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: The evolutionary design of electronic circuits, or
evolvable hardware, is a discipline that allows the user to
automatically obtain the desired circuit design. The circuit
configuration is under the control of evolutionary algorithms. Several
researchers have used evolvable hardware to design electrical
circuits. Every time that one particular algorithm is selected to carry
out the evolution, it is necessary that all its parameters, such as
mutation rate, population size, selection mechanisms etc. are tuned in
order to achieve the best results during the evolution process. This
paper investigates the abilities of evolution strategy to evolve digital
logic circuits based on programmable logic array structures when
different mutation rates are used. Several mutation rates (fixed and
variable) are analyzed and compared with each other to outline the
most appropriate choice to be used during the evolution of
combinational logic circuits. The experimental results outlined in this
paper are important as they could be used by every researcher who
might need to use the evolutionary algorithm to design digital logic
circuits.
Abstract: The distance protection mainly the impedance relay which is considered as the main protection for transmission lines can be subjected to impedance measurement error which is, mainly, due to the fault resistance and to the power fluctuation. Thus, the impedance relay may not operate for a short circuit at the far end of the protected line (case of the under reach) or operates for a fault beyond its protected zone (case of overreach). In this paper, an approach to fault detection by a distance protection, which distinguishes between the faulty conditions and the effect of overload operation mode, has been developed. This approach is based on the symmetrical components; mainly the negative sequence, and it is taking into account both the effect of fault resistance and the overload situation which both have an effect upon the reliability of the protection in terms of dependability for the former and security for the latter.
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: In this paper, the relationship between learning
motivation and learning performance is explored by using exchange
theory. The relationship is concluded that external performance can
raise learning motivation and then increase learning performance. The
internal performance should be not completely neglected and the
external performance should be not attached important excessively.
The parents need self-study and must be also reeducated. The existing
education must be improved in raise of internal performance. The
incorrect learning thinking will mislead the students, parents, and
educators of next generation, when the students obtain good learning
performance in the learning environment with excess stimulants. Over
operation of external performance will result abnormal learning
thinking and violating learning goal. Learning is not only to obtain
performance. Learning quality and learning performance will be
limited as without learning motivation. The best learning motivation
is, the best learning performance is. The learning for reward is not
good for learning performance. Strategies of promoting life-long
learning are including the encouraging for learner, establishment of
good interaction learning environment, and the advertisement of the
merit and the importance of life-long learning, which can let the
learner with the correct learning motivation.
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: An important goal of parboiling is a decrease of rice broken percentage and at the beginning Selected paddy of variety of rice Tarom and soaked at three different temperatures 45 Cº, 65 Cº and 80 Cº orderly for 5 hours, 4 hours and 1.5 hours to moisture of 40 % and then in steaming stage to operate these action two steaming methods are selected steaming under pressure condition and steaming in atmosphere pressure and In the first method after exerting air, the steam pressure is increase to 1 Kg/Cm2 which is done in two different duration times of 2.5 and 5 minutes and in second method used of three times of 5,10 and 15 minutes and dry to 8% moisture and decreases of rice broken percentage at best condition in variety of Tarom of 37.2 % to 7.3 % and increases yield percentage at best condition in variety of Tarom of 69.4 % to 75.93 % and bran percentage decreased in variety of Tarom of 9.53 % to 2.2-3.2 % and this issue cause increases yield percentage in rice and use of This method is very significant for our country because broken percentage of rice in our country is 23-33 %.
Abstract: Despite of the preponderant role played by cement among the construction materials, it is today considered as a material destructing the environment due to the large quantities of carbon dioxide exhausted during its manufacture. Besides, global warming is now recognized worldwide as the new threat to the humankind against which advanced countries are investigating measures to reduce the current amount of exhausted gases to the half by 2050. Accordingly, efforts to reduce green gases are exerted in all industrial fields. Especially, the cement industry strives to reduce the consumption of cement through the development of alkali-activated geopolymer mortars using industrial byproducts like bottom ash. This study intends to gather basic data on the flowability and strength development characteristics of alkali-activated geopolymer mortar by examining its FT-IT features with respect to the effects and strength of the alkali-activator in order to develop bottom ash-based alkali-activated geopolymer mortar. The results show that the 35:65 mass ratio of sodium hydroxide to sodium silicate is appropriate and that a molarity of 9M for sodium hydroxide is advantageous. The ratio of the alkali-activators to bottom ash is seen to have poor effect on the strength. Moreover, the FT-IR analysis reveals that larger improvement of the strength shifts the peak from 1060 cm–1 (T-O, T=Si or Al) toward shorter wavenumber.
Abstract: Vertical Double Gate (DG) Metal Oxide Semiconductor Field Effect Transistor (MOSFET) is believed to suppress various short channel effect problems. The gate to channel coupling in vertical DG-MOSFET are doubled, thus resulting in higher current density. By having two gates, both gates are able to control the channel from both sides and possess better electrostatic control over the channel. In order to ensure that the transistor possess a superb turn-off characteristic, the subs-threshold swing (SS) must be kept at minimum value (60-90mV/dec). By utilizing SILVACO TCAD software, an n-channel vertical DG-MOSFET was successfully designed while keeping the sub-threshold swing (SS) value as minimum as possible. From the observation made, the value of sub-threshold swing (SS) was able to be varied by adjusting the height of the silicon pillar. The minimum value of sub-threshold swing (SS) was found to be 64.7mV/dec with threshold voltage (VTH) of 0.895V. The ideal height of the vertical DG-MOSFET pillar was found to be at 0.265 µm.
Abstract: Because of the increasing business pressures, companies must be adaptable and flexible in order to withstand them. Inadequate business processes and low level of business process orientation, that in its core accentuates business processes as opposed to business functions and focuses on process performance and customer satisfaction, hider the ability to adapt to changing environment. It has been shown in previous studies that the companies which have reached higher business process maturity level consistently outperform those that have not reached them. The aim of this paper is to provide a basic understanding of business process orientation concept and business process maturity model. Besides that the paper presents the state of business process orientation in Croatia that has been captured with a study conducted in 2013. Based on the results some practical implications and guidelines for managers are given.
Abstract: In this paper, we propose a selective mutation method
for improving the performances of genetic algorithms. In selective
mutation, individuals are first ranked and then additionally mutated
one bit in a part of their strings which is selected corresponding to
their ranks. This selective mutation helps genetic algorithms to fast
approach the global optimum and to quickly escape local optima.
This results in increasing the performances of genetic algorithms.
We measured the effects of selective mutation with four function
optimization problems. It was found from extensive experiments that
the selective mutation can significantly enhance the performances of
genetic algorithms.
Abstract: In this paper we study different similarity based approaches for the development of QSAR model devoted to the prediction of activity of antiobesity drugs. Classical similarity approaches are compared regarding to dissimilarity models based on the consideration of the calculation of Euclidean distances between the nonisomorphic fragments extracted in the matching process. Combining the classical similarity and dissimilarity approaches into a new similarity measure, the Approximate Similarity was also studied, and better results were obtained. The application of the proposed method to the development of quantitative structure-activity relationships (QSAR) has provided reliable tools for predicting of inhibitory activity of drugs. Acceptable results were obtained for the models presented here.
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: The issue of leadership has been investigated from
several perspectives; however, very less from ethical perspective.
With the growing number of corporate scandals and unethical roles
played by business leaders in several parts of the world, the need to
examine leadership from ethical perspective cannot be over
emphasized. The importance of leadership credibility has been
discussed in the authentic model of leadership. Authentic leaders
display high degree of integrity, have deep sense of purpose, and
committed to their core values. As a result they promote a more
trusting relationship in their work groups that translates into several
positive outcomes. The present study examined how authentic
leadership contribute to subordinates- trust in leadership and how this
trust, in turn, predicts subordinates- work engagement. A sample of
395 employees was randomly selected from several local banks
operating in Malaysia. Standardized tools such as ALQ, OTI, and
EEQ were employed. Results indicated that authentic leadership
promoted subordinates- trust in leader, and contributed to work
engagement. Also, interpersonal trust predicted employees- work
engagement as well as mediated the relationship between this style of
leadership and employees- work engagement.
Abstract: In a bid to improve turbine entry temperature for maximizing the thermal efficiency of the HP stage gas turbine blade, an attempt is made in this paper to compare the performance of helicoidal ducted blade cooling with turbulator of different geometric proportion. It is found from analysis that there is significant improvement in cooling characteristics for turbine blade with turbulator geometry having larger e/D ratio. Also it is found from analysis, performance is vastly improved for greater thickness of turbulator geometry.
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: Study of the vibration cylindrical shells made of
a functionally gradient material (FGM) composed of stainless
steel and nickel is important. Material properties are graded in
the thickness direction of the shell according to volume
fraction power law distribution. The objective is to study the
natural frequencies, the influence of constituent volume
fractions and the effects of boundary conditions on the natural
frequencies of the FG cylindrical shell. The study is carried
out using third order shear deformation shell theory. The
governing equations of motion of FG cylindrical shells are
derived based on shear deformation theory. Results are
presented on the frequency characteristics, influence of
constituent volume fractions and the effects of clampedclamped
boundary conditions.
Abstract: In this paper an extensive verification of the extraction
method (published earlier) that consistently accounts for self-heating
and Early effect to accurately extract both base and thermal resistance
of bipolar junction transistors is presented. The method verification is
demonstrated on advanced RF SiGe HBTs were the extracted results
for the thermal resistance are compared with those from another
published method that ignores the effect of Early effect on internal
base-emitter voltage and the extracted results of the base resistance
are compared with those determined from noise measurements. A
self-consistency of our method in the extracted base resistance and
thermal resistance using compact model simulation results is also
carried out in order to study the level of accuracy of the method.
Abstract: Regarding previous research studies it was concluded
that thin-walled fiber-cement composites are able to conduct electric
current under specific conditions. This property is ensured by using
of various kinds of carbon materials. Though carbon fibers are less
conductive than metal fibers, composites with carbon fibers were
evaluated as better current conductors than the composites with metal
fibers. The level of electric conductivity is monitored by the means of
impedance measurement of designed samples. These composites
could be used for a range of applications such as heating of
trafficable surfaces or shielding of electro-magnetic fields.
The aim of the present research was to design an element with the
ability to monitor internal processes in building structures and
prevent them from collapsing. As a typical element for laboratory
testing there was chosen a concrete column, which was repeatedly
subjected to load by simple pressure with continual monitoring of
changes in electrical properties.
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.