Abstract: A stack with a small critical temperature gradient is
desirable for a standing wave thermoacoustic engine to obtain a low
onset temperature difference (the minimum temperature difference to
start engine-s self-oscillation). The viscous and heat relaxation loss in
the stack determines the critical temperature gradient. In this work, a
dimensionless critical temperature gradient factor is obtained based
on the linear thermoacoustic theory. It is indicated that the
impedance determines the proportion between the viscous loss, heat
relaxation losses and the power production from the heat energy. It
reveals the effects of the channel dimensions, geometrical
configuration and the local acoustic impedance on the critical
temperature gradient in stacks. The numerical analysis shows that
there exists a possible optimum combination of these parameters
which leads to the lowest critical temperature gradient. Furthermore,
several different geometries have been tested and compared
numerically.
Abstract: The aim of the article is to describe modern
contemporary systems of employees' remuneration used in
organizations, to give a general overview of these questions based on
the questionnaire survey made by the authors, as well as to assess
possible effects of economic crisis in this area. It is necessary to be
aware of the fact that firm's success in the contemporary business
environment depends not only on the technical equipment, financial
resources, availability of raw materials and information and effective
management, but one of the crucial factors of firm's success is its
human potential. The article emphasizes that the well working
remuneration system has a very important position in the
organization in the broadest sense. The paper also aims to the current
situation in the area of employees' remuneration in one of Czech
Republic regions, in the Moravian-Silesian Region.
Abstract: This paper proposes a direct power control for
doubly-fed induction machine for variable speed wind power
generation. It provides decoupled regulation of the primary side
active and reactive power and it is suitable for both electric energy
generation and drive applications. In order to control the power
flowing between the stator of the DFIG and the network, a decoupled
control of active and reactive power is synthesized using PI
controllers.The obtained simulation results show the feasibility
and the effectiveness of the suggested method
Abstract: An integrated vehicle dynamics control system is developed in this paper by a combination of active front steering (AFS) and direct yaw-moment control (DYC) based on fuzzy logic control. The control system has a hierarchical structure consisting of two layers. A fuzzy logic controller is used in the upper layer (yaw rate controller) to keep the yaw rate in its desired value. The yaw rate error and its rate of change are applied to the upper controlling layer as inputs, where the direct yaw moment control signal and the steering angle correction of the front wheels are the outputs. In the lower layer (fuzzy integrator), a fuzzy logic controller is designed based on the working region of the lateral tire forces. Depending on the directions of the lateral forces at the front wheels, a switching function is activated to adjust the scaling factor of the fuzzy logic controller. Using a nonlinear seven degrees of freedom vehicle model, the simulation results illustrate considerable improvements which are achieved in vehicle handling through the integrated AFS/DYC control system in comparison with the individual AFS or DYC controllers.
Abstract: Normally business changes are made in order to
change a level of activity in some way, whether it is sales, cash flow,
productivity, or product portfolio. When attempts are made to make
such changes, too often the business reverts to the old levels of
activity as soon as management attention is diverted. Risk
management is a field of growing interest to project managers as well
as in general business and organizational management. There are
several approaches used to manage risk in projects and this paper is a
brief outline of some that you might encounter, with an indication of
their strengths and weaknesses.
Abstract: In this paper, we investigate the problem of the existence, uniqueness and global asymptotic stability of the equilibrium point for a class of neural networks, the neutral system has mixed time delays and parameter uncertainties. Under the assumption that the activation functions are globally Lipschitz continuous, we drive a new criterion for the robust stability of a class of neural networks with time delays by utilizing the Lyapunov stability theorems and the Homomorphic mapping theorem. Numerical examples are given to illustrate the effectiveness and the advantage of the proposed main results.
Abstract: Soft topological spaces are considered as mathematical tools for dealing with uncertainties, and a fuzzy topological space
is a special case of the soft topological space. The purpose of this paper is to study soft topological spaces. We introduce some new concepts in soft topological spaces such as soft closed mapping, soft open mappings, soft connected spaces and soft paracompact spaces. We also redefine the concept of soft points such that it is reasonable in soft topological spaces. Moreover, some basic properties of these concepts are explored.
Abstract: This paper describes analysis of low velocity transverse impact on fully backed sandwich beams with composite faces from Eglass/epoxy and cores from Polyurethane or PVC. Indentation on sandwich beams has been analyzed with the existing theories and modeled with the FE code ABAQUS, also loadings have been done experimentally to verify theoretical results. Impact on fully backed has been modeled in two cases of impactor energy with SDOF model (single-degree-of-freedom) and indentation stiffness: lower energy for elastic indentation of sandwich beams and higher energy for plastic area in indentation. Impacts have been modeled by ABAQUS. Impact results can describe response of beam in terms of core and faces thicknesses, core material, indentor energy and energy absorbed. The foam core is modeled using the crushable foam material model and response of the foam core is experimentally characterized in uniaxial compression with higher velocity loading to define quasi impact behaviour.
Abstract: This study is a descriptive-normative research. It
attempted to investigate the restaurants’ firm performance in terms of
the customers and restaurant personnel’s degree of satisfaction. A
total of 12 restaurants in Bangkok, Thailand that offer Thai cuisine
were included in this study. It involved 24 stockholders/managers,
120 subordinates and 360 customers. General Managers and
restaurants’ stockholders, 10 staffs, and 30 costumers for each
restaurant were chosen for random sampling. This study found that
respondents are slightly satisfied with their work environment but are
generally satisfied with the accessibility to transportation, to malls,
convenience, safety, recreation, noise-free, and attraction; customers
find the Quality of Food in most Thai Cuisines like services, prices of
food, sales promotion, and capital and length of service satisfactory.
Therefore, both stockholder-related and personnel-related factors
which are influenced by restaurant, personnel, and customer-related
factors are partially accepted whereas; customer-related factors which
are influenced by restaurant, personnel and customer-related factors
are rejected.
Abstract: In large datasets, identifying exceptional or rare cases
with respect to a group of similar cases is considered very significant
problem. The traditional problem (Outlier Mining) is to find
exception or rare cases in a dataset irrespective of the class label of
these cases, they are considered rare events with respect to the whole
dataset. In this research, we pose the problem that is Class Outliers
Mining and a method to find out those outliers. The general
definition of this problem is “given a set of observations with class
labels, find those that arouse suspicions, taking into account the
class labels". We introduce a novel definition of Outlier that is Class
Outlier, and propose the Class Outlier Factor (COF) which measures
the degree of being a Class Outlier for a data object. Our work
includes a proposal of a new algorithm towards mining of the Class
Outliers, presenting experimental results applied on various domains
of real world datasets and finally a comparison study with other
related methods is performed.
Abstract: Fuller’s earth is a fine-grained, naturally occurring substance that has a substantial ability to adsorb impurities. In the present study Fuller’s earth has been characterized and used for the removal of Pb(II) from aqueous solution. The effect of various physicochemical parameters such as pH, adsorbent dosage and shaking time on adsorption were studied. The result of the equilibrium studies showed that the solution pH was the key factor affecting the adsorption. The optimum pH for adsorption was 5. Kinetics data for the adsorption of Pb(II) was best described by pseudo-second order model. The effective diffusion co-efficient for Pb(II) adsorption was of the order of 10-8 m2/s. The adsorption data for metal adsorption can be well described by Langmuir adsorption isotherm. The maximum uptake of metal was 103.3 mg/g of adsorbent. Mass transfer analysis was also carried out for the adsorption process. The values of mass transfer coefficients obtained from the study indicate that the velocity of the adsorbate transport from bulk to the solid phase was quite fast. The mean sorption energy calculated from Dubinin-Radushkevich isotherm indicated that the metal adsorption process was chemical in nature.
Abstract: In the present study, we aimed to design the
intrauterine and extrauterine exposure to 1800 MHz GSM-like RF
radiation and investigate its possible bio-effects on infant female
rabbits. Totally thirty-six New Zealand White female rabbits, onemonth
old, were randomly divided into four groups which are
composed of 9 rabbits; i. Group I [Intrauterine (IU) exposure(-);
Extrauterine (EU) exposure (-)], Group II [IU exposure (-); EU
exposure (+)], Group III [IU exposure(+);EU exposure(-)], Group IV
[IU exposure (+);EU exposure(+)]. The master regulatory enzymes
activities of pentose phosphate pathway (glucose-6-phosphate
dehydrogenase, G-6PD; 6-phosphogluconate dehydrogenase, 6-
PGDH) and glutathione-dependent metabolism (glutathione
peroxidase, GSH-Px; glutathione reductase, GR; glutathione Stransferase,
GST, thioredoxin reductase, TRx) were analyzed in liver
tissues of young female rabbits. Decreased G-6PD, 6-PGD, GSH-Px,
GR activities were found in Group III compared to Group I (p
Abstract: Our results showed that for the growth of qualitative
seedling and vegetative raw material of ðó. marschallianus Willd. and
T. serphyllum L. it is more profitable to use the in vitro and
hydroponics combined method. In in vitro culture it is possible to do
micro-propagation whole year with 98-99% rhizogenesis. 30000
micro-plants were obtained from one explant during 9 months.
Hydroponic conditions provide the necessary microclimate for
microplants where the survival rate without acclimatization was
93.3%. The essential oil content in hydroponic dry herb of both
species in vegetative and blossom phase was 1.3% whereas in wild
plants it was 1.2%, the content of extractive substances and vitamin
C also exceeded wild plants. Our biochemical and radiochemical
investigations indicated that the medicinal raw materials obtained
from hydroponic and wild plants of Thymus species correspond to
the demands of SPh XI, and the content of artificial radionuclides
does not exceed the MACL.
Abstract: This paper discusses aspects of re-design of loadshedding
schemes with respect to actual developments in the Kosovo
power system. Load-shedding is a type of emergency control that is
designed to ensure system stability by reducing power system load to
match the power generation supply. This paper presents a new
adaptive load-shedding scheme that provides emergency protection
against excess frequency decline, in cases when the Kosovo power
system might be disconnected from the regional transmission
network. The proposed load-shedding scheme uses the local
frequency rate information to adapt the load-shedding pattern to suit
the size and location of the occurring disturbance. The proposed
scheme is tested in a software simulation on a large scale PSS/E
model which represents nine power system areas of Southeast Europe
including the Kosovo power system.
Abstract: The research is to minimize environmental damage
pertinent to maritime activities about the operation of lighter boat
anchorage and its tugboat. The guidance on upgrading current
harbor service and infrastructure has been provided to Kho Sichang
Municpality. This will involve a study of the maritime logistics of
the water area under jurisdiction of the Sichang island Municipality
and possible recommendations may involve charging taxes,
regulations and fees. With implementing these recommendations will
help in protection of the marine environment and in increasing
operator functionality. Additionally, our recommendation is to
generate a consistent revenue stream to the municipality. The action
items contained in this research are feasible and effective, the success
of these initiatives are heavily dependent upon successful promotion
and enforcement. Promoting new rules and regulations effectively
and peacefully can be done through theories and techniques used in
the psychology of persuasion. In order to assure compliance with the
regulations, the municipality must maintain stringent patrols and
fines for violators. In order to become success, the Municipality
must preserve a consistent, transparent and significant enforcement
system. Considering potential opportunities outside of the current
state of the municipality, the authors recommend that Koh Sichang be
given additional jurisdiction to capture value from the master vessels,
as well as to confront the more significant environmental challenges
these vessels pose. Finally, the authors recommend that the Port of
Koh Sichang Island obtain a free port status in order to increase
economic viability and overall sustainability.
Abstract: Color image segmentation plays an important role in
computer vision and image processing areas. In this paper, the
features of Volterra filter are utilized for color image segmentation.
The discrete Volterra filter exhibits both linear and nonlinear
characteristics. The linear part smoothes the image features in
uniform gray zones and is used for getting a gross representation of
objects of interest. The nonlinear term compensates for the blurring
due to the linear term and preserves the edges which are mainly used
to distinguish the various objects. The truncated quadratic Volterra
filters are mainly used for edge preserving along with Gaussian noise
cancellation. In our approach, the segmentation is based on K-means
clustering algorithm in HSI space. Both the hue and the intensity
components are fully utilized. For hue clustering, the special cyclic
property of the hue component is taken into consideration. The
experimental results show that the proposed technique segments the
color image while preserving significant features and removing noise
effects.
Abstract: This paper analysis the integrated use of safety monitoring with the domestic and international latest research on rail safety protection system, and focus on the implementation of an organic whole system, with the monitoring and early warning, risk assessment, predictive control and emergency rescue system. The system framework, contents and system structure of Security system is proposed completely. It-s pointed out that the Security system is a negative feedback system composed of by safety monitoring and warning system, risk assessment and emergency rescue system. Safety monitoring and warning system focus on the monitoring target monitoring, early warning, tracking, integration of decision-making, for objective and subjective risks factors. Risk assessment system analysis the occurrence of a major Security risk mechanism, determines the standard of the future short, medium and long term safety conditions, and give prop for development of safety indicators, accident analysis and safety standards. Emergency rescue system is with the goal of rapid and effective rescue work for accident, to minimize casualties and property losses.
Abstract: In this study, a double-sided linear switched reluctance
motor (LSRM) drive was investigated as an alternative actuator for
vertical linear transportation applications such as a linear elevator
door, hospital and subway doors which move linearly and where
accurate position control and rapid response is requested. A prototype
sliding elevator door that is focused on a home elevator with LSRMs
is designed. The motor has 6/4 poles, 3 phases, 8A, 24V, 250 W and
250 N pull forces. Air gap between rotor and translator poles of the
designed motor and phase coil-s ideal inductance profile are obtained
in compliance with the geometric dimensions. Operation and
switching sections as motor and generator has been determined from
the inductance profile.
Abstract: Semiconductor nanomaterials like TiO2 nanoparticles
(TiO2-NPs) approximately less than 100 nm in diameter have become
a new generation of advanced materials due to their novel and
interesting optical, dielectric, and photo-catalytic properties. With the
increasing use of NPs in commerce, to date few studies have
investigated the toxicological and environmental effects of NPs.
Motivated by the importance of TiO2-NPs that may contribute to the
cancer research field especially from the treatment prospective
together with the fractal analysis technique, we have investigated the
effect of TiO2-NPs on colony morphology in the dark condition
using fractal dimension as a key morphological characterization
parameter. The aim of this work is mainly to investigate the cytotoxic
effects of TiO2-NPs in the dark on the growth of human cervical
carcinoma (HeLa) cell colonies from morphological aspect. The in
vitro studies were carried out together with the image processing
technique and fractal analysis. It was found that, these colonies were
abnormal in shape and size. Moreover, the size of the control
colonies appeared to be larger than those of the treated group. The
mean Df +/- SEM of the colonies in untreated cultures was
1.085±0.019, N= 25, while that of the cultures treated with TiO2-NPs
was 1.287±0.045. It was found that the circularity of the control
group (0.401±0.071) is higher than that of the treated group
(0.103±0.042). The same tendency was found in the diameter
parameters which are 1161.30±219.56 μm and 852.28±206.50 μm
for the control and treated group respectively. Possible explanation of
the results was discussed, though more works need to be done in
terms of the for mechanism aspects. Finally, our results indicate that
fractal dimension can serve as a useful feature, by itself or in
conjunction with other shape features, in the classification of cancer
colonies.
Abstract: Stage bus operated in the mixed traffic might always meet many problems about low quality and reliability of services. The low quality and reliability of bus service can make the system not attractive and directly reduce the interest of using bus service. This paper presents the result of field investigation and analysis of on-time performance and service regularity of stage bus in mixed traffic. Data for analysis was collected from the field by on-board observation along the Ipoh-Lumut corridor in Perak, Malaysia. From analysis and discussion, it can be concluded that on-time performance and service regularity varies depend on station, typical day, time period, operation characteristics of bus and characteristics of traffic. The on-time performance and service regularity of stage bus in mixed traffic can be derived by using data collected by onboard survey. It is clear that on-time performance and service regularity of the existing stage bus system was low.