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: The purpose of this study was to analyze the correlation
between permitted building areas and housing distribution ratios and
their fluctuation, and test a distribution model during 3 successive governments in 5 cities including Bucheon in reference to the time
series administrative data, and thereby, interpret the results of the analysis in association with the policies pursued by the successive
governments to examine the structural fluctuation of permitted building areas and housing distribution ratios.
In order to analyze the fluctuation of permitted building areas and
housing distribution ratios during 3 successive governments and
examine the cycles of the time series data, the spectral analysis was performed, and in order to analyze the correlation between permitted
building areas and housing distribution ratios, the tabulation was performed to describe the correlations statistically, and in order to
explain about differences of fluctuation distribution of permitted building areas and housing distribution ratios among 3 governments,
the goodness of fit test was conducted.
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: Intermetallic Ni3Al – based alloys belong to a group
of advanced materials characterized by good chemical and physical
properties (such as structural stability, corrosion resistance) which
offer advenced technological applications. The paper presents the
study of catalytic properties of Ni3Al foils (thickness approximately
50 &m) in the methanol and hexane decomposition. The egzamined
material posses microcrystalline structure without any additional
catalysts on the surface. The better catalytic activity of Ni3Al foils
with respect to quartz plates in both methanol and hexane
decomposition was confirmed. On thin Ni3Al foils the methanol
conversion reaches approximately 100% above 480 oC while the
hexane conversion reaches approximately 100% (98,5%) at 500 oC.
Deposit formed during the methanol decomposition is built up of
carbon nanofibers decorated with metal-like nanoparticles.
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: To illustrate diversity of methods used to extract relevant (where the concept of relevance can be differently defined for different applications) visual data, the paper discusses three groups of such methods. They have been selected from a range of alternatives to highlight how hardware and software tools can be complementarily used in order to achieve various functionalities in case of different specifications of “relevant data". First, principles of gated imaging are presented (where relevance is determined by the range). The second methodology is intended for intelligent intrusion detection, while the last one is used for content-based image matching and retrieval. All methods have been developed within projects supervised by the author.
Abstract: One major issue that is regularly cited as a block to
the widespread use of online assessments in eLearning, is that of the
authentication of the student and the level of confidence that an
assessor can have that the assessment was actually completed by that
student. Currently, this issue is either ignored, in which case
confidence in the assessment and any ensuing qualification is
damaged, or else assessments are conducted at central, controlled
locations at specified times, losing the benefits of the distributed
nature of the learning programme. Particularly as we move towards
constructivist models of learning, with intentions towards achieving
heutagogic learning environments, the benefits of a properly
managed online assessment system are clear. Here we discuss some
of the approaches that could be adopted to address these issues,
looking at the use of existing security and biometric techniques,
combined with some novel behavioural elements. These approaches
offer the opportunity to validate the student on accessing an
assessment, on submission, and also during the actual production of
the assessment. These techniques are currently under development in
the DECADE project, and future work will evaluate and report their
use..
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: Voltage flicker problems have long existed in several
of the distribution areas served by the Taiwan Power Company. In
the past, those research results indicating that the estimated ΔV10
value based on the conventional method is significantly smaller than
the survey value. This paper is used to study the relationship between
the voltage flicker problems and harmonic power variation for the
power system with electric arc furnaces. This investigation discussed
thought the effect of harmonic power fluctuation with flicker
estimate value. The method of field measurement, statistics and
simulation is used. The survey results demonstrate that 10 ΔV
estimate must account for the effect of harmonic power variation.
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: Grid computing is a group of clusters connected over
high-speed networks that involves coordinating and sharing
computational power, data storage and network resources operating
across dynamic and geographically dispersed locations. Resource
management and job scheduling are critical tasks in grid computing.
Resource selection becomes challenging due to heterogeneity and
dynamic availability of resources. Job scheduling is a NP-complete
problem and different heuristics may be used to reach an optimal or
near optimal solution. This paper proposes a model for resource and
job scheduling in dynamic grid environment. The main focus is to
maximize the resource utilization and minimize processing time of
jobs. Grid resource selection strategy is based on Max Heap Tree
(MHT) that best suits for large scale application and root node of
MHT is selected for job submission. Job grouping concept is used to
maximize resource utilization for scheduling of jobs in grid
computing. Proposed resource selection model and job grouping
concept are used to enhance scalability, robustness, efficiency and
load balancing ability of the grid.
Abstract: Business continuity management (BCM) identifies
potential external and internal threats to an organization and their
impacts to business operations. The goal of the article is to identify,
based on the analysis of employee turnover in organizations in the
Czech Republic, the role of personnel planning in BCM. The article
is organized as follows. The first part of the article concentrates on
the theoretical background of the topic. The second part of the article
is dedicated to the evaluation of the outcomes of the survey
conducted (questionnaire survey), focusing on the analysis of
employee turnover in organizations in the Czech Republic. The final
part of the article underlines the role of personnel planning in BCM,
since poor planning of staff needs in an organization can represent
a future threat for business continuity ensuring.
Abstract: Nanophotocatalysts such as titanium (TiO2), zinc (ZnO), and iron (Fe2O3) oxides can be used in organic pollutants oxidation, and in many other applications. But among the challenges for technological application (scale-up) of the nanotechnology scientific developments two aspects are still little explored: research on environmental risk of the nanomaterials preparation methods, and the study of nanomaterials properties and/or performance variability. The environmental analysis was performed for six different methods of ZnO nanoparticles synthesis, and showed that it is possible to identify the more environmentally compatible process even at laboratory scale research. The obtained ZnO nanoparticles were tested as photocatalysts, and increased the degradation rate of the Rhodamine B dye up to 30 times.
Abstract: Traffic Engineering (TE) is the process of controlling
how traffic flows through a network in order to facilitate efficient and
reliable network operations while simultaneously optimizing network
resource utilization and traffic performance. TE improves the
management of data traffic within a network and provides the better
utilization of network resources. Many research works considers intra
and inter Traffic Engineering separately. But in reality one influences
the other. Hence the effective network performances of both inter and
intra Autonomous Systems (AS) are not optimized properly. To
achieve a better Joint Optimization of both Intra and Inter AS TE, we
propose a joint Optimization technique by considering intra-AS
features during inter – AS TE and vice versa. This work considers the
important criterion say latency within an AS and between ASes. and
proposes a Bi-Criteria Latency optimization model. Hence an overall
network performance can be improved by considering this jointoptimization
technique in terms of Latency.
Abstract: The aim of this article is to explain how features of attacks could be extracted from the packets. It also explains how vectors could be built and then applied to the input of any analysis stage. For analyzing, the work deploys the Feedforward-Back propagation neural network to act as misuse intrusion detection system. It uses ten types if attacks as example for training and testing the neural network. It explains how the packets are analyzed to extract features. The work shows how selecting the right features, building correct vectors and how correct identification of the training methods with nodes- number in hidden layer of any neural network affecting the accuracy of system. In addition, the work shows how to get values of optimal weights and use them to initialize the Artificial Neural Network.
Abstract: Iterative learning control aims to achieve zero tracking
error of a specific command. This is accomplished by iteratively
adjusting the command given to a feedback control system, based on
the tracking error observed in the previous iteration. One would like
the iterations to converge to zero tracking error in spite of any error
present in the model used to design the learning law. First, this need
for stability robustness is discussed, and then the need for robustness
of the property that the transients are well behaved. Methods of
producing the needed robustness to parameter variations and to
singular perturbations are presented. Then a method involving
reverse time runs is given that lets the world behavior produce the
ILC gains in such a way as to eliminate the need for a mathematical
model. Since the real world is producing the gains, there is no issue
of model error. Provided the world behaves linearly, the approach
gives an ILC law with both stability robustness and good transient
robustness, without the need to generate a model.
Abstract: The research object was wheat bread. Experiments
were carried out at the Faculty of Food Technology of the Latvia
University of Agriculture. An active packaging in combination with
modified atmosphere (MAP, CO2 60% and N2 40%) was examined
and compared with traditional packaging in air ambiance. Polymer
Multibarrier 60, PP and OPP bags were used. Influence of iron based
oxygen absorber in sachets of 100 cc obtained from Mitsubishi Gas
Chemical Europe Ageless® was tested on the quality during the shelf
of wheat bread. Samples of 40±4 g were packaged in polymer
pouches (110 mm x 120 mm), hermetically sealed by MULTIVAC
C300 vacuum chamber machine, and stored in room temperature
+21.0±0.5 °C. The physiochemical properties – weight losses,
moisture content, hardness, pH, colour, changes of atmosphere
content (CO2 and O2) in headspace of packs, and microbial
conditions were analysed before packaging and in the 7th, 14th, 21st
and 28th days of storage.
Abstract: The aim of the present work is to study the effect of annealing on the vibration damping capacity of high-chromium (16%) ferromagnetic steel. The alloys were prepared from raw materials of 99.9% purity melted in a high frequency induction furnace under high vacuum. The samples were heat-treated in vacuum at various temperatures (800 to 1200ºC) for 1 hour followed by slow cooling (120ºC/h). The inverted torsional pendulum method was used to evaluate the vibration damping capacity. The results indicated that the vibration damping capacity of the alloys is influenced by annealing and there exists a critical annealing temperature after 1000ºC. The damping capacity increases quickly below the critical temperature since the magnetic domains move more easily.
Abstract: This paper presents an intrusion detection system of hybrid neural network model based on RBF and Elman. It is used for anomaly detection and misuse detection. This model has the memory function .It can detect discrete and related aggressive behavior effectively. RBF network is a real-time pattern classifier, and Elman network achieves the memory ability for former event. Based on the hybrid model intrusion detection system uses DARPA data set to do test evaluation. It uses ROC curve to display the test result intuitively. After the experiment it proves this hybrid model intrusion detection system can effectively improve the detection rate, and reduce the rate of false alarm and fail.