Abstract: We investigated oxidative DNA damage caused by
radio frequency radiation using 8-oxo-7, 8-dihydro-2'-
deoxyguanosine (8-oxodG) generated in mice tissues after exposure
to 900 MHz mobile phone radio frequency in three independent
experiments. The RF was generated by a Global System for Mobile
Communication (GSM) signal generator. The radio frequency field
was adjusted to 25 V/m. The whole body specific absorption rate
(SAR) was 1.0 W/kg. Animals were exposed to this field for 30 min
daily for 30 days. 24 h post-exposure, blood serum, brain and spleen
were removed and DNA was isolated. Enzyme-linked
immunosorbent assay (ELISA) was used to measure 8-oxodG
concentration. All animals survived the whole experimental period.
The body weight of animals did not change significantly at the end of
the experiment. No statistically significant differences observed in
the levels of oxidative stress. Our results are not in favor of the
hypothesis that 900 MHz RF induces oxidative damage.
Abstract: Researchers have been applying tional intelligence (AI/CI) methods to computer games. In this research field, further researchesare required to compare AI/CI
methods with respect to each game application. In th
our experimental result on the comparison of three evolutionary algorithms – evolution strategy, genetic algorithm, and their hybrid
applied to evolving controller agents for the CIG 2007 Simulated Car Racing competition. Our experimental result shows that, premature
convergence of solutions was observed in the case of ES, and GA outperformed ES in the last half of generations. Besides, a hybrid
which uses GA first and ES next evolved the best solution among the whole solutions being generated. This result shows the ability of GA in
globally searching promising areas in the early stage and the ability of ES in locally searching the focused area (fine-tuning solutions).
Abstract: Image Compression using Artificial Neural Networks
is a topic where research is being carried out in various directions
towards achieving a generalized and economical network.
Feedforward Networks using Back propagation Algorithm adopting
the method of steepest descent for error minimization is popular and
widely adopted and is directly applied to image compression.
Various research works are directed towards achieving quick
convergence of the network without loss of quality of the restored
image. In general the images used for compression are of different
types like dark image, high intensity image etc. When these images
are compressed using Back-propagation Network, it takes longer
time to converge. The reason for this is, the given image may
contain a number of distinct gray levels with narrow difference with
their neighborhood pixels. If the gray levels of the pixels in an image
and their neighbors are mapped in such a way that the difference in
the gray levels of the neighbors with the pixel is minimum, then
compression ratio as well as the convergence of the network can be
improved. To achieve this, a Cumulative distribution function is
estimated for the image and it is used to map the image pixels. When
the mapped image pixels are used, the Back-propagation Neural
Network yields high compression ratio as well as it converges
quickly.
Abstract: It well recognized that one feature that makes a
successful company is its ability to successfully align its business goals with its information communication technologies platform.
Enterprise Resource Planning (ERP) systems contribute to achieve better performance by integrating various business functions and
providing support for information flows. However, the technological
systems complexity is known to prevent the business users to exploit in an efficient way the Enterprise Resource Planning Systems (ERP).
This paper aims to investigate the role of training in improving the
usage of ERP systems. To this end, we have designed an instrument
survey to employees of a Norwegian multinational global provider of
technology solutions. Based on the analysis of collected data, we have delineated a training model that could be high relevance for
both researchers and practitioners as a step towards a better
understanding of ERP system implementation.
Abstract: Urban disaster risks and vulnerabilities are great problems for Turkey. The annual loss of life and property through disaster in the world-s major metropolitan areas is increasing. Urban concentrations of the poor and less-informed in environmentally fragile locations suffer the impact of disaster disproportionately. Gecekondu (squatter) developments will compound the inherent risks associated with high-density environments, in appropriate technologies, and inadequate infrastructure. On the other hand, there are many geological disadvantages such as sitting on top of active tectonic plate boundaries, and why having avalanche, flood, and landslide and drought prone areas in Turkey. However, this natural formation is inevitable; the only way to survive in such a harsh geography is to be aware of importance of these natural events and to take political and physical measures. The main aim of this research is to bring up the magnitude of natural hazard risks in Izmir built-up zone, not being taken into consideration adequately. Because the dimensions of the peril are not taken seriously enough, the natural hazard risks, which are commonly well known, are not considered important or they are being forgotten after some time passes. Within this research, the magnitude of natural hazard risks for Izmir is being presented in the scope of concrete and local researches over Izmir risky areas.
Abstract: Transport and land use are two systems that are
mutually influenced. Their interaction is a complex process
associated with continuous feedback. The paper examines the
existing land use around an under construction metro station of the
new metro network of Thessaloniki, Greece, through the use of field
investigations, around the station-s predefined location. Moreover,
except from the analytical land use recording, a sampling
questionnaire survey is addressed to several selected enterprises of
the study area. The survey aims to specify the characteristics of the
enterprises, the trip patterns of their employees and clients, as well as
the stated preferences towards the changes the new metro station is
considered to bring to the area. The interpretation of the interrelationships
among selected data from the questionnaire survey takes
place using the method of Principal Components Analysis for
Categorical Data. The followed methodology and the survey-s results
contribute to the enrichment of the relevant bibliography concerning
the way the creation of a new metro station can have an impact on the
land use pattern of an area, by examining the situation before the
operation of the station.
Abstract: Knowledge development in companies relies on
knowledge-intensive business processes, which are characterized by
a high complexity in their execution, weak structuring,
communication-oriented tasks and high decision autonomy, and often the need for creativity and innovation. A foundation of knowledge development is provided, which is based on a new conception of
knowledge and knowledge dynamics. This conception consists of a three-dimensional model of knowledge with types, kinds and qualities. Built on this knowledge conception, knowledge dynamics is
modeled with the help of general knowledge conversions between
knowledge assets. Here knowledge dynamics is understood to cover
all of acquisition, conversion, transfer, development and usage of
knowledge. Through this conception we gain a sound basis for
knowledge management and development in an enterprise. Especially
the type dimension of knowledge, which categorizes it according to
its internality and externality with respect to the human being, is crucial for enterprise knowledge management and development,
because knowledge should be made available by converting it to
more external types.
Built on this conception, a modeling approach for knowledgeintensive
business processes is introduced, be it human-driven,e-driven or task-driven processes. As an example for this approach, a model of the creative activity for the renewal planning of
a product is given.
Abstract: In this paper, the dynamics of a system of two van der Pol oscillators with delayed position and velocity is studied. We provide an approximate solution for this system using parameterexpansion method. Also, we obtain approximate values for frequencies of the system. The parameter-expansion method is more efficient than the perturbation method for this system because the method is independent of perturbation parameter assumption.
Abstract: The aim of this study was to compare the solubility of selected volatile organic compounds in water and silicon oil using the simple static headspace method. The experimental design allowed equilibrium achievement within 30 – 60 minutes. Infinite dilution activity coefficients and Henry-s law constants for various organics representing esters, ketones, alkanes, aromatics, cycloalkanes and amines were measured at 303K. The measurements were reproducible with a relative standard deviation and coefficient of variation of 1.3x10-3 and 1.3 respectively. The static determined activity coefficients using shaker flasks were reasonably comparable to those obtained using the gas liquid - chromatographic technique and those predicted using the group contribution methods mainly the UNIFAC. Silicon oil chemically known as polydimethysiloxane was found to be better absorbent for VOCs than water which quickly becomes saturated. For example the infinite dilution mole fraction based activity coefficients of hexane is 0.503 and 277 000 in silicon oil and water respectively. Thus silicon oil gives a superior factor of 550 696. Henry-s law constants and activity coefficients at infinite dilution play a significant role in the design of scrubbers for abatement of volatile organic compounds from contaminated air streams. This paper presents the phase equilibrium of volatile organic compounds in very dilute aqueous and polymeric solutions indicating the movement and fate of chemical in air and solvent. The successful comparison of the results obtained here and those obtained using other methods by the same authors and in literature, means that the results obtained here are reliable.
Abstract: Conjugate natural convection in a differentially heated
square enclosure containing a polygon shaped object is studied numerically in this article. The effect of various polygon types on the
fluid flow and thermal performance of the enclosure is addressed for
different thermal conductivities. The governing equations are modeled
and solved numerically using the built-in finite element method of COMSOL software. It is found that the heat transfer rate remains
stable by varying the polygon types.
Abstract: Concrete strength evaluated from compression tests
on cores is affected by several factors causing differences from the
in-situ strength at the location from which the core specimen was
extracted. Among the factors, there is the damage possibly occurring
during the drilling phase that generally leads to underestimate the
actual in-situ strength. In order to quantify this effect, in this study
two wide datasets have been examined, including: (i) about 500 core
specimens extracted from Reinforced Concrete existing structures,
and (ii) about 600 cube specimens taken during the construction of
new structures in the framework of routine acceptance control. The
two experimental datasets have been compared in terms of
compression strength and specific weight values, accounting for the
main factors affecting a concrete property, that is type and amount of
cement, aggregates' grading, type and maximum size of aggregates,
water/cement ratio, placing and curing modality, concrete age. The
results show that the magnitude of the strength reduction due to
drilling damage is strongly affected by the actual properties of
concrete, being inversely proportional to its strength. Therefore, the
application of a single value of the correction coefficient, as generally
suggested in the technical literature and in structural codes, appears
inappropriate. A set of values of the drilling damage coefficient is
suggested as a function of the strength obtained from compressive
tests on cores.
Abstract: Let X be a connected space, X be a space, let p : X -→ X be a continuous map and let (X, p) be a covering space of X. In the first section we give some preliminaries from covering spaces and their automorphism groups. In the second section we derive some algebraic properties of both universal and regular covering spaces (X, p) of X and also their automorphism groups A(X, p).
Abstract: Nigerian bread is baked with vitamin A fortified wheat flour. Study aimed at determining its contribution to preschoolers- vitamin A nutriture. A cross-sectional/experimental study was carried out in four poor-urban Local Government Areas (LGAs) of Metropolitan Lagos, Nigeria. A pretested food frequency questionnaire was administered to randomly selected mothers of 1600 preschoolers (24-59 months). Retinyl Palmitate content of fourteen bread samples randomly collected from bakeries in all LGAs was analyzed at 0 and 5 days at 25oC using High Performance Liquid Chromatography. Data analysis was done at p
Abstract: This paper analytically investigates the 3D flow
pattern at the confluences of two rectangular channels having 900
angles using Navier-Stokes equations based on Reynolds Stress
Turbulence Model (RSM). The equations are solved by the Finite-
Volume Method (FVM) and the flow is analyzed in terms of steadystate
(single-phased) conditions. The Shumate experimental findings
were used to test the validity of data. Comparison of the simulation
model with the experimental ones indicated a close proximity
between the flow patterns of the two sets. Effects of the discharge
ratio on separation zone dimensions created in the main-channel
downstream of the confluence indicated an inverse relation, where a
decrease in discharge ratio, will entail an increase in the length and
width of the separation zone. The study also found the model as a
powerful analytical tool in the feasibility study of hydraulic
engineering projects.
Abstract: The highly nonlinear characteristics of drying
processes have prompted researchers to seek new nonlinear control
solutions. However, the relation between the implementation
complexity, on-line processing complexity, reliability control
structure and controller-s performance is not well established. The
present paper proposes high performance nonlinear fuzzy controllers
for a real-time operation of a drying machine, being developed under
a consistent match between those issues. A PCI-6025E data
acquisition device from National Instruments® was used, and the
control system was fully designed with MATLAB® / SIMULINK
language. Drying parameters, namely relative humidity and
temperature, were controlled through MIMOs Hybrid Bang-bang+PI
(BPI) and Four-dimensional Fuzzy Logic (FLC) real-time-based
controllers to perform drying tests on biological materials. The
performance of the drying strategies was compared through several
criteria, which are reported without controllers- retuning. Controllers-
performance analysis has showed much better performance of FLC
than BPI controller. The absolute errors were lower than 8,85 % for
Fuzzy Logic Controller, about three times lower than the
experimental results with BPI control.
Abstract: This paper presents an optimized methodology to
folded cascode operational transconductance amplifier (OTA) design.
The design is done in different regions of operation, weak inversion,
strong inversion and moderate inversion using the gm/ID methodology
in order to optimize MOS transistor sizing.
Using 0.35μm CMOS process, the designed folded cascode OTA
achieves a DC gain of 77.5dB and a unity-gain frequency of 430MHz
in strong inversion mode. In moderate inversion mode, it has a 92dB
DC gain and provides a gain bandwidth product of around 69MHz.
The OTA circuit has a DC gain of 75.5dB and unity-gain frequency
limited to 19.14MHZ in weak inversion region.
Abstract: Secure electronic payment system is presented in this
paper. This electronic payment system is to be secure for clients such
as customers and shop owners. The security architecture of the
system is designed by RC5 encryption / decryption algorithm. This
eliminates the fraud that occurs today with stolen credit card
numbers. The symmetric key cryptosystem RC5 can protect
conventional transaction data such as account numbers, amount and
other information. This process can be done electronically using RC5
encryption / decryption program written by Microsoft Visual Basic
6.0. There is no danger of any data sent within the system being
intercepted, and replaced. The alternative is to use the existing
network, and to encrypt all data transmissions. The system with
encryption is acceptably secure, but that the level of encryption has
to be stepped up, as computing power increases. Results In order to
be secure the system the communication between modules is
encrypted using symmetric key cryptosystem RC5. The system will
use simple user name, password, user ID, user type and cipher
authentication mechanism for identification, when the user first
enters the system. It is the most common method of authentication in
most computer system.
Abstract: In this study, a synthetic pathway was created by
assembling genes from Clostridium butyricum and Escherichia coli
in different combinations. Among the genes were dhaB1 and dhaB2
from C. butyricum VPI1718 coding for glycerol dehydratase (GDHt)
and its activator (GDHtAc), respectively, involved in the conversion
of glycerol to 3-hydroxypropionaldehyde (3-HPA). The yqhD gene
from E.coli BL21 was also included which codes for an NADPHdependent
1,3-propanediol oxidoreductase isoenzyme (PDORI)
reducing 3-HPA to 1,3-propanediol (1,3-PD). Molecular modeling
analysis indicated that the conformation of fusion protein of YQHD
and DHAB1 was favorable for direct molecular channeling of the
intermediate 3-HPA. According to the simulation results, the yqhD
and dhaB1 gene were assembled in the upstream of dhaB2 to express
a fusion protein, yielding the recombinant strain E. coliBL21
(DE3)//pET22b+::yqhD-dhaB1_dhaB2 (strain BP41Y3). Strain
BP41Y3 gave 10-fold higher 1,3-PD concentration than E. coliBL21
(DE3)//pET22b+::yqhD-dhaB1_dhaB2 (strain BP31Y2) expressing
the recombinant enzymes simultaneously but in a non-fusion mode.
This is the first report using a gene fusion approach to enhance the
biological conversion of glycerol to the value added compound 1,3-
PD.
Abstract: This questionnaire-based study, aimed to measure and
compare the awareness of English reading strategies among EFL
learners at Bangkok University (BU) classified by their gender, field
of study, and English learning experience. Proportional stratified
random sampling was employed to formulate a sample of 380 BU
students. The data were statistically analyzed in terms of the mean
and standard deviation. t-Test analysis was used to find differences in
awareness of reading strategies between two groups (-male and
female- /-science and social-science students). In addition, one-way
analysis of variance (ANOVA) was used to compare reading strategy
awareness among BU students with different lengths of English
learning experience. The results of this study indicated that the
overall awareness of reading strategies of EFL learners at BU was at
a high level (ðÑ = 3.60) and that there was no statistically significant
difference between males and females, and among students who have
different lengths of English learning experience at the significance
level of 0.05. However, significant differences among students
coming from different fields of study were found at the same level of
significance.
Abstract: “Web of Trust" is one of the recognized goals for
Web 2.0. It aims to make it possible for the people to take
responsibility for what they publish on the web, including
organizations, businesses and individual users. These objectives,
among others, drive most of the technologies and protocols recently
standardized by the governing bodies. One of the great advantages of
Web infrastructure is decentralization of publication. The primary
motivation behind Web 2.0 is to assist the people to add contents for
Collective Intelligence (CI) while providing mechanisms to link
content with people for evaluations and accountability of
information. Such structure of contents will interconnect users and
contents so that users can use contents to find participants and vice
versa. This paper proposes conceptual information storage and
linking model, based on decentralized information structure, that
links contents and people together. The model uses FOAF, Atom,
RDF and RDFS and can be used as a blueprint to develop Web 2.0
applications for any e-domain. However, primary target for this
paper is online trust evaluation domain. The proposed model targets
to assist the individuals to establish “Web of Trust" in online trust
domain.