Abstract: An induced acyclic graphoidal cover of a graph G is a
collection ψ of open paths in G such that every path in ψ has atleast
two vertices, every vertex of G is an internal vertex of at most one
path in ψ, every edge of G is in exactly one path in ψ and every
member of ψ is an induced path. The minimum cardinality of an
induced acyclic graphoidal cover of G is called the induced acyclic
graphoidal covering number of G and is denoted by ηia(G) or ηia.
Here we find induced acyclic graphoidal cover for some classes of
graphs.
Abstract: The predictability of masonry arch bridges and their
behaviour is widely considered doubtful due to the lack of knowledge
about the conditions of a given masonry arch bridge. The assessment
methods for masonry arch bridges are MEXE, ARCHIE, RING and
Frame Analysis Method. The material properties of the masonry and
fill material are extremely difficult to determine accurately.
Consequently, it is necessary to examine the effect of load dispersal
angle through the fill material, the effect of variations in the stiffness
of the masonry, the tensile strength of the masonry mortar continuum
and the compressive strength of the masonry mortar continuum. It is
also important to understand the effect of fill material on load
dispersal angle to determine their influence on ratings. In this paper a
series of parametric studies, to examine the sensitivity of assessment
ratings to the various sets of input data required by the frame analysis
method, are carried out.
Abstract: Among many different methods that are used for
optimizing different engineering problems mathematical (numerical)
optimization techniques are very important because they can easily
be used and are consistent with most of engineering problems. Many
studies and researches are done on stability analysis of three
dimensional (3D) slopes and the relating probable slip surfaces and
determination of factors of safety, but in most of them force
equilibrium equations, as in simplified 2D methods, are considered
only in two directions. In other words for decreasing mathematical
calculations and also for simplifying purposes the force equilibrium
equation in 3rd direction is omitted. This point is considered in just a
few numbers of previous studies and most of them have only given a
factor of safety and they haven-t made enough effort to find the most
probable slip surface. In this study shapes of the slip surfaces are
modeled, and safety factors are calculated considering the force
equilibrium equations in all three directions, and also the moment
equilibrium equation is satisfied in the slip direction, and using
nonlinear programming techniques the shape of the most probable
slip surface is determined. The model which is used in this study is a
3D model that is composed of three upper surfaces which can cover
all defined and probable slip surfaces. In this research the meshing
process is done in a way that all elements are prismatic with
quadrilateral cross sections, and the safety factor is defined on this
quadrilateral surface in the base of the element which is a part of the
whole slip surface. The method that is used in this study to find the
most probable slip surface is the non-linear programming method in
which the objective function that must get optimized is the factor of
safety that is a function of the soil properties and the coordinates of
the nodes on the probable slip surface. The main reason for using
non-linear programming method in this research is its quick
convergence to the desired responses. The final results show a good
compatibility with the previously used classical and 2D methods and
also show a reasonable convergence speed.
Abstract: This paper studied the synthesis of monoacylglycerol (monolaurin) by glycerolysis of coconut oil and crude glycerol, catalyzed by Carica papaya lipase. Coconut oil obtained from cold pressed extraction method and crude glycerol obtained from the biodiesel plant in Department of Chemistry, Uttaradit Rajabhat University, Thailand which used oils were used as raw materials for biodiesel production through transesterification process catalyzed by sodium hydroxide. The influences of the following variables were studied: (i) type of organic solvent, (ii) molar ratio of substrate, (iii) reaction temperature, (iv) reaction time, (v) lipase dosage, and (vi) initial water activity of enzyme. High yields in monoacylglycerol (58.35%) were obtained with molar ratio of glycerol to oil at 8:1 in ethanol, temperature was controlled at 45oC for 36 hours, the amount of enzyme used was 20 wt% of oil and initial water activity of enzyme at 0.53.
Abstract: Numerical design optimization is a powerful tool that
can be used by engineers during any stage of the design process.
There are many different applications for structural optimization. A
specific application that will be discussed in the following paper is
experimental data matching. Data obtained through tests on a physical
structure will be matched with data from a numerical model of that
same structure. The data of interest will be the dynamic characteristics
of an antenna structure focusing on the mode shapes and modal
frequencies. The structure used was a scaled and simplified model of
the Karoo Array Telescope-7 (KAT-7) antenna structure.
This kind of data matching is a complex and difficult task. This
paper discusses how optimization can assist an engineer during the
process of correlating a finite element model with vibration test data.
Abstract: In this paper, algorithms for the automatic localisation
of two anatomical soft tissue landmarks of the head the medial
canthus (inner corner of the eye) and the tragus (a small, pointed,
cartilaginous flap of the ear), in CT images are describet. These
landmarks are to be used as a basis for an automated image-to-patient
registration system we are developing. The landmarks are localised
on a surface model extracted from CT images, based on surface
curvature and a rule based system that incorporates prior knowledge
of the landmark characteristics. The approach was tested on a dataset
of near isotropic CT images of 95 patients. The position of the
automatically localised landmarks was compared to the position of
the manually localised landmarks. The average difference was 1.5
mm and 0.8 mm for the medial canthus and tragus, with a maximum
difference of 4.5 mm and 2.6 mm respectively.The medial canthus
and tragus can be automatically localised in CT images, with
performance comparable to manual localisation
Abstract: Ontologies and tagging systems are two different ways to organize the knowledge present in the current Web. In this paper we propose a simple method to model folksonomies, as tagging systems, with ontologies. We show the scalability of the method using real data sets. The modeling method is composed of a generic ontology that represents any folksonomy and an algorithm to transform the information contained in folksonomies to the generic ontology. The method allows representing folksonomies at any instant of time.
Abstract: Ultrasonic machining (USM) is a non-traditional
machining process being widely used for commercial machining of
brittle and fragile materials such as glass, ceramics and
semiconductor materials. However, USM could be a viable
alternative for machining a tough material such as titanium; and this
aspect needs to be explored through experimental research. This
investigation is focused on exploring the use of ultrasonic machining
for commercial machining of pure titanium (ASTM Grade-I) and
evaluation of tool wear rate (TWR) under controlled experimental
conditions. The optimal settings of parameters are determined
through experiments planned, conducted and analyzed using Taguchi
method. In all, the paper focuses on parametric optimization of
ultrasonic machining of pure titanium metal with TWR as response,
and validation of the optimized value of TWR by conducting
confirmatory experiments.
Abstract: Coal fly ash (CFA) generated by coal-based thermal
power plants is mainly composed of some oxides having high
crystallinity, like quartz and mullite. In this study, the effect of CFA
crystallinity toward lead adsorption capacity was investigated. To get
solid with various crystallinity, the solution of sodium hydroxide
(NaOH) of 1-7 M was used to treat CFA at various temperature and
reflux time. Furthermore, to evaluate the effect of NaOH-treated CFA
with respect to adsorption capacity, the treated CFA were examine as
adsorbent for removing lead in the solution. The result shows that
using NaOH to treat CFA causes crystallinity of quartz and mullite
decrease. At higher NaOH concentration (>3M), in addition the
damage of quartz and mullite crystallinity is followed by crystal
formation called hydroxysodalite. The lower crystalllinity, the higher
adsorption capacity.
Abstract: This paper proposes a direct power control for
doubly-fed induction machine for variable speed wind power
generation. It provides decoupled regulation of the primary side
active and reactive power and it is suitable for both electric energy
generation and drive applications. In order to control the power
flowing between the stator of the DFIG and the network, a decoupled
control of active and reactive power is synthesized using PI
controllers.The obtained simulation results show the feasibility
and the effectiveness of the suggested method
Abstract: This paper describes analysis of low velocity transverse impact on fully backed sandwich beams with composite faces from Eglass/epoxy and cores from Polyurethane or PVC. Indentation on sandwich beams has been analyzed with the existing theories and modeled with the FE code ABAQUS, also loadings have been done experimentally to verify theoretical results. Impact on fully backed has been modeled in two cases of impactor energy with SDOF model (single-degree-of-freedom) and indentation stiffness: lower energy for elastic indentation of sandwich beams and higher energy for plastic area in indentation. Impacts have been modeled by ABAQUS. Impact results can describe response of beam in terms of core and faces thicknesses, core material, indentor energy and energy absorbed. The foam core is modeled using the crushable foam material model and response of the foam core is experimentally characterized in uniaxial compression with higher velocity loading to define quasi impact behaviour.
Abstract: At a time of growing market turbulence and a strong
shifts towards increasingly complex risk models and more stringent audit requirements, it is more critical than ever to maintain the highest quality of financial and credit information. IFC implemented
an approach that helps increase data integrity and quality significantly. This approach is called “Screening". Screening is based on linking information from different sources to identify potential
inconsistencies in key financial and credit data. That, in turn, can help
to ease the trials of portfolio supervision, and improve overall company global reporting and assessment systems. IFC experience
showed that when used regularly, Screening led to improved information.
Abstract: In order to develop any strategy, it is essential to first
identify opportunities, threats, weak and strong points. Assessment of
technology level provides the possibility of concentrating on weak
and strong points. The results of technology assessment have a direct
effect on decision making process in the field of technology transfer
or expansion of internal research capabilities so it has a critical role
in technology management. This paper presents a conceptual model
to analyze the technology capability of a company as a whole and in
four main aspects of technology. This model was tested on 10
automotive parts manufacturers in IRAN. Using this model,
capability level of manufacturers was investigated in four fields of
managing aspects, hard aspects, human aspects, and information and
knowledge aspects. Results show that these firms concentrate on hard
aspect of technology while others aspects are poor and need to be
supported more. So this industry should develop other aspects of
technology as well as hard aspect to have effective and efficient use
of its technology. These paper findings are useful for the technology
planning and management in automotive part manufactures in IRAN
and other Industries which are technology followers and transport
their needed technologies.
Abstract: This paper describes WiPoD (Wireless Position
Detector) which is a pure software based location determination and
tracking (positioning) system. It uses empirical signal strength measurements from different wireless access points for mobile user
positioning. It is designed to determine the location of users having
802.11 enabled mobile devices in an 802.11 WLAN infrastructure
and track them in real time. WiPoD is the first main module in our
LBS (Location Based Services) framework. We tested K-Nearest
Neighbor and Triangulation algorithms to estimate the position of a
mobile user. We also give the analysis results of these algorithms for
real time operations. In this paper, we propose a supportable, i.e.
understandable, maintainable, scalable and portable wireless
positioning system architecture for an LBS framework. The WiPoD
software has a multithreaded structure and was designed and implemented with paying attention to supportability features and real-time constraints and using object oriented design principles. We also describe the real-time software design issues of a wireless positioning system which will be part of an LBS framework.
Abstract: Complex assemblies of interacting proteins carry out
most of the interesting jobs in a cell, such as metabolism, DNA
synthesis, mitosis and cell division. These physiological properties
play out as a subtle molecular dance, choreographed by underlying
regulatory networks that control the activities of cyclin-dependent
kinases (CDK). The network can be modeled by a set of nonlinear
differential equations and its behavior predicted by numerical
simulation. In this paper, an innovative approach has been proposed
that uses genetic algorithms to mine a set of behavior data output by
a biological system in order to determine the kinetic parameters of
the system. In our approach, the machine learning method is
integrated with the framework of existent biological information in a
wiring diagram so that its findings are expressed in a form of system
dynamic behavior. By numerical simulations it has been illustrated
that the model is consistent with experiments and successfully shown
that such application of genetic algorithms will highly improve the
performance of mathematical model of the cell division cycle to
simulate such a complicated bio-system.
Abstract: The purpose of this research was to study five vital
factors related to employees’ job performance. A total of 250
respondents were sampled from employees who worked at a public
warehouse organization, Bangkok, Thailand. Samples were divided
into two groups according to their work experience. The average
working experience was about 9 years for group one and 28 years for
group two. A questionnaire was utilized as a tool to collect data.
Statistics utilized in this research included frequency, percentage,
mean, standard deviation, t-test analysis, one way ANOVA, and
Pearson Product-moment correlation coefficient. Data were analyzed
by using Statistical Package for the Social Sciences. The findings
disclosed that the majority of respondents were female between 23-
31 years old, single, and hold an undergraduate degree. The average
income of respondents was less than 30,900 baht. The findings also
revealed that the factors of organization chart awareness, job process
and technology, internal environment, employee loyalty, and policy
and management were ranked as medium level. The hypotheses
testing revealed that difference in gender, age, and position had
differences in terms of the awareness of organization chart, job
process and technology, internal environment, employee loyalty, and
policy and management in the same direction with low level.
Abstract: When an assignable cause(s) manifests itself to a multivariate process and the process shifts to an out-of-control condition, a root-cause analysis should be initiated by quality engineers to identify and eliminate the assignable cause(s) affected the process. A root-cause analysis in a multivariate process is more complex compared to a univariate process. In the case of a process involved several correlated variables an effective root-cause analysis can be only experienced when it is possible to identify the required knowledge including the out-of-control condition, the change point, and the variable(s) responsible to the out-of-control condition, all simultaneously. Although literature addresses different schemes to monitor multivariate processes, one can find few scientific reports focused on all the required knowledge. To the best of the author’s knowledge this is the first time that a multi task model based on artificial neural network (ANN) is reported to monitor all the required knowledge at the same time for a multivariate process with more than two correlated quality characteristics. The performance of the proposed scheme is evaluated numerically when different step shifts affect the mean vector. Average run length is used to investigate the performance of the proposed multi task model. The simulated results indicate the multi task scheme performs all the required knowledge effectively.
Abstract: The main emphasis of metallurgists has been to process the materials to obtain the balanced mechanical properties for the given application. One of the processing routes to alter the properties is heat treatment. Nearly 90% of the structural applications are related to the medium carbon an alloyed steels and hence are regarded as structural steels. The major requirement in the conventional steel is to improve workability, toughness, hardness and grain refinement. In this view, it is proposed to study the mechanical and tribological properties of unalloyed structural (AISI 1140) steel with different thermal (heat) treatments like annealing, normalizing, tempering and hardening and compared with as brought (cold worked) specimen. All heat treatments are carried out in atmospheric condition. Hardening treatment improves hardness of the material, a marginal decrease in hardness value with improved ductility is observed in tempering. Annealing and normalizing improve ductility of the specimen. Normalized specimen shows ultimate ductility. Hardened specimen shows highest wear resistance in the initial period of slide wear where as above 25KM of sliding distance, as brought steel dominates the hardened specimen. Both mild and severe wear regions are observed. Microstructural analysis shows the existence of pearlitic structure in normalized specimen, lath martensitic structure in hardened, pearlitic, ferritic structure in annealed specimen.
Abstract: Promoting critical thinking (CT) in an educational
setting has been appraised in order to enhance learning and
intellectual skills. In this study, a pedagogical course in a vocational
teacher education program in Turkey was designed by integrating CT
skill-based strategies/activities into the course content and CT skills
were means leading to intended course objectives. The purpose of the
study was to evaluate the importance of the course objectives, the
attainment of the objectives, and the effectiveness of teachinglearning
strategies/activities from prospective teachers- points of
view. The results revealed that although the students mostly
considered the course objectives important, they did not feel
competent in the attainment of all objectives especially in those
related to the main topic of Learning and those requiring higher order
thinking skills. On the other hand, the students considered the course
activities effective for learning and for the development of thinking
skills, especially, in interpreting, comparing, questioning,
contrasting, and forming relationships.
Abstract: Relevant agricultural information disseminator
(extension agent) ratio of 1:3500 farm families which become a
menace to agricultural production capacity in developing countries
necessitate this study. Out of 4 zones in the state, 24 extension agents
in each zone, 4 extension agents using cell phones and 120 farmers
using cell phone and 120 other farmers not using cell phone were
purposively selected to give 240 farmers that participated in the
research. Data were collected using interview guide and analysized
using frequency, percentage and t-test.. Frequency of contact with
agricultural information centers revealed that cell phone user farmers
had greater means score of X 41.43 contact as against the low mean
X19.32 contact recorded by farmers receiving agricultural
information from extension agents not using cell phone and their
production was statistically significant at P < 0.05. Usage of cell
phone increase extension agent contact and increase farmers-
production capacity.