Abstract: Selecting the routes and the assignment of link flow in a computer communication networks are extremely complex combinatorial optimization problems. Metaheuristics, such as genetic or simulated annealing algorithms, are widely applicable heuristic optimization strategies that have shown encouraging results for a large number of difficult combinatorial optimization problems. This paper considers the route selection and hence the flow assignment problem. A genetic algorithm and simulated annealing algorithm are used to solve this problem. A new hybrid algorithm combining the genetic with the simulated annealing algorithm is introduced. A modification of the genetic algorithm is also introduced. Computational experiments with sample networks are reported. The results show that the proposed modified genetic algorithm is efficient in finding good solutions of the flow assignment problem compared with other techniques.
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: Mutations of the telomeric copy of the survival motor neuron 1 (SMN1) gene cause spinal muscular atrophy. A deletion of the Eef1a2 gene leads to lower motor neuron degeneration in wasted mice. Indirect evidences have been shown that the eEF1A protein family may interact with SMN, and our previous study showed that abnormalities of neuromuscular junctions in wasted mice were similar to those of Smn mutant mice. To determine potential colocalization between SMN and tissue-specific translation elongation factor 1A2 (eEF1A2), an immunochemical analysis of HeLa cells transfected with the plasmid pcDNA3.1(+)C-hEEF1A2- myc and a new quantitative test of colocalization by intensity correlation analysis (ICA) was used to explore the association of SMN and eEF1A2. Here the results showed that eEF1A2 redistributed from the cytoplasm to the nucleus in response to serum and epidermal growth factor. In the cytoplasm, compelling evidence showed that staining for myc-tagged eEF1A2 varied in synchrony with that for SMN, consistent with the formation of a SMN-eEF1A2 complex in the cytoplasm of HeLa cells. These findings suggest that eEF1A2 may colocalize with SMN in the cytoplasm and may be a component of the SMN complex. However, the limitation of the ICA method is an inability to resolve colocalization in components of small organelles such as the nucleus.
Abstract: This paper presents a new and efficient approach for capacitor placement in radial distribution systems that determine the optimal locations and size of capacitor with an objective of improving the voltage profile and reduction of power loss. The solution methodology has two parts: in part one the loss sensitivity factors are used to select the candidate locations for the capacitor placement and in part two a new algorithm that employs Plant growth Simulation Algorithm (PGSA) is used to estimate the optimal size of capacitors at the optimal buses determined in part one. The main advantage of the proposed method is that it does not require any external control parameters. The other advantage is that it handles the objective function and the constraints separately, avoiding the trouble to determine the barrier factors. The proposed method is applied to 9, 34, and 85-bus radial distribution systems. The solutions obtained by the proposed method are compared with other methods. The proposed method has outperformed the other methods in terms of the quality of solution.
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: In this paper, the energy performance of a selected
UHDE Ammonia plant is optimized by conducting heat integration through waste heat recovery and the synthesis of a heat exchange
network (HEN). Minimum hot and cold utility requirements were estimated through IChemE spreadsheet. Supporting simulation was
carried out using HYSYS software. The results showed that there is
no need for heating utility while the required cold utility was found to
be around 268,714 kW. Hence a threshold pinch case was faced. Then, the hot and cold streams were matched appropriately. Also,
waste heat recovered resulted with savings in HP and LP steams of
approximately 51.0% and 99.6%, respectively. An economic analysis
on proposed HEN showed very attractive overall payback period not
exceeding 3 years. In general, a net saving approaching 35% was
achieved in implementing heat optimization of current studied UHDE Ammonia process.
Abstract: This study was carried out to develop a flotation
procedure for an oxide copper ore from a Region in Central Africa
for producing an 18% copper concentrate for downstream processing
at maximum recovery from a 4% copper feed grade. The copper
recoveries achieved from the test work were less than 50% despite
changes in reagent conditions (multistage sulphidisation, use of RCA
emulsion and mixture, use of AM 2, etc). The poor recoveries were
attributed to the mineralogy of the ore from which copper silicates
accounted for approximately 70% (mass) of the copper minerals in
the ore. These can be complex and difficult to float using
conventional flotation methods. Best results were obtained using
basic sulphidisation procedures, a high flotation temperature and
extended flotation residence time.
Abstract: Group key management is an important functional
building block for any secure multicast architecture.
Thereby, it has been extensively studied in the literature.
In this paper we present relevant group key management
protocols. Then, we compare them against some pertinent
performance criteria.
Abstract: Pyrolysis of waste tire is one of alternative technique
to produce petrochemicals, such as light olefins, mixed C4, and monoaromatics.
Noble metals supported on acid zeolite catalysts were
reported as potential catalysts to produce the high valuable products
from waste tire pyrolysis. Especially, Pd supported on HBeta gave a
high yield of olefins, mixed C4, and mono-aromatics. Due to the high
prices of noble metals, the objective of this work was to investigate
whether or not a non-noble Ni metal can be used as a substitute of a
noble metal, Pd, supported on HBeta as a catalyst for waste tire pyrolysis.
Ni metal was selected in this work because Ni has high activity
in cracking, isomerization, hydrogenation and the ring opening of
hydrocarbons Moreover, Ni is an element in the same group as Pd
noble metal, which is VIIIB group, aiming to produce high valuable
products similarly obtained from Pd. The amount of Ni was varied as
5, 10, and 20% by weight, for comparison with a fixed 1 wt% Pd,
using incipient wetness impregnation. The results showed that as a
petrochemical-producing catalyst, 10%Ni/HBeta performed better
than 1%Pd/HBeta because it did not only produce the highest yield of
olefins and cooking gases, but the yields were also higher than
1%Pd/HBeta. 5%Ni/HBeta can be used as a substitute of
1%Pd/HBeta for similar crude production because its crude contains
the similar amounts of naphtha and saturated HCs, although it gave
no concentration of light mono-aromatics (C6-C11) in the oil. Additionally,
10%Ni/HBeta that gave high olefins and cooking gases was
found to give a fairly high concentration of the light mono-aromatics
in the oil.
Abstract: In this paper, the techniques for estimating the
residual stress in high velocity oxy fuel thermal spray coatings have
been discussed and compared. The development trend and the last
investigation have been studied. It is seemed that the there is not
effective study on the effect of the peening action in HVOF
analytically and numerically.
Abstract: As the fossil fuels kept on depleting, intense research in developing hydrogen (H2) as the alternative fuel has been done to cater our tremendous demand for fuel. The potential of H2 as the ultimate clean fuel differs with the fossil fuel that releases significant amounts of carbon dioxide (CO2) into the surrounding and leads to the global warming. The experimental work was carried out to study the production of H2 from palm kernel shell steam gasification at different variables such as heating rate, steam to biomass ratio and adsorbent to biomass ratio. Maximum H2 composition which is 61% (volume basis) was obtained at heating rate of 100oCmin-1, steam/biomass of 2:1 ratio, and adsorbent/biomass of 1:1 ratio. The commercial adsorbent had been modified by utilizing the alcoholwater mixture. Characteristics of both adsorbents were investigated and it is concluded that flowability and floodability of modified CaO is significantly improved.
Abstract: The compressive strength development through
polymerization process of alkaline solution and fly ash blended with Microwave Incinerated Rice Husk Ash (MIRHA) is described in this
paper. Three curing conditions, which are hot gunny curing, ambient
curing, and external humidity curing are investigated to obtain the suitable curing condition for cast in situ provision. Fly ash was
blended with MIRHA at 3%, 5%, and 7% to identify the effect of blended mixes to the compressive strength and microstructure
properties of geopolymer concrete. Compressive strength results
indicated an improvement in the strength development with external humidity curing concrete samples compared to hot gunny curing and
ambient curing. Blended mixes also presented better performance
than control mixes. Improvement of interfacial transition zone (ITZ)
and micro structure in external humidity concrete samples were also
identified compared to hot gunny and ambient curing.
Abstract: The seismic response of steel shear wall system considering nonlinearity effects using finite element method is investigated in this paper. The non-linear finite element analysis has potential as usable and reliable means for analyzing of civil structures with the availability of computer technology. In this research the large displacements and materially nonlinear behavior of shear wall is presented with developing of finite element code. A numerical model based on the finite element method for the seismic analysis of shear wall is presented with developing of finite element code in this research. To develop the finite element code, the standard Galerkin weighted residual formulation is used. Two-dimensional plane stress model and total Lagrangian formulation was carried out to present the shear wall response and the Newton-Raphson method is applied for the solution of nonlinear transient equations. The presented model in this paper can be developed for analysis of civil engineering structures with different material behavior and complicated geometry.
Abstract: Mixed-traffic (e.g., pedestrians, bicycles, and vehicles)
data at an intersection is one of the essential factors for intersection
design and traffic control. However, some data such as pedestrian
volume cannot be directly collected by common detectors (e.g.
inductive loop, sonar and microwave sensors). In this paper, a video
based detection algorithm is proposed for mixed-traffic data collection
at intersections using surveillance cameras. The algorithm is derived
from Gaussian Mixture Model (GMM), and uses a mergence time
adjustment scheme to improve the traditional algorithm. Real-world
video data were selected to test the algorithm. The results show that
the proposed algorithm has the faster processing speed and more
accuracy than the traditional algorithm. This indicates that the
improved algorithm can be applied to detect mixed-traffic at
signalized intersection, even when conflicts occur.
Abstract: Binder drainage test is widely used to set an upper
limit to the design binder content of porous asphalt. However, the
presence of high amount of fine particles in the drained binder may
affect the accuracy of the test result. This paper presents a study to
characterize the composition and particle size distribution of fine
particles accumulated in the drained binder. Fine aggregates and filler
in the drained binder were extracted using a suitable solvent. Then,
wet and dry sieve analysis was carried out to identify the actual
composition of the extracted fine aggregates and filler. From the
results, almost half of the drained binder consisted of fine aggregates
and this significantly affects the accuracy of the design binder content
of porous asphalt mix. This simple finding highlights the importance
of taking into account the presence of fine aggregates in the
calculation of drained binder.
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: A study was carried out to determine the effect of water quality on flotation performance. The experimental test work comprised of batch flotation tests using Denver lab cell for a period of 10 minutes. Nine different test runs were carried out in triplicates to ensure reproducibility using different water types from different thickener overflows, return and sewage effluent water (process water) and portable water. The water sources differed in pH, total dissolved solids, total suspended solids and conductivity. Process water was found to reduce the concentrate recovery and mass pull, while portable water increased the concentrate recovery and mass pull. Portable water reduced the concentrate grade while process water increased the concentrate grade. It is proposed that a combination of process water and portable water supply be used in flotation circuits to balance the different effects that the different water types have on the flotation efficiency.
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: This study has been prepared with the purpose to get the views of senior class Elementary Education Mathematics preservice teachers on proving. Data have been obtained via surveys and interviews carried out with 104 preservice teachers. According to the findings, although preservice teachers have positive views about using proving in mathematics teaching, it is seen that their experiences related to proving is limited to courses and they think proving is a work done only for the exams. Furthermore, they have expressed in the interviews that proving is difficult for them, and because of this reason they prefer memorizing instead of learning.
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.