Abstract: Functional imaging procedures for the non-invasive assessment of tissue microcirculation are highly requested, but require a mathematical approach describing the trans- and intercapillary passage of tracer particles. Up to now, two theoretical, for the moment different concepts have been established for tracer kinetic modeling of contrast agent transport in tissues: pharmacokinetic compartment models, which are usually written as coupled differential equations, and the indicator dilution theory, which can be generalized in accordance with the theory of lineartime- invariant (LTI) systems by using a convolution approach. Based on mathematical considerations, it can be shown that also in the case of an open two-compartment model well-known from functional imaging, the concentration-time course in tissue is given by a convolution, which allows a separation of the arterial input function from a system function being the impulse response function, summarizing the available information on tissue microcirculation. Due to this reason, it is possible to integrate the open two-compartment model into the system-theoretic concept of indicator dilution theory (IDT) and thus results known from IDT remain valid for the compartment approach. According to the long number of applications of compartmental analysis, even for a more general context similar solutions of the so-called forward problem can already be found in the extensively available appropriate literature of the seventies and early eighties. Nevertheless, to this day, within the field of biomedical imaging – not from the mathematical point of view – there seems to be a trench between both approaches, which the author would like to get over by exemplary analysis of the well-known model.
Abstract: A new analytical method to predict the torsional
capacity and behavior of R.C multi-cell box girders strengthened with
carbon fiber reinforced polymer (CFRP) sheets is presented.
Modification was done on the Softened Truss Model (STM) in the
proposed method; the concrete torsional problem is solved by
combining the equilibrium conditions, compatibility conditions and
constitutive laws of materials by taking into account the confinement
of concrete with CFRP sheets. A specific algorithm is developed to
predict the torsional behavior of reinforced concrete multi-cell box
girders with or without strengthening by CFRP sheets. Applications
of the developed method as an assessment tool to strengthened multicell
box girders with CFRP and first analytical example that
demonstrate the contribution of the CFRP materials on the torsional
response is also included.
Abstract: Despite various methods that exist in software risk management, software projects have a high rate of failure. When complexity and size of the projects are increased, managing software development becomes more difficult. In these projects the need for more analysis and risk assessment is vital. In this paper, a classification for software risks is specified. Then relations between these risks using risk tree structure are presented. Analysis and assessment of these risks are done using probabilistic calculations. This analysis helps qualitative and quantitative assessment of risk of failure. Moreover it can help software risk management process. This classification and risk tree structure can apply to some software tools.
Abstract: This paper aims to select the optimal location and
setting parameters of TCSC (Thyristor Controlled Series
Compensator) controller using Particle Swarm Optimization (PSO)
and Genetic Algorithm (GA) to mitigate small signal oscillations in a
multimachine power system. Though Power System Stabilizers
(PSSs) are prime choice in this issue, installation of FACTS device
has been suggested here in order to achieve appreciable damping of
system oscillations. However, performance of any FACTS devices
highly depends upon its parameters and suitable location in the
power network. In this paper PSO as well as GA based techniques are
used separately and compared their performances to investigate this
problem. The results of small signal stability analysis have been
represented employing eigenvalue as well as time domain response in
face of two common power system disturbances e.g., varying load
and transmission line outage. It has been revealed that the PSO based
TCSC controller is more effective than GA based controller even
during critical loading condition.
Abstract: This paper presents a model for the characterization
and selection of beeswaxes for use as base substitute tissue for the
manufacture of objects suitable for external radiotherapy using
megavoltage photon beams. The model of characterization was
divided into three distinct stages: 1) verification of aspects related to
the origin of the beeswax, the bee species, the flora in the vicinity of
the beehives and procedures to detect adulterations; 2) evaluation of
physical and chemical properties; and 3) evaluation of beam
attenuation capacity. The chemical composition of the beeswax
evaluated in this study was similar to other simulators commonly
used in radiotherapy. The behavior of the mass attenuation coefficient
in the radiotherapy energy range was comparable to other simulators.
The proposed model is efficient and enables convenient assessment
of the use of any particular beeswax as a base substitute tissue for
radiotherapy.
Abstract: The use of renewable energy sources incl. biogas has become topical in accordance with the increasing demand for energy, decrease of fossil energy resources and the efforts to reduce greenhouse gas emissions as well as to increase energy independence from the territories where fossil energy resources are available.
As the technologies of biogas production from agricultural biomass develop, risk assessment and risk management become necessary for farms producing such a renewable energy. The need for risk assessments has become particularly topical when discussions on changing the biogas policy in the EU take place, which may influence the development of the sector in the future, as well as the operation of existing biogas facilities and their income level.
The current article describes results of the risk assessment for farms producing biomass from agriculture biomass in Latvia, the risk assessment system included 24 risks, that affect the whole biogas production process and the obtained results showed the high significance of political and production risks.
Abstract: Peer review is an activity where students review their
classmates- writing and then evaluate the content, development, unity
and organization. Studies have shown that peer review activities
benefit both the reviewer and the writer in developing their reading
and writing skills. Furthermore, peer review activities may also
enhance students- soft skills. This study was conducted to find out the
benefits of peer review activity in a technical writing class based on
engineering students- perceptions. The study also highlights how
these benefits could improve the students- soft skills. A set of
questionnaire was given to 200 undergraduate students of a technical
writing course. The results of the study indicate that the activity could
help improve their critical thinking skills, written and oral
communication skills, as well as team work. This paper further
discusses how the implications of these benefits could help enhance
students- soft skills.
Abstract: Campus sustainability is the goal of a university striving for sustainable development. This study found that of 17 popular approaches, two comprehensive campus sustainability assessment frameworks were developed in the context of Sustainability in Higher Education (SHE), and used by many university campuses around the world. Sustainability Tracking Assessment and Rating Systems (STARS) and the Campus Sustainability Assessment Framework (CSAF) approaches are more comprehensive than others. Therefore, the researchers examined aspects and elements used by CSAF and STARS in the approach to develop a campus sustainability assessment framework for Universiti Kebangsaan Malaysia (UKM). Documents analysis found that CSAF and STARS do not focus on physical development, especially the construction industry, as key elements of campus sustainability assessment. This finding is in accordance with the Sustainable UKM Programme which consists of three main components of sustainable community, ecosystem and physical development.
Abstract: Considering complexity of products, new geometrical
design and investment tolerances that are necessary, measuring and
dimensional controlling involve modern and more precise methods.
Photo digitizing method using two cameras to record pictures and
utilization of conventional method named “cloud points" and data
analysis by the use of ATOUS software, is known as modern and
efficient in mentioned context. In this paper, benefits of photo
digitizing method in evaluating sampling of machining processes
have been put forward. For example, assessment of geometrical
integrity surface in 5-axis milling process and measurement of
carbide tool wear in turning process, can be can be brought forward.
Advantages of this method comparing to conventional methods have
been expressed.
Abstract: Ground-level tropospheric ozone is one of the air
pollutants of most concern. It is mainly produced by photochemical
processes involving nitrogen oxides and volatile organic compounds
in the lower parts of the atmosphere. Ozone levels become
particularly high in regions close to high ozone precursor emissions
and during summer, when stagnant meteorological conditions with
high insolation and high temperatures are common.
In this work, some results of a study about urban ozone
distribution patterns in the city of Badajoz, which is the largest and
most industrialized city in Extremadura region (southwest Spain) are
shown. Fourteen sampling campaigns, at least one per month, were
carried out to measure ambient air ozone concentrations, during
periods that were selected according to favourable conditions to
ozone production, using an automatic portable analyzer.
Later, to evaluate the ozone distribution at the city, the measured
ozone data were analyzed using geostatistical techniques. Thus, first,
during the exploratory analysis of data, it was revealed that they were
distributed normally, which is a desirable property for the subsequent
stages of the geostatistical study. Secondly, during the structural
analysis of data, theoretical spherical models provided the best fit for
all monthly experimental variograms. The parameters of these
variograms (sill, range and nugget) revealed that the maximum
distance of spatial dependence is between 302-790 m and the
variable, air ozone concentration, is not evenly distributed in reduced
distances. Finally, predictive ozone maps were derived for all points
of the experimental study area, by use of geostatistical algorithms
(kriging). High prediction accuracy was obtained in all cases as
cross-validation showed. Useful information for hazard assessment
was also provided when probability maps, based on kriging
interpolation and kriging standard deviation, were produced.
Abstract: In this paper we canvass three case studies of unique
research partnerships between universities and schools in the wider
community. In doing so, we consider those areas of indeterminate
zones of professional practice explored by academics in their
research activities within the wider community. We discuss three
cases: an artist-in-residence program designed to engage primary
school children with new understandings about local Indigenous
Australian issues in their pedagogical and physical landscapes; an
assessment of pedagogical concerns in relation to the use of physical
space in classrooms; and the pedagogical underpinnings of a
costumed museum school program. In doing so, we engage issues of
research as playing an integral part in the development,
implementation and maintenance of academic engagements with
wider community issues.
Abstract: The accuracy of estimated stability and control
derivatives of a light aircraft from flight test data were evaluated. The light aircraft, named ChangGong-91, is the first certified aircraft from
the Korean government. The output error method, which is a maximum likelihood estimation technique and considers measurement
noise only, was used to analyze the aircraft responses measures. The
multi-step control inputs were applied in order to excite the short period mode for the longitudinal and Dutch-roll mode for the lateral-directional motion. The estimated stability/control derivatives of Chan Gong-91 were analyzed for the assessment of handling
qualities comparing them with those of similar aircraft. The accuracy of the flight derivative estimates derived from flight test measurement
was examined in engineering judgment, scatter and Cramer-Rao bound, which turned out to be satisfactory with minor defects..
Abstract: This study examines the inelastic behavior of adjacent planar reinforced concrete (R.C.) frames subjected to strong ground motions. The investigation focuses on the effects of vertical ground motion on the seismic pounding. The examined structures are modeled and analyzed by RUAUMOKO dynamic nonlinear analysis program using reliable hysteretic models for both structural members and contact elements. It is found that the vertical ground motion mildly affects the seismic response of adjacent buildings subjected to structural pounding and, for this reason, it can be ignored from the displacement and interstorey drifts assessment. However, the structural damage is moderately affected by the vertical component of earthquakes.
Abstract: Eight heavy metals (Cu, Cr, Zn, Hg, Pb, Cd, Ni and As) were analyzed in sediment samples in the dry and wet seasons from November 2009 to October 2010 in West Port of Peninsular Malaysia. The heavy metal concentrations (mg/kg dry weight) were ranged from 23.4 to 98.3 for Zn, 22.3 to 80 for Pb, 7.4 to 27.6 Cu, 0.244 to 3.53 for Cd, 7.2 to 22.2 for Ni, 20.2 to 162 for As, 0.11 to 0.409 for Hg and 11.5 to 61.5 for Cr. Metals concentrations in dry season were higher than the rainy season except in cupper and chromium. Analysis of variance with Statistical Analysis System (SAS) shows that the mean concentration of metals in the two seasons (α level=0.05) are not significantly different which shows that the metals were held firmly in the matrix of sediment. Also there are significant differences between control point station with other stations. According to the Interim Sediment Quality guidelines (ISQG), the metal concentrations are moderately polluted, except in arsenic which shows the highest level of pollution.
Abstract: Measurements of capacitance C and dissipation
factor tand of the stator insulation system provide useful information
about internal defects within the insulation. The index k is defined as
the proportionality constant between the changes at high voltage of
capacitance DC and of the dissipation factor Dtand . DC and
Dtand values were highly correlated when small flat defects were
within the insulation and that correlation was lost in the presence of
large narrow defects like electrical treeing. The discrimination
between small and large defects is made resorting to partial discharge
PD phase angle analysis. For the validation of the results, C and tand
measurements were carried out in a 15MVA 4160V steam turbine
turbogenerator placed in a sugar mill. In addition, laboratory test
results obtained by other authors were analyzed jointly. In such
laboratory tests, model coil bars subjected to thermal cycling resulted
highly degraded and DC and Dtand values were not correlated. Thus,
the index k could not be calculated.
Abstract: The scattering effect of light in fog improves the
difficulty in visibility thus introducing disturbances in transport
facilities in urban or industrial areas causing fatal accidents or public
harassments, therefore, developing an enhanced fog vision system
with radio wave to improvise the way outs of these severe problems
is really a big challenge for researchers. Series of experimental
studies already been done and more are in progress to know the
weather effect on radio frequencies for different ranges. According to
Rayleigh scattering Law, the propagating wavelength should be
greater than the diameter of the particle present in the penetrating
medium. Direct wave RF signal thus have high chance of failure to
work in such weather for detection of any object. Therefore an
extensive study was required to find suitable region in the RF band
that can help us in detecting objects with proper shape. This paper
produces some results on object detection using 912 MHz band with
successful detection of the persistence of any object coming under the
trajectory of a vehicle navigating in indoor and outdoor environment.
The developed images are finally transformed to video signal to
enable continuous monitoring.
Abstract: In conventional seedling production, the seedlings are
being grown in the open field under natural conditions. Here they are
susceptible to sudden changes in climate were their quality and yield
is affected. Quality seedlings are essential for good growth and
performance of crops in main field; they serve as a foundation for the
economic returns to the farmer. Producing quality seedling demands
usage of hybrid seeds as they have the ability to result in better yield,
greater uniformity, improved color, disease resistance, and so forth.
Hybrid seed production poses major operational challenge and its
seed use efficiency plays an important role. Thus in order to
overcome the difficulties currently present in conventional seedling
production and to efficiently use hybrid seeds, ITC Limited Agri
Business Divisions - Sustainability Cell as conceptualized a novel
method of seedling production unit for farmers in West Godavari
District of Andhra Pradesh. The “Green House based Float Seedling"
methodology aims at a protected cultivation technique wherein the
micro climate surrounding the plant/seedling body is controlled
partially or fully as per the requirement of the species. This paper
reports on the techno economic evaluation of green house for
cultivation of float based seedling production with experimental
results that was attained from the pilot implementation in West
Godavari District, Rajahmundry region of India.
Abstract: Turbine blade cooling is considered as the most
effective way of maintaining high operating temperature making use
of the available materials, and turbine systems with wet compression
have a potential for future power generation because of high efficiency
and high specific power with a relatively low cost. In this paper
performance analysis of wet-compression gas turbine cycle with
turbine blade cooling is carried out. The wet compression process is
analytically modeled based on non-equilibrium droplet evaporation.
Special attention is paid for the effects of pressure ratio and water
injection ratio on the important system variables such as ratio of
coolant fluid flow, fuel consumption, thermal efficiency and specific
power. Parametric studies show that wet compression leads to
insignificant improvement in thermal efficiency but significant
enhancement of specific power in gas turbine systems with turbine
blade cooling.
Abstract: In this paper three different approaches for person
verification and identification, i.e. by means of fingerprints, face and
voice recognition, are studied. Face recognition uses parts-based
representation methods and a manifold learning approach. The
assessment criterion is recognition accuracy. The techniques under
investigation are: a) Local Non-negative Matrix Factorization
(LNMF); b) Independent Components Analysis (ICA); c) NMF with
sparse constraints (NMFsc); d) Locality Preserving Projections
(Laplacianfaces). Fingerprint detection was approached by classical
minutiae (small graphical patterns) matching through image
segmentation by using a structural approach and a neural network as
decision block. As to voice / speaker recognition, melodic cepstral
and delta delta mel cepstral analysis were used as main methods, in
order to construct a supervised speaker-dependent voice recognition
system. The final decision (e.g. “accept-reject" for a verification
task) is taken by using a majority voting technique applied to the
three biometrics. The preliminary results, obtained for medium
databases of fingerprints, faces and voice recordings, indicate the
feasibility of our study and an overall recognition precision (about
92%) permitting the utilization of our system for a future complex
biometric card.
Abstract: this article proposed a methodology for computer
numerical control (CNC) machine scoring. The case study company
is a manufacturer of hard disk drive parts in Thailand. In this
company, sample of parts manufactured from CNC machine are
usually taken randomly for quality inspection. These inspection data
were used to make a decision to shut down the machine if it has
tendency to produce parts that are out of specification. Large amount
of data are produced in this process and data mining could be very
useful technique in analyzing them. In this research, data mining
techniques were used to construct a machine scoring model called
'machine priority assessment model (MPAM)'. This model helps to
ensure that the machine with higher risk of producing defective parts
be inspected before those with lower risk. If the defective prone
machine is identified sooner, defective part and rework could be
reduced hence improving the overall productivity. The results
showed that the proposed method can be successfully implemented
and approximately 351,000 baht of opportunity cost could have
saved in the case study company.