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IEEE conference on Aerospace

作者： Fred Roe Kevin Betts Connie Carrington Advanced Optical Systems Inc. Huntsville AL USA A Subsidiary of SAIC Bd Systems Inc. Huntsville AL USA EV21 NASA Marshall Space Flight Center Huntsville AL USA

U.S. technology to support the Crew Exploration Vehicle (CEV) rendezvous and docking operations was developed by NASA and supporting industry during an extensive research and development program conducted during the 1990's and early 2000 time frame at the Marshall Space Flight Center. Development and demonstration of a rendezvous/docking sensor was identified early in NASA's AR&D Program as the critical enabling technology that allows automated proximity operations and docking. A first generation rendezvous/docking sensor, the Video Guidance Sensor (VGS), was developed and successfully flown on STS 87 and again on STS 95, proving the concept of a video-based sensor. advances in both video and signal processing technologies and the lessons learned from the two successful flight experiments provided a baseline for the development of a new generation of video based rendezvous/docking sensors. The Advanced Video Guidance Sensor (A VGS) has greatly increased performance and additional capability for longer-range operation. A Demonstration Automatic Rendezvous technology (DART) flight experiment was flown in April 2005 using AVGS as the primary proximity operations sensor. Because of the absence of a docking mechanism on the target satellite, this mission did not demonstrate the ability of the sensor to control docking. Mission results indicate that the rendezvous sensor operated successfully in "spot mode" (2 km acquisition of the target, bearing data only) but was never commanded to "acquire and track" the docking target.

关键词： Sensor systems Space technology Sociotechnical systems Space vehicles NASA Aerospace industry Research and development Video signal processing Signal generators Satellites

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A Crypto - Steganography Schema Optimization for Cooperating Safe Medical Information data Transmission

A Crypto - Steganography Schema Optimization for Cooperating...

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advances in Modern Age Technologies for Health and Engineering Science (AMATHE), International conference on

作者： Marwa Mahdi Kareem Adnan Hussein Ali Bayan Mahdi Sabbar Raed Khalid Ibrahim Mohammed Mahdi Hashim Mohannad Jabbar Mnati Middle Technical University Technical Management Institute Baghdad Iraq Electrical Techniques Department Institute of Technology Middle Technical University Baghdad Iraq College of Engineering and Engineering Technologies AlMustaqbal University Department of Medical Instruments Engineering Techniques Al-Farahidi University Baghdad Iraq Studies Planning and Follow-up Directorate Ministry of Higher Education and Scientific Research Baghdad Iraq

ISBN: (数字)9798350371567

ISBN: (纸本)9798350371574

An improved image steganography method is introduced in this study, with the intention of enhancing three critical criteria: high capacity, security, and imperceptibility. The proposed method evaluates the performance of a novel concealing technique that is utilized to obscure secret communications within trusted images in comparison to established benchmarks. Furthermore, the research paper presents an Inverting Map method (IMM) that has been specifically developed to optimize Peak Signal-to-Noise Ratio (PSNR) and increase storage capacity, thereby preserving the integrity of the images. In addition, security is improved through the incorporation of random and Henon map algorithms, which increase the complexity and selection of pixels, thus fortifying the system against potential assaults. The cover image's dynamic characteristics, in conjunction with adaptive pixel modifications, guarantee resilience against a multitude of attack vectors. The study establishes the efficacy of the proposed method in attaining high capacity, security, and imperceptibility for image steganography applications via exhaustive experimentation and evaluation.

关键词： Image quality Steganography PSNR Heuristic algorithms Memory Vectors Complexity theory

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Building damage detection from post-earthquake aerial imagery using building grey-value and gradient orientation analyses

Building damage detection from post-earthquake aerial imager...

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International conference on Recent advances in Space Technologies (RAST)

作者： E. Sumer M. Turker Department of Computer Engineering Baskent University Ankara Turkey Graduate School of Natural and Applied Sciences Geodetic and Geographic Information Technologies Middle East Technical University Ankara Turkey

The collapsed buildings due to 1999 Kocaeli earthquake were detected from post-event panchromatic aerial imagery based on grey-value and the gradient orientation of the buildings. The building boundaries were available and stored in a GIS as vector polygons. The building polygons were utilized to perform the assessments in a building specific manner. The approach was implemented in a selected area of Golcuk, which is one of the urban areas most strongly hit by the earthquake. First, the buildings were selected one-by-one from the integrated vector (building boundaries) and raster (aerial photo) data set. The building damage detection process was then divided into two branches. In the first branch, the detection was performed using the building grey-value information. To do that, a greyvalue threshold (T1) was determined for discriminating the collapsed buildings from the un-collapsed ones. In the second branch, a group of operations including the gradient calculation and the determination of gradient orientation were performed. By utilizing the orientation information, an optimum threshold level (T2) was determined for the standard deviation of the angle distribution of the building pixels. When assessing the condition of a building, the results of the two branches were combined and a final decision was made in an integrated manner. Of the 284 buildings analyzed, 254 were labeled correctly as collapsed or un-collapsed providing an overall accuracy of 89.44%. The results reveal that the collapsed buildings due to the earthquake can be successfully detected from post-event aerial images.

关键词： Image analysis Remote monitoring Remote sensing Laser radar Space technology optical sensors Spaceborne radar Earthquake engineering Urban areas Resource management

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New technologies for fluid dynamics experiments and optical diagnostics

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PHYSICA SCRIPTA 2008年第T132期T132卷 014056-014056页

作者： Orlov, Sergei S. Stanford Univ Dept Elect Engn Stanford CA 94305 USA

Modern technologies offer new opportunities for experimentalists in a wide variety of research areas including hydrodynamics. A significant improvement in precision, dynamic range, reproducibility, motion control accuracy, data acquisition rate and information capacity of the experimental datasets over the current state-of-the-art are possible using new approaches and techniques, which may bring the quality of experiments to a new level of standards. Application of these new technologies in experimental diagnostics can help bridge the current quality gap between the observations and the large-scale computational fluid dynamics simulations allowing direct and unambiguous comparison of the data and the modeling results, which is crucial for the code validation. One of the new technologies which is described in this paper is ultra-high performance digital holographic data storage. The state-of-the-art motion control, electronics and optical imaging allow for realization of turbulent flows with very high Reynolds number (>10(7)) in a relatively small laboratory-scale form-factor and quantification of their properties with extremely high spatio-temporal resolutions and bandwidth. Digital holographic technology can provide complete three-dimensional mapping of the flow velocity and density fields at high data rates (over 1000 fps) over large spatial area (similar to 50 cm) with high spatial (1-10 mu m) and temporal (better than a few nanoseconds) resolutions and, therefore, can provide extremely accurate quantitative description of the fluid flows, including those of multiphase and unsteady conditions. These unique experimental and metrological capabilities enable the studies of spatial and temporal properties of the transport of momentum, angular momentum and energy, and the identification of scaling, invariants and statistical properties of the complex multiphase and unsteady turbulent flows. The technology can be applied for investigations of a large variety of hydrody

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MultiHGR: Multi-Task Hand Gesture Recognition with Cross-Modal Wrist-Worn Devices

MultiHGR: Multi-Task Hand Gesture Recognition with Cross-Mod...

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IEEE Annual Joint conference: INFOCOM, IEEE Computer and Communications Societies

作者： Mengxia Lyu Hao Zhou Kaiwen Guo Wangqiu Zhou Xingfa Shen Yu Gu LINKE Lab School of Computer Science and Technology University of Science and Technology of China CAS Key Laboratory of Wireless-Optical Communications University of Science and Technology of China Deqing Alpha Innovation Institute Huzhou China Hangzhou Dianzi University China University of Electronic Science and Technology of China China

ISBN: (数字)9798350383508

ISBN: (纸本)9798350383515

Hand gesture recognition (HGR) is essential for human-machine interaction. Although the existing solutions achieve good performance in specific tasks, they still face challenges when users navigate through different application contexts, i.e., demanding multi-task ability to support newly arrived HGR tasks. In this paper, we propose the first IMU-vision based system hosted on wrist-worn devices to support multi-task HGR, denoted as MultiHGR. The system introduces a novel two-stage training strategy, i.e., task-agnostic stage to align cross-modal features from unlabeled arbitrary gesture through contrastive learning, and task-related stage to learn modality contributions with limited labeled data in specific tasks through self-attention mechanism. Since only the second task-related stage should be executed for each new task, MultiHGR could accommodate multiple tasks with significant reduced training cost and storage requirement. The evaluation results on three HGR tasks demonstrates that MultiHGR reduces 64.92% training time, and 24.04% storage as compared with traditional multimodal single-task models, and MultiHGR outperforms unimodal single-task models with 14.37%, 19.28%, and 31% improvements in these three tasks, respectively. As compared with state-of-the-art multimodal single-task model, MultiHGR achieves average 6.35% accuracy improvement, along with 65.74% training time reduction.

关键词： Training Performance evaluation Human computer interaction Navigation Gesture recognition Contrastive learning Multitasking

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Benefits of LRU-centric fibre channel testing

Benefits of LRU-centric fibre channel testing

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International Automatic Testing conference, AUTOTESTCON

作者： Yonet A. Eracar Teradyne Inc. North Reading MA USA

Fibre channel is a highly reliable, gigabit, serial interconnect technology. Commercial applications of the fibre channel technology allow concurrent communications among storage devices using upper level protocols such as small computer system interface (SCSI) and internet protocol (IP). Fibre channel technology is scalable and flexible due to its support of various topologies, such as dedicated point-to-point, arbitrated loops, and scaled switched networks. Advanced avionics programs and applications have an increasing need for bandwidth while maintaining low latency, determinism, and reliability. Therefore fibre channel is being selected as an avionics communication solution for a variety of new military aircraft and upgrades to existing aircraft. Testing at all stages (factories and depots) is necessary to guarantee the reliable and deterministic communication of avionics. Fibre Channel avionics networks present new challenges to those responsible for maintenance testing at the depots: 1. the requirement of testing an avionics application communicating via an upper level protocol, while the test environment presents a low level, physical interface. 2. Emulating the system environment of a line replaceable unit (LRU) to obtain complete functional test coverage. 3. Storing and monitoring large amounts of data passing through the fibre channel network. Existing test instruments and emulators in the market operate at the fibre channel protocol level and they lack necessary support for LRUs. Testing at the fibre channel protocol level detects bad receivers, transmitters, media, and fibre channel processors, but fails to find problems in the inner workings of an LRU. In this paper, we will address the testing challenges listed above with an LRU-centric approach. We will specify an LRU-centric fibre channel testing framework and provide implementation guidelines using example applications.

关键词： optical fiber testing optical fiber communication Aerospace electronics Protocols optical fiber devices Application software Maintenance Telecommunication network reliability Military aircraft Communications technology

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Study of the crystallographic texture and interface roughness on CoCrPt/Ti magnetic thin film using x-ray scattering and x-ray reflectivity

Study of the crystallographic texture and interface roughnes...

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International conference on Magnetics (INTERMAG)

作者： C.J. Sun G.M. Chow J.P. Wang E.W. Soo J.H. Je Dept. of Materials Science National University of Singapore Singapore Data Storage Institute Kent Ridge Singapore Pohang University of Science and Technology Pohang South Korea

Summary form only given. CoCrPt films with Ti underlayer have been widely investigated as candidate media for perpendicular recording. The growth of Co alloy is interfacially controlled by the Ti underlayer. Although the engineering effects of Ti underlayer with magnetic properties of CoCrPt film are known, a combined understanding of the effects of crystallographic texture and interface roughness of CoCrPt/Ti films on magnetic properties is yet unclear. In this work, Co/sub 74/Cr/sub 16/Pt/sub 10//Ti films were deposited using DC magnetron sputtering and examined by x-ray scattering and x-ray reflectivity.

关键词： Crystallography Magnetic films X-ray scattering Reflectivity optical films Perpendicular magnetic recording Magnetic properties Cobalt alloys Titanium alloys Chromium

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Collaborative Intelligence in optical/IR Camera Based Wireless Sensor Nodes for HVAC Control

Collaborative Intelligence in Optical/IR Camera Based Wirele...

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IEEE Sensors conference

作者： Ningyuan Cao Shreyas Sen Arijit Raychowdhury LCL Georgia Institute of Technology Atlanta GA ECE Purdue University West Lafayette IN

ISBN: (纸本)9781509010134

Heating, ventilation and cooling (HVAC) consumes nearly 50% of electrical energy spent in homes and offices world-wide. To adapt an HVAC system to the dynamic environment and save energy without compromising the comfort level of the occupants, different techniques have been explored to sense the real-time occupancy in rooms, zones and buildings. Among all these approaches, wireless camera-based sensing is appealing for its intrinsic application potentials in surveillance and security besides energy management. However, limited life-time and detection accuracy, due to embedded energy storage and computation capability constraints, have prevented pervasiveness of wireless camera-based occupancy detection. This paper presents a novel wireless device platform and prototype development that incorporates IR camera with optical camera to provide collaborative intelligence at low-power and high-accuracy. Compared to an optical camera based baseline design, we demonstrate 65× improvement in miss rate, 5× reduction in detection false positive rate and 25% lifetime extension for battery usage;and a maximum of 40% HVAC energy savings compared to thermostat based control.

关键词： energy saving HVAC data-fusion occupancy detection

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Planar Diffractive Lenses: Fundamentals, Functionalities, and Applications

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ADVANCED MATERIALS 2018年第26期30卷 1704556-1704556页

作者： Huang, Kun Qin, Fei Liu, Hong Ye, Huapeng Qiu, Cheng-Wei Hong, Minghui Luk'yanchuk, Boris Teng, Jinghua ASTAR Inst Mat Res & Engn 2 Fusionopolis WayInnovis 08-03 Singapore 138634 Singapore Univ Sci & Technol China Dept Opt & Opt Engn Hefei 230026 Anhui Peoples R China Jinan Univ Inst Photon Technol Guangdong Prov Key Lab Opt Fiber Sensing & Commun 601 Huangpu Ave West Guangzhou 510632 Guangdong Peoples R China Natl Univ Singapore Dept Elect & Comp Engn 4 Engn Dr 3 Singapore 117576 Singapore ASTAR Data Storage Inst 2 Fusionopolis WayInnovis 08-01 Singapore 138634 Singapore Nanyang Technol Univ Sch Phys & Math Sci Div Phys & Appl Phys Singapore 637371 Singapore Lomonosov Moscow State Univ Fac Phys Moscow 119991 Russia

Traditional objective lenses in modern microscopy, based on the refraction of light, are restricted by the Rayleigh diffraction limit. The existing methods to overcome this limit can be categorized into near-field (e.g., scanning near-field optical microscopy, superlens, microsphere lens) and far-field (e.g., stimulated emission depletion microscopy, photoactivated localization microscopy, stochastic optical reconstruction microscopy) approaches. However, they either operate in the challenging near-field mode or there is the need to label samples in biology. Recently, through manipulation of the diffraction of light with binary masks or gradient metasurfaces, some miniaturized and planar lenses have been reported with intriguing functionalities such as ultrahigh numerical aperture, large depth of focus, and subdiffraction-limit focusing in far-field, which provides a viable solution for the label-free superresolution imaging. Here, the recent advances in planar diffractive lenses (PDLs) are reviewed from a united theoretical account on diffraction-based focusing optics, and the underlying physics of nanofocusing via constructive or destructive interference is revealed. Various approaches of realizing PDLs are introduced in terms of their unique performances and interpreted by using optical aberration theory. Furthermore, a detailed tutorial about applying these planar lenses in nanoimaging is provided, followed by an outlook regarding future development toward practical applications.

关键词： flat optics metasurfaces subdiffraction limit superresolution imaging zone plates

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Filter-based PV power smoothing control for island hybrid energy systems with high PV penetration

Filter-based PV power smoothing control for island hybrid en...

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IEEE International conference on Automation Science and Engineering (CASE)

作者： Julia Sachs Bertram Müller Kevin Tom Oliver Sawodny Department Institute for System Dynamics University of Stuttgart Stuttgart Germany Research and Technology Center of the Robert Bosch GmbH Singapore Singapore

ISBN: (纸本)9781479952847

Hybrid energy system are a promising option considering low cost energy supply. The integration of renewable sources to diesel only systems allows for a reduction in diesel generator fuel consumption. However, significant issues with renewable power systems are their intermittency and unpredictability. This influence can be limited by an improved energy management strategy. State of the art strategies, which claim a low energy cost, are based on averaged photovoltaic (PV) data. Applying these methods to systems using real PV data results in an inefficient operation of the diesel generator and increased cost. In this paper, a new control strategy for the operation of diesel generators in systems with high (> 70%) PV penetration is proposed. This new operational strategy is based on a filter-based control, including a Kalman or Particle filter and a small storage to undertake the standby capacity of the diesel generator. Based on the filtered photovoltaic data, an optimal operating point for the diesel generator is identified. Simulation analysis using the load profile of a cargo complex shows that this method significantly improves the diesel generator operation by 50% reduction in cold starts compared to conventional hybrid energy management strategies. The proposed strategy also achieves up to 7% savings in cost of energy with high PV penetration.

关键词： optical filters Computer aided software engineering Atmospheric measurements Particle measurements

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