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A bi-level programming approach has been used to tackle an area traffic control optimisation problem subject to user equilibrium traffic flows. In the upper level problem, the signal timing plan for coordinated fixed time control has been defined. In the lower level problem, user equilibrium traffic assignment obeying Wardrop's first principle has been formulated as a variational inequality problem. Mathematical expressions for various components of the performance index in the upper level problem and the average delay in the lower level problem have been derived and reported (Chiou 1997a). A mixed search procedure has been proposed as the solution method to the bi-level problem and a range of numerical tests have been carried out (Chiou 1997b, 1998a,b). In this paper, further numerical tests are performed on Allsop and Charlesworth's (1977) road network in which various traffic loads are taken into account. Effectiveness in terms of the robustness and reliability of the mixed search procedure in congested and uncongested road networks is thus investigated further. Comparisons of the performance index resulting from the mixed search procedure and that of mutually consistent TRANSYT-optimal signal settings and traffic flows are made for the congested road network.

The purpose of this paper is to apply social network analysis (SNA) to study faculty research productivity, to identify key leaders, to study publication keywords and research areas and to visualize international collaboration patterns and analyze collaboration research fields from all Management Information System (MIS) departments in Taiwan from 1982 to 2015.

The authors first retrieved results encompassing about 1,766 MIS professors and their publication records between 1982 and 2015 from the Ministry of Science and Technology of Taiwan (MOST) website. Next, the authors merged these publication records with the records obtained from the Web of Science, Google Scholar, IEEE Xplore, ScienceDirect, Airiti Library and Springer Link databases. The authors further applied six network centrality equations, leadership index, exponential weighted moving average (EWMA), contribution value and k-means clustering algorithms to analyze the collaboration patterns, research productivity and publication patterns. Finally, the authors applied D3.js to visualize the faculty members' international collaborations from all MIS departments in Taiwan.

The authors have first identified important scholars or leaders in the network. The authors also see that most MIS scholars in Taiwan tend to publish their papers in the journals such as Decision Support Systems and Information and Management. The authors have further figured out the significant scholars who have actively collaborated with academics in other countries. Furthermore, the authors have recognized the universities that have frequent collaboration with other international universities. The United States, China, Canada and the United Kingdom are the countries that have the highest numbers of collaborations with Taiwanese academics. Lastly, the keywords model, system and algorithm were the most common terms used in recent years.

This study applied SNA to visualize international research collaboration patterns and has revealed some salient characteristics of international cooperation trends and patterns, leadership networks and influences and research productivity for faculty in Information Management departments in Taiwan from 1982 to 2015. In addition, the authors have discovered the most common keywords used in recent years.