Abstract: The purpose of the present study is the calculation of Gutenber-Richter parameters (a, b) and analyze the mean annual rate of exceedance of earthquake magnitude (Om ) of southern segment of the Sagaing fault and its associate components. The study area is situated about 200 km radius centered at Yangon. Earthquake data file is using from 1975 to 2006 August 31. The bounded Gutenberg- Richter recurrence law for 0 M is 4.0 and max M is 7.5.
Abstract: Knowledge about the magnetic quantities in a magnetic circuit is always of great interest. On the one hand, this information is needed for the simulation of a transformer. On the other hand, parameter studies are more reliable, if the magnetic quantities are derived from a well established model. One possibility to model the 3-phase transformer is by using a magnetic equivalent circuit (MEC). Though this is a well known system, it is often not an easy task to set up such a model for a large number of lumped elements which additionally includes the nonlinear characteristic of the magnetic material. Here we show the setup of a solver for a MEC and the results of the calculation in comparison to measurements taken. The equations of the MEC are based on a rearranged system of the nodal analysis. Thus it is possible to achieve a minimum number of equations, and a clear and simple structure. Hence, it is uncomplicated in its handling and it supports the iteration process. Additional helpful tasks are implemented within the solver to enhance the performance. The electric circuit is described by an electric equivalent circuit (EEC). Our results for the 3-phase transformer demonstrate the computational efficiency of the solver, and show the benefit of the application of a MEC.
Abstract: A theoretical study is conducted to design and explore
the effect of different parameters such as heat loads, the tube size of
piping system, wick thickness, porosity and hole size on the
performance and capability of a Loop Heat Pipe(LHP). This paper
presents a steady state model that describes the different phenomena
inside a LHP. Loop Heat Pipes(LHPs) are two-phase heat transfer
devices with capillary pumping of a working fluid. By their original
design comparing with heat pipes and special properties of the
capillary structure, they-re capable of transferring heat efficiency for
distances up to several meters at any orientation in the gravity field,
or to several meters in a horizontal position. This theoretical model is
described by different relations to satisfy important limits such as
capillary and nucleate boiling. An algorithm is developed to predict
the size of the LHP satisfying the limitations mentioned above for a
wide range of applied loads. Finally, to assess and evaluate the
algorithm and all the relations considered, we have used to design a
new kind of LHP to recover the heat from the exhaust of an actual
Gas Turbine. By finding the results, it showed that we can use the
LHP as a very high efficient device to recover the heat even in high
amount of loads(exhaust of a gas turbine). The sizes of all parts of the
LHP were obtained using the developed algorithm.
Abstract: Effective employee selection is a critical component
of a successful organization. Many important criteria for personnel
selection such as decision-making ability, adaptability, ambition, and
self-organization are naturally vague and imprecise to evaluate. The
rough sets theory (RST) as a new mathematical approach to
vagueness and uncertainty is a very well suited tool to deal with
qualitative data and various decision problems. This paper provides
conceptual, descriptive, and simulation results, concentrating chiefly
on human resources and personnel selection factors. The current
research derives certain decision rules which are able to facilitate
personnel selection and identifies several significant features based
on an empirical study conducted in an IT company in Iran.
Abstract: Switched-mode converters play now a significant role in
modern society. Their operation are often crucial in various electrical
applications affecting the every day life. Therefore, the quality of
the converters needs to be reliably verified. Recent studies have
shown that the converters can be fully characterized by a set of
frequency responses which can be efficiently used to validate the
proper operation of the converters. Consequently, several methods
have been proposed to measure the frequency responses fast and
accurately. Most often correlation-based techniques have been applied.
The presented measurement methods are highly sensitive to
external errors and system nonlinearities. This fact has been often
forgotten and the necessary uncertainty analysis of the measured
responses has been neglected. This paper presents a simple approach
to analyze the noise and nonlinearities in the frequency-response
measurements of switched-mode converters. Coherence analysis is
applied to form a confidence interval characterizing the noise and
nonlinearities involved in the measurements. The presented method is
verified by practical measurements from a high-frequency switchedmode
converter.
Abstract: Mostly the systems are dealing with time varying
signals. The Power efficiency can be achieved by adapting the system
activity according to the input signal variations. In this context
an adaptive rate filtering technique, based on the level crossing sampling
is devised. It adapts the sampling frequency and the filter order
by following the input signal local variations. Thus, it correlates the
processing activity with the signal variations. Interpolation is required
in the proposed technique. A drastic reduction in the interpolation
error is achieved by employing the symmetry during the interpolation
process. Processing error of the proposed technique is
calculated. The computational complexity of the proposed filtering
technique is deduced and compared to the classical one. Results
promise a significant gain of the computational efficiency and hence
of the power consumption.
Abstract: Producing companies aspire to high delivery
availability despite appearing disruptions. To ensure high delivery
availability safety stocksare required. Howeversafety stock leads to
additional capital commitment and compensates disruptions instead
of solving the reasons.The intention is to increase the stability in
production by configuring the production planning and control
systematically. Thus the safety stock can be reduced. The largest
proportion of inventory in producing companies is caused by batch
inventory, schedule deviations and variability of demand rates.These
reasons for high inventory levels can be reduced by configuring the
production planning and control specifically. Hence the inventory
level can be reduced. This is enabled by synchronizing the lot size
straightening the demand as well as optimizing the releasing order,
sequencing and capacity control.
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 first-countable spaces, soft second-countable spaces and soft separable spaces, and some basic properties of these concepts are explored.
Abstract: The values of managers and employees in organizations are phenomena that have captured the interest of researchers at large. Despite this attention, there continues to be a lack of agreement on what values are and how they influence individuals, or how they are constituted in individuals- mind. In this article content-based approach is presented as alternative reference frame for exploring values. In content-based approach human thinking in different contexts is set at the focal point. Differences in valuations can be explained through the information contents of mental representations. In addition to the information contents, attention is devoted to those cognitive processes through which mental representations of values are constructed. Such informational contents are in decisive role for understanding human behavior. By applying content-based analysis to an examination of values as mental representations, it is possible to reach a deeper to the motivational foundation of behaviors, such as decision making in organizational procedures, through understanding the structure and meanings of specific values at play.
Abstract: Granular computing deals with representation of information in the form of some aggregates and related methods for transformation and analysis for problem solving. A granulation scheme based on clustering and Rough Set Theory is presented with focus on structured conceptualization of information has been presented in this paper. Experiments for the proposed method on four labeled data exhibit good result with reference to classification problem. The proposed granulation technique is semi-supervised imbibing global as well as local information granulation. To represent the results of the attribute oriented granulation a tree structure is proposed in this paper.
Abstract: Masonry cavity walls are loaded by wind pressure and vertical load from upper floors. These loads results in bending moments and compression forces in the ties connecting the outer and the inner wall in a cavity wall. Large cavity walls are furthermore loaded by differential movements from the temperature gradient between the outer and the inner wall, which results in critical increase of the bending moments in the ties. Since the ties are loaded by combined compression and moment forces, the loadbearing capacity is derived from instability equilibrium equations. Most of them are iterative, since exact instability solutions are complex to derive, not to mention the extra complexity introducing dimensional instability from the temperature gradients. Using an inverse variable substitution and comparing an exact theory with an analytical instability solution a method to design tie-connectors in cavity walls was developed. The method takes into account constraint conditions limiting the free length of the wall tie, and the instability in case of pure compression which gives an optimal load bearing capacity. The model is illustrated with examples from praxis.
Abstract: Polystyrene particles of different sizes are optically
trapped with a gaussian beam from a He-Cd laser operating at 442
nm. The particles are observed to exhibit luminescence after a certain
trapping time followed by an escape from the optical trap. The
observed luminescence is explained in terms of the photodegradation
of the polystyrene backbone. It is speculated that these chemical
modifications also play a role for the escape of the particles from the
trap. Variations of the particle size and the laser power show that
these parameters have a great influence on the observed phenomena.
Abstract: The main focus of this paper is on the human induced
forces. Almost all existing force models for this type of load (defined
either in the time or frequency domain) are developed from the
assumption of perfect periodicity of the force and are based on force
measurements conducted on rigid (i.e. high frequency) surfaces. To
verify the different authors conclusions the vertical pressure
measurements invoked during the walking was performed, using
pressure gauges in various configurations. The obtained forces are
analyzed using Fourier transformation. This load is often decisive in
the design of footbridges. Design criteria and load models proposed
by widely used standards and other researchers were introduced and a
comparison was made.
Abstract: In this paper, mathematical models for permutation flow shop scheduling and job shop scheduling problems are proposed. The first problem is based on a mixed integer programming model. As the problem is NP-complete, this model can only be used for smaller instances where an optimal solution can be computed. For large instances, another model is proposed which is suitable for solving the problem by stochastic heuristic methods. For the job shop scheduling problem, a mathematical model and its main representation schemes are presented.
Abstract: Numerous experimental tests for post-installed anchor systems drilled in hardened concrete were conducted in order to estimate pull-out and shear strength accounting for uncertainties such as torque ratios, embedment depths and different diameters in demands. In this study, the strength of the systems was significantly changed by the effect of those three uncertainties during pull-out experimental tests, whereas the shear strength of the systems was not affected by torque ratios. It was also shown that concrete cone failure or damage mechanism was generally investigated during and after pull-out tests and in shear strength tests, mostly the anchor systems were failed prior to failure of primary structural system. Furthermore, 3D finite element model for the anchor systems was created by ABAQUS for the numerical analysis. The verification of finite element model was identical till the failure points to the load-displacement relationship specified by the experimental tests.
Abstract: In this paper a simple watermarking method for
color images is proposed. The proposed method is based on
watermark embedding for the histograms of the HSV planes
using visual cryptography watermarking. The method has
been proved to be robust for various image processing
operations such as filtering, compression, additive noise, and
various geometrical attacks such as rotation, scaling, cropping,
flipping, and shearing.
Abstract: Optical Coherence Tomography (OCT) combined
with the Confocal Microscopy, as a noninvasive method, permits the
determinations of materials defects in the ceramic layers depth. For
this study 256 anterior and posterior metal and integral ceramic fixed
partial dentures were used, made with Empress (Ivoclar), Wollceram
and CAD/CAM (Wieland) technology. For each investigate area 350
slices were obtain and a 3D reconstruction was perform from each
stuck. The Optical Coherent Tomography, as a noninvasive method,
can be used as a control technique in integral ceramic technology,
before placing those fixed partial dentures in the oral cavity. The
purpose of this study is to evaluate the capability of En face Optical
Coherence Tomography (OCT) combined with a fluorescent method
in detection and analysis of possible material defects in metalceramic
and integral ceramic fixed partial dentures. As a conclusion,
it is important to have a non invasive method to investigate fixed
partial prostheses before their insertion in the oral cavity in order to
satisfy the high stress requirements and the esthetic function.
Abstract: Corrugated wire mesh laminates (CWML) are a class
of engineered open cell structures that have potential for applications
in many areas including aerospace and biomedical engineering. Two
different methods of fabricating corrugated wire mesh laminates from
stainless steel, one using a high temperature Lithobraze alloy and the
other using a low temperature Eutectic solder for joining the
corrugated wire meshes are described herein. Their implementation is
demonstrated by manufacturing CWML samples of 304 and 316
stainless steel (SST). It is seen that due to the facility of employing
wire meshes of different densities and wire diameters, it is possible to
create CWML laminates with a wide range of effective densities. The
fabricated laminates are tested under uniaxial compression. The
variation of the compressive yield strength with relative density of the
CWML is compared to the theory developed by Gibson and Ashby for
open cell structures [22]. It is shown that the compressive strength of
the corrugated wire mesh laminates can be described using the same
equations by using an appropriate value for the linear coefficient in the
Gibson-Ashby model.
Abstract: The present study deals with the modeling and simulation of flow through an annular reactor at different hydrodynamic conditions using computational fluid dynamics (CFD) to investigate the flow behavior. CFD modeling was utilized to predict velocity distribution and average velocity in the annular geometry. The results of CFD simulations were compared with the mathematically derived equations and already developed correlations for validation purposes. CFD modeling was found suitable for predicting the flow characteristics in annular geometry under laminar flow conditions. It was observed that CFD also provides local values of the parameters of interest in addition to the average values for the simulated geometry.
Abstract: This paper generalizes Yeh Lam-s shock model for
renewal shock arrivals and random threshold. Several interesting
statistical measures are explicitly obtained. A few special cases and
an optimal replacement problem are also discussed.