Abstract: In this paper, we propose a high capacity image hiding
technology based on pixel prediction and the difference of modified histogram. This approach is used the pixel prediction and the
difference of modified histogram to calculate the best embedding point.
This approach can improve the predictive accuracy and increase the pixel difference to advance the hiding capacity. We also use the
histogram modification to prevent the overflow and underflow. Experimental results demonstrate that our proposed method within the
same average hiding capacity can still keep high quality of image and low distortion
Abstract: In this paper, numerical simulation is used to
investigate the thermal performance of liquid cooling heatsink with
microchannels due to geometric arrangement. Commercial software
ICEPAK is utilized for the analysis. The considered parameters
include aspect ratio, porosity and the length and height of
microchannel. The aspect ratio varies from 3 to 16 and the length of
microchannel is 10mm, 14mm, and 18mm. The height of
microchannel is 2mm, 3mm and 4mm. It is found short channel have
better thermal efficiency than long channel at 490Pa. No matter the
length of channel the best aspect ratio is 4. It is also noted that pressure
difference at 2940Pa the best aspect ratio from 4 to 8, it means pressure
difference affect aspect ratio, effective thermal resistance at low
pressure difference but lower effective thermal resistance at high
pressure difference.
Abstract: This study experimentally and numerically investigates
motor cooling performance. The motor consists of a centrifugal fan,
two axial fans, a shaft, a stator, a rotor and a heat exchanger with 637
cooling tubes. The pressure rise-flow rate (P-Q) performance curves of
the cooling fans at 1800 rpm are tested using a test apparatus
complying with the Chinese National Standard (CNS) 2726.
Compared with the experimental measurements, the numerical
analysis results show that the P-Q performance curves of the axial fan
and centrifugal fan can be estimated within about 2% and 6%,
respectively. By using the simplified model, setting up the heat
exchanger and stator as porous media, the flow field in the motor is
calculated. By using the results of the flow field near the rotor and
stator, and subjecting the heat generation rate as a boundary condition,
the temperature distributions of the stator and rotor are also calculated.
The simulation results show that the calculated temperature of the
stator winding near the axial fans is lower by about 5% than the
measured value, and the calculated temperature of the stator core
located at the center of the stator is about 1% higher than the measured
value. Besides, discussion is made to improve the motor cooling
performance.
Abstract: Data Envelopment Analysis (DEA) is a methodology
that computes efficiency values for decision making units (DMU) in a
given period by comparing the outputs with the inputs. In many cases,
there are some time lag between the consumption of inputs and the
production of outputs. For a long-term research project, it is hard to
avoid the production lead time phenomenon. This time lag effect
should be considered in evaluating the performance of organizations.
This paper suggests a model to calculate efficiency values for the
performance evaluation problem with time lag. In the experimental
part, the proposed methods are compared with the CCR and an
existing time lag model using the data set of the 21st century frontier
R&D program which is a long-term national R&D program of Korea.
Abstract: Shear-layer instabilities of a pulsed stack-issued
transverse jet were studied experimentally in a wind tunnel. Jet
pulsations were induced by means of acoustic excitation. Streak
pictures of the smoke-flow patterns illuminated by the laser-light sheet
in the median plane were recorded with a high-speed digital camera.
Instantaneous velocities of the shear-layer instabilities in the flow were
digitized by a hot-wire anemometer. By analyzing the streak pictures
of the smoke-flow visualization, three characteristic flow modes,
synchronized flapping jet, transition, and synchronized shear-layer
vortices, are identified in the shear layer of the pulsed stack-issued
transverse jet at various excitation Strouhal numbers. The shear-layer
instabilities of the pulsed stack-issued transverse jet are synchronized
by acoustic excitation except for transition mode. In transition flow
mode, the shear-layer vortices would exhibit a frequency that would be
twice as great as the acoustic excitation frequency.
Abstract: In research on natural ventilation, and passive cooling
with forced convection, is essential to know how heat flows in a solid
object and the pattern of temperature distribution on their surfaces,
and eventually how air flows through and convects heat from the
surfaces of steel under roof. This paper presents some results from
running the computational fluid dynamic program (CFD) by
comparison between natural ventilation and forced convection within
roof attic that is received directly from solar radiation. The CFD
program for modeling air flow inside roof attic has been modified to
allow as two cases. First case, the analysis under natural ventilation,
is closed area in roof attic and second case, the analysis under forced
convection, is opened area in roof attic. These extend of all cases to
available predictions of variations such as temperature, pressure, and
mass flow rate distributions in each case within roof attic. The
comparison shows that this CFD program is an effective model for
predicting air flow of temperature and heat transfer coefficient
distribution within roof attic. The result shows that forced convection
can help to reduce heat transfer through roof attic and an around area
of steel core has temperature inner zone lower than natural
ventilation type. The different temperature on the steel core of roof
attic of two cases was 10-15 oK.
Abstract: With the proliferation of mobile computing technology, mobile learning (m-learning) will play a vital role in the rapidly growing electronic learning market. However, the acceptance of m-learning by individuals is critical to the successful implementation of m-learning systems. Thus, there is a need to research the factors that affect users- intention to use m-learning. Based on an updated information system (IS) success model, data collected from 350 respondents in Taiwan were tested against the research model using the structural equation modeling approach. The data collected by questionnaire were analyzed to check the validity of constructs. Then hypotheses describing the relationships between the identified constructs and users- satisfaction were formulated and tested.
Abstract: This paper develops the fiscal health index of 21 local
governments in Taiwan over the 1984 to 2010 period. A quantile
regression analysis was used to explore the extent that economic
variables, political budget cycles, and legislative checks and balances,
impact different quantiles of fiscal health index for a country over a
sample period of time. Our findings suggest that local governments at
the lower quantile are significantly benefited from political budget
cycles and the increase in central government revenues, while
legislative effective checks and balances and the increase in central
government expenditures have a significantly negative effect on local
fiscal health. When local governments are in the upper tail of the
distribution, legislative checks and balances and growth in
macroeconomics have significant and adverse effects on the fiscal
health of local governments. However, increases in central
government revenues have significant and positive effects on the
health status of local government in Taiwan.
Abstract: As part of national epidemiological survey on bovine
viral diarrhea virus (BVDV), a total of 274 dejecta samples were
collected from 14 cattle farms in 8 areas of Xinjiang Uygur
Autonomous Region in northwestern China. Total RNA was extracted
from each sample, and 5--untranslated region (UTR) of BVDV
genome was amplified by using two-step reverse
transcriptase-polymerase chain reaction (RT-PCR). The PCR products
were subsequently sequenced to study the genetic variations of BVDV
in these areas. Among the 274 samples, 33 samples were found
virus-positive. According to sequence analysis of the PCR products,
the 33 samples could be arranged into 16 groups. All the sequences,
however, were highly conserved with BVDV Osloss strains. The virus
possessed theses sequences belonged to BVDV-1b subtype by
phylogenetic analysis. Based on these data, we established a typing
tree for BVDV in these areas. Our results suggested that BVDV-1b
was a predominant subgenotype in northwestern China and no
correlation between the genetic and geographical distances could be
observed above the farm level.
Abstract: Non-viral gene carriers composed of biodegradable
polymers or lipids have been considered as a safer alternative for gene
carriers over viral vectors. We have developed multi-functional
nano-micelles for both drug and gene delivery application.
Polyethyleneimine (PEI) was modified by grafting stearic acid (SA)
and formulated to polymeric micelles (PEI-SA) with positive surface
charge for gene and drug delivery. Our results showed that PEI-SA
micelles provided high siRNA binding efficiency. In addition, siRNA
delivered by PEI-SA carriers also demonstrated significantly high
cellular uptake even in the presence of serum proteins. The
post-transcriptional gene silencing efficiency was greatly improved by
the polyplex formulated by 10k PEI-SA/siRNA. The amphiphilic
structure of PEI-SA micelles provided advantages for multifunctional
tasks; where the hydrophilic shell modified with cationic charges can
electrostatically interact with DNA or siRNA, and the hydrophobic
core can serve as payloads for hydrophobic drugs, making it a
promising multifunctional vehicle for both genetic and chemotherapy
application.
Abstract: In this paper, a delayed physiological control system is investigated. The sufficient conditions for stability of positive equilibrium and existence of local Hopf bifurcation are derived. Furthermore, global existence of periodic solutions is established by using the global Hopf bifurcation theory. Finally, numerical examples are given to support the theoretical analysis.
Abstract: The electromagnetic imaging of inhomogeneous
dielectric cylinders buried in a slab medium by transverse electric
(TE) wave illumination is investigated. Dielectric cylinders of
unknown permittivities are buried in second space and scattered a
group of unrelated waves incident from first space where the scattered
field is recorded. By proper arrangement of the various unrelated
incident fields, the difficulties of ill-posedness and nonlinearity are
circumvented, and the permittivity distribution can be reconstructed
through simple matrix operations. The algorithm is based on the
moment method and the unrelated illumination method. Numerical
results are given to demonstrate the capability of the inverse
algorithm. Good reconstruction is obtained even in the presence of
additive Gaussian random noise in measured data. In addition, the
effect of noise on the reconstruction result is also investigated.
Abstract: The dynamics of a delayed mathematical model for
Hes1 oscillatory expression are investigated. The linear stability of
positive equilibrium and existence of local Hopf bifurcation are
studied. Moreover, the global existence of large periodic solutions
has been established due to the global bifurcation theorem.
Abstract: The culture of riding heavy motorcycles originates
from advanced countries and mainly comes from Europe, North
America, and Japan. Heavy duty motorcycle riders are different from
people who view motorcycles as a convenient mean of transportation.
They regard riding them as a kind of enjoyment and high-level taste.
The activities of riding heavy duty motorcycles have formes a
distinctive landscape in domestic land in Taiwan. Previous studies
which explored motorcycle culture in Taiwan still focused on the
objects of motorcycle engine displacement under 50 cc.. The study
aims to study the heavy duty motorcycles of engine displacement over
550 cc. and explores where their attractiveness is. For finding the
attractiveness of heavy duty motorcycle, the study chooses Miryoku
Engineering (Preference-Based Design) approach. Two steps are
adopted to proceed the research. First, through arranging the letters
obtained from interviewing experts, EGM (The Evaluation Grid
Method) was applied to find out the structure of attractiveness. The
attractive styles are eye-dazzling, leisure, classic, and racing
competitive styles. Secondarily, Quantification Theory Type I analysis
was adopted as a tool for analyzing the importance of attractiveness.
The relationship between style and attractive parts was also discussed.
The results could contribute to the design and research development of
heavy duty motorcycle industry in Taiwan.
Abstract: For stricter drinking water regulations in the future, reducing the humic acid and disinfection byproducts in raw water, namely, trihalomethanes (THMs) and haloacetic acids (HAAs) is worthy for research. To investigate the removal of waterborne organic material using a lab-scale of bio-activated carbon filter under different EBCT, the concentrations of humic acid prepared were 0.01, 0.03, 0.06, 0.12, 0.17, 0.23, and 0.29 mg/L. Then we conducted experiments using a pilot plant with in-field of the serially connected bio-activated carbon filters and hollow fiber membrane processes employed in traditional water purification plants. Results showed under low TOC conditions of humic acid in influent (0.69 to 1.03 mg TOC/L) with an EBCT of 30 min, 40 min, and 50 min, TOC removal rates increases with greater EBCT, attaining about 39 % removal rate. The removal rate of THMs and HAAs by BACF was 54.8 % and 89.0 %, respectively.
Abstract: This paper presents a text clustering system developed based on a k-means type subspace clustering algorithm to cluster large, high dimensional and sparse text data. In this algorithm, a new step is added in the k-means clustering process to automatically calculate the weights of keywords in each cluster so that the important words of a cluster can be identified by the weight values. For understanding and interpretation of clustering results, a few keywords that can best represent the semantic topic are extracted from each cluster. Two methods are used to extract the representative words. The candidate words are first selected according to their weights calculated by our new algorithm. Then, the candidates are fed to the WordNet to identify the set of noun words and consolidate the synonymy and hyponymy words. Experimental results have shown that the clustering algorithm is superior to the other subspace clustering algorithms, such as PROCLUS and HARP and kmeans type algorithm, e.g., Bisecting-KMeans. Furthermore, the word extraction method is effective in selection of the words to represent the topics of the clusters.
Abstract: The main goal in this paper is to quantify the quality of
different techniques for radiation treatment plans, a back-propagation
artificial neural network (ANN) combined with biomedicine theory
was used to model thirteen dosimetric parameters and to calculate
two dosimetric indices. The correlations between dosimetric indices
and quality of life were extracted as the features and used in the ANN
model to make decisions in the clinic. The simulation results show
that a trained multilayer back-propagation neural network model can
help a doctor accept or reject a plan efficiently. In addition, the
models are flexible and whenever a new treatment technique enters
the market, the feature variables simply need to be imported and the
model re-trained for it to be ready for use.
Abstract: With the help of coincidence degree theory, sufficient
conditions for existence of periodic solutions for a food chain model
with functional responses on time scales are established.
Abstract: Search for a tertiary substructure that geometrically
matches the 3D pattern of the binding site of a well-studied protein provides a solution to predict protein functions. In our previous work,
a web server has been built to predict protein-ligand binding sites
based on automatically extracted templates. However, a drawback of such templates is that the web server was prone to resulting in many
false positive matches. In this study, we present a sequence-order constraint to reduce the false positive matches of using automatically
extracted templates to predict protein-ligand binding sites. The binding site predictor comprises i) an automatically constructed template library and ii) a local structure alignment algorithm for
querying the library. The sequence-order constraint is employed to
identify the inconsistency between the local regions of the query protein and the templates. Experimental results reveal that the sequence-order constraint can largely reduce the false positive matches and is effective for template-based binding site prediction.
Abstract: In a previously developed fast vortex method, the
diffusion of the vortex sheet induced at the solid wall by the no-slip
boundary conditions was modeled according to the approximation
solution of Koumoutsakos and converted into discrete blobs in the
vicinity of the wall. This scheme had been successfully applied to a
simulation of the flow induced with an impulsively initiated circular
cylinder. In this work, further modifications on this vortex method are
attempted, including replacing the approximation solution by the
boundary-element-method solution, incorporating a new algorithm for
handling the over-weak vortex blobs, and diffusing the vortex sheet
circulation in a new way suitable for high-curvature solid bodies. The
accuracy is thus largely improved. The predictions of lift and drag
coefficients for a uniform flow past a NASA airfoil agree well with the
existing literature.