Abstract: Symbolic Circuit Analysis (SCA) is a technique used
to generate the symbolic expression of a network. It has become a
well-established technique in circuit analysis and design. The
symbolic expression of networks offers excellent way to perform
frequency response analysis, sensitivity computation, stability
measurements, performance optimization, and fault diagnosis. Many
approaches have been proposed in the area of SCA offering different
features and capabilities. Numerical Interpolation methods are very
common in this context, especially by using the Fast Fourier
Transform (FFT). The aim of this paper is to present a method for
SCA that depends on the use of Wavelet Transform (WT) as a
mathematical tool to generate the symbolic expression for large
circuits with minimizing the analysis time by reducing the number of
computations.
Abstract: Measurement and the following evaluation of
performance represent important part of management. The paper
focuses on indicators as the basic elements of performance
measurement system. It emphasizes a necessity of searching
requirements for quality indicators so that they can become part of
the useful system. It introduces standpoints for a systematic dividing
of indicators so that they have as high as possible informative value
of background sources for searching, analysis, designing and using of
indicators. It draws attention to requirements for indicators' quality
and at the same it deals with some dangers decreasing indicator's
informative value. It submits a draft of questions that should be
answered at the construction of indicator. It is obvious that particular
indicators need to be defined exactly to stimulate the desired
behavior in order to attain expected results. In the enclosure a
concrete example of the defined indicator in the concrete conditions
of a small firm is given. The authors of the paper pay attention to the
fact that a quality indicator makes it possible to get to the basic
causes of the problem and include the established facts into the
company information system. At the same time they emphasize that
developing of a quality indicator is a prerequisite for the utilization
of the system of measurement in management.
Abstract: This paper considers the control of the longitudinal
flight dynamics of an F-16 aircraft. The primary design objective
is model-following of the pitch rate q, which is the preferred
system for aircraft approach and landing. Regulation of the aircraft
velocity V (or the Mach-hold autopilot) is also considered, but
as a secondary objective. The problem is challenging because the
system is nonlinear, and also non-affine in the input. A sliding
mode controller is designed for the pitch rate, that exploits the
modal decomposition of the linearized dynamics into its short-period
and phugoid approximations. The inherent robustness of the SMC
design provides a convenient way to design controllers without gain
scheduling, with a steady-state response that is comparable to that
of a conventional polynomial based gain-scheduled approach with
integral control, but with improved transient performance. Integral
action is introduced in the sliding mode design using the recently
developed technique of “conditional integrators", and it is shown that
robust regulation is achieved with asymptotically constant exogenous
signals, without degrading the transient response. Through extensive
simulation on the nonlinear multiple-input multiple-output (MIMO)
longitudinal model of the F-16 aircraft, it is shown that the conditional
integrator design outperforms the one based on the conventional linear
control, without requiring any scheduling.
Abstract: Solar shading designs are important for reduction of building energy consumption and improvement of indoor thermal environment. This paper carried out a number of building simulations for evaluation of the energy performance of different shading devices based on incremental costs. The results show that movable shading devices lower incremental costs by up to 50% compared with fixed ones for the same building energy efficiency for residential buildings, and wing panel shadings are much more suitable in commercial buildings than baring screen ones and overhangs for commercial buildings.
Abstract: The implementation of Super-Ultra Low Emission
Vehicle standards requires more efficient exhaust gas purification. To
increase the efficiency of exhaust gas purification, an the adsorbent
capable of holding hydrocarbons up to 250-300 ОС should be
developed. The possibility to design such adsorbents by modification
of zeolites of mordenite type, ZSM-5 and NaY, using different
metals cations has been studied.
It has been shown that introducing Cr, Cs, Zn, Ni, Co, Li, Mn in
zeolites results in modification of the toluene TPD and toluene
sorption capacity.
5%LiZSM-5 zeolite exhibits the most attractive TPD curve, with
toluene desorption temperature ranging from 250 to 350ОС. The
sorption capacity of 5%Li-ZSM-5 is 0.4 mmol/g. NaY zeolite has the
highest sorption capacity, up to 2 mmol/g, and holds toluene up to
350ОС, but at 120ОС toluene desorption starts, which is not desirable,
since the adsorbent of cold start hydrocarbons should retain them
until 250-300ОС. Therefore 5%LiZSM-5 zeolite was found to be the
most promising to control the cold-start hydrocarbon emissions
among the samples studied.
Abstract: The main purpose of this study is to analyze the
feelings of tourists for the service quality of the bikeway. In addition,
this study also analyzed the causal relationship between service
quality and satisfaction to visitor-s lane loyalty. In this study, the Ya
Tam San bikeway visitor-s subjects, using the designated convenience
sampling carried out the survey, a total of 651 questionnaires were
validly. Valid questionnaires after statistical analysis, the following
findings: 1. Visitor-s lane highest quality of service project: the routes
through the region weather pleasant. Lane "with health and sports," the
highest satisfaction various factors of service quality and satisfaction,
loyal between correlations exist. 4. Guided tours of bikeways, the
quality of the environment, and modeling imagery can effectively
predict visitor satisfaction. 5. Quality of bikeway, public facilities,
guided tours, and modeling imagery can effectively predict visitor
loyalty. According to the above results, the study not only makes
recommendations to the government units and the bicycle industry,
also asked the research direction for future researchers.
Abstract: As computer network technology becomes
increasingly complex, it becomes necessary to place greater
requirements on the validity of developing standards and the
resulting technology. Communication networks are based on large
amounts of protocols. The validity of these protocols have to be
proved either individually or in an integral fashion. One strategy for
achieving this is to apply the growing field of formal methods.
Formal methods research defines systems in high order logic so that
automated reasoning can be applied for verification. In this research
we represent and implement a formerly announced multicast protocol
in Prolog language so that certain properties of the protocol can be
verified. It is shown that by using this approach some minor faults in
the protocol were found and repaired. Describing the protocol as
facts and rules also have other benefits i.e. leads to a process-able
knowledge. This knowledge can be transferred as ontology between
systems in KQML format. Since the Prolog language can increase its
knowledge base every time, this method can also be used to learn an
intelligent network.
Abstract: Nanocrystalline thin film of Na0.1V2O5.nH2O xerogel
obtained by sol gel synthesis was used as gas sensor. Gas sensing
properties of different gases such as hydrogen, petroleum and
humidity were investigated. Applying XRD and TEM the size of the
nanocrystals is found to be 7.5 nm. SEM shows a highly porous
structure with submicron meter-sized voids present throughout the
sample. FTIR measurement shows different chemical groups
identifying the obtained series of gels. The sample was n-type
semiconductor according to the thermoelectric power and electrical
conductivity. It can be seen that the sensor response curves from
130oC to 150oC show a rapid increase in sensitivity for all types of
gas injection, low response values for heating period and the rapid
high response values for cooling period. This result may suggest that
this material is able to act as gas sensor during the heating and
cooling process.
Abstract: This paper describes the development of a 16-ports optical code division multiple access (OCDMA) encoder prototype based on Arrayed Waveguide Grating (AWG) and optical switches. It is potentially to provide a high security for data transmission due to all data will be transmitted in binary code form. The output signals from AWG are coded with a binary code that given to an optical switch before it signal modulate with the carrier and transmitted to the receiver. The 16-ports encoder used 16 double pole double throw (DPDT) toggle switches to control the polarization of voltage source from +5 V to -5 V for 16 optical switches. When +5 V is given, the optical switch will give code '1' and vice versa. The experimental results showed the insertion loss, crosstalk, uniformity, and optical signal-noise-ratio (OSNR) for the developed prototype are
Abstract: A method is presented for using thermo-mechanical fatigue analysis as a tool in the design of automotive heat exchangers. Use of infra-red thermography to measure the real thermal history in the heat exchanger reduces the time necessary for calculating design parameters and improves prediction accuracy. Thermal shocks are the primary cause of heat exchanger damage. Thermo-mechanical simulation is based on the mean behavior of the aluminum tubes used in the heat exchanger. An energetic fatigue criterion is used to detect critical zones.
Abstract: Because support interference corrections are not properly
understood, engineers mostly rely on expensive dummy measurements
or CFD calculations. This paper presents a method based on uncorrected wind tunnel measurements and fast calculation techniques
(it is a hybrid method) to calculate wall interference, support interference and residual interference (when e.g. a support member
closely approaches the wind tunnel walls) for any type of wind tunnel and support configuration. The method provides with a simple formula
for the calculation of the interference gradient. This gradient is
based on the uncorrected measurements and a successive calculation
of the slopes of the interference-free aerodynamic coefficients. For the latter purpose a new vortex-lattice routine is developed that corrects
the slopes for viscous effects. A test case of a measurement on a wing proves the value of this hybrid method as trends and orders of
magnitudes of the interference are correctly determined.
Abstract: The paper presents a modelling methodology for
small scale multi-source renewable energy systems. Using historical
site-specific weather data, the relationships of cost, availability and
energy form are visualised as a function of the sizing of photovoltaic
arrays, wind turbines, and battery capacity. The specific dependency
of each site on its own particular weather patterns show that unique
solutions exist for each site. It is shown that in certain cases the
capital component cost can be halved if the desired theoretical
demand availability is reduced from 100% to 99%.
Abstract: The study on the tree growth for four species groups of commercial timber in Koh Kong province, Cambodia-s tropical rainforest is described. The simulation for these four groups had been successfully developed in the 5-year interval through year-60. Data were obtained from twenty permanent sample plots in the duration of thirteen years. The aim for this study was to develop stand table simulation system of tree growth by the species group. There were five steps involved in the development of the tree growth simulation: aggregate the tree species into meaningful groups by using cluster analysis; allocate the trees in the diameter classes by the species group; observe the diameter movement of the species group. The diameter growth rate, mortality rate and recruitment rate were calculated by using some mathematical formula. Simulation equation had been created by combining those parameters. Result showed the dissimilarity of the diameter growth among species groups.
Abstract: A new analytical model is developed which provides
close-formed solutions for both transient indoor and envelope
temperature changes in buildings. Time-dependent boundary
temperature is presented as Fourier series which can approximate real
weather conditions. The final close-formed solutions are simple,
concise, and comprehensive. The model was compared with
numerical results and good accuracy was obtained. The model can
be used as design and control guidelines in engineering applications
for analysing mechanical heat transfer properties for buildings.
Abstract: Present wireless communication demands compact and intelligent devices with multitasking capabilities at affordable cost. The focus in the presented paper is on a dual band antenna for wireless communication with the capability of operating at two frequency bands with same structure. Two resonance frequencies are observed with the second operation band at 4.2GHz approximately three times the first resonance frequency at 1.5GHz. Structure is simple loop of microstrip line with characteristic impedance 50 ohms. The proposed antenna is designed using defective ground structure (DGS) and shows the nearly one third reductions in size as compared to without DGS. This antenna was simulated on electromagnetic (EM) simulation software and fabricated using microwave integrated circuit technique on RT-Duroid dielectric substrate (εr= 2.22) of thickness (H=15 mils). The designed antenna was tested on automatic network analyzer and shows the good agreement with simulated results. The proposed structure is modeled into an equivalent electrical circuit and simulated on circuit simulator. Subsequently, theoretical analysis was carried out and simulated. The simulated, measured, equivalent circuit response, and theoretical results shows good resemblance. The bands of operation draw many potential applications in today’s wireless communication.
Abstract: In biological and biomedical research motif finding tools are important in locating regulatory elements in DNA sequences. There are many such motif finding tools available, which often yield position weight matrices and significance indicators. These indicators, p-values and E-values, describe the likelihood that a motif alignment is generated by the background process, and the expected number of occurrences of the motif in the data set, respectively. The various tools often estimate these indicators differently, making them not directly comparable. One approach for comparing motifs from different tools, is computing the E-value as the product of the p-value and the number of possible alignments in the data set. In this paper we explore the combinatorics of the motif alignment models OOPS, ZOOPS, and ANR, and propose a generic algorithm for computing the number of possible combinations accurately. We also show that using the wrong alignment model can give E-values that significantly diverge from their true values.
Abstract: This work aims to describe the process of developing
services and applications of seamless communication within a
Telecom Italia long-term research project, which takes as central aim
the design of a wearable communication device. In particular, the
objective was to design a wrist phone integrated into everyday life of
people in full transparency. The methodology used to design the
wristwatch was developed through several subsequent steps also
involving the Personas Layering Framework. The data collected in
this phases have been very useful for designing an improved version
of the first two concepts of wrist phone going to change aspects
related to the four critical points expressed by the users.
Abstract: In this paper, the two-dimension differential transformation method (DTM) is employed to obtain the closed form solutions of the three famous coupled partial differential equation with physical interest namely, the coupled Korteweg-de Vries(KdV) equations, the coupled Burgers equations and coupled nonlinear Schrödinger equation. We begin by showing that how the differential transformation method applies to a linear and non-linear part of any PDEs and apply on these coupled PDEs to illustrate the sufficiency of the method for this kind of nonlinear differential equations. The results obtained are in good agreement with the exact solution. These results show that the technique introduced here is accurate and easy to apply.
Abstract: The aim of this paper is to study in depth some methodological aspects of social interventation, focusing on desirable passage from social maternage method to peer advocacy method. For this purpose, we intend analyze social and organizative components, that affect operator's professional action and that are part of his psychological environment, besides the physical and social one. In fact, operator's interventation should not be limited to a pure supply of techniques, nor to take shape as improvised action, but “full of good purposes".
Abstract: Inconel 718, a nickel based super-alloy is an
extensively used alloy, accounting for about 50% by weight of
materials used in an aerospace engine, mainly in the gas turbine
compartment. This is owing to their outstanding strength and
oxidation resistance at elevated temperatures in excess of 5500 C.
Machining is a requisite operation in the aircraft industries for the
manufacture of the components especially for gas turbines. This
paper is concerned with optimization of the surface roughness when
turning Inconel 718 with cermet inserts. Optimization of turning
operation is very useful to reduce cost and time for machining. The
approach is based on Response Surface Method (RSM). In this work,
second-order quadratic models are developed for surface roughness,
considering the cutting speed, feed rate and depth of cut as the cutting
parameters, using central composite design. The developed models
are used to determine the optimum machining parameters. These
optimized machining parameters are validated experimentally, and it
is observed that the response values are in reasonable agreement with
the predicted values.