Most common database management systems represent information in a simple record-based format. Semantic modeling provides richer data structuring capabilities for database applications. In particular, research in this area has articulated a number of constructs that provide mechanisms for representing structurally complex interrelations among data typically arising in commercial applications. In general terms, semantic modeling complements work on knowledge representation (in artificial intelligence) and on the new generation of database models based on the object-oriented paradigm of programming languages.This paper presents an in-depth discussion of semantic data modeling. It reviews the philosophical motivations of semantic models, including the need for high-level modeling abstractions and the reduction of semantic overloading of data type constructors. It then provides a tutorial introduction to the primary components of semantic models, which are the explicit representation of objects, attributes of and relationships among objects, type constructors for building complex types, ISA relationships, and derived schema components. Next, a survey of the prominent semantic models in the literature is presented. Further, since a broad area of research has developed around semantic modeling, a number of related topics based on these models are discussed, including data languages, graphical interfaces, theoretical investigations, and physical implementation strategies.

Semantic database modeling: survey, applications, and research issues

A new class of models, formalisms and mechanisms has recently evolved for describing concurrent and distributed computations based on the concept of ``coordination''''. The purpose of a coordination model and associated language is to provide a means of integrating a number of possibly heterogeneous components together, by interfacing with each component in such a way that the collective set forms a single application that can execute on and take advantage of parallel and distributed systems. In this chapter we initially define and present in sufficient detail the fundamental concepts of what constitutes a coordination model or language. We then go on to classify these models and languages as either ``data-driven'''' or ``control-driven'''' (also called ``process-'''' or ``task-oriented''''). Next, the main existing coordination models and languages are described in sufficient detail to let the reader appreciate their features and put them into perspective with respect to each other. The chapter ends with a discussion comparing the various models and some conclusions.

/pdf/coordination-models-and-languages-4p4lzj3oar.pdf

Coordination models and languages

Robots are becoming an integral component of our society and have great potential in being utilized as an educational technology. To promote a deeper understanding of the area, we present a review of the field of robots in education. Several prior ventures in the area are discussed (post-2000) with the help of classification criteria. The dissecting criteria include domain of the learning activity, location of the activity, the role of the robot, types of robots and types of robotic behaviour. Our overview shows that robots are primarily used to provide language, science or technology education and that a robot can take on the role of a tutor, tool or peer in the learning activity. We also present open questions and challenges in the field that emerged from the overview. The results from our overview are of interest to not only researchers in the field of human–robot interaction but also administration in educational institutes who wish to understand the wider implications of adopting robots in education.

/pdf/a-review-of-the-applicability-of-robots-in-education-4r036zcnz1.pdf

A review of the applicability of robots in education

Three decades of active research on the teaching of introductory programming has had limited effect on classroom practice. Although relevant research exists across several disciplines including education and cognitive science, disciplinary differences have made this material inaccessible to many computing educators. Furthermore, computer science instructors have not had access to a comprehensive survey of research in this area. This paper collects and classifies this literature, identifies important work and mediates it to computing educators and professional bodies.We identify research that gives well-supported advice to computing academics teaching introductory programming. Limitations and areas of incomplete coverage of existing research efforts are also identified. The analysis applies publication and research quality metrics developed by a previous ITiCSE working group [74].

A survey of literature on the teaching of introductory programming

A distributed STREAMS process operates on a multicomputer system composed of a cluster of nodes of one or more processors running an operating system having a file system and a STREAMS message-passing mechanism implementing network protocols, client-server applications, and STREAMS-based pipes. A local node has a software application operative under the operating system. The distributed STREAMS process determines that it is operating within a cluster and transparently intercepts application open requests which are sent to a controlling thread (CT) created during node initialization. The CT determines whether the open is to occur on the local or a remote node and whether any cluster facility should be activated by examining major and minor numbers encoded within the file structure being opened. If the CT determines a local open is to occur, it performs a local open, as normal, and activates the indicated cluster facilities. If the CT determines a remote open is to occur, it uses the STREAMS mechanism to establish a connection to the remote node via a STREAMS software interconnect driver (S-ICS) operating on both nodes. The local node's CT then communicates the open request to the remote node's CT which performs an internal STREAMS open to create data structures and infrastructure to ensure proper communication and error recovery. If a failure occurs, the CT and S-ICS detect this failure and transparently initiate error recovery by migrating failed components, if possible, to new node(s) within the cluster. This migration capability can also be used to provide load balancing within the cluster of distributed STREAMS.

Creation and migration of distributed streams in clusters of networked computers

ISIS IS an experimental system for graphically manlpulatmg a database The system 1s based on a simply specified high-level semantic data model It demonstrates the capablbtles of a workstation environment by mtegratmg three aspects of database programming m one graphical setting Namely, it permits database constructlon and modification, it allows browsing at the schema and data levels, and provides a graphical query language In all of these activities it maintains uniform graphlcal representations and consistent user mteractlon techniques

/pdf/isis-interface-for-a-semantic-information-system-3ohi0puf1y.pdf

ISIS: interface for a semantic information system

1. SUMMARY In the past decade educators have developed a myriad of tools to help novices learn to program. Different tools emerge as new features or combinations of features are employed. In this panel we consider the features of recent tools that have garnered significant interest in the computer science education community. These including narrative tools which support programming to tell a story (e.g., Alice [6], Jeroo [8]), visual programming tools which support the construction of programs through a drag-and-drop interface (e.g., JPie [3], Alice [6], Karel Universe), flow-model tools (e.g., Raptor [1], Iconic Programmer [2], VisualLogic) which construct programs through connecting program elements to represent order of computation, specialized output realizations (e.g., Lego Mindstorms [5], JES [7]) that provide execution feedback in nontextual ways, like multimedia or kinesthetic robotics, and tiered language tools (e.g., ProfessorJ [4], RoboLab) in which novices can use more sophisticated versions of a language as their expertise develops.

https://dsys.cse.wustl.edu/resources/papers/gross-sigcse-2006.pdf

Tools for teaching introductory programming: what works?

A system for software development provides an underlying object-oriented programming language and a language front-end supporting software development in a programming methodology of the object-oriented programming language, the system providing a graphical programming environment permitting access to classes of the object-oriented programming language and permitting subclasses to be defined and modified dynamically (“dynamic classes”) while the software under development is executing. Modifications to the dynamic classes can be reflected in future instances of the classes and in instances of the classes existing prior to the changes. In one embodiment, the object-oriented programming language is Java. The dynamic classes coexist with compiled classes of the object-oriented programming language, the dynamic and compiled classes each being capable of calling methods on instances of any class. The dynamic classes may be created as subclasses of other dynamic classes or of compiled classes (“parent classes”) and may selectively override methods of the parent class.

Live software construction with dynamic classes

I/O abstraction is offered as a new high-level approach to interprocess communication. Functional components of a distributed system are written as encapsulated modules that act upon local data structures, some of which may be published for external use. Relationships among modules are specified by logical connections among their published data structures. Whenever a module updates published data, I/O takes place implicitly according to the configuration of logical connections. The Programmers' Playground, a software library and runtime system supporting I/O abstraction, is described. Design goals include the separation of communication from computation, dynamic reconfiguration of the communication structure, and the uniform treatment of discrete and continuous data types. Support for end-user configuration of distributed multimedia applications is the motivation for the work. >

The Programmers' Playground: I/O abstraction for user-configurable distributed applications

Given a positive integer k and a complete graph with non-negative edge weights satisfying the triangle inequality, the remote-clique problem is to find a subset of k vertices having a maximum-weight induced subgraph. A greedy algorithm for the problem has been shown to have an approximation ratio of 4, but this analysis was not shown to be tight. In this paper, we use the technique of factor-revealing linear programs to show that the greedy algorithm actually achieves an approximation ratio of 2, which is tight.

/pdf/an-improved-analysis-for-a-greedy-remote-clique-algorithm-2reive4z7j.pdf

Kenneth Goldman

Papers

ISIS: interface for a semantic information system

Tools for teaching introductory programming: what works?

Live software construction with dynamic classes

The Programmers' Playground: I/O abstraction for user-configurable distributed applications

An Improved Analysis for a Greedy Remote-Clique Algorithm Using Factor-Revealing LPs