Abstract: The simulation of external aerodynamics is one of the most challenging and important automotive CFD applications. With the rapid developments of digital computers, CFD is used as a practical tool in modern fluid dynamics research. It integrates fluid mechanics disciplines, mathematics and computer science. In this study, two different types of simulations were made, one for the flow around a simplified high speed passenger car with a rear-spoiler and the other for the flow without a rear-spoiler. The standard k-ε model is selected to numerically simulate the external flow field of the simplified Camry model with or without a rear-spoiler. Through an analysis of the simulation results, a new rear spoiler is designed and it shows a mild reduction of the vehicle aerodynamics drag. This leads to less vehicle fuel consumption on the road.
Abstract: Since polymerase chain reaction (PCR) has been
invented, it has emerged as a powerful tool in genetic analysis. The
PCR products are closely linked with thermal cycles. Therefore, to
reduce the reaction time and make temperature distribution uniform in
the reaction chamber, a novel oscillatory thermal cycler is designed.
The sample is placed in a fixed chamber, and three constant isothermal
zones are established and lined in the system. The sample is oscillated
and contacted with three different isothermal zones to complete
thermal cycles. This study presents the design of the geometric
characteristics of the chamber. The commercial software
CFD-ACE+TM is utilized to investigate the influences of various
materials, heating times, chamber volumes, and moving speed of the
chamber on the temperature distributions inside the chamber. The
chamber moves at a specific velocity and the boundary conditions
with time variations are related to the moving speed. Whereas the
chamber moves, the boundary is specified at the conditions of the
convection or the uniform temperature. The user subroutines compiled
by the FORTRAN language are used to make the numerical results
realistically. Results show that the reaction chamber with a rectangular
prism is heated on six faces; the effects of various moving speeds of
the chamber on the temperature distributions are examined. Regarding
to the temperature profiles and the standard deviation of the
temperature at the Y-cut cross section, the non-uniform temperature
inside chamber is found as the moving speed is larger than 0.01 m/s.
By reducing the heating faces to four, the standard deviation of the
temperature of the reaction chamber is under 1.4×10-3K with the range
of velocities between 0.0001 m/s and 1 m/s. The nature convective
boundary conditions are set at all boundaries while the chamber moves
between two heaters, the effects of various moving velocities of the
chamber on the temperature distributions are negligible at the assigned
time duration.
Abstract: Traffic enforcement units (the Police) are partly
responsible for the severity and frequency of the traffic accidents via
the effectiveness of their safety measures. The Police claims that the
reductions in accidents and their severities occur largely by their
timely interventions at the black spots, through traffic management
or temporary changes in the road design (guiding, reducing speeds
and eliminating sight obstructions, etc.). Yet, some other external
factors than the Police measures may intervene into which such
claims require a statistical confirmation. In order to test the net
impact of the Police contribution in the reduction of the number of
crashes, Chi square test was applied for 25 spots (streets and
intersections) and an average evaluation was achieved for general
conclusion in the case study of Izmir city. Separately, the net impact
of economic crisis in the reduction of crashes is assessed by the
trend analysis for the case of the economic crisis with the probable
reduction effects on the trip generation or modal choice. Finally, it
was proven that the Police measures were effective to some degree as
they claimed, though the economic crisis might have only negligible
contribution to the reductions in the same period observed.
Abstract: This paper proposes a new design of spatial FIR
filter to automatically detect water level from a video signal of
various river surroundings. A new approach in this report applies
"addition" of frames and a "horizontal" edge detector to distinguish
water region and land region. Variance of each line of a filtered
video frame is used as a feature value. The water level is recognized
as a boundary line between the land region and the water region.
Edge detection filter essentially demarcates between two distinctly
different regions. However, the conventional filters are not
automatically adaptive to detect water level in various lighting
conditions of river scenery. An optimized filter is purposed so that
the system becomes robust to changes of lighting condition. More
reliability of the proposed system with the optimized filter is
confirmed by accuracy of water level detection.
Abstract: The launching nose plays an important role in the
incremental launching construction. The parameters of the launching
nose essentially affect the internal forces of the girder during the
construction. The appropriate parameters can decrease the internal
forces in the girder and save the material and reduce the cost. The
simplified structural model, which is made with displacement method
according to the characteristic of incremental launching construction
and the variation rule of the internal forces, calculates and analyzes the
effect of the length, the rigidity and weight of launch nose on the
internal forces of girder during the incremental launching
construction. The method, which can calculate the launching nose
parameters for the optimum incremental launching construction, is
achieved. This method is simple, reliable and easy for practical use.
Abstract: Among all mechanical joining processes, welding has
been employed for its advantage in design flexibility, cost saving,
reduced overall weight and enhanced structural performance.
However, for structures made of relatively thin components, welding
can introduce significant buckling distortion which causes loss of
dimensional control, structural integrity and increased fabrication
costs. Different parameters can affect buckling behavior of welded
thin structures such as, heat input, welding sequence, dimension of
structure. In this work, a 3-D thermo elastic-viscoplastic finite
element analysis technique is applied to evaluate the effect of shell
dimensions on buckling behavior and entropy generation of welded
thin shells. Also, in the present work, the approximated longitudinal
transient stresses which produced in each time step, is applied to the
3D-eigenvalue analysis to ratify predicted buckling time and
corresponding eigenmode. Besides, the possibility of buckling
prediction by entropy generation at each time is investigated and it is
found that one can predict time of buckling with drawing entropy
generation versus out of plane deformation. The results of finite
element analysis show that the length, span and thickness of welded
thin shells affect the number of local buckling, mode shape of global
buckling and post-buckling behavior of welded thin shells.
Abstract: Service identification is one of the main activities in
the modeling of a service-oriented solution, and therefore errors
made during identification can flow down through detailed design
and implementation activities that may necessitate multiple
iterations, especially in building composite applications. Different
strategies exist for how to identify candidate services that each of
them has its own benefits and trade offs. The approach presented in
this paper proposes a selective identification of services approach,
based on in depth business process analysis coupled with use cases
and existing assets analysis and goal service modeling. This article
clearly emphasizes the key activities need for the analysis and
service identification to build a optimized service oriented
architecture. In contrast to other approaches this article mentions
some best practices and steps, wherever appropriate, to point out the
vagueness involved in service identification.
Abstract: A new interface circuit for capacitive sensor is
presented. This paper presents the design and simulation of soil
moisture capacitive sensor interface circuit based on phase
differential technique. The circuit has been designed and fabricated
using MIMOS- 0.35"m CMOS technology. Simulation and test
results show linear characteristic from 36 – 52 degree phase
difference, representing 0 – 100% in soil moisture level. Test result
shows the circuit has sensitivity of 0.79mV/0.10 phase difference,
translating into resolution of 10% soil moisture level.
Abstract: Apparel product development is an important stage in the life cycle of a product. Shortening this stage will help to reduce the costs of a garment. The aim of this study is to examine the production parameters in knitwear apparel companies by defining the unit costs, and developing a software to calculate the unit costs of garments and make the cost estimates. In this study, with the help of a questionnaire, different companies- systems of unit cost estimating and cost calculating were tried to be analyzed. Within the scope of the questionnaire, the importance of cost estimating process for apparel companies and the expectations from a new cost estimating program were investigated. According to the results of the questionnaire, it was seen that the majority of companies which participated to the questionnaire use manual cost calculating methods or simple Microsoft Excel spreadsheets to make cost estimates. Furthermore, it was discovered that many companies meet with difficulties in archiving the cost data for future use and as a solution to that problem, it is thought that prior to making a cost estimate, sub units of garment costs which are fabric, accessory and the labor costs should be analyzed and added to the database of the programme beforehand. Another specification of the cost estimating unit prepared in this study is that the programme was designed to consist of two main units, one of which makes the product specification and the other makes the cost calculation. The programme is prepared as a web-based application in order that the supplier, the manufacturer and the customer can have the opportunity to communicate through the same platform.
Abstract: One of the major cause of eye strain and other
problems caused while watching television is the relative illumination between the screen and its surrounding. This can be
overcome by adjusting the brightness of the screen with respect to the surrounding light. A controller based on fuzzy logic is proposed
in this paper. The fuzzy controller takes in the intensity of light
surrounding the screen and the present brightness of the screen as input. The output of the fuzzy controller is the grid voltage corresponding to the required brightness. This voltage is given to CRT and brightness is controller dynamically. For the given test system data, different de-fuzzifier methods have been implemented and the results are compared. In order to validate the effectiveness of
the proposed approach, a fuzzy controller has been designed by obtaining a test data from a real time system. The simulations are
performed in MATLAB and are verified with standard system data. The proposed approach can be implemented for real time
applications.
Abstract: Over the past few years, a number of efforts have
been exerted to build parallel processing systems that utilize the idle
power of LAN-s and PC-s available in many homes and corporations.
The main advantage of these approaches is that they provide cheap
parallel processing environments for those who cannot afford the
expenses of supercomputers and parallel processing hardware.
However, most of the solutions provided are not very flexible in the
use of available resources and very difficult to install and setup.
In this paper, a multi-level web-based parallel processing system
(MWPS) is designed (appendix). MWPS is based on the idea of
volunteer computing, very flexible, easy to setup and easy to use.
MWPS allows three types of subscribers: simple volunteers (single
computers), super volunteers (full networks) and end users. All of
these entities are coordinated transparently through a secure web site.
Volunteer nodes provide the required processing power needed by
the system end users. There is no limit on the number of volunteer
nodes, and accordingly the system can grow indefinitely. Both
volunteer and system users must register and subscribe. Once, they
subscribe, each entity is provided with the appropriate MWPS
components. These components are very easy to install.
Super volunteer nodes are provided with special components that
make it possible to delegate some of the load to their inner nodes.
These inner nodes may also delegate some of the load to some other
lower level inner nodes .... and so on. It is the responsibility of the
parent super nodes to coordinate the delegation process and deliver
the results back to the user.
MWPS uses a simple behavior-based scheduler that takes into
consideration the current load and previous behavior of processing
nodes. Nodes that fulfill their contracts within the expected time get a
high degree of trust. Nodes that fail to satisfy their contract get a
lower degree of trust.
MWPS is based on the .NET framework and provides the minimal
level of security expected in distributed processing environments.
Users and processing nodes are fully authenticated. Communications
and messages between nodes are very secure. The system has been
implemented using C#.
MWPS may be used by any group of people or companies to
establish a parallel processing or grid environment.
Abstract: Although a picture can be automatically a graphic
work, but especially in the field of graphics and images based on the
idea of advertising and graphic design will be prepared and
photographers to realize the design using his own knowledge and
skills to help does. It is evident that knowledge of photography,
photographer and designer of the facilities, fields of reaching a
higher level of quality offers. At the same time do not have a graphic
designer is also skilled photographer, but can execute your idea may
delegate to an expert photographer. Using technology and methods in
all fields of photography, graphic art may be applicable. But most of
its application in Iran, in works such as packaging, posters, Bill
Board, advertising, brochures and catalogs are. In this study, we
review how the images and techniques in the chart should be used in
Iranian graphic photo what impact has left. Using photography
techniques and procedures can be designed and helped advance the
goals graphic. Technique could not determine the idea. But what is
important to think about design and photography and his creativity
can flourish as a tool to be effective graphic designer in mind.
Computer software to help it's very promotes creativity techniques
shall graphic designer but also it is as a tool. Using images in various
fields, especially graphic arts and only because it is not being
documented, but applications are beautiful. As to his photographic
style from today is graphics. Graphic works try to affect impacts on
their audience. Hence the photo as an important factor is attention.
The other hand saw the man with the extent of forgiving and
understanding people's image, instead of using the word to your files,
allows large messages and concepts should be sent in the shortest
time. Posters, advertisements, brochures, catalog and packaging
products very diverse agricultural, industrial and food could not be
self-image. Today, the use of graphic images for a big score and the
photos to richen the role graphic design plays a major.
Abstract: The latest Geographic Information System (GIS)
technology makes it possible to administer the spatial components of
daily “business object," in the corporate database, and apply suitable
geographic analysis efficiently in a desktop-focused application. We
can use wireless internet technology for transfer process in spatial
data from server to client or vice versa. However, the problem in
wireless Internet is system bottlenecks that can make the process of
transferring data not efficient. The reason is large amount of spatial
data. Optimization in the process of transferring and retrieving data,
however, is an essential issue that must be considered. Appropriate
decision to choose between R-tree and Quadtree spatial data indexing
method can optimize the process. With the rapid proliferation of
these databases in the past decade, extensive research has been
conducted on the design of efficient data structures to enable fast
spatial searching. Commercial database vendors like Oracle have also
started implementing these spatial indexing to cater to the large and
diverse GIS. This paper focuses on the decisions to choose R-tree
and quadtree spatial indexing using Oracle spatial database in mobile
GIS application. From our research condition, the result of using
Quadtree and R-tree spatial data indexing method in one single
spatial database can save the time until 42.5%.
Abstract: This paper presents a pulse doubling technique in a 12-pulse ac-dc converter which supplies direct torque controlled motor drives (DTCIMD-s) in order to have better power quality conditions at the point of common coupling. The proposed technique increases the number of rectification pulses without significant changes in the installations and yields in harmonic reduction in both ac and dc sides. The 12-pulse rectified output voltage is accomplished via two paralleled six-pulse ac-dc converters each of them consisting of three-phase diode bridge rectifier. An autotransformer is designed to supply the rectifiers. The design procedure of magnetics is in a way such that makes it suitable for retrofit applications where a six-pulse diode bridge rectifier is being utilized. Independent operation of paralleled diode-bridge rectifiers, i.e. dc-ripple re-injection methodology, requires a Zero Sequence Blocking Transformer (ZSBT). Finally, a tapped interphase reactor is connected at the output of ZSBT to double the pulse numbers of output voltage up to 24 pulses. The aforementioned structure improves power quality criteria at ac mains and makes them consistent with the IEEE-519 standard requirements for varying loads. Furthermore, near unity power factor is obtained for a wide range of DTCIMD operation. A comparison is made between 6- pulse, 12-pulse, and proposed converters from view point of power quality indices. Results show that input current total harmonic distortion (THD) is less than 5% for the proposed topology at various loads.
Abstract: Typical Intelligent Decision Support System is 4-based, its design composes of Data Warehouse, Online Analytical Processing, Data Mining and Decision Supporting based on models, which is called Decision Support System Based on Data Warehouse (DSSBDW). This way takes ETL,OLAP and DM as its implementing means, and integrates traditional model-driving DSS and data-driving DSS into a whole. For this kind of problem, this paper analyzes the DSSBDW architecture and DW model, and discusses the following key issues: ETL designing and Realization; metadata managing technology using XML; SQL implementing, optimizing performance, data mapping in OLAP; lastly, it illustrates the designing principle and method of DW in DSSBDW.
Abstract: The brain MR imaging-based clinical research and analysis system were specifically built and the development for a large-scale data was targeted. We used the general clinical data available for building large-scale data. Registration period for the selection of the lesion ROI and the region growing algorithm was used and the Mesh-warp algorithm for matching was implemented. The accuracy of the matching errors was modified individually. Also, the large ROI research data can accumulate by our developed compression method. In this way, the correctly decision criteria to the research result was suggested. The experimental groups were age, sex, MR type, patient ID and smoking which can easily be queries. The result data was visualized of the overlapped images by a color table. Its data was calculated by the statistical package. The evaluation for the utilization of this system in the chronic ischemic damage in the area has done from patients with the acute cerebral infarction. This is the cause of neurologic disability index location in the center portion of the lateral ventricle facing. The corona radiate was found in the position. Finally, the system reliability was measured both inter-user and intra-user registering correlation.
Abstract: The evolutionary design of electronic circuits, or
evolvable hardware, is a discipline that allows the user to
automatically obtain the desired circuit design. The circuit
configuration is under the control of evolutionary algorithms. Several
researchers have used evolvable hardware to design electrical
circuits. Every time that one particular algorithm is selected to carry
out the evolution, it is necessary that all its parameters, such as
mutation rate, population size, selection mechanisms etc. are tuned in
order to achieve the best results during the evolution process. This
paper investigates the abilities of evolution strategy to evolve digital
logic circuits based on programmable logic array structures when
different mutation rates are used. Several mutation rates (fixed and
variable) are analyzed and compared with each other to outline the
most appropriate choice to be used during the evolution of
combinational logic circuits. The experimental results outlined in this
paper are important as they could be used by every researcher who
might need to use the evolutionary algorithm to design digital logic
circuits.
Abstract: Multiplication algorithms have considerable effect on
processors performance. A new high-speed, low-power
multiplication algorithm has been presented using modified Dadda
tree structure. Three important modifications have been implemented
in inner product generation step, inner product reduction step and
final addition step. Optimized algorithms have to be used into basic
computation components, such as multiplication algorithms. In this
paper, we proposed a new algorithm to reduce power, delay, and
transistor count of a multiplication algorithm implemented using low
power modified counter. This work presents a novel design for
Dadda multiplication algorithms. The proposed multiplication
algorithm includes structured parts, which have important effect on
inner product reduction tree. In this paper, a 1.3V, 64-bit carry hybrid
adder is presented for fast, low voltage applications. The new 64-bit
adder uses a new circuit to implement the proposed carry hybrid
adder. The new adder using 80 nm CMOS technology has been
implemented on 700 MHz clock frequency. The proposed
multiplication algorithm has achieved 14 percent improvement in
transistor count, 13 percent reduction in delay and 12 percent
modification in power consumption in compared with conventional
designs.
Abstract: Vertical Double Gate (DG) Metal Oxide Semiconductor Field Effect Transistor (MOSFET) is believed to suppress various short channel effect problems. The gate to channel coupling in vertical DG-MOSFET are doubled, thus resulting in higher current density. By having two gates, both gates are able to control the channel from both sides and possess better electrostatic control over the channel. In order to ensure that the transistor possess a superb turn-off characteristic, the subs-threshold swing (SS) must be kept at minimum value (60-90mV/dec). By utilizing SILVACO TCAD software, an n-channel vertical DG-MOSFET was successfully designed while keeping the sub-threshold swing (SS) value as minimum as possible. From the observation made, the value of sub-threshold swing (SS) was able to be varied by adjusting the height of the silicon pillar. The minimum value of sub-threshold swing (SS) was found to be 64.7mV/dec with threshold voltage (VTH) of 0.895V. The ideal height of the vertical DG-MOSFET pillar was found to be at 0.265 µm.
Abstract: Virtual engineering technology has undergone rapid progress in recent years and is being adopted increasingly by manufacturing companies of many engineering disciplines. There is an increasing demand from industry for qualified virtual engineers. The qualified virtual engineers should have the ability of applying engineering principles and mechanical design methods within the commercial software package environment. It is a challenge to the engineering education in universities which traditionally tends to lack the integration of knowledge and skills required for solving real world problems. In this paper, a case study shows some recent development of a MSc Mechanical Engineering course at Department of Engineering and Technology in MMU, and in particular, two units Simulation of Mechanical Systems(SMS) and Computer Aided Fatigue Analysis(CAFA) that emphasize virtual engineering education and promote integration of knowledge acquisition, skill training and industrial application.