Masaki Kohana

Dynamic Data Allocation Scheme for Multi-server Web-Based MORPG System

Recently, due to the spread of broadband access to the Internet, the speeding up JavaScript on Web browsers and the development of communication technology such as Ajax, a variety of Web applications are provided. However, the access congestion to the Web server and the lower usability in case of higher frequent communication are major problems on the Web application. We have investigated the bottleneck in Web-based MORPG system and proposed the load-distribution technique using multiple Web servers[8]. This technique uses a dynamic allocation of the data, called the moving home. We proposed some rules for the moving home[9]. In this paper, we applied these rules to our MORPG system and evaluated them.

Dynamic reallocation rules on multi-server web-based MORPG system

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.

Improving bottleneck in Web-based MORPG

The recent spread of broadband Internet access, speeding up of JavaScript in Web browsers, and development of communications technology such as Ajax has led to the development of a variety of Web applications. The access congestion of Web servers and lower usability in the case of frequent requests are the major problems that affect the use of Web applications. In this study, we investigate the bottlenecks in single-server system and propose a technique to improve the usability of Web-based MORPG servers.

Load distribution by using web workers for a real-time web application

In this paper, we describe a load distribution technique that employs web workers. We 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, we have implemented a technique whereby the CPU load of the server is distributed among the clients; a performance evaluation reveals that our technique plays a role in decreasing the CGI latency of low-end servers and can decrease the CPU load of high-end servers when many users are logged in.

Reallocation Criteria on Multi-server Web-based MORPG System

In recent times, the web-based applications has grown rapidly and there has been an explosive increase in the number of users. Hence, it is necessary to develop technique to deal with several users. In this study, we particularly focus on web-based multiplayer online role-playing games (MORPGs), which have a large number of users and deal with high frequency of user requests. In our previous work, we introduced a method to deal with a large number of users using multiple web servers and a dynamic data allocation method to deal with dynamic change in the user request. Using our method, we achieved a user capacity of 320 for the web-based MORPG system as opposed to 200 user capacity of the single server MORPG system. However, we found some cases in which our dynamic data allocation role was not effective. In this paper, we propose three rules for our dynamic data allocation method to address various situations. We evaluate these rules using four web servers and investigate their properties and effectiveness.

Document classification based on web search hit counts

This paper describes a web mining method to classify research documents automatically. Web hit counts of AND-search on two words are used to form a document vector. Target documents are classified with a result of k-means clustering method, in which cosine similarity is used to calculate a distance.

Optimal Data Allocation for Keeping Fairness of Online Game

In our previous work, we proposed a load distribution technique and dynamic data reallocation method for web-based MORPG system. This approach could reduce the average server latency for game players. However, each latency widely varied, which leads unfair situation for game players. In this paper, we deal with data allocation with taking into account the fairness as a combinational optimization problem. We develop an optimization model whose objective function is to minimize the difference among latency value. We exactly solve this problem and compare the results with our previous data allocation method.

Load distribution by using Web Workers for a real‐time web application

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 ...

Sphero Control System Using a Web Browser

This paper proposes a remote control system of Sphero using a web browser. Sphero is a robotics ball that is controlled by using a smartphone. A user can control Sphero using Android or iOS application. However, the user is supposed to be with the Sphero. We provides a remote control system as a web application. The user can control Sphero using a web browser. The Sphero connects to a smartphone and the smartphone connects to the web server. The smartphone is a relay station. The user sends operation commands to the web server using the web browser. The smartphone receives the commands from the web server and forwards it to the Sphero. The smartphone also sends camera images to the web server. The web browser receives the image from the web server and displays it. This means that the user can observe the state of the Sphero and control Sphero at a different place from a place that the Sphero exists. We confirm the behavior of our system and clarify some problems.

Optimal data allocation and fairness for online games

In our previous work, we proposed a load distribution technique and a dynamic data reallocation method for web-based Multiplayer Online Role-Playing Game MORPG systems. Our proposed approach reduced the average server latency for game players. However, latency values varied widely resulting in some game players gaining an advantage over others. In this paper, we deal with data allocation and consider latency fairness in the form of a combinational optimisation problem. We develop an optimisation model in which the objective function minimises the differences in latency values and we solve instances from this model using an exact algorithm. Our model improved latency fairness and more stable server loads than the previous data reallocation method. Furthermore, it provides more stable gameplay using ten web servers instead of five.