A Low Cost Two-Tier Architecture Model For High Availability Clusters Application Load Balancing

This article proposes a design and implementation of a low cost two-tier architecture model for high availability cluster combined with load-balancing and shared storage technology to achieve desired scale of three-tier architecture for application load balancing e.g. web servers. The research work proposes a design that physically omits Network File System (NFS) server nodes and implements NFS server functionalities within the cluster nodes, through Red Hat Cluster Suite (RHCS) with High Availability (HA) proxy load balancing technologies. In order to achieve a low-cost implementation in terms of investment in hardware and computing solutions, the proposed architecture will be beneficial. This system intends to provide steady service despite any system components fails due to uncertainly such as network system, storage and applications.Comment: Load balancing, high availability cluster, web server cluster

Comparative Study on Agile software development methodologies

Today-s business environment is very much dynamic, and organisations are constantly changing their software requirements to adjust with new environment. They also demand for fast delivery of software products as well as for accepting changing requirements. In this aspect, traditional plan-driven developments fail to meet up these requirements. Though traditional software development methodologies, such as life cycle-based structured and object oriented approaches, continue to dominate the systems development few decades and much research has done in traditional methodologies, Agile software development brings its own set of novel challenges that must be addressed to satisfy the customer through early and continuous delivery of the valuable software. It is a set of software development methods based on iterative and incremental development process, where requirements and development evolve through collaboration between self-organizing, cross-functional teams that allows rapid delivery of high quality software to meet customer needs and also accommodate changes in the requirements. In this paper, we significantly identify and describe the major factors, that Agile development approach improves software development process to meet the rapid changing business environments. We also provide a brief comparison of agile development methodologies with traditional systems development methodologies, and discuss current state of adopting agile methodologies. We speculate that from the need to satisfy the customer through early and continuous delivery of the valuable software, Agile software development is emerged as an alternative to traditional plan-based software development methods. The purpose of this paper, is to provide an in-depth understanding, the major benefits of agile development approach to software development industry, as well as provide a comparison study report of ASDM over TSDM.Comment: 25 pages, 25 images, 86 references used, with authors biographie

Software Reliability Models

The problem considered here is the building of Non-homogeneous Poisson Process (NHPP) model. Currently existing popular NHPP process models like Goel-Okumoto (G-O) and Yamada et al models suffer from the drawback that the probability density function of the inter-failure times is an improper density function. This is because the event no failure in (0, oo] is allowed in these models. In real life situations we cannot draw sample(s) from such a population and also none of the moments of inter-failure times exist. Therefore, these models are unsuitable for modelling real software error data. On the other hand if the density function of the inter-failure times is made proper by multiplying with a constant, then we cannot assume finite number of expected faults in the system which is the basic assumption in building the software reliability models. Taking these factors into consideration, we have introduced an extra parameter, say c, in both the G -0 and Yamada et al models in order to get a new model. We find that a specific value of this new parameter gives rise to a proper density for inter-failure times. The G -0 and Yamada et al models are special cases of these models corresponding to c = 0. This raises the question - “Can we do better than existing G -0 and Yamada et al models when 0 \u3c c \u3c 1 ?”. The answer is ‘yes’. With this objective, the behavior of the software failure counting process { N ( t ) , t \u3e 0} has been studied. Several measures, such as the number of failures by some prespecified time, the number of errors remaining in the system at a future time, distribution of remaining number of faults in the system and reliability during a mission have been proposed in this research. Maximum likelihood estimation method was used to estimate the parameters. Sufficient conditions for the existence of roots of the ML equations were derived. Some of the important statistical aspects of G -0 and Yamada et al models, like conditions for the existence and uniqueness of the ML equations, were not worked out so far in the literature. We have derived these conditions and proved uniqueness of the roots for these models. Finally four different sets of actual failure time data were analyzed. i

Reactions of Sulfur Fluorides and Other Fluorides

Abstract Not Provided

Impact of information technology in trade facilitation on small and medium-sized enterprises in Bangladesh

This paper focuses specifically on one particular aspect of trade facilitation in the context of Bangladesh, i.e., impact on SMEs of IT in trade facilitation. It is hoped that the policy recommendations offered in this paper will be useful in furthering the cause of SME internationalization in Bangladesh.Trade Facilitation, Bangladesh, SMEs, Information Technology

Impact of the Global Economic Crisis on the Employment and Labour Market of Bangladesh A Preliminary Assessment

ILOs initiative to assess the impact of the financial crisis on employment and labour market of South Asian economies and develop alternative policy responses to mitigate the adverse social effects of the crisis on the world of work, especially the vulnerable groups, is timely and addresses a key emerging concern. The Bangladesh country study is part of this South Asia wide study, and the Centre for Policy Dialogue (CPD) has been entrusted with carrying out this part of the regional study. The study will be carried out in two phases : a rapid assessment study to be followed by a more indepth study of the impact of recession on the labour market of Bangladesh which will focus on required policy responses.Bangladesh, Global Economic Crisis, Employement, Labour Market

Studies in Trade and Investment: The Development Impact of Information Technology in Trade Facilitation

In Bangladesh, SMEs are very important players in the economy. About 90 per cent of all industrial units in Bangladesh are SMEs, which generate some 25 per cent of the gross domestic product (GDP), employ about 31 million people and provide 75 per cent of household income. There is no denying that SMEs act as the driver of the economy and are very important for national economic and social development. They serve as employers creating new jobs and providers of products for daily needs. They also act as stewards over employees and the community. However, SMEs in developing and least developed countries face considerable barriers in running their businesses and are often constrained financially and technologically. This includes inadequate and/or complex sets of policies by the respective governments. Such impediments largely contribute to the under-involvement of SMEs in international markets. This is where the nature and extent of SME participation in the global trading system needs to be highlighted. Trade facilitation is thus a crucial factor in providing SMEs with access to global markets.Trade facilitation, ICT, IT, SMEs, international trade, Bangladesh