This work introduces a new component software architecture - ThreadMill - whose main purpose is to facilitate the development of applications in domains where high volumes of streamed data need to be efficiently analyzed. It focuses particularly on applications that target the analysis of human communication e.g. in speech and gesture recognition. Applications in this domain usually employ costly signal processing techniques, but offer in many cases ample opportunities for concurrent execution in many different phases. ThreadMill's abstractions facilitate the development of applications that take advantage of this potential concurrency by hiding the complexity of parallel and distributed programming. As a result, ThreadMill applications can be made to run unchanged on a wide variety of execution environments, ranging from a single-processor machine to a cluster of multi-processor nodes. The architecture is illustrated by an implementation of a tracker for hands and face of American Sign Language signers that uses a parallel and concurrent version of the Joint Likelihood Filter method.

The Neem Platform is a research test bed for Project Neem, concerned with the development of socially and culturally aware collaborative systems in a wide range of domains. In this paper we discuss a novel use of perceptual interfaces, applied to group collaboration support. In Neem, the multimodal content of human to human interaction is analyzed and reasoned upon. Applications react to this implicit communication by dynamically adapting their behavior according to the perceived group context. In contrast, perceptual interfaces have been traditionally, employed to handle explicit (multimodal) commands from users, and are as a rule not concerned with the communication that takes place among humans. The Neem Platform is a generic (application neutral) component-based evolvable framework that provides functionality that facilitates building such perceptual collaborative applications.

The design and implementation of a workflow management system is typically a large and complex task. Decisions need to be made about the hardware and software platforms, the data structures, the algorithms, and network interconnection of various modules utilized by various users and administrators. These decisions are further complicated by requirements such as flexibility, robustness, modifiability, availability, performance, and usability. As the size of workflow systems increases, organizations are finding that the standard server/client architectures, and off-the-shelf solutions are not adequate. We can further see that in the farther future, very large-scale workflow systems (VLSW) will become more complex, and more prevalent. Thus, one further requirement is an emphasis of this document: scalability. For the purposes of our scalable workflow investigations, we describe a framework, a taxonomy, a model, and a methodology to investigate the performance of various workflow architectures as the size of the system (number of workcases) grows very large.First, this paper presents a novel workflow architectural framework and taxonomy. In fact, most current workflow architectures fall into only one of the many categories of this taxonomy: the centralized server/client category. The paper next explains a performance analysis methodology useful for exploring this taxonomy. The methodology deploys a layered queuing model, and performs mathematical analysis on this model using a modified MOL (method of layers) combined with a linearization algorithm. Finally, the paper utilizes this methodology to compare and contrast the various architectural categories, providing interesting results about performance as the number of workcases increases. Our analytic results suggest that (a) for VLSW performance determination, software architecture is as important as hardware architecture, and (b) alternatives to the client server architecture provide significantly better scalability.

The focus of traditional workflow management systems is on control flow within one process definition. The process definition describes how a single case (i.e. workflow instance) in isolation is handled. For many applications this paradigm is inadequate. Interaction between cases to support communication and collaboration is at least as important. This paper introduces and advocates the use of interacting proclets, i.e. lightweight workflow processes. By promoting interactions to first-class citizens it is possible to model complex workflows in a more natural manner. In addition, the expressive power and flexibility are improved compared to the more traditional workflow modeling languages.

Standard client-server workflow management systems have an intrinsic scalability limitation: the central server is a bottleneck for large scale applications. It is also a single fault paint that may disable the whole system. We propose a fully distributed architecture for workflow management systems. It is based on the idea that the case (an instance of the process) migrates from host to host, according to the process definition specification, as the corresponding activities are executed. This basic architecture is improved so that other requirements for Workflow Management Systems, besides scalability, are also contemplated. A CORBA-based implementation of such architecture is discussed, with both its limitations and positive points described.

Rd-time group editors dow a group of users to view and edit, the same document at the same time horn geograpbicdy di.~ersed sites connected by communication networks.Consistency maintenance is one of the most si@cant &alwiges in the design and implementation of thwe types of systems.R=earch on rd-time group editors in the past decade has invented au inuolative tetique for consistency maintenance, ded operational transformation This paper presents an integrative review of the evolution of operational tra=formation techniques, with the go~of identifying the major is-m~s, dgotiths, achievements, and remaining Mlenges.In addition, this paper contribut= a new optimized generic operational transformation control algorithm.

This paper introduces a mathematical model of groupware systems called Team Automata.We use this model at the architectural level, to describe components of a groupware system, and their interconnections.The multiple automata constituting the team interact via shared actions -transitions which multiple automata perform synchronously together.The paper concludes by illustrating the application of this model to the analysis of real time shared application groupware.The model suggests that there are design alternatives for shared .applicationgroupware which have mostly gone unexplored.

This paper discusses a conceptual model of groupware consisting of three complementary components or models: a description of the objects and operations on these objects available in the system; a description of the activities (and their orderings) that the users of the system can perform; and a description of the interface of users with the system, and with other users. KEYWORDS: Groupware, CSCW, collaboration technology, system modelling, ontological model, coordination model, user interface model. INTRODUCTION This paper is concerned with technology mediated workgroup systems, also sometimes called CSCW systems or groupware. We take the broad definition of these terms, as presented by Schmidt and Bannon [16]. We present a conceptual model which is applicable to a wide range of groupware---from electronic meeting rooms, through video conferencing, to workflow systems. The issues raised by the model are sometimes similar to, but frequently distinct from single user systems issues. T...

Cooperation is the organizational motivation behind computer networks. In these networks, information systems progress from their traditional file cabinet role to become advanced communications media that enable cooperation across boundaries of space and time. The Third ICIS Workshop, held at Dagstuhl Castle, Germany, in April 1992 addressed the question: what does this observation entail for computer science research, practice, and education? Research implications. Cooperation technology provides interfaces between people rather than between humans and machines. The simplistic distinctions of CSCW research in the 1980’s (synchronous vs. asynchronous, local vs. distributed, message passing vs. information sharing) detract from the central goal that coordination should not get in the way of human interaction. On the one hand, CSCW operates in a coherent organizational and technological framework. Real-time group interfaces must be embedded in process-oriented repositories for long-term cooperation; change management is the crucial research issue. On the other hand, CSCW must be enriched with domain information. Studies of the usage and organizational embedding of information technology cannot be delegated to the social sciences alone because they do not have the answers either. Business implications. “Killer applications” that prove the value of CSCW beyond electronic mail and videoconferencing have yet to emerge. One suggestion is to develop theory and product ideas in the context of actual applications through direct links between researchers and users. A more vendor-oriented approach focuses on developing core technology on which application-specific services can be delivered. This latter infrastructure market, though important, is obviously much smaller; it is the services that pay back the investments. Educational implications. Curricula do not adequately reflect the changing role of computer scientists in the workplace. This is even now endangering the traditionally good position of computer science graduates on the labor market. In accordance with the market shares above, there must be a stronger component of application experience and students must be explicitly taught to work in interdisciplinary teams. Since curricula are already very full, this implies that some traditional areas of computer science may have to be reduced — a painful but necessary process.

Groupware systems are computer-based systems that support two or more users engaged in a common task, and that provide an interface to a shared environment. These systems frequently require fine-granularity sharing of data and fast response times. This paper distinguishes real-time groupware systems from other multi-user systems and discusses their concurrency control requirements. An algorithm for concurrency control in real-time groupware systems is then presented. The advantages of this algorithm are its simplicity of use and its responsiveness: users can operate directly on the data without obtaining locks. The algorithm must know some semantics of the operations. However the algorithm's overall structure is independent of the semantic information, allowing the algorithm to be adapted to many situations. An example application of the algorithm to group text editing is given, along with a sketch of its proof of correctness in this particular case. We note that the behavior desired in many of these systems is non-serializable.

An experimental object base management system called Gordion is presented. Gordion is a server which provides permanence and sharing of objects for workstations within an object-oriented environment. Among the unique aspects of Gordion are: its ability to communicate with multiple languages, introduction of new concurrency control primitives, ability to manipulate objects of arbitrary size, and object sharing across the languages through a base set of classes. The system is currently interfaced to two languages, BiggerTalk and Zetalisp Flavors. Beside its language interface, Gordion has an interface for the system administrator, and an interface for debugging. Major functional components of the system are: concurrency control, storage, history and inquiry, and maintenance. Concurrent access to objects is regulated by four types of locks, and transactions encapsulate units of work for the system. The storage system uses a hashing scheme and Unix™ files to store objects. A discussion of the future prospects for Gordion concludes the paper.

The Software Technology Program of MCC is investigating the early part of the design process, before requirements are established, for large-scale distributed systems. Face-to-face meetings are an important activity during this phase of a project since they provide a medium for direction, exploration, and consensus building. Project Nick is attempting to apply automated facilities to the process, conduct, and semantic capture of design meetings. Primary topics covered in this paper are meeting analysis, meeting augmentation, and a model of meeting progression that serves as the framework for our work.

Article Project Nick: meetings augmentation and analysis Share on Authors: Michael Begeman MCC, Austin, Texas MCC, Austin, TexasView Profile , Peter Cook MCC, Austin, Texas MCC, Austin, TexasView Profile , Clarence Ellis MCC, Austin, Texas MCC, Austin, TexasView Profile , Mike Graf MCC, Austin, Texas MCC, Austin, TexasView Profile , Gail Rein MCC, Austin, Texas MCC, Austin, TexasView Profile , Tom Smith MCC, Austin, Texas MCC, Austin, TexasView Profile Authors Info & Claims CSCW '86: Proceedings of the 1986 ACM conference on Computer-supported cooperative workDecember 1986 Pages 1–6https://doi.org/10.1145/637069.637071Online:03 December 1986Publication History 28citation571DownloadsMetricsTotal Citations28Total Downloads571Last 12 Months8Last 6 weeks1 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteGet Access

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Solutions to the duplicate database update problem are considered, and a formal validation technique using the theory of L systems is developed and applied to the problem. The paper shows some particular solutions but is primarily concerned with general properties of the problem, convenient representational techniques, and formal proof procedures which are general enough to apply to this and to a number of other problems in parallel processing and synchronization.

This paper describes a practicum-seminar course which the author taught at the University of Colorado during the spring and summer of 1974. This course contained a number of salient features which made it an interesting experiment and a unique learning experience for all involved. The broad goals of the seminar were:

As the number of processes and resources increases within a computer system, does the probability of that system's being in deadlock increase or decrease? This paper introduces Probabilistic Automata as a model of computer systems. This allows investigation of the above question for various scheduling algorithms. A theorem is proven which indicates that, within the types of systems considered, the probability of deadlock increases.

A computer program which randomly generates strings of a language from a phrase structure grammar is considered.By developing a theory of probabilistic languages and probabilistic grammars, a necessary and sufficient condition for the program to stop with probability one is established.

The purpose of this paper is meant to be three-fold. First it will introduce the reader to the concepts of Probabilistic Languages and Probabilistic Grammars. Second, it indicates that previous definitions of probabilistic finite automaton have always been restricted to 1 of 8 classes of automaton and shows that other classes are useful. Third, the probabilistic concept is extended from finite automata to higher level automata (such as probabilistic PDAs and probabilistic Turing automata).