Department of Computer Science Activity 1998-2004

This report summarizes much of the research and teaching activity of the Department of Computer Science at Dartmouth College between late 1998 and late 2004. The material for this report was collected as part of the final report for NSF Institutional Infrastructure award EIA-9802068, which funded equipment and technical staff during that six-year period. This equipment and staff supported essentially all of the department\u27s research activity during that period

Resource-constraint And Scalable Data Distribution Management For High Level Architecture

In this dissertation, we present an efficient algorithm, called P-Pruning algorithm, for data distribution management problem in High Level Architecture. High Level Architecture (HLA) presents a framework for modeling and simulation within the Department of Defense (DoD) and forms the basis of IEEE 1516 standard. The goal of this architecture is to interoperate multiple simulations and facilitate the reuse of simulation components. Data Distribution Management (DDM) is one of the six components in HLA that is responsible for limiting and controlling the data exchanged in a simulation and reducing the processing requirements of federates. DDM is also an important problem in the parallel and distributed computing domain, especially in large-scale distributed modeling and simulation applications, where control on data exchange among the simulated entities is required. We present a performance-evaluation simulation study of the P-Pruning algorithm against three techniques: region-matching, fixed-grid, and dynamic-grid DDM algorithms. The P-Pruning algorithm is faster than region-matching, fixed-grid, and dynamic-grid DDM algorithms as it avoid the quadratic computation step involved in other algorithms. The simulation results show that the P-Pruning DDM algorithm uses memory at run-time more efficiently and requires less number of multicast groups as compared to the three algorithms. To increase the scalability of P-Pruning algorithm, we develop a resource-efficient enhancement for the P-Pruning algorithm. We also present a performance evaluation study of this resource-efficient algorithm in a memory-constraint environment. The Memory-Constraint P-Pruning algorithm deploys I/O efficient data-structures for optimized memory access at run-time. The simulation results show that the Memory-Constraint P-Pruning DDM algorithm is faster than the P-Pruning algorithm and utilizes memory at run-time more efficiently. It is suitable for high performance distributed simulation applications as it improves the scalability of the P-Pruning algorithm by several order in terms of number of federates. We analyze the computation complexity of the P-Pruning algorithm using average-case analysis. We have also extended the P-Pruning algorithm to three-dimensional routing space. In addition, we present the P-Pruning algorithm for dynamic conditions where the distribution of federated is changing at run-time. The dynamic P-Pruning algorithm investigates the changes among federates regions and rebuilds all the affected multicast groups. We have also integrated the P-Pruning algorithm with FDK, an implementation of the HLA architecture. The integration involves the design and implementation of the communicator module for mapping federate interest regions. We provide a modular overview of P-Pruning algorithm components and describe the functional flow for creating multicast groups during simulation. We investigate the deficiencies in DDM implementation under FDK and suggest an approach to overcome them using P-Pruning algorithm. We have enhanced FDK from its existing HLA 1.3 specification by using IEEE 1516 standard for DDM implementation. We provide the system setup instructions and communication routines for running the integrated on a network of machines. We also describe implementation details involved in integration of P-Pruning algorithm with FDK and provide results of our experiences

Microelectromechanical Systems and Devices

The advances of microelectromechanical systems (MEMS) and devices have been instrumental in the demonstration of new devices and applications, and even in the creation of new fields of research and development: bioMEMS, actuators, microfluidic devices, RF and optical MEMS. Experience indicates a need for MEMS book covering these materials as well as the most important process steps in bulk micro-machining and modeling. We are very pleased to present this book that contains 18 chapters, written by the experts in the field of MEMS. These chapters are groups into four broad sections of BioMEMS Devices, MEMS characterization and micromachining, RF and Optical MEMS, and MEMS based Actuators. The book starts with the emerging field of bioMEMS, including MEMS coil for retinal prostheses, DNA extraction by micro/bio-fluidics devices and acoustic biosensors. MEMS characterization, micromachining, macromodels, RF and Optical MEMS switches are discussed in next sections. The book concludes with the emphasis on MEMS based actuators

Modern Telemetry

Telemetry is based on knowledge of various disciplines like Electronics, Measurement, Control and Communication along with their combination. This fact leads to a need of studying and understanding of these principles before the usage of Telemetry on selected problem solving. Spending time is however many times returned in form of obtained data or knowledge which telemetry system can provide. Usage of telemetry can be found in many areas from military through biomedical to real medical applications. Modern way to create a wireless sensors remotely connected to central system with artificial intelligence provide many new, sometimes unusual ways to get a knowledge about remote objects behaviour. This book is intended to present some new up to date accesses to telemetry problems solving by use of new sensors conceptions, new wireless transfer or communication techniques, data collection or processing techniques as well as several real use case scenarios describing model examples. Most of book chapters deals with many real cases of telemetry issues which can be used as a cookbooks for your own telemetry related problems

Energy: A continuing bibliography with indexes, issue 39

This bibliography lists 1377 reports, articles and other documents introduced into the NASA scientific and technical information system from July 1, 1983 through September 30, 1983

IKUWA6. Shared Heritage

Celebrating the theme ‘Shared heritage’, IKUWA6 (the 6th International Congress for Underwater Archaeology), was the first such major conference to be held in the Asia-Pacific region, and the first IKUWA meeting hosted outside Europe since the organisation’s inception in Germany in the 1990s. A primary objective of holding IKUWA6 in Australia was to give greater voice to practitioners and emerging researchers across the Asia and Pacific regions who are often not well represented in northern hemisphere scientific gatherings of this scale; and, to focus on the areas of overlap in our mutual heritage, techniques and technology. Drawing together peer-reviewed presentations by delegates from across the world who converged in Fremantle in 2016 to participate, this volume covers a stimulating diversity of themes and niche topics of value to maritime archaeology practitioners, researchers, students, historians and museum professionals across the world

Multimetal smithing : An urban craft in rural settings?

Multimetal smithing should be defined as the use of more than one metal and/or different metalworking techniques within thesame crafts-milieu. This complex metalworking has long been linked to centrality, central places and urbanity in Scandinavia.It has been extensively argued that fine casting and smithing, as well as manufacture utilizing precious metals was exclusivelyundertaken within early urban settings or the “central places” pre-dating these. Furthermore, the presence of complex metalcraftsmanship has been used as a driving indicator of the political, social and economic superiority of certain sites, therebyenhancing their identity as “centralities”.Recent research has come to challenge the universality of this link between urbanity, centrality and complex metalworkingas sites in rural settings with evidence of multimetal smithing are being identified. This shows that the relationship between thecraft and centrality (urbanity) must be nuanced and that perhaps multimetal craftsmanship should be reconsidered as an urbanindicator.The thesis project “From Crucible and onto Anvil” started in 2015 and focuses on sites housing remains of multimetalcraftsmanship dating primarily from 500-1000 AD. Within the project a comprehensive survey of sites will be used to evaluate thepresence of multimetal craftsmanship in the landscape. Sites in selected target areas will also be subject to intra-site analysisfocusing on workshop organisation, production output, metalworking techniques and chronological variances.A key aim in the project is to elucidate the conceptual aspects of complex metalworking. The term multimetality is used toanalytically frame all the societal and economic aspects of multimetal craftsmanship. Through this inclusive perspective both thecraftsmanship and the metalworkers behind it are positioned within the overall socioeconomic framework. The metalworkers,their skills and competences as well as the products of their labour are viewed as dynamic actors in the landscape and on thearenas of political economy of the Late Iron Age.The survey has already revealed interesting aspects concerning multimetal smithing and urbanity. Although the multimetalsites do cluster against areas of early urban development there are also other patterns emerging. Multimetal craftsmanship – both as practice and concept – was well represented in both rural peripheral settings and urban crafts-milieus. This means that therole of multimetality as part of an “urban conceptual package” is crucial to investigate. Such an approach will have the dual endsof properly understanding the craft and its societal implications, but also further the knowledge of the phenomenon of urbanityas a whole. Was multimetal smithing part of an “urban package” that spread into the rural landscape? Did the multimetality differbetween urban and rural crafts-milieus? How does early urbanity relate to the chronology of multimetal craftsmanship?This paper aims to counter these questions using examples from the survey of multimetal sites conducted within the thesisproject. A comparison between selected sites will be presented. The purpose of this is to evaluate the role of multimetality withinthe “urban package” and discuss the role of complex metalworking in the establishment of urban arenas of interaction in LateIron Age Scandinavia