Myung-Joon Lee

Extending VNC for effective collaboration

VNC (virtual network computing) is a remote access software using RFB (remote frame buffer) protocol. VNC supports access to resources of a remote system through sharing the desktop of the remote system. In this paper, we describe an extension of VNC for effective real-time collaboration through the Internet. For effective collaboration, we provide three kinds of access authorities: administrator, worker, and spectator. The administrator controls access authorities of the users. The workers can access the remote resources provided by the collaboration server, while the spectators can not handle the remote resources, only monitoring the remote desktop of the collaboration server. To support those access authorities, the UltraVNC server and the JavaViewer are extended.

Supporting Effective Collaborative Works Based on WebDAV

WebDAV is an IETF standard protocol which supports asynchronous collaborative authoring on the Web. The recently published WebDAV access control protocol provides various methods of controlling the resources on a WebDAV server and their properties, helping high-level collaborative works to be performed through the WebDAV server. Based on the WebDAV access control protocol, we developed a collaborative system named CoSlide which supports exchanging and/or sharing data among the members using the system. CoSlide provides Group workspaces - the shared spaces for the members in those groups as well as personal workspaces which are the private spaces on the Web for each user. In addition, it also provides open workspaces which support additional information exchanging methods for unsubscribed users. The CoSlide client has been developed as a windows application using .Net framework. The client also provides the ability to launch an authoring application from its WebDAV view, automatically locking, and downloading the content to be edited. We constructed the server for CoSlide using Jakarta Slide - a WebDAV server supporting the WebDAV access control protocol.

SMART: a CORBA-based mobile agent system supporting the OMG MAF specification

The Mobile Agent Facility (MAF) is a standard for a CORBA facility published by the Object Management Group (OMG). This standard provides interoperability between agent platforms from several vendors. We describe an appropriate implementation architecture to develop an MAF compliant mobile agent system, and present a mobile agent system named SMART; which satisfies the OMG MAF specification, written in Java. The SMART system supports interoperability with other mobile agent systems implemented according to the MAF specification, and also provides a security mechanism based on the security model recommended by the MAF specification. In addition, the SMART system introduces a distinguished resource access policy based on the access level of an agent which is classified as several abstract entities such as admin, user, and gypsy.

CoWare: a Web-based groupware for effective collaboration

Since most CSCW (Computer-Supported Cooperative Work) systems have been developed for particular computing platforms, they are usable only within the specific organizations supporting those particular platforms. Recently, according to the rapid growth and continuing success of the World-Wide Web, which offers a globally accessible platform-independent infrastructure, many CSCW systems has been constructed and developed on the basis of the Web. As one of such CSCW systems. In this paper, we describe the design and implementation of the CoWare system. The CoWare system provides shared workspaces, which enable members of a work group easily share information for collaborative work through their Web browsers. The shared workspaces support information sharing and management between users, and also support event monitoring and synchronization between collaborative works. In addition, the CoWare system provides channel management facilities for registering and searching electronic documents and messaging facility for synchronous and/or asynchronous communication.

SCondi: A Smart Context Distribution Framework Based on a Messaging Service for the Internet of Things

When developing IoT (Internet of Things) applications, context distribution is a key feature to support effective delivery of related contextual data obtained from things to all interested entities. With the advent of the IoT era, multiple billion devices can generate huge amounts of data that might be used in IoT applications. In this paper, we present a context distribution framework named SCondi utilizing the messaging service which supports MQTT—an OASIS standard IoT messaging protocol. SCondi provides the notion of context channel as a core feature to support efficient and reliable mechanism for distributing huge context information in the IoT environment. The context channel provides a pluggable filter mechanism that supports effective extraction, tailoring, authentication, and security of information.

CoPortlet: A WebDAV-based collaborative portlet supporting individualized services

The support systems for collaborations and communications through the Internet are frequently required. In addition, since the individualized service has been accepted as a productive and efficient way to work through the Internet, it is desirable for those support systems to be included as a component of the individualized service. In this paper, we describe the development of CoPortlet for the CoSlide collaborative system. CoPortlet is a portlet which provides various methods to control the resources of each workspace on the CoSlide server. As a component of a portal, CoPortlet supports effective collaboration for the portal users. Users can collaborate through CoPortlet included in each userpsilas own interfaces composed by various portlets for his or her daily working environment.

Jabber Messenger for a WebDAV-based Collaborative System

Jakarta Slide is a WebDAV server developed as one of Apache projects, which supports asynchronous authoring for various contents on the server. Unfortunately, since the WebDAV protocol does not explicitly provide the workspaces for user groups, it is difficult to support complicated collaboration using Jakarta Slide. The CoSlide system is an extension of Jakarta Slide to address this problem, presenting more effective collaborative environment by providing various workspaces for group collaboration. In this paper, we describe the CoJBother Messenger for the CoSlide collaborative system. We developed CoJBother by extending the JBother messenger based on the standard Jabber protocol. To support the users and groups defined on the CoSlide system, we also extended the Jabber protocol. CoJBother shows the information on the CoSlide users and groups in addition to the standard Jabber users and groups. In particular, through CoJBother, the members of a group on CoSlide can initiate group chatting without any administrative overhead.

Extending the Jabber protocol for a WebDAV-based Collaborative System

The CoSlide system is a WebDAV-based collaborative system developed as an extension of Jakarta Slide, providing effective asynchronous collaboration using remote resources and various workspaces for group collaboration. Since CoSlide presents only asynchronous collaborative environment, it is desirable to support synchronous communication tools for more effective collaboration. In this paper, we describe an extension of the Jabber protocol, which is an open, XML-based protocol for real-time, extensible instant messaging. We extended the standard Jabber protocol to support the users and groups defined in the CoSlide system. Also, according to the developed protocol, we extended the Jabberd server.

SlideAdmin: An Administration Tool for Jakarta Slide

Jakarta slide is an open-source content management system from the Jakarta project, which supports the WebDAV protocol and the WebDAV ACL protocol. To access the resources managed by slide, users should be registered to Slide with appropriate access privileges. Unfortunately, as of now, it is very cumbersome and time-consuming to add users to slide, setting up access privileges on the resources for them. So, to support efficient administration of the slide system, it is desirable to provide administration tools which can simplify those administrative activities. As one of such tools, we developed an administration tool for the slide system named SlideAdmin. Using SlideAdmin, the system administrator can add or delete users and roles more efficiently. SlideAdmin is composed of JSP pages for the user interface and Java Servlets performing the related administrative logic.

An Apache-based WebDAV Server Supporting Reliable Reliable Resource Management

WebDAV is a protocol to support collaboration among the workers in geographically distant locations through the Internet. WebDAV extends the web communication protocol HTTP/1.1 to provide a standard infrastructure for supporting asynchronous collaboration for various contents across the Internet. To provide the WebDAV functionality in legacy applications such as web-based collaborative systems or document management systems, those systems need to be implemented additionally to handle the WebDAV methods and headers information. In this paper, we developed an Apache-based WebDAV server, named DAVinci(WebDAV Is New Collaborative web-authoring Innovation)which supports the WebDAV specification. DAVinci was implemented as a form of service provider on a mod_dav Apache module. Mod_day, which is an Apache module, is an open source module to provide WebDAV capabilities in an Apache web server. We used a file system for storing resources and the PostgreSQL database for their properties. In addition, the system provides a consistency manager to guarantee that both resources and properties are maintained without inconsistency between resources and their properties.