7,488 research outputs found
Toward a North American Standard for Mobile Data Services
The rapid introduction of digital mobile communications systems is an important part of the emerging digital communications scene. These developments pose both a potential problem and a challenge. On one hand, these separate market driven developments can result in an uncontrolled mixture of analog and digital links which inhibit data modem services across the mobile/Public Switched network (PSTN). On the other hand, the near coincidence of schedules for development of some of these systems, i.e., Digital Cellular, Mobile Satellite, Land Mobile Radio, and ISDN, provides an opportunity to address interoperability problems by defining interfaces, control, and service standards that are compatible among these new services. In this paper we address the problem of providing data services interoperation between mobile terminals and data devices on the PSTN. The expected data services include G3 Fax, asynchronous data, and the government's STU-3 secure voice system, and future data services such as ISDN. We address a common architecture and a limited set of issues that are key to interoperable mobile data services. We believe that common mobile data standards will both improve the quality of data service and simplify the systems for manufacturers, data users, and service providers
Gallery Characteristics and Life History of the Ambrosia Beetle Trypodendron betulae (Coleoptera: Curculionidae: Scolytinae) in Birch
Trypodendron betulae Swaine distributed attack entrance holes uniformly over the surface of standing stressed sub-canopy birch trees. Male and female pairs constructed galleries consisting of an entrance tunnel about 20 mm in length and then primary and secondary lateral tunnels averaging between 16 and 23 mm in length into the sapwood. Egg niches were constructed in the lateral tunnels after the symbiotic fungus was established in the galleries. Larvae enlarged the niches into cradles. Pupae and eventually teneral adults developed in the cradles. The sex ratio of resulting progeny adults was approximately one to one, and they emerged from galleries in September to overwinter in the litter
Earthquake Prediction and Hazards Evaluation in the Year 2000 -- A Dialogue
Decisionmakers have different perspectives about geologic hazards than
scientists and engineers.
These differences, which have been summarized by
Szanton (1981, table 3-1), are the reasons that implementation of loss reduction
measures are difficult. The differences are:
The ultimate objective of the decisionmaker is the approval of the
electorate; it is the respect of peers for the scientist/engineer;
The time horizon for the decisionmaker is short; it is long for the
scientist/engineer;
The focus of the decisionmaker is on the external logic of the problem;
it is on the internal logic for the scientist/engineer;
The mode of thought for the decisionmaker is deductive and particular;
it is inductive and generic for the scientist/engineer;
The most valued outcome for the decisionmaker is a reliable solution; it
is original insight for the scientist/engineer;
The mode of expression is simple and absolute for the decisionmaker; it
is abstruse and qualified for the scientist/engineer, and;
The preferred form of conclusion for the decisionmaker is one of "best
solution" with uncertainties submerged; it is multiple possibilities with
uncertainties emphasized for the scientist/engineer.
With these principles in mind, let us now turn the clock forward to the year 2000
and a discussion between a decisionmaker and a scientist as they seek to resolve
their philosophical differences and reach solutions to problems of earthquake-hazards
reduction
Great Expectations: Privacy Rights in Automobiles
The authors examine the history of the standing doctrine as it relates to the ability to contest searches and seizures. After analyzing the cases in this area, the recent Supreme Court case of Rakas v. Illinois is discussed and critiqued in depth. Cases decided after Rakas serve as the backdrop for a discussion of the exclusionary rule and the privacy rights of automobile passengers. Finally, the authors propose an alternative to the Rakas holding
Great Expectations: Privacy Rights in Automobiles
The authors examine the history of the standing doctrine as it relates to the ability to contest searches and seizures. After analyzing the cases in this area, the recent Supreme Court case of Rakas v. Illinois is discussed and critiqued in depth. Cases decided after Rakas serve as the backdrop for a discussion of the exclusionary rule and the privacy rights of automobile passengers. Finally, the authors propose an alternative to the Rakas holding
A taxonomic guide to the mysids of the South Atlantic Bight.
Following the examination of extensive collections from the National Museum of Natural History (NMNH), the Southeastern Regional Taxonomic Center (SERTC), and other regional institutions, 18 species of the family Mysidae are recognized and described from the South Atlantic Bight
(Cape Lookout, North Carolina to Cape Canaveral, Florida). This report includes synonymies of previous records, as well as new species distribution records. Previous
regional accounts of Metamysidopsis munda and Metamysidopsis mexicana are attributed to Metamysidopsis swifti. New regional records are established for Amathimysis brattegardi, Heteromysis beetoni, and Siriella thompsonii. Two other species tentatively identified as
Amathimysis sp. (nr. serrata) and Mysidopsis sp. (cf. mortenseni) may represent new taxa. Neobathymysis renoculata is included and discussed as a potential regional species. An illustrated key to the species currently known from the South Atlantic Bight is presented.
Relevant taxonomic, distributional, and ecological information is also included for each species. (PDF file contains 45 pages.
Parasites on parasites:Coupled fluctuations in stacked contact processes
We present a model for host-parasite dynamics which incorporates both vertical and horizontal transmission as well as spatial structure. Our model consists of stacked contact processes (CP), where the dynamics of the host is a simple CP on a lattice while the dynamics of the parasite is a secondary CP which sits on top of the host-occupied sites. In the simplest case, where infection does not incur any cost, we uncover a novel effect: a non-monotonic dependence of parasite prevalence on host turnover. Inspired by natural examples of hyperparasitism, we extend our model to multiple levels of parasites and identify a transition between the maintenance of a finite and infinite number of levels, which we conjecture is connected to a roughening transition in models of surface growth
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