WorldWideScience

Sample records for cost path location

  1. Costly location in Hotelling duopoly

    NARCIS (Netherlands)

    Hinloopen, J.; Martin, S.

    2013-01-01

    We introduce a cost of location into Hotelling’s (1929) spatial duopoly. We derive the general conditions on the cost-of-location function under which a pure strategy price-location Nash equilibrium exists. With linear transportation cost and a suitably specified cost of location that rises toward

  2. Costly location in Hotelling duopoly

    NARCIS (Netherlands)

    Hinloopen, J.; Martin, S.

    We introduce a cost of location into Hotelling's (1929) spatial duopoly model. We derive the general conditions on the cost-of-location function under which a pure strategy price-location Nash equilibrium exists. With linear transportation cost and a suitably specified cost of location that rises

  3. Least-cost Paths - Some Methodological Issues

    Directory of Open Access Journals (Sweden)

    Irmela Herzog

    2014-06-01

    Full Text Available This article deals with methodological issues connected with least-cost path (LCP calculations in archaeology. The number of LCP studies in archaeology has increased rapidly during the last couple of years, but not all of the approaches applied are based on an appropriate model and implementation. Many archaeologists rely on standard GIS software with default settings for calculating LCPs and are not aware of possible alternatives and the pitfalls that are described in this article. After briefly introducing the aims and applications of LCP methods in archaeology, LCP algorithms are discussed. The outcome of the LCP calculations depends not only on the algorithm but also on the cost model, which often includes several cost components. The discussion of the cost components has a focus on slope, because nearly all archaeological LCP studies take this cost component into account and because several methodological issues are connected with slope-based cost models. Other possible cost components are: the load of the walker, vegetation cover, wetlands or other soil properties, travelling and transport on water, water as barrier and as attractor, aspect, altitude, and social or cultural cost components. Eventually, advantages and disadvantages of different ways of combining cost components are presented. Based on the methodological issues I conclude that both validation checks and variations of the model are necessary to analyse the reliability of archaeological LCP results.

  4. Prediction of slant path rain attenuation statistics at various locations

    Science.gov (United States)

    Goldhirsh, J.

    1977-01-01

    The paper describes a method for predicting slant path attenuation statistics at arbitrary locations for variable frequencies and path elevation angles. The method involves the use of median reflectivity factor-height profiles measured with radar as well as the use of long-term point rain rate data and assumed or measured drop size distributions. The attenuation coefficient due to cloud liquid water in the presence of rain is also considered. Absolute probability fade distributions are compared for eight cases: Maryland (15 GHz), Texas (30 GHz), Slough, England (19 and 37 GHz), Fayetteville, North Carolina (13 and 18 GHz), and Cambridge, Massachusetts (13 and 18 GHz).

  5. 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.

  6. Effective caching of shortest paths for location-based services

    DEFF Research Database (Denmark)

    Jensen, Christian S.; Thomsen, Jeppe Rishede; Yiu, Man Lung

    2012-01-01

    Web search is ubiquitous in our daily lives. Caching has been extensively used to reduce the computation time of the search engine and reduce the network traffic beyond a proxy server. Another form of web search, known as online shortest path search, is popular due to advances in geo...

  7. 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.

  8. Charting a Path to Location Intelligence for STD Control.

    Science.gov (United States)

    Gerber, Todd M; Du, Ping; Armstrong-Brown, Janelle; McNutt, Louise-Anne; Coles, F Bruce

    2009-01-01

    This article describes the New York State Department of Health's GeoDatabase project, which developed new methods and techniques for designing and building a geocoding and mapping data repository for sexually transmitted disease (STD) control. The GeoDatabase development was supported through the Centers for Disease Control and Prevention's Outcome Assessment through Systems of Integrated Surveillance workgroup. The design and operation of the GeoDatabase relied upon commercial-off-the-shelf tools that other public health programs may also use for disease-control systems. This article provides a blueprint of the structure and software used to build the GeoDatabase and integrate location data from multiple data sources into the everyday activities of STD control programs.

  9. Road networks as collections of minimum cost paths

    Science.gov (United States)

    Wegner, Jan Dirk; Montoya-Zegarra, Javier Alexander; Schindler, Konrad

    2015-10-01

    We present a probabilistic representation of network structures in images. Our target application is the extraction of urban roads from aerial images. Roads appear as thin, elongated, partially curved structures forming a loopy graph, and this complex layout requires a prior that goes beyond standard smoothness and co-occurrence assumptions. In the proposed model the network is represented as a union of 1D paths connecting distant (super-)pixels. A large set of putative candidate paths is constructed in such a way that they include the true network as much as possible, by searching for minimum cost paths in the foreground (road) likelihood. Selecting the optimal subset of candidate paths is posed as MAP inference in a higher-order conditional random field. Each path forms a higher-order clique with a type of clique potential, which attracts the member nodes of cliques with high cumulative road evidence to the foreground label. That formulation induces a robust PN -Potts model, for which a global MAP solution can be found efficiently with graph cuts. Experiments with two road data sets show that the proposed model significantly improves per-pixel accuracies as well as the overall topological network quality with respect to several baselines.

  10. Cost Surface-Derived Least-Cost Paths: A Case Study from Iron Age Orkney

    Directory of Open Access Journals (Sweden)

    Brian Rahn

    2005-12-01

    Full Text Available In recent years, GIS landscape models have begun to move towards more sophisticated techniques for representing the land surface in order to analyse site territories, pathways and travel costs. Many of the major commercial GIS packages now offer the ability to generate anisotropic cost surfaces. In addition, recent papers have proposed methodologies for generating cost surfaces to model social preferences affecting travel (Lee and Stucky 1998; Llobera 2000. In terms of practical applications, however, GIS models of catchment areas and paths between sites continue to be dominated by those constructed on the basis of slope alone. In parallel with this, regional analyses of site location, with few exceptions, have been undertaken either within large land masses, largely ignoring the effects of rivers, lakes and the sea on travel costs and affordances, or within single islands, neglecting travel to other neighbouring islands or the mainland. The reasons for this appear to be twofold: first, there is little information available on travel costs and travel rates using pre-industrial transportation technology, beyond very general statements; second, critical analysis of what constitutes an 'acceptable' travel distance is lacking, especially in situations where both water and land transport are possibilities. This article presents some preliminary results from a research project examining the location and distribution of Middle Iron Age sites (brochs in the landscape of Orkney, Northern Scotland. It employs a terrain model, taking into account differing friction values for land and water surfaces, as well as the nature of the shoreline (cliffs, beaches and how this affects access from land to sea and vice versa. It also attempts to model pathways between sites following three friction models: lowest-energy, lowest-visibility (hidden and highest-visibility (exposed.

  11. 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.

  12. Location-based Mobile Relay Selection and Impact of Inaccurate Path Loss Model Parameters

    DEFF Research Database (Denmark)

    Nielsen, Jimmy Jessen; Madsen, Tatiana Kozlova; Schwefel, Hans-Peter

    2010-01-01

    In this paper we propose a relay selection scheme which uses collected location information together with a path loss model for relay selection, and analyze the performance impact of mobility and different error causes on this scheme. Performance is evaluated in terms of bit error rate...... by simulations. The SNR measurement based relay selection scheme proposed previously is unsuitable for use with fast moving users in e.g. vehicular scenarios due to a large signaling overhead. The proposed location based scheme is shown to work well with fast moving users due to a lower signaling overhead...... in these situations. As the location-based scheme relies on a path loss model to estimate link qualities and select relays, the sensitivity with respect to inaccurate estimates of the unknown path loss model parameters is investigated. The parameter ranges that result in useful performance were found...

  13. The time-varying shortest path problem with fuzzy transit costs and speedup

    Directory of Open Access Journals (Sweden)

    Rezapour Hassan

    2016-08-01

    Full Text Available In this paper, we focus on the time-varying shortest path problem, where the transit costs are fuzzy numbers. Moreover, we consider this problem in which the transit time can be shortened at a fuzzy speedup cost. Speedup may also be a better decision to find the shortest path from a source vertex to a specified vertex.

  14. Sequential Optimization of Paths in Directed Graphs Relative to Different Cost Functions

    KAUST Repository

    Abubeker, Jewahir Ali

    2011-05-14

    This paper is devoted to the consideration of an algorithm for sequential optimization of paths in directed graphs relative to di_erent cost functions. The considered algorithm is based on an extension of dynamic programming which allows to represent the initial set of paths and the set of optimal paths after each application of optimization procedure in the form of a directed acyclic graph.

  15. 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

  16. Sequential Optimization of Paths in Directed Graphs Relative to Different Cost Functions

    KAUST Repository

    Mahayni, Malek A.

    2011-01-01

    developed to solve the optimal paths problem with different kinds of graphs. An algorithm that solves the problem of paths’ optimization in directed graphs relative to different cost functions is described in [1]. It follows an approach extended from

  17. Sequential Optimization of Paths in Directed Graphs Relative to Different Cost Functions

    KAUST Repository

    Abubeker, Jewahir Ali; Chikalov, Igor; Hussain, Shahid; Moshkov, Mikhail

    2011-01-01

    This paper is devoted to the consideration of an algorithm for sequential optimization of paths in directed graphs relative to di_erent cost functions. The considered algorithm is based on an extension of dynamic programming which allows

  18. A cost effective topology migration path towards fibre

    OpenAIRE

    Phillipson, F.

    2013-01-01

    If an operator has as starting position a Full Copper topology in which ADSL or VDSL is offered from the Central Office, the next choice he has to make is to provide Full FttH or use an other topology option, e.g. FttCab, first as intermediate step to provide a next generation service package. In this paper we present a gradual topology migration path from Full Copper via FttCab and Hybrid FttH towards Full FttH. We look at the planning issues of this topology migration and the financial impa...

  19. Routeing of power lines through least-cost path analysis and multicriteria evaluation to minimise environmental impacts

    International Nuclear Information System (INIS)

    Bagli, Stefano; Geneletti, Davide; Orsi, Francesco

    2011-01-01

    Least-cost path analysis (LCPA) allows designers to find the 'cheapest' way to connect two locations within a cost surface, which can be computed by combining multiple criteria, and therefore by accounting for different issues (environmental impact, economic investment, etc.). This procedure can be easily implemented with modern Geographic Information System (GIS) technologies, and consequently it has been widely employed to support planning and design of different types of linear infrastructures, ranging from roads to pipelines. This paper presents an approach based on the integration of multicriteria evaluation (MCE) and LCPA to identify the most suitable route for a 132 kV power line. Criteria such as cost, visibility, population density, and ecosystem naturalness were used for the analysis. Firstly, spatial MCE and LCPA were combined to generate cost surfaces, and to identify alternative paths. Subsequently, MCE was used to compare the alternatives, and rank them according to their overall suitability. Finally, a sensitivity analysis allowed the stability of the results to be tested and the most critical factors of the evaluation to be detected. The study found that small changes in the location of the power line start and end points can result in significantly different paths, and consequently impact levels. This suggested that planners should always consider alternative potential locations of terminals in order to identify the best path. Furthermore, it was shown that the use of different weight scenarios may help making the model adaptable to varying environmental and social contexts. The approach was tested on a real-world case study in north-eastern Italy.

  20. A lower cost development path for heavy ion fusion

    International Nuclear Information System (INIS)

    Hogan, W.J.; Meier, W.R.

    1993-01-01

    If two features of the inertial fusion process are exploited successfully, they can lead to significantly lower costs for demonstrating the feasibility of commercial electric power production from this source of energy. First, fusion capsule ignition and burn physics is independent of reaction chamber size and hydrodynamically-equivalent capsules can be designed to perform at small yield, exactly as they do at large yield. This means that an integrated test of all power plant components and feasibility tests of various reaction chamber concepts can be done at much smaller sizes (about 1--2 m first wall radius) and much lower powers (tens of MWs) than magnetic fusion development facilities such as ITER. Second, the driver, which is the most expensive component of currently conceived IFE development facilities, can be used to support more than one experiment target chamber/reactor (simultaneously and/or sequentially). These two factors lead to lower development facility costs, modular facilities, and the planning flexibility to spread costs over time or do several things in parallel and thus shorten the total time needed for development of Inertial Fusion Energy (IFE). In this paper the authors describe the general feature of a heavy ion fusion development plan that takes advantage of upgradable accelerators and the ability to test chambers and reactor systems at small scale in order to reduce development time and costs

  1. Chemical solution deposition: a path towards low cost coated conductors

    International Nuclear Information System (INIS)

    Obradors, X; Puig, T; Pomar, A; Sandiumenge, F; Pinol, S; Mestres, N; Castano, O; Coll, M; Cavallaro, A; Palau, A; Gazquez, J; Gonzalez, J C; Gutierrez, J; Roma, N; Ricart, S; Moreto, J M; Rossell, M D; Tendeloo, G van

    2004-01-01

    The achievement of low cost deposition techniques for high critical current YBa 2 Cu 3 O 7 coated conductors is one of the major objectives to achieve a widespread use of superconductivity in power applications. Chemical solution deposition techniques are appearing as a very promising methodology to achieve epitaxial oxide thin films at a low cost, so an intense effort is being carried out to develop routes for all chemical coated conductor tapes. In this work recent achievements will be presented towards the goal of combining the deposition of different type of buffer layers on metallic substrates based on metal-organic decomposition with the growth of YBa 2 Cu 3 O 7 layers using the trifluoroacetate route. The influence of processing parameters on the microstructure and superconducting properties will be stressed. High critical currents are demonstrated in 'all chemical' multilayers

  2. Green open location-routing problem considering economic and environmental costs

    Directory of Open Access Journals (Sweden)

    Eliana M. Toro

    2016-12-01

    Full Text Available This paper introduces a new bi-objective vehicle routing problem that integrates the Open Location Routing Problem (OLRP, recently presented in the literature, coupled with the growing need for fuel consumption minimization, named Green OLRP (G-OLRP. Open routing problems (ORP are known to be NP-hard problems, in which vehicles start from the set of existing depots and are not required to return to the starting depot after completing their service. The OLRP is a strategic-level problem involving the selection of one or many depots from a set of candidate locations and the planning of delivery radial routes from the selected depots to a set of customers. The concept of radial paths allows us to use a set of constraints focused on maintaining the radiality condition of the paths, which significantly simplifies the set of constraints associated with the connectivity and capacity requirements and provides a suitable alternative when compared with the elimination problem of sub-tours traditionally addressed in the literature. The emphasis in the paper will be placed on modeling rather than solution methods. The model proposed is formulated as a bi-objective problem, considering the minimization of operational costs and the minimization of environmental effects, and it is solved by using the epsilon constraint technique. The results illustrate that the proposed model is able to generate a set of trade-off solutions leading to interesting conclusions about the relationship between operational costs and environmental impact.

  3. A Decision Processing Algorithm for CDC Location Under Minimum Cost SCM Network

    Science.gov (United States)

    Park, N. K.; Kim, J. Y.; Choi, W. Y.; Tian, Z. M.; Kim, D. J.

    Location of CDC in the matter of network on Supply Chain is becoming on the high concern these days. Present status of methods on CDC has been mainly based on the calculation manually by the spread sheet to achieve the goal of minimum logistics cost. This study is focused on the development of new processing algorithm to overcome the limit of present methods, and examination of the propriety of this algorithm by case study. The algorithm suggested by this study is based on the principle of optimization on the directive GRAPH of SCM model and suggest the algorithm utilizing the traditionally introduced MST, shortest paths finding methods, etc. By the aftermath of this study, it helps to assess suitability of the present on-going SCM network and could be the criterion on the decision-making process for the optimal SCM network building-up for the demand prospect in the future.

  4. 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

  5. A chain-of-states acceleration method for the efficient location of minimum energy paths

    International Nuclear Information System (INIS)

    Hernández, E. R.; Herrero, C. P.; Soler, J. M.

    2015-01-01

    We describe a robust and efficient chain-of-states method for computing Minimum Energy Paths (MEPs) associated to barrier-crossing events in poly-atomic systems, which we call the acceleration method. The path is parametrized in terms of a continuous variable t ∈ [0, 1] that plays the role of time. In contrast to previous chain-of-states algorithms such as the nudged elastic band or string methods, where the positions of the states in the chain are taken as variational parameters in the search for the MEP, our strategy is to formulate the problem in terms of the second derivatives of the coordinates with respect to t, i.e., the state accelerations. We show this to result in a very simple and efficient method for determining the MEP. We describe the application of the method to a series of test cases, including two low-dimensional problems and the Stone-Wales transformation in C 60

  6. Sequential Optimization of Paths in Directed Graphs Relative to Different Cost Functions

    KAUST Repository

    Mahayni, Malek A.

    2011-07-01

    Finding optimal paths in directed graphs is a wide area of research that has received much of attention in theoretical computer science due to its importance in many applications (e.g., computer networks and road maps). Many algorithms have been developed to solve the optimal paths problem with different kinds of graphs. An algorithm that solves the problem of paths’ optimization in directed graphs relative to different cost functions is described in [1]. It follows an approach extended from the dynamic programming approach as it solves the problem sequentially and works on directed graphs with positive weights and no loop edges. The aim of this thesis is to implement and evaluate that algorithm to find the optimal paths in directed graphs relative to two different cost functions ( , ). A possible interpretation of a directed graph is a network of roads so the weights for the function represent the length of roads, whereas the weights for the function represent a constraint of the width or weight of a vehicle. The optimization aim for those two functions is to minimize the cost relative to the function and maximize the constraint value associated with the function. This thesis also includes finding and proving the relation between the two different cost functions ( , ). When given a value of one function, we can find the best possible value for the other function. This relation is proven theoretically and also implemented and experimented using Matlab®[2].

  7. A chain-of-states acceleration method for the efficient location of minimum energy paths

    Energy Technology Data Exchange (ETDEWEB)

    Hernández, E. R., E-mail: Eduardo.Hernandez@csic.es; Herrero, C. P. [Instituto de Ciencia de Materiales de Madrid (ICMM–CSIC), Campus de Cantoblanco, 28049 Madrid (Spain); Soler, J. M. [Departamento de Física de la Materia Condensada and IFIMAC, Universidad Autónoma de Madrid, 28049 Madrid (Spain)

    2015-11-14

    We describe a robust and efficient chain-of-states method for computing Minimum Energy Paths (MEPs) associated to barrier-crossing events in poly-atomic systems, which we call the acceleration method. The path is parametrized in terms of a continuous variable t ∈ [0, 1] that plays the role of time. In contrast to previous chain-of-states algorithms such as the nudged elastic band or string methods, where the positions of the states in the chain are taken as variational parameters in the search for the MEP, our strategy is to formulate the problem in terms of the second derivatives of the coordinates with respect to t, i.e., the state accelerations. We show this to result in a very simple and efficient method for determining the MEP. We describe the application of the method to a series of test cases, including two low-dimensional problems and the Stone-Wales transformation in C{sub 60}.

  8. SEM technique for experimentally locating latch-up paths in integrated circuits

    International Nuclear Information System (INIS)

    Dressendorfer, P.V.; Armendariz, M.G.

    1980-01-01

    A technique is presented for using the scanning electron microscope (SEM) in the electron-beam-induced current (EBIC) mode to delineate latch-up paths in CMOS ICs. In the EBIC mode, the current produced by the collection and separation of the electron-beam-generated electron-hole pairs in the space charge regions of the device is measured and used to form an image. Since the collection of these carriers is dependent on space charge region width (and thus junction potential), anything that alters the depletion layer width will affect the collection efficiency. In a latch condition the junctions involved in the latch will be biased differently from those which are not, and thus the EBIC signal from those regions should be measurably different

  9. A new algorithm for least-cost path analysis by correcting digital elevation models of natural landscapes

    Science.gov (United States)

    Baek, Jieun; Choi, Yosoon

    2017-04-01

    Most algorithms for least-cost path analysis usually calculate the slope gradient between the source cell and the adjacent cells to reflect the weights for terrain slope into the calculation of travel costs. However, these algorithms have limitations that they cannot analyze the least-cost path between two cells when obstacle cells with very high or low terrain elevation exist between the source cell and the target cell. This study presents a new algorithm for least-cost path analysis by correcting digital elevation models of natural landscapes to find possible paths satisfying the constraint of maximum or minimum slope gradient. The new algorithm calculates the slope gradient between the center cell and non-adjacent cells using the concept of extended move-sets. If the algorithm finds possible paths between the center cell and non-adjacent cells with satisfying the constraint of slope condition, terrain elevation of obstacle cells existing between two cells is corrected from the digital elevation model. After calculating the cumulative travel costs to the destination by reflecting the weight of the difference between the original and corrected elevations, the algorithm analyzes the least-cost path. The results of applying the proposed algorithm to the synthetic data sets and the real-world data sets provide proof that the new algorithm can provide more accurate least-cost paths than other conventional algorithms implemented in commercial GIS software such as ArcGIS.

  10. Trade Costs and Location of Foreign Firms in China

    OpenAIRE

    International Monetary Fund

    2005-01-01

    This study examines the determinants of entry into by foreign firms, using information on 515 Chinese industries at the provincial level during 1998-2001. The analysis, rooted in the new economic geography, focuses on market and supplier access within and outside the province of entry, as well as production and trade costs. The results indicate that market and supplier access are the most important factors affecting foreign entry. Access to markets and suppliers in the province of entry matte...

  11. Efficient extraction of drainage networks from massive, radar-based elevation models with least cost path search

    Directory of Open Access Journals (Sweden)

    M. Metz

    2011-02-01

    Full Text Available The availability of both global and regional elevation datasets acquired by modern remote sensing technologies provides an opportunity to significantly improve the accuracy of stream mapping, especially in remote, hard to reach regions. Stream extraction from digital elevation models (DEMs is based on computation of flow accumulation, a summary parameter that poses performance and accuracy challenges when applied to large, noisy DEMs generated by remote sensing technologies. Robust handling of DEM depressions is essential for reliable extraction of connected drainage networks from this type of data. The least-cost flow routing method implemented in GRASS GIS as the module r.watershed was redesigned to significantly improve its speed, functionality, and memory requirements and make it an efficient tool for stream mapping and watershed analysis from large DEMs. To evaluate its handling of large depressions, typical for remote sensing derived DEMs, three different methods were compared: traditional sink filling, impact reduction approach, and least-cost path search. The comparison was performed using the Shuttle Radar Topographic Mission (SRTM and Interferometric Synthetic Aperture Radar for Elevation (IFSARE datasets covering central Panama at 90 m and 10 m resolutions, respectively. The accuracy assessment was based on ground control points acquired by GPS and reference points digitized from Landsat imagery along segments of selected Panamanian rivers. The results demonstrate that the new implementation of the least-cost path method is significantly faster than the original version, can cope with massive datasets, and provides the most accurate results in terms of stream locations validated against reference points.

  12. A novel cost-effective parallel narrowband ANC system with local secondary-path estimation

    Science.gov (United States)

    Delegà, Riccardo; Bernasconi, Giancarlo; Piroddi, Luigi

    2017-08-01

    Many noise reduction applications are targeted at multi-tonal disturbances. Active noise control (ANC) solutions for such problems are generally based on the combination of multiple adaptive notch filters. Both the performance and the computational cost are negatively affected by an increase in the number of controlled frequencies. In this work we study a different modeling approach for the secondary path, based on the estimation of various small local models in adjacent frequency subbands, that greatly reduces the impact of reference-filtering operations in the ANC algorithm. Furthermore, in combination with a frequency-specific step size tuning method it provides a balanced attenuation performance over the whole controlled frequency range (and particularly in the high end of the range). Finally, the use of small local models is greatly beneficial for the reactivity of the online secondary path modeling algorithm when the characteristics of the acoustic channels are time-varying. Several simulations are provided to illustrate the positive features of the proposed method compared to other well-known techniques.

  13. A Low-Cost Collaborative Location Scheme with GNSS and RFID for the Internet of Things

    Directory of Open Access Journals (Sweden)

    Changfeng Jing

    2018-05-01

    Full Text Available The emergence and development of the Internet of Things (IoT has attracted growing attention to low-cost location systems when facing the dramatically increased number of public infrastructure assets in smart cities. Various radio frequency identification (RFID-based locating systems have been developed. However, most of them are impractical for infrastructure asset inspection and management on a large scale due to their high cost, inefficient deployment, and complex environments such as emergencies or high-rise buildings. In this paper, we proposed a novel locating system by combing the Global Navigation Satellite System (GNSS with RFID, in which a target tag was located with one RFID reader and one GNSS receiver with sufficient accuracy for infrastructure asset management. To overcome the cost challenge, one mobile RFID reader-mounted GNSS receiver is used to simulate multiple location known reference tags. A vast number of reference tags are necessary for current RFID-based locating systems, which means higher cost. To achieve fine-grained location accuracy, we utilize a distance-based power law weight algorithm to estimate the exact coordinates. Our experiment demonstrates the effectiveness and advantages of the proposed scheme with sufficient accuracy, low cost and easy deployment on a large scale. The proposed scheme has potential applications for location-based services in smart cities.

  14. Do illness rating systems predict discharge location, length of stay, and cost after total hip arthroplasty?

    Directory of Open Access Journals (Sweden)

    Sarah E. Rudasill, BA

    2018-06-01

    Conclusions: These findings suggest that although ASA classifications predict discharge location and SOI scores predict length of stay and total costs, other factors beyond illness rating systems remain stronger predictors of discharge for THA patients.

  15. Approximation algorithms for facility location problems with a special class of subadditive cost functions

    NARCIS (Netherlands)

    Gabor, A.F.; Ommeren, van J.C.W.

    2006-01-01

    In this article we focus on approximation algorithms for facility location problems with subadditive costs. As examples of such problems, we present three facility location problems with stochastic demand and exponential servers, respectively inventory. We present a (1+e,1)-reduction of the facility

  16. Approximation algorithms for facility location problems with a special class of subadditive cost functions

    NARCIS (Netherlands)

    Gabor, Adriana F.; van Ommeren, Jan C.W.

    2006-01-01

    In this article we focus on approximation algorithms for facility location problems with subadditive costs. As examples of such problems, we present three facility location problems with stochastic demand and exponential servers, respectively inventory. We present a $(1+\\varepsilon, 1)$-reduction of

  17. Approximation algorithms for facility location problems with discrete subadditive cost functions

    NARCIS (Netherlands)

    Gabor, A.F.; van Ommeren, Jan C.W.

    2005-01-01

    In this article we focus on approximation algorithms for facility location problems with subadditive costs. As examples of such problems, we present two facility location problems with stochastic demand and exponential servers, respectively inventory. We present a $(1+\\epsilon,1)$- reduction of the

  18. Cost-Effective Location Management for Mobile Agents on the Internet

    Directory of Open Access Journals (Sweden)

    Chien-Sheng Chen

    2015-01-01

    Full Text Available Many mobile agent system-related services and applications require interacting with a mobile agent by passing messages. However, an agent’s mobility raises several challenges in delivering messages to a mobile agent accurately. Consisting of tracking and message delivery phases, most mobile agent location management schemes create or receive many update messages and interaction messages to ensure the effectiveness of the schemes. In addition to downgrading the overall performance of a mobile agent location management scheme, excessive transmission of messages increases the network load. The migration locality of a mobile agent and the interaction rate between mobile agents significantly affect the performance of a mobile agent location management scheme with respect to location management cost. This work presents a novel Dual Home based Scheme (DHS that can lower the location management costs in terms of migration locality and interaction rate. While the DHS scheme uniquely adopts dual home location management architecture, a selective update strategy based on that architecture is also designed for cost-effective location management of mobile agents. Moreover, DHS is compared with available schemes based on formulations and simulation experiments from the perspective of location management costs. Simulation results demonstrate that the proposed DHS scheme performs satisfactorily in terms of migration locality and interaction rate.

  19. The same-location cost is unrelated to attentional settings: an object-updating account.

    Science.gov (United States)

    Carmel, Tomer; Lamy, Dominique

    2014-08-01

    What mechanisms allow us to ignore salient yet irrelevant visual information has been a matter of intense debate. According to the contingent-capture hypothesis, such information is filtered out, whereas according to the salience-based account, it captures attention automatically. Several recent studies have reported a same-location cost that appears to fit neither of these accounts. These showed that responses may actually be slower when the target appears at the location just occupied by an irrelevant singleton distractor. Here, we investigated the mechanisms underlying this same-location cost. Our findings show that the same-location cost is unrelated to automatic attentional capture or strategic setting of attentional priorities, and therefore invalidate the feature-based inhibition and fast attentional disengagement accounts of this effect. In addition, we show that the cost is wiped out when the cue and target are not perceived as parts of the same object. We interpret these findings as indicating that the same-location cost has been previously misinterpreted by both bottom-up and top-down theories of attentional capture. We propose that it is better understood as a consequence of object updating, namely, as the cost of updating the information stored about an object when this object changes across time.

  20. Impacts of facility size and location decisions on ethanol production cost

    International Nuclear Information System (INIS)

    Kocoloski, Matt; Michael Griffin, W.; Scott Matthews, H.

    2011-01-01

    Cellulosic ethanol has been identified as a promising alternative to fossil fuels to provide energy for the transportation sector. One of the obstacles cellulosic ethanol must overcome in order to contribute to transportation energy demand is the infrastructure required to produce and distribute the fuel. Given a nascent cellulosic ethanol industry, locating cellulosic ethanol refineries and creating the accompanying infrastructure is essentially a greenfield problem that may benefit greatly from quantitative analysis. This study models cellulosic ethanol infrastructure investment using a mixed integer program (MIP) that locates ethanol refineries and connects these refineries to the biomass supplies and ethanol demands in a way that minimizes the total cost. For the single- and multi-state regions examined in this study, larger facilities can decrease ethanol costs by $0.20-0.30 per gallon, and placing these facilities in locations that minimize feedstock and product transportation costs can decrease ethanol costs by up to $0.25 per gallon compared to uninformed placement that could result from influences such as local subsidies to encourage economic development. To best benefit society, policies should allow for incentives that encourage these low-cost production scenarios and avoid politically motivated siting of plants. - Research highlights: → Mixed-integer programming can be used to model ethanol infrastructure investment. → Large cellulosic ethanol facilities can decrease production cost by $0.20/gallon. → Optimized facility placement can save $0.25/gallon.

  1. Coordination Costs for School-Located Influenza Vaccination Clinics, Maine, 2009 H1N1 Pandemic

    Science.gov (United States)

    Asay, Garrett R. Beeler; Cho, Bo-Hyun; Lorick, Suchita A.; Tipton, Meredith L.; Dube, Nancy L.; Messonnier, Mark L.

    2012-01-01

    School nurses played a key role in Maine's school-located influenza vaccination (SLV) clinics during the 2009-2010 pandemic season. The objective of this study was to determine, from the school district perspective, the labor hours and costs associated with outside-clinic coordination activities (OCA). The authors defined OCA as labor hours spent…

  2. 76 FR 64943 - Proposed Cercla Administrative Cost Recovery Settlement; ACM Smelter and Refinery Site, Located...

    Science.gov (United States)

    2011-10-19

    ... Settlement; ACM Smelter and Refinery Site, Located in Cascade County, MT AGENCY: Environmental Protection... projected future response costs concerning the ACM Smelter and Refinery NPL Site (Site), Operable Unit 1..., Helena, MT 59626. Mr. Sturn can be reached at (406) 457-5027. Comments should reference the ACM Smelter...

  3. State and location dependence of action potential metabolic cost in cortical pyramidal neurons

    NARCIS (Netherlands)

    Hallermann, Stefan; de Kock, Christiaan P. J.; Stuart, Greg J.; Kole, Maarten H. P.

    2012-01-01

    Action potential generation and conduction requires large quantities of energy to restore Na+ and K+ ion gradients. We investigated the subcellular location and voltage dependence of this metabolic cost in rat neocortical pyramidal neurons. Using Na+/K+ charge overlap as a measure of action

  4. State and location dependence of action potential metabolic cost in cortical pyramidal neurons

    NARCIS (Netherlands)

    Hallermann, S.; de Kock, C.P.J.; Stuart, G.J.; Kole, M.H.

    2012-01-01

    Action potential generation and conduction requires large quantities of energy to restore Na + and K + ion gradients. We investigated the subcellular location and voltage dependence of this metabolic cost in rat neocortical pyramidal neurons. Using Na +K + charge overlap as a measure of action

  5. School-located influenza vaccination with third-party billing: outcomes, cost, and reimbursement.

    Science.gov (United States)

    Kempe, Allison; Daley, Matthew F; Pyrzanowski, Jennifer; Vogt, Tara; Fang, Hai; Rinehart, Deborah J; Morgan, Nicole; Riis, Mette; Rodgers, Sarah; McCormick, Emily; Hammer, Anne; Campagna, Elizabeth J; Kile, Deidre; Dickinson, Miriam; Hambidge, Simon J; Shlay, Judith C

    2014-01-01

    To assess rates of immunization; costs of conducting clinics; and reimbursements for a school-located influenza vaccination (SLIV) program that billed third-party payers. SLIV clinics were conducted in 19 elementary schools in the Denver Public School district (September 2010 to February 2011). School personnel obtained parental consent, and a community vaccinator conducted clinics and performed billing. Vaccines For Children vaccine was available for eligible students. Parents were not billed for any fees. Data were collected regarding implementation costs and vaccine cost was calculated using published private sector prices. Reimbursement amounts were compared to costs. Overall, 30% of students (2784 of 9295) received ≥1 influenza vaccine; 39% (1079 of 2784) needed 2 doses and 80% received both. Excluding vaccine costs, implementation costs were $24.69 per vaccination. The percentage of vaccine costs reimbursed was 62% overall (82% from State Child Health Insurance Program (SCHIP), 50% from private insurance). The percentage of implementation costs reimbursed was 19% overall (23% from private, 27% from Medicaid, 29% from SCHIP and 0% among uninsured). Overall, 25% of total costs (implementation plus vaccine) were reimbursed. A SLIV program resulted in vaccination of nearly one third of elementary students. Reimbursement rates were limited by 1) school restrictions on charging parents fees, 2) low payments for vaccine administration from public payers and 3) high rates of denials from private insurers. Some of these problems might be reduced by provisions in the Affordable Care Act. Copyright © 2014 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

  6. Methodology of Evaluation of the Impact of Picking Area Location on the Total Costs of Warehouse

    Directory of Open Access Journals (Sweden)

    Apsalons Raitis

    2017-12-01

    Full Text Available The picking system and the layout of the picking area are the key drivers for the evaluation of a warehouse picking cost. There are five variants for organizing the picking process of orders in a warehouse. The choice of a specific variant depends on the total cost of picking. The picking cost is evaluated within an uninterrupted picking process. It means that no stock out occurs in the time period of the picking process. The storing area and the picking area are created as two separate zones for picking quantities of the customer’s orders; the principle of division of orders is observed strictly. Referring to the locations of stock keeping units (SKU, two approaches of the layout of SKU in the picking area can be estimated. The first one is the single picking location for each single SKU, where replenishment is realized in the picking process. The second one - various picking locations for each single SKU, and the replenishment here is realized just only prior to a picking process or after it. The main benefits of the economy of the picking cost as far as these two approaches are concerned are the shortest picking route in the first case and one common replenishment option in the second case.

  7. Identification of MHF (massive hydraulic fracturing) fracture planes and flow paths: A correlation of well log data with patterns in locations of induced seismicity

    Energy Technology Data Exchange (ETDEWEB)

    Dreesen, D.; Malzahn, M.; Fehler, M.; Dash, Z.

    1987-01-01

    One of the critical steps in developing a hot dry rock geothermal system is the creation of flow paths through the rock between two wellbores. To date, circulation systems have only been created by drilling one wellbore, hydraulically fracturing the well (which induces microearthquakes), locating the microearthquakes and then drilling a second wellbore through the zone of seismicity. A technique for analyzing the pattern of seismicity to determine where fracture planes are located in the seismically active region has recently been developed. This allows us to distinguish portions of the seismically active volume which are most likely to contain significant flow paths. We applied this technique to seismic data collected during a massive hydraulic fracturing (MHF) treatment and found that the fracture planes determined by the seismic method are confirmed by borehole temperature and caliper logs which indicate where permeable fractures and/or zones of weakness intersect the wellbores. A geometric model based on these planes and well log data has enhanced our understanding of the reservoir flow paths created by fracturing and is consistent with results obtained during production testing of the reservoir.

  8. Locating operations in high labor cost countries – Evidence from Spain

    Directory of Open Access Journals (Sweden)

    Angel Diaz

    2017-06-01

    Full Text Available The location of operations in high labor cost countries is increasingly discussed in the media, in part for recent declarations and actions from the president of USA, Donald Trump. While this particular instance can be labeled as populist or protectionist, the factors underlying the debate are extremely important: advances in systematic increases in productivity, low population growth, and the transfer of jobs to countries with lower labor costs are creating unemployment and underemployment in developed countries that could eventually result in protectionism and restrictions to free trade. This phenomenon has enormous social and economic implications, and has attracted considerable interest from researchers. In particular, this study provides empirical evidence of the location of manufacturing and services in the context of a European country (Spain, exploring the drivers, social implications and organizational theories that can explain it.

  9. Low-Cost Bluetooth Mobile Positioning for Location-based Application

    OpenAIRE

    Barahim, Zaafir; Doomun, M. Razvi; Joomun, Nazrana

    2012-01-01

    Bluetooth is a promising short-range radio network technology. We present a low cost and easily deployed, scalable infrastructure for indoor location-based computing of mobile devices based on Bluetooth technology. The system consists of 2 main components, namely the Bluetooth (BT) Sensor System and the Central Navigation System which have been developed using the JDK 6.0. The Bluetooth Sensor System allows mobile devices whose Bluetooth mode is set to discoverable, to be scanned and detected...

  10. State and location dependence of action potential metabolic cost in cortical pyramidal neurons.

    Science.gov (United States)

    Hallermann, Stefan; de Kock, Christiaan P J; Stuart, Greg J; Kole, Maarten H P

    2012-06-03

    Action potential generation and conduction requires large quantities of energy to restore Na(+) and K(+) ion gradients. We investigated the subcellular location and voltage dependence of this metabolic cost in rat neocortical pyramidal neurons. Using Na(+)/K(+) charge overlap as a measure of action potential energy efficiency, we found that action potential initiation in the axon initial segment (AIS) and forward propagation into the axon were energetically inefficient, depending on the resting membrane potential. In contrast, action potential backpropagation into dendrites was efficient. Computer simulations predicted that, although the AIS and nodes of Ranvier had the highest metabolic cost per membrane area, action potential backpropagation into the dendrites and forward propagation into axon collaterals dominated energy consumption in cortical pyramidal neurons. Finally, we found that the high metabolic cost of action potential initiation and propagation down the axon is a trade-off between energy minimization and maximization of the conduction reliability of high-frequency action potentials.

  11. Magnetized Target Fusion (MTF): A Low-Cost Fusion Development Path

    International Nuclear Information System (INIS)

    Lindemuth, I.R.; Siemon, R.E.; Kirkpatrick, R.C.; Reinovsky, R.E.

    1998-01-01

    Simple transport-based scaling laws are derived to show that a density and time regime intermediate between conventional magnetic confinement and conventional inertial confinement offers attractive reductions in system size and energy when compared to magnetic confinement and attractive reductions in heating power and intensity when compared to inertial confinement. This intermediate parameter space appears to be readily accessible by existing and near term pulsed power technologies. Hence, the technology of the Megagauss conference opens up an attractive path to controlled thermonuclear fusion

  12. Potential Offshore Wind Energy Areas in California: An Assessment of Locations, Technology, and Costs

    Energy Technology Data Exchange (ETDEWEB)

    Musial, Walter [National Renewable Energy Lab. (NREL), Golden, CO (United States); Beiter, Philipp [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tegen, Suzanne [National Renewable Energy Lab. (NREL), Golden, CO (United States); Smith, Aaron [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-12-01

    This report summarizes a study of possible offshore wind energy locations, technologies, and levelized cost of energy in the state of California between 2015 and 2030. The study was funded by the U.S. Department of the Interior's Bureau of Ocean Energy Management (BOEM), the federal agency responsible for regulating renewable energy development on the Outer Continental Shelf. It is based on reference wind energy areas where representative technology and performance characteristics were evaluated. These reference areas were identified as sites that were suitable to represent offshore wind cost and technology based on physical site conditions, wind resource quality, known existing site use, and proximity to necessary infrastructure. The purpose of this study is to assist energy policy decision-making by state utilities, independent system operators, state government officials and policymakers, BOEM, and its key stakeholders. The report is not intended to serve as a prescreening exercise for possible future offshore wind development.

  13. Low-cost asset tracking using location-aware camera phones

    Science.gov (United States)

    Chen, David; Tsai, Sam; Kim, Kyu-Han; Hsu, Cheng-Hsin; Singh, Jatinder Pal; Girod, Bernd

    2010-08-01

    Maintaining an accurate and up-to-date inventory of one's assets is a labor-intensive, tedious, and costly operation. To ease this difficult but important task, we design and implement a mobile asset tracking system for automatically generating an inventory by snapping photos of the assets with a smartphone. Since smartphones are becoming ubiquitous, construction and deployment of our inventory management solution is simple and costeffective. Automatic asset recognition is achieved by first segmenting individual assets out of the query photo and then performing bag-of-visual-features (BoVF) image matching on the segmented regions. The smartphone's sensor readings, such as digital compass and accelerometer measurements, can be used to determine the location of each asset, and this location information is stored in the inventory for each recognized asset. As a special case study, we demonstrate a mobile book tracking system, where users snap photos of books stacked on bookshelves to generate a location-aware book inventory. It is shown that segmenting the book spines is very important for accurate feature-based image matching into a database of book spines. Segmentation also provides the exact orientation of each book spine, so more discriminative upright local features can be employed for improved recognition. This system's mobile client has been implemented for smartphones running the Symbian or Android operating systems. The client enables a user to snap a picture of a bookshelf and to subsequently view the recognized spines in the smartphone's viewfinder. Two different pose estimates, one from BoVF geometric matching and the other from segmentation boundaries, are both utilized to accurately draw the boundary of each spine in the viewfinder for easy visualization. The BoVF representation also allows matching each photo of a bookshelf rack against a photo of the entire bookshelf, and the resulting feature matches are used in conjunction with the smartphone

  14. The Average Network Flow Problem: Shortest Path and Minimum Cost Flow Formulations, Algorithms, Heuristics, and Complexity

    Science.gov (United States)

    2012-09-13

    46, 1989. [75] S. Melkote and M.S. Daskin . An integrated model of facility location and transportation network design. Transportation Research Part A ... a work of the U.S. Government and is not subject to copyright protection in the United States. AFIT/DS/ENS/12-09 THE AVERAGE NETWORK FLOW PROBLEM...focused thinking (VFT) are used sparingly, as is the case across the entirety of the supply chain literature. We provide a VFT tutorial for supply chain

  15. IoT Enabled Low Cost Wearable Device for Location and Information Tracking System

    Directory of Open Access Journals (Sweden)

    Kamaludin Nur Atika Binti

    2017-01-01

    Full Text Available An internet-of-things (IoT enabled low cost wearable device for location and information tracking system is developed to monitor and ensure the safety of the children while their parents are away either to work or abroad. This system aims to ensure human safety especially the children and efficiently initiate search and rescue in the event of emergencies. The device will notify the parents on the condition of the surroundings of the children, specifically inside the house and notify the parents if the children are outside the target area by using the application developed in the smartphone. The system uses a microcomputer called Beagle-Bone Black (BBB as the processor while GPS and LTE technology for wireless communication. Future improvement mainly focuses on reducing the size and power consumption of the device, improving communication module, and optimizing microcomputer’s specification.

  16. Cost Optimisation in Freight Distribution with Cross-Docking: N-Echelon Location Routing Problem

    Directory of Open Access Journals (Sweden)

    Jesus Gonzalez-Feliu

    2012-03-01

    Full Text Available Freight transportation constitutes one of the main activities that influence the economy and society, as it assures a vital link between suppliers and customers and represents a major source of employment. Multi-echelon distribution is one of the most common strategies adopted by the transportation companies in an aim of cost reduction. Although vehicle routing problems are very common in operational research, they are essentially related to single-echelon cases. This paper presents the main concepts of multi-echelon distribution with cross-docks and a unified notation for the N-echelon location routing problem. A literature review is also presented, in order to list the main problems and methods that can be helpful for scientists and transportation practitioners.

  17. Adaptation of Dubins Paths for UAV Ground Obstacle Avoidance When Using a Low Cost On-Board GNSS Sensor.

    Science.gov (United States)

    Kikutis, Ramūnas; Stankūnas, Jonas; Rudinskas, Darius; Masiulionis, Tadas

    2017-09-28

    Current research on Unmanned Aerial Vehicles (UAVs) shows a lot of interest in autonomous UAV navigation. This interest is mainly driven by the necessity to meet the rules and restrictions for small UAV flights that are issued by various international and national legal organizations. In order to lower these restrictions, new levels of automation and flight safety must be reached. In this paper, a new method for ground obstacle avoidance derived by using UAV navigation based on the Dubins paths algorithm is presented. The accuracy of the proposed method has been tested, and research results have been obtained by using Software-in-the-Loop (SITL) simulation and real UAV flights, with the measurements done with a low cost Global Navigation Satellite System (GNSS) sensor. All tests were carried out in a three-dimensional space, but the height accuracy was not assessed. The GNSS navigation data for the ground obstacle avoidance algorithm is evaluated statistically.

  18. Adaptation of Dubins Paths for UAV Ground Obstacle Avoidance When Using a Low Cost On-Board GNSS Sensor

    Directory of Open Access Journals (Sweden)

    Ramūnas Kikutis

    2017-09-01

    Full Text Available Current research on Unmanned Aerial Vehicles (UAVs shows a lot of interest in autonomous UAV navigation. This interest is mainly driven by the necessity to meet the rules and restrictions for small UAV flights that are issued by various international and national legal organizations. In order to lower these restrictions, new levels of automation and flight safety must be reached. In this paper, a new method for ground obstacle avoidance derived by using UAV navigation based on the Dubins paths algorithm is presented. The accuracy of the proposed method has been tested, and research results have been obtained by using Software-in-the-Loop (SITL simulation and real UAV flights, with the measurements done with a low cost Global Navigation Satellite System (GNSS sensor. All tests were carried out in a three-dimensional space, but the height accuracy was not assessed. The GNSS navigation data for the ground obstacle avoidance algorithm is evaluated statistically.

  19. Target-to-Target Repetition Cost and Location Negative Priming Are Dissociable: Evidence for Different Mechanisms

    Science.gov (United States)

    Chao, Hsuan-Fu

    2011-01-01

    In a location-selection task, the repetition of a prior distractor location as the target location would slow down the response. This effect is termed the location negative priming (NP) effect. Recently, it has been demonstrated that repetition of a prior target location as the current target location would also slow down response. Because such…

  20. Low-Cost Impact Detection and Location for Automated Inspections of 3D Metallic Based Structures

    Directory of Open Access Journals (Sweden)

    Carlos Morón

    2015-05-01

    Full Text Available This paper describes a new low-cost means to detect and locate mechanical impacts (collisions on a 3D metal-based structure. We employ the simple and reasonably hypothesis that the use of a homogeneous material will allow certain details of the impact to be automatically determined by measuring the time delays of acoustic wave propagation throughout the 3D structure. The location of strategic piezoelectric sensors on the structure and an electronic-computerized system has allowed us to determine the instant and position at which the impact is produced. The proposed automatic system allows us to fully integrate impact point detection and the task of inspecting the point or zone at which this impact occurs. What is more, the proposed method can be easily integrated into a robot-based inspection system capable of moving over 3D metallic structures, thus avoiding (or minimizing the need for direct human intervention. Experimental results are provided to show the effectiveness of the proposed approach.

  1. The antisaccade task: visual distractors elicit a location-independent planning 'cost'.

    Science.gov (United States)

    DeSimone, Jesse C; Everling, Stefan; Heath, Matthew

    2015-01-01

    The presentation of a remote - but not proximal - distractor concurrent with target onset increases prosaccade reaction times (RT) (i.e., the remote distractor effect: RDE). The competitive integration model asserts that the RDE represents the time required to resolve the conflict for a common saccade threshold between target- and distractor-related saccade generating commands in the superior colliculus. To our knowledge however, no previous research has examined whether remote and proximal distractors differentially influence antisaccade RTs. This represents a notable question because antisaccades require decoupling of the spatial relations between stimulus and response (SR) and therefore provide a basis for determining whether the sensory- and/or motor-related features of a distractor influence response planning. Participants completed pro- and antisaccades in a target-only condition and conditions wherein the target was concurrently presented with a proximal or remote distractor. As expected, prosaccade RTs elicited a reliable RDE. In contrast, antisaccade RTs were increased independent of the distractor's spatial location and the magnitude of the effect was comparable across each distractor location. Thus, distractor-related antisaccade RT costs are not accounted for by a competitive integration between conflicting saccade generating commands. Instead, we propose that a visual distractor increases uncertainty related to the evocation of the response-selection rule necessary for decoupling SR relations.

  2. Diagnostic and therapeutic path of breast cancer: effectiveness, appropriateness, and costs – results from the DOCMa study

    Directory of Open Access Journals (Sweden)

    Giovagnoli MR

    2015-04-01

    Full Text Available Maria Rosaria Giovagnoli,1 Adriana Bonifacino,2 Cosimo Neglia,3 Marco Benvenuto,3,4 Francesco Vincenzo Sambati,3 Lorenzo Giolli,5 Alessandra Giovagnoli,6 Prisco Piscitelli7,8 1Department of Clinical and Molecular Medicine, 2Department of Medical-Surgical Sciences and Translational Medicine, Sapienza University of Rome, Sant’Andrea University Hospital, Rome, 3Euro Mediterranean Scientific Biomedical Institute (ISBEM, Brindisi, 4Department of Economics, Scuola Superiore Sant’Anna, Pisa, 5eCampus University, Novedrate, 6Department of Statistical Sciences, University of Bologna, Bologna, 7Coleman Ltd, 8IOS, Southern Italy Hospital Institute, Naples, ItalyObjective: An increase in breast cancer incidence has been documented in Italy and in other countries, and some women decide by themselves to undergo diagnostic examinations outside the official screening campaigns. The aim of this paper was to analyze – in terms of effectiveness, appropriate access, and related costs – the path spontaneously followed by a sample of Italian women for the early diagnosis of breast cancer.Subjects and methods: A total of 143 women who consecutively referred themselves to the breast cancer outpatient facilities at the Sant’Andrea University Hospital in Rome from May to June 2007 were enrolled in the study, gave their consent, and were screened according to their individual risk factors for breast cancer. The entire diagnostic and therapeutic path followed in the previous 2 years by each of them, either at Sant’Andrea or in other medical facilities, was reviewed and evaluated in terms of its operative efficiency and fair economic value.Results: The subjects’ mean age was 47.5 years (standard deviation 13.6 years; 55% of the women were <50 years old (28% <40 years, and were thus not included in the official screening campaigns; 97 women (70% were requesting a routine control; and 49% of them had already undergone four to seven examinations before the

  3. Baseline System Costs for 50.0 MW Enhanced Geothermal System -- A Function of: Working Fluid, Technology, and Location, Location, Location

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, Paul [Gas Equipment Engineering Corp., Milford, CT (United States); Selman, Nancy [Gas Equipment Engineering Corp., Milford, CT (United States); Volpe, Anthony Della [Gas Equipment Engineering Corp., Milford, CT (United States); Moss, Deborah [Gas Equipment Engineering Corp., Milford, CT (United States); Mobley, Rick [Plasma Energy Services, LLC, Putnam, CT (United States); Dickey, Halley [Turbine Air Systems, Houston, TX (United States); Unruh, Jeffery [Fugro NV/Wm. Lettis & Associates, Houston, TX (United States); Hitchcock, Chris [Fugro NV/Wm. Lettis & Associates, Houston, TX (United States); Tanguay, Jasmine [Conservation Law Foundation/CLF Ventures, Boston, MA (United States); Larsen, Walker [Conservation Law Foundation/CLF Ventures, Boston, MA (United States); Sanyal, Sabir [GeothermEx, Inc., San Pablo, CA (United States); Butler, Steven [GeothermEx, Inc., San Pablo, CA (United States); Stacey, Robert [GeothermEx, Inc., San Pablo, CA (United States); Robertson-Tait, Ann [GeothermEx, Inc., San Pablo, CA (United States); Pruess, Karsten [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gutoski, Greg [Fairbanks Morse Engines (FME), Beloit, WI (United States); Fay, Jamie M. [Fort Point Associates, Boston, MA (United States); Stitzer, John T. [Fort Point Associates, Boston, MA (United States); Oglesby, Ken [Impact Technologies LLC, Tulsa, OK (United States)

    2012-04-30

    Substantial unexploited opportunity exists for the US, and the world, in Enhanced Geothermal Systems (EGS). As a result of US DOE investment, new drilling technology, new power generation equipment and cycles enable meaningful power production, in a compact and modular fashion; at lower and lower top side EGS working fluid temperatures and in a broader range of geologies and geographies. This cost analysis effort supports the expansion of Enhanced Geothermal Systems (EGS), furthering DOE strategic themes of energy security and sub goal of energy diversity; reducing the Nation's dependence on foreign oil while improving the environment.

  4. The influence of (toll-related) travel costs in residential location decisions of households : A stated choice approach

    NARCIS (Netherlands)

    Tillema, T.; van Wee, B.; Ettema, D.

    2010-01-01

    In this paper, we investigate the impact of travel costs, in particular toll costs, on the residential location choice of households, using a stated choice survey. Within the stated choice experiment, car drivers that frequently face traffic congestion, traded-off several trip-related (including

  5. A Path-Based Gradient Projection Algorithm for the Cost-Based System Optimum Problem in Networks with Continuously Distributed Value of Time

    Directory of Open Access Journals (Sweden)

    Wen-Xiang Wu

    2014-01-01

    Full Text Available The cost-based system optimum problem in networks with continuously distributed value of time is formulated as a path-based form, which cannot be solved by the Frank-Wolfe algorithm. In light of magnitude improvement in the availability of computer memory in recent years, path-based algorithms have been regarded as a viable approach for traffic assignment problems with reasonably large network sizes. We develop a path-based gradient projection algorithm for solving the cost-based system optimum model, based on Goldstein-Levitin-Polyak method which has been successfully applied to solve standard user equilibrium and system optimum problems. The Sioux Falls network tested is used to verify the effectiveness of the algorithm.

  6. Application of Synthetic Storm Technique for Diurnal and Seasonal Variation of Slant Path Ka-Band Rain Attenuation Time Series over a Subtropical Location in South Africa

    Directory of Open Access Journals (Sweden)

    J. S. Ojo

    2015-01-01

    Full Text Available As technology advances and more demands are on satellite services, rain-induced attenuation still creates one of the most damaging effects of the atmosphere on the quality of radio communication signals, especially those operating above 10 GHz. System designers therefore require statistical information on rain-induced attenuation over the coverage area in order to determine the appropriate transmitter and receiver characteristics to be adopted. This paper presents results on the time-varying rain characterization and diurnal variation of slant path rain attenuation in the Ka-band frequency simulated with synthetic storm techniques over a subtropical location in South Africa using 10-year rain rate time-series data. The analysis is based on the CDF of one-minute rain rate; time-series seasonal variation of rain rate observed over four time intervals: 00:00–06:00, 06:00–12:00, 12:00–18:00, and 18:00–24:00; diurnal fades margin; and diurnal variation of rain attenuation. Comparison was also made between the synthesized values and measured attenuation data. The predicted statistics are in good agreement with those obtained from the propagation beacon measurement in the area. The overall results will be needed for an acceptable planning that can effectively reduce the fade margin to a very low value for an optimum data communication over this area.

  7. 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…

  8. Assessment of waterfront location in hardened concrete by GPR within COST Action TU1208

    Science.gov (United States)

    Rodríguez-Abad, Isabel; Klysz, Gilles; Balayssac, Jean Paul; Pajewski, Lara

    2016-04-01

    This work focuses on the analysis of the capability of Ground-Penetrating radar (GPR) technique for evaluating how the water penetrates into concrete samples by means of the assessment of the waterfront advance. Research activities have been carried out during a Short-Term Scientific Missions (STSMs) funded by the COST (European Cooperation in Science and Technology) Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar" in November 2015. The evaluation of water penetrability is crucial in most building materials, such us concrete, since, water and aggressive chemical agents dissolved therein contribute to the deterioration of the material. A number of techniques have been developed to measure their advance in concrete. Although the most common method for measuring water content is the gravimetric method by observing the change in mass, this method has a large number of disadvantages. In this context, non-destructive techniques as GPR play an interesting role. In particular, the application of GPR in the building materials area is providing very promising and interesting results regarding the building materials characterization and especially concrete deterioration evaluation [1-3]. In addition, recent experimental studies highlight the strong relation between wave propagation parameters (velocity and energy level) and water content advance [4-5]. Water content has a decisive influence on dielectric properties and those might be assessed by the study of the wave properties that are derived by using GPR. Therefore, the waterfront advance will result in a change on wave parameters. In line with this, this research is focused on the development of specific processing algorithms necessary to understand how the water penetrates and how the wave parameters will be affected regarding the location of the antenna in reference to the water absorption direction. For this purpose, concrete samples were manufactured, which after curing (90 days) and oven

  9. Location, location, location

    NARCIS (Netherlands)

    Anderson, S.P.; Goeree, J.K.; Ramer, R.

    1997-01-01

    We analyze the canonical location-then-price duopoly game with general log- concave consumer densities. A unique pure-strategy equilibrium to the two-stage game exists if the density is not "too asymmetric" and not "too concave." These criteria are satisfied by many commonly used densities.

  10. How do we select multiple features? Transient costs for selecting two colors rather than one, persistent costs for color-location conjunctions.

    Science.gov (United States)

    Lo, Shih-Yu; Holcombe, Alex O

    2014-02-01

    In a previous study Lo, Howard, & Holcombe (Vision Research 63:20-33, 2012), selecting two colors did not induce a performance cost, relative to selecting one color. For example, requiring possible report of both a green and a red target did not yield a worse performance than when both targets were green. Yet a cost of selecting multiple colors was observed when selection needed be contingent on both color and location. When selecting a red target to the left and a green target to the right, superimposing a green distractor to the left and a red distractor to the right impeded performance. Possibly, participants cannot confine attention to a color at a particular location. As a result, distractors that share the target colors disrupt attentional selection of the targets. The attempt to select the targets must then be repeated, which increases the likelihood that the trial terminates when selection is not effective, even for long trials. Consistent with this, here we find a persistent cost of selecting two colors when the conjunction of color and location is needed, but the cost is confined to short exposure durations when the observer just has to monitor red and green stimuli without the need to use the location information. These results suggest that selecting two colors is time-consuming but effective, whereas selection of simultaneous conjunctions is never entirely successful.

  11. Is there any way out there? Environmental and cultural influences in computing least-cost paths with GIS

    Directory of Open Access Journals (Sweden)

    Fairén Jiménez, Sara

    2004-12-01

    Full Text Available One of the most interesting subjects in post-structural landscape studies is the analysis of the relationships between its natural and cultural components: the structuring of the landscape, with the identification of the social practices and patterns of movement that took part around them. These patterns depend both on the natural form of the terrain and on socio-cultural decisions. In relation to the settlement pattern and distribution of rock art sites in the central- Mediterranean coastal area of Spain, a method is proposed to evaluate the role of cultural aspects of landscape in computing least-cost paths.

    Entre los recientes estudios dentro de la Arqueología del Paisaje, uno de los aspectos que presenta mayor potencial interpretativo es el análisis de la relación entre sus distintos componentes naturales y culturales: la articulación del paisaje – con la identificación de las prácticas sociales que se realizarían en torno a estos elementos y de las pautas de movimiento entre unos y otros. Este movimiento dependería tanto de las características naturales del terreno como de decisiones prácticas de carácter socio-cultural. A partir del estudio de la distribución del poblamiento y abrigos con arte rupestre neolíticos en las tierras centro-meridionales valencianas, se propone un sistema para la introducción y valoración del papel de los componentes culturales del paisaje en el cálculo de caminos óptimos mediante Sistemas de Información Geográfica.

  12. A branch-and-bound algorithm for the capacitated facility location problem with convex production costs

    DEFF Research Database (Denmark)

    Klose, Andreas

    solution approaches: The use of perspective cuts, a second-order cone (SOC) MIP formulation for the case of quadratic costs, and Benders’ decomposition. Our computational results indicate that in many case the branch-and-bound method is superior to both the perspective cut approach, the SOC MIP...

  13. A Linear Programming Approach for Determining Travel Cost Minimizing ECSS Training Locations

    Science.gov (United States)

    2010-03-01

    can accommodate the simultaneous training of many personnel. 1. Gulfport CRTC, Mississippi 2. Savannah CRTC, Georgia 3. Alpena CRTC, Michigan 4...327 224 Savannah CRTC 266 182 Alpena CRTC 493 343 Volk Field CRTC 136 91 Hill ALC 210 147 Hanscom ALC 414 287 Tinker ALC 620 434 Robins ALC 1332...Location Frequency within Optimal Solutions across All Phases 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Gulfport CRTC Savannah CRTC Alpena CRTC Volk

  14. Cost-Effective Location Management for Mobile Agents on the Internet

    OpenAIRE

    Chien-Sheng Chen; Jiing-Dong Hwang; Chyuan-Der Lu; Ting-Yuan Yeh

    2015-01-01

    Many mobile agent system-related services and applications require interacting with a mobile agent by passing messages. However, an agent’s mobility raises several challenges in delivering messages to a mobile agent accurately. Consisting of tracking and message delivery phases, most mobile agent location management schemes create or receive many update messages and interaction messages to ensure the effectiveness of the schemes. In addition to downgrading the overall performance of a mobile ...

  15. Application of Activity-Based Costing Management System by Key Success Paths to Promote the Competitive Advantages and Operation Performance

    OpenAIRE

    Mei-Fang Wu; Shu-Li Wang; Feng-Tsung Cheng

    2015-01-01

    Highly developed technology and highly competitive global market highlight the important role of competitive advantages and operation performances in sustainable company operation. Activity-Based Costing (ABC) provides accurate operation cost and operation performance information. Rich literatures provide relevant research with cases study on Activity-Based Costing application, but the research on cause relationship between key success factors and its specific outcome, su...

  16. Low Cost Open-Path Instrument for Monitoring Surface Carbon Dioxide at Sequestration Sites Phase I SBIR Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Sheng

    2012-10-02

    Public confidence in safety is a prerequisite to the success of carbon dioxide (CO2) capture and storage for any program that intends to mitigate greenhouse gas emissions. In that regard, this project addresses the security of CO2 containment by undertaking development of what is called an open path device to measure CO2 concentrations near the ground above a CO2 storage area.

  17. On the Path to SunShot. The Role of Advancements in Solar Photovoltaic Efficiency, Reliability, and Costs

    Energy Technology Data Exchange (ETDEWEB)

    Woodhouse, Michael [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jones-Albertus, Rebecca [U.S. Dept. of Energy, Washington, DC (United States); Feldman, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Fu, Ran [National Renewable Energy Lab. (NREL), Golden, CO (United States); Horowitz, Kelsey [National Renewable Energy Lab. (NREL), Golden, CO (United States); Chung, Donald [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jordan, Dirk [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kurtz, Sarah [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-05-01

    This report examines the remaining challenges to achieving the competitive photovoltaic (PV) costs and large-scale deployment envisioned under the U.S. Department of Energy's SunShot Initiative. Solar-energy cost reductions can be realized through lower PV module and balance-of-system (BOS) costs as well as improved system efficiency and reliability. Numerous combinations of PV improvements could help achieve the levelized cost of electricity (LCOE) goals because of the tradeoffs among key metrics like module price, efficiency, and degradation rate as well as system price and lifetime. Using LCOE modeling based on bottom-up cost analysis, two specific pathways are mapped to exemplify the many possible approaches to module cost reductions of 29%-38% between 2015 and 2020. BOS hardware and soft cost reductions, ranging from 54%-77% of total cost reductions, are also modeled. The residential sector's high supply-chain costs, labor requirements, and customer-acquisition costs give it the greatest BOS cost-reduction opportunities, followed by the commercial sector, although opportunities are available to the utility-scale sector as well. Finally, a future scenario is considered in which very high PV penetration requires additional costs to facilitate grid integration and increased power-system flexibility--which might necessitate even lower solar LCOEs. The analysis of a pathway to 3-5 cents/kWh PV systems underscores the importance of combining robust improvements in PV module and BOS costs as well as PV system efficiency and reliability if such aggressive long-term targets are to be achieved.

  18. Optimization of Reliability Centered Maintenance Bassed on Maintenance Costs and Reliability with Consideration of Location of Components

    Directory of Open Access Journals (Sweden)

    Mahdi Karbasian

    2011-03-01

    Full Text Available The reliability of designing systems such as electrical and electronic circuits, power generation/ distribution networks and mechanical systems, in which the failure of a component may cause the whole system failure, and even the reliability of cellular manufacturing systems that their machines are connected to as series are critically important. So far approaches for improving the reliability of these systems have been mainly based on the enhancement of inherent reliability of any system component or increasing system reliability based on maintenance strategies. Also in some of the resources, only the influence of the location of systems' components on reliability is studied. Therefore, it seems other approaches have been rarely applied. In this paper, a multi criteria model has been proposed to perform a balance among a system's reliability, location costs, and its system maintenance. Finally, a numerical example has been presented and solved by the Lingo software.

  19. 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.

  20. The effect of location and facility demand on the marginal cost of delivered wood chips from energy crops: A case study of the state of Tennessee

    International Nuclear Information System (INIS)

    Graham, R.L.; Liu, W.; Downing, M.; Noon, C.; Daly, M.; Moore, A.

    1995-01-01

    Cost-supply curves for delivered wood chips from short rotation woody crops were calculated for 21 regularly-spaced locations spanning the state of Tennessee. These curves were used to systematically evaluate the combined effects of location and facility demand on wood chip feedstock costs in Tennessee. The cost-supply curves were developed using BRAVO, a GIS-based decision support system which calculates marginal cost of delivering wood chips to a specific location given road network maps and maps of farmgate prices and supplies of woody chips from short rotation energy crops. Marginal costs of delivered chips varied by both facility location in the state and facility demand. Marginal costs were lowest in central Tennessee unless the facility demand was greater than 2.7 million dry Mg per year (3 million dry tons per year) in which case west Tennessee was the lowest cost region. Marginal costs rose rapidly with increasing facility demand in the mountainous eastern portion of the state. Transportation costs accounted for 18 to 29% of the delivered cost and ranged between $8 and $18/dry Mg ($7 and $16/dry ton). Reducing the expected farmer participation rate from 100% to 50% or 25% dramatically raised the marginal costs of feedstock supply in the east and central regions of the state. The analysis demonstrates the need to use geographically-specific information when projecting the potential costs and supplies of biomass feedstock

  1. MRS/IS facility co-located with a repository: preconceptual design and life-cycle cost estimates

    International Nuclear Information System (INIS)

    Smith, R.I.; Nesbitt, J.F.

    1982-11-01

    A program is described to examine the various alternatives for monitored retrievable storage (MRS) and interim storage (IS) of spent nuclear fuel, solidified high-level waste (HLW), and transuranic (TRU) waste until appropriate geologic repository/repositories are available. The objectives of this study are: (1) to develop a preconceptual design for an MRS/IS facility that would become the principal surface facility for a deep geologic repository when the repository is opened, (2) to examine various issues such as transportation of wastes, licensing of the facility, and environmental concerns associated with operation of such a facility, and (3) to estimate the life cycle costs of the facility when operated in response to a set of scenarios which define the quantities and types of waste requiring storage in specific time periods, which generally span the years from 1990 until 2016. The life cycle costs estimated in this study include: the capital expenditures for structures, casks and/or drywells, storage areas and pads, and transfer equipment; the cost of staff labor, supplies, and services; and the incremental cost of transporting the waste materials from the site of origin to the MRS/IS facility. Three scenarios are examined to develop estimates of life cycle costs of the MRS/IS facility. In the first scenario, HLW canisters are stored, starting in 1990, until the co-located repository is opened in the year 1998. Additional reprocessing plants and repositories are placed in service at various intervals. In the second scenario, spent fuel is stored, starting in 1990, because the reprocessing plants are delayed in starting operations by 10 years, but no HLW is stored because the repositories open on schedule. In the third scenario, HLW is stored, starting in 1990, because the repositories are delayed 10 years, but the reprocessing plants open on schedule

  2. Centralized manure digestion. Selection of locations and estimation of costs of large-scale manure storage application

    International Nuclear Information System (INIS)

    1995-03-01

    A study to assess the possibilities and the consequences of the use of existing Dutch large scale manure silos at centralised anaerobic digestion plants (CAD-plants) for manure and energy-rich organic wastes is carried out. Reconstruction of these large scale manure silos into digesters for a CAD-plant is not self-evident due to the high height/diameter ratio of these silos and the extra investments that have to be made for additional facilities for roofing, insulation, mixing and heating. From the results of an inventory and selection of large scale manure silos with a storage capacity above 1,500 m 3 it appeared that there are 21 locations in The Netherlands that can be qualified for realisation of a CAD plant with a processing capacity of 100 m 3 biomass (80% manure, 20% additives) per day. These locations are found in particular at the 'shortage-areas' for manure fertilisation in the Dutch provinces Groningen and Drenthe. Three of these 21 locations with large scale silos are considered to be the most suitable for realisation of a large scale CAD-plant. The selection is based on an optimal scale for a CAD-plant of 300 m 3 material (80% manure, 20% additives) to be processed per day and the most suitable consuming markets for the biogas produced at the CAD-plant. The three locations are at Middelharnis, Veendam, and Klazinaveen. Applying the conditions as used in this study and accounting for all costs for transport of manure, additives and end-product including the costs for the storage facilities, a break-even operation might be realised at a minimum income for the additives of approximately 50 Dutch guilders per m 3 (including TAV). This income price is considerably lower than the prevailing costs for tipping or processing of organic wastes in The Netherlands. This study revealed that a break-even exploitation of a large scale CAD-plant for the processing of manure with energy-rich additives is possible. (Abstract Truncated)

  3. PENGEVALUASIAN KOMPARASI DARI EFEK SISTEM KONTROL MANAJEMEN MANUFAKTUR KINERJA SAAT OPERASIONAL DENGAN PROGRAM AUDITAN BERBASIS HISTORICAL COST BERPOSTULAT GOING CONCERN: MODEL PATH ANALITIS

    Directory of Open Access Journals (Sweden)

    Petrolis Nusa Perdana

    2017-03-01

    Full Text Available Comparison of the Effects Evaluating Management Control System Manufacturing Current Performance Based Operational Program Audited Historical Cost that postuled Going Concern: Path Analytic Model. Faculty of Economics, University of Jakarta. 2016 This study uses a linear model of structural relations (LISREL to investigate the influence of management control system (that is the objectives associated with quality, quality feedback and incentive-compensation on the suitability of the quality and suistainability influence on the quality of customer satisfaction. Comparison management control on the spot with the results of normative audited based on historical cost with going concern postulated where the results show support for the theoretical framework that links objectives, feedback and incentives for quality conformance which is more optimal than the evaluation of past or simultaneously with current implementation. The results also demonstrate the suitability of which has a significant impact on customer satisfaction and also mediates the relationship between the management control system, audit results and customer satisfaction.

  4. Physical mechanism of mind changes and tradeoffs among speed, accuracy, and energy cost in brain decision making: Landscape, flux, and path perspectives

    International Nuclear Information System (INIS)

    Yan Han; Wang Jin; Zhang Kun

    2016-01-01

    Cognitive behaviors are determined by underlying neural networks. Many brain functions, such as learning and memory, have been successfully described by attractor dynamics. For decision making in the brain, a quantitative description of global attractor landscapes has not yet been completely given. Here, we developed a theoretical framework to quantify the landscape associated with the steady state probability distributions and associated steady state curl flux, measuring the degree of non-equilibrium through the degree of detailed balance breaking for decision making. We quantified the decision-making processes with optimal paths from the undecided attractor states to the decided attractor states, which are identified as basins of attractions, on the landscape. Both landscape and flux determine the kinetic paths and speed. The kinetics and global stability of decision making are explored by quantifying the landscape topography through the barrier heights and the mean first passage time. Our theoretical predictions are in agreement with experimental observations: more errors occur under time pressure. We quantitatively explored two mechanisms of the speed-accuracy tradeoff with speed emphasis and further uncovered the tradeoffs among speed, accuracy, and energy cost. Our results imply that there is an optimal balance among speed, accuracy, and the energy cost in decision making. We uncovered the possible mechanisms of changes of mind and how mind changes improve performance in decision processes. Our landscape approach can help facilitate an understanding of the underlying physical mechanisms of cognitive processes and identify the key factors in the corresponding neural networks. (paper)

  5. Ecological Security Pattern Analysis Based on InVEST and Least-Cost Path Model: A Case Study of Dongguan Water Village

    Directory of Open Access Journals (Sweden)

    Qian Lin

    2016-02-01

    Full Text Available The famous “world’s factory” city, Dongguan, like many other places in China, is a typical beneficiary of China’s Reform and Opening-up Policy. However, rapid urban sprawl and economic growth are at the expense of the destruction of the local environment. Therefore, it is of great importance to establish an ecological security network for sustainable development. InVEST models, effective tools to measure sensitivity and intensity of external threats to quantify habitat value, are used to calculate habitat quality of water and land. By combining structural connectivity and the Least-Cost Path model (LCP model, in which corridors are determined based on the minimum accumulative cost path between each critical point, ecological security patterns were calculated. According to the results, the northwest region of Dongguan, having a large quantity of farmlands and water and therefore many corridors and critical patches, is the most essential area in the overall security of ecological environments, which should be protected first. If developed, it should be dominated by eco-tourism and eco-agriculture. We hope that research on the ecological network, which includes critical patches and corridors formed by greenland and rivers, will lead toward better-informed proposals for local urban planning and regional sustainable development.

  6. Estimating cost-effectiveness of mass cardiopulmonary resuscitation training strategies to improve survival from cardiac arrest in private locations.

    Science.gov (United States)

    Swor, Robert; Compton, Scott

    2004-01-01

    Most cardiopulmonary resuscitation (CPR) trainees are young, and most cardiac arrests occur in private residences witnessed by older individuals. To estimate the cost-effectiveness of a CPR training program targeted at citizens over the age of 50 years compared with that of current nontargeted public CPR training. A model was developed using cardiac arrest and known demographic data from a single suburban zip code (population 36,325) including: local data (1997-1999) regarding cardiac arrest locations (public vs. private); incremental survival with CPR (historical survival rate 7.8%, adjusted odds ratio for CPR 2.0); arrest bystander demographics obtained from bystander telephone interviews; zip code demographics regarding population age and distribution; and 12.50 dollars per student for the cost of CPR training. Published rates of CPR training programs by age were used to estimate the numbers typically trained. Several assumptions were made: 1) there would be one bystander per. arrest; 2) the bystander would always perform CPR if trained; 3) cardiac arrest would be evenly distributed in the population; and 4) CPR training for a proportion of the population would proportionally increase CPR provision. Rates of arrest, bystanders by age, number of CPR trainees needed to result in increased arrest survival, and training cost per life saved for a one-year study period were calculated. There were 24.3 cardiac arrests per year, with 21.9 (90%) occurring in homes. In 66.5% of the home arrests, the bystander was more than 50 years old. To yield one additional survivor using the current CPR training strategy, 12,306 people needed to be trained (3,510 bystanders aged 50 years), which resulted in CPR provision to 7.14 additional patients. The training cost per life saved for a bystander aged 50 years was 785,040 dollars. Using a strategy of training only those cost of 53,383 dollars per life saved. Using these assumptions, current CPR training strategy is not a cost

  7. Designing and evaluation of three alternatives highway routes using the Analytical Hierarchy Process and the least-cost path analysis, application in Sinai Peninsula, Egypt

    Directory of Open Access Journals (Sweden)

    Hala A. Effat

    2013-12-01

    Full Text Available Land use planning in a remote desert zone is usually dependent on an efficient corridor and main road network system. In this paper, Geographic Information System (GIS tools were used to develop a least-cost path for a corridor to link three cities in Sinai Peninsula desert environment. It is supposed to create a backbone for developing the middle part of peninsula by facilitating the transport of mineral resources and accessibility to such region and encourage populating the remote desert city of Nekhel and the coastal cities of Taba and El Shatt. Therefore, such a route should have the least cost and should be protected from the negative impacts that may be caused by the surrounding environment. Environmental and economical factors were integrated through a spatial multicriteria model using the Analytical Hierarchy Process. Cost factors were identified and a cost surface was created for each factor, standardized, weighed and aggregated. Three visions were modelled: an engineering vision, an environmental vision and a hybrid vision. A multicriteria evaluation was used to compare the three routes. The hybrid route was finally recommended.

  8. The Vertical-Tube Solar Collector: A Low-Cost Design Suitable for Temperate High-Latitude Locations

    Directory of Open Access Journals (Sweden)

    Luis Juanicó

    2014-01-01

    Full Text Available A new low-cost solar collector based on thick (4.5′′ vertical tubes related to the previous design based on long 1.5′′ plastic hoses connected directly between water-grid supply and consumption is presented. This novel design could noticeably improve its performance for temperate locations mid and high latitudes, as was demonstrated by dynamic thermal modeling. This tool has been useful for understanding the particular characteristics of this kind of water-pond collector and besides, for noticeably improving its performance by optimizing its parameters, like tube diameter and number of glazing layers. By this way, the optimized design could fully satisfy the household demand up to midnight along the whole year for Buenos Aires (35°S and during summers (remaining as a useful preheater for the whole year for Ushuaia (55°S. Besides, its high simplicity makes it available for user’s own construction, costing down 50 dollars for a single-family unit.

  9. On the Path to SunShot - The Role of Advancements in Solar Photovoltaic Efficiency, Reliability, and Costs

    Energy Technology Data Exchange (ETDEWEB)

    Woodhouse, Michael [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jones-Albertus, Rebecca [Dept. of Energy (DOE), Washington DC (United States); Feldman, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Fu, Ran [National Renewable Energy Lab. (NREL), Golden, CO (United States); Horowitz, Kelsey [National Renewable Energy Lab. (NREL), Golden, CO (United States); Chung, Donald [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jordan, Dirk [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kurtz, Sarah [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-05-01

    Although tremendous progress has been made in reducing the cost of PV systems, additional LCOE reductions of 40%–50% between 2015 and 2020 will be required to reach the SunShot Initiative’s targets (see Woodhouse et al. 2016). Understanding the tradeoffs between installed prices and other PV system characteristics—such as module efficiency, module degradation rate, and system lifetime—are vital. For example, with 29%-efficient modules and high reliability (a 50-year lifetime and a 0.2%/year module degradation rate), a residential PV system could achieve the SunShot LCOE goal with modules priced at almost $1.20/W. But change the lifetime to 10 years and the degradation rate to 2%/year, and the system would need those very high-efficiency modules at zero cost to achieve the same LCOE. Although these examples are extreme, they serve to illustrate the wide range of technological combinations that could help drive PV toward the LCOE goals. SunShot’s PV roadmaps illustrate specific potential pathways to the target cost reductions.

  10. The Energy Cost Analysis of Hybrid Systems and Diesel Generators in Powering Selected Base Transceiver Station Locations in Nigeria

    Directory of Open Access Journals (Sweden)

    Peter Ozaveshe Oviroh

    2018-03-01

    Full Text Available As more locations gain access to telecommunication, there is a growing demand to provide energy in a reliable, efficient and environmentally friendly manner while effectively addressing growing energy needs. Erratic power supply and rising operation costs (OPEX in Nigeria have increased the need to harness local renewable energy sources. Thus, identifying the right generator schedule with the renewable system to reduce OPEX is a priority for operators and vendors. This study evaluates the energy costs of hybrid systems with different generator schedules in powering base transceiver stations in Nigeria using the Hybrid Optimization Model for Electric Renewable (HOMER. A load range of 4 kW to 8 kW was considered using: (i an optimised generator schedule; (ii forced-on generator schedule and (iii the generator-only schedule. The results showed an optimal LCOE range between averages of USD 0.156/kWh to 0.172/kWh for the 8 kW load. The percent energy contribution by generator ranges from 52.80% to 60.90%, and by the solar PV system, 39.10% to 47.20%. Excess energy ranges from 0.03% to 14.98%. The optimised generator schedule has the highest solar PV penetration of 56.8%. The OPEX savings on fuel ranges from 41.68% to 47% for the different load schedules and carbon emission savings of 4222 kg to 31,428.36 kg. The simulation results shows that powering base stations using the optimised hybrid system schedule would be a better option for the telecom industry.

  11. 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

  12. Teleconnection Paths via Climate Network Direct Link Detection.

    Science.gov (United States)

    Zhou, Dong; Gozolchiani, Avi; Ashkenazy, Yosef; Havlin, Shlomo

    2015-12-31

    Teleconnections describe remote connections (typically thousands of kilometers) of the climate system. These are of great importance in climate dynamics as they reflect the transportation of energy and climate change on global scales (like the El Niño phenomenon). Yet, the path of influence propagation between such remote regions, and weighting associated with different paths, are only partially known. Here we propose a systematic climate network approach to find and quantify the optimal paths between remotely distant interacting locations. Specifically, we separate the correlations between two grid points into direct and indirect components, where the optimal path is found based on a minimal total cost function of the direct links. We demonstrate our method using near surface air temperature reanalysis data, on identifying cross-latitude teleconnections and their corresponding optimal paths. The proposed method may be used to quantify and improve our understanding regarding the emergence of climate patterns on global scales.

  13. GIS-based approach for defining bioenergy facilities location: A case study in Northern Spain based on marginal delivery costs and resources competition between facilities

    Energy Technology Data Exchange (ETDEWEB)

    Panichelli, Luis; Gnansounou, Edgard [Laboratory of Energy Systems, Swiss Federal Institute of Technology, LASEN-ICARE-ENAC, Station 18, EPFL, CH-1015 Lausanne (Switzerland)

    2008-04-15

    This paper presents a GIS-based decision support system for selecting least-cost bioenergy locations when there is a significant variability in biomass farmgate price and when more than one bioenergy plant with a fixed capacity has to be placed in the region. The methodology tackles the resources competition problem between energy facilities through a location-allocation model based on least-cost biomass quantities. Whole system least delivery cost including intermediate bioenergy products is estimated. The methodology is based on a case study where forest wood residues (FWR) from final cuttings (FCs) are used to produce torrefied wood (TW) in two torrefaction plants (TUs) that supply a gasification unit (GU) in order to produce electricity. The provinces of Navarra, Bizkaia, Gipuzkoa, Alava, La Rioja, Cantabria and Burgos are assessed in order to find the best locations for settling down the TUs and the GU according to biomass availability, FWR and TW marginal delivery costs. (author)

  14. Performance Evaluation of AODV, DSR, DYMO & ZRP in Cost 231 Walfisch-Ikegami Path Loss Propagation Model

    Directory of Open Access Journals (Sweden)

    Rachit JAIN

    2011-07-01

    Full Text Available A Mobile Ad hoc NETwork is a kind of wireless ad-hoc network, and is a self configuring network of mobile routers connected by wireless links. Mobile Ad-Hoc Network (MANET is a wireless network without infrastructure. Self configurability and easy deployment feature of the MANET resulted in numerous applications in this modern era. Efficient routing protocols will make MANETs reliable. Various research communities are working in field of MANET and trying to adopt the protocols and technology in other applications as well. In this work, we present investigations on the behavior of various routing protocol of MANET with a Cost 231 Walfisch-Ikegami Propagation Model. We evaluate the performance of four different ad-hoc routing protocols on four performance metrics such as Average Jitter, Average End-to-End Delay, Throughput, and Packet Delivery Fraction with varying Pause Time. From the simulation results it is concluded that DSR is better in transmission of packets per unit time and maximum number of packets reached their destination successfully with some delays, i.e. PDF & Throughput is more and Average jitter & end-to-end delay is less. Whereas AODV & ZRP having almost same values in all of the performance metrics, they transmit packets with very less delay but transmits less packets to their destination as compare to DSR

  15. Video distribution system cost model

    Science.gov (United States)

    Gershkoff, I.; Haspert, J. K.; Morgenstern, B.

    1980-01-01

    A cost model that can be used to systematically identify the costs of procuring and operating satellite linked communications systems is described. The user defines a network configuration by specifying the location of each participating site, the interconnection requirements, and the transmission paths available for the uplink (studio to satellite), downlink (satellite to audience), and voice talkback (between audience and studio) segments of the network. The model uses this information to calculate the least expensive signal distribution path for each participating site. Cost estimates are broken downy by capital, installation, lease, operations and maintenance. The design of the model permits flexibility in specifying network and cost structure.

  16. 41 CFR 301-70.505 - May any travel costs be reimbursed if the employee travels to an alternate location for medical...

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 4 2010-07-01 2010-07-01 false May any travel costs be reimbursed if the employee travels to an alternate location for medical treatment? 301-70.505 Section 301-70.505 Public Contracts and Property Management Federal Travel Regulation System TEMPORARY DUTY (TDY) TRAVEL ALLOWANCES AGENCY RESPONSIBILITIES...

  17. 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...

  18. Analysis of cost estimation and wind energy evaluation using wind energy conversion systems (WECS) for electricity generation in six selected high altitude locations in Nigeria

    International Nuclear Information System (INIS)

    Ohunakin, S. Olayinka; Ojolo, S. Joshua; Ogunsina, S. Babatunde; Dinrifo, R. Rufus

    2012-01-01

    Two commercial wind turbines namely AN Bonus 300 kW/33 and AN Bonus 1 MW/54 were technically assessed for electricity generation in six selected high altitude sites spreading across the North-West and North-East geopolitical regions of Nigeria by computing their capacity factors, annual power and energy outputs. The economic evaluation of using the two wind energy conversion systems (medium and large) for electric power generation in the selected locations were also estimated using the present value cost method. The results showed that capacity factors of the two turbines in the selected sites ranged between 4.6 and 43%. Average minimum cost per kW h was obtained in Kano as $0.0222/kW h with AN Bonus 1 MW while the highest average cost is $0.2074/kW h with AN Bonus 300 kW in Kaduna. The highest cost in each of the location was obtained with the medium WECs (AN Bonus 300 kW). In addition, Kano and Katsina were also found to be very economical for any of the adopted wind turbine models. Gusau and Kaduna, at cost of unit energy of about $0.30/kW h were found to be more profitable for non-connected electrical and mechanical applications (water pumping, battery charging) than diesel generator. - Highlights: ► All the locations considered have mean wind speeds above 4.8 m/s. ► Economical wind applications are possible in Kano and Katsina. ► Highest capacity factor and energy output are obtained using AN Bonus 1 MW in Kano. ► Specific cost of unit energy per kW h is cheaper using AN Bonus 1 MW.

  19. Understanding the costs and benefits of land development : An empirical analysis into the financial effects of location features

    NARCIS (Netherlands)

    Buitelaar, E.; Witte, P.A.; Spit, T.J.M.

    2012-01-01

    As a means to sustainable urban development, redeveloping brownfield sites is advocated over greenfield development in most Western countries. There is much case study research into the factors that influence the (financial) costs, revenues and results of land development. What is virtually absent

  20. 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...

  1. Cost analysis of teg-powered and solar-powered cathodic protection system for a-50 km long buried natural gas pipeline located in Sindh, Pakistan

    International Nuclear Information System (INIS)

    Shahid, M.; Inam, F.; Farooq, M.; Khan, F.N.

    2005-01-01

    Corrosion leaks are of significant concern to oil and gas industry and is considered to be the largest controllable factor in pipeline safety. Cathodic Protection (CP) is a well-established method for preventing corrosion of metallic materials. Electrical power is required and it is usually difficult and expensive to install conventional power lines in remote areas for readily available power supply. Oil/gas organizations make use of thermo-electric generators (TEG), which is relatively expensive in terms of running expenditures. Utilization of renewable energies is now being widely explored due to potential danger of running out of natural resources and dates back mid of 20th century [I]. However, use of solar powered CP system for oil/gas pipelines hasn't been encouraged much in Pakistan, probably due to lack of understanding. A project was undertaken for designing a solar powered CP system for a 52.4 km buried gas pipeline located at Sui/Sara gas fields (Latitude 27.5) of Tullow Pakistan (Dev.) Ltd. in Dharki, Sindh, Pakistan. After detailed analysis of soil condition, electrochemical testing, local climatic variation and cost analysis, it has been revealed that use of solar power is quite feasible for the above-mentioned pipeline section. Cost analysis and comparison have also favored this system since the maintenance cost of the solar-powered system is much less compared to TEG system. Installation cost of the solar system is about 1.57 times the cost of TEG; however, the maintenance cost is only -20% of that for TEG system. The higher installation cost has been estimated to be recoverable in less than one year of service. (author)

  2. Determining Methane Leak Locations and Rates with a Wireless Network Composed of Low-Cost, Printed Sensors

    Science.gov (United States)

    Smith, C. J.; Kim, B.; Zhang, Y.; Ng, T. N.; Beck, V.; Ganguli, A.; Saha, B.; Daniel, G.; Lee, J.; Whiting, G.; Meyyappan, M.; Schwartz, D. E.

    2015-12-01

    We will present our progress on the development of a wireless sensor network that will determine the source and rate of detected methane leaks. The targeted leak detection threshold is 2 g/min with a rate estimation error of 20% and localization error of 1 m within an outdoor area of 100 m2. The network itself is composed of low-cost, high-performance sensor nodes based on printed nanomaterials with expected sensitivity below 1 ppmv methane. High sensitivity to methane is achieved by modifying high surface-area-to-volume-ratio single-walled carbon nanotubes (SWNTs) with materials that adsorb methane molecules. Because the modified SWNTs are not perfectly selective to methane, the sensor nodes contain arrays of variously-modified SWNTs to build diversity of response towards gases with adsorption affinity. Methane selectivity is achieved through advanced pattern-matching algorithms of the array's ensemble response. The system is low power and designed to operate for a year on a single small battery. The SWNT sensing elements consume only microwatts. The largest power consumer is the wireless communication, which provides robust, real-time measurement data. Methane leak localization and rate estimation will be performed by machine-learning algorithms built with the aid of computational fluid dynamics simulations of gas plume formation. This sensor system can be broadly applied at gas wells, distribution systems, refineries, and other downstream facilities. It also can be utilized for industrial and residential safety applications, and adapted to other gases and gas combinations.

  3. 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.

  4. Opportunities for co-location of solar PV with agriculture for cost reductions and carbon, water, and energy footprint mitigation in the tropics

    Science.gov (United States)

    Choi, C. S.; Macknick, J.; Ravi, S.

    2017-12-01

    Recently, co-locating the production of agricultural crops or biofuels with solar photovoltaics (PV) installations has been studied as a possible strategy to mitigate the environmental impacts and the high cost of solar PV in arid and semi-arid regions. Co-located PV and agricultural systems can provide multiple benefits in these areas related to water savings, erosion control, energy access, and rural economic development. However, such studies have been rare for water-rich, land-limited tropical countries, where ideal agricultural growing conditions can be substantially different from those in arid regions. We consider a case study in Indonesia to address this research gap. As the fourth most populous nation with an ever-growing energy demand and high vulnerability to the effects of climate change, Indonesia is being prompted to develop means to electrify approximately one-fifth of its population that still lacks access to the grid without incurring increases in its carbon footprint. We address the following questions to explore the feasibility and the benefits of co-location of solar PV with patchouli cultivation and essential oil production: i) How do the lifetime carbon, water, and energy footprints per unit land area of co-located solar PV/patchouli compare to those of standalone diesel microgrid, solar PV or patchouli cultivation? ii) Does energy production from standalone solar PV, diesel/solar PV microgrid, or co-located solar PV/patchouli systems satisfy energy demands of a typical rural Indonesian village? iii) How does the net economic return of the co-located system compare to each standalone land use? iv) How can surplus energy from the co-located system benefit rural socioeconomics? To answer these questions, life cycle assessment and economic analysis are performed for each of the standalone and the co-located land uses utilizing known values and data collected from a field visit to the island of Java in Indonesia. Then, sensitivity analyses and

  5. The effect of handover location on trauma theatre start time: An estimated cost saving of £131 000 per year.

    Science.gov (United States)

    Nahas, Sam; Ali, Adam; Majid, Kiran; Joseph, Roshan; Huber, Chris; Babu, Victor

    2018-02-08

    The National Health Service was estimated to be in £2.45 billion deficit in 2015 to 2016. Trauma theatre utilization and efficiency has never been so important as it is estimated to cost £15/minute. Structured questionnaires were given to 23 members of staff at our Trust who are actively involved in the organization or delivery of orthopaedic trauma lists at least once per week. This was used to identify key factors that may improve theatre efficiency. Following focus group evaluation, the location of the preoperative theatre meeting was changed, with all staff involved being required to attend this. Our primary outcome measure was mean theatre start time (time of arrival in the anaesthetic room) during the 1 month immediately preceding the change and the month following the change. Theatre start time was improved on average 24 minutes (1 month premeeting and postmeeting change). This equates to a saving of £360 per day, or £131 040 per year. Changing the trauma meeting location to a venue adjacent to the trauma theatre can improve theatre start times, theatre efficiency, and therefore result in significant cost savings. Copyright © 2018 John Wiley & Sons, Ltd.

  6. 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.

  7. Appraising manufacturing location

    NARCIS (Netherlands)

    Steenhuis, H.J.; de Bruijn, E.J.

    2002-01-01

    International location of manufacturing activities is an issue for managers of manufacturing companies as well as public policy makers. For managers, the issue is relevant because international locations offer opportunities for lowering costs due to productivity improvements. For governments the

  8. 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...

  9. 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)

  10. 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.

  11. 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

  12. Construction of Time-Stamped Mobility Map for Path Tracking via Smith-Waterman Measurement Matching

    Directory of Open Access Journals (Sweden)

    Mu Zhou

    2014-01-01

    Full Text Available Path tracking in wireless and mobile environments is a fundamental technology for ubiquitous location-based services (LBSs. In particular, it is very challenging to develop highly accurate and cost-efficient tracking systems applied to the anonymous areas where the floor plans are not available for security and privacy reasons. This paper proposes a novel path tracking approach for large Wi-Fi areas based on the time-stamped unlabeled mobility map which is constructed from Smith-Waterman received signal strength (RSS measurement matching. Instead of conventional location fingerprinting, we construct mobility map with the technique of dimension reduction from the raw measurement space into a low-dimensional embedded manifold. The feasibility of our proposed approach is verified by the real-world experiments in the HKUST campus Wi-Fi networks, sMobileNet. The experimental results prove that our approach is adaptive and capable of achieving an adequate precision level in path tracking.

  13. Multiobjective Location Routing Problem considering Uncertain Data after Disasters

    Directory of Open Access Journals (Sweden)

    Keliang Chang

    2017-01-01

    Full Text Available The relief distributions after large disasters play an important role for rescue works. After disasters there is a high degree of uncertainty, such as the demands of disaster points and the damage of paths. The demands of affected points and the velocities between two points on the paths are uncertain in this article, and the robust optimization method is applied to deal with the uncertain parameters. This paper proposes a nonlinear location routing problem with half-time windows and with three objectives. The affected points can be visited more than one time. The goals are the total costs of the transportation, the satisfaction rates of disaster nodes, and the path transport capacities which are denoted by vehicle velocities. Finally, the genetic algorithm is applied to solve a number of numerical examples, and the results show that the genetic algorithm is very stable and effective for this problem.

  14. Optimal path-finding through mental exploration based on neural energy field gradients.

    Science.gov (United States)

    Wang, Yihong; Wang, Rubin; Zhu, Yating

    2017-02-01

    Rodent animal can accomplish self-locating and path-finding task by forming a cognitive map in the hippocampus representing the environment. In the classical model of the cognitive map, the system (artificial animal) needs large amounts of physical exploration to study spatial environment to solve path-finding problems, which costs too much time and energy. Although Hopfield's mental exploration model makes up for the deficiency mentioned above, the path is still not efficient enough. Moreover, his model mainly focused on the artificial neural network, and clear physiological meanings has not been addressed. In this work, based on the concept of mental exploration, neural energy coding theory has been applied to the novel calculation model to solve the path-finding problem. Energy field is constructed on the basis of the firing power of place cell clusters, and the energy field gradient can be used in mental exploration to solve path-finding problems. The study shows that the new mental exploration model can efficiently find the optimal path, and present the learning process with biophysical meaning as well. We also analyzed the parameters of the model which affect the path efficiency. This new idea verifies the importance of place cell and synapse in spatial memory and proves that energy coding is effective to study cognitive activities. This may provide the theoretical basis for the neural dynamics mechanism of spatial memory.

  15. Special cases of the quadratic shortest path problem

    NARCIS (Netherlands)

    Sotirov, Renata; Hu, Hao

    2017-01-01

    The quadratic shortest path problem (QSPP) is the problem of finding a path with prespecified start vertex s and end vertex t in a digraph such that the sum of weights of arcs and the sum of interaction costs over all pairs of arcs on the path is minimized. We first consider a variant of the QSPP

  16. 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...

  17. 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.

  18. How much does it cost to get a dose of vaccine to the service delivery location? Empirical evidence from Vietnam's Expanded Program on Immunization.

    Science.gov (United States)

    Mvundura, Mercy; Kien, Vu Duy; Nga, Nguyen Tuyet; Robertson, Joanie; Cuong, Nguyen Van; Tung, Ho Thanh; Hong, Duong Thi; Levin, Carol

    2014-02-07

    Few studies document the costs of operating vaccine supply chains, but decision-makers need this information to inform cost projections for investments to accommodate new vaccine introduction. This paper presents empirical estimates of vaccine supply chain costs for Vietnam's Expanded Program on Immunization (EPI) for routine vaccines at each level of the supply chain, before and after the introduction of the pentavalent vaccine. We used micro-costing methods to collect resource-use data associated with storage and transportation of vaccines and immunization supplies at the national store, the four regional stores, and a sample of provinces, districts, and commune health centers. We collected stock ledger data on the total number of doses of vaccines handled by each facility during the assessment year. Total supply chain costs were estimated at approximately US$65,000 at the national store and an average of US$39,000 per region, US$5800 per province, US$2200 per district, and US$300 per commune health center. Across all levels, cold chain equipment capital costs and labor were the largest drivers of costs. The cost per dose delivered was estimated at US$0.19 before the introduction of pentavalent and US$0.24 cents after introduction. At commune health centers, supply chain costs were 104% of the value of vaccines before introduction of pentavalent vaccine and 24% after introduction, mainly due to the higher price per dose of the pentavalent vaccine. The aggregated costs at the last tier of the health system can be substantial because of the large number of facilities. Even in countries with high-functioning systems, empirical evidence on current costs from all levels of the system can help estimate resource requirements for expanding and strengthening resources to meet future immunization program needs. Other low- and middle-income countries can benefit from similar studies, in view of new vaccine introductions that will put strains on existing systems. Copyright

  19. Locative media

    CERN Document Server

    Wilken, Rowan

    2014-01-01

    Not only is locative media one of the fastest growing areas in digital technology, but questions of location and location-awareness are increasingly central to our contemporary engagements with online and mobile media, and indeed media and culture generally. This volume is a comprehensive account of the various location-based technologies, services, applications, and cultures, as media, with an aim to identify, inventory, explore, and critique their cultural, economic, political, social, and policy dimensions internationally. In particular, the collection is organized around the perception that the growth of locative media gives rise to a number of crucial questions concerning the areas of culture, economy, and policy.

  20. Optimization of educational paths for higher education

    Science.gov (United States)

    Tarasyev, Alexandr A.; Agarkov, Gavriil; Medvedev, Aleksandr

    2017-11-01

    In our research, we combine the theory of economic behavior and the methodology of increasing efficiency of the human capital to estimate the optimal educational paths. We provide an optimization model for higher education process to analyze possible educational paths for each rational individual. The preferences of each rational individual are compared to the best economically possible educational path. The main factor of the individual choice, which is formed by the formation of optimal educational path, deals with higher salaries level in the chosen economic sector after graduation. Another factor that influences on the economic profit is the reduction of educational costs or the possibility of the budget support for the student. The main outcome of this research consists in correction of the governmental policy of investment in human capital based on the results of educational paths optimal control.

  1. Location, location, location: Extracting location value from house prices

    OpenAIRE

    Kolbe, Jens; Schulz, Rainer; Wersing, Martin; Werwatz, Axel

    2012-01-01

    The price for a single-family house depends both on the characteristics of the building and on its location. We propose a novel semiparametric method to extract location values from house prices. After splitting house prices into building and land components, location values are estimated with adaptive weight smoothing. The adaptive estimator requires neither strong smoothness assumptions nor local symmetry. We apply the method to house transactions from Berlin, Germany. The estimated surface...

  2. The effect of solar and lunar currents on simultaneous phase path, group path and amplitude measurements

    International Nuclear Information System (INIS)

    Baulch, R.N.E.; Butcher, E.C.

    1984-01-01

    The solar and lunar variations in the phase path, group path and amplitude of a fixed frequency transmission were obtained at the September equinox over a slightly oblique path. The phase of the lunar semi-diurnal tide in the phase path and amplitude were similar, the maxima occurring near 0200 lunar time, whereas the group path had a maximum near 0800 lunar time. These results were compared with other results obtained near the same location. The results suggest a complex situation in the E-region, where the height of the lunar current depends on season, and also suggest that the location and distribution of the solar and lunar currents may be different. (author)

  3. 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

  4. Unusual bond paths in organolithium compounds

    International Nuclear Information System (INIS)

    Bachrach, S.M.; Ritchie, J.P.

    1986-01-01

    We have applied the topological method to a number of organolithium compounds. The wavefunctions were determined with GAUSSIAN-82 using 3-21G basis set and fully optimized geometries. Gradient paths were obtained using the RHODER package and critical points were located using EXTREME. These results indicate the unusual nature of organolithium compounds. The strange bond paths arise mainly from the ionic nature of the C-Li interaction. We suggest that the term ''bond path'' may best be suited for covalent bonds. 4 figs., 1 tab

  5. 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)

  6. 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.

  7. 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.

  8. 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.

  9. Time path of marginal cost for measures against global warming toward the greenhouse gas concentration target. Analytic solution and case study of the electric power sector; Onshitsu koka gas nodo mokuhyoka deno ondanka taisaku genkai hiyo no jikan keiro. Kaisekikai to denryoku bumon no case study

    Energy Technology Data Exchange (ETDEWEB)

    Nagano, K.; Sugiyama, H.; Takahashi, M. [Central Research Institute of Electric Power Industry, Tokyo (Japan)

    1997-01-30

    The United Nations Framework Convention on Climate Change is studied from the viewpoint of implementing costs. As far as the global warming issue is concerned, the factor to affect the environment is not the emitted volume but the concentration in the air. The ultimate target is the stabilization of greenhouse gas concentration at a level not to impose serious artificial damage on the ecosystem. Accordingly, various time paths are considered, including one in which much emission is allowed at the beginning and suppression is enforced acceleratedly in the later stage. In this study, a path demanding but the minimal cost in the period up to the target time point is discussed, using as the tool the marginal cost for measure implementation. In a reasonable emission control strategy, the emission control marginal cost follows a time path that is dependent upon an increase function to be determined by the discount rate and survival rate (time constant) in the atmosphere. In the industrial branch, instead of imposing short-term and rigid emission volume control limits, a longer-term target may be set for reduction in the loads responsible for concentration acceleration, concrete emission controls under the given conditions may be implemented at the discretion of the implementing organizations, and reduction in cost may be realized by time distribution with the environmental impacts kept at approximately equal levels. 5 refs., 2 figs., 3 tabs.

  10. 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...

  11. 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....

  12. 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

  13. Library Locations

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Carnegie Library of Pittsburgh locations including address, coordinates, phone number, square footage, and standard operating hours. The map below does not display...

  14. Optimal Path Determination for Flying Vehicle to Search an Object

    Science.gov (United States)

    Heru Tjahjana, R.; Heri Soelistyo U, R.; Ratnasari, L.; Irawanto, B.

    2018-01-01

    In this paper, a method to determine optimal path for flying vehicle to search an object is proposed. Background of the paper is controlling air vehicle to search an object. Optimal path determination is one of the most popular problem in optimization. This paper describe model of control design for a flying vehicle to search an object, and focus on the optimal path that used to search an object. In this paper, optimal control model is used to control flying vehicle to make the vehicle move in optimal path. If the vehicle move in optimal path, then the path to reach the searched object also optimal. The cost Functional is one of the most important things in optimal control design, in this paper the cost functional make the air vehicle can move as soon as possible to reach the object. The axis reference of flying vehicle uses N-E-D (North-East-Down) coordinate system. The result of this paper are the theorems which say that the cost functional make the control optimal and make the vehicle move in optimal path are proved analytically. The other result of this paper also shows the cost functional which used is convex. The convexity of the cost functional is use for guarantee the existence of optimal control. This paper also expose some simulations to show an optimal path for flying vehicle to search an object. The optimization method which used to find the optimal control and optimal path vehicle in this paper is Pontryagin Minimum Principle.

  15. Charting a Path to Location Intelligence for STD Control

    OpenAIRE

    Gerber, Todd M.; Du, Ping; Armstrong-Brown, Janelle; McNutt, Louise-Anne; Coles, F. Bruce

    2009-01-01

    This article describes the New York State Department of Health's GeoDatabase project, which developed new methods and techniques for designing and building a geocoding and mapping data repository for sexually transmitted disease (STD) control. The GeoDatabase development was supported through the Centers for Disease Control and Prevention's Outcome Assessment through Systems of Integrated Surveillance workgroup. The design and operation of the GeoDatabase relied upon commercial-off-the-shelf ...

  16. Gene Locater

    DEFF Research Database (Denmark)

    Anwar, Muhammad Zohaib; Sehar, Anoosha; Rehman, Inayat-Ur

    2012-01-01

    software's for calculating recombination frequency is mostly limited to the range and flexibility of this type of analysis. GENE LOCATER is a fully customizable program for calculating recombination frequency, written in JAVA. Through an easy-to-use interface, GENE LOCATOR allows users a high degree...... of flexibility in calculating genetic linkage and displaying linkage group. Among other features, this software enables user to identify linkage groups with output visualized graphically. The program calculates interference and coefficient of coincidence with elevated accuracy in sample datasets. AVAILABILITY...

  17. 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.)

  18. 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

  19. 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

  20. 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

  1. Spatial interpolation of fine particulate matter concentrations using the shortest wind-field path distance.

    Directory of Open Access Journals (Sweden)

    Longxiang Li

    Full Text Available Effective assessments of air-pollution exposure depend on the ability to accurately predict pollutant concentrations at unmonitored locations, which can be achieved through spatial interpolation. However, most interpolation approaches currently in use are based on the Euclidean distance, which cannot account for the complex nonlinear features displayed by air-pollution distributions in the wind-field. In this study, an interpolation method based on the shortest path distance is developed to characterize the impact of complex urban wind-field on the distribution of the particulate matter concentration. In this method, the wind-field is incorporated by first interpolating the observed wind-field from a meteorological-station network, then using this continuous wind-field to construct a cost surface based on Gaussian dispersion model and calculating the shortest wind-field path distances between locations, and finally replacing the Euclidean distances typically used in Inverse Distance Weighting (IDW with the shortest wind-field path distances. This proposed methodology is used to generate daily and hourly estimation surfaces for the particulate matter concentration in the urban area of Beijing in May 2013. This study demonstrates that wind-fields can be incorporated into an interpolation framework using the shortest wind-field path distance, which leads to a remarkable improvement in both the prediction accuracy and the visual reproduction of the wind-flow effect, both of which are of great importance for the assessment of the effects of pollutants on human health.

  2. A Location-Based Duplex Scheme for Cost Effective Rural Broadband Connectivity Using IEEE 802.22 Cognitive Radio Based Wireless Regional Area Networks

    Science.gov (United States)

    Kalidoss, R.; Bhagyaveni, M. A.; Vishvaksenan, K. S.

    2014-08-01

    The search for a method of utilizing the scarce spectrum in an efficient manner is an active area of research in both academic and industrial communities. IEEE 802.22 is a standard for wireless regional area network (WRAN) based on cognitive radio (CR) that operates over underutilized portions of TV bands (54-862 MHz). Time division duplex (TDD)-based WRAN cells have such advantages as dynamic traffic allocation, traffic asymmetry to users and ease of spectrum allocation. However, these cells suffer from severe cross time slot (CTS) interference when the frames of the cells are not synchronized with adjacent WRAN cells. In this paper, we evaluate the location-based duplex (LBD) scheme for eliminating the CTS interference. The proposed LBD system is much more flexible and efficient in providing asymmetric data service and eliminating CTS interference by exploiting the advantages of both TDD and frequency division duplex (FDD) schemes. We also compare the performance of LBD systems with virtual cell concepts. Furthermore, our simulation results reveal that LBD-based systems outperform the virtual cell approach in terms of the low signal-to-interference (SIR) ratio requirement by mitigating the effects of CTS.

  3. 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.

  4. 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.

  5. 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...

  6. 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

  7. 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...

  8. 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

  9. Tuning of Lee Path Loss Model based on recent RF measurements in 400 MHZ conducted in Riyadh City, Saudi Arabia

    International Nuclear Information System (INIS)

    Alotaibi, Faihan D.; Ali, Adel A.

    2008-01-01

    In mobile radio systems, path loss models are necessary for proper planning, interference estimations, frequently assignments and cell parameters which are basic for network planning process as well as Location Based Services (LBS) techniques that are not based on GPS system. Empirical models are the most adjustable models that can be suited to different types of environments. In this paper, the Lee path loss model has been tuned using Least Square (LS) algorithm to fit measured data for TETRA system operating 400 MHz in Riyadh urban and suburbs. Consequently, Lee model's parameter (L0, y) are obtained for the targeted areas. The performance of the tuned Lee model is then compared to the three most widely used empirical path loss models: Hat, ITU-R and Cost 231 Walfisch-Ikegami non line-of-sight (CWI-NLOS) path loss models. The performance criterion selected for the comparison of various empirical path loss models are the Root Mean Square Error (RMSE) and goodness of fit (R2). The RMSE and R2between the actual and predicted data are calculated for various path loss models. It turned that the tuned Lee model outperforms the other empirical models. (author)

  10. 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.

  11. 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

  12. Remembered landmarks enhance the precision of path integration

    Directory of Open Access Journals (Sweden)

    Shannon O´Leary

    2005-01-01

    Full Text Available When navigating by path integration, knowledge of one’s position becomes increasingly uncertain as one walks from a known location. This uncertainty decreases if one perceives a known landmark location nearby. We hypothesized that remembering landmarks might serve a similar purpose for path integration as directly perceiving them. If this is true, walking near a remembered landmark location should enhance response consistency in path integration tasks. To test this, we asked participants to view a target and then attempt to walk to it without vision. Some participants saw the target plus a landmark during the preview. Compared with no-landmark trials, response consistency nearly doubled when participants passed near the remembered landmark location. Similar results were obtained when participants could audibly perceive the landmark while walking. A control experiment ruled out perceptual context effects during the preview. We conclude that remembered landmarks can enhance path integration even though they are not directly perceived.

  13. 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

  14. Variational nature, integration, and properties of Newton reaction path.

    Science.gov (United States)

    Bofill, Josep Maria; Quapp, Wolfgang

    2011-02-21

    The distinguished coordinate path and the reduced gradient following path or its equivalent formulation, the Newton trajectory, are analyzed and unified using the theory of calculus of variations. It is shown that their minimum character is related to the fact that the curve is located in a valley region. In this case, we say that the Newton trajectory is a reaction path with the category of minimum energy path. In addition to these findings a Runge-Kutta-Fehlberg algorithm to integrate these curves is also proposed.

  15. Variational nature, integration, and properties of Newton reaction path

    Science.gov (United States)

    Bofill, Josep Maria; Quapp, Wolfgang

    2011-02-01

    The distinguished coordinate path and the reduced gradient following path or its equivalent formulation, the Newton trajectory, are analyzed and unified using the theory of calculus of variations. It is shown that their minimum character is related to the fact that the curve is located in a valley region. In this case, we say that the Newton trajectory is a reaction path with the category of minimum energy path. In addition to these findings a Runge-Kutta-Fehlberg algorithm to integrate these curves is also proposed.

  16. Approximate Shortest Homotopic Paths in Weighted Regions

    KAUST Repository

    Cheng, Siu-Wing

    2010-01-01

    Let P be a path between two points s and t in a polygonal subdivision T with obstacles and weighted regions. Given a relative error tolerance ε ∈(0,1), we present the first algorithm to compute a path between s and t that can be deformed to P without passing over any obstacle and the path cost is within a factor 1 + ε of the optimum. The running time is O(h 3/ε2 kn polylog(k, n, 1/ε)), where k is the number of segments in P and h and n are the numbers of obstacles and vertices in T, respectively. The constant in the running time of our algorithm depends on some geometric parameters and the ratio of the maximum region weight to the minimum region weight. © 2010 Springer-Verlag.

  17. Approximate shortest homotopic paths in weighted regions

    KAUST Repository

    Cheng, Siuwing

    2012-02-01

    A path P between two points s and t in a polygonal subdivision T with obstacles and weighted regions defines a class of paths that can be deformed to P without passing over any obstacle. We present the first algorithm that, given P and a relative error tolerance ε (0, 1), computes a path from this class with cost at most 1 + ε times the optimum. The running time is O(h 3/ε 2kn polylog (k,n,1/ε)), where k is the number of segments in P and h and n are the numbers of obstacles and vertices in T, respectively. The constant in the running time of our algorithm depends on some geometric parameters and the ratio of the maximum region weight to the minimum region weight. © 2012 World Scientific Publishing Company.

  18. Paths of movement

    DEFF Research Database (Denmark)

    Hansen, Lone Koefoed

    2013-01-01

    )stories of both “nomad” and location, factual data is transformed into narrative potential. When location data is layered with everyday life, spatial narratives emerge. This chapter analyzes the artistic practice of Dutch media artist Esther Polak, who demonstrates how location data can be brought to life...

  19. Which coordinate system for modelling path integration?

    Science.gov (United States)

    Vickerstaff, Robert J; Cheung, Allen

    2010-03-21

    Path integration is a navigation strategy widely observed in nature where an animal maintains a running estimate, called the home vector, of its location during an excursion. Evidence suggests it is both ancient and ubiquitous in nature, and has been studied for over a century. In that time, canonical and neural network models have flourished, based on a wide range of assumptions, justifications and supporting data. Despite the importance of the phenomenon, consensus and unifying principles appear lacking. A fundamental issue is the neural representation of space needed for biological path integration. This paper presents a scheme to classify path integration systems on the basis of the way the home vector records and updates the spatial relationship between the animal and its home location. Four extended classes of coordinate systems are used to unify and review both canonical and neural network models of path integration, from the arthropod and mammalian literature. This scheme demonstrates analytical equivalence between models which may otherwise appear unrelated, and distinguishes between models which may superficially appear similar. A thorough analysis is carried out of the equational forms of important facets of path integration including updating, steering, searching and systematic errors, using each of the four coordinate systems. The type of available directional cue, namely allothetic or idiothetic, is also considered. It is shown that on balance, the class of home vectors which includes the geocentric Cartesian coordinate system, appears to be the most robust for biological systems. A key conclusion is that deducing computational structure from behavioural data alone will be difficult or impossible, at least in the absence of an analysis of random errors. Consequently it is likely that further theoretical insights into path integration will require an in-depth study of the effect of noise on the four classes of home vectors. Copyright 2009 Elsevier Ltd

  20. 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.

  1. Analysis Of Economic Motivation When Individuals Choose An Educational Path

    Directory of Open Access Journals (Sweden)

    Viktor Anatolyevich Koksharov

    2015-03-01

    Full Text Available The authors consider the economic motivations when individuals choose an educational path. This line of research is relevant from both, the point of view of science — research of economic behavior of an individual, and the point of view of practice — allows to increase efficiency of investments in a human capital. The authors have developed the economic and mathematical model of choice of optimum educational paths by individuals. The model is realized in the software and approved on real data on more than 5,5 thousand students. For the analysis of the importance of rational economic expectations when an educational path has to be chosen, the paths chosen by students is compared and the educational paths optimum from the point of view of economic rationality are calculated. The analysis of the results has showed that mainly, the choice of educational paths happens according to the economic motivations. On the considered selection, 66 % of prospective students have chosen an optimum path from the point of view of economic preferences. The most significant factor providing development of optimum educational paths is an expectation of higher income upon completion of education — 22 % of all educational paths, and a possibility of cost-cutting of educating or state-subsidized education — 12 %. In our opinion, one of the most important practical results of the research of optimum educational path is the need to consider expectations of students and prospective student when developing a state policy of investment in human capital.

  2. 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.

  3. 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....

  4. Path dependence and independent utility regulation

    DEFF Research Database (Denmark)

    Ibsen, Christian Lyhne; Skovgaard Poulsen, Lauge

    2007-01-01

    The establishment of the Danish independent regulatory authorities for the energy and telecommunications sectors was based upon EU directives as part of their liberalisation process. Following the concepts of transaction costs and path dependency this article analyses differences in independence...... between the two authorities - the Danish Energy Regulatory Authority (Energitilsynet) and the National IT and Telecommunications Agency (IT- og Telestyrelsen) respectively. We find that the state's negligible interest in the energy sector until the 1970s formed the basis for strong energy companies...

  5. Using step and path selection functions for estimating resistance to movement: Pumas as a case study

    Science.gov (United States)

    Katherine A. Zeller; Kevin McGarigal; Samuel A. Cushman; Paul Beier; T. Winston Vickers; Walter M. Boyce

    2015-01-01

    GPS telemetry collars and their ability to acquire accurate and consistently frequent locations have increased the use of step selection functions (SSFs) and path selection functions (PathSFs) for studying animal movement and estimating resistance. However, previously published SSFs and PathSFs often do not accommodate multiple scales or multiscale modeling....

  6. 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.

  7. 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.

  8. 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

  9. 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...

  10. Location Systems An Introduction to the Technology Behind Location Awareness

    CERN Document Server

    LaMarca, Anthony

    2008-01-01

    Advances in electronic location technology and the coming of age of mobile computing have opened the door for location-aware applications to permeate all aspects of everyday life. Location is at the core of a large number of high-value applications ranging from the life-and-death context of emergency response to serendipitous social meet-ups. For example, the market for GPS products and services alone is expected to grow to US200 billion by 2015. Unfortunately, there is no single location technology that is good for every situation and exhibits high accuracy, low cost, and universal coverage.

  11. Piloting and Path Integration within and across Boundaries

    Science.gov (United States)

    Mou, Weimin; Wang, Lin

    2015-01-01

    Three experiments investigated whether navigation is less efficient across boundaries than within boundaries. In an immersive virtual environment, participants learned objects' locations in a large room or a small room. Participants then pointed to the objects' original locations after physically walking a circuitous path without vision.…

  12. RFID Location Algorithm

    Directory of Open Access Journals (Sweden)

    Wang Zi Min

    2016-01-01

    Full Text Available With the development of social services, people’s living standards improve further requirements, there is an urgent need for a way to adapt to the complex situation of the new positioning technology. In recent years, RFID technology have a wide range of applications in all aspects of life and production, such as logistics tracking, car alarm, security and other items. The use of RFID technology to locate, it is a new direction in the eyes of the various research institutions and scholars. RFID positioning technology system stability, the error is small and low-cost advantages of its location algorithm is the focus of this study.This article analyzes the layers of RFID technology targeting methods and algorithms. First, RFID common several basic methods are introduced; Secondly, higher accuracy to political network location method; Finally, LANDMARC algorithm will be described. Through this it can be seen that advanced and efficient algorithms play an important role in increasing RFID positioning accuracy aspects.Finally, the algorithm of RFID location technology are summarized, pointing out the deficiencies in the algorithm, and put forward a follow-up study of the requirements, the vision of a better future RFID positioning technology.

  13. Continuous in-situ methane measurements at paddy fields in a rural area of India with poor electric infrastructure, using a low-cost instrument based on open-path near-IR laser absorption spectroscopy

    Science.gov (United States)

    Hidemori, T.; Matsumi, Y.; Nakayama, T.; Kawasaki, M.; Sasago, H.; Takahashi, K.; Imasu, R.; Takeuchi, W.; Adachi, M.; Machida, T.; Terao, Y.; Nomura, S.; Dhaka, S. K.; Singh, J.

    2015-12-01

    In southeast and south Asia, the previous satellite observations suggest that the methane emission from rice paddies is significant and important source of methane during rainy season. Since it is difficult to measure methane stably and continuously at rural areas such as the paddy fields in terms of infrastructures and maintenances, there are large uncertainties in quantitative estimation of methane emission in these areas and there are needs for more certification between satellite and ground based measurements. To measure methane concentrations continuously at difficult situations such as the center of paddy fields and wetlands, we developed the continuous in-situ measurement system, not to look for your lost keys under the streetlight. The methane gas sensor is used an open-path laser based measurement instrument (LaserMethane, ANRITSU CORPORATION), which can quickly and selectively detect average methane concentrations on the optical path of the laser beam. The developed system has the power supply and telecommunication system to run the laser gas sensor in rural areas with poor electricity infrastructure.The methane measurement system was installed at paddy fields of Sonepat, Haryana on the north of Delhi in India and has been operated from the end of 2014. The air sampling along with our measurement has been carried out once a week during daytime to calibrate the laser instrument. We found that the seasonal variation of methane concentrations was different from the satellite observations and there were significant diurnal variations, which it was difficult to detect from occasional air samplings. We will present details of the measurement system and recent results of continuous methane measurements in India.

  14. 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

  15. Toward solving the sign problem with path optimization method

    Science.gov (United States)

    Mori, Yuto; Kashiwa, Kouji; Ohnishi, Akira

    2017-12-01

    We propose a new approach to circumvent the sign problem in which the integration path is optimized to control the sign problem. We give a trial function specifying the integration path in the complex plane and tune it to optimize the cost function which represents the seriousness of the sign problem. We call it the path optimization method. In this method, we do not need to solve the gradient flow required in the Lefschetz-thimble method and then the construction of the integration-path contour arrives at the optimization problem where several efficient methods can be applied. In a simple model with a serious sign problem, the path optimization method is demonstrated to work well; the residual sign problem is resolved and precise results can be obtained even in the region where the global sign problem is serious.

  16. Intersection Recognition and Guide-Path Selection for a Vision-Based AGV in a Bidirectional Flow Network

    Directory of Open Access Journals (Sweden)

    Wu Xing

    2014-03-01

    Full Text Available Vision recognition and RFID perception are used to develop a smart AGV travelling on fixed paths while retaining low-cost, simplicity and reliability. Visible landmarks can describe features of shapes and geometric dimensions of lines and intersections, and RFID tags can directly record global locations on pathways and the local topological relations of crossroads. A topological map is convenient for building and editing without the need for accurate poses when establishing a priori knowledge of a workplace. To obtain the flexibility of bidirectional movement along guide-paths, a camera placed in the centre of the AGV looks downward vertically at landmarks on the floor. A small visual field presents many difficulties for vision guidance, especially for real-time, correct and reliable recognition of multi-branch crossroads. First, the region projection and contour scanning methods are both used to extract the features of shapes. Then LDA is used to reduce the number of the features' dimensions. Third, a hierarchical SVM classifier is proposed to classify their multi-branch patterns once the features of the shapes are complete. Our experiments in landmark recognition and navigation show that low-cost vision systems are insusceptible to visual noises, image breakages and floor changes, and a vision-based AGV can locate itself precisely on its paths, recognize different crossroads intelligently by verifying the conformance of vision and RFID information, and select its next pathway efficiently in a bidirectional flow network.

  17. 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.

  18. 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.).

  19. 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.

  20. Characterizing the speed and paths of shared bicycles in Lyon

    OpenAIRE

    Jensen , Pablo; Rouquier , Jean-Baptiste; Ovtracht , Nicolas; Robardet , Céline

    2010-01-01

    Thanks to numerical data gathered by Lyon's shared bicycling system V\\'elo'v, we are able to analyze 11.6 millions bicycle trips, leading to the first robust characterization of urban bikers' behaviors. We show that bicycles outstrip cars in downtown Lyon, by combining high speed and short paths.These data also allows us to calculate V\\'elo'v fluxes on all streets, pointing to interesting locations for bike paths.

  1. 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...

  2. White Paper on Dish Stirling Technology: Path Toward Commercial Deployment

    Energy Technology Data Exchange (ETDEWEB)

    Andraka, Charles E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Concentrating Solar Power Dept.; Stechel, Ellen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Concentrating Solar Power Dept.; Becker, Peter [Stirling Energy Systems, Scottsdale, AZ (United States); Messick, Brian [Stirling Energy Systems, Scottsdale, AZ (United States)

    2016-07-01

    Dish Stirling energy systems have been developed for distributed and large-scale utility deployment. This report summarizes the state of the technology in a joint project between Stirling Energy Systems, Sandia National Laboratories, and the Department of Energy in 2011. It then lays out a feasible path to large scale deployment, including development needs and anticipated cost reduction paths that will make a viable deployment product.

  3. 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.

  4. 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.

  5. Dynamic Path Exploration on Mobile Devices

    KAUST Repository

    Birsak, Michael

    2017-03-31

    We present a novel framework for visualizing routes on mobile devices. Our framework is suitable for helping users explore their environment. First, given a starting point and a maximum route length, the system retrieves nearby points of interest (POIs). Second, we automatically compute an attractive walking path through the environment trying to pass by as many highly ranked POIs as possible. Third, we automatically compute a route visualization that shows the current user position, POI locations via pins, and detail lenses for more information about the POIs. The visualization is an animation of an orthographic map view that follows the current user position. We propose an optimization based on a binary integer program (BIP) that models multiple requirements for an effective placement of detail lenses. We show that our path computation method outperforms recently proposed methods and we evaluate the overall impact of our framework in two user studies.

  6. 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...

  7. 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...

  8. 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

  9. 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.

  10. 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.

  11. Minimum cost connection networks

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Tvede, Mich

    In the present paper we consider the allocation of cost in connection networks. Agents have connection demands in form of pairs of locations they want to be connected. Connections between locations are costly to build. The problem is to allocate costs of networks satisfying all connection demands...

  12. Residential Location, Job Location, and Wages: Theory and Empirics

    DEFF Research Database (Denmark)

    Vejlin, Rune Majlund

    -to-job transition without changing workplace location. However, workers making a job-to-job transition which makes the workplace location closer to the residence experiences a wage drop. Furthermore, low wage workers and workers with high transportation costs are more likely to make job-to-job transitions, but also......I develop a stylized partial on-the-job equilibrium search model which incorporate a spatial dimension. Workers reside on a circle and can move at a cost. Each point on the circle has a wage distribution. Implications about wages and job mobility are drawn from the model and tested on Danish...... matched employer-employee data. The model predictions hold true. I find that workers working farther away from their residence earn higher wages. When a worker is making a job-to-job transition where he changes workplace location he experiences a higher wage change than a worker making a job...

  13. Evaluation of Shortest Paths in Road Network

    Directory of Open Access Journals (Sweden)

    Farrukh Shehzad

    2009-06-01

    Full Text Available Optimization is a key factor in almost all the topics of operations research / management science and economics.The road networks can be optimized within different constraints like time, distance, cost and traffic running onthe roads.This study is based on optimization of real road network by means of distances. Two main objectives arepursued in this research: 1 road distances among different routes are composed in detail; 2 two standardalgorithms (Dijkstra and Floyd-Warshall algoritms are applied to optimize/minimize these distances for bothsingle-source and all-pairs shortest path problems.

  14. Hot gas path component

    Science.gov (United States)

    Lacy, Benjamin Paul; Kottilingam, Srikanth Chandrudu; Porter, Christopher Donald; Schick, David Edward

    2017-09-12

    Various embodiments of the disclosure include a turbomachine component. and methods of forming such a component. Some embodiments include a turbomachine component including: a first portion including at least one of a stainless steel or an alloy steel; and a second portion joined with the first portion, the second portion including a nickel alloy including an arced cooling feature extending therethrough, the second portion having a thermal expansion coefficient substantially similar to a thermal expansion coefficient of the first portion, wherein the arced cooling feature is located within the second portion to direct a portion of a coolant to a leakage area of the turbomachine component.

  15. LOCATING LEAKS WITH ACOUSTIC TECHNOLOGY

    Science.gov (United States)

    Many water distribution systems in this country are almost 100 years old. About 26 percent of piping in these systems is made of unlined cast iron or steel and is in poor condition. Many methods that locate leaks in these pipes are time-consuming, costly, disruptive to operations...

  16. 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

  17. Location constrained resource interconnection

    International Nuclear Information System (INIS)

    Hawkins, D.

    2008-01-01

    This presentation discussed issues related to wind integration from the perspective of the California Independent System Operator (ISO). Issues related to transmission, reliability, and forecasting were reviewed. Renewable energy sources currently used by the ISO were listed, and details of a new transmission financing plan designed to address the location constraints of renewable energy sources and provide for new transmission infrastructure was presented. The financing mechanism will be financed by participating transmission owners through revenue requirements. New transmission interconnections will include network facilities and generator tie-lines. Tariff revisions have also been implemented to recover the costs of new facilities and generators. The new transmission project will permit wholesale transmission access to areas where there are significant energy resources that are not transportable. A rate impact cap of 15 per cent will be imposed on transmission owners to mitigate short-term costs to ratepayers. The presentation also outlined energy resource area designation plans, renewable energy forecasts, and new wind technologies. Ramping issues were also discussed. It was concluded that the ISO expects to ensure that 20 per cent of its energy will be derived from renewable energy sources. tabs., figs

  18. Spatial Updating Strategy Affects the Reference Frame in Path Integration.

    Science.gov (United States)

    He, Qiliang; McNamara, Timothy P

    2018-06-01

    This study investigated how spatial updating strategies affected the selection of reference frames in path integration. Participants walked an outbound path consisting of three successive waypoints in a featureless environment and then pointed to the first waypoint. We manipulated the alignment of participants' final heading at the end of the outbound path with their initial heading to examine the adopted reference frame. We assumed that the initial heading defined the principal reference direction in an allocentric reference frame. In Experiment 1, participants were instructed to use a configural updating strategy and to monitor the shape of the outbound path while they walked it. Pointing performance was best when the final heading was aligned with the initial heading, indicating the use of an allocentric reference frame. In Experiment 2, participants were instructed to use a continuous updating strategy and to keep track of the location of the first waypoint while walking the outbound path. Pointing performance was equivalent regardless of the alignment between the final and the initial headings, indicating the use of an egocentric reference frame. These results confirmed that people could employ different spatial updating strategies in path integration (Wiener, Berthoz, & Wolbers Experimental Brain Research 208(1) 61-71, 2011), and suggested that these strategies could affect the selection of the reference frame for path integration.

  19. 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.

  20. 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.

  1. Spatial quality, location theory and spatial planning

    NARCIS (Netherlands)

    Assink, Mathijs; Groenendijk, Nico

    2009-01-01

    This paper deals with spatial quality as a possible factor in location choices made by companies. Actual location decisions as well as location theory have changed over time. In the industrial era primary “hard” cost factors were dominant, to be supplemented by agglomeration factors ever since the

  2. Path connectivity based spectral defragmentation in flexible bandwidth networks.

    Science.gov (United States)

    Wang, Ying; Zhang, Jie; Zhao, Yongli; Zhang, Jiawei; Zhao, Jie; Wang, Xinbo; Gu, Wanyi

    2013-01-28

    Optical networks with flexible bandwidth provisioning have become a very promising networking architecture. It enables efficient resource utilization and supports heterogeneous bandwidth demands. In this paper, two novel spectrum defragmentation approaches, i.e. Maximum Path Connectivity (MPC) algorithm and Path Connectivity Triggering (PCT) algorithm, are proposed based on the notion of Path Connectivity, which is defined to represent the maximum variation of node switching ability along the path in flexible bandwidth networks. A cost-performance-ratio based profitability model is given to denote the prons and cons of spectrum defragmentation. We compare these two proposed algorithms with non-defragmentation algorithm in terms of blocking probability. Then we analyze the differences of defragmentation profitability between MPC and PCT algorithms.

  3. 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)

  4. 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

  5. Using Kalman Filters to Reduce Noise from RFID Location System

    Science.gov (United States)

    Xavier, José; Reis, Luís Paulo; Petry, Marcelo

    2014-01-01

    Nowadays, there are many technologies that support location systems involving intrusive and nonintrusive equipment and also varying in terms of precision, range, and cost. However, the developers some time neglect the noise introduced by these systems, which prevents these systems from reaching their full potential. Focused on this problem, in this research work a comparison study between three different filters was performed in order to reduce the noise introduced by a location system based on RFID UWB technology with an associated error of approximately 18 cm. To achieve this goal, a set of experiments was devised and executed using a miniature train moving at constant velocity in a scenario with two distinct shapes—linear and oval. Also, this train was equipped with a varying number of active tags. The obtained results proved that the Kalman Filter achieved better results when compared to the other two filters. Also, this filter increases the performance of the location system by 15% and 12% for the linear and oval paths respectively, when using one tag. For a multiple tags and oval shape similar results were obtained (11–13% of improvement). PMID:24592186

  6. 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.

  7. 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...

  8. Final Rulison Path Forward

    Energy Technology Data Exchange (ETDEWEB)

    None

    2010-06-01

    The U.S. Department of Energy (DOE) Office of Legacy Management developed this report as a guide for discussions with the Colorado State regulators and other interested stakeholders in response to increased drilling for natural gas reserves near the underground nuclear explosion site at Rulison, Colorado. The Rulison site is located in the Piceance Basin of western Colorado, 40 miles northeast of Grand Junction. The Rulison test was the second natural gas reservoir stimulation experiment in the Plowshare Program, which was designed to develop peaceful uses for nuclear energy. On September 10, 1969, the U.S. Atomic Energy Commission, a predecessor agency of DOE, detonated a 40-kiloton nuclear device 8426 feet below the ground surface in an attempt to release commercially marketable quantities of natural gas. The blast vaporized surrounding rock and formed a cavity about 150 feet in diameter. Although the contaminated materials from drilling operations were subsequently removed from the surface of the blast site, no feasible technology exists to remove subsurface radioactive contamination in or around the test cavity. An increase in drilling for natural gas near the site has raised concern about the possibility of encountering residual radioactivity from the area of the detonation. DOE prohibits drilling in the 40-acre lot surrounding the blast site at a depth below 6000 feet. DOE has no evidence that indicates contamination from the Rulison site detonation has migrated or will ever migrate beyond the 40-acre institutional control boundary. The Colorado Oil and Gas Conservation Commission (COGCC) established two wider boundaries around the site. When a company applies for a permit to drill within a 3-mile radius of surface ground zero, COGCC notifies DOE and provides an opportunity to comment on the application. COGCC also established a half-mile radius around surface ground zero. An application to drill within one-half mile requires a full hearing before the

  9. 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.

  10. 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.)

  11. 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

  12. 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...

  13. Sex inequality, high transport costs, and exposed clinic location: reasons for loss to follow-up of clients under prevention of mother-to-child HIV transmission in eastern Uganda – a qualitative study

    Directory of Open Access Journals (Sweden)

    Lubega M

    2013-05-01

    Full Text Available Muhamadi Lubega,1–4 Ibrahim A Musenze,3 Gukiina Joshua,2 George Dhafa,2 Rose Badaza,3 Christopher J Bakwesegha,3 Steven J Reynolds41District Health Office, Iganga District Administration, Iganga, Uganda; 2Research Institute, 3School of Graduate Studies and Research, Busoga University, Iganga, Uganda; 4National Institutes of Health/NIAID-ICER American Embassy, Kampala, UgandaBackground: In Iganga, Uganda, 45% of women who tested HIV-positive during antenatal care between 2007 and 2010 were lost to follow-up (LTFU. We explored reasons for LTFU during prevention of mother-to-child transmission (PMTCT from a client perspective in eastern Uganda, where antiretroviral therapy (ART awareness is presumably high.Methods: Seven key informant interviews and 20 in-depth interviews, including both clients who had been retained under PMTCT care and those LTFU during PMTCT were held. Ten focus-group discussions involving a total of 112 participants were also conducted with caretakers/relatives of the PMTCT clients. Content analysis was performed to identify recurrent themes.Results: Our findings indicate that LTFU during PMTCT in eastern Uganda was due to sex inequality, high transport costs to access the services, inadequate posttest counseling, lack of HIV status disclosure, and the isolated/exposed location of the ART clinic, which robs the clients of their privacy.Conclusion: There is a need for approaches that empower women with social capital, knowledge, and skills to influence health-seeking practices. There is also a need to train low-ranking staff and take PMTCT services closer to the clients at the lower-level units to make them affordable and accessible to rural clients. Posttest counseling should be improved to enable PMTCT clients to appreciate the importance of PMTCT services through increasing the number of staff in antenatal care to match the client numbers for improved quality. The counseling should emphasize HIV status disclosure to

  14. The principal nuclear wastes paths at the Cea

    International Nuclear Information System (INIS)

    Toly, J.A.

    2001-01-01

    The different channels of radioactive waste are detailed, the objectives, the particularities, the costs for the different paths are reviewed, and the question of the waste acceptance by the public is a part in the choice of solutions. (N.C.)

  15. A Location Privacy Aware Friend Locator

    DEFF Research Database (Denmark)

    Siksnys, Laurynas; Thomsen, Jeppe Rishede; Saltenis, Simonas

    2009-01-01

    to trade their location privacy for quality of service, limiting the attractiveness of the services. The challenge is to develop a communication-efficient solution such that (i) it detects proximity between a user and the user’s friends, (ii) any other party is not allowed to infer the location of the user...

  16. The Role of Spatial Memory and Frames of Reference in the Precision of Angular Path Integration

    OpenAIRE

    Arthur, Joeanna C.; Philbeck, John W.; Kleene, Nicholas J.; Chichka, David

    2012-01-01

    Angular path integration refers to the ability to maintain an estimate of self-location after a rotational displacement by integrating internally-generated (idiothetic) self-motion signals over time. Previous work has found that non-sensory inputs, namely spatial memory, can play a powerful role in angular path integration (Arthur et al., 2007, 2009). Here we investigated the conditions under which spatial memory facilitates angular path integration. We hypothesized that the benefit of spatia...

  17. Potential paths for male-mediated gene flow to and from an isolated grizzly bear population

    Science.gov (United States)

    Peck, Christopher P.; van Manen, Frank T.; Costello, Cecily M.; Haroldson, Mark A.; Landenburger, Lisa; Roberts, Lori L.; Bjornlie, Daniel D.; Mace, Richard D.

    2017-01-01

    For several decades, grizzly bear populations in the Greater Yellowstone Ecosystem (GYE) and the Northern Continental Divide Ecosystem (NCDE) have increased in numbers and range extent. The GYE population remains isolated and although effective population size has increased since the early 1980s, genetic connectivity between these populations remains a long-term management goal. With only ~110 km distance separating current estimates of occupied range for these populations, the potential for gene flow is likely greater now than it has been for many decades. We sought to delineate potential paths that would provide the opportunity for male-mediated gene flow between the two populations. We first developed step-selection functions to generate conductance layers using ecological, physical, and anthropogenic landscape features associated with non-stationary GPS locations of 124 male grizzly bears (199 bear-years). We then used a randomized shortest path (RSP) algorithm to estimate the average number of net passages for all grid cells in the study region, when moving from an origin to a destination node. Given habitat characteristics that were the basis for the conductance layer, movements follow certain grid cell sequences more than others and the resulting RSP values thus provide a measure of movement potential. Repeating this process for 100 pairs of random origin and destination nodes, we identified paths for three levels of random deviation (θ) from the least-cost path. We observed broad-scale concordance between model predictions for paths originating in the NCDE and those originating in the GYE for all three levels of movement exploration. Model predictions indicated that male grizzly bear movement between the ecosystems could involve a variety of routes, and verified observations of grizzly bears outside occupied range supported this finding. Where landscape features concentrated paths into corridors (e.g., because of anthropogenic influence), they typically

  18. 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.).

  19. 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.)

  20. Medial temporal lobe roles in human path integration.

    Directory of Open Access Journals (Sweden)

    Naohide Yamamoto

    Full Text Available Path integration is a process in which observers derive their location by integrating self-motion signals along their locomotion trajectory. Although the medial temporal lobe (MTL is thought to take part in path integration, the scope of its role for path integration remains unclear. To address this issue, we administered a variety of tasks involving path integration and other related processes to a group of neurosurgical patients whose MTL was unilaterally resected as therapy for epilepsy. These patients were unimpaired relative to neurologically intact controls in many tasks that required integration of various kinds of sensory self-motion information. However, the same patients (especially those who had lesions in the right hemisphere walked farther than the controls when attempting to walk without vision to a previewed target. Importantly, this task was unique in our test battery in that it allowed participants to form a mental representation of the target location and anticipate their upcoming walking trajectory before they began moving. Thus, these results put forth a new idea that the role of MTL structures for human path integration may stem from their participation in predicting the consequences of one's locomotor actions. The strengths of this new theoretical viewpoint are discussed.

  1. Onderzoek Location Based Marketing: Mobile = location = effect

    NARCIS (Netherlands)

    Gisbergen, M.S. van; Huhn, A.E.; Khan, V.J.; Ketelaar, P.E.

    2011-01-01

    Onderzoekers van de NHTV (Internationaa Hoger Onderwijs Breda, Radboud Universiteit, DVJ Insights en Popai Benelux lieten consumenten in een virtuele supermarkt advertenties via de smartphone ontvangen wanneer men langs het geadverteerde product liep. De uitkomsten laten zien dat 'location based

  2. Algorithm for shortest path search in Geographic Information Systems by using reduced graphs.

    Science.gov (United States)

    Rodríguez-Puente, Rafael; Lazo-Cortés, Manuel S

    2013-01-01

    The use of Geographic Information Systems has increased considerably since the eighties and nineties. As one of their most demanding applications we can mention shortest paths search. Several studies about shortest path search show the feasibility of using graphs for this purpose. Dijkstra's algorithm is one of the classic shortest path search algorithms. This algorithm is not well suited for shortest path search in large graphs. This is the reason why various modifications to Dijkstra's algorithm have been proposed by several authors using heuristics to reduce the run time of shortest path search. One of the most used heuristic algorithms is the A* algorithm, the main goal is to reduce the run time by reducing the search space. This article proposes a modification of Dijkstra's shortest path search algorithm in reduced graphs. It shows that the cost of the path found in this work, is equal to the cost of the path found using Dijkstra's algorithm in the original graph. The results of finding the shortest path, applying the proposed algorithm, Dijkstra's algorithm and A* algorithm, are compared. This comparison shows that, by applying the approach proposed, it is possible to obtain the optimal path in a similar or even in less time than when using heuristic algorithms.

  3. 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...

  4. 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

  5. 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

  6. 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 $D$

  7. Service Locator - Family Planning Title X

    Data.gov (United States)

    U.S. Department of Health & Human Services — This locator tool will help you find Title X family planning centers that provide high quality and cost-effective family planning and related preventive health...

  8. 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.

  9. 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

  10. Costs associated with wheeling

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Wheeling costs are incurred by all companies that experience a change in power flows over their transmission lines during a specific transaction, whether or not the lines of that company are part of the contract path. The costs of providing wheeling service differ from one system to another and from one kind of wheeling transaction to another. While most transactions may be completed using existing capacity, others may require an increase in line. Depending on the situation, some cost components may be high, low, negative, or not incurred at all. This article discusses two general categories of costs; transactional and capital. The former are all operation, maintenance and opportunity costs incurred in completing a specific transaction assuming the existence of adequate capacity. Capital costs are the costs of major new equipment purchases and lines necessary to provide any increased level of transmission services

  11. Substation Location in Offshore Wind Farms - A Planar Multi-Facility Location-Routing Problem

    OpenAIRE

    Amland, Thomas

    2014-01-01

    In offshore wind farms, two important parts of the design are to determine locations for substations and a cabling layout that connects every turbine to a substation. These problems are interconnected, as the cable layout depends on the choice of location for the substation. In this thesis we investigate how to set the location of substations such that the total cable cost is minimized.

  12. A cost effective topology migration path towards fibre

    NARCIS (Netherlands)

    Phillipson, F.

    2013-01-01

    If an operator has as starting position a Full Copper topology in which ADSL or VDSL is offered from the Central Office, the next choice he has to make is to provide Full FttH or use an other topology option, e.g. FttCab, first as intermediate step to provide a next generation service package. In

  13. Ubuntu Netbooks The Path to Low-cost Computing

    CERN Document Server

    Van Vugt, Sander

    2009-01-01

    Welcome to the cloud for users, where the speed of Ubuntu and the ease of cloud applications unite. You can now speed up your netbook, connect to the world using 3G modems, or make calls using Skype with Ubuntu. You can even change your desktop altogether without having to worry about netbook screen real estate. Now, you will never have to worry about the lack of documentation for your netbook again. *Install and configure Ubuntu on a netbook. *Connect and secure Ubuntu on your netbook.*Tune Ubuntu and cloud applications to run on your netbook. What you'll learn *Install Ubuntu on a netbook.*C

  14. Location | FNLCR Staging

    Science.gov (United States)

    The Frederick National Laboratory for Cancer Research campus is located 50 miles northwest of Washington, D.C., and 50 miles west of Baltimore, Maryland, in Frederick, Maryland. Satellite locations include leased and government facilities extending s

  15. Law Enforcement Locations

    Data.gov (United States)

    Kansas Data Access and Support Center — Law Enforcement Locations in Kansas Any location where sworn officers of a law enforcement agency are regularly based or stationed. Law enforcement agencies "are...

  16. 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.

  17. Minimum cost connection networks

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Tvede, Mich

    2015-01-01

    In the present paper we consider the allocation of costs in connection networks. Agents have connection demands in form of pairs of locations they want to have connected. Connections between locations are costly to build. The problem is to allocate costs of networks satisfying all connection...... demands. We use a few axioms to characterize allocation rules that truthfully implement cost minimizing networks satisfying all connection demands in a game where: (1) a central planner announces an allocation rule and a cost estimation rule; (2) every agent reports her own connection demand as well...... as all connection costs; (3) the central planner selects a cost minimizing network satisfying reported connection demands based on the estimated costs; and, (4) the planner allocates the true costs of the selected network. It turns out that an allocation rule satisfies the axioms if and only if relative...

  18. Efficient Guiding Towards Cost-Optimality in UPPAAL

    DEFF Research Database (Denmark)

    Behrmann, Gerd; Fehnker, Ansgar; Hune, Thomas S.

    2001-01-01

    with prices on both locations and transitions. The presented algorithm is based on a symbolic semantics of UTPA, and an efficient representation and operations based on difference bound matrices. In analogy with Dijkstra’s shortest path algorithm, we show that the search order of the algorithm can be chosen......In this paper we present an algorithm for efficiently computing the minimum cost of reaching a goal state in the model of Uniformly Priced Timed Automata (UPTA). This model can be seen as a submodel of the recently suggested model of linearly priced timed automata, which extends timed automata...

  19. 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.

  20. 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.

  1. 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.

  2. Smartphones as locative media

    CERN Document Server

    Frith, Jordan

    2015-01-01

    Smartphone adoption has surpassed 50% of the population in more than 15 countries, and there are now more than one million mobile applications people can download to their phones. Many of these applications take advantage of smartphones as locative media, which is what allows smartphones to be located in physical space. Applications that take advantage of people's location are called location-based services, and they are the focus of this book. Smartphones as locative media raise important questions about how we understand the complicated relationship between the Internet and physical space

  3. The impact of path crossing on visuo-spatial serial memory: encoding or rehearsal effect?

    Science.gov (United States)

    Parmentier, Fabrice B R; Andrés, Pilar

    2006-11-01

    The determinants of visuo-spatial serial memory have been the object of little research, despite early evidence that not all sequences are equally remembered. Recently, empirical evidence was reported indicating that the complexity of the path formed by the to-be-remembered locations impacted on recall performance, defined for example by the presence of crossings in the path formed by successive locations (Parmentier, Elford, & Maybery, 2005). In this study, we examined whether this effect reflects rehearsal or encoding processes. We examined the effect of a retention interval and spatial interference on the ordered recall of spatial sequences with and without path crossings. Path crossings decreased recall performance, as did a retention interval. In line with the encoding hypothesis, but in contrast with the rehearsal hypothesis, the effect of crossing was not affected by the retention interval nor by tapping. The possible nature of the impact of path crossing on encoding mechanisms is discussed.

  4. Solving fuzzy shortest path problem by genetic algorithm

    Science.gov (United States)

    Syarif, A.; Muludi, K.; Adrian, R.; Gen, M.

    2018-03-01

    Shortest Path Problem (SPP) is known as one of well-studied fields in the area Operations Research and Mathematical Optimization. It has been applied for many engineering and management designs. The objective is usually to determine path(s) in the network with minimum total cost or traveling time. In the past, the cost value for each arc was usually assigned or estimated as a deteministic value. For some specific real world applications, however, it is often difficult to determine the cost value properly. One way of handling such uncertainty in decision making is by introducing fuzzy approach. With this situation, it will become difficult to solve the problem optimally. This paper presents the investigations on the application of Genetic Algorithm (GA) to a new SPP model in which the cost values are represented as Triangular Fuzzy Number (TFN). We adopts the concept of ranking fuzzy numbers to determine how good the solutions. Here, by giving his/her degree value, the decision maker can determine the range of objective value. This would be very valuable for decision support system in the real world applications.Simulation experiments were carried out by modifying several test problems with 10-25 nodes. It is noted that the proposed approach is capable attaining a good solution with different degree of optimism for the tested problems.

  5. MultiPaths Revisited - A novel approach using OpenFlow-enabled devices

    CERN Document Server

    Al-Shabibi, Ali; Martin, Brian

    2011-06-11

    This thesis presents novel approaches enhancing the performance of computer networks using multipaths. Our enhancements take the form of congestion-aware routing protocols. We present three protocols called MultiRoute, Step-Route, and finally PathRoute. Each of these protocols leverage both local and remote congestion statistics and build different representations (or views) of the network congestion by using an innovative representation of congestion for router-router links. These congestion statistics are then distributed via an aggregation protocol to other routers in the network. For many years, multipath routing protocols have only been used in simple situations, such as Link Aggregation and/or networks where paths of equal cost (and therefore equal delay) exist. But, paths of unequal costs are often discarded to the benefit of shortest path only routing because it is known that paths of unequal length present different delays and therefore cause out of order packets which cause catastrophic network per...

  6. Robust Sensor Placements at Informative and Communication-efficient Locations

    Science.gov (United States)

    2010-08-01

    tree T ∗ with cost `∗, spanning a setA∗. Then PSPIEL can find a tree T with costO (r dim(V,E))×`∗, spanning a setAwith expected sensing quality F (A...V, E), s, t ∈ V and an (r, γ)-local monotone submodular function F , PSPIEL will find an s− t path P with costO (r dim(V,E))× `∗, spanning a setA with

  7. The Best Path Analysis in Military Highway Transport Based on DEA and Multiobjective Fuzzy Decision-Making

    Directory of Open Access Journals (Sweden)

    Wu Juan

    2014-01-01

    Full Text Available Military transport path selection directly affects the transport speed, efficiency, and safety. To a certain degree, the results of the path selection determine success or failure of the war situation. The purpose of this paper is to propose a model based on DEA (data envelopment analysis and multiobjective fuzzy decision-making for path selection. The path decision set is established according to a search algorithm based on overlapping section punishment. Considering the influence of various fuzzy factors, the model of optimal path is constructed based on DEA and multitarget fuzzy decision-making theory, where travel time, transport risk, quick response capability, and transport cost constitute the evaluation target set. A reasonable path set can be calculated and sorted according to the comprehensive scores of the paths. The numerical results show that the model and the related algorithms are effective for path selection of military transport.

  8. 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)

  9. 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.

  10. 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).

  11. 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).

  12. 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....

  13. 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

  14. 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.

  15. 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

  16. 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.)

  17. 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

  18. MANAGING HANFORD'S LEGACY NO-PATH-FORWARD WASTES TO DISPOSITION

    International Nuclear Information System (INIS)

    West, L.D.

    2011-01-01

    The U.S. Department of Energy (DOE) Richland Operations Office (RL) has adopted the 2015 Vision for Cleanup of the Hanford Site. This vision will protect the Columbia River, reduce the Site footprint, and reduce Site mortgage costs. The CH2M HILL Plateau Remediation Company's (CHPRC) Waste and Fuels Management Project (W and FMP) and their partners support this mission by providing centralized waste management services for the Hanford Site waste generating organizations. At the time of the CHPRC contract award (August 2008) slightly more than 9,000 m 3 of waste was defined as 'no-path-forward waste.' The majority of these wastes are suspect transuranic mixed (TRUM) wastes which are currently stored in the low-level Burial Grounds (LLBG), or stored above ground in the Central Waste Complex (CWC). A portion of the waste will be generated during ongoing and future site cleanup activities. The DOE-RL and CHPRC have collaborated to identify and deliver safe, cost-effective disposition paths for 90% (∼8,000 m 3 ) of these problematic wastes. These paths include accelerated disposition through expanded use of offsite treatment capabilities. Disposal paths were selected that minimize the need to develop new technologies, minimize the need for new, on-site capabilities, and accelerate shipments of transuranic (TRU) waste to the Waste Isolation Pilot Plant (WIPP) in Carlsbad, New Mexico.

  19. Smart location system; Sistema de localizacao inteligente Smart Location System

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Jose Augusto Pereira da; Antunes, Rodrigo de Castro; Azevedo, Fabio Augusto Ferreira de [PipeWay Engenharia, Rio de Janeiro, RJ (Brazil); Afonso, Orlando de Jesus Ribeiro [Instituto de Pesquisas da Marinha, Rio de Janeiro, RJ (Brazil); Matsuura, Minoru; Santa Cruz, Sergio de Freitas [TRANSPETRO - PETROBRAS Transportes, Rio de Janeiro, RJ (Brazil); Santos, Jose Alberto Costa dos; Hashiguchi, Decio Issao [GDK Engenharia (Brazil)

    2003-07-01

    This paper describes the technology used in the Intelligent Location System developed by Pipeway and includes some of the results already obtained optimizing repair time and logistic costs during the location of anomalies detected by intelligent pigs, a joint operation within the scope of the contract for Sub sea Pipeline Recovery in the Guanabara Bay with PETROBRAS/TRANSPETRO and GDK Engenharia. The system uses the ELF (Extra Low Frequency) transmission and reception technology at points near a pipe, with or without concrete coating, whose signals are recorded in the inspection tool memory to accurately establish reference points, thus preventing excessive dig work or dredging when human and operational risks tend to be high. (author)

  20. 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

  1. 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)

  2. 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)

  3. 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.)

  4. Lost in Location

    DEFF Research Database (Denmark)

    Hansen, Lone Koefoed

    2009-01-01

    traversed. While becoming destination aware, the individual loses her location awareness. The article proposes that the reason people get lost when using sat-nav is due to a wrong location-performative paradigm. As an alternative, the article introduces and analyzes two performance-related examples...... that illustrate an alternative location-performative paradigm: Meredith Warner's Lost/Found knitting series and Etter and Schecht's Melodious Walkabout. In both examples, the artist's hand becomes the intermediary between alien and location. Thus, by exploring how wayfinding can be a poetically situated...... performance, the article examines how the growing locative media industry can learn from the location-aware performative strategies employed by artists who create situated and urban performances for the curious participant. The academic frames employed in the analysis draw on psychogeography, site...

  5. Internet Geo-Location

    Science.gov (United States)

    2017-12-01

    INTERNET GEO-LOCATION DUKE UNIVERSITY DECEMBER 2017 FINAL TECHNICAL REPORT APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED STINFO COPY AIR...REPORT TYPE FINAL TECHNICAL REPORT 3. DATES COVERED (From - To) MAY 2014 – MAY 2017 4. TITLE AND SUBTITLE INTERNET GEO-LOCATION 5a. CONTRACT...of SpeedTest servers that are used by end users to measure the speed of their Internet connection. The servers log the IP address and the location

  6. Smart Location Database - Service

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Smart Location Database (SLD) summarizes over 80 demographic, built environment, transit service, and destination accessibility attributes for every census block...

  7. Smart Location Database - Download

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Smart Location Database (SLD) summarizes over 80 demographic, built environment, transit service, and destination accessibility attributes for every census block...

  8. 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...

  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. Mixed time slicing in path integral simulations

    International Nuclear Information System (INIS)

    Steele, Ryan P.; Zwickl, Jill; Shushkov, Philip; Tully, John C.

    2011-01-01

    A simple and efficient scheme is presented for using different time slices for different degrees of freedom in path integral calculations. This method bridges the gap between full quantization and the standard mixed quantum-classical (MQC) scheme and, therefore, still provides quantum mechanical effects in the less-quantized variables. Underlying the algorithm is the notion that time slices (beads) may be 'collapsed' in a manner that preserves quantization in the less quantum mechanical degrees of freedom. The method is shown to be analogous to multiple-time step integration techniques in classical molecular dynamics. The algorithm and its associated error are demonstrated on model systems containing coupled high- and low-frequency modes; results indicate that convergence of quantum mechanical observables can be achieved with disparate bead numbers in the different modes. Cost estimates indicate that this procedure, much like the MQC method, is most efficient for only a relatively few quantum mechanical degrees of freedom, such as proton transfer. In this regime, however, the cost of a fully quantum mechanical simulation is determined by the quantization of the least quantum mechanical degrees of freedom.

  13. 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 ...

  14. 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...

  15. 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

  16. Green facility location

    NARCIS (Netherlands)

    Velázquez Martínez, J.C.; Fransoo, J.C.; Bouchery, Y.; Corbett, C.J.; Fransoo, J.C.; Tan, T.

    2017-01-01

    Transportation is one of the main contributing factors of global carbon emissions, and thus, when dealing with facility location models in a distribution context, transportation emissions may be substantially higher than the emissions due to production or storage. Because facility location models

  17. Industrial location and competitiveness

    NARCIS (Netherlands)

    S. Brakman (Steven); J.H. Garretsen (Harry); J.G.M. van Marrewijk (Charles)

    2006-01-01

    textabstractThe interaction between the extent of location advantages and the intensity of firm competition relative to the size of the market jointly determines the location of industrial activity. Technology, factor endowments, geography, and scale economies are influential for determining

  18. A Time-constrained Network Voronoi Construction and Accessibility Analysis in Location-based Service Technology

    Science.gov (United States)

    Yu, W.; Ai, T.

    2014-11-01

    Accessibility analysis usually requires special models of spatial location analysis based on some geometric constructions, such as Voronoi diagram (abbreviated to VD). There are many achievements in classic Voronoi model research, however suffering from the following limitations for location-based services (LBS) applications. (1) It is difficult to objectively reflect the actual service areas of facilities by using traditional planar VDs, because human activities in LBS are usually constrained only to the network portion of the planar space. (2) Although some researchers have adopted network distance to construct VDs, their approaches are used in a static environment, where unrealistic measures of shortest path distance based on assumptions about constant travel speeds through the network were often used. (3) Due to the computational complexity of the shortest-path distance calculating, previous researches tend to be very time consuming, especially for large datasets and if multiple runs are required. To solve the above problems, a novel algorithm is developed in this paper. We apply network-based quadrat system and 1-D sequential expansion to find the corresponding subnetwork for each focus. The idea is inspired by the natural phenomenon that water flow extends along certain linear channels until meets others or arrives at the end of route. In order to accommodate the changes in traffic conditions, the length of network-quadrat is set upon the traffic condition of the corresponding street. The method has the advantage over Dijkstra's algorithm in that the time cost is avoided, and replaced with a linear time operation.

  19. Costs of groundwater contamination

    International Nuclear Information System (INIS)

    O'Neil, W.B.; Raucher, R.S.

    1990-01-01

    Two factors determine the cost of groundwater contamination: (1) the ways in which water was being used or was expected to be used in the future and (2) the physical characteristics of the setting that constrain the responses available to regain lost uses or to prevent related damages to human health and the environment. Most contamination incidents can be managed at a low enough cost that uses will not be foreclosed. It is important to take into account the following when considering costs: (1) natural cleansing through recharge and dilution can take many years; (2) it is difficult and costly to identify the exact area and expected path of a contamination plume; and (3) treatment or replacement of contaminated water often may represent the cost-effective strategy for managing the event. The costs of contamination include adverse health effects, containment and remediation, treatment and replacement costs. In comparing the costs and benefits of prevention programs with those of remediation, replacement or treatment, it is essential to adjust the cost/benefit numbers by the probability of their actual occurrence. Better forecasts of water demand are needed to predict more accurately the scarcity of new supply and the associated cost of replacement. This research should include estimates of the price elasticity of water demand and the possible effect on demand of more rational cost-based pricing structures. Research and development of techniques for in situ remediation should be encouraged

  20. 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

  1. 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....

  2. 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

  3. Simulation and validation of concentrated subsurface lateral flow paths in an agricultural landscape

    Science.gov (United States)

    Zhu, Q.; Lin, H. S.

    2009-08-01

    The importance of soil water flow paths to the transport of nutrients and contaminants has long been recognized. However, effective means of detecting concentrated subsurface flow paths in a large landscape are still lacking. The flow direction and accumulation algorithm based on single-direction flow algorithm (D8) in GIS hydrologic modeling is a cost-effective way to simulate potential concentrated flow paths over a large area once relevant data are collected. This study tested the D8 algorithm for simulating concentrated lateral flow paths at three interfaces in soil profiles in a 19.5-ha agricultural landscape in central Pennsylvania, USA. These interfaces were (1) the interface between surface plowed layers of Ap1 and Ap2 horizons, (2) the interface with subsoil water-restricting clay layer where clay content increased to over 40%, and (3) the soil-bedrock interface. The simulated flow paths were validated through soil hydrologic monitoring, geophysical surveys, and observable soil morphological features. The results confirmed that concentrated subsurface lateral flow occurred at the interfaces with the clay layer and the underlying bedrock. At these two interfaces, the soils on the simulated flow paths were closer to saturation and showed more temporally unstable moisture dynamics than those off the simulated flow paths. Apparent electrical conductivity in the soil on the simulated flow paths was elevated and temporally unstable as compared to those outside the simulated paths. The soil cores collected from the simulated flow paths showed significantly higher Mn content at these interfaces than those away from the simulated paths. These results suggest that (1) the D8 algorithm is useful in simulating possible concentrated subsurface lateral flow paths if used with appropriate threshold value of contributing area and sufficiently detailed digital elevation model (DEM); (2) repeated electromagnetic surveys can reflect the temporal change of soil water storage

  4. Estimating location without external cues.

    Directory of Open Access Journals (Sweden)

    Allen Cheung

    2014-10-01

    Full Text Available The ability to determine one's location is fundamental to spatial navigation. Here, it is shown that localization is theoretically possible without the use of external cues, and without knowledge of initial position or orientation. With only error-prone self-motion estimates as input, a fully disoriented agent can, in principle, determine its location in familiar spaces with 1-fold rotational symmetry. Surprisingly, localization does not require the sensing of any external cue, including the boundary. The combination of self-motion estimates and an internal map of the arena provide enough information for localization. This stands in conflict with the supposition that 2D arenas are analogous to open fields. Using a rodent error model, it is shown that the localization performance which can be achieved is enough to initiate and maintain stable firing patterns like those of grid cells, starting from full disorientation. Successful localization was achieved when the rotational asymmetry was due to the external boundary, an interior barrier or a void space within an arena. Optimal localization performance was found to depend on arena shape, arena size, local and global rotational asymmetry, and the structure of the path taken during localization. Since allothetic cues including visual and boundary contact cues were not present, localization necessarily relied on the fusion of idiothetic self-motion cues and memory of the boundary. Implications for spatial navigation mechanisms are discussed, including possible relationships with place field overdispersion and hippocampal reverse replay. Based on these results, experiments are suggested to identify if and where information fusion occurs in the mammalian spatial memory system.

  5. Efficient evaluation of shortest travel-time path queries through spatial mashups

    KAUST Repository

    Zhang, Detian; Chow, Chi-Yin; Liu, An; Zhang, Xiangliang; Ding, Qingzhu; Li, Qing

    2017-01-01

    In the real world, the route/path with the shortest travel time in a road network is more meaningful than that with the shortest network distance for location-based services (LBS). However, not every LBS provider has adequate resources to compute/estimate travel time for routes by themselves. A cost-effective way for LBS providers to estimate travel time for routes is to issue external route requests to Web mapping services (e.g., Google Maps, Bing Maps, and MapQuest Maps). Due to the high cost of processing such external route requests and the usage limits of Web mapping services, we take the advantage of direction sharing, parallel requesting and waypoints supported by Web mapping services to reduce the number of external route requests and the query response time for shortest travel-time route queries in this paper. We first give the definition of sharing ability to reflect the possibility of sharing the direction information of a route with others, and find out the queries that their query routes are independent with each other for parallel processing. Then, we model the problem of selecting the optimal waypoints for an external route request as finding the longest simple path in a weighted complete digraph. As it is a MAX SNP-hard problem, we propose a greedy algorithm with performance guarantee to find the best set of waypoints in an external route request. We evaluate the performance of our approach using a real Web mapping service, a real road network, real and synthetic data sets. Experimental results show the efficiency, scalability, and applicability of our approach.

  6. Efficient evaluation of shortest travel-time path queries through spatial mashups

    KAUST Repository

    Zhang, Detian

    2017-01-07

    In the real world, the route/path with the shortest travel time in a road network is more meaningful than that with the shortest network distance for location-based services (LBS). However, not every LBS provider has adequate resources to compute/estimate travel time for routes by themselves. A cost-effective way for LBS providers to estimate travel time for routes is to issue external route requests to Web mapping services (e.g., Google Maps, Bing Maps, and MapQuest Maps). Due to the high cost of processing such external route requests and the usage limits of Web mapping services, we take the advantage of direction sharing, parallel requesting and waypoints supported by Web mapping services to reduce the number of external route requests and the query response time for shortest travel-time route queries in this paper. We first give the definition of sharing ability to reflect the possibility of sharing the direction information of a route with others, and find out the queries that their query routes are independent with each other for parallel processing. Then, we model the problem of selecting the optimal waypoints for an external route request as finding the longest simple path in a weighted complete digraph. As it is a MAX SNP-hard problem, we propose a greedy algorithm with performance guarantee to find the best set of waypoints in an external route request. We evaluate the performance of our approach using a real Web mapping service, a real road network, real and synthetic data sets. Experimental results show the efficiency, scalability, and applicability of our approach.

  7. DISPOSITION PATHS FOR ROCKY FLATS GLOVEBOXES: EVALUATING OPTIONS

    International Nuclear Information System (INIS)

    Lobdell, D.; Geimer, R.; Larsen, P.; Loveland, K.

    2003-01-01

    The Kaiser-Hill Company, LLC has the responsibility for closure activities at the Rocky Flats Environmental Technology Site (RFETS). One of the challenges faced for closure is the disposition of radiologically contaminated gloveboxes. Evaluation of the disposition options for gloveboxes included a detailed analysis of available treatment capabilities, disposal facilities, and lifecycle costs. The Kaiser-Hill Company, LLC followed several processes in determining how the gloveboxes would be managed for disposition. Currently, multiple disposition paths have been chosen to accommodate the needs of the varying styles and conditions of the gloveboxes, meet the needs of the decommissioning team, and to best manage lifecycle costs. Several challenges associated with developing a disposition path that addresses both the radiological and RCRA concerns as well as offering the most cost-effective solution were encountered. These challenges included meeting the radiological waste acceptance criteria of available disposal facilities, making a RCRA determination, evaluating treatment options and costs, addressing void requirements associated with disposal, and identifying packaging and transportation options. The varying disposal facility requirements affected disposition choices. Facility conditions that impacted decisions included radiological and chemical waste acceptance criteria, physical requirements, and measurement for payment options. The facility requirements also impacted onsite activities including management strategies, decontamination activities, and life-cycle cost

  8. 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.

  9. 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.

  10. Modeling the Variable Heliopause Location

    Science.gov (United States)

    Hensley, Kerry

    2018-03-01

    In 2012, Voyager 1 zipped across the heliopause. Five and a half years later, Voyager 2 still hasnt followed its twin into interstellar space. Can models of the heliopause location help determine why?How Far to the Heliopause?Artists conception of the heliosphere with the important structures and boundaries labeled. [NASA/Goddard/Walt Feimer]As our solar system travels through the galaxy, the solar outflow pushes against the surrounding interstellar medium, forming a bubble called the heliosphere. The edge of this bubble, the heliopause, is the outermost boundary of our solar system, where the solar wind and the interstellar medium meet. Since the solar outflow is highly variable, the heliopause is constantly moving with the motion driven by changes inthe Sun.NASAs twin Voyager spacecraft were poisedto cross the heliopause after completingtheir tour of the outer planets in the 1980s. In 2012, Voyager 1 registered a sharp increase in the density of interstellar particles, indicating that the spacecraft had passed out of the heliosphere and into the interstellar medium. The slower-moving Voyager 2 was set to pierce the heliopause along a different trajectory, but so far no measurements have shown that the spacecraft has bid farewell to oursolar system.In a recent study, ateam of scientists led by Haruichi Washimi (Kyushu University, Japan and CSPAR, University of Alabama-Huntsville) argues that models of the heliosphere can help explain this behavior. Because the heliopause location is controlled by factors that vary on many spatial and temporal scales, Washimiand collaborators turn to three-dimensional, time-dependent magnetohydrodynamics simulations of the heliosphere. In particular, they investigate how the position of the heliopause along the trajectories of Voyager 1 and Voyager 2 changes over time.Modeled location of the heliopause along the paths of Voyagers 1 (blue) and 2 (orange). Click for a closer look. The red star indicates the location at which Voyager

  11. i-Locate - Indoor/Outdoor location and Asset Management through Open Data

    Directory of Open Access Journals (Sweden)

    Claudio Eccher

    2015-02-01

    Full Text Available Studi recenti hanno evidenziato che, in media, trascorriamo circa il 90% del nostro tempo in ambienti chiusi e, spesso, non familiari. L’esigenza di localizzare/guidare persone o ogg etti in spazi sia esterni che interni (senza discontinuità tra esterno ed interno darà origine ad una serie di nuovi servizi di tipo LBS (Location-Based Services che potranno avere anche una notevole rilevanza economica.i-locate (Indoor / outdoor location and Asset Management Through open geodata is a project that aims to develop a set of tools and services based on geo location technologies based on open data for the location and management of objects in indoor and outdoor spaces. The tools are intended both to citizens who use their smartphones to access services, aids to navigation from the front door to internal destinations to buildings (public office, clinic, shop, etc.. Obtaining any information available to support (code , unforeseen changes in the path, suggestions, etc., and professionals for specific activities that require the location of people, equipment, etc. i-locate to an intense use of GIS technologies for navigation and tracking "indoor" (indoor GIS, 3D GIS, to locate people (eg. Alzheimer's patients and their movements in areas not suited (geofencing to identify and track objects / portable equipment for their location, management and maintenance.

  12. i-Locate - Indoor/Outdoor location and Asset Management through Open Data

    Directory of Open Access Journals (Sweden)

    Claudio Eccher

    2015-02-01

    Full Text Available Studi recenti hanno evidenziato che, in media, trascorriamo circa il 90% del nostro tempo in ambienti chiusi e, spesso, non familiari. L’esigenza di localizzare/guidare persone o ogg etti in spazi sia esterni che interni (senza discontinuità tra esterno ed interno darà origine ad una serie di nuovi servizi di tipo LBS (Location-Based Services che potranno avere anche una notevole rilevanza economica. i-locate (Indoor / outdoor location and Asset Management Through open geodata is a project that aims to develop a set of tools and services based on geo location technologies based on open data for the location and management of objects in indoor and outdoor spaces. The tools are intended both to citizens who use their smartphones to access services, aids to navigation from the front door to internal destinations to buildings (public office, clinic, shop, etc.. Obtaining any information available to support (code , unforeseen changes in the path, suggestions, etc., and professionals for specific activities that require the location of people, equipment, etc. i-locate to an intense use of GIS technologies for navigation and tracking "indoor" (indoor GIS, 3D GIS, to locate people (eg. Alzheimer's patients and their movements in areas not suited (geofencing to identify and track objects / portable equipment for their location, management and maintenance.

  13. New spatial clustering-based models for optimal urban facility location considering geographical obstacles

    Science.gov (United States)

    Javadi, Maryam; Shahrabi, Jamal

    2014-03-01

    The problems of facility location and the allocation of demand points to facilities are crucial research issues in spatial data analysis and urban planning. It is very important for an organization or governments to best locate its resources and facilities and efficiently manage resources to ensure that all demand points are covered and all the needs are met. Most of the recent studies, which focused on solving facility location problems by performing spatial clustering, have used the Euclidean distance between two points as the dissimilarity function. Natural obstacles, such as mountains and rivers, can have drastic impacts on the distance that needs to be traveled between two geographical locations. While calculating the distance between various supply chain entities (including facilities and demand points), it is necessary to take such obstacles into account to obtain better and more realistic results regarding location-allocation. In this article, new models were presented for location of urban facilities while considering geographical obstacles at the same time. In these models, three new distance functions were proposed. The first function was based on the analysis of shortest path in linear network, which was called SPD function. The other two functions, namely PD and P2D, were based on the algorithms that deal with robot geometry and route-based robot navigation in the presence of obstacles. The models were implemented in ArcGIS Desktop 9.2 software using the visual basic programming language. These models were evaluated using synthetic and real data sets. The overall performance was evaluated based on the sum of distance from demand points to their corresponding facilities. Because of the distance between the demand points and facilities becoming more realistic in the proposed functions, results indicated desired quality of the proposed models in terms of quality of allocating points to centers and logistic cost. Obtained results show promising

  14. Allegheny County Dam Locations

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset shows the point locations of dams in Allegheny County. If viewing this description on the Western Pennsylvania Regional Data Center’s open data portal...

  15. Smart Location Mapping

    Science.gov (United States)

    The Smart Location Database, Access to Jobs and Workers via Transit, and National Walkability Index tools can help assess indicators related to the built environment, transit accessibility, and walkability.

  16. OAS :: Our Locations

    Science.gov (United States)

    the Human Resources of the OAS, including its organizational structure, each organizational unit's contract and travel control measure reports, the applicable procurement rules and regulations, and the Charter Organizational Charts Organizational List Authorities Our Locations Contact Us Telephone: +1 (202

  17. VT Hospital Site Locations

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) This data layer contains point locations of all major community, regional, comprehensive health, and healthcare provider hospitals in the state of...

  18. SGA Project Locations

    Data.gov (United States)

    Vermont Center for Geographic Information — The stream geomorphic assessment is a physical assessment competed by geomorphologists to determine the condition and sensitivity of a stream. The SGA locations...

  19. Waste Recovery Locations

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Locations where City residents are encouraged to drop off and dispose or recycle of unwanted materials. Information provided is subject to change. Please call ahead...

  20. Global Volcano Locations Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NGDC maintains a database of over 1,500 volcano locations obtained from the Smithsonian Institution Global Volcanism Program, Volcanoes of the World publication. The...

  1. USAID Activity Locations

    Data.gov (United States)

    US Agency for International Development — The USAID Activities dataset is a snapshot of activities supported by USAID including their geographical locations within countries at the time of the snapshot. The...

  2. Uranium Location Database

    Data.gov (United States)

    U.S. Environmental Protection Agency — A GIS compiled locational database in Microsoft Access of ~15,000 mines with uranium occurrence or production, primarily in the western United States. The metadata...

  3. Location-based Scheduling

    DEFF Research Database (Denmark)

    Andersson, Niclas; Christensen, Knud

    on the market. However, CPM is primarily an activity based method that takes the activity as the unit of focus and there is criticism raised, specifically in the case of construction projects, on the method for deficient management of construction work and continuous flow of resources. To seek solutions...... to the identified limitations of the CPM method, an alternative planning and scheduling methodology that includes locations is tested. Location-based Scheduling (LBS) implies a shift in focus, from primarily the activities to the flow of work through the various locations of the project, i.e. the building. LBS uses...... the graphical presentation technique of Line-of-balance, which is adapted for planning and management of work-flows that facilitates resources to perform their work without interruptions caused by other resources working with other activities in the same location. As such, LBS and Lean Construction share...

  4. 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).

  5. 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.

  6. AFRICOM: Does Location Matter?

    Science.gov (United States)

    2009-03-01

    Decision Model,” 242-244. 26 Susan Hesse Owen & Mark S. Daskin , “Strategic Facility Location: A Review,” European Journal of Operational Research...Susan Hesse & Mark S. Daskin . “Strategic Facility Location: A Review,” European Journal of Operational Research 111 (1998), 423-447. Paye-Layeleh...ES) N/ A 10. SPONSORING/MONITORING AGENCY REPORT NUMBER 11. SUPPLEMENTARY NOTES The views expressed in this thesis are those of the author and

  7. Indoor Positioning with Radio Location Fingerprinting

    DEFF Research Database (Denmark)

    Kjærgaard, Mikkel Baun

    . A promising indoor positioning technique is radio-based location ngerprinting, having the major advantage of exploiting already existing radio infrastructures, like IEEE 802.11 or GSM, which avoids extra deployment costs and eort. The research goal of this thesis is to address the limitations of current...... indoor location ngerprinting systems. In particular the aim is to advance location ngerprinting techniques for the challenges of handling heterogeneous clients, scalability to many clients, and interference between communication and positioning. The wireless clients used for location ngerprinting...... are heterogeneous even when only considering clients for the same technology. The heterogeneity is due to dierent radios, antennas, and rmwares causing measurements for location ngerprinting not to be directly comparable among clients. Heterogeneity is a challenge for location ngerprinting because it severely...

  8. Allocation and Location of Transport Logistics Centres

    Directory of Open Access Journals (Sweden)

    D. Mocková

    2010-01-01

    Full Text Available The facility allocation problem sets out to determine the optimal number of facilities to be opened. Based on multiple criteria evaluation, the optimal location of the facilities is usually solved subsequently. Several considerations, e.g. technical parameters, costs and finance must be taken into account. Economic analysis is carried out on the basis of the specific instance of the problem.Let us assume that the number of potentially located facilities is known. Then the problem of the optimal location of a given number of facilities in a network is referred to as the facility location problem. The solution to the problem is a set of facilities optimally located in an area such that this area is fully covered by the required services that the facilities provide. An example of a real-life problem of this type is the location of logistics centers. 

  9. On English Locative Subjects

    Directory of Open Access Journals (Sweden)

    Gabriela Brůhová

    2017-07-01

    Full Text Available The paper analyses English sentences with thematic locative subjects. These subjects were detected as translation counterparts of Czech sentenceinitial locative adverbials realized by prepositional phrases with the prepositions do (into, na (on, v/ve (in, z/ze (from complemented by a noun. In the corresponding English structure, the initial scene-setting adverbial is reflected in the thematic subject, which results in the locative semantics of the subject. The sentences are analysed from syntactic, semantic and FSP aspects. From the syntactic point of view, we found five syntactic patterns of the English sentences with a locative subject (SV, SVA, SVO, SVpassA and SVCs that correspond to Czech sentences with initial locative adverbials. On the FSP level the paper studies the potential of the sentences to implement the Presentation or Quality Scale. Since it is the “semantic content of the verb that actuates the presentation semantics of the sentence” (Duškova, 2015a: 260, major attention is paid to the syntactic-semantic structure of the verb. The analysis of the semantics of the English sentences results in the identification of two semantic classes of verbs which co-occur with the English locative subject.

  10. A PROCEDURE FOR DETERMINING OPTIMAL FACILITY LOCATION AND SUB-OPTIMAL POSITIONS

    Directory of Open Access Journals (Sweden)

    P.K. Dan

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: This research presents a methodology for determining the optimal location of a new facility, having physical flow interaction of various degrees with other existing facilities in the presence of barriers impeding the shortest flow-path as well as the sub-optimal iso-cost positions. It also determines sub-optimal iso-cost positions with additional cost or penalty for not being able to site it at the computed optimal point. The proposed methodology considers all types of quadrilateral barrier or forbidden region configurations to generalize and by-pass such impenetrable obstacles, and adopts a scheme of searching through the vertices of the quadrilaterals to determine the alternative shortest flow-path. This procedure of obstacle avoidance is novel. Software has been developed to facilitate computations for the search algorithm to determine the optimal and iso-cost co-ordinates. The test results are presented.

    AFRIKAANSE OPSOMMING: Die navorsing behandel ‘n procedure vir die bepaling van optimum stigtingsposisie vir ‘n onderneming met vloei vanaf ander bestaande fasiliteite in die teenwoordigheid van ‘n verskeidenheid van randvoorwaardes. Die prodedure lewer as resultaat suboptimale isokoste-stigtingsplekke met bekendmaking van die koste wat onstaan a.g.v. afwyking van die randvoorwaardlose optimum oplossingskoste, die prosedure maak gebruik van ‘n vindingryke soekmetode wat toegepas word op niersydige meerkundige voorstellings vir die bepaling van korste roetes wat versperring omseil. Die prosedure word onderskei deur programmatuur. Toetsresultate word voorgehou.

  11. Learning Paths to Offshore Outsourcing

    DEFF Research Database (Denmark)

    Maskell, Peter; Pedersen, Torben; Petersen, Bent

    A corporation’s offshore outsourcing may be seen as the result of a discrete, strategic decision taken in response to an increasing pressure from worldwide competition. However, empirical evidence of a representative cross-sector sample of international Danish firms indicates that offshore sourcing...... in low-cost countries is best described as a learning-by-doing process in which the offshore outsourcing of a corporation goes through a sequence of stages towards sourcing for innovation. Initially, a corporation’s outsourcing is driven by a desire for cost minimization. Over a period of time...... the outsourcing experience lessens the cognitive limitations of decision-makers as to the advantages that can be achieved through outsourcing in low-cost countries: the insourcer/vendor may not only offer cost advantages, but also quality improvement and innovation. The quality improvements that offshore...

  12. Design Change Model for Effective Scheduling Change Propagation Paths

    Science.gov (United States)

    Zhang, Hai-Zhu; Ding, Guo-Fu; Li, Rong; Qin, Sheng-Feng; Yan, Kai-Yin

    2017-09-01

    Changes in requirements may result in the increasing of product development project cost and lead time, therefore, it is important to understand how requirement changes propagate in the design of complex product systems and be able to select best options to guide design. Currently, a most approach for design change is lack of take the multi-disciplinary coupling relationships and the number of parameters into account integrally. A new design change model is presented to systematically analyze and search change propagation paths. Firstly, a PDS-Behavior-Structure-based design change model is established to describe requirement changes causing the design change propagation in behavior and structure domains. Secondly, a multi-disciplinary oriented behavior matrix is utilized to support change propagation analysis of complex product systems, and the interaction relationships of the matrix elements are used to obtain an initial set of change paths. Finally, a rough set-based propagation space reducing tool is developed to assist in narrowing change propagation paths by computing the importance of the design change parameters. The proposed new design change model and its associated tools have been demonstrated by the scheduling change propagation paths of high speed train's bogie to show its feasibility and effectiveness. This model is not only supportive to response quickly to diversified market requirements, but also helpful to satisfy customer requirements and reduce product development lead time. The proposed new design change model can be applied in a wide range of engineering systems design with improved efficiency.

  13. Accelerating Sequential Gaussian Simulation with a constant path

    Science.gov (United States)

    Nussbaumer, Raphaël; Mariethoz, Grégoire; Gravey, Mathieu; Gloaguen, Erwan; Holliger, Klaus

    2018-03-01

    Sequential Gaussian Simulation (SGS) is a stochastic simulation technique commonly employed for generating realizations of Gaussian random fields. Arguably, the main limitation of this technique is the high computational cost associated with determining the kriging weights. This problem is compounded by the fact that often many realizations are required to allow for an adequate uncertainty assessment. A seemingly simple way to address this problem is to keep the same simulation path for all realizations. This results in identical neighbourhood configurations and hence the kriging weights only need to be determined once and can then be re-used in all subsequent realizations. This approach is generally not recommended because it is expected to result in correlation between the realizations. Here, we challenge this common preconception and make the case for the use of a constant path approach in SGS by systematically evaluating the associated benefits and limitations. We present a detailed implementation, particularly regarding parallelization and memory requirements. Extensive numerical tests demonstrate that using a constant path allows for substantial computational gains with very limited loss of simulation accuracy. This is especially the case for a constant multi-grid path. The computational savings can be used to increase the neighbourhood size, thus allowing for a better reproduction of the spatial statistics. The outcome of this study is a recommendation for an optimal implementation of SGS that maximizes accurate reproduction of the covariance structure as well as computational efficiency.

  14. 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

  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. Hub location proplems under polyhedral demand uncertainty

    OpenAIRE

    Meraklı, Merve

    2015-01-01

    Cataloged from PDF version of thesis. Includes bibliographical references (leaves 69-74). Thesis (M.S.): Bilkent University, Department of Industrial Engineering, İhsan Doğramacı Bilkent University, 2015. Hubs are points of consolidation and transshipment in many-to-many distribution systems that bene t from economies of scale. In hub location problems, the aim is to locate hub facilities such that each pairwise demand is satis ed and the total cost is minimized. The problem...

  17. Competition and the Location of Overseas Assembly

    OpenAIRE

    Deborah Swenson

    2006-01-01

    How does international competition affect overseas outsourcing? While it is commonly believed that international competition enables firms to desert high cost countries in favor of low wage locations, the frequency of such responses may be reduced if the movement of outsourcing activities involves sunk costs. To put these factors in perspective, I study the production decisions of participants in the U.S. overseas assembly program (OAP). A number of interesting regularities emerge. First, the...

  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. Tax policy can change the production path: A model of optimal oil extraction in Alaska

    International Nuclear Information System (INIS)

    Leighty, Wayne; Lin, C.-Y. Cynthia

    2012-01-01

    We model the economically optimal dynamic oil production decisions for seven production units (fields) on Alaska's North Slope. We use adjustment cost and discount rate to calibrate the model against historical production data, and use the calibrated model to simulate the impact of tax policy on production rate. We construct field-specific cost functions from average cost data and an estimated inverse production function, which incorporates engineering aspects of oil production into our economic modeling. Producers appear to have approximated dynamic optimality. Consistent with prior research, we find that changing the tax rate alone does not change the economically optimal oil production path, except for marginal fields that may cease production. Contrary to prior research, we find that the structure of tax policy can be designed to affect the economically optimal production path, but at a cost in net social benefit. - Highlights: ► We model economically optimal dynamic oil production decisions for 7 Alaska fields. ► Changing tax rate alone does not alter the economically optimal oil production path. ► But change in tax structure can affect the economically optimal oil production path. ► Tax structures that modify the optimal production path reduce net social benefit. ► Field-specific cost functions and inverse production functions are estimated

  1. Turbine steam path replacement at the Grafenrheinfeld Nuclear Power Station

    International Nuclear Information System (INIS)

    Weschenfelder, K.D.; Oeynhausen, H.; Bergmann, D.; Hosbein, P.; Termuehlen, H.

    1994-01-01

    In the last few years, replacement of old vintage steam turbine flow path components has been well established as a valid approach to improve thermal performance of aged turbines. In nuclear power plants, performance improvement is generally achieved only by design improvements since performance deterioration of old units is minor or nonexistent. With fossil units operating over decades loss in performance is an additional factor which can be taken into account. Such loss of performance can be caused by deposits, solid particle erosion, loss of shaft and inter-stage seal strips, etc. Improvement of performance is typically guaranteed as output increases for operation at full load. This value can be evaluated as a direct gain in unit capacity without fuel or steam supply increase. Since fuel intake does not change, the relative improvement of the net plant heat rate or efficiency is equal to the relative increase in output. The heat rate improvement is achieved not only at full load but for the entire load range. Such heat rate improvement not only moves a plant up on the load dispatch list increasing its capacity factor, but also extensive fuel savings can pay off for the investment cost of new steam path components. Another important factor is that quite often older turbine designs show a deterioration of their reliability and need costly repairs. With new flow path components an aged steam turbine starts a new useful life

  2. Colloidal Quantum Dot Photovoltaics: A Path Forward

    KAUST Repository

    Kramer, Illan J.

    2011-11-22

    Colloidal quantum dots (CQDs) offer a path toward high-efficiency photovoltaics based on low-cost materials and processes. Spectral tunability via the quantum size effect facilitates absorption of specific wavelengths from across the sun\\'s broad spectrum. CQD materials\\' ease of processing derives from their synthesis, storage, and processing in solution. Rapid advances have brought colloidal quantum dot photovoltaic solar power conversion efficiencies of 6% in the latest reports. These achievements represent important first steps toward commercially compelling performance. Here we review advances in device architecture and materials science. We diagnose the principal phenomenon-electronic states within the CQD film band gap that limit both current and voltage in devices-that must be cured for CQD PV devices to fulfill their promise. We close with a prescription, expressed as bounds on the density and energy of electronic states within the CQD film band gap, that should allow device efficiencies to rise to those required for the future of the solar energy field. © 2011 American Chemical Society.

  3. General minisum circle location

    DEFF Research Database (Denmark)

    Körner, Mark; Brimberg, Jack; Juel, Henrik

    2009-01-01

    In our paper we approximate a set of given points by a general circle. More precisely, we consider the problem of locating and scaling the unit ball of some given norm k1 with respect to xed points on the plane such that the sum of weighted distances between the circle and the xed points is minim......In our paper we approximate a set of given points by a general circle. More precisely, we consider the problem of locating and scaling the unit ball of some given norm k1 with respect to xed points on the plane such that the sum of weighted distances between the circle and the xed points...

  4. Location-based games

    DEFF Research Database (Denmark)

    Ejsing-Duun, Stine

    In this dissertation, it is explored which prerequisites are necessary in location-based games (LBGs) to make meaningful the meeting between players and spatiality with an emphasis on physical locations. Throughout the dissertation, it has been shown that LBGs affect players’ perception of and be...... possible. The practical contribution is my creation of the LBG Visions of Sara. People continue to play this game in Odense more than two years after its launch, and DJEEO uses it as a showcase, enabling the company to sell similar LBGs....

  5. Virtual Fiber Networking and Impact of Optical Path Grooming on Creating Efficient Layer One Services

    Science.gov (United States)

    Naruse, Fumisato; Yamada, Yoshiyuki; Hasegawa, Hiroshi; Sato, Ken-Ichi

    This paper presents a novel “virtual fiber” network service that exploits wavebands. This service provides virtual direct tunnels that directly convey wavelength paths to connect customer facilities. To improve the resource utilization efficiency of the service, a network design algorithm is developed that can allow intermediate path grooming at limited nodes and can determine the best node location. Numerical experiments demonstrate the effectiveness of the proposed service architecture.

  6. 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.

  7. 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.

  8. Managing Ongoing EVSE Costs

    Energy Technology Data Exchange (ETDEWEB)

    Hodge, Cabell [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-05

    The costs associated with EVSE begin with picking the best location and unit for the job, but they continue with electricity and network charges through the life of your vehicle. This presentation tells how to balance electricity demand charges and network management costs through smart planning at your program's inception.

  9. Low Complexity Transmission Scheme with Full Diversity for Two-Path Relay Networks

    KAUST Repository

    Fareed, Muhammad Mehboob

    2014-01-06

    In this work, we present a new low complexity scheme for two-path relay network to harvest maximum achievable diversity. We analyze the performance of the newly proposed two-path relay network by calculating the symbol error rate (SER) for arbitrary location of relays. It is shown that with this newly proposed scheme, two-path relay networks can mimic a 2x2 multiple-input mulitple-output (MIMO) system and achieve full diversity order of four. Simulations results are provided to verify and illustrate the analytical results.

  10. Low Complexity Transmission Scheme with Full Diversity for Two-Path Relay Networks

    KAUST Repository

    Fareed, Muhammad Mehboob; Yang, Hong-Chuan; Alouini, Mohamed-Slim

    2014-01-01

    In this work, we present a new low complexity scheme for two-path relay network to harvest maximum achievable diversity. We analyze the performance of the newly proposed two-path relay network by calculating the symbol error rate (SER) for arbitrary location of relays. It is shown that with this newly proposed scheme, two-path relay networks can mimic a 2x2 multiple-input mulitple-output (MIMO) system and achieve full diversity order of four. Simulations results are provided to verify and illustrate the analytical results.

  11. Quantitative analytical hierarchy process to marketing store location selection

    OpenAIRE

    Harwati; Utami Intan

    2018-01-01

    The selection of Store to market the product is belong to Multi Criteria Decision Making problem. The criteria used have conflict of interest with each other to produce an optimal location. This research uses four important criteria to select new location of marketing store appropriate with the references: distance to location, competition level with competitor, number of potential customer, and location rent cost. Quantitative data is used to determine the optimum location with AHP method. Q...

  12. Design of Active N-path Filters

    NARCIS (Netherlands)

    Darvishi, M.; van der Zee, Ronan A.R.; Nauta, Bram

    2013-01-01

    A design methodology for synthesis of active N-path bandpass filters is introduced. Based on this methodology, a 0.1-to-1.2 GHz tunable 6th-order N-path channel-select filter in 65 nm LP CMOS is introduced. It is based on coupling N-path filters with gyrators, achieving a “flat‿ passband shape and

  13. Evaluating Trajectory Queries over Imprecise Location Data

    DEFF Research Database (Denmark)

    Xie, Scott, Xike; Cheng, Reynold; Yiu, Man Lung

    2012-01-01

    Trajectory queries, which retrieve nearby objects for every point of a given route, can be used to identify alerts of potential threats along a vessel route, or monitor the adjacent rescuers to a travel path. However, the locations of these objects (e.g., threats, succours) may not be precisely...... obtained due to hardware limitations of measuring devices, as well as the constantly-changing nature of the external environment. Ignoring data uncertainty can render low query quality, and cause undesirable consequences such as missing alerts of threats and poor response time in rescue operations. Also......, the query is quite time-consuming, since all the points on the trajectory are considered. In this paper, we study how to efficiently evaluate trajectory queries over imprecise location data, by proposing a new concept called the u-bisector. In general, the u-bisector is an extension of bisector to handle...

  14. Optimal hub location in pipeline networks

    Energy Technology Data Exchange (ETDEWEB)

    Dott, D.R.; Wirasinghe, S.C.; Chakma, A. [Univ. of Calgary, Alberta (Canada)

    1996-12-31

    This paper discusses optimization strategies and techniques for the location of natural gas marketing hubs in the North American gas pipeline network. A hub is a facility at which inbound and outbound network links meet and freight is redirected towards their destinations. Common examples of hubs used in the gas pipeline industry include gas plants, interconnects and market centers. Characteristics of the gas pipeline industry which are relevant to the optimization of transportation costs using hubs are presented. Allocation techniques for solving location-allocation problems are discussed. An outline of the research in process by the authors in the field of optimal gas hub location concludes the paper.

  15. The Czech Locative Chameleon

    Directory of Open Access Journals (Sweden)

    Tarald Taraldsen

    2007-12-01

    Full Text Available We show that under certain circumstances, the Czech locative prepositions (LOC show up as directional prepositions (DIR and vice versa, (under different circumstances the Czech DIR PPs show up as LOC. We argue that such a chameleon life of the PPs is structurally dependent.

  16. Immigrants' location preferences

    DEFF Research Database (Denmark)

    Damm, Anna Piil

    This paper exploits a spatial dispersal policy for refugee immigrants to estimate the importance of local and regional factors for refugees' location preferences. The main results of a mixed proportional hazard competing risks model are that placed refugees react to high regional unemployment...

  17. Tracking, say, SKYPE Locations

    Indian Academy of Sciences (India)

    First page Back Continue Last page Graphics. Tracking, say, SKYPE Locations. Real Time Communication: Peer-to-Peer (P2P). Datagram flows between the two conversing partners; Exposes the IP addresses of all the participants to one another. If A knows B's VoIP ID, she can establish a call with Bob & obtain his current ...

  18. Spatiotemporal AED Location Optimization

    NARCIS (Netherlands)

    Chan, Timothy C.Y.; Sun, Christopher L.F.; Demirtas, Derya; Morrison, Laurie J.; Brooks, Steven C.

    2015-01-01

    Background: Mathematical optimization can be used to plan future AED placement to maximize out-of-hospital cardiac arrest (OHCA) coverage. Many public access AEDs are placed in locations without 24/7 access. AED coverage can be overestimated unless temporal availability is considered. Objective: To

  19. Location of New Firms

    DEFF Research Database (Denmark)

    Backman, Mikaela; Karlsson, Charlie

    2017-01-01

    characteristics, such as the commuting experience. Our results show that commuting influences the firm location choice. The probability of establishing a firm in the work municipality increases if the entrepreneur is a commuter, holding constant the type of region and unobservable and observable individual...

  20. Path integrals and geometry of trajectories

    International Nuclear Information System (INIS)

    Blau, M.; Keski-Vakkuri, E.; Niemi, A.J.

    1990-01-01

    A geometrical interpretation of path integrals is developed in the space of trajectories. This yields a supersymmetric formulation of a generic path integral, with the supersymmetry resembling the BRST supersymmetry of a first class constrained system. If the classical equation of motion is a Killing vector field in the space of trajectories, the supersymmetry localizes the path integral to classical trajectories and the WKB approximation becomes exact. This can be viewed as a path integral generalization of the Duistermaat-Heckman theorem, which states the conditions for the exactness of the WKB approximation for integrals in a compact phase space. (orig.)

  1. Path integrals for arbitrary canonical transformations

    International Nuclear Information System (INIS)

    Oliveira, L.A.R. de.

    1980-01-01

    Some aspects of the path integral formulation of quantum mechanics are studied. This formalism is generalized to arbitrary canonical transformations, by means of an association between path integral probalility amplitudes and classical generators of transformations, analogous to the usual Hamiltonian time development phase space expression. Such association turns out to be equivalent to the Weyl quantization rule, and it is also shown that this formalism furnishes a path integral representation for a Lie algebra of a given set of classical generators. Some physical considerations about the path integral quantization procedure and about the relationship between classical and quantum dynamical structures are also discussed. (Author) [pt

  2. Techniques and applications of path integration

    CERN Document Server

    Schulman, L S

    2005-01-01

    A book of techniques and applications, this text defines the path integral and illustrates its uses by example. It is suitable for advanced undergraduates and graduate students in physics; its sole prerequisite is a first course in quantum mechanics. For applications requiring specialized knowledge, the author supplies background material.The first part of the book develops the techniques of path integration. Topics include probability amplitudes for paths and the correspondence limit for the path integral; vector potentials; the Ito integral and gauge transformations; free particle and quadra

  3. Symbolic PathFinder v7

    DEFF Research Database (Denmark)

    Luckow, Kasper Søe; Păsăreanu, Corina

    2014-01-01

    We describe Symbolic PathFinder v7 in terms of its updated design addressing the changes of Java PathFinder v7 and of its new optimization when computing path conditions. Furthermore, we describe the Symbolic Execution Tree Extension; a newly added feature that allows for outputting the symbolic...... execution tree that characterizes the execution paths covered during symbolic execution. The new extension can be tailored to the needs of subsequent analyses/processing facilities, and we demonstrate this by presenting SPF-Visualizer, which is a tool for customizable visualization of the symbolic execution...

  4. Reachability by paths of bounded curvature in a convex polygon

    KAUST Repository

    Ahn, Heekap; Cheong, Otfried; Matoušek, Jiřǐ; Vigneron, Antoine E.

    2012-01-01

    Let B be a point robot moving in the plane, whose path is constrained to forward motions with curvature at most 1, and let P be a convex polygon with n vertices. Given a starting configuration (a location and a direction of travel) for B inside P, we characterize the region of all points of P that can be reached by B, and show that it has complexity O(n). We give an O(n2) time algorithm to compute this region. We show that a point is reachable only if it can be reached by a path of type CCSCS, where C denotes a unit circle arc and S denotes a line segment. © 2011 Elsevier B.V.

  5. Impulsive noise suppression in color images based on the geodesic digital paths

    Science.gov (United States)

    Smolka, Bogdan; Cyganek, Boguslaw

    2015-02-01

    In the paper a novel filtering design based on the concept of exploration of the pixel neighborhood by digital paths is presented. The paths start from the boundary of a filtering window and reach its center. The cost of transitions between adjacent pixels is defined in the hybrid spatial-color space. Then, an optimal path of minimum total cost, leading from pixels of the window's boundary to its center is determined. The cost of an optimal path serves as a degree of similarity of the central pixel to the samples from the local processing window. If a pixel is an outlier, then all the paths starting from the window's boundary will have high costs and the minimum one will also be high. The filter output is calculated as a weighted mean of the central pixel and an estimate constructed using the information on the minimum cost assigned to each image pixel. So, first the costs of optimal paths are used to build a smoothed image and in the second step the minimum cost of the central pixel is utilized for construction of the weights of a soft-switching scheme. The experiments performed on a set of standard color images, revealed that the efficiency of the proposed algorithm is superior to the state-of-the-art filtering techniques in terms of the objective restoration quality measures, especially for high noise contamination ratios. The proposed filter, due to its low computational complexity, can be applied for real time image denoising and also for the enhancement of video streams.

  6. Ranking shortest paths in Stochastic time-denpendent networks

    DEFF Research Database (Denmark)

    Nielsen, Lars Relund; Andersen, Kim Allan; Pretolani, Daniele

    A substantial amount of research has been devoted to the shortest path problem in networks where travel times are stochastic or (deterministic and) time-dependent. More recently, a growing interest has been attracted by networks that are both stochastic and time-dependent. In these networks, the ...... present a computational comparison of time-adaptive and a priori route choices, pointing out the effect of travel time and cost distributions. The reported results show that, under realistic distributions, our solution methods are effective.......A substantial amount of research has been devoted to the shortest path problem in networks where travel times are stochastic or (deterministic and) time-dependent. More recently, a growing interest has been attracted by networks that are both stochastic and time-dependent. In these networks...

  7. K shortest paths in stochastic time-dependent networks

    DEFF Research Database (Denmark)

    Nielsen, Lars Relund; Pretolani, Daniele; Andersen, Kim Allan

    2004-01-01

    A substantial amount of research has been devoted to the shortest path problem in networks where travel times are stochastic or (deterministic and) time-dependent. More recently, a growing interest has been attracted by networks that are both stochastic and time-dependent. In these networks, the ...... present a computational comparison of time-adaptive and a priori route choices, pointing out the effect of travel time and cost distributions. The reported results show that, under realistic distributions, our solution methods are effective.......A substantial amount of research has been devoted to the shortest path problem in networks where travel times are stochastic or (deterministic and) time-dependent. More recently, a growing interest has been attracted by networks that are both stochastic and time-dependent. In these networks...

  8. Regular paths in SparQL: querying the NCI Thesaurus.

    Science.gov (United States)

    Detwiler, Landon T; Suciu, Dan; Brinkley, James F

    2008-11-06

    OWL, the Web Ontology Language, provides syntax and semantics for representing knowledge for the semantic web. Many of the constructs of OWL have a basis in the field of description logics. While the formal underpinnings of description logics have lead to a highly computable language, it has come at a cognitive cost. OWL ontologies are often unintuitive to readers lacking a strong logic background. In this work we describe GLEEN, a regular path expression library, which extends the RDF query language SparQL to support complex path expressions over OWL and other RDF-based ontologies. We illustrate the utility of GLEEN by showing how it can be used in a query-based approach to defining simpler, more intuitive views of OWL ontologies. In particular we show how relatively simple GLEEN-enhanced SparQL queries can create views of the OWL version of the NCI Thesaurus that match the views generated by the web-based NCI browser.

  9. Modeling of tool path for the CNC sheet cutting machines

    Science.gov (United States)

    Petunin, Aleksandr A.

    2015-11-01

    In the paper the problem of tool path optimization for CNC (Computer Numerical Control) cutting machines is considered. The classification of the cutting techniques is offered. We also propose a new classification of toll path problems. The tasks of cost minimization and time minimization for standard cutting technique (Continuous Cutting Problem, CCP) and for one of non-standard cutting techniques (Segment Continuous Cutting Problem, SCCP) are formalized. We show that the optimization tasks can be interpreted as discrete optimization problem (generalized travel salesman problem with additional constraints, GTSP). Formalization of some constraints for these tasks is described. For the solution GTSP we offer to use mathematical model of Prof. Chentsov based on concept of a megalopolis and dynamic programming.

  10. What Path Do We Take?

    OpenAIRE

    BUTCHER, LOLA

    2008-01-01

    As existing biologics gain indications and new drugs make it to market, the array of choices makes it challenging to pick the right treatment for a given patient. Clinical effectiveness is the most important factor, but at the policy level, cost has to enter the discussion. Where?

  11. Hippocampal “Time Cells”: Time versus Path Integration

    Science.gov (United States)

    Kraus, Benjamin J.; Robinson, Robert J.; White, John A.; Eichenbaum, Howard; Hasselmo, Michael E.

    2014-01-01

    SUMMARY Recent studies have reported the existence of hippocampal “time cells,” neurons that fire at particular moments during periods when behavior and location are relatively constant. However, an alternative explanation of apparent time coding is that hippocampal neurons “path integrate” to encode the distance an animal has traveled. Here, we examined hippocampal neuronal firing patterns as rats ran in place on a treadmill, thus “clamping” behavior and location, while we varied the treadmill speed to distinguish time elapsed from distance traveled. Hippocampal neurons were strongly influenced by time and distance, and less so by minor variations in location. Furthermore, the activity of different neurons reflected integration over time and distance to varying extents, with most neurons strongly influenced by both factors and some significantly influenced by only time or distance. Thus, hippocampal neuronal networks captured both the organization of time and distance in a situation where these dimensions dominated an ongoing experience. PMID:23707613

  12. The First Paleomagnetic Polar Wander Path

    Science.gov (United States)

    Creer, K. M.

    2004-12-01

    At the end of 1952, having completed my work on the Cambridge astatic magnetometer, I was motivated to embark on a "Preliminary Paleomagnetic Survey of Rocks from the British Isles" by exciting results obtained by two fellow research students:- Jan Hospers' proposal of the axial dipole hypothesis and Ted Irving's discovery of strongly oblique Pre-Cambrian paleomagnetic directions, substantiated by the oblique Triassic directions obtained by John Clegg's group. Geologists advised me to collect from palaeontologically well dated rock formations. But these turned out to be very weakly magnetized and thereafter I concentrated on purple and dark red coloured rock formations. By the end of July 1954 I had compiled a table of nine Period-mean paleomagnetic directions spanning the last 600 Myr. I passed a copy to Keith Runcorn to include in a talk (co-authors Creer and Irving) scheduled for the August 1954 Rome Assembly of IAGA. Meanwhile, background reading took me to Gutenberg's "Internal Constitution of the Earth (1951)" where I came across (Fig 12) paths of the north pole proposed by Kreichgauer (1902) and by Koppen and Wegener (1924). This prompted me to calculate a paleomagnetic polar wander path. I presented this at the Annual Meeting of the British Association for the Advancement of Science held at Oxford on September 8th. An artist's representation of it was published in Time Magazine of September 24th 1954 where the accompanying text records that I stressed that similar work on other continents would be necessary to distinguish whether the continents had drifted independently or whether the sole mechanism had been polar wander. On my return to Cambridge, Maurice Hill informally suggested that I should indicate precision, so for each pole I calculated semi-major and minor axes of the ellipse of confidence corresponding to the radius of confidence of each mean direction. These were shown in my Ph.D. thesis, where also I calculated a paleomagnetic pole for John

  13. Hub location problems in transportation networks

    DEFF Research Database (Denmark)

    Gelareh, Shahin; Nickel, Stefan

    2011-01-01

    In this paper we propose a 4-index formulation for the uncapacitated multiple allocation hub location problem tailored for urban transport and liner shipping network design. This formulation is very tight and most of the tractable instances for MIP solvers are optimally solvable at the root node....... also introduce fixed cost values for Australian Post (AP) dataset....

  14. Joint modeling of constrained path enumeration and path choice behavior: a semi-compensatory approach

    DEFF Research Database (Denmark)

    Kaplan, Sigal; Prato, Carlo Giacomo

    2010-01-01

    A behavioural and a modelling framework are proposed for representing route choice from a path set that satisfies travellers’ spatiotemporal constraints. Within the proposed framework, travellers’ master sets are constructed by path generation, consideration sets are delimited according to spatio...

  15. Decision paths in complex tasks

    Science.gov (United States)

    Galanter, Eugene

    1991-01-01

    Complex real world action and its prediction and control has escaped analysis by the classical methods of psychological research. The reason is that psychologists have no procedures to parse complex tasks into their constituents. Where such a division can be made, based say on expert judgment, there is no natural scale to measure the positive or negative values of the components. Even if we could assign numbers to task parts, we lack rules i.e., a theory, to combine them into a total task representation. We compare here two plausible theories for the amalgamation of the value of task components. Both of these theories require a numerical representation of motivation, for motivation is the primary variable that guides choice and action in well-learned tasks. We address this problem of motivational quantification and performance prediction by developing psychophysical scales of the desireability or aversiveness of task components based on utility scaling methods (Galanter 1990). We modify methods used originally to scale sensory magnitudes (Stevens and Galanter 1957), and that have been applied recently to the measure of task 'workload' by Gopher and Braune (1984). Our modification uses utility comparison scaling techniques which avoid the unnecessary assumptions made by Gopher and Braune. Formula for the utility of complex tasks based on the theoretical models are used to predict decision and choice of alternate paths to the same goal.

  16. Practicality of diversion path analysis

    International Nuclear Information System (INIS)

    Murphey, W.M.; Schleter, J.C.

    1974-07-01

    One can define the safeguards system for nuclear material as the set of all protective actions taken to prevent or to deter attempts to divert nuclear material to unauthorized use. Maintenance of effective safeguards requires a program for routine assessment of plant safeguards systems in terms of their capabilities to satisfy safeguards aims. Plant internal control systems provide capabilities for detection of unprevented diversion and can provide assurance that diversion has not occurred. A procedure called Diversion Path Analysis (DPA) enables routine assessment of the capabilities of internal control systems in this regard and identification of safeguards problem areas in a plant. A framework for safeguards system design is also provided which will allow flexibility to accommodate individual plant circumstances while maintaining acceptable diversion detection capability. The steps of the procedure are described and the practicality of the analytical method is shown by referring to a demonstration test for a high throughput process where plant personnel were major participants. The boundary conditions for the demonstration case are given, along with some conclusions about the general procedure. (U.S.)

  17. Inked Careers: Tattooing Professional Paths

    Directory of Open Access Journals (Sweden)

    Gabriela DeLuca

    2016-12-01

    Full Text Available The concept of career has an interdisciplinary and historical constitution, which includes persons, groups, organizations and society. Given that, we aim to deepen the interactionist notion of career from the understanding of a deviant path, supported by a theory and a method appropriated to the cited call for interdisciplinary approaches. Dilemmas (Hughes, 1958 and conflicts (Hughes, 1937 emerged as important analytical categories. Although necessary, these two concepts were not sufficient to contemplate analyses in their entirety. For this reason we conceptualized a third possibility of controversy during a career: the inquiries. The study followed the Narrative method to analyze objective and subjective changes during a tattoo artist’s career through interviews and informal conversations carried out over 22 months. The discussion presents three main contributions. Theoretically, a new understanding of the concept of careers, linking past, present and future and the idea of non-linearity of experienced and envisioned careers. Methodologically, suggesting orientations for future career studies such as the use of turning points as a methodological tool and the investigation of deviant fields. Finally, our defense of the interactionist perspective as suitable for career studies, since it allows the investigation of deviant elements.

  18. Aquatic Nuisance Species Locator

    Science.gov (United States)

    Data in this map has been collected by the United States Geological Survey's Nonindigenous Aquatic Species program located in Gainesville, Florida (http://nas.er.usgs.gov/default.aspx). This dataset may have some inaccuracies and is only current to June 15, 2012. The species identified in this dataset are not inclusive of all aquatic nuisance species, but rather a subset identified to be at risk for transport by recreational activities such as boating and angling. Additionally, the locations where organisims have been identified are also not inclusive and should be treated as a guide. Organisms are limited to the following: American bullfrog, Asian clam, Asian shore crab, Asian tunicate, Australian spotted jellyfish, Chinese mitten crab, New Zealand mudsnail, Colonial sea squirt, Alewife, Bighead carp, Black carp, Flathead catfish, Grass carp, Green crab, Lionfish, Northern snakehead, Quagga mussel, Round Goby, Ruffe, Rusty crayfish, Sea lamprey, Silver carp, Spiny water flea, Veined rapa whelk, Zebra mussel

  19. Locating underground uranium deposits

    International Nuclear Information System (INIS)

    Felice, P.E.

    1979-01-01

    Underground uranium deposits are located by placing wires of dosimeters each about 5 to 18 mg/cm 2 thick underground in a grid pattern. Each dosimeter contains a phosphor which is capable of storing the energy of alpha particles. In each pair one dosimeter is shielded from alpha particles with more than 18 mg/cm 2 thick opaque material but not gamma and beta rays and the other dosimeter is shielded with less than 1 mg/cm 2 thick opaque material to exclude dust. After a period underground the dosimeters are heated which releases the stored energy as light. The amount of light produced from the heavily shielded dosimeter is subtracted from the amount of light produced from the thinly shielded dosimeter to give an indication of the location and quantity of uranium underground

  20. Web cache location

    Directory of Open Access Journals (Sweden)

    Boffey Brian

    2004-01-01

    Full Text Available Stress placed on network infrastructure by the popularity of the World Wide Web may be partially relieved by keeping multiple copies of Web documents at geographically dispersed locations. In particular, use of proxy caches and replication provide a means of storing information 'nearer to end users'. This paper concentrates on the locational aspects of Web caching giving both an overview, from an operational research point of view, of existing research and putting forward avenues for possible further research. This area of research is in its infancy and the emphasis will be on themes and trends rather than on algorithm construction. Finally, Web caching problems are briefly related to referral systems more generally.

  1. A Socio-Ecological Approach to GIS Least-Cost Modelling for Regional Mining Infrastructure Planning: A Case Study from South-East Sulawesi, Indonesia

    Directory of Open Access Journals (Sweden)

    Alex M. Lechner

    2017-01-01

    Full Text Available Regional planning approaches to mining infrastructure aim to reduce the conflict associated with mining operations and existing land uses, such as urban areas and biodiversity conservation, as well as the cumulative impacts that occur offsite. In this paper, we describe a method for conducting Geographical Information System (GIS least-cost path and least-cost corridor analysis for linear mining infrastructure, such as roads. Least-cost path analysis identifies the optimal pathways between two locations as a function of the cost of traveling through different land use/cover types. In a case study from South-East Sulawesi, Indonesia, we identify potential linear networks for road infrastructure connecting mines, smelters, and ports. The method used interview data from government officials to characterise their orientation (perceived importance and positive/negative attitude toward the social and environmental factors associated with mining infrastructure. A cost-surface was constructed by integrating spatial layers representing the social and environmental factors to identify areas that should be avoided and areas that were compatible with linear infrastructure using the least-cost path analysis. We compared infrastructure scenario outputs from local and national government officials by the degree of spatial overlap and found broad spatial agreement for infrastructure corridors. We conclude by discussing this approach in relation to the wider social-ecological and mine planning literature and how quantitative approaches can reduce the conflict associated with infrastructure planning.

  2. Location based services

    OpenAIRE

    Doan, Cong Nam

    2015-01-01

    Mobile devices (tablets, smart phones, laptops) are proving themselves to be the main means of accessing information of the future. The embodiment of Recommender Systems (RSs) into mobile environments, as a matter of fact, has come about to serve as a way to solve the nuisances of data overwhelming. RSs' main advantage is their ability to allow users to find useful information according to the users' preferences and location. Even though they are not free of shortcoming such as the limitation...

  3. Location Intelligence Solutions

    International Nuclear Information System (INIS)

    Schmidt, D.

    2015-01-01

    Location Intelligence (LI) means using the spatial dimension of information as a key to support business processes. This spatial dimension has to be defined by geographic coordinates. Storing these spatial objects in a database allows for attaching a 'meaning' to them, like 'current position', 'border', 'building' or 'room'. Now the coordinates represent real-world objects, which can be relevant for the measurement, documentation, control or optimization of (parameters of) business processes aiming at different business objectives. But LI can only be applied, if the locations can be determined with an accuracy (in space and time) appropriate for the business process in consideration. Therefore the first step in any development of a LI solution is the analysis of the business process itself regarding its requirements for spatial and time resolution and accuracy. The next step is the detailed analysis of the surrounding conditions of the process: Does the process happen indoor and/or outdoor? Are there moving objects? If yes, how fast are they? How does the relevant environment look like? Is technical infrastructure available? Is the process restricted by regulations? As a result, a proper Location Detection Technology (LDT) has to be chosen in order to get reliable and accurate positions of the relevant objects. At the highly challenging conditions of the business processes IAEA inspectors are working with, the chosen LDTs have to deliver reliable positioning on ''room-level'' accuracy, even if there is no location enabling infrastructure in place, the objects (people) mostly are indoors and have to work under strong regulations. The presentation will give insights into innovative LI solutions based on technologies of different LDT providers. Pros and cons of combinations of different LDT (like multi- GNSS, IMU, camera, and human interaction based positioning) will be discussed from the

  4. Ammonia Leak Locator Study

    Science.gov (United States)

    Dodge, Franklin T.; Wuest, Martin P.; Deffenbaugh, Danny M.

    1995-01-01

    The thermal control system of International Space Station Alpha will use liquid ammonia as the heat exchange fluid. It is expected that small leaks (of the order perhaps of one pound of ammonia per day) may develop in the lines transporting the ammonia to the various facilities as well as in the heat exchange equipment. Such leaks must be detected and located before the supply of ammonia becomes critically low. For that reason, NASA-JSC has a program underway to evaluate instruments that can detect and locate ultra-small concentrations of ammonia in a high vacuum environment. To be useful, the instrument must be portable and small enough that an astronaut can easily handle it during extravehicular activity. An additional complication in the design of the instrument is that the environment immediately surrounding ISSA will contain small concentrations of many other gases from venting of onboard experiments as well as from other kinds of leaks. These other vapors include water, cabin air, CO2, CO, argon, N2, and ethylene glycol. Altogether, this local environment might have a pressure of the order of 10(exp -7) to 10(exp -6) torr. Southwest Research Institute (SwRI) was contracted by NASA-JSC to provide support to NASA-JSC and its prime contractors in evaluating ammonia-location instruments and to make a preliminary trade study of the advantages and limitations of potential instruments. The present effort builds upon an earlier SwRI study to evaluate ammonia leak detection instruments [Jolly and Deffenbaugh]. The objectives of the present effort include: (1) Estimate the characteristics of representative ammonia leaks; (2) Evaluate the baseline instrument in the light of the estimated ammonia leak characteristics; (3) Propose alternative instrument concepts; and (4) Conduct a trade study of the proposed alternative concepts and recommend promising instruments. The baseline leak-location instrument selected by NASA-JSC was an ion gauge.

  5. Academia Cuauhtli: (Re)Locating the Spiritual, if Crooked, Path to Social Justice

    Science.gov (United States)

    Valenzuela, Angela

    2017-01-01

    This essay doubles as a critique of the brutal violence visited upon the immigrant community in Austin, Texas, in the wake of Donald Trump's presidency, and a deeply personal account related to the establishment of Academia Cuauhtli, a language and culture revitalization project in Austin, Texas. It narrates our origins as a community-anchored,…

  6. Two Generations of Path Dependence in Economics?

    DEFF Research Database (Denmark)

    Madsen, Mogens Ove

    2010-01-01

    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...

  7. 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.

  8. Evaluation of Calcine Disposition Path Forward

    International Nuclear Information System (INIS)

    Birrer, S.A.; Heiser, M.B.

    2003-01-01

    This document describes an evaluation of the baseline and two alternative disposition paths for the final disposition of the calcine wastes stored at the Idaho Nuclear Technology and Engineering Center at the Idaho National Engineering and Environmental Laboratory. The pathways are evaluated against a prescribed set of criteria and a recommendation is made for the path forward

  9. Generalized measures and the Feynman path integral

    International Nuclear Information System (INIS)

    Maslov, V.P.; Chebotarev, A.M.

    1976-01-01

    Generalizations are obtained for the earlier results by the authors concerning the inclusion of the Feynmann path integral in the momentum representation into the general integration theory. Feynmann path integrals are considered which do not represent T-products. Generalized Feynmann measure in the configuration representation is introduced

  10. Approximate Shortest Homotopic Paths in Weighted Regions

    KAUST Repository

    Cheng, Siu-Wing; Jin, Jiongxin; Vigneron, Antoine; Wang, Yajun

    2010-01-01

    Let P be a path between two points s and t in a polygonal subdivision T with obstacles and weighted regions. Given a relative error tolerance ε ∈(0,1), we present the first algorithm to compute a path between s and t that can be deformed to P

  11. Paths and cycles in colored graphs

    NARCIS (Netherlands)

    Li, Xueliang; Zhang, Shenggui; Hurink, Johann L.; Pickl, Stefan; Broersma, Haitze J.; Faigle, U.

    2001-01-01

    Let G be an (edge-)colored graph. A path (cycle) is called monochromatic if all the edges of it have the same color, and is called heterochromatic if all the edges of it have different colors. In this note, some sufficient conditions for the existence of monochromatic and heterochromatic paths and

  12. Path Minima Queries in Dynamic Weighted Trees

    DEFF Research Database (Denmark)

    Davoodi, Pooya; Brodal, Gerth Stølting; Satti, Srinivasa Rao

    2011-01-01

    In the path minima problem on a tree, each edge is assigned a weight and a query asks for the edge with minimum weight on a path between two nodes. For the dynamic version of the problem, where the edge weights can be updated, we give data structures that achieve optimal query time\\todo{what about...

  13. Approximate shortest homotopic paths in weighted regions

    KAUST Repository

    Cheng, Siuwing; Jin, Jiongxin; Vigneron, Antoine E.; Wang, Yajun

    2012-01-01

    A path P between two points s and t in a polygonal subdivision T with obstacles and weighted regions defines a class of paths that can be deformed to P without passing over any obstacle. We present the first algorithm that, given P and a relative

  14. from synchronic variation to a grammaticalization path

    African Journals Online (AJOL)

    Kate H

    Abstract. The authors argue that the synchronic variation of cognate objects of weather verbs exhibited in six African languages of South Africa (Sepedi, Sesotho, Tshivenda, isiXhosa, Xitsonga, and. isiZulu) has a diachronic explanation, and may be represented as a grammaticalization path. This path gradually leads from ...

  15. Laser Cutting Tool Path Optimization

    OpenAIRE

    Dewil, Reginald; Cattrysse, Dirk; Vansteenwegen, Pieter

    2011-01-01

    Given a set of irregular parts nested on a metal sheet, minimize the total non- cutting time for the cutter head, cutting all the required elements and returning to the starting location. The problem is modeled as a generalized traveling sales- person problem with special precedence constraints. An initial feasible solution is generated and improved by local moves embedded in a tabu search framework. The proposed algorithm shows promising results in comparison with a commercial...

  16. Interference factors regarding the path of insertion of rotational-path removable partial dentures.

    Science.gov (United States)

    Huang, Chan-Te; Liu, Fang-Chun; Luk, Kwing-Chi

    2017-02-01

    The aims of this study were to evaluate the effect of the location of the rotational center and the morphology of teeth resulting in interference with the rotational path of insertion and to estimate when an interference test should be performed. A total of 400 dental radiograms of maxillary and mandibular first and second molars (100 for each position) were selected. The radiograms were used to hand-sketch the outlines on tracing paper. Then, an interference test was simulated using calipers. Mesial long occlusal rest seats with three different lengths were designed. A curve-simulated rotational path was drawn on the tracing paper showing the outline of a molar. If the curve was intersected by the mesial outline, interference was occurred. A total of 1200 tests were performed. A significant number of interference cases (18.5%, N = 400) occurred when the rotational center was placed at the most distal margin of the occlusal surface. The interference was reduced (2.75%, N = 400) but still present at the distal fourth of the occlusal surface. At the distal one-third of the occlusal surface, interference did not occur (0%, N = 400). There was a significant difference between the results of the three rotational centers (p < 0.0001). The interference test was not required for a rotational center at the distal third to half of the occlusal surface. However, if the length of the long occlusal rest extends beyond the distal third, an interference test is recommended before final impression. Copyright © 2017 Chang Gung University. Published by Elsevier B.V. All rights reserved.

  17. Critical path analysis in early stage of nuclear power project

    International Nuclear Information System (INIS)

    Xie Ahai

    2009-01-01

    The technical program and contract model as well as project management system and preliminary design defined in the early stage of nuclear power project are the key condition impact on the quality, schedule and cost of the nuclear power project. This paper, taking the CPR1000 coastal nuclear power station as an example, analyzes the critical path in the early stage of nuclear power project for five fields, i.e. licensing, design and procurement, site preparation, tender of construction contracts and construction preparation, and organization. (authors)

  18. Storage and Management of Open-pit Transportation Path

    Directory of Open Access Journals (Sweden)

    Jiusheng Du

    2013-07-01

    Full Text Available This paper is aiming at the actual demand of open-pit mine daily production scheduling and positioning monitoring. After extracting data from existing topographic maps and other information, it discusses the feasibility of using this data to establish thematic database. By considering the extensive application of GPS data, utilizing new spatial data types of SQL Server 2008 for data storage and management. Extracting data algorithms such as the node spatial data, the regional boundary and the path are implemented, then spatial data storage and management is also realized. It provides the basis for the production of decision-making and production cost savings.

  19. 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.

  20. 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.

  1. Rotational error in path integration: encoding and execution errors in angle reproduction.

    Science.gov (United States)

    Chrastil, Elizabeth R; Warren, William H

    2017-06-01

    Path integration is fundamental to human navigation. When a navigator leaves home on a complex outbound path, they are able to keep track of their approximate position and orientation and return to their starting location on a direct homebound path. However, there are several sources of error during path integration. Previous research has focused almost exclusively on encoding error-the error in registering the outbound path in memory. Here, we also consider execution error-the error in the response, such as turning and walking a homebound trajectory. In two experiments conducted in ambulatory virtual environments, we examined the contribution of execution error to the rotational component of path integration using angle reproduction tasks. In the reproduction tasks, participants rotated once and then rotated again to face the original direction, either reproducing the initial turn or turning through the supplementary angle. One outstanding difficulty in disentangling encoding and execution error during a typical angle reproduction task is that as the encoding angle increases, so does the required response angle. In Experiment 1, we dissociated these two variables by asking participants to report each encoding angle using two different responses: by turning to walk on a path parallel to the initial facing direction in the same (reproduction) or opposite (supplementary angle) direction. In Experiment 2, participants reported the encoding angle by turning both rightward and leftward onto a path parallel to the initial facing direction, over a larger range of angles. The results suggest that execution error, not encoding error, is the predominant source of error in angular path integration. These findings also imply that the path integrator uses an intrinsic (action-scaled) rather than an extrinsic (objective) metric.

  2. COST ANALYSIS OF THE LOCATION OF COLOMBIAN BIOFUELS PLANTS

    Directory of Open Access Journals (Sweden)

    ALEXANDRA EUGENIA DUARTE

    2012-01-01

    Full Text Available La localización de instalaciones es una decisión estratégica que impacta directamente la competitividad de la cadena de suministro. En este estudio, la localización de instalaciones y la red logística para la producción de biocombustibles en 7 plantas de biodiesel y 6 plantas de bioetanol, fueron analizadas para el caso Colombiano. La metodología propuesta proporciona un modelo de decisión para comparar la localización de instalaciones teniendo en cuenta el costo del producto y la red logística. Estudios técnicos y económicos preliminares fueron realizados utilizando el simulador de procesos Aspen Plus. La red logística se analizó utilizando un método de programación lineal que permitió comparar las ventajas y desventajas entre cada una de las plantas localizadas en diferentes ciudades del país. Factores relacionados con la ubicación, las materias primas, la cadena de suministro y la capacidad fueron determinantes en la decisión. Los resultados muestran que, para el caso del biodiesel, los menores costos se obtienen en Villavicencio, Bucaramanga y Santa Marta y para el caso del bioetanol en el Valle y en el Cauca.

  3. Location Privacy with Randomness Consistency

    Directory of Open Access Journals (Sweden)

    Wu Hao

    2016-10-01

    Full Text Available Location-Based Social Network (LBSN applications that support geo-location-based posting and queries to provide location-relevant information to mobile users are increasingly popular, but pose a location-privacy risk to posts. We investigated existing LBSNs and location privacy mechanisms, and found a powerful potential attack that can accurately locate users with relatively few queries, even when location data is well secured and location noise is applied. Our technique defeats previously proposed solutions including fake-location detection and query rate limits.

  4. Indoor Location Technologies

    CERN Document Server

    Goswami, Subrata

    2013-01-01

    Focusing on the special challenges posed by accurately pinpointing a location indoors, this volume reflects the distance we have come in the handful of decades since the germination of GPS technology. Not only can we locate a signal to within a meter’s accuracy, but we now have this technology in the most basic mobile phone. Tracing recent practical developments in positioning technology and in the market it supplies, the author examines the contributions of the varied research—in silicon, signal and image processing, radio communications and software—to a fast-evolving field. The book looks forward to a time when, in addition to directing your road journey, positioning systems can peer indoors and guide you to an available photocopier in your office building. Featuring standalone chapters each dealing with a specific aspect of the subject, including treatments of systems such as Zebra, Awarepoint, Aeroscout, IEEE 802.11, etc. This study has all the detail needed to get up to speed on a key modern techn...

  5. 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.

  6. Exploring chemical reaction mechanisms through harmonic Fourier beads path optimization.

    Science.gov (United States)

    Khavrutskii, Ilja V; Smith, Jason B; Wallqvist, Anders

    2013-10-28

    Here, we apply the harmonic Fourier beads (HFB) path optimization method to study chemical reactions involving covalent bond breaking and forming on quantum mechanical (QM) and hybrid QM∕molecular mechanical (QM∕MM) potential energy surfaces. To improve efficiency of the path optimization on such computationally demanding potentials, we combined HFB with conjugate gradient (CG) optimization. The combined CG-HFB method was used to study two biologically relevant reactions, namely, L- to D-alanine amino acid inversion and alcohol acylation by amides. The optimized paths revealed several unexpected reaction steps in the gas phase. For example, on the B3LYP∕6-31G(d,p) potential, we found that alanine inversion proceeded via previously unknown intermediates, 2-iminopropane-1,1-diol and 3-amino-3-methyloxiran-2-ol. The CG-HFB method accurately located transition states, aiding in the interpretation of complex reaction mechanisms. Thus, on the B3LYP∕6-31G(d,p) potential, the gas phase activation barriers for the inversion and acylation reactions were 50.5 and 39.9 kcal∕mol, respectively. These barriers determine the spontaneous loss of amino acid chirality and cleavage of peptide bonds in proteins. We conclude that the combined CG-HFB method further advances QM and QM∕MM studies of reaction mechanisms.

  7. Explore Stochastic Instabilities of Periodic Points by Transition Path Theory

    Science.gov (United States)

    Cao, Yu; Lin, Ling; Zhou, Xiang

    2016-06-01

    We consider the noise-induced transitions from a linearly stable periodic orbit consisting of T periodic points in randomly perturbed discrete logistic map. Traditional large deviation theory and asymptotic analysis at small noise limit cannot distinguish the quantitative difference in noise-induced stochastic instabilities among the T periodic points. To attack this problem, we generalize the transition path theory to the discrete-time continuous-space stochastic process. In our first criterion to quantify the relative instability among T periodic points, we use the distribution of the last passage location related to the transitions from the whole periodic orbit to a prescribed disjoint set. This distribution is related to individual contributions to the transition rate from each periodic points. The second criterion is based on the competency of the transition paths associated with each periodic point. Both criteria utilize the reactive probability current in the transition path theory. Our numerical results for the logistic map reveal the transition mechanism of escaping from the stable periodic orbit and identify which periodic point is more prone to lose stability so as to make successful transitions under random perturbations.

  8. Locating Depots for Capacitated Vehicle Routing

    DEFF Research Database (Denmark)

    Gørtz, Inge Li; Nagarajan, Viswanath

    2016-01-01

    We study a location-routing problem in the context of capacitated vehicle routing. The input to the k-location capacitated vehicle routing problem (k-LocVRP) consists of a set of demand locations in a metric space and a fleet of k identical vehicles, each of capacity Q. The objective is to locate k...... depots, one for each vehicle, and compute routes for the vehicles so that all demands are satisfied and the total cost is minimized. Our main result is a constant-factor approximation algorithm for k-LocVRP. In obtaining this result, we introduce a common generalization of the k-median and minimum...... spanning tree problems (called k median forest), which might be of independent interest. We give a local-search based (3+ε)-approximation algorithm for k median forest, which leads to a (12+ε)-approximation algorithm for k-LocVRP, for any constant ε>0....

  9. Locating Depots for Capacitated Vehicle Routing

    DEFF Research Database (Denmark)

    Gørtz, Inge Li; Nagarajan, Viswanath

    2016-01-01

    depots, one for each vehicle, and compute routes for the vehicles so that all demands are satisfied and the total cost is minimized. Our main result is a constant-factor approximation algorithm for k-LocVRP. In obtaining this result, we introduce a common generalization of the k-median and minimum...... spanning tree problems (called k median forest), which might be of independent interest. We give a local-search based (3+ε)-approximation algorithm for k median forest, which leads to a (12+ε)-approximation algorithm for k-LocVRP, for any constant ε>0.......We study a location-routing problem in the context of capacitated vehicle routing. The input to the k-location capacitated vehicle routing problem (k-LocVRP) consists of a set of demand locations in a metric space and a fleet of k identical vehicles, each of capacity Q. The objective is to locate k...

  10. Evolutionary paths of streptococcal and staphylococcal superantigens

    Directory of Open Access Journals (Sweden)

    Okumura Kayo

    2012-08-01

    Full Text Available Abstract Background Streptococcus pyogenes (GAS harbors several superantigens (SAgs in the prophage region of its genome, although speG and smez are not located in this region. The diversity of SAgs is thought to arise during horizontal transfer, but their evolutionary pathways have not yet been determined. We recently completed sequencing the entire genome of S. dysgalactiae subsp. equisimilis (SDSE, the closest relative of GAS. Although speG is the only SAg gene of SDSE, speG was present in only 50% of clinical SDSE strains and smez in none. In this study, we analyzed the evolutionary paths of streptococcal and staphylococcal SAgs. Results We compared the sequences of the 12–60 kb speG regions of nine SDSE strains, five speG+ and four speG–. We found that the synteny of this region was highly conserved, whether or not the speG gene was present. Synteny analyses based on genome-wide comparisons of GAS and SDSE indicated that speG is the direct descendant of a common ancestor of streptococcal SAgs, whereas smez was deleted from SDSE after SDSE and GAS split from a common ancestor. Cumulative nucleotide skew analysis of SDSE genomes suggested that speG was located outside segments of steeper slopes than the stable region in the genome, whereas the region flanking smez was unstable, as expected from the results of GAS. We also detected a previously undescribed staphylococcal SAg gene, selW, and a staphylococcal SAg -like gene, ssl, in the core genomes of all Staphylococcus aureus strains sequenced. Amino acid substitution analyses, based on dN/dS window analysis of the products encoded by speG, selW and ssl suggested that all three genes have been subjected to strong positive selection. Evolutionary analysis based on the Bayesian Markov chain Monte Carlo method showed that each clade included at least one direct descendant. Conclusions Our findings reveal a plausible model for the comprehensive evolutionary pathway of streptococcal and

  11. Integrated path towards geological storage

    International Nuclear Information System (INIS)

    Bouchard, R.; Delaytermoz, A.

    2004-01-01

    Among solutions to contribute to CO 2 emissions mitigation, sequestration is a promising path that presents the main advantage of being able to cope with the large volume at stake when considering the growing energy demand. Of particular importance, geological storage has widely been seen as an effective solution for large CO 2 sources like power plants or refineries. Many R and D projects have been initiated, whereby research institutes, government agencies and end-users achieve an effective collaboration. So far, progress has been made towards reinjection of CO 2 , in understanding and then predicting the phenomenon and fluid dynamics inside the geological target, while monitoring the expansion of the CO 2 bubble in the case of demonstration projects. A question arises however when talking about sequestration, namely the time scale to be taken into account. Time is indeed of the essence, and points out the need to understand leakage as well as trapping mechanisms. It is therefore of prime importance to be able to predict the fate of the injected fluids, in an accurate manner and over a relevant period of time. On the grounds of geology, four items are involved in geological storage reliability: the matrix itself, which is the recipient of the injected fluids; the seal, that is the mechanistic trap preventing the injected fluids to flow upward and escape; the lower part of the concerned structure, usually an aquifer, that can be a migration way for dissolved fluids; and the man- made injecting hole, the well, whose characteristics should be as good as the geological formation itself. These issues call for specific competencies such as reservoir engineering, geology and hydrodynamics, mineral chemistry, geomechanics, and well engineering. These competencies, even if put to use to a large extent in the oil industry, have never been connected with the reliability of geological storage as ultimate goal. This paper aims at providing an introduction to these

  12. Integrated robust controller for vehicle path following

    Energy Technology Data Exchange (ETDEWEB)

    Mashadi, Behrooz; Ahmadizadeh, Pouyan, E-mail: p-ahmadizadeh@iust.ac.ir; Majidi, Majid, E-mail: m-majidi@iust.ac.ir [Iran University of Science and Technology, School of Automotive Engineering (Iran, Islamic Republic of); Mahmoodi-Kaleybar, Mehdi, E-mail: m-mahmoodi-k@iust.ac.ir [Iran University of Science and Technology, School of Mechanical Engineering (Iran, Islamic Republic of)

    2015-02-15

    The design of an integrated 4WS+DYC control system to guide a vehicle on a desired path is presented. The lateral dynamics of the path follower vehicle is formulated by considering important parameters. To reduce the effect of uncertainties in vehicle parameters, a robust controller is designed based on a μ-synthesis approach. Numerical simulations are performed using a nonlinear vehicle model in MATLAB environment in order to investigate the effectiveness of the designed controller. Results of simulations show that the controller has a profound ability to making the vehicle track the desired path in the presence of uncertainties.

  13. Path integral for relativistic particle theory

    International Nuclear Information System (INIS)

    Fradkin, E.S.; Gitman, D.M.; Shvartsman, Sh.M.

    1990-06-01

    An action for a relativistic spinning particle interacting with external electromagnetic field is considered in reparametrization and local supergauge invariant form. It is shown that various path integral representations derived for the causal Green function correspond to the different forms of the relativistic particle action. The analogy of the path integral derived with the Lagrangian path integral of the field theory is discussed. It is shown that to obtain the causal propagator, the integration over the null mode of the Lagrangian multiplier corresponding to the reparametrization invariance, has to be performed in the (0,+infinity) limits. (author). 23 refs

  14. Integrated robust controller for vehicle path following

    International Nuclear Information System (INIS)

    Mashadi, Behrooz; Ahmadizadeh, Pouyan; Majidi, Majid; Mahmoodi-Kaleybar, Mehdi

    2015-01-01

    The design of an integrated 4WS+DYC control system to guide a vehicle on a desired path is presented. The lateral dynamics of the path follower vehicle is formulated by considering important parameters. To reduce the effect of uncertainties in vehicle parameters, a robust controller is designed based on a μ-synthesis approach. Numerical simulations are performed using a nonlinear vehicle model in MATLAB environment in order to investigate the effectiveness of the designed controller. Results of simulations show that the controller has a profound ability to making the vehicle track the desired path in the presence of uncertainties

  15. Path-Goal Theory of Leadership

    Science.gov (United States)

    1975-04-01

    Leadership and Turnover Among Managers ," Organization Behavior and Human Performance, 10(1973), pp. 184-200; R. J. House, "A Path-Goal Theory of...of Leadership ." 6R. J. House and G. Dessler, "Path-Goal Theory of Leadership " R. M. Stqg- dill. Managers , Employees, Organization (Ohio State...of Control." 23 R. J. House, "Notes on the Path-Goal Theory of Leadership " (University of Toronto, Faculty of Management Studies, May 1974). 24 R

  16. Path integral representations on the complex sphere

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-08-15

    In this paper we discuss the path integral representations for the coordinate systems on the complex sphere S{sub 3C}. The Schroedinger equation, respectively the path integral, separates in exactly 21 orthogonal coordinate systems. We enumerate these coordinate systems and we are able to present the path integral representations explicitly in the majority of the cases. In each solution the expansion into the wave-functions is stated. Also, the kernel and the corresponding Green function can be stated in closed form in terms of the invariant distance on the sphere, respectively on the hyperboloid. (orig.)

  17. Path probabilities of continuous time random walks

    International Nuclear Information System (INIS)

    Eule, Stephan; Friedrich, Rudolf

    2014-01-01

    Employing the path integral formulation of a broad class of anomalous diffusion processes, we derive the exact relations for the path probability densities of these processes. In particular, we obtain a closed analytical solution for the path probability distribution of a Continuous Time Random Walk (CTRW) process. This solution is given in terms of its waiting time distribution and short time propagator of the corresponding random walk as a solution of a Dyson equation. Applying our analytical solution we derive generalized Feynman–Kac formulae. (paper)

  18. Path integral representations on the complex sphere

    International Nuclear Information System (INIS)

    Grosche, C.

    2007-08-01

    In this paper we discuss the path integral representations for the coordinate systems on the complex sphere S 3C . The Schroedinger equation, respectively the path integral, separates in exactly 21 orthogonal coordinate systems. We enumerate these coordinate systems and we are able to present the path integral representations explicitly in the majority of the cases. In each solution the expansion into the wave-functions is stated. Also, the kernel and the corresponding Green function can be stated in closed form in terms of the invariant distance on the sphere, respectively on the hyperboloid. (orig.)

  19. Positroids Induced by Rational Dyck Paths

    OpenAIRE

    Gotti, Felix

    2017-01-01

    A rational Dyck path of type $(m,d)$ is an increasing unit-step lattice path from $(0,0)$ to $(m,d) \\in \\mathbb{Z}^2$ that never goes above the diagonal line $y = (d/m)x$. On the other hand, a positroid of rank $d$ on the ground set $[d+m]$ is a special type of matroid coming from the totally nonnegative Grassmannian. In this paper we describe how to naturally assign a rank $d$ positroid on the ground set $[d+m]$, which we name rational Dyck positroid, to each rational Dyck path of type $(m,d...

  20. New framework for the Feynman path integral

    International Nuclear Information System (INIS)

    Shaharir, M.Z.

    1986-01-01

    The well-known Fourier integral solution of the free diffusion equation in an arbitrary Euclidean space is reduced to Feynmannian integrals using the method partly contained in the formulation of the Fresnelian integral. By replacing the standard Hilbert space underlying the present mathematical formulation of the Feynman path integral by a new Hilbert space, the space of classical paths on the tangent bundle to the Euclidean space (and more general to an arbitrary Riemannian manifold) equipped with a natural inner product, we show that our Feynmannian integral is in better agreement with the qualitative features of the original Feynman path integral than the previous formulations of the integral

  1. Realizing spaces as path-component spaces

    OpenAIRE

    Banakh, Taras; Brazas, Jeremy

    2018-01-01

    The path component space of a topological space $X$ is the quotient space $\\pi_0(X)$ whose points are the path components of $X$. We show that every Tychonoff space $X$ is the path-component space of a Tychonoff space $Y$ of weight $w(Y)=w(X)$ such that the natural quotient map $Y\\to \\pi_0(Y)=X$ is a perfect map. Hence, many topological properties of $X$ transfer to $Y$. We apply this result to construct a compact space $X\\subset \\mathbb{R}^3$ for which the fundamental group $\\pi_1(X,x_0)$ is...

  2. Seismic and Infrasound Location

    Energy Technology Data Exchange (ETDEWEB)

    Arrowsmith, Stephen J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Begnaud, Michael L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-03-19

    This presentation includes slides on Signal Propagation Through the Earth/Atmosphere Varies at Different Scales; 3D Seismic Models: RSTT; Ray Coverage (Pn); Source-Specific Station Corrections (SSSCs); RSTT Conclusions; SALSA3D (SAndia LoS Alamos) Global 3D Earth Model for Travel Time; Comparison of IDC SSSCs to RSTT Predictions; SALSA3D; Validation and Model Comparison; DSS Lines in the Siberian Platform; DSS Line CRA-4 Comparison; Travel Time Δak135; Travel Time Prediction Uncertainty; SALSA3D Conclusions; Infrasound Data Processing: An example event; Infrasound Data Processing: An example event; Infrasound Location; How does BISL work?; BISL: Application to the 2013 DPRK Test; and BISL: Ongoing Research.

  3. A Dual-Based Procedure for Dynamic Facility Location

    OpenAIRE

    Tony J. Van Roy; Donald Erlenkotter

    1982-01-01

    In dynamic facility location problems, one desires to select the time-staged establishment of facilities at different locations so as to minimize the total discounted costs for meeting demands specified over time at various customer locations. We formulate a particular dynamic facility location problem as a combinatorial optimization problem. The formulation permits both the opening of new facilities and the closing of existing ones. A branch-and-bound procedure incorporating a dual ascent me...

  4. 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.

  5. Demographics and remote locations

    Energy Technology Data Exchange (ETDEWEB)

    Coppus, G. [Dynawise Inc., Calgary, AB (Canada)

    2005-07-01

    Within the next decade, the number of people leaving the workforce will exceed the number of new entrants. The demand for workers is expected to increase in Alberta due to oil sands industry growth. Sixty-four per cent of all responding federal, provincial, and municipal government organizations have reported shortages in their work environments, and almost 8 in 10 organizations predict they will continue to be understaffed in the next 3 to 5 years. Tightness in the general labour market will have an impact on employers in remote locations, and planning is essential to avoid the creation of a mercenary culture and a reliance on compensation. Challenges found in remote locations include high turnover rates among recent hires; critical gaps in service length; aggressive retirement; and the fact that the local population is often seen as unqualified for many industrial jobs. This Power Point presentation suggested that although decisions to join or quit a company are often based on considerations such as the organizational environment and amount of compensation, the relationship between employees and management is the most important attribute in many career decisions. Rigorous quantitative analysis of current demographics combined with forecasting analysis may help to forestall recruitment difficulties for many companies. Productivity analyses, and the effects of work overload on absenteeism, attrition and quality of workmanship must also be examined. Many companies are now focusing on retention and development strategies on mid-career staff to address depletion, as well as redesigning procedures to operate with less skilled staff. It was concluded that extra efforts are now being made to attract non-traditional employees, and non-traditional employment models are being considered by some companies. refs., tabs., figs.

  6. The shortest path algorithm performance comparison in graph and relational database on a transportation network

    Directory of Open Access Journals (Sweden)

    Mario Miler

    2014-02-01

    Full Text Available In the field of geoinformation and transportation science, the shortest path is calculated on graph data mostly found in road and transportation networks. This data is often stored in various database systems. Many applications dealing with transportation network require calculation of the shortest path. The objective of this research is to compare the performance of Dijkstra shortest path calculation in PostgreSQL (with pgRouting and Neo4j graph database for the purpose of determining if there is any difference regarding the speed of the calculation. Benchmarking was done on commodity hardware using OpenStreetMap road network. The first assumption is that Neo4j graph database would be well suited for the shortest path calculation on transportation networks but this does not come without some cost. Memory proved to be an issue in Neo4j setup when dealing with larger transportation networks.

  7. 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.

  8. Optimal Path Choice in Railway Passenger Travel Network Based on Residual Train Capacity

    Directory of Open Access Journals (Sweden)

    Fei Dou

    2014-01-01

    Full Text Available Passenger’s optimal path choice is one of the prominent research topics in the field of railway passenger transport organization. More and more different train types are available, increasing path choices from departure to destination for travelers are unstoppable. However, travelers cannot avoid being confused when they hope to choose a perfect travel plan based on various travel time and cost constraints before departure. In this study, railway passenger travel network is constructed based on train timetable. Both the generalized cost function we developed and the residual train capacity are considered to be the foundation of path searching procedure. The railway passenger travel network topology is analyzed based on residual train capacity. Considering the total travel time, the total travel cost, and the total number of passengers, we propose an optimal path searching algorithm based on residual train capacity in railway passenger travel network. Finally, the rationale of the railway passenger travel network and the optimal path generation algorithm are verified positively by case study.

  9. NSRD-10: Leak Path Factor Guidance Using MELCOR

    Energy Technology Data Exchange (ETDEWEB)

    Louie, David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Humphries, Larry L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-03-01

    Estimates of the source term from a U.S. Department of Energy (DOE) nuclear facility requires that the analysts know how to apply the simulation tools used, such as the MELCOR code, particularly for a complicated facility that may include an air ventilation system and other active systems that can influence the environmental pathway of the materials released. DOE has designated MELCOR 1.8.5, an unsupported version, as a DOE ToolBox code in its Central Registry, which includes a leak-path-factor guidance report written in 2004 that did not include experimental validation data. To continue to use this MELCOR version requires additional verification and validations, which may not be feasible from a project cost standpoint. Instead, the recent MELCOR should be used. Without any developer support and lack of experimental data validation, it is difficult to convince regulators that the calculated source term from the DOE facility is accurate and defensible. This research replaces the obsolete version in the 2004 DOE leak path factor guidance report by using MELCOR 2.1 (the latest version of MELCOR with continuing modeling development and user support) and by including applicable experimental data from the reactor safety arena and from applicable experimental data used in the DOE-HDBK-3010. This research provides best practice values used in MELCOR 2.1 specifically for the leak path determination. With these enhancements, the revised leak-path-guidance report should provide confidence to the DOE safety analyst who would be using MELCOR as a source-term determination tool for mitigated accident evaluations.

  10. 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.

  11. Accelerating cleanup: Paths to closure

    International Nuclear Information System (INIS)

    1998-06-01

    This report describes the status of Environmental Management's (EM's) cleanup program and a direction forward to complete achievement of the 2006 vision. Achieving the 2006 vision results in significant benefits related to accomplishing EM program objectives. As DOE sites accelerate cleanup activities, risks to public health, the environment, and worker safety and health are all reduced. Finding more efficient ways to conduct work can result in making compliance with applicable environmental requirements easier to achieve. Finally, as cleanup activities at sites are completed, the EM program can focus attention and resources on the small number of sites with more complex cleanup challenges. Chapter 1 describes the process by which this report has been developed and what it hopes to accomplish, its relationship to the EM decision-making process, and a general background of the EM mission and program. Chapter 2 describes how the site-by-site projections were constructed, and summarizes, for each of DOE's 11 Operations/Field Offices, the projected costs and schedules for completing the cleanup mission. Chapter 3 presents summaries of the detailed cleanup projections from three of the 11 Operations/Field Offices: Rocky Flats (Colorado), Richland (Washington), and Savannah River (South Carolina). The remaining eight Operations/Field Office summaries are in Appendix E. Chapter 4 reviews the cost drivers, budgetary constraints, and performance enhancements underlying the detailed analysis of the 353 projects that comprise EM's accelerated cleanup and closure effort. Chapter 5 describes a management system to support the EM program. Chapter 6 provides responses to the general comments received on the February draft of this document

  12. Quantitative analytical hierarchy process to marketing store location selection

    Directory of Open Access Journals (Sweden)

    Harwati

    2018-01-01

    Full Text Available The selection of Store to market the product is belong to Multi Criteria Decision Making problem. The criteria used have conflict of interest with each other to produce an optimal location. This research uses four important criteria to select new location of marketing store appropriate with the references: distance to location, competition level with competitor, number of potential customer, and location rent cost. Quantitative data is used to determine the optimum location with AHP method. Quantitative data are preferred to avoid inconsistency when using expert opinion. The AHP result optimum location among three alternatives places.

  13. Two paths from lab to market: Product and standard

    Science.gov (United States)

    Knapp, Robert H.

    2018-01-01

    To shed light on the movement of sustainable technologies from basic science to widespread use, this chapter describes key aspects of the quite different paths followed by two important examples—photovoltaics (a product) and passive-house buildings (a standard). Discussion of photovoltaics includes the experience curve concept, the increasing significance of balance-of-system costs, and the importance of market heterogeneity (niches and sub-national markets) to the long-term trajectory of major cost reductions. Discussion of passive-houses highlights the array of technical developments needed for present-day energy efficient houses, and the relevance of "stretch" standards to the development of a market for very high-performance houses.

  14. 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.

  15. Northern Pintail - Flight Path Telemetry [ds117

    Data.gov (United States)

    California Natural Resource Agency — North-south flight paths of radio-tagged female northern pintails were monitored in a section of Highway 152 near Los Banos, California during 4 and 11 November and...

  16. Ductility behavior of irradiated path B alloys

    International Nuclear Information System (INIS)

    Yang, W.J.S.; Hamilton, M.L.

    1983-01-01

    The objective of this study was to assess the practicality of using five Path B alloys in their current form as structural materials in the Fusion First-Wall/Blanket by evaluating both their postirradiation ductility and the corresponding microstructures

  17. AEDT sensor path methods using BADA4

    Science.gov (United States)

    2017-06-01

    This report documents the development and use of sensor path data processing in the Federal Aviation Administration's (FAAs) Aviation Environmental Design Tool (AEDT). The methods are primarily intended to assist analysts with using AEDT to determ...

  18. Modeling and Solving the Train Pathing Problem

    Directory of Open Access Journals (Sweden)

    Chuen-Yih Chen

    2009-04-01

    Full Text Available In a railroad system, train pathing is concerned with the assignment of trains to links and tracks, and train timetabling allocates time slots to trains. In this paper, we present an optimization heuristic to solve the train pathing and timetabling problem. This heuristic allows the dwell time of trains in a station or link to be dependent on the assigned tracks. It also allows the minimum clearance time between the trains to depend on their relative status. The heuristic generates a number of alternative paths for each train service in the initialization phase. Then it uses a neighborhood search approach to find good feasible combinations of these paths. A linear program is developed to evaluate the quality of each combination that is encountered. Numerical examples are provided.

  19. Search Path Evaluation Incorporating Object Placement Structure

    National Research Council Canada - National Science Library

    Baylog, John G; Wettergren, Thomas A

    2007-01-01

    This report describes a computationally robust approach to search path performance evaluation where the objects of search interest exhibit structure in the way in which they occur within the search space...

  20. 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.

  1. Diversion Path Analysis Handbook. Volume 1. Methodology

    International Nuclear Information System (INIS)

    Goodwin, K.E.; Schleter, J.C.; Maltese, M.D.K.

    1978-11-01

    Diversion Path Analysis (DPA) is a safeguards evaluation tool which is used to determine the vulnerability of the Material Control and Material Accounting (MC and MA) Subsystems to the threat of theft of Special Nuclear Material (SNM) by a knowledgeable Insider. The DPA team should consist of two individuals who have technical backgrounds. The implementation of DPA is divided into five basic steps: Information and Data Gathering, Process Characterization, Analysis of Diversion Paths, Results and Findings, and Documentation

  2. 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.

  3. A career path in clinical pathways.

    Science.gov (United States)

    Bower, K A

    1998-03-01

    Much like the development of a clinical path, the creation of a career path requires knowledge of patterns of behavior, needs for standardized education and skill development, along with variance analysis and individualized care. This nationally known nursing entrepreneur tells the story of her involvement in the development of case management and clinical pathways and how she turned that into a successful business that has changed how patient care is managed nationally and internationally.

  4. 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)

  5. Lattice Paths and the Constant Term

    International Nuclear Information System (INIS)

    Brak, R; Essam, J; Osborn, J; Owczarek, A L; Rechnitzer, A

    2006-01-01

    We firstly review the constant term method (CTM), illustrating its combinatorial connections and show how it can be used to solve a certain class of lattice path problems. We show the connection between the CTM, the transfer matrix method (eigenvectors and eigenvalues), partial difference equations, the Bethe Ansatz and orthogonal polynomials. Secondly, we solve a lattice path problem first posed in 1971. The model stated in 1971 was only solved for a special case - we solve the full model

  6. An Efficient Shortest Path Routing Algorithm for Directed Indoor Environments

    Directory of Open Access Journals (Sweden)

    Sultan Alamri

    2018-03-01

    Full Text Available Routing systems for outdoor space have become the focus of many research works. Such routing systems are based on spatial road networks where moving objects (such as cars are affected by the directed roads and the movement of traffic, which may include traffic jams. Indoor routing, on the other hand, must take into account the features of indoor space such as walls and rooms. In this paper, we take indoor routing in a new direction whereby we consider the features that a building has in common with outdoor spaces. Inside some buildings, there may be directed floors where moving objects must move in a certain direction through directed corridors in order to reach a certain location. For example, on train platforms or in museums, movement in the corridors may be directed. In these directed floor spaces, a routing system enabling a visitor to take the shortest path to a certain location is essential. Therefore, this work proposes a new approach for buildings with directed indoor spaces, where each room can be affected by the density of the moving objects. The proposed system obtains the shortest path between objects or rooms taking into consideration the directed indoor space and the capacity of the objects to move within each room/cell.

  7. Path Diversity Improved Opportunistic Routing for Underwater Sensor Networks.

    Science.gov (United States)

    Bai, Weigang; Wang, Haiyan; He, Ke; Zhao, Ruiqin

    2018-04-23

    The packets carried along a pre-defined route in underwater sensor networks are very vulnerble. Node mobility or intermittent channel availability easily leads to unreachable routing. Opportunistic routing has been proven to be a promising paradigm to design routing protocols for underwater sensor networks. It takes advantage of the broadcast nature of the wireless medium to combat packet losses and selects potential paths on the fly. Finding an appropriate forwarding candidate set is a key issue in opportunistic routing. Many existing solutions ignore the impact of candidates location distribution on packet forwarding. In this paper, a path diversity improved candidate selection strategy is applied in opportunistic routing to improve packet forwarding efficiency. It not only maximizes the packet forwarding advancements but also takes the candidate’s location distribution into account. Based on this strategy, we propose two effective routing protocols: position improved candidates selection (PICS) and position random candidates selection (PRCS). PICS employs two-hop neighbor information to make routing decisions. PRCS only uses one-hop neighbor information. Simulation results show that both PICS and PRCS can significantly improve network performance when compared with the previous solutions, in terms of packet delivery ratio, average energy consumption and end-to-end delay.

  8. Path Diversity Improved Opportunistic Routing for Underwater Sensor Networks

    Directory of Open Access Journals (Sweden)

    Weigang Bai

    2018-04-01

    Full Text Available The packets carried along a pre-defined route in underwater sensor networks are very vulnerble. Node mobility or intermittent channel availability easily leads to unreachable routing. Opportunistic routing has been proven to be a promising paradigm to design routing protocols for underwater sensor networks. It takes advantage of the broadcast nature of the wireless medium to combat packet losses and selects potential paths on the fly. Finding an appropriate forwarding candidate set is a key issue in opportunistic routing. Many existing solutions ignore the impact of candidates location distribution on packet forwarding. In this paper, a path diversity improved candidate selection strategy is applied in opportunistic routing to improve packet forwarding efficiency. It not only maximizes the packet forwarding advancements but also takes the candidate’s location distribution into account. Based on this strategy, we propose two effective routing protocols: position improved candidates selection (PICS and position random candidates selection (PRCS. PICS employs two-hop neighbor information to make routing decisions. PRCS only uses one-hop neighbor information. Simulation results show that both PICS and PRCS can significantly improve network performance when compared with the previous solutions, in terms of packet delivery ratio, average energy consumption and end-to-end delay.

  9. A Neural Path Integration Mechanism for Adaptive Vector Navigation in Autonomous Agents

    DEFF Research Database (Denmark)

    Goldschmidt, Dennis; Dasgupta, Sakyasingha; Wörgötter, Florentin

    2015-01-01

    Animals show remarkable capabilities in navigating their habitat in a fully autonomous and energy-efficient way. In many species, these capabilities rely on a process called path integration, which enables them to estimate their current location and to find their way back home after long-distance...... of autonomous agent navigation, but it also reproduces various aspects of animal navigation. Finally, we discuss how the proposed path integration mechanism may be used as a scaffold for spatial learning in terms of vector navigation.......Animals show remarkable capabilities in navigating their habitat in a fully autonomous and energy-efficient way. In many species, these capabilities rely on a process called path integration, which enables them to estimate their current location and to find their way back home after long...

  10. On location at CERN

    CERN Multimedia

    Joannah Caborn Wengler

    2012-01-01

    CERN continues to be a very popular candidate for film locations at the moment. Not only has it inspired a German author and a film-maker interested in the more exotic interpretations of the science being worked on at the Organization, but even the recent puppet animation film by the legendary Muppets featured some CERN scenes.   Dr Bunsen Honeydew (far left) and his friends at ATLAS. Beaker, Bunsen's assistant, has just been sucked up the vacuum tube top left... Image courtesy Walt Disney Studios. In “The Muppet Movie”, released in November 2011 in North America and world-wide in January and February this year, Kermit is reuniting his friends who have ended up in some far-flung places since they last worked together 10 years ago. CERN caught the imagination of the film-makers as the perfect place for the Muppet scientists, Dr. Honeydew Bunsen and his hapless assistant Beaker. After a brief scene filmed in front of a backdrop of the ATLAS detector, the rest of the ...

  11. Computing Diffeomorphic Paths for Large Motion Interpolation.

    Science.gov (United States)

    Seo, Dohyung; Jeffrey, Ho; Vemuri, Baba C

    2013-06-01

    In this paper, we introduce a novel framework for computing a path of diffeomorphisms between a pair of input diffeomorphisms. Direct computation of a geodesic path on the space of diffeomorphisms Diff (Ω) is difficult, and it can be attributed mainly to the infinite dimensionality of Diff (Ω). Our proposed framework, to some degree, bypasses this difficulty using the quotient map of Diff (Ω) to the quotient space Diff ( M )/ Diff ( M ) μ obtained by quotienting out the subgroup of volume-preserving diffeomorphisms Diff ( M ) μ . This quotient space was recently identified as the unit sphere in a Hilbert space in mathematics literature, a space with well-known geometric properties. Our framework leverages this recent result by computing the diffeomorphic path in two stages. First, we project the given diffeomorphism pair onto this sphere and then compute the geodesic path between these projected points. Second, we lift the geodesic on the sphere back to the space of diffeomerphisms, by solving a quadratic programming problem with bilinear constraints using the augmented Lagrangian technique with penalty terms. In this way, we can estimate the path of diffeomorphisms, first, staying in the space of diffeomorphisms, and second, preserving shapes/volumes in the deformed images along the path as much as possible. We have applied our framework to interpolate intermediate frames of frame-sub-sampled video sequences. In the reported experiments, our approach compares favorably with the popular Large Deformation Diffeomorphic Metric Mapping framework (LDDMM).

  12. Quantum cosmology based on discrete Feynman paths

    International Nuclear Information System (INIS)

    Chew, Geoffrey F.

    2002-01-01

    Although the rules for interpreting local quantum theory imply discretization of process, Lorentz covariance is usually regarded as precluding time quantization. Nevertheless a time-discretized quantum representation of redshifting spatially-homogeneous universe may be based on discrete-step Feynman paths carrying causal Lorentz-invariant action--paths that not only propagate the wave function but provide a phenomenologically-promising elementary-particle Hilbert-space basis. In a model under development, local path steps are at Planck scale while, at a much larger ''wave-function scale'', global steps separate successive wave-functions. Wave-function spacetime is but a tiny fraction of path spacetime. Electromagnetic and gravitational actions are ''at a distance'' in Wheeler-Feynman sense while strong (color) and weak (isospin) actions, as well as action of particle motion, are ''local'' in a sense paralleling the action of local field theory. ''Nonmaterial'' path segments and ''trivial events'' collaborate to define energy and gravity. Photons coupled to conserved electric charge enjoy privileged model status among elementary fermions and vector bosons. Although real path parameters provide no immediate meaning for ''measurement'', the phase of the complex wave function allows significance for ''information'' accumulated through ''gentle'' electromagnetic events involving charged matter and ''soft'' photons. Through its soft-photon content the wave function is an ''information reservoir''

  13. 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

  14. Transaction costs and technological development: The case of the Danish fruit and vegetable industry

    DEFF Research Database (Denmark)

    Foss, Kirsten

    1996-01-01

    It is argued that technological change can be understood in terms of attempts to reduce transaction costs as well as production costs. Two types of paths of technological development are identified: a production cost minimizing path, and a transac cost minimizing path. The creation of new...... technological opportunites underlying the path of production-cost.minimizing depends on the emergence of problems of optimizing the performance of products and processing technology. The exploitation of su opportunities may easily be interpreted within a production perspective since the economic consequences...... would be reduced production costs. The creation of new technological opportunities within the transaction-costs-minimizing path depends on th continual emergence of problems related to the control of variablility in product quality or performance. The economic consequence from exploiting...

  15. The processing of spatial information in short-term memory: insights from eye tracking the path length effect.

    Science.gov (United States)

    Guérard, Katherine; Tremblay, Sébastien; Saint-Aubin, Jean

    2009-10-01

    Serial memory for spatial locations increases as the distance between successive stimuli locations decreases. This effect, known as the path length effect [Parmentier, F. B. R., Elford, G., & Maybery, M. T. (2005). Transitional information in spatial serial memory: Path characteristics affect recall performance. Journal of Experimental Psychology: Learning, Memory & Cognition, 31, 412-427], was investigated in a systematic manner using eye tracking and interference procedures to explore the mechanisms responsible for the processing of spatial information. In Experiment 1, eye movements were monitored during a spatial serial recall task--in which the participants have to remember the location of spatially and temporally separated dots on the screen. In the experimental conditions, eye movements were suppressed by requiring participants to incessantly move their eyes between irrelevant locations. Ocular suppression abolished the path length effect whether eye movements were prevented during item presentation or during a 7s retention interval. In Experiment 2, articulatory suppression was combined with a spatial serial recall task. Although articulatory suppression impaired performance, it did not alter the path length effect. Our results suggest that rehearsal plays a key role in serial memory for spatial information, though the effect of path length seems to involve other processes located at encoding, such as the time spent fixating each location and perceptual organization.

  16. Path analyses of yield and some agronomic and quality traits of ...

    African Journals Online (AJOL)

    ONOS

    2010-08-09

    Aug 9, 2010 ... This research was conducted to determine characters effecting grain yield in fifty bread wheat (Triticum aestivum L.) cultivars and advanced lines by using simple correlation coefficient and path analysis under 2 locations (high rainfall and low rainfall; 745 and 506 mm, respectively). A total of 50 genotypes,.

  17. The price path due to order imbalances: evidence from the Amsterdam agricultural futures exchange.

    NARCIS (Netherlands)

    Pennings, J.M.E.; Kuiper, W.E.; Hofstede, ter F.; Meulenberg, M.T.G.

    1998-01-01

    The lack of sufficient market depth particularly in many newly initiated futures markets results in relatively high hedging costs, and this inhibits the growth of futures contract volume. In this article the price path due to order imbalances is analyzed and a two-dimensional market depth measure is

  18. Nuclear power generating costs

    International Nuclear Information System (INIS)

    Srinivasan, M.R.; Kati, S.L.; Raman, R.; Nanjundeswaran, K.; Nadkarny, G.V.; Verma, R.S.; Mahadeva Rao, K.V.

    1983-01-01

    Indian experience pertaining to investment and generation costs of nuclear power stations is reviewed. The causes of investment cost increases are analysed and the increases are apportioned to escalation, design improvements and safety related adders. The paper brings out the fact that PHWR investment costs in India compare favourably with those experienced in developed countries in spite of the fact that the programme and the unit size are relatively much smaller in India. It brings out that in India at current prices a nuclear power station located over 800 km from coal reserves and operating at 75% capacity factor is competitive with thermal power at 60% capacity factor. (author)

  19. Location aware event driven multipath routing in Wireless Sensor Networks: Agent based approach

    Directory of Open Access Journals (Sweden)

    A.V. Sutagundar

    2013-03-01

    Full Text Available Wireless Sensor Networks (WSNs demand reliable and energy efficient paths for critical information delivery to sink node from an event occurrence node. Multipath routing facilitates reliable data delivery in case of critical information. This paper proposes an event triggered multipath routing in WSNs by employing a set of static and mobile agents. Every sensor node is assumed to know the location information of the sink node and itself. The proposed scheme works as follows: (1 Event node computes the arbitrary midpoint between an event node and the sink node by using location information. (2 Event node establishes a shortest path from itself to the sink node through the reference axis by using a mobile agent with the help of location information; the mobile agent collects the connectivity information and other parameters of all the nodes on the way and provides the information to the sink node. (3 Event node finds the arbitrary location of the special (middle intermediate nodes (above/below reference axis by using the midpoint location information given in step 1. (4 Mobile agent clones from the event node and the clones carry the event type and discover the path passing through special intermediate nodes; the path above/below reference axis looks like an arc. While migrating from one sensor node to another along the traversed path, each mobile agent gathers the node information (such as node id, location information, residual energy, available bandwidth, and neighbors connectivity and delivers to the sink node. (5 The sink node constructs a partial topology, connecting event and sink node by using the connectivity information delivered by the mobile agents. Using the partial topology information, sink node finds the multipath and path weight factor by using link efficiency, energy ratio, and hop distance. (6 The sink node selects the number of paths among the available paths based upon the criticalness of an event, and (7 if the event is non

  20. Forces in Motzkin paths in a wedge

    International Nuclear Information System (INIS)

    Janse van Rensburg, E J

    2006-01-01

    Entropic forces in models of Motzkin paths in a wedge geometry are considered as models of forces in polymers in confined geometries. A Motzkin path in the square lattice is a path from the origin to a point in the line Y = X while it never visits sites below this line, and it is constrained to give unit length steps only in the north and east directions and steps of length √2 in the north-east direction. Motzkin path models may be generalized to ensembles of NE-oriented paths above the line Y = rX, where r > 0 is an irrational number. These are paths giving east, north and north-east steps from the origin in the square lattice, and confined to the r-wedge formed by the Y-axis and the line Y = rX. The generating function g r of these paths is not known, but if r > 1, then I determine its radius of convergence to be t r = min (r-1)/r≤y≤r/(r+1) [y y (1-r(1-y)) 1-r(1-y) (r(1-y)-y) r(1-y)-y ] and if r is an element of (0, 1), then t r = 1/3. The entropic force the path exerts on the line Y rX may be computed from this. An asymptotic expression for the force for large values of r is given by F(r) = log(2r)/r 2 - (1+2log(2r))/2r 3 + O (log(2r)/r 4 ). In terms of the vertex angle α of the r-wedge, the moment of the force about the origin has leading terms F(α) log(2/α) - (α/2)(1+2log(2/α)) + O(α 2 log(2/α)) as α → 0 + and F(α) = 0 if α is element of [π/4, π/2]. Moreover, numerical integration of the force shows that the total work done by closing the wedge is 1.085 07... lattice units. An alternative ensemble of NE-oriented paths may be defined by slightly changing the generating function g r . In this model, it is possible to determine closed-form expressions for the limiting free energy and the force. The leading term in an asymptotic expansions for this force agrees with the leading term in the asymptotic expansion of the above model, and the subleading term only differs by a factor of 2

  1. Path spectra derived from inversion of source and site spectra for earthquakes in Southern California

    Science.gov (United States)

    Klimasewski, A.; Sahakian, V. J.; Baltay, A.; Boatwright, J.; Fletcher, J. B.; Baker, L. M.

    2017-12-01

    A large source of epistemic uncertainty in Ground Motion Prediction Equations (GMPEs) is derived from the path term, currently represented as a simple geometric spreading and intrinsic attenuation term. Including additional physical relationships between the path properties and predicted ground motions would produce more accurate and precise, region-specific GMPEs by reclassifying some of the random, aleatory uncertainty as epistemic. This study focuses on regions of Southern California, using data from the Anza network and Southern California Seismic network to create a catalog of events magnitude 2.5 and larger from 1998 to 2016. The catalog encompasses regions of varying geology and therefore varying path and site attenuation. Within this catalog of events, we investigate several collections of event region-to-station pairs, each of which share similar origin locations and stations so that all events have similar paths. Compared with a simple regional GMPE, these paths consistently have high or low residuals. By working with events that have the same path, we can isolate source and site effects, and focus on the remaining residual as path effects. We decompose the recordings into source and site spectra for each unique event and site in our greater Southern California regional database using the inversion method of Andrews (1986). This model represents each natural log record spectra as the sum of its natural log event and site spectra, while constraining each record to a reference site or Brune source spectrum. We estimate a regional, path-specific anelastic attenuation (Q) and site attenuation (t*) from the inversion site spectra and corner frequency from the inversion event spectra. We then compute the residuals between the observed record data, and the inversion model prediction (event*site spectra). This residual is representative of path effects, likely anelastic attenuation along the path that varies from the regional median attenuation. We examine the

  2. Path optimization method for the sign problem

    Directory of Open Access Journals (Sweden)

    Ohnishi Akira

    2018-01-01

    Full Text Available We propose a path optimization method (POM to evade the sign problem in the Monte-Carlo calculations for complex actions. Among many approaches to the sign problem, the Lefschetz-thimble path-integral method and the complex Langevin method are promising and extensively discussed. In these methods, real field variables are complexified and the integration manifold is determined by the flow equations or stochastically sampled. When we have singular points of the action or multiple critical points near the original integral surface, however, we have a risk to encounter the residual and global sign problems or the singular drift term problem. One of the ways to avoid the singular points is to optimize the integration path which is designed not to hit the singular points of the Boltzmann weight. By specifying the one-dimensional integration-path as z = t +if(t(f ϵ R and by optimizing f(t to enhance the average phase factor, we demonstrate that we can avoid the sign problem in a one-variable toy model for which the complex Langevin method is found to fail. In this proceedings, we propose POM and discuss how we can avoid the sign problem in a toy model. We also discuss the possibility to utilize the neural network to optimize the path.

  3. The formal path integral and quantum mechanics

    International Nuclear Information System (INIS)

    Johnson-Freyd, Theo

    2010-01-01

    Given an arbitrary Lagrangian function on R d and a choice of classical path, one can try to define Feynman's path integral supported near the classical path as a formal power series parameterized by 'Feynman diagrams', although these diagrams may diverge. We compute this expansion and show that it is (formally, if there are ultraviolet divergences) invariant under volume-preserving changes of coordinates. We prove that if the ultraviolet divergences cancel at each order, then our formal path integral satisfies a 'Fubini theorem' expressing the standard composition law for the time evolution operator in quantum mechanics. Moreover, we show that when the Lagrangian is inhomogeneous quadratic in velocity such that its homogeneous-quadratic part is given by a matrix with constant determinant, then the divergences cancel at each order. Thus, by 'cutting and pasting' and choosing volume-compatible local coordinates, our construction defines a Feynman-diagrammatic 'formal path integral' for the nonrelativistic quantum mechanics of a charged particle moving in a Riemannian manifold with an external electromagnetic field.

  4. Perfect discretization of reparametrization invariant path integrals

    International Nuclear Information System (INIS)

    Bahr, Benjamin; Dittrich, Bianca; Steinhaus, Sebastian

    2011-01-01

    To obtain a well-defined path integral one often employs discretizations. In the case of gravity and reparametrization-invariant systems, the latter of which we consider here as a toy example, discretizations generically break diffeomorphism and reparametrization symmetry, respectively. This has severe implications, as these symmetries determine the dynamics of the corresponding system. Indeed we will show that a discretized path integral with reparametrization-invariance is necessarily also discretization independent and therefore uniquely determined by the corresponding continuum quantum mechanical propagator. We use this insight to develop an iterative method for constructing such a discretized path integral, akin to a Wilsonian RG flow. This allows us to address the problem of discretization ambiguities and of an anomaly-free path integral measure for such systems. The latter is needed to obtain a path integral, that can act as a projector onto the physical states, satisfying the quantum constraints. We will comment on implications for discrete quantum gravity models, such as spin foams.

  5. Perfect discretization of reparametrization invariant path integrals

    Science.gov (United States)

    Bahr, Benjamin; Dittrich, Bianca; Steinhaus, Sebastian

    2011-05-01

    To obtain a well-defined path integral one often employs discretizations. In the case of gravity and reparametrization-invariant systems, the latter of which we consider here as a toy example, discretizations generically break diffeomorphism and reparametrization symmetry, respectively. This has severe implications, as these symmetries determine the dynamics of the corresponding system. Indeed we will show that a discretized path integral with reparametrization-invariance is necessarily also discretization independent and therefore uniquely determined by the corresponding continuum quantum mechanical propagator. We use this insight to develop an iterative method for constructing such a discretized path integral, akin to a Wilsonian RG flow. This allows us to address the problem of discretization ambiguities and of an anomaly-free path integral measure for such systems. The latter is needed to obtain a path integral, that can act as a projector onto the physical states, satisfying the quantum constraints. We will comment on implications for discrete quantum gravity models, such as spin foams.

  6. A Scheduling Algorithm for Cloud Computing System Based on the Driver of Dynamic Essential Path.

    Science.gov (United States)

    Xie, Zhiqiang; Shao, Xia; Xin, Yu

    2016-01-01

    To solve the problem of task scheduling in the cloud computing system, this paper proposes a scheduling algorithm for cloud computing based on the driver of dynamic essential path (DDEP). This algorithm applies a predecessor-task layer priority strategy to solve the problem of constraint relations among task nodes. The strategy assigns different priority values to every task node based on the scheduling order of task node as affected by the constraint relations among task nodes, and the task node list is generated by the different priority value. To address the scheduling order problem in which task nodes have the same priority value, the dynamic essential long path strategy is proposed. This strategy computes the dynamic essential path of the pre-scheduling task nodes based on the actual computation cost and communication cost of task node in the scheduling process. The task node that has the longest dynamic essential path is scheduled first as the completion time of task graph is indirectly influenced by the finishing time of task nodes in the longest dynamic essential path. Finally, we demonstrate the proposed algorithm via simulation experiments using Matlab tools. The experimental results indicate that the proposed algorithm can effectively reduce the task Makespan in most cases and meet a high quality performance objective.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. A Sun Path Observation System Based on Augment Reality and Mobile Learning

    Directory of Open Access Journals (Sweden)

    Wernhuar Tarng

    2018-01-01

    Full Text Available This study uses the augmented reality technology and sensor functions of GPS, electronic compass, and three-axis accelerometer on mobile devices to develop a Sun path observation system for applications in astronomy education. The orientation and elevation of the Sun can be calculated by the system according to the user’s location and local time to simulate the Sun path. When holding the mobile device toward the sky, the screen will show the virtual Sun at the same position as that of the real Sun. The user can record the Sun path and the data of observation date, time, longitude, and latitude using the celestial hemisphere and the pole shadow on the system. By setting different observation times and locations, it can be seen that the Sun path changes with seasons and latitudes. The system provides contextual awareness of the Sun path concepts, and it can convert the observation data into organized and meaningful astronomical knowledge to enable combination of situated learning with spatial cognition. The system can solve the problem of being not able to record the Sun path due to a bad weather or topographical restrictions, and therefore it is helpful for elementary students when conducting observations. A teaching experiment has been conducted to analyze the learning achievement of students after using the system, and the results show that it is more effective than traditional teaching aids. The questionnaire results also reveal that the system is easy to operate and useful in recording the Sun path data. Therefore, it is an effective tool for astronomy education in elementary schools.

  12. Duality in constrained location problems

    DEFF Research Database (Denmark)

    Juel, Henrik; Love, Robert F.

    1987-01-01

    The dual of a facility location problem with general norms, distance constraints, and linear constraints is formulated.......The dual of a facility location problem with general norms, distance constraints, and linear constraints is formulated....

  13. ICE Online Detainee Locator System

    Data.gov (United States)

    Department of Homeland Security — The Online Detainee Locator datasets provide the location of a detainee who is currently in ICE custody, or who was release from ICE custody for any reason with the...

  14. Path Forward to Space Solar Power using the O'Neill - Glaser Model Modified for Climate Change Demand and Considering the Increasing Risk of Human Self-Extinction if Confined to Earth

    Science.gov (United States)

    Curreri, Peter A.; Nall, Mark

    2013-01-01

    The cost of energy is humanity's economic exchange rate with the universe. Space solar power is the first great step that our technological species has to utilize the energy of its star. The classic Peter Glaser Solar Power Satellite, SPS, and later designs collect a large area of solar energy in space and beam it back to Earth for use in the electric grid, but even with optimistic launch costs and technology innovation a clear economic path is not evident using Earth launch of SPS. O Neill in 1969 solved the transportation costs problem by a model that uses lunar and asteroid materials to build SPS and locates the labor force permanently in space (O Neill free space habitats). This solution closes the economics and predicts large profits after 17-35 years. However the costs of time have up to now prevented this solution. We discuss a strategy to move forward in SPS with the motivations to stop global warming and prevent human selfextinction. There are near term steps that can be taken that place us on this path forward. First, we must reevaluate the technologies for the classic model and update the parameters to current technology. As technological capability continues to increase exponentially, we need to understand when the monetary potential energy hills are small as the technology gets larger. But the chance for self-extinction, if humanity remains in a single vulnerable habitat, also increased exponentially with time. The path forward is to identify investment points while assessing the risks of non-action.

  15. On the Path to SunShot - Emerging Opportunities and Challenges in U.S. Solar Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Donald [National Renewable Energy Lab. (NREL), Golden, CO (United States); Horowitz, Kelsey [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kurup, Parthiv [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-05-01

    Innovation-driven cost and performance improvements, along with strong projected solar demand in the United States and across the Americas, could increase the attractiveness of U.S.-based solar manufacturing (see Chung et al. 2016). Although improvements to standard PV modules have produced deep cost reductions over the past 5 years, the returns on such incremental improvements appear to be diminishing, and more dramatic innovations in module design and manufacturing are required to continue along the path of rapid progress. At the same time, major opportunities exist for innovation to unlock the potential of CSP technologies. This need for innovation could benefit U.S. PV and CSP manufacturers. The United States has been rated one of the world’s most competitive and innovative countries as well as one of the best locations for PV manufacturing. It is a global leader in PV and CSP R&D and patent production, and U.S. PV manufacturers are already pursuing highly differentiated innovations.

  16. Paths to Licensure: Things Physicists Should Know

    Science.gov (United States)

    Stewart, Gay; Stewart, John

    2016-03-01

    The path to licensure can be quite complicated, and can thwart a physics department's efforts to produce more and better prepared high school physics teachers. Each state has different pathways to licensure. Acronyms like CAEP and SPA are not within the normal physicist's vocabulary. Some understanding of this topic can allow physics faculty advisers to help our students so that fewer are derailed on their path to the classroom, or take a path that will leave them less well prepared if they do find themselves there. Examples of different approaches that work within state licensure systems from two different states will be presented. Physics teacher preparation efforts in both Arkansas and West Virginia have been supported in part by the Physics Teacher Education Coalition (PhysTEC).

  17. A taxonomy of integral reaction path analysis

    Energy Technology Data Exchange (ETDEWEB)

    Grcar, Joseph F.; Day, Marcus S.; Bell, John B.

    2004-12-23

    W. C. Gardiner observed that achieving understanding through combustion modeling is limited by the ability to recognize the implications of what has been computed and to draw conclusions about the elementary steps underlying the reaction mechanism. This difficulty can be overcome in part by making better use of reaction path analysis in the context of multidimensional flame simulations. Following a survey of current practice, an integral reaction flux is formulated in terms of conserved scalars that can be calculated in a fully automated way. Conditional analyses are then introduced, and a taxonomy for bidirectional path analysis is explored. Many examples illustrate the resulting path analysis and uncover some new results about nonpremixed methane-air laminar jets.

  18. Path integral solution of the Dirichlet problem

    International Nuclear Information System (INIS)

    LaChapelle, J.

    1997-01-01

    A scheme for functional integration developed by Cartier/DeWitt-Morette is first reviewed and then employed to construct the path integral representation for the solution of the Dirichlet problem in terms of first exit time. The path integral solution is then applied to calculate the fixed-energy point-to-point transition amplitude both in configuration and phase space. The path integral solution can also be derived using physical principles based on Feynman close-quote s original reasoning. We check that the Fourier transform in energy of the fixed-energy point-to-point transition amplitude gives the well known time-dependent transition amplitude, and calculate the WKB approximation. copyright 1997 Academic Press, Inc

  19. Reaction path simulations in multicomponent materials

    International Nuclear Information System (INIS)

    Seifert, H.J.

    1999-01-01

    The CALPHAD (calculation of phase diagrams) method is used in combination with selected experimental investigations to derive reaction paths in multicomponent systems. The method is illustrated by applying computerized thermodynamic databases and suitable software to explain quantitatively the thermal degradation of precursor-derived Si-C-N ceramics and the nitridation of titanium carbide. Reaction sequences in the Si 3 N 4 -SiC-TiC x N l-x -C-N system are illustrated by graphical representation of compatibility regions and indicated reaction paths. From these results the experimentally known microstructure development of TiC reinforced Si 3 N 4 ceramics is explained and quantitative information is provided to optimize the microstructure of such materials. The concept of reaction paths for the understanding of rapid solidification processes is shown by the example of AZ type Mg casting alloys. (orig.)

  20. Methodological application of Location of service Public Bike. Service MUyBICI of Murcia

    Energy Technology Data Exchange (ETDEWEB)

    LiÑan Ruiz, R.J.; Berenguer Sempere, F.J.; Vera Lopez, J.A.; Pabon Dueñas, A.B.; Merino Cordoba, S.

    2016-07-01

    The use of non-motorized means of transport such as the bicycle, brings many benefits to the user and for the city in terms of costs and health for the first and decreased environmental pollution for the city. To find the optimal location for placement of the different parties to public bike, aims to attract the usual user and potential, have the feasibility of switching modes without any restrictions, while generating the ability to balance the demands users towards sustainable modes of transport, with special attention to cycling and public bike loan. The implementation of this methodology is performed in the municipality of Murcia (Spain) due to the opening of its public bicycle system MUyBICI which will have 60 benches, with a total of 1,200 posts anchor and put into circulation 600 public bicycles. As selection criteria to be considered for the optimal location of the beds, the existing network of bike paths were considered, roads used by all users of the public highway, a description of travel and a database information with different land uses and socioeconomic data transport areas. In this paper an analysis model and application for optimal design of banking locations for Murcia MUyBICI service occurs. Specifically, they define what are the best locations to attract a larger number of users, in order to achieve a change in the percentage of the modal split of the municipality, increasing the number of users MUyBICI service. This work comes under the direction of the Bicycle Office of Murcia, part of the ALEM (Local Agency for Energy and Environment) service under the Department of Environment of the City of Murcia. (Author)

  1. OLBS: Offline location based services

    OpenAIRE

    Coelho, P; Ana Aguiar; João Correia Lopes

    2011-01-01

    Most existing location-based services rely on ubiquitous connectivity to deliver location-based contents to the users. However, connectivity is not available anywhere at anytime even in urban centres. Underground, indoors, remote areas, and foreign countries are examples situations where users commonly do not have guaranteed connectivity but could profit from location-based contents. In this work, we propose an open platform for publishing, distributing and maintaining location-based contents...

  2. Tornado intensity estimated from damage path dimensions.

    Directory of Open Access Journals (Sweden)

    James B Elsner

    Full Text Available The Newcastle/Moore and El Reno tornadoes of May 2013 are recent reminders of the destructive power of tornadoes. A direct estimate of a tornado's power is difficult and dangerous to get. An indirect estimate on a categorical scale is available from a post-storm survery of the damage. Wind speed bounds are attached to the scale, but the scale is not adequate for analyzing trends in tornado intensity separate from trends in tornado frequency. Here tornado intensity on a continuum is estimated from damage path length and width, which are measured on continuous scales and correlated to the EF rating. The wind speeds on the EF scale are treated as interval censored data and regressed onto the path dimensions and fatalities. The regression model indicates a 25% increase in expected intensity over a threshold intensity of 29 m s(-1 for a 100 km increase in path length and a 17% increase in expected intensity for a one km increase in path width. The model shows a 43% increase in the expected intensity when fatalities are observed controlling for path dimensions. The estimated wind speeds correlate at a level of .77 (.34, .93 [95% confidence interval] with a small sample of wind speeds estimated independently from a doppler radar calibration. The estimated wind speeds allow analyses to be done on the tornado database that are not possible with the categorical scale. The modeled intensities can be used in climatology and in environmental and engineering applications. Research is needed to understand the upward trends in path length and width.

  3. Tornado intensity estimated from damage path dimensions.

    Science.gov (United States)

    Elsner, James B; Jagger, Thomas H; Elsner, Ian J

    2014-01-01

    The Newcastle/Moore and El Reno tornadoes of May 2013 are recent reminders of the destructive power of tornadoes. A direct estimate of a tornado's power is difficult and dangerous to get. An indirect estimate on a categorical scale is available from a post-storm survery of the damage. Wind speed bounds are attached to the scale, but the scale is not adequate for analyzing trends in tornado intensity separate from trends in tornado frequency. Here tornado intensity on a continuum is estimated from damage path length and width, which are measured on continuous scales and correlated to the EF rating. The wind speeds on the EF scale are treated as interval censored data and regressed onto the path dimensions and fatalities. The regression model indicates a 25% increase in expected intensity over a threshold intensity of 29 m s(-1) for a 100 km increase in path length and a 17% increase in expected intensity for a one km increase in path width. The model shows a 43% increase in the expected intensity when fatalities are observed controlling for path dimensions. The estimated wind speeds correlate at a level of .77 (.34, .93) [95% confidence interval] with a small sample of wind speeds estimated independently from a doppler radar calibration. The estimated wind speeds allow analyses to be done on the tornado database that are not possible with the categorical scale. The modeled intensities can be used in climatology and in environmental and engineering applications. Research is needed to understand the upward trends in path length and width.

  4. Branch and peg algorithms for the simple plant location problem

    NARCIS (Netherlands)

    Goldengorin, B.; Ghosh, D.; Sierksma, G.

    The simple plant location problem is a well-studied problem in combinatorial optimization. It is one of deciding where to locate a set of plants so that a set of clients can be supplied by them at the minimum cost. This problem often appears as a subproblem in other combinatorial problems. Several

  5. Branch and peg algorithms for the simple plant location problem

    NARCIS (Netherlands)

    Goldengorin, Boris; Ghosh, Diptesh; Sierksma, Gerard

    2001-01-01

    The simple plant location problem is a well-studied problem in combinatorial optimization. It is one of deciding where to locate a set of plants so that a set of clients can be supplied by them at the minimum cost. This problem of ten appears as a subproblem in other combinatorial problems. Several

  6. LOCAT - A Data Retrieval Program.

    Science.gov (United States)

    1984-12-01

    onoitode of scified location - P C RADIUS - maximum distance between specified location and C file locationsC . ’ CONNON /LOCN/ LOCLAT, LOCLNG, RADIUS...rrr’, ,r:.- r -’ - r- rJ Z. . . , . -.-. - - - - - - -- , -• .. . . FILMED 8-85 DTIC .-. ... , ,- . . . . ...: .--. :,.:. ..-..-- ,-, .-..-...

  7. The transformation techniques in path integration

    International Nuclear Information System (INIS)

    Inomata, A.

    1989-01-01

    In this paper general remarks are made concerning the time transformation techniques in path integration and their implementations. Time transformations may be divided into two classes: global (integrable) time transformations and local (nonintegrable) time transformations. Although a brief account of global time transformations is given, attention is focused on local transformations. First, time transformations in the classical Kepler problem are reviewed. Then, problems encountered in implementing a local time transformation in quantum mechanics are analyzed. A several propositions pertinent to the implementation of local time transformations, particularly basic to the local time rescaling trick in a discretized path integral, are presented

  8. Canonical transformations and hamiltonian path integrals

    International Nuclear Information System (INIS)

    Prokhorov, L.V.

    1982-01-01

    Behaviour of the Hamiltonian path integrals under canonical transformations produced by a generator, is investigated. An exact form is determined for the kernel of the unitary operator realizing the corresponding quantum transformation. Equivalence rules are found (the Hamiltonian formalism, one-dimensional case) enabling one to exclude non-standard terms from the action. It is shown that the Hamiltonian path integral changes its form under cononical transformations: in the transformed expression besides the classical Hamiltonian function there appear some non-classical terms

  9. Field theory a path integral approach

    CERN Document Server

    Das, Ashok

    2006-01-01

    This unique book describes quantum field theory completely within the context of path integrals. With its utility in a variety of fields in physics, the subject matter is primarily developed within the context of quantum mechanics before going into specialized areas.Adding new material keenly requested by readers, this second edition is an important expansion of the popular first edition. Two extra chapters cover path integral quantization of gauge theories and anomalies, and a new section extends the supersymmetry chapter, where singular potentials in supersymmetric systems are described.

  10. Graphs with not all possible path-kernels

    DEFF Research Database (Denmark)

    Aldred, Robert; Thomassen, Carsten

    2004-01-01

    The Path Partition Conjecture states that the vertices of a graph G with longest path of length c may be partitioned into two parts X and Y such that the longest path in the subgraph of G induced by X has length at most a and the longest path in the subgraph of G induced by Y has length at most b...

  11. Study on k-shortest paths with behavioral impedance domain from the intermodal public transportation system perspective

    OpenAIRE

    Pereira, Hernane Borges de Barros; Pérez Vidal, Lluís; Lozada, Eleazar G. Madrid

    2003-01-01

    Behavioral impedance domain consists of a theory on route planning for pedestrians, within which constraint management is considered. The goal of this paper is to present the k-shortest path model using the behavioral impedance approach. After the mathematical model building, optimization problem and resolution problem by a behavioral impedance algorithm, it is discussed how behavioral impedance cost function is embedded in the k-shortest path model. From the pedestrian's route planning persp...

  12. Global Cities, Ownership Structures, and Location Choice

    DEFF Research Database (Denmark)

    Geisler Asmussen, Christian; Nielsen, Bo Bernhard; Goerzen, Anthony

    2018-01-01

    Purpose: In this paper, we develop a more nuanced view of subnational location choice with a particular focus on global cities. We argue that multinational firms may use global cities to establish bridgeheads—subsidiaries at intermediate levels of the ownership chain that enable further internati......Purpose: In this paper, we develop a more nuanced view of subnational location choice with a particular focus on global cities. We argue that multinational firms may use global cities to establish bridgeheads—subsidiaries at intermediate levels of the ownership chain that enable further...... of these investments are associated with micro-location choices in a host country. Findings: We find that there are substantial differences between the types, roles, activities, and geographic origins of the firms locating in different areas, and in the ownership structures spanning them. We propose that this has...... managerial and theoretical implications which may be understood based on an organizing framework describing a tradeoff between the pursuit of global connectivity and local density on the one hand, and cost control on the other. Research limitations/implications: Empirical work on foreign location choices...

  13. A Sun Path Observation System Based on Augment Reality and Mobile Learning

    OpenAIRE

    Tarng, Wernhuar; Ou, Kuo-Liang; Lu, Yun-Chen; Shih, Yi-Syuan; Liou, Hsin-Hun

    2018-01-01

    This study uses the augmented reality technology and sensor functions of GPS, electronic compass, and three-axis accelerometer on mobile devices to develop a Sun path observation system for applications in astronomy education. The orientation and elevation of the Sun can be calculated by the system according to the user’s location and local time to simulate the Sun path. When holding the mobile device toward the sky, the screen will show the virtual Sun at the same position as that of the rea...

  14. Intercooler flow path for gas turbines: CFD design and experiments

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, A.K.; Gollahalli, S.R.; Carter, F.L. [Univ. of Oklahoma, Norman, OK (United States)] [and others

    1995-10-01

    The Advanced Turbine Systems (ATS) program was created by the U.S. Department of Energy to develop ultra-high efficiency, environmentally superior, and cost competitive gas turbine systems for generating electricity. Intercooling or cooling of air between compressor stages is a feature under consideration in advanced cycles for the ATS. Intercooling entails cooling of air between the low pressure (LP) and high pressure (BP) compressor sections of the gas turbine. Lower air temperature entering the HP compressor decreases the air volume flow rate and hence, the compression work. Intercooling also lowers temperature at the HP discharge, thus allowing for more effective use of cooling air in the hot gas flow path. The thermodynamic analyses of gas turbine cycles with modifications such as intercooling, recuperating, and reheating have shown that intercooling is important to achieving high efficiency gas turbines. The gas turbine industry has considerable interest in adopting intercooling to advanced gas turbines of different capacities. This observation is reinforced by the US Navys Intercooled-Recuperative (ICR) gas turbine development program to power the surface ships. In an intercooler system, the air exiting the LP compressor must be decelerated to provide the necessary residence time in the heat exchanger. The cooler air must subsequently be accelerated towards the inlet of the HP compressor. The circumferential flow nonuniformities inevitably introduced by the heat exchanger, if not isolated, could lead to rotating stall in the compressors, and reduce the overall system performance and efficiency. Also, the pressure losses in the intercooler flow path adversely affect the system efficiency and hence, must be minimized. Thus, implementing intercooling requires fluid dynamically efficient flow path with minimum flow nonuniformities and consequent pressure losses.

  15. Shortest path problem on a grid network with unordered intermediate points

    Science.gov (United States)

    Saw, Veekeong; Rahman, Amirah; Eng Ong, Wen

    2017-10-01

    We consider a shortest path problem with single cost factor on a grid network with unordered intermediate points. A two stage heuristic algorithm is proposed to find a feasible solution path within a reasonable amount of time. To evaluate the performance of the proposed algorithm, computational experiments are performed on grid maps of varying size and number of intermediate points. Preliminary results for the problem are reported. Numerical comparisons against brute forcing show that the proposed algorithm consistently yields solutions that are within 10% of the optimal solution and uses significantly less computation time.

  16. Location theory a unified approach

    CERN Document Server

    Nickel, Stefan

    2006-01-01

    Although modern location theory is now more than 90 years old, the focus of researchers in this area has been mainly problem oriented. However, a common theory, which keeps the essential characteristics of classical location models, is still missing.This monograph addresses this issue. A flexible location problem called the Ordered Median Problem (OMP) is introduced. For all three main subareas of location theory (continuous, network and discrete location) structural properties of the OMP are presented and solution approaches provided. Numerous illustrations and examples help the reader to bec

  17. 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.

  18. Cost Behavior

    DEFF Research Database (Denmark)

    Hoffmann, Kira

    The objective of this dissertation is to investigate determinants and consequences of asymmetric cost behavior. Asymmetric cost behavior arises if the change in costs is different for increases in activity compared to equivalent decreases in activity. In this case, costs are termed “sticky......” if the change is less when activity falls than when activity rises, whereas costs are termed “anti-sticky” if the change is more when activity falls than when activity rises. Understanding such cost behavior is especially relevant for decision-makers and financial analysts that rely on accurate cost information...... to facilitate resource planning and earnings forecasting. As such, this dissertation relates to the topic of firm profitability and the interpretation of cost variability. The dissertation consists of three parts that are written in the form of separate academic papers. The following section briefly summarizes...

  19. Location of Urban Logistic Terminals as Hub Location Problem

    Directory of Open Access Journals (Sweden)

    Jasmina Pašagić Škrinjar

    2012-09-01

    Full Text Available In this paper the problems of locating urban logistic terminals are studied as hub location problems that due to a large number of potential nodes in big cities belong to hard non-polynomial problems, the so-called NP-problems. The hub location problems have found wide application in physical planning of transport and telecommunication systems, especially systems of fast delivery, networks of logistic and distribution centres and cargo traffic terminals of the big cities, etc. The paper defines single and multiple allocations and studies the numerical examples. The capacitated single allocation hub location problems have been studied, with the provision of a mathematical model of selecting the location for the hubs on the network. The paper also presents the differences in the possibilities of implementing the exact and heuristic methods to solve the actual location problems of big dimensions i.e. hub problems of the big cities.

  20. On the structure of path-like trees

    OpenAIRE

    Muntaner Batle, Francesc Antoni; Rius Font, Miquel

    2007-01-01

    We study the structure of path-like trees. In order to do this, we introduce a set of trees that we call expandable trees. In this paper we also generalize the concept of path-like trees and we call such generalization generalized path-like trees. As in the case of path-like trees, generalized path-like trees, have very nice labeling properties.

  1. Effects of T-type Channel on Natural Convection Flows in Airflow-Path of Concrete Storage Cask

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Gyeong Uk; Kim, Hyoung Jin; Cho, Chun Hyung [KORAD, Daejeon (Korea, Republic of)

    2016-05-15

    The natural convection flows occurring in airflow-path are not simple due to complex flow-path configurations such as horizontal ducts, bent tube and annular flow-path. In addition, 16 T type channels acting as the shroud are attached vertically and 16 channel supporting the canister are attached horizontally on the inner surface of over-pack. The existence and nonexistence of T type channels have influences on the flow fields in airflow- path. The concrete storage cask has to satisfy the requirements to secure the thermal integrity under the normal, off-normal, and accident conditions. The present work is aiming at investigating the effects of T type channels on the flows in airflow-path under the normal conditions using the FLUENT 16.1 code. In order to focus on the flows in airflow-path, fuel regions in the canister are regarded as a single cylinder with heat sources and other components are fully modeled. This study investigated the flow fields in airflow-path of concrete storage cask, numerically. It was found that excepting for the fuel regions, maximum temperatures on other components were evaluated below allowable values. The location of maximum velocities depended on support channels, T type channels and flow area. The flows through air inlets developed along annular flow- path with forming the hot plumes. According to the existence and nonexistence of T type channel, the plume behavior showed the different flow patterns.

  2. Uncapacitated facility location problem with self-serving demands

    Directory of Open Access Journals (Sweden)

    E Monabbati

    2013-12-01

    Full Text Available In classical uncapacitated facility location problems (UFLP the goal is to satisfy requirements of some demand points by setting up some servers, among potential facility locations, such that the total cost including service costs and fixed costs are minimized. In this paper a generalization of UFLP is considered in which some demand points, called self-serving, could be served exclusively by a new server at that point. Numerical experiments show that near optimal solutions are achieved by the proposed method.

  3. On Pure and (approximate) Strong Equilibria of Facility Location Games

    DEFF Research Database (Denmark)

    Hansen, Thomas Dueholm; Telelis, Orestis A.

    2008-01-01

    We study social cost losses in Facility Location games, where n selfish agents install facilities over a network and connect to them, so as to forward their local demand (expressed by a non-negative weight per agent). Agents using the same facility share fairly its installation cost, but every...... agent pays individually a (weighted) connection cost to the chosen location. We study the Price of Stability (PoS) of pure Nash equilibria and the Price of Anarchy of strong equilibria (SPoA), that generalize pure equilibria by being resilient to coalitional deviations. For unweighted agents on metric...

  4. Drosophila learn efficient paths to a food source.

    Science.gov (United States)

    Navawongse, Rapeechai; Choudhury, Deepak; Raczkowska, Marlena; Stewart, James Charles; Lim, Terrence; Rahman, Mashiur; Toh, Alicia Guek Geok; Wang, Zhiping; Claridge-Chang, Adam

    2016-05-01

    Elucidating the genetic, and neuronal bases for learned behavior is a central problem in neuroscience. A leading system for neurogenetic discovery is the vinegar fly Drosophila melanogaster; fly memory research has identified genes and circuits that mediate aversive and appetitive learning. However, methods to study adaptive food-seeking behavior in this animal have lagged decades behind rodent feeding analysis, largely due to the challenges presented by their small scale. There is currently no method to dynamically control flies' access to food. In rodents, protocols that use dynamic food delivery are a central element of experimental paradigms that date back to the influential work of Skinner. This method is still commonly used in the analysis of learning, memory, addiction, feeding, and many other subjects in experimental psychology. The difficulty of microscale food delivery means this is not a technique used in fly behavior. In the present manuscript we describe a microfluidic chip integrated with machine vision and automation to dynamically control defined liquid food presentations and sensory stimuli. Strikingly, repeated presentations of food at a fixed location produced improvements in path efficiency during food approach. This shows that improved path choice is a learned behavior. Active control of food availability using this microfluidic system is a valuable addition to the methods currently available for the analysis of learned feeding behavior in flies. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  5. Gas-path leakage seal for a gas turbine

    Science.gov (United States)

    Wolfe, C.E.; Dinc, O.S.; Bagepalli, B.S.; Correia, V.H.; Aksit, M.F.

    1996-04-23

    A gas-path leakage seal is described for generally sealing a gas-path leakage-gap between spaced-apart first and second members of a gas turbine (such as combustor casing segments). The seal includes a generally imperforate foil-layer assemblage which is generally impervious to gas and is located in the leakage-gap. The seal also includes a cloth-layer assemblage generally enclosingly contacting the foil-layer assemblage. In one seal, the first edge of the foil-layer assemblage is left exposed, and the foil-layer assemblage resiliently contacts the first member near the first edge to reduce leakage in the ``plane`` of the cloth-layer assemblage under conditions which include differential thermal growth of the two members. In another seal, such leakage is reduced by having a first weld-bead which permeates the cloth-layer assemblage, is attached to the metal-foil-layer assemblage near the first edge, and unattachedly contacts the first member. 4 figs.

  6. Location, Location, Location: Does Place Provide the Opportunity for Differentiation for Universities?

    Science.gov (United States)

    Winter, Emma; Thompson-Whiteside, Helen

    2017-01-01

    The fiercely competitive HE market has led HEIs to invest significant resources in building a distinct identity. An HEI's location forms an inherent part of its identity and the uniqueness of location offers an opportunity to differentiate. However there has been limited examination of how location is used by HEIs and little consideration of how…

  7. Spatio-temporal structure, path characteristics and perceptual grouping in immediate serial spatial recall

    Directory of Open Access Journals (Sweden)

    Carlo De Lillo

    2016-11-01

    Full Text Available Immediate serial spatial recall measures the ability to retain sequences of locations in short-term memory and is considered the spatial equivalent of digit span. It is tested by requiring participants to reproduce sequences of movements performed by an experimenter or displayed on a monitor. Different organizational factors dramatically affect serial spatial recall but they are often confounded or underspecified. Untangling them is crucial for the characterization of working-memory models and for establishing the contribution of structure and memory capacity to spatial span. We report five experiments assessing the relative role and independence of factors that have been reported in the literature. Experiment 1 disentangled the effects of spatial clustering and path-length by manipulating the distance of items displayed on a touchscreen monitor. Long-path sequences segregated by spatial clusters were compared with short-path sequences not segregated by clusters. Recall was more accurate for sequences segregated by clusters independently from path-length. Experiment 2 featured conditions where temporal pauses were introduced between or within cluster boundaries during the presentation of sequences with the same paths. Thus, the temporal structure of the sequences was either consistent or inconsistent with a hierarchical representation based on segmentation by spatial clusters but the effect of structure could not be confounded with effects of path-characteristics. Pauses at cluster boundaries yielded more accurate recall, as predicted by a hierarchical model. In Experiment 3, the systematic manipulation of sequence structure, path-length and presence of path-crossings of sequences showed that structure explained most of the variance, followed by the presence/absence of path-crossings, and path-length. Experiments 4 and 5 replicated the results of the previous experiments in immersive virtual reality navigation tasks where the viewpoint of the

  8. Kinematics and Path Following Control of an Articulated Drum Roller

    Science.gov (United States)

    BIAN, Yongming; YANG, Meng; FANG, Xiaojun; WANG, Xiahui

    2017-07-01

    Automatic navigation of an articulated drum roller, which is an articulated steering type vehicle widely used in the construction industry, is highly expected for operation cost reduction and improvement of work efficiency. In order to achieve the path following control, considering that its steering system is articulated steering and two frames are articulated by an active revolute joint, a kinematic model and an error dynamic state-space equation of an articulated drum roller are proposed. Besides, a state-feedback control law based on Lyapunov stability theory is also designed, which can be proved to achieve the purpose of control by the analysis of stability. What's more, to evaluate the performance of the proposed method, simulation under the MATLAB/Simulink and experiments using positioning algorithm and errors correction at the uneven construction site are performed, with initial displacement error (-1.5 m), heading error (-0.11 rad) and steering angle (-0.19 rad). Finally, simulation and experimental results show that the errors and steering angle can decrease gradually, and converge to zero with time. Meanwhile, the control input is not saturated. An articulated drum roller can lock into a desired path with the proposed method in uneven fields.

  9. The High Field Path to Practical Fusion Energy

    Science.gov (United States)

    Mumgaard, Robert; Whyte, D.; Greenwald, M.; Hartwig, Z.; Brunner, D.; Sorbom, B.; Marmar, E.; Minervini, J.; Bonoli, P.; Irby, J.; Labombard, B.; Terry, J.; Vieira, R.; Wukitch, S.

    2017-10-01

    We propose a faster, lower cost development path for fusion energy enabled by high temperature superconductors, devices at high magnetic field, innovative technologies and modern approaches to technology development. Timeliness, scale, and economic-viability are the drivers for fusion energy to combat climate change and aid economic development. The opportunities provided by high-temperature superconductors, innovative engineering and physics, and new organizational structures identified over the last few years open new possibilities for realizing practical fusion energy that could meet mid-century de-carbonization needs. We discuss re-factoring the fusion energy development path with an emphasis on concrete risk retirement strategies utilizing a modular approach based on the high-field tokamak that leverages the broader tokamak physics understanding of confinement, stability, and operational limits. Elements of this plan include development of high-temperature superconductor magnets, simplified immersion blankets, advanced long-leg divertors, a compact divertor test tokamak, efficient current drive, modular construction, and demountable magnet joints. An R&D plan culminating in the construction of an integrated pilot plant and test facility modeled on the ARC concept is presented.

  10. Propagation Effects in Space/Earth Paths.

    Science.gov (United States)

    1980-08-01

    0 h In both integrals ds is a differential of curved ray path and includes refractive bending. In either integral, the factor aTar is, by the Rayleigh...interference. Ionospheric modification may also result from the emission of exhaust effluents from HLLV’s. The associated changes in ionospherio chemistry can

  11. Gender Differences in Career Paths in Banking.

    Science.gov (United States)

    Morgan, Sandra; And Others

    1993-01-01

    Analyzed career paths of middle managers in bank. Study of matched pairs found that men (n=25) advanced faster and reached middle management through fewer promotions and positions than did women (n=25). Men had significantly more work experience outside of banking. In banking careers, men held more jobs in lending, whereas women occupied more…

  12. Quad-rotor flight path energy optimization

    Science.gov (United States)

    Kemper, Edward

    Quad-Rotor unmanned areal vehicles (UAVs) have been a popular area of research and development in the last decade, especially with the advent of affordable microcontrollers like the MSP 430 and the Raspberry Pi. Path-Energy Optimization is an area that is well developed for linear systems. In this thesis, this idea of path-energy optimization is extended to the nonlinear model of the Quad-rotor UAV. The classical optimization technique is adapted to the nonlinear model that is derived for the problem at hand, coming up with a set of partial differential equations and boundary value conditions to solve these equations. Then, different techniques to implement energy optimization algorithms are tested using simulations in Python. First, a purely nonlinear approach is used. This method is shown to be computationally intensive, with no practical solution available in a reasonable amount of time. Second, heuristic techniques to minimize the energy of the flight path are tested, using Ziegler-Nichols' proportional integral derivative (PID) controller tuning technique. Finally, a brute force look-up table based PID controller is used. Simulation results of the heuristic method show that both reliable control of the system and path-energy optimization are achieved in a reasonable amount of time.

  13. Taking a Technological Path to Poetry Prewriting.

    Science.gov (United States)

    Roberts, Sherron Killingsworth

    2002-01-01

    Offers a strong rationale for the idea that the journey of writing good poetry begins on a path that infuses technology into the first stage of the writing process. Presents several ideas of ways to incorporate technology into the prewriting poetry experience. Concludes that by making technology an ingredient, the true potential for synergy…

  14. Unidirectional Motion of Vehicle on Sinusoidal Path

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 17; Issue 4. Unidirectional Motion of Vehicle on Sinusoidal Path: Can it Cause Illusory Forward and Backward Motion? Anuj Bhatnagar. Classroom Volume 17 Issue 4 April 2012 pp 387-392 ...

  15. Feynman path integral formulation of quantum mechanics

    International Nuclear Information System (INIS)

    Mizrahi, M.M.

    1975-01-01

    The subject of this investigation is Feynman's path integral quantization scheme, which is a powerful global formalism with great intuitive appeal. It stems from the simple idea that a probability amplitude for a system to make a transition between two states is the ''sum'' of the amplitudes for all the possible ways the transition can take place

  16. Path integral quantization of parametrized field theory

    International Nuclear Information System (INIS)

    Varadarajan, Madhavan

    2004-01-01

    Free scalar field theory on a flat spacetime can be cast into a generally covariant form known as parametrized field theory in which the action is a functional of the scalar field as well as the embedding variables which describe arbitrary, in general curved, foliations of the flat spacetime. We construct the path integral quantization of parametrized field theory in order to analyze issues at the interface of quantum field theory and general covariance in a path integral context. We show that the measure in the Lorentzian path integral is nontrivial and is the analog of the Fradkin-Vilkovisky measure for quantum gravity. We construct Euclidean functional integrals in the generally covariant setting of parametrized field theory using key ideas of Schleich and show that our constructions imply the existence of nonstandard 'Wick rotations' of the standard free scalar field two-point function. We develop a framework to study the problem of time through computations of scalar field two-point functions. We illustrate our ideas through explicit computation for a time independent (1+1)-dimensional foliation. Although the problem of time seems to be absent in this simple example, the general case is still open. We discuss our results in the contexts of the path integral formulation of quantum gravity and the canonical quantization of parametrized field theory

  17. Feature based omnidirectional sparse visual path following

    OpenAIRE

    Goedemé, Toon; Tuytelaars, Tinne; Van Gool, Luc; Vanacker, Gerolf; Nuttin, Marnix

    2005-01-01

    Goedemé T., Tuytelaars T., Van Gool L., Vanacker G., Nuttin M., ''Feature based omnidirectional sparse visual path following'', Proceedings IEEE/RSJ international conference on intelligent robots and systems - IROS2005, pp. 1003-1008, August 2-6, 2005, Edmonton, Alberta, Canada.

  18. Certified higher-order recursive path ordering

    NARCIS (Netherlands)

    Koprowski, A.; Pfenning, F.

    2006-01-01

    The paper reports on a formalization of a proof of wellfoundedness of the higher-order recursive path ordering (HORPO) in the proof checker Coq. The development is axiom-free and fully constructive. Three substantive parts that could be used also in other developments are the formalizations of the

  19. Path-breaking books in regional science

    NARCIS (Netherlands)

    Waldorf, BS

    This article presents a collection of regional science books that long-standing members of the Regional Science Association International (RSAI) identified as path-breaking books. The most frequently nominated books include the "classics" by Isard, the seminal books in urban economics by Alonso,

  20. Covariant path integrals on hyperbolic surfaces

    Science.gov (United States)

    Schaefer, Joe

    1997-11-01

    DeWitt's covariant formulation of path integration [B. De Witt, "Dynamical theory in curved spaces. I. A review of the classical and quantum action principles," Rev. Mod. Phys. 29, 377-397 (1957)] has two practical advantages over the traditional methods of "lattice approximations;" there is no ordering problem, and classical symmetries are manifestly preserved at the quantum level. Applying the spectral theorem for unbounded self-adjoint operators, we provide a rigorous proof of the convergence of certain path integrals on Riemann surfaces of constant curvature -1. The Pauli-DeWitt curvature correction term arises, as in DeWitt's work. Introducing a Fuchsian group Γ of the first kind, and a continuous, bounded, Γ-automorphic potential V, we obtain a Feynman-Kac formula for the automorphic Schrödinger equation on the Riemann surface ΓH. We analyze the Wick rotation and prove the strong convergence of the so-called Feynman maps [K. D. Elworthy, Path Integration on Manifolds, Mathematical Aspects of Superspace, edited by Seifert, Clarke, and Rosenblum (Reidel, Boston, 1983), pp. 47-90] on a dense set of states. Finally, we give a new proof of some results in C. Grosche and F. Steiner, "The path integral on the Poincare upper half plane and for Liouville quantum mechanics," Phys. Lett. A 123, 319-328 (1987).