Abstract: Bode stability analysis based on transmission line
modeling (TLM) for single wall carbon nanotube (SWCNT)
interconnects used in 3D-VLSI circuits is investigated for the first
time. In this analysis, the dependence of the degree of relative
stability for SWCNT interconnects on the geometry of each tube has
been acquired. It is shown that, increasing the length and diameter of
each tube, SWCNT interconnects become more stable.
Abstract: A sequential decision problem, based on the task ofidentifying the species of trees given acoustic echo data collectedfrom them, is considered with well-known stochastic classifiers,including single and mixture Gaussian models. Echoes are processedwith a preprocessing stage based on a model of mammalian cochlearfiltering, using a new discrete low-pass filter characteristic. Stoppingtime performance of the sequential decision process is evaluated andcompared. It is observed that the new low pass filter processingresults in faster sequential decisions.
Abstract: Arenga pinnata is an abundantly natural fiber that can be used for sound proof material. However, the scientific data of acoustics properties of Arenga pinnata was not available yet. In this study the sound absorption of pure arenga pinnata was measured. The thickness of Arenga pinnata was varied in 10 mm, 20 mm, 30mm, and 40mm. This work was carried out to investigate the potential of using Arenga pinnata fiber as raw material for sound absorbing material. Impedance Tube Method was used to measure sound absorption coefficient (α). The Measurements was done in accordance with ASTM E1050-98, that is the standard test method for impedance and absorption of acoustical materials using a tube, two microphones and a digital frequency analysis system . The results showed that sound absorption coefficients of Arenga pinnata were good from 2000 Hz to 5000 Hz within the range of 0.75 – 0.90. The optimum sound absorption coefficient was obtained from the thickness of 40 mm. These results indicated that Arenga pinnata fiber is promising to be used as raw material of sound absorbing material with low cost, light, and biodegradable.
Abstract: Few studies have been conducted on polymeric strip
and the behavior of soil retaining walls. This paper will present the
effect of frequency on the dynamic behavior of reinforced soil
retaining walls with polymeric strips. The frequency content
describes how the amplitude of a ground motion is distributed among
different frequencies. Since the frequency content of an earthquake
motion will strongly influence the effects of that motion, the
characterization of the motion cannot be completed without the
consideration of its frequency content. The maximum axial force of
reinforcements and horizontal displacement of the reinforced walls
are focused in this research. To clarify the dynamic behavior of
reinforced soil retaining walls with polymeric strips, a numerical
modeling using Finite Difference Method is benefited. As the results
indicate, the frequency of input base acceleration has an important
effect on the behavior of these structures. Because of resonant in the
system, where the frequency of the input dynamic load is equal to the
natural frequency of the system, the maximum horizontal
displacement and the maximum axial forces in polymeric strips is
occurred. Moreover, they were to increase the structure flexibility
because of the main advantages of polymeric strips; i.e. being simple
method of construction, having a homogeneous behavior with soils,
and possessing long durability, which are of great importance in
dynamic analysis.
Abstract: The cost of developing the software from scratch can
be saved by identifying and extracting the reusable components from
already developed and existing software systems or legacy systems
[6]. But the issue of how to identify reusable components from
existing systems has remained relatively unexplored. We have used
metric based approach for characterizing a software module. In this
present work, the metrics McCabe-s Cyclometric Complexity
Measure for Complexity measurement, Regularity Metric, Halstead
Software Science Indicator for Volume indication, Reuse Frequency
metric and Coupling Metric values of the software component are
used as input attributes to the different types of Neural Network
system and reusability of the software component is calculated. The
results are recorded in terms of Accuracy, Mean Absolute Error
(MAE) and Root Mean Squared Error (RMSE).
Abstract: Due to the fact that in the new century customers tend
to express globally increasing demands, networks of interconnected
businesses have been established in societies and the management of
such networks seems to be a major key through gaining competitive
advantages. Supply chain management encompasses such managerial
activities. Within a supply chain, a critical role is played by quality.
QFD is a widely-utilized tool which serves the purpose of not only
bringing quality to the ultimate provision of products or service
packages required by the end customer or the retailer, but it can also
initiate us into a satisfactory relationship with our initial customer;
that is the wholesaler. However, the wholesalers- cooperation is
considerably based on the capabilities that are heavily dependent on
their locations and existing circumstances. Therefore, it is undeniable
that for all companies each wholesaler possesses a specific
importance ratio which can heavily influence the figures calculated in
the House of Quality in QFD. Moreover, due to the competitiveness
of the marketplace today, it-s been widely recognized that
consumers- expression of demands has been highly volatile in
periods of production. Apparently, such instability and proneness to
change has been very tangibly noticed and taking it into account
during the analysis of HOQ is widely influential and doubtlessly
required. For a more reliable outcome in such matters, this article
demonstrates the application viability of Analytic Network Process
for considering the wholesalers- reputation and simultaneously
introduces a mortality coefficient for the reliability and stability of
the consumers- expressed demands in course of time. Following to
this, the paper provides further elaboration on the relevant
contributory factors and approaches through the calculation of such
coefficients. In the end, the article concludes that an empirical
application is needed to achieve broader validity.
Abstract: The focal spot of a high intensity focused ultrasound
transducer is small. To heat a large target volume, multiple treatment spots are required. If the power of each treatment spot is fixed, it could
results in insufficient heating of initial spots and over-heating of later ones, which is caused by the thermal diffusion. Hence, to produce a
uniform heated volume, the delivered energy of each treatment spot
should be properly adjusted. In this study, we proposed an iterative, extrapolation technique to adjust the required ultrasound energy of
each treatment spot. Three different scanning pathways were used to evaluate the performance of this technique. Results indicate that by using the proposed technique, uniform heating volume could be obtained.
Abstract: Rice husk is a lignocellulosic source that can be
converted to ethanol. Three hundreds grams of rice husk was mixed
with 1 L of 0.18 N sulfuric acid solutions then was heated in an
autoclave. The reaction was expected to be at constant temperature
(isothermal), but before that temperature was achieved, reaction has
occurred. The first liquid sample was taken at temperature of 140 0C
and repeated every 5 minute interval. So the data obtained are in the
regions of non-isothermal and isothermal. It was observed that the
degradation has significant effects on the ethanol production. The
kinetic constants can be expressed by Arrhenius equation with the
frequency factors for hydrolysis and sugar degradation of 1.58 x 105
min-1 and 2.29 x 108 L/mole-min, respectively, while the activation
energies are 64,350 J/mole and 76,571 J/mole. The highest ethanol
concentration from fermentation is 1.13% v/v, attained at 220 0C.
Abstract: Sustainable development is a concept which was
originated in Burtland commission in 1978. Although this concept
was born with environmental aspects, it is penetrated in all areas
rapidly, turning into a dominate view of planning. Concentrating on
future generation issue, especially when talking about heritage has a
long story. Each approach with all of its characteristics illustrates
differences in planning, hence planning always reflects the dominate
idea of its age. This paper studies sustainable development in
planning for historical cities with the aim of finding ways to deal
with heritage in planning for historical cities in Iran. Through this, it
will be illustrated how challenges between sustainable concept and
heritage could be concluded in planning.
Consequently, the paper will emphasize on:
Sustainable development in city planning
Trends regarding heritage
Challenges due to planning for historical cities in Iran
For the first two issues, documentary method regarding the
sustainable development and heritage literature is considered. As the
next step focusing on Iranian historical cities require considering the
urban planning and management structure and identifying the main
challenges related to heritage, so analyzing challenges regarding
heritage is considered. As the result it would be illustrated that key
issue in such planning is active conservation to improve and use the
potential of heritage while it's continues conservation is guaranteed.
By emphasizing on the planning system in Iran it will be obvious that
some reforms are needed in this system and its way of relating with
heritage. The main weakness in planning for historical cities in Iran
is the lack of independent city management. Without this factor
achieving active conservation as the main factor of sustainable
development would not be possible.
Abstract: The paper contains an investigation of zeros Of Bargmann analytic representation. A brief introduction to Harmonic oscillator formalism is given. The Bargmann analytic representation has been studied. The zeros of Bargmann analytic function are considered. The Q or Husimi functions are introduced. The The Bargmann functions and the Husimi functions have the same zeros. The Bargmann functions f(z) have exactly q zeros. The evolution time of the zeros μn are discussed. Various examples have been given.
Abstract: In this paper, the wear of high speed steel hobs during
hobbing has been studied. The wear mechanisms are strongly
influenced by the choice of cutting speed. At moderate and high
cutting speeds three major wear mechanisms were identified:
abrasion, mild adhesive and severe adhesive. The microstructure and
wear behavior of two high speed steel grades (M2 and ASP30) has
been compared. In contrast, a variation in chemical composition or
microstructure of HSS tool material generally did not change the
dominant wear mechanism. However, the tool material properties
determine the resistance against the operating wear mechanism and
consequently the tool life. The metallographic analysis and wear
measurement at the tip of hob teeth included scanning electron
microscopy and stereoscope microscopy. Roughness profilometery is
used for measuring the gear surface roughness.
Abstract: A horizontal anaerobic digester was developed and
tested in pilot scale for Korean food waste with high water contents
(>80%). The hydrogen sulfide in the biogas was removed by a
biological desulfurization equipment integrated in the horizontal
digester. A mixer of the horizontal digester was designed to easily
remove the sediment in the bottom and scum layers on surface in the
digester. Experimental result for 120 days of operation of the pilot
plant showed a high removal efficiency of 81.2% for organic
substance and high stability during the whole operation period were
acquired. Also food waste was treated at high organic loading rates
over 4 kg•VS/m3∙day and a methane gas production rate of 0.62
m3/kg•VSremoved was accomplished.
The biological desulfurization equipment inside the horizontal
digester was proven to be an economic and effective method to reduce
the biogas desulfurization cost by removing hydrogen sulfide more
than 90% without external desulfurization equipments.
Abstract: This paper presents a numerical study on surface heat
transfer characteristics of laminar air flows in parallel-plate dimpled
channels. The two-dimensional numerical model is provided by
commercial code FLUENT and the results are obtained for channels
with symmetrically opposing hemi-cylindrical cavities onto both
walls for Reynolds number ranging from 1000 to 2500. The influence
of variations in relative depth of dimples (the ratio of cavity depth to
the cavity curvature diameter), the number of them and the thermophysical
properties of channel walls on heat transfer enhancement is
studied. The results are evident for existence of an optimum value for
the relative depth of dimples in which the largest wall heat flux and
average Nusselt number can be achieved. In addition, the results of
conjugation simulation indicate that the overall influence of the ratio
of wall thermal conductivity to the one of the fluid on heat transfer
rate is not much significant and can be ignored.
Abstract: This article presents a numerical study of the doublediffusive
mixed convection in a vertical channel filled with porous
medium by using non-equilibrium model. The flow is assumed
fully developed, uni-directional and steady state. The controlling
parameters are thermal Rayleigh number (RaT ), Darcy number (Da),
Forchheimer number (F), buoyancy ratio (N), inter phase heat transfer
coefficient (H), and porosity scaled thermal conductivity ratio
(γ). The Brinkman-extended non-Darcy model is considered. The
governing equations are solved by spectral collocation method. The
main emphasize is given on flow profiles as well as heat and solute
transfer rates, when two diffusive components in terms of buoyancy
ratio are in favor (against) of each other and solid matrix and fluid
are thermally non-equilibrium. The results show that, for aiding flow
(RaT = 1000), the heat transfer rate of fluid (Nuf ) increases upto a
certain value of H, beyond that decreases smoothly and converges
to a constant, whereas in case of opposing flow (RaT = -1000),
the result is same for N = 0 and 1. The variation of Nuf in (N,
Nuf )-plane shows sinusoidal pattern for RaT = -1000. For both cases
(aiding and opposing) the flow destabilize on increasing N by inviting
point of inflection or flow separation on the velocity profile. Overall,
the buoyancy force have significant impact on the non-Darcy mixed
convection under LTNE conditions.
Abstract: An optimal control problem for a mathematical model of efficiency of antiviral therapy in hepatitis B virus infections is considered. The aim of the study is to control the new viral production, block the new infection cells and maintain the number of uninfected cells in the given range. The optimal controls represent the efficiency of antiviral therapy in inhibiting viral production and preventing new infections. Defining the cost functional, the optimal control problem is converted into the constrained optimization problem and the first order optimality system is derived. For the numerical simulation, we propose the steepest descent algorithm based on the adjoint variable method. A computer program in MATLAB is developed for the numerical simulations.
Abstract: The Brazilian legislation has only established
diagnostic reference levels (DRLs) in terms of Multiple Scan
Average Dose (MSAD) as a quality control parameter for computed
tomography (CT) scanners. Compliance with DRLs can be verified
by measuring the Computed Tomography Kerma Index (Ca,100) with
a pencil ionization chamber or by obtaining the kerma distribution in
CT scans with radiochromic films or rod shape lithium fluoride
termoluminescent dosimeters (TLD-100). TL dosimeters were used
to record kerma profiles and to determine MSAD values of a Bright
Speed model GE CT scanner. Measurements were done with
radiochromic films and TL dosimeters distributed in cylinders
positioned in the center and in four peripheral bores of a standard
polymethylmethacrylate (PMMA) body CT dosimetry phantom.
Irradiations were done using a protocol for adult chest. The
maximum values were found at the midpoint of the longitudinal axis.
The MSAD values obtained with three dosimetric techniques were
compared.
Abstract: This paper proposes a power-controlled scheduling scheme for devices using a directional antenna in smart home. In the case of the home network using directional antenna, devices can concurrently transmit data in the same frequency band. Accordingly, the throughput increases compared to that of devices using omni-directional antenna in proportional to the number of concurrent transmissions. Also, the number of concurrent transmissions depends on the beamwidth of antenna, the number of devices operating in the network , transmission power, interference and so on. In particular, the less transmission power is used, the more concurrent transmissions occur due to small transmission range. In this paper, we considered sub-optimal scheduling scheme for throughput maximization and power consumption minimization. In the scheme, each device is equipped with a directional antenna. Various beamwidths, path loss components, and antenna radiation efficiencies are considered. Numerical results show that the proposed schemes outperform the scheduling scheme using directional antennas without power control.
Abstract: There are different kinds of online systems on the Internet for people who need support and develop new knowledge. Online communities and Ask the Expert systems are two such systems. In the health care area, the number of users of these systems has increased at a rapid pace. Interactions with medical trained experts take place online, and people with concerns about similar health problems come together to share experiences and advice. The systems are also used as storages and browsed for health information. Over the years, studies have been conducted of the usage of the different systems. However, in what ways the systems can be used together to enhance learning has not been explored. This paper presents results from a study of online health-communities and an Ask the Expert system for people who suffer from overweight. Differences and similarities in regards to posted issues and replies are discussed, and suggestions for a new holistic design of the two systems are presented.
Abstract: Vermicomposting is the conversion of organic waste
into bio-fertilizers through the action of earthworm. This technology
is widely used for organic solid waste management. Waste corn pulp
blended with cow dung manure was vermicomposted over 30 days
using Eisenia fetida earthworms species. pH, temperature, moisture
content, and electrical conductivity were daily monitored. The
feedstock, vermicompost and vermiwash were analyzed for nutrient
composition. The average temperature and moisture content in the
vermi-reactor was 22.5°C and 42.5% respectively. The vermicompost
and vermiwash had an almost neutral pH whilst the electrical
conductivity was 21% higher in the vermicompost. The nitrogen and
potassium content was 57% and 79.6% richer in the vermicompost
respectively compared to the vermiwash. However, the vermiwash
was 84% richer in phosphorous as compared to vermicompost.
Furthermore, the vermiwash was 89.1% and 97.6% richer in Ca and
Mg respectively and was 97.8% richer in Na salts compared to the
vermicompost. The vermiwash also indicated a significantly higher
amount of micronutrients. Both bio-fertilizers were rich in nutrients
specification for fertilizers.
Abstract: The techniques for estimating the adhesive and cohesive strength in high velocity oxy fuel (HVOF) thermal spray coatings have been discussed and compared. The development trend and the last investigation have been studied. We will focus on benefits and limitations of these methods in different process and materials.