Abstract: ZnO nanostructures including nanowires, nanorods,
and nanoneedles were successfully deposited on GaAs substrates,
respectively, by simple two-step chemical method for the first time. A
ZnO seed layer was firstly pre-coated on the O2-plasma treated
substrate by sol-gel process, followed by the nucleation of ZnO
nanostructures through hydrothermal synthesis. Nanostructures with
different average diameter (15-250 nm), length (0.9-1.8 μm), density
(0.9-16×109 cm-2) were obtained via adjusting the growth time and
concentration of precursors. From the reflectivity spectra, we
concluded ordered and taper nanostructures were preferential for
photovoltaic applications. ZnO nanoneedles with an average diameter
of 106 nm, a moderate length of 2.4 μm, and the density of 7.2×109
cm-2 could be synthesized in the concentration of 0.04 M for 18 h.
Integrated with the nanoneedle array, the power conversion efficiency
of single junction solar cell was increased from 7.3 to 12.2%,
corresponding to a 67% improvement.
Abstract: Artificial Bee Colony (ABC) algorithm is a relatively new swarm intelligence technique for clustering. It produces higher
quality clusters compared to other population-based algorithms but with poor energy efficiency, cluster quality consistency and typically slower in convergence speed. Inspired by energy saving foraging behavior of natural honey bees this paper presents a Quality and Quantity Aware Artificial Bee Colony (Q2ABC) algorithm to improve quality of cluster identification, energy efficiency and convergence speed of the original ABC. To evaluate the performance of Q2ABC algorithm, experiments were conducted on a suite of ten benchmark UCI datasets. The results demonstrate Q2ABC outperformed ABC and K-means algorithm in the quality of clusters delivered.
Abstract: Network exchange is now widely used. However, it still
cannot avoid the problems evolving from network exchange. For
example. A buyer may not receive the order even if he/she makes the
payment. For another example, the seller possibly get nothing even
when the merchandise is sent. Some studies about the fair exchange
have proposed protocols for the design of efficiency and exploited the
signature property to specify that two parties agree on the exchange.
The information about purchased item and price are disclosed in
this way. This paper proposes a new fair network payment protocol
with off-line trusted third party. The proposed protocol can protect
the buyers- purchase message from being traced. In addition, the
proposed protocol can meet the proposed requirements. The most
significant feature is Non-transfer property we achieved.
Abstract: Mobile learning (M-learning) is the current technology that is becoming more popular. It uses the current mobile and wireless computing technology to complement the effectiveness of traditional learning process. The objective of this paper is presents a survey from 90 undergraduate students of Universiti Teknologi PETRONAS (UTP), to identify the students- perception on Mlearning. From the results, the students are willing to use M-learning. The acceptance level of the students is high, and the results obtained revealed that the respondents almost accept M-learning as one method of teaching and learning process and also able to improve the educational efficiency by complementing traditional learning in UTP.
Abstract: This paper describes an enhanced cookie-based
method for counting the visitors of web sites by using a web log
processing system that aims to cope with the ambitious goal of
creating countrywide statistics about the browsing practices of real
human individuals. The focus is put on describing a new more
efficient way of detecting human beings behind web users by placing
different identifiers on the client computers. We briefly introduce our
processing system designed to handle the massive amount of data
records continuously gathered from the most important content
providers of the Hungary. We conclude by showing statistics of
different time spans comparing the efficiency of multiple visitor
counting methods to the one presented here, and some interesting
charts about content providers and web usage based on real data
recorded in 2007 will also be presented.
Abstract: The objective of this research seeks to transmit a distance training model to the community in the upper northeastern region. The group sampling consists of 60 community leaders in the municipality of sub-district Kumphawapi, Kumphawapi Disrict, Udonthani Province. The research tools rely on the following instruments, they are : 1) the achievement test of community leaders- training and 2) the satisfaction questionnaires of community leaders. The statistics used in data analysis takes the statistical mean, percentage, standard deviation, and statistical T-test. The resulted findings reveal : 1) the efficiency of the distance training developed by the researcher for the community leaders joining in the training received the average score between in-training and post-training period higher than the setup criterion, 2) the two groups of participants in the training achieved higher knowledge than their pre-training state, 3) the comparison of the achievements between the two group presented no different results, 4) the community leaders obtained the high-to-highest satisfaction.
Abstract: This contribution deals with the relationship between
communication effectiveness and the extent of communication
among organizational units. To facilitate communication between
employees and to increase the level of understanding, the knowledge
of communication tools is necessary. Recent experience has shown
that personal communication is critical for smooth running of
companies and cannot be fully replaced by any form of technical
communication devices.
Below are presented the outcomes of the research on the
relationship between the extent of communication among
organisational units and its efficiency.
Abstract: In this paper, a fractional-order FIR differentiator
design method using the differential evolution (DE) algorithm is
presented. In the proposed method, the FIR digital filter is designed to
meet the frequency response of a desired fractal-order differentiator,
which is evaluated in the frequency domain. To verify the design
performance, another design method considered in the time-domain is
also provided. Simulation results reveal the efficiency of the proposed
method.
Abstract: In this paper we present a novel approach for wavelet compression of electrocardiogram (ECG) signals based on the set partitioning in hierarchical trees (SPIHT) coding algorithm. SPIHT algorithm has achieved prominent success in image compression. Here we use a modified version of SPIHT for one dimensional signals. We applied wavelet transform with SPIHT coding algorithm on different records of MIT-BIH database. The results show the high efficiency of this method in ECG compression.
Abstract: The aim of this paper is to discuss a low-cost methodology that can predict traffic flow conflicts and quantitatively rank crash expectancies (based on relative probability) for various traffic facilities. This paper focuses on the application of statistical distributions to model traffic flow and Monte Carlo techniques to simulate traffic and discusses how to create a tool in order to predict the possibility of a traffic crash. A low-cost data collection methodology has been discussed for the heterogeneous traffic flow that exists and a GIS platform has been proposed to thematically represent traffic flow from simulations and the probability of a crash. Furthermore, discussions have been made to reflect the dynamism of the model in reference to its adaptability, adequacy, economy, and efficiency to ensure adoption.
Abstract: This paper puts forward one kind of air-fuel ratio
control method with PI controller. With the help of
MATLAB/SIMULINK software, the mathematical model of air-fuel
ratio control system for distributorless CNG engine is constructed.
The objective is to maintain cylinder-to-cylinder air-fuel ratio at a
prescribed set point, determined primarily by the state of the Three-
Way-Catalyst (TWC), so that the pollutants in the exhaust are
removed with the highest efficiency. The concurrent control of airfuel
under transient conditions could be implemented by Proportional
and Integral (PI) controller. The simulation result indicates that the
control methods can easily eliminate the air/fuel maldistribution and
maintain the air/fuel ratio at the stochiometry within minimum
engine events.
Abstract: The mobile users with Laptops need to have an
efficient access to i.e. their home personal data or to the Internet from
any place in the world, regardless of their location or point of
attachment, especially while roaming outside the home subnet. An
efficient interpretation of packet losses problem that is encountered
from this roaming is to the centric of all aspects in this work, to be
over-highlighted. The main previous works, such as BER-systems,
Amigos, and ns-2 implementation that are considered to be in
conjunction with that problem under study are reviewed and
discussed. Their drawbacks and limitations, of stopping only at
monitoring, and not to provide an actual solution for eliminating or
even restricting these losses, are mentioned. Besides that, the
framework around which we built a Triple-R sequence as a costeffective
solution to eliminate the packet losses and bridge the gap
between subnets, an area that until now has been largely neglected, is
presented. The results show that, in addition to the high bit error rate
of wireless mobile networks, mainly the low efficiency of mobile-IP
registration procedure is a direct cause of these packet losses.
Furthermore, the output of packet losses interpretation resulted an
illustrated triangle of the registration process. This triangle should be
further researched and analyzed in our future work.
Abstract: The effect of the blade tip geometry of a high pressure
gas turbine is studied experimentally and computationally for high
speed leakage flows. For this purpose two simplified models are
constructed, one models a flat tip of the blade and the second models
a cavity tip of the blade. Experimental results are obtained from a
transonic wind tunnel to show the static pressure distribution along
the tip wall and provide flow visualization. RANS computations
were carried to provide further insight into the mean flow behavior
and to calculate the discharge coefficient which is a measure of the
flow leaking over the tip. It is shown that in both geometries of tip
the flow separates over the tip to form a separation bubble. The
bubble is higher for the cavity tip while a complete shock wave
system of oblique waves ending with a normal wave can be seen for
the flat tip. The discharge coefficient for the flat tip shows less
dependence on the pressure ratio over the blade tip than the cavity
tip. However, the discharge coefficient for the cavity tip is lower than
that of the flat tip, showing a better ability to reduce the leakage flow
and thus increase the turbine efficiency.
Abstract: Importance of environmental efficiency of electric power industry stems from high demand for energy combined with global warming concerns. It is especially essential for the world largest economies like that of the United States. The paper introduces a Data Envelopment Analysis (DEA) model of environmental efficiency using indicators of fossil fuels utilization, emissions rate, and electric power losses. Using DEA is advantageous in this situation over other approaches due to its nonparametric nature. The paper analyzes data for the period of 1990 - 2006 by comparing actual yearly levels in each dimension with the best values of partial indicators for the period. As positive factors of efficiency, tendency to the decline in emissions rates starting 2000, and in electric power losses starting 2004 may be mentioned together with increasing trend of fuel utilization starting 1999. As a result, dynamics of environmental efficiency is positive starting 2002. The main concern is the decline in fossil fuels utilization in 2006. This negative change should be reversed to comply with ecological and economic requirements.
Abstract: Energy and exergy study of air-water combined solar collector which is called dual purpose solar collector (DPSC) is investigated. The method of ε - NTU is used. Analysis is performed for triangle channels. Parameters like the air flow rate and water inlet temperature are studied. Results are shown that DPSC has better energy and exergy efficiency than single collector. In addition, the triangle passage with water inlet temperature of 60O C has shown better exergy and energy efficiency.
Abstract: The mobile systems are powered by batteries.
Reducing the system power consumption is a key to increase its
autonomy. It is known that mostly the systems are dealing with time
varying signals. Thus, we aim to achieve power efficiency by smartly
adapting the system processing activity in accordance with the input
signal local characteristics. It is done by completely rethinking the
processing chain, by adopting signal driven sampling and processing.
In this context, a signal driven filtering technique, based on the level
crossing sampling is devised. It adapts the sampling frequency and
the filter order by analysing the input signal local variations. Thus, it
correlates the processing activity with the signal variations. It leads
towards a drastic computational gain of the proposed technique
compared to the classical one.
Abstract: In this research, a biofiltration process to remove
ammonia gas from gas stream using agricultural residue biofilter
medias is studied. The experiments were conducted in laboratoryscale
biofilter. The biofilter medias were a mixture of manure
fertilizer and bagasse at various ratios i.e., 1:3, 1:5 and 1:7. The
experiments were performed for a period of 40 days. The empty bed
retention time (EBRT) is 78s. The moisture content of biofilter media
was maintained at 45-60% using water. The results showed that the
agricultural residues (manure fertilizer and bagasse) are suitable as
biofilter media for ammonia gas removal in biofiltration process.
The maximum efficiency of ammonia gas removal is observed
from the 1:5 of manure fertilizer: bagasse ratio at 89.93%. The
biofiltration is more effective at low ammonia gas concentration. In
addition, the mixture ratio of biofilter media is not a significant factor
in biofiltration operation while the most significant factor for
biofiltration operation is the inlet ammonia gas concentration.
Abstract: This article presents a performance comparison of an
interior mounted permanent magnet synchronous generator (IPMSG)
with a synchronous reluctance generator (SynRG) with the same size
for a wind application. It is found that using the same geometrical
dimensions, a SynRG can convert 74 % of the power that an IPMSG
can convert, while it has 80% of the IPMSG weight. Moreover it is
found that the efficieny for the IMPSG is 99% at rated power
compared to 98.7% for the SynRG.
Abstract: Fuzzy Load forecasting plays a paramount role in the operation and management of power systems. Accurate estimation of future power demands for various lead times facilitates the task of generating power reliably and economically. The forecasting of future loads for a relatively large lead time (months to few years) is studied here (long term load forecasting). Among the various techniques used in forecasting load, artificial intelligence techniques provide greater accuracy to the forecasts as compared to conventional techniques. Fuzzy Logic, a very robust artificial intelligent technique, is described in this paper to forecast load on long term basis. The paper gives a general algorithm to forecast long term load. The algorithm is an Extension of Short term load forecasting method to Long term load forecasting and concentrates not only on the forecast values of load but also on the errors incorporated into the forecast. Hence, by correcting the errors in the forecast, forecasts with very high accuracy have been achieved. The algorithm, in the paper, is demonstrated with the help of data collected for residential sector (LT2 (a) type load: Domestic consumers). Load, is determined for three consecutive years (from April-06 to March-09) in order to demonstrate the efficiency of the algorithm and to forecast for the next two years (from April-09 to March-11).
Abstract: Aim of this work was to compare the efficacy of two
loading methods of proteins onto polymeric nanocarriers: adsorption
and encapsulation methods. Preliminary studies of protein loading
were done using Bovine Serum Albumin (BSA) as model protein.
Nanocarriers were prepared starting from polylactic co-glycolic acid
(PLGA) polymer; production methods used are two different variants
of emulsion evaporation method. Nanoparticles obtained were
analyzed in terms of dimensions by Dynamic Light Scattering and
Loading Efficiency of BSA by Bradford Assay. Loaded
nanoparticles were then submitted to in-vitro protein dissolution test
in order to study the effect of the delivery system on the release rate
of the protein.