2,347 research outputs found
Integrated Navigation System: Not a Sum of Its Parts
Similar to the evolutionary process for living organisms, marine navigation systems are becoming increasingly complex and sophisticated. Both by design and function, shipboard and shore-based navigation systems are no longer individual equipment components operating independently. Instead, the trend is toward integration, data fusion and synergy. One example of this are new Performance Standards being considered by IMO to achieve a âharmonizedâ presentation of all navigation-related information on the display of an integrated navigation system (INS). Unlike a dedicated display for ECDIS or radar, the new INS displays will be a task-oriented composite presentations that enable the mariner to configure the display for an operational situation by selecting specific chart, radar, radar plotting aids (ARPA) and AIS information that is required for the task-at-hand. This paper gives a brief overview of the trend toward the development of INS. In addition to a brief summary of IMO performance standards for navigation equipment/systems, specific mention is made about a BSH (Germany) report on the âFunctional Scope and Model of INS.â A discussion is provided about the challenges of providing navigation safety information that goes beyond traditional boundaries of products and services. Currently, many agencies continue to produce individual products and services on a component basis. Hydrographic offices grapple with trying to provide multiple products and services for paper charts, raster navigational charts (RNCs) and electronic navigational charts (ENCs) while a same time, Coast Guard and Maritime Safety agencies focus on improving Aids-to-Navigation (AtoN), Vessel Traffic Services (VTS), AIS networks -- and more recently, port security. In some respects, the continued concentration on separate products and services represents an organizational reluctance to change. This in turn, results in a fragmented, sub-optimal approach to the safety-of-navigation caused by the inability to provide mariners with âseamlessâ information at reasonable cost. In particular, hydrographic offices must be willing to recognize that chart information can no longer be considered to be separate, individual products. When it comes to the provision and use of chart-related information for use in an INS, the focus needs to shift to what information is actually desired, how it will be provided, what other information it will be used with, and whether it is truly up-todate
Stuttgart Interconnection Network Project from PIX to NICS
The PIX follow-up project NICS is described. The purpose of PIX was access to X.25, the DATEX-P network of the Federal German Post Office. The development and implementation of higher protocols for levels 4-7 in the ISOSINN was the actual problem here. Results of the PIX project are given. NICS (Stuttgart Interconnection Network Project) is presented. International Protocols are reviewed. PAD service is described, which allows terminal access to DATEX-P network of the Federal German Post Office
Man's space venture
Manned space flight - scientific, technological and sociological backgroun
The Beginnings and Prospective Ending of âEnd-to-Endâ: An Evolutionary Perspective On the Internetâs Architecture
The technology of âthe Internetâ is not static. Although its âend-to- endâ architecture has made this âconnection-lessâ communications system readily âextensible,â and highly encouraging to innovation both in hardware and software applications, there are strong pressures for engineering changes. Some of these are wanted to support novel transport services (e.g. voice telephony, real-time video); others would address drawbacks that appeared with opening of the Internet to public and commercial traffic - e.g., the difficulties of blocking delivery of offensive content, suppressing malicious actions (e.g. âdenial of serviceâ attacks), pricing bandwidth usage to reduce congestion. The expected gains from making âimprovementsâ in the core of the network should be weighed against the loss of the social and economic benefits that derive from the âend-to-endâ architectural design. Even where technological âfixesâ can be placed at the networksâ edges, the option remains to search for alternative, institutional mechanisms of governing conduct in cyberspace.
Submicron Systems Architecture Project : Semiannual Technical Report
The Mosaic C is an experimental fine-grain multicomputer
based on single-chip nodes. The Mosaic C chip includes 64KB of fast dynamic RAM,
processor, packet interface, ROM for bootstrap and self-test, and a two-dimensional selftimed
router. The chip architecture provides low-overhead and low-latency handling of
message packets, and high memory and network bandwidth. Sixty-four Mosaic chips are
packaged by tape-automated bonding (TAB) in an 8 x 8 array on circuit boards that can, in
turn, be arrayed in two dimensions to build arbitrarily large machines. These 8 x 8 boards are
now in prototype production under a subcontract with Hewlett-Packard. We are planning
to construct a 16K-node Mosaic C system from 256 of these boards. The suite of Mosaic
C hardware also includes host-interface boards and high-speed communication cables. The
hardware developments and activities of the past eight months are described in section 2.1.
The programming system that we are developing for the Mosaic C is based on the
same message-passing, reactive-process, computational model that we have used with earlier
multicomputers, but the model is implemented for the Mosaic in a way that supports finegrain
concurrency. A process executes only in response to receiving a message, and may in
execution send messages, create new processes, and modify its persistent variables before
it either exits or becomes dormant in preparation for receiving another message. These
computations are expressed in an object-oriented programming notation, a derivative of
C++ called C+-. The computational model and the C+- programming notation are
described in section 2.2. The Mosaic C runtime system, which is written in C+-, provides
automatic process placement and highly distributed management of system resources. The
Mosaic C runtime system is described in section 2.3
Feasibility study for the implementation of NASTRAN on the ILLIAC 4 parallel processor
The ILLIAC IV, a fourth generation multiprocessor using parallel processing hardware concepts, is operational at Moffett Field, California. Its capability to excel at matrix manipulation, makes the ILLIAC well suited for performing structural analyses using the finite element displacement method. The feasibility of modifying the NASTRAN (NASA structural analysis) computer program to make effective use of the ILLIAC IV was investigated. The characteristics are summarized of the ILLIAC and the ARPANET, a telecommunications network which spans the continent making the ILLIAC accessible to nearly all major industrial centers in the United States. Two distinct approaches are studied: retaining NASTRAN as it now operates on many of the host computers of the ARPANET to process the input and output while using the ILLIAC only for the major computational tasks, and installing NASTRAN to operate entirely in the ILLIAC environment. Though both alternatives offer similar and significant increases in computational speed over modern third generation processors, the full installation of NASTRAN on the ILLIAC is recommended. Specifications are presented for performing that task with manpower estimates and schedules to correspond
Analysis and Identification of Requirements for a System to Enhance Situational Awareness at Sea
This paper presents the research results of identifying and analyzing key requirements for the ESABALT system based on pre-defined user profile groups. These requirements have been identified through multiple sources, which include an electronic survey of potential users of the system, interviews with specialists in navigation, law and computer science, analysis of state-of-the-art in maritime safety procedures, and study of past R&D projects in this field. Finally, these requirements are classified into user level, domain level and system level requirements for easy interpretation while designing the system architecture and its function-al specifications. The presented system specification is discussed
Research in the Aloha system
The Aloha system was studied and developed and extended to advanced forms of computer communications networks. Theoretical and simulation studies of Aloha type radio channels for use in packet switched communications networks were performed. Improved versions of the Aloha communications techniques and their extensions were tested experimentally. A packet radio repeater suitable for use with the Aloha system operational network was developed. General studies of the organization of multiprocessor systems centered on the development of the BCC 500 computer were concluded
Submicron Systems Architecture Project: Semiannual Technial Report
No abstract available
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