Abstract: The picture of a perfect road construction site is the one that utilizes conventional vertical road signs and a flagman to optimize the traffic flow with minimum hazel to the public. Former research has been carried out by Department of Occupational Safety and Health (DOSH) and Ministry of Works to further enhance smoothness in traffic operations and particularly in safety issues within work zones. This paper highlights on hazardous zones in a certain road construction or road maintenance site. Most cases show that the flagman falls into high risk of fatal accidents within work zone. Various measures have been taken by both the authorities and contractors to overcome such miseries, yet it-s impossible to eliminate the usage of a flagman since it is considered the best practice. With the implementation of new technologies in automating the traffic flow in road construction site, it is possible to eliminate the usage of a flagman. The intelligent traffic light system is designed to solve problems which contribute hazardous at road construction site and to be inline with the road safety regulation which is taken into granted.
Abstract: The Mobile IP Standard has been developed to support mobility over the Internet. This standard contains several drawbacks as in the cases where packets are routed via sub-optimal paths and significant amount of signaling messages is generated due to the home registration procedure which keeps the network aware of the current location of the mobile nodes. Recently, a dynamic hierarchical mobility management strategy for mobile IP networks (DHMIP) has been proposed to reduce home registrations costs. However, this strategy induces a packet delivery delay and increases the risk of packet loss. In this paper, we propose an enhanced version of the dynamic hierarchical strategy that reduces the packet delivery delay and minimizes the risk of packet loss. Preliminary results obtained from simulations are promising. They show that the enhanced version outperforms the original dynamic hierarchical mobility management strategy version.
Abstract: The ionization energy in semiconductor
systems in nano scale was investigated by using effective mass
approximation. By introducing the Hamiltonian of the system, the
variational technique was employed to calculate the ground state and
the ionization energy of a donor at the center and in the case that the
impurities are randomly distributed inside a cubic quantum well. The
numerical results for GaAs/GaAlAs show that the ionization energy
strongly depends on the well width for both cases and it decreases as
the well width increases. The ionization energy of a quantum wire
was also calculated and compared with the results for the well.
Abstract: Although women have merit in their jobs, they still
are located very few in the top management in many sectors. There
are many causes of such situation. Such a situation creates obstacles;
especially invisible ones are called “glass ceiling syndrome”. Also,
studies which handle this subject in academic community are very
few. The aim of this research is to reach the results about glass
ceiling obstacles in terms of female teaching staff (academics)
working in higher education institutions. To this end, our study was
performed on female academics working at Selcuk University, Konya
/ Turkey. Our study's main aim can be expressed as to determine
whether there are glass ceiling obstacles for female academics
working at the higher education institution in question, to measure
their glass ceiling perceptions and, thus, to identify what the glass
ceiling barrier components for them to promotion to senior
management positions are.
Abstract: The objective of this work was to examine the
changes in the microstructure and macro physical properties caused
by the carbonation of normalised CEM II mortar. Samples were
prepared and subjected to accelerated carbonation at 20°C, 65%
relative humidity and 20% CO2 concentration. On the microstructure
scale, the evolutions of the cumulative pore volume, pore size
distribution, and specific surface area during carbonation were
calculated from the adsorption desorption isotherms of nitrogen. We
also examined the evolution of macro physical properties such as the
porosity accessible to water, the gas permeability, and thermal
conductivity. The conflict between the results of nitrogen porosity
and water porosity indicated that the porous domains explored using
these two techniques are different and help to complementarily
evaluate the effects of carbonation. This is a multi-scale study where
results on microstructural changes can help to explain the evolution
of macro physical properties.
Abstract: The optimal extraction condition of dried
Echinocactus grusonii powder was studied. The three independent
variables are raw material drying temperature, extraction
temperature, and extraction time. The dependent variables are both
yield percentage of crude extract and total phenolic quantification as
gallic acid equivalent in crude extract. The experimental design was
based on central composite design. Highest yield percentage of crude
extract could get from extraction condition at raw material drying
temperature at 60°C, extraction temperature at 15°C, and extraction
time for 25 min °C. Moreover, the crude extract with highest phenolic
occurred by extraction condition of raw material drying temperature
at 60°C, extraction temperature at 35 °C, and extraction lasting 25
min.
Abstract: In this paper, an overview of the radio over fiber (RoF) technology is provided. Obstacles for reducing the capital and operational expenses in the existing systems are discussed in various perspectives. Some possible RoF deployment scenarios for WiMAX
data transmission are proposed as a means for capital and operational
expenses reduction. IEEE 802.16a standard based end-to-end physical layer model is simulated including intensity modulated direct detection RoF technology. Finally the feasibility of RoF
technology to carry WiMAX signals between the base station and the
remote antenna units is demonstrated using the simulation results.
Abstract: In the present work, study of the vibration of thin cylindrical shells made of a functionally gradient material (FGM) composed of stainless steel and nickel is presented. Material properties are graded in the thickness direction of the shell according to volume fraction power law distribution. The objective is to study the natural frequencies, the influence of constituent volume fractions and the effects of boundary conditions on the natural frequencies of the FG cylindrical shell. The study is carried out using third order shear deformation shell theory. The governing equations of motion of FG cylindrical shells are derived based on shear deformation theory. Results are presented on the frequency characteristics, influence of constituent volume fractions and the effects of free-free boundary conditions.
Abstract: While to minimize the overall project cost is always
one of the objectives of construction managers, to obtain the
maximum economic return is definitely one the ultimate goals of the
project investors. As there is a trade-off relationship between the
project time and cost, and the project delivery time directly affects the
timing of economic recovery of an investment project, to provide a
method that can quantify the relationship between the project delivery
time and cost, and identify the optimal delivery time to maximize
economic return has always been the focus of researchers and
industrial practitioners. Using genetic algorithms, this study
introduces an optimization model that can quantify the relationship
between the project delivery time and cost and furthermore, determine
the optimal delivery time to maximize the economic return of the
project. The results provide objective quantification for accurately
evaluating the project delivery time and cost, and facilitate the
analysis of the economic return of a project.
Abstract: Offset mismatch, gain mismatch, and time-skew error between time-interleaved channels limit the performance of time-interleaved analog-to-digital converters (TIADC). This paper focused on the time-skew error. A new technique for calibrating time-skew error in M-channels TIADC is described, and simulation results are also presented.
Abstract: With a growing number of digital libraries and other
open education repositories being made available throughout the
world, effective search and retrieval tools are necessary to access the
desired materials that surpass the effectiveness of traditional, allinclusive
search engines. This paper discusses the design and use of
Folksemantic, a platform that integrates OpenCourseWare search,
Open Educational Resource recommendations, and social network
functionality into a single open source project. The paper describes
how the system was originally envisioned, its goals for users, and
data that provides insight into how it is actually being used. Data
sources include website click-through data, query logs, web server
log files and user account data. Based on a descriptive analysis of its
current use, modifications to the platform's design are recommended
to better address goals of the system, along with recommendations
for additional phases of research.
Abstract: Non-premixed turbulent combustion Computational Fluid Dynamics (CFD) has been carried out in a simplified methanefuelled coaxial jet combustor employing Large Eddy Simulation (LES). The objective of this study is to evaluate the performance of LES in modelling non-premixed combustion using a commercial software, FLUENT, and investigate the effects of the grid density and chemistry models employed on the accuracy of the simulation results. A comparison has also been made between LES and Reynolds Averaged Navier-Stokes (RANS) predictions. For LES grid sensitivity test, 2.3 and 6.2 million cell grids are employed with the equilibrium model. The chemistry model sensitivity analysis is achieved by comparing the simulation results from the equilibrium chemistry and steady flamelet models. The predictions of the mixture fraction, axial velocity, species mass fraction and temperature by LES are in good agreement with the experimental data. The LES results are similar for the two chemistry models but influenced considerably by the grid resolution in the inner flame and near-wall regions.
Abstract: In this paper, we present some new upper bounds for
the spectral radius of iterative matrices based on the concept of
doubly α diagonally dominant matrix. And subsequently, we give
two examples to show that our results are better than the earlier ones.
Abstract: This paper presents the voltage regulation scheme of
D-STATCOM under three-phase faults. It consists of the voltage
detection and voltage regulation schemes in the 0dq reference. The
proposed control strategy uses the proportional controller in which
the proportional gain, kp, is appropriately adjusted by using genetic
algorithms. To verify its use, a simplified 4-bus test system is situated
by assuming a three-phase fault at bus 4. As a result, the DSTATCOM
can resume the load voltage to the desired level within
1.8 ms. This confirms that the proposed voltage regulation scheme
performs well under three-phase fault events.
Abstract: Under the variation of crude oil price and the impact of
greenhouse effect, it is urgent to find a potential alternative fuel.
Among these alternative fuels, non edible plant oils are the most
potential ones, because they don-t have the problem of food and
cropland competitions. Among the non-edible plant oils, Jatropha oil
is the most potential one. Jatropha oil is non-eatable oil and has good
oil quality and low temperature performance. It has potential to
become one of the most competitive biomass crude oils. The crude
plant oil will be blended with diesel fuel to be tested in a power
generator. The international collaboration between Taiwan and
Indonesia on the production of Jatropha in Indonesia will also be
presented in this study.
Abstract: The significance of environmental protection is wellknown in today's world. The execution of any program depends on sufficient knowledge and required familiarity with environment and its pollutants. Taking advantage of a systematic method, as a new science, in environmental planning can solve many problems. In this article, air pollution in Tehran and its relationship with health and population growth have been analyzed using dynamic systems. Firstly, by using casual loops, the relationship between the parameters effective on air pollution in Tehran were taken into consideration, then these casual loops were turned into flow diagrams [6], and finally, they were simulated using the software Vensim [16]in order to conclude what the effect of each parameter will be on air pollution in Tehran in the next 10 years, how changing of one or more parameters influences other parameters, and which parameter among all other parameters requires to be controlled more.
Abstract: To enhance installation security, a LNG storage in Rudong of Jiangsu province was adopted as a practical work, and it was analyzed by nonlinear finite element method to research overall and local stability performance, as well as the stress and deformation under the action of wind load and self-weight. Results indicate that deformation is tiny when steel mesh maintains as an overall ring, and stress caused by vertical bending moment and tension of bottom tie wire are also in the safe range. However, axial forces of lap reinforcement in adjacent steel mesh exceed the ultimate bearing capacity of tie wire. Hence, tie wires are ruptured; single mesh loses lateral connection and turns into monolithic status as the destruction of overall structure. Further more, monolithic steel mesh is led to collapse by the damage of bottom connection. So, in order to prevent connection failure and enhance installation security, the overlapping parts of steel mesh should be taken more reliable measures.
Abstract: As the advancement of technology, online shopping channel develops rapidly in recent years. According to the report of Taiwan Network Information Center, there are almost eighty percents of internet population shopping in online channel. Synthesizing insights from the previous research, this study develops the conceptual model to integrate Theory of Perceived Risk (TPR) and Technology Acceptance Model (TAM) to apply in online shopping. Using data collected from 637 respondents from online survey website, we use structural equation modeling to test measurement and structural models. The results suggest the need for consideration of perceived risk as an antecedent in the Technology Acceptance Model. The limitations and implications are discussed.
Abstract: This study aims to assess the potential of solar energy technology for improving access to water and hence the livelihood strategies of rural communities in Baja California Sur, Mexico. It focuses on livestock ranches and photovoltaic water-pumptechnology as well as other water extraction methods. The methodology used are the Sustainable Livelihoods and the Appropriate Technology approaches. A household survey was applied in June of 2006 to 32 ranches in the municipality, of which 22 used PV pumps; and semi-structured interviews were conducted. Findings indicate that solar pumps have in fact helped people improve their quality of life by allowing them to pursue a different livelihood strategy and that improved access to water -not necessarily as more water but as less effort to extract and collect it- does not automatically imply overexploitation of the resource; consumption is based on basic needs as well as on storage and pumping capacity. Justification for such systems lies in the avoidance of logistical problems associated to fossil fuels, PV pumps proved to be the most beneficial when substituting gasoline or diesel equipment but of dubious advantage if intended to replace wind or gravity systems. Solar water pumping technology-s main obstacle to dissemination are high investment and repairs costs and it is therefore not suitable for all cases even when insolation rates and water availability are adequate. In cases where affordability is not an obstacle it has become an important asset that contributes –by means of reduced expenses, less effort and saved time- to the improvement of livestock, the main livelihood provider for these ranches.
Abstract: Optimization of a microwave-assisted extraction of cherry laurel (Prunus laurocerasus) fruit using methanol was studied. The influence of process parameters (microwave power, plant material-to-solvent ratio and the extraction time) on the extraction efficiency were optimized by using response surface methodology. The predicted maximum yield of extractive substances (41.85 g/100 g fresh plant material) was obtained at microwave power of 600 W and plant material to solvent ratio of 0.2 g/cm3 after 26 minutes of extraction, while a mean value of 40.80±0.41 g/100 g fresh plant material was obtained from laboratory experiments. This proves applicability of the model in predicting optimal extraction conditions with minimal laborious and time consuming. The results indicated that all process parameters were effective on the extraction efficiency, while the most important factor was extraction time. In order to rationalize production the optimal economical condition which gave a large total extract yield with minimal energy and solvent consumption was found.