Klaus Meyer-Wegener

Standardising on workflow-management—the OMG workflow management facility

With over 800 members, the Object Management Group (OMG) is the largest international consortium of the software industry. Its goal is not only to promote the use of object technology in general but also to define and standardise on a common architectural framework across heterogeneous hardware platforms and operating systems, called the Object Management Architecture (OMA) [13]. In the standardisation process, the OMG focuses on commercially available object technology. So far, the OMGs efforts have been very successful; most of the specifications have met broad acceptance and are implemented by commercial products. Since 1995, the OMG has followed the plan to extend their reference architecture (see [13,18,36]) with a component that supports workflow management. OMG technology, especially the Common Object Request Broker Architecture (CORBA), and workflow management primarily address the same target users: large, distributed organisations with heterogeneous IT platforms. Therefore, it is quite obvious that a big synergy grows out of the integration of both technologies in building large-scale enterprise solutions.The promotion of workflow management standards is also the goal of another international body, the Workflow Management Coalition (WfMC) [3,31]. Since 1993, the WIMC has produced a number of specifications, mainly an interface model together with interface specifications for workflow management systems [32,33,34,35]. The OMG always assumed that the WIMC standards would fit nicely into the OMA. But in late 1996 it was recognized [23] that the interfaces of the WfMC specifications do not fit seemlessly into the OMG model and that the WfMC will probably fall to meet OMGs expectations (see also [19,22]). Therefore, in January 1997, the OMG Common Facility Task Force voted to reject the WfMCs motion to submit their standards to OMG on a fast-track approval process rather than going through the usual OMG standardisation procedure. The usual OMG process is based on a RFP (Request For Proposals) seeking for submissions for a particular area of standardisation. In almost all cases several submissions emerge which are combined into one revised submission. This submission is voted on and in case of a positive vote adopted by OMG. In early 1997, the OMG established the Workflow workgroup [30] with the charter to create and issue an RFP for an OMG Workflow Management Facility (WfMF). In May 1997, the RFP [15] was issued, asking the software industry for submissions for this new architectural component.This report gives a brief overview of the architectural context, the requirements of the RFP and a short evaluation of the initial submissions. An outlook to potential topics for future workflow RFPs that are collected in a Workflow roadmap document concludes the report.

Runtime adaptation in a service-oriented component model

Developing software applications which manage, optimize or adapt themselves at runtime requires an architecture which provides adaptation of software components at runtime. An architecture model that has gained a lot of attention in recent years is SOA (service-oriented architecture). In a SOA environment services as well as applications build up complex dependencies. Therefore it is crucial for self-managing SOA applications to adapt services at runtime without interference of the application execution and the service availability. In this paper, we discuss the problems arising from the requirement of runtime adaptation and present our solution by replacing service implementations at execution time in a service-oriented component model. For a seamless integration we strive for a transparent and atomic replacement of a service implementation in respect to the other services/applications.

Processing and transaction concepts for cooperation of engineering workstations and a database server

Abstract A DBMS kernel architecture is proposed for improved DB support of engineering applications running on a cluster of workstations. Using such an approach, part of the DBMS code—an application-specific layer—is allocated close to the corresponding application on a workstation while the kernel code is executed on a central server. Emperical performance results from DB-based engineering applications are reported to justify the chosen DBMS architecture. The paper focuses on design issues of the application layer including server coupling, processing model and application interface. Moreover, a transaction model for long-term database work in a coupled workstation-server environment is investigated in detail.

Grand tour of concepts for object-orientation from a database point of view

Abstract Over the last few years, object-orientation has gained more and more importance within several disciplines of computer science (e.g. programming languages, knowledge engineering, and database systems). Numerous papers have defined one or another of its underlying concepts (sometimes in quite different ways), and some systems have been developed following those heterogeneous definitions. Nevertheless, papers investigating the dependencies and degrees of freedom of these concepts are rarely found. For this reason, the goal of this paper is not to add yet another definition of object-oriented concepts, but to identify existing relationships among these basic concepts that allow one to cover and classify various conceivable combinations of these conceptual building blocks. Dependencies, orthogonalities, and relations among concepts like object identity, encapsulation, classification, generalization, inheritance, etc. are revealed, showing numerous ways to compose different shades of object-orientation. This leads to alternatives encountered when constructing object-oriented systems, which are illustrated by classifying some well-known systems and prototypes from different areas. However, it is not our purpose to analyze the relative importance of these concepts. Instead, we investigate the concepts from a neutral point of view, presenting (but not evaluating) several degrees of object-orientation.

NEOCR: a configurable dataset for natural image text recognition

Recently growing attention has been paid to recognizing text in natural images. Natural image text OCR is far more complex than OCR in scanned documents. Text in real world environments appears in arbitrary colors, font sizes and font types, often affected by perspective distortion, lighting effects, textures or occlusion. Currently there are no datasets publicly available which cover all aspects of natural image OCR. We propose a comprehensive well-annotated configurable dataset for optical character recognition in natural images for the evaluation and comparison of approaches tackling with natural image text OCR. Based on the rich annotations of the proposed NEOCR dataset new and more precise evaluations are now possible, which give more detailed information on where improvements are most required in natural image text OCR.

Research: Communication support for cooperative work

Desktop conferencing and distributed graphical editing applications allow people to perform cooperative work regardless of their geographic location. One such example is the CoDraft application presented here. This collaborative system allows concurrent sketching on a shared drawing board. The current version is implemented on top of point-to-point communication services. It is shown that these services are not well suited for cooperative applications. Therefore, a multiparty communication platform is proposed that manages groups of application instances and multicast messages, handles group voting and transfers files to more than one target site at a time. This platform greatly simplifies the development of cooperative applications. Additionally, the platform allows the lower-level multicast functionality to be more fully exploited, thus improving response time and throughput performance.

From radio telemetry to ultra-low-power sensor networks: tracking bats in the wild

Sensor networks have successfully been used for wildlife monitoring and tracking of different species. When it comes to small animals such as smaller birds, mammals, or even insects, the current approach is to use extremely lightweight RF tags located using radio telemetry. A new quantum leap in technology is needed to overcome this limitation and enable new ways to observe larger numbers of small animals. In an interdisciplinary team, we are working on the different aspects of such a new technology. In particular, we report on our findings on a sensor- network-based tracking solution for bats. Our system is based on integrated localization and wireless communication protocols for ultra-low-power systems. This requires coding techniques for improved reliability as well as ranging solutions for tracking hunting bats. We address the technological and methodical problems related to system design, software support, and protocol design. First field experiments have been conducted that showcase the capabilities of our system.

An architecture for a multimedia database management system supporting content search

Advanced applications frequently require the management of multimedia data like text, images, graphics, sound, etc. While it is practical for todays computers to store these types of data, managing them requires the search of them based on their contents. Database management systems should be extended to organize these new types of data and to enable content search. However, the complexity of the contents and their semantics makes content search of these data a very difficult problem. This paper proposes to have multimedia data accompanied by natural language descriptions that will be used for content search of these data. A parser is used to interpret the descriptions and to later match them semantically with queries. Implications and difficulties of such an approach are discussed.

Services of Workflow Objects and Workflow Meta-Objects in OMG-compliant Environments

The Object Management Group (OMG) has recognized that having workflow-management functionality would greatly enhance acceptance and momentum of their reference architecture. The Workflow-Management-Coalition (WfMC) is likely to propose a standard for an OMG Workflow Facility that might suffer from some important drawbacks. This paper identifies some of the inadequacies and proposes eight statements that might be helpful to find a better alternative.

A new approach to modular database systems

In this paper we present our approach towards a modularized database management system (DBMS) whose components can be adapted at runtime and show the modularization of a DBMS beneath the record-oriented interface as a first step. Cross-cutting concerns like transactions pose thereby a challenge that we answer with aspect-oriented programming (AOP). Finally we show the implementation techniques that enable the exchange of database modules dynamically. Particularly with regard to stateful components we define a service adaptation process that preserves and transmits the components state.