Abstract: The aim of this study is to analyze influence of
differences of heat insulation methods on indoor thermal environment and comfort of apartment buildings.
This study analyzes indoor thermal environment and comfort on units of apartment buildings using calculation software "THERB" and
compares three different kinds of heat insulation methods. Those are
outside insulation on outside walls, inside insulation on outside walls and interior insulation. In terms of indoor thermal environment, outside insulation is the best to stabilize room temperature. In winter, room temperature on
outside insulation after heating is higher than other and it is kept 3-5 degrees higher through all night. But the surface temperature with
outside insulation did not dramatically increase when heating was used, which was 3 to 5oC lower than the temperature with other
insulation. The PMV of interior insulation fall nearly range of comfort when the heating and cooling was use.
Abstract: Mechanical and water transport properties of high
performance concrete (HPC) containing natural zeolite as partial
replacement of Portland cement are studied. Experimental results
show that in the investigated mixes the use of natural zeolite leads to
an increase of porosity, decrease of compressive strength and
increase of moisture diffusivity and water vapor diffusion coefficient,
as compared with the reference HPC. However, for the replacement
level up to 20% of the mass of Portland cement the concretes still
maintain their high performance character and exhibit acceptable
water transport properties. Therefore, natural zeolite can be
considered an environmental friendly binder with a potential to
replace a part of Portland cement in concrete in building industry.
Abstract: The 'wind-rain' house has a courtyard with glazed
roof, which allows more direct sunlight to come into indoor spaces
during the winter. The glazed roof can be partially opened or closed
and automatically controlled to provide natural ventilation in order to
adjust for indoor thermal conditions and the roof area can be shaded
by reflective insulation materials during the summer. Two field
studies for evaluating indoor thermal conditions of the two 'windrain'
houses have been carried out by author in 2009 and 2010.
Indoor and outdoor air temperature and relative humidity adjacent to
floor and ceiling of the two sample houses were continuously tested
at 15-minute intervals, 24 hours a day during the winter months.
Based on field study data, this study investigates relationships
between building design and indoor thermal condition of the 'windrain'
house to improve the future house design for building thermal
comfort and energy efficiency
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: A large number of semantic web service composition
approaches are developed by the research community and one is
more efficient than the other one depending on the particular
situation of use. So a close look at the requirements of ones particular
situation is necessary to find a suitable approach to use. In this paper,
we present a Technique Recommendation System (TRS) which using
a classification of state-of-art semantic web service composition
approaches, can provide the user of the system with the
recommendations regarding the use of service composition approach
based on some parameters regarding situation of use. TRS has
modular architecture and uses the production-rules for knowledge
representation.
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: A new method of adaptation in a partially integrated learning environment that includes electronic textbook (ET) and integrated tutoring system (ITS) is described. The algorithm of adaptation is described in detail. It includes: establishment of Interconnections of operations and concepts; estimate of the concept mastering level (for all concepts); estimate of student-s non-mastering level on the current learning step of information on each page of ET; creation of a rank-order list of links to the e-manual pages containing information that require repeated work.
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: 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: 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: 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: 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: Nylon 6-clay hybrid/neat nylon 6, sheath/core
bicomponent nanocomposite fibers containing 4 wt% of clay in
sheath section were melt spun at different take-up speeds. Their
orientation and crystalline structure were compared to those of neat
nylon 6 fibers. Birefringence measurements showed that the
orientation development in sheath and core parts of bicomponent
fibers was different. Crystallinity results showed that clay did not act
as a nucleating agent for bicomponent fibers. The neat nylon 6 fiber
had a smooth surface while striped pattern was appeared on the
surface of bicomponent fiber containing clay due to thermal
shrinkage of the core part.
Abstract: In Lebanon, public construction projects are awarded
to the contractor submitting the lowest bid price based on a
competitive bidding process. The contractor has to make a strategic
decision in choosing the appropriate bid price that will offer a
satisfactory profit with a greater probability to win. A simulation
model for bid price decision making based on the lowest bid price
evaluation is developed. The model, built using Crystal Ball decisionengineering
software, considers two main factors affecting the
bidding process: the number of qualified bidders and the size of the
project. The validity of the model is tested on twelve separate
projects. The study also shows how to use the model to conduct risk
analysis and help any specific contractor to decide on his bid price
with associated certainty level in a scientific method.