Helmet-mounted pilot night vision systems: Human factors issues

Helmet-mounted displays of infrared imagery (forward-looking infrared (FLIR)) allow helicopter pilots to perform low level missions at night and in low visibility. However, pilots experience high visual and cognitive workload during these missions, and their performance capabilities may be reduced. Human factors problems inherent in existing systems stem from three primary sources: the nature of thermal imagery; the characteristics of specific FLIR systems; and the difficulty of using FLIR system for flying and/or visually acquiring and tracking objects in the environment. The pilot night vision system (PNVS) in the Apache AH-64 provides a monochrome, 30 by 40 deg helmet-mounted display of infrared imagery. Thermal imagery is inferior to television imagery in both resolution and contrast ratio. Gray shades represent temperatures differences rather than brightness variability, and images undergo significant changes over time. The limited field of view, displacement of the sensor from the pilot's eye position, and monocular presentation of a bright FLIR image (while the other eye remains dark-adapted) are all potential sources of disorientation, limitations in depth and distance estimation, sensations of apparent motion, and difficulties in target and obstacle detection. Insufficient information about human perceptual and performance limitations restrains the ability of human factors specialists to provide significantly improved specifications, training programs, or alternative designs. Additional research is required to determine the most critical problem areas and to propose solutions that consider the human as well as the development of technology

Helicopter flights with night-vision goggles: Human factors aspects

Night-vision goggles (NVGs) and, in particular, the advanced, helmet-mounted Aviators Night-Vision-Imaging System (ANVIS) allows helicopter pilots to perform low-level flight at night. It consists of light intensifier tubes which amplify low-intensity ambient illumination (star and moon light) and an optical system which together produce a bright image of the scene. However, these NVGs do not turn night into day, and, while they may often provide significant advantages over unaided night flight, they may also result in visual fatigue, high workload, and safety hazards. These problems reflect both system limitations and human-factors issues. A brief description of the technical characteristics of NVGs and of human night-vision capabilities is followed by a description and analysis of specific perceptual problems which occur with the use of NVGs in flight. Some of the issues addressed include: limitations imposed by a restricted field of view; problems related to binocular rivalry; the consequences of inappropriate focusing of the eye; the effects of ambient illumination levels and of various types of terrain on image quality; difficulties in distance and slope estimation; effects of dazzling; and visual fatigue and superimposed symbology. These issues are described and analyzed in terms of their possible consequences on helicopter pilot performance. The additional influence of individual differences among pilots is emphasized. Thermal imaging systems (forward looking infrared (FLIR)) are described briefly and compared to light intensifier systems (NVGs). Many of the phenomena which are described are not readily understood. More research is required to better understand the human-factors problems created by the use of NVGs and other night-vision aids, to enhance system design, and to improve training methods and simulation techniques

Secret Spending in the States

Six years after Citizens United enabled unfettered spending in our elections, the use of so-called dark money has become disturbingly common. Contrary to the Supreme Court's assumption that this unlimited spending would be transparent to voters, at the federal level powerful groups have since 2010 poured hundreds of millions of dollars into influencing elections while obscuring the sources of their funding. But it is at the state and local levels that secret spending is arguably at its most damaging. For a clear understanding of the degree to which dark money is warping American democracy, state ballot referenda and local school board contests may be a better starting point than the presidential campaign or even congressional races. As Chris Herstam, a former Republican majority whip in the Arizona House of Representatives and now lobbyist, put it, "In my 33 years in Arizona politics and government, dark money is the most corrupting influence I have seen."This report documents how far outside spending -- election spending that is not coordinated with candidates -- at the state and local levels has veered from the vision of democratic transparency the Citizens United Court imagined, drawing on an extensive database of news accounts, interviews with a range of stakeholders, campaign finance and tax records, court cases, and social science research. For the first time, it also measures changes in dark money – and a thus far unrecognized rise in what we term "gray money" – at the state level, by analyzing spender and contributor reports in six of nine states where sufficient usable data were available. This set of six geographically and demographically diverse states, comprising Alaska, Arizona, California, Colorado, Maine, and Massachusetts, represents approximately 20 percent of the nation's population.

Crommet Creek Conservation Area Management Plan

The Crommet Creek Conservation Area comprises the largest block of natural lands in the immediate Great Bay watershed, and in New Hampshire’s North Atlantic Coast Ecoregion. It includes the entire watershed of two tidal creeks that flow directly into the Great Bay Estuary. The area has been identified by the Great Bay Resource Protection Partnership as a protection priority due to the size of the natural area; the diversity of habitats and wildlife it supports; and it’s integral role in protecting the regional water quality and resources within the Great Bay Estuary. The Conservation Area includes headwater wetlands, and the entire spectrum of freshwater and estuarine wetland and aquatic communities along both Lubberland and Crommet creeks. The Great Bay is a shallow inland tidal estuary of national importance for migratory birds. The Great Bay supports 29 species of waterfowl, 27 species of shorebirds, 13 species of wading birds, osprey and bald eagle. The Estuary is unique in that it is recessed 9 miles from the ocean along the Piscataqua River. Although development is increasing in the watershed, it remains one of the more healthy and viable estuarine ecosystems on the North Atlantic coast

Clock and reset synchronization of high-integrity lockstep self-checking pairs

An apparatus comprises first and second modules configured to operate in a lockstep mode and a reset mode. Each of the first and second modules is configured to asynchronously enter the reset mode when a parent reset signal is asserted at the respective each module. Each of the first and second modules is configured to, in response to the asserted parent reset signal being negated at the respective each module, indicate to the respective other module that the respective each module is ready to exit the reset mode and exit the reset mode when the respective other module has also indicated that the respective other module is ready to exit the reset mode

QCD on the connection machine: beyond *LISP

We report on the status of code development for a simulation of quantum chromodynamics (QCD) with dynamical Wilson fermions on the Connection Machine model CM-2. Our original code, written in Lisp, gave performance in the near-GFLOPS range. We have rewritten the most time-consuming parts of the code in the low-level programming systems CMIS, including the matrix multiply and the communication. Current versions of the code run at approximately 3.6 GFLOPS for the fermion matrix inversion, and we expect the next version to reach or exceed 5 GFLOPS

Graduate Colleague Mentorship: Meaningful Connections for Emerging Women in Student Affairs

The Vermont Connection, at its core, is about people who invest in people. As aspiring and practicing student affairs educators, we invest in ourselves, in our students, in our colleagues, and in our research—research that frequently centers on the relationships among these groups of people. We invest because we grew from relationships with those who cared enough to do the same for us. We are the product of myriad connections across time and landscapes, knit together in our common experience in the University of Vermont’s Higher Education and Student Affairs (HESA) program. Intentional connection building is the purpose of HESA’s Graduate Colleague (GC) program, where incoming first-year students are matched with second-year students to assist in the transition to Vermont, the University, and HESA. In the following article, five generations of GCs discuss, through the lens of feminist theory, how our special connection informed and shaped each of our academic experiences, professional development, and voice-finding processes

Real-Time Distributed Embedded Oscillator Operating Frequency Monitoring

A document discusses the utilization of embedded clocks inside of operating network data links as an auxiliary clock source to satisfy local oscillator monitoring requirements. Modem network interfaces, typically serial network links, often contain embedded clocking information of very tight precision to recover data from the link. This embedded clocking data can be utilized by the receiving device to monitor the local oscillator for tolerance to required specifications, often important in high-integrity fault-tolerant applications. A device can utilize a received embedded clock to determine if the local or the remote device is out of tolerance by using a single link. The local device can determine if it is failing, assuming a single fault model, with two or more active links. Network fabric components, containing many operational links, can potentially determine faulty remote or local devices in the presence of multiple faults. Two methods of implementation are described. In one method, a recovered clock can be directly used to monitor the local clock as a direct replacement of an external local oscillator. This scheme is consistent with a general clock monitoring function whereby clock sources are clocking two counters and compared over a fixed interval of time. In another method, overflow/underflow conditions can be used to detect clock relationships for monitoring. These network interfaces often provide clock compensation circuitry to allow data to be transferred from the received (network) clock domain to the internal clock domain. This circuit could be modified to detect overflow/underflow conditions of the buffering required and report a fast or slow receive clock, respectively

Early initiation of a replication origin tethered at the nuclear periphery

Peer reviewedPublisher PD

Recent development and perspectives of machines for lattice QCD

I highlight recent progress in cluster computer technology and assess status and prospects of cluster computers for lattice QCD with respect to the development of QCDOC and apeNEXT. Taking the LatFor test case, I specify a 512-processor QCD-cluster better than 1$/Mflops.Comment: 14 pages, 17 figures, Lattice2003(plenary