Abstract: In this paper methodology to exploit creeping wave
for body area network BAN communication reliability are described.
Creeping wave propagation effects are visualized & analyzed.
During this work Dipole, IA antennas various antennas were
redesigned using existing designs and their propagation
characteristics were verified for optimum performance when used on
BANs. These antennas were then applied on body shapes-including
rectangular, spherical and cylindrical so that all the effects of actual
human body can be taken nearly into account. Parametric simulation
scheme was devised so that on Body channel characterization can be
visualized at front, curved and back region. In the next phase
multiple inputs multiple output MIMO scheme was introduced where
virtual antennas were used in order to diminish the effects of
antennas on the propagation of waves. Results were, extracted and
analyzed at different heights. Finally based on comparative
measurement and analysis it was concluded that on body propagation
can be exploited to gain spatial diversity.
Abstract: Circular tubes have been widely used as structural
members in engineering application. Therefore, its collapse behavior
has been studied for many decades, focusing on its energy absorption
characteristics. In order to predict the collapse behavior of members,
one could rely on the use of finite element codes or experiments.
These tools are helpful and high accuracy but costly and require
extensive running time. Therefore, an approximating model of tubes
collapse mechanism is an alternative for early step of design. This
paper is also aimed to develop a closed-form solution of thin-walled
circular tube subjected to bending. It has extended the Elchalakani et
al.-s model (Int. J. Mech. Sci.2002; 44:1117-1143) to include the
rate of energy dissipation of rolling hinge in the circumferential
direction. The 3-D geometrical collapse mechanism was analyzed by
adding the oblique hinge lines along the longitudinal tube within the
length of plastically deforming zone. The model was based on the
principal of energy rate conservation. Therefore, the rates of internal
energy dissipation were calculated for each hinge lines which are
defined in term of velocity field. Inextensional deformation and
perfect plastic material behavior was assumed in the derivation of
deformation energy rate. The analytical result was compared with
experimental result. The experiment was conducted with a number of
tubes having various D/t ratios. Good agreement between analytical
and experiment was achieved.
Abstract: Congestion control is one of the fundamental issues in computer networks. Without proper congestion control mechanisms there is the possibility of inefficient utilization of resources, ultimately leading to network collapse. Hence congestion control is an effort to adapt the performance of a network to changes in the traffic load without adversely affecting users perceived utilities. AIMD (Additive Increase Multiplicative Decrease) is the best algorithm among the set of liner algorithms because it reflects good efficiency as well as good fairness. Our control model is based on the assumption of the original AIMD algorithm; we show that both efficiency and fairness of AIMD can be improved. We call our approach is New AIMD. We present experimental results with TCP that match the expectation of our theoretical analysis.
Abstract: Nigella sativa L. is an aromatic plant belonging to the
family Ranunculaceae. It has been used traditionally, especially in the
middle East and India, for the treatment of asthma, cough, bronchitis,
headache, rheumatism, fever, influenza and eczema. Several
biological activities have been reported in Nigella sativa seeds,
including antioxidant. In this context we tried to estimate the
antioxidant activity of various extracts prepared from Nigella sativa
seeds, methanolic extract (ME), chloroformic extract (CE), hexanic
extract (HE : fixed oil), ethyl acetate extract (EAE) water extract
(WE). The Folin-Ciocalteu assay showed that CE and EAE contained
high level of phenolic compounds 81.31 and 72.43μg GAE/mg of
extract respectively. Similarly, the CE and EAE exhibited the highest
DPPH radical scavenging activity, with IC50 values of 106.56μg/ml
and 121.62μg/ml respectively. In addition, CE and HE showed the
most scavenging activity against superoxide radical generated in the
PMS-NADH-NBT system with respective IC50 values of 361.86
μg/ml and 371.80 μg/ml, which is comparable to the activity of the
standard antioxidant BHT (344.59 μg/ml). Ferrous ion chelating
capacity assay showed that WE, EAE and ME are the most active
with 40.57, 39.70 and 22.02 mg EDTA-E/g of extract. The inhibition
of linoleic acid/ß-carotene coupled oxidation was estimated by ßcarotene
bleaching assay, this showed a highest relative antioxidant
activity with CE and EAE (69.82% of inhibition). The antioxidant
activities of the methanolic extract and the fixed oil are confirmed by
an in vivo assay in mice, the daily oral administration of methanolic
extract (500 and 800 mg/kg/day) and fixed oil (2 and 4 ml/kg/day)
during 21 days, resulted in a significant enhancement of the blood
total antioxidant capacity (measured by KRL test) and the plasmatic
antioxidant capacity towards DPPH radical.
Abstract: This paper has as its main aim to analyse how
corporate web pages can become an essential tool in order to detect
strategic trends by firms or sectors, and even a primary source for
benchmarking. This technique has made it possible to identify the key
issues in the strategic management of the most excellent large Spanish
firms and also to describe trends in their long-range planning, a way of
working that can be generalised to any country or firm group. More
precisely, two objectives were sought. The first one consisted in showing
the way in which corporate websites make it possible to obtain direct
information about the strategic variables which can define firms. This
tool is dynamic (since web pages are constantly updated) as well as
direct and reliable, since the information comes from the firm itself, not
from comments of third parties (such as journalists, academicians,
consultants...). When this information is analysed for a group of firms,
one can observe their characteristics in terms of both managerial tasks
and business management. As for the second objective, the methodology
proposed served to describe the corporate profile of the large Spanish
enterprises included in the Ibex35 (the Ibex35 or Iberia Index is the
reference index in the Spanish Stock Exchange and gathers periodically
the 35 most outstanding Spanish firms). An attempt is therefore made to
define the long-range planning that would be characteristic of the largest
Spanish firms.
Abstract: The objective of this study was to evaluate the
distribution patterns of Cd, Zn and Hg in groundwater by geospatial
interpolation. The study was performed at Rayong province in the
eastern part of Thailand, with high agricultural and industrial
activities. Groundwater samples were collected twice a year from 31
tubewells around this area. Inductively Coupled Plasma-Atomic
Emission Spectrometer (ICP-AES) was used to measure the
concentrations of Cd, Zn, and Hg in groundwater samples. The
results demonstrated that concentrations of Cd, Zn and Hg range
from 0.000-0.297 mg/L (x = 0.021±0.033 mg/L), 0.022-33.236 mg/L
(x = 4.214±4.766 mg/L) and 0.000-0.289 mg/L (x = 0.023±0.034
mg/L), respectively. Most of the heavy metals concentrations were
exceeded groundwater quality standards as specified in the Ministry
of Natural Resources and Environment, Thailand. The trend
distribution of heavy metals were high concentrations at the
southeastern part of the area that especially vulnerable to heavy
metals and other contaminants.
Abstract: Jayanti-s algorithm is one of the best known abortable mutual exclusion algorithms. This work is an attempt to overcome an already known limitation of the algorithm while preserving its all important properties and elegance. The limitation is that the token number used to assign process identification number to new incoming processes is unbounded. We have used a suitably adapted alternative data structure, in order to completely eliminate the use of token number, in the algorithm.
Abstract: Recently, we have presented an initial implementation
of a model agent-based e-commerce system, which utilized a simple
price negotiation mechanism–English Auction. In this note we
discuss how a Dutch Auction involving multiple units of a product
can be included in our system. We present UML diagrams of
agents involved in price negotiations and briefly discuss rule-based
mechanism exemplifying Dutch Auction.
Abstract: III-nitride quaternary InxAlyGa1-x-yN alloys have experienced considerable interest as potential materials for optoelectronic applications. Despite these interesting applications and the extensive efforts to understand their fundamental properties, research on its fundamental surface property, i.e., surface phonon polariton (SPP) has not yet been reported. In fact, the SPP properties have been shown to provide application for some photonic devices. Hence, there is an absolute need for thorough studies on the SPP properties of this material. In this work, theoretical study on the SPP modes in InAlGaN quaternary alloys are reported. Attention is focus on the wurtzite (α-) structure InxAlyGa1-x-yN semi-crystal with different In composition, x ranging from 0 to 0.10 and constant Al composition, y = 0.06. The SPP modes are obtained through the theoretical simulation by means of anisotropy model. The characteristics of SP dispersion curves are discussed. Accessible results in terms of the experimental point of view are also given. Finally, the results revealed that the SPP mode of α-InxAlyGa1-x-yN semiconductors exhibits two-mode behavior.
Abstract: The machining of Carbon Fiber Reinforced Plastics
has come to constitute a significant challenge for many fields of
industry. The resulting surface finish of machined parts is of primary
concern for several reasons, including contact quality and impact on
the assembly. Therefore, the characterization and prediction of
roughness based on machining parameters are crucial for costeffective
operations. In this study, a PCD tool comprised of two
straight flutes was used to trim 32-ply carbon fiber laminates in a bid
to analyze the effects of the feed rate and the cutting speed on the
surface roughness. The results show that while the speed has but a
slight impact on the surface finish, the feed rate for its part affects it
strongly. A detailed study was also conducted on the effect of fiber
orientation on surface roughness, for quasi-isotropic laminates used
in aerospace. The resulting roughness profiles for the four-ply
orientation lay-up were compared, and it was found that fiber angle is
a critical parameter relating to surface roughness. One of the four
orientations studied led to very poor surface finishes, and
characteristic roughness profiles were identified and found to only
relate to the ply orientations of multilayer carbon fiber laminates.
Abstract: Unstructured peer-to-peer networks are popular due to
its robustness and scalability. Query schemes that are being used in
unstructured peer-to-peer such as the flooding and interest-based
shortcuts suffer various problems such as using large communication
overhead long delay response. The use of routing indices has been a
popular approach for peer-to-peer query routing. It helps the query
routing processes to learn the routing based on the feedbacks
collected. In an unstructured network where there is no global
information available, efficient and low cost routing approach is
needed for routing efficiency.
In this paper, we propose a novel mechanism for query-feedback
oriented routing indices to achieve routing efficiency in unstructured
network at a minimal cost. The approach also applied information
retrieval technique to make sure the content of the query is
understandable and will make the routing process not just based to
the query hits but also related to the query content. Experiments have
shown that the proposed mechanism performs more efficient than
flood-based routing.
Abstract: The pyrolysis characteristics and kinetics of seven marine biomass, which are fixed Enteromorpha clathrata, floating Enteromorpha clathrata, Ulva lactuca L., Zosterae Marinae L., Thallus Laminariae, Asparagus schoberioides kunth and Undaria pinnatifida (Harv.), were studied with thermogravimetric analysis method. Simultaneously, cornstalk, which is a grass biomass, and sawdust, which is a lignocellulosic biomass, were references. The basic pyrolysis characteristics were studied by using TG- DTG-DTA curves. The results showed that there were three stages (dehydration, dramatic weight loss and slow weight loss) during the whole pyrolysis process of samples. The Tmax of marine biomass was significantly lower than two kinds of terrestrial biomass. Zosterae Marinae L. had a relatively high stability of pyrolysis, but floating Enteromorpha clathrata had lowest stability of pyrolysis and a good combustion characteristics. The corresponding activation energy E and frequency factor A were obtained by Coats-Redfern method. It was found that the pyrolysis reaction mechanism functions of three kinds of biomass are different.
Abstract: This paper presents a new type of mechanism and trajectory planning strategy for bipedal walking robot. The newly designed mechanism is able to improve the performance of bipedal walking robot in terms of energy efficiency and weight reduction by utilizing minimum number of actuators. The usage of parallelogram mechanism eliminates the needs of having an extra actuator at the knee joint. This mechanism works together with the joint space trajectory planning in order to realize straight legged walking which cannot be achieved by conventional inverse kinematics trajectory planning due to the singularity. The effectiveness of the proposed strategy is confirmed by computer simulation results.
Abstract: Capacity and efficiency of any refrigerating system
diminish rapidly as the difference between the evaporating and
condensing temperature is increased by reduction in the evaporator
temperature. The single stage vapour compression refrigeration
system is limited to an evaporator temperature of -40 0C. Below
temperature of -40 0C the either cascade refrigeration system or multi
stage vapour compression system is employed. Present work
describes thermal design of main three heat exchangers namely
condenser (HTS), cascade condenser and evaporator (LTS) of
R404A-R508B and R410A-R23 cascade refrigeration system. Heat
transfer area of condenser (HTS), cascade condenser and evaporator
(LTS) for both systems have been compared and the effect of
condensing and evaporating temperature on heat-transfer area for
both systems have been studied under same operating condition. The
results shows that the required heat-transfer area of condenser and
cascade condenser for R410A-R23 cascade system is lower than the
R404A-R508B cascade system but heat transfer area of evaporator is
similar for both the system. The heat transfer area of condenser and
cascade condenser decreases with increase in condensing temperature
(Tc), whereas the heat transfer area of cascade condenser and
evaporator increases with increase in evaporating temperature (Te).
Abstract: A new and highly efficient architecture for elliptic curve scalar point multiplication which is optimized for a binary field recommended by NIST and is well-suited for elliptic curve cryptographic (ECC) applications is presented. To achieve the maximum architectural and timing improvements we have reorganized and reordered the critical path of the Lopez-Dahab scalar point multiplication architecture such that logic structures are implemented in parallel and operations in the critical path are diverted to noncritical paths. With G=41, the proposed design is capable of performing a field multiplication over the extension field with degree 163 in 11.92 s with the maximum achievable frequency of 251 MHz on Xilinx Virtex-4 (XC4VLX200) while 22% of the chip area is occupied, where G is the digit size of the underlying digit-serial finite field multiplier.
Abstract: Three batches of yogurts were made with soy protein
isolate (SPI) supplemented with 2% (S2), 4% (S4) or 6% (S6) of
skim milk powder (SMP). The fourth batch (control; S0) was
prepared from SPI without SMP supplementation. Lactobacillus
delbrueckii ssp. bulgaricus ATCC 11842 (Lb 11842) and
Streptococcus thermophilus ST 1342 (ST 1342) were used as the
starter culture. Biotransformation of the inactive forms, isoflavone
glycosides (IG) to biologically active forms, isoflavone aglycones
(IA), was determined during 28 d storage. The viability of both
microorganisms was significantly higher (P < 0.05) in S2, S4, and S6
than that in S0. The ratio of lactic acid/acetic acid in S0 was in the
range of 15.53 – 22.31 compared to 7.24 – 12.81 in S2, S4 and S6.
The biotransformation of IG to IA in S2, S4 and S6 was also
enhanced by 9.9 -13.3% compared to S0.
Abstract: Categorical data based on description of the
agricultural landscape imposed some mathematical and analytical
limitations. This problem however can be overcome by data
transformation through coding scheme and the use of non-parametric
multivariate approach. The present study describes data
transformation from qualitative to numerical descriptors. In a
collection of 103 random soil samples over a 60 hectare field,
categorical data were obtained from the following variables: levels of
nitrogen, phosphorus, potassium, pH, hue, chroma, value and data on
topography, vegetation type, and the presence of rocks. Categorical
data were coded, and Spearman-s rho correlation was then calculated
using PAST software ver. 1.78 in which Principal Component
Analysis was based. Results revealed successful data transformation,
generating 1030 quantitative descriptors. Visualization based on the
new set of descriptors showed clear differences among sites, and
amount of variation was successfully measured. Possible applications
of data transformation are discussed.
Abstract: In an electric power system, spinning reserve
requirements can be determined by using deterministic and/or
probabilistic measures. Although deterministic methods are usual in
many systems, application of probabilistic methods becomes
increasingly important in the new environment of the electric power
utility industry. This is because of the increased uncertainty
associated with competition. In this paper 1) a new probabilistic
method is presented which considers the reliability of transmission
system in a simplified manner and 2) deterministic and probabilistic
methods are compared. The studied methods are applied to the Roy
Billinton Test System (RBTS).
Abstract: In this paper, perceptions of actors on changes in
crop productivity, quantity and quality of water, and determinants of
their perception are analyzed using descriptive statistics and ordered
logit model. Data collected from 297 Ethiopian farmers and 103
agricultural professionals from December 2009 to January 2010 are
employed. Results show that the majority of the farmers and
professionals recognized decline in water resources, reasoning
climate changes and soil erosion as some of the causes. However,
there is a variation in views on changes in productivity. The
household asset, education level, age and geographical positions are
found to affect farmers- perception on changes in crop productivity.
But, the study underlines that there is no evidence that farmers-
economic status, age, or education level affects recognition of
degradation of water resources. Thus, more focus shall be given on
providing them different coping mechanisms and alternative
resource conserving technologies than educating about the
problems.
Abstract: Supply chain consists of all stages involved, directly
or indirectly, includes all functions involved in fulfilling a customer
demand. In two stage transportation supply chain problem,
transportation costs are of a significant proportion of final product
costs. It is often crucial for successful decisions making approaches
in two stage supply chain to explicit account for non-linear
transportation costs. In this paper, deterministic demand and finite
supply of products was considered. The optimized distribution level
and the routing structure from the manufacturing plants to the
distribution centres and to the end customers is determined using
developed mathematical model and solved by proposed particle
swarm optimization based genetic algorithm. Numerical analysis of
the case study is carried out to validate the model.