Successful Information and Communication Technology Implementation Strategies for Rural Communities: An Investigation of Tech-Based Economic Development Programs

ERIC Educational Resources Information Center

Sullivan, Donna Annette

2009-01-01

Many rural communities across America face several obstacles in the implementation of information and communication technologies (ICTs) initiatives and struggle with the best approaches for leveraging these elements into an economic development strategy. These obstacles include: lack of quality local ICTs infrastructure, funding, inability to…

The awareness and attitudes of students of one indian dental school toward information technology and its use to improve patient care.

PubMed

Jathanna, Vinod R; Jathanna, Ramya V; Jathanna, Roopalekha

2014-01-01

Many obstacles need to be overcome if digital and electronic technologies are to be fully integrated in the operation of dental clinics in some countries. These obstacles may be physical, technical, or psychosocial barriers in the form of perceptions and attitudes related to software incompatibilities, patient privacy, and interference with the patient-practitioner relationship. The objectives of the study are to assess the perceptions of Indian dental students of one school toward the usefulness of digital technologies in improving dental practice; their willingness to use digital and electronic technologies; the perceived obstacles to the use of digital and electronic technologies in dental care setups; and their attitudes toward Internet privacy issues. The study population consisted of 186 final year undergraduate dental students from the A. B. Shetty Memorial institute of Dental Sciences, Rajiv Gandhi University of Health Sciences, Mangalore, India. Survey data were analyzed descriptively . Most students indicated that information technology enhances patient satisfaction, the quality of dental record, diagnosis, treatment planning, and doctor-doctor communication. Cost of equipment and need for technical training were regarded as major obstacles by substantial proportions of respondents. Most dental students at our school feel that the information technology will support their decision making in diagnoses and devising effective treatment plans, which in turn increase patient satisfaction and quality of care. Students also perceived that lack of technical knowledge and the high cost of implementation are major barriers to developing information technology in India.

Wind turbines: current status, obstacles, trends and technologies

NASA Astrophysics Data System (ADS)

Konstantinidis, E. I.; Botsaris, P. N.

2016-11-01

The last decade the installation of wind farms around the world is spreading rapidly and wind energy has become a significant factor for promoting sustainable development. The scope of the present study is to indicate the present status of global wind power expansion as well as the current state of the art in the field of wind turbine technology. The RAM (reliability/availability/maintenance) section is also examined and the Levelized Cost of Energy for onshore/ offshore electricity production is presented. Negative consequences that go with the rapid expansion of wind power like accidents, environmental effects, etc. are highlighted. Especially visual impact to the landscape and noise pollution are some factors that provoke social reactions. Moreover, the complicated and long permitted process of a wind power plant, the high capital cost of the investment and the grid instability due to the intermittent nature of wind, are also significant obstacles in the development of the wind energy production. The current trends in the field of research and development of onshore and offshore wind power production are analyzed. Finally the present study is trying to achieve an estimation of where the wind industry targets for the years to come.

Big data and tactical analysis in elite soccer: future challenges and opportunities for sports science.

PubMed

Rein, Robert; Memmert, Daniel

2016-01-01

Until recently tactical analysis in elite soccer were based on observational data using variables which discard most contextual information. Analyses of team tactics require however detailed data from various sources including technical skill, individual physiological performance, and team formations among others to represent the complex processes underlying team tactical behavior. Accordingly, little is known about how these different factors influence team tactical behavior in elite soccer. In parts, this has also been due to the lack of available data. Increasingly however, detailed game logs obtained through next-generation tracking technologies in addition to physiological training data collected through novel miniature sensor technologies have become available for research. This leads however to the opposite problem where the shear amount of data becomes an obstacle in itself as methodological guidelines as well as theoretical modelling of tactical decision making in team sports is lacking. The present paper discusses how big data and modern machine learning technologies may help to address these issues and aid in developing a theoretical model for tactical decision making in team sports. As experience from medical applications show, significant organizational obstacles regarding data governance and access to technologies must be overcome first. The present work discusses these issues with respect to tactical analyses in elite soccer and propose a technological stack which aims to introduce big data technologies into elite soccer research. The proposed approach could also serve as a guideline for other sports science domains as increasing data size is becoming a wide-spread phenomenon.

Evaluation of Warm and Cold Shaft Designs for Large Multi-megawatt Direct Drive Offshore Superconducting Wind Generators

NASA Astrophysics Data System (ADS)

Kulkarni, Devdatta; Chen, Edward; Ho, Mantak; Karmaker, Haran

For offshore large multi-megawatt direct drive wind generators, because of its ability to generate high flux fields, superconducting (SC) technology can offer significant size and mass reduction over traditional technologies. However, cryogenic cooling design remains as one of the major obstacles to overcome. Different cryogenic cooling designs, such as warm shaft and cold shaft rotor design, present different advantages and challenges technically and commercially. This paper presents the investigations on both designs for large SC generators from manufacturability and service perspectives.

Perceptions of Blended Learning Competencies and Obstacles among Educational Technology Students in Light of Different Anxiety Levels and Locus of Control

ERIC Educational Resources Information Center

Aldalalah, Osamah Ahmad; Gasaymeh, Al-Mothana M.

2014-01-01

The purpose of this study was to investigate the effects of locus of control and anxiety level on the Jordanian educational technology students' perceived blended learning competencies and obstacles. The independent variables were the locus of control (Internal, External) and anxiety level (Low, Moderate, High). The dependent variables were the…

"Egg Races" and Other Practical Challenges

ERIC Educational Resources Information Center

Auty, Geoff

2013-01-01

This article presents ideas behind science and technology challenges and shares experiences of "egg races." Different challenges were set, but there was always the need to transport an egg across some obstacle course without breaking it. It was so popular in the 1980s that the term "egg race" came to mean any kind of simple…

Recovery of ammonia in raw and co-digested swine manure using gas-permeable membrane technology

USDA-ARS?s Scientific Manuscript database

Anaerobic digestion of agro-industrial and livestock waste generates considerable digestate volumes that are important sources of nitrogen (N). However, on some occasions, the high concentrations of N present in the digestates may represent an obstacle to its use locally as fertilizer, since it can ...

77 FR 42627 - Standard Instrument Approach Procedures, and Takeoff Minimums and Obstacle Departure Procedures...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-20

... CONTACT: Richard A. Dunham III, Flight Procedure Standards Branch (AFS-420), Flight Technologies and... 2012 Red Cloud, NE., Red Cloud Muni, Takeoff Minimums and Obstacle DP, Orig Effective 23 AUGUST 2012...

Novel approaches to helicopter obstacle warning

NASA Astrophysics Data System (ADS)

Seidel, Christian; Samuelis, Christian; Wegner, Matthias; Münsterer, Thomas; Rumpf, Thomas; Schwartz, Ingo

2006-05-01

EADS Germany is the world market leader in commercial Helicopter Laser Radar (HELLAS) Obstacle Warning Systems. The HELLAS-Warning System has been introduced into the market in 2000, is in service at German Border Control (Bundespolizei) and Royal Thai Airforce and is successfully evaluated by the Foreign Comparative Test Program (FCT) of the USSOCOM. Currently the successor system HELLAS-Awareness is in development. It will have extended sensor performance, enhanced realtime data processing capabilities and advanced HMI features. We will give an outline of the new sensor unit concerning detection technology and helicopter integration aspects. The system provides a widespread field of view with additional dynamic line of sight steering and a large detection range in combination with a high frame rate of 3Hz. The workflow of the data processing will be presented with focus on novel filter techniques and obstacle classification methods. As commonly known the former are indispensable due to unavoidable statistical measuring errors and solarisation. The amount of information in the filtered raw data is further reduced by ground segmentation. The remaining raised objects are extracted and classified in several stages into different obstacle classes. We will show the prioritization function which orders the obstacles concerning to their threat potential to the helicopter taking into account the actual flight dynamics. The priority of an object determines the display and provision of warnings to the pilot. Possible HMI representation includes video or FLIR overlay on multifunction displays, audio warnings and visualization of information on helmet mounted displays and digital maps. Different concepts will be presented.

Lessons Learned From Google Glass: Telemedical Spark or Unfulfilled Promise?

PubMed

Yu, Jonathan; Ferniany, William; Guthrie, Barton; Parekh, Selene G; Ponce, Brent

2016-04-01

Wearable devices such as Google Glass could potentially be used in the health care setting to expand access and improve quality of care. This study aims to assess the demographics of Google Glass users in health care and determine the obstacles to using Google Glass by surveying those who are known to use the device. A 48-question survey was designed to assess demographics of users, technological limitations of Google Glass, and obstacles to implementation of the device. The physicians surveyed worked in various fields of health care, with 50% of the respondents being surgeons. Potential participants were found using an Internet search for physicians using Google Glass in their practice. Outcome measures were divided into demographic information of users, technological limitations of the device, and administrative obstacles. A 43.6% response rate was observed. The majority of users were male, assistant professors, in academic hospitals, and in the United States. Numerous technological limitations were observed by the majority, including device ergonomics, display location, video quality, and audio quality. Patient confidentiality and data security were the major concerns among administrative obstacles. Despite the potential of Google Glass, numerous obstacles exist that limit its use in health care. While Google Glass has been discontinued, the results of this study may be used to guide future designs of wearable devices. © The Author(s) 2015.

Revitalizing Indigenous Languages. Papers presented at the Annual Stabilizing Indigenous Languages Symposium (5th, Louisville, KY, May 15-16, 1998).

ERIC Educational Resources Information Center

Reyhner, Jon, Ed.; Cantoni, Gina, Ed.; St. Clair, Robert N., Ed.; Yazzie, Evangeline Parsons, Ed.

This volume of conference papers examines issues and approaches in the revitalization of American Indian and other indigenous languages. Sections discuss obstacles and opportunities for language revitalization, language revitalization efforts and approaches, the role of writing in language revitalization, and using technology in language…

Opportunity is Knocking: Will Education Open the Door? Carnegie Perspectives

ERIC Educational Resources Information Center

Iiyoshi, Toru

2006-01-01

This essay presents a discussion of how the tools and resources of open source education may demonstrably improve education quality. The main tenet of open education is to make educational assets freely available to the public. This is becoming easier and less expensive as network and multimedia technology evolves. Obstacles may stand in the way…

Obstacles and opportunities in the commercialization of the solid state electronic fluorescent lighting ballast

NASA Astrophysics Data System (ADS)

Johnson, D. R.; Marcus, A. A.; Campbell, R. S.; Sommers, P.; Skumatz, L.; Berk, B.; Petty, P.; Eschbach, C.

1981-10-01

A solid state ballast (SSB), which improves the efficiency of fluorescent lights, is described. The first generation of solid state electronic ballasts was developed and the technology was transferred to the private sector. The opportunities for rapid dissemination of this technology into the marketplace is examined. Product characteristics and their influence on the commercialization of the SSB, a description of the technology delivery system presently used by the ballast industry, an analysis of the market for SSB, and identification of some high leverage opportunities to accelerate the commercialization process are included.

Neural correlates of obstacle negotiation in older adults: An fNIRS study.

PubMed

Chen, Michelle; Pillemer, Sarah; England, Sarah; Izzetoglu, Meltem; Mahoney, Jeannette R; Holtzer, Roee

2017-10-01

Older adults are less efficient at avoiding obstacles compared to young adults, especially under attention-demanding conditions. Using functional near-infrared-spectroscopy (fNIRS), recent studies implicated the prefrontal cortex (PFC) in cognitive control of locomotion, notably under dual-task walking conditions. The neural substrates underlying Obstacle Negotiation (ON), however, have not been established. The current study determined the role of the PFC in ON during walking in seniors. Non-demented older adults (n=90; mean age=78.1±5.5years; %female=51) underwent fNIRS acquisition to assess changes in hemodynamic activity in the PFC during normal-walk [NW] and walk-while-talk [WWT] conditions with and without obstacles. Obstacles were presented as red elliptical shapes using advanced laser technology, which resemble potholes. Linear mixed effects models were used to determine differences in oxygenated hemoglobin (HbO 2 ) levels among the four task conditions. The presence of slow gait, a risk factor for dementia and falls, served as a predictor hypothesized to moderate the effect of obstacles on PFC HbO 2 levels. PFC HbO 2 levels were significantly higher in WWT compared to NW (p<0.001) irrespective of ON. Slow gait moderated the effect of obstacles on HbO 2 levels across task conditions. Specifically, compared to participants with normal gait, PFC HbO 2 levels were significantly increased in ON-NW relative to NW (p=0.017) and ON-WWT relative to WWT (p<0.001) among individuals with slow gait. Consistent with Compensatory Reallocation, ON required greater PFC involvement among individuals with mobility limitations. Copyright © 2017 Elsevier B.V. All rights reserved.

Constructing target product profiles (TPPs) to help vaccines overcome post-approval obstacles

PubMed Central

Lee, Bruce Y.; Burke, Donald S.

2012-01-01

As history has demonstrated, post-approval obstacles can impede a vaccine’s use and potentially lead to its withdrawal. Addressing these potential obstacles when changes in a vaccine’s technology can still be easily made may improve a vaccine’s chances of success. Augmented vaccine target product profiles (TPPs) can help vaccine scientists better understand and anticipate these obstacles and galvanize conversations among various vaccine stakeholders (e.g., scientists, marketers, business development managers, policy makers, public health officials, health care workers, third party payors, etc.) earlier in a vaccine’s development. PMID:19782109

Robust mobility in human-populated environments

NASA Astrophysics Data System (ADS)

Gonzalez, Juan Pablo; Phillips, Mike; Neuman, Brad; Likhachev, Max

2012-06-01

Creating robots that can help humans in a variety of tasks requires robust mobility and the ability to safely navigate among moving obstacles. This paper presents an overview of recent research in the Robotics Collaborative Technology Alliance (RCTA) that addresses many of the core requirements for robust mobility in human-populated environments. Safe Interval Path Planning (SIPP) allows for very fast planning in dynamic environments when planning timeminimal trajectories. Generalized Safe Interval Path Planning extends this concept to trajectories that minimize arbitrary cost functions. Finally, generalized PPCP algorithm is used to generate plans that reason about the uncertainty in the predicted trajectories of moving obstacles and try to actively disambiguate the intentions of humans whenever necessary. We show how these approaches consider moving obstacles and temporal constraints and produce high-fidelity paths. Experiments in simulated environments show the performance of the algorithms under different controlled conditions, and experiments on physical mobile robots interacting with humans show how the algorithms perform under the uncertainties of the real world.

ICAT and the NASA technology transfer process

NASA Technical Reports Server (NTRS)

Rifkin, Noah; Tencate, Hans; Watkins, Alison

1993-01-01

This paper will address issues related to NASA's technology transfer process and will cite the example of using ICAT technologies in educational tools. The obstacles to effective technology transfer will be highlighted, viewing the difficulties in achieving successful transfers of ICAT technologies.

The ACT transport: Panacea for the 80's or designer's illusion (panel discussion)

NASA Technical Reports Server (NTRS)

1976-01-01

A panel discussion was held which attempted to make an objective and pragmatic assessment of the standing of active control technology. The discussion focused on the standing of active control technology relative to civil air transport applications, the value as opposed to the cost of the projected benefits, the need for research, development, and demonstration, the role of government and industry in developing the technology, the major obstacles to its implementation, and the probable timing of the full utilization of active control technology in commercial transportation. An edited transcription of the prepared statements of the panel members and the subsequent open discussion between the panel and the audience is presented.

Perspectives on micropole undulators in synchrotron radiation technology

NASA Astrophysics Data System (ADS)

Tatchyn, Roman; Csonka, Paul; Toor, Arthur

1989-07-01

Micropole undulators promise to advance synchrotron radiation (SR) technology in two distinct ways. The first is in the development of economical, low-energy storage rings, or linacs, as soft x-ray sources, and the second is in the opening up of gamma-ray spectral ranges on high-energy storage rings. In this paper the promise and current status of micropole undulator (MPU) technology are discussed, and a review of some practical obstacles to the implementation of MPU's on present-day storage rings is given. Some successful results of recent performance measurements of micropole undulators on the Lawrence Livermore National Laboratory linac are briefly summarized.

Long-range eye tracking: A feasibility study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jayaweera, S.K.; Lu, Shin-yee

1994-08-24

The design considerations for a long-range Purkinje effects based video tracking system using current technology is presented. Past work, current experiments, and future directions are thoroughly discussed, with an emphasis on digital signal processing techniques and obstacles. It has been determined that while a robust, efficient, long-range, and non-invasive eye tracking system will be difficult to develop, such as a project is indeed feasible.

Lack of Time as an Obstacle to Women's Education: The Case of Upper Volta.

ERIC Educational Resources Information Center

McSweeney, Brenda Gael; Freedman, Marion

1980-01-01

In Upper Volta, a major nonformal educational program attempted to overcome environment and time obstacles to educational participation by rural girls and women. This article discusses project findings on women's time use, the impact of various labor-saving technologies introduced, and women's participation in and attitudes toward project…

Obstacles Perceived by Physical Education Teachers to Integrating ICT

ERIC Educational Resources Information Center

Villalba, Ana; González-Rivera, María Dolores; Díaz-Pulido, Belén

2017-01-01

Teachers find difficulties and barriers about integrating technology in the physical education classroom. Therefore, the aim of this study is to analyse the perception of PE teachers regarding obstacles to integrating ICT and its relation with their age. The methodology followed was quantitative and descriptive in nature. The participants were 400…

Adoptive T cell therapy: An overview of obstacles and opportunities.

PubMed

Baruch, Erez Nissim; Berg, Amy Lauren; Besser, Michal Judith; Schachter, Jacob; Markel, Gal

2017-06-01

The therapeutic potential of adoptive cell therapy (ACT) in cancer patients was first acknowledged 3 decades ago, but it was an esoteric approach at the time. In recent years, technological advancements have transformed ACT into a viable therapeutic option that can be curative in some patients. In fact, current ACT response rates are 80% to 90% for hematological malignancies and 30% for metastatic melanoma refractory to multiple lines of therapy. Although these results are encouraging, there is still much to be done to fulfill ACT's potential, specifically with regard to improving clinical efficacy, expanding clinical indications, reducing toxicity, and increasing production and cost-effectiveness. This review addresses the current major obstacles to ACT and presents potential solutions. Cancer 2017;123:2154-62. © 2017 American Cancer Society. © 2017 American Cancer Society.

Obstacle Avoidance On Roadways Using Range Data

NASA Astrophysics Data System (ADS)

Dunlay, R. Terry; Morgenthaler, David G.

1987-02-01

This report describes range data based obstacle avoidance techniques developed for use on an autonomous road-following robot vehicle. The purpose of these techniques is to detect and locate obstacles present in a road environment for navigation of a robot vehicle equipped with an active laser-based range sensor. Techniques are presented for obstacle detection, obstacle location, and coordinate transformations needed in the construction of Scene Models (symbolic structures representing the 3-D obstacle boundaries used by the vehicle's Navigator for path planning). These techniques have been successfully tested on an outdoor robotic vehicle, the Autonomous Land Vehicle (ALV), at speeds up to 3.5 km/hour.

Assisting the visually impaired: obstacle detection and warning system by acoustic feedback.

PubMed

Rodríguez, Alberto; Yebes, J Javier; Alcantarilla, Pablo F; Bergasa, Luis M; Almazán, Javier; Cela, Andrés

2012-12-17

The aim of this article is focused on the design of an obstacle detection system for assisting visually impaired people. A dense disparity map is computed from the images of a stereo camera carried by the user. By using the dense disparity map, potential obstacles can be detected in 3D in indoor and outdoor scenarios. A ground plane estimation algorithm based on RANSAC plus filtering techniques allows the robust detection of the ground in every frame. A polar grid representation is proposed to account for the potential obstacles in the scene. The design is completed with acoustic feedback to assist visually impaired users while approaching obstacles. Beep sounds with different frequencies and repetitions inform the user about the presence of obstacles. Audio bone conducting technology is employed to play these sounds without interrupting the visually impaired user from hearing other important sounds from its local environment. A user study participated by four visually impaired volunteers supports the proposed system.

Assisting the Visually Impaired: Obstacle Detection and Warning System by Acoustic Feedback

PubMed Central

Rodríguez, Alberto; Yebes, J. Javier; Alcantarilla, Pablo F.; Bergasa, Luis M.; Almazán, Javier; Cela, Andrés

2012-01-01

The aim of this article is focused on the design of an obstacle detection system for assisting visually impaired people. A dense disparity map is computed from the images of a stereo camera carried by the user. By using the dense disparity map, potential obstacles can be detected in 3D in indoor and outdoor scenarios. A ground plane estimation algorithm based on RANSAC plus filtering techniques allows the robust detection of the ground in every frame. A polar grid representation is proposed to account for the potential obstacles in the scene. The design is completed with acoustic feedback to assist visually impaired users while approaching obstacles. Beep sounds with different frequencies and repetitions inform the user about the presence of obstacles. Audio bone conducting technology is employed to play these sounds without interrupting the visually impaired user from hearing other important sounds from its local environment. A user study participated by four visually impaired volunteers supports the proposed system. PMID:23247413

Health information technology in oncology practice: a literature review.

PubMed

Fasola, G; Macerelli, M; Follador, A; Rihawi, K; Aprile, G; Della Mea, V

2014-01-01

The adoption and implementation of information technology are dramatically remodeling healthcare services all over the world, resulting in an unstoppable and sometimes overwhelming process. After the introduction of the main elements of electronic health records and a description of what every cancer-care professional should be familiar with, we present a narrative review focusing on the current use of computerized clinical information and decision systems in oncology practice. Following a detailed analysis of the many coveted goals that oncologists have reached while embracing informatics progress, the authors suggest how to overcome the main obstacles for a complete physicians' engagement and for a full information technology adoption, and try to forecast what the future holds.

SLJ's 2011 Technology Survey: Things Are Changing. Fast

ERIC Educational Resources Information Center

Kenney, Brian

2011-01-01

Despite the funding challenges nearly all school libraries face, many media specialists are optimistic about the role of technology in the school library, according to "School Library Journal's" ("SLJ") 2011 Technology Survey. But in spite of the general optimism, others point to some significant obstacles: technological innovations are often…

Reading on Paper and Screen among Senior Adults: Cognitive Map and Technophobia

PubMed Central

Hou, Jinghui; Wu, Yijie; Harrell, Erin

2017-01-01

While the senior population has been increasingly engaged with reading on mobile technologies, research that specifically documents the impact of technologies on reading for this age group has still been lacking. The present study investigated how different reading media (screen versus paper) might result in different reading outcomes among older adults due to both cognitive and psychological factors. Using a laboratory experiment with 81participants aged 57 to 85, our results supported past research and showed the influence of cognitive map formation on readers’ feelings of fatigue. We contributed empirical evidence to the contention that reading on a screen could match that of reading from paper if the presentation of the text on screen resemble that of the print. Our findings also suggested that individual levels of technophobia was an important barrier to older adults’ effective use of mobile technologies for reading. In the post hoc analyses, we further showed that technophobia was correlated with technology experience, certain personality traits, and age. The present study highlights the importance of providing tailored support that helps older adults overcome psychological obstacles in using technologies. PMID:29312073

Technology Transfer: A Third World Perspective.

ERIC Educational Resources Information Center

Akubue, Anthony I.

2002-01-01

Technology transfer models are based on assumptions that do not reflect Third-World realities. Obstacles to building indigenous technology capacity include multinational corporations' control of innovations, strings attached to foreign aid, and indigenous reluctance to undertake research. Four areas of development include foreign direct…

Can Universities Develop Advanced Technology and Solve Social Problems?

NASA Astrophysics Data System (ADS)

Pérez Ones, Isarelis; Núñez Jover, Jorge

This paper presents case studies on how Cuban universities have increasingly become directly involved with the economic and social development of the country. The paper shows how Cuban universities, from the early 1980s and early 1990s, started reorientation and organization of their scientific research, becoming more directly and intensely involved in the economic and social development of the country. In this way, special reference is made to the case of a research group at the University of Havana: the Laboratory of Synthetic Antigens. This group developed the first synthetic vaccine for human use approved in the world. In the article, public policies involved in this success as well as different obstacles are discussed. These obstacles demonstrate the difficulties and challenges that universities face when carrying out research and innovation activities related to economic and social development.

A novel artificial immune algorithm for spatial clustering with obstacle constraint and its applications.

PubMed

Sun, Liping; Luo, Yonglong; Ding, Xintao; Zhang, Ji

2014-01-01

An important component of a spatial clustering algorithm is the distance measure between sample points in object space. In this paper, the traditional Euclidean distance measure is replaced with innovative obstacle distance measure for spatial clustering under obstacle constraints. Firstly, we present a path searching algorithm to approximate the obstacle distance between two points for dealing with obstacles and facilitators. Taking obstacle distance as similarity metric, we subsequently propose the artificial immune clustering with obstacle entity (AICOE) algorithm for clustering spatial point data in the presence of obstacles and facilitators. Finally, the paper presents a comparative analysis of AICOE algorithm and the classical clustering algorithms. Our clustering model based on artificial immune system is also applied to the case of public facility location problem in order to establish the practical applicability of our approach. By using the clone selection principle and updating the cluster centers based on the elite antibodies, the AICOE algorithm is able to achieve the global optimum and better clustering effect.

A Qualitative Study on the Obstacles Preventing the Successful Implementation of Web 2.0 in Corporate Learning

ERIC Educational Resources Information Center

Estrada, Luis

2012-01-01

The purpose of this study was to identify the obstacles to the adoption of Web 2.0 technologies as part of corporate learning solutions and strategies. The study followed a qualitative inquiry approach. The sample consisted of 20 corporate learning professionals who are members of the American Society for Training and Development (ASTD) social…

Advancing Teacher Technology Education Using Open-Ended Learning Environments as Research and Training Platforms

ERIC Educational Resources Information Center

Poitras, Eric; Doleck, Tenzin; Huang, Lingyun; Li, Shan; Lajoie, Susanne

2017-01-01

A primary concern of teacher technology education is for pre-service teachers to develop a sophisticated mental model of the affordances of technology that facilitates both teaching and learning with technology. One of the main obstacles to developing the requisite technological pedagogical content knowledge is the inherent challenge faced by…

A Needs Analysis for Technology Integration Plan: Challenges and Needs of Teachers

ERIC Educational Resources Information Center

Vatanartiran, Sinem; Karadeniz, Sirin

2015-01-01

Lack of technology leadership and technology integration plans are important obstacles for using technology effectively in schools. We carried out a large-scale study to be able to design a technology integration plan for one of the pilot provinces that Fatih Project was initiated. The purpose of this research is to examine the perceived…

TESTING, PERFORMANCE VALIDATION AND QUALITY ASSURANCE/QUALITY CONTROL OF FIELD-PORTABLE INSTRUMENTATION

EPA Science Inventory

New technologies for field-portable monitoring instruments often have a long lead time in development and authorization. Some obstacles to the acceptance of these pilot technologies include concern about liabilities, reluctance to take risks on new technologies, and uncertainty a...

New Technologies and Training in Metalworking.

ERIC Educational Resources Information Center

Belitsky, A. Harvey

This report reviews the role of technological factors in metalworking and the training required to adapt to new metalworking technologies. Focus is on whether firms that have adopted the new technologies have encountered obstacles in training and developing the skills of their work forces. The report is organized in three parts. Parts I and II…

The Obligation to Provide Assistive Technology: Enhancing the General Curriculum Access.

ERIC Educational Resources Information Center

Smith, Sean J.; Jones, Eric D.

1999-01-01

Describes public commitment (expressed in federal legislation) to using assistive technology devices and services in K-12 special education and discusses approaches for addressing obstacles in meeting this commitment. Reauthorization of the Individuals with Disabilities Act represents progress toward integrating assistive technology into disabled…

The Neglected Workforce.

ERIC Educational Resources Information Center

Fryer, Bronwyn

1999-01-01

Despite a 4 percent U.S. unemployment rate, Native American tribes suffer unemployment rates of around 50 percent. Meanwhile, information technology managers increasingly hire more foreign workers under H-1B visas. Obstacles to Native American participation in the information technology job market are a lack of technology infrastructure at tribal…

The "EyeCane", a new electronic travel aid for the blind: Technology, behavior & swift learning.

PubMed

Maidenbaum, Shachar; Hanassy, Shlomi; Abboud, Sami; Buchs, Galit; Chebat, Daniel-Robert; Levy-Tzedek, Shelly; Amedi, Amir

2014-01-01

Independent mobility is one of the most pressing problems facing people who are blind. We present the EyeCane, a new mobility aid aimed at increasing perception of environment beyond what is provided by the traditional White Cane for tasks such as distance estimation, navigation and obstacle detection. The "EyeCane" enhances the traditional White Cane by using tactile and auditory output to increase detectable distance and angles. It circumvents the technical pitfalls of other devices, such as weight, short battery life, complex interface schemes, and slow learning curve. It implements multiple beams to enables detection of obstacles at different heights, and narrow beams to provide active sensing that can potentially increase the user's spatial perception of the environment. Participants were tasked with using the EyeCane for several basic tasks with minimal training. Blind and blindfolded-sighted participants were able to use the EyeCane successfully for distance estimation, simple navigation and simple obstacle detection after only several minutes of training. These results demonstrate the EyeCane's potential for mobility rehabilitation. The short training time is especially important since available mobility training resources are limited, not always available, and can be quite expensive and/or entail long waiting periods.

Co-management of Water, Energy, and Food Systems: Where Are We and What Does it Take for Implementation?

NASA Astrophysics Data System (ADS)

Akhbari, M.

2015-12-01

Water, energy, and food are closely bound in consumption and production patterns. To increase resource efficiency and productivity in a sustainable fashion, co-management of water, energy, and food resources is becoming inevitable. These co-management schemes require implementation of nexus-based approaches, which takes the interconnections of water, energy, and food systems into account and considers that development in one area may have major effects on others. While society, economy and environment are the action areas to implement a nexus approach, finance, governance, infrastructure and technology can create solutions. Existing obstacles in the action areas and challenges associated with creating solutions increase the complexities to develop nexus-based approaches and complicate their implementation. This study, identifies existing social, economic, and environmental obstacles, financial demands and constraints, shortcomings in governance, and infrastructure problems in the United States as the main challenges that need to be overcome. Then, it will be discussed how advanced technology could be employed to facilitate implementation of nexus-based approaches, followed by providing some recommendations to enable institutions to employ new technology, overcome existing obstacles, and address challenges in order to implement nexus-based management approaches.

Traction-drive, seven-degree-of-freedom telerobot arm: A concept for manipulaton in space

NASA Technical Reports Server (NTRS)

Kuban, D. P.; Williams, D. M.

1987-01-01

As man seeks to expand his dominion into new environments, the demand increases for machines that perform useful functions in remote locations. This new concept for manipulation in space is based on knowledge and experience gained from manipulator systems developed to meet the needs of remote nuclear applications. It merges the best characteristics of teleoperation and robotic technologies. The design goals for the telerobot, a mechanical description, and technology areas that must be addressed for successful implementation are presented and discussed. The concept incorporates mechanical traction drives, redundant kinematics, and modular arm subelements to provide a backlash-free manipulator capable of obstacle avoidance.

Technical assistance and the transfer of remote sensing technology. [for economic development

NASA Technical Reports Server (NTRS)

Chipman, R.

1977-01-01

The transfer of technology from industrialized countries to the third world is a very complicated process and one that requires a great deal of research and development. The political and social obstacles to this transfer are generally greater than the technical obstacles, but technical assistance programs have neither the competence nor the inclination to deal with these factors adequately. Funding for technical assistance in remote sensing is now expanding rapidly, and there is a growing need for institutions to study and promote the effective use of this technology for economic development. The United Nations, the Food and Agriculture Organization, the World Bank, the United States Agency for International Development and the Canadian technical assistance agencies take different approaches to the problem and deal with the political pressures in different ways.

Obstacle avoidance and concealed target detection using the Army Research Lab ultra-wideband synchronous impulse reconstruction (UWB SIRE) forward imaging radar

NASA Astrophysics Data System (ADS)

Nguyen, Lam; Wong, David; Ressler, Marc; Koenig, Francois; Stanton, Brian; Smith, Gregory; Sichina, Jeffrey; Kappra, Karl

2007-04-01

The U.S. Army Research Laboratory (ARL), as part of a mission and customer funded exploratory program, has developed a new low-frequency, ultra-wideband (UWB) synthetic aperture radar (SAR) for forward imaging to support the Army's vision of an autonomous navigation system for robotic ground vehicles. These unmanned vehicles, equipped with an array of imaging sensors, will be tasked to help detect man-made obstacles such as concealed targets, enemy minefields, and booby traps, as well as other natural obstacles such as ditches, and bodies of water. The ability of UWB radar technology to help detect concealed objects has been documented in the past and could provide an important obstacle avoidance capability for autonomous navigation systems, which would improve the speed and maneuverability of these vehicles and consequently increase the survivability of the U. S. forces on the battlefield. One of the primary features of the radar is the ability to collect and process data at combat pace in an affordable, compact, and lightweight package. To achieve this, the radar is based on the synchronous impulse reconstruction (SIRE) technique where several relatively slow and inexpensive analog-to-digital (A/D) converters are used to sample the wide bandwidth of the radar signals. We conducted an experiment this winter at Aberdeen Proving Ground (APG) to support the phenomenological studies of the backscatter from positive and negative obstacles for autonomous robotic vehicle navigation, as well as the detection of concealed targets of interest to the Army. In this paper, we briefly describe the UWB SIRE radar and the test setup in the experiment. We will also describe the signal processing and the forward imaging techniques used in the experiment. Finally, we will present imagery of man-made obstacles such as barriers, concertina wires, and mines.

Strategic Planning to Enhance Teaching and Learning with Technology

ERIC Educational Resources Information Center

Delamarter, Steve

2006-01-01

Seminaries across North America are continuing to expand their use of technology for theological education. This article explores eight issues surrounding the strategic planning process when it comes to technology. These have to do with the obstacles to fresh thinking, the current best practices in strategic planning processes, detailed…

Web Tools: Keeping Learners on Pace

ERIC Educational Resources Information Center

Kosloski, Mickey

2016-01-01

One of the greatest challenges in teaching technology and engineering is pacing. Some students grasp new technological concepts quickly, while others need repetition and may struggle to keep pace. This poses an obstacle for the technology and engineering teacher, and is particularly true when teaching students to build a website. However, there…

Obstacle or Opportunity? Digital Thresholds in Professional Development

ERIC Educational Resources Information Center

McGowan, Susannah

2012-01-01

Using the Threshold Concepts Framework, I explore places where faculty frequently get stuck when attempting to adopt new technologies. They may be held back by preconceptions that technology is superfluous to traditional teaching methods or believe that they must understand the technology perfectly before introducing it into their teaching.…

Reexamining the Ethics of Nuclear Technology.

PubMed

Andrianov, Andrei; Kanke, Victor; Kuptsov, Ilya; Murogov, Viktor

2015-08-01

This article analyzes the present status, development trends, and problems in the ethics of nuclear technology in light of a possible revision of its conceptual foundations. First, to better recognize the current state of nuclear technology ethics and related problems, this article focuses on presenting a picture of the evolution of the concepts and recent achievements related to technoethics, based on the ethics of responsibility. The term 'ethics of nuclear technology' describes a multidisciplinary endeavor to examine the problems associated with nuclear technology through ethical frameworks and paradigms. Second, to identify the reasons for the intensification of efforts to develop ethics in relation to nuclear technology, this article presents an analysis of the recent situation and future prospects of nuclear technology deployment. This includes contradictions that have aggravated nuclear dilemmas and debates stimulated by the shortcomings of nuclear technology, as well as the need for the further development of a nuclear culture paradigm that is able to provide a conceptual framework to overcome nuclear challenges. Third, efforts in the field of nuclear technology ethics are presented as a short overview of particular examples, and the major findings regarding obstacles to the development of nuclear technology ethics are also summarized. Finally, a potential methodological course is proposed to overcome inaction in this field; the proposed course provides for the further development of nuclear technology ethics, assuming the axiological multidisciplinary problematization of the main concepts in nuclear engineering through the basic ethical paradigms: analytical, hermeneutical, and poststructuralist.

UAV Inspection of Electrical Transmission Infrastructure with Path Conformance Autonomy and Lidar-Based Geofences NASA Report on UTM Reference Mission Flights at Southern Company Flights November 2016

NASA Technical Reports Server (NTRS)

Moore, Andrew J.; Schubert, Matthew; Rymer, Nicholas; Balachandran, Swee; Consiglio, Maria; Munoz, Cesar; Smith, Joshua; Lewis, Dexter; Schneider, Paul

2017-01-01

Flights at low altitudes in close proximity to electrical transmission infrastructure present serious navigational challenges: GPS and radio communication quality is variable and yet tight position control is needed to measure defects while avoiding collisions with ground structures. To advance unmanned aerial vehicle (UAV) navigation technology while accomplishing a task with economic and societal benefit, a high voltage electrical infrastructure inspection reference mission was designed. An integrated air-ground platform was developed for this mission and tested in two days of experimental flights to determine whether navigational augmentation was needed to successfully conduct a controlled inspection experiment. The airborne component of the platform was a multirotor UAV built from commercial off-the-shelf hardware and software, and the ground component was a commercial laptop running open source software. A compact ultraviolet sensor mounted on the UAV can locate 'hot spots' (potential failure points in the electric grid), so long as the UAV flight path adequately samples the airspace near the power grid structures. To improve navigation, the platform was supplemented with two navigation technologies: lidar-to-polyhedron preflight processing for obstacle demarcation and inspection distance planning, and trajectory management software to enforce inspection standoff distance. Both navigation technologies were essential to obtaining useful results from the hot spot sensor in this obstacle-rich, low-altitude airspace. Because the electrical grid extends into crowded airspaces, the UAV position was tracked with NASA unmanned aerial system traffic management (UTM) technology. The following results were obtained: (1) Inspection of high-voltage electrical transmission infrastructure to locate 'hot spots' of ultraviolet emission requires navigation methods that are not broadly available and are not needed at higher altitude flights above ground structures. (2) The sensing capability of a novel airborne UV detector was verified with a standard ground-based instrument. Flights with this sensor showed that UAV measurement operations and recording methods are viable. With improved sensor range, UAVs equipped with compact UV sensors could serve as the detection elements in a self-diagnosing power grid. (3) Simplification of rich lidar maps to polyhedral obstacle maps reduces data volume by orders of magnitude, so that computation with the resultant maps in real time is possible. This enables real-time obstacle avoidance autonomy. Stable navigation may be feasible in the GPS-deprived environment near transmission lines by a UAV that senses ground structures and compares them to these simplified maps. (4) A new, formally verified path conformance software system that runs onboard a UAV was demonstrated in flight for the first time. It successfully maneuvered the aircraft after a sudden lateral perturbation that models a gust of wind, and processed lidar-derived polyhedral obstacle maps in real time. (5) Tracking of the UAV in the national airspace using the NASA UTM technology was a key safety component of this reference mission, since the flights were conducted beneath the landing approach to a heavily used runway. Comparison to autopilot tracking showed that UTM tracking accurately records the UAV position throughout the flight path.

FieldSAFE: Dataset for Obstacle Detection in Agriculture.

PubMed

Kragh, Mikkel Fly; Christiansen, Peter; Laursen, Morten Stigaard; Larsen, Morten; Steen, Kim Arild; Green, Ole; Karstoft, Henrik; Jørgensen, Rasmus Nyholm

2017-11-09

In this paper, we present a multi-modal dataset for obstacle detection in agriculture. The dataset comprises approximately 2 h of raw sensor data from a tractor-mounted sensor system in a grass mowing scenario in Denmark, October 2016. Sensing modalities include stereo camera, thermal camera, web camera, 360 ∘ camera, LiDAR and radar, while precise localization is available from fused IMU and GNSS. Both static and moving obstacles are present, including humans, mannequin dolls, rocks, barrels, buildings, vehicles and vegetation. All obstacles have ground truth object labels and geographic coordinates.

FieldSAFE: Dataset for Obstacle Detection in Agriculture

PubMed Central

Christiansen, Peter; Larsen, Morten; Steen, Kim Arild; Green, Ole; Karstoft, Henrik

2017-01-01

In this paper, we present a multi-modal dataset for obstacle detection in agriculture. The dataset comprises approximately 2 h of raw sensor data from a tractor-mounted sensor system in a grass mowing scenario in Denmark, October 2016. Sensing modalities include stereo camera, thermal camera, web camera, 360∘ camera, LiDAR and radar, while precise localization is available from fused IMU and GNSS. Both static and moving obstacles are present, including humans, mannequin dolls, rocks, barrels, buildings, vehicles and vegetation. All obstacles have ground truth object labels and geographic coordinates. PMID:29120383

A μ analysis-based, controller-synthesis framework for robust bioinspired visual navigation in less-structured environments.

PubMed

Keshavan, J; Gremillion, G; Escobar-Alvarez, H; Humbert, J S

2014-06-01

Safe, autonomous navigation by aerial microsystems in less-structured environments is a difficult challenge to overcome with current technology. This paper presents a novel visual-navigation approach that combines bioinspired wide-field processing of optic flow information with control-theoretic tools for synthesis of closed loop systems, resulting in robustness and performance guarantees. Structured singular value analysis is used to synthesize a dynamic controller that provides good tracking performance in uncertain environments without resorting to explicit pose estimation or extraction of a detailed environmental depth map. Experimental results with a quadrotor demonstrate the vehicle's robust obstacle-avoidance behaviour in a straight line corridor, an S-shaped corridor and a corridor with obstacles distributed in the vehicle's path. The computational efficiency and simplicity of the current approach offers a promising alternative to satisfying the payload, power and bandwidth constraints imposed by aerial microsystems.

AST Combustion Workshop: Diagnostics Working Group Report

NASA Technical Reports Server (NTRS)

Locke, Randy J.; Hicks, Yolanda R.; Hanson, Ronald K.

1996-01-01

A workshop was convened under NASA's Advanced Subsonics Technologies (AST) Program. Many of the principal combustion diagnosticians from industry, academia, and government laboratories were assembled in the Diagnostics/Testing Subsection of this workshop to discuss the requirements and obstacles to the successful implementation of advanced diagnostic techniques to the test environment of the proposed AST combustor. The participants, who represented the major relevant areas of advanced diagnostic methods currently applied to combustion and related fields, first established the anticipated AST combustor flowfield conditions. Critical flow parameters were then examined and prioritized as to their importance to combustor/fuel injector design and manufacture, environmental concerns, and computational interests. Diagnostic techniques were then evaluated in terms of current status, merits and obstacles for each flow parameter. All evaluations are presented in tabular form and recommendations are made on the best-suited diagnostic method to implement for each flow parameter in order of applicability and intrinsic value.

A novel anti-piracy optical disk with photochromic diarylethene

NASA Astrophysics Data System (ADS)

Liu, Guodong; Cao, Guoqiang; Huang, Zhen; Wang, Shenqian; Zou, Daowen

2005-09-01

Diarylethene is one of photochromic material with many advantages and one of the most promising recording materials for huge optical data storage. Diarylethene has two forms, which can be converted to each other by laser beams of different wavelength. The material has been researched for rewritable optical disks. Volatile data storage is one of its properties, which was always considered as an obstacle to utility. Many researches have been done for combating the obstacle for a long time. In fact, volatile data storage is very useful for anti-piracy optical data storage. Piracy is a social and economical problem. One technology of anti-piracy optical data storage is to limit readout of the data recorded in the material by encryption software. By the development of computer technologies, this kind of software is more and more easily cracked. Using photochromic diarylethene as the optical recording material, the signals of the data recorded in the material are degraded when it is read, and readout of the data is limited. Because the method uses hardware to realize anti-piracy, it is impossible cracked. In this paper, we will introduce this usage of the material. Some experiments are presented for proving its feasibility.

The use of neurocomputational models as alternatives to animal models in the development of electrical brain stimulation treatments.

PubMed

Beuter, Anne

2017-05-01

Recent publications call for more animal models to be used and more experiments to be performed, in order to better understand the mechanisms of neurodegenerative disorders, to improve human health, and to develop new brain stimulation treatments. In response to these calls, some limitations of the current animal models are examined by using Deep Brain Stimulation (DBS) in Parkinson's disease as an illustrative example. Without focusing on the arguments for or against animal experimentation, or on the history of DBS, the present paper argues that given recent technological and theoretical advances, the time has come to consider bioinspired computational modelling as a valid alternative to animal models, in order to design the next generation of human brain stimulation treatments. However, before computational neuroscience is fully integrated in the translational process and used as a substitute for animal models, several obstacles need to be overcome. These obstacles are examined in the context of institutional, financial, technological and behavioural lock-in. Recommendations include encouraging agreement to change long-term habitual practices, explaining what alternative models can achieve, considering economic stakes, simplifying administrative and regulatory constraints, and carefully examining possible conflicts of interest. 2017 FRAME.

Unpinning of spiral waves from rectangular obstacles by stimulated wave trains

NASA Astrophysics Data System (ADS)

Ponboonjaroenchai, Benjamas; Srithamma, Panatda; Kumchaiseemak, Nakorn; Sutthiopad, Malee; Müller, Stefan C.; Luengviriya, Chaiya; Luengviriya, Jiraporn

2017-09-01

Pinned spiral waves are exhibited in many excitable media. In cardiology, lengthened tachycardia correspond to propagating action potential in forms of spiral waves pinned to anatomical obstacles including veins and scares. Thus, elimination such waves is important particularly in medical treatments. We present study of unpinning of a spiral wave by a wave train initiated by periodic stimuli at a given location. The spiral wave is forced to leave the rectangular obstacle when the period of the wave train is shorter than a threshold Tunpin. For small obstacles, Tunpin decreases when the obstacle size is increased. Furthermore, Tunpin depends on the obstacle orientation with respect to the wave train propagation. For large obstacles, Tunpin is independent to the obstacle size. It implies that the orientation of the obstacle plays an important role in the unpinning of the spiral wave, especially for small rectangular obstacles.

Obstacle avoidance handling and mixed integer predictive control for space robots

NASA Astrophysics Data System (ADS)

Zong, Lijun; Luo, Jianjun; Wang, Mingming; Yuan, Jianping

2018-04-01

This paper presents a novel obstacle avoidance constraint and a mixed integer predictive control (MIPC) method for space robots avoiding obstacles and satisfying physical limits during performing tasks. Firstly, a novel kind of obstacle avoidance constraint of space robots, which needs the assumption that the manipulator links and the obstacles can be represented by convex bodies, is proposed by limiting the relative velocity between two closest points which are on the manipulator and the obstacle, respectively. Furthermore, the logical variables are introduced into the obstacle avoidance constraint, which have realized the constraint form is automatically changed to satisfy different obstacle avoidance requirements in different distance intervals between the space robot and the obstacle. Afterwards, the obstacle avoidance constraint and other system physical limits, such as joint angle ranges, the amplitude boundaries of joint velocities and joint torques, are described as inequality constraints of a quadratic programming (QP) problem by using the model predictive control (MPC) method. To guarantee the feasibility of the obtained multi-constraint QP problem, the constraints are treated as soft constraints and assigned levels of priority based on the propositional logic theory, which can realize that the constraints with lower priorities are always firstly violated to recover the feasibility of the QP problem. Since the logical variables have been introduced, the optimization problem including obstacle avoidance and system physical limits as prioritized inequality constraints is termed as MIPC method of space robots, and its computational complexity as well as possible strategies for reducing calculation amount are analyzed. Simulations of the space robot unfolding its manipulator and tracking the end-effector's desired trajectories with the existence of obstacles and physical limits are presented to demonstrate the effectiveness of the proposed obstacle avoidance strategy and MIPC control method of space robots.

Laser development for optimal helicopter obstacle warning system LADAR performance

NASA Astrophysics Data System (ADS)

Yaniv, A.; Krupkin, V.; Abitbol, A.; Stern, J.; Lurie, E.; German, A.; Solomonovich, S.; Lubashitz, B.; Harel, Y.; Engart, S.; Shimoni, Y.; Hezy, S.; Biltz, S.; Kaminetsky, E.; Goldberg, A.; Chocron, J.; Zuntz, N.; Zajdman, A.

2005-04-01

Low lying obstacles present immediate danger to both military and civilian helicopters performing low-altitude flight missions. A LADAR obstacle detection system is the natural solution for enhancing helicopter safety and improving the pilot situation awareness. Elop is currently developing an advanced Surveillance and Warning Obstacle Ranging and Display (SWORD) system for the Israeli Air Force. Several key factors and new concepts have contributed to system optimization. These include an adaptive FOV, data memorization, autonomous obstacle detection and warning algorithms and the use of an agile laser transmitter. In the present work we describe the laser design and performance and discuss some of the experimental results. Our eye-safe laser is characterized by its pulse energy, repetition rate and pulse length agility. By dynamically controlling these parameters, we are able to locally optimize the system"s obstacle detection range and scan density in accordance with the helicopter instantaneous maneuver.

Innovation in Library Education: Historical X-Files on Technology, People, and Change.

ERIC Educational Resources Information Center

Carmichael, James V., Jr.

1998-01-01

Discusses the history of library education and library educators. Highlights include Melvil Dewey's proposal for formal library education, the earlier apprentice system, obstacles to formal education, changes in attitudes toward patrons, accreditation, standards, and technological changes. (LRW)

Minimum Conflict Mainstreaming.

ERIC Educational Resources Information Center

Awen, Ed; And Others

Computer technology is discussed as a tool for facilitating the implementation of the mainstreaming process. Minimum conflict mainstreaming/merging (MCM) is defined as an approach which utilizes computer technology to circumvent such structural obstacles to mainstreaming as transportation scheduling, screening and assignment of students, testing,…

Technology as an Instrument to Improve Quality, Accountability, and Reflection in Academic Medicine

ERIC Educational Resources Information Center

Wilkes, Michael S.; Howell, Lydia

2006-01-01

Objective: This article describes two complementary technology systems used in academic medicine to 1) improve the quality of learning and teaching, and 2) describe the barriers and obstacles encountered in implementing these systems. Method: The literature was integrated with in-depth, case-based experience with technology related to student…

The Role of School Administrators in the Use of Technology

ERIC Educational Resources Information Center

Öznacar, Behcet; Dericioglu, Sonay

2017-01-01

This research is conducted to obtain the thoughts of state high school administrators to determine the obstacles that they are exposed to while using technology and attempting to integrate technology into their schools. The research is carried out through using the qualitative research design "phenomenology." The sample group of this…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, J.; Ahn, Y.; Tilka, J. A.

Disorder in the potential-energy landscape presents a major obstacle to the more rapid development of semiconductor quantum device technologies. We report a large-magnitude source of disorder, beyond commonly considered unintentional background doping or fixed charge in oxide layers: nanoscale strain fields induced by residual stresses in nanopatterned metal gates. Quantitative analysis of synchrotron coherent hard x-ray nanobeam diffraction patterns reveals gate-induced curvature and strains up to 0.03% in a buried Si quantum well within a Si/SiGe heterostructure. Furthermore, electrode stress presents both challenges to the design of devices and opportunities associated with the lateral manipulation of electronic energy levels.

Zinc finger nuclease technology: advances and obstacles in modelling and treating genetic disorders.

PubMed

Jabalameli, Hamid Reza; Zahednasab, Hamid; Karimi-Moghaddam, Amin; Jabalameli, Mohammad Reza

2015-03-01

Zinc finger nucleases (ZFNs) are engineered restriction enzymes designed to target specific DNA sequences within the genome. Assembly of zinc finger DNA-binding domain to a DNA-cleavage domain enables the enzyme machinery to target unique locus in the genome and invoke endogenous DNA repair mechanisms. This machinery offers a versatile approach in allele editing and gene therapy. Here we discuss the architecture of ZFNs and strategies for generating targeted modifications within the genome. We review advances in gene therapy and modelling of the disease using these enzymes and finally, discuss the practical obstacles in using this technology. Copyright © 2014 Elsevier B.V. All rights reserved.

Fundamental Challenges for Modeling Electrochemical Energy Storage Systems at the Atomic Scale.

PubMed

Groß, Axel

2018-04-23

There is a strong need to improve the efficiency of electrochemical energy storage, but progress is hampered by significant technological and scientific challenges. This review describes the potential contribution of atomic-scale modeling to the development of more efficient batteries, with a particular focus on first-principles electronic structure calculations. Numerical and theoretical obstacles are discussed, along with ways to overcome them, and some recent examples are presented illustrating the insights into electrochemical energy storage that can be gained from quantum chemical studies.

Obstacles and Supports Related to the Use of Educational Technologies: The Role of Technological Expertise, Gender, and Age

ERIC Educational Resources Information Center

Lane, Cara A.; Lyle, Henry F.

2011-01-01

In order for institutions of higher education to provide essential technology resources and encourage the adoption of educational technologies, it is vital to gather information about the barriers their users encounter and the supports they find most helpful. The purpose of this study is to better understand how differences in user traits (e.g.,…

Rebuilding Haiti's Educational Access: A Phenomenological Study of Technology Use in Education Delivery

ERIC Educational Resources Information Center

Sandiford, Gladwyn A.

2013-01-01

There is a lack of access to technology blended with face-to-face instruction and learning in Haiti. Despite this lack of access, some Haitian college students have nevertheless leveraged technology to overcome the obstacles of poverty and obtain a higher education. This phenomenological study explored the lived experiences of 20 adult…

Decision Theory and the Governance of Technology.

ERIC Educational Resources Information Center

Woodhouse, Edward J.

1987-01-01

Provides an overview of the decision making process for science and technology. Finds that government agencies and officials are not the major decision makers. Examines obstacles to achieving intelligent decisions when policy makers are scientists, business executives, and consumers. Concludes with five strategies for improving technological…

Constrained navigation for unmanned systems

NASA Astrophysics Data System (ADS)

Vasseur, Laurent; Gosset, Philippe; Carpentier, Luc; Marion, Vincent; Morillon, Joel G.; Ropars, Patrice

2005-05-01

The French Military Robotic Study Program (introduced in Aerosense 2003), sponsored by the French Defense Procurement Agency and managed by Thales as the prime contractor, focuses on about 15 robotic themes which can provide an immediate "operational add-on value". The paper details the "constrained navigation" study (named TEL2), which main goal is to identify and test a well-balanced task sharing between man and machine to accomplish a robotic task that cannot be performed autonomously at the moment because of technological limitations. The chosen function is "obstacle avoidance" on rough ground and quite high speed (40 km/h). State of the art algorithms have been implemented to perform autonomous obstacle avoidance and following of forest borders, using scanner laser sensor and standard localization functions. Such an "obstacle avoidance" function works well most of the time, BUT fails sometimes. The study analyzed how the remote operator can manage such failures so that the system remains fully operationally reliable; he can act according to two ways: a) finely adjust the vehicle current heading; b) take the control of the vehicle "on the fly" (without stopping) and bring it back to autonomous behavior when motion is secured again. The paper also presents the results got from the military acceptance tests performed on French 4x4 DARDS ATD.

Zero Gravity Aircraft Testing of a Prototype Portable Fire Extinguisher for Use in Spacecraft

NASA Astrophysics Data System (ADS)

Butz, J.; Carriere, T.; Abbud-Madrid, A.; Easton, J.

2012-01-01

For the past five years ADA Technologies has been developing a portable fire extinguisher (PFE) for use in microgravity environments. This technology uses fine water mist (FWM) to effectively and efficiently extinguish fires representative of spacecraft hazards. Recently the FWM PFE was flown on a Zero-G (reduced gravity) aircraft to validate the performance of the technology in a microgravity environment. Test results demonstrated that droplet size distributions generated in the reduced gravity environment were in the same size range as data collected during normal gravity (1-g) discharges from the prototype PFE. Data taken in an obscured test configuration showed that the mist behind the obstacle was more dense in the low-g environment when compared to 1-g discharges. The mist behind the obstacle tended to smaller droplet sizes in both the low-g and 1-g test conditions.

Students Race Rovers on a Martian and Lunar-themed Obstacle Course

NASA Image and Video Library

2017-01-05

NASA's Human Exploration Rover Challenge encourages STEM-based research and development of new technologies focusing on current plans to explore planets, moons, asteroids and comets -- all members of the solar system family. This year's race will be held March 30 - April 1, 2017, at the U.S. Space & Rocket Center in Huntsville, Alabama. The challenge will focus on designing, constructing and testing technologies for mobility devices to perform in these different environments, and it will provide valuable experiences that engage students in the technologies and concepts that will be needed in future exploration missions. Rovers will be human-powered and carry two students, one female and one male, over a half-mile obstacle course of simulated extraterrestrial terrain of craters, boulders, ridges, inclines, crevasses and depressions. Follow them on social media at: TWITTER: https://twitter.com/RoverChallenge FACEBOOK: https://www.facebook.com/roverchallenge/ Or visit the website at: www.nasa.gov/roverchallenge

PRIMUS: autonomous navigation in open terrain with a tracked vehicle

NASA Astrophysics Data System (ADS)

Schaub, Guenter W.; Pfaendner, Alfred H.; Schaefer, Christoph

2004-09-01

The German experimental robotics program PRIMUS (PRogram for Intelligent Mobile Unmanned Systems) is focused on solutions for autonomous driving in unknown open terrain, over several project phases under specific realization aspects for more than 12 years. The main task of the program is to develop algorithms for a high degree of autonomous navigation skills with off-the-shelf available hardware/sensor technology and to integrate this into military vehicles. For obstacle detection a Dornier-3D-LADAR is integrated on a tracked vehicle "Digitized WIESEL 2". For road-following a digital video camera and a visual perception module from the Universitaet der Bundeswehr Munchen (UBM) has been integrated. This paper gives an overview of the PRIMUS program with a focus on the last program phase D (2001 - 2003). This includes the system architecture, the description of the modes of operation and the technology development with the focus on obstacle avoidance and obstacle classification using a 3-D LADAR. A collection of experimental results and a short look at the next steps in the German robotics program will conclude the paper.

Autonomous collision avoidance system by combined control of steering and braking using geometrically optimised vehicular trajectory

NASA Astrophysics Data System (ADS)

Hayashi, Ryuzo; Isogai, Juzo; Raksincharoensak, Pongsathorn; Nagai, Masao

2012-01-01

This study proposes an autonomous obstacle avoidance system not only by braking but also by steering, as one of the active safety technologies to prevent traffic accidents. The proposed system prevents the vehicle from colliding with a moving obstacle like a pedestrian jumping out from the roadside. In the proposed system, to avoid the predicted colliding position based on constant-velocity obstacle motion assumption, the avoidance trajectory is derived as connected two identical arcs. The system then controls the vehicle autonomously by the combined control of the braking and steering systems. In this paper, the proposed system is examined by real car experiments and its effectiveness is shown from the results of the experiments.

Implementation of Web-Based Education in Egypt through Cloud Computing Technologies and Its Effect on Higher Education

ERIC Educational Resources Information Center

El-Seoud, M. Samir Abou; El-Sofany, Hosam F.; Taj-Eddin, Islam A. T. F.; Nosseir, Ann; El-Khouly, Mahmoud M.

2013-01-01

The information technology educational programs at most universities in Egypt face many obstacles that can be overcome using technology enhanced learning. An open source Moodle eLearning platform has been implemented at many public and private universities in Egypt, as an aid to deliver e-content and to provide the institution with various…

Unexploded Ordnance Clearance: A Coordinated Approach to Requirements and Technology Development.

DTIC Science & Technology

1997-03-25

ID #23) Clear mines and obstacles in a 50-meter-wide lane through the surf H N N N N zone and beach in order to land Landing Craft Air Cushion (LCAC...ID #33) Clear the surf zone (SZ) and beach zone (BZ) of mines and H N L N N obstacles in order to land LCAC during amphibious assaults and...Range Clearance All areas Commercial Off The Shelf (COTS) or military adapted -equipment, EOD technicians, DoD civilians, locally hired service

Technology Adoption in Higher Education: Overcoming Anxiety through Faculty Bootcamp

ERIC Educational Resources Information Center

Johnson, Terri; Wisniewski, Mary Ann; Kuhlemeyer, Greg; Isaacs, Gerald; Krzykowski, Jamie

2012-01-01

The reluctance to design and teach online courses in higher education is often attributed to technology anxiety in faculty. This article documents a faculty development model that has successfully helped faculty overcome this obstacle. "Bootcamps," faculty development programs held at Carroll University in Waukesha, WI, were specifically and…

Promoting High-Performance Computing and Communications. A CBO Study.

ERIC Educational Resources Information Center

Webre, Philip

In 1991 the Federal Government initiated the multiagency High Performance Computing and Communications program (HPCC) to further the development of U.S. supercomputer technology and high-speed computer network technology. This overview by the Congressional Budget Office (CBO) concentrates on obstacles that might prevent the growth of the…

Digital Exclusion: Coming out from behind Closed Doors

ERIC Educational Resources Information Center

Watling, Sue

2011-01-01

Government visions of a digital future show little indication of how disabled people, reliant on access technology, will participate. Access technology has the potential to offer independent use of the Internet but many disabled people already face barriers that prevent them having equitable digital experiences. Multiple obstacles include high…

Virtual obstacle crossing: Reliability and differences in stroke survivors who prospectively experienced falls or no falls.

PubMed

Punt, Michiel; Bruijn, Sjoerd M; Wittink, Harriet; van de Port, Ingrid G; Wubbels, Gijs; van Dieën, Jaap H

2017-10-01

Stroke survivors often fall during walking. To reduce fall risk, gait testing and training with avoidance of virtual obstacles is gaining popularity. However, it is unknown whether and how virtual obstacle crossing is associated with fall risk. The present study assessed whether obstacle crossing characteristics are reliable and assessed differences in stroke survivors who prospectively experienced falls or no falls. We recruited twenty-nine community dwelling chronic stroke survivors. Participants crossed five virtual obstacles with increasing lengths. After a break, the test was repeated to assess test-retest reliability. For each obstacle length and trial, we determined; success rate, leading limb preference, pre and post obstacle distance, margins of stability, toe clearance, and crossing step length and speed. Subsequently, fall incidence was monitored using a fall calendar and monthly phone calls over a six-month period. Test-retest reliability was poor, but improved with increasing obstacle-length. Twelve participants reported at least one fall. No association of fall incidence with any of the obstacle crossing characteristics was found. Given the absence of height of the virtual obstacles, obstacle avoidance may have been relatively easy, allowing participants to cross obstacles in multiple ways, increasing variability of crossing characteristics and reducing the association with fall risk. These finding cast some doubt on current protocols for testing and training of obstacle avoidance in stroke rehabilitation. Copyright © 2017 Elsevier B.V. All rights reserved.

Electrode-stress-induced nanoscale disorder in Si quantum electronic devices

DOE PAGES

Park, J.; Ahn, Y.; Tilka, J. A.; ...

2016-06-20

Disorder in the potential-energy landscape presents a major obstacle to the more rapid development of semiconductor quantum device technologies. We report a large-magnitude source of disorder, beyond commonly considered unintentional background doping or fixed charge in oxide layers: nanoscale strain fields induced by residual stresses in nanopatterned metal gates. Quantitative analysis of synchrotron coherent hard x-ray nanobeam diffraction patterns reveals gate-induced curvature and strains up to 0.03% in a buried Si quantum well within a Si/SiGe heterostructure. Furthermore, electrode stress presents both challenges to the design of devices and opportunities associated with the lateral manipulation of electronic energy levels.

Why won't they listen: Negotiating the technological and social context for science teaching

NASA Astrophysics Data System (ADS)

Liuzzo, Anna M.

The purpose of this study was to gather information to identify the obstacles and the impact an implementation of technology had in a middle school science classroom. This study explored a teaching environment where the teacher planned on using a variety of technology tools including laptops, probeware, hardware and software to promote scientific study. This study took place in two phases consisting of three consecutive years. In phase one the teacher reported great success. In phase two a shift in the school implementation created a significant impact on the learning taking place. This study identified the obstacles faced by a teacher providing an environment that combined her pedagogy with technology implementation. This teacher's pedagogy included research-based practices such a authentic problem-based learning, scientific inquiry, conceptual understanding of problem solving, connections to real-life situations and the use of metacognition in her practice. This study looked to determined if this implementation had an effect on student engagement and achievement; how the nature of technical and professional development impacted the implementation; and the barriers that were faced in creating a student-centered, technology rich approach to science. This qualitative study was conducted meeting the criteria of a case study of one teacher. The participant teacher's accounts of events through interviews were the primary source of data. In addition, multiple sources of information were also gathered. These included the teacher's reflective journal, student interviews, student focus groups, student artifacts, classroom observations, field notes, e-mail correspondences and students' test scores. This study proposes to contribute to the growing research evidence of implementation in the classroom and to identify specific obstacles that hinder success. The current state of education is calling for reform.

A stochastic differential equation model for the foraging behavior of fish schools.

PubMed

Tạ, Tôn Việt; Nguyen, Linh Thi Hoai

2018-03-15

Constructing models of living organisms locating food sources has important implications for understanding animal behavior and for the development of distribution technologies. This paper presents a novel simple model of stochastic differential equations for the foraging behavior of fish schools in a space including obstacles. The model is studied numerically. Three configurations of space with various food locations are considered. In the first configuration, fish swim in free but limited space. All individuals can find food with large probability while keeping their school structure. In the second and third configurations, they move in limited space with one and two obstacles, respectively. Our results reveal that the probability of foraging success is highest in the first configuration, and smallest in the third one. Furthermore, when school size increases up to an optimal value, the probability of foraging success tends to increase. When it exceeds an optimal value, the probability tends to decrease. The results agree with experimental observations.

Robot soccer anywhere: achieving persistent autonomous navigation, mapping, and object vision tracking in dynamic environments

NASA Astrophysics Data System (ADS)

Dragone, Mauro; O'Donoghue, Ruadhan; Leonard, John J.; O'Hare, Gregory; Duffy, Brian; Patrikalakis, Andrew; Leederkerken, Jacques

2005-06-01

The paper describes an ongoing effort to enable autonomous mobile robots to play soccer in unstructured, everyday environments. Unlike conventional robot soccer competitions that are usually held on purpose-built robot soccer "fields", in our work we seek to develop the capability for robots to demonstrate aspects of soccer-playing in more diverse environments, such as schools, hospitals, or shopping malls, with static obstacles (furniture) and dynamic natural obstacles (people). This problem of "Soccer Anywhere" presents numerous research challenges including: (1) Simultaneous Localization and Mapping (SLAM) in dynamic, unstructured environments, (2) software control architectures for decentralized, distributed control of mobile agents, (3) integration of vision-based object tracking with dynamic control, and (4) social interaction with human participants. In addition to the intrinsic research merit of these topics, we believe that this capability would prove useful for outreach activities, in demonstrating robotics technology to primary and secondary school students, to motivate them to pursue careers in science and engineering.

A stochastic differential equation model for the foraging behavior of fish schools

NASA Astrophysics Data System (ADS)

Tạ, Tôn ệt, Vi; Hoai Nguyen, Linh Thi

2018-05-01

Constructing models of living organisms locating food sources has important implications for understanding animal behavior and for the development of distribution technologies. This paper presents a novel simple model of stochastic differential equations for the foraging behavior of fish schools in a space including obstacles. The model is studied numerically. Three configurations of space with various food locations are considered. In the first configuration, fish swim in free but limited space. All individuals can find food with large probability while keeping their school structure. In the second and third configurations, they move in limited space with one and two obstacles, respectively. Our results reveal that the probability of foraging success is highest in the first configuration, and smallest in the third one. Furthermore, when school size increases up to an optimal value, the probability of foraging success tends to increase. When it exceeds an optimal value, the probability tends to decrease. The results agree with experimental observations.

Assistive obstacle detection and navigation devices for vision-impaired users.

PubMed

Ong, S K; Zhang, J; Nee, A Y C

2013-09-01

Quality of life for the visually impaired is an urgent worldwide issue that needs to be addressed. Obstacle detection is one of the most important navigation tasks for the visually impaired. In this research, a novel range sensor placement scheme is proposed in this paper for the development of obstacle detection devices. Based on this scheme, two prototypes have been developed targeting at different user groups. This paper discusses the design issues, functional modules and the evaluation tests carried out for both prototypes. Implications for Rehabilitation Visual impairment problem is becoming more severe due to the worldwide ageing population. Individuals with visual impairment require assistance from assistive devices in daily navigation tasks. Traditional assistive devices that assist navigation may have certain drawbacks, such as the limited sensing range of a white cane. Obstacle detection devices applying the range sensor technology can identify road conditions with a higher sensing range to notify the users of potential dangers in advance.

Obstacles to Scientific Research in Light of a Number of Variables

ERIC Educational Resources Information Center

Algadheeb, Nourah A.; Almeqren, Monira A.

2014-01-01

The present study aimed to identify the scientific research obstacles facing faculty members in the College of Education at Princess Nora bint Abdul Rahman University (PNU) and to determine the differences in the obstacles according to age, academic rank, scientific specialty, marital status, number of completed studies, and time since the last…

Obstacle Classification and 3D Measurement in Unstructured Environments Based on ToF Cameras

PubMed Central

Yu, Hongshan; Zhu, Jiang; Wang, Yaonan; Jia, Wenyan; Sun, Mingui; Tang, Yandong

2014-01-01

Inspired by the human 3D visual perception system, we present an obstacle detection and classification method based on the use of Time-of-Flight (ToF) cameras for robotic navigation in unstructured environments. The ToF camera provides 3D sensing by capturing an image along with per-pixel 3D space information. Based on this valuable feature and human knowledge of navigation, the proposed method first removes irrelevant regions which do not affect robot's movement from the scene. In the second step, regions of interest are detected and clustered as possible obstacles using both 3D information and intensity image obtained by the ToF camera. Consequently, a multiple relevance vector machine (RVM) classifier is designed to classify obstacles into four possible classes based on the terrain traversability and geometrical features of the obstacles. Finally, experimental results in various unstructured environments are presented to verify the robustness and performance of the proposed approach. We have found that, compared with the existing obstacle recognition methods, the new approach is more accurate and efficient. PMID:24945679

Hemorrhage and culture: management in the developing world and cultural implications for nursing care.

PubMed

Penney, D S

1991-01-01

In the industrialized world, technological resources and skilled personnel characterize the response to a hemorrhagic crisis. Such an efficient use of supplied technology stands in stark contrast to the responses toward a similar crisis when encountered in a developing country. In fact, attempting to manage a hemorrhage in a developing country may pose entanglements with economic, political, cultural, environmental, and medical obstacles. The uniqueness of this task and its challenges to the health professional are presented to provide nurses in advanced societies with a basic understanding of principles involved in managing hemorrhage in less-than-ideal circumstances. In addition, cultural care considerations are briefly described as they relate to the nursing role in the developing world.

Overview of a HLA-Ig based "Lego-like system" for T cell monitoring, modulation and expansion.

PubMed

Oelke, Mathias; Schneck, Jonathan P

2010-07-01

Recent advances in molecular medicine have shown that soluble MHC-multimers can be valuable tools for both analysis and modulation of antigen-specific immune responses in vitro and in vivo. In this review, we describe the use of dimeric human and mouse major histocompatibility complexes, MHC-Ig, as part of an artificial Antigen-Presenting Cell (aAPC). MHC-Ig-based aAPC and its derivatives represent an exciting new platform technology for measuring and manipulating immune responses in vitro as well as in vivo. This new technology has the potential to help overcome many of the obstacles associated with limitations in current antigen-specific approaches of immunotherapy for the treatment of cancer, infectious diseases and autoimmunity.

Laminar CuO-water nano-fluid flow and heat transfer in a backward-facing step with and without obstacle

NASA Astrophysics Data System (ADS)

Togun, Hussein

2016-03-01

This paper presents a numerical investigate on CuO-water nano-fluid and heat transfer in a backward-facing step with and without obstacle. The range of Reynolds number varied from 75 to 225 with volume fraction on CuO nanoparticles varied from 1 to 4 % at constant heat flux was investigated. Continuity, momentum, and energy equations with finite volume method in two dimensions were employed. Four different configurations of backward-facing step (without obstacle, with obstacle of 1.5 mm, with obstacle of 3 mm, with obstacle of 4.5 mm) were considered to find the best thermal performance. The results show that the maximum augmentation in heat transfer was about 22 % for backward-facing step with obstacle of 4.5 mm and using CuO nanoparticles at Reynolds number of 225 compared with backward-facing step without obstacle. It is also observed that increase in size of recirculation region with increase of height obstacle on the channel wall has remarkable effect on thermal performance. The results also found that increases in Reynolds number, height obstacle, and volume fractions of CuO nanoparticles lead to increase of pressure drop.

Emerging Web Technologies in Higher Education: A Case of Incorporating Blogs, Podcasts and Social Bookmarks in a Web Programming Course Based on Students' Learning Styles and Technology Preferences

ERIC Educational Resources Information Center

Saeed, Nauman; Yang, Yun; Sinnappan, Suku

2009-01-01

The adoption level of emerging web technologies is on the rise in academic settings. However, a major obstacle in the practice of web-based instruction is the limited understanding of learners' characteristics and perceptions about technology use. Thus there is a need to understand the relationship between students' learning styles and their…

Passive detection of subpixel obstacles for flight safety

NASA Astrophysics Data System (ADS)

Nixon, Matthew D.; Loveland, Rohan C.

2001-12-01

Military aircraft fly below 100 ft. above ground level in support of their missions. These aircraft include fixed and rotary wing and may be manned or unmanned. Flying at these low altitudes presents a safety hazard to the aircrew and aircraft, due to the occurrences of obstacles within the aircraft's flight path. The pilot must rely on eyesight and in some cases, infrared sensors to see obstacles. Many conditions can exacerbate visibility creating a situation in which obstacles are essentially invisible, creating a safety hazard, even to an alerted aircrew. Numerous catastrophic accidents have occurred in which aircraft have collided with undetected obstacles. Accidents of this type continue to be a problem for low flying military and commercial aircraft. Unmanned Aerial Vehicles (UAVs) have the same problem, whether operating autonomously or under control of a ground operator. Boeing-SVS has designed a passive, small, low- cost (under $100k) gimbaled, infrared imaging based system with advanced obstacle detection algorithms. Obstacles are detected in the infrared band, and linear features are analyzed by innovative cellular automata based software. These algorithms perform detection and location of sub-pixel linear features. The detection of the obstacles is performed on a frame by frame basis, in real time. Processed images are presented to the aircrew on their display as color enhanced features. The system has been designed such that the detected obstacles are displayed to the aircrew in sufficient time to react and maneuver the aircraft to safety. A patent for this system is on file with the US patent office, and all material herein should be treated accordingly.

Tracked robot controllers for climbing obstacles autonomously

NASA Astrophysics Data System (ADS)

Vincent, Isabelle

2009-05-01

Research in mobile robot navigation has demonstrated some success in navigating flat indoor environments while avoiding obstacles. However, the challenge of analyzing complex environments to climb obstacles autonomously has had very little success due to the complexity of the task. Unmanned ground vehicles currently exhibit simple autonomous behaviours compared to the human ability to move in the world. This paper presents the control algorithms designed for a tracked mobile robot to autonomously climb obstacles by varying its tracks configuration. Two control algorithms are proposed to solve the autonomous locomotion problem for climbing obstacles. First, a reactive controller evaluates the appropriate geometric configuration based on terrain and vehicle geometric considerations. Then, a reinforcement learning algorithm finds alternative solutions when the reactive controller gets stuck while climbing an obstacle. The methodology combines reactivity to learning. The controllers have been demonstrated in box and stair climbing simulations. The experiments illustrate the effectiveness of the proposed approach for crossing obstacles.

Removing Obstacles to the Pedagogical Changes Required by Jonassen's Vision of Authentic Technology-Enabled Learning

ERIC Educational Resources Information Center

Ertmer, Peggy A.; Ottenbreit-Leftwich, Anne

2013-01-01

Educators have been striving to achieve meaningful technology use in our K-12 classrooms for over 30 years. Yet, despite significant investments of time and money in infrastructure, training, and support "we have few assurances that [educators] are able to use technology for teaching and learning" (NEA, 2008, p. 1). In this article, we call for a…

Reality of Educational Technology Use in Primary Level Social Studies Teaching in North West Badiya Education District Schools in Mafraq Governorate

ERIC Educational Resources Information Center

Menazel, Basil H.

2016-01-01

The study aimed to identify the use of educational technology in social studies teaching and the obstacles to availability and use of educational technology in teaching social studies at schools in the North West Badiya Education Directorate in Mafraq governorate, the Hashemite Kingdom of Jordan. The study population comprised of 137 male and…

Depleted Trust in the Cyber Commons

DTIC Science & Technology

2012-01-01

information and communications technology ], to reduce collective risk and protect critical national and international in­ frastructure.”1 Since then, the...its users does not meet most conditions that encourage such self-organization. Both the affordances of the cyber technologies —that is, the way the... technologies enable their use—and the mentalities of the users contribute to the unfavorable result. Embedding the obstacles to international

E-inclusion Process and Societal Digital Skill Development

ERIC Educational Resources Information Center

Vitolina, Ieva

2015-01-01

Nowadays, the focus shifts from information and communication technology access to skills and knowledge. Moreover, lack of digital skills is an obstacle in the process of learning new digital competences using technologies and e-learning. The objective of this research is to investigate how to facilitate students to use the acquired digital skills…

Forecasting the Impact of Technological Change on Manpower Utilization and Displacement: An Analytic Summary.

ERIC Educational Resources Information Center

Fechter, Alan

Obstacles to producing forecasts of the impact of technological change and skill utilization are briefly discussed, and existing models for forecasting manpower requirements are described and analyzed. A survey of current literature reveals a concentration of models for producing long-range national forecasts, but few models for generating…

Gender, Information Technology, and Developing Countries: An Analytic Study.

ERIC Educational Resources Information Center

Hafkin, Nancy; Taggart, Nancy

This report and executive summary examines the current situation of gender and information technology (IT) in developing nations. The first section describes women as users of IT, producers of IT, and IT decision makers. The second section notes obstacles to women's access (literacy and education, language, time, cost, geographic location, social…

Taking on the Heat--A Narrative Account of How Infrared Cameras Invite Instant Inquiry

ERIC Educational Resources Information Center

Haglund, Jesper; Jeppsson, Fredrik; Schönborn, Konrad J.

2016-01-01

Integration of technology, social learning and scientific models offers pedagogical opportunities for science education. A particularly interesting area is thermal science, where students often struggle with abstract concepts, such as heat. In taking on this conceptual obstacle, we explore how hand-held infrared (IR) visualization technology can…

Administrative Obstacles to Technology Use in West Virginia Public Schools: A Survey of West Virginia Principals

ERIC Educational Resources Information Center

Agnew, David W.

2011-01-01

Public school principals must meet many challenges and make decisions concerning financial obligations while providing the best learning environment for students. A major challenge to principals is implementing technological components successfully while providing teachers the 21st century instructional skills needed to enhance students'…

Rural Veteran Access to Healthcare Services: Investigating the Role of Information and Communication Technologies in Overcoming Spatial Barriers

PubMed Central

Schooley, Benjamin L; Horan, Thomas A; Lee, Pamela W; West, Priscilla A

2010-01-01

This multimethod pilot study examined patient and practitioner perspectives on the influence of spatial barriers to healthcare access and the role of health information technology in overcoming these barriers. The study included a survey administered to patients attending a Department of Veterans Affairs (VA) health visit, and a focus group with VA care providers. Descriptive results and focus group findings are presented. Spatial distance is a significant factor for many rural veterans when seeking healthcare. For this sample of rural veterans, a range of telephone, computer, and Internet technologies may become more important for accessing care as Internet access becomes more ubiquitous and as younger veterans begin using the VA health system. The focus group highlighted the negative impact of distance, economic considerations, geographic barriers, and specific medical conditions on access to care. Lack of adequate technology infrastructure was seen as an obstacle to utilization. This study discusses the need to consider distance, travel modes, age, and information technology infrastructure and adoption when designing health information technology to care for rural patients. PMID:20697468

Three-dimensional landing zone ladar

NASA Astrophysics Data System (ADS)

Savage, James; Goodrich, Shawn; Burns, H. N.

2016-05-01

Three-Dimensional Landing Zone (3D-LZ) refers to a series of Air Force Research Laboratory (AFRL) programs to develop high-resolution, imaging ladar to address helicopter approach and landing in degraded visual environments with emphasis on brownout; cable warning and obstacle avoidance; and controlled flight into terrain. Initial efforts adapted ladar systems built for munition seekers, and success led to a the 3D-LZ Joint Capability Technology Demonstration (JCTD) , a 27-month program to develop and demonstrate a ladar subsystem that could be housed with the AN/AAQ-29 FLIR turret flown on US Air Force Combat Search and Rescue (CSAR) HH-60G Pave Hawk helicopters. Following the JCTD flight demonstration, further development focused on reducing size, weight, and power while continuing to refine the real-time geo-referencing, dust rejection, obstacle and cable avoidance, and Helicopter Terrain Awareness and Warning (HTAWS) capability demonstrated under the JCTD. This paper summarizes significant ladar technology development milestones to date, individual LADAR technologies within 3D-LZ, and results of the flight testing.

Weird Project: E-Health Service Improvement Using WiMAX

NASA Astrophysics Data System (ADS)

Cimmino, Antonio; Casali, Fulvio; Mambretti, Cinzia

Today the major obstacle to massive deployment of telemedicine applications are the security issues related to the exchange of real time information between different elements that are not at fixed locations. WiMAX, the new standard for wireless communications, is one of the most promising technologies for broadband access in a fixed and mobile environment and it is expected to overcome the above mentioned obstacle. The FP6-WEIRD [1] (WiMax Extension to Isolated Remote Data networks) project has: analysed how this technology can guarantee secure real time data transmission between mobile elements, built some successful demonstrations and paved the way to future commercial applications. This paper in particular describes: main promising e-health applications that WiMax would enable; the technological highlights and the main challenges that WiMax has to face in e-health applications such as accounting, privacy, security, data integrity; the way in which the WEIRD project 0 has studied the wireless access to medical communities and equipment in remote or impervious areas. 0 0; some envisaged implementations.

Autonomous navigation and obstacle avoidance for unmanned surface vehicles

NASA Astrophysics Data System (ADS)

Larson, Jacoby; Bruch, Michael; Ebken, John

2006-05-01

The US Navy and other Department of Defense (DoD) and Department of Homeland Security (DHS) organizations are increasingly interested in the use of unmanned surface vehicles (USVs) for a variety of missions and applications. In order for USVs to fill these roles, they must be capable of a relatively high degree of autonomous navigation. Space and Naval Warfare Systems Center, San Diego is developing core technologies required for robust USV operation in a real-world environment, primarily focusing on autonomous navigation, obstacle avoidance, and path planning.

Dynamic Obstacle Avoidance for Unmanned Underwater Vehicles Based on an Improved Velocity Obstacle Method

PubMed Central

Zhang, Wei; Wei, Shilin; Teng, Yanbin; Zhang, Jianku; Wang, Xiufang; Yan, Zheping

2017-01-01

In view of a dynamic obstacle environment with motion uncertainty, we present a dynamic collision avoidance method based on the collision risk assessment and improved velocity obstacle method. First, through the fusion optimization of forward-looking sonar data, the redundancy of the data is reduced and the position, size and velocity information of the obstacles are obtained, which can provide an accurate decision-making basis for next-step collision avoidance. Second, according to minimum meeting time and the minimum distance between the obstacle and unmanned underwater vehicle (UUV), this paper establishes the collision risk assessment model, and screens key obstacles to avoid collision. Finally, the optimization objective function is established based on the improved velocity obstacle method, and a UUV motion characteristic is used to calculate the reachable velocity sets. The optimal collision speed of UUV is searched in velocity space. The corresponding heading and speed commands are calculated, and outputted to the motion control module. The above is the complete dynamic obstacle avoidance process. The simulation results show that the proposed method can obtain a better collision avoidance effect in the dynamic environment, and has good adaptability to the unknown dynamic environment. PMID:29186878

Using Multidisciplinary Focus Groups to Inform the Development of mI SMART: A Nurse-Led Technology Intervention for Multiple Chronic Conditions

PubMed Central

Theeke, Laurie A.; Theeke, Elliott; Mallow, Brian K.

2016-01-01

Used as integrated tools, technology may improve the ability of healthcare providers to improve access and outcomes of care. Little is known about healthcare teams' preferences in using such technology. This paper reports the findings from focus groups aimed at evaluating a newly developed primary care technology platform. Focus groups were completed in academic, outpatient, and community settings. Focus groups were attended by 37 individuals. The participants included professionals from multiple disciplines. Both prescribing (N = 8) and nonprescribing healthcare team members (n = 21) completed the focus groups and survey. The majority were practicing for more than 20 years (44.8%) in an outpatient clinic (62%) for 20–40 hours per week (37.9%). Providers identified perceived obstacles of patient use as ability, willingness, and time. System obstacles were identified as lack of integration, lack of reimbursement, and cost. The positive attributes of the developed system were capability for virtual visits, readability, connectivity, user-friendliness, ability to capture biophysical measures, enhanced patient access, and incorporation of multiple technologies. Providers suggested increasing capability for biophysical and symptom monitoring for more common chronic conditions. Technology interventions have the potential to improve access and outcomes but will not be successful without the input of users. PMID:27504199

Brownian motion on random dynamical landscapes

NASA Astrophysics Data System (ADS)

Suñé Simon, Marc; Sancho, José María; Lindenberg, Katja

2016-03-01

We present a study of overdamped Brownian particles moving on a random landscape of dynamic and deformable obstacles (spatio-temporal disorder). The obstacles move randomly, assemble, and dissociate following their own dynamics. This landscape may account for a soft matter or liquid environment in which large obstacles, such as macromolecules and organelles in the cytoplasm of a living cell, or colloids or polymers in a liquid, move slowly leading to crowding effects. This representation also constitutes a novel approach to the macroscopic dynamics exhibited by active matter media. We present numerical results on the transport and diffusion properties of Brownian particles under this disorder biased by a constant external force. The landscape dynamics are characterized by a Gaussian spatio-temporal correlation, with fixed time and spatial scales, and controlled obstacle concentrations.

A novel architecture of non-volatile magnetic arithmetic logic unit using magnetic tunnel junctions

NASA Astrophysics Data System (ADS)

Guo, Wei; Prenat, Guillaume; Dieny, Bernard

2014-04-01

Complementary metal-oxide-semiconductor (CMOS) technology is facing increasingly difficult obstacles such as power consumption and interconnection delay. Novel hybrid technologies and architectures are being investigated with the aim to circumvent some of these limits. In particular, hybrid CMOS/magnetic technology based on magnetic tunnel junctions (MTJs) is considered as a very promising approach thanks to the full compatibility of MTJs with CMOS technology. By tightly merging the conventional electronics with magnetism, both logic and memory functions can be implemented in the same device. As a result, non-volatility is directly brought into logic circuits, yielding significant improvement of device performances and new functionalities as well. We have conceived an innovative methodology to construct non-volatile magnetic arithmetic logic units (MALUs) combining spin-transfer torque MTJs with MOS transistors. The present 4-bit MALU utilizes 4 MTJ pairs to store its operation code (opcode). Its operations and performances have been confirmed and evaluated through electrical simulations.

Dealing with Unseen Obstacles to Education in the Digital Age

ERIC Educational Resources Information Center

Powell, Valerie J. H.; Sirinterlikci, Arif; Zomp, Christopher; Johnson, Randall S.; Miller, Phillip; Powell, James C.

2013-01-01

This paper updates the efforts to educate blind students in higher education in the digital age and describes how to support the development of mental models in learning through tactile learning and 3D-printing technology. It cites research documenting a drop in Braille literacy along with the growth in use of digital technologies by blind…

A Review of Research Literature on Obstacles That Prevent Use of ICT in Pre-Service Teachers' Educational Courses

ERIC Educational Resources Information Center

Mirzajani, Hassan; Mahmud, Rosnaini; Ayub, Ahmad Fauzi Mohd; Luan, Wong Su

2015-01-01

In spite of growing amount of technologies, tools and information communication and technology (ICT) by providing pre-service teacher education courses, pre-service teachers' ICT utilization is not still as predicted. Research shows many barriers influencing pre-service teachers' utilization of ICT. Many researchers have identified a number of…

Student Teachers' Discourse about Digital Technologies and Transitions between Formal and Informal Learning Contexts

ERIC Educational Resources Information Center

Pöntinen, Susanna; Dillon, Patrick; Väisänen, Pertti

2017-01-01

This research is a contribution to issues of digital technology use at the interface of formal and informal learning contexts. The research was conducted in the discourse tradition and investigates Finnish teacher training students' 'manners of speaking' as resources for, and obstacles to, making pedagogical changes in response to the potential of…

A parallel implementation of a multisensor feature-based range-estimation method

NASA Technical Reports Server (NTRS)

Suorsa, Raymond E.; Sridhar, Banavar

1993-01-01

There are many proposed vision based methods to perform obstacle detection and avoidance for autonomous or semi-autonomous vehicles. All methods, however, will require very high processing rates to achieve real time performance. A system capable of supporting autonomous helicopter navigation will need to extract obstacle information from imagery at rates varying from ten frames per second to thirty or more frames per second depending on the vehicle speed. Such a system will need to sustain billions of operations per second. To reach such high processing rates using current technology, a parallel implementation of the obstacle detection/ranging method is required. This paper describes an efficient and flexible parallel implementation of a multisensor feature-based range-estimation algorithm, targeted for helicopter flight, realized on both a distributed-memory and shared-memory parallel computer.

Age-related changes in gait adaptability in response to unpredictable obstacles and stepping targets.

PubMed

Caetano, Maria Joana D; Lord, Stephen R; Schoene, Daniel; Pelicioni, Paulo H S; Sturnieks, Daina L; Menant, Jasmine C

2016-05-01

A large proportion of falls in older people occur when walking. Limitations in gait adaptability might contribute to tripping; a frequently reported cause of falls in this group. To evaluate age-related changes in gait adaptability in response to obstacles or stepping targets presented at short notice, i.e.: approximately two steps ahead. Fifty older adults (aged 74±7 years; 34 females) and 21 young adults (aged 26±4 years; 12 females) completed 3 usual gait speed (baseline) trials. They then completed the following randomly presented gait adaptability trials: obstacle avoidance, short stepping target, long stepping target and no target/obstacle (3 trials of each). Compared with the young, the older adults slowed significantly in no target/obstacle trials compared with the baseline trials. They took more steps and spent more time in double support while approaching the obstacle and stepping targets, demonstrated poorer stepping accuracy and made more stepping errors (failed to hit the stepping targets/avoid the obstacle). The older adults also reduced velocity of the two preceding steps and shortened the previous step in the long stepping target condition and in the obstacle avoidance condition. Compared with their younger counterparts, the older adults exhibited a more conservative adaptation strategy characterised by slow, short and multiple steps with longer time in double support. Even so, they demonstrated poorer stepping accuracy and made more stepping errors. This reduced gait adaptability may place older adults at increased risk of falling when negotiating unexpected hazards. Copyright © 2016 Elsevier B.V. All rights reserved.

Computer vision techniques for rotorcraft low altitude flight

NASA Technical Reports Server (NTRS)

Sridhar, Banavar

1990-01-01

Rotorcraft operating in high-threat environments fly close to the earth's surface to utilize surrounding terrain, vegetation, or manmade objects to minimize the risk of being detected by an enemy. Increasing levels of concealment are achieved by adopting different tactics during low-altitude flight. Rotorcraft employ three tactics during low-altitude flight: low-level, contour, and nap-of-the-earth (NOE). The key feature distinguishing the NOE mode from the other two modes is that the whole rotorcraft, including the main rotor, is below tree-top whenever possible. This leads to the use of lateral maneuvers for avoiding obstacles, which in fact constitutes the means for concealment. The piloting of the rotorcraft is at best a very demanding task and the pilot will need help from onboard automation tools in order to devote more time to mission-related activities. The development of an automation tool which has the potential to detect obstacles in the rotorcraft flight path, warn the crew, and interact with the guidance system to avoid detected obstacles, presents challenging problems. Research is described which applies techniques from computer vision to automation of rotorcraft navigtion. The effort emphasizes the development of a methodology for detecting the ranges to obstacles in the region of interest based on the maximum utilization of passive sensors. The range map derived from the obstacle-detection approach can be used as obstacle data for the obstacle avoidance in an automatic guidance system and as advisory display to the pilot. The lack of suitable flight imagery data presents a problem in the verification of concepts for obstacle detection. This problem is being addressed by the development of an adequate flight database and by preprocessing of currently available flight imagery. The presentation concludes with some comments on future work and how research in this area relates to the guidance of other autonomous vehicles.

The results of the investigations of Russian Research Center - {open_quotes}Kurchatov Institute{close_quotes} on molten salt applications to problems of nuclear energy systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Novikov, V.M.

1995-10-01

The results of investigations on molten salt (MS) applications to problems of nuclear energy systems that have been conducted in Russian Research {open_quotes}Kurchatov Institute{close_quotes} are presented and discussed. The spectrum of these investigations is rather broad and covers the following items: physical characteristics of molten salt nuclear energy systems (MSNES); nuclear and radiation safety of MSNES; construction materials compatible with MS of different compositions; technological aspects of MS loops; in-reactor loop testing. It is shown that main findings of completed program support the conclusion that there are no physical nor technological obstacles on way of MS application to different nuclearmore » energy systems.« less

Real-Time Integrity Monitoring of Stored Geo-Spatial Data Using Forward-Looking Remote Sensing Technology

NASA Technical Reports Server (NTRS)

Young, Steven D.; Harrah, Steven D.; deHaag, Maarten Uijt

2002-01-01

Terrain Awareness and Warning Systems (TAWS) and Synthetic Vision Systems (SVS) provide pilots with displays of stored geo-spatial data (e.g. terrain, obstacles, and/or features). As comprehensive validation is impractical, these databases typically have no quantifiable level of integrity. This lack of a quantifiable integrity level is one of the constraints that has limited certification and operational approval of TAWS/SVS to "advisory-only" systems for civil aviation. Previous work demonstrated the feasibility of using a real-time monitor to bound database integrity by using downward-looking remote sensing technology (i.e. radar altimeters). This paper describes an extension of the integrity monitor concept to include a forward-looking sensor to cover additional classes of terrain database faults and to reduce the exposure time associated with integrity threats. An operational concept is presented that combines established feature extraction techniques with a statistical assessment of similarity measures between the sensed and stored features using principles from classical detection theory. Finally, an implementation is presented that uses existing commercial-off-the-shelf weather radar sensor technology.

Self-Reported Obstacles to Regular Dental Care among Information Technology Professionals.

PubMed

Reddy, L Swetha; Doshi, Dolar; Reddy, B Srikanth; Kulkarni, Suhas; Reddy, M Padma; Satyanarayana, D; Baldava, Pavan

2016-10-01

Good oral health is important for an individual as well as social well-being. Occupational stress and work exhaustion in Information Technology (IT) professionals may influence the oral health and oral health related quality of life. To assess and compare self-reported obstacles for regular dental care and dental visits among IT professionals based on age, gender, dental insurance and working days per week. A cross-sectional study was conducted among 1,017 IT professionals to assess the self-reported obstacles to regular oral health care in Hyderabad city, Telangana, India. The Dental Rejection of Innovation Scale (DRI-S) was employed in this study. Comparison between means of DRI-S based on variables was done using t-test and ANOVA. The association between variables and DRI-S was determined using Chi-square test. A total of 1017 participants comprising of 574 (56%) males and 443 (44%) females participated in the study. As age increased, a significant increase in mean DRI-S scores was seen for total and individual domains except for the "Situational" domain wherein higher mean score (9.42±2.5; p=0.0006) was observed among 30-39 years age group. Even though females reported higher mean scores for total and individual domains when compared to males, nevertheless significant difference was seen only for total (p=0.03) and "Lack of Knowledge" (p=0.001) domain. Self-reported obstacles to regular dental care was more with increasing age, increased number of working days per week, irregular dental visits and absence of dental insurance facility.

MMP Inhibitors: Past, present and future.

PubMed

Cathcart, Jillian M; Cao, Jian

2015-06-01

  Development of inhibitors of matrix metalloproteinases (MMPs) has been fraught with challenges. Early compounds largely failed due to poor selectivity and bioavailability. Dose-limiting side effects, off-target interactions, and improperly designed clinical trials significantly impeded clinical success. As information becomes available and technology evolves, tools to combat these obstacles have been developed. Improved methods for high throughput screening and drug design have led to identification of compounds exhibiting high potency, binding affinity, and favorable pharmacokinetic profiles. Current research into MMP inhibitors employs innovative approaches for drug delivery methods and allosteric inhibitors. Such innovation is key for development of clinically successful compounds.

2D/3D Synthetic Vision Navigation Display

NASA Technical Reports Server (NTRS)

Prinzel, Lawrence J., III; Kramer, Lynda J.; Arthur, J. J., III; Bailey, Randall E.; Sweeters, jason L.

2008-01-01

Flight-deck display software was designed and developed at NASA Langley Research Center to provide two-dimensional (2D) and three-dimensional (3D) terrain, obstacle, and flight-path perspectives on a single navigation display. The objective was to optimize the presentation of synthetic vision (SV) system technology that permits pilots to view multiple perspectives of flight-deck display symbology and 3D terrain information. Research was conducted to evaluate the efficacy of the concept. The concept has numerous unique implementation features that would permit enhanced operational concepts and efficiencies in both current and future aircraft.

Curb Mounting, Vertical Mobility, and Inverted Mobility on Rough Surfaces Using Microspine-Enabled Robots

NASA Technical Reports Server (NTRS)

Parness, Aaron

2012-01-01

Three robots that extend microspine technology to enable advanced mobility are presented. First, the Durable Reconnaissance and Observation Platform (DROP) and the ReconRobotics Scout platform use a new rotary configuration of microspines to provide improved soldier-portable reconnaissance by moving rapidly over curbs and obstacles, transitioning from horizontal to vertical surfaces, climbing rough walls and surviving impacts. Next, the four-legged LEMUR robot uses new configurations of opposed microspines to anchor to both manmade and natural rough surfaces. Using these anchors as feet enables mobility in unstructured environments, from urban disaster areas to deserts and caves.

Mapping a Path to Autonomous Flight in the National Airspace

NASA Technical Reports Server (NTRS)

Lodding, Kenneth N.

2011-01-01

The introduction of autonomous flight, whether military, commercial, or civilian, into the National Airspace System (NAS) will present significant challenges. Minimizing the impact and preventing the changes from becoming disruptive, rather than an enhancing technology will not be without difficulty. From obstacle detection and avoidance to real-time verification and validation of system behavior, there are significant problems which must be solved prior to the general acceptance of autonomous systems. This paper examines some of the key challenges and the multi-disciplinary collaboration which must occur for autonomous systems to be accepted as equal partners in the NAS.

Biologically-inspired adaptive obstacle negotiation behavior of hexapod robots

PubMed Central

Goldschmidt, Dennis; Wörgötter, Florentin; Manoonpong, Poramate

2014-01-01

Neurobiological studies have shown that insects are able to adapt leg movements and posture for obstacle negotiation in changing environments. Moreover, the distance to an obstacle where an insect begins to climb is found to be a major parameter for successful obstacle negotiation. Inspired by these findings, we present an adaptive neural control mechanism for obstacle negotiation behavior in hexapod robots. It combines locomotion control, backbone joint control, local leg reflexes, and neural learning. While the first three components generate locomotion including walking and climbing, the neural learning mechanism allows the robot to adapt its behavior for obstacle negotiation with respect to changing conditions, e.g., variable obstacle heights and different walking gaits. By successfully learning the association of an early, predictive signal (conditioned stimulus, CS) and a late, reflex signal (unconditioned stimulus, UCS), both provided by ultrasonic sensors at the front of the robot, the robot can autonomously find an appropriate distance from an obstacle to initiate climbing. The adaptive neural control was developed and tested first on a physical robot simulation, and was then successfully transferred to a real hexapod robot, called AMOS II. The results show that the robot can efficiently negotiate obstacles with a height up to 85% of the robot's leg length in simulation and 75% in a real environment. PMID:24523694

Excitation of Surface Electromagnetic Waves on Railroad Rail

DOT National Transportation Integrated Search

1978-03-31

UMTA's Office of Rail Technology research programs aim to improve urban rail transportation systems safety. This rail-transit research study attempts to develop an onboard, separate and independent obstacle-detection system--Surface Electromagnetic W...

Toward humanoid robots for operations in complex urban environments

NASA Astrophysics Data System (ADS)

Pratt, Jerry E.; Neuhaus, Peter; Johnson, Matthew; Carff, John; Krupp, Ben

2010-04-01

Many infantry operations in urban environments, such as building clearing, are extremely dangerous and difficult and often result in high casualty rates. Despite the fast pace of technological progress in many other areas, the tactics and technology deployed for many of these dangerous urban operation have not changed much in the last 50 years. While robots have been extremely useful for improvised explosive device (IED) detonation, under-vehicle inspection, surveillance, and cave exploration, there is still no fieldable robot that can operate effectively in cluttered streets and inside buildings. Developing a fieldable robot that can maneuver in complex urban environments is challenging due to narrow corridors, stairs, rubble, doors and cluttered doorways, and other obstacles. Typical wheeled and tracked robots have trouble getting through most of these obstacles. A bipedal humanoid is ideally shaped for many of these obstacles because its legs are long and skinny. Therefore it has the potential to step over large barriers, gaps, rocks, and steps, yet squeeze through narrow passageways, and through narrow doorways. By being able to walk with one foot directly in front of the other, humanoids also have the potential to walk over narrow "balance beam" style objects and can cross a narrow row of stepping stones. We describe some recent advances in humanoid robots, particularly recovery from disturbances, such as pushes and walking over rough terrain. Our disturbance recovery algorithms are based on the concept of Capture Points. An N-Step Capture Point is a point on the ground in which a legged robot can step to in order to stop in N steps. The N-Step Capture Region is the set of all N-Step Capture Points. In order to walk without falling, a legged robot must step somewhere in the intersection between an N-Step Capture Region and the available footholds on the ground. We present results of push recovery using Capture Points on our humanoid robot M2V2.

Path planning of decentralized multi-quadrotor based on fuzzy-cell decomposition algorithm

NASA Astrophysics Data System (ADS)

Iswanto, Wahyunggoro, Oyas; Cahyadi, Adha Imam

2017-04-01

The paper aims to present a design algorithm for multi quadrotor lanes in order to move towards the goal quickly and avoid obstacles in an area with obstacles. There are several problems in path planning including how to get to the goal position quickly and avoid static and dynamic obstacles. To overcome the problem, therefore, the paper presents fuzzy logic algorithm and fuzzy cell decomposition algorithm. Fuzzy logic algorithm is one of the artificial intelligence algorithms which can be applied to robot path planning that is able to detect static and dynamic obstacles. Cell decomposition algorithm is an algorithm of graph theory used to make a robot path map. By using the two algorithms the robot is able to get to the goal position and avoid obstacles but it takes a considerable time because they are able to find the shortest path. Therefore, this paper describes a modification of the algorithms by adding a potential field algorithm used to provide weight values on the map applied for each quadrotor by using decentralized controlled, so that the quadrotor is able to move to the goal position quickly by finding the shortest path. The simulations conducted have shown that multi-quadrotor can avoid various obstacles and find the shortest path by using the proposed algorithms.

A Monocular Vision Sensor-Based Obstacle Detection Algorithm for Autonomous Robots.

PubMed

Lee, Tae-Jae; Yi, Dong-Hoon; Cho, Dong-Il Dan

2016-03-01

This paper presents a monocular vision sensor-based obstacle detection algorithm for autonomous robots. Each individual image pixel at the bottom region of interest is labeled as belonging either to an obstacle or the floor. While conventional methods depend on point tracking for geometric cues for obstacle detection, the proposed algorithm uses the inverse perspective mapping (IPM) method. This method is much more advantageous when the camera is not high off the floor, which makes point tracking near the floor difficult. Markov random field-based obstacle segmentation is then performed using the IPM results and a floor appearance model. Next, the shortest distance between the robot and the obstacle is calculated. The algorithm is tested by applying it to 70 datasets, 20 of which include nonobstacle images where considerable changes in floor appearance occur. The obstacle segmentation accuracies and the distance estimation error are quantitatively analyzed. For obstacle datasets, the segmentation precision and the average distance estimation error of the proposed method are 81.4% and 1.6 cm, respectively, whereas those for a conventional method are 57.5% and 9.9 cm, respectively. For nonobstacle datasets, the proposed method gives 0.0% false positive rates, while the conventional method gives 17.6%.

Wifi-friendly building, enabling wifi signal indoor: an initial study

NASA Astrophysics Data System (ADS)

Suherman; Mubarakah, Naemah; Sagala, Romulo S.; Prayitno, Hendra

2018-03-01

The 802.11 network (wireless fidelity/WiFi) is the most common wireless infrastructure applied for internet access indoor. Widespread devices and installation simplicity make it better than similar technologies such as 802.16 and other 802.xx series. The access points are the most influential devices for indoor access. However, building indoor architectures contribute to the signal quality. Since WiFi installation in buildings becomes prevalent, the architecture should consider WiFi-friendliness into consideration. The more friendly the building to WiFi signal, the more efficient the 802.11 based wireless infrastructure. This paper present preliminary study how the building, specially the obstacle material, effects the WiFi signal propagation indoor. The study was performed by using ESP8266-based WiFi signal reader, to determine the impact indoor obstacles to WiFi signal propagation. The initial study shows that simple reflecting materials increase signal level about 1.14 dBm. WiFi-friendly building can be achieved by transforming building properties into signal interconnector. A simple photo frame with aluminium sheet insertion increase signal level on the second floor up to 6.56dBm.

Effective Use of Assistive Technologies for Inclusive Education in Developing Countries: Issues and Challenges from Two Case Studies

ERIC Educational Resources Information Center

Grönlund, Åke; Lim, Nena; Larsson, Hannu

2010-01-01

Developing countries face many obstacles in the process of implementing inclusive education (IE). Effective use of assistive technologies (AT) can help governments in developing countries achieve inclusive education by helping children with disabilities in schools. Despite the importance and positive impact of AT, prior research on the use of AT…

Gender Differences in the Field of Information Security Technology Management: A Qualitative, Phenomenological Study

ERIC Educational Resources Information Center

Johnson, Marcia L.

2013-01-01

This qualitative study explored why there are so few senior women in the information security technology management field and whether gender played a part in the achievement of women in the field. Extensive interviews were performed to capture the lived experiences of successful women in the field regarding the obstacles and common denominators of…

A Framework for Learning about Big Data with Mobile Technologies for Democratic Participation: Possibilities, Limitations, and Unanticipated Obstacles

ERIC Educational Resources Information Center

Philip, Thomas M.; Schuler-Brown, Sarah; Way, Winmar

2013-01-01

As Big Data becomes increasingly important in policy-making, research, marketing, and commercial applications, we argue that literacy in this domain is critical for engaged democratic participation and that peer-generated data from mobile technologies offer rich possibilities for students to learn about this new genre of data. Through the lens of…

Assistive technologies to address capabilities of people with dementia: From research to practice.

PubMed

Kenigsberg, Paul-Ariel; Aquino, Jean-Pierre; Bérard, Alain; Brémond, François; Charras, Kevin; Dening, Tom; Droës, Rose-Marie; Gzil, Fabrice; Hicks, Ben; Innes, Anthea; Nguyen, Mai; Nygård, Louise; Pino, Maribel; Sacco, Guillaume; Salmon, Eric; van der Roest, Henriëtte; Villet, Hervé; Villez, Marion; Robert, Philippe; Manera, Valeria

2017-01-01

Assistive technologies became pervasive and virtually present in all our life domains. They can be either an enabler or an obstacle leading to social exclusion. The Fondation Médéric Alzheimer gathered international experts of dementia care, with backgrounds in biomedical, human and social sciences, to analyze how assistive technologies can address the capabilities of people with dementia, on the basis of their needs. Discussion covered the unmet needs of people with dementia, the domains of daily life activities where assistive technologies can provide help to people with dementia, the enabling and empowering impact of technology to improve their safety and wellbeing, barriers and limits of use, technology assessment, ethical and legal issues. The capability approach (possible freedom) appears particularly relevant in person-centered dementia care and technology development. The focus is not on the solution, rather on what the person can do with it: seeing dementia as disability, with technology as an enabler to promote capabilities of the person, provides a useful framework for both research and practice. This article summarizes how these concepts took momentum in professional practice and public policies in the past 15 years (2000-2015), discusses current issues in the design, development and economic model of assistive technologies for people with dementia, and covers how these technologies are being used and assessed.

[Quality improvement potential in the pharmaceutical industry].

PubMed

Nusser, Michael

2007-01-01

The performance of the German pharmaceutical industry, future challenges and obstacles to quality improvement are assessed from a systems-of-innovation perspective, using appropriate innovation indicators. The current close-to-market performance indicators paint an unfavourable picture. Early R&D indicators (e.g., publications, patents), however, reveal a positive trend. A lot of obstacles to quality improvements are identified with respect to knowledge base, knowledge/technology transfer, industrial R&D processes, capital markets, market attractiveness and both regulatory and political framework conditions. On this basis, recommendations will finally be derived to improve quality in the pharmaceutical industry.

Report to the Chairman, Subcommittee on Investigations and Oversight, Committee on Science, Space, and Technology, House of Representatives. Geothermal Energy: Outlook limited for some uses but promising for geothermal heat pumps

NASA Astrophysics Data System (ADS)

1994-06-01

Heat from the Earth, or geothermal energy, has the potential to help meet the nation's electricity needs, yet it supplies less than 1% of the nation's electricity. This GAO review describes the potential for three uses of geothermal energy - electrical generation, direct-use applications, and geothermal heat pumps - and, for each of these uses, the obstacles to their development are identified, along with the efforts made by industry and the government to overcome these obstacles, and the environmental effects entailed.

High Throughput Sequencing for Detection of Foodborne Pathogens

PubMed Central

Sekse, Camilla; Holst-Jensen, Arne; Dobrindt, Ulrich; Johannessen, Gro S.; Li, Weihua; Spilsberg, Bjørn; Shi, Jianxin

2017-01-01

High-throughput sequencing (HTS) is becoming the state-of-the-art technology for typing of microbial isolates, especially in clinical samples. Yet, its application is still in its infancy for monitoring and outbreak investigations of foods. Here we review the published literature, covering not only bacterial but also viral and Eukaryote food pathogens, to assess the status and potential of HTS implementation to inform stakeholders, improve food safety and reduce outbreak impacts. The developments in sequencing technology and bioinformatics have outpaced the capacity to analyze and interpret the sequence data. The influence of sample processing, nucleic acid extraction and purification, harmonized protocols for generation and interpretation of data, and properly annotated and curated reference databases including non-pathogenic “natural” strains are other major obstacles to the realization of the full potential of HTS in analytical food surveillance, epidemiological and outbreak investigations, and in complementing preventive approaches for the control and management of foodborne pathogens. Despite significant obstacles, the achieved progress in capacity and broadening of the application range over the last decade is impressive and unprecedented, as illustrated with the chosen examples from the literature. Large consortia, often with broad international participation, are making coordinated efforts to cope with many of the mentioned obstacles. Further rapid progress can therefore be prospected for the next decade. PMID:29104564

Radar-based collision avoidance for unmanned surface vehicles

NASA Astrophysics Data System (ADS)

Zhuang, Jia-yuan; Zhang, Lei; Zhao, Shi-qi; Cao, Jian; Wang, Bo; Sun, Han-bing

2016-12-01

Unmanned surface vehicles (USVs) have become a focus of research because of their extensive applications. To ensure safety and reliability and to perform complex tasks autonomously, USVs are required to possess accurate perception of the environment and effective collision avoidance capabilities. To achieve these, investigation into realtime marine radar target detection and autonomous collision avoidance technologies is required, aiming at solving the problems of noise jamming, uneven brightness, target loss, and blind areas in marine radar images. These technologies should also satisfy the requirements of real-time and reliability related to high navigation speeds of USVs. Therefore, this study developed an embedded collision avoidance system based on the marine radar, investigated a highly real-time target detection method which contains adaptive smoothing algorithm and robust segmentation algorithm, developed a stable and reliable dynamic local environment model to ensure the safety of USV navigation, and constructed a collision avoidance algorithm based on velocity obstacle (V-obstacle) which adjusts the USV's heading and speed in real-time. Sea trials results in multi-obstacle avoidance firstly demonstrate the effectiveness and efficiency of the proposed avoidance system, and then verify its great adaptability and relative stability when a USV sailing in a real and complex marine environment. The obtained results will improve the intelligent level of USV and guarantee the safety of USV independent sailing.

Non-Economic Obstacles to Wind Deployment: Issues and Regional Differences (Presentation)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baring-Gould, I.

2014-05-01

This presentation provides an overview of national obstacles to wind deployment, with regional assessments. A special mention of offshore projects and distributed wind projects is provided. Detailed maps examine baseline capacity, military and flight radar, golden and bald eagle habitat, bat habitat, whooping crane habitat, and public lands. Regional deployment challenges are also discussed.

Natural solution to antibiotic resistance: bacteriophages 'The Living Drugs'.

PubMed

Jassim, Sabah A A; Limoges, Richard G

2014-08-01

Antibiotics have been a panacea in animal husbandry as well as in human therapy for decades. The huge amount of antibiotics used to induce the growth and protect the health of farm animals has lead to the evolution of bacteria that are resistant to the drug's effects. Today, many researchers are working with bacteriophages (phages) as an alternative to antibiotics in the control of pathogens for human therapy as well as prevention, biocontrol, and therapy in animal agriculture. Phage therapy and biocontrol have yet to fulfill their promise or potential, largely due to several key obstacles to their performance. Several suggestions are shared in order to point a direction for overcoming common obstacles in applied phage technology. The key to successful use of phages in modern scientific, farm, food processing and clinical applications is to understand the common obstacles as well as best practices and to develop answers that work in harmony with nature.

Research on Collection System Optimal Design of Wind Farm with Obstacles

NASA Astrophysics Data System (ADS)

Huang, W.; Yan, B. Y.; Tan, R. S.; Liu, L. F.

2017-05-01

To the collection system optimal design of offshore wind farm, the factors considered are not only the reasonable configuration of the cable and switch, but also the influence of the obstacles on the topology design of the offshore wind farm. This paper presents a concrete topology optimization algorithm with obstacles. The minimal area rectangle encasing box of the obstacle is obtained by using the method of minimal area encasing box. Then the optimization algorithm combining the advantages of Dijkstra algorithm and Prim algorithm is used to gain the scheme of avoidance obstacle path planning. Finally a fuzzy comprehensive evaluation model based on the analytic hierarchy process is constructed to compare the performance of the different topologies. Case studies demonstrate the feasibility of the proposed algorithm and model.

Generation of spiral waves pinned to obstacles in a simulated excitable system

NASA Astrophysics Data System (ADS)

Phantu, Metinee; Kumchaiseemak, Nakorn; Porjai, Porramain; Sutthiopad, Malee; Müller, Stefan C.; Luengviriya, Chaiya; Luengviriya, Jiraporn

2017-09-01

Pinning phenomena emerge in many dynamical systems. They are found to stabilize extreme conditions such as superconductivity and super fluidity. The dynamics of pinned spiral waves, whose tips trace the boundary of obstacles, also play an important role in the human health. In heart, such pinned waves cause longer tachycardia. In this article, we present two methods for generating pinned spiral waves in a simulated excitable system. In method A, an obstacle is set in the system prior to an ignition of a spiral wave. This method may be suitable only for the case of large obstacles since it often fails when used for small obstacles. In method B, a spiral wave is generated before an obstacle is placed at the spiral tip. With this method, a pinned spiral wave is always obtained, regardless the obstacle size. We demonstrate that after a transient interval the dynamics of the pinned spiral waves generated by the methods A and B are identical. The initiation of pinned spiral waves in both two- and three-dimensional systems is illustrated.

Refining the aggregate exposure pathway

EPA Science Inventory

Advancements in measurement technologies and modeling capabilities continue to result in an abundance of exposure information, adding to that currently in existence. However, fragmentation within the exposure science community acts as an obstacle for realizing the vision set fort...

Optimal path planning for a mobile robot using cuckoo search algorithm

NASA Astrophysics Data System (ADS)

Mohanty, Prases K.; Parhi, Dayal R.

2016-03-01

The shortest/optimal path planning is essential for efficient operation of autonomous vehicles. In this article, a new nature-inspired meta-heuristic algorithm has been applied for mobile robot path planning in an unknown or partially known environment populated by a variety of static obstacles. This meta-heuristic algorithm is based on the levy flight behaviour and brood parasitic behaviour of cuckoos. A new objective function has been formulated between the robots and the target and obstacles, which satisfied the conditions of obstacle avoidance and target-seeking behaviour of robots present in the terrain. Depending upon the objective function value of each nest (cuckoo) in the swarm, the robot avoids obstacles and proceeds towards the target. The smooth optimal trajectory is framed with this algorithm when the robot reaches its goal. Some simulation and experimental results are presented at the end of the paper to show the effectiveness of the proposed navigational controller.

Foliage discrimination using a rotating ladar

NASA Technical Reports Server (NTRS)

Castano, A.; Matthies, L.

2003-01-01

We present a real time algorithm that detects foliage using range from a rotating laser. Objects not classified as foliage are conservatively labeled as non-driving obstacles. In contrast to related work that uses range statistics to classify objects, we exploit the expected localities and continuities of an obstacle, in both space and time. Also, instead of attempting to find a single accurate discriminating factor for every ladar return, we hypothesize the class of some few returns and then spread the confidence (and classification) to other returns using the locality constraints. The Urbie robot is presently using this algorithm to descriminate drivable grass from obstacles during outdoor autonomous navigation tasks.

Japan Fulbright Memorial Fund Program Opens New Avenues for Effective Technology Integration into Education

NASA Astrophysics Data System (ADS)

Paoletti, Franco; Carlucci, Lisa Marie

2006-04-01

Technology is increasingly playing a major role in today's education often integrated into instruction to become one of the teacher's most effective and often indispensable tools used in the classroom. It can be said that the use of technology at the beginning of this new millennium is affecting the instructional process and it is changing some of its basic connotations. The presented work analyzes the impact of various technologies on education emphasizing the advantages provided by a successful integration, the obstacles encountered along the way, and the methodologies currently used in the process. ``Educational exchange can turn nations into people, contributing as no other form of communication can to the humanizing of international relations'' (Senator J.M. Fulbright). Technology of this modern era is providing the indispensable tool to achieve this superior level of communication overcoming historical, cultural, and language barriers. In the context of the Japan Fulbright Memorial Fund (JFMF) Teacher Program, we analyze the impact of technology on educational cross-cultural exchanges to raise awareness and interest of the scientific/educational community on the need of establishing stronger international relations promoting world peace and global prosperity.

Synthetic Vision Systems - Operational Considerations Simulation Experiment

NASA Technical Reports Server (NTRS)

Kramer, Lynda J.; Williams, Steven P.; Bailey, Randall E.; Glaab, Louis J.

2007-01-01

Synthetic vision is a computer-generated image of the external scene topography that is generated from aircraft attitude, high-precision navigation information, and data of the terrain, obstacles, cultural features, and other required flight information. A synthetic vision system (SVS) enhances this basic functionality with real-time integrity to ensure the validity of the databases, perform obstacle detection and independent navigation accuracy verification, and provide traffic surveillance. Over the last five years, NASA and its industry partners have developed and deployed SVS technologies for commercial, business, and general aviation aircraft which have been shown to provide significant improvements in terrain awareness and reductions in the potential for Controlled-Flight-Into-Terrain incidents/accidents compared to current generation cockpit technologies. It has been hypothesized that SVS displays can greatly improve the safety and operational flexibility of flight in Instrument Meteorological Conditions (IMC) to a level comparable to clear-day Visual Meteorological Conditions (VMC), regardless of actual weather conditions or time of day. An experiment was conducted to evaluate SVS and SVS-related technologies as well as the influence of where the information is provided to the pilot (e.g., on a Head-Up or Head-Down Display) for consideration in defining landing minima based upon aircraft and airport equipage. The "operational considerations" evaluated under this effort included reduced visibility, decision altitudes, and airport equipage requirements, such as approach lighting systems, for SVS-equipped aircraft. Subjective results from the present study suggest that synthetic vision imagery on both head-up and head-down displays may offer benefits in situation awareness; workload; and approach and landing performance in the visibility levels, approach lighting systems, and decision altitudes tested.

Synthetic vision systems: operational considerations simulation experiment

NASA Astrophysics Data System (ADS)

Kramer, Lynda J.; Williams, Steven P.; Bailey, Randall E.; Glaab, Louis J.

2007-04-01

Synthetic vision is a computer-generated image of the external scene topography that is generated from aircraft attitude, high-precision navigation information, and data of the terrain, obstacles, cultural features, and other required flight information. A synthetic vision system (SVS) enhances this basic functionality with real-time integrity to ensure the validity of the databases, perform obstacle detection and independent navigation accuracy verification, and provide traffic surveillance. Over the last five years, NASA and its industry partners have developed and deployed SVS technologies for commercial, business, and general aviation aircraft which have been shown to provide significant improvements in terrain awareness and reductions in the potential for Controlled-Flight-Into-Terrain incidents / accidents compared to current generation cockpit technologies. It has been hypothesized that SVS displays can greatly improve the safety and operational flexibility of flight in Instrument Meteorological Conditions (IMC) to a level comparable to clear-day Visual Meteorological Conditions (VMC), regardless of actual weather conditions or time of day. An experiment was conducted to evaluate SVS and SVS-related technologies as well as the influence of where the information is provided to the pilot (e.g., on a Head-Up or Head-Down Display) for consideration in defining landing minima based upon aircraft and airport equipage. The "operational considerations" evaluated under this effort included reduced visibility, decision altitudes, and airport equipage requirements, such as approach lighting systems, for SVS-equipped aircraft. Subjective results from the present study suggest that synthetic vision imagery on both head-up and head-down displays may offer benefits in situation awareness; workload; and approach and landing performance in the visibility levels, approach lighting systems, and decision altitudes tested.

Propagation of spiral waves pinned to circular and rectangular obstacles.

PubMed

Sutthiopad, Malee; Luengviriya, Jiraporn; Porjai, Porramain; Phantu, Metinee; Kanchanawarin, Jarin; Müller, Stefan C; Luengviriya, Chaiya

2015-05-01

We present an investigation of spiral waves pinned to circular and rectangular obstacles with different circumferences in both thin layers of the Belousov-Zhabotinsky reaction and numerical simulations with the Oregonator model. For circular objects, the area always increases with the circumference. In contrast, we varied the circumference of rectangles with equal areas by adjusting their width w and height h. For both obstacle forms, the propagating parameters (i.e., wavelength, wave period, and velocity of pinned spiral waves) increase with the circumference, regardless of the obstacle area. Despite these common features of the parameters, the forms of pinned spiral waves depend on the obstacle shapes. The structures of spiral waves pinned to circles as well as rectangles with the ratio w/h∼1 are similar to Archimedean spirals. When w/h increases, deformations of the spiral shapes are observed. For extremely thin rectangles with w/h≫1, these shapes can be constructed by employing semicircles with different radii which relate to the obstacle width and the core diameter of free spirals.

A Neural Network Approach for Building An Obstacle Detection Model by Fusion of Proximity Sensors Data

PubMed Central

Peralta, Emmanuel; Vargas, Héctor; Hermosilla, Gabriel

2018-01-01

Proximity sensors are broadly used in mobile robots for obstacle detection. The traditional calibration process of this kind of sensor could be a time-consuming task because it is usually done by identification in a manual and repetitive way. The resulting obstacles detection models are usually nonlinear functions that can be different for each proximity sensor attached to the robot. In addition, the model is highly dependent on the type of sensor (e.g., ultrasonic or infrared), on changes in light intensity, and on the properties of the obstacle such as shape, colour, and surface texture, among others. That is why in some situations it could be useful to gather all the measurements provided by different kinds of sensor in order to build a unique model that estimates the distances to the obstacles around the robot. This paper presents a novel approach to get an obstacles detection model based on the fusion of sensors data and automatic calibration by using artificial neural networks. PMID:29495338

The management of research institutions: A look at government laboratories

NASA Technical Reports Server (NTRS)

Mark, H.; Levine, A.

1984-01-01

Technology development; project management; employment patterns; research productivity; legal status of support services; functions of senior executives; the role of the sponsoring agency; research diversification; obstacles to technical innovation; organizational structures; and personnel management are addressed.

CAD/CAE-technologies application for assessment of passenger safety on railway transport in emergency

NASA Astrophysics Data System (ADS)

Antipin, D. Ya; Shorokhov, S. G.; Bondarenko, O. I.

2018-03-01

A possibility of using current software products realizing CAD/CAE-technologies for the assessment of passenger safety in emergency cases on railway transport has been analyzed. On the basis of the developed solid computer model of an anthropometric dummy, the authors carried out an analysis of possible levels of passenger injury during accident collision of a train with an obstacle.

A Monocular Vision Sensor-Based Obstacle Detection Algorithm for Autonomous Robots

PubMed Central

Lee, Tae-Jae; Yi, Dong-Hoon; Cho, Dong-Il “Dan”

2016-01-01

This paper presents a monocular vision sensor-based obstacle detection algorithm for autonomous robots. Each individual image pixel at the bottom region of interest is labeled as belonging either to an obstacle or the floor. While conventional methods depend on point tracking for geometric cues for obstacle detection, the proposed algorithm uses the inverse perspective mapping (IPM) method. This method is much more advantageous when the camera is not high off the floor, which makes point tracking near the floor difficult. Markov random field-based obstacle segmentation is then performed using the IPM results and a floor appearance model. Next, the shortest distance between the robot and the obstacle is calculated. The algorithm is tested by applying it to 70 datasets, 20 of which include nonobstacle images where considerable changes in floor appearance occur. The obstacle segmentation accuracies and the distance estimation error are quantitatively analyzed. For obstacle datasets, the segmentation precision and the average distance estimation error of the proposed method are 81.4% and 1.6 cm, respectively, whereas those for a conventional method are 57.5% and 9.9 cm, respectively. For nonobstacle datasets, the proposed method gives 0.0% false positive rates, while the conventional method gives 17.6%. PMID:26938540

Development of a program for tele-rehabilitation of COPD patients across sectors: co-innovation in a network

PubMed Central

Dinesen, Birthe; Seeman, Janne; Gustafsson, Jeppe

2011-01-01

Introduction The aim of the Telekat project is to prevent re-admissions of patients with chronic obstructive pulmonary disease (COPD) by developing a preventive program of tele-rehabilitation across sectors for COPD patients. The development of the program is based on a co-innovation process between COPD patients, relatives, healthcare professionals and representatives from private firms and universities. This paper discusses the obstacles that arise in the co-innovation process of developing an integrated technique for tele-rehabilitation of COPD patients. Theory Network and innovation theory. Methods The case study was applied. A triangulation of data collection techniques was used: documents, observations (123 hours), qualitative interviews (n=32) and action research. Findings Obstacles were identified in the network context; these obstacles included the mindset of the healthcare professionals, inter-professionals relations, views of technology as a tool and competing visions for the goals of tele-rehabilitation. Conclusion We have identified obstacles that emerge in the co-innovation process when developing a programme for tele-rehabilitation of COPD patients in an inter-organizational context. Action research has been carried out and can have helped to facilitate the co-innovation process. PMID:21637709

Computer vision techniques for rotorcraft low-altitude flight

NASA Technical Reports Server (NTRS)

Sridhar, Banavar; Cheng, Victor H. L.

1988-01-01

A description is given of research that applies techniques from computer vision to automation of rotorcraft navigation. The effort emphasizes the development of a methodology for detecting the ranges to obstacles in the region of interest based on the maximum utilization of passive sensors. The range map derived from the obstacle detection approach can be used as obstacle data for the obstacle avoidance in an automataic guidance system and as advisory display to the pilot. The lack of suitable flight imagery data, however, presents a problem in the verification of concepts for obstacle detection. This problem is being addressed by the development of an adequate flight database and by preprocessing of currently available flight imagery. Some comments are made on future work and how research in this area relates to the guidance of other autonomous vehicles.

Obstacle Detection in Indoor Environment for Visually Impaired Using Mobile Camera

NASA Astrophysics Data System (ADS)

Rahman, Samiur; Ullah, Sana; Ullah, Sehat

2018-01-01

Obstacle detection can improve the mobility as well as the safety of visually impaired people. In this paper, we present a system using mobile camera for visually impaired people. The proposed algorithm works in indoor environment and it uses a very simple technique of using few pre-stored floor images. In indoor environment all unique floor types are considered and a single image is stored for each unique floor type. These floor images are considered as reference images. The algorithm acquires an input image frame and then a region of interest is selected and is scanned for obstacle using pre-stored floor images. The algorithm compares the present frame and the next frame and compute mean square error of the two frames. If mean square error is less than a threshold value α then it means that there is no obstacle in the next frame. If mean square error is greater than α then there are two possibilities; either there is an obstacle or the floor type is changed. In order to check if the floor is changed, the algorithm computes mean square error of next frame and all stored floor types. If minimum of mean square error is less than a threshold value α then flour is changed otherwise there exist an obstacle. The proposed algorithm works in real-time and 96% accuracy has been achieved.

An Intelligent Robotic Hospital Bed for Safe Transportation of Critical Neurosurgery Patients Along Crowded Hospital Corridors.

PubMed

Wang, Chao; Savkin, Andrey V; Clout, Ray; Nguyen, Hung T

2015-09-01

We present a novel design of an intelligent robotic hospital bed, named Flexbed, with autonomous navigation ability. The robotic bed is developed for fast and safe transportation of critical neurosurgery patients without changing beds. Flexbed is more efficient and safe during the transportation process comparing to the conventional hospital beds. Flexbed is able to avoid en-route obstacles with an efficient easy-to-implement collision avoidance strategy when an obstacle is nearby and to move towards its destination at maximum speed when there is no threat of collision. We present extensive simulation results of navigation of Flexbed in the crowded hospital corridor environments with moving obstacles. Moreover, results of experiments with Flexbed in the real world scenarios are also presented and discussed.

A comparative study on managers', staffs' and clients' viewpoints about organizational and structural obstacles in family planning counseling in health-care centers in Isfahan in 2012.

PubMed

Taheri, Safoura; Ehsanpour, Soheila; Kohan, Shahnaz

2014-03-01

Organizational and structural obstacles are a group of major obstacles in achievement of appropriate family planning counseling. Detection of these obstacles from the viewpoint of managers, staffs and clients who are key members in health services providing system is a major step toward appropriate planning to modify or delete this group of obstacles. The present study was conducted with the goal of comparing managers', staffs' and clients' viewpoints about organizational and structural obstacles in family planning counseling in health-care centers in Isfahan in 2012. This is a cross-sectional one-step three-group comparative descriptive study conducted on 295 subjects including 59 managers, 110 staffs and 126 clients in medical health-care centers in Isfahan in 2012. Managers and the staffs were selected by census sampling and the clients were recruited through convenient random sampling. The date collection tool was a researcher made questionnaire, which was designed in two sections of fertility and personal characteristics and viewpoint measurement. Descriptive and inferential statistical test were used to analyze the data. The obtained results showed no significant difference between mean scores of viewpoints in three groups of managers, staffs and clients concerning organizational and structural obstacles in family planning counseling (P = 0.677). In addition, most of the managers, staffs and clients reported organizational and structural obstacles as the obstacles in the process of family planning in moderate level. The results showed the necessity of health services managers' planning to modify or delete organizational and structural obstacles especially the agreed obstacles from the viewpoint of managers, staffs and clients.

Measures for simulator evaluation of a helicopter obstacle avoidance system

NASA Technical Reports Server (NTRS)

Demaio, Joe; Sharkey, Thomas J.; Kennedy, David; Hughes, Micheal; Meade, Perry

1993-01-01

The U.S. Army Aeroflightdynamics Directorate (AFDD) has developed a high-fidelity, full-mission simulation facility for the demonstration and evaluation of advanced helicopter mission equipment. The Crew Station Research and Development Facility (CSRDF) provides the capability to conduct one- or two-crew full-mission simulations in a state-of-the-art helicopter simulator. The CSRDF provides a realistic, full field-of-regard visual environment with simulation of state-of-the-art weapons, sensors, and flight control systems. We are using the CSRDF to evaluate the ability of an obstacle avoidance system (OASYS) to support low altitude flight in cluttered terrain using night vision goggles (NVG). The OASYS uses a laser radar to locate obstacles to safe flight in the aircraft's flight path. A major concern is the detection of wires, which can be difficult to see with NVG, but other obstacles--such as trees, poles or the ground--are also a concern. The OASYS symbology is presented to the pilot on a head-up display mounted on the NVG (NVG-HUD). The NVG-HUD presents head-stabilized symbology to the pilot while allowing him to view the image intensified, out-the-window scene through the HUD. Since interference with viewing through the display is a major concern, OASYS symbology must be designed to present usable obstacle clearance information with a minimum of clutter.

Overcoming an obstacle in expanding a UMLS semantic type extent.

PubMed

Chen, Yan; Gu, Huanying; Perl, Yehoshua; Geller, James

2012-02-01

This paper strives to overcome a major problem encountered by a previous expansion methodology for discovering concepts highly likely to be missing a specific semantic type assignment in the UMLS. This methodology is the basis for an algorithm that presents the discovered concepts to a human auditor for review and possible correction. We analyzed the problem of the previous expansion methodology and discovered that it was due to an obstacle constituted by one or more concepts assigned the UMLS Semantic Network semantic type Classification. A new methodology was designed that bypasses such an obstacle without a combinatorial explosion in the number of concepts presented to the human auditor for review. The new expansion methodology with obstacle avoidance was tested with the semantic type Experimental Model of Disease and found over 500 concepts missed by the previous methodology that are in need of this semantic type assignment. Furthermore, other semantic types suffering from the same major problem were discovered, indicating that the methodology is of more general applicability. The algorithmic discovery of concepts that are likely missing a semantic type assignment is possible even in the face of obstacles, without an explosion in the number of processed concepts. Copyright © 2011 Elsevier Inc. All rights reserved.

Overcoming an Obstacle in Expanding a UMLS Semantic Type Extent

PubMed Central

Chen, Yan; Gu, Huanying; Perl, Yehoshua; Geller, James

2011-01-01

This paper strives to overcome a major problem encountered by a previous expansion methodology for discovering concepts highly likely to be missing a specific semantic type assignment in the UMLS. This methodology is the basis for an algorithm that presents the discovered concepts to a human auditor for review and possible correction. We analyzed the problem of the previous expansion methodology and discovered that it was due to an obstacle constituted by one or more concepts assigned the UMLS Semantic Network semantic type Classification. A new methodology was designed that bypasses such an obstacle without a combinatorial explosion in the number of concepts presented to the human auditor for review. The new expansion methodology with obstacle avoidance was tested with the semantic type Experimental Model of Disease and found over 500 concepts missed by the previous methodology that are in need of this semantic type assignment. Furthermore, other semantic types suffering from the same major problem were discovered, indicating that the methodology is of more general applicability. The algorithmic discovery of concepts that are likely missing a semantic type assignment is possible even in the face of obstacles, without an explosion in the number of processed concepts. PMID:21925287

Different protocols for analyzing behavior and adaptability in obstacle crossing in Parkinson's disease.

PubMed

Mollaei, Nafiseh; Bicho, Estela; Sousa, Nuno; Gago, Miguel Fernandes

2017-01-01

Imbalance and tripping over obstacles as a result of altered gait in older adults, especially in patients with Parkinson's disease (PD), are one of the most common causes of falls. During obstacle crossing, patients with PD modify their behavior in order to decrease the mechanical demands and enhance dynamic stability. Various descriptions of dynamic traits of gait that have been collected over longer periods, probably better synthesize the underlying structure and pattern of fluctuations in gait and can be more sensitive markers of aging or early neurological dysfunction and increased risk of falls. This confirmation challenges the clinimetric of different protocols and paradigms used for gait analysis up till now, in particular when analyzing obstacle crossing. The authors here present a critical review of current knowledge concerning the interplay between the cognition and gait in aging and PD, emphasizing the differences in gait behavior and adaptability while walking over different and challenging obstacle paradigms, and the implications of obstacle negotiation as a predictor of falls. Some evidence concerning the effectiveness of future rehabilitation protocols on reviving obstacle crossing behavior by trial and error relearning, taking advantage of dual-task paradigms, physical exercise, and virtual reality have been put forward in this article.

Terrestrial Micro Renewable Energy Applications of Space Technology

NASA Astrophysics Data System (ADS)

Komerath, N. M.; Komerath, P. P.

This paper explores the synergy between technologies intended for extraterrestrial in situ resource utilization and those for terrestrial mass-market micro renewable power generation systems. The case for a micro renewable energy architecture is presented. The obstacles hindering market success are summarized, along with opportunities from recent demonstrations suggesting that the public appetite for sophisticated technology worldwide may be underappreciated by technical researchers. Technical innovations from space research are summarized along with estimates of possible conversion efficiencies. It is argued that the cost-effectiveness of micro power generation must be viewed through the value of the first few watts of available power, rather than the marginal cost per kilowatt-hour of electric power from utility power grids. This leads to the finding that the actual target cost per unit power, and efficiency, are well within reach of space technology products. Hybrid systems integrating power extraction from multiple resources, and adaptable for multiple applications, can break through mass market price barriers. Recent work to develop learning resources and test beds as part of a Micro Renewable Energy Laboratory is summarized.

Sodium Hydroxide Pretreatment of Switchgrass for Ethanol Production

USDA-ARS?s Scientific Manuscript database

Lignocellulose-to-ethanol conversion is a promising technology to supplement corn-based ethanol production. However, the recalcitrant structure of lignocellulosic material is a major obstacle to the efficient conversion. To improve the enzymatic digestibility of switchgrass for the fermentable sugar...

Connection Development: Web Lessons from Westchester.

ERIC Educational Resources Information Center

Freedman, Maurice J.

1996-01-01

Committed to utilizing information technology, the Westchester Library System (New York) made the World Wide Web publicly accessible. Describes the planning, implementation, and management process; obstacles involving financing; establishing Internet connectivity; and vendor negotiations. Westchester hired a Web manager, created Internet use…

DNAseq Workflow in a Diagnostic Context and an Example of a User Friendly Implementation.

PubMed

Wolf, Beat; Kuonen, Pierre; Dandekar, Thomas; Atlan, David

2015-01-01

Over recent years next generation sequencing (NGS) technologies evolved from costly tools used by very few, to a much more accessible and economically viable technology. Through this recently gained popularity, its use-cases expanded from research environments into clinical settings. But the technical know-how and infrastructure required to analyze the data remain an obstacle for a wider adoption of this technology, especially in smaller laboratories. We present GensearchNGS, a commercial DNAseq software suite distributed by Phenosystems SA. The focus of GensearchNGS is the optimal usage of already existing infrastructure, while keeping its use simple. This is achieved through the integration of existing tools in a comprehensive software environment, as well as custom algorithms developed with the restrictions of limited infrastructures in mind. This includes the possibility to connect multiple computers to speed up computing intensive parts of the analysis such as sequence alignments. We present a typical DNAseq workflow for NGS data analysis and the approach GensearchNGS takes to implement it. The presented workflow goes from raw data quality control to the final variant report. This includes features such as gene panels and the integration of online databases, like Ensembl for annotations or Cafe Variome for variant sharing.

Urban hopper.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xavier, Patrick Gordon; Feddema, John Todd; Little, Charles Quentin

2010-03-01

Hopping robots provide the possibility of breaking the link between the size of a ground vehicle and the largest obstacle that it can overcome. For more than a decade, DARPA and Sandia National Laboratories have been developing small-scale hopping robot technology, first as part of purely hopping platforms and, more recently, as part of platforms that are capable of both wheeled and hopping locomotion. In this paper we introduce the Urban Hopper robot and summarize its capabilities. The advantages of hopping for overcoming certain obstacles are discussed. Several configurations of the Urban Hopper are described, as are intelligent capabilities ofmore » the system. Key challenges are discussed.« less

The Commercial Challenges Of Pacs

NASA Astrophysics Data System (ADS)

Vanden Brink, John A.

1984-08-01

The increasing use of digital imaging techniques create a need for improved methods of digital processing, communication and archiving. However, the commercial opportunity is dependent on the resolution of a number of issues. These issues include proof that digital processes are more cost effective than present techniques, implementation of information system support in the imaging activity, implementation of industry standards, conversion of analog images to digital formats, definition of clinical needs, the implications of the purchase decision and technology requirements. In spite of these obstacles, a market is emerging, served by new and existing companies, that may become a $500 million market (U.S.) by 1990 for equipment and supplies.

Lipid-polymer hybrid nanoparticle-mediated therapeutics delivery: advances and challenges.

PubMed

Bose, Rajendran J C; Ravikumar, Rramaswamy; Karuppagounder, Vengadeshprabu; Bennet, Devasier; Rangasamy, Sabarinathan; Thandavarayan, Rajarajan A

2017-08-01

With rapid advances in nanomedicine, lipid-polymer hybrid nanoparticles (LPHNPs) have emerged as promising nanocarriers for several biomedical applications, including therapeutics delivery and biomedical imaging. Significant research has been dedicated to biomimetic or targeting functionalization, as well as controlled and image-guided drug-release capabilities. Despite this research, the clinical translation of LPHNP-mediated therapeutics delivery has progressed incrementally. In this review, we discuss the recent advances in and challenges to the development and application of LPHNPs, present examples to demonstrate the advantages of LPHNPs in therapeutics delivery and imaging applications, and discuss the translational obstacles to LPHNP technology. Copyright © 2017. Published by Elsevier Ltd.

Robust analysis of an underwater navigational strategy in electrically heterogeneous corridors.

PubMed

Dimble, Kedar D; Ranganathan, Badri N; Keshavan, Jishnu; Humbert, J Sean

2016-08-01

Obstacles and other global stimuli provide relevant navigational cues to a weakly electric fish. In this work, robust analysis of a control strategy based on electrolocation for performing obstacle avoidance in electrically heterogeneous corridors is presented and validated. Static output feedback control is shown to achieve the desired goal of reflexive obstacle avoidance in such environments in simulation and experimentation. The proposed approach is computationally inexpensive and readily implementable on a small scale underwater vehicle, making underwater autonomous navigation feasible in real-time.

Current-day precision oncology: from cancer prevention, screening, drug development, and treatment - have we fallen short of the promise?

PubMed

Morgan, Gilberto; Aftimos, Philippe; Awada, Ahmad

2016-09-01

Precision oncology has been a strategy of prevention, screening, and treatment. Although much has been invested, have the results fallen so far short of the promise? The advancement of technology and research has opened new doors, yet a variety of pitfalls are present. This review presents the successes, failures, and opportunities of precision oncology in the current landscape. The use of targeted gene sequencing and the overwhelming results of superresponders have generated much excitement and support for precision oncology from the medical community. Despite notable successes, many challenges still pave the way of precision oncology: intratumoral heterogeneity, the need for serial biopsies, availability of treatments, target prioritization, ethical issues with germline incidental findings, medical education, clinical trial design, and costs. Precision oncology shows much potential through the use of next-generation sequencing and molecular advances, but does this potential warrant the investment? There are many obstacles on the way of this technology that should make us question if the investment (both monetary and man-hours) will live up to the promise. The review aims to not criticize this technology, but to give a realistic view of where we are, especially regarding cancer treatment and prevention.

CZTSSe: Materials and Physics Challenges

NASA Astrophysics Data System (ADS)

Gunawan, Oki

2011-03-01

Thin-film photovoltaic (PV) technologies led by CdTe and Cu(In,Ga) Se 2 (CIGS) are enjoying growing market share, due to their high performance and cost competitiveness, in the quest for renewable energy for the future. However the reliance on non-earth abundant elements tellurium and indium in these technologies presents a potential obstacle to ultimate terawatt deployment. We recently demonstrated kesterite Cu 2 ZnSn(Se,S)4 (CZTSSe) solar cells, comprised of the earth abundant metals copper, zinc and tin, with world record efficiency of 9.7%. In this talk we present a comprehensive device characterization study that pinpoints the key performance bottlenecks in these cells. We find strong buffer-absorber interface recombination and low minority carrier lifetimes that limit the open circuit voltage and a high and diverging device series resistance at lower temperature that suggests a blocking back contact that may limit the fill factor. These findings help to identify key areas for improvement for these CZTSSe cells in the pursuit of a high performance terawatt-scalable PV technology. In collaboration with Teodor K. Todorov, Aaron Barkhouse, Kejia Wang, David B. Mitzi, Supratik Guha, IBM T J Watson Research Center.

Fusion of 3D laser scanner and depth images for obstacle recognition in mobile applications

NASA Astrophysics Data System (ADS)

Budzan, Sebastian; Kasprzyk, Jerzy

2016-02-01

The problem of obstacle detection and recognition or, generally, scene mapping is one of the most investigated problems in computer vision, especially in mobile applications. In this paper a fused optical system using depth information with color images gathered from the Microsoft Kinect sensor and 3D laser range scanner data is proposed for obstacle detection and ground estimation in real-time mobile systems. The algorithm consists of feature extraction in the laser range images, processing of the depth information from the Kinect sensor, fusion of the sensor information, and classification of the data into two separate categories: road and obstacle. Exemplary results are presented and it is shown that fusion of information gathered from different sources increases the effectiveness of the obstacle detection in different scenarios, and it can be used successfully for road surface mapping.

Pigeons trade efficiency for stability in response to level of challenge during confined flight.

PubMed

Williams, C David; Biewener, Andrew A

2015-03-17

Individuals traversing challenging obstacles are faced with a decision: they can adopt traversal strategies that minimally disrupt their normal locomotion patterns or they can adopt strategies that substantially alter their gait, conferring new advantages and disadvantages. We flew pigeons (Columba livia) through an array of vertical obstacles in a flight arena, presenting them with this choice. The pigeons selected either a strategy involving only a slight pause in the normal wing beat cycle, or a wings-folded posture granting reduced efficiency but greater stability should a misjudgment lead to collision. The more stable but less efficient flight strategy was not used to traverse easy obstacles with wide gaps for passage but came to dominate the postures used as obstacle challenge increased with narrower gaps and there was a greater chance of a collision. These results indicate that birds weigh potential obstacle negotiation strategies and estimate task difficulty during locomotor pattern selection.

Pigeons trade efficiency for stability in response to level of challenge during confined flight

PubMed Central

Williams, C. David; Biewener, Andrew A.

2015-01-01

Individuals traversing challenging obstacles are faced with a decision: they can adopt traversal strategies that minimally disrupt their normal locomotion patterns or they can adopt strategies that substantially alter their gait, conferring new advantages and disadvantages. We flew pigeons (Columba livia) through an array of vertical obstacles in a flight arena, presenting them with this choice. The pigeons selected either a strategy involving only a slight pause in the normal wing beat cycle, or a wings-folded posture granting reduced efficiency but greater stability should a misjudgment lead to collision. The more stable but less efficient flight strategy was not used to traverse easy obstacles with wide gaps for passage but came to dominate the postures used as obstacle challenge increased with narrower gaps and there was a greater chance of a collision. These results indicate that birds weigh potential obstacle negotiation strategies and estimate task difficulty during locomotor pattern selection. PMID:25733863

A switching formation strategy for obstacle avoidance of a multi-robot system based on robot priority model.

PubMed

Dai, Yanyan; Kim, YoonGu; Wee, SungGil; Lee, DongHa; Lee, SukGyu

2015-05-01

This paper describes a switching formation strategy for multi-robots with velocity constraints to avoid and cross obstacles. In the strategy, a leader robot plans a safe path using the geometric obstacle avoidance control method (GOACM). By calculating new desired distances and bearing angles with the leader robot, the follower robots switch into a safe formation. With considering collision avoidance, a novel robot priority model, based on the desired distance and bearing angle between the leader and follower robots, is designed during the obstacle avoidance process. The adaptive tracking control algorithm guarantees that the trajectory and velocity tracking errors converge to zero. To demonstrate the validity of the proposed methods, simulation and experiment results present that multi-robots effectively form and switch formation avoiding obstacles without collisions. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

An intelligent rollator for mobility impaired persons, especially stroke patients.

PubMed

Hellström, Thomas; Lindahl, Olof; Bäcklund, Tomas; Karlsson, Marcus; Hohnloser, Peter; Bråndal, Anna; Hu, Xiaolei; Wester, Per

2016-07-01

An intelligent rollator (IRO) was developed that aims at obstacle detection and guidance to avoid collisions and accidental falls. The IRO is a retrofit four-wheeled rollator with an embedded computer, two solenoid brakes, rotation sensors on the wheels and IR-distance sensors. The value reported by each distance sensor was compared in the computer to a nominal distance. Deviations indicated a present obstacle and caused activation of one of the brakes in order to influence the direction of motion to avoid the obstacle. The IRO was tested by seven healthy subjects with simulated restricted and blurred sight and five stroke subjects on a standardised indoor track with obstacles. All tested subjects walked faster with intelligence deactivated. Three out of five stroke patients experienced more detected obstacles with intelligence activated. This suggests enhanced safety during walking with IRO. Further studies are required to explore the full value of the IRO.

Early Obstacle Detection and Avoidance for All to All Traffic Pattern in Wireless Sensor Networks

NASA Astrophysics Data System (ADS)

Huc, Florian; Jarry, Aubin; Leone, Pierre; Moraru, Luminita; Nikoletseas, Sotiris; Rolim, Jose

This paper deals with early obstacles recognition in wireless sensor networks under various traffic patterns. In the presence of obstacles, the efficiency of routing algorithms is increased by voluntarily avoiding some regions in the vicinity of obstacles, areas which we call dead-ends. In this paper, we first propose a fast convergent routing algorithm with proactive dead-end detection together with a formal definition and description of dead-ends. Secondly, we present a generalization of this algorithm which improves performances in all to many and all to all traffic patterns. In a third part we prove that this algorithm produces paths that are optimal up to a constant factor of 2π + 1. In a fourth part we consider the reactive version of the algorithm which is an extension of a previously known early obstacle detection algorithm. Finally we give experimental results to illustrate the efficiency of our algorithms in different scenarios.

Self Calibrated Wireless Distributed Environmental Sensory Networks

PubMed Central

Fishbain, Barak; Moreno-Centeno, Erick

2016-01-01

Recent advances in sensory and communication technologies have made Wireless Distributed Environmental Sensory Networks (WDESN) technically and economically feasible. WDESNs present an unprecedented tool for studying many environmental processes in a new way. However, the WDESNs’ calibration process is a major obstacle in them becoming the common practice. Here, we present a new, robust and efficient method for aggregating measurements acquired by an uncalibrated WDESN, and producing accurate estimates of the observed environmental variable’s true levels rendering the network as self-calibrated. The suggested method presents novelty both in group-decision-making and in environmental sensing as it offers a most valuable tool for distributed environmental monitoring data aggregation. Applying the method on an extensive real-life air-pollution dataset showed markedly more accurate results than the common practice and the state-of-the-art. PMID:27098279

[Barriers for introducing a health technology assessment organization to inform health care decision-making in the Spanish National Health System].

PubMed

Artells, Juan José; Peiró, Salvador; Meneu, Ricard

2014-01-01

To identify difficulties, obstacles and limitations to establish an organizational structure devoted to the evaluation of healthcare technologies for incorporation, maintenance or removal from the services portfolio of the Spanish National Health System (sNHS). Panel of 14 experts, structured according to processes adapted from brainstorming, nominal group, and Rand consensus method techniques. The panel proposed 77 items as potential obstacles to the establishment of an official and independent "agency" able to inform on sNHS healthcare benefits funding or selective disinvestment. These items were focused on: 1) lack of political motivation to introduce the cost-effectiveness analysis from the state and regional governments and lack of independence and transparency of the evaluation processes, 2) the tension between a decentralized health system and evaluation activities with significant scale economies, 3) technical difficulties of the evaluation processes, including their ability to influence decision making and 4) social and professional refusal to the exclusion of healthcare benefits when it is perceived as indiscriminate. Although there is a different number and type of obstacles for developing the capacity of the sNHS to include or exclude healthcare benefits based on the evaluation of their effectiveness and efficiency, experts place in the political arena (political motivation, transparency, governance) the main difficulties to advance in this field.

Road-Following Formation Control of Autonomous Ground Vehicles

NASA Technical Reports Server (NTRS)

Ono, Masahiro; Droge, Greg; Grip, Havard; Toupet, Olivier; Scrapper, Chris; Rahmani, Amir

2015-01-01

This work presents a novel cooperative path planning for formation keeping robots traversing along a road with obstacles and possible narrow passages. A unique challenge in this problem is a requirement for spatial and temporal coordination between vehicles while ensuring collision and obstacle avoidance.

Symbiotic Navigation in Multi-Robot Systems with Remote Obstacle Knowledge Sharing

PubMed Central

Ravankar, Abhijeet; Ravankar, Ankit A.; Kobayashi, Yukinori; Emaru, Takanori

2017-01-01

Large scale operational areas often require multiple service robots for coverage and task parallelism. In such scenarios, each robot keeps its individual map of the environment and serves specific areas of the map at different times. We propose a knowledge sharing mechanism for multiple robots in which one robot can inform other robots about the changes in map, like path blockage, or new static obstacles, encountered at specific areas of the map. This symbiotic information sharing allows the robots to update remote areas of the map without having to explicitly navigate those areas, and plan efficient paths. A node representation of paths is presented for seamless sharing of blocked path information. The transience of obstacles is modeled to track obstacles which might have been removed. A lazy information update scheme is presented in which only relevant information affecting the current task is updated for efficiency. The advantages of the proposed method for path planning are discussed against traditional method with experimental results in both simulation and real environments. PMID:28678193

Smart walking stick for blind people: an application of 3D printer

NASA Astrophysics Data System (ADS)

Ikbal, Md. Allama; Rahman, Faidur; Ali, Md. Ripon; Kabir, M. Hasnat; Furukawa, Hidemitsu

2017-04-01

A prototype of the smart walking stick has been designed and characterized for the people who are visually impaired. In this study, it was considered that the proposed system will alert visuallyimpaired people over the obstacles which are in front of blind people as well as the obstacles of the street such as a manhole, when the blind people are walking in the street. The proposed system was designed in two stages, i.e. hardware and software which makes the system as a complete prototype. Three ultrasonic sonar sensors were used to detect in front obstacle and street surface obstacle such as manhole. Basically the sensor transmits an electromagnetic wave which travels toward the obstacle and back to the sensor receiver. The distance between the sensor and the obstacle is calculated from the received signal. The calculated distance value is compared with the pre-defined value and determines whether the obstacle is present or not. The 3D CAD software was used to design the sensor holder. An Up-Mini 3D printer was used to print the sensor holders which were mounted on the walking stick. Therefore, the sensors were fixed in the right position. Another sensor was used for the detecting the water on the walking street. The performance for detecting the obstacles and water indicate the merit of smart walking stick.

Characterizing Laminar Flame Interactions with Turbulent Fluidic Jets and Solid Obstacles for Turbulence Induction

NASA Astrophysics Data System (ADS)

Gerdts, Stephen; Chambers, Jessica; Ahmed, Kareem

2016-11-01

A detonation engine's fundamental design concept focuses on enhancing the Deflagration to Detonation Transition (DDT), the process through which subsonic flames accelerate to form a spontaneous detonation wave. Flame acceleration is driven by turbulent interactions that expand the reaction zone and induce mixing of products and reactants. Turbulence in a duct can be generated using solid obstructions, fluidic obstacles, duct angle changes, and wall skin friction. Solid obstacles have been previously explored and offer repeatable turbulence induction at the cost of pressure losses and additional system weight. Fluidic jet obstacles are a novel technique that provide advantages such as the ability to be throttled, allowing for active control of combustion modes. The scope of the present work is to expand the experimental database of varying parameters such as main flow and jet equivalence ratios, fluidic momentum ratios, and solid obstacle blockage ratios. Schlieren flow visualization and particle image velocimetry (PIV) are employed to investigate turbulent flame dynamics throughout the interaction. Optimum conditions that lead to flame acceleration for both solid and fluidic obstacles will be determined. American Chemical Society.

Improved obstacle avoidance and navigation for an autonomous ground vehicle

NASA Astrophysics Data System (ADS)

Giri, Binod; Cho, Hyunsu; Williams, Benjamin C.; Tann, Hokchhay; Shakya, Bicky; Bharam, Vishal; Ahlgren, David J.

2015-01-01

This paper presents improvements made to the intelligence algorithms employed on Q, an autonomous ground vehicle, for the 2014 Intelligent Ground Vehicle Competition (IGVC). In 2012, the IGVC committee combined the formerly separate autonomous and navigation challenges into a single AUT-NAV challenge. In this new challenge, the vehicle is required to navigate through a grassy obstacle course and stay within the course boundaries (a lane of two white painted lines) that guide it toward a given GPS waypoint. Once the vehicle reaches this waypoint, it enters an open course where it is required to navigate to another GPS waypoint while avoiding obstacles. After reaching the final waypoint, the vehicle is required to traverse another obstacle course before completing the run. Q uses modular parallel software architecture in which image processing, navigation, and sensor control algorithms run concurrently. A tuned navigation algorithm allows Q to smoothly maneuver through obstacle fields. For the 2014 competition, most revisions occurred in the vision system, which detects white lines and informs the navigation component. Barrel obstacles of various colors presented a new challenge for image processing: the previous color plane extraction algorithm would not suffice. To overcome this difficulty, laser range sensor data were overlaid on visual data. Q also participates in the Joint Architecture for Unmanned Systems (JAUS) challenge at IGVC. For 2014, significant updates were implemented: the JAUS component accepted a greater variety of messages and showed better compliance to the JAUS technical standard. With these improvements, Q secured second place in the JAUS competition.

The flow across a street canyon of variable width—Part 2:. Scalar dispersion from a street level line source

NASA Astrophysics Data System (ADS)

Simoëns, Serge; Wallace, James M.

As described in Part 1 [Simoëns et al., 2007. The flow across a street canyon of variable width—Part 1: kinematic description. Atmospheric Environment 41, 9002-9017] measurements have been made of the velocity field around and within the canyon formed by two obstacles placed on the wall of a turbulent boundary layer. Here in Part 2 measurements of the scalar dispersion of smoke released from a two-dimensional slot in the wall perpendicular to the mean flow and located parallel to and midway between these two square obstacles are presented. The Reynolds number of the boundary layer at the slot location without the obstacles in place was Rθ≈980. Statistical properties of the concentration field and the scalar fluxes in the streamwise plane are reported here for canyon openings that have been chosen based on characteristics of the kinematic description. These opening widths, expressed as multiples of the obstacle height, are 1 h, 4 h and 8 h. The mean concentration field revealed that the much of the scalar is trapped on the leeward side of the upstream obstacle before some of it escapes the canyon and is entrained on the roof of the upstream obstacle. It then is spread downstream by the turbulence in the wake of this obstacle. Surprisingly, the root mean square (rms) concentration field reveals that high concentration fluctuations exist in a zone where velocity field turbulence is very low. Measured streamwise scalar fluxes were found to be negative above the obstacles, whereas they are mainly positive between the obstacles. The measured wall normal scalar fluxes have an inverse behavior. Within the canyon, the scalar fluxes are greatest in the region between the large primary vortex, evident in the kinematic field, and the secondary vortex located in the corner of the leeward side of the upstream obstacle. In the flow above the obstacle roofs the wake of the upstream obstacle seems to dominate the scalar transport. Between the obstacles in and above the canyon, the existence of intermittent and intense events appear to prevent the modelling of these fluxes with a simple mean concentration gradient model.

Law, policy and the use of non-physicians in family planning service delivery.

PubMed

Paxman, J M

1979-04-01

A great deal of attention is being devoted to the use of nonphysicians to provide such fertility control services as contraception, sterilization, and abortion. Legal obstacles exist, however, which must be overcome before the role of nonphysicians can be expanded. Such obstacles include medical practice statutes, nursing and midwifery legislation, and laws and regulations directly related to such fertility control measures as the provision of contraceptions and the performance of sterilizations. On the other hand, the following 3 main approaches have been used to permit increased participation of nonphysicians: delegation of tasks by physicians, liberal interpretation of existing laws, and authorization. Thus, the important elements in expanding the roles of nonphysicians are 1) authorization; 2) training; 3) qualification; 4) supervision; and 5) opportunities for referrals to physicians. The ultimate role of paramedicals will depend upon the continued simplification of technology, the results of research on the quality of care which they can provide, the attitudes of the medical profession, and the elimination of the legal ambiguities and obstacles which exist.

The NASA Software Research Infusion Initiative: Successful Technology Transfer for Software Assurance

NASA Technical Reports Server (NTRS)

Hinchey, Michael G.; Pressburger, Thomas; Markosian, Lawrence; Feather, Martin S.

2006-01-01

New processes, methods and tools are constantly appearing in the field of software engineering. Many of these augur great potential in improving software development processes, resulting in higher quality software with greater levels of assurance. However, there are a number of obstacles that impede their infusion into software development practices. These are the recurring obstacles common to many forms of research. Practitioners cannot readily identify the emerging techniques that may most benefit them, and cannot afford to risk time and effort in evaluating and experimenting with them while there is still uncertainty about whether they will have payoff in this particular context. Similarly, researchers cannot readily identify those practitioners whose problems would be amenable to their techniques and lack the feedback from practical applications necessary to help them to evolve their techniques to make them more likely to be successful. This paper describes an ongoing effort conducted by a software engineering research infusion team, and the NASA Research Infusion Initiative, established by NASA s Software Engineering Initiative, to overcome these obstacles.

Enabling UAV Navigation with Sensor and Environmental Uncertainty in Cluttered and GPS-Denied Environments

PubMed Central

Vanegas, Fernando; Gonzalez, Felipe

2016-01-01

Unmanned Aerial Vehicles (UAV) can navigate with low risk in obstacle-free environments using ground control stations that plan a series of GPS waypoints as a path to follow. This GPS waypoint navigation does however become dangerous in environments where the GPS signal is faulty or is only present in some places and when the airspace is filled with obstacles. UAV navigation then becomes challenging because the UAV uses other sensors, which in turn generate uncertainty about its localisation and motion systems, especially if the UAV is a low cost platform. Additional uncertainty affects the mission when the UAV goal location is only partially known and can only be discovered by exploring and detecting a target. This navigation problem is established in this research as a Partially-Observable Markov Decision Process (POMDP), so as to produce a policy that maps a set of motion commands to belief states and observations. The policy is calculated and updated on-line while flying with a newly-developed system for UAV Uncertainty-Based Navigation (UBNAV), to navigate in cluttered and GPS-denied environments using observations and executing motion commands instead of waypoints. Experimental results in both simulation and real flight tests show that the UAV finds a path on-line to a region where it can explore and detect a target without colliding with obstacles. UBNAV provides a new method and an enabling technology for scientists to implement and test UAV navigation missions with uncertainty where targets must be detected using on-line POMDP in real flight scenarios. PMID:27171096

Enabling UAV Navigation with Sensor and Environmental Uncertainty in Cluttered and GPS-Denied Environments.

PubMed

Vanegas, Fernando; Gonzalez, Felipe

2016-05-10

Unmanned Aerial Vehicles (UAV) can navigate with low risk in obstacle-free environments using ground control stations that plan a series of GPS waypoints as a path to follow. This GPS waypoint navigation does however become dangerous in environments where the GPS signal is faulty or is only present in some places and when the airspace is filled with obstacles. UAV navigation then becomes challenging because the UAV uses other sensors, which in turn generate uncertainty about its localisation and motion systems, especially if the UAV is a low cost platform. Additional uncertainty affects the mission when the UAV goal location is only partially known and can only be discovered by exploring and detecting a target. This navigation problem is established in this research as a Partially-Observable Markov Decision Process (POMDP), so as to produce a policy that maps a set of motion commands to belief states and observations. The policy is calculated and updated on-line while flying with a newly-developed system for UAV Uncertainty-Based Navigation (UBNAV), to navigate in cluttered and GPS-denied environments using observations and executing motion commands instead of waypoints. Experimental results in both simulation and real flight tests show that the UAV finds a path on-line to a region where it can explore and detect a target without colliding with obstacles. UBNAV provides a new method and an enabling technology for scientists to implement and test UAV navigation missions with uncertainty where targets must be detected using on-line POMDP in real flight scenarios.

Renewable Energy and Climate Change

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chum, H. L.

2012-01-01

The Intergovernmental Panel on Climate Change issued the Special Report on Renewable Energy Sources and Climate Change Mitigation (SRREN) at http://srren.ipcc-wg3.de/ (May 2011 electronic version; printed form ISBN 978-1-107-60710-1, 2012). More than 130 scientists contributed to the report.* The SRREN assessed existing literature on the future potential of renewable energy for the mitigation of climate change within a portfolio of mitigation options including energy conservation and efficiency, fossil fuel switching, RE, nuclear and carbon capture and storage (CCS). It covers the six most important renewable energy technologies - bioenergy, direct solar, geothermal, hydropower, ocean and wind, as well as theirmore » integration into present and future energy systems. It also takes into consideration the environmental and social consequences associated with these technologies, the cost and strategies to overcome technical as well as non-technical obstacles to their application and diffusion.« less

Cheap or Robust? The practical realization of self-driving wheelchair technology.

PubMed

Burhanpurkar, Maya; Labbe, Mathieu; Guan, Charlie; Michaud, Francois; Kelly, Jonathan

2017-07-01

To date, self-driving experimental wheelchair technologies have been either inexpensive or robust, but not both. Yet, in order to achieve real-world acceptance, both qualities are fundamentally essential. We present a unique approach to achieve inexpensive and robust autonomous and semi-autonomous assistive navigation for existing fielded wheelchairs, of which there are approximately 5 million units in Canada and United States alone. Our prototype wheelchair platform is capable of localization and mapping, as well as robust obstacle avoidance, using only a commodity RGB-D sensor and wheel odometry. As a specific example of the navigation capabilities, we focus on the single most common navigation problem: the traversal of narrow doorways in arbitrary environments. The software we have developed is generalizable to corridor following, desk docking, and other navigation tasks that are either extremely difficult or impossible for people with upper-body mobility impairments.

Comparative Analysis of the Molecular Adjuvants and Their Binding Efficiency with CR1.

PubMed

Saranya, B; Saxena, Shweta; Saravanan, K M; Shakila, H

2016-03-01

There are so many obstacles in developing a vaccine or vaccine technology for diseases like cancer and human immunodeficiency virus infection. While developing vaccines that target specific infection, molecular adjuvants are indispensable. These molecular adjuvants act as a vaccine delivery vehicle to the immune system to increase the effectiveness of the specific antigens. In the present work, a computational study has been done on molecular adjuvants like IgGFc, GMCSF and C3d to find out how efficiently they are binding to CR1. Sequence, structure and mutational analysis are performed on the molecular adjuvants to understand the features important for their binding with the receptor. Results obtained from our study indicate that the adjuvant IgGFc complexed with the receptor CR1 has the best binding efficiency, which can be used further to develop better vaccine technologies.

Global Collaborative STEM Education

NASA Astrophysics Data System (ADS)

Meabh Kelly, Susan; Smith, Walter

2016-04-01

Global Collaborative STEM Education, as the name suggests, simultaneously supports two sets of knowledge and skills. The first set is STEM -- science, technology, engineering and math. The other set of content knowledge and skills is that of global collaboration. Successful global partnerships require awareness of one's own culture, the biases embedded within that culture, as well as developing awareness of the collaborators' culture. Workforce skills fostered include open-mindedness, perseverance when faced with obstacles, and resourceful use of technological "bridges" to facilitate and sustain communication. In respect for the 2016 GIFT Workshop focus, Global Collaborative STEM Education projects dedicated to astronomy research will be presented. The projects represent different benchmarks within the Global Collaborative STEM Education continuum, culminating in an astronomy research experience that fully reflects how the global STEM workforce collaborates. To facilitate wider engagement in Global Collaborative STEM Education, project summaries, classroom resources and contact information for established international collaborative astronomy research projects will be disseminated.

Different protocols for analyzing behavior and adaptability in obstacle crossing in Parkinson’s disease

PubMed Central

Mollaei, Nafiseh; Bicho, Estela; Sousa, Nuno; Gago, Miguel Fernandes

2017-01-01

Imbalance and tripping over obstacles as a result of altered gait in older adults, especially in patients with Parkinson’s disease (PD), are one of the most common causes of falls. During obstacle crossing, patients with PD modify their behavior in order to decrease the mechanical demands and enhance dynamic stability. Various descriptions of dynamic traits of gait that have been collected over longer periods, probably better synthesize the underlying structure and pattern of fluctuations in gait and can be more sensitive markers of aging or early neurological dysfunction and increased risk of falls. This confirmation challenges the clinimetric of different protocols and paradigms used for gait analysis up till now, in particular when analyzing obstacle crossing. The authors here present a critical review of current knowledge concerning the interplay between the cognition and gait in aging and PD, emphasizing the differences in gait behavior and adaptability while walking over different and challenging obstacle paradigms, and the implications of obstacle negotiation as a predictor of falls. Some evidence concerning the effectiveness of future rehabilitation protocols on reviving obstacle crossing behavior by trial and error relearning, taking advantage of dual-task paradigms, physical exercise, and virtual reality have been put forward in this article. PMID:29158667

[Obstacles perceived by nurses for evidence-based practice: a qualitative study].

PubMed

Sánchez-García, Inmaculada; López-Medina, Isabel M; Pancorbo-Hidalgo, Pedro L

2013-01-01

To examine the obstacles perceived by nurses to implement an evidence-based clinical practice. A qualitative study through semi-structured interviews conducted in 2010-2011 including 11 nurses purposively selected from public hospitals and community centres in Jaén and Córdoba (Spain). A content analysis was performed, using Miles and Huberman as a reference and comprising the following steps: data reduction, data presentation, and data conclusion/verification. Data saturation was reached in these categories (obstacles). The obstacles perceived by nurses to introduce an evidence-based clinical practice (EBCP) were grouped into 3 major categories: obstacles related with professionals (routine-based practice, unwilling and stagnant attitudes, and lack of training in EBCP), obstacles related to the social context (reluctance from other professionals and from patients or families), and obstacles related to the organization (obsolete cultures that do not promote innovation in nursing care). This study highlights the persistence of various factors that hinder the use of research findings in clinical practice. The results underline the need to change the culture of healthcare organizations, to motivate professionals, and to break some of the resistance attitudes that hinder the implementation of evidence-based practice. Copyright © 2012 Elsevier España, S.L. All rights reserved.

Energy Technology Training Conference Proceedings (Atlanta, Georgia, October 27-29, 1976).

ERIC Educational Resources Information Center

Oak Ridge Associated Universities, TN.

Conference goals included identifying projected technical manpower needs and skill mix requirements, potential obstacles to developing an adequate technical education base, and stimulating education, industry, and labor cooperation in technical program development and federal interagency coordination and cooperation. Findings of the conference…

Assessment of Intergenerational Communication and Relationships

ERIC Educational Resources Information Center

Strom, Robert D.; Strom, Paris S.

2015-01-01

The revolution in communication technology has resulted in more age-segregated conversation among adolescents. In a similar way, older adults have increased online conversations with their peers. This article explores some obstacles that prevent the intergenerational connections needed for mutual understanding and care. Several research emphases…

University for Masses.

ERIC Educational Resources Information Center

Sharma, Motilal

Education, a basic need, is the foundation of developing countries such as Bangladesh. Ignorance and illiteracy are obstacles to growth and technological progress. Formal schooling must be supplemented with nonformal education, distance education, and out-of-school education for workers who want to continue their studies. Universities must develop…

Communication, Education and Empowerment. Manchester Monographs 33.

ERIC Educational Resources Information Center

Carmen, Raff

When considering what type of communication is required for development, the conventional answer of diffusion of technological innovation for modernization and growth is inadequate. Daniel Lerner and Everett Rogers describe traditional people as the greatest obstacle to development. Paulo Freire perceives communication as an instrument for…

Utilization of sonar technology and microcontroller towards reducing aviation hazards during ground handling of aircraft

NASA Astrophysics Data System (ADS)

Khanam, Mosammat Samia; Biswas, Debasish; Rashid, Mohsina; Salam, Md Abdus

2017-12-01

Safety is one of the most important factors in the field of aviation. Though, modern aircraft are equipped with many instruments/devices to enhance the flight safety but it is seen that accidents/incidents are never reduced to zero. Analysis of the statistical summary of Commercial Jet Airplane accidents highlights that fatal accidents that occurred worldwide from 2006 through 2015 is 11% during taxing, loading/unloading, parking and towing. Human, handling the aircrafts is one of the most important links in aircraft maintenance and hence play a significant role in aviation safety. Effort has been made in this paper to obviate human error in aviation and outline an affordable system that monitors the uneven surface &obstacles for safe "towing in" and "towing out" of an aircraft by the ground crew. The system revolves around implementation of sonar technology by microcontroller. Ultrasonic sensors can be installed on aircraft wings and tail section to identify the uneven surface &obstacles ahead and provide early warning to the maintenance ground crews.

Electronic prescribing in ambulatory practice: promises, pitfalls, and potential solutions.

PubMed

Papshev, D; Peterson, A M

2001-07-01

To examine advantages of and obstacles to electronic prescribing in the ambulatory care environment. MEDLINE and International Pharmaceutical Abstract searches were conducted for the period from January 1980 to September 2000. Key words were electronic prescribing, computerized physician order entry, prior authorization, drug utilization review, and consumer satisfaction. In September 2000, a public search engine (www.google.com) was used to find additional technical information. In addition, pertinent articles were cross-referenced to identify other resources. Articles, symposia proceedings, and organizational position statements published in the United States on electronic prescribing and automation in healthcare are cited. Electronic prescribing can eliminate the time gap between point of care and point of service, reduce medication errors, improve quality of care, and increase patient satisfaction. Considerable funding requirements, segmentation of healthcare markets, lack of technology standardization, providers' resistance to change, and regulatory indecisiveness create boundaries to the widespread use of automated prescribing. The potential solutions include establishing a standardizing warehouse or a router and gaining stakeholder support in implementation of the technology. Electronic prescribing can provide immense benefits to healthcare providers, patients, and managed care. Resolution of several obstacles that limit feasibility of this technology will determine its future.

Development of PEM fuel cell technology at international fuel cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wheeler, D.J.

1996-04-01

The PEM technology has not developed to the level of phosphoric acid fuel cells. Several factors have held the technology development back such as high membrane cost, sensitivity of PEM fuel cells to low level of carbon monoxide impurities, the requirement to maintain full humidification of the cell, and the need to pressurize the fuel cell in order to achieve the performance targets. International Fuel Cells has identified a hydrogen fueled PEM fuel cell concept that leverages recent research advances to overcome major economic and technical obstacles.

A methodology for the generation of the 2-D map from unknown navigation environment by traveling a short distance

NASA Technical Reports Server (NTRS)

Bourbakis, N.; Sarkar, D.

1994-01-01

A technique for generation of a 2-D space map by traveling a short distance is described. The space to be mapped can be classified as: (1) space without obstacles, (2) space with stationary obstacles, and (3) space with moving obstacles. This paper presents the methodology used to generate a 2-D map of an unknown navigation space. The ability to minimize the redundancy during traveling and maximize the confidence function for generation of the map are advantages of this technique.

Mobility aid for the blind

NASA Technical Reports Server (NTRS)

1982-01-01

A project to develop an effective mobility aid for blind pedestrians which acquires consecutive images of the scenes before a moving pedestrian, which locates and identifies the pedestrian's path and potential obstacles in the path, which presents path and obstacle information to the pedestrian, and which operates in real-time is discussed. The mobility aid has three principal components: an image acquisition system, an image interpretation system, and an information presentation system. The image acquisition system consists of a miniature, solid-state TV camera which transforms the scene before the blind pedestrian into an image which can be received by the image interpretation system. The image interpretation system is implemented on a microprocessor which has been programmed to execute real-time feature extraction and scene analysis algorithms for locating and identifying the pedestrian's path and potential obstacles. Identity and location information is presented to the pedestrian by means of tactile coding and machine-generated speech.

Stokes paradox in electronic Fermi liquids

NASA Astrophysics Data System (ADS)

Lucas, Andrew

2017-03-01

The Stokes paradox is the statement that in a viscous two-dimensional fluid, the "linear response" problem of fluid flow around an obstacle is ill posed. We present a simple consequence of this paradox in the hydrodynamic regime of a Fermi liquid of electrons in two-dimensional metals. Using hydrodynamics and kinetic theory, we estimate the contribution of a single cylindrical obstacle to the global electrical resistance of a material, within linear response. Momentum relaxation, present in any realistic electron liquid, resolves the classical paradox. Nonetheless, this paradox imprints itself in the resistance, which can be parametrically larger than predicted by Ohmic transport theory. We find a remarkably rich set of behaviors, depending on whether or not the quasiparticle dynamics in the Fermi liquid should be treated as diffusive, hydrodynamic, or ballistic on the length scale of the obstacle. We argue that all three types of behavior are observable in present day experiments.

Mission-based guidance system design for autonomous UAVs

NASA Astrophysics Data System (ADS)

Moon, Jongki

The advantages of UAVs in the aviation arena have led to extensive research activities on autonomous technology of UAVs to achieve specific mission objectives. This thesis mainly focuses on the development of a mission-based guidance system. Among various missions expected for future needs, autonomous formation flight (AFF) and obstacle avoidance within safe operation limits are investigated. In the design of an adaptive guidance system for AFF, the leader information except position is assumed to be unknown to a follower. Thus, the only measured information related to the leader is the line-of-sight (LOS) range and angle. Adding an adaptive element with neural networks into the guidance system provides a capability to effectively handle leader's velocity changes. Therefore, this method can be applied to the AFF control systems that use a passive sensing method. In this thesis, an adaptive velocity command guidance system and an adaptive acceleration command guidance system are developed and presented. Since relative degrees of the LOS range and angle are different depending on the outputs from the guidance system, the architecture of the guidance system changes accordingly. Simulations and flight tests are performed using the Georgia Tech UAV helicopter, the GTMax, to evaluate the proposed guidance systems. The simulation results show that the neural network (NN) based adaptive element can improve the tracking performance by effectively compensating for the effect of unknown dynamics. It has also been shown that the combination of an adaptive velocity command guidance system and the existing GTMax autopilot controller performs better than the combination of an adaptive acceleration command guidance system and the GTMax autopilot controller. The successful flight evaluation using an adaptive velocity command guidance system clearly shows that the adaptive guidance control system is a promising solution for autonomous formation flight of UAVs. In addition, an integrated approach is proposed to resolve the conflict between aggressive maneuvering needed for obstacle avoidance and the constrained maneuvering needed for envelope protection. A time-optimal problem with obstacle and envelope constraints is used for an integrated approach for obstacle avoidance and envelope protection. The Nonlinear trajectory generator (NTG) is used as a real-time optimization solver. The computational complexity arising from the obstacle constraints is reduced by converting the obstacle constraints into a safe waypoint constraint along with an implicit requirement that the horizontal velocity during the avoidance maneuver must be nonnegative. The issue of when to initiate a time-optimal avoidance maneuver is addressed by including a requirement that the vehicle must maintain its original flight path to the maximum extent possible. The simulation evaluations are preformed for the nominal case, the unsafe avoidance solution case, the multiple safe waypoint case, and the unidentified obstacle size case. Artificial values for the load factor limit and the longitudinal flap angle limit are imposed as safe operational boundaries. Also, simulation results for different limit values and different initial flight speed are compared. Simulation results using a nonlinear model of a rotary wing UAV demonstrate the feasibility of the proposed approach for obstacle avoidance with envelope protection.

Professional development in statistics, technology, and cognitively demanding tasks: classroom implementation and obstacles

NASA Astrophysics Data System (ADS)

Foley, Gregory D.; Bakr Khoshaim, Heba; Alsaeed, Maha; Nihan Er, S.

2012-03-01

Attending professional development programmes can support teachers in applying new strategies for teaching mathematics and statistics. This study investigated (a) the extent to which the participants in a professional development programme subsequently used the techniques they had learned when teaching mathematics and statistics and (b) the obstacles they encountered in enacting cognitively demanding instructional tasks in their classrooms. The programme created an intellectual learning community among the participants and helped them gain confidence as teachers of statistics, and the students of participating teachers became actively engaged in deep mathematical thinking. The participants indicated, however, that time, availability of resources and students' prior achievement critically affected the implementation of cognitively demanding instructional activities.

Does physical exercise improve obstacle negotiation in the elderly? A systematic review.

PubMed

Guadagnin, Eliane C; da Rocha, Emmanuel S; Duysens, Jacques; Carpes, Felipe P

2016-01-01

Physical exercise improves walking in the elderly but much less is known about its effect on more challenged gait, such as obstacle negotiation. We conducted a systematic review to discuss the effects of regular physical exercise on kinematics and kinetics of obstacle negotiation in the elderly. A comprehensive literature search revealed 859 citations for review, whereof 206 studies entered the full-text analysis. After application of inclusion and exclusion criteria, 13 studies were included in this systematic review. Most of them presented a reasonable quality (average 0.68) but none of them reached the level of a randomized control trial. Interventions were heterogeneous, with training periods lasting from 5 days to 10 months. Studies assessed obstacle negotiation basically considering 3 types of testing paradigm, namely a walkway with either a single obstacle crossing, or with multiple obstacles, or else a treadmill with an obstacle avoidance task under time pressure. In general, longer training programs had better results and very short ones were not effective. A weekly frequency of 2-3 times was the most common among the studies showing positive effects. Regardless of exercises types performed, most of them were effective and so far, there is no consensus about the best exercise for improving obstacle negotiation. A lack of studies on this topic still is evident. Including a record of fall score can further help in deciding which programs are to be preferred. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The Vital Program: Transforming ICT Professional Development

ERIC Educational Resources Information Center

Bradshaw, Pete; Twining, Peter; Walsh, Christopher S.

2012-01-01

Developing a model for effective large-scale continuous professional development (CPD) for teachers remains a significant obstacle for many governments worldwide. This article describes the development and evolution of Vital--a CPD program designed to enhance the teaching of information communication technology in state-funded primary and…

Managing Curriculum Change and "Ontological Uncertainty" in Tertiary Education

ERIC Educational Resources Information Center

Keesing-Styles, Linda; Nash, Simon; Ayres, Robert

2014-01-01

Curriculum reform at institutional level is a challenging endeavour. Those charged with leading this process will encounter both enthusiasm and multiple obstacles to teacher engagement including the particularly complex issue of confronting existing teacher identities. At Unitec Institute of Technology (Unitec), the "Living Curriculum"…

Chemistry Students' Challenges in Using MBL's in Science Laboratories.

ERIC Educational Resources Information Center

Atar, Hakan Yavuz

Understanding students' challenges about using microcomputer based laboratories (MBLs) would provide important data in understanding the appropriateness of using MBLs in high school chemistry laboratories. Identifying students' concerns about this technology will in part help educators identify the obstacles to science learning when using this…

Exact Solution of the Two-Dimensional Problem on an Impact Ideal-Liquid Jet

NASA Astrophysics Data System (ADS)

Belik, V. D.

2018-05-01

The two-dimensional problem on the collision of a potential ideal-liquid jet, outflowing from a reservoir through a nozzle, with an infinite plane obstacle was considered for the case where the distance between the nozzle exit section and the obstacle is finite. An exact solution of this problem has been found using methods of the complex-variable function theory. Simple analytical expressions for the complex velocity of the liquid, its flow rate, and the force of action of the jet on the obstacle have been obtained. The velocity distributions of the liquid at the nozzle exit section, in the region of spreading of the jet, and at the obstacle have been constructed for different distances between the nozzle exit section and the obstacle. Analytical expressions for the thickness of the boundary layer and the Nusselt number at the point of stagnation of the jet have been obtained. A number of distributions of the local friction coefficient and the Nusselt number of the indicated jet are presented.

Obstacle Detection Algorithms for Aircraft Navigation: Performance Characterization of Obstacle Detection Algorithms for Aircraft Navigation

NASA Technical Reports Server (NTRS)

Kasturi, Rangachar; Camps, Octavia; Coraor, Lee

2000-01-01

The research reported here is a part of NASA's Synthetic Vision System (SVS) project for the development of a High Speed Civil Transport Aircraft (HSCT). One of the components of the SVS is a module for detection of potential obstacles in the aircraft's flight path by analyzing the images captured by an on-board camera in real-time. Design of such a module includes the selection and characterization of robust, reliable, and fast techniques and their implementation for execution in real-time. This report describes the results of our research in realizing such a design. It is organized into three parts. Part I. Data modeling and camera characterization; Part II. Algorithms for detecting airborne obstacles; and Part III. Real time implementation of obstacle detection algorithms on the Datacube MaxPCI architecture. A list of publications resulting from this grant as well as a list of relevant publications resulting from prior NASA grants on this topic are presented.

Nonlinear water waves generated by impulsive motion of submerged obstacle

NASA Astrophysics Data System (ADS)

Makarenko, N.; Kostikov, V.

2012-04-01

The fully nonlinear problem on generation of unsteady water waves by impulsively moving obstacle is studied analytically. The method involves the reduction of basic Euler equations to the integral-differential system for the wave elevation together with normal and tangential fluid velocities at the free surface. Exact model equations are derived in explicit form when the isolated obstacle is presented by totally submerged circular- or elliptic cylinder. Small-time asymptotic solution is constructed for the cylinder which starts moving with constant acceleration from rest. It is demonstrated that the leading-order solution terms describe several wave regimes such as the formation of non-stationary splash jets by vertical rising or vertical submersion of the obstacle, as well as the generation of diverging waves by horizontal- and combined motion of the obstacle under free surface. This work was supported by RFBR (grant No 10-01-00447) and by Research Program of the Russian Government (grant No 11.G34.31.0035).

Prevention 0f Unwanted Free-Declaration of Static Obstacles in Probability Occupancy Grids

NASA Astrophysics Data System (ADS)

Krause, Stefan; Scholz, M.; Hohmann, R.

2017-10-01

Obstacle detection and avoidance are major research fields in unmanned aviation. Map based obstacle detection approaches often use discrete world representations such as probabilistic grid maps to fuse incremental environment data from different views or sensors to build a comprehensive representation. The integration of continuous measurements into a discrete representation can result in rounding errors which, in turn, leads to differences between the artificial model and real environment. The cause of these deviations is a low spatial resolution of the world representation comparison to the used sensor data. Differences between artificial representations which are used for path planning or obstacle avoidance and the real world can lead to unexpected behavior up to collisions with unmapped obstacles. This paper presents three approaches to the treatment of errors that can occur during the integration of continuous laser measurement in the discrete probabilistic grid. Further, the quality of the error prevention and the processing performance are compared with real sensor data.

Real-time obstacle avoidance using harmonic potential functions

NASA Technical Reports Server (NTRS)

Kim, Jin-Oh; Khosla, Pradeep K.

1992-01-01

This paper presents a new formulation of the artificial potential approach to the obstacle avoidance problem for a mobile robot or a manipulator in a known environment. Previous formulations of artificial potentials for obstacle avoidance have exhibited local minima in a cluttered environment. To build an artificial potential field, harmonic functions that completely eliminate local minima even for a cluttered environment are used. The panel method is employed to represent arbitrarily shaped obstacles and to derive the potential over the whole space. Based on this potential function, an elegant control strategy is proposed for the real-time control of a robot. The harmonic potential, the panel method, and the control strategy are tested with a bar-shaped mobile robot and a three-degree-of-freedom planar redundant manipulator.

A Numerical Analysis of the Resistance and Stiffness of the Timber and Concrete Composite Beam

NASA Astrophysics Data System (ADS)

Szumigała, Ewa; Szumigała, Maciej; Polus, Łukasz

2015-03-01

The article presents the results of a numerical analysis of the load capacity and stiffness of the composite timber and concrete beam. Timber and concrete structures are relatively new, they have not been thoroughly tested and they are rarely used because of technological constraints. One of the obstacles to using them is difficulty with finding a method which would allow successful cooperation between concrete and timber, which has been proposed by the authors of the present article. The modern idea of sustainable construction design requires the use of new more environmentally-friendly solutions. Wood as an ecological material is easily accessible, less energy-consuming, and under certain conditions more corrosion-resistant than steel. The analysis presented in the article showed that cooperation between a wooden beam and a concrete slab on profiled steel sheeting is possible. The analysed composite beam has a greater load capacity and stiffness than the wooden beam.

Experience with abstract notation one

NASA Technical Reports Server (NTRS)

Harvey, James D.; Weaver, Alfred C.

1990-01-01

The development of computer science has produced a vast number of machine architectures, programming languages, and compiler technologies. The cross product of these three characteristics defines the spectrum of previous and present data representation methodologies. With regard to computer networks, the uniqueness of these methodologies presents an obstacle when disparate host environments are to be interconnected. Interoperability within a heterogeneous network relies upon the establishment of data representation commonality. The International Standards Organization (ISO) is currently developing the abstract syntax notation one standard (ASN.1) and the basic encoding rules standard (BER) that collectively address this problem. When used within the presentation layer of the open systems interconnection reference model, these two standards provide the data representation commonality required to facilitate interoperability. The details of a compiler that was built to automate the use of ASN.1 and BER are described. From this experience, insights into both standards are given and potential problems relating to this development effort are discussed.

Reflections on the present and future of upper limb prostheses.

PubMed

Farina, Dario; Amsüss, Sebastian

2016-01-01

Despite progress in research and media attention on active upper limb prostheses, presently the most common commercial upper limb prosthetic devices are not fundamentally different from solutions offered almost one century ago. Limited information transfer for both control and sensory-motor integration and challenges in socket technology have been major obstacles. By analysing the present state-of-the-art and academic achievements, we provide our opinion on the future of upper limb prostheses. We believe that surgical procedures for muscle reinnervation and osseointegration will become increasingly clinically relevant; muscle electrical signals will remain the main clinical means for prosthetic control; and chronic electrode implants, first in muscles (control), then in nerves (sensory feedback), will become viable clinical solutions. After decades of suspended clinically relevant progress, it is foreseeable that a new generation of upper limb prostheses will enter the market in the near future based on such advances, thereby offering substantial clinical benefit for patients.

Energy dissipation by submarine obstacles during landslide impact on reservoir - potentially avoiding catastrophic dam collapse

NASA Astrophysics Data System (ADS)

Kafle, Jeevan; Kattel, Parameshwari; Mergili, Martin; Fischer, Jan-Thomas; Tuladhar, Bhadra Man; Pudasaini, Shiva P.

2017-04-01

Dense geophysical mass flows such as landslides, debris flows and debris avalanches may generate super tsunami waves as they impact water bodies such as the sea, hydraulic reservoirs or mountain lakes. Here, we apply a comprehensive and general two-phase, physical-mathematical mass flow model (Pudasaini, 2012) that consists of non-linear and hyperbolic-parabolic partial differential equations for mass and momentum balances, and present novel, high-resolution simulation results for two-phase flows, as a mixture of solid grains and viscous fluid, impacting fluid reservoirs with obstacles. The simulations demonstrate that due to the presence of different obstacles in the water body, the intense flow-obstacle-interaction dramatically reduces the flow momentum resulting in the rapid energy dissipation around the obstacles. With the increase of obstacle height overtopping decreases but, the deflection and capturing (holding) of solid mass increases. In addition, the submarine solid mass is captured by the multiple obstacles and the moving mass decreases both in amount and speed as each obstacle causes the flow to deflect into two streams and also captures a portion of it. This results in distinct tsunami and submarine flow dynamics with multiple surface water and submarine debris waves. This novel approach can be implemented in open source GIS modelling framework r.avaflow, and be applied in hazard mitigation, prevention and relevant engineering or environmental tasks. This might be in particular for process chains, such as debris impacts in lakes and subsequent overtopping. So, as the complex flow-obstacle-interactions strongly and simultaneously dissipate huge energy at impact such installations potentially avoid great threat against the integrity of the dam. References: Pudasaini, S. P. (2012): A general two-phase debris flow model. J. Geophys. Res. 117, F03010, doi: 10.1029/ 2011JF002186.

Healthy young adults implement distinctive avoidance strategies while walking and circumventing virtual human vs. non-human obstacles in a virtual environment.

PubMed

Souza Silva, Wagner; Aravind, Gayatri; Sangani, Samir; Lamontagne, Anouk

2018-03-01

This study examines how three types of obstacles (cylinder, virtual human and virtual human with footstep sounds) affect circumvention strategies of healthy young adults. Sixteen participants aged 25.2 ± 2.5 years (mean ± 1SD) were tested while walking overground and viewing a virtual room through a helmet mounted display. As participants walked towards a stationary target in the far space, they avoided an obstacle (cylinder or virtual human) approaching either from the right (+40°), left (-40°) or head-on (0°). Obstacle avoidance strategies were characterized using the position and orientation of the head. Repeated mixed model analysis showed smaller minimal distances (p = 0.007) while avoiding virtual humans as compared to cylinders. Footstep sounds added to virtual humans did not modify (p = 0.2) minimal distances compared to when no sound was provided. Onset times of avoidance strategies were similar across conditions (p = 0.06). Results indicate that the nature of the obstacle (human-like vs. non-human object) matters and can modify avoidance strategies. Smaller obstacle clearances in response to virtual humans may reflect the use of a less conservative avoidance strategy, due to a resemblance of obstacles to pedestrians and a recall of strategies used in daily locomotion. The lack of influence of footstep sounds supports the fact that obstacle avoidance primarily relies on visual cues and the principle of 'inverse effectiveness' whereby multisensory neurons' response to multimodal stimuli becomes weaker when the unimodal sensory stimulus (vision) is strong. Present findings should be taken into consideration to optimize the ecological validity of VR-based obstacle avoidance paradigms used in research and rehabilitation. Copyright © 2018 Elsevier B.V. All rights reserved.

A Motion Planning Approach to Automatic Obstacle Avoidance during Concentric Tube Robot Teleoperation

PubMed Central

Torres, Luis G.; Kuntz, Alan; Gilbert, Hunter B.; Swaney, Philip J.; Hendrick, Richard J.; Webster, Robert J.; Alterovitz, Ron

2015-01-01

Concentric tube robots are thin, tentacle-like devices that can move along curved paths and can potentially enable new, less invasive surgical procedures. Safe and effective operation of this type of robot requires that the robot’s shaft avoid sensitive anatomical structures (e.g., critical vessels and organs) while the surgeon teleoperates the robot’s tip. However, the robot’s unintuitive kinematics makes it difficult for a human user to manually ensure obstacle avoidance along the entire tentacle-like shape of the robot’s shaft. We present a motion planning approach for concentric tube robot teleoperation that enables the robot to interactively maneuver its tip to points selected by a user while automatically avoiding obstacles along its shaft. We achieve automatic collision avoidance by precomputing a roadmap of collision-free robot configurations based on a description of the anatomical obstacles, which are attainable via volumetric medical imaging. We also mitigate the effects of kinematic modeling error in reaching the goal positions by adjusting motions based on robot tip position sensing. We evaluate our motion planner on a teleoperated concentric tube robot and demonstrate its obstacle avoidance and accuracy in environments with tubular obstacles. PMID:26413381

A Motion Planning Approach to Automatic Obstacle Avoidance during Concentric Tube Robot Teleoperation.

PubMed

Torres, Luis G; Kuntz, Alan; Gilbert, Hunter B; Swaney, Philip J; Hendrick, Richard J; Webster, Robert J; Alterovitz, Ron

2015-05-01

Concentric tube robots are thin, tentacle-like devices that can move along curved paths and can potentially enable new, less invasive surgical procedures. Safe and effective operation of this type of robot requires that the robot's shaft avoid sensitive anatomical structures (e.g., critical vessels and organs) while the surgeon teleoperates the robot's tip. However, the robot's unintuitive kinematics makes it difficult for a human user to manually ensure obstacle avoidance along the entire tentacle-like shape of the robot's shaft. We present a motion planning approach for concentric tube robot teleoperation that enables the robot to interactively maneuver its tip to points selected by a user while automatically avoiding obstacles along its shaft. We achieve automatic collision avoidance by precomputing a roadmap of collision-free robot configurations based on a description of the anatomical obstacles, which are attainable via volumetric medical imaging. We also mitigate the effects of kinematic modeling error in reaching the goal positions by adjusting motions based on robot tip position sensing. We evaluate our motion planner on a teleoperated concentric tube robot and demonstrate its obstacle avoidance and accuracy in environments with tubular obstacles.

Considering the Role and Nature of the Scientist: The Case of Darwin and Evolution

ERIC Educational Resources Information Center

Aydin, Serap Öz

2015-01-01

For many students, preconceived notions about Darwin are among the most significant obstacles in learning about the theory of evolution by natural selection. I present an activity designed to eliminate this obstacle and encourage empathizing with Darwin, utilizing the history-of-science approach. Through the activity, students' negative thoughts…

Planning Paths Through Singularities in the Center of Mass Space

NASA Technical Reports Server (NTRS)

Doggett, William R.; Messner, William C.; Juang, Jer-Nan

1998-01-01

The center of mass space is a convenient space for planning motions that minimize reaction forces at the robot's base or optimize the stability of a mechanism. A unique problem associated with path planning in the center of mass space is the potential existence of multiple center of mass images for a single Cartesian obstacle, since a single center of mass location can correspond to multiple robot joint configurations. The existence of multiple images results in a need to either maintain multiple center of mass obstacle maps or to update obstacle locations when the robot passes through a singularity, such as when it moves from an elbow-up to an elbow-down configuration. To illustrate the concepts presented in this paper, a path is planned for an example task requiring motion through multiple center of mass space maps. The object of the path planning algorithm is to locate the bang- bang acceleration profile that minimizes the robot's base reactions in the presence of a single Cartesian obstacle. To simplify the presentation, only non-redundant robots are considered and joint non-linearities are neglected.

A Preliminary Study of the Obstacles to, the Status of and Potential for Education for the Promotion of Disarmament. Seminar on the Obstacles to Disarmament and the Ways of Overcoming Them (3-7 April 1978).

ERIC Educational Resources Information Center

Reardon, Betty

The booklet assesses the present status of education for the promotion of disarmament in various grade levels and learning environments throughout the world. It also identifies and recommends ways to make disarmament education more effective. Disarmament is interpreted as the process leading from the present system of armed nation states to an…

Advancements in Binder Systems for Solid Freeform Fabrication

NASA Technical Reports Server (NTRS)

Cooper, Ken; Munafo, Paul (Technical Monitor)

2002-01-01

Paper will present recent developments in advanced material binder systems for solid freeform fabrication (SFF) technologies. The advantage of SFF is the capability to custom fabricate complex geometries directly from computer aided design data in layer- by-layer fashion, eliminated the need for traditional fixturing and tooling. Binders allow for the low temperature processing of 'green' structural materials, either metal, ceramic or composite, in traditional rapid prototyping machines. The greatest obstacle comes when green parts must then go through a sintering or burnout process to remove the binders and fully densify the parent material, without damaging or distorting the original part geometry. Critical issues and up-to-date assessments will be delivered on various material systems.

Future of human mitochondrial DNA editing technologies.

PubMed

Verechshagina, N; Nikitchina, N; Yamada, Y; Harashima, Н; Tanaka, M; Orishchenko, K; Mazunin, I

2018-05-15

ATP and other metabolites, which are necessary for the development, maintenance, and functioning of bodily cells are all synthesized in the mitochondria. Multiple copies of the genome, present within the mitochondria, together with its maternal inheritance, determine the clinical manifestation and spreading of mutations in mitochondrial DNA (mtDNA). The main obstacle in the way of thorough understanding of mitochondrial biology and the development of gene therapy methods for mitochondrial diseases is the absence of systems that allow to directly change mtDNA sequence. Here, we discuss existing methods of manipulating the level of mtDNA heteroplasmy, as well as the latest systems, that could be used in the future as tools for human mitochondrial genome editing.

A proposed UAV for indoor patient care.

PubMed

Todd, Catherine; Watfa, Mohamed; El Mouden, Yassine; Sahir, Sana; Ali, Afrah; Niavarani, Ali; Lutfi, Aoun; Copiaco, Abigail; Agarwal, Vaibhavi; Afsari, Kiyan; Johnathon, Chris; Okafor, Onyeka; Ayad, Marina

2015-09-10

Indoor flight, obstacle avoidance and client-server communication of an Unmanned Aerial Vehicle (UAV) raises several unique research challenges. This paper examines current methods and associated technologies adapted within the literature toward autonomous UAV flight, for consideration in a proposed system for indoor healthcare administration with a quadcopter. We introduce Healthbuddy, a unique research initiative towards overcoming challenges associated with indoor navigation, collision detection and avoidance, stability, wireless drone-server communications and automated decision support for patient care in a GPS-denied environment. To address the identified research deficits, a drone-based solution is presented. The solution is preliminary as we develop and refine the suggested algorithms and hardware system to achieve the research objectives.

A Health Collaborative Network Focus on Self-care Processes in Personal Assistant Practice

NASA Astrophysics Data System (ADS)

de La Fuente, Ma Victoria; Ros, Lorenzo

Public health is oriented to the management of an adequate health atmosphere which acts directly on health, as well as health education work and the supervision of environmental health threats. The work presented in this paper aims to reduce inequality, and give disabled people the tools to be integrated more effectively, reducing social exclusion, removing obstacles and barriers, and facilitating mobility and the use of technology. The work is planned to design a special healthcare collaborative network as the best solution for addressing the needs of the disabled self-care and health care community through the creation and implementation of an interconnected, electronic information infrastructure and adoption of open data standards.

Stroke Telemedicine

PubMed Central

Demaerschalk, Bart M.; Miley, Madeline L.; Kiernan, Terri-Ellen J.; Bobrow, Bentley J.; Corday, Doren A.; Wellik, Kay E.; Aguilar, Maria I.; Ingall, Timothy J.; Dodick, David W.; Brazdys, Karina; Koch, Tiffany C.; Ward, Michael P.; Richemont, Phillip C.

2009-01-01

Stroke telemedicine is a consultative modality that facilitates care of patients with acute stroke at underserviced hospitals by specialists at stroke centers. The design and implementation of a hub-and-spoke telestroke network are complex. This review describes the technology that makes stroke telemedicine possible, the members that should be included in a telestroke team, the hub-and-spoke characteristics of a telestroke network, and the format of a typical consultation. Common obstacles to the practice of telestroke medicine are explored, such as medicolegal, economic, and market issues. An example of a state-based telestroke network is thoroughly described, and established international telestroke networks are presented and compared. The opportunities for future advances in telestroke practice, research, and education are considered. PMID:19121244

TRAINING OLDER WORKERS FOR TECHNOLOGY-BASED EMPLOYMENT.

PubMed

Lee, Chin Chin; Czaja, Sara J; Sharit, Joseph

2009-01-01

An increasingly aging workforce and advances in technology are changing work environments and structures. The continued employability of older adults, particularly those of lower socioeconomic status (SES), requires them to participate in training programs to ensure their competence in today's workplace. Focus groups with 37 unemployed adults (51-76 years old) were conducted to gather information about barriers and obstacles for returning to work, training needs and formats, work experiences, and perceptions of the characteristics of an ideal job. Overall, results indicated that participants experienced age discrimination and lack of technology skills. They also expressed a desire to receive additional training on technology and a preference for classroom training.

Intelligence and Technology. Joint Force Quarterly, Issue 46, 3rd Quarter 2007

DTIC Science & Technology

2007-01-01

pioneering work of B.F. Skinner overcame this obstacle by embracing the notion of the “black box.” At the practical level, one does not need to see...possibilities here is the pioneering adaptation of the discipline of movement analysis described by Brenda Connors.19 In contrast to traditional profil- ing...unfamiliarity with the local geography and demography by arming them with informa- tion technology solutions, providing each Applying Law Enforcement

Hydrogen Fuel Cell Analysis: Lessons Learned from Stationary Power Generation Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scott E. Grasman; John W. Sheffield; Fatih Dogan

2010-04-30

This study considered opportunities for hydrogen in stationary applications in order to make recommendations related to RD&D strategies that incorporate lessons learned and best practices from relevant national and international stationary power efforts, as well as cost and environmental modeling of pathways. The study analyzed the different strategies utilized in power generation systems and identified the different challenges and opportunities for producing and using hydrogen as an energy carrier. Specific objectives included both a synopsis/critical analysis of lessons learned from previous stationary power programs and recommendations for a strategy for hydrogen infrastructure deployment. This strategy incorporates all hydrogen pathways andmore » a combination of distributed power generating stations, and provides an overview of stationary power markets, benefits of hydrogen-based stationary power systems, and competitive and technological challenges. The motivation for this project was to identify the lessons learned from prior stationary power programs, including the most significant obstacles, how these obstacles have been approached, outcomes of the programs, and how this information can be used by the Hydrogen, Fuel Cells & Infrastructure Technologies Program to meet program objectives primarily related to hydrogen pathway technologies (production, storage, and delivery) and implementation of fuel cell technologies for distributed stationary power. In addition, the lessons learned address environmental and safety concerns, including codes and standards, and education of key stakeholders.« less

Assessing the ground vibrations produced by a heavy vehicle traversing a traffic obstacle.

PubMed

Ducarne, Loïc; Ainalis, Daniel; Kouroussis, Georges

2018-01-15

Despite advancements in alternative transport networks, road transport remains the dominant mode in many modern and developing countries. The ground-borne motions produced by the passage of a heavy vehicle over a geometric obstacle (e.g. speed hump, train tracks) pose a fundamental problem in transport annoyance in urban areas. In order to predict the ground vibrations generated by the passage of a heavy vehicle over a geometric obstacle, a two-step numerical model is developed. The first step involves simulating the dynamic loads generated by the heavy vehicle using a multibody approach, which includes the tyre-obstacle-ground interaction. The second step involves the simulation of the ground wave propagation using a three dimensional finite element model. The simulation is able to be decoupled due to the large difference in stiffness between the vehicle's tyres and the road. First, the two-step model is validated using an experimental case study available in the literature. A sensitivity analysis is then presented, examining the influence of various factors on the generated ground vibrations. Factors investigated include obstacle shape, obstacle dimensions, vehicle speed, and tyre stiffness. The developed model can be used as a tool in the early planning stages to predict the ground vibrations generated by the passage of a heavy vehicle over an obstacle in urban areas. Copyright © 2017 Elsevier B.V. All rights reserved.

Sheaths: A Comparison of Magnetospheric, ICME, and Heliospheric Sheaths

NASA Technical Reports Server (NTRS)

Sibeck, D. G.; Richardson, J. D.; Liu, W.

2007-01-01

When a supersonic flow encounters an obstacles, shocks form to divert the flow around the obstacle. The region between the shock and the obstacle is the sheath, where the supersonic flow is compressed, heated, decelerated, and deflected. Supersonic flows, obstacles, and thus sheaths are observed on many scales throughout the Universe. We compare three examples seen in the heliosphere, illustrating the interaction of the solar wind with obstacles of three very different scales lengths. Magnetosheaths form behind planetary bow shocks on scales ranging from tens to 100 planetary radii. ICME sheath form behind shocks driven by solar disturbances on scale lengths of a few to tens of AU. The heliosheath forms behind the termination shock due to the obstacle presented by the interstellar medium on scale lengths of tens to a hundred AU. Despite this range in scales some common features have been observed. Magnetic holes, possibly due to mirror mode waves, have been observed in all three of these sheaths. Plasma depletion layers are observed in planetary and ICME sheaths. Other features observed in some sheaths are wave activity (ion cyclotron, plasma), energetic particles, transmission of Alfven waves/shocks, tangential discontinuities turbulence behind quasi-parallel shocks, standing slow mode waves, and reconnection on the obstacle boundary. We compare these sheath regions, discussing similarities and differences and how these may relate to the scale lengths of these regions.

Adolescents' Conscious Processes of Developing Regulation: Learning to Appraise Challenges

ERIC Educational Resources Information Center

Larson, Reed W.

2011-01-01

To understand regulation and agency, it important to consider the nature of the regulatory challenges that adolescents must deal with. These include emotional, motivation, interpersonal, and other obstacles and problems. In this chapter, the author discusses the challenges reported by youth working on arts, technology, and social justice projects…

Augmenting Classroom Practices with QR Codes

ERIC Educational Resources Information Center

Thorne, Tristan

2016-01-01

The use of mobile devices in the language classroom can help accomplish innumerable learning objectives, yet many teachers regard smartphones and tablets as obstacles to lesson goals. However, as portable technology continues to infiltrate classroom boundaries, it is becoming increasingly clear that educators should find ways to take advantage of…

Professional Development in Statistics, Technology, and Cognitively Demanding Tasks: Classroom Implementation and Obstacles

ERIC Educational Resources Information Center

Foley, Gregory D.; Khoshaim, Heba Bakr; Alsaeed, Maha; Er, S. Nihan

2012-01-01

Attending professional development programmes can support teachers in applying new strategies for teaching mathematics and statistics. This study investigated (a) the extent to which the participants in a professional development programme subsequently used the techniques they had learned when teaching mathematics and statistics and (b) the…

Leveraging Educational Technology to Overcome Social Obstacles to Help Seeking

ERIC Educational Resources Information Center

Howley, Iris

2015-01-01

This dissertation provides initial empirical evidence for Expectancy Value Theory for Help Sources and generates design recommendations for online courses based on the newfound understanding between theory and student behavior. (Abstract shortened by UMI.). [The dissertation citations contained here are published with the permission of ProQuest…

Advanced Biomimetic Implants Based on Nanostructured Coatings Synthesized by Pulsed Laser Technologies

NASA Astrophysics Data System (ADS)

Mihailescu, Ion N.; Ristoscu, Carmen; Bigi, Adriana; Mayer, Isaac

Calcium phosphates (CaPs) are alternative substitutes for human bones and so primary candidates for the manufacture of medical implants. Unfortunately, they do not withstand stress in bulk. To overcome this obstacle, a solution was developed to cover metallic implants with functional biomimetic layers.

The Computer in the Living Room.

ERIC Educational Resources Information Center

Schlafly, Hubert J.

Disputing some opinions that technological advancement will make our country into the world of "1984," the author suggests benefits that can come from community antenna television (CATV). He outlines the potential of the two-way cable; describes the current status of the operation; discusses obstacles such as competition, regulation, equipment,…

Blurring the Lines: A Blended Learning Model in a Graduate Public Administration Program

ERIC Educational Resources Information Center

Schuhmann, Robert A.; Skopek, Tracy A.

2009-01-01

Despite technological and pedagogical improvements, obstacles continue in certain areas of distance education, including a lack of interaction among students and instructors and associated feelings of disconnectedness from the campus community. This article explores the study results of a blended learning, distance education graduate program…

Against the Odds: Professional Development and Innovation under Less-than-Ideal Conditions.

ERIC Educational Resources Information Center

Hunter, Beverly

2001-01-01

Reports accomplishments of teachers who overcame obstacles to create innovative learning opportunities using electronic technologies. Summarizes findings of a research project conducted by Department of Defense Education Activity schools with teachers who worked in small teams to plan, implement, and evaluate innovative practices and used Vanguard…

Doing Business in the New Technology: Problems for College and University Counsel.

ERIC Educational Resources Information Center

Toohey, Daniel W.; Gray, Todd D.

1984-01-01

Regulatory changes regarding public broadcasting and telecommunications facilities on college and university campuses allowing remunerative use of the facilities, and potential obstacles to remunerative use posed by state statutes, are discussed from legal and tax perspectives. The potential for double taxation is examined. (MSE)

Understanding the Learning Process in SMEs

ERIC Educational Resources Information Center

Carr, James; Gannon-Leary, Pat

2007-01-01

A major obstacle to the diffusion of management development learning technologies from Higher Education Institutions to Small and Medium-sized Enterprises (SMEs) is a lack of understanding about how SME learners learn. This article examines the nature of learning in SMEs and considers the incidence of informal support for informal learning.…

Obstacles to Industrial Implementation of Scanning Systems

Treesearch

Anders Astrom; Olog Broman; John Graffman; Anders Gronlund; Armas Jappinene; Jari Luostarinen; Jan Nystrom; Daniel L. Schmoldt

1998-01-01

Initially the group discussed what is meant by scanning systems. An operational definition was adopted to consider scanning system in the current context to be nontraditional scanning. Where, traditional scanning is defined as scanning that has been industrially operational and relatively common for several years-a mature technology. For example,...

Obstacle Recognition Based on Machine Learning for On-Chip LiDAR Sensors in a Cyber-Physical System

PubMed Central

Beruvides, Gerardo

2017-01-01

Collision avoidance is an important feature in advanced driver-assistance systems, aimed at providing correct, timely and reliable warnings before an imminent collision (with objects, vehicles, pedestrians, etc.). The obstacle recognition library is designed and implemented to address the design and evaluation of obstacle detection in a transportation cyber-physical system. The library is integrated into a co-simulation framework that is supported on the interaction between SCANeR software and Matlab/Simulink. From the best of the authors’ knowledge, two main contributions are reported in this paper. Firstly, the modelling and simulation of virtual on-chip light detection and ranging sensors in a cyber-physical system, for traffic scenarios, is presented. The cyber-physical system is designed and implemented in SCANeR. Secondly, three specific artificial intelligence-based methods for obstacle recognition libraries are also designed and applied using a sensory information database provided by SCANeR. The computational library has three methods for obstacle detection: a multi-layer perceptron neural network, a self-organization map and a support vector machine. Finally, a comparison among these methods under different weather conditions is presented, with very promising results in terms of accuracy. The best results are achieved using the multi-layer perceptron in sunny and foggy conditions, the support vector machine in rainy conditions and the self-organized map in snowy conditions. PMID:28906450

Obstacle Recognition Based on Machine Learning for On-Chip LiDAR Sensors in a Cyber-Physical System.

PubMed

Castaño, Fernando; Beruvides, Gerardo; Haber, Rodolfo E; Artuñedo, Antonio

2017-09-14

Collision avoidance is an important feature in advanced driver-assistance systems, aimed at providing correct, timely and reliable warnings before an imminent collision (with objects, vehicles, pedestrians, etc.). The obstacle recognition library is designed and implemented to address the design and evaluation of obstacle detection in a transportation cyber-physical system. The library is integrated into a co-simulation framework that is supported on the interaction between SCANeR software and Matlab/Simulink. From the best of the authors' knowledge, two main contributions are reported in this paper. Firstly, the modelling and simulation of virtual on-chip light detection and ranging sensors in a cyber-physical system, for traffic scenarios, is presented. The cyber-physical system is designed and implemented in SCANeR. Secondly, three specific artificial intelligence-based methods for obstacle recognition libraries are also designed and applied using a sensory information database provided by SCANeR. The computational library has three methods for obstacle detection: a multi-layer perceptron neural network, a self-organization map and a support vector machine. Finally, a comparison among these methods under different weather conditions is presented, with very promising results in terms of accuracy. The best results are achieved using the multi-layer perceptron in sunny and foggy conditions, the support vector machine in rainy conditions and the self-organized map in snowy conditions.

Using the socio-ecological framework to determine breastfeeding obstacles in a low-income population in Tijuana, Mexico: healthcare services.

PubMed

Bueno-Gutierrez, Diana; Chantry, Caroline

2015-03-01

In Mexico, breastfeeding rates are one of the lowest of Latin America, with 14.4% of infants under 6 months being exclusively breastfed. Previous studies indicate that lack of support from healthcare services is a serious obstacle to breastfeeding mothers in Mexico. Our objective was to identify the main obstacles to breastfeeding presented by the healthcare services in a low-income population in Tijuana, Mexico. We used a socio-ecological framework to determine factors affecting breastfeeding practices. In four low-income communities in Tijuana we conducted focus groups and interviews with mothers, fathers, grandparents, and key informants. Interview notes and focus group transcripts were then studied in-depth independently by three researchers. The primary analytic technique was constant comparison. One hundred twenty-nine subjects participated in this study: six focus groups (n=53) and 51 interviews among mothers, fathers, and grandparents, as well as 25 interviews among key informants. Main healthcare service obstacles to breastfeeding were erroneous information, lack of training and supervision, negative attitudes, miscommunication between healthcare providers (HCPs) and patients, detrimental medical practices such as giving free formula at hospitals, and the conflict of interest between the infant food industry and the HCPs. This study showed that women in low-income communities in Tijuana face multiple obstacles to breastfeeding presented by healthcare services. In order to increase breastfeeding rates, institutional and structural changes are required.

Do characteristics of a stationary obstacle lead to adjustments in obstacle stepping strategies?

PubMed

Worden, Timothy A; De Jong, Audrey F; Vallis, Lori Ann

2016-01-01

Navigating cluttered and complex environments increases the risk of falling. To decrease this risk, it is important to understand the influence of obstacle visual cues on stepping parameters, however the specific obstacle characteristics that have the greatest influence on avoidance strategies is still under debate. The purpose of the current work is to provide further insight on the relationship between obstacle appearance in the environment and modulation of stepping parameters. Healthy young adults (N=8) first stepped over an obstacle with one visible top edge ("floating"; 8 trials) followed by trials where experimenters randomly altered the location of a ground reference object to one of 7 different positions (8 trials per location), which ranged from 6cm in front of, directly under, or up to 6cm behind the floating obstacle (at 2cm intervals). Mean take-off and landing distance as well as minimum foot clearance values were unchanged across different positions of the ground reference object; a consistent stepping trajectory was observed for all experimental conditions. Contrary to our hypotheses, results of this study indicate that ground based visual cues are not essential for the planning of stepping and clearance strategies. The simultaneous presentation of both floating and ground based objects may have provided critical information that lead to the adoption of a consistent strategy for clearing the top edge of the obstacle. The invariant foot placement observed here may be an appropriate stepping strategy for young adults, however this may not be the case across the lifespan or in special populations. Copyright © 2015 Elsevier B.V. All rights reserved.

Nursing care in a high-technological environment: Experiences of critical care nurses.

PubMed

Tunlind, Adam; Granström, John; Engström, Åsa

2015-04-01

Management of technical equipment, such as ventilators, infusion pumps, monitors and dialysis, makes health care in an intensive care setting more complex. Technology can be defined as items, machinery and equipment that are connected to knowledge and management to maximise efficiency. Technology is not only the equipment itself, but also the knowledge of how to use it and the ability to convert it into nursing care. The aim of this study is to describe critical care nurses' experience of performing nursing care in a high technology healthcare environment. Qualitative, personal interviews were conducted during 2012 with eight critical care nurses in the northern part of Sweden. Interview transcripts were analysed using qualitative content analysis. Three themes with six categories emerged. The technology was described as a security that could facilitate nursing care, but also one that could sometimes present obstacles. The importance of using the clinical gaze was highlighted. Nursing care in a high technological environment must be seen as multi-faceted when it comes to how it affects CCNs' experience. The advanced care conducted in an ICU could not function without high-tech equipment, nor could care operate without skilled interpersonal interaction and maintenance of basal nursing. That technology is seen as a major tool and simultaneously as a barrier to patient-centred care. Copyright © 2014 Elsevier Ltd. All rights reserved.

A cloud-based production system for information and service integration: an internet of things case study on waste electronics

NASA Astrophysics Data System (ADS)

Wang, Xi Vincent; Wang, Lihui

2017-08-01

Cloud computing is the new enabling technology that offers centralised computing, flexible data storage and scalable services. In the manufacturing context, it is possible to utilise the Cloud technology to integrate and provide industrial resources and capabilities in terms of Cloud services. In this paper, a function block-based integration mechanism is developed to connect various types of production resources. A Cloud-based architecture is also deployed to offer a service pool which maintains these resources as production services. The proposed system provides a flexible and integrated information environment for the Cloud-based production system. As a specific type of manufacturing, Waste Electrical and Electronic Equipment (WEEE) remanufacturing experiences difficulties in system integration, information exchange and resource management. In this research, WEEE is selected as the example of Internet of Things to demonstrate how the obstacles and bottlenecks are overcome with the help of Cloud-based informatics approach. In the case studies, the WEEE recycle/recovery capabilities are also integrated and deployed as flexible Cloud services. Supporting mechanisms and technologies are presented and evaluated towards the end of the paper.

Unlocking the Power of Big Data at the National Institutes of Health.

PubMed

Coakley, Meghan F; Leerkes, Maarten R; Barnett, Jason; Gabrielian, Andrei E; Noble, Karlynn; Weber, M Nick; Huyen, Yentram

2013-09-01

The era of "big data" presents immense opportunities for scientific discovery and technological progress, with the potential to have enormous impact on research and development in the public sector. In order to capitalize on these benefits, there are significant challenges to overcome in data analytics. The National Institute of Allergy and Infectious Diseases held a symposium entitled "Data Science: Unlocking the Power of Big Data" to create a forum for big data experts to present and share some of the creative and innovative methods to gleaning valuable knowledge from an overwhelming flood of biological data. A significant investment in infrastructure and tool development, along with more and better-trained data scientists, may facilitate methods for assimilation of data and machine learning, to overcome obstacles such as data security, data cleaning, and data integration.

Unlocking the Power of Big Data at the National Institutes of Health

PubMed Central

Coakley, Meghan F.; Leerkes, Maarten R.; Barnett, Jason; Gabrielian, Andrei E.; Noble, Karlynn; Weber, M. Nick

2013-01-01

Abstract The era of “big data” presents immense opportunities for scientific discovery and technological progress, with the potential to have enormous impact on research and development in the public sector. In order to capitalize on these benefits, there are significant challenges to overcome in data analytics. The National Institute of Allergy and Infectious Diseases held a symposium entitled “Data Science: Unlocking the Power of Big Data” to create a forum for big data experts to present and share some of the creative and innovative methods to gleaning valuable knowledge from an overwhelming flood of biological data. A significant investment in infrastructure and tool development, along with more and better-trained data scientists, may facilitate methods for assimilation of data and machine learning, to overcome obstacles such as data security, data cleaning, and data integration. PMID:27442200

Improvements in cloning efficiencies may be possible by increasing uniformity in recipient oocytes and donor cells.

PubMed

Miyoshi, Kazuchika; Rzucidlo, S Jacek; Pratt, Scott L; Stice, Steven L

2003-04-01

The low efficiency of somatic cell cloning is the major obstacle to widespread use of this technology. Incomplete nuclear reprogramming following the transfer of donor nuclei into recipient oocytes has been implicated as a primary reason for the low efficiency of the cloning procedure. The mechanisms and factors that affect the progression of the nuclear reprogramming process have not been completely elucidated, but the identification of these factors and their subsequent manipulation would increase cloning efficiency. At present, many groups are studying donor nucleus reprogramming. Here, we present an approach in which the efficiency of producing viable offspring is improved by selecting recipient oocytes and donor cells that will produce cloned embryos with functionally reprogrammed nuclei. This approach will produce information useful in future studies aimed at further deciphering the nuclear reprogramming process.

Venus high temperature atmospheric dropsonde and extreme-environment seismometer (HADES)

NASA Astrophysics Data System (ADS)

Boll, Nathan J.; Salazar, Denise; Stelter, Christopher J.; Landis, Geoffrey A.; Colozza, Anthony J.

2015-06-01

The atmospheric composition and geologic structure of Venus have been identified by the US National Research Council's Decadal Survey for Planetary Science as priority targets for scientific exploration; however, the high temperature and pressure at the surface, along with the highly corrosive chemistry of the Venus atmosphere, present significant obstacles to spacecraft design that have severely limited past and proposed landed missions. Following the methodology of the NASA Innovative Advanced Concepts (NIAC) proposal regime and the Collaborative Modeling and Parametric Assessment of Space Systems (COMPASS) design protocol, this paper presents a conceptual study and initial feasibility analysis for a Discovery-class Venus lander capable of an extended-duration mission at ambient temperature and pressure, incorporating emerging technologies within the field of high temperature electronics in combination with novel configurations of proven, high Technology Readiness Level (TRL) systems. Radioisotope Thermal Power (RTG) systems and silicon carbide (SiC) communications and data handling are examined in detail, and various high-temperature instruments are proposed, including a seismometer and an advanced photodiode imager. The study combines this technological analysis with proposals for a descent instrument package and a relay orbiter to demonstrate the viability of an integrated atmospheric and in-situ geologic exploratory mission that differs from previous proposals by greatly reducing the mass, power requirements, and cost, while achieving important scientific goals.

Venus High Temperature Atmospheric Dropsonde and Extreme-Environment Seismometer (HADES)

NASA Technical Reports Server (NTRS)

Boll, Nathan J.; Salazar, Denise; Stelter, Christopher J.; Landis, Geoffrey A.; Colozza, Anthony J.

2014-01-01

The atmospheric composition and geologic structure of Venus have been identified by the US National Research Council's Decadal Survey for Planetary Science as priority targets for scientific exploration, however the high temperature and pressure at the surface, along with the highly corrosive chemistry of the Venus atmosphere, present significant obstacles to spacecraft design that have severely limited past and proposed landed missions. Following the methodology of the NASA Innovative Advanced Concepts (NIAC) proposal regime and the Collaborative Modeling and Parametric Assessment of Space Systems (COMPASS) design protocol, this paper presents a conceptual study and initial feasibility analysis for a Discovery-class Venus lander capable of an extended-duration mission at ambient temperature and pressure, incorporating emerging technologies within the field of high temperature electronics in combination with novel configurations of proven, high Technology Readiness Level (TRL) systems. Radioisotope Thermal Power (RTG) systems and silicon carbide (SiC) communications and data handling are examined in detail, and various high-temperature instruments are proposed, including a seismometer and an advanced photodiode imager. The study combines this technological analysis with proposals for a descent instrument package and a relay orbiter to demonstrate the viability of an integrated atmospheric and in-situ geologic exploratory mission that differs from previous proposals by greatly reducing the mass, power requirements, and cost, while achieving important scientific goals.

The research of autonomous obstacle avoidance of mobile robot based on multi-sensor integration

NASA Astrophysics Data System (ADS)

Zhao, Ming; Han, Baoling

2016-11-01

The object of this study is the bionic quadruped mobile robot. The study has proposed a system design plan for mobile robot obstacle avoidance with the binocular stereo visual sensor and the self-control 3D Lidar integrated with modified ant colony optimization path planning to realize the reconstruction of the environmental map. Because the working condition of a mobile robot is complex, the result of the 3D reconstruction with a single binocular sensor is undesirable when feature points are few and the light condition is poor. Therefore, this system integrates the stereo vision sensor blumblebee2 and the Lidar sensor together to detect the cloud information of 3D points of environmental obstacles. This paper proposes the sensor information fusion technology to rebuild the environment map. Firstly, according to the Lidar data and visual data on obstacle detection respectively, and then consider two methods respectively to detect the distribution of obstacles. Finally fusing the data to get the more complete, more accurate distribution of obstacles in the scene. Then the thesis introduces ant colony algorithm. It has analyzed advantages and disadvantages of the ant colony optimization and its formation cause deeply, and then improved the system with the help of the ant colony optimization to increase the rate of convergence and precision of the algorithm in robot path planning. Such improvements and integrations overcome the shortcomings of the ant colony optimization like involving into the local optimal solution easily, slow search speed and poor search results. This experiment deals with images and programs the motor drive under the compiling environment of Matlab and Visual Studio and establishes the visual 2.5D grid map. Finally it plans a global path for the mobile robot according to the ant colony algorithm. The feasibility and effectiveness of the system are confirmed by ROS and simulation platform of Linux.

Impaired anticipatory control of grasp during obstacle crossing in Parkinson's disease.

PubMed

McIsaac, Tara L; Diermayr, Gudrun; Albert, Frederic

2012-05-16

During self-paced walking, people with Parkinson's disease maintain anticipatory control during object grasping. However, common functional tasks often include carrying an object while changing step patterns mid-path and maneuvering over obstacles, increasing task complexity and attentional demands. Thus, the present study investigated the effect of Parkinson's disease on the modulation of grasping force changes as a function of gait-related inertial forces. Subjects with Parkinson's disease maintained the ability to scale and to couple over time their grip and inertial forces while walking at irregular step lengths, but were unable to maintain the temporal coupling of grasping forces compared to controls during obstacle crossing. We suggest that this deterioration in anticipatory control is associated with the increased demands of task complexity and attention during obstacle crossing. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

About the Concept of Angle in Elementary School: Misconceptions and Teaching Sequences

ERIC Educational Resources Information Center

Devichi, Claude; Munier, Valerie

2013-01-01

This paper reports classroom research dealing with the difficulties encountered by schoolchildren in the acquisition of angle concept. Two obstacles were pointed out in previous studies: the side-length obstacle and the salience of the prototypical right angle. The first aim of the present study is to determine the extent to which a teaching…

Opportunities and Obstacles: Implementing Stimulus-Funded School Improvement Grants in Maryland, Michigan, and Idaho. Study Methods

ERIC Educational Resources Information Center

Center on Education Policy, 2012

2012-01-01

This paper presents the study methods used for the "Opportunities and Obstacles: Implementing Stimulus-Funded School Improvement Grants in Maryland, Michigan, and Idaho" report. The purpose of this study was to describe how Title I 1003(g) School Improvement Grants awarded through the American Reinvestment and Recovery Act (ARRA) in the…

Building effective international, multicultural alliances for restoration of ejido forests in the Sierra Madre Occidental

Treesearch

Randall Gingrich

2005-01-01

Effective NGO-government-community alliances are the key to overcoming the complex socio-political obstacles to conservation in the Sierra Madre Occidental. Over 80 percent of the territory in the Sierra Madre Occidental is communally owned. Agrarian and other socio-economic conditions present both opportunities and obstacles to conservation. Conservation,...

Health information technology: a few years of magical thinking?

PubMed

Diamond, Carol C; Shirky, Clay

2008-01-01

One of the biggest obstacles to expanding the use of information technology (IT) in health care may be the current narrow focus on how to stimulate its adoption. The challenge of thinking of IT as a tool to improve quality requires serious attention to transforming the U.S. health care system as a whole, rather than simply computerizing the current setup. Proponents of health IT must resist "magical thinking," such as the notion that technology will transform our broken system, absent integrated work on policy or incentives. The alternative route to transforming the system sets all of its sights on the destination.

Reactive, Safe Navigation for Lunar and Planetary Robots

NASA Technical Reports Server (NTRS)

Utz, Hans; Ruland, Thomas

2008-01-01

When humans return to the moon, Astronauts will be accompanied by robotic helpers. Enabling robots to safely operate near astronauts on the lunar surface has the potential to significantly improve the efficiency of crew surface operations. Safely operating robots in close proximity to astronauts on the lunar surface requires reactive obstacle avoidance capabilities not available on existing planetary robots. In this paper we present work on safe, reactive navigation using a stereo based high-speed terrain analysis and obstacle avoidance system. Advances in the design of the algorithms allow it to run terrain analysis and obstacle avoidance algorithms at full frame rate (30Hz) on off the shelf hardware. The results of this analysis are fed into a fast, reactive path selection module, enforcing the safety of the chosen actions. The key components of the system are discussed and test results are presented.

Helper-Dependent Adenoviral Vectors.

PubMed

Rosewell, Amanda; Vetrini, Francesco; Ng, Philip

2011-10-29

Helper-dependent adenoviral vectors are devoid of all viral coding sequences, possess a large cloning capacity, and can efficiently transduce a wide variety of cell types from various species independent of the cell cycle to mediate long-term transgene expression without chronic toxicity. These non-integrating vectors hold tremendous potential for a variety of gene transfer and gene therapy applications. Here, we review the production technologies, applications, obstacles to clinical translation and their potential resolutions, and the future challenges and unanswered questions regarding this promising gene transfer technology.

Helper-Dependent Adenoviral Vectors

PubMed Central

Rosewell, Amanda; Vetrini, Francesco; Ng, Philip

2012-01-01

Helper-dependent adenoviral vectors are devoid of all viral coding sequences, possess a large cloning capacity, and can efficiently transduce a wide variety of cell types from various species independent of the cell cycle to mediate long-term transgene expression without chronic toxicity. These non-integrating vectors hold tremendous potential for a variety of gene transfer and gene therapy applications. Here, we review the production technologies, applications, obstacles to clinical translation and their potential resolutions, and the future challenges and unanswered questions regarding this promising gene transfer technology. PMID:24533227

Computer usage among nurses in rural health-care facilities in South Africa: obstacles and challenges.

PubMed

Asah, Flora

2013-04-01

This study discusses factors inhibiting computer usage for work-related tasks among computer-literate professional nurses within rural healthcare facilities in South Africa. In the past two decades computer literacy courses have not been part of the nursing curricula. Computer courses are offered by the State Information Technology Agency. Despite this, there seems to be limited use of computers by professional nurses in the rural context. Focus group interviews held with 40 professional nurses from three government hospitals in northern KwaZulu-Natal. Contributing factors were found to be lack of information technology infrastructure, restricted access to computers and deficits in regard to the technical and nursing management support. The physical location of computers within the health-care facilities and lack of relevant software emerged as specific obstacles to usage. Provision of continuous and active support from nursing management could positively influence computer usage among professional nurses. A closer integration of information technology and computer literacy skills into existing nursing curricula would foster a positive attitude towards computer usage through early exposure. Responses indicated that change of mindset may be needed on the part of nursing management so that they begin to actively promote ready access to computers as a means of creating greater professionalism and collegiality. © 2011 Blackwell Publishing Ltd.

Explosion hazards of LPG-air mixtures in vented enclosure with obstacles.

PubMed

Zhang, Qi; Wang, Yaxing; Lian, Zhen

2017-07-15

Numerical simulations were performed to study explosion characteristics of liquefied petroleum gas (LPG) explosion in enclosure with a vent. Unlike explosion overpressure and dynamic pressure, explosion temperature of the LPG-air mixture at a given concentration in a vented enclosure has very little variation with obstacle numbers for a given blockage ratio. For an enclosure without obstacle, explosion overpressures for the stoichiometric mixtures and the fuel-lean mixtures reach their maximum within the vent and that for fuel-rich mixture reaches its maximum beyond and near the vent. Dynamic pressures produced by an indoor LPG explosion reach their maximum always beyond the vent no matter obstacles are present or not in the enclosure. A LPG explosion in a vented enclosure with built-in obstacles is strong enough to make the brick and mortar wall with a thickness of 370mm damaged. If there is no obstacle in the enclosure, the lower explosion pressure of several kPa can not break the brick and mortar wall with a thickness of 370mm. For a LPG explosion produced in an enclosure with a vent, main hazards, within the vent, are overpressure and high temperature. However main hazards are dynamic pressure, blast wind, and high temperature beyond the vent. Copyright © 2017 Elsevier B.V. All rights reserved.

An Obstacle-Tolerant Path Planning Algorithm for Mobile-Anchor-Node-Assisted Localization

PubMed Central

Tsai, Rong-Guei

2018-01-01

The location information obtained using a sensor is a critical requirement in wireless sensor networks. Numerous localization schemes have been proposed, among which mobile-anchor-node-assisted localization (MANAL) can reduce costs and overcome environmental constraints. A mobile anchor node (MAN) provides its own location information to assist the localization of sensor nodes. Numerous path planning schemes have been proposed for MANAL, but most scenarios assume the absence of obstacles in the environment. However, in a realistic environment, sensor nodes cannot be located because the obstacles block the path traversed by the MAN, thereby rendering the sensor incapable of receiving sufficient three location information from the MAN. This study proposes the obstacle-tolerant path planning (OTPP) approach to solve the sensor location problem owing to obstacle blockage. OTPP can approximate the optimum beacon point number and path planning, thereby ensuring that all the unknown nodes can receive the three location information from the MAN and reduce the number of MAN broadcast packet times. Experimental results demonstrate that OTPP performs better than Z-curves because it reduces the total number of beacon points utilized and is thus more suitable in an obstacle-present environment. Compared to the Z-curve, OTPP can reduce localization error and improve localization coverage. PMID:29547582

From research to production: field induced electro-mechanical polymer-transducer (Conference Presentation)

NASA Astrophysics Data System (ADS)

Kovacs, Gabor M.

2017-04-01

In the past decades the development of compliant dielectric materials, capable of storing high electric energy density, is the object of considerable research efforts for commercial applications. Compared to the widely used soft dielectrics as compliant insulators, only a small variety of commercially products based on dielectric polymer transducers are available on the market up to date. A whole bunch of research activities worldwide has created a lot of very useful knowledge; but many researchers have been faced to different obstacles to manufacture devices for demonstrations. However, building handy demonstrators is one of the most relevant action in order to attract the interest of decision makers of industrial companies. Moreover, low cost devices strictly require highly efficient production methods and facilities to become competitive on the market. This aspect contains the ultimate requirement especially for very high output rates and represents one of the major topic at most negotiations. All technological problems linked to this issue have been addressed only a little in the past R+D activities and are still widely not satisfactory solved. The present talk will provide an overview of the options for opening the door of industrial production of polymer transducers and the remaining obstacles to be solved for the next step. In particular, the most relevant actions to be taken for enabling high capacity production at very low cost will be discussed, which have an essential impact on the direction of future research activities.

Identification and analysis of obstacles in bioterrorism preparedness and response

NASA Astrophysics Data System (ADS)

Sincavage, Suzanne Michele

The focus of this study was to identify and analyze the obstacles to bioterrorism preparedness and response facing emergency management agencies and public authorities. In order to establish the limits of this discussion, the obstacles will examine a combined conceptual framework of public health, environmental security and social response. The interdisciplinary characteristics of this framework are ideal for addressing the issue of bioterrorism because of its simultaneous impact, which encompasses the complex interrelationships that pertain to public health and national security and social response. Based on a review of literature, the obstacles presented range from the absence of an effective surveillance system for biological terrorism related diseases to the inadequate training of first responders in bioterrorism preparedness and the difficult challenges of a mass casualty situation and the intense pressures associated with the crisis response. Furthermore, the impending reality of bioterrorism will further illustrate a close examination of the characteristics and management of three major biowarfare agents---anthrax, plague and smallpox. Finally, to provide a realistic understanding of the impact of bioterrorism, three case studies of actual events and two hypothetical scenarios will be discussed. Specifically, the discussion will provide the following three unconventional terrorist attacks: the recent anthrax attacks of 2001, the Aum Shinrikyo's attack of the Tokyo subway in 1995, and the Rajneeshees' use of salmonella poisoning in 1994. The inclusion of the hypothetical scenarios of two massive outbreaks of smallpox and anthrax will be presented to illuminate the seriousness and magnitude of the threat of bioterrorism and the probable consequences of failing to overcome the obstacles presented in this study. The importance of this research cannot be overemphasized, the threat is undeniably serious, and the potential for biological agents to cause devastating casualties can be minimized with the fighting strength of education.

A Compact Magnetic Field-Based Obstacle Detection and Avoidance System for Miniature Spherical Robots.

PubMed

Wu, Fang; Vibhute, Akash; Soh, Gim Song; Wood, Kristin L; Foong, Shaohui

2017-05-28

Due to their efficient locomotion and natural tolerance to hazardous environments, spherical robots have wide applications in security surveillance, exploration of unknown territory and emergency response. Numerous studies have been conducted on the driving mechanism, motion planning and trajectory tracking methods of spherical robots, yet very limited studies have been conducted regarding the obstacle avoidance capability of spherical robots. Most of the existing spherical robots rely on the "hit and run" technique, which has been argued to be a reasonable strategy because spherical robots have an inherent ability to recover from collisions. Without protruding components, they will not become stuck and can simply roll back after running into bstacles. However, for small scale spherical robots that contain sensitive surveillance sensors and cannot afford to utilize heavy protective shells, the absence of obstacle avoidance solutions would leave the robot at the mercy of potentially dangerous obstacles. In this paper, a compact magnetic field-based obstacle detection and avoidance system has been developed for miniature spherical robots. It utilizes a passive magnetic field so that the system is both compact and power efficient. The proposed system can detect not only the presence, but also the approaching direction of a ferromagnetic obstacle, therefore, an intelligent avoidance behavior can be generated by adapting the trajectory tracking method with the detection information. Design optimization is conducted to enhance the obstacle detection performance and detailed avoidance strategies are devised. Experimental results are also presented for validation purposes.

Training addiction professionals in empirically supported treatments: perspectives from the treatment community.

PubMed

Hartzler, Bryan; Rabun, Carl

2014-01-01

Large-scale dissemination efforts seek to expand opportunities for the addiction treatment community to receive training in empirically supported treatments (ESTs). Prospective consumers of such training are valuable sources of input about content of interest, preferences for how training events are structured, and obstacles that deter receipt of training. In this mixed-method study, data were collected in 64 semistructured individual interviews with personnel during site visits to 16 community opioid treatment programs (OTPs). At each OTP, interviews were completed with the executive director, a clinical supervisor, and 2 direct-service clinicians. Topical interests were analyzed qualitatively in a cultural domain analysis. Likert ratings of training event preferences were analyzed via generalized linear mixed models (GLMMs), and unstructured interviewee comments were analyzed via narrative analysis. Obstacles to training receipt were analyzed qualitatively with both content coding and narrative analysis. Based on topics of reported interest, cultural domain analysis suggests as ESTs of note: Multidimensional Family Therapy, Motivational Enhancement Therapy, Relapse Prevention Therapy, "Seeking Safety," and broad addiction-focused pharmacotherapy. Regarding training event preferences, GLMMs and narrative analysis revealed clear preferences for time-distributed trainings and use of participatory activities (e.g., trainer demonstrations, role plays, small group exercises). Content coding identified cost as the primary obstacle to receipt of EST trainings, followed by lack of time, logistical challenges, and disinterest, and narrative analysis elaborated on contextual issues underlying these obstacles. As primary consumers of EST technologies, the treatment community has valuable input to offer. Dissemination efforts may be enhanced by greater consideration of their preferences for training content and event structure, as well as practical obstacles that challenge their receipt of training.

Evolution, Nature, Uses and Issues in the Creation of Local School District Comprehensive Information Systems.

ERIC Educational Resources Information Center

Hathaway, Walter E.

Efficient and convenient comprehensive information systems, long kept from coming into being by a variety of obstacles, are now made possible by the concept of distributive processing and the technology of micro- and mini-computer networks. Such systems can individualize instruction, group students efficiently, cut administrative costs, streamline…

A Systematic Approach to Faculty Development--Capability Improvement for Blended Learning

ERIC Educational Resources Information Center

Badawood, Ashraf; Steenkamp, Annette Lerine; Al-Werfalli, Daw

2013-01-01

Blended learning (BL) provides an efficient and effective instructional experience. However, adopting a BL approach poses some challenges to faculty; the most important obstacle found in this research is faculty's lack of knowledge regarding the use of technology in their teaching. This challenge prompted the research project focused on improving…

Health Plans Can't Ignore The Customer Experience Any Longer.

PubMed

Swanson, Erik

2017-10-01

With regulations limiting differentiation between products, health plans must rethink consumer experience to meet expectations of today's consumers, who seek convenience, quality, and speed from their health care organizations. Many plans understand they need to connect more effectively with their end customers, but technological, cultural, and other obstacles are in the way.

The Changing Dynamics of Health Care: Physician Perceptions of Technology in Medical Practices

ERIC Educational Resources Information Center

Hatton, Jerald D.

2012-01-01

Political, economic, and safety concerns have militated for the adoption of electronic health records (EHR) by physicians in the United States, but current rates of adoption have failed to achieve the expected levels. This qualitative phenomenological study of practicing physicians reveals obstacles to adoption. Maintaining the physicians'…

When and Where You Want It: Continuing Education from a Distance

ERIC Educational Resources Information Center

Shade, Stacy Deck; Barber, Gerard M.

2004-01-01

Online technology is increasingly being used as a tool for delivery of continuing education to health care professionals. This paper discusses key lessons learned in developing a distance-learning program. It provides practical information on ways to enhance interactivity and overcome obstacles. Preliminary outcomes for learners in a four-state…

Building a National Security Program at a Small School: Identifying Opportunities and Overcoming Challenges

ERIC Educational Resources Information Center

Grossman, Michael; Schortgen, Francis

2016-01-01

This article offers insights into the overall program development process and--institutional obstacles and constraints notwithstanding--successful introduction of a new national security program at a small liberal arts university at a time of growing institutional prioritization of science, technology, engineering, and mathematics (STEM) programs.…

Developing Digital Information Literacy in Higher Education: Obstacles and Supports

ERIC Educational Resources Information Center

Jeffrey, Lynn; Hegarty, Bronwyn; Kelly, Oriel; Penman, Merrolee; Coburn, Dawn; McDonald, Jenny

2011-01-01

The development of digital information literacy (DIL) has been slow in comparison to changes in information communication technologies, and this remains an issue for the higher education sector. Competency in such skills is essential to full participation in society and work. In addition, these skills are regarded as underpinning the ability to…

Motivational Factors in Self-Directed Informal Learning from Online Learning Resources

ERIC Educational Resources Information Center

Song, Donggil; Bonk, Curtis J.

2016-01-01

Learning is becoming more self-directed and informal with the support of emerging technologies. A variety of online resources have promoted informal learning by allowing people to learn on demand and just when needed. It is significant to understand self-directed informal learners' motivational aspects, their learning goals, obstacles, and…

Brain-Based Teaching in the Digital Age

ERIC Educational Resources Information Center

Sprenger, Marilee

2010-01-01

In the digital age, your students have the ways, means, and speed to gather any information they want. But they need your guidance more than ever. Discover how digital technology is actually changing your students' brains. Learn why this creates new obstacles for teachers, but also opens up potential new pathways for learning. You will understand…

Challenges Faced by Key Stakeholders Using Educational Online Technologies in Blended Tertiary Environments

ERIC Educational Resources Information Center

Tuapawa, Kimberley

2016-01-01

Traditional learning spaces have evolved into dynamic blended tertiary environments (BTEs), providing a modern means through which tertiary education institutes (TEIs) can augment delivery to meet stakeholder needs. Despite the significant demand for web-enabled learning, there are obstacles concerning the use of EOTs, which challenge the…

Effectiveness of Combined Delivery Modalities for Distance Learning and Resident Learning.

ERIC Educational Resources Information Center

Dean, Peter J.; Stahl, Michael J.; Sylwester, David L.; Peat, Jillian A.

2001-01-01

Explores effectiveness of a distance education program for physicians, and what progressive administrators can do to remove the traditional obstacles to such a program. Discusses effects of global change and technology on the economy; University of Tennessee's Physician Executive MBA Program using a mixed-mode of delivery; and methodology,…

A study of how unmanned aircraft systems can support the Kansas Department of Transportation's efforts to improve efficiency, safety, and cost reduction : final report.

DOT National Transportation Integrated Search

2016-08-01

Regulations for using Unmanned Aircraft Systems (UAS) are not yet standardized by the Federal Aviation : Administration (FAA). This creates tedious obstacles for those who wish to utilize the technology. The goal of this : research is to provide a ju...

Elementary EFL Teachers' Computer Phobia and Computer Self-Efficacy in Taiwan

ERIC Educational Resources Information Center

Chen, Kate Tzuching

2012-01-01

The advent and application of computer and information technology has increased the overall success of EFL teaching; however, such success is hard to assess, and teachers prone to computer avoidance face negative consequences. Two major obstacles are high computer phobia and low computer self-efficacy. However, little research has been carried out…

Improving Test Preparation for Students with Special Needs: Web-Based Tutorial, Student Charting, and a Text Reader

ERIC Educational Resources Information Center

Menard, Lauren A.

2011-01-01

Obstacles to the classroom implementation of the fourth grade Math component of Louisiana's web-based testing tutorial were addressed in this informal pilot. Technology integration improved standardized test preparation for students with special needs. Supplemental test preparation sessions give the benefits of (a) increased familiarity with…

Technology test results from an intelligent, free-flying robot for crew and equipment retrieval in space

NASA Technical Reports Server (NTRS)

Erickson, J.; Goode, R.; Grimm, K.; Hess, C.; Norsworthy, R.; Anderson, G.; Merkel, L.; Phinney, D.

1992-01-01

The ground-based demonstrations of Extra Vehicular Activity (EVA) Retriever, a voice-supervised, intelligent, free-flying robot, are designed to evaluate the capability to retrieve objects (astronauts, equipment, and tools) which have accidentally separated from the Space Station. The EVA Retriever software is required to autonomously plan and execute a target rendezvous, grapple, and return to base while avoiding stationary and moving obstacles with subsequent object handover. The software architecture incorporates a heirarchical decomposition of the control system that is horizontally partitioned into five major functional subsystems: sensing, perception, world model, reasoning, and acting. The design provides for supervised autonomy as the primary mode of operation. It is intended to be an evolutionary system improving in capability over time and as it earns crew trust through reliable and safe operation. This paper gives an overview of the hardware, a focus on software, and a summary of results achieved recently from both computer simulations and air bearing floor demonstrations. Limitations of the technology used are evaluated. Plans for the next phase, during which moving targets and obstacles drive realtime behavior requirements, are discussed.

Technology test results from an intelligent, free-flying robot for crew and equipment retrieval in space

NASA Astrophysics Data System (ADS)

Erickson, Jon D.; Goode, R.; Grimm, K. A.; Hess, Clifford W.; Norsworthy, Robert S.; Anderson, Greg D.; Merkel, L.; Phinney, Dale E.

1992-03-01

The ground-based demonstrations of Extra Vehicular Activity (EVA) Retriever, a voice- supervised, intelligent, free-flying robot, are designed to evaluate the capability to retrieve objects (astronauts, equipment, and tools) which have accidentally separated from the space station. The EVA Retriever software is required to autonomously plan and execute a target rendezvous, grapple, and return to base while avoiding stationary and moving obstacles with subsequent object handover. The software architecture incorporates a hierarchical decomposition of the control system that is horizontally partitioned into five major functional subsystems: sensing, perception, world model, reasoning, and acting. The design provides for supervised autonomy as the primary mode of operation. It is intended to be an evolutionary system improving in capability over time and as it earns crew trust through reliable and safe operation. This paper gives an overview of the hardware, a focus on software, and a summary of results achieved recently from both computer simulations and air bearing floor demonstrations. Limitations of the technology used are evaluated. Plans for the next phase, during which moving targets and obstacles drive realtime behavior requirements, are discussed.

Velodyne HDL-64E lidar for unmanned surface vehicle obstacle detection

NASA Astrophysics Data System (ADS)

Halterman, Ryan; Bruch, Michael

2010-04-01

The Velodyne HDL-64E is a 64 laser 3D (360×26.8 degree) scanning LIDAR. It was designed to fill perception needs of DARPA Urban Challenge vehicles. As such, it was principally intended for ground use. This paper presents the performance of the HDL-64E as it relates to the marine environment for unmanned surface vehicle (USV) obstacle detection and avoidance. We describe the sensor's capacity for discerning relevant objects at sea- both through subjective observations of the raw data and through a rudimentary automated obstacle detection algorithm. We also discuss some of the complications that have arisen with the sensor.

The Humanity of Writing: The NEH Cross-Disciplinary Writing Program at West Chester State College.

ERIC Educational Resources Information Center

Weiss, Robert H.

A pilot project funded by the National Endowment for the Humanities (NEH) and a state college educational trust fund to improve writing in the humanities and across the curriculum is described in this paper. Also presented are the obstacles confronted in establishing the project, a seven-point strategy developed to counter those obstacles, the…

Rules to fly by: pigeons navigating horizontal obstacles limit steering by selecting gaps most aligned to their flight direction.

PubMed

Ros, Ivo G; Bhagavatula, Partha S; Lin, Huai-Ti; Biewener, Andrew A

2017-02-06

Flying animals must successfully contend with obstacles in their natural environments. Inspired by the robust manoeuvring abilities of flying animals, unmanned aerial systems are being developed and tested to improve flight control through cluttered environments. We previously examined steering strategies that pigeons adopt to fly through an array of vertical obstacles (VOs). Modelling VO flight guidance revealed that pigeons steer towards larger visual gaps when making fast steering decisions. In the present experiments, we recorded three-dimensional flight kinematics of pigeons as they flew through randomized arrays of horizontal obstacles (HOs). We found that pigeons still decelerated upon approach but flew faster through a denser array of HOs compared with the VO array previously tested. Pigeons exhibited limited steering and chose gaps between obstacles most aligned to their immediate flight direction, in contrast to VO navigation that favoured widest gap steering. In addition, pigeons navigated past the HOs with more variable and decreased wing stroke span and adjusted their wing stroke plane to reduce contact with the obstacles. Variability in wing extension, stroke plane and wing stroke path was greater during HO flight. Pigeons also exhibited pronounced head movements when negotiating HOs, which potentially serve a visual function. These head-bobbing-like movements were most pronounced in the horizontal (flight direction) and vertical directions, consistent with engaging motion vision mechanisms for obstacle detection. These results show that pigeons exhibit a keen kinesthetic sense of their body and wings in relation to obstacles. Together with aerodynamic flapping flight mechanics that favours vertical manoeuvring, pigeons are able to navigate HOs using simple rules, with remarkable success.

Rules to fly by: pigeons navigating horizontal obstacles limit steering by selecting gaps most aligned to their flight direction

PubMed Central

Ros, Ivo G.; Bhagavatula, Partha S.; Lin, Huai-Ti

2017-01-01

Flying animals must successfully contend with obstacles in their natural environments. Inspired by the robust manoeuvring abilities of flying animals, unmanned aerial systems are being developed and tested to improve flight control through cluttered environments. We previously examined steering strategies that pigeons adopt to fly through an array of vertical obstacles (VOs). Modelling VO flight guidance revealed that pigeons steer towards larger visual gaps when making fast steering decisions. In the present experiments, we recorded three-dimensional flight kinematics of pigeons as they flew through randomized arrays of horizontal obstacles (HOs). We found that pigeons still decelerated upon approach but flew faster through a denser array of HOs compared with the VO array previously tested. Pigeons exhibited limited steering and chose gaps between obstacles most aligned to their immediate flight direction, in contrast to VO navigation that favoured widest gap steering. In addition, pigeons navigated past the HOs with more variable and decreased wing stroke span and adjusted their wing stroke plane to reduce contact with the obstacles. Variability in wing extension, stroke plane and wing stroke path was greater during HO flight. Pigeons also exhibited pronounced head movements when negotiating HOs, which potentially serve a visual function. These head-bobbing-like movements were most pronounced in the horizontal (flight direction) and vertical directions, consistent with engaging motion vision mechanisms for obstacle detection. These results show that pigeons exhibit a keen kinesthetic sense of their body and wings in relation to obstacles. Together with aerodynamic flapping flight mechanics that favours vertical manoeuvring, pigeons are able to navigate HOs using simple rules, with remarkable success. PMID:28163883

A temporal PIV study of flame/obstacle generated vortex interactions within a semi-confined combustion chamber

NASA Astrophysics Data System (ADS)

Jarvis, S.; Hargrave, G. K.

2006-01-01

Experimental data obtained using a new multiple-camera digital particle image velocimetry (PIV) technique are presented for the interaction between a propagating flame and the turbulent recirculating velocity field generated during flame-solid obstacle interaction. The interaction between the gas movement and the obstacle creates turbulence by vortex shedding and local wake recirculations. The presence of turbulence in a flammable gas mixture can wrinkle a flame front, increasing the flame surface area and enhancing the burning rate. To investigate propagating flame/turbulence interaction, a novel multiple-camera digital PIV technique was used to provide high spatial and temporal characterization of the phenomenon for the turbulent flow field in the wake of three sequential obstacles. The technique allowed the quantification of the local flame speed and local flow velocity. Due to the accelerating nature of the explosion flow field, the wake flows develop 'transient' turbulent fields. Multiple-camera PIV provides data to define the spatial and temporal variation of both the velocity field ahead of the propagating flame and the flame front to aid the understanding of flame-vortex interaction. Experimentally obtained values for flame displacement speed and flame stretch are presented for increasing vortex complexity.

Safe Local Navigation for Visually Impaired Users With a Time-of-Flight and Haptic Feedback Device.

PubMed

Katzschmann, Robert K; Araki, Brandon; Rus, Daniela

2018-03-01

This paper presents ALVU (Array of Lidars and Vibrotactile Units), a contactless, intuitive, hands-free, and discreet wearable device that allows visually impaired users to detect low- and high-hanging obstacles, as well as physical boundaries in their immediate environment. The solution allows for safe local navigation in both confined and open spaces by enabling the user to distinguish free space from obstacles. The device presented is composed of two parts: a sensor belt and a haptic strap. The sensor belt is an array of time-of-flight distance sensors worn around the front of a user's waist, and the pulses of infrared light provide reliable and accurate measurements of the distances between the user and surrounding obstacles or surfaces. The haptic strap communicates the measured distances through an array of vibratory motors worn around the user's upper abdomen, providing haptic feedback. The linear vibration motors are combined with a point-loaded pretensioned applicator to transmit isolated vibrations to the user. We validated the device's capability in an extensive user study entailing 162 trials with 12 blind users. Users wearing the device successfully walked through hallways, avoided obstacles, and detected staircases.

Modal element method for potential flow in non-uniform ducts: Combining closed form analysis with CFD

NASA Technical Reports Server (NTRS)

Baumeister, Kenneth J.; Baumeister, Joseph F.

1994-01-01

An analytical procedure is presented, called the modal element method, that combines numerical grid based algorithms with eigenfunction expansions developed by separation of variables. A modal element method is presented for solving potential flow in a channel with two-dimensional cylindrical like obstacles. The infinite computational region is divided into three subdomains; the bounded finite element domain, which is characterized by the cylindrical obstacle and the surrounding unbounded uniform channel entrance and exit domains. The velocity potential is represented approximately in the grid based domain by a finite element solution and is represented analytically by an eigenfunction expansion in the uniform semi-infinite entrance and exit domains. The calculated flow fields are in excellent agreement with exact analytical solutions. By eliminating the grid surrounding the obstacle, the modal element method reduces the numerical grid size, employs a more precise far field boundary condition, as well as giving theoretical insight to the interaction of the obstacle with the mean flow. Although the analysis focuses on a specific geometry, the formulation is general and can be applied to a variety of problems as seen by a comparison to companion theories in aeroacoustics and electromagnetics.

[Assessment of an educational technology in the string literature about breastfeeding].

PubMed

de Oliveira, Paula Marciana Pinheiro; Pagliuca, Lorita Marlena Freitag

2013-02-01

The goal of this study was to assess educational technology in the string literature about breastfeeding. The study was conducted between March and September 2009 by breastfeeding experts and experts on string literature. A psychometric model was adopted as the theoretical-methodological framework. For data collection, an instrument was used to assess the content about breastfeeding and the string literature rules. The analysis was based on comparisons of the notes and critical reflections of experts. Ethical guidelines were followed during the study. After the assessments, the educational technology was adjusted until all of the experts agreed. The assessment of educational technology can reduce obstacles to information dissemination and can lead to improvements in quality of life.

Combating malignant astrocytes: Strategies mitigating tumor invasion.

PubMed

Umans, Robyn A; Sontheimer, Harald

2018-01-01

Malignant gliomas are glial-derived, primary brain tumors that carry poor prognosis. Existing therapeutics are largely ineffective and dramatically affect quality of life. The standard of care details a taxing combination of surgical resection, radiation of the resection cavity, and temozolomide (TMZ) chemotherapy, with treatment extending life by only an average of months (Maher et al., 2001; Stupp et al., 2005). Despite scientific and technological advancement, surgery remains the most important treatment modality. Therapeutic obstacles include xenobiotic protection conveyed by the blood-brain barrier (Zhang et al., 2015), invasiveness and therapeutic resistance of tumor cell populations (Bao et al., 2006), and distinctive attributes of secondary glioma occurrence (Ohgaki and Kleihues, 2013). While these brain malignancies can be classified by grade or grouped by molecular subclass, each tumor presents itself as its own complication. Based on all of these obstacles, new therapeutic approaches are urgently needed. These will likely emerge from numerous exciting studies of glioma biology that are ongoing and reviewed here. These show unexpected roles for ion channels, amino-acid transporters, and connexin gap junctions in supporting the invasive growth of gliomas. These studies have identified a number of proteins that may be targeted for therapy in the future. Copyright © 2017 Elsevier Ireland Ltd and Japan Neuroscience Society. All rights reserved.

Mobility performance analysis of an innovation lunar rover with diameter-variable wheel

NASA Astrophysics Data System (ADS)

Sun, Gang; Gao, Feng; Sun, Peng; Xu, Guoyan

2007-11-01

To achieve excellent mobility performance, a four-wheel, all-wheel drive lunar rover with diameter-variable wheel was presented, the wheel can be contracted and extended by the motor equipped in the wheel hub, accompanied with wheel diameter varying from 200mm to 390mm. The wheel sinkage and drawbar pull force were predicated with terramechanics formulae and lunar regolith mechanic parameters employed, furthermore, the slope traversability was investigated through quasi-static modeling mechanic analysis, also the obstacle resistance and the maximum negotiable obstacle height for different wheel radius were derived from the equations of static equilibrium of the rover. Analysis results show that for the innovation lunar rover presented, it will bring much better slope traveling stability and obstacle climbing capability than rovers with normal wheels, these will improve the rover mobility performance and stabilize the rover's frame, smooth the motion of sensors.

Institutional obstacles to expansion of world food production.

PubMed

Crosson, P R

1975-05-09

It was argued that over the near-to-medium term-roughly to the mid-1980's-there is enough potential for growth in existing Green Revolution technology and in technical capacity of farmers that institutions affecting these two sources of increased food production probably will not be seriously constraining. The principal bottlenecks likely will be found among those institutions affecting farmers' incentives to innovate. There is impressive evidence that when other conditions for innovation are favorable the supply of marketing services, for both inputs and outputs, is quite elastic. This seems to include the supply of funds from rural saving and informal credit sources, although the evidence is less clear in this respect. The situation concerning price relations and availability of inputs appears mixed. If national income growth targets are achieved, then the growth in total demand for food in the LDC's should be fast enough to support incentive prices for farmers. This advantage could be lost, however, if governments adopt policies to suppress food prices to keep down the cost of living. The price of fertilizers is expected to fall from the high levels of 1974, the amount of the fall depending in good measure on the success of the LDC's in increasing fertilizer production. Historically, their efforts to expand capacity have been relatively inefficient. Moreover, many countries still lack adequate capacity to produce the HYV's and pesticides. Even with good progress in expanding domestic production of inputs, imports will continue to be an important source of supply. Maintenance of present high prices of petroleum products could be a major obstacle to financing these imports on the necessary scale because of the drain it would place on available foreign exchange. I conclude, on balance, that prices and availability of fertilizers, pesticides, and seeds could have important negative effects on farmers' incentives to adopt Green Revolution technology. Rigidities in water management institutions may be even more limiting, for reasons noted in the previous section. The role of existing land tenure institutions is not clear. The tentative conclusion, however, is that over the near-to-medium term the maintenance will not be a major obstacle to further spread of the Green Revolution. Over the longer term, it could become more seriously limiting. The reason is that continued expansion of food production will eventually require the invention and adoption of new technologies and a higher level of technical and managerial skill than most farmers in the LDC's now possess. To do this will require substantial investments in domestic research and extension institutions and in rural education. In countries where a small class of large landowners wield substantial political power, these investments may not occur on the necessary scale because the large farmers have their own means of acquiring the technology and little perceived interest in supporting the upgrading of the skills of small farmers. This review of institutional obstacles to expansion of food production in the LDC's must end on a tentative note. The review does suggest some observations about the process of institutional change, however. There is impressive evidence of strong latent potential in the private sector of the LDC's for mobilizing the resources and effort needed for agricultural progress when the private economic rewards for doing so are high. Under these circumstances, needed changes in the institutions required to mobilize the resources and direct the effort seem relatively easy to achieve. Institutional resistance is stronger in situations where influential interests perceive change as a threat or where there is no direct personal economic reward to change, as in the typical public institution. The latter point is particularly important because the performance of public institutions is critical. Development of new technology, the fundamental condition for continued longterm growth, is basically a public responsibility because the gains from adoption usually cannot be sufficiently captured by private institutions to justify their assuming the cost. Although private firms often have incentives to impart technical knowledge to farmers as a way of widening the market for their products, the broadening and strengthening of the institutional structures concerned with both the general and technical education of farmers is a public responsibility. This is true also of the development of large irrigation systems, both because of the scale of the needed investments and the potential for social conflict in water management. The lack of a well-defined mechanism that would link responses of public institutions to the large social payoffs to increased public investment in irrigation, new technology, and technical abilities of farmers may prove in the long run to be the most important single obstacle to adequate growth of food production in the LDC's.

Promoting the Appropriate Use of Advanced Radiation Technologies in Oncology: Summary of a National Cancer Policy Forum Workshop.

PubMed

Smith, Grace L; Ganz, Patricia A; Bekelman, Justin E; Chmura, Steven J; Dignam, James J; Efstathiou, Jason A; Jagsi, Reshma; Johnstone, Peter A; Steinberg, Michael L; Williams, Stephen B; Yu, James B; Zietman, Anthony L; Weichselbaum, Ralph R; Tina Shih, Ya-Chen

2017-03-01

Leaders in the oncology community are sounding a clarion call to promote "value" in cancer care decisions. Value in cancer care considers the clinical effectiveness, along with the costs, when selecting a treatment. To discuss possible solutions to the current obstacles to achieving value in the use of advanced technologies in oncology, the National Cancer Policy Forum of the National Academies of Sciences, Engineering, and Medicine held a workshop, "Appropriate Use of Advanced Technologies for Radiation Therapy and Surgery in Oncology" in July 2015. The present report summarizes the discussions related to radiation oncology. The workshop convened stakeholders, including oncologists, researchers, payers, policymakers, and patients. Speakers presented on key themes, including the rationale for a value discussion on advanced technology use in radiation oncology, the generation of scientific evidence for value of advanced radiation technologies, the effect of both scientific evidence and "marketplace" (or economic) factors on the adoption of technologies, and newer approaches to improving value in the practice of radiation oncology. The presentations were followed by a panel discussion with dialogue among the stakeholders. Challenges to generating evidence for the value of advanced technologies include obtaining contemporary, prospective, randomized, and representative comparative effectiveness data. Proposed solutions include the use of prospective registry data; integrating radiation oncology treatment, outcomes, and quality benchmark data; and encouraging insurance coverage with evidence development. Challenges to improving value in practice include the slow adoption of higher value and the de-adoption of lower value treatments. The proposed solutions focused on engaging stakeholders in iterative, collaborative, and evidence-based efforts to define value and promote change in radiation oncology practice. Recent examples of ongoing or successful responses to the discussed challenges were provided. Discussions of "value" have increased as a priority in the radiation oncology community. Practitioners in the radiation oncology community can play a critical role in promoting a value-oriented framework to approach radiation oncology treatment. Copyright © 2016 Elsevier Inc. All rights reserved.

The ascendance of microphysiological systems to solve the drug testing dilemma

PubMed Central

Dehne, Eva-Maria; Hasenberg, Tobias; Marx, Uwe

2017-01-01

The development of drugs is a process obstructed with manifold security and efficacy concerns. Although animal models are still widely used to meet the diligence required, they are regarded as outdated tools with limited predictability. Novel microphysiological systems intend to create systemic models of human biology. Their ability to host 3D organoid constructs in a controlled microenvironment with mechanical and electrophysiological stimuli enables them to create and maintain homeostasis. These platforms are, thus, envisioned to be superior tools for testing and developing substances such as drugs, cosmetics and chemicals. We will present reasons why microphysiological systems are required for the emerging demands, highlight current technological and regulatory obstacles, and depict possible solutions from state-of-the-art platforms from major contributors. PMID:28670475

Legal issues in clouds: towards a risk inventory.

PubMed

Djemame, Karim; Barnitzke, Benno; Corrales, Marcelo; Kiran, Mariam; Jiang, Ming; Armstrong, Django; Forgó, Nikolaus; Nwankwo, Iheanyi

2013-01-28

Cloud computing technologies have reached a high level of development, yet a number of obstacles still exist that must be overcome before widespread commercial adoption can become a reality. In a cloud environment, end users requesting services and cloud providers negotiate service-level agreements (SLAs) that provide explicit statements of all expectations and obligations of the participants. If cloud computing is to experience widespread commercial adoption, then incorporating risk assessment techniques is essential during SLA negotiation and service operation. This article focuses on the legal issues surrounding risk assessment in cloud computing. Specifically, it analyses risk regarding data protection and security, and presents the requirements of an inherent risk inventory. The usefulness of such a risk inventory is described in the context of the OPTIMIS project.

The goldstone energy project

NASA Technical Reports Server (NTRS)

Bartos, K. P.

1978-01-01

The Golstone Energy Project was established in 1974 to investigate ways in which the Goldstone Deep Space Complex in California could be made partly or completely energy-sufficient, especially through the use of solar- and wind-derived energy resources. Ways in which energy could be conserved at the Complex were also studied. Findings included data on both wind and solar energy. Obstacles to demonstrating energy self-sufficiency are: (1) operation and maintenance costs of solar energy systems are estimated to be much higher than conventional energy systems, (2) initial capital costs of present-day technology solar collectors are high and are compounded by low collector efficiency, and (3) no significant market force exists to create the necessary industry to reduce costs through mass production and broad open-market competition.

Calculating potential fields using microchannel spatial light modulators

NASA Technical Reports Server (NTRS)

Reid, Max B.

1993-01-01

We describe and present experimental results of the optical calculation of potential field maps suitable for mobile robot navigation. The optical computation employs two write modes of a microchannel spatial light modulator (MSLM). In one mode, written patterns expand spatially, and this characteristic is used to create an extended two dimensional function representing the influence of the goal in a robot's workspace. Distinct obstacle patterns are written in a second, non-expanding, mode. A model of the mechanisms determining MSLM write mode characteristics is developed and used to derive the optical calculation time for full potential field maps. Field calculations at a few hertz are possible with current technology, and calculation time vs. map size scales favorably in comparison to digital electronic computation.

The ascendance of microphysiological systems to solve the drug testing dilemma.

PubMed

Dehne, Eva-Maria; Hasenberg, Tobias; Marx, Uwe

2017-06-01

The development of drugs is a process obstructed with manifold security and efficacy concerns. Although animal models are still widely used to meet the diligence required, they are regarded as outdated tools with limited predictability. Novel microphysiological systems intend to create systemic models of human biology. Their ability to host 3D organoid constructs in a controlled microenvironment with mechanical and electrophysiological stimuli enables them to create and maintain homeostasis. These platforms are, thus, envisioned to be superior tools for testing and developing substances such as drugs, cosmetics and chemicals. We will present reasons why microphysiological systems are required for the emerging demands, highlight current technological and regulatory obstacles, and depict possible solutions from state-of-the-art platforms from major contributors.

Technology-Enhanced Learning in Science (TELS)

NASA Astrophysics Data System (ADS)

Linn, Marcia

2006-12-01

The overall research question addressed by the NSF-funded echnologyEnhanced Learning in Science (TELS) Center is whether interactive scientific visualizations embedded in high quality instructional units can be used to increase pre-college student learning in science. The research draws on the knowledge integration framework to guide the design of instructional modules, professional development activities, and assessment activities. This talk reports on results from the first year where 50 teachers taught one of the 12 TELS modules in over 200 classes in 16 diverse schools. Assessments scored with the knowledge integration rubric showed that students made progress in learning complex physics topics such as electricity, mechanics, and thermodynamics. Teachers encountered primarily technological obstacles that the research team was able to address prior to implementation. Powerful scientific visualizations required extensive instructional supports to communicate to students. Currently, TELS is refining the modules, professional development, and assessments based on evidence from the first year. Preliminary design principles intended to help research teams build on the findings will be presented for audience feedback and discussion.

Implementing Courseware to Support Learning through Real-World Erroneous Examples: Students' Perceptions of Tertiary Courseware and Obstacles to Implementing Effective Delivery through VLE

ERIC Educational Resources Information Center

Monthienvichienchai, Rachada; Melis, Erica

2006-01-01

This paper presents a study in a UK university that investigated how first-year (freshman) Information Systems undergraduates perceive learning through courseware containing real-world erroneous examples derived from their peers and what obstacles had to be overcome to implement effective e-Learning support for using and creating such courseware.…

Vegetation Use for Resolving Electromagnetic Compatibility and Ecology Issues

NASA Astrophysics Data System (ADS)

Zvezdina, M. Yu; Shokova, Yu A.; Cherckesova, L. V.; Golovko, T. M.; Cherskaya, A. A.

2017-05-01

The wide spread of Information and Communication Technologies and the development of Internet-enabled mobile applications have aggravated electromagnetic compatibility and ecology problems. Inability to excite electromagnetic field of a desired structure and strength with traditional approaches actualizes additional actions, including providing diffraction on propagation path, to resolve these issues. Diffraction on a stand-alone obstacle along the propagation path and the one on set of obstacles near receive antenna location can be considered as the additional actions in ultrashort band. The accomplished studies have shown that one the most effective means to lower electromagnetic field strength is to shield the receive antenna with vegetation from jamming radio equipment. Moreover, vegetation resolves electromagnetic ecology issues, for the energy flux density can be lowered by about two orders of magnitude.

Application of hot melt extrusion for poorly water-soluble drugs: limitations, advances and future prospects.

PubMed

Lu, Ming; Guo, Zhefei; Li, Yongcheng; Pang, Huishi; Lin, Ling; Liu, Xu; Pan, Xin; Wu, Chuanbin

2014-01-01

Hot melt extrusion (HME) is a powerful technology to enhance the solubility and bioavailability of poorly water-soluble drugs by producing amorphous solid dispersions. Although the number of articles and patents about HME increased dramatically in the past twenty years, there are very few commercial products by far. The three main obstacles limiting the commercial application of HME are summarized as thermal degradation of heat-sensitive drugs at high process temperature, recrystallization of amorphous drugs during storage and dissolving process, and difficulty to obtain products with reproducible physicochemical properties. Many efforts have been taken in recent years to understand the basic mechanism underlying these obstacles and then to overcome them. This article reviewed and summarized the limitations, recent advances, and future prospects of HME.

A Feasible Approach for Implementing Greater Levels of Satellite Autonomy

NASA Astrophysics Data System (ADS)

Lindsay, Steve; Zetocha, Paul

2002-01-01

In this paper, we propose a means for achieving increasingly autonomous satellite operations. We begin with a brief discussion of the current state-of-the-art in satellite ground operations and flight software, as well as the real and perceived technical and political obstacles to increasing the levels of autonomy on today's satellites. We then present a list of system requirements that address these hindrances and include the artificial intelligence (AI) technologies with the potential to satisfy these requirements. We conclude with a discussion of how the space industry can use this information to incorporate increased autonomy. From past experience we know that autonomy will not just "happen," and we know that the expensive course of manually intensive operations simply cannot continue. Our goal is to present the aerospace industry with an analysis that will begin moving us in the direction of autonomous operations.

ACTS mobile propagation campaign

NASA Technical Reports Server (NTRS)

Goldhirsh, Julius; Vogel, Wolfhard J.; Torrence, Geoffrey W.

1994-01-01

Preliminary results are presented for three propagation measurement campaigns involving a mobile receiving laboratory and 20 GHz transmissions from the Advanced Communications Technology Satellite (ACTS). Four 1994 campaigns were executed during weekly periods in and around Austin, Texas in February and May, in Central Maryland during March, and in Fairbanks, Alaska and environs in June. Measurements tested the following effects at 20 GHz: (1) attenuation due to roadside trees with and without foliage, (2) multipath effects for scenarios in which line-of-sight paths were unshadowed, (3) fades due to terrain and roadside obstacles, (4) fades due to structures in urban environs, (5) single tree attenuation, and (6) effects of fading at low elevation angles (8 deg in Fairbanks, Alaska) and high elevation angles (55 deg in Austin, Texas). Results presented here cover sampled measurements in Austin, Texas for foliage and non-foliage cases and in Central Maryland for non-foliage runs.

Web-Based Instruction and Learning: Analysis and Needs Assessment

NASA Technical Reports Server (NTRS)

Grabowski, Barbara; McCarthy, Marianne; Koszalka, Tiffany

1998-01-01

An analysis and needs assessment was conducted to identify kindergarten through grade 14 (K-14) customer needs with regard to using the World Wide Web (WWW) for instruction and to identify obstacles K-14 teachers face in utilizing NASA Learning Technologies products in the classroom. The needs assessment was conducted as part of the Dryden Learning Technologies Project which is a collaboration between Dryden Flight Research Center (DFRC), Edwards, California and Tne Pennsylvania State University (PSU), University Park, Pennsylvania. The overall project is a multiyear effort to conduct research in the development of teacher training and tools for Web-based science, mathematics and technology instruction and learning.

Three-dimensional obstacle classification in laser range data

NASA Astrophysics Data System (ADS)

Armbruster, Walter; Bers, Karl-Heinz

1998-10-01

The threat of hostile surveillance and weapon systems require military aircraft to fly under extreme conditions such as low altitude, high speed, poor visibility and incomplete terrain information. The probability of collision with natural and man-made obstacles during such contour missions is high if detection capability is restricted to conventional vision aids. Forward-looking scanning laser rangefinders which are presently being flight tested and evaluated at German proving grounds, provide a possible solution, having a large field of view, high angular and range resolution, a high pulse repetition rate, and sufficient pulse energy to register returns from wires at over 500 m range (depends on the system) with a high hit-and-detect probability. Despite the efficiency of the sensor, acceptance of current obstacle warning systems by test pilots is not very high, mainly due to the systems' inadequacies in obstacle recognition and visualization. This has motivated the development and the testing of more advanced 3d-scene analysis algorithm at FGAN-FIM to replace the obstacle recognition component of current warning systems. The basic ideas are to increase the recognition probability and to reduce the false alarm rate for hard-to-extract obstacles such as wires, by using more readily recognizable objects such as terrain, poles, pylons, trees, etc. by implementing a hierarchical classification procedure to generate a parametric description of the terrain surface as well as the class, position, orientation, size and shape of all objects in the scene. The algorithms can be used for other applications such as terrain following, autonomous obstacle avoidance, and automatic target recognition.

Visualization of deflagration-to-detonation transitions in a channel with repeated obstacles using a hydrogen-oxygen mixture

NASA Astrophysics Data System (ADS)

Maeda, S.; Minami, S.; Okamoto, D.; Obara, T.

2016-09-01

The deflagration-to-detonation transition in a 100 mm square cross-section channel was investigated for a highly reactive stoichiometric hydrogen oxygen mixture at 70 kPa. Obstacles of 5 mm width and 5, 10, and 15 mm heights were equally spaced 60 mm apart at the bottom of the channel. The phenomenon was investigated primarily by time-resolved schlieren visualization from two orthogonal directions using a high-speed video camera. The detonation transition occurred over a remarkably short distance within only three or four repeated obstacles. The global flame speed just before the detonation transition was well below the sound speed of the combustion products and did not reach the sound speed of the initial unreacted gas for tests with an obstacle height of 5 and 10 mm. These results indicate that a detonation transition does not always require global flame acceleration beyond the speed of sound for highly reactive combustible mixtures. A possible mechanism for this detonation initiation was the mixing of the unreacted and reacted gas in the vicinity of the flame front convoluted by the vortex present behind each obstacle, and the formation of a hot spot by the shock wave. The final onset of the detonation originated from the unreacted gas pocket, which was surrounded by the obstacle downstream face and the channel wall.

Sensorimotor Model of Obstacle Avoidance in Echolocating Bats

PubMed Central

Vanderelst, Dieter; Holderied, Marc W.; Peremans, Herbert

2015-01-01

Bat echolocation is an ability consisting of many subtasks such as navigation, prey detection and object recognition. Understanding the echolocation capabilities of bats comes down to isolating the minimal set of acoustic cues needed to complete each task. For some tasks, the minimal cues have already been identified. However, while a number of possible cues have been suggested, little is known about the minimal cues supporting obstacle avoidance in echolocating bats. In this paper, we propose that the Interaural Intensity Difference (IID) and travel time of the first millisecond of the echo train are sufficient cues for obstacle avoidance. We describe a simple control algorithm based on the use of these cues in combination with alternating ear positions modeled after the constant frequency bat Rhinolophus rouxii. Using spatial simulations (2D and 3D), we show that simple phonotaxis can steer a bat clear from obstacles without performing a reconstruction of the 3D layout of the scene. As such, this paper presents the first computationally explicit explanation for obstacle avoidance validated in complex simulated environments. Based on additional simulations modelling the FM bat Phyllostomus discolor, we conjecture that the proposed cues can be exploited by constant frequency (CF) bats and frequency modulated (FM) bats alike. We hypothesize that using a low level yet robust cue for obstacle avoidance allows bats to comply with the hard real-time constraints of this basic behaviour. PMID:26502063

Technical Assessment: Integrated Photonics

DTIC Science & Technology

2015-10-01

in global internet protocol traffic as a function of time by local access technology. Photonics continues to play a critical role in enabling this...communication networks. This has enabled services like the internet , high performance computing, and power-efficient large-scale data centers. The...signal processing, quantum information science, and optics for free space applications. However major obstacles challenge the implementation of

A Systematic Approach to Faculty Development toward Improved Capability in Tertiary Teaching in a Blended Learning Environment

ERIC Educational Resources Information Center

Badawood, Ashraf Mohammad

2011-01-01

The blended learning (BL) approach provides an efficient and effective instructional experience. However, adopting BL poses some challenge to faculty; the most important obstacle found in this research is faculty's lack of knowledge regarding the use of technology in their teaching. This challenge prompted the researcher to identify a solution…

Older Computer-Literate Women: Their Motivations, Obstacles, and Paths to Success

ERIC Educational Resources Information Center

Rosenthal, Rita L.

2008-01-01

With the ever-increasing impact of computerized communication and information delivery, the need to encourage learning about technology is critical for the older population today as well as for soon-to-be retirees. Adler (1996, 2002, 2003) has described and defined the key benefits to seniors: enhanced communication with family and friends,…

Electronic Health Records: Overcoming Obstacles to Improve Acceptance and Utilization for Mental Health Clinicians

ERIC Educational Resources Information Center

Odom, Stephen A.

2017-01-01

The dynamics and progress of the integration of the electronic health record (EHR) into health-care disciplines have been described and examined using theories related to technology adoption. Previous studies have examined health-care clinician resistance to the EHR in primary care, hospital, and urgent care medical settings, but few studies have…

The Central Role of Expectations in Communication and Literacy Success: A Parent Perspective

ERIC Educational Resources Information Center

Mintun, Bonnie

2005-01-01

The author chronicles the search for augmentative and alternative communication (AAC) technology for her daughter Anna, who is now age 21. Though Anna has severe cognitive, visual and orthopedic disabilities, a more significant obstacle to finding a functional AAC system has been low expectations of her capability. Because Anna could not perform…

Technology as Arts-Based Education: Does the Desktop Reflect the Arts?

ERIC Educational Resources Information Center

Gouzouasis, Peter

2006-01-01

Since the dawn of time, human imagination has resulted in creating extensions of self (that is, tools) as a means to overcome obstacles produced by genetic limits. Whether the tool extends thought or sense; whether the tool is organic, such as language, or inorganic; and whether electronic, digital, or analog, the artist plies the science or…

Location Does Not Have to Be Destiny: Student Evaluation and Integrity Controls in a Management Accounting Class

ERIC Educational Resources Information Center

Goldwater, Paul M.; Fogarty, Timothy J.

2012-01-01

As accounting education transitions to more distance-learning formats, the integrity of student evaluation continues to serve as an obstacle to adoption. Greater technological possibilities will be opposed if faculty members believe that testing is compromised. This article investigates whether students taking exams remotely (and under no…

Issues of ICT Usage among Malaysian Secondary School English Teachers

ERIC Educational Resources Information Center

Raman, Arumugam; Mohamed, Abdul Halim

2013-01-01

This study explored on perception, usage and obstacles of using ICT in teaching English Language among secondary school English teachers. The advancement of technology has given a space for teachers to boost teaching and learning of English language in secondary schools. It is believed that integration of ICT could enhance quality of teaching and…

Identifying and Remediating Student Misconceptions in Introductory Biology via Writing-to-Learn Assignments and Peer Review

ERIC Educational Resources Information Center

Halim, Audrey S.; Finkenstaedt-Quinn, Solaire A.; Olsen, Laura J.; Gere, Anne Ruggles; Shultz, Ginger V.

2018-01-01

Student misconceptions are an obstacle in science, technology, engineering, and mathematics courses and unless remediated may continue causing difficulties in learning as students advance in their studies. Writing-to-learn assignments (WTL) are characterized by their ability to promote in-depth conceptual learning by allowing students to explore…

Working with Your Local School District: A Tale of Two Cities

ERIC Educational Resources Information Center

Moore, Andrea K.; Kaminski, Jerome M.

2011-01-01

This article follows the events and obstacles of two International Society for Performance Improvement members as they traverse the education community in pursuit of applying human performance technology into their system. The story is a work in progress with definitive direction as well as tips and insight to others wishing to make an impact in…

A Virtual Blind Cane Using a Line Laser-Based Vision System and an Inertial Measurement Unit

PubMed Central

Dang, Quoc Khanh; Chee, Youngjoon; Pham, Duy Duong; Suh, Young Soo

2016-01-01

A virtual blind cane system for indoor application, including a camera, a line laser and an inertial measurement unit (IMU), is proposed in this paper. Working as a blind cane, the proposed system helps a blind person find the type of obstacle and the distance to it. The distance from the user to the obstacle is estimated by extracting the laser coordinate points on the obstacle, as well as tracking the system pointing angle. The paper provides a simple method to classify the obstacle’s type by analyzing the laser intersection histogram. Real experimental results are presented to show the validity and accuracy of the proposed system. PMID:26771618

Interaction dynamics of multiple autonomous mobile robots in bounded spatial domains

NASA Technical Reports Server (NTRS)

Wang, P. K. C.

1989-01-01

A general navigation strategy for multiple autonomous robots in a bounded domain is developed analytically. Each robot is modeled as a spherical particle (i.e., an effective spatial domain about the center of mass); its interactions with other robots or with obstacles and domain boundaries are described in terms of the classical many-body problem; and a collision-avoidance strategy is derived and combined with homing, robot-robot, and robot-obstacle collision-avoidance strategies. Results from homing simulations involving (1) a single robot in a circular domain, (2) two robots in a circular domain, and (3) one robot in a domain with an obstacle are presented in graphs and briefly characterized.

Time-dependent perpendicular fluctuations in the driven lattice Lorentz gas

NASA Astrophysics Data System (ADS)

Leitmann, Sebastian; Schwab, Thomas; Franosch, Thomas

2018-02-01

We present results for the fluctuations of the displacement of a tracer particle on a planar lattice pulled by a step force in the presence of impenetrable, immobile obstacles. The fluctuations perpendicular to the applied force are evaluated exactly in first order of the obstacle density for arbitrarily strong pulling and all times. The complex time-dependent behavior is analyzed in terms of the diffusion coefficient, local exponent, and the non-Skellam parameter, which quantifies deviations from the dynamics on the lattice in the absence of obstacles. The non-Skellam parameter along the force is analyzed in terms of an asymptotic model and reveals a power-law growth for intermediate times.

Cost-effective, transfer-free, flexible resistive random access memory using laser-scribed reduced graphene oxide patterning technology.

PubMed

Tian, He; Chen, Hong-Yu; Ren, Tian-Ling; Li, Cheng; Xue, Qing-Tang; Mohammad, Mohammad Ali; Wu, Can; Yang, Yi; Wong, H-S Philip

2014-06-11

Laser scribing is an attractive reduced graphene oxide (rGO) growth and patterning technology because the process is low-cost, time-efficient, transfer-free, and flexible. Various laser-scribed rGO (LSG) components such as capacitors, gas sensors, and strain sensors have been demonstrated. However, obstacles remain toward practical application of the technology where all the components of a system are fabricated using laser scribing. Memory components, if developed, will substantially broaden the application space of low-cost, flexible electronic systems. For the first time, a low-cost approach to fabricate resistive random access memory (ReRAM) using laser-scribed rGO as the bottom electrode is experimentally demonstrated. The one-step laser scribing technology allows transfer-free rGO synthesis directly on flexible substrates or non-flat substrates. Using this time-efficient laser-scribing technology, the patterning of a memory-array area up to 100 cm(2) can be completed in 25 min. Without requiring the photoresist coating for lithography, the surface of patterned rGO remains as clean as its pristine state. Ag/HfOx/LSG ReRAM using laser-scribing technology is fabricated in this work. Comprehensive electrical characteristics are presented including forming-free behavior, stable switching, reasonable reliability performance and potential for 2-bit storage per memory cell. The results suggest that laser-scribing technology can potentially produce more cost-effective and time-effective rGO-based circuits and systems for practical applications.

From the Chemistry Lab to Licensing

NASA Technical Reports Server (NTRS)

Savino, Joseph M.; Street, Kenneth W.; Philipp, Warren H.

1998-01-01

This is a story of technology maturation and transfer, and licensing. It traces the history of the recently patented ion- exchange material (IEM) from the accidental discovery that this polymer, a battery separator of marginal performance, picked up copper from distilled water passing through corroded copper tubing in the laboratory, to a point where five organizations and one individual have applied for licenses to manufacture and market it or to use it in a wide variety of applications. This story discusses in detail the problems of converting an immature technology into a mature and eventually commercialized technology, without dedicated resources. Readers will develop an appreciation for how the obstacles to maturation and licensing of the technology were faced and overcome. The lessons learned will be discussed, with the hope of enhancing the technology transfer process.

Safe Maritime Navigation with COLREGS Using Velocity Obstacles

NASA Technical Reports Server (NTRS)

Kuwata, Yoshiaki; Wolf, Michael T.; Zarzhitsky, Dimitri; Huntsberger, Terrance L.

2011-01-01

This paper presents a motion planning algorithm for Unmanned Surface Vehicles (USVs) to navigate safely in dynamic, cluttered environments. The proposed algorithm not only addresses Hazard Avoidance (HA) for stationary and moving hazards but also applies the International Regulations for Preventing Collisions at Sea (known as COLREGs). The COLREG rules specify, for example, which vessel is responsible for giving way to the other and to which side of the "stand-on" vessel to maneuver. The three primary COLREG rules were considered in this paper: crossing, overtaking, and head-on situations. For USVs to be safely deployed in environments with other traffic boats, it is imperative that the USV's navigation algorithm obey COLREGs. Note also that if other boats disregard their responsibility under COLREGs, the USV will still apply its HA algorithms to avoid a collision. The proposed approach is based on Velocity Obstacles, which generates a cone-shaped obstacle in the velocity space. Because Velocity Obstacles also specify which side of the obstacle the vehicle will pass during the avoidance maneuver, COLREGs are encoded in the velocity space in a natural way. The algorithm is demonstrated via both simulation and on-water tests.

Flow through a very porous obstacle in a shallow channel.

PubMed

Creed, M J; Draper, S; Nishino, T; Borthwick, A G L

2017-04-01

A theoretical model, informed by numerical simulations based on the shallow water equations, is developed to predict the flow passing through and around a uniform porous obstacle in a shallow channel, where background friction is important. This problem is relevant to a number of practical situations, including flow through aquatic vegetation, the performance of arrays of turbines in tidal channels and hydrodynamic forces on offshore structures. To demonstrate this relevance, the theoretical model is used to (i) reinterpret core flow velocities in existing laboratory-based data for an array of emergent cylinders in shallow water emulating aquatic vegetation and (ii) reassess the optimum arrangement of tidal turbines to generate power in a tidal channel. Comparison with laboratory-based data indicates a maximum obstacle resistance (or minimum porosity) for which the present theoretical model is valid. When the obstacle resistance is above this threshold the shallow water equations do not provide an adequate representation of the flow, and the theoretical model over-predicts the core flow passing through the obstacle. The second application of the model confirms that natural bed resistance increases the power extraction potential for a partial tidal fence in a shallow channel and alters the optimum arrangement of turbines within the fence.

Evaluation of Mental Workload among ICU Ward's Nurses.

PubMed

Mohammadi, Mohsen; Mazloumi, Adel; Kazemi, Zeinab; Zeraati, Hojat

2015-01-01

High level of workload has been identified among stressors of nurses in intensive care units (ICUs). The present study investigated nursing workload and identified its influencing perfor-mance obstacles in ICUs. This cross-sectional study was conducted, in 2013, on 81 nurses working in ICUs in Imam Khomeini Hospital in Tehran, Iran. NASA-TLX was applied for assessment of workload. Moreover, ICUs Performance Obstacles Questionnaire was used to identify performance obstacles associated with ICU nursing. Physical demand (mean=84.17) was perceived as the most important dimensions of workload by nurses. The most critical performance obstacles affecting workload included: difficulty in finding a place to sit down, hectic workplace, disorganized workplace, poor-conditioned equipment, waiting for using a piece of equipment, spending much time seeking for supplies in the central stock, poor quality of medical materials, delay in getting medications, unpredicted problems, disorganized central stock, outpatient surgery, spending much time dealing with family needs, late, inadequate, and useless help from nurse assistants, and ineffective morning rounds (P-value<0.05). Various performance obstacles are correlated with nurses' workload, affirms the significance of nursing work system characteristics. Interventions are recommended based on the results of this study in the work settings of nurses in ICUs.

3D-Sonification for Obstacle Avoidance in Brownout Conditions

NASA Technical Reports Server (NTRS)

Godfroy-Cooper, M.; Miller, J. D.; Szoboszlay, Z.; Wenzel, E. M.

2017-01-01

Helicopter brownout is a phenomenon that occurs when making landing approaches in dusty environments, whereby sand or dust particles become swept up in the rotor outwash. Brownout is characterized by partial or total obscuration of the terrain, which degrades visual cues necessary for hovering and safe landing. Furthermore, the motion of the dust cloud produced during brownout can lead to the pilot experiencing motion cue anomalies such as vection illusions. In this context, the stability and guidance control functions can be intermittently or continuously degraded, potentially leading to undetected surface hazards and obstacles as well as unnoticed drift. Safe and controlled landing in brownout can be achieved using an integrated presentation of LADAR and RADAR imagery and aircraft state symbology. However, though detected by the LADAR and displayed on the sensor image, small obstacles can be difficult to discern from the background so that changes in obstacle elevation may go unnoticed. Moreover, pilot workload associated with tracking the displayed symbology is often so high that the pilot cannot give sufficient attention to the LADAR/RADAR image. This paper documents a simulation evaluating the use of 3D auditory cueing for obstacle avoidance in brownout as a replacement for or compliment to LADAR/RADAR imagery.

Doing science, technology and society in the National Science Foundation : commentary on: "Engaged, embedded, enjoined: science and technology studies in the National Science Foundation".

PubMed

Gorman, Michael E

2011-12-01

The author describes his efforts to become a participant observer while he was a Program Director at the NSF. He describes his plans for keeping track of his reflections and his goals before he arrived at NSF, then includes sections from his reflective diary and comments after he had completed his two-year rotation. The influx of rotators means the NSF has to be an adaptive, learning organization but there are bureaucratic obstacles in the way.

Managing the patent thicket and maximizing patent lifetime in vaccine technology.

PubMed

Mertes, Maria M M; Stötter, Gerd

2010-10-01

Patents are exclusive rights for a limited period of time that are granted to provide an incentive for innovation and in exchange for the public disclosure of an invention. Patenting in the medical field, especially in the field of human vaccine technologies, is full of pitfalls, because the products that finally access the market are often covered by a multitude of exclusive IP rights. This commentary gives an overview on obstacles in vaccine patenting and how to overcome them, and intends to provide a patenting guideline for researchers.

Educational pathways of Black women physicists: Stories of experiencing and overcoming obstacles in life

NASA Astrophysics Data System (ADS)

Rosa, Katemari

2017-01-01

This talk presents an empirical study on the underrepresentation of people of color in scientific careers. Grounded in Critical Race Theory, the presentation examines the lived experiences of six Black women physicists in the United States, addresses obstacles faced in their career paths, and strategies used to overcome these obstacles. Data for this study were collected through semi-structured interviews and coded for emergent themes, which are invitation to engage in science, communities of science practices, and isolation in the academy. The findings reveal that college recruitment and funding were fundamental for these women to choose Physics over other STEM fields. The analysis shows Physics can be a hostile environment for these women. In addition, Black women experience unique challenges of socialization in Physics, particularly by exclusion of study groups. In this talk, suggestions will be presented to make Physics departments a more inclusive space to support Black women in science. This presentation is based on work supported by the Brazilian government through CAPES (BEX1907-07-7), the Fulbright Program, Comissño Fulbright Brasil, and the Office of Diversity at Teachers College, Columbia University.

Bridging the Divide between Neuroprosthetic Design, Tissue Engineering and Neurobiology

PubMed Central

Leach, Jennie B.; Achyuta, Anil Kumar H.; Murthy, Shashi K.

2009-01-01

Neuroprosthetic devices have made a major impact in the treatment of a variety of disorders such as paralysis and stroke. However, a major impediment in the advancement of this technology is the challenge of maintaining device performance during chronic implantation (months to years) due to complex intrinsic host responses such as gliosis or glial scarring. The objective of this review is to bring together research communities in neurobiology, tissue engineering, and neuroprosthetics to address the major obstacles encountered in the translation of neuroprosthetics technology into long-term clinical use. This article draws connections between specific challenges faced by current neuroprosthetics technology and recent advances in the areas of nerve tissue engineering and neurobiology. Within the context of the device–nervous system interface and central nervous system implants, areas of synergistic opportunity are discussed, including platforms to present cells with multiple cues, controlled delivery of bioactive factors, three-dimensional constructs and in vitro models of gliosis and brain injury, nerve regeneration strategies, and neural stem/progenitor cell biology. Finally, recent insights gained from the fields of developmental neurobiology and cancer biology are discussed as examples of exciting new biological knowledge that may provide fresh inspiration toward novel technologies to address the complexities associated with long-term neuroprosthetic device performance. PMID:20161810

Space Commerce 1994 Forum: The 10th National Space Symposium. Proceedings report

NASA Astrophysics Data System (ADS)

Lipskin, Beth Ann; Patterson, Sara; Aragon, Larry; Brescia, David A.; Flannery, Jack; Mossey, Roberty; Regan, Christopher; Steeby, Kurt; Suhr, Stacy; Zimkas, Chuck

1994-04-01

The theme of the 10th National Space Symposium was 'New Windows of Opportunity'. These proceedings cover the following: Business Trends in High Tech Commercialization; How to Succeed in Space Technology Business -- Making Dollars and Sense; Obstacles and Opportunities to Success in Technology Commercialization NASA's Commercial Technology Mission -- a New Way of Doing Business: Policy and Practices; Field Center Practices; Practices in Action -- A New Way: Implementation and Business Opportunities; Space Commerce Review; Windows of Opportunity; the International Space Station; Space Support Forum; Spacelift Update; Competitive Launch Capabilities; Supporting Life on Planet Earth; National Security Space Issues; NASA in the Balance; Earth and Space Observations -- Did We Have Cousins on Mars?; NASA: A New Vision for Science; and Space Technology Hall of Fame.

Space Commerce 1994 Forum: The 10th National Space Symposium. Proceedings report

NASA Technical Reports Server (NTRS)

Lipskin, Beth Ann (Editor); Patterson, Sara (Editor); Aragon, Larry (Editor); Brescia, David A. (Editor); Flannery, Jack (Editor); Mossey, Roberty (Editor); Regan, Christopher (Editor); Steeby, Kurt (Editor); Suhr, Stacy (Editor); Zimkas, Chuck (Editor)

1994-01-01

The theme of the 10th National Space Symposium was 'New Windows of Opportunity'. These proceedings cover the following: Business Trends in High Tech Commercialization; How to Succeed in Space Technology Business -- Making Dollars and Sense; Obstacles and Opportunities to Success in Technology Commercialization NASA's Commercial Technology Mission -- a New Way of Doing Business: Policy and Practices; Field Center Practices; Practices in Action -- A New Way: Implementation and Business Opportunities; Space Commerce Review; Windows of Opportunity; the International Space Station; Space Support Forum; Spacelift Update; Competitive Launch Capabilities; Supporting Life on Planet Earth; National Security Space Issues; NASA in the Balance; Earth and Space Observations -- Did We Have Cousins on Mars?; NASA: A New Vision for Science; and Space Technology Hall of Fame.

Supporting research sites in resource-limited settings: challenges in implementing information technology infrastructure.

PubMed

Whalen, Christopher J; Donnell, Deborah; Tartakovsky, Michael

2014-01-01

As information and communication technology infrastructure becomes more reliable, new methods of electronic data capture, data marts/data warehouses, and mobile computing provide platforms for rapid coordination of international research projects and multisite studies. However, despite the increasing availability of Internet connectivity and communication systems in remote regions of the world, there are still significant obstacles. Sites with poor infrastructure face serious challenges participating in modern clinical and basic research, particularly that relying on electronic data capture and Internet communication technologies. This report discusses our experiences in supporting research in resource-limited settings. We describe examples of the practical and ethical/regulatory challenges raised by the use of these newer technologies for data collection in multisite clinical studies.

Dynamic Distributed Cooperative Control of Multiple Heterogeneous Resources

DTIC Science & Technology

2012-10-01

of the UAVs to maximize the total sensor footprint over the region of interest. The algorithm utilized to solve this problem was based on sampling a...and moving obstacles. Obstacle positions were assumed known a priori. Kingston and Beard [22] presented an algorithm to keep moving UAVs equally spaced...Planning Algorithms , Cambridge University Press, 2006. 11. Ma, C. S. and Miller, R. H., “Mixed integer linear programming trajectory generation for

Thermal activation of dislocations in large scale obstacle bypass

NASA Astrophysics Data System (ADS)

Sobie, Cameron; Capolungo, Laurent; McDowell, David L.; Martinez, Enrique

2017-08-01

Dislocation dynamics simulations have been used extensively to predict hardening caused by dislocation-obstacle interactions, including irradiation defect hardening in the athermal case. Incorporating the role of thermal energy on these interactions is possible with a framework provided by harmonic transition state theory (HTST) enabling direct access to thermally activated reaction rates using the Arrhenius equation, including rates of dislocation-obstacle bypass processes. Moving beyond unit dislocation-defect reactions to a representative environment containing a large number of defects requires coarse-graining the activation energy barriers of a population of obstacles into an effective energy barrier that accurately represents the large scale collective process. The work presented here investigates the relationship between unit dislocation-defect bypass processes and the distribution of activation energy barriers calculated for ensemble bypass processes. A significant difference between these cases is observed, which is attributed to the inherent cooperative nature of dislocation bypass processes. In addition to the dislocation-defect interaction, the morphology of the dislocation segments pinned to the defects play an important role on the activation energies for bypass. A phenomenological model for activation energy stress dependence is shown to describe well the effect of a distribution of activation energies, and a probabilistic activation energy model incorporating the stress distribution in a material is presented.

Suppression of emission rates improves sonar performance by flying bats.

PubMed

Adams, Amanda M; Davis, Kaylee; Smotherman, Michael

2017-01-31

Echolocating bats face the challenge of actively sensing their environment through their own emissions, while also hearing calls and echoes of nearby conspecifics. How bats mitigate interference is a long-standing question that has both ecological and technological implications, as biosonar systems continue to outperform man-made sonar systems in noisy, cluttered environments. We recently showed that perched bats decreased calling rates in groups, displaying a behavioral strategy resembling the back-off algorithms used in artificial communication networks to optimize information throughput at the group level. We tested whether free-tailed bats (Tadarida brasiliensis) would employ such a coordinated strategy while performing challenging flight maneuvers, and report here that bats navigating obstacles lowered emission rates when hearing artificial playback of another bat's calls. We measured the impact of acoustic interference on navigation performance and show that the calculated reductions in interference rates are sufficient to reduce interference and improve obstacle avoidance. When bats flew in pairs, each bat responded to the presence of the other as an obstacle by increasing emissions, but hearing the sonar emissions of the nearby bat partially suppressed this response. This behavior supports social cohesion by providing a key mechanism for minimizing mutual interference.

Suppression of emission rates improves sonar performance by flying bats

PubMed Central

Adams, Amanda M.; Davis, Kaylee; Smotherman, Michael

2017-01-01

Echolocating bats face the challenge of actively sensing their environment through their own emissions, while also hearing calls and echoes of nearby conspecifics. How bats mitigate interference is a long-standing question that has both ecological and technological implications, as biosonar systems continue to outperform man-made sonar systems in noisy, cluttered environments. We recently showed that perched bats decreased calling rates in groups, displaying a behavioral strategy resembling the back-off algorithms used in artificial communication networks to optimize information throughput at the group level. We tested whether free-tailed bats (Tadarida brasiliensis) would employ such a coordinated strategy while performing challenging flight maneuvers, and report here that bats navigating obstacles lowered emission rates when hearing artificial playback of another bat’s calls. We measured the impact of acoustic interference on navigation performance and show that the calculated reductions in interference rates are sufficient to reduce interference and improve obstacle avoidance. When bats flew in pairs, each bat responded to the presence of the other as an obstacle by increasing emissions, but hearing the sonar emissions of the nearby bat partially suppressed this response. This behavior supports social cohesion by providing a key mechanism for minimizing mutual interference. PMID:28139707

Application of Optical Flow Sensors for Dead Reckoning, Heading Reference, Obstacle Detection, and Obstacle Avoidance

DTIC Science & Technology

2015-09-01

OPTICAL FLOW SENSORS FOR DEAD RECKONING, HEADING REFERENCE, OBSTACLE DETECTION, AND OBSTACLE AVOIDANCE by Tarek M. Nejah September 2015...SENSORS FOR DEAD RECKONING, HEADING REFERENCE, OBSTACLE DETECTION, AND OBSTACLE AVOIDANCE 5. FUNDING NUMBERS 6. AUTHOR(S) Nejah, Tarek M. 7...DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) A novel approach for dead reckoning, heading reference, obstacle detection, and obstacle

Bim-Based Indoor Path Planning Considering Obstacles

NASA Astrophysics Data System (ADS)

Xu, M.; Wei, S.; Zlatanova, S.; Zhang, R.

2017-09-01

At present, 87 % of people's activities are in indoor environment; indoor navigation has become a research issue. As the building structures for people's daily life are more and more complex, many obstacles influence humans' moving. Therefore it is essential to provide an accurate and efficient indoor path planning. Nowadays there are many challenges and problems in indoor navigation. Most existing path planning approaches are based on 2D plans, pay more attention to the geometric configuration of indoor space, often ignore rich semantic information of building components, and mostly consider simple indoor layout without taking into account the furniture. Addressing the above shortcomings, this paper uses BIM (IFC) as the input data and concentrates on indoor navigation considering obstacles in the multi-floor buildings. After geometric and semantic information are extracted, 2D and 3D space subdivision methods are adopted to build the indoor navigation network and to realize a path planning that avoids obstacles. The 3D space subdivision is based on triangular prism. The two approaches are verified by the experiments.

On computing the global time-optimal motions of robotic manipulators in the presence of obstacles

NASA Technical Reports Server (NTRS)

Shiller, Zvi; Dubowsky, Steven

1991-01-01

A method for computing the time-optimal motions of robotic manipulators is presented that considers the nonlinear manipulator dynamics, actuator constraints, joint limits, and obstacles. The optimization problem is reduced to a search for the time-optimal path in the n-dimensional position space. A small set of near-optimal paths is first efficiently selected from a grid, using a branch and bound search and a series of lower bound estimates on the traveling time along a given path. These paths are further optimized with a local path optimization to yield the global optimal solution. Obstacles are considered by eliminating the collision points from the tessellated space and by adding a penalty function to the motion time in the local optimization. The computational efficiency of the method stems from the reduced dimensionality of the searched spaced and from combining the grid search with a local optimization. The method is demonstrated in several examples for two- and six-degree-of-freedom manipulators with obstacles.

Integrating Millimeter Wave Radar with a Monocular Vision Sensor for On-Road Obstacle Detection Applications

PubMed Central

Wang, Tao; Zheng, Nanning; Xin, Jingmin; Ma, Zheng

2011-01-01

This paper presents a systematic scheme for fusing millimeter wave (MMW) radar and a monocular vision sensor for on-road obstacle detection. As a whole, a three-level fusion strategy based on visual attention mechanism and driver’s visual consciousness is provided for MMW radar and monocular vision fusion so as to obtain better comprehensive performance. Then an experimental method for radar-vision point alignment for easy operation with no reflection intensity of radar and special tool requirements is put forward. Furthermore, a region searching approach for potential target detection is derived in order to decrease the image processing time. An adaptive thresholding algorithm based on a new understanding of shadows in the image is adopted for obstacle detection, and edge detection is used to assist in determining the boundary of obstacles. The proposed fusion approach is verified through real experimental examples of on-road vehicle/pedestrian detection. In the end, the experimental results show that the proposed method is simple and feasible. PMID:22164117

Integrating millimeter wave radar with a monocular vision sensor for on-road obstacle detection applications.

PubMed

Wang, Tao; Zheng, Nanning; Xin, Jingmin; Ma, Zheng

2011-01-01

This paper presents a systematic scheme for fusing millimeter wave (MMW) radar and a monocular vision sensor for on-road obstacle detection. As a whole, a three-level fusion strategy based on visual attention mechanism and driver's visual consciousness is provided for MMW radar and monocular vision fusion so as to obtain better comprehensive performance. Then an experimental method for radar-vision point alignment for easy operation with no reflection intensity of radar and special tool requirements is put forward. Furthermore, a region searching approach for potential target detection is derived in order to decrease the image processing time. An adaptive thresholding algorithm based on a new understanding of shadows in the image is adopted for obstacle detection, and edge detection is used to assist in determining the boundary of obstacles. The proposed fusion approach is verified through real experimental examples of on-road vehicle/pedestrian detection. In the end, the experimental results show that the proposed method is simple and feasible.

On autonomous terrain model acquistion by a mobile robot

NASA Technical Reports Server (NTRS)

Rao, N. S. V.; Iyengar, S. S.; Weisbin, C. R.

1987-01-01

The following problem is considered: A point robot is placed in a terrain populated by an unknown number of polyhedral obstacles of varied sizes and locations in two/three dimensions. The robot is equipped with a sensor capable of detecting all the obstacle vertices and edges that are visible from the present location of the robot. The robot is required to autonomously navigate and build the complete terrain model using the sensor information. It is established that the necessary number of scanning operations needed for complete terrain model acquisition by any algorithm that is based on scan from vertices strategy is given by the summation of i = 1 (sup n) N(O sub i)-n and summation of i = 1 (sup n) N(O sub i)-2n in two- and three-dimensional terrains respectively, where O = (O sub 1, O sub 2,....O sub n) set of the obstacles in the terrain, and N(O sub i) is the number of vertices of the obstacle O sub i.

UAV formation control design with obstacle avoidance in dynamic three-dimensional environment.

PubMed

Chang, Kai; Xia, Yuanqing; Huang, Kaoli

2016-01-01

This paper considers the artificial potential field method combined with rotational vectors for a general problem of multi-unmanned aerial vehicle (UAV) systems tracking a moving target in dynamic three-dimensional environment. An attractive potential field is generated between the leader and the target. It drives the leader to track the target based on the relative position of them. The other UAVs in the formation are controlled to follow the leader by the attractive control force. The repulsive force affects among the UAVs to avoid collisions and distribute the UAVs evenly on the spherical surface whose center is the leader-UAV. Specific orders or positions of the UAVs are not required. The trajectories of avoidance obstacle can be obtained through two kinds of potential field with rotation vectors. Every UAV can choose the optimal trajectory to avoid the obstacle and reconfigure the formation after passing the obstacle. Simulations study on UAV are presented to demonstrate the effectiveness of proposed method.

Stepping over obstacles: gait patterns of healthy young and old adults.

PubMed

Chen, H C; Ashton-Miller, J A; Alexander, N B; Schultz, A B

1991-11-01

Falls associated with tripping over an obstacle can be devastating to elderly individuals, yet little is known about the strategies used for stepping over obstacles by either old or young adults. The gait of gender-matched groups of 24 young and 24 old healthy adults (mean ages 22 and 71 years) was studied during a 4 m approach to and while stepping over obstacles of 0, 25, 51, or 152 mm height and in level obstacle-free walking. Optoelectronic cameras and recorders were used to record approach and obstacle crossing speeds as well as bilateral lower extremity kinematic parameters that described foot placement and movement trajectories relative to the obstacle. The results showed that age had no effect on minimum swing foot clearance (FC) over an obstacle. For the 25 mm obstacle, mean FC was 64 mm, or approximately three times that used in level gait; FC increased nonlinearly with obstacle height for all subjects. Although no age differences were found in obstacle-free gait, old adults exhibited a significantly more conservative strategy when crossing obstacles, with slower crossing speed, shorter step length, and shorter obstacle-heel strike distance. In addition, the old adults crossed the obstacle so that it was 10% further forward in their obstacle-crossing step. Although all subjects successfully avoided the riskiest form of obstacle contact, tripping, 4/24 healthy old adults stepped on an obstacle, demonstrating an increased risk for obstacle contact with age.

Assessing gait adaptability in people with a unilateral amputation on an instrumented treadmill with a projected visual context.

PubMed

Houdijk, Han; van Ooijen, Mariëlle W; Kraal, Jos J; Wiggerts, Henri O; Polomski, Wojtek; Janssen, Thomas W J; Roerdink, Melvyn

2012-11-01

Gait adaptability, including the ability to avoid obstacles and to take visually guided steps, is essential for safe movement through a cluttered world. This aspect of walking ability is important for regaining independent mobility but is difficult to assess in clinical practice. The objective of this study was to investigate the validity of an instrumented treadmill with obstacles and stepping targets projected on the belt's surface for assessing prosthetic gait adaptability. This was an observational study. A control group of people who were able bodied (n=12) and groups of people with transtibial (n=12) and transfemoral (n=12) amputations participated. Participants walked at a self-selected speed on an instrumented treadmill with projected visual obstacles and stepping targets. Gait adaptability was evaluated in terms of anticipatory and reactive obstacle avoidance performance (for obstacles presented 4 steps and 1 step ahead, respectively) and accuracy of stepping on regular and irregular patterns of stepping targets. In addition, several clinical tests were administered, including timed walking tests and reports of incidence of falls and fear of falling. Obstacle avoidance performance and stepping accuracy were significantly lower in the groups with amputations than in the control group. Anticipatory obstacle avoidance performance was moderately correlated with timed walking test scores. Reactive obstacle avoidance performance and stepping accuracy performance were not related to timed walking tests. Gait adaptability scores did not differ in groups stratified by incidence of falls or fear of falling. Because gait adaptability was affected by walking speed, differences in self-selected walking speed may have diminished differences in gait adaptability between groups. Gait adaptability can be validly assessed by use of an instrumented treadmill with a projected visual context. When walking speed is taken into account, this assessment provides unique, quantitative information about walking ability in people with a lower-limb amputation.

Online optimal obstacle avoidance for rotary-wing autonomous unmanned aerial vehicles

NASA Astrophysics Data System (ADS)

Kang, Keeryun

This thesis presents an integrated framework for online obstacle avoidance of rotary-wing unmanned aerial vehicles (UAVs), which can provide UAVs an obstacle field navigation capability in a partially or completely unknown obstacle-rich environment. The framework is composed of a LIDAR interface, a local obstacle grid generation, a receding horizon (RH) trajectory optimizer, a global shortest path search algorithm, and a climb rate limit detection logic. The key feature of the framework is the use of an optimization-based trajectory generation in which the obstacle avoidance problem is formulated as a nonlinear trajectory optimization problem with state and input constraints over the finite range of the sensor. This local trajectory optimization is combined with a global path search algorithm which provides a useful initial guess to the nonlinear optimization solver. Optimization is the natural process of finding the best trajectory that is dynamically feasible, safe within the vehicle's flight envelope, and collision-free at the same time. The optimal trajectory is continuously updated in real time by the numerical optimization solver, Nonlinear Trajectory Generation (NTG), which is a direct solver based on the spline approximation of trajectory for dynamically flat systems. In fact, the overall approach of this thesis to finding the optimal trajectory is similar to the model predictive control (MPC) or the receding horizon control (RHC), except that this thesis followed a two-layer design; thus, the optimal solution works as a guidance command to be followed by the controller of the vehicle. The framework is implemented in a real-time simulation environment, the Georgia Tech UAV Simulation Tool (GUST), and integrated in the onboard software of the rotary-wing UAV test-bed at Georgia Tech. Initially, the 2D vertical avoidance capability of real obstacles was tested in flight. The flight test evaluations were extended to the benchmark tests for 3D avoidance capability over the virtual obstacles, and finally it was demonstrated on real obstacles located at the McKenna MOUT site in Fort Benning, Georgia. Simulations and flight test evaluations demonstrate the feasibility of the developed framework for UAV applications involving low-altitude flight in an urban area.

Impact of gender-based career obstacles on the working status of women physicians in Japan.

PubMed

Nomura, Kyoko; Gohchi, Kengo

2012-11-01

Research has shown that women physicians work fewer hours and are more likely to become inactive professionally and to switch to part-time labor, compared with their male counterparts. The published literature suggests that a gender disparity still exists in medicine which may decrease work motivation among women physicians. The authors investigated whether the experience and the perception of gender-based career obstacles among women physicians in Japan are associated with their working status (i.e., full-time vs. part-time). The present cross-sectional study is based on surveys of alumnae from 13 private medical schools in Japan conducted between June 2009 and May 2011. Of those who agreed to participate in this study, 1684 completed a self-administered questionnaire (overall response rate 83%). Experience of gender-based obstacles was considered affirmative if a woman physician had been overlooked for opportunities of professional advancement based on gender. Perception of gender-based obstacles referred to the self-reported degree of difficulty of promotion and opportunities for a position in higher education. Approximately 20% of the study participants responded that they experienced gender-based obstacles while 24% answered that they were not sure. The scores for perception of gender-based career obstacles were statistically higher among part-time workers compared with full-time workers (mean difference = 1.20, 95% CI: 0.39-2.00). Adjusting for age, marital status, the presence of children, workplace, board certification, holding a PhD degree, overall satisfaction of being a physician, and household income, stepwise logistic regression models revealed that physicians with the strongest perception of gender-based career obstacles were more likely to work part-time rather than full-time (OR, 0.59; 95% CI: 0.40-0.88). Although the experience of gender-based obstacles was not associated with working status among women physicians, the results demonstrated that a strong perception of gender-based obstacles was associated with part-time practice rather than full-time practice. Copyright © 2012 Elsevier Ltd. All rights reserved.

Anomalous behaviors during infiltration into heterogeneous porous media

NASA Astrophysics Data System (ADS)

Aarão Reis, F. D. A.; Bolster, D.; Voller, V. R.

2018-03-01

Flow and transport in heterogeneous porous media often exhibit anomalous behavior. A physical analog example is the uni-directional infiltration of a viscous liquid into a horizontal oriented Hele-Shaw cell containing through thickness flow obstacles; a system designed to mimic a gravel/sand medium with impervious inclusions. When there are no obstacles present or the obstacles form a multi-repeating pattern, the change of the length of infiltration F with time t tends to follow a Fickian like scaling, F ∼t1/2 . In the presence of obstacle fields laid out as Sierpinski carpet fractals, infiltration is anomalous, i.e., F ∼ tn, n ≠ 1/2. Here, we study infiltration into such Hele-Shaw cells. First we investigate infiltration into a square cell containing one fractal carpet and make the observation that it is possible to generate both sub (n < 1/2) and super (n > 1/2) diffusive behaviors within identical heterogeneity configurations. We show that this can be explained in terms of a scaling analysis developed from results of random-walk simulations in fractal obstacles; a result indicating that the nature of the domain boundary controls the exponent n of the resulting anomalous transport. Further, we investigate infiltration into a rectangular cell containing several repeats of a given Sierpinski carpet. At very early times, before the liquid encounters any obstacles, the infiltration is Fickian. When the liquid encounters the first (smallest scale) obstacle the infiltration sharply transitions to sub-diffusive. Subsequently, around the time where the liquid has sampled all of the heterogeneity length scales in the system, there is a rapid transition back to Fickian behavior. An explanation for this second transition is obtained by developing a simplified infiltration model based on the definition of a representative averaged hydraulic conductivity.

Self-efficacy beliefs of underrepresented minorities in science, technology, engineering, and math

NASA Astrophysics Data System (ADS)

Garibay, Guadalupe

The purpose of this study is to understand the self-perceptions, confidence, and self-efficacy of underrepresented minorities (URMs) as they undertake Science, Technology, Engineering and Math (STEM) courses during their K-12 years in urban-public schools. Through the lens of Bandura's self-efficacy theory, this study analyzed self-efficacious behaviors as they revealed themselves in K-12 classrooms. The participants were 11th- and 12th-grade students, their parents, their STEM teachers, and their mentor. The goal was to understand what has been inhibiting the growth of URM representation in STEM majors and in STEM fields. This qualitative study was designed to understand the participants' stories and uncover personal characteristics such as grit, perseverance, and determination in the face of obstacles. The instruments used in this study were interviews, observations, and self-efficacy surveys. The findings revealed that the participants' perceptions of the students' abilities to succeed in a STEM field were all tentatively positive. The participants focused on the many obstacles already overcome by the students and used it as precedent for future success. All the student-participants shared a similar set of adult types in their lives--adults who believed not only in their STEM abilities, but also in their abilities to face obstacles, who were willing to give their time and expertise when necessary, and who shared similar experiences in terms of the lack of educational resources or of economic struggles. It was these shared experiences that strengthened the beliefs that, if the adult participants could succeed in education or succeed in spite of poverty, the student participants could succeed, as well.

Mathematics for Critical Numeracy: A Case Study of a Social Justice Mathematics Course for Preservice Elementary Teachers

ERIC Educational Resources Information Center

Bateiha, Summer R.

2010-01-01

In spite of undeniable technological progress in our Western society, injustice continues to plague the twenty-first century. More than ever in human history, our civilization faces many obstacles that require our attention. Although some educators have contended that the primary goal of education should be to ensure social well-being, many still…

Video games: a route to large-scale STEM education?

PubMed

Mayo, Merrilea J

2009-01-02

Video games have enormous mass appeal, reaching audiences in the hundreds of thousands to millions. They also embed many pedagogical practices known to be effective in other environments. This article reviews the sparse but encouraging data on learning outcomes for video games in science, technology, engineering, and math (STEM) disciplines, then reviews the infrastructural obstacles to wider adoption of this new medium.

Issues Affecting the Future of the U.S. Space Science and Engineering Workforce: Interim Report

ERIC Educational Resources Information Center

National Academies Press, 2006

2006-01-01

In January 2006, the President announced a new civilian space policy focusing on exploration. As part of its preparations to implement that policy, NASA asked the NRC to explore long-range science and technology workforce needs to achieve the space exploration vision, identify obstacles to filling those needs, and put forward solutions to those…

Effectiveness and Obstacle of Using Facebook as a Tool to Facilitate Student-Centred Learning in Higher Education

ERIC Educational Resources Information Center

Cheng, Irene Nga Yee; Chan, Janet Kit Yan; Kong, Suria Suet Yee; Leung, Kenneth Mei Yee

2016-01-01

Blended learning which combines face-to-face and online experiences of students by integrating technology into the curriculum is increasingly prevalent in university education. In a context of long time arguments on the educational value of using social networking websites on teaching and learning, this study was conducted in two higher education…

Pesky Critters

DTIC Science & Technology

2005-11-01

is in relation to obstacles. Clearly, existing optical sensors are too large for this proposed system. Again, the approach utilizing biomimicry ...results in our latest conflicts. The Predator, a medium altitude system cruising at 70 knots and equipped with electro- optical and infrared cameras...that exist today, but the vehicles are also platforms for new concepts outside the status quo. 206 III. Technology Biomimicry is a new

Freedom and Empowerment: An Essay on the Next Step for Education and Technology

ERIC Educational Resources Information Center

Shimabukuro, James N.

2005-01-01

Online instruction has grown about as much as it possibly can within current educational structures. Educators are at the point where something has to give: Either schools will stay the same and leave online efforts at a standstill, or educators' concept of school will change and allow online instruction to grow. The primary obstacle to growth is…

Ethnophytotechnology: Harnessing the Power of Ethnobotany with Biotechnology.

PubMed

de la Parra, John; Quave, Cassandra L

2017-09-01

Ethnobotany (the scientific study of traditional plant knowledge) has aided the discovery of important medicines. However, as single-molecule drugs or synergistic mixtures, these remedies have faced obstacles in production and analysis. Now, advances in bioreactor technology, metabolic engineering, and analytical instrumentation are improving the production, manipulation, and scientific understanding of such remedies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Teaching and Learning with ICT Tools: Issues and Challenges from Teachers' Perceptions

ERIC Educational Resources Information Center

Ghavifekr, Simin; Kunjappan, Thanusha; Ramasamy, Logeswary; Anthony, Annreetha

2016-01-01

In this digital era, ICT use in the classroom is important for giving students opportunities to learn and apply the required 21st century skills. Hence studying the issues and challenges related to ICT use in teaching and learning can assist teachers in overcoming the obstacles and become successful technology users. Therefore, the main purpose of…

Residential energy conservation measures: a penny saved is a penny earned

DOE Office of Scientific and Technical Information (OSTI.GOV)

Finklea, E.A.; Treiber, M.P.

The authors are not suggesting that conservation alone will end our dependence on foreign oil. The focus is on basic household energy-conservation measures because they are technically simple, inexpensive, and available compared to more advanced energy-efficiency technologies (e.g., architectural designs and passive solar devices), or to alternative production technologies (e.g., photovoltaics and synthetic fuels). The social, institutional, and economic obstacles to implementing these basic measures are analyzed, and suggestions offered for overcoming these obstacles. During the Carter Administration, Congress enacted four laws to encourage the installation of household energy conservation measures. The laws provide: (1) tax credits for energy conservationmore » expenditures; (2) conservation investment subsidies for low income homeowners; and require: (3) natural gas and electric utilities to implement residential energy conservation programs for their customers; and (4) the federal government to provide loan subsidies for household energy-conservation investments through a conservation bank. The potential effectiveness of these federal programs are analyzed. President Reagan's advisers have indicated that the new administration will place greater emphasis on energy production and less emphasis on conservation. Consequently, the effectiveness of these programs may depend on the priority given them by the Reagan administration.« less

Conservation: Toward firmer ground

NASA Technical Reports Server (NTRS)

1975-01-01

The following aspects of energy conservation were discussed: conservation history and goals, conservation modes, conservation accounting-criteria, and a method to overcome obstacles. The conservation modes tested fall into one of the following categories: reduced energy consumption, increased efficiency of energy utilization, or substitution of one or more forms of energy for another which is in shorter supply or in some sense thought to be of more value. The conservation accounting criteria include net energy reduction, economic, and technical criteria. A method to overcome obstacles includes (approaches such as: direct personal impact (life style, income, security, aspiration), an element of crisis, large scale involvement of environmental, safety, and health issues, connections to big government, big business, big politics, involvement of known and speculative science and technology, appeal to moral and ethical standards, the transient nature of opportunities to correct the system.

Obstacle-avoiding navigation system

DOEpatents

Borenstein, Johann; Koren, Yoram; Levine, Simon P.

1991-01-01

A system for guiding an autonomous or semi-autonomous vehicle through a field of operation having obstacles thereon to be avoided employs a memory for containing data which defines an array of grid cells which correspond to respective subfields in the field of operation of the vehicle. Each grid cell in the memory contains a value which is indicative of the likelihood, or probability, that an obstacle is present in the respectively associated subfield. The values in the grid cells are incremented individually in response to each scan of the subfields, and precomputation and use of a look-up table avoids complex trigonometric functions. A further array of grid cells is fixed with respect to the vehicle form a conceptual active window which overlies the incremented grid cells. Thus, when the cells in the active window overly grid cell having values which are indicative of the presence of obstacles, the value therein is used as a multiplier of the precomputed vectorial values. The resulting plurality of vectorial values are summed vectorially in one embodiment of the invention to produce a virtual composite repulsive vector which is then summed vectorially with a target-directed vector for producing a resultant vector for guiding the vehicle. In an alternative embodiment, a plurality of vectors surrounding the vehicle are computed, each having a value corresponding to obstacle density. In such an embodiment, target location information is used to select between alternative directions of travel having low associated obstacle densities.

The use of electronic devices for communication with colleagues and other healthcare professionals - nursing professionals' perspectives.

PubMed

Koivunen, Marita; Niemi, Anne; Hupli, Maija

2015-03-01

The aim of the study is to describe nursing professionals' experiences of the use of electronic devices for communication with colleagues and other healthcare professionals. Information and communication technology applications in health care are rapidly expanding, thanks to the fast-growing penetration of the Internet and mobile technology. Communication between professionals in health care is essential for patient safety and quality of care. Implementing new methods for communication among healthcare professionals is important. A cross-sectional survey was used in the study. The data were collected in spring 2012 using an electronic questionnaire with structured and open-ended questions. The target group comprised the nursing professionals (N = 567, n = 123) in one healthcare district who worked in outpatient clinics in publically funded health care in Finland. Nursing professionals use different electronic devices for communication with each other. The most often used method was email, while the least used methods were question-answer programmes and synchronous communication channels on the Internet. Communication using electronic devices was used for practical nursing, improving personnel competences, organizing daily operations and administrative tasks. Electronic devices may speed up the management of patient data, improve staff cooperation and competence and make more effective use of working time. The obstacles were concern about information security, lack of technical skills, unworkable technology and decreasing social interaction. According to our findings, despite the obstacles related to use of information technology, the use of electronic devices to support communication among healthcare professionals appears to be useful. © 2014 John Wiley & Sons Ltd.

A future perspective on technological obsolescenceat NASA, Langley Research Center

NASA Technical Reports Server (NTRS)

Mcintyre, Robert M.

1990-01-01

The present research effort was the first phase of a study to forecast whether technological obsolescence will be a problem for the engineers, scientists, and technicians at NASA Langley Research Center (LaRC). There were four goals of the research: to review the literature on technological obsolescence; to determine through interviews of division chiefs and branch heads Langley's perspective on future technological obsolescence; to begin making contacts with outside industries to find out how they view the possibility of technological obsolescence; and to make preliminary recommendations for dealing with the problem. A complete description of the findings of this research can be reviewed in a technical report in preparation. The following are a small subset of the key findings of the study: NASA's centers and divisions vary in their missions and because of this, in their capability to control obsolescence; research-oriented organizations within NASA are believed by respondents to keep up to date more than the project-oriented organizations; asked what are the signs of a professional's technological obsolescence, respondents had a variety of responses; top performing scientists were viewed as continuous learners, keeping up to date by a variety of means; when asked what incentives were available to aerospace technologists for keeping up to data, respondents specified a number of ideas; respondents identified many obstacles to professionals' keeping up to date in the future; and most respondents expressed some concern for the future of the professionals at NASA vis a vis the issue of professional obsolescence.

The effects of multiple obstacles on the locomotor behavior and performance of a terrestrial lizard.

PubMed

Parker, Seth E; McBrayer, Lance D

2016-04-01

Negotiation of variable terrain is important for many small terrestrial vertebrates. Variation in the running surface resulting from obstacles (woody debris, vegetation, rocks) can alter escape paths and running performance. The ability to navigate obstacles likely influences survivorship through predator evasion success and other key ecological tasks (finding mates, acquiring food). Earlier work established that running posture and sprint performance are altered when organisms face an obstacle, and yet studies involving multiple obstacles are limited. Indeed, some habitats are cluttered with obstacles, whereas others are not. For many species, obstacle density may be important in predator escape and/or colonization potential by conspecifics. This study examines how multiple obstacles influence running behavior and locomotor posture in lizards. We predict that an increasing number of obstacles will increase the frequency of pausing and decrease sprint velocity. Furthermore, bipedal running over multiple obstacles is predicted to maintain greater mean sprint velocity compared with quadrupedal running, thereby revealing a potential advantage of bipedalism. Lizards were filmed running through a racetrack with zero, one or two obstacles. Bipedal running posture over one obstacle was significantly faster than quadrupedal posture. Bipedal running trials contained fewer total strides than quadrupedal ones. But on addition of a second obstacle, the number of bipedal strides decreased. Increasing obstacle number led to slower and more intermittent locomotion. Bipedalism provided clear advantages for one obstacle, but was not associated with further benefits for an additional obstacle. Hence, bipedalism helps mitigate obstacle negotiation, but not when numerous obstacles are encountered in succession. © 2016. Published by The Company of Biologists Ltd.

The path to COVIS: A review of acoustic imaging of hydrothermal flow regimes

NASA Astrophysics Data System (ADS)

Bemis, Karen G.; Silver, Deborah; Xu, Guangyu; Light, Russ; Jackson, Darrell; Jones, Christopher; Ozer, Sedat; Liu, Li

2015-11-01

Acoustic imaging of hydrothermal flow regimes started with the incidental recognition of a plume on a routine sonar scan for obstacles in the path of the human-occupied submersible ALVIN. Developments in sonar engineering, acoustic data processing and scientific visualization have been combined to develop technology which can effectively capture the behavior of focused and diffuse hydrothermal discharge. This paper traces the development of these acoustic imaging techniques for hydrothermal flow regimes from their conception through to the development of the Cabled Observatory Vent Imaging Sonar (COVIS). COVIS has monitored such flow eight times a day for several years. Successful acoustic techniques for estimating plume entrainment, bending, vertical rise, volume flux, and heat flux are presented as is the state-of-the-art in diffuse flow detection.

An Enigmatic Death in Farm Chopping Machine: Is This the Perfect Murder?

PubMed

Gioia, Sara; Lancia, Massimo; Bacci, Mauro; Suadoni, Fabio

2015-09-01

Forensic autopsy, like the other sectors in medicine, has benefited from the technological progress and the creation of multidisciplinary teams to unveil more and more finely planned criminal intents.Forensic pathologists, however, can sometimes deal with very enigmatic cases, meeting so with the limits of their own knowledge. Therefore, in these cases, they must not allow themselves to be pressured by inquiring agencies, remaining instead always faithful to empiric observations.With regard to that, we present a peculiar case of death by shredding inside a grinding machinery. The magistrature consequently opened a dossier for willful murder. Lots of figures were appointed to solve the case and among them is the forensic pathologist. However, a great number of obstacles were put in the investigators' inquiries.Was it a perfect murder?

High-Intensity Focused Ultrasound Therapy: an Overview for Radiologists

PubMed Central

Kim, Young-sun; Choi, Min Joo; Lim, Hyo Keun; Choi, Dongil

2008-01-01

High-intensity focused ultrasound therapy is a novel, emerging, therapeutic modality that uses ultrasound waves, propagated through tissue media, as carriers of energy. This completely non-invasive technology has great potential for tumor ablation as well as hemostasis, thrombolysis and targeted drug/gene delivery. However, the application of this technology still has many drawbacks. It is expected that current obstacles to implementation will be resolved in the near future. In this review, we provide an overview of high-intensity focused ultrasound therapy from the basic physics to recent clinical studies with an interventional radiologist's perspective for the purpose of improving the general understanding of this cutting-edge technology as well as speculating on future developments. PMID:18682666

Auto identification technology and its impact on patient safety in the Operating Room of the Future.

PubMed

Egan, Marie T; Sandberg, Warren S

2007-03-01

Automatic identification technologies, such as bar coding and radio frequency identification, are ubiquitous in everyday life but virtually nonexistent in the operating room. User expectations, based on everyday experience with automatic identification technologies, have generated much anticipation that these systems will improve readiness, workflow, and safety in the operating room, with minimal training requirements. We report, in narrative form, a multi-year experience with various automatic identification technologies in the Operating Room of the Future Project at Massachusetts General Hospital. In each case, the additional human labor required to make these ;labor-saving' technologies function in the medical environment has proved to be their undoing. We conclude that while automatic identification technologies show promise, significant barriers to realizing their potential still exist. Nevertheless, overcoming these obstacles is necessary if the vision of an operating room of the future in which all processes are monitored, controlled, and optimized is to be achieved.

West Europe report: Science and technology. FRG: Concept paper on microelectronics, communications technology

NASA Astrophysics Data System (ADS)

1984-07-01

Precisely because the Federal Republic of Germany is a nation with a strong export orientation the capability to develop and apply, with an eye to the market, modern information and communication technologies and microelectronics which provides the basis for them has a very important bearing on the nations competitive position. To attain a leadership position in information technology, the men and women of the FRG must take up the challenge of this technology in terms of training and continuing education as well as in the media and in public life. Industry must agressively seek out markets and engage in international competition and the state must remove existing obstacles and create the kind of conditions that will make its assistance programs most effective. Programs which reflect the government's resolve to meet the challenge of information technology and to help improve the FRG's competitive position in this field are outlined.

Atmospheric dispersion of a heavier-than-air gas near a two-dimensional obstacle

NASA Astrophysics Data System (ADS)

Sutton, S. B.; Brandt, H.; White, B. R.

1986-04-01

Flow over a two-dimensional obstacle and dispersion of a heavier-than-air gas near the obstacle were studied. Two species, one representing air and the other representing the heavier-than-air gas were treated. Equations for mass and momentum were cast in mass-averaged form, with turbulent Reynolds stresses and mass fluxes modeled using eddy-viscosity and diffusivity hypotheses. A two-equation k-ɛ turbulence model was used to determine the effective turbulent viscosity. Streamline curvature and buoyancy corrections were added to the basic turbulence formulation. The model equations were solved using finite difference techniques. An alternating-direction-implicit (ADI) technique was used to solve the parabolic transport equations and a direct matrix solver was used to solve the elliptic pressure equation. Mesh sensitivities were investigated to determine the optimum mesh requirements for the final calculations. It was concluded that at least 10 grid spaces were required across the obstacle width and 15 across the obstacle height to obtain valid solutions. A non-uniform mesh was used to concentrate the grid points at the top of the obstacle. Experimental measurements were made with air flow over a 7.6 by 7.6 cm obstacle in a boundary-layer wind tunnel. Smoke visualization revealed a low-frequency oscillation of the bubble downstream of the obstacle. Hot-wire anemometer data are presented for the mean velocity and turbulent kinetic energy at the mid-plane of the obstacle and the mid-plane of the downstream recirculation bubble. A single hot-wire probe was found to be suitable for determining mean streamwise velocities with an accuracy of 11 %. The downstream recirculation bubble was unsteady and had a length range from 3 to 8 obstacle lengths. The experimental results for flow over the obstacle were compared with numerical calculations to validate the numerical solution procedure. A sensitivity study on the effect of curvature correction and variation of turbulence model constants on the numerical solution was conducted. Calculations that included the curvature correction model gave a downstream recirculation bubble length of 5.9 obstacle lengths while excluding the correction reduced this length to 4.4. In the second part of the study, numerical calculations were performed for the dispersion of a heavier-than-air gas in the vicinity of the two-dimensional obstacle. Characteristics of an adiabatic boundary layer were used in these calculations. The densities of the contaminant gases were 0, 25 and 50% greater than the air density. Calculations were performed with the contaminant injection source upstream and downstream of the obstacle. Use of the pressure gradient model reduced the size of the dense gas cloud by as much as 12%. The curvature correction model also affected the cloud expanse by reducing the effective turbulent viscosity in the downstream recirculation bubble. The location of the injection source had the largest impact on the cloud size. The area of the cloud within the 5 % contour was three times larger for downstream injection than for upstream injection.

Virtual reality-based navigation task to reveal obstacle avoidance performance in individuals with visuospatial neglect.

PubMed

Aravind, Gayatri; Darekar, Anuja; Fung, Joyce; Lamontagne, Anouk

2015-03-01

Persons with post-stroke visuospatial neglect (VSN) often collide with moving obstacles while walking. It is not well understood whether the collisions occur as a result of attentional-perceptual deficits caused by VSN or due to post-stroke locomotor deficits. We assessed individuals with VSN on a seated, joystick-driven obstacle avoidance task, thus eliminating the influence of locomotion. Twelve participants with VSN were tested on obstacle detection and obstacle avoidance tasks in a virtual environment that included three obstacles approaching head-on or 30 (°) contralesionally/ipsilesionally. Our results indicate that in the detection task, the contralesional and head-on obstacles were detected at closer proximities compared to the ipsilesional obstacle. For the avoidance task collisions were observed only for the contralesional and head-on obstacle approaches. For the contralesional obstacle approach, participants initiated their avoidance strategies at smaller distances from the obstacle and maintained smaller minimum distances from the obstacles. The distance at detection showed a negative association with the distance at the onset of avoidance strategy for all three obstacle approaches. We conclusion the observation of collisions with contralesional and head-on obstacles, in the absence of locomotor burden, provides evidence that attentional-perceptual deficits due to VSN, independent of post-stroke locomotor deficits, alter obstacle avoidance abilities.

African-American Leaders in the Field of Science: A Template for Overcoming Obstacles

NASA Astrophysics Data System (ADS)

Schmidt, Waweise J.

The purpose of this phenomenological multi-case study and three-person interview, was to discover what select prominent African-American scientists perceived were obstacles to overcome to be successful leaders in their professional lives, and the opportunities that aided in their professional growth. Through the addition of the three-person interview, the researcher discovered commonalities between the perceived obstacles and opportunities of current science, technology, engineering and mathematics (STEM) professionals and the perceptions of selected historically prominent scientists. This study examined documents of the period and relics of prominent African-Americans who were in STEM fields and lived from 1860 to 1968. A description of the setting that influenced how the scientists perceived the phenomenon was written with the approach being anchored in the social constructivist tradition. Commonalities emerged through coding experiences of the individuals, which yielded patterns to help explain the phenomenon. By investigating their perceptions, insight was gained into understanding the attributes, tools and skills, and tailored experiences that encouraged Thomas Burton, Kelly Miller, George Carver, Daniel Williams, Matthew Henson, Ernest Just, Charles Drew, Percy Julian, William Cobb, and Benjamin Peery to achieve success in STEM fields between 1860 and 1968. The significance of the study is multifaceted: understanding the obstacles that African-American scientists had to overcome in their professional lives can result in the development of science educators who are better informed regarding the appropriate types of assistance that can be provided to aid their students in overcoming obstacles. This can hopefully increase their opportunities to succeed within the science field. This study can result in the development of science educators who are more sensitive in addressing the needs of the developing minority student, and can encourage, educate, and enlist more individuals to enter into the dialogue regarding the disparity of minority representation in STEM fields.

Vortex propagation around a wall-mounted obstacle in pulsatile flow

NASA Astrophysics Data System (ADS)

Carr, Ian A.; Plesniak, Michael W.

2015-11-01

Wall-mounted obstacles are prevalent in nature and engineering applications. Physiological flows observed in human vocal fold pathologies, such as polyps, can be modeled by flow over a wall-mounted protuberance. Despite their prevalence, studies of wall-mounted obstacles have been restricted to steady (constant velocity) freestream flow. In biological and geophysical applications, pulsatile flow is much more common, yet effects of pulsatility on the wake of a wall-mounted obstacle remain to be extensively studied. This study aims to characterize the complex physics produced in this unsteady, separated flow. Experiments were performed in a low-speed wind tunnel with a set of rotating vanes, which produce the pulsatile inflow waveform. Instantaneous and phase-averaged particle image velocimetry (PIV) results acquired around a hemispherical obstacle are presented and compared. A mechanism based on self-induced vortex propagation, analogous to that in vortex rings, is proposed to explain the observed dynamics of coherent structures. Predictions of the propagation velocity based on analytical expressions for vortex rings in a viscous fluid are compared to the experimentally measured propagation velocity. Effects of the unsteady boundary layer on the observed physics are explored. This material is based in part upon work supported by the National Science Foundation under Grant Number CBET-1236351, and GW Center for Biomimetics and Bioinspired Engineering (COBRE).

Evaluation of Mental Workload among ICU Ward's Nurses

PubMed Central

Mohammadi, Mohsen; Mazloumi, Adel; Kazemi, Zeinab; Zeraati, Hojat

2015-01-01

Background: High level of workload has been identified among stressors of nurses in intensive care units (ICUs). The present study investigated nursing workload and identified its influencing perfor­mance obstacles in ICUs. Methods: This cross-sectional study was conducted, in 2013, on 81 nurses working in ICUs in Imam Khomeini Hospital in Tehran, Iran. NASA-TLX was applied for assessment of workload. Moreover, ICUs Performance Obstacles Questionnaire was used to identify performance obstacles associated with ICU nursing. Results: Physical demand (mean=84.17) was perceived as the most important dimensions of workload by nurses. The most critical performance obstacles affecting workload included: difficulty in finding a place to sit down, hectic workplace, disorganized workplace, poor-conditioned equipment, waiting for using a piece of equipment, spending much time seeking for supplies in the central stock, poor quality of medical materials, delay in getting medications, unpredicted problems, disorganized central stock, outpatient surgery, spending much time dealing with family needs, late, inadequate, and useless help from nurse assistants, and ineffective morning rounds (P-value<0.05). Conclusion: Various performance obstacles are correlated with nurses' workload, affirms the significance of nursing work system characteristics. Interventions are recommended based on the results of this study in the work settings of nurses in ICUs. PMID:26933647

Generic Dynamic Environment Perception Using Smart Mobile Devices.

PubMed

Danescu, Radu; Itu, Razvan; Petrovai, Andra

2016-10-17

The driving environment is complex and dynamic, and the attention of the driver is continuously challenged, therefore computer based assistance achieved by processing image and sensor data may increase traffic safety. While active sensors and stereovision have the advantage of obtaining 3D data directly, monocular vision is easy to set up, and can benefit from the increasing computational power of smart mobile devices, and from the fact that almost all of them come with an embedded camera. Several driving assistance application are available for mobile devices, but they are mostly targeted for simple scenarios and a limited range of obstacle shapes and poses. This paper presents a technique for generic, shape independent real-time obstacle detection for mobile devices, based on a dynamic, free form 3D representation of the environment: the particle based occupancy grid. Images acquired in real time from the smart mobile device's camera are processed by removing the perspective effect and segmenting the resulted bird-eye view image to identify candidate obstacle areas, which are then used to update the occupancy grid. The occupancy grid tracked cells are grouped into obstacles depicted as cuboids having position, size, orientation and speed. The easy to set up system is able to reliably detect most obstacles in urban traffic, and its measurement accuracy is comparable to a stereovision system.

Flow through a very porous obstacle in a shallow channel

PubMed Central

Draper, S.; Nishino, T.; Borthwick, A. G. L.

2017-01-01

A theoretical model, informed by numerical simulations based on the shallow water equations, is developed to predict the flow passing through and around a uniform porous obstacle in a shallow channel, where background friction is important. This problem is relevant to a number of practical situations, including flow through aquatic vegetation, the performance of arrays of turbines in tidal channels and hydrodynamic forces on offshore structures. To demonstrate this relevance, the theoretical model is used to (i) reinterpret core flow velocities in existing laboratory-based data for an array of emergent cylinders in shallow water emulating aquatic vegetation and (ii) reassess the optimum arrangement of tidal turbines to generate power in a tidal channel. Comparison with laboratory-based data indicates a maximum obstacle resistance (or minimum porosity) for which the present theoretical model is valid. When the obstacle resistance is above this threshold the shallow water equations do not provide an adequate representation of the flow, and the theoretical model over-predicts the core flow passing through the obstacle. The second application of the model confirms that natural bed resistance increases the power extraction potential for a partial tidal fence in a shallow channel and alters the optimum arrangement of turbines within the fence. PMID:28484321

Blending addiction research and practice: strategies for technology transfer.

PubMed

Condon, Timothy P; Miner, Lucinda L; Balmer, Curtis W; Pintello, Denise

2008-09-01

Consistent with traditional conceptions of technology transfer, efforts to translate substance abuse and addiction research into treatment practice have typically relied on the passive dissemination of research findings. The large gap between addiction research and practice, however, indicates that there are many barriers to successful technology transfer and that dissemination alone is not sufficient to produce lasting changes in addiction treatment. To accelerate the translation of research into practice, the National Institute on Drug Abuse launched the Blending Initiative in 2001. In part a collaboration with the Substance Abuse and Mental Health Services Administration/Center for Substance Abuse Treatment's Addiction Technology Transfer Center program, this initiative aims to improve the development, effectiveness, and usability of evidence-based practices and reduce the obstacles to their timely adoption and implementation.

Prefrontal cortex activation during obstacle negotiation: What's the effect size and timing?

PubMed

Maidan, Inbal; Shustak, Shiran; Sharon, Topaz; Bernad-Elazari, Hagar; Geffen, Nimrod; Giladi, Nir; Hausdorff, Jeffrey M; Mirelman, Anat

2018-04-01

Obstacle negotiation is a daily activity that requires the integration of sensorimotor and cognitive information. Recent studies provide evidence for the important role of prefrontal cortex during obstacle negotiation. We aimed to explore the effects of obstacle height and available response time on prefrontal activation. Twenty healthy young adults (age: 30.1 ± 1.0 years; 50% women) walked in an obstacle course while negotiating anticipated and unanticipated obstacles at heights of 50 mm and 100 mm. Prefrontal activation was measured using a functional near-infrared spectroscopy system. Kinect cameras measured the obstacle negotiation strategy. Prefrontal activation was defined based on mean level of HbO 2 before, during and after obstacle negotiation and the HbO 2 slope from gait initiation and throughout the task. Changes between types of obstacles were assessed using linear-mix models and partial correlation analyses evaluated the relationship between prefrontal activation and the distance between the feet as the subjects traversed the obstacles. Different obstacle heights showed similar changes in prefrontal activation measures (p > 0.210). However, during unanticipated obstacles, the slope of the HbO 2 response was steeper (p = 0.048), as compared to anticipated obstacles. These changes in prefrontal activation during negotiation of unanticipated obstacles were correlated with greater distance of the leading foot after the obstacles (r = 0.831, p = 0.041). These findings are the first to show that the pattern of prefrontal activation depends on the nature of the obstacle. More specifically, during unanticipated obstacles the recruitment of the prefrontal cortex is faster and greater than during negotiating anticipated obstacles. These results provide evidence of the important role of the prefrontal cortex and the ability of healthy young adults to tailor the activation pattern to different types of obstacles. Copyright © 2018 Elsevier Inc. All rights reserved.

The Magsat magnetometer boom

NASA Technical Reports Server (NTRS)

Smola, J. F.; Radford, W. E.; Reitz, M. H.

1980-01-01

A lightweight extendable structure that can precisely position magnetically sensitive instruments safe distances from magnetic sources in a spacecraft is described as well as the major areas of concern that played dominant roles in its development. Weight, packaging volume, thermal distortion, mechanical misalignments, dimensional instability, launch environments, and low temperature functioning were areas that presented some formidable obstacles. The ways in which these obstacles were dealt with are examined for those involving the development of similar aerospace mechanisms with equally restrictive requirements.

Transient bow shock around a cylinder in a supersonic dusty plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meyer, John K.; Merlino, Robert L.

2013-07-15

Visual observations of the formation of a bow shock in the transient supersonic flow of a dusty plasma incident on a biased cylinder are presented. The bow shock formed when the advancing front of a streaming dust cloud was reflected by the obstacle. After its formation, the density jump of the bow shock increased as it moved upstream of the obstacle. A physical picture for the formation of the electrohydrodynamic bow shock is discussed.

Computational extended magneto-hydrodynamical study of shock structure generated by flows past an obstacle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Xuan, E-mail: xzhao@cylance.com; Seyler, C. E., E-mail: ces7@cornell.edu

2015-07-15

The magnetized shock problem is studied in the context where supersonic plasma flows past a solid obstacle. This problem exhibits interesting and important phenomena such as a bow shock, magnetotail formation, reconnection, and plasmoid formation. This study is carried out using a discontinuous Galerkin method to solve an extended magneto-hydrodynamic model (XMHD). The main goals of this paper are to present a reasonably complete picture of the properties of this interaction using the MHD model and then to compare the results to the XMHD model. The inflow parameters, such as the magnetosonic Mach number M{sub f} and the ratio ofmore » thermal pressure to magnetic pressure β, can significantly affect the physical structures of the flow-obstacle interaction. The Hall effect can also significantly influence the results in the regime in which the ion inertial length is numerically resolved. Most of the results presented are for the two-dimensional case; however, two three-dimensional simulations are presented to make a connection to the important case in which the solar wind interacts with a solid body and to explore the possibility of performing scaled laboratory experiments.« less

Non-intrusive speed sensor. [space shuttle main engine turbopumps

NASA Technical Reports Server (NTRS)

Maram, J.; Wyett, L.

1984-01-01

A computerized literature search was performed to identify candidate technologies for remote, non-intrusive speed sensing applications in Space Shuttle Main Engine (SSME) turbopumps. The three most promising technologies were subjected to experimental evaluation to quantify their performance characteristics under the harsh environmental requirements within the turbopumps. Although the infrared and microwave approaches demonstrated excellent cavitation immunity in laboratory tests, the variable-source magnetic speed sensor emerged as the most viable approach. Preliminary design of this speed sensor encountered no technical obstacles and resulted in viable and feasible speed nut, sensor housing, and sensor coil designs.

Project M: An Assessment of Mission Assumptions

NASA Technical Reports Server (NTRS)

Edwards, Alycia

2010-01-01

Project M is a mission Johnson Space Center is working on to send an autonomous humanoid robot to the moon (also known as Robonaut 2) in l000 days. The robot will be in a lander, fueled by liquid oxygen and liquid methane, and land on the moon, avoiding any hazardous obstacles. It will perform tasks like maintenance, construction, and simple student experiments. This mission is also being used as inspiration for new advancements in technology. I am considering three of the design assumptions that contribute to determining the mission feasibility: maturity of robotic technology, launch vehicle determination, and the LOX/Methane fueled spacecraft

Age-associated changes in obstacle negotiation strategies: Does size and timing matter?

PubMed

Maidan, I; Eyal, S; Kurz, I; Geffen, N; Gazit, E; Ravid, L; Giladi, N; Mirelman, A; Hausdorff, J M

2018-01-01

Tripping over an obstacle is one of the most common causes of falls among older adults. However, the effects of aging, obstacle height and anticipation time on negotiation strategies have not been systematically evaluated. Twenty older adults (ages: 77.7±3.4years; 50% women) and twenty young adults (age: 29.3±3.8years; 50% women) walked through an obstacle course while negotiating anticipated and unanticipated obstacles at heights of 25mm and 75mm. Kinect cameras captured the: (1) distance of the subject's trailing foot before the obstacles, (2) distance of the leading foot after the obstacles, (3) clearance of the leading foot above the obstacles, and (4) clearance of the trailing foot above the obstacles. Linear-mix models assessed changes between groups and conditions. Older adults placed their leading foot closer to the obstacle after landing, compared to young adults (p<0.001). This pattern was enhanced in high obstacles (group*height interaction, p=0.033). Older adults had lower clearance over the obstacles, compared to young adults (p=0.007). This was more pronounced during unanticipated obstacles (group*ART interaction, p=0.003). The distance of the leading foot and clearance of the trailing foot after the obstacles were correlated with motor, cognitive, and functional abilities. These findings suggest that there are age-related changes in obstacle crossing strategies that are dependent on the specific characteristics of the obstacle. The results have important implications for clinical practice, suggesting that functional exercise should include obstacle negotiation training with variable practice of height and available response times. Further studies are needed to better understand the effects of motor and cognitive abilities. Copyright © 2017 Elsevier B.V. All rights reserved.

Robust obstacle detection for unmanned surface vehicles

NASA Astrophysics Data System (ADS)

Qin, Yueming; Zhang, Xiuzhi

2018-03-01

Obstacle detection is of essential importance for Unmanned Surface Vehicles (USV). Although some obstacles (e.g., ships, islands) can be detected by Radar, there are many other obstacles (e.g., floating pieces of woods, swimmers) which are difficult to be detected via Radar because these obstacles have low radar cross section. Therefore, detecting obstacle from images taken onboard is an effective supplement. In this paper, a robust vision-based obstacle detection method for USVs is developed. The proposed method employs the monocular image sequence captured by the camera on the USVs and detects obstacles on the sea surface from the image sequence. The experiment results show that the proposed scheme is efficient to fulfill the obstacle detection task.

Putting the Information Infrastructure to Work. Report of the Information Infrastructure Task Force Committee on Applications and Technology. NIST Special Publication 857.

ERIC Educational Resources Information Center

National Inst. of Standards and Technology, Gaithersburg, MD.

An interconnection of computer networks, telecommunications services, and applications, the National Information Infrastructure (NII) can open up new vistas and profoundly change much of American life. This report explores some of the opportunities and obstacles to the use of the NII by people and organizations. The goal is to express how…

United States Navy Health Care Providers' Attitudes and Satisfaction toward the Usability of the Navy's Primary Learning Portal and Learning Management System

ERIC Educational Resources Information Center

Catanese, Anthony Peter

2013-01-01

The purpose of this study was to investigate if the architectural design factors affected usability of Navy Knowledge Online (NKO) technology along with the user dissatisfaction associated through restricted achievements of online education and training. In this study, attitudes, satisfaction, obstacles, and providers' demographics were also…

TCP Pacing Developed

NASA Technical Reports Server (NTRS)

Ivancic, William D.

2002-01-01

Transmission control protocol (TCP) was conceived and designed to run over a variety of communication links, including wireless and high-bandwidth links. However, with recent technological advances in satellite and fiber-optic networks, researchers are reevaluating the flexibility of TCP. The TCP pacing and packet pair probing implementation may help overcome two of the major obstacles identified for efficient bandwidth utilization over communication links with large delay-bandwidth products.

A Hybrid Model for IT Investment Analysis: Application to RFID Adoption in the Retail Sector

ERIC Educational Resources Information Center

Kasiri, Narges A.

2010-01-01

Scope and Method of Study. One of the major obstacles in Information Technology (IT) adoption is its return on investment analysis. IT benefits in organizations are hard to measure and are usually realized over time. System dynamics approach has been used in IT literature to identify the impact of IT on business processes. Given benefits of any IT…

The scaling of performance and losses in miniature internal combustion engines

NASA Astrophysics Data System (ADS)

Menon, Shyam Kumar

Miniature glow ignition internal combustion (IC) piston engines are an off--the--shelf technology that could dramatically increase the endurance of miniature electric power supplies and the range and endurance of small unmanned air vehicles provided their overall thermodynamic efficiencies can be increased to 15% or better. This thesis presents the first comprehensive analysis of small (<500 g) piston engine performance. A unique dynamometer system is developed that is capable of making reliable measurements of engine performance and losses in these small engines. Methodologies are also developed for measuring volumetric, heat transfer, exhaust, mechanical, and combustion losses. These instruments and techniques are used to investigate the performance of seven single-cylinder, two-stroke, glow fueled engines ranging in size from 15 to 450 g (0.16 to 7.5 cm3 displacement). Scaling rules for power output, overall efficiency, and normalized power are developed from the data. These will be useful to developers of micro-air vehicles and miniature power systems. The data show that the minimum length scale of a thermodynamically viable piston engine based on present technology is approximately 3 mm. Incomplete combustion is the most important challenge as it accounts for 60-70% of total energy losses. Combustion losses are followed in order of importance by heat transfer, sensible enthalpy, and friction. A net heat release analysis based on in-cylinder pressure measurements suggest that a two--stage combustion process occurs at low engine speeds and equivalence ratios close to 1. Different theories based on burning mode and reaction kinetics are proposed to explain the observed results. High speed imaging of the combustion chamber suggests that a turbulent premixed flame with its origin in the vicinity of the glow plug is the primary driver of combustion. Placing miniature IC engines on a turbulent combustion regime diagram shows that they operate in the 'flamelet in eddy' regime whereas conventional--scale engines operate mostly in the 'wrinkled laminar flame sheet' regime. Taken together, the results show that the combustion process is the key obstacle to realizing the potential of small IC engines. Overcoming this obstacle will require new diagnostic techniques, measurements, combustion models, and high temperature materials.

The Sensitivity Analysis for the Flow Past Obstacles Problem with Respect to the Reynolds Number

PubMed Central

Ito, Kazufumi; Li, Zhilin; Qiao, Zhonghua

2013-01-01

In this paper, numerical sensitivity analysis with respect to the Reynolds number for the flow past obstacle problem is presented. To carry out such analysis, at each time step, we need to solve the incompressible Navier-Stokes equations on irregular domains twice, one for the primary variables; the other is for the sensitivity variables with homogeneous boundary conditions. The Navier-Stokes solver is the augmented immersed interface method for Navier-Stokes equations on irregular domains. One of the most important contribution of this paper is that our analysis can predict the critical Reynolds number at which the vortex shading begins to develop in the wake of the obstacle. Some interesting experiments are shown to illustrate how the critical Reynolds number varies with different geometric settings. PMID:24910780

The Sensitivity Analysis for the Flow Past Obstacles Problem with Respect to the Reynolds Number.

PubMed

Ito, Kazufumi; Li, Zhilin; Qiao, Zhonghua

2012-02-01

In this paper, numerical sensitivity analysis with respect to the Reynolds number for the flow past obstacle problem is presented. To carry out such analysis, at each time step, we need to solve the incompressible Navier-Stokes equations on irregular domains twice, one for the primary variables; the other is for the sensitivity variables with homogeneous boundary conditions. The Navier-Stokes solver is the augmented immersed interface method for Navier-Stokes equations on irregular domains. One of the most important contribution of this paper is that our analysis can predict the critical Reynolds number at which the vortex shading begins to develop in the wake of the obstacle. Some interesting experiments are shown to illustrate how the critical Reynolds number varies with different geometric settings.

An integrated collision prediction and avoidance scheme for mobile robots in non-stationary environments

NASA Technical Reports Server (NTRS)

Kyriakopoulos, K. J.; Saridis, G. N.

1993-01-01

A formulation that makes possible the integration of collision prediction and avoidance stages for mobile robots moving in general terrains containing moving obstacles is presented. A dynamic model of the mobile robot and the dynamic constraints are derived. Collision avoidance is guaranteed if the distance between the robot and a moving obstacle is nonzero. A nominal trajectory is assumed to be known from off-line planning. The main idea is to change the velocity along the nominal trajectory so that collisions are avoided. A feedback control is developed and local asymptotic stability is proved if the velocity of the moving obstacle is bounded. Furthermore, a solution to the problem of inverse dynamics for the mobile robot is given. Simulation results verify the value of the proposed strategy.

Advanced obstacle avoidance for a laser based wheelchair using optimised Bayesian neural networks.

PubMed

Trieu, Hoang T; Nguyen, Hung T; Willey, Keith

2008-01-01

In this paper we present an advanced method of obstacle avoidance for a laser based intelligent wheelchair using optimized Bayesian neural networks. Three neural networks are designed for three separate sub-tasks: passing through a door way, corridor and wall following and general obstacle avoidance. The accurate usable accessible space is determined by including the actual wheelchair dimensions in a real-time map used as inputs to each networks. Data acquisitions are performed separately to collect the patterns required for specified sub-tasks. Bayesian frame work is used to determine the optimal neural network structure in each case. Then these networks are trained under the supervision of Bayesian rule. Experiment results showed that compare to the VFH algorithm our neural networks navigated a smoother path following a near optimum trajectory.

Why Implementing History and Philosophy in School Science Education is a Challenge: An Analysis of Obstacles

NASA Astrophysics Data System (ADS)

Höttecke, Dietmar; Silva, Cibelle Celestino

2011-03-01

Teaching and learning with history and philosophy of science (HPS) has been, and continues to be, supported by science educators. While science education standards documents in many countries also stress the importance of teaching and learning with HPS, the approach still suffers from ineffective implementation in school science teaching. In order to better understand this problem, an analysis of the obstacles of implementing HPS into classrooms was undertaken. The obstacles taken into account were structured in four groups: 1. culture of teaching physics, 2. teachers' skills, epistemological and didactical attitudes and beliefs, 3. institutional framework of science teaching, and 4. textbooks as fundamental didactical support. Implications for more effective implementation of HPS are presented, taking the social nature of educational systems into account.

Fast obstacle detection based on multi-sensor information fusion

NASA Astrophysics Data System (ADS)

Lu, Linli; Ying, Jie

2014-11-01

Obstacle detection is one of the key problems in areas such as driving assistance and mobile robot navigation, which cannot meet the actual demand by using a single sensor. A method is proposed to realize the real-time access to the information of the obstacle in front of the robot and calculating the real size of the obstacle area according to the mechanism of the triangle similarity in process of imaging by fusing datum from a camera and an ultrasonic sensor, which supports the local path planning decision. In the part of image analyzing, the obstacle detection region is limited according to complementary principle. We chose ultrasonic detection range as the region for obstacle detection when the obstacle is relatively near the robot, and the travelling road area in front of the robot is the region for a relatively-long-distance detection. The obstacle detection algorithm is adapted from a powerful background subtraction algorithm ViBe: Visual Background Extractor. We extracted an obstacle free region in front of the robot in the initial frame, this region provided a reference sample set of gray scale value for obstacle detection. Experiments of detecting different obstacles at different distances respectively, give the accuracy of the obstacle detection and the error percentage between the calculated size and the actual size of the detected obstacle. Experimental results show that the detection scheme can effectively detect obstacles in front of the robot and provide size of the obstacle with relatively high dimensional accuracy.

Introduction of frictional and turning function for pedestrian outflow with an obstacle.

PubMed

Yanagisawa, Daichi; Kimura, Ayako; Tomoeda, Akiyasu; Nishi, Ryosuke; Suma, Yushi; Ohtsuka, Kazumichi; Nishinari, Katsuhiro

2009-09-01

In this paper, two important factors which affect the pedestrian outflow at a bottleneck significantly are studied in detail to analyze the effect of an obstacle setup in front of an exit. One is a conflict at an exit when pedestrians evacuate from a room. We use floor field model for simulating such behavior, which is a well-studied pedestrian model using cellular automata. The conflicts have been taken into account by the friction parameter. However, the friction parameter so far is a constant and does not depend on the number of the pedestrians conflicting at the same time. Thus, we have improved the friction parameter by the frictional function, which is a function of the number of the pedestrians involved in the conflict. Second, we have presented the cost of turning of pedestrians at the exit. Since pedestrians have inertia, their walking speeds decrease when they turn and the pedestrian outflow decreases. The validity of the extended model, which includes the frictional function and the turning function, is supported by the comparison of a mean-field theory and real experiments. We have observed that the pedestrian flow increases when we put an obstacle in front of an exit in our real experiments. The analytical results clearly explains the mechanism of the effect of the obstacle, i.e., the obstacle blocks pedestrians moving to the exit and decreases the average number of pedestrians involved in the conflict. We have also found that an obstacle works more effectively when we shift it from the center since pedestrians go through the exit with less turning.

Performance and wake conditions of a rotor located in the wake of an obstacle

NASA Astrophysics Data System (ADS)

Naumov, I. V.; Kabardin, I. K.; Mikkelsen, R. F.; Okulov, V. L.; Sørensen, J. N.

2016-09-01

Obstacles like forests, ridges and hills can strongly affect the velocity profile in front of a wind turbine rotor. The present work aims at quantifying the influence of nearby located obstacles on the performance and wake characteristics of a downstream located wind turbine. Here the influence of an obstacle in the form of a cylindrical disk was investigated experimentally in a water flume. A model of a three-bladed rotor, designed using Glauert's optimum theory at a tip speed ratio λ = 5, was placed in the wake of a disk with a diameter close to the one of the rotor. The distance from the disk to the rotor was changed from 4 to 8 rotor diameters, with the vertical distance from the rotor axis varied 0.5 and 1 rotor diameters. The associated turbulent intensity of the incoming flow to the rotor changed 3 to '6% due to the influence of the disk wake. In the experiment, thrust characteristics and associated pulsations as a function of the incoming flow structures were measured by strain gauges. The flow condition in front of the rotor was measured with high temporal accuracy using LDA and power coefficients were determine as function of tip speed ratio for different obstacle positions. Furthermore, PIV measurements were carried out to study the development of the mean velocity deficit profiles of the wake behind the wind turbine model under the influence of the wake generated by the obstacle. By use of regression techniques to fit the velocity profiles it was possible to determine velocity deficits and estimate length scales of the wake attenuation.

Universities innovation and technology commercialization challenges and solutions from the perspectives of Malaysian research universities

NASA Astrophysics Data System (ADS)

Rasli, Amran; Kowang, Tan Owee

2017-11-01

The roles of universities in the context of a nation's shift towards sustainable competitive advantage have changed drastically recently. Universities are now expected to contribute to the creation of new knowledge-based industries, i.e. to support knowledge-based economic growth through the creation of industrially-relevant knowledge/innovation and their commercialization, and to attract global MNCs in new emerging industries; and foster entrepreneurial mindset to support the future knowledge economy where stable job opportunities are no longer guaranteed. As such, there is a need to inculcate the spirit of enterprise as compared to the past where high economic growth has provided graduates with good career prospects as salaried employees, particularly in MNC subsidiaries and the government. The shift requires a bigger role in supporting innovation and commercialization, i.e. to venture beyond its traditional function of teaching, research and publication by incorporating a technology commercialization role which will inevitably help the institution to improve its global ranking. However, there are many national and operational obstacles that impede the progression of research and development to commercialization and entrepreneurship. The main challenges include: (I) lack of connectivity between the industry and academia; (2) myopic perception of the market; (3) inability to evaluate viability from ideas to innovations and beyond; (4) lack of support for investment in new technologies, and (5) lack of positive culture among academic researchers. To overcome the aforementioned obstacles, priority in developing a complete commercialization ecosystem has become a national agenda for most emerging economies.

Legal and Regulatroy Obstacles to Nuclear Fission Technology in Space

NASA Astrophysics Data System (ADS)

Force, Melissa K.

2013-09-01

In forecasting the prospective use of small nuclear reactors for spacecraft and space-based power stations, the U.S. Air Force describes space as "the ultimate high ground," providing access to every part of the globe. But is it? A report titled "Energy Horizons: United States Air Force Energy Science &Technology Vision 2011-2026," focuses on core Air Force missions in space energy generation, operations and propulsion and recognizes that investments into small modular nuclear fission reactors can be leveraged for space-based systems. However, the report mentions, as an aside, that "potential catastrophic outcomes" are an element to be weighed and provides no insight into the monumental political and legal will required to overcome the mere stigma of nuclear energy, even when referring only to the most benign nuclear power generation systems - RTGs. On the heels of that report, a joint Department of Energy and NASA team published positive results from the demonstration of a uranium- powered fission reactor. The experiment was perhaps most notable for exemplifying just how effective the powerful anti-nuclear lobby has been in the United States: It was the first such demonstration of its kind in nearly fifty years. Space visionaries must anticipate a difficult war, consisting of multiple battles that must be waged in order to obtain a license to fly any but the feeblest of nuclear power sources in space. This paper aims to guide the reader through the obstacles to be overcome before nuclear fission technology can be put to use in space.

Considerations on Visible Light Communication security by applying the Risk Matrix methodology for risk assessment

PubMed Central

Rabadan, Jose; Perez-Jimenez, Rafael

2017-01-01

Visible Light Communications (VLC) is a cutting edge technology for data communication that is being considered to be implemented in a wide range of applications such as Inter-vehicle communication or Local Area Network (LAN) communication. As a novel technology, some aspects of the implementation of VLC have not been deeply considered or tested. Among these aspects, security and its implementation may become an obstacle for VLCs broad usage. In this article, we have used the well-known Risk Matrix methodology to determine the relative risk that several common attacks have in a VLC network. Four examples: a War Driving, a Queensland alike Denial of Service, a Preshared Key Cracking, and an Evil Twin attack, illustrate the utilization of the methodology over a VLC implementation. The used attacks also covered the different areas delimited by the attack taxonomy used in this work. By defining and determining which attacks present a greater risk, the results of this work provide a lead into which areas should be invested to increase the safety of VLC networks. PMID:29186184

Considerations on Visible Light Communication security by applying the Risk Matrix methodology for risk assessment.

PubMed

Marin-Garcia, Ignacio; Chavez-Burbano, Patricia; Guerra, Victor; Rabadan, Jose; Perez-Jimenez, Rafael

2017-01-01

Visible Light Communications (VLC) is a cutting edge technology for data communication that is being considered to be implemented in a wide range of applications such as Inter-vehicle communication or Local Area Network (LAN) communication. As a novel technology, some aspects of the implementation of VLC have not been deeply considered or tested. Among these aspects, security and its implementation may become an obstacle for VLCs broad usage. In this article, we have used the well-known Risk Matrix methodology to determine the relative risk that several common attacks have in a VLC network. Four examples: a War Driving, a Queensland alike Denial of Service, a Preshared Key Cracking, and an Evil Twin attack, illustrate the utilization of the methodology over a VLC implementation. The used attacks also covered the different areas delimited by the attack taxonomy used in this work. By defining and determining which attacks present a greater risk, the results of this work provide a lead into which areas should be invested to increase the safety of VLC networks.

The politics of Golden Rice

PubMed Central

Dubock, Adrian

2014-01-01

Genetic knowledge applicable to crop improvement has erupted over the past 60 years, and the techniques of introducing genes from one organism to another have enabled new varieties of crops not achievable by previously available methodologies of crop breeding. Research and particularly development of these GMO-crops to a point where they are useful for growers and consumers in most countries is subject to complex national and international rules arising out of the UN's Cartagena Protocol on Biosafety to the Convention on Biological Diversity, with 167 country signatories. (The USA and Canada are not signatories.) The Protocol was developed based on concerns initially expressed in the 1970's that such technology presented unusual risks to man and the environment. Those ideas have comprehensively and authoritatively been proven to be wrong. The Protocol has nevertheless spawned significant regulatory obstacles to the development of GMO-crop technology at great cost to global society and in conflict with many other UN objectives. The suspicion induced by the Protocol is also widely used, overtly or covertly, for political purposes. These points are illustrated by reference to the not-for-profit Golden Rice project. PMID:25437240

The politics of Golden Rice.

PubMed

Dubock, Adrian

2014-07-03

Genetic knowledge applicable to crop improvement has erupted over the past 60 years, and the techniques of introducing genes from one organism to another have enabled new varieties of crops not achievable by previously available methodologies of crop breeding. Research and particularly development of these GMO-crops to a point where they are useful for growers and consumers in most countries is subject to complex national and international rules arising out of the UN's Cartagena Protocol on Biosafety to the Convention on Biological Diversity, with 167 country signatories. (The USA and Canada are not signatories.) The Protocol was developed based on concerns initially expressed in the 1970's that such technology presented unusual risks to man and the environment. Those ideas have comprehensively and authoritatively been proven to be wrong. The Protocol has nevertheless spawned significant regulatory obstacles to the development of GMO-crop technology at great cost to global society and in conflict with many other UN objectives. The suspicion induced by the Protocol is also widely used, overtly or covertly, for political purposes. These points are illustrated by reference to the not-for-profit Golden Rice project.

Robustness of free and pinned spiral waves against breakup by electrical forcing in excitable chemical media.

PubMed

Phantu, Metinee; Sutthiopad, Malee; Luengviriya, Jiraporn; Müller, Stefan C; Luengviriya, Chaiya

2017-04-01

We present an investigation on the breakup of free and pinned spiral waves under an applied electrical current in the Belousov-Zhabotinsky reaction. Spiral fronts propagating towards the negative electrode are decelerated. A breakup of the spiral waves occurs when some segments of the fronts are stopped by a sufficiently strong electrical current. In the absence of obstacles (i.e., free spiral waves), the critical value of the electrical current for the wave breakup increases with the excitability of the medium. For spiral waves pinned to circular obstacles, the critical electrical current increases with the obstacle diameter. Analysis of spiral dynamics shows that the enhancement of the robustness against the breakup of both free and pinned spiral waves is originated by the increment of wave speed when either the excitability is strengthened or the obstacle size is enlarged. The experimental findings are reproduced by numerical simulations using the Oregonator model. In addition, the simulations reveal that the robustness against the forced breakup increases with the activator level in both cases of free and pinned spiral waves.

Key Health Information Technologies and Related Issues for Iran: A Qualitative Study.

PubMed

Hemmat, Morteza; Ayatollahi, Haleh; Maleki, Mohammadreza; Saghafi, Fatemeh

2018-01-01

Planning for the future of Health Information Technology (HIT) requires applying a systematic approach when conducting foresight studies. The aim of this study was to identify key health information technologies and related issues for Iran until 2025. This was a qualitative study and the participants included experts and policy makers in the field of health information technology. In-depth semi-structured interviews were conducted and data were analyzed by using framework analysis and MAXQDA software. The findings revealed that the development of national health information network, electronic health records, patient health records, a cloud-based service center, interoperability standards, patient monitoring technologies, telehealth, mhealth, clinical decision support systems, health information technology and mhealth infrastructure were found to be the key technologies for the future. These technologies could influence the economic, organizational and individual levels. To achieve them, the economic and organizational obstacles need to be overcome. In this study, a number of key technologies and related issues were identified. This approach can help to focus on the most important technologies in the future and to priorities these technologies for better resource allocation and policy making.

Web-based training and interrater reliability testing for scoring the Hamilton Depression Rating Scale.

PubMed

Rosen, Jules; Mulsant, Benoit H; Marino, Patricia; Groening, Christopher; Young, Robert C; Fox, Debra

2008-10-30

Despite the importance of establishing shared scoring conventions and assessing interrater reliability in clinical trials in psychiatry, these elements are often overlooked. Obstacles to rater training and reliability testing include logistic difficulties in providing live training sessions, or mailing videotapes of patients to multiple sites and collecting the data for analysis. To address some of these obstacles, a web-based interactive video system was developed. It uses actors of diverse ages, gender and race to train raters how to score the Hamilton Depression Rating Scale and to assess interrater reliability. This system was tested with a group of experienced and novice raters within a single site. It was subsequently used to train raters of a federally funded multi-center clinical trial on scoring conventions and to test their interrater reliability. The advantages and limitations of using interactive video technology to improve the quality of clinical trials are discussed.

Awareness and Detection of Traffic and Obstacles Using Synthetic and Enhanced Vision Systems

NASA Technical Reports Server (NTRS)

Bailey, Randall E.

2012-01-01

Research literature are reviewed and summarized to evaluate the awareness and detection of traffic and obstacles when using Synthetic Vision Systems (SVS) and Enhanced Vision Systems (EVS). The study identifies the critical issues influencing the time required, accuracy, and pilot workload associated with recognizing and reacting to potential collisions or conflicts with other aircraft, vehicles and obstructions during approach, landing, and surface operations. This work considers the effect of head-down display and head-up display implementations of SVS and EVS as well as the influence of single and dual pilot operations. The influences and strategies of adding traffic information and cockpit alerting with SVS and EVS were also included. Based on this review, a knowledge gap assessment was made with recommendations for ground and flight testing to fill these gaps and hence, promote the safe and effective implementation of SVS/EVS technologies for the Next Generation Air Transportation System

GeoSTAR - A Synthetic Aperture Microwave Sounder for Geostationary Missions

NASA Technical Reports Server (NTRS)

Lambrigtsen, Bjorn; Wilson, William; Tanner, Alan; Kangaslahti, Pekka

2004-01-01

The Geostationary Synthetic Thinned Aperture Radiometer (GeoSTAR) is a new microwave atmospheric sounder under development. It will bring capabilities similar to those now available on low-earth orbiting environmental satellites to geostationary orbit - where such capabilities have not been available. GeoSTAR will synthesize the multimeter aperture needed to achieve the required spatial resolution, which will overcome the obstacle that has prevented a GEO microwave sounder from being implemented until now. The synthetic aperture approach has until recently not been feasible, due to the high power needed to operate the on-board high-speed massively parallel processing system required for 2D-synthesis, as well as a number of system and calibration obstacles. The development effort under way at JPL, with important contributions from the Goddard Space Flight Center and the University of Michigan, is intended to demonstrate the measurement concept and retire much of the technology risk.

Obstacles to prior art searching by the trilateral patent offices: empirical evidence from International Search Reports.

PubMed

Wada, Tetsuo

Despite many empirical studies having been carried out on examiner patent citations, few have scrutinized the obstacles to prior art searching when adding patent citations during patent prosecution at patent offices. This analysis takes advantage of the longitudinal gap between an International Search Report (ISR) as required by the Patent Cooperation Treaty (PCT) and subsequent national examination procedures. We investigate whether several kinds of distance actually affect the probability that prior art is detected at the time of an ISR; this occurs much earlier than in national phase examinations. Based on triadic PCT applications between 2002 and 2005 for the trilateral patent offices (the European Patent Office, the US Patent and Trademark Office, and the Japan Patent Office) and their family-level citations made by the trilateral offices, we find evidence that geographical distance negatively affects the probability of capture of prior patents in an ISR. In addition, the technological complexity of an application negatively affects the probability of capture, whereas the volume of forward citations of prior art affects it positively. These results demonstrate the presence of obstacles to searching at patent offices, and suggest ways to design work sharing by patent offices, such that the duplication of search costs arises only when patent office search horizons overlap.

Evacuation simulation with consideration of obstacle removal and using game theory

NASA Astrophysics Data System (ADS)

Lin, Guan-Wen; Wong, Sai-Keung

2018-06-01

In this paper, we integrate a cellular automaton model with game theory to simulate crowd evacuation from a room with consideration of obstacle removal. The room has one or more exits, one of which is blocked by obstacles. The obstacles at the exit can be removed by volunteers. We investigate the cooperative and defective behaviors of pedestrians during evacuation. The yielder game and volunteer's dilemma game are employed to resolve interpedestrian conflict. An anticipation floor field is proposed to guide the pedestrians to avoid obstacles that are being removed. We conducted experiments to determine how a variety of conditions affect overall crowd evacuation and volunteer evacuation times. The conditions were the start time of obstacle removal, number of obstacles, placement of obstacles, time spent in obstacle removal, strength of the anticipation floor field, and obstacle visibility distance. We demonstrate how reciprocity can be achieved among pedestrians and increases the efficiency of the entire evacuation process.

The addition of stripes (a version of the 'horizontal-vertical illusion') increases foot clearance when crossing low-height obstacles.

PubMed

Foster, Richard J; Buckley, John G; Whitaker, David; Elliott, David B

2016-07-01

Trips over obstacles are one of the main causes of falling in older adults, with vision playing an important role in successful obstacle negotiation. We determined whether a horizontal-vertical illusion, superimposed onto low-height obstacles to create a perceived increase in obstacle height, increased foot clearances during obstacle negotiation thus reducing the likelihood of tripping. Eleven adults (mean ± 1 SD: age 27.3 ± 5.1 years) negotiated obstacles of varying heights (3, 5, 7 cm) with four different appearance conditions; two were obstacles with a horizontal-vertical illusion (vertical stripes of different thickness) superimposed on the front, one was a plain obstacle and the fourth a plain obstacle with a horizontal black line painted on the top edge. Foot clearance parameters were compared across conditions. Both illusions led to a significant increase in foot clearance when crossing the obstacle, compared to the plain condition, irrespective of obstacle height. Superimposing a horizontal-vertical illusion onto low-height obstacles can increase foot clearance, and its use on the floor section of a double-glazing door frame for example may reduce the incidence of tripping in the home. Practitioner Summary: Low-height obstacles such as the floor section of a double-glazing door frame are potential tripping hazards. In a gait lab-based study we found that a horizontal-vertical illusion superimposed onto low-height obstacles led to significantly higher foot clearances; indicating their potential as a useful safety measure.

Asymptotically Optimal Motion Planning for Learned Tasks Using Time-Dependent Cost Maps

PubMed Central

Bowen, Chris; Ye, Gu; Alterovitz, Ron

2015-01-01

In unstructured environments in people’s homes and workspaces, robots executing a task may need to avoid obstacles while satisfying task motion constraints, e.g., keeping a plate of food level to avoid spills or properly orienting a finger to push a button. We introduce a sampling-based method for computing motion plans that are collision-free and minimize a cost metric that encodes task motion constraints. Our time-dependent cost metric, learned from a set of demonstrations, encodes features of a task’s motion that are consistent across the demonstrations and, hence, are likely required to successfully execute the task. Our sampling-based motion planner uses the learned cost metric to compute plans that simultaneously avoid obstacles and satisfy task constraints. The motion planner is asymptotically optimal and minimizes the Mahalanobis distance between the planned trajectory and the distribution of demonstrations in a feature space parameterized by the locations of task-relevant objects. The motion planner also leverages the distribution of the demonstrations to significantly reduce plan computation time. We demonstrate the method’s effectiveness and speed using a small humanoid robot performing tasks requiring both obstacle avoidance and satisfaction of learned task constraints. Note to Practitioners Motivated by the desire to enable robots to autonomously operate in cluttered home and workplace environments, this paper presents an approach for intuitively training a robot in a manner that enables it to repeat the task in novel scenarios and in the presence of unforeseen obstacles in the environment. Based on user-provided demonstrations of the task, our method learns features of the task that are consistent across the demonstrations and that we expect should be repeated by the robot when performing the task. We next present an efficient algorithm for planning robot motions to perform the task based on the learned features while avoiding obstacles. We demonstrate the effectiveness of our motion planner for scenarios requiring transferring a powder and pushing a button in environments with obstacles, and we plan to extend our results to more complex tasks in the future. PMID:26279642

Medical Representatives' Intention to Use Information Technology in Pharmaceutical Marketing.

PubMed

Kwak, Eun-Seon; Chang, Hyejung

2016-10-01

Electronic detailing (e-detailing), the use of electronic devices to facilitate sales presentations to physicians, has been adopted and expanded in the pharmaceutical industry. To maximize the potential outcome of e-detailing, it is important to understand medical representatives (MRs)' behavior and attitude to e-detailing. This study investigates how information technology devices such as laptop computers and tablet PCs are utilized in pharmaceutical marketing, and it analyzes the factors influencing MRs' intention to use devices. This study has adopted and modified the theory of Roger's diffusion of innovation model and the technology acceptance model. To test the model empirically, a questionnaire survey was conducted with 221 MRs who were working in three multinational or eleven domestic pharmaceutical companies in Korea. Overall, 28% and 35% of MRs experienced using laptop computers and tablet PCs in pharmaceutical marketing, respectively. However, the rates were different across different groups of MRs, categorized by age, education level, position, and career. The results showed that MRs' intention to use information technology devices was significantly influenced by perceived usefulness in general. Perceived ease of use, organizational and individual innovativeness, and several MR characteristics were also found to have significant impacts. This study provides timely information about e-detailing devices to marketing managers and policy makers in the pharmaceutical industry for successful marketing strategy development by understanding the needs of MRs' intention to use information technology. Further in-depth study should be conducted to understand obstacles and limitations and to improve the strategies for better marketing tools.

Three-dimensional landing zone joint capability technology demonstration

NASA Astrophysics Data System (ADS)

Savage, James; Goodrich, Shawn; Ott, Carl; Szoboszlay, Zoltan; Perez, Alfonso; Soukup, Joel; Burns, H. N.

2014-06-01

The Three-Dimensional Landing Zone (3D-LZ) Joint Capability Technology Demonstration (JCTD) is a 27-month program to develop an integrated LADAR and FLIR capability upgrade for USAF Combat Search and Rescue HH-60G Pave Hawk helicopters through a retrofit of current Raytheon AN/AAQ-29 turret systems. The 3D-LZ JCTD builds upon a history of technology programs using high-resolution, imaging LADAR to address rotorcraft cruise, approach to landing, landing, and take-off in degraded visual environments with emphasis on brownout, cable warning and obstacle avoidance, and avoidance of controlled flight into terrain. This paper summarizes ladar development, flight test milestones, and plans for a final flight test demonstration and Military Utility Assessment in 2014.

Supporting research sites in resource-limited settings: Challenges in implementing IT infrastructure

PubMed Central

Whalen, Christopher; Donnell, Deborah; Tartakovsky, Michael

2014-01-01

As Information and Communication Technology infrastructure becomes more reliable, new methods of Electronic Data Capture (EDC), datamarts/Data warehouses, and mobile computing provide platforms for rapid coordination of international research projects and multisite studies. However, despite the increasing availability of internet connectivity and communication systems in remote regions of the world, there are still significant obstacles. Sites with poor infrastructure face serious challenges participating in modern clinical and basic research, particularly that relying on EDC and internet communication technologies. This report discusses our experiences in supporting research in resource-limited settings (RLS). We describe examples of the practical and ethical/regulatory challenges raised by use of these newer technologies for data collection in multisite clinical studies. PMID:24321986

Business of reliability

NASA Astrophysics Data System (ADS)

Engel, Pierre

1999-12-01

The presentation is organized around three themes: (1) The decrease of reception equipment costs allows non-Remote Sensing organization to access a technology until recently reserved to scientific elite. What this means is the rise of 'operational' executive agencies considering space-based technology and operations as a viable input to their daily tasks. This is possible thanks to totally dedicated ground receiving entities focusing on one application for themselves, rather than serving a vast community of users. (2) The multiplication of earth observation platforms will form the base for reliable technical and financial solutions. One obstacle to the growth of the earth observation industry is the variety of policies (commercial versus non-commercial) ruling the distribution of the data and value-added products. In particular, the high volume of data sales required for the return on investment does conflict with traditional low-volume data use for most applications. Constant access to data sources supposes monitoring needs as well as technical proficiency. (3) Large volume use of data coupled with low- cost equipment costs is only possible when the technology has proven reliable, in terms of application results, financial risks and data supply. Each of these factors is reviewed. The expectation is that international cooperation between agencies and private ventures will pave the way for future business models. As an illustration, the presentation proposes to use some recent non-traditional monitoring applications, that may lead to significant use of earth observation data, value added products and services: flood monitoring, ship detection, marine oil pollution deterrent systems and rice acreage monitoring.

Training toddlers seated on mobile robots to drive indoors amidst obstacles.

PubMed

Chen, Xi; Ragonesi, Christina; Galloway, James C; Agrawal, Sunil K

2011-06-01

Mobility is a causal factor in development. Children with mobility impairments may rely upon power mobility for independence and thus require advanced driving skills to function independently. Our previous studies show that while infants can learn to drive directly to a goal using conventional joysticks in several months of training, they are unable in this timeframe to acquire the advanced skill to avoid obstacles while driving. Without adequate driving training, children are unable to explore the environment safely, the consequences of which may in turn increase their risk for developmental delay. The goal of this research therefore is to train children seated on mobile robots to purposefully and safely drive indoors. In this paper, we present results where ten typically-developing toddlers are trained to drive a robot within an obstacle course. We also report a case study with a toddler with spina-bifida who cannot independently walk. Using algorithms based on artificial potential fields to avoid obstacles, we create force field on the joystick that trains the children to navigate while avoiding obstacles. In this "assist-as-needed" approach, if the child steers the joystick outside a force tunnel centered on the desired direction, the driver experiences a bias force on the hand. Our results suggest that the use of a force-feedback joystick may yield faster learning than the use of a conventional joystick.

Generic Dynamic Environment Perception Using Smart Mobile Devices

PubMed Central

Danescu, Radu; Itu, Razvan; Petrovai, Andra

2016-01-01

The driving environment is complex and dynamic, and the attention of the driver is continuously challenged, therefore computer based assistance achieved by processing image and sensor data may increase traffic safety. While active sensors and stereovision have the advantage of obtaining 3D data directly, monocular vision is easy to set up, and can benefit from the increasing computational power of smart mobile devices, and from the fact that almost all of them come with an embedded camera. Several driving assistance application are available for mobile devices, but they are mostly targeted for simple scenarios and a limited range of obstacle shapes and poses. This paper presents a technique for generic, shape independent real-time obstacle detection for mobile devices, based on a dynamic, free form 3D representation of the environment: the particle based occupancy grid. Images acquired in real time from the smart mobile device’s camera are processed by removing the perspective effect and segmenting the resulted bird-eye view image to identify candidate obstacle areas, which are then used to update the occupancy grid. The occupancy grid tracked cells are grouped into obstacles depicted as cuboids having position, size, orientation and speed. The easy to set up system is able to reliably detect most obstacles in urban traffic, and its measurement accuracy is comparable to a stereovision system. PMID:27763501

Design and evaluation of an autonomous, obstacle avoiding, flight control system using visual sensors

NASA Astrophysics Data System (ADS)

Crawford, Bobby Grant

In an effort to field smaller and cheaper Uninhabited Aerial Vehicles (UAVs), the Army has expressed an interest in an ability of the vehicle to autonomously detect and avoid obstacles. Current systems are not suitable for small aircraft. NASA Langley Research Center has developed a vision sensing system that uses small semiconductor cameras. The feasibility of using this sensor for the purpose of autonomous obstacle avoidance by a UAV is the focus of the research presented in this document. The vision sensor characteristics are modeled and incorporated into guidance and control algorithms designed to generate flight commands based on obstacle information received from the sensor. The system is evaluated by simulating the response to these flight commands using a six degree-of-freedom, non-linear simulation of a small, fixed wing UAV. The simulation is written using the MATLAB application and runs on a PC. Simulations were conducted to test the longitudinal and lateral capabilities of the flight control for a range of airspeeds, camera characteristics, and wind speeds. Results indicate that the control system is suitable for obstacle avoiding flight control using the simulated vision system. In addition, a method for designing and evaluating the performance of such a system has been developed that allows the user to easily change component characteristics and evaluate new systems through simulation.

Automated image-based phenotypic analysis in zebrafish embryos

PubMed Central

Vogt, Andreas; Cholewinski, Andrzej; Shen, Xiaoqiang; Nelson, Scott; Lazo, John S.; Tsang, Michael; Hukriede, Neil A.

2009-01-01

Presently, the zebrafish is the only vertebrate model compatible with contemporary paradigms of drug discovery. Zebrafish embryos are amenable to automation necessary for high-throughput chemical screens, and optical transparency makes them potentially suited for image-based screening. However, the lack of tools for automated analysis of complex images presents an obstacle to utilizing the zebrafish as a high-throughput screening model. We have developed an automated system for imaging and analyzing zebrafish embryos in multi-well plates regardless of embryo orientation and without user intervention. Images of fluorescent embryos were acquired on a high-content reader and analyzed using an artificial intelligence-based image analysis method termed Cognition Network Technology (CNT). CNT reliably detected transgenic fluorescent embryos (Tg(fli1:EGFP)y1) arrayed in 96-well plates and quantified intersegmental blood vessel development in embryos treated with small molecule inhibitors of anigiogenesis. The results demonstrate it is feasible to adapt image-based high-content screening methodology to measure complex whole organism phenotypes. PMID:19235725

Biodynamic profiling of three-dimensional tissue growth techniques

NASA Astrophysics Data System (ADS)

Sun, Hao; Merrill, Dan; Turek, John; Nolte, David

2016-03-01

Three-dimensional tissue culture presents a more biologically relevant environment in which to perform drug development than conventional two-dimensional cell culture. However, obtaining high-content information from inside three dimensional tissue has presented an obstacle to rapid adoption of 3D tissue culture for pharmaceutical applications. Biodynamic imaging is a high-content three-dimensional optical imaging technology based on low-coherence interferometry and digital holography that uses intracellular dynamics as high-content image contrast. In this paper, we use biodynamic imaging to compare pharmaceutical responses to Taxol of three-dimensional multicellular spheroids grown by three different growth techniques: rotating bioreactor, hanging-drop and plate-grown spheroids. The three growth techniques have systematic variations among tissue cohesiveness and intracellular activity and consequently display different pharmacodynamics under identical drug dose conditions. The in vitro tissue cultures are also compared to ex vivo living biopsies. These results demonstrate that three-dimensional tissue cultures are not equivalent, and that drug-response studies must take into account the growth method.

A review on bioconversion of lignocellulosic biomass to H2: Key challenges and new insights.

PubMed

Ren, Nan-Qi; Zhao, Lei; Chen, Chuan; Guo, Wan-Qian; Cao, Guang-Li

2016-09-01

With the increasing energy crisis and rising concern over climate change, the development of clean alternative energy sources is of great importance. Biohydrogen produced from lignocellulosic biomass is a promising candidate, because of its positives such as readily available, no harmful emissions, environment friendly, efficient, and renewable. However, obstacles still exist to enable the commercialization of biological hydrogen production from lignocellulosic biomass. Thus the objective of this work is to provide update information about the recent progress on lignocellulosic hydrogen conversion via dark fermentation. In this review, the most important technologies associated with lignocellulosic hydrogen fermentation were covered. Firstly, pretreatment methods for better utilization of lignocellulosic biomass are presented, at the same time, hydrolysis methods assisting to achieve efficient hydrogen fermentation were discussed. Afterwards, issues related to bioprocesses for hydrogen production purposes were presented. Additionally, the paper gave challenges and new insights of lignocellulosic biohydrogen production. Copyright © 2016. Published by Elsevier Ltd.

Proceedings of the signature series event of the international society for cellular therapy: "Advancements in cellular therapies and regenerative medicine in digestive diseases," London, United Kingdom, May 3, 2017.

PubMed

Ciccocioppo, Rachele; Dos Santos, Claudia C; Baumgart, Daniel C; Cangemi, Giuseppina C; Cardinale, Vincenzo; Ciacci, Carolina; De Coppi, Paolo; Haldar, Debashis; Klersy, Catherine; Nostro, M Cristina; Ott, Michael; Piemonti, Lorenzo; Tomei, Alice A; Uygun, Basak; Vetrano, Stefania; Orlando, Giuseppe

2018-03-01

A summary of the First Signature Series Event, "Advancements in Cellular Therapies and Regenerative Medicine for Digestive Diseases," held on May 3, 2017, in London, United Kingdom, is presented. Twelve speakers from three continents covered major topics in the areas of cellular therapy and regenerative medicine applied to liver and gastrointestinal medicine as well as to diabetes mellitus. Highlights from their presentations, together with an overview of the global impact of digestive diseases and a proposal for a shared online collection and data-monitoring platform tool, are included in this proceedings. Although growing evidence demonstrate the feasibility and safety of exploiting cell-based technologies for the treatment of digestive diseases, regulatory and methodological obstacles will need to be overcome before the successful implementation in the clinic of these novel attractive therapeutic strategies. Copyright © 2017 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

[The age of Gutenberg is over: a consideration of medical education--past, present and future].

PubMed

Burg, G; French, L E

2012-04-01

Education is the basis for reliable medical care and medical progress. Our medical knowledge has increased more in the past 50 years than in the 500 years before. The spatial and human resource capacity of our universities cannot cope with the existing academic structures and needs. Part of the problem can be solved by "blended learning", that is a combination of traditional teaching methods (frontal lectures, courses, bedside teaching) with supplementary web-based e-learning. In addition to conveying a sound basic knowledge, the ability to cope with modern media and prepare for lifelong learning must also be taught. Out of the large number of e-learning platforms for undergraduate students offered in the internet, we present the program DOIT (Dermatology Online with Interactive Technology; http://www.swisdom.org) and the program Dermokrates (http://www.Dermokrates.com) of the German, Austrian and Swiss Dermatological Societies for postgraduate Continuing Medical Education (CME). The biggest obstacle in the implementation of new developments is the stubborn adherence to traditional structures.

Microrobotics surveillance: discrete and continuous starbot

NASA Astrophysics Data System (ADS)

Mayyas, M.; Lee, W. H.; Stephanou, Harry

2011-05-01

This paper focuses on robotic technologies and operational capabilities of multiscale robots that demonstrate a unique class of Microsystems with the ability to navigate diverse terrains and environments. We introduce two classes of robots which combine multiple locomotion modalities including centimeter scale Discrete and Continuous robots which are referred here by D-Starbot and C-Starbot, respectively. The first generation of the robots were obtained to allow rapid shape reconfiguration and flipping recovery to accomplish tasks such as lowering and raising to dexterously go over and under obstacles, deform to roll over hostile location as well as squeezing through opening smaller than its sizes. The D-Starbot is based on novel mechanisms that allow shape reconfiguration to accomplish tasks such as lowering and raising to go over and under obstacles as well as squeezing through small voids. The CStarbot is a new class of foldable robots that is generally designed to provide a high degree of manufacturability. It consists of flexible structures that are built out of composite laminates with embedded microsystems. The design concept of C-Starbot are suitable for robots that could emulate and combine multiple locomotion modalities such as walking, running, crawling, gliding, clinging, climbing, flipping and jumping. The first generation of C-Starbot has centimeter scale structure consisting of flexible flaps, each being coupled with muscle-like mechanism. Untethered D-Starbot designs are prototyped and tested for multifunctional locomotion capabilities in indoor and outdoor environments. We present foldable mechanism and initial prototypes of C-Starbot capable of hopping and squeezing at different environments. The kinematic performance of flexible robots is thoroughly presented using the large elastic deflection of a single arm which is actuated by pulling force acting at variable angles and under payload and friction forces.

A Real-Time Reaction Obstacle Avoidance Algorithm for Autonomous Underwater Vehicles in Unknown Environments.

PubMed

Yan, Zheping; Li, Jiyun; Zhang, Gengshi; Wu, Yi

2018-02-02

A novel real-time reaction obstacle avoidance algorithm (RRA) is proposed for autonomous underwater vehicles (AUVs) that must adapt to unknown complex terrains, based on forward looking sonar (FLS). To accomplish this algorithm, obstacle avoidance rules are planned, and the RRA processes are split into five steps Introduction only lists 4 so AUVs can rapidly respond to various environment obstacles. The largest polar angle algorithm (LPAA) is designed to change detected obstacle's irregular outline into a convex polygon, which simplifies the obstacle avoidance process. A solution is designed to solve the trapping problem existing in U-shape obstacle avoidance by an outline memory algorithm. Finally, simulations in three unknown obstacle scenes are carried out to demonstrate the performance of this algorithm, where the obtained obstacle avoidance trajectories are safety, smooth and near-optimal.

Foam flows through a local constriction

NASA Astrophysics Data System (ADS)

Chevalier, T.; Koivisto, J.; Shmakova, N.; Alava, M. J.; Puisto, A.; Raufaste, C.; Santucci, S.

2017-11-01

We present an experimental study of the flow of a liquid foam, composed of a monolayer of millimetric bubbles, forced to invade an inhomogeneous medium at a constant flow rate. To model the simplest heterogeneous fracture medium, we use a Hele-Shaw cell consisting of two glass plates separated by a millimetric gap, with a local constriction. This single defect localized in the middle of the cell reduces locally its gap thickness, and thus its local permeability. We investigate here the influence of the geometrical property of the defect, specifically its height, on the average steady-state flow of the foam. In the frame of the flowing foam, we can observe a clear recirculation around the obstacle, characterized by a quadrupolar velocity field with a negative wake downstream the obstacle, which intensity evolves systematically with the obstacle height.

Lessons for continuing medical education from simulation research in undergraduate and graduate medical education: effectiveness of continuing medical education: American College of Chest Physicians Evidence-Based Educational Guidelines.

PubMed

McGaghie, William C; Siddall, Viva J; Mazmanian, Paul E; Myers, Janet

2009-03-01

Simulation technology is widely used in undergraduate and graduate medical education as well as for personnel training and evaluation in other healthcare professions. Simulation provides safe and effective opportunities for learners at all levels to practice and acquire clinical skills needed for patient care. A growing body of research evidence documents the utility of simulation technology for educating healthcare professionals. However, simulation has not been widely endorsed or used for continuing medical education (CME). This article reviews and evaluates evidence from studies on simulation technology in undergraduate and graduate medical education and addresses its implications for CME. The Agency for Healthcare Research and Quality Evidence Report suggests that simulation training is effective, especially for psychomotor and communication skills, but that the strength of the evidence is low. In another review, the Best Evidence Medical Education collaboration supported the use of simulation technology, focusing on high-fidelity medical simulations under specific conditions. Other studies enumerate best practices that include mastery learning, deliberate practice, and recognition and attention to cultural barriers within the medical profession that present obstacles to wider use of this technology. Simulation technology is a powerful tool for the education of physicians and other healthcare professionals at all levels. Its educational effectiveness depends on informed use for trainees, including providing feedback, engaging learners in deliberate practice, integrating simulation into an overall curriculum, as well as on the instruction and competence of faculty in its use. Medical simulation complements, but does not replace, educational activities based on real patient-care experiences.

Use of VR Technology and Passive Haptics for MANPADS Training System

DTIC Science & Technology

2017-09-01

this setup also does not offer a variety of challenging scenarios needed for good training as the aircraft are mostly flying in landing or take-off... customized high-fidelity immersive training facilities are limited. Moreover, low trainee throughput from such high-end facilities is an ongoing obstacle...opportunities allow few operators to fire during live exercises. Simulation training is effective, but customized high-fidelity immersive training

An integrated approach to distance learning with digital video in the French-speaking Virtual Medical University.

PubMed

Dufour, J C; Cuggia, M; Soula, G; Spector, M; Kohler, F

2007-01-01

The aim of the French-speaking Virtual Medical University project (UMVF) is to share common resources and specific tools in order to improve medical training. Digital video on IP is an attractive tool for higher education but there are a number of obstacles to widespread implementation. This paper describes the UMVF approach to integrating digital video technologies and services in educational projects.

Safe Operations of Unmanned Systems for Reconnaissance in Complex Environments Army Technology Objective (SOURCE ATO)

DTIC Science & Technology

2011-04-25

must adapt its planning to vehicle size, shape, wheelbase, wheel and axle configuration, the specific obstacle-crossing capabilities of the vehicle...scalability of the ANS is a consequence of making each sensing modality capable of performing reasonable perception tasks while allowing a wider...autonomous system design achieves flexibility by exploiting redundant sensing modalities where possible, and by a decision-making process that

Key management and encryption under the bounded storage model.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Draelos, Timothy John; Neumann, William Douglas; Lanzone, Andrew J.

2005-11-01

There are several engineering obstacles that need to be solved before key management and encryption under the bounded storage model can be realized. One of the critical obstacles hindering its adoption is the construction of a scheme that achieves reliable communication in the event that timing synchronization errors occur. One of the main accomplishments of this project was the development of a new scheme that solves this problem. We show in general that there exist message encoding techniques under the bounded storage model that provide an arbitrarily small probability of transmission error. We compute the maximum capacity of this channelmore » using the unsynchronized key-expansion as side-channel information at the decoder and provide tight lower bounds for a particular class of key-expansion functions that are pseudo-invariant to timing errors. Using our results in combination with Dziembowski et al. [11] encryption scheme we can construct a scheme that solves the timing synchronization error problem. In addition to this work we conducted a detailed case study of current and future storage technologies. We analyzed the cost, capacity, and storage data rate of various technologies, so that precise security parameters can be developed for bounded storage encryption schemes. This will provide an invaluable tool for developing these schemes in practice.« less

Towards Autonomous Operations of the Robonaut 2 Humanoid Robotic Testbed

NASA Technical Reports Server (NTRS)

Badger, Julia; Nguyen, Vienny; Mehling, Joshua; Hambuchen, Kimberly; Diftler, Myron; Luna, Ryan; Baker, William; Joyce, Charles

2016-01-01

The Robonaut project has been conducting research in robotics technology on board the International Space Station (ISS) since 2012. Recently, the original upper body humanoid robot was upgraded by the addition of two climbing manipulators ("legs"), more capable processors, and new sensors, as shown in Figure 1. While Robonaut 2 (R2) has been working through checkout exercises on orbit following the upgrade, technology development on the ground has continued to advance. Through the Active Reduced Gravity Offload System (ARGOS), the Robonaut team has been able to develop technologies that will enable full operation of the robotic testbed on orbit using similar robots located at the Johnson Space Center. Once these technologies have been vetted in this way, they will be implemented and tested on the R2 unit on board the ISS. The goal of this work is to create a fully-featured robotics research platform on board the ISS to increase the technology readiness level of technologies that will aid in future exploration missions. Technology development has thus far followed two main paths, autonomous climbing and efficient tool manipulation. Central to both technologies has been the incorporation of a human robotic interaction paradigm that involves the visualization of sensory and pre-planned command data with models of the robot and its environment. Figure 2 shows screenshots of these interactive tools, built in rviz, that are used to develop and implement these technologies on R2. Robonaut 2 is designed to move along the handrails and seat track around the US lab inside the ISS. This is difficult for many reasons, namely the environment is cluttered and constrained, the robot has many degrees of freedom (DOF) it can utilize for climbing, and remote commanding for precision tasks such as grasping handrails is time-consuming and difficult. Because of this, it is important to develop the technologies needed to allow the robot to reach operator-specified positions as autonomously as possible. The most important progress in this area has been the work towards efficient path planning for high DOF, highly constrained systems. Other advances include machine vision algorithms for localizing and automatically docking with handrails, the ability of the operator to place obstacles in the robot's virtual environment, autonomous obstacle avoidance techniques, and constraint management.

Stepping back to see the big picture: when obstacles elicit global processing.

PubMed

Marguc, Janina; Förster, Jens; Van Kleef, Gerben A

2011-11-01

Can obstacles prompt people to look at the "big picture" and open up their minds? Do the cognitive effects of obstacles extend beyond the tasks with which they interfere? These questions were addressed in 6 studies involving both physical and nonphysical obstacles and different measures of global versus local processing styles. Perceptual scope increased after participants solved anagrams in the presence, rather than the absence, of an auditory obstacle (random words played in the background; Study 1), particularly among individuals low in volatility (i.e., those who are inclined to stay engaged and finish what they do; Study 4). It also increased immediately after participants encountered a physical obstacle while navigating a maze (Study 3A) and when compared with doing nothing (Study 3B). Conceptual scope increased after participants solved anagrams while hearing random numbers framed as an "obstacle to overcome" rather than a "distraction to ignore" (Study 2) and after participants navigated a maze with a physical obstacle, compared with a maze without a physical obstacle, but only when trait (Study 5) or state (Study 6) volatility was low. Results suggest that obstacles trigger an "if obstacle, then start global processing" response, primarily when people are inclined to stay engaged and finish ongoing activities. Implications for dealing with life's obstacles and related research are discussed.

Influences of periodic mechanical deformation on pinned spiral waves

NASA Astrophysics Data System (ADS)

Chen, Jiang-Xing; Peng, Liang; Zheng, Qiang; Zhao, Ye-Hua; Ying, He-Ping

2014-09-01

In a generic model of excitable media, we study the behavior of spiral waves interacting with obstacles and their dynamics under the influences of simple periodic mechanical deformation (PMD). Depending on the characteristics of the obstacles, i.e., size and excitability, the rotation of a pinned spiral wave shows different scenarios, e.g., embedding into or anchoring on an obstacle. Three different drift phenomena induced by PMD are observed: scattering on small partial-excitable obstacles, meander-induced unpinning on big partial-excitable obstacles, and drifting around small unexcitable obstacles. Their underlying mechanisms are discussed. The dependence of the threshold amplitude of PMD on the characteristics of the obstacles to successfully remove pinned spiral waves on big partial-excitable obstacles is studied.

Vision Based Obstacle Detection in Uav Imaging

NASA Astrophysics Data System (ADS)

Badrloo, S.; Varshosaz, M.

2017-08-01

Detecting and preventing incidence with obstacles is crucial in UAV navigation and control. Most of the common obstacle detection techniques are currently sensor-based. Small UAVs are not able to carry obstacle detection sensors such as radar; therefore, vision-based methods are considered, which can be divided into stereo-based and mono-based techniques. Mono-based methods are classified into two groups: Foreground-background separation, and brain-inspired methods. Brain-inspired methods are highly efficient in obstacle detection; hence, this research aims to detect obstacles using brain-inspired techniques, which try to enlarge the obstacle by approaching it. A recent research in this field, has concentrated on matching the SIFT points along with, SIFT size-ratio factor and area-ratio of convex hulls in two consecutive frames to detect obstacles. This method is not able to distinguish between near and far obstacles or the obstacles in complex environment, and is sensitive to wrong matched points. In order to solve the above mentioned problems, this research calculates the dist-ratio of matched points. Then, each and every point is investigated for Distinguishing between far and close obstacles. The results demonstrated the high efficiency of the proposed method in complex environments.

Strategies for obstacle avoidance during walking in the cat.

PubMed

Chu, Kevin M I; Seto, Sandy H; Beloozerova, Irina N; Marlinski, Vladimir

2017-08-01

Avoiding obstacles is essential for successful navigation through complex environments. This study aimed to clarify what strategies are used by a typical quadruped, the cat, to avoid obstacles during walking. Four cats walked along a corridor 2.5 m long and 25 or 15 cm wide. Obstacles, small round objects 2.5 cm in diameter and 1 cm in height, were placed on the floor in various locations. Movements of the paw were recorded with a motion capture and analysis system (Visualeyez, PTI). During walking in the wide corridor, cats' preferred strategy for avoiding a single obstacle was circumvention, during which the stride direction changed while stride duration and swing-to-stride duration ratio were preserved. Another strategy, stepping over the obstacle, was used during walking in the narrow corridor, when lateral deviations of walking trajectory were restricted. Stepping over the obstacle involved changes in two consecutive strides. The stride preceding the obstacle was shortened, and swing-to-stride ratio was reduced. The obstacle was negotiated in the next stride of increased height and normal duration and swing-to-stride ratio. During walking on a surface with multiple obstacles, both strategies were used. To avoid contact with the obstacle, cats placed the paw away from the object at a distance roughly equal to the diameter of the paw. During obstacle avoidance cats prefer to alter muscle activities without altering the locomotor rhythm. We hypothesize that a choice of the strategy for obstacle avoidance is determined by minimizing the complexity of neuro-motor processes required to achieve the behavioral goal. NEW & NOTEWORTHY In a study of feline locomotor behavior we found that the preferred strategy to avoid a small obstacle is circumvention. During circumvention, stride direction changes but length and temporal structure are preserved. Another strategy, stepping over the obstacle, is used in narrow walkways. During overstepping, two strides adjust. A stride preceding the obstacle decreases in length and duration. The following stride negotiating the obstacle increases in height while retaining normal temporal structure and nearly normal length. Copyright © 2017 the American Physiological Society.

Affordable Manufacturing Technologies Being Developed for Actively Cooled Ceramic Components

NASA Technical Reports Server (NTRS)

Bhatt, Ramakrishna T.

1999-01-01

Efforts to improve the performance of modern gas turbine engines have imposed increasing service temperature demands on structural materials. Through active cooling, the useful temperature range of nickel-base superalloys in current gas turbine engines has been extended, but the margin for further improvement appears modest. Because of their low density, high-temperature strength, and high thermal conductivity, in situ toughened silicon nitride ceramics have received a great deal of attention for cooled structures. However, high processing costs have proven to be a major obstacle to their widespread application. Advanced rapid prototyping technology, which is developing rapidly, offers the possibility of an affordable manufacturing approach.

Overview of existing cartilage repair technology.

PubMed

McNickle, Allison G; Provencher, Matthew T; Cole, Brian J

2008-12-01

Currently, autologous chondrocyte implantation and osteochondral grafting bridge the gap between palliation of cartilage injury and resurfacing via arthroplasty. Emerging technologies seek to advance first generation techniques and accomplish several goals including predictable outcomes, cost-effective technology, single-stage procedures, and creation of durable repair tissue. The biologic pipeline represents a variety of technologies including synthetics, scaffolds, cell therapy, and cell-infused matrices. Synthetic constructs, an alternative to biologic repair, resurface a focal chondral defect rather than the entire joint surface. Scaffolds are cell-free constructs designed as a biologic "net" to augment marrow stimulation techniques. Minced cartilage technology uses stabilized autologous or allogeneic fragments in 1-stage transplantation. Second and third generation cell-based methods include alternative membranes, chondrocyte seeding, and culturing onto scaffolds. Despite the promising early results of these products, significant technical obstacles remain along with unknown long-term durability. The vast array of developing technologies has exceptional promise and the potential to revolutionize the cartilage treatment algorithm within the next decade.

"We noticed that suddenly the country has become full of MRI". Policy makers' views on diffusion and use of health technologies in Iran

PubMed Central

2010-01-01

Objective Uncontrolled proliferation of health technologies (HT) is one contributor to the increasing pressure on health systems to adopt new technologies. With limited resources, policy-makers encounter difficulties in fulfilling their responsibility to meet the healthcare needs of the population. The aim of this study is to explore how policy-makers' reason about the diffusion and utilization of health technologies in Iran using magnetic resonance imaging (MRI) and interferon beta as tracers. Method This qualitative exploration complements quantitative data generated in a research project investigating the diffusion and utilization of MRI and interferon beta in Iran. Qualitative semi-structured interviews were conducted with 13 informants in different positions and levels of authority in the Ministry of Health (MOH), University of Medical Sciences, Health Insurance Organizations, and Parliament. The data was analysed using the framework approach. Findings Although policy-makers appeared to be positive to health technology assessment (HTA), the processes of policy-making described by the interviewees did not seem to be based on a full understanding of this (discipline). Several obstacles to applying knowledge about HT and HTA were described. The current official plan for MRI adoption and diffusion in the country was said not to be followed, and no such plan was described for interferon beta. Instead, market forces such as advertising, and physician and consumer demand, appear to have strong influence on HT diffusion and use. Dual practice may have increased the induced demand and also reduced the supervision of the private sector by the MOH. Conclusion Management instability and lack of coordination in the MOH were found to be important obstacles to accumulation of knowledge and experience which, in turn, could have led to suboptimal managerial and policy-making processes. Furthermore marketing should be controlled in order to avoid creating unnecessary patient demands and negative influences on physicians' behavior. PMID:20370906

"We noticed that suddenly the country has become full of MRI". Policy makers' views on diffusion and use of health technologies in Iran.

PubMed

Palesh, Mohammad; Tishelman, Carol; Fredrikson, Sten; Jamshidi, Hamidreza; Tomson, Göran; Emami, Azita

2010-04-06

Uncontrolled proliferation of health technologies (HT) is one contributor to the increasing pressure on health systems to adopt new technologies. With limited resources, policy-makers encounter difficulties in fulfilling their responsibility to meet the healthcare needs of the population. The aim of this study is to explore how policy-makers' reason about the diffusion and utilization of health technologies in Iran using magnetic resonance imaging (MRI) and interferon beta as tracers. This qualitative exploration complements quantitative data generated in a research project investigating the diffusion and utilization of MRI and interferon beta in Iran. Qualitative semi-structured interviews were conducted with 13 informants in different positions and levels of authority in the Ministry of Health (MOH), University of Medical Sciences, Health Insurance Organizations, and Parliament. The data was analysed using the framework approach. Although policy-makers appeared to be positive to health technology assessment (HTA), the processes of policy-making described by the interviewees did not seem to be based on a full understanding of this (discipline). Several obstacles to applying knowledge about HT and HTA were described. The current official plan for MRI adoption and diffusion in the country was said not to be followed, and no such plan was described for interferon beta. Instead, market forces such as advertising, and physician and consumer demand, appear to have strong influence on HT diffusion and use. Dual practice may have increased the induced demand and also reduced the supervision of the private sector by the MOH. Management instability and lack of coordination in the MOH were found to be important obstacles to accumulation of knowledge and experience which, in turn, could have led to suboptimal managerial and policy-making processes. Furthermore marketing should be controlled in order to avoid creating unnecessary patient demands and negative influences on physicians' behavior.

Implementation status of accrual accounting system in health sector.

PubMed

Mehrolhassani, Mohammad Hossien; Khayatzadeh-Mahani, Akram; Emami, Mozhgan

2014-07-29

Management of financial resources in health systems is one of the major issues of concern for policy makers globally. As a sub-set of financial management, accounting system is of paramount importance. In this paper, which presents part of the results of a wider research project on transition process from a cash accounting system to an accrual accounting system, we look at the impact of components of change on implementation of the new system. Implementing changes is fraught with many obstacles and surveying these challenges will help policy makers to better overcome them. The study applied a quantitative manner in 2012 at Kerman University of Medical Science in Iran. For the evaluation, a teacher made valid questionnaire with Likert scale was used (Cranach's alpha of 0.89) which included 7 change components in accounting system. The study population was 32 subordinate units of Kerman University of Medical Sciences and for data analysis, descriptive and inferential statistics and correlation coefficient in SPSS version 19 were used. Level of effect of all components on the implementation was average downward (5.06±1.86), except for the component "management & leadership (3.46±2.25)" (undesirable from external evaluators' viewpoint) and "technology (6.61±1.92) and work processes (6.35±2.19)" (middle to high from internal evaluators' viewpoint). Results showed that the establishment of accrual accounting system faces infrastructural challenges, especially the components of leadership and management and followers. As such, developing effective measures to overcome implementation obstacles should target these components.

[A strategy of constructing the technological system for quality control of Chinese medicine based on process control and management].

PubMed

Cheng, Yi-Yu; Qian, Zhong-Zhi; Zhang, Bo-Li

2017-01-01

The current situation, bottleneck problems and severe challenges in quality control technology of Chinese Medicine (CM) are briefly described. It is presented to change the phenomenon related to the post-test as the main means and contempt for process control in drug regulation, reverse the situation of neglecting the development of process control and management technology for pharmaceutical manufacture and reconstruct the technological system for quality control of CM products. The regulation and technology system based on process control and management for controlling CM quality should be established to solve weighty realistic problems of CM industry from the root causes, including backwardness of quality control technology, weakness of quality risk control measures, poor reputation of product quality and so on. By this way, the obstacles from poor controllability of CM product quality could be broken. Concentrating on those difficult problems and weak links in the technical field of CM quality control, it is proposed to build CMC (Chemistry, Manufacturing and Controls) regulation for CM products with Chinese characteristics and promote the regulation international recognition as soon as possible. The CMC technical framework, which is clinical efficacy-oriented, manufacturing manner-centered and process control-focused, was designed. To address the clinical characteristics of traditional Chinese medicine (TCM) and the production feature of CM manufacture, it is suggested to establish quality control engineering for CM manufacturing by integrating pharmaceutical analysis, TCM chemistry, TCM pharmacology, pharmaceutical engineering, control engineering, management engineering and other disciplines. Further, a theoretical model of quality control engineering for CM manufacturing and the methodology of digital pharmaceutical engineering are proposed. A technology pathway for promoting CM standard and realizing the strategic goal of CM internationalization is elaborated. Copyright© by the Chinese Pharmaceutical Association.

3D Numerical Simulation on the Rockslide Generated Tsunamis

NASA Astrophysics Data System (ADS)

Chuang, M.; Wu, T.; Wang, C.; Chu, C.

2013-12-01

The rockslide generated tsunami is one of the most devastating nature hazards. However, the involvement of the moving obstacle and dynamic free-surface movement makes the numerical simulation a difficult task. To describe both the fluid motion and solid movement at the same time, we newly developed a two-way fully-coupled moving solid algorithm with 3D LES turbulent model. The free-surface movement is tracked by volume of fluid (VOF) method. The two-step projection method is adopted to solve the Navier-Stokes type government equations. In the new moving solid algorithm, a fictitious body force is implicitly prescribed in MAC correction step to make the cell-center velocity satisfied with the obstacle velocity. We called this method the implicit velocity method (IVM). Because no extra terms are added to the pressure Poission correction, the pressure field of the fluid part is stable, which is the key of the two-way fluid-solid coupling. Because no real solid material is presented in the IVM, the time marching step is not restricted to the smallest effective grid size. Also, because the fictitious force is implicitly added to the correction step, the resulting velocity is accurate and fully coupled with the resulting pressure field. We validated the IVM by simulating a floating box moving up and down on the free-surface. We presented the time-history obstacle trajectory and compared it with the experimental data. Very accurate result can be seen in terms of the oscillating amplitude and the period (Fig. 1). We also presented the free-surface comparison with the high-speed snapshots. At the end, the IVM was used to study the rock-slide generated tsunamis (Liu et al., 2005). Good validations on the slide trajectory and the free-surface movement will be presented in the full paper. From the simulation results (Fig. 2), we observed that the rockslide generated waves are manly caused by the rebounding waves from two sides of the sliding rock after the water is dragging down by the solid downward motion. We also found that the turbulence has minor effect to the main flow field. The rock size, rock density, and the steepness of the slope were analyzed to understand their effects to the maximum runup height. The detailed algorithm of IVM, the validation, the simulation and analysis of rockslide tsunami will be presented in the full paper. Figure 1. Time-history trajectory of obstacle for the floating obstacle simulation. Figure 2. Snapshots of the free-surface elevation with streamlines for the rockslide tsunami simulation.

Creating a Visualization Powerwall

NASA Technical Reports Server (NTRS)

Miller, B. H.; Lambert, J.; Zamora, K.

1996-01-01

From Introduction: This paper presents the issues of constructing a Visualization Powerwall. For each hardware component, the requirements, options an our solution are presented. This is followed by a short description of each pilot project. In the summary, current obstacles and options discovered along the way are presented.

Paving the Way to Successful Implementation: Identifying Key Barriers to Use of Technology-Based Therapeutic Tools for Behavioral Health Care.

PubMed

Ramsey, Alex; Lord, Sarah; Torrey, John; Marsch, Lisa; Lardiere, Michael

2016-01-01

This study aimed to identify barriers to use of technology for behavioral health care from the perspective of care decision makers at community behavioral health organizations. As part of a larger survey of technology readiness, 260 care decision makers completed an open-ended question about perceived barriers to use of technology. Using the Consolidated Framework for Implementation Research (CFIR), qualitative analyses yielded barrier themes related to characteristics of technology (e.g., cost and privacy), potential end users (e.g., technology literacy and attitudes about technology), organization structure and climate (e.g., budget and infrastructure), and factors external to organizations (e.g., broadband accessibility and reimbursement policies). Number of reported barriers was higher among respondents representing agencies with lower annual budgets and smaller client bases relative to higher budget, larger clientele organizations. Individual barriers were differentially associated with budget, size of client base, and geographic location. Results are discussed in light of implementation science frameworks and proactive strategies to address perceived obstacles to adoption and use of technology-based behavioral health tools.

Paving the Way to Successful Implementation: Identifying Key Barriers to Use of Technology-Based Therapeutic Tools for Behavioral Health Care

PubMed Central

Ramsey, Alex; Lord, Sarah; Torrey, John; Marsch, Lisa; Lardiere, Michael

2014-01-01

This study aimed to identify barriers to use of technology for behavioral health care from the perspective of care decision-makers at community behavioral health organizations. As part of a larger survey of technology readiness, 260 care decision-makers completed an open-ended question about perceived barriers to use of technology. Using the Consolidated Framework for Implementation Research (CFIR), qualitative analyses yielded barrier themes related to characteristics of technology (e.g., cost, privacy), potential end-users (e.g., technology literacy, attitudes about technology), organization structure and climate (e.g., budget, infrastructure), and factors external to organizations (e.g., broadband accessibility, reimbursement policies). Number of reported barriers was higher among respondents representing agencies with lower annual budgets and smaller client bases relative to higher budget, larger clientele organizations. Individual barriers were differentially associated with budget, size of client base, and geographic location. Results are discussed in light of implementation science frameworks and proactive strategies to address perceived obstacles to adoption and use of technology-based behavioral health tools. PMID:25192755

Laser range measurement for a satellite navigation scheme and mid-range path selection and obstacle avoidance. M.S. Thesis

NASA Technical Reports Server (NTRS)

Zuraski, G. D.

1972-01-01

The functions of a laser rangefinder on board an autonomous Martian roving vehicle are discussed. The functions are: (1) navigation by means of a passive satellite and (2) mid-range path selection and obstacle avoidance. The feasibility of using a laser to make the necessary range measurements is explored and a preliminary design is presented. The two uses of the rangefinder dictate widely different operating parameters making it impossible to use the same system for both functions.

Analysis of the minimum swerving distance for the development of a motorcycle autonomous braking system.

PubMed

Giovannini, Federico; Savino, Giovanni; Pierini, Marco; Baldanzini, Niccolò

2013-10-01

In the recent years the autonomous emergency brake (AEB) was introduced in the automotive field to mitigate the injury severity in case of unavoidable collisions. A crucial element for the activation of the AEB is to establish when the obstacle is no longer avoidable by lateral evasive maneuvers (swerving). In the present paper a model to compute the minimum swerving distance needed by a powered two-wheeler (PTW) to avoid the collision against a fixed obstacle, named last-second swerving model (Lsw), is proposed. The effectiveness of the model was investigated by an experimental campaign involving 12 volunteers riding a scooter equipped with a prototype autonomous emergency braking, named motorcycle autonomous emergency braking system (MAEB). The tests showed the performance of the model in evasive trajectory computation for different riding styles and fixed obstacles. Copyright © 2013 Elsevier Ltd. All rights reserved.

Bionic Vision-Based Intelligent Power Line Inspection System

PubMed Central

Ma, Yunpeng; He, Feijia; Xu, Jinxin

2017-01-01

Detecting the threats of the external obstacles to the power lines can ensure the stability of the power system. Inspired by the attention mechanism and binocular vision of human visual system, an intelligent power line inspection system is presented in this paper. Human visual attention mechanism in this intelligent inspection system is used to detect and track power lines in image sequences according to the shape information of power lines, and the binocular visual model is used to calculate the 3D coordinate information of obstacles and power lines. In order to improve the real time and accuracy of the system, we propose a new matching strategy based on the traditional SURF algorithm. The experimental results show that the system is able to accurately locate the position of the obstacles around power lines automatically, and the designed power line inspection system is effective in complex backgrounds, and there are no missing detection instances under different conditions. PMID:28203269

Inverse obstacle problem for the scalar Helmholtz equation

NASA Astrophysics Data System (ADS)

Crosta, Giovanni F.

1994-07-01

The method presented is aimed at identifying the shape of an axially symmetric, sound soft acoustic scatterer from knowledge of the incident plane wave and of the scattering amplitude. The method relies on the approximate back propagation (ABP) of the estimated far field coefficients to the obstacle boundary and iteratively minimizes a boundary defect, without the addition of any penalty term. The ABP operator owes its structure to the properties of complete families of linearly independent solutions of Helmholtz equation. If the obstacle is known, as it happens in simulations, the theory also provides some independent means of predicting the performance of the ABP method. The ABP algorithm and the related computer code are outlined. Several reconstruction examples are considered, where noise is added to the estimated far field coefficients and other errors are deliberately introduced in the data. Many numerical and graphical results are provided.

Cultured meat: every village its own factory?

PubMed

van der Weele, Cor; Tramper, Johannes

2014-06-01

Rising global demand for meat will result in increased environmental pollution, energy consumption, and animal suffering. Cultured meat, produced in an animal-cell cultivation process, is a technically feasible alternative lacking these disadvantages, provided that an animal-component-free growth medium can be developed. Small-scale production looks particularly promising, not only technologically but also for societal acceptance. Economic feasibility, however, emerges as the real obstacle. Copyright © 2014 Elsevier Ltd. All rights reserved.

CLICK: The USGS Center for LIDAR Information Coordination & Knowledge

USGS Publications Warehouse

Menig, Jordan C.; Stoker, Jason M.

2007-01-01

While this technology has proven its use as a mapping tool - effective for generating bare earth DEMs at high resolutions (1-3 m) and with high vertical accuracies (15-18 cm) - obstacles remain for its application as a remote sensing tool: * The high cost of collecting LIDAR * The steep learning curve on research and application of using the entire point cloud * The challenges of discovering whether data exist for regions of interest

JPRS Report, Science & Technology, Japan, 4th Intelligent Robots Symposium, Volume 2

DTIC Science & Technology

1989-03-16

accidents caused by strikes by robots,5 a quantitative model for safety evaluation,6 and evaluations of actual systems7 in order to contribute to...Mobile Robot Position Referencing Using Map-Based Vision Systems.... 160 Safety Evaluation of Man-Robot System 171 Fuzzy Path Pattern of Automatic...camera are made after the robot stops to prevent damage from occurring through obstacle interference. The position of the camera is indicated on the

Laser radar system for obstacle avoidance

NASA Astrophysics Data System (ADS)

Bers, Karlheinz; Schulz, Karl R.; Armbruster, Walter

2005-09-01

The threat of hostile surveillance and weapon systems require military aircraft to fly under extreme conditions such as low altitude, high speed, poor visibility and incomplete terrain information. The probability of collision with natural and man-made obstacles during such contour missions is high if detection capability is restricted to conventional vision aids. Forward-looking scanning laser radars which are build by the EADS company and presently being flight tested and evaluated at German proving grounds, provide a possible solution, having a large field of view, high angular and range resolution, a high pulse repetition rate, and sufficient pulse energy to register returns from objects at distances of military relevance with a high hit-and-detect probability. The development of advanced 3d-scene analysis algorithms had increased the recognition probability and reduced the false alarm rate by using more readily recognizable objects such as terrain, poles, pylons, trees, etc. to generate a parametric description of the terrain surface as well as the class, position, orientation, size and shape of all objects in the scene. The sensor system and the implemented algorithms can be used for other applications such as terrain following, autonomous obstacle avoidance, and automatic target recognition. This paper describes different 3D-imaging ladar sensors with unique system architecture but different components matched for different military application. Emphasis is laid on an obstacle warning system with a high probability of detection of thin wires, the real time processing of the measured range image data, obstacle classification und visualization.

A nonlinear model predictive control formulation for obstacle avoidance in high-speed autonomous ground vehicles in unstructured environments

NASA Astrophysics Data System (ADS)

Liu, Jiechao; Jayakumar, Paramsothy; Stein, Jeffrey L.; Ersal, Tulga

2018-06-01

This paper presents a nonlinear model predictive control (MPC) formulation for obstacle avoidance in high-speed, large-size autono-mous ground vehicles (AGVs) with high centre of gravity (CoG) that operate in unstructured environments, such as military vehicles. The term 'unstructured' in this context denotes that there are no lanes or traffic rules to follow. Existing MPC formulations for passenger vehicles in structured environments do not readily apply to this context. Thus, a new nonlinear MPC formulation is developed to navigate an AGV from its initial position to a target position at high-speed safely. First, a new cost function formulation is used that aims to find the shortest path to the target position, since no reference trajectory exists in unstructured environments. Second, a region partitioning approach is used in conjunction with a multi-phase optimal control formulation to accommodate the complicated forms the obstacle-free region can assume due to the presence of multiple obstacles in the prediction horizon in an unstructured environment. Third, the no-wheel-lift-off condition, which is the major dynamical safety concern for high-speed, high-CoG AGVs, is ensured by limiting the steering angle within a range obtained offline using a 14 degrees-of-freedom vehicle dynamics model. Thus, a safe, high-speed navigation is enabled in an unstructured environment. Simulations of an AGV approaching multiple obstacles are provided to demonstrate the effectiveness of the algorithm.

Evaluation of 3M(TM) Scotchlite linear delineation system : final report.

DOT National Transportation Integrated Search

2004-09-01

Major construction projects present many hazards for drivers to negotiate. Detours, lane shifts and confusing curves : present unique challenges to all drivers. At night, the difficulties in negotiating these obstacles are amplified due to : reduced ...

A Real-Time Reaction Obstacle Avoidance Algorithm for Autonomous Underwater Vehicles in Unknown Environments

PubMed Central

Yan, Zheping; Li, Jiyun; Zhang, Gengshi; Wu, Yi

2018-01-01

A novel real-time reaction obstacle avoidance algorithm (RRA) is proposed for autonomous underwater vehicles (AUVs) that must adapt to unknown complex terrains, based on forward looking sonar (FLS). To accomplish this algorithm, obstacle avoidance rules are planned, and the RRA processes are split into five steps Introduction only lists 4 so AUVs can rapidly respond to various environment obstacles. The largest polar angle algorithm (LPAA) is designed to change detected obstacle’s irregular outline into a convex polygon, which simplifies the obstacle avoidance process. A solution is designed to solve the trapping problem existing in U-shape obstacle avoidance by an outline memory algorithm. Finally, simulations in three unknown obstacle scenes are carried out to demonstrate the performance of this algorithm, where the obtained obstacle avoidance trajectories are safety, smooth and near-optimal. PMID:29393915

The study of stereo vision technique for the autonomous vehicle

NASA Astrophysics Data System (ADS)

Li, Pei; Wang, Xi; Wang, Jiang-feng

2015-08-01

The stereo vision technology by two or more cameras could recovery 3D information of the field of view. This technology can effectively help the autonomous navigation system of unmanned vehicle to judge the pavement conditions within the field of view, and to measure the obstacles on the road. In this paper, the stereo vision technology in measuring the avoidance of the autonomous vehicle is studied and the key techniques are analyzed and discussed. The system hardware of the system is built and the software is debugged, and finally the measurement effect is explained by the measured data. Experiments show that the 3D reconstruction, within the field of view, can be rebuilt by the stereo vision technology effectively, and provide the basis for pavement condition judgment. Compared with unmanned vehicle navigation radar used in measuring system, the stereo vision system has the advantages of low cost, distance and so on, it has a good application prospect.

Improving Global Access to New Vaccines: Intellectual Property, Technology Transfer, and Regulatory Pathways

PubMed Central

2014-01-01

The 2012 World Health Assembly Global Vaccine Action Plan called for global access to new vaccines within 5 years of licensure. Current approaches have proven insufficient to achieve sustainable vaccine pricing within such a timeline. Paralleling the successful strategy of generic competition to bring down drug prices, a clear consensus is emerging that market entry of multiple suppliers is a critical factor in expeditiously bringing down prices of new vaccines. In this context, key target objectives for improving access to new vaccines include overcoming intellectual property obstacles, streamlining regulatory pathways for biosimilar vaccines, and reducing market entry timelines for developing-country vaccine manufacturers by transfer of technology and know-how. I propose an intellectual property, technology, and know-how bank as a new approach to facilitate widespread access to new vaccines in low- and middle-income countries by efficient transfer of patented vaccine technologies to multiple developing-country vaccine manufacturers. PMID:25211753

Radio frequency identification (RFID) in health care: privacy and security concerns limiting adoption.

PubMed

Rosenbaum, Benjamin P

2014-03-01

Radio frequency identification (RFID) technology has been implemented in a wide variety of industries. Health care is no exception. This article explores implementations and limitations of RFID in several health care domains: authentication, medication safety, patient tracking, and blood transfusion medicine. Each domain has seen increasing utilization of unique applications of RFID technology. Given the importance of protecting patient and data privacy, potential privacy and security concerns in each domain are discussed. Such concerns, some of which are inherent to existing RFID hardware and software technology, may limit ubiquitous adoption. In addition, an apparent lack of security standards within the RFID domain and specifically health care may also hinder the growth and utility of RFID within health care for the foreseeable future. Safeguarding the privacy of patient data may be the most important obstacle to overcome to allow the health care industry to take advantage of the numerous benefits RFID technology affords.

Exploring Social Networking Technologies as Tools for HIV Prevention for Men Who Have Sex With Men.

PubMed

Ramallo, Jorge; Kidder, Thomas; Albritton, Tashuna; Blick, Gary; Pachankis, John; Grandelski, Valen; Grandeleski, Valen; Kershaw, Trace

2015-08-01

Social networking technologies are influential among men who have sex with men (MSM) and may be an important strategy for HIV prevention. We conducted focus groups with HIV positive and negative participants. Almost all participants used social networking sites to meet new friends and sexual partners. The main obstacle to effective HIV prevention campaigns in social networking platforms was stigmatization based on homosexuality as well as HIV status. Persistent stigma associated with HIV status and disclosure was cited as a top reason for avoiding HIV-related conversations while meeting new partners using social technologies. Further, social networking sites have different social etiquettes and rules that may increase HIV risk by discouraging HIV status disclosure. Overall, successful interventions for MSM using social networking technologies must consider aspects of privacy, stigma, and social norms in order to enact HIV reduction among MSM.

Improving global access to new vaccines: intellectual property, technology transfer, and regulatory pathways.

PubMed

Crager, Sara Eve

2014-11-01

The 2012 World Health Assembly Global Vaccine Action Plan called for global access to new vaccines within 5 years of licensure. Current approaches have proven insufficient to achieve sustainable vaccine pricing within such a timeline. Paralleling the successful strategy of generic competition to bring down drug prices, a clear consensus is emerging that market entry of multiple suppliers is a critical factor in expeditiously bringing down prices of new vaccines. In this context, key target objectives for improving access to new vaccines include overcoming intellectual property obstacles, streamlining regulatory pathways for biosimilar vaccines, and reducing market entry timelines for developing-country vaccine manufacturers by transfer of technology and know-how. I propose an intellectual property, technology, and know-how bank as a new approach to facilitate widespread access to new vaccines in low- and middle-income countries by efficient transfer of patented vaccine technologies to multiple developing-country vaccine manufacturers.

[Improving global access to new vaccines: intellectual property, technology transfer, and regulatory pathways].

PubMed

Crager, Sara Eve

2015-01-01

The 2012 World Health Assembly Global Vaccine Action Plan called for global access to new vaccines within 5 years of licensure. Current approaches have proven insufficient to achieve sustainable vaccine pricing within such a timeline. Paralleling the successful strategy of generic competition to bring down drug prices, a clear consensus is emerging that market entry of multiple suppliers is a critical factor in expeditiously bringing down prices of new vaccines. In this context, key target objectives for improving access to new vaccines include overcoming intellectual property obstacles, streamlining regulatory pathways for biosimilar vaccines, and reducing market entry timelines for developing-country vaccine manufacturers by transfer of technology and know-how. I propose an intellectual property, technology, and know-how bank as a new approach to facilitate widespread access to new vaccines in low- and middle-income countries by efficient transfer of patented vaccine technologies to multiple developing-country vaccine manufacturers.

EXPLORING SOCIAL NETWORKING TECHNOLOGIES AS TOOLS FOR HIV PREVENTION FOR MEN WHO HAVE SEX WITH MEN

PubMed Central

Ramallo, Jorge; Kidder, Thomas; Albritton, Tashuna; Blick, Gary; Pachankis, John; Grandelski, Valen; Kershaw, Trace

2017-01-01

Social networking technologies are influential among men who have sex with men (MSM) and may be an important strategy for HIV prevention. We conducted focus groups with HIV positive and negative participants. Almost all participants used social networking sites to meet new friends and sexual partners. The main obstacle to effective HIV prevention campaigns in social networking platforms was stigmatization based on homosexuality as well as HIV status. Persistent stigma associated with HIV status and disclosure was cited as a top reason for avoiding HIV-related conversations while meeting new partners using social technologies. Further, social networking sites have different social etiquettes and rules that may increase HIV risk by discouraging HIV status disclosure. Overall, successful interventions for MSM using social networking technologies must consider aspects of privacy, stigma, and social norms in order to enact HIV reduction among MSM. PMID:26241381

Key Health Information Technologies and Related Issues for Iran: A Qualitative Study

PubMed Central

Hemmat, Morteza; Ayatollahi, Haleh; Maleki, Mohammadreza; Saghafi, Fatemeh

2018-01-01

Background and Objective: Planning for the future of Health Information Technology (HIT) requires applying a systematic approach when conducting foresight studies. The aim of this study was to identify key health information technologies and related issues for Iran until 2025. Methods: This was a qualitative study and the participants included experts and policy makers in the field of health information technology. In-depth semi-structured interviews were conducted and data were analyzed by using framework analysis and MAXQDA software. Results: The findings revealed that the development of national health information network, electronic health records, patient health records, a cloud-based service center, interoperability standards, patient monitoring technologies, telehealth, mhealth, clinical decision support systems, health information technology and mhealth infrastructure were found to be the key technologies for the future. These technologies could influence the economic, organizational and individual levels. To achieve them, the economic and organizational obstacles need to be overcome. Conclusion: In this study, a number of key technologies and related issues were identified. This approach can help to focus on the most important technologies in the future and to priorities these technologies for better resource allocation and policy making. PMID:29854016

A low-cost approach for rapidly creating demonstration models for hands-on learning

NASA Astrophysics Data System (ADS)

Kinzli, Kristoph-Dietrich; Kunberger, Tanya; O'Neill, Robert; Badir, Ashraf

2018-01-01

Demonstration models allow students to readily grasp theory and relate difficult concepts and equations to real life. However drawbacks of using these demonstration models are that they are can be costly to purchase from vendors or take a significant amount of time to build. These two limiting factors can pose a significant obstacle for adding demonstrations to the curriculum. This article presents an assignment to overcome these obstacles, which has resulted in 36 demonstration models being added to the curriculum. The article also presents the results of student performance on course objectives as a result of the developed models being used in the classroom. Overall, significant improvement in student learning outcomes, due to the addition of demonstration models, has been observed.

Range Sensor-Based Efficient Obstacle Avoidance through Selective Decision-Making.

PubMed

Shim, Youngbo; Kim, Gon-Woo

2018-03-29

In this paper, we address a collision avoidance method for mobile robots. Many conventional obstacle avoidance methods have been focused solely on avoiding obstacles. However, this can cause instability when passing through a narrow passage, and can also generate zig-zag motions. We define two strategies for obstacle avoidance, known as Entry mode and Bypass mode. Entry mode is a pattern for passing through the gap between obstacles, while Bypass mode is a pattern for making a detour around obstacles safely. With these two modes, we propose an efficient obstacle avoidance method based on the Expanded Guide Circle (EGC) method with selective decision-making. The simulation and experiment results show the validity of the proposed method.

Effects of soft interactions and bound mobility on diffusion in crowded environments: a model of sticky and slippery obstacles

NASA Astrophysics Data System (ADS)

Stefferson, Michael W.; Norris, Samantha L.; Vernerey, Franck J.; Betterton, Meredith D.; E Hough, Loren

2017-08-01

Crowded environments modify the diffusion of macromolecules, generally slowing their movement and inducing transient anomalous subdiffusion. The presence of obstacles also modifies the kinetics and equilibrium behavior of tracers. While previous theoretical studies of particle diffusion have typically assumed either impenetrable obstacles or binding interactions that immobilize the particle, in many cellular contexts bound particles remain mobile. Examples include membrane proteins or lipids with some entry and diffusion within lipid domains and proteins that can enter into membraneless organelles or compartments such as the nucleolus. Using a lattice model, we studied the diffusive movement of tracer particles which bind to soft obstacles, allowing tracers and obstacles to occupy the same lattice site. For sticky obstacles, bound tracer particles are immobile, while for slippery obstacles, bound tracers can hop without penalty to adjacent obstacles. In both models, binding significantly alters tracer motion. The type and degree of motion while bound is a key determinant of the tracer mobility: slippery obstacles can allow nearly unhindered diffusion, even at high obstacle filling fraction. To mimic compartmentalization in a cell, we examined how obstacle size and a range of bound diffusion coefficients affect tracer dynamics. The behavior of the model is similar in two and three spatial dimensions. Our work has implications for protein movement and interactions within cells.