Abstract: In the Top Right Access point Minimum Length Corridor (TRA-MLC) problem [1], a rectangular boundary partitioned into rectilinear polygons is given and the problem is to find a corridor of least total length and it must include the top right corner of the outer rectangular boundary. A corridor is a tree containing a set of line segments lying along the outer rectangular boundary and/or on the boundary of the rectilinear polygons. The corridor must contain at least one point from the boundaries of the outer rectangle and also the rectilinear polygons. Gutierrez and Gonzalez [1] proved that the MLC problem, along with some of its restricted versions and variants, are NP-complete. In this paper, we give a shorter proof of NP-Completeness of TRA-MLC by findig the reduction in the following way.
Abstract: The electrical and structural properties of Hf/Al/Ni/Au
(20/100/25/50 nm) ohmic contact to n-GaN are reported in this study.
Specific contact resistivities of Hf/Al/Ni/Au based contacts have been
investigated as a function of annealing temperature and achieve the
lowest value of 1.09´10-6 Ω·cm2 after annealing at 650 oC in vacuum.
A detailed mechanism of ohmic contact formation is discussed. By
using different chemical analyses, it is anticipated that the formation of
Hf-Al-N alloy might be responsible to form low temperature ohmic
contacts for the Hf-based scheme to n-GaN.
Abstract: A study on the performance of TCP Vegas versus
different TCP variants in homogeneous and heterogeneous wired
networks are performed via simulation experiment using network
simulator (ns-2). This performance evaluation prepared a comparison
medium for the performance evaluation of enhanced-TCP Vegas in
wired network and for wireless network. In homogeneous network,
the performance of TCP Tahoe, TCP Reno, TCP NewReno, TCP
Vegas and TCP SACK are analyzed. In heterogeneous network, the
performances of TCP Vegas against TCP variants are analyzed. TCP
Vegas outperforms other TCP variants in homogeneous wired
network. However, TCP Vegas achieves unfair throughput in
heterogeneous wired network.
Abstract: Simplified coupled engine block-crankshaft models
based on beam theory provide an efficient substitute to engine
simulation in the design process. These models require accurate
definition of the main bearing stiffness. In this paper, an investigation
of this stiffness is presented. The clearance effect is studied using a
smooth bearing model. It is manifested for low shaft displacement.
The hydrodynamic assessment model shows that the oil film has no
stiffness for low loads and it is infinitely rigid for important loads.
The deformation stiffness is determined using a suitable finite
elements model based on real CADs. As a result, a main bearing
behaviour law is proposed. This behaviour law takes into account the
clearance, the hydrodynamic sustention and the deformation stiffness.
It ensures properly the transition from the configuration low rigidity
to the configuration high rigidity.
Abstract: In this paper, we analyze the problem of quasiballistic electron transport in ultra small of mercury -cadmiumtelluride (Hg0.8Cd0.2Te -MCT) n+-n- n+ devices from hydrodynamic point view. From our study, we note that, when the size of the active layer is low than 0.1μm and for low bias application( ( ≥ 9mV), the quasi-ballistic transport has an important effect.
Abstract: In this work the design and characterization of an optoelectronic automated measurement system it is presented. The optoelectronic devices of this system are an optical transmitter, the optical components and the optical receiver, which were selected for a great precision of the system. The mechanical system allows free displacement of the components as well as the devices that generate the movement. The results, length and profile of the objects are display in Lab View.
Abstract: Dengue fever has become a major concern for health
authorities all over the world particularly in the tropical countries.
These countries, in particular are experiencing the most worrying
outbreak of dengue fever (DF) and dengue haemorrhagic fever
(DHF). The DF and DHF epidemics, thus, have become the main
causes of hospital admissions and deaths in Malaysia. This paper,
therefore, attempts to examine the environmental factors that may
influence the recent dengue outbreak. The aim of this study is twofold,
firstly is to establish a statistical model to describe the
relationship between the number of dengue cases and a range of
explanatory variables and secondly, to identify the lag operator for
explanatory variables which affect the dengue incidence the most.
The explanatory variables involved include the level of cloud cover,
percentage of relative humidity, amount of rainfall, maximum
temperature, minimum temperature and wind speed. The Poisson and
Negative Binomial regression analyses were used in this study. The
results of the analyses on the 915 observations (daily data taken from
July 2006 to Dec 2008), reveal that the climatic factors comprising of
daily temperature and wind speed were found to significantly
influence the incidence of dengue fever after 2 and 3 weeks of their
occurrences. The effect of humidity, on the other hand, appears to be
significant only after 2 weeks.
Abstract: Due to insufficient frequency band and tremendous growth of the mobile users, complex computation is needed for the use of resources. Long distance communication began with the introduction of telegraphs and simple coded pulses, which were used to transmit short messages. Since then numerous advances have rendered reliable transfer of information both easier and quicker. Wireless network refers to any type of computer network that is wireless, and is commonly associated with a telecommunications network whose interconnections between nodes is implemented without the use of wires. Wireless network can be broadly categorized in infrastructure network and infrastructure less network. Infrastructure network is one in which we have a base station to serve the mobile users and in the infrastructure less network is one in which no infrastructure is available to serve the mobile users this kind of networks are also known as mobile Adhoc networks. In this paper we have simulated the result for different scenarios with protocols like AODV and DSR; we simulated the result for throughput, delay and receiving traffic in the given scenario.
Abstract: The Information and Communication Technologies
(ICTs), and the Wide World Web (WWW) have fundamentally
altered the practice of teaching and learning world wide. Many
universities, organizations, colleges and schools are trying to apply
the benefits of the emerging ICT. In the early nineties the term
learning object was introduced into the instructional technology
vernacular; the idea being that educational resources could be broken
into modular components for later combination by instructors,
learners, and eventually computes into larger structures that would
support learning [1]. However in many developing countries, the use
of ICT is still in its infancy stage and the concept of learning object
is quite new. This paper outlines the learning object design
considerations for developing countries depending on learning
environment.
Abstract: Total liquid ventilation can support gas exchange in animal models of lung injury. Clinical application awaits further technical improvements and performance verification. Our aim was to develop a liquid ventilator, able to deliver accurate tidal volumes, and a computerized system for measuring lung mechanics. The computer-assisted, piston-driven respirator controlled ventilatory parameters that were displayed and modified on a real-time basis. Pressure and temperature transducers along with a lineal displacement controller provided the necessary signals to calculate lung mechanics. Ten newborn lambs (
Abstract: There are two types of drought as conceptual drought
and operational drought. The three parameters as the beginning, the
end and the degree of severity of the drought can be identifying in
operational drought by average precipitation in the whole region. One
of the methods classified to measure drought is Reconnaissance
Drought Index (RDI). Evapotranspiration is calculated using
Penman-Monteith method by analyzing thirty nine years prolong
climatic data. The evapotranspiration is then utilized in RDI to
classify normalized and standardized RDI. These RDI classifications
led to what kind of drought faced in Bhavnagar region on 12 month
time scale basis. The comparison between actual drought conditions
and RDI method used to find out drought are also illustrated. It can
be concluded that the index results of drought in a particular year are
same in both methods but having different index values where as
severity remain same.
Abstract: The storage of chemical fertilizers in concrete building often leads to durability problems due to chemical attack. The damage of concrete is mostly caused by certain ammonium salts. The main purpose of the research is to investigate the durability properties of concrete being exposed to ammonium nitrate solution. In this investigation, experiments are conducted on concrete type G50 and G60. The leaching process is achieved by the use of 20% concentration solution of ammonium nitrate. The durability properties investigated are water absorption, volume of permeable voids, and sorptivity. Compressive strength, pH value, and degradation depth are measured after a certain period of leaching. A decrease in compressive strength and an increase in porosity are found through the conducted experiments. Apart from that, the experimental data shows that pH value decreases with increased leaching time while the degradation depth of concrete increases with leaching time. By comparing concrete type G50 and G60, concrete type G60 is more resistant to ammonium nitrate attack.
Abstract: New design of a grid for preparation of high density
granules with enhanced mechanical strength by granulation of
dispersed materials is suggested.
A method for hydrodynamic dimensioning of the grid depending
on granulation conditions, hydrodynamic regime of the operation,
dispersity and physicochemical characteristics of the materials to be
granulated was suggested.
The aim of the grid design is to solve the problems arising by the
granulation of disperse materials.
Abstract: Petri Net (PN) has proven to be effective graphical, mathematical, simulation, and control tool for Discrete Event Systems (DES). But, with the growth in the complexity of modern industrial, and communication systems, PN found themselves inadequate to address the problems of uncertainty, and imprecision in data. This gave rise to amalgamation of Fuzzy logic with Petri nets and a new tool emerged with the name of Fuzzy Petri Nets (FPN). Although there had been a lot of research done on FPN and a number of their applications have been anticipated, but their basic types and structure are still ambiguous. Therefore, in this research, an effort is made to categorize FPN according to their structure and algorithms Further, literature review of the applications of FPN in the light of their classifications has been done.
Abstract: In the numerical solution of the forward dynamics of a
multibody system, the positions and velocities of the bodies in the
system are obtained first. With the information of the system state
variables at each time step, the internal and external forces acting on
the system are obtained by appropriate contact force models if the
continuous contact method is used instead of a discrete contact
method. The local deformation of the bodies in contact, represented
by penetration, is used to compute the contact force. The ability and
suitability with current cylindrical contact force models to describe
the contact between bodies with cylindrical geometries with
particular focus on internal contacting geometries involving low
clearances and high loads simultaneously is discussed in this paper.
A comparative assessment of the performance of each model under
analysis for different contact conditions, in particular for very
different penetration and clearance values, is presented. It is
demonstrated that some models represent a rough approximation to
describe the conformal contact between cylindrical geometries
because contact forces are underestimated.
Abstract: Increase in globalization of capital markets brings the
higher requirements on financial information provided for investors
who look for a highly comparable information. Paper deals with the
advantages and limitations of applying International Financial
Reporting Standards (IFRS) in the Czech Republic and Ukraine. As a
greatest limit for full adoption of IFRS shall be acknowledged the
strong connection of continental accounting to tax system and
enormous high administrative burden for IFRS appliers.
Abstract: The main features of NPP-2006/MIR-1200 design are
described. Estimation of individual doses for population under
normal operation and accident conditions is performed for
Leningradskaya NPP – 2 as an example. The radiation effect on
population and environment doesn-t exceed the established
normative limit and is as low as reasonably achievable. NPP-
2006/MIR-1200 design meets all Russian and international
requirements for power units under construction.
Abstract: This paper presents a novel approach for optimal
reconfiguration of radial distribution systems. Optimal
reconfiguration involves the selection of the best set of branches to
be opened, one each from each loop, such that the resulting radial
distribution system gets the desired performance. In this paper an
algorithm is proposed based on simple heuristic rules and identified
an effective switch status configuration of distribution system for the
minimum loss reduction. This proposed algorithm consists of two
parts; one is to determine the best switching combinations in all loops
with minimum computational effort and the other is simple optimum
power loss calculation of the best switching combination found in
part one by load flows. To demonstrate the validity of the proposed
algorithm, computer simulations are carried out on 33-bus system.
The results show that the performance of the proposed method is
better than that of the other methods.
Abstract: The concept of e-Learning is now emerging in Sub Saharan African countries like Tanzania. Due to economic constraints and other social and cultural factors faced by these countries, the use of Information and Communication Technology (ICT) is increasing at a very low pace. The digital divide threat has propelled the Government of Tanzania to put in place the national ICT Policy in 2003 which defines the direction of all ICT activities nationally. Among the main focused areas is the use of ICT in education, since for the development of any country, there is a need of creating knowledge based society. This paper discusses the initiatives made so far to introduce the use of ICT tools to some secondary schools using open source software in e-content development to facilitate a self-learning environment
Abstract: Total liquid ventilation can support gas exchange in animal models of lung injury. Clinical application awaits further technical improvements and performance verification. Our aim was to develop a liquid ventilator, able to deliver accurate tidal volumes, and a computerized system for measuring lung mechanics. The computer-assisted, piston-driven respirator controlled ventilatory parameters that were displayed and modified on a real-time basis. Pressure and temperature transducers along with a lineal displacement controller provided the necessary signals to calculate lung mechanics. Ten newborn lambs (