Abstract: Automatic tube current modulation (ATCM) systems are available for all CT manufacturers and are used for the majority of patients. Understanding how the systems work and their influence on patient dose and image quality is important for CT users, in order to gain the most effective use of the systems. In the present study, a new phantom was used for evaluating dose distribution and image quality under the ATCM operation for the Toshiba Aquilion 64 CT scanner using different ATCM options and a fixed mAs technique. A routine chest, abdomen and pelvis (CAP) protocol was selected for study and Gafchromic film was used to measure entrance surface dose (ESD), peripheral dose and central axis dose in the phantom. The results show the dose reductions achievable with various ATCM options, in relation with the target noise. The doses and image noise distribution were more uniform when the ATCM system was implemented compared with the fixed mAs technique. The lower limit set for the tube current will affect the modulations especially for the lower dose option. This limit prevented the tube current being reduced further and therefore the lower dose ATCM setting resembled a fixed mAs technique. Selection of a lower tube current limit is likely to reduce doses for smaller patients in scans of chest and neck regions.
Abstract: The approaches to make an agent generate intelligent actions in the AI field might be roughly categorized into two ways–the classical planning and situated action system. It is well known that each system have its own strength and weakness. However, each system also has its own application field. In particular, most of situated action systems do not directly deal with the logical problem. This paper first briefly mentions the novel action generator to situatedly extract a set of actions, which is likely to help to achieve the goal at the current situation in the relaxed logical space. After performing the action set, the agent should recognize the situation for deciding the next likely action set. However, since the extracted action is an approximation of the action which helps to achieve the goal, the agent could be caught into the deadlock of the problem. This paper proposes the newly developed hybrid architecture to solve the problem, which combines the novel situated action generator with the conventional planner. The empirical result in some planning domains shows that the quality of the resultant path to the goal is mostly acceptable as well as deriving the fast response time, and suggests the correlation between the structure of problems and the organization of each system which generates the action.
Abstract: Potassium monopersulfate has been decomposed in aqueous solution in the presence of Co(II). The process has been simulated by means of a mechanism based on elementary reactions. Rate constants have been taken from literature reports or, alternatively, assimilated to analogous reactions occurring in Fenton's chemistry. Several operating conditions have been successfully applied.
Abstract: The Continuously Adaptive Mean-Shift (CamShift)
algorithm, incorporating scene depth information is combined with
the l1-minimization sparse representation based method to form a
hybrid kernel and state space-based tracking algorithm. We take
advantage of the increased efficiency of the former with the
robustness to occlusion property of the latter. A simple interchange
scheme transfers control between algorithms based upon drift and
occlusion likelihood. It is quantified by the projection of target
candidates onto a depth map of the 2D scene obtained with a low cost
stereo vision webcam. Results are improved tracking in terms of drift
over each algorithm individually, in a challenging practical outdoor
multiple occlusion test case.
Abstract: In this study, the forty Thai medicinal plants were
used to screen the antibacterial activity against Campylobacter jejuni.
Crude 95% ethanolic extracts of each plant were prepared.
Antibacterial activity was investigated by the disc diffusion assay,
and MICs and MBCs were determined by broth microdilution. The
results of antibacterial screening showed that five plants have activity
against C.jejuni including Adenanthera pavonina L., Moringa
oleifera Lam., Annona squamosa L., Hibiscus sabdariffa L. and
Eupotorium odortum L. The extraction of A. pavonina L. and A.
squamosa L. produced an outstanding against C. jejuni, inhibiting
growth at 62.5-125 and 250-500 μg/mL, respectively. The MBCs of
two extracts were just 4-fold higher than MICs against C. jejuni,
suggesting the extracts are bactericidal against this species. These
results indicate that A. pavonina and A. squamosa could potentially
be used in modern applications aimed at treatment or prevention of
foodborne disease from C. jejuni.
Abstract: Culinary culture differences can cause health
problems for international tourists in Thailand. This paper drew upon
data collected from an international tourist survey conducted in
Bangkok, Thailand during summer of 2012. Summer is the period
that a variety food safety issues and incidents are often publicized in
Thailand. The survey targeted European Union tourists- concerns
toward a variety of food safety issues that they encountered during
their trip in Thailand. A total of 400 respondents were elicited as data
input for t-test, and one way ANOVA test. The findings revealed an
astonishing result that up to 46.5 percent of respondents were sick at
least one time or more in Thailand. However, the majority of
respondents trusted that the Thai hotel and Thai restaurants would
ensure food safety, but they did not trust street vendors to ensure food
safety. The level of food safety concern can be ranked from most
concern to least concern by using the value of mean scores as
follows: 1) artificial coloring, 2) use of preservatives, 3) antibiotics,
4) growth hormones, 5) chemical residues, and 6) bacterial
contamination. The overall mean score for level of concerns was
3.493 with standard deviation of 1.677 which did not indicate a very
high level of concern. In addition, the result for t-test and one way
ANOVA test revealed that there was not much effect from the
demographic differences to level of food safety concerns.
Abstract: This paper presents the mathematical model and
control strategy on DQ frame of shunt active power filter. The
structure of the shunt active power filter is the voltage source inverter
(VSI). The pulse width modulation (PWM) with PI controller is used
in the paper. The concept of DQ frame to apply with the shunt active
power filter is described. Moreover, the detail of the PI controller
design for two current loops and one voltage loop are fully explained.
The DQ axis with Fourier (DQF) method is applied to calculate the
reference currents on DQ frame. The simulation results show that the
control strategy and the design method presented in the paper can
provide the good performance of the shunt active power filter.
Moreover, the %THD of the source currents after compensation can
follow the IEEE Std.519-1992.
Abstract: Nowadays companies in all sectors are looking for the
sources of competitive advantages. Holistic marketing approach
searches for their emergence based on the integration of all
components and elements across the organization. Modern marketing
sees the sources of competitive advantage in implementing the latest
managerial practices, motivation, intelligent project management,
knowledge management, collaborative marketing, CSR and, in the
recent years, also in the business process optimization. With the use
of modern tools including business process management and business
process modelling the company can markedly increase its internal
efficiency which can lead not only to lowering the costs but to
creating the environment for optimal customer care, positive
corporate culture and for origination of innovations as well. In the
article the authors analyze the recent trend in this area and introduce
suggestions to companies to identify and optimize the key processes
that have a significant impact of the company´s competitiveness.
Abstract: The purpose of this research is to increase our
knowledge as regards how Small-and-Medium-Sized Enterprises
(SMEs) tackle ERP implementation projects to achieve successful
adoption and use of these systems within the organization. SMEs
have scare resources to handle these kinds of projects which have
proved to be risky and costly. There are several studies focusing on
ERP implementation in larger companies, however, few studies
report on challenges experienced by SMEs. Our research seeks to
bridge this gap. Through a multiple case study of four companies, we
identified challenges and critical elements within the different phases
(pre-implementation, implementation and post-implementation) of
the ERP life cycle. To interpret our findings, we utilize a well-know
ERP life cycle model and critical success factors developed for larger
companies which are reported in former research literature. We
discuss if these models are relevant for SMEs and suggest additional
critical elements identified in this study to make a framework more
adapted to the SME context.
Abstract: The importance of our country-s communication
system is noticeable when a disaster occurs. The communication
system in our country includes wired and wireless telephone
networks, radio, satellite system and more increasingly internet. Even
though our communication system is most extensive and dependable,
extreme conditions can put a strain on them. Interoperability between
heterogeneous wireless networks can be used to provide efficient
communication for emergency first response. IEEE 802.21 specifies
Media Independent Handover (MIH) services to enhance the mobile
user experience by optimizing handovers between heterogeneous
access networks. This paper presents an algorithm to improve
congestion control in MIH framework. It is analytically shown that
by including time factor in network selection we can optimize
congestion in the network.
Abstract: This study aimed at developing a forecasting model on the number of Dengue Haemorrhagic Fever (DHF) incidence in Northern Thailand using time series analysis. We developed Seasonal Autoregressive Integrated Moving Average (SARIMA) models on the data collected between 2003-2006 and then validated the models using the data collected between January-September 2007. The results showed that the regressive forecast curves were consistent with the pattern of actual values. The most suitable model was the SARIMA(2,0,1)(0,2,0)12 model with a Akaike Information Criterion (AIC) of 12.2931 and a Mean Absolute Percent Error (MAPE) of 8.91713. The SARIMA(2,0,1)(0,2,0)12 model fitting was adequate for the data with the Portmanteau statistic Q20 = 8.98644 ( x20,95= 27.5871, P>0.05). This indicated that there was no significant autocorrelation between residuals at different lag times in the SARIMA(2,0,1)(0,2,0)12 model.
Abstract: The present work deals with analyses of the effects
of bearing curvature and non-Newtonian characteristics on the load capacity of an exponential rectangular squeeze film bearing using
Bingham fluids as lubricants. Bingham fluids are characterized by an
yield value and hence the formation of a “rigid" core in the region
between the plates is justified. The flow is confined to the region
between the core and the plates. The shape of the core has been
identified through numerical means. Further, numerical solutions for
the pressure distribution and load carrying capacity of the bearing
for various values of Bingham number and curvature parameter have
been obtained. The effects of bearing curvature and non-Newtonian
characteristics of the lubricant on the bearing performances have been
discussed.
Abstract: In today-s highly globalised and competitive world
access to information plays key role in having an upper hand between
business rivals. Hence, proper protection of such crucial resource is
core to any modern business. Implementing a successful information
security system is basically centered around three pillars; technical
solution involving both software and hardware, information security
controls to translate the policies and procedure in the system and the
people to implement. This paper shows that a lot needs to be done for
countries adapting information technology to process, store and
distribute information to secure adequately such core resource.
Abstract: The aim of this study is to discover secondary school students’ perceptions related to information technologies and the connections between concepts in their cognitive structures. A word association test consisting of six concepts related to information technologies is used to collect data from 244 secondary school students. Concept maps that present students’ cognitive structures are drawn with the help of frequency data. Data are analyzed and interpreted according to the connections obtained as a result of the concept maps. It is determined students associate most with these concepts—computer, Internet, and communication of the given concepts, and associate least with these concepts—computer-assisted education and information technologies. These results show the concepts, Internet, communication, and computer, are an important part of students’ cognitive structures. In addition, students mostly answer computer, phone, game, Internet and Facebook as the key concepts. These answers show students regard information technologies as a means for entertainment and free time activity, not as a means for education.
Abstract: Distributed Power generation has gained a lot of
attention in recent times due to constraints associated with
conventional power generation and new advancements in DG
technologies .The need to operate the power system economically
and with optimum levels of reliability has further led to an increase
in interest in Distributed Generation. However it is important to place
Distributed Generator on an optimum location so that the purpose of
loss minimization and voltage regulation is dully served on the
feeder. This paper investigates the impact of DG units installation on
electric losses, reliability and voltage profile of distribution networks.
In this paper, our aim would be to find optimal distributed
generation allocation for loss reduction subjected to constraint of
voltage regulation in distribution network. The system is further
analyzed for increased levels of Reliability. Distributed Generator
offers the additional advantage of increase in reliability levels as
suggested by the improvements in various reliability indices such as
SAIDI, CAIDI and AENS. Comparative studies are performed and
related results are addressed. An analytical technique is used in order
to find the optimal location of Distributed Generator. The suggested
technique is programmed under MATLAB software. The results
clearly indicate that DG can reduce the electrical line loss while
simultaneously improving the reliability of the system.
Abstract: Saccharomyces cerevisiae (baker-s yeast) can exhibit
sustained oscillations during the operation in a continuous bioreactor
that adversely affects its stability and productivity. Because of
heterogeneous nature of cell populations, the cell population balance
models can be used to capture the dynamic behavior of such cultures.
In this paper an unstructured, segregated model is used which is
based on population balance equation(PBE) and then in order to
simulation, the 4th order Rung-Kutta is used for time dimension and
three methods, finite difference, orthogonal collocation on finite
elements and Galerkin finite element are used for discretization of the
cell mass domain. The results indicate that the orthogonal collocation
on finite element not only is able to predict the oscillating behavior of
the cell culture but also needs much little time for calculations.
Therefore this method is preferred in comparison with other methods.
In the next step two controllers, a globally linearizing control (GLC)
and a conventional proportional-integral (PI) controller are designed
for controlling the total cell mass per unit volume, and performances
of these controllers are compared through simulation. The results
show that although the PI controller has simpler structure, the GLC
has better performance.
Abstract: The power transformer is the most expensive, indispensable and arguably the most important equipment item in a power system Insulation failure in transformers can cause long term interruption to supply and loss of revenue and the condition assessment of the insulation is thus an important maintenance procedure. Oil-impregnated transformer insulation consists of mainly organic materials including mineral oil and cellulose-base paper and pressboard. The operating life of cellulose-based insulation, as with most organic insulation, depends heavily on its operating temperature rise above ambient. This paper reports results of a laboratory-based experimental investigation of partial discharge (PD) activity at high temperature in oil-impregnated insulation. The experiments reported here are part an on-going programme aimed at investigating the way in which insulation deterioration can be monitored and quantified by use of partial discharge diagnostics. Partial discharge patterns were recorded and analysed during increasing and decreasing phases of the temperature. The effect of ageing of the insulation on the PD patterns in oil and oil-impregnated insulation are also considered.
Abstract: To maximise furnace production it-s necessary to
optimise furnace control, with the objectives of achieving maximum
power input into the melting process, minimum network distortion
and power-off time, without compromise on quality and safety. This
can be achieved with on the one hand by an appropriate electrode
control and on the other hand by a minimum of AC transformer
switching.
Electrical arc is a stochastic process; witch is the principal cause
of power quality problems, including voltages dips, harmonic
distortion, unbalance loads and flicker. So it is difficult to make an
appropriate model for an Electrical Arc Furnace (EAF). The factors
that effect EAF operation are the melting or refining materials,
melting stage, electrode position (arc length), electrode arm control
and short circuit power of the feeder. So arc voltages, current and
power are defined as a nonlinear function of the arc length. In this
article we propose our own empirical function of the EAF and model,
for the mean stages of the melting process, thanks to the
measurements in the steel factory.
Abstract: Bone growth factors, such as Bone Morphogenic
Protein-2 (BMP-2) have been approved by the FDA to replace grafting for some surgical interventions, but the high dose requirement limits its use in patients. Noggin, an extracellular protein, blocks the effect of BMP-2 by binding to BMP. Preventing
the BMP-2/noggin interaction will help increase the free
concentration of BMP-2 and therefore should enhance its efficacy to
induce bone formation. The work presented here involves
computational design of novel small molecule inhibitory agents of BMP-2/noggin interaction, based on our current understanding of
BMP-2, and its known putative ligands (receptors and antagonists). A
successful acquisition of such an inhibitory agent of BMP-2/noggin interaction would allow clinicians to reduce the dose required of
BMP-2 protein in clinical applications to promote osteogenesis. The
available crystal structures of the BMPs, its receptors, and the binding partner noggin were analyzed to identify the critical residues
involved in their interaction. In presenting this study, LUDI de novo design method was utilized to perform virtual screening of a large
number of compounds from a commercially available library against the binding sites of noggin to identify the lead chemical compounds
that could potentially block BMP-noggin interaction with a high specificity.
Abstract: Environmental impact assessment (EIA) is a procedure tool of environmental management for identifying, predicting, evaluating and mitigating the adverse effects of development proposals. EIA reports usually analyze how the amounts or concentrations of pollutants obey the relevant standards. Actually, many analytical tools can deepen the analysis of environmental impacts in EIA reports, such as life cycle assessment (LCA) and environmental risk assessment (ERA). Life cycle impact assessment (LCIA) is one of steps in LCA to introduce the causal relationships among environmental hazards and damage. Incorporating the LCIA concept into ERA as an integrated tool for EIA can extend the focus of the regulatory compliance of environmental impacts to determine of the significance of environmental impacts. Sometimes, when using integrated tools, it is necessary to consider fuzzy situations due to insufficient information; therefore, ERA should be generalized to fuzzy risk assessment (FRA). Finally, the use of the proposed methodology is demonstrated through the study case of the expansion plan of the world-s largest plastics processing factory.