Abstract: A design flow of multi-standard down-conversion
CMOS mixers for three modern standards: Global System Mobile,
Digital Enhanced Cordless Telephone and Universal Mobile
Telecommunication Systems is presented. Three active mixer-s
structures are studied. The first is based on the Gilbert cell which
gives a tolerable noise figure and linearity with a low conversion
gain. The second and third structures use the current bleeding and
charge injection techniques in order to increase the conversion gain.
An improvement of about 2 dB of the conversion gain is achieved
without a considerable degradation of the other characteristics. The
models used for noise figure, conversion gain and IIP3 used are
studied. This study describes the nature of trade-offs inherent in such
structures and gives insights that help in identifying which structure
is better for given conditions.
Abstract: For cognitive radio networks, there is a major
spectrum sensing problem, i.e. dynamic spectrum management. It is
an important issue to sense and identify the spectrum holes in
cognitive radio networks. The first-order derivative scheme is usually
used to detect the edge of the spectrum. In this paper, a novel
spectrum sensing technique for cognitive radio is presented. The
proposed algorithm offers efficient edge detection. Then, simulation
results show the performance of the first-order derivative scheme and
the proposed scheme and depict that the proposed scheme obtains
better performance than does the first-order derivative scheme.
Abstract: This work presents a numerical model developed to
simulate the dynamics and vibrations of a multistage tractor gearbox.
The effect of time varying mesh stiffness, time varying frictional
torque on the gear teeth, lateral and torsional flexibility of the shafts
and flexibility of the bearings were included in the model. The model
was developed by using the Lagrangian method, and it was applied to
study the effect of three design variables on the vibration and stress
levels on the gears. The first design variable, module, had little effect
on the vibration levels but a higher module resulted to higher bending
stress levels. The second design variable, pressure angle, had little
effect on the vibration levels, but had a strong effect on the stress
levels on the pinion of a high reduction ratio gear pair. A pressure
angle of 25o resulted to lower stress levels for a pinion with 14 teeth
than a pressure angle of 20o. The third design variable, contact ratio,
had a very strong effect on both the vibration levels and bending
stress levels. Increasing the contact ratio to 2.0 reduced both the
vibration levels and bending stress levels significantly. For the gear
train design used in this study, a module of 2.5 and contact ratio of
2.0 for the various meshes was found to yield the best combination
of low vibration levels and low bending stresses. The model can
therefore be used as a tool for obtaining the optimum gear design
parameters for a given multistage spur gear train.
Abstract: In this paper, we propose a solution to the motion
control problem of a 2-link revolute manipulator arm. We require the
end-effector of the arm to move safely to its designated target in a
priori known workspace cluttered with fixed circular obstacles of
arbitrary position and sizes. Firstly a unique velocity algorithm is
used to move the end-effector to its target. Secondly, for obstacle
avoidance a turning angle is designed, which when incorporated into
the control laws ensures that the entire robot arm avoids any number
of fixed obstacles along its path enroute the target. The control laws
proposed in this paper also ensure that the equilibrium point of the
system is asymptotically stable. Computer simulations of the
proposed technique are presented.
Abstract: This study aimed to develop and initially validate an instrument that measures social competency among tertiary level faculty members. A review of extant literature on social competence was done. The review of extant literature led to the writing of the items in the initial instrument which was evaluated by 11 Subject Matter Experts (SMEs). The SMEs were either educators or psychologists. The results of the evaluations done by the SMEs served as bases for the creation of the pre-try-out instrument used in the first trial-run. Insights from the first trial-run participants led to the development of the main try-out instrument used in the final test administration. One Hundred Forty-one participants from five private Higher Education Institutions (HEIs) in the National Capital Region (NCR) and five private HEIs in Central Luzon in the Philippines participated in the final test administration. The reliability of the instrument was evaluated using Cronbach-s Coefficient Alpha formula and had a Cronbach-s Alpha of 0.92. On the other hand, Factor Analysis was used to evaluate the validity of the instrument and six factors were identified. The development of the final instrument was based on the results of the evaluation of the instrument-s reliability and validity. For purposes of recognition, the instrument was named “Social Competency Inventory for Tertiary Level Faculty Members (SCI-TLFM)."
Abstract: New theory for functionally graded (FG) shell based on expansion of the equations of elasticity for functionally graded materials (GFMs) into Legendre polynomials series has been developed. Stress and strain tensors, vectors of displacements, traction and body forces have been expanded into Legendre polynomials series in a thickness coordinate. In the same way functions that describe functionally graded relations has been also expanded. Thereby all equations of elasticity including Hook-s law have been transformed to corresponding equations for Fourier coefficients. Then system of differential equations in term of displacements and boundary conditions for Fourier coefficients has been obtained. Cases of the first and second approximations have been considered in more details. For obtained boundary-value problems solution finite element (FE) has been used of Numerical calculations have been done with Comsol Multiphysics and Matlab.
Abstract: In this paper, a new Genetic Algorithm (GA) based
methodology is proposed to optimize the Degree of Hybridization
(DOH) in a passenger parallel hybrid car. At first step, target
parameters for the vehicle are decided and then using ADvanced
VehIcle SimulatOR (ADVISOR) software, the variation pattern of
these target parameters, across the different DOHs, is extracted. At
the next step, a suitable cost function is defined and is optimized
using GA. In this paper, also a new technique has been proposed for
deciding the number of battery modules for each DOH, which leads
to a great improvement in the vehicle performance. The proposed
methodology is so simple, fast and at the same time, so efficient.
Abstract: Detecting object in video sequence is a challenging
mission for identifying, tracking moving objects. Background
removal considered as a basic step in detected moving objects tasks.
Dual static cameras placed in front and rear moving platform
gathered information which is used to detect objects. Background
change regarding with speed and direction moving platform, so
moving objects distinguished become complicated. In this paper, we
propose framework allows detection moving object with variety of
speed and direction dynamically. Object detection technique built on
two levels the first level apply background removal and edge
detection to generate moving areas. The second level apply Moving
Areas Filter (MAF) then calculate Correlation Score (CS) for
adjusted moving area. Merging moving areas with closer CS and
marked as moving object. Experiment result is prepared on real scene
acquired by dual static cameras without overlap in sense. Results
showing accuracy in detecting objects compared with optical flow
and Mixture Module Gaussian (MMG), Accurate ratio produced to
measure accurate detection moving object.
Abstract: Chitosan is a biopolymer composed of glucosamine
and N-acetyl glucosamine. Solubility and viscosity pose problems in
some applications. These problems can be overcome with unique
modifications. In this study, firstly, chitosan was modified by caffeic
acid and thioglycolic acid, separately. Then, growing effects of these
modified polymers was observed in U937 cell line. Caffeic acid is a
phenolic compound and its modifications act carcinogenic inhibitors
in drugs. Thiolated chitosans are commonly being used for drugdelivery
systems in various routes, because of enhancing
mucoadhesiveness property. U937 cell line was used model cell for
leukaemia. Modifications were achieved by 1 – 15 % binding range.
Increasing binding ratios showed higher radical-scavenging activity
and reducing cell growth, in compared to native chitosan. Caffeic
acid modifications showed higher radical-scavenging activity than
thiolated chitosans at the same concentrations. Caffeic acid and
thioglycolic acid modifications inhibited growth of U937, effectively.
Abstract: In this study, we present an advanced detection
technique for mass type breast cancer based on texture information
of organs. The proposed method detects the cancer areas in three
stages. In the first stage, the midpoints of mass area are determined
based on AHE (Adaptive Histogram Equalization). In the second
stage, we set the threshold coefficient of homogeneity by using
MLE (Maximum Likelihood Estimation) to compute the uniformity
of texture. Finally, mass type cancer tissues are extracted from the
original image. As a result, it was observed that the proposed
method shows an improved detection performance on dense breast
tissues of Korean women compared with the existing methods. It is
expected that the proposed method may provide additional
diagnostic information for detection of mass-type breast cancer.
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: As a part of routine oesophageal HDR Brachytherapy procedure, treatment planning takes about 45 minutes while patients are under light sedation. Some patients may suffer gagging and/or spasms before the 90-minute brachytherapy procedure complete, and the treatment may need to be aborted. A pre-prepared plan generated before patient’s sedation may reduce the brachytherapy procedure time by 40 minutes. This paper reports rationality and evidence of pre-prepared treatment plans. A retrospective study of 28 patients confirms that pre-prepared plans would be acceptable for all reviewed patients. The rationality is further confirmed by a systemic study with a wide range of applicator curvature and treatment volume. Detailed comparison between CT based treatment plans and pre-prepared plans are discussed. The argument holds for endobronchial HDR brachytherapy too. With the above evidence, pre-prepared plans have been used for all oesophageal and endobronchial HDR brachytherapy cases in our clinic.
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: One of the approaches to democratization is the fostering of civil society organizations. In Africa, civil society organizations did not fully play their role in the continent-s democratization process due to many factors including the repressive regulations imposed on them by governing parties. In Ethiopia, for the first time in the country-s political history, the civil society played a very active role in the 2005 multi-party election. The involvement of the civil society in this election has far-reaching consequences. One of the objectives of this paper is to assess the consequences of such involvement for both the civil society and the political society in the country. The paper also examines the peculiarities of civil society formation in Africa in general, and in Ethiopia in particular by assessing both the “traditional" and “modern" civil society organizations.
Abstract: In this paper, we focus on the use of knowledge bases
in two different application areas – control of systems with unknown
or strongly nonlinear models (i.e. hardly controllable by the classical
methods), and robot motion planning in eight directions. The first
one deals with fuzzy logic and the paper presents approaches for
setting and aggregating the rules of a knowledge base. Te second one
is concentrated on a case-based reasoning strategy for finding the
path in a planar scene with obstacles.
Abstract: Recently, content delivery services have grown rapidly
over the Internet. For ASPs (Application Service Provider) providing
content delivery services, P2P architecture is beneficial to reduce
outgoing traffic from content servers. On the other hand, ISPs are
suffering from the increase in P2P traffic. The P2P traffic is
unnecessarily redundant because the same content or the same
fractions of content are transferred through an inter-ISP link several
times. Subscriber ISPs have to pay a transit fee to upstream ISPs based
on the volume of inter-ISP traffic. In order to solve such problems,
several works have been done for the purpose of P2P traffic reduction.
However, these existing works cannot control the traffic volume of a
certain link. In order to solve such an ISP-s operational requirement,
we propose a method to control traffic volume for a link within a
preconfigured upper bound value. We evaluated that the proposed
method works well by conducting a simulation on a 1,000-user scale.
We confirm that the traffic volume could be controlled at a lower level
than the upper bound for all evaluated conditions. Moreover, our
method could control the traffic volume at 98.95% link usage against
the target value.
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: Several optimization algorithms specifically applied to
the problem of Operation Planning of Hydrothermal Power Systems
have been developed and are used. Although providing solutions to
various problems encountered, these algorithms have some
weaknesses, difficulties in convergence, simplification of the original
formulation of the problem, or owing to the complexity of the
objective function. Thus, this paper presents the development of a
computational tool for solving optimization problem identified and to
provide the User an easy handling. Adopted as intelligent
optimization technique, Genetic Algorithms and programming
language Java. First made the modeling of the chromosomes, then
implemented the function assessment of the problem and the
operators involved, and finally the drafting of the graphical interfaces
for access to the User. The program has managed to relate a coherent
performance in problem resolution without the need for
simplification of the calculations together with the ease of
manipulating the parameters of simulation and visualization of output
results.
Abstract: The purpose of this study is to examine the selfefficacy
and life satisfaction levels of students receiving education in
schools of physical education and sports. The population of the study
consisted 263 students, among which 154 were male and 109 were
female ( X age=19,4905 + 2,5605), that received education in the
schools of physical education and sports of Selcuk University, Inonu
University, Gazi University and Karamanoglu Mehmetbey
University. In order to achieve the purpose of the study, the selfefficacy
scale, which was developed by Jarrusselam and Shwarzer
(1981) [1] and adapted to Turkish by Yesillay (1993) [2], and the
life satisfaction scale, developed by Diener, Emmos, Larsen and
Griffin (1985) [3] and adapted to Turkish by Kokler (1991) [4], were
utilized.For analyzing and interpreting data Kolmogorov-Smirnov
test, t-test and one way anova test were used, while for determining
the difference between the groups Tukey test and Multiple Linear
Regression test were employed and significance was accepted at
P
Abstract: Foodborne Salmonella infections have become a
major problem world wide. Salmonellosis transmitted from fish are
quite common. Established quality control measures exist for export
oriented fish, none exists for fish consumed locally. This study aimed
at characterization of Salmonella isolated from Nile tilapia . The
study was carried out in selected beaches along L. Victoria in
Western Kenya between March and June 2007. One hundred and
twenty fish specimens were collected. Salmonella isolates were
confirmed using serotyping, biochemical testing in addition to malic
acid dehydrogenase (mdh) and fliC gene sequencing. Twenty
Salmonella isolates were confirmed by mdh gene sequencing. Nine
(9) were S. enterica serotype typhimurium, four (4) were S. enterica
Serotype, enteritidis and seven (7) were S. enterica serotype typhi.
Nile tilapia have a role in transmission of Salmonellosis in the study
area, poor sanitation was a major cause of pollution at the beach
inshore waters.