Abstract: In this paper, we first introduce the new concept of completely semiprime fuzzy ideals of an ordered semigroup S, which is an extension of completely semiprime ideals of ordered semigroup S, and investigate some its related properties. Especially, we characterize an ordered semigroup that is a semilattice of simple ordered semigroups in terms of completely semiprime fuzzy ideals of ordered semigroups. Furthermore, we introduce the notion of semiprime fuzzy ideals of ordered semigroup S and establish the relations between completely semiprime fuzzy ideals and semiprime fuzzy ideals of S. Finally, we give a characterization of prime fuzzy ideals of an ordered semigroup S and show that a nonconstant fuzzy ideal f of an ordered semigroup S is prime if and only if f is twovalued, and max{f(a), f(b)} = inf f((aSb]), ∀a, b ∈ S.
Abstract: Automated production lines with so called 'hard structures' are widely used in manufacturing. Designers segmented these lines into sections by placing a buffer between the series of machine tools to increase productivity. In real production condition the capacity of a buffer system is limited and real production line can compensate only some part of the productivity losses of an automated line. The productivity of such production lines cannot be readily determined. This paper presents mathematical approach to solving the structure of section-based automated production lines by criterion of maximum productivity.
Abstract: This paper describes the development of a fully
automated measurement software for antenna radiation pattern
measurements in a Compact Antenna Test Range (CATR). The
CATR has a frequency range from 2-40 GHz and the measurement
hardware includes a Network Analyzer for transmitting and
Receiving the microwave signal and a Positioner controller to control
the motion of the Styrofoam column. The measurement process
includes Calibration of CATR with a Standard Gain Horn (SGH)
antenna followed by Gain versus angle measurement of the Antenna
under test (AUT). The software is designed to control a variety of
microwave transmitter / receiver and two axis Positioner controllers
through the standard General Purpose interface bus (GPIB) interface.
Addition of new Network Analyzers is supported through a slight
modification of hardware control module. Time-domain gating is
implemented to remove the unwanted signals and get the isolated
response of AUT. The gated response of the AUT is compared with
the calibration data in the frequency domain to obtain the desired
results. The data acquisition and processing is implemented in
Agilent VEE and Matlab. A variety of experimental measurements
with SGH antennas were performed to validate the accuracy of
software. A comparison of results with existing commercial
softwares is presented and the measured results are found to be
within .2 dBm.
Abstract: An acoustic emission (AE) technique is useful for
detection of partial discharges (PDs) at a joint and a terminal section of
a cross-linked polyethylene (XLPE) cable. For AE technique, it is not
difficult to detect a PD using AE sensors. However, it is difficult to
grasp whether the detected AE signal is owing to a single discharge or
not. Additionally, when an AE technique is applied at a terminal
section of a XLPE cable in salt pollution district, for example, there is
possibility of detection of AE signals owing to creeping discharges on
the surface of electric power apparatus. In this study, we evaluated AE
signals in order to grasp what kind of information we can get from
detected AE signals. The results showed that envelop detection of AE
signal and a period which some AE signals were continuously detected
were good indexes for estimating state-of-discharge.
Abstract: This paper presents a new Hybrid Fuzzy (HF) PID type controller based on Genetic Algorithms (GA-s) for solution of the Automatic generation Control (AGC) problem in a deregulated electricity environment. In order for a fuzzy rule based control system to perform well, the fuzzy sets must be carefully designed. A major problem plaguing the effective use of this method is the difficulty of accurately constructing the membership functions, because it is a computationally expensive combinatorial optimization problem. On the other hand, GAs is a technique that emulates biological evolutionary theories to solve complex optimization problems by using directed random searches to derive a set of optimal solutions. For this reason, the membership functions are tuned automatically using a modified GA-s based on the hill climbing method. The motivation for using the modified GA-s is to reduce fuzzy system effort and take large parametric uncertainties into account. The global optimum value is guaranteed using the proposed method and the speed of the algorithm-s convergence is extremely improved, too. This newly developed control strategy combines the advantage of GA-s and fuzzy system control techniques and leads to a flexible controller with simple stricture that is easy to implement. The proposed GA based HF (GAHF) controller is tested on a threearea deregulated power system under different operating conditions and contract variations. The results of the proposed GAHF controller are compared with those of Multi Stage Fuzzy (MSF) controller, robust mixed H2/H∞ and classical PID controllers through some performance indices to illustrate its robust performance for a wide range of system parameters and load changes.
Abstract: The drastic increase in the usage of SMS technology
has led service providers to seek for a solution that enable users of
mobile devices to access services through SMSs. This has resulted in
the proposal of solutions towards SMS-based service invocation in
service oriented environments. However, the dynamic nature of
service-oriented environments coupled with sudden load peaks
generated by service request, poses performance challenges to
infrastructures for supporting SMS-based service invocation. To
address this problem we adopt load balancing techniques. A load
balancing model with adaptive load balancing and load monitoring
mechanisms as its key constructs is proposed. The load balancing
model then led to realization of Least Loaded Load Balancing
Framework (LLLBF). Evaluation of LLLBF benchmarked with round
robin (RR) scheme on the queuing approach showed LLLBF
outperformed RR in terms of response time and throughput.
However, LLLBF achieved better result in the cost of high
processing power.
Abstract: In this work we present a solution for DAGC (Digital
Automatic Gain Control) in WLAN receivers compatible to IEEE 802.11a/g standard. Those standards define communication in 5/2.4
GHz band using Orthogonal Frequency Division Multiplexing OFDM modulation scheme. WLAN Transceiver that we have used
enables gain control over Low Noise Amplifier (LNA) and a
Variable Gain Amplifier (VGA). The control over those signals is
performed in our digital baseband processor using dedicated hardware block DAGC. DAGC in this process is used to automatically control the VGA and LNA in order to achieve better
signal-to-noise ratio, decrease FER (Frame Error Rate) and hold the
average power of the baseband signal close to the desired set point.
DAGC function in baseband processor is done in few steps: measuring power levels of baseband samples of an RF signal,accumulating the differences between the measured power level and
actual gain setting, adjusting a gain factor of the accumulation, and
applying the adjusted gain factor the baseband values. Based on the measurement results of RSSI signal dependence to input power we have concluded that this digital AGC can be implemented applying
the simple linearization of the RSSI. This solution is very simple but also effective and reduces complexity and power consumption of the
DAGC. This DAGC is implemented and tested both in FPGA and in ASIC as a part of our WLAN baseband processor. Finally, we have integrated this circuit in a compact WLAN PCMCIA board based on MAC and baseband ASIC chips designed from us.
Abstract: This study aims to investigate empirically the valuerelevance
of accounting information to domestic investors in Tehran
stock exchange from 1999 to 2006. During the present research
impacts of two factors, including positive vs. negative earnings and
the firm size are considered as well. The authors used earnings per
share and annual change of earnings per share as the income
statement indices, and book value of equity per share as the balance
sheet index. Return and Price models through regression analysis are
deployed in order to test the research hypothesis. Results depicted
that accounting information is value-relevance to domestic investors
in Tehran Stock Exchange according to both studied models.
However, income statement information has more value-relevance
than the balance sheet information. Furthermore, positive vs. negative
earnings and firm size seems to have significant impact on valuerelevance
of accounting information.
Abstract: In recent years, it has been proposed security
architecture for sensor network.[2][4]. One of these, TinySec by Chris
Kalof, Naveen Sastry, David Wagner had proposed Link layer security
architecture, considering some problems of sensor network. (i.e :
energy, bandwidth, computation capability,etc). The TinySec employs
CBC_mode of encryption and CBC-MAC for authentication based on
SkipJack Block Cipher. Currently, This TinySec is incorporated in the
TinyOS for sensor network security.
This paper introduces TinyHash based on general hash algorithm.
TinyHash is the module in order to replace parts of authentication and
integrity in the TinySec. it implies that apply hash algorithm on
TinySec architecture. For compatibility about TinySec, Components
in TinyHash is constructed as similar structure of TinySec. And
TinyHash implements the HMAC component for authentication and
the Digest component for integrity of messages. Additionally, we
define the some interfaces for service associated with hash algorithm.
Abstract: Flow field around hypersonic vehicles is very
complex and difficult to simulate. The boundary layers are squeezed
between shock layer and body surface. Resolution of boundary layer,
shock wave and turbulent regions where the flow field has high
values is difficult of capture. Detached eddy simulation (DES) is a
modification of a RANS model in which the model switches to a
subgrid scale formulation in regions fine enough for LES
calculations. Regions near solid body boundaries and where the
turbulent length scale is less than the maximum grid dimension are
assigned the RANS mode of solution. As the turbulent length scale
exceeds the grid dimension, the regions are solved using the LES
mode. Therefore the grid resolution is not as demanding as pure LES,
thereby considerably cutting down the cost of the computation. In
this research study hypersonic flow is simulated at Mach 8 and
different angle of attacks to resolve the proper boundary layers and
discontinuities. The flow is also simulated in the long wake regions.
Mesh is little different than RANS simulations and it is made dense
near the boundary layers and in the wake regions to resolve it
properly. Hypersonic blunt cone cylinder body with frustrum at angle
5o and 10 o are simulated and there aerodynamics study is performed
to calculate aerodynamics characteristics of different geometries. The
results and then compared with experimental as well as with some
turbulence model (SA Model). The results achieved with DES
simulation have very good resolution as well as have excellent
agreement with experimental and available data. Unsteady
simulations are performed for DES calculations by using duel time
stepping method or implicit time stepping. The simulations are
performed at Mach number 8 and angle of attack from 0o to 10o for
all these cases. The results and resolutions for DES model found
much better than SA turbulence model.
Abstract: The development of the power electronics has allowed
increasing the precision and reliability of the electrical trainings,
thanks to the adjustable inverters, as the Pulse Wide Modulation
(PWM) five level inverters, which is the object of study in this
article.The authors treat the relation between the law order adopted for
a given system and the oscillations of the electrical and mechanical
parameters of which the tolerance depends on the process with which
they are integrated (paper factory, lifting of the heavy loads,
etc.).Thus the best choice of the regulation indexes allows us to
achieve stability and safety training without investment (management
of existing equipment).
Abstract: As is needless to say; a majority of accidents, which occur, are due to drunk driving. As such, there is no effective mechanism to prevent this. Here we have designed an integrated system for the same purpose. Alcohol content in the driver-s body is detected by means of an infrared breath analyzer placed at the steering wheel. An infrared cell directs infrared energy through the sample and any unabsorbed energy at the other side is detected. The higher the concentration of ethanol, the more infrared absorption occurs (in much the same way that a sunglass lens absorbs visible light, alcohol absorbs infrared light). Thus the alcohol level of the driver is continuously monitored and calibrated on a scale. When it exceeds a particular limit the fuel supply is cutoff. If the device is removed also, the fuel supply will be automatically cut off or an alarm is sounded depending upon the requirement. This does not happen abruptly and special indicators are fixed at the back to avoid inconvenience to other drivers using the highway signals. Frame work for integration of sensors and control module in a scalable multi-agent system is provided .A SMS which contains the current GPS location of the vehicle is sent via a GSM module to the police control room to alert the police. The system is foolproof and the driver cannot tamper with it easily. Thus it provides an effective and cost effective solution for the problem of drunk driving in vehicles.
Abstract: In this paper, a class of impulsive BAM fuzzy cellular neural networks with time delays in the leakage terms is formulated and investigated. By establishing a delay differential inequality and M-matrix theory, some sufficient conditions ensuring the existence, uniqueness and global exponential stability of equilibrium point for impulsive BAM fuzzy cellular neural networks with time delays in the leakage terms are obtained. In particular, a precise estimate of the exponential convergence rate is also provided, which depends on system parameters and impulsive perturbation intention. It is believed that these results are significant and useful for the design and applications of BAM fuzzy cellular neural networks. An example is given to show the effectiveness of the results obtained here.
Abstract: A serious problem on the WWW is finding reliable
information. Not everything found on the Web is true and the
Semantic Web does not change that in any way. The problem will be
even more crucial for the Semantic Web, where agents will be
integrating and using information from multiple sources. Thus, if an
incorrect premise is used due to a single faulty source, then any
conclusions drawn may be in error. Thus, statements published on
the Semantic Web have to be seen as claims rather than as facts, and
there should be a way to decide which among many possibly
inconsistent sources is most reliable. In this work, we propose a trust
model for the Semantic Web. The proposed model is inspired by the
use trust in human society. Trust is a type of social knowledge and
encodes evaluations about which agents can be taken as reliable
sources of information or services. Our proposed model allows
agents to decide which among different sources of information to
trust and thus act rationally on the semantic web.
Abstract: Recently, business environment and customer needs
have become rapidly changing, hence it is very difficult to fulfill
sophisticated customer needs by product or service innovation only. In
practice, to cope with this problem, various manufacturing companies
have developed services to combine with their products. Along with
this, many academic studies on PSS (Product Service System) which is
the integrated system of products and services have been conducted
from the viewpoint of manufacturers. On the other hand, service
providers are also attempting to develop service-supporting products
to increase their service competitiveness and provide differentiated
value. However, there is a lack of research based on the service-centric
point of view. Accordingly, this paper proposes a concept generation
method for service-supporting product development from the
service-centric point of view. This method is designed to be executed
in five consecutive steps: situation analysis, problem definition,
problem resolution, solution evaluation, and concept generation. In
the proposed approach, some tools of TRIZ (Theory of Solving
Inventive Problem) such as ISQ (Innovative Situation Questionnaire)
and 40 inventive principles are employed in order to define problems
of the current services and solve them by generating
service-supporting product concepts. This research contributes to the
development of service-supporting products and service-centric PSSs.
Abstract: Charge Simulation Method (CSM) is one of the very widely used numerical field computation technique in High Voltage (HV) engineering. The high voltage fields of varying non uniformities are encountered in practice. CSM programs being case specific, the simulation accuracies heavily depend on the user (programmers) experience. Here is an effort to understand CSM errors and evolve some guidelines to setup accurate CSM models, relating non uniformities with assignment factors. The results are for the six-point-charge model of sphere-plane gap geometry. Using genetic algorithm (GA) as tool, optimum assignment factors at different non uniformity factors for this model have been evaluated and analyzed. It is shown that the symmetrically placed six-point-charge models can be good enough to set up CSM programs with potential errors less than 0.1% when the field non uniformity factor is greater than 2.64 (field utilization factor less than 52.76%).
Abstract: The concepts of knowledge creation and innovation
have a strong relationship but this relationship has not been examined
systematically. This study examines the utilization of knowledge
creation processes of the Theory of Knowledge Creation in Higher
Education Institutions. These processes consist of socialization,
externalization, combination and internalization. This study suggests
that the utilization of these processes will give impacts on innovation
in academic performance. A cross-sectional study was conducted
using survey questionnaires to collect data of the utilization of
knowledge creation processes and classroom-s innovation. The
samples are Business Management students of a Malaysian Higher
Education Institution. The results of this study could help Higher
Education Institutions to enrich the learning process of students
through knowledge creation and innovation.
Abstract: This research was aimed to develop and determine the
quality of online learning activities kit as well as to examine the
learning achievement of students and their satisfaction towards the kit
through authentic assessment. The tools in this research contained
online learning activities kit on plant in Thai literature in compliance
with the School Botanical Garden of Plant Genetic Conservation
Project under the Royal Initiative of Her Royal Highness Princess
Maha Chakri Sirindhorn, the assessment form, the learning
achievement test, the satisfaction form and the authentic assessment
form. The population consisted of 40 students in the second range of
primary years (Prathomsuksa 4 to 6) at Ban Khao Rak School,
Suratthani Province, Thailand. The research results showed that the
content quality of the developed online learning activities kit as
assessed by the experts was 4.70 on average or at very high level.
The pre-test and post-test comparison was made to examine the
learning achievement and it revealed that the post-test score was
higher than the pre-test score with statistical significance at the .01
level. The satisfaction of the sampling group towards the online
learning activities kit was 4.74 or at the highest level. The authentic
assessment showed an average of 1.69 or at good level. Therefore,
the online learning activities kit on plant in Thai literature in
compliance with the School Botanical Garden of Plant Genetic
Conservation Project under the Royal Initiative of Her Royal
Highness Princess Maha Chakri Sirindhorn could be used in real
classroom situations.
Abstract: The aim of the study was to investigate the possible
use of commercial Computational Fluid Dynamics (CFD) software in
the design process of a domestic gas boiler. Because of the limited
computational resources some simplifications had to be made in
order to contribute to the design in a reasonable timescale.
The porous media model was used in order to simulate the
influence of the pressure drop characteristic of particular elements of
a heat transfer system on the water-flow distribution in the system.
Further, a combination of CFD analyses and spread sheet
calculations was used in order to solve the flow distribution problem.
Abstract: Abovepresented work deals with the new scope of application of information and communication technologies for the improvement of the election process in the biased environment. We are introducing a new concept of construction of the information-communication system for the election participant. It consists of four main components: Software, Physical Infrastructure, Structured Information and the Trained Stuff. The Structured Information is the bases of the whole system and is the collection of all possible events (irregularities among them) at the polling stations, which are structured in special templates, forms and integrated in mobile devices.The software represents a package of analytic modules, which operates with the dynamic database. The application of modern communication technologies facilities the immediate exchange of information and of relevant documents between the polling stations and the Server of the participant. No less important is the training of the staff for the proper functioning of the system. The e-training system with various modules should be applied in this respect. The presented methodology is primarily focused on the election processes in the countries of emerging democracies.It can be regarded as the tool for the monitoring of elections process by the political organization(s) and as one of the instruments to foster the spread of democracy in these countries.