Browsing by Author "Pieris, D."

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Comparative Study on the Popularity of Fixed and Mobile Internet Connections in Sri Lanka: Study Based on Western Province
(Faculty of Commerce and Management Studies, University of Kelaniya, Sri Lanka, 2016) Karunaratne, R.N.P.; Pieris, D.
Internet has grown from a nascent technology to a tool that transforms people’s lifestyle and business world. In Sri Lanka, as per statistics published by Telecommunication Regulatory Commission, number of Mobile Internet subscribers is higher than Fixed Internet subscribers despite the heavy investments by Fixed Internet Service Providers (ISP). The purpose of this comparative study is to examine the factors leading to adoption or popularity of Mobile Internet over Fixed Internet connections. A survey was distributed to a randomly selected population residing in Western province. Out of the 150 total respondents, 121 valid responses were analysed. The results in this study revealed that Technicality of Mobile Internet over Fixed Internet (TEC) and Perceived Fee of Mobile Internet over Fixed Internet (FEE) are the factors that influence Behavioural Intention to Adopt Mobile Internet over Fixed Internet (BIA). TEC, the highest correlated item with the BIA indicated that the adopters sought for straight forward connectivity and speed in an internet connection. Dynamic pricing, an indicator of FEE was another influencing factor for adoption decision. Adopters give least priority Perceived Usefulness of Mobile Internet over Fixed Internet (USE). The research findings prove that subscribers are content with the level of the technicality in Mobile Internet connections whilst Mobile Internet connections are perceived to be more economical than Fixed Internet connections. Additionally, the results reveal that adoption decision is influenced by cultural and social characteristics of a particular society or a country. The clarity gained from this research can be considered by ISPs in their marketing activities.
ER to Relational Model Mapping: Information Preserved Generalized Approach
(International Postgraduate Research Conference 2019, Faculty of Graduate Studies, University of Kelaniya, Sri Lanka, 2019) Pieris, D.; Wijegunasekera, M.C.; Dias, N.G.J.
The Entity-Relationship (ER) model is widely used to create ER schemas to represent application domains in the Information Systems development field. However, when an ER schema is transformed to a Relational Database Schema (RDS), some critical information modeled on the ER schema may not be represented meaningfully on the RDS. This situation causes a loss of information during the transformation process. In our previous studies, we showed that the deficiencies that exist both in the ER model and the transformation algorithm cause this situation. Accordingly, we modified the ER model and the transformation algorithm to eliminate the deficiencies and thereby to preserve the information in the transformation process. We then showed that a mapping that is one-to-one and onto exists from the ER Schema to the RDS, and the information represented on the ER schema is preserved on the RDS. For this purpose, the ER schema should be created using the modified ER model and transformed to the RDS by the modified transformation algorithm. However, this concept has not yet been proved formally. It needs to be testified for any ER schema representing any application domain. Subsequently, following the modified ER model, we also proposed a generic ER schema ̶ an ER schema that represents any real-world phenomena in symbolic notation ̶ for using in a future proof creation process. Thus, in this work, we aim to create a formal proof for validating the work that we had done. For simplicity, we use a generic ER schema that consists of two regular (strong) entity types and a one-to-many-relationship-type. We first show that the generic ER schema can be partitioned into unique segments. We call them ER-construct-units, where each one represents a unique semantic meaning in the real world. The ER schema can be viewed to have been made up of the set of ER-construct-units. Both the ER schema and the ER-construct-unit set are equivalent. Second, we transform the generic ER schema to its corresponding RDS using the modified transformation algorithm. We then show that the RDS can also be partitioned into unique segments, which we call Relation-schema-units. Next, we show that a mapping that is one-to-one and onto exists from the set of ER-construct-units to the set of Relation-schema-units. In conclusion, we show that any ER-construct-unit in the ER schema has its own and unique Relation-schema-unit on the RDS. Therefore, any piece of information represented on the ER schema has its own and unique representation on the RDS. The proof can be expanded to any generic ER schema that is even bigger than the current one, and accordingly, the same result can be obtained. Since the generic ER schema means a generalized representation of any real-world ER schema, we conclude that information represented on any ER schema is preserved on its corresponding RDS.
An Improved Generic ER Schema for Conceptual Modelling of Information Systems
(Proceedings of the Asia International Conference on Multidisciplinary Research 2019, Vol.-1, 2019) Pieris, D.; Wijegunasekera, M.C.; Dias, N.G.J.
The Entity Relationship (ER) model is widely used for creating ER schemas for modelling application domains in the field of Information Systems development. However, when an ER schema is transformed to a Relational Database Schema (RDS), some important information on the ER schema may not be represented meaningfully on the RDS. This causes loss of information during the transformation process. Although, several previous researches have proposed solutions to remedy the situation, the problem still exists. Thus, in this on-going research we wish to improve the proposed solutions and maximize information preservation in the ER to relational transformation process. Cardinality ratio constraints, role names, composite attributes, and certain relationship types are among the information frequently lost in the transformation process. Deficiencies in the ER model and the transformation method seems causing this situation. We take the view that if the information lost is resolved; a one-to-one mapping should exist from the ER schema to its RDS. We modified the ER model and the transformation algorithm following a heuristic research method with a view to eliminating the deficiencies and thereby achieving a one-to-one mapping. We should show that the mapping exists for any real world application. We create a generic ER schema - an ER schema that represents any phenomena in symbolic form - and use it to show that a one-to-one mapping exists for any real world application. In this paper, we explore our generic ER schema and its advantages over its predecessors in view of representing any real world application.