10909052
Trust in the preservation of digital information
An institutional guarantee can help address the major hurdle of digital preservation---winning people's trust.
29068512
Perceptions of credibility of scholarly information on the web
The purpose of this study is to investigate factors influencing students' perception of the credibility of scholarly information on the web. In addition to the four types of source credibility proposed by previous studies (presumed credibility, reputed credibility, surface credibility, and experienced credibility), this study shows that two other types of source credibility (verifiable credibility and cost-effort credibility) play a significant role in shaping students' perceptions of credibility. Circumstances that affect students' willingness to accept scholarly information on the web are identified. Implications for web system design are also discussed.
34520117
Print vs. electronic resources: A study of user perceptions, preferences, and use
The arrival and proliferation of electronic resources and digital libraries have a number of significant impacts on the use of print resources and traditional libraries. This study explores the extent to which graduate students in a metropolitan university setting use print and electronic resources. Reading preferences and use of print and electronic resources vary among different disciplines. Graduate students seem to expect a hybrid of print and electronic resources. They desire to meet their information needs through a mix of print and online resources, even though reasons for supplementing another type of resource differ. Circumstances that affect the selection of use between digital libraries and traditional libraries are also discussed.
7602869
Intergenerational Partnerships in the Design of a Digital Library of Geography Examination Resources
This paper describes the engagement of intergenerational partners in the design of a digital library of geographical resources (GeogDL) to help prepare Singapore students for a national examination in geography. GeogDL is built on top of G-Portal, a digital library providing services over geospatial and georeferenced Web content. Scenario-based design and claims analysis were employed as a means of refinement to the initial design of the GeogDL prototype.
7550543
A digital library for geography examination resources
We describe a Web-based application developed above a digital library of geographical resources for Singapore students preparing to take a national examination in geography. The application provides an interactive, non-sequential approach to learning that supplements textbooks.
2119274
Dynamical mobile terminal location registration in wireless PCS networks
In this paper, we propose a mobile terminal (MT) location registration/update model. In this model, the registration decision is based on two factors-the time elapsed since last call arrival and the distance the MT has traveled since last registration. It is established that the optimal registration strategy can be represented by a curve. Only when the state of the system reaches this curve is a registration performed. In order for an MT to calculate its traveled distance, an interactive implementation scheme and a distance calculation algorithm are developed. When the call interarrival times are independent and geometrically distributed, the proposed model becomes a distance-based model and, in this case, the optimal registration strategy is of threshold structure. For the distance-based model, a single sample path-based ordinal optimization algorithm is devised. In this algorithm, without any knowledge about the system parameters, the MT observes the system state transitions, estimates the ordinal of a set of strategies, and updates the registration strategy adaptively. Since only a single sample path is used, this algorithm can be implemented online. Several numerical examples are provided to compare the proposed model and the existing ones.
242170
Active security support for active networks
Active networks aim to provide a software framework that enables network applications to customize the processing of their communication packets. Security is of critical importance to the success of active networking. This paper presents a design and a description of the implementation for securing the node of an active network using active networking principles. The secure node architecture includes an active node operating system security API, an active security guardian, and quality of protection (QoP) provisions. The architecture supports highly customized and situational policies created by users and applications dynamically. It permits active nodes to satisfy the application-specific dynamic security and protection requirements. The secure node architecture can provide a fundamental base for securing the active network infrastructure. We describe the integration of secure node architecture into an active network software system to demonstrate its flexible and innovative features.
17293889
Complexity of Task Graph Scheduling with Fixed Communication Capacity
Consider a scheduling problem of parallel computations in multiprocessor systems. Let a parallel program be modeled by a task graph, where vertices represent tasks and arcs the communications between tasks. An interprocessor communication time incurs when two tasks assigned to two different processors have to communicate. Such a scheduling problem has recently been studied in the literature, mostly for the case where interprocessor communication times are fully determined. In this paper, we consider the scheduling problem with communication resource constraints. More specifically, we consider the case where all interprocessor communications take place on a network of bounded capacity. We consider two variants of the problem: communications with independent-data semantics and common-data semantics. We show that even for very specific subproblems, viz. scheduling of general graphs on two processors and scheduling of binary trees on an infinite number of processors, the minimization of the makespan of parallel programs in such a multiprocessor system is strongly -hard. We first establish the results for the case of capacity 1, referred to as the single-bus system. We then extend the results to the more general case of fixed communication capacities. As a consequence, the general scheduling problem of parallel programs with communication resource constraints is strongly -hard. These results are to be contrasted with the corresponding scheduling problems without contraint on the communication capacity, where the two-processor case has unknown time complexity and the infinite-processor case is polynomial. Our results are also extended to the case of broadcasting communications, and can be applied to multiprocessor systems with shared memory.