A Concurrency Control Method Based on Commitment Ordering in Mobile Databases

Disconnection of mobile clients from server, in an unclear time and for an unknown duration, due to mobility of mobile clients, is the most important challenges for concurrency control in mobile database with client-server model. Applying pessimistic common classic methods of concurrency control (like 2pl) in mobile database leads to long duration blocking and increasing waiting time of transactions. Because of high rate of aborting transactions, optimistic methods aren`t appropriate in mobile database. In this article, OPCOT concurrency control algorithm is introduced based on optimistic concurrency control method. Reducing communications between mobile client and server, decreasing blocking rate and deadlock of transactions, and increasing concurrency degree are the most important motivation of using optimistic method as the basis method of OPCOT algorithm. To reduce abortion rate of transactions, in execution time of transactions` operators a timestamp is assigned to them. In other to checking commitment ordering property of scheduler, the assigned timestamp is used in server on time of commitment. In this article, serializability of OPCOT algorithm scheduler has been proved by using serializability graph. Results of evaluating simulation show that OPCOT algorithm decreases abortion rate and waiting time of transactions in compare to 2pl and optimistic algorithms.Comment: 15 pages, 13 figures, Journal: International Journal of Database Management Systems (IJDMS

The Big Match - Lexis v Westlaw

Lexis and Westlaw are the biggest names in subscription legal database provision. The author provides a comparative critical examination from his experience is of academic subscriptions to the services - including their American academic contentPreprint of an article by Paul Norman, former Reference and Online Services Librarian at the Institute of Advanced Legal Studies, published in Legal Information Management, the journal of the British and Irish Association of Law Librarian

Bibliometric Analysis: Developments in Research on Human Resource Management in Higher Education Based on the Google Scholar Database

This research aims to analyze the development of research on human resource management in higher education based on the Google Scholar database. It can provide a reference point for further research on related topics. This research method uses bibliometric analysis; data collection is carried out based on international publication data from the Google Scholar database from 2015-2022 using the Publish or Perish tool, and the data analysis process is carried out using the VOSviewer tool. The research results show that the distribution of journal articles on human resource management related to higher education in the Google Scholar database from 2015-2022 is 999 journals, and the development of journal publications in the Google Scholar database has decreased. This occurred in 2015 as the highest number of journal publications, namely 222 (22%), while the fewest journal publications occurred in 2022, namely 19 publications (2%). Through density visualization, the terms "Human Resource Management" and "University" are the most frequently used research topics. With the overlay visualization, "Human Resource Management" was mainly used as a research topic around 2017, while the term University was used as a research topic around 2018. Based on this, further research on human resource management can be developed by referring to others that still need to be done

An Understanding of the Application of Research Methods in Engineering Management

In this article, the use of research methods in the field of Engineering Management is analyzed. For this study, a database was formed by using articles from three journals in the Engineering Management field: the Engineering Management Journal (EMJ), the IEEE Transactions on Engineering Management and the Journal of Engineering and Technology Management (JETM). Articles written between 1999 and 2003 were analyzed and an Engineering Management research position map was developed to describe holistically the research methods being used in Engineering Management. No judgment on the Engineering Management field per se was undertaken as a result of this study. Instead, its findings are presented as groundwork for future investigations on effective methods to execute Engineering Management research