Ariel J. Frank

Multicast Communication on Network Computers

Channel-oriented packet casting is a predominant feature of Micros, an operating system designed to explore control and communication techniques for network computers containing thousands of hosts.

CarCoach: a generalized layered architecture for educational car systems

Car accidents are a major concern. Consequently, a lot of research is carried out on car user interfaces. For each such research, usually a special simulator or car is developed, algorithms and tools are redeveloped, and similar issues arise. We propose CarCoach, an educational car system, based on a generalized layered architecture. We present the system design, the intelligent modular architecture, its layers, including details of some of its relevant modules. Using the Chrysler 300M IT-Edition car as a platform, a prototype was implemented and initial experimentation was carried out and is reported. We demonstrate that CarCoach provides a flexible environment for car research and support of varied car applications.

The parallel evolution of search engines and digital libraries: their convergence to the Mega-Portal

There are many and varied search engines (SEs) on the Internet but it is still hard to locate and concentrate only on materials relevant to a specific task. Digital libraries (DLs) could better provide such services on the Web. There is a real need to formulate a methodology for the understanding of both these types of Web data repositories. We classify both SEs and DLs using similar criteria on both a functional scale and a generational time-line. In particular, we introduce the idea of the third generation Harvested DL and its resulting DL harvesting model. By comparing them and analyzing their characteristics, we discover that they actually share much in common. Finally, we note the expected incorporation of intelligent techniques and knowledge management in fourth generation SEs and DLs and the expected convergence of their interfaces and structures in the fifth generation - the Mega-Portal.

Enriching the E-learning Experience in the Framework of Web 2.0 Using Usability 2.0

The e-learning experience suffers from several known drawbacks; some resulting from the media in use, but some resulting from the unwise use of technology. The field that methodically deals with ways to utilize technologies and harness them for the users, in our case – the learners, is Human-Computer Interaction (HCI). The two major methods utilized are usability and user experiences. Web 2.0 has been creative with an approach that integrates these two methods – Usability 2.0 – distinguished from Usability 1.0 that is more oriented to usability. This work tries to understand how and in what way HCI methods can be used in order to enrich the e-learning experience. The research question investigated here is will the design of an e-learning environment in the framework of Web 2.0 (i.e., user content publishing and collaboration between users), via use of methodology and tools of Usability 2.0 (that integrates usability and user experiences) – enrich the e-learning experience itself. This work though only investigates the difference between the influences that Usability 2.0 has on the e-learning experience in comparison to Usability 1.0. The investigation was carried out on a student population from technological colleges in northern Israel. Quantitative tools were mainly used in this research while utilizing also qualitative tools. Quantitative outcomes confirmed that interface design using Usability 2.0 methods can enrich the e-learning experience. As was hypothesized, such an advanced interface enables an innovative flow experience and better perceived feeling of control of the learning process. In parallel, qualitative outcomes point to hardships encountered by the learners in their work with e-learning systems that were not designed using Usability 2.0.

Offline simulation of a managed system for testing a developed management system

Nowadays, there is a growing need for management systems to manage various autonomous systems. These management systems are difficult to test, since their functionality includes exchange of information with various devices and applications via the network communication. There is a need for efficient methods of development and testing to minimize development time and cost. The solution suggested is an offline simulation model, where the simulation and the tested management system are placed on the same computer. This model decouples the testing of the functional aspects of the developed management system from the testing of the communication aspects. This method saves a great deal of human effort, and therefore reduces development time and cost.

Harnessing search engine technology to raise awareness and availability of digital libraries

Searching for information on the Web is easy. Finding high quality information is hard. This partially stems from prevalent use of search engines (SEs) for information seeking tasks, when, for appropriate tasks, wise use of relevant digital libraries (DLs) could provide high quality information. However, the awareness and discovery of DLs on the Web is still lacking. The solution proposed herein is of the SELFDL (SE locator for DLs) model that is patterned after the popular Google style. Its task is to locate DLs, organize them in various knowledge structures, and provide a usable interface for locating relevant DLs. We describe the SELFDL framework that has three major components: directory, index and meta-search engine that are based on a common infrastructure. SELFDLs aim is to tilt the current balance of use between SEs and DLs in the direction of increased use of DLs, when that use is merited, hence increasing the qualitative use of the Web.

A C++/Linda model for distributed objects

Distributed systems have many advantages over centralized systems. The authors focus on the novel Linda Tuple Space (TS) model designed for generative coordination in a distributed shared memory model. Currently, the object-oriented programming (OOP) model is considered a most suitable model for handling complex computer-based systems. Among the OOP languages, the C++ language is a de-facto standard for developing advanced systems. The paper takes these two orthogonal computational models and combines them in a new way to form a C++/Linda model that supports transparent distributed objects. The idea is to create an integrated model that builds on the advantages of both models while complementing whatever is missing in each one alone. A prototype of the C++/Linda model was implemented and several distributed programs were successfully run on it.

A portable modula-2 operating system: SAM2S

The Stand-Alone Modula-2 System (SAM2S) is a portable, concurrent operating system and Modula-2 programming support environment. It is based on a highly modular kernel task running on single process-multiplexed microcomputers. SAM2S offers extensive network communication facilities. It provides the foundation for the locally resident portions of the MICROS distributed operating system for large netcomputers. SAM2S now supports a five-pass Modula-2 compiler, a task linker, link and load file decoders, a static symbolic debugger, a filer, and other utility tasks. SAM2S is currently running on each node of a network of DEC LSI-11/23 and Heurikon/Motorola 68000 workstations connected by an Ethernet. This paper reviews features of Modula-2 for operating system development and outlines the design of SAM2S with special emphasis on its modularity and communication flexibility. The two SAM2S implementations differ mainly in their peripheral drivers and in the large amount of memory available on the 68000 systems. Modula-2 has proved highly suitable for writing large, portable, concurrent and distributed operating systems.

User Empowering Design

Any progress and change in the world of Information Technologies (IT) impacts the lives of billions of people. Our work is part of a concerted effort of Human Centered Computing (HCC) to produce a shift in the world of IT from being focused on software to focusing on people who use the software.

On the Existence and Construction of Robust Communication Protocals for Unreliable Channels

A simple necessary and sufficient condition for the existence of robust communication protocols for arbitrary alphabets and a large class of transmission errors is presented. This class of errors, called transformation errors, consists of those errors where symbols (messages) may be lost or corrupted to other symbols. The proof is used as the basis of a procedure for automatically constructing robust protocols for transformation errors. The protocols generated are small in size, despite not being custom-designed. The results presented generalize and expand upon those of Aho et al. [AUY79]. Two protocols are constructed to illustrate our technique, and are contrasted with those of Aho et al.