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Articles 1 - 7 of 7
Full-Text Articles in Physical Sciences and Mathematics
Sketch-Based Queries In Mobile Gis-Environments, David Caduff
Sketch-Based Queries In Mobile Gis-Environments, David Caduff
Electronic Theses and Dissertations
Recent achievements in the field of mobile computing and wireless communication promise data retrieval anywhere and anytime. This development provided the basis to expand GIs technology to handheld devices, such as personal digital assistants (PDAs). Although traditional GIs technology is well suited for desktop workstations, it needs to be adapted in order to satisfy the requirements of users using handheld computing devices. This adaptation is necessary because the usability of traditional GISs depends on characteristics of desktop computers, such as their relatively large user interfaces (e.g., displays, keyboards, pointing devices), considerable computing resources (i.e., CPU, memory, storage, operating systems), and …
Toward Dynamic Interoperability Of Mobile Agent Systems, Arne Grimstrup, Robert Gray, David Kotz, Maggie Breedy, Marco Carvalho, Thomas Cowin, Daria Chacon, Joyce Barton, Chris Garrett, Martin Hofmann
Toward Dynamic Interoperability Of Mobile Agent Systems, Arne Grimstrup, Robert Gray, David Kotz, Maggie Breedy, Marco Carvalho, Thomas Cowin, Daria Chacon, Joyce Barton, Chris Garrett, Martin Hofmann
Dartmouth Scholarship
Mobile agents are an increasingly popular paradigm and in recent years there has been a proliferation of mobile-agent systems. These systems are, however, largely incompatible with each other. In particular, agents cannot migrate to a host that runs a different mobile-agent system. Prior approaches to interoperability have tried to force agents to use a common API and so far none have succeeded. This goal led to our efforts to develop mechanisms that support dynamic runtime interoperability of mobile-agent systems. This paper describes the \em Grid Mobile-Agent System, which allows agents to migrate to different mobile-agent systems.
Cache Invalidation And Replacement Strategies For Location-Dependent Data In Mobile Environments, Baihua Zheng, Jianliang Xu, Dik Lun Lee
Cache Invalidation And Replacement Strategies For Location-Dependent Data In Mobile Environments, Baihua Zheng, Jianliang Xu, Dik Lun Lee
Research Collection School Of Computing and Information Systems
Mobile location-dependent information services (LDISs) have become increasingly popular in recent years. However, data caching strategies for LDISs have thus far received little attention. In this paper, we study the issues of cache invalidation and cache replacement for location-dependent data under a geometric location model. We introduce a new performance criterion, called caching efficiency, and propose a generic method for location-dependent cache invalidation strategies. In addition, two cache replacement policies, PA and PAID, are proposed. Unlike the conventional replacement policies, PA and PAID take into consideration the valid scope area of a data value. We conduct a series of simulation …
Analysis Of A Campus-Wide Wireless Network, David Kotz, Kobby Essien
Analysis Of A Campus-Wide Wireless Network, David Kotz, Kobby Essien
Dartmouth Scholarship
Understanding usage patterns in wireless local-area networks (WLANs) is critical for those who develop, deploy, and manage WLAN technology, as well as those who develop systems and application software for wireless networks. This paper presents results from the largest and most comprehensive trace of network activity in a large, production wireless LAN. For eleven weeks we traced the activity of nearly two thousand users drawn from a general campus population, using a campus-wide network of 476 access points spread over 161 buildings. Our study expands on those done by Tang and Baker, with a significantly larger and broader population. \par …
Future Directions For Mobile-Agent Research, David Kotz, Robert Gray, Daniela Rus
Future Directions For Mobile-Agent Research, David Kotz, Robert Gray, Daniela Rus
Dartmouth Scholarship
The field of mobile agents should shift its emphasis toward mobile code, in all its forms, rather than continue focusing on mobile agents. The development of modular components will help application designers take advantage of code mobility without having to rewrite their applications to fit in monolithic, mobile agent systems.
Solar: An Open Platform For Context-Aware Mobile Applications, Guanling Chen, David Kotz
Solar: An Open Platform For Context-Aware Mobile Applications, Guanling Chen, David Kotz
Dartmouth Scholarship
Emerging pervasive computing technologies transform the way we live and work by embedding computation in our surrounding environment. To avoid increasing complexity, and allow the user to concentrate on her tasks, applications in a pervasive computing environment must automatically adapt to their changing \em context, including the user state and the physical and computational environment in which they run. Solar is a middleware platform to help these “context-aware” applications aggregate desired context from heterogeneous sources and to locate environmental services depending on the current context. By moving most of the context computation into the infrastructure, Solar allows applications to run …
Mobile Voice Over Ip (Mvoip): An Application-Level Protocol For Call Hand-Off In Real Time Applications, G. Ayorkor Mills-Tettey, David Kotz
Mobile Voice Over Ip (Mvoip): An Application-Level Protocol For Call Hand-Off In Real Time Applications, G. Ayorkor Mills-Tettey, David Kotz
Dartmouth Scholarship
This paper presents Mobile Voice Over IP, an application-level protocol to support terminal mobility in real-time applications such as voice over IP, on a wireless local area network. We describe our MVOIP implementation based on the ITU-T H.323 protocol stack, present experimental results on call hand-off latency, and discuss various implementation issues, including the task of quickly and accurately determining when call hand-off is necessary. We also discuss how MVOIP relates to other proposed mobility support schemes, and how it can be generalized to provide application-level mobility support in a wide range of real and non real-time applications.