49,686 research outputs found
A Perspective on Resource Synchronization
Web applications frequently leverage resources made available by remote web servers. As resources are created, updated, deleted, or moved, these applications face challenges to remain in lockstep with changes on the server. Several approaches exist to help meet this challenge for use cases where good enough synchronization is acceptable. But when strict resource coverage or low synchronization latency is required, commonly accepted Web-based solutions remain illusive. This paper provides a perspective on the resource synchronization problem that results from inspiration gained from prior work, and initial insights resulting from the recently launched NISO/OAI ResourceSync effort
A Technical Framework for Resource Synchronization
This is the second paper in D-Lib Magazine about the ResourceSync effort conducted by the National Information Standards Organization (NISO) and the Open Archives Initiative (OAI). The first part provided a perspective on the resource synchronization problem and introduced a template that organized possible components of a resource synchronization framework in a modular manner. This paper details a technical framework devised using that template
Millimeter Wave Cellular Networks: A MAC Layer Perspective
The millimeter wave (mmWave) frequency band is seen as a key enabler of
multi-gigabit wireless access in future cellular networks. In order to overcome
the propagation challenges, mmWave systems use a large number of antenna
elements both at the base station and at the user equipment, which lead to high
directivity gains, fully-directional communications, and possible noise-limited
operations. The fundamental differences between mmWave networks and traditional
ones challenge the classical design constraints, objectives, and available
degrees of freedom. This paper addresses the implications that highly
directional communication has on the design of an efficient medium access
control (MAC) layer. The paper discusses key MAC layer issues, such as
synchronization, random access, handover, channelization, interference
management, scheduling, and association. The paper provides an integrated view
on MAC layer issues for cellular networks, identifies new challenges and
tradeoffs, and provides novel insights and solution approaches.Comment: 21 pages, 9 figures, 2 tables, to appear in IEEE Transactions on
Communication
Extending Sitemaps for ResourceSync
The documents used in the ResourceSync synchronization framework are based on
the widely adopted document format defined by the Sitemap protocol. In order to
address requirements of the framework, extensions to the Sitemap format were
necessary. This short paper describes the concerns we had about introducing
such extensions, the tests we did to evaluate their validity, and aspects of
the framework to address them.Comment: 4 pages, 6 listings, accepted at JCDL 201
Patterns-based Evaluation of Open Source BPM Systems: The Cases of jBPM, OpenWFE, and Enhydra Shark
In keeping with the proliferation of free software development initiatives and the increased interest in the business process management domain, many open source workflow and business process management systems have appeared during the last few years and are now under active development. This upsurge gives rise to two important questions: what are the capabilities of these systems? and how do they compare to each other and to their closed source counterparts? i.e. in other words what is the state-of-the-art in the area?. To gain an insight into the area, we have conducted an in-depth analysis of three of the major open source workflow management systems - jBPM, OpenWFE and Enhydra Shark, the results of which are reported here. This analysis is based on the workflow patterns framework and provides a continuation of the series of evaluations performed using the same framework on closed source systems, business process modeling languages and web-service composition standards. The results from evaluations of the three open source systems are compared with each other and also with the results from evaluations of three representative closed source systems - Staffware, WebSphere MQ and Oracle BPEL PM, documented in earlier works. The overall conclusion is that open source systems are targeted more toward developers rather than business analysts. They generally provide less support for the patterns than closed source systems, particularly with respect to the resource perspective which describes the various ways in which work is distributed amongst business users and managed through to completion
IUPC: Identification and Unification of Process Constraints
Business Process Compliance (BPC) has gained significant momentum in research
and practice during the last years. Although many approaches address BPC, they
mostly assume the existence of some kind of unified base of process constraints
and focus on their verification over the business processes. However, it
remains unclear how such an inte- grated process constraint base can be built
up, even though this con- stitutes the essential prerequisite for all further
compliance checks. In addition, the heterogeneity of process constraints has
been neglected so far. Without identification and separation of process
constraints from domain rules as well as unification of process constraints,
the success- ful IT support of BPC will not be possible. In this technical
report we introduce a unified representation framework that enables the
identifica- tion of process constraints from domain rules and their later
unification within a process constraint base. Separating process constraints
from domain rules can lead to significant reduction of compliance checking
effort. Unification enables consistency checks and optimizations as well as
maintenance and evolution of the constraint base on the other side.Comment: 13 pages, 4 figures, technical repor
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