Abstract: A Picard-Newton iteration method is studied to accelerate the numerical solution procedure of a class of two-dimensional nonlinear coupled parabolic-hyperbolic system. The Picard-Newton iteration is designed by adding higher-order terms of small quantity to an existing Picard iteration. The discrete functional analysis and inductive hypothesis reasoning techniques are used to overcome difficulties coming from nonlinearity and coupling, and theoretical analysis is made for the convergence and approximation properties of the iteration scheme. The Picard-Newton iteration has a quadratic convergent ratio, and its solution has second order spatial approximation and first order temporal approximation to the exact solution of the original problem. Numerical tests verify the results of the theoretical analysis, and show the Picard-Newton iteration is more efficient than the Picard iteration.
Abstract: Nowadays, a passenger car suspension must has high
performance criteria with light weight, low cost, and low energy
consumption. Pilot controlled proportional valve is designed and
analyzed to get small pressure change rate after blow-off, and to get a
fast response of the damper, a reverse damping mechanism is adapted.
The reverse continuous variable damper is designed as a HS-SH
damper which offers good body control with reduced transferred input
force from the tire, compared with any other type of suspension
system. The damper structure is designed, so that rebound and
compression damping forces can be tuned independently, of which the
variable valve is placed externally. The rate of pressure change with
respect to the flow rate after blow-off becomes smooth when the fixed
orifice size increases, which means that the blow-off slope is
controllable using the fixed orifice size. Damping forces are measured
with the change of the solenoid current at the different piston
velocities to confirm the maximum hysteresis of 20 N, linearity, and
variance of damping force. The damping force variance is wide and
continuous, and is controlled by the spool opening, of which scheme is
usually adapted in proportional valves. The reverse continuous
variable damper developed in this study is expected to be utilized in
the semi-active suspension systems in passenger cars after its
performance and simplicity of the design is confirmed through a real
car test.
Abstract: In the last few years, several steps were taken in order
to improve the quality of corporate governance for Romanian listed
companies. Higher standards of corporate governance is documented
in the literature to lead to a better information environment, and,
consequently, to increase analysts forecast accuracy. Accordingly, the
purpose of this paper is to investigate the extent to which corporate
governance policies affect analysts forecasts for companies listed on
Bucharest Stock Exchange. The results showed that there is indeed a
negative correlation between a corporate governance index – used as
a proxy for the quality of corporate governance practices - and
analysts forecast errors.
Abstract: Fecal sterol has been proposed as a chemical indicator
of human fecal pollution even when fecal coliform populations have
diminished due to water chlorination or toxic effects of industrial
effluents. This paper describes an improved derivatization procedure
for simultaneous determination of four fecal sterols including
coprostanol, epicholestanol, cholesterol and cholestanol using gas
chromatography-mass spectrometry (GC-MS), via optimization study
on silylation procedures using N-O-bis
(trimethylsilyl)-trifluoroacetamide (BSTFA), and
N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide
(MTBSTFA), which lead to the formation of trimethylsilyl (TMS) and
tert-butyldimethylsilyl (TBS) derivatives, respectively. Two
derivatization processes of injection-port derivatization and water bath
derivatization (60 oC, 1h) were inspected and compared. Furthermore,
the methylation procedure at 25 oC for 2h with
trimethylsilydiazomethane (TMSD) for fecal sterols analysis was also
studied. It was found that most of TMS derivatives demonstrated the
highest sensitivities, followed by methylated derivatives. For BSTFA
or MTBSTFA derivatization processes, the simple injection-port
derivatization process could achieve the same efficiency as that in the
tedious water bath derivatization procedure.
Abstract: Three similar negative differential resistance (NDR)
profiles with both high peak to valley current density ratio (PVCDR)
value and high peak current density (PCD) value in unity resonant
tunneling electronic circuit (RTEC) element is developed in this paper.
The PCD values and valley current density (VCD) values of the three
NDR curves are all about 3.5 A and 0.8 A, respectively. All PV values
of NDR curves are 0.40 V, 0.82 V, and 1.35 V, respectively. The VV
values are 0.61 V, 1.07 V, and 1.69 V, respectively. All PVCDR
values reach about 4.4 in three NDR curves. The PCD value of 3.5 A
in triple PVCDR RTEC element is better than other resonant
tunneling devices (RTD) elements. The high PVCDR value is
concluded the lower VCD value about 0.8 A. The low VCD value is
achieved by suitable selection of resistors in triple PVCDR RTEC
element. The low PV value less than 1.35 V possesses low power
dispersion in triple PVCDR RTEC element. The designed multiple
value logical level (MVLL) system using triple PVCDR RTEC
element provides equidistant logical level. The logical levels of
MVLL system are about 0.2 V, 0.8 V, 1.5 V, and 2.2 V from low
voltage to high voltage and then 2.2 V, 1.3 V, 0.8 V, and 0.2 V from
high voltage back to low voltage in half cycle of sinusoid wave. The
output level of four levels MVLL system is represented in 0.3 V, 1.1 V,
1.7 V, and 2.6 V, which satisfies the NMP condition of traditional
two-bit system. The remarkable logical characteristic of improved
MVLL system with paralleled capacitor are with four significant
stable logical levels about 220 mV, 223 mV, 228 mV, and 230 mV.
The stability and articulation of logical levels of improved MVLL
system are outstanding. The average holding time of improved MVLL
system is approximately 0.14 μs. The holding time of improved
MVLL system is fourfold than of basic MVLL system. The function of
additional capacitor in the improved MVLL system is successfully
discovered.
Abstract: For the past thirty years the Malaysian economy has been said to contribute well to the progress of the nations. However, the intensification of global economy activity and the extensive use of Information Communication Technologies (ICTs) in recent years are challenging government-s effort to further develop Malaysian society. The competition posed by the low wage economies such as China and Vietnam have made the government realise the importance of engaging in high-skill and high technology industries. It is hoped this will be the basis of attracting more foreign direct investment (FDI) in order to help the country to compete in globalised world. Using Vision 2020 as it targeted vision, the government has decided to engage in the use of ICTs and introduce many policies pertaining to it. Mainly based on the secondary analysis approach, the findings show that policy pertaining to ICTs in Malaysia contributes to economic growth, but the consequences of this have resulted in greater division within society. Although some of the divisions such as gender and ethnicity are narrowing down, the gap in important areas such as regions and class differences is becoming wider. The widespread use of ICTs might contribute to the further establishment of democracy in Malaysia, but the increasing number of foreign entities such as FDI and foreign workers, cultural hybridisation and to some extent cultural domination are contributing to neocolonialism in Malaysia. This has obvious consequences for the government-s effort to create a Malaysian national identity. An important finding of this work is that there are contradictions within ICT policy between the effort to develop the economy and society.
Abstract: Ethanol has become more attractive in fuel industry
either as fuel itself or an additive that helps enhancing the octane
number and combustibility of gasoline. This research studied a
pressure swing adsorption using cassava-based adsorbent prepared
from mixture of cassava starch and cassava pulp for dehydration of
ethanol vapor. The apparatus used in the experiments consisted of
double adsorption columns, an evaporator, and a vacuum pump. The
feed solution contained 90-92 %wt of ethanol. Three process
variables: adsorption temperatures (110, 120 and 130°C), adsorption
pressures (1 and 2 bar gauge) and feed vapor flow rate (25, 50 and 75
% valve opening of the evaporator) were investigated. According to
the experimental results, the optimal operating condition for this
system was found to be at 2 bar gauge for adsorption pressure, 120°C
for adsorption temperature and 25% valve opening of the evaporator.
Production of 1.48 grams of ethanol with concentration higher than
99.5 wt% per gram of adsorbent was obtained. PSA with cassavabased
adsorbent reported in this study could be an alternative method
for production of nearly anhydrous ethanol. Dehydration of ethanol
vapor achieved in this study is due to an interaction between free
hydroxyl group on the glucose units of the starch and the water
molecules.
Abstract: Assessment for image quality traditionally needs its
original image as a reference. The conventional method for assessment
like Mean Square Error (MSE) or Peak Signal to Noise Ratio (PSNR)
is invalid when there is no reference. In this paper, we present a new
No-Reference (NR) assessment of image quality using blur and noise.
The recent camera applications provide high quality images by help of
digital Image Signal Processor (ISP). Since the images taken by the
high performance of digital camera have few blocking and ringing
artifacts, we only focus on the blur and noise for predicting the
objective image quality. The experimental results show that the
proposed assessment method gives high correlation with subjective
Difference Mean Opinion Score (DMOS). Furthermore, the proposed
method provides very low computational load in spatial domain and
similar extraction of characteristics to human perceptional assessment.
Abstract: Supplier appraisal fosters energy in Supply Chain
Management and helps in best optimization of viable business
partners for a company. Many Decision Making techniques have
already been proposed by researchers for supplier-s appraisal.
However, Analytic Hierarchy Process (AHP) is assumed to be the
most structured technique to attain near-best solution of the problem.
This paper focuses at implementation of AHP in the procurement
processes. It also suggests that on what factors a Public Sector
Enterprises must focus while dealing with their suppliers and what
should the suppliers do to synchronize their activities with the
strategic objectives of Organization. It also highlights the weak areas
in supplier appraisal process with a view to suggest viable
recommendations.
Abstract: This paper compares the recent transformerless ACDC
power converter architectures and provides an assessment of
each. A prototype of one of the transformerless AC-DC converter
architecture is also presented depicting the feasibility of a small form
factor, power supply design. In this paper component selection
guidelines to achieve high efficiency AC-DC power conversion are
also discussed.
Abstract: In a chirp spread spectrum (CSS) system, the overlap
technique is used for increasing bit rate. More overlaps can offer
higher data throughput; however, they may cause more intersymbol
interference (ISI) at the same time, resulting in serious bit error
rate (BER) performance degradation. In this paper, we perform the
BER analysis and derive a closed form BER expression for the
overlap-based CSS system. The derived BER expression includes
the number of overlaps as a parameter, and thus, would be very
useful in determining the number of overlaps for a specified BER.
The numerical results demonstrate that the BER derived in a closed
form closely agrees with the simulated BER.
Abstract: The purpose of this study is to investigate the
relationship between corporate governance and pricing for initial
public offerings (IPOs). Empirical result finds that the prediction of
pricing of IPOs with corporate governance added can have a rather
higher degree of predicting accuracy than that of non governance
added during the training and testing samples. Therefore, it can be
observed that corporate governance mechanism can affect the pricing
of IPOs
Abstract: In multi hop wireless systems, such as ad hoc and
sensor networks, mobile ad hoc network applications are deployed,
security emerges as a central requirement. A particularly devastating
attack is known as the wormhole attack, where two or more malicious
colluding nodes create a higher level virtual tunnel in the network,
which is employed to transport packets between the tunnel end points.
These tunnels emulate shorter links in the network. In which
adversary records transmitted packets at one location in the network,
tunnels them to another location, and retransmits them into the
network. The wormhole attack is possible even if the attacker has not
compromised any hosts and even if all communication provides
authenticity and confidentiality. In this paper, we analyze wormhole
attack nature in ad hoc and sensor networks and existing methods of
the defending mechanism to detect wormhole attacks without require
any specialized hardware. This analysis able to provide in
establishing a method to reduce the rate of refresh time and the
response time to become more faster.
Abstract: Staphylococcus aureus, one of the microflora in a
human external auditory canal (EAC) is frequently exposed to highfrequency
electromagnetic field (HF-EMF) generated by mobile
phones. It is normally non-pathogenic but in certain circumstances, it
can cause infections. This study investigates the changes in the
physiology of S. aureus when exposed to HF-EMF of a mobile
phone. Exponentially grown S. aureus were exposed to two
conditions of EMF irradiation (standby-mode and on-call mode) at
four durations; 15, 30, 45 and 60 min. Changes in the viability and
biofilm production of the S. aureus were compared between the two
conditions of exposure. EMF from the standby-mode has enhanced
the growth of S. aureus but during on-call, the growth was
suppressed. No significant difference in the amount of biofilm
produced in both modes of exposure was observed. Thus, HF-EMF
of mobile phone affects the viability of S. aureus but not its ability to
produce biofilm.
Abstract: Micro power sources are required to be used in autonomous microelectromechanical system (MEMS). In this paper,
we designed and fabricated a three dimensional (3D) MEMS supercapacitor, which is consisting of conformal silicon
dioxide/titanium/polypyrrole (PPy) layers on silicon substrate. At first, ''through-structure'' was fabricated on the silicon substrate by high-aspect-ratio deep reactive ion etching (DRIE) method, which enlarges the available surface area significantly. Then the SiO2/Ti/PPy layers grew sequentially on the ³through-structure´. Finally, the supercapacitor was investigated by electrochemical methods.
Abstract: An application framework provides a reusable design
and implementation for a family of software systems. Application
developers extend the framework to build their particular
applications using hooks. Hooks are the places identified to show
how to use and customize the framework. Hooks define the
Framework Interface Classes (FICs) and their possible specifications,
which helps in building reusable test cases for the implementations of
these classes. This paper introduces a novel technique called all
paths-state to generate state-based test cases to test the FICs at class
level. The technique is experimentally evaluated. The empirical
evaluation shows that all paths-state technique produces test cases
with a high degree of coverage for the specifications of the
implemented FICs comparing to test cases generated using round-trip
path and all-transition techniques.
Abstract: Medical services are usually provided in hospitals; however, in developing country, some rural residences have fewer opportunities to access in healthcare services due to the limitation of transportation communication. Therefore, in Thailand, there are charitable organizations operating to provide medical treatments to these people by shifting the medical services to operation sites; this is commonly known as mobile medical service. Operation routing is important for the organization to reduce its transportation cost in order to focus more on other important activities; for instance, the development of medical apparatus. VRP is applied to solve the problem of high transportation cost of the studied organization with the searching techniques of saving algorithm to find the minimum total distance of operation route and satisfy available time constraints of voluntary medical staffs.
Abstract: The important issue considered in the widespread deployment of Wireless Sensor Networks (WSNs) is an efficiency of the energy consumption. In this paper, we present a study of the optimal relay station planning problems using Binary Integer Linear Programming (BILP) model to minimize the energy consumption in WSNs. Our key contribution is that the proposed model not only ensures the required network lifetime but also guarantees the radio connectivity at high level of communication quality. Specially, we take into account effects of noise, signal quality limitation and bit error rate characteristics. Numerical experiments were conducted in various network scenarios. We analyzed the effects of different sensor node densities and distribution on the energy consumption.
Abstract: Liquid-liquid extraction is a process using two immiscible
liquids to extract compounds from one phase without high
temperature requirement. Mostly, the technical implementation of
this process is carried out in mixer-settlers or extraction columns. In
real chemical processes, chemicals may have high viscosity and
contain impurities. These impurities may change the settling behavior
of the process without measurably changing the physical properties
of the phases. In the current study, the settling behavior and the affected
parameters in a high-viscosity system were observed. Batchsettling
experiments were performed to experimentally quantify the
settling behavior and the mixer-settler model of Henschke [1] was
used to evaluate the behavior of the toluene + water system. The
viscosity of the system was increased by adding polyethylene glycol
4000 to the aqueous phase. NaCl and Na2SO4 were used to study the
influence of electrolytes. The results from this study show that increasing
the viscosity of water has a higher influence on the settling
behavior in comparison to the effects of the electrolytes. It can be
seen from the experiments that at high salt concentrations, there was
no effect on the settling behavior.
Abstract: This research paper designs a unique motion planner
of multiple platoons of nonholonomic car-like robots as a feasible
solution to the lane changing/merging maneuvers. The decentralized
planner with a leaderless approach and a path-guidance principle
derived from the Lyapunov-based control scheme generates collision
free avoidance and safe merging maneuvers from multiple lanes to a
single lane by deploying a split/merge strategy. The fixed obstacles
are the markings and boundaries of the road lanes, while the moving
obstacles are the robots themselves. Real and virtual road lane
markings and the boundaries of road lanes are incorporated into a
workspace to achieve the desired formation and configuration of the
robots. Convergence of the robots to goal configurations and the
repulsion of the robots from specified obstacles are achieved by
suitable attractive and repulsive potential field functions,
respectively. The results can be viewed as a significant contribution
to the avoidance algorithm of the intelligent vehicle systems (IVS).
Computer simulations highlight the effectiveness of the split/merge
strategy and the acceleration-based controllers.