岡本 秀輔

This paper describes an implementation of a runtime environment for portable message-passing C programs with Message Passing Interface (MPI) library on web browsers. We have implemented core functions of the library. The runtime system runs several MPI programs without any modification. We confirm that the runtime performances of the programs are comparable to their native executions on some conditions.

This paper describes a C++ library to build web applications. The idea is borrowed from Node.js and Express. js which are a rapid web development framework for JavaScript. Our library consists of a few header files so that it can be available by including them into a source code. The API uses some C++ 14 features, especially 'auto' type, and the program which uses this library becomes concise and clear. In this paper, the design policy, several sample programs and its implementation are presented.

In an university, students take an oral exam to check the understanding level. Especially, in a programming class, a student writes a program source code to solve a practice. Then, the student takes an oral exam. To support the ordering of the oral exam and the checking source code, this paper proposes a reservation system for oral exam. A student uploads source code files to the system. Then, the student is registered to a queue of the oral exam. The student can check the own turn because the own student ID is highlighted. A teacher checks the source code files and asks some questions to the student. Finally, the teacher grades the student and registers the grade to the system.

In this paper, we propose a location registration scheme using location-based Social Networking Services. Our system provides schedules of a teacher on a Web page. The schedule includes the classes, the meetings, and the official trips. However, the teacher might not have any time to register schedules or forget to register the schedule. Therefore, we need a scheme to register the schedule easily. One of approaches is the location registration. If a student knows a location of the teacher, the student knows whether the teacher is in the room or not. Our system register the location information by collaborating with location-based SNSs.

This paper describes a method for rapidly authoring multiplayer online games. The game author specifies state machines that define the behavior of game characters. The results are translated into a JavaScript code. The entire application is supported by Node.js at the server side and by modern Web browsers at the client side. Utilization of the WebSocket feature allows the communication between the Web browsers and the web server to be processed efficiently, and the player's interaction with the game interface is smooth. © 2013 ACM.

This paper describes a web mining method for clustering research documents automatically. Web hit counts of AND-search for two words are used to form a document feature vector. Target documents are clustered using the k-means clustering method twice, in which cosine similarity is used to calculate the distance measure. © 2013 Inderscience Enterprises Ltd.

The web-based-application user base has witnessed rapid growth. It has become necessary to develop techniques that enable systems to manage simultaneous access by a large number of users. We focus on web-based MultiPlayer Online Role-Playing Games (MORPGs), which must be able to cope with a large number of users and a high frequency of user requests. In our previous work, we introduced a system using multiple web servers and a dynamic data allocation method, which is able to manage dynamic change in user requests. Using this method, we achieved a capacity of 320 users, as opposed to the user capacity of 200 for single-server MORPG system. However, we found some cases in which our method was not effective. In this paper, we propose three rules for dynamic data allocation to address different situations. Our evaluation shows that the cache works effectively if the most avatars gather in a certain place. Copyright © 2012 Inderscience Enterprises Ltd.

Purpose: The purpose of this paper is to propose a load distribution technique for a web server. It utilizes Web Workers, which is a new feature of Javascript. Design/methodology/approach: The authors have been implementing a web-based MORPG as an interactive, real-time web application previously, the web server alone was responsible for manipulating the behavior of all the game characters. As more users logged in, the workload on the server was increased. Hence, the authors have implemented a technique whereby the CPU load of the server is distributed among the clients. Findings: The authors found that some caching mechanism is useful for utilizing client-side calculation. The caching suppresses the increase of communication load. A performance evaluation reveals that the technique plays a role in decreasing the CGI latency of both low-end server and high-end server. The average latency is reduced to 59.5 percent of the original system. Originality/value: Web Workers allows scripts to be executed with keeping the page response on a web browser. It is intended to be used for raising user experience. This technique utilizes Web Workers for a web server to distribute the load to its clients. © Emerald Group Publishing Limited.

This letter proposes a prototyping tool for Web-based Multiuser Online Role-Playing Game (MORPG). The design goal is to make this tool simple and powerful. The tool is comprised of a GUI editor, a translator and a runtime environment. The GUI editor is used to edit state-transition diagrams, each of which defines the behavior of the fictional characters. The state-transition diagrams are translated into C program codes, which plays the role of a game engine in RPG system. The runtime environment includes PHP, JavaScript with Ajax and HTML. So the prototype system can be played on the usual Web browser, such as Firefox, Safari and IE. On a click or key press by a player, the Web browser sends it to the Web server to reflect its consequence on the screens which other players are looking at. Prospected users of this tool include programming novices and schoolchildren. The knowledge or skill of any specific programming languages is not required to create state-transition diagrams. Its structure is not only suitable for the definition of a character behavior but also intuitive to help novices understand. Therefore, the users can easily create Web-based MORPG system with the tool.