Showing papers on "Night vision published in 2013"

The nocturnal bottleneck and the evolution of activity patterns in mammals

Abstract: In 1942, Walls described the concept of a 'nocturnal bottleneck' in placental mammals, where these species could survive only by avoiding daytime activity during times in which dinosaurs were the dominant taxon. Walls based this concept of a longer episode of nocturnality in early eutherian mammals by comparing the visual systems of reptiles, birds and all three extant taxa of the mammalian lineage, namely the monotremes, marsupials (now included in the metatherians) and placentals (included in the eutherians). This review describes the status of what has become known as the nocturnal bottleneck hypothesis, giving an overview of the chronobiological patterns of activity. We review the ecological plausibility that the activity patterns of (early) eutherian mammals were restricted to the night, based on arguments relating to endothermia, energy balance, foraging and predation, taking into account recent palaeontological information. We also assess genes, relating to light detection (visual and non-visual systems) and the photolyase DNA protection system that were lost in the eutherian mammalian lineage. Our conclusion presently is that arguments in favour of the nocturnal bottleneck hypothesis in eutherians prevail.

NIR-sensitive poly(3,4-ethylenedioxyselenophene) derivatives for transparent photo-thermo-electric converters.

Abstract: Electrochromism, photothermal effect, and thermoelectric properties of hexyl-derivatized poly(3,4-ethylenedioxyselenophene) are investigated by precisely controlling the morphology. These properties are clearly demonstrated by controlling the applied electrical potential of the polymer films. Especially, the doped polymer film at -0.1 V reveals the highest photothermal conversion efficiency and a power factor of 42.5% and 354.7 μW m(-1) K(-2) , respectively. Efficient visible to near-infrared absorption, photon to heat, and heat to electric conversion has been realized in one film that could benefit in exploiting multifunctional film displays, invisible NIR sensors, photodynamic theragnosis, and thermoelectric devices.

Coaxially sighted corneal light reflex versus entrance pupil center centration of moderate to high hyperopic corneal ablations in eyes with small and large angle kappa.

Abstract: Purpose To determine whether centering ablations on the coaxially sighted corneal light reflex (CSCLR) in eyes with large angle kappa leads to poor visual outcomes when compared to patients with eyes with negligible angle kappa that by default would be centered on the entrance pupil. In eyes with no angle kappa, the CSCLR coincides with the entrance pupil center, whereas eyes with large angle kappa possess an offset between the CSCLR and the entrance pupil center. Methods This study was a retrospective case series of consecutive patients treated by hyperopic LASIK using the MEL80 excimer laser (Carl Zeiss Meditec, Jena, Germany). All ablations were centered on the CSCLR using the standard non-wavefront-guided ablation profile. Angle kappa was classified according to pupil offset defined as the distance in the corneal plane between the entrance pupil center and the corneal vertex. Eyes were divided into two discrete groups according to the pupil offset: small angle kappa for pupil offset of 0.25 mm or less (n = 30) and large angle kappa for pupil offset of 0.55 mm or greater (n = 30). Safety, accuracy, cylinder vector analysis, contrast sensitivity, vertex centered corneal aberrations, entrance pupil centered whole eye aberrometry, and night vision disturbances were compared between the two groups. Results There were no statistically significant differences in safety, accuracy, induced astigmatism, contrast sensitivity, or night vision disturbances between the two groups. There was also no statistically significant difference between groups for vertex centered corneal aberrations; however, as expected, coma was higher in the large angle kappa group for entrance pupil centered aberrometry because the treatment had been centered on the CSCLR rather than the entrance pupil center. Conclusion Refractive outcomes of high hyperopic LASIK were not found to be worse for eyes where ablation was centered more than 0.55 mm from the entrance pupil as determined by CSCLR in eyes with large angle kappa. The absence of poor quality visual outcomes in cases, which by entrance pupil centration are considered significantly "decentered," supports the notion that centration relative to the CSCLR may be preferable. This provides evidence that refractive corneal ablation should not be systematically aligned with the entrance pupil center.

Review of night vision technology

Abstract: Night vision based on technology of image intensifier tubes is the oldest electro-optical surveillance technology. However, it receives much less attention from international scientific community than thermal imagers or visible/NIR imagers due to series of reasons. This paper presents a review of a modern night vision technology and can help readers to understand sophisticated situation on the international night vision market.

Functional allocation of synaptic contacts in microcircuits from rods via rod bipolar to AII amacrine cells in the mouse retina.

Abstract: Retinal microcircuits for night vision at the absolute threshold are required to relay a single-photon rod signal reliably to ganglion cells via rod bipolar (RB) cells and AII amacrine cells. To assess the noise reduction of intercellular signal transmission in this rod-specific pathway, we quantified its synaptic connectivity by 3D reconstruction of a series of electron micrographs. In most cases (94%), each rod made ribbon synaptic contacts onto two adjacent RB cells. Conversely, each RB cell was contacted by 25 rods. Each RB axon terminal contacted four or five AII amacrine cells via 53 ribbon synapses. Thus, the signal from one rod may be represented as 106 replicates at two RB axons. Moreover, the two adjacent RB cells contacted two to four AII amacrine cells in common, where the signals relayed by two RB cells were reunited. In more detail, over 50% of each RB output was directed predominantly to a single, preferred AII amacrine cell, although each RB cell also separately contacted another one to three AII amacrine cells. Most of the replicate signals at two RB axons were collected on a few AII amacrine cells via reunions, dominant connections, and electrical coupling by AII–AII gap junctions. Thus the original signal may be reliably represented by signal amplification with focal accumulation without gathering unnecessary noise from a wide surrounding area. This allocation of RB–AII synaptic contacts may serve as the structural basis for the physiological properties of the AII single-photon response that include high amplification, local adaptation, and regenerative acceleration. J. Comp. Neurol. 521:3541-3555, 2013. © 2013 Wiley Periodicals, Inc.

Subjective satisfaction in long-term orthokeratology patients.

Abstract: Purpose:To evaluate the subjective satisfaction in visual stability, night vision complains, and light distortion phenomena, and also the number of hours and days per week of lens wear, in patients with myopia undergoing orthokeratology (OK) treatment for at least 1 year.Methods:A visual analog scal

A Thermal Facial Emotion Database and Its Analysis

Abstract: In recent years, thermal image has extensively been used in many fields such as military (e.g., target acquisition, surveillance, night vision, homing and tracking) and civilian purposes (e.g., medical diagnosis, thermal efficiency analysis, environmental monitoring). It may be a promising alternative for investigation of facial expression and emotion. Currently there are very few database to support the research in facial expression and emotion, however most of them either only include posed thermal expression images or lack thermal information. For these reasons, we propose and establish a natural visible and thermal facial emotion database. The database contains seven spontaneous emotions of 26 subjects. We also analyze a visible database, a thermal database to recognize expression and thermal information to recognize emotion.

Head-up display for night vision goggles

Abstract: A head-up display system for a vehicle facilitating the use of night vision goggles for a person in the vehicle during night vision conditions, the system comprising a light source for providing light to an image source, which image source is arranged to project an image on a semi-transparent combiner mirror; the combiner mirror being arranged to superimpose the projected image onto a view of the environment in front of the vehicle by transmitting light rays from the environment and at the same time reflecting the projected image towards the eyes of an observer wherein the system comprises a first and a second light source for alternatively providing light to the image source; the first light source being arranged to emit light of a first colour to be used during daylight conditions, and the second light source being arranged to emit light of a second colour to be used during night vision conditions, wherein the first colour is in a first light emission spectrum and perceived as green and the second colour is in a second emission spectrum and perceived as yellow or orange.

Pupil size and LASIK: a review.

Abstract: Purpose To provide a literature review on the evidence both for and against pupil size as an independent predictor of adverse visual outcomes after LASIK. Methods Peer-reviewed publications on the effect of pupil size on LASIK outcomes since 2002 are reviewed. Particular attention was paid to the following attributes of each publication: type of study, number of patients or eyes, mean age, mean level of myopia, mean pupil size, testing conditions, ablation zone diameter, presence or absence of blend zones, and mean follow-up period. Results Among the 19 studies examined, none correlates a persistent relationship between pupil size and night vision complaints (NVCs) beyond 3 months when LASIK was performed with a 6.0-mm optical zone or larger ablation. The studies that did explicitly determine a correlation either included some or all patients with ablation zones smaller than 6.0 mm or did not specify ablation diameter at all. Among the studies that had drawn more mixed conclusions, the studies either covered short follow-up intervals (1 to 3 months) or showed a progressive improvement in NVCs over time in a relatively small patient cohort. Conclusions As keratorefractive technology continues to evolve, the role of pupil size warrants further investigation; however, based on the literature reviewed herein, modern LASIK has negated the role of the low light pupil in predicting adverse visual outcomes after LASIK outside of the early postoperative period.

Virtual war and magical death : technologies and imaginaries for terror and killing

Abstract: Acknowledgments ix Introduction: Virtual War and Magical Death / Neil L. Whitehead and Sverker Finnstrom 1 1. Ethnography, Knowledge, Torture, and Silence / Neil L. Whitehead 26 2. The Role of Culture in Wars Waged by Robots: Connecting Drones, Anthropology, and Human Terrain System's Prehistory / David Price 46 3. Cybernetic Crystal Ball: "Forecasting" Insurgency in Iraq and Afghanistan / Roberto J. Gonzalez 65 4. Full Spectrum: The Military Invasion of Anthropology / R. Brian Ferguson 85 5. Today He Is No More: Magic, Intervention, and Global War in Uganda / Sverker Finnstrom 111 6. The Hostile Gaze: Night Vision and the Immediation of Nocturnal Combat in Vietnam and Iraq / Antonius C. G. M. Robben 132 7. Virtual Soldiers, Cognitive Laborers / Robertson Allen 152 8. Virtual Wars in the Tribal Zone: Air Strikes, Drones, Civilian Casualties, and Losing Hearts and Minds in Afghanistan and Pakistan / Jeffrey A. Sluka 171 9. Propaganda, Gangs, and Social Cleansing in Guatemala / Victoria Sanford 194 10. The Soundtrack to War / Matthew Sumera 214 11. War at Large: Miner Magic and the Carrion System / Koen Stroeken 234 References 251 Contributors 279 Index 281

Assessment of night vision problems in patients with congenital stationary night blindness.

Abstract: Congenital Stationary Night Blindness (CSNB) is a retinal disorder caused by a signal transmission defect between photoreceptors and bipolar cells. CSNB can be subdivided in CSNB2 (rod signal transmission reduced) and CSNB1 (rod signal transmission absent). The present study is the first in which night vision problems are assessed in CSNB patients in a systematic way, with the purpose of improving rehabilitation for these patients. We assessed the night vision problems of 13 CSNB2 patients and 9 CSNB1 patients by means of a questionnaire on low luminance situations. We furthermore investigated their dark adapted visual functions by the Goldmann Weekers dark adaptation curve, a dark adapted static visual field, and a two-dimensional version of the “Light Lab”. In the latter test, a digital image of a living room with objects was projected on a screen. While increasing the luminance of the image, we asked the patients to report on detection and recognition of objects. The questionnaire showed that the CSNB2 patients hardly experienced any night vision problems, while all CSNB1 patients experienced some problems although they generally did not describe them as severe. The three scotopic tests showed minimally to moderately decreased dark adapted visual functions in the CSNB2 patients, with differences between patients. In contrast, the dark adapted visual functions of the CSNB1 patients were more severely affected, but showed almost no differences between patients. The results from the “2D Light Lab” showed that all CSNB1 patients were blind at low intensities (equal to starlight), but quickly regained vision at higher intensities (full moonlight). Just above their dark adapted thresholds both CSNB1 and CSNB2 patients had normal visual fields. From the results we conclude that night vision problems in CSNB, in contrast to what the name suggests, are not conspicuous and generally not disabling.

Methods and systems for measuring dynamic changes in the physiological parameters of a subject

Abstract: Methods for remotely measuring or monitoring one or more physiological parameters in a subject, such as blood volume pulse, heart rate, respiratory wave, or respiration rate, are provided. The methods include capturing a series of images of the subject, and processing the images to obtain physiological parameters of interest. These methods can be used to analyze single channel signals, including signals obtained from active night vision cameras. As a result, these methods can be used to measure or monitor one or more physiological parameters in both daylight and low-light conditions. Also provided are methods of removing false positives. Systems for remotely measuring or monitoring one or more physiological parameters in a subject, as well as methods of using thereof, are also provided.

Development of a headlight glare simulator for a driving simulator

Abstract: We describe the design and construction of a headlight glare simulator to be used with a driving simulator. The system combines a modified programmable off-the-shelf LED display board and a beamsplitter so that the LED lights, representing the headlights of oncoming cars, are superimposed over the driving simulator headlight images. Ideal spatial arrangement of optical components to avoid misalignments of the superimposed images is hard to achieve in practice, and variations inevitably introduce some parallax. Furthermore, driver’s viewing position varies with driver height and seating position preferences, exacerbating misalignment. We reduce the parallax errors using an intuitive calibration procedure (a simple drag-and-drop alignment of nine LED positions with calibration dots on the screen). To simulate the dynamics of headlight brightness changes when two vehicles are approaching, LED intensity control algorithms based on both headlight and LED beam shapes were developed. The simulation errors were estimated and compared favorably with real-world headlight brightness variability.

Induction type non-contact charging locating aligning device and locating method thereof

Abstract: The invention discloses an induction type non-contact charging locating aligning device which comprises a rough aligning device, a vehicle-mounted electric energy receiving device, a ground electric energy emitting device, an ultrasonic wave accurate positioning system and an ultrasonic wave locating processing module. The rough aligning device comprises a front vehicle-mounted night vision camera, a rear vehicle-mounted night vision camera, a rearview mirror type display screen, a front ground identifier and a rear ground identifier. The ultrasonic wave accurate positioning system comprises an ultrasonic wave emitting sensor, an ultrasonic wave receiving sensor A, an ultrasonic wave receiving sensor B, an ultrasonic wave receiving sensor C, an ultrasonic wave receiving sensor D, a stepping motor A, a stepping motor B, a moving platform and a temperature sensor. The ultrasonic wave locating processing module comprises a vehicle-mounted processing module and a ground processing module. An induction type non-contact charging locating method comprises the steps that firstly, a driver completes rough location through images; secondly, an ultrasonic wave locating system is started; thirdly, the moving platform is aligned on the basis of position calculation.

Acceptability of rider assistive systems for powered two-wheelers

Abstract: There has been limited development of advanced rider assistance systems and on-bike information systems for powered two-wheelers (PTWs), even though research suggests that population-wide deployment of assistive systems could significantly reduce PTW crashes. This study aims to understand general and system-specific factors that are likely to influence acceptability of PTW assistive systems, including barriers that may prevent uptake and proper use of systems, through a large-scale survey of European riders. The survey was available in seven languages and attracted 6297 respondents. Respondents were frequent riders, who rode primarily for leisure purposes and had high awareness of assistive systems. Cluster analysis revealed two groups based on overall acceptability of assistive systems. The moderate and low acceptance clusters differed in terms of riding practices, risk perception, attitudes towards rule breaking, and some personality traits. Overall acceptability was low, but riders who perceive greater risk in riding display higher acceptability. Acceptability was highest for systems that do not interfere with the riding task, are well-known and/or considered reliable (e.g., night vision, ABS, eCall, advanced front-lighting system). In general, riders believe that existing safety equipment (e.g., helmets, protective clothing) is more reliable, provides greater resistance, and is considerably cheaper than more sophisticated assistive technology. Riders believe that innovations should focus on protective equipment, since they believe crash prevention is better addressed through rider training. Finally, riders felt there should be more emphasis on vehicle tyre condition, while tyre pressure control systems were identified as potentially helpful.

Design of plastic diffractive–refractive compact zoom lenses for visible–near-IR spectrum

Abstract: The requirements for selecting the initial scheme for a compact plastic zoom lens are formulated. The main stages of the initial scheme of the transformation, incorporating the diffractive lens and replacement of the lenses’ glasses by optical plastics, are presented. The efficiency of the suggested techniques of the optical layout process are demonstrated by using the example of the design and analysis of a zoom lens intended for use in security cameras for day or night vision.

Search and detection modeling of military imaging systems

Abstract: For more than 50 years, the U.S. Army RDECOM CERDEC Night Vision and Electronic Sensors Directorate (NVESD) has been studying the science behind the human processes of searching and detecting, and using that knowledge to develop and refine its models for military imaging systems. Modeling how human observers perform military tasks while using imaging systems in the field and linking that model with the physics of the systems has resulted in the comprehensive sensor models we have today. These models are used by the government, military, industry, and academia for sensor development, sensor system acquisition, military tactics development, and war-gaming. From the original hypothesis put forth by John Johnson in 1958, to modeling time-limited search, to modeling the impact of motion on target detection, to modeling target acquisition performance in different spectral bands, the concept of search has a wide-ranging history. Our purpose is to present a snapshot of that history; as such, it will begin with a description of the search-modeling task, followed by a summary of highlights from the early years, and concluding with a discussion of search and detection modeling today and the changing battlefield. Some of the topics to be discussed will be classic search, clutter, computational vision models and the ACQUIRE model with its variants. We do not claim to present a complete history here, but rather a look at some of the work that has been done, and this is meant to be an introduction to an extensive amount of work on a complex topic. That said, it is hoped that this overview of the history of search and detection modeling of military imaging systems pursued by NVESD directly, or in association with other government agencies or contractors, will provide both the novice and experienced search modeler with a useful historical summary and an introduction to current issues and future challenges.

Intelligent active safety forewarning system of automobile

Abstract: The utility model discloses an intelligent active safety forewarning system of an automobile. The intelligent active safety forewarning system comprises a microprocessor, a vehicular navigation module, an alcohol measurement and control module, an identify verification module, a video acquisition detection module, a temperature measurement and control module, a tire pressure measurement and control module, an anti-collision forewarning module, an adaptive cruise control module, a night vision assisting module and a panoramic image module; the vehicular navigation module is used for reading the longitude and the latitude of a current location of the automobile and can realize a real-time navigation function for a driver of the automobile; the alcohol measurement and control module is used for measuring the concentration of alcohol in air in the automobile at present; the identity verification module is used for verifying the identity of the driver by safety antitheft key and safe password input methods and the like; the video acquisition detection module is used for monitoring whether the driver drives the automobile when tired or not; the temperature measurement and control module is used for measuring the internal temperature and the external temperature of a compartment of the automobile by the aid of internal and external temperature sensors of the automobile; the tire pressure measurement and control module can transmit warning information to the driver; the adaptive cruise control module is used for automatically keeping the safe distance from the automobile to a front automobile; all the modules are connected with the microprocessor. The intelligent active safety forewarning system has the advantages that technologies in the aspects of safety, communication, multimedia and the like are adopted for the intelligent active safety forewarning system, and the intelligent active safety forewarning system is wide in coverage.

Luminescent Electrophoretic Particles via Miniemulsion Polymerization for Night-Vision Electrophoretic Displays

Abstract: A novel glowing electrophoretic display (EPD) is achieved by luminescent electrophoretic particles (EPs), which is potentially to improve the situation in which the existing EPDs disable in darkness. To combine both modes of reflective and emissive displays, a trilayer luminescence EP is designed and synthesized via an improved miniemulsion polymerization. The luminescence EP is composed of a pigment core, a polystyrene interlayer, and a fluorescent coating. The particle sizes are from 140 to 170 nm, and the size distribution is narrow. Their ζ potential value is -12.4 mV, which is enough to migrate in the electrophoretic fluid by the driving of an electric field. The display performance of the particles in an EPD cell has been characterized under the bias of 20 V. Both the reflectance (491 nm) and fluorescence (521 nm) intensities of the EPD cell remained in a constant range after 30 switches.

Double-spectrum night vision instrument vehicle-mounted system and double-spectrum fusion design method

Abstract: The invention discloses a double-spectrum night vision instrument vehicle-mounted system and a double-spectrum fusion design method. The system comprises an infrared double-spectrum imaging die set used for imaging of a visible spectrum and an infrared spectrum and for collection, processing, fusion and transmission of the image data, an image receiving system used for completing the receiving of the image data, a display terminal used for displaying the images for an observer, and a control terminal used for controlling the function and on-off of an imaging mode. Due to the adoption of the system and the method, the problem that coaxial imaging of the double spectrum image is slight bad is solved, the machining precision requirement of the imaging system is reduced, more clear images are provided for forward observation for a train; a fusion method based on a scene moving object provides a reference source for the double-spectrum imaging system, the computation load is reduced, the registering reliability is improved, the imaging on the hardware is convenient, and the real-time performance is possessed; a weight fusion method based on multi-scale bilateral filtering is simple and feasible, improves the imaging detail information and reduces the calculation ability.

Radiometric characterization of a novel LED array system for visual assessment

Abstract: Light that enters the eye can be distorted due to several factors leading to a poor visual performance. The purpose of this paper is to describe and characterize the light-emitting diode (LED) display system to be used in a new device to assess visual quality under high glare conditions. The device has a central white LED and surrounding white LEDs distributed in a radial manner. Each LED is controlled independently using special designed software. The spectral power distribution and color of the LEDs were assessed at different voltage intensities to test the response in terms of output luminance and spectral distribution. It was found that the typical maximum luminance was about 2800 cd/m2 and 6 cd/m2 for the central and surrounding LEDs, respectively. Their color was found to be within the ΔE∗ab range of 2.6 and 0.23, respectively, if the minimum and maximum intensities are considered. The characterization of this device was proved successfully, which might indicate its usefulness in future visual asses...

Human action recognition for night vision using temporal templates with infrared thermal camera

Abstract: This paper presents human action recognition at night. Because it is difficult to detect object applying only color or infrared camera at night, we use infrared thermal camera. And temporal templates, HoG and SVM are employed. Our experimental results show that the system achieves good performance.

What the clock tells the eye: lessons from an ancient arthropod.

Abstract: Circadian changes in visual sensitivity have been observed in a wide range of species, vertebrates, and invertebrates, but the processes impacted and the underlying mechanisms largely are unexplored. Among arthropods, effects of circadian signals on vision have been examined in most detail in the lateral compound eye (LE) of the American horseshoe crab, Limulus polyphemus, a chelicerate arthropod. As a consequence of processes influenced by a central circadian clock, Limulus can see at night nearly as well as they do during the day. The effects of the clock on horseshoe crab LE retinas are diverse and include changes in structure, gene expression, and rhabdom biochemistry. An examination of the known effects of circadian rhythms on LEs shows that the effects have three important outcomes: an increase in visual sensitivity at night, a rapid decrease in visual sensitivity at dawn, and maintenance of eyes in a relatively low state of sensitivity during the day, even in the dark. All three outcomes may be critically important for species' survival. Specific effects of circadian rhythms on vision will certainly vary with species and according to life styles. Studies of the circadian regulation of Limulus vision have revealed that these effects can be extremely diverse and profound and suggest that circadian clocks can play a critical role in the ability of animals to adapt to the dramatic daily changes in ambient illumination.