Abstract: This paper describes the design of a voltage based maximum power point tracker (MPPT) for photovoltaic (PV) applications. Of the various MPPT methods, the voltage based method is considered to be the simplest and cost effective. The major disadvantage of this method is that the PV array is disconnected from the load for the sampling of its open circuit voltage, which inevitably results in power loss. Another disadvantage, in case of rapid irradiance variation, is that if the duration between two successive samplings, called the sampling period, is too long there is a considerable loss. This is because the output voltage of the PV array follows the unchanged reference during one sampling period. Once a maximum power point (MPP) is tracked and a change in irradiation occurs between two successive samplings, then the new MPP is not tracked until the next sampling of the PV array voltage. This paper proposes an MPPT circuit in which the sampling interval of the PV array voltage, and the sampling period have been shortened. The sample and hold circuit has also been simplified. The proposed circuit does not utilize a microcontroller or a digital signal processor and is thus suitable for low cost and low power applications.
Abstract: The mixing behaviors of dry and wet granular
materials in gas fluidized bed systems were investigated
computationally using the combined Computational Fluid Dynamics
and Discrete Element Method (CFD-DEM). Dry particles were
observed to mix fairly rapidly during the fluidization process due to
vigorous relative motions between particles induced by the flow of
gas. In contrast, due to the presence of strong cohesive forces arising
from capillary liquid bridges between wet particles, the mixing
efficiencies of wet granular materials under similar operating
conditions were observed to be reduced significantly.
Abstract: Due to the call of global warming effects, city planners aim at actions for reducing carbon emission. One of the approaches is to promote the usage of public transportation system toward the transit-oriented-development. For example, rapid transit system in Taipei city and Kaohsiung city are opening. However, until November 2008 the average daily patronage counted only 113,774 passengers at Kaohsiung MRT systems, much less than which was expected. Now the crucial questions: how the public transport competes with private transport? And more importantly, what factors would enhance the use of public transport? To give the answers to those questions, our study first applied regression to analyze the factors attracting people to use public transport around cities in the world. It is shown in our study that the number of MRT stations, city population, cost of living, transit fare, density, gasoline price, and scooter being a major mode of transport are the major factors. Subsequently, our study identified successful and unsuccessful cities in regard of the public transport usage based on the diagnosis of regression residuals. Finally, by comparing transportation strategies adopted by those successful cities, our conclusion stated that Kaohsiung City could apply strategies such as increasing parking fees, reducing parking spaces in downtown area, and reducing transfer time by providing more bus services and public bikes to promote the usage of public transport.
Abstract: Tourism industries are rapidly increased for the last
few years especially in Malaysia. In order to attract more tourists,
Malaysian Governance encourages any effort to increase Malaysian
tourism industry. One of the efforts in attracting more tourists in
Malacca, Malaysia is a duck tour. Duck tour is an amphibious
sightseeing tour that works in two types of engines, hence, it required
a huge cost to operate and maintain the vehicle. To other country, it is
not so new but in Malaysia, it is just introduced, thus it does not have
any systematic routing yet. Therefore, this paper proposed an
optimization technique to formulate and schedule this tour to
minimize the operating costs by considering it into Travelling
Salesman Problem (TSP). The problem is then can be solved by one
of the optimization technique especially meta-heuristics approach
such as Tabu Search (TS) and Reactive Tabu Search (RTS).
Abstract: In mobile computing environments, there are many
new non existing problems in the distributed system, which is
consisted of stationary hosts because of host mobility, sudden
disconnection by handoff in wireless networks, voluntary
disconnection for efficient power consumption of a mobile host, etc.
To solve the problems, we proposed the architecture of Partial
Connection Manager (PCM) in this paper. PCM creates the limited
number of mobile agents according to priority, sends them in parallel
to servers, and combines the results to process the user request rapidly.
In applying the proposed PCM to the mobile market agent service, we
understand that the mobile agent technique could be suited for the
mobile computing environment and the partial connection problem
management.
Abstract: OpenMP is an API for parallel programming model of shared memory multiprocessors. Novice OpenMP programmers often produce the code that compiler cannot find human errors. It was investigated how compiler coped with the common mistakes that can occur in OpenMP code. The latest version(4.4.3) of GCC is used for this research. It was found that GCC compiled the codes without any errors or warnings. In this paper the programming aid tool is presented for OpenMP programs. It can check 12 common mistakes that novice programmer can commit during the programming of OpenMP. It was demonstrated that the programming aid tool can detect the various common mistakes that GCC failed to detect.
Abstract: This paper presents a research conducted to investigate the effect of mixing process on polypropylene (PP) modified bitumen mixed with well graded aggregate to form modified bituminous concrete mix. Two mode of mixing, namely dry and wet with different concentration of polymer polypropylene was used with 80/100 pen bitumen, to evaluate the bituminous concrete mix properties. Three percentages of polymer varying from 1-3% by the weight of bitumen was used in this study. Three mixes namely control mix, wet mix and dry mix were prepared. Optimum binder content was calculated considering Marshall Stability, flow, air voids and Marshall Quotient at different bitumen content varying from 4% - 6.5% for control, dry and wet mix. Engineering properties thus obtained at the calculated optimum bitumen content revealed that wet mixing process is advantageous in comparison to dry mixing as it increases the stiffness of the mixture with the increase in polymer content in bitumen. Stiffness value for wet mix increases with the increase in polymer content which is beneficial in terms of rutting. 1% PP dry mix also shows enhanced stiffness, with the air void content limited to 4%.The flow behaviour of dry mix doesn't indicate any major difference with the increase in polymer content revealing that polymer acting as an aggregate only without affecting the viscosity of the binder in the mix. Polypropylene (PP) when interacted with 80 pen base bitumen enhances its performance characteristics which were brought about by altered rheological properties of the modified bitumen. The decrease in flow with the increase in binder content reflects the increase in viscosity of binder which induces the plastic flow in the mix. Workability index indicates that wet mix were easy to compact up to desired void ratio in comparison to dry mix samples.
Abstract: The practice of burying the solid waste under the ground is one of the waste disposal methods and dumping is known as an ultimate method in the fastest-growing cities like Rasht city in Iran. Some municipalities select the solid waste landfills without feasibility studies, programming, design and management plans. Therefore, several social and environmental impacts are created by these sites. In this study, the suitability of solid waste landfill in Rasht city, capital of Gilan Province is reviewed using Regional Screening Method (RSM), Geographic Information System (GIS) and Analytical Hierarchy Process (AHP). The results indicated that according to the suitability maps, the value of study site is midsuitable to suitable based on RSM and mid-suitable based on AHP.
Abstract: Relational databases are often used as a basis for persistent storage of ontologies to facilitate rapid operations such as search and retrieval, and to utilize the benefits of relational databases management systems such as transaction management, security and integrity control. On the other hand, there appear more and more OWL files that contain ontologies. Therefore, this paper proposes to extract ontologies from OWL files and then store them in relational databases. A prerequisite for this storing is transformation of ontologies to relational databases, which is the purpose of this paper.
Abstract: This paper was to study the clothes dryer using waste
heat from a split type air conditioner with a capacity of 12,648 btu/h.
The drying chamber had a minimum cross section area with the size
of 0.5 x 1.0 m2. The chamber was constructed by sailcloth and was
inside folded with aluminium foil. Then, it was connected to the
condensing unit of an air conditioner. The experiment was carried out
in two aspects which were the clothes drying with and without
auxiliary fan unit. The results showed that the drying rate of clothes
in the chamber installed with and without auxiliary fan unit were
2.26 and 1.1 kg/h, respectively. In case of the chamber installed with
a auxiliary fan unit, the additional power of 0.011 kWh was
consumed and the drying rate was higher than that of clothes drying
without auxiliary fan unit. Without auxiliary fan unit installation, no
energy was required but there was a portion of hot air leaks away
through the punctured holes at the wall of the drying chamber, hence
the drying rate was dropped below. The drying rate of clothes drying
using waste heat was higher than natural indoor drying and
commercial dryer which their drying rate were 0.17 and 1.9 kg/h,
respectively. It was noted that the COP of the air conditioner did not
change during the operating of clothes drying.
Abstract: Drop-in of R-22 alternatives in refrigeration and air conditioning systems requires a redesign of system components to improve system performance and reliability with the alternative refrigerants. The present paper aims at design adiabatic capillary tubes for R-22 alternatives such as R-417A, R-422D and R-438A. A theoretical model has been developed and validated with the available experimental data from literature for R-22 over a wide range of both operating and geometrical parameters. Predicted lengths of adiabatic capillary tube are compared with the lengths of the capillary tube needed under similar experimental conditions and majority of predictions are found to be within 4.4% of the experimental data. Hence, the model has been applied for R-417A, R- 422D and R-438A and capillary tube selection charts and correlations have been computed. Finally a comparison between the selected refrigerants and R-22 has been introduced and the results showed that R-438A is the closest one to R-22.
Abstract: Wireless Sensor Networks (WSNs) have attracted the attention of many researchers. This has resulted in their rapid integration in very different areas such as precision agriculture,environmental monitoring, object and event detection and military surveillance. Due to the current WSN characteristics this technology is specifically useful in industrial areas where security, reliability and autonomy are basic, such as nuclear power plants, chemical plants, and others. In this paper we present a system based on WSNs to monitor environmental conditions around and inside a nuclear power plant, specifically, radiation levels. Sensor nodes, equipped with radiation sensors, are deployed in fixed positions throughout the plant. In addition, plant staff are also equipped with mobile devices with higher capabilities than sensors such as for example PDAs able to monitor radiation levels and other conditions around them. The system enables communication between PDAs, which form a Mobile Ad-hoc Wireless Network (MANET), and allows workers to monitor remote conditions in the plant. It is particularly useful during stoppage periods for inspection or in the event of an accident to prevent risk situations.
Abstract: It can be said that the business sector is faced with a range of challenges–a rapidly changing business environment, an increase and diversification of customers- demands and the consequent need for quick response–for having in place flexible management and production info systems. As a matter of fact, many manufacturers have adopted production info management systems such as MES and ERP. Nevertheless, managers are having difficulties obtaining ever-changing production process information in real time, or responding quickly to any change in production related needs on the basis of such information. This is because they rely on poor production info systems which are not capable of providing real-time factory settings. If the manufacturer doesn-t have a capacity for collecting or digitalizing the 4 Ms (Man, Machine, Material, Method), which are resources for production, on a real time basis, it might to difficult to effectively maintain the information on production process. In this regard, this paper will introduce some new alternatives to the existing methods of collecting the 4 Ms in real time, which are currently comprise the production field.
Abstract: Enterprise applications are complex systems that are hard to develop and deploy in organizations. Although software application development tools, frameworks, methodologies and patterns are rapidly developing; many projects fail by causing big costs. There are challenging issues that programmers and designers face with while working on enterprise applications. In this paper, we present the three of the significant issues: Architectural, technological and performance. The important subjects in each issue are pointed out and recommendations are given. In architectural issues the lifecycle, meta-architecture, guidelines are pointed out. .NET and Java EE platforms are presented in technological issues. The importance of performance, measuring performance and profilers are explained in performance issues.
Abstract: The move towards internationalization of accounting encountered a great boost, when in 2002 EU delegated the IASB to provide the accounting standards to be applied inside its frontiers. Among the incentives of the standardization of accounting on the international level, is the reduction of the cost of capital. Romania made the move towards IFRS before EU, when the country was not yet a member of it. Even if this made Romania a special case, it was scarcely approached. The leak of real data is usually the reason for avoiding. The novelty of this paper is that it offers an insight from the reality of Romanian companies and their view regarding the IFRS. The paper is based on a survey that the authors made among the companies listed on the first two tiers of the Bucharest Stock Exchange (BSE), which are basically, the most important companies in the country.
Abstract: With the rapid usage of portable devices mobility in
IP networks becomes more important issue in the recent years. IETF
standardized Mobile IP that works in Network Layer, which involves
tunneling of IP packets from HA to Foreign Agent. Mobile IP suffers
many problems of Triangular Routing, conflict with private
addressing scheme, increase in load in HA, need of permanent home
IP address, tunneling itself, and so on. In this paper, we proposed
mobility management in Application Layer protocol SIP and show
some comparative analysis between Mobile IP and SIP in context of
mobility.
Abstract: Product Lead Time (PLT) is the period of time from
receiving a customer's order to delivering the final product. PLT is an
indicator of the manufacturing controllability, efficiency and
performance. Due to the explosion in the rate of technological
innovations and the rapid changes in the nature of manufacturing
processes, manufacturing firms can bring the new products to market
quicker only if they can reduce their PLT and speed up the rate at
which they can design, plan, control, and manufacture. Although
there is a substantial body of research on manufacturing relating to
cost and quality issues, there is no much specific research conducted
in relation to the formulation of PLT, despite its significance and
importance. This paper analyzes and formulates PLT which can be
used as a guideline for achieving the shorter PLT. Further more this
paper identifies the causes of delay and factors that contributes to the
increased product lead-time.
Abstract: This research aimed to find out the determining
factors for ISO 14001 EMS implementation among SMEs in
Malaysia from the Resource based view. A cross-sectional approach
using survey was conducted. A research model been proposed which
comprises of ISO 14001 EMS implementation as the criterion
variable while physical capital resources (i.e. environmental
performance tracking and organizational infrastructures), human
capital resources (i.e. top management commitment and support,
training and education, employee empowerment and teamwork) and
organizational capital resources (i.e. recognition and reward,
organizational culture and organizational communication) as the
explanatory variables. The research findings show that only
environmental performance tracking, top management commitment
and support and organizational culture are found to be positively and
significantly associated with ISO 14001 EMS implementation. It is
expected that this research will shed new knowledge and provide a
base for future studies about the role played by firm-s internal
resources.
Abstract: The main purpose of this research paper was to study
the requirements for human capital development in order to be ready
for ASEAN Community. Thai education institutions are encountering
a challenging course of change to be effective members of ASEAN
Economic Community (AEC) in 2015. It was vital that everyone and
every organization participate in the process of becoming part of the
ASEAN community, a pluralistic society. Thai universities will be
required to partake in the human capital development in a variety of
fields. In order to assist the whole nation to enhance potential
development, there was a need to collaborate with other ASEAN
leading universities to do researches to ameliorate the qualifications
and capabilities of university management, administers, professors,
and staffs.
Abstract: Optical 3D measurement of objects is meaningful in
numerous industrial applications. In various cases shape acquisition
of weak textured objects is essential. Examples are repetition parts
made of plastic or ceramic such as housing parts or ceramic bottles as
well as agricultural products like tubers. These parts are often
conveyed in a wobbling way during the automated optical inspection.
Thus, conventional 3D shape acquisition methods like laser scanning
might fail. In this paper, a novel approach for acquiring 3D shape of
weak textured and moving objects is presented. To facilitate such
measurements an active stereo vision system with structured light is
proposed. The system consists of multiple camera pairs and auxiliary
laser pattern generators. It performs the shape acquisition within one
shot and is beneficial for rapid inspection tasks. An experimental
setup including hardware and software has been developed and
implemented.