Abstract: We investigate sonic cues for binaural sound localization within classrooms and present a structural model for the same. Two of the primary cues for localization, interaural time difference (ITD) and interaural level difference (ILD) created between the two ears by sounds from a particular point in space, are used. Although these cues do not lend any information about the elevation of a sound source, the torso, head, and outer ear carry out elevation dependent spectral filtering of sounds before they reach the inner ear. This effect is commonly captured in head related transfer function (HRTF) which aids in resolving the ambiguity from the ITDs and ILDs alone and helps localize sounds in free space. The proposed structural model of HRTF produces well controlled horizontal as well as vertical effects. The implemented HRTF is a signal processing model which tries to mimic the physical effects of the sounds interacting with different parts of the body. The effectiveness of the method is tested by synthesizing spatial audio, in MATLAB, for use in listening tests with human subjects and is found to yield satisfactory results in comparison with existing models.
Abstract: The deposition of diamond films on a Si3N4 substrate
is an attractive technique for industrial applications because of the
excellent properties of diamond. Pretreatment of substrate is very
important prior to diamond deposition to promote nucleation and
adhesion between coating and substrate. Deposition of
nanocrystalline diamonds films on silicon nitride substrate have been
carried out by HF-CVD technique using mixture of methane and
hydrogen gases. Different pretreatment of substrate including
chemical etching consists of hot acid etching and basic etching and
mechanical etching were used to study the quality of diamond formed
on the substrate. The structure and morphology of diamond coating
have been studied using X-ray Diffraction (XRD) and Scanning
Electron Microscope (SEM) while diamond film quality has been
characterized using Raman spectroscopy. AFM was used to
investigate the effect of chemical etching and mechanical
pretreatment on the surface roughness of the substrates and the
resultant morphology of nanocrystalline diamond. It was found that
diamond film deposited on as-received, basic etched and grinded
substrate shows the morphology of cauliflower while blasted and
acidic etched substrates produce smooth, continuous diamond film.
However, the Raman investigation did not show any deviation in
quality of diamond film for any pretreatment.
Abstract: This paper presents an effective technique for harmonic current mitigation using an adaptive notch filter (ANF) to estimate current harmonics. The proposed filter consists of multiple units of ANF connected in parallel structure; each unit is governed by two ordinary differential equations. The frequency estimation is carried out based on the output of these units. The simulation and experimental results show the ability of the proposed tracking scheme to accurately estimate harmonics. The proposed filter was implemented digitally in TMS320F2808 and used in the control of hybrid active power filter (HAPF). The theoretical expectations are verified and demonstrated experimentally.
Abstract: There is widespread emphasis on reform in the teaching of introductory statistics at the college level. Underpinning this reform is a consensus among educators and practitioners that traditional curricular materials and pedagogical strategies have not been effective in promoting statistical literacy, a competency that is becoming increasingly necessary for effective decision-making and evidence-based practice. This paper explains the historical context of, and rationale for reform-oriented teaching of introductory statistics (at the college level) in the health, social and behavioral sciences (evidence-based disciplines). A firm understanding and appreciation of the basis for change in pedagogical approach is important, in order to facilitate commitment to reform, consensus building on appropriate strategies, and adoption and maintenance of best practices. In essence, reform-oriented pedagogy, in this context, is a function of the interaction among content, pedagogy, technology, and assessment. The challenge is to create an appropriate balance among these domains.
Abstract: To derive the fractional flow equation oil
displacement will be assumed to take place under the so-called
diffusive flow condition. The constraints are that fluid saturations at
any point in the linear displacement path are uniformly distributed
with respect to thickness; this allows the displacement to be described
mathematically in one dimension. The simultaneous flow of oil and
water can be modeled using thickness averaged relative permeability,
along the centerline of the reservoir. The condition for fluid potential
equilibrium is simply that of hydrostatic equilibrium for which the
saturation distribution can be determined as a function of capillary
pressure and therefore, height. That is the fluids are distributed in
accordance with capillary-gravity equilibrium.
This paper focused on the fraction flow of water versus
cumulative oil recoveries using Buckley Leverett method. Several
field cases have been developed to aid in analysis. Producing watercut
(at surface conditions) will be compared with the cumulative oil
recovery at breakthrough for the flowing fluid.
Abstract: The activities of alkaline phosphatase and Ca2+ATPase in mud crab (Scylla serrata) collected from a soft-shell crab farm in Chantaburi Province, Thailand, in several stages of molting cycle were observed. The results showed that the activity of alkaline phosphatase in gill after molting was highly significant (p
Abstract: Natural fibres have emerged as the potential reinforcement material for composites and thus gain attraction by many researchers. This is mainly due to their applicable benefits as they offer low density, low cost, renewable, biodegradability and environmentally harmless and also comparable mechanical properties with synthetic fibre composites. The properties of hybrid composites highly depends on several factors, including the interaction of fillers with the polymeric matrix, shape and size (aspect ratio), and orientation of fillers [1]. In this study, natural fibre kenaf composites and kenaf/fibreglass hybrid composites were fabricated by a combination of hand lay-up method and cold-press method. The effect of different fibre types (powder, short and long) on the tensile properties of composites is investigated. The kenaf composites with and without the addition of fibreglass were then characterized by tensile testing and scanning electron microscopy. A significant improvement in tensile strength and modulus were indicated by the introduction of long kenaf/woven fibreglass hybrid composite. However, the opposite trends are observed in kenaf powder composite. Fractographic observation shows that fibre/matrix debonding causes the fibres pull out. This phenomenon results in the fibre and matrix fracture.
Abstract: This work presents a methodology for the selection
and design of propeller oriented to the experimental verification of
theoretical results. The problem of propeller selection and design
usually present itself in the following manner: a certain air volume
and static pressure are required for a certain system. Once the
necessity of fan design on a theoretical basis has been recognized, it
is possible to determinate the dimensions for a fan unit so that it will
perform in accordance with a certain set of specifications. The same
procedures in this work then can be applied in other propeller
selection.
Abstract: One of the main objectives of order reduction is to
design a controller of lower order which can effectively control the
original high order system so that the overall system is of lower
order and easy to understand. In this paper, a simple method is
presented for controller design of a higher order discrete system.
First the original higher order discrete system in reduced to a lower
order model. Then a Proportional Integral Derivative (PID)
controller is designed for lower order model. An error minimization
technique is employed for both order reduction and controller
design. For the error minimization purpose, Differential Evolution
(DE) optimization algorithm has been employed. DE method is
based on the minimization of the Integral Squared Error (ISE)
between the desired response and actual response pertaining to a
unit step input. Finally the designed PID controller is connected to
the original higher order discrete system to get the desired
specification. The validity of the proposed method is illustrated
through a numerical example.
Abstract: This paper presents design and implements a voltage
source inverter type space vector pulse width modulation (SVPWM)
for control a speed of induction motor. This scheme leads to be able
to adjust the speed of the motor by control the frequency and
amplitude of the stator voltage, the ratio of stator voltage to
frequency should be kept constant. The fuzzy logic controller is also
introduced to the system for keeping the motor speed to be constant
when the load varies. The experimental results in testing the 0.22 kW
induction motor from no-load condition to rated condition show the
effectiveness of the proposed control scheme.
Abstract: The robustness of color-based signatures in the presence of a selection of representative distortions is investigated. Considered are five signatures that have been developed and evaluated within a new modular framework. Two signatures presented in this work are directly derived from histograms gathered from video frames. The other three signatures are based on temporal information by computing difference histograms between adjacent frames. In order to obtain objective and reproducible results, the evaluations are conducted based on several randomly assembled test sets. These test sets are extracted from a video repository that contains a wide range of broadcast content including documentaries, sports, news, movies, etc. Overall, the experimental results show the adequacy of color-histogram-based signatures for video fingerprinting applications and indicate which type of signature should be preferred in the presence of certain distortions.
Abstract: Decentralized Tuple Space (DTS) implements tuple
space model among a series of decentralized hosts and provides the
logical global shared tuple repository. Replication has been introduced
to promote performance problem incurred by remote tuple access. In
this paper, we propose a replication approach of DTS allowing
replication policies self-adapting. The accesses from users or other
nodes are monitored and collected to contribute the decision making.
The replication policy may be changed if the better performance is
expected. The experiments show that this approach suitably adjusts the
replication policies, which brings negligible overhead.
Abstract: The steady coupled dissipative layers, called
Marangoni mixed convection boundary layers, in the presence of a
magnetic field and solute concentration that are formed along the
surface of two immiscible fluids with uniform suction or injection
effects is examined. The similarity boundary layer equations are
solved numerically using the Runge-Kutta Fehlberg with shooting
technique. The Marangoni, buoyancy and external pressure gradient
effects that are generated in mixed convection boundary layer flow
are assessed. The velocity, temperature and concentration boundary
layers thickness decrease with the increase of the magnetic field
strength and the injection to suction. For buoyancy-opposed flow, the
Marangoni mixed convection parameter enhances the velocity
boundary layer but decreases the temperature and concentration
boundary layers. However, for the buoyancy-assisted flow, the
Marangoni mixed convection parameter decelerates the velocity but
increases the temperature and concentration boundary layers.
Abstract: The aim of this paper is to identify an optimum
control strategy of three-phase shunt active filters to minimize the total harmonic distortion factor of the supply current. A classical PIPI cascade control solution of the output current of the active filterand the voltage across the DC capacitor based on Modulus–Optimum
criterion is taken into consideration. The control system operation
has been simulated using Matlab-Simulink environment and the results agree with the theoretical expectation. It is shown that there is
an optimum value of the DC-bus voltage which minimizes the supply current harmonic distortion factor. It corresponds to the equality of the apparent power at the output of the active filter and the apparent power across the capacitor. Finally, predicted results are verified experimentally on a MaxSine active power filter.
Abstract: The goal of a network-based intrusion detection
system is to classify activities of network traffics into two major
categories: normal and attack (intrusive) activities. Nowadays, data
mining and machine learning plays an important role in many
sciences; including intrusion detection system (IDS) using both
supervised and unsupervised techniques. However, one of the
essential steps of data mining is feature selection that helps in
improving the efficiency, performance and prediction rate of
proposed approach. This paper applies unsupervised K-means
clustering algorithm with information gain (IG) for feature selection
and reduction to build a network intrusion detection system. For our
experimental analysis, we have used the new NSL-KDD dataset,
which is a modified dataset for KDDCup 1999 intrusion detection
benchmark dataset. With a split of 60.0% for the training set and the
remainder for the testing set, a 2 class classifications have been
implemented (Normal, Attack). Weka framework which is a java
based open source software consists of a collection of machine
learning algorithms for data mining tasks has been used in the testing
process. The experimental results show that the proposed approach is
very accurate with low false positive rate and high true positive rate
and it takes less learning time in comparison with using the full
features of the dataset with the same algorithm.
Abstract: By the end of XX century in the structure of humanity some changes have been provoked: a new ethnos - Ethnos of Intellect is formed and is still being formed, beside the historical types of ethnoses: open ethnos, closed ethnos, wandering ethnos, dead ethnos, - and this event was caused by the technical progress, development of informational and transport communications, especially - by creation of Internet. The Ethnos of Intellect is something very close to the ÔÇ×Information Society“ described by J. Ellule and Y. Masuda that was regarded as the culture of XXI century, being an antithesis for technical and technicistical civilizations, but it-s necessary to indicate also the essential difference between these concepts: the Ethnos of Intellect is the antithesis of Socium. The existence of such an ethnos within human society that has already become an Information Society itself is extremely important in observing legally and informatically a new kind of reins in the hands of the political power, revealing every attempt to violate the human rights of simple citizens. A concrete example of some conjunction points of legal informatics and informatical law in a certain kind of ambiental studies of the project ''State Registre of Population'' in Russia is very eloquent.
Abstract: The move from cash accounting to accrual accounting, or rule-based to principle-based accounting, by many governments is part of an ongoing efforts in promoting a more business-like and performance-focused public sector. Using questionnaire responses from preparers of financial statements of public universities in Malaysia, this study examines the implementation challenges and benefits of principle-based accounting. Results from these responses suggest that most respondents perceived significant costs would be incurred in relation to staff training and recruitment of staffs with relevant technical knowledge. In addition, most respondents also perceived that there will be significant changes in the current accounting system and structure in order to comply with the principle-based accounting requirements. However, most respondents perceived that these changes might not result in significant benefits for management purposes, for example, financial management, budgeting and allocation of resources. Nevertheless, most respondents perceived that principle-based accounting information would facilitate the monitoring function of the board. The general perception is that adoption of principle-based accounting information is not significantly useful than rule-based accounting information is expected to change over time as preparers of the financial statements gradually understand and appreciate the benefits of principle-based accounting information. This infers that the perceived usefulness of different accounting system is a function of familiarity by the preparers.
Abstract: This paper discusses the implementation of a fuzzy logic based coordinated voltage control for a distribution system connected with distributed generations (DGs). The connection of DGs has created a challenge for the distribution network operators to keep the voltage in the system within its acceptable limits. Intelligent centralized or coordinated voltage control schemes have proven to be more reliable due to its ability to provide more control and coordination with the communication with other network devices. In this work, voltage control using fuzzy logic by coordinating three methods of control, power factor control, on load tap changer and generation curtailment is implemented on a distribution network test system. The results show that the fuzzy logic based coordination is able to keep the voltage within its allowable limits.
Abstract: Automotive suspension system is important part of car
comfort and safety. In this article automotive active suspension with
linear motor as actuator is designed using H-infinity control. This
paper is focused on comparison of different controller designed for
quart, half or full-car model (and always used for “full" car). Special
attention is placed on energy demand of the whole system. Each
controller configuration is simulated and then verified on the
hydraulic quarter car test bed.
Abstract: The protection of groundwater resources is the great
important many semiarid and arid environments. Baghan watershed
is located in the north of Kangan in the Boshehr province in Iran. The
groundwater resources have a vital role in supplying agricultural,
drinking, domestic and industrial water demand in Baghan
watershed. For our investigation into the water quality we collected
30 samples to chemical and physical analysis. The result showed the
marl and evaporation deposits that contain anhydrite and gypsum is
the main source of groundwater pollution, and one part of the
groundwater was polluted by oil and gas industrial. Another part of
the groundwater was contaminated by urban waste water. The
electrical conductivity and captions and anions increased around of
towns and gas refinery. Although the negative impact of untreated
domestic wastewater is relatively low but the results showed strongly
the negative impact of wastewater refinery is very considerable. This
negative impact increased in downstream due to shallow aquifer.
Additionally, the agents that adversely affect the quality of
groundwater come from a variety of sources, including geology,
domestic wastewater and the Jam refinery in Baghan watershed.