Abstract: The class of geometric deformable models, so-called
level sets, has brought tremendous impact to medical imagery. In
this paper we present yet another application of level sets to medical
imaging. The method we give here will in a way modify the speed
term in the standard level sets equation of motion. To do so we
build a potential based on the distance and the gradient of the
image we study. In turn the potential gives rise to the force field:
F~F(x, y) = P
∀(p,q)∈I
((x, y) - (p, q)) |ÔêçI(p,q)|
|(x,y)-(p,q)|
2 . The direction
and intensity of the force field at each point will determine the
direction of the contour-s evolution. The images we used to test
our method were produced by the Univesit'e de Sherbrooke-s PET
scanners.
Abstract: The similarity comparison of RNA secondary
structures is important in studying the functions of RNAs. In recent
years, most existing tools represent the secondary structures by
tree-based presentation and calculate the similarity by tree alignment
distance. Different to previous approaches, we propose a new method
based on maximum clique detection algorithm to extract the maximum
common structural elements in compared RNA secondary structures.
A new graph-based similarity measurement and maximum common
subgraph detection procedures for comparing purely RNA secondary
structures is introduced. Given two RNA secondary structures, the
proposed algorithm consists of a process to determine the score of the
structural similarity, followed by comparing vertices labelling, the
labelled edges and the exact degree of each vertex. The proposed
algorithm also consists of a process to extract the common structural
elements between compared secondary structures based on a proposed
maximum clique detection of the problem. This graph-based model
also can work with NC-IUB code to perform the pattern-based
searching. Therefore, it can be used to identify functional RNA motifs
from database or to extract common substructures between complex
RNA secondary structures. We have proved the performance of this
proposed algorithm by experimental results. It provides a new idea of
comparing RNA secondary structures. This tool is helpful to those
who are interested in structural bioinformatics.
Abstract: The paper reports on the results of experimental and
numerical study of nonstationary swirling flow in an isothermal
model of vortex burner. It has been identified that main source of the
instability is related to a precessing vortex core (PVC) phenomenon.
The PVC induced flow pulsation characteristics such as precession
frequency and its variation as a function of flowrate and swirl number
have been explored making use of acoustic probes. Additionally
pressure transducers were used to measure the pressure drops on the
working chamber and across the vortex flow. The experiments have
been included also the mean velocity measurements making use of a
laser-Doppler anemometry. The features of instantaneous flowfield
generated by the PVC were analyzed employing a commercial CFD
code (Star-CCM+) based on Detached Eddy Simulation (DES)
approach. Validity of the numerical code has been checked by
comparison calculated flowfield data with the obtained experimental
results. It has been confirmed particularly that the CFD code applied
correctly reproduces the flow features.
Abstract: Travelling salesman problem (TSP) is a combinational
optimization problem and solution approaches have been applied
many real world problems. Pure TSP assumes the cities to visit are
fixed in time and thus solutions are created to find shortest path
according to these point. But some of the points are canceled to visit
in time. If the problem is not time crucial it is not important to
determine new routing plan but if the points are changing rapidly and
time is necessary do decide a new route plan a new approach should
be applied in such cases. We developed a route plan transfer method
based on transfer learning and we achieved high performance against
determining a new model from scratch in every change.
Abstract: Flat double-layer grid is from category of space structures that are formed from two flat layers connected together with diagonal members. Increased stiffness and better seismic resistance in relation to other space structures are advantages of flat double layer space structures. The objective of this study is assessment and calculation of Behavior factor of flat double layer space structures. With regarding that these structures are used widely but Behavior factor used to design these structures against seismic force is not determined and exact, the necessity of study is obvious. This study is theoretical. In this study we used structures with span length of 16m and 20 m. All connections are pivotal. ANSYS software is used to non-linear analysis of structures.
Abstract: We have solved the Burgers-Fisher (BF) type equations,
with time-dependent coefficients of convection and reaction terms,
by using the auxiliary equation method. A class of solitary wave
solutions are obtained, and some of which are derived for the first
time. We have studied the effect of variable coefficients on physical
parameters (amplitude and velocity) of solitary wave solutions. In
some cases, the BF equations could be solved for arbitrary timedependent
coefficient of convection term.
Abstract: Flood management is one of the important fields in
urban storm water management. Floods are influenced by the
increase of huge storm event, or improper planning of the area. This study mainly provides the flood protection in four stages; planning,
flood event, responses and evaluation. However it is most effective then flood protection is considered in planning/design and
evaluation stages since both stages represent the land development of the area. Structural adjustments are often more reliable than nonstructural
adjustments in providing flood protection, however
structural adjustments are constrained by numerous factors such as
political constraints and cost. Therefore it is important to balance
both adjustments with the situation. The technical decisions provided
will have to be approved by the higher-ups who have the power to
decide on the final solution. Costs however, are the biggest factor in
determining the final decision. Therefore this study recommends
flood protection system should have been integrated and enforces
more in the early stages (planning and design) as part of the storm
water management plan. Factors influencing the technical decisions
provided should be reduced as low as possible to avoid a reduction in
the expected performance of the proposed adjustments.
Abstract: S-boxes (Substitution boxes) are keystones of modern
symmetric cryptosystems (block ciphers, as well as stream ciphers).
S-boxes bring nonlinearity to cryptosystems and strengthen their
cryptographic security. They are used for confusion in data security
An S-box satisfies the strict avalanche criterion (SAC), if and only if
for any single input bit of the S-box, the inversion of it changes each
output bit with probability one half. If a function (cryptographic
transformation) is complete, then each output bit depends on all of
the input bits. Thus, if it were possible to find the simplest Boolean
expression for each output bit in terms of the input bits, each of these
expressions would have to contain all of the input bits if the function
is complete. From some important properties of S-box, the most
interesting property SAC (Strict Avalanche Criterion) is presented
and to analyze this property three analysis methods are proposed.
Abstract: Thirty six samples from each (aerobic and anoxic)
activated sludge were collected from two wastewater treatment plants
with MBRs in Berlin, Germany. The samples were prepared for count
and definition of fungal isolates; these isolates were purified by
conventional techniques and identified by microscopic examination.
Sixty tow species belonging to 28 genera were isolated from
activated sludge samples under aerobic conditions (28 genera and 58
species) and anoxic conditions (26 genera and 52 species). The
obtained data show that, Aspergillus was found at 94.4% followed by
Penicillium 61.1 %, Fusarium (61.1 %), Trichoderma (44.4 %) and
Geotrichum candidum (41.6 %) species were the most prevalent in all
activated sludge samples. The study confirmed that fungi can thrive
in activated sludge and sporulation, but isolated in different numbers
depending on the effect of aeration system. Some fungal species in
our study are saprophytic, and other a pathogenic to plants and
animals.
Abstract: This calculation focus on the effect of exchange
interaction J and Coulomb interaction U on spin magnetic moments
(ms) of MnO by using the local spin density approximation plus the
Coulomb interaction (LSDA+U) method within full potential linear
muffin-tin orbital (FP-LMTO). Our calculated results indicated that
the spin magnetic moments correlated to J and U. The relevant
results exhibited the increasing spin magnetic moments with
increasing exchange interaction and Coulomb interaction.
Furthermore, equations of spin magnetic moment, which h good
correspondence to the experimental data 4.58μB, are defined ms =
0.11J +4.52μB and ms = 0.03U+4.52μB. So, the relation of J and U
parameter is obtained, it is obviously, J = -0.249U+1.346 eV.
Abstract: Vehicular Ad-Hoc Networks (VANET) can provide
communications between vehicles or infrastructures. It provides the
convenience of driving and the secure driving to reduce accidents. In
VANET, the security is more important because it is closely related to
accidents. Additionally, VANET raises a privacy issue because it can
track the location of vehicles and users- identity when a security
mechanism is provided. In this paper, we analyze the problem of an
existing solution for security requirements required in VANET, and
resolve the problem of the existing method when a key management
mechanism is provided for the security operation in VANET.
Therefore, we show suitability of the Long Term Evolution (LTE) in
VANET for the solution of this problem.
Abstract: The vertex connectivity of a graph is the smallest number of vertices whose deletion separates the graph or makes it trivial. This work is devoted to the problem of vertex connectivity test of graphs in a distributed environment based on a general and a constructive approach. The contribution of this paper is threefold. First, using a preconstructed spanning tree of the considered graph, we present a protocol to test whether a given graph is 2-connected using only local knowledge. Second, we present an encoding of this protocol using graph relabeling systems. The last contribution is the implementation of this protocol in the message passing model. For a given graph G, where M is the number of its edges, N the number of its nodes and Δ is its degree, our algorithms need the following requirements: The first one uses O(Δ×N2) steps and O(Δ×logΔ) bits per node. The second one uses O(Δ×N2) messages, O(N2) time and O(Δ × logΔ) bits per node. Furthermore, the studied network is semi-anonymous: Only the root of the pre-constructed spanning tree needs to be identified.
Abstract: In this research, Response Surface Methodology (RSM) is used to investigate the effect of four controllable input variables namely: discharge current, pulse duration, pulse off time and applied voltage Surface Roughness (SR) of on Electrical Discharge Machined surface. To study the proposed second-order polynomial model for SR, a Central Composite Design (CCD) is used to estimation the model coefficients of the four input factors, which are alleged to influence the SR in Electrical Discharge Machining (EDM) process. Experiments were conducted on AISI D2 tool steel with copper electrode. The response is modeled using RSM on experimental data. The significant coefficients are obtained by performing Analysis of Variance (ANOVA) at 5% level of significance. It is found that discharge current, pulse duration, and pulse off time and few of their interactions have significant effect on the SR. The model sufficiency is very satisfactory as the Coefficient of Determination (R2) is found to be 91.7% and adjusted R2-statistic (R2 adj ) 89.6%.
Abstract: Prospective readers can quickly determine whether a document is relevant to their information need if the significant phrases (or keyphrases) in this document are provided. Although keyphrases are useful, not many documents have keyphrases assigned to them, and manually assigning keyphrases to existing documents is costly. Therefore, there is a need for automatic keyphrase extraction. This paper introduces a new domain independent keyphrase extraction algorithm. The algorithm approaches the problem of keyphrase extraction as a classification task, and uses a combination of statistical and computational linguistics techniques, a new set of attributes, and a new machine learning method to distinguish keyphrases from non-keyphrases. The experiments indicate that this algorithm performs better than other keyphrase extraction tools and that it significantly outperforms Microsoft Word 2000-s AutoSummarize feature. The domain independence of this algorithm has also been confirmed in our experiments.
Abstract: The objective of this project is to produce computer
assisted instruction(CAI) for welding and brazing in order to
determine the efficiency of the instruction package and the study
accomplishment of learner by studying through computer assisted
instruction for welding and brazing it was examined through the
target group surveyed from the 30 students studying in the two year
of 5-year-academic program, department of production technology
education, faculty of industrial education and technology, king
mongkut-s university of technology thonburi. The result of the
research indicated that the media evaluated by experts and subject
matter quality evaluation of computer assisted instruction for welding
and brazing was in line for the good criterion. The mean of score
evaluated before the study, during the study and after the study was
34.58, 83.33 and 83.43, respectively. The efficiency of the lesson was
83.33/83.43 which was higher than the expected value, 80/80. The
study accomplishment of the learner, who utilizes computer assisted
instruction for welding and brazing as a media, was higher and equal
to the significance statistical level of 95%. The value was 1.669
which was equal to 35.36>1.669. It could be summarized that
computer assisted instruction for welding and brazing was the
efficient media to use for studying and teaching.
Abstract: A direct search approach to determine optimal reservoir operating is proposed with ant colony optimization for continuous domains (ACOR). The model is applied to a system of single reservoir to determine the optimum releases during 42 years of monthly steps. A disadvantage of ant colony based methods and the ACOR in particular, refers to great amount of computer run time consumption. In this study a highly effective procedure for decreasing run time has been developed. The results are compared to those of a GA based model.
Abstract: Antiseismic property of telecommunication equipment
is very important for the grasp of the damage and the restoration after
earthquake. Telecommunication business operators are regulating
seismic standard for their equipments. These standards are organized
to simulate the real seismic situations and usually define the minimum
value of first natural frequency of the equipments or the allowable
maximum displacement of top of the equipments relative to bottom.
Using the finite element analysis, natural frequency can be obtained
with high accuracy but the relative displacement of top of the
equipments is difficult to predict accurately using the analysis.
Furthermore, in the case of simulating the equipments with access
floor, predicting the relative displacement of top of the equipments
become more difficult.
In this study, using enormous experimental datum, an empirical
formula is suggested to forecast the relative displacement of top of the
equipments. Also it can be known that which physical quantities are
related with the relative displacement.
Abstract: We have considered an unmagnetized dusty plasma system consisting of ions obeying superthermal distribution and strongly coupled negatively charged dust. We have used reductive perturbation method and derived the Kordeweg-de Vries-Burgers (KdV-Burgers) equation. The behavior of the shock waves in the plasma has been investigated.
Abstract: This evaluation of land supply system performance in
China shall examine the combination of government functions and
national goals in order to perform a cost-benefit analysis of system
results. From the author's point of view, it is most productive to
evaluate land supply system performance at moments of system
transformation for the following reasons. The behavior and
input-output change of beneficial results at different times can be
observed when the system or policy changes and system performance
can be evaluated through a cost-benefit analysis during the process of
system transformation. Moreover, this evaluation method can avoid
the influence of land resource endowment. Different land resource
endowment methods and different economy development periods
result in different systems. This essay studies the contents, principles
and methods of land supply system performance evaluation. Taking
Beijing as an example, this essay optimizes and classifies the land
supply index, makes a quantitative evaluation of land supply system
performance through principal component analysis (PCA), and finally
analyzes the factors that influence land supply system performance at
times of system transformation.
Abstract: When designing satellites, one of the major issues aside for designing its primary subsystems is to devise its thermal. The thermal management of satellites requires solving different sets of issues with regards to modelling. If the satellite is well conditioned all other parts of the satellite will have higher temperature no matter what. The main issue of thermal modelling for satellite design is really making sure that all the other points of the satellite will be within the temperature limits they are designed. The insertion of power electronics in aerospace technologies is becoming widespread and the modern electronic systems used in space must be reliable and efficient with thermal management unaffected by outer space constraints. Many advanced thermal management techniques have been developed in recent years that have application in high power electronic systems. This paper presents a Three-Dimensional Modal Transmission Line Matrix (3D-TLM) implementation of transient heat flow in space power electronics. In such kind of components heat dissipation and good thermal management are essential. Simulation provides the cheapest tool to investigate all aspects of power handling. The 3DTLM has been successful in modeling heat diffusion problems and has proven to be efficient in terms of stability and complex geometry. The results show a three-dimensional visualisation of self-heating phenomena in the device affected by outer space constraints, and will presents possible approaches for increasing the heat dissipation capability of the power modules.