Mode i stress intensity factors of slanted cracks

The solutions of stress intensity factors of slanted cracks in plain strain plate are hard to find in open literature. There are some previous solutions of stress intensity factors available, however they are not studied completed except for the case of plain stress. The slanted cracks are modelled numerically using ANSYS finite element program. There are ten slanted angles and seven relative crack depths are used and the plate containing cracks is assumed to fulfil the plain strain condition. The plate is then forced uni-axially the stress intensity factors are determined according to the displacement extrapolation method. Based on the numerical analysis, it is found that slanted angles have inverse effects on the behaviour of stress intensity factors. Increasing such angles capable to reduce the mode I stress intensity factors. On the other hand, it is also enhanced the capability of mode II stress intensity factors at the crack tip. Due to difficulty of determining stress intensity factors numerically, a regression technique is used to formulate mathematical expressions which are capable to predict the stress intensity factors in reasonable accuracies

Churn classification model for local telecommunication company based on rough set theory

Customer care plays an important role in a company especially in managing churn for Telecommunication Company. Churn is perceived as the behaviour of a customer to leave or to terminate a service. This behaviour causes the loss of profit to companies because acquiring new customer requires higher investment compared to retaining existing ones. Thus, it is necessary to consider an efficient classification model to reduce the rate of churn. Hence, the purpose of this paper is to propose a new classification model based on the Rough Set Theory to classify customer churn. The results of the study show that the proposed Rough Set classification model outperforms the existing models and contributes to significant accuracy improvement.Keywords: customer churn; classification model; telecommunication industry; data mining;rough set

Current Development in LTE/LTE-Advanced: Adaptive-Proportional Fair Scheduling in LTE

This paper provides analytical expressions to validate and evaluate the performance of Long Term Evolution (LTE) network in terms of throughput, spectral efficiency and SINR which are subjected to the constraint of proportional fairness amongst users from the EnodeB. The proportional fair scheduling (PFS) algorithm is mainly focused on bandwidth allocation criterion in LTE networks for supporting high resource utilization while maintaining high fairness among network flows to each distributed User Equipment (UE). The most challenge of a PFS problem is the lack of analytic expression. Though the PFS algorithm has been a research focus for some time, the results are mainly obtained from computer simulations. The current existing research applies a simplified form of the PFS preference metric and the given analytic expression is capable to support certain cases. The proposed model is refined with respect to uniform modulation and coding, as applied in LTE networks. Besides, we show that our models are approximate estimates for the performance of rate-based proportional fair scheduling, while they outperform some simpler prediction models from related work significantl

Q-switched fiber laser based on CdS quantum dots as a saturable absorber

In this work, a Q-switched fiber laser is demonstrated using quantum dots (QDs) cadmium sulfide (CdS) as a saturable absorber (SA) in an erbium-doped fiber laser (EDFL) system. The QD CdS is synthesized via the microwave hydrothermal assisted method and embedded into polyvinyl alcohol (PVA). The QD CdS/PVA matrix film is sandwiched in between two fiber ferrules by a fiber adapter. The generation of Q-switched fiber laser having a repetition rate, a pulse width, and a peak-topeak pulse duration of 75.19 kHz, 1.27 μs, and 13.32 μs, respectively. The maximum output power of 3.82 mW and maximum pulse energy of 50.8 nJ are obtained at the maximum pump power of 145.9 mW. The proposed design may add to the alternative material of Q-switched fiber laser generation, which gives a high stability output performance by using quantum dots material as a saturable absorber

LIS input to degree programmes offered at the Faculty of Computer Science and Information Technology, University of Malaya

The Faculty of Computer Science and Information Technology (FCSIT) at the University of Malaya was established in 1994 and currently offers two main undergraduate degree programmes (Bachelor of Computer Science [BCS] and Bachelor of Information Technology) and four Master programmes (Master of Computer Science, Master of Software Engineering, Master of Information Technology and Master of Library and Information Science [MLIS]). Each degree programmes provide opportunities for specialisation. The Bachelor in Computer Science offers specialisation in Computer Systems and Networks, Management Information Systems, Software Engineering and Artificial Intelligence. The Bachelor of Information Technology (BIT) provides special modules biased towards IT applications in Financial Management, Multimedia and Information Science This paper focuses on LIS input to the BIT (Information Science) and MLIS degree programmes offered at FCSIT. Five academic staffs are responsible for planning and teaching the LIS components in these two programmes. The BIT (IS) degree is a three year programme, that aims to expose information technologists to the types and characteristics of information sources and services and understand the behaviour of information users. This would enable these IT professionals develop and manage meaningful and usable information systems, product and services. Hence, the BIT (IS) graduates could function in organisations that manages knowledge or information portals and systems. The MLIS programme offered at the Faculty is about 6 years old and its curriculum have been revised in the year 2000 to cater for current needs of information professionals. The present programme tries to provide a balance between LIS contents and a working knowledge of planning and managing information systems. Thus, the core courses offered stay close to basic LIS information subjects (information sources, services management, organisation, storage, retrieval and IT applications). The difference can be seen in the elective courses where more IT related courses are offered (Information systems development, multimedia systems, basic visual programming, knowledge management, electronic publishing, digital libraries, Internet resource management, and human factors in information systems). For balance more traditional LIS electives are maintained (Collection development, Information sources in specific fields, individual study, and library practicum). On the whole FCSIT have also emphasized on research and the development of useful systems. Each undergraduate are required to produce a research report and develop a fully running systems as part of the requirement for the degree that comprises nine credit hours. In this respect, LIS academic staff have taken advantage of this situation by encouraging undergraduates (BCS and BIT) to development LIS related projects that ranged from library automated systems for small libraries, graphical based library systems for children, bar-coding generating system, knowledge portals, adviser systems, digital library hosting systems and content databases. There is an urgent need for collaboration between faculty and libraries, information centres, as well publishers in ensuring the systems developed are knowledge or content rich. This collaboration places LIS professionals as an active partner and content provider for information-rich local-content knowledge systems. A brief description of LIS systems that have been developed is appended