WorldWideScience

Sample records for coverage path planning

  1. Intelligent coverage path planning for agricultural robots and autonomous machines on three-dimensional terrain

    DEFF Research Database (Denmark)

    Hameed, Ibahim

    2014-01-01

    Field operations should be done in a manner that minimizes time and travels over the field surface. Automated and intelligent path planning can help to find the best coverage path so that costs of various field operations can be minimized. The algorithms for generating an optimized field coverage...

  2. An Efficient Energy Constraint Based UAV Path Planning for Search and Coverage

    OpenAIRE

    Gramajo, German; Shankar, Praveen

    2017-01-01

    A path planning strategy for a search and coverage mission for a small UAV that maximizes the area covered based on stored energy and maneuverability constraints is presented. The proposed formulation has a high level of autonomy, without requiring an exact choice of optimization parameters, and is appropriate for real-time implementation. The computed trajectory maximizes spatial coverage while closely satisfying terminal constraints on the position of the vehicle and minimizing the time of ...

  3. An Efficient Energy Constraint Based UAV Path Planning for Search and Coverage

    Directory of Open Access Journals (Sweden)

    German Gramajo

    2017-01-01

    Full Text Available A path planning strategy for a search and coverage mission for a small UAV that maximizes the area covered based on stored energy and maneuverability constraints is presented. The proposed formulation has a high level of autonomy, without requiring an exact choice of optimization parameters, and is appropriate for real-time implementation. The computed trajectory maximizes spatial coverage while closely satisfying terminal constraints on the position of the vehicle and minimizing the time of flight. Comparisons of this formulation to a path planning algorithm based on those with time constraint show equivalent coverage performance but improvement in prediction of overall mission duration and accuracy of the terminal position of the vehicle.

  4. Complete coverage path planning of a random polygon - A FroboMind component

    DEFF Research Database (Denmark)

    Aslund, Sebastian; Jensen, Kjeld; Jørgensen, Rasmus Nyholm

    solution where all the steps in the process is included: Segmentation of a data set, creation of a configuration space, decomposition of a polygon, global and local path planning. To achieve this, a series of known algorithms are used including some tweaks and improvements to create a solid foundation...

  5. Side-to-side 3D coverage path planning approach for agricultural robots to minimize skip/overlap areas between swaths

    DEFF Research Database (Denmark)

    Hameed, Ibrahim; la Cour-Harbo, Anders; Osen, O. L.

    2016-01-01

    Automated path planning is important for the automation and optimization of field operations. It can provide the waypoints required for guidance, navigation and control of agricultural robots and autonomous tractors throughout the execution of these field operations. In agriculture, field...... operations are usually repeated in the same field and from year to year as well, therefore, it should be carried out in a manner that minimizes environmental impact and cost taking into account the topographic land features. Current 3D terrain field coverage path planning algorithms are simply 2D coverage...

  6. Optimal Path Planning and Control of Quadrotor Unmanned Aerial Vehicle for Area Coverage

    Science.gov (United States)

    Fan, Jiankun

    An Unmanned Aerial Vehicle (UAV) is an aircraft without a human pilot on board. Its flight is controlled either autonomously by computers onboard the vehicle, or remotely by a pilot on the ground, or by another vehicle. In recent years, UAVs have been used more commonly than prior years. The example includes areo-camera where a high speed camera was attached to a UAV which can be used as an airborne camera to obtain aerial video. It also could be used for detecting events on ground for tasks such as surveillance and monitoring which is a common task during wars. Similarly UAVs can be used for relaying communication signal during scenarios when regular communication infrastructure is destroyed. The objective of this thesis is motivated from such civilian operations such as search and rescue or wildfire detection and monitoring. One scenario is that of search and rescue where UAV's objective is to geo-locate a person in a given area. The task is carried out with the help of a camera whose live feed is provided to search and rescue personnel. For this objective, the UAV needs to carry out scanning of the entire area in the shortest time. The aim of this thesis to develop algorithms to enable a UAV to scan an area in optimal time, a problem referred to as "Coverage Control" in literature. The thesis focuses on a special kind of UAVs called "quadrotor" that is propelled with the help of four rotors. The overall objective of this thesis is achieved via solving two problems. The first problem is to develop a dynamic control model of quadrtor. In this thesis, a proportional-integral-derivative controller (PID) based feedback control system is developed and implemented on MATLAB's Simulink. The PID controller helps track any given trajectory. The second problem is to design a trajectory that will fulfill the mission. The planed trajectory should make sure the quadrotor will scan the whole area without missing any part to make sure that the quadrotor will find the lost

  7. Cooperative path planning of unmanned aerial vehicles

    CERN Document Server

    Tsourdos, Antonios; Shanmugavel, Madhavan

    2010-01-01

    An invaluable addition to the literature on UAV guidance and cooperative control, Cooperative Path Planning of Unmanned Aerial Vehicles is a dedicated, practical guide to computational path planning for UAVs. One of the key issues facing future development of UAVs is path planning: it is vital that swarm UAVs/ MAVs can cooperate together in a coordinated manner, obeying a pre-planned course but able to react to their environment by communicating and cooperating. An optimized path is necessary in order to ensure a UAV completes its mission efficiently, safely, and successfully. Focussing on the path planning of multiple UAVs for simultaneous arrival on target, Cooperative Path Planning of Unmanned Aerial Vehicles also offers coverage of path planners that are applicable to land, sea, or space-borne vehicles. Cooperative Path Planning of Unmanned Aerial Vehicles is authored by leading researchers from Cranfield University and provides an authoritative resource for researchers, academics and engineers working in...

  8. Path planning in changeable environments

    NARCIS (Netherlands)

    Nieuwenhuisen, D.

    2007-01-01

    This thesis addresses path planning in changeable environments. In contrast to traditional path planning that deals with static environments, in changeable environments objects are allowed to change their configurations over time. In many cases, path planning algorithms must facilitate quick

  9. Fractional path planning and path tracking

    International Nuclear Information System (INIS)

    Melchior, P.; Jallouli-Khlif, R.; Metoui, B.

    2011-01-01

    This paper presents the main results of the application of fractional approach in path planning and path tracking. A new robust path planning design for mobile robot was studied in dynamic environment. The normalized attractive force applied to the robot is based on a fictitious fractional attractive potential. This method allows to obtain robust path planning despite robot mass variation. The danger level of each obstacles is characterized by the fractional order of the repulsive potential of the obstacles. Under these conditions, the robot dynamic behavior was studied by analyzing its X - Y path planning with dynamic target or dynamic obstacles. The case of simultaneously mobile obstacles and target is also considered. The influence of the robot mass variation is studied and the robustness analysis of the obtained path shows the robustness improvement due to the non integer order properties. Pre shaping approach is used to reduce system vibration in motion control. Desired systems inputs are altered so that the system finishes the requested move without residual vibration. This technique, developed by N.C. Singer and W.P.Seering, is used for flexible structure control, particularly in the aerospace field. In a previous work, this method was extended for explicit fractional derivative systems and applied to second generation CRONE control, the robustness was also studied. CRONE (the French acronym of C ommande Robuste d'Ordre Non Entier ) control system design is a frequency-domain based methodology using complex fractional integration.

  10. Drug Plan Coverage Rules

    Science.gov (United States)

    ... Glossary MyMedicare.gov Login Search Main Menu , collapsed Main Menu Sign Up / Change Plans Getting started with ... setup: setupNotifier, notify: notify }; lrNotifier.setup(); $("#menu-btn, li.toolbarmenu .toolbarmenu-a").click(function() { // var isExpanded = ' is ...

  11. A Fair Path Toward Universal Coverage: National Case Study for ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    A Fair Path Toward Universal Coverage: National Case Study for Ethiopia, Uganda, and Zambia. As national health systems in developing countries make progress toward achieving universal health service coverage, many face ethical challenges. In its 2010 World Health Report, the World Health Assembly called on the ...

  12. Integrated assignment and path planning

    Science.gov (United States)

    Murphey, Robert A.

    2005-11-01

    A surge of interest in unmanned systems has exposed many new and challenging research problems across many fields of engineering and mathematics. These systems have the potential of transforming our society by replacing dangerous and dirty jobs with networks of moving machines. This vision is fundamentally separate from the modern view of robotics in that sophisticated behavior is realizable not by increasing individual vehicle complexity, but instead through collaborative teaming that relies on collective perception, abstraction, decision making, and manipulation. Obvious examples where collective robotics will make an impact include planetary exploration, space structure assembly, remote and undersea mining, hazardous material handling and clean-up, and search and rescue. Nonetheless, the phenomenon driving this technology trend is the increasing reliance of the US military on unmanned vehicles, specifically, aircraft. Only a few years ago, following years of resistance to the use of unmanned systems, the military and civilian leadership in the United States reversed itself and have recently demonstrated surprisingly broad acceptance of increasingly pervasive use of unmanned platforms in defense surveillance, and even attack. However, as rapidly as unmanned systems have gained acceptance, the defense research community has discovered the technical pitfalls that lie ahead, especially for operating collective groups of unmanned platforms. A great deal of talent and energy has been devoted to solving these technical problems, which tend to fall into two categories: resource allocation of vehicles to objectives, and path planning of vehicle trajectories. An extensive amount of research has been conducted in each direction, yet, surprisingly, very little work has considered the integrated problem of assignment and path planning. This dissertation presents a framework for studying integrated assignment and path planning and then moves on to suggest an exact

  13. Strategic Team AI Path Plans: Probabilistic Pathfinding

    Directory of Open Access Journals (Sweden)

    Tng C. H. John

    2008-01-01

    Full Text Available This paper proposes a novel method to generate strategic team AI pathfinding plans for computer games and simulations using probabilistic pathfinding. This method is inspired by genetic algorithms (Russell and Norvig, 2002, in that, a fitness function is used to test the quality of the path plans. The method generates high-quality path plans by eliminating the low-quality ones. The path plans are generated by probabilistic pathfinding, and the elimination is done by a fitness test of the path plans. This path plan generation method has the ability to generate variation or different high-quality paths, which is desired for games to increase replay values. This work is an extension of our earlier work on team AI: probabilistic pathfinding (John et al., 2006. We explore ways to combine probabilistic pathfinding and genetic algorithm to create a new method to generate strategic team AI pathfinding plans.

  14. Cooperative organic mine avoidance path planning

    Science.gov (United States)

    McCubbin, Christopher B.; Piatko, Christine D.; Peterson, Adam V.; Donnald, Creighton R.; Cohen, David

    2005-06-01

    The JHU/APL Path Planning team has developed path planning techniques to look for paths that balance the utility and risk associated with different routes through a minefield. Extending on previous years' efforts, we investigated real-world Naval mine avoidance requirements and developed a tactical decision aid (TDA) that satisfies those requirements. APL has developed new mine path planning techniques using graph based and genetic algorithms which quickly produce near-minimum risk paths for complicated fitness functions incorporating risk, path length, ship kinematics, and naval doctrine. The TDA user interface, a Java Swing application that obtains data via Corba interfaces to path planning databases, allows the operator to explore a fusion of historic and in situ mine field data, control the path planner, and display the planning results. To provide a context for the minefield data, the user interface also renders data from the Digital Nautical Chart database, a database created by the National Geospatial-Intelligence Agency containing charts of the world's ports and coastal regions. This TDA has been developed in conjunction with the COMID (Cooperative Organic Mine Defense) system. This paper presents a description of the algorithms, architecture, and application produced.

  15. Feasible Path Planning for Autonomous Vehicles

    Directory of Open Access Journals (Sweden)

    Vu Trieu Minh

    2014-01-01

    Full Text Available The objective of this paper is to find feasible path planning algorithms for nonholonomic vehicles including flatness, polynomial, and symmetric polynomial trajectories subject to the real vehicle dynamical constraints. Performances of these path planning methods are simulated and compared to evaluate the more realistic and smoother generated trajectories. Results show that the symmetric polynomial algorithm provides the smoothest trajectory. Therefore, this algorithm is recommended for the development of an automatic control for autonomous vehicles.

  16. Path to a Research Plan

    Science.gov (United States)

    Chiaramonte, Fran

    2003-01-01

    This viewgraph presentation discusses the status and goals for the NASA OBPR Physical Science Research Program. The following text was used to summarize the presentation. The OBPR Physical Sciences Research program has been comprehensively reviewed and endorsed by National Research Council. The value and need for the research have been re-affirmed. The research program has been prioritized and resource re-allocations have been carried out through an OBPR-wide process. An increasing emphasis on strategic, mission-oriented research is planned. The program will strive to maintain a balance between strategic and fundamental research. A feasible ISS flight research program fitting within the budgetary and ISS resource envelopes has been formulated for the near term (2003-2007). The current ISS research program will be significantly strengthened starting 2005 by using discipline dedicated research facility racks. A research re-planning effort has been initiated and will include active participation from the research community in the next few months. The research re-planning effort will poise PSR to increase ISS research utilization for a potential enhancement beyond ISS IP Core Complete. The Physical Sciences research program readily integrates the cross-disciplinary requirements of the NASA and OBPR strategic objectives. Each fundamental research thrust will develop a roadmap through technical workshops and Discipline Working Groups (DWGs). Most fundamental research thrusts will involve cross-disciplinary efforts. A Technology Roadmap will guide the Strategic Research for Exploration thrust. The Research Plan will integrate and coordinate fundamental Research Thrusts Roadmaps with the Technology Roadmap. The Technology Roadmap will be developed in coordination with other OBPR programs as well as other Enterprise (R,S,M,N). International Partners will contribute to the roadmaps and through research coordination. The research plan will be vetted with the discipline

  17. Learning to improve path planning performance

    International Nuclear Information System (INIS)

    Chen, Pang C.

    1995-04-01

    In robotics, path planning refers to finding a short. collision-free path from an initial robot configuration to a desired configuratioin. It has to be fast to support real-time task-level robot programming. Unfortunately, current planning techniques are still too slow to be effective, as they often require several minutes, if not hours of computation. To remedy this situation, we present and analyze a learning algorithm that uses past experience to increase future performance. The algorithm relies on an existing path planner to provide solutions to difficult tasks. From these solutions, an evolving sparse network of useful robot configurations is learned to support faster planning. More generally, the algorithm provides a speedup-learning framework in which a slow but capable planner may be improved both cost-wise and capability-wise by a faster but less capable planner coupled with experience. The basic algorithm is suitable for stationary environments, and can be extended to accommodate changing environments with on-demand experience repair and object-attached experience abstraction. To analyze the algorithm, we characterize the situations in which the adaptive planner is useful, provide quantitative bounds to predict its behavior, and confirm our theoretical results with experiments in path planning of manipulators. Our algorithm and analysis are sufficiently, general that they may also be applied to other planning domains in which experience is useful

  18. Flexible integration of path-planning capabilities

    Science.gov (United States)

    Stobie, Iain C.; Tambe, Milind; Rosenbloom, Paul S.

    1993-05-01

    Robots pursuing complex goals must plan paths according to several criteria of quality, including shortness, safety, speed and planning time. Many sources and kinds of knowledge, such as maps, procedures and perception, may be available or required. Both the quality criteria and sources of knowledge may vary widely over time, and in general they will interact. One approach to address this problem is to express all criteria and goals numerically in a single weighted graph, and then to search this graph to determine a path. Since this is problematic with symbolic or uncertain data and interacting criteria, we propose that what is needed instead is an integration of many kinds of planning capabilities. We describe a hybrid approach to integration, based on experiments with building simulated mobile robots using Soar, an integrated problem-solving and learning system. For flexibility, we have implemented a combination of internal planning, reactive capabilities and specialized tools. We illustrate how these components can complement each other's limitations and produce plans which integrate geometric and task knowledge.

  19. Walking path-planning method for multiple radiation areas

    International Nuclear Information System (INIS)

    Liu, Yong-kuo; Li, Meng-kun; Peng, Min-jun; Xie, Chun-li; Yuan, Cheng-qian; Wang, Shuang-yu; Chao, Nan

    2016-01-01

    Highlights: • Radiation environment modeling method is designed. • Path-evaluating method and segmented path-planning method are proposed. • Path-planning simulation platform for radiation environment is built. • The method avoids to be misled by minimum dose path in single area. - Abstract: Based on minimum dose path-searching method, walking path-planning method for multiple radiation areas was designed to solve minimum dose path problem in single area and find minimum dose path in the whole space in this paper. Path-planning simulation platform was built using C# programming language and DirectX engine. The simulation platform was used in simulations dealing with virtual nuclear facilities. Simulation results indicated that the walking-path planning method is effective in providing safety for people walking in nuclear facilities.

  20. Path planning algorithms for assembly sequence planning. [in robot kinematics

    Science.gov (United States)

    Krishnan, S. S.; Sanderson, Arthur C.

    1991-01-01

    Planning for manipulation in complex environments often requires reasoning about the geometric and mechanical constraints which are posed by the task. In planning assembly operations, the automatic generation of operations sequences depends on the geometric feasibility of paths which permit parts to be joined into subassemblies. Feasible locations and collision-free paths must be present for part motions, robot and grasping motions, and fixtures. This paper describes an approach to reasoning about the feasibility of straight-line paths among three-dimensional polyhedral parts using an algebra of polyhedral cones. A second method recasts the feasibility conditions as constraints in a nonlinear optimization framework. Both algorithms have been implemented and results are presented.

  1. Robotic Online Path Planning on Point Cloud.

    Science.gov (United States)

    Liu, Ming

    2016-05-01

    This paper deals with the path-planning problem for mobile wheeled- or tracked-robot which drive in 2.5-D environments, where the traversable surface is usually considered as a 2-D-manifold embedded in a 3-D ambient space. Specially, we aim at solving the 2.5-D navigation problem using raw point cloud as input. The proposed method is independent of traditional surface parametrization or reconstruction methods, such as a meshing process, which generally has high-computational complexity. Instead, we utilize the output of 3-D tensor voting framework on the raw point clouds. The computation of tensor voting is accelerated by optimized implementation on graphics computation unit. Based on the tensor voting results, a novel local Riemannian metric is defined using the saliency components, which helps the modeling of the latent traversable surface. Using the proposed metric, we prove that the geodesic in the 3-D tensor space leads to rational path-planning results by experiments. Compared to traditional methods, the results reveal the advantages of the proposed method in terms of smoothing the robot maneuver while considering the minimum travel distance.

  2. Physics-Aware Informative Coverage Planning for Autonomous Vehicles

    Science.gov (United States)

    2014-06-01

    Physics-Aware Informative Coverage Planning for Autonomous Vehicles Michael J. Kuhlman1, Student Member, IEEE, Petr Švec2, Member, IEEE, Krishnanand...Physics-Aware Informative Coverage Planning for Autonomous Vehicles 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d

  3. Static and Dynamic Path Planning Using Incremental Heuristic Search

    OpenAIRE

    Khattab, Asem

    2018-01-01

    Path planning is an important component in any highly automated vehicle system. In this report, the general problem of path planning is considered first in partially known static environments where only static obstacles are present but the layout of the environment is changing as the agent acquires new information. Attention is then given to the problem of path planning in dynamic environments where there are moving obstacles in addition to the static ones. Specifically, a 2D car-like agent t...

  4. Ethical Perspective: Five Unacceptable Trade-offs on the Path to Universal Health Coverage

    Directory of Open Access Journals (Sweden)

    Ole Frithjof Norheim

    2015-11-01

    Full Text Available This article discusses what ethicists have called “unacceptable trade-offs” in health policy choices related to universal health coverage (UHC. Since the fiscal space is constrained, trade-offs need to be made. But some trade-offs are unacceptable on the path to universal coverage. Unacceptable choices include, among other examples from low-income countries, to expand coverage for services with lower priority such as coronary bypass surgery before securing universal coverage for high-priority services such as skilled birth attendance and services for easily preventable or treatable fatal childhood diseases. Services of the latter kind include oral rehydration therapy for children with diarrhea and antibiotics for children with pneumonia. The article explains why such trade-offs are unfair and unacceptable even if political considerations may push in the opposite direction.

  5. 24 CFR 203.205 - Plan coverage.

    Science.gov (United States)

    2010-04-01

    ... damaged during installation or improperly installed by the builder. The plan must also cover structural... warranty against defects in the wiring, piping and ductwork in the electrical, plumbing, heating, cooling...

  6. A New Method of Global Path Planning for AGV

    Institute of Scientific and Technical Information of China (English)

    SHI En-xiu; HUANG Yu-mei

    2006-01-01

    Path planning is important in the research of a mobile robot (MR). Methods for it have been used in different applications. An automated guided vehicle(AGV), which is a kind of MR, is used in a flexible manufacturing system(FMS). Path planning for it is essential to improve the efficiency of FMS. A new method was proposed with known obstacle space FMS in this paper. FMS is described by the Augmented Pos Matrix of a Machine (APMM) and Relative Pos Matrix of Machines (RPMM), which is smaller. The optimum path can be obtained according to the probability of the path and the maximal probability path. The suggested algorithm of path planning was good performance through simulation result: simplicity, saving time and reliability.

  7. Analysis of construction dynamic plan using fuzzy critical path method

    Directory of Open Access Journals (Sweden)

    Kurij Kazimir V.

    2014-01-01

    Full Text Available Critical Path Method (CPM technique has become widely recognized as valuable tool for the planning and scheduling large construction projects. The aim of this paper is to present an analytical method for finding the Critical Path in the precedence network diagram where the duration of each activity is represented by a trapezoidal fuzzy number. This Fuzzy Critical Path Method (FCPM uses a defuzzification formula for trapezoidal fuzzy number and applies it on the total float (slack time for each activity in the fuzzy precedence network to find the critical path. The method presented in this paper is very effective in determining the critical activities and finding the critical paths.

  8. Multi-AGV path planning with double-path constraints by using an improved genetic algorithm.

    Directory of Open Access Journals (Sweden)

    Zengliang Han

    Full Text Available This paper investigates an improved genetic algorithm on multiple automated guided vehicle (multi-AGV path planning. The innovations embody in two aspects. First, three-exchange crossover heuristic operators are used to produce more optimal offsprings for getting more information than with the traditional two-exchange crossover heuristic operators in the improved genetic algorithm. Second, double-path constraints of both minimizing the total path distance of all AGVs and minimizing single path distances of each AGV are exerted, gaining the optimal shortest total path distance. The simulation results show that the total path distance of all AGVs and the longest single AGV path distance are shortened by using the improved genetic algorithm.

  9. The force control and path planning of electromagnetic induction-based massage robot.

    Science.gov (United States)

    Wang, Wendong; Zhang, Lei; Li, Jinzhe; Yuan, Xiaoqing; Shi, Yikai; Jiang, Qinqin; He, Lijing

    2017-07-20

    Massage robot is considered as an effective physiological treatment to relieve fatigue, improve blood circulation, relax muscle tone, etc. The simple massage equipment quickly spread into market due to low cost, but they are not widely accepted due to restricted massage function. Complicated structure and high cost caused difficulties for developing multi-function massage equipment. This paper presents a novel massage robot which can achieve tapping, rolling, kneading and other massage operations, and proposes an improved reciprocating path planning algorithm to improve massage effect. The number of coil turns, the coil current and the distance between massage head and yoke were chosen to investigate the influence on massage force by finite element method. The control system model of the wheeled massage robot was established, including control subsystem of the motor, path algorithm control subsystem, parameter module of the massage robot and virtual reality interface module. The improved reciprocating path planning algorithm was proposed to improve regional coverage rate and massage effect. The influence caused by coil current, the number of coil turns and the distance between massage head and yoke were simulated in Maxwell. It indicated that coil current has more important influence compared to the other two factors. The path planning simulation of the massage robot was completed in Matlab, and the results show that the improved reciprocating path planning algorithm achieved higher coverage rate than the traditional algorithm. With the analysis of simulation results, it can be concluded that the number of coil turns and the distance between the moving iron core and the yoke could be determined prior to coil current, and the force can be controllable by optimizing structure parameters of massage head and adjusting coil current. Meanwhile, it demonstrates that the proposed algorithm could effectively improve path coverage rate during massage operations, therefore

  10. A Hybrid 3D Path Planning Method for UAVs

    DEFF Research Database (Denmark)

    Ortiz-Arroyo, Daniel

    2015-01-01

    This paper presents a hybrid method for path planning in 3D spaces. We propose an improvement to a near-optimal 2D off-line algorithm and a flexible normalized on-line fuzzy controller to find shortest paths. Our method, targeted to low altitude domains, is simple and efficient. Our preliminary resu...

  11. Reactive Path Planning Approach for Docking Robots in Unknown Environment

    Directory of Open Access Journals (Sweden)

    Peng Cui

    2017-01-01

    Full Text Available Autonomous robots need to be recharged and exchange information with the host through docking in the long-distance tasks. Therefore, feasible path is required in the docking process to guide the robot and adjust its pose. However, when there are unknown obstacles in the work area, it becomes difficult to determine the feasible path for docking. This paper presents a reactive path planning approach named Dubins-APF (DAPF to solve the path planning problem for docking in unknown environment with obstacles. In this proposed approach the Dubins curves are combined with the designed obstacle avoidance potential field to plan the feasible path. Firstly, an initial path is planned and followed according to the configurations of the robot and the docking station. Then when the followed path is evaluated to be infeasible, the intermediate configuration is calculated as well as the replanned path based on the obstacle avoidance potential field. The robot will be navigated to the docking station with proper pose eventually via the DAPF approach. The proposed DAPF approach is efficient and does not require the prior knowledge about the environment. Simulation results are given to validate the effectiveness and feasibility of the proposed approach.

  12. Path Planning with a Lazy Significant Edge Algorithm (LSEA

    Directory of Open Access Journals (Sweden)

    Joseph Polden

    2013-04-01

    Full Text Available Probabilistic methods have been proven to be effective for robotic path planning in a geometrically complex environment. In this paper, we propose a novel approach, which utilizes a specialized roadmap expansion phase, to improve lazy probabilistic path planning. This expansion phase analyses roadmap connectivity information to bias sampling towards objects in the workspace that have not yet been navigated by the robot. A new method to reduce the number of samples required to navigate narrow passages is also proposed and tested. Experimental results show that the new algorithm is more efficient than the traditional path planning methodologies. It was able to generate solutions for a variety of path planning problems faster, using fewer samples to arrive at a valid solution.

  13. Active Path Planning for Drones in Object Search

    OpenAIRE

    Wang, Zeyangyi

    2017-01-01

    Object searching is one of the most popular applications of unmanned aerial vehicles. Low cost small drones are particularly suited for surveying tasks in difficult conditions. With their limited on-board processing power and battery life, there is a need for more efficient search algorithm. The proposed path planning algorithm utilizes AZ-net, a deep learning network to process images captured on drones for adaptive flight path planning. Search simulation based on videos and actual experimen...

  14. Path Planning Method in Multi-obstacle Marine Environment

    Science.gov (United States)

    Zhang, Jinpeng; Sun, Hanxv

    2017-12-01

    In this paper, an improved algorithm for particle swarm optimization is proposed for the application of underwater robot in the complex marine environment. Not only did consider to avoid obstacles when path planning, but also considered the current direction and the size effect on the performance of the robot dynamics. The algorithm uses the trunk binary tree structure to construct the path search space and A * heuristic search method is used in the search space to find a evaluation standard path. Then the particle swarm algorithm to optimize the path by adjusting evaluation function, which makes the underwater robot in the current navigation easier to control, and consume less energy.

  15. Path Planning Methods in an Environment with Obstacles (A Review

    Directory of Open Access Journals (Sweden)

    W. Liu

    2018-01-01

    Full Text Available Planning the path is the most important task in the mobile robot navigation. This task involves basically three aspects. First, the planned path must run from a given starting point to a given endpoint. Secondly, it should ensure robot’s collision-free movement. Thirdly, among all the possible paths that meet the first two requirements it must be, in a certain sense, optimal.Methods of path planning can be classified according to different characteristics. In the context of using intelligent technologies, they can be divided into traditional methods and heuristic ones. By the nature of the environment, it is possible to divide planning methods into planning methods in a static environment and in a dynamic one (it should be noted, however, that a static environment is rare. Methods can also be divided according to the completeness of information about the environment, namely methods with complete information (in this case the issue is a global path planning and methods with incomplete information (usually, this refers to the situational awareness in the immediate vicinity of the robot, in this case it is a local path planning. Note that incomplete information about the environment can be a consequence of the changing environment, i.e. in a dynamic environment, there is, usually, a local path planning.Literature offers a great deal of methods for path planning where various heuristic techniques are used, which, as a rule, result from the denotative meaning of the problem being solved. This review discusses the main approaches to the problem solution. Here we can distinguish five classes of basic methods: graph-based methods, methods based on cell decomposition, use of potential fields, optimization methods, фтв methods based on intelligent technologies.Many methods of path planning, as a result, give a chain of reference points (waypoints connecting the beginning and end of the path. This should be seen as an intermediate result. The problem

  16. Points-Based Safe Path Planning of Continuum Robots

    Directory of Open Access Journals (Sweden)

    Khuram Shahzad

    2015-07-01

    Full Text Available Continuum robots exhibit great potential in a number of challenging applications where traditional rigid link robots pose certain limitations, e.g., working in unstructured environments. In order to enable the usage of continuum robots in safety-critical applications, such as surgery and nuclear decontamination, it is extremely important to ensure a safe path for the robot's movement. Existing algorithms for continuum robot path planning have certain limitations that need to be addressed. These include the fact that none of the algorithms provide safety assurance parameters and control for path planning. They are computationally expensive, applicable to a specific type of continuum robots, and mostly they do not incorporate design and kinematics constraints. In this paper, we propose a points-based path planning (PoPP algorithm for continuum robots that computes the path by imposing safety constraints and improves upon the limitations of existing approaches. In the algorithm, we exploit the constant curvature-bending property of continuum robots in their path planning process. The algorithm is computationally efficient and provides a good tradeoff between accuracy and efficiency that can be implemented to enable the safety-critical application of continuum robots. This algorithm also provides information regarding path volume and flexibility in movement. Simulation results confirm that the algorithm possesses promising potential for all types of continuum robots (following the constant curvature-bending property. We believe that this effectively balances the desired safety and efficiency requirements.

  17. The Unplanned Paths of Planning Schools.

    Science.gov (United States)

    Alonso, William

    1986-01-01

    Describes the evolving emphasis of schools of urban planning from concentration on scientific management, beautifying cities, and educating the public in the 1920s to solving the social problems in the 1960s. Calls for a collaboration of business and other professional schools to redefine the function and purpose of urban planning schools to…

  18. Universal Health Coverage - The Critical Importance of Global Solidarity and Good Governance Comment on "Ethical Perspective: Five Unacceptable Trade-offs on the Path to Universal Health Coverage".

    Science.gov (United States)

    Reis, Andreas A

    2016-06-07

    This article provides a commentary to Ole Norheim' s editorial entitled "Ethical perspective: Five unacceptable trade-offs on the path to universal health coverage." It reinforces its message that an inclusive, participatory process is essential for ethical decision-making and underlines the crucial importance of good governance in setting fair priorities in healthcare. Solidarity on both national and international levels is needed to make progress towards the goal of universal health coverage (UHC). © 2016 by Kerman University of Medical Sciences.

  19. Robust Path Planning for Space Exploration Rovers

    Data.gov (United States)

    National Aeronautics and Space Administration — Motion planning considers the problem of moving a system from a starting position to a desired goal position. This problem has been shown to be a computationally...

  20. Rapidly Exploring Random Trees Used for Mobile Robots Path Planning

    Czech Academy of Sciences Publication Activity Database

    Krejsa, Jiří; Věchet, S.

    2005-01-01

    Roč. 12, č. 4 (2005), s. 231-238 ISSN 1802-1484. [Mechatronics, Robotics and Biomechanics 2005. Třešť, 26.09.2005-29.09.2005] Institutional research plan: CEZ:AV0Z20760514 Keywords : path planning * mobile robot Subject RIV: JD - Computer Applications, Robotics

  1. The path towards universal health coverage in the Arab uprising countries Tunisia, Egypt, Libya, and Yemen.

    Science.gov (United States)

    Saleh, Shadi S; Alameddine, Mohamad S; Natafgi, Nabil M; Mataria, Awad; Sabri, Belgacem; Nasher, Jamal; Zeiton, Moez; Ahmad, Shaimaa; Siddiqi, Sameen

    2014-01-25

    The constitutions of many countries in the Arab world clearly highlight the role of governments in guaranteeing provision of health care as a right for all citizens. However, citizens still have inequitable health-care systems. One component of such inequity relates to restricted financial access to health-care services. The recent uprisings in the Arab world, commonly referred to as the Arab spring, created a sociopolitical momentum that should be used to achieve universal health coverage (UHC). At present, many countries of the Arab spring are considering health coverage as a priority in dialogues for new constitutions and national policy agendas. UHC is also the focus of advocacy campaigns of a number of non-governmental organisations and media outlets. As part of the health in the Arab world Series in The Lancet, this report has three overarching objectives. First, we present selected experiences of other countries that had similar social and political changes, and how these events affected their path towards UHC. Second, we present a brief overview of the development of health-care systems in the Arab world with regard to health-care coverage and financing, with a focus on Egypt, Libya, Tunisia, and Yemen. Third, we aim to integrate historical lessons with present contexts in a roadmap for action that addresses the challenges and opportunities for progression towards UHC. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Aircraft path planning for optimal imaging using dynamic cost functions

    Science.gov (United States)

    Christie, Gordon; Chaudhry, Haseeb; Kochersberger, Kevin

    2015-05-01

    Unmanned aircraft development has accelerated with recent technological improvements in sensing and communications, which has resulted in an "applications lag" for how these aircraft can best be utilized. The aircraft are becoming smaller, more maneuverable and have longer endurance to perform sensing and sampling missions, but operating them aggressively to exploit these capabilities has not been a primary focus in unmanned systems development. This paper addresses a means of aerial vehicle path planning to provide a realistic optimal path in acquiring imagery for structure from motion (SfM) reconstructions and performing radiation surveys. This method will allow SfM reconstructions to occur accurately and with minimal flight time so that the reconstructions can be executed efficiently. An assumption is made that we have 3D point cloud data available prior to the flight. A discrete set of scan lines are proposed for the given area that are scored based on visibility of the scene. Our approach finds a time-efficient path and calculates trajectories between scan lines and over obstacles encountered along those scan lines. Aircraft dynamics are incorporated into the path planning algorithm as dynamic cost functions to create optimal imaging paths in minimum time. Simulations of the path planning algorithm are shown for an urban environment. We also present our approach for image-based terrain mapping, which is able to efficiently perform a 3D reconstruction of a large area without the use of GPS data.

  3. Path Planning Algorithms for Autonomous Border Patrol Vehicles

    Science.gov (United States)

    Lau, George Tin Lam

    This thesis presents an online path planning algorithm developed for unmanned vehicles in charge of autonomous border patrol. In this Pursuit-Evasion game, the unmanned vehicle is required to capture multiple trespassers on its own before any of them reach a target safe house where they are safe from capture. The problem formulation is based on Isaacs' Target Guarding problem, but extended to the case of multiple evaders. The proposed path planning method is based on Rapidly-exploring random trees (RRT) and is capable of producing trajectories within several seconds to capture 2 or 3 evaders. Simulations are carried out to demonstrate that the resulting trajectories approach the optimal solution produced by a nonlinear programming-based numerical optimal control solver. Experiments are also conducted on unmanned ground vehicles to show the feasibility of implementing the proposed online path planning algorithm on physical applications.

  4. Survey of Robot 3D Path Planning Algorithms

    Directory of Open Access Journals (Sweden)

    Liang Yang

    2016-01-01

    Full Text Available Robot 3D (three-dimension path planning targets for finding an optimal and collision-free path in a 3D workspace while taking into account kinematic constraints (including geometric, physical, and temporal constraints. The purpose of path planning, unlike motion planning which must be taken into consideration of dynamics, is to find a kinematically optimal path with the least time as well as model the environment completely. We discuss the fundamentals of these most successful robot 3D path planning algorithms which have been developed in recent years and concentrate on universally applicable algorithms which can be implemented in aerial robots, ground robots, and underwater robots. This paper classifies all the methods into five categories based on their exploring mechanisms and proposes a category, called multifusion based algorithms. For all these algorithms, they are analyzed from a time efficiency and implementable area perspective. Furthermore a comprehensive applicable analysis for each kind of method is presented after considering their merits and weaknesses.

  5. A bat algorithm with mutation for UCAV path planning.

    Science.gov (United States)

    Wang, Gaige; Guo, Lihong; Duan, Hong; Liu, Luo; Wang, Heqi

    2012-01-01

    Path planning for uninhabited combat air vehicle (UCAV) is a complicated high dimension optimization problem, which mainly centralizes on optimizing the flight route considering the different kinds of constrains under complicated battle field environments. Original bat algorithm (BA) is used to solve the UCAV path planning problem. Furthermore, a new bat algorithm with mutation (BAM) is proposed to solve the UCAV path planning problem, and a modification is applied to mutate between bats during the process of the new solutions updating. Then, the UCAV can find the safe path by connecting the chosen nodes of the coordinates while avoiding the threat areas and costing minimum fuel. This new approach can accelerate the global convergence speed while preserving the strong robustness of the basic BA. The realization procedure for original BA and this improved metaheuristic approach BAM is also presented. To prove the performance of this proposed metaheuristic method, BAM is compared with BA and other population-based optimization methods, such as ACO, BBO, DE, ES, GA, PBIL, PSO, and SGA. The experiment shows that the proposed approach is more effective and feasible in UCAV path planning than the other models.

  6. Mission-directed path planning for planetary rover exploration

    Science.gov (United States)

    Tompkins, Paul

    2005-07-01

    Robotic rovers uniquely benefit planetary exploration---they enable regional exploration with the precision of in-situ measurements, a combination impossible from an orbiting spacecraft or fixed lander. Mission planning for planetary rover exploration currently utilizes sophisticated software for activity planning and scheduling, but simplified path planning and execution approaches tailored for localized operations to individual targets. This approach is insufficient for the investigation of multiple, regionally distributed targets in a single command cycle. Path planning tailored for this task must consider the impact of large scale terrain on power, speed and regional access; the effect of route timing on resource availability; the limitations of finite resource capacity and other operational constraints on vehicle range and timing; and the mutual influence between traverses and upstream and downstream stationary activities. Encapsulating this reasoning in an efficient autonomous planner would allow a rover to continue operating rationally despite significant deviations from an initial plan. This research presents mission-directed path planning that enables an autonomous, strategic reasoning capability for robotic explorers. Planning operates in a space of position, time and energy. Unlike previous hierarchical approaches, it treats these dimensions simultaneously to enable globally-optimal solutions. The approach calls on a near incremental search algorithm designed for planning and re-planning under global constraints, in spaces of higher than two dimensions. Solutions under this method specify routes that avoid terrain obstacles, optimize the collection and use of rechargable energy, satisfy local and global mission constraints, and account for the time and energy of interleaved mission activities. Furthermore, the approach efficiently re-plans in response to updates in vehicle state and world models, and is well suited to online operation aboard a robot

  7. Safe Maritime Autonomous Path Planning in a High Sea State

    Science.gov (United States)

    Ono, Masahiro; Quadrelli, Marco; Huntsberger, Terrance L.

    2014-01-01

    This paper presents a path planning method for sea surface vehicles that prevents capsizing and bow-diving in a high sea-state. A key idea is to use response amplitude operators (RAOs) or, in control terminology, the transfer functions from a sea state to a vessel's motion, in order to find a set of speeds and headings that results in excessive pitch and roll oscillations. This information is translated to arithmetic constraints on the ship's velocity, which are passed to a model predictive control (MPC)-based path planner to find a safe and optimal path that achieves specified goals. An obstacle avoidance capability is also added to the path planner. The proposed method is demonstrated by simulations.

  8. Path Planning & Measurement Registration for Robotic Structural Asset Monitoring

    OpenAIRE

    Pierce , Stephen Gareth; Macleod , Charles Norman; Dobie , Gordon; Summan , Rahul

    2014-01-01

    International audience; The move to increased levels of autonomy for robotic delivery of inspection for asset monitoring, demands a structured approach to path planning and measurement data presentation that greatly surpasses the more ad‐,hoc approach typically employed by remotely controlled, but manually driven robotic inspection vehicles. The authors describe a traditional CAD/CAM approach to motion planning (as used in machine tool operation) which has numerous benefits including the...

  9. Aircraft path planning with the use of smooth trajectories

    Science.gov (United States)

    Belokon', S. A.; Zolotukhin, Yu. N.; Nesterov, A. A.

    2017-01-01

    A simplified method of plane trajectory calculation is proposed for solving the problem of planning a path defined by a sequence of waypoints. The trajectory consists of oriented segments of straight lines joined by clothoids (Cornu spirals). The efficiency of the method is validated by means of numerical simulations in the MATLAB/Simulink environment.

  10. Robust Path Planning and Feedback Design Under Stochastic Uncertainty

    Science.gov (United States)

    Blackmore, Lars

    2008-01-01

    Autonomous vehicles require optimal path planning algorithms to achieve mission goals while avoiding obstacles and being robust to uncertainties. The uncertainties arise from exogenous disturbances, modeling errors, and sensor noise, which can be characterized via stochastic models. Previous work defined a notion of robustness in a stochastic setting by using the concept of chance constraints. This requires that mission constraint violation can occur with a probability less than a prescribed value.In this paper we describe a novel method for optimal chance constrained path planning with feedback design. The approach optimizes both the reference trajectory to be followed and the feedback controller used to reject uncertainty. Our method extends recent results in constrained control synthesis based on convex optimization to solve control problems with nonconvex constraints. This extension is essential for path planning problems, which inherently have nonconvex obstacle avoidance constraints. Unlike previous approaches to chance constrained path planning, the new approach optimizes the feedback gain as wellas the reference trajectory.The key idea is to couple a fast, nonconvex solver that does not take into account uncertainty, with existing robust approaches that apply only to convex feasible regions. By alternating between robust and nonrobust solutions, the new algorithm guarantees convergence to a global optimum. We apply the new method to an unmanned aircraft and show simulation results that demonstrate the efficacy of the approach.

  11. 76 FR 46677 - Requirements for Group Health Plans and Health Insurance Issuers Relating to Coverage of...

    Science.gov (United States)

    2011-08-03

    ... Requirements for Group Health Plans and Health Insurance Issuers Relating to Coverage of Preventive Services... regulations published July 19, 2010 with respect to group health plans and health insurance coverage offered... plans, and health insurance issuers providing group health insurance coverage. The text of those...

  12. Image-based path planning for automated virtual colonoscopy navigation

    Science.gov (United States)

    Hong, Wei

    2008-03-01

    Virtual colonoscopy (VC) is a noninvasive method for colonic polyp screening, by reconstructing three-dimensional models of the colon using computerized tomography (CT). In virtual colonoscopy fly-through navigation, it is crucial to generate an optimal camera path for efficient clinical examination. In conventional methods, the centerline of the colon lumen is usually used as the camera path. In order to extract colon centerline, some time consuming pre-processing algorithms must be performed before the fly-through navigation, such as colon segmentation, distance transformation, or topological thinning. In this paper, we present an efficient image-based path planning algorithm for automated virtual colonoscopy fly-through navigation without the requirement of any pre-processing. Our algorithm only needs the physician to provide a seed point as the starting camera position using 2D axial CT images. A wide angle fisheye camera model is used to generate a depth image from the current camera position. Two types of navigational landmarks, safe regions and target regions are extracted from the depth images. Camera position and its corresponding view direction are then determined using these landmarks. The experimental results show that the generated paths are accurate and increase the user comfort during the fly-through navigation. Moreover, because of the efficiency of our path planning algorithm and rendering algorithm, our VC fly-through navigation system can still guarantee 30 FPS.

  13. Path Planning Algorithms for the Adaptive Sensor Fleet

    Science.gov (United States)

    Stoneking, Eric; Hosler, Jeff

    2005-01-01

    The Adaptive Sensor Fleet (ASF) is a general purpose fleet management and planning system being developed by NASA in coordination with NOAA. The current mission of ASF is to provide the capability for autonomous cooperative survey and sampling of dynamic oceanographic phenomena such as current systems and algae blooms. Each ASF vessel is a software model that represents a real world platform that carries a variety of sensors. The OASIS platform will provide the first physical vessel, outfitted with the systems and payloads necessary to execute the oceanographic observations described in this paper. The ASF architecture is being designed for extensibility to accommodate heterogenous fleet elements, and is not limited to using the OASIS platform to acquire data. This paper describes the path planning algorithms developed for the acquisition phase of a typical ASF task. Given a polygonal target region to be surveyed, the region is subdivided according to the number of vessels in the fleet. The subdivision algorithm seeks a solution in which all subregions have equal area and minimum mean radius. Once the subregions are defined, a dynamic programming method is used to find a minimum-time path for each vessel from its initial position to its assigned region. This path plan includes the effects of water currents as well as avoidance of known obstacles. A fleet-level planning algorithm then shuffles the individual vessel assignments to find the overall solution which puts all vessels in their assigned regions in the minimum time. This shuffle algorithm may be described as a process of elimination on the sorted list of permutations of a cost matrix. All these path planning algorithms are facilitated by discretizing the region of interest onto a hexagonal tiling.

  14. Globally Optimal Path Planning with Anisotropic Running Costs

    Science.gov (United States)

    2013-03-01

    Eikonal equation and has numerous applications, for exam- ple, in path planning, computational geometry, computer vision, and image enhancement...Sethian 1999b]. Numerical methods for solving the Eikonal equation include Tsitsiklis’ control-theoretic algorithm [Tsitsiklis 1995], Fast Marching Methods...methods for Eikonal equations on triangular meshes, SIAM J. Numer. Anal. 45(1), 83—107. Rowe, M. P., Sidhu, H. S. & Mercer, G. N. (2009) Military

  15. Cooperative Path-Planning for Multi-Vehicle Systems

    Directory of Open Access Journals (Sweden)

    Qichen Wang

    2014-11-01

    Full Text Available In this paper, we propose a collision avoidance algorithm for multi-vehicle systems, which is a common problem in many areas, including navigation and robotics. In dynamic environments, vehicles may become involved in potential collisions with each other, particularly when the vehicle density is high and the direction of travel is unrestricted. Cooperatively planning vehicle movement can effectively reduce and fairly distribute the detour inconvenience before subsequently returning vehicles to their intended paths. We present a novel method of cooperative path planning for multi-vehicle systems based on reinforcement learning to address this problem as a decision process. A dynamic system is described as a multi-dimensional space formed by vectors as states to represent all participating vehicles’ position and orientation, whilst considering the kinematic constraints of the vehicles. Actions are defined for the system to transit from one state to another. In order to select appropriate actions whilst satisfying the constraints of path smoothness, constant speed and complying with a minimum distance between vehicles, an approximate value function is iteratively developed to indicate the desirability of every state-action pair from the continuous state space and action space. The proposed scheme comprises two phases. The convergence of the value function takes place in the former learning phase, and it is then used as a path planning guideline in the subsequent action phase. This paper summarizes the concept and methodologies used to implement this online cooperative collision avoidance algorithm and presents results and analysis regarding how this cooperative scheme improves upon two baseline schemes where vehicles make movement decisions independently.

  16. Shore-based Path Planning for Marine Vehicles Using a Model of Ocean Currents

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop path planning methods that incorporate an approximate model of ocean currents in path planning for a range of autonomous marine vehicles such as surface...

  17. Path planning in uncertain flow fields using ensemble method

    KAUST Repository

    Wang, Tong

    2016-08-20

    An ensemble-based approach is developed to conduct optimal path planning in unsteady ocean currents under uncertainty. We focus our attention on two-dimensional steady and unsteady uncertain flows, and adopt a sampling methodology that is well suited to operational forecasts, where an ensemble of deterministic predictions is used to model and quantify uncertainty. In an operational setting, much about dynamics, topography, and forcing of the ocean environment is uncertain. To address this uncertainty, the flow field is parametrized using a finite number of independent canonical random variables with known densities, and the ensemble is generated by sampling these variables. For each of the resulting realizations of the uncertain current field, we predict the path that minimizes the travel time by solving a boundary value problem (BVP), based on the Pontryagin maximum principle. A family of backward-in-time trajectories starting at the end position is used to generate suitable initial values for the BVP solver. This allows us to examine and analyze the performance of the sampling strategy and to develop insight into extensions dealing with general circulation ocean models. In particular, the ensemble method enables us to perform a statistical analysis of travel times and consequently develop a path planning approach that accounts for these statistics. The proposed methodology is tested for a number of scenarios. We first validate our algorithms by reproducing simple canonical solutions, and then demonstrate our approach in more complex flow fields, including idealized, steady and unsteady double-gyre flows.

  18. Robot path planning using expert systems and machine vision

    Science.gov (United States)

    Malone, Denis E.; Friedrich, Werner E.

    1992-02-01

    This paper describes a system developed for the robotic processing of naturally variable products. In order to plan the robot motion path it was necessary to use a sensor system, in this case a machine vision system, to observe the variations occurring in workpieces and interpret this with a knowledge based expert system. The knowledge base was acquired by carrying out an in-depth study of the product using examination procedures not available in the robotic workplace and relates the nature of the required path to the information obtainable from the machine vision system. The practical application of this system to the processing of fish fillets is described and used to illustrate the techniques.

  19. An Improved Ant Colony Algorithm for Solving the Path Planning Problem of the Omnidirectional Mobile Vehicle

    Directory of Open Access Journals (Sweden)

    Jiang Zhao

    2016-01-01

    Full Text Available This paper presents an improved ant colony algorithm for the path planning of the omnidirectional mobile vehicle. The purpose of the improved ant colony algorithm is to design an appropriate route to connect the starting point and ending point of the environment with obstacles. Ant colony algorithm, which is used to solve the path planning problem, is improved according to the characteristics of the omnidirectional mobile vehicle. And in the improved algorithm, the nonuniform distribution of the initial pheromone and the selection strategy with direction play a very positive role in the path search. The coverage and updating strategy of pheromone is introduced to avoid repeated search reducing the effect of the number of ants on the performance of the algorithm. In addition, the pheromone evaporation coefficient is segmented and adjusted, which can effectively balance the convergence speed and search ability. Finally, this paper provides a theoretical basis for the improved ant colony algorithm by strict mathematical derivation, and some numerical simulations are also given to illustrate the effectiveness of the theoretical results.

  20. An optimized field coverage planning approach for navigation of agricultural robots in fields involving obstacle areas

    DEFF Research Database (Denmark)

    Hameed, Ibahim; Bochtis, D.; Sørensen, C.A.

    2013-01-01

    -field obstacle areas, the headland paths generation for the field and each obstacle area, the implementation of a genetic algorithm to optimize the sequence that the field robot vehicle will follow to visit the blocks, and an algorithmically generation of the task sequences derived from the farmer practices......Technological advances combined with the demand of cost efficiency and environmental considerations lead farmers to review their practices towards the adoption of new managerial approaches including enhanced automation. The application of field robots is one of the most promising advances among....... This approach has proven that it is possible to capture the practices of farmers and embed these practices in an algorithmic description providing a complete field area coverage plan in a form prepared for execution by the navigation system of a field robot....

  1. Heuristic methods for shared backup path protection planning

    DEFF Research Database (Denmark)

    Haahr, Jørgen Thorlund; Stidsen, Thomas Riis; Zachariasen, Martin

    2012-01-01

    schemes are employed. In contrast to manual intervention, automatic protection schemes such as Shared Backup Path Protection (SBPP) can recover from failure quickly and efficiently. SBPP is a simple but efficient protection scheme that can be implemented in backbone networks with technology available...... present heuristic algorithms and lower bound methods for the SBPP planning problem. Experimental results show that the heuristic algorithms are able to find good quality solutions in minutes. A solution gap of less than 3.5% was achieved for more than half of the benchmark instances (and a gap of less...

  2. Autonomous path planning solution for industrial robot manipulator using backpropagation algorithm

    Directory of Open Access Journals (Sweden)

    PeiJiang Yuan

    2015-12-01

    Full Text Available Here, we propose an autonomous path planning solution using backpropagation algorithm. The mechanism of movement used by humans in controlling their arms is analyzed and then applied to control a robot manipulator. Autonomous path planning solution is a numerical method. The model of industrial robot manipulator used in this article is a KUKA KR 210 R2700 EXTRA robot. In order to show the performance of the autonomous path planning solution, an experiment validation of path tracking is provided. Experiment validation consists of implementation of the autonomous path planning solution and the control of physical robot. The process of converging to target solution is provided. The mean absolute error of position for tool center point is also analyzed. Comparison between autonomous path planning solution and the numerical methods based on Newton–Raphson algorithm is provided to demonstrate the efficiency and accuracy of the autonomous path planning solution.

  3. Singularities of robot mechanisms numerical computation and avoidance path planning

    CERN Document Server

    Bohigas, Oriol; Ros, Lluís

    2017-01-01

    This book presents the singular configurations associated with a robot mechanism, together with robust methods for their computation, interpretation, and avoidance path planning. Having such methods is essential as singularities generally pose problems to the normal operation of a robot, but also determine the workspaces and motion impediments of its underlying mechanical structure. A distinctive feature of this volume is that the methods are applicable to nonredundant mechanisms of general architecture, defined by planar or spatial kinematic chains interconnected in an arbitrary way. Moreover, singularities are interpreted as silhouettes of the configuration space when seen from the input or output spaces. This leads to a powerful image that explains the consequences of traversing singular configurations, and all the rich information that can be extracted from them. The problems are solved by means of effective branch-and-prune and numerical continuation methods that are of independent interest in themselves...

  4. Visibility-based optimal path and motion planning

    CERN Document Server

    Wang, Paul Keng-Chieh

    2015-01-01

    This monograph deals with various visibility-based path and motion planning problems motivated by real-world applications such as exploration and mapping planetary surfaces, environmental surveillance using stationary or mobile robots, and imaging of global air/pollutant circulation. The formulation and solution of these problems call for concepts and methods from many areas of applied mathematics including computational geometry, set-covering, non-smooth optimization, combinatorial optimization and optimal control. Emphasis is placed on the formulation of new problems and methods of approach to these problems. Since geometry and visualization play important roles in the understanding of these problems, intuitive interpretations of the basic concepts are presented before detailed mathematical development. The development of a particular topic begins with simple cases illustrated by specific examples, and then progresses forward to more complex cases. The intended readers of this monograph are primarily studen...

  5. Path planning of master-slave manipulator using graphic simulator

    International Nuclear Information System (INIS)

    Lee, J. Y.; Kim, S. H.; Song, T. K.; Park, B. S.; Yoon, J. S.

    2002-01-01

    To handle the high level radioactive materials such as spent fuels remotely, the master-slave manipulator is generally used as a remote handling equipment in the hot cell. To analyze the motion and to implement the training system by virtual reality technology, the simulator for M-S manipulator using the computer graphics is developed. The parts are modelled in 3-D graphics, assembled, and kinematics are assigned. The inverse kinematics of the manipulator is defined, and the slave of manipulator is coupled with master by the manipulator's specification. Also, the virtual work cell is implemented in the graphical environment which is the same as the real environment and the path planning method using the function of the collision detection for a manipulator are proposed. This graphic simulator of manipulator can be effectively used in designing of the maintenance processes for the hot cell equipment and enhance the reliability of the spent fuel management

  6. Autonomous guided vehicles methods and models for optimal path planning

    CERN Document Server

    Fazlollahtabar, Hamed

    2015-01-01

      This book provides readers with extensive information on path planning optimization for both single and multiple Autonomous Guided Vehicles (AGVs), and discusses practical issues involved in advanced industrial applications of AGVs. After discussing previously published research in the field and highlighting the current gaps, it introduces new models developed by the authors with the goal of reducing costs and increasing productivity and effectiveness in the manufacturing industry. The new models address the increasing complexity of manufacturing networks, due for example to the adoption of flexible manufacturing systems that involve automated material handling systems, robots, numerically controlled machine tools, and automated inspection stations, while also considering the uncertainty and stochastic nature of automated equipment such as AGVs. The book discusses and provides solutions to important issues concerning the use of AGVs in the manufacturing industry, including material flow optimization with A...

  7. Making planned paths look more human-like in humanoid robot manipulation planning

    DEFF Research Database (Denmark)

    Zacharias, F.; Schlette, C.; Schmidt, F.

    2011-01-01

    It contradicts the human's expectations when humanoid robots move awkwardly during manipulation tasks. The unnatural motion may be caused by awkward start or goal configurations or by probabilistic path planning processes that are often used. This paper shows that the choice of an arm's target...... for the robot arm....

  8. Mathematical optimization for planning and design of cycle paths

    Energy Technology Data Exchange (ETDEWEB)

    LiÑan Ruiz, R.J.; Perez Aracil, J.; Cabrera Cañizares, V.

    2016-07-01

    The daily need for citizens to move for different activities, whatever its nature, has been greatly affected by the changes. The advantages resulting from the inclusion of the bicycle as a mode of transport and the proliferation of its use among citizens are numerous and extend both in the field of urban mobility and sustainable development.Currently, there are a number of programs for the implementation, promotion or increased public participation related to cycling in cities. But ultimately, each and every one of these initiatives have the same goal, to create a mesh of effective, useful and cycling trails that allow the use of bicycles in preferred routes with high guarantees of security, incorporating bicycle model intermodal urban transport.With the gradual implementation of bike lanes, many people have begun to use them to get around the city. But everything again needs a period of adaptation, and the reality is that the road network for these vehicles is full of obstacles to the rider. The current situation has led to the proposal that many kilometers of cycle paths needed to supply the demand of this mode of transport and, if implemented and planned are correct and sufficient.This paper presents a mathematical programming model for optimal design of a network for cyclists is presented. Specifically, the model determines a network of bicycle infrastructure, appropriate to the characteristics of a network of existing roads.As an application of the proposed model, the result of these experiments give a number of useful conclusions for planning and designing networks of cycle paths from a social perspective, applied to the case in the city of Malaga. (Author)

  9. Minimum dose method for walking-path planning of nuclear facilities

    International Nuclear Information System (INIS)

    Liu, Yong-kuo; Li, Meng-kun; Xie, Chun-li; Peng, Min-jun; Wang, Shuang-yu; Chao, Nan; Liu, Zhong-kun

    2015-01-01

    Highlights: • For radiation environment, the environment model is proposed. • For the least dose walking path problem, a path-planning method is designed. • The path-planning virtual–real mixed simulation program is developed. • The program can plan walking path and simulate. - Abstract: A minimum dose method based on staff walking road network model was proposed for the walking-path planning in nuclear facilities. A virtual–reality simulation program was developed using C# programming language and Direct X engine. The simulation program was used in simulations dealing with virtual nuclear facilities. Simulation results indicated that the walking-path planning method was effective in providing safety for people walking in nuclear facilities

  10. System Design and Implementation of Intelligent Fire Engine Path Planning based on SAT Algorithm

    Institute of Scientific and Technical Information of China (English)

    CAI Li-sha[1; ZENG Wei-peng[1; HAN Bao-ru[1

    2016-01-01

    In this paper, in order to make intelligent fi re car complete autonomy path planning in simulation map. Proposed system design of intelligent fi re car path planning based on SAT. The system includes a planning module, a communication module, a control module. Control module via the communication module upload the initial state and the goal state to planning module. Planning module solve this planning solution,and then download planning solution to control module, control the movement of the car fi re. Experiments show this the system is tracking short time, higher planning effi ciency.

  11. Local Path Planning of Driverless Car Navigation Based on Jump Point Search Method Under Urban Environment

    Directory of Open Access Journals (Sweden)

    Kaijun Zhou

    2017-09-01

    Full Text Available The Jump Point Search (JPS algorithm is adopted for local path planning of the driverless car under urban environment, and it is a fast search method applied in path planning. Firstly, a vector Geographic Information System (GIS map, including Global Positioning System (GPS position, direction, and lane information, is built for global path planning. Secondly, the GIS map database is utilized in global path planning for the driverless car. Then, the JPS algorithm is adopted to avoid the front obstacle, and to find an optimal local path for the driverless car in the urban environment. Finally, 125 different simulation experiments in the urban environment demonstrate that JPS can search out the optimal and safety path successfully, and meanwhile, it has a lower time complexity compared with the Vector Field Histogram (VFH, the Rapidly Exploring Random Tree (RRT, A*, and the Probabilistic Roadmaps (PRM algorithms. Furthermore, JPS is validated usefully in the structured urban environment.

  12. Global optimal path planning of an autonomous vehicle for overtaking a moving obstacle

    Directory of Open Access Journals (Sweden)

    B. Mashadi

    Full Text Available In this paper, the global optimal path planning of an autonomous vehicle for overtaking a moving obstacle is proposed. In this study, the autonomous vehicle overtakes a moving vehicle by performing a double lane-change maneuver after detecting it in a proper distance ahead. The optimal path of vehicle for performing the lane-change maneuver is generated by a path planning program in which the sum of lateral deviation of the vehicle from a reference path and the rate of steering angle become minimum while the lateral acceleration of vehicle does not exceed a safe limit value. A nonlinear optimal control theory with the lateral vehicle dynamics equations and inequality constraint of lateral acceleration are used to generate the path. The indirect approach for solving the optimal control problem is used by applying the calculus of variation and the Pontryagin's Minimum Principle to obtain first-order necessary conditions for optimality. The optimal path is generated as a global optimal solution and can be used as the benchmark of the path generated by the local motion planning of autonomous vehicles. A full nonlinear vehicle model in CarSim software is used for path following simulation by importing path data from the MATLAB code. The simulation results show that the generated path for the autonomous vehicle satisfies all vehicle dynamics constraints and hence is a suitable overtaking path for the following vehicle.

  13. Cooperative path planning for multi-USV based on improved artificial bee colony algorithm

    Science.gov (United States)

    Cao, Lu; Chen, Qiwei

    2018-03-01

    Due to the complex constraints, more uncertain factors and critical real-time demand of path planning for multiple unmanned surface vehicle (multi-USV), an improved artificial bee colony (I-ABC) algorithm were proposed to solve the model of cooperative path planning for multi-USV. First the Voronoi diagram of battle field space is conceived to generate the optimal area of USVs paths. Then the chaotic searching algorithm is used to initialize the collection of paths, which is regard as foods of the ABC algorithm. With the limited data, the initial collection can search the optimal area of paths perfectly. Finally simulations of the multi-USV path planning under various threats have been carried out. Simulation results verify that the I-ABC algorithm can improve the diversity of nectar source and the convergence rate of algorithm. It can increase the adaptability of dynamic battlefield and unexpected threats for USV.

  14. Knowledge-inducing Global Path Planning for Robots in Environment with Hybrid Terrain

    Directory of Open Access Journals (Sweden)

    Yi-nan Guo

    2010-09-01

    Full Text Available In complex environment with hybrid terrain, different regions may have different terrain. Path planning for robots in such environment is an open NP-complete problem, which lacks effective methods. The paper develops a novel global path planning method based on common sense and evolution knowledge by adopting dual evolution structure in culture algorithms. Common sense describes terrain information and feasibility of environment, which is used to evaluate and select the paths. Evolution knowledge describes the angle relationship between the path and the obstacles, or the common segments of paths, which is used to judge and repair infeasible individuals. Taken two types of environments with different obstacles and terrain as examples, simulation results indicate that the algorithm can effectively solve path planning problem in complex environment and decrease the computation complexity for judgment and repair of infeasible individuals. It also can improve the convergence speed and have better computation stability.

  15. Decision Making and Priority Setting: The Evolving Path Towards Universal Health Coverage.

    Science.gov (United States)

    Paolucci, Francesco; Redekop, Ken; Fouda, Ayman; Fiorentini, Gianluca

    2017-12-01

    Health technology assessment (HTA) is widely viewed as an essential component in good universal health coverage (UHC) decision-making in any country. Various HTA tools and metrics have been developed and refined over the years, including systematic literature reviews (Cochrane), economic modelling, and cost-effectiveness ratios and acceptability curves. However, while the cost-effectiveness ratio is faithfully reported in most full economic evaluations, it is viewed by many as an insufficient basis for reimbursement decisions. Emotional debates about the reimbursement of cancer drugs, orphan drugs, and end-of-life treatments have revealed fundamental disagreements about what should and should not be considered in reimbursement decisions. Part of this disagreement seems related to the equity-efficiency tradeoff, which reflects fundamental differences in priorities. All in all, it is clear that countries aiming to improve UHC policies will have to go beyond the capacity building needed to utilize the available HTA toolbox. Multi-criteria decision analysis (MCDA) offers a more comprehensive tool for reimbursement decisions where different weights of different factors/attributes can give policymakers important insights to consider. Sooner or later, every country will have to develop their own way to carefully combine the results of those tools with their own priorities. In the end, all policymaking is based on a mix of facts and values.

  16. Research and application of genetic algorithm in path planning of logistics distribution vehicle

    Science.gov (United States)

    Wang, Yong; Zhou, Heng; Wang, Ying

    2017-08-01

    The core of the logistics distribution system is the vehicle routing planning, research path planning problem, provide a better solution has become an important issue. In order to provide the decision support for logistics and distribution operations, this paper studies the problem of vehicle routing with capacity constraints (CVRP). By establishing a mathematical model, the genetic algorithm is used to plan the path of the logistics vehicle to meet the minimum logistics and transportation costs.

  17. Robotic path-finding in inverse treatment planning for stereotactic radiosurgery with continuous dose delivery

    Energy Technology Data Exchange (ETDEWEB)

    Vandewouw, Marlee M., E-mail: marleev@mie.utoronto.ca; Aleman, Dionne M. [Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8 (Canada); Jaffray, David A. [Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario M5G 2M9 (Canada)

    2016-08-15

    Purpose: Continuous dose delivery in radiation therapy treatments has been shown to decrease total treatment time while improving the dose conformity and distribution homogeneity over the conventional step-and-shoot approach. The authors develop an inverse treatment planning method for Gamma Knife® Perfexion™ that continuously delivers dose along a path in the target. Methods: The authors’ method is comprised of two steps: find a path within the target, then solve a mixed integer optimization model to find the optimal collimator configurations and durations along the selected path. Robotic path-finding techniques, specifically, simultaneous localization and mapping (SLAM) using an extended Kalman filter, are used to obtain a path that travels sufficiently close to selected isocentre locations. SLAM is novelly extended to explore a 3D, discrete environment, which is the target discretized into voxels. Further novel extensions are incorporated into the steering mechanism to account for target geometry. Results: The SLAM method was tested on seven clinical cases and compared to clinical, Hamiltonian path continuous delivery, and inverse step-and-shoot treatment plans. The SLAM approach improved dose metrics compared to the clinical plans and Hamiltonian path continuous delivery plans. Beam-on times improved over clinical plans, and had mixed performance compared to Hamiltonian path continuous plans. The SLAM method is also shown to be robust to path selection inaccuracies, isocentre selection, and dose distribution. Conclusions: The SLAM method for continuous delivery provides decreased total treatment time and increased treatment quality compared to both clinical and inverse step-and-shoot plans, and outperforms existing path methods in treatment quality. It also accounts for uncertainty in treatment planning by accommodating inaccuracies.

  18. Robotic path-finding in inverse treatment planning for stereotactic radiosurgery with continuous dose delivery

    International Nuclear Information System (INIS)

    Vandewouw, Marlee M.; Aleman, Dionne M.; Jaffray, David A.

    2016-01-01

    Purpose: Continuous dose delivery in radiation therapy treatments has been shown to decrease total treatment time while improving the dose conformity and distribution homogeneity over the conventional step-and-shoot approach. The authors develop an inverse treatment planning method for Gamma Knife® Perfexion™ that continuously delivers dose along a path in the target. Methods: The authors’ method is comprised of two steps: find a path within the target, then solve a mixed integer optimization model to find the optimal collimator configurations and durations along the selected path. Robotic path-finding techniques, specifically, simultaneous localization and mapping (SLAM) using an extended Kalman filter, are used to obtain a path that travels sufficiently close to selected isocentre locations. SLAM is novelly extended to explore a 3D, discrete environment, which is the target discretized into voxels. Further novel extensions are incorporated into the steering mechanism to account for target geometry. Results: The SLAM method was tested on seven clinical cases and compared to clinical, Hamiltonian path continuous delivery, and inverse step-and-shoot treatment plans. The SLAM approach improved dose metrics compared to the clinical plans and Hamiltonian path continuous delivery plans. Beam-on times improved over clinical plans, and had mixed performance compared to Hamiltonian path continuous plans. The SLAM method is also shown to be robust to path selection inaccuracies, isocentre selection, and dose distribution. Conclusions: The SLAM method for continuous delivery provides decreased total treatment time and increased treatment quality compared to both clinical and inverse step-and-shoot plans, and outperforms existing path methods in treatment quality. It also accounts for uncertainty in treatment planning by accommodating inaccuracies.

  19. Curvature-Continuous 3D Path-Planning Using QPMI Method

    Directory of Open Access Journals (Sweden)

    Seong-Ryong Chang

    2015-06-01

    Full Text Available It is impossible to achieve vertex movement and rapid velocity control in aerial robots and aerial vehicles because of momentum from the air. A continuous-curvature path ensures such robots and vehicles can fly with stable and continuous movements. General continuous path-planning methods use spline interpolation, for example B-spline and Bézier curves. However, these methods cannot be directly applied to continuous path planning in a 3D space. These methods use a subset of the waypoints to decide curvature and some waypoints are not included in the planned path. This paper proposes a method for constructing a curvature-continuous path in 3D space that includes every waypoint. The movements in each axis, x, y and z, are separated by the parameter u. Waypoint groups are formed, each with its own continuous path derived using quadratic polynomial interpolation. The membership function then combines each continuous path into one continuous path. The continuity of the path is verified and the curvature-continuous path is produced using the proposed method.

  20. An adaptive dual-optimal path-planning technique for unmanned air vehicles

    Directory of Open Access Journals (Sweden)

    Whitfield Clifford A.

    2016-01-01

    Full Text Available A multi-objective technique for unmanned air vehicle path-planning generation through task allocation has been developed. The dual-optimal path-planning technique generates real-time adaptive flight paths based on available flight windows and environmental influenced objectives. The environmentally-influenced flight condition determines the aircraft optimal orientation within a downstream virtual window of possible vehicle destinations that is based on the vehicle’s kinematics. The intermittent results are then pursued by a dynamic optimization technique to determine the flight path. This path-planning technique is a multi-objective optimization procedure consisting of two goals that do not require additional information to combine the conflicting objectives into a single-objective. The technique was applied to solar-regenerative high altitude long endurance flight which can benefit significantly from an adaptive real-time path-planning technique. The objectives were to determine the minimum power required flight paths while maintaining maximum solar power for continual surveillance over an area of interest (AOI. The simulated path generation technique prolonged the flight duration over a sustained turn loiter flight path by approximately 2 months for a year of flight. The potential for prolonged solar powered flight was consistent for all latitude locations, including 2 months of available flight at 60° latitude, where sustained turn flight was no longer capable.

  1. Decision-making in healthcare: a practical application of partial least square path modelling to coverage of newborn screening programmes.

    Science.gov (United States)

    Fischer, Katharina E

    2012-08-02

    Decision-making in healthcare is complex. Research on coverage decision-making has focused on comparative studies for several countries, statistical analyses for single decision-makers, the decision outcome and appraisal criteria. Accounting for decision processes extends the complexity, as they are multidimensional and process elements need to be regarded as latent constructs (composites) that are not observed directly. The objective of this study was to present a practical application of partial least square path modelling (PLS-PM) to evaluate how it offers a method for empirical analysis of decision-making in healthcare. Empirical approaches that applied PLS-PM to decision-making in healthcare were identified through a systematic literature search. PLS-PM was used as an estimation technique for a structural equation model that specified hypotheses between the components of decision processes and the reasonableness of decision-making in terms of medical, economic and other ethical criteria. The model was estimated for a sample of 55 coverage decisions on the extension of newborn screening programmes in Europe. Results were evaluated by standard reliability and validity measures for PLS-PM. After modification by dropping two indicators that showed poor measures in the measurement models' quality assessment and were not meaningful for newborn screening, the structural equation model estimation produced plausible results. The presence of three influences was supported: the links between both stakeholder participation or transparency and the reasonableness of decision-making; and the effect of transparency on the degree of scientific rigour of assessment. Reliable and valid measurement models were obtained to describe the composites of 'transparency', 'participation', 'scientific rigour' and 'reasonableness'. The structural equation model was among the first applications of PLS-PM to coverage decision-making. It allowed testing of hypotheses in situations where there

  2. Decision-making in healthcare: a practical application of partial least square path modelling to coverage of newborn screening programmes

    Directory of Open Access Journals (Sweden)

    Fischer Katharina E

    2012-08-01

    Full Text Available Abstract Background Decision-making in healthcare is complex. Research on coverage decision-making has focused on comparative studies for several countries, statistical analyses for single decision-makers, the decision outcome and appraisal criteria. Accounting for decision processes extends the complexity, as they are multidimensional and process elements need to be regarded as latent constructs (composites that are not observed directly. The objective of this study was to present a practical application of partial least square path modelling (PLS-PM to evaluate how it offers a method for empirical analysis of decision-making in healthcare. Methods Empirical approaches that applied PLS-PM to decision-making in healthcare were identified through a systematic literature search. PLS-PM was used as an estimation technique for a structural equation model that specified hypotheses between the components of decision processes and the reasonableness of decision-making in terms of medical, economic and other ethical criteria. The model was estimated for a sample of 55 coverage decisions on the extension of newborn screening programmes in Europe. Results were evaluated by standard reliability and validity measures for PLS-PM. Results After modification by dropping two indicators that showed poor measures in the measurement models’ quality assessment and were not meaningful for newborn screening, the structural equation model estimation produced plausible results. The presence of three influences was supported: the links between both stakeholder participation or transparency and the reasonableness of decision-making; and the effect of transparency on the degree of scientific rigour of assessment. Reliable and valid measurement models were obtained to describe the composites of ‘transparency’, ‘participation’, ‘scientific rigour’ and ‘reasonableness’. Conclusions The structural equation model was among the first applications of PLS-PM to

  3. Planning paths through a spatial hierarchy - Eliminating stair-stepping effects

    Science.gov (United States)

    Slack, Marc G.

    1989-01-01

    Stair-stepping effects are a result of the loss of spatial continuity resulting from the decomposition of space into a grid. This paper presents a path planning algorithm which eliminates stair-stepping effects induced by the grid-based spatial representation. The algorithm exploits a hierarchical spatial model to efficiently plan paths for a mobile robot operating in dynamic domains. The spatial model and path planning algorithm map to a parallel machine, allowing the system to operate incrementally, thereby accounting for unexpected events in the operating space.

  4. Interactive multi-objective path planning through a palette-based user interface

    Science.gov (United States)

    Shaikh, Meher T.; Goodrich, Michael A.; Yi, Daqing; Hoehne, Joseph

    2016-05-01

    n a problem where a human uses supervisory control to manage robot path-planning, there are times when human does the path planning, and if satisfied commits those paths to be executed by the robot, and the robot executes that plan. In planning a path, the robot often uses an optimization algorithm that maximizes or minimizes an objective. When a human is assigned the task of path planning for robot, the human may care about multiple objectives. This work proposes a graphical user interface (GUI) designed for interactive robot path-planning when an operator may prefer one objective over others or care about how multiple objectives are traded off. The GUI represents multiple objectives using the metaphor of an artist's palette. A distinct color is used to represent each objective, and tradeoffs among objectives are balanced in a manner that an artist mixes colors to get the desired shade of color. Thus, human intent is analogous to the artist's shade of color. We call the GUI an "Adverb Palette" where the word "Adverb" represents a specific type of objective for the path, such as the adverbs "quickly" and "safely" in the commands: "travel the path quickly", "make the journey safely". The novel interactive interface provides the user an opportunity to evaluate various alternatives (that tradeoff between different objectives) by allowing her to visualize the instantaneous outcomes that result from her actions on the interface. In addition to assisting analysis of various solutions given by an optimization algorithm, the palette has additional feature of allowing the user to define and visualize her own paths, by means of waypoints (guiding locations) thereby spanning variety for planning. The goal of the Adverb Palette is thus to provide a way for the user and robot to find an acceptable solution even though they use very different representations of the problem. Subjective evaluations suggest that even non-experts in robotics can carry out the planning tasks with a

  5. Path planning in uncertain flow fields using ensemble method

    KAUST Repository

    Wang, Tong; Le Maî tre, Olivier P.; Hoteit, Ibrahim; Knio, Omar

    2016-01-01

    , we predict the path that minimizes the travel time by solving a boundary value problem (BVP), based on the Pontryagin maximum principle. A family of backward-in-time trajectories starting at the end position is used to generate suitable initial values

  6. Vehicle path-planning in three dimensions using optics analogs for optimizing visibility and energy cost

    Science.gov (United States)

    Rowe, Neil C.; Lewis, David H.

    1989-01-01

    Path planning is an important issue for space robotics. Finding safe and energy-efficient paths in the presence of obstacles and other constraints can be complex although important. High-level (large-scale) path planning for robotic vehicles was investigated in three-dimensional space with obstacles, accounting for: (1) energy costs proportional to path length; (2) turn costs where paths change trajectory abruptly; and (3) safety costs for the danger associated with traversing a particular path due to visibility or invisibility from a fixed set of observers. Paths optimal with respect to these cost factors are found. Autonomous or semi-autonomous vehicles were considered operating either in a space environment around satellites and space platforms, or aircraft, spacecraft, or smart missiles operating just above lunar and planetary surfaces. One class of applications concerns minimizing detection, as for example determining the best way to make complex modifications to a satellite without being observed by hostile sensors; another example is verifying there are no paths (holes) through a space defense system. Another class of applications concerns maximizing detection, as finding a good trajectory between mountain ranges of a planet while staying reasonably close to the surface, or finding paths for a flight between two locations that maximize the average number of triangulation points available at any time along the path.

  7. Hierarchical path planning and control of a small fixed-wing UAV: Theory and experimental validation

    Science.gov (United States)

    Jung, Dongwon

    2007-12-01

    Recently there has been a tremendous growth of research emphasizing control of unmanned aerial vehicles (UAVs) either in isolation or in teams. As a matter of fact, UAVs increasingly find their way into military and law enforcement applications (e.g., reconnaissance, remote delivery of urgent equipment/material, resource assessment, environmental monitoring, battlefield monitoring, ordnance delivery, etc.). This trend will continue in the future, as UAVs are poised to replace the human-in-the-loop during dangerous missions. Civilian applications of UAVs are also envisioned such as crop dusting, geological surveying, search and rescue operations, etc. In this thesis we propose a new online multiresolution path planning algorithm for a small UAV with limited on-board computational resources. The proposed approach assumes that the UAV has detailed information of the environment and the obstacles only in its vicinity. Information about far-away obstacles is also available, albeit less accurately. The proposed algorithm uses the fast lifting wavelet transform (FLWT) to get a multiresolution cell decomposition of the environment, whose dimension is commensurate to the on-board computational resources. A topological graph representation of the multiresolution cell decomposition is constructed efficiently, directly from the approximation and detail wavelet coefficients. Dynamic path planning is sequentially executed for an optimal path using the A* algorithm over the resulting graph. The proposed path planning algorithm is implemented on-line on a small autopilot. Comparisons with the standard D*-lite algorithm are also presented. We also investigate the problem of generating a smooth, planar reference path from a discrete optimal path. Upon the optimal path being represented as a sequence of cells in square geometry, we derive a smooth B-spline path that is constrained inside a channel that is induced by the geometry of the cells. To this end, a constrained optimization

  8. Path Planning Software and Graphics Interface for an Autonomous Vehicle, Accounting for Terrain Features

    National Research Council Canada - National Science Library

    Hurezeanu, Vlad

    2000-01-01

    .... This vehicle performs tasks to include surveying fields, laying mines, and teleoperation. The capability of the vehicle will be increased if its supporting software plans paths that take into account the terrain features...

  9. A Distributed Framework for Real Time Path Planning in Practical Multi-agent Systems

    KAUST Repository

    Abdelkader, Mohamed; Jaleel, Hassan; Shamma, Jeff S.

    2017-01-01

    We present a framework for distributed, energy efficient, and real time implementable algorithms for path planning in multi-agent systems. The proposed framework is presented in the context of a motivating example of capture the flag which

  10. Cooperative Path Planning and Constraints Analysis for Master-Slave Industrial Robots

    Directory of Open Access Journals (Sweden)

    Yahui Gan

    2012-09-01

    Full Text Available A strategy of cooperative path planning for a master-slave multiple robot system is presented in this paper. The path planning method is based on motion constraints between the end-effectors of cooperative robots. Cooperation motions have been classified into three types by relative motions between end-effectors of master and slave robots, which is concurrent cooperation, coupled synchronous cooperation and combined synchronous cooperation. Based on this classification, position /orientation constraints and joint velocity constraints are explored in-depth here. In order to validate the path planning method and the theoretical developments in motion constraints analysis, representative experiments based on two industrial robots, Motoman VA1400 and HP20, are provided at the end of the paper. The experimental results have proved both the effectiveness of the path planning method and the correctness of the constraints analysis.

  11. Time-optimal path planning in uncertain flow fields using ensemble method

    KAUST Repository

    Wang, Tong; Le Maitre, Olivier; Hoteit, Ibrahim; Knio, Omar

    2016-01-01

    the performance of sampling strategy, and develop insight into extensions dealing with regional or general circulation models. In particular, the ensemble method enables us to perform a statistical analysis of travel times, and consequently develop a path planning

  12. 75 FR 34537 - Interim Final Rules for Group Health Plans and Health Insurance Coverage Relating to Status as a...

    Science.gov (United States)

    2010-06-17

    ... 45 CFR Part 147 Group Health Plans and Health Insurance Coverage Relating to Status as a... for Group Health Plans and Health Insurance Coverage Relating to Status as a Grandfathered Health Plan... and Insurance Oversight, Department of Health and Human Services. ACTION: Interim final rules with...

  13. 75 FR 34571 - Group Health Plans and Health Insurance Coverage Rules Relating to Status as a Grandfathered...

    Science.gov (United States)

    2010-06-17

    ... Group Health Plans and Health Insurance Coverage Rules Relating to Status as a Grandfathered Health Plan... of Consumer Information and Insurance Oversight of the U.S. Department of Health and Human Services... health insurance coverage offered in connection with a group health plan under the Employee Retirement...

  14. 75 FR 41726 - Interim Final Rules for Group Health Plans and Health Insurance Issuers Relating to Coverage of...

    Science.gov (United States)

    2010-07-19

    ... Health Plans and Health Insurance Issuers Relating to Coverage of Preventive Services Under the Patient... and health insurance coverage in the group and individual markets under provisions of the Patient... plans and group health insurance issuers for plan years beginning on or after September 23, 2010. These...

  15. 75 FR 70159 - Group Health Plans and Health Insurance Coverage Rules Relating to Status as a Grandfathered...

    Science.gov (United States)

    2010-11-17

    ... Group Health Plans and Health Insurance Coverage Rules Relating to Status as a Grandfathered Health Plan... contracts of insurance. The temporary regulations provide guidance to employers, group health plans, and health insurance issuers providing group health insurance coverage. The IRS is issuing the temporary...

  16. Defining Pathways and Trade-offs Toward Universal Health Coverage Comment on “Ethical Perspective: Five Unacceptable Trade-offs on the Path to Universal Health Coverage”

    Directory of Open Access Journals (Sweden)

    Stéphane Verguet

    2016-07-01

    Full Text Available The World Health Organization’s (WHO’s World Health Report 2010, “Health systems financing, the path to universal coverage,” promoted universal health coverage (UHC as an aspirational objective for country health systems. Yet, in addition to the dimensions of services and coverage, distribution of coverage in the population, and financial risk protection highlighted by the report, the consideration of the budget constraint should be further strengthened in the ensuing debate on resource allocation toward UHC. Beyond the substantial financial constraints faced by low- and middle-income countries, additional considerations, such as the geographical context, the underlying country infrastructure, and the architecture of health systems, determine the feasibility, effectiveness, quality and cost of healthcare delivery. Therefore, increased production and use of local evidence tied to the criteria of health benefits, equity, financial risk protection, and costs accompanying health delivery are needed so that to highlight pathways and acceptable trade-offs toward UHC.

  17. Optimized path planning for soft tissue resection via laser vaporization

    Science.gov (United States)

    Ross, Weston; Cornwell, Neil; Tucker, Matthew; Mann, Brian; Codd, Patrick

    2018-02-01

    Robotic and robotic-assisted surgeries are becoming more prevalent with the promise of improving surgical outcomes through increased precision, reduced operating times, and minimally invasive procedures. The handheld laser scalpel in neurosurgery has been shown to provide a more gentle approach to tissue manipulation on or near critical structures over classical tooling, though difficulties of control have prevented large scale adoption of the tool. This paper presents a novel approach to generating a cutting path for the volumetric resection of tissue using a computer-guided laser scalpel. A soft tissue ablation simulator is developed and used in conjunction with an optimization routine to select parameters which maximize the total resection of target tissue while minimizing the damage to surrounding tissue. The simulator predicts the ablative properties of tissue from an interrogation cut for tuning and simulates the removal of a tumorous tissue embedded on the surface of healthy tissue using a laser scalpel. We demonstrate the ability to control depth and smoothness of cut using genetic algorithms to optimize the ablation parameters and cutting path. The laser power level, cutting rate and spacing between cuts are optimized over multiple surface cuts to achieve the desired resection volumes.

  18. Strategic Path Planning by Sequential Parametric Bayesian Decisions

    Directory of Open Access Journals (Sweden)

    Baro Hyun

    2013-11-01

    Full Text Available The objective of this research is to generate a path for a mobile agent that carries sensors used for classification, where the path is to optimize strategic objectives that account for misclassification and the consequences of misclassification, and where the weights assigned to these consequences are chosen by a strategist. We propose a model that accounts for the interaction between the agent kinematics (i.e., the ability to move, informatics (i.e., the ability to process data to information, classification (i.e., the ability to classify objects based on the information, and strategy (i.e., the mission objective. Within this model, we pose and solve a sequential decision problem that accounts for strategist preferences and the solution to the problem yields a sequence of kinematic decisions of a moving agent. The solution of the sequential decision problem yields the following flying tactics: “approach only objects whose suspected identity matters to the strategy”. These tactics are numerically illustrated in several scenarios.

  19. Clinical implementation of coverage probability planning for nodal boosting in locally advanced cervical cancer

    DEFF Research Database (Denmark)

    Ramlov, Anne; Assenholt, Marianne S; Jensen, Maria F

    2017-01-01

    PURPOSE: To implement coverage probability (CovP) for dose planning of simultaneous integrated boost (SIB) of pathologic lymph nodes in locally advanced cervical cancer (LACC). MATERIAL AND METHODS: CovP constraints for SIB of the pathological nodal target (PTV-N) with a central dose peak...

  20. Reasoning on the Self-Organizing Incremental Associative Memory for Online Robot Path Planning

    Science.gov (United States)

    Kawewong, Aram; Honda, Yutaro; Tsuboyama, Manabu; Hasegawa, Osamu

    Robot path-planning is one of the important issues in robotic navigation. This paper presents a novel robot path-planning approach based on the associative memory using Self-Organizing Incremental Neural Networks (SOINN). By the proposed method, an environment is first autonomously divided into a set of path-fragments by junctions. Each fragment is represented by a sequence of preliminarily generated common patterns (CPs). In an online manner, a robot regards the current path as the associative path-fragments, each connected by junctions. The reasoning technique is additionally proposed for decision making at each junction to speed up the exploration time. Distinct from other methods, our method does not ignore the important information about the regions between junctions (path-fragments). The resultant number of path-fragments is also less than other method. Evaluation is done via Webots physical 3D-simulated and real robot experiments, where only distance sensors are available. Results show that our method can represent the environment effectively; it enables the robot to solve the goal-oriented navigation problem in only one episode, which is actually less than that necessary for most of the Reinforcement Learning (RL) based methods. The running time is proved finite and scales well with the environment. The resultant number of path-fragments matches well to the environment.

  1. Autonomous Path Planning for Road Vehicles in Narrow Environments: An Efficient Continuous Curvature Approach

    Directory of Open Access Journals (Sweden)

    Domokos Kiss

    2017-01-01

    Full Text Available In this paper we introduce a novel method for obtaining good quality paths for autonomous road vehicles (e.g., cars or buses in narrow environments. There are many traffic situations in urban scenarios where nontrivial maneuvering in narrow places is necessary. Navigating in cluttered parking lots or having to avoid obstacles blocking the way and finding a detour even in narrow streets are challenging, especially if the vehicle has large dimensions like a bus. We present a combined approximation-based approach to solve the path planning problem in such situations. Our approach consists of a global planner which generates a preliminary path consisting of straight and turning-in-place primitives and a local planner which is used to make the preliminary path feasible to car-like vehicles. The approximation methodology is well known in the literature; however, both components proposed in this paper differ from existing similar planning methods. The approximation process with the proposed local planner is proven to be convergent for any preliminary global paths. The resulting path has continuous curvature which renders our method well suited for application on real vehicles. Simulation experiments show that the proposed method outperforms similar approaches in terms of path quality in complicated planning tasks.

  2. A hybrid metaheuristic DE/CS algorithm for UCAV three-dimension path planning.

    Science.gov (United States)

    Wang, Gaige; Guo, Lihong; Duan, Hong; Wang, Heqi; Liu, Luo; Shao, Mingzhen

    2012-01-01

    Three-dimension path planning for uninhabited combat air vehicle (UCAV) is a complicated high-dimension optimization problem, which primarily centralizes on optimizing the flight route considering the different kinds of constrains under complicated battle field environments. A new hybrid metaheuristic differential evolution (DE) and cuckoo search (CS) algorithm is proposed to solve the UCAV three-dimension path planning problem. DE is applied to optimize the process of selecting cuckoos of the improved CS model during the process of cuckoo updating in nest. The cuckoos can act as an agent in searching the optimal UCAV path. And then, the UCAV can find the safe path by connecting the chosen nodes of the coordinates while avoiding the threat areas and costing minimum fuel. This new approach can accelerate the global convergence speed while preserving the strong robustness of the basic CS. The realization procedure for this hybrid metaheuristic approach DE/CS is also presented. In order to make the optimized UCAV path more feasible, the B-Spline curve is adopted for smoothing the path. To prove the performance of this proposed hybrid metaheuristic method, it is compared with basic CS algorithm. The experiment shows that the proposed approach is more effective and feasible in UCAV three-dimension path planning than the basic CS model.

  3. Three-Dimensional Path Planning Software-Assisted Transjugular Intrahepatic Portosystemic Shunt: A Technical Modification

    Energy Technology Data Exchange (ETDEWEB)

    Tsauo, Jiaywei, E-mail: 80732059@qq.com; Luo, Xuefeng, E-mail: luobo-913@126.com [West China Hospital of Sichuan University, Institute of Interventional Radiology (China); Ye, Linchao, E-mail: linchao.ye@siemens.com [Siemens Ltd, Healthcare Sector (China); Li, Xiao, E-mail: simonlixiao@gmail.com [West China Hospital of Sichuan University, Institute of Interventional Radiology (China)

    2015-06-15

    PurposeThis study was designed to report our results with a modified technique of three-dimensional (3D) path planning software assisted transjugular intrahepatic portosystemic shunt (TIPS).Methods3D path planning software was recently developed to facilitate TIPS creation by using two carbon dioxide portograms acquired at least 20° apart to generate a 3D path for overlay needle guidance. However, one shortcoming is that puncturing along the overlay would be technically impossible if the angle of the liver access set and the angle of the 3D path are not the same. To solve this problem, a prototype 3D path planning software was fitted with a utility to calculate the angle of the 3D path. Using this, we modified the angle of the liver access set accordingly during the procedure in ten patients.ResultsFailure for technical reasons occurred in three patients (unsuccessful wedged hepatic venography in two cases, software technical failure in one case). The procedure was successful in the remaining seven patients, and only one needle pass was required to obtain portal vein access in each case. The course of puncture was comparable to the 3D path in all patients. No procedure-related complication occurred following the procedures.ConclusionsAdjusting the angle of the liver access set to match the angle of the 3D path determined by the software appears to be a favorable modification to the technique of 3D path planning software assisted TIPS.

  4. The intertwining paths of the density managment and riparian buffer study and the Northwest Forest Plan

    Science.gov (United States)

    Kenneth J. Ruzicka; Deanna H. Olson; Klaus J. Puettmann

    2013-01-01

    Initiated simultaneously, the Density Management and Riparian Buff er Study of western Oregon and the Northwest Forest Plan have had intertwining paths related to federal forest management and policy changes in the Pacifi c Northwest over the last 15 to 20 years. We briefl y discuss the development of the Northwest Forest Plan and how it changed the way forest policy...

  5. Policy Choices for Progressive Realization of Universal Health Coverage Comment on "Ethical Perspective: Five Unacceptable Trade-offs on the Path to Universal Health Coverage".

    Science.gov (United States)

    Tangcharoensathien, Viroj; Patcharanarumol, Walaiporn; Panichkriangkrai, Warisa; Sommanustweechai, Angkana

    2016-07-31

    In responses to Norheim's editorial, this commentary offers reflections from Thailand, how the five unacceptable trade-offs were applied to the universal health coverage (UHC) reforms between 1975 and 2002 when the whole 64 million people were covered by one of the three public health insurance systems. This commentary aims to generate global discussions on how best UHC can be gradually achieved. Not only the proposed five discrete trade-offs within each dimension, there are also trade-offs between the three dimensions of UHC such as population coverage, service coverage and cost coverage. Findings from Thai UHC show that equity is applied for the population coverage extension, when the low income households and the informal sector were the priority population groups for coverage extension by different prepayment schemes in 1975 and 1984, respectively. With an exception of public sector employees who were historically covered as part of fringe benefits were covered well before the poor. The private sector employees were covered last in 1990. Historically, Thailand applied a comprehensive benefit package where a few items are excluded using the negative list; until there was improved capacities on technology assessment that cost-effectiveness are used for the inclusion of new interventions into the benefit package. Not only cost-effectiveness, but long term budget impact, equity and ethical considerations are taken into account. Cost coverage is mostly determined by the fiscal capacities. Close ended budget with mix of provider payment methods are used as a tool for trade-off service coverage and financial risk protection. Introducing copayment in the context of fee-for-service can be harmful to beneficiaries due to supplier induced demands, inefficiency and unpredictable out of pocket payment by households. UHC achieves favorable outcomes as it was implemented when there was a full geographical coverage of primary healthcare coverage in all districts and sub

  6. A NEPA compliance strategy plan for providing programmatic coverage to agency problems

    International Nuclear Information System (INIS)

    Eccleston, C.H.

    1994-04-01

    The National Environmental Policy Act (NEPA) of 1969, requires that all federal actions be reviewed before making a final decision to pursue a proposed action or one of its reasonable alternatives. The NEPA process is expected to begin early in the planning process. This paper discusses an approach for providing efficient and comprehensive NEPA coverage to large-scale programs. Particular emphasis has been given to determining bottlenecks and developing workarounds to such problems. Specifically, the strategy is designed to meet four specific goals: (1) provide comprehensive coverage, (2) reduce compliance cost/time, (3) prevent project delays, and (4) reduce document obsolescence

  7. Mobile Robots Path Planning Using the Overall Conflict Resolution and Time Baseline Coordination

    Directory of Open Access Journals (Sweden)

    Yong Ma

    2014-01-01

    Full Text Available This paper aims at resolving the path planning problem in a time-varying environment based on the idea of overall conflict resolution and the algorithm of time baseline coordination. The basic task of the introduced path planning algorithms is to fulfill the automatic generation of the shortest paths from the defined start poses to their end poses with consideration of generous constraints for multiple mobile robots. Building on this, by using the overall conflict resolution, within the polynomial based paths, we take into account all the constraints including smoothness, motion boundary, kinematics constraints, obstacle avoidance, and safety constraints among robots together. And time baseline coordination algorithm is proposed to process the above formulated problem. The foremost strong point is that much time can be saved with our approach. Numerical simulations verify the effectiveness of our approach.

  8. Path Planning and Navigation for Mobile Robots in a Hybrid Sensor Network without Prior Location Information

    Directory of Open Access Journals (Sweden)

    Zheng Zhang

    2013-03-01

    Full Text Available In a hybrid wireless sensor network with mobile and static nodes, which have no prior geographical knowledge, successful navigation for mobile robots is one of the main challenges. In this paper, we propose two novel navigation algorithms for outdoor environments, which permit robots to travel from one static node to another along a planned path in the sensor field, namely the RAC and the IMAP algorithms. Using this, the robot can navigate without the help of a map, GPS or extra sensor modules, only using the received signal strength indication (RSSI and odometry. Therefore, our algorithms have the advantage of being cost-effective. In addition, a path planning algorithm to schedule mobile robots' travelling paths is presented, which focuses on shorter distances and robust paths for robots by considering the RSSI-Distance characteristics. The simulations and experiments conducted with an autonomous mobile robot show the effectiveness of the proposed algorithms in an outdoor environment.

  9. 75 FR 27141 - Group Health Plans and Health Insurance Issuers Providing Dependent Coverage of Children to Age...

    Science.gov (United States)

    2010-05-13

    ... Group Health Plans and Health Insurance Issuers Providing Dependent Coverage of Children to Age 26 Under... Information and Insurance Oversight of the U.S. Department of Health and Human Services are issuing substantially similar interim final regulations with respect to group health plans and health insurance coverage...

  10. 75 FR 41787 - Requirement for Group Health Plans and Health Insurance Issuers To Provide Coverage of Preventive...

    Science.gov (United States)

    2010-07-19

    ... Requirement for Group Health Plans and Health Insurance Issuers To Provide Coverage of Preventive Services... Insurance Oversight of the U.S. Department of Health and Human Services are issuing substantially similar interim final regulations with respect to group health plans and health insurance coverage offered in...

  11. A novel approach for multiple mobile objects path planning: Parametrization method and conflict resolution strategy

    International Nuclear Information System (INIS)

    Ma, Yong; Wang, Hongwei; Zamirian, M.

    2012-01-01

    We present a new approach containing two steps to determine conflict-free paths for mobile objects in two and three dimensions with moving obstacles. Firstly, the shortest path of each object is set as goal function which is subject to collision-avoidance criterion, path smoothness, and velocity and acceleration constraints. This problem is formulated as calculus of variation problem (CVP). Using parametrization method, CVP is converted to time-varying nonlinear programming problems (TNLPP) and then resolved. Secondly, move sequence of object is assigned by priority scheme; conflicts are resolved by multilevel conflict resolution strategy. Approach efficiency is confirmed by numerical examples. -- Highlights: ► Approach with parametrization method and conflict resolution strategy is proposed. ► Approach fits for multi-object paths planning in two and three dimensions. ► Single object path planning and multi-object conflict resolution are orderly used. ► Path of each object obtained with parameterization method in the first phase. ► Conflict-free paths gained by multi-object conflict resolution in the second phase.

  12. Minimum Time Path Planning for Robotic Manipulator in Drilling/ Spot Welding Tasks

    Directory of Open Access Journals (Sweden)

    Qiang Zhang

    2016-04-01

    Full Text Available In this paper, a minimum time path planning strategy is proposed for multi points manufacturing problems in drilling/spot welding tasks. By optimizing the travelling schedule of the set points and the detailed transfer path between points, the minimum time manufacturing task is realized under fully utilizing the dynamic performance of robotic manipulator. According to the start-stop movement in drilling/spot welding task, the path planning problem can be converted into a traveling salesman problem (TSP and a series of point to point minimum time transfer path planning problems. Cubic Hermite interpolation polynomial is used to parameterize the transfer path and then the path parameters are optimized to obtain minimum point to point transfer time. A new TSP with minimum time index is constructed by using point-point transfer time as the TSP parameter. The classical genetic algorithm (GA is applied to obtain the optimal travelling schedule. Several minimum time drilling tasks of a 3-DOF robotic manipulator are used as examples to demonstrate the effectiveness of the proposed approach.

  13. Sensor-Oriented Path Planning for Multiregion Surveillance with a Single Lightweight UAV SAR.

    Science.gov (United States)

    Li, Jincheng; Chen, Jie; Wang, Pengbo; Li, Chunsheng

    2018-02-11

    In the surveillance of interested regions by unmanned aerial vehicle (UAV), system performance relies greatly on the motion control strategy of the UAV and the operation characteristics of the onboard sensors. This paper investigates the 2D path planning problem for the lightweight UAV synthetic aperture radar (SAR) system in an environment of multiple regions of interest (ROIs), the sizes of which are comparable to the radar swath width. Taking into account the special requirements of the SAR system on the motion of the platform, we model path planning for UAV SAR as a constrained multiobjective optimization problem (MOP). Based on the fact that the UAV route can be designed in the map image, an image-based path planner is proposed in this paper. First, the neighboring ROIs are merged by the morphological operation. Then, the parts of routes for data collection of the ROIs can be located according to the geometric features of the ROIs and the observation geometry of UAV SAR. Lastly, the route segments for ROIs surveillance are connected by a path planning algorithm named the sampling-based sparse A* search (SSAS) algorithm. Simulation experiments in real scenarios demonstrate that the proposed sensor-oriented path planner can improve the reconnaissance performance of lightweight UAV SAR greatly compared with the conventional zigzag path planner.

  14. Sensor-Oriented Path Planning for Multiregion Surveillance with a Single Lightweight UAV SAR

    Science.gov (United States)

    Li, Jincheng; Chen, Jie; Wang, Pengbo; Li, Chunsheng

    2018-01-01

    In the surveillance of interested regions by unmanned aerial vehicle (UAV), system performance relies greatly on the motion control strategy of the UAV and the operation characteristics of the onboard sensors. This paper investigates the 2D path planning problem for the lightweight UAV synthetic aperture radar (SAR) system in an environment of multiple regions of interest (ROIs), the sizes of which are comparable to the radar swath width. Taking into account the special requirements of the SAR system on the motion of the platform, we model path planning for UAV SAR as a constrained multiobjective optimization problem (MOP). Based on the fact that the UAV route can be designed in the map image, an image-based path planner is proposed in this paper. First, the neighboring ROIs are merged by the morphological operation. Then, the parts of routes for data collection of the ROIs can be located according to the geometric features of the ROIs and the observation geometry of UAV SAR. Lastly, the route segments for ROIs surveillance are connected by a path planning algorithm named the sampling-based sparse A* search (SSAS) algorithm. Simulation experiments in real scenarios demonstrate that the proposed sensor-oriented path planner can improve the reconnaissance performance of lightweight UAV SAR greatly compared with the conventional zigzag path planner. PMID:29439447

  15. Public Drug Plan Coverage for Children Across Canada: A Portrait of Too Many Colours

    Science.gov (United States)

    Ungar, Wendy J; Witkos, Maciej

    2005-01-01

    Background: As debate continues regarding pharmacare in Canada, little discussion has addressed appropriate drug plan coverage for vulnerable populations, such as children. The primary objective of this study was to determine the extent of medication coverage for children in publicly administered programs in each province across Canada. Methods: Data were collected on provincial, territorial and federal government drug plans, and 2003 formulary updates were obtained. A simulation model was constructed to demonstrate costs to a low-income family with an asthmatic child in each province. Programs were compared descriptively. The extent of interprovincial variation in 2003 formulary approvals was summarized statistically. Results: There was 39% variation between provinces with respect to 2003 formulary approvals (chi-square p Canada, only 8% of 2003 formulary approvals were indicated primarily for paediatric conditions. In the simulation model, costs were less than or equal to 3% of household income in provinces with plans for low-income families, catastrophic costs (Ontario) or for the population. Families who failed to qualify for low income plans or who resided in New Brunswick or Newfoundland faced costs up to 7% of household income. Interpretation: With regard to pharmaceutical benefits for children, provincial drug programs vary considerably in terms of whom they cover, what drugs are covered and how much subscribers must pay out of pocket. Unlike seniors and social assistance recipients, the provinces do not agree on the importance of providing comprehensive coverage for all children. For many Canadian children, significant financial barriers exist to medication access. PMID:19308106

  16. A Dynamic Bioinspired Neural Network Based Real-Time Path Planning Method for Autonomous Underwater Vehicles.

    Science.gov (United States)

    Ni, Jianjun; Wu, Liuying; Shi, Pengfei; Yang, Simon X

    2017-01-01

    Real-time path planning for autonomous underwater vehicle (AUV) is a very difficult and challenging task. Bioinspired neural network (BINN) has been used to deal with this problem for its many distinct advantages: that is, no learning process is needed and realization is also easy. However, there are some shortcomings when BINN is applied to AUV path planning in a three-dimensional (3D) unknown environment, including complex computing problem when the environment is very large and repeated path problem when the size of obstacles is bigger than the detection range of sensors. To deal with these problems, an improved dynamic BINN is proposed in this paper. In this proposed method, the AUV is regarded as the core of the BINN and the size of the BINN is based on the detection range of sensors. Then the BINN will move with the AUV and the computing could be reduced. A virtual target is proposed in the path planning method to ensure that the AUV can move to the real target effectively and avoid big-size obstacles automatically. Furthermore, a target attractor concept is introduced to improve the computing efficiency of neural activities. Finally, some experiments are conducted under various 3D underwater environments. The experimental results show that the proposed BINN based method can deal with the real-time path planning problem for AUV efficiently.

  17. Research on Navigation Path Planning for An Underground Load Haul Dump

    Directory of Open Access Journals (Sweden)

    Qi Yulong

    2015-11-01

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

  18. Spine stereotactic body radiation therapy plans: Achieving dose coverage, conformity, and dose falloff

    International Nuclear Information System (INIS)

    Hong, Linda X.; Shankar, Viswanathan; Shen, Jin; Kuo, Hsiang-Chi; Mynampati, Dinesh; Yaparpalvi, Ravindra; Goddard, Lee; Basavatia, Amar; Fox, Jana; Garg, Madhur; Kalnicki, Shalom; Tomé, Wolfgang A.

    2015-01-01

    We report our experience of establishing planning objectives to achieve dose coverage, conformity, and dose falloff for spine stereotactic body radiation therapy (SBRT) plans. Patients with spine lesions were treated using SBRT in our institution since September 2009. Since September 2011, we established the following planning objectives for our SBRT spine plans in addition to the cord dose constraints: (1) dose coverage—prescription dose (PD) to cover at least 95% planning target volume (PTV) and 90% PD to cover at least 99% PTV; (2) conformity index (CI)—ratio of prescription isodose volume (PIV) to the PTV < 1.2; (3) dose falloff—ratio of 50% PIV to the PTV (R 50% ); (4) and maximum dose in percentage of PD at 2 cm from PTV in any direction (D 2cm ) to follow Radiation Therapy Oncology Group (RTOG) 0915. We have retrospectively reviewed 66 separate spine lesions treated between September 2009 and December 2012 (31 treated before September 2011 [group 1] and 35 treated after [group 2]). The χ 2 test was used to examine the difference in parameters between groups. The PTV V 100% PD ≥ 95% objective was met in 29.0% of group 1 vs 91.4% of group 2 (p < 0.01) plans. The PTV V 90% PD ≥ 99% objective was met in 38.7% of group 1 vs 88.6% of group 2 (p < 0.01) plans. Overall, 4 plans in group 1 had CI > 1.2 vs none in group 2 (p = 0.04). For D 2cm , 48.3% plans yielded a minor violation of the objectives and 16.1% a major violation for group 1, whereas 17.1% exhibited a minor violation and 2.9% a major violation for group 2 (p < 0.01). Spine SBRT plans can be improved on dose coverage, conformity, and dose falloff employing a combination of RTOG spine and lung SBRT protocol planning objectives

  19. Evolutionistic or revolutionary paths? A PACS maturity model for strategic situational planning.

    Science.gov (United States)

    van de Wetering, Rogier; Batenburg, Ronald; Lederman, Reeva

    2010-07-01

    While many hospitals are re-evaluating their current Picture Archiving and Communication System (PACS), few have a mature strategy for PACS deployment. Furthermore, strategies for implementation, strategic and situational planning methods for the evolution of PACS maturity are scarce in the scientific literature. Consequently, in this paper we propose a strategic planning method for PACS deployment. This method builds upon a PACS maturity model (PMM), based on the elaboration of the strategic alignment concept and the maturity growth path concept previously developed in the PACS domain. First, we review the literature on strategic planning for information systems and information technology and PACS maturity. Secondly, the PMM is extended by applying four different strategic perspectives of the Strategic Alignment Framework whereupon two types of growth paths (evolutionistic and revolutionary) are applied that focus on a roadmap for PMM. This roadmap builds a path to get from one level of maturity and evolve to the next. An extended method for PACS strategic planning is developed. This method defines eight distinctive strategies for PACS strategic situational planning that allow decision-makers in hospitals to decide which approach best suits their hospitals' current situation and future ambition and what in principle is needed to evolve through the different maturity levels. The proposed method allows hospitals to strategically plan for PACS maturation. It is situational in that the required investments and activities depend on the alignment between the hospital strategy and the selected growth path. The inclusion of both strategic alignment and maturity growth path concepts make the planning method rigorous, and provide a framework for further empirical research and clinical practice.

  20. Dynamic path planning for autonomous driving on various roads with avoidance of static and moving obstacles

    Science.gov (United States)

    Hu, Xuemin; Chen, Long; Tang, Bo; Cao, Dongpu; He, Haibo

    2018-02-01

    This paper presents a real-time dynamic path planning method for autonomous driving that avoids both static and moving obstacles. The proposed path planning method determines not only an optimal path, but also the appropriate acceleration and speed for a vehicle. In this method, we first construct a center line from a set of predefined waypoints, which are usually obtained from a lane-level map. A series of path candidates are generated by the arc length and offset to the center line in the s - ρ coordinate system. Then, all of these candidates are converted into Cartesian coordinates. The optimal path is selected considering the total cost of static safety, comfortability, and dynamic safety; meanwhile, the appropriate acceleration and speed for the optimal path are also identified. Various types of roads, including single-lane roads and multi-lane roads with static and moving obstacles, are designed to test the proposed method. The simulation results demonstrate the effectiveness of the proposed method, and indicate its wide practical application to autonomous driving.

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

    Science.gov (United States)

    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.

  2. Design and performance analysis of global path planning techniques for autonomous mobile robots in grid environments

    Directory of Open Access Journals (Sweden)

    Imen Chaari

    2017-03-01

    Full Text Available This article presents the results of the 2-year iroboapp research project that aims at devising path planning algorithms for large grid maps with much faster execution times while tolerating very small slacks with respect to the optimal path. We investigated both exact and heuristic methods. We contributed with the design, analysis, evaluation, implementation and experimentation of several algorithms for grid map path planning for both exact and heuristic methods. We also designed an innovative algorithm called relaxed A-star that has linear complexity with relaxed constraints, which provides near-optimal solutions with an extremely reduced execution time as compared to A-star. We evaluated the performance of the different algorithms and concluded that relaxed A-star is the best path planner as it provides a good trade-off among all the metrics, but we noticed that heuristic methods have good features that can be exploited to improve the solution of the relaxed exact method. This led us to design new hybrid algorithms that combine our relaxed A-star with heuristic methods which improve the solution quality of relaxed A-star at the cost of slightly higher execution time, while remaining much faster than A* for large-scale problems. Finally, we demonstrate how to integrate the relaxed A-star algorithm in the robot operating system as a global path planner and show that it outperforms its default path planner with an execution time 38% faster on average.

  3. Can Plan Recommendations Improve the Coverage Decisions of Vulnerable Populations in Health Insurance Marketplaces?

    Science.gov (United States)

    Barnes, Andrew J; Hanoch, Yaniv; Rice, Thomas

    2016-01-01

    The Affordable Care Act's marketplaces present an important opportunity for expanding coverage but consumers face enormous challenges in navigating through enrollment and re-enrollment. We tested the effectiveness of a behaviorally informed policy tool--plan recommendations--in improving marketplace decisions. Data were gathered from a community sample of 656 lower-income, minority, rural residents of Virginia. We conducted an incentive-compatible, computer-based experiment using a hypothetical marketplace like the one consumers face in the federally-facilitated marketplaces, and examined their decision quality. Participants were randomly assigned to a control condition or three types of plan recommendations: social normative, physician, and government. For participants randomized to a plan recommendation condition, the plan that maximized expected earnings, and minimized total expected annual health care costs, was recommended. Primary data were gathered using an online choice experiment and questionnaire. Plan recommendations resulted in a 21 percentage point increase in the probability of choosing the earnings maximizing plan, after controlling for participant characteristics. Two conditions, government or providers recommending the lowest cost plan, resulted in plan choices that lowered annual costs compared to marketplaces where no recommendations were made. As millions of adults grapple with choosing plans in marketplaces and whether to switch plans during open enrollment, it is time to consider marketplace redesigns and leverage insights from the behavioral sciences to facilitate consumers' decisions.

  4. Can Plan Recommendations Improve the Coverage Decisions of Vulnerable Populations in Health Insurance Marketplaces?

    Directory of Open Access Journals (Sweden)

    Andrew J Barnes

    Full Text Available The Affordable Care Act's marketplaces present an important opportunity for expanding coverage but consumers face enormous challenges in navigating through enrollment and re-enrollment. We tested the effectiveness of a behaviorally informed policy tool--plan recommendations--in improving marketplace decisions.Data were gathered from a community sample of 656 lower-income, minority, rural residents of Virginia.We conducted an incentive-compatible, computer-based experiment using a hypothetical marketplace like the one consumers face in the federally-facilitated marketplaces, and examined their decision quality. Participants were randomly assigned to a control condition or three types of plan recommendations: social normative, physician, and government. For participants randomized to a plan recommendation condition, the plan that maximized expected earnings, and minimized total expected annual health care costs, was recommended.Primary data were gathered using an online choice experiment and questionnaire.Plan recommendations resulted in a 21 percentage point increase in the probability of choosing the earnings maximizing plan, after controlling for participant characteristics. Two conditions, government or providers recommending the lowest cost plan, resulted in plan choices that lowered annual costs compared to marketplaces where no recommendations were made.As millions of adults grapple with choosing plans in marketplaces and whether to switch plans during open enrollment, it is time to consider marketplace redesigns and leverage insights from the behavioral sciences to facilitate consumers' decisions.

  5. Planning of optimal work path for minimizing exposure dose during radiation work in radwaste storage

    International Nuclear Information System (INIS)

    Kim, Yoon Hyuk; Park, Won Man; Kim, Kyung Soo; Whang, Joo Ho

    2005-01-01

    Since the safety of nuclear power plant has been becoming a big social issue, the exposure dose of radiation for workers has been one of the important factors concerning the safety problem. The existing calculation methods of radiation dose used in the planning of radiation work assume that dose rate dose not depend on the location within a work space, thus the variation of exposure dose by different work path is not considered. In this study, a modified numerical method was presented to estimate the exposure dose during radiation work in radwaste storage considering the effects of the distance between a worker and sources. And a new numerical algorithm was suggested to search the optimal work path minimizing the exposure dose in pre-defined work space with given radiation sources. Finally, a virtual work simulation program was developed to visualize the exposure dose of radiation during radiation works in radwaste storage and provide the capability of simulation for work planning. As a numerical example, a test radiation work was simulated under given space and two radiation sources, and the suggested optimal work path was compared with three predefined work paths. The optimal work path obtained in the study could reduce the exposure dose for the given test work. Based on the results, the developed numerical method and simulation program could be useful tools in the planning of radiation work

  6. PSO-Based Robot Path Planning for Multisurvivor Rescue in Limited Survival Time

    Directory of Open Access Journals (Sweden)

    N. Geng

    2014-01-01

    Full Text Available Since the strength of a trapped person often declines with time in urgent and dangerous circumstances, adopting a robot to rescue as many survivors as possible in limited time is of considerable significance. However, as one key issue in robot navigation, how to plan an optimal rescue path of a robot has not yet been fully solved. This paper studies robot path planning for multisurvivor rescue in limited survival time using a representative heuristic, particle swarm optimization (PSO. First, the robot path planning problem including multiple survivors is formulated as a discrete optimization one with high constraint, where the number of rescued persons is taken as the unique objective function, and the strength of a trapped person is used to constrain the feasibility of a path. Then, a new integer PSO algorithm is presented to solve the mathematical model, and several new operations, such as the update of a particle, the insertion and inversion operators, and the rapidly local search method, are incorporated into the proposed algorithm to improve its effectiveness. Finally, the simulation results demonstrate the capacity of our method in generating optimal paths with high quality.

  7. Change in challenging times: a plan for extending and improving health coverage.

    Science.gov (United States)

    Lambrew, Jeanne M; Podesta, John D; Shaw, Teresa L

    2005-01-01

    Some speculate that Americans are neither politically capable of nor morally committed to solving the health system problems. We disagree. We propose a plan that insures all and improves the value and cost-effectiveness of health care by knitting together employer-sponsored insurance and Medicaid; promoting prevention, research, and information technology; and financing its investments through a dedicated value-added tax. By prioritizing practicality, fairness, and responsibility, the plan aims to avoid ideological battles and prevent fear of major change. By emphasizing the moral imperative for change, especially relative to other options on the policy agenda, it aims to create momentum for expanding and improving health coverage for all.

  8. Family Planning in the Context of Latin America's Universal Health Coverage Agenda.

    Science.gov (United States)

    Fagan, Thomas; Dutta, Arin; Rosen, James; Olivetti, Agathe; Klein, Kate

    2017-09-27

    Countries in Latin America and the Caribbean (LAC) have substantially improved access to family planning over the past 50 years. Many have also recently adopted explicit declarations of universal rights to health and universal health coverage (UHC) and have begun implementing UHC-oriented health financing schemes. These schemes will have important implications for the sustainability and further growth of family planning programs throughout the region. We examined the status of contraceptive methods in major health delivery and financing schemes in 9 LAC countries. Using a set of 37 indicators on family planning coverage, family planning financing, health financing, and family planning inclusion in UHC-oriented schemes, we conducted a desk review of secondary sources, including population surveys, health financing assessments, insurance enrollment reports, and unit cost estimates, and interviewed in-country experts. Findings: Although the modern contraceptive prevalence rate (mCPR) has continued to increase in the majority of LAC countries, substantial disparities in access for marginalized groups remain. On average, mCPR is 20% lower among indigenous women than the general population, 5% lower among uninsured women than insured, and 7% lower among the poorest women than the wealthiest. Among the poorest quintile of women, insured women had an mCPR 16.5 percentage points higher than that of uninsured women, suggesting that expansion of insurance coverage is associated with increased family planning access and use. In the high- and upper-middle-income countries we reviewed, all modern contraceptive methods are typically available through the social health insurance schemes that cover a majority of the population. However, in low- and lower-middle-income countries, despite free provision of most family planning services in public health facilities, stock-outs and implicit rationing present substantial barriers that prevent clients from accessing their preferred method

  9. Current-Sensitive Path Planning for an Underactuated Free-Floating Ocean Sensorweb

    Science.gov (United States)

    Dahl, Kristen P.; Thompson, David R.; McLaren, David; Chao, Yi; Chien, Steve

    2011-01-01

    This work investigates multi-agent path planning in strong, dynamic currents using thousands of highly under-actuated vehicles. We address the specific task of path planning for a global network of ocean-observing floats. These submersibles are typified by the Argo global network consisting of over 3000 sensor platforms. They can control their buoyancy to float at depth for data collection or rise to the surface for satellite communications. Currently, floats drift at a constant depth regardless of the local currents. However, accurate current forecasts have become available which present the possibility of intentionally controlling floats' motion by dynamically commanding them to linger at different depths. This project explores the use of these current predictions to direct float networks to some desired final formation or position. It presents multiple algorithms for such path optimization and demonstrates their advantage over the standard approach of constant-depth drifting.

  10. Interactive Learning Environment for Bio-Inspired Optimization Algorithms for UAV Path Planning

    Science.gov (United States)

    Duan, Haibin; Li, Pei; Shi, Yuhui; Zhang, Xiangyin; Sun, Changhao

    2015-01-01

    This paper describes the development of BOLE, a MATLAB-based interactive learning environment, that facilitates the process of learning bio-inspired optimization algorithms, and that is dedicated exclusively to unmanned aerial vehicle path planning. As a complement to conventional teaching methods, BOLE is designed to help students consolidate the…

  11. Hybrid path planning for non-holonomic autonomous vehicles: An experimental evaluation

    NARCIS (Netherlands)

    Esposto, F.; Goos, J.; Teerhuis, A.; Alirezaei, M.

    2017-01-01

    Path planning of an autonomous vehicle as a non-holonomic system is an essential part for many automated driving applications. Parking a car into a parking lot and maneuvering it through a narrow corridor would be a common driving scenarios in an urban environment. In this study a hybrid approach

  12. Solving the empty space problem in robot path planning by mathematical morphology

    NARCIS (Netherlands)

    Roerdink, J.B.T.M.

    1993-01-01

    In this paper we formulate a morphological approach to path planning problems, in particular with respect to the empty­-space problem, that is, the question of finding the allowed states for an object, moving in a space with obstacles. Our approach is based upon a recent generalization of

  13. Energy-Aware Path Planning for UAS Persistent Sampling and Surveillance

    Science.gov (United States)

    Shaw-Cortez, Wenceslao

    The focus of this work is to develop an energy-aware path planning algorithm that maximizes UAS endurance, while performing sampling and surveillance missions in a known, stationary wind environment. The energy-aware aspect is specifically tailored to extract energy from the wind to reduce thrust use, thereby increasing aircraft endurance. Wind energy extraction is performed by static soaring and dynamic soaring. Static soaring involves using upward wind currents to increase altitude and potential energy. Dynamic soaring involves taking advantage of wind gradients to exchange potential and kinetic energy. The path planning algorithm developed in this work uses optimization to combine these soaring trajectories with the overarching sampling and surveillance mission. The path planning algorithm uses a simplified aircraft model to tractably optimize soaring trajectories. This aircraft model is presented and along with the derivation of the equations of motion. A nonlinear program is used to create the soaring trajectories based on a given optimization problem. This optimization problem is defined using a heuristic decision tree, which defines appropriate problems given a sampling and surveillance mission and a wind model. Simulations are performed to assess the path planning algorithm. The results are used to identify properties of soaring trajectories as well as to determine what wind conditions support minimal thrust soaring. Additional results show how the path planning algorithm can be tuned between maximizing aircraft endurance and performing the sampling and surveillance mission. A means of trajectory stitching is demonstrated to show how the periodic soaring segments can be combined together to provide a full solution to an infinite/long horizon problem.

  14. Planning Coverage Campaigns for Mission Design and Analysis: CLASP for DESDynl

    Science.gov (United States)

    Knight, Russell L.; McLaren, David A.; Hu, Steven

    2013-01-01

    Mission design and analysis presents challenges in that almost all variables are in constant flux, yet the goal is to achieve an acceptable level of performance against a concept of operations, which might also be in flux. To increase responsiveness, automated planning tools are used that allow for the continual modification of spacecraft, ground system, staffing, and concept of operations, while returning metrics that are important to mission evaluation, such as area covered, peak memory usage, and peak data throughput. This approach was applied to the DESDynl mission design using the CLASP planning system, but since this adaptation, many techniques have changed under the hood for CLASP, and the DESDynl mission concept has undergone drastic changes. The software produces mission evaluation products, such as memory highwater marks, coverage percentages, given a mission design in the form of coverage targets, concept of operations, spacecraft parameters, and orbital parameters. It tries to overcome the lack of fidelity and timeliness of mission requirements coverage analysis during mission design. Previous techniques primarily use Excel in ad hoc fashion to approximate key factors in mission performance, often falling victim to overgeneralizations necessary in such an adaptation. The new program allows designers to faithfully represent their mission designs quickly, and get more accurate results just as quickly.

  15. Methodology for using root locus technique for mobile robots path planning

    Directory of Open Access Journals (Sweden)

    Mario Ricardo Arbulú Saavedra

    2015-11-01

    Full Text Available This paper shows the analysis and the implementation methodology of the technique of dynamic systems roots location used in free-obstacle path planning for mobile robots. First of all, the analysis and morphologic behavior identification of the paths depending on roots location in complex plane are performed, where paths type and their attraction and repulsion features in the presence of other roots similarly to the obtained with artificial potential fields are identified. An implementation methodology for this technique of mobile robots path planning is proposed, starting from three different methods of roots location for obstacles in the scene. Those techniques change depending on the obstacle key points selected for roots, such as borders, crossing points with original path, center and vertices. Finally, a behavior analysis of general technique and the effectiveness of each tried method is performed, doing 20 tests for each one, obtaining a value of 65% for the selected method. Modifications and possible improvements to this methodology are also proposed.

  16. A Dynamic Hidden Forwarding Path Planning Method Based on Improved Q-Learning in SDN Environments

    Directory of Open Access Journals (Sweden)

    Yun Chen

    2018-01-01

    Full Text Available Currently, many methods are available to improve the target network’s security. The vast majority of them cannot obtain an optimal attack path and interdict it dynamically and conveniently. Almost all defense strategies aim to repair known vulnerabilities or limit services in target network to improve security of network. These methods cannot response to the attacks in real-time because sometimes they need to wait for manufacturers releasing corresponding countermeasures to repair vulnerabilities. In this paper, we propose an improved Q-learning algorithm to plan an optimal attack path directly and automatically. Based on this path, we use software-defined network (SDN to adjust routing paths and create hidden forwarding paths dynamically to filter vicious attack requests. Compared to other machine learning algorithms, Q-learning only needs to input the target state to its agents, which can avoid early complex training process. We improve Q-learning algorithm in two aspects. First, a reward function based on the weights of hosts and attack success rates of vulnerabilities is proposed, which can adapt to different network topologies precisely. Second, we remove the actions and merge them into every state that reduces complexity from O(N3 to O(N2. In experiments, after deploying hidden forwarding paths, the security of target network is boosted significantly without having to repair network vulnerabilities immediately.

  17. The Robot Path Planning Based on Improved Artificial Fish Swarm Algorithm

    Directory of Open Access Journals (Sweden)

    Yi Zhang

    2016-01-01

    Full Text Available Path planning is critical to the efficiency and fidelity of robot navigation. The solution of robot path planning is to seek a collision-free and the shortest path from the start node to target node. In this paper, we propose a new improved artificial fish swarm algorithm (IAFSA to process the mobile robot path planning problem in a real environment. In IAFSA, an attenuation function is introduced to improve the visual of standard AFSA and get the balance of global search and local search; also, an adaptive operator is introduced to enhance the adaptive ability of step. Besides, a concept of inertia weight factor is proposed in IAFSA inspired by PSO intelligence algorithm to improve the convergence rate and accuracy of IAFSA. Five unconstrained optimization test functions are given to illustrate the strong searching ability and ideal convergence of IAFSA. Finally, the ROS (robot operation system based experiment is carried out on a Pioneer 3-DX mobile robot; the experiment results also show the superiority of IAFSA.

  18. Task Assignment and Path Planning for Multiple Autonomous Underwater Vehicles Using 3D Dubins Curves †.

    Science.gov (United States)

    Cai, Wenyu; Zhang, Meiyan; Zheng, Yahong Rosa

    2017-07-11

    This paper investigates the task assignment and path planning problem for multiple AUVs in three dimensional (3D) underwater wireless sensor networks where nonholonomic motion constraints of underwater AUVs in 3D space are considered. The multi-target task assignment and path planning problem is modeled by the Multiple Traveling Sales Person (MTSP) problem and the Genetic Algorithm (GA) is used to solve the MTSP problem with Euclidean distance as the cost function and the Tour Hop Balance (THB) or Tour Length Balance (TLB) constraints as the stop criterion. The resulting tour sequences are mapped to 2D Dubins curves in the X - Y plane, and then interpolated linearly to obtain the Z coordinates. We demonstrate that the linear interpolation fails to achieve G 1 continuity in the 3D Dubins path for multiple targets. Therefore, the interpolated 3D Dubins curves are checked against the AUV dynamics constraint and the ones satisfying the constraint are accepted to finalize the 3D Dubins curve selection. Simulation results demonstrate that the integration of the 3D Dubins curve with the MTSP model is successful and effective for solving the 3D target assignment and path planning problem.

  19. TP-Space RRT – Kinematic Path Planning of Non-Holonomic Any-Shape Vehicles

    Directory of Open Access Journals (Sweden)

    Jose Luis Blanco

    2015-05-01

    Full Text Available The autonomous navigation of vehicles typically combines two kinds of methods: a path is first planned, and then the robot is driven by a local obstacle-avoidance controller. The present work, which focuses on path planning, proposes an extension to the well-known rapidly-exploring random tree (RRT algorithm to allow its integration with a trajectory parameter-space (TP-space as an efficient method to detect collision-free, kinematically-feasible paths for arbitrarily-shaped vehicles. In contrast to original RRT, this proposal generates navigation trees, with poses as nodes, whose edges are all kinematically-feasible paths, suitable to being accurately followed by vehicles driven by pure reactive algorithms. Initial experiments demonstrate the suitability of the method with an Ackermann-steering vehicle model whose severe kinematic constraints cannot be obviated. An important result that sets this work apart from previous research is the finding that employing several families of potential trajectories to expand the tree, which can be done efficiently under the TP-space formalism, improves the optimality of the planned trajectories. A reference C++ implementation has been released as open-source.

  20. Path Planning Method for UUV Homing and Docking in Movement Disorders Environment

    Directory of Open Access Journals (Sweden)

    Zheping Yan

    2014-01-01

    Full Text Available Path planning method for unmanned underwater vehicles (UUV homing and docking in movement disorders environment is proposed in this paper. Firstly, cost function is proposed for path planning. Then, a novel particle swarm optimization (NPSO is proposed and applied to find the waypoint with minimum value of cost function. Then, a strategy for UUV enters into the mother vessel with a fixed angle being proposed. Finally, the test function is introduced to analyze the performance of NPSO and compare with basic particle swarm optimization (BPSO, inertia weight particle swarm optimization (LWPSO, EPSO, and time-varying acceleration coefficient (TVAC. It has turned out that, for unimodal functions, NPSO performed better searching accuracy and stability than other algorithms, and, for multimodal functions, the performance of NPSO is similar to TVAC. Then, the simulation of UUV path planning is presented, and it showed that, with the strategy proposed in this paper, UUV can dodge obstacles and threats, and search for the efficiency path.

  1. Task Assignment and Path Planning for Multiple Autonomous Underwater Vehicles Using 3D Dubins Curves †

    Directory of Open Access Journals (Sweden)

    Wenyu Cai

    2017-07-01

    Full Text Available This paper investigates the task assignment and path planning problem for multiple AUVs in three dimensional (3D underwater wireless sensor networks where nonholonomic motion constraints of underwater AUVs in 3D space are considered. The multi-target task assignment and path planning problem is modeled by the Multiple Traveling Sales Person (MTSP problem and the Genetic Algorithm (GA is used to solve the MTSP problem with Euclidean distance as the cost function and the Tour Hop Balance (THB or Tour Length Balance (TLB constraints as the stop criterion. The resulting tour sequences are mapped to 2D Dubins curves in the X − Y plane, and then interpolated linearly to obtain the Z coordinates. We demonstrate that the linear interpolation fails to achieve G 1 continuity in the 3D Dubins path for multiple targets. Therefore, the interpolated 3D Dubins curves are checked against the AUV dynamics constraint and the ones satisfying the constraint are accepted to finalize the 3D Dubins curve selection. Simulation results demonstrate that the integration of the 3D Dubins curve with the MTSP model is successful and effective for solving the 3D target assignment and path planning problem.

  2. Disordered and Multiple Destinations Path Planning Methods for Mobile Robot in Dynamic Environment

    Directory of Open Access Journals (Sweden)

    Yong-feng Dong

    2016-01-01

    Full Text Available In the smart home environment, aiming at the disordered and multiple destinations path planning, the sequencing rule is proposed to determine the order of destinations. Within each branching process, the initial feasible path set is generated according to the law of attractive destination. A sinusoidal adaptive genetic algorithm is adopted. It can calculate the crossover probability and mutation probability adaptively changing with environment at any time. According to the cultural-genetic algorithm, it introduces the concept of reducing turns by parallelogram and reducing length by triangle in the belief space, which can improve the quality of population. And the fallback strategy can help to jump out of the “U” trap effectively. The algorithm analyses the virtual collision in dynamic environment with obstacles. According to the different collision types, different strategies are executed to avoid obstacles. The experimental results show that cultural-genetic algorithm can overcome the problems of premature and convergence of original algorithm effectively. It can avoid getting into the local optimum. And it is more effective for mobile robot path planning. Even in complex environment with static and dynamic obstacles, it can avoid collision safely and plan an optimal path rapidly at the same time.

  3. Task path planning, scheduling and learning for free-ranging robot systems

    Science.gov (United States)

    Wakefield, G. Steve

    1987-01-01

    The development of robotics applications for space operations is often restricted by the limited movement available to guided robots. Free ranging robots can offer greater flexibility than physically guided robots in these applications. Presented here is an object oriented approach to path planning and task scheduling for free-ranging robots that allows the dynamic determination of paths based on the current environment. The system also provides task learning for repetitive jobs. This approach provides a basis for the design of free-ranging robot systems which are adaptable to various environments and tasks.

  4. PRELIMINARY PROJECT PLAN FOR LANSCE INTEGRATED FLIGHT PATHS 11A, 11B, 12, and 13

    International Nuclear Information System (INIS)

    Bultman, D. H.; Weinacht, D.

    2000-01-01

    This Preliminary Project Plan Summarizes the Technical, Cost, and Schedule baselines for an integrated approach to developing several flight paths at the Manual Lujan Jr. Neutron Scattering Center at the Los Alamos Neutron Science Center. For example, the cost estimate is intended to serve only as a rough order of magnitude assessment of the cost that might be incurred as the flight paths are developed. Further refinement of the requirements and interfaces for each beamline will permit additional refinement and confidence in the accuracy of all three baselines (Technical, Cost, Schedule)

  5. Pose estimation-based path planning for a tracked mobile robot traversing uneven terrains

    OpenAIRE

    Jun , Jae-Yun; Saut , Jean-Philippe; Benamar , Faïz

    2015-01-01

    International audience; A novel path-planning algorithm is proposed for a tracked mobile robot to traverse uneven terrains, which can efficiently search for stability sub-optimal paths. This algorithm consists of combining two RRT-like algorithms (the Transition-based RRT (T-RRT) and the Dynamic-Domain RRT (DD-RRT) algorithms) bidirectionally and of representing the robot-terrain interaction with the robot’s quasi-static tip-over stability measure (assuming that the robot traverses uneven ter...

  6. Spine stereotactic body radiation therapy plans: Achieving dose coverage, conformity, and dose falloff

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Linda X., E-mail: lhong0812@gmail.com [Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY (United States); Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, NY (United States); Shankar, Viswanathan [Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY (United States); Shen, Jin [Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY (United States); Kuo, Hsiang-Chi [Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY (United States); Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, NY (United States); Mynampati, Dinesh [Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY (United States); Yaparpalvi, Ravindra [Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY (United States); Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, NY (United States); Goddard, Lee [Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY (United States); Basavatia, Amar; Fox, Jana; Garg, Madhur; Kalnicki, Shalom; Tomé, Wolfgang A. [Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY (United States); Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, NY (United States)

    2015-10-01

    We report our experience of establishing planning objectives to achieve dose coverage, conformity, and dose falloff for spine stereotactic body radiation therapy (SBRT) plans. Patients with spine lesions were treated using SBRT in our institution since September 2009. Since September 2011, we established the following planning objectives for our SBRT spine plans in addition to the cord dose constraints: (1) dose coverage—prescription dose (PD) to cover at least 95% planning target volume (PTV) and 90% PD to cover at least 99% PTV; (2) conformity index (CI)—ratio of prescription isodose volume (PIV) to the PTV < 1.2; (3) dose falloff—ratio of 50% PIV to the PTV (R{sub 50%}); (4) and maximum dose in percentage of PD at 2 cm from PTV in any direction (D{sub 2cm}) to follow Radiation Therapy Oncology Group (RTOG) 0915. We have retrospectively reviewed 66 separate spine lesions treated between September 2009 and December 2012 (31 treated before September 2011 [group 1] and 35 treated after [group 2]). The χ{sup 2} test was used to examine the difference in parameters between groups. The PTV V{sub 100%} {sub PD} ≥ 95% objective was met in 29.0% of group 1 vs 91.4% of group 2 (p < 0.01) plans. The PTV V{sub 90%} {sub PD} ≥ 99% objective was met in 38.7% of group 1 vs 88.6% of group 2 (p < 0.01) plans. Overall, 4 plans in group 1 had CI > 1.2 vs none in group 2 (p = 0.04). For D{sub 2cm}, 48.3% plans yielded a minor violation of the objectives and 16.1% a major violation for group 1, whereas 17.1% exhibited a minor violation and 2.9% a major violation for group 2 (p < 0.01). Spine SBRT plans can be improved on dose coverage, conformity, and dose falloff employing a combination of RTOG spine and lung SBRT protocol planning objectives.

  7. Path Planning of Free-Floating Robot in Cartesian Space Using Direct Kinematics

    Directory of Open Access Journals (Sweden)

    Wenfu Xu

    2007-03-01

    Full Text Available Dynamic singularities make it difficult to plan the Cartesian path of free-floating robot. In order to avoid its effect, the direct kinematic equations are used for path planning in the paper. Here, the joint position, rate and acceleration are bounded. Firstly, the joint trajectories are parameterized by polynomial or sinusoidal functions. And the two parametric functions are compared in details. It is the first contribution of the paper that polynomial functions can be used when the joint angles are limited(In the similar work of other researchers, only sinusoidla functions could be used. Secondly, the joint functions are normalized and the system of equations about the parameters is established by integrating the differential kinematics equations. Normalization is another contribution of the paper. After normalization, the boundary of the parameters is determined beforehand, and the general criterion to assign the initial guess of the unknown parameters is supplied. The criterion is independent on the planning conditions such as the total time tf. Finally, the parametes are solved by the iterative Newtonian method. Modification of tf may not result in the recalculation of the parameters. Simulation results verify the path planning method.

  8. Path Planning of Free-Floating Robot in Cartesian Space Using Direct Kinematics

    Directory of Open Access Journals (Sweden)

    Wenfu Xu

    2008-11-01

    Full Text Available Dynamic singularities make it difficult to plan the Cartesian path of freefloating robot. In order to avoid its effect, the direct kinematic equations are used for path planning in the paper. Here, the joint position, rate and acceleration are bounded. Firstly, the joint trajectories are parameterized by polynomial or sinusoidal functions. And the two parametric functions are compared in details. It is the first contribution of the paper that polynomial functions can be used when the joint angles are limited(In the similar work of other researchers, only sinusoidla functions could be used. Secondly, the joint functions are normalized and the system of equations about the parameters is established by integrating the differential kinematics equations. Normalization is another contribution of the paper. After normalization, the boundary of the parameters is determined beforehand, and the general criterion to assign the initial guess of the unknown parameters is supplied. The criterion is independent on the planning conditions such as the total time tf. Finally, the parametes are solved by the iterative Newtonian method. Modification of tf may not result in the recalculation of the parameters. Simulation results verify the path planning method.

  9. Mobile-robot navigation with complete coverage of unstructured environments

    OpenAIRE

    García Armada, Elena; González de Santos, Pablo

    2004-01-01

    There are some mobile-robot applications that require the complete coverage of an unstructured environment. Examples are humanitarian de-mining and floor-cleaning tasks. A complete-coverage algorithm is then used, a path-planning technique that allows the robot to pass over all points in the environment, avoiding unknown obstacles. Different coverage algorithms exist, but they fail working in unstructured environments. This paper details a complete-coverage algorithm for unstructured environm...

  10. A novel algorithm for solving optimal path planning problems based on parametrization method and fuzzy aggregation

    International Nuclear Information System (INIS)

    Zamirian, M.; Kamyad, A.V.; Farahi, M.H.

    2009-01-01

    In this Letter a new approach for solving optimal path planning problems for a single rigid and free moving object in a two and three dimensional space in the presence of stationary or moving obstacles is presented. In this approach the path planning problems have some incompatible objectives such as the length of path that must be minimized, the distance between the path and obstacles that must be maximized and etc., then a multi-objective dynamic optimization problem (MODOP) is achieved. Considering the imprecise nature of decision maker's (DM) judgment, these multiple objectives are viewed as fuzzy variables. By determining intervals for the values of these fuzzy variables, flexible monotonic decreasing or increasing membership functions are determined as the degrees of satisfaction of these fuzzy variables on their intervals. Then, the optimal path planning policy is searched by maximizing the aggregated fuzzy decision values, resulting in a fuzzy multi-objective dynamic optimization problem (FMODOP). Using a suitable t-norm, the FMODOP is converted into a non-linear dynamic optimization problem (NLDOP). By using parametrization method and some calculations, the NLDOP is converted into the sequence of conventional non-linear programming problems (NLPP). It is proved that the solution of this sequence of the NLPPs tends to a Pareto optimal solution which, among other Pareto optimal solutions, has the best satisfaction of DM for the MODOP. Finally, the above procedure as a novel algorithm integrating parametrization method and fuzzy aggregation to solve the MODOP is proposed. Efficiency of our approach is confirmed by some numerical examples.

  11. Evaluation of a New Backtrack Free Path Planning Algorithm for Manipulators

    Science.gov (United States)

    Islam, Md. Nazrul; Tamura, Shinsuke; Murata, Tomonari; Yanase, Tatsuro

    This paper evaluates a newly proposed backtrack free path planning algorithm (BFA) for manipulators. BFA is an exact algorithm, i.e. it is resolution complete. Different from existing resolution complete algorithms, its computation time and memory space are proportional to the number of arms. Therefore paths can be calculated within practical and predetermined time even for manipulators with many arms, and it becomes possible to plan complicated motions of multi-arm manipulators in fully automated environments. The performance of BFA is evaluated for 2-dimensional environments while changing the number of arms and obstacle placements. Its performance under locus and attitude constraints is also evaluated. Evaluation results show that the computation volume of the algorithm is almost the same as the theoretical one, i.e. it increases linearly with the number of arms even in complicated environments. Moreover BFA achieves the constant performance independent of environments.

  12. Research and Implementation of Robot Path Planning Based onVSLAM

    Directory of Open Access Journals (Sweden)

    Wang Zi-Qiang

    2018-01-01

    Full Text Available In order to solve the problem of warehouse logistics robots planpath in different scenes, this paper proposes a method based on visual simultaneous localization and mapping (VSLAM to build grid map of different scenes and use A* algorithm to plan path on the grid map. Firstly, we use VSLAMto reconstruct the environment in three-dimensionally. Secondly, based on the three-dimensional environment data, we calculate the accessibility of each grid to prepare occupied grid map (OGM for terrain description. Rely on the terrain information, we use the A* algorithm to solve path planning problem. We also optimize the A* algorithm and improve algorithm efficiency. Lastly, we verify the effectiveness and reliability of the proposed method by simulation and experimental results.

  13. Optimal path planning for a mobile robot using cuckoo search algorithm

    Science.gov (United States)

    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.

  14. A Novel Path Planning for Robots Based on Rapidly-Exploring Random Tree and Particle Swarm Optimizer Algorithm

    Directory of Open Access Journals (Sweden)

    Zhou Feng

    2013-09-01

    Full Text Available A based on Rapidly-exploring Random Tree(RRT and Particle Swarm Optimizer (PSO for path planning of the robot is proposed.First the grid method is built to describe the working space of the mobile robot,then the Rapidly-exploring Random Tree algorithm is used to obtain the global navigation path,and the Particle Swarm Optimizer algorithm is adopted to get the better path.Computer experiment results demonstrate that this novel algorithm can plan an optimal path rapidly in a cluttered environment.The successful obstacle avoidance is achieved,and the model is robust and performs reliably.

  15. Task Allocation and Path Planning for Collaborative Autonomous Underwater Vehicles Operating through an Underwater Acoustic Network

    Directory of Open Access Journals (Sweden)

    Yueyue Deng

    2013-01-01

    Full Text Available Dynamic and unstructured multiple cooperative autonomous underwater vehicle (AUV missions are highly complex operations, and task allocation and path planning are made significantly more challenging under realistic underwater acoustic communication constraints. This paper presents a solution for the task allocation and path planning for multiple AUVs under marginal acoustic communication conditions: a location-aided task allocation framework (LAAF algorithm for multitarget task assignment and the grid-based multiobjective optimal programming (GMOOP mathematical model for finding an optimal vehicle command decision given a set of objectives and constraints. Both the LAAF and GMOOP algorithms are well suited in poor acoustic network condition and dynamic environment. Our research is based on an existing mobile ad hoc network underwater acoustic simulator and blind flooding routing protocol. Simulation results demonstrate that the location-aided auction strategy performs significantly better than the well-accepted auction algorithm developed by Bertsekas in terms of task-allocation time and network bandwidth consumption. We also demonstrate that the GMOOP path-planning technique provides an efficient method for executing multiobjective tasks by cooperative agents with limited communication capabilities. This is in contrast to existing multiobjective action selection methods that are limited to networks where constant, reliable communication is assumed to be available.

  16. 77 FR 8725 - Group Health Plans and Health Insurance Issuers Relating to Coverage of Preventive Services Under...

    Science.gov (United States)

    2012-02-15

    ... regulations authorizing the exemption of group health plans and group health insurance coverage sponsored by... plans and group health insurance issuers on April 16, 2012. FOR FURTHER INFORMATION CONTACT: Amy Turner... addition, information from HHS on private health insurance for consumers can be found on the CMS Web site...

  17. Path planning for persistent surveillance applications using fixed-wing unmanned aerial vehicles

    Science.gov (United States)

    Keller, James F.

    This thesis addresses coordinated path planning for fixed-wing Unmanned Aerial Vehicles (UAVs) engaged in persistent surveillance missions. While uniquely suited to this mission, fixed wing vehicles have maneuver constraints that can limit their performance in this role. Current technology vehicles are capable of long duration flight with a minimal acoustic footprint while carrying an array of cameras and sensors. Both military tactical and civilian safety applications can benefit from this technology. We make three main contributions: C1 A sequential path planner that generates a C 2 flight plan to persistently acquire a covering set of data over a user designated area of interest. The planner features the following innovations: • A path length abstraction that embeds kino-dynamic motion constraints to estimate feasible path length. • A Traveling Salesman-type planner to generate a covering set route based on the path length abstraction. • A smooth path generator that provides C 2 routes that satisfy user specified curvature constraints. C2 A set of algorithms to coordinate multiple UAVs, including mission commencement from arbitrary locations to the start of a coordinated mission and de-confliction of paths to avoid collisions with other vehicles and fixed obstacles. C3 A numerically robust toolbox of spline-based algorithms tailored for vehicle routing validated through flight test experiments on multiple platforms. A variety of tests and platforms are discussed. The algorithms presented are based on a technical approach with approximately equal emphasis on analysis, computation, dynamic simulation, and flight test experimentation. Our planner (C1) directly takes into account vehicle maneuverability and agility constraints that could otherwise render simple solutions infeasible. This is especially important when surveillance objectives elevate the importance of optimized paths. Researchers have developed a diverse range of solutions for persistent

  18. Radial polar histogram: obstacle avoidance and path planning for robotic cognition and motion control

    Science.gov (United States)

    Wang, Po-Jen; Keyawa, Nicholas R.; Euler, Craig

    2012-01-01

    In order to achieve highly accurate motion control and path planning for a mobile robot, an obstacle avoidance algorithm that provided a desired instantaneous turning radius and velocity was generated. This type of obstacle avoidance algorithm, which has been implemented in California State University Northridge's Intelligent Ground Vehicle (IGV), is known as Radial Polar Histogram (RPH). The RPH algorithm utilizes raw data in the form of a polar histogram that is read from a Laser Range Finder (LRF) and a camera. A desired open block is determined from the raw data utilizing a navigational heading and an elliptical approximation. The left and right most radii are determined from the calculated edges of the open block and provide the range of possible radial paths the IGV can travel through. In addition, the calculated obstacle edge positions allow the IGV to recognize complex obstacle arrangements and to slow down accordingly. A radial path optimization function calculates the best radial path between the left and right most radii and is sent to motion control for speed determination. Overall, the RPH algorithm allows the IGV to autonomously travel at average speeds of 3mph while avoiding all obstacles, with a processing time of approximately 10ms.

  19. Integrated flight path planning system and flight control system for unmanned helicopters.

    Science.gov (United States)

    Jan, Shau Shiun; Lin, Yu Hsiang

    2011-01-01

    This paper focuses on the design of an integrated navigation and guidance system for unmanned helicopters. The integrated navigation system comprises two systems: the Flight Path Planning System (FPPS) and the Flight Control System (FCS). The FPPS finds the shortest flight path by the A-Star (A*) algorithm in an adaptive manner for different flight conditions, and the FPPS can add a forbidden zone to stop the unmanned helicopter from crossing over into dangerous areas. In this paper, the FPPS computation time is reduced by the multi-resolution scheme, and the flight path quality is improved by the path smoothing methods. Meanwhile, the FCS includes the fuzzy inference systems (FISs) based on the fuzzy logic. By using expert knowledge and experience to train the FIS, the controller can operate the unmanned helicopter without dynamic models. The integrated system of the FPPS and the FCS is aimed at providing navigation and guidance to the mission destination and it is implemented by coupling the flight simulation software, X-Plane, and the computing software, MATLAB. Simulations are performed and shown in real time three-dimensional animations. Finally, the integrated system is demonstrated to work successfully in controlling the unmanned helicopter to operate in various terrains of a digital elevation model (DEM).

  20. Integrated Flight Path Planning System and Flight Control System for Unmanned Helicopters

    Science.gov (United States)

    Jan, Shau Shiun; Lin, Yu Hsiang

    2011-01-01

    This paper focuses on the design of an integrated navigation and guidance system for unmanned helicopters. The integrated navigation system comprises two systems: the Flight Path Planning System (FPPS) and the Flight Control System (FCS). The FPPS finds the shortest flight path by the A-Star (A*) algorithm in an adaptive manner for different flight conditions, and the FPPS can add a forbidden zone to stop the unmanned helicopter from crossing over into dangerous areas. In this paper, the FPPS computation time is reduced by the multi-resolution scheme, and the flight path quality is improved by the path smoothing methods. Meanwhile, the FCS includes the fuzzy inference systems (FISs) based on the fuzzy logic. By using expert knowledge and experience to train the FIS, the controller can operate the unmanned helicopter without dynamic models. The integrated system of the FPPS and the FCS is aimed at providing navigation and guidance to the mission destination and it is implemented by coupling the flight simulation software, X-Plane, and the computing software, MATLAB. Simulations are performed and shown in real time three-dimensional animations. Finally, the integrated system is demonstrated to work successfully in controlling the unmanned helicopter to operate in various terrains of a digital elevation model (DEM). PMID:22164029

  1. Equity in financing and use of health care in Ghana, South Africa, and Tanzania: implications for paths to universal coverage.

    Science.gov (United States)

    Mills, Anne; Ataguba, John E; Akazili, James; Borghi, Jo; Garshong, Bertha; Makawia, Suzan; Mtei, Gemini; Harris, Bronwyn; Macha, Jane; Meheus, Filip; McIntyre, Di

    2012-07-14

    Universal coverage of health care is now receiving substantial worldwide and national attention, but debate continues on the best mix of financing mechanisms, especially to protect people outside the formal employment sector. Crucial issues are the equity implications of different financing mechanisms, and patterns of service use. We report a whole-system analysis--integrating both public and private sectors--of the equity of health-system financing and service use in Ghana, South Africa, and Tanzania. We used primary and secondary data to calculate the progressivity of each health-care financing mechanism, catastrophic spending on health care, and the distribution of health-care benefits. We collected qualitative data to inform interpretation. Overall health-care financing was progressive in all three countries, as were direct taxes. Indirect taxes were regressive in South Africa but progressive in Ghana and Tanzania. Out-of-pocket payments were regressive in all three countries. Health-insurance contributions by those outside the formal sector were regressive in both Ghana and Tanzania. The overall distribution of service benefits in all three countries favoured richer people, although the burden of illness was greater for lower-income groups. Access to needed, appropriate services was the biggest challenge to universal coverage in all three countries. Analyses of the equity of financing and service use provide guidance on which financing mechanisms to expand, and especially raise questions over the appropriate financing mechanism for the health care of people outside the formal sector. Physical and financial barriers to service access must be addressed if universal coverage is to become a reality. European Union and International Development Research Centre. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Robust path planning for flexible needle insertion using Markov decision processes.

    Science.gov (United States)

    Tan, Xiaoyu; Yu, Pengqian; Lim, Kah-Bin; Chui, Chee-Kong

    2018-05-11

    Flexible needle has the potential to accurately navigate to a treatment region in the least invasive manner. We propose a new planning method using Markov decision processes (MDPs) for flexible needle navigation that can perform robust path planning and steering under the circumstance of complex tissue-needle interactions. This method enhances the robustness of flexible needle steering from three different perspectives. First, the method considers the problem caused by soft tissue deformation. The method then resolves the common needle penetration failure caused by patterns of targets, while the last solution addresses the uncertainty issues in flexible needle motion due to complex and unpredictable tissue-needle interaction. Computer simulation and phantom experimental results show that the proposed method can perform robust planning and generate a secure control policy for flexible needle steering. Compared with a traditional method using MDPs, the proposed method achieves higher accuracy and probability of success in avoiding obstacles under complicated and uncertain tissue-needle interactions. Future work will involve experiment with biological tissue in vivo. The proposed robust path planning method can securely steer flexible needle within soft phantom tissues and achieve high adaptability in computer simulation.

  3. Autonomously Implemented Versatile Path Planning for Mobile Robots Based on Cellular Automata and Ant Colony

    Directory of Open Access Journals (Sweden)

    Adel Akbarimajd

    2012-02-01

    Full Text Available A path planning method for mobile robots based on two dimensional cellular automata is proposed. The method can be applied for environments with both concave and convex obstacles. It is also appropriate for multi-robot problems as well as dynamic environments. In order to develop the planning method, environment of the robot is decomposed to a rectangular grid and the automata is defined with four states including Robot cell, Free cell, Goal cell and Obstacle cell. Evolution rules of automata are proposed in order to direct the robot toward its goal. CA based path planner method is afterwards modified by a colony technique to be applicable for concave obstacles. Then a layered architecture is proposed to autonomously implement the planning algorithm. The architecture employs an abstraction approach which makes the complexity manageable. An important feature of the architecture is internal artifacts that have some beliefs about the world. Most actions of the robot are planned and performed with respect to these artifacts.

  4. A Novel Randomized Search Technique for Multiple Mobile Robot Paths Planning In Repetitive Dynamic Environment

    Directory of Open Access Journals (Sweden)

    Vahid Behravesh

    2012-08-01

    Full Text Available Presented article is studying the issue of path navigating for numerous robots. Our presented approach is based on both priority and the robust method for path finding in repetitive dynamic. Presented model can be generally implementable and useable: We do not assume any restriction regarding the quantity of levels of freedom for robots, and robots of diverse kinds can be applied at the same time. We proposed a random method and hill-climbing technique in the area based on precedence plans, which is used to determine a solution to a given trajectory planning problem and to make less the extent of total track. Our method plans trajectories for particular robots in the setting-time scope. Therefore, in order to specifying the interval of constant objects similar to other robots and the extent of the tracks which is traversed. For measuring the hazard for robots to conflict with each other it applied a method based on probability of the movements of robots. This algorithm applied to real robots with successful results. The proposed method performed and judged on both real robots and in simulation. We performed sequence of100tests with 8 robots for comparing with coordination method and current performances are effective. However, maximizing the performance is still possible. These performances estimations performed on Windows operating system and 3GHz Intel Pentium IV with and compiles with GCC 3.4. We used our PCGA robot for all experiments.  For a large environment of 19×15m2where we accomplished 40tests, our model is competent to plan high-quality paths in a severely short time (less than a second. Moreover, this article utilized lookup tables to keep expenses the formerly navigated robots made, increasing the number of robots don’t expand computation time.

  5. A new multiple robot path planning algorithm: dynamic distributed particle swarm optimization.

    Science.gov (United States)

    Ayari, Asma; Bouamama, Sadok

    2017-01-01

    Multiple robot systems have become a major study concern in the field of robotic research. Their control becomes unreliable and even infeasible if the number of robots increases. In this paper, a new dynamic distributed particle swarm optimization (D 2 PSO) algorithm is proposed for trajectory path planning of multiple robots in order to find collision-free optimal path for each robot in the environment. The proposed approach consists in calculating two local optima detectors, LOD pBest and LOD gBest . Particles which are unable to improve their personal best and global best for predefined number of successive iterations would be replaced with restructured ones. Stagnation and local optima problems would be avoided by adding diversity to the population, without losing the fast convergence characteristic of PSO. Experiments with multiple robots are provided and proved effectiveness of such approach compared with the distributed PSO.

  6. Time-optimal path planning in uncertain flow fields using ensemble method

    KAUST Repository

    Wang, Tong

    2016-01-06

    An ensemble-based approach is developed to conduct time-optimal path planning in unsteady ocean currents under uncertainty. We focus our attention on two-dimensional steady and unsteady uncertain flows, and adopt a sampling methodology that is well suited to operational forecasts, where a set deterministic predictions is used to model and quantify uncertainty in the predictions. In the operational setting, much about dynamics, topography and forcing of the ocean environment is uncertain, and as a result a single path produced by a model simulation has limited utility. To overcome this limitation, we rely on a finitesize ensemble of deterministic forecasts to quantify the impact of variability in the dynamics. The uncertainty of flow field is parametrized using a finite number of independent canonical random variables with known densities, and the ensemble is generated by sampling these variables. For each the resulting realizations of the uncertain current field, we predict the optimal path by solving a boundary value problem (BVP), based on the Pontryagin maximum principle. A family of backward-in-time trajectories starting at the end position is used to generate suitable initial values for the BVP solver. This allows us to examine and analyze the performance of sampling strategy, and develop insight into extensions dealing with regional or general circulation models. In particular, the ensemble method enables us to perform a statistical analysis of travel times, and consequently develop a path planning approach that accounts for these statistics. The proposed methodology is tested for a number of scenarios. We first validate our algorithms by reproducing simple canonical solutions, and then demonstrate our approach in more complex flow fields, including idealized, steady and unsteady double-gyre flows.

  7. Enroute flight-path planning - Cooperative performance of flight crews and knowledge-based systems

    Science.gov (United States)

    Smith, Philip J.; Mccoy, Elaine; Layton, Chuck; Galdes, Deb

    1989-01-01

    Interface design issues associated with the introduction of knowledge-based systems into the cockpit are discussed. Such issues include not only questions about display and control design, they also include deeper system design issues such as questions about the alternative roles and responsibilities of the flight crew and the computer system. In addition, the feasibility of using enroute flight path planning as a context for exploring such research questions is considered. In particular, the development of a prototyping shell that allows rapid design and study of alternative interfaces and system designs is discussed.

  8. Visibility-Based Goal Oriented Metrics and Application to Navigation and Path Planning Problems

    Science.gov (United States)

    2017-12-14

    Oriented Metrics and Application to Navigation and Path Planning Problems Report Term: 0-Other Email : ytsai@math.utexas.edu Distribution Statement: 1...error bounds that we have obtained. Report Date: 06-Dec-2017 INVESTIGATOR(S): Phone Number: 5122327757 Principal: Y Name: Yen-Hsi Tsai Email ...w1 w2 ◆ and ~z = ✓ z1 z2 ◆ . Then we can write D0 h (PN (xi,j)) = Rp (R+⌘)2+h2 + 1 2h (µ2w1 µ2z1) 0 µ2w2µ3z2 2h 0 ! . It follows that the non

  9. Constrained VPH+: a local path planning algorithm for a bio-inspired crawling robot with customized ultrasonic scanning sensor.

    Science.gov (United States)

    Rao, Akshay; Elara, Mohan Rajesh; Elangovan, Karthikeyan

    This paper aims to develop a local path planning algorithm for a bio-inspired, reconfigurable crawling robot. A detailed description of the robotic platform is first provided, and the suitability for deployment of each of the current state-of-the-art local path planners is analyzed after an extensive literature review. The Enhanced Vector Polar Histogram algorithm is described and reformulated to better fit the requirements of the platform. The algorithm is deployed on the robotic platform in crawling configuration and favorably compared with other state-of-the-art local path planning algorithms.

  10. A Method on Dynamic Path Planning for Robotic Manipulator Autonomous Obstacle Avoidance Based on an Improved RRT Algorithm.

    Science.gov (United States)

    Wei, Kun; Ren, Bingyin

    2018-02-13

    In a future intelligent factory, a robotic manipulator must work efficiently and safely in a Human-Robot collaborative and dynamic unstructured environment. Autonomous path planning is the most important issue which must be resolved first in the process of improving robotic manipulator intelligence. Among the path-planning methods, the Rapidly Exploring Random Tree (RRT) algorithm based on random sampling has been widely applied in dynamic path planning for a high-dimensional robotic manipulator, especially in a complex environment because of its probability completeness, perfect expansion, and fast exploring speed over other planning methods. However, the existing RRT algorithm has a limitation in path planning for a robotic manipulator in a dynamic unstructured environment. Therefore, an autonomous obstacle avoidance dynamic path-planning method for a robotic manipulator based on an improved RRT algorithm, called Smoothly RRT (S-RRT), is proposed. This method that targets a directional node extends and can increase the sampling speed and efficiency of RRT dramatically. A path optimization strategy based on the maximum curvature constraint is presented to generate a smooth and curved continuous executable path for a robotic manipulator. Finally, the correctness, effectiveness, and practicability of the proposed method are demonstrated and validated via a MATLAB static simulation and a Robot Operating System (ROS) dynamic simulation environment as well as a real autonomous obstacle avoidance experiment in a dynamic unstructured environment for a robotic manipulator. The proposed method not only provides great practical engineering significance for a robotic manipulator's obstacle avoidance in an intelligent factory, but also theoretical reference value for other type of robots' path planning.

  11. An Adaptive Multi-Objective Particle Swarm Optimization Algorithm for Multi-Robot Path Planning

    Directory of Open Access Journals (Sweden)

    Nizar Hadi Abbas

    2016-07-01

    Full Text Available This paper discusses an optimal path planning algorithm based on an Adaptive Multi-Objective Particle Swarm Optimization Algorithm (AMOPSO for two case studies. First case, single robot wants to reach a goal in the static environment that contain two obstacles and two danger source. The second one, is improving the ability for five robots to reach the shortest way. The proposed algorithm solves the optimization problems for the first case by finding the minimum distance from initial to goal position and also ensuring that the generated path has a maximum distance from the danger zones. And for the second case, finding the shortest path for every robot and without any collision between them with the shortest time. In order to evaluate the proposed algorithm in term of finding the best solution, six benchmark test functions are used to make a comparison between AMOPSO and the standard MOPSO. The results show that the AMOPSO has a better ability to get away from local optimums with a quickest convergence than the MOPSO. The simulation results using Matlab 2014a, indicate that this methodology is extremely valuable for every robot in multi-robot framework to discover its own particular proper pa‌th from the start to the destination position with minimum distance and time.

  12. Path Planning for Non-Circular, Non-Holonomic Robots in Highly Cluttered Environments.

    Science.gov (United States)

    Samaniego, Ricardo; Lopez, Joaquin; Vazquez, Fernando

    2017-08-15

    This paper presents an algorithm for finding a solution to the problem of planning a feasible path for a slender autonomous mobile robot in a large and cluttered environment. The presented approach is based on performing a graph search on a kinodynamic-feasible lattice state space of high resolution; however, the technique is applicable to many search algorithms. With the purpose of allowing the algorithm to consider paths that take the robot through narrow passes and close to obstacles, high resolutions are used for the lattice space and the control set. This introduces new challenges because one of the most computationally expensive parts of path search based planning algorithms is calculating the cost of each one of the actions or steps that could potentially be part of the trajectory. The reason for this is that the evaluation of each one of these actions involves convolving the robot's footprint with a portion of a local map to evaluate the possibility of a collision, an operation that grows exponentially as the resolution is increased. The novel approach presented here reduces the need for these convolutions by using a set of offline precomputed maps that are updated, by means of a partial convolution, as new information arrives from sensors or other sources. Not only does this improve run-time performance, but it also provides support for dynamic search in changing environments. A set of alternative fast convolution methods are also proposed, depending on whether the environment is cluttered with obstacles or not. Finally, we provide both theoretical and experimental results from different experiments and applications.

  13. Lagrangian coherent structure assisted path planning for transoceanic autonomous underwater vehicle missions.

    Science.gov (United States)

    Ramos, A G; García-Garrido, V J; Mancho, A M; Wiggins, S; Coca, J; Glenn, S; Schofield, O; Kohut, J; Aragon, D; Kerfoot, J; Haskins, T; Miles, T; Haldeman, C; Strandskov, N; Allsup, B; Jones, C; Shapiro, J

    2018-03-15

    Transoceanic Gliders are Autonomous Underwater Vehicles (AUVs) for which there is a developing and expanding range of applications in open-seas research, technology and underwater clean transport. Mature glider autonomy, operating depth (0-1000 meters) and low energy consumption without a CO 2 footprint enable evolutionary access across ocean basins. Pursuant to the first successful transatlantic glider crossing in December 2009, the Challenger Mission has opened the door to long-term, long-distance routine transoceanic AUV missions. These vehicles, which glide through the water column between 0 and 1000 meters depth, are highly sensitive to the ocean current field. Consequently, it is essential to exploit the complex space-time structure of the ocean current field in order to plan a path that optimizes scientific payoff and navigation efficiency. This letter demonstrates the capability of dynamical system theory for achieving this goal by realizing the real-time navigation strategy for the transoceanic AUV named Silbo, which is a Slocum deep-glider (0-1000 m), that crossed the North Atlantic from April 2016 to March 2017. Path planning in real time based on this approach has facilitated an impressive speed up of the AUV to unprecedented velocities resulting in major battery savings on the mission, offering the potential for routine transoceanic long duration missions.

  14. Optimal path planning for single and multiple aircraft using a reduced order formulation

    Science.gov (United States)

    Twigg, Shannon S.

    High-flying unmanned reconnaissance and surveillance systems are now being used extensively in the United States military. Current development programs are producing demonstrations of next-generation unmanned flight systems that are designed to perform combat missions. Their use in first-strike combat operations will dictate operations in densely cluttered environments that include unknown obstacles and threats, and will require the use of terrain for masking. The demand for autonomy of operations in such environments dictates the need for advanced trajectory optimization capabilities. In addition, the ability to coordinate the movements of more than one aircraft in the same area is an emerging challenge. This thesis examines using an analytical reduced order formulation for trajectory generation for minimum time and terrain masking cases. First, pseudo-3D constant velocity equations of motion are used for path planning for a single vehicle. In addition, the inclusion of winds, moving targets and moving threats is considered. Then, this formulation is increased to using 3D equations of motion, both with a constant velocity and with a simplified varying velocity model. Next, the constant velocity equations of motion are expanded to include the simultaneous path planning of an unspecified number of vehicles, for both aircraft avoidance situations and formation flight cases.

  15. Estimating family planning coverage from contraceptive prevalence using national household surveys.

    Science.gov (United States)

    Barros, Aluisio J D; Boerma, Ties; Hosseinpoor, Ahmad R; Restrepo-Méndez, María C; Wong, Kerry L M; Victora, Cesar G

    2015-01-01

    Contraception is one of the most important health interventions currently available and yet, many women and couples still do not have reliable access to modern contraceptives. The best indicator for monitoring family planning is the proportion of women using contraception among those who need it. This indicator is frequently called demand for family planning satisfied and we argue that it should be called family planning coverage (FPC). This indicator is complex to calculate and requires a considerable number of questions to be included in a household survey. We propose a model that can predict FPC from a much simpler indicator - contraceptive use prevalence - for situations where it cannot be derived directly. Using 197 Multiple Indicator Cluster Surveys and Demographic and Health Surveys from 82 countries, we explored least-squares regression models that could be used to predict FPC. Non-linearity was expected in this situation and we used a fractional polynomial approach to find the best fitting model. We also explored the effect of calendar time and of wealth on the models explored. Given the high correlation between the variables involved in FPC, we managed to derive a relatively simple model that depends only on contraceptive use prevalence but explains 95% of the variability of the outcome, with high precision for the estimated regression line. We also show that the relationship between the two variables has not changed with time. A concordance analysis showed agreement between observed and fitted results within a range of ±9 percentage points. We show that it is possible to obtain fairly good estimates of FPC using only contraceptive prevalence as a predictor, a strategy that is useful in situations where it is not possible to estimate FPC directly.

  16. Towards heterogeneous robot team path planning: acquisition of multiple routes with a modified spline-based algorithm

    Directory of Open Access Journals (Sweden)

    Lavrenov Roman

    2017-01-01

    Full Text Available Our research focuses on operation of a heterogeneous robotic group that carries out point-to point navigation in GPS-denied dynamic environment, applying a combined local and global planning approach. In this paper, we introduce a homotopy-based high-level planner, which uses a modified splinebased path-planning algorithm. The algorithm utilizes Voronoi graph for global planning and a set of optimization criteria for local improvements of selected paths. The simulation was implemented in Matlab environment.

  17. Probabilistic Path Planning of Montgolfier Balloons in Strong, Uncertain Wind Fields

    Science.gov (United States)

    Wolf, Michael; Blackmore, James C.; Kuwata, Yoshiaki

    2011-01-01

    Lighter-than-air vehicles such as hot-air balloons have been proposed for exploring Saturn s moon Titan, as well as other bodies with significant atmospheres. For these vehicles to navigate effectively, it is critical to incorporate the effects of surrounding wind fields, especially as these winds will likely be strong relative to the control authority of the vehicle. Predictive models of these wind fields are available, and previous research has considered problems of planning paths subject to these predicted forces. However, such previous work has considered the wind fields as known a priori, whereas in practical applications, the actual wind vector field is not known exactly and may deviate significantly from the wind velocities estimated by the model. A probabilistic 3D path-planning algorithm was developed for balloons to use uncertain wind models to generate time-efficient paths. The nominal goal of the algorithm is to determine what altitude and what horizontal actuation, if any is available on the vehicle, to use to reach a particular goal location in the least expected time, utilizing advantageous winds. The solution also enables one to quickly evaluate the expected time-to-goal from any other location and to avoid regions of large uncertainty. This method is designed for balloons in wind fields but may be generalized for any buoyant vehicle operating in a vector field. To prepare the planning problem, the uncertainty in the wind field is modeled. Then, the problem of reaching a particular goal location is formulated as a Markov decision process (MDP) using a discretized space approach. Solving the MDP provides a policy of what actuation option (how much buoyancy change and, if applicable, horizontal actuation) should be selected at any given location to minimize the expected time-to-goal. The results provide expected time-to-goal values from any given location on the globe in addition to the action policy. This stochastic approach can also provide

  18. Global and Local Path Planning Study in a ROS-Based Research Platform for Autonomous Vehicles

    Directory of Open Access Journals (Sweden)

    Pablo Marin-Plaza

    2018-01-01

    Full Text Available The aim of this work is to integrate and analyze the performance of a path planning method based on Time Elastic Bands (TEB in real research platform based on Ackermann model. Moreover, it will be proved that all modules related to the navigation can coexist and work together to achieve the goal point without any collision. The study is done by analyzing the trajectory generated from global and local planners. The software prototyping tool is Robot Operating System (ROS from Open Source Robotics Foundation and the research platform is the iCab (Intelligent Campus Automobile from University Carlos III. This work has been validated from a test inside the campus where the iCab has performed the navigation between the starting point and the goal point without any collision. During the experiment, we proved the low sensitivity of the TEB method to variations of the vehicle model configuration and constraints.

  19. Optimal path planning for video-guided smart munitions via multitarget tracking

    Science.gov (United States)

    Borkowski, Jeffrey M.; Vasquez, Juan R.

    2006-05-01

    An advent in the development of smart munitions entails autonomously modifying target selection during flight in order to maximize the value of the target being destroyed. A unique guidance law can be constructed that exploits both attribute and kinematic data obtained from an onboard video sensor. An optimal path planning algorithm has been developed with the goals of obstacle avoidance and maximizing the value of the target impacted by the munition. Target identification and classification provides a basis for target value which is used in conjunction with multi-target tracks to determine an optimal waypoint for the munition. A dynamically feasible trajectory is computed to provide constraints on the waypoint selection. Results demonstrate the ability of the autonomous system to avoid moving obstacles and revise target selection in flight.

  20. MR-based real time path planning for cardiac operations with transapical access.

    Science.gov (United States)

    Yeniaras, Erol; Navkar, Nikhil V; Sonmez, Ahmet E; Shah, Dipan J; Deng, Zhigang; Tsekos, Nikolaos V

    2011-01-01

    Minimally invasive surgeries (MIS) have been perpetually evolving due to their potential high impact on improving patient management and overall cost effectiveness. Currently, MIS are further strengthened by the incorporation of magnetic resonance imaging (MRI) for amended visualization and high precision. Motivated by the fact that real-time MRI is emerging as a feasible modality especially for guiding interventions and surgeries in the beating heart; in this paper we introduce a real-time path planning algorithm for intracardiac procedures. Our approach creates a volumetric safety zone inside a beating heart and updates it on-the-fly using real-time MRI during the deployment of a robotic device. In order to prove the concept and assess the feasibility of the introduced method, a realistic operational scenario of transapical aortic valve replacement in a beating heart is chosen as the virtual case study.

  1. New Design of Mobile Robot Path Planning with Randomly Moving Obstacles

    Directory of Open Access Journals (Sweden)

    T. A. Salih

    2013-05-01

    Full Text Available The navigation of a mobile robot in an unknown environment has always been a very challenging task. In order to achieve safe and autonomous navigation, the mobile robot needs to sense the surrounding environment and plans a collision-free path. This paper focuses on designing and implementing a mobile robot which has the ability of navigating smoothly in an unknown environment, avoiding collisions, without having to stop in front of obstacles, detecting leakage of combustible gases and transmitting a message of detection results to the civil defense unit automatically through the Internet to the E-mail. This design uses the implementation of artificial neural network (ANN on a new technology represented by Field Programmable Analog Array (FPAA for controlling the motion of the robot. The robot with the proposed controller is tested and has completed the required objective successfully.

  2. Estimated effects of adding universal public coverage of an essential medicines list to existing public drug plans in Canada.

    Science.gov (United States)

    Morgan, Steven G; Li, Winny; Yau, Brandon; Persaud, Nav

    2017-02-27

    Canada's universal health care system does not include universal coverage of prescription drugs. We sought to estimate the effects of adding universal public coverage of an essential medicines list to existing public drug plans in Canada. We used administrative and market research data to estimate the 2015 shares of the volume and cost of prescriptions filled in the community setting that were for 117 drugs on a model list of essential medicines for Canada. We compared prices of these essential medicines in Canada with prices in the United States, Sweden and New Zealand. We estimated the cost of adding universal public drug coverage of these essential medicines based on anticipated effects on medication use and pricing. The 117 essential medicines on the model list accounted for 44% of all prescriptions and 30% of total prescription drug expenditures in 2015. Average prices of generic essential medicines were 47% lower in the US, 60% lower in Sweden and 84% lower in New Zealand; brand-name drugs were priced 43% lower in the US. Estimated savings from universal public coverage of these essential medicines was $4.27 billion per year (range $2.72 billion to $5.83 billion; 28% reduction) for patients and private drug plan sponsors, at an incremental government cost of $1.23 billion per year (range $373 million to $1.98 billion; 11% reduction). Our analysis showed that adding universal public coverage of essential medicines to the existing public drug plans in Canada could address most of Canadians' pharmaceutical needs and save billions of dollars annually. Doing so may be a pragmatic step forward while more comprehensive pharmacare reforms are planned. © 2017 Canadian Medical Association or its licensors.

  3. Employing Multiple Unmanned Aerial Vehicles for Co-Operative Path Planning

    Directory of Open Access Journals (Sweden)

    Durdana Habib

    2013-05-01

    Full Text Available Abstract In this paper, we work to develop a path planning solution for a group of Unmanned Aerial Vehicles (UAVs using a Mixed Integer Linear Programming (MILP approach. Co-operation among team members not only helps reduce mission time, it makes the execution more robust in dynamic environments. However, the problem becomes more challenging as it requires optimal resource allocation and is NP-hard. Since UAVs may be lost or may suffer significant damage during the course of the mission, plans may need to be modified in real-time as the mission proceeds. Therefore, multiple UAVs have a better chance of completing a mission in the face of failures. Such military operations can be treated as a variant of the Multiple Depot Vehicle Routing Problem (MDVRP. The proposed solution must be such that m UAVs start from multiple source locations to visit n targets and return to a set of destination locations such that (1 each target is visited exactly by one of the chosen UAVs (2 the total distance travelled by the group is minimized and (3 the number of targets that each UAV visits may not be less than K or greater than L.

  4. Path planning in GPS-denied environments via collective intelligence of distributed sensor networks

    Science.gov (United States)

    Jha, Devesh K.; Chattopadhyay, Pritthi; Sarkar, Soumik; Ray, Asok

    2016-05-01

    This paper proposes a framework for reactive goal-directed navigation without global positioning facilities in unknown dynamic environments. A mobile sensor network is used for localising regions of interest for path planning of an autonomous mobile robot. The underlying theory is an extension of a generalised gossip algorithm that has been recently developed in a language-measure-theoretic setting. The algorithm has been used to propagate local decisions of target detection over a mobile sensor network and thus, it generates a belief map for the detected target over the network. In this setting, an autonomous mobile robot may communicate only with a few mobile sensing nodes in its own neighbourhood and localise itself relative to the communicating nodes with bounded uncertainties. The robot makes use of the knowledge based on the belief of the mobile sensors to generate a sequence of way-points, leading to a possible goal. The estimated way-points are used by a sampling-based motion planning algorithm to generate feasible trajectories for the robot. The proposed concept has been validated by numerical simulation on a mobile sensor network test-bed and a Dubin's car-like robot.

  5. Panning for Gold: The personal journey of mental health wellness and its relationships with Planning Alternatives Tomorrows with Hope (PATH

    Directory of Open Access Journals (Sweden)

    Matthew Lyndon Armstrong

    2015-12-01

    Full Text Available This study explored how the Planning Alternatives Tomorrows with Hope (PATH process could enhance and strengthen an individual’s personal journey of recovery. This article utilised the knowledge base of members of a Community of Practice, located in Brisbane Australia. Members had a deep concern and passion to promote and strengthen wellbeing for people who live with the experience of mental ill health. They were invited to form a focus group to explore the use of PATH and its relationship with mental health wellness. After contemplating and reflecting on an example of the PATH process, the focus group explored opportunities for PATH to become one of many wellness resources for people experiencing and overcoming mental ill health. Through the exploration of personal meaning, storytelling and community connection (anchored in the visuals and graphics of the PATH example, the study found that PATH can make a valuable contribution by restoring some of the power inbalances in traditonal service frameworks and enhancing personal self direction. Keywords: mental health distress, practitioners, recovery, facilitation, creativity, planning

  6. A Distributed Framework for Real Time Path Planning in Practical Multi-agent Systems

    KAUST Repository

    Abdelkader, Mohamed

    2017-10-19

    We present a framework for distributed, energy efficient, and real time implementable algorithms for path planning in multi-agent systems. The proposed framework is presented in the context of a motivating example of capture the flag which is an adversarial game played between two teams of autonomous agents called defenders and attackers. We start with the centralized formulation of the problem as a linear program because of its computational efficiency. Then we present an approximation framework in which each agent solves a local version of the centralized linear program by communicating with its neighbors only. The premise in this work is that for practical multi-agent systems, real time implementability of distributed algorithms is more crucial then global optimality. Thus, instead of verifying the proposed framework by performing offline simulations in MATLAB, we run extensive simulations in a robotic simulator V-REP, which includes a detailed dynamic model of quadrotors. Moreover, to create a realistic scenario, we allow a human operator to control the attacker quadrotor through a joystick in a single attacker setup. These simulations authenticate that the proposed framework is real time implementable and results in a performance that is comparable with the global optimal solution under the considered scenarios.

  7. Dynamic Modeling and Soil Mechanics for Path Planning of the Mars Exploration Rovers

    Science.gov (United States)

    Trease, Brian; Arvidson, Raymond; Lindemann, Randel; Bennett, Keith; Zhou, Feng; Iagnemma, Karl; Senatore, Carmine; Van Dyke, Lauren

    2011-01-01

    To help minimize risk of high sinkage and slippage during drives and to better understand soil properties and rover terramechanics from drive data, a multidisciplinary team was formed under the Mars Exploration Rover (MER) project to develop and utilize dynamic computer-based models for rover drives over realistic terrains. The resulting tool, named ARTEMIS (Adams-based Rover Terramechanics and Mobility Interaction Simulator), consists of the dynamic model, a library of terramechanics subroutines, and the high-resolution digital elevation maps of the Mars surface. A 200-element model of the rovers was developed and validated for drop tests before launch, using MSC-Adams dynamic modeling software. Newly modeled terrain-rover interactions include the rut-formation effect of deformable soils, using the classical Bekker-Wong implementation of compaction resistances and bull-dozing effects. The paper presents the details and implementation of the model with two case studies based on actual MER telemetry data. In its final form, ARTEMIS will be used in a predictive manner to assess terrain navigability and will become part of the overall effort in path planning and navigation for both Martian and lunar rovers.

  8. Hierarchical heuristic search using a Gaussian mixture model for UAV coverage planning.

    Science.gov (United States)

    Lin, Lanny; Goodrich, Michael A

    2014-12-01

    During unmanned aerial vehicle (UAV) search missions, efficient use of UAV flight time requires flight paths that maximize the probability of finding the desired subject. The probability of detecting the desired subject based on UAV sensor information can vary in different search areas due to environment elements like varying vegetation density or lighting conditions, making it likely that the UAV can only partially detect the subject. This adds another dimension of complexity to the already difficult (NP-Hard) problem of finding an optimal search path. We present a new class of algorithms that account for partial detection in the form of a task difficulty map and produce paths that approximate the payoff of optimal solutions. The algorithms use the mode goodness ratio heuristic that uses a Gaussian mixture model to prioritize search subregions. The algorithms search for effective paths through the parameter space at different levels of resolution. We compare the performance of the new algorithms against two published algorithms (Bourgault's algorithm and LHC-GW-CONV algorithm) in simulated searches with three real search and rescue scenarios, and show that the new algorithms outperform existing algorithms significantly and can yield efficient paths that yield payoffs near the optimal.

  9. Path planning for first responders in the presence of moving obstacles

    Directory of Open Access Journals (Sweden)

    Zhiyong Wang

    2015-06-01

    Full Text Available Navigation services have gained much importance for all kinds of human activities ranging from tourist navigation to support of rescue teams in disaster management. However, despite the considerable amount of route guidance research that has been performed, many issues that are related to navigation for first responders still need to be addressed. During disasters, emergencies can result in different types of moving obstacles (e.g., fires, plumes, floods, which make some parts of the road network temporarily unavailable. After such incidents occur, responders have to go to different destinations to perform their tasks in the environment affected by the disaster. Therefore they need a path planner that is capable of dealing with such moving obstacles, as well as generating and coordinating their routes quickly and efficiently. During the past decades, more and more hazard simulations, which can modify the models with incorporation of dynamic data from the field, have been developed. These hazard simulations use methods such as data assimilation, stochastic estimation, and adaptive measurement techniques, and are able to generate more reliable results of hazards. This would allow the hazard simulation models to provide valuable information regarding the state of road networks affected by hazards, which supports path planning for first responders among the moving obstacles. The objective of this research is to develop an integrated navigation system for first responders in the presence of moving obstacles. Such system should be able to navigate one or more responders to one or multiple destinations avoiding the moving obstacles, using the predicted information of the moving obstacles generated from by hazard simulations. In this dissertation, the objective we have is expressed as the following research question: How do we safely and efficiently navigate one or more first responders to one or more destinations avoiding moving obstacles? To address

  10. Presentation of a Modified Boustrophedon Decomposition Algorithm for Optimal Configuration of Flat Fields to use in Path Planning Systems of Agricultural Vehicles

    Directory of Open Access Journals (Sweden)

    R Goudarzi

    2018-03-01

    Full Text Available Introduction The demand of pre-determined optimal coverage paths in agricultural environments have been increased due to the growing application of field robots and autonomous field machines. Also coverage path planning problem (CPP has been extensively studied in robotics and many algorithms have been provided in many topics, but differences and limitations in agriculture lead to several different heuristic and modified adaptive methods from robotics. In this paper, a modified and enhanced version of currently used decomposition algorithm in robotics (boustrophedon cellular decomposition has been presented as a main part of path planning systems of agricultural vehicles. Developed algorithm is based on the parallelization of the edges of the polygon representing the environment to satisfy the requirements of the problem as far as possible. This idea is based on "minimum facing to the cost making condition" in turn, it is derived from encounter concept as a basis of cost making factors. Materials and Methods Generally, a line termed as a slice in boustrophedon cellular decomposition (BCD, sweeps an area in a pre-determined direction and decomposes the area only at critical points (where two segments can be extended to top and bottom of the point. Furthermore, sweep line direction does not change until the decomposition finish. To implement the BCD for parallelization method, two modifications were applied in order to provide a modified version of the boustrophedon cellular decomposition (M-BCD. In the first modification, the longest edge (base edge is targeted, and sweep line direction is set in line with the base edge direction (sweep direction is set perpendicular to the sweep line direction. Then Sweep line moves through the environment and stops at the first (nearest critical point. Next sweep direction will be the same as previous, If the length of those polygon's newly added edges, during the decomposition, are less than or equal to the

  11. Path-Constrained Motion Planning for Robotics Based on Kinematic Constraints

    NARCIS (Netherlands)

    Dijk, van N.J.M.; Wouw, van de N.; Pancras, W.C.M.; Nijmeijer, H.

    2007-01-01

    Common robotic tracking tasks consist of motions along predefined paths. The design of time-optimal path-constrained trajectories for robotic applications is discussed in this paper. To increase industrial applicability, the proposed method accounts for robot kinematics together with actuator

  12. Immunization Coverage

    Science.gov (United States)

    ... room/fact-sheets/detail/immunization-coverage","@context":"http://schema.org","@type":"Article"}; العربية 中文 français русский español ... Plan Global Health Observatory (GHO) data - Immunization More information on vaccines and immunization News 1 in 10 ...

  13. Toward Shared Working Space of Human and Robotic Agents Through Dipole Flow Field for Dependable Path Planning.

    Science.gov (United States)

    Trinh, Lan Anh; Ekström, Mikael; Cürüklü, Baran

    2018-01-01

    Recent industrial developments in autonomous systems, or agents, which assume that humans and the agents share the same space or even work in close proximity, open for new challenges in robotics, especially in motion planning and control. In these settings, the control system should be able to provide these agents a reliable path following control when they are working in a group or in collaboration with one or several humans in complex and dynamic environments. In such scenarios, these agents are not only moving to reach their goals, i.e., locations, they are also aware of the movements of other entities to find a collision-free path. Thus, this paper proposes a dependable, i.e., safe, reliable and effective, path planning algorithm for a group of agents that share their working space with humans. Firstly, the method employs the Theta * algorithm to initialize the paths from a starting point to a goal for a set of agents. As Theta * algorithm is computationally heavy, it only reruns when there is a significant change of the environment. To deal with the movements of the agents, a static flow field along the configured path is defined. This field is used by the agents to navigate and reach their goals even if the planned trajectories are changed. Secondly, a dipole field is calculated to avoid the collision of agents with other agents and human subjects. In this approach, each agent is assumed to be a source of a magnetic dipole field in which the magnetic moment is aligned with the moving direction of the agent. The magnetic dipole-dipole interactions between these agents generate repulsive forces to help them to avoid collision. The effectiveness of the proposed approach has been evaluated with extensive simulations. The results show that the static flow field is able to drive agents to the goals with a small number of requirements to update the path of agents. Meanwhile, the dipole flow field plays an important role to prevent collisions. The combination of

  14. Toward Shared Working Space of Human and Robotic Agents Through Dipole Flow Field for Dependable Path Planning

    Directory of Open Access Journals (Sweden)

    Lan Anh Trinh

    2018-06-01

    Full Text Available Recent industrial developments in autonomous systems, or agents, which assume that humans and the agents share the same space or even work in close proximity, open for new challenges in robotics, especially in motion planning and control. In these settings, the control system should be able to provide these agents a reliable path following control when they are working in a group or in collaboration with one or several humans in complex and dynamic environments. In such scenarios, these agents are not only moving to reach their goals, i.e., locations, they are also aware of the movements of other entities to find a collision-free path. Thus, this paper proposes a dependable, i.e., safe, reliable and effective, path planning algorithm for a group of agents that share their working space with humans. Firstly, the method employs the Theta* algorithm to initialize the paths from a starting point to a goal for a set of agents. As Theta* algorithm is computationally heavy, it only reruns when there is a significant change of the environment. To deal with the movements of the agents, a static flow field along the configured path is defined. This field is used by the agents to navigate and reach their goals even if the planned trajectories are changed. Secondly, a dipole field is calculated to avoid the collision of agents with other agents and human subjects. In this approach, each agent is assumed to be a source of a magnetic dipole field in which the magnetic moment is aligned with the moving direction of the agent. The magnetic dipole-dipole interactions between these agents generate repulsive forces to help them to avoid collision. The effectiveness of the proposed approach has been evaluated with extensive simulations. The results show that the static flow field is able to drive agents to the goals with a small number of requirements to update the path of agents. Meanwhile, the dipole flow field plays an important role to prevent collisions. The

  15. Path Planning and Replanning for Mobile Robot Navigation on 3D Terrain: An Approach Based on Geodesic

    Directory of Open Access Journals (Sweden)

    Kun-Lin Wu

    2016-01-01

    Full Text Available In this paper, mobile robot navigation on a 3D terrain with a single obstacle is addressed. The terrain is modelled as a smooth, complete manifold with well-defined tangent planes and the hazardous region is modelled as an enclosing circle with a hazard grade tuned radius representing the obstacle projected onto the terrain to allow efficient path-obstacle intersection checking. To resolve the intersections along the initial geodesic, by resorting to the geodesic ideas from differential geometry on surfaces and manifolds, we present a geodesic-based planning and replanning algorithm as a new method for obstacle avoidance on a 3D terrain without using boundary following on the obstacle surface. The replanning algorithm generates two new paths, each a composition of two geodesics, connected via critical points whose locations are found to be heavily relying on the exploration of the terrain via directional scanning on the tangent plane at the first intersection point of the initial geodesic with the circle. An advantage of this geodesic path replanning procedure is that traversability of terrain on which the detour path traverses could be explored based on the local Gauss-Bonnet Theorem of the geodesic triangle at the planning stage. A simulation demonstrates the practicality of the analytical geodesic replanning procedure for navigating a constant speed point robot on a 3D hill-like terrain.

  16. An improved artificial bee colony algorithm based on balance-evolution strategy for unmanned combat aerial vehicle path planning.

    Science.gov (United States)

    Li, Bai; Gong, Li-gang; Yang, Wen-lun

    2014-01-01

    Unmanned combat aerial vehicles (UCAVs) have been of great interest to military organizations throughout the world due to their outstanding capabilities to operate in dangerous or hazardous environments. UCAV path planning aims to obtain an optimal flight route with the threats and constraints in the combat field well considered. In this work, a novel artificial bee colony (ABC) algorithm improved by a balance-evolution strategy (BES) is applied in this optimization scheme. In this new algorithm, convergence information during the iteration is fully utilized to manipulate the exploration/exploitation accuracy and to pursue a balance between local exploitation and global exploration capabilities. Simulation results confirm that BE-ABC algorithm is more competent for the UCAV path planning scheme than the conventional ABC algorithm and two other state-of-the-art modified ABC algorithms.

  17. An Improved Artificial Bee Colony Algorithm Based on Balance-Evolution Strategy for Unmanned Combat Aerial Vehicle Path Planning

    Directory of Open Access Journals (Sweden)

    Bai Li

    2014-01-01

    Full Text Available Unmanned combat aerial vehicles (UCAVs have been of great interest to military organizations throughout the world due to their outstanding capabilities to operate in dangerous or hazardous environments. UCAV path planning aims to obtain an optimal flight route with the threats and constraints in the combat field well considered. In this work, a novel artificial bee colony (ABC algorithm improved by a balance-evolution strategy (BES is applied in this optimization scheme. In this new algorithm, convergence information during the iteration is fully utilized to manipulate the exploration/exploitation accuracy and to pursue a balance between local exploitation and global exploration capabilities. Simulation results confirm that BE-ABC algorithm is more competent for the UCAV path planning scheme than the conventional ABC algorithm and two other state-of-the-art modified ABC algorithms.

  18. STRATEGIC INFORMATION SYSTEMS PLANNING IN THE BANKING SECTOR—A PATH ANALYTIC MODEL STUDY IN THE INDIAN CONTEXT

    Directory of Open Access Journals (Sweden)

    A. M. Rawani

    2002-01-01

    Full Text Available This paper presents a path analytic model showing the cause and effect relationships among various Information Systems (IS planning variables for the banking sector in India. In recent years, there has been an increased awareness among banks of the potential of Information Technology (IT and the use of information systems. Strategic information system planning (SISP becomes an important issue in the use of IS strategically. In India, banks have now started realizing the importance of SISP. In this study, 11 IS planning variables for the banking sector in India are examined and the influence of one over the other is investigated using path analysis. Data for the study are collected from 52 banks operating in India. The results of the study indicate that top management involvement in IS planning greatly influences the whole planning exercise. Moreover, top management involvement is higher when they foresee greater future impact of IS. The study also highlights the need and importance of user training in the banking sector. Change in the focus and orientation of user-training will make the users competent to conceive with innovative IS applications.

  19. Poster - 36: Effect of Planning Target Volume Coverage on the Dose Delivered in Lung Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Dekker, Chris; Wierzbicki, Marcin [McMaster University, Juravinski Cancer Centre (Canada)

    2016-08-15

    Purpose: In lung radiotherapy, breathing motion may be encompassed by contouring the internal target volume (ITV). Remaining uncertainties are included in a geometrical expansion to the planning target volume (PTV). In IMRT, the treatment is then optimized until a desired PTV fraction is covered by the appropriate dose. The resulting beams often carry high fluence in the PTV margin to overcome low lung density and to generate steep dose gradients. During treatment, the high density tumour can enter the PTV margin, potentially increasing target dose. Thus, planning lung IMRT with a reduced PTV dose may still achieve the desired ITV dose during treatment. Methods: A retrospective analysis was carried out with 25 IMRT plans prescribed to 63 Gy in 30 fractions. The plans were re-normalized to cover various fractions of the PTV by different isodose lines. For each case, the isocentre was moved using 125 shifts derived from all 3D combinations of 0 mm, (PTV margin - 1 mm), and PTV margin. After each shift, the dose was recomputed to approximate the delivered dose. Results and Conclusion: Our plans typically cover 95% of the PTV by 95% of the dose. Reducing the PTV covered to 94% did not significantly reduce the delivered ITV doses for (PTV margin - 1 mm) shifts. Target doses were reduced significantly for all other shifts and planning goals studied. Thus, a reduced planning goal will likely deliver the desired target dose as long as the ITV rarely enters the last mm of the PTV margin.

  20. Introduction of a computer-based method for automated planning of reduction paths under consideration of simulated muscular forces.

    Science.gov (United States)

    Buschbaum, Jan; Fremd, Rainer; Pohlemann, Tim; Kristen, Alexander

    2017-08-01

    Reduction is a crucial step in the surgical treatment of bone fractures. Finding an optimal path for restoring anatomical alignment is considered technically demanding because collisions as well as high forces caused by surrounding soft tissues can avoid desired reduction movements. The repetition of reduction movements leads to a trial-and-error process which causes a prolonged duration of surgery. By planning an appropriate reduction path-an optimal sequence of target-directed movements-these problems should be overcome. For this purpose, a computer-based method has been developed. Using the example of simple femoral shaft fractures, 3D models are generated out of CT images. A reposition algorithm aligns both fragments by reconstructing their broken edges. According to the criteria of a deduced planning strategy, a modified A*-algorithm searches collision-free route of minimal force from the dislocated into the computed target position. Muscular forces are considered using a musculoskeletal reduction model (OpenSim model), and bone collisions are detected by an appropriate method. Five femoral SYNBONE models were broken into different fracture classification types and were automatically reduced from ten randomly selected displaced positions. Highest mean translational and rotational error for achieving target alignment is [Formula: see text] and [Formula: see text]. Mean value and standard deviation of occurring forces are [Formula: see text] for M. tensor fasciae latae and [Formula: see text] for M. semitendinosus over all trials. These pathways are precise, collision-free, required forces are minimized, and thus regarded as optimal paths. A novel method for planning reduction paths under consideration of collisions and muscular forces is introduced. The results deliver additional knowledge for an appropriate tactical reduction procedure and can provide a basis for further navigated or robotic-assisted developments.

  1. Calibration of neural networks using genetic algorithms, with application to optimal path planning

    Science.gov (United States)

    Smith, Terence R.; Pitney, Gilbert A.; Greenwood, Daniel

    1987-01-01

    Genetic algorithms (GA) are used to search the synaptic weight space of artificial neural systems (ANS) for weight vectors that optimize some network performance function. GAs do not suffer from some of the architectural constraints involved with other techniques and it is straightforward to incorporate terms into the performance function concerning the metastructure of the ANS. Hence GAs offer a remarkably general approach to calibrating ANS. GAs are applied to the problem of calibrating an ANS that finds optimal paths over a given surface. This problem involves training an ANS on a relatively small set of paths and then examining whether the calibrated ANS is able to find good paths between arbitrary start and end points on the surface.

  2. Energy Optimal Path Planning: Integrating Coastal Ocean Modelling with Optimal Control

    Science.gov (United States)

    Subramani, D. N.; Haley, P. J., Jr.; Lermusiaux, P. F. J.

    2016-02-01

    A stochastic optimization methodology is formulated for computing energy-optimal paths from among time-optimal paths of autonomous vehicles navigating in a dynamic flow field. To set up the energy optimization, the relative vehicle speed and headings are considered to be stochastic, and new stochastic Dynamically Orthogonal (DO) level-set equations that govern their stochastic time-optimal reachability fronts are derived. Their solution provides the distribution of time-optimal reachability fronts and corresponding distribution of time-optimal paths. An optimization is then performed on the vehicle's energy-time joint distribution to select the energy-optimal paths for each arrival time, among all stochastic time-optimal paths for that arrival time. The accuracy and efficiency of the DO level-set equations for solving the governing stochastic level-set reachability fronts are quantitatively assessed, including comparisons with independent semi-analytical solutions. Energy-optimal missions are studied in wind-driven barotropic quasi-geostrophic double-gyre circulations, and in realistic data-assimilative re-analyses of multiscale coastal ocean flows. The latter re-analyses are obtained from multi-resolution 2-way nested primitive-equation simulations of tidal-to-mesoscale dynamics in the Middle Atlantic Bight and Shelbreak Front region. The effects of tidal currents, strong wind events, coastal jets, and shelfbreak fronts on the energy-optimal paths are illustrated and quantified. Results showcase the opportunities for longer-duration missions that intelligently utilize the ocean environment to save energy, rigorously integrating ocean forecasting with optimal control of autonomous vehicles.

  3. Solving a Class of Spatial Reasoning Problems: Minimal-Cost Path Planning in the Cartesian Plane.

    Science.gov (United States)

    1987-06-01

    as in Figure 72. By the Theorem of Pythagoras : Z1 <a z 2 < C Yl(bl+b 2)uI, the cost of going along (a,b,c) is greater that the...preceding lemmas to an indefinite number of boundary-crossing episodes is accomplished by the following theorems . Theorem 1 extends the result of Lemma 1... Theorem 1: Any two Snell’s-law paths within a K-explored wedge defined by Snell’s-law paths RL and R. do not intersect within the K-explored portion of

  4. Policy Choices for Progressive Realization of Universal Health Coverage; Comment on “Ethical Perspective: Five Unacceptable Trade-offs on the Path to Universal Health Coverage”

    Directory of Open Access Journals (Sweden)

    Viroj Tangcharoensathien

    2017-03-01

    Full Text Available In responses to Norheim’s editorial, this commentary offers reflections from Thailand, how the five unacceptable trade-offs were applied to the universal health coverage (UHC reforms between 1975 and 2002 when the whole 64 million people were covered by one of the three public health insurance systems. This commentary aims to generate global discussions on how best UHC can be gradually achieved. Not only the proposed five discrete tradeoffs within each dimension, there are also trade-offs between the three dimensions of UHC such as population coverage, service coverage and cost coverage. Findings from Thai UHC show that equity is applied for the population coverage extension, when the low income households and the informal sector were the priority population groups for coverage extension by different prepayment schemes in 1975 and 1984, respectively. With an exception of public sector employees who were historically covered as part of fringe benefits were covered well before the poor. The private sector employees were covered last in 1990. Historically, Thailand applied a comprehensive benefit package where a few items are excluded using the negative list; until there was improved capacities on technology assessment that cost-effectiveness are used for the inclusion of new interventions into the benefit package. Not only costeffectiveness, but long term budget impact, equity and ethical considerations are taken into account. Cost coverage is mostly determined by the fiscal capacities. Close ended budget with mix of provider payment methods are used as a tool for trade-off service coverage and financial risk protection. Introducing copayment in the context of feefor-service can be harmful to beneficiaries due to supplier induced demands, inefficiency and unpredictable out of pocket payment by households. UHC achieves favorable outcomes as it was implemented when there was a full geographical coverage of primary healthcare coverage in all

  5. Smooth Jerk-Bounded Optimal Path Planning of Tricycle Wheeled Mobile Manipulators in the Presence of Environmental Obstacles

    Directory of Open Access Journals (Sweden)

    Moharam Habibnejad Korayem

    2012-10-01

    Full Text Available In this work, a computational algorithm is developed for the smooth-jerk optimal path planning of tricycle wheeled mobile manipulators in an obstructed environment. Due to a centred orientable wheel, the tricycle mobile manipulator exhibits more steerability and manoeuvrability over traditional mobile manipulators, especially in the presence of environmental obstacles. This paper presents a general formulation based on the combination of the potential field method and optimal control theory in order to plan the smooth point-to-point path of the tricycle mobile manipulators. The nonholonomic constraints of the tricycle mobile base are taken into account in the dynamic formulation of the system and then the optimality conditions are derived considering jerk restrictions and obstacle avoidance. Furthermore, by means of the potential field method, a new formulation of a repulsive potential function is proposed for collision avoidance between any obstacle and each part of the mobile manipulator. In addition, to ensure the accurate placement of the end effector on the target point an attractive potential function is applied to the optimal control formulation. Next, a mixed analytical-numerical algorithm is proposed to generate the point-to-point optimal path. Finally, the proposed method is verified by a number of simulations on a two-link tricycle manipulator.

  6. RSMDP-based Robust Q-learning for Optimal Path Planning in a Dynamic Environment

    Directory of Open Access Journals (Sweden)

    Yunfei Zhang

    2014-07-01

    Full Text Available This paper presents arobust Q-learning method for path planningin a dynamic environment. The method consists of three steps: first, a regime-switching Markov decision process (RSMDP is formed to present the dynamic environment; second a probabilistic roadmap (PRM is constructed, integrated with the RSMDP and stored as a graph whose nodes correspond to a collision-free world state for the robot; and third, an onlineQ-learning method with dynamic stepsize, which facilitates robust convergence of the Q-value iteration, is integrated with the PRM to determine an optimal path for reaching the goal. In this manner, the robot is able to use past experience for improving its performance in avoiding not only static obstacles but also moving obstacles, without knowing the nature of the obstacle motion. The use ofregime switching in the avoidance of obstacles with unknown motion is particularly innovative.  The developed approach is applied to a homecare robot in computer simulation. The results show that the online path planner with Q-learning is able torapidly and successfully converge to the correct path.

  7. Critical path method applied to research project planning: Fire Economics Evaluation System (FEES)

    Science.gov (United States)

    Earl B. Anderson; R. Stanton Hales

    1986-01-01

    The critical path method (CPM) of network analysis (a) depicts precedence among the many activities in a project by a network diagram; (b) identifies critical activities by calculating their starting, finishing, and float times; and (c) displays possible schedules by constructing time charts. CPM was applied to the development of the Forest Service's Fire...

  8. Multi Robot Path Planning for Budgeted Active Perception with Self-Organising Maps

    Science.gov (United States)

    2016-10-04

    5], [6], [7], but the formulations have been limited to restricted cases, such as a single object or a constrained action space. Little attention has...solution paths. Object parts are shown in the coloured point clouds. Viewpoint regions are coloured black (low reward), orange (medium) and yellow (high

  9. 29 CFR 2580.412-2 - Plans exempt from the coverage of section 13.

    Science.gov (United States)

    2010-07-01

    ... whole or in part, of dealing with employers concerning an employee welfare or pension benefit plan, or... Section 2580.412-2 Labor Regulations Relating to Labor (Continued) EMPLOYEE BENEFITS SECURITY ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY BONDING RULES UNDER THE EMPLOYEE RETIREMENT INCOME SECURITY ACT OF...

  10. Efficient Kinect Sensor-Based Reactive Path Planning Method for Autonomous Mobile Robots in Dynamic Environments

    Energy Technology Data Exchange (ETDEWEB)

    Tuvshinjargal, Doopalam; Lee, Deok Jin [Kunsan National University, Gunsan (Korea, Republic of)

    2015-06-15

    In this paper, an efficient dynamic reactive motion planning method for an autonomous vehicle in a dynamic environment is proposed. The purpose of the proposed method is to improve the robustness of autonomous robot motion planning capabilities within dynamic, uncertain environments by integrating a virtual plane-based reactive motion planning technique with a sensor fusion-based obstacle detection approach. The dynamic reactive motion planning method assumes a local observer in the virtual plane, which allows the effective transformation of complex dynamic planning problems into simple stationary ones proving the speed and orientation information between the robot and obstacles. In addition, the sensor fusion-based obstacle detection technique allows the pose estimation of moving obstacles using a Kinect sensor and sonar sensors, thus improving the accuracy and robustness of the reactive motion planning approach. The performance of the proposed method was demonstrated through not only simulation studies but also field experiments using multiple moving obstacles in hostile dynamic environments.

  11. Efficient Kinect Sensor-Based Reactive Path Planning Method for Autonomous Mobile Robots in Dynamic Environments

    International Nuclear Information System (INIS)

    Tuvshinjargal, Doopalam; Lee, Deok Jin

    2015-01-01

    In this paper, an efficient dynamic reactive motion planning method for an autonomous vehicle in a dynamic environment is proposed. The purpose of the proposed method is to improve the robustness of autonomous robot motion planning capabilities within dynamic, uncertain environments by integrating a virtual plane-based reactive motion planning technique with a sensor fusion-based obstacle detection approach. The dynamic reactive motion planning method assumes a local observer in the virtual plane, which allows the effective transformation of complex dynamic planning problems into simple stationary ones proving the speed and orientation information between the robot and obstacles. In addition, the sensor fusion-based obstacle detection technique allows the pose estimation of moving obstacles using a Kinect sensor and sonar sensors, thus improving the accuracy and robustness of the reactive motion planning approach. The performance of the proposed method was demonstrated through not only simulation studies but also field experiments using multiple moving obstacles in hostile dynamic environments

  12. Critical path method as the criterion for optimization of business planning process

    OpenAIRE

    Butsenko Elena V.

    2016-01-01

    In today's economy the task of improving business planning is considered a necessary component of any enterprise management process and is precisely the solution drawn from that task which determines the financial policy and economic structure. The development of technologies based on the optimization of business planning is a very urgent scientific challenge. In this paper we propose to use the methods of network planning and management as a tool for economic and mathematical modeling to...

  13. Global Coverage Measurement Planning Strategies for Mobile Robots Equipped with a Remote Gas Sensor

    Directory of Open Access Journals (Sweden)

    Muhammad Asif Arain

    2015-03-01

    Full Text Available The problem of gas detection is relevant to many real-world applications, such as leak detection in industrial settings and landfill monitoring. In this paper, we address the problem of gas detection in large areas with a mobile robotic platform equipped with a remote gas sensor. We propose an algorithm that leverages a novel method based on convex relaxation for quickly solving sensor placement problems, and for generating an efficient exploration plan for the robot. To demonstrate the applicability of our method to real-world environments, we performed a large number of experimental trials, both on randomly generated maps and on the map of a real environment. Our approach proves to be highly efficient in terms of computational requirements and to provide nearly-optimal solutions.

  14. A biomimetic, energy-harvesting, obstacle-avoiding, path-planning algorithm for UAVs

    Science.gov (United States)

    Gudmundsson, Snorri

    This dissertation presents two new approaches to energy harvesting for Unmanned Aerial Vehicles (UAV). One method is based on the Potential Flow Method (PFM); the other method seeds a wind-field map based on updraft peak analysis and then applies a variant of the Bellman-Ford algorithm to find the minimum-cost path. Both methods are enhanced by taking into account the performance characteristics of the aircraft using advanced performance theory. The combined approach yields five possible trajectories from which the one with the minimum energy cost is selected. The dissertation concludes by using the developed theory and modeling tools to simulate the flight paths of two small Unmanned Aerial Vehicles (sUAV) in the 500 kg and 250 kg class. The results show that, in mountainous regions, substantial energy can be recovered, depending on topography and wind characteristics. For the examples presented, as much as 50% of the energy was recovered for a complex, multi-heading, multi-altitude, 170 km mission in an average wind speed of 9 m/s. The algorithms constitute a Generic Intelligent Control Algorithm (GICA) for autonomous unmanned aerial vehicles that enables an extraction of atmospheric energy while completing a mission trajectory. At the same time, the algorithm. automatically adjusts the flight path in order to avoid obstacles, in a fashion not unlike what one would expect from living organisms, such as birds and insects. This multi-disciplinary approach renders the approach biomimetic, i.e. it constitutes a synthetic system that “mimics the formation and function of biological mechanisms and processes.”.

  15. Plans to Observe the 2017 Total Solar Eclipse from near the Path Edges

    Science.gov (United States)

    Waring Dunham, David; Nugent, Richard; Guhl, Konrad; Bode, Hans-Joachim

    2015-08-01

    The August 21st, 2017 solar eclipse provides a good opportunity, to time the totality contacts, other Baily’s bead phenomena, and observe other dynamic edge phenomena, from locations near the edges of the path of totality. A good network of roads and generally favorable weather prospects means that more observers will likely be able to deploy more equipment than during most previous eclipses. The value of contact and Baily’s bead timings of total solar eclipses, for determining solar diameter and intensity variations, was described in an earlier presentation in Focus Meeting 13. This presentation will concentrate on how observations of different types that have been used during past eclipses can be made by different observers, to obtain better information about the accuracy of the different types of observations for determining the mean solar diameter, and the systematic differences between them. A problem has been that the few observers who have attempted recording Baily’s beads from path edge locations have wanted to use the latest technology, to try to record the observations better, rather than try to make the observations in the same ways that were used for many past eclipses. Several observers trying different techniques at the same location, and doing that at several locations at different places along the path, is needed. Past techniques that we would like to compare include direct visual observation (but keeping eye safety in mind); visual observation of telescopically projected images; direct filtered video telescopic observations; and recording the flash spectrum. There are several towns that straddle the path edges. The International Occultation Timing Association would like to mobilize people in those towns to observe the eclipse from many places, to say whether or not the eclipse happened, and if it did, time it. A suitable cell phone app could be designed to report observations, including the observer’s location, as was attempted for an

  16. Risk-Aware Planetary Rover Operation: Autonomous Terrain Classification and Path Planning

    Science.gov (United States)

    Ono, Masahiro; Fuchs, Thoams J.; Steffy, Amanda; Maimone, Mark; Yen, Jeng

    2015-01-01

    Identifying and avoiding terrain hazards (e.g., soft soil and pointy embedded rocks) are crucial for the safety of planetary rovers. This paper presents a newly developed groundbased Mars rover operation tool that mitigates risks from terrain by automatically identifying hazards on the terrain, evaluating their risks, and suggesting operators safe paths options that avoids potential risks while achieving specified goals. The tool will bring benefits to rover operations by reducing operation cost, by reducing cognitive load of rover operators, by preventing human errors, and most importantly, by significantly reducing the risk of the loss of rovers.

  17. Reaction-diffusion path planning in a hybrid chemical and cellular-automaton processor

    International Nuclear Information System (INIS)

    Adamatzky, Andrew; Lacy Costello, Benjamin de

    2003-01-01

    To find the shortest collision-free path in a room containing obstacles we designed a chemical processor and coupled it with a cellular-automaton processor. In the chemical processor obstacles are represented by sites of high concentration of potassium iodide and a planar substrate is saturated with palladium chloride. Potassium iodide diffuses into the substrate and reacts with palladium chloride. A dark coloured precipitate of palladium iodide is formed almost everywhere except sites where two or more diffusion wavefronts collide. The less coloured sites are situated at the furthest distance from obstacles. Thus, the chemical processor develops a repulsive field, generated by obstacles. A snapshot of the chemical processor is inputted to a cellular automaton. The automaton behaves like a discrete excitable media; also, every cell of the automaton is supplied with a pointer that shows an origin of the cell's excitation. The excitation spreads along the cells corresponding to precipitate depleted sites of the chemical processor. When the destination-site is excited, waves travel on the lattice and update the orientations of the pointers. Thus, the automaton constructs a spanning tree, made of pointers, that guides a traveler towards the destination point. Thus, the automaton medium generates an attractive field and combination of this attractive field with the repulsive field, generated by the chemical processor, provides us with a solution of the collision-free path problem

  18. Multi-scale path planning for reduced environmental impact of aviation

    Science.gov (United States)

    Campbell, Scot Edward

    A future air traffic management system capable of rerouting aircraft trajectories in real-time in response to transient and evolving events would result in increased aircraft efficiency, better utilization of the airspace, and decreased environmental impact. Mixed-integer linear programming (MILP) is used within a receding horizon framework to form aircraft trajectories which mitigate persistent contrail formation, avoid areas of convective weather, and seek a minimum fuel solution. Areas conducive to persistent contrail formation and areas of convective weather occur at disparate temporal and spatial scales, and thereby require the receding horizon controller to be adaptable to multi-scale events. In response, a novel adaptable receding horizon controller was developed to account for multi-scale disturbances, as well as generate trajectories using both a penalty function approach for obstacle penetration and hard obstacle avoidance constraints. A realistic aircraft fuel burn model based on aircraft data and engine performance simulations is used to form the cost function in the MILP optimization. The performance of the receding horizon algorithm is tested through simulation. A scalability analysis of the algorithm is conducted to ensure the tractability of the path planner. The adaptable receding horizon algorithm is shown to successfully negotiate multi-scale environments with performance exceeding static receding horizon solutions. The path planner is applied to realistic scenarios involving real atmospheric data. A single flight example for persistent contrail mitigation shows that fuel burn increases 1.48% when approximately 50% of persistent contrails are avoided, but 6.19% when 100% of persistent contrails are avoided. Persistent contrail mitigating trajectories are generated for multiple days of data, and the research shows that 58% of persistent contrails are avoided with a 0.48% increase in fuel consumption when averaged over a year.

  19. [Trends in the use of medical and dental services and associations with educational level and private health plan coverage in Brazil, 1998-2013].

    Science.gov (United States)

    Pilotto, Luciane Maria; Celeste, Roger Keller

    2018-03-29

    The public-private mix in the Brazilian health system favors double coverage of health services for individuals with private health plans and may aggravate inequities in the use of services. The aim of this study was to describe trends in the use of medical and dental services and associations with schooling and private health coverage. Data were obtained from a national household survey with representative samples in the years 1998, 2003, 2008, and 2013. The study described trends in the use of health services by adults, adjusted by private health coverage, years of schooling, sex, and age. There was an upward trend in the use of health services in adults without a private plan and among adults with a private plan the trend in use varied in a non-linear way. The medical service presented alternation in use over the years and the dental service showed a tendency to decline after 2003. It is necessary to monitor trends in private health coverage and the use of health services to assist government in regulating private plans and avoid increasing inequities among citizens in access to and use of health services.

  20. Dosimetric comparison of stereotactic body radiotherapy using 4D CT and multiphase CT images for treatment planning of lung cancer: Evaluation of the impact on daily dose coverage

    International Nuclear Information System (INIS)

    Wang Lu; Hayes, Shelly; Paskalev, Kamen; Jin Lihui; Buyyounouski, Mark K.; Ma, Charlie C.-M.; Feigenberg, Steve

    2009-01-01

    Purpose: To investigate the dosimetric impact of using 4D CT and multiphase (helical) CT images for treatment planning target definition and the daily target coverage in hypofractionated stereotactic body radiotherapy (SBRT) of lung cancer. Materials and methods: For 10 consecutive patients treated with SBRT, a set of 4D CT images and three sets of multiphase helical CT scans, taken during free-breathing, end-inspiration and end-expiration breath-hold, were obtained. Three separate planning target volumes (PTVs) were created from these image sets. A PTV 4D was created from the maximum intensity projection (MIP) reconstructed 4D images by adding a 3 mm margin to the internal target volume (ITV). A PTV 3CT was created by generating ITV from gross target volumes (GTVs) contoured from the three multiphase images. Finally, a third conventional PTV (denoted PTV conv ) was created by adding 5 mm in the axial direction and 10 mm in the longitudinal direction to the GTV (in this work, GTV = CTV = clinical target volume) generated from free-breathing helical CT scans. Treatment planning was performed based on PTV 4D (denoted as Plan-1), and the plan was adopted for PTV 3CT and PTV conv to form Plan-2 and Plan-3, respectively, by superimposing 'Plan-1' onto the helical free-breathing CT data set using modified beam apertures that conformed to either PTV 3CT or PTV conv . We first studied the impact of PTV design on treatment planning by evaluating the dosimetry of the three PTVs under the three plans, respectively. Then we examined the effect of the PTV designs on the daily target coverage by utilizing pre-treatment localization CT (CT-on-rails) images for daily GTV contouring and dose recalculation. The changes in the dose parameters of D 95 and D 99 (the dose received by 95% and 99% of the target volume, respectively), and the V p (the volume receiving the prescription dose) of the daily GTVs were compared under the three plans before and after setup error correction

  1. Path Planning of Mobile Elastic Robotic Arms by Indirect Approach of Optimal Control

    Directory of Open Access Journals (Sweden)

    Moharam Habibnejad Korayem

    2011-03-01

    Full Text Available Finding optimal trajectory is critical in several applications of robot manipulators. This paper is applied the open-loop optimal control approach for generating the optimal trajectory of the flexible mobile manipulators in point-to-point motion. This method is based on the Pontryagin-s minimum principle that by providing a two-point boundary value problem is solved the problem. This problem is known to be complex in particular when combined motion of the base and manipulator, non-holonomic constraint of the base and highly non-linear and complicated dynamic equations as a result of flexible nature of links are taken into account. The study emphasizes on modeling of the complete optimal control problem by remaining all nonlinear state and costate variables as well as control constraints. In this method, designer can compromise between different objectives by considering the proper penalty matrices and it yields to choose the proper trajectory among the various paths. The effectiveness and capability of the proposed approach are demonstrated through simulation studies. Finally, to verify the proposed method, the simulation results obtained from the model are compared with the results of those available in the literature.

  2. A path planning method for robot end effector motion using the curvature theory of the ruled surfaces

    Science.gov (United States)

    Güler, Fatma; Kasap, Emin

    Using the curvature theory for the ruled surfaces a technique for robot trajectory planning is presented. This technique ensures the calculation of robot’s next path. The positional variation of the Tool Center Point (TCP), linear velocity, angular velocity are required in the work area of the robot. In some circumstances, it may not be physically achievable and a re-computation of the robot trajectory might be necessary. This technique is suitable for re-computation of the robot trajectory. We obtain different robot trajectories which change depending on the darboux angle function and define trajectory ruled surface family with a common trajectory curve with the rotation trihedron. Also, the motion of robot end effector is illustrated with examples.

  3. Optimal multi-agent path planning for fast inverse modeling in UAV-based flood sensing applications

    KAUST Repository

    Abdelkader, Mohamed

    2014-05-01

    Floods are the most common natural disasters, causing thousands of casualties every year in the world. In particular, flash flood events are particularly deadly because of the short timescales on which they occur. Unmanned air vehicles equipped with mobile microsensors could be capable of sensing flash floods in real time, saving lives and greatly improving the efficiency of the emergency response. However, of the main issues arising with sensing floods is the difficulty of planning the path of the sensing agents in advance so as to obtain meaningful data as fast as possible. In this particle, we present a fast numerical scheme to quickly compute the trajectories of a set of UAVs in order to maximize the accuracy of model parameter estimation over a time horizon. Simulation results are presented, a preliminary testbed is briefly described, and future research directions and problems are discussed. © 2014 IEEE.

  4. Pedestrian flow-path modeling to support tsunami evacuation and disaster relief planning in the U.S. Pacific Northwest

    Science.gov (United States)

    Wood, Nathan J.; Jones, Jeanne M.; Schmidtlein, Mathew; Schelling, John; Frazier, T.

    2016-01-01

    Successful evacuations are critical to saving lives from future tsunamis. Pedestrian-evacuation modeling related to tsunami hazards primarily has focused on identifying areas and the number of people in these areas where successful evacuations are unlikely. Less attention has been paid to identifying evacuation pathways and population demand at assembly areas for at-risk individuals that may have sufficient time to evacuate. We use the neighboring coastal communities of Hoquiam, Aberdeen, and Cosmopolis (Washington, USA) and the local tsunami threat posed by Cascadia subduction zone earthquakes as a case study to explore the use of geospatial, least-cost-distance evacuation modeling for supporting evacuation outreach, response, and relief planning. We demonstrate an approach that uses geospatial evacuation modeling to (a) map the minimum pedestrian travel speeds to safety, the most efficient paths, and collective evacuation basins, (b) estimate the total number and demographic description of evacuees at predetermined assembly areas, and (c) determine which paths may be compromised due to earthquake-induced ground failure. Results suggest a wide range in the magnitude and type of evacuees at predetermined assembly areas and highlight parts of the communities with no readily accessible assembly area. Earthquake-induced ground failures could obstruct access to some assembly areas, cause evacuees to reroute to get to other assembly areas, and isolate some evacuees from relief personnel. Evacuation-modeling methods and results discussed here have implications and application to tsunami-evacuation outreach, training, response procedures, mitigation, and long-term land use planning to increase community resilience.

  5. Predicting Climate-sensitive Infectious Diseases: Development of a Federal Science Plan and the Path Forward

    Science.gov (United States)

    Trtanj, J.; Balbus, J. M.; Brown, C.; Shimamoto, M. M.

    2017-12-01

    The transmission and spread of infectious diseases, especially vector-borne diseases, water-borne diseases and zoonosis, are influenced by short and long-term climate factors, in conjunction with numerous other drivers. Public health interventions, including vaccination, vector control programs, and outreach campaigns could be made more effective if the geographic range and timing of increased disease risk could be more accurately targeted, and high risk areas and populations identified. While some progress has been made in predictive modeling for transmission of these diseases using climate and weather data as inputs, they often still start after the first case appears, the skill of those models remains limited, and their use by public health officials infrequent. And further, predictions with lead times of weeks, months or seasons are even rarer, yet the value of acting early holds the potential to save more lives, reduce cost and enhance both economic and national security. Information on high-risk populations and areas for infectious diseases is also potentially useful for the federal defense and intelligence communities as well. The US Global Change Research Program, through its Interagency Group on Climate Change and Human Health (CCHHG), has put together a science plan that pulls together federal scientists and programs working on predictive modeling of climate-sensitive diseases, and draws on academic and other partners. Through a series of webinars and an in-person workshop, the CCHHG has convened key federal and academic stakeholders to assess the current state of science and develop an integrated science plan to identify data and observation systems needs as well as a targeted research agenda for enhancing predictive modeling. This presentation will summarize the findings from this effort and engage AGU members on plans and next steps to improve predictive modeling for infectious diseases.

  6. High ANC coverage and low skilled attendance in a rural Tanzanian district: a case for implementing a birth plan intervention

    Directory of Open Access Journals (Sweden)

    Cousens Simon

    2010-03-01

    Full Text Available Abstract Background In Tanzania, more than 90% of all pregnant women attend antenatal care at least once and approximately 62% four times or more, yet less than five in ten receive skilled delivery care at available health units. We conducted a qualitative study in Ngorongoro district, Northern Tanzania, in order to gain an understanding of the health systems and socio-cultural factors underlying this divergent pattern of high use of antenatal services and low use of skilled delivery care. Specifically, the study examined beliefs and behaviors related to antenatal, labor, delivery and postnatal care among the Maasai and Watemi ethnic groups. The perspectives of health care providers and traditional birth attendants on childbirth and the factors determining where women deliver were also investigated. Methods Twelve key informant interviews and fifteen focus group discussions were held with Maasai and Watemi women, traditional birth attendants, health care providers, and community members. Principles of the grounded theory approach were used to elicit and assess the various perspectives of each group of participants interviewed. Results The Maasai and Watemi women's preferences for a home birth and lack of planning for delivery are reinforced by the failure of health care providers to consistently communicate the importance of skilled delivery and immediate post-partum care for all women during routine antenatal visits. Husbands typically serve as gatekeepers of women's reproductive health in the two groups - including decisions about where they will deliver- yet they are rarely encouraged to attend antenatal sessions. While husbands are encouraged to participate in programs to prevent maternal-to-child transmission of HIV, messages about the importance of skilled delivery care for all women are not given emphasis. Conclusions Increasing coverage of skilled delivery care and achieving the full implementation of Tanzania's Focused Antenatal Care

  7. High ANC coverage and low skilled attendance in a rural Tanzanian district: a case for implementing a birth plan intervention.

    Science.gov (United States)

    Magoma, Moke; Requejo, Jennifer; Campbell, Oona M R; Cousens, Simon; Filippi, Veronique

    2010-03-19

    In Tanzania, more than 90% of all pregnant women attend antenatal care at least once and approximately 62% four times or more, yet less than five in ten receive skilled delivery care at available health units. We conducted a qualitative study in Ngorongoro district, Northern Tanzania, in order to gain an understanding of the health systems and socio-cultural factors underlying this divergent pattern of high use of antenatal services and low use of skilled delivery care. Specifically, the study examined beliefs and behaviors related to antenatal, labor, delivery and postnatal care among the Maasai and Watemi ethnic groups. The perspectives of health care providers and traditional birth attendants on childbirth and the factors determining where women deliver were also investigated. Twelve key informant interviews and fifteen focus group discussions were held with Maasai and Watemi women, traditional birth attendants, health care providers, and community members. Principles of the grounded theory approach were used to elicit and assess the various perspectives of each group of participants interviewed. The Maasai and Watemi women's preferences for a home birth and lack of planning for delivery are reinforced by the failure of health care providers to consistently communicate the importance of skilled delivery and immediate post-partum care for all women during routine antenatal visits. Husbands typically serve as gatekeepers of women's reproductive health in the two groups - including decisions about where they will deliver- yet they are rarely encouraged to attend antenatal sessions. While husbands are encouraged to participate in programs to prevent maternal-to-child transmission of HIV, messages about the importance of skilled delivery care for all women are not given emphasis. Increasing coverage of skilled delivery care and achieving the full implementation of Tanzania's Focused Antenatal Care Package in Ngorongoro depends upon improved training and monitoring of

  8. Interactive computation of coverage regions for indoor wireless communication

    Science.gov (United States)

    Abbott, A. Lynn; Bhat, Nitin; Rappaport, Theodore S.

    1995-12-01

    This paper describes a system which assists in the strategic placement of rf base stations within buildings. Known as the site modeling tool (SMT), this system allows the user to display graphical floor plans and to select base station transceiver parameters, including location and orientation, interactively. The system then computes and highlights estimated coverage regions for each transceiver, enabling the user to assess the total coverage within the building. For single-floor operation, the user can choose between distance-dependent and partition- dependent path-loss models. Similar path-loss models are also available for the case of multiple floors. This paper describes the method used by the system to estimate coverage for both directional and omnidirectional antennas. The site modeling tool is intended to be simple to use by individuals who are not experts at wireless communication system design, and is expected to be very useful in the specification of indoor wireless systems.

  9. RISK ASSESSMENT IN PROJECT PLANNING USING FMEA AND CRITICAL PATH METHOD

    Directory of Open Access Journals (Sweden)

    Sandra Milena CHOLES ARVILLA

    2014-10-01

    Full Text Available This paper is based upon the research undertaken for the development of the doctoral thesis “Management of software projects based on object-oriented technology”. The study examines the existing risk management practices commonly used for classic software development. The goal is to integrate the elements of the traditional risk management methodologies to create a new agile risk management methodology. The thesis focuses on techniques that can be easily implemented in extreme programming (XP and SCRUM. This study is motivated by the following research questions: What are the elements of existing quality assurance tools that could meet the principles of agile development? And is it possible to use risk estimation for improving quality in agile projects? The thesis presents a synthesis of the most common risk management techniques, as well as an introduction to agile methods XP and SCRUM. The proposal integrates the concepts of Failure Mode and Effect Analysis into the iterative life cycle of an agile software project. The thesis presents a metamodel which integrates the concepts of agile development methodologies: SCRUM and XP with the FMEA concepts for risk quantification. The model was partly implemented into a real development project. Partial results show the improvement in early identification of failures and allowed to reconsider the Sprint plan.

  10. Trajectory planning and test for all coverage, automatic and uniform feeding in river crab aquaculture%河蟹养殖全覆盖自动均匀投饲的轨迹规划与试验

    Institute of Scientific and Technical Information of China (English)

    孙月平; 赵德安; 洪剑青; 张军; 李发忠; 罗吉

    2016-01-01

    of optimal calculation trajectory planning were better than that of traditional empirical estimation trajectory planning when feeding system worked with the parameters respectively. For the optimal calculation trajectory planning, corresponding total path length was 235.39 m, feeding path length was 195.16 m, total working time was 789.10 s, feed average density was 8.85 g/m2, and feeding coverage rate was 86.84%. Feeding contrast tests between traditional empirical estimation trajectory planning and optimal calculation trajectory planning were performed in Jiangsu University in April 2016. Results showed that experimental trajectories of workboat using the 2 groups of parameters both had only small offsets with the planned trajectories, which were consistent with the simulation results, and all feeding performance indices of optimal calculation trajectory planning were better than that of traditional empirical estimation trajectory planning. For the optimal calculation trajectory planning, corresponding practical total path length was 251.52 m, feeding path length was 200.45 m, total working time was 868.5 s, feeding time was 501.1 s, feed average density was 8.58 g/m2, and feeding coverage rate was 88.46%. And the relative error was 6.85%, 2.71%, 10.07%, 10.41%, 3.06% and 1.87% when comparing with the simulation results respectively, which showed the feasibility of the coverage trajectory planning method. Furthermore, trajectory planning verification simulation on another larger river crab pond of 15 057.56 m2 was performed, which corroborated that the automatic coverage trajectory planning system was also effective and applicable for large area river crab pond. The system could generate feeding trajectory directly and automatically when getting vertex coordinates of pond area, which would improve the accuracy and efficiency of trajectory planning, guarantee the uniform feeding and increase the economic benefits. This research provides technology reference for

  11. Health insurance coverage and use of family planning services among current and former foster youth: implications of the health care reform law.

    Science.gov (United States)

    Dworsky, Amy; Ahrens, Kym; Courtney, Mark

    2013-04-01

    This research uses data from a longitudinal study to examine how two provisions in the Patient Protection and Affordable Care Act could affect health insurance coverage among young women who have aged out of foster care. It also explores how allowing young people to remain in foster care until age twenty-one affects their health insurance coverage, use of family planning services, and information about birth control. We find that young women are more likely to have health insurance if they remain in foster care until their twenty-first birthday and that having health insurance is associated with an increase in the likelihood of receiving family planning services. Our results also suggest that many young women who would otherwise lack health insurance after aging out of foster care will be eligible for Medicaid under the health care reform law. Because having health insurance is associated with use of family planning services, this increase in Medicaid eligibility may result in fewer unintended pregnancies among this high-risk population.

  12. Planning the base station layout in UMTS urban scenarios: a simulation approach to coverage and capacity estimation

    OpenAIRE

    Zola, Enrica Valeria; Barceló Arroyo, Francisco

    2004-01-01

    This paper analyzes the performance of a base station layout for a UMTS network in a densely populated city. The study is carried out using snapshot simulations of an actual city (Barcelona, Spain) with specific traffic and propagation profiles. A first layout is proposed in order to guarantee good coverage with a minimum number of base stations. This layout is approached taking into account the link budget analytical calculations and the first simulation results for a single-cell environment...

  13. 视觉移动机器人的模糊智能路径规划%Intelligent Path Planning of Vision- Based Mobile Robot with Fuzzy Approach

    Institute of Scientific and Technical Information of China (English)

    张一巍; 黄源清

    2002-01-01

    The path planning problem for intelligent mobile robots inwbves two main problems: the represent of task emionment including obstacles and the development of a strategy to determine a collision - free route. In this paper, new approaches have been developed to solve these problems .The first problem was solve using the fuzzy system approach, which represent obstacles with a circle. The other problem was overcome throughthe use of a strategy selector, which chooses the best stategy between velocity control strategy and direction control strategy.

  14. 76 FR 46621 - Group Health Plans and Health Insurance Issuers Relating to Coverage of Preventive Services Under...

    Science.gov (United States)

    2011-08-03

    ... to the interim final regulations implementing the rules for group health plans and health insurance... dates. These interim final regulations generally apply to group health plans and group health insurance... from HHS on private health insurance for consumers can be found on the Centers for Medicare & Medicaid...

  15. Path Dependency

    OpenAIRE

    Mark Setterfield

    2015-01-01

    Path dependency is defined, and three different specific concepts of path dependency – cumulative causation, lock in, and hysteresis – are analyzed. The relationships between path dependency and equilibrium, and path dependency and fundamental uncertainty are also discussed. Finally, a typology of dynamical systems is developed to clarify these relationships.

  16. Path Planning for Mobile Objects in Four-Dimension Based on Particle Swarm Optimization Method with Penalty Function

    Directory of Open Access Journals (Sweden)

    Yong Ma

    2013-01-01

    Full Text Available We present one algorithm based on particle swarm optimization (PSO with penalty function to determine the conflict-free path for mobile objects in four-dimension (three spatial and one-time dimensions with obstacles. The shortest path of the mobile object is set as goal function, which is constrained by conflict-free criterion, path smoothness, and velocity and acceleration requirements. This problem is formulated as a calculus of variation problem (CVP. With parametrization method, the CVP is converted to a time-varying nonlinear programming problem (TNLPP. Constraints of TNLPP are transformed to general TNLPP without any constraints through penalty functions. Then, by using a little calculations and applying the algorithm PSO, the solution of the CVP is consequently obtained. Approach efficiency is confirmed by numerical examples.

  17. Percent Coverage

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Percent Coverage is a spreadsheet that keeps track of and compares the number of vessels that have departed with and without observers to the numbers of vessels...

  18. 75 FR 70114 - Amendment to the Interim Final Rules for Group Health Plans and Health Insurance Coverage...

    Science.gov (United States)

    2010-11-17

    ... HEALTH AND HUMAN SERVICES Office of Consumer Information and Insurance Oversight 45 CFR Part 147 RIN 0950-AA17 [OCIIO-9991-IFC2] Amendment to the Interim Final Rules for Group Health Plans and Health Insurance... Administration, Department of Labor; Office of Consumer Information and Insurance Oversight, Department of Health...

  19. A Plan for the Development of Fusion Energy. Final Report to Fusion Energy Sciences Advisory Committee, Fusion Development Path Panel

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2003-03-05

    This report presents a plan for the deployment of a fusion demonstration power plant within 35 years, leading to commercial application of fusion energy by mid-century. The plan is derived from the necessary features of a demonstration fusion power plant and from the time scale defined by President Bush. It identifies critical milestones, key decision points, needed major facilities and required budgets.

  20. An adaptive dual-optimal path-planning technique for unmanned air vehicles with application to solar-regenerative high altitude long endurance flight

    Science.gov (United States)

    Whitfield, Clifford A.

    2009-12-01

    A multi-objective technique for Unmanned Air Vehicle (UAV) path and trajectory autonomy generation, through task allocation and sensor fusion has been developed. The Dual-Optimal Path-Planning (D-O.P-P.) Technique generates on-line adaptive flight paths for UAVs based on available flight windows and environmental influenced objectives. The environmental influenced optimal condition, known as the driver' determines the condition, within a downstream virtual window of possible vehicle destinations and orientation built from the UAV kinematics. The intermittent results are pursued by a dynamic optimization technique to determine the flight path. This sequential optimization technique is a multi-objective optimization procedure consisting of two goals, without requiring additional information to combine the conflicting objectives into a single-objective. An example case-study and additional applications are developed and the results are discussed; including the application to the field of Solar Regenerative (SR) High Altitude Long Endurance (HALE) UAV flight. Harnessing solar energy has recently been adapted for use on high altitude UAV platforms. An aircraft that uses solar panels and powered by the sun during the day and through the night by SR systems, in principle could sustain flight for weeks or months. The requirements and limitations of solar powered flight were determined. The SR-HALE UAV platform geometry and flight characteristics were selected from an existing aircraft that has demonstrated the capability for sustained flight through flight tests. The goals were to maintain continual Situational Awareness (SA) over a case-study selected Area of Interest (AOI) and existing UAV power and surveillance systems. This was done for still wind and constant wind conditions at altitude along with variations in latitude. The characteristics of solar flux and the dependence on the surface location and orientation were established along with fixed flight maneuvers for

  1. Space Shuttle Communications Coverage Analysis for Thermal Tile Inspection

    Science.gov (United States)

    Kroll, Quin D.; Hwu, Shian U.; Upanavage, Matthew; Boster, John P.; Chavez, Mark A.

    2009-01-01

    The space shuttle ultra-high frequency Space-to-Space Communication System has to provide adequate communication coverage for astronauts who are performing thermal tile inspection and repair on the underside of the space shuttle orbiter (SSO). Careful planning and quantitative assessment are necessary to ensure successful system operations and mission safety in this work environment. This study assesses communication systems performance for astronauts who are working in the underside, non-line-of-sight shadow region on the space shuttle. All of the space shuttle and International Space Station (ISS) transmitting antennas are blocked by the SSO structure. To ensure communication coverage at planned inspection worksites, the signal strength and link margin between the SSO/ISS antennas and the extravehicular activity astronauts, whose line-of-sight is blocked by vehicle structure, was analyzed. Investigations were performed using rigorous computational electromagnetic modeling techniques. Signal strength was obtained by computing the reflected and diffracted fields along the signal propagation paths between transmitting and receiving antennas. Radio frequency (RF) coverage was determined for thermal tile inspection and repair missions using the results of this computation. Analysis results from this paper are important in formulating the limits on reliable communication range and RF coverage at planned underside inspection and repair worksites.

  2. Functional coverages

    NARCIS (Netherlands)

    Donchyts, G.; Baart, F.; Jagers, H.R.A.; Van Dam, A.

    2011-01-01

    A new Application Programming Interface (API) is presented which simplifies working with geospatial coverages as well as many other data structures of a multi-dimensional nature. The main idea extends the Common Data Model (CDM) developed at the University Corporation for Atmospheric Research

  3. Path Expressions

    Science.gov (United States)

    1975-06-01

    Traditionally, synchronization of concurrent processes is coded in line by operations on semaphores or similar objects. Path expressions move the...discussion about a variety of synchronization primitives . An analysis of their relative power is found in [3]. Path expressions do not introduce yet...another synchronization primitive . A path expression relates to such primitives as a for- or while-statement of an ALGOL-like language relates to a JUMP

  4. A new optimization tool path planning for 3-axis end milling of free-form surfaces based on efficient machining intervals

    Science.gov (United States)

    Vu, Duy-Duc; Monies, Frédéric; Rubio, Walter

    2018-05-01

    A large number of studies, based on 3-axis end milling of free-form surfaces, seek to optimize tool path planning. Approaches try to optimize the machining time by reducing the total tool path length while respecting the criterion of the maximum scallop height. Theoretically, the tool path trajectories that remove the most material follow the directions in which the machined width is the largest. The free-form surface is often considered as a single machining area. Therefore, the optimization on the entire surface is limited. Indeed, it is difficult to define tool trajectories with optimal feed directions which generate largest machined widths. Another limiting point of previous approaches for effectively reduce machining time is the inadequate choice of the tool. Researchers use generally a spherical tool on the entire surface. However, the gains proposed by these different methods developed with these tools lead to relatively small time savings. Therefore, this study proposes a new method, using toroidal milling tools, for generating toolpaths in different regions on the machining surface. The surface is divided into several regions based on machining intervals. These intervals ensure that the effective radius of the tool, at each cutter-contact points on the surface, is always greater than the radius of the tool in an optimized feed direction. A parallel plane strategy is then used on the sub-surfaces with an optimal specific feed direction for each sub-surface. This method allows one to mill the entire surface with efficiency greater than with the use of a spherical tool. The proposed method is calculated and modeled using Maple software to find optimal regions and feed directions in each region. This new method is tested on a free-form surface. A comparison is made with a spherical cutter to show the significant gains obtained with a toroidal milling cutter. Comparisons with CAM software and experimental validations are also done. The results show the

  5. Using meta-analytic path analysis to test theoretical predictions in health behavior: An illustration based on meta-analyses of the theory of planned behavior.

    Science.gov (United States)

    Hagger, Martin S; Chan, Derwin K C; Protogerou, Cleo; Chatzisarantis, Nikos L D

    2016-08-01

    Synthesizing research on social cognitive theories applied to health behavior is an important step in the development of an evidence base of psychological factors as targets for effective behavioral interventions. However, few meta-analyses of research on social cognitive theories in health contexts have conducted simultaneous tests of theoretically-stipulated pattern effects using path analysis. We argue that conducting path analyses of meta-analytic effects among constructs from social cognitive theories is important to test nomological validity, account for mediation effects, and evaluate unique effects of theory constructs independent of past behavior. We illustrate our points by conducting new analyses of two meta-analyses of a popular theory applied to health behaviors, the theory of planned behavior. We conducted meta-analytic path analyses of the theory in two behavioral contexts (alcohol and dietary behaviors) using data from the primary studies included in the original meta-analyses augmented to include intercorrelations among constructs and relations with past behavior missing from the original analysis. Findings supported the nomological validity of the theory and its hypotheses for both behaviors, confirmed important model processes through mediation analysis, demonstrated the attenuating effect of past behavior on theory relations, and provided estimates of the unique effects of theory constructs independent of past behavior. Our analysis illustrates the importance of conducting a simultaneous test of theory-stipulated effects in meta-analyses of social cognitive theories applied to health behavior. We recommend researchers adopt this analytic procedure when synthesizing evidence across primary tests of social cognitive theories in health. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Needle path planning and steering in a three-dimensional non-static environment using two-dimensional ultrasound images

    Science.gov (United States)

    Vrooijink, Gustaaf J.; Abayazid, Momen; Patil, Sachin; Alterovitz, Ron; Misra, Sarthak

    2015-01-01

    Needle insertion is commonly performed in minimally invasive medical procedures such as biopsy and radiation cancer treatment. During such procedures, accurate needle tip placement is critical for correct diagnosis or successful treatment. Accurate placement of the needle tip inside tissue is challenging, especially when the target moves and anatomical obstacles must be avoided. We develop a needle steering system capable of autonomously and accurately guiding a steerable needle using two-dimensional (2D) ultrasound images. The needle is steered to a moving target while avoiding moving obstacles in a three-dimensional (3D) non-static environment. Using a 2D ultrasound imaging device, our system accurately tracks the needle tip motion in 3D space in order to estimate the tip pose. The needle tip pose is used by a rapidly exploring random tree-based motion planner to compute a feasible needle path to the target. The motion planner is sufficiently fast such that replanning can be performed repeatedly in a closed-loop manner. This enables the system to correct for perturbations in needle motion, and movement in obstacle and target locations. Our needle steering experiments in a soft-tissue phantom achieves maximum targeting errors of 0.86 ± 0.35 mm (without obstacles) and 2.16 ± 0.88 mm (with a moving obstacle). PMID:26279600

  7. 42 CFR 440.330 - Benchmark health benefits coverage.

    Science.gov (United States)

    2010-10-01

    ...) Federal Employees Health Benefit Plan Equivalent Coverage (FEHBP—Equivalent Health Insurance Coverage). A... coverage. Health benefits coverage that is offered and generally available to State employees in the State... 42 Public Health 4 2010-10-01 2010-10-01 false Benchmark health benefits coverage. 440.330 Section...

  8. Planos privados de assistência à saúde: cobertura populacional no Brasil Private health plans: populational coverage in Brazil

    Directory of Open Access Journals (Sweden)

    Luiz Felipe Pinto

    2004-01-01

    Full Text Available Foram utilizados o Cadastro de Beneficiários da Agência Nacional de Saúde Suplementar (ANS e a Pesquisa Nacional por Amostra de Domicílios (PNAD/IBGE para descrever o perfil da cobertura dos serviços por planos privados de saúde. Apesar da regulação pela ANS, não se deve perder de vista que o acesso, a utilização e a cobertura populacional em planos de saúde precisam ser periodicamente monitorados, principalmente na região Sudeste, que concentra 70% da população coberta por planos de saúde. Também são necessários estudos mais detalhados sobre as capitais brasileiras, que constituem grandes centros de concentração de clientela; e investigações para os subgrupos etários que mais utilizam os serviços de saúde: crianças menores de 5 anos, mulheres em idade fértil e idosos. Os resultados do estudo indicam que, no Sistema de Saúde Brasileiro, os planos privados de assistência à saúde se configuram como mais um fator de geração de desigualdades sociais no acesso e na utilização de serviços de saúde, pois cobrem apenas uma parcela específica da população brasileira: pessoas de maior renda familiar, de cor branca, com maior nível de escolaridade, inseridas em determinados ramos de atividade do mercado de trabalho, moradores das capitais/regiões metropolitanas.The Beneficiaries' Frame from ANS and the data of the PNAD/IBGE have been used to describe the profile of the private health plans' coverage. Although the regulation functions of ANS, one should not forget that private health insurance access, use and coverage should be monitored continuously, specially the private market of Southeast Region, which concentrate 70% of coverage people in Brazil. Others studies are also necessary for Brazilian capitals, which constitute great urban cities of insurance people. Besides this, more detailed investigation must be developed for age groups with higher utilization of health services: children up to 5 years, women

  9. Euclidean shortest paths exact or approximate algorithms

    CERN Document Server

    Li, Fajie

    2014-01-01

    This book reviews algorithms for the exact or approximate solution of shortest-path problems, with a specific focus on a class of algorithms called rubberband algorithms. The coverage includes mathematical proofs for many of the given statements.

  10. National electricity planning in settings with low pre-existing grid coverage: Development of a spatial model and case study of Kenya

    International Nuclear Information System (INIS)

    Parshall, Lily; Pillai, Dana; Mohan, Shashank; Sanoh, Aly; Modi, Vijay

    2009-01-01

    We develop a spatial electricity planning model to guide grid expansion in countries with low pre-existing electricity coverage. The model can be used to rapidly estimate connection costs and compare different regions and communities. Inputs that are modeled include electricity demand, costs, and geographic characteristics. The spatial nature of the model permits accurate representation of the existing electricity network and population distribution, which form the basis for future expansion decisions. The methodology and model assumptions are illustrated using country-specific data from Kenya. Results show that under most geographic conditions, extension of the national grid is less costly than off-grid options. Based on realistic penetration rates for Kenya, we estimate an average connection cost of $1900 per household, with lower-cost connection opportunities around major cities and in denser rural regions. In areas with an adequate pre-existing medium-voltage backbone, we estimate that over 30% of households could be connected for less than $1000 per connection through infilling. The penetration rate, an exogenous factor chosen by electricity planners, is found to have a large effect on household connection costs, often outweighing socio-economic and spatial factors such as inter-household distance, per-household demand, and proximity to the national grid.

  11. A program-management plan with critical-path definition for Combustion Augmentation with Thermionic Energy Conversion (CATEC)

    Science.gov (United States)

    Morris, J. F.; Merrill, O. S.; Reddy, H. K.

    1981-01-01

    Thermionic energy conversion (TEC) is discussed. In recent TEC-topping analyses, overall plant efficiency (OPE) and cost of electricity (COE) improved slightly with current capabilities and substantially with fully matured technologies. Enhanced credibility derives from proven hot-corrosion protection for TEC by silicon-carbide clads in fossil fuel combustion products. Combustion augmentation with TEC (CATEC) affords minimal cost and plant perturbation, but with smaller OPE and COE improvements than more conventional topping applications. Risk minimization as well as comparative simplicity and convenience, favor CATEC for early market penetration. A program-management plan is proposed. Inputs, characteristics, outputs and capabilities are discussed.

  12. A program-management plan with critical-path definition for Combustion Augmentation with Thermionic Energy Conversion (CATEC)

    Science.gov (United States)

    Morris, J. F.; Merrill, O. S.; Reddy, H. K.

    Thermionic energy conversion (TEC) is discussed. In recent TEC-topping analyses, overall plant efficiency (OPE) and cost of electricity (COE) improved slightly with current capabilities and substantially with fully matured technologies. Enhanced credibility derives from proven hot-corrosion protection for TEC by silicon-carbide clads in fossil fuel combustion products. Combustion augmentation with TEC (CATEC) affords minimal cost and plant perturbation, but with smaller OPE and COE improvements than more conventional topping applications. Risk minimization as well as comparative simplicity and convenience, favor CATEC for early market penetration. A program-management plan is proposed. Inputs, characteristics, outputs and capabilities are discussed.

  13. Sensor-driven area coverage for an autonomous fixed-wing unmanned aerial vehicle.

    Science.gov (United States)

    Paull, Liam; Thibault, Carl; Nagaty, Amr; Seto, Mae; Li, Howard

    2014-09-01

    Area coverage with an onboard sensor is an important task for an unmanned aerial vehicle (UAV) with many applications. Autonomous fixed-wing UAVs are more appropriate for larger scale area surveying since they can cover ground more quickly. However, their non-holonomic dynamics and susceptibility to disturbances make sensor coverage a challenging task. Most previous approaches to area coverage planning are offline and assume that the UAV can follow the planned trajectory exactly. In this paper, this restriction is removed as the aircraft maintains a coverage map based on its actual pose trajectory and makes control decisions based on that map. The aircraft is able to plan paths in situ based on sensor data and an accurate model of the on-board camera used for coverage. An information theoretic approach is used that selects desired headings that maximize the expected information gain over the coverage map. In addition, the branch entropy concept previously developed for autonomous underwater vehicles is extended to UAVs and ensures that the vehicle is able to achieve its global coverage mission. The coverage map over the workspace uses the projective camera model and compares the expected area of the target on the ground and the actual area covered on the ground by each pixel in the image. The camera is mounted on a two-axis gimbal and can either be stabilized or optimized for maximal coverage. Hardware-in-the-loop simulation results and real hardware implementation on a fixed-wing UAV show the effectiveness of the approach. By including the already developed automatic takeoff and landing capabilities, we now have a fully automated and robust platform for performing aerial imagery surveys.

  14. A New Path-Constrained Rendezvous Planning Approach for Large-Scale Event-Driven Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Ahmadreza Vajdi

    2018-05-01

    Full Text Available We study the problem of employing a mobile-sink into a large-scale Event-Driven Wireless Sensor Networks (EWSNs for the purpose of data harvesting from sensor-nodes. Generally, this employment improves the main weakness of WSNs that is about energy-consumption in battery-driven sensor-nodes. The main motivation of our work is to address challenges which are related to a network’s topology by adopting a mobile-sink that moves in a predefined trajectory in the environment. Since, in this fashion, it is not possible to gather data from sensor-nodes individually, we adopt the approach of defining some of the sensor-nodes as Rendezvous Points (RPs in the network. We argue that RP-planning in this case is a tradeoff between minimizing the number of RPs while decreasing the number of hops for a sensor-node that needs data transformation to the related RP which leads to minimizing average energy consumption in the network. We address the problem by formulating the challenges and expectations as a Mixed Integer Linear Programming (MILP. Henceforth, by proving the NP-hardness of the problem, we propose three effective and distributed heuristics for RP-planning, identifying sojourn locations, and constructing routing trees. Finally, experimental results prove the effectiveness of our approach.

  15. A New Path-Constrained Rendezvous Planning Approach for Large-Scale Event-Driven Wireless Sensor Networks.

    Science.gov (United States)

    Vajdi, Ahmadreza; Zhang, Gongxuan; Zhou, Junlong; Wei, Tongquan; Wang, Yongli; Wang, Tianshu

    2018-05-04

    We study the problem of employing a mobile-sink into a large-scale Event-Driven Wireless Sensor Networks (EWSNs) for the purpose of data harvesting from sensor-nodes. Generally, this employment improves the main weakness of WSNs that is about energy-consumption in battery-driven sensor-nodes. The main motivation of our work is to address challenges which are related to a network’s topology by adopting a mobile-sink that moves in a predefined trajectory in the environment. Since, in this fashion, it is not possible to gather data from sensor-nodes individually, we adopt the approach of defining some of the sensor-nodes as Rendezvous Points (RPs) in the network. We argue that RP-planning in this case is a tradeoff between minimizing the number of RPs while decreasing the number of hops for a sensor-node that needs data transformation to the related RP which leads to minimizing average energy consumption in the network. We address the problem by formulating the challenges and expectations as a Mixed Integer Linear Programming (MILP). Henceforth, by proving the NP-hardness of the problem, we propose three effective and distributed heuristics for RP-planning, identifying sojourn locations, and constructing routing trees. Finally, experimental results prove the effectiveness of our approach.

  16. A New Path-Constrained Rendezvous Planning Approach for Large-Scale Event-Driven Wireless Sensor Networks

    Science.gov (United States)

    Zhang, Gongxuan; Wang, Yongli; Wang, Tianshu

    2018-01-01

    We study the problem of employing a mobile-sink into a large-scale Event-Driven Wireless Sensor Networks (EWSNs) for the purpose of data harvesting from sensor-nodes. Generally, this employment improves the main weakness of WSNs that is about energy-consumption in battery-driven sensor-nodes. The main motivation of our work is to address challenges which are related to a network’s topology by adopting a mobile-sink that moves in a predefined trajectory in the environment. Since, in this fashion, it is not possible to gather data from sensor-nodes individually, we adopt the approach of defining some of the sensor-nodes as Rendezvous Points (RPs) in the network. We argue that RP-planning in this case is a tradeoff between minimizing the number of RPs while decreasing the number of hops for a sensor-node that needs data transformation to the related RP which leads to minimizing average energy consumption in the network. We address the problem by formulating the challenges and expectations as a Mixed Integer Linear Programming (MILP). Henceforth, by proving the NP-hardness of the problem, we propose three effective and distributed heuristics for RP-planning, identifying sojourn locations, and constructing routing trees. Finally, experimental results prove the effectiveness of our approach. PMID:29734718

  17. A Piecewise Acceleration-Optimal and Smooth-Jerk Trajectory Planning Method for Robot Manipulator along a Predefined Path

    Directory of Open Access Journals (Sweden)

    Yuan Chen

    2011-09-01

    Full Text Available This paper proposes a piecewise acceleration-optimal and smooth-jerk trajectory planning method of robot manipulator. The optimal objective function is given by the weighted sum of two terms having opposite effects: the maximal acceleration and the minimal jerk. Some computing techniques are proposed to determine the optimal solution. These techniques take both the time intervals between two interpolation points and the control points of B-spline function as optimal variables, redefine the kinematic constraints as the constraints of optimal variables, and reformulate the objective function in matrix form. The feasibility of the optimal method is illustrated by simulation and experimental results with pan mechanism for cooking robot.

  18. Path-based Queries on Trajectory Data

    DEFF Research Database (Denmark)

    Krogh, Benjamin Bjerre; Pelekis, Nikos; Theodoridis, Yannis

    2014-01-01

    In traffic research, management, and planning a number of path-based analyses are heavily used, e.g., for computing turn-times, evaluating green waves, or studying traffic flow. These analyses require retrieving the trajectories that follow the full path being analyzed. Existing path queries cannot...... sufficiently support such path-based analyses because they retrieve all trajectories that touch any edge in the path. In this paper, we define and formalize the strict path query. This is a novel query type tailored to support path-based analysis, where trajectories must follow all edges in the path...... a specific path by only retrieving data from the first and last edge in the path. To correctly answer strict path queries existing network-constrained trajectory indexes must retrieve data from all edges in the path. An extensive performance study of NETTRA using a very large real-world trajectory data set...

  19. Tool path planning of hole-making operations in ejector plate of injection mould using modified shuffled frog leaping algorithm

    Directory of Open Access Journals (Sweden)

    Amol M. Dalavi

    2016-07-01

    Full Text Available Optimization of hole-making operations in manufacturing industry plays a vital role. Tool travel and tool switch planning are the two major issues in hole-making operations. Many industrial applications such as moulds, dies, engine block, automotive parts etc. requires machining of large number of holes. Large number of machining operations like drilling, enlargement or tapping/reaming are required to achieve the final size of individual hole, which gives rise to number of possible sequences to complete hole-making operations on the part depending upon the location of hole and tool sequence to be followed. It is necessary to find the optimal sequence of operations which minimizes the total processing cost of hole-making operations. In this work, therefore an attempt is made to reduce the total processing cost of hole-making operations by applying relatively new optimization algorithms known as shuffled frog leaping algorithm and proposed modified shuffled frog leaping algorithm for the determination of optimal sequence of hole-making operations. An industrial application example of ejector plate of injection mould is considered in this work to demonstrate the proposed approach. The obtained results by the shuffled frog leaping algorithm and proposed modified shuffled frog leaping algorithm are compared with each other. It is seen from the obtained results that the results of proposed modified shuffled frog leaping algorithm are superior to those obtained using shuffled frog leaping algorithm.

  20. Optimal Paths in Gliding Flight

    Science.gov (United States)

    Wolek, Artur

    Underwater gliders are robust and long endurance ocean sampling platforms that are increasingly being deployed in coastal regions. This new environment is characterized by shallow waters and significant currents that can challenge the mobility of these efficient (but traditionally slow moving) vehicles. This dissertation aims to improve the performance of shallow water underwater gliders through path planning. The path planning problem is formulated for a dynamic particle (or "kinematic car") model. The objective is to identify the path which satisfies specified boundary conditions and minimizes a particular cost. Several cost functions are considered. The problem is addressed using optimal control theory. The length scales of interest for path planning are within a few turn radii. First, an approach is developed for planning minimum-time paths, for a fixed speed glider, that are sub-optimal but are guaranteed to be feasible in the presence of unknown time-varying currents. Next the minimum-time problem for a glider with speed controls, that may vary between the stall speed and the maximum speed, is solved. Last, optimal paths that minimize change in depth (equivalently, maximize range) are investigated. Recognizing that path planning alone cannot overcome all of the challenges associated with significant currents and shallow waters, the design of a novel underwater glider with improved capabilities is explored. A glider with a pneumatic buoyancy engine (allowing large, rapid buoyancy changes) and a cylindrical moving mass mechanism (generating large pitch and roll moments) is designed, manufactured, and tested to demonstrate potential improvements in speed and maneuverability.

  1. Path Dependence

    DEFF Research Database (Denmark)

    Madsen, Mogens Ove

    Begrebet Path Dependence blev oprindelig udviklet inden for New Institutionel Economics af bl.a. David, Arthur og North. Begrebet har spredt sig vidt i samfundsvidenskaberne og undergået en udvikling. Dette paper propagerer for at der er sket så en så omfattende udvikling af begrebet, at man nu kan...... tale om 1. og 2. generation af Path Dependence begrebet. Den nyeste udvikling af begrebet har relevans for metodologi-diskusionerne i relation til Keynes...

  2. The development of radiation hardened tele-robot system - Development of path-planning and control technology for tele-operated redundant manipulator

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Pyung Hun; Park, Ki Cheol; Park, Suk Ho [Korea Advanced Institute of Science and Technology, Taejon (Korea)

    1999-04-01

    This project focuses on the development of the control system for a teleoperated redundant manipulator, which performs many tasks dexterously, while avoiding obstacles, instead of human workers in the extreme situations like nuclear power plants. To this end, four consecutive research works have been performed. First, two new methods for global path-planning have been developed to inspect the global behavior of the redundant manipulator. Second, characteristics of optimal solutions(COS) under inequality constraints have been analyzed and, using the COS, how to greatly enhance the conventional redundancy resolution methods in terms of performance and repeatability has also been proposed. Third, an effective control method for a redundant manipulator has been developed, which incorporates all kinds of physical limits into practical inequality constraints and is computationally efficient for real-time purposes. Finally, using this control method as the controller of the slave redundant manipulator and developing a master manipulator, the inertial torque and gravitation torque of which are negligible, a force-reflected teleoperation control system has been developed. Through the teleoperation control system, human operator can accurately control the position and the force of the end-effector of the slave manipulator while feeling the interaction force between the slave and the workpiece. In addition, the slave redundant manipulator autonomously can control the impedance and can optimize a given performance measure while avoiding physical limits such as joint angle limits and obstacles. 49 refs., 43 figs., 10 tabs. (Author)

  3. Implementation of a Multi-Robot Coverage Algorithm on a Two-Dimensional, Grid-Based Environment

    Science.gov (United States)

    2017-06-01

    different approaches is based on “ behavior -based” versus “system theory based” approaches to the problem. 1. Behavior –Based Approach Most behavior -based...otherwise, it performs the behavior of IG. This kind of algorithm could be classified as a system theory based approach since the change in the...systems, robot agents are likely to take over mine countermeasure (MCM) missions one day. The path planning coverage algorithm is an essential topic for

  4. Coverage-based constraints for IMRT optimization

    Science.gov (United States)

    Mescher, H.; Ulrich, S.; Bangert, M.

    2017-09-01

    Radiation therapy treatment planning requires an incorporation of uncertainties in order to guarantee an adequate irradiation of the tumor volumes. In current clinical practice, uncertainties are accounted for implicitly with an expansion of the target volume according to generic margin recipes. Alternatively, it is possible to account for uncertainties by explicit minimization of objectives that describe worst-case treatment scenarios, the expectation value of the treatment or the coverage probability of the target volumes during treatment planning. In this note we show that approaches relying on objectives to induce a specific coverage of the clinical target volumes are inevitably sensitive to variation of the relative weighting of the objectives. To address this issue, we introduce coverage-based constraints for intensity-modulated radiation therapy (IMRT) treatment planning. Our implementation follows the concept of coverage-optimized planning that considers explicit error scenarios to calculate and optimize patient-specific probabilities q(\\hat{d}, \\hat{v}) of covering a specific target volume fraction \\hat{v} with a certain dose \\hat{d} . Using a constraint-based reformulation of coverage-based objectives we eliminate the trade-off between coverage and competing objectives during treatment planning. In-depth convergence tests including 324 treatment plan optimizations demonstrate the reliability of coverage-based constraints for varying levels of probability, dose and volume. General clinical applicability of coverage-based constraints is demonstrated for two cases. A sensitivity analysis regarding penalty variations within this planing study based on IMRT treatment planning using (1) coverage-based constraints, (2) coverage-based objectives, (3) probabilistic optimization, (4) robust optimization and (5) conventional margins illustrates the potential benefit of coverage-based constraints that do not require tedious adjustment of target volume objectives.

  5. Path Creation

    DEFF Research Database (Denmark)

    Karnøe, Peter; Garud, Raghu

    2012-01-01

    This paper employs path creation as a lens to follow the emergence of the Danish wind turbine cluster. Supplier competencies, regulations, user preferences and a market for wind power did not pre-exist; all had to emerge in a tranformative manner involving multiple actors and artefacts. Competenc......This paper employs path creation as a lens to follow the emergence of the Danish wind turbine cluster. Supplier competencies, regulations, user preferences and a market for wind power did not pre-exist; all had to emerge in a tranformative manner involving multiple actors and artefacts....... Competencies emerged through processes and mechanisms such as co-creation that implicated multiple learning processes. The process was not an orderly linear one as emergent contingencies influenced the learning processes. An implication is that public policy to catalyse clusters cannot be based...

  6. Medicare Coverage Database

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Medicare Coverage Database (MCD) contains all National Coverage Determinations (NCDs) and Local Coverage Determinations (LCDs), local articles, and proposed NCD...

  7. A biologically inspired controller to solve the coverage problem in robotics.

    Science.gov (United States)

    Rañó, Iñaki; Santos, José A

    2017-06-05

    The coverage problem consists on computing a path or trajectory for a robot to pass over all the points in some free area and has applications ranging from floor cleaning to demining. Coverage is solved as a planning problem-providing theoretical validation of the solution-or through heuristic techniques which rely on experimental validation. Through a combination of theoretical results and simulations, this paper presents a novel solution to the coverage problem that exploits the chaotic behaviour of a simple biologically inspired motion controller, the Braitenberg vehicle 2b. Although chaos has been used for coverage, our approach has much less restrictive assumptions about the environment and can be implemented using on-board sensors. First, we prove theoretically that this vehicle-a well known model of animal tropotaxis-behaves as a charge in an electro-magnetic field. The motion equations can be reduced to a Hamiltonian system, and, therefore the vehicle follows quasi-periodic or chaotic trajectories, which pass arbitrarily close to any point in the work-space, i.e. it solves the coverage problem. Secondly, through a set of extensive simulations, we show that the trajectories cover regions of bounded workspaces, and full coverage is achieved when the perceptual range of the vehicle is short. We compare the performance of this new approach with different types of random motion controllers in the same bounded environments.

  8. Welding Robot Collision-Free Path Optimization

    Directory of Open Access Journals (Sweden)

    Xuewu Wang

    2017-02-01

    Full Text Available Reasonable welding path has a significant impact on welding efficiency, and a collision-free path should be considered first in the process of welding robot path planning. The shortest path length is considered as an optimization objective, and obstacle avoidance is considered as the constraint condition in this paper. First, a grid method is used as a modeling method after the optimization objective is analyzed. For local collision-free path planning, an ant colony algorithm is selected as the search strategy. Then, to overcome the shortcomings of the ant colony algorithm, a secondary optimization is presented to improve the optimization performance. Finally, the particle swarm optimization algorithm is used to realize global path planning. Simulation results show that the desired welding path can be obtained based on the optimization strategy.

  9. Using meta-analytic path analysis to test theoretical predictions in health behavior: An illustration based on meta-analyses of the theory of planned behavior

    OpenAIRE

    Hagger, Martin; Chan, Dervin K. C.; Protogerou, Cleo; Chatzisarantis, Nikos L. D.

    2016-01-01

    Objective Synthesizing research on social cognitive theories applied to health behavior is an important step in the development of an evidence base of psychological factors as targets for effective behavioral interventions. However, few meta-analyses of research on social cognitive theories in health contexts have conducted simultaneous tests of theoretically-stipulated pattern effects using path analysis. We argue that conducting path analyses of meta-analytic effects among constructs fr...

  10. MEASURING PATH DEPENDENCY

    Directory of Open Access Journals (Sweden)

    Peter Juhasz

    2017-03-01

    Full Text Available While risk management gained popularity during the last decades even some of the basic risk types are still far out of focus. One of these is path dependency that refers to the uncertainty of how we reach a certain level of total performance over time. While decision makers are careful in accessing how their position will look like the end of certain periods, little attention is given how they will get there through the period. The uncertainty of how a process will develop across a shorter period of time is often “eliminated” by simply choosing a longer planning time interval, what makes path dependency is one of the most often overlooked business risk types. After reviewing the origin of the problem we propose and compare seven risk measures to access path. Traditional risk measures like standard deviation of sub period cash flows fail to capture this risk type. We conclude that in most cases considering the distribution of the expected cash flow effect caused by the path dependency may offer the best method, but we may need to use several measures at the same time to include all the optimisation limits of the given firm

  11. Summary of DOD Acquisition Program Audit Coverage

    National Research Council Canada - National Science Library

    2001-01-01

    This report will provide the DoD audit community with information to support their planning efforts and provide management with information on the extent of audit coverage of DoD acquisition programs...

  12. Experiments towards model-based testing using Plan 9: Labelled transition file systems, stacking file systems, on-the-fly coverage measuring

    NARCIS (Netherlands)

    Belinfante, Axel; Guardiola, G.; Soriano, E.; Ballesteros, F.J.

    2006-01-01

    We report on experiments that we did on Plan 9/Inferno to gain more experience with the file-system-as-tool-interface approach. We reimplemented functionality that we earlier worked on in Unix, trying to use Plan 9 file system interfaces. The application domain for those experiments was model-based

  13. Spreading paths in partially observed social networks

    Science.gov (United States)

    Onnela, Jukka-Pekka; Christakis, Nicholas A.

    2012-03-01

    Understanding how and how far information, behaviors, or pathogens spread in social networks is an important problem, having implications for both predicting the size of epidemics, as well as for planning effective interventions. There are, however, two main challenges for inferring spreading paths in real-world networks. One is the practical difficulty of observing a dynamic process on a network, and the other is the typical constraint of only partially observing a network. Using static, structurally realistic social networks as platforms for simulations, we juxtapose three distinct paths: (1) the stochastic path taken by a simulated spreading process from source to target; (2) the topologically shortest path in the fully observed network, and hence the single most likely stochastic path, between the two nodes; and (3) the topologically shortest path in a partially observed network. In a sampled network, how closely does the partially observed shortest path (3) emulate the unobserved spreading path (1)? Although partial observation inflates the length of the shortest path, the stochastic nature of the spreading process also frequently derails the dynamic path from the shortest path. We find that the partially observed shortest path does not necessarily give an inflated estimate of the length of the process path; in fact, partial observation may, counterintuitively, make the path seem shorter than it actually is.

  14. Spreading paths in partially observed social networks.

    Science.gov (United States)

    Onnela, Jukka-Pekka; Christakis, Nicholas A

    2012-03-01

    Understanding how and how far information, behaviors, or pathogens spread in social networks is an important problem, having implications for both predicting the size of epidemics, as well as for planning effective interventions. There are, however, two main challenges for inferring spreading paths in real-world networks. One is the practical difficulty of observing a dynamic process on a network, and the other is the typical constraint of only partially observing a network. Using static, structurally realistic social networks as platforms for simulations, we juxtapose three distinct paths: (1) the stochastic path taken by a simulated spreading process from source to target; (2) the topologically shortest path in the fully observed network, and hence the single most likely stochastic path, between the two nodes; and (3) the topologically shortest path in a partially observed network. In a sampled network, how closely does the partially observed shortest path (3) emulate the unobserved spreading path (1)? Although partial observation inflates the length of the shortest path, the stochastic nature of the spreading process also frequently derails the dynamic path from the shortest path. We find that the partially observed shortest path does not necessarily give an inflated estimate of the length of the process path; in fact, partial observation may, counterintuitively, make the path seem shorter than it actually is.

  15. Providing Universal Health Insurance Coverage in Nigeria.

    Science.gov (United States)

    Okebukola, Peter O; Brieger, William R

    2016-07-07

    Despite a stated goal of achieving universal coverage, the National Health Insurance Scheme of Nigeria had achieved only 4% coverage 12 years after it was launched. This study assessed the plans of the National Health Insurance Scheme to achieve universal health insurance coverage in Nigeria by 2015 and discusses the challenges facing the scheme in achieving insurance coverage. In-depth interviews from various levels of the health-care system in the country, including providers, were conducted. The results of the analysis suggest that challenges to extending coverage include the difficulty in convincing autonomous state governments to buy into the scheme and an inadequate health workforce that might not be able to meet increased demand. Recommendations for increasing the scheme's coverage include increasing decentralization and strengthening human resources for health in the service delivery systems. Strong political will is needed as a catalyst to achieving these goals. © The Author(s) 2016.

  16. Path Planning for Unmanned Underwater Vehicle in 3D Space with Obstacles Using Spline-Imperialist Competitive Algorithm and Optimal Interval Type-2 Fuzzy Logic Controller

    Directory of Open Access Journals (Sweden)

    Ehsan Zakeri

    Full Text Available Abstract In this research, generation of a short and smooth path in three-dimensional space with obstacles for guiding an Unmanned Underwater Vehicle (UUV without collision is investigated. This is done by utilizing spline technique, in which the spline control points positions are determined by Imperialist Competitive Algorithm (ICA in three-dimensional space such that the shortest possible path from the starting point to the target point without colliding with obstacles is achieved. Furthermore, for guiding the UUV in the generated path, an Interval Type-2 Fuzzy Logic Controller (IT2FLC, the coefficients of which are optimized by considering an objective function that includes quadratic terms of the input forces and state error of the system, is used. Selecting such objective function reduces the control error and also the force applied to the UUV, which consequently leads to reduction of energy consumption. Therefore, by using a special method, desired signals of UUV state are obtained from generated three-dimensional optimal path such that tracking these signals by the controller leads to the tracking of this path by UUV. In this paper, the dynamical model of the UUV, entitled as "mUUV-WJ-1" , is derived and its hydrodynamic coefficients are calculated by CFD in order to be used in the simulations. For simulation by the method presented in this study, three environments with different obstacles are intended in order to check the performance of the IT2FLC controller in generating optimal paths for guiding the UUV. In this article, in addition to ICA, Particle Swarm Optimization (PSO and Artificial Bee Colony (ABC are also used for generation of the paths and the results are compared with each other. The results show the appropriate performance of ICA rather than ABC and PSO. Moreover, to evaluate the performance of the IT2FLC, optimal Type-1 Fuzzy Logic Controller (T1FLC and Proportional Integrator Differentiator (PID controller are designed

  17. Women's Health Insurance Coverage

    Science.gov (United States)

    ... Women's Health Policy Women’s Health Insurance Coverage Women’s Health Insurance Coverage Published: Oct 31, 2017 Facebook Twitter LinkedIn ... that many women continue to face. Sources of Health Insurance Coverage Employer-Sponsored Insurance: Approximately 57.9 million ...

  18. 42 CFR 457.410 - Health benefits coverage options.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Health benefits coverage options. 457.410 Section 457.410 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN... State Plan Requirements: Coverage and Benefits § 457.410 Health benefits coverage options. (a) Types of...

  19. Tool path in torus tool CNC machining

    Directory of Open Access Journals (Sweden)

    XU Ying

    2016-10-01

    Full Text Available This paper is about tool path in torus tool CNC machining.The mathematical model of torus tool is established.The tool path planning algorithm is determined through calculation of the cutter location,boundary discretization,calculation of adjacent tool path and so on,according to the conversion formula,the cutter contact point will be converted to the cutter location point and then these points fit a toolpath.Lastly,the path planning algorithm is implemented by using Matlab programming.The cutter location points for torus tool are calculated by Matlab,and then fit these points to a toolpath.While using UG software,another tool path of free surface is simulated of the same data.It is drew compared the two tool paths that using torus tool is more efficient.

  20. Background and rationale for the Society of Behavioral Medicine's position statement: expand United States health plan coverage for diabetes self-management education and support.

    Science.gov (United States)

    Sharp, Lisa K; Fisher, Edwin B; Gerber, Ben S

    2015-09-01

    The Society of Behavioral Medicine (SBM) recognizes that diabetes self-management (DSM) education and support are fundamental to teaching people how to manage their diabetes and decrease disease-related complications. Implementation of the Patient Protection and Affordable Care Act provides an opportunity to expand DSM education and support to many people who are currently excluded from such services due to lack of insurance coverage, current policy barriers, or simple failure of healthcare systems to provide them. Extending the range and provision of such services could translate into reduced diabetic complications, a reduction in unnecessary healthcare utilization, and significant health-related cost savings on a national level. SBM recommends that public and private insurers be required to reimburse for 12 h of DSM education and support annually for anyone with diabetes. Further, SBM recognizes that a range of modes and providers of DSM education and support have been shown effective, and that patient preferences and resources may influence choice. To address this, SBM urges health organizations to increase and diversify approaches toward DSM education and support they offer.

  1. Path Creation, Path Dependence and Breaking Away from the Path

    OpenAIRE

    Wang, Jens; Hedman, Jonas; Tuunainen, Virpi Kristiina

    2016-01-01

    The explanation of how and why firms succeed or fail is a recurrent research challenge. This is particularly important in the context of technological innovations. We focus on the role of historical events and decisions in explaining such success and failure. Using a case study of Nokia, we develop and extend a multi-layer path dependence framework. We identify four layers of path dependence: technical, strategic and leadership, organizational, and external collaboration. We show how path dep...

  2. 77 FR 16453 - Student Health Insurance Coverage

    Science.gov (United States)

    2012-03-21

    ... eliminating annual and lifetime dollar limits would result in dramatic premium hikes for student plans and.... Industry and university commenters noted that student health insurance coverage benefits typically... duplication of benefits and makes student plans more affordable. Industry commenters noted that student health...

  3. Finding the UV-Visible Path Forward: Proceedings of the Community Workshop to Plan the Future of UV/Visible Space Astrophysics

    OpenAIRE

    Scowen, Paul A.; Tripp, Todd; Beasley, Matt; Ardila, David; Andersson, B-G; Apellániz, Jesús Maíz; Barstow, Martin; Bianchi, Luciana; Calzetti, Daniela; Clampin, Mark; Evans, Christopher J.; France, Kevin; García, Miriam García; de Castro, Ana Gomez; Harris, Walt

    2016-01-01

    We present the science cases and technological discussions that came from the workshop titled ¿Finding the ultraviolet (UV)-Visible Path Forward¿ held at NASA GSFC 2015 June 25-26. The material presented outlines the compelling science that can be enabled by a next generation space-based observatory dedicated for UV¿visible science, the technologies that are available to include in that observatory design, and the range of possible alternative launch approaches that could also enable some of ...

  4. Formal language constrained path problems

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, C.; Jacob, R.; Marathe, M.

    1997-07-08

    In many path finding problems arising in practice, certain patterns of edge/vertex labels in the labeled graph being traversed are allowed/preferred, while others are disallowed. Motivated by such applications as intermodal transportation planning, the authors investigate the complexity of finding feasible paths in a labeled network, where the mode choice for each traveler is specified by a formal language. The main contributions of this paper include the following: (1) the authors show that the problem of finding a shortest path between a source and destination for a traveler whose mode choice is specified as a context free language is solvable efficiently in polynomial time, when the mode choice is specified as a regular language they provide algorithms with improved space and time bounds; (2) in contrast, they show that the problem of finding simple paths between a source and a given destination is NP-hard, even when restricted to very simple regular expressions and/or very simple graphs; (3) for the class of treewidth bounded graphs, they show that (i) the problem of finding a regular language constrained simple path between source and a destination is solvable in polynomial time and (ii) the extension to finding context free language constrained simple paths is NP-complete. Several extensions of these results are presented in the context of finding shortest paths with additional constraints. These results significantly extend the results in [MW95]. As a corollary of the results, they obtain a polynomial time algorithm for the BEST k-SIMILAR PATH problem studied in [SJB97]. The previous best algorithm was given by [SJB97] and takes exponential time in the worst case.

  5. [Medical coverage of a road bicycle race].

    Science.gov (United States)

    Reifferscheid, Florian; Stuhr, Markus; Harding, Ulf; Schüler, Christine; Thoms, Jürgen; Püschel, Klaus; Kappus, Stefan

    2010-07-01

    Major sport events require adequate expertise and experience concerning medical coverage and support. Medical and ambulance services need to cover both participants and spectators. Likewise, residents at the venue need to be provided for. Concepts have to include the possibility of major incidents related to the event. Using the example of the Hamburg Cyclassics, a road bicycle race and major event for professional and amateur cyclists, this article describes the medical coverage, number of patients, types of injuries and emergencies. Objectives regarding the planning of future events and essential medical coverage are consequently discussed. (c) Georg Thieme Verlag Stuttgart-New York.

  6. Family planning, antenatal and delivery care: cross-sectional survey evidence on levels of coverage and inequalities by public and private sector in 57 low- and middle-income countries.

    Science.gov (United States)

    Campbell, Oona M R; Benova, Lenka; MacLeod, David; Baggaley, Rebecca F; Rodrigues, Laura C; Hanson, Kara; Powell-Jackson, Timothy; Penn-Kekana, Loveday; Polonsky, Reen; Footman, Katharine; Vahanian, Alice; Pereira, Shreya K; Santos, Andreia Costa; Filippi, Veronique G A; Lynch, Caroline A; Goodman, Catherine

    2016-04-01

    The objective of this study was to assess the role of the private sector in low- and middle-income countries (LMICs). We used Demographic and Health Surveys for 57 countries (2000-2013) to evaluate the private sector's share in providing three reproductive and maternal/newborn health services (family planning, antenatal and delivery care), in total and by socio-economic position. We used data from 865 547 women aged 15-49, representing a total of 3 billion people. We defined 'met and unmet need for services' and 'use of appropriate service types' clearly and developed explicit classifications of source and sector of provision. Across the four regions (sub-Saharan Africa, Middle East/Europe, Asia and Latin America), unmet need ranged from 28% to 61% for family planning, 8% to 22% for ANC and 21% to 51% for delivery care. The private-sector share among users of family planning services was 37-39% across regions (overall mean: 37%; median across countries: 41%). The private-sector market share among users of ANC was 13-61% across regions (overall mean: 44%; median across countries: 15%). The private-sector share among appropriate deliveries was 9-56% across regions (overall mean: 40%; median across countries: 14%). For all three healthcare services, women in the richest wealth quintile used private services more than the poorest. Wealth gaps in met need for services were smallest for family planning and largest for delivery care. The private sector serves substantial numbers of women in LMICs, particularly the richest. To achieve universal health coverage, including adequate quality care, it is imperative to understand this sector, starting with improved data collection on healthcare provision. © 2016 The Authors. Tropical Medicine & International Health published by John Wiley & Sons Ltd.

  7. Feynman's path integrals and Bohm's particle paths

    International Nuclear Information System (INIS)

    Tumulka, Roderich

    2005-01-01

    Both Bohmian mechanics, a version of quantum mechanics with trajectories, and Feynman's path integral formalism have something to do with particle paths in space and time. The question thus arises how the two ideas relate to each other. In short, the answer is, path integrals provide a re-formulation of Schroedinger's equation, which is half of the defining equations of Bohmian mechanics. I try to give a clear and concise description of the various aspects of the situation. (letters and comments)

  8. Path coupling and aggregate path coupling

    CERN Document Server

    Kovchegov, Yevgeniy

    2018-01-01

    This book describes and characterizes an extension to the classical path coupling method applied to statistical mechanical models, referred to as aggregate path coupling. In conjunction with large deviations estimates, the aggregate path coupling method is used to prove rapid mixing of Glauber dynamics for a large class of statistical mechanical models, including models that exhibit discontinuous phase transitions which have traditionally been more difficult to analyze rigorously. The book shows how the parameter regions for rapid mixing for several classes of statistical mechanical models are derived using the aggregate path coupling method.

  9. SU-E-T-266: Proton PBS Plan Design and Robustness Evaluation for Head and Neck Cancers

    International Nuclear Information System (INIS)

    Liang, X; Tang, S; Zhai, H; Kirk, M; Kalbasi, A; Lin, A; Ahn, P; Tochner, Z; McDonough, J; Both, S

    2014-01-01

    Purpose: To describe a newly designed proton pencil beam scanning (PBS) planning technique for radiotherapy of patients with bilateral oropharyngeal cancer, and to assess plan robustness. Methods: We treated 10 patients with proton PBS plans using 2 posterior oblique field (2F PBS) comprised of 80% single-field uniform dose (SFUD) and 20% intensity-modulated proton therapy (IMPT). All patients underwent weekly CT scans for verification. Using dosimetric indicators for both targets and organs at risk (OARs), we quantitatively compared initial plans and verification plans using student t-tests. We created a second proton PBS plan for each patient using 2 posterior oblique plus 1 anterior field comprised of 100% SFUD (3F PBS). We assessed plan robustness for both proton plan groups, as well as a photon volumetric modulated arc therapy (VMAT) plan group by comparing initial and verification plans. Results: The 2F PBS plans were not robust in target coverage. D98% for clinical target volume (CTV) degraded from 100% to 96% on average, with maximum change Δ D98% of −24%. Two patients were moved to photon VMAT treatment due to insufficient CTV coverage on verification plans. Plan robustness was especially weak in the low-anterior neck. The 3F PBS plans, however, demonstrated robust target coverage, which was comparable to the VMAT photon plan group. Doses to oral cavity were lower in the Proton PBS plans compared to photon VMAT plans due to no lower exit dose to the oral cavity. Conclusion: Proton PBS plans using 2 posterior oblique fields were not robust for CTV coverage, due to variable positioning of redundant soft tissue in the posterior neck. We designed 3-field proton PBS plans using an anterior field to avoid long heterogeneous paths in the low neck. These 3-field proton PBS plans had significantly improved plan robustness, and the robustness is comparable to VMAT photon plans

  10. State contraceptive coverage laws: creative responses to questions of "conscience".

    Science.gov (United States)

    Dailard, C

    1999-08-01

    The Federal Employees Health Benefits Program (FEHBP) guaranteed contraceptive coverage for employees of the federal government. However, opponents of the FEHBP contraceptive coverage questioned the viability of the conscience clause. Supporters of the contraceptive coverage pressed for the narrowest exemption, one that only permit religious plans that clearly states religious objection to contraception. There are six of the nine states that have enacted contraceptive coverage laws aimed at the private sector. The statutes included a provision of conscience clause. The private sector disagrees to the plan since almost all of the employees¿ work for employers who only offer one plan. The scope of exemption for employers was an issue in five states that have enacted the contraceptive coverage. In Hawaii and California, it was exemplified that if employers are exempted from the contraceptive coverage based on religious grounds, an employee will be entitled to purchase coverage directly from the plan. There are still questions on how an insurer, who objects based on religious grounds to a plan with contraceptive coverage, can function in a marketplace where such coverage is provided by most private sector employers.

  11. Medicaid and Children's Health Insurance Programs; Mental Health Parity and Addiction Equity Act of 2008; the Application of Mental Health Parity Requirements to Coverage Offered by Medicaid Managed Care Organizations, the Children's Health Insurance Program (CHIP), and Alternative Benefit Plans. Final rule.

    Science.gov (United States)

    2016-03-30

    This final rule will address the application of certain requirements set forth in the Public Health Service Act, as amended by the Paul Wellstone and Pete Domenici Mental Health Parity and Addiction Equity Act of 2008, to coverage offered by Medicaid managed care organizations, Medicaid Alternative Benefit Plans, and Children’s Health Insurance Programs.

  12. The Historical Path of Evaluation as Reflected in the Content of Evaluation and Program Planning

    DEFF Research Database (Denmark)

    Ayob, Abu H.; Morell, Jonathan A.

    2016-01-01

    This paper examines the intellectual structure of evaluation by means of citation analysis. By using various article attributes and citation counts in Google Scholar and (Social) Science Citation Index Web of Science, we analyze all articles published in Evaluation and Program Planning from 2000...... until 2012. We identify and discuss the characteristics and development of the field as reflected in the history of those citations....

  13. Generating Approximative Minimum Length Paths in 3D for UAVs

    DEFF Research Database (Denmark)

    Schøler, Flemming; la Cour-Harbo, Anders; Bisgaard, Morten

    2012-01-01

    We consider the challenge of planning a minimum length path from an initial position to a desired position for a rotorcraft. The path is found in a 3-dimensional Euclidean space containing a geometric obstacle. We base our approach on visibility graphs which have been used extensively for path pl...

  14. A focussed dynamic path finding algorithm with constraints

    CSIR Research Space (South Africa)

    Leenen, L

    2013-11-01

    Full Text Available heuristic to focus the search for an optimal path. Existing approaches to solving path planning problems tend to combine path costs with various other criteria such as obstacle avoidance in the objective function which is being optimised. The authors...

  15. Did the Affordable Care Act's Dependent Coverage Mandate Increase Premiums?

    OpenAIRE

    Briggs Depew; James Bailey

    2014-01-01

    We investigate the impact of the Affordable Care Act's dependent coverage mandate on insurance premiums. The expansion of dependent coverage under the ACA allows young adults to remain on their parent's private health insurance plans until the age of 26. We find that the mandate has led to a 2.5-2.8 percent increase in premiums for health insurance plans that cover children, relative to single-coverage plans. We find no evidence that the mandate caused an increase in the amount of the employe...

  16. A Cooperative Search and Coverage Algorithm with Controllable Revisit and Connectivity Maintenance for Multiple Unmanned Aerial Vehicles

    Directory of Open Access Journals (Sweden)

    Zhong Liu

    2018-05-01

    Full Text Available In this paper, we mainly study a cooperative search and coverage algorithm for a given bounded rectangle region, which contains several unknown stationary targets, by a team of unmanned aerial vehicles (UAVs with non-ideal sensors and limited communication ranges. Our goal is to minimize the search time, while gathering more information about the environment and finding more targets. For this purpose, a novel cooperative search and coverage algorithm with controllable revisit mechanism is presented. Firstly, as the representation of the environment, the cognitive maps that included the target probability map (TPM, the uncertain map (UM, and the digital pheromone map (DPM are constituted. We also design a distributed update and fusion scheme for the cognitive map. This update and fusion scheme can guarantee that each one of the cognitive maps converges to the same one, which reflects the targets’ true existence or absence in each cell of the search region. Secondly, we develop a controllable revisit mechanism based on the DPM. This mechanism can concentrate the UAVs to revisit sub-areas that have a large target probability or high uncertainty. Thirdly, in the frame of distributed receding horizon optimizing, a path planning algorithm for the multi-UAVs cooperative search and coverage is designed. In the path planning algorithm, the movement of the UAVs is restricted by the potential fields to meet the requirements of avoiding collision and maintaining connectivity constraints. Moreover, using the minimum spanning tree (MST topology optimization strategy, we can obtain a tradeoff between the search coverage enhancement and the connectivity maintenance. The feasibility of the proposed algorithm is demonstrated by comparison simulations by way of analyzing the effects of the controllable revisit mechanism and the connectivity maintenance scheme. The Monte Carlo method is employed to validate the influence of the number of UAVs, the sensing radius

  17. On the Meta Distribution of Coverage Probability in Uplink Cellular Networks

    KAUST Repository

    Elsawy, Hesham; Alouini, Mohamed-Slim

    2017-01-01

    This letter studies the meta distribution of coverage probability (CP), within a stochastic geometry framework, for cellular uplink transmission with fractional path-loss inversion power control. Using the widely accepted Poisson point process (PPP

  18. Multiagent path-finding in strategic games

    OpenAIRE

    Mihevc, Simon

    2014-01-01

    In this thesis I worked on creating, comparing and improving algorithms for multi-agent path planning on a domain typical for real-time strategy games. I implemented and compared Multiagent pathfinding using clearance and Multiagent pathfinding using independence detection and operator decomposition. I discovered that they had problems maintaining group compactness and took too long to calculate the path. I considerably improved the efficiency of both algorithms.

  19. Contraception coverage and methods used among women in South ...

    African Journals Online (AJOL)

    Background. Globally, family planning services are being strengthened and the range of contraceptive choices expanded. Data on contraceptive coverage and service gaps could help to shape these initiatives. Objective. To assess contraception coverage in South Africa (SA) and identify underserved populations and ...

  20. Path-dependent functions

    International Nuclear Information System (INIS)

    Khrapko, R.I.

    1985-01-01

    A uniform description of various path-dependent functions is presented with the help of expansion of the type of the Taylor series. So called ''path-integrals'' and ''path-tensor'' are introduced which are systems of many-component quantities whose values are defined for arbitrary paths in coordinated region of space in such a way that they contain a complete information on the path. These constructions are considered as elementary path-dependent functions and are used instead of power monomials in the usual Taylor series. Coefficients of such an expansion are interpreted as partial derivatives dependent on the order of the differentiations or else as nonstandard cavariant derivatives called two-point derivatives. Some examples of pathdependent functions are presented.Space curvature tensor is considered whose geometrica properties are determined by the (non-transitive) translator of parallel transport of a general type. Covariant operation leading to the ''extension'' of tensor fiels is pointed out

  1. Iterated Leavitt Path Algebras

    International Nuclear Information System (INIS)

    Hazrat, R.

    2009-11-01

    Leavitt path algebras associate to directed graphs a Z-graded algebra and in their simplest form recover the Leavitt algebras L(1,k). In this note, we introduce iterated Leavitt path algebras associated to directed weighted graphs which have natural ± Z grading and in their simplest form recover the Leavitt algebras L(n,k). We also characterize Leavitt path algebras which are strongly graded. (author)

  2. Pulled Motzkin paths

    Energy Technology Data Exchange (ETDEWEB)

    Janse van Rensburg, E J, E-mail: rensburg@yorku.c [Department of Mathematics and Statistics, York University, Toronto, ON, M3J 1P3 (Canada)

    2010-08-20

    In this paper the models of pulled Dyck paths in Janse van Rensburg (2010 J. Phys. A: Math. Theor. 43 215001) are generalized to pulled Motzkin path models. The generating functions of pulled Motzkin paths are determined in terms of series over trinomial coefficients and the elastic response of a Motzkin path pulled at its endpoint (see Orlandini and Whittington (2004 J. Phys. A: Math. Gen. 37 5305-14)) is shown to be R(f) = 0 for forces pushing the endpoint toward the adsorbing line and R(f) = f(1 + 2cosh f))/(2sinh f) {yields} f as f {yields} {infinity}, for forces pulling the path away from the X-axis. In addition, the elastic response of a Motzkin path pulled at its midpoint is shown to be R(f) = 0 for forces pushing the midpoint toward the adsorbing line and R(f) = f(1 + 2cosh (f/2))/sinh (f/2) {yields} 2f as f {yields} {infinity}, for forces pulling the path away from the X-axis. Formal combinatorial identities arising from pulled Motzkin path models are also presented. These identities are the generalization of combinatorial identities obtained in directed paths models to their natural trinomial counterparts.

  3. Pulled Motzkin paths

    Science.gov (United States)

    Janse van Rensburg, E. J.

    2010-08-01

    In this paper the models of pulled Dyck paths in Janse van Rensburg (2010 J. Phys. A: Math. Theor. 43 215001) are generalized to pulled Motzkin path models. The generating functions of pulled Motzkin paths are determined in terms of series over trinomial coefficients and the elastic response of a Motzkin path pulled at its endpoint (see Orlandini and Whittington (2004 J. Phys. A: Math. Gen. 37 5305-14)) is shown to be R(f) = 0 for forces pushing the endpoint toward the adsorbing line and R(f) = f(1 + 2cosh f))/(2sinh f) → f as f → ∞, for forces pulling the path away from the X-axis. In addition, the elastic response of a Motzkin path pulled at its midpoint is shown to be R(f) = 0 for forces pushing the midpoint toward the adsorbing line and R(f) = f(1 + 2cosh (f/2))/sinh (f/2) → 2f as f → ∞, for forces pulling the path away from the X-axis. Formal combinatorial identities arising from pulled Motzkin path models are also presented. These identities are the generalization of combinatorial identities obtained in directed paths models to their natural trinomial counterparts.

  4. Pulled Motzkin paths

    International Nuclear Information System (INIS)

    Janse van Rensburg, E J

    2010-01-01

    In this paper the models of pulled Dyck paths in Janse van Rensburg (2010 J. Phys. A: Math. Theor. 43 215001) are generalized to pulled Motzkin path models. The generating functions of pulled Motzkin paths are determined in terms of series over trinomial coefficients and the elastic response of a Motzkin path pulled at its endpoint (see Orlandini and Whittington (2004 J. Phys. A: Math. Gen. 37 5305-14)) is shown to be R(f) = 0 for forces pushing the endpoint toward the adsorbing line and R(f) = f(1 + 2cosh f))/(2sinh f) → f as f → ∞, for forces pulling the path away from the X-axis. In addition, the elastic response of a Motzkin path pulled at its midpoint is shown to be R(f) = 0 for forces pushing the midpoint toward the adsorbing line and R(f) = f(1 + 2cosh (f/2))/sinh (f/2) → 2f as f → ∞, for forces pulling the path away from the X-axis. Formal combinatorial identities arising from pulled Motzkin path models are also presented. These identities are the generalization of combinatorial identities obtained in directed paths models to their natural trinomial counterparts.

  5. Sideline coverage of youth football.

    Science.gov (United States)

    Rizzone, Katie; Diamond, Alex; Gregory, Andrew

    2013-01-01

    Youth football is a popular sport in the United States and has been for some time. There are currently more than 3 million participants in youth football leagues according to USA Football. While the number of participants and overall injuries may be higher in other sports, football has a higher rate of injuries. Most youth sporting events do not have medical personnel on the sidelines in event of an injury or emergency. Therefore it is necessary for youth sports coaches to undergo basic medical training in order to effectively act in these situations. In addition, an argument could be made that appropriate medical personnel should be on the sideline for collision sports at all levels, from youth to professional. This article will discuss issues pertinent to sideline coverage of youth football, including coaching education, sideline personnel, emergency action plans, age and size divisions, tackle versus flag football, and injury prevention.

  6. Multi-Dimensional Path Queries

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    1998-01-01

    to create nested path structures. We present an SQL-like query language that is based on path expressions and we show how to use it to express multi-dimensional path queries that are suited for advanced data analysis in decision support environments like data warehousing environments......We present the path-relationship model that supports multi-dimensional data modeling and querying. A path-relationship database is composed of sets of paths and sets of relationships. A path is a sequence of related elements (atoms, paths, and sets of paths). A relationship is a binary path...

  7. Resolution, coverage, and geometry beyond traditional limits

    Energy Technology Data Exchange (ETDEWEB)

    Ronen, Shuki; Ferber, Ralf

    1998-12-31

    The presentation relates to the optimization of the image of seismic data and improved resolution and coverage of acquired data. Non traditional processing methods such as inversion to zero offset (IZO) are used. To realize the potential of saving acquisition cost by reducing in-fill and to plan resolution improvement by processing, geometry QC methods such as DMO Dip Coverage Spectrum (DDCS) and Bull`s Eyes Analysis are used. The DDCS is a 2-D spectrum whose entries consist of the DMO (Dip Move Out) coverage for a particular reflector specified by it`s true time dip and reflector normal strike. The Bull`s Eyes Analysis relies on real time processing of synthetic data generated with the real geometry. 4 refs., 6 figs.

  8. Unique Path Partitions

    DEFF Research Database (Denmark)

    Bessenrodt, Christine; Olsson, Jørn Børling; Sellers, James A.

    2013-01-01

    We give a complete classification of the unique path partitions and study congruence properties of the function which enumerates such partitions.......We give a complete classification of the unique path partitions and study congruence properties of the function which enumerates such partitions....

  9. Hamiltonian path integrals

    International Nuclear Information System (INIS)

    Prokhorov, L.V.

    1982-01-01

    The properties of path integrals associated with the allowance for nonstandard terms reflecting the operator nature of the canonical variables are considered. Rules for treating such terms (''equivalence rules'') are formulated. Problems with a boundary, the behavior of path integrals under canonical transformations, and the problem of quantization of dynamical systems with constraints are considered in the framework of the method

  10. Proton Therapy Coverage for Prostate Cancer Treatment

    International Nuclear Information System (INIS)

    Vargas, Carlos; Wagner, Marcus; Mahajan, Chaitali; Indelicato, Daniel; Fryer, Amber; Falchook, Aaron; Horne, David C.; Chellini, Angela; McKenzie, Craig C.; Lawlor, Paula C.; Li Zuofeng; Lin Liyong; Keole, Sameer

    2008-01-01

    Purpose: To determine the impact of prostate motion on dose coverage in proton therapy. Methods and Materials: A total of 120 prostate positions were analyzed on 10 treatment plans for 10 prostate patients treated using our low-risk proton therapy prostate protocol (University of Florida Proton Therapy Institute 001). Computed tomography and magnetic resonance imaging T 2 -weighted turbo spin-echo scans were registered for all cases. The planning target volume included the prostate with a 5-mm axial and 8-mm superoinferior expansion. The prostate was repositioned using 5- and 10-mm one-dimensional vectors and 10-mm multidimensional vectors (Points A-D). The beam was realigned for the 5- and 10-mm displacements. The prescription dose was 78 Gy equivalent (GE). Results: The mean percentage of rectum receiving 70 Gy (V 70 ) was 7.9%, the bladder V 70 was 14.0%, and the femoral head/neck V 50 was 0.1%, and the mean pelvic dose was 4.6 GE. The percentage of prostate receiving 78 Gy (V 78 ) with the 5-mm movements changed by -0.2% (range, 0.006-0.5%, p > 0.7). However, the prostate V 78 after a 10-mm displacement changed significantly (p 78 coverage had a large and significant reduction of 17.4% (range, 13.5-17.4%, p 78 coverage of the clinical target volume. The minimal prostate dose was reduced 33% (25.8 GE), on average, for Points A-D. The prostate minimal dose improved from 69.3 GE to 78.2 GE (p < 0.001) with realignment for 10-mm movements. Conclusion: The good dose coverage and low normal doses achieved for the initial plan was maintained with movements of ≤5 mm. Beam realignment improved coverage for 10-mm displacements

  11. Path planning during combustion mode switch

    Science.gov (United States)

    Jiang, Li; Ravi, Nikhil

    2015-12-29

    Systems and methods are provided for transitioning between a first combustion mode and a second combustion mode in an internal combustion engine. A current operating point of the engine is identified and a target operating point for the internal combustion engine in the second combustion mode is also determined. A predefined optimized transition operating point is selected from memory. While operating in the first combustion mode, one or more engine actuator settings are adjusted to cause the operating point of the internal combustion engine to approach the selected optimized transition operating point. When the engine is operating at the selected optimized transition operating point, the combustion mode is switched from the first combustion mode to the second combustion mode. While operating in the second combustion mode, one or more engine actuator settings are adjusted to cause the operating point of the internal combustion to approach the target operating point.

  12. Wind Corrections in Flight Path Planning

    Directory of Open Access Journals (Sweden)

    Martin Selecký

    2013-05-01

    Full Text Available Abstract When operating autonomous unmanned aerial vehicles (UAVs in real environments it is necessary to deal with the effects of wind that causes the aircraft to drift in a certain direction. In such conditions it is hard or even impossible for UAVs with a bounded turning rate to follow certain trajectories. We designed a method based on an Accelerated A* algorithm that allows the trajectory planner to take the wind effects into account and to generate states that are reachable by UAV. This method was tested on hardware UAV and the reachability of its generated trajectories was compared to the trajectories computed by the original Accelerated A*.

  13. USV Path Planning Using Potential Field Model

    Science.gov (United States)

    2017-09-01

    on the Clearpath USV is identified. A bollard pull test was performed in the CAVR test tank to evaluate this relationship. The USV was given thrust...commands from -1.0 (reverse) to 1.0 (forward) while statically attached to the side of the CAVR test tank with a load cell in line with mooring. The...and illustrates the lack of reverse thrust of the USV. The forward thrust direction is much more effective and increases until settling out at 40.0 N

  14. Towards Informative Path Planning for Acoustic SLAM

    OpenAIRE

    Evers, C; Moore, A; Naylor, P

    2016-01-01

    Acoustic scene mapping is a challenging task as microphone arrays can often localize sound sources only in terms of their directions. Spatial diversity can be exploited constructively to infer source-sensor range when using microphone arrays installed on moving platforms, such as robots. As the absolute location of a moving robot is often unknown in practice, Acoustic Simultaneous Localization And Mapping (a-SLAM) is required in order to localize the moving robot?s positions and jointly map t...

  15. Path integration quantization

    International Nuclear Information System (INIS)

    DeWitt-Morette, C.

    1983-01-01

    Much is expected of path integration as a quantization procedure. Much more is possible if one recognizes that path integration is at the crossroad of stochastic and differential calculus and uses the full power of both stochastic and differential calculus in setting up and computing path integrals. In contrast to differential calculus, stochastic calculus has only comparatively recently become an instrument of thought. It has nevertheless already been used in a variety of challenging problems, for instance in the quantization problem. The author presents some applications of the stochastic scheme. (Auth.)

  16. Two dimensional simplicial paths

    International Nuclear Information System (INIS)

    Piso, M.I.

    1994-07-01

    Paths on the R 3 real Euclidean manifold are defined as 2-dimensional simplicial strips which are orbits of the action of a discrete one-parameter group. It is proven that there exists at least one embedding of R 3 in the free Z-module generated by S 2 (x 0 ). The speed is defined as the simplicial derivative of the path. If mass is attached to the simplex, the free Lagrangian is proportional to the width of the path. In the continuum limit, the relativistic form of the Lagrangian is recovered. (author). 7 refs

  17. Zero-Slack, Noncritical Paths

    Science.gov (United States)

    Simons, Jacob V., Jr.

    2017-01-01

    The critical path method/program evaluation and review technique method of project scheduling is based on the importance of managing a project's critical path(s). Although a critical path is the longest path through a network, its location in large projects is facilitated by the computation of activity slack. However, logical fallacies in…

  18. Acquisition Path Analysis as a Collaborative Activity

    International Nuclear Information System (INIS)

    Nakao, A.; Grundule, R.; Gushchyn, K.; El Gebaly, A.; Higgy, R.; Tsvetkov, I.; Mandl, W.

    2015-01-01

    In the International Atomic Energy Agency, acquisition path analysis (APA) is indispensable to safeguards implementation. It is an integral part of both State evaluation process and the development of State level safeguards approaches, all performed through ongoing collaborative analysis of all available safeguards relevant information by State evaluation groups (SEG) with participation of other contributors, as required. To perform comprehensive State evaluation, to develop and revise State-level safeguards approaches, and to prepare annual implementation plans, the SEG in its collaborative analysis follows accepted safeguards methodology and guidance. In particular, the guide ''Performing Acquisition Path Analysis for the Development of a State-level Safeguards Approach for a State with a CSA'' is used. This guide identifies four major steps of the APA process: 1. Consolidating information about the State's past, present and planned nuclear fuel cycle-related capabilities and infrastructure; 2. Identifying and visually presenting technically plausible acquisition paths for the State; 3. Assessing acquisition path steps (State's technical capabilities and possible actions) along the identified acquisition paths; and 4. Assessing the time needed to accomplish each identified technically plausible acquisition path for the State. The paper reports on SEG members' and other contributors' experience with APA when following the above steps, including the identification of plausible acquisition pathways, estimation of time frames for all identified steps and determination of the time needed to accomplish each acquisition path. The difficulties that the SEG encountered during the process of performing the APA are also addressed. Feedback in the form of practical suggestions for improving the clarity of the acquisition path step assessment forms and a proposal for software support are also included. (author)

  19. Coverage Metrics for Model Checking

    Science.gov (United States)

    Penix, John; Visser, Willem; Norvig, Peter (Technical Monitor)

    2001-01-01

    When using model checking to verify programs in practice, it is not usually possible to achieve complete coverage of the system. In this position paper we describe ongoing research within the Automated Software Engineering group at NASA Ames on the use of test coverage metrics to measure partial coverage and provide heuristic guidance for program model checking. We are specifically interested in applying and developing coverage metrics for concurrent programs that might be used to support certification of next generation avionics software.

  20. Groebner Finite Path Algebras

    OpenAIRE

    Leamer, Micah J.

    2004-01-01

    Let K be a field and Q a finite directed multi-graph. In this paper I classify all path algebras KQ and admissible orders with the property that all of their finitely generated ideals have finite Groebner bases. MS

  1. Quivers of Bound Path Algebras and Bound Path Coalgebras

    Directory of Open Access Journals (Sweden)

    Dr. Intan Muchtadi

    2010-09-01

    Full Text Available bras and coalgebras can be represented as quiver (directed graph, and from quiver we can construct algebras and coalgebras called path algebras and path coalgebras. In this paper we show that the quiver of a bound path coalgebra (resp. algebra is the dual quiver of its bound path algebra (resp. coalgebra.

  2. Paths correlation matrix.

    Science.gov (United States)

    Qian, Weixian; Zhou, Xiaojun; Lu, Yingcheng; Xu, Jiang

    2015-09-15

    Both the Jones and Mueller matrices encounter difficulties when physically modeling mixed materials or rough surfaces due to the complexity of light-matter interactions. To address these issues, we derived a matrix called the paths correlation matrix (PCM), which is a probabilistic mixture of Jones matrices of every light propagation path. Because PCM is related to actual light propagation paths, it is well suited for physical modeling. Experiments were performed, and the reflection PCM of a mixture of polypropylene and graphite was measured. The PCM of the mixed sample was accurately decomposed into pure polypropylene's single reflection, pure graphite's single reflection, and depolarization caused by multiple reflections, which is consistent with the theoretical derivation. Reflection parameters of rough surface can be calculated from PCM decomposition, and the results fit well with the theoretical calculations provided by the Fresnel equations. These theoretical and experimental analyses verify that PCM is an efficient way to physically model light-matter interactions.

  3. Leavitt path algebras

    CERN Document Server

    Abrams, Gene; Siles Molina, Mercedes

    2017-01-01

    This book offers a comprehensive introduction by three of the leading experts in the field, collecting fundamental results and open problems in a single volume. Since Leavitt path algebras were first defined in 2005, interest in these algebras has grown substantially, with ring theorists as well as researchers working in graph C*-algebras, group theory and symbolic dynamics attracted to the topic. Providing a historical perspective on the subject, the authors review existing arguments, establish new results, and outline the major themes and ring-theoretic concepts, such as the ideal structure, Z-grading and the close link between Leavitt path algebras and graph C*-algebras. The book also presents key lines of current research, including the Algebraic Kirchberg Phillips Question, various additional classification questions, and connections to noncommutative algebraic geometry. Leavitt Path Algebras will appeal to graduate students and researchers working in the field and related areas, such as C*-algebras and...

  4. Flight Path Recovery System (FPRS) design study

    Energy Technology Data Exchange (ETDEWEB)

    1978-09-01

    The study contained herein presents a design for a Flight Path Recovery System (FPPS) for use in the NURE Program which will be more accurate than systems presently used, provide position location data in digital form suitable for automatic data processing, and provide for flight path recovery in a more economic and operationally suitable manner. The design is based upon the use of presently available hardware and technoloy, and presents little, it any, development risk. In addition, a Flight Test Plan designed to test the FPRS design concept is presented.

  5. Flight Path Recovery System (FPRS) design study

    International Nuclear Information System (INIS)

    1978-09-01

    The study contained herein presents a design for a Flight Path Recovery System (FPPS) for use in the NURE Program which will be more accurate than systems presently used, provide position location data in digital form suitable for automatic data processing, and provide for flight path recovery in a more economic and operationally suitable manner. The design is based upon the use of presently available hardware and technoloy, and presents little, it any, development risk. In addition, a Flight Test Plan designed to test the FPRS design concept is presented

  6. Health Insurance Coverage: Early Release of Estimates from the National Health Interview Survey, January -- June 2013

    Science.gov (United States)

    ... from 2010 to 2013 were also evaluated using logistic regression analysis. State-specific health insurance estimates are ... coverage options; compare health insurance plans based on cost, benefits, and other important features; choose a plan; ...

  7. The Thinnest Path Problem

    Science.gov (United States)

    2016-07-22

    be reduced to TP in -D UDH for any . We then show that the 2-D disk hypergraph constructed in the proof of Theorem 1 can be modified to an exposed...transmission range that induces hy- peredge , i.e., (3) GAO et al.: THINNEST PATH PROBLEM 1181 Theorem 5 shows that the covered area of the path...representation of (the two hyperedges rooted at from the example given in Fig. 6 are illustrated in green and blue, respectively). step, we show in this

  8. Path dependence and creation

    DEFF Research Database (Denmark)

    Garud, Raghu; Karnøe, Peter

    This edited volume stems from a conference held in Copenhagen that the authors ran in August of 1997. The authors, aware of the recent work in evolutionary theory and the science of chaos and complexity, challenge the sometimes deterministic flavour of this work. They are interested in uncovering...... the place of agency in these theories that take history so seriously. In the end, they are as interested in path creation and destruction as they are in path dependence. This book is compiled of both theoretical and empirical writing. It shows relatively well-known industries such as the automobile...

  9. Reparametrization in the path integral

    International Nuclear Information System (INIS)

    Storchak, S.N.

    1983-01-01

    The question of the invariance of a measure in the n-dimensional path integral under the path reparametrization is considered. The non-invariance of the measure through the jacobian is suggeste. After the path integral reparametrization the representatioq for the Green's function of the Hamilton operator in terms of the path integral with the classical Hamiltonian has been obtained

  10. Recommendation system for immunization coverage and monitoring.

    Science.gov (United States)

    Bhatti, Uzair Aslam; Huang, Mengxing; Wang, Hao; Zhang, Yu; Mehmood, Anum; Di, Wu

    2018-01-02

    Immunization averts an expected 2 to 3 million deaths every year from diphtheria, tetanus, pertussis (whooping cough), and measles; however, an additional 1.5 million deaths could be avoided if vaccination coverage was improved worldwide. 1 1 Data source for immunization records of 1.5 M: http://www.who.int/mediacentre/factsheets/fs378/en/ New vaccination technologies provide earlier diagnoses, personalized treatments and a wide range of other benefits for both patients and health care professionals. Childhood diseases that were commonplace less than a generation ago have become rare because of vaccines. However, 100% vaccination coverage is still the target to avoid further mortality. Governments have launched special campaigns to create an awareness of vaccination. In this paper, we have focused on data mining algorithms for big data using a collaborative approach for vaccination datasets to resolve problems with planning vaccinations in children, stocking vaccines, and tracking and monitoring non-vaccinated children appropriately. Geographical mapping of vaccination records helps to tackle red zone areas, where vaccination rates are poor, while green zone areas, where vaccination rates are good, can be monitored to enable health care staff to plan the administration of vaccines. Our recommendation algorithm assists in these processes by using deep data mining and by accessing records of other hospitals to highlight locations with lower rates of vaccination. The overall performance of the model is good. The model has been implemented in hospitals to control vaccination across the coverage area.

  11. Drug Coverage (Part D)

    Science.gov (United States)

    ... Glossary MyMedicare.gov Login Search Main Menu , collapsed Main Menu Sign Up / Change Plans Getting started with ... setup: setupNotifier, notify: notify }; lrNotifier.setup(); $("#menu-btn, li.toolbarmenu .toolbarmenu-a").click(function() { // var isExpanded = ' is ...

  12. Nonadiabatic transition path sampling

    International Nuclear Information System (INIS)

    Sherman, M. C.; Corcelli, S. A.

    2016-01-01

    Fewest-switches surface hopping (FSSH) is combined with transition path sampling (TPS) to produce a new method called nonadiabatic path sampling (NAPS). The NAPS method is validated on a model electron transfer system coupled to a Langevin bath. Numerically exact rate constants are computed using the reactive flux (RF) method over a broad range of solvent frictions that span from the energy diffusion (low friction) regime to the spatial diffusion (high friction) regime. The NAPS method is shown to quantitatively reproduce the RF benchmark rate constants over the full range of solvent friction. Integrating FSSH within the TPS framework expands the applicability of both approaches and creates a new method that will be helpful in determining detailed mechanisms for nonadiabatic reactions in the condensed-phase.

  13. PATHS groundwater hydrologic model

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, R.W.; Schur, J.A.

    1980-04-01

    A preliminary evaluation capability for two-dimensional groundwater pollution problems was developed as part of the Transport Modeling Task for the Waste Isolation Safety Assessment Program (WISAP). Our approach was to use the data limitations as a guide in setting the level of modeling detail. PATHS Groundwater Hydrologic Model is the first level (simplest) idealized hybrid analytical/numerical model for two-dimensional, saturated groundwater flow and single component transport; homogeneous geology. This document consists of the description of the PATHS groundwater hydrologic model. The preliminary evaluation capability prepared for WISAP, including the enhancements that were made because of the authors' experience using the earlier capability is described. Appendixes A through D supplement the report as follows: complete derivations of the background equations are provided in Appendix A. Appendix B is a comprehensive set of instructions for users of PATHS. It is written for users who have little or no experience with computers. Appendix C is for the programmer. It contains information on how input parameters are passed between programs in the system. It also contains program listings and test case listing. Appendix D is a definition of terms.

  14. Spreading paths in partially observed social networks

    OpenAIRE

    Onnela, Jukka-Pekka; Christakis, Nicholas A.

    2012-01-01

    Understanding how and how far information, behaviors, or pathogens spread in social networks is an important problem, having implications for both predicting the size of epidemics, as well as for planning effective interventions. There are, however, two main challenges for inferring spreading paths in real-world networks. One is the practical difficulty of observing a dynamic process on a network, and the other is the typical constraint of only partially observing a network. Using a static, s...

  15. Universal Health Coverage – The Critical Importance of Global Solidarity and Good Governance

    Science.gov (United States)

    Reis, Andreas A.

    2016-01-01

    This article provides a commentary to Ole Norheim’ s editorial entitled "Ethical perspective: Five unacceptable trade-offs on the path to universal health coverage." It reinforces its message that an inclusive, participatory process is essential for ethical decision-making and underlines the crucial importance of good governance in setting fair priorities in healthcare. Solidarity on both national and international levels is needed to make progress towards the goal of universal health coverage (UHC). PMID:27694683

  16. Shortest Paths and Vehicle Routing

    DEFF Research Database (Denmark)

    Petersen, Bjørn

    This thesis presents how to parallelize a shortest path labeling algorithm. It is shown how to handle Chvátal-Gomory rank-1 cuts in a column generation context. A Branch-and-Cut algorithm is given for the Elementary Shortest Paths Problem with Capacity Constraint. A reformulation of the Vehicle...... Routing Problem based on partial paths is presented. Finally, a practical application of finding shortest paths in the telecommunication industry is shown....

  17. Rocket Flight Path

    Directory of Open Access Journals (Sweden)

    Jamie Waters

    2014-09-01

    Full Text Available This project uses Newton’s Second Law of Motion, Euler’s method, basic physics, and basic calculus to model the flight path of a rocket. From this, one can find the height and velocity at any point from launch to the maximum altitude, or apogee. This can then be compared to the actual values to see if the method of estimation is a plausible. The rocket used for this project is modeled after Bullistic-1 which was launched by the Society of Aeronautics and Rocketry at the University of South Florida.

  18. JAVA PathFinder

    Science.gov (United States)

    Mehhtz, Peter

    2005-01-01

    JPF is an explicit state software model checker for Java bytecode. Today, JPF is a swiss army knife for all sort of runtime based verification purposes. This basically means JPF is a Java virtual machine that executes your program not just once (like a normal VM), but theoretically in all possible ways, checking for property violations like deadlocks or unhandled exceptions along all potential execution paths. If it finds an error, JPF reports the whole execution that leads to it. Unlike a normal debugger, JPF keeps track of every step how it got to the defect.

  19. Hamiltonian path integrals

    International Nuclear Information System (INIS)

    Prokhorov, L.V.

    1982-01-01

    Problems related to consideration of operator nonpermutability in Hamiltonian path integral (HPI) are considered in the review. Integrals are investigated using trajectories in configuration space (nonrelativistic quantum mechanics). Problems related to trajectory integrals in HPI phase space are discussed: the problem of operator nonpermutability consideration (extra terms problem) and corresponding equivalence rules; ambiguity of HPI usual recording; transition to curvilinear coordinates. Problem of quantization of dynamical systems with couplings has been studied. As in the case of canonical transformations, quantization of the systems with couplings of the first kind requires the consideration of extra terms

  20. Path to Prosperity

    OpenAIRE

    Wolfowitz,Paul

    2006-01-01

    Paul Wolfowitz, President of the World Bank, discussed Singapore's remarkable progress along the road from poverty to prosperity which has also been discovered by many other countries in East Asia and around the world. He spoke of how each country must find its own path for people to pursue the same dreams of the chance to go to school, the security of a good job, and the ability to provide a better future for their children. Throughout the world, and importantly in the developing world, ther...

  1. Assuring Access to Affordable Coverage

    Data.gov (United States)

    U.S. Department of Health & Human Services — Under the Affordable Care Act, millions of uninsured Americans will gain access to affordable coverage through Affordable Insurance Exchanges and improvements in...

  2. Quantifying the impact of cross coverage on physician's workload and performance in radiation oncology.

    Science.gov (United States)

    Mosaly, Prithima R; Mazur, Lukasz M; Jones, Ellen L; Hoyle, Lesley; Zagar, Timothy; Chera, Bhishamjit S; Marks, Lawrence B

    2013-01-01

    To quantitatively assess the difference in workload and performance of radiation oncology physicians during radiation therapy treatment planning tasks under the conditions of "cross coverage" versus planning a patient with whom they were familiar. Eight physicians (3 experienced faculty physicians and 5 physician residents) performed 2 cases. The first case represented a "cross-coverage" scenario where the physicians had no prior information about the case to be planned. The second exposure represented a "regular-coverage" scenario where the physicians were familiar with the patient case to be planned. Each case involved 3 tasks to be completed systematically. Workload was assessed both subjectively (perceived) using National Aeronautics and Space Administration-Task Load Index (NASA-TLX), and objectively (physiological) throughout the task using eye data (via monitoring pupil size and blink rate). Performance of each task and the case was measured using completion time. Subjective willingness to approve or disapprove the generated plan was obtained after completion of the case only. Forty-eight perceived and 48 physiological workload assessments were obtained. Overall, results revealed a significant increase in perceived workload (high NASA-TLX score) and decrease in performance (longer completion time and reduced approval rate) during cross coverage. There were nonsignificant increases in pupil diameter and decreases in the blink rate during cross-coverage versus regular-coverage scenario. In both cross-coverage and regular-coverage scenarios the level of experience did not affect workload and performance. The cross-coverage scenario significantly increases perceived workload and degrades performance versus regular coverage. Hence, to improve patient safety, efforts must be made to develop policies, standard operating procedures, and usability improvements to electronic medical record and treatment planning systems for "easier" information processing to deal with

  3. World nuclear energy paths

    International Nuclear Information System (INIS)

    Connolly, T.J.; Hansen, U.; Jaek, W.; Beckurts, K.H.

    1979-01-01

    In examing the world nuclear energy paths, the following assumptions were adopted: the world economy will grow somewhat more slowly than in the past, leading to reductions in electricity demand growth rates; national and international political impediments to the deployment of nuclear power will gradually disappear over the next few years; further development of nuclear power will proceed steadily, without serious interruption but with realistic lead times for the introduction of advanced technologies. Given these assumptions, this paper attempts a study of possible world nuclear energy developments, disaggregated on a regional and national basis. The scenario technique was used and a few alternative fuel-cycle scenarios were developed. Each is an internally consistent model of technically and economically feasible paths to the further development of nuclear power in an aggregate of individual countries and regions of the world. The main purpose of this modeling exercise was to gain some insight into the probable international locations of reactors and other nuclear facilities, the future requirements for uranium and for fuel-cycle services, and the problems of spent-fuel storage and waste management. The study also presents an assessment of the role that nuclear power might actually play in meeting future world energy demand

  4. 30 CFR 735.14 - Coverage of grants.

    Science.gov (United States)

    2010-07-01

    ... systems, including data processing systems; (6) A planning process including a data base and information... ADMINISTRATION AND ENFORCEMENT § 735.14 Coverage of grants. (a) Program development grants. An agency may use... the initial administration and enforcement grant to the extent not covered by indirect costs or other...

  5. An employer's experience with infertility coverage: a case study.

    Science.gov (United States)

    Silverberg, Kaylen; Meletiche, Dennis; Del Rosario, Gina

    2009-12-01

    A case study of Southwest Airlines, a Fortune 500 company, demonstrates that a well-designed infertility coverage plan can control resource use. This successful model could be used by employers who wish to ensure that their employees have access to high-quality, cost-effective infertility services in a managed-care environment.

  6. Optimal Path Planner for Mobile Robot in 2D Environment

    Directory of Open Access Journals (Sweden)

    Valeri Kroumov

    2004-06-01

    Full Text Available The problem of path planning for the case of a mobile robot moving in an environment filled with obstacles with known shapes and positions is studied. A path planner based on the genetic algorithm approach, which generates optimal in length path is proposed. The population member paths are generated by another algorithm, which uses for description of the obstacles an artificial annealing neural network and is based on potential field approach. The resulting path is piecewise linear with changing directions at the corners of the obstacles. Because of this feature, the inverse kinematics problems in controlling differential drive robots are simply solved: to drive the robot to some goal pose (x, y, theta, the robot can be spun in place until it is aimed at (x, y, then driven forward until it is at (x, y, and then spun in place until the required goal orientation

  7. Accelerating cleanup. Paths to closure Hanford Site

    International Nuclear Information System (INIS)

    Edwards, C.

    1998-01-01

    This document was previously referred to as the Draft 2006 Plan. As part of the DOE's national strategy, the Richland Operations Office's Paths to Closure summarizes an integrated path forward for environmental cleanup at the Hanford Site. The Hanford Site underwent a concerted effort between 1994 and 1996 to accelerate the cleanup of the Site. These efforts are reflected in the current Site Baseline. This document describes the current Site Baseline and suggests strategies for further improvements in scope, schedule and cost. The Environmental Management program decided to change the name of the draft strategy and the document describing it in response to a series of stakeholder concerns, including the practicality of achieving widespread cleanup by 2006. Also, EM was concerned that calling the document a plan could be misconstrued to be a proposal by DOE or a decision-making document. The change in name, however, does not diminish the 2006 vision. To that end, Paths to Closure retains a focus on 2006, which serves as a point in time around which objectives and goals are established

  8. Individual health insurance within the family : can subsidies promote family coverage?

    OpenAIRE

    Kanika Kapur; M. Susan Marquis; José J. Escarce

    2007-01-01

    This paper examines the role of price in health insurance coverage decisions within the family to guide policy in promoting whole family coverage. We analyze the factors that affect individual health insurance coverage among families, and explore family decisions about whom to cover and whom to leave uninsured. The analysis uses household data from California combined with abstracted individual health plan benefit and premium data. We find that premium subsidies for individual insurance would...

  9. Paths of Cultural Systems

    Directory of Open Access Journals (Sweden)

    Paul Ballonoff

    2017-12-01

    Full Text Available A theory of cultural structures predicts the objects observed by anthropologists. We here define those which use kinship relationships to define systems. A finite structure we call a partially defined quasigroup (or pdq, as stated by Definition 1 below on a dictionary (called a natural language allows prediction of certain anthropological descriptions, using homomorphisms of pdqs onto finite groups. A viable history (defined using pdqs states how an individual in a population following such history may perform culturally allowed associations, which allows a viable history to continue to survive. The vector states on sets of viable histories identify demographic observables on descent sequences. Paths of vector states on sets of viable histories may determine which histories can exist empirically.

  10. Propagators and path integrals

    Energy Technology Data Exchange (ETDEWEB)

    Holten, J.W. van

    1995-08-22

    Path-integral expressions for one-particle propagators in scalar and fermionic field theories are derived, for arbitrary mass. This establishes a direct connection between field theory and specific classical point-particle models. The role of world-line reparametrization invariance of the classical action and the implementation of the corresponding BRST-symmetry in the quantum theory are discussed. The presence of classical world-line supersymmetry is shown to lead to an unwanted doubling of states for massive spin-1/2 particles. The origin of this phenomenon is traced to a `hidden` topological fermionic excitation. A different formulation of the pseudo-classical mechanics using a bosonic representation of {gamma}{sub 5} is shown to remove these extra states at the expense of losing manifest supersymmetry. (orig.).

  11. innovation path exploration

    Directory of Open Access Journals (Sweden)

    Li Jian

    2016-01-01

    Full Text Available The world has entered the information age, all kinds of information technologies such as cloud technology, big data technology are in rapid development, and the “Internet plus” appeared. The main purpose of “Internet plus” is to provide an opportunity for the further development of the enterprise, the enterprise technology, business and other aspects of factors combine. For enterprises, grasp the “Internet plus” the impact of the market economy will undoubtedly pave the way for the future development of enterprises. This paper will be on the innovation path of the enterprise management “Internet plus” era tied you study, hope to be able to put forward some opinions and suggestions.

  12. Audit and Evaluation Plan FY 2002

    National Research Council Canada - National Science Library

    2002-01-01

    .... These projects also have been coordinated in the joint audit and inspection planning groups that address coverage in each major functional area. The plan also includes audit policy and oversight projects planned to start in FY 2002; however, intelligence coverage will be addressed separately.

  13. Vision-based map building and trajectory planning to enable autonomous flight through urban environments

    Science.gov (United States)

    Watkins, Adam S.

    The desire to use Unmanned Air Vehicles (UAVs) in a variety of complex missions has motivated the need to increase the autonomous capabilities of these vehicles. This research presents autonomous vision-based mapping and trajectory planning strategies for a UAV navigating in an unknown urban environment. It is assumed that the vehicle's inertial position is unknown because GPS in unavailable due to environmental occlusions or jamming by hostile military assets. Therefore, the environment map is constructed from noisy sensor measurements taken at uncertain vehicle locations. Under these restrictions, map construction becomes a state estimation task known as the Simultaneous Localization and Mapping (SLAM) problem. Solutions to the SLAM problem endeavor to estimate the state of a vehicle relative to concurrently estimated environmental landmark locations. The presented work focuses specifically on SLAM for aircraft, denoted as airborne SLAM, where the vehicle is capable of six degree of freedom motion characterized by highly nonlinear equations of motion. The airborne SLAM problem is solved with a variety of filters based on the Rao-Blackwellized particle filter. Additionally, the environment is represented as a set of geometric primitives that are fit to the three-dimensional points reconstructed from gathered onboard imagery. The second half of this research builds on the mapping solution by addressing the problem of trajectory planning for optimal map construction. Optimality is defined in terms of maximizing environment coverage in minimum time. The planning process is decomposed into two phases of global navigation and local navigation. The global navigation strategy plans a coarse, collision-free path through the environment to a goal location that will take the vehicle to previously unexplored or incompletely viewed territory. The local navigation strategy plans detailed, collision-free paths within the currently sensed environment that maximize local coverage

  14. Path integral in Snyder space

    Energy Technology Data Exchange (ETDEWEB)

    Mignemi, S., E-mail: smignemi@unica.it [Dipartimento di Matematica e Informatica, Università di Cagliari, Viale Merello 92, 09123 Cagliari (Italy); INFN, Sezione di Cagliari, Cittadella Universitaria, 09042 Monserrato (Italy); Štrajn, R. [Dipartimento di Matematica e Informatica, Università di Cagliari, Viale Merello 92, 09123 Cagliari (Italy); INFN, Sezione di Cagliari, Cittadella Universitaria, 09042 Monserrato (Italy)

    2016-04-29

    The definition of path integrals in one- and two-dimensional Snyder space is discussed in detail both in the traditional setting and in the first-order formalism of Faddeev and Jackiw. - Highlights: • The definition of the path integral in Snyder space is discussed using phase space methods. • The same result is obtained in the first-order formalism of Faddeev and Jackiw. • The path integral formulation of the two-dimensional Snyder harmonic oscillator is outlined.

  15. Path integral in Snyder space

    International Nuclear Information System (INIS)

    Mignemi, S.; Štrajn, R.

    2016-01-01

    The definition of path integrals in one- and two-dimensional Snyder space is discussed in detail both in the traditional setting and in the first-order formalism of Faddeev and Jackiw. - Highlights: • The definition of the path integral in Snyder space is discussed using phase space methods. • The same result is obtained in the first-order formalism of Faddeev and Jackiw. • The path integral formulation of the two-dimensional Snyder harmonic oscillator is outlined.

  16. Scots seek soft path

    International Nuclear Information System (INIS)

    Webb, T.

    1979-01-01

    Energy policy is discussed, with particular reference to Scotland. The plans for nuclear power are analyzed in comparison with developments in coal mining, use of oil and gas and other possible energy sources such as wind and wave power. Arguments against the development of nuclear power are raised on grounds of economics, employment potential, and problems of waste disposal. (U.K.)

  17. Influence of surface coverage on the chemical desorption process

    Energy Technology Data Exchange (ETDEWEB)

    Minissale, M.; Dulieu, F., E-mail: francois.dulieu@obspm.fr [LERMA, Université de Cergy Pontoise et Observatoire de Paris, UMR 8112 du CNRS. 5, mail Gay Lussac, 95031 Cergy Pontoise (France)

    2014-07-07

    In cold astrophysical environments, some molecules are observed in the gas phase whereas they should have been depleted, frozen on dust grains. In order to solve this problem, astrochemists have proposed that a fraction of molecules synthesized on the surface of dust grains could desorb just after their formation. Recently the chemical desorption process has been demonstrated experimentally, but the key parameters at play have not yet been fully understood. In this article, we propose a new procedure to analyze the ratio of di-oxygen and ozone synthesized after O atoms adsorption on oxidized graphite. We demonstrate that the chemical desorption efficiency of the two reaction paths (O+O and O+O{sub 2}) is different by one order of magnitude. We show the importance of the surface coverage: for the O+O reaction, the chemical desorption efficiency is close to 80% at zero coverage and tends to zero at one monolayer coverage. The coverage dependence of O+O chemical desorption is proved by varying the amount of pre-adsorbed N{sub 2} on the substrate from 0 to 1.5 ML. Finally, we discuss the relevance of the different physical parameters that could play a role in the chemical desorption process: binding energy, enthalpy of formation, and energy transfer from the new molecule to the surface or to other adsorbates.

  18. 5 CFR 875.414 - Will benefits be coordinated with other coverage?

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Will benefits be coordinated with other... SERVICE REGULATIONS (CONTINUED) FEDERAL LONG TERM CARE INSURANCE PROGRAM Coverage § 875.414 Will benefits be coordinated with other coverage? Yes, benefits will be coordinated with other plans, following the...

  19. 42 CFR 440.335 - Benchmark-equivalent health benefits coverage.

    Science.gov (United States)

    2010-10-01

    ...) Aggregate actuarial value. Benchmark-equivalent coverage is health benefits coverage that has an aggregate... planning services and supplies and other appropriate preventive services, as designated by the Secretary... State for purposes of comparison in establishing the aggregate actuarial value of the benchmark...

  20. 42 CFR 436.308 - Medically needy coverage of individuals under age 21.

    Science.gov (United States)

    2010-10-01

    ... THE VIRGIN ISLANDS Optional Coverage of the Medically Needy § 436.308 Medically needy coverage of... (b) of this section: (1) Who would not be covered under the mandatory medically needy group of... nursing facility services are provided under the plan to individuals within the age group selected under...

  1. Mediating Trust in Terrorism Coverage

    DEFF Research Database (Denmark)

    Mogensen, Kirsten

    crisis. While the framework is presented in the context of television coverage of a terror-related crisis situation, it can equally be used in connection with all other forms of mediated trust. Key words: National crisis, risk communication, crisis management, television coverage, mediated trust.......Mass mediated risk communication can contribute to perceptions of threats and fear of “others” and/or to perceptions of trust in fellow citizens and society to overcome problems. This paper outlines a cross-disciplinary holistic framework for research in mediated trust building during an acute...

  2. Monitoring intervention coverage in the context of universal health coverage.

    Directory of Open Access Journals (Sweden)

    Ties Boerma

    2014-09-01

    Full Text Available Monitoring universal health coverage (UHC focuses on information on health intervention coverage and financial protection. This paper addresses monitoring intervention coverage, related to the full spectrum of UHC, including health promotion and disease prevention, treatment, rehabilitation, and palliation. A comprehensive core set of indicators most relevant to the country situation should be monitored on a regular basis as part of health progress and systems performance assessment for all countries. UHC monitoring should be embedded in a broad results framework for the country health system, but focus on indicators related to the coverage of interventions that most directly reflect the results of UHC investments and strategies in each country. A set of tracer coverage indicators can be selected, divided into two groups-promotion/prevention, and treatment/care-as illustrated in this paper. Disaggregation of the indicators by the main equity stratifiers is critical to monitor progress in all population groups. Targets need to be set in accordance with baselines, historical rate of progress, and measurement considerations. Critical measurement gaps also exist, especially for treatment indicators, covering issues such as mental health, injuries, chronic conditions, surgical interventions, rehabilitation, and palliation. Consequently, further research and proxy indicators need to be used in the interim. Ideally, indicators should include a quality of intervention dimension. For some interventions, use of a single indicator is feasible, such as management of hypertension; but in many areas additional indicators are needed to capture quality of service provision. The monitoring of UHC has significant implications for health information systems. Major data gaps will need to be filled. At a minimum, countries will need to administer regular household health surveys with biological and clinical data collection. Countries will also need to improve the

  3. Maritime super Wi-Fi coverage based on TVWS

    Science.gov (United States)

    Ren, Jia; Chen, Baodan; Zhang, Yonghui; Huang, Fang

    2014-10-01

    After analyzing the occupancy and characteristics of television white space (TVWS), this paper proposes wireless broadband networking by using super Wi-Fi technology in maritime environment operating on TVWS. A sea surface channel model is developed for predicting maritime network coverage of super Wi-Fi technology. This channel model is based on Irregular Terrain Methodology (ITM) model with revised parameters and dual-path propagation effect. The simulations demonstrated that the sea surface channel model can accurately reflect the transmission loss of radio wave in TVWS.

  4. Flight Planning

    Science.gov (United States)

    1991-01-01

    Seagull Technology, Inc., Sunnyvale, CA, produced a computer program under a Langley Research Center Small Business Innovation Research (SBIR) grant called STAFPLAN (Seagull Technology Advanced Flight Plan) that plans optimal trajectory routes for small to medium sized airlines to minimize direct operating costs while complying with various airline operating constraints. STAFPLAN incorporates four input databases, weather, route data, aircraft performance, and flight-specific information (times, payload, crew, fuel cost) to provide the correct amount of fuel optimal cruise altitude, climb and descent points, optimal cruise speed, and flight path.

  5. Clustered lot quality assurance sampling to assess immunisation coverage: increasing rapidity and maintaining precision.

    Science.gov (United States)

    Pezzoli, Lorenzo; Andrews, Nick; Ronveaux, Olivier

    2010-05-01

    Vaccination programmes targeting disease elimination aim to achieve very high coverage levels (e.g. 95%). We calculated the precision of different clustered lot quality assurance sampling (LQAS) designs in computer-simulated surveys to provide local health officers in the field with preset LQAS plans to simply and rapidly assess programmes with high coverage targets. We calculated sample size (N), decision value (d) and misclassification errors (alpha and beta) of several LQAS plans by running 10 000 simulations. We kept the upper coverage threshold (UT) at 90% or 95% and decreased the lower threshold (LT) progressively by 5%. We measured the proportion of simulations with d unvaccinated individuals if the coverage was LT% (pLT) to calculate alpha (1-pLT). We divided N in clusters (between 5 and 10) and recalculated the errors hypothesising that the coverage would vary in the clusters according to a binomial distribution with preset standard deviations of 0.05 and 0.1 from the mean lot coverage. We selected the plans fulfilling these criteria: alpha LQAS plans dividing the lot in five clusters with N = 50 (5 x 10) and d = 4 to evaluate programmes with 95% coverage target and d = 7 to evaluate programmes with 90% target. These plans will considerably increase the feasibility and the rapidity of conducting the LQAS in the field.

  6. Is expanding Medicare coverage cost-effective?

    Directory of Open Access Journals (Sweden)

    Muennig Peter

    2005-03-01

    Full Text Available Abstract Background Proposals to expand Medicare coverage tend to be expensive, but the value of services purchased is not known. This study evaluates the efficiency of the average private supplemental insurance plan for Medicare recipients. Methods Data from the National Health Interview Survey, the National Death Index, and the Medical Expenditure Panel Survey were analyzed to estimate the costs, changes in life expectancy, and health-related quality of life gains associated with providing private supplemental insurance coverage for Medicare beneficiaries. Model inputs included socio-demographic, health, and health behavior characteristics. Parameter estimates from regression models were used to predict quality-adjusted life years (QALYs and costs associated with private supplemental insurance relative to Medicare only. Markov decision analysis modeling was then employed to calculate incremental cost-effectiveness ratios. Results Medicare supplemental insurance is associated with increased health care utilization, but the additional costs associated with this utilization are offset by gains in quality-adjusted life expectancy. The incremental cost-effectiveness of private supplemental insurance is approximately $24,000 per QALY gained relative to Medicare alone. Conclusion Supplemental insurance for Medicare beneficiaries is a good value, with an incremental cost-effectiveness ratio comparable to medical interventions commonly deemed worthwhile.

  7. Feasible Path Generation Using Bezier Curves for Car-Like Vehicle

    Science.gov (United States)

    Latip, Nor Badariyah Abdul; Omar, Rosli

    2017-08-01

    When planning a collision-free path for an autonomous vehicle, the main criteria that have to be considered are the shortest distance, lower computation time and completeness, i.e. a path can be found if one exists. Besides that, a feasible path for the autonomous vehicle is also crucial to guarantee that the vehicle can reach the target destination considering its kinematic constraints such as non-holonomic and minimum turning radius. In order to address these constraints, Bezier curves is applied. In this paper, Bezier curves are modeled and simulated using Matlab software and the feasibility of the resulting path is analyzed. Bezier curve is derived from a piece-wise linear pre-planned path. It is found that the Bezier curves has the capability of making the planned path feasible and could be embedded in a path planning algorithm for an autonomous vehicle with kinematic constraints. It is concluded that the length of segments of the pre-planned path have to be greater than a nominal value, derived from the vehicle wheelbase, maximum steering angle and maximum speed to ensure the path for the autonomous car is feasible.

  8. Expanding the universe of universal coverage: the population health argument for increasing coverage for immigrants.

    Science.gov (United States)

    Nandi, Arijit; Loue, Sana; Galea, Sandro

    2009-12-01

    As the US recession deepens, furthering the debate about healthcare reform is now even more important than ever. Few plans aimed at facilitating universal coverage make any mention of increasing access for uninsured non-citizens living in the US, many of whom are legally restricted from certain types of coverage. We conducted a critical review of the public health literature concerning the health status and access to health services among immigrant populations in the US. Using examples from infectious and chronic disease epidemiology, we argue that access to health services is at the intersection of the health of uninsured immigrants and the general population and that extending access to healthcare to all residents of the US, including undocumented immigrants, is beneficial from a population health perspective. Furthermore, from a health economics perspective, increasing access to care for immigrant populations may actually reduce net costs by increasing primary prevention and reducing the emphasis on emergency care for preventable conditions. It is unlikely that proposals for universal coverage will accomplish their objectives of improving population health and reducing social disparities in health if they do not address the substantial proportion of uninsured non-citizens living in the US.

  9. Two Generations of Path Dependence

    DEFF Research Database (Denmark)

    Madsen, Mogens Ove

      Even if there is no fully articulated and generally accepted theory of Path Dependence it has eagerly been taken up across a wide range of social sciences - primarily coming from economics. Path Dependence is most of all a metaphor that offers reason to believe, that some political, social...

  10. Chromatic roots and hamiltonian paths

    DEFF Research Database (Denmark)

    Thomassen, Carsten

    2000-01-01

    We present a new connection between colorings and hamiltonian paths: If the chromatic polynomial of a graph has a noninteger root less than or equal to t(n) = 2/3 + 1/3 (3)root (26 + 6 root (33)) + 1/3 (3)root (26 - 6 root (33)) = 1.29559.... then the graph has no hamiltonian path. This result...

  11. On Hilbert space of paths

    International Nuclear Information System (INIS)

    Exner, P.; Kolerov, G.I.

    1980-01-01

    A Hilbert space of paths, the elements of which are determined by trigonometric series, was proposed and used recently by Truman. This space is shown to consist precisely of all absolutely continuous paths ending in the origin with square-integrable derivatives

  12. Terrorism and nuclear damage coverage

    International Nuclear Information System (INIS)

    Horbach, N. L. J. T.; Brown, O. F.; Vanden Borre, T.

    2004-01-01

    This paper deals with nuclear terrorism and the manner in which nuclear operators can insure themselves against it, based on the international nuclear liability conventions. It concludes that terrorism is currently not covered under the treaty exoneration provisions on 'war-like events' based on an analysis of the concept on 'terrorism' and travaux preparatoires. Consequently, operators remain liable for nuclear damage resulting from terrorist acts, for which mandatory insurance is applicable. Since nuclear insurance industry looks at excluding such insurance coverage from their policies in the near future, this article aims to suggest alternative means for insurance, in order to ensure adequate compensation for innocent victims. The September 11, 2001 attacks at the World Trade Center in New York City and the Pentagon in Washington, DC resulted in the largest loss in the history of insurance, inevitably leading to concerns about nuclear damage coverage, should future such assaults target a nuclear power plant or other nuclear installation. Since the attacks, some insurers have signalled their intentions to exclude coverage for terrorism from their nuclear liability and property insurance policies. Other insurers are maintaining coverage for terrorism, but are establishing aggregate limits or sublimits and are increasing premiums. Additional changes by insurers are likely to occur. Highlighted by the September 11th events, and most recently by those in Madrid on 11 March 2004, are questions about how to define acts of terrorism and the extent to which such are covered under the international nuclear liability conventions and various domestic nuclear liability laws. Of particular concern to insurers is the possibility of coordinated simultaneous attacks on multiple nuclear facilities. This paper provides a survey of the issues, and recommendations for future clarifications and coverage options.(author)

  13. Hard paths, soft paths or no paths? Cross-cultural perceptions of water solutions

    Science.gov (United States)

    Wutich, A.; White, A. C.; White, D. D.; Larson, K. L.; Brewis, A.; Roberts, C.

    2014-01-01

    In this study, we examine how development status and water scarcity shape people's perceptions of "hard path" and "soft path" water solutions. Based on ethnographic research conducted in four semi-rural/peri-urban sites (in Bolivia, Fiji, New Zealand, and the US), we use content analysis to conduct statistical and thematic comparisons of interview data. Our results indicate clear differences associated with development status and, to a lesser extent, water scarcity. People in the two less developed sites were more likely to suggest hard path solutions, less likely to suggest soft path solutions, and more likely to see no path to solutions than people in the more developed sites. Thematically, people in the two less developed sites envisioned solutions that involve small-scale water infrastructure and decentralized, community-based solutions, while people in the more developed sites envisioned solutions that involve large-scale infrastructure and centralized, regulatory water solutions. People in the two water-scarce sites were less likely to suggest soft path solutions and more likely to see no path to solutions (but no more likely to suggest hard path solutions) than people in the water-rich sites. Thematically, people in the two water-rich sites seemed to perceive a wider array of unrealized potential soft path solutions than those in the water-scarce sites. On balance, our findings are encouraging in that they indicate that people are receptive to soft path solutions in a range of sites, even those with limited financial or water resources. Our research points to the need for more studies that investigate the social feasibility of soft path water solutions, particularly in sites with significant financial and natural resource constraints.

  14. Root coverage with bridge flap

    Directory of Open Access Journals (Sweden)

    Pushpendra Kumar Verma

    2013-01-01

    Full Text Available Gingival recession in anterior teeth is a common concern due to esthetic reasons or root sensitivity. Gingival recession, especially in multiple anterior teeth, is of huge concern due to esthetic reasons. Various mucogingival surgeries are available for root coverage. This case report presents a new bridge flap technique, which allows the dentist not only to cover the previously denuded root surfaces but also to increase the zone of attached gingiva at a single step. In this case, a coronally advanced flap along with vestibular deepening technique was used as root coverage procedure for the treatment of multiple recession-type defect. Here, vestibular deepening technique is used to increase the width of the attached gingiva. The predictability of this procedure results in an esthetically healthy periodontium, along with gain in keratinized tissue and good patient′s acceptance.

  15. -Net Approach to Sensor -Coverage

    Directory of Open Access Journals (Sweden)

    Fusco Giordano

    2010-01-01

    Full Text Available Wireless sensors rely on battery power, and in many applications it is difficult or prohibitive to replace them. Hence, in order to prolongate the system's lifetime, some sensors can be kept inactive while others perform all the tasks. In this paper, we study the -coverage problem of activating the minimum number of sensors to ensure that every point in the area is covered by at least sensors. This ensures higher fault tolerance, robustness, and improves many operations, among which position detection and intrusion detection. The -coverage problem is trivially NP-complete, and hence we can only provide approximation algorithms. In this paper, we present an algorithm based on an extension of the classical -net technique. This method gives an -approximation, where is the number of sensors in an optimal solution. We do not make any particular assumption on the shape of the areas covered by each sensor, besides that they must be closed, connected, and without holes.

  16. Perfect discretization of path integrals

    International Nuclear Information System (INIS)

    Steinhaus, Sebastian

    2012-01-01

    In order to obtain a well-defined path integral one often employs discretizations. In the case of General Relativity these generically break diffeomorphism symmetry, which has severe consequences since these symmetries determine the dynamics of the corresponding system. In this article we consider the path integral of reparametrization invariant systems as a toy example and present an improvement procedure for the discretized propagator. Fixed points and convergence of the procedure are discussed. Furthermore we show that a reparametrization invariant path integral implies discretization independence and acts as a projector onto physical states.

  17. Perfect discretization of path integrals

    Science.gov (United States)

    Steinhaus, Sebastian

    2012-05-01

    In order to obtain a well-defined path integral one often employs discretizations. In the case of General Relativity these generically break diffeomorphism symmetry, which has severe consequences since these symmetries determine the dynamics of the corresponding system. In this article we consider the path integral of reparametrization invariant systems as a toy example and present an improvement procedure for the discretized propagator. Fixed points and convergence of the procedure are discussed. Furthermore we show that a reparametrization invariant path integral implies discretization independence and acts as a projector onto physical states.

  18. [Quantification of acetabular coverage in normal adult].

    Science.gov (United States)

    Lin, R M; Yang, C Y; Yu, C Y; Yang, C R; Chang, G L; Chou, Y L

    1991-03-01

    Quantification of acetabular coverage is important and can be expressed by superimposition of cartilage tracings on the maximum cross-sectional area of the femoral head. A practical Autolisp program on PC AutoCAD has been developed by us to quantify the acetabular coverage through numerical expression of the images of computed tomography. Thirty adults (60 hips) with normal center-edge angle and acetabular index in plain X ray were randomly selected for serial drops. These slices were prepared with a fixed coordination and in continuous sections of 5 mm in thickness. The contours of the cartilage of each section were digitized into a PC computer and processed by AutoCAD programs to quantify and characterize the acetabular coverage of normal and dysplastic adult hips. We found that a total coverage ratio of greater than 80%, an anterior coverage ratio of greater than 75% and a posterior coverage ratio of greater than 80% can be categorized in a normal group. Polar edge distance is a good indicator for the evaluation of preoperative and postoperative coverage conditions. For standardization and evaluation of acetabular coverage, the most suitable parameters are the total coverage ratio, anterior coverage ratio, posterior coverage ratio and polar edge distance. However, medial coverage and lateral coverage ratios are indispensable in cases of dysplastic hip because variations between them are so great that acetabuloplasty may be impossible. This program can also be used to classify precisely the type of dysplastic hip.

  19. [Coverage by health insurance or discount cards: a household survey in the coverage area of the Family Health Strategy].

    Science.gov (United States)

    Fontenelle, Leonardo Ferreira; Camargo, Maria Beatriz Junqueira de; Bertoldi, Andréa Dâmaso; Gonçalves, Helen; Maciel, Ethel Leonor Noia; Barros, Aluísio J D

    2017-10-26

    This study was designed to assess the reasons for health insurance coverage in a population covered by the Family Health Strategy in Brazil. We describe overall health insurance coverage and according to types, and analyze its association with health-related and socio-demographic characteristics. Among the 31.3% of persons (95%CI: 23.8-39.9) who reported "health insurance" coverage, 57.0% (95%CI: 45.2-68.0) were covered only by discount cards, which do not offer any kind of coverage for medical care, but only discounts in pharmacies, clinics, and hospitals. Both for health insurance and discount cards, the most frequently cited reasons for such coverage were "to be on the safe side" and "to receive better care". Both types of coverage were associated statistically with age (+65 vs. 15-24 years: adjusted odds ratios, aOR = 2.98, 95%CI: 1.28-6.90; and aOR = 3.67; 95%CI: 2.22-6.07, respectively) and socioeconomic status (additional standard deviation: aOR = 2.25, 95%CI: 1.62-3.14; and aOR = 1.96, 95%CI: 1.34-2.97). In addition, health insurance coverage was associated with schooling (aOR = 7.59, 95%CI: 4.44-13.00) for complete University Education and aOR = 3.74 (95%CI: 1.61-8.68) for complete Secondary Education, compared to less than complete Primary Education. Meanwhile, neither health insurance nor discount card was associated with health status or number of diagnosed diseases. In conclusion, studies that aim to assess private health insurance should be planned to distinguish between discount cards and formal health insurance.

  20. An Introduction to Path Analysis

    Science.gov (United States)

    Wolfe, Lee M.

    1977-01-01

    The analytical procedure of path analysis is described in terms of its use in nonexperimental settings in the social sciences. The description assumes a moderate statistical background on the part of the reader. (JKS)

  1. Probabilistic simulation of fermion paths

    International Nuclear Information System (INIS)

    Zhirov, O.V.

    1989-01-01

    Permutation symmetry of fermion path integral allows (while spin degrees of freedom are ignored) to use in its simulation any probabilistic algorithm, like Metropolis one, heat bath, etc. 6 refs., 2 tabs

  2. 29 CFR 95.31 - Insurance coverage.

    Science.gov (United States)

    2010-07-01

    ... recipient. Federally-owned property need not be insured unless required by the terms and conditions of the... § 95.31 Insurance coverage. Recipients shall, at a minimum, provide the equivalent insurance coverage...

  3. Assessing Measurement Error in Medicare Coverage

    Data.gov (United States)

    U.S. Department of Health & Human Services — Assessing Measurement Error in Medicare Coverage From the National Health Interview Survey Using linked administrative data, to validate Medicare coverage estimates...

  4. 76 FR 7767 - Student Health Insurance Coverage

    Science.gov (United States)

    2011-02-11

    ... Student Health Insurance Coverage AGENCY: Centers for Medicare & Medicaid Services (CMS), HHS. ACTION... health insurance coverage under the Public Health Service Act and the Affordable Care Act. The proposed rule would define ``student health insurance [[Page 7768

  5. Perfect discretization of path integrals

    OpenAIRE

    Steinhaus, Sebastian

    2011-01-01

    In order to obtain a well-defined path integral one often employs discretizations. In the case of General Relativity these generically break diffeomorphism symmetry, which has severe consequences since these symmetries determine the dynamics of the corresponding system. In this article we consider the path integral of reparametrization invariant systems as a toy example and present an improvement procedure for the discretized propagator. Fixed points and convergence of the procedure are discu...

  6. Coverage of the Brazilian population 18 years and older by private health plans: an analysis of data from the World Health Survey Cobertura da população brasileira com 18 anos ou mais por plano de saúde privado: uma análise dos dados da Pesquisa Mundial de Saúde

    Directory of Open Access Journals (Sweden)

    Francisco Viacava

    2005-01-01

    Full Text Available This study analyzes data from the World Health Survey (WHS conducted in 2003, with a sample of 5,000 individuals 18 years and older. Some 24.0% of the interviewees had private health insurance, and the main variables associated with private coverage were number of household assets, age, level of education, formal employment, living in municipalities with more than 50,000 inhabitants, and good self-rated health. The socioeconomic profiles of needs for and use of health services in the population covered by private health plans are different, confirming the findings of other studies reporting that this population segment as a whole presents better health conditions and greater use of services as compared to the population without private coverage, even after adjusting for socio-demographic variables and self-rated health. The WHS data also suggest that individuals with private health plans do not always use their insurance to pay for services, except in the case of mammograms.Esse estudo analisa os dados da Pesquisa Mundial de Saúde (PMS, realizada em 2003, em uma amostra de 5 mil indivíduos com 18 anos ou mais. Cerca de 24,0% dos indivíduos entrevistados têm seguro privado de saúde, sendo que os fatores associados à posse do plano são o número de bens, idade, escolaridade, ter emprego formal, residir em municípios com menos de 50 mil habitantes e referir boa auto-avaliação do estado de saúde. Os perfis sócio-demográficos de necessidades e uso de serviços de saúde da população coberta por plano de saúde são distintos, confirmando os achados de outros trabalhos que referem que esse segmento populacional como um todo apresenta melhores condições de saúde e um maior uso de serviços em relação à população não coberta por seguro de saúde, mesmo após o controle por variáveis sócio-demográficas e a auto-avaliação do estado de saúde. Os dados da PMS também sugerem que pessoas cobertas por plano de saúde nem sempre

  7. Pension coverage among the baby boomers: initial findings from a 1993 survey.

    Science.gov (United States)

    Woods, J R

    1994-01-01

    Using data from a series of supplements to the Current Population Survey, this article presents findings on workers' coverage under employer-sponsored retirement plans in 1993, and recent trends in coverage. The analysis focuses on workers 25-54, a group that includes the baby boom generation. Among all wage and salary workers in this age range (including government employees and part-time workers), 55 percent reported participating in a retirement plan on their current primary jobs, and an additional 3 percent were covered from other jobs. After a modest decline in the early 1980's, the coverage rate has remained essentially unchanged over the past 10 years, and limited data suggest that the baby boomers are doing about as well on pension coverage as older workers at similar points in their careers. Beneath this relative stability in overall coverage, however, at least two important changes have occurred: a significant narrowing of the gender gap in coverage and a shift in types of retirement plans. Increasing numbers of workers are being covered solely by 401(k)-type plans, a development that raises new uncertainties about the form and amount of future benefits. On the other hand, limited data in this study suggest that 401(k) plans may be serving their intended purpose for the majority of workers who have them.

  8. Path integration in conical space

    International Nuclear Information System (INIS)

    Inomata, Akira; Junker, Georg

    2012-01-01

    Quantum mechanics in conical space is studied by the path integral method. It is shown that the curvature effect gives rise to an effective potential in the radial path integral. It is further shown that the radial path integral in conical space can be reduced to a form identical with that in flat space when the discrete angular momentum of each partial wave is replaced by a specific non-integral angular momentum. The effective potential is found proportional to the squared mean curvature of the conical surface embedded in Euclidean space. The path integral calculation is compatible with the Schrödinger equation modified with the Gaussian and the mean curvature. -- Highlights: ► We study quantum mechanics on a cone by the path integral approach. ► The path integral depends only on the metric and the curvature effect is built in. ► The approach is consistent with the Schrödinger equation modified by an effective potential. ► The effective potential is found to be of the “Jensen–Koppe” and “da Costa” type.

  9. Path integrals on curved manifolds

    International Nuclear Information System (INIS)

    Grosche, C.; Steiner, F.

    1987-01-01

    A general framework for treating path integrals on curved manifolds is presented. We also show how to perform general coordinate and space-time transformations in path integrals. The main result is that one has to subtract a quantum correction ΔV ∝ ℎ 2 from the classical Lagrangian L, i.e. the correct effective Lagrangian to be used in the path integral is L eff = L-ΔV. A general prescription for calculating the quantum correction ΔV is given. It is based on a canonical approach using Weyl-ordering and the Hamiltonian path integral defined by the midpoint prescription. The general framework is illustrated by several examples: The d-dimensional rotator, i.e. the motion on the sphere S d-1 , the path integral in d-dimensional polar coordinates, the exact treatment of the hydrogen atom in R 2 and R 3 by performing a Kustaanheimo-Stiefel transformation, the Langer transformation and the path integral for the Morse potential. (orig.)

  10. Indonesia's road to universal health coverage: a political journey.

    Science.gov (United States)

    Pisani, Elizabeth; Olivier Kok, Maarten; Nugroho, Kharisma

    2017-03-01

    In 2013 Indonesia, the world's fourth most populous country, declared that it would provide affordable health care for all its citizens within seven years. This crystallised an ambition first enshrined in law over five decades earlier, but never previously realised. This paper explores Indonesia's journey towards universal health coverage (UHC) from independence to the launch of a comprehensive health insurance scheme in January 2014. We find that Indonesia's path has been determined largely by domestic political concerns – different groups obtained access to healthcare as their socio-political importance grew. A major inflection point occurred following the Asian financial crisis of 1997. To stave off social unrest, the government provided health coverage for the poor for the first time, creating a path dependency that influenced later policy choices. The end of this programme coincided with decentralisation, leading to experimentation with several different models of health provision at the local level. When direct elections for local leaders were introduced in 2005, popular health schemes led to success at the polls. UHC became an electoral asset, moving up the political agenda. It also became contested, with national policy-makers appropriating health insurance programmes that were first developed locally, and taking credit for them. The Indonesian experience underlines the value of policy experimentation, and of a close understanding of the contextual and political factors that drive successful UHC models at the local level. Specific drivers of success and failure should be taken into account when scaling UHC to the national level. In the Indonesian example, UHC became possible when the interests of politically and economically influential groups were either satisfied or neutralised. While technical considerations took a back seat to political priorities in developing the structures for health coverage nationally, they will have to be addressed going forward

  11. Achieving Crossed Strong Barrier Coverage in Wireless Sensor Network.

    Science.gov (United States)

    Han, Ruisong; Yang, Wei; Zhang, Li

    2018-02-10

    Barrier coverage has been widely used to detect intrusions in wireless sensor networks (WSNs). It can fulfill the monitoring task while extending the lifetime of the network. Though barrier coverage in WSNs has been intensively studied in recent years, previous research failed to consider the problem of intrusion in transversal directions. If an intruder knows the deployment configuration of sensor nodes, then there is a high probability that it may traverse the whole target region from particular directions, without being detected. In this paper, we introduce the concept of crossed barrier coverage that can overcome this defect. We prove that the problem of finding the maximum number of crossed barriers is NP-hard and integer linear programming (ILP) is used to formulate the optimization problem. The branch-and-bound algorithm is adopted to determine the maximum number of crossed barriers. In addition, we also propose a multi-round shortest path algorithm (MSPA) to solve the optimization problem, which works heuristically to guarantee efficiency while maintaining near-optimal solutions. Several conventional algorithms for finding the maximum number of disjoint strong barriers are also modified to solve the crossed barrier problem and for the purpose of comparison. Extensive simulation studies demonstrate the effectiveness of MSPA.

  12. Universal Health Coverage: A burning need for developing countries

    OpenAIRE

    Zaman, Sojib Bin; Hossain, Naznin

    2017-01-01

    The term of universal health coverage (UHC) are getting popularity among the countries who have not yet attained it. Majority of the developing countries are planning to implement the UHC to protect the vulnerable citizen who cannot afford to buy the health services. Poor people living in developing countries, where there is no UHC, are bereft of getting equal health care. They have to bear a significant amount of health cost in buying different services which often causes catastrophic expend...

  13. Universal Health Coverage for Schizophrenia: A Global Mental Health Priority

    OpenAIRE

    Patel, Vikram

    2015-01-01

    The growing momentum towards a global consensus on universal health coverage, alongside an acknowledgment of the urgency and importance of a comprehensive mental health action plan, offers a unique opportunity for a substantial scale-up of evidence-based interventions and packages of care for a range of mental disorders in all countries. There is a robust evidence base testifying to the effectiveness of drug and psychosocial interventions for people with schizophrenia and to the feasibility, ...

  14. 5 CFR 890.1106 - Coverage.

    Science.gov (United States)

    2010-01-01

    ... family member is an individual whose relationship to the enrollee meets the requirements of 5 U.S.C. 8901... EMPLOYEES HEALTH BENEFITS PROGRAM Temporary Continuation of Coverage § 890.1106 Coverage. (a) Type of enrollment. An individual who enrolls under this subpart may elect coverage for self alone or self and family...

  15. 40 CFR 51.356 - Vehicle coverage.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Vehicle coverage. 51.356 Section 51.356....356 Vehicle coverage. The performance standard for enhanced I/M programs assumes coverage of all 1968 and later model year light duty vehicles and light duty trucks up to 8,500 pounds GVWR, and includes...

  16. 29 CFR 801.3 - Coverage.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Coverage. 801.3 Section 801.3 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR OTHER LAWS APPLICATION OF THE EMPLOYEE POLYGRAPH PROTECTION ACT OF 1988 General § 801.3 Coverage. (a) The coverage of the Act extends to “any...

  17. Medicare Plan Finder and Compare

    Data.gov (United States)

    U.S. Department of Health & Human Services — You have the option to complete a general or personalized plan search. A personalized search may provide you with more accurate cost estimates and coverage...

  18. Path Searching Based Fault Automated Recovery Scheme for Distribution Grid with DG

    Science.gov (United States)

    Xia, Lin; Qun, Wang; Hui, Xue; Simeng, Zhu

    2016-12-01

    Applying the method of path searching based on distribution network topology in setting software has a good effect, and the path searching method containing DG power source is also applicable to the automatic generation and division of planned islands after the fault. This paper applies path searching algorithm in the automatic division of planned islands after faults: starting from the switch of fault isolation, ending in each power source, and according to the line load that the searching path traverses and the load integrated by important optimized searching path, forming optimized division scheme of planned islands that uses each DG as power source and is balanced to local important load. Finally, COBASE software and distribution network automation software applied are used to illustrate the effectiveness of the realization of such automatic restoration program.

  19. China's new path

    International Nuclear Information System (INIS)

    Liu Yingling

    2008-01-01

    The recent policy tools have also consolidated and advanced traditional renewable energy industries, including hydropower and solar thermal panels, where China has already been a world leader. The technologies are comparatively simple and low-cost, and the country has developed fairly strong construction, manufacturing and installation industries for both sources. They are still dominant in China's renewable energy use, and are expected to see continuous strong growth. Hydropower accounts for about two-thirds of China's current renewable energy use. It has grown by over 8 per cent annually from 2002 to 2006, and installed capacity will reach 190 GW by 2010 and 300 GW by 2020. China also has nearly two-thirds of the world's solar hot water capacity: more than one in every ten households bathe in water heated by the sun. Such solar thermal has witnessed 20-25 per cent annual growth in recent years, with installed capacity rising from 35 million square metres in 2000 to 100 million square metres by the end of 2006. The government aims for 150 million square metres by 2010 and double that figure by 2020. A more optimistic prediction envisages 800 million square metres installed capacity by 2030, which would mean that more than half of all Chinese households would be using solar energy for water heating. Renewable energy has become a strategic industry in China. The country has more than 50 domestic wind turbine manufacturers, over 15 major solar cell manufacturers and roughly 50 companies constructing, expanding or planning for polysilicon production lines, the key components for solar PV systems. Those two industries together employ some 80,000 people. The country also has thousands of hydropower manufacturers and engineering and design firms. More than a thousand solar water heater manufacturers throughout the country - and associated design, installation and service providers - provide some 600,000 jobs. As renewable industries are scaled up, costs will come down

  20. Navigating the Path to a Biomedical Science Career

    Science.gov (United States)

    Zimmerman, Andrea McNeely

    The number of biomedical PhD scientists being trained and graduated far exceeds the number of academic faculty positions and academic research jobs. If this trend is compelling biomedical PhD scientists to increasingly seek career paths outside of academia, then more should be known about their intentions, desires, training experiences, and career path navigation. Therefore, the purpose of this study was to understand the process through which biomedical PhD scientists are trained and supported for navigating future career paths. In addition, the study sought to determine whether career development support efforts and opportunities should be redesigned to account for the proportion of PhD scientists following non-academic career pathways. Guided by the social cognitive career theory (SCCT) framework this study sought to answer the following central research question: How does a southeastern tier 1 research university train and support its biomedical PhD scientists for navigating their career paths? Key findings are: Many factors influence PhD scientists' career sector preference and job search process, but the most influential were relationships with faculty, particularly the mentor advisor; Planned activities are a significant aspect of the training process and provide skills for career success; and Planned activities provided skills necessary for a career, but influential factors directed the career path navigated. Implications for practice and future research are discussed.

  1. Camera Coverage Estimation Based on Multistage Grid Subdivision

    Directory of Open Access Journals (Sweden)

    Meizhen Wang

    2017-04-01

    Full Text Available Visual coverage is one of the most important quality indexes for depicting the usability of an individual camera or camera network. It is the basis for camera network deployment, placement, coverage-enhancement, planning, etc. Precision and efficiency are critical influences on applications, especially those involving several cameras. This paper proposes a new method to efficiently estimate superior camera coverage. First, the geographic area that is covered by the camera and its minimum bounding rectangle (MBR without considering obstacles is computed using the camera parameters. Second, the MBR is divided into grids using the initial grid size. The status of the four corners of each grid is estimated by a line of sight (LOS algorithm. If the camera, considering obstacles, covers a corner, the status is represented by 1, otherwise by 0. Consequently, the status of a grid can be represented by a code that is a combination of 0s or 1s. If the code is not homogeneous (not four 0s or four 1s, the grid will be divided into four sub-grids until the sub-grids are divided into a specific maximum level or their codes are homogeneous. Finally, after performing the process above, total camera coverage is estimated according to the size and status of all grids. Experimental results illustrate that the proposed method’s accuracy is determined by the method that divided the coverage area into the smallest grids at the maximum level, while its efficacy is closer to the method that divided the coverage area into the initial grids. It considers both efficiency and accuracy. The initial grid size and maximum level are two critical influences on the proposed method, which can be determined by weighing efficiency and accuracy.

  2. Achieving and Sustaining Universal Health Coverage: Fiscal Reform of the National Health Insurance in Taiwan.

    Science.gov (United States)

    Lan, Jesse Yu-Chen

    2017-12-01

    The paper discusses the expansion of the universal health coverage (UHC) in Taiwan through the establishment of National Health Insurance (NHI), and the fiscal crisis it caused. Two key questions are addressed: How did the NHI gradually achieve universal coverage, and yet cause Taiwanese health spending to escalate to fiscal crisis? What measures have been taken to reform the NHI finance and achieve moderate success to date? The main argument of this paper is that the Taiwanese Government did try to implement various reforms to save costs and had moderate success, but the path-dependent process of reform does not allow increasing contribution rates significantly and thereby makes sustainability challenging.

  3. Medicaid Coverage of Methadone Maintenance and the Use of Opioid Agonist Therapy Among Pregnant Women in Specialty Treatment.

    Science.gov (United States)

    Bachhuber, Marcus A; Mehta, Pooja K; Faherty, Laura J; Saloner, Brendan

    2017-12-01

    Opioid agonist therapy (OAT) is the standard of care for pregnant women with opioid use disorder (OUD). Medicaid coverage policies may strongly influence OAT use in this group. To examine the association between Medicaid coverage of methadone maintenance and planned use of OAT in the publicly funded treatment system. Retrospective cross-sectional analysis of treatment admissions in 30 states extracted from the Treatment Episode Data Set (2013 and 2014). Medicaid-insured pregnant women with OUD (n=3354 treatment admissions). The main outcome measure was planned use of OAT on admission. The main exposure was state Medicaid coverage of methadone maintenance. Using multivariable logistic regression models adjusting for sociodemographic, substance use, and treatment characteristics, we compared the probability of planned OAT use in states with Medicaid coverage of methadone maintenance versus states without coverage. A total of 71% of pregnant women admitted to OUD treatment were 18-29 years old, 85% were white non-Hispanic, and 56% used heroin. Overall, 74% of admissions occurred in the 18 states with Medicaid coverage of methadone maintenance and 53% of admissions involved planned use of OAT. Compared with states without Medicaid coverage of methadone maintenance, admissions in states with coverage were significantly more likely to involve planned OAT use (adjusted difference: 32.9 percentage points, 95% confidence interval, 19.2-46.7). Including methadone maintenance in the Medicaid benefit is essential to increasing OAT among pregnant women with OUD and should be considered a key policy strategy to enhance outcomes for mothers and newborns.

  4. Path integration on hyperbolic spaces

    Energy Technology Data Exchange (ETDEWEB)

    Grosche, C [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    1991-11-01

    Quantum mechanics on the hyperbolic spaces of rank one is discussed by path integration technique. Hyperbolic spaces are multi-dimensional generalisation of the hyperbolic plane, i.e. the Poincare upper half-plane endowed with a hyperbolic geometry. We evalute the path integral on S{sub 1} {approx equal} SO (n,1)/SO(n) and S{sub 2} {approx equal} SU(n,1)/S(U(1) x U(n)) in a particular coordinate system, yielding explicitly the wave-functions and the energy spectrum. Futhermore we can exploit a general property of all these spaces, namely that they can be parametrized by a pseudopolar coordinate system. This allows a separation in path integration over spheres and an additional path integration over the remaining hyperbolic coordinate, yielding effectively a path integral for a modified Poeschl-Teller potential. Only continuous spectra can exist in all the cases. For all the hyperbolic spaces of rank one we find a general formula for the largest lower bound (zero-point energy) of the spectrum which is given by E{sub O} = h{sup 2} /8m(m{sub {alpha}} +2m{sub 2} {alpha}){sup 2} (m {alpha} and m{sub 2}{alpha} denote the dimension of the root subspace corresponding to the roots {alpha} and 2{alpha}, respectively). I also discuss the case, where a constant magnetic field on H{sup n} is incorporated. (orig.).

  5. Path integration on hyperbolic spaces

    International Nuclear Information System (INIS)

    Grosche, C.

    1991-11-01

    Quantum mechanics on the hyperbolic spaces of rank one is discussed by path integration technique. Hyperbolic spaces are multi-dimensional generalisation of the hyperbolic plane, i.e. the Poincare upper half-plane endowed with a hyperbolic geometry. We evalute the path integral on S 1 ≅ SO (n,1)/SO(n) and S 2 ≅ SU(n,1)/S[U(1) x U(n)] in a particular coordinate system, yielding explicitly the wave-functions and the energy spectrum. Futhermore we can exploit a general property of all these spaces, namely that they can be parametrized by a pseudopolar coordinate system. This allows a separation in path integration over spheres and an additional path integration over the remaining hyperbolic coordinate, yielding effectively a path integral for a modified Poeschl-Teller potential. Only continuous spectra can exist in all the cases. For all the hyperbolic spaces of rank one we find a general formula for the largest lower bound (zero-point energy) of the spectrum which is given by E O = h 2 /8m(m α +2m 2 α) 2 (m α and m 2 α denote the dimension of the root subspace corresponding to the roots α and 2α, respectively). I also discuss the case, where a constant magnetic field on H n is incorporated. (orig.)

  6. 75 FR 51831 - Request for Measures of Health Plan Efforts To Address Health Plan Members' Health Literacy Needs

    Science.gov (United States)

    2010-08-23

    ... and health plans. The results of the planned survey may become an important source of information for... services and nurse advice lines, the quality and accessibility of health plan information on coverage...

  7. On the Meta Distribution of Coverage Probability in Uplink Cellular Networks

    KAUST Repository

    Elsawy, Hesham

    2017-04-07

    This letter studies the meta distribution of coverage probability (CP), within a stochastic geometry framework, for cellular uplink transmission with fractional path-loss inversion power control. Using the widely accepted Poisson point process (PPP) for modeling the spatial locations of base stations (BSs), we obtain the percentiles of users that achieve a target uplink CP over an arbitrary, but fixed, realization of the PPP. To this end, the effect of the users activity factor (p) and the path-loss compensation factor () on the uplink performance are analyzed. The results show that decreasing p and/or increasing reduce the CP variation around the spatially averaged value.

  8. 42 CFR 423.464 - Coordination of benefits with other providers of prescription drug coverage.

    Science.gov (United States)

    2010-10-01

    ... fees. CMS may impose user fees on Part D plans for the transmittal of information necessary for benefit...) Provides supplemental drug coverage to individuals based on financial need, age, or medical condition, and... effective exchange of information and coordination between such plan and SPAPs and entities providing other...

  9. 77 FR 8667 - Summary of Benefits and Coverage and Uniform Glossary

    Science.gov (United States)

    2012-02-14

    ... health plan. There are three general scenarios under which an SBC will be provided: (1) By a group health... enrolled, a plan or issuer generally has up to seven business days (rather than seven calendar days, as... comments regarding the coverage examples. Some comments supported the general approach in the proposed...

  10. Path Integrals in Quantum Mechanics

    International Nuclear Information System (INIS)

    Louko, J

    2005-01-01

    Jean Zinn-Justin's textbook Path Integrals in Quantum Mechanics aims to familiarize the reader with the path integral as a calculational tool in quantum mechanics and field theory. The emphasis is on quantum statistical mechanics, starting with the partition function Tr exp(-β H) and proceeding through the diffusion equation to barrier penetration problems and their semiclassical limit. The 'real time' path integral is defined via analytic continuation and used for the path-integral representation of the nonrelativistic S-matrix and its perturbative expansion. Holomorphic and Grassmannian path integrals are introduced and applied to nonrelativistic quantum field theory. There is also a brief discussion of path integrals in phase space. The introduction includes a brief historical review of path integrals, supported by a bibliography with some 40 entries. As emphasized in the introduction, mathematical rigour is not a central issue in the book. This allows the text to present the calculational techniques in a very readable manner: much of the text consists of worked-out examples, such as the quartic anharmonic oscillator in the barrier penetration chapter. At the end of each chapter there are exercises, some of which are of elementary coursework type, but the majority are more in the style of extended examples. Most of the exercises indeed include the solution or a sketch thereof. The book assumes minimal previous knowledge of quantum mechanics, and some basic quantum mechanical notation is collected in an appendix. The material has a large overlap with selected chapters in the author's thousand-page textbook Quantum Field Theory and Critical Phenomena (2002 Oxford: Clarendon). The stand-alone scope of the present work has, however, allowed a more focussed organization of this material, especially in the chapters on, respectively, holomorphic and Grassmannian path integrals. In my view the book accomplishes its aim admirably and is eminently usable as a textbook

  11. From path integrals to anyons

    International Nuclear Information System (INIS)

    Canright, G.S.

    1992-01-01

    I offer a pedagogical review of the homotopy arguments for fractional statistics in two dimensions. These arguments arise naturally in path-integral language since they necessarily consider the properties of paths rather than simply permutations. The braid group replaces the permutation group as the basic structure for quantum statistics; hence properties of the braid group on several surfaces are briefly discussed. Finally, the question of multiple (real-space) occupancy is addressed; I suggest that the ''traditional'' treatment of this question (ie, an assumption that many-anyon wavefunctions necessarily vanish for multiple occupancy) needs reexamination

  12. Isomorphisms and traversability of directed path graphs

    NARCIS (Netherlands)

    Broersma, Haitze J.; Li, Xueliang; Li, X.

    1998-01-01

    The concept of a line digraph is generalized to that of a directed path graph. The directed path graph $\\forw P_k(D)$ of a digraph $D$ is obtained by representing the directed paths on $k$ vertices of $D$ by vertices. Two vertices are joined by an arc whenever the corresponding directed paths in $D$

  13. A Collision-Free G2 Continuous Path-Smoothing Algorithm Using Quadratic Polynomial Interpolation

    Directory of Open Access Journals (Sweden)

    Seong-Ryong Chang

    2014-12-01

    Full Text Available Most path-planning algorithms are used to obtain a collision-free path without considering continuity. On the other hand, a continuous path is needed for stable movement. In this paper, the searched path was converted into a G2 continuous path using the modified quadratic polynomial and membership function interpolation algorithm. It is simple, unique and provides a good geometric interpretation. In addition, a collision-checking and improvement algorithm is proposed. The collision-checking algorithm can check the collisions of a smoothed path. If collisions are detected, the collision improvement algorithm modifies the collision path to a collision-free path. The collision improvement algorithm uses a geometric method. This method uses the perpendicular line between a collision position and the collision piecewise linear path. The sub-waypoint is added, and the QPMI algorithm is applied again. As a result, the collision-smoothed path is converted into a collision-free smooth path without changing the continuity.

  14. Disparities in Private Health Insurance Coverage of Skilled Care

    Directory of Open Access Journals (Sweden)

    Stacey A. Tovino

    2017-10-01

    Full Text Available This article compares and contrasts public and private health insurance coverage of skilled medical rehabilitation, including cognitive rehabilitation, physical therapy, occupational therapy, speech-language pathology, and skilled nursing services (collectively, skilled care. As background, prior scholars writing in this area have focused on Medicare coverage of skilled care and have challenged coverage determinations limiting Medicare coverage to beneficiaries who are able to demonstrate improvement in their conditions within a specific period of time (the Improvement Standard. By and large, these scholars have applauded the settlement agreement approved on 24 January 2013, by the U.S. District Court for the District of Vermont in Jimmo v. Sebelius (Jimmo, as well as related motions, rulings, orders, government fact sheets, and Medicare program manual statements clarifying that Medicare covers skilled care that is necessary to prevent or slow a beneficiary’s deterioration or to maintain a beneficiary at his or her maximum practicable level of function even though no further improvement in the beneficiary’s condition is expected. Scholars who have focused on beneficiaries who have suffered severe brain injuries, in particular, have framed public insurance coverage of skilled brain rehabilitation as an important civil, disability, and educational right. Given that approximately two-thirds of Americans with health insurance are covered by private health insurance and that many private health plans continue to require their insureds to demonstrate improvement within a short period of time to obtain coverage of skilled care, scholarship assessing private health insurance coverage of skilled care is important but noticeably absent from the literature. This article responds to this gap by highlighting state benchmark plans’ and other private health plans’ continued use of the Improvement Standard in skilled care coverage decisions and

  15. Data Science in Radiology: A Path Forward.

    Science.gov (United States)

    Aerts, Hugo J W L

    2018-02-01

    Artificial intelligence (AI), especially deep learning, has the potential to fundamentally alter clinical radiology. AI algorithms, which excel in quantifying complex patterns in data, have shown remarkable progress in applications ranging from self-driving cars to speech recognition. The AI application within radiology, known as radiomics, can provide detailed quantifications of the radiographic characteristics of underlying tissues. This information can be used throughout the clinical care path to improve diagnosis and treatment planning, as well as assess treatment response. This tremendous potential for clinical translation has led to a vast increase in the number of research studies being conducted in the field, a number that is expected to rise sharply in the future. Many studies have reported robust and meaningful findings; however, a growing number also suffer from flawed experimental or analytic designs. Such errors could not only result in invalid discoveries, but also may lead others to perpetuate similar flaws in their own work. This perspective article aims to increase awareness of the issue, identify potential reasons why this is happening, and provide a path forward. Clin Cancer Res; 24(3); 532-4. ©2017 AACR . ©2017 American Association for Cancer Research.

  16. Gibbon travel paths are goal oriented.

    Science.gov (United States)

    Asensio, Norberto; Brockelman, Warren Y; Malaivijitnond, Suchinda; Reichard, Ulrich H

    2011-05-01

    Remembering locations of food resources is critical for animal survival. Gibbons are territorial primates which regularly travel through small and stable home ranges in search of preferred, limited and patchily distributed resources (primarily ripe fruit). They are predicted to profit from an ability to memorize the spatial characteristics of their home range and may increase their foraging efficiency by using a 'cognitive map' either with Euclidean or with topological properties. We collected ranging and feeding data from 11 gibbon groups (Hylobates lar) to test their navigation skills and to better understand gibbons' 'spatial intelligence'. We calculated the locations at which significant travel direction changes occurred using the change-point direction test and found that these locations primarily coincided with preferred fruit sources. Within the limits of biologically realistic visibility distances observed, gibbon travel paths were more efficient in detecting known preferred food sources than a heuristic travel model based on straight travel paths in random directions. Because consecutive travel change-points were far from the gibbons' sight, planned movement between preferred food sources was the most parsimonious explanation for the observed travel patterns. Gibbon travel appears to connect preferred food sources as expected under the assumption of a good mental representation of the most relevant sources in a large-scale space.

  17. Acquisition Path Analysis for a SFR Fuel Manufacturing Facility

    Energy Technology Data Exchange (ETDEWEB)

    Chang, H. L.; Kwon, E. H.; Ahn, S. K.; Ko, W. I.; Kim, H. D. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    The coarse acquisition path analysis does not claim to be complete, but it identifies plausible acquisition paths detailed enough to show that the acquisition path analysis can provide reasonable insights regarding the safeguardability assessment, and demonstrates the availability of safeguards tools and measures, although not complete, required for the implementation of effective and efficient safeguards, including the coverage of the nuclear energy system (NES) by multiple intrinsic features and extrinsic measures. It also identifies strengths, weaknesses and gaps of a system in the area of proliferation resistance in a generally understandable form. The acquisition path analysis demonstrates that all acceptance limits for the safeguardability, in principle, are met although the acceptance limit for the efficiency of the IAEA safeguards can be answered only at the end of the Safeguards-by-Design process, including interaction with IAEA operations. However, procedures for destructive assay (DA) for the verification by the IAEA are not defined. Target values for non-destructive assay (NDA) for this type of nuclear material are also not defined. Therefore, there is a need to finish demonstrations of NDA measurements on novel material types and material flows. The acquisition path analysis also shows some concerns that need to be assured in the system design process: e. g., the ID number of all storage containers in all storage positions can be read or checked without moving the storage container, transfer of TRU fuel and heel/scrap (product stream) should be strictly separated from transfer routes for waste, to make the transfer of TRU fuel and heel/scrap into waste container impossible, etc.

  18. Your Medicare Coverage: Durable Medical Equipment (DME) Coverage

    Science.gov (United States)

    ... Glossary MyMedicare.gov Login Search Main Menu , collapsed Main Menu Sign Up / Change Plans Getting started with ... setup: setupNotifier, notify: notify }; lrNotifier.setup(); $("#menu-btn, li.toolbarmenu .toolbarmenu-a").click(function() { // var isExpanded = ' is ...

  19. Qualification paths of adult educators in Sweden and Denmark

    DEFF Research Database (Denmark)

    Andersson, Per; Köpsén, Susanne; Larson, Anne

    2013-01-01

    fields of education and training. In this study, we analyse the qualification paths, or learning trajectories, of prospective adult educators in Sweden and Denmark. The analysis is based on narrative interviews with 29 students in training to become adult educators. The career paths of adult educators...... are often long and winding roads. Becoming an adult educator could be their primary desire, but it could also be their ‘Plan B’, a second choice. Individual motives and external demands interact in the professionalisation process. A shift in focus from teaching subject and methods to teaching context...... and the relation to the learners is part of the professional development. Finally, we argue that both academic studies and hands-on work in the adult education community are crucial parts of the adult educator’s qualification path....

  20. Cholera in Haiti: Reproductive numbers and vaccination coverage estimates

    Science.gov (United States)

    Mukandavire, Zindoga; Smith, David L.; Morris, J. Glenn, Jr.

    2013-01-01

    Cholera reappeared in Haiti in October, 2010 after decades of absence. Cases were first detected in Artibonite region and in the ensuing months the disease spread to every department in the country. The rate of increase in the number of cases at the start of epidemics provides valuable information about the basic reproductive number (). Quantitative analysis of such data gives useful information for planning and evaluating disease control interventions, including vaccination. Using a mathematical model, we fitted data on the cumulative number of reported hospitalized cholera cases in Haiti. varied by department, ranging from 1.06 to 2.63. At a national level, 46% vaccination coverage would result in an () cholera vaccines in endemic and non-endemic regions, our results suggest that moderate cholera vaccine coverage would be an important element of disease control in Haiti.

  1. DiversePathsJ: diverse shortest paths for bioimage analysis.

    Science.gov (United States)

    Uhlmann, Virginie; Haubold, Carsten; Hamprecht, Fred A; Unser, Michael

    2018-02-01

    We introduce a formulation for the general task of finding diverse shortest paths between two end-points. Our approach is not linked to a specific biological problem and can be applied to a large variety of images thanks to its generic implementation as a user-friendly ImageJ/Fiji plugin. It relies on the introduction of additional layers in a Viterbi path graph, which requires slight modifications to the standard Viterbi algorithm rules. This layered graph construction allows for the specification of various constraints imposing diversity between solutions. The software allows obtaining a collection of diverse shortest paths under some user-defined constraints through a convenient and user-friendly interface. It can be used alone or be integrated into larger image analysis pipelines. http://bigwww.epfl.ch/algorithms/diversepathsj. michael.unser@epfl.ch or fred.hamprecht@iwr.uni-heidelberg.de. Supplementary data are available at Bioinformatics online. © The Author(s) 2017. Published by Oxford University Press.

  2. Costs in the coverage gap

    Science.gov (United States)

    ... Glossary MyMedicare.gov Login Search Main Menu , collapsed Main Menu Sign Up / Change Plans Getting started with ... setup: setupNotifier, notify: notify }; lrNotifier.setup(); $("#menu-btn, li.toolbarmenu .toolbarmenu-a").click(function() { // var isExpanded = ' is ...

  3. Travel path and transport mode identification method using ''less-frequently-detected'' position data

    International Nuclear Information System (INIS)

    Shimizu, T; Yamaguchi, T; Ai, H; Katagiri, Y; Kawase, J

    2014-01-01

    This study aims to seek method on travel path and transport mode identification in case positions of travellers are detected in low frequency. The survey in which ten test travellers with GPS logger move around Tokyo city centre was conducted. Travel path datasets of each traveller in which position data are selected every five minutes are processed from our survey data. Coverage index analysis based on the buffer analysis using GIS software is conducted. The condition and possibility to identify a path and a transport mode used are discussed

  4. TU-AB-BRB-00: New Methods to Ensure Target Coverage

    International Nuclear Information System (INIS)

    2015-01-01

    The accepted clinical method to accommodate targeting uncertainties inherent in fractionated external beam radiation therapy is to utilize GTV-to-CTV and CTV-to-PTV margins during the planning process to design a PTV-conformal static dose distribution on the planning image set. Ideally, margins are selected to ensure a high (e.g. >95%) target coverage probability (CP) in spite of inherent inter- and intra-fractional positional variations, tissue motions, and initial contouring uncertainties. Robust optimization techniques, also known as probabilistic treatment planning techniques, explicitly incorporate the dosimetric consequences of targeting uncertainties by including CP evaluation into the planning optimization process along with coverage-based planning objectives. The treatment planner no longer needs to use PTV and/or PRV margins; instead robust optimization utilizes probability distributions of the underlying uncertainties in conjunction with CP-evaluation for the underlying CTVs and OARs to design an optimal treated volume. This symposium will describe CP-evaluation methods as well as various robust planning techniques including use of probability-weighted dose distributions, probability-weighted objective functions, and coverage optimized planning. Methods to compute and display the effect of uncertainties on dose distributions will be presented. The use of robust planning to accommodate inter-fractional setup uncertainties, organ deformation, and contouring uncertainties will be examined as will its use to accommodate intra-fractional organ motion. Clinical examples will be used to inter-compare robust and margin-based planning, highlighting advantages of robust-plans in terms of target and normal tissue coverage. Robust-planning limitations as uncertainties approach zero and as the number of treatment fractions becomes small will be presented, as well as the factors limiting clinical implementation of robust planning. Learning Objectives: To understand

  5. Stochastic control with rough paths

    International Nuclear Information System (INIS)

    Diehl, Joscha; Friz, Peter K.; Gassiat, Paul

    2017-01-01

    We study a class of controlled differential equations driven by rough paths (or rough path realizations of Brownian motion) in the sense of Lyons. It is shown that the value function satisfies a HJB type equation; we also establish a form of the Pontryagin maximum principle. Deterministic problems of this type arise in the duality theory for controlled diffusion processes and typically involve anticipating stochastic analysis. We make the link to old work of Davis and Burstein (Stoch Stoch Rep 40:203–256, 1992) and then prove a continuous-time generalization of Roger’s duality formula [SIAM J Control Optim 46:1116–1132, 2007]. The generic case of controlled volatility is seen to give trivial duality bounds, and explains the focus in Burstein–Davis’ (and this) work on controlled drift. Our study of controlled rough differential equations also relates to work of Mazliak and Nourdin (Stoch Dyn 08:23, 2008).

  6. Stochastic control with rough paths

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, Joscha [University of California San Diego (United States); Friz, Peter K., E-mail: friz@math.tu-berlin.de [TU & WIAS Berlin (Germany); Gassiat, Paul [CEREMADE, Université Paris-Dauphine, PSL Research University (France)

    2017-04-15

    We study a class of controlled differential equations driven by rough paths (or rough path realizations of Brownian motion) in the sense of Lyons. It is shown that the value function satisfies a HJB type equation; we also establish a form of the Pontryagin maximum principle. Deterministic problems of this type arise in the duality theory for controlled diffusion processes and typically involve anticipating stochastic analysis. We make the link to old work of Davis and Burstein (Stoch Stoch Rep 40:203–256, 1992) and then prove a continuous-time generalization of Roger’s duality formula [SIAM J Control Optim 46:1116–1132, 2007]. The generic case of controlled volatility is seen to give trivial duality bounds, and explains the focus in Burstein–Davis’ (and this) work on controlled drift. Our study of controlled rough differential equations also relates to work of Mazliak and Nourdin (Stoch Dyn 08:23, 2008).

  7. Path modeling and process control

    DEFF Research Database (Denmark)

    Høskuldsson, Agnar; Rodionova, O.; Pomerantsev, A.

    2007-01-01

    and having three or more stages. The methods are applied to a process control of a multi-stage production process having 25 variables and one output variable. When moving along the process, variables change their roles. It is shown how the methods of path modeling can be applied to estimate variables...... be performed regarding the foreseeable output property y, and with respect to an admissible range of correcting actions for the parameters of the next stage. In this paper the basic principles of path modeling is presented. The mathematics is presented for processes having only one stage, having two stages...... of the next stage with the purpose of obtaining optimal or almost optimal quality of the output variable. An important aspect of the methods presented is the possibility of extensive graphic analysis of data that can provide the engineer with a detailed view of the multi-variate variation in data....

  8. Factorization-algebraization-path integration

    International Nuclear Information System (INIS)

    Inomata, A.; Wilson, R.

    1986-01-01

    The authors review the method of factorization proposed by Schroedinger of a quantum mechanical second-order linear differential equation into a product of two first-order differential operators, often referred to as ladder operators, as well as the modifications made to Schroedinger's method by Infeld and Hull. They then review the group theoretical treatments proposed by Miller of the Schroedinger-Infeld-Hull factorizations and go on to demonstrate the application of dynamical symmetry to path integral calculations. 30 references

  9. The path of code linting

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    Join the path of code linting and discover how it can help you reach higher levels of programming enlightenment. Today we will cover how to embrace code linters to offload cognitive strain on preserving style standards in your code base as well as avoiding error-prone constructs. Additionally, I will show you the journey ahead for integrating several code linters in the programming tools your already use with very little effort.

  10. Career path for operations personnel

    International Nuclear Information System (INIS)

    Asher, J.A.

    1985-01-01

    This paper explains how selected personnel can now obtain a Bachelor of Science degree in Physics with a Nuclear Power Operations option. The program went into effect the Fall of 1984. Another program was worked out in 1982 whereby students attending the Nuclear Operators Training Program could obtain an Associates of Science degree in Mechanical Engineering Technology at the end of two years of study. This paper presents tables and charts which describe these programs and outline the career path for operators

  11. Conditionally solvable path integral problems

    International Nuclear Information System (INIS)

    Grosche, C.

    1995-05-01

    Some specific conditionally exactly solvable potentials are discussed within the path integral formalism. They generalize the usually known potentials by the incorporation of a fractional power behaviour and strongly anharmonic terms. We find four different kinds of such potentials, the first is related to the Coulomb potential, the second is an anharmonic confinement potential, and the third and the fourth are related to the Manning-Rosen potential. (orig.)

  12. Path integrals in curvilinear coordinates

    International Nuclear Information System (INIS)

    Prokhorov, L.V.

    1984-01-01

    Integration limits are studied for presenting the path integral curvilinear coordinates. For spherical (and topoloqically equivalent) coordinates it is shown that in formulas involving classical action in the exponent integration over all variables should be carried out within infinite limits. Another peculiarity is associated with appearance of the operator q which provides a complete definition of the wave functions out of the physical region. arguments are given upporting the validity of the cited statament in the general case

  13. Remote sensing for industrial applications in the energy business: digital territorial data integration for planning of overhead power transmission lines (OHTLs)

    Science.gov (United States)

    Terrazzino, Alfonso; Volponi, Silvia; Borgogno Mondino, Enrico

    2001-12-01

    An investigation has been carried out, concerning remote sensing techniques, in order to assess their potential application to the energy system business: the most interesting results concern a new approach, based on digital data from remote sensing, to infrastructures with a large territorial distribution: in particular OverHead Transmission Lines, for the high voltage transmission and distribution of electricity on large distances. Remote sensing could in principle be applied to all the phases of the system lifetime, from planning to design, to construction, management, monitoring and maintenance. In this article, a remote sensing based approach is presented, targeted to the line planning: optimization of OHTLs path and layout, according to different parameters (technical, environmental and industrial). Planning new OHTLs is of particular interest in emerging markets, where typically the cartography is missing or available only on low accuracy scale (1:50.000 and lower), often not updated. Multi- spectral images can be used to generate thematic maps of the region of interest for the planning (soil coverage). Digital Elevation Models (DEMs), allow the planners to easily access the morphologic information of the surface. Other auxiliary information from local laws, environmental instances, international (IEC) standards can be integrated in order to perform an accurate optimized path choice and preliminary spotting of the OHTLs. This operation is carried out by an ABB proprietary optimization algorithm: the output is a preliminary path that bests fits the optimization parameters of the line in a life cycle approach.

  14. Construction of Optimal-Path Maps for Homogeneous-Cost-Region Path-Planning Problems

    Science.gov (United States)

    1989-09-01

    of Artificial Inteligence , 9%,4. 24. Kirkpatrick, S., Gelatt Jr., C. D., and Vecchi, M. P., "Optinization by Sinmulated Ani- nealing", Science, Vol...studied in depth by researchers in such fields as artificial intelligence, robot;cs, and computa- tional geometry. Most methods require homogeneous...the results of the research. 10 U. L SLEVANT RESEARCH A. APPLICABLE CONCEPTS FROM ARTIFICIAL INTELLIGENCE 1. Search Methods One of the central

  15. CDMA coverage under mobile heterogeneous network load

    NARCIS (Netherlands)

    Saban, D.; van den Berg, Hans Leo; Boucherie, Richardus J.; Endrayanto, A.I.

    2002-01-01

    We analytically investigate coverage (determined by the uplink) under non-homogeneous and moving traffic load of third generation UMTS mobile networks. In particular, for different call assignment policies, we investigate cell breathing and the movement of the coverage gap occurring between cells

  16. 5 CFR 531.402 - Employee coverage.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Employee coverage. 531.402 Section 531... GENERAL SCHEDULE Within-Grade Increases § 531.402 Employee coverage. (a) Except as provided in paragraph (b) of this section, this subpart applies to employees who— (1) Are classified and paid under the...

  17. 22 CFR 226.31 - Insurance coverage.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Insurance coverage. 226.31 Section 226.31 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ADMINISTRATION OF ASSISTANCE AWARDS TO U.S. NON-GOVERNMENTAL ORGANIZATIONS Post-award Requirements Property Standards § 226.31 Insurance coverage. Recipients...

  18. 14 CFR 1260.131 - Insurance coverage.

    Science.gov (United States)

    2010-01-01

    ... coverage. Recipients shall, at a minimum, provide the equivalent insurance coverage for real property and equipment acquired with Federal funds as provided for property owned by the recipient. Federally-owned property need not be insured unless required by the terms and conditions of the award. ...

  19. 2 CFR 215.31 - Insurance coverage.

    Science.gov (United States)

    2010-01-01

    ... Insurance coverage. Recipients shall, at a minimum, provide the equivalent insurance coverage for real property and equipment acquired with Federal funds as provided to property owned by the recipient. Federally-owned property need not be insured unless required by the terms and conditions of the award. ...

  20. 36 CFR 1210.31 - Insurance coverage.

    Science.gov (United States)

    2010-07-01

    ....31 Insurance coverage. Recipients shall, at a minimum, provide the equivalent insurance coverage for real property and equipment acquired with NHPRC funds as provided to property owned by the recipient. Federally-owned property need not be insured unless required by the terms and conditions of the award. ...

  1. Coverage matters: insurance and health care

    National Research Council Canada - National Science Library

    Board on Health Care Services Staff; Institute of Medicine Staff; Institute of Medicine; National Academy of Sciences

    2001-01-01

    ...? How does the system of insurance coverage in the U.S. operate, and where does it fail? The first of six Institute of Medicine reports that will examine in detail the consequences of having a large uninsured population, Coverage Matters...

  2. Legislating health care coverage for the unemployed.

    Science.gov (United States)

    Palley, H A; Feldman, G; Gallner, I; Tysor, M

    1985-01-01

    Because the unemployed and their families are often likely to develop stress-related health problems, ensuring them access to health care is a public health issue. Congressional efforts thus far to legislate health coverage for the unemployed have proposed a system that recognizes people's basic need for coverage but has several limitations.

  3. Polygonal-path approximations on the path spaces of quantum-mechanical systems: properties of the polygonal paths

    International Nuclear Information System (INIS)

    Exner, P.; Kolerov, G.I.

    1981-01-01

    Properties of the subset of polygonal paths in the Hilbert space H of paths referring to a d-dimensional quantum-mechanical system are examined. Using the reproduction kernel technique we prove that each element of H is approximated by polygonal paths uniformly with respect to the ''norm'' of time-interval partitions. This result will be applied in the second part of the present paper to prove consistency of the uniform polygonal-path extension of the Feynman maps [ru

  4. Path Integrals in Quantum Mechanics

    International Nuclear Information System (INIS)

    Chetouani, L

    2005-01-01

    By treating path integrals the author, in this book, places at the disposal of the reader a modern tool for the comprehension of standard quantum mechanics. Thus the most important applications, such as the tunnel effect, the diffusion matrix, etc, are presented from an original point of view on the action S of classical mechanics while having it play a central role in quantum mechanics. What also emerges is that the path integral describes these applications more richly than are described traditionally by differential equations, and consequently explains them more fully. The book is certainly of high quality in all aspects: original in presentation, rigorous in the demonstrations, judicious in the choice of exercises and, finally, modern, for example in the treatment of the tunnel effect by the method of instantons. Moreover, the correspondence that exists between classical and quantum mechanics is well underlined. I thus highly recommend this book (the French version being already available) to those who wish to familiarize themselves with formulation by path integrals. They will find, in addition, interesting topics suitable for exploring further. (book review)

  5. Nonperturbative path integral expansion II

    International Nuclear Information System (INIS)

    Kaiser, H.J.

    1976-05-01

    The Feynman path integral representation of the 2-point function for a self-interacting Bose field is investigated using an expansion ('Path Integral Expansion', PIE) of the exponential of the kinetic term of the Lagrangian. This leads to a series - illustrated by a graph scheme - involving successively a coupling of more and more points of the lattice space commonly employed in the evaluation of path integrals. The values of the individual PIE graphs depend of course on the lattice constant. Two methods - Pade approximation and Borel-type extrapolation - are proposed to extract information about the continuum limit from a finite-order PIE. A more flexible PIE is possible by expanding besides the kinetic term a suitably chosen part of the interaction term too. In particular, if the co-expanded part is a mass term the calculation becomes only slightly more complicated than in the original formulation and the appearance of the graph scheme is unchanged. A significant reduction of the number of graphs and an improvement of the convergence of the PIE can be achieved by performing certain sums over an infinity of graph elements. (author)

  6. Distribution definition of path integrals

    International Nuclear Information System (INIS)

    Kerler, W.

    1979-01-01

    By starting from quantum mechanics it turns out that a rather general definition of quantum functional integrals can be given which is based on distribution theory. It applies also to curved space and provides clear rules for non-linear transformations. The refinements necessary in usual definitions of path integrals are pointed out. Since the quantum nature requires special care with time sequences, it is not the classical phase space which occurs in the phase-space form of the path integral. Feynman's configuration-space form only applies to a highly specialized situation, and therefore is not a very advantageous starting point for general investigations. It is shown that the commonly used substitutions of variables do not properly account for quantum effects. The relation to the traditional ordering problem is clarified. The distribution formulation has allowed to treat constrained systems directly at the quantum level, to complete the path integral formulation of the equivalence theorem, and to define functional integrals also for space translation after the transition to fields. (orig.)

  7. Comparative analysis of individuals with and without chiropractic coverage: patient characteristics, utilization, and costs.

    Science.gov (United States)

    Legorreta, Antonio P; Metz, R Douglas; Nelson, Craig F; Ray, Saurabh; Chernicoff, Helen Oster; Dinubile, Nicholas A

    2004-10-11

    Back pain accounts for more than $100 billion in annual US health care costs and is the second leading cause of physician visits and hospitalizations. This study ascertains the effect of systematic access to chiropractic care on the overall and neuromusculoskeletal-specific consumption of health care resources within a large managed-care system. A 4-year retrospective claims data analysis comparing more than 700 000 health plan members with an additional chiropractic coverage benefit and 1 million members of the same health plan without the chiropractic benefit. Members with chiropractic insurance coverage, compared with those without coverage, had lower annual total health care expenditures ($1463 vs $1671 per member per year, P<.001). Having chiropractic coverage was associated with a 1.6% decrease (P = .001) in total annual health care costs at the health plan level. Back pain patients with chiropractic coverage, compared with those without coverage, had lower utilization (per 1000 episodes) of plain radiographs (17.5 vs 22.7, P<.001), low back surgery (3.3 vs 4.8, P<.001), hospitalizations (9.3 vs 15.6, P<.001), and magnetic resonance imaging (43.2 vs 68.9, P<.001). Patients with chiropractic coverage, compared with those without coverage, also had lower average back pain episode-related costs ($289 vs $399, P<.001). Access to managed chiropractic care may reduce overall health care expenditures through several effects, including (1) positive risk selection; (2) substitution of chiropractic for traditional medical care, particularly for spine conditions; (3) more conservative, less invasive treatment profiles; and (4) lower health service costs associated with managed chiropractic care. Systematic access to managed chiropractic care not only may prove to be clinically beneficial but also may reduce overall health care costs.

  8. Surface diffusion and coverage effect of Li atom on graphene as studied by several density functional theory methods

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Zhi [Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, 62210 Cuernavaca, Morelos (Mexico); Contreras-Torres, Flavio F., E-mail: flavioc@nucleares.unam.mx [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, 04510 México, DF (Mexico); Jalbout, Abraham F.; Ramírez-Treviño, Alberto [Instituto Tecnológico de Estudios Superiores de Cajeme, Ciudad Obregon, Sonora (Mexico)

    2013-11-15

    The adsorption of Li atom on graphene is examined using density functional theory methods. Three different adsorption sites are considered, including the on top of a carbon atom (OT), on top of a C-C bond (Bri), and on top of a hexagon (Hol), as well as Li adsorbed at different coverage. The Hol site is found to be the most stable, followed by the Bri and OT sites. The order of stabilization is independent of coverage. The localization of Li–graphene interaction at all sites has reverse order with stabilization. The localization will cause different repulsive interaction between Li atoms which is believed to take responsibility for the difference between the charge transfer order and adsorption energy order of Li adsorption at all possible sites. Repulsive interaction also causes the decreasing of adsorption energies of Li at Hol site with increasing coverage, but the corresponding influence is bigger at low coverage range (0.020–0.056 monolayers) than that at high coverage range (0.056–0.250 monolayers). The trend of charge transfer and dipole moment with increasing coverage is also in agreement with that of adsorption energy. It is also found that the distance of Li above graphene will increase with increasing coverage, but a so-called “zigzag” curve appears, which exhibits an oscillatory behavior as a function of increasing coverage. The diffusion of Li atom on graphene is also studied. Li atom migrates from a Hol site to a neighboring Hol site through the Bri site between them is found to be the minimum energy path. Within the studied coverage range, the diffusion barrier decreases with increasing coverage which can be ascribed to the phenomenon of different repulsion interactions when Li atom adsorbs at different sites. The increasing coverage amplified the phenomenon.

  9. Electron Inelastic-Mean-Free-Path Database

    Science.gov (United States)

    SRD 71 NIST Electron Inelastic-Mean-Free-Path Database (PC database, no charge)   This database provides values of electron inelastic mean free paths (IMFPs) for use in quantitative surface analyses by AES and XPS.

  10. Time optimal paths for high speed maneuvering

    Energy Technology Data Exchange (ETDEWEB)

    Reister, D.B.; Lenhart, S.M.

    1993-01-01

    Recent theoretical results have completely solved the problem of determining the minimum length path for a vehicle with a minimum turning radius moving from an initial configuration to a final configuration. Time optimal paths for a constant speed vehicle are a subset of the minimum length paths. This paper uses the Pontryagin maximum principle to find time optimal paths for a constant speed vehicle. The time optimal paths consist of sequences of axes of circles and straight lines. The maximum principle introduces concepts (dual variables, bang-bang solutions, singular solutions, and transversality conditions) that provide important insight into the nature of the time optimal paths. We explore the properties of the optimal paths and present some experimental results for a mobile robot following an optimal path.

  11. Classical and quantum dynamics from classical paths to path integrals

    CERN Document Server

    Dittrich, Walter

    2016-01-01

    Graduate students who want to become familiar with advanced computational strategies in classical and quantum dynamics will find here both the fundamentals of a standard course and a detailed treatment of the time-dependent oscillator, Chern-Simons mechanics, the Maslov anomaly and the Berry phase, to name a few. Well-chosen and detailed examples illustrate the perturbation theory, canonical transformations, the action principle and demonstrate the usage of path integrals. This new edition has been revised and enlarged with chapters on quantum electrodynamics, high energy physics, Green’s functions and strong interaction.

  12. Path Integral Formulation of Anomalous Diffusion Processes

    OpenAIRE

    Friedrich, Rudolf; Eule, Stephan

    2011-01-01

    We present the path integral formulation of a broad class of generalized diffusion processes. Employing the path integral we derive exact expressions for the path probability densities and joint probability distributions for the class of processes under consideration. We show that Continuous Time Random Walks (CTRWs) are included in our framework. A closed expression for the path probability distribution of CTRWs is found in terms of their waiting time distribution as the solution of a Dyson ...

  13. Expanding insurance coverage through tax credits, consumer choice, and market enhancements: the American Medical Association proposal for health insurance reform.

    Science.gov (United States)

    Palmisano, Donald J; Emmons, David W; Wozniak, Gregory D

    2004-05-12

    Recent reports showing an increase in the number of uninsured individuals in the United States have given heightened attention to increasing health insurance coverage. The American Medical Association (AMA) has proposed a system of tax credits for the purchase of individually owned health insurance and enhancements to individual and group health insurance markets as a means of expanding coverage. Individually owned insurance would enable people to maintain coverage without disruption to existing patient-physician relationships, regardless of changes in employers or in work status. The AMA's plan would empower individuals to choose their health plan and give patients and their physicians more control over health care choices. Employers could continue to offer employment-based coverage, but employees would not be limited to the health plans offered by their employer. With a tax credit large enough to make coverage affordable and the ability to choose their own coverage, consumers would dramatically transform the individual and group health insurance markets. Health insurers would respond to the demands of individual consumers and be more cautious about increasing premiums. Insurers would also tailor benefit packages and develop new forms of coverage to better match the preferences of individuals and families. The AMA supports the development of new health insurance markets through legislative and regulatory changes to foster a wider array of high-quality, affordable plans.

  14. Education - path towards solution regarding disposal of spent nuclear fuel

    International Nuclear Information System (INIS)

    Klein, D.E.

    1991-01-01

    Education, not emotional reaction, is the path to take in the safe disposal of spent nuclear fuel. Education is needed at all levels: Elementary schools, secondary schools, two-year colleges, four-year colleges, graduate schools, and adult education. The Office of Civilian Radioactive Waste Management (OCRWM) should not be expected to tackle this problem alone. Assistance is needed from local communities, schools, and state and federal governments. However, OCRWM can lay the foundation for a comprehensive educational plan directed specifically at educating the public on the spent nuclear fuel issue and OCRWM can begin the implementation of this plan

  15. Sensitivity of postplanning target and OAR coverage estimates to dosimetric margin distribution sampling parameters.

    Science.gov (United States)

    Xu, Huijun; Gordon, J James; Siebers, Jeffrey V

    2011-02-01

    A dosimetric margin (DM) is the margin in a specified direction between a structure and a specified isodose surface, corresponding to a prescription or tolerance dose. The dosimetric margin distribution (DMD) is the distribution of DMs over all directions. Given a geometric uncertainty model, representing inter- or intrafraction setup uncertainties or internal organ motion, the DMD can be used to calculate coverage Q, which is the probability that a realized target or organ-at-risk (OAR) dose metric D, exceeds the corresponding prescription or tolerance dose. Postplanning coverage evaluation quantifies the percentage of uncertainties for which target and OAR structures meet their intended dose constraints. The goal of the present work is to evaluate coverage probabilities for 28 prostate treatment plans to determine DMD sampling parameters that ensure adequate accuracy for postplanning coverage estimates. Normally distributed interfraction setup uncertainties were applied to 28 plans for localized prostate cancer, with prescribed dose of 79.2 Gy and 10 mm clinical target volume to planning target volume (CTV-to-PTV) margins. Using angular or isotropic sampling techniques, dosimetric margins were determined for the CTV, bladder and rectum, assuming shift invariance of the dose distribution. For angular sampling, DMDs were sampled at fixed angular intervals w (e.g., w = 1 degree, 2 degrees, 5 degrees, 10 degrees, 20 degrees). Isotropic samples were uniformly distributed on the unit sphere resulting in variable angular increments, but were calculated for the same number of sampling directions as angular DMDs, and accordingly characterized by the effective angular increment omega eff. In each direction, the DM was calculated by moving the structure in radial steps of size delta (=0.1, 0.2, 0.5, 1 mm) until the specified isodose was crossed. Coverage estimation accuracy deltaQ was quantified as a function of the sampling parameters omega or omega eff and delta. The

  16. Partial Path Column Generation for the ESPPRC

    DEFF Research Database (Denmark)

    Jepsen, Mads Kehlet; Petersen, Bjørn

    This talk introduces a decomposition of the Elementary Shortest Path Problem with Resource Constraints(ESPPRC), where the path is combined by smaller sub paths. We show computational result by comparing different approaches for the decomposition and compare the best of these with existing algorit...

  17. Strain path dependency in metal plasticity

    NARCIS (Netherlands)

    Viatkina, E.M.; Brekelmans, W.A.M.; Geers, M.G.D.

    2003-01-01

    A change in strain path has a significant effect on the mechanical response of metals. Strain path change effects physically originate from a complex microstructure evolution. This paper deals with the contribution of cell structure evolution to the strain path change effect. The material with cells

  18. Real-time Stitched Video for Contextual Path Planning

    Data.gov (United States)

    National Aeronautics and Space Administration — The crew and flight controllers who control the Space Station Remote Manipulator System (SSRMS) currently rely on multiple camera views to confirm or infer clearance...

  19. Distance estimation by computer vision and shortest path planning ...

    African Journals Online (AJOL)

    pc

    2018-03-22

    Mar 22, 2018 ... static or dynamic obstacle environment [1] [2] [3]. Several sensors as laser sensors, ultrasonic sensors ... decrement in processing time with higher speed. .... [1] A. Kynova, "Indoor Spatial Data Model for Wayfinding: A Case.

  20. Distance estimation by computer vision and shortest path planning ...

    African Journals Online (AJOL)

    Journal Home > Vol 10, No 6S (2018) > ... The proposed way also detects and avoids obstacles in an environment using a single ... This paper has a great importance because of its fast execution speed also vision is a smart sensor as it helps ...

  1. Goal-oriented path planning for ground and aerial vehicles

    OpenAIRE

    Signifredi, Andrea

    2017-01-01

    Nowadays autonomous robots are used in everyday life more than ever. The idea that motivate the develop of new autonomous application is to lessen the fatigue of repetitive works and to make safer the work that are difficult if done by humans alone. Another goal of autonomous robots is to improve precision and repetitiveness in the actuation of actions. Car makers are now showing to consider autonomous driving a ground braking functionality and one of the most important additions to their ass...

  2. Concurrent Path Planning with One or More Humanoid Robots

    Science.gov (United States)

    Sanders, Adam M. (Inventor); Reiland, Matthew J. (Inventor)

    2014-01-01

    A robotic system includes a controller and one or more robots each having a plurality of robotic joints. Each of the robotic joints is independently controllable to thereby execute a cooperative work task having at least one task execution fork, leading to multiple independent subtasks. The controller coordinates motion of the robot(s) during execution of the cooperative work task. The controller groups the robotic joints into task-specific robotic subsystems, and synchronizes motion of different subsystems during execution of the various subtasks of the cooperative work task. A method for executing the cooperative work task using the robotic system includes automatically grouping the robotic joints into task-specific subsystems, and assigning subtasks of the cooperative work task to the subsystems upon reaching a task execution fork. The method further includes coordinating execution of the subtasks after reaching the task execution fork.

  3. Strategy for robot motion and path planning in robot taping

    Science.gov (United States)

    Yuan, Qilong; Chen, I.-Ming; Lembono, Teguh Santoso; Landén, Simon Nelson; Malmgren, Victor

    2016-06-01

    Covering objects with masking tapes is a common process for surface protection in processes like spray painting, plasma spraying, shot peening, etc. Manual taping is tedious and takes a lot of effort of the workers. The taping process is a special process which requires correct surface covering strategy and proper attachment of the masking tape for an efficient surface protection. We have introduced an automatic robot taping system consisting of a robot manipulator, a rotating platform, a 3D scanner and specially designed taping end-effectors. This paper mainly talks about the surface covering strategies for different classes of geometries. The methods and corresponding taping tools are introduced for taping of following classes of surfaces: Cylindrical/extended surfaces, freeform surfaces with no grooves, surfaces with grooves, and rotational symmetrical surfaces. A collision avoidance algorithm is introduced for the robot taping manipulation. With further improvements on segmenting surfaces of taping parts and tape cutting mechanisms, such taping solution with the taping tool and the taping methodology can be combined as a very useful and practical taping package to assist humans in this tedious and time costly work.

  4. Network television news coverage of environmental risks

    International Nuclear Information System (INIS)

    Greenberg, M.R.; Sandman, P.M.; Sachsman, D.V.; Salomone, K.L.

    1989-01-01

    Despite the criticisms that surround television coverage of environmental risk, there have been relatively few attempts to measure what and whom television shows. Most research has focused analysis on a few weeks of coverage of major stories like the gas leak at Bhopal, the Three Mile Island nuclear accident, or the Mount St. Helen's eruption. To advance the research into television coverage of environmental risk, an analysis has been made of all environmental risk coverage by the network nightly news broadcasts for a period of more than two years. Researchers have analyzed all environmental risk coverage-564 stories in 26 months-presented on ABC, CBS, and NBC's evening news broadcasts from January 1984 through February 1986. The quantitative information from the 564 stories was balanced by a more qualitative analysis of the television coverage of two case studies-the dioxin contamination in Times Beach, Missouri, and the suspected methyl isocyanate emissions from the Union Carbide plant in Institute, West Virginia. Both qualitative and quantitative data contributed to the analysis of the role played by experts and environmental advocacy sources in coverage of environmental risk and to the suggestions for increasing that role

  5. Insurance Coverage Policies for Personalized Medicine

    Directory of Open Access Journals (Sweden)

    Andrew Hresko

    2012-10-01

    Full Text Available Adoption of personalized medicine in practice has been slow, in part due to the lack of evidence of clinical benefit provided by these technologies. Coverage by insurers is a critical step in achieving widespread adoption of personalized medicine. Insurers consider a variety of factors when formulating medical coverage policies for personalized medicine, including the overall strength of evidence for a test, availability of clinical guidelines and health technology assessments by independent organizations. In this study, we reviewed coverage policies of the largest U.S. insurers for genomic (disease-related and pharmacogenetic (PGx tests to determine the extent that these tests were covered and the evidence basis for the coverage decisions. We identified 41 coverage policies for 49 unique testing: 22 tests for disease diagnosis, prognosis and risk and 27 PGx tests. Fifty percent (or less of the tests reviewed were covered by insurers. Lack of evidence of clinical utility appears to be a major factor in decisions of non-coverage. The inclusion of PGx information in drug package inserts appears to be a common theme of PGx tests that are covered. This analysis highlights the variability of coverage determinations and factors considered, suggesting that the adoption of personal medicine will affected by numerous factors, but will continue to be slowed due to lack of demonstrated clinical benefit.

  6. Space charge models and PATH

    International Nuclear Information System (INIS)

    Wald, H.B.

    1990-01-01

    The 'PATH' codes are used to design magnetic optics subsystems for neutral particle beam systems. They include a 2-1/2D and three 3-D space charge models, two of which have recently been added. This paper describes the 3-D models and reports on preliminary benchmark studies in which these models are checked for stability as the cloud size is varied and for consistency with each other. Differences between the models are investigated and the computer time requirements for running these models are established

  7. Innovation paths in wind power

    DEFF Research Database (Denmark)

    Lema, Rasmus; Nordensvärd, Johan; Urban, Frauke

    Denmark and Germany both make substantial investments in low carbon innovation, not least in the wind power sector. These investments in wind energy are driven by the twin objectives of reducing carbon emissions and building up international competitive advantage. Support for wind power dates back....... The ‘Danish Design’ remains the global standard. The direct drive design, while uncommon in Denmark, dominates the German installation base. Direct drive technology has thus emerged as a distinctly German design and sub-trajectory within the overall technological innovation path. When it comes to organising...... global interconnectedness of wind technology markets and the role of emerging new players, such as China and India....

  8. Uncommon paths in quantum physics

    CERN Document Server

    Kazakov, Konstantin V

    2014-01-01

    Quantum mechanics is one of the most fascinating, and at the same time most controversial, branches of contemporary science. Disputes have accompanied this science since its birth and have not ceased to this day. Uncommon Paths in Quantum Physics allows the reader to contemplate deeply some ideas and methods that are seldom met in the contemporary literature. Instead of widespread recipes of mathematical physics, based on the solutions of integro-differential equations, the book follows logical and partly intuitional derivations of non-commutative algebra. Readers can directly penetrate the

  9. Air Pollution alongside Bike-Paths in Bogota - Colombia

    Directory of Open Access Journals (Sweden)

    Juan Felipe Franco

    2016-11-01

    Full Text Available The study we present in this paper aims at characterizing the range of fine particulate matter (PM2.5 and black carbon (BC concentrations to which bike-path users in Bogotá are exposed to. Using a bike equipped with a DustTrak and a micro-aethalometer we measured PM2.5 and BC concentration levels along bike-paths corridors, during weekdays and weekends. Experiments were conducted in fours streets, representing four typical configurations of bike-paths in the city. Traffic data for workdays was also available from local mobility authority. Results indicate that bike-paths users in Bogota are exposed to air pollution levels far exceeding the threshold values established as potentially dangerous for human health. Average concentrations for PM2.5 ranged between 80 and 136 ug/m3 in workdays and between 30 and 72 ug/m3 in weekends. BC mean concentrations were between 16 and 38 µg/m3 during workdays and in the range 10 to 32 µg/m3 during weekends. A statistically significant difference exists in the levels of pollutants concentrations measured during workdays and weekends for all the considered bike paths. According to our results, both traffic volume and diffusions conditions, which are affected by many factors including street geometry, affect bike-path user’s exposure levels. Taking into account the important role that bicycling is playing as an alternative transport mode in Latin American cities, we consider these results provide useful insights to increase the appreciation of the excessive bikers´ exposure to air pollution in Bogotá. Moreover, these findings contribute with technical elements that should lead to the inclusion of air quality variable when designing and planning sustainable urban mobility infrastructures.

  10. The Waypoint Planning Tool: Real Time Flight Planning for Airborne Science

    Science.gov (United States)

    He, M.; Goodman, H. M.; Blakeslee, R.; Hall, J. M.

    2010-12-01

    NASA Earth science research utilizes both spaceborne and airborne real time observations in the planning and operations of its field campaigns. The coordination of air and space components is critical to achieve the goals and objectives and ensure the success of an experiment. Spaceborne imagery provides regular and continual coverage of the Earth and it is a significant component in all NASA field experiments. Real time visible and infrared geostationary images from GOES satellites and multi-spectral data from the many elements of the NASA suite of instruments aboard the TRMM, Terra, Aqua, Aura, and other NASA satellites have become norm. Similarly, the NASA Airborne Science Program draws upon a rich pool of instrumented aircraft. The NASA McDonnell Douglas DC-8, Lockheed P3 Orion, DeHavilland Twin Otter, King Air B200, Gulfstream-III are all staples of a NASA’s well-stocked, versatile hangar. A key component in many field campaigns is coordinating the aircraft with satellite overpasses, other airplanes and the constantly evolving, dynamic weather conditions. Given the variables involved, developing a good flight plan that meets the objectives of the field experiment can be a challenging and time consuming task. Planning a research aircraft mission within the context of meeting the science objectives is complex task because it is much more than flying from point A to B. Flight plans typically consist of flying a series of transects or involve dynamic path changes when “chasing” a hurricane or forest fire. These aircraft flight plans are typically designed by the mission scientists then verified and implemented by the navigator or pilot. Flight planning can be an arduous task requiring frequent sanity checks by the flight crew. This requires real time situational awareness of the weather conditions that affect the aircraft track. Scientists at the University of Alabama-Huntsville and the NASA Marshall Space Flight Center developed the Waypoint Planning Tool

  11. Sky coverage modeling for the whole sky for laser guide star multiconjugate adaptive optics.

    Science.gov (United States)

    Wang, Lianqi; Andersen, David; Ellerbroek, Brent

    2012-06-01

    The scientific productivity of laser guide star adaptive optics systems strongly depends on the sky coverage, which describes the probability of finding natural guide stars for the tip/tilt wavefront sensor(s) to achieve a certain performance. Knowledge of the sky coverage is also important for astronomers planning their observations. In this paper, we present an efficient method to compute the sky coverage for the laser guide star multiconjugate adaptive optics system, the Narrow Field Infrared Adaptive Optics System (NFIRAOS), being designed for the Thirty Meter Telescope project. We show that NFIRAOS can achieve more than 70% sky coverage over most of the accessible sky with the requirement of 191 nm total rms wavefront.

  12. [Using the concept of universal health coverage to promote the health system reform in China].

    Science.gov (United States)

    Hu, S L

    2016-11-06

    The paper is systematically explained the definition, contents of universal health coverage (UHC). Universal health coverage calls for all people to have access to quality health services they need without facing undue financial burden. The relationship between five main attributes, i.e., quality, efficiency, equity, accountability and resilience, and their 15 action plans has been explained. The nature of UHC is belonged to the State and government. The core function is commitment with equality. The whole-of-system method is used to promoting the health system reform. In China, the universal health coverage has been reached to the preliminary achievements, which include universal coverage of social medical insurance, basic medical services, basic public health services, and the provision of essential medicines. China has completed millennium development goals (MDG) and is being stepped to the sustainable development goals (SDG).

  13. SU-C-19A-07: Influence of Immobilization On Plan Robustness in the Treatment of Head and Neck Cancer with IMPT

    International Nuclear Information System (INIS)

    Bues, M; Anand, A; Liu, W; Shen, J; Keole, S; Patel, S; Morse, B; Kruse, J

    2014-01-01

    Purpose: We evaluated the effect of interposing immobilization devices into the beam's path on the robustness of a head and neck plan. Methods: An anthropomorphic head phantom was placed into a preliminary prototype of a specialized head and neck immobilization device for proton beam therapy. The device consists of a hard low density shell, a custom mold insert, and thermoplastic mask to immobilize the patient's head in the shell. This device was provided by CIVCO Medical Solutions for the purpose of evaluation of suitability for proton beam therapy. See Figure 1. Two pairs of treatment plans were generated. The first plan in each pair was a reference plan including only the anthropomorphic phantom, and the second plan in each pair included the immobilization device. In all other respects the plans within the pair were identical. Results: In the case of the simple plan the degradation of plan robustness was found to be clinically insignificant. In this case, target coverage in the worst case scenario was reduced from 95% of the target volume receiving 96.5% of prescription dose to 95% of the target volume receiving 96.3% of prescription dose by introducing the immobilization device. In the case of the complex plan, target coverage of the boost volume in the worst case scenario was reduced from 95% of the boost target volume receiving 97% of prescription dose to 95% of the boost target volume receiving 83% of prescription dose by introducing the immobilization device. See Figure 2. Conclusion: Immobilization devices may have a deleterious effect on plan robustness. Evaluation of the preliminary prototype revealed a variable impact on the plan robustness depending of the complexity of the case. Brian Morse is an employee of CIVCO Medical Solutions

  14. Trends in US newspaper and television coverage of tobacco.

    Science.gov (United States)

    Nelson, David E; Pederson, Linda L; Mowery, Paul; Bailey, Sarah; Sevilimedu, Varadan; London, Joel; Babb, Stephen; Pechacek, Terry

    2015-01-01

    The news media plays an important role in agenda setting and framing of stories about tobacco control. The purpose of this study was to examine newspaper, newswire and television coverage of tobacco issues in the USA over a 7-year period. Analyses of 2004-2010 news media surveillance system data from the US Centers for Disease Control and Prevention's Office on Smoking and Health, based on content analysis and quantitative methods. Information on extent of news coverage, and types of tobacco-related themes, were examined from articles in 10 newspapers and 2 major newswires, as well as transcripts from 6 national television networks. The overall extent of newspaper, newswire and television stories about tobacco, and level of coverage by specific media outlets, varied over time, especially for newspapers. Nevertheless, there was an average of 3 newspaper stories, 4 newswire stories, and 1 television tobacco-related story each day. Television stories were more likely to contain cessation/addiction or health effects/statistics themes and less likely to contain secondhand smoke or policy/regulation themes than newspaper/newswire stories. There was more variation in the choice of tobacco theme among individual newspapers/newswires than television media outlets. News coverage of tobacco in the USA was relatively constant from 2004 to 2010. Audiences were more likely to be exposed to different tobacco themes in newspapers/newswires than on television. Tracking information about tobacco news stories can be used by advocates, programs and others for planning and evaluation, and by researchers for hypothesis generation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  15. Internet plan and planning

    Directory of Open Access Journals (Sweden)

    Kahriman Emina

    2008-01-01

    Full Text Available Paper discuss specific features of internet plan as well as planning as management process in general in the contemporary environment. No need to stress out that marketing plan and marketing planning is core activity in approaching to market. At the same time, there are a lot specific c request in preparing marketing plan comparing to business planning due to marketing plan is an essential part. The importance of internet plan and planning rely on specific features of the internet network but as a part of general corporate as well as marketing strategy.

  16. NOAA Weather Radio - County Coverage by State

    Science.gov (United States)

    Non-Zero All Hazards Logo Emergency Alert Description Event Codes Fact Sheet FAQ Organization Search Coverage Listings NWR Station Search Maps SAME SAME Coding Using SAME SAME Non-Zero Codes DOCUMENTS NWR

  17. Media Coverage of Nuclear Energy after Fukushima

    International Nuclear Information System (INIS)

    Oltra, C.; Roman, P.; Prades, A.

    2013-01-01

    This report presents the main findings of a content analysis of printed media coverage of nuclear energy in Spain before and after the Fukushima accident. Our main objective is to understand the changes in the presentation of nuclear fission and nuclear fusion as a result of the accident in Japan. We specifically analyze the volume of coverage and thematic content in the media coverage for nuclear fusion from a sample of Spanish print articles in more than 20 newspapers from 2008 to 2012. We also analyze the media coverage of nuclear energy (fission) in three main Spanish newspapers one year before and one year after the accident. The results illustrate how the media contributed to the presentation of nuclear power in the months before and after the accident. This could have implications for the public understanding of nuclear power. (Author)

  18. Media Coverage of Nuclear Energy after Fukushima

    Energy Technology Data Exchange (ETDEWEB)

    Oltra, C.; Roman, P.; Prades, A.

    2013-07-01

    This report presents the main findings of a content analysis of printed media coverage of nuclear energy in Spain before and after the Fukushima accident. Our main objective is to understand the changes in the presentation of nuclear fission and nuclear fusion as a result of the accident in Japan. We specifically analyze the volume of coverage and thematic content in the media coverage for nuclear fusion from a sample of Spanish print articles in more than 20 newspapers from 2008 to 2012. We also analyze the media coverage of nuclear energy (fission) in three main Spanish newspapers one year before and one year after the accident. The results illustrate how the media contributed to the presentation of nuclear power in the months before and after the accident. This could have implications for the public understanding of nuclear power. (Author)

  19. 22 CFR 518.31 - Insurance coverage.

    Science.gov (United States)

    2010-04-01

    ... property owned by the recipient. Federally-owned property need not be insured unless required by the terms... Requirements Property Standards § 518.31 Insurance coverage. Recipients shall, at a minimum, provide the...

  20. 7 CFR 3019.31 - Insurance coverage.

    Science.gov (United States)

    2010-01-01

    ... recipient. Federally-owned property need not be insured unless required by the terms and conditions of the... Standards § 3019.31 Insurance coverage. Recipients shall, at a minimum, provide the equivalent insurance...

  1. 34 CFR 74.31 - Insurance coverage.

    Science.gov (United States)

    2010-07-01

    ... by the recipient. Federally-owned property need not be insured unless required by the terms and... Property Standards § 74.31 Insurance coverage. Recipients shall, at a minimum, provide the equivalent...

  2. 49 CFR 19.31 - Insurance coverage.

    Science.gov (United States)

    2010-10-01

    ... property owned by the recipient. Federally-owned property need not be insured unless required by the terms... Requirements Property Standards § 19.31 Insurance coverage. Recipients shall, at a minimum, provide the...

  3. 10 CFR 600.131 - Insurance coverage.

    Science.gov (United States)

    2010-01-01

    ... provided to property owned by the recipient. Federally-owned property need not be insured unless required... Nonprofit Organizations Post-Award Requirements § 600.131 Insurance coverage. Recipients shall, at a minimum...

  4. 20 CFR 435.31 - Insurance coverage.

    Science.gov (United States)

    2010-04-01

    ... funds as provided to property owned by the recipient. Federally-owned property need not be insured... ORGANIZATIONS Post-Award Requirements Property Standards § 435.31 Insurance coverage. Recipients must, at a...

  5. 28 CFR 70.31 - Insurance coverage.

    Science.gov (United States)

    2010-07-01

    ... with Federal funds as provided to property owned by the recipient. Federally-owned property need not be...-PROFIT ORGANIZATIONS Post-Award Requirements Property Standards § 70.31 Insurance coverage. Recipients...

  6. Coverage for SCS Pre-1941 Aerial Photography

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This shapefile was generated by the U.S. Bureau of Land Management (BLM) at the New Mexico State Office to show the coverage for the Pre-1941 aerial photography...

  7. Integral transforms of the quantum mechanical path integral: Hit function and path-averaged potential

    Science.gov (United States)

    Edwards, James P.; Gerber, Urs; Schubert, Christian; Trejo, Maria Anabel; Weber, Axel

    2018-04-01

    We introduce two integral transforms of the quantum mechanical transition kernel that represent physical information about the path integral. These transforms can be interpreted as probability distributions on particle trajectories measuring respectively the relative contribution to the path integral from paths crossing a given spatial point (the hit function) and the likelihood of values of the line integral of the potential along a path in the ensemble (the path-averaged potential).

  8. Classical and quantum dynamics from classical paths to path integrals

    CERN Document Server

    Dittrich, Walter

    2017-01-01

    Graduate students who wish to become familiar with advanced computational strategies in classical and quantum dynamics will find in this book both the fundamentals of a standard course and a detailed treatment of the time-dependent oscillator, Chern-Simons mechanics, the Maslov anomaly and the Berry phase, to name just a few topics. Well-chosen and detailed examples illustrate perturbation theory, canonical transformations and the action principle, and demonstrate the usage of path integrals. The fifth edition has been revised and enlarged to include chapters on quantum electrodynamics, in particular, Schwinger’s proper time method and the treatment of classical and quantum mechanics with Lie brackets and pseudocanonical transformations. It is shown that operator quantum electrodynamics can be equivalently described with c-numbers, as demonstrated by calculating the propagation function for an electron in a prescribed classical electromagnetic field.

  9. Length and coverage of inhibitory decision rules

    KAUST Repository

    Alsolami, Fawaz

    2012-01-01

    Authors present algorithms for optimization of inhibitory rules relative to the length and coverage. Inhibitory rules have a relation "attribute ≠ value" on the right-hand side. The considered algorithms are based on extensions of dynamic programming. Paper contains also comparison of length and coverage of inhibitory rules constructed by a greedy algorithm and by the dynamic programming algorithm. © 2012 Springer-Verlag.

  10. Path to Market for Compact Modular Fusion Power Cores

    Science.gov (United States)

    Woodruff, Simon; Baerny, Jennifer K.; Mattor, Nathan; Stoulil, Don; Miller, Ronald; Marston, Theodore

    2012-08-01

    The benefits of an energy source whose reactants are plentiful and whose products are benign is hard to measure, but at no time in history has this energy source been more needed. Nuclear fusion continues to promise to be this energy source. However, the path to market for fusion systems is still regularly a matter for long-term (20 + year) plans. This white paper is intended to stimulate discussion of faster commercialization paths, distilling guidance from investors, utilities, and the wider energy research community (including from ARPA-E). There is great interest in a small modular fusion system that can be developed quickly and inexpensively. A simple model shows how compact modular fusion can produce a low cost development path by optimizing traditional systems that burn deuterium and tritium, operating not only at high magnetic field strength, but also by omitting some components that allow for the core to become more compact and easier to maintain. The dominant hurdles to the development of low cost, practical fusion systems are discussed, primarily in terms of the constraints placed on the cost of development stages in the private sector. The main finding presented here is that the bridge from DOE Office of Science to the energy market can come at the Proof of Principle development stage, providing the concept is sufficiently compact and inexpensive that its development allows for a normal technology commercialization path.

  11. Path Loss Prediction Over the Lunar Surface Utilizing a Modified Longley-Rice Irregular Terrain Model

    Science.gov (United States)

    Foore, Larry; Ida, Nathan

    2007-01-01

    This study introduces the use of a modified Longley-Rice irregular terrain model and digital elevation data representative of an analogue lunar site for the prediction of RF path loss over the lunar surface. The results are validated by theoretical models and past Apollo studies. The model is used to approximate the path loss deviation from theoretical attenuation over a reflecting sphere. Analysis of the simulation results provides statistics on the fade depths for frequencies of interest, and correspondingly a method for determining the maximum range of communications for various coverage confidence intervals. Communication system engineers and mission planners are provided a link margin and path loss policy for communication frequencies of interest.

  12. Pre-Existing Condition Insurance Plan Data

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Affordable Care Act created the new Pre-Existing Condition Insurance Plan (PCIP) program to make health insurance available to Americans denied coverage by...

  13. Cooperative Cloud Service Aware Mobile Internet Coverage Connectivity Guarantee Protocol Based on Sensor Opportunistic Coverage Mechanism

    Directory of Open Access Journals (Sweden)

    Qin Qin

    2015-01-01

    Full Text Available In order to improve the Internet coverage ratio and provide connectivity guarantee, based on sensor opportunistic coverage mechanism and cooperative cloud service, we proposed the coverage connectivity guarantee protocol for mobile Internet. In this scheme, based on the opportunistic covering rules, the network coverage algorithm of high reliability and real-time security was achieved by using the opportunity of sensor nodes and the Internet mobile node. Then, the cloud service business support platform is created based on the Internet application service management capabilities and wireless sensor network communication service capabilities, which is the architecture of the cloud support layer. The cooperative cloud service aware model was proposed. Finally, we proposed the mobile Internet coverage connectivity guarantee protocol. The results of experiments demonstrate that the proposed algorithm has excellent performance, in terms of the security of the Internet and the stability, as well as coverage connectivity ability.

  14. South Africa's universal health coverage reforms in the post-apartheid period.

    Science.gov (United States)

    van den Heever, Alexander Marius

    2016-12-01

    In 2011, the South African government published a Green Paper outlining proposals for a single-payer National Health Insurance arrangement as a means to achieve universal health coverage (UHC), followed by a White Paper in 2015. This follows over two decades of health reform proposals and reforms aimed at deepening UHC. The most recent reform departure aims to address pooling and purchasing weaknesses in the health system by internalising both functions within a single scheme. This contrasts with the post-apartheid period from 1994 to 2008 where pooling weaknesses were to be addressed using pooling schemes, in the form of government subsidies and risk-equalisation arrangements, external to the public and private purchasers. This article reviews both reform paths and attempts to reconcile what may appear to be very different approaches. The scale of the more recent set of proposals requires a very long reform path because in the mid-term (the next 25 years) no single scheme will be able to raise sufficient revenue to provide a universal package for the entire population. In the interim, reforms that maintain and improve existing forms of coverage are required. The earlier reform framework (1994-2008) largely addressed this concern while leaving open the final form of the system. Both reform approaches are therefore compatible: the earlier reforms addressed medium- to long-term coverage concerns, while the more recent define the long-term institutional goal. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Path Creation, Path Dependence and Breaking Away from the Path: Re-Examining the Case of Nokia

    OpenAIRE

    Wang, Jens; Hedman, Jonas; Tuunainen, Virpi Kristiina

    2016-01-01

    The explanation of how and why firms succeed or fail is a recurrent research challenge. This is particularly important in the context of technological innovations. We focus on the role of historical events and decisions in explaining such success and failure. Using a case study of Nokia, we develop and extend a multi-layer path dependence framework. We identify four layers of path dependence: technical, strategic and leadership, organizational, and external collaboration. We show how path dep...

  16. Planning for the future.

    Science.gov (United States)

    Stiewing, Janis

    2002-01-01

    Revising the strategic plan was the beginning of a multiyear initiative that will determine the path of the JRCERT. The key word in the preceding statement is beginning. The strategic plan is an ever-changing document. Although some components, such as the values statements, will stand over time, other components will change as accreditation and educational arenas change. That is the paradox of strategic planning: Remaining true to the vision, values and mission statements requires knowing when to change to keep the JRCERT aligned with the responsive to its communities of interest.

  17. On-Line Path Generation and Tracking for High-Speed Wheeled Autonomous Vehicles

    Science.gov (United States)

    2006-02-17

    On-Line Path Generation and Tracking for High-Speed Wheeled Autonomous Vehicles Report Title ABSTRACT In this work we proposed two semi-analytic...298-102 Enclosure 1 On-Line Path Generation and Tracking for High-Speed Wheeled Autonomous Vehicles by...Specifically, the following problems will be addressed during this project: 2.1 Challenges The problem of trajectory planning for high-speed autonomous vehicles is

  18. Rainbow paths with prescribed ends

    DEFF Research Database (Denmark)

    Alishahi, Meysam; Taherkhani, Ali; Thomassen, Carsten

    2011-01-01

    vertices. We also prove that every connected graph with atleast one edge has a proper k-coloring (for some k) such that every vertex of color i has a neighbor of color i + 1 (mod k). C-5 shows that k may have to be greater than the chromatic number. However, if the graph is connected, infinite and locally...... finite, and has finite chromatic number, then the k-coloring exists for every k >= chi(G). In fact, the k-coloring can be chosen such that every vertex is a starting vertex of an infinite path such that the color increases by 1 (mod k) along each edge. The method is based on the circular chromatic number...... chi(c)(G). In particular, we verify the above conjecture for all connected graphs whose circular chromatic number equals the chromatic number....

  19. Counting paths with Schur transitions

    Energy Technology Data Exchange (ETDEWEB)

    Díaz, Pablo [Department of Physics and Astronomy, University of Lethbridge, Lethbridge, Alberta, T1K 3M4 (Canada); Kemp, Garreth [Department of Physics, University of Johannesburg, P.O. Box 524, Auckland Park 2006 (South Africa); Véliz-Osorio, Alvaro, E-mail: aveliz@gmail.com [Mandelstam Institute for Theoretical Physics, University of the Witwatersrand, WITS 2050, Johannesburg (South Africa); School of Physics and Astronomy, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom)

    2016-10-15

    In this work we explore the structure of the branching graph of the unitary group using Schur transitions. We find that these transitions suggest a new combinatorial expression for counting paths in the branching graph. This formula, which is valid for any rank of the unitary group, reproduces known asymptotic results. We proceed to establish the general validity of this expression by a formal proof. The form of this equation strongly hints towards a quantum generalization. Thus, we introduce a notion of quantum relative dimension and subject it to the appropriate consistency tests. This new quantity finds its natural environment in the context of RCFTs and fractional statistics; where the already established notion of quantum dimension has proven to be of great physical importance.

  20. 45 CFR 148.124 - Certification and disclosure of coverage.

    Science.gov (United States)

    2010-10-01

    ... method of counting creditable coverage, and the requesting entity may identify specific information that... a payroll deduction for health coverage, a health insurance identification card, a certificate of...