We propose to detect users navigationpaths to the advantage of web-site owners. First, we explain the design and implementationof a profiler which captures client’s selected links and pages order, accurate page viewing time and cache references, using a Java based remote agent. The information captured by the profiler is then utilized by a knowledge discovery technique to cluster users with similar interests. We introduce a novel path clustering method based on the similarity of the history of user navigation. This approach is capable of capturing the interests of the user which could persist through several subsequent hypertext link selections. Finally, we evaluate our path clustering technique via a simulation study on a sample WWW-site. We show that depending on the level of inserted noise, we can recover the correct clusters by %10-%27 of average error margin. 1.

In recent past, Java has emerged as a powerful and an easy to use language for net-centric computing. Simplicity, object oriented features, a presence of threads and architecture independence are main reasons for the popularity of Java. Despite of the built-in threads in the language, the bare Java execution model does not support remote object invocations. RMI (Remote Method Invocation) is an interface specified by Sun Microsystems for the purpose of native Java-client and Java-server communication. Although, RMI is simple to use, it is not desirable in many applications due to its synchronous nature. In this paper, we describe ARMI (Asynchronous RMI), a mechanism which is built on top of RMI and allows concurrent execution of local and remote computations. This article presents the salient features and implementational details of ARMI. A few experiments performed with ARMI along with performance comparisons to RMI are also explained. Keywords: RMI, RPC, Asynchronous, ARMI, Client, Server, Stub, Skeleton, Mailbox. 1

The Web Interface for Telescience (WITS) is an Internet-based tool that the Mars Pathfinder mission used for both mission operations at JPL and public outreach. WITS enables the viewing of downlinked images and results in various ways, terrain feature measurement and annotation, and planning of daily mission activities. WITS is written in the Java language and is accessible by mission scientists and the general public via a web browser. The public-can use WITS to plan and simulate their own rover missions. WITS will also be used in the 1998 lander and 2001, 2003, and 2005 rover missions to Mars. 1

The recent development of telecommunication networks has contributed to the success of applications such as information retrieval and electronic commerce, as well as all the services that take advantage of communication in distributed systems. In this area, the emerging technology of mobile agents aroused considerable interest. Mobile agents are applications that can move through the network for carrying out a given task on behalf of the user. In this work we present a platform (called MAP (Mobile Agents Platform)) for the development and the management of mobile agents. The language used both for developing the platform and for carrying out the agents is Java. The platform gives the user all the basic tools needed for creating some applications based on the use of agents. It enables us to create, run, suspend, resume, deactivate, reactivate local agents, to stop their execution, to make them communicate each other and migrate. Keywords: mobile agents, distributed computing, Java, net...

: The purpose of this report is to analyze the potential impact of distributed object technology (DOT) on software engineering practice. The analysis culminates with the conclusion that the technology will have a significant influence on both the design and reengineering of information systems and the processes used to build them. We see a profound impact and fundamental change in both technical thinking and practice as a result of the related technologies we group together as DOT. 1 Introduction Distributed object technology (DOT) is defined quite broadly for the purposes of this report. We consider it to include three technologies that have synergistically merged to provide something quite powerful---something greater than the sum of their parts.Those three technologies, in order of their emergence, are . object technology . distribution technology . Web technology Object technology (OT) was introduced to the computing mainstream in the late 1970s by Adele Goldberg and Alan Kay w...

this paper we will show how it is possible to use this technology to create a network computing platform for the management of applications distributed over a network. We will define and implement mechanisms for the execution of applications on any server, wherever the code of interest is physically located. In turn, these applications can request the execution of new processes, whose code does not necessarily have to be present locally but can be retrieved from remote servers. The approach proposed is highly flexible, not least because, assuming all the network nodes to be capable of executing the Java code, an application code can be executed on any of them, without any limit due to the presence of different hardware platforms.

This paper presents the results of a characterization analysis performed on the Java Virtual Machine (JVM) using the SPECÔÔ JVM98 benchmarks. We have developed an instrument that runs inside the JVM that provides profiles of a variety of different workload characteristics. The data from these profiles are examined to better understand where performance bottlenecks exist in the JVM and what optimizations are possible. The frequency data presented is a first step in determining what instructions require special attention. The stack level information describes the number of registers needed to store stack elements. This knowledge can then be applied to the development of specialized hardware architectures or enhanced interpreters. 1. Introduction The Java Virtual Machine language has become a success with the popularity and increased number of users on the Internet. Java allows programs to be used across a wide range of machine platforms, providing a common language interface. The Java b...

Distributed object technology is profoundly changing the ways in which software systems evolve over time. To a large extent, the focus of reengineering has been to understand legacy systems and to extract their essential functionality so that they can be rewritten as more robust and more maintainable systems over the long term. However, object technology, wrapping strategies, and the Web may be changing the focus and economics of reengineering. The question posed by this paper is the extent to which reengineering strategies ought to continue to use program understanding technology. The cost/benefit ratio of certain forms of program understanding appears to be staying roughly the same over time, while the cost/benefit ratio of wrapping legacy systems or their subsystems is dropping rapidly. As a result, new reengineering strategies that place less emphasis on deep program understanding, and more emphasis on distributed object technologies, should now be considered.

The World Wide Web (WWW) has been expanding exponentially since it was launched. It provides a unifying way to navigate and present information around the world in seconds using the Internet computer network. Many types of organization have been caught up in the revolution and are struggling to cope with the effects and keep pace with the development of the technology. One such community is that of museums. This paper presents the way museums are currently using the Web internationally, and how their use could develop in the future. Included is a description of the Virtual Library museums pages (VLmp), a leading directory of on-line museums, recently adopted by the International Council of Museums. Some of the `virtual' visitor statistics are also presented and discussed.

this article.