Abstract: This paper focuses on the development of bond graph
dynamic model of the mechanical dynamics of an excavating mechanism
previously designed to be used with small tractors, which are
fabricated in the Engineering Workshops of Jomo Kenyatta University
of Agriculture and Technology. To develop a mechanical dynamics
model of the manipulator, forward recursive equations similar to
those applied in iterative Newton-Euler method were used to obtain
kinematic relationships between the time rates of joint variables
and the generalized cartesian velocities for the centroids of the
links. Representing the obtained kinematic relationships in bondgraphic
form, while considering the link weights and momenta as
the elements led to a detailed bond graph model of the manipulator.
The bond graph method was found to reduce significantly the number
of recursive computations performed on a 3 DOF manipulator for a
mechanical dynamic model to result, hence indicating that bond graph
method is more computationally efficient than the Newton-Euler
method in developing dynamic models of 3 DOF planar manipulators.
The model was verified by comparing the joint torque expressions
of a two link planar manipulator to those obtained using Newton-
Euler and Lagrangian methods as analyzed in robotic textbooks. The
expressions were found to agree indicating that the model captures
the aspects of rigid body dynamics of the manipulator. Based on
the model developed, actuator sizing and valve sizing methodologies
were developed and used to obtain the optimal sizes of the pistons
and spool valve ports respectively. It was found that using the pump
with the sized flow rate capacity, the engine of the tractor is able to
power the excavating mechanism in digging a sandy-loom soil.
Abstract: This article analyses conspiracy theories as part of the
wider discourses of missionary politics. It presents a case study of
Venezuela and describes how its leaders use conspiracy theories as
political tools. Through quotes taken form Venezuelan president
Chavez-s public speeches and other sources, and through a short
analysis of the ideological basis of his discourses, it shows how
conspiracy theories are constructed and how they affect the local
political praxis. The article also describes how conspiracy theories
have been consistently used as an important part of the construction of
a political religion for the New Man of the Bolivarian Revolution. It
concludes that the use of conspiracy theories by political leaders
produces a sense of loss of political agency.
Abstract: Aggregation behavior of sodium salicylate and sodium cumene sulfonate was studied in aqueous solution at different temperature. Specific conductivity and relative viscosity were measured at different temperature to find minimum hydrotropic concentration. The thermodynamic parameters (free energy, enthalpy and entropy) were evaluated in the temperature range of 30°C-70°C. The free energy decreased with increase in temperature. The aggregation was found to be exothermic in nature and favored by positive value of entropy.
Abstract: 98% of the energy needed in Taiwan has been
imported. The prices of petroleum and electricity have been
increasing. In addition, facility capacity, amount of electricity
generation, amount of electricity consumption and number of Taiwan
Power Company customers have continued to increase. For these
reasons energy conservation has become an important topic. In the
past linear regression was used to establish the power consumption
models for chillers. In this study, grey prediction is used to evaluate
the power consumption of a chiller so as to lower the total power
consumption at peak-load (so that the relevant power providers do not
need to keep on increasing their power generation capacity and facility
capacity).
In grey prediction, only several numerical values (at least four
numerical values) are needed to establish the power consumption
models for chillers. If PLR, the temperatures of supply chilled-water
and return chilled-water, and the temperatures of supply cooling-water
and return cooling-water are taken into consideration, quite accurate
results (with the accuracy close to 99% for short-term predictions)
may be obtained. Through such methods, we can predict whether the
power consumption at peak-load will exceed the contract power
capacity signed by the corresponding entity and Taiwan Power
Company. If the power consumption at peak-load exceeds the power
demand, the temperature of the supply chilled-water may be adjusted
so as to reduce the PLR and hence lower the power consumption.
Abstract: In this paper, center conditions and bifurcation of limit cycles at the nilpotent critical point in a class of quintic polynomial differential system are investigated.With the help of computer algebra system MATHEMATICA, the first 10 quasi Lyapunov constants are deduced. As a result, sufficient and necessary conditions in order to have a center are obtained. The fact that there exist 10 small amplitude limit cycles created from the three order nilpotent critical point is also proved. Henceforth we give a lower bound of cyclicity of three-order nilpotent critical point for quintic Lyapunov systems. At last, we give an system which could bifurcate 10 limit circles.
Abstract: In this paper, naturally immobilized lipase, Carica
papaya lipase, catalyzed biodiesel production from fish oil was
studied. The refined fish oil, extracted from the discarded parts of
fish, was used as a starting material for biodiesel production. The
effects of molar ratio of oil: methanol, lipase dosage, initial water
activity of lipase, temperature and solvent were investigated. It was
found that Carica papaya lipase was suitable for methanolysis of fish
oil to produce methyl ester. The maximum yield of methyl ester
could reach up to 83% with the optimal reaction conditions: oil:
methanol molar ratio of 1: 4, 20% (based on oil) of lipase, initial
water activity of lipase at 0.23 and 20% (based on oil) of tert-butanol
at 40oC after 18 h of reaction time. There was negligible loss in
lipase activity even after repeated use for 30 cycles.
Abstract: The purpose of this study is to suggest direction for
future study of the energy-IT industry that will be used for framework to increase IT utilization in the energy industry. Recently, Green IT is a becoming global issue because of global environmental pollution.
Also, IT roles in energy industry are becoming more important.
However, the related studies were IT industry oriented that is not sufficient to make plan for Green energy. Therefore, after analyzing
existing studies related to Green energy and Green IT,
re-categorization for Green energy-IT industry was suggested. Direction of framework is based on energy industry that enable to link between energy and IT. The results of this study suggest comprehensive insight to Green energy-IT industry. Thus it is able to
provide useful implications and guidelines to increase IT utilization in the energy industry.
Abstract: Tasks of an application program of an embedded system are managed by the scheduler of a real-time operating system
(RTOS). Most RTOSs adopt just fixed priority scheduling, which is not optimal in all cases. Some applications require earliest deadline
first (EDF) scheduling, which is an optimal scheduling algorithm.
In order to develop an efficient real-time embedded system, the
scheduling algorithm of the RTOS should be selectable. The paper presents a method to customize the scheduler using aspectoriented
programming. We define aspects to replace the fixed priority scheduling mechanism of an OSEK OS with an EDF scheduling
mechanism. By using the aspects, we can customize the scheduler
without modifying the original source code. We have applied the
aspects to an OSEK OS and get a customized operating system with
EDF scheduling. The evaluation results show that the overhead of
aspect-oriented programming is small enough.
Abstract: In this paper we present a linear autozeroing ultra lowvoltage amplifier. The autozeroing performed by all ULV circuits is important to reduce the impact of noise and especially avoid power supply noise in mixed signal low-voltage CMOS circuits. The simulated data presented is relevant for a 90nm TSMC CMOS process.
Abstract: RFID tag is a small and inexpensive microchip which is
capable of transmitting unique identifier through wireless network in a
short distance. If a group of RFID tags can be scanned simultaneously
by one reader, RFID Group proof could be generated. Group proof can
be used in various applications, such as good management which is
usually achieved using barcode system. A lot of RFID group proof
schemes have been proposed by many researchers. In this paper, we
introduce some existing group proof schemes and then analyze their
vulnerabilities to the privacy. Moreover, we propose a new attack
model, which threats the privacy of user by tracking tags in a group.
Abstract: Software organizations are constantly looking for
better solutions when designing and using well-defined software
processes for the development of their products and services.
However, while the technical aspects are virtually easier to arrange,
many software development processes lack more support on project
management issues. When adopting such processes, an organization
needs to apply good project management skills along with technical
views provided by those models. This research proposes the
definition of a new model that integrates the concepts of PMBOK
and those available on the OPEN metamodel, helping not only
process integration but also building the steps towards a more
comprehensive and automatable model.
Abstract: This paper will first describe predictor controllers
when the proportional-integral-derivative (PID) controllers are
inactive for procedures that have large delay time (LDT) in transfer
stage. Therefore in those states, the predictor controllers are better
than the PID controllers, then compares three types of predictor
controllers. The value of these controller-s parameters are obtained
by trial and error method, so here an effort has been made to obtain
these parameters by Ziegler-Nichols method. Eventually in this paper
Ziegler-Nichols method has been described and finally, a PIP
controller has been designed for a thermal system, which circulates
hot air to keep the temperature of a chamber constant.
Abstract: This paper presents the effect of driving a motor
vehicle on the stress levels of older drivers, indicated by monitoring
their hear rate increase whilst completing various everyday driving
tasks. Results suggest that whilst older female drivers heart rate varied
more significantly than males, the actual age of a participant did not
result in a significant change in heart rate due to stress, within the age
group tested. The analysis of the results indicates the most stressful
manoeuvres undertaken by the older drivers and highlights the tasks
which were found difficult with a view to implementing technologies
to aid the more senior driver in automotive travel.
Abstract: SeqWord Gene Island Sniffer, a new program for
the identification of mobile genetic elements in sequences of bacterial chromosomes is presented. This program is based on the
analysis of oligonucleotide usage variations in DNA sequences. 3,518 mobile genetic elements were identified in 637 bacterial
genomes and further analyzed by sequence similarity and the
functionality of encoded proteins. The results of this study are stored in an open database http://anjie.bi.up.ac.za/geidb/geidbhome.
php). The developed computer program and the database provide the information valuable for further investigation of the
distribution of mobile genetic elements and virulence factors among bacteria. The program is available for download at www.bi.up.ac.za/SeqWord/sniffer/index.html.
Abstract: We report in this paper the model adopted by our
system of continuous speech recognition in Arab language SySRA
and the results obtained until now. This system uses the database
Arabdic-10 which is a corpus of word for the Arab language and
which was manually segmented. Phonetic decoding is represented
by an expert system where the knowledge base is translated in the
form of production rules. This expert system transforms a vocal
signal into a phonetic lattice. The higher level of the system takes
care of the recognition of the lattice thus obtained by deferring it in
the form of written sentences (orthographical Form). This level
contains initially the lexical analyzer which is not other than the
module of recognition. We subjected this analyzer to a set of
spectrograms obtained by dictating a score of sentences in Arab
language. The rate of recognition of these sentences is about 70%
which is, to our knowledge, the best result for the recognition of the
Arab language. The test set consists of twenty sentences from four
speakers not having taken part in the training.
Abstract: In this paper we promote the Ultra Low Voltage (ULV) NAND gate to replace either partly or entirely the encryption block of a design to withstand power analysis attack.
Abstract: A passive system "Qanat" is collection of some
underground wells. A mother-well was dug in a place far from the
city where they could reach to the water table maybe 100 meters
underground, they dug other wells to direct water toward the city,
with minimum possible gradient. Using the slope of the earth they
could bring water close to the surface in the city. The source of water
or the appearance of Qanat, land slope and the ownership lines are
the important and effective factors in the formation of routes and the
segment division of lands to the extent that making use of Qanat as
the techniques of extracting underground waters creates a channel of
routes with an organic order and hierarchy coinciding the slope of
land and it also guides the Qanat waters in the tradition texture of salt
desert and border provinces of it. Qanats are excavated in a specified
distinction from each other. The quantity of water provided by
Qanats depends on the kind of land, distance from mountain,
geographical situation of them and the rate of water supply from the
underground land. The rate of underground waters, possibility of
Qanat excavation, number of Qanats and rate of their water supply
from one hand and the quantity of cultivable fertile lands from the
other hand are the important natural factors making the size of cities.
In the same manner the cities with several Qanats have multi central
textures. The location of cities is in direct relation with land quality,
soil fertility and possibility of using underground water by excavating
Qanats. Observing the allowable distance for Qanat watering is a
determining factor for distance between villages and cities.
Topography, land slope, soil quality, watering system, ownership,
kind of cultivation, etc. are the effective factors in directing Qanats
for excavation and guiding water toward the cultivable lands and it
also causes the formation of different textures in land division of
farming provinces. Several divisions such as orderly and wide, inorderly,
thin and long, comb like, etc. are the introduction to organic
order. And at the same time they are complete coincidence with
environmental conditions in the typical development of ecological
architecture and planning in the traditional cities and settlements
order.
Abstract: This study aims to segment objects using the K-means
algorithm for texture features. Firstly, the algorithm transforms color
images into gray images. This paper describes a novel technique for
the extraction of texture features in an image. Then, in a group of
similar features, objects and backgrounds are differentiated by using
the K-means algorithm. Finally, this paper proposes a new object
segmentation algorithm using the morphological technique. The
experiments described include the segmentation of single and multiple
objects featured in this paper. The region of an object can be
accurately segmented out. The results can help to perform image
retrieval and analyze features of an object, as are shown in this paper.
Abstract: In this paper, a novel scheme is proposed for ownership identification and authentication using color images by deploying Cryptography and Digital Watermarking as underlaying technologies. The former is used to compute the contents based hash and the latter to embed the watermark. The host image that will claim to be the rightful owner is first transformed from RGB to YST color space exclusively designed for watermarking based applications. Geometrically YS ÔèÑ T and T channel corresponds to the chrominance component of color image, therefore suitable for embedding the watermark. The T channel is divided into 4×4 nonoverlapping blocks. The size of block is important for enhanced localization, security and low computation. Each block along with ownership information is then deployed by SHA160, a one way hash function to compute the content based hash, which is always unique and resistant against birthday attack instead of using MD5 that may raise the condition i.e. H(m)=H(m'). The watermark payload varies from block to block and computed by the variance factorα . The quality of watermarked images is quite high both subjectively and objectively. Our scheme is blind, computationally fast and exactly locates the tampered region.
Abstract: In this research, we study a control method of a multivehicle
system while considering the limitation of communication
range for each vehicles. When we control networked vehicles with
limitation of communication range, it is important to control the
communication network structure of a multi-vehicle system in order
to keep the network-s connectivity. From this, we especially aim to
control the network structure to the target structure. We formulate
the networked multi-vehicle system with some disturbance and the
communication constraints as a hybrid dynamical system, and then
we study the optimal control problems of the system. It is shown
that the system converge to the objective network structure in finite
time when the system is controlled by the receding horizon method.
Additionally, the optimal control probrems are convertible into the
mixed integer problems and these problems are solvable by some
branch and bound algorithm.