene in front,
for navigation assistance. The image processing is designed as model
of human vision by identifying the obstacles and their depth
information. The processed image is mapped on to musical stereo
sound for the blind-s understanding of the scene infront. The
developed method has been tested in the indoor and outdoor
environments and the proposed image processing methodology is
found to be effective for object identification.
Abstract: In this study, we illustrated the performance and
microbial community of single- and two-phase systems anaerobically
co-digesting cassava pulp and pig manure. The results showed that
the volatile solid reduction and biogas productivity of two-phase
CSTR were 66 ± 4% and 2000 ± 210 ml l-1 d-1, while those of singlephase
CSTR were 59 ± 1% and 1670 ± 60 ml l-1 d-1, respectively. Codigestion
in two-phase CSTR gave higher 12% solid degradation and
25% methane production than single-phase CSTR. Phylogenetic
analysis of 16S rDNA clone library revealed that the Bacteroidetes
were the most abundant group, followed by the Clostridia in singlephase
CSTR. In hydrolysis/acidification reactor of two-phase system,
the bacteria within the phylum Firmicutes, especially Clostridium,
Eubacteriaceae and Lactobacillus were the dominant phylogenetic
groups. Among the Archaea, Methanosaeta sp. was the exclusive
predominant in both digesters while the relative abundance of
Methanosaeta sp. and Methanospirillum hungatei differed between
the two systems.
Abstract: Greenhouse gases (GHG) emissions impose major
threat to global warming potential (GWP). Unfortunately
manufacturing sector is one of the major sources that contribute
towards the rapid increase in greenhouse gases (GHG) emissions. In
manufacturing sector electric power consumption is the major driver
that influences CO2 emission. Titanium alloys are widely utilized in
aerospace, automotive and petrochemical sectors because of their
high strength to weight ratio and corrosion resistance. Titanium
alloys are termed as difficult to cut materials because of their poor
machinability rating. The present study analyzes energy consumption
during cutting with reference to material removal rate (MRR).
Surface roughness was also measured in order to optimize energy
consumption.
Abstract: This paper discusses on the use of Spline Interpolation
and Mean Square Error (MSE) as tools to process data acquired from
the developed simulator that shall replicate sea bed logging environment.
Sea bed logging (SBL) is a new technique that uses marine
controlled source electromagnetic (CSEM) sounding technique and is
proven to be very successful in detecting and characterizing hydrocarbon
reservoirs in deep water area by using resistivity contrasts. It uses
very low frequency of 0.1Hz to 10 Hz to obtain greater wavelength.
In this work the in house built simulator was used and was provided
with predefined parameters and the transmitted frequency was varied
for sediment thickness of 1000m to 4000m for environment with and
without hydrocarbon. From series of simulations, synthetics data were
generated. These data were interpolated using Spline interpolation
technique (degree of three) and mean square error (MSE) were
calculated between original data and interpolated data. Comparisons
were made by studying the trends and relationship between frequency
and sediment thickness based on the MSE calculated. It was found
that the MSE was on increasing trends in the set up that has the
presence of hydrocarbon in the setting than the one without. The MSE
was also on decreasing trends as sediment thickness was increased
and with higher transmitted frequency.
Abstract: Optical 1x12 fused-taper-twisted polymer optical fiber (POF) couplers has been fabricated by a perform technique. Characterization of the coupler which proposed to be used in passive night vision application to tracking a blind sport area was reported. During the development process of fused-taper-twisted POF couplers was carried out, red LED fully utilized to be injected into the couplers to test the quality of fabricated couplers. Some characterization parameters, such as optical output power, POFs attenuation characteristics and power losses on the network were observed. The maximum output power efficiency of the coupler is about 40%, but it can be improved gradually through experience and practice.
Abstract: With the turn of this century, many researchers
started showing interest in Embedded Firewall (EF) implementations.
These are not the usual firewalls that are used as checkpoints at network gateways. They are, rather, applied near those hosts that need protection. Hence by using them, individual or grouped network
components can be protected from the inside as well as from external attacks.
This paper presents a study of EF-s, looking at their architecture and problems. A comparative study assesses how practical each kind is. It particularly focuses on the architecture, weak points, and
portability of each kind. A look at their use by different categories of users is also presented.
Abstract: This study discusses the stumbling blocks stifling the
adoption of GPS technology in the public sector of Pakistan. This
study has been carried out in order to describe the value of GPS
technology and its adoption at various public sector organisations in
Pakistan. Sample size for the research conducted was 200; personnel
working in public sector having age above 29 years were surveyed.
Data collected for this research has been quantitatively analysed with
the help of SPSS. Regression analysis, correlation and cross
tabulation were the techniques used to determine the strength of
relationship between key variables. Findings of this research indicate
that main hurdles in GPS adoption in the public sector of Pakistan are
lack of awareness about GPS among masses in general and the
stakeholders in particular, lack of initiative on part of government in
promoting new technologies, unavailability of GPS infrastructure in
Pakistan and prohibitions on map availability because of security
reasons.
Abstract: This study offers a new simple method for assessing
an axial part-through crack in a pipe wall. The method utilizes simple
approximate expressions for determining the fracture parameters K,
J, and employs these parameters to determine critical dimensions of a
crack on the basis of equality between the J-integral and the J-based
fracture toughness of the pipe steel. The crack tip constraint is taken
into account by the so-called plastic constraint factor C, by which the
uniaxial yield stress in the J-integral equation is multiplied. The
results of the prediction of the fracture condition are verified by burst
tests on test pipes.