NAVAL OCEAN SYSTEMS CENTER SAN DIEGO CA
Most widely held works by NAVAL OCEAN SYSTEMS CENTER SAN DIEGO CA
Fiber-Optic Communication Links for Unmanned Inspection Submersibles ( Book )
1 edition published in 1980 in English and held by 4 libraries worldwide
Periodic inspection of undersea pipelines and offshore structures requires depth capabilities in excess of those which are economical with divers (ie, 100 meters). Free-swimming, unmanned undersea vehicles operating in the supervisory-controlled mode (ie, man-in-the-loop) are being considered as a possible solution to the deep, undersea inspection problem. Specifically, an expendable optical fiber data link is proposed as a means to provide the wide-bandwidth, high-quality, bidirectional communications essential to advanced-sensor/real-time man-in-the-loop capabilities of such inspection vehicles. (Author).
Ocean Engineering Studies Compiled 1991. Volume 11. Pressure-Resistant Glass Light Enclosures ( Book )
1 edition published in 1991 in English and held by 2 libraries worldwide
Manned and unmanned diving systems require underwater lights for illumination to illuminate search and work areas. Electric light bulbs can neither tolerate the temperature shock resulting from immersion in cold water nor the pressure exerted by water at operational depth. They must be protected by transparent enclosures capable of withstanding the sudden immersion in cold water and long-term compression by external hydrostatic pressure. Low thermal conductivity of plastics, impedes heat dissipation from the interior of the plastic enclosure to the water. Only enclosures fabricated from borosilicate or pure silica glass with very low temperature expansion coefficient can satisfy operational requirements. The low coefficient of thermal expansion, coupled with high heat transfer capability, allows enclosures from this group of glasses to operate successfully with a very high temperature differential across the wall thickness. These glasses also possess compressive strength exceeding 200,000 psi. This property allows such enclosures to be constructed with very thin walls, thus further improving the heat transfer from the inside of these enclosures to the cold water outside. Testing involved establishing the critical pressure and cyclic fatigue life of glass enclosures due to (1) the effect of enclosure shape, (2) type of bulkhead, (3) the configuration of mating surfaces, and (4) gasket material used. Three types of glass enclosures were investigated: cylindrical domes with conical flanges, pipes with conical flanges, and tubes without flanges.
Acute Effects of (Bis)tributyltin Oxide on Marine Organisms. Summary of Work Performed 1981 to 1983 ( Book )
1 edition published in 1989 in English and held by 2 libraries worldwide
The acute effects of bis(tri-n-butyltin)oxide (TBTO) on six species of marine invertebrates were assessed to determine the relative toxicity of TBTO to a variety of organisms, and these results were compared with copper toxicity. Survival was the parameter measured for each species. Results indicated that TBTO was significantly more toxic than copper to all species by a factor of 10. In addition, organotin toxicity was roughly proportional to the number of butyl groups, i.e., monobutyltin less toxic than dibutyltin which was less toxic than tributyltin. The species tested fell into two categories: resistant and sensitive. The 96-hour LC50S ranged between 15 amd 30 parts per billion (ppb) TBTO for the reistant species, which included Protothaca staminea, Mytilus edulis, Citharichthys stigmaeus, and Neanthes arenaceodentata. The 96-hour LC50S ranged between 1- and 2-ppb TBTO for the sensitive species, which included Metamysidopis elongata and Acartia tonsa. Keywords: Antifouling coatings; Toxicity. (KT).
Marine Microcosm Experiments on Effects of Copper and Tributylin-Based Antifouling Paint Leachates ( Book )
1 edition published in 1988 in English and held by 2 libraries worldwide
A broad spectrum of marine plants and animals were excluded from flowthrough seawater microcosms by chronic exposures to TBTO (tributyltin) derived from antifouling paints. Rapid recovery of leachate-treated microcosms demonstrated that residual organotins were depurated quickly from sediments and/or had low toxicity. Community metabolic studies showed that the net impact on organic productivity of bottom-living harbor organisms would probably be minimal at sub-microgram/L TBTO concentrations. Gobiid fish and sea cucumbers experienced significant uptake of organotin-Sn over 2- to 3-month exposures to 0.8 microgram organotin-Sn/L. Sediments took up organotin-Sn at a nearly constant rate during a 3-month exposure to 0.8 microgram organotin-Sn/L, and rapidly released about 50 percent of absorbed tin in a 3-month depuration period. Two species of coral were found to be very sensitive indicators of total organotin concentrations. Toxic responses of corals indicated that, on a molar basis, TBTO-Sn was at least 10 times more toxic than copper. Keywords: Antifouling paint, Organotin paint leachates, Marine microcosms, Benthic organisms, Harbor pollutants, Tributyltin. (JES).
A Cognitive Model for Exposition of Human Deception and Counterdeception ( Book )
1 edition published in 1987 in English and held by 2 libraries worldwide
This report presents a theoretical tool and approach for understanding human deception and counterdeception in terms of cognitive processes and related principles of deception. A Cognitive Deception Model (CDM) is presented which is composed of 8 sections: Index, Structure, Characteristics, Principles, Examples, Plots, Tactical Objectives, and Tactics. The cognitive model structure and numbering system provide organization for the principles. The Cognitive Model on which the CDM is based is composed of components such as a central processor, attention mechanisms, memories, sensors, and affectors. A working Cognitive Simulation, included on a diskette, illustrates a computer modeling approach to studying human deception.
Analytical Procedures for Extractable Organotins in Soft Tissues of Marine Organisms ( Book )
1 edition published in 1987 in English and held by 2 libraries worldwide
A method for isolating extractable tributyltin and dibutyltin from soft tissues of marine organisms is presented. Analyses by graphite furnace atomic absorption spectrophotometry and by gas chromatography with both flame ionization detection and mass spectrometry are described. There has been increasing national and international concern about the effects of tributylins on the marine environment . Tributyltins (TBT) are introduced into the waterways predominantly from their use as antifouling agents in marine paints. These coatings, which release the biocide into the water column, are extensively used on commercial and recreational vessels and are proposed for use on naval ships in the near future. Due to toxic nature of TBT, there is an extreme need to assess its impact and fate in relation to non-target organisms. To evaluate the interactive roles of TBT and marine organisms, it is necessary to effectively isolate, identify, and quantify TBT and, at times, its alleged degradation products, di- and monobutyltins (DBT and MBT). The analytical procedures presented here are those currently used to quantify either (a) extractable TBT only, or (b) both TBT and DBT in various marine organisms. Because it is doubtful that any one method will be effective in all situations, development of the analytical procedures is an ongoing process. For this reason, it is stressed that the procedures presented here are (at the time of this writing) most effective for the samples encountered in this laboratory. The thorough (almost cookbook style) presentation is meant to inform the reader of the complete methods currently in use at NOSC and is by no means intended to be an analytical code or rule.
Marine Environmental Quality Assessment Program, Five-Year Plan (FY 1984-1988) ( Book )
1 edition published in 1984 in English and held by 2 libraries worldwide
This document is the second five-year plan (FY84-FY88) of the Marine Environmental Quality Assessment (MEQA) Program. It updates the MEQA Exploratory Development (FY78-FY83) Program Plan and places emphasis on current environmental issues, such as the fate and effects of organotin leachates, real-time monitoring techniques, bio-chemical analysis and advanced bioassay procedures. Keywords: Environmental program; Marine biology; Analytical chemistry; Organotin fate and effects; Real-time monitoring.
Remotely Manned Undersea Work Systems at Naval Ocean Systems Center (NOSC) ( Book )
1 edition published in 1978 in English and held by 2 libraries worldwide
The Remotely Manned Undersea Work Systems developed at the Naval Ocean Systems Center (NOSC) are herein described. This paper begins with a description and analysis of typical underwater work tasks. Based on the function derived from the tasks analysis, various underwater transporters (vehicles or divers systems) will be described; the sensors required to locate and provide support at the work site will be discussed. Based on the various components required to perform underwater tasks thus delineated, systems synthesis is applied to provide the most efficient operations by best combining the complementary characteristics of each of the subsystems. The tasks defined and equipment described are applicable to most undersea operations such as survey, inspection, search, salvage, recovery of items from the seafloor, emergency rescue of submersibles or habitats, as well as performance of dexterous tasks on undersea installations. (Author).
Test Procedures for Shipboard Transient Protective Devices (TPD's) ( Book )
1 edition published in 1979 in English and held by 2 libraries worldwide
The objective of this study was to develop the laboratory test procedures required to determine the effect of hf and vhf, shipboard-antenna transient protective devices (TPD), on the normal operational performance of hf and vhf communication systems. This is essentially a compatibility test-procedure development program. A significant portion of the energy released during a nuclear detonation appears as an electromagnetic pulse (EMP) having spectral components at the same frequencies as those employed by many military communication and other electronic systems. Protection of these systems against this potentially destructive and/or disruptive effect is required to ensure mission capability during and after a critical period. The objective of this report is to document how to determine that a protective device is compatible with system requirements and that it indeed does offer protection from a typical, high-level EMP. Requirements for transient protective devices and the text procedures and instrumentation recommended for determining the efficacy and system compatibility of selected TPD's for hf and uhf communications are listed and described. (Author).
Direct Execution Language Architecture for Simulation ( Book )
1 edition published in 1979 in English and held by 2 libraries worldwide
The study presented in this report addresses the application of direct execution computer architecture concepts using low-cost, large-scale-integration (LSI) to continuous system simulation. Basic architecture schemes for direct execution systems were investigated and applied to a demonstration interactive simulation language. A dual processor direct execution system was designed and built using an LSI-11 microcomputer, a 16K x 16 dual port memory, a microprogrammed AMD 2900 bit-slice direct execution processor, and a 16 x 16 multiplier chip. The system features a distinct separation of interpretive/compiler software and simulation run execution firmware linked via the dual port. The system is demonstrated via several simulation examples including realtime control, optimization, and torpedo dynamics problems. (Author).
Advanced Mail Systems Scanner Technology. Executive Summary and Appendixes A-D ( Book )
3 editions published between 1977 and 1979 in English and held by 1 library worldwide
The objective of the effort described herein is to provide technical consultation, equipment, and support services to the US Postal Service which will contribute to the development of the system definition of a new-concept processing system, the Electronic Message Service (EMS). Included in the scope of effort are investigations of highspeed image scanning technology, image frame memory storage, image enhancement, and the fabrication of a scanner/frame-store memory test assembly. The fourth annual report briefly describes the individual efforts of the reporting period in an executive summary and provides in-depth data in four appendixes: Advanced Illumination Correction; Document Data Base; Paper Reflectance as a Function of Data Density as Seen by a High-Resolution Reflectometer; and Image Capture and Analysis System-System Operator's Manual. (Author).
A General Theory for the Fusion of Data ( Book )
2 editions published between 1987 and 1991 in English and held by 1 library worldwide
The problem of data fusion is in a real sense the problem of how to model the real world with all of its great complexities. A miniaturized version of this is the multiple target tracking and data association problem. There, a number of pieces of information arrive, typically from disparate sources - such as from various sensing systems and from human sources in the form of narrative descriptions in natural language. A procedure has already been established for dealing with this type of situation, called succinctly the PACT algorithm. (PACT = Possibilistic Approach to Correlation and Tracking.) The technique is based upon the premise that all arriving information can be adequately treated through some appropriate choice of classical or multivalued logic such as Probability Logic, fuzzy Logic, Lukasiewicz - aleph1 Logic, or some (t-norm, t-conorm, negation function) general logic as discussed in a recent text of Goodman and Nguyen. Uncertainty Models for Knowledge-Based Systems. Moreover, it can be demonstrated that for a large class of logics chosen, a version of a partially specified Probability Logic may be used instead. Indeed, other approaches to uncertainty, such as the Dempster-Shafer approach, can also be strongly related to Probability Logic through the vehicle of random set modeling. In any case, the structure of the PACT algorithm is based upon a generalized chaining and disjunction relation, which in a classical probability setting reduces to the usual posterior probability description as a weighted sum of intermediate probabilities, an alternative form of Bayes' formulation.
Sea and Sky Infrared Radiances Near the Horizon ( Book )
2 editions published in 1989 in English and held by 1 library worldwide
Atmospheric infrared (8-12-microns)radiances over the ocean were measured from a shore station by using a calibrated thermal imaging system (AGA THERMOVISION Mod. 780). The Thermal Video Processor System (THERMOTEKNIX) available with the AGA allowed the mean equivalent blackbody temperatures corresponding to an area 1 deg above and 1 deg below the horizon in the scenes imaged to be determined during different meteorological and surface-wind-speed conditions. For this data set (18 thermograms), the mean sea temperatures differed the most from the mean cloud-free sky temperatures during low wind speed conditions. The differences were found to decrease with increasing wind speed. In contrast, the mean sea and sky temperatures measured during stratus cloud conditions were the same. The cloud-free data are used to evaluate background radiance algorithms, which must be used in the absence of radiometric measurements, to predict the performance of passive surveillance systems operating against airborne targets close to the horizon. Airborne measurements were made of the vertical profiles of metrological parameters and sea surface temperatures determined during 12 of the AGA measurements. From these measurements, LOWTRAN 6 calculations of the mean sky temperatures were found to be in close agreement with the measured values. Calculated mean sea temperatures showed slightly more variations than the measurements. These data are also used in a multiple regression analysis to derive an empirical relationship between the apparent mean sea and apparent mean sky temperatures which includes the measured wind speed and actual sea surface temperature. Infrared background; Optical propagation; Atmospheric physics.
Exploring the Back-Propagation Network for Speech Applications ( Book )
2 editions published in 1988 in English and held by 1 library worldwide
Neural networks have sophisticated abilities for processing and filtering signals. In particular, Elman and Zipser demonstrated that the back-propagation network develops significant feature representations which may be useful for both segmenting and recognizing speech. Such networks might find applications in speech compression and/or normalization. The network's apparent potential for speech applications justifies further exploration, and this paper describes our work in progress. Keywords: Neural networks, and Back-propagation. (rrh).
Combined Stimulus Control of Peak Frequency and Source Level in the Echolocating Dolphin (Tursiops truncatus) ( Book )
2 editions published between 1988 and 1989 in English and held by 1 library worldwide
Past echolocation research demonstrated control over the dolphin's echolocation emissions in a binary (on/off) condition. The dolphin performed a discrimination task while its echolocation output was under stimulus control of an underwater tone. The animal learned to echolocate during the presence of the tone and to remain silent if no tone was given. Mackay used two Atlantic bottlenose dolphin (Tursiops truncatus) to determine the dolphin's capability to control whistle emissions in the 5-16 kHz range. Using automatic feeders activated by specific frequency ranges, Mackay showed that dolphins could control the frequency of their whistles. Recent research revealed behavioral control can also be obtained over the source level of the echolocating dolphin. Moore and Patterson trained a dolphin to perform a detection task while under operant control of its emitted source levels. Dolphin clicks are short duration (10 to 100 microsec) wide band transients. It is thought that the target, to a large extent, dictates the click emission parameters of frequency and amplitude. Past research shows that dolphins control the repetition rate of emitted clicks as a function of target range, but the capability of the dolphin to independently control both the frequency and source level of their clicks has never been demonstrated. Presented at 15th Annual Conference of the International Marine Animal Trainers Association, 26-30 October 1987, New Orleans, Louisiana. Keywords: Marine biosystems; Marine biology. (kt).
The New MININEC (Version 3). A Mini-Numerical Electromagnetic Code ( Book )
2 editions published between 1986 and 1987 in English and held by 1 library worldwide
MININEC is a method of moments computer program for the analysis of thin wire antenna problems. MININEC uses a Galerkin procedure to solve for the wire currents using an integral equation formulation that relates the electric field and the vector and scalar potentials. This approach results in a compact computer code suitable for use on a microcomputer. MININEC solves for the impedance and currents on arbitrarily oriented wires including configurations with multiple wire junctions. Optics include lumped impedance loading, near electric and near magnetic fields, and far field patterns for free space or perfectly conducting ground. MININEC is written in the BASIC language compatible with IBM PC DOS. Keywords: Method of moments; Computer programs; Galerkin procedure; Thin wire antennas; Numerical Electromagnetics Code.
Comparison of the Wall Pressure Fluctuations in Artificially Generated Turbulent Spots, Natural Transition and Turbulent Boundary Layers ( Book )
2 editions published between 1985 and 1988 in English and held by 1 library worldwide
Knowledge of the wall pressure fluctuations beneath transitional and turbulent flows is required in order to understand and reduce aerodynamically and hydrodynamically generated noise. Measurements inside and outside turbulent boundary layers indicate that the wall pressure fluctuations generated by turbulence may well be the dominant mechanism in the generation of near field noise (self-noise) and, if the wall pressure fluctuations are coupled with the vibratory modes of the structure, there will be a significant increase in the sound level radiated into the far field. Wall pressure fluctuations were measured in the plane of symmetry of turbulent spots convecting in a laminar boundary layer having zero, favorable and adverse pressure gradients. The results show that the magnitude of the rms(root mean square) wall pressure and the spectra of the turbulent spot phase of boundary layer transition are strongly influenced by the local mean flow pressure gradient. The data also verifies that boundary layer transition in the presence of an adverse pressure gradient produces rms wall pressure fluctuations which are 1.5-2.5 times larger than those found in either a zero or favorable pressure gradient. Keywords: Acoustic efficiency, Wall pressure fluctuations; Turbulent boundary layers; Artificially generated turbulent spots.
Advanced Mail Systems Scanner Technology. Executive Summary and Appendixes A-E ( Book )
2 editions published between 1980 and 1982 in English and held by 1 library worldwide
The objective of the effort described herein is to provide technical consultation, equipment, and support services to the US Postal Service that will contribute to the development of the system definition of future electronic mail processing systems. Included in the scope effort are investigations of high-speed image scanning technology, image frame memory storage, and image enhancement as well as fabrication of a scanner/frame-store memory test assembly. The seventh annual report briefly describes the individual efforts of the reporting period in an executive summary and provides in-depth data in five appendixes: Appenix A, Memory Technology Assessment; Appendix B, Image Acquisition Studies; Appendix C, DOD Facsimile Data Compression Standard with First Annual Report, Advanced Mail Systems Scanner Technology, NOSC Technical Report NELC TR 1965, 22 October 1975, DTIC AD A020175.
Aircraft Fiber-Optic Interconnect Systems Project ( Book )
2 editions published between 1979 and 1980 in English and held by 1 library worldwide
This report summarizes the development and fabrication of a fiber-optic interconnect intended for use in a MIL-STD-1553 multiplex system. (Author).
Security Considerations for Autonomous Robots ( Book )
2 editions published between 1988 and 1990 in English and held by 1 library worldwide
The security aspects of autonomous robots are analyzed by modeling a robot as a set of sensors, effectors, optional communications resources, and processing elements whose behavior is tightly coupled to be sensed characteristics of its environment. A simple taxonomy of potential generic threat types is presented, comprising both the possible direct external threat paths and the derived consequent internal threat states. Several generic countermeasure strategies are proposed.