On the relation between the base of an EI algebra and word graphs

This paper is an attempt to investigate the possibilities to link algebraic fuzzy set theory with the theory of word graphs. In both theories concepts are studied and concepts can be set in correspondence. This enables to use algebraic results in the context of word graph theory

Peephole Log Optimization

The log files generated while operating a file system in disconnected mode grow to substantial sizes. Eliminating redundant or useless operations in these logs can free up scarce disk space on laptops, reduce replay times, and reduce the frequency of data conflict. Our approach uses a rule-based portable peephole optimizer for compilers. This work suggests a general method of optimization for any system that performs logging at the vnode layer.http://deepblue.lib.umich.edu/bitstream/2027.42/107933/1/citi-tr-95-3.pd

Evaluating Delayed Write in a Multilevel Caching File System

Delayed write in a multilevel file system cache hierarchy offers a way to improve performance in diverse client/server scenarios, such as integrating mass store into a distributed file system or providing distributed file system access over low-speed links. Using file system traces and cache simulations, we explore extensions and modifications to the traditional client caching model employed in such file systems as AFS, Sprite, and DFS. High cache hit rates at an intermediate cache server—a machine logically interposed between clients and servers that provides cached file service to the clients—combined with high client cache hit rates lend practicality to an integrated mass storage file system. In such a system, magnetic tape or optical-based mass storage devices may be used as a first-class data repository, fronted by disk and RAM caches to offer acceptable access times to the large, but slow, mass storage system. Similarly, a high cache hit rate is necessary for users accessing file systems via low-speed links, where a delayed write intermediate caching server can mediate traffic to make better use of available bandwidth. In an example taken from mobile computing, an intermediate server might be used as a docking station at a user's home. This arrangement would be convenient for users of mobile computers who upload large amounts of data generated while operating in disconnected mode. Simulations of delayed write caching strategies are applicable to both the mass storage and low-speed link scenarios.http://deepblue.lib.umich.edu/bitstream/2027.42/107940/1/citi-tr-95-9.pd

A distributed directory scheme for information access in mobile computers

In this paper, we discuss the design aspects of a dynamic distributed directory scheme (DDS) to facilitate efficient and transparent access to information files in mobile environments. The proposed directory interface enables users of mobile computers to view a distributed file system on a network of computers as a globally shared file system. In order to counter some of the limitations of wireless communications, we propose improvised invalidation schemes that avoid false sharing and ensure uninterrupted usage under disconnected and low bandwidth conditions

Collaborative research on V/STOL control system/cockpit display tradeoffs under the NASA/MOD joint aeronautical program

Summarized here are activities that have taken place from 1979 to the present in a collaborative program between NASA Ames Research Center and the Royal Aerospace Establishment (now Defence Research Agency), Bedford on flight control system and cockpit display tradeoffs for low-speed and hover operations of future V/STOL aircraft. This program was created as Task 8A of the Joint Aeronautical Program between NASA in the United States and the Ministry of Defence (Procurement Executive) in the United Kingdom. The program was initiated based on a recognition by both parties of the strengths of the efforts of their counterparts and a desire to participate jointly in future simulation and flight experiments. In the ensuing years, teams of NASA and RAE engineers and pilots have participated in each other's simulation experiments to evaluate control and display concepts and define design requirements for research aircraft. Both organizations possess Harrier airframes that have undergone extensive modification to provide in-flight research capabilities in the subject areas. Both NASA and RAE have profited by exchanges of control/display concepts, design criteria, fabrication techniques, software development and validation, installation details, and ground and flight clearance techniques for their respective aircraft. This collaboration has permitted the two organizations to achieve jointly substantially more during the period than if they had worked independently. The two organizations are now entering the phase of flight research for the collaborative program as currently defined

Double parton scatterings in high energy hadronic collisions

CDF has recently measured a large number of double parton scatterings. The observed value of $\sigma_{eff}$, the non perturbative parameter which characterizes the process, is considerably smaller as compared with the naive expectation. The small value of $\sigma_{eff}$ is likely to be an indication of the importance of the two-body parton correlations in the many-body parton distributions of the proton.Comment: 8 pages, latex file, no figures, contributions to the proceedings of the ISMD9