Abstract: Scaffolds play a key role in tissue engineering and can be produced in many different ways depending on the applications and the materials used. Most researchers used an experimental trialand- error approach into new biomaterials but computer simulation applied to tissue engineering can offer a more exhaustive approach to test and screen out biomaterials. This paper develops the model of scaffolds and Computational Fluid Dynamics that show the value of computer simulations in determining the influence of the geometrical scaffold parameter porosity, pore size and shape on the permeability of scaffolds, magnitude of velocity, drop pressure, shear stress distribution and level and the proper design of the geometry of the scaffold. This creates a need for more advanced studies that include aspects of dynamic conditions of a micro fluid passing through the scaffold were characterized for tissue engineering applications and differentiation of tissues within scaffolds.
Abstract: In this paper, a simple heuristic genetic algorithm is
used for Multistage Multiuser detection in fast fading environments.
Multipath channels, multiple access interference (MAI) and near far
effect cause the performance of the conventional detector to degrade.
Heuristic Genetic algorithms, a rapidly growing area of artificial
intelligence, uses evolutionary programming for initial search, which
not only helps to converge the solution towards near optimal
performance efficiently but also at a very low complexity as
compared with optimal detector. This holds true for Additive White
Gaussian Noise (AWGN) and multipath fading channels.
Experimental results are presented to show the superior performance
of the proposed techque over the existing methods.
Abstract: Gliding during night without electric power is an efficient method to enhance endurance performance of solar aircrafts. The properties of maximum gliding endurance path are studied in this paper. The problem is formulated as an optimization problem about maximum endurance can be sustained by certain potential energy storage with dynamic equations and aerodynamic parameter constrains. The optimal gliding path is generated based on gauss pseudo-spectral method. In order to analyse relationship between altitude, velocity of solar UAVs and its endurance performance, the lift coefficient in interval of [0.4, 1.2] and flight envelopes between 0~30km are investigated. Results show that broad range of lift coefficient can improve solar aircrafts- long endurance performance, and it is possible for a solar aircraft to achieve the aim of long endurance during whole night just by potential energy storage.
Abstract: In this paper we propose a method which improves the efficiency of video coding. Our method combines an adaptive GOP (group of pictures) structure and the shot cut detection. We have analyzed different approaches for shot cut detection with aim to choose the most appropriate one. The next step is to situate N frames to the positions of detected cuts during the process of video encoding. Finally the efficiency of the proposed method is confirmed by simulations and the obtained results are compared with fixed GOP structures of sizes 4, 8, 12, 16, 32, 64, 128 and GOP structure with length of entire video. Proposed method achieved the gain in bit rate from 0.37% to 50.59%, while providing PSNR (Peak Signal-to-Noise Ratio) gain from 1.33% to 0.26% in comparison to simulated fixed GOP structures.
Abstract: Real world Speaker Identification (SI) application
differs from ideal or laboratory conditions causing perturbations that
leads to a mismatch between the training and testing environment
and degrade the performance drastically. Many strategies have been
adopted to cope with acoustical degradation; wavelet based Bayesian
marginal model is one of them. But Bayesian marginal models
cannot model the inter-scale statistical dependencies of different
wavelet scales. Simple nonlinear estimators for wavelet based
denoising assume that the wavelet coefficients in different scales are
independent in nature. However wavelet coefficients have significant
inter-scale dependency. This paper enhances this inter-scale
dependency property by a Circularly Symmetric Probability Density
Function (CS-PDF) related to the family of Spherically Invariant
Random Processes (SIRPs) in Log Gabor Wavelet (LGW) domain
and corresponding joint shrinkage estimator is derived by Maximum
a Posteriori (MAP) estimator. A framework is proposed based on
these to denoise speech signal for automatic speaker identification
problems. The robustness of the proposed framework is tested for
Text Independent Speaker Identification application on 100 speakers
of POLYCOST and 100 speakers of YOHO speech database in three
different noise environments. Experimental results show that the
proposed estimator yields a higher improvement in identification
accuracy compared to other estimators on popular Gaussian Mixture
Model (GMM) based speaker model and Mel-Frequency Cepstral
Coefficient (MFCC) features.
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: 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: The effects of commercial or bovine yeasts on the
performance and blood variables of broiler chickens intoxicated with
aflatoxin were investigated in broilers. Four hundred eighty broilers
(Arbor Acres; 3-wk-old) were randomly assigned to 4 groups. Each
group (120 broiler chickens) was further randomly divided into 6
replicates of 20 chickens. The treatments were control diet without
additives (treatment 1), 250 ppb AFB1 (treatment 2), commercial
yeast, Saccharomyces cerevisiae, (CY 2.5 x 107 CFU/g) + 250 ppb
AFB1 (treatment 3) and bovine yeast, Saccharomyces cerevisiae,
(BY 2.5 x 107 CFU/g + 250 ppb AFB1 (treatment 4). Complete
randomized design (CRD) was used in the experiment. Feed
consumption and body weight were recorded at every five-day
period. On day 42, carcass compositions were determined from 30
birds per treatment. While chicks were sacrificed, 3-4 ml blood
sample was taken and stored frozen at (-20°C) for serum chemical
analysis to determine effects of consumption of diets on blood
chemistry (total protein, albumin, glucose, urea, cholesterol and
triglycerides). There were no significant differences in ADFI among
the treatments(P>0.05). However, BWG, FCR and mortality were
highly significantly different (P
Abstract: The experiment was performed to study the
relationship between excreta viscosity and Nitrogen-corrected true
metabolisable energy quantities of soybean meals using conventional
addition method (CAM) in adult cockerels for 7 d: a 3-d preexperiment
and a 4-d experiment period. Results indicated that
differences between the excreta viscosity values were (P
Abstract: Studies have shown that the SnAgCu solder family has been widely used as a replacement for conventional Sn-Pb solders. An attractive approach is by introducing alloying additives (rare earth elements (RE), Zn, Co, Fe, Ni, Sb) into the SnAgCu solder, which helps in refining the microstructure also improving the mechanical and wetting properties of the solder. The present work focuses on the effect of additions of 0.5% Ce and Fe into Sn-3.0Ag-0.5Cu solder, in attempt to reduce the intermetallic compound (IMC) growth and reflow properties of the solder on Cu and Ni (P) surface finish, as well as effects thermal aging on the formation of intermetallic compound (IMC) on different surface finish. Excessive intermetallic compound growth may effect the interface and solder joint due to the brittle nature of the intermetallic compounds. Thus, by introducing alloying elements, IMC layer thickness can be decrease, resulting in better joint and solder reliability.
Abstract: The objective of this research was to study the factors
related to the satisfaction of consumers who purchased a Toyota
SUV Fortuner. This paper was a survey data which collected 400
samples from 65 car dealerships. The survey was conducted mainly
in Bangkok, Thailand. The statistics utilized in this paper included
percentage, mean, standard deviation and Pearson Product-Moment.
The findings revealed that the majority of respondent were male with
an undergraduate degree, married and live together. The average
income of the respondents was between 20,001 - 30,000 baht. Most
of them worked for private companies. Most of them had a family
with the average of 4 members. The hypotheses testing revealed that
the factors of marketing mix in terms of product (ability, gas
mileage, and safety) were related to overall satisfaction at the
medium level. However, the findings also revealed that the factors of
marketing mix in terms of product (image), price, and promotion, and
service center were related to the overall satisfaction at the low level.
Abstract: The recognition of human faces, especially those with
different orientations is a challenging and important problem in image
analysis and classification. This paper proposes an effective scheme
for rotation invariant face recognition using Log-Polar Transform and
Discrete Cosine Transform combined features. The rotation invariant
feature extraction for a given face image involves applying the logpolar
transform to eliminate the rotation effect and to produce a row
shifted log-polar image. The discrete cosine transform is then applied
to eliminate the row shift effect and to generate the low-dimensional
feature vector. A PSO-based feature selection algorithm is utilized to
search the feature vector space for the optimal feature subset.
Evolution is driven by a fitness function defined in terms of
maximizing the between-class separation (scatter index).
Experimental results, based on the ORL face database using testing
data sets for images with different orientations; show that the
proposed system outperforms other face recognition methods. The
overall recognition rate for the rotated test images being 97%,
demonstrating that the extracted feature vector is an effective rotation
invariant feature set with minimal set of selected features.
Abstract: Digital watermarking is one of the techniques for
copyright protection. In this paper, a normalization-based robust
image watermarking scheme which encompasses singular value
decomposition (SVD) and discrete cosine transform (DCT)
techniques is proposed. For the proposed scheme, the host image is
first normalized to a standard form and divided into non-overlapping
image blocks. SVD is applied to each block. By concatenating the
first singular values (SV) of adjacent blocks of the normalized image,
a SV block is obtained. DCT is then carried out on the SV blocks to
produce SVD-DCT blocks. A watermark bit is embedded in the highfrequency
band of a SVD-DCT block by imposing a particular
relationship between two pseudo-randomly selected DCT
coefficients. An adaptive frequency mask is used to adjust local
watermark embedding strength. Watermark extraction involves
mainly the inverse process. The watermark extracting method is blind
and efficient. Experimental results show that the quality degradation
of watermarked image caused by the embedded watermark is visually
transparent. Results also show that the proposed scheme is robust
against various image processing operations and geometric attacks.
Abstract: Document image processing has become an
increasingly important technology in the automation of office
documentation tasks. During document scanning, skew is inevitably
introduced into the incoming document image. Since the algorithm
for layout analysis and character recognition are generally very
sensitive to the page skew. Hence, skew detection and correction in
document images are the critical steps before layout analysis. In this
paper, a novel skew detection method is presented for binary
document images. The method considered the some selected
characters of the text which may be subjected to thinning and Hough
transform to estimate skew angle accurately. Several experiments
have been conducted on various types of documents such as
documents containing English Documents, Journals, Text-Book,
Different Languages and Document with different fonts, Documents
with different resolutions, to reveal the robustness of the proposed
method. The experimental results revealed that the proposed method
is accurate compared to the results of well-known existing methods.
Abstract: The effect of moisture content and loading rate on
mechanical strength of 12 brown rice grain varieties was determined.
The results showed that the rupture force of brown rice grain
decreased by increasing the moisture content and loading rate. The
highest rupture force values was obtained at the moisture content of
8% (w.b.) and loading rate of 10 mm/min; while the lowest rupture
force corresponded to the moisture content of 14% (w.b.) and loading
rate of 15 mm/min. The 12 varieties were divided into three groups,
namely local short grain varieties, local long grain varieties and
improved long grain varieties. It was observed that the rupture
strength of the three groups were statistically different from each
other (P
Abstract: Phylogenies ; The evolutionary histories of groups of
species are one of the most widely used tools throughout the life
sciences, as well as objects of research with in systematic,
evolutionary biology. In every phylogenetic analysis reconstruction
produces trees. These trees represent the evolutionary histories of
many groups of organisms, bacteria due to horizontal gene transfer
and plants due to process of hybridization. The process of gene
transfer in bacteria and hybridization in plants lead to reticulate
networks, therefore, the methods of constructing trees fail in
constructing reticulate networks. In this paper a model has been
employed to reconstruct phylogenetic network in honey bee. This
network represents reticulate evolution in honey bee. The maximum
parsimony approach has been used to obtain this reticulate network.
Abstract: Ozone (O3) is considered as one of the most
phytotoxic pollutants with deleterious effects on living and non living
components of Ecosystems. It reduces growth and yield of many
crops as well as alters the physiology and crop quality. The present
study described series of experiments to investigate the effects of
ambient O3 at different locations with different ambient levels of O3
depending on proximity to pollutant source and ranged between 17
ppb/h in control experiment to 112 ppb/h in industrial area
respectively. The ambient levels in other three locations (King Saud
University botanical garden, King Fahd Rd, and Almanakh Garden)
were 61,61,77 ppb/h respectively. Tow legume crops species (vicia
vaba L ; and Pisum sativum) differ in their phenology and sensitivity
were used. The results showed a significant negative effect to ozone
on morphology, number of injured leaves, growth and productivity
with a difference in the degree of response depending on the plant
type. Visia Faba showed sensitivity to ozone to number and leaf area
and the degree of injury leaves 3, pisum sativum show higher
sensitivity for the gas for degree of injury 1,The relative growth rate
and seed weight, it turns out there is no significant difference
between the two plants in plant height and number of seeds.
Abstract: Ten simply supported grossly underreinforced
tapered concrete beams of full size were tested upto complete
collapse under flexural effect .Out of 10 beams, 5 beams were
nonfibrous and the remaining beams contained fibres. The beams
had a variation in the tapered angle as 2°, 4°, 6°, 8° and 10°. The
concrete mix, conventional steel and the type of fibre used were
held constant. Flat corrugated steel fibres were utilized as
secondary reinforcement. The strength and stability parameters
were measured. It is established that the fibrous tapered beams can
be used economically in earthquake prone areas.
Abstract: This paper presents a solution for the behavioural animation of autonomous virtual agent navigation in virtual environments. We focus on using Dempster-Shafer-s Theory of Evidence in developing visual sensor for virtual agent. The role of the visual sensor is to capture the information about the virtual environment or identifie which part of an obstacle can be seen from the position of the virtual agent. This information is require for vitual agent to coordinate navigation in virtual environment. The virual agent uses fuzzy controller as a navigation system and Fuzzy α - level for the action selection method. The result clearly demonstrates the path produced is reasonably smooth even though there is some sharp turn and also still not diverted too far from the potential shortest path. This had indicated the benefit of our method, where more reliable and accurate paths produced during navigation task.
Abstract: Transpedicular screw fixation in spinal fractures,
degenerative changes, or deformities is a well-established procedure.
However, important rate of fixation failure due to screw bending,
loosening, or pullout are still reported particularly in weak bone stock
in osteoporosis. To overcome the problem, mechanism of failure has
to be fully investigated in vitro. Post-mortem human subjects are less
accessible and animal cadavers comprise limitations due to different
geometry and mechanical properties. Therefore, the development of a
synthetic model mimicking the realistic human vertebra is highly
demanded. A bone surrogate, composed of Polyurethane (PU) foam
analogous to cancellous bone porous structure, was tested for 3
different densities in this study. The mechanical properties were
investigated under uniaxial compression test by minimizing the end
artifacts on specimens. The results indicated that PU foam of 0.32
g.cm-3 density has comparable mechanical properties to human
cancellous bone in terms of young-s modulus and yield strength.
Therefore, the obtained information can be considered as primary
step for developing a realistic cancellous bone of human vertebral
body. Further evaluations are also recommended for other density
groups.