Abstract: Navigation is the processes of monitoring and
controlling the movement of an object from one place to another.
Currently, Global Positioning System (GPS) is the main navigation
system used all over the world for navigation applications. GPS
receiver receives signals from at least three satellites to locate and
display itself. Displayed positioning information is updated
continuously. Update rate is the number of times per second that a
display is illuminated. The speed of update is governed by receiver
update rate. A higher update rate decreases display lag time and
improves distance measurements and tracking especially when
moving on a curvy route. The majority of GPS receivers used
nowadays are updated every second continuously. This period is
considered reasonable for some applications while it is long relatively
for high speed applications. In this paper, the suitability and
feasibility of GPS receiver with different update rates will be
evaluated for various applications according to the level of speed and
update rate needed for particular applications.
Abstract: Fly ash is one of the residues generated in
combustion, and comprises the fine particles that rise with the flue
gases. Ash which does not rise is termed bottom ash [1]. In our
country, it is expected that will be occurred 50 million tons of waste
ash per year until 2020. Released waste from the thermal power
plants is caused very significant problems as known. The fly ashes
can be evaluated by using as adsorbent material.
The purpose of this study is to investigate the possibility of use of
Tuncbilek fly ash like low-cost adsorbents for heavy metal
adsorption. First of all, Tuncbilek fly ash was characterized. For this
purpose; analysis such as sieve analysis, XRD, XRF, SEM and FT-IR
were performed.
Abstract: Hysitron TriboIndenterTM TI 950 system has been
used for studying the local viscoelastic properties of porcine
intervertebral disc end plate by means of nanoscale mechanical
dynamic analysis. The specimen of an endplate was cut from fresh
porcine vertebra dissected from 16 month animal. The lumbar spine
motion segments were dissected and 5 millimeter thick plates of
vertebral body, endplate and annulus fibrosus were prepared for
nanoindentation. The surface of the sample was kept in physiological
solution during nanoindentation experiment. We obtained mechanical
characteristics of different areas of native endplate (endplate middle
and vertebra and annulus fibrosus boundary).
Abstract: The present study investigates numerically the
phenomenon of vortex-shedding and its suppression in twodimensional
mixed convective flow past a square cylinder under the
joint influence of buoyancy and free-stream orientation with respect
to gravity. The numerical experiments have been conducted at a
fixed Reynolds number (Re) of 100 and Prandtl number (Pr) of 0.71,
while Richardson number (Ri) is varied from 0 to 1.6 and freestream
orientation, α, is kept in the range 0o≤ α ≤ 90o, with 0o
corresponding to an upward flow and 90o representing a cross-flow
scenario, respectively. The continuity, momentum and energy
equations, subject to Boussinesq approximation, are discretized using
a finite difference method and are solved by a semi-explicit pressure
correction scheme. The critical Richardson number, leading to the
suppression of the vortex-shedding (Ric), is estimated by using
Stuart-Landau theory at various free-stream orientations and the
neutral curve is obtained in the Ri-α plane. The neutral curve
exhibits an interesting non-monotonic behavior with Ric first
increasing with increasing values of α upto 45o and then decreasing
till 70o. Beyond 70o, the neutral curve again exhibits a sharp
increasing asymptotic trend with Ric approaching very large values
as α approaches 90o. The suppression of vortex shedding is not
observed at α = 90o (cross-flow). In the unsteady flow regime, the
Strouhal number (St) increases with the increase in Richardson
number.
Abstract: The use of polypropylene mesh devices for Pelvic
Organ Prolapse (POP) spread rapidly during the last decade, yet our
knowledge of the mesh-tissue interaction is far from complete. We
aimed to perform a thorough pathological examination of explanted
POP meshes and describe findings that may explain mechanisms of
complications resulting in product excision. We report a spectrum of
important findings, including nerve ingrowth, mesh deformation,
involvement of detrusor muscle with neural ganglia, and
polypropylene degradation. Analysis of these findings may improve
and guide future treatment strategies.
Abstract: Partitions can play a significant role in minimising cochannel
interference of Wireless LANs by attenuating signals across
room boundaries. This could pave the way towards higher density
deployments in home and office environments through spatial
channel reuse. Yet, due to protocol limitations, the latest incantation
of IEEE 802.11 standard is still unable to take advantage of this fact:
Despite having clearly adequate Signal to Interference Ratio (SIR)
over co-channel neighbouring networks in other rooms, its goodput
falls significantly lower than its maximum in the absence of cochannel
interferers. In this paper, we describe how this situation can
be remedied via modest modifications to the standard.
Abstract: The purpose of this study is to investigate the
efficiency of a double-layer roof in collecting solar energy as an
application to the areas such as raising high-end temperature of
organic Rankine cycle (ORC). The by-product of the solar roof is to
reduce building air-conditioning loads. The experimental apparatus
are arranged to evaluate the effects of the solar roof in absorbing solar
energy. The flow channel is basically formed by an aluminum plate on
top of a plywood plate. The geometric configurations in which the
effects of absorbing energy is analyzed include: a bare uncovered
aluminum plate, a glass-covered aluminum plate, a
glass-covered/black-painted aluminum plate, a plate with variable
lengths, a flow channel with stuffed material (in an attempt on
enhancement of heat conduction), and a flow channel with variable
slanted angles. The experimental results show that the efficiency of
energy collection varies from 0.6 % to 11 % for the geometric
configurations mentioned above. An additional study is carried out
using CFD simulation to investigate the effects of fins on the
aluminum plate. It shows that due to vastly enhanced heat conduction,
the efficiency can reach ~23 % if 50 fins are installed on the aluminum
plate. The study shows that a double-layer roof can efficiently absorb
solar energy and substantially reduce building air-conditioning
loads. On the high end of an organic Rankine cycle, a solar pond is
used to replace the warm surface water of the sea as OTEC (ocean
thermal energy conversion) is the driving energy for the ORC. The
energy collected from the double-layered solar roof can be pumped
into the pond and raise the pond temperature as the pond surface area is
equivalently increased by nearly one-fourth of the total area of the
double-layer solar roof. The effect of raising solar pond temperature is
especially prominent if the double-layer solar roofs are installed in a
community area.
Abstract: This study investigates a voltage-controllable liquid crystals lens with a Fresnel zone electrode. When applying a proper voltage on the liquid crystal cell, a Fresnel-zone-distributed electric field is induced to direct liquid crystals aligned in a concentric structure. Owing to the concentrically aligned liquid crystals, a Fresnel lens is formed. We probe the Fresnel liquid crystal lens using a polarized incident beam with a wavelength of 632.8 nm, finding that the diffraction efficiency depends on the applying voltage. A remarkable diffraction efficiency of ~39.5 % is measured at the voltage of 0.9V. Additionally, a dual focus lens is fabricated by attaching a plane-convex lens to the Fresnel liquid crystals cell. The Fresnel LC lens and the dual focus lens may be applied for DVD/CD pick-up head, confocal microscopy system, or electrically-controlling optical systems.
Abstract: Study was conducted to determine the concentration of
copper, cadmium, lead and zinc in Cabomba furcata that found
abundance in Lake Chini. This aquatic plant was collected randomly
within the lake for heavy metal determination. Water quality
measurement was undertaken in situ for temperature, pH,
conductivity and dissolved oksigen using portable multi sensor probe
YSI model 556. The C. furcata was digested using wet digestion
method and heavy metal concentrations were analysed using Atomic
Absorption Spectrometer (AAS) Perkin Elmer 4100B (flame
method). Result of water quality classify Lake Chini between class II
to class III using Malaysian Water Quality Standard. According to
this standard, Lake Chini has moderate quality, which normal for
natural lake. Heavy metal concentrations in C.furcata were low and
found to be lower than the critical toxic value in aquatic plants. Oneway
ANOVA test indicated the heavy metal concentrations in
C.furcata were significantly differ between sampling location. Water
quality and heavy metal concentrations indicates that Lake Chini was
not receives anthropogenic load from nearby activities.
Abstract: The purpose of this study is to introduce a new
interface program to calculate a dose distribution with Monte Carlo method in complex heterogeneous systems such as organs or tissues
in proton therapy. This interface program was developed under
MATLAB software and includes a friendly graphical user interface
with several tools such as image properties adjustment or results display. Quadtree decomposition technique was used as an image
segmentation algorithm to create optimum geometries from Computed Tomography (CT) images for dose calculations of proton
beam. The result of the mentioned technique is a number of nonoverlapped
squares with different sizes in every image. By this way
the resolution of image segmentation is high enough in and near
heterogeneous areas to preserve the precision of dose calculations
and is low enough in homogeneous areas to reduce the number of
cells directly. Furthermore a cell reduction algorithm can be used to combine neighboring cells with the same material. The validation of this method has been done in two ways; first, in comparison with experimental data obtained with 80 MeV proton beam in Cyclotron
and Radioisotope Center (CYRIC) in Tohoku University and second, in comparison with data based on polybinary tissue calibration method, performed in CYRIC. These results are presented in this paper. This program can read the output file of Monte Carlo code while region of interest is selected manually, and give a plot of dose distribution of proton beam superimposed onto the CT images.
Abstract: The algorithms of convex hull have been extensively studied in literature, principally because of their wide range of applications in different areas. This article presents an efficient algorithm to construct approximate convex hull from a set of n points in the plane in O(n + k) time, where k is the approximation error control parameter. The proposed algorithm is suitable for applications preferred to reduce the computation time in exchange of accuracy level such as animation and interaction in computer graphics where rapid and real-time graphics rendering is indispensable.
Abstract: Analytical investigation of the free vibration behavior
of circular functionally graded (FG) plates integrated with two
uniformly distributed actuator layers made of piezoelectric (PZT4)
material on the top and bottom surfaces of the circular FG plate
based on the classical plate theory (CPT) is presented in this paper.
The material properties of the functionally graded substrate plate are
assumed to be graded in the thickness direction according to the
power-law distribution in terms of the volume fractions of the
constituents and the distribution of electric potential field along the
thickness direction of piezoelectric layers is simulated by a quadratic
function. The differential equations of motion are solved analytically
for clamped edge boundary condition of the plate. The detailed
mathematical derivations are presented and Numerical investigations
are performed for FG plates with two surface-bonded piezoelectric
layers. Emphasis is placed on investigating the effect of varying the
gradient index of FG plate on the free vibration characteristics of the
structure. The results are verified by those obtained from threedimensional
finite element analyses.
Abstract: Optimal load shedding (LS) design as an emergency plan is one of the main control challenges posed by emerging new uncertainties and numerous distributed generators including renewable energy sources in a modern power system. This paper presents an overview of the key issues and new challenges on optimal LS synthesis concerning the integration of wind turbine units into the power systems. Following a brief survey on the existing LS methods, the impact of power fluctuation produced by wind powers on system frequency and voltage performance is presented. The most LS schemas proposed so far used voltage or frequency parameter via under-frequency or under-voltage LS schemes. Here, the necessity of considering both voltage and frequency indices to achieve a more effective and comprehensive LS strategy is emphasized. Then it is clarified that this problem will be more dominated in the presence of wind turbines.
Abstract: In this paper, at first we explain about negative
hypergeometric distribution and its properties. Then we use the w-function
and the Stein identity to give a result on the poisson
approximation to the negative hypergeometric distribution in terms of the total variation distance between the negative hypergeometric and
poisson distributions and its upper bound.
Abstract: This research was conducted in the Pua Watershed whereas located in the Upper Nan River Basin in Nan province, Thailand. Nan River basin originated in Nan province that comprises of many tributary streams to produce as inflow to the Sirikit dam provided huge reservoir with the storage capacity of 9510 million cubic meters. The common problems of most watersheds were found i.e. shortage water supply for consumption and agriculture utilizations, deteriorate of water quality, flood and landslide including debris flow, and unstable of riverbank. The Pua Watershed is one of several small river basins that flow through the Nan River Basin. The watershed includes 404 km2 representing the Pua District, the Upper Nan Basin, or the whole Nan River Basin, of 61.5%, 18.2% or 1.2% respectively. The Pua River is a main stream producing all year streamflow supplying the Pua District and an inflow to the Upper Nan Basin. Its length approximately 56.3 kilometers with an average slope of the channel by 1.9% measured. A diversion weir namely Pua weir bound the plain and mountainous areas with a very steep slope of the riverbed to 2.9% and drainage area of 149 km2 as upstream watershed while a mild slope of the riverbed to 0.2% found in a river reach of 20.3 km downstream of this weir, which considered as a gauged basin. However, the major branch streams of the Pua River are ungauged catchments namely: Nam Kwang and Nam Koon with the drainage area of 86 and 35 km2 respectively. These upstream watersheds produce runoff through the 3-streams downstream of Pua weir, Jao weir, and Kang weir, with an averaged annual runoff of 578 million cubic meters. They were analyzed using both statistical data at Pua weir and simulated data resulted from the hydrologic modeling system (HEC–HMS) which applied for the remaining ungauged basins. Since the Kwang and Koon catchments were limited with lack of hydrological data included streamflow and rainfall. Therefore, the mathematical modeling: HEC-HMS with the Snyder-s hydrograph synthesized and transposed methods were applied for those areas using calibrated hydrological parameters from the upstream of Pua weir with continuously daily recorded of streamflow and rainfall data during 2008-2011. The results showed that the simulated daily streamflow and sum up as annual runoff in 2008, 2010, and 2011 were fitted with observed annual runoff at Pua weir using the simple linear regression with the satisfied correlation R2 of 0.64, 062, and 0.59, respectively. The sensitivity of simulation results were come from difficulty using calibrated parameters i.e. lag-time, coefficient of peak flow, initial losses, uniform loss rates, and missing some daily observed data. These calibrated parameters were used to apply for the other 2-ungauged catchments and downstream catchments simulated.
Abstract: The self-organizing map (SOM) model is a well-known neural network model with wide spread of applications. The main characteristics of SOM are two-fold, namely dimension reduction and topology preservation. Using SOM, a high-dimensional data space will be mapped to some low-dimensional space. Meanwhile, the topological relations among data will be preserved. With such characteristics, the SOM was usually applied on data clustering and visualization tasks. However, the SOM has main disadvantage of the need to know the number and structure of neurons prior to training, which are difficult to be determined. Several schemes have been proposed to tackle such deficiency. Examples are growing/expandable SOM, hierarchical SOM, and growing hierarchical SOM. These schemes could dynamically expand the map, even generate hierarchical maps, during training. Encouraging results were reported. Basically, these schemes adapt the size and structure of the map according to the distribution of training data. That is, they are data-driven or dataoriented SOM schemes. In this work, a topic-oriented SOM scheme which is suitable for document clustering and organization will be developed. The proposed SOM will automatically adapt the number as well as the structure of the map according to identified topics. Unlike other data-oriented SOMs, our approach expands the map and generates the hierarchies both according to the topics and their characteristics of the neurons. The preliminary experiments give promising result and demonstrate the plausibility of the method.
Abstract: A way of achieving nanodimentional structural elements in high carbon steel by special kind of heat treatment and cold plastic deformation is being explored. This leads to increasing interlamellar spacing of ferrite-carbide mixture. Decreasing the interlamellar spacing with cooling temperature increasing is determined. Experiments confirm such interlamellar spacing with which high carbon steel demonstrates the highest treatment and hardening capability. Total deformation degree effect on interlamellar spacing value in a ferrite-carbide mixture is obtained. Mechanical experiments results show that high carbon steel after heat treatment and repetitive cold plastic deformation possesses high tensile strength and yield strength keeping good percentage elongation.
Abstract: Groundwater is one of the most important water
resources in Fars province. Based on this study, 95 percent of the
total annual water consumption in Fars is used for agriculture,
whereas the percentages for domestic and industrial uses are 4 and 1
percent, respectively. Population growth, urban and industrial
growth, and agricultural development in Fars have created a
condition of water stress. In this province, farmers and other users are
pumping groundwater faster than its natural replenishment rate,
causing a continuous drop in groundwater tables and depletion of this
resource. In this research variation of groundwater level, their effects
and ways to help control groundwater levels in aquifer of the Kavar-
Maharloo plains in Fars plain were evaluated .Excessive
exploitation of groundwater in this aquifer caused the groundwater
levels fall too fast or to unacceptable levels. The average drawdown
of the groundwater level in this plain were 17 meters during
1995 to 2006. The purpose of this study is to evaluate water level
changes in the Kavar-Maharloo Aquifer in the Fars province in order
to determine the areas of greatest depletion, the cause of depletion,
and predict the remaining life of the aquifer.
Abstract: The study of the Andaman Sea can be studied by
using the oceanic model; therefore the grid covering the study area
should be generated. This research aims to generate grid covering
the Andaman Sea, situated between longitudes 90◦E to 101◦E and
latitudes 1◦N to 18◦N. A horizontal grid is an orthogonal curvilinear
with 87 × 217 grid points. The methods used in this study are
cubic spline and bilinear interpolations. The boundary grid points
are generated by spline interpolation while the interior grid points
have to be specified by bilinear interpolation method. A vertical grid
is sigma coordinate with 15 layers of water column.
Abstract: Both the minimum energy consumption and
smoothness, which is quantified as a function of jerk, are generally
needed in many dynamic systems such as the automobile and the
pick-and-place robot manipulator that handles fragile equipments.
Nevertheless, many researchers come up with either solely
concerning on the minimum energy consumption or minimum jerk
trajectory. This research paper proposes a simple yet very interesting
when combining the minimum energy and jerk of indirect jerks
approaches in designing the time-dependent system yielding an
alternative optimal solution. Extremal solutions for the cost functions
of the minimum energy, the minimum jerk and combining them
together are found using the dynamic optimization methods together
with the numerical approximation. This is to allow us to simulate
and compare visually and statistically the time history of state inputs
employed by combining minimum energy and jerk designs. The
numerical solution of minimum direct jerk and energy problem are
exactly the same solution; however, the solutions from problem of
minimum energy yield the similar solution especially in term of
tendency.