Haul-out behavior of harbor seals (Phoca vitulina in Hood Canal, Washington.

Directory of Open Access Journals (Sweden)

Josh M London

Full Text Available The goal of this study was to model haul-out behavior of harbor seals (Phoca vitulina in the Hood Canal region of Washington State with respect to changes in physiological, environmental, and temporal covariates. Previous research has provided a solid understanding of seal haul-out behavior. Here, we expand on that work using a generalized linear mixed model (GLMM with temporal autocorrelation and a large dataset. Our dataset included behavioral haul-out records from archival and VHF radio tag deployments on 25 individual seals representing 61,430 seal hours. A novel application for increased computational efficiency allowed us to examine this large dataset with a GLMM that appropriately accounts for temporal autocorellation. We found significant relationships with the covariates hour of day, day of year, minutes from high tide and year. Additionally, there was a significant effect of the interaction term hour of day : day of year. This interaction term demonstrated that seals are more likely to haul out during nighttime hours in August and September, but then switch to predominantly daylight haul-out patterns in October and November. We attribute this change in behavior to an effect of human disturbance levels. This study also examined a unique ecological event to determine the role of increased killer whale (Orcinus orca predation on haul-out behavior. In 2003 and 2005 these harbor seals were exposed to unprecedented levels of killer whale predation and results show an overall increase in haul-out probability after exposure to killer whales. The outcome of this study will be integral to understanding any changes in population abundance as a result of increased killer whale predation.

Oxygen Uptake - Live Hauling of Fish

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — In certain markets, live fish can be sold for substantially higher prices than fresh dressed fish. A significant live-haul industry has developed in the U.S. and...

Dissolved Oxygen - Live Hauling of Fish

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — In certain markets, live fish can be sold for substantially higher prices than fresh dressed fish. A significant live-haul industry has developed in the U.S. and...

Collection and hauling of cereal grain chaff

Energy Technology Data Exchange (ETDEWEB)

Reding, B.; Leduc, P. [Prairie Agricultural Machinery Institute, Humboldt, Saskatchewan (Canada); Stumborg, M. [Agriculture Canada, Ottawa, Ontario (Canada)

1993-12-31

Cereal grain chaff has been identified by Energy Mines and Resources, Canada, and Agriculture Canada, as a suitable feedstock for ethanol production. Canada produces 13,300,000 t (14,600,000 ton) of cereal grain chaff annually; mainly in the prairie region. Work conducted at the Prairie Agricultural Machinery Institute (PAMI), Humboldt, Saskatchewan, has determined that the collection of chaff for centralized processing is a problem due to low bulk density in its natural state. This problem can be overcome by densification using either compression or size reduction. Either method will be economical in a chaff shed radius of 140 km (87 mi) when chaff is densified to 160 kg/m{sup 3} (10 lb/ft{sup 3}). The size reduction method of densification may be economical to hauling distances exceeding 166 km (103 mi), particularly if size reduction is a required part of ethanol processing. Further work is under way to develop the required equipment modifications to allow existing farm equipment to be used for this purpose.

An introduction to the integrated design of surface mine haul roads

Energy Technology Data Exchange (ETDEWEB)

Thompson, R.J.; Visser, A.T. [University of Pretoria, Pretoria (South Africa). Dept. of Mining Engineering

1997-12-01

The world-wide expansion of surface mining has led to the development of very large off-highway trucks currently capable of hauling layloads in excess of 160 t. Typical axle loads ranging from 110 t to 170 t are applied to haul roads that have been, at best, empirically designed on the premise of `satisfactory` or `failed`, both in terms of structure and function of the road. The use of these empirical pavement design techniques will prove inadequate when high axle loads are encountered. Not only will the maintenance costs of existing haul roads of inadequate thickness increase, but vehicle operating and maintenance costs will also increase prohibitively. Under these conditions there is thus a clearly defined need for improved construction and management techniques for flexible mine haulage roads, appropriate for the wheel loads of vehicles now in use. The aim of this paper is to introduce developments in haul road structural, functional and maintenance design and management which overcome the limitations associated with the previously empirical design techniques and to show how these developments are combined into an integrated design strategy combining construction techniques, available material and road maintenance equipment with hauler choice to realise a reduction in haulage and road maintenance costs. Future contributions will enumerate on the fundamental haul road structural, functional and maintenance design and management research from which these developments originated. 7 refs., 5 figs., 2 tabs.

A Cost Effective Method for Determining the Position of Mine Haul Road Defects from the Road Edge

Directory of Open Access Journals (Sweden)

Frank Sokolic

2010-01-01

Full Text Available This paper describes a simple method for estimating haul road defect positions from alongside roads. It is a method that is cheap and easy to implement, needing only a minimal amount of field equipment and training. Observers are required to estimate the bearing and distance to a defect, and to record their location using a GPS receiver. All further processing is automated and can be done entirely within a spatially-enabled database management system such as Microsoft SQL Server or PostgreSQL.

Application of flywheel energy storage for heavy haul locomotives

International Nuclear Information System (INIS)

Spiryagin, Maksym; Wolfs, Peter; Szanto, Frank; Sun, Yan Quan; Cole, Colin; Nielsen, Dwayne

2015-01-01

Highlights: • A novel design for heavy haul locomotive equipped with a flywheel energy storage system is proposed. • The integrated intelligent traction control system was developed. • A flywheel energy storage system has been tested through a simulation process. • The developed hybrid system was verified using an existing heavy haul railway route. • Fuel efficiency analysis confirms advantages of the hybrid design. - Abstract: At the present time, trains in heavy haul operations are typically hauled by several diesel-electric locomotives coupled in a multiple unit. This paper studies the case of a typical consist of three Co–Co diesel-electric locomotives, and considers replacing one unit with an alternative version, with the same design parameters, except that the diesel-electric plant is replaced with flywheel energy storage equipment. The intelligent traction and energy control system installed in this unit is integrated into the multiple-unit control to allow redistribution of the power between all units. In order to verify the proposed design, a three-stage investigation has been performed as described in this paper. The initial stage studies a possible configuration of the flywheel energy storage system by detailed modelling of the proposed intelligent traction and energy control system. The second stage includes the investigation and estimation of possible energy flows using a longitudinal train dynamics simulation. The final stage compares the conventional and the proposed locomotive configurations considering two parameters: fuel efficiency and emissions reduction.

US long distance fiber optic networks: Technology, evolution and advanced concepts. Volume 2: Fiber optic technology and long distance networks

Science.gov (United States)

1986-10-01

The study projects until 2000 the evolution of long distance fiber optic networks in the U.S. Volume 1 is the Executive Summary. Volume 2 focuses on fiber optic components and systems that are directly related to the operation of long-haul networks. Optimistic, pessimistic and most likely scenarios of technology development are presented. The activities of national and regional companies implementing fiber long haul networks are also highlighted, along with an analysis of the market and regulatory forces affecting network evolution. Volume 3 presents advanced fiber optic network concept definitions. Inter-LATA traffic is quantified and forms the basis for the construction of 11-, 15-, 17-, and 23-node networks. Using the technology projections from Volume 2, a financial model identifies cost drivers and determines circuit mile costs between any two LATAs. A comparison of fiber optics with alternative transmission concludes the report.

CFD Investigation on Long-Haul Passenger Bus

Science.gov (United States)

Tan, C. F.; Tee, B. T.; Law, H. C.; Lim, T. L.

2015-09-01

Air flow distribution is one of the important factors that will influence the bus passenger comfort during long haul travel. Poor air flow distribution not only cause discomfort to the bus passenger but also influence their travel mode as well. The main purpose of this study is to investigate the air flow performance of the bus air-conditioning system through CFD simulation approach. A 3D CAD model of air ducts was drawn and hence analysed by using CFD software, namely ANSYS Fluent, to determine the airflow rate for every outlets of the air-conditioning system. The simulated result was then validated with experimental data obtained from prototype model of air duct. Based on the findings, new design concepts is proposed with the aim to meet the industry requirement as well as to improve the bus passenger comfort during long haul travel.

75 FR 35033 - U-Haul International, Inc. and AMERCO; Analysis of Agreement Containing Consent Order to Aid...

Science.gov (United States)

2010-06-21

... closest competitor in the consumer truck rental industry to join with U-Haul in a collusive scheme to...-Haul International, Inc. U-Haul's primary competitors in the truck rental industry are Avis Budget... several years leading up to 2006, Mr. Shoen was aware that price competition from Budget was forcing U...

Consistent haul road condition monitoring by means of vehicle response normalisation with Gaussian processes

CSIR Research Space (South Africa)

Heyns, T

2012-12-01

Full Text Available Suboptimal haul road management policies such as routine, periodic and urgent maintenance may result in unnecessary cost, both to roads and vehicles. A recent idea is to continually access haul road condition based on measured vehicle response...

77 FR 45921 - Alaskan Fuel Hauling as a Restricted Category Special Purpose Flight Operation

Science.gov (United States)

2012-08-02

... operations, each aircraft used to transport fuel will be required to receive FAA certification for the... regulations. The special purpose of Alaskan fuel hauling was considered for aircraft type-certificated under... required for this special purpose. The fuel hauling system must be shown to meet the applicable...

Total Ammonia Nitrogen (TAN) - Live Hauling of Fish

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — In certain markets, live fish can be sold for substantially higher prices than fresh dressed fish. A significant live-haul industry has developed in the U.S. and...

Un-ionized Ammonia (UIA) - Live Hauling of Fish

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — In certain markets, live fish can be sold for substantially higher prices than fresh dressed fish. A significant live-haul industry has developed in the U.S. and...

Fuels planning: science synthesis and integration; economic uses fact sheet 02: log hauling cost

Science.gov (United States)

Rocky Mountain Research Station USDA Forest Service

2004-01-01

Knowing the cost of fuel reduction treatments and associated activities, such as hauling cut trees, is essential for fire and fuels planning. This fact sheet explores the main factors that determine the cost of hauling cut trees and points the user to an interactive tool that can help plan for those and other expenses.

Commodification of Religious Tradition: Critical Study on Religious Tradition Tourism Haul at Pasar Kliwon Surakarta

Directory of Open Access Journals (Sweden)

Muhammad Ferri Setiawan

2017-02-01

Full Text Available The policy on tourism development program of Surakarta especially on the calendar of the event takes advantage from religious tradition as tourism commodity. The purpose of this study is to describe the religious tradition haul, the programs by the tourism department of Surakarta, and how commodification through a well implemented marketing communications process, messaging, and other media, as well as responses from the audience regarding the marketing of haul tradition in general toward creating a leading tourism object. Haul which is a tradition for commemorating the death of clerics (ulama who are followed by some local communities in Surakarta, especially those in Pasar Kliwon Regency, is utilized in tourism. Through critical study, the cultural values that are supposed to be preserved, changed into marketing values to attract visitors. The used media are the advertisement and the calendar of events. The local community gain advantages economically from this policy, but they object to it socio-culturally. Meanwhile, the tourists are generally interested in haul tradition.

Factors affecting driver alertness during the operation of haul trucks in the South African mining industry

CSIR Research Space (South Africa)

Schutte, PC

2003-06-01

Full Text Available In view of the seriousness of haul trucks accidents, SIMRAC initiated research to identify factors affecting haul truck driver alertness during mining operations. The information obtained during the risk analysis was used to identify possible...

Aerial surveys of seals at Rødsand seal sanctuary and adjacent haul-out sites

DEFF Research Database (Denmark)

Teilmann, J.; Dietz, R.; Edren, Susi M.C.

This report describes the preliminary results of aerial surveys at Rødsand seal sanctuary, southeast Denmark and adjacent seal haul-out sites in southwestern Baltic. The work was carried out in connection with studies of potential effects of the Nysted offshore wind farm. Rødsand seal sanctuary...... is a part of seal management area 4, and the area is believed to hold a more or less closed population with little exchange to other areas. Although the harbour seal is relatively stationary there may be movements between the haul-out sites in the area. A possible reaction to disturbance from...... the construction and operation of the wind farm may be that the seals use other haul-out sites to a higher extend....

49 CFR 1242.76 - Administration; pickup and delivery, marine line haul, and rail substitute service; loading...

Science.gov (United States)

2010-10-01

... haul, and rail substitute service; loading, unloading and local marine; protective services; freight... SEPARATION OF COMMON OPERATING EXPENSES BETWEEN FREIGHT SERVICE AND PASSENGER SERVICE FOR RAILROADS 1 Operating Expenses-Transportation § 1242.76 Administration; pickup and delivery, marine line haul, and rail...

Factors Affecting Haul-Out Behavior of Harbor Seals (Phoca vitulina in Tidewater Glacier Inlets in Alaska: Can Tourism Vessels and Seals Coexist?

Directory of Open Access Journals (Sweden)

Gail M Blundell

Full Text Available Large numbers of harbor seals (Phoca vitulina use habitat in tidewater glaciers in Alaska for pupping, breeding, and molting. Glacial fjords are also popular tourist destinations; however, visitation by numerous vessels can result in disturbance of seals during critical life-history phases. We explored factors affecting haul-out behavior of harbor seals at a glacial site frequented by tourism vessels. In 2008-10, we deployed VHF transmitters on 107 seals in Endicott Arm, Alaska. We remotely monitored presence and haul-out behavior of tagged seals and documented vessel presence with time-lapse cameras. We evaluated the influence of environmental and physical factors on the probability of being hauled out, duration of haul-out bouts, and as factors associated with the start and end of a haulout. Location, season, hour, and interactions of location by year, season, hour, and sex significantly influenced haul-out probability, as did ice, weather, and vessels. Seals were more likely to be hauled out with greater ice availability during the middle of the day, and less likely to be hauled out if vessels were present. Cruise ships had the strongest negative effect; however, most vessel types negatively affected haul-out probability. Haul-out duration was longest in association with starting on incoming tides, clear skies, no precipitation, occurring in the middle of the day, and ending in the late afternoon or evening. End of haulouts was associated with increasing cloud cover, low ice availability, and vessel presence; large-sized tourism vessels or all-vessel-types combined were significant predictors of ending a haul-out bout. Probability of being hauled out was highest in June, during pupping season. Potential disturbances of harbor seals could be reduced, enabling longer resting times for seals and fewer interruptions for nursing pups, if vessels focused the majority of visits to glacial habitat to before or after the hours of 08:00-17:00 or, less

Factors Affecting Haul-Out Behavior of Harbor Seals (Phoca vitulina) in Tidewater Glacier Inlets in Alaska: Can Tourism Vessels and Seals Coexist?

Science.gov (United States)

Blundell, Gail M; Pendleton, Grey W

2015-01-01

Large numbers of harbor seals (Phoca vitulina) use habitat in tidewater glaciers in Alaska for pupping, breeding, and molting. Glacial fjords are also popular tourist destinations; however, visitation by numerous vessels can result in disturbance of seals during critical life-history phases. We explored factors affecting haul-out behavior of harbor seals at a glacial site frequented by tourism vessels. In 2008-10, we deployed VHF transmitters on 107 seals in Endicott Arm, Alaska. We remotely monitored presence and haul-out behavior of tagged seals and documented vessel presence with time-lapse cameras. We evaluated the influence of environmental and physical factors on the probability of being hauled out, duration of haul-out bouts, and as factors associated with the start and end of a haulout. Location, season, hour, and interactions of location by year, season, hour, and sex significantly influenced haul-out probability, as did ice, weather, and vessels. Seals were more likely to be hauled out with greater ice availability during the middle of the day, and less likely to be hauled out if vessels were present. Cruise ships had the strongest negative effect; however, most vessel types negatively affected haul-out probability. Haul-out duration was longest in association with starting on incoming tides, clear skies, no precipitation, occurring in the middle of the day, and ending in the late afternoon or evening. End of haulouts was associated with increasing cloud cover, low ice availability, and vessel presence; large-sized tourism vessels or all-vessel-types combined were significant predictors of ending a haul-out bout. Probability of being hauled out was highest in June, during pupping season. Potential disturbances of harbor seals could be reduced, enabling longer resting times for seals and fewer interruptions for nursing pups, if vessels focused the majority of visits to glacial habitat to before or after the hours of 08:00-17:00 or, less optimally, 09:00-16:00.

On achievable rates for long-haul fiber-optic communications

NARCIS (Netherlands)

Fehenberger, T.; Alvarado, A.; Bayvel, P.; Hanik, N.

2015-01-01

Lower bounds on mutual information (MI) of long-haul optical fiber systems for hard-decision and soft-decision decoding are studied. Ready-to-use expressions to calculate the MI are presented. Extensive numerical simulations are used to quantify how changes in the optical transmitter, receiver, and

The Problem of Multiple Criteria Selection of the Surface Mining Haul Trucks

Science.gov (United States)

Bodziony, Przemysław; Kasztelewicz, Zbigniew; Sawicki, Piotr

2016-06-01

Vehicle transport is a dominant type of technological processes in rock mines, and its profit ability is strictly dependent on overall cost of its exploitation, especially on diesel oil consumption. Thus, a rational design of transportation system based on haul trucks should result from thorough analysis of technical and economic issues, including both cost of purchase and its further exploitation, having a crucial impact on the cost of minerals extraction. Moreover, off-highway trucks should be selected with respect to all specific exploitation conditions and even the user's preferences and experience. In this paper a development of universal family of evaluation criteria as well as application of evaluation method for haul truck selection process for a specific exploitation conditions in surface mining have been carried out. The methodology presented in the paper is based on the principles of multiple criteria decision aiding (MCDA) using one of the ranking method, i.e. ELECTRE III. The applied methodology has been allowed for ranking of alternative solution (variants), on the considered set of haul trucks. The result of the research is a universal methodology, and it consequently may be applied in other surface mines with similar exploitation parametres.

A neural network driving curve generation method for the heavy-haul train

Directory of Open Access Journals (Sweden)

Youneng Huang

2016-05-01

Full Text Available The heavy-haul train has a series of characteristics, such as the locomotive traction properties, the longer length of train, and the nonlinear train pipe pressure during train braking. When the train is running on a continuous long and steep downgrade railway line, the safety of the train is ensured by cycle braking, which puts high demands on the driving skills of the driver. In this article, a driving curve generation method for the heavy-haul train based on a neural network is proposed. First, in order to describe the nonlinear characteristics of train braking, the neural network model is constructed and trained by practical driving data. In the neural network model, various nonlinear neurons are interconnected to work for information processing and transmission. The target value of train braking pressure reduction and release time is achieved by modeling the braking process. The equation of train motion is computed to obtain the driving curve. Finally, in four typical operation scenarios, comparing the curve data generated by the method with corresponding practical data of the Shuohuang heavy-haul railway line, the results show that the method is effective.

Establishment and verification of three-dimensional dynamic model for heavy-haul train-track coupled system

Science.gov (United States)

Liu, Pengfei; Zhai, Wanming; Wang, Kaiyun

2016-11-01

For the long heavy-haul train, the basic principles of the inter-vehicle interaction and train-track dynamic interaction are analysed firstly. Based on the theories of train longitudinal dynamics and vehicle-track coupled dynamics, a three-dimensional (3-D) dynamic model of the heavy-haul train-track coupled system is established through a modularised method. Specifically, this model includes the subsystems such as the train control, the vehicle, the wheel-rail relation and the line geometries. And for the calculation of the wheel-rail interaction force under the driving or braking conditions, the large creep phenomenon that may occur within the wheel-rail contact patch is considered. For the coupler and draft gear system, the coupler forces in three directions and the coupler lateral tilt angles in curves are calculated. Then, according to the characteristics of the long heavy-haul train, an efficient solving method is developed to improve the computational efficiency for such a large system. Some basic principles which should be followed in order to meet the requirement of calculation accuracy are determined. Finally, the 3-D train-track coupled model is verified by comparing the calculated results with the running test results. It is indicated that the proposed dynamic model could simulate the dynamic performance of the heavy-haul train well.

Problems and issues for short-haul air transportation.

Science.gov (United States)

Vittek, J. F., Jr.

1972-01-01

The problems of developing an efficient short-haul air system are not primarily technical, but economic and political. The key issues are whether the community will accept new and expanded air facilities, what standards of service the passengers will demand and how the system will evolve. The solutions recommended are national in scope and require the federal government to take a leading role.

Optical strain measurement for fault detection in haul-truck tires

International Nuclear Information System (INIS)

Kotchon, A; Nobes, D S; Lipsett, M G

2012-01-01

Tire condition is integral to the safe operation of heavy machinery, such as ultra-class haul trucks. A new approach to haul truck tire monitoring is being investigated based on optical strain measurement, which has the advantage of providing quantitative information from sensors that do not contact the tire. A laboratory-scale apparatus has been constructed to monitor a tire as it is subjected to various loads and pressures. Digital image correlation is used to calculate the deformation in the tire. Using this method, damage resulting from a horizontal and vertical cut created on the tire surface could be detected. A three-dimensional surface reconstruction of the tire was created to assist in the characterization of more complex damage types such as wear and fatigue. In addition to providing information for a possible industrial scale damage detection system, this apparatus will also further the understanding of damage mechanisms in tires.

Projection-based circular constrained state estimation and fusion over long-haul links

Energy Technology Data Exchange (ETDEWEB)

Liu, Qiang [ORNL; Rao, Nageswara S. [ORNL

2017-07-01

In this paper, we consider a scenario where sensors are deployed over a large geographical area for tracking a target with circular nonlinear constraints on its motion dynamics. The sensor state estimates are sent over long-haul networks to a remote fusion center for fusion. We are interested in different ways to incorporate the constraints into the estimation and fusion process in the presence of communication loss. In particular, we consider closed-form projection-based solutions, including rules for fusing the estimates and for incorporating the constraints, which jointly can guarantee timely fusion often required in realtime systems. We test the performance of these methods in the long-haul tracking environment using a simple example.

Passenger thermal perceptions, thermal comfort requirements, and adaptations in short- and long-haul vehicles.

Science.gov (United States)

Lin, Tzu-Ping; Hwang, Ruey-Lung; Huang, Kuo-Tsang; Sun, Chen-Yi; Huang, Ying-Che

2010-05-01

While thermal comfort in mass transportation vehicles is relevant to service quality and energy consumption, benchmarks for such comfort that reflect the thermal adaptations of passengers are currently lacking. This study reports a field experiment involving simultaneous physical measurements and a questionnaire survey, collecting data from 2,129 respondents, that evaluated thermal comfort in short- and long-haul buses and trains. Experimental results indicate that high air temperature, strong solar radiation, and low air movement explain why passengers feel thermally uncomfortable. The overall insulation of clothing worn by passengers and thermal adaptive behaviour in vehicles differ from those in their living and working spaces. Passengers in short-haul vehicles habitually adjust the air outlets to increase thermal comfort, while passengers in long-haul vehicles prefer to draw the drapes to reduce discomfort from extended exposure to solar radiation. The neutral temperatures for short- and long-haul vehicles are 26.2 degrees C and 27.4 degrees C, while the comfort zones are 22.4-28.9 degrees C and 22.4-30.1 degrees C, respectively. The results of this study provide a valuable reference for practitioners involved in determining the adequate control and management of in-vehicle thermal environments, as well as facilitating design of buses and trains, ultimately contributing to efforts to achieve a balance between the thermal comfort satisfaction of passengers and energy conserving measures for air-conditioning in mass transportation vehicles.

An exploratory study of long-haul truck drivers' secondary tasks and reasons for performing them.

Science.gov (United States)

Iseland, Tobias; Johansson, Emma; Skoog, Siri; Dåderman, Anna M

2018-08-01

Research on drivers has shown how certain visual-manual secondary tasks, unrelated to driving, increase the risk of being involved in crashes. The purpose of the study was to investigate (1) if long-haul truck drivers in Sweden engage in secondary tasks while driving, what tasks are performed and how frequently, (2) the drivers' self-perceived reason/s for performing them, and (3) if psychological factors might reveal reasons for their engaging in secondary tasks. The study comprised 13 long-haul truck drivers and was conducted through observations, interviews, and questionnaires. The drivers performed secondary tasks, such as work environment related "necessities" (e.g., getting food and/or beverages from the refrigerator/bag, eating, drinking, removing a jacket, face rubbing, and adjusting the seat), interacting with a mobile phone/in-truck technology, and doing administrative tasks. The long-haul truck drivers feel bored and use secondary tasks as a coping strategy to alleviate boredom/drowsiness, and for social interaction. The higher number of performed secondary tasks could be explained by lower age, shorter driver experience, less openness to experience, lower honesty-humility, lower perceived stress, lower workload, and by higher health-related quality of life. These explanatory results may serve as a starting point for further studies on large samples to develop a safer and healthier environment for long-haul truck drivers. Copyright © 2018. Published by Elsevier Ltd.

Sleeper Cab Climate Control Load Reduction for Long-Haul Truck Rest Period Idling

Energy Technology Data Exchange (ETDEWEB)

Lustbader, J. A.; Kreutzer, C.; Adelman, S.; Yeakel, S.; Zehme, J.

2015-04-29

Annual fuel use for long-haul truck rest period idling is estimated at 667 million gallons in the United States. The U.S. Department of Energy’s National Renewable Energy Laboratory’s CoolCab project aims to reduce heating, ventilating, and air conditioning (HVAC) loads and resulting fuel use from rest period idling by working closely with industry to design efficient long-haul truck climate control systems while maintaining occupant comfort. Enhancing the thermal performance of cab/sleepers will enable smaller, lighter, and more cost-effective idle reduction solutions. In order for candidate idle reduction technologies to be implemented at the original equipment manufacturer and fleet level, their effectiveness must be quantified. To address this need, a number of promising candidate technologies were evaluated through experimentation and modeling to determine their effectiveness in reducing rest period HVAC loads. For this study, load reduction strategies were grouped into the focus areas of solar envelope, occupant environment, and conductive pathways. The technologies selected for a complete-cab package of technologies were “ultra-white” paint, advanced insulation, and advanced curtains. To measure the impact of these technologies, a nationally-averaged solar-weighted reflectivity long-haul truck paint color was determined and applied to the baseline test vehicle. Using the complete-cab package of technologies, electrical energy consumption for long-haul truck daytime rest period air conditioning was reduced by at least 35% for summer weather conditions in Colorado. The National Renewable Energy Laboratory's CoolCalc model was then used to extrapolate the performance of the thermal load reduction technologies nationally for 161 major U.S. cities using typical weather conditions for each location over an entire year.

Improvement of the mining technology with the ring movement scheme of the haul trucks

Directory of Open Access Journals (Sweden)

Slobodyanyuk R.V.

2016-04-01

Full Text Available The article describes the designed technology that allows to expand the use of the haul truck ring movement scheme and to reduce the share of an empty run time in the transportation cycle. A preliminary calculation of the efficiency of its usage has allowed to confirm the main advantages of this scheme over the existing one as follows: reducing the required number of transport for the needs of open-pit mine operation by increasing the productivity of mining trucks; decreasing the transport operating costs (some part of an empty truck movement occurs when the engine is switched off; dropping the probability of accidents (reduced a number of the counter transport maneuvers. The calculation showed the regularity of changes in the efficiency using the alternative scheme in relation to the basic one, which reflecting significantly higher effectiveness in situations with a smaller distance between the empty run sites of the ring scheme.

The Impact of Specialized Hauling Vehicles on Pavement and Bridge Deterioration

Science.gov (United States)

2017-12-01

This research study was performed to ensure that Texas complies with a Federal Highway Administration (FHWA) memo dated November 15, 2013, which requires each state to certify that it either does not permit operation of specialized hauling vehicles (...

Environmental Survey Report for the ETTP: Environmental Management Waste Management Facility (EMWMF) Haul Road Corridor, Oak Ridge, Tennessee

Energy Technology Data Exchange (ETDEWEB)

Peterson, M.J.

2005-12-20

This report summarizes the results of environmental surveys conducted within the corridor of a temporary haul road (''Haul Road'') to be constructed from East Tennessee Technology Park (ETTP) to the Environmental Management Waste Management Facility (EMWMF) located just west of the Y-12 National Security Complex (Y-12). Environmental surveys were conducted by natural resource experts at Oak Ridge National Laboratory who routinely assess the significance of various project activities on the Oak Ridge Reservation (ORR). ORNL assistance to the Haul Road Project included environmental assessments necessary to determine the best route for minimizing impacts to sensitive resources such as wetlands or rare plants. Once the final route was chosen, environmental surveys were conducted within the corridor to evaluate the impacts to sensitive resources that could not be avoided. The final Haul Road route follows established roads and a power-line corridor to the extent possible (Fig. 1). Detailed explanation regarding the purpose of the Haul Road and the regulatory context associated with its construction is provided in at least two major documents and consequently is not presented here: (1) Explanation of Significant Differences for the Record of Decision for the Disposal of Oak Ridge Reservation Comprehensive Environmental Response, Compensation, and Liability Act of 1980 Waste, Oak Ridge, Tennessee (January 2005, DOE/OR/01-2194&D2), and (2) Environmental Monitoring Plan for The ETTP to EMWMF Haul Road for the Disposal of Oak Ridge Reservation Comprehensive Environmental Response, Compensation, and Liability Act of 1980 Waste, Oak Ridge, Tennessee (April 2005, BJC/OR-2152). The focus of this report is a description of the sensitive resources to be impacted by Haul Road construction. Following a short description of the methods used for the environmental surveys, results and observations are presented in the following subsections: (1) General description

A New Method for Haul Road Design in Open-Pit Mines to Support Efficient Truck Haulage Operations

Directory of Open Access Journals (Sweden)

Jieun Baek

2017-07-01

Full Text Available The design of a haul road for an open-pit mine can significantly affect the cost associated with hauling ore and waste to the surface. This study proposes a new method for haul road design in open-pit mines to support efficient truck haulage operations. The road layout in open-pit mines was optimized by using raster-based least-cost path analysis, and the resulting zigzag road sections were simplified by applying the Douglas-Peucker algorithm. In addition, the road layout was modified by reflecting the radius of curvature suggested in the road design guides. Finally, a three-dimensional model reflecting the results of the road design was created by combining the road layout modification result with the slope of the open-pit mine and the bench design result. The application of the proposed method to an area containing gold deposits made it possible to design a haul road for open-pit mines such that it supported efficient truck haulage operations; furthermore, the time required for truck movement along the road could be estimated. The proposed method is expected to be useful for planning and designing open-pit mines and to facilitate the improvement of the road design function of existing mining software applications.

Workplace violence in long haul trucking: occupational health nursing update.

Science.gov (United States)

Anderson, Debra Gay

2004-01-01

Almost 2 million workdays and millions of dollars are lost annually because of non-fatal assaults suffered at the workplace (NIOSH, 1996). Twenty workers, on average, are murdered each week in the United States and an estimated 18,000 workers per week are victims of non-fatal assault (NIOSH, 2001). Violence and stress are two interrelated issues that affect the work force. In-depth studies of these issues have not been conducted with long haul truckers in general, or with women in non-traditional, male dominated fields such as the long haul trucking industry. Epidemiological data related to violence and stress experienced by these under-studied populations are needed to plan effective interventions to reduce occupational risks. Studies employing both qualitative and quantitative methods are needed to articulate risk and protective factors related to violence against workers (Runyan, 2001). Occupational health nurses are qualified to participate in the development and implementation of research and intervention studies to improve worker safety related to violence at the workplace for men and women in both traditional and non-traditional occupational roles.

US long distance fiber optic networks: Technology, evolution and advanced concepts. Volume 3: Advanced networks and economics

Science.gov (United States)

1986-10-01

This study projects until 2000 the evolution of long distance fiber optic networks in the U.S. Volume 1 is the executive Summary. Volume 2 focuses on fiber optic components and systems that are directly related to the operation of long-haul networks. Optimistic, pessimistic and most likely scenarios of technology development are presented. The activities of national and regional companies implementing fiber long haul networks are also highlighted, along with an analysis of the market and regulatory forces affecting network evolution. Volume 3 presents advanced fiber optic network concept definitions. Inter-LATA traffic is quantified and forms the basis for the construction of 11-, 15-, 17-, and 23-node networks. Using the technology projections from Volume 2, a financial model identifies cost drivers and determines circuit mile costs between any two LATAs. A comparison of fiber optics with alternative transmission concludes the report.

The effect of a large Danish offshore wind farm on harbor and grey seal haul-out behaviour

DEFF Research Database (Denmark)

Edrén, Susi Manuela Clermont; Andersen, Signe May; Teilmann, Jonas

2010-01-01

This study investigates the effects of the construction and operation of a large Danish offshore wind farm on harbor and gray seal haul-out behavior within a nearby (4 km) seal sanctuary. Time-lapse photography, visual monitoring, and aerial surveys were used to monitor the number of seals on land...... in daylight hours. Seals were monitored during two preconstruction periods (19 June–31 August 2001 and April–August 2002), a construction period of the wind farm (August 2002–December 2003), and a period of operation of the wind farm (December 2003–December 2004). Monthly aerial surveys were conducted...... to estimate the proportion of seals in the sanctuary relative to neighboring haul-out sites. From preconstruction to construction and through the first year of operation the number of harbor seals in the sanctuary increased at the same rate as the number of seals at the neighboring haul-out sites. No long...

Haul truck tire dynamics due to tire condition

International Nuclear Information System (INIS)

Anzabi, R Vaghar; Nobes, D S; Lipsett, M G

2012-01-01

Pneumatic tires are costly components on large off-road haul trucks used in surface mining operations. Tires are prone to damage during operation, and these events can lead to injuries to personnel, loss of equipment, and reduced productivity. Damage rates have significant variability, due to operating conditions and a range of tire fault modes. Currently, monitoring of tire condition is done by physical inspection; and the mean time between inspections is often longer than the mean time between incipient failure and functional failure of the tire. Options for new condition monitoring methods include off-board thermal imaging and camera-based optical methods for detecting abnormal deformation and surface features, as well as on-board sensors to detect tire faults during vehicle operation. Physics-based modeling of tire dynamics can provide a good understanding of the tire behavior, and give insight into observability requirements for improved monitoring systems. This paper describes a model to simulate the dynamics of haul truck tires when a fault is present to determine the effects of physical parameter changes that relate to faults. To simulate the dynamics, a lumped mass 'quarter-vehicle' model has been used to determine the response of the system to a road profile when a failure changes the original properties of the tire. The result is a model of tire vertical displacement that can be used to detect a fault, which will be tested under field conditions in time-varying conditions.

Haul truck tire dynamics due to tire condition

Science.gov (United States)

Vaghar Anzabi, R.; Nobes, D. S.; Lipsett, M. G.

2012-05-01

Pneumatic tires are costly components on large off-road haul trucks used in surface mining operations. Tires are prone to damage during operation, and these events can lead to injuries to personnel, loss of equipment, and reduced productivity. Damage rates have significant variability, due to operating conditions and a range of tire fault modes. Currently, monitoring of tire condition is done by physical inspection; and the mean time between inspections is often longer than the mean time between incipient failure and functional failure of the tire. Options for new condition monitoring methods include off-board thermal imaging and camera-based optical methods for detecting abnormal deformation and surface features, as well as on-board sensors to detect tire faults during vehicle operation. Physics-based modeling of tire dynamics can provide a good understanding of the tire behavior, and give insight into observability requirements for improved monitoring systems. This paper describes a model to simulate the dynamics of haul truck tires when a fault is present to determine the effects of physical parameter changes that relate to faults. To simulate the dynamics, a lumped mass 'quarter-vehicle' model has been used to determine the response of the system to a road profile when a failure changes the original properties of the tire. The result is a model of tire vertical displacement that can be used to detect a fault, which will be tested under field conditions in time-varying conditions.

The Effect of Corporate Influence in the Short Haul Business Travel Market

Science.gov (United States)

Mason, Keith J.

1999-01-01

The importance of corporate involvement in the decision making process for business related air travel is being increasingly recognised in the literature. Business travellers consume air services (i.e. they take airline flights), however; they may not be the principal decision-maker in the purchase. Also it is the organization that employs the traveller that incurs die cost for air travel. Consequently this research addresses the relationship between the traveller and the employing organisation in the purchase of air travel. In this paper traveller opinions on their corporate travel policy are evaluated using a Likert summated rating scale. The benefits sought, by the traveller, from the air service are also investigated and these benefits are used to segment the short haul business air travel market in the EU. Changes in the market for short haul business travel since the full liberalisation of the aviation market in-the EU are evaluated by comparing the data to an earlier study of similar travellers in 1992.

Impact of Paint Color on Rest Period Climate Control Loads in Long-Haul Trucks: Preprint

Energy Technology Data Exchange (ETDEWEB)

Lustbader, J.; Kreutzer, C.; Jeffers, M.; Adelman, S.; Yeakel, S.; Brontz, P.; Olson, K.; Ohlinger, J.

2014-02-01

Cab climate conditioning is one of the primary reasons for operating the main engine in a long-haul truck during driver rest periods. In the United States, sleeper cab trucks use approximately 667 million gallons of fuel annually for rest period idling. The U.S. Department of Energy's National Renewable Energy Laboratory's (NREL) CoolCab Project works closely with industry to design efficient thermal management systems for long-haul trucks that minimize engine idling and fuel use while maintaining occupant comfort. Heat transfer to the vehicle interior from opaque exterior surfaces is one of the major heat pathways that contribute to air conditioning loads during long-haul truck daytime rest period idling. To quantify the impact of paint color and the opportunity for advanced paints, NREL collaborated with Volvo Group North America, PPG Industries, and Dometic Environmental Corporation. Initial screening simulations using CoolCalc, NREL's rapid HVAC load estimation tool, showed promising air-conditioning load reductions due to paint color selection. Tests conducted at NREL's Vehicle Testing and Integration Facility using long-haul truck cab sections, 'test bucks,' showed a 31.1% of maximum possible reduction in rise over ambient temperature and a 20.8% reduction in daily electric air conditioning energy use by switching from black to white paint. Additionally, changing from blue to an advanced color-matched solar reflective blue paint resulted in a 7.3% reduction in daily electric air conditioning energy use for weather conditions tested in Colorado. National-level modeling results using weather data from major U.S. cities indicated that the increase in heating loads due to lighter paint colors is much smaller than the reduction in cooling loads.

Self-Management to Increase Safe Driving Among Short-Haul Truck Drivers

Science.gov (United States)

Hickman, Jeffrey S.; Geller, E. Scott

2005-01-01

The relative impact of a self-management for safety (SMS) process was evaluated at two short-haul trucking terminals. Participants in the Pre-Behavior group (n = 21) recorded their intentions to engage in specific safe versus at-risk driving behaviors before leaving the terminal (i.e., before making any of their deliveries for the day), whereas…

Battery Dimensioning and Life Cycle Costs Analysis for a Heavy-Duty Truck Considering the Requirements of Long-Haul Transportation

OpenAIRE

Mareev, Ivan; Becker, Jan Nicolas; Sauer, Dirk Uwe

2018-01-01

The use of heavy-duty battery electric trucks for long-haul transportation is challenging because of the required high energy amounts and thus the high capacity of traction batteries. Furthermore a high capacity battery implies high initial costs for the electric vehicle. This study investigates the required battery capacity for battery electric trucks considering the requirements of long-haul transportation in Germany and compares the life cycle costs of battery electric trucks and conventio...

Information rates of next-generation long-haul optical fiber systems using coded modulation

NARCIS (Netherlands)

Liga, G.; Alvarado, A.; Agrell, E.; Bayvel, P.

2017-01-01

A comprehensive study of the coded performance of long-haul spectrally-efficient WDM optical fiber transmission systems with different coded modulation decoding structures is presented. Achievable information rates are derived for three different square QAM formats and the optimal format is

Experimental log hauling through a traditional caribou wintering area

Directory of Open Access Journals (Sweden)

Harold G. Cumming

1998-03-01

Full Text Available A 3-year field experiment (fall 1990-spring 1993 showed that woodland caribou (Rangifer tarandus caribou altered their dispersion when logs were hauled through their traditional wintering area. Unlike observations in control years 1 and 3, radio-collared caribou that had returned to the study area before the road was plowed on January 6 of the experimental year 2, moved away 8-60 km after logging activities began. Seasonal migration to Lake Nipigon islands usually peaked in April, but by February 22 of year 2, 4 of the 6 had returned. The islands provide summer refuge from predation, but not when the lake is frozen. Tracks in snow showed that some caribou remained but changed locations. They used areas near the road preferentially in year 1, early year 2, and year 3, but moved away 2-5 km after the road was plowed in year 2. In a nearby undisturbed control area, no such changes occurred. Caribou and moose partitioned habitat on a small scale; tracks showed gray wolf (Canis lupus remote from caribou but close to moose tracks. No predation on caribou was observed within the wintering area; 2 kills were found outside it. Due to the possibility of displacing caribou from winter refugia to places with higher predation risk, log hauling through important caribou winter habitat should be minimized.

Locomotor diseases among male long-haul truck drivers and other professional drivers

DEFF Research Database (Denmark)

Jensen, Anker; Kaerlev, Linda; Tüchsen, Finn

2007-01-01

-249) and for other truck drivers (SHR: 130, 95% CI: 108-156) compared to bus drivers (SHR: 110, 95% CI: 79-149). All drivers had high SHR for lesions of the ulnar nerve (SHR: 159, 95% CI: 119-207), especially bus drivers (SHR: 197, 95% CI: 116-311). Long-haul truck drivers had high SHRs for synovitis and bursitis...

Development of an Effective Transport Media for Juvenile Spring Chinook Salmon to Mitigate Stress and Improve Smolt Survival During Columbia River Fish Hauling Operations, 1985 Final Report.

Energy Technology Data Exchange (ETDEWEB)

Wedemeyer, Gary A.

1985-02-01

Selected transport media consisting of mineral salt additions (Na/sup +/, Cl/sup -/, Ca/sup + +/, PO/sub 4//sup -3/, HCO/sub 3//sup -/, and Mg/sup + +/), mineral salts plus tranquilizing concentrations of tricaine methane sulfonate (MS-222), or MS-222 alone were tested for their ability to mitigate stress and increase smolt survival during single and mixed species hauling of Columbia River spring chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (Salmo gairdneri). Successful stress mitigation was afforded by several formulations as indicated by protection against life-threatening osmoregulatory and other physiological dysfunctions, and against immediate and delayed hauling mortality. Effects on the seawater survival and growth of smolts hauled in transport media were used as the overall criterion of success. Of the fourteen chemical formulations tested, 10 ppM MS-222 emerged as top-rated in terms of ability to mitigate physiological stress during single and mixed species transport of juvenile spring chinook salmon at hauling densities of 0.5 or 1.0 lb/gallon. Immediate and delayed mortalities from hauling stress were also reduced, but benefits to early marine growth and survival were limited to about the first month in seawater. The two physical factors tested (reduced light intensity and water temperature) were generally less effective than mineral salt additions in mitigating hauling stress, but the degree of protection afforded by reduced light intensity was nevertheless judged to be physiologically beneficial. 36 refs., 1 fig., 19 tabs.

Determinants of Safe and Productive Truck Driving: Empirical Evidence from Long-haul Cargo Transport

NARCIS (Netherlands)

de Vries, J.; de Koster, R.; Rijsdijk, S.; Roy, D.

2017-01-01

Using GPS data of 370 long-haul trips in India, survey data of 49 truck drivers, and ERP data, this study examines the role of driver personality characteristics in predicting risky and productive driving. The results show that more conscientious drivers display more risky driving behavior. More

Application of Sleeper Cab Thermal Management Technologies to Reduce Idle Climate Control Loads in Long-Haul Trucks

Energy Technology Data Exchange (ETDEWEB)

Lustbader, J. A.; Venson, T.; Adelman, S.; Dehart, C.; Yeakel, S.; Castillo, M. S.

2012-10-01

Each intercity long-haul truck in the U.S. idles approximately 1,800 hrs per year, primarily for sleeper cab hotel loads. Including workday idling, over 2 billion gallons of fuel are used annually for truck idling. NREL's CoolCab project works closely with industry to design efficient thermal management systems for long-haul trucks that keep the cab comfortable with minimized engine idling and fuel use. The impact of thermal load reduction technologies on idle reduction systems were characterized by conducting thermal soak tests, overall heat transfer tests, and 10-hour rest period A/C tests. Technologies evaluated include advanced insulation packages, a solar reflective film applied to the vehicle's opaque exterior surfaces, a truck featuring both film and insulation, and a battery-powered A/C system. Opportunities were identified to reduce heating and cooling loads for long-haul truck idling by 36% and 34%, respectively, which yielded a 23% reduction in battery pack capacity of the idle-reduction system. Data were also collected for development and validation of a CoolCalc HVAC truck cab model. CoolCalc is an easy-to-use, simplified, physics-based HVAC load estimation tool that requires no meshing, has flexible geometry, excludes unnecessary detail, and is less time-intensive than more detailed computer-aided engineering modeling approaches.

Functional requirements of the borrow area and haul route for the Waste Area Grouping projects at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Miller, D.G.

1992-09-01

This report describes the mission and functional requirements for the development of a borrow area and the associated haul route to support closure and/or remediation of Waste Area Grouping (WAG) 6 and other WAGs at Oak Ridge National Laboratory. This document specifies the basic functional requirements that must be met by the borrow area and haul route developed to produce low-permeability soil for the covers or caps at WAG 6

Hardware-efficient signal generation of layered/enhanced ACO-OFDM for short-haul fiber-optic links.

Science.gov (United States)

Wang, Qibing; Song, Binhuang; Corcoran, Bill; Boland, David; Zhu, Chen; Zhuang, Leimeng; Lowery, Arthur J

2017-06-12

Layered/enhanced ACO-OFDM is a promising candidate for intensity modulation and direct-detection based short-haul fiber-optic links due to its both power and spectral efficiency. In this paper, we firstly demonstrate a hardware-efficient real-time 9.375 Gb/s QPSK-encoded layered/enhanced asymmetrical clipped optical OFDM (L/E-ACO-OFDM) transmitter using a Virtex-6 FPGA. This L/E-ACO-OFDM signal is successfully transmitted over 20-km uncompensated standard single-mode fiber (S-SMF) using a directly modulated laser. Several methods are explored to reduce the FPGA's logic resource utilization by taking advantage of the L/E-ACO-OFDM's signal characteristics. We show that the logic resource occupation of L/E-ACO-OFDM transmitter is almost the same as that of DC-biased OFDM transmitter when they achieve the same spectral efficiency, proving its great potential to be used in a real-time short-haul optical transmission link.

Municipal consultation key to understanding haul road maintenance agreements for Saskatchewan rural municipalities

International Nuclear Information System (INIS)

Leibel, R.E.A.

1998-01-01

Current municipal perspectives regarding the oil and gas industry in Saskatchewan were described. Municipal jurisdiction and authority regarding road development and heavy haul road maintenance agreements were defined. Based on actual work experience, collaborative working relationships between the oil and gas industry and the municipal sector is well worth some industry time and effort since it will result in cost savings for the industry. In general, rural municipalities receive very limited tax benefits to recapture the costs of road reconstruction and maintenance caused by heavy industry traffic. Road servicing costs can be recaptured only if companies respect the weight limits, hauling regulations and road bans. On the whole, municipalities in Saskatchewan are favourably disposed towards the oil and gas industry, and have done well in the past to accommodate industry's needs. It is not unreasonable therefore to expect that industry show sensitivity to the impact of its activities on the local municipality, and does its level best to be on good terms with the municipalities through early two-way communication. Text of some relevant acts of the Legislature respecting the powers and authorities of rural municipalities are appended

Modelling the volatility in short and long haul Japanese tourist arrivals to New Zealand and Taiwan

NARCIS (Netherlands)

C-L. Chang (Chia-Lin); M.J. McAleer (Michael); C. Lim (Christine)

2010-01-01

textabstractThis paper estimates the effects of short and long haul volatility (or risk) in monthly Japanese tourist arrivals to Taiwan and New Zealand, respectively. In order to model appropriately the volatilities of international tourist arrivals, we use symmetric and asymmetric conditional

Modelling the Volatility in Short and Long Haul Japanese Tourist Arrivals to New Zealand and Taiwan

NARCIS (Netherlands)

C-L. Chang (Chia-Lin); M.J. McAleer (Michael); C. Lim (Christine)

2011-01-01

textabstractThis paper estimates the effects of short and long haul volatility (or risk) in monthly Japanese tourist arrivals to Taiwan and New Zealand, respectively. In order to model appropriately the volatilities of international tourist arrivals, we use symmetric and asymmetric conditional

Study of quiet turbofan STOL aircraft for short haul transportation

Science.gov (United States)

Higgins, T. P.; Stout, E. G.; Sweet, H. S.

1973-01-01

Conceptual designs of Quiet Turbofan STOL Short-Haul Transport Aircraft for the mid-1980 time period are developed and analyzed to determine their technical, operational, and economic feasibility. A matrix of aircraft using various high-lift systems and design parameters are considered. Variations in aircraft characteristics, airport geometry and location, and operational techniques are analyzed systematically to determine their effects on the market, operating economics, and community acceptance. In these studies, the total systems approach is considered to be critically important in analyzing the potential of STOL aircraft to reduce noise pollution and alleviate the increasing air corridor and airport congestion.

The use of cell phone network data in traffic data collection and long-haul truckshed (geographic extent) tracking.

Science.gov (United States)

2012-12-01

This study analyzed the potential of cell phone positioning techniques in freight truck data collection and long-haul : truckshed (geographic extent) tracking. Freight truck identification and tracking algorithms were developed by means of : cell pho...

Slow speed object detection for haul trucks

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-09-15

Caterpillar integrates radar technology with its current camera based system. Caterpillar has developed the Integrated Object Detection System, a slow speed object detection system for mining haul trucks. Object detection is a system that aids the truck operator's awareness of their surroundings. The system consists of a color touch screen display along with medium- and short-range radar as well as cameras, harnesses and mounting hardware. It is integrated into the truck's Work Area Vision System (WAVS). After field testing in 2007, system commercialization began in 2008. Prototype systems are in operation in Australia, Utah and Arizona and the Integrated Object Detection System will be available in the fourth quarter of 2009 and on production trucks 785C, 789C, 793D and 797B. The article is adapted from a presentation by Mark Richards of Caterpillar to the Haulage & Loading 2009 conference, May, held in Phoenix, AZ. 1 fig., 5 photos.

2050 Scenarios for Long-Haul Tourism in the Evolving Global Climate Change Regime

Directory of Open Access Journals (Sweden)

Jako Volschenk

2012-12-01

Full Text Available Tourism and its “midwife”, aviation, are transnational sectors exposed to global uncertainties. This scenario-building exercise considers a specific subset of these uncertainties, namely the impact of the evolving global climate change regime on long-haul tourism (LHT, with a 2050 horizon. The basic problematique is that unconstrained growth in aviation emissions will not be compatible with 2050 climate stabilisation goals, and that the stringency and timing of public policy interventions could have far-reaching impacts — either on the market for future growth of LHT, or the natural ecosystem on which tourism depends. Following an intuitive-logic approach to scenario-building, three meta-level scenarios that can be regarded as “possible” futures for the evolution of LHT are described. Two of these, i.e., the “grim reaper” and the “fallen angel” scenarios, are undesirable. The “green lantern” scenario represents the desired future. Long-haul tourist destinations should heed the early warning signals identified in the scenario narratives, and contribute towards realising the desired future. They should further guard against being passive victims if the feared scenarios materialise, by adapting, repositioning early upon reading the signposts, hedging against risks, and seizing new opportunities.

Cost characteristics of tilt-rotor, conventional air and high speed rail short-haul intercity passenger service

Science.gov (United States)

Schoendorfer, David L.; Morlok, Edward K.

1985-01-01

The cost analysis done to support an assessment of the potential for a small tilt-rotor aircraft to operate in short-haul intercity passenger service is described in detail. Anticipated costs of tilt-rotor air service were compared to the costs of two alternatives: conventional air and high speed rail (HSR). Costs were developed for corridor service, varying key market characteristics including distance, passenger volumes, and minimum frequency standards. The resulting cost vs output information can then be used to compare modal costs for essentially identical service quality and passenger volume or for different service levels and volumes for each mode, as appropriate. Extensive sensitivity analyses are performed. The cost-output features of these technologies are compared. Tilt-rotor is very attractive compared to HSR in terms of costs over the entire range of volume. It also has costs not dramatically different from conventional air, but tilt-rotor costs are generally higher. Thus some of its other advantages, such as the VTOL capability, must offset the cost disadvantage for it to be a preferred or competitive mode in any given market. These issues are addressed in the companion report which considers strategies for tilt-rotor development in commercial air service.

Air crew exposure on board of long-haul flights of the Belgian airlines

International Nuclear Information System (INIS)

Verhaegen, F.; Poffijn, A.

2000-01-01

New European radiation protection recommendations state that measures need to be taken for flight crew members whose annual radiation exposure exceeds 1 mSv. This will be the case for flight crew members who accumulate most of their flying hours on long-haul flights. The Recommendations for the Implementation of the Basic Safety Standards Directive states that for annual exposure levels between 1 and 6 mSv individual dose estimates should be obtained, whereas for annual exposures exceeding 6 mSv, which might rarely occur, record keeping with appropriate medical surveillance is recommended. To establish the exposure level of Belgian air crews, radiation measurements were performed on board of a total of 44 long-haul flights of the Belgian airlines. The contribution of low linear energy transfer (LET) radiation (photons, electrons, protons) was assessed by using TLD-700H detectors. The exposure to high-LET radiation (mostly neutrons) was measured with bubble detectors. Results were compared to calculations with an adapted version of the computer code CARI. For the low-LET radiation the calculations were found to be in good agreement with the measurements. The measurements of the neutron dose were consistently lower than the calculations. With the current flight schedules used by the Belgian airlines, air crew members are unlikely to receive annual doses exceeding 4 mSv. (author)

Impact of overnight traffic noise on sleep quality, sleepiness, and vigilant attention in long-haul truck drivers: Results of a pilot study

Directory of Open Access Journals (Sweden)

Roland FJ Popp

2015-01-01

Full Text Available This study aimed to evaluate the impact of traffic noise along the motorway on sleep quality, sleepiness, and vigilant attention in long-haul truck drivers. This was a randomized, crossover, within-subject controlled study. Healthy long-haul truck drivers spent 6 consecutive nights in a real truck berth with full sleep laboratory equipment. During 3 nights, subjects were exposed to replayed traffic noise alongside motorways, whereas the other 3 nights were without traffic noise. Polysomnography was recorded during the nights and numerous sleepiness tests and vigilance examinations were performed during the following standardized working day. Outcome measures were compared between noisy and silent nights using the paired Wilcoxon test. Ten healthy long-haul truck drivers with a mean age of 36.3 ± 7.3 years completed the study as planned. On noisy nights, subjects had greater latencies to the rapid eye movement (REM phase (90 ± 32 min vs 69 ± 16 min, P = 0.074 and higher percentages of sleep stage 1 (13.7 ± 5.5% vs 11.2 ± 4.4%; P = 0.059. Subjects also rated their sleep quality as having been better during nights without noise (28.1 ± 3.7 vs 30.3 ± 6.2, P = 0.092. The impact of these differences on daytime sleepiness and vigilance was rather low; however, mean Karolinska Sleepiness Scale (KSS scores measured during the course of the following day were higher on six out of eight occasions after noisy nights. The effects of overnight traffic noise on sleep quality are detectable but unlikely to have any major impact on the vigilant attention and driving performance of long haul-truck drivers with low nocturnal noise sensitivity. This might not be true for subgroups prone to sleeping disorders.

Impact of overnight traffic noise on sleep quality, sleepiness, and vigilant attention in long-haul truck drivers: Results of a pilot study.

Science.gov (United States)

Popp, Roland Fj; Maier, Stefanie; Rothe, Siegfried; Zulley, Jürgen; Crönlein, Tatjana; Wetter, Thomas C; Rupprecht, Rainer; Hajak, Göran

2015-01-01

This study aimed to evaluate the impact of traffic noise along the motorway on sleep quality, sleepiness, and vigilant attention in long-haul truck drivers. This was a randomized, crossover, within-subject controlled study. Healthy long-haul truck drivers spent 6 consecutive nights in a real truck berth with full sleep laboratory equipment. During 3 nights, subjects were exposed to replayed traffic noise alongside motorways, whereas the other 3 nights were without traffic noise. Polysomnography was recorded during the nights and numerous sleepiness tests and vigilance examinations were performed during the following standardized working day. Outcome measures were compared between noisy and silent nights using the paired Wilcoxon test. Ten healthy long-haul truck drivers with a mean age of 36.3 ± 7.3 years completed the study as planned. On noisy nights, subjects had greater latencies to the rapid eye movement (REM) phase (90 ± 32 min vs 69 ± 16 min, P = 0.074) and higher percentages of sleep stage 1 (13.7 ± 5.5% vs 11.2 ± 4.4%; P = 0.059). Subjects also rated their sleep quality as having been better during nights without noise (28.1 ± 3.7 vs 30.3 ± 6.2, P = 0.092). The impact of these differences on daytime sleepiness and vigilance was rather low; however, mean Karolinska Sleepiness Scale (KSS) scores measured during the course of the following day were higher on six out of eight occasions after noisy nights. The effects of overnight traffic noise on sleep quality are detectable but unlikely to have any major impact on the vigilant attention and driving performance of long haul-truck drivers with low nocturnal noise sensitivity. This might not be true for subgroups prone to sleeping disorders.

Reduction of the safety and health risk associated with the generation of dust on strip coal mine haul roads.

CSIR Research Space (South Africa)

Thompson, RJ

2000-01-01

Full Text Available mine haul roads. This would be used to identify suitable spray-on or mix-in surface treatments to reduce the generation of dust, within the constraints of cost effectiveness and maintainability, through consideration of wearing course material type...

Saltwater nectotizing fasciitis following coral reef laceration possibly exacerbated by a long-haul flight: a case report.

LENUS (Irish Health Repository)

Byrne, Ann-Maria

2009-01-01

INTRODUCTION: Necrotising fasciits is a rapidly progressive disease characterised by extensive necrosis of the fascia, skin, and subcutaneous tissue, with relative sparing of the underlying muscle. CASE PRESENTATION: We present the case of a 24-year old Irish male student who sustained a laceration to his right shin from contact with a coral reef while swimming in the Phuket region, off the west coast of Thailand. The following day, he returned to Ireland and presented with an aggressive and destructive variant of group A beta-hemolytic streptococcal necrotising fasciitis originating at the site of the coral reef injury, and exacerbated by the long-haul flight. He was successfully treated with aggressive surgical debridement, vacuum-assisted dressings, split skin grafting and broad spectrum antibiotics. CONCLUSION: Necrotising fasciitis can progress rapidly to systemic toxicity and even death without expedient diagnosis and aggressive treatment. Long-haul flights induce significant fluid accumulation in the lower extremity. These physiological fluid shifts may have contributed to the severity of our patient\\'s necrotizing condition following his flight from Thailand.

Effects of Self-Efficacy on Healthy Eating Depends on Normative Support: a Prospective Study of Long-Haul Truck Drivers.

Science.gov (United States)

Hamilton, Kyra; Hagger, Martin S

2018-04-01

Fruit and vegetable intake (FV) is insufficient in industrialized nations and there is excess of discretionary food choices (DC; foods high in fat, sugar, and salt). Long-haul truck drivers are considered a particularly at-risk group given the limited food choices and normatively reinforced eating habits at truck rest-stops. Self-efficacy and normative support are key determinants of eating behavior yet the processes underlying their effects on behavior are not well understood. We tested the direct and interactive effects of self-efficacy and normative support on healthy eating behaviors in long-haul truck drivers in a prospective correlational study. Long-haul truck drivers (N = 82) completed an initial survey containing self-report measures of behavioral intentions, perceived normative support, and self-efficacy for their FV and DC behaviors. Participants completed a follow-up survey 1 week later in which they self-reported their FV and DC behavior. A mediated moderation analysis identified an interactive effect of self-efficacy and normative support on behavior mediated by intention for FV and DC behavior. Specifically, we confirmed a compensation effect in which self-efficacy was more likely to have an effect on FV and DC behavior through intentions in participants with low normative support. Results indicate the importance of self-efficacy in predicting FV and DC intentions and behavior in the absence of a supportive normative environment. The compensatory effect of self-efficacy beliefs on behavior through intentions when normative support is low should be confirmed using experimental methods.

Performance Deterioration of Heavy-Haul Railway Bridges under Fatigue Loading Monitored by a Multisensor System

Directory of Open Access Journals (Sweden)

Zhiwu Yu

2018-01-01

Full Text Available Heavy-haul railway bridges play an increasingly essential role in the transportation in China due to the increasing transport volume. The performance deterioration of the scale models of a typical heavy-haul railway bridge under fatigue loading is monitored in this work, based on a multisensor system including the fiber-reinforced polymer optical fiber Bragg grating and electrical resistance strain gauges, linear variable displacement transducer, and accelerometer. Specifically, by monitoring/observing on the failure mode, fatigue life, load-midspan deflection response, material strain development, and so forth, this work develops an S-N model by comparing the relationship between fatigue life and rebar stress range with that between fatigue life and load level and proposes a damage evolution model considering the coupling of the stiffness degradation and inelastic deformation of specimens. It is found that the fatigue life of specimens is determined by the fatigue life of the rebar at the bottom and it may be lower than 2.0 million cycles with a 30-ton axle weight when environmental factors are taken into account. The predictions of the models agree well with experimental results. Therefore, this work furthers the understanding of the fatigue performance deterioration of the bridges by using a multisensor system.

Effect of hypobaric hypoxia, simulating conditions during long-haul air travel, on coagulation, fibrinolysis, platelet function, and endothelial activation

NARCIS (Netherlands)

Toff, William D.; Jones, Chris I.; Ford, Isobel; Pearse, Robert J.; Watson, Henry G.; Watt, Stephen J.; Ross, John A. S.; Gradwell, David P.; Batchelor, Anthony J.; Abrams, Keith R.; Meijers, Joost C. M.; Goodall, Alison H.; Greaves, Michael

2006-01-01

CONTEXT: The link between long-haul air travel and venous thromboembolism is the subject of continuing debate. It remains unclear whether the reduced cabin pressure and oxygen tension in the airplane cabin create an increased risk compared with seated immobility at ground level. OBJECTIVE: To

Photo-identification, site fidelity, and movement of female gray seals (Halichoerus grypus) between haul-outs in the Baltic Sea.

Science.gov (United States)

Karlsson, Olle; Hiby, Lex; Lundberg, Torkel; Jüssi, Mart; Jüssi, Ivar; Helander, Björn

2005-12-01

The growing gray seal population in the Baltic Sea has led to increased conflicts with fisheries. Despite limited data on gray seal ecology, management measures, such as culling, have been implemented recently. We studied movements and site fidelity of Baltic gray seals using mark-recapture analysis based on photographic identification of individuals (photo-id). Seals were photographed at the major summer haul-out sites. Profile photographs of the head and neck were matched using purpose-written software to generate a database of capture histories from 1995-2000. The haul-outs were grouped into seven areas. Darroch's method (20) for a two-sample capture-recapture census was adapted to estimate rates of movement between the areas. The majority of seals were estimated to remain within the same area, suggesting that Baltic gray seals exhibit a high degree of site fidelity during the summer, and that fidelity to a site lasts for more than one season.

Stress Response to Long Distance Transportation of Common Carp (Cyprinus carpio L.

Directory of Open Access Journals (Sweden)

R. Dobšíková

2006-01-01

Full Text Available The stress responses and changes in biochemical and haematological indices were investigated in three-year-old common carp (Cyprinus carpio L. during a long-distance transportation in special truck tanks. Twelve-hour transportation caused a significant increase in ammonia (p < 0.01, mean corpuscular volume MCV (p < 0.01, metamyelocytes ( p < 0.05 and band neutrophils (p < 0.01, and a significant decrease in Cl- (p < 0.05, lactate (p < 0.05, ALT (p < 0.05 and ALP (p < 0.01 levels. The values of LDH (p < 0.01, AST (p < 0.05, CK (p < 0.01 and haematocrit PCV (p < 0.05 were also significantly influenced by the transportation, but no time-dependent relation was found. On the contrary, the levels of cortisol, glucose and total protein in the biochemical profile, and the values of erythrocyte count (RBC, haemoglobin (Hb, mean corpuscular haemoglobin (MCH, mean corpuscular haemoglobin concentration (MCHC, leukocyte counts (WBC and leukogram (except for metamyelocytes and band neutrophils in the haematological profile were not significantly influenced by the transportation. Results showed that pre-transport fish manipulation (hauling, netting, handling, loading was found to be an important stressor for fish. Long-distance transportation itself was relatively considerate for the common carp tested.

INFLUENCE ANALYSIS OF ELASTIC DEFORMATIONS OF THE TRACK CABLE ON EFFORTS IN THE HAULING ROPE OF AERIAL ROPEWAY

Directory of Open Access Journals (Sweden)

S. V. Raksha

2013-10-01

Full Text Available Purpose. To estimate influence of elastic deformations of the track cable arising at movement of cars, on effort in a hauling rope of the aerial ropeway. Methodology. The method of consecutive approaches was used for research influence of elastic deformations of a track cable on effort in a hauling rope. Thus, definition of a tension of a track cable was carried out with use of the technique based on principles of modular configuration, the essence of which consists in formation of mathematical model by a combination of blocks of the formulas describing balance of the track cable on supports. Findings. The research has shown that influence of elastic deformations of a track cable on effort in a hauling rope was insignificant (less than 1 %. That points to possibility not to consider change of the track cable length, caused by its elastic properties, when modeling loading of elements of system «drive – traction rope – tension device». Also it has been found that use of the tension device of a track cable increased influence of its elastic properties on loading of rope system elements. At the same time the elastic component of the track cable tension in the test flight does not depend on a car position in the adjacent span, but only determines by the parameters of the rope system. Originality. The possibility of excluding the changes of track cable length caused by its elastic properties, when modeling loading of elements of system «drive – traction rope – tension device» was proved. Practical value. The use of these techniques and the results will simplify the mathematical model of loading of elements of the cable system and the system «drive – traction rope – tension device» as a whole.

Evaluation and modelling of haul road dust palliatives

Energy Technology Data Exchange (ETDEWEB)

Thompson, R.J.; Visser, A.T.

2000-07-01

Excessive dust generation from mine haul roads is a problem common to most surface coal mining operations. Optimal warning course material selection parameters reduce, but do not totally eliminate the potential to produce dust. For existing operations, which may not have optimally designed and maintained roads, the problem of identifying existing deficiencies, quantifying their impact and assigning priorities within the constraints of limited capital and manpower is problematic. This is reflected in the fact that most surface mine operators agree dust-free roads are desirable, but find it difficult to translate this into cost-effective betterment activities. This paper describes a dust palliative evaluation, management and costing strategy. Models are described which enable mines to assess the likely dustiness of their chosen wearing course materials as a function of surface loading of fines, traffic types and volume, together with various material parameters. These models are then combined with palliative suppression performance models to enable predictions to be made concerning the suppression- and cost-efficiency of various dust palliation options. 13 refs., 5 figs., 4 tabs.

Impact of short- compared to long-haul international travel on the sleep and wellbeing of national wheelchair basketball athletes.

Science.gov (United States)

Thornton, Heidi R; Miller, Joanna; Taylor, Lee; Sargent, Charli; Lastella, Michele; Fowler, Peter M

2018-07-01

Currently, very little is known about the impact of short- or long-haul air travel on the sleep and wellbeing of wheelchair basketball athletes. Eleven national wheelchair basketball athletes wore actigraphy monitors prior, during, and after air travel to the United Kingdom. Upon arrival, participants rated their subjective jet-lag, fatigue, and vigor. Individuals traveled to the United Kingdom from different locations in Australia, the United States, and Europe and were categorised according to travel length [LONG (up to 30.2 h) or SHORT (up to 6.5 h)]. Linear mixed models determined effects of travel length on sleep and subjective ratings of jet-lag, fatigue, and vigor. During competition, subjective fatigue and jet-lag were substantially higher (ES = 0.73; ±0.77) and (ES = 0.57; ±0.60), subjective vigor was lower (ES = 1.94; ±0.72), and get-up time was earlier (ES = 0.57; ±0.60) for LONG when compared to SHORT. Travelling greater distances by airplane had a larger effect on subjective ratings of jet-lag, fatigue and vigor, rather than sleep. Irrespective of travel group, sleep and subjective responses were compromised, reflecting the travel requirements, competition-mediated influences, and/or due to a change in environment.

Long-Haul Dense Space Division Multiplexed Transmission over Low-Crosstalk Heterogeneous 32-Core Transmission Line Using Partial Recirculating Loop System

DEFF Research Database (Denmark)

Mizuno, Takayuki; Shibahara, Kohki; Ye, Feihong

2017-01-01

In this paper, we present long-haul 32-core dense space division multiplexed (DSDM) unidirectional transmission over a single-mode multicore transmission line. We developed a low-crosstalk heterogeneous 32-core fiber with a square lattice arrangement, and a novel partial recirculating loop system...

Metal exposure and effects in voles and small birds near a mining haul road in Cape Krusenstern National Monument, Alaska.

Science.gov (United States)

Brumbaugh, William G; Mora, Miguel A; May, Thomas W; Phalen, David N

2010-11-01

Voles and small passerine birds were live-captured near the Delong Mountain Regional Transportation System (DMTS) haul road in Cape Krusenstern National Monument in northwest Alaska to assess metals exposure and sub-lethal biological effects. Similar numbers of animals were captured from a reference site in southern Cape Krusenstern National Monument for comparison. Histopathological examination of selected organs, and analysis of cadmium, lead, and zinc concentrations in liver and blood samples were performed. Voles and small birds captured from near the haul road had about 20 times greater blood and liver lead concentrations and about three times greater cadmium concentrations when compared to those from the reference site, but there were no differences in zinc tissue concentrations. One vole had moderate metastatic mineralization of kidney tissue, otherwise we observed no abnormalities in internal organs or DNA damage in the blood of any of the animals. The affected vole also had the greatest liver and blood Cd concentration, indicating that the lesion might have been caused by Cd exposure. Blood and liver lead concentrations in animals captured near the haul road were below concentrations that have been associated with adverse biological effects in other studies; however, subtle effects resulting from lead exposure, such as the suppression of the activity of certain enzymes, cannot be ruled out for some individual animals. Results from our 2006 reconnaissance-level study indicate that overall, voles and small birds obtained from near the DMTS road in Cape Krusenstern National Monument were not adversely affected by metals exposure; however, because of the small sample size and other uncertainties, continued monitoring of lead and cadmium in terrestrial habitats near the DMTS road is advised.

Battery Dimensioning and Life Cycle Costs Analysis for a Heavy-Duty Truck Considering the Requirements of Long-Haul Transportation

Directory of Open Access Journals (Sweden)

Ivan Mareev

2017-12-01

Full Text Available The use of heavy-duty battery electric trucks for long-haul transportation is challenging because of the required high energy amounts and thus the high capacity of traction batteries. Furthermore a high capacity battery implies high initial costs for the electric vehicle. This study investigates the required battery capacity for battery electric trucks considering the requirements of long-haul transportation in Germany and compares the life cycle costs of battery electric trucks and conventional diesel trucks in different transportation scenarios. The average consumption is simulated for different battery electric truck configurations on the main German highways and transportation scenarios incorporating battery charging during driver rest periods. The results show that in average case the required battery would restrict the payload to only 80% of a usual diesel truck payload that might be acceptable considering the statistical payload use. The life cycle costs in the examined scenarios also considering the charging infrastructure show that battery electric trucks can already perform on the same costs level as diesel trucks in certain scenarios.

Formation flying as an innovative air transportation system for long-haul commercial flight : A focus on operational feasibility and potential gain

NARCIS (Netherlands)

Herinckx, L.E.; Gutleb, T.L.M.; Van Nunen, R.; Van Rompuy, E.; Bos, D.A.; Dijkers, H.P.A.; De Wit, J.; Radfar, H.; Sahin, S.E.; Beelarts van Blokland, W.W.A.

2011-01-01

Formation flying is introduced as a new and innovative air transportation system for long-haul commercial flight. With this paper the operational feasibility of formation flying is addressed, both from a market demand and economic, as well as an air traffic control perspective. Preliminary results

Comments on the article by MM. R. Haul, H. Behnke, H. Dietrich 'die messung von gleichgewichtskonstanten des deuterium-aus-tausches zwischen schwefelwasserstoff und wasser'; Remarques sur l'article de MM. R. Haul, H. Behnke, H. Dietrich 'die messung von gleichgewichtskonstanten des deuterium-aus-tausches zwischen schwefelwasserstoff und wasser'

Energy Technology Data Exchange (ETDEWEB)

Grandcollot, P; Roth, E [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

MM. HAUL, BEHNKE and DIETRICH, having determined the isotopic exchange constant between water and hydrogen sulphide at 25 deg. C, obtain a value different from ours. A comparison of the techniques employed (these authors use a method of mass balance whilst we use a direct method) and of the isotopic analysis methods, and also our checks carried out from the spectrographic data, show that our determinations are appreciably more accurate. (author) [French] MM. HAUL, BEHNKE et DIETRICH, ayant determine la constante d'echange isotopique entre l'eau et l'hydrogene sulfure a 25 deg. C, obtiennent une valeur differente de la notre. La comparaison des modes operatoires (ces auteurs utilisent une methode par bilan alors que nous employons une methode directe) et des methodes d'analyse isotopique, ainsi que le controle que nous effectuons a partir des donnees spectrographiques, montrent que nos determinations sont notablement plus precises. (auteur)

29 CFR 1910.265 - Sawmills.

Science.gov (United States)

2010-07-01

... lumber. (27) Log haul. The term log haul means a conveyor for transferring logs to mill. (28) Package... be so designed and arranged that from no position on the rim of the chute shall the distance to the... unloading points. Pickup and unloading points and paths for lumber packages on conveyors and transfers and...

Long-Haul Truck Sleeper Heating Load Reduction Package for Rest Period Idling

Energy Technology Data Exchange (ETDEWEB)

Lustbader, Jason Aaron; Kekelia, Bidzina; Tomerlin, Jeff; Kreutzer, Cory J.; Yeakel, Skip; Adelman, Steven; Luo, Zhiming; Zehme, John

2016-04-05

Annual fuel use for sleeper cab truck rest period idling is estimated at 667 million gallons in the United States, or 6.8% of long-haul truck fuel use. Truck idling during a rest period represents zero freight efficiency and is largely done to supply accessory power for climate conditioning of the cab. The National Renewable Energy Laboratory's CoolCab project aims to reduce heating, ventilating, and air conditioning (HVAC) loads and resulting fuel use from rest period idling by working closely with industry to design efficient long-haul truck thermal management systems while maintaining occupant comfort. Enhancing the thermal performance of cab/sleepers will enable smaller, lighter, and more cost-effective idle reduction solutions. In addition, if the fuel savings provide a one- to three-year payback period, fleet owners will be economically motivated to incorporate them. For candidate idle reduction technologies to be implemented by original equipment manufacturers and fleets, their effectiveness must be quantified. To address this need, several promising candidate technologies were evaluated through experimentation and modeling to determine their effectiveness in reducing rest period HVAC loads. Load reduction strategies were grouped into the focus areas of solar envelope, occupant environment, conductive pathways, and efficient equipment. Technologies in each of these focus areas were investigated in collaboration with industry partners. The most promising of these technologies were then combined with the goal of exceeding a 30% reduction in HVAC loads. These technologies included 'ultra-white' paint, advanced insulation, and advanced curtain design. Previous testing showed more than a 35.7% reduction in air conditioning loads. This paper describes the overall heat transfer coefficient testing of this advanced load reduction technology package that showed more than a 43% reduction in heating load. Adding an additional layer of advanced insulation

Evaluation of four-dimensional nonbinary LDPC-coded modulation for next-generation long-haul optical transport networks.

Science.gov (United States)

Zhang, Yequn; Arabaci, Murat; Djordjevic, Ivan B

2012-04-09

Leveraging the advanced coherent optical communication technologies, this paper explores the feasibility of using four-dimensional (4D) nonbinary LDPC-coded modulation (4D-NB-LDPC-CM) schemes for long-haul transmission in future optical transport networks. In contrast to our previous works on 4D-NB-LDPC-CM which considered amplified spontaneous emission (ASE) noise as the dominant impairment, this paper undertakes transmission in a more realistic optical fiber transmission environment, taking into account impairments due to dispersion effects, nonlinear phase noise, Kerr nonlinearities, and stimulated Raman scattering in addition to ASE noise. We first reveal the advantages of using 4D modulation formats in LDPC-coded modulation instead of conventional two-dimensional (2D) modulation formats used with polarization-division multiplexing (PDM). Then we demonstrate that 4D LDPC-coded modulation schemes with nonbinary LDPC component codes significantly outperform not only their conventional PDM-2D counterparts but also the corresponding 4D bit-interleaved LDPC-coded modulation (4D-BI-LDPC-CM) schemes, which employ binary LDPC codes as component codes. We also show that the transmission reach improvement offered by the 4D-NB-LDPC-CM over 4D-BI-LDPC-CM increases as the underlying constellation size and hence the spectral efficiency of transmission increases. Our results suggest that 4D-NB-LDPC-CM can be an excellent candidate for long-haul transmission in next-generation optical networks.

Trends and individual differences in response to short-haul fight operations

Science.gov (United States)

Chidester, T. R.

1990-01-01

A survey of airline pilots was undertaken to determine normative patterns and individual differences in mood and sleep during short-haul flight operations. The results revealed that over the course of a typical 2-d trip, pilots experience a decline in positive mood, or activity, and an increase in negative mood, or tension. On layovers, pilots report experiencing sleep of shorter duration and poorer quality than at home. These patterns are very similar to those reported by Gander and Graeber and by Gander et al. using high-fidelity sleep and activity monitoring equipment. Examination of the impact of two personality dimensions extracted from the Jenkins Activity Survey measure of the Type A personality, Achievement Striving and Impatience/Irritability, suggested that Impatience/Irritability may serve as a marker of individuals most likely to experience health-related problems on trips. Achievement Striving may serve as a predictor of performance in crew settings.

Transient immune impairment after a simulated long-haul flight.

Science.gov (United States)

Wilder-Smith, Annelies; Mustafa, Fatima B; Peng, Chung Mien; Earnest, Arul; Koh, David; Lin, Gen; Hossain, Iqbal; MacAry, Paul A

2012-04-01

Almost 2 billion people travel aboard commercial airlines every year, with about 20% developing symptoms of the common cold within 1 wk after air travel. We hypothesize that hypobaric hypoxic conditions associated with air travel may contribute to immune impairment. We studied the effects of hypobaric hypoxic conditions during a simulated flight at 8000 ft (2438 m) cruising altitude on immune and stress markers in 52 healthy volunteers (mean age 31) before and on days 1, 4, and 7 after the flight. We did a cohort study using a generalized estimating equation to examine the differences in the repeated measures. Our findings show that the hypobaric hypoxic conditions of a 10-h overnight simulation flight are not associated with severe immune impairment or abnormal IgA or cortisol levels, but with transient impairment in some parameters: we observed a transient decrease in lymphocyte proliferative responses combined with an upregulation in CD69 and CD14 cells and a decrease in HLA-DR in the immediate days following the simulated flight that normalized by day 7 in most instances. These transient immune changes may contribute to an increased susceptibility to respiratory infections commonly seen after long-haul flights.

Study of short haul high-density V/STOL transportation systems, volume 1

Science.gov (United States)

Solomon, H. L.

1972-01-01

The relative advantages of STOL aircraft concepts were examined by simulating the operations of a short haul high-density intercity STOL system set in two arenas, the California corridor and the Chicago-Detroit-Cleveland triangle, during the 1980 time period. The study was constrained to the use of three aircraft concepts designated as the deflected slipstream turboprop, externally blown flap, and augmentor wing turbofan configurations. The projected demographic, economic, travel demand, and travel characteristics of the representative arenas were identified. The STOL airline operating scenarios were then formulated and through the use of the aerospace modal split simulation program, the traveler modal choices involving alternative STOL concepts were estimated in the context of the total transportation environment for 1980. System combinations that presented the best potential for economic return and traveler acceptance were then identified for each STOL concept.

Trends and individual differences in response to short-haul flight operations

Science.gov (United States)

Chidester, Thomas R.

1990-01-01

A survey of airline pilots was undertaken to determine normative patterns and individual differences in mood and sleep during short-haul flight operations. The results revealed that over the course of a typical 2-d trip, pilots experience a decline in positive mood, or activity, and an increase in negative mood, or tension. On layovers, pilots report experiencing sleep of shorter duration and poorer quality than at home. These patterns are very similar to those reported by Gander and Graeber (1987) and by Gander et al. (1988), using high-fidelity sleep and activity monitoring equipment. Examination of the impact of two personality dimensions extracted from the Jenkins Activity Survey measure of the Type A personality, Achievement Striving and Impatience/Irritability, suggested that Impatience/Irritability may serve as a marker of individuals most likely to experience health-related problems on trips. Achievement Striving may serve as a predictor of performance in crew settings.

Unintentional stoppages of trucks hauling high-level nuclear waste in Nevada

International Nuclear Information System (INIS)

Glickman, T.S.

1991-01-01

Any unintentional stoppage of trucks hauling high-level nuclear waste in Nevada could intensify public concerns about the negative impacts of the Yucca Mountain Project. This paper provides estimates of the expected number and frequency of such stoppages under several alternative scenarios for the routing and volume of the anticipated truck shipments. At least twice as many truck stoppages are expected to occur on freeways as on non-freeways, and at least twice as many are expected to occur in rural areas as in other areas. The expected frequency of such stoppages in the state is estimated to range from about 3 per year to one every 3 1/2 years. About one in every 4 of the stoppages is expected to take place in Las Vegas and 3 out of every 4 are expected to be non-accidents such as mechanical disablements. The minimum duration of the stoppages is expected to be on the order of half an hour for disablements and an hour for accidents

Quiet Clean Short-haul Experimental Engine (QCSEE): The aerodynamic and mechanical design of the QCSEE under-the-wing fan

Science.gov (United States)

1977-01-01

The design, fabrication, and testing of two experimental high bypass geared turbofan engines and propulsion systems for short haul passenger aircraft are described. The aerodynamic and mechanical design of a variable pitch 1.34 pressure ratio fan for the under the wing (UTW) engine are included. The UTW fan was designed to permit rotation of the 18 composite fan blades into the reverse thrust mode of operation through both flat pitch and stall pitch directions.

Long-Haul Truck Sleeper Heating Load Reduction Package for Rest Period Idling: Preprint

Energy Technology Data Exchange (ETDEWEB)

Lustbader, Jason; Kekelia, Bidzina; Tomerlin, Jeff; Kreutzer, Cory; Adelman, Steve; Yeakel, Skip; Luo, Zhiming; Zehme, John

2016-03-24

Annual fuel use for sleeper cab truck rest period idling is estimated at 667 million gallons in the United States, or 6.8% of long-haul truck fuel use. Truck idling during a rest period represents zero freight efficiency and is largely done to supply accessory power for climate conditioning of the cab. The National Renewable Energy Laboratory's CoolCab project aims to reduce heating, ventilating, and air conditioning (HVAC) loads and resulting fuel use from rest period idling by working closely with industry to design efficient long-haul truck thermal management systems while maintaining occupant comfort. Enhancing the thermal performance of cab/sleepers will enable smaller, lighter, and more cost-effective idle reduction solutions. In addition, if the fuel savings provide a one- to three-year payback period, fleet owners will be economically motivated to incorporate them. For candidate idle reduction technologies to be implemented by original equipment manufacturers and fleets, their effectiveness must be quantified. To address this need, several promising candidate technologies were evaluated through experimentation and modeling to determine their effectiveness in reducing rest period HVAC loads. Load reduction strategies were grouped into the focus areas of solar envelope, occupant environment, conductive pathways, and efficient equipment. Technologies in each of these focus areas were investigated in collaboration with industry partners. The most promising of these technologies were then combined with the goal of exceeding a 30% reduction in HVAC loads. These technologies included 'ultra-white' paint, advanced insulation, and advanced curtain design. Previous testing showed more than a 35.7% reduction in air conditioning loads. This paper describes the overall heat transfer coefficient testing of this advanced load reduction technology package that showed more than a 43% reduction in heating load. Adding an additional layer of advanced insulation

Airsickness and aircraft motion during short-haul flights.

Science.gov (United States)

Turner, M; Griffin, M J; Holland, I

2000-12-01

There is little quantitative information that can be used to predict the incidence of airsickness from the motions experienced in military or civil aviation. This study examines the relationship between low-frequency aircraft motion and passenger sickness in short-haul turboprop flights within the United Kingdom. A questionnaire survey of 923 fare-paying passengers was conducted on 38 commercial airline flights. Concurrent measurements of aircraft motion were made on all journeys, yielding approximately 30 h of aircraft motion data. Overall, 0.5% of passengers reported vomiting, 8.4% reported nausea (range 0% to 34.8%) and 16.2% reported illness (range 0% to 47.8%) during flight. Positive correlations were found between the percentage of passengers who experienced nausea or felt ill and the magnitude of low-frequency lateral and vertical motion, although neither motion uniquely predicted airsickness. The incidence of motion sickness also varied with passenger age, gender, food consumption and activity during air travel. No differences in sickness were found between passengers located in different seating sections of the aircraft, or as a function of moderate levels of alcohol consumption. The passenger responses suggest that a useful prediction of airsickness can be obtained from magnitudes of low frequency aircraft motion. However, some variations in airsickness may also be explained by individual differences between passengers and their psychological perception of flying.

Representing distance, consuming distance

DEFF Research Database (Denmark)

Larsen, Gunvor Riber

Title: Representing Distance, Consuming Distance Abstract: Distance is a condition for corporeal and virtual mobilities, for desired and actual travel, but yet it has received relatively little attention as a theoretical entity in its own right. Understandings of and assumptions about distance...... are being consumed in the contemporary society, in the same way as places, media, cultures and status are being consumed (Urry 1995, Featherstone 2007). An exploration of distance and its representations through contemporary consumption theory could expose what role distance plays in forming...

Modal shifts in short-haul passenger travel and the consequent energy impacts. [Intercity travel under 500 miles

Energy Technology Data Exchange (ETDEWEB)

1980-03-01

A study was performed to evaluate the impacts of strategies to effect modal shifts in short-haul passenger travel (defined herein as intercity travel under 500 miles) from energy-intensive modes to those modes that are less energy-intensive. A series of individual strategies, ranging from incentives to the less energy-intensive modes (bus, rail) to penalties to the more energy-intensive modes (auto, air) was examined to determine energy saved and policy implications relative to strategy implementation. The most effective of the individual strategies were then combined in all permutations, and the analysis was repeated. As part of the analytical process, effects of factors other than energy (user cost and time, emissions, government subsidy, and travel fatailities) were examined in a benefit/cost analysis. Finally, energy savings, benefit/cost impacts, implementation considerations, and policy implications were evaluated to arrive at conclusions as to the effectiveness of the more-influential strategies and to the overall effectiveness of induced modal shifts. The principal conclusion of the study is that the maximum 1980 energy saving that might be realized by modal shifts, discounting the concurrent effects of demand suppression and improvement of mode efficiency, is approximately 83 x 10/sup 12/ Btu (46,500 bbl gasoline per day), 3.8% of the total projected 1980 energy consumption in the short-haul transportation sector and 0.23% of the total US petroleum use. It was also concluded that strategies to achieve these small savings by modal shifts would result in significant economic, social, and business disruptions.

Vibration Monitoring of a Large Scale Heavy Haul Railway Viaduct

Directory of Open Access Journals (Sweden)

Busatta Fulvio

2015-01-01

Full Text Available In South Africa, heavy haul railway transport was introduced in the mid-1970s for the Iron Ore and the Coal Export lines. In recent decades, the expansion of existing mines, new markets and the competition of iron ore- and coal-exporting countries have led owners and operators to progressively increase the capacity of the export lines. On the one hand, operational efficiencies have been improved; on the other hand, a significant increase of the rail traffic has been experienced. Thus, bridges along the export lines are now crossed by heavier and longer trains with more frequent train passages than in the past. Increasing train loading might lead to significant consequences on structures such as dynamic amplifications and reduction of service life due to fatigue. Hence dynamic assessment and monitoring of the structural condition of bridges under actual train loading are becoming more relevant to support decision making processes. The paper presents the investigations carried out on the Olifants River Viaduct, a critical structure along the Iron Ore Export Line, in order to implement a state-of-the-art vibration monitoring system.

Coexistence of enhanced mobile broadband communications and ultra-reliable low-latency communications in mobile front-haul

Science.gov (United States)

Ying, Kai; Kowalski, John M.; Nogami, Toshizo; Yin, Zhanping; Sheng, Jia

2018-01-01

5G systems are supposed to support coexistence of multiple services such as ultra reliable low latency communications (URLLC) and enhanced mobile broadband (eMBB) communications. The target of eMBB communications is to meet the high-throughput requirement while URLLC are used for some high priority services. Due to the sporadic nature and low latency requirement, URLLC transmission may pre-empt the resource of eMBB transmission. Our work is to analyze the URLLC impact on eMBB transmission in mobile front-haul. Then, some solutions are proposed to guarantee the reliability/latency requirements for URLLC services and minimize the impact to eMBB services at the same time.

DISTANCES TO DARK CLOUDS: COMPARING EXTINCTION DISTANCES TO MASER PARALLAX DISTANCES

International Nuclear Information System (INIS)

Foster, Jonathan B.; Jackson, James M.; Stead, Joseph J.; Hoare, Melvin G.; Benjamin, Robert A.

2012-01-01

We test two different methods of using near-infrared extinction to estimate distances to dark clouds in the first quadrant of the Galaxy using large near-infrared (Two Micron All Sky Survey and UKIRT Infrared Deep Sky Survey) surveys. Very long baseline interferometry parallax measurements of masers around massive young stars provide the most direct and bias-free measurement of the distance to these dark clouds. We compare the extinction distance estimates to these maser parallax distances. We also compare these distances to kinematic distances, including recent re-calibrations of the Galactic rotation curve. The extinction distance methods agree with the maser parallax distances (within the errors) between 66% and 100% of the time (depending on method and input survey) and between 85% and 100% of the time outside of the crowded Galactic center. Although the sample size is small, extinction distance methods reproduce maser parallax distances better than kinematic distances; furthermore, extinction distance methods do not suffer from the kinematic distance ambiguity. This validation gives us confidence that these extinction methods may be extended to additional dark clouds where maser parallaxes are not available.

Locomotive Schedule Optimization for Da-qin Heavy Haul Railway

Directory of Open Access Journals (Sweden)

Ruiye Su

2015-01-01

Full Text Available The main difference between locomotive schedule of heavy haul railways and that of regular rail transportation is the number of locomotives utilized for one train. One heavy-loaded train usually has more than one locomotive, but a regular train only has one. This paper develops an optimization model for the multilocomotive scheduling problem (MLSP through analyzing the current locomotive schedule of Da-qin Railway. The objective function of our paper is to minimize the total number of utilized locomotives. The MLSP is nondeterministic polynomial (NP hard. Therefore, we convert the multilocomotive traction problem into a single-locomotive traction problem. Then, the single-locomotive traction problem (SLTP can be converted into an assignment problem. The Hungarian algorithm is applied to solve the model and obtain the optimal locomotive schedule. We use the variance of detention time of locomotives at stations to evaluate the stability of locomotive schedule. In order to evaluate the effectiveness of the proposed optimization model, case studies for 20 kt and 30 kt heavy-loaded combined trains on Da-qin Railway are both conducted. Compared to the current schedules, the optimal schedules from the proposed models can save 62 and 47 locomotives for 20 kt and 30 kt heavy-loaded combined trains, respectively. Therefore, the effectiveness of the proposed model and its solution algorithm are both valid.

US long-haul truck driver work organization and the association with cardiometabolic disease risk.

Science.gov (United States)

Hege, Adam; Lemke, Michael Kenneth; Apostolopoulos, Yorghos; Perko, Mike; Sönmez, Sevil; Strack, Robert

2017-09-03

Work organization, including long working hours, irregular work schedules, and job stress, has been associated with increased cardiometabolic disease (CMD) risk for numerous working populations. The purpose of this study was to examine the associations between work hours, work schedules, job stress, and CMD risk for a sample of US long-haul truck drivers (LHTDs). A nonexperimental, descriptive, cross-sectional design was employed to collect survey and anthropometric data from 260 US LHTDs at a major truck stop. The mean BMI was 33.40 kg/m 2 and mean waist circumference was 114.77 cm. Using logistic regression, researchers found longer work hours, especially greater than 11 hours daily, were associated with increased odds for an extremely high risk of CMD. Results support comprehensive and integrated approaches that address work organization, and in particular long working hours, to reduce drivers' CMD risk.

An optimization model for collection, haul, transfer, treatment and disposal of infectious medical waste: Application to a Greek region.

Science.gov (United States)

Mantzaras, Gerasimos; Voudrias, Evangelos A

2017-11-01

The objective of this work was to develop an optimization model to minimize the cost of a collection, haul, transfer, treatment and disposal system for infectious medical waste (IMW). The model calculates the optimum locations of the treatment facilities and transfer stations, their design capacities (t/d), the number and capacities of all waste collection, transport and transfer vehicles and their optimum transport path and the minimum IMW management system cost. Waste production nodes (hospitals, healthcare centers, peripheral health offices, private clinics and physicians in private practice) and their IMW production rates were specified and used as model inputs. The candidate locations of the treatment facilities, transfer stations and sanitary landfills were designated, using a GIS-based methodology. Specifically, Mapinfo software with exclusion criteria for non-appropriate areas was used for siting candidate locations for the construction of the treatment plant and calculating the distance and travel time of all possible vehicle routes. The objective function was a non-linear equation, which minimized the total collection, transport, treatment and disposal cost. Total cost comprised capital and operation costs for: (1) treatment plant, (2) waste transfer stations, (3) waste transport and transfer vehicles and (4) waste collection bins and hospital boxes. Binary variables were used to decide whether a treatment plant and/or a transfer station should be constructed and whether a collection route between two or more nodes should be followed. Microsoft excel software was used as installation platform of the optimization model. For the execution of the optimization routine, two completely different software were used and the results were compared, thus, resulting in higher reliability and validity of the results. The first software was Evolver, which is based on the use of genetic algorithms. The second one was Crystal Ball, which is based on Monte Carlo

0-6613 : evaluate binder and mixture aging for warm mix asphalt.

Science.gov (United States)

2013-08-01

Warm mix asphalt (WMA) technologies employ reduced : mixing and placement temperatures, thereby allowing : reduced fuel consumption, enhanced compaction, : increased haul distances, and an extended paving : season. However, there have been issues of ...

Hauled liquid waste as a pollutant of soils and waters in Poland

Directory of Open Access Journals (Sweden)

Karczmarczyk Agnieszka

2016-06-01

Full Text Available Hauled liquid waste as a pollutant of soils and waters in Poland. Improperly maintained holding tanks are often underestimated source of contamination of soil, groundwater and surface water. As a rule, wastewater stored in holding tanks, should be transported and treated in municipal wastewater treatment plants (WWTPs. There are 2,257,000 holding tanks in Poland, located mainly in rural areas. The article presents the results of analysis of wastewater management in 20 rural and urban-rural communes, which were chosen at random from the total number of 2,174 communes in Poland. The only criterion of commune selection was total or partial lack of sewerage system. Analysis of the collected data showed that on average only 27% of liquid waste from holding tanks ended at the WWTPs. The median is even lower and amounts to 17.5%. More than 4,000 Mg of P and 26,000 Mg of N is dispersed in the environment in uncontrolled manner. Those diffuse point sources of pollution may be one of the reasons in the difficulty of achieving of good ecological status of rivers and affect the quality of the Baltic Sea.

Transmission system for distribution of video over long-haul optical point-to-point links using a microwave photonic filter in the frequency range of 0.01-10 GHz

Science.gov (United States)

Zaldívar Huerta, Ignacio E.; Pérez Montaña, Diego F.; Nava, Pablo Hernández; Juárez, Alejandro García; Asomoza, Jorge Rodríguez; Leal Cruz, Ana L.

2013-12-01

We experimentally demonstrate the use of an electro-optical transmission system for distribution of video over long-haul optical point-to-point links using a microwave photonic filter in the frequency range of 0.01-10 GHz. The frequency response of the microwave photonic filter consists of four band-pass windows centered at frequencies that can be tailored to the function of the spectral free range of the optical source, the chromatic dispersion parameter of the optical fiber used, as well as the length of the optical link. In particular, filtering effect is obtained by the interaction of an externally modulated multimode laser diode emitting at 1.5 μm associated to the length of a dispersive optical fiber. Filtered microwave signals are used as electrical carriers to transmit TV-signal over long-haul optical links point-to-point. Transmission of TV-signal coded on the microwave band-pass windows located at 4.62, 6.86, 4.0 and 6.0 GHz are achieved over optical links of 25.25 km and 28.25 km, respectively. Practical applications for this approach lie in the field of the FTTH access network for distribution of services as video, voice, and data.

Counts of Alaska Steller sea lion adult and juvenile (non-pup) conducted on rookeries and haul-outs in Alaska Aleutian Islands, Bering Sea, and others from 1904-01-01 to 2015-07-18 (NCEI Accession 0128190)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains counts of adult and juvenile (non-pup) Steller sea lions on rookeries and haul-outs in Alaska made between 1904 and 2015. Non-pup counts have...

Happiness and limits to sustainable tourism mobility: a new conceptual model

NARCIS (Netherlands)

Ram, Y.; Nawijn, J.; Peeters, P.M.

2013-01-01

Current leisure mobility patterns are not sustainable. Because energy efficiency measures appear insufficient to accommodate predicted future volume growth, changes in transportation modes and volume are needed. Short-haul should be the preferred distance, public transportation the preferred mode

MCDA APPLIED TO PERFORMANCE APPRAISAL OF SHORT-HAUL TRUCK DRIVERS: A CASE STUDY IN A PORTUGUESE TRUCKING COMPANY

Directory of Open Access Journals (Sweden)

Raquel Morte

2015-03-01

Full Text Available Performance appraisal increasingly assumes a more important role in any organizational environment. In the trucking industry, drivers are the company's image and for this reason it is important to develop and increase their performance and commitment to the company's goals. This paper aims to create a performance appraisal model for trucking drivers, based on a multi-criteria decision aid methodology. The PROMETHEE and MMASSI methodologies were adapted using the criteria used for performance appraisal by the trucking company studied. The appraisal involved all the truck drivers, their supervisors and the company's Managing Director. The final output is a ranking of the drivers, based on their performance, for each one of the scenarios used. The results are to be used as a decision-making tool to allocate drivers to the domestic haul service.

PERBANDINGAN EUCLIDEAN DISTANCE DENGAN CANBERRA DISTANCE PADA FACE RECOGNITION

Directory of Open Access Journals (Sweden)

Sendhy Rachmat Wurdianarto

2014-08-01

Full Text Available Perkembangan ilmu pada dunia komputer sangatlah pesat. Salah satu yang menandai hal ini adalah ilmu komputer telah merambah pada dunia biometrik. Arti biometrik sendiri adalah karakter-karakter manusia yang dapat digunakan untuk membedakan antara orang yang satu dengan yang lainnya. Salah satu pemanfaatan karakter / organ tubuh pada setiap manusia yang digunakan untuk identifikasi (pengenalan adalah dengan memanfaatkan wajah. Dari permasalahan diatas dalam pengenalan lebih tentang aplikasi Matlab pada Face Recognation menggunakan metode Euclidean Distance dan Canberra Distance. Model pengembangan aplikasi yang digunakan adalah model waterfall. Model waterfall beriisi rangkaian aktivitas proses yang disajikan dalam proses analisa kebutuhan, desain menggunakan UML (Unified Modeling Language, inputan objek gambar diproses menggunakan Euclidean Distance dan Canberra Distance. Kesimpulan yang dapat ditarik adalah aplikasi face Recognation menggunakan metode euclidean Distance dan Canverra Distance terdapat kelebihan dan kekurangan masing-masing. Untuk kedepannya aplikasi tersebut dapat dikembangkan dengan menggunakan objek berupa video ataupun objek lainnya.   Kata kunci : Euclidean Distance, Face Recognition, Biometrik, Canberra Distance

Research on Navigation Path Planning for An Underground Load Haul Dump

Directory of Open Access Journals (Sweden)

Qi Yulong

2015-11-01

Full Text Available The improved A * algorithm is a method of navigation path planning for articulated underground scrapers. Firstly, an environment model based on a mining Geographic Information System (GIS map is established, and then combined with improved A * algorithm, the underground global path planning problem of the intelligent Load Haul Dump (LHD is solved. In this paper, for the articulated structure, the method of expanding nodes by articulation angle is adopted to make expanded nodes meet the trajectory characteristics. In addition, collision threat cost is introduced in the evaluation function to avoid collisions between the LHD and the tunnel walls. As peran analysis of the simulation test to verify the effectiveness of the improved A * algorithm and a comparison with the traditional A * algorithm, the improved A * algorithm can enhance search efficiency. Acontrast of multiple sets of test parameters suggests that when the price weighted coefficient of collision is 0.2, the shortest path can be derived to avoid impact. Finally, tracking results indicate that the proposed algorithm for navigation path planning can maintain the tracking error to within 0.2 m in line with the structural characteristics of the scraper in the laboratory environment to realize the path planning of unmanned scrapers and trajectory tracking. Moreover, the algorithm can enhance the safety of scrapers and prevent roadway collisions. The feasibility and practicality of the proposed method is verified in this work.

On state estimation and fusion with elliptical constraints

Energy Technology Data Exchange (ETDEWEB)

Rao, Nageswara S. [ORNL; Liu, Qiang [ORNL

2017-11-01

We consider tracking of a target with elliptical nonlinear constraints on its motion dynamics. The state estimates are generated by sensors and sent over long-haul links to a remote fusion center for fusion. We show that the constraints can be projected onto the known ellipse and hence incorporated into the estimation and fusion process. In particular, two methods based on (i) direct connection to the center, and (ii) shortest distance to the ellipse are discussed. A tracking example is used to illustrate the tracking performance using projection-based methods with various fusers in the lossy long-haul tracking environment.

Catch of pelagic hauls in Mediterranean acoustic surveys: Is it the same between day and night?

Directory of Open Access Journals (Sweden)

Athanassios Machias

2013-03-01

Full Text Available Fish sampling is a critical aspect of acoustic surveys, because it is directly related to the “transformation” of echo into species biomass and subsequently affects the accuracy of acoustic estimates. In the present study, we investigated the differences between day and night sampling in a the catch composition through certain diversity indices and b the length frequency distribution of anchovy and sardine using catch data of pelagic hauls collected from four different regions of the European Mediterranean waters. In addition, the possible bias in trawl efficiency due to sampling time and the possible error introduced in acoustic estimates were investigated. No statistically significant differences were found between day and night in any of the parameters examined. The results showed that a more flexible strategy can be adopted to reduce the duration and the cost of acoustic sampling for small pelagic species. The advantages and disadvantages of the two sampling strategies are discussed.

Encyclopedia of distances

CERN Document Server

Deza, Michel Marie

2016-01-01

This 4th edition of the leading reference volume on distance metrics is characterized by updated and rewritten sections on some items suggested by experts and readers, as well a general streamlining of content and the addition of essential new topics. Though the structure remains unchanged, the new edition also explores recent advances in the use of distances and metrics for e.g. generalized distances, probability theory, graph theory, coding theory, data analysis. New topics in the purely mathematical sections include e.g. the Vitanyi multiset-metric, algebraic point-conic distance, triangular ratio metric, Rossi-Hamming metric, Taneja distance, spectral semimetric between graphs, channel metrization, and Maryland bridge distance. The multidisciplinary sections have also been supplemented with new topics, including: dynamic time wrapping distance, memory distance, allometry, atmospheric depth, elliptic orbit distance, VLBI distance measurements, the astronomical system of units, and walkability distance. Lea...

Distance Learning

National Research Council Canada - National Science Library

Braddock, Joseph

1997-01-01

A study reviewing the existing Army Distance Learning Plan (ADLP) and current Distance Learning practices, with a focus on the Army's training and educational challenges and the benefits of applying Distance Learning techniques...

Development of ergonomics audits for bagging, haul truck and maintenance and repair operations in mining.

Science.gov (United States)

Dempsey, Patrick G; Pollard, Jonisha; Porter, William L; Mayton, Alan; Heberger, John R; Gallagher, Sean; Reardon, Leanna; Drury, Colin G

2017-12-01

The development and testing of ergonomics and safety audits for small and bulk bag filling, haul truck and maintenance and repair operations in coal preparation and mineral processing plants found at surface mine sites is described. The content for the audits was derived from diverse sources of information on ergonomics and safety deficiencies including: analysis of injury, illness and fatality data and reports; task analysis; empirical laboratory studies of particular tasks; field studies and observations at mine sites; and maintenance records. These diverse sources of information were utilised to establish construct validity of the modular audits that were developed for use by mine safety personnel. User and interrater reliability testing was carried out prior to finalising the audits. The audits can be implemented using downloadable paper versions or with a free mobile NIOSH-developed Android application called ErgoMine. Practitioner Summary: The methodology used to develop ergonomics audits for three types of mining operations is described. Various sources of audit content are compared and contrasted to serve as a guide for developing ergonomics audits for other occupational contexts.

REPRESENTATIONS OF DISTANCE: DIFFERENCES IN UNDERSTANDING DISTANCE ACCORDING TO TRAVEL METHOD

Directory of Open Access Journals (Sweden)

Gunvor Riber Larsen

2017-12-01

Full Text Available This paper explores how Danish tourists represent distance in relation to their holiday mobility and how these representations of distance are a result of being aero-mobile as opposed to being land-mobile. Based on interviews with Danish tourists, whose holiday mobility ranges from the European continent to global destinations, the first part of this qualitative study identifies three categories of representations of distance that show how distance is being ‘translated’ by the tourists into non-geometric forms: distance as resources, distance as accessibility, and distance as knowledge. The representations of distance articulated by the Danish tourists show that distance is often not viewed in ‘just’ kilometres. Rather, it is understood in forms that express how transcending the physical distance through holiday mobility is dependent on individual social and economic contexts, and on whether the journey was undertaken by air or land. The analysis also shows that being aeromobile is the holiday transportation mode that removes the tourists the furthest away from physical distance, resulting in the distance travelled by air being represented in ways that have the least correlation, in the tourists’ minds, with physical distance measured in kilometres.

Energy usage optimisation of heavy haul freight trains

CSIR Research Space (South Africa)

Bogaers, Alfred

2016-10-01

Full Text Available tonnage and long distances an enormous amount of energy is required. Using classical mechanics, an energy usage model for typical freight trains based on available tractive power and typical rolling stock resistances (curvature, friction, gravity etc...

Characteristics of Loads of Cattle Stopping for Feed, Water and Rest during Long-Distance Transport in Canada

Directory of Open Access Journals (Sweden)

Hannah E. Flint

2014-03-01

Full Text Available This study is the first comprehensive examination of long-haul cattle being transported across Canada and off-loaded for feed, water and rest. A total of 129 truckloads were observed at one of two commercial rest stations near Thunder Bay, Ontario. Data collected included information regarding the truck driver, the trailer, the trip, the animals and animal handling. The majority of the loads stopping were feeder calves (60.94% while 21.09% were weaned calves, and the remaining 14.84% were market weight cattle. The truck loads surveyed were in transit for, on average, 28.2 ± 5.0 hours before stopping and cattle were rested for an average of 11.2 ± 2.8 hours. These data suggest that loads stopping at the rest station were adhering to the regulations stated in the Health of Animals Act, which outline a maximum of 48 hours in transit before a mandatory stop of at least 5 hours for feed, water and rest. There was a large amount of variability around how well recommendations, such as stocking density were followed. Further research is required to assess how well cattle are coping with long-distance transport under current regulations and industry practices.

Encyclopedia of distances

CERN Document Server

Deza, Michel Marie

2014-01-01

This updated and revised third edition of the leading reference volume on distance metrics includes new items from very active research areas in the use of distances and metrics such as geometry, graph theory, probability theory and analysis. Among the new topics included are, for example, polyhedral metric space, nearness matrix problems, distances between belief assignments, distance-related animal settings, diamond-cutting distances, natural units of length, Heidegger’s de-severance distance, and brain distances. The publication of this volume coincides with intensifying research efforts into metric spaces and especially distance design for applications. Accurate metrics have become a crucial goal in computational biology, image analysis, speech recognition and information retrieval. Leaving aside the practical questions that arise during the selection of a ‘good’ distance function, this work focuses on providing the research community with an invaluable comprehensive listing of the main available di...

Data assimilation in the minerals industry : Real-time updating of spatial models using online production data

NARCIS (Netherlands)

Wambeke, T.

2018-01-01

Declining ore grades, extraction at greater depths and longer hauling distances put pressure on maturing mines. Not enough new mines will be commissioned on time to compensate for the resulting shortages. Ore-body replacement rates are relatively low due to a reduced appetite for exploration.

2 x 344 Tb/s Propagation-direction Interleaved Transmission over 1500-km MCF Enhanced by Multicarrier Full Electric-field Digital Back-propagation

DEFF Research Database (Denmark)

Kobayashi, T.; Takara, H.; Sano, A.

2013-01-01

We demonstrate 12-core fiber bidirectional long-haul transmission with sub-petabit-class capacity (2 × 344 Tb/s). Inter-core crosstalk management and multicarrier nonlinear compensation enabled the longest distance of 1500 km in SDM transmission with unidirectional capacity over 300 Tb/s....

Interface Simulation Distances

Directory of Open Access Journals (Sweden)

Pavol Černý

2012-10-01

Full Text Available The classical (boolean notion of refinement for behavioral interfaces of system components is the alternating refinement preorder. In this paper, we define a distance for interfaces, called interface simulation distance. It makes the alternating refinement preorder quantitative by, intuitively, tolerating errors (while counting them in the alternating simulation game. We show that the interface simulation distance satisfies the triangle inequality, that the distance between two interfaces does not increase under parallel composition with a third interface, and that the distance between two interfaces can be bounded from above and below by distances between abstractions of the two interfaces. We illustrate the framework, and the properties of the distances under composition of interfaces, with two case studies.

Two lighter than air systems in opposing flight regimes: An unmanned short haul, heavy load transport balloon and a manned, light payload airship

Science.gov (United States)

Pohl, R. A.

1975-01-01

Lighter Than Air vehicles are generally defined or categorized by the shape of the balloon, payload capacity and operational flight regime. Two balloon systems that are classed as being in opposite categories are described. One is a cable guided, helium filled, short haul, heavy load transport Lighter Than Air system with a natural shaped envelope. The other is a manned, aerodynamic shaped airship which utilizes hot air as the buoyancy medium and is in the light payload class. While the airship is in the design/fabrication phase with flight tests scheduled for the latter part of 1974, the transport balloon system has been operational for some eight years.

Cultural Resource Investigations for a Multipurpose Haul Road on the Idaho National Laboratory

Energy Technology Data Exchange (ETDEWEB)

Brenda R. Pace; Cameron Brizzee; Hollie Gilbert; Clayton Marler; Julie Braun Williams

2010-08-01

The U. S. Department of Energy, Idaho Operations Office is considering options for construction of a multipurpose haul road to transport materials and wastes between the Materials and Fuels Complex (MFC) and other Idaho National Laboratory (INL) Site facilities. The proposed road will be closed to the public and designed for limited year-round use. Two primary options are under consideration: a new route south of the existing T-25 power line road and an upgrade to road T-24. In the Spring of 2010, archaeological field surveys and initial coordination and field reconnaissance with representatives from the Shoshone-Bannock Tribes were completed to identify any resources that may be adversely affected by the proposed road construction and to develop recommendations to protect any listed or eligible for listing on the National Register of Historic Places. The investigations showed that 24 archaeological resources and one historic marker are located in the area of potential effects for road construction and operation south of the T-25 powerline road and 27archaeological resources are located in the area of potential effects for road construction and operation along road T-24. Generalized tribal concerns regarding protection of natural resources were also documented in both road corridors. This report outlines recommendations for additional investigations and protective measures that can be implemented to minimize adverse impacts to the identified resources.

Reducing the distance in distance-caregiving by technology innovation

Directory of Open Access Journals (Sweden)

Lazelle E Benefield

2007-07-01

Full Text Available Lazelle E Benefield1, Cornelia Beck21College of Nursing, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA; 2Pat & Willard Walker Family Memory Research Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USAAbstract: Family caregivers are responsible for the home care of over 34 million older adults in the United States. For many, the elder family member lives more than an hour’s distance away. Distance caregiving is a growing alternative to more familiar models where: 1 the elder and the family caregiver(s may reside in the same household; or 2 the family caregiver may live nearby but not in the same household as the elder. The distance caregiving model involves elders and their family caregivers who live at some distance, defined as more than a 60-minute commute, from one another. Evidence suggests that distance caregiving is a distinct phenomenon, differs substantially from on-site family caregiving, and requires additional assistance to support the physical, social, and contextual dimensions of the caregiving process. Technology-based assists could virtually connect the caregiver and elder and provide strong support that addresses the elder’s physical, social, cognitive, and/or sensory impairments. Therefore, in today’s era of high technology, it is surprising that so few affordable innovations are being marketed for distance caregiving. This article addresses distance caregiving, proposes the use of technology innovation to support caregiving, and suggests a research agenda to better inform policy decisions related to the unique needs of this situation.Keywords: caregiving, family, distance, technology, elders

Censoring distances based on labeled cortical distance maps in cortical morphometry.

Science.gov (United States)

Ceyhan, Elvan; Nishino, Tomoyuki; Alexopolous, Dimitrios; Todd, Richard D; Botteron, Kelly N; Miller, Michael I; Ratnanather, J Tilak

2013-01-01

It has been demonstrated that shape differences in cortical structures may be manifested in neuropsychiatric disorders. Such morphometric differences can be measured by labeled cortical distance mapping (LCDM) which characterizes the morphometry of the laminar cortical mantle of cortical structures. LCDM data consist of signed/labeled distances of gray matter (GM) voxels with respect to GM/white matter (WM) surface. Volumes and other summary measures for each subject and the pooled distances can help determine the morphometric differences between diagnostic groups, however they do not reveal all the morphometric information contained in LCDM distances. To extract more information from LCDM data, censoring of the pooled distances is introduced for each diagnostic group where the range of LCDM distances is partitioned at a fixed increment size; and at each censoring step, the distances not exceeding the censoring distance are kept. Censored LCDM distances inherit the advantages of the pooled distances but also provide information about the location of morphometric differences which cannot be obtained from the pooled distances. However, at each step, the censored distances aggregate, which might confound the results. The influence of data aggregation is investigated with an extensive Monte Carlo simulation analysis and it is demonstrated that this influence is negligible. As an illustrative example, GM of ventral medial prefrontal cortices (VMPFCs) of subjects with major depressive disorder (MDD), subjects at high risk (HR) of MDD, and healthy control (Ctrl) subjects are used. A significant reduction in laminar thickness of the VMPFC in MDD and HR subjects is observed compared to Ctrl subjects. Moreover, the GM LCDM distances (i.e., locations with respect to the GM/WM surface) for which these differences start to occur are determined. The methodology is also applicable to LCDM-based morphometric measures of other cortical structures affected by disease.

Censoring Distances Based on Labeled Cortical Distance Maps in Cortical Morphometry

Directory of Open Access Journals (Sweden)

Elvan eCeyhan

2013-10-01

Full Text Available It has been demonstrated that shape differences are manifested in cortical structures due to neuropsychiatric disorders. Such morphometric differences can be measured by labeled cortical distance mapping (LCDM which characterizes the morphometry of the laminar cortical mantle of cortical structures. LCDM data consist of signed/labeled distances of gray matter (GM voxels with respect to GM/white matter (WM surface. Volumes and other summary measures for each subject and the pooled distances can help determine the morphometric differences between diagnostic groups, however they do not reveal all the morphometric information con-tained in LCDM distances. To extract more information from LCDM data, censoring of the pooled distances is introduced for each diagnostic group where the range of LCDM distances is partitioned at a fixed increment size; and at each censoring step, the distances not exceeding the censoring distance are kept. Censored LCDM distances inherit the advantages of the pooled distances but also provide information about the location of morphometric differences which cannot be obtained from the pooled distances. However, at each step, the censored distances aggregate, which might confound the results. The influence of data aggregation is investigated with an extensive Monte Carlo simulation analysis and it is demonstrated that this influence is negligible. As an illustrative example, GM of ventral medial prefrontal cortices (VMPFCs of subjects with major depressive disorder (MDD, subjects at high risk (HR of MDD, and healthy control (Ctrl subjects are used. A significant reduction in laminar thickness of the VMPFC in MDD and HR subjects is observed compared to Ctrl subjects. Moreover, the GM LCDM distances (i.e., locations with respect to the GM/WM surface for which these differences start to occur are determined. The methodology is also applicable to LCDM-based morphometric measures of other cortical structures affected by disease.

Training for Distance Teaching through Distance Learning.

Science.gov (United States)

Cadorath, Jill; Harris, Simon; Encinas, Fatima

2002-01-01

Describes a mixed-mode bachelor degree course in English language teaching at the Universidad Autonoma de Puebla (Mexico) that was designed to help practicing teachers write appropriate distance education materials by giving them the experience of being distance students. Includes a course outline and results of a course evaluation. (Author/LRW)

Tourists consuming distance

DEFF Research Database (Denmark)

Larsen, Gunvor Riber

The environmental impact of tourism mobility is linked to the distances travelled in order to reach a holiday destination, and with tourists travelling more and further than previously, an understanding of how the tourists view the distance they travel across becomes relevant. Based on interviews...... contribute to an understanding of how it is possible to change tourism travel behaviour towards becoming more sustainable. How tourists 'consume distance' is discussed, from the practical level of actually driving the car or sitting in the air plane, to the symbolic consumption of distance that occurs when...... travelling on holiday becomes part of a lifestyle and a social positioning game. Further, different types of tourist distance consumers are identified, ranging from the reluctant to the deliberate and nonchalant distance consumers, who display very differing attitudes towards the distance they all travel...

Analytic processing of distance.

Science.gov (United States)

Dopkins, Stephen; Galyer, Darin

2018-01-01

How does a human observer extract from the distance between two frontal points the component corresponding to an axis of a rectangular reference frame? To find out we had participants classify pairs of small circles, varying on the horizontal and vertical axes of a computer screen, in terms of the horizontal distance between them. A response signal controlled response time. The error rate depended on the irrelevant vertical as well as the relevant horizontal distance between the test circles with the relevant distance effect being larger than the irrelevant distance effect. The results implied that the horizontal distance between the test circles was imperfectly extracted from the overall distance between them. The results supported an account, derived from the Exemplar Based Random Walk model (Nosofsky & Palmieri, 1997), under which distance classification is based on the overall distance between the test circles, with relevant distance being extracted from overall distance to the extent that the relevant and irrelevant axes are differentially weighted so as to reduce the contribution of irrelevant distance to overall distance. The results did not support an account, derived from the General Recognition Theory (Ashby & Maddox, 1994), under which distance classification is based on the relevant distance between the test circles, with the irrelevant distance effect arising because a test circle's perceived location on the relevant axis depends on its location on the irrelevant axis, and with relevant distance being extracted from overall distance to the extent that this dependency is absent. Copyright © 2017 Elsevier B.V. All rights reserved.

Distancing, not embracing, the Distancing-Embracing model of art reception.

Science.gov (United States)

Davies, Stephen

2017-01-01

Despite denials in the target article, the Distancing-Embracing model appeals to compensatory ideas in explaining the appeal of artworks that elicit negative affect. The model also appeals to the deflationary effects of psychological distancing. Having pointed to the famous rejection in the 1960s of the view that aesthetic experience involves psychological distancing, I suggest that "distance" functions here as a weak metaphor that cannot sustain the explanatory burden the theory demands of it.

Foundations of Distance Education. Third Edition. Routledge Studies in Distance Education.

Science.gov (United States)

Keegan, Desmond

This text gives an overview of distance education for students, administrators, and practitioners in distance education. Chapter 1 discusses the study of distance education. Chapter 2 analyzes forms of nonconventional education (open, nontraditional) that may have similarities to distance education but are not to be identified with it. Chapter 3…

modelling distances

Directory of Open Access Journals (Sweden)

Robert F. Love

2001-01-01

Full Text Available Distance predicting functions may be used in a variety of applications for estimating travel distances between points. To evaluate the accuracy of a distance predicting function and to determine its parameters, a goodness-of-fit criteria is employed. AD (Absolute Deviations, SD (Squared Deviations and NAD (Normalized Absolute Deviations are the three criteria that are mostly employed in practice. In the literature some assumptions have been made about the properties of each criterion. In this paper, we present statistical analyses performed to compare the three criteria from different perspectives. For this purpose, we employ the ℓkpθ-norm as the distance predicting function, and statistically compare the three criteria by using normalized absolute prediction error distributions in seventeen geographical regions. We find that there exist no significant differences between the criteria. However, since the criterion SD has desirable properties in terms of distance modelling procedures, we suggest its use in practice.

Study of short-haul aircraft operating economics. Phase 2: an analysis of the impact of jet modernization on local service airline operating costs. Final report

Energy Technology Data Exchange (ETDEWEB)

Andrastek, D.A.

1976-05-01

The objectives of this phase of the study were (1) to assess the 10 year operating cost trends of the local service airlines operating in the 1965 through 1974 period, (2) to glean from these trends the technological and operational parameters which were impacted most significantly by the transition to newer pure jet, short haul transports, and effected by changing fuel prices and cost of living indices, and (3) to develop, construct, and evaluate an operating cost forecasting model which would incorporate those factors which best predicted airline total operating cost behavior over that 10-year period.

Spatial variation in foraging behaviour of a marine top predator (Phoca vitulina determined by a large-scale satellite tagging program.

Directory of Open Access Journals (Sweden)

Ruth J Sharples

Full Text Available The harbour seal (Phoca vitulina is a widespread marine predator in Northern Hemisphere waters. British populations have been subject to rapid declines in recent years. Food supply or inter-specific competition may be implicated but basic ecological data are lacking and there are few studies of harbour seal foraging distribution and habits. In this study, satellite tagging conducted at the major seal haul outs around the British Isles showed both that seal movements were highly variable among individuals and that foraging strategy appears to be specialized within particular regions. We investigated whether these apparent differences could be explained by individual level factors: by modelling measures of trip duration and distance travelled as a function of size, sex and body condition. However, these were not found to be good predictors of foraging trip duration or distance, which instead was best predicted by tagging region, time of year and inter-trip duration. Therefore, we propose that local habitat conditions and the constraints they impose are the major determinants of foraging movements. Specifically the distance to profitable feeding grounds from suitable haul-out locations may dictate foraging strategy and behaviour. Accounting for proximity to productive foraging resources is likely to be an important component of understanding population processes. Despite more extensive offshore movements than expected, there was also marked fidelity to the local haul-out region with limited connectivity between study regions. These empirical observations of regional exchange at short time scales demonstrates the value of large scale electronic tagging programs for robust characterization of at-sea foraging behaviour at a wide spatial scale.

Brownian distance covariance

OpenAIRE

Székely, Gábor J.; Rizzo, Maria L.

2010-01-01

Distance correlation is a new class of multivariate dependence coefficients applicable to random vectors of arbitrary and not necessarily equal dimension. Distance covariance and distance correlation are analogous to product-moment covariance and correlation, but generalize and extend these classical bivariate measures of dependence. Distance correlation characterizes independence: it is zero if and only if the random vectors are independent. The notion of covariance with...

Traversing psychological distance.

Science.gov (United States)

Liberman, Nira; Trope, Yaacov

2014-07-01

Traversing psychological distance involves going beyond direct experience, and includes planning, perspective taking, and contemplating counterfactuals. Consistent with this view, temporal, spatial, and social distances as well as hypotheticality are associated, affect each other, and are inferred from one another. Moreover, traversing all distances involves the use of abstraction, which we define as forming a belief about the substitutability for a specific purpose of subjectively distinct objects. Indeed, across many instances of both abstraction and psychological distancing, more abstract constructs are used for more distal objects. Here, we describe the implications of this relation for prediction, choice, communication, negotiation, and self-control. We ask whether traversing distance is a general mental ability and whether distance should replace expectancy in expected-utility theories. Copyright © 2014 Elsevier Ltd. All rights reserved.

Open and Distance Learning Today. Routledge Studies in Distance Education Series.

Science.gov (United States)

Lockwood, Fred, Ed.

This book contains the following papers on open and distance learning today: "Preface" (Daniel); "Big Bang Theory in Distance Education" (Hawkridge); "Practical Agenda for Theorists of Distance Education" (Perraton); "Trends, Directions and Needs: A View from Developing Countries" (Koul); "American…

From a distance: implications of spontaneous self-distancing for adaptive self-reflection.

Science.gov (United States)

Ayduk, Ozlem; Kross, Ethan

2010-05-01

Although recent experimental work indicates that self-distancing facilitates adaptive self-reflection, it remains unclear (a) whether spontaneous self-distancing leads to similar adaptive outcomes, (b) how spontaneous self-distancing relates to avoidance, and (c) how this strategy impacts interpersonal behavior. Three studies examined these issues demonstrating that the more participants spontaneously self-distanced while reflecting on negative memories, the less emotional (Studies 1-3) and cardiovascular (Study 2) reactivity they displayed in the short term. Spontaneous self-distancing was also associated with lower emotional reactivity and intrusive ideation over time (Study 1). The negative association between spontaneous self-distancing and emotional reactivity was mediated by how participants construed their experience (i.e., less recounting relative to reconstruing) rather than avoidance (Studies 1-2). In addition, spontaneous self-distancing was associated with more problem-solving behavior and less reciprocation of negativity during conflicts among couples in ongoing relationships (Study 3). Although spontaneous self-distancing was empirically related to trait rumination, it explained unique variance in predicting key outcomes. 2010 APA, all rights reserved

Distance-regular graphs

NARCIS (Netherlands)

van Dam, Edwin R.; Koolen, Jack H.; Tanaka, Hajime

2016-01-01

This is a survey of distance-regular graphs. We present an introduction to distance-regular graphs for the reader who is unfamiliar with the subject, and then give an overview of some developments in the area of distance-regular graphs since the monograph 'BCN'[Brouwer, A.E., Cohen, A.M., Neumaier,

Hierarchical traits distances explain grassland Fabaceae species' ecological niches distances

Science.gov (United States)

Fort, Florian; Jouany, Claire; Cruz, Pablo

2015-01-01

Fabaceae species play a key role in ecosystem functioning through their capacity to fix atmospheric nitrogen via their symbiosis with Rhizobium bacteria. To increase benefits of using Fabaceae in agricultural systems, it is necessary to find ways to evaluate species or genotypes having potential adaptations to sub-optimal growth conditions. We evaluated the relevance of phylogenetic distance, absolute trait distance and hierarchical trait distance for comparing the adaptation of 13 grassland Fabaceae species to different habitats, i.e., ecological niches. We measured a wide range of functional traits (root traits, leaf traits, and whole plant traits) in these species. Species phylogenetic and ecological distances were assessed from a species-level phylogenetic tree and species' ecological indicator values, respectively. We demonstrated that differences in ecological niches between grassland Fabaceae species were related more to their hierarchical trait distances than to their phylogenetic distances. We showed that grassland Fabaceae functional traits tend to converge among species with the same ecological requirements. Species with acquisitive root strategies (thin roots, shallow root systems) are competitive species adapted to non-stressful meadows, while conservative ones (coarse roots, deep root systems) are able to tolerate stressful continental climates. In contrast, acquisitive species appeared to be able to tolerate low soil-P availability, while conservative ones need high P availability. Finally we highlight that traits converge along the ecological gradient, providing the assumption that species with similar root-trait values are better able to coexist, regardless of their phylogenetic distance. PMID:25741353

Hierarchical traits distances explain grassland Fabaceae species’ ecological niches distances

Directory of Open Access Journals (Sweden)

Florian eFort

2015-02-01

Full Text Available Fabaceae species play a key role in ecosystem functioning through their capacity to fix atmospheric nitrogen via their symbiosis with Rhizobium bacteria. To increase benefits of using Fabaceae in agricultural systems, it is necessary to find ways to evaluate species or genotypes having potential adaptations to sub-optimal growth conditions. We evaluated the relevance of phylogenetic distance, absolute trait distance and hierarchical trait distance for comparing the adaptation of 13 grassland Fabaceae species to different habitats, i.e. ecological niches. We measured a wide range of functional traits (root traits, leaf traits and whole plant traits in these species. Species phylogenetic and ecological distances were assessed from a species-level phylogenetic tree and species’ ecological indicator values, respectively. We demonstrated that differences in ecological niches between grassland Fabaceae species were related more to their hierarchical trait distances than to their phylogenetic distances. We showed that grassland Fabaceae functional traits tend to converge among species with the same ecological requirements. Species with acquisitive root strategies (thin roots, shallow root systems are competitive species adapted to non-stressful meadows, while conservative ones (coarse roots, deep root systems are able to tolerate stressful continental climates. In contrast, acquisitive species appeared to be able to tolerate low soil-P availability, while conservative ones need high P availability. Finally we highlight that traits converge along the ecological gradient, providing the assumption that species with similar root-trait values are better able to coexist, regardless of their phylogenetic distance.

Numerical distance protection

CERN Document Server

Ziegler, Gerhard

2011-01-01

Distance protection provides the basis for network protection in transmission systems and meshed distribution systems. This book covers the fundamentals of distance protection and the special features of numerical technology. The emphasis is placed on the application of numerical distance relays in distribution and transmission systems.This book is aimed at students and engineers who wish to familiarise themselves with the subject of power system protection, as well as the experienced user, entering the area of numerical distance protection. Furthermore it serves as a reference guide for s

The Distance Standard Deviation

OpenAIRE

Edelmann, Dominic; Richards, Donald; Vogel, Daniel

2017-01-01

The distance standard deviation, which arises in distance correlation analysis of multivariate data, is studied as a measure of spread. New representations for the distance standard deviation are obtained in terms of Gini's mean difference and in terms of the moments of spacings of order statistics. Inequalities for the distance variance are derived, proving that the distance standard deviation is bounded above by the classical standard deviation and by Gini's mean difference. Further, it is ...

Distance Education in Turkey

Directory of Open Access Journals (Sweden)

Dr. Nursel Selver RUZGAR,

2004-04-01

Full Text Available Distance Education in Turkey Assistant Professor Dr. Nursel Selver RUZGAR Technical Education Faculty Marmara University, TURKEY ABSTRACT Many countries of the world are using distance education with various ways, by internet, by post and by TV. In this work, development of distance education in Turkey has been presented from the beginning. After discussing types and applications for different levels of distance education in Turkey, the distance education was given in the cultural aspect of the view. Then, in order to create the tendencies and thoughts of graduates of Higher Education Institutions and Distance Education Institutions about being competitors in job markets, sufficiency of education level, advantages for education system, continuing education in different Institutions, a face-to-face survey was applied to 1284 graduates, 958 from Higher Education Institutions and 326 from Distance Education Institutions. The results were evaluated and discussed. In the last part of this work, suggestions to become widespread and improve the distance education in the country were made.

Haptic Discrimination of Distance

Science.gov (United States)

van Beek, Femke E.; Bergmann Tiest, Wouter M.; Kappers, Astrid M. L.

2014-01-01

While quite some research has focussed on the accuracy of haptic perception of distance, information on the precision of haptic perception of distance is still scarce, particularly regarding distances perceived by making arm movements. In this study, eight conditions were measured to answer four main questions, which are: what is the influence of reference distance, movement axis, perceptual mode (active or passive) and stimulus type on the precision of this kind of distance perception? A discrimination experiment was performed with twelve participants. The participants were presented with two distances, using either a haptic device or a real stimulus. Participants compared the distances by moving their hand from a start to an end position. They were then asked to judge which of the distances was the longer, from which the discrimination threshold was determined for each participant and condition. The precision was influenced by reference distance. No effect of movement axis was found. The precision was higher for active than for passive movements and it was a bit lower for real stimuli than for rendered stimuli, but it was not affected by adding cutaneous information. Overall, the Weber fraction for the active perception of a distance of 25 or 35 cm was about 11% for all cardinal axes. The recorded position data suggest that participants, in order to be able to judge which distance was the longer, tried to produce similar speed profiles in both movements. This knowledge could be useful in the design of haptic devices. PMID:25116638

Haptic discrimination of distance.

Directory of Open Access Journals (Sweden)

Femke E van Beek

Full Text Available While quite some research has focussed on the accuracy of haptic perception of distance, information on the precision of haptic perception of distance is still scarce, particularly regarding distances perceived by making arm movements. In this study, eight conditions were measured to answer four main questions, which are: what is the influence of reference distance, movement axis, perceptual mode (active or passive and stimulus type on the precision of this kind of distance perception? A discrimination experiment was performed with twelve participants. The participants were presented with two distances, using either a haptic device or a real stimulus. Participants compared the distances by moving their hand from a start to an end position. They were then asked to judge which of the distances was the longer, from which the discrimination threshold was determined for each participant and condition. The precision was influenced by reference distance. No effect of movement axis was found. The precision was higher for active than for passive movements and it was a bit lower for real stimuli than for rendered stimuli, but it was not affected by adding cutaneous information. Overall, the Weber fraction for the active perception of a distance of 25 or 35 cm was about 11% for all cardinal axes. The recorded position data suggest that participants, in order to be able to judge which distance was the longer, tried to produce similar speed profiles in both movements. This knowledge could be useful in the design of haptic devices.

Impact of product mix and markets on the economic feasibility of hardwood thinning

Science.gov (United States)

John E. Baumgras; Chris B. LeDoux

1989-01-01

Results demonstrate how the economic feasibility of commercial hardwood thinning is impacted by tree diameter, product mix, and primary product markets. These results indicate that multiproduct harvesting can increase revenues by $0.01/ft³ to $0.32/ft³; and that small shifts in price levels or haul distance can postpone commercial thinning...

Dispersion-optimized optical fiber for high-speed long-haul dense wavelength division multiplexing transmission

Science.gov (United States)

Wu, Jindong; Chen, Liuhua; Li, Qingguo; Wu, Wenwen; Sun, Keyuan; Wu, Xingkun

2011-07-01

Four non-zero-dispersion-shifted fibers with almost the same large effective area (Aeff) and optimized dispersion properties are realized by novel index profile designing and modified vapor axial deposition and modified chemical vapor deposition processes. An Aeff of greater than 71 μm2 is obtained for the designed fibers. Three of the developed fibers with positive dispersion are improved by reducing the 1550nm dispersion slope from 0.072ps/nm2/km to 0.063ps/nm2/km or 0.05ps/nm2/km, increasing the 1550nm dispersion from 4.972ps/nm/km to 5.679ps/nm/km or 7.776ps/nm/km, and shifting the zero-dispersion wavelength from 1500nm to 1450nm. One of these fibers is in good agreement with G655D and G.656 fibers simultaneously, and another one with G655E and G.656 fibers; both fibers are beneficial to high-bit long-haul dense wavelength division multiplexing systems over S-, C-, and L-bands. The fourth developed fiber with negative dispersion is also improved by reducing the 1550nm dispersion slope from 0.12ps/nm2/km to 0.085ps/nm2/km, increasing the 1550nm dispersion from -4ps/nm/km to -6.016ps/nm/km, providing facilities for a submarine transmission system. Experimental measurements indicate that the developed fibers all have excellent optical transmission and good macrobending and splice performances.

Impact of trucking network flow on preferred biorefinery locations in the southern United States

Science.gov (United States)

Timothy M. Young; Lee D. Han; James H. Perdue; Stephanie R. Hargrove; Frank M. Guess; Xia Huang; Chung-Hao Chen

2017-01-01

The impact of the trucking transportation network flow was modeled for the southern United States. The study addresses a gap in existing research by applying a Bayesian logistic regression and Geographic Information System (GIS) geospatial analysis to predict biorefinery site locations. A one-way trucking cost assuming a 128.8 km (80-mile) haul distance was estimated...

Distancing from experienced self: how global-versus-local perception affects estimation of psychological distance.

Science.gov (United States)

Liberman, Nira; Förster, Jens

2009-08-01

In 4 studies, the authors examined the prediction derived from construal level theory (CLT) that higher level of perceptual construal would enhance estimated egocentric psychological distance. The authors primed participants with global perception, local perception, or both (the control condition). Relative to the control condition, global processing made participants estimate larger psychological distances in time (Study 1), space (Study 2), social distance (Study 3), and hypotheticality (Study 4). Local processing had the opposite effect. Consistent with CLT, all studies show that the effect of global-versus-local processing did emerge when participants estimated egocentric distances, which are distances from the experienced self in the here and now, but did not emerge with temporal distances not from now (Study 1), spatial distances not from here (Study 2), social distances not from the self (Study 3), or hypothetical events that did not involve altering an experienced reality (Study 4).

Fast Computing for Distance Covariance

OpenAIRE

Huo, Xiaoming; Szekely, Gabor J.

2014-01-01

Distance covariance and distance correlation have been widely adopted in measuring dependence of a pair of random variables or random vectors. If the computation of distance covariance and distance correlation is implemented directly accordingly to its definition then its computational complexity is O($n^2$) which is a disadvantage compared to other faster methods. In this paper we show that the computation of distance covariance and distance correlation of real valued random variables can be...

ORDERED WEIGHTED DISTANCE MEASURE

Institute of Scientific and Technical Information of China (English)

Zeshui XU; Jian CHEN

2008-01-01

The aim of this paper is to develop an ordered weighted distance (OWD) measure, which is thegeneralization of some widely used distance measures, including the normalized Hamming distance, the normalized Euclidean distance, the normalized geometric distance, the max distance, the median distance and the min distance, etc. Moreover, the ordered weighted averaging operator, the generalized ordered weighted aggregation operator, the ordered weighted geometric operator, the averaging operator, the geometric mean operator, the ordered weighted square root operator, the square root operator, the max operator, the median operator and the min operator axe also the special cases of the OWD measure. Some methods depending on the input arguments are given to determine the weights associated with the OWD measure. The prominent characteristic of the OWD measure is that it can relieve (or intensify) the influence of unduly large or unduly small deviations on the aggregation results by assigning them low (or high) weights. This desirable characteristic makes the OWD measure very suitable to be used in many actual fields, including group decision making, medical diagnosis, data mining, and pattern recognition, etc. Finally, based on the OWD measure, we develop a group decision making approach, and illustrate it with a numerical example.

Improvement of the chromatic dispersion tolerance in coherent optical OFDM systems using shifted DFT windows for ultra-long-haul optical transmission systems.

Science.gov (United States)

Sung, Minkyu; Kim, Hoon; Lee, Jaehoon; Jeong, Jichai

2014-09-22

In a high-capacity ultra-long-haul optical coherent orthogonal frequency-division multiplexing (CO-OFDM) system, the dispersion tolerance is determined by the length of cyclic extension (CE). In this paper, we propose a novel scheme to substantially improve the dispersion tolerance of CO-OFDM systems without increasing the CE length. Multiple time-shifted discrete Fourier transform (DFT) windows are exploited at the receiver, each demodulating only a part of the subcarriers. Effectively, the proposed scheme reduces the bandwidth of the OFDM signals under demodulation. Numerical simulations are performed to show the improved dispersion tolerance of the proposed scheme in comparison with the conventional CO-OFDM system. We show that the dispersion tolerance improves by a factor equal to the number of DFT windows. The tradeoff between the improved dispersion tolerance and increased receiver complexity is also presented.

NIOSH national survey of long-haul truck drivers: Injury and safety

Science.gov (United States)

Chen, Guang X.; Sieber, W. Karl; Lincoln, Jennifer E.; Birdsey, Jan; Hitchcock, Edward M.; Nakata, Akinori; Robinson, Cynthia F.; Collins, James W.; Sweeney, Marie H.

2015-01-01

Approximately 1,701,500 people were employed as heavy and tractor-trailer truck drivers in the United States in 2012. The majority of them were long-haul truck drivers (LHTDs). There are limited data on occupational injury and safety in LHTDs, which prompted a targeted national survey. The National Institute of Occupational Safety and Health conducted a nationally representative survey of 1265 LHTDs at 32 truck stops across the contiguous United States in 2010. Data were collected on truck crashes, near misses, moving violations, work-related injuries, work environment, safety climate, driver training, job satisfaction, and driving behaviors. Results suggested that an estimated 2.6% of LHTDs reported a truck crash in 2010, 35% reported at least one crash while working as an LHTD, 24% reported at least one near miss in the previous 7 days, 17% reported at least one moving violation ticket and 4.7% reported a non-crash injury involving days away from work in the previous 12 months. The majority (68%) of non-crash injuries among company drivers were not reported to employers. An estimate of 73% of LHTDs (16% often and 58% sometimes) perceived their delivery schedules unrealistically tight; 24% often continued driving despite fatigue, bad weather, or heavy traffic because they needed to deliver or pick up a load at a given time; 4.5% often drove 10 miles per hours or more over the speed limit; 6.0% never wore a seatbelt; 36% were often frustrated by other drivers on the road; 35% often had to wait for access to a loading dock; 37% reported being noncompliant with hours-of-service rules (10% often and 27% sometimes); 38% of LHTDs perceived their entry-level training inadequate; and 15% did not feel that safety of workers was a high priority with their management. This survey brings to light a number of important safety issues for further research and interventions, e.g., high prevalence of truck crashes, injury underreporting, unrealistically tight delivery schedules

Flight time, number of sectors and risk of low back pain among short and medium haul commercial female flight attendants in Indonesia

Directory of Open Access Journals (Sweden)

Irma Khrisnapandit

2016-07-01

with LBP among short and medium haul commercial female flight attendants in Indonesia. Methods: Cross-sectional study with purposive sampling among short and medium haul commercial female flight attendants who conduct medical examination on May 5-26th 2014 at Civil Aviation Medical Center. Demographic, job and LBP data collected using questionnaire and physical examination. Definition of LBP was historically pain that ever or still felt in lower back in the last month, non-neural, and no non-working related acute injury. Cox regression analysis used to identify risk factor associated LBP. Results: Among 333 female flight attendants who were conducting medical examination, 287 attendants willing to participate, and 240 meet inclusion criteria. There are 37.9% flight attendants experienced LBP. The dominant factors increasing LBP risk were flight time and number of sectors in the last 24 consecutive hours. Female flight attendant with 9 hours or more flight time compared with less have 82% higher LBP risk [adjusted relative risk (RRa = 1.82; p = 0.000]. Review from number of sectors in the last 24 consecutive hours, female flight attendant with 4 sectors or more compared with less have 53% higher LBP risk (RRa = 1.53; p = 0.034.   Conclusion: Nine hours or more flight time and 4 sectors or more in the last 24 consecutive hours have higher risk of LBP Key words: low back pain, female flight attendant, flight time, number of sectors, short and medium haul flight

Idling Reduction for Long-Haul Trucks: An Economic Comparison of On-Board and Wayside Technologies

Energy Technology Data Exchange (ETDEWEB)

Gaines, Linda [Argonne National Lab. (ANL), Argonne, IL (United States); Weikersheimer, Patricia [Argonne National Lab. (ANL), Argonne, IL (United States)

2016-09-01

Reducing the idling of long-haul heavy-duty trucks has long been recognized as a particularly low-hanging fruit of fuel efficiency and emissions reduction. The displacement of about 10 hours of diesel idling every day, for most days of the year, for as many as a million long-haul trucks has very clear benefits. This report considers the costs and return on investment (ROI) for idling reduction (IR) equipment for both truck owners and electrified parking space (EPS) equipment owners. For the truck owners, the key variables examined are idling hours to be displaced (generally 1,000 to 2,000 hours per year) and the price of fuel ($0 to $5/gal). The ideal IR option would provide complete services in varied climates in any location and offer the best ROI on trucks that log many idling hours. For trucks that have fewer idling hours, options with a fixed cost per hour (i.e., EPS) might be most attractive if they were available to all, or even most, truck drivers. EPS, however, is particularly cost effective for trucks on prescribed routes with a need for regular, extended stops at terminals. (EPS is also called truck stop electrification, or TSE.) The analysis shows that all IR options save money when fuel costs more than $2/gal. For trucks requiring bunk heat, a simple heater (plug-in or diesel) is almost always the most costeffective way to provide heat, even if the truck is equipped with an auxiliary power unit (APU) or is parked at a single-system EPS location. For trucks requiring bunk air-conditioning, the use of single-system EPS is most cost effective for those logging fewer idling hours. Even for trucks with higher idling hours, the cost of EPS may be about the same as that for on-board air-conditioning. Clearly, trucks’ locations and seasonal factors—and the availability of EPS— are significant in the choice of “best fit” IR equipment for truck owners. This report also considers costs and payback for owners of EPS infrastructure. An industry that 5

Sleep quality in long haul truck drivers: A study on Iranian national data.

Science.gov (United States)

Sadeghniiat-Haghighi, Khosro; Yazdi, Zohreh; Kazemifar, Amir-Mohammad

2016-08-01

Iran has a high rate of road traffic accidents. Poor quality of sleep brings about loss of attention, which is an important cause of road traffic accidents particularly in monotonous roads. The causes of poor quality of sleep in occupational drivers are multifactorial. The objective of the present study was to assess the prevalence of poor sleep quality among occupational drivers with rotating work schedules and analyze its different risk factors. 2200 professional long-haul truck drivers who had been referred to the Occupational Health Clinic for routine education course were invited. We obtained data from eight provinces from various parts of Iran during 2012-2013. Data were collected using a questionnaire including questions about demographic and job characteristics. Pittsburg Sleep Quality Index (PSQI) was used to assess drivers' sleep quality. Mean working (driving) time was (9.3±2.5) hours daily and (55.5 ± 18.29) hours weekly. About 23.5% of the drivers reported history of smoking, 14.5% had low job satisfaction and 60% had irregular work schedule. 16.4% of drivers had an accidents leading to injury during the past five years. The mean PSQI score was 4.2 ± 2.7; 54% had a PSQI>5 (poor quality of sleep). Multivariate logistic regression showed that smoking, job satisfaction, history of accidents, shift work and work hours per day were the most important risk factors for poor sleep quality. Results obtained from the current study showed a high prevalence of poor quality of sleep among professional drivers. It warrants more attention to this significant problem using some measures to improve working conditions in professional drivers, as well as health promotion interventions.

THE DISTANCE TO M51

Energy Technology Data Exchange (ETDEWEB)

McQuinn, Kristen B. W. [University of Texas at Austin, McDonald Observatory, 2515 Speedway, Stop C1400 Austin, TX 78712 (United States); Skillman, Evan D. [Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street, S.E., University of Minnesota, Minneapolis, MN 55455 (United States); Dolphin, Andrew E. [Raytheon Company, 1151 E. Hermans Road, Tucson, AZ 85756 (United States); Berg, Danielle [Center for Gravitation, Cosmology and Astrophysics, Department of Physics, University of Wisconsin Milwaukee, 1900 East Kenwood Boulevard, Milwaukee, WI 53211 (United States); Kennicutt, Robert, E-mail: kmcquinn@astro.as.utexas.edu [Institute for Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom)

2016-07-20

Great investments of observing time have been dedicated to the study of nearby spiral galaxies with diverse goals ranging from understanding the star formation process to characterizing their dark matter distributions. Accurate distances are fundamental to interpreting observations of these galaxies, yet many of the best studied nearby galaxies have distances based on methods with relatively large uncertainties. We have started a program to derive accurate distances to these galaxies. Here we measure the distance to M51—the Whirlpool galaxy—from newly obtained Hubble Space Telescope optical imaging using the tip of the red giant branch method. We measure the distance modulus to be 8.58 ± 0.10 Mpc (statistical), corresponding to a distance modulus of 29.67 ± 0.02 mag. Our distance is an improvement over previous results as we use a well-calibrated, stable distance indicator, precision photometry in a optimally selected field of view, and a Bayesian Maximum Likelihood technique that reduces measurement uncertainties.

Encyclopedia of distances

CERN Document Server

Deza, Michel Marie

2009-01-01

Distance metrics and distances have become an essential tool in many areas of pure and applied Mathematics. This title offers both independent introductions and definitions, while at the same time making cross-referencing easy through hyperlink-like boldfaced references to original definitions.

Satellite fixed communications service: A forecast of potential domestic demand through the year 2000. Volume 3: Appendices

Science.gov (United States)

Kratochvil, D.; Bowyer, J.; Bhushan, C.; Steinnagel, K.; Kaushal, D.; Al-Kinani, G.

1983-09-01

Voice applications, data applications, video applications, impacted baseline forecasts, market distribution model, net long haul forecasts, trunking earth station definition and costs, trunking space segment cost, trunking entrance/exit links, trunking network costs and crossover distances with terrestrial tariffs, net addressable forecasts, capacity requirements, improving spectrum utilization, satellite system market development, and the 30/20 net accessible market are considered.

LED-based high-speed visible light communications

Science.gov (United States)

Chi, Nan; Shi, Meng; Zhao, Yiheng; Wang, Fumin; Shi, Jianyang; Zhou, Yingjun; Lu, Xingyu; Qiao, Liang

2018-01-01

We are seeing a growing use of light emitting diodes (LEDs) in a range of applications including lighting, TV and backlight board screen, display etc. In comparison with the traditional incandescent and fluorescent light bulbs, LEDs offer long life-space, much higher energy efficiency, high performance cost ratio and above all very fast switching capability. LED based Visible Light Communications (VLC) is an emerging field of optical communications that focuses on the part of the electromagnetic spectrum that humans can see. Depending on the transmission distance, we can divide the whole optical network into two categories, long haul and short haul. Visible light communication can be a promising candidate for short haul applications. In this paper, we outline the configuration of VLC, its unique benefits, and describe the state of the art research contributions consisting of advanced modulation formats including adaptive bit loading OFDM, carrierless amplitude and phase (CAP), pulse amplitude modulation (PAM) and single carrier Nyquist, linear equalization and nonlinear distortion mitigation based on machine learning, quasi-balanced coding and phase-shifted Manchester coding. These enabling technologies can support VLC up to 10Gb/s class free space transmission.

Learner characteristics involved in distance learning

Energy Technology Data Exchange (ETDEWEB)

Cernicek, A.T.; Hahn, H.A.

1991-01-01

Distance learning represents a strategy for leveraging resources to solve educational and training needs. Although many distance learning programs have been developed, lessons learned regarding differences between distance learning and traditional education with respect to learner characteristics have not been well documented. Therefore, we conducted a survey of 20 distance learning professionals. The questionnaire was distributed to experts attending the second Distance Learning Conference sponsored by Los Alamos National Laboratory. This survey not only acquired demographic information from each of the respondents but also identified important distance learning student characteristics. Significant distance learner characteristics, which were revealed statistically and which influence the effectiveness of distance learning, include the following: reading level, student autonomy, and self-motivation. Distance learning cannot become a more useful and effective method of instruction without identifying and recognizing learner characteristics. It will be important to consider these characteristics when designing all distance learning courses. This paper will report specific survey findings and their implications for developing distance learning courses. 9 refs., 6 tabs.

Health survey of U.S. long-haul truck drivers: work environment, physical health, and healthcare access.

Science.gov (United States)

Apostolopoulos, Yorghos; Sönmez, Sevil; Shattell, Mona M; Gonzales, Clifford; Fehrenbacher, Caitlin

2013-01-01

While trucking in industrialized nations is linked with driver health afflictions, the role of trucking in U.S. truckers' health remains largely unknown. This paper sheds light on links between the trucking work environment and drivers' physical health. Using a cross-sectional design, 316 truckers were enrolled in the Healthy Trucker Survey. Questions included work history, physical and mental health, and healthcare access. PASW 18 was used to examine patterns among factors. 316 truckers participated. Respondents were mainly full-time, long-haul drivers with over 5 years of experience, and who spent over 17 days on the road per month. While almost 75% described their health as good, 83.4% were overweight/obese, 57.9% had sleeping disturbances, 56.3% fatigue, 42.3% musculoskeletal disorders, and about 40% cardiovascular disease concerns. About 33% had no health insurance, 70% had no regular healthcare visits, 24.4% could not afford insurance, and 42.1% took over-the-counter drugs when sick, while 20.1% waited to reach home for medical care. Exercise facilities were unavailable in over 70% of trucking worksites and 70% of drivers did not exercise regularly. The trucking occupation places drivers at high risk for poor health outcomes. Prospective studies are needed to delve into how continued exposure to trucking influences the progression of disease burden.

Distance Magic-Type and Distance Antimagic-Type Labelings of Graphs

Science.gov (United States)

Freyberg, Bryan J.

Generally speaking, a distance magic-type labeling of a graph G of order n is a bijection l from the vertex set of the graph to the first n natural numbers or to the elements of a group of order n, with the property that the weight of each vertex is the same. The weight of a vertex x is defined as the sum (or appropriate group operation) of all the labels of vertices adjacent to x. If instead we require that all weights differ, then we refer to the labeling as a distance antimagic-type labeling. This idea can be generalized for directed graphs; the weight will take into consideration the direction of the arcs. In this manuscript, we provide new results for d-handicap labeling, a distance antimagic-type labeling, and introduce a new distance magic-type labeling called orientable Gamma-distance magic labeling. A d-handicap distance antimagic labeling (or just d-handicap labeling for short) of a graph G = ( V,E) of order n is a bijection l from V to the set {1,2,...,n} with induced weight function [special characters omitted]. such that l(xi) = i and the sequence of weights w(x 1),w(x2),...,w (xn) forms an arithmetic sequence with constant difference d at least 1. If a graph G admits a d-handicap labeling, we say G is a d-handicap graph. A d-handicap incomplete tournament, H(n,k,d ) is an incomplete tournament of n teams ranked with the first n natural numbers such that each team plays exactly k games and the strength of schedule of the ith ranked team is d more than the i + 1st ranked team. That is, strength of schedule increases arithmetically with strength of team. Constructing an H(n,k,d) is equivalent to finding a d-handicap labeling of a k-regular graph of order n.. In Chapter 2 we provide general constructions for every d for large classes of both n and k, providing breadfth and depth to the catalog of known H(n,k,d)'s. In Chapters 3 - 6, we introduce a new type of labeling called orientable Gamma-distance magic labeling. Let Gamma be an abelian group of order

Distance-transitive graphs

NARCIS (Netherlands)

Cohen, A.M.; Beineke, L.W.; Wilson, R.J.; Cameron, P.J.

2004-01-01

In this chapter we investigate the classification of distance-transitive graphs: these are graphs whose automorphism groups are transitive on each of the sets of pairs of vertices at distance i, for i = 0, 1,.... We provide an introduction into the field. By use of the classification of finite

Genome response to ionizing radiation exposure in a sample of long haul pilots

International Nuclear Information System (INIS)

De Stefano, G.F.; Fuciarelli, M.; Piacentini, S.; Romano, E.

2008-01-01

Full text: In 1990 ICPR accepted definitively that on average flying-crew personnel and pilots are exposed per year, for professional reasons, to ionizing radiation doses 5 to 10 times over that of people at ground level. Although these values are below the level stated by the ICPR as upper risk limit (20 mSv/y), because a number of epidemiological studies evidenced an increase of some specific tumors (among them: melanomas, breast cancer and leukemia) among pilots of different national companies, suspect arises on that these pathologies were a consequence of the over-amount of radiation absorbed for professional reasons. In order to give an answer to this question several studies have been developed in the last two decades, using the analysis of the frequency distribution of the chromosomal aberrations (mainly: dicentric and ring chromosomes and chromatic aberrations) as the most sensitive method to detect the long tern radio-biological damage (bio-dosimetric method). As the result reported in the previous literature are contradictory and thus largely questionable, a new study was performed taking into account some limits of the previous researches and treating to overcome the consequent criticisms. This paper is devoted to report the results obtained in such a study and refers on the cytogenetic and molecular analyses performed in our laboratories on a sample of 32 pilots employed in the national civil airline on long haul routes from at least 7 years. For comparison, a sample of 29 healthy males' donors of comparable age has been taken into account. New evidences on the increase of chromosomal translocations are presented and widely discussed. Furthermore, results obtained in an unusual attempt to study the association between the frequency and the 'category' of the chromosomal aberrations and the presence or absence of specific polymorphisms of genes encoding for some detoxifying enzymes (GSTs family) are also presented and discussed. (author)

Making Distance Visible: Assembling Nearness in an Online Distance Learning Programme

Science.gov (United States)

Ross, Jen; Gallagher, Michael Sean; Macleod, Hamish

2013-01-01

Online distance learners are in a particularly complex relationship with the educational institutions they belong to (Bayne, Gallagher, & Lamb, 2012). For part-time distance students, arrivals and departures can be multiple and invisible as students take courses, take breaks, move into independent study phases of a programme, find work or…

Steiner Distance in Graphs--A Survey

OpenAIRE

Mao, Yaping

2017-01-01

For a connected graph $G$ of order at least $2$ and $S\\subseteq V(G)$, the \\emph{Steiner distance} $d_G(S)$ among the vertices of $S$ is the minimum size among all connected subgraphs whose vertex sets contain $S$. In this paper, we summarize the known results on the Steiner distance parameters, including Steiner distance, Steiner diameter, Steiner center, Steiner median, Steiner interval, Steiner distance hereditary graph, Steiner distance stable graph, average Steiner distance, and Steiner ...

Theoretical Principles of Distance Education.

Science.gov (United States)

Keegan, Desmond, Ed.

This book contains the following papers examining the didactic, academic, analytic, philosophical, and technological underpinnings of distance education: "Introduction"; "Quality and Access in Distance Education: Theoretical Considerations" (D. Randy Garrison); "Theory of Transactional Distance" (Michael G. Moore);…

THE DISTANCE TO M104

Energy Technology Data Exchange (ETDEWEB)

McQuinn, Kristen B. W. [University of Texas at Austin, McDonald Observatory, 2515 Speedway, Stop C1400 Austin, TX 78712 (United States); Skillman, Evan D. [Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street, SE, University of Minnesota, Minneapolis, MN 55455 (United States); Dolphin, Andrew E. [Raytheon Company, 1151 E. Hermans Road, Tucson, AZ 85756 (United States); Berg, Danielle [Center for Gravitation, Cosmology and Astrophysics, Department of Physics, University of Wisconsin Milwaukee, 1900 East Kenwood Boulevard, Milwaukee, WI 53211 (United States); Kennicutt, Robert, E-mail: kmcquinn@astro.as.utexas.edu [Institute for Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom)

2016-11-01

M104 (NGC 4594; the Sombrero galaxy) is a nearby, well-studied elliptical galaxy included in scores of surveys focused on understanding the details of galaxy evolution. Despite the importance of observations of M104, a consensus distance has not yet been established. Here, we use newly obtained Hubble Space Telescope optical imaging to measure the distance to M104 based on the tip of the red giant branch (TRGB) method. Our measurement yields the distance to M104 to be 9.55 ± 0.13 ± 0.31 Mpc equivalent to a distance modulus of 29.90 ± 0.03 ± 0.07 mag. Our distance is an improvement over previous results as we use a well-calibrated, stable distance indicator, precision photometry in a optimally selected field of view, and a Bayesian maximum likelihood technique that reduces measurement uncertainties. The most discrepant previous results are due to Tully–Fisher method distances, which are likely inappropriate for M104 given its peculiar morphology and structure. Our results are part of a larger program to measure accurate distances to a sample of well-known spiral galaxies (including M51, M74, and M63) using the TRGB method.

The Distance to M51

Science.gov (United States)

McQuinn, Kristen. B. W.; Skillman, Evan D.; Dolphin, Andrew E.; Berg, Danielle; Kennicutt, Robert

2016-07-01

Great investments of observing time have been dedicated to the study of nearby spiral galaxies with diverse goals ranging from understanding the star formation process to characterizing their dark matter distributions. Accurate distances are fundamental to interpreting observations of these galaxies, yet many of the best studied nearby galaxies have distances based on methods with relatively large uncertainties. We have started a program to derive accurate distances to these galaxies. Here we measure the distance to M51—the Whirlpool galaxy—from newly obtained Hubble Space Telescope optical imaging using the tip of the red giant branch method. We measure the distance modulus to be 8.58 ± 0.10 Mpc (statistical), corresponding to a distance modulus of 29.67 ± 0.02 mag. Our distance is an improvement over previous results as we use a well-calibrated, stable distance indicator, precision photometry in a optimally selected field of view, and a Bayesian Maximum Likelihood technique that reduces measurement uncertainties. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

Are contemporary tourists consuming distance?

DEFF Research Database (Denmark)

Larsen, Gunvor Riber

2012. Background The background for this research, which explores how tourists represent distance and whether or not distance can be said to be consumed by contemporary tourists, is the increasing leisure mobility of people. Travelling for the purpose of visiting friends and relatives is increasing...... of understanding mobility at a conceptual level, and distance matters to people's manifest mobility: how they travel and how far they travel are central elements of their movements. Therefore leisure mobility (indeed all mobility) is the activity of relating across distance, either through actual corporeal...... metric representation. These representations are the focus for this research. Research Aim and Questions The aim of this research is thus to explore how distance is being represented within the context of leisure mobility. Further the aim is to explore how or whether distance is being consumed...

Terminology report respect distance. The Use of the term respect distance in Posiva and SKB

International Nuclear Information System (INIS)

Lampinen, H.

2007-09-01

The term respect distance is used in some key publications of the Finnish Nuclear Waste Management Company, Posiva, and the Swedish Nuclear Waste Management Company, SKB (Svensk Kaernbrenslehantering). Posiva and SKB researchers use the same terms in their reports, and it is acknowledged that the terms used by both companies are not used in the same way, though the differences are often subtle. This report is a literature study of the term 'respect distance' and the terms immediately associated to it. Vital terms related to the respect distance and issues concerning the use of scale concepts in Posiva and SKB are gathered in the end of report. Posiva's respect distances consider the seismic, hydrological and mechanical properties of the deterministic deformation zones as important issues that constitute a risk for longterm safety. These requirements for respect distances are an interpretation of STUK's YVL 8.4 Guide. At present, Posiva's criteria regarding respect distances follow the instructions given in the Host Rock Classification system (HRC), whereas the size of a deformation zone to which respect distances are applied vary from the regional to local major and minor. This and other criteria that are given for respect distances may, however, change in the near future as Posiva's Rock Suitability Criteria (RSC) programme proceeds. SKB's considerations of respect distances acknowledge that the hydraulic and mechanical aspects of a deformation zone have an effect on the respect distance. However, the seismic risk is considered to overshadow the other effects on a regional scale. The respect distance defined for a deformation zone is coupled with the size of a fracture where secondary slip could occur. In the safety assessment it is assumed that this fracture cuts a deposition hole location. In SKB the respect distance is determined for regional and local major deformation zones. The trace length of such a zone is defined as being ≥ 3 km. For deformation zones

New Maximal Two-distance Sets

DEFF Research Database (Denmark)

Lisonek, Petr

1996-01-01

A two-distance set in E^d is a point set X inthe d-dimensional Euclidean spacesuch that the distances between distinct points in Xassume only two different non-zero values. Based on results from classical distance geometry, we developan algorithm to classify, for a given dimension, all maximal...... (largest possible)two-distance sets in E^d.Using this algorithm we have completed the full classificationfor all dimensions less than or equal to 7, andwe have found one set in E^8 whosemaximality follows from Blokhuis' upper bound on sizes of s-distance sets.While in the dimensions less than or equal to 6...

Distance learning

Directory of Open Access Journals (Sweden)

Katarina Pucelj

2006-12-01

Full Text Available I would like to underline the role and importance of knowledge, which is acquired by individuals as a result of a learning process and experience. I have established that a form of learning, such as distance learning definitely contributes to a higher learning quality and leads to innovative, dynamic and knowledgebased society. Knowledge and skills enable individuals to cope with and manage changes, solve problems and also create new knowledge. Traditional learning practices face new circumstances, new and modern technologies appear, which enable quick and quality-oriented knowledge implementation. The centre of learning process at distance learning is to increase the quality of life of citizens, their competitiveness on the workforce market and ensure higher economic growth. Intellectual capital is the one, which represents the biggest capital of each society and knowledge is the key factor for succes of everybody, who are fully aware of this. Flexibility, openness and willingness of people to follow new IT solutions form suitable environment for developing and deciding to take up distance learning.

Analysis of major trends in U.S. commercial trucking, 1977-2002.

Energy Technology Data Exchange (ETDEWEB)

Bertram, K. M.; Santini, D .J.; Vyas, A. D.

2009-06-10

This report focuses on various major long-range (1977-2002) and intermediate-range (1982-2002) U.S. commercial trucking trends. The primary sources of data for this period were the U.S. Bureau of the Census Vehicle Inventory and Use Survey and Truck Inventory and Use Survey. In addition, selected 1977-2002 data from the U.S. Department of Energy/Energy Information Administration and from the U.S. Department of Transportation/Federal Highway Administration's Highway Statistics were used. The report analyzes (1) overall gasoline and diesel fuel consumption patterns by passenger vehicles and trucks and (2) the population changes and fuels used by all commercial truck classes by selected truck type (single unit or combination), during specified time periods, with cargo-hauling commercial trucks given special emphasis. It also assesses trends in selected vehicle miles traveled, gallons per vehicle miles traveled, and gallons per cargo ton-mile traveled, as well as the effect of cargo tons per truck on fuel consumption. In addition, the report examines long-range trends for related factors (e.g., long-haul mileages driven by heavy trucks) and their impacts on reducing fuel consumption per cargo-ton-mile and the relative shares of total commercial fuel use among truck classes. It identifies the effects of these trends on U.S. petroleum consumption. The report also discusses basic engineering design and performance, national legislation on interstate highway construction, national demographic trends (e.g., suburbanization), and changes in U.S. corporate operations requirements, and it highlights their impacts on both the long-distance hauling and shorter-distance urban and suburban delivery markets of the commercial trucking industry.

Fast Exact Euclidean Distance (FEED): A new class of adaptable distance transforms

NARCIS (Netherlands)

Schouten, Theo E.; van den Broek, Egon

2014-01-01

A new unique class of foldable distance transforms of digital images (DT) is introduced, baptized: Fast Exact Euclidean Distance (FEED) transforms. FEED class algorithms calculate the DT starting directly from the definition or rather its inverse. The principle of FEED class algorithms is

Fast Exact Euclidean Distance (FEED) : A new class of adaptable distance transforms

NARCIS (Netherlands)

Schouten, Theo E.; van den Broek, Egon L.

2014-01-01

A new unique class of foldable distance transforms of digital images (DT) is introduced, baptized: Fast Exact Euclidean Distance (FEED) transforms. FEED class algorithms calculate the DT startingdirectly from the definition or rather its inverse. The principle of FEED class algorithms is introduced,

Distance covariance for stochastic processes

DEFF Research Database (Denmark)

Matsui, Muneya; Mikosch, Thomas Valentin; Samorodnitsky, Gennady

2017-01-01

The distance covariance of two random vectors is a measure of their dependence. The empirical distance covariance and correlation can be used as statistical tools for testing whether two random vectors are independent. We propose an analog of the distance covariance for two stochastic processes...

Managing Time, Workload and Costs in Distance Education: Findings from a Literature Review of "Distances et Médiations des Savoirs" (Formerly "Distances et Savoirs")

Science.gov (United States)

Moeglin, Pierre; Vidal, Martine

2015-01-01

The purpose of this review, spanning over 12 years of publication of "Distances et Médiations des Savoirs" ("DMS"), formerly "Distance et Savoirs" ("DMS") (2003-2014), is guided by the question why and how French-speaking researchers addressed the issues of time, workload and costs in distance learning, and…

Critical Points in Distance Learning System

Directory of Open Access Journals (Sweden)

Airina Savickaitė

2013-08-01

Full Text Available Purpose – This article presents the results of distance learning system analysis, i.e. the critical elements of the distance learning system. The critical points of distance learning are a part of distance education online environment interactivity/community process model. The most important is the fact that the critical point is associated with distance learning participants. Design/methodology/approach – Comparative review of articles and analysis of distance learning module. Findings – A modern man is a lifelong learner and distance learning is a way to be a modern person. The focus on a learner and feedback is the most important thing of learning distance system. Also, attention should be paid to the lecture-appropriate knowledge and ability to convey information. Distance system adaptation is the way to improve the learner’s learning outcomes. Research limitations/implications – Different learning disciplines and learning methods may have different critical points. Practical implications – The information of analysis could be important for both lecturers and students, who studies distance education systems. There are familiar critical points which may deteriorate the quality of learning. Originality/value – The study sought to develop remote systems for applications in order to improve the quality of knowledge. Keywords: distance learning, process model, critical points. Research type: review of literature and general overview.

Connecting long distance: semantic distance in analogical reasoning modulates frontopolar cortex activity.

Science.gov (United States)

Green, Adam E; Kraemer, David J M; Fugelsang, Jonathan A; Gray, Jeremy R; Dunbar, Kevin N

2010-01-01

Solving problems often requires seeing new connections between concepts or events that seemed unrelated at first. Innovative solutions of this kind depend on analogical reasoning, a relational reasoning process that involves mapping similarities between concepts. Brain-based evidence has implicated the frontal pole of the brain as important for analogical mapping. Separately, cognitive research has identified semantic distance as a key characteristic of the kind of analogical mapping that can support innovation (i.e., identifying similarities across greater semantic distance reveals connections that support more innovative solutions and models). However, the neural substrates of semantically distant analogical mapping are not well understood. Here, we used functional magnetic resonance imaging (fMRI) to measure brain activity during an analogical reasoning task, in which we parametrically varied the semantic distance between the items in the analogies. Semantic distance was derived quantitatively from latent semantic analysis. Across 23 participants, activity in an a priori region of interest (ROI) in left frontopolar cortex covaried parametrically with increasing semantic distance, even after removing effects of task difficulty. This ROI was centered on a functional peak that we previously associated with analogical mapping. To our knowledge, these data represent a first empirical characterization of how the brain mediates semantically distant analogical mapping.

Climate change and the long-term viability of the World's busiest heavy haul ice road

Science.gov (United States)

Mullan, Donal; Swindles, Graeme; Patterson, Tim; Galloway, Jennifer; Macumber, Andrew; Falck, Hendrik; Crossley, Laura; Chen, Jie; Pisaric, Michael

2017-08-01

Climate models project that the northern high latitudes will warm at a rate in excess of the global mean. This will pose severe problems for Arctic and sub-Arctic infrastructure dependent on maintaining low temperatures for structural integrity. This is the case for the economically important Tibbitt to Contwoyto Winter Road (TCWR)—the world's busiest heavy haul ice road, spanning 400 km across mostly frozen lakes within the Northwest Territories of Canada. In this study, future climate scenarios are developed for the region using statistical downscaling methods. In addition, changes in lake ice thickness are projected based on historical relationships between measured ice thickness and air temperatures. These projections are used to infer the theoretical operational dates of the TCWR based on weight limits for trucks on the ice. Results across three climate models driven by four RCPs reveal a considerable warming trend over the coming decades. Projected changes in ice thickness reveal a trend towards thinner lake ice and a reduced time window when lake ice is at sufficient thickness to support trucks on the ice road, driven by increasing future temperatures. Given the uncertainties inherent in climate modelling and the resultant projections, caution should be exercised in interpreting the magnitude of these scenarios. More certain is the direction of change, with a clear trend towards winter warming that will reduce the operation time window of the TCWR. This illustrates the need for planners and policymakers to consider future changes in climate when planning annual haulage along the TCWR.

Equivalence of massive propagator distance and mathematical distance on graphs

International Nuclear Information System (INIS)

Filk, T.

1992-01-01

It is shown in this paper that the assignment of distance according to the massive propagator method and according to the mathematical definition (length of minimal path) on arbitrary graphs with a bound on the degree leads to equivalent large scale properties of the graph. Especially, the internal scaling dimension is the same for both definitions. This result holds for any fixed, non-vanishing mass, so that a really inequivalent definition of distance requires the limit m → 0

Language distance and tree reconstruction

International Nuclear Information System (INIS)

Petroni, Filippo; Serva, Maurizio

2008-01-01

Languages evolve over time according to a process in which reproduction, mutation and extinction are all possible. This is very similar to haploid evolution for asexual organisms and for the mitochondrial DNA of complex ones. Exploiting this similarity, it is possible, in principle, to verify hypotheses concerning the relationship among languages and to reconstruct their family tree. The key point is the definition of the distances among pairs of languages in analogy with the genetic distances among pairs of organisms. Distances can be evaluated by comparing grammar and/or vocabulary, but while it is difficult, if not impossible, to quantify grammar distance, it is possible to measure a distance from vocabulary differences. The method used by glottochronology computes distances from the percentage of shared 'cognates', which are words with a common historical origin. The weak point of this method is that subjective judgment plays a significant role. Here we define the distance of two languages by considering a renormalized edit distance among words with the same meaning and averaging over the two hundred words contained in a Swadesh list. In our approach the vocabulary of a language is the analogue of DNA for organisms. The advantage is that we avoid subjectivity and, furthermore, reproducibility of results is guaranteed. We apply our method to the Indo-European and the Austronesian groups, considering, in both cases, fifty different languages. The two trees obtained are, in many respects, similar to those found by glottochronologists, with some important differences as regards the positions of a few languages. In order to support these different results we separately analyze the structure of the distances of these languages with respect to all the others

Language distance and tree reconstruction

Science.gov (United States)

Petroni, Filippo; Serva, Maurizio

2008-08-01

Languages evolve over time according to a process in which reproduction, mutation and extinction are all possible. This is very similar to haploid evolution for asexual organisms and for the mitochondrial DNA of complex ones. Exploiting this similarity, it is possible, in principle, to verify hypotheses concerning the relationship among languages and to reconstruct their family tree. The key point is the definition of the distances among pairs of languages in analogy with the genetic distances among pairs of organisms. Distances can be evaluated by comparing grammar and/or vocabulary, but while it is difficult, if not impossible, to quantify grammar distance, it is possible to measure a distance from vocabulary differences. The method used by glottochronology computes distances from the percentage of shared 'cognates', which are words with a common historical origin. The weak point of this method is that subjective judgment plays a significant role. Here we define the distance of two languages by considering a renormalized edit distance among words with the same meaning and averaging over the two hundred words contained in a Swadesh list. In our approach the vocabulary of a language is the analogue of DNA for organisms. The advantage is that we avoid subjectivity and, furthermore, reproducibility of results is guaranteed. We apply our method to the Indo-European and the Austronesian groups, considering, in both cases, fifty different languages. The two trees obtained are, in many respects, similar to those found by glottochronologists, with some important differences as regards the positions of a few languages. In order to support these different results we separately analyze the structure of the distances of these languages with respect to all the others.

Interactive Distance Learning in Connecticut.

Science.gov (United States)

Pietras, Jesse John; Murphy, Robert J.

This paper provides an overview of distance learning activities in Connecticut and addresses the feasibility of such activities. Distance education programs have evolved from the one dimensional electronic mail systems to the use of sophisticated digital fiber networks. The Middlesex Distance Learning Consortium has developed a long-range plan to…

Compensation des effets nonlinéaires pour les transmissions WDM longue distance à 400Gbps et au-delà

OpenAIRE

Amari , Abdelkerim

2016-01-01

Optical communication systems have evolved since their deployment to meet the growing demand for high-speed communications. Over the past decades, the global demand for communication capacity has increased exponentially and the most of the growth has occurred in the last few years when data started dominating network traffic. In order to meet the increase of traffic demands fueled by the growth of internet services, an increase of access network capacity and consequently metro and long-haul n...

Effects of long-haul transmeridian travel on player preparedness: Case study of a national team at the 2014 FIFA World Cup.

Science.gov (United States)

Fowler, Peter M; McCall, Alan; Jones, Mark; Duffield, Rob

2017-04-01

Describe the effects of eastward long-haul transmeridian air travel on subjective jet-lag, sleep and wellness in professional football (soccer) players prior to the 2014 FIFA World Cup in Brazil. Single cohort involving twenty-two male professional football players representing a national football team. Data was collected from players prior to and following international travel from Sydney, Australia to Vitoria, Brazil. In total there were three flights, 19-h and 14,695km of travel east across 11 time-zones. Training load and wellness measures were obtained in the week prior to and following travel, whilst sleep and jet-lag measures were collected on the day prior to travel (Pre), the day of arrival and for five days following travel (Post 1-5). Compared to Pre, perceived jet-lag was significantly increased on Post 1 to 4, with significantly greater levels on Post 1 compared to Post 5 (pplayer wellness. Consequently, player preparedness for subsequent training and competition may be impeded, though physical performance data is lacking. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Motivation in Distance Leaming

Directory of Open Access Journals (Sweden)

Daniela Brečko

1996-12-01

Full Text Available It is estimated that motivation is one of the most important psychological functions making it possible for people to leam even in conditions that do not meet their needs. In distance learning, a form of autonomous learning, motivation is of outmost importance. When adopting this method in learning an individual has to stimulate himself and take learning decisions on his or her own. These specific characteristics of distance learning should be taken into account. This all different factors maintaining the motivation of partici­pants in distance learning are to be included. Moreover, motivation in distance learning can be stimulated with specific learning materials, clear instructions and guide-lines, an efficient feed back, personal contact between tutors and parti­cipants, stimulating learning letters, telephone calls, encouraging letters and through maintaining a positive relationship between tutor and participant.

Machine learning enhanced optical distance sensor

Science.gov (United States)

Amin, M. Junaid; Riza, N. A.

2018-01-01

Presented for the first time is a machine learning enhanced optical distance sensor. The distance sensor is based on our previously demonstrated distance measurement technique that uses an Electronically Controlled Variable Focus Lens (ECVFL) with a laser source to illuminate a target plane with a controlled optical beam spot. This spot with varying spot sizes is viewed by an off-axis camera and the spot size data is processed to compute the distance. In particular, proposed and demonstrated in this paper is the use of a regularized polynomial regression based supervised machine learning algorithm to enhance the accuracy of the operational sensor. The algorithm uses the acquired features and corresponding labels that are the actual target distance values to train a machine learning model. The optimized training model is trained over a 1000 mm (or 1 m) experimental target distance range. Using the machine learning algorithm produces a training set and testing set distance measurement errors of learning. Applications for the proposed sensor include industrial scenario distance sensing where target material specific training models can be generated to realize low <1% measurement error distance measurements.

Long-distance calls in Neotropical primates

Directory of Open Access Journals (Sweden)

Oliveira Dilmar A.G.

2004-01-01

Full Text Available Long-distance calls are widespread among primates. Several studies concentrate on such calls in just one or in few species, while few studies have treated more general trends within the order. The common features that usually characterize these vocalizations are related to long-distance propagation of sounds. The proposed functions of primate long-distance calls can be divided into extragroup and intragroup ones. Extragroup functions relate to mate defense, mate attraction or resource defense, while intragroup functions involve group coordination or alarm. Among Neotropical primates, several species perform long-distance calls that seem more related to intragroup coordination, markedly in atelines. Callitrichids present long-distance calls that are employed both in intragroup coordination and intergroup contests or spacing. Examples of extragroup directed long-distance calls are the duets of titi monkeys and the roars and barks of howler monkeys. Considerable complexity and gradation exist in the long-distance call repertoires of some Neotropical primates, and female long-distance calls are probably more important in non-duetting species than usually thought. Future research must focus on larger trends in the evolution of primate long-distance calls, including the phylogeny of calling repertoires and the relationships between form and function in these signals.

Robustness of Distance-to-Default

DEFF Research Database (Denmark)

Jessen, Cathrine; Lando, David

2013-01-01

Distance-to-default is a remarkably robust measure for ranking firms according to their risk of default. The ranking seems to work despite the fact that the Merton model from which the measure is derived produces default probabilities that are far too small when applied to real data. We use...... simulations to investigate the robustness of the distance-to-default measure to different model specifications. Overall we find distance-to-default to be robust to a number of deviations from the simple Merton model that involve different asset value dynamics and different default triggering mechanisms....... A notable exception is a model with stochastic volatility of assets. In this case both the ranking of firms and the estimated default probabilities using distance-to-default perform significantly worse. We therefore propose a volatility adjustment of the distance-to-default measure, that significantly...

Distance Education in Technological Age

Directory of Open Access Journals (Sweden)

R .C. SHARMA

2005-04-01

Full Text Available Distance Education in Technological AgeRomesh Verma (Editor, New Delhi: Anmol Publications, 2005, ISBN 81-261-2210-2, pp. 419 Reviewed by R C SHARMARegional DirectorIndira Gandhi National Open University-INDIA The advancements in information and communication technologies have brought significant changes in the way the open and distance learning are provided to the learners. The impact of such changes is quite visible in both developed and developing countries. Switching over to online mode, joining hands with private initiatives and making a presence in foreign waters, are some of the hallmarks of the open and distance education (ODE institutions in developing countries. The compilation of twenty six essays on themes as applicable to ODE has resulted in the book, “Distance Education in Technological Age”. These essays follow a progressive style of narration, starting from describing conceptual framework of distance education, how the distance education was emerged on the global scene and in India, and then goes on to discuss emergence of online distance education and research aspects in ODE. The initial four chapters provide a detailed account of historical development and growth of distance education in India and State Open University and National Open University Model in India . Student support services are pivot to any distance education and much of its success depends on how well the support services are provided. These are discussed from national and international perspective. The issues of collaborative learning, learning on demand, life long learning, learning-unlearning and re-learning model and strategic alliances have also given due space by the authors. An assortment of technologies like communication technology, domestic technology, information technology, mass media and entertainment technology, media technology and educational technology give an idea of how these technologies are being adopted in the open universities. The study

Improved Iris Recognition through Fusion of Hamming Distance and Fragile Bit Distance.

Science.gov (United States)

Hollingsworth, Karen P; Bowyer, Kevin W; Flynn, Patrick J

2011-12-01

The most common iris biometric algorithm represents the texture of an iris using a binary iris code. Not all bits in an iris code are equally consistent. A bit is deemed fragile if its value changes across iris codes created from different images of the same iris. Previous research has shown that iris recognition performance can be improved by masking these fragile bits. Rather than ignoring fragile bits completely, we consider what beneficial information can be obtained from the fragile bits. We find that the locations of fragile bits tend to be consistent across different iris codes of the same eye. We present a metric, called the fragile bit distance, which quantitatively measures the coincidence of the fragile bit patterns in two iris codes. We find that score fusion of fragile bit distance and Hamming distance works better for recognition than Hamming distance alone. To our knowledge, this is the first and only work to use the coincidence of fragile bit locations to improve the accuracy of matches.

Partial distance correlation with methods for dissimilarities

OpenAIRE

Székely, Gábor J.; Rizzo, Maria L.

2014-01-01

Distance covariance and distance correlation are scalar coefficients that characterize independence of random vectors in arbitrary dimension. Properties, extensions, and applications of distance correlation have been discussed in the recent literature, but the problem of defining the partial distance correlation has remained an open question of considerable interest. The problem of partial distance correlation is more complex than partial correlation partly because the squared distance covari...

Making Distance Visible: Assembling Nearness in an Online Distance Learning Programme

Directory of Open Access Journals (Sweden)

Jen Ross

2013-09-01

Full Text Available Online distance learners are in a particularly complex relationship with the educational institutions they belong to (Bayne, Gallagher, & Lamb, 2012. For part-time distance students, arrivals and departures can be multiple and invisible as students take courses, take breaks, move into independent study phases of a programme, find work or family commitments overtaking their study time, experience personal upheaval or loss, and find alignments between their professional and academic work. These comings and goings indicate a fluid and temporary assemblage of engagement, not a permanent or stable state of either “presence” or “distance”. This paper draws from interview data from the “New Geographies of Learning” project, a research project exploring the notions of space and institution for the MSc in Digital Education at the University of Edinburgh, and from literature on distance learning and online community. The concept of nearness emerged from the data analyzing the comings and goings of students on a fully online programme. It proposes that “nearness” to a distance programme is a temporary assemblage of people, circumstances, and technologies. This state is difficult to establish and impossible to sustain in an uninterrupted way over the long period of time that many are engaged in part-time study. Interruptions and subsequent returns should therefore be seen as normal in the practice of studying as an online distance learner, and teachers and institutions should work to help students develop resilience in negotiating various states of nearness. Four strategies for increasing this resilience are proposed: recognising nearness as effortful; identifying affinities; valuing perspective shifts; and designing openings.

Distance labeling schemes for trees

DEFF Research Database (Denmark)

Alstrup, Stephen; Gørtz, Inge Li; Bistrup Halvorsen, Esben

2016-01-01

We consider distance labeling schemes for trees: given a tree with n nodes, label the nodes with binary strings such that, given the labels of any two nodes, one can determine, by looking only at the labels, the distance in the tree between the two nodes. A lower bound by Gavoille et al. [Gavoille...... variants such as, for example, small distances in trees [Alstrup et al., SODA, 2003]. We improve the known upper and lower bounds of exact distance labeling by showing that 1/4 log2(n) bits are needed and that 1/2 log2(n) bits are sufficient. We also give (1 + ε)-stretch labeling schemes using Theta...

Tracking frequency laser distance gauge

International Nuclear Information System (INIS)

Phillips, J.D.; Reasenberg, R.D.

2005-01-01

Advanced astronomical missions with greatly enhanced resolution and physics missions of unprecedented accuracy will require laser distance gauges of substantially improved performance. We describe a laser gauge, based on Pound-Drever-Hall locking, in which the optical frequency is adjusted to maintain an interferometer's null condition. This technique has been demonstrated with pm performance. Automatic fringe hopping allows it to track arbitrary distance changes. The instrument is intrinsically free of the nm-scale cyclic bias present in traditional (heterodyne) high-precision laser gauges. The output is a radio frequency, readily measured to sufficient accuracy. The laser gauge has operated in a resonant cavity, which improves precision, can suppress the effects of misalignments, and makes possible precise automatic alignment. The measurement of absolute distance requires little or no additional hardware, and has also been demonstrated. The proof-of-concept version, based on a stabilized HeNe laser and operating on a 0.5 m path, has achieved 10 pm precision with 0.1 s integration time, and 0.1 mm absolute distance accuracy. This version has also followed substantial distance changes as fast as 16 mm/s. We show that, if the precision in optical frequency is a fixed fraction of the linewidth, both incremental and absolute distance precision are independent of the distance measured. We discuss systematic error sources, and present plans for a new version of the gauge based on semiconductor lasers and fiber-coupled components

ADULT LEARNERS IN DISTANCE HIGHER EDUCATION

Directory of Open Access Journals (Sweden)

NORICA-FELICIA BUCUR

2012-05-01

Full Text Available This paper attempts at identifying the main features that characterize distance higher education and adult education, respectively, in order to be able to establish to what extent adult learners can fit in distance higher education programs. The historical background of distance learning education, the factors that influence adult learners, and distance learning’s key objectives, effects, issues, advantages, and disadvantages are to be briefly investigated in order to reach the purpose of this paper. Recent developments in Information Technology have led to a new approach to teaching and learning, especially as far as adult learning and distance learning are concerned. Thus, this study will also focus on the consequences of using technology for course design, delivery, and the perception of adult learners participating in distance learning.

Distance and Cable Length Measurement System

Science.gov (United States)

Hernández, Sergio Elias; Acosta, Leopoldo; Toledo, Jonay

2009-01-01

A simple, economic and successful design for distance and cable length detection is presented. The measurement system is based on the continuous repetition of a pulse that endlessly travels along the distance to be detected. There is a pulse repeater at both ends of the distance or cable to be measured. The endless repetition of the pulse generates a frequency that varies almost inversely with the distance to be measured. The resolution and distance or cable length range could be adjusted by varying the repetition time delay introduced at both ends and the measurement time. With this design a distance can be measured with centimeter resolution using electronic system with microsecond resolution, simplifying classical time of flight designs which require electronics with picosecond resolution. This design was also applied to position measurement. PMID:22303169

Distance Education in Entwicklungslandern.

Science.gov (United States)

German Foundation for International Development, Bonn (West Germany).

Seminar and conference reports and working papers on distance education of adults, which reflect the experiences of many countries, are presented. Contents include the draft report of the 1979 International Seminar on Distance Education held in Addis Ababa, Ethiopia, which was jointly sponsored by the United Nations Economic Commission for Africa…

Distance sampling methods and applications

CERN Document Server

Buckland, S T; Marques, T A; Oedekoven, C S

2015-01-01

In this book, the authors cover the basic methods and advances within distance sampling that are most valuable to practitioners and in ecology more broadly. This is the fourth book dedicated to distance sampling. In the decade since the last book published, there have been a number of new developments. The intervening years have also shown which advances are of most use. This self-contained book covers topics from the previous publications, while also including recent developments in method, software and application. Distance sampling refers to a suite of methods, including line and point transect sampling, in which animal density or abundance is estimated from a sample of distances to detected individuals. The book illustrates these methods through case studies; data sets and computer code are supplied to readers through the book’s accompanying website.  Some of the case studies use the software Distance, while others use R code. The book is in three parts.  The first part addresses basic methods, the ...

Anxiety and Resistance in Distance Learning

OpenAIRE

Nazime Tuncay; Huseyin Uzunboylu

2010-01-01

The purpose of this study was to investigate students' anxiety and resistance towards learning through distance education.Specifically, the study sought answers to the following questions: -What are the reasons of students not choosing distancelearning courses? -Which symptoms of anxiety, if any, do distance learner’s exhibit towards distance learning? Does genderhave any significant relationships with distance learners' perception of factors that affect their anxiety and resistance? A totalo...

Revised Distances to 21 Supernova Remnants

Science.gov (United States)

Ranasinghe, S.; Leahy, D. A.

2018-05-01

We carry out a comprehensive study of H I 21 cm line observations and 13CO line observations of 21 supernova remnants (SNRs). The aim of the study is to search for H I absorption features to obtain kinematic distances in a consistent manner. The 21 SNRs are in the region of sky covered by the Very Large Array Galactic Plane Survey (H I 21 cm observations) and Galactic Ring Survey (13CO line observations). We obtain revised distances for 10 SNRs based on new evidence in the H I and 13CO observations. We revise distances for the other 11 SNRs based on an updated rotation curve and new error analysis. The mean change in distance for the 21 SNRs is ≃25%, i.e., a change of 1.5 kpc compared to a mean distance for the sample of 6.4 kpc. This has a significant impact on interpretation of the physical state of these SNRs. For example, using a Sedov model, age and explosion energy scale as the square of distance, and inferred ISM density scales as distance.

A cognitively grounded measure of pronunciation distance.

Directory of Open Access Journals (Sweden)

Martijn Wieling

Full Text Available In this study we develop pronunciation distances based on naive discriminative learning (NDL. Measures of pronunciation distance are used in several subfields of linguistics, including psycholinguistics, dialectology and typology. In contrast to the commonly used Levenshtein algorithm, NDL is grounded in cognitive theory of competitive reinforcement learning and is able to generate asymmetrical pronunciation distances. In a first study, we validated the NDL-based pronunciation distances by comparing them to a large set of native-likeness ratings given by native American English speakers when presented with accented English speech. In a second study, the NDL-based pronunciation distances were validated on the basis of perceptual dialect distances of Norwegian speakers. Results indicated that the NDL-based pronunciation distances matched perceptual distances reasonably well with correlations ranging between 0.7 and 0.8. While the correlations were comparable to those obtained using the Levenshtein distance, the NDL-based approach is more flexible as it is also able to incorporate acoustic information other than sound segments.

Fast Exact Euclidean Distance (FEED) Transformation

NARCIS (Netherlands)

Schouten, Theo; Kittler, J.; van den Broek, Egon; Petrou, M.; Nixon, M.

2004-01-01

Fast Exact Euclidean Distance (FEED) transformation is introduced, starting from the inverse of the distance transformation. The prohibitive computational cost of a naive implementation of traditional Euclidean Distance Transformation, is tackled by three operations: restriction of both the number

Distance : between deixis and perspectivity

OpenAIRE

Meermann, Anastasia; Sonnenhauser, Barbara

2015-01-01

Discussing exemplary applications of the notion of distance in linguistic analysis, this paper shows that very different phenomena are described in terms of this concept. It is argued that in order to overcome the problems arising from this mixup, deixis, distance and perspectivity have to be distinguished and their interrelations need to be described. Thereby, distance emerges as part of a recursive process mediating between situation-bound deixis and discourse-level perspectivity. This is i...

The distances of the Galactic Novae

Science.gov (United States)

Ozdonmez, Aykut; Guver, Tolga; Cabrera-Lavers, Antonio; Ak, Tansel

2016-07-01

Using location of the RC stars on the CMDs obtained from the UKIDSS, VISTA and 2MASS photometry, we have derived the reddening-distance relations towards each Galactic nova for which at least one independent reddening measurement exists. We were able to determine the distances of 72 Galactic novae and set lower limits on the distances of 45 systems. The reddening curves of the systems are presented. These curves can be also used to estimate reddening or the distance of any source, whose location is close to the position of the nova in our sample. The distance measurement method in our study can be easily applicable to any source, especially for ones that concentrated along the Galactic plane.

ETUDE - European Trade Union Distance Education.

Science.gov (United States)

Creanor, Linda; Walker, Steve

2000-01-01

Describes transnational distance learning activities among European trade union educators carried out as part of the European Trade Union Distance Education (ETUDE) project, supported by the European Commission. Highlights include the context of international trade union distance education; tutor training course; tutors' experiences; and…

Space-efficient path-reporting approximate distance oracles

DEFF Research Database (Denmark)

Elkin, Michael; Neiman, Ofer; Wulff-Nilsen, Christian

2016-01-01

We consider approximate path-reporting distance oracles, distance labeling and labeled routing with extremely low space requirements, for general undirected graphs. For distance oracles, we show how to break the nlog⁡n space bound of Thorup and Zwick if approximate paths rather than distances need...

Successful coal winning with two shearers using chainless haulage

Energy Technology Data Exchange (ETDEWEB)

Fritz, W

1977-10-06

Coal winning in one production district at Rheinpreussen Colliery is described. Extracted seam thickness is 2.95 m, of which 1.15 m is dirt. Eickhoff double-ended ranging shearer loaders with Eicotrack chainless haulage have proved successful, even though this coal is difficult to cut because of the dirt bands. The introduction of twin-belt conveyor drives allowed the distances between centers in the long-haul belt systems to be increased, thereby improving safety.

What do long-distance caregivers do? : judgment of propositions and the epistemics of long-distance family relationships

OpenAIRE

中川, 敦; Atsushi, NAKAGAWA

2015-01-01

This study clarifies what long-distance caregivers do. To this end, I conducted a conversation analysis of video data of a care conference in which a long-distance caregiver participated. When a professional caregiver proposes a care plan to a long-distance caregiver, he/she substitutes technical terms with laymen terms for easy understanding, indicating his/her orientation that a long-distance caregiver is not a professional. However, if the caregiver laughs or averts his/her eyes during the...

Phylogenetic inference with weighted codon evolutionary distances.

Science.gov (United States)

Criscuolo, Alexis; Michel, Christian J

2009-04-01

We develop a new approach to estimate a matrix of pairwise evolutionary distances from a codon-based alignment based on a codon evolutionary model. The method first computes a standard distance matrix for each of the three codon positions. Then these three distance matrices are weighted according to an estimate of the global evolutionary rate of each codon position and averaged into a unique distance matrix. Using a large set of both real and simulated codon-based alignments of nucleotide sequences, we show that this approach leads to distance matrices that have a significantly better treelikeness compared to those obtained by standard nucleotide evolutionary distances. We also propose an alternative weighting to eliminate the part of the noise often associated with some codon positions, particularly the third position, which is known to induce a fast evolutionary rate. Simulation results show that fast distance-based tree reconstruction algorithms on distance matrices based on this codon position weighting can lead to phylogenetic trees that are at least as accurate as, if not better, than those inferred by maximum likelihood. Finally, a well-known multigene dataset composed of eight yeast species and 106 codon-based alignments is reanalyzed and shows that our codon evolutionary distances allow building a phylogenetic tree which is similar to those obtained by non-distance-based methods (e.g., maximum parsimony and maximum likelihood) and also significantly improved compared to standard nucleotide evolutionary distance estimates.

The effect of workload and other risk factors of metabolic syndrome among short-haul commercial pilots in Indonesia

Directory of Open Access Journals (Sweden)

Inne Yuliawati

2016-03-01

Full Text Available AbstrakLatar belakang: Sindroma metabolik (MS dapat menyebabkan kecacatan di antara pilot di Indonesia.Tujuan dari penelitian ini adalah untuk mengidentifikasi faktor-faktor risiko MS antara pilot komersialjarak pendek di Indonesia.Metode: Penelitian potong lintang dengan sampling purposif yang dilakukan di antara pilot komersial yangmelakukan uji medik di Balai Kesehatan Penerbangan Sipil, Jakarta tanggal 27 Juli-30 Agustus 2014. Sindromametabolik dinilai menurutkriterian National Cholesterol Education Program Adult Treatment Panel III. Faktorrisiko diperoleh dengan menggunakan kuesioner self-reporting anonim. Data laboratorium diperoleh daricatatan medis. Regresi Cox digunakan untuk mengidentifikasi faktor-faktor risiko yang dominan dari MS.Hasil: Selama pengumpulan data, 2135 pilot melakukan uji medik. Jumlah pilot Asia laki-laki memenuhi kriteriainklusi adalah 864 pilot. Prevalensi MS adalah 18,28%. Dibandingkan dengan kelompok 20-35 tahun, yangberusia berusia 56-65 tahun memiliki risiko 88% lebih tinggi untuk MS [risiko relatif sesuaian (RRa = 1,88;P = 0,019]. Jika ditinjau dari jumlah sektor dalam 24 jam terakhir, dibandingkan dengan 0-3 sektor, subyekyang memiliki 6-7 sektor mempunyai risiko 66% lebih tinggi untuk MS (RRa = 1,66; P = 0,033, sedangkanyang memiliki 8 atau lebih sektor dalam 24 jam memiliki 82% lebih berisiko untuk MS (RRa = 1,82; P = 0,072.Kesimpulan: Pilot berusia tahun-56-65, yang memiliki 6 atau lebih sektor dalam 24 jam terakhir, memilikirisiko lebih tinggi untuk sindroma metabolik antara jarak pendek pilot komersial di Indonesia. (HealthScience Journal of Indonesia 2015;6:81-6Kata kunci: Sindroma metabolik, jumlah sektor, pilot, Indonesia Abstract Background: Metabolic syndrome (MS could cause sudden incapacitation among pilots in Indonesia.The aim of this study was to identify risk factors of MS among short-haul commercial pilots in Indonesia.Methods: A cross-sectional study with purposive sampling was conducted

Distance Education at Silesian University of Technology

Directory of Open Access Journals (Sweden)

Piotr Klosowski

2008-12-01

Full Text Available This paper presents Distance Learning Platform used by Silesian University of Technology. Distance Learning Platform is based on modular object-oriented dynamic learning environment, represents LMS (Learning Management Systems technology, a software package designed to help educators create quality online courses. Currently on Distance Learning Platform at Silesian University of Technology are available over 520 online courses created for students of twelve University's faculties. Number of Distance Learning Platform users exceeds 12000. Distance Learning Platform works as typically asynchronous e-learning service, but in the future more synchronous e-learning services will be added. Distance Learning Platform has great potential to create a successful elearning experience by providing a plethora of excellent tools that can be used to enhance conventional classroom instruction, in hybrid courses, or any distance learning arrangements.

A Streaming Distance Transform Algorithm for Neighborhood-Sequence Distances

Directory of Open Access Journals (Sweden)

Nicolas Normand

2014-09-01

Full Text Available We describe an algorithm that computes a “translated” 2D Neighborhood-Sequence Distance Transform (DT using a look up table approach. It requires a single raster scan of the input image and produces one line of output for every line of input. The neighborhood sequence is specified either by providing one period of some integer periodic sequence or by providing the rate of appearance of neighborhoods. The full algorithm optionally derives the regular (centered DT from the “translated” DT, providing the result image on-the-fly, with a minimal delay, before the input image is fully processed. Its efficiency can benefit all applications that use neighborhood- sequence distances, particularly when pipelined processing architectures are involved, or when the size of objects in the source image is limited.

Predicting the effect of seine rope layout pattern and haul-in procedure on the effectiveness of demersal seine fishing: A Computer simulation-based approach.

Science.gov (United States)

Madsen, Nina A H; Aarsæther, Karl G; Herrmann, Bent

2017-01-01

Demersal Seining is an active fishing method applying two long seine ropes and a seine net. Demersal seining relies on fish responding to the seine rope as it moves during the fishing process. The seine ropes and net are deployed in a specific pattern encircling an area on the seabed. In some variants of demersal seining the haul-in procedure includes a towing phase where the fishing vessel moves forward before starting to winch in the seine ropes. The initial seine rope encircled area, the gradual change in it during the haul-in process and the fish's reaction to the moving seine ropes play an important role in the catch performance of demersal seine fishing. The current study investigates this subject by applying computer simulation models for demersal seine fishing. The demersal seine fishing is dynamic in nature and therefore a dynamic model, SeineSolver is applied for simulating the physical behaviour of the seine ropes during the fishing process. Information about the seine rope behaviour is used as input to another simulation tool, SeineFish that predicts the catch performance of the demersal seine fishing process. SeineFish implements a simple model for how fish at the seabed reacts to an approaching seine rope. Here, the SeineSolver and SeineFish tools are applied to investigate catching performance for a Norwegian demersal seine fishery targeting cod (Gadus morhua) in the coastal zone. The effect of seine rope layout pattern and the duration of the towing phase are investigated. Among the four different layout patterns investigated, the square layout pattern was predicted to perform best; catching 69%-86% more fish than would be obtained with the rectangular layout pattern. Inclusion of a towing phase in the fishing process was found to increase the catch performance for all layout patterns. For the square layout pattern, inclusion of a towing phase of 15 or 35 minutes increased the catch performance by respectively 37% and 48% compared to fishing without

Cepheids Geometrical Distances Using Space Interferometry

Science.gov (United States)

Marengo, M.; Karovska, M.; Sasselov, D. D.; Sanchez, M.

2004-05-01

A space based interferometer with a sub-milliarcsecond resolution in the UV-optical will provide a new avenue for the calibration of primary distance indicators with unprecedented accuracy, by allowing very accurate and stable measurements of Cepheids pulsation amplitudes at wavelengths not accessible from the ground. Sasselov & Karovska (1994) have shown that interferometers allow very accurate measurements of Cepheids distances by using a ``geometric'' variant of the Baade-Wesselink method. This method has been succesfully applied to derive distances and radii of nearby Cepheids using ground-based near-IR and optical interferometers, within a 15% accuracy level. Our study shows that the main source of error in these measurements is due to the perturbing effects of the Earth atmosphere, which is the limiting factor in the interferometer stability. A space interferometer will not suffer from this intrinsic limitations, and can potentially lead to improve astronomical distance measurements by an order of magnitude in precision. We discuss here the technical requirements that a space based facility will need to carry out this project, allowing distance measurements within a few percent accuracy level. We will finally discuss how a sub-milliarcsecond resolution will allow the direct distance determination for hundreds of galactic sources, and provide a substantial improvement in the zero-point of the Cepheid distance scale.

THE WEIGHTED POINCARÉ DISTANCE IN THE HALF PLANE

OpenAIRE

Byun, Jisoo; Baek, Seung Min; Cho, Hong Rae; Lee, Han-Wool

2014-01-01

In this paper we introduce the weighted Poincaré distance and the induced distance by the weighted Bloch type space. We prove that the weighted Poincaré distance is identical to the inner distance generated by the induced distance.

Measuring distances between complex networks

International Nuclear Information System (INIS)

Andrade, Roberto F.S.; Miranda, Jose G.V.; Pinho, Suani T.R.; Lobao, Thierry Petit

2008-01-01

A previously introduced concept of higher order neighborhoods in complex networks, [R.F.S. Andrade, J.G.V. Miranda, T.P. Lobao, Phys. Rev. E 73 (2006) 046101] is used to define a distance between networks with the same number of nodes. With such measure, expressed in terms of the matrix elements of the neighborhood matrices of each network, it is possible to compare, in a quantitative way, how far apart in the space of neighborhood matrices two networks are. The distance between these matrices depends on both the network topologies and the adopted node numberings. While the numbering of one network is fixed, a Monte Carlo algorithm is used to find the best numbering of the other network, in the sense that it minimizes the distance between the matrices. The minimal value found for the distance reflects differences in the neighborhood structures of the two networks that arise only from distinct topologies. This procedure ends up by providing a projection of the first network on the pattern of the second one. Examples are worked out allowing for a quantitative comparison for distances among distinct networks, as well as among distinct realizations of random networks

Computing Distances between Probabilistic Automata

Directory of Open Access Journals (Sweden)

Mathieu Tracol

2011-07-01

Full Text Available We present relaxed notions of simulation and bisimulation on Probabilistic Automata (PA, that allow some error epsilon. When epsilon is zero we retrieve the usual notions of bisimulation and simulation on PAs. We give logical characterisations of these notions by choosing suitable logics which differ from the elementary ones, L with negation and L without negation, by the modal operator. Using flow networks, we show how to compute the relations in PTIME. This allows the definition of an efficiently computable non-discounted distance between the states of a PA. A natural modification of this distance is introduced, to obtain a discounted distance, which weakens the influence of long term transitions. We compare our notions of distance to others previously defined and illustrate our approach on various examples. We also show that our distance is not expansive with respect to process algebra operators. Although L without negation is a suitable logic to characterise epsilon-(bisimulation on deterministic PAs, it is not for general PAs; interestingly, we prove that it does characterise weaker notions, called a priori epsilon-(bisimulation, which we prove to be NP-difficult to decide.

A tentative theory of large distance physics

International Nuclear Information System (INIS)

Friedan, Daniel

2003-01-01

A theoretical mechanism is devised to determine the large distance physics of spacetime. It is a two dimensional nonlinear model, the lambda model, set to govern the string world surface in an attempt to remedy the failure of string theory, as it stands. The lambda model is formulated to cancel the infrared divergent effects of handles at short distance on the world surface. The target manifold is the manifold of background spacetimes. The coupling strength is the spacetime coupling constant. The lambda model operates at 2d distance Δ -1 , very much shorter than the 2d distance μ -1 where the world surface is seen. A large characteristic spacetime distance L is given by L 2 ln(Δ/μ). Spacetime fields of wave number up to 1=L are the local coordinates for the manifold of spacetimes. The distribution of fluctuations at 2d distances shorter than Δ -1 gives the a priori measure on the target manifold, the manifold of spacetimes. If this measure concentrates at a macroscopic spacetime, then, nearby, it is a measure on the spacetime fields. The lambda model thereby constructs a spacetime quantum field theory, cutoff at ultraviolet distance L, describing physics at distances larger than L. The lambda model also constructs an effective string theory with infrared cutoff L, describing physics at distances smaller than L. The lambda model evolves outward from zero 2d distance, Δ -1 = 0, building spacetime physics starting from L ∞ and proceeding downward in L. L can be taken smaller than any distance practical for experiments, so the lambda model, if right, gives all actually observable physics. The harmonic surfaces in the manifold of spacetimes are expected to have novel nonperturbative effects at large distances. (author)

Analysing designed experiments in distance sampling

Science.gov (United States)

Stephen T. Buckland; Robin E. Russell; Brett G. Dickson; Victoria A. Saab; Donal N. Gorman; William M. Block

2009-01-01

Distance sampling is a survey technique for estimating the abundance or density of wild animal populations. Detection probabilities of animals inherently differ by species, age class, habitats, or sex. By incorporating the change in an observer's ability to detect a particular class of animals as a function of distance, distance sampling leads to density estimates...

Permutation-invariant distance between atomic configurations

Science.gov (United States)

Ferré, Grégoire; Maillet, Jean-Bernard; Stoltz, Gabriel

2015-09-01

We present a permutation-invariant distance between atomic configurations, defined through a functional representation of atomic positions. This distance enables us to directly compare different atomic environments with an arbitrary number of particles, without going through a space of reduced dimensionality (i.e., fingerprints) as an intermediate step. Moreover, this distance is naturally invariant through permutations of atoms, avoiding the time consuming associated minimization required by other common criteria (like the root mean square distance). Finally, the invariance through global rotations is accounted for by a minimization procedure in the space of rotations solved by Monte Carlo simulated annealing. A formal framework is also introduced, showing that the distance we propose verifies the property of a metric on the space of atomic configurations. Two examples of applications are proposed. The first one consists in evaluating faithfulness of some fingerprints (or descriptors), i.e., their capacity to represent the structural information of a configuration. The second application concerns structural analysis, where our distance proves to be efficient in discriminating different local structures and even classifying their degree of similarity.

Permutation-invariant distance between atomic configurations

International Nuclear Information System (INIS)

Ferré, Grégoire; Maillet, Jean-Bernard; Stoltz, Gabriel

2015-01-01

We present a permutation-invariant distance between atomic configurations, defined through a functional representation of atomic positions. This distance enables us to directly compare different atomic environments with an arbitrary number of particles, without going through a space of reduced dimensionality (i.e., fingerprints) as an intermediate step. Moreover, this distance is naturally invariant through permutations of atoms, avoiding the time consuming associated minimization required by other common criteria (like the root mean square distance). Finally, the invariance through global rotations is accounted for by a minimization procedure in the space of rotations solved by Monte Carlo simulated annealing. A formal framework is also introduced, showing that the distance we propose verifies the property of a metric on the space of atomic configurations. Two examples of applications are proposed. The first one consists in evaluating faithfulness of some fingerprints (or descriptors), i.e., their capacity to represent the structural information of a configuration. The second application concerns structural analysis, where our distance proves to be efficient in discriminating different local structures and even classifying their degree of similarity

Distance learning: its advantages and disadvantages

OpenAIRE

KEGEYAN SVETLANA ERIHOVNA

2016-01-01

Distance learning has become popular in higher institutions because of its flexibility and availability to learners and teachers at anytime, regardless of geographic location. With so many definitions and phases of distance education, this paper only focuses on the delivery mode of distance education (the use of information technology), background, and its disadvantages and advantages for today’s learners.

Modern Geometric Methods of Distance Determination

Science.gov (United States)

Thévenin, Frédéric; Falanga, Maurizio; Kuo, Cheng Yu; Pietrzyński, Grzegorz; Yamaguchi, Masaki

2017-11-01

Building a 3D picture of the Universe at any distance is one of the major challenges in astronomy, from the nearby Solar System to distant Quasars and galaxies. This goal has forced astronomers to develop techniques to estimate or to measure the distance of point sources on the sky. While most distance estimates used since the beginning of the 20th century are based on our understanding of the physics of objects of the Universe: stars, galaxies, QSOs, the direct measures of distances are based on the geometric methods as developed in ancient Greece: the parallax, which has been applied to stars for the first time in the mid-19th century. In this review, different techniques of geometrical astrometry applied to various stellar and cosmological (Megamaser) objects are presented. They consist in parallax measurements from ground based equipment or from space missions, but also in the study of binary stars or, as we shall see, of binary systems in distant extragalactic sources using radio telescopes. The Gaia mission will be presented in the context of stellar physics and galactic structure, because this key space mission in astronomy will bring a breakthrough in our understanding of stars, galaxies and the Universe in their nature and evolution with time. Measuring the distance to a star is the starting point for an unbiased description of its physics and the estimate of its fundamental parameters like its age. Applying these studies to candles such as the Cepheids will impact our large distance studies and calibration of other candles. The text is constructed as follows: introducing the parallax concept and measurement, we shall present briefly the Gaia satellite which will be the future base catalogue of stellar astronomy in the near future. Cepheids will be discussed just after to demonstrate the state of the art in distance measurements in the Universe with these variable stars, with the objective of 1% of error in distances that could be applied to our closest

Trends and Issues in Distance Education: International Perspectives

Directory of Open Access Journals (Sweden)

Erhan EROGLU

2006-04-01

Full Text Available Trends and Issues in Distance Education: International Perspectives Edited by Yusra Laila Visser, Lya Visser, Michael Simonsın, & Ray Amirault, 2005, United States of America: Information Age Publishing, Inc. pp. 315. ISBN 1-59311-212-2 Reviewed by Dr. Erhan EROGLU Anadolu University Eskisehir, TURKEY In this book, the terms of “distance education” has been discussed from different perspectives. The term “distance education” conjures up in many minds the image of modern, computer-enabled technology that has blossomed in only the last twenty years. Many of the lessons learned over the last century of distance education research and practice have been implemented in a wide variety of distance education programs worldwide, from higher education online learning programs in the United States to rural, radio-based instructional programs in developing countries. Distance education is truly international discipline. While it is true that the term “distance education” has a universal definiton, local distance ducation experiences are often quite idiosyncratic. This idiosyncratic nature emerges from the need to integrate distance education within the constraints, oppurtunities, and realities of spesific cultural and geographic contexts. From these local distance education experiences, educators are developing new understandings of the broader field of distance education, including the trends and issues present in the field. ORGANIZATION OF THE SECTIONS This book has been organized by thematic content into four main sections. Each of these sections represents a unique level of analysis for trends and issues in distance education. Part I presents five distinct perspectives on the state of distance education and the trends and issues of the field. First perspective of five distinct perpectives is “a survey of progressive and conservative trends in education with implications for distance education practice.” Second perspective is �

Measuring and testing dependence by correlation of distances

OpenAIRE

Székely, Gábor J.; Rizzo, Maria L.; Bakirov, Nail K.

2007-01-01

Distance correlation is a new measure of dependence between random vectors. Distance covariance and distance correlation are analogous to product-moment covariance and correlation, but unlike the classical definition of correlation, distance correlation is zero only if the random vectors are independent. The empirical distance dependence measures are based on certain Euclidean distances between sample elements rather than sample moments, yet have a compact representation analogous to the clas...

Ethnical distance in Vojvodina: Research results

Directory of Open Access Journals (Sweden)

Lazar Žolt

2005-01-01

Full Text Available This article presents the results of the ethnical distance measuring in Vojvodina, the north Province of the Republic of Serbia. The measuring was carried out on autumn 2002, during realization of the wider project of multiculturalism research in the mentioned region. According to the results the ethnical distances in Vojvodina are quite equalized and they are grouped around the attitude "all the same". Vojvodinian Serbs are more favorable partners for the majority of social contacts, and the relatively largest distance is shown toward Roma. The ethnical distance results also discovers two very important factors for understanding the interethnic relations in Vojvodina: first, the "rational" kind of social contacts with the members of the other ethnical groups are more preferable for the majority of respondents, and second, they have very equal distances toward their own ethnical groups.

Three Generations of Distance Education Pedagogy

Directory of Open Access Journals (Sweden)

Terry Anderson

2011-03-01

Full Text Available This paper defines and examines three generations of distance education pedagogy. Unlike earlier classifications of distance education based on the technology used, this analysis focuses on the pedagogy that defines the learning experiences encapsulated in the learning design. The three generations of cognitive-behaviourist, social constructivist, and connectivist pedagogy are examined, using the familiar community of inquiry model (Garrison, Anderson, & Archer, 2000 with its focus on social, cognitive, and teaching presences. Although this typology of pedagogies could also be usefully applied to campus-based education, the need for and practice of openness and explicitness in distance education content and process makes the work especially relevant to distance education designers, teachers, and developers. The article concludes that high-quality distance education exploits all three generations as determined by the learning content, context, and learning expectations.

Social Distance and Intergenerational Relations

Science.gov (United States)

Kidwell, I. Jane; Booth, Alan

1977-01-01

Questionnaires were administered to a sample of adults to assess the extent of social distance between people of different ages. The findings suggest that the greater the age difference (younger or older) between people, the greater the social distance they feel. (Author)

The Psychology of Psychic Distance

DEFF Research Database (Denmark)

Håkanson, Lars; Ambos, Björn; Schuster, Anja

2016-01-01

and their theoretical underpinnings assume psychic distances to be symmetric. Building on insights from psychology and sociology, this paper demonstrates how national factors and cognitive processes interact in the formation of asymmetric distance perceptions. The results suggest that exposure to other countries...

Cognitive Styles and Distance Education.

Science.gov (United States)

Liu, Yuliang; Ginther, Dean

1999-01-01

Considers how to adapt the design of distance education to students' cognitive styles. Discusses cognitive styles, including field dependence versus independence, holistic-analytic, sensory preference, hemispheric preferences, and Kolb's Learning Style Model; and the characteristics of distance education, including technology. (Contains 92…

Robustness of Distance-to-Default

DEFF Research Database (Denmark)

Jessen, Cathrine; Lando, David

2013-01-01

. A notable exception is a model with stochastic volatility of assets. In this case both the ranking of firms and the estimated default probabilities using distance-to-default perform significantly worse. We therefore propose a volatility adjustment of the distance-to-default measure, that significantly...

Analysis of spontaneous and bleomycin-induced chromosome damage in peripheral lymphocytes of long-haul aircrew members from Argentina

International Nuclear Information System (INIS)

Bolzan, Alejandro D.; Bianchi, Martha S.; Gimenez, Esteban M.; Flaque, Maria C. Diaz; Ciancio, Vicente R.

2008-01-01

Spontaneous and bleomycin (BLM)-induced chromosomal aberrations in G0 and G2 stages of the cell cycle have been analyzed in peripheral lymphocytes of 21 long-haul aircrew members from Argentina in order to assess BLM-induced clastogenesis as a first approach to determine the DNA repair capacity and thereby the susceptibility to environmental cancers in aircrew. The possibility that occupational exposure of flight personnel to cosmic radiation can induce an adaptive response in their peripheral lymphocytes that can be detected by a subsequent in vitro treatment with BLM was also investigated. For comparison, aberrations were also scored in the lymphocytes of 15 healthy volunteers matched by age, health, sex, drinking and smoking habits to the flight personnel group. Aircrew exhibited a higher frequency of spontaneous dicentrics and ring chromosomes than the control population (p 0.05). However, the aircrew sampled population was almost two times more sensitive to BLM G0 clastogenic effects than controls (p < 0.05). Therefore, our data suggest that chronic exposure of aircrew to cosmic radiation increases the in vitro chromosomal sensitivity of their peripheral lymphocytes to BLM (at least in the G0 stage of the cell cycle), and that occupational exposure of flight personnel to cosmic radiation does not induce an adaptive response to this radiomimetic compound. Our results justify further studies aimed at determine if those aircrew members hypersensitive to BLM are more prone to develop environmental cancer than BLM-insensitive individuals

In It for the Long Haul: Lessons from a Decade of Assessment

Science.gov (United States)

Searing, Susan E.

2013-01-01

This paper analyzes student evaluations of library orientation and information literacy instruction over a ten-year period, 2002 to 2011. The survey respondents were five hundred students who were taking or had just completed their first course in LEEP, the distance education option of the M.S. program at the University of Illinois. This case…

Distance criterion for hydrogen bond

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. Distance criterion for hydrogen bond. In a D-H ...A contact, the D...A distance must be less than the sum of van der Waals Radii of the D and A atoms, for it to be a hydrogen bond.

Distance Learning: Practice and Dilemmas

Science.gov (United States)

Tatkovic, Nevenka; Sehanovic, Jusuf; Ruzic, Maja

2006-01-01

In accordance with the European processes of integrated and homogeneous education, the paper presents the essential viewpoints and questions covering the establishment and development of "distance learning" (DL) in Republic of Croatia. It starts from the advantages of distance learning versus traditional education taking into account…

Long distance travel ‘today’

DEFF Research Database (Denmark)

Christensen, Linda

2014-01-01

This paper presents an overview of the Dane’s long distance travel. It is a part of the Drivers and Limits project about long distance travel. Long distance travel is in the project defined as infrequent travel with overnight stay. Danes 15-85 years-old travel in average 5.5 long distance travel...... per year og which a third is for international destinations, a third is for domestic second homes and a third are other domestic trips. However, 87% of the kilometres are for international destinations and only 4% are for domestic second homes. Travel activity is very uneven distributed with only half...... of the population having had a journey during the last three month. At the other hand 60% have travelled internationally during the last year and only 2% have never travelled abroad. The paper presents among other things how the travel activity is distributed on travel purpose and mode and how the mode choice...

Does Distance to Subsidiaries affect Headquarters Value Added?

DEFF Research Database (Denmark)

Nell, Phillip C.; Beugelsdijk, Sjoerd; Ambos, Björn

2014-01-01

How does distance between MNC headquarters and their subsidiaries affect the value added generated by headquarters? Integrating theories on spatial transaction costs with the headquarter view of the MNC, we link two types of distances, geographic distance and contextual distance, with headquarters...... value added. We test our hypotheses on an original dataset of 124 manufacturing subsidiaries in Europe. We find that the relation between distance and headquarters value added is conditional on the degree of subsidiaries’ external embeddedness. We find no direct effect of distance. The value added...... of headquarters is highest for subsidiaries that are not externally embedded in the host country and that operate at a large distance. It is lowest for locally responsive subsidiaries with high external embeddedness operating at a large distance. We discuss implications for the literature on headquarters-subsidiaries...

GLOBALIZATION, DISTANCE EDUCATION AND HEGEMONIC FUTURES

Directory of Open Access Journals (Sweden)

Glenn RUSSELL

2007-10-01

Full Text Available ABSTRACT Consideration of the place of theory in distance education suggests that existing definitions do not adequately account for economic, cultural and historical factors. The application of the notion of hegemonic valency to distance education highlights the ways in which tools, technological systems and online environments operate in predictable ways. Historically, the imperatives of market forces and social justice have displayed a tension that is continued in contemporary contexts including virtual learning environments. A characteristic of this tension can be seen in the forces and interactions associated with globalisation and technology. These forces, in association with others, have contributed to a null curriculum in which some alternatives open to distance education practitioners remain invisible. It is likely that this situation is further compounded by the difficulty of ascertaining what distance education practices are actually operating world-wide at any identifiable time. Available options for distance educators can be understood in terms of instrumental and interpersonal axes that can potentially indicate the relative consideration that can be given to these factors. This approach is suggested as one way to understand available options at a time when there has been an apparent increase in instrumental approaches to distance education at the expense of interpersonal approaches and issues of social justice. While this problem is of concern, it is more appropriate to reflect on the unintended consequences of distance education for society and identify them than it is to uncritically oppose globalisation and its adherents.

The facility location problem for hyper-rectilinear distances

DEFF Research Database (Denmark)

Juel, Henrik; Love, Robert F.

1985-01-01

Hyper-rectilinear distances correspond to the l p distance function for 0 travel distances between pairs of points are generally greater than rectilinear distances. In this paper we examine the single facility location problem when hyper...

Auditory/visual distance estimation: accuracy and variability

Directory of Open Access Journals (Sweden)

Paul Wallace Anderson

2014-10-01

Full Text Available Past research has shown that auditory distance estimation improves when listeners are given the opportunity to see all possible sound sources when compared to no visual input. It has also been established that distance estimation is more accurate in vision than in audition. The present study investigates the degree to which auditory distance estimation is improved when matched with a congruent visual stimulus. Virtual sound sources based on binaural room impulse response (BRIR measurements made from distances ranging from approximately 0.3 to 9.8 m in a concert hall were used as auditory stimuli. Visual stimuli were photographs taken from the listener’s perspective at each distance in the impulse response measurement setup presented on a large HDTV monitor. Listeners were asked to estimate egocentric distance to the sound source in each of three conditions: auditory only (A, visual only (V, and congruent auditory/visual stimuli (A+V. Each condition was presented within its own block. Sixty-two listeners were tested in order to quantify the response variability inherent in auditory distance perception. Distance estimates from both the V and A+V conditions were found to be considerably more accurate and less variable than estimates from the A condition.

Einstein at a distance

Energy Technology Data Exchange (ETDEWEB)

Lambourne, Robert [Department of Physics and Astronomy, Open University, Milton Keynes (United Kingdom)

2005-11-01

This paper examines the challenges and rewards that can arise when the teaching of Einsteinian physics has to be accomplished by means of distance education. The discussion is mainly based on experiences gathered over the past 35 years at the UK Open University, where special and general relativity, relativistic cosmology and other aspects of Einsteinian physics, have been taught at a variety of levels, and using a range of techniques, to students studying at a distance.

Long distance quantum teleportation

Science.gov (United States)

Xia, Xiu-Xiu; Sun, Qi-Chao; Zhang, Qiang; Pan, Jian-Wei

2018-01-01

Quantum teleportation is a core protocol in quantum information science. Besides revealing the fascinating feature of quantum entanglement, quantum teleportation provides an ultimate way to distribute quantum state over extremely long distance, which is crucial for global quantum communication and future quantum networks. In this review, we focus on the long distance quantum teleportation experiments, especially those employing photonic qubits. From the viewpoint of real-world application, both the technical advantages and disadvantages of these experiments are discussed.

Long distance signaling using axionlike particles

International Nuclear Information System (INIS)

Stancil, Daniel D.

2007-01-01

The possible existence of axionlike particles could lead to a new type of long-distance communication. In this work, basic antenna concepts are defined and a Friis-like equation is derived to facilitate long-distance link calculations. An example calculation is presented showing that communication over distances of 1000 km or more may be possible for m a aγγ >5x10 -8 GeV -1

Cardiovascular Risks in Long Distance Runners.

Science.gov (United States)

Witham, Bethany Rolfe; Babbitt, Keven

Distance running has become increasingly popular since the 1970s. Despite the health benefits, long-distance running has been associated with an increased risk for cardiac events. Healthcare professionals should be familiar with distance running cardiac risk factors and preparticipation screening recommendations from the American Heart Association, and should screen and educate patients during healthcare encounters. Nurses are particularly well suited to educate runners on risks and symptoms of cardiac dysfunction.

Continuity Properties of Distances for Markov Processes

DEFF Research Database (Denmark)

Jaeger, Manfred; Mao, Hua; Larsen, Kim Guldstrand

2014-01-01

In this paper we investigate distance functions on finite state Markov processes that measure the behavioural similarity of non-bisimilar processes. We consider both probabilistic bisimilarity metrics, and trace-based distances derived from standard Lp and Kullback-Leibler distances. Two desirable...

Virtual Bioinformatics Distance Learning Suite

Science.gov (United States)

Tolvanen, Martti; Vihinen, Mauno

2004-01-01

Distance learning as a computer-aided concept allows students to take courses from anywhere at any time. In bioinformatics, computers are needed to collect, store, process, and analyze massive amounts of biological and biomedical data. We have applied the concept of distance learning in virtual bioinformatics to provide university course material…

Quality Content in Distance Education

Science.gov (United States)

Yildiz, Ezgi Pelin; Isman, Aytekin

2016-01-01

In parallel with technological advances in today's world of education activities can be conducted without the constraints of time and space. One of the most important of these activities is distance education. The success of the distance education is possible with content quality. The proliferation of e-learning environment has brought a need for…

Distance between images

Science.gov (United States)

Gualtieri, J. A.; Le Moigne, J.; Packer, C. V.

1992-01-01

Comparing two binary images and assigning a quantitative measure to this comparison finds its purpose in such tasks as image recognition, image compression, and image browsing. This quantitative measurement may be computed by utilizing the Hausdorff distance of the images represented as two-dimensional point sets. In this paper, we review two algorithms that have been proposed to compute this distance, and we present a parallel implementation of one of them on the MasPar parallel processor. We study their complexity and the results obtained by these algorithms for two different types of images: a set of displaced pairs of images of Gaussian densities, and a comparison of a Canny edge image with several edge images from a hierarchical region growing code.

Sleep on Long Haul Layovers and Pilot Fatigue at the Start of the Next Duty Period.

Science.gov (United States)

Cosgrave, Jan; Wu, Lora J; van den Berg, Margo; Signal, T Leigh; Gander, Philippa H

2018-01-01

Layovers are critical for pilot recovery between flights and minimum layover durations are required by regulation. However, research on the factors affecting layover sleep and safety performance indicators (SPIs) before subsequent flights is relatively sparse. The present project combined data from 6 studies, including 8 long-range and 5 ultra-long range out-and-back trips across a range of different layover destinations (299 pilots in 4-person crews, 410 layovers, 1-3 d layover duration). Sleep was monitored via actigraphy from 3 d pre-trip to at least 3 d post-trip. Pilots rated their sleepiness (Karolinska Sleepiness Scale, KSS) and fatigue (Samn-Perelli scale, SP) at duty start for the inbound flight. Mixed model ANOVAs identified independent associations between fatigue and sleepiness SPIs and operational factors (domicile time of duty start for the inbound flight in six 4-h bins, layover duration, and total sleep time (TST) in the 24 h prior to inbound duty start). TST was greatest on layovers ending between 1200-1559 domicile time (time in the city from which the outbound flight departed) and TST was a significant predictor of both KSS and SP ratings at duty start for the inbound flight. TST in the 24 h prior to the inbound flight was greatest when duty start time allowed for the inclusion of a full domicile night time period. In this dataset, circadian end-time of layovers is a key determinant of pilot fatigue status at the beginning of the inbound duty period.Cosgrove J, Wu LJ, van den Berg M, Signal TL, Gander PH. Sleep on long haul layovers and pilot fatigue at the start of the next duty period. Aerosp Med Hum Perform. 2018; 89(1):19-25.

VIRTUAL LABORATORY IN DISTANCE LEARNING SYSTEM

Directory of Open Access Journals (Sweden)

Е. Kozlovsky

2011-11-01

Full Text Available Questions of designing and a choice of technologies of creation of virtual laboratory for the distance learning system are considered. Distance learning system «Kherson Virtual University» is used as illustration.

Distance Education at Conventional Universities in Germany

Directory of Open Access Journals (Sweden)

Hans-Henning Kappel

2002-01-01

Full Text Available Germany’s educational system has undergone a series of transformations during the last 40 years. In recent years, marked increases in enrolment have occurred. In response, admission requirements have been relaxed and new universities have been established.Academic distance education in the former Federal Republic of Germany (West Germany was ushered in by the educational radio broadcasts around the end of the 1960s. Aside from the formation of the FernUniversität (Open University in West Germany in 1975, there were significant developments in distance education occurring at the major universities in the German Democratic Republic (East Germany. After German reunification in 1990, the new unitary state launched programs to advance the development of distance education programs at conventional universities.Germany’s campus-based universities (Präsenzuniversitäten created various entities, including central units and consortia of universities to design and market distance education programs. Hybridisation provides the necessary prerequisites for dual mode delivery, such as basic and continuing education programs, as well as for the combination of distance and campus-based education (Präsenzstudium. Hybridisation also has also opened the door for the creation of new programs.Following an initial phase in which distance education research is expected to centralize a trend towards decentralisation is likely to follow. The German Association for Distance Education (AG-F offers a viable research network in distance education. Two dual mode case studies are also be surveyed: The Master of Arts degree, offered by the University of Koblenz-Landau, with Library Science as the second major, and the University of Kaiserslautern, where basic education will continue to be captured within the domain of the Präsenzstudium or campus-based education.The area in which distance education is flourishing most is within the field of academic continuing

Geodesic distance in planar graphs

International Nuclear Information System (INIS)

Bouttier, J.; Di Francesco, P.; Guitter, E.

2003-01-01

We derive the exact generating function for planar maps (genus zero fatgraphs) with vertices of arbitrary even valence and with two marked points at a fixed geodesic distance. This is done in a purely combinatorial way based on a bijection with decorated trees, leading to a recursion relation on the geodesic distance. The latter is solved exactly in terms of discrete soliton-like expressions, suggesting an underlying integrable structure. We extract from this solution the fractal dimensions at the various (multi)-critical points, as well as the precise scaling forms of the continuum two-point functions and the probability distributions for the geodesic distance in (multi)-critical random surfaces. The two-point functions are shown to obey differential equations involving the residues of the KdV hierarchy

Hydrogen Fueled Hybrid Solid Oxide Fuel Cell-Gas Turbine (SOFC-GT) System for Long-Haul Rail Application

Science.gov (United States)

Chow, Justin Jeff

Freight movement of goods is the artery for America's economic health. Long-haul rail is the premier mode of transport on a ton-mile basis. Concerns regarding greenhouse gas and criteria pollutant emissions, however, have motivated the creation of annually increasing locomotive emissions standards. Health issues from diesel particulate matter, especially near rail yards, have also been on the rise. These factors and the potential to raise conventional diesel-electric locomotive performance warrants the investigation of using future fuels in a more efficient system for locomotive application. This research evaluates the dynamic performance of a Solid Oxide Fuel Cell-Gas Turbine (SOFC-GT) Hybrid system operating on hydrogen fuel to power a locomotive over a rail path starting from the Port of Los Angeles and ending in the City of Barstow. Physical constraints, representative locomotive operation logic, and basic design are used from a previous feasibility study and simulations are performed in the MATLAB Simulink environment. In-house controls are adapted to and expanded upon. Results indicate high fuel-to-electricity efficiencies of at least 54% compared to a conventional diesel-electric locomotive efficiency of 35%. Incorporation of properly calibrated feedback and feed-forward controls enables substantial load following of difficult transients that result from train kinematics while maintaining turbomachinery operating requirements and suppressing thermal stresses in the fuel cell stack. The power split between the SOFC and gas turbine is deduced to be a deterministic factor in the balance between capital and operational costs. Using hydrogen results in no emissions if renewable and offers a potential of 24.2% fuel energy savings for the rail industry.

Distance Training in the European Union. ZIFF Papiere 96.

Science.gov (United States)

Keegan, Desmond

A study examined distance training in the European Union (EU) countries. First, recent literature on the following topics was reviewed: technology-supported learning, flexible and distance learning, development of open distance learning, and teleconferencing and distance learning. Next, enrollments and trends in distance learning in the EU as a…

Sensor Network Localization with Imprecise Distances

NARCIS (Netherlands)

Cao, M.; Morse, A.S.; Anderson, B.D.O.

2006-01-01

An approach to formulate geometric relations among distances between nodes as equality constraints is introduced in this paper to study the localization problem with imprecise distance information in sensor networks. These constraints can be further used to formulate optimization problems for

Distance Learning: Are We Being Realistic?

Science.gov (United States)

Oblinger, Diana; Kidwell, Jill

2000-01-01

Presents conceptual frameworks for discussing distance education. Considers the networked environment; the higher education market; rationales for distance education, including expanding access to educational and training needs; learner segments, including lifelong learners and professional development; indicators of institutional readiness;…

Institutional Distance and the Internationalization Process

DEFF Research Database (Denmark)

Pogrebnyakov, Nicolai; Maitland, Carleen

2011-01-01

This paper applies the institutional lens to the internationalization process model. It updates the concept of psychic distance in the model with a recently developed, theoretically grounded construct of institutional distance. Institutions are considered simultaneously at the national and industry...

DISTANCE LEARNING AND ATTITUDES OF GREEK BASKETBALL COACHES

Directory of Open Access Journals (Sweden)

E. Tsamourtzis

2009-01-01

Full Text Available Aim of the present research was the determination of the attitudes of Greek Basketball coaches towards their distance learning with the use of ICT in comparison with the classical learning and the examination of the perspective of their distance learning with the use of ICT. Therefore a closed questionnaire was used which included 3 different parts. 60 basketball coaches from Northern Greece comprised the sample (N=60. An interactive software was created which included the teaching of an offensive basketball system. The methodology of distance learning was used for the creation of the offensive system. The software was copied to a CD-Rom and accompanied with the questionnaires it was given to 20 Basketball coaches of Northern Greece as a pilot program. After the corrections of the primary questionnaires, the distribution of the final questionnaire accompanied with the CD-Rom followed. Multiple reciprocations were used for the data analysis. According to the results the more relaxing, easier and faster distance learning was considered in relation to the conventional one, a the fewer difficulties would the Basketball coaches face by using the distance learning method and b the friendlier and more relaxing would the distance learning method be. Also according to data research: a the more attractive the reading of software was, b the fewer the difficulties during the reading of software and c the more relaxing, easier and faster distance learning was considered in relation to the conventional one, the stronger was the perspective of Basketball coaches to believe in distance learning. In conclusion the more relaxing, easier and faster distance learning was considered in relation to the conventional one, the more positive were the attitudes of Basketball coaches towards their distance learning, while a positive perspective of Basketball coaches towards their distance learning is being formed.

Distance Teaching on Bornholm

DEFF Research Database (Denmark)

Hansen, Finn J. S.; Clausen, Christian

2001-01-01

The case study represents an example of a top-down introduction of distance teaching as part of Danish trials with the introduction of multimedia in education. The study is concerned with the background, aim and context of the trial as well as the role and working of the technology and the organi......The case study represents an example of a top-down introduction of distance teaching as part of Danish trials with the introduction of multimedia in education. The study is concerned with the background, aim and context of the trial as well as the role and working of the technology...

A CONCEPTUAL MODEL FOR EFFECTIVE DISTANCE LEARNING IN HIGHER A CONCEPTUAL MODEL FOR EFFECTIVE DISTANCE LEARNING IN HIGHER A CONCEPTUAL MODEL FOR EFFECTIVE DISTANCE LEARNING IN HIGHER EDUCATION

Directory of Open Access Journals (Sweden)

Mehran FARAJOLLAHI

2010-07-01

Full Text Available The present research aims at presenting a conceptual model for effective distance learning in higher education. Findings of this research shows that an understanding of the technological capabilities and learning theories especially constructive theory and independent learning theory and communicative and interaction theory in Distance learning is an efficient factor in the planning of effective Distance learning in higher education. Considering the theoretical foundations of the present research, in the effective distance learning model, the learner is situated at the center of learning environment. For this purpose, the learner needs to be ready for successful learning and the teacher has to be ready to design the teaching- learning activities when they initially enter the environment. In the present model, group and individual active teaching-learning approach, timely feedback, using IT and eight types of interactions have been designed with respect to theoretical foundations and current university missions. From among the issues emphasized in this model, one can refer to the Initial, Formative and Summative evaluations. In an effective distance learning environment, evaluation should be part of the learning process and the feedback resulting from it should be used to improve learning. For validating the specified features, the opinions of Distance learning experts in Payame Noor, Shiraz, Science and Technology and Amirkabir Universities have been used which verified a high percentage of the statistical sample of the above mentioned features.

Distance Learning Delivery Systems: Instructional Options.

Science.gov (United States)

Steele, Ray L.

1993-01-01

Discusses the availability of satellite and cable programing to provide distance education opportunities in school districts. Various delivery systems are described, including telephones with speakers, personal computers, and satellite dishes; and a sidebar provides a directory of distance learning opportunities, including telecommunications…

So, What is Actually the Distance from the Equator to the Pole? – Overview of the Meridian Distance Approximations

Directory of Open Access Journals (Sweden)

Adam Weintrit

2013-06-01

Full Text Available In the paper the author presents overview of the meridian distance approximations. He would like to find the answer for the question what is actually the distance from the equator to the pole - the polar distance. In spite of appearances this is not such a simple question. The problem of determining the polar distance is a great opportunity to demonstrate the multitude of possible solutions in common use. At the beginning of the paper the author discusses some approximations and a few exact expressions (infinite sums to calculate perimeter and quadrant of an ellipse, he presents convenient measurement units of the distance on the surface of the Earth, existing methods for the solution of the great circle and great elliptic sailing, and in the end he analyses and compares geodetic formulas for the meridian arc length.

Method of measuring distance between fuel element

International Nuclear Information System (INIS)

Urata, Megumu.

1991-01-01

The distance between fuel elements contained in a pool is measured in a contactless manner even for a narrow distance less than 1 mm. That is, the equipment for measuring the distance between spent fuel elements of a spent fuel assembly in a nuclear reactor comprises a optical fiber scope, a lens, an industrial TV camera and a monitor TV. The top end of the optical fiber scope is inserted between fuel elements to be measured. The state thereof is displayed on the TV screen to measure the distance between the fuel elements. The measured results are compared with a previously formed calibration curve to determine the value between the fuel elements. Then, the distance between the fuel elements can be determined in the pool of a power plant without dismantling the fuel assembly, to investigate the state of the bending and estimate the fuel working life. (I.S.)

Trapping and transportation of adult and juvenile salmon in the lower Umatilla River in northeast Oregon, 1996-1997. Umatilla River Basin Trap and Haul Program. Annual progress report, October 1996 - September 1997

International Nuclear Information System (INIS)

Zimmerman, B.; Duke, B.B.

1997-09-01

Threemile Falls Dam (Threemile Dam), located near the town of Umatilla, is the major collection and counting point for adult salmonids returning to the Umatilla River. Returning salmon and steelhead were collected at Threemile Dam from August 30, 1996 to August 26, 1997. A total of 2,477 summer steelhead (Oncorhynchus mykiss); 646 adult, 80 jack, and 606 subjack fall chinook (O. tshawytscha); 618 adult and 24 jack coho (O. kisutch); and 2,194 adult and four jack spring chinook (O. tshawytscha) were collected. All fish were trapped at the east bank facility. Of the fish collected, 22 summer steelhead; 18 adult and two jack fall chinook; five adult coho; and 407 adult and three jack spring chinook were hauled upstream from Threemile Dam. There were 2,245 summer steelhead; 70 adult, 51 jack and 520 subjack fall chinook; 593 adult and 24 jack coho; and 1,130 adult spring chinook released at Threemile Dam I In addition, 110 summer steelhead; 551 adult and 25 jack fall chinook; and 600 adult spring chinook were collected for broodstock. The Westland Canal juvenile facility (Westland), located near the town of Echo at rivermile (RM) 27, is the major collection point for outmigrating juvenile salmonids and steelhead kelts, The canal was open for a total of 210 days between December 16, 1996 and July 30, 1997. During that period, fish were bypassed back to the river 175 days and were trapped on 35 days, An estimated 1,675 pounds of juvenile fish were transported from Westland to the Umatilla River boat ramp (RM 0.5), Approximately 80% of the juveniles transported were salmonids, No steelhead kelts were hauled from Westland this year. The Threemile Dam west bank juvenile bypass was operated from October 4 to November 1, 1996 and from March 26 to July 7, 1997. The juvenile trap was not operated this year. 6 refs., 6 figs., 6 tabs

Is Distance Education a Faustian Bargain?

Science.gov (United States)

DiBiase, David

2000-01-01

Focuses on the morality of distance education in geography. States that distance education learners are a qualitatively different, older population with educational needs separate from traditional on-campus students. Argues that geography educators have a moral obligation to serve lifelong learners. Includes references. (CMK)

Can you go the distance? Attending the virtual classroom.

Science.gov (United States)

Bigony, Lorraine

2010-01-01

Distance learning via the World Wide Web offers convenience and flexibility. Online education connects nurses geographically in a manner that the traditional face-to-face learning environment lacks. Delivered in both a synchronous (real time interaction) or asynchronous (delayed interaction) format, distance programs continue to provide nurses with choice, especially in the pursuit of advanced degrees. This article explores the pros and cons of distance education, in addition to the most popular platform used in distance learning today, the Blackboard Academic Suite. Characteristics of the potential enrollee to ensure a successful distance education experience are also discussed. Distance nursing programs are here to stay. Although rigorous, the ease of accessibility makes distance learning a viable alternative for busy nurses.

Connecting in distance mentoring: communication practices that work.

Science.gov (United States)

Lasater, Kathie; Young, Patricia K; Mitchell, Claudia G; Delahoyde, Theresa M; Nick, Jan M; Siktberg, Linda

2014-04-01

As nursing and healthcare become more global, supported by technology, the opportunities for distance mentoring increase. Mentorship is critical to nurse educator recruitment and retention. The purpose of this study was to identify communication practices of nurse educators involved in mentoring at a distance. A qualitative design, utilizing in-person or telephone interviews was used. Participants were twenty-three protégés or mentors who were part of a yearlong distance mentoring program. An iterative process of hermeneutic analysis identified three themes; this paper focuses on the theme of connectedness. Participant narratives illuminate practices of connecting at a distance: meeting face-to-face, sharing personal information, experiencing reciprocity, journaling, being vulnerable, establishing one's presence, and appreciating different perspectives. Distance does not appear to limit the connecting potential leading to a meaningful mentoring relationship; rather, it offers possibilities that local mentoring relationships may not. Nurse educators in under-resourced countries, those in small programs without a cadre of senior faculty, and students in distance programs are among those who stand to benefit from distance mentoring relationships. © 2013.

Costs of Low-Scale Distance Learning Programs: A Case of Distance Learning Courses in the Aegean Islands.

Directory of Open Access Journals (Sweden)

Costas Tsolakidis

2010-03-01

Full Text Available The advance of Information and Communication Technology (ICT and the reduction of cost in digital applications motivate course designers to develop new application of distance learning programs so as to meet the increasing educational needs in the knowledge-based society. As a consequence, distance learning courses are increasing in number, credibility and acceptability all over the world. The question is whether these programs are efficient in terms of costs. The main theme of this work is to investigate cost behaviour and estimate cost efficiency of distance learning courses applied in low-inhabited, remote islands. The target group consists of high school students of Grade I. The distance learning course that is designed uses several scenarios of the “what-if form” and reaches the conclusion that cost of such solutions is far lower than that of any traditional course, even at the absence of scale economies.

[Osteoarthritis from long-distance running?].

Science.gov (United States)

Hohmann, E; Wörtler, K; Imhoff, A

2005-06-01

Long distance running has become a fashionable recreational activity. This study investigated the effects of external impact loading on bone and cartilage introduced by performing a marathon race. Seven beginners were compared to six experienced recreational long distance runners and two professional athletes. All participants underwent magnetic resonance imaging of the hip and knee before and after a marathon run. Coronal T1 weighted and STIR sequences were used. The pre MRI served as a baseline investigation and monitored the training effect. All athletes demonstrated normal findings in the pre run scan. All but one athlete in the beginner group demonstrated joint effusions after the race. The experienced and professional runners failed to demonstrate pathology in the post run scans. Recreational and professional long distance runners tolerate high impact forces well. Beginners demonstrate significant changes on the post run scans. Whether those findings are a result of inadequate training (miles and duration) warrant further studies. We conclude that adequate endurance training results in adaptation mechanisms that allow the athlete to compensate for the stresses introduced by long distance running and do not predispose to the onset of osteoarthritis. Significant malalignment of the lower extremity may cause increased focal loading of joint and cartilage.

Euclidean distance geometry an introduction

CERN Document Server

Liberti, Leo

2017-01-01

This textbook, the first of its kind, presents the fundamentals of distance geometry:  theory, useful methodologies for obtaining solutions, and real world applications. Concise proofs are given and step-by-step algorithms for solving fundamental problems efficiently and precisely are presented in Mathematica®, enabling the reader to experiment with concepts and methods as they are introduced. Descriptive graphics, examples, and problems, accompany the real gems of the text, namely the applications in visualization of graphs, localization of sensor networks, protein conformation from distance data, clock synchronization protocols, robotics, and control of unmanned underwater vehicles, to name several.  Aimed at intermediate undergraduates, beginning graduate students, researchers, and practitioners, the reader with a basic knowledge of linear algebra will gain an understanding of the basic theories of distance geometry and why they work in real life.

Measuring short distance dispersal of Alliaria petiolata and determining potential long distance dispersal mechanisms

Directory of Open Access Journals (Sweden)

Christopher A. Loebach

2018-03-01

Full Text Available Introduction Alliaria petiolata, an herbaceous plant, has invaded woodlands in North America. Its ecology has been thoroughly studied, but an overlooked aspect of its biology is seed dispersal distances and mechanisms. We measured seed dispersal distances in the field and tested if epizoochory is a potential mechanism for long-distance seed dispersal. Methods Dispersal distances were measured by placing seed traps in a sector design around three seed point sources, which consisted of 15 second-year plants transplanted within a 0.25 m radius circle. Traps were placed at intervals ranging from 0.25–3.25 m from the point source. Traps remained in the field until a majority of seeds were dispersed. Eight probability density functions were fitted to seed trap counts via maximum likelihood. Epizoochory was tested as a potential seed dispersal mechanism for A. petiolata through a combination of field and laboratory experiments. To test if small mammals transport A. petiolata seeds in their fur, experimental blocks were placed around dense A. petiolata patches. Each block contained a mammal inclusion treatment (MIT and control. The MIT consisted of a wood-frame (31 × 61× 31 cm covered in wire mesh, except for the two 31 × 31 cm ends, placed over a germination tray filled with potting soil. A pan filled with bait was placed in the center of the tray. The control frame (11 × 31 × 61 cm was placed over a germination tray and completely covered in wire mesh to exclude animal activity. Treatments were in the field for peak seed dispersal. In March, trays were moved to a greenhouse and A. petiolata seedlings were counted and then compared between treatments. To determine if A. petiolata seeds attach to raccoon (Procyon lotor and white-tailed deer (Odocoileus virginianus fur, wet and dry seeds were dropped onto wet and dry fur. Furs were rotated 180 degrees and the seeds that remained attached were counted. To measure seed retention, seeds

Three Generations of Distance Education Pedagogy

Science.gov (United States)

Anderson, Terry; Dron, Jon

2011-01-01

This paper defines and examines three generations of distance education pedagogy. Unlike earlier classifications of distance education based on the technology used, this analysis focuses on the pedagogy that defines the learning experiences encapsulated in the learning design. The three generations of cognitive-behaviourist, social constructivist,…

Handwriting individualization using distance and rarity

Science.gov (United States)

Tang, Yi; Srihari, Sargur; Srinivasan, Harish

2012-01-01

Forensic individualization is the task of associating observed evidence with a specific source. The likelihood ratio (LR) is a quantitative measure that expresses the degree of uncertainty in individualization, where the numerator represents the likelihood that the evidence corresponds to the known and the denominator the likelihood that it does not correspond to the known. Since the number of parameters needed to compute the LR is exponential with the number of feature measurements, a commonly used simplification is the use of likelihoods based on distance (or similarity) given the two alternative hypotheses. This paper proposes an intermediate method which decomposes the LR as the product of two factors, one based on distance and the other on rarity. It was evaluated using a data set of handwriting samples, by determining whether two writing samples were written by the same/different writer(s). The accuracy of the distance and rarity method, as measured by error rates, is significantly better than the distance method.

Electromagnetic distance measurement

CERN Document Server

1967-01-01

This book brings together the work of forty-eight geodesists from twenty-five countries. They discuss various new electromagnetic distance measurement (EDM) instruments - among them the Tellurometer, Geodimeter, and air- and satellite-borne systems - and investigate the complex sources of error.

Distance Education in Technological Age

OpenAIRE

R .C. SHARMA

2005-01-01

Distance Education in Technological AgeRomesh Verma (Editor), New Delhi: Anmol Publications, 2005, ISBN 81-261-2210-2, pp. 419 Reviewed by R C SHARMARegional DirectorIndira Gandhi National Open University-INDIA The advancements in information and communication technologies have brought significant changes in the way the open and distance learning are provided to the learners. The impact of such changes is quite visible in both developed and developing countries. Switching over to online mode...

Reliability of reference distances used in photogrammetry.

Science.gov (United States)

Aksu, Muge; Kaya, Demet; Kocadereli, Ilken

2010-07-01

To determine the reliability of the reference distances used for photogrammetric assessment. The sample consisted of 100 subjects with mean ages of 22.97 +/- 2.98 years. Five lateral and four frontal parameters were measured directly on the subjects' faces. For photogrammetric assessment, two reference distances for the profile view and three reference distances for the frontal view were established. Standardized photographs were taken and all the parameters that had been measured directly on the face were measured on the photographs. The reliability of the reference distances was checked by comparing direct and indirect values of the parameters obtained from the subjects' faces and photographs. Repeated measure analysis of variance (ANOVA) and Bland-Altman analyses were used for statistical assessment. For profile measurements, the indirect values measured were statistically different from the direct values except for Sn-Sto in male subjects and Prn-Sn and Sn-Sto in female subjects. The indirect values of Prn-Sn and Sn-Sto were reliable in both sexes. The poorest results were obtained in the indirect values of the N-Sn parameter for female subjects and the Sn-Me parameter for male subjects according to the Sa-Sba reference distance. For frontal measurements, the indirect values were statistically different from the direct values in both sexes except for one in male subjects. The indirect values measured were not statistically different from the direct values for Go-Go. The indirect values of Ch-Ch were reliable in male subjects. The poorest results were obtained according to the P-P reference distance. For profile assessment, the T-Ex reference distance was reliable for Prn-Sn and Sn-Sto in both sexes. For frontal assessment, Ex-Ex and En-En reference distances were reliable for Ch-Ch in male subjects.

Designing legible fonts for distance reading

DEFF Research Database (Denmark)

Beier, Sofie

2016-01-01

This chapter reviews existing knowledge on distance legibility of fonts, and finds that for optimal distance reading, letters and numbers benefit from relative wide shapes, open inner counters and a large x-height; fonts should further be widely spaced, and the weight should not be too heavy or t...

Media use in long distance friendships

NARCIS (Netherlands)

Utz, S.

2007-01-01

New media such as email and mobile phones have made it easier to maintain relationships over distances. The present paper examines which media people use to maintain long-distance friendships. The main focus lies on the comparison of email and phone. Media choice theories like media richness theory

A VLBI resolution of the Pleiades distance controversy.

Science.gov (United States)

Melis, Carl; Reid, Mark J; Mioduszewski, Amy J; Stauffer, John R; Bower, Geoffrey C

2014-08-29

Because of its proximity and its youth, the Pleiades open cluster of stars has been extensively studied and serves as a cornerstone for our understanding of the physical properties of young stars. This role is called into question by the "Pleiades distance controversy," wherein the cluster distance of 120.2 ± 1.5 parsecs (pc) as measured by the optical space astrometry mission Hipparcos is significantly different from the distance of 133.5 ± 1.2 pc derived with other techniques. We present an absolute trigonometric parallax distance measurement to the Pleiades cluster that uses very long baseline radio interferometry (VLBI). This distance of 136.2 ± 1.2 pc is the most accurate and precise yet presented for the cluster and is incompatible with the Hipparcos distance determination. Our results cement existing astrophysical models for Pleiades-age stars. Copyright © 2014, American Association for the Advancement of Science.

A Short-Range Distance Sensor with Exceptional Linearity

Science.gov (United States)

Simmons, Steven; Youngquist, Robert

2013-01-01

A sensor has been demonstrated that can measure distance over a total range of about 300 microns to an accuracy of about 0.1 nm (resolution of about 0.01 nm). This represents an exceptionally large dynamic range of operation - over 1,000,000. The sensor is optical in nature, and requires the attachment of a mirror to the object whose distance is being measured. This work resulted from actively developing a white light interferometric system to be used to measure the depths of defects in the Space Shuttle Orbiter windows. The concept was then applied to measuring distance. The concept later expanded to include spectrometer calibration. In summary, broadband (i.e., white) light is launched into a Michelson interferometer, one mirror of which is fixed and one of which is attached to the object whose distance is to be measured. The light emerging from the interferometer has traveled one of two distances: either the distance to the fixed mirror and back, or the distance to the moving mirror and back. These two light beams mix and produce an interference pattern where some wavelengths interfere constructively and some destructively. Sending this light into a spectrometer allows this interference pattern to be analyzed, yielding the net distance difference between the two paths. The unique feature of this distance sensor is its ability to measure accurately distance over a dynamic range of more than one million, the ratio of its range (about 300 microns) to its accuracy (about 0.1 nanometer). Such a large linear operating range is rare and arises here because both amplitude and phase-matching algorithms contribute to the performance. The sensor is limited by the need to attach a mirror of some kind to the object being tracked, and by the fairly small total range, but the exceptional dynamic range should make it of interest.

The effect of dynamic scheduling and routing in a solid waste management system

International Nuclear Information System (INIS)

Johansson, Ola M.

2006-01-01

Solid waste collection and hauling account for the greater part of the total cost in modern solid waste management systems. In a recent initiative, 3300 Swedish recycling containers have been fitted with level sensors and wireless communication equipment, thereby giving waste collection operators access to real-time information on the status of each container. In this study, analytical modeling and discrete-event simulation have been used to evaluate different scheduling and routing policies utilizing the real-time data. In addition to the general models developed, an empirical simulation study has been performed on the downtown recycling station system in Malmoe, Sweden. From the study, it can be concluded that dynamic scheduling and routing policies exist that have lower operating costs, shorter collection and hauling distances, and reduced labor hours compared to the static policy with fixed routes and pre-determined pick-up frequencies employed by many waste collection operators today. The results of the analytical model and the simulation models are coherent, and consistent with experiences of the waste collection operators

DISTANCE LEARNING STUDENTS’ NEED: Evaluating Interactions from Moore’s Theory of Transactional Distance

Directory of Open Access Journals (Sweden)

Rusmanizah USTATI

2013-04-01

Full Text Available This study draws on the experience from a focus group interviews under the distance learning programme known as Program Pensiswazahan Guru (PPG organized by the Malaysian Ministry of Education in collaboration with local universities and institutes of education. Its purpose is to uncover students’ perception about the platform used by International Islamic University Malaysia (IIUM which is the Learning Management System (LMS. LMS is a vital instructional medium especially for the varsity distant learners. Michael Moore’s Theory of Transactional Distance is used as the guiding framework to gain insights on learning and interactions in this e-learning setting. Teacher-student interactions are analyzed for better understanding of the phenomena under study. The findings indicate that in terms of usability LMS is perceived as a good platform to acquire information on content and to receive feedback from instructors. However, IIUM learners hope for more interactivity where learners can communicate amongst themselves beside engaging with the instructor-learner- content interactions that they currently experience via the system. This study aspires to provide insights on the significance of interactions from distance learners’ perception.

INVESTIGATING DISTANCE EDUCATION STUDENTS’ STUDY SKILLS

Directory of Open Access Journals (Sweden)

Cengiz POYRAZ

2013-10-01

Full Text Available Distance education, which is a planned way of teaching in which students and instructors are brought face to face in a classroom environment in several different ways by means of technology, has started to become widespread in many fields today. In distance education, students and instructors reside in different locations. Students can learn at their pace and control their learning path, content and load of what they have learned and evaluate it. However, they should adopt strategies for effective studying in order not to waste their time and efforts. Because study skills, motivation, time management, exam preparation and coping with exam stress have an impact on students’ success. In this context, distance education students’ study skills are foregrounded in today’s widespread use of distance education. In accordance with this, this study aims to investigate some variables which are influential on the dimensions of distance education students’ motivation, time management, exam preparation and coping with exam stress. A personal information form and the Study Skills scale were used for data collection. This study was designed in survey model and SPSS16.0 statistical package program was used for the statistical analyses of the research data. The research findings were discussed in line with the literature and some suggestions were presented for further research and researchers.

Fair Miles? The concept of 'food miles' through a sustainable development lens

Energy Technology Data Exchange (ETDEWEB)

MacGregor, James; Vorley, Bill

2006-10-15

The concept of 'food miles' presents an argument to buy goods which have travelled the shortest distance from farm to table, and to discriminate against long-haul transportation, especially air-freighted goods. The long-distance transport of food is associated with additional emissions due to increased transportation coupled with greater packaging, as well as a disconnection between the public and local farming. Furthermore, 'food miles' encapsulates (and is at the vanguard of) the climate change debate in the UK. In light of growing international concern over the speed and scale of climate change, the concept of 'food miles' has captured public attention and apparently is changing some consumers' behaviour, although only around one-third of shoppers know of the concept.

Dual-polarization multi-band optical OFDM transmission and transceiver limitations for up to 500 Gb/s uncompensated long-haul links.

Science.gov (United States)

Giacoumidis, E; Jarajreh, M A; Sygletos, S; Le, S T; Farjady, F; Tsokanos, A; Hamié, A; Pincemin, E; Jaouën, Y; Ellis, A D; Doran, N J

2014-05-05

A number of critical issues for dual-polarization single- and multi-band optical orthogonal-frequency division multiplexing (DP-SB/MB-OFDM) signals are analyzed in dispersion compensation fiber (DCF)-free long-haul links. For the first time, different DP crosstalk removal techniques are compared, the maximum transmission-reach is investigated, and the impact of subcarrier number and high-level modulation formats are explored thoroughly. It is shown, for a bit-error-rate (BER) of 10(-3), 2000 km of quaternary phase-shift keying (QPSK) DP-MB-OFDM transmission is feasible. At high launched optical powers (LOP), maximum-likelihood decoding can extend the LOP of 40 Gb/s QPSK DP-SB-OFDM at 2000 km by 1.5 dB compared to zero-forcing. For a 100 Gb/s DP-MB-OFDM system, a high number of subcarriers contribute to improved BER but at the cost of digital signal processing computational complexity, whilst by adapting the cyclic prefix length the BER can be improved for a low number of subcarriers. In addition, when 16-quadrature amplitude modulation (16QAM) is employed the digital-to-analogue/analogue-to-digital converter (DAC/ADC) bandwidth is relaxed with a degraded BER; while the 'circular' 8QAM is slightly superior to its 'rectangular' form. Finally, the transmission of wavelength-division multiplexing DP-MB-OFDM and single-carrier DP-QPSK is experimentally compared for up to 500 Gb/s showing great potential and similar performance at 1000 km DCF-free G.652 line.

Positioning for Effectiveness: Applying Marketing Concepts to Distance Education.

Science.gov (United States)

Levenburg, Nancy

1997-01-01

Demonstrates how colleges can use distance education to attract and retain a "critical mass" of learners for distance programs. Explores alternative ways to view distance education market opportunities and determine which avenues to pursue. Suggests how to be more effective in all aspects of distance education programs. (13 citations) (YKH)

Site-to-Source Finite Fault Distance Probability Distribution in Probabilistic Seismic Hazard and the Relationship Between Minimum Distances

Science.gov (United States)

Ortega, R.; Gutierrez, E.; Carciumaru, D. D.; Huesca-Perez, E.

2017-12-01

We present a method to compute the conditional and no-conditional probability density function (PDF) of the finite fault distance distribution (FFDD). Two cases are described: lines and areas. The case of lines has a simple analytical solution while, in the case of areas, the geometrical probability of a fault based on the strike, dip, and fault segment vertices is obtained using the projection of spheres in a piecewise rectangular surface. The cumulative distribution is computed by measuring the projection of a sphere of radius r in an effective area using an algorithm that estimates the area of a circle within a rectangle. In addition, we introduce the finite fault distance metrics. This distance is the distance where the maximum stress release occurs within the fault plane and generates a peak ground motion. Later, we can apply the appropriate ground motion prediction equations (GMPE) for PSHA. The conditional probability of distance given magnitude is also presented using different scaling laws. A simple model of constant distribution of the centroid at the geometrical mean is discussed, in this model hazard is reduced at the edges because the effective size is reduced. Nowadays there is a trend of using extended source distances in PSHA, however it is not possible to separate the fault geometry from the GMPE. With this new approach, it is possible to add fault rupture models separating geometrical and propagation effects.

Exploring Cloud Computing for Distance Learning

Science.gov (United States)

He, Wu; Cernusca, Dan; Abdous, M'hammed

2011-01-01

The use of distance courses in learning is growing exponentially. To better support faculty and students for teaching and learning, distance learning programs need to constantly innovate and optimize their IT infrastructures. The new IT paradigm called "cloud computing" has the potential to transform the way that IT resources are utilized and…

Writing for Distance Education. Samples Booklet.

Science.gov (United States)

International Extension Coll., Cambridge (England).

Approaches to the format, design, and layout of printed instructional materials for distance education are illustrated in 36 samples designed to accompany the manual, "Writing for Distance Education." Each sample is presented on a single page with a note pointing out its key features. Features illustrated include use of typescript layout, a comic…

Distance Synchronous Information Systems Course Delivery

Science.gov (United States)

Peslak, Alan R.; Lewis, Griffith R.; Aebli, Fred

2014-01-01

Teaching computer information systems via distance education is a challenge for both student and faculty. Much research work has been performed on methods of teaching via distance education. Today we are faced with a variety of options for course delivery. Asynchronous delivery via online or lesson instruction still remains most common. But…

Video surveillance using distance maps

Science.gov (United States)

Schouten, Theo E.; Kuppens, Harco C.; van den Broek, Egon L.

2006-02-01

Human vigilance is limited; hence, automatic motion and distance detection is one of the central issues in video surveillance. Hereby, many aspects are of importance, this paper specially addresses: efficiency, achieving real-time performance, accuracy, and robustness against various noise factors. To obtain fully controlled test environments, an artificial development center for robot navigation is introduced in which several parameters can be set (e.g., number of objects, trajectories and type and amount of noise). In the videos, for each following frame, movement of stationary objects is detected and pixels of moving objects are located from which moving objects are identified in a robust way. An Exact Euclidean Distance Map (E2DM) is utilized to determine accurately the distances between moving and stationary objects. Together with the determined distances between moving objects and the detected movement of stationary objects, this provides the input for detecting unwanted situations in the scene. Further, each intelligent object (e.g., a robot), is provided with its E2DM, allowing the object to plan its course of action. Timing results are specified for each program block of the processing chain for 20 different setups. So, the current paper presents extensive, experimentally controlled research on real-time, accurate, and robust motion detection for video surveillance, using E2DMs, which makes it a unique approach.

Analysis of spontaneous and bleomycin-induced chromosome damage in peripheral lymphocytes of long-haul aircrew members from Argentina

Energy Technology Data Exchange (ETDEWEB)

Bolzan, Alejandro D. [Laboratorio de Citogenetica y Mutagenesis, Instituto Multidisciplinario de Biologia Celular (IMBICE), C.C. 403, 1900 La Plata (Argentina); Miembro de la Carrera del Investigador Cientifico del CONICET (Argentina)], E-mail: abolzan@imbice.org.ar; Bianchi, Martha S. [Laboratorio de Citogenetica y Mutagenesis, Instituto Multidisciplinario de Biologia Celular (IMBICE), C.C. 403, 1900 La Plata (Argentina); Miembro de la Carrera del Investigador Cientifico del CONICET (Argentina); Gimenez, Esteban M.; Flaque, Maria C. Diaz [Laboratorio de Citogenetica y Mutagenesis, Instituto Multidisciplinario de Biologia Celular (IMBICE), C.C. 403, 1900 La Plata (Argentina); Ciancio, Vicente R. [Universidad Nacional de La Plata, Facultad de Ciencias Medicas, 120 y 60, 1900 La Plata (Argentina)

2008-03-01

Spontaneous and bleomycin (BLM)-induced chromosomal aberrations in G0 and G2 stages of the cell cycle have been analyzed in peripheral lymphocytes of 21 long-haul aircrew members from Argentina in order to assess BLM-induced clastogenesis as a first approach to determine the DNA repair capacity and thereby the susceptibility to environmental cancers in aircrew. The possibility that occupational exposure of flight personnel to cosmic radiation can induce an adaptive response in their peripheral lymphocytes that can be detected by a subsequent in vitro treatment with BLM was also investigated. For comparison, aberrations were also scored in the lymphocytes of 15 healthy volunteers matched by age, health, sex, drinking and smoking habits to the flight personnel group. Aircrew exhibited a higher frequency of spontaneous dicentrics and ring chromosomes than the control population (p < 0.05). BLM sensitivity test showed that aircrew and controls are equally sensitive to BLM G2 clastogenic effects, since both groups exhibited a similar frequency of chromatid breaks per cell (p > 0.05). However, the aircrew sampled population was almost two times more sensitive to BLM G0 clastogenic effects than controls (p < 0.05). Therefore, our data suggest that chronic exposure of aircrew to cosmic radiation increases the in vitro chromosomal sensitivity of their peripheral lymphocytes to BLM (at least in the G0 stage of the cell cycle), and that occupational exposure of flight personnel to cosmic radiation does not induce an adaptive response to this radiomimetic compound. Our results justify further studies aimed at determine if those aircrew members hypersensitive to BLM are more prone to develop environmental cancer than BLM-insensitive individuals.

The Concept of Distance in International Business Research

DEFF Research Database (Denmark)

Hutzschenreuter, Thomas; Kleindienst, Ingo; Lange, Sandra

2016-01-01

are affected by distance? and What aggravates or alleviates the effects of distance? Based on the review of the literature, a set of future research suggestions are developed, intended to direct attention to research questions that the authors believe are among the most pressing questions in distance research...

Contemporary Distance Education Leadership: Distance Education Leaders' Perceptions of Leadership Competencies

Science.gov (United States)

Tantchou, Pierre Orly M., Jr.

2013-01-01

This phenomenological qualitative study identified the leadership competencies that distance education (DE) leaders regard as essential to the successful administration of DE programs and courses in contemporary education. The following competencies were discussed in the study: flexibility, collaboration, active listening, communication, empathy,…

DISTANCE LEARNING: POTENTIAL APPLICATION AND DEVELOPMENT OUTLOOK

Directory of Open Access Journals (Sweden)

Yulija Mihajlovna Tsarapkina

2017-11-01

Full Text Available The article is devoted to the actual problem of distance education potential and prospects research in the Russian education system. According to the UNESCO estimates, if the current trend continues, then the number of people with a firm desire to receive an education would increase from 165 millions to 263 millions [7, 12]. Thus 98 million qualified students worldwide will be excluded from higher education due to a shortage of university seats. The purpose of the study is to analyze the historical and present state of the problem, to identify the potential and prospects of the development in distance learning within higher education. The methodological base of the research has become common methods of pedagogical sciences: pedagogical observation, survey, questionnaire, testing, comparative analysis, pedagogical experiment. The analytical review has shown several problem areas within distance learning, such as student’s motivation while distance course learning and training efficiency as compared to full-time university training. Combination of full-time training and distance learning leads to 31% enhancement of training efficiency and shows a sustainable increase of student’s motivation.

Distance Learning Plan Development: Initiating Organizational Structures

National Research Council Canada - National Science Library

Poole, Clifton

1998-01-01

.... Army distance learning plan managers to examine the DLPs they were directing. The analysis showed that neither army nor civilian distance learning plan managers used formalized requirements for organizational structure development (OSD...

Investigating Distance Education Students' Study Skills

Science.gov (United States)

Poyraz, Cengiz

2013-01-01

Distance education, which is a planned way of teaching in which students and instructors are brought face to face in a classroom environment in several different ways by means of technology, has started to become widespread in many fields today. In distance education, students and instructors reside in different locations. Students can learn at…

NASA Langley/CNU Distance Learning Programs.

Science.gov (United States)

Caton, Randall; Pinelli, Thomas E.

NASA Langley Research Center and Christopher Newport University (CNU) provide, free to the public, distance learning programs that focus on math, science, and/or technology over a spectrum of education levels from K-adult. The effort started in 1997, and currently there are a suite of five distance-learning programs. This paper presents the major…

Assessing distances and consistency of kinematics in Gaia/TGAS

Science.gov (United States)

Schönrich, Ralph; Aumer, Michael

2017-12-01

We apply the statistical methods by Schönrich, Binney & Asplund to assess the quality of distances and kinematics in the Radial Velocity Experiment (RAVE)-Tycho-Gaia Astrometric Solution (TGAS) and Large Sky Area Multiobject Fiber Spectroscopic Telescope (LAMOST)-TGAS samples of Solar neighbourhood stars. These methods yield a nominal distance accuracy of 1-2 per cent. Other than common tests on parallax accuracy, they directly test distance estimations including the effects of distance priors. We show how to construct these priors including the survey selection functions (SSFs) directly from the data. We demonstrate that neglecting the SSFs causes severe distance biases. Due to the decline of the SSFs in distance, the simple 1/parallax estimate only mildly underestimates distances. We test the accuracy of measured line-of-sight velocities (vlos) by binning the samples in the nominal vlos uncertainties. We find: (i) the LAMOST vlos have a ∼-5 km s-1 offset; (ii) the average LAMOST measurement error for vlos is ∼7 km s-1, significantly smaller than, and nearly uncorrelated with the nominal LAMOST estimates. The RAVE sample shows either a moderate distance underestimate, or an unaccounted source of vlos dispersion (e∥) from measurement errors and binary stars. For a subsample of suspected binary stars in RAVE, our methods indicate significant distance underestimates. Separating a sample in metallicity or kinematics to select thick-disc/halo stars, discriminates between distance bias and e∥. For LAMOST, this separation yields consistency with pure vlos measurement errors. We find an anomaly near longitude l ∼ (300 ± 60)° and distance s ∼ (0.32 ± 0.03) kpc on both sides of the galactic plane, which could be explained by either a localized distance error or a breathing mode.

49 CFR 372.300 - Distances and population data.

Science.gov (United States)

2010-10-01

... 49 Transportation 5 2010-10-01 2010-10-01 false Distances and population data. 372.300 Section 372..., COMMERCIAL ZONES, AND TERMINAL AREAS Terminal Areas § 372.300 Distances and population data. In the application of this subpart, distances and population data shall be determined in the same manner as provided...

A Strategic Planning Process Model for Distance Education

Science.gov (United States)

Pisel, Kenneth P.

2008-01-01

As more institutions seek to implement or expand distance learning programs, it becomes critical to integrate distance learning programs into broader strategic visions and plans. Using the informed opinion from a panel of peer-nominated experts via iterative Delphi questionnaires, a 10-phased strategic planning process model for distance education…

Distance Education in Mixed Institutions: Working towards Parity.

Science.gov (United States)

Jevons, Fred

1984-01-01

Describes organizational structure of Deakin University (which teaches on and off campus), compares distance education with face-to-face education, lists advantages of distance education, and predicts distance education will rise in status and expand in role due to its suitability for adult students and because of technological developments,…

Distance Learning For Mobile Internet Users

Directory of Open Access Journals (Sweden)

Beran NECAT

2007-04-01

Full Text Available This paper provides an overview on the current state of art in the field of Distance learning for mobile users. It mentions a large range of technologies, services and approaches that may be used to bring distance learning to mobile internet users. These technologies are supposed to considerably increase innovative e-learning solutions for the next generation. While this definitely appears to be true, I think what is not so clear are the implications for students, and lecturers etc. In this article I first evaluate distributed e-learning technologies. With some of the most vital topics, focusing on adaptive distributed e-learning for Mobile Internet Users (MIUs. I also provide a brief analysis of Broadband Network Services, Collaborative e-Learning Tools and Distributed Virtual Environments, Internet-Based Adaptive Learning Technologies and Personalised Distance Learning. I continue my discussion on to Internet Development Tools (IDTs for Distance Learning Solutions, Learning Technologies for MIUs, Semantic and Web-Based Services for Enriching Learning Interactivity, and Evaluations of Distributed Learning Technologies (DLTs.

Indo-European languages tree by Levenshtein distance

Science.gov (United States)

Serva, M.; Petroni, F.

2008-03-01

The evolution of languages closely resembles the evolution of haploid organisms. This similarity has been recently exploited (Gray R. D. and Atkinson Q. D., Nature, 426 (2003) 435; Gray R. D. and Jordan F. M., Nature, 405 (2000) 1052) to construct language trees. The key point is the definition of a distance among all pairs of languages which is the analogous of a genetic distance. Many methods have been proposed to define these distances; one of these, used by glottochronology, computes the distance from the percentage of shared "cognates". Cognates are words inferred to have a common historical origin, and subjective judgment plays a relevant role in the identification process. Here we push closer the analogy with evolutionary biology and we introduce a genetic distance among language pairs by considering a renormalized Levenshtein distance among words with same meaning and averaging on all words contained in a Swadesh list (Swadesh M., Proc. Am. Philos. Soc., 96 (1952) 452). The subjectivity of process is consistently reduced and the reproducibility is highly facilitated. We test our method against the Indo-European group considering fifty different languages and the two hundred words of the Swadesh list for any of them. We find out a tree which closely resembles the one published in Gray and Atkinson (2003), with some significant differences.

Distance-Based Opportunistic Mobile Data Offloading.

Science.gov (United States)

Lu, Xiaofeng; Lio, Pietro; Hui, Pan

2016-06-15

Cellular network data traffic can be offload onto opportunistic networks. This paper proposes a Distance-based Opportunistic Publish/Subscribe (DOPS) content dissemination model, which is composed of three layers: application layer, decision-making layer and network layer. When a user wants new content, he/she subscribes on a subscribing server. Users having the contents decide whether to deliver the contents to the subscriber based on the distance information. If in the meantime a content owner has traveled further in the immediate past time than the distance between the owner and the subscriber, the content owner will send the content to the subscriber through opportunistic routing. Simulations provide an evaluation of the data traffic offloading efficiency of DOPS.

De-severing distance

DEFF Research Database (Denmark)

Jensen, Hanne Louise; de Neergaard, Maja

2016-01-01

De-severing Distance This paper draws on the growing body of mobility literature that shows how mobility can be viewed as meaningful everyday practices (Freudendal –Pedersen 2007, Cresswell 2006) this paper examines how Heidegger’s term de-severing can help us understand the everyday coping with ...

The distances of nearby cool carbon stars

International Nuclear Information System (INIS)

Bergeat, J.; Sibille, F.; Lunel, M.

1978-01-01

Distance ratios are provided for 38 cool carbon stars on the basis of a previous study (Bergeat et al., 1976 a,b,c). The validation of this distance scale is obtained through an analysis of stellar velocities. A relationship is established between proper motions and the distance scale. Luminosities and radii are derived for cool carbon stars which permit a discussion of their evolutionary status. Finally, evaluations are given for the rate of mass ejection corresponding to large graphite grains. (WL) [de

Is linear distance measured by panoramic radiography reliable?

International Nuclear Information System (INIS)

Nishikawa, Keiichi; Wakoh, Mamoru; Sano, Tsukasa; Suehiro, Atsushi; Sekine, Hideshi; Kousuge, Yuuji

2010-01-01

The objective of this study was to re-examine the reliability of distance measurements on clinical panoramic radiographs by comparing them with computed tomography (CT) images, from which the most accurate distance measurement is possible. Twenty pairs of images from patients examined both with panoramic radiography and CT for dental implant treatment planning in the premolar and molar regions of the mandible were used. The vertical linear distance between the alveolar crest and the closest mandibular canal was measured by three experienced oral radiologists on both images. The distances measured on panoramic radiographs were corrected for the magnification factor at the focal plane. Double-oblique cross-sectional images were used for CT. Pearson's correlation coefficient was calculated between distances obtained from both images. The paired t test was performed for statistical comparison. Error levels with the panoramic radiograph versus the CT image were also calculated. Pearson's correlation coefficient showed a significant strong linear correlation (R=0.90; p<0.01). However, the corrected value of distance measured on panoramic radiographs tended to be too small, and a significant difference was observed (p<0.05). The error level was approximately 10% (9.6±7.3%). Distance measurement on clinical panoramic radiographs is less reliable than CT images and cannot be recommended. (author)

Distance estimation experiment for aerial minke whale surveys

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Lars Witting

2009-09-01

Full Text Available A comparative study between aerial cue–counting and digital photography surveys for minke whales conducted in Faxaflói Bay in September 2003 is used to check the perpendicular distances estimated by the cue-counting observers. The study involved 2 aircraft with the photo plane at 1,700 feet flying above the cue–counting plane at 750 feet. The observer–based distance estimates were calculated from head angles estimated by angle-boards and declination angles estimated by declinometers. These distances were checked against image–based estimates of the perpendicular distance to the same whale. The 2 independent distance estimates were obtained for 21 sightings of minke whale, and there was a good agreement between the 2 types of estimates. The relative absolute deviations between the 2 estimates were on average 23% (se: 6%, with the errors in the observer–based distance estimates resembling that of a log-normal distribution. The linear regression of the observer–based estimates (obs on the image–based estimates (img was Obs=1.1Img (R2=0.85 with an intercept fixed at zero. There was no evidence of a distance estimation bias that could generate a positive bias in the absolute abundance estimated by cue–counting.

Computing discrete signed distance fields from triangle meshes

DEFF Research Database (Denmark)

Bærentzen, Jakob Andreas; Aanæs, Henrik

2002-01-01

A method for generating a discrete, signed 3D distance field is proposed. Distance fields are used in a number of contexts. In particular the popular level set method is usually initialized by a distance field. The main focus of our work is on simplifying the computation of the sign when generating...

Ultrametric Distance in Syntax

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Roberts Mark D.

2015-04-01

Full Text Available Phrase structure trees have a hierarchical structure. In many subjects, most notably in taxonomy such tree structures have been studied using ultrametrics. Here syntactical hierarchical phrase trees are subject to a similar analysis, which is much simpler as the branching structure is more readily discernible and switched. The ambiguity of which branching height to choose, is resolved by postulating that branching occurs at the lowest height available. An ultrametric produces a measure of the complexity of sentences: presumably the complexity of sentences increases as a language is acquired so that this can be tested. All ultrametric triangles are equilateral or isosceles. Here it is shown that X̅ structure implies that there are no equilateral triangles. Restricting attention to simple syntax a minimum ultrametric distance between lexical categories is calculated. A matrix constructed from this ultrametric distance is shown to be different than the matrix obtained from features. It is shown that the definition of C-COMMAND can be replaced by an equivalent ultrametric definition. The new definition invokes a minimum distance between nodes and this is more aesthetically satisfying than previous varieties of definitions. From the new definition of C-COMMAND follows a new definition of of the central notion in syntax namely GOVERNMENT.

Weierstrass semigroups and the Feng-Rao Distance

DEFF Research Database (Denmark)

Campillo, Antonio; Farran, Ignacio

2000-01-01

We detrmine the Feng-Rao distance for several claases of codes from algebraic geometry usingthe weierstrass semigroups......We detrmine the Feng-Rao distance for several claases of codes from algebraic geometry usingthe weierstrass semigroups...

A heuristic derivation of Minkowski distance and Lorentz transformation

International Nuclear Information System (INIS)

Hassani, Sadri

2008-01-01

Students learn new abstract concepts best when these concepts are connected through a well-designed analogy, to familiar ideas. Since the concept of the relativistic spacetime distance is highly abstract, it would be desirable to connect it to the familiar Euclidean distance, but present the latter in such a way that it makes a transparent contact with the former. Starting with some intuitive and 'obvious' assumptions concerning distance in one dimension, we 'derive' the two-dimensional Euclidean distance between two points in terms of their coordinates. Then, assuming the invariance of this distance, we deduce the (familiar) two-dimensional orthogonal coordinate transformation. We present the derivation in such a way that the transition to spacetime becomes 'self-evident.' Thus, following exactly the same procedure, we derive the Minkowskian distance and the corresponding transformation that respects the invariance of that distance, i.e., the Lorentz transformation

Optimal routing for efficient municipal solid waste transportation by using ArcGIS application in Chennai, India.

Science.gov (United States)

Sanjeevi, V; Shahabudeen, P

2016-01-01

Worldwide, about US$410 billion is spent every year to manage four billion tonnes of municipal solid wastes (MSW). Transport cost alone constitutes more than 50% of the total expenditure on solid waste management (SWM) in major cities of the developed world and the collection and transport cost is about 85% in the developing world. There is a need to improve the ability of the city administrators to manage the municipal solid wastes with least cost. Since 2000, new technologies such as geographical information system (GIS) and related optimization software have been used to optimize the haul route distances. The city limits of Chennai were extended from 175 to 426 km(2) in 2011, leading to sub-optimum levels in solid waste transportation of 4840 tonnes per day. After developing a spatial database for the whole of Chennai with 200 wards, the route optimization procedures have been run for the transport of solid wastes from 13 wards (generating nodes) to one transfer station (intermediary before landfill), using ArcGIS. The optimization process reduced the distances travelled by 9.93%. The annual total cost incurred for this segment alone is Indian Rupees (INR) 226.1 million. Savings in terms of time taken for both the current and shortest paths have also been computed, considering traffic conditions. The overall savings are thus very meaningful and call for optimization of the haul routes for the entire Chennai. © The Author(s) 2015.

Research of the stopping distance for different road conditions

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Daniel LYUBENOV

2011-01-01

Full Text Available In this paper a modern method for determination of stopping distance is represented. Application of the non-contact VBOX 3i 100Hz GPS Data Logger speed and distance measurement system is represented. A description of the total stopping distance of vehicle main components - driver reaction time, vehicle reaction time and vehicle braking capability has been made. Research of the total stopping distance of a vehicle for different road conditions has been made. The results for the stopping distance can be very useful in the expert practice.

STUDY REGARDING OFFER ON DISTANCE ACCOUNTING EDUCATION IN ROMANIA

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TEIUŞAN SORIN-CIPRIAN

2015-12-01

Full Text Available The national study programme forms of organization are: daily attendance studies, low attendance studies, and distance education. The objective of this study is to research the distance accounting education. The paper examines the offer for distance education in accounting. We identified all public and private universities who provide a study program on distance accounting education. By analysing the maximum number of students that can be schooled in distance learning and the tuition fee, comparative with full-time program, we intend to offer information to those interested in the accounting education domain.

Development of the table of initial isolation distances and protective action distances for the 2004 emergency response guidebook.

Energy Technology Data Exchange (ETDEWEB)

Brown, D. F.; Freeman, W. A.; Carhart, R. A.; Krumpolc, M.; Decision and Information Sciences; Univ. of Illinois at Chicago

2005-09-23

This report provides technical documentation for values in the Table of Initial Isolation and Protective Action Distances (PADs) in the 2004 Emergency Response Guidebook (ERG2004). The objective for choosing the PADs specified in the ERG2004 is to balance the need to adequately protect the public from exposure to potentially harmful substances against the risks and expenses that could result from overreacting to a spill. To quantify this balance, a statistical approach is adopted, whereby the best available information is used to conduct an accident scenario analysis and develop a set of up to 1,000,000 hypothetical incidents. The set accounts for differences in containers types, incident types, accident severity (i.e., amounts released), locations, times of day, times of year, and meteorological conditions. Each scenario is analyzed using detailed emission rate and atmospheric dispersion models to calculate the downwind chemical concentrations from which a 'safe distance' is determined. The safe distance is defined as the distance downwind from the source at which the chemical concentration falls below health protection criteria. The American Industrial Hygiene Association's Emergency Response Planning Guideline Level 2 (ERPG-2) or equivalent is the health criteria used. The statistical sample of safe distance values for all incidents considered in the analysis are separated into four categories: small spill/daytime release, small spill/nighttime release, large spill/daytime release, and large spill/nighttime release. The 90th-percentile safe distance values for each of these groups became the PADs that appear in the ERG2004.

Single-Image Distance Measurement by a Smart Mobile Device.

Science.gov (United States)

Chen, Shangwen; Fang, Xianyong; Shen, Jianbing; Wang, Linbo; Shao, Ling

2017-12-01

Existing distance measurement methods either require multiple images and special photographing poses or only measure the height with a special view configuration. We propose a novel image-based method that can measure various types of distance from single image captured by a smart mobile device. The embedded accelerometer is used to determine the view orientation of the device. Consequently, pixels can be back-projected to the ground, thanks to the efficient calibration method using two known distances. Then the distance in pixel is transformed to a real distance in centimeter with a linear model parameterized by the magnification ratio. Various types of distance specified in the image can be computed accordingly. Experimental results demonstrate the effectiveness of the proposed method.

Diverse effects of distance cutoff and residue interval on the performance of distance-dependent atom-pair potential in protein structure prediction.

Science.gov (United States)

Yao, Yuangen; Gui, Rong; Liu, Quan; Yi, Ming; Deng, Haiyou

2017-12-08

As one of the most successful knowledge-based energy functions, the distance-dependent atom-pair potential is widely used in all aspects of protein structure prediction, including conformational search, model refinement, and model assessment. During the last two decades, great efforts have been made to improve the reference state of the potential, while other factors that also strongly affect the performance of the potential have been relatively less investigated. Based on different distance cutoffs (from 5 to 22 Å) and residue intervals (from 0 to 15) as well as six different reference states, we constructed a series of distance-dependent atom-pair potentials and tested them on several groups of structural decoy sets collected from diverse sources. A comprehensive investigation has been performed to clarify the effects of distance cutoff and residue interval on the potential's performance. Our results provide a new perspective as well as a practical guidance for optimizing distance-dependent statistical potentials. The optimal distance cutoff and residue interval are highly related with the reference state that the potential is based on, the measurements of the potential's performance, and the decoy sets that the potential is applied to. The performance of distance-dependent statistical potential can be significantly improved when the best statistical parameters for the specific application environment are adopted.

I spy with my little eye: Analysis of airline pilots' gaze patterns in a manual instrument flight scenario.

Science.gov (United States)

Haslbeck, Andreas; Zhang, Bo

2017-09-01

The aim of this study was to analyze pilots' visual scanning in a manual approach and landing scenario. Manual flying skills suffer from increasing use of automation. In addition, predominantly long-haul pilots with only a few opportunities to practice these skills experience this decline. Airline pilots representing different levels of practice (short-haul vs. long-haul) had to perform a manual raw data precision approach while their visual scanning was recorded by an eye-tracking device. The analysis of gaze patterns, which are based on predominant saccades, revealed one main group of saccades among long-haul pilots. In contrast, short-haul pilots showed more balanced scanning using two different groups of saccades. Short-haul pilots generally demonstrated better manual flight performance and within this group, one type of scan pattern was found to facilitate the manual landing task more. Long-haul pilots tend to utilize visual scanning behaviors that are inappropriate for the manual ILS landing task. This lack of skills needs to be addressed by providing specific training and more practice. Copyright © 2017 Elsevier Ltd. All rights reserved.

Male and female contributions to behavioral isolation in darters as a function of genetic distance and color distance

Science.gov (United States)

Moran, Rachel L.; Zhou, Muchu; Catchen, Julian M.; Fuller, Rebecca C.

2017-01-01

Abstract Determining which reproductive isolating barriers arise first between geographically isolated lineages is critical to understanding allopatric speciation. We examined behavioral isolation among four recently diverged allopatric species in the orangethroat darter clade (Etheostoma: Ceasia). We also examined behavioral isolation between each Ceasia species and the sympatric rainbow darter Etheostoma caeruleum. We asked (1) is behavioral isolation present between allopatric Ceasia species, and how does this compare to behavioral isolation with E. caeruleum, (2) does male color distance and/or genetic distance predict behavioral isolation between species, and (3) what are the relative contributions of female choice, male choice, and male competition to behavioral isolation? We found that behavioral isolation, genetic differentiation, and male color pattern differentiation were present between allopatric Ceasia species. Males, but not females, discerned between conspecific and heterospecific mates. Males also directed more aggression toward conspecific rival males. The high levels of behavioral isolation among Ceasia species showed no obvious pattern with genetic distance or male color distance. However, when the E. caeruleum was included in the analysis, an association between male aggression and male color distance was apparent. We discuss the possibility that reinforcement between Ceasia and E. caeruleum is driving behavioral isolation among allopatric Ceasia species. PMID:28776645

Students’ Views of Distance Education Provision at One University

Directory of Open Access Journals (Sweden)

Nalan YILMAZ

2005-10-01

Full Text Available Students’ Views of Distance Education Provision at One University Assist. Prof. Dr. Binnur Genç ILTERAkdeniz University, Faculty of Education Prof. Dr. Mualla Bilgin AKSUInönü University, Faculty of Education Lecturer. Nalan YILMAZAkdeniz University, Faculty of Education ABSTRACT Providing university students with distance education is of great importance in the global world. Distance education provides advantages and benefits especially for students who don’t have the chance to meet lecturers from other universities face to face. Distance education connects the learner and teacher to resources that are difficult to access otherwise. It is not necessary to gather students in one classroom at the same time in a distance program. Through distance education facilities students and lecturers can store, update and transfer information very quickly. Furthermore, distance education helps save money in terms of accommodation and travel expenses. This paper describes students’ perceptions and attitudes towards distance education based on their gender, school types attended, age and access to educational technology such as computer and internet. This paper also describes the specific program used by the faculty of Law at Akdeniz University,Turkey.

Distance-Based Opportunistic Mobile Data Offloading

Directory of Open Access Journals (Sweden)

Xiaofeng Lu

2016-06-01

Full Text Available Cellular network data traffic can be offload onto opportunistic networks. This paper proposes a Distance-based Opportunistic Publish/Subscribe (DOPS content dissemination model, which is composed of three layers: application layer, decision-making layer and network layer. When a user wants new content, he/she subscribes on a subscribing server. Users having the contents decide whether to deliver the contents to the subscriber based on the distance information. If in the meantime a content owner has traveled further in the immediate past time than the distance between the owner and the subscriber, the content owner will send the content to the subscriber through opportunistic routing. Simulations provide an evaluation of the data traffic offloading efficiency of DOPS.

Correlation function of the luminosity distances

Energy Technology Data Exchange (ETDEWEB)

Biern, Sang Gyu; Yoo, Jaiyul, E-mail: sgbiern@physik.uzh.ch, E-mail: jyoo@physik.uzh.ch [Center for Theoretical Astrophysics and Cosmology, Institute for Computational Science, University of Zürich, Winterthurerstrasse 190, CH-8057, Zürich (Switzerland)

2017-09-01

We present the correlation function of the luminosity distances in a flat ΛCDM universe. Decomposing the luminosity distance fluctuation into the velocity, the gravitational potential, and the lensing contributions in linear perturbation theory, we study their individual contributions to the correlation function. The lensing contribution is important at large redshift ( z ∼> 0.5) but only for small angular separation (θ ∼< 3°), while the velocity contribution dominates over the other contributions at low redshift or at larger separation. However, the gravitational potential contribution is always subdominant at all scale, if the correct gauge-invariant expression is used. The correlation function of the luminosity distances depends significantly on the matter content, especially for the lensing contribution, thus providing a novel tool of estimating cosmological parameters.

Ultraluminous X-ray sources: new distance indicators?

Science.gov (United States)

Różańska, A.; Bresler, K.; Bełdycki, B.; Madej, J.; Adhikari, T. P.

2018-05-01

Aims: In this paper we fit the NuSTAR and XMM-Newton data of three sources: NGC 7793 P13, NGC5907 ULX1, and Circinus ULX5. Methods: Our single model contains emission from a non-spherical system: a neutron star plus an accretion disk directed towards the observer. Results: We obtained a very good fit with the reduced χ2 per degree of freedom equal to 1.08 for P13, 1.01 for ULX1, and 1.14 for ULX5. The normalization of our model constrains the distance to the source. The resulting distances are D = 3.41-0.10+0.11, 6.55-0.81+0.69, and 2.60-0.03+0.05 Mpc for P13, ULX1, and ULX5 respectively. The distances to P13 and ULX5 are in perfect agreement with previous distance measurements to their host galaxies. Conclusions: Our results confirm that P13, ULX1, and ULX5 may contain central hot neutron stars. When the outgoing emission is computed by integration over the emitting surface and successfully fitted to the data, then the resulting model normalization is the direct distance indicator.

On-the-Fly Computation of Bisimilarity Distances

DEFF Research Database (Denmark)

Bacci, Giorgio; Bacci, Giovanni; Larsen, Kim Guldstrand

2017-01-01

of Desharnais et al. between discrete-time Markov chains as an optimal solution of a linear program that can be solved by using the ellipsoid method. Inspired by their result, we propose a novel linear program characterization to compute the distance in the continuous-time setting. Differently from previous......We propose a distance between continuous-time Markov chains (CTMCs) and study the problem of computing it by comparing three different algorithmic methodologies: iterative, linear program, and on-the-fly. In a work presented at FoSSaCS'12, Chen et al. characterized the bisimilarity distance...... proposals, ours has a number of constraints that is bounded by a polynomial in the size of the CTMC. This, in particular, proves that the distance we propose can be computed in polynomial time. Despite its theoretical importance, the proposed linear program characterization turns out to be inefficient...

Improving Distance Courses: Understanding Teacher Trainees and their Learning Styles for the design of Teacher Training Courses and Materials at a Distance

Directory of Open Access Journals (Sweden)

Hisham DZAKIRIA

2004-01-01

Full Text Available Literature on distance education and teacher education seems to show that what we do not know about Distance Teacher Trainees (DTT and their learning process involved exceeds what we know about it. As more DTT enroll in distance education programmes globally, distance education providers and institutions will witness trainees coming with different backgrounds and experiences begin to take advantage of this learning opportunities. One important variable in the effectiveness of distance learning is the preference of the distance learner for a particular learning mode. A key to maintaining distance learners participation in learning lies in understanding the Learning Styles Preferences (LSP and the processes involved.This is also true for teacher training. There is much greater variation in the range of LSP and how to address them when preparing distance training materials and courses. The primary purpose of this paper is to propose ways in which individual learning differences should be accommodated when designing instructional learning materials in print for DTTs. Kolb’s (1984 model on learning cycle and styles are discussed to provide instructional design guidelines which accommodate each stage of the learning cycles and individual differences between DTT in processing and presenting information and knowledge. In addition, issues on teacher education, distance learning, individual differences, and ways in which the ‘differences’ can be accommodated when designing learning materials for DTT are also discussed. This paper resonates the idea and belief that if attempts are made to match learning styles of DTTs and andragogy with content to be learned, distance teacher educators (DTEs and instructors can develop better instructional materials with greater prospects of success. Getting to know and understand the teacher trainees and their learning process involved must first be addressed to facilitate the diverse needs of the Malaysian teacher

An adaptive distance measure for use with nonparametric models

International Nuclear Information System (INIS)

Garvey, D. R.; Hines, J. W.

2006-01-01

Distance measures perform a critical task in nonparametric, locally weighted regression. Locally weighted regression (LWR) models are a form of 'lazy learning' which construct a local model 'on the fly' by comparing a query vector to historical, exemplar vectors according to a three step process. First, the distance of the query vector to each of the exemplar vectors is calculated. Next, these distances are passed to a kernel function, which converts the distances to similarities or weights. Finally, the model output or response is calculated by performing locally weighted polynomial regression. To date, traditional distance measures, such as the Euclidean, weighted Euclidean, and L1-norm have been used as the first step in the prediction process. Since these measures do not take into consideration sensor failures and drift, they are inherently ill-suited for application to 'real world' systems. This paper describes one such LWR model, namely auto associative kernel regression (AAKR), and describes a new, Adaptive Euclidean distance measure that can be used to dynamically compensate for faulty sensor inputs. In this new distance measure, the query observations that lie outside of the training range (i.e. outside the minimum and maximum input exemplars) are dropped from the distance calculation. This allows for the distance calculation to be robust to sensor drifts and failures, in addition to providing a method for managing inputs that exceed the training range. In this paper, AAKR models using the standard and Adaptive Euclidean distance are developed and compared for the pressure system of an operating nuclear power plant. It is shown that using the standard Euclidean distance for data with failed inputs, significant errors in the AAKR predictions can result. By using the Adaptive Euclidean distance it is shown that high fidelity predictions are possible, in spite of the input failure. In fact, it is shown that with the Adaptive Euclidean distance prediction

Adaptive Distance Protection for Microgrids

DEFF Research Database (Denmark)

Lin, Hengwei; Guerrero, Josep M.; Quintero, Juan Carlos Vasquez

2015-01-01

is adopted to accelerate the tripping speed of the relays on the weak lines. The protection methodology is tested on a mid-voltage microgrid network in Aalborg, Denmark. The results show that the adaptive distance protection methodology has good selectivity and sensitivity. What is more, this system also has......Due to the increasing penetration of distributed generation resources, more and more microgrids can be found in distribution systems. This paper proposes a phasor measurement unit based distance protection strategy for microgrids in distribution system. At the same time, transfer tripping scheme...

When Do Distance Effects Become Empirically Observable?

DEFF Research Database (Denmark)

Beugelsdijk, Sjoerd; Nell, Phillip C.; Ambos, Björn

2017-01-01

Integrating distance research with the behavioral strategy literature on MNC headquarters-subsidiary relations, this paper explores how the distance between headquarters and subsidiaries relates to value added by the headquarters. We show for 124 manufacturing subsidiaries in Europe that...

The field portable gamma-ray spectrometer based on wireless communication

International Nuclear Information System (INIS)

Wang Guangxi; Lai Wanchang; Ge Liangquan; Li Dan; Yu Xinhua; Gu Shuiliang

2009-01-01

It introduces a potable multi-channel γ spectrometry based on wireless communication. The author discussed the existed inconvenience in field measurement, designed the separate structure of host and detector, developed the digital γ spectrometry detector and the application software based on PDA, and completed the short-haul wireless communication between detector and host based on bluetooth technology. The entire current of the detector is less than 180 mA through test, the distance of wireless transmission can be up to 10 meters, and the speed and functions of processing spectrum are further enhanced. (authors)

Bioenergetic constraints on tactical decision making in middle distance running.

Science.gov (United States)

Jones, A M; Whipp, B J

2002-04-01

The highest velocity that a runner can sustain during middle distance races is defined by the intersection of the runner's individual velocity-time curve and the distance-time curve. The velocity-time curve is presumably fixed at the onset of a race; however, whereas the race distance is ostensibly fixed, the actual distance-time curve is not. That is, it is possible for a runner to run further than the race distance if he or she runs wide on bends in track races. In this instance, the point of intersection of the individual velocity-time curve and the distance-time curve will move downwards and to the right, reducing the best average velocity that can be sustained for the distance. To illustrate this point, the race tactics used by the gold and silver medallists at 800 m and 5000 m in the Sydney Olympics were analysed. The paths taken by the runners were carefully tracked and the total distance they covered during the races and the average velocity they sustained over the distances they actually covered were calculated. In both the Olympic 800 m and 5000 m finals, for example, the winner was not the runner who ran at the highest average velocity in the race. Rather, the winners of these races were able to husband their metabolic resources to better effect by running closer to the actual race distance. Race results in middle distance running events are dependent not just on the energetic potential of the runners at the start of the race and their strategy for pace allocation, but also on the effect of their tactical approach to positioning on the total distance covered in the race. Middle distance runners should be conscious of minimising the distance covered in races if they wish to optimise their performance.

Psychological distance cues in online messages: Interrelatedness of probability and spatial distance

NARCIS (Netherlands)

Sungur, H.; van Koningsbruggen, G.M.; Hartmann, T.

2017-01-01

Growing evidence reveals that people rely on heuristic cues when processing online information. The current research, by adopting a construal level theory approach, examined whether psychological distance cues within online messages influence message processing. According to construal level theory,

Copyright law and distance nursing education.

Science.gov (United States)

Rhoads, Jacqueline; White, Carolyn

2008-01-01

The authors present essential information regarding the copyright law and online education. This information provides the reader specific aids to assist in designing and implementing distance education courses within the bounds of the Technology, Education, and Copyright Harmonization Act and fair use guidelines. From their research, the authors, who are distance education experts, offer a wide array of educational and legal data to inform nurse educators.

First Year Distance Transition Pedagogy: Synchronous online classrooms

Directory of Open Access Journals (Sweden)

Wendy Fasso

2013-04-01

Full Text Available The design and facilitation of distance online courses for first year students must consider both first year, and distance pedagogy. One technology with the promise to meet the needs of first year distance students is the synchronous online classroom. Teacher practice as they transition from face to face to distance environments is influenced by their private theories about technology and pedagogy. Any limitations posed by these private theories may limit in turn the technological, pedagogical and content knowledge of the teachers – TPACK. This paper reports on the case of a regional university as it transitions to online, distance learning in the first year context, with a particular focus on pedagogy in the online classroom. It contributes to the first year pedagogy literature by considering the influences of existing practice of university teachers in the transition to distance learning with a particular focus on synchronous web-based tutorials. It provides recommendations to other institutions in terms of transition strategies, the pedagogical and learning benefits that are enabled and professional development needs of teachers. Normal 0 false false false EN-AU ZH-CN X-NONE

Ministerial formation of theological students through distance education

Directory of Open Access Journals (Sweden)

Marilyn Naidoo

2012-02-01

Full Text Available Ministerial formation is a multifaceted activity involving critical thinking, the acquisition of knowledge, skills development, religious identity formation and the development of ministerial and spiritual maturity expected of church ministers. Education is not merely the accumulation of a prescribed set of academic credits but includes the holistic formation of all aspects of the individual. However, theological educators are concerned about the capacity to foster such values and skills in the distance and electronic environment. Some see distance education as ‘distancing’ the students in more significant ways than simply geographic distance. These issues are of fundamental importance for they reflect the deeper convictions of theologians that distance education may not be a suitable medium for ministerial formation. This article creates a conceptual map of the theological and pedagogical challenges for ministerial formation and highlights how the possibility of formation is being carried out in the distance-learning environment.

Femtosecond frequency comb based distance measurement in air.

Science.gov (United States)

Balling, Petr; Kren, Petr; Masika, Pavel; van den Berg, S A

2009-05-25

Interferometric measurement of distance using a femtosecond frequency comb is demonstrated and compared with a counting interferometer displacement measurement. A numerical model of pulse propagation in air is developed and the results are compared with experimental data for short distances. The relative agreement for distance measurement in known laboratory conditions is better than 10(-7). According to the model, similar precision seems feasible even for long-distance measurement in air if conditions are sufficiently known. It is demonstrated that the relative width of the interferogram envelope even decreases with the measured length, and a fringe contrast higher than 90% could be obtained for kilometer distances in air, if optimal spectral width for that length and wavelength is used. The possibility of comb radiation delivery to the interferometer by an optical fiber is shown by model and experiment, which is important from a practical point of view.

Distance still matters. The hard reality of global expansion.

Science.gov (United States)

Ghemawat, P

2001-09-01

Companies routinely overestimate the attractiveness of foreign markets. Dazzled by the sheer size of untapped markets, they lose sight of the difficulties of pioneering new, often very different territories. The problem is rooted in the analytic tools (the most prominent being country portfolio analysis, or CPA) that managers use to judge international investments. By focusing on national wealth, consumer income, and people's propensity to consume, CPA emphasizes potential sales, ignoring the costs and risks of doing business in a new market. Most of these costs and risks result from the barriers created by distance. "Distance," however, does not refer only to geography; its other dimensions can make foreign markets considerably more or less attractive. The CAGE framework of distance presented here considers four attributes: cultural distance (religious beliefs, race, social norms, and language that are different for the target country and the country of the company considering expansion); administrative or political distance (colony-colonizer links, common currency, and trade arrangements); geographic distance (the physical distance between the two countries, the size of the target country, access to waterways and the ocean, internal topography, and transportation and communications infrastructures); and economic distance (disparities in the two countries' wealth or consumer income and variations in the cost and quality of financial and other resources). This framework can help to identify the ways in which potential markets may be distant from existing ones. The article explores how (and by how much) various types of distance can affect different types of industries and shows how dramatically an explicit consideration of distance can change a company's picture of its strategic options.

Distance Measurement Methods for Improved Insider Threat Detection

Directory of Open Access Journals (Sweden)

Owen Lo

2018-01-01

Full Text Available Insider threats are a considerable problem within cyber security and it is often difficult to detect these threats using signature detection. Increasing machine learning can provide a solution, but these methods often fail to take into account changes of behaviour of users. This work builds on a published method of detecting insider threats and applies Hidden Markov method on a CERT data set (CERT r4.2 and analyses a number of distance vector methods (Damerau–Levenshtein Distance, Cosine Distance, and Jaccard Distance in order to detect changes of behaviour, which are shown to have success in determining different insider threats.

Expected sliding distance of vertical slit caisson breakwater

Science.gov (United States)

Kim, Dong Hyawn

2017-06-01

Evaluating the expected sliding distance of a vertical slit caisson breakwater is proposed. Time history for the wave load to a vertical slit caisson is made. It consists of two impulsive wave pressures followed by a smooth sinusoidal pressure. In the numerical analysis, the sliding distance for an attack of single wave was shown and the expected sliding distance during 50 years was also presented. Those results were compared with a vertical front caisson breakwater without slit. It was concluded that the sliding distance of a vertical slit caisson may be over-estimated if the wave pressure on the caisson is evaluated without considering vertical slit.

The Viability of Distance Education Science Laboratories.

Science.gov (United States)

Forinash, Kyle; Wisman, Raymond

2001-01-01

Discusses the effectiveness of offering science laboratories via distance education. Explains current delivery technologies, including computer simulations, videos, and laboratory kits sent to students; pros and cons of distance labs; the use of spreadsheets; and possibilities for new science education models. (LRW)

Deep-Focusing Time-Distance Helioseismology

Science.gov (United States)

Duvall, T. L., Jr.; Jensen, J. M.; Kosovichev, A. G.; Birch, A. C.; Fisher, Richard R. (Technical Monitor)

2001-01-01

Much progress has been made by measuring the travel times of solar acoustic waves from a central surface location to points at equal arc distance away. Depth information is obtained from the range of arc distances examined, with the larger distances revealing the deeper layers. This method we will call surface-focusing, as the common point, or focus, is at the surface. To obtain a clearer picture of the subsurface region, it would, no doubt, be better to focus on points below the surface. Our first attempt to do this used the ray theory to pick surface location pairs that would focus on a particular subsurface point. This is not the ideal procedure, as Born approximation kernels suggest that this focus should have zero sensitivity to sound speed inhomogeneities. However, the sensitivity is concentrated below the surface in a much better way than the old surface-focusing method, and so we expect the deep-focusing method to be more sensitive. A large sunspot group was studied by both methods. Inversions based on both methods will be compared.

Evaluation of Distance Measures Between Gaussian Mixture Models of MFCCs

DEFF Research Database (Denmark)

Jensen, Jesper Højvang; Ellis, Dan P. W.; Christensen, Mads Græsbøll

2007-01-01

In music similarity and in the related task of genre classification, a distance measure between Gaussian mixture models is frequently needed. We present a comparison of the Kullback-Leibler distance, the earth movers distance and the normalized L2 distance for this application. Although...

Development of automatic pre-tracking system for fillet weld based on laser trigonometry

Science.gov (United States)

Shen, Xiaoqin; Yu, Fusheng

2005-01-01

In this paper, an automatic fillet weld pre-tracking system for welding the work piece of lorry back boards with several bend in haul automobile is developed basing on laser trigonometry. The optical measuring head based on laser-PSD trigonometry is used as position sensor. It is placed in front of the traveling direction of welding wire to get the distances from welding wire to the two side boards of the welding lines, upper board and bottom board of the fillet weld respectively. A chip of AT89S52 is used as the micro controller in this system. The AC servomotors, ball-screws and straight guide rails constitute the sliding table to take welding wire move. The laser-PSD sensors pass through the vertical board, upper board and bottom board of the fillet weld when welding wire moves and then get the distance. The laser-PSD sensors output the analog signals. After A/D conversion, the digital signal is input into AT89S52 and calculated. Then the information of the position and lateral deviation of the welding wire when welding a certain position are gotten to control welding wires. So the weld pre-tracking for welding the work piece with long distance and large bend in haul automobile is realized. The position information is input into EEPROM to be saved for short time after handled by AT89S52. The information is as the welding position information as well as the speed adjusting data of the welding wire when it welds the several bend of the work piece. The practice indicates that this system has high pre-tracking precision, good anti-disturb ability, excellent reliability, easy operating ability and good adaptability to the field of production.

THE EXTRAGALACTIC DISTANCE DATABASE

International Nuclear Information System (INIS)

Tully, R. Brent; Courtois, Helene M.; Jacobs, Bradley A.; Rizzi, Luca; Shaya, Edward J.; Makarov, Dmitry I.

2009-01-01

A database can be accessed on the Web at http://edd.ifa.hawaii.edu that was developed to promote access to information related to galaxy distances. The database has three functional components. First, tables from many literature sources have been gathered and enhanced with links through a distinct galaxy naming convention. Second, comparisons of results both at the levels of parameters and of techniques have begun and are continuing, leading to increasing homogeneity and consistency of distance measurements. Third, new material is presented arising from ongoing observational programs at the University of Hawaii 2.2 m telescope, radio telescopes at Green Bank, Arecibo, and Parkes and with the Hubble Space Telescope. This new observational material is made available in tandem with related material drawn from archives and passed through common analysis pipelines.

Quantum-limited heat conduction over macroscopic distances

Science.gov (United States)

Partanen, Matti; Tan, Kuan Yen; Govenius, Joonas; Lake, Russell E.; Mäkelä, Miika K.; Tanttu, Tuomo; Möttönen, Mikko

2016-05-01

The emerging quantum technological apparatuses, such as the quantum computer, call for extreme performance in thermal engineering. Cold distant heat sinks are needed for the quantized electric degrees of freedom owing to the increasing packaging density and heat dissipation. Importantly, quantum mechanics sets a fundamental upper limit for the flow of information and heat, which is quantified by the quantum of thermal conductance. However, the short distance between the heat-exchanging bodies in the previous experiments hinders their applicability in quantum technology. Here, we present experimental observations of quantum-limited heat conduction over macroscopic distances extending to a metre. We achieved this improvement of four orders of magnitude in the distance by utilizing microwave photons travelling in superconducting transmission lines. Thus, it seems that quantum-limited heat conduction has no fundamental distance cutoff. This work establishes the integration of normal-metal components into the framework of circuit quantum electrodynamics, which provides a basis for the superconducting quantum computer. Especially, our results facilitate remote cooling of nanoelectronic devices using faraway in situ-tunable heat sinks. Furthermore, quantum-limited heat conduction is important in contemporary thermodynamics. Here, the long distance may lead to ultimately efficient mesoscopic heat engines with promising practical applications.

A Distance Measure for Genome Phylogenetic Analysis

Science.gov (United States)

Cao, Minh Duc; Allison, Lloyd; Dix, Trevor

Phylogenetic analyses of species based on single genes or parts of the genomes are often inconsistent because of factors such as variable rates of evolution and horizontal gene transfer. The availability of more and more sequenced genomes allows phylogeny construction from complete genomes that is less sensitive to such inconsistency. For such long sequences, construction methods like maximum parsimony and maximum likelihood are often not possible due to their intensive computational requirement. Another class of tree construction methods, namely distance-based methods, require a measure of distances between any two genomes. Some measures such as evolutionary edit distance of gene order and gene content are computational expensive or do not perform well when the gene content of the organisms are similar. This study presents an information theoretic measure of genetic distances between genomes based on the biological compression algorithm expert model. We demonstrate that our distance measure can be applied to reconstruct the consensus phylogenetic tree of a number of Plasmodium parasites from their genomes, the statistical bias of which would mislead conventional analysis methods. Our approach is also used to successfully construct a plausible evolutionary tree for the γ-Proteobacteria group whose genomes are known to contain many horizontally transferred genes.

Multivariate Welch t-test on distances

OpenAIRE

Alekseyenko, Alexander V.

2016-01-01

Motivation: Permutational non-Euclidean analysis of variance, PERMANOVA, is routinely used in exploratory analysis of multivariate datasets to draw conclusions about the significance of patterns visualized through dimension reduction. This method recognizes that pairwise distance matrix between observations is sufficient to compute within and between group sums of squares necessary to form the (pseudo) F statistic. Moreover, not only Euclidean, but arbitrary distances can be used. This method...

INFORMATION PROVISION OF DISTANCE LEARNING SYSTEM

Directory of Open Access Journals (Sweden)

Viacheslav M. Oleksenko

2010-09-01

Full Text Available The article deals with the results of the research concerning the relevant information resources elaborated and introduced into the pedagogical process by the author. The peculiarities of the first in Ukraine dictionary on theory and practice of distance learning, distance course “Linear Algebra” and the course-book “Linear Algebra and Analytical Geometry”, which promote the raising in quality of education and training of specialists, are revealed.

The transposition distance for phylogenetic trees

OpenAIRE

Rossello, Francesc; Valiente, Gabriel

2006-01-01

The search for similarity and dissimilarity measures on phylogenetic trees has been motivated by the computation of consensus trees, the search by similarity in phylogenetic databases, and the assessment of clustering results in bioinformatics. The transposition distance for fully resolved phylogenetic trees is a recent addition to the extensive collection of available metrics for comparing phylogenetic trees. In this paper, we generalize the transposition distance from fully resolved to arbi...

Globalization, Distance Education and Hegemonic Futures

OpenAIRE

RUSSELL, Glenn

2015-01-01

ABSTRACT Consideration of the place of theory in distance education suggests that existing definitions do not adequately account for economic, cultural and historical factors. The application of the notion of hegemonic valency to distance education highlights the ways in which tools, technological systems and online environments operate in predictable ways. Historically, the imperatives of market forces and social justice have displayed a tension that is continued in contemporary contexts inc...

Regional variation in short distance homogamy

OpenAIRE

Haandrikman, Karen; van Wissen, Leo

2011-01-01

A third of all Dutch cohabiters choose a partner from the same municipality, so-called short distance homogamy. This article analyses the regional variation in this phenomenon, and it explains this variation in terms of geographical, socioeconomic, demographic and cultural determinants. Population register data on all new cohabiters in 2004 were used. Regression methods were employed to explain spatial patterns. Regional variation in short distance homogamy is largely explained by geographica...

Distance spectrum of Indu–Bala product of graphs

Directory of Open Access Journals (Sweden)

G. Indulal

2016-12-01

Full Text Available The D-eigenvalues μ1,μ2,…,μn of a graph G of order n are the eigenvalues of its distance matrix D and form the distance spectrum or D-spectrum of G denoted by SpecD(G. Let G1 and G2 be two regular graphs. The Indu–Bala product of G1 and G2 is denoted by G1▾G2 and is obtained from two disjoint copies of the join G1∨G2 of G1 and G2 by joining the corresponding vertices in the two copies of G2. In this paper we obtain the distance spectrum of G1▾G2 in terms of the adjacency spectra of G1 and G2. We use this result to obtain a new class of distance equienergetic graphs of diameter 3. We also prove that the class of graphs Kn¯▾Kn+1¯ has integral distance spectrum.

Dialect distances based on orthographic and phonetic transcriptions

CSIR Research Space (South Africa)

Zulu, N

2006-11-01

Full Text Available , where transcription segments were compared using the algorithm. In 2003 Gooskens and Heeringa [5] calculated Levenshtein distances between 15 Norwegian dialects and compared them to the distances as perceived by Norwegian listeners... by a clustering algorithm. Figure 2 illustrates the dendrogram derived from the clustering of perceptual distances as perceived by Norwegian listeners for the 15 Norwegian dialects investigated in this research [6]. Figure 2: Dendrogram...

What Does Electronic Conferencing Afford Distance Education?

Science.gov (United States)

Barnes, Sally

2000-01-01

Discusses the use of technology for distance learning in higher education and examines the similarities and differences between face-to-face seminars and online discussions. Considers the concept of affordance in relation to information and communication technologies and distance education; and examines affordances of electronic conferencing and…

Distance-driven projection and backprojection in three dimensions

International Nuclear Information System (INIS)

De Man, Bruno; Basu, Samit

2004-01-01

Projection and backprojection are operations that arise frequently in tomographic imaging. Recently, we proposed a new method for projection and backprojection, which we call distance-driven, and that offers low arithmetic cost and a highly sequential memory access pattern. Furthermore, distance-driven projection and backprojection avoid several artefact-inducing approximations characteristic of some other methods. We have previously demonstrated the application of this method to parallel and fan beam geometries. In this paper, we extend the distance-driven framework to three dimensions and demonstrate its application to cone beam reconstruction. We also present experimental results to demonstrate the computational performance, the artefact characteristics and the noise-resolution characteristics of the distance-driven method in three dimensions

Project-Based Collaborative Learning in Distance Education

DEFF Research Database (Denmark)

Knudsen, Morten; Bajard, C.; Helbo, Jan

2003-01-01

This article describes the experiences drawn from an experiment in transferring positive experience with a project-organised on-campus engineering programme to a technology supported distance education programme. Three years of experience with the Master of Industrial Information Technology (MII)......, didactic adjustments have been made based on feedback, in particular from evaluation questionnaires. This process has been very constructive in approaching the goal: a successful model for project organized learning in distance education.......) programme indicates, however, that adjustments are required in transforming the on-campus model to distance education. The main problem is that while project work is an excellent regulator of the learning process for on-campus students, this does not seem to be the case for off-campus students. Consequently......This article describes the experiences drawn from an experiment in transferring positive experience with a project-organised on-campus engineering programme to a technology supported distance education programme. Three years of experience with the Master of Industrial Information Technology (MII...

77 FR 27015 - Distance Learning and Telemedicine Grant Program

Science.gov (United States)

2012-05-08

... DEPARTMENT OF AGRICULTURE Rural Utilities Service Distance Learning and Telemedicine Grant Program AGENCY: Rural Utilities Service, USDA. ACTION: Notice of Funding for FY 2012 of the Distance Learning and... awards for its Distance Learning and Telemedicine (DLT) Grant Program. For Fiscal Year 2012, $15 million...

The representation of object distance: evidence from neuroimaging and neuropsychology

Directory of Open Access Journals (Sweden)

Marian Berryhill

2009-11-01

Full Text Available Perceived distance in two-dimensional images relies on monocular distance cues. Here, we examined the representation of perceived object distance using a continuous carry-over adaptation design for fMRI. The task was to look at photographs of objects and make a judgment as to whether or not the item belonged in the kitchen. Importantly, this task was orthogonal to the variable of interest: the object’s perceived distance from the viewer. In Experiment 1, whole brain group analyses identified bilateral clusters in the superior occipital gyrus (approximately area V3/V3A that showed parametric adaptation to relative changes in perceived distance. In Experiment 2, retinotopic analyses confirmed that area V3A/B reflected the greatest magnitude of response to monocular changes in perceived distance. In Experiment 3, we report that the functional activations overlap with the occipito-parietal lesions in a patient with impaired distance perception, showing that the same regions monitor implied (two-dimensional and actual (three-dimensional distance. These data suggest that distance information is automatically processed even when it is task-irrelevant and that this process relies on superior occipital areas in and around area V3A.

Performance Analysis of Reuse Distance in Cooperative Broadcasting

Directory of Open Access Journals (Sweden)

Jimmi Grönkvist

2016-01-01

Full Text Available Cooperative broadcasting is a promising technique for robust broadcast with low overhead and delay in mobile ad hoc networks. The technique is attractive for mission-oriented mobile communication, where a majority of the traffic is of broadcast nature. In cooperative broadcasting, all nodes simultaneously retransmit packets. The receiver utilizes cooperative diversity in the simultaneously received signals. The retransmissions continue until all nodes are reached. After the packet has traveled a specific number of hops out from the source, denoted as reuse distance, the source node transmits a new broadcast packet in the time slot used for the previous broadcast packet. If the reuse distance is too small, interference causes packet loss in intermediate nodes. In the literature, a reuse distance of three is common. With an analysis based on a realistic interference model and real terrain data, we show that a reuse distance of at least four is necessary to avoid packet loss in sparsely connected networks, especially for high spectral efficiencies. For frequency hopping, widely used in military systems, we propose a novel method. This method almost eliminates interference for a reuse distance of three, increasing the throughput by 33% compared to systems with a reuse distance of four.

Biomechanical considerations of distance kicking in Australian Rules football.

Science.gov (United States)

Ball, Kevin

2008-01-01

Kicking for distance in Australian Rules football is an important skill. Here, I examine technical aspects that contribute to achieving maximal kick distance. Twenty-eight elite players kicked for distance while being videoed at 500 Hz. Two-dimensional digitized data of nine body landmarks and the football were used to calculate kinematic parameters from kicking foot toe-off to the instant before ball contact. Longer kick distances were associated with greater foot speeds and shank angular velocities at ball contact, larger last step lengths, and greater distances from the ground when ball contact occurred. Foot speed, shank angular velocity, and ball position relative to the support foot at ball contact were included in the best regression predicting distance. A continuum of technique was evident among the kickers. At one end, kickers displayed relatively larger knee angular velocities and smaller thigh angular velocities at ball contact. At the other end, kickers produced relatively larger thigh angular velocities and smaller knee angular velocities at ball contact. To increase kicking distance, increasing foot speed and shank angular velocity at ball contact, increasing the last step length, and optimizing ball position relative to the ground and support foot are recommended.

Mahalanobis Distance Based Iterative Closest Point

DEFF Research Database (Denmark)

Hansen, Mads Fogtmann; Blas, Morten Rufus; Larsen, Rasmus

2007-01-01

the notion of a mahalanobis distance map upon a point set with associated covariance matrices which in addition to providing correlation weighted distance implicitly provides a method for assigning correspondence during alignment. This distance map provides an easy formulation of the ICP problem that permits...... a fast optimization. Initially, the covariance matrices are set to the identity matrix, and all shapes are aligned to a randomly selected shape (equivalent to standard ICP). From this point the algorithm iterates between the steps: (a) obtain mean shape and new estimates of the covariance matrices from...... the aligned shapes, (b) align shapes to the mean shape. Three different methods for estimating the mean shape with associated covariance matrices are explored in the paper. The proposed methods are validated experimentally on two separate datasets (IMM face dataset and femur-bones). The superiority of ICP...

Applying Leadership Theories to Distance Education Leadership

Science.gov (United States)

Nworie, John

2012-01-01

The instructional delivery mode in distance education has been transitioning from the context of a physical classroom environment to a virtual learning environment or maintaining a hybrid of the two. However, most distance education programs in dual mode institutions are situated in traditional face-to-face instructional settings. Distance…

Student and Faculty Issues in Distance Education.

Science.gov (United States)

Fender, David L.

Occupational safety and health faculty and occupational safety and health professionals (i.e., the potential audience for graduate level distance education programs) were surveyed to determine the considerations for a distance education-based graduate occupational safety and health program. Findings are reported related to the demand for distance…

Three short distance structures from quantum algebras

International Nuclear Information System (INIS)

Kempf, A.

1997-01-01

Known results are reviewed and new results are given on three types of short distance structures of observables which typically appear in studies of quantum group related algebras. In particular, one of the short distance structures is shown to suggest a new mechanism for the introduction of internal symmetries

Professional development of distance education professionals (DEPs)

African Journals Online (AJOL)

Firstly, the international and national ETD and distance education contexts are described for the purpose of benchmarking, and thereafter the TSA context is described and aligned to the benchmarks. Finally, a comparison is drawn between the proposed profile of ETD practitioners at a distance education institution and the ...

Development of critical thinking skills through distance learning in ...

African Journals Online (AJOL)

Interpersonal contact between the lecturers and students improves the development of critical thinking skills. The process is hampered by the geographical distance between the lecturers and the students in the case of distance education and learning. In many cases distance learning is, however, the only option.

Fixation distance and fixation duration to vertical road signs.

Science.gov (United States)

Costa, Marco; Simone, Andrea; Vignali, Valeria; Lantieri, Claudio; Palena, Nicola

2018-05-01

The distance of first-fixation to vertical road signs was assessed in 22 participants while driving a route of 8.34 km. Fixations to road signs were recorded by a mobile eye-movement-tracking device synchronized to GPS and kinematic data. The route included 75 road signs. First-fixation distance and fixation duration distributions were positively skewed. Median distance of first-fixation was 51 m. Median fixation duration was 137 ms with a modal value of 66 ms. First-fixation distance was linearly related to speed and fixation duration. Road signs were gazed at a much closer distance than their visibility distance. In a second study a staircase procedure was used to test the presentation-time threshold that lead to a 75% accuracy in road sign identification. The threshold was 35 ms, showing that short fixations to a road signs could lead to a correct identification. Copyright © 2018 Elsevier Ltd. All rights reserved.

TOPSIS with statistical distances: A new approach to MADM

Directory of Open Access Journals (Sweden)

Vijaya Babu Vommi

2017-01-01

Full Text Available Multiple attribute decision making (MADM methods are very useful in choosing the best alternative among the available finite but conflicting alternatives. TOPSIS is one of the MADM methods, which is simple in its methodology and logic. In TOPSIS, Euclidean distances of each alternative from the positive and negative ideal solutions are utilized to find the best alternative. In literature, apart from Euclidean distances, the city block distances have also been tried to find the separations measures. In general, the attribute data are distributed with unequal ranges and also possess moderate to high correlations. Hence, in the present paper, use of statistical distances is proposed in place of Euclidean distances. Procedures to find the best alternatives are developed using statistical and weighted statistical distances respectively. The proposed methods are illustrated with some industrial problems taken from literature. Results show that the proposed methods can be used as new alternatives in MADM for choosing the best solutions.

VCSEL-based sensors for distance and velocity

Science.gov (United States)

Moench, Holger; Carpaij, Mark; Gerlach, Philipp; Gronenborn, Stephan; Gudde, Ralph; Hellmig, Jochen; Kolb, Johanna; van der Lee, Alexander

2016-03-01

VCSEL based sensors can measure distance and velocity in three dimensional space and are already produced in high quantities for professional and consumer applications. Several physical principles are used: VCSELs are applied as infrared illumination for surveillance cameras. High power arrays combined with imaging optics provide a uniform illumination of scenes up to a distance of several hundred meters. Time-of-flight methods use a pulsed VCSEL as light source, either with strong single pulses at low duty cycle or with pulse trains. Because of the sensitivity to background light and the strong decrease of the signal with distance several Watts of laser power are needed at a distance of up to 100m. VCSEL arrays enable power scaling and can provide very short pulses at higher power density. Applications range from extended functions in a smartphone over industrial sensors up to automotive LIDAR for driver assistance and autonomous driving. Self-mixing interference works with coherent laser photons scattered back into the cavity. It is therefore insensitive to environmental light. The method is used to measure target velocity and distance with very high accuracy at distances up to one meter. Single-mode VCSELs with integrated photodiode and grating stabilized polarization enable very compact and cost effective products. Besides the well know application as computer input device new applications with even higher accuracy or for speed over ground measurement in automobiles and up to 250km/h are investigated. All measurement methods exploit the known VCSEL properties like robustness, stability over temperature and the potential for packages with integrated optics and electronics. This makes VCSEL sensors ideally suited for new mass applications in consumer and automotive markets.

Intimacy, Distance Relationships and Emotional Care

OpenAIRE

Holmes, Mary

2010-01-01

The social changes surrounding individualisation and globalization impact upon our emotional and intimate lives. Geographical mobility is especially significant and its effects on relationships much debated. Distance relationships are one example of how people respond to such changes. This paper is based on an ESRC funded qualitative study of couples in distance relationships. The argument is that such forms of loving are not all about self-satisfaction, although they may prompt reflexivity a...

The Changeable Block Distance System Analysis

Science.gov (United States)

Lewiński, Andrzej; Toruń, Andrzej

The paper treats about efficiency analysis in Changeable Block Distance (CBD) System connected with wireless positioning and control of train. The analysis is based on modeling of typical ERTMS line and comparison with actual and future traffic. The calculations are related to assumed parameters of railway traffic corresponding to real time - table of distance Psary - Góra Włodowska from CMK line equipped in classic, ETCS Level 1 and ETCS with CBD systems.

Safety distance between underground natural gas and water pipeline facilities

International Nuclear Information System (INIS)

Mohsin, R.; Majid, Z.A.; Yusof, M.Z.

2014-01-01

A leaking water pipe bursting high pressure water jet in the soil will create slurry erosion which will eventually erode the adjacent natural gas pipe, thus causing its failure. The standard 300 mm safety distance used to place natural gas pipe away from water pipeline facilities needs to be reviewed to consider accidental damage and provide safety cushion to the natural gas pipe. This paper presents a study on underground natural gas pipeline safety distance via experimental and numerical approaches. The pressure–distance characteristic curve obtained from this experimental study showed that the pressure was inversely proportional to the square of the separation distance. Experimental testing using water-to-water pipeline system environment was used to represent the worst case environment, and could be used as a guide to estimate appropriate safety distance. Dynamic pressures obtained from the experimental measurement and simulation prediction mutually agreed along the high-pressure water jetting path. From the experimental and simulation exercises, zero effect distance for water-to-water medium was obtained at an estimated horizontal distance at a minimum of 1500 mm, while for the water-to-sand medium, the distance was estimated at a minimum of 1200 mm. - Highlights: • Safe separation distance of underground natural gas pipes was determined. • Pressure curve is inversely proportional to separation distance. • Water-to-water system represents the worst case environment. • Measured dynamic pressures mutually agreed with simulation results. • Safe separation distance of more than 1200 mm should be applied

Psychological influences on distance estimation in a virtual reality environment

Directory of Open Access Journals (Sweden)

Kohske eTakahashi

2013-09-01

Full Text Available Researches on embodied perception have revealed that social, psychological and physiological factors influence perception of space. While many of these influences were observed with real or highly realistic stimuli, the present work showed that even the orientation of abstract geometric objects with a non-realistic virtual environment could influence distance perception. Observers wore a head mounted display and watched virtual cones moving within an invisible cube for five seconds with their head movement recorded. Subsequently, observers estimated the distance to the cones or evaluated their friendliness. The cones either faced the observer, a target behind the cones, or random orientations. Average viewing distance to the cones varied between 1.2 and 2.0 m. At a viewing distance of 1.6 m, observers perceived cones facing them as closer than cones facing an opposite target or random orientations. Furthermore, irrespective of viewing distance, observers moved their head away from the cones more strongly and evaluated the cones as less friendly when the cones were facing observers. Similar results of distance estimation were obtained with a 3D projection onto a large screen, although the effective viewing distance was farther away. These results suggest that factors other than physical distance could influence distance perception even with non-realistic geometric objects within a virtual environment. Furthermore, the modulation of distance perception was also accompanied by changes in subjective impression and avoidance movement. We propose that cones facing an observer are perceived as socially discomforting or threatening and potentially violate an observer’s personal space, which might influence the perceived distance of cones.

The HST Key Project on the Extragalactic Distance Scale. XV. A Cepheid Distance to the Fornax Cluster and Its Implications

OpenAIRE

Madore, Barry F.; Freedman, Wendy L.; Silbermann, N.; Harding, Paul; Huchra, John; Mould, Jeremy; Graham, John; Ferrarese, Laura; Gibson, Brad; Han, Mingsheng; Hoessel, John; Hughes, Shaun; Illingworth, Garth; Phelps, Randy; Sakai, Shoko

1998-01-01

Using the Hubble Space Telescope (HST) 37 long-period Cepheid variables have been discovered in the Fornax Cluster spiral galaxy NGC 1365. The resulting V and I period-luminosity relations yield a true distance modulus of 31.35 +/- 0.07 mag, which corresponds to a distance of 18.6 +/- 0.6 Mpc. This measurement provides several routes for estimating the Hubble Constant. (1) Assuming this distance for the Fornax Cluster as a whole yields a local Hubble Constant of 70 +/-18_{random} [+/-7]_{syst...

Transforming distance education curricula through distributive leadership

Directory of Open Access Journals (Sweden)

Mike Keppell

2010-12-01

Full Text Available This paper examines a core leadership strategy for transforming learning and teaching in distance education through flexible and blended learning. It focuses on a project centred on distributive leadership that involves collaboration, shared purpose, responsibility and recognition of leadership irrespective of role or position within an organisation. Distributive leadership was a core principle in facilitating the transformation of learning and teaching through a Teaching Fellowship Scheme that empowered leaders across a regional distance education university. In parallel, a design-based research project analysed the perceptions of the Teaching Fellows in relation to blended learning, time/space, peer learning, innovation and equity issues in relation to distance education.

Distance Education Leaders in Latin America and the Caribbean

Science.gov (United States)

Torres, Patrícia Lupion; Rama, Claudio

2018-01-01

Distance higher education has only relatively recently been established in some Latin American countries, as part of wider higher education reforms. The developments of distance education have been the result of sustained efforts of leading thinkers and practitioners in the region. In this article, several leading distance education professionals…

Distance between configurations in Markov chain Monte Carlo simulations

Science.gov (United States)

Fukuma, Masafumi; Matsumoto, Nobuyuki; Umeda, Naoya

2017-12-01

For a given Markov chain Monte Carlo algorithm we introduce a distance between two configurations that quantifies the difficulty of transition from one configuration to the other configuration. We argue that the distance takes a universal form for the class of algorithms which generate local moves in the configuration space. We explicitly calculate the distance for the Langevin algorithm, and show that it certainly has desired and expected properties as distance. We further show that the distance for a multimodal distribution gets dramatically reduced from a large value by the introduction of a tempering method. We also argue that, when the original distribution is highly multimodal with large number of degenerate vacua, an anti-de Sitter-like geometry naturally emerges in the extended configuration space.

SEAT CHOICE AND DISTANCE JUDGMENT IN PUBLIC SPACES (1).

Science.gov (United States)

Neto, Olavo Avalone; Munakata, Jun

2015-10-01

This research assessed whether public space users will adopt a least-effort approach and choose a less suitable seat nearby or seek the most suitable seat, even if it is farther away from them when the decision is made. How distance assessment affects seat choice was investigated through an observational survey, which allowed the identification of behavioral patterns. Those behavioral patterns were then tested in a paired comparison experiment with 40 participants. The results showed that the effect of distance on seat choice is related to the difference in distance between the options and that a sufficient difference can cause trade-offs between distance and seat properties. The necessary difference in distance is conditioned by the activity and the seat properties.

36 CFR 13.1206 - Wildlife distance conditions.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Wildlife distance conditions. 13.1206 Section 13.1206 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE... Provisions § 13.1206 Wildlife distance conditions. (a) Approaching a bear or any large mammal within 50 yards...

36 CFR 13.604 - Wildlife distance conditions.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Wildlife distance conditions. 13.604 Section 13.604 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE... § 13.604 Wildlife distance conditions. (a) Approaching a bear or any large mammal within 50 yards is...

Distance Education for People with Visual Impairments

Science.gov (United States)

Liakou, Maria; Manousou, Evaggelia

2015-01-01

This paper studies the standards of higher Distance Education, focusing on the Hellenic Open University, for people who have visual impairments, so that it becomes fully accessible and thus helps reduce social exclusion. Specifically, it aims to study the operational context of Distance Education, the possibilities that modern technology provides…

Edit Distance to Monotonicity in Sliding Windows

DEFF Research Database (Denmark)

Chan, Ho-Leung; Lam, Tak-Wah; Lee, Lap Kei

2011-01-01

Given a stream of items each associated with a numerical value, its edit distance to monotonicity is the minimum number of items to remove so that the remaining items are non-decreasing with respect to the numerical value. The space complexity of estimating the edit distance to monotonicity of a ...

Why Do Long-Distance Travelers Have Improved Pancreatectomy Outcomes?

Science.gov (United States)

Jindal, Manila; Zheng, Chaoyi; Quadri, Humair S; Ihemelandu, Chukwuemeka U; Hong, Young K; Smith, Andrew K; Dudeja, Vikas; Shara, Nawar M; Johnson, Lynt B; Al-Refaie, Waddah B

2017-08-01

Centralization of complex surgical care has led patients to travel longer distances. Emerging evidence suggested a negative association between increased travel distance and mortality after pancreatectomy. However, the reason for this association remains largely unknown. We sought to unravel the relationships among travel distance, receiving pancreatectomy at high-volume hospitals, delayed surgery, and operative outcomes. We identified 44,476 patients who underwent pancreatectomy for neoplasms between 2004 and 2013 at the reporting facility from the National Cancer Database. Multivariable analyses were performed to examine the independent relationships between increments in travel distance mortality (30-day and long-term survival) after adjusting for patient demographics, comorbidity, cancer stage, and time trend. We then examined how additional adjustment of procedure volume affected this relationship overall and among rural patients. Median travel distance to undergo pancreatectomy increased from 16.5 to 18.7 miles (p for trend pancreatectomy, it was also related to higher odds of receiving pancreatectomy at a high-volume hospital and lower postoperative mortality. In multivariable analysis, difference in mortality among patients with varying travel distance was attenuated by adjustment for procedure volume. However, longest travel distance was still associated with a 77% lower 30-day mortality rate than shortest travel among rural patients, even when accounting for procedure volume. Our large national study found that the beneficial effect of longer travel distance on mortality after pancreatectomy is mainly attributable to increase in procedure volume. However, it can have additional benefits on rural patients that are not explained by volume. Distance can represent a surrogate for rural populations. Copyright © 2017 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Unified treatment of the luminosity distance in cosmology

International Nuclear Information System (INIS)

Yoo, Jaiyul; Scaccabarozzi, Fulvio

2016-01-01

Comparing the luminosity distance measurements to its theoretical predictions is one of the cornerstones in establishing the modern cosmology. However, as shown in Biern and Yoo, its theoretical predictions in literature are often plagued with infrared divergences and gauge-dependences. This trend calls into question the sanity of the methods used to derive the luminosity distance. Here we critically investigate four different methods—the geometric approach, the Sachs approach, the Jacobi mapping approach, and the geodesic light cone (GLC) approach to modeling the luminosity distance, and we present a unified treatment of such methods, facilitating the comparison among the methods and checking their sanity. All of these four methods, if exercised properly, can be used to reproduce the correct description of the luminosity distance.

Unified treatment of the luminosity distance in cosmology

Energy Technology Data Exchange (ETDEWEB)

Yoo, Jaiyul; Scaccabarozzi, Fulvio, E-mail: jyoo@physik.uzh.ch, E-mail: fulvio@physik.uzh.ch [Center for Theoretical Astrophysics and Cosmology, Institute for Computational Science, University of Zürich, Zürich (Switzerland)

2016-09-01

Comparing the luminosity distance measurements to its theoretical predictions is one of the cornerstones in establishing the modern cosmology. However, as shown in Biern and Yoo, its theoretical predictions in literature are often plagued with infrared divergences and gauge-dependences. This trend calls into question the sanity of the methods used to derive the luminosity distance. Here we critically investigate four different methods—the geometric approach, the Sachs approach, the Jacobi mapping approach, and the geodesic light cone (GLC) approach to modeling the luminosity distance, and we present a unified treatment of such methods, facilitating the comparison among the methods and checking their sanity. All of these four methods, if exercised properly, can be used to reproduce the correct description of the luminosity distance.

Spin physics and inclusive processes at short distances

International Nuclear Information System (INIS)

Craigie, N.S.

1982-10-01

The following aspects of spin physics at short distances are studied: 1. the factorization theorem in perturbative QCD and helicity asymmetries in inclusive processes, 2. the effect of higher order radiative corrections on helicity asymmetries, 3. the higher order power mechanism and spin asymmetries, 4. difficulties in understanding transverse spin in perturbative QCD, 5. helicity asymmetries of short distances as a means of recognizing supersymmetric interactions. Experiments are suggested for the verification of theoretical conclusions. Although spin-physics at short distances is difficult to demonstrate experimentally it may provide a valuable tool to show how perturbative QCD operates in the presence of the non-perturbative hadronic structure. It may also prove valuable to show new interactions which might occur at very short distances

Support Services for Distance Education

Directory of Open Access Journals (Sweden)

Sandra Frieden

1999-01-01

Full Text Available The creation and operation of a distance education support infrastructure requires the collaboration of virtually all administrative departments whose activities deal with students and faculty, and all participating academic departments. Implementation can build on where the institution is and design service-oriented strategies that strengthen institutional support and commitment. Issues to address include planning, faculty issues and concerns, policies and guidelines, approval processes, scheduling, training, publicity, information-line operations, informational materials, orientation and registration processes, class coordination and support, testing, evaluations, receive site management, partnerships, budgets, staffing, library and e-mail support, and different delivery modes (microwave, compressed video, radio, satellite, public television/cable, video tape and online. The process is ongoing and increasingly participative as various groups on campus begin to get involved with distance education activities. The distance education unit must continuously examine and revise its processes and procedures to maintain the academic integrity and service excellence of its programs. It’s a daunting prospect to revise the way things have been done for many years, but each department has an opportunity to respond to new ways of serving and reaching students.

Teaching Chemistry via Distance Education

Science.gov (United States)

Boschmann, Erwin

2003-06-01

This paper describes a chemistry course taught at Indiana University Purdue University, Indianapolis via television, with a Web version added later. The television format is a delivery technology; the Web is an engagement technology and is preferred since it requires student participation. The distance-laboratory component presented the greatest challenge since laboratories via distance education are not a part of the U.S. academic culture. Appropriate experiments have been developed with the consultation of experts from The Open University in the United Kingdom, Athabasca University in Canada, and Monash University in Australia. The criteria used in the development of experiments are: (1) they must be credible academic experiences equal to or better than those used on campus, (2) they must be easy to perform without supervision, (3) they must be safe, and (4) they must meet all legal requirements. An evaluation of the program using three different approaches is described. The paper concludes that technology-mediated distance education students do as well as on-campus students, but drop out at a higher rate. It is very important to communicate with students frequently, and technology tools ought to be used only if good pedagogy is enhanced by their use.

Time-Distance Helioseismology: Noise Estimation

Science.gov (United States)

Gizon, L.; Birch, A. C.

2004-10-01

As in global helioseismology, the dominant source of noise in time-distance helioseismology measurements is realization noise due to the stochastic nature of the excitation mechanism of solar oscillations. Characterizing noise is important for the interpretation and inversion of time-distance measurements. In this paper we introduce a robust definition of travel time that can be applied to very noisy data. We then derive a simple model for the full covariance matrix of the travel-time measurements. This model depends only on the expectation value of the filtered power spectrum and assumes that solar oscillations are stationary and homogeneous on the solar surface. The validity of the model is confirmed through comparison with SOHO MDI measurements in a quiet-Sun region. We show that the correlation length of the noise in the travel times is about half the dominant wavelength of the filtered power spectrum. We also show that the signal-to-noise ratio in quiet-Sun travel-time maps increases roughly as the square root of the observation time and is at maximum for a distance near half the length scale of supergranulation.

Planning with Reachable Distances

KAUST Repository

Tang, Xinyu; Thomas, Shawna; Amato, Nancy M.

2009-01-01

reachable distance space (RD-space), in which all configurations lie in the set of constraint-satisfying subspaces. This enables us to directly sample the constrained subspaces with complexity linear in the robot's number of degrees of freedom. In addition

Where does distance matter? Distance to the closest maternity unit and risk of foetal and neonatal mortality in France.

Science.gov (United States)

Pilkington, Hugo; Blondel, Béatrice; Drewniak, Nicolas; Zeitlin, Jennifer

2014-12-01

The number of maternity units has declined in France, raising concerns about the possible impact of increasing travel distances on perinatal health outcomes. We investigated impact of distance to closest maternity unit on perinatal mortality. Data from the French National Vital Statistics Registry were used to construct foetal and neonatal mortality rates over 2001-08 by distance from mother's municipality of residence and the closest municipality with a maternity unit. Data from French neonatal mortality certificates were used to compute neonatal death rates after out-of-hospital birth. Relative risks by distance were estimated, adjusting for individual and municipal-level characteristics. Seven percent of births occurred to women residing at ≥30 km from a maternity unit and 1% at ≥45 km. Foetal and neonatal mortality rates were highest for women living at maternity unit. For foetal mortality, rates increased at ≥45 km compared with 5-45 km. In adjusted models, long distance to a maternity unit had no impact on overall mortality but women living closer to a maternity unit had a higher risk of neonatal mortality. Neonatal deaths associated with out-of-hospital birth were rare but more frequent at longer distances. At the municipal-level, higher percentages of unemployment and foreign-born residents were associated with increased mortality. Overall mortality was not associated with living far from a maternity unit. Mortality was elevated in municipalities with social risk factors and located closest to a maternity unit, reflecting the location of maternity units in deprived areas with risk factors for poor outcome. © The Author 2014. Published by Oxford University Press on behalf of the European Public Health Association.

Factors that motivate and deter rehabilitation educators from participating in distance education.

Science.gov (United States)

Edwards, Yolanda V

2004-01-01

The major purpose of the study was to conduct exploratory research on the motivational levels of rehabilitation educators whose programs have Comprehensive Service Personnel Development (CSPD; Department of Education grant) grants targeted toward distance education. Additionally, the study attempted to identify whether significant factors existed that would inhibit faculty participation in distance education. There were three research questions to examine: (a) Do distance educators and non-distance educators differ significantly in intrinsic motivational factors? (b) Do distance educators and non-distance educators differ significantly in extrinsic motivational factors? and (c) Do distance educators and non-distance educators differ significantly in inhibiting factors? The results showed that rehabilitation faculty with CSPD grants who are distance educators are more extrinsically motivated (such as increase in salary, monetary support for participation, job security, working conditions, technical support, and requirement by department) than non-distance educators. There were no significant differences in levels between distance educators and non-distance educators that are intrinsically motivated (scholarly pursuit, personal research tool, and job satisfaction). There was no significant difference between distance educators and non-distance educators in inhibiting factors.

36 CFR 13.920 - Wildlife distance conditions.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Wildlife distance conditions... Provisions § 13.920 Wildlife distance conditions. (a) Bears. The following are prohibited: (1) Approaching within 300 yards of a bear; or (2) Engaging in photography within 300 yards of a bear. (b) Other wildlife...

Increasing Access and Relevance in Distance Education

Science.gov (United States)

Mendenhall, Robert W.

2009-01-01

Access to higher education is subject to many factors including affordability, time and geography. Distance education can deliver education to those that live far from a campus. Some of that distance education may be synchronous, or live, requiring students to be available at certain times. Flexibility and access are increased when the instruction…

Impact of Information and Communication Technology on Distance ...

African Journals Online (AJOL)

Impact of Information and Communication Technology on Distance Education: The case of National Open University of Nigeria. ... greater positive impacts on distance education enhancing academic success; that the National Open University ...

Psychological influences on distance estimation in a virtual reality environment.

Science.gov (United States)

Takahashi, Kohske; Meilinger, Tobias; Watanabe, Katsumi; Bülthoff, Heinrich H

2013-01-01

Studies of embodied perception have revealed that social, psychological, and physiological factors influence space perception. While many of these influences were observed with real or highly realistic stimuli, the present work showed that even the orientation of abstract geometric objects in a non-realistic virtual environment could influence distance perception. Observers wore a head mounted display and watched virtual cones moving within an invisible cube for 5 s with their head movement recorded. Subsequently, the observers estimated the distance to the cones or evaluated their friendliness. The cones either faced the observer, a target behind the cones, or were oriented randomly. The average viewing distance to the cones varied between 1.2 and 2.0 m. At a viewing distance of 1.6 m, the observers perceived the cones facing them as closer than the cones facing a target in the opposite direction, or those oriented randomly. Furthermore, irrespective of the viewing distance, observers moved their head away from the cones more strongly and evaluated the cones as less friendly when the cones faced the observers. Similar distance estimation results were obtained with a 3-dimensional projection onto a large screen, although the effective viewing distances were farther away. These results suggest that factors other than physical distance influenced distance perception even with non-realistic geometric objects in a virtual environment. Furthermore, the distance perception modulation was accompanied by changes in subjective impression and avoidance movement. We propose that cones facing an observer are perceived as socially discomforting or threatening, and potentially violate an observer's personal space, which might influence the perceived distance of cones.

The Bifixation Field as a Function of Viewing Distance

Directory of Open Access Journals (Sweden)

Philip M. Grove

2014-01-01

Full Text Available Hering reported that the area over which he could bifixate a target was smaller at near convergence distances than far convergence distances and predicted that in extreme horizontal gaze positions, the temporally directed eye lags behind the nasally directed eye. We tested these predictions using a subjective index of eye position. Experiment  1 confirmed that the bifixation field was significantly smaller at near convergence distances. When bifixation broke down at the near distance, the nasally directed eye lagged behind the temporally directed eye for all observers. At the far distance, the nasally directed eye preceded the temporally directed eye for four of six observers. Experiment  2 also confirmed that the bifixation field was smaller at near convergence distances but the nasally directed eye always lagged behind the temporally directed eye at the limits of the bifixation field. We confirmed Hering’s first prediction that the bifixation field is smaller at near convergence distances than at far ones. However, the majority of our results indicate that the nasally directed eye lags behind the temporally directed eye at the limits of the bifixation field, contrary to Hering’s prediction. We conclude that the eyes drift toward their tonic state of vergence when fusion breaks.

A Unimodal Model for Double Observer Distance Sampling Surveys.

Directory of Open Access Journals (Sweden)

Earl F Becker

Full Text Available Distance sampling is a widely used method to estimate animal population size. Most distance sampling models utilize a monotonically decreasing detection function such as a half-normal. Recent advances in distance sampling modeling allow for the incorporation of covariates into the distance model, and the elimination of the assumption of perfect detection at some fixed distance (usually the transect line with the use of double-observer models. The assumption of full observer independence in the double-observer model is problematic, but can be addressed by using the point independence assumption which assumes there is one distance, the apex of the detection function, where the 2 observers are assumed independent. Aerially collected distance sampling data can have a unimodal shape and have been successfully modeled with a gamma detection function. Covariates in gamma detection models cause the apex of detection to shift depending upon covariate levels, making this model incompatible with the point independence assumption when using double-observer data. This paper reports a unimodal detection model based on a two-piece normal distribution that allows covariates, has only one apex, and is consistent with the point independence assumption when double-observer data are utilized. An aerial line-transect survey of black bears in Alaska illustrate how this method can be applied.

Endurance and age : evidence from long-distance running data

NARCIS (Netherlands)

Sterken, Elmer

2001-01-01

This paper analyzes the impact of aging on long-run endurance. We analyze the determinants of running speed on distances from 5K to the marathon. We model running speed as a function of distance, age, and sex. We find evidence for interaction between age and sex, but not between distance and sex.

Application of Technology in Project-Based Distance Learning

Directory of Open Access Journals (Sweden)

Ali Mehrabian

2008-06-01

Full Text Available Present technology and the accessibility of internet have made distance learning easier, more efficient, and more convenient for students. This technology allows instructors and students to communicate asynchronously, at times and locations of their own choosing, by exchanging printed or electronic information. The use of project-based approach is being recognized in the literature as a potential component of courses in the faculties of engineering, science, and technology. Instructors may have to restructure their course differently to accommodate and facilitate the effectiveness of distance learning. A project-based engineering course, traditionally taught in a classroom settings using live mode at the College of Engineering and Computer Sciences at the University of Central Florida (UCF has been transformed to a distance course taught using distance modes. In this case, pedagogical transitions and adjustments are required, in particular for obtaining an optimal balance between the course material and the project work. Project collaboration in groups requires communication, which is possible with extensive utilization of new information and communication technology, such as virtual meetings. This paper discusses the course transition from live to distance modes and touches on some issues as they relate to the effectiveness of this methodology and the lessons learned from its application within different context. More specifically, this discussion includes the benefit of implementing project-based work in the domain of the distance learning courses.

Complex networks in the Euclidean space of communicability distances

Science.gov (United States)

Estrada, Ernesto

2012-06-01

We study the properties of complex networks embedded in a Euclidean space of communicability distances. The communicability distance between two nodes is defined as the difference between the weighted sum of walks self-returning to the nodes and the weighted sum of walks going from one node to the other. We give some indications that the communicability distance identifies the least crowded routes in networks where simultaneous submission of packages is taking place. We define an index Q based on communicability and shortest path distances, which allows reinterpreting the “small-world” phenomenon as the region of minimum Q in the Watts-Strogatz model. It also allows the classification and analysis of networks with different efficiency of spatial uses. Consequently, the communicability distance displays unique features for the analysis of complex networks in different scenarios.

Matrimonial distance, inbreeding coefficient and population size: Dhangar data.

Science.gov (United States)

Majumder, P P; Malhotra, K C

1979-01-01

Data on the distance between the birthplaces of spouses (matrimonial distance) were collected from 2,260 married individuals belonging to 21 endogamous castes of the Dhangar (shepherd) cast-cluster of Maharashtra, India. The general form of the distribution of matrimonial distances is one which is extremely positively skewed and leptokurtic. The percentage of intra-village marriages generally decreases from the southern areas of Maharashtra to the northern areas of the state, as does the inbreeding coefficient. This situation is in conformity with the socio-cultural norms regulating matrimonial choice in south and north India. An attempt has been made to relate the degree of inbreeding to the mean matrimonial distance and population size. The mean matrimonial distance is more useful in predicting the degree of inbreeding than population size.

Species turnover and geographic distance in an urban river network

DEFF Research Database (Denmark)

Rouquette, James R.; Dallimer, Martin; Armsworth, Paul R.

2013-01-01

AimUnderstanding the relationships between species turnover, environmental features and the geographic distance between sites can provide important insights into the processes driving species diversity. This is particularly relevant where the effective distance between sites may be a function...... patterns of species turnover and to determine whether these patterns differ between different taxonomic groups. LocationSheffield area, UK. MethodsAquatic (macroinvertebrates, diatoms) and terrestrial (birds, plants, butterflies) organisms were surveyed at 41 sites across an urban river network. We...... of the geographic distance measures, although network distance remained significant for birds and some plant groups after removing the effect of environmental distance. Water-dispersed and neophyte plant groups were significantly related to network and flow distance. Main conclusionsThe results suggest that aquatic...

Digital Competence Model of Distance Learning Students

Science.gov (United States)

da Silva, Ketia Kellen A.; Behar, Patricia A.

2017-01-01

This article presents the development of a digital competency model of Distance Learning (DL) students in Brazil called CompDigAl_EAD. The following topics were addressed in this study: Educational Competences, Digital Competences, and Distance Learning students. The model was developed between 2015 and 2016 and is being validated in 2017. It was…

VIRTUAL LEADERSHIP AT DISTANCE EDUCATION TEAMS

Directory of Open Access Journals (Sweden)

Meltem KUSCU

2016-07-01

Full Text Available Globalization being one of the most popular terms of recent years is considered as a factor changing the operation styles of the companies. Companies and universities opened up to the world with the globalization and as a result of it, they had the opportunity of being a world brand. Now, some companies have affiliated companies in almost every country. Well, if we think about time and place difference how do these companies lead the affiliated companies in various locations of the world? This question resulted in the new leadership approach, virtual leadership. The process of distance learning beginning with newspaper advertisement appears as virtual learning now. A number of companies and universities provide distance learning classes and in-service training in virtual platform via Internet. These trainings provided independently from time and space are conducted in a country and worldwide sometimes. If we consider individuals in different time and environments as virtual teams, dealing with these virtual teams is the duty of virtual leader. The purpose of this study is to examine virtual leadership perception of distance learning teams. Three trivets are in question for distance learning teams. The first one is the academicians lecturing the second one is the students and the third one is coordinator and technical support team. Perceptions of virtual leader of the said three groups were examined individually in this study.

Efficient Communication Protocols for Deciding Edit Distance

DEFF Research Database (Denmark)

Jowhari, Hossein

2012-01-01

In this paper we present two communication protocols on computing edit distance. In our first result, we give a one-way protocol for the following Document Exchange problem. Namely given x ∈ Σn to Alice and y ∈ Σn to Bob and integer k to both, Alice sends a message to Bob so that he learns x...... or truthfully reports that the edit distance between x and y is greater than k. For this problem, we give a randomized protocol in which Alice transmits at most O ˜ (klog 2 n) bits and each party’s time complexity is O ˜ (nlogn+k 2 log 2 n) . Our second result is a simultaneous protocol for edit distance over...... permutations. Here Alice and Bob both send a message to a third party (the referee) who does not have access to the input strings. Given the messages, the referee decides if the edit distance between x and y is at most k or not. For this problem we give a protocol in which Alice and Bob run a O...

Use of Distance Education in Dental Hygiene Programs.

Science.gov (United States)

Grimes, Ellen B.

2002-01-01

Surveyed dental hygiene programs to determine the prevalence of distance education use. Found that 22 percent have distance education, and that most were satisfied with it as an adequate alternative to traditional approaches. (EV)

Revival and robustness of Bures distance discord under decoherence channels

International Nuclear Information System (INIS)

Shi, Jia-dong; Wang, Dong; Ma, Yang-cheng; Ye, Liu

2016-01-01

In this paper, we demonstrate the revival and robustness of Bures distance discord in comparison with entanglement under local decoherent evolutions. The results show that in depolarizing channel Bures distance discord revives after a dark point of time, while entanglement will damp into death without revival. In addition, in hybrid channel the declining initial condition can enable Bures distance discord to decay more smoothly within a limited time, but speed up the death of entanglement. In this sense, Bures distance discord is typically more robust against decoherence than entanglement. Furthermore, we also provide a geometric interpretation concerning these phenomena. - Highlights: • Bures distance discord is more robust against decoherence than entanglement. • Bures distance discord revives after a dark point of time, while entanglement damps to death. • The initial condition enables Bures distance discord to damp smoothly, but it speeds up the death of entanglement. • A geometric interpretation concerning these phenomena has been provided.

Flying the Needles: Flight Deck Automation Erodes Fine-Motor Flying Skills Among Airline Pilots.

Science.gov (United States)

Haslbeck, Andreas; Hoermann, Hans-Juergen

2016-06-01

The aim of this study was to evaluate the influence of practice and training on fine-motor flying skills during a manual instrument landing system (ILS) approach. There is an ongoing debate that manual flying skills of long-haul crews suffer from a lack of flight practice due to conducting only a few flights per month and the intensive use of automation. However, objective evidence is rare. One hundred twenty-six randomly selected airline pilots had to perform a manual flight scenario with a raw data precision approach. Pilots were assigned to four equal groups according to their level of practice and training by fleet (short-haul, long-haul) and rank (first officer, captain). Average ILS deviation scores differed significantly in relation to the group assignments. The strongest predictor variable was fleet, indicating degraded performance among long-haul pilots. Manual flying skills are subject to erosion due to a lack of practice on long-haul fleets: All results support the conclusion that recent flight practice is a significantly stronger predictor for fine-motor flying performance than the time period since flight school or even the total or type-specific flight experience. Long-haul crews have to be supported in a timely manner by adequate training tailored to address manual skills or by operational provisions like mixed-fleet flying or more frequent transitions between short-haul and long-haul operation. © 2016, Human Factors and Ergonomics Society.

Perception of Egocentric Distance during Gravitational Changes in Parabolic Flight.

Directory of Open Access Journals (Sweden)

Gilles Clément

Full Text Available We explored the effect of gravity on the perceived representation of the absolute distance of objects to the observers within the range from 1.5-6 m. Experiments were performed on board the CNES Airbus Zero-G during parabolic flights eliciting repeated exposures to short periods of microgravity (0 g, hypergravity (1.8 g, and normal gravity (1 g. Two methods for obtaining estimates of perceived egocentric distance were used: verbal reports and visually directed motion toward a memorized visual target. For the latter method, because normal walking is not possible in 0 g, blindfolded subjects translated toward the visual target by pulling on a rope with their arms. The results showed that distance estimates using both verbal reports and blind pulling were significantly different between normal gravity, microgravity, and hypergravity. Compared to the 1 g measurements, the estimates of perceived distance using blind pulling were shorter for all distances in 1.8 g, whereas in 0 g they were longer for distances up to 4 m and shorter for distances beyond. These findings suggest that gravity plays a role in both the sensorimotor system and the perceptual/cognitive system for estimating egocentric distance.

Distance Learning: A Way of Life-Long Learning

National Research Council Canada - National Science Library

Belanich, James; Moses, Franklin L; Orvis, Kara L

2005-01-01

... the predominant form of distance learning today, and will likely continue to be in the future. The instructional approach of distance learning - or DL - has many benefits but has yet to reach its full potential...

Towards long-distance quantum communication: new techniques and tools

International Nuclear Information System (INIS)

Lukin, M.

2005-01-01

Full text: We will describe our efforts to develop new techniques and tools for long-distance quantum communication. Specifically we will discuss recent experimental work towards developing elements for long-distance quantum communication using atomic ensembles. In addition, we will describe a novel approach to long-distance quantum communication that is based on solid-state single photon emitters. (author)

The effect of debris-flow composition on runout distance

Science.gov (United States)

de Haas, Tjalling; Braat, Lisanne; Leuven, Jasper; Lokhorst, Ivar; Kleinhans, Maarten

2015-04-01

Estimating runout distance is of major importance for the assessment and mitigation of debris-flow hazards. Debris-flow runout distance depends on debris-flow composition and topography, but state-of-the-art runout prediction methods are mainly based on topographical parameters and debris-flow volume, while composition is generally neglected or incorporated in empirical constants. Here we experimentally investigated the effect of debris-flow composition and topography on runout distance. We created the first small-scale experimental debris flows with self-formed levees, distinct lobes and morphology and texture accurately resembling natural debris flows. In general, the effect of debris-flow composition on runout distance was larger than the effect of topography. Enhancing channel slope and width, outflow plain slope, debris-flow size and water fraction leads to an increase in runout distance. However, runout distance shows an optimum relation with coarse-material and clay fraction. An increase in coarse-material fraction leads to larger runout distances by increased grain collisional forces and more effective levee formation, but too much coarse debris causes a large accumulation of coarse debris at the flow front, enhancing friction and decreasing runout. An increase in clay fraction initially enlarges the volume and viscosity of the interstitial fluid, liquefying the flow and enhancing runout, while a further increase leads to very viscous flows with high yield strength, reducing runout. These results highlight the importance and further need of research on the relation between debris-flow composition and runout distance. Our experiments further provide valuable insight on the effects of debris-flow composition on depositional mechanisms and deposit morphology.

Distance to Cure

OpenAIRE

Capachi, Casey

2013-01-01

Distance to Cure A three-part television series by Casey Capachi www.distancetocure.com   Abstract   How far would you go for health care? This three-part television series, featuring two introductory segments between each piece, focuses on the physical, cultural, and political obstacles facing rural Native American patients and the potential of health technology to break down those barriers to care.   Part one,Telemedici...

Comparative evaluation of ultrasound scanner accuracy in distance measurement

Science.gov (United States)

Branca, F. P.; Sciuto, S. A.; Scorza, A.

2012-10-01

The aim of the present study is to develop and compare two different automatic methods for accuracy evaluation in ultrasound phantom measurements on B-mode images: both of them give as a result the relative error e between measured distances, performed by 14 brand new ultrasound medical scanners, and nominal distances, among nylon wires embedded in a reference test object. The first method is based on a least squares estimation, while the second one applies the mean value of the same distance evaluated at different locations in ultrasound image (same distance method). Results for both of them are proposed and explained.

Changes in Foot Shape after Long-Distance Running

OpenAIRE

Fukano, Mako; Iso, Shigeo

2015-01-01

Changes in foot shape during long-distance running may lead to alteration in shoe fit. However, little information is available on changes in foot shape following long-distance running. The purpose of this study was to assess changes in foot shape in experienced runners after a single long-distance run. Data from the right feet of 21 subjects were obtained using a foot scanner before and after running 35 km on an asphalt road. After the run, the dorsal height, navicular height, and arch heigh...

Online Communication in Organizations Does Not Kill Distance

DEFF Research Database (Denmark)

Hage, Eveline; Tan, Chee-Wee

Debates on the effects of online communication on distance within organizational networks have persisted within extant literature. Early contributions, which focus primarily on geographical distance, have highlighted the negative impact of distance on network evolution and sustenance, alluding...... to the importance of online communication as a means of nullifying these effects (Caimcross, 2001; Wellman, 2001). These studies have led to optimistic, but also premature, declarations of the ‘death of distance’ (Caimcross, 2001). More recent works however, have demonstrated that online networks are “to...

The social distance theory of power.

Science.gov (United States)

Magee, Joe C; Smith, Pamela K

2013-05-01

We propose that asymmetric dependence between individuals (i.e., power) produces asymmetric social distance, with high-power individuals feeling more distant than low-power individuals. From this insight, we articulate predictions about how power affects (a) social comparison, (b) susceptibility to influence, (c) mental state inference and responsiveness, and (d) emotions. We then explain how high-power individuals' greater experienced social distance leads them to engage in more abstract mental representation. This mediating process of construal level generates predictions about how power affects (a) goal selection and pursuit, (b) attention to desirability and feasibility concerns, (c) subjective certainty, (d) value-behavior correspondence, (e) self-control, and (f) person perception. We also reassess the approach/inhibition theory of power, noting limitations both in what it can predict and in the evidence directly supporting its proposed mechanisms. Finally, we discuss moderators and methodological recommendations for the study of power from a social distance perspective.

Exact geodesic distances in FLRW spacetimes

Science.gov (United States)

Cunningham, William J.; Rideout, David; Halverson, James; Krioukov, Dmitri

2017-11-01

Geodesics are used in a wide array of applications in cosmology and astrophysics. However, it is not a trivial task to efficiently calculate exact geodesic distances in an arbitrary spacetime. We show that in spatially flat (3 +1 )-dimensional Friedmann-Lemaître-Robertson-Walker (FLRW) spacetimes, it is possible to integrate the second-order geodesic differential equations, and derive a general method for finding both timelike and spacelike distances given initial-value or boundary-value constraints. In flat spacetimes with either dark energy or matter, whether dust, radiation, or a stiff fluid, we find an exact closed-form solution for geodesic distances. In spacetimes with a mixture of dark energy and matter, including spacetimes used to model our physical universe, there exists no closed-form solution, but we provide a fast numerical method to compute geodesics. A general method is also described for determining the geodesic connectedness of an FLRW manifold, provided only its scale factor.

Predictors of severe trunk postures among short-haul truck drivers during non-driving tasks: an exploratory investigation involving video-assessment and driver behavioural self-monitoring.

Science.gov (United States)

Olson, R; Hahn, D I; Buckert, A

2009-06-01

Short-haul truck (lorry) drivers are particularly vulnerable to back pain and injury due to exposure to whole body vibration, prolonged sitting and demanding material handling tasks. The current project reports the results of video-based assessments (711 stops) and driver behavioural self-monitoring (BSM) (385 stops) of injury hazards during non-driving work. Participants (n = 3) worked in a trailer fitted with a camera system during baseline and BSM phases. Descriptive analyses showed that challenging customer environments and non-standard ingress/egress were prevalent. Statistical modelling of video-assessment results showed that each instance of manual material handling increased the predicted mean for severe trunk postures by 7%, while customer use of a forklift, moving standard pallets and moving non-standard pallets decreased predicted means by 12%, 20% and 22% respectively. Video and BSM comparisons showed that drivers were accurate at self-monitoring frequent environmental conditions, but less accurate at monitoring trunk postures and rare work events. The current study identified four predictors of severe trunk postures that can be modified to reduce risk of injury among truck drivers and showed that workers can produce reliable self-assessment data with BSM methods for frequent and easily discriminated events environmental.

Quality evaluation in distance undergraduate courses in Brazil

Directory of Open Access Journals (Sweden)

Carla Netto

2015-01-01

of distance-run undergraduate courses (D.Ed.. The data from the instruments were then processed according to Discourse Textual Analysis (DTA. The evaluation process for undergraduate distance education courses in the USA was evaluated by identifying those quality indicators adopted by international accreditation agencies. Based on the analysis of the evaluation process of distance undergraduate courses in Brazil, a further study was carried out about the results and impacts of the Brazilian system, especially the indicators used and the level of confidence that existed when measuring the quality of distance-based undergraduate courses. As a result of this research, our researchers observed there was a real need to establish a quality assurance benchmark in Brazil along these conceptual lines, namely one that represents quality in D.Ed. and includes the usage of indicators that reflect the excellence of the degree course that are offered. This level of excellence is assessed on the basis of the training, experience, knowledge and skills of the evaluators, as well as on clear, precise and transparent criteria for measuring the quality-based distance degree courses. On the other hand, it is also necessary to be equipped with a Bank of Evaluators – not only for those who work in this field, but also for a group of experts that is large enough to implement the Brazilian evaluation system in distance education programs.

A Catalog of Distances to Molecular Clouds from Pan-STARRS1

Science.gov (United States)

Schlafly, Eddie; Green, G.; Finkbeiner, D. P.; Rix, H.

2014-01-01

We present a catalog of distances to molecular clouds, derived from PanSTARRS-1 photometry. We simultaneously infer the full probability distribution function of reddening and distance of the stars towards these clouds using the technique of Green et al. (2013) (see neighboring poster). We fit the resulting measurements using a simple dust screen model to infer the distance to each cloud. The result is a large, homogeneous catalog of distances to molecular clouds. For clouds with heliocentric distances greater than about 200 pc, typical statistical uncertainties in the distances are 5%, with systematic uncertainty stemming from the quality of our stellar models of about 10%. We have applied this analysis to many of the most well-studied clouds in the δ > -30° sky, including Orion, California, Taurus, Perseus, and Cepheus. We have also studied the entire catalog of Magnani, Blitz, and Mundy (1985; MBM), though for about half of those clouds we can provide only upper limits on the distances. We compare our distances with distances from the literature, when available, and find good agreement.

The anisotropy of perceived distance: The eyes story

Directory of Open Access Journals (Sweden)

Tošković Oliver

2011-01-01

Full Text Available The aim of this study is to determine whether the eye position shift changes perceived distance, that is, whether kinesthetic information from eye muscles affects distance perception. Two experiments were done, in a dark room (reduced-cue situation, with 27 participants, psychology undergraduates. Participants had a task to match distances of three stimuli, on three viewing directions, 0, 30 and 60 deg rees relative to the body. Head and body of participants were fixed, and they changed viewing directions only by moving their eyes. Stimuli were 7cm

Paintball velocity as a function of distance traveled

Directory of Open Access Journals (Sweden)

Pat Chiarawongse

2008-06-01

Full Text Available The relationship between the distance a paintball travels through air and its velocity is investigated by firing a paintball into a ballistic pendulum from a range of distances. The motion of the pendulum was filmed and analyzed by using video analysis software. The velocity of the paintball on impact was calculated from the maximum horizontal displacement of the pendulum. It is shown that the velocity of a paintball decreases exponentially with distance traveled, as expected. The average muzzle velocity of the paint balls is found with an estimate of the drag coefficient.

Paintball velocity as a function of distance traveled

Directory of Open Access Journals (Sweden)

Pat Chiarawongse

2008-06-01

Full Text Available The relationship between the distance a paintball travels through air and its velocity is investigated by firing a paintball into a ballistic pendulum from a range of distances. The motion of the pendulum was filmed and analyzed by using video analysis software. The velocity of the paintball on impact was calculated from the maximum horizontal displacement of the pendulum. It is shown that the velocity of a paintball decreases exponentially with distance traveled, as expected. The average muzzle velocity of the paint balls is found with an estimate of the drag coefficient

The interuncal distance in elderly patients with dementia

International Nuclear Information System (INIS)

Hanyu, Haruo; Takasaki, Masaru; Sugiyama, Takeshi; Abe, Shinei; Kobayashi, Yasutaka; Maehata, Yukihiko; Katsunuma, Hidetaka.

1993-01-01

The interuncal distance between the unci of the temporal lobes was measured from axial MR images of the brain in elderly patients with dementia including dementia of the Alzheimer type (DAT), vascular dementia (VD), and others. The measured value of the interuncal distance completely separated patients with DAT from normal controls, and there was significant diference in the interuncal distance between patients with DAT and VD. This measurement is a practical method of assessing hippocampal atrophy and appears to be a useful adjunct in the clinical diagnosis of DAT. (author)

Distance matrices and quadratic embedding of graphs

Directory of Open Access Journals (Sweden)

Nobuaki Obata

2018-04-01

Full Text Available A connected graph is said to be of QE class if it admits  a quadratic embedding in a Hilbert space, or equivalently, if the distance matrix is conditionally negative definite. Several criteria for a graph to be of QE class are derived from the point of view of graph operations. For a quantitative criterion the QE constant is introduced and concrete examples are shown with explicit calculation. If the distance matrix admits a constant row sum, the QE constant coincides with the second largest eigenvalue of the distance matrix. The QE constants are determined for all graphs on $n$ vertices with $n\\le5$, among which two are not of QE class.

Ethnic and social distance towards Roma population

Directory of Open Access Journals (Sweden)

Miladinović Slobodan

2008-01-01

Full Text Available The Roma people are one of social marginalised ethnic groups which can easily be classified as underclass or ethno-class. In this work are presented the results of survey data analysis of ethnic and social distance towards the Roma population (2007. It concludes that the Roma people are one of ethnic groups with the highest social and ethnic distances in all observed social relations. The conclusion is that their generations poverty and still of life which the poverty produces are main causes of the high distance. The society has very important task to overcome situation which keep their social situation. In this paper are showed some of possible solutions of solving global Romas social situation and their integration in the rest of society. .

Project-based Collaborative learning in distance education

DEFF Research Database (Denmark)

Knudsen, Morten; Bajard, Christine; Helbo, Jan

2004-01-01

) programme indicates, however, that adjustments are required in transforming the on-campus model to distance education. The main problem is that while project work is an excellent regulator of the learning process for on-campus students, this does not seem to be the case for off-campus students. Consequently......This article describes the experiences drawn from an experiment in transferring positive experience with a project-organised on-campus engineering programme to a technology supported distance education programme. Three years of experience with the Master of Industrial Information Technology (MII......, didactic adjustments have been made based on feedback, in particular from evaluation questionnaires. This process has been very constructive in approaching the goal: a successful model for project organized learning in distance education....

Physiological responses at short distances from a parametric speaker

Directory of Open Access Journals (Sweden)

Lee Soomin

2012-06-01

Full Text Available Abstract In recent years, parametric speakers have been used in various circumstances. In our previous studies, we verified that the physiological burden of the sound of parametric speaker set at 2.6 m from the subjects was lower than that of the general speaker. However, nothing has yet been demonstrated about the effects of the sound of a parametric speaker at the shorter distance between parametric speakers the human body. Therefore, we studied this effect on physiological functions and task performance. Nine male subjects participated in this study. They completed three consecutive sessions: a 20-minute quiet period as a baseline, a 30-minute mental task period with general speakers or parametric speakers, and a 20-minute recovery period. We measured electrocardiogram (ECG photoplethysmogram (PTG, electroencephalogram (EEG, systolic and diastolic blood pressure. Four experiments, one with a speaker condition (general speaker and parametric speaker, the other with a distance condition (0.3 m and 1.0 m, were conducted respectively at the same time of day on separate days. To examine the effects of the speaker and distance, three-way repeated measures ANOVA (speaker factor x distance factor x time factor were conducted. In conclusion, we found that the physiological responses were not significantly different between the speaker condition and the distance condition. Meanwhile, it was shown that the physiological burdens increased with progress in time independently of speaker condition and distance condition. In summary, the effects of the parametric speaker at the 2.6 m distance were not obtained at the distance of 1 m or less.

Prediction of protein conformational freedom from distance constraints

NARCIS (Netherlands)

de Groot, B.L.; van Aalten, D.M.F.; Scheek, R.M.; Amadei, A; Vriend, G.; Berendsen, H.J.C.

1997-01-01

A method is presented that generates random protein structures that fulfil a set of upper and lower interatomic distance limits, These limits depend on distances measured in experimental structures and the strength of the interatomic interaction, Structural differences between generated structures

Femtosecond frequency comb based distance measurement in air

NARCIS (Netherlands)

Balling, P.; Kren, P.; Masika, P.; van den Berg, S.A.

2009-01-01

Interferometric measurement of distance using a femtosecond frequency comb is demonstrated and compared with a counting interferometer displacement measurement. A numerical model of pulse propagation in air is developed and the results are compared with experimental data for short distances. The

Distance matrix-based approach to protein structure prediction.

Science.gov (United States)

Kloczkowski, Andrzej; Jernigan, Robert L; Wu, Zhijun; Song, Guang; Yang, Lei; Kolinski, Andrzej; Pokarowski, Piotr

2009-03-01

Much structural information is encoded in the internal distances; a distance matrix-based approach can be used to predict protein structure and dynamics, and for structural refinement. Our approach is based on the square distance matrix D = [r(ij)(2)] containing all square distances between residues in proteins. This distance matrix contains more information than the contact matrix C, that has elements of either 0 or 1 depending on whether the distance r (ij) is greater or less than a cutoff value r (cutoff). We have performed spectral decomposition of the distance matrices D = sigma lambda(k)V(k)V(kT), in terms of eigenvalues lambda kappa and the corresponding eigenvectors v kappa and found that it contains at most five nonzero terms. A dominant eigenvector is proportional to r (2)--the square distance of points from the center of mass, with the next three being the principal components of the system of points. By predicting r (2) from the sequence we can approximate a distance matrix of a protein with an expected RMSD value of about 7.3 A, and by combining it with the prediction of the first principal component we can improve this approximation to 4.0 A. We can also explain the role of hydrophobic interactions for the protein structure, because r is highly correlated with the hydrophobic profile of the sequence. Moreover, r is highly correlated with several sequence profiles which are useful in protein structure prediction, such as contact number, the residue-wise contact order (RWCO) or mean square fluctuations (i.e. crystallographic temperature factors). We have also shown that the next three components are related to spatial directionality of the secondary structure elements, and they may be also predicted from the sequence, improving overall structure prediction. We have also shown that the large number of available HIV-1 protease structures provides a remarkable sampling of conformations, which can be viewed as direct structural information about the

Distance Measurement Solves Astrophysical Mysteries

Science.gov (United States)

2003-08-01

Location, location, and location. The old real-estate adage about what's really important proved applicable to astrophysics as astronomers used the sharp radio "vision" of the National Science Foundation's Very Long Baseline Array (VLBA) to pinpoint the distance to a pulsar. Their accurate distance measurement then resolved a dispute over the pulsar's birthplace, allowed the astronomers to determine the size of its neutron star and possibly solve a mystery about cosmic rays. "Getting an accurate distance to this pulsar gave us a real bonanza," said Walter Brisken, of the National Radio Astronomy Observatory (NRAO) in Socorro, NM. Monogem Ring The Monogem Ring, in X-Ray Image by ROSAT satellite CREDIT: Max-Planck Institute, American Astronomical Society (Click on Image for Larger Version) The pulsar, called PSR B0656+14, is in the constellation Gemini, and appears to be near the center of a circular supernova remnant that straddles Gemini and its neighboring constellation, Monoceros, and is thus called the Monogem Ring. Since pulsars are superdense, spinning neutron stars left over when a massive star explodes as a supernova, it was logical to assume that the Monogem Ring, the shell of debris from a supernova explosion, was the remnant of the blast that created the pulsar. However, astronomers using indirect methods of determining the distance to the pulsar had concluded that it was nearly 2500 light-years from Earth. On the other hand, the supernova remnant was determined to be only about 1000 light-years from Earth. It seemed unlikely that the two were related, but instead appeared nearby in the sky purely by a chance juxtaposition. Brisken and his colleagues used the VLBA to make precise measurements of the sky position of PSR B0656+14 from 2000 to 2002. They were able to detect the slight offset in the object's apparent position when viewed from opposite sides of Earth's orbit around the Sun. This effect, called parallax, provides a direct measurement of

Defining functional distances over Gene Ontology

Directory of Open Access Journals (Sweden)

del Pozo Angela

2008-01-01

Full Text Available Abstract Background A fundamental problem when trying to define the functional relationships between proteins is the difficulty in quantifying functional similarities, even when well-structured ontologies exist regarding the activity of proteins (i.e. 'gene ontology' -GO-. However, functional metrics can overcome the problems in the comparing and evaluating functional assignments and predictions. As a reference of proximity, previous approaches to compare GO terms considered linkage in terms of ontology weighted by a probability distribution that balances the non-uniform 'richness' of different parts of the Direct Acyclic Graph. Here, we have followed a different approach to quantify functional similarities between GO terms. Results We propose a new method to derive 'functional distances' between GO terms that is based on the simultaneous occurrence of terms in the same set of Interpro entries, instead of relying on the structure of the GO. The coincidence of GO terms reveals natural biological links between the GO functions and defines a distance model Df which fulfils the properties of a Metric Space. The distances obtained in this way can be represented as a hierarchical 'Functional Tree'. Conclusion The method proposed provides a new definition of distance that enables the similarity between GO terms to be quantified. Additionally, the 'Functional Tree' defines groups with biological meaning enhancing its utility for protein function comparison and prediction. Finally, this approach could be for function-based protein searches in databases, and for analysing the gene clusters produced by DNA array experiments.

Understanding Long-distance Traveler Behavior : Supporting a Long-distance Passenger Travel Demand Model

Science.gov (United States)

2013-01-01

Long-distance trips in the United States can take 2 days or 2 weeks and may involve cars, buses, planes, or all three. Whether for business, to see family, or visit a national park, such a variety of trip characteristics requires a detailed understan...

Does distance e-learning work? A comparison between distance and face-to-face learners using e-learning materials

Directory of Open Access Journals (Sweden)

Sara de Freitas

2003-12-01

Full Text Available This study compares continual assessment data, intake numbers, retention numbers and final examination grades of a mixed cohort of face-to-face and distance learners against similar data from previous years where e-learning materials were not used in order to test whether e-learning materials can support the same quality and quantity of teaching and learning for both face-to-face and distance learners. The results for this cohort of learners demonstrate that: (i distance e-learners score as well and sometimes better than face-to-face learners; (ii face-to-face student numbers have increased; (iii overall, student retention and student attendance have been maintained; (iv final examination results have been maintained or in some cases improved; (v lecturer workload was high, but not unmanageable, and it is clear how manageability can be improved.

HABITAT USE OF AGE - 0 TWAITE SHAD (ALOSA FALLAX LACÉPÈDE, 1803 IN THE TIDAL FRESHWATER REGION OF THE ELBE RIVER, GERMANY.

Directory of Open Access Journals (Sweden)

GERKENS M.

2001-07-01

Full Text Available Between April and August 1997 the distribution of twaite shad larvae in the lower Elbe River downstream the city of Hamburg was examined by ring net, lift net and pop net sampling. During each haul six environmental parameters - water depth, water temperature, conductivity, oxygen concentration, distance from shore line and distance from river channel - were estimated. Twaite shad larvae were found from 26 May to 10 July. Yolk sac larvae were present from 26 May to 25 June. High abundances of twaite shad larvae were found in the side channels and main channels. A canonical correspondence analysis was calculated to evaluate the importance of measured environmental parameters for the distribution of age - 0 fishes. Water depth, distance from shore line and distance from river channel were identified as main parameters for the distribution of species. Twaite shad larvae preferred maximum water depth and distance from shore line and short distances to the river channel. An upstream displacement of the spawning grounds of twaite shad was observed, following a trend first noticed in the early 90th. Nowadays, the location of spawning grounds corresponds to the situation at the beginning of the 19th century. Reduced water pollution is believed to be the main reason for this phenomenon.

Giant HII regions as distance indicators

International Nuclear Information System (INIS)

Melnick, Jorge; Terlevich, Robert; Moles, Mariano

1987-01-01

The correlations between the integrated Hβ luminosities, the velocity widths of the nebular lines and the metallicities of giant HII regions and HII galaxies are demonstrated to provide powerful distance indicators. They are calibrated on a homogeneous sample of giant HII regions with well determined distances and applied to distant HII galaxies to obtain a value of H 0 =95+-10 for the Hubble parameter, consistent with the value obtained by the Tully-Fisher technique. The effect of Malmquist bias and other systematic effects on the HII region method are discussed in detail. (Author)

Contextual Distance Refining for Image Retrieval

KAUST Repository

Islam, Almasri

2014-01-01

Recently, a number of methods have been proposed to improve image retrieval accuracy by capturing context information. These methods try to compensate for the fact that a visually less similar image might be more relevant because it depicts the same object. We propose a new quick method for refining any pairwise distance metric, it works by iteratively discovering the object in the image from the most similar images, and then refine the distance metric accordingly. Test show that our technique improves over the state of art in terms of accuracy over the MPEG7 dataset.

Contextual Distance Refining for Image Retrieval

KAUST Repository

Islam, Almasri

2014-09-16

Recently, a number of methods have been proposed to improve image retrieval accuracy by capturing context information. These methods try to compensate for the fact that a visually less similar image might be more relevant because it depicts the same object. We propose a new quick method for refining any pairwise distance metric, it works by iteratively discovering the object in the image from the most similar images, and then refine the distance metric accordingly. Test show that our technique improves over the state of art in terms of accuracy over the MPEG7 dataset.

Generalized Distance Transforms and Skeletons in Graphics Hardware

NARCIS (Netherlands)

Strzodka, R.; Telea, A.

2004-01-01

We present a framework for computing generalized distance transforms and skeletons of two-dimensional objects using graphics hardware. Our method is based on the concept of footprint splatting. Combining different splats produces weighted distance transforms for different metrics, as well as the

Distance stereotest using a 3-dimensional monitor for adult subjects.

Science.gov (United States)

Kim, Jongshin; Yang, Hee Kyung; Kim, Youngmin; Lee, Byoungho; Hwang, Jeong-Min

2011-06-01

To evaluate the validity and test-retest reliability of a contour-based 3-dimensional (3-D) monitor distance stereotest (distance 3-D stereotest) and to measure the maximum horizontal disparity that can be fused with disparity vergence for determining the largest measurable disparity of true stereopsis. Observational case series. Sixty-four normal adult subjects (age range, 23 to 39 years) were recruited. Contour-based circles (crossed disparity, 5000 to 20 seconds of arc; Microsoft Visual Studio C(++) 6.0; Microsoft, Inc, Seattle, Washington, USA) were generated on a 3-D monitor (46-inch stereoscopic display) using polarization glasses and were presented to subjects with normal binocularity at 3 m. While the position of the stimulus changed among 4 possible locations, the subjects were instructed to press the corresponding position of the stimulus on a keypad. The results with the new distance 3-D stereotest were compared with those from the distance Randot stereotest. The results of the distance 3-D stereotest and the distance Randot stereotests were identical in 64% and within 1 disparity level in 97% of normal adults. Scores obtained with the 2 tests showed a statistically significant correlation (r = 0.324, P = .009). The half-width of the 95% limit of agreement was 0.47 log seconds of arc (1.55 octaves) using the distance 3-D stereotest--similar to or better than that obtained with conventional distance stereotests. The maximum binocular disparity that can be fused with vergence was 1828 ± 794 seconds of arc (range, 4000 to 500). The distance 3-D stereotest showed good concordance with the distance Randot stereotest and relatively good test-retest reliability, supporting the validity of the distance 3-D stereotest. The normative data set obtained from the present study can serve as a useful reference for quantitative assessment of a wide range of binocular sensory abnormalities. Copyright © 2011 Elsevier Inc. All rights reserved.

Weighted Distances in Scale-Free Configuration Models

Science.gov (United States)

Adriaans, Erwin; Komjáthy, Júlia

2018-01-01

In this paper we study first-passage percolation in the configuration model with empirical degree distribution that follows a power-law with exponent τ \\in (2,3) . We assign independent and identically distributed (i.i.d.) weights to the edges of the graph. We investigate the weighted distance (the length of the shortest weighted path) between two uniformly chosen vertices, called typical distances. When the underlying age-dependent branching process approximating the local neighborhoods of vertices is found to produce infinitely many individuals in finite time—called explosive branching process—Baroni, Hofstad and the second author showed in Baroni et al. (J Appl Probab 54(1):146-164, 2017) that typical distances converge in distribution to a bounded random variable. The order of magnitude of typical distances remained open for the τ \\in (2,3) case when the underlying branching process is not explosive. We close this gap by determining the first order of magnitude of typical distances in this regime for arbitrary, not necessary continuous edge-weight distributions that produce a non-explosive age-dependent branching process with infinite mean power-law offspring distributions. This sequence tends to infinity with the amount of vertices, and, by choosing an appropriate weight distribution, can be tuned to be any growing function that is O(log log n) , where n is the number of vertices in the graph. We show that the result remains valid for the the erased configuration model as well, where we delete loops and any second and further edges between two vertices.

Aplikácia distance workingu v konkrétnej firme

OpenAIRE

Hasík, Gabriel

2010-01-01

Bachelor thesis provides an overview of the various forms of distance working. It includes a theoretical part, where are described all types of distance working, then the section describing the effects of distance working on the employee and employer (the impact on the psychic, work efficiency, work ethic, etc.). The final part focuses on the application of distance working on a specific company. This section includes the assessment of various options and choices to suit the company.

Multi-image acquisition-based distance sensor using agile laser spot beam.

Science.gov (United States)

Riza, Nabeel A; Amin, M Junaid

2014-09-01

We present a novel laser-based distance measurement technique that uses multiple-image-based spatial processing to enable distance measurements. Compared with the first-generation distance sensor using spatial processing, the modified sensor is no longer hindered by the classic Rayleigh axial resolution limit for the propagating laser beam at its minimum beam waist location. The proposed high-resolution distance sensor design uses an electronically controlled variable focus lens (ECVFL) in combination with an optical imaging device, such as a charged-coupled device (CCD), to produce and capture different laser spot size images on a target with these beam spot sizes different from the minimal spot size possible at this target distance. By exploiting the unique relationship of the target located spot sizes with the varying ECVFL focal length for each target distance, the proposed distance sensor can compute the target distance with a distance measurement resolution better than the axial resolution via the Rayleigh resolution criterion. Using a 30 mW 633 nm He-Ne laser coupled with an electromagnetically actuated liquid ECVFL, along with a 20 cm focal length bias lens, and using five spot images captured per target position by a CCD-based Nikon camera, a proof-of-concept proposed distance sensor is successfully implemented in the laboratory over target ranges from 10 to 100 cm with a demonstrated sub-cm axial resolution, which is better than the axial Rayleigh resolution limit at these target distances. Applications for the proposed potentially cost-effective distance sensor are diverse and include industrial inspection and measurement and 3D object shape mapping and imaging.

The Euclidean distance degree

NARCIS (Netherlands)

Draisma, J.; Horobet, E.; Ottaviani, G.; Sturmfels, B.; Thomas, R.R.; Zhi, L.; Watt, M.

2014-01-01

The nearest point map of a real algebraic variety with respect to Euclidean distance is an algebraic function. For instance, for varieties of low rank matrices, the Eckart-Young Theorem states that this map is given by the singular value decomposition. This article develops a theory of such nearest

Academy Distance Learning Tools (IRIS) -

Data.gov (United States)

Department of Transportation — IRIS is a suite of front-end web applications utilizing a centralized back-end Oracle database. The system fully supports the FAA Academy's Distance Learning Program...

Preferred viewing distance and screen angle of electronic paper displays.

Science.gov (United States)

Shieh, Kong-King; Lee, Der-Song

2007-09-01

This study explored the viewing distance and screen angle for electronic paper (E-Paper) displays under various light sources, ambient illuminations, and character sizes. Data analysis showed that the mean viewing distance and screen angle were 495 mm and 123.7 degrees. The mean viewing distances for Kolin Chlorestic Liquid Crystal display was 500 mm, significantly longer than Sony electronic ink display, 491 mm. Screen angle for Kolin was 127.4 degrees, significantly greater than that of Sony, 120.0 degrees. Various light sources revealed no significant effect on viewing distances; nevertheless, they showed significant effect on screen angles. The screen angle for sunlight lamp (D65) was similar to that of fluorescent lamp (TL84), but greater than that of tungsten lamp (F). Ambient illumination and E-paper type had significant effects on viewing distance and screen angle. The higher the ambient illumination was, the longer the viewing distance and the lesser the screen angle. Character size had significant effect on viewing distances: the larger the character size, the longer the viewing distance. The results of this study indicated that the viewing distance for E-Paper was similar to that of visual display terminal (VDT) at around 500 mm, but greater than normal paper at about 360 mm. The mean screen angle was around 123.7 degrees, which in terms of viewing angle is 29.5 degrees below horizontal eye level. This result is similar to the general suggested viewing angle between 20 degrees and 50 degrees below the horizontal line of sight.

Maximum nondiffracting propagation distance of aperture-truncated Airy beams

Science.gov (United States)

Chu, Xingchun; Zhao, Shanghong; Fang, Yingwu

2018-05-01

Airy beams have called attention of many researchers due to their non-diffracting, self-healing and transverse accelerating properties. A key issue in research of Airy beams and its applications is how to evaluate their nondiffracting propagation distance. In this paper, the critical transverse extent of physically realizable Airy beams is analyzed under the local spatial frequency methodology. The maximum nondiffracting propagation distance of aperture-truncated Airy beams is formulated and analyzed based on their local spatial frequency. The validity of the formula is verified by comparing the maximum nondiffracting propagation distance of an aperture-truncated ideal Airy beam, aperture-truncated exponentially decaying Airy beam and exponentially decaying Airy beam. Results show that the formula can be used to evaluate accurately the maximum nondiffracting propagation distance of an aperture-truncated ideal Airy beam. Therefore, it can guide us to select appropriate parameters to generate Airy beams with long nondiffracting propagation distance that have potential application in the fields of laser weapons or optical communications.

Compressions of electrorheological fluids under different initial gap distances.

Science.gov (United States)

Tian, Yu; Wen, Shizhu; Meng, Yonggang

2003-05-01

Compressions of electrorheological (ER) fluids have been carried out under different initial gap distances and different applied voltages. The nominal yield stresses of the compressed ER fluid under different conditions, according to the mechanics of compressing continuous fluids considering the yield stress of the plastic fluid, have been calculated. Curves of nominal yield stress under different applied voltages at an initial gap distance of 4 mm overlapped well and were shown to be proportional to the square of the external electric field and agree well with the traditional description. With the decrease of the initial gap distance, the difference between the nominal yield stress curves increased. The gap distance effect on the compression of ER fluids could not be explained by the traditional description based on the Bingham model and the continuous media theory. An explanation based on the mechanics of particle chain is proposed to describe the gap distance effect on the compression of ER fluids.

Determining distances using asteroseismic methods

DEFF Research Database (Denmark)

Aguirre, Victor Silva; Casagrande, L.; Basu, Sarbina

2013-01-01

Asteroseismology has been extremely successful in determining the properties of stars in different evolutionary stages with a remarkable level of precision. However, to fully exploit its potential, robust methods for estimating stellar parameters are required and independent verification of the r......Asteroseismology has been extremely successful in determining the properties of stars in different evolutionary stages with a remarkable level of precision. However, to fully exploit its potential, robust methods for estimating stellar parameters are required and independent verification...... fluxes, and thus distances for field stars in a self-consistent manner. Applying our method to a sample of solar-like oscillators in the {\\it Kepler} field that have accurate {\\it Hipparcos} parallaxes, we find agreement in our distance determinations to better than 5%. Comparison with measurements...

Study of probe-sample distance for biomedical spectra measurement

Directory of Open Access Journals (Sweden)

Li Lei

2011-11-01

Full Text Available Abstract Background Fiber-based optical spectroscopy has been widely used for biomedical applications. However, the effect of probe-sample distance on the collection efficiency has not been well investigated. Method In this paper, we presented a theoretical model to maximize the illumination and collection efficiency in designing fiber optic probes for biomedical spectra measurement. This model was in general applicable to probes with single or multiple fibers at an arbitrary incident angle. In order to demonstrate the theory, a fluorescence spectrometer was used to measure the fluorescence of human finger skin at various probe-sample distances. The fluorescence spectrum and the total fluorescence intensity were recorded. Results The theoretical results show that for single fiber probes, contact measurement always provides the best results. While for multi-fiber probes, there is an optimal probe distance. When a 400- μm excitation fiber is used to deliver the light to the skin and another six 400- μm fibers surrounding the excitation fiber are used to collect the fluorescence signal, the experimental results show that human finger skin has very strong fluorescence between 475 nm and 700 nm under 450 nm excitation. The fluorescence intensity is heavily dependent on the probe-sample distance and there is an optimal probe distance. Conclusions We investigated a number of probe-sample configurations and found that contact measurement could be the primary choice for single-fiber probes, but was very inefficient for multi-fiber probes. There was an optimal probe-sample distance for multi-fiber probes. By carefully choosing the probe-sample distance, the collection efficiency could be enhanced by 5-10 times. Our experiments demonstrated that the experimental results of the probe-sample distance dependence of collection efficiency in multi-fiber probes were in general agreement with our theory.

Distance learning methodology and technique in scientific and vocational communication (on the example of the master’s distance course in linguistics

Directory of Open Access Journals (Sweden)

S. S. Khromov

2016-01-01

Full Text Available The article is devoted to the elaboration of methodology and technique of the master’s distance course in linguistics for Russian students. The research novelty lies in the fact that the course presents the results methodic and scientific work of the teachers’ and students’ stuff. Within the course framework we plan to transfer the communicative activity concept to the distance forms of education and modeling a new type of the educational product.The purposes of the research are: 1 to develop the distance learning methodology and technique for a linguistic master’s course; 2 to elaborate an internal structure of the project; 3 to demonstrate which vocational, language and speech competencies are to appear as tge result of the project; 4 to describe the algorithm of the full-time lecture course in linguistics in a distance format; 5 to conduct a pedagogical experiment realizing the distance learning education in master’s linguistic course; 6 to prove the innovation and the productivity of the elaborated master’s course in linguistics.The research is based on 1 the paper variant of the full-time lecture course 2 the curriculum of the lecture course 3 the concept of the master’s course in linguistics 4 the concept of the distance course in linguistics 5 students’ interviews 6 virtual tools The research methods are 1 descriptive 2 project 3 comparative 4 statistic methodsConclusion. The novelty and the productivity of the course have been proved and they are manifested in the following 1 in the ability to develop vocational, language and speech competences of the students 2 in developing individual trajectories of the students 3 in expanding sociocultural potential of the students 4 in developing sociocultural potential of the students 5 in intensifying education process. As a result of the experiment we can state that 1 the methodology and technique of distance tools in projecting master’s course in linguistics are described 2 the

Emotional distance to so-called difficult patients

DEFF Research Database (Denmark)

Michaelsen, Jette Joost

2012-01-01

Scand J Caring Sci; 2011 Emotional distance to so-called difficult patients Purpose: To explore nurses' relationships with patients they regard as being difficult. How do nurses feel about such patients and relate to them, and what are the consequences for nurse and patient? Design and methods....... Patients' case records were studied and four meetings with the staff were arranged to discuss the findings. Data collection lasted 18 months in all. Findings: Three strategies were identified: persuasion, avoidance (emotional distance), and compromise. Interestingly, in the relationship with a particular...... patient, the avoidance strategy did not necessarily represent the terminal stage, since a nurse could revert to the compromise strategy. Some of the nurses experienced painful emotions regarding these interactions. Conclusions: The avoidance strategy (emotional distance) resulted in important social...

A Survey of Binary Similarity and Distance Measures

Directory of Open Access Journals (Sweden)

Seung-Seok Choi

2010-02-01

Full Text Available The binary feature vector is one of the most common representations of patterns and measuring similarity and distance measures play a critical role in many problems such as clustering, classification, etc. Ever since Jaccard proposed a similarity measure to classify ecological species in 1901, numerous binary similarity and distance measures have been proposed in various fields. Applying appropriate measures results in more accurate data analysis. Notwithstanding, few comprehensive surveys on binary measures have been conducted. Hence we collected 76 binary similarity and distance measures used over the last century and reveal their correlations through the hierarchical clustering technique.

The Concept of Distance in International Management Research

DEFF Research Database (Denmark)

Ambos, Björn; Håkanson, Lars

2014-01-01

The effect of distance on firms' performance when entering, operating in and across foreign markets is a central issue in international management. However, our understanding of the impact of distance has long been constrained by flawed conceptualizations and unreliable measures. The papers...... in this issue break new ground both by advancing our theoretical understanding and by introducing new and potentially more useful measures. In this introduction, we provide a brief overview of the evolution of the distance concept before introducing the individual papers. We end by offering observations...... for future research based on the issues they raise....

Nanomechanical characterization by double-pass force-distance mapping

Energy Technology Data Exchange (ETDEWEB)

Dagdas, Yavuz S; Tekinay, Ayse B; Guler, Mustafa O; Dana, Aykutlu [UNAM Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara (Turkey); Necip Aslan, M, E-mail: aykutlu@unam.bilkent.edu.tr [Department of Physics, Istanbul Technical University, Istanbul (Turkey)

2011-07-22

We demonstrate high speed force-distance mapping using a double-pass scheme. The topography is measured in tapping mode in the first pass and this information is used in the second pass to move the tip over the sample. In the second pass, the cantilever dither signal is turned off and the sample is vibrated. Rapid (few kHz frequency) force-distance curves can be recorded with small peak interaction force, and can be processed into an image. Such a double-pass measurement eliminates the need for feedback during force-distance measurements. The method is demonstrated on self-assembled peptidic nanofibers.

Nanomechanical characterization by double-pass force-distance mapping

International Nuclear Information System (INIS)

Dagdas, Yavuz S; Tekinay, Ayse B; Guler, Mustafa O; Dana, Aykutlu; Necip Aslan, M

2011-01-01

We demonstrate high speed force-distance mapping using a double-pass scheme. The topography is measured in tapping mode in the first pass and this information is used in the second pass to move the tip over the sample. In the second pass, the cantilever dither signal is turned off and the sample is vibrated. Rapid (few kHz frequency) force-distance curves can be recorded with small peak interaction force, and can be processed into an image. Such a double-pass measurement eliminates the need for feedback during force-distance measurements. The method is demonstrated on self-assembled peptidic nanofibers.

Cutting the Distance in Distance Education: Reflections on the Use of E-Technologies in a New Zealand Social Work Program

Science.gov (United States)

Stanley-Clarke, Nicky; English, Awhina; Yeung, Polly

2018-01-01

The development of new e-technologies and an increased focus on developing distance social work education programs has created the impetus for social work educators to consider the tools they can employ in delivering distance courses. This article reflects on an action learning research project involving the development of an online toolbox of…

Special Issue on Distance Education and Development, Guest Editor Editorial -- Low Cost Distance Education Strategies: the use of appropriate information and communication technologies

Directory of Open Access Journals (Sweden)

Thomas Hülsmann

2004-04-01

Full Text Available The argument for distance education (including e-learning in developing countries could be imagined as a “triple jump.” Each leap of the triple jump consists of a theorem and a corollary applying it to developing countries.Theorem 1: Education is good for development. Corollary: The demand for education is especially high in the developing world. Traditional education cannot cope with its size and is, in many cases, not the most cost-effective allocation of resources.Theorem 2: Distance education can help. Corollary: Distance education is able to deal with large numbers more cost-effectively than traditional education, and has proved to do so also in developing countries.Theorem 3: E-learning is extending the capabilities of traditional distance education. Corollary: Given the emerging global information infrastructure, there are a number of cases where e-learning can enhance the capabilities of distance education in the developing world.Many distance educators would readily subscribe to theorems of leaps 1 and 2 of the triple jump, but argue that the argument collapses at leap 3, especially when it comes to the corollary suggesting that ICT-based distance education could be relevant in the developing world. This paper takes the role of the “devil’s advocate”1 , and will try to cast some doubt on the first two theorems, while intending to strengthen the third leap theorem, the least established argument of the three.

Three Dimensional Fast Exact Euclidean Distance (3D-FEED) Maps

NARCIS (Netherlands)

Latecki, L.J.; Schouten, Theo E.; Mount, D.M.; Kuppens, Harco C.; Wu, A.Y.; van den Broek, Egon

2006-01-01

In image and video analysis, distance maps are frequently used. They provide the (Euclidean) distance (ED) of background pixels to the nearest object pixel. Recently, the Fast Exact Euclidean Distance (FEED) transformation was launched. In this paper, we present the three dimensional (3D) version of

80537 based distance relay

DEFF Research Database (Denmark)

Pedersen, Knud Ole Helgesen

1999-01-01

A method for implementing a digital distance relay in the power system is described.Instructions are given on how to program this relay on a 80537 based microcomputer system.The problem is used as a practical case study in the course 53113: Micocomputer applications in the power system.The relay...

Factors influencing social distance toward people with mental illness.

Science.gov (United States)

Lauber, Christoph; Nordt, Carlos; Falcato, Luis; Rössler, Wulf

2004-06-01

When identifying ways to reduce stigmatization because of mental illness it is crucial to understand contributing factors. Social distance-the willingness to engage in relationships of varying intimacy with a person--is an indicator of public attitudes toward persons with mental illness. Multiple linear regression analysis of the results of a vignette-based opinion survey conducted on a representative population sample in Switzerland (n = 594). The level of social distance increases if situations imply 'social closeness.' The vignette describing a person with schizophrenia, attitudes to general aspects of mental health (lay helping, community psychiatry), emotions toward those affected, and the attitude toward consequences of mental illness (medical treatment, medication side effects, negative sanctions, e.g. withdrawal of the driver license) were found to predict social distance. Demographic factors such as age, gender, and the cultural background influence social distance. The explained variance (R2) is 44.8%. Social distance is a multifaceted concept influenced by, e.g., socio-economic and cultural factors, but also by the respondent's general attitude toward (mental) health issues. These results suggest that more knowledge about mental illnesses, especially schizophrenia, may increase social distance. The findings presented here may help to focus anti-stigma campaigns not only on transmission of knowledge, but on integrating different approaches.

Catharsis – Philosophical and Spiritual Aspects of Long-Distance Running

Directory of Open Access Journals (Sweden)

Nemec Marcel

2016-05-01

Full Text Available The purpose of the study was to identify and analyze the occurrence of cathartic states in a sample of long-distance runners. Data collected via questionnaires were used to evaluate quantitative variables complemented by heuristics while aiming at qualitatively categorize the areas of cathartic states in the context of philosophical and spiritual aspects of long-distance running. The study findings objectify philosophical and spiritual aspects affecting personalities of long-distance runners. The study findings have shown that catharsis represents a relevant philosophical and spiritual aspect affecting long-distance running. We assume that authentic experience of catharsis and its effects motivates runners to perform regular physical activity. The analysis of philosophical and spiritual aspects of long-distance running has revealed a multi-spectral holistic relevance based on the transfer affecting a specific way of life, spectrum of values, ethical personality traits, and also the quality of long-distance runners’ lives.

Distance measurement using frequency scanning interferometry with mode-hoped laser

Science.gov (United States)

Medhat, M.; Sobee, M.; Hussein, H. M.; Terra, O.

2016-06-01

In this paper, frequency scanning interferometry is implemented to measure distances up to 5 m absolutely. The setup consists of a Michelson interferometer, an external cavity tunable diode laser, and an ultra-low expansion (ULE) Fabry-Pérot (FP) cavity to measure the frequency scanning range. The distance is measured by acquiring simultaneously the interference fringes from, the Michelson and the FP interferometers, while scanning the laser frequency. An online fringe processing technique is developed to calculate the distance from the fringe ratio while removing the parts result from the laser mode-hops without significantly affecting the measurement accuracy. This fringe processing method enables accurate distance measurements up to 5 m with measurements repeatability ±3.9×10-6 L. An accurate translation stage is used to find the FP cavity free-spectral-range and therefore allow accurate measurement. Finally, the setup is applied for the short distance calibration of a laser distance meter (LDM).

Climate change leads to decreasing bird migration distances

NARCIS (Netherlands)

Visser, M.E.; Perdeck, A.C.; van Balen, J.H.; Both, C.

2009-01-01

Global climate change has led to warmer winters in NW Europe, shortening the distance between suitable overwintering areas and the breeding areas of many bird species. Here we show that winter recovery distances have decreased over the past seven decades, for birds ringed during the breeding season

Climate change leads to decreasing bird migration distances

NARCIS (Netherlands)

Visser, Marcel E.; Perdeck, Albert C.; van Balen, Johan H.; Both, Christiaan

Global climate change has led to warmer winters in NW Europe, shortening the distance between suitable overwintering areas and the breeding areas of many bird species. Here we show that winter recovery distances have decreased over the past seven decades, for birds ringed during the breeding season

Some remarks on the small-distance derivative model

International Nuclear Information System (INIS)

Jannussis, A.

1985-01-01

In the present work the new expressions of the derivatives for small distance are investigated according to Gonzales-Diaz model. This model is noncanonical, is a particular case of the Lie-admissible formulation and has applications for distance and time scales comparable with the Planck dimensions

The Carnegie-Chicago Hubble Program. I. An Independent Approach to the Extragalactic Distance Scale Using Only Population II Distance Indicators

Science.gov (United States)

Beaton, Rachael L.; Freedman, Wendy L.; Madore, Barry F.; Bono, Giuseppe; Carlson, Erika K.; Clementini, Gisella; Durbin, Meredith J.; Garofalo, Alessia; Hatt, Dylan; Jang, In Sung; Kollmeier, Juna A.; Lee, Myung Gyoon; Monson, Andrew J.; Rich, Jeffrey A.; Scowcroft, Victoria; Seibert, Mark; Sturch, Laura; Yang, Soung-Chul

2016-12-01

We present an overview of the Carnegie-Chicago Hubble Program, an ongoing program to obtain a 3% measurement of the Hubble constant (H 0) using alternative methods to the traditional Cepheid distance scale. We aim to establish a completely independent route to H 0 using RR Lyrae variables, the tip of the red giant branch (TRGB), and Type Ia supernovae (SNe Ia). This alternative distance ladder can be applied to galaxies of any Hubble type, of any inclination, and, using old stars in low-density environments, is robust to the degenerate effects of metallicity and interstellar extinction. Given the relatively small number of SNe Ia host galaxies with independently measured distances, these properties provide a great systematic advantage in the measurement of H 0 via the distance ladder. Initially, the accuracy of our value of H 0 will be set by the five Galactic RR Lyrae calibrators with Hubble Space Telescope Fine-Guidance Sensor parallaxes. With Gaia, both the RR Lyrae zero-point and TRGB method will be independently calibrated, the former with at least an order of magnitude more calibrators and the latter directly through parallax measurement of tip red giants. As the first end-to-end “distance ladder” completely independent of both Cepheid variables and the Large Magellanic Cloud, this path to H 0 will allow for the high-precision comparison at each rung of the traditional distance ladder that is necessary to understand tensions between this and other routes to H 0. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs #13472 and #13691.

Effect of Image Linearization on Normalized Compression Distance

Science.gov (United States)

Mortensen, Jonathan; Wu, Jia Jie; Furst, Jacob; Rogers, John; Raicu, Daniela

Normalized Information Distance, based on Kolmogorov complexity, is an emerging metric for image similarity. It is approximated by the Normalized Compression Distance (NCD) which generates the relative distance between two strings by using standard compression algorithms to compare linear strings of information. This relative distance quantifies the degree of similarity between the two objects. NCD has been shown to measure similarity effectively on information which is already a string: genomic string comparisons have created accurate phylogeny trees and NCD has also been used to classify music. Currently, to find a similarity measure using NCD for images, the images must first be linearized into a string, and then compared. To understand how linearization of a 2D image affects the similarity measure, we perform four types of linearization on a subset of the Corel image database and compare each for a variety of image transformations. Our experiment shows that different linearization techniques produce statistically significant differences in NCD for identical spatial transformations.

Collaborative distance learning: Developing an online learning community

Science.gov (United States)

Stoytcheva, Maria

2017-12-01

The method of collaborative distance learning has been applied for years in a number of distance learning courses, but they are relatively few in foreign language learning. The context of this research is a hybrid distance learning of French for specific purposes, delivered through the platform UNIV-RcT (Strasbourg University), which combines collaborative activities for the realization of a common problem-solving task online. The study focuses on a couple of aspects: on-line interactions carried out in small, tutored groups and the process of community building online. By analyzing the learner's perceptions of community and collaborative learning, we have tried to understand the process of building and maintenance of online learning community and to see to what extent the collaborative distance learning contribute to the development of the competence expectations at the end of the course. The analysis of the results allows us to distinguish the advantages and limitations of this type of e-learning and thus evaluate their pertinence.

Many-beam electron extinction distances in zirconium

International Nuclear Information System (INIS)

Cann, C.D.

1977-05-01

Many-beam extinction distances have been calculated for twenty-two of the lowest order reflections in zirconium. Ten beams comprising the directly transmitted and the nine lowest order systematic reflections were included in each calculation. Extinction distances for each reflection were determined for electron accelerating voltages of 100 and 200 kV, both at the exact Bragg condition and at deviations up to two Bragg angles from this condition. (author)

Student Identity and Authentication in Distance Education: A Primer for Distance Learning Administrators

Science.gov (United States)

Aceves, Patricia A.; Aceves, Robert I.

2009-01-01

Since the signing of the Higher Education Opportunity Act (HEOA) in August 2008, providers of distance education courses and programs have been looking into procedures and technologies that will satisfy the accrediting agencies responsible for enforcing the law. Continuing education administrators are at the forefront because of the pervasiveness…

Comparison of frequency-distance relationship and Gaussian-diffusion-based methods of compensation for distance-dependent spatial resolution in SPECT imaging

International Nuclear Information System (INIS)

Kohli, Vandana; King, Micgael A.; Glick, Stephen J.; Pan, Tin-Su

1998-01-01

The goal of this investigation was to compare resolution recovery versus noise level of two methods for compensation of distance-dependent resolution (DDR) in SPECT imaging. The two methods of compensation were restoration filtering based on the frequency-distance relationship (FDR) prior to iterative reconstruction, and modelling DDR in the projector/backprojector pair employed in iterative reconstruction. FDR restoration filtering was computationally faster than modelling the detector response in iterative reconstruction. Using Gaussian diffusion to model the detector response in iterative reconstruction sped up the process by a factor of 2.5 over frequency domain filtering in the projector/backprojector pair. Gaussian diffusion modelling resulted in a better resolution versus noise tradeoff than either FDR restoration filtering or solely modelling attenuation in the projector/backprojector pair of iterative reconstruction. For the pixel size investigated herein (0.317 cm), accounting for DDR in the projector/backprojector pair by Gaussian diffusion, or by applying a blurring function based on the distance from the face of the collimator at each distance, resulted in very similar resolution recovery and slice noise level. (author)

Opinion Mining in Online Reviews About Distance Education Programs

OpenAIRE

Jaskolski, Janik; Siegberg, Fabian; Tibroni, Thomas; Cimiano, Philipp; Klinger, Roman

2016-01-01

The popularity of distance education programs is increasing at a fast pace. En par with this development, online communication in fora, social media and reviewing platforms between students is increasing as well. Exploiting this information to support fellow students or institutions requires to extract the relevant opinions in order to automatically generate reports providing an overview of pros and cons of different distance education programs. We report on an experiment involving distance e...

Service Quality in Distance Education using the Gronroos Model

OpenAIRE

Hamid, Fazelina Sahul; Yip, Nick

2016-01-01

Demand for distance education programs have been increasing rapidly over the years. As a result, assessment of the quality of distance education programs has become a strategic issue that is very pertinent for program survival. This study uses Gronroos Model for assessing the service quality of the Malaysian distance education institutions. This model is chosen because it takes into account of the service delivery process and also service outcome. Our study confirms the multidimensional natur...

Average geodesic distance of skeleton networks of Sierpinski tetrahedron

Science.gov (United States)

Yang, Jinjin; Wang, Songjing; Xi, Lifeng; Ye, Yongchao

2018-04-01

The average distance is concerned in the research of complex networks and is related to Wiener sum which is a topological invariant in chemical graph theory. In this paper, we study the skeleton networks of the Sierpinski tetrahedron, an important self-similar fractal, and obtain their asymptotic formula for average distances. To provide the formula, we develop some technique named finite patterns of integral of geodesic distance on self-similar measure for the Sierpinski tetrahedron.