WorldWideScience

Sample records for circle cliffs deposit

  1. Detailed View of Cliff-face in the North Polar Layered Deposits

    Science.gov (United States)

    1998-01-01

    On Earth, geologists use layers of rock to 'read' the history of our planet. Where rocks were initially formed as layers of sediment, the historic record of Earth is deciphered by knowing that older layers are found beneath the younger layers. Scientists investigating changes in Earth's climate over the past few million years also use this principle to examine cores of ice from Greenland and Antarctica. Layered rock and layered polar deposits on Mars may also preserve a comparable record of that planet's geologic and environmental history.The martian north and south polar regions are covered by large areas of layered deposits. Since their discovery in the early 1970's, these polar layered deposits have been cited as the best evidence that the martian climate experiences cyclic changes over time. It was proposed that detailed investigation of the polar layers (e.g., by landers and/or human beings) would reveal a climate record of Mars in much the same way that ice cores from Antarctica are used to study past climates on Earth. On January 3, 1999, NASA's Mars Polar Lander and Deep Space 2 Penetrators will launch on a journey to study the upper layers of these deposits in the martian southern hemisphere.Meanwhile, investigation of the north polar layered deposits has advanced significantly this year with the acquisition of MGS data. The Mars Orbiter Laser Altimeter acquired new topographic profiles over the north polar deposits in June and early July, 1998, and dozens of new high resolution images were taken by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) from mid-July to mid-September, 1998. When it was proposed to NASA in 1985, one of the original objectives of MOC was to determine whether the polar layered deposits--then thought to consist of 10 to 100 layers each between 10 and 100 meters (33 to 330 feet) thick--have more and thinner layers in them. The layers were proposed to have formed by slow accumulation of dust and ice--perhaps only 100

  2. Cliffs User Manual

    CERN Document Server

    Tolkova, Elena

    2014-01-01

    Cliffs is an open-source relative of MOST (Method Of Splitting Tsunamis) numerical model, implemented as described in (Tolkova, 2014, Pure and Appl. Geophys., 171(9), 2289-2314). Cliffs features: Shallow-Water approximation with an option to manipulate numerical dispersion; Use of Cartesian or spherical (lon/lat) coordinates; 1D and 2D configurations; Structured co-located grid with (optionally) varying spacing; Runup on land; Initial conditions or boundary forcing; Grid nesting with one-way coupling; Parallelized with OpenMP; NetCDF format of input/output data. This user manual accompanies Cliffs code distribution.

  3. Dynamics of a cliff top dune

    Science.gov (United States)

    Rasmussen, K. R.

    2012-12-01

    Morphological changes during more than 100 years have been investigated for a cliff-top dune complex at Rubjerg at the Danish North Sea coast. Here the lower 50 m of the cliff front is composed of Pleistocene steeply inclined floes of silt and clay with coarse sand in between which gives it a saw-tooth appearance. On top of this the dunes are found for several kilometres along the coastline. Due to erosion by the North Sea the cliff has retreated about 120 m between approximately 1880 and 1970 as indicated from two national surveys, and recent GPS-surveys indicate that erosion is continuing at a similar rate. Nevertheless the cliff top dune complex has survived, but its morphology has undergone some changed. The old maps indicate that around 1880 the dune complex was composed of several up to about 20 m high dunes streamlined in the East-West direction which is parallel to the prevailing wind direction. When protective planting started during the first half of the 20th Century the cliff top dunes gradually merged together forming a narrow, tall ridge parallel to the shore line with the highest part reaching about 90 m near 1970. In 1993 the highest points along the ridge was almost 95 m high, but then the protective planting was considerably reduced and recent annual GPS-surveys indicate that the dunes respond quickly to this by changing their morphology towards the original appearance. It is remarkable that despite the mass wasting caused by the constant erosion of the cliff front the dunes have remained more or less intact. Theoretical studies of hill flow indicate given the proper geometry of the cliff then suspension of even coarse grains can be a very effective agent for carrying sand from the exposed parts of the cliff front to and beyond the cliff-top. Mostly the sand grains are deposited within some hundred meters downwind of the cliff dune while silt is often carried more than 10 km inland. Field observations indicate that where the dislodged floes and

  4. Flora of the Orange Cliffs of Utah

    Energy Technology Data Exchange (ETDEWEB)

    Shultz, L.M.; Neely, E.E.; Tuhy, J.S.

    1987-04-30

    The Orange Cliffs area, an area rich in oil sands deposits and defined here as part of the Colorado Plateau floristic province, harbors approximately 209 species in 123 genera and 49 families. Because of the potential of exploitation of the oil sands deposits in the area, a species checklist was made and a discussion of physical and floristic aspects of the region is given here. The flora is compared statistically to the San Rafael Swell flora, which is also a subset of the Colorado Plateau. They define six vegetation types and three edaphic communities; these are described and mapped. Of eleven endemic plant species in the Orange Cliffs, three are local and rare. Sites for Astragalus nidularius, A. moencoppensis, and Xylorhiza glabriuscula var. linearifolia are discussed and mapped. 24 references, 3 figures, 3 tables.

  5. Advances in Activity Cliff Research.

    Science.gov (United States)

    Dimova, Dilyana; Bajorath, Jürgen

    2016-05-01

    Activity cliffs, i.e. similar compounds with large potency differences, are of interest from a chemical and informatics viewpoint; as a source of structure-activity relationship information, for compound optimization, and activity prediction. Herein, recent highlights of activity cliff research are discussed including studies that have further extended our understanding of activity cliffs, yielded unprecedented insights, or paved the way for practical applications.

  6. Research circles

    DEFF Research Database (Denmark)

    Nordentoft, Helle Merete; Thomsen, Rie; Möller, Jonas

    lifelong guidance policies. This paper presents `research circles´ as a way to develop guidance practices through long-term research relationships between practice and research. Research circles support a bottom up approach to policy development just like ELGPN considers to be necessary and required...... in career guidance development. In the paper we draw on the preliminary findings from an ongoing Nordic project: “The future of career guidance and educational counselling”. Specifically, we explore the career guidance practitioners´ response to research circles as means to professional development. We...... argue that this practicebased way of organizing research facilitates learning, and potentially, qualifies practice. The collaboration between researchers and practitioners in the research circle fosters a joint venture and an academic perspective on practice, which stimulates practitioners to step out...

  7. Solving Problems through Circles

    Science.gov (United States)

    Grahamslaw, Laura; Henson, Lisa H.

    2015-01-01

    Several problem-solving interventions that utilise a "circle" approach have been applied within the field of educational psychology, for example, Circle Time, Circle of Friends, Sharing Circles, Circle of Adults and Solution Circles. This research explored two interventions, Solution Circles and Circle of Adults, and used thematic…

  8. River response to climate and sea level changes during the Late Saalian/Early Eemian in northern Poland – a case study of meandering river deposits in the Chłapowo cliff section

    Directory of Open Access Journals (Sweden)

    Moskalewicz Damian

    2016-03-01

    Full Text Available Fluvial sediments in the Chłapowo cliff section were studied in order to reconstruct their palaeoflow conditions and stratigraphical position. Lithofacies, textural and palaeohydraulic analyses as well as luminescence dating were performed so as to achieve the aim of study. Sedimentary successions were identified as a record of point bar cycles. The fluvial environment probably functioned during the latest Saalian, shortly after the retreat of the Scandinavian Ice Sheet. Discharge outflow was directed to the northwest. The river used the older fluvioglacial valley and probably was directly connected to the Eem Sea. Good preservation and strong aggradation of point-bar cycles were related to a rapid relative base level rise. The meandering river sediments recognised showed responses to climate and sea level changes as illustrated by stratigraphical, morphological and sedimentological features of the strata described. The present study also revealed several insights into proper interpretation of meandering fluvial successions, in which the most important were: specific lithofacies assemblage of GSt (St, Sp → Sl → SFrc → Fm (SFr and related architectural elements: channel/sandy bedforms CH/SB → lateral accretion deposits LA → floodplain fines with crevasse splays FF (CS; upward-fining grain size and decreasing content of denser heavy minerals; estimated low-energy flow regime with a mean depth of 1.6–3.3 m, a Froude number of 0.2–0.4 and a sinuosity of 1.5.

  9. Literature Circles.

    Science.gov (United States)

    Katz, Claudia Anne; Kuby, Sue Ann

    2002-01-01

    Describes the use of literature circles, a student-led reading and discussion method that encourages students to see stories in various ways. Explains the student selection of titles, roles of group members, and collaborative projects that complete the activity. (LRW)

  10. Small circles

    DEFF Research Database (Denmark)

    Ling, Richard; Bjelland, Johannes; Sundsøy, Pål

    2014-01-01

    This article examines how we use mobile telephony to maintain our physically and socially closest social circle. The analysis is based on traffic data gathered from Norway using approximately 24 million calls and texts made by private individuals. Previous research has shown that our temporal and...

  11. Activity cliff networks for medicinal chemistry.

    Science.gov (United States)

    Stumpfe, Dagmar; Bajorath, Jürgen

    2014-08-01

    Network representations are widely used in bioinformatics but have only been little explored in chemistry. Thus far, only a few attempts have been made to generate and analyze compound networks. Among these are the first activity cliff networks. In medicinal chemistry, activity cliffs are focal points of structure-activity relationships (SAR) analysis. Activity cliffs have generally been defined as pairs of structurally similar or analogous active compounds that have a large difference in potency against their target. However, most activity cliffs are not formed in isolation but in a coordinated manner involving multiple highly and weakly potent compounds. Recently, a comprehensive activity cliff network has been generated for current public domain bioactive compounds, hence providing a first global view of activity cliff formation. The design of activity cliff networks is discussed herein. From the global activity cliff network, local networks can be extracted for individual compound activity classes that provide graphical access to high-level SAR information for compound optimization efforts.

  12. The Influence of Ephemeral Beaches on Alongshore Variability of Hard-rock Cliff Erosion

    Science.gov (United States)

    Vann Jones, E. C.; Rosser, N. J.; Brain, M.; Varley, S. J.

    2015-12-01

    The role of abrasion of rock cliffs is typically considered in the long-term presence of a beach. During monthly monitoring of hard rock cliff erosion along the North Yorkshire coast, UK, we have observed a number of small ephemeral beaches of highly variable duration and extent. The erosive significance of the temporary presence of sediment at the cliffs is unknown and we set out to examine whether observed alongshore variability in erosion can be linked to the presence of ephemeral beaches. We explore the temporal and spatial variability in sediment deposition and transport along a low-sediment rock coast foreshore, the controlling marine conditions and the effects on cliff erosion. We focus on a 500 m wide embayment set into 70 m high hard rock cliffs consisting of horizontally bedded Jurassic mudstone, shale, siltstone and sandstone. The bay has a wide, shallow gradient foreshore up to 300 m wide with highly variable topography. With the exception of an ephemeral beach (of widths up to approximately 150 m alongshore and 10 m cross-shore) the rock foreshore is typically sand-free, with failed material from the cliffs quickly removed from the cliff toe by the sea leaving only boulders. The high tidal range (6 m) and storm wave environment of the North Sea result in variable marine conditions at the site. We use magnetic sand tracers and a grid of foreshore and cliff face magnets to examine the sand transport across the foreshore and to identify the vertical extent of cliff face impacted by sand. We monitor the driving marine conditions on the foreshore using a network of current meters and wave pressure sensors. Erosion of the cliff face across the whole bay is monitored at high-resolution using terrestrial laser scanning to examine the spatial distribution of abrasion and the influence of the ephemeral beach.

  13. 76 FR 1469 - Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2...

    Science.gov (United States)

    2011-01-10

    ... COMMISSION Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2... Cliffs Nuclear Power Plant, LLC, the licensee, for operation of the Calvert Cliffs Nuclear Power Plant..., Calvert Cliffs Nuclear Power Plant (NUREG-1437, Supplement 1), dated......

  14. A contrasting study: cliff and bank swallows

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of the project was to contrast as population of Cliff Swallows and a population of Bank Swallows. Both populations had nests located in a gravel pit near...

  15. 75 FR 66802 - Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2...

    Science.gov (United States)

    2010-10-29

    ... COMMISSION Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2... Regulatory Commission (the Commission) has granted the request of Calvert Cliffs Nuclear Power Plant, LLC... Operating License Nos. DPR-53 and DPR-69 for the Calvert Cliffs Nuclear Power Plant, Unit......

  16. 76 FR 4391 - Calvert Cliffs Nuclear Power Plant, LLC, Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2...

    Science.gov (United States)

    2011-01-25

    ... COMMISSION Calvert Cliffs Nuclear Power Plant, LLC, Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2; Exemption 1.0 Background Calvert Cliffs Nuclear Power Plant, LLC, the licensee, is the holder of Facility Operating License Nos. DPR-53 and DPR-69 which authorizes operation of the Calvert Cliffs Nuclear...

  17. 76 FR 39908 - Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2...

    Science.gov (United States)

    2011-07-07

    ... COMMISSION Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2.... DPR-53 and DPR-69, for the Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2 (CCNPP), respectively... (ISFSI), currently held by Calvert Cliffs Nuclear Power Plant, LLC as owner and licensed......

  18. Efficient circle detection by midpoint circle validation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shuai; CAO Junjie; LIU Xiuping

    2012-01-01

    Circular objects detection in digital images, a vital and recurring problem in image processing and computer vision, has many applications especially aiding vectorization of line drawing images, pupil and iris detection, circular traffic sign detection, and so on. In this paper, we lever Midpoint Circle Algorithm to speed up circle validation with sub-pixel precision. At the same time, we combine the least square method to improve the accuracy of circle detection. Experimental results from tests on synthetic and natural images validate that the proposed technique is efficiency regarding accuracy, speed and robustness.

  19. Activity cliffs and activity cliff generators based on chemotype-related activity landscapes.

    Science.gov (United States)

    Pérez-Villanueva, Jaime; Méndez-Lucio, Oscar; Soria-Arteche, Olivia; Medina-Franco, José L

    2015-11-01

    Activity cliffs have large impact in drug discovery; therefore, their detection and quantification are of major importance. This work introduces the metric activity cliff enrichment factor and expands the previously reported activity cliff generator concept by adding chemotype information to representations of the activity landscape. To exemplify these concepts, three molecular databases with multiple biological activities were characterized. Compounds in each database were grouped into chemotype classes. Then, pairwise comparisons of structure similarities and activity differences were calculated for each compound and used to construct chemotype-based structure-activity similarity (SAS) maps. Different landscape distributions among four major regions of the SAS maps were observed for different subsets of molecules grouped in chemotypes. Based on this observation, the activity cliff enrichment factor was calculated to numerically detect chemotypes enriched in activity cliffs. Several chemotype classes were detected having major proportion of activity cliffs than the entire database. In addition, some chemotype classes comprising compounds with smooth structure activity relationships (SAR) were detected. Finally, the activity cliff generator concept was applied to compounds grouped in chemotypes to extract valuable SAR information.

  20. 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...

  1. Small holding circles

    CERN Document Server

    Fruchard, Augustin

    2010-01-01

    A circle C holds a convex body K if C does not meet the interior of K and if there does not exist any euclidean displacement which moves C as far as desired from K, avoiding the interior of K. The purpose of this note is to explore how small can be a holding circle.

  2. 2012 Cliff Weiss Memorial Essay Contest Winners

    Science.gov (United States)

    Techniques: Connecting Education and Careers (J3), 2012

    2012-01-01

    This article presents the winners of the 2012 Cliff Weiss Memorial Essay Contest. They are Naim Owens from Washington, DC, and Colissa Menke from Warrensburg, Missouri. The 2012 essay topic is "How do you feel CTE prepares individuals, including yourself, for a future career?"

  3. 77 FR 47121 - Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Units 1 and 2...

    Science.gov (United States)

    2012-08-07

    ... COMMISSION Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Units 1 and 2; Exemption 1.0 Background Calvert Cliffs Nuclear Power Plant, LLC (the licensee) is the holder of Renewed..., ``Fatigue Management for Nuclear Power Plant Personnel,'' endorses the Nuclear Energy......

  4. Comprehensive knowledge base of two- and three-dimensional activity cliffs for medicinal and computational chemistry [v1; ref status: indexed, http://f1000r.es/5ir

    Directory of Open Access Journals (Sweden)

    Ye Hu

    2015-06-01

    Full Text Available Activity cliffs are formed by pairs or groups of structurally similar or analogous active compounds with large differences in potency. They can be defined in two or three dimensions by comparing graph-based molecular representations or compound binding modes, respectively. Through systematic analysis of publicly available compound activity data and ligand-target X-ray structures we have in a series of studies determined all currently available two- and three-dimensional activity cliffs (2D- and 3D-cliffs, respectively. Furthermore, we have systematically searched for 2D extensions of 3D-cliffs. Herein, we specify different categories of activity cliffs we have explored and introduce an open access data deposition in ZENODO (doi: 10.5281/zenodo.18490 that makes the entire knowledge base of current activity cliffs freely available in an organized form.

  5. Domain Discretization and Circle Packings

    DEFF Research Database (Denmark)

    Dias, Kealey

    A circle packing is a configuration of circles which are tangent with one another in a prescribed pattern determined by a combinatorial triangulation, where the configuration fills a planar domain or a two-dimensional surface. The vertices in the triangulation correspond to centers of circles......, and edges correspond to two circles (having centers corresponding to the endpoints of the edge) being tangent to each other. This circle packing creates a rigid structure having an underlying geometric triangulation, where the centers of circles again correspond to vertices in the triangulation......, and the edges are geodesic segments (Euclidean, hyperbolic, or spherical) connecting centers of circles that are tangent to each other. Three circles that are mutually tangent form a face of the triangulation. Since circle packing is closely related to triangulation, circle packing methods can be applied...

  6. Deriving mechanisms and thresholds for cliff retreat in soft-rock cliffs under changing climates: Rapidly retreating cliffs of the Suffolk coast, UK

    Science.gov (United States)

    Brooks, S. M.; Spencer, T.; Boreham, S.

    2012-06-01

    Understanding changing thresholds and mechanisms for retreat in soft rock cliffs is important under changing climates. This can be achieved through combining detailed field observation, long-term process and morphological monitoring and numerical modelling. The cliffs of the Suffolk coast, southern North Sea have exhibited long-term (1883-2010) recession rates of 3.5 m a- 1, rising to 4.7 m a- 1 in the period 1993-2010. Annual to biannual ground survey data, and the application of GIS techniques to digitised records of changing shoreline position from historic maps and aerial photography, reveal considerable decadal-scale variations in cliff recession, within which are nested inter-annual fluctuations in rates of retreat. Archival datasets on significant periods of onshore winds and their interaction with high water levels (including the incidence of storm surges) and rainstorm events are used to determine thresholds for cliff base erosion and its propagation upwards through the cliff profile. In addition, the ‘GEO-Slope' dynamic coupled hydrology-stability model is used to establish thresholds for cliff face failures driven by variations in rainfall inputs. Retreat mechanisms are complex, governed by cliff geology, both as a primary control on suction loss and through its interaction with basal marine conditions. The study allows a general model of cliff retreat for soft rock cliffs to be put forward, whereby a resistant basal platform is overlain by more erodible, weakly and moderately cemented sands and gravels. In this model, the varying balance between marine and terrestrial forcing factors are reflected in low ( 7 m a- 1) modes of cliff retreat.

  7. The Fiscal Cliff May be Overblown

    Institute of Scientific and Technical Information of China (English)

    Cyrus Sanati

    2012-01-01

    The markets have taken a beating since President Obama trounced Mitt Romney in Tuesday's election. The Dow is down 3% in the last two trading sessions and looks to be headed further south on Friday. While it is true that the markets historically take a dive after an incumbent president wins reelection, this latest drop has many on Wall Street on edge. Forget the weak corporate earnings, the freak hurricane that hit the East Coast and renewed troubles in Europe- no, this is all because of one thing: The looming fiscal cliff. Or that is what we are to believe.

  8. Going Round in Circles

    Science.gov (United States)

    Clausen-May, Tandi

    2006-01-01

    In this article, the author describes two Powerpoint presentations designed to help visual learners calculate the circumference and the area of a circle. In particular, the author describes how these presentations can be used to establish mental images that can help pupils to understand, and so recall, the principles that underlie the formulae for…

  9. Literature Circles in ELT

    Science.gov (United States)

    Shelton-Strong, Scott J.

    2012-01-01

    While the intrinsic value of reading extensively for L2 learners has rarely been questioned, practicalities of implementation and the existence of gains beyond lexical enrichment have generated discussion. This article outlines and explores the benefits which Literature Circles (LCs) offer to English language learning and attempts to identify…

  10. Differentiating through Literature Circles

    Science.gov (United States)

    Helgeson, John

    2017-01-01

    This article begins with an example of a typical middle-school experience with literature circles. Students read a common text and come prepared to share and discuss the text based on individual roles they are assigned. Teachers are using this practice to address the complexity levels of texts in order to help students develop the skills they need…

  11. The Activist Decade: Its Influence on Briar Cliff College.

    Science.gov (United States)

    Johnson, Patricia

    The influence of the "activist decade" (spanning the early 1960s through the early 1970s) on Briar Cliff College (Iowa), a small midwestern liberal arts college affiliated with the Catholic Church, is discussed. Forces such as racism, the Vietnam War, and student unrest elicited concern and activism at Briar Cliff College, although there…

  12. Predicting coastal cliff erosion using a Bayesian probabilistic model

    Science.gov (United States)

    Hapke, C.; Plant, N.

    2010-01-01

    Regional coastal cliff retreat is difficult to model due to the episodic nature of failures and the along-shore variability of retreat events. There is a growing demand, however, for predictive models that can be used to forecast areas vulnerable to coastal erosion hazards. Increasingly, probabilistic models are being employed that require data sets of high temporal density to define the joint probability density function that relates forcing variables (e.g. wave conditions) and initial conditions (e.g. cliff geometry) to erosion events. In this study we use a multi-parameter Bayesian network to investigate correlations between key variables that control and influence variations in cliff retreat processes. The network uses Bayesian statistical methods to estimate event probabilities using existing observations. Within this framework, we forecast the spatial distribution of cliff retreat along two stretches of cliffed coast in Southern California. The input parameters are the height and slope of the cliff, a descriptor of material strength based on the dominant cliff-forming lithology, and the long-term cliff erosion rate that represents prior behavior. The model is forced using predicted wave impact hours. Results demonstrate that the Bayesian approach is well-suited to the forward modeling of coastal cliff retreat, with the correct outcomes forecast in 70-90% of the modeled transects. The model also performs well in identifying specific locations of high cliff erosion, thus providing a foundation for hazard mapping. This approach can be employed to predict cliff erosion at time-scales ranging from storm events to the impacts of sea-level rise at the century-scale. ?? 2010.

  13. Layered circle packings

    Directory of Open Access Journals (Sweden)

    David Dennis

    2005-01-01

    Full Text Available Given a bounded sequence of integers {d0,d1,d2,…}, 6≤dn≤M, there is an associated abstract triangulation created by building up layers of vertices so that vertices on the nth layer have degree dn. This triangulation can be realized via a circle packing which fills either the Euclidean or the hyperbolic plane. We give necessary and sufficient conditions to determine the type of the packing given the defining sequence {dn}.

  14. A game magically circling

    DEFF Research Database (Denmark)

    Ejsing-Duun, Stine

    2011-01-01

    This chapter analyses the relationship between players, the game world, and the ordinary world in alternative reality games (ARGs) and location-based games (LBGs). These games use technology to create a game world in the everyday scene. The topic of this chapter is the concept of the 'magic circle......', which defines the relationship between play and the ordinary world, and how this concept relates to a new kind of game....

  15. Sea cliff erosion in the eastern part of the North Aegean coastline, Northern Greece.

    Science.gov (United States)

    Xeidakis, George S; Delimani, P K; Skias, S G

    2006-01-01

    The coastal zone is an area where many human activities are taking place. Erosion of the coast obstructs, in various ways, these activities creating occasionally serious socioeconomic and environmental problems. In this paper the coastal erosion problems encountered in the eastern Greek part of the North Aegean Sea Coast, a stretch of about 51 km long adjacent to the city of Alexandroupolis, are discussed. Given the observed type and location of erosion and other sea-action phenomena, the coast under study is divided in two parts/stretches. The western stretch, where the city of Alexandroupolis is presently extending, presents, mainly, cliff erosion problems and retreat of the coastline, very serious in some sections; whereas, the eastern stretch (to the east of the city) exhibits deposition and progression seawards due to the abundance of sediments supplied by Evros river delta. A classification of the coastline according to its relief, geologic material, erosion characteristics and rate, slope failure phenomena as well as the wave energy potential, is presented together with suggestions for case-appropriate mitigation and protection measures regarding the coastal erosion problems. The paper is focusing on the cliff erosion phenomena, since varying in height coastal cliffs made of soft rocks, cover the major part of the investigated coastline (western stretch).

  16. Erosion risk assessment of active coastal cliffs in temperate environments

    Science.gov (United States)

    Del Río, Laura; Gracia, F. Javier

    2009-11-01

    The potentially negative consequences resulting from cliff recession are a matter of serious concern in many coastal areas worldwide. The assessment of such processes has traditionally been performed by calculating average cliff recession rates and projecting them into the future, without taking into consideration the diverse factors affecting cliff dynamics and stability. In this work a new, practical method is presented to evaluate cliff erosion risk in temperate environments, by analysing the main factors responsible for both the physical and the socioeconomic aspects of erosion, representing cliff loss potential and damage potential, respectively. For this purpose an integration of 11 physical variables (such as cliff lithology, beach characteristics or rainfall regime) and 6 socioeconomic variables (such as land use type or population density) is proposed. These variables are weighted and combined into a Hazard Index and an Impact Index, which in turn are merged into a composite Risk Index where the resulting values are normalized and expressed as a percentage of the maximum theoretical risk. The method is tested and validated by using data about cliff retreat rates and mass movement processes in the coast of Cádiz province (SW Spain). The proposed approach allows the zoning of coastal cliffs according to the risk, hazard and/or impact levels, including the recognition of critical areas where specific intervention strategies should be adopted. The method presented in this work is deemed both practical and scientifically valid, without requiring extensive and detailed surveys of the area where it is to be applied. This way, it constitutes an easy to use, valuable tool for decision-making regarding land use planning and management strategies for active coastal cliffs.

  17. A quantitative analysis of rock cliff erosion environments

    Science.gov (United States)

    Lim, M.; Rosser, N.; Petley, D. N.; Norman, E. C.; Barlow, J.

    2009-12-01

    The spatial patterns and temporal sequencing of failures from coastal rock cliffs are complex and typically generate weak correlations with environmental variables such as tidal inundation, wave energy, wind and rain. Consequently, understanding of rock cliff behaviour, its response to predicted changes in environmental forcing and, more specifically, the interaction between marine and climatic factors in influencing failure processes has remained limited. This work presents the results from the first attempt to characterise and quantify the conditions on coastal cliffs that lead to accelerated rates of material detachment. The rate of change in an 80 m high section of coastal rock cliffs has been surveyed annually with high-resolution terrestrial laser scanning (TLS). The rockfall data have been analysed according to a simplified source geology that exhibit distinct magnitude-frequency distributions relating to the dominance of particular failure types. An integrated network of sensors and instrumentation designed to reflect the lithological control on failure has been installed to examine both the distinction between prevailing conditions and those affecting the local cliff environment and the physical response of different rock types to micro-climatic processes. The monitoring system records near-surface rock strain, temperature, moisture and micro-seismic displacement in addition to air temperature, humidity, radiation, precipitation, water-level and three-dimensional wind characteristics. A characteristic environmental signal, unique to the cliff face material, has been identified that differs substantially from that experienced by the surrounding area; suggesting that established methods of meteorological and tidal data collection are insufficient and inappropriate to represent erosive processes. The interaction between thermo- and hydro-dynamics of the cliff environment and the physical response of the rock highlights the composite environmental effects

  18. Circle of Form

    DEFF Research Database (Denmark)

    Jaeger, Thomas Arvid

    2012-01-01

    a common professional language like in mathematics, colour and music. The result is a weaker professionalism in the aesthetic competences compared to the professionalism and competences in other areas. A research project [1] on contrasts or opposites in form investigated the phenomenon in the fields...... by this model, and using the knowledge gathered from the other areas, especially perception psychology, it showed to be a possible way to organize contrasts in form, a system of 4 different opposites, geometric, organic, mass and structure: The Circle of Form....

  19. Recumbent Stone Circles

    Science.gov (United States)

    Ruggles, Clive L. N.

    During the 1970s and early 1980s, British archaeoastronomers were striving to bridge the interpretative gulf between the "megalithic observatories" of Alexander Thom and an archaeological mainstream that, generally speaking, was hostile to any mention of astronomy in relation to the megalithic monuments of Neolithic and Early Bronze Age Britain. The Scottish recumbent stone circles (RSCs) came to represent an example where sounder methodology could overcome many of the data selection issues that had beset earlier studies and, with due restraint, produce credible interpretations. Systematic studies of their orientations consistently concluded that the RSCs had a strong lunar connection, and it was widely envisaged that they were the setting for ceremonies associated with the appearance of the moon over the recumbent stone. Other evidence such as the presence of white quartz and the spatial distribution of cupmarks appeared to back up this conclusion. New archaeological investigations since 1999 have challenged and modified these conclusions, confirming in particular that the circles were built to enclose cairns rather than to demarcate open spaces. Yet the restricted pattern of orientations of these structures could only have been achieved by reference to the basic diurnal motions of the skies, and orientation in relation to simple observations of the midsummer moon remains the most likely reading of the alignment evidence taken as a whole. On the other hand, a consideration of the broader context, which includes the nearby Clava cairns, highlights instead the symbolic importance of the sun.

  20. [Willis and his circle].

    Science.gov (United States)

    van Gijn, Jan; Gijselhart, Joost P

    2012-01-01

    Thomas Willis (1621-1675) grew up in Wiltshire and studied medicine in Oxford, at a time when the city was besieged and then occupied by Parliamentarian troops. He started his career as a country doctor while concurrently taking part in informal gatherings with other scientists (William Petty, Christopher Wren and, later on, Robert Hooke, Richard Lower and Robert Boyle). They performed physical and chemical experiments and carried out a variety of tests on animals. After the restoration of the monarchy in 1660 Willis combined his practice with academic teaching. From then on he focused his studies on the structure and function of the brain, dissecting brains after removal from the skull and fixation in 'spirit of wine'. In his 'Cerebri anatome' of 1664, illustrated by Wren, he drew attention to the arterial circle at the base of the brain, including its physiological advantages. This arterial circle had been incompletely described by others in the past and fully, but only in writing, by Wepfer in 1658.

  1. Cliff swallow populations in the southern Askinuk Mountains, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — During breeding season, cliff swallows are widely distributed throughout Alaska and North America south to Mexico, and they are locally common in western and...

  2. Life strategies of bryophytes on loess cliffs in Vojvodina, Serbia

    Directory of Open Access Journals (Sweden)

    Sabovljević Marko S.

    2004-01-01

    Full Text Available The loess cliffs of Vojvodina present a special ecosystem type. The main plant components in these habitats are cryptogams (bryophytes and lichens. The biology and life strategies of bryophytes recorded on loess in Vojvodina are studied in the present work, whose results confirm a very special ecology in such habitats. Colonist species with xeropottioid characteristics are dominant among bryophytes. It is stressed that loess cliff habitats are especially important from the standpoint of conservation.

  3. The Arctic Circle Revisited

    CERN Document Server

    Colomo, F

    2007-01-01

    The problem of limit shapes in the six-vertex model with domain wall boundary conditions is addressed by considering a specially tailored bulk correlation function, the emptiness formation probability. A closed expression of this correlation function is given, both in terms of certain determinant and multiple integral, which allows for a systematic treatment of the limit shapes of the model for full range of values of vertex weights. Specifically, we show that for vertex weights corresponding to the free-fermion line on the phase diagram, the emptiness formation probability is related to a one-matrix model with a triple logarithmic singularity, or Triple Penner model. The saddle-point analysis of this model leads to the Arctic Circle Theorem, and its generalization to the Arctic Ellipses, known previously from domino tilings.

  4. A Less Conservative Circle Criterion

    OpenAIRE

    2008-01-01

    A weak form of the Circle Criterion for Lur'e systems is stated. The result allows prove global boundedness of all system solutions. Moreover such a result can be employed to enlarge the set of nonlinearities for which the standard Circle Criterion can guarantee absolute stability.

  5. Recent progress in understanding activity cliffs and their utility in medicinal chemistry.

    Science.gov (United States)

    Stumpfe, Dagmar; Hu, Ye; Dimova, Dilyana; Bajorath, Jürgen

    2014-01-09

    The activity cliff concept is of high relevance for medicinal chemistry. Recent studies are discussed that have further refined our understanding of activity cliffs and suggested different ways of exploiting activity cliff information. These include alternative approaches to define and classify activity cliffs in two and three dimensions, data mining investigations to systematically detect all possible activity cliffs, the introduction of computational methods to predict activity cliffs, and studies designed to explore activity cliff progression in medicinal chemistry. The discussion of these studies is complemented with new findings revealing the frequency of activity cliff formation when different molecular representations are used and the distribution of activity cliffs across different targets. Taken together, the results have a number of implications for the practice of medicinal chemistry.

  6. A regional approach for modeling cliff retreat rate: The Makhteshim Country, Israel

    Science.gov (United States)

    Finzi, Yaron; Harlev, Noam

    2016-10-01

    Cliff retreat rate significantly affect the evolution of landforms and cliff stability. Cliff retreat studies also provide intriguing clues regarding past geomorphic conditions and environmental changes. We hereby present a model to calculate cliff retreat rate based on spatial data of cliff structure and morphology. The model is applied to numerous cliffs in the arid Makhteshim Country, Israel, and results are calibrated using published rates of two local cliffs. The calculated retreat rates confirm previous assertions that the crater cliffs are receding very slowly, but reveal that the rates vary significantly along the cliffs (1-18 cm ky- 1). Results also provide first estimates of retreat rates of other major cliffs in the region including fast retreat rates at the Sede Zin cliff (300-600 cm ky- 1). The proposed model provides a robust analysis to account for local cliff-talus morphology and yields rate estimates representative of current conditions rather than a long-term (geologic) average rate. Results presented constitute important new insights into regional geomorphic processes and on the stability of specific cliff sections within the study area.

  7. Power laws statistics of cliff failures, scaling and percolation

    CERN Document Server

    Baldassarri, Andrea

    2014-01-01

    The size of large cliff failures may be described in several ways, for instance considering the horizontal eroded area at the cliff top and the maximum local retreat of the coastline. Field studies suggest that, for large failures, the frequencies of these two quantities decrease as power laws of the respective magnitudes, defining two different decay exponents. Moreover, the horizontal area increases as a power law of the maximum local retreat, identifying a third exponent. Such observation suggests that the geometry of cliff failures are statistically similar for different magnitudes. Power laws are familiar in the physics of critical systems. The corresponding exponents satisfy precise relations and are proven to be universal features, common to very different systems. Following the approach typical of statistical physics, we propose a "scaling hypothesis" resulting in a relation between the three above exponents: there is a precise, mathematical relation between the distributions of magnitudes of erosion ...

  8. CliffsNotes Writing Grammar, Usage, and Style Quick Review

    CERN Document Server

    Eggenschwiler, Jean; Reinhardt, Claudia L W

    2011-01-01

    Inside the Book: Nouns - Verbs - Pronouns - Modifiers - Connecting Words and Phrases - Clauses, Phrases, and Sentences - Common Sentence Errors - Periods, Question Marks, and Exclamation Marks - Commas, Semicolons, and Colons - Dashes, Parentheses, and Quotation Marks - Idioms, Clichés, Jargon, and Wordiness - How to Begin a Writing Assignment - How to Research and Organize Your Writing - Revising and Editing - Review Questions - Resource Center - Glossary - Frequently Confused Words Why CliffsNotes? Go with the name you know and trust - Get the information you need-fast! CliffsNotes Quick Rev

  9. Partial covering of a circle by equal circles. Part II: The case of 5 circles

    Directory of Open Access Journals (Sweden)

    Zsolt Gáspár

    2014-05-01

    Full Text Available How must n equal circles of given radius r be placed so that they cover as great a part of the area of the unit circle as possible? In this Part II of a two-part paper, a conjectured solution of this problem for n = 5 is given for r varying from the maximum packing radius to the minimum covering radius. Results are obtained by applying a mechanical model described in Part I. A generalized tensegrity structure is associated with a maximum area configuration of the 5 circles, and by using catastrophe theory, it is pointed out that the ''equilibrium paths'' have bifurcations, that is, at certain values of r, the type of the tensegrity structure and so the type of the circle configuration changes.

  10. Crawling-Onset Age Predicts Visual Cliff Avoidance in Infants.

    Science.gov (United States)

    Richards, John E.; Rader, Nancy

    1981-01-01

    Two experiments tested the effects of crawling-onset age, amount of crawling experience, and testing age on avoidance of the deep side of a visual cliff apparatus by human infants. Crawling-onset age disciminated between infants because crawling during the tactile phase interferes with later visual control of locomotion. (Author/RD)

  11. A physically based 3-D model of ice cliff evolution over debris-covered glaciers

    Science.gov (United States)

    Buri, Pascal; Miles, Evan S.; Steiner, Jakob F.; Immerzeel, Walter W.; Wagnon, Patrick; Pellicciotti, Francesca

    2016-12-01

    We use high-resolution digital elevation models (DEMs) from unmanned aerial vehicle (UAV) surveys to document the evolution of four ice cliffs on the debris-covered tongue of Lirung Glacier, Nepal, over one ablation season. Observations show that out of four cliffs, three different patterns of evolution emerge: (i) reclining cliffs that flatten during the ablation season; (ii) stable cliffs that maintain a self-similar geometry; and (iii) growing cliffs, expanding laterally. We use the insights from this unique data set to develop a 3-D model of cliff backwasting and evolution that is validated against observations and an independent data set of volume losses. The model includes ablation at the cliff surface driven by energy exchange with the atmosphere, reburial of cliff cells by surrounding debris, and the effect of adjacent ponds. The cliff geometry is updated monthly to account for the modifications induced by each of those processes. Model results indicate that a major factor affecting the survival of steep cliffs is the coupling with ponded water at its base, which prevents progressive flattening and possible disappearance of a cliff. The radial growth observed at one cliff is explained by higher receipts of longwave and shortwave radiation, calculated taking into account atmospheric fluxes, shading, and the emission of longwave radiation from debris surfaces. The model is a clear step forward compared to existing static approaches that calculate atmospheric melt over an invariant cliff geometry and can be used for long-term simulations of cliff evolution and to test existing hypotheses about cliffs' survival.

  12. The Voronoi diagram of circles made easy

    DEFF Research Database (Denmark)

    Anton, François; Mioc, Darka; Gold, Christopher

    2007-01-01

    Proximity queries among circles could be effectively answered if the Delaunay graph for sets of circles could be computed in an efficient and exact way. In this paper, we first show a necessary and sufficient condition of connectivity of the Voronoi diagram of circles. Then, we show how the Delau......Proximity queries among circles could be effectively answered if the Delaunay graph for sets of circles could be computed in an efficient and exact way. In this paper, we first show a necessary and sufficient condition of connectivity of the Voronoi diagram of circles. Then, we show how...

  13. Locating a minisum circle in the plane

    DEFF Research Database (Denmark)

    Brimberg, Jack; Juel, Henrik; Schöbel, Anita

    2009-01-01

    We consider the problem of locating a circle with respect to existing facilities in the plane such that the sum of weighted distances between the circle and the facilities is minimized, i.e., we approximate a set of given points by a circle regarding the sum of weighted distances. If the radius...... of the circle is a variable we show that there always exists an optimal circle passing through two of the existing facilities. For the case of a fixed radius we provide characterizations of optimal circles in special cases. Solution procedures are suggested....

  14. Topological conjugacy of circle diffeomorphisms

    OpenAIRE

    1995-01-01

    The classical criterion for a circle diffeomorphism to be topologically conjugate to an irrational rigid rotation was given by A. Denjoy. In 1985, one of us (Sullivan) gave a new criterion. There is an example satisfying Denjoy's bounded variation condition rather than Sullivan's Zygmund condition and vice versa. This paper will give the third criterion which is implied by either of the above criteria.

  15. On a Family of Circles

    Science.gov (United States)

    Feeman, Timothy G.

    2011-01-01

    We generalize a standard example from precalculus and calculus texts to give a simple description in polar coordinates of any circle that passes through the origin. We discuss an occurrence of this formula in the context of medical imaging. (Contains 1 figure.)

  16. The Circle Approach to Trigonometry

    Science.gov (United States)

    Moore, Kevin c.; LaForest, Kevin R.

    2014-01-01

    How do students think about an angle measure of ninety degrees? How do they think about ratios and values on the unit circle? How might angle measure be used to connect right-triangle trigonometry and circular functions? And why might asking these questions be important when introducing trigonometric functions to students? When teaching…

  17. Devonian lacustrine shore zone architecture: giving perspective to cliff exposures with ground penetrating radar

    DEFF Research Database (Denmark)

    Andrews, Steven D.; Moreau, Julien; Archer, Stuart

    Lake margin sedimentary systems have been the subject of only limited study. The orbitally controlled cyclic lacustrine successions of the Middle Old Red Sandstone of Northern Scotland contains repeated developments of shore zone sandstones and thus provides an ideal location for the study...... of these units. The cycles are on average 16-m-thick and comprise deep lake, perennial lake and playa facies. The shore zone facies reaches 2 to 3.5 m in thickness and is found within the playa facies. On the exposures, the shore zone facies seems to be aggrading with most of the layers apparently subhorizontal....... However, this depositional environment ought to be relatively dynamic with sand body migration and erosions. In addition, along the coastal cliffs, the exposures are mainly on the same strike direction. To better understand the peculiar shore zone system, we carried out very high resolution sedimentary...

  18. Sea cliff instability susceptibility at regional scale: A statistically based assessment in southern Algarve, Portugal.

    Science.gov (United States)

    Marques, F.; Matildes, R.; Redweik, P.

    2012-04-01

    Mass movements are the dominant process of sea cliff evolution, being a considerable source of natural hazard and a significant constrain for human activities in coastal areas. Related hazards include cliff top retreat, with implications on planning and land management, and unstable soil or rock movements at the cliffs face and toe, with implications mainly on beach users and support structures. To assess the spatial component of sea cliff hazard assessment with implications on planning, i.e. the susceptibility of a given cliff section to be affected by instabilities causing retreat of the cliff top, a statistically based study was carried out along the top of the sea cliffs of Burgau-Lagos coastal section (Southwest Algarve, Portugal). The study was based on bivariate and multi-variate statistics applied to a set of predisposing factors, mainly related with geology and geomorphology, which were correlated with an inventory of past cliff failures. The multi-temporal inventory of past cliff failures was produced using aerial digital photogrammetric methods, which included special procedures to enable the extraction of accurate data from old aerial photos, and validated by systematic stereo photo interpretation, helped by oblique aerial photos and field surveys. This study identified 137 cliff failures occurred between 1947 and 2007 along the 13 km long cliffs, causing the loss of 10,234 m2 of horizontal area at the cliffs top. The cliff failures correspond to planar slides (58%) mainly in Cretaceous alternating limestone and marls, toppling failures (17%) mainly in Miocene calcarenites, slumps (15%) in Plio-pleistocene silty sands that infill the karst in the Miocene rocks, and the remaining 10% correspond to complex movements, rockfalls and not determined cases. The space distribution of cliff failures is quite irregular but enables the objective separation of sub sections with homogeneous retreat behavior, for which were computed mean retreat rates between 5x10-3m

  19. Multi-temporal retreat rates along the eastern Mediterranean coastal cliff

    Science.gov (United States)

    Katz, O.; Mushkin, A.

    2012-12-01

    The Israeli coastal cliff extends about 50 km along the eastern Mediterranean shores. The cliff is comprised of late Quaternary eolianites and paleosols and reaches heights of up to 50 meters. In places, time-averaged inland cliff-top retreat rates of up to a few tens of centimeters per year have been measured usually by comparing aerial photos from the last decades. Commonly, these locally constrained retreat rates have been: 1) extrapolated as representative of the entire cliff length, and 2) adopted by hazard-mitigation and planning authorities. Here, we re-evaluate the current understanding of coastal-retreat patterns and rates along Israel's Mediterranean cliff line using a suite of field observations, aerial photography and recently obtained airborne and ground based high resolution LiDAR measurement of cliff morphologies. First, we constrain the decadal-scale retreat rates along the coastal-cliff by comparing the cliff-top location in 1945 and 2004 using aerial photos. We find a statistically significant spatial correlation between: 1) calculated low retreat rates (less than 0.1 m/yr) and field-based criteria indicating overall stability: slope angle of 45 deg. and talus cover along the lower part of the cliff and developed vegetation cover, and 2) high retreat rates and field criteria indicating recent instability: fresh landslide scars and 'hanging' valleys, which provides independent support for the calculated retreat rates. Calculated 60 years average cliff-top retreat rates of less than 0.1, 0.2 and 0.3 m/yr along 58%, 77% and 85% of the cliff length, respectively, reveal that extended stretches of the cliff line did not experience detectable retreat in the past 60 years, thus implying relative stability of 50% of Israel's costal cliffs during this time period. Second, we constrain the annual retreat rates using repeat high-resolution ground based LiDAR surveys before and after an extreme winter storm that occurred in Dec. 2010. Locally, storm induced

  20. Aerial Photogrammetric Analysis of a Scree Slope and Cliff

    Science.gov (United States)

    Saunders, Greg; Galland, Olivier; Mair, Karen

    2014-05-01

    Mapping the physical features of landslide tracks provides information about factors controlling landslide movement. The increasing availability of unmanned aerial vehicles (UAV) provides the opportunity to efficiently and cost effectively map terrain. The main goal of this field study is to create a streamlined work-flow from acquisition to interpretation for the photogrammetric analysis of landslide tracks. Here an open source software package MicMac is used for ortho-image and point-cloud creation. A series of two flights were conducted over a scree (rockfall) slope in Kolsas, Norway. The slope runs roughly 500 m north-south with a maximum width of 60 m. A cliff to the west is the source area for the scree. The cliff consists of conglomerate, basalt, and porphyry from bottom to top respectively. The grain size of boulders in the scree slope apparently varies due to lateral differences in the cliff composition. The flights were completed under cloud cover and consisted of multiple lengthwise passes over the scree field. There was a minimum of 75% overlap between images. During the first flight the altitude was roughly 100 m, the camera was positioned normal to the scree (60 degrees from horizontal), and the resolution was 2.7 cm per pixel. The second flight had an altitude of 200 m, the camera orientation was 30 degrees from horizontal, and the resolution was 4.0 cm per pixel. Using the Micmac engine, Ortho-photos and Digital Elevation Models (DEM) were created for both the scree and the cliff. This data will allow for analysis of grain-size, surface roughness, grain-shape, fracture plane orientation, as well as geological mapping. Further work will focus the quantitative assessment of the significance different camera altitudes and angles have on the results. The work-flow used in this study provides a repeatable method for aerial photogrammetric surveys of scree slopes.

  1. Ancient "Red Cliff" battlefield: a historical-geographic study

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiugui

    2006-01-01

    The famous battle of Chibi,or "battle of Red Cliff",took place in 208 CE,the 13th year of the Jian'an period of the Eastern Han dynasty.This paper holds that the whole battle consisted of three inseparable stages,namely the initial clash at Chibi,the chase battle to Wulin,and Cao Cao's disorganized escape along Huarong Road.The Red Cliff battlefield thus extended across a distance of more than 300 li (150km).Even if the Chibi where the initial military engagement took place (that is,Chiji Hill,southwest of Wuchang in modern Wuhan City) has already disappeared,it should be restored to its proper historical position.The chase battle along the Yangzi River came to an end at Wulin,across the river is Chibi Hill in today's Chibi City.Although this Chibi is not the Chibi where the initial combat took place,it nonetheless forms an integral part of the ancient Chibi battlefield as a whole.The Huarong Road along which Cao Cao escaped runs through the middle of today's Jianghan Plain.Finally,the text aims to show that Chibi (Red Nose)1 Hill in modern Huangzhou City has nothing to do with the Chibi of the "battle of Red Cliff."

  2. An empirical conceptual gully evolution model for channelled sea cliffs

    Science.gov (United States)

    Leyland, Julian; Darby, Stephen E.

    2008-12-01

    Incised coastal channels are a specific form of incised channel that are found in locations where stream channels flowing to cliffed coasts have the excess energy required to cut down through the cliff to reach the outlet water body. The southern coast of the Isle of Wight, southern England, comprises soft cliffs that vary in height between 15 and 100 m and which are retreating at rates ≤ 1.5 m a - 1 , due to a combination of wave erosion and landslides. In several locations, river channels have cut through the cliffs to create deeply (≤ 45 m) incised gullies, known locally as 'Chines'. The Chines are unusual in that their formation is associated with dynamic shoreline encroachment during a period of rising sea-level, whereas existing models of incised channel evolution emphasise the significance of base level lowering. This paper develops a conceptual model of Chine evolution by applying space for time substitution methods using empirical data gathered from Chine channel surveys and remotely sensed data. The model identifies a sequence of evolutionary stages, which are classified based on a suite of morphometric indices and associated processes. The extent to which individual Chines are in a state of growth or decay is estimated by determining the relative rates of shoreline retreat and knickpoint recession, the former via analysis of historical aerial images and the latter through the use of a stream power erosion model.

  3. Locating a circle on a sphere

    DEFF Research Database (Denmark)

    Brimberg, Jack; Juel, Henrik; Schöbel, Anita

    2003-01-01

    We consider the problem of locating a spherical circle with respect to existing facilities on a sphere, such that the sum of weighted distances between the circle and the facilities is minimized, or such that the maximum weighted distance is minimized. The problem properties are analyzed, and we...... give solution procedures. When the circle to be located is restricted to be a great circle, some simplifications are possible....

  4. Ice cliff dynamics in the Everest region of the Central Himalaya

    Science.gov (United States)

    Scott Watson, C.; Quincey, Duncan J.; Carrivick, Jonathan L.; Smith, Mark W.

    2017-02-01

    The importance of ice cliffs for glacier-scale ablation on debris-covered glaciers is now widely recognised. However, a paucity of data exists to describe the spatio-temporal distribution of ice cliffs. In this study we analysed the position and geometry of 8229 ice cliffs and 5582 supraglacial ponds on 14 glaciers in the Everest region between 2000 and 2015. We observed notable ice cliff and pond spatial coincidence. On average across our study glaciers, 77% of supraglacial pond area was associated with an adjacent ice cliff, and 49% of ice cliffs featured an adjacent supraglacial pond. The spatial density of ice cliffs was not directly related to glacier velocity, but did peak within zones of active ice. Furthermore, we found that ice cliff density was glacier-specific, temporally variable, and was positively correlated with surface lowering and decreasing debris thickness for individual glaciers. Ice cliffs predominantly had a north-facing (commonly north-westerly) aspect, which was independent of glacier flow direction, thereby signifying a strong solar radiation control on cliff evolution. Independent field observations indicated that cliff morphology was related to aspect, local debris thickness, and presence of a supraglacial pond, and highlighted the importance of surface runnel formation, which acts as a preferential pathway for meltwater and debris fluxes. Overall, by coupling remote sensing and in-situ observations it has been possible to capture local and glacier-scale ice cliff dynamics across 14 glaciers, which is necessary if explicit parameterisation of ice cliffs in dynamic glacier models is to be achieved.

  5. Yarning Circles in the Literacy Classroom

    Science.gov (United States)

    Mills, Kathy A.; Sunderland, Naomi; Davis-Warra, John

    2014-01-01

    This article explains how the speaking and listening practice of yarning circles can be used in the literacy classroom. The article opens with an account of a live enactment of yarning circles with elementary students in a mainstream classroom in Australia. It explains the purpose and origin of yarning circles in Indigenous communities, and…

  6. Science Literacy Circles: Big Ideas about Science

    Science.gov (United States)

    Devick-Fry, Jane; LeSage, Teresa

    2010-01-01

    Science literacy circles incorporate the organization of both science notebooks and literature circles to help K-8 students internalize big ideas about science. Using science literacy circles gives students opportunities to engage in critical thinking as they inductively develop understanding about science concepts. (Contains 1 table and 7…

  7. Characteristics and hydrodynamic interpretation of storm-emplaced cliff-top boulder ridges on Inishmore, Aran Islands, Ireland

    Science.gov (United States)

    Zentner, D. B.; Cox, R.

    2008-12-01

    Dramatic boulder ridges are widespread on cliff-top platforms of Ireland's Aran Islands, emplaced by storm waves at elevations up to 50 m. In places the ridges have overridden 19th-century field walls, and recent movement of large blocks is attested to by modern debris--including nylon ropes, aerosol cans, and plastic bottles--pinned under megaclasts of up to 40 tons. Large waves are common off Ireland's west coast, as revealed by the short records available from recently-deployed buoy systems. The Irish Marine Weather Buoy Network measured wave heights (≥10 m on 29 days between 2001 and 2007, and waves up to 18 m high were recorded in December 2007. Blocks quarried by such waves from the upper few m of the cliffs are transported inland to form semi-continuous boulder ridges parallel to the coastline, which therefore offer a record of hydrodynamics during high-energy wave events. On Inishmore, boulder ridges occur at elevations up to 28 m, separated from the cliff edge by wave-scoured platforms 1-70 m wide. The ridges consist of imbricated, highly angular slabs, ranging from small gravel to 5 m megaclasts. They are 1-4.6 m high, 10-48 m wide (Ripple Index 5-17), and strongly asymmetric, with steep narrow stoss faces (10- 35°), and long gentle lee slopes (<14°). With increasing cliff height, ridges are smaller, narrower, made of smaller blocks, and sit closer to the edge; but ridges 20 m wide and 2 m high, with half-ton clasts, occur as high as 28 m OD. The deposits are moderately to well sorted, predominantly unimodal, and fine skewed. Median clast size ranges from fine to coarse boulders (0.5-2 m). Clasts show strong seaward imbrication on both stoss and lee sides (dipping up to 85° with average 25°). "Blowout" features on the lee sides, with boulders imbricated radially around central depressions of 1-2 m diameter, suggest turbulent flow separation, as does the common occurrence of 1-3 smaller secondary ridges landward of the main crest. The uniformity of

  8. Cosmic crystallography in a circle

    CERN Document Server

    Teixeira, A F F

    2000-01-01

    In a circle (an $S^1$) with circumference 1 assume $m$ objects distributed pseudo-randomly. In the universal covering $R^1$ assume the objects replicated accordingly, and take an interval $L>1$. In this interval, make the normalized histogram of the pair separations which are not an integer. The theoretical (expected) such histogram is obtained in this report, as well as its difference to a similar histogram for non-replicated objects. The whole study is of interest for the cosmic crystallography.

  9. Exploring the cliff retreat response to base level change using SFM photogrammetry and cosmogenic 36Cl, Coal Cliffs, Utah, USA

    Science.gov (United States)

    Sheehan, C.; Ward, D.

    2015-12-01

    The retreat of cliffbands is an important erosional process within the relatively undeformed sedimentary layers of the Colorado Plateau. Many iconic cliff landforms, including those of Monument Valley and Grand Canyon, are maintained by the interaction of these different rock types. A several kilometer thickness of incised sandstone and shale formations allow this region to act as a natural laboratory for studying the effects of variable lithologies on landscape evolution. Cliffband morphology and retreat on the plateau are controlled by several factors that may vary over time and space, including lithology, rate and distribution of rockfall debris, bedrock structure, baselevel, and climate. The relative importance of each factor in setting rates of cliff retreat are not entirely clear. Because regional headwaters are commonly sourced at cliff bases, these landforms are often the final and slowest areas to respond to baselevel changes, allowing rockfall and other local stochastic processes to overwhelm the erosional response to a baselevel forcing. The roles of these processes are difficult to assess because very few measurements of retreat rates over geomorphic timescales (103-106 years) have been produced, and thus changes in cliffband position through time have only been constrained by inferences made from the regional erosional history. Here, we control for climate and rock type by focusing on a continuous, 40-kilometer section of the lithologically consistent Coal Cliffs in Emery County, Utah. This area presents several natural experiments illustrating cliffband response to different forcings, including relict surfaces reflecting a baselevel change, drainage divides across which the adjustment to base level change may be asynchronous, a zone wherein the caprock layer has been removed by backscarp erosion, and a generally continuous gradient in cliff height from 50 to >200 meters along the cliffline. We employ terrestrial Cl36 exposure dating on terraces, talus

  10. Human impact on the vegetation of limestone cliffs in the northern Swiss Jura mountains

    OpenAIRE

    Müller, Stefan

    2006-01-01

    Cliffs provide unique habitats for many specialised organisms, including chamaephytes and slowly growing trees. Drought, high temperature amplitude, scarcity of nutrients and high insolation are general characteristics of exposed limestone cliff faces. The vegetation of limestone cliffs in the Swiss Jura mountains consists of plants of arctic-alpine, continental and Mediterranean origin. Several populations exhibit relicts from post- or interglacial warm or cold climatic per...

  11. On a conjecture concerning helly circle graphs

    Directory of Open Access Journals (Sweden)

    Durán Guillermo

    2003-01-01

    Full Text Available We say that G is an e-circle graph if there is a bijection between its vertices and straight lines on the cartesian plane such that two vertices are adjacent in G if and only if the corresponding lines intersect inside the circle of radius one. This definition suggests a method for deciding whether a given graph G is an e-circle graph, by constructing a convenient system S of equations and inequations which represents the structure of G, in such a way that G is an e-circle graph if and only if S has a solution. In fact, e-circle graphs are exactly the circle graphs (intersection graphs of chords in a circle, and thus this method provides an analytic way for recognizing circle graphs. A graph G is a Helly circle graph if G is a circle graph and there exists a model of G by chords such that every three pairwise intersecting chords intersect at the same point. A conjecture by Durán (2000 states that G is a Helly circle graph if and only if G is a circle graph and contains no induced diamonds (a diamond is a graph formed by four vertices and five edges. Many unsuccessful efforts - mainly based on combinatorial and geometrical approaches - have been done in order to validate this conjecture. In this work, we utilize the ideas behind the definition of e-circle graphs and restate this conjecture in terms of an equivalence between two systems of equations and inequations, providing a new, analytic tool to deal with it.

  12. Coherent states on the circle

    CERN Document Server

    Chadzitaskos, G; Tolar, J

    2011-01-01

    We present a possible construction of coherent states on the unit circle as configuration space. In our approach the phase space is the product Z x S^1. Because of the duality of canonical coordinates and momenta, i.e. the angular variable and the integers, this formulation can also be interpreted as coherent states over an infinite periodic chain. For the construction we use the analogy with our quantization over a finite periodic chain where the phase space was Z_M x Z_M. Properties of the coherent states constructed in this way are studied and the coherent states are shown to satisfy the resolution of unity.

  13. Molecular scaffolds with high propensity to form multi-target activity cliffs.

    Science.gov (United States)

    Hu, Ye; Bajorath, Jürgen

    2010-04-26

    In target-dependent activity landscapes of compound series, cliffs are formed by pairs of molecules that are structurally analogous but display significant differences in potency. The detection and analysis of such activity cliffs is a major task in structure-activity relationship analysis and compound optimization. In analogy to activity cliffs, selectivity cliffs can be defined that are formed by structural analogs having significantly different potencies against two targets. The formation of activity cliffs by analogs is generally a consequence of different R-group patterns; e.g., a specific substitution of a given scaffold might increase and another substitution decrease potency. Therefore, activity (or selectivity) cliffs are typically analyzed for a given scaffold representing an analog series, and it has thus far not been explored whether certain scaffolds might display a general tendency to yield compounds forming activity cliffs against different targets. We have exhaustively analyzed scaffolds and associated compound activity data in the ChemblDB and BindingDB databases in order to compare the availability of target-selective scaffolds in these databases and determine whether multi-target activity and multi-target selectivity cliff scaffolds exist. Perhaps unexpectedly, we have identified 143 scaffolds that are represented by multiple compounds and form activity or selectivity cliffs against different targets. These scaffolds have varying chemical complexities and are in part promiscuous binders (i.e., compounds containing these scaffolds bind to distantly related or unrelated targets). However, analogs derived from these scaffolds form steep activity cliffs against different targets. A catalog of scaffolds with high propensity to form activity or selectivity cliffs against multiple targets is provided to help identify potentially promiscuous candidate scaffolds during compound optimization efforts.

  14. The impact of solar radiation on vertical ice cliff recession on Kilimanjaro

    Science.gov (United States)

    Winkler, M.; Cullen, N.; Kaser, G.; Mölg, T.; Pfeffer, T.

    2009-04-01

    The glaciers on the summit plateau of Mount Kilimanjaro (5700m a.s.l., 3°04'S, 37°21'E) are characterized by nearly vertical ice cliffs at their margins. Recent studies have shown that glacier retreat on Africa's highest peak is closely linked to the recession of these cliffs. More than one year of distance measurements between an automatic weather station close to a south-facing cliff and the cliff itself reveal a strong linkage of the recession pattern and the annual cycle of solar radiation. As the cliff is not hit by direct shortwave radiation from March to October, not enough energy is provided to raise the cliff's surface temperature to 0°C and make melting possible. Only sublimation occurs and the point measurements indicate recession rates at the order of 0.5cm/month. From November to February - if cloud cover allows - the cliff is hit by direct shortwave radiation all day and its surface temperature can reach the melting point during some hours of the day. Melting occurs, although air temperature is always below freezing point, and the cliff retreats 20-30 times faster, because melting is much more energy-efficient than sublimation. A solar radiation model, using data of a free-standing automatic weather station, is run to find out why the majority of the cliffs is exposed either to the north or to the south, and to extrapolate the point measurements to the whole ice cliff. In addition, the impact of small scale differences in slope and aspect on the cliff recession is investigated using the radiation model. A multi-temporal photogrammetrical survey is carried out to quantify small scale recession differences in order to validate the solar radiation model results.

  15. Nature of short-period microtremors on the cliff-like ground. 3; Gakechi kinbo no tanshuki bido . 3

    Energy Technology Data Exchange (ETDEWEB)

    Maiguma, T.; Matsuzawa, H. [Saitama University, Saitama (Japan). Faculty of Engineering

    1996-05-01

    Vibration characteristics were investigated of the ground in the vicinity of a cliff-like sharp slope. Short-period microtremors were observed in the vicinity of an artificially made cliff-like test ground, height 8m and inclination 90{degree}, and a natural cliff, height approximately 9m and inclination approximately 35{degree}. The artificial cliff was reinforced by a virtually vertical retaining wall of concrete, and the ground was prepared for testing with a belt approximately 20m wide and 50m long along the cliff face. All the vibration components were simultaneously measured at measuring spots that were located 5-40m apart from the cliff end and orientated perpendicular to the cliff face. It was then found that in case of artificial cliff there is a conspicuous 3.1Hz prevalent ground vibration in the component squarely meeting the cliff face, that the prevalent ground vibration is not particularly great near the cliff end because the retaining wall and the ground are artificially prepared, that there is no influence of the cliff-like ground in the ground vibration parallel to or vertical along the cliff face, and that in case of natural ground there are no vibration characteristic proper to a cliff-like ground in any of the vibration components. 3 refs., 7 figs.

  16. The Glass Cliff: An Examination of the Female Superintendency in South Carolina

    Science.gov (United States)

    Bowles, Blanche Boyd

    2013-01-01

    South Carolina public school districts are confronted with a series of difficult circumstances and rely more on female superintendents than the national average. The investigation of female South Carolina superintendents was guided by the glass cliff conceptual framework. The glass cliff represents situations where females are promoted over males…

  17. X Marks the Plot: Can Cliffs Notes Help Students Find Literary Gold?

    Science.gov (United States)

    Lilla, Rick

    1998-01-01

    Examines Villanova University's decision to stop selling Cliffs Notes in its bookstore and attitudes toward Cliffs Notes, highlighting honest work, shortcuts, serious research, critical thinking, and original thinking. Provides the following advice for librarians: avoid being parental; avoid unexamined judgments; and avoid undervaluing Cliffs…

  18. Getting on top of the glass cliff : Reviewing a decade of evidence, explanations, and impact

    NARCIS (Netherlands)

    Ryan, Michelle K.; Haslam, S. Alexander; Morgenroth, Thekla; Rink, Floor; Stoker, Janka; Peters, Kim

    2016-01-01

    The glass cliff refers to the tendency for women to be more likely than men to be appointed to leadership positions that are risky and precarious. This paper reviews the first decade of research into the phenomenon and has three key aims: (a) to summarize and integrate evidence of the glass cliff, (

  19. Locating a circle on a sphere

    DEFF Research Database (Denmark)

    Brimberg, Jack; Juel, Henrik; Schöbel, Anita

    2007-01-01

    We consider the problem of locating a spherical circle with respect to existing facilities on a sphere, such that the sum of distances between the circle and the facilities is minimized or such that the maximum distance is minimized. The problem properties are analyzed, and we give solution...... procedures. When the circle to be located is restricted to be a great circle, some simplifications are possible. The models may be used in preliminary studies on the location of large linear facilities on the earth's surface, such as superhighways, pipelines, and transmission lines, or in totally different...

  20. 78 FR 49292 - Northshore Mining Company, a Subsidiary of Cliffs Natural Resources, Including On-Site Leased...

    Science.gov (United States)

    2013-08-13

    ... Employment and Training Administration Northshore Mining Company, a Subsidiary of Cliffs Natural Resources..., Minnesota; Northshore Mining Company, a Subsidiary of Cliffs Natural Resources, Including On- Site Leased... Miming Company, a subsidiary of Cliffs Natural Resources, including on-site leased workers from...

  1. 77 FR 10784 - Calvert Cliffs Nuclear Power Plant, LLC; Notice of Withdrawal of Application for Amendment to...

    Science.gov (United States)

    2012-02-23

    ... COMMISSION Calvert Cliffs Nuclear Power Plant, LLC; Notice of Withdrawal of Application for Amendment to... of Calvert Cliffs Nuclear Power Plant, LLC, the licensee, to withdraw its application dated October... the Calvert Cliffs Nuclear Plant, Units 1 and 2, respectively, located in Calvert County,...

  2. Mobile Laser Scanning along Dieppe coastal cliffs: reliability of the acquired point clouds applied to rockfall assessments

    Science.gov (United States)

    Michoud, Clément; Carrea, Dario; Augereau, Emmanuel; Cancouët, Romain; Costa, Stéphane; Davidson, Robert; Delacourt, Chirstophe; Derron, Marc-Henri; Jaboyedoff, Michel; Letortu, Pauline; Maquaire, Olivier

    2013-04-01

    Dieppe coastal cliffs, in Normandy, France, are mainly formed by sub-horizontal deposits of chalk and flintstone. Largely destabilized by an intense weathering and the Channel sea erosion, small and large rockfalls are regularly observed and contribute to retrogressive cliff processes. During autumn 2012, cliff and intertidal topographies have been acquired with a Terrestrial Laser Scanner (TLS) and a Mobile Laser Scanner (MLS), coupled with seafloor bathymetries realized with a multibeam echosounder (MBES). MLS is a recent development of laser scanning based on the same theoretical principles of aerial LiDAR, but using smaller, cheaper and portable devices. The MLS system, which is composed by an accurate dynamic positioning and orientation (INS) devices and a long range LiDAR, is mounted on a marine vessel; it is then possible to quickly acquire in motion georeferenced LiDAR point clouds with a resolution of about 15 cm. For example, it takes about 1 h to scan of shoreline of 2 km long. MLS is becoming a promising technique supporting erosion and rockfall assessments along the shores of lakes, fjords or seas. In this study, the MLS system used to acquire cliffs and intertidal areas of the Cap d'Ailly was composed by the INS Applanix POS-MV 320 V4 and the LiDAR Optech Ilirs LR. On the same day, three MLS scans with large overlaps (J1, J21 and J3) have been performed at ranges from 600 m at 4 knots (low tide) up to 200 m at 2.2 knots (up tide) with a calm sea at 2.5 Beaufort (small wavelets). Mean scan resolutions go from 26 cm for far scan (J1) to about 8.1 cm for close scan (J3). Moreover, one TLS point cloud on this test site has been acquired with a mean resolution of about 2.3 cm, using a Riegl LMS Z390i. In order to quantify the reliability of the methodology, comparisons between scans have been realized with the software Polyworks™, calculating shortest distances between points of one cloud and the interpolated surface of the reference point cloud. A Mat

  3. Euclidean Circles and Their Modular Images.

    Science.gov (United States)

    Austin, Joe Dan

    1990-01-01

    Shows a series of Euclidean equations using the Euclidean algorithm to get the greatest common divisor of two integers. Describes the use of the equations to generate a series of circles. Discusses computer generation of Euclidean circles and provides a BASIC program. (YP)

  4. Building Background Knowledge within Literature Circles

    Science.gov (United States)

    Barone, Diane; Barone, Rebecca

    2012-01-01

    The authors examined the strength of literature circles in developing background knowledge--an acknowledged sticking point in the development of understanding for middle graders--with a special focus on the literature circle role of "investigator," where it is student initiative and not teacher direction that guides comprehension. Observing…

  5. Unit Circles and Inverse Trigonometric Functions

    Science.gov (United States)

    Barrera, Azael

    2014-01-01

    Historical accounts of trigonometry refer to the works of many Indian and Arab astronomers on the origin of the trigonometric functions as we know them now, in particular Abu al-Wafa (ca. 980 CE), who determined and named all known trigonometric functions from segments constructed on a regular circle and later on a unit circle (Moussa 2011;…

  6. Bounds on the calving cliff height of marine terminating glaciers

    Science.gov (United States)

    Ma, Yue; Tripathy, Cory S.; Bassis, Jeremy N.

    2017-02-01

    Increased calving and rapid retreat of glaciers can contribute significantly to sea level rise, but the processes controlling glacier retreat remain poorly understood. We seek to improve our understanding of calving by investigating the stress field controlling tensile and shear failure using a 2-D full-Stokes finite element model. Using idealized rectangular geometries, we find that when rapidly sliding glaciers thin to near buoyancy, full thickness tensile failure occurs, similar to observations motivating height-above-buoyancy calving laws. In contrast, when glaciers are frozen to their beds, basal crevasse penetration is suppressed and calving is minimal. We also find that shear stresses are largest when glaciers are thickest. Together, the tensile and shear failure criteria map out a stable envelope in an ice-thickness-water-depth diagram. The upper and lower bounds on cliff height can be incorporated into numerical ice sheet models as boundary conditions, thus bracketing the magnitude of calving rates in marine-terminating glaciers.

  7. Shakespeare Cliff, rempart symbolique aux portes du royaume

    Directory of Open Access Journals (Sweden)

    Jeremy Price

    2006-02-01

    Full Text Available Figure 1 : Clarkson STANFIELD, Shakespeare Cliff, Dover, 1849, 1862« Il est une falaise, dont le front haut et courbeRegarde avec effroi dans l’abîme qu’elle enserre :Conduis-moi jusqu’à son bordEt je remédierai à la misère que tu souffresPar quelque riche objet ; de cet endroitJe n’aurai point besoin de guide. »Les lignes ci-dessus, tirées de l’Acte IV, Scène I du Roi Lear, font allusion aux falaises de Douvres, plus particulièrement à leur point culminant, un grand bloc de calcaire et de cr...

  8. Patent cliff mitigation strategies: giving new life to blockbusters.

    Science.gov (United States)

    Kakkar, Ashish Kumar

    2015-01-01

    With several blockbuster drugs on the brink of another significant patent expiry cliff, innovator pharmaceutical firms are at risk of losing billions of dollars in sales to generic competition. With issues such as staggering R&D costs, reduced productivity and increasing governmental emphasis on pharmacoeconomics, timely planning and implementation of product lifecycle management strategies is becoming indispensable. A variety of strategies designed to mitigate the post-patent expiry revenue loss exist. These approaches range from fairly straightforward measures, such as strategic price cuts and launching own or authorized generics, to complex and lengthy ones, such as new formulations and indications that require companies to reinvent their pharmaceuticals. As patent expiries loom and product pipelines continue to remain thin, proactive planning for generic entry will be critical for pharma companies to drive growth and earnings in a sustainable manner.

  9. Recent acceleration in coastal cliff retreat rates on the south coast of Great Britain.

    Science.gov (United States)

    Hurst, Martin D; Rood, Dylan H; Ellis, Michael A; Anderson, Robert S; Dornbusch, Uwe

    2016-11-22

    Rising sea levels and increased storminess are expected to accelerate the erosion of soft-cliff coastlines, threatening coastal infrastructure and livelihoods. To develop predictive models of future coastal change we need fundamentally to know how rapidly coasts have been eroding in the past, and to understand the driving mechanisms of coastal change. Direct observations of cliff retreat rarely extend beyond 150 y, during which humans have significantly modified the coastal system. Cliff retreat rates are unknown in prior centuries and millennia. In this study, we derived retreat rates of chalk cliffs on the south coast of Great Britain over millennial time scales by coupling high-precision cosmogenic radionuclide geochronology and rigorous numerical modeling. Measured (10)Be concentrations on rocky coastal platforms were compared with simulations of coastal evolution using a Monte Carlo approach to determine the most likely history of cliff retreat. The (10)Be concentrations are consistent with retreat rates of chalk cliffs that were relatively slow (2-6 cm⋅y(-1)) until a few hundred years ago. Historical observations reveal that retreat rates have subsequently accelerated by an order of magnitude (22-32 cm⋅y(-1)). We suggest that acceleration is the result of thinning of cliff-front beaches, exacerbated by regional storminess and anthropogenic modification of the coast.

  10. Recent acceleration in coastal cliff retreat rates on the south coast of Great Britain

    Science.gov (United States)

    Hurst, Martin D.; Rood, Dylan H.; Ellis, Michael A.; Anderson, Robert S.; Dornbusch, Uwe

    2016-11-01

    Rising sea levels and increased storminess are expected to accelerate the erosion of soft-cliff coastlines, threatening coastal infrastructure and livelihoods. To develop predictive models of future coastal change we need fundamentally to know how rapidly coasts have been eroding in the past, and to understand the driving mechanisms of coastal change. Direct observations of cliff retreat rarely extend beyond 150 y, during which humans have significantly modified the coastal system. Cliff retreat rates are unknown in prior centuries and millennia. In this study, we derived retreat rates of chalk cliffs on the south coast of Great Britain over millennial time scales by coupling high-precision cosmogenic radionuclide geochronology and rigorous numerical modeling. Measured 10Be concentrations on rocky coastal platforms were compared with simulations of coastal evolution using a Monte Carlo approach to determine the most likely history of cliff retreat. The 10Be concentrations are consistent with retreat rates of chalk cliffs that were relatively slow (2-6 cmṡy-1) until a few hundred years ago. Historical observations reveal that retreat rates have subsequently accelerated by an order of magnitude (22-32 cmṡy-1). We suggest that acceleration is the result of thinning of cliff-front beaches, exacerbated by regional storminess and anthropogenic modification of the coast.

  11. Identification of Interaction Hot Spots in Structures of Drug Targets on the Basis of Three-Dimensional Activity Cliff Information.

    Science.gov (United States)

    Furtmann, Norbert; Hu, Ye; Gütschow, Michael; Bajorath, Jürgen

    2015-12-01

    Activity cliffs are defined as pairs or groups of structurally similar or analogous compounds that share the same specific activity but have large differences in potency. Although activity cliffs are mostly studied in medicinal chemistry at the level of molecular graphs, they can also be assessed by comparing compound binding modes. If such three-dimensional activity cliffs (3D-cliffs) are studied on the basis of X-ray complex structures, experimental ligand-target interaction details can be taken into account. Rapid growth in the number of 3D-cliffs that can be derived from X-ray complex structures has made it possible to identify targets for which a substantial body of 3D-cliff information is available. Activity cliffs are typically studied to identify structure-activity relationship determinants and aid in compound optimization. However, 3D-cliff information can also be used to search for interaction hot spots and key residues, as reported herein. For six of seven drug targets for which more than 20 3D-cliffs were available, series of 3D-cliffs were identified that were consistently involved in interactions with different hot spots. These 3D-cliffs often encoded chemical modifications resulting in interactions that were characteristic of highly potent compounds but absent in weakly potent ones, thus providing information for structure-based design.

  12. Sea cliff instability hazard assessment at regional scale: a case study in the western coast of Portugal

    Science.gov (United States)

    Marques, Fernando; Taborda, Rui; Carreira, Diogo

    2010-05-01

    Sea cliff evolution is mainly produced by mass movements of different types and sizes, which are a considerable source of natural hazard in coastal areas. For two neighboring counties (Sintra and Cascais) located in the west coast of Portugal, a sea cliff instability statistically based susceptibility assessment was tested in order to analyze the influence of a set of predisposing factors in the prediction of future failures affecting areas located along the cliff top. The coastal areas of Sintra (length of cliffs 24.8km) and Cascais (length of cliffs 22.0km) are examples of contrasting cliff morphology, height (from less than 6m to more than 120m), and rock mass composition and strength (alternating marls and limestones, sandstones, granite, limestones). The inventories of past instabilities were performed by a multitemporal study of aerial photographs from different dates, for the period 1947-2007 (Sintra), and 1947-2008 (Cascais), which enabled the detection and measurement of the local maximum retreat at the cliff top, length of cliff affected and horizontal area lost at the cliff top. The aerial photo based data coupled with field surveys enabled the identification of the type of movements. These are mainly of the rock fall and planar slide types. These aerial photo based studies enabled the identification and measurement of 63 cliff failures at Sintra and 67 at Cascais coasts, with variable spatial density from 0.4 to 20 failures per km of cliff length for the 60/61 years of study period, providing the basis for the division of the cliffs in homogeneous sections in terms of horizontal area lost at the cliff top. Along the different cliff sections, the mean retreat rates varied between 0.0003m/year and 0.025m/year, and the mean values of the maximum local retreat of the cliff top varied between 5m and 17m, with two exceptional cliff failures that caused a net retreat of the cliff top of 70m and 25m. For the assessment of the susceptibility of cliff failures

  13. Advancing the activity cliff concept [v1; ref status: indexed, http://f1000r.es/1wf

    Directory of Open Access Journals (Sweden)

    Ye Hu

    2013-09-01

    Full Text Available The activity cliff concept has experienced increasing interest in medicinal chemistry and chemoinformatics. Activity cliffs have originally been defined as pairs of structurally similar compounds that are active against the same target but have a large difference in potency. Activity cliffs are relevant for structure-activity relationship (SAR analysis and compound optimization because small chemical modifications can be deduced from cliffs that result in large-magnitude changes in potency. In addition to studying activity cliffs on the basis of individual compounds series, they can be systematically identified through mining of compound activity data. This commentary aims to provide a concise yet detailed picture of our current understanding of activity cliffs. It is also meant to introduce the further refined activity cliff concept to a general audience in drug development.

  14. Lines, Circles, Planes and Spheres

    CERN Document Server

    Purdy, George B

    2009-01-01

    Let $S$ be a set of $n$ points in $\\mathbb{R}^3$, no three collinear and not all coplanar. If at most $n-k$ are coplanar and $n$ is sufficiently large, the total number of planes determined is at least $1 + k \\binom{n-k}{2}-\\binom{k}{2}(\\frac{n-k}{2})$. For similar conditions and sufficiently large $n$, (inspired by the work of P. D. T. A. Elliott in \\cite{Ell67}) we also show that the number of spheres determined by $n$ points is at least $1+\\binom{n-1}{3}-t_3^{orchard}(n-1)$, and this bound is best possible under its hypothesis. (By $t_3^{orchard}(n)$, we are denoting the maximum number of three-point lines attainable by a configuration of $n$ points, no four collinear, in the plane, i.e., the classic Orchard Problem.) New lower bounds are also given for both lines and circles.

  15. Plasmid Rolling-Circle Replication.

    Science.gov (United States)

    Ruiz-Masó, J A; MachóN, C; Bordanaba-Ruiseco, L; Espinosa, M; Coll, M; Del Solar, G

    2015-02-01

    Plasmids are DNA entities that undergo controlled replication independent of the chromosomal DNA, a crucial step that guarantees the prevalence of the plasmid in its host. DNA replication has to cope with the incapacity of the DNA polymerases to start de novo DNA synthesis, and different replication mechanisms offer diverse solutions to this problem. Rolling-circle replication (RCR) is a mechanism adopted by certain plasmids, among other genetic elements, that represents one of the simplest initiation strategies, that is, the nicking by a replication initiator protein on one parental strand to generate the primer for leading-strand initiation and a single priming site for lagging-strand synthesis. All RCR plasmid genomes consist of a number of basic elements: leading strand initiation and control, lagging strand origin, phenotypic determinants, and mobilization, generally in that order of frequency. RCR has been mainly characterized in Gram-positive bacterial plasmids, although it has also been described in Gram-negative bacterial or archaeal plasmids. Here we aim to provide an overview of the RCR plasmids' lifestyle, with emphasis on their characteristic traits, promiscuity, stability, utility as vectors, etc. While RCR is one of the best-characterized plasmid replication mechanisms, there are still many questions left unanswered, which will be pointed out along the way in this review.

  16. Circle Detection Based on HSI Color Space

    Institute of Scientific and Technical Information of China (English)

    MAOXia; LIXing-xin; XUEYu-li

    2005-01-01

    A method based on HSI color space is presented to solve the problem of circle detection from color images. In terms of the evaluation to the edge detection method based on intensity, the edge detection based on hue is chosen to process the color image, and the simplified calculation of hue transform is discussed. Then the algorithm of circle detection based on Canny edge detection is proposed. Due to the dispersive distribution of the detected result, Hough transformation and template smooth are used in circle detection, and the proposed method gives a quite good result.

  17. Examination of the Circle Spline Routine

    Science.gov (United States)

    Dolin, R. M.; Jaeger, D. L.

    1985-01-01

    The Circle Spline routine is currently being used for generating both two and three dimensional spline curves. It was developed for use in ESCHER, a mesh generating routine written to provide a computationally simple and efficient method for building meshes along curved surfaces. Circle Spline is a parametric linear blending spline. Because many computerized machining operations involve circular shapes, the Circle Spline is well suited for both the design and manufacturing processes and shows promise as an alternative to the spline methods currently supported by the Initial Graphics Specification (IGES).

  18. Cliff Richard hakkab veini tootma. Marilyn Manson avab isikliku kunstinäituse

    Index Scriptorium Estoniae

    2002-01-01

    Cliff Richardi Portugali viinamarjaistandusest pärinevast veinist "Vida Nova". 20. septembril avab oma albumit "The Golden Age Of Grotesque" lõpetav laulja Marilyn Manson oma esimese kunstinäituse Los Angeleses Hollywoodis

  19. Connotations of architectural culture transmitted in cliff carvings in the Bashu region

    Institute of Scientific and Technical Information of China (English)

    LIN Cong-hua; ZHANG Xing-guo; LIU Zhi-yong

    2006-01-01

    Based on site studies,historical literature investigation and academic communication,this work aims to dig out the cultural significance in architectural and religious aspects conveyed in cliff carvings in the Bashu region.After casting a glance at the origin and evolution of Bashu culture and religion mainly involving Daoism and Buddhism recorded in forms of cliff carvings,we concentrated on discovering the national,regional and folk architectural characters implicated in cliff carvings at different sites within the Bashu region.The cliff carvings in this region vividly depicted the evolution of the architectural culture hereof.The essence of their religious and architectural connotations can be good stuff to be input in today's architectural design philosophy.

  20. Conceptual model for the origin of the Olympus Mons cliffs, Mars: An essential influence of water?

    Science.gov (United States)

    De Blasio, Fabio Vittorio

    2012-08-01

    With a height of 21 km above the mean Martian altitude and a diameter of 600 km, the Olympus Mons of Mars is the highest and one of the largest volcanoes in the Solar System. It is a distinctive shield volcano, formed by stacked sequences of low-viscosity magma. Whereas the central part of the Olympus Mons exhibits slope angles of less than 1-5°, the periphery of the edifice terminates with steep cliffs sloping 12-15° up to 28°. Another remarkable feature is the aureole, a chain of crown-like deposits surrounding the edifice of Olympus Mons from an average distance of 400 km. The aureole deposits, which lack any obvious analogue on the Earth, have been variously interpreted as volcanic products, pyroclastic or ash flows, slow deep-seated deformation, or catastrophic landslides. Numerical simulations and a comparative study of similar volcanic structures on Earth suggest that a volcanic edifice with the characteristics of Olympus Mons cannot be formed without the presence of water at the base. Because of the low cooling rate of lava in sub-aerial conditions, the superposition of purely subaerial lava flows would contribute with gentle slope to the topography. In contrast, the presence of a medium like water increases the convective heat exchange rate by nearly three orders of magnitude, thus stopping the lava flow and causing a slope increase at the borders of the edifice, which subsequently collapses. A model for the evolution of the Olympus Mons is consequently suggested in analogy with the Canary and the Hawaii island on Earth.

  1. Darboux cyclides and webs from circles

    KAUST Repository

    Pottmann, Helmut

    2012-01-01

    Motivated by potential applications in architecture, we study Darboux cyclides. These algebraic surfaces of order ≤4 are a superset of Dupin cyclides and quadrics, and they carry up to six real families of circles. Revisiting the classical approach to these surfaces based on the spherical model of 3D Möbius geometry, we provide computational tools for the identification of circle families on a given cyclide and for the direct design of those. In particular, we show that certain triples of circle families may be arranged as so-called hexagonal webs, and we provide a complete classification of all possible hexagonal webs of circles on Darboux cyclides. © 2011 Elsevier B.V. All rights reserved.

  2. Enhanced Quantization: The particle on the circle

    CERN Document Server

    Geloun, Joseph Ben

    2012-01-01

    Enhanced quantization is an improved program for overcoming difficulties which may arise during an ordinary canonical quantization procedure. We review here how this program applies for a particle on circle.

  3. Development of Waterfall Cliff Face: An Implication from Multitemporal High-definition Topographic Data

    Science.gov (United States)

    Hayakawa, Y. S.; Obanawa, H.

    2015-12-01

    Bedrock knickpoints (waterfalls) often act as erosional front in bedrock rivers, whose geomorphological processes are various. In waterfalls with vertical cliffs, both fluvial erosion and mass movement are feasible to form the landscape. Although morphological changes of such steep cliffs are sometimes visually observed, quantitative and precise measurements of their spatiotemporal distribution have been limited due to poor accessibility to such cliffs. For the clarification of geomorphological processes in such cliffs, multi-temporal mapping of the cliff face at a high resolution can be advantaged by short-range remote sensing approaches. Here we carry out multi-temporal terrestrial laser scanning (TLS), as well as structure-from-motion multi-view stereo (SfM-MVS) photogrammetry based on unmanned aerial system (UAS) for accurate topographic mapping of cliffs around a waterfall. The study site is Kegon Falls in central Japan, having a vertical drop of surface water from top of its overhanging cliff and groundwater outflows from its lower portions. The bedrock consists of alternate layers of jointed andesite lava and conglomerates. The latest major rockfall in 1986 caused approximately 8-m recession of the waterfall lip. Three-dimensional changes of the rock surface were detected by multi-temporal measurements by TLS over years, showing the portions of small rockfalls and surface lowering in the bedrock. Erosion was frequently observed in relatively weak the conglomerates layer, whereas small rockfalls were often found in the andesite layers. Wider areas of the waterfall and cliff were also measured by UAS-based SfM-MVS photogrammetry, improving the mapping quality of the cliff morphology. Point clouds are also projected on a vertical plane to generate a digital elevation model (DEM), and cross-sectional profiles extracted from the DEM indicate the presence of a distinct, 5-10-m deep depression in the cliff face. This appears to have been formed by freeze-thaw and

  4. Sea-cliff erosion at Pacifica, California caused by 1997/98 El Nino storms

    Science.gov (United States)

    Snell, Charles B.; Lajoie, K.R.; Medley, Edward W.

    2000-01-01

    Twelve homes were constructed in 1949 at the top of a sea cliff along Esplanade Drive in the City of Pacifica, located on the northern coast of San Mateo County, California. During the heavy storms of the 1997/98 El Nino winter, a severe episode of cliff retreat undermined seven homes and threatened three others. The geologic, tide, wave, rainfall and wind data were analyzed to determine the causes of this erosion events.

  5. Cliff or Step? Posture-Specific Learning at the Edge of a Drop-Off

    OpenAIRE

    Kretch, Kari S.; Adolph, Karen E.

    2012-01-01

    Infants require locomotor experience to behave adaptively at a drop-off. However, different experimental paradigms (visual cliff and actual gaps and slopes) have generated conflicting findings regarding what infants learn and the specificity of their learning. An actual, adjustable drop-off apparatus was used to investigate whether learning to distinguish a step from a cliff transfers from crawling to walking. Experienced 12-month-old crawlers (n=16) refused to crawl over risky drop-offs but ...

  6. The unsteady nature of sea cliff retreat due to mechanical abrasion, failure and comminution feedbacks

    Science.gov (United States)

    Kline, Shaun W.; Adams, Peter N.; Limber, Patrick W.

    2014-08-01

    Sea cliff retreat is often linked to large waves, heavy precipitation and seismic events, but the specific operative mechanics have not been well constrained. In particular, what is the role of mechanical abrasion by beach sediments in cliff/platform evolution and how does it relate to the episodic nature of cliff retreat observed at certain locations? Here we present a simple, numerical model of sea cliff retreat that incorporates mechanical abrasion of a basal notch, threshold-controlled failure of the cantilevered block, and a feedback mechanism wherein retreat is dependent on the rate of sediment comminution within the surf zone. Using shore platform and cliff characteristics found in two coastal settings (the central California coast and the English North Sea coast), the model produces retreat rates comparable to those observed via field measurements. The highest retreat rates coincide with the steepest shore platforms and increasing wave height. Steeper platforms promote wave access to the cliff toe and, correspondingly, the receding cliff face produces additional accommodation space for the platform beach, preserving the erosive efficacy of the beach sediments. When exposed to energetic wave forcing, the slope of the inner platform segment controls retreat rates for concave platforms, whereas the slope of the outer platform segment exerts greater control for convex platforms. Platform beaches approached a long-term dynamic equilibrium on the concave profiles, leading to more consistent and steady retreat. Platform beaches were ephemeral on convex profiles, mirroring observed sand wave (Ord) migration on the Holderness coast, UK. These findings agree with previous field observations and support mechanical abrasion as a viable cause of temporal heterogeneity in cliff retreat rate for both coastlines.

  7. Modeling the cliff retreat response to base-level change in layered rocks, Colorado Plateau, USA

    Science.gov (United States)

    Ward, D.; Sheehan, C.

    2015-12-01

    The retreat of cliffs is an important mode of erosion in layered rocks of variable strength. For example, the iconic Colorado Plateau landscapes of Grand Canyon, Canyonlands, and Monument Valley owe their unique forms to this process. These landscapes are the end result of incision by trunk streams followed by cliff retreat. Local interactions between stochastic rockfall and first-order channels draining a cliff regulate the cliff retreat response to a base-level fall. However, nonlinear transport dynamics, steep slopes, and variable rock strength challenge the modeling of landscape evolution in these settings. Here, we employ structure-from-motion photogrammetry to generate high-resolution DTMs of a natural experiment site on the Colorado Plateau. The site features a simple, sandstone-over-shale stratigraphy with a continuous gradient in cliffband height and evidence for an ongoing transient response to base level fall. The terrain data inform a high-resolution (dx=5 m), 2D numerical model of cliffband erosion. The model simulates the interaction of three primary processes: fluvial erosion and sediment transport; hillslope transport of regolith, including shallow landsliding; and rockfall from resistant units. Crucially, the model allows us to modify stratigraphy arbitrarily to examine the landscape response to parameters such as thickness, spacing, and dip of resistant units. Results indicate that the contrast in fluvial erodibility sets the pattern of emergence of cliffs as a resistant layer is exhumed, while the difference in weathering rates across rock types sets the rate at which cliffs emerge. Once rockfall begins, erosion rates are modified by the thickness of the resistant layer, which sets the volume of rockfall debris reaching the channels below the cliff. The modeling highlights the need for process-based understanding of the conditions for cliff failure by rockfall and redistribution of the debris in very steep, rapidly-eroding landscapes.

  8. Circle Packing for Origami Design Is Hard

    CERN Document Server

    Demaine, Erik D; Lang, Robert J

    2010-01-01

    We show that deciding whether a given set of circles can be packed into a rectangle, an equilateral triangle, or a unit square are NP-hard problems, settling the complexity of these natural packing problems. On the positive side, we show that any set of circles of total area 1 can be packed into a square of size 8/pi=2.546... These results are motivated by problems arising in the context of origami design.

  9. Nature of short-period microtremors on the cliff-like ground. Part 4; Gakechi kinbo no tanshuki bido. 4

    Energy Technology Data Exchange (ETDEWEB)

    Maiguma, T.; Yoshiike, T. [Waseda University, Tokyo (Japan). School of Science and Engineering

    1996-10-01

    Microtremors were measured on the cliff-like ground with a height about 10 m, to examine the vibration characteristics. Test field-1 near Akabane, Kita-ku, Tokyo is located in a part of Musashino plateau covered with Kanto loam on its surface, and has relatively sound ground. Test field-2 at Machida is located in the western part of Tama hills, and also has Kanto loam on its surface. For the cliff-like ground with inclined angle 70{degree} at Akabane, remarkably predominant frequency 3.2 Hz was observed for the microtremors in the direction perpendicular to the cliff surface. However, this predominant vibration did not become larger due to the damping effects of the reinforcement walls near the end of cliff and the large trees on the cliff. Influence of the cliff-like ground was scarcely observed in the microtremors spectrum in both the directions parallel and vertical to the cliff-surface. From the observation of microtremors with short period on the cliff-like ground with inclined angle around 32{degree} at Machida, influence of cliff-like ground was not observed in the microtremors spectrum in all of the vibrating directions perpendicular, parallel and vertical to the cliff surface. 3 refs., 10 figs.

  10. The mechanics and behavior of cliff swallows during tandem flights.

    Science.gov (United States)

    Shelton, Ryan M; Jackson, Brandon E; Hedrick, Tyson L

    2014-08-01

    Cliff swallows (Petrochelidon pyrrhonota) are highly maneuverable social birds that often forage and fly in large open spaces. Here we used multi-camera videography to measure the three-dimensional kinematics of their natural flight maneuvers in the field. Specifically, we collected data on tandem flights, defined as two birds maneuvering together. These data permit us to evaluate several hypotheses on the high-speed maneuvering flight performance of birds. We found that high-speed turns are roll-based, but that the magnitude of the centripetal force created in typical maneuvers varied only slightly with flight speed, typically reaching a peak of ~2 body weights. Turning maneuvers typically involved active flapping rather than gliding. In tandem flights the following bird copied the flight path and wingbeat frequency (~12.3 Hz) of the lead bird while maintaining position slightly above the leader. The lead bird turned in a direction away from the lateral position of the following bird 65% of the time on average. Tandem flights vary widely in instantaneous speed (1.0 to 15.6 m s(-1)) and duration (0.72 to 4.71 s), and no single tracking strategy appeared to explain the course taken by the following bird.

  11. Subaerial Chalk Cliff Failures on the English Channel Coast, Based on Field Data From Recent Collapses

    Science.gov (United States)

    DUPERRET, A.; MARTINEZ, A.; GENTER, A.; MORTIMORE, R. N.; WATREMEZ, P.

    2001-12-01

    The chalk cliffs along the English Channel coast are currently retreating at a mean rate of 0.5 m/year. However, the erosion is not constant over time, but occurs by catastrophic collapses. For the last three years, a minimum of 40 collapses have been observed along the French chalk coastline (120 km long) and about 10 collapses along the English chalk coastline (40 km long). The observed collapsed volumes are varying from 150 000 m3 (Beachy Head, UK) to a few m3, whereas the cliff heights are varying from 20 to 200m. Two kinds of scar extension have been observed on the cliff face: either the lower part only with few volumes involved, either the whole cliff height for the largest events. Two main cases of scar shape have been evidenced: (1) scar with a vertical upper part and a curved lower part with large striations and crushed chalk (Puys, France). The rupture process is an overall sliding process, with tearing of the upper part of the cliff and shearing in its lower part. The failure is mainly controlled by rain-fall and occurred by water pressure increase on impervious marl seams of the chalk (Duperret et al., in press, JCR). (2) scar with a regular and rectilinear profile, without any striation (Birling Gap, UK). The rupture propagates along pre-existing joint sets, parallel oriented to the cliff face. Locally, pre-existing large-scale transverse fractures may bound the lateral propagation of the scar. Where the scars extend all over the cliff height, the failure is mainly controlled by continental water infiltration. However the role of water through fractured chalk may differ according to the fracture pattern. Where the scars are restrained to the lower part of the cliff, the upward extension of the scars are bounded by lithological features of the chalk, as horizontal flint bands or stratification. In this case, the role of marine parameters, as wave impact at the toe of the cliff may be invoked as a significant triggering parameter contributing to failure

  12. The visual cliff's forgotten menagerie: rats, goats, babies, and myth-making in the history of psychology.

    Science.gov (United States)

    Rodkey, Elissa N

    2015-01-01

    Eleanor Gibson and Richard Walk's famous visual cliff experiment is one of psychology's classic studies, included in most introductory textbooks. Yet the famous version which centers on babies is actually a simplification, the result of disciplinary myth-making. In fact the visual cliff's first subjects were rats, and a wide range of animals were tested on the cliff, including chicks, turtles, lambs, kid goats, pigs, kittens, dogs, and monkeys. The visual cliff experiment was more accurately a series of experiments, employing varying methods and a changing apparatus, modified to test different species. This paper focuses on the initial, nonhuman subjects of the visual cliff, resituating the study in its original experimental logic, connecting it to the history of comparative psychology, Gibson's interest in comparative psychology, as well as gender-based discrimination. Recovering the visual cliff's forgotten menagerie helps to counter the romanticization of experimentation by focusing on the role of extrascientific factors, chance, complexity, and uncertainty in the experimental process.

  13. Maxi-circles and mini-circles in kinetoplast DNA from Trypanosoma cruzi.

    NARCIS (Netherlands)

    W. Leon; A.C.C. Frasch; J.H.J. Hoeijmakers (Jan); F. Fase-Fowler; P. Borst (Piet); F. Brunel; J. Davison

    1980-01-01

    textabstractMaxi-circles are a minor component of kinetoplast DNAs from all trypanosomatids studied, but they have not previously been found in Trypanosoma cruzi; We have spread intact kinetoplast DNA from the epimastigotes of strain Y in protein monolayers and analysed the mini-circle networks by e

  14. Expanding-Circle Students Learning "Standard English" in the Outer-Circle Asia

    Science.gov (United States)

    Kobayashi, Yoko

    2011-01-01

    Drawing upon Kachru's concentric circles of English, the present study explores whether middle-class Japanese students who chose to study English solo at private language schools in Singapore diverge from many others who (wish to) study inner-circle English. The study is stimulated by the repeated interdisciplinary findings that, in spite of the…

  15. Recreation impacts to cliff resources in the Potomac Gorge: Final report, June 2011

    Science.gov (United States)

    Marion, Jeffrey L.; Carr, C.; Davis, C.A.

    2011-01-01

    Managers of the National Park Service (NPS) are directed by law to accommodate appropriate types and amounts of visitation while ensuring that: any adverse impacts are the minimum necessary, unavoidable, cannot be further mitigated, and do not constitute impairment or derogation of park resources and values. (NPS 2006). The increasing popularity of the national park system presents substantial management challenges. High visitatation may cause unacceptable impacts to fragile natural and cultural resources, and may also cause crowding and other social impacts, which can also degrade the quality of visitor experiences. Responding to these concerns, NPS managers at Chesapeake & Ohio Canal National Historical Park (CHOH) and George Washington Memorial Parkway (GWMP) sponsored this research within the upper Potomac Gorge portions of these parks to investigate visitation-related impacts to the park?s cliff resources. The cliffs and rocky areas within the Great Falls and Mather Gorge areas provide important habitats for numerous sensitive rare plants and plant communities. A recent General Management Planning process for Great Falls Park (GFP), a portion of GWMP, highlighted the potential impacts of cliff-associated recreational activities, including hiking, climbing, and fishing, on sensitive cliff resources. The planning process identified the need for development of a Climbing Management Plan and a Trail Plan to more specifically address site and visitor management actions needed to protect rare and sensitive natural and cultural resources. Good science to assess cliff-associated rare plants and communities and to determine the existing and potential effects of cliff-related recreational activities is required for these new planning efforts. This research is designed to specifically address these informational needs and to assist park managers on both sides of the river with current and future cliff and recreation management decisions.

  16. Automatic Delineation of Sea-Cliff Limits Using Lidar-Derived High-Resolution DEMs in Southern California

    Science.gov (United States)

    Palaseanu, M.; Danielson, J.; Foxgrover, A. C.; Barnard, P.; Thatcher, C.; Brock, J. C.

    2014-12-01

    Seacliff erosion is a serious hazard with implications for coastal management, and is often estimated using successive hand digitized cliff tops or bases (toe) to assess cliff retreat. Traditionally the recession of the cliff top or cliff base is obtained from aerial photographs, topographic maps, or in situ surveys. Irrespective of how or what is measured to categorize cliff erosion, the position of the cliff top and cliff base is important. Habitually, the cliff top and base are hand digitized even when using high resolution lidar derived DEMs. Even if efforts were made to standardize and eliminate as much as possible any digitizing subjectivity, the delineation of cliffs is time consuming, and depends on the analyst's interpretation. We propose an automatic procedure to delineate the cliff top and base from high resolution bare-earth DEMs. The method is based on bare-earth high-resolution DEMs, generalized coastal shorelines and approximate measurements of distance between the shoreline and the cliff top. The method generates orthogonal transects and profiles with a minimum spacing equal to the DEM resolution and extracts for each profile xyz coordinates for cliff's top and toe, as well as second major positive and negative inflections (second top and toe) along the profile. The difference between the automated and digitized top and toe, respectively, is smaller than the DEM error margin for over 82% of the top points and 86% of the toe points along a stretch of coast in Del Mar, CA. The larger errors were due either to the failure to remove all vegetation from the bare-earth DEM or errors of interpretation during hand digitizing. The automatic method was further applied between Point Conception and Los Angeles Harbor, CA. This automatic method is repeatable, takes advantage of the bare-earth high-resolution, and is more efficient.

  17. ENTREPRENEURSHIP EDUCATION AND THE ECONOMY VICIOUS CIRCLES

    Directory of Open Access Journals (Sweden)

    MEDAR LUCIAN ION

    2015-06-01

    Full Text Available Education for sustainable development, involves training honest, active, social and creative persons for ensuring the link between environment, society, economy and politics. Trained entrepreneurs in sustainable development, are the engine system which can bring an economic prosperity. Lack of entrepreneurial education in the last 25 years has led accentuated conditions to avoiding economic development in all reference fields where added value can be achieved. Running away from excessive taxation led to the establishment of vicious circles in the economy. Vicious circles of the economy can be found in saving, tax policy, productive investment and the informal economy. Through this study will present the importance of entrepreneurship education in the real economy and some specifications to exit entrepreneurs from vicious circles of the economy.

  18. Synchronisation in Coupled Sine Circle Maps

    CERN Document Server

    Chatterjee, N; Chatterjee, Nandini; Gupte, Neelima

    1995-01-01

    We study the spatially synchronized and temporally periodic solutions of a 1-d lattice of coupled sine circle maps. We carry out an analytic stability analysis of this spatially synchronized and temporally periodic case and obtain the stability matrix in a neat block diagonal form. We find spatially synchronized behaviour over a substantial range of parameter space. We have also extended the analysis to higher spatial periods with similar results. Numerical simulations for various temporal periods of the synchronized solution, reveal that the entire structure of the Arnold tongues and the devil's staircase seen in the case of the single circle map can also be observed for the synchronized coupled sine circle map lattice. Our formalism should be useful in the study of spatially periodic behaviour in other coupled map lattices.

  19. Packing circles and spheres on surfaces

    KAUST Repository

    Schiftner, Alexander

    2009-12-01

    Inspired by freeform designs in architecture which involve circles and spheres, we introduce a new kind of triangle mesh whose faces\\' incircles form a packing. As it turns out, such meshes have a rich geometry and allow us to cover surfaces with circle patterns, sphere packings, approximate circle packings, hexagonal meshes which carry a torsion-free support structure, hybrid tri-hex meshes, and others. We show how triangle meshes can be optimized so as to have the incircle packing property. We explain their relation to conformal geometry and implications on solvability of optimization. The examples we give confirm that this kind of meshes is a rich source of geometric structures relevant to architectural geometry.

  20. Packing circles and spheres on surfaces

    KAUST Repository

    Schiftner, Alexander

    2009-01-01

    Inspired by freeform designs in architecture which involve circles and spheres, we introduce a new kind of triangle mesh whose faces\\' incircles form a packing. As it turns out, such meshes have a rich geometry and allow us to cover surfaces with circle patterns, sphere packings, approximate circle packings, hexagonal meshes which carry a torsion-free support structure, hybrid tri-hex meshes, and others. We show how triangle meshes can be optimized so as to have the incircle packing property. We explain their relation to conformal geometry and implications on solvability of optimization. The examples we give confirm that this kind of meshes is a rich source of geometric structures relevant to architectural geometry. © 2009 ACM.

  1. A floral survey of cliff habitats along Bull Run at Manassas National Battlefield Park, Virginia, 2014

    Science.gov (United States)

    Stroh, Esther D.; Struckhoff, Matthew A.; Grabner, Keith W.

    2015-08-06

    Isolated patches of native vegetation in human-modified landscapes are important reservoirs of biological diversity because they may be the only places in which rare or native species can persist. Manassas National Battlefield Park, Virginia, is an island embedded in a matrix of intensively modified lands; it is becoming increasingly isolated due to growth of the greater Washington, D.C. area. A series of cliffs along Bull Run support an eastern white pine community disjunct from its more typical range in the Appalachian Mountains. Cliffs frequently support vegetation communities that differ from surrounding habitat. In this ecological context, the cliffs along Bull Run are islands of specialized habitat within an island of natural and semi-natural communities (the park), surrounded by a human-dominated landscape. A floral survey of these cliffs was a top priority identified by the National Park Service National Capital Region via the National Resource Preservation Program; in 2014, we completed a floral survey of 11 cliffs in the park. We recorded 282 species in 194 genera and 83 families, including 23 newly documented species for the park.

  2. Partial covering of a circle by equal circles. Part I: The mechanical models

    Directory of Open Access Journals (Sweden)

    Zsolt Gáspár

    2014-05-01

    Full Text Available How must n equal circles of given radius be placed so that they cover as great a part of the area of the unit circle as possible? To analyse this mathematical problem, mechanical models are introduced. A generalized tensegrity structure is associated with a maximum area configuration of the n circles, whose equilibrium configuration is determined numerically with the method of dynamic relaxation, and the stability of equilibrium is investigated by means of the stiffness matrix of the tensegrity structure. In this Part I, the principles of the models are presented, while an application will be shown in the forthcoming Part II.

  3. Sea cliff instability susceptibility at regional scale: a statistically based assessment in southern Algarve, Portugal

    Directory of Open Access Journals (Sweden)

    F. M. S. F. Marques

    2013-05-01

    along their top. The study was based on the application of the bivariate Information Value and multivariate Logistic regression statistical methods, using a set of predisposing factors for cliff failures, mainly related with geology (lithology, bedding dip, faults and geomorphology (maximum and mean slope, height, aspect, plan curvature, toe protection which were correlated with a photogrammetry based inventory of cliff failures occurred in a 60 yr period (1947–2007. The susceptibility models were validated against the inventory data using standard success rate and ROC curves, and provided encouraging results, indicating that the proposed approaches are effective for susceptibility assessment. The results obtained also stress the need for improvement of the predisposing factors to be used in this type of studies and the need of detailed and systematic cliff failures inventories.

  4. Analysis of Cliff-Ramp Structures in Homogeneous Scalar Turbulence by the Method of Line Segments

    Science.gov (United States)

    Gauding, Michael; Goebbert, Jens Henrik; Peters, Norbert; Hasse, Christian

    2015-11-01

    The local structure of a turbulent scalar field in homogeneous isotropic turbulence is analyzed by direct numerical simulations (DNS). A novel signal decomposition approach is introduced where the signal of the scalar along a straight line is partitioned into segments based on the local extremal points of the scalar field. These segments are then parameterized by the distance between adjacent extremal points and a segment-based gradient. Joint statistics of the length and the segment-based gradient provide novel understanding about the local structure of the turbulent field and particularly about cliff-ramp-like structures. Ramp-like structures are unveiled by the asymmetry of joint distribution functions. Cliff-like structures are further analyzed by conditional statistics and it is shown from DNS that the width of cliffs scales with the Kolmogorov length scale.

  5. On circle map coupled map lattice

    CERN Document Server

    Ahmed, E

    2002-01-01

    Circle map in one and two dimensions is studied. Both its stability, synchronization using bounded control and persistence is discussed. This work is expected to be applicable in ecology where spatial effects are known to be important. Also it will be relevant to systems where delay effects are not negligible.

  6. Syllable Circles for Pronunciation Learning and Teaching

    Science.gov (United States)

    Whipple, John; Cullen, Charlie; Gardiner, Keith; Savage, Tim

    2015-01-01

    Syllable Circles are interactive visualizations representing prominence as a feature in short phrases or multi-syllable words. They were designed for computer-aided pronunciation teaching. This study explores whether and how interactive visualizations can affect language learners' awareness of prominence, or stress, in English pronunciation. The…

  7. Information flow through the disaster circle

    DEFF Research Database (Denmark)

    Egedorf, Maren Marie; Villanueva Holm-Nielsen, Pablo

    2015-01-01

    The traditional view of the disaster circle is phase based. Disaster and development professionals recognize that the actions carried out in the various phases of the disaster management cycle are overlapping and build upon each other, having resilience as the overall goal. However information do...

  8. Community Social Work and the Learning Circle

    Science.gov (United States)

    Lavan, Ann

    2008-01-01

    Outlines an approach for introducing students to Community Social Work by use of clear, engaging stated objectives. Approach is called the Learning Circle and was devised as a tool to enhance student participation and to stimulate networking, dialogue and conversation about social work commitment to community intervention and community-based…

  9. Mathematics Teachers Circle around Problem Solving

    Science.gov (United States)

    Fernandes, Anthony; Koehler, Jacob; Reiter, Harold

    2011-01-01

    Making problem solving a central part of teaching may be challenging to teachers who have limited experiences in learning and teaching mathematics in this way. Math Teachers' Circles were developed with the aim of establishing a "culture of problem solving" among middle school mathematics teachers. This culture could then be carried back into…

  10. Quantization of Presymplectic Manifolds and Circle Actions

    CERN Document Server

    Silva, A C; Tolman, S; Silva, Ana Canas da; Karshon, Yael; Tolman, Susan

    1997-01-01

    We prove several versions of "quantization commutes with reduction" for circle actions on manifolds that are not symplectic. Instead, these manifolds possess a weaker structure, such as a spin^c structure. Our theorems work whenever the quantization data and the reduction data are compatible; this condition always holds if we start from a presymplectic (in particular, symplectic) manifold.

  11. AN ITERATIVE EQUATION ON THE UNIT CIRCLE

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A functional equation of nonlinear iterates is discussed on the circle S1 for its continuous solutions and differentiable solutions. By lifting to R, the existence, uniqueness and stability of those solutions are obtained. Techniques of continuation are used to guarantee the preservation of continuity and differentiability in lifting.

  12. THREE CIRCLES MODEL REVITALISASI LEMBAGA PENGELOLA ZAKAT

    Directory of Open Access Journals (Sweden)

    Yulinartati Yulinartati

    2013-12-01

    of revitalization of management of zakat, infak, and sadaqah institutions. Type of research is survey research by applying descriptive qualitative method. The results of this study found that management needs to revitalize institutions of zakat, infak, and sedekah as described in the Three Circles Model.

  13. Treatment of infraorbital dark circles using 694-nm fractional Q-switched ruby laser.

    Science.gov (United States)

    Xu, Tian-Hua; Li, Yuan-Hong; Chen, John Z S; Gao, Xing-Hua; Chen, Hong-Duo

    2016-12-01

    The objective of this study was to evaluate the efficacy and safety of using a 694-nm fractional Q-switched ruby laser to treat infraorbital dark circles. Thirty women with infraorbital dark circles (predominant color: dark/brown) participated in this open-labeled study. The participants received eight sessions of 694-nm fractional Q-switched ruby laser treatment using a fluence of 3.0-3.5 J/cm(2), at an interval of 7 days. The melanin deposition in the lesional skin was observed in vivo using reflectance confocal microscopy (RCM). The morphological changes were evaluated using a global evaluation, an overall self-assessment, and a Mexameter. Twenty-eight of the 30 patients showed global improvements that they rated as excellent or good. Twenty-six patients rated their overall satisfaction as excellent or good. The melanin index indicated a substantial decrease from 240.44 (baseline) to 194.56 (P dark/brown infraorbital dark circles is caused by increased melanin deposition in the upper dermis. The treatment of these infraorbital dark circles using a 694-nm fractional QSR laser is safe and effective.

  14. Determining Variation in Flight Speed and Pattern of Cliff Swallow Using Video Frame Analysis

    Directory of Open Access Journals (Sweden)

    E Santosh,

    2014-03-01

    Full Text Available Ability to fly faster varies from one species of birds to the other. Take off from their nest, settling on the nest or migratory speed of flight is different from one bird to the other, so is also to Cliff Swallows. Many workers have tried different ways to analyze the flight speed of birds using principles of mechanics and physics. Here we have analyzed take off and settling in speeds of Indian Cliff Swallows by applying Video frame analysis technique with fixed focal length.

  15. Assessing species habitat using Google Street View: a case study of cliff-nesting vultures.

    Science.gov (United States)

    Olea, Pedro P; Mateo-Tomás, Patricia

    2013-01-01

    The assessment of a species' habitat is a crucial issue in ecology and conservation. While the collection of habitat data has been boosted by the availability of remote sensing technologies, certain habitat types have yet to be collected through costly, on-ground surveys, limiting study over large areas. Cliffs are ecosystems that provide habitat for a rich biodiversity, especially raptors. Because of their principally vertical structure, however, cliffs are not easy to study by remote sensing technologies, posing a challenge for many researches and managers working with cliff-related biodiversity. We explore the feasibility of Google Street View, a freely available on-line tool, to remotely identify and assess the nesting habitat of two cliff-nesting vultures (the griffon vulture and the globally endangered Egyptian vulture) in northwestern Spain. Two main usefulness of Google Street View to ecologists and conservation biologists were evaluated: i) remotely identifying a species' potential habitat and ii) extracting fine-scale habitat information. Google Street View imagery covered 49% (1,907 km) of the roads of our study area (7,000 km²). The potential visibility covered by on-ground surveys was significantly greater (mean: 97.4%) than that of Google Street View (48.1%). However, incorporating Google Street View to the vulture's habitat survey would save, on average, 36% in time and 49.5% in funds with respect to the on-ground survey only. The ability of Google Street View to identify cliffs (overall accuracy = 100%) outperformed the classification maps derived from digital elevation models (DEMs) (62-95%). Nonetheless, high-performance DEM maps may be useful to compensate Google Street View coverage limitations. Through Google Street View we could examine 66% of the vultures' nesting-cliffs existing in the study area (n = 148): 64% from griffon vultures and 65% from Egyptian vultures. It also allowed us the extraction of fine-scale features of cliffs

  16. Soft-Cliff Retreat, Self-Organized Critical Phenomena in the Limit of Predictability?

    Science.gov (United States)

    Paredes, Carlos; Godoy, Clara; Castedo, Ricardo

    2015-03-01

    The coastal erosion along the world's coastlines is a natural process that occurs through the actions of marine and subaerial physico-chemical phenomena, waves, tides, and currents. The development of cliff erosion predictive models is limited due to the complex interactions between environmental processes and material properties over a wide range of temporal and spatial scales. As a result of this erosive action, gravity driven mass movements occur and the coastline moves inland. Like other studied earth natural and synthetically modelled phenomena characterized as self-organized critical (SOC), the recession of the cliff has a seemingly random, sporadic behavior, with a wide range of yearly recession rate values probabilistically distributed by a power-law. Usually, SOC systems are defined by a number of scaling features in the size distribution of its parameters and on its spatial and/or temporal pattern. Particularly, some previous studies of derived parameters from slope movements catalogues, have allowed detecting certain SOC features in this phenomenon, which also shares the recession of cliffs. Due to the complexity of the phenomenon and, as for other natural processes, there is no definitive model of recession of coastal cliffs. In this work, various analysis techniques have been applied to identify SOC features in the distribution and pattern to a particular case: the Holderness shoreline. This coast is a great case study to use when examining coastal processes and the structures associated with them. It is one of World's fastest eroding coastlines (2 m/yr in average, max observed 22 m/yr). Cliffs, ranging from 2 m up to 35 m in height, and made up of glacial tills, mainly compose this coast. It is this soft boulder clay that is being rapidly eroded and where coastline recession measurements have been recorded by the Cliff Erosion Monitoring Program (East Riding of Yorkshire Council, UK). The original database has been filtered by grouping contiguous

  17. Main factors determining bioerosion patterns on rocky cliffs in a drowned valley estuary in the Colombian Pacific (Eastern Tropical Pacific)

    Science.gov (United States)

    Cobo-Viveros, Alba Marina; Cantera-Kintz, Jaime Ricardo

    2015-10-01

    Bioerosion is an important process that destroys coastal rocks in the tropics. However, the rates at which this process occurs, the organisms involved, and the dynamics of rocky cliffs in tropical latitudes have been less studied than in temperate and subtropical latitudes. To contribute to the knowledge of the bioerosion process in rocky cliffs on the Pacific coast of Colombia (Eastern Tropical Pacific) we compared: 1) boring volume, 2) grain size distribution of the rocks, and 3) rock porosity, across three tidal zones of two cliffs with different wave exposure; these factors were related to the bioeroding community found. We observed that cliffs that were not exposed to wave action (IC, internal cliffs) exhibited high percentages of clays in their grain size composition, and a greater porosity (47.62%) and perforation (15.86%) than exposed cliffs (EC, external cliffs). However, IC also exhibited less diversity and abundance of bioeroding species (22 species and 314 individuals, respectively) compared to the values found in EC (41.11%, 14.34%, 32 and 491, respectively). The most abundant bioeroders were Petrolisthes zacae in IC and Pachygrapsus transversus in EC. Our findings show that the tidal zone is the common factor controlling bioerosion on both cliffs; in addition to the abundance of bioeroders on IC and the number of bioeroding species on EC. The integration of geology, sedimentology, and biology allows us to obtain a more comprehensive view of the patterns and trends in the process of bioerosion.

  18. 78 FR 4467 - UniStar Nuclear Energy, Combined License Application for Calvert Cliffs Power Plant, Unit 3...

    Science.gov (United States)

    2013-01-22

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION UniStar Nuclear Energy, Combined License Application for Calvert Cliffs Power Plant, Unit 3, Exemption 1.0 Background UniStar Nuclear Energy (UNE), on behalf of Calvert Cliffs Nuclear Project, LLC...

  19. 33 CFR 165.505 - Security Zone; Calvert Cliffs Nuclear Power Plant, Chesapeake Bay, Calvert County, Maryland.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Security Zone; Calvert Cliffs Nuclear Power Plant, Chesapeake Bay, Calvert County, Maryland. 165.505 Section 165.505 Navigation and... Areas Fifth Coast Guard District § 165.505 Security Zone; Calvert Cliffs Nuclear Power Plant,...

  20. Geologic controls on transgressive-regressive cycles in the upper Pictured Cliffs sandstone and coal geometry in the lower Fruitland Formation, Northern San Juan Basin, New Mexico and Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Ambrose, W.A.; Ayers, W.B. [University of Texas, Austin, TX (United States)

    2007-08-15

    Three upper Pictured Cliffs Sandstone tongues in the northern part of the San Juan Basin record high-frequency transgressive episodes during the Late Cretaceous and are inferred to have been caused by eustatic sea level rise coincident with differential subsidence. Outcrop and subsurface studies show that each tongue is an amalgamated barrier strand-plain unit up to 100 ft (30 m) thick. Upper Pictured Cliffs barrier strand-plain sandstones underlie and bound thickest Fruitland coal seams on the seaward side. Controls on Fruitland coal-seam thickness and continuity are a function of local facies distribution in a coastal-plain setting, shoreline positions related to transgressive-regressive cycles, and basin subsidence. During periods of relative sea level rise, the Pictured Cliffs shoreline was temporarily stabilized, allowing thick, coastal-plain peats to accumulate. Although some coal seams in the lower Fruitland tongue override abandoned Pictured Cliffs shoreline deposits, many pinch out against them. Differences in the degree of continuity of these coal seams relative to coeval shoreline sandstones are attributed to either differential subsidence in the northern part of the basin, multiple episodes of sea level rise, local variations in accommodation and progradation, stabilization of the shoreline by aggrading peat deposits, or a combination of these factors. Fruitland coalbed methane resources and productivity are partly controlled by coal-seam thickness; other important factors include thermal maturity, fracturing, and overpressuring. The dominant production trend occurs in the northern part of the basin and is oriented northwestward, coinciding with the greatest Fruitland net coal thickness.

  1. Locating a circle on the plane using the minimax criterion

    OpenAIRE

    2006-01-01

    We consider the problem of locating a circle with respect to existing facilities on the plane, such that the largest weighted distance between the circle and the facilities is minimized. The problem properties are analyzed, and a solution procedure proposed.

  2. Locating a circle on the plane using the minimax criterion

    DEFF Research Database (Denmark)

    Brimberg, Jack; Juel, Henrik; Schoebel, Anita

    2006-01-01

    We consider the problem of locating a circle with respect to existing facilities on the plane, such that the largest weighted distance between the circle and the facilities is minimized. The problem properties are analyzed, and a solution procedure proposed.......We consider the problem of locating a circle with respect to existing facilities on the plane, such that the largest weighted distance between the circle and the facilities is minimized. The problem properties are analyzed, and a solution procedure proposed....

  3. A Spring Playscape Project: Building a Tree Circle

    Science.gov (United States)

    Keeler, Rusty

    2009-01-01

    The Tree Circle is a green gathering area for children made by planting trees in a circle. For children, the Tree Circle becomes a magical place for dramatic play, quiet retreat, or lively nature exploration. For teachers and parents it becomes a shady grove for snacks and stories. The trees create a sweet spot that changes during the seasons and…

  4. Optimal State Estimation of Pure Qubits on Circles

    Institute of Scientific and Technical Information of China (English)

    A. Ugulava; ZHANG Li-Hua; L. Chotorlishvili; SONG Wei; V. Skrinnikov; CAO Zhuo-Liang; G. Mchedlishvili

    2008-01-01

    We consider the problem of state estimation of qubits chosen from circles. It is shown that any qubit encoded in pairs chosen from a fixed circle parallel to the x-y equator with different phases contains the same information. We also investigate the problem of state estimation of qubits from three circles. The optimal estimation fidelity is derived.

  5. The "Us" in Discuss: Grouping in Literature Circles

    Science.gov (United States)

    Batchelor, Katherine

    2012-01-01

    This article describes one middle school teacher's use of literature circles using heterogeneous grouping. It begins with a brief rationale for using literature circles in the language arts classroom. Next, it describes techniques to form literature circles. Then, it shares how to build and establish a supportive environment within each group. It…

  6. Investigating ice cliff evolution and contribution to glacier mass-balance using a physically-based dynamic model

    Science.gov (United States)

    Buri, Pascal; Miles, Evan; Ragettli, Silvan; Brun, Fanny; Steiner, Jakob; Pellicciotti, Francesca

    2016-04-01

    Supraglacial cliffs are a surface feature typical of debris-covered glaciers, affecting surface evolution, glacier downwasting and mass balance by providing a direct ice-atmosphere interface. As a result, melt rates can be very high and ice cliffs may account for a significant portion of the total glacier mass loss. However, their contribution to glacier mass balance has rarely been quantified through physically-based models. Most cliff energy balance models are point scale models which calculate energy fluxes at individual cliff locations. Results from the only grid based model to date accurately reflect energy fluxes and cliff melt, but modelled backwasting patterns are in some cases unrealistic, as the distribution of melt rates would lead to progressive shallowing and disappearance of cliffs. Based on a unique multitemporal dataset of cliff topography and backwasting obtained from high-resolution terrestrial and aerial Structure-from-Motion analysis on Lirung Glacier in Nepal, it is apparent that cliffs exhibit a range of behaviours but most do not rapidly disappear. The patterns of evolution cannot be explained satisfactorily by atmospheric melt alone, and are moderated by the presence of supraglacial ponds at the base of cliffs and by cliff reburial with debris. Here, we document the distinct patterns of evolution including disappearance, growth and stability. We then use these observations to improve the grid-based energy balance model, implementing periodic updates of the cliff geometry resulting from modelled melt perpendicular to the ice surface. Based on a slope threshold, pixels can be reburied by debris or become debris-free. The effect of ponds are taken into account through enhanced melt rates in horizontal direction on pixels selected based on an algorithm considering distance to the water surface, slope and lake level. We use the dynamic model to first study the evolution of selected cliffs for which accurate, high resolution DEMs are available

  7. Function representation with circle inversion map systems

    Science.gov (United States)

    Boreland, Bryson; Kunze, Herb

    2017-01-01

    The fractals literature develops the now well-known concept of local iterated function systems (using affine maps) with grey-level maps (LIFSM) as an approach to function representation in terms of the associated fixed point of the so-called fractal transform. While originally explored as a method to achieve signal (and 2-D image) compression, more recent work has explored various aspects of signal and image processing using this machinery. In this paper, we develop a similar framework for function representation using circle inversion map systems. Given a circle C with centre õ and radius r, inversion with respect to C transforms the point p˜ to the point p˜', such that p˜ and p˜' lie on the same radial half-line from õ and d(õ, p˜)d(õ, p˜') = r2, where d is Euclidean distance. We demonstrate the results with an example.

  8. Robust Controller Synthesis Based on Circle Criterion

    Science.gov (United States)

    Fuwa, Katsuhiko; Kato, Hiroyuki; Kando, Hisashi

    It is well-known that stability margins (gain and phase margins) are important quantitative indicators for evaluating stability in feedback control system synthesis. However, when we use conventional techniques based on such stability margins, it may be difficult to suppress the vibration from high-order modes of mechanical system. This paper proposes the robust controller synthesis which achieves both the conventional stability margins and the second phase margin which is a quantitative indicator for suppressing the vibration. The basic idea is to synthesize controller such that the Nyquist locus of open-loop transfer function encircles the immediate outer side of the circle which is specified by the conventional stability margins and the second phase margin. This is formulated as modified H∞ mixed sensitivity problem with the weighting constants which are decided by the center and radius of the circle.

  9. Circle Points Discharge Tube Current Controller

    Institute of Scientific and Technical Information of China (English)

    Meng Jinjia; Meng Lisheng

    2005-01-01

    Circle points discharge tube current controller is a new type device to limit theoutput of high voltage discharge current. Circle points uniform corona discharge to form airionization current in the discharge tube. On the outside, even if the discharge electrode is sparkdischarging or the two discharge electrodes are short circuited, the air ionization current in the tuberemains within a stable range, and there is no spark discharge. In this case, when the dischargecurrent only increases slightly, the requirement to limited current is obtained. By installing thecontroller at a discharge pole with a small power but high voltage supply, we can realize the shiftbetween the continuous spark line discharge and corona discharge. This provides a new simpledevice for spark discharge research and is a supplement to the Townsend discharge experiment.

  10. CHARACTERISTICS OF HYDROCARBON EXPLOITATION IN ARCTIC CIRCLE

    Directory of Open Access Journals (Sweden)

    Vanja Lež

    2013-12-01

    Full Text Available The existence of large quantities of hydrocarbons is supposed within the Arctic Circle. Assumed quantities are 25% of the total undiscovered hydrocarbon reserves on Earth, mostly natural gas. Over 500 major and minor gas accumulations within the Arctic Circle were discovered so far, but apart from Snøhvit gas field, there is no commercial exploitation of natural gas from these fields. Arctic gas projects are complicated, technically hard to accomplish, and pose a great threat to the return of investment, safety of people and equipment and for the ecosystem. Russia is a country that is closest to the realization of the Arctic gas projects that are based on the giant gas fields. The most extreme weather conditions in the seas around Greenland are the reason why this Arctic region is the least explored and furthest from the realization of any gas project (the paper is published in Croatian .

  11. The glass cliff: when and why women are selected as leaders in crisis contexts.

    Science.gov (United States)

    Bruckmüller, Susanne; Branscombe, Nyla R

    2010-09-01

    The glass cliff refers to women being more likely to rise to positions of organizational leadership in times of crisis than in times of success, and men being more likely to achieve those positions in prosperous times. We examine the role that (a) a gendered history of leadership and (b) stereotypes about gender and leadership play in creating the glass cliff. In Expt 1, participants who read about a company with a male history of leadership selected a male future leader for a successful organization, but chose a female future leader in times of crisis. This interaction--between company performance and gender of the preferred future leader--was eliminated for a counter-stereotypic history of female leadership. In Expt 2, stereotypically male attributes were most predictive of leader selection in a successful organization, while stereotypically female attributes were most predictive in times of crisis. Differences in the endorsement of these stereotypes, in particular with regard to the ascription of lower stereotypically female attributes to the male candidate mediated the glass cliff effect. Overall, results suggest that stereotypes about male leadership may be more important for the glass cliff effect than stereotypes about women and leadership.

  12. The Cliff:A Deconstructive Analysis of The Catcher in the Rye

    Institute of Scientific and Technical Information of China (English)

    唐建南

    2012-01-01

    Just as the cliff serves as a demarcation between two different worlds,there seems to the protagonist in The Catcher in the Rye the dichotomies between innocence and corruption,children and adults.While these dualisms are projected in the story,they are also deconstructed and the characterization of Holden clearly shows the instability of those dualisms.

  13. Responses to a Modified Visual Cliff by Pre-Walking Infants Born Preterm and at Term

    Science.gov (United States)

    Lin, Yuan-Shan; Reilly, Marie; Mercer, Vicki S.

    2010-01-01

    The purpose of this study was to examine, using a modified visual cliff apparatus, possible perceptual differences at crawling age between infants born preterm and infants born at term without documented visual or motor impairments. Sixteen infants born at term and 16 born preterm were encouraged to crawl to their caregivers on a modified visual…

  14. Cliff or Step? Posture-Specific Learning at the Edge of a Drop-Off

    Science.gov (United States)

    Kretch, Kari S.; Adolph, Karen E.

    2013-01-01

    Infants require locomotor experience to behave adaptively at a drop-off. However, different experimental paradigms (visual cliff and actual gaps and slopes) have generated conflicting findings regarding what infants learn and the specificity of their learning. An actual, adjustable drop-off apparatus was used to investigate whether learning to…

  15. Cliffs used as communal roosts by Andean condors protect the birds from weather and predators.

    Directory of Open Access Journals (Sweden)

    Sergio A Lambertucci

    Full Text Available The quality and availability of resources influence the geographical distribution of species. Social species need safe places to rest, meet, exchange information and obtain thermoregulatory benefits, but those places may also serve other important functions that have been overlooked in research. We use a large soaring bird that roosts communally in cliffs, the Andean condor (Vultur gryphus, as a model species to elucidate whether roost locations serve as a refuge from adverse weather conditions (climatic refuge hypothesis, CRH, and/or from predators or anthropogenic disturbances (threats refuge hypothesis, TRH. The CRH predicts that communal roosts will face in the opposite direction from where storms originate, and will be located in climatically stable, low precipitation areas. The TRH predicts that communal roosts will be large, poorly accessible cliffs, located far from human-made constructions. We surveyed cliffs used as communal roosts by condors in northwestern Patagonia, and compared them with alternative non-roosting cliffs to test these predictions at local and regional scales. We conclude that communal roosting places provide refuge against climate and disturbances such as, for instance, the threats of predators (including humans. Thus, it is not only the benefits gained from being aggregated per se, but the characteristics of the place selected for roosting that may both be essential for the survival of the species. This should be considered in management and conservation plans given the current scenario of global climate change and the increase in environmental disturbances.

  16. An experimental study of the effect of different onshore cliff angles on near shore hydrodynamics

    Science.gov (United States)

    Sim, S.; Xu, C.; Huang, Z.

    2013-12-01

    As a tsunami propagates towards the shore, they will shoal and then break. This will lead to an up rush of water. In scenarios where there are no distinct obstacles that affect the near shore coastal topography, this inundation process will not be halted and the water will travel to its farthest extent without any hindrance. As the water recedes, the return flow will be that of a shallow sheet flow. However, these expected hydrodynamic observations may not be recorded if there are significant alterations to the near shore topographical settings. In this study we investigated the effect of an onshore cliff on near shore hydrodynamics. A series of laboratory experiments were conducted in a wave flume to examine how different onshore cliff angles can affect the near shore hydrodynamics. Key parameters recorded were the run-up and inundation values. The recorded measurements showed that when the cliff angle is very steep, the flow depth in front of the cliff will be amplified significantly. This is evidenced by video recordings of the side profile of the wave flume. The video recording also showed a return plunging breaker wave which entrained air; this could imply that the near shore morphology could also be affected as sediment near shore can be entrained by this turbulence generated and then carried further offshore.

  17. Experimental infection of cliff swallows (Petrochelidon pyrrhonota) with varying doses of West Nile virus

    Science.gov (United States)

    Oesterle, P.T.; Nemeth, N.M.; VanDalen, Kaci K.; Sullivan, H.; Bentler, K.T.; Young, G.R.; McLean, R.G.; Clark, L.; Smeraski, C.; Hall, J.S.

    2009-01-01

    Cliff swallows (Petrochelidon pyrrhonota) were inoculated with differing doses of West Nile virus (WNV) to evaluate their potential role as reservoir hosts in nature. Swallows often nest in large colonies in habitats and months associated with high mosquito abundance and early WNV transmission in North America. Additionally, cliff swallow diet consists of insects, including mosquitoes, leading to an additional potential route of WNV infection. The average peak viremia titer among infected cliff swallows was 106.3 plaque-forming units (PFU)/mL serum and the reservoir competence index was 0.34. There was no correlation between dose and probability of becoming infected or viremia peak and duration. Oral shedding was detected from 2 to 14 days post-inoculation with an average peak titer of 1044 PFU/swab. These results suggest that cliff swallows are competent reservoir hosts of WNV and therefore, they may play a role in early seasonal amplification and maintenance of WNV. Copyright ?? 2009 by The American Society of Tropical Medicine and Hygiene.

  18. Rolling circle amplification of metazoan mitochondrialgenomes

    Energy Technology Data Exchange (ETDEWEB)

    Simison, W. Brian; Lindberg, D.R.; Boore, J.L.

    2005-07-31

    Here we report the successful use of rolling circle amplification (RCA) for the amplification of complete metazoan mt genomes to make a product that is amenable to high-throughput genome sequencing techniques. The benefits of RCA over PCR are many and with further development and refinement of RCA, the sequencing of organellar genomics will require far less time and effort than current long PCR approaches.

  19. Morphometric analysis of Willis circle arteries

    Directory of Open Access Journals (Sweden)

    Alma Voljevica

    2013-01-01

    Full Text Available Introduction: Willis arterial circle (circulus arteriosus cerebri Willisi is the most important part of the collateral circulatory system of the brain. It functions in normal and pathological situations such as valvular mechanism and thus allows optimal blood supply of all parts of the brain tissue, which reduces the risk of transient ischemic attack (TIA and stroke. The main pre-requisite for the normal function of the circle is its completeness and the lack of hypoplastic vessels. Materials and Methods: In this research, we used 100 angiograms of carotid system shown by serial angiography by Seldinger taken from the archives of the Department of Radiology, Clinical Center University of Sarajevo. For morphometric analysis of blood vessels, we used specially designed software program ELLIPSE (ViDiTo, Zoltan Tomoris, Kosice, Slovak Republic, tomori@saske.sk. In this way, it was possible to more easily store and analyze angiograms that were used for morphometric analysis. Results: In our study, larger diameters of blood vessels in Willis circle were observed in the younger subjects compared to older except the diameter of the internal carotid artery, which was about 0.2 to 0.3 mm larger in the older subjects. In both age groups among males, we recorded larger diameters of the internal carotid artery and segment before the circle of the posterior cerebral artery in relation to the female population, while the rear communicating artery in females was 0.1 mm wider in diameter compared to men in category of younger respondents.

  20. The Bakhtin Circle and Applied Linguistics

    Directory of Open Access Journals (Sweden)

    Newton Duarte Molon

    2012-11-01

    Full Text Available This article aims at presenting the relations between the theoretical formulations of the Bakhtin Circle and the current discussion on the scope of the so called Applied Linguistics (AL. In order to do that, we will briefly outline the history of AL, present the main conceptions of the Bakhtin Circle‟s thought, and build possible dialogues between the theoretical formulations of the Russian thinkers and the main issues of the current debate in Applied Linguistics.

  1. Cliff Collapse Hazard from Repeated Multicopter Uav Acquisitions: Return on Experience

    Science.gov (United States)

    Dewez, T. J. B.; Leroux, J.; Morelli, S.

    2016-06-01

    Cliff collapse poses a serious hazard to infrastructure and passers-by. Obtaining information such as magnitude-frequency relationship for a specific site is of great help to adapt appropriate mitigation measures. While it is possible to monitor hundreds-of-meter-long cliff sites with ground based techniques (e.g. lidar or photogrammetry), it is both time consuming and scientifically limiting to focus on short cliff sections. In the project SUAVE, we sought to investigate whether an octocopter UAV photogrammetric survey would perform sufficiently well in order to repeatedly survey cliff face geometry and derive rock fall inventories amenable to probabilistic rock fall hazard computation. An experiment was therefore run on a well-studied site of the chalk coast of Normandy, in Mesnil Val, along the English Channel (Northern France). Two campaigns were organized in January and June 2015 which surveyed about 60 ha of coastline, including the 80-m-high cliff face, the chalk platform at its foot, and the hinterland in a matter of 4 hours from start to finish. To conform with UAV regulations, the flight was flown in 3 legs for a total of about 30 minutes in the air. A total of 868 and 1106 photos were respectively shot with a Sony NEX 7 with fixed focal 16mm. Three lines of sight were combined: horizontal shots for cliff face imaging, 45°-oblique views to tie plateau/platform photos with cliff face images, and regular vertical shots. Photogrammetrically derived dense point clouds were produced with Agisoft Photoscan at ultra-high density (median density is 1 point every 1.7cm). Point cloud density proved a critical parameter to reproduce faithfully the chalk face's geometry. Tuning down the density parameter to "high" or "medium", though efficient from a computational point of view, generated artefacts along chalk bed edges (i.e. smoothing the sharp gradient) and ultimately creating ghost volumes when computing cloud to cloud differences. Yet, from a hazard point of

  2. CLIFF COLLAPSE HAZARD FROM REPEATED MULTICOPTER UAV ACQUISITIONS: RETURN ON EXPERIENCE

    Directory of Open Access Journals (Sweden)

    T. J. B. Dewez

    2016-06-01

    Full Text Available Cliff collapse poses a serious hazard to infrastructure and passers-by. Obtaining information such as magnitude-frequency relationship for a specific site is of great help to adapt appropriate mitigation measures. While it is possible to monitor hundreds-of-meter-long cliff sites with ground based techniques (e.g. lidar or photogrammetry, it is both time consuming and scientifically limiting to focus on short cliff sections. In the project SUAVE, we sought to investigate whether an octocopter UAV photogrammetric survey would perform sufficiently well in order to repeatedly survey cliff face geometry and derive rock fall inventories amenable to probabilistic rock fall hazard computation. An experiment was therefore run on a well-studied site of the chalk coast of Normandy, in Mesnil Val, along the English Channel (Northern France. Two campaigns were organized in January and June 2015 which surveyed about 60 ha of coastline, including the 80-m-high cliff face, the chalk platform at its foot, and the hinterland in a matter of 4 hours from start to finish. To conform with UAV regulations, the flight was flown in 3 legs for a total of about 30 minutes in the air. A total of 868 and 1106 photos were respectively shot with a Sony NEX 7 with fixed focal 16mm. Three lines of sight were combined: horizontal shots for cliff face imaging, 45°-oblique views to tie plateau/platform photos with cliff face images, and regular vertical shots. Photogrammetrically derived dense point clouds were produced with Agisoft Photoscan at ultra-high density (median density is 1 point every 1.7cm. Point cloud density proved a critical parameter to reproduce faithfully the chalk face’s geometry. Tuning down the density parameter to “high” or “medium”, though efficient from a computational point of view, generated artefacts along chalk bed edges (i.e. smoothing the sharp gradient and ultimately creating ghost volumes when computing cloud to cloud differences. Yet

  3. Sea-cliff erosion at Pacifica, California caused by 1997/98 El Niño storms

    Science.gov (United States)

    Snell, Charles B.; Lajoie, Kenneth R.; Medley, Edward W.

    2000-01-01

    Twelve homes were constructed in 1949 at the top of a sea cliff along Esplanade Drive in the City of Pacifica, located on the northern coast of San Mateo County, California. The rear yards of those properties were bounded by an approximately 20-meter (70-foot) high cliff that has retreated episodically at an average rate of 0.5 to 0.6 meter (1.5 to 2 feet) per year over the past 146 years. During the heavy storms of the 1997/1998 El Niño winter, a severe episode of cliff retreat undermined seven homes and threatened three others. All ten homes were condemned and demolished by the City of Pacifica. In this study we analyze geologic, tide, wave, rainfall and wind data in an attempt to determine the causes of this most recent erosion event. We identify the following possible contributory causes of the cliff retreat: 1) wave-induced undercutting of the cliff landward of an old revetment, 2) reduction in beach width over time, 3) reduction in cliff-face stability owing to infiltration from heavy rains, 4) erosion of the cliff face by groundwater piping, and 5) wind-induced erosion of loose dune sand at the top of the cliff. While these factors may explain the retreat of the cliff below the twelve homes along Esplanade Drive, the question remains as to why other geologically similar sites in the region were not severely eroded during the 1997/1998 El Niño winter.

  4. Detection of morphological changes in cliff face surrounding a waterfall using terrestrial laser scanning and unmanned aerial system

    Science.gov (United States)

    Hayakawa, Yuichi S.; Obanawa, Hiroyuki

    2015-04-01

    Waterfall or bedrock knickpoint appears as an erosional front in bedrock rivers forming deep v-shaped valley downstream. Following the rapid fluvial erosion of waterfall, rockfalls and gravita-tional collapses often occur in surrounding steep cliffs. Although morphological changes of such steep cliffs are sometimes visually observed, quantitative and precise measurements of their spatio-temporal distribution have been limited due to the difficulties in direct access to such cliffs if with classical measurement methods. However, for the clarification of geomorphological processes oc-curring in the cliffs, multi-temporal mapping of the cliff face at a high resolution is necessary. Re-mote sensing approaches are therefore suitable for the topographic measurements and detection of changes in such inaccessible cliffs. To achieve accurate topographic mapping of cliffs around a wa-terfall, here we perform multi-temporal terrestrial laser scanning (TLS), as well as structure-from-motion multi-view stereo (SfM-MVS) photogrammetry based on unmanned aerial system (UAS). The study site is Kegon Falls in central Japan, having a vertical drop of surface water from top of its overhanging cliff, as well as groundwater outflows from its lower portions. The bedrock is composed of alternate layers of andesite lava and conglomerates. Minor rockfalls in the cliffs are often ob-served by local people. The latest major rockfall occurred in 1986, causing ca. 8-m upstream propa-gation of the waterfall lip. This provides a good opportunity to examine the changes in the surround-ing cliffs following the waterfall recession. Multi-time point clouds were obtained by TLS measure-ment over years, and the three-dimensional changes of the rock surface were detected, uncovering the locus of small rockfalls and gully developments. Erosion seems particularly frequent in relatively weak the conglomerates layer, whereas small rockfalls seems to have occurred in the andesite layers. Also, shadows in the

  5. Inshore analyse of the morphostructural evolution of the coastal cliffs of Bessin, Basse-Normandie, France

    Science.gov (United States)

    Vioget, Alizée; Costa, Stéphane; Derron, Marc-Henri; Jaboyedoff, Michel; Maquaire, Olivier; Michoud, Clément

    2014-05-01

    The cliffs' retreat is a major issue for the management of coastal territories. Two coastal areas in "Calvados" and "Pays de Caux", French Normandy, are studied by the University of Caen for several years, and more recently assisted by the University of Lausanne. The studied section of the cliffs of Bessin is about 4.3 km long and lies between the World War II artillery batteries of Longues-sur-Mer and Arromanches-les-Bains. The site's lithology is mainly made of two formations: the limestones of Bessin that lie on top of the marls of Port. On the coastline, the cliff's height varies between 10 and 75 meters above sea level. The marl formation acts like an aquitard, as it is semi-impermeable. Therefore, more or less important water outflows are observable at the point of contact between the marls and the limestones. First, the study aims to create an up to date geomorphological map as well as a kinematic classification of the existing instabilities of the different cliff's profiles. This part is realized with on site field measurements. We observe several profiles depending on the type of cliff studied: sinking of limestone panels due to creeping marls at the base, overhang limestone formation, wave-cut notch, detachment, tilt, rotational slide, superficial separation etc. These several behaviours depend on the cliff's exposure to the Channel sea and weathering factors, morphology, presence of pebble beach etc. The coastline section is thus classified depending on the different morphological types observed, which influence the stability and erosion rates. Principal morphological types here are: overhang limestone formation near Cape Manvieux, creeping marls near le Chaos and graben near le Bouffay. Then, the cliffs' condition is compared to the diachronic analyse of the shoreline evolution supported by different photographic documents. This part of the study allows to refine the spatiotemporal occurrence of the different ground movements. However, cliffs

  6. Convex functions and the rolling circle criterion

    OpenAIRE

    1995-01-01

    Given 0≤R1≤R2≤∞, CVG(R1,R2) denotes the class of normalized convex functions f in the unit disc U, for which ∂f(U) satisfies a Blaschke Rolling Circles Criterion with radii R1 and R2. Necessary and sufficient conditions for R1=R2, growth and distortion theorems for CVG(R1,R2) and rotation theorem for the class of convex functions of bounded type, are found.

  7. Arabia: from craters to stone circles

    CERN Document Server

    Sparavigna, Amelia Carolina

    2010-01-01

    The Arabia Shield has a volcanic nature inside. A region of the Western Saudi Arabia is in fact covered with vast fields of lava known as harraat. These lands are spotted by many stone circles and other quite interesting archaeological remains of the Neolithic period, such as the "desert kites", the hunters used to guide the game across the harrah in some corrals. With Google Maps, we can observe both sceneries, the volcanic nature of the land and a portrait of Arabia during the Neolithic times.

  8. Estimation of pure qubits on circles

    CERN Document Server

    Braunstein, S L; Severini, S; Braunstein, Samuel L.; Ghosh, Sibasish; Severini, Simone

    2004-01-01

    Gisin and Popescu [PRL, 83, 432 (1999)] have shown that more information about their direction can be obtained from a pair of anti-parallel spins compared to a pair of parallel spins, where the first member of the pair (which we call the pointer member) can point equally along any direction in the Bloch sphere. They argued that this was due to the difference in dimensionality spanned by these two alphabets of states. Here we consider similar alphabets, but with the first spin restricted to a fixed small circle of the Bloch sphere. In this case, the dimensionality spanned by the anti-parallel versus parallel alphabet is now equal. However, the anti-parallel alphabet is found to still contain more information in general. We generalize this to having N parallel spins and M anti-parallel spins. When the pointer member is restricted to a small circle these alphabets again span spaces of equal dimension, yet in general, more directional information can be found for sets with smaller |N-M| for any fixed total number...

  9. Observations of debris flows at Chalk Cliffs, Colorado, USA: Part 2, changes in surface morphometry from terrestrial laser scanning in the summer of 2009

    Science.gov (United States)

    Staley, Dennis M.; Wasklewicz, Thad A.; Coe, Jeffrey A.; Kean, Jason W.; McCoy, Scott W.; Tucker, Greg E.

    2011-01-01

    High resolution topographic data that quantify changes in channel form caused by sequential debris flows in natural channels are rare at the reach scale. Terrestrial laser scanning (TLS) techniques are utilized to capture morphological changes brought about by a high-frequency of debris-flow events at Chalk Cliffs, Colorado. The purpose of this paper is to compare and contrast the topographic response of a natural channel to the documented debris-flow events. TLS survey data allowed for the generation of high-resolution (2-cm) digital terrain models (DTM) of the channel. A robust network of twelve permanent control points permitted repeat scanning sessions that provided multiple DTM to evaluate fine-scale topographic change associated with three debris-flow events. Difference surfaces from the DTM permit the interpretations of spatial variations in channel morphometry and net volume of material deposited and eroded within and between a series of channel reaches. Each channel reach experienced erosion, deposition, and both net volumetric gains and losses were measured. Analysis of potential relationships between erosion and deposition magnitudes yielded no strong correlations with measures of channel-reach morphometry, suggesting that channel reach-specific predictions of potential erosion or deposition locations or rates cannot be adequately derived from statistical analyses of pre-event channel-reach morphometry.

  10. Comparative simulations of the 2011 Tohoku tsunami with MOST and Cliffs

    CERN Document Server

    Tolkova, Elena

    2014-01-01

    Wet-dry interface which appreciably increases accuracy of tsunami simulations with the MOST model (Method of Splitting Tsunamis, adapted by the NOAA for tsunami forecasting operations) is highlighted here with a few comparative simulations. The new solution, termed Cliffs, exceeds all MOST versions in accuracy of computing later waves. This is demonstrated with simulation of the Tohoku-2011 tsunami to Monterey Bay, CA, and into fiords, bays, and inlets of southeastern Alaska, followed by comparison with tide gage records.

  11. Cliff swallows Petrochelidon pyrrhonota as bioindicators of environmental mercury, Cache Creek Watershed, California

    Science.gov (United States)

    Hothem, Roger L.; Trejo, Bonnie S.; Bauer, Marissa L.; Crayon, John J.

    2008-01-01

    To evaluate mercury (Hg) and other element exposure in cliff swallows (Petrochelidon pyrrhonota), eggs were collected from 16 sites within the mining-impacted Cache Creek watershed, Colusa, Lake, and Yolo counties, California, USA, in 1997-1998. Nestlings were collected from seven sites in 1998. Geometric mean total Hg (THg) concentrations ranged from 0.013 to 0.208 ??g/g wet weight (ww) in cliff swallow eggs and from 0.047 to 0.347 ??g/g ww in nestlings. Mercury detected in eggs generally followed the spatial distribution of Hg in the watershed based on proximity to both anthropogenic and natural sources. Mean Hg concentrations in samples of eggs and nestlings collected from sites near Hg sources were up to five and seven times higher, respectively, than in samples from reference sites within the watershed. Concentrations of other detected elements, including aluminum, beryllium, boron, calcium, manganese, strontium, and vanadium, were more frequently elevated at sites near Hg sources. Overall, Hg concentrations in eggs from Cache Creek were lower than those reported in eggs of tree swallows (Tachycineta bicolor) from highly contaminated locations in North America. Total Hg concentrations were lower in all Cache Creek egg samples than adverse effects levels established for other species. Total Hg concentrations in bullfrogs (Rana catesbeiana) and foothill yellow-legged frogs (Rana boylii) collected from 10 of the study sites were both positively correlated with THg concentrations in cliff swallow eggs. Our data suggest that cliff swallows are reliable bioindicators of environmental Hg. ?? Springer Science+Business Media, LLC 2007.

  12. Observations of historical sea cliff retreat rates exceed long-term estimates derived from cosmogenic 10Be

    Science.gov (United States)

    Hurst, Martin D.; Rood, Dylan H.; Ellis, Michael A.; Anderson, Robert S.

    2015-04-01

    Historical observation of coastal retreat are limited to relatively short timescales (change may be accelerated in the face of anticipated stormier climates and rising sea level, yet there is little knowledge of rates of coastal change prior to the relatively brief historical records. In order to make predictions about potential future coastal change it is important to establish baseline conditions averaged over longer time periods. Here we present analysis of sea cliff retreat throughout the Holocene averaged for chalk cliffs in south-east England using cosmogenic isotopes. We determine long-term rates of sea cliff erosion from 10Be measured from in-situ flint samples collected from three transects across coastal platforms in East Sussex. A numerical model of 10Be accumulation on an evolving coastal profile allows estimation of cliff retreat rate during the Holocene. The model accounts for variation in 10Be accumulation with tides and sea-level rise, and takes into account platform downwear and topographic shielding by adjacent cliffs. We find that cliff retreat rates during the Holocene were significantly slower (2-6 cm yr-1) than those derived from recent historical observations (15-25 cm yr-1). Modelled accumulation of 10Be requires retreat rates that increase rapidly in recent times, potentially reflecting human modification of the coastal sediment budget through construction of sea defences, flood defenses and aggregate extraction. Therefore knowledge of past human activity at the coastline may be important in anticipating future rates of coastal retreat.

  13. Reconstructing 3D coastal cliffs from airborne oblique photographs without ground control points

    Science.gov (United States)

    Dewez, T. J. B.

    2014-05-01

    Coastal cliff collapse hazard assessment requires measuring cliff face topography at regular intervals. Terrestrial laser scanner techniques have proven useful so far but are expensive to use either through purchasing the equipment or through survey subcontracting. In addition, terrestrial laser surveys take time which is sometimes incompatible with the time during with the beach is accessible at low-tide. By comparison, structure from motion techniques (SFM) are much less costly to implement, and if airborne, acquisition of several kilometers of coastline can be done in a matter of minutes. In this paper, the potential of GPS-tagged oblique airborne photographs and SFM techniques is examined to reconstruct chalk cliff dense 3D point clouds without Ground Control Points (GCP). The focus is put on comparing the relative 3D point of views reconstructed by Visual SFM with their synchronous Solmeta Geotagger Pro2 GPS locations using robust estimators. With a set of 568 oblique photos, shot from the open door of an airplane with a triplet of synchronized Nikon D7000, GPS and SFM-determined view point coordinates converge to X: ±31.5 m; Y: ±39.7 m; Z: ±13.0 m (LE66). Uncertainty in GPS position affects the model scale, angular attitude of the reference frame (the shoreline ends up tilted by 2°) and absolute positioning. Ground Control Points cannot be avoided to orient such models.

  14. Neurodynamics in Randomly Coupled Circle Maps

    Science.gov (United States)

    Matsuno, Tetsuya; Toko, Kiyoshi; Yamafuji, Kaoru

    1996-05-01

    The dynamics of retrieval processes in a system composed of coupled circle maps is studied by means of a statistical method and numerical simulations. Phase patterns are embedded in coupling parameters so that the system may work as an associative memory system. A parameter, which is an amplification factor multiplied to all the coupling strengths, is introduced for investigating the effect of the strength of the coupling nonlinearity on the behavior of the system concerned. The statistical method provides a set of time evolution equations representing the macroscopic behavior. It is found that the storage capacity is considerably enhanced by the introduced amplification factor. It is also shown that the system exhibits macroscopic chaotic oscillations when the strength of the coupling is sufficiently large. Moreover, the clustering is observed, as in other types of the globally coupled nonlinear systems.

  15. Fast transport optimization on the circle

    CERN Document Server

    Delon, Julie; Sobolevskii, Andrei

    2009-01-01

    Consider the problem of optimally matching two measures on the circle, or equivalently two periodic measures on the real line, and suppose the cost of matching two points satisfies the Monge condition. We introduce a notion of locally optimal transport plan, motivated by the weak KAM (Aubry-Mather) theory, and show that all locally optimal transport plans are conjugate to shifts. This theory is applied to a transportation problem arising in image processing: for two sets of point masses, both of which have the same total mass, find an optimal transport plan with respect to a given cost function that satisfies the Monge condition. For the case of N real-valued point masses we present an O(N log epsilon) algorithm that approximates the optimal cost within epsilon; when all masses are integer multiples of 1/M, the algorithm gives an exact solution in O(N log M) operations.

  16. Controlled Microwave Heating Accelerates Rolling Circle Amplification.

    Science.gov (United States)

    Yoshimura, Takeo; Suzuki, Takamasa; Mineki, Shigeru; Ohuchi, Shokichi

    2015-01-01

    Rolling circle amplification (RCA) generates single-stranded DNAs or RNA, and the diverse applications of this isothermal technique range from the sensitive detection of nucleic acids to analysis of single nucleotide polymorphisms. Microwave chemistry is widely applied to increase reaction rate as well as product yield and purity. The objectives of the present research were to apply microwave heating to RCA and indicate factors that contribute to the microwave selective heating effect. The microwave reaction temperature was strictly controlled using a microwave applicator optimized for enzymatic-scale reactions. Here, we showed that microwave-assisted RCA reactions catalyzed by either of the four thermostable DNA polymerases were accelerated over 4-folds compared with conventional RCA. Furthermore, the temperatures of the individual buffer components were specifically influenced by microwave heating. We concluded that microwave heating accelerated isothermal RCA of DNA because of the differential heating mechanisms of microwaves on the temperatures of reaction components, although the overall reaction temperatures were the same.

  17. From grazing marks to collapsed cliffs - intertidal bioerosion on all scales

    Science.gov (United States)

    Kázmér, Miklós; Taboroši, Danko; Hsieh, Meng-Long; Shafeea Leman, Mohd; Aziz Ali, Che; Roslan Mohamed, Kamal; Choowong, Montri

    2014-05-01

    Rocky shores - particularly in limestone areas of tropical, subtropical, and some temperate regions - are subject to intense bioerosion. Detailed field studies along the Gulf of Siam and the Andaman coast of Thailand, Langkawi Islands of Malaysia, southern Java and Bali in Indonesia, Palau Islands, and Okinawa revealed the presence of rich populations of bioeroding organisms in the intertidal zone. Molluscs capable of damaging rock (the chiton Acanthopleura, limpets, and whelks) leave grazing traces as they feed on bacterial and algal biofilms and chasmolithic and endolithic microorganisms. Boring sponges (Entobia), bivalves (Gastrochaenolites and others), boring sipunculid worms (Caulostrepsis), and sea urchins (Echinometra) drill deeper to hide from predators beneath the rock surface. Individually, members of these taxa leave marks ranging from sub-millimetre to the metre scale, but collectively, their erosion creates marine notches, several-metres-deep features extending between low and high tide marks. When cliffs overhanging these notches collapse, landscape-scale scars are left behind. The various bioeroders display a clear vertical zonation between low and high tide. These are dictated by environmental stress, food availability, competition, and predation. Typical inhabitants of present-day zones include - from top to bottom - littorinid snails, patellid limpets, chitons, boring bivalves, and boring sea urchins. Each organism leaves a characteristic mark in the bedrock. Trace fossils found in the 'wrong place' - either too high or too low compared to the present-day occurrence of the animals - suggest changes in relative sea level. Similarly, sea level changes are suggested by the presence of compound markings produced through overprinting by organisms that live in different ecological zones. Preservation and obliteration of traces depends on the rates of sea level change and coastal denudation. Morphology of bioerosional markings and their vertical zonation

  18. Sources of Sulfate Found in Mounds and Lakes at the Lewis Cliffs Ice Tongue, Transantarctic

    Science.gov (United States)

    Socki, Richard; Sun, Tao; Harvey, Ralph P.; Bish, David L.; Tonui, Eric; Bao, Huiming; Niles, Paul B.

    2012-01-01

    Massive but highly localized Na-sulfate mounds (mirabilite, Na2SO4.10H2O) have been found at the terminal moraine of the Lewis Cliffs Ice Tongue (LCIT), Antarctica. (Sigma)34S and (Sigma)18O values of LCIT mirabilite range from +48.8 to +49.3% (CDT), and -16.6 to -17.1% (V-SMOW), respectively, while (Delta)17O average -0.37% (V-SMOW). LCIT mirabilite mounds are isotopically different from other mirabilite mounds found in coastal regions of Antarctica, which have isotope values close to seawater compositions. (Sigma)18O and (Delta)17O values suggest the incorporation of isotopically light glacial water. Data point to initial sulfate formation in an anoxic water body, either as a stratified anoxic deep lake on the surface, a sub-glacial water reservoir, or a sub-glacial lake. Several surface lakes of varying size are also present within this region of the LCIT, and in some cases are adjacent to the mirabilite mounds. O and D isotope compositions of surface lakes confirm they are derived from a mixture of glacial ice and snow that underwent moderate evaporation. (Sigma)18O and (Sigma)D (V-SMOW) values of snow, ice, and lake water range from -64.2 to -29.7%, and -456.0 to -231.7%, respectively. However, the isotope chemistry of these surface lakes is extremely different from the mounds. Dissolved SO4-2 (Sigma)34S and (Sigma)18O values range from +12.0 to +20.0% and -12.8 to -22.2% (the most negative (Sigma)18O of terrestrial sulfate ever reported), respectively, with sulfate (Delta)17O ranging from +0.93 to 2.24%. Ion chromatography data show that lake water is fresh to brackish in origin, with TDS less than 1500 ppm, and sulfate concentration less than 431 ppm. Isotope and chemical data suggest that these lakes are unlikely the source of the mirabilite mounds. We suggest that lake water sulfate is potentially composed of a mixture of atmospheric sulfate and minor components of sulfate of weathering origin, much like the sulfate in the polar plateau soils of the Mc

  19. The Vienna circles: cultivating economic knowledge outside academia

    NARCIS (Netherlands)

    E. Dekker (Erwin)

    2014-01-01

    markdownabstract__Abstract__ This article examines the intellectual scenery of interwar Vienna. It argues that its central institution was not academia, but rather the circles (‘Kreise’). The prominence of these circles can partly account for the creative outburst in the social sciences in interwar

  20. DNA circles with cruciforms from Isospora (Toxoplasma) gondii

    NARCIS (Netherlands)

    Weijers, P.J.; Borst, P.; Overdulve, J.P.; Fase-Fowler, F.; Berg, Marlene van den

    1984-01-01

    We have isolated a closed circular duplex DNA fraction from the unicellular parasite Isospora (Toxoplasma) gondii and examined the purified DNA by electron microscopy. A major part of this circular DNA consists of 12-μm circles containing a cruciform with 0.5-μm tails. We also found 23-μm circles wi

  1. Integrating Literature Circles into a Cotaught Inclusive Classroom

    Science.gov (United States)

    Whittaker, Catharine R.

    2012-01-01

    Literature circles or book clubs are small, heterogeneous groups of students who have chosen to read and discuss the same book together. The research on literature circles suggests that they hold great promise for increasing students' enjoyment of reading and honing their literacy skills. When evidence-based strategies are embedded into a…

  2. Locating a general minisum 'circle' on a plane

    DEFF Research Database (Denmark)

    Brimberg, Jack; Juel, Henrik; Körner, Mark-Christoph

    2011-01-01

    We approximate a set of given points in the plane by the boundary of a convex and symmetric set which is the unit circle of some norm. This generalizes previous work on the subject which considers Euclidean circles only. More precisely, we examine the problem of locating and scaling the unit circ...

  3. Locating a circle on the plane using the minimax criterion

    DEFF Research Database (Denmark)

    Brimberg, Jack; Juel, Henrik; Schöbel, Anita

    2009-01-01

    We consider the problem of locating a circle with respect to existing facilities on the plane, such that the largest weighted distance between the circumference of the circle and the facilities is minimized. The problem properties are analyzed, and a solution procedure proposed...

  4. Geometric fit of a point set by generalized circles

    DEFF Research Database (Denmark)

    Körner, Mark-Christopher; Brimberg, Jack; Juel, Henrik;

    2010-01-01

    In our paper we approximate a set of given points by a general circle. More precisely, given two norms k 1 and k 2 and a set of points in the plane, we consider the problem of locating and scaling the unit circle of norm k 1 such that the sum of weighted distances between the circumference of the...

  5. An Effective Time and Management Strategy in Quality Circles.

    Science.gov (United States)

    Halverson, Don E.

    Contending that participation in quality circles enhances effective time management by school administrators and teachers, this guide provides both a theoretical briefing and practical recommendations for better time management. A pre- posttest prefaces a review of basic concepts of quality circles with reference to the work of Abraham Maslow,…

  6. Cliff stability assessment using electrical resistivity tomography at the historic WWII D-Day invasion site, Pointe du Hoc, France

    Science.gov (United States)

    Everett, M. E.; Udphuay, S.; Warden, R.

    2007-05-01

    The 1944 D-Day invasion site at Pointe du Hoc, Normandy, France is an important WWII battlefield and cultural resource but is at risk from chalk cliff collapse. The American Battle Monuments Commission tasked us to evaluate the geohazard to the observation post and other cliff-side buildings of historical significance. Geophysical multi-electrode resistivity profiling is used to study cliff stability and the condition of the observation- post foundations. Preliminary 2-D geological interpretations are provided of individual profiles. The copious steel, concrete and void spaces at the site renders hydrogeological interpretation challenging but tractable. The cliff face appears to be relatively intact and well-drained. Several routes taken by groundwater into fractures within the chalk were identified mainly on the western side of the site. The eastern side is drier and somewhat sheltered from the Atlantic storms but may contain large void spaces that could efficiently transmit groundwater flow during heavy precipitation events, thereby imperiling the major antiaircraft gun emplacement occupied by Col. Rudder in the early days of the Allied invasion. The forward German observation post perched close to the sea stack, which now hosts the U.S. Ranger memorial, may be moving with the soil and not securely anchored to bedrock. A complex failure mechanism is identified as a combination of groundwater dissolution of the fractured chalk and sea wave attack at the cliff base.

  7. Brief communication"Estimating rockfall frequency in a mountain limestone cliff using terrestrial laser scanner"

    Directory of Open Access Journals (Sweden)

    A. Guerin

    2014-01-01

    Full Text Available Using terrestrial laser scanner, 344 rockfalls larger than 0.05 m3 have been detected for a period of 1180 days, in a thinly bedded limestone cliff of width 750 m and height 200 m. The complementary cumulative distribution of the rockfall volume is well fitted by a power law, with an exponent b of 0.75 ± 0.04. In order to compare the rockfall frequencies in different geological contexts, a rockfall activity parameter has been defined, which is the number of rockfalls larger than 1 m3, which occur per century and per hm2.

  8. Androgen circle of polycystic ovary syndrome.

    Science.gov (United States)

    Homburg, Roy

    2009-07-01

    Although the aetiology of polycystic ovary syndrome (PCOS) is still not known and the search for causative genes is proving elusive, it is generally agreed that hyperandrogenism is at the heart of the syndrome. Here, it is proposed that excess androgens are the root cause of PCOS starting from their influence on the female fetus in programming gene expression, producing the characteristic signs and symptoms which are then exacerbated by a propagation of excess ovarian androgen production from multiple small follicles, anovulation and insulin resistance in the reproductive life-span, thus setting up a vicious perpetual circle of androgen excess. This opinion paper, rather than being a full-scale review, is intentionally biased in support of this hypothesis that androgen excess is the 'root of all evil' in PCOS; in the hope that its acceptance could lead to more direct treatment of the syndrome in all its facets rather than the symptomatic treatment of side effects of androgen excess that we are addressing today.

  9. Inhomogeneous field theory inside the arctic circle

    Science.gov (United States)

    Allegra, Nicolas; Dubail, Jérôme; Stéphan, Jean-Marie; Viti, Jacopo

    2016-05-01

    Motivated by quantum quenches in spin chains, a one-dimensional toy-model of fermionic particles evolving in imaginary-time from a domain-wall initial state is solved. The main interest of this toy-model is that it exhibits the arctic circle phenomenon, namely a spatial phase separation between a critically fluctuating region and a frozen region. Large-scale correlations inside the critical region are expressed in terms of correlators in a (euclidean) two-dimensional massless Dirac field theory. It is observed that this theory is inhomogenous: the metric is position-dependent, so it is in fact a Dirac theory in curved space. The technique used to solve the toy-model is then extended to deal with the transfer matrices of other models: dimers on the honeycomb and square lattice, and the six-vertex model at the free fermion point (Δ =0 ). In all cases, explicit expressions are given for the long-range correlations in the critical region, as well as for the underlying Dirac action. Although the setup developed here is heavily based on fermionic observables, the results can be translated into the language of height configurations and of the gaussian free field, via bosonization. Correlations close to the phase boundary and the generic appearance of Airy processes in all these models are also briefly revisited in the appendix.

  10. Geršgorin and his circles

    CERN Document Server

    Varga, Richard S

    2004-01-01

    TheGer? sgorin CircleTheorem, averywell-known resultin linear algebra today, stems from the paper of S. Ger? sgorin in 1931 (which is reproduced in AppendixD)where,givenanarbitraryn×ncomplexmatrix,easyarithmetic operationsontheentriesofthematrixproducendisks,inthecomplexplane, whose union contains all eigenvalues of the given matrix. The beauty and simplicity of Ger? sgorin’s Theorem has undoubtedly inspired further research in this area, resulting in hundreds of papers in which the name “Ger? sgorin” appears. The goal of this book is to give a careful and up-to-date treatment of various aspects of this topic. The author ?rst learned of Ger? sgorin’s results from friendly conversations with Olga Taussky-Todd and John Todd, which inspired me to work in this area.Olgawasclearlypassionateaboutlinearalgebraandmatrixtheory,and her path-?nding results in these areas were like a magnet to many, including this author! It is the author’s hope that the results, presented here on topics related to Ger? sgorin...

  11. Yang-Lee Circle Theorem for an Antiferromagnetic Heisenberg Ladder

    Institute of Scientific and Technical Information of China (English)

    王先智

    2001-01-01

    The Yang-Lee zeros of an antiferromagnetic Heisenberg ladder model are determined. It is found that if J4≤0 Yang-Lee zeros are located on the unit circle and on the negative real axis in the complex activity plane. In particular, if J4≤0 and 2J2≥J4, Yang-Lee zeros are located on the unit circle and the Yang-Lee circle theorem is valid. If J4 > 0, Yang-Lee zeros are located on some complicated curves.

  12. Design and Calculation of the Resistance Circles for Wooden Barrels

    Directory of Open Access Journals (Sweden)

    Adriana FOTIN

    2011-03-01

    Full Text Available The aim of this paper is to present a design methodology for the circles of wooden barrels, usingappropriate strength calculations, so as to provide tightness while maintaining the integrity of the woodenmaterial embedded in the barrel structure, in the jacket and bottom staves, respectively.Based on these calculations, the circle dimensions (length, width and thickness can be defined,depending on the barrel type (for transport or storage and their relation to the barrel bottoms.Defining the dimensional characteristics of the circles is mandatory, as these are safety elements in thebarrel operation.

  13. Processes and rate of retreat of the clay and sandstone sea cliffs of the northern Boulonnais (France)

    Science.gov (United States)

    Pierre, Guillaume

    2006-01-01

    Retreat of the clay and sandstone cliffs of the northern Boulonnais (France) has been quantified using stereophotogrammetry. The low retreat rate of this coastal strip — 0.08 m/yr between 1939 and 2003 — is far less than that encountered on chalk and clay-chalk cliffs of either side of the Channel, and even less than a previous estimate of 0.17 m/yr regularly quoted in management studies. The retreat rate is closely related to shore platform morphology and dynamics. The shore platform presents 1) a steeply sloping ramp due to the accumulation of flat calcareous megaclasts that reduce marine erosion; 2) upstanding bare platform surfaces, related to tectonic deformation; and 3) thick platform-beaches trapped in troughs. In all three cases, the reflective behaviour of the nearshore protects the cliff foot from the incoming waves. Two critical eroding segments are the result of changes in the platform sedimentary budget. Around Cran Poulet, and between Plage de la Sirène and Pointe de la Courte Dune, the retreat rate is up to 0.25 and 0.15 m/yr, respectively. At Cran Poulet, recession has been facilitated by the extraction of pebble for more than half a century, whereas erosion of the beach at la Sirène is probably linked to severe erosion of the coastline in the adjacent Wissant Bay. Mass movements on the cliff face are essentially shallow-seated translational slides along with small debris falls and mudflows. The instability of the Argiles de Châtillon is greatly diminished by their sandy and silty texture and by the presence of interstratified solid shelly limestone beds that allow steep slopes to develop in rather weak material. The 'vertical erosion antecedent' is the erosional mode of the cliff, and its reduced efficiency explains the slow recession of the cliff. This study will help to determine the long term evolution of the Boulonnais coast.

  14. Molecular Phylogeny of the Cliff Ferns (Woodsiaceae: Polypodiales) with a Proposed Infrageneric Classification.

    Science.gov (United States)

    Shao, Yizhen; Wei, Ran; Zhang, Xianchun; Xiang, Qiaoping

    2015-01-01

    The cliff fern family Woodsiaceae has experienced frequent taxonomic changes at the familial and generic ranks since its establishment. The bulk of its species were placed in Woodsia, while Cheilanthopsis, Hymenocystis, Physematium, and Protowoodsia are segregates recognized by some authors. Phylogenetic relationships among the genera of Woodsiaceae remain unclear because of the extreme morphological diversity and inadequate taxon sampling in phylogenetic studies to date. In this study, we carry out comprehensive phylogenetic analyses of Woodsiaceae using molecular evidence from four chloroplast DNA markers (atpA, matK, rbcL and trnL-F) and covering over half the currently recognized species. Our results show three main clades in Woodsiaceae corresponding to Physematium (clade I), Cheilanthopsis-Protowoodsia (clade II) and Woodsia s.s. (clade III). In the interest of preserving monophyly and taxonomic stability, a broadly defined Woodsia including the other segregates is proposed, which is characterized by the distinctive indument and inferior indusia. Therefore, we present a new subgeneric classification of the redefined Woodsia based on phylogenetic and ancestral state reconstructions to better reflect the morphological variation, geographic distribution pattern, and evolutionary history of the genus. Our analyses of the cytological character evolution support multiple aneuploidy events that have resulted in the reduction of chromosome base number from 41 to 33, 37, 38, 39 and 40 during the evolutionary history of the cliff ferns.

  15. Molecular Phylogeny of the Cliff Ferns (Woodsiaceae: Polypodiales with a Proposed Infrageneric Classification.

    Directory of Open Access Journals (Sweden)

    Yizhen Shao

    Full Text Available The cliff fern family Woodsiaceae has experienced frequent taxonomic changes at the familial and generic ranks since its establishment. The bulk of its species were placed in Woodsia, while Cheilanthopsis, Hymenocystis, Physematium, and Protowoodsia are segregates recognized by some authors. Phylogenetic relationships among the genera of Woodsiaceae remain unclear because of the extreme morphological diversity and inadequate taxon sampling in phylogenetic studies to date. In this study, we carry out comprehensive phylogenetic analyses of Woodsiaceae using molecular evidence from four chloroplast DNA markers (atpA, matK, rbcL and trnL-F and covering over half the currently recognized species. Our results show three main clades in Woodsiaceae corresponding to Physematium (clade I, Cheilanthopsis-Protowoodsia (clade II and Woodsia s.s. (clade III. In the interest of preserving monophyly and taxonomic stability, a broadly defined Woodsia including the other segregates is proposed, which is characterized by the distinctive indument and inferior indusia. Therefore, we present a new subgeneric classification of the redefined Woodsia based on phylogenetic and ancestral state reconstructions to better reflect the morphological variation, geographic distribution pattern, and evolutionary history of the genus. Our analyses of the cytological character evolution support multiple aneuploidy events that have resulted in the reduction of chromosome base number from 41 to 33, 37, 38, 39 and 40 during the evolutionary history of the cliff ferns.

  16. Bounded Gain of Energy on the Breathing Circle Billiard

    CERN Document Server

    Oliffson-Kamphorst, S; Kamphorst, Sylvie Oliffson; Carvalho, Sonia Pinto de

    1998-01-01

    The Breathing Circle is a 2-dimensional generalization of the Fermi Accelerator. It is shown that the billiard map associated to this model has invariant curves in phase space, implying that any particle will have bounded gain of energy.

  17. The Blaschke conjecture and great circle fibrations of spheres

    OpenAIRE

    2001-01-01

    We construct an explicit diffeomorphism taking any fibration of a sphere by great circles into the Hopf fibration, using elementary geometry--indeed the diffeomorphism is a local (differential) invariant, algebraic in derivatives.

  18. Parhelic-like circle from light scattering in Plateau borders

    Energy Technology Data Exchange (ETDEWEB)

    Tufaile, A., E-mail: tufaile@usp.br; Tufaile, A.P.B.

    2015-03-06

    We are reporting a new simple optical element to generate halos. We have observed interesting patterns of light scattering in Plateau borders in foams. In analogy to the atmospheric phenomena known as parhelic circle, sun dogs, and sun pillars, we have named the features of the patterns observed as parlaseric circle, laser dogs, and laser pillars. The triangular symmetry of the Plateau borders is analogous to the hexagonal symmetry of ice crystals which produce these atmospheric phenomena. Working with one Plateau border at a time, we have observed wave optics phenomena that are not perceived in the atmospheric phenomena, such as diffraction and interference. - Highlights: • We obtained halo formation from light scattering in a Plateau border using an experiment. • We explained halo formation using geometrical theory of diffraction. • An optical element based on a Plateau border is proposed. • We compared some aspects of the parhelic circle with the parlaseric circle.

  19. Optimal impulsive ellipse-to-circle coplanar rendezvous

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The problem of ellipse-to-circle coplanar rendezvous with chaser spacecraft in low eccentricity was investigated in this paper.With reference frame established in the centroid of the target spacecraft,the process of ellipse-to-circle coplanar rendezvous was described by the relative equations based on cy-lindrical reference frame,and then the solutions and distributions of optimal rendezvous models of a kind of close ellipse-to-circle coplanar rendezvous were provided.The simulation results showed that the guidance law based on the optimal rendezvous model in this research has good performance,and that the distributions of optimal rendezvous models of ellipse-to-circle coplanar rendezvous with the chaser spacecraft in low eccentricity are similar,albeit with slight difference,to those of rendezvous between close circular orbits.The work in this paper is a useful extension to Prussing’s optimal ren-dezvous theory between close circular orbits.

  20. The Euler Line and Nine-Point-Circle Theorems.

    Science.gov (United States)

    Eccles, Frank M.

    1999-01-01

    Introduces the Euler line theorem and the nine-point-circle theorem which emphasize transformations and the power of functions in a geometric concept. Presents definitions and proofs of theorems. (ASK)

  1. Circle of Life——Symbolism in The Winter's Tale

    Institute of Scientific and Technical Information of China (English)

    李潇雨

    2007-01-01

    This essay tries to illustrate Winter's Tale's symbolic meaning about human life.It draws conclusion that Shakespeare's plan is to combine the natural rule of seasonal cycle with the life circle of human world.

  2. Vascular Plant and Vertebrate Inventory of Gila Cliff Dwellings National Monument

    Science.gov (United States)

    Powell, Brian F.; Albrecht, Eric W.; Halvorson, William L.; Schmidt, Cecilia A.; Docherty, Kathleen; Anning, Pamela

    2006-01-01

    Executive Summary This report summarizes the results of the first comprehensive biological inventory of Gila Cliff Dwellings National Monument (NM) in western New Mexico. This project was part of a larger effort to inventory plants and vertebrates in eight National Park Service units in Arizona and New Mexico. Our surveys address many of the objectives that were set forth in the monument's natural resource management plan almost 20 years ago, but until this effort, those goals were never accomplished. From 2001 to 2003 we surveyed for vascular plants and vertebrates (amphibians, reptiles, birds, and mammals) at Gila Cliff Dwellings NM to document presence of species within the boundaries of the monument. For all taxonomic groups that we studied, we collected 'incidental' sightings on U.S. Forest Service lands adjacent to the monument, and in a few cases we did formal surveys on those lands. Because we used repeatable study designs and standardized field techniques, these inventories can serve as the first step in a biological monitoring program for Gila Cliff Dwellings NM and surrounding lands. We recorded 552 species at Gila Cliff Dwellings NM and the surrounding lands (Table 1). We found no non-native species of reptiles, birds, or mammals, one non-native amphibian (American bullfrog), and 33 non-native plants. Particularly on lands adjacent to the monument we found that the American bullfrog was very abundant, which is a cause for significant management concern. Species of non-native plants that are of management concern include red brome, bufflegrass, and cheatgrass. For a park unit of its size and geographic location, we found the plant and vertebrate communities to be fairly diverse; for each taxonomic group we found representative species from a wide range of taxonomic orders and/or families. The monument's geographic location, with influences from the Rocky Mountain, Chihuahuan Desert, and Madrean ecological provinces, plays an important role in determining

  3. Biology coming full circle: joining the whole and the parts.

    Science.gov (United States)

    Wikswo, John P; Porter, Andrew P

    2015-01-01

    The new cover of Experimental Biology and Medicine features the hermeneutic circle of biology, a concept we have adapted from the hermeneutic principle that one understands the whole only in terms of each part and the parts only in terms of the whole. Our hermeneutic circle summarizes the course of experimental biology through 2500 years of the achievements of reductionist research (understanding the parts), which culminates in our ability to rapidly sequence the genome. Rather than returning along the same path in a constructionist approach that simply builds upon this knowledge, but in reverse, an alternative is to close the circle with synthetic constructions that seek to integrate the full complexity of biological and physiological systems (understanding the whole), of which organs-on-chips are one example. This closing of the circle cannot be a comprehensively accurate representation of biology, but it can be a synthetic one that effectively defines particular biological subsystems. The illustration of the hermeneutic circle of biology is also intended to suggest both the multiple cycles that may be required to reach such a synthesis and the expansion of the circle in an outward spiral as knowledge increases. Our commentary explains the symbolism of the new cover in a philosophical and scientific discussion.

  4. Contribution to the study of the geographical distribution of Pyrenean funerary stone circles (baratze, cromlech in the western Pyrenees

    Directory of Open Access Journals (Sweden)

    Jose Miguel EDESO FITO

    2016-07-01

    Full Text Available ‘Baratze’ or Pyrenean funerary stone circles, also known as Pyrenean cromlech, are funerary cremation monuments constructed between the Late Bronze Age and the beginning of the Roman period. These monuments consist of small circles, which consist of isolated standing stone blocks that enclose a central funerary deposit. The densest geographical distribution of Pyrenean funerary stone circles is located east of the Leizaran river and the lower basin of the Oria river up to approximately Andorra. Pyrenean cromlechs are located across mountain chains and occasionally share space with other funerary monuments constructed between the Middle Neolithic period and the Bronze Age –dolmens and cists–, whereas in other locations, cromlechs appear to be established in previously unoccupied mountain zones in an approximately continuous fashion by groups of farmers. The discovery of some Pyrenean circles in Ondarre and Beaskin (Sierra de Aralar, away from the nuclear zone and in a space continuously exploited since the Neolithic period, as indicated by the presence of other funerary monuments –dolmens and cists–, generates new questions regarding their distribution and the reasons for distinct densities of these rituals in some areas of the nuclear zone. Therefore, we propose different explanatory hypotheses, adapted to the distinct circumstances, as lithology, history, etc.

  5. Three Concentric Circles: Young Chinese English Learners' Perceptions of Purposeful Audiences

    Science.gov (United States)

    Liu, Jack Jinghui

    2015-01-01

    English learners have more access to communicate with different purposeful audiences across the Three Concentric Circles of English (Kachu, 1985): the Inner Circle, the Outer Circle and the Expanding Circle. However, young language learners' purposeful audience as a focus of communication has not been emphasized as much as other linguistic…

  6. Analysis of sea cliff slope stability integrating traditional geomechanical surveys and remote sensing

    Directory of Open Access Journals (Sweden)

    S. Martino

    2013-07-01

    Full Text Available An integrated approach to the geomechanical characterization of coastal sea cliffs was demonstrated at Mt. Pucci (Gargano promontory, Southern Italy by performing direct traditional geomechanical and remote geostructural investigations via Terrestrial Laser Scanner (TLS. The consistency of the integrated techniques allowed us to achieve a comprehensive and affordable characterization of the main joint sets on the sea cliff slope. The observed joint sets were observed to evaluate the susceptibility of the slope to rock falls by attributing safety factors (SFs to the topple- and wedge-prone rock blocks under three triggering conditions: (a filling with static water, (b seismic action, and (c weathering of joint surfaces. The results of the susceptibility analysis for the topple-prone blocks show that the critical height of water filling of the joint is up to 50 cm and that the critical pseudo-static acceleration values vary in the range of 0.16–0.3 g depending on the block geometry and slope face orientation. For the wedge blocks, the critical height of water filling of the joint is generally up to several centimeters, and the critical pseudo-static acceleration values vary in the range of 0.05–0.8 g depending on the block geometry and slope face orientation. Moreover, the unstable conditions of the blocks due to weathering generally represent 60% of the joint degradation of the intact rock. The combined action of weathering and static water fill was also considered, resulting in a significant decrease of the SFs. Specifically, unstable conditions are associated with water levels lower than 47% of the water levels observed in intact joints, even if less than 60% of the weathering is attributed to the joints. Furthermore, remote survey analyses via Thermal InfraRed Camera and Terrestrial SAR Interferometry (TInSAR were performed to evaluate the role of the surveyed joint sets in inducing instabilities in the Mt. Pucci sea cliff. The results of

  7. Influence in Times of Crisis : How Social and Financial Resources Affect Men's and Women's Evaluations of Glass-Cliff Positions

    NARCIS (Netherlands)

    Rink, Floor; Ryan, Michelle K.; Stoker, Janka I.

    2012-01-01

    In two scenario-based studies, we found that women and men evaluate glass-cliff positions (i.e., precarious leadership positions at organizations in crisis) differently depending on the social and financial resources available. Female and male participants evaluated a hypothetical leadership positio

  8. The Illinois Natural Heritage Conservation Education Kit V. [Ecology and Management of Special Habitats: Dune, Cave, Cliff, Bluff, and Urban.

    Science.gov (United States)

    Stone, Sally F.

    The ecology and management of special habitats is the theme of this instructional guide. It contains 24 activities designed to help teachers familiarize their students with dune, cave, cliff, bluff, and urban habitats in Illinois. Each activity (which is ready to be copied and given to students) includes an objective (called a mission) and…

  9. 76 FR 81994 - UniStar Nuclear Energy; Combined License Application for Calvert Cliffs Nuclear Power Plant, Unit...

    Science.gov (United States)

    2011-12-29

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION UniStar Nuclear Energy; Combined License Application for Calvert Cliffs Nuclear Power Plant, Unit 3; Exemption 1.0 Background: UniStar Nuclear Energy (UNE) submitted to the U.S. Nuclear...

  10. Thermal Modeling of NUHOMS HSM-15 and HSM-1 Storage Modules at Calvert Cliffs Nuclear Power Station ISFSI

    Energy Technology Data Exchange (ETDEWEB)

    Suffield, Sarah R.; Fort, James A.; Adkins, Harold E.; Cuta, Judith M.; Collins, Brian A.; Siciliano, Edward R.

    2012-10-01

    As part of the Used Fuel Disposition Campaign of the Department of Energy (DOE), visual inspections and temperature measurements were performed on two storage modules in the Calvert Cliffs Nuclear Power Station’s Independent Spent Fuel Storage Installation (ISFSI). Detailed thermal models models were developed to obtain realistic temperature predictions for actual storage systems, in contrast to conservative and bounding design basis calculations.

  11. Reactions to the glass cliff - Gender differences in the explanations for the precariousness of women's leadership positions

    NARCIS (Netherlands)

    Ryan, M.K; Haslam, S.A.; Postmes, T.

    2007-01-01

    Purpose - This paper aims to investigate the phenomenon of the glass cliff, whereby women are more likely than men to be placed in precarious leadership positions. Men's and women's reactions to this subtle form of gender discrimination are examined, the identity processes involved, and the implicat

  12. Think Crisis-Think Female : The Glass Cliff and Contextual Variation in the Think Manager-Think Male Stereotype

    NARCIS (Netherlands)

    Ryan, Michelle K.; Haslam, S. Alexander; Hersby, Mette D.; Bongiorno, Renata

    2011-01-01

    The "think manager think male" (TMTM) association underlies many gender inequalities in the workplace. However, research into the "glass cliff" has demonstrated that the suitability of male and female managers varies as a function of company performance such that in times of poor performance people

  13. Politics and the Glass Cliff: Evidence that Women Are Preferentially Selected to Contest Hard-to-Win Seats

    Science.gov (United States)

    Ryan, Michelle K.; Haslam, S. Alexander; Kulich, Clara

    2010-01-01

    Recent archival and experimental research has revealed that women are more likely than men to be appointed to leadership positions when an organization is in crisis. As a result, women often confront a "glass cliff" in which their position as leader is precarious. Our first archival study examined the 2005 UK general election and found…

  14. Juha Manninen and Friedrich Stadtler (eds., The Vienna Circle and the Nordic Countries. Networks and Transformations of Logical Empiricism (Vienna: Vienna Circle Institute Yearbook vol.14, Springer, 2010

    Directory of Open Access Journals (Sweden)

    Carlo Penco

    2013-03-01

    Full Text Available A discussion of The Vienna Circle and the Nordic Countries. Networks and Transformations of Logical Empiricism, edited by Juha Manninen and Friedrich Stadtler, Vienna Circle Institute Yearbook vol.14, Springer, 2010.

  15. Chemical Constituents of the Rare Cliff Plant Oresitrophe rupifraga and Their Antineuroinflammatory Activity.

    Science.gov (United States)

    Wu, Xi-Ying; Xiong, Juan; Liu, Xin-Hua; Hu, Jin-Feng

    2016-08-01

    Four new (1 - 4) and thirteen known (5 - 17) compounds were isolated from a rare cliff plant, Oresitrophe rupifraga. Based on spectroscopic evidence, the new structures were established to be [(2S,3R,4R)-4-(4-methoxybenzyl)-2-(4-methoxyphenyl)-tetrahydrofuran-3-yl]methanol (1), (3α)-23-(acetyloxy)-3-hydroxyolean-12-en-29-oic acid (2), 3α,23-(isopropylidenedioxy)olean-12-en-29-oic acid (3, artifact of isolation), and (3β,15β)-3-hydroxycholest-5-en-15-yl β-d-glucopyranoside (4), respectively. Among the isolates, compounds 1, 4, epieudesmin (7), and 1-O-(9Z,12Z,15Z-octadecatrienoyl)glycerol (17) were found to show significant antineuroinflammatory effects by inhibiting the NO production in lipopolysaccharide (LPS)-stimulated murine BV-2 microglial cells, with IC50 values of 7.21, 9.39, 4.96, and 8.51 μm, respectively.

  16. Pressurized thermal shock evaluation of the Calvert Cliffs Unit 1 Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Abbott, L [ed.

    1985-09-01

    An evaluation of the risk to the Calvert Cliffs Unit 1 nuclear power plant due to pressurized thermal shock (PTS) has been completed by Oak Ridge National Laboratory (ORNL) with the assistance of several other organizations. This evaluation was part of a Nuclear Regulatory Commission program designed to study the PTS risk to three nuclear plants, the other two plants being Oconee Unit 1 and H.B. Robinson Unit 2. The specific objectives of the program were to (1) provide a best estimate of the frequency of a through-the-wall crack in the pressure vessel at each of the three plants, together with the uncertainty in the estimated frequency and its sensitivity to the variables used in the evaluation; (2) determine the dominant overcooling sequences contributing to the estimated frequency and the associated failures in the plant systems or in operator actions; and (3) evaluate the effectiveness of potential corrective measures.

  17. The potential of low-cost RPAS for multi-view reconstruction of rock cliffs

    Science.gov (United States)

    Ettore Guccione, Davide; Thoeni, Klaus; Santise, Marina; Giacomini, Anna; Roncella, Riccardo; Forlani, Gianfranco

    2016-04-01

    RPAS, also known as drones or UAVs, have been used in military applications for many years. Nevertheless, the technology has become accessible to everyone only in recent years (Westoby et al., 2012; Nex and Remondino, 2014). Electric multirotor helicopters or multicopters have become one of the most exciting developments and several off-the-shelf platforms (including camera) are now available. In particular, RPAS can provide 3D models of sub-vertical rock faces, which for instance are needed for rockfall hazard assessments along road cuts and very steep mountains. The current work investigates the potential of two low-cost off-the-shelf quadcopters equipped with digital cameras for multi-view reconstruction of sub-vertical rock cliffs. The two platforms used are a DJI Phantom 1 (P1) equipped with a Gopro Hero 3+ (12MP) and a DJI Phantom 3 Professional (P3). The latter comes with an integrated 12MP camera mounted on a 3-axis gimbal. Both platforms cost less than 1.500€ including camera. The study area is a small rock cliff near the Callaghan Campus of the University of Newcastle (Thoeni et al., 2014). The wall is partly smooth with some evident geological features such as non-persistent joints and sharp edges. Several flights were performed with both cameras set in time-lapse mode. Hence, images were taken automatically but the flights were performed manually since the investigated rock face is very irregular which required adjusting the yaw and roll for optimal coverage since the flights were performed very close to the cliff face. The digital images were processed with a commercial SfM software package. Thereby, several processing options and camera networks were investigated in order to define the most accurate configuration. Firstly, the difference between the use of coded ground control targets versus natural features was studied. Coded targets generally provide the best accuracy but they need to be placed on the surface which is not always possible as rock

  18. The neglect of cliff instability can underestimate warming period melting in Antarctic ice sheet models

    CERN Document Server

    Ruckert, Kelsey L; Pollard, Dave; Guan, Yawen; Wong, Tony E; Forest, Chris E; Keller, Klaus

    2016-01-01

    The response of the Antarctic ice sheet (AIS) to changing climate forcings is an important driver of sea-level changes. Anthropogenic climate changes may drive a sizeable AIS tipping point response with subsequent increases in coastal flooding risks. Many studies analyzing flood risks use simple models to project the future responses of AIS and its sea-level contributions. These analyses have provided important new insights, but they are often silent on the effects of potentially important processes such as Marine Ice Sheet Instability (MISI) or Marine Ice Cliff Instability (MICI). These approximations can be well justified and result in more parsimonious and transparent model structures. This raises the question how this approximation impacts hindcasts and projections. Here, we calibrate a previously published AIS model, which neglects the effects of MICI, using a combination of observational constraints and a Bayesian inversion method. Specifically, we approximate the effects of missing MICI by comparing ou...

  19. Extreme Ground-Motion Rockfall Deposits on the Nevada Test Site

    Science.gov (United States)

    Whitney, J. W.; Buckingham, S. E.; Magner, J. E.; Finkel, R. C.; Brune, J. N.; von Seggern, D.; Honke, J. S.

    2007-12-01

    In order to detect the evidence of extreme ground motion in the past, we have begun to catalog geomorphic characteristics that distinguish slope deposits strongly influenced by extreme ground motion from deposits primarily influenced by climate processes. Underground nuclear explosions (UNEs) of yields between 200 kilotons and 1.3 megatons were conducted under Pahute Mesa at the Nevada Test site from 1962 to 1992. The primary surface effects from these tests were surface cracks, triggered earthquakes, offsets on pre-existing faults, and changes in land surface topography. Rockfall and rock spall were observed along cliffs after a few nuclear tests; however, few observations of accumulations of shattered rock were documented. A large volume of rockfall located along a 1.5-km¬-long cliff of welded ash-flow tuff resulted from extreme ground motions from two nearby UNEs. In 1968 UNE Rickey released maximum ground motions of 500 cm/s peak ground velocity (PGV) at the closest cliff face and PGV decreased to about 300 cm/s at the north end of the cliff. Large boulders with 1-3-m average diameters were shaken loose from fracture planes and cooling joints to form a stack of jumbled boulders at the base of the cliff. Very few large boulders rolled to the base of the hillslope. Subsequently, in 1976, UNE Pool induced 300-350 cm/s PGV along the same cliff. A significant volume of rock, also released along fractures and joints, was added to the coarse boulder colluvium shaken loose in 1968. Ground motion from Pool also rearranged the hillslope boulders from UNE Rickey, but did not cause many boulders to roll downslope. Extreme ground motions from these two UNEs resulted in 1.5-3.0 m of physical erosion to the cliff face. Rockfall from less welded ash-flow tuff units situated above and below the cliff produced significantly less boulder colluvium. Our observations indicate that boulder size and rockfall volume from a cliff or ridge crest due to extreme ground motion are

  20. Cliff top habitats provide important alternative feeding resources for wading birds of conservation importance wintering on non-estuarine coasts

    Science.gov (United States)

    Furnell, Julie; Hull, Susan L.

    2014-02-01

    Rocky shores and beaches are important over-wintering areas for non-estuarine waders but have rarely been studied. We examined cliff top habitat use by 6 species of wader over 75 km of coast to assess their potential value as alternative feeding sites to rocky and sandy shores. Both the regional and local survey showed that waders occurred on golf courses and recreational grasslands in higher frequencies than expected but arable and pasture use was lower than expected. We also compared local wader densities on rocky and sandy shores, pastures, golf courses, caravan parks and recreational grasslands over two winters. Sanderling predominantly fed on the beach whereas Oystercatcher, Dunlin, Turnstone and Redshank numbers significantly increased on golf courses and recreational grasslands over the winter period, with pasture being rarely used. General linear models were used to relate environmental factors to the presence and absence of each species on the cliff top habitats. Redshank was the only species that showed a higher probability of occurrence on cliff top habitats at high tide whereas the probability of Turnstone, Oystercatcher and Redshank occurring increased as temperatures declined. Using core sampling, we determined that invertebrate richness and abundance was significantly higher on the recreational grasslands and golf courses than on the pasture or the beach. Our data demonstrated that cliff top habitats are important alternative feeding areas for over-wintering waders in areas where the intertidal is bounded by cliffs. Current management creates short sward, open field habitats with a diverse and abundant invertebrate food supply exploited by waders. Any alterations to the land use of these areas should be carefully considered by planning authorities in light of the fact that they support species that are of conservation concern.

  1. The 50s cliff: a decline in perceptuo-motor learning, not a deficit in visual motion perception.

    Directory of Open Access Journals (Sweden)

    Jie Ren

    Full Text Available Previously, we measured perceptuo-motor learning rates across the lifespan and found a sudden drop in learning rates between ages 50 and 60, called the "50s cliff." The task was a unimanual visual rhythmic coordination task in which participants used a joystick to oscillate one dot in a display in coordination with another dot oscillated by a computer. Participants learned to produce a coordination with a 90° relative phase relation between the dots. Learning rates for participants over 60 were half those of younger participants. Given existing evidence for visual motion perception deficits in people over 60 and the role of visual motion perception in the coordination task, it remained unclear whether the 50s cliff reflected onset of this deficit or a genuine decline in perceptuo-motor learning. The current work addressed this question. Two groups of 12 participants in each of four age ranges (20s, 50s, 60s, 70s learned to perform a bimanual coordination of 90° relative phase. One group trained with only haptic information and the other group with both haptic and visual information about relative phase. Both groups were tested in both information conditions at baseline and post-test. If the 50s cliff was caused by an age dependent deficit in visual motion perception, then older participants in the visual group should have exhibited less learning than those in the haptic group, which should not exhibit the 50s cliff, and older participants in both groups should have performed less well when tested with visual information. Neither of these expectations was confirmed by the results, so we concluded that the 50s cliff reflects a genuine decline in perceptuo-motor learning with aging, not the onset of a deficit in visual motion perception.

  2. Inaccessible Biodiversity on Limestone Cliffs: Aster tianmenshanensis (Asteraceae, a New Critically Endangered Species from China.

    Directory of Open Access Journals (Sweden)

    Guo-Jin Zhang

    Full Text Available Aster tianmenshanensis G. J. Zhang & T. G. Gao, a new species of Asteraceae from southern China is described and illustrated based on evidence from morphology, micromorphology and molecular phylogeny. The new species is superficially similar to Aster salwinensis Onno in having rosettes of spatulate leaves and a solitary, terminal capitulum, but it differs by its glabrous leaf margins, unequal disc floret lobes and 1-seriate pappus. The molecular phylogenetic analysis, based on nuclear sequences ITS, ETS and chloroplast sequence trnL-F, showed that the new species was nested within the genus Aster and formed a well supported clade with Aster verticillatus (Reinw. Brouillet et al. The new species differs from the latter in having unbranched stems, much larger capitula, unequal disc floret lobes, beakless achenes and persistent pappus. In particular, A. tianmenshanensis has very short stigmatic lines, only ca. 0.18 mm long and less than 1/3 of the length of sterile style tip appendages, remarkably different from its congeners. This type of stigmatic line, as far as we know, has not been found in any other species of Aster. The very short stigmatic lines plus the unequal disc floret lobes imply that the new species may have a very specialized pollination system, which may be a consequence of habitat specialization. The new species grows only on the limestone cliffs of Mt. Tianmen, Hunan Province, at the elevation of 1400 m. It could only be accessed when a plank walkway was built across the cliffs for tourists. As it is known only from an area estimated at less than 10 km2 and a walkway passes through this location, its habitat could be easily disturbed. This species should best be treated as Critically Endangered based on the International Union for Conservation of Nature Red List Categories and Criteria B2a.

  3. Cliff-nesting seabirds influence production and sediment chemistry of lakes situated above their colony.

    Science.gov (United States)

    Hargan, K E; Michelutti, N; Coleman, K; Grooms, C; Blais, J M; Kimpe, L E; Gilchrist, G; Mallory, M; Smol, J P

    2017-01-15

    Seabirds that congregate in large numbers during the breeding season concentrate marine-derived nutrients to their terrestrial nesting sites, and these nutrients disperse and enhance production in nearby terrestrial, freshwater and marine ecosystems. In the Canadian Arctic, large seabird colonies (>100,000 breeding pairs) nest on cliff faces that drain directly in the ocean, ultimately returning the nutrients back to the marine environment from which they were derived. However, strong winds blowing up cliff faces could transport nutrients up in elevation and onto surrounding terrestrial and aquatic environments. Here, we assess the degree to which seabird nutrients and metals have been delivered to coastal lakes near Hudson Strait (Nunavut, Canada) over the past century. Three lakes located at a higher elevation and increasing distance from a thick-billed murre (Uria lomvia) colony (~400,000 breeding pairs) were sampled for surface water chemistry. In addition, algal assemblages, nitrogen isotopes, and metal/metalloids were analyzed in four dated sediment cores. Elevated nutrients and major ions, as well as an enriched δ(15)N signature in the sediment cores, were measured in the lake lakes >1km from the seabird colony. In contrast, similar oligotrophic and benthic diatom assemblages were identified in all three lakes, suggesting that diatoms were not influenced by enhanced nutrient inputs in this Arctic environment. Chemical tracers (e.g., total mercury) and algal assemblages in the lake near the colony suggest climate warming since ~1950 was the most likely driver of limnological changes, but this effect was muted in the more distant lakes. These pronounced changes in the seabird-impacted lake suggest that, with warming air temperatures and diminished lake ice cover, longer growing seasons may allow for aquatic organisms to more fully exploit the seabird nutrient subsidies.

  4. Talking Circles for Adolescent Girls in an Urban High School

    Directory of Open Access Journals (Sweden)

    Ann Schumacher

    2014-10-01

    Full Text Available Restorative Practices (RP in schools is a new and emerging field. Meeting in Circles to build friendships, develop emotional literacy skills, resolve conflict, or learn interactively are some of the core components of these programs. This article describes a 2-year study of 12 weekly Talking Circles organized under the auspices of a RP program in an urban high school with 60 adolescent girls. Primary data sources included 257 hr of participant observations in Talking Circles and individual, semi-structured interviews with 31 students. The Relational Cultural model, rooted in the work of Jean Baker Miller, served as the conceptual framework for understanding teens’ interactions within the Circle’s unique set of social conditions in a school environment. Findings demonstrated that Talking Circles provided a safe space for peers helping peers, and that the girls improved their listening, anger management, and empathic skills, which led to greater self-efficacy. It appears that Talking Circles could provide another venue for developing social-emotional literacy skills and growth-fostering relationships in schools.

  5. Circle Detection Using an Electromagnetism-Inspired Algorithm

    Directory of Open Access Journals (Sweden)

    Cuevas E.

    2011-10-01

    Full Text Available The Physic-inspired computation is becoming popular and has been acknowledged by the scientific community. This emerging area has developed a wide range of techniques and methods for dealing with complex problems. On the other hand, automatic circle detection in digital images has been considered as an important and complex task for the computer vision community that has devoted a tremendous amount of research seeking for an optimal circle detector. This article presents an algorithm for the automatic detection of circular shapes embedded into complicated and noisy images with no consideration of the conventional Hough transform techniques. The approach is based on a nature-inspired technique called the Electromagnetism- Like Optimization (EMO which is a heuristic method following electromagnetism principles for solving complex optimization problems. For the EMO algorithm, solutions are built considering the electromagnetic attraction and repulsion among charged particles with a charge representing the fitness solution for each particle. The algorithm uses the encoding of three non-collinear points as candidate circles over an edge-only image. Guided by the values of the objective function, the set of encoded candidate circles (charged particles are evolved using the EMO algorithm so that they can fit into the actual circles on the edge map of the image. Experimental results from several tests on synthetic and natural images with a varying range of complexity are included to validate the efficiency of the proposed technique regarding accuracy, speed, and robustness.

  6. Investigating controls on debris-flow initiation and surge frequency at Chalk Cliffs, USA: initial results from monitoring and modeling

    Science.gov (United States)

    Kean, J. W.; McCoy, S. W.; Tucker, G. E.; Staley, D. M.; Coe, J. A.

    2012-04-01

    Recent monitoring of a small (0.3 km2) bedrock-dominated catchment in central Colorado, USA, has revealed distinct differences in debris-flow surge dynamics relative to rainfall intensity. Moderate bursts of rainfall (15-40 mm/hr) typically trigger a set of coarse-grained surges with depths that can exceed 1.0 m. High-intensity bursts of rainfall (40-150 mm/hr), in contrast, often generate only a single moderate-amplitude coarse-grained surge (> 0.5 m depth), followed by several minutes of water-rich flow having comparable or greater peak depth. In both cases, debris flows are observed within minutes of rain bursts due to the rapid concentration of runoff from bedrock cliffs to channels loaded with sediment from dry ravel and rockfall. Video observations have shown that the runoff can initiate debris flows both at a steep (~40 degree) bedrock-colluvium interface, and in a lower gradient (~15 degree) section of channel. This latter style of initiation, which has only been observed at moderate rainfall intensity, involves the formation and failure of a highly porous sediment dam created by bedload transport. We speculate that this process may be responsible for the creation of the consistent surge patterns we observe with moderate intensity rainfall, and may explain the relative lack of granular surges with high-intensity rainfall. To investigate this possibility, we have developed a simple one-dimensional morphodynamic model of the formation and failure of sediment dams in an undulating bedrock channel filled with loose bed sediment. The model consists of a coupled surface-subsurface water flow model, which is used to drive bed-sediment topographic adjustments based on the mathematical divergence of the sediment transport rate. Under certain topographic and water-flow conditions, the shear stress in a section of the channel can fall below the critical shear stress, resulting in local deposition of sediment. Consistent with field observations, the modeled deposit

  7. An efficient circle detector not relying on edge detection

    Science.gov (United States)

    Cai, Jia; Huang, Panfeng; Chen, Lu; Zhang, Bin

    2016-06-01

    Accurate and efficient detection of circular modules fixed on non-cooperative target is a key technology for Tethered Space Robot. This paper presents an efficient circle detector based on region-growing of gradient and histogram distribution of Euclidean distance. Region-growing of gradient is applied to generate arc support regions from single point. And the corresponding square fitting areas are defined to accelerate the detection and decrease storage. A histogram is then used to count frequency of the distances that participates in the accumulator and the parameters of each circle are acquired. Finally, a verification strategy of circular integrity is designed to test the detection results. We have tested our algorithm on 35 images dealing with kinds of circles and ellipses. Experimental results demonstrate that our method is able to detect circular objects under occlusion, image noises and moderate shape deformations with a good precision.

  8. A Personified Annealing Algorithm for Circles Packing Problem

    Institute of Scientific and Technical Information of China (English)

    ZHANGDe-Fu; LIXin

    2005-01-01

    Circles packing problem is an NP-hard problem and is difficult to solve. In this paper, a hybrid search strategy for circles packing problem is discussed. A way of generating new configuration is presented by simulating the moving of elastic objects, which can avoid the blindness of simulated annealing search and make iteration process converge fast. Inspired by the life experiences of people,an effective personified strategy to jump out of local minima is given. Based on the simulated annealing idea and personification strategy, an effective personified annealing algorithm for circles packing problem is developed. Numerical experiments on benchmark problem instances show that the proposed algorithm outperforms the best algorithm in the literature.

  9. A Phase Transition for Circle Maps and Cherry Flows

    Science.gov (United States)

    Palmisano, Liviana

    2013-07-01

    We study C 2 weakly order preserving circle maps with a flat interval. The main result of the paper is about a sharp transition from degenerate geometry to bounded geometry depending on the degree of the singularities at the boundary of the flat interval. We prove that the non-wandering set has zero Hausdorff dimension in the case of degenerate geometry and it has Hausdorff dimension strictly greater than zero in the case of bounded geometry. Our results about circle maps allow to establish a sharp phase transition in the dynamics of Cherry flows.

  10. A Phase Transition for Circle Maps and Cherry Flows

    CERN Document Server

    Palmisano, Liviana

    2012-01-01

    We study $C^{2}$ weakly order preserving circle maps with a flat interval. The main result of the paper is about a sharp transition from degenerate geometry to bounded geometry depending on the degree of the singularities at the boundary of the flat interval. We prove that the non-wandering set has zero Hausdorff dimension in the case of degenerate geometry and it has Hausdorff dimension strictly greater than zero in the case of bounded geometry. Our results about circle maps allow to establish a sharp phase transition in the dynamics of Cherry flows.

  11. Research Circles - a method for developing guidance practices

    DEFF Research Database (Denmark)

    2012-01-01

    This video reports on our work with using research circles to improve our understanding of how to provide guidance and counseling to help young people in danger of dropping out of school. The video is based on the paper: Research Circles -- a method for developing guidance practices......, and was presented at the Conference for Social Justice, Prosperity and Sustainable Employment 2012 by assistant professor Helle Merete Nordentoft from DPU (http://edu.au.dk/). The film communicating the research paper was created by Mie Nørgaard...

  12. Secure Two-Party Point-Circle Inclusion Problem

    Institute of Scientific and Technical Information of China (English)

    Yong-Long Luo; Liu-Sheng Huang; Hong Zhong

    2007-01-01

    Privacy-preserving computational geometry is a special secure multi-party computation and has many applica-tions.Previous protocols for determining whether a point is inside a circle are not secure enough.We present a two-round protocol for computing the distance between two private points and develop a more efficient protocol for the point-circle inclusion problem based on the distance protocol.In comparison with previous solutions, our protocol not only is more secure but also reduces the number of communication rounds and the number of modular multiplications significantly.

  13. Circles Disturbed The Interplay of Mathematics and Narrative

    CERN Document Server

    Doxiadis, Apostolos

    2012-01-01

    Circles Disturbed brings together important thinkers in mathematics, history, and philosophy to explore the relationship between mathematics and narrative. The book's title recalls the last words of the great Greek mathematician Archimedes before he was slain by a Roman soldier--"Don't disturb my circles"--words that seem to refer to two radically different concerns: that of the practical person living in the concrete world of reality, and that of the theoretician lost in a world of abstraction. Stories and theorems are, in a sense, the natural languages of these two worlds--stories represent

  14. Role of shore platforms on coastal cliffs protection in Algarve (South Portugal): First approach

    Science.gov (United States)

    Gabriel, Selma; Moura, Delminda; Ferreira, Óscar; Pacheco, André; Matias, Ana; Veiga-Pires, Cristina; Jacob, José

    2010-05-01

    The complex interaction between morphogenetic processes acting on rocky coasts and substrate characteristics difficult the assessment of its evolution at different time scales. In opposition to other coastal environments such as beaches, where variations on substrate's attributes are constrained to a few possibilities, rocky coasts expose substrates having large amount of variables, among them, lithology, mechanical and chemical strength, density and orientation of faults and joints and, rocks' texture and structure (e.g., Trenhaile, 2003). Waves represent the most important energetic source on coastal areas and, abrasion, hammer effect and air compression in rocks discontinuities are the main mechanisms responsible for mechanical weathering induced by wave impact (e.g., Trenhaile, 1987, Sunamura, 1992). Shore platforms are the most conspicuous testimony of rocky cliffs recession. However, as shore platforms widen, cliffs foot rests out of the direct influence of breaking waves when sea level rise is slower than cliff retreat. Shore platforms have been reported as protective features against marine erosion by dissipating waves energy, its efficacy depending on height and slope (e.g., Porter et al., 2009; Trenhaile, 2010). The main objective of this work is to determine the role of shore platforms on cliffs protection at the Algarve (South Portugal) as monitored in two coastal sectors differently exposed to dominant waves. Coastal cliffs in the study area expose Miocene carbonate rocks with vertical facies variation between sub horizontal layers of calcarenites and siltstones, which represents a favourable geological context to the shore platform development. Waves height and period was measured along 12 months during spring tides and in some storm events by using pressure transducers. For that, pressure transducers were fixed into the rock in two coastal sectors positioned in both places at similar heights above mean sea level respectively for outer and inner edges

  15. Types of the cerebral arterial circle (circle of Willis in a Sri Lankan Population

    Directory of Open Access Journals (Sweden)

    Gunasekera WSL

    2011-01-01

    Full Text Available Abstract Background The variations of the circle of Willis (CW are clinically important as patients with effective collateral circulations have a lower risk of transient ischemic attack and stroke than those with ineffective collaterals. The aim of the present cadaveric study was to investigate the anatomical variations of the CW and to compare the frequency of prevalence of the different variations with previous autopsy studies as variations in the anatomy of the CW as a whole have not been studied in the Indian subcontinent. Methods The external diameter of all the arteries forming the CW in 225 normal Sri Lankan adult cadaver brains was measured using a calibrated grid to determine the prevalence in the variation in CW. Chisquared tests and a correspondence analysis were performed to compare the relative frequencies of prevalence of anatomical variations in the CW across 6 studies of diverse ethnic populations. Results We report 15 types of variations of CW out of 22 types previously described and one additional type: hypoplastic precommunicating part of the anterior cerebral arteries (A1 and contralateral posterior communicating arteries (PcoA 5(2%. Statistically significant differences (p Conclusion The present study reveals that there are significant variations in the CW among intra and inter ethnic groups (Caucasian, African and Asian: Iran and Sri Lanka dominant populations, and warrants further studies keeping the methods of measurements, data assessment, and the definitions of hypoplasia the same.

  16. CoSMoS (Coastal Storm Modeling System) Southern California v3.0 projections of coastal cliff retreat due to 21st century sea-level rise

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Summary: This dataset contains projections of coastal cliff-retreat rates and positions for future scenarios of sea-level rise (SLR). Projections were made using...

  17. Arctic circles, domino tilings and square Young tableaux

    CERN Document Server

    Romik, Dan

    2009-01-01

    The arctic circle theorem of Jockusch, Propp, and Shor asserts that uniformly random domino tilings of an Aztec diamond of high order are frozen with asymptotically high probability outside the "arctic circle" inscribed within the diamond. A similar arctic circle phenomenon has been observed in the limiting behavior of random square Young tableaux. In this paper, we show that random domino tilings of the Aztec diamond are asymptotically related to random square Young tableaux in a more refined sense that looks also at the behavior inside the arctic circle. This is done by giving a new derivation of the limiting shape of the height function of a random domino tiling of the Aztec diamond that uses the large-deviation techniques developed for the square Young tableaux problem in a previous paper by Pittel and the author. The solution of the variational problem that arises for domino tilings is almost identical to the solution for the case of square Young tableaux by Pittel and the author. The analytic techniques...

  18. A geometrical link between the circle and sexagesimal system

    CERN Document Server

    Julca, Jaime Vladimir Torres-Heredia

    2007-01-01

    This paper presents a simple geometrical fact which could relate to the history of mathematics and astronomy. This fact shows a natural link between the circle and the multiples of 6 and it makes it possible to obtain a simple representation of the 12 months of the year, the 24 hours of the day, the 30 days (average number) of the month and the 360 days (approximate number) of the year, which brings us closer to the sexagesimal division of time. Moreover this representation reminds one of the movement of the planets around a centre. Using this fact one will be able also to find geometrically the principal divisor of number 60, to represent numbers in base 60 with a kind of abacus or calculation table and to make a division of the circle into 6 and 12 equal parts. Afterwards one will be able to obtain a division in 360 unequal parts but relatively close to one another, and the goal isn't precisely to obtain an optimal division of the circle in 360 equal parts but to prove that the idea to divide the circle in ...

  19. Inclusive Teaching Circles: Mechanisms for Creating Welcoming Classrooms

    Science.gov (United States)

    Moore, Sharon; Wallace, Sherri L.; Schack, Gina; Thomas, M. Shelley; Lewis, Linda; Wilson, Linda; Miller, Shawnise; D'Antoni, Joan

    2010-01-01

    This essay examines the Inclusive Teaching Circle (ITC) as a mechanism for faculty development in creating instructional tools that embrace an inclusive pedagogy reflecting diversity, cultural competence and social justice. We describe one group's year-long participation in an ITC at a large, metropolitan research university in the south. Next, we…

  20. Outcomes and Accomplishments of The Circles of Care Planing Efforts

    Science.gov (United States)

    Duclos, Christine W.; Phillips, Mary; LeMaster, Pamela L.

    2004-01-01

    This paper presents outcomes and accomplishments of the first round of participating individuals, communities, and grantees of the Circles of Care program (CoC). While accomplishing all CoC program goals, the initiative supported grantees in developing individual service delivery system models and positioned each grantee advantageously for…

  1. Is Russell's vicious circle principle false or meaningless?

    NARCIS (Netherlands)

    Fleischhacker, L.E.

    1979-01-01

    P. Vardy asserts the thesis that the vicious circle principle has the same structure as Russell's paradox. But structure is not the thing itself. It is the thing objectivated from the wiewpoint of a mathematician. So this structure can be expressed in a mathematical formalism, e. g. the Λ-calculus.

  2. Perturbative analysis of maps of the circle onto itself

    Energy Technology Data Exchange (ETDEWEB)

    Zanetti, G. (Bologna Univ. (Italy). Ist. di Fisica); Turchetti, G. (Bologna Univ. (Italy). Ist. di Fisica; Istituto Nazionale di Fisica Nucleare, Bologna (Italy))

    1984-09-15

    As a model problem for the perturbation, up to break up, of tori in Hamoltonian mechanics, the map of the circle into itself is studied. By using classical perturbative techniques, not only the subcritical dynamics is well reproduced, but also the critical point is sharply defined and the conjugacy break up via the loss of differentiability is obtained in agreement with Shenker.

  3. Circle Time for Social and Emotional Learning in Primary School

    Science.gov (United States)

    Cefai, Carmel; Ferrario, Erika; Cavioni, Valeria; Carter, Audrey; Grech, Tracy

    2014-01-01

    This paper discusses the findings and implications of a semi-randomised control trial study on the effectiveness of circle time (CT) on primary school students' social and emotional learning, as well as classroom teachers' and students' experience of CT. A social and emotional learning programme was delivered through CT by trained classroom…

  4. Quantum Mechanics on the Circle and W_{1+\\INFTY}

    OpenAIRE

    Floreanini, R.; Percacci, R.; Sezgin, E.(George P. and Cynthia W. Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, TX, 77843-4242, USA)

    1991-01-01

    The algebra W_{1+\\infty} with central charge c=0 can be identified with the algebra of quantum observables of a particle moving on a circle. Mathematically, it is the universal enveloping algebra of the Euclidean algebra in two dimensions. Similarly, the super W_\\infty algebra is found to be the universal enveloping algebra of the super-Euclidean algebra in two dimensions.

  5. Geometric calibration of the circle-plus-arc trajectory.

    Science.gov (United States)

    Hoppe, Stefan; Noo, Frédéric; Dennerlein, Frank; Lauritsch, Günter; Hornegger, Joachim

    2007-12-07

    In this paper, a novel geometric calibration method for C-arm cone-beam scanners is presented which allows the calibration of the circle-plus-arc trajectory. The main idea is the separation of the trajectory into two circular segments (circle segment and arc segment) which are calibrated independently. This separation makes it possible to reuse a calibration phantom which has been successfully applied in clinical environments to calibrate numerous routinely used C-arm systems. For each trajectory segment, the phantom is placed in an optimal position. The two calibration results are then combined by computing the transformation the phantom underwent between the independent calibration runs. This combination can be done in a post-processing step by using standard linear algebra. The method is not limited to circle-plus-arc trajectories and works for any calibration procedure in which the phantom has a preferred orientation with respect to a trajectory segment. Results are presented for both simulated as well as real data acquired with a C-arm system. We also present the first image reconstruction results for the circle-plus-arc trajectory using real C-arm data.

  6. Revisiting Cyberbullying in Schools Using the Quality Circle Approach

    Science.gov (United States)

    Paul, Simone; Smith, Peter K.; Blumberg, Herbert H.

    2012-01-01

    An earlier study reported the use of Quality Circles (QC) in a UK school in the context of understanding and reducing bullying and cyberbullying. Here, we report further work in the same school setting. The QC approach allows explorative analysis of problems in school settings, whereby students embark on a problem-solving exercise over a period of…

  7. The Area of a Polygon with an Inscribed Circle

    CERN Document Server

    Buck, Marshall W

    2012-01-01

    Heron's formula states that the area $K$ of a triangle with sides $a$, $b$, and $c$ is given by $$ K=\\sqrt {s(s-a) (s-b) (s-c)} $$ where $s$ is the semiperimeter $(a+b+c)/2$. Brahmagupta, Robbins, Roskies, and Maley generalized this formula for polygons of up to eight sides inscribed in a circle. In this paper we derive formulas giving the areas of any $n$-gon, with odd $n$, in terms of the ordered list of side lengths, if the $n$-gon is circumscribed about a circle (instead of being inscribed in a circle). Unlike the cyclic polygon problem, where the order of the sides does not matter, for the inscribed circle problem (our case) it does matter. The solution is much easier than for the cyclic polygon problem, but it does generalize easily to all odd $n$. We also provide necessary and sufficient conditions for there to be solutions in the case of even $n$.

  8. Language Teachers through the Looking Glass: Expanding Circle Teachers' Discourse

    Science.gov (United States)

    Lovtsevich, Galina N.

    2005-01-01

    When English language teachers from Russia join in professional discourse with their counterparts from other countries, they do so in English, using a professional register which is, to a large extent, determined by language teaching theorists and practitioners in Inner Circle countries. This paper examines some of the issues surrounding…

  9. An Approach for Self-Calibration by a Quartered Circle

    Directory of Open Access Journals (Sweden)

    Yue Zhao

    2013-07-01

    Full Text Available The camera calibration is a key step for converting a projective reconstruction into a metric one, which is equivalent to recovering the unknown intrinsic parameters with each image. A circle is a common geometric primitive for the camera self-calibration. To avoid the limit of circle center to the camera self-calibration in a planar template, a method how to solve out the vanishing line is proposed. Then using the property of vanishing line, the camera intrinsic parameters are figured out and the camera self-calibration is achieved. The template contains a quartered circle in the study. Firstly, the camera is used to take photographs of the template from three or more direction. Secondly, using the ellipse and two mutually perpendicular diameters which are extracted from the image, according to the polarity principle and making use of the invariant property of cross-ratio of four lines which are intersected in one same point, the vanishing line can be solved out. In the end, the circular points can be figured out by the intersection between vanishing line and the circle. And using the property of the circular points, the self-calibration is realized.

  10. Literature Circles: A Perfect Match for Online Instruction

    Science.gov (United States)

    Whittingham, Jeff

    2013-01-01

    This article describes the author's search for an appropriate and satisfying online teaching method. After experimenting with several methods (chat room, discussion board, student led discussion), the author reached back to his face-to-face classroom success with literature circles. This article reports the results of research conducted by the…

  11. The Circle of Courage and Erikson's Psychological Stages.

    Science.gov (United States)

    Coughlan, Felicity; Welsh-Breetzke, Andrea

    2002-01-01

    Describes the application of positive youth development principles to challenges faced by adolescent females in South Africa. A mainline, Euro-centric theory, Erikson's life stages (1963), is compared with the Circle of Courage model based on Native American Tribal wisdom. The differences and correlation in these approaches are explored through…

  12. Using Literature Circles to Discuss Social Justice in Teacher Education

    Science.gov (United States)

    Madhuri, Marga; Walker, Nancy; Landmann-Johnsey, Erica; Laughter, Judson

    2015-01-01

    Literacy educators feel it is incumbent on teacher preparation programs to prepare teacher candidates with the dispositions and competencies needed to work with students from diverse racial, cultural, and economic backgrounds. As a way to initiate the discussion and help candidates examine their own views on race, literature circles are used. The…

  13. Majorization algorithms for inspecting circles, ellipses, squares, rectangles, and rhombi

    NARCIS (Netherlands)

    K. van Deun; P.J.F. Groenen (Patrick)

    2003-01-01

    textabstractIn several disciplines, as diverse as shape analysis, location theory, quality control, archaeology, and psychometrics, it can be of interest to fit a circle through a set of points. We use the result that it suffices to locate a center for which the variance of the distances from the ce

  14. Defining Leadership: Collegiate Women's Learning Circles: A Qualitative Approach

    Science.gov (United States)

    Preston-Cunningham, Tammie; Elbert, Chanda D.; Dooley, Kim E.

    2017-01-01

    The researchers employed qualitative methods to evaluate first-year female students' definition of "leadership" through involvement in the Women's Learning Circle. The findings revealed that students defined leadership in two dimensions: traits and behaviors. The qualitative findings explore a multidimensional approach to the voices of…

  15. Investigating a rock instability. Exemple of the "Bornes du Diable" cliff, Switzerland

    Science.gov (United States)

    Franz, Martin; Michoud, Clément; Güell Pons, Maria; Pedrazzini, Andrea; Jaboyedoff, Michel

    2010-05-01

    The « Bornes du Diable » cliff is located in the Val de Bagnes in south western Valais. In September 2008, a block of about 2000 m3 has fallen down causing damages to a small alpine road. This event shows the potential instability of the whole cliff which represents a larger volume. Indeed it measures 160 m high and about 100 m width. Several back-cracks are visible hundred meters back to the actual crest. The road, the reservoir of Mauvoisin and the related dam could be reached by the rockfalls. The goal of this study is to characterize the structural settings and to quantify the previous displacements that occurred in the area in order to assess the present day stability. Structural, geomorphological and geomechanical characterization have been carried by field investigations and completed by orthophotos and digital elevation model analysis. The unstable area was scanned in fall 2009 using terrestrial laser scanner (TLS) in order to have a very detailed topography and to perform a structural analysis using the home made software Coltop3D. Differential GPS campaign was initiated in July 2009 and will be continued for the next years to assess the potential movement affecting the entire area. Moreover, a photogrammetric analysis of two aerial photographs of 1979 and 2000 is performed to identify if previous movements occurred in the area. The potential unstable volume is estimated performing the Sloping Local Base Level method and geometrical analysis. Finally a model is performed with the UDEC™ and FLAC® softwares. The movement, the discontinuity sets, the rockfall mechanisms and the triggering factors are analyzed to define the deep structures and the mechanisms of a potential complete collapse. The preliminary results indicate an important rock fracturing in the area of the instability. The persistence schistosity and the highly weathered rock surface indicating a fair-poor rock mass quality. TLS point cloud analysis using Coltop3D highlights six

  16. Estimation of Site Effects on Stations in the Capital Circle Region Using the Generalized Inversion Method

    Institute of Scientific and Technical Information of China (English)

    Shi Haixia; Xiu Jigang; Chen Zhangli; Wang Qincai; Hua Wei

    2010-01-01

    Generalized Inversion Method has been used to estimate the spatial variation of site effects,using the digital data of SH-waves recorded by 63 stations in the Capital Circle Region of China from 2001 to 2006.We gained the site effects of all stations participating in the calculation.We found that the site effect of rock was stabile and about 1.0 from 1.0Hz to10.0Hz,while the site effect of deposit was high in low frequencies,about 3~7 from1.0Hz to 8.0Hz,and the site effect was protuberant at about 5.0Hz,then fell as the frequency increased.The result shows the shape and intensity of station site effects are mainly influenced by the lithology below the station,and possibly also by the local geological structure.

  17. Optimizing care in osteoporosis: The Canadian quality circle project

    Directory of Open Access Journals (Sweden)

    Kvern Brent

    2008-10-01

    Full Text Available Abstract Background While the Osteoporosis Canada 2002 Canadian guidelines provided evidence based strategies in preventing, diagnosing, and managing this condition, publication and distribution of guidelines have not, in and of themselves, been shown to alter physicians clinical approaches. We hypothesize that primary care physicians enrolled in the Quality Circle project would change their patient management of osteoporosis in terms of awareness of osteoporosis risk factors and bone mineral density testing in accordance with the guidelines. Methods The project consisted of five Quality Circle phases that included: 1 Training & Baseline Data Collection, 2 First Educational Intervention & First Follow-Up Data Collection 3 First Strategy Implementation Session, 4 Final Educational Intervention & Final Follow-up Data Collection, and 5 Final Strategy Implementation Session. A total of 340 circle members formed 34 quality circles and participated in the study. The generalized estimating equations approach was used to model physician awareness of risk factors for osteoporosis and appropriate utilization of bone mineral density testing pre and post educational intervention (first year of the study. Odds ratios (OR and 95% confidence intervals (95% CI were calculated. Results After the 1st year of the study, physicians' certainty of their patients' risk factor status increased. Certainty varied from an OR of 1.4 (95% CI: 1.1, 1.8 for prior vertebral fracture status to 6.3 (95% CI: 2.3, 17.9 for prior hip fracture status. Furthermore, bone mineral density testing increased in high risk as compared with low risk patients (OR: 1.4; 95% CI: 1.2, 1.7. Conclusion Quality Circle methodology was successful in increasing both physicians' awareness of osteoporosis risk factors and appropriate bone mineral density testing in accordance with the 2002 Canadian guidelines.

  18. Investigation of dust bands from blue ice fields in the Lewis Cliff (Beardmore) area, Antarctica: A progress report

    OpenAIRE

    Koeberl, Christian; Yanai,Keizo; Cassidy, William A.; Schutt,John W.

    1988-01-01

    Blue ice fields in Antarctica are well known for their high areal meteorite concentrations. The exact type of accumulation model and the age of the ice is still not well known. Dust bands on blue ice fields may help to clarify some of these problems. Dust, which has been isolated from dust band samples from blue ice areas in the Lewis Cliff/Walcott Neve area (Beardmore region), Antarctica, was studied to determine petrographic characteristics and chemical compositions. One sample has an avera...

  19. Cliff´s Delta Calculator: A non-parametric effect size program for two groups of observations

    Directory of Open Access Journals (Sweden)

    Guillermo Macbeth

    2011-05-01

    Full Text Available The Cliff´s Delta statistic is an effect size measure that quantifies the amount of difference between two non-parametric variables beyond p-values interpretation. This measure can be understood as a useful complementary analysis for the corresponding hypothesis testing. During the last two decades the use of effect size measures has been strongly encouraged by methodologists and leading institutions of behavioral sciences. The aim of this contribution is to introduce the Cliff´s Delta Calculator software that performs such analysis and offers some interpretation tips. Differences and similarities with the parametric case are analysed and illustrated. The implementation of this free program is fully described and compared with other calculators. Alternative algorithmic approaches are mathematically analysed and a basic linear algebra proof of its equivalence is formally presented. Two worked examples in cognitive psychology are commented. A visual interpretation of Cliff´s Delta is suggested. Availability, installation and applications of the program are presented and discussed.

  20. Performance of Deep and Shallow Neural Networks, the Universal Approximation Theorem, Activity Cliffs, and QSAR.

    Science.gov (United States)

    Winkler, David A; Le, Tu C

    2017-01-01

    Neural networks have generated valuable Quantitative Structure-Activity/Property Relationships (QSAR/QSPR) models for a wide variety of small molecules and materials properties. They have grown in sophistication and many of their initial problems have been overcome by modern mathematical techniques. QSAR studies have almost always used so-called "shallow" neural networks in which there is a single hidden layer between the input and output layers. Recently, a new and potentially paradigm-shifting type of neural network based on Deep Learning has appeared. Deep learning methods have generated impressive improvements in image and voice recognition, and are now being applied to QSAR and QSAR modelling. This paper describes the differences in approach between deep and shallow neural networks, compares their abilities to predict the properties of test sets for 15 large drug data sets (the kaggle set), discusses the results in terms of the Universal Approximation theorem for neural networks, and describes how DNN may ameliorate or remove troublesome "activity cliffs" in QSAR data sets.

  1. Don'T fall off the adaptation cliff: when asymmetrical fitness selects for suboptimal traits.

    Directory of Open Access Journals (Sweden)

    Elodie Vercken

    Full Text Available The cliff-edge hypothesis introduces the counterintuitive idea that the trait value associated with the maximum of an asymmetrical fitness function is not necessarily the value that is selected for if the trait shows variability in its phenotypic expression. We develop a model of population dynamics to show that, in such a system, the evolutionary stable strategy depends on both the shape of the fitness function around its maximum and the amount of phenotypic variance. The model provides quantitative predictions of the expected trait value distribution and provides an alternative quantity that should be maximized ("genotype fitness" instead of the classical fitness function ("phenotype fitness". We test the model's predictions on three examples: (1 litter size in guinea pigs, (2 sexual selection in damselflies, and (3 the geometry of the human lung. In all three cases, the model's predictions give a closer match to empirical data than traditional optimization theory models. Our model can be extended to most ecological situations, and the evolutionary conditions for its application are expected to be common in nature.

  2. The 50s cliff: perceptuo-motor learning rates across the lifespan.

    Directory of Open Access Journals (Sweden)

    Rachel O Coats

    Full Text Available We recently found that older adults show reduced learning rates when learning a new pattern of coordinated rhythmic movement. The purpose of this study was to extend that finding by examining the performance of all ages across the lifespan from the 20 s through to the 80 s to determine how learning rates change with age. We tested whether adults could learn to produce a novel coordinated rhythmic movement (90° relative phase in a visually guided unimanual task. We determined learning rates to quantify changes in learning with age and to determine at what ages the changes occur. We found, as before, that learning rates of participants in their 70 s and 80 s were half those of participants in their 20 s. We also found a gradual slow decline in learning rate with age until approximately age 50, when there was a sudden drop to a reduced learning rate for the 60 though 80 year olds. We discuss possible causes for the "50 s cliff" in perceptuo-motor learning rates and suggest that age related deficits in perception of complex motions may be the key to understanding this result.

  3. Microaneurysms detection with the radon cliff operator in retinal fundus images

    Energy Technology Data Exchange (ETDEWEB)

    Giancardo, Luca [ORNL; Meriaudeau, Fabrice [ORNL; Karnowski, Thomas Paul [ORNL; Tobin Jr, Kenneth William [ORNL; Li, Yaquin [University of Tennessee, Knoxville (UTK); Chaum, Edward [University of Tennessee, Knoxville (UTK)

    2010-01-01

    Diabetic Retinopathy (DR) is one of the leading causes of blindness in the industrialized world. Early detection is the key in providing effective treatment. However, the current number of trained eye care specialists is inadequate to screen the increasing number of diabetic patients. In recent years, automated and semi-automated systems to detect DR with color fundus images have been developed with encouraging, but not fully satisfactory results. In this study we present the initial results of a new technique for the detection and localization of microaneurysms, an early sign of DR. The algorithm is based on three steps: candidates selection, the actual microaneurysms detection and a final probability evaluation. We introduce the new Radon Cliff operator which is our main contribution to the field. Making use of the Radon transform, the operator is able to detect single noisy Gaussian-like circular structures regardless of their size or strength. The advantages over existing microaneurysms detectors are manifold: the size of the lesions can be unknown, it automatically distinguishes lesions from the vasculature and it provides a fair approach to microaneurysm localization even without post-processing the candidates with machine learning techniques, facilitating the training phase. The algorithm is evaluated on a publicly available dataset from the Retinopathy Online Challenge.

  4. Topographic control of sorted circle morphology on Svalbard

    Science.gov (United States)

    Voigt, Joana; Hauber, Ernst; Reiss, Dennis; Hiesinger, Harald; Johnsson, Andreas; van Gasselt, Stephan; Balme, Matt; Head, Jim; de Verra, Jean-Pierre; Steinbrügge, Gregor; Jaumann, Ralf

    2015-04-01

    Patterned ground is a typical phenomenon in polar, subpolar and alpine regions [1]. As it is commonly (but not necessarily!) related to freeze-thaw cycles, its presence on Mars could possibly point to locations and periods where and when liquid water existed in the recent past [2]. Sorted circles are a class of patterned ground that was tentatively identified in Elysium Planitia (Mars) [3], but this interpretation has been challenged on the basis of physical considerations [4]. Without direct access to potential patterned ground on Mars, the analysis of terrestrial analogues can inform the interpretation of Martian landforms. Svalbard (Norway) offers a wide variety of permafrost features that are morphologically analogous to Martian cold-climate landforms [5]. It hosts some of the best examples of sorted circles on Earth, which are located on the westernmost tip of Brøgger peninsula, on a broad strand flat that is characterized by a series of postglacial beach ridges [6]. Here we report on our analysis of sorted circle morphology (especially their plan-view shape, i.e. their "roundness" or ellipticity) and its correlation with local topography (slopes, curvature). Sorted circle morphology was determined from HRSC-AX images (for details on the flight campaign and image properties see ref [5]) and through field work. Topographic information comes from a 50 cm gridded DEM derived from HRSC-AX stereo images. We measured sorted circle morphology (ellipticity, azimuth of major axis) along a WNW-ESE traverse that runs from the inland towards the sea and is oriented perpendicular to the local beach ridge trend. Selected areas with homogeneous sorted circle appearance were visually mapped, and compared to the average slope, aspect, and the calculated topographic wetness index (TWI). Furthermore the whole traverse was classified into four different morphologies of the sorted patterned ground (sorted circles, sorted "ellipses", sorted nets and areas without patterned ground

  5. Developing Reading Activities by Litearture Circles : In the Case of a Japanese Language Arts Classroom

    OpenAIRE

    山元, 隆春; 居川, あゆ子

    2013-01-01

    In this paper, possibilities of the “Literature Circle" practice in native language classes were explored. By considering on Japanese Language Arts lessons using the idea of “Literature Circle", by one teacher, we found such lessons had effects to enhance students' appetite for learning and reading abilities. And we also suggested that the “Literature Circle" methodology would be effective to developing students' abilities for “criticizing any texts," then we must adapt “Literature Circle" in...

  6. The perfect storm: Unusual synchronisation of the components of wave energy spectra dominates episodic soft-cliff erosion.

    Science.gov (United States)

    Hackney, Christopher; Darby, Stephen

    2015-04-01

    Between December 2013 and February 2014 the United Kingdom experienced the stormiest winter on record. The persistent low pressure systems arriving from the North Atlantic during this period resulted in some of the most energetic maritime conditions ever recorded along the English Channel. The unprotected soft cliffs which comprise the south west Isle of Wight coastline were highly exposed to these conditions, facing the full force of extreme sea-levels and significant wave heights. Although long term rates of soft-cliff erosion have previously been defined for this coastline, the role of such extreme forcings on rates of soft-cliff erosion has not previously been document, and is therefore relatively poorly understood. We employed pre-event LIDAR and post-event RTK-GPS shoreline surveys in tandem with hourly sea-levels and significant wave height records from the English Channel to build an unprecedented data set that we use here to determine the response of this soft-cliff coastline to the extreme forcings of the 2013/2014 winter. It was found that the between October 2013 and March 2014, the south west Isle of Wight eroded, on average 4.25 m (σ = 3.6m). Such a high degree of erosion is approximately a factor of nine times greater than the long term average retreat rate of ~0.5 m/yr for this coastline and is the largest recorded erosion event since the start of reliable records began. The extreme erosion observed is shown to be a result of the synchronisation between sea-levels and wave heights. Indeed, we show that a 7-hour lag of the wave height record relative to background sea-level would have resulted in only half (2.1 m) of the observed erosion. An analysis of the historical record implies that previous extreme erosion events were a function of similar synchronisation between sea-levels and wave heights, thus it is likely that future changes in the timing of peak sea-levels and wave heights have the potential to outweigh changes in magnitude in terms of

  7. The Chicken and the Egg: Inviting Response and Talk through Socratic Circles

    Science.gov (United States)

    Styslinger, Mary E.; Pollock, Timothy

    2010-01-01

    This collaborative inquiry answers the following questions: 1) What is the nature of talk during Socratic Circles? 2) What is student response to talk? 3) How might knowing more about student response to talk and the nature of talk improve teaching during Socratic Circles? The article first describes the process of implementing Socratic Circles,…

  8. Calculation of Latitude and Longitude for Points on Perimeter of a Circle on a Sphere

    Energy Technology Data Exchange (ETDEWEB)

    Morris, Heidi E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-14

    This document describes the calculation of the Earth-Centered Earth Fixed (ECEF) coordinates for points lying on the perimeter of a circle. Here, the perimeter of the circle lies on the surface of the sphere and the center of the planar circle is below the surface. These coordinates are converted to latitude and longitude for mapping fields on the surface of the earth.

  9. Native American Values and Management Education: Envisioning an Inclusive Virtuous Circle

    Science.gov (United States)

    Verbos, Amy Klemm; Gladstone, Joe S.; Kennedy, Deanna M.

    2011-01-01

    Circles are symbols of interconnectedness. Behavioral circles can be vicious or virtuous. Many American Indians are caught in a vicious circle of exclusion from the purported benefits of Westernization, entrapment in its negative elements, and the ongoing undermining of their culture and thus their identities. Yet Native Americans, along with many…

  10. Life and death of ice cliffs and lakes on debris covered glaciers - insights from a new dataset from the Nepalese Himalaya

    Science.gov (United States)

    Steiner, Jakob; Buri, Pascal; Miles, Evan; Ragettli, Silvan; Pellicciotti, Francesca

    2016-04-01

    Numerous studies suggest that supraglacial ice cliffs and lakes could be one contributing factor to relatively high overall ablation rates on debris covered glaciers. While some studies have quantified backwasting rates, developments over the larger scale have not yet been assessed. Field work and earlier studies during three seasons in the Langtang catchment in the Nepalese Himalaya has given some insights into how these landforms develop, from initial emergence to persistence and disappearance. From 6 sets of concurrent high-resolution satellite imagery and DEMs between 2006 and 2015 and an additional image from 1974, we assembled an extensive dataset of these landforms on all glaciers in the catchment, including nearly 4000 individual lakes and cliffs. We show that ice cliffs appear in combination with lakes or without and there are lakes that are not bordered by a cliff. Numbers vary strongly between seasons, especially as lakes show strong seasonal variability. There are furthermore different types of cliff forms - circular, lateral and longitudinal - that give an indication of their formation process. Circular cliffs form with either collapsing subglacial channels or overdeepenings caused by water accumulating on the surface, while lateral cliffs are likely associated with underlying crevasses. Some of the cliff and lake systems remain at the same location on-glacier over a number of years, while most move with the whole glacier body down valley. From the DEMs determine preferential slopes and expositions of the cliffs in the catchment which have been shown to be essential aspects in explaining the backwasting process. In combination with field observations from one glacier, where most of these types were present, we can infer development processes of a number of systems over the whole catchment. It is also apparent that densities of these landforms vary greatly over the glacier surface, which can be explained with velocities or underlying bed topography in

  11. Protocol for Isolating the Mouse Circle of Willis.

    Science.gov (United States)

    Hur, Justine Claire; Blaise, Régis; Limon, Isabelle

    2016-10-22

    The cerebral arterial circle (circulus arteriosus cerebri) or circle of Willis (CoW) is a circulatory anastomosis surrounding the optic chiasma and hypothalamus that supplies blood to the brain and surrounding structures. It has been implicated in several cerebrovascular disorders, including cerebral amyloid angiopathy (CAA)-associated vasculopathies, intracranial atherosclerosis and intracranial aneurysms. Studies of the molecular mechanisms underlying these diseases for the identification of novel drug targets for their prevention require animal models. Some of these models may be transgenic, whereas others will involve isolation of the cerebro-vasculature, including the CoW.The method described here is suitable for CoW isolation in any mouse lineage and has considerable potential for screening (expression of genes, protein production, posttranslational protein modifications, secretome analysis, etc.) studies on the large vessels of the mouse cerebro-vasculature. It can also be used for ex vivo studies, by adapting the organ bath system developed for isolated mouse olfactory arteries.

  12. Culture Circles in adolescent empowerment for the prevention of violence.

    Science.gov (United States)

    Monteiro, Estela Maria Leite Meirelles; Neto, Waldemar Brandão; de Lima, Luciane Soares; de Aquino, Jael Maria; Gontijo, Daniela Tavares; Pereira, Beatriz Oliveira

    2015-04-03

    An action research based on Paulo Freire's Culture Circles was developed to implement a health education intervention involving adolescents, in collective knowledge construction about strategies for the prevention of violence. The data collection in the Culture Circles involved 11 adolescents and included observation and field diary, photographic records and recording. The educational action aroused a critical socio-political and cultural position in the adolescents towards the situations of vulnerability to violence, including the guarantee of human rights, justice and the combat of inequities; changes in the social relations, combat against discrimination and intolerance; expansion of access and reorientation of health services through intersectoral public policies. The intervention empowered the group of adolescents for the prevention of violence and permitted the inclusion of health professionals in the school context, from an interdisciplinary perspective, contributing to the establishment of social support and protection networks.

  13. Landscapes, Circles and Antikythera: The Birth of the Mechanical Universe

    Science.gov (United States)

    Edmunds, M. G.

    The joint Greek/UK/US Antikythera Mechanism Research Project is currently producing a definitive set of experimental optical and X-ray imaging data of the Mechanism. The interpretation will require a good knowledge of the context in which it was made. Following from the sacred landscapes of northern Europe it is difficult to escape the symbolism of the "circle" in prehistoric cosmologies, and the pre-eminence of the circle in Greek astronomical thought is obvious. Is the "circular" ikon of the main wheel in Antikythera Mechanism simply another gear wheel, or might ideas of cosmology have influenced its design? How important would devices like the Antikythera Mechanism have been in providing a physical model of the Universe , pushing mathematical abstraction into reality? The relevance of the Mechanism is understanding the development of ideas and philosophy, particularly determinism is emphasized.

  14. BANQUET SPEECH Full Circle: Star Ferry to Stardust

    Science.gov (United States)

    Matthews, Clifford N.

    2008-10-01

    Good evening. I'd like to invite you to join me on a journey that could be entitled “Full Circle: Star Ferry to Stardust”. “Star Ferry” represents Hong Kong, my home town, and especially its university - Hong Kong University - as I knew it during the years of World War II. “Stardust” refers to our gathering here to report on our research on possible organic chemistry in space.

  15. Uncertainty budget for optical coordinate measurements of circle diameter

    DEFF Research Database (Denmark)

    Morace, Renate Erica; Hansen, Hans Nørgaard; De Chiffre, Leonardo

    2004-01-01

    An uncertainty analysis for circle diameter measurements using a coordinate measuring machine (CMM) equipped with an optical probe is presented in this paper. A mathematical model for data evaluation and uncertainty assessment was formulated in accordance with Guide to the Expression of Uncertainty...... in Measurement (GUM). Various input quantities such as CCD camera resolution, influence of illuminating system, CMM errors etc. were considered in the model function and experimentally investigated....

  16. Quality Circles: An Innovative Program to Improve Military Hospitals

    Science.gov (United States)

    1982-08-01

    effective teamwork, (3) promote job involvemenL, (4) increase employee motivation , (5) create a problem-solving capability, (6) build an attitude of...from greater employee motivation and involve- ment in work. Quality Circles (Q.C.’s) are small groups of volunteers from the same work area who meet on...effectiveness Measurable feedback Key people and team members in same area for better personnel management Greater productivity Employee motivation Effective use

  17. The Quality Circles Organizational Intervention: An Attitudinal Outcome Study

    Science.gov (United States)

    1983-09-01

    communication between themselves and their employees "(Dickson, 1982). Victor Vroom has developed a "normative model" of par- ticipative decision...SECUMIYY CLASSIOPI CAr? MO h LSSR 19-83 THE QUALITY CIRCLES ORGANIZATIONAL INTERVENTION: AN ATTITUDINAL OUTCOME STUDY A Thesis Presented ýo the...democratic style, and a set of seven rules intended to pro- tect both the quality and acceptance of a leader’s decision. -26 Vroom provides a decision

  18. About Nodal Systems for Lagrange Interpolation on the Circle

    Directory of Open Access Journals (Sweden)

    E. Berriochoa

    2012-01-01

    Full Text Available We study the convergence of the Laurent polynomials of Lagrange interpolation on the unit circle for continuous functions satisfying a condition about their modulus of continuity. The novelty of the result is that now the nodal systems are more general than those constituted by the n roots of complex unimodular numbers and the class of functions is different from the usually studied. Moreover, some consequences for the Lagrange interpolation on [-1,1] and the Lagrange trigonometric interpolation are obtained.

  19. Largest Empty Circle Centered on a Query Line

    CERN Document Server

    Augustine, John; Roy, Sasanka

    2008-01-01

    The Largest Empty Circle problem seeks the largest circle centered within the convex hull of a set $P$ of $n$ points in $\\mathbb{R}^2$ and devoid of points from $P$. In this paper, we introduce a query version of this well-studied problem. In our query version, we are required to preprocess $P$ so that when given a query line $Q$, we can quickly compute the largest empty circle centered at some point on $Q$ and within the convex hull of $P$. We present solutions for two special cases and the general case; all our queries run in $O(\\log n)$ time. We restrict the query line to be horizontal in the first special case, which we preprocess in $O(n \\alpha(n) \\log n)$ time and space, where $\\alpha(n)$ is the slow growing inverse of the Ackermann's function. When the query line is restricted to pass through a fixed point, the second special case, our preprocessing takes $O(n \\alpha(n)^{O(\\alpha(n))} \\log n)$ time and space. We use insights from the two special cases to solve the general version of the problem with pr...

  20. A contribution for predicting Tsunami inundation induced by rock fall along the Gaeta cliff (Central Italy)

    Science.gov (United States)

    di Manna, P.; Vittori, E.; Comerci, V.; Amanti, M.; Cesi, C.

    2009-04-01

    Many sectors of Italian coasts are characterized by tall scarps, close to large or pocket beaches that display ramp shape with moderate to low acclivity profile. During the summer, all these beaches are densely populated by sunbathers. Moreover, Italian coastal areas are often intensely urbanized even at a short distance from the sea and very close to sea level. Being cliffs often affected by gravity processes, the impact on the water of a falling volume of rock, depending on size and height of fall, may represent a potential source of tsunami-type hazard for adjacent beaches and boats. In this work we present an attempt to evaluate the run-up and ingression values in the Serapo beach (Gaeta, Tyrrhenian Sea coast of Central Italy) of an anomalous wave induced by a potential rock fall along the contiguous more than 100 meters high limestone cliff (the so-called Montagna Spaccata, "cleft mountain"). Detailed geological and geomorphological field analyses are being carried out, including geomechanical analyses and geodetic monitoring, in order to recognize the sectors with the most critical stability conditions. Preliminarily, the major potential volume of instable block and its most likely kinematics have been estimated with the purpose of characterizing the rock fall process. The first water rise produced by the impact of the rock on the sea surface has been estimated according to two approaches: a) the Murty (2003) equation, that gives the relation between water elevation and volume of fallen material; b) the Glasstone and Dolan method (Hills & Mader, 1997), comparing the carbonate rock fall to a meteoritic impact on the sea surface. The rockfall kinematics suggests that the Glasstone and Dolan equation, despite it was developed for a different environment, is better applicable than Murty's (valid for slides) to the case under discussion. On the basis of the Green's law (1837) we defined the shoaling component of the run-up values. Our results show that the impact

  1. Population genetics of self-incompatibility in a clade of relict cliff-dwelling plant species.

    Science.gov (United States)

    Silva, Jose L; Brennan, Adrian C; Mejías, José A

    2016-01-01

    The mating systems of species in small or fragmented populations impact upon their persistence. Small self-incompatible (SI) populations risk losing S allele diversity, responsible for the SI response, by drift thereby limiting mate availability and leading to population decline or SI system breakdown. But populations of relict and/or endemic species have resisted these demographic conditions over long periods suggesting their mating systems have adapted. To address a lack of empirical data on this topic, we studied the SI systems of three relict cliff-dwelling species of Sonchus section Pustulati (Asteraceae): S. masguindalii, S. fragilis and S. pustulatus in the western Mediterranean region. We performed controlled pollinations within and between individuals to measure index of SI (ISI) expression and identify S alleles in multiple population samples. Sonchus masguindalii and S. pustulatus showed strong SI (ISI = 0.6-1.0) compared to S. fragilis (ISI = 0.1-0.7). Just five S alleles were estimated for Spanish S. pustulatus and a moderate 11-15 S alleles for Moroccan S. pustulatus and S. fragilis, respectively. The fact that autonomous fruit set was generally improved by active self-pollination in self-compatible S. fragilis suggests that individuals with weak SI can show a wide range of outcrossing levels dependent on the degree of self or outcross pollen that pollinators bear. We conclude that frequent S allele dominance interactions that mask the incompatibility interactions of recessive S alleles leading to higher mate availability and partial breakdown of SI leading to mixed mating, both contribute to reproductive resilience in this group.

  2. Modeling granular material flows: The angle of repose, fluidization and the cliff collapse problem

    Science.gov (United States)

    Holsapple, Keith A.

    2013-07-01

    I discuss theories of granular material flows, with application to granular flows on the earth and planets. There are two goals. First, there is a lingering belief of some that the standard continuum plasticity Mohr-Coulomb and/or Drucker-Prager models are not adequate for many large-scale granular flow problems. The stated reason for those beliefs is the fact that the final slopes of the run-outs in collapse, landslide problems, and large-scale cratering are well below the angle of repose of the material. That observation, combined with the supposition that in those models flow cannot occur with slopes less than the angle of repose, has led to a number of researchers suggesting a need for lubrication or fluidization mechanisms and modeling. That issue is investigated in detail and shown to be false. A complete analysis of slope failures according to the Mohr-Coulomb model is presented, with special attention to the relations between the angle of repose and slope failures. It is shown that slope failure can occur for slope angles both larger than and smaller than the angle of repose. Second, to study the details of landslide run-outs, finite-difference continuum code simulations of the prototypical cliff collapse problem, using the classical plasticity models, are presented, analyzed and compared to experiments. Although devoid of any additional fluidization models, those simulations match experiments in the literature extremely well. The dynamics of this problem introduces additional important features relating to the run-out and final slope angles. The vertical free surface begins to fall at the initial 90° and flow continues to a final slope less than 10°. The detail in the calculation is examined to show why flow persists at slope angles that appear to be less than the angle of repose. The motions include regions of solid-like, fluid-like, and gas-like flows without invoking any additional models.

  3. Pre-failure behaviour of an unstable limestone cliff from displacement and seismic data

    Directory of Open Access Journals (Sweden)

    J.-L. Got

    2010-04-01

    Full Text Available We monitored the displacement and seismic activity of an unstable vertical rock slice in a natural limestone cliff of the southeast Vercors massif, southeast France, during the months preceding its collapse. Displacement measurements showed an average acceleration of the movement of its top, with clear increases in the displacement velocity and in the discrete seismic event production rate during periods where temperature falls, with more activity when rainfall or frost occurs. Crises of discrete seismic events produce high amplitudes in periodograms, but do not change the high frequency base noise level rate. We infer that these crises express the critical crack growth induced by water weakening (from water vapor condensation or rain of the rock strength rather than to a rapid change in applied stresses. Seismic noise analysis showed a steady increase in the high frequency base noise level and the emergence of spectral modes in the signal recorded by the sensor installed on the unstable rock slice during the weeks preceding the collapse. High frequency seismic noise base level seems to represent subcritical crack growth. It is a smooth and robust parameter whose variations are related to generalized changes in the rupture process. Drop of the seismic noise amplitude was concomitant with the emergence of spectral modes – that are compatible with high-order eigenmodes of the unstable rock slice – during the later stages of its instability. Seismic noise analysis, especially high frequency base noise level analysis may complement that of inverse displacement velocity in early-warning approaches when strong displacement fluctuations occur.

  4. Influence of meteorological factors on rockfall occurrence in a middle mountain limestone cliff

    Directory of Open Access Journals (Sweden)

    J. D'Amato

    2015-12-01

    Full Text Available The influence of meteorological conditions on rockfall occurrence has been often highlighted, but its knowledge is still not sufficient due to the lack of exhaustive and precise rockfall data bases. In this study, rockfalls have been detected in a limestone cliff by annual terrestrial laser scanning, and dated by photographic survey during 2.5 years. A near-continuous survey (1 photo each 10 mn with a wide-angle lens have allowed dating 214 rockfalls larger than 0.1 m3, and a monthly survey with a telephoto lens, dating 854 rockfalls larger than 0.01 m3. The analysis of the two data bases shows that the rockfall frequency can be multiplied by a factor as high as 7 during freeze–thaw episodes and 26 when the mean rainfall intensity (since the beginning of the rainfall episode is higher than 5 mm h−1. Based on these results, a 4-level scale has been proposed for predicting the temporal variations of hazard. The more precise data base and freeze–thaw episode definition make it possible to distinguish different phases in freeze–thaw episodes: negative temperature cooling periods, negative temperature warming periods and thawing periods. It appears that rockfalls occur more frequently during warming and thawing periods than during cooling periods. It can be inferred that rockfalls are caused by thermal ice dilatation rather than by dilatation due to the phase transition. But they may occur only when the ice melt, because the cohesion of the ice–rock interface can be sufficient to hold the rock compartment which has been cut.

  5. Volume calculation of the spur gear billet for cold precision forging with average circle method

    Institute of Scientific and Technical Information of China (English)

    Wangjun Cheng; Chengzhong Chi; Yongzhen Wang; Peng Lin; Wei Liang; Chen Li

    2014-01-01

    Forging spur gears are widely used in the driving system of mining machinery and equipment due to their higher strength and dimensional accuracy. For the purpose of precisely calculating the volume of cylindrical spur gear billet in cold precision forging, a new theoretical method named average circle method was put forward. With this method, a series of gear billet volumes were calculated. Comparing with the accurate three-dimensional modeling method, the accuracy of average circle method by theoretical calculation was estimated and the maximum relative error of average circle method was less than 1.5%, which was in good agreement with the experimental results. Relative errors of the calculated and the experimental for obtaining the gear billet volumes with reference circle method are larger than those of the average circle method. It shows that average circle method possesses a higher calculation accuracy than reference circle method (traditional method), which should be worth popularizing widely in calculation of spur gear billet volume.

  6. Rockfall frequency and influence of meteorological factors on a limestone cliff of the urban area of Grenoble.

    Science.gov (United States)

    D'Amato, Julie; Hantz, Didier; Baillet, Laurent; Guerin, Antoine; Jaboyedoff, Michel

    2015-04-01

    The spatial temporal frequency of rockfall events helps to quantify diffuse rockfall hazard. The influence of meteorological factors can also be studied in order to better know the failure triggering factors, and to predict dangerous periods of the year. Detection and dating of some hundreds of rockfalls has been carried out for the Saint Eynard cliff, which towers above a residential area of the town of Grenoble (French Alps), and which consists of a thinly bedded limestone cliff. The rockfalls have been detected by a diachronic comparison of digital models of the cliff, obtained from annual terrestrial laser scanning. They have been dated by means of a continuous photographic and seismic survey of the cliff. Meteorological data are given by local temperature and rain stations. These data allowed to study the influence of meteorological factors in the failure process. Six hundreds rockfalls (volume 0.005m3 to 1500m3) have been dated by periods of 2 to 11 weeks. The average frequency of the detected rockfalls for the 18 months of survey is 1.0 rockfall per day. The winter periods (with freeze-thaw cycles) clearly show a higher rockfall frequency, up to 1.9 rockfall per day for the most active winter periods. Summer periods show a lower rockfall frequency, between 0.1 and 0.5 rockfall per day. The frequency is close to 0.5 for periods with more rainfall. 126 rockfalls were dated with a precision of 10 min to several hours. For these rockfalls, the average frequency is 0.010 rockfall/h. The frequency is 0.015 rockfall/h for the freezing days (days with negative minimal temperature), 0.029 rockfall/h for the days without freeze but following a freezing day, 0.011 rockfall/h for the days with a rainfall and 0.002 rockfall/h for the other days. Rainfall and freeze-thaw events have also been determined hourly. A rainfall event begins with the beginning of a rainfall, and ends at the beginning of the next 24 hours period without rain. The 24h period has been chosen

  7. Coastal cliff geometry derived from structure-from-motion photogrammetry at Stara Ba\\vska, Krk Island, Croatia

    Science.gov (United States)

    Ružić, Igor; Marović, Ivan; Benac, Čedomir; Ilić, Suzana

    2014-12-01

    The aim of this study was to examine the capability of structure-from-motion photogrammetry in defining the geometry of cliffs and undercuts in rocks of complex geomorphology. A case site was chosen along pocket beaches near the village of Stara Ba\\vska on the Adriatic Sea island of Krk, Gulf of Kvarner, Croatia, where cliff erosion of 5 m in breccias was identified by comparison of aerial photographs from 1960 and 2004. The 3D point cloud was derived from approx. 800 photos taken on 9 January 2014 by a single camera from various elevations and angles, and processed using the online software ReCap (Autodesk). Data acquisition was found to be quick and the method easy to implement. The difference between the georeferenced 3D cloud points and an RTK-GPS survey was 7 cm, i.e. within the limits of RTK-GPS precision. Quantifying the spatial variation in undercut geometries revealed that the deepest and largest (17 m3) undercut was in the south-eastern sector of the beach. Reconstructing the detailed geomorphology of this 3.8-m-deep undercut convincingly demonstrates the high efficiency of the method. Such assessments of spatiotemporal changes in undercut and overhang volumes can prove useful for evaluations of cliff erosion risk. Coupled with the low cost and relatively simple application, this is evidently an attractive technique for meaningful geotechnical and coastal engineering monitoring in the future on the island of Krk and, for that matter, also on other Adriatic islands and in similar settings worldwide.

  8. Unusual death of millipedes (Diplopoda towards the north of the Varkala Cliff section near Papanasam, Kerala, India

    Directory of Open Access Journals (Sweden)

    P.K. Sarkar

    2011-08-01

    Full Text Available The cliff section at Varkala, Kerala consisting of clay, lignite band, clay, sandy-clay, sandstone of Mio-Pliocene age. This sedimentary sequence is overlain by a thick laterite. Above the lower lignite band, in the exposed clay beds several struggling and dead millipedes can be observed. Their death is probably due to the action of dehydration related to the sulphuric water infiltration in the sediments. However, it still remains a mystery why these millipedes choose such a toxic environment to create their habitat?

  9. Cliff collapses in the Alps, some fundamentals and a case study. Mineralogical aspects of the 1991 Randa Rockfall (Wallis, Switzerland)

    Energy Technology Data Exchange (ETDEWEB)

    Thelin, P.; Girod, F. [Lausanne Univ., Lausanne (Switzerland). Institut de Mineralogie et de Geochimie

    2000-07-01

    The study of risks related to geochemical contamination of soil, water and atmosphere caused by the human activity seems to have become the priority as far as the environment is concerned. However among many other challenges which Earth Sciences must take up at the end of the 20. century, research into natural risks needs to be made a priority. Among the latter, in addition to the volcanic and seismic risks, the instability of hills lopes, potentially leading to landslides and cliff collapses, is to be considered with the greatest attention, in particular in the context of climatic reheating and excessive deforestation.

  10. METALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>20070291 Gong Ping (Northern Fujian Geological Party, Shaozou 354000) Discussion on Geological Characteristics and Control Factors of the Shimen Au-polymetallic Deposit in Zhenghe County, Fujian Province (Geology of Fujian, ISSN1001-3970, CN38-1080/P, 25(1), 2006, p.18-24, 2 illus., 2 tables, 1 ref.) Key words: gold deposits, polymetallic deposits, Fujian Province

  11. Stereoscopic Machine-Vision System Using Projected Circles

    Science.gov (United States)

    Mackey, Jeffrey R.

    2010-01-01

    A machine-vision system capable of detecting obstacles large enough to damage or trap a robotic vehicle is undergoing development. The system includes (1) a pattern generator that projects concentric circles of laser light forward onto the terrain, (2) a stereoscopic pair of cameras that are aimed forward to acquire images of the circles, (3) a frame grabber and digitizer for acquiring image data from the cameras, and (4) a single-board computer that processes the data. The system is being developed as a prototype of machine- vision systems to enable robotic vehicles ( rovers ) on remote planets to avoid craters, large rocks, and other terrain features that could capture or damage the vehicles. Potential terrestrial applications of systems like this one could include terrain mapping, collision avoidance, navigation of robotic vehicles, mining, and robotic rescue. This system is based partly on the same principles as those of a prior stereoscopic machine-vision system in which the cameras acquire images of a single stripe of laser light that is swept forward across the terrain. However, this system is designed to afford improvements over some of the undesirable features of the prior system, including the need for a pan-and-tilt mechanism to aim the laser to generate the swept stripe, ambiguities in interpretation of the single-stripe image, the time needed to sweep the stripe across the terrain and process the data from many images acquired during that time, and difficulty of calibration because of the narrowness of the stripe. In this system, the pattern generator does not contain any moving parts and need not be mounted on a pan-and-tilt mechanism: the pattern of concentric circles is projected steadily in the forward direction. The system calibrates itself by use of data acquired during projection of the concentric-circle pattern onto a known target representing flat ground. The calibration- target image data are stored in the computer memory for use as a

  12. Geophysical methods to investigate and survey unstable volumes along a cliff

    Science.gov (United States)

    Levy, Clara; Baillet, Laurent; Jongmans, Denis; Mourot, Philippe; Hantz, Didier

    2010-05-01

    We successively instrumented 2 unstable sites along the 300 m high Urgonian cliff of the southern Vercors massif, French Alps. The first site, a rock column of 21000 m3, collapsed in November 2007, 5 months after the beginning of measurements. The experiment showed that information contained in seismic noise can be used for hazard assessment when considering the potential failure of an overhanging rock column. Indeed, the study of seismic noise recorded prior the rock fall revealed that low resonance frequencies follow a precursory pattern, as they decrease significantly, from 3.4 Hz to 2.6 Hz, before the collapse. We successfully reproduced this phenomenon with 2D numerical modelling of rock falls. Numerical simulation results pointed out that this decrease depends on the column-to-mass contact stiffness, which is controlled by the remaining rock bridges. Impulsive signals, which could be attributed to rock fracturing, have also been studied. P and S waves were identified for 40 events, allowing wave polarisation analysis and preliminary event location. Seismic sources able to trigger the vibration of the rock column were located along the broken plane and probably resulted from micro-cracks along rock bridges. From this first site study, we tried to closely follow the evolution of the natural frequencies at the second site, which also consists of a rock column decoupling from the mass with an open fracture in the rear. The value of the first eigenfrequency (about 7.6 Hz in June 2008) shows that the unstable volume is probably much smaller than for the first site. This evaluation is consistent with the estimated volume using DEM derived from LIDAR scan (about 1000 m3). A detailed investigation of the first eigenfrequency shows that its variation is also correlated with temperature and frost. After one year of a rough stability, the average value of the first eigenfrequency clearly shows a drift with the temperature variation pattern and an irreversible decrease of

  13. Voice of the voiceless: The legacy of the Circle of Concerned African Women Theologians

    Directory of Open Access Journals (Sweden)

    Hazel O. Ayanga

    2016-07-01

    Full Text Available The Circle of Concerned African Women Theologians (the Circle formally came into existence in 1989 in Accra, Ghana. Under the charismatic leadership of Mercy Amba Oduyoye, the Circle sought to be the voice of African Christian women at the grass roots level. To this end research and publication was and still is one of the major pillars and activities of the Circle. The main objective of the Circle is �to write and publish theological literature written by African women from their own experience of religion and culture on this continent�. In this regard the Circle has been and continues to be the voice for and on behalf of the African woman in religion, culture and theology. However, 25 years down the line there is need for an evaluation of the legacy of the Circle. How has the Circle been a voice for the voiceless, a mentoring instrument for women venturing into the academia? This article seeks to do this evaluation by examining the activities of the Circle including research publication.Intradisciplinary and/or interdisciplinary implications: This article seeks to evaluate the achievements of the Circle of Concerned African Women Theologians in relation to the Circle�s stated objectives. The article picks up the notion of the Circle theologians as the voice of the voiceless women of Africa. The general approach of the article brings together discussions on social issues like gender, poverty and marginalisation as well as language. Theological and religious perspectives on these issues are understood from a Circle point of view.Keywords: women; voice; voicelessness; poverty; gender; The Circle; theology

  14. [Albert Fromme (1881-1996) and his circle].

    Science.gov (United States)

    Klimpel, V

    1996-12-01

    Among Saxony's schools of surgery, Albert Fromme's in Dresden attain importance. On the basis of his work as a university professor in Göttingen for 10 years, he was able to train a large circle of surgeons in a major hospital. However, this did not detract from his clinical and scientific work. A. Fromme reached the top of German surgery and his crowning achievement was gaining the full professorship and rectorship of the Medical Academy "Carl Gustav Carus" in Dresden (today the Medical Faculty of the Technical University.

  15. The Phenomenological Circle and the Unity of Life and Thought.

    Science.gov (United States)

    Atwood, George E; Stolorow, Robert D

    2016-06-01

    This paper describes the important role of our deep immersions in philosophy in the development of our phenomenological-contextualist approach to psychoanalysis. Influenced most particularly by the phenomenological movement, our collaborative dialogue over more than four decades has led us to a shared commitment to reflection upon the philosophical underpinnings and constitutive contexts of origin of all our theoretical ideas. The growth of our thinking follows an endlessly recurring phenomenological circle joining theoretical perspectives with the inquirers from whose emotional worlds they arise.

  16. Star Formation Beyond the Solar Circle: A Survey of Surveys

    Science.gov (United States)

    Kerton, Charles R.

    2013-06-01

    This talk will review and distill the results of major radio, infrared, and combined radio/IR, surveys that have focused on the identification and characterization of active regions of star formation in the outer Galaxy. These surveys reveal that, in terms of star formation activity, the Milky Way beyond the solar circle is not a vast wasteland, but rather it is an area containing numerous regions of star formation well placed for detailed individual study, for large-scale studies of star formation within spiral arms, and for comparative studies with star formation occurring in different environments such as the inner Galaxy and Galactic center.

  17. Influence in times of crisis: how social and financial resources affect men's and women's evaluations of glass-cliff positions.

    Science.gov (United States)

    Rink, Floor; Ryan, Michelle K; Stoker, Janka I

    2012-01-01

    In two scenario-based studies, we found that women and men evaluate glass-cliff positions (i.e., precarious leadership positions at organizations in crisis) differently depending on the social and financial resources available. Female and male participants evaluated a hypothetical leadership position in which they would have both social and financial resources, financial resources but no social resources, or social resources but no financial resources. Women evaluated the position without social resources most negatively, whereas men evaluated the position without financial resources most negatively. In study 2, we found that women and men considered different issues when evaluating these leadership positions. Women's evaluations and expected levels of influence as leaders depended on the degree to which they expected to be accepted by subordinates. In contrast, men's evaluations and expected levels of acceptance by subordinates depended on the degree to which they expected to be influential in the position. Our findings have implications for the understanding of the glass-cliff phenomenon and gendered leadership stereotypes.

  18. SPECTRA OF MOTHERS OF PREMATURE CHILDREN ABOUT THE EDUCATIVE CIRCLE OF CULTURE

    Directory of Open Access Journals (Sweden)

    Camila Santos do Couto

    2014-12-01

    Full Text Available Abstract We sought to know the spectra of mothers of premature children regarding their experience with circle of culture of educational character and identifying the learning provided by the circle of culture about newborn care after hospital discharge. A descriptive study was performed in a hospital located in Fortaleza, Brazil. Three meetings of a circle of culture with 17 mothers of premature newborns were performed. The interpretation of the corpus was performed using thematic analysis. Emerged from the categories: Maternal experience in a circle of culture; Promoted social support among mothers through the circle of culture; and Learning provided by the circle of culture. It was concluded that teaching parents during the hospitalization of the child should be held in a way to involve parents in the care of the newborn, provide moments of health education, opportunities for support and dialogue between professionals and family.

  19. Eccentricity on AN Image Caused by Projection of a Circle and a Sphere

    Science.gov (United States)

    Matsuoka, R.; Maruyama, S.

    2016-06-01

    Circular targets on a plane are often utilized in photogrammetry, particularly in close range photogrammetry, while spherical targets are sometimes utilized in industrial applications. Both a circle and a sphere are projected as an ellipse onto an image. There is an eccentricity on an image between the centre of the projected ellipse and the projected location of the centre of a circle or a sphere. Since only the centre of the projected ellipse is measured, the correction of the eccentricity is considered to be necessary for highly accurate measurement. This paper shows a process to derive general formulae to calculate an eccentricity of a circle and a sphere using the size and the location of a circle or a sphere, and the focal length, the position and the attitude of a camera. Furthermore the paper shows methods to estimate the eccentricity of a circle and a sphere from the equation of the projected ellipse of a circle or a sphere on an image.

  20. Beyond paradigms in Organization Studies: the Circle of Epistemic Matrices

    Directory of Open Access Journals (Sweden)

    Ana Paula Paes de Paula

    Full Text Available Abstract In this article, I present a sketch of a new proposition to guide organizational studies: the Cicle of Epistemic Matrices. Inspired by Thomas Kuhn and based on the thesis of paradigms' incommensurability, Gibson Burrell and Gareth Morgan drew the diagram of sociological paradigms, but its inclusion in the academy has encouraged a paradigms war. The Circle of Epistemic Matrices also provides an outline for the guidance of organizational studies, but it is based on Habermas and defends the thesis of cognitive incompleteness, suggesting that the sociological and organizational knowledge grows according to the thesis of epistemic reconstructions. To accomplish these propositions and elaborations, I present the debate about the paradigms' war in literature and I question the adequacy of sociological paradigms of Gibson Burrell and Gareth Morgan to organizational studies, with the issue of the influence that it suffered from Kuhnian paradigms and logic. In the following sections, there is an exhibition of alternative proposition - the of Circle of Epistemic Matrices - and, also, I support the thesis of cognitive incompleteness and the thesis of epistemic reconstructions in order to bring a new theory of knowledge development to the area. Finally, I present the findings and thoughts for future research.

  1. Drawing Euler Diagrams with Circles: The Theory of Piercings.

    Science.gov (United States)

    Stapleton, Gem; Leishi Zhang; Howse, John; Rodgers, Peter

    2011-07-01

    Euler diagrams are effective tools for visualizing set intersections. They have a large number of application areas ranging from statistical data analysis to software engineering. However, the automated generation of Euler diagrams has never been easy: given an abstract description of a required Euler diagram, it is computationally expensive to generate the diagram. Moreover, the generated diagrams represent sets by polygons, sometimes with quite irregular shapes that make the diagrams less comprehensible. In this paper, we address these two issues by developing the theory of piercings, where we define single piercing curves and double piercing curves. We prove that if a diagram can be built inductively by successively adding piercing curves under certain constraints, then it can be drawn with circles, which are more esthetically pleasing than arbitrary polygons. The theory of piercings is developed at the abstract level. In addition, we present a Java implementation that, given an inductively pierced abstract description, generates an Euler diagram consisting only of circles within polynomial time.

  2. Strange Non-Chaotic Attractors in Quasiperiodically Forced Circle Maps

    Science.gov (United States)

    Jäger, Tobias

    2009-07-01

    The occurrence of strange non-chaotic attractors (SNA) in quasiperiodically forced systems has attracted considerable interest over the last two decades, in particular since it provides a rich class of examples for the possibility of complicated dynamics in the absence of chaos. Their existence was first described by Millions̆c̆ikov (and later by Vinograd and also Herman) for quasiperiodic {SL(2, {mathbb R})} -cocycles and by Grebogi et al (and later Keller) for so-called pinched skew products. However, except for these two particular classes there are still hardly any rigorous results on the topic, despite a large number of numerical studies confirming the widespread existence of SNA in quasiperiodically forced systems. Here, we prove the existence of SNA in quasiperiodically forced circle maps under rather general conditions, which can be stated in terms of {{mathcal C}^1} -estimates. As a consequence, we obtain the existence of SNA for parameter sets of positive measure in suitable parameter families. These SNA carry the unique physical measure of the system, which determines the behaviour of Lebesgue-almost all initial conditions. Finally, we show that the dynamics are minimal in the considered situations. The results apply in particular to a forced version of the Arnold circle map. For this example, we also describe how the first Arnold tongue collapses and looses its regularity due to the presence of strange non-chaotic attractors and a related unbounded mean motion property.

  3. Accurate episomal HIV 2-LTR circles quantification using optimized DNA isolation and droplet digital PCR

    OpenAIRE

    Eva Malatinkova; Maja Kiselinova; Pawel Bonczkowski; Wim Trypsteen; Peter Messiaen; Jolien Vermeire; Bruno Verhasselt; Karen Vervisch; Linos Vandekerckhove; Ward De Spiegelaere

    2014-01-01

    Introduction: In HIV-infected patients on combination antiretroviral therapy (cART), the detection of episomal HIV 2-LTR circles is a potential marker for ongoing viral replication. Quantification of 2-LTR circles is based on quantitative PCR or more recently on digital PCR assessment, but is hampered due to its low abundance. Sample pre-PCR processing is a critical step for 2-LTR circles quantification, which has not yet been sufficiently evaluated in patient derived samples. Materials and M...

  4. Studies on Escherichia coli sex factors: evidence that covalent circles exist within cells and the general problem of isolation of covalent circles.

    Science.gov (United States)

    Freifelder, D; Folkmanis, A; Kirschner, I

    1971-03-01

    We examined in detail conditions necessary for making reproducible and for maximizing the amount of deoxyribonucleic acid obtained from a sex factor-containing cell as covalent circles. The results argue that under optimal conditions covalent circles are neither created nor lost during the isolation procedure. The causes of the culture-to-culture variation in recovery of covalent circular deoxyribonucleic acid were investigated but an understanding of this is not yet at hand. Some commonly used conditions which drastically reduce the recovery of covalent circles are described.

  5. The outcrop and area underlain by the Upper Cretaceous Drip Tank Mb. of the Straight Cliffs Fm. in the Kaiparowits Plateau study area, southern Utah (kaikdtg)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This is a polygon file of the outcrop and area underlain by the Drip Tank Mb. of the Straight Cliffs Fm. (Upper Cretaceous) east of 112 degrees of longitude in the...

  6. Minimalisasi Kekurangan Material Melalui Implementasi Quality Control Circle

    Directory of Open Access Journals (Sweden)

    Togar W. S. Panjaitan

    2011-01-01

    Full Text Available The revolution of traditional quality management concept into total quality management (TQM inspired industry for establishing and implementing quality control circle (QCC. Before starting a project as the implementation of the QCC, the training was held for supporting the knowledge of the QCC team. As the pilot project of the QCC, this research will try to minimize the percentage of the lack material in the production process of 8340 type by working together with the QCC team. The result of QCC implementation could reach the target set by the team, the percentage of the lack material reached less than 3%. The percentage of the lack material kontaktarm reduced from 3.09% to 0.00%, flachdrahtspule reduced from 9.20% to 0.40%, and niet reduced from 7.71% to 2.73%. Besides, the implementation of QCC also resulted in positive impact for all the members of the team about the benefits and experiences gained.

  7. Application of digital holography to circle flow bed boiler measurement

    Institute of Scientific and Technical Information of China (English)

    PU Shiliang; Denis Lebrun; WANG Qinghui; CEN Kefa; REN Kuanfang

    2007-01-01

    The spatial distribution of particles in the boiler is very important in the study on the circle flow bed boiler (CFB). Digital in-line holography technique was applied to obtain the spatial and diameter distribution of the particles inside the boiler. A HE-NE laser was used to illuminate the particles inside the CFB through two glass windows and the in-line diffraction pattern was recorded by a CCD camera. The diffraction can be interpreted as a convolution between a family of wavelet functions and the object function. So the three-dimensional (3D) images of the particles in the two-phase flow were reconstructed by the convolution between diffraction pattern and wavelet functions. The particle diameters and 3D coordinates were calculated from the reconstructed 3D images by a series of image-processing methods, followed by a discussion of the experimental results.

  8. Two personification strategies for solving circles packing problem

    Institute of Scientific and Technical Information of China (English)

    黄文奇[1; 许如初[2

    1999-01-01

    Two personification strategies are presented, which yield a highly efficient and practical algorithm for solving one of the NP hard problems——circles packing problem on the basis of the quasi-physical algorithm. A very clever polynomial time complexity degree approximate algorithm for solving this problem has been reported by Dorit S.Hochbaum and Wolfgang Maass in J. ACM. Their algorithm is extremely thorough-going and of great theoretical significance. But, just as they pointed out, their algorithm is feasible only in conception and even for examples frequently encountered in everyday life and of small scale, it is the case more often than not that up to a million years would be needed to perform calculations with this algorithm. It is suggested toward the end of their paper that a heuristic algorithm of higher practical effectiveness should be sought out. A direct response to their suggestion is intented to provide.

  9. Planar maps, circle patterns and 2d gravity

    CERN Document Server

    David, Francois

    2013-01-01

    Via circle pattern techniques, random planar triangulations (with angle variables) are mapped onto Delaunay triangulations in the complex plane. The uniform measure on triangulations is mapped onto a conformally invariant spatial point process. We show that this measure can be expressed as: (1) a sum over 3-spanning-trees partitions of the edges of the Delaunay triangulations; (2) the volume form of a K\\"ahler metric over the space of Delaunay triangulations, whose prepotential has a simple formulation in term of ideal tessellations of the 3d hyperbolic space; (3) a discretized version (involving finite difference complex derivative operators) of Polyakov's conformal Fadeev-Popov determinant in 2d gravity; (4) a combination of Chern classes, thus also establishing a link with topological 2d gravity.

  10. The interpersonal circle as a heuristic model for interpersonal research.

    Science.gov (United States)

    Lorr, M

    1996-04-01

    In this article, I review major advances in the development of the interpersonal circle and its measurement, as delineated by Timothy Leafy (1957) and his colleagues. In my early work (Lorr & McNair, 1963, 1965), an interpersonal Behavior Inventory consisting of manifest behavioral statements was constructed. The 14 categories were found to fit a circular order in several samples. Studies using LaForge and Suczek's (1955) Interpersonal Check List, and Wiggins's (1979) Interpersonal Adjective Scales further established the value of Leary's conceptions and extended them. Several major theorists, researchers, and clinicians including Benjamin, Carson, Horowitz, Kiesler, and Wiggins have been inspired by Leary and, in many cases, have extended his ideas in ways not originally envisioned. Recent research (e.g., Hofstee, de Raad, & Goldberg, 1992; Millon, 1987) demonstrated the pertinence of the interpersonal conception of personality to the 5-factor model and personality disorders.

  11. Camera calibration approach using circle-square-combined target

    Institute of Scientific and Technical Information of China (English)

    Fuqiang Zhou; Yexin Wang; Yi Cui; Haishu Tan

    2012-01-01

    Calibrating a small field camera is a challenging task because the traditional target with visible feature points that fit the limited space is difficult and costly to manufacture. We demonstrate a novel combined target used in camera calibration. The tangent points supplied by one circle located at the center of a square are used as invisible features, and the perspective projection invariance is proved. Both visible and invisible features extracted by the proposed feature extraction algorithm are used to solve the calibration. The target supplies a sufficient number of feature points to satisfy the requirements of calibration within a limited space. Experiments show that the approach can achieve high robustness and considerable accuracy. This approach has potential for computer vision applications particularly in small fields of view.%Calibrating a small field camera is a challenging task because the traditional target with visible feature points that fit the limited space is difficult and costly to manufacture.We demonstrate a novel combined target used in camera calibration.The tangent points supplied by one circle located at the center of a square are used as invisible features,and the perspective projection invariance is proved.Both visible and invisible features extracted by the proposed feature extraction algorithm are used to solve the calibration.The target supplies a sufficient number of feature points to satisfy the requirements of calibration within a limited space.Experiments show that the approach can achieve high robustness and considerable accuracy.This approach has potential for computer vision applications particularly in small fields of view.

  12. Diurnal and annual variations of meteor rates at the arctic circle

    Directory of Open Access Journals (Sweden)

    W. Singer

    2004-01-01

    Full Text Available Meteors are an important source for (a the metal atoms of the upper atmosphere metal layers and (b for condensation nuclei, the existence of which are a prerequisite for the formation of noctilucent cloud particles in the polar mesopause region. For a better understanding of these phenomena, it would be helpful to know accurately the annual and diurnal variations of meteor rates. So far, these rates have been little studied at polar latitudes. Therefore we have used the 33 MHz meteor radar of the ALOMAR observatory at 69° N to measure the meteor rates at this location for two full annual cycles. This site, being within 3° of the Arctic circle, offers in addition an interesting capability: The axis of its antenna field points (almost towards the North ecliptic pole once each day of the year. In this particular viewing direction, the radar monitors the meteoroid influx from (almost the entire ecliptic Northern hemisphere. We report on the observed diurnal variations (averaged over one month of meteor rates and their significant alterations throughout the year. The ratio of maximum over minimum meteor rates throughout one diurnal cycle is in January and February about 5, from April through December 2.3±0.3. If compared with similar measurements at mid-latitudes, our expectation, that the amplitude of the diurnal variation is to decrease towards the North pole, is not really borne out. Observations with the antenna axis pointing towards the North ecliptic pole showed that the rate of deposition of meteoric dust is substantially larger during the Arctic NLC season than the annual mean deposition rate. The daylight meteor showers of the Arietids, Zeta Perseids, and Beta Taurids supposedly contribute considerably to the June maximum of meteor rates. We note, though, that with the radar antenna pointing as described above, all three meteor radiants are close to the local horizon but all three radiants were detected.

  13. Health Literacy Study Circles[superscript +]. Introduction: Overview, Planning, and Facilitation Tips

    Science.gov (United States)

    Rudd, Rima; Soricone, Lisa; Santos, Maricel; Zobel, Emily; Smith, Janet

    2005-01-01

    A Health Literacy Study Circle[superscript +] is a multi-session professional development activity for adult education practitioners, conducted by a facilitator. All the information and materials required to conduct each Health Literacy Study Circle[superscript +] is presented in two parts: this Introduction and the "Facilitator's Guide" for each…

  14. Improving the Reading Attitudes of College Students: Using Literature Circles to Learn about Content Reading

    Science.gov (United States)

    Bernadowski, Carianne

    2013-01-01

    Literature circles and book clubs have become a popular instructional literacy strategy. In recent years, educators attempt to motivate students to read more in quantity and quality at an early age. A case study design was utilized that required undergraduate education majors to participate in literature circles reading historical fiction and…

  15. Schwarz’s lemma for the circle packings with the general combinatorics

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Rodin (1987) proved the Schwarz’s lemma analog for the circle packings based on the hexagonal combinatorics. In this paper, we prove the Schwarz’s lemma for the circle packings with the general combinatorics and our proof is more simpler than Rodin’s proof. At the same time, we obtain a rigidity property for those packings with the general combinatorics.

  16. Non-positively curved graph manifolds are virtually fibered over the circle

    OpenAIRE

    2001-01-01

    In this note we prove that any closed graph manifold admitting a metric of non-positive sectional curvature (NPC-metric) has a finite cover, which is fibered over the circle. An explicit criterion to have a finite cover, which is fibered over the circle, is presented for the graph manifolds of certain class.

  17. Sufficient Conditions for Dynamical Output Feedback Stabilization Via the Circle Criterion

    OpenAIRE

    2003-01-01

    This paper suggests sufficient conditions for asymptotically stable dynamical output feedback controller design based on the circle criterion. It is shown that a dynamic output feedback stabilization problem with impending problems of finite escape time, previously attacked by observer-based design, can be successfully solved using circle criterion design. Stability of the closed-loop system is global and robust to parameter uncertainty.

  18. When Two Circles Determine a Triangle. Discovering and Proving a Geometrical Condition in a Computer Environment

    Science.gov (United States)

    Metaxas, Nikolaos; Karagiannidou, Andromachi

    2010-01-01

    Visualization of mathematical relationships enables students to formulate conjectures as well as to search for mathematical arguments to support these conjectures. In this project students are asked to discover the sufficient and necessary condition so that two circles form the circumscribed and inscribed circle of a triangle and investigate how…

  19. The Revival of Research Circles: Meeting the Needs of Modern Aging and the Third Age

    Science.gov (United States)

    Ostlund, Britt

    2008-01-01

    This article provides evidence that it is worthwhile to reconsider the traditional research circle method as a means of involving people in the third age in fulfilling their needs to participate in learning activities and make their voices heard. The findings are based on three cases of research circles consistently driven by the interests of the…

  20. Laying the Groundwork for the Effective Implementation of Quality Circles in a Community College.

    Science.gov (United States)

    Ruff, Dan

    This five-part paper provides an overview of the use of quality circles as a participative management technique in community colleges. Section I offers an introduction to the technique, reviewing the history of quality circles from their development in Japan in the early 1960s to their introduction in American higher education in the early 1980s.…

  1. A surface containing a line and a circle through each point is a quadric

    KAUST Repository

    Nilov, Fedor K.

    2012-06-20

    We prove that a surface in 3-dimensional Euclidean space containing a line and a circle through each point is a quadric. We also give some particular results on the classification of surfaces containing several circles through each point. © 2012 Springer Science+Business Media B.V.

  2. Dynamic Investigation of Triangles Inscribed in a Circle, Which Tend to an Equilateral Triangle

    Science.gov (United States)

    Stupel, Moshe; Oxman, Victor; Sigler, Avi

    2017-01-01

    We present a geometrical investigation of the process of creating an infinite sequence of triangles inscribed in a circle, whose areas, perimeters and lengths of radii of the inscribed circles tend to a limit in a monotonous manner. First, using geometrical software, we investigate four theorems that represent interesting geometrical properties,…

  3. Circle Time: An Exploratory Study of Activities and Challenging Behavior in Head Start Classrooms

    Science.gov (United States)

    Zaghlawan, Hasan Y.; Ostrosky, Michaelene M.

    2011-01-01

    The purpose of this descriptive study was to examine circle time activities in eight Head Start classrooms. A total of 7 h of observations occurred in eight classrooms. Songs and academic activities were the most frequently occurring activities. Challenging behavior during circle time also was examined. The three activities with the highest…

  4. Comparing Interactions in Literature Circles in Both Online and in Class Discussions

    Science.gov (United States)

    Skeen, Christel Ghrist

    2014-01-01

    Discourse analysis of literature circles can lead educators to understand the different types of interactions taking place as students talk about text. Social and academic interactions exist in both face-to-face and online discussions of reading material. This study examines two different settings of literature circles and compares interactions of…

  5. Landslides: Geomorphology and Sea Cliff Hazard Potential, Santa Barbara - Isla Vista, California J.F. Klath and E.A. Keller

    Science.gov (United States)

    Klath, J. F.; Keller, E. A.

    2015-12-01

    Coastal areas are often characterized by high population densities in an ever changing, dynamic environment. The world's coasts are often dominated by steeply sloping sea cliffs, the morphology of which reflects rock type, wave erosion, and surface erosion, as well as human activities such changing vegetation, urban runoff, and construction of coastal defenses. The Santa Barbara and Goleta area, with over 17 km of sea cliffs and beaches, extends from Santa Barbara Point west to the hamlet of Isla Vista. A deeper understanding of the local geology and the physical processes generating slope failure and, thus, landward cliff retreat is important for general public safety, as well as future development and planning. Our research objective includes assessment of landslide hazard potential through investigation of previous landslides and how these events relate to various physical variables and characteristics within the surrounding bedrock. How does landslide frequency, volume, and type relate to varying local bedrock and structure? Two geologic formations dominate the sea cliffs of the Santa Barbara area: Monterey shale (upper, middle, and lower) and Monterey Sisquoc shale. Geology varies from hard cemented shale and diatomaceous, low specific gravity shale to compaction shale. Variations in landslide characteristics are linked closely to the geology of a specific site that affects how easily rock units are weathered and eroded by wave erosion, naturally occurring oil and water seeps, burnt shale events, and landslide type and frequency on steeply dipped bedding planes/daylighting beds. Naturally occurring features linked to human processes often weaken bedrock and, thus, increase the likelihood of landslides. We categorize landslide frequency, type, and triggers; location of beach access, drainage pipes, and water; and oil and tar seeps in order to develop suggestions to minimize landslide potential. Lastly, using previously published erosion cliff retreat rates and

  6. Detection probability of cliff-nesting raptors during helicopter and fixed-wing aircraft surveys in western Alaska

    Science.gov (United States)

    Booms, T.L.; Schempf, P.F.; McCaffery, B.J.; Lindberg, M.S.; Fuller, M.R.

    2010-01-01

    We conducted repeated aerial surveys for breeding cliff-nesting raptors on the Yukon Delta National Wildlife Refuge (YDNWR) in western Alaska to estimate detection probabilities of Gyrfalcons (Falco rusticolus), Golden Eagles (Aquila chrysaetos), Rough-legged Hawks (Buteo lagopus), and also Common Ravens (Corvus corax). Using the program PRESENCE, we modeled detection histories of each species based on single species occupancy modeling. We used different observers during four helicopter replicate surveys in the Kilbuck Mountains and five fixed-wing replicate surveys in the Ingakslugwat Hills near Bethel, AK. During helicopter surveys, Gyrfalcons had the highest detection probability estimate (p^;p^ 0.79; SE 0.05), followed by Golden Eagles (p^=0.68; SE 0.05), Common Ravens (p^=0.45; SE 0.17), and Rough-legged Hawks (p^=0.10; SE 0.11). Detection probabilities from fixed-wing aircraft in the Ingakslugwat Hills were similar to those from the helicopter in the Kilbuck Mountains for Gyrfalcons and Golden Eagles, but were higher for Common Ravens (p^=0.85; SE 0.06) and Rough-legged Hawks (p^=0.42; SE 0.07). Fixed-wing aircraft provided detection probability estimates and SEs in the Ingakslugwat Hills similar to or better than those from helicopter surveys in the Kilbucks and should be considered for future cliff-nesting raptor surveys where safe, low-altitude flight is possible. Overall, detection probability varied by observer experience and in some cases, by study area/aircraft type.

  7. New techniques to measure cliff change from historical oblique aerial photographs and structure-from-motion photogrammetry

    Science.gov (United States)

    Warrick, Jonathan; Ritchie, Andy; Adelman, Gabrielle; Adelman, Ken; Limber, Patrick W

    2017-01-01

    Oblique aerial photograph surveys are commonly used to document coastal landscapes. Here it is shown that adequate overlap may exist in these photographic records to develop topographic models with Structure-from-Motion (SfM) photogrammetric techniques. Using photographs of Fort Funston, California, from the California Coastal Records Project, imagery were combined with ground control points in a four-dimensional analysis that produced topographic point clouds of the study area’s cliffs for 5 years spanning 2002 to 2010. Uncertainty was assessed by comparing point clouds with airborne LIDAR data, and these uncertainties were related to the number and spatial distribution of ground control points used in the SfM analyses. With six or more ground control points, the root mean squared errors between the SfM and LIDAR data were less than 0.30 m (minimum 1⁄4 0.18 m), and the mean systematic error was less than 0.10 m. The SfM results had several benefits over traditional airborne LIDAR in that they included point coverage on vertical- to-overhanging sections of the cliff and resulted in 10–100 times greater point densities. Time series of the SfM results revealed topographic changes, including landslides, rock falls, and the erosion of landslide talus along the Fort Funston beach. Thus, it was concluded that SfM photogrammetric techniques with historical oblique photographs allow for the extraction of useful quantitative information for mapping coastal topography and measuring coastal change. The new techniques presented here are likely applicable to many photograph collections and problems in the earth sciences.

  8. NONMETALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>20102406 Chen Gang(China University of Geosciences,Beijing 100083,China);Li Fengming Discussion on Geological Characteristics and Genesis of Yuquanshan Graphite Deposit of Xinjiang(Xinjiang Geology,ISSN1000-8845,CN65-1092/P,27(4),2009,p.325-329,4 illus.,4 tables,5 refs.)Key words:graphite deposit,XinjiangYuquanshan graphite deposit of Xinjiang occurs in mica-quartz schist of Xingeer Information which belongs to Xinditate Group of Lower Pt in Kuluketage Block of Tarim paleo-continent,and experiences two mineralizing periods of

  9. Closed circle DNA algorithm of change positive-weighted Hamilton circuit problem

    Institute of Scientific and Technical Information of China (English)

    Zhou Kang; Tong Xiaojun; Xu Jin

    2009-01-01

    Chain length of closed circle DNA is equal. The same closed circle DNA's position corresponds to different recognition sequence, and the same recognition sequence corresponds to different foreign DNA segment, so closed circle DNA computing model is generalized. For change positive-weighted Hamilton circuit problem, closed circle DNA algorithm is put forward. First, three groups of DNA encoding are encoded for all arcs, and deck groups are designed for all vertices. All possible solutions axe composed. Then, the feasible solutions axe filtered out by using group detect experiment, and the optimization solutions are obtained by using group insert experiment and electrophoresis experiment. Finally, all optimization solutions are found by using detect experiment. Complexity of algorithm is concluded and validity of DNA algorithm is explained by an example. Three dominances of the closed circle DNA algorithm are analyzed, and characteristics and dominances of group delete experiment axe discussed.

  10. Migraine without aura is not associated with incomplete circle of Willis

    DEFF Research Database (Denmark)

    Ezzatian-Ahar, Shabnam; Amin, Faisal Mohammad; Obaid, Hayder Ghani

    2014-01-01

    BACKGROUND: The circle of Willis is an important source of collateral blood flow to maintain adequate cerebral perfusion, particularly in the posterior circulation. Some studies report a relationship between incomplete circle of Willis and migraine, whereas other studies show no difference between...... the prevalence of incomplete circle of Willis in migraineurs and controls. In the present study we compared the prevalence of incomplete circle of Willis in female migraine patients without aura to female healthy non-migraine controls.Using 3-Tesla magnetic resonance angiography we recorded three......-dimensional time-of-flight angiograms in 85 female participants (48 migraine patients without aura [median age 28 years] and 37 healthy controls [median age 25 years]). The images were subsequently analysed blindly by a neuroradiologist to detect incomplete circle of Willis. FINDINGS: We found no difference...

  11. A new method for fast circle detection in a complex background image

    Science.gov (United States)

    Wu, Meijun; Yang, Jie; Sun, Yadong

    2011-11-01

    A new method for circle detection, Hough gradient clustering method, has been developed in this paper. By using gradient direction angle to find the diameter of a circle, the new method can rapidly detect the circle in a complex background. The crucial steps in this method are the feature extraction and the clustering of the points which have the same gray direction angle and are collinear along the gradient direction. The application of the two-to-one space mapping and 1-2Hough transform can further reduce the useless calculation in the process of circle detection. Comparing with the Hough gradient method in OpenCV, the newly developed method shows a higher efficiency of circle detection in a complex background image as well as a great improvement in the anti-noise ability.

  12. NONMETALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>20140876 Gao Junbo(College of Resources and Environmental Engineering,Guizhou University,Guiyang 550025,China);Yang Ruidong Study on the Strontium Isotopic Composition of Large Devonian Barite Deposits from Zhenning,Guizhou Province(Geochimica,

  13. NONMETALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>20122457 Cai Jianshe ( Fujian Institute of Geological Survey and Drawing,Fuzhou 350011,China ) On the Geologic Characteristics and Genesis of the Longtangsi Fluorite Deposit in Pucheng County,Fujian Province ( Geology of Fujian,ISSN1001-3970,CN35-1080 / P,30 ( 4 ), 2011,p.301-306,3illus.,1table,6 refs.,with English abstract ) Key words:fluorspar deposit,Fujian Province

  14. Geologic map of the Gila Hot Springs 7.5' quadrangle and the Cliff Dwellings National Monument, Catron and Grant Counties, New Mexico

    Science.gov (United States)

    Ratté, James C.; Gaskill, David L.; Chappell, James R.

    2014-01-01

    The Gila Hot Springs quadrangle is of geologic interest with respect to four major features, which are: 1)\tThe caves of the Gila Cliff Dwellings National Monument 2)\tThe hot springs associated with the faults of the Gila Hot Springs graben 3)\tThe Alum Mountain rhyolite dome and eruptive center 4)\tA proposed segment of the southeastern wall of the Gila Cliff Dwellings caldera The Gila Cliff Dwellings National Monument consists of two tracts. The caves that were inhabited by the Mogollon people in the 14th century are in the main tract near the mouth of Cliff Dweller Canyon in the Little Turkey Park 7.5' quadrangle adjoining the northwest corner of the Gila Hot Springs quadrangle. The second tract includes the Cliff Dwellings National Monument Visitor Center at the confluence of the West and Middle Forks of the Gila River in the northwest corner of the Gila Hot Springs quadrangle. Both quadrangles are within the Gila National Forest and the Gila Wilderness except for a narrow corridor that provides access to the National Monument and the small ranching and residential community at Gila Center in the Gila River valley. The caves in Cliff Dweller Canyon were developed in the Gila Conglomerate of probable Miocene? and Pleistocene? age in this area by processes of lateral corrosion and spring sapping along the creek in Cliff Dweller Canyon. The hot springs in the Gila River valley are localized along faults in the deepest part of the Gila Hot Springs graben, which cuts diagonally northwest-southeast across the central part of the quadrangle. Some of the springs provide domestic hot water for space heating and agriculture in the Gila River valley and represent a possible thermal resource for development at the Cliff Dwellings National Monument. The Alum Mountain rhyolite dome and eruptive center in the southwestern part of the quadrangle is a colorful area of altered and mineralized rocks that is satellitic to the larger Copperas Canyon eruptive center, both being

  15. The role of Circle women in curbing violence against women and girls in Africa

    Directory of Open Access Journals (Sweden)

    Sylvia Owusu-Ansah

    2016-07-01

    Full Text Available The article looks at the role Circle of Concerned African Women Theologians (the Circle have played in the struggle to end or reduce the rate at which violence against women and girls occurs in West Africa by highlighting the contributions of older Circle women, especially the initiator of the Circle, Mercy Amba Oduyoye. The initiator of the Circle and other older Circle women have left a remarkable legacy that needs to continue by the current and future generations of the Circle. The background information examines the leadership and mentorship of Mercy Amba Oduyoye and the impact she has made in the lives of African women. The essay then looks at the types of violence that women face in West Africa with the specific contributions of Circle women in the struggle to end violence against women and girls. It then argues that Circle women have played very significant roles both in setting the pace and giving the platform for women activities to minimise gender-based violence against women and girls. Circle women have written and presented papers that have addressed many challenges including HIV and/or AIDS, Girl Child trafficking, Marriage of Minors, and almost all kinds of violence against women and girls. Currently, religious violence threatens the fabric of African nations causing insecurity and panic, women and girls being the most vulnerable. The challenge to the present and future Circle members is to contribute in significant ways towards religious harmony in Africa and beyond. The Circle acknowledges the leadership role of women and encourages them to spearhead the liberation of women as well as empower them to be able to aspire to get to the top or become independent. No one understands what someone else feels better than the person experiencing the ordeal. Women can better understand what they go through and also have the passion to strive towards liberation.Intradisciplinary and/or interdisciplinary implications: In this article, the

  16. NONMETALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20110947 Chen Xinglong(Guizhou Bureau of Nonferrous Metal and Nuclear Geology,Guiyang 550005,China);Gong Heqiang Endowment Factors and Development & Utilization Strategy of Bauxite Resource in North Guizhou Province(Guizhou Geology,ISSN1000-5943,CN52-1059/P,27(2),2010,p.106-110,6 refs.,with English abstract)Key words:bauxite deposit,Guizhou Province20110948 Dang Yanxia(Mineral Resource & Reservoir Evaluation Center,Urumiq 830000,China);Fan Wenjun Geological Features and a Primary Study of Metallogenesis of the Wucaiwang Zeolite Deposit,Fuyun County(Xinjiang Geology,ISSN1000-8845,CN65-1092/P,28(2),2010,p.167-170,2 illus.,1 table,5 refs.)Key words:zeolite deposit,Xinjiang Nearly all zeolite deposits in the world result from low-temperature-alteration of glass-bearing volcanic rocks.The southern slope of the Kalamali Mountain is one of the regions where medium to acid volcanics are major lithological type,thus it is a preferred area to look for zeolite deposit.The Wucaiwang zeolite ore district consists of mainly acid volcanic-clastic rocks.

  17. Kinetics of the forelimb in horses circling on different ground surfaces at the trot.

    Science.gov (United States)

    Chateau, Henry; Camus, Mathieu; Holden-Douilly, Laurène; Falala, Sylvain; Ravary, Bérangère; Vergari, Claudio; Lepley, Justine; Denoix, Jean-Marie; Pourcelot, Philippe; Crevier-Denoix, Nathalie

    2013-12-01

    Circling increases the expression of distal forelimb lameness in the horse, depending on rein, diameter and surface properties of the circle. However, there is limited information about the kinetics of horses trotting on circles. The aim of this study was to quantify ground reaction force (GRF) and moments in the inside and outside forelimb of horses trotting on circles and to compare the results obtained on different ground surfaces. The right front hoof of six horses was equipped with a dynamometric horseshoe, allowing the measurement of 3-dimensional GRF, moments and trajectory of the centre of pressure. The horses were lunged at slow trot (3 m/s) on right and left 4 m radius circles on asphalt and on a fibre sand surface. During circling, the inside forelimb produced a smaller peak vertical force and the stance phase was longer in comparison with the outside forelimb. Both right and left circling produced a substantial transversal force directed outwards. On a soft surface (sand fibre), the peak transversal force and moments around the longitudinal and vertical axes of the hoof were significantly decreased in comparison with a hard surface (asphalt). Sinking of the lateral or medial part of the hoof in a more compliant surface enables reallocation of part of the transversal force into a proximo-distal force, aligned with the limb axis, thus limiting extrasagittal stress on the joints.

  18. Surface kinematics of periglacial sorted circles using Structure-from-Motion technology

    Directory of Open Access Journals (Sweden)

    A. Kääb

    2013-12-01

    Full Text Available Sorted soil circles are a conspicuous form of periglacial patterned ground. Numerical modelling suggests that these features develop from a convection-like circulation of material in the active layer of permafrost. The related iterative burying and resurfacing of material is believed to play an important role in the soil carbon cycle of high latitudes. The connection of sorted circles to permafrost conditions and its changes over time make these ground forms to a potential paleoclimatic indicator. In this study we apply the photogrammetric Structure-from-Motion technology (SfM to large sets of overlapping terrestrial photos taken in Augusts 2007 and 2010 over three sorted circles at Kvadehuksletta, Western Spitsbergen. We retrieve repeat digital elevation models (DEMs and orthoimages with millimetre-resolution and accuracy. Changes in microrelief over the three years are obtained from DEM-differencing and horizontal displacement fields from tracking features between the orthoimages. In the inner domains of the circles, consisting of fines, material moves radially outside with horizontal surface speeds of up to 2 cm yr−1. The outer circle ridges consist of coarse stones that displace towards the inner circle domain at similar rates. A number of substantial deviations from this overall radial symmetry, both in horizontal displacements and in microrelief, shed new light on the potential spatio-temporal evolution of sorted soil circles, and periglacial patterned ground in general.

  19. Taking a literature circles approach to teach Academic English

    Directory of Open Access Journals (Sweden)

    Graham-Marr Alastair

    2016-01-01

    Full Text Available Literature circles (LC, an activity framework for classroom discussion, has been adapted for EFL classes to help students engage more deeply with reading texts. In this approach, students read texts outside of class, and discuss the texts in class, using a specified discussion framework. Originally developed for L1 classes as a tool for teaching literature, LC has been adapted for EFL classes, not only to help develop reading skills, but also to help students develop their discussion skills. However, to date, many adaptations of LC have relied on graded fiction as source material, which is not always appropriate for tertiary education. Feeling pressure to match course content with the labour market needs of our contemporary global society, English departments are increasingly being asked to include more academic content in their classes. This requires that non-fiction be used as source material. This preliminary study examines student perceptions of an LC class using non-fiction as source material. The subjects of this short, qualitative, pilot study were engineering students at a university in Japan. Procedures of the class and the issues that emerged are discussed.

  20. Using great circles to understand motion on a rotating sphere

    Science.gov (United States)

    McIntyre, D. H.

    2000-12-01

    Motion observed in a rotating frame of reference is generally explained by invoking inertial forces. While this approach simplifies some problems, there is often little physical insight into the motion, in particular into the effects of the Coriolis force. To aid in the understanding of three-dimensional inertial forces, motion on a rotating sphere is considered from the points of view of an inertial observer and of an observer fixed on the sphere. The inertial observer observes the motion to be along a great circle fixed in the inertial frame, in analogy with simple straight-line motion in the two-dimensional case. This simple "straight-line" viewpoint of the inertial observer is reconciled qualitatively and quantitatively with the view of the rotating observer that requires inertial forces in order to account for the motion. Through a succession of simple examples, the Coriolis and centrifugal effects are isolated and illustrated, as well as effects due to the curvilinear nature of motion on a sphere.

  1. Vienna Circle and Logical Analysis of Relativity Theory

    CERN Document Server

    Andréka, H; Németi, I; Németi, P; Székely, G

    2011-01-01

    In this paper we present some of our school's results in the area of building up relativity theory (RT) as a hierarchy of theories in the sense of logic. We use plain first-order logic (FOL) as in the foundation of mathematics (FOM) and we build on experience gained in FOM. The main aims of our school are the following: We want to base the theory on simple, unambiguous axioms with clear meanings. It should be absolutely understandable for any reader what the axioms say and the reader can decide about each axiom whether he likes it. The theory should be built up from these axioms in a straightforward, logical manner. We want to provide an analysis of the logical structure of the theory. We investigate which axioms are needed for which predictions of RT. We want to make RT more transparent logically, easier to understand, easier to change, modular, and easier to teach. We want to obtain deeper understanding of RT. Our work can be considered as a case-study showing that the Vienna Circle's (VC) approach to doing...

  2. End of the line to build a circle

    CERN Multimedia

    2006-01-01

    The installation of the cryogenic distribution line in the LHC tunnel is finally finished! All the sectors have undergone pressure and helium leak tests at room temperature, and one complete sector was cold tested in cryogenic conditions. Some of the QRL team in UJ22 of the LHC tunnel, where the last sector of the cryogenic distribution line was installed.It must have been a joyous moment in UJ22 of the LHC tunnel (near Point 2, Saint Genis Pouilly) on 19 October. This was where the last external weld of the cryogenic distribution line, also known as QRL, was made, thus completing the full distribution ring. The QRL is a circle built in 8 sectors, each approximately 3 km in length. It will circulate helium in liquid and gas phases, at different temperatures and pressures, to provide the cryogenic conditions for the superconducting magnets in the LHC tunnel. The last sector installed (sector 1-2) passed the pressure and helium leak tests at room temperature on 28 October. As part of the warm test, each sector...

  3. METALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>20091594 Bao Yafan(The Third Geologic Survey of Jilin Province,Siping 136000,China);Liu Yanjun Relations between Bashenerxi Granite,West Dongkunlun and Baiganhu Tungsten-Tin Deposit(Jilin Geology,ISSN1001-2427,CN22-1099/P,27(3),2008,p.56-59,67,5 illus.,2 tables,7 refs.,with English abstract)Key words:tungsten ores,tin ores,monzogranite,Kunlun Mountains20091595 Chen Fuwen(Yichang Institute of Geology and Mineral Resources,China Geological Survey,Yichang 443003,China);Dai Pingyun Metallogenetic and Isotopic Chronological Study on the Shenjiaya Gold Deposit in Xuefeng Mountains,Hunan Province(Acta Geologica Sinica,ISSN0001-5717,CN11-1951/P,82(7),2008,p.906-911,3 illus.,2 tables,30 refs.)Key words:gold ores,HunanThe Shenjiaya gold deposit is a representative one

  4. Topography of arterial circle of the brain in Egyptian spiny mouse (Acomys cahirinus, Desmarest).

    Science.gov (United States)

    Szczurkowski, A; Kuchinka, J; Nowak, E; Kuder, T

    2007-04-01

    Using stained acryl latex-injected techniques, the arterial circle of the brain in Acomys cahirinus Desmarest was studied. Results revealed an important individual variability of investigated structure. Three morphological variants were found: (1) the lack of typical arterial circle--opened in front and the back side, (2) partial opened at the back side, (3) completely closed arterial circle. This finding is opposed to many species of mammals, including rodents, and especially laboratory mouse. In our point of view, it seems to be a specific character.

  5. Constructing knowledge about the trigonometric functions and their geometric meaning on the unit circle

    Science.gov (United States)

    Altman, Renana; Kidron, Ivy

    2016-10-01

    Processes of knowledge construction are investigated. A learner is constructing knowledge about the trigonometric functions and their geometric meaning on the unit circle. The analysis is based on the dynamically nested epistemic action model for abstraction in context. Different tasks are offered to the learner. In his effort to perform the different tasks, he has the opportunity to understand the process used to create unit circle representations of trigonometric expressions. The theoretical framework of abstraction in context is used to analyse the evolution of the learner's construction of knowledge in the transition from 'triangle' trigonometry to 'circle' trigonometry.

  6. METALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20111705 An Junbo(Team 603,Bureau of Nonferrous Metals Geological Exploration of Jilin Province,Hunchun 133300,China);Xu Renjie Geological Features and Ore Genesis of Baishilazi Scheelite Deposit in Yanbian Area(Jilin Geology,ISSN1001-2427,CN22-1099/P,29(3),2010,p.39-43,2 illus.,2 tables,7 refs.)Key words:tungsten ores,Jilin ProvinceThe Baishilazi scheelite deposit is located in contacting zone between the marble of the Late Palaeozoic Qinglongcun Group and the Hercynian biotite granite.The vein and lenticular major ore body is obviously controlled by NE-extending faults and con

  7. Hydrogeology of the Pictured Cliffs Sandstone in the San Juan structural basin, New Mexico, Colorado, Arizona, and Utah

    Science.gov (United States)

    Dam, William L.; Kernodle, J.M.; Thorn, C.R.; Levings, G.W.; Craigg, S.D.

    1990-01-01

    This report is one in a series resulting from the U.S. Geological Survey's Regional Aquifer System Analysis (RASA) study of the San Juan structural basin that began in October 1984. The purposes of the study (Welder, 1986) are to: (1) Define and evaluate the aquifer system; (2) assess the effects of past, present, and potential ground-water use on aquifers and streams, and (3) determine the availability and quality of ground water. Previous reports in this series describe the hydrogeology of the Dakota Sandstone (Craigg and others, 1989), Gallup Sandstone (Kernodle and others, 1989), Morrison Formation (Dam and others, 1990), Point Lookout Sandstone (Craigg and others, 1990), Kirtland Shale and Fruitland Formation (Kernodle and others, 1990), Menefee Formation (Levings and others, 1990), Cliff House Sandstone (Thorn and others, 1990), and Ojo Alamo Sandstone (Thorn and others, 1990) in the San Juan structural basin. This report summarizes information on the geology and the occurrence and quality of water in the Pictured Cliffs Sandstone, one of the primary water-bearing units in the regional aquifer system. Data used in this report were collected during the RASA study or derived from existing records in the U.S. Geological Survey's computerized National Water Information System (NWIS) data base, the Petroleum Information Corporation's data base, and the Dwight's ENERGYDATA Inc. BRIN database. Although all data available for the Pictured Cliffs Sandstone were considered in formulating the discussions in the text, not all those data could be plotted on the illustrations. The San Juan structural basin in New Mexico, Colorado, Arizona, and Utah has an area of about 21,600 square miles (fig. 1). The structural basin is about 140 miles wide and about 200 miles long. The study area is that part of the structural basin that contains rocks of Triassic and younger age; therefore, the study area is less extensive than the structural basin. Triassic through Tertiary

  8. CoSMoS (Coastal Storm Modeling System) Southern California v3.0 Phase 2 projections of coastal cliff retreat due to 21st century sea-level rise

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Summary: This dataset contains projections of coastal cliff-retreat rates and positions for future scenarios of sea-level rise (SLR). Projections were made using...

  9. 52例坠崖自杀案例分析%Fifty-two Cases Analysis of Cliff Suicide

    Institute of Scientific and Technical Information of China (English)

    宋玉勇; 王剑; 邾立庆

    2015-01-01

    Objective To analyze suicide scene, damage morphology and case investigation of mountain type scenic spot for giving the references to determine the nature of cliff suicide cases. Methods The suicide cases collected from 2002 to 2012 in scenic spot of Mount Huangshan. The age, gender, native place, case location, damage inspection and behavior were analyzed. Results In the 52 suicide cases, the suicide rate of male was higher than that of female. The numbers from other provinces were higher than that of local province. The age was mainly range from 19 to 50. The time of suicide cases mostly happened between 16:00 to 24:00. The major damage was compound injury with varying degrees of traumatic brain injury, organic injury of pleuroperitoneal cavity and surface bruise and scratch. Conclu-sion In order to determine the nature of cliff suicide cases, it needs to work synthetically in the investi-gation of crime scene and interview.%目的:通过对山岳型景区高坠自杀案件的现场分析、损伤形态及案情调查情况进行分析,为高坠死亡案件的定性提供参考。方法收集52例黄山景区2002—2012年内坠崖自杀案例的资料,从年龄、性别、籍贯、事发时段、坠落地点、损伤检验、行为方式等方面进行分析。结果52例坠崖自杀案例中,男性的自杀率明显高于女性,外省籍比例明显高于本省籍,年龄分布于19~50岁,案发时间段多在16:00~24:00,损伤形态以复合伤为主,均不同程度伴有颅脑损伤、胸腹腔器官损伤及体表划擦伤。结论高坠死亡案件的定性需要进行现场勘验、案情调查走访等综合分析。

  10. Accurate 3D point cloud comparison and volumetric change analysis of Terrestrial Laser Scan data in a hard rock coastal cliff environment

    Science.gov (United States)

    Earlie, C. S.; Masselink, G.; Russell, P.; Shail, R.; Kingston, K.

    2013-12-01

    Our understanding of the evolution of hard rock coastlines is limited due to the episodic nature and ';slow' rate at which changes occur. High-resolution surveying techniques, such as Terrestrial Laser Scanning (TLS), have just begun to be adopted as a method of obtaining detailed point cloud data to monitor topographical changes over short periods of time (weeks to months). However, the difficulties involved in comparing consecutive point cloud data sets in a complex three-dimensional plane, such as occlusion due to surface roughness and positioning of data capture point as a result of a consistently changing environment (a beach profile), mean that comparing data sets can lead to errors in the region of 10 - 20 cm. Meshing techniques are often used for point cloud data analysis for simple surfaces, but in surfaces such as rocky cliff faces, this technique has been found to be ineffective. Recession rates of hard rock coastlines in the UK are typically determined using aerial photography or airborne LiDAR data, yet the detail of the important changes occurring to the cliff face and toe are missed using such techniques. In this study we apply an algorithm (M3C2 - Multiscale Model to Model Cloud Comparison), initially developed for analysing fluvial morphological change, that directly compares point to point cloud data using surface normals that are consistent with surface roughness and measure the change that occurs along the normal direction (Lague et al., 2013). The surfaces changes are analysed using a set of user defined scales based on surface roughness and registration error. Once the correct parameters are defined, the volumetric cliff face changes are calculated by integrating the mean distance between the point clouds. The analysis has been undertaken at two hard rock sites identified for their active erosion located on the UK's south west peninsular at Porthleven in south west Cornwall and Godrevy in north Cornwall. Alongside TLS point cloud data, in

  11. METALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>20090243 Chen Zhibin (Hebei Institute of Geological Survey, Shijiazhuang 050081, China) Ore-Controlling Factors of the Beichagoumen Ag-Polymetallic Deposits in Northern Hebei Province (Geological Survey and Research, ISSN1672-4135, CN12-1353/P, 31(1), 2008, p.1-5, 3 illus., 10 refs.)

  12. METALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>20131565 Cai Lianyou(No.332 Geological Team,Bureau of Geology and Mineral Resources Exploration of Anhui Province,Huangshan 245000,China);Weng Wangfei Geological Characteristics and Genesis Analysis of Guocun Navajoite Deposit in South Anhui Province(Mineral Resources and Geology,

  13. METALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>20102341 Bao Peisheng(Institute of Geology,Chinese Academy of Geological Science,Beijing 100037,China)Further Discussion on the Genesis of the Podiform Chromite Deposits in the Ophiolites-Questioning about the Rock:Melt Interaction Metallogeny(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,28(12),2009,p.1741-1761

  14. NONMETALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>20131601 Gao Junbo(College of Resources and Environmental Engineering,Guizhou University,Guiyang 550003,China);Yang Ruidong Hydrothermal Venting-Flowing Sedimentation Characteristics of Devonian Barite Deposits from Leji,Zhenning County,Guizhou Province(Acta Sedimentologica Sinica,ISSN1000-0550,CN62-1038/P,30(3),

  15. Vibration characteristic analysis method for the quartz microgyroscope based on the admittance circle

    Science.gov (United States)

    Wang, Haoxu; Dong, Peitao; Xie, Liqiang; Wu, Xuezhong

    2014-03-01

    The vibration characteristic analysis method for a quartz microgyroscope based on the admittance circle is reported in this paper. Admittance theory is introduced and the admittance circle principle is analysed to study the vibration characteristics of the quartz microgyroscope. The prototype gyroscope was fabricated by micro-electromechanical systems (MEMS) technology. The admittance and phase diagram of the work mode were obtained by vibration mode test systems. Then the admittance circle of the work mode was drawn, and the parameter identification of the transfer function between the voltage and current was completed to analyse the vibration characteristics. Therefore, the vibration characteristic analysis method based on the admittance circle can be used to build the transfer function of the quartz microgyroscope, which is helpful for the design of a high performance quartz microgyroscope.

  16. Vibration characteristic analysis method for the quartz microgyroscope based on the admittance circle

    Directory of Open Access Journals (Sweden)

    Haoxu Wang

    2014-02-01

    Full Text Available The vibration characteristic analysis method for a quartz microgyroscope based on the admittance circle is reported in this paper. Admittance theory is introduced and the admittance circle principle is analysed to study the vibration characteristics of the quartz microgyroscope. The prototype gyroscope was fabricated by micro-electromechanical systems (MEMS technology. The admittance and phase diagram of the work mode were obtained by vibration mode test systems. Then the admittance circle of the work mode was drawn, and the parameter identification of the transfer function between the voltage and current was completed to analyse the vibration characteristics. Therefore, the vibration characteristic analysis method based on the admittance circle can be used to build the transfer function of the quartz microgyroscope, which is helpful for the design of a high performance quartz microgyroscope.

  17. Approximating the Euclidean circle in the square grid using neighbourhood sequences

    CERN Document Server

    Farkas, Janos; Nagy, Benedek

    2010-01-01

    Distance measuring is a very important task in digital geometry and digital image processing. Due to our natural approach to geometry we think of the set of points that are equally far from a given point as a Euclidean circle. Using the classical neighbourhood relations on digital grids, we get circles that greatly differ from the Euclidean circle. In this paper we examine different methods of approximating the Euclidean circle in the square grid, considering the possible motivations as well. We compare the perimeter-, area-, curve- and noncompactness-based approximations and examine their realization using neighbourhood sequences. We also provide a table which summarizes our results, and can be used when developing applications that support neighbourhood sequences.

  18. Geologic Provinces of the Circum-Arctic, 2008 (north of the Arctic Circle)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This shapefile includes arcs and polygons that describe U.S. Geological Survey defined 33 geologic provinces of the Circum-Arctic (north of the Arctic Circle). Each...

  19. Endonuclease-rolling circle amplification-based method for sensitive analysis of DNA-binding protein

    Institute of Scientific and Technical Information of China (English)

    Min Li Li; Dong Rui Zhou; Hong Zhao; Jin Ke Wang; Zu Hong Lu

    2009-01-01

    A sensitive approach for the qualitative detection of DNA-binding protein on the microarray was developed. DNA complexes in which a partial duplex region is formed from a biotin-primer and a circle single strand DNA (ssDNA) were spotted on a microarray. The endonuclease recognition site (ERS) and the DNA-binding sites (DBS) were arranged side by side within the duplex region. The working principle of the detection system is described as follows: when the DNA-binding protein capture the DBS, the endonuclease could not attach to the ERS, and the immobilized primer in the DNA complex could be extended along the circle ssDNA by rolling circle amplification (RCA). When no protein protects the DBS, the ERS could be attacked by the endonuclease and subsequently no rolling circle amplification occurs. Thereby we can detect the sequence specific DNA-binding activity with high-sensitivity due to the signal amplification of RCA.

  20. Antarctic Mirabilite Mounds as Mars Analogs: The Lewis Cliffs Ice Tongue Revisited

    Science.gov (United States)

    Socki, Richard A.; Sun, Tao; Niles, Paul B.; Harvey, Ralph P.; Bish, David L.; Tonui, Eric

    2012-01-01

    It has been proposed, based on geomorphic and geochemical arguments, that subsurface water has played an important role in the history of water on the planet Mars [1]. Subsurface water, if present, could provide a protected and long lived environment for potential life. Discovery of gullies [2] and recurring slopes [3] on Mars suggest the potential for subsurface liquid water or brines. Recent attention has also focused on small (Tongue (LCIT) [6] in the Transantarctic Mountains, Antarctica, and are potential terrestrial analogs for mounds observed on the martian surface. The following characteristics distinguish LCIT evaporite mounds from other evaporite mounds found in Antarctic coastal environments and/or the McMurdo Dry Valleys: (1) much greater distance from the open ocean (approx.500 km); (2) higher elevation (approx.2200 meters); and (3) colder average annual temperature (average annual temperature = -30 C for LCIT [7] vs. 20 C at sea level in the McMurdo region [8]. Furthermore, the recent detection of subsurface water ice (inferred as debris-covered glacial ice) by the Mars Reconnaissance Orbiter [9] supports the use of an Antarctic glacial environment, particularly with respect to the mirabilite deposits described in this work, as an ideal terrestrial analog for understanding the geochemistry associated with near-surface martian processes. S and O isotopic compositions.

  1. Twistor quantization of the space of half-differentiable vector functions on the circle revisited

    Institute of Scientific and Technical Information of China (English)

    SERGEEV; Armen

    2009-01-01

    We discuss the twistor quantization problem for the classical system(Vd,Ad),represented by the phase space Vd,identified with the Sobolev space H 1/2 0 (S1,Rd)of half-differentiable vector functions on the circle,and the algebra of observables Ad,identified with the semi-direct product of the Heisenberg algebra of Vd and the algebra Vect(S1)of tangent vector fields on the circle.

  2. A robust circle criterion observer with application to neural mass models

    OpenAIRE

    2012-01-01

    International audience; A robust circle criterion observer is designed and applied to neural mass models. At present, no existing circle criterion observers apply to the considered models, i.e. the required linear matrix inequality is infeasible. Therefore, we generalise available results to derive a suitable estimation algorithm. Additionally, the design also takes into account input uncertainty and measurement noise. We show how to apply the observer to estimate the mean membrane potential ...

  3. Circle drawing as evaluative movement task in stroke rehabilitation: an explorative study

    Directory of Open Access Journals (Sweden)

    Rietman Johan S

    2011-03-01

    Full Text Available Abstract Background The majority of stroke survivors have to cope with deficits in arm function, which is often measured with subjective clinical scales. The objective of this study is to examine whether circle drawing metrics are suitable objective outcome measures for measuring upper extremity function of stroke survivors. Methods Stroke survivors (n = 16 and healthy subjects (n = 20 drew circles, as big and as round as possible, above a table top. Joint angles and positions were measured. Circle area and roundness were calculated, and synergistic movement patterns were identified based on simultaneous changes of the elevation angle and elbow angle. Results Stroke survivors had statistically significant lower values for circle area, roundness and joint excursions, compared to healthy subjects. Stroke survivors moved significantly more within synergistic movement patterns, compared to healthy subjects. Strong correlations between the proximal upper extremity part of the Fugl-Meyer scale and circle area, roundness, joint excursions and the use of synergistic movement patterns were found. Conclusions The present study showed statistically significant differences in circle area, roundness and the use of synergistic movement patterns between healthy subjects and stroke survivors. These circle metrics are strongly correlated to stroke severity, as indicated by the proximal upper extremity part of the FM score. In clinical practice, circle area and roundness can give useful objective information regarding arm function of stroke survivors. In a research setting, outcome measures addressing the occurrence of synergistic movement patterns can help to increase understanding of mechanisms involved in restoration of post stroke upper extremity function.

  4. Occlusion of the circle of Willis. Diagnosis by 3D-time of flight MR angiography

    Energy Technology Data Exchange (ETDEWEB)

    Komatsumoto, Satoru; Ushioda, Takakazu; Nara, Masaharu [Ashikaga Red Cross Hospital, Tochigi (Japan)

    1996-08-01

    Magnetic resonance angiograms (MRA) were studied in 7 cases of occlusion of the circle of Willis. MRA successfully demonstrated the vascular obstructions and moyamoya vessels with a positive correlation to the angiographic findings. Leptomeningeal and transdural collateral vessels were also identified with MRA. As MRA is not invasive, it promises to become a valuable alternature to conventional angiography in the diagnosis of occlusion of the circle of Willis. (author)

  5. A RETRAN model of the Calvert Cliffs-1 pressurized water reactor for assessing the safety implications of control systems

    Energy Technology Data Exchange (ETDEWEB)

    Renier, J P.A.; Smith, O L

    1987-03-01

    The failure mode and effects analysis of Calvert Cliffs-1 identified sequences of events judged sufficiently complex to merit further analysis in detailed dynamic simulations. This report describes the RETRAN model developed for this purpose and the results obtained. The mathematical tool was RETRAN2/Mod3, the latest version of a widely used and extensively validated thermal-hydraulics production code obtained by license agreement with the developer, Electric Power Research Institute, and installed on the ORNL BM-3033 computers. RETRAN2 is based on a first-principles methodology that treats two-phase flow with slip. Thermal equilibrium of phases is assumed except in the pressurizer, where non-equilibrium processes are important and special methodology is used. Heat transfer in solids is obtained from the conventional conduction equation. Point or 1-D kinetics is available for the reactor core. The fundamental methodology is supplemented with a broad list of process submodels that calculate heat transfer coefficients, fluid and metal state properties, choked flow, form and wall friction losses, and other parameters. Also supplied are component submodels for various types of valves and pumps, the latter of which incorporate four-quadrant characteristics for components in which two-phase or reverse flow may be expected, and head versus flow curves for others. Extensive input allows the code to be highly particularized to a specific plant. The major investment in time and manpower occurs in setting up the base case; changes are comparatively easy to implement.

  6. The impact of rotary lobe blower seal upgrades at INCO's Copper Cliff Nickel Refinery

    Energy Technology Data Exchange (ETDEWEB)

    Corless, C; Costigan, J. [INCO Copper Cliff Nickel Refinery, Copper Cliff, ON (Canada)

    2000-10-01

    INCO's Pressure Carbonyl (IPC) plant at Copper Cliff is unique in the world in that it utilizes the same basic chemistry, but forms the nickel carbonyl at high pressure to accelerate the reaction and utilize less pure refinery feeds. Two main process gases are used, namely carbon monoxide and nickel carbonyl which are transported throughout the plant using various compressors and blowers depending on whether the gas is at high pressure or at low pressure. The high-pressure transport is accomplished by three five-stage reciprocating compressors. There are numerous low pressure gas blowers; all of them must have seals to ensure that the gas does not escape into the plant atmosphere, and just as importantly, to prevent the lubricating oil from entering the process gases. This paper describes an incident in 1997 when Castrol R40, a lubricant, entered the IPC plant carrier gas stream, adversely affecting equipment availability and process control. The main source of the Castrol R40 was determined to be the carrier gas and low pressure gas blowers. The entry of Castrol R40 into the carrier gas stream was successfully prevented when the mechanical shaft seals were replaced with Ferrofluidics seals. Details of the resulting new sealing arrangements, the status of blower upgrade project and results achieved to date are reviewed.

  7. Think crisis-think female: the glass cliff and contextual variation in the think manager-think male stereotype.

    Science.gov (United States)

    Ryan, Michelle K; Haslam, S Alexander; Hersby, Mette D; Bongiorno, Renata

    2011-05-01

    The "think manager-think male" (TMTM) association underlies many gender inequalities in the workplace. However, research into the "glass cliff" has demonstrated that the suitability of male and female managers varies as a function of company performance such that in times of poor performance people may "think female" (Ryan & Haslam, 2005, 2007). Three studies examined gender and managerial stereotypes in the context of companies that are doing well or doing badly. Study 1 reproduced TMTM associations for descriptions of managers of successful companies but demonstrated a reversal for managers of unsuccessful companies. Study 2 examined the prescriptive nature of these stereotypes. No TMTM relationship was found for ideal managers of successful companies, but ideal managers of unsuccessful companies were associated with the female stereotype. Study 3 suggested that women may be favored in times of poor performance, not because they are expected to improve the situation, but because they are seen to be good people managers and can take the blame for organizational failure. Together, the studies illustrate the importance of context as a moderator of the TMTM association. Practical and theoretical implications for gender discrimination in the workplace are discussed.

  8. Diurnal and annual variations of meteor rates at the Arctic circle

    Directory of Open Access Journals (Sweden)

    W. Singer

    2004-01-01

    Full Text Available Meteors are an important source for (a the metal atoms of the upper atmosphere metal layers and (b for condensation nuclei, the existence of which are a prerequisite for the formation of noctilucent cloud particles in the polar mesopause region. For a better understanding of these phenomena, it would be helpful to know accurately the annual and diurnal variations of meteor rates. So far, these rates have been little studied at polar latitudes. Therefore we have used the 33 MHz meteor radar of the ALOMAR observatory at 69° N to measure the meteor rates at this location for two full annual cycles. This site, being within 3° of the Arctic circle, offers in addition an interesting capability: The axis of its antenna field points (almost towards the North ecliptic pole once each day of the year. In this particular viewing direction, the radar monitors the meteoroid influx from (almost the entire ecliptic Northern hemisphere.

    We report on the observed diurnal variations (averaged over one month of meteor rates and their significant alterations throughout the year. The ratio of maximum over minimum meteor rates throughout one diurnal cycle is in January and February about 5, from April through December 2.3±0.3. If compared with similar measurements at mid-latitudes, our expectation, that the amplitude of the diurnal variation is to decrease towards the North pole, is not really borne out.

    Observations with the antenna axis pointing towards the North ecliptic pole showed that the rate of deposition of meteoric dust is substantially larger during the Arctic NLC season than the annual mean deposition rate. The daylight meteor showers of the Arietids, Zeta Perseids, and Beta Taurids supposedly contribute considerably to the June maximum of meteor rates. We note, though, that with the radar antenna pointing as described above, all three meteor radiants are close to the local horizon. This radiant location should cause most of these

  9. PID comes full circle: Applications of V(DJ recombination excision circles in research, diagnostics and newborn screening of primary immunodeficiency disorders

    Directory of Open Access Journals (Sweden)

    Menno C. Van Zelm

    2011-05-01

    Full Text Available The vast majority of patients suffering from a primary immunodeficiency (PID have defects in their T- and/or B-cell compartments. Despite advances in molecular diagnostics, in many patients no underlying genetic defect has been identified. B- and T-lymphocytes are unique in their ability to create a receptor by genomic rearrangement of their antigen receptor genes via V(DJ recombination. During this process, stable circular excision products are formed that do not replicate when the cell proliferates. Excision circles can be reliably quantified using real-time quantitative (RQ-PCR techniques. Frequently occurring δREC–ψJα T-cell receptor excision circles (TRECs have been used to assess thymic output and intronRSS–Kde recombination excision circles (KREC to quantify B-cell replication history. In this perspective, we describe how TRECs and KRECs are formed during precursor- T and B cell differentiation, respectively. Furthermore, we discuss new insights obtained with TRECs and KRECs and specifically how these excision circles can be applied to support therapy monitoring, patient classification and newborn screening of PID.

  10. Introspection, empathy, and the semi-circle of mental health.

    Science.gov (United States)

    Kohut, H

    1982-01-01

    Written shortly before his death, Heinz Kohut's last paper opens with a discussion of the paper 'Introspection, empathy, and psychoanalysis', written in 1959, which he presented at the Twenty-fifth Anniversary Meeting of the Chicago Institute for Psychoanalysis. In his first essay on the role of empathy in psychoanalysis, an essay that according to Kohut provided a foundation for many of his subsequent investigations in the field of depth psychology, he advanced the thesis that the introspective-empathic stance of the observer defines the science of psychoanalysis. The author explains that he was moved to propose this operational definition of psychoanalysis twenty-five years before because he felt that the introduction of the psychobiological concept of the drives (as well as various social psychological concepts) had not led to a true integration of psychoanalysis with biology or medicine but to a psychological and moral view of 'Guilty Man' that worked to distort the analyst's perception in the clinical and applied field. Kohut asserts that by defining itself operationally, psychoanalysis can accept itself as psychology, a psychology that studies man in terms of a self attempting to realize the programme laid down in his depth during the span of his life. The final section of the paper is devoted to a re-examination of man's intergenerational relationships in light of the shift Kohut advocates from psychobiology to psychology. The Oedipus complex is not to be understood as the end product of the uninfluentiable conflict of basic opposing instincts but as the result of interferences that impinge on man's development. Acknowledging the mythic power of Freud's formulation of the Oedipus complex, the author offers a dose of mythical counter-magic (to which the 'semi-circle of mental health' in the paper's title refers) and a re-interpretation of the story of King Oedipus. Kohut believes that the essence of human experience is not to be found in the biologically

  11. Anatomical Variations of the Circle of Willis in Males and Females on 3D MR Angiograms

    Directory of Open Access Journals (Sweden)

    Kawther A. Hafez, Nahla M. Afifi, Fardous Z. Saudi

    2007-03-01

    Full Text Available Objective: The objective of the present work was to study the anatomical variations of the circle of Willis as regard its component vessels and their average diameters in a sample of adult Egyptians and to detect any sex-related differences in these variations. Material and Methods: One hundred and twenty adult patients were observed (60 males and 60 females. They all had problems unrelated to any ischemic or vascular diseases, so they were considered as healthy control, concerning the morphology of the circle of Willis. In addition, ten cadavers' brains were obtained from the Anatomy department, Faculty of Medicine Ain Shams University for examination of the circle of Willis and for detection of any variations. Results: The anatomical variations of the anterior part, posterior part and completeness of the circle were inspected. Also, the diameters of all component vessels were assessed. The results indicated that, the anterior part of the circle was completed in 70% males and 75% females of the study sample. No statistically significant difference was detected between sexes. The most common variant of the anterior part was the single anterior communicating artery followed by the hypoplastic or absent anterior communicating artery. The posterior part of the circle was completed in 44% males and 58% females. The most common variant was the bilateral posterior communicating arteries, followed by the unilateral posterior communicating artery. An entirely complete circle was found only in 45% of the entire population; and it was higher in the females than the in males. The vessels diameters were smaller in the females than in the males, except for the diameter of the posterior communicating artery. Cadavers' examination revealed six cases with complete circle, 3 cases of unilateral fetal posterior communicating and one case of absent posterior communicating artery. Conclusion: The present study showed the amazing great variability of the anatomy of

  12. Environmental, depositional and cultural changes in the upper Pleistocene and early Holocene; the Cinglera del Capello Sequence (Capellades, Spain)

    Science.gov (United States)

    Vaquero, Manuel; Allue, Ethel; Bischoff, James L.; Burjachs, Francesc; Vallverdu, Josep

    2013-01-01

    The correlation between environmental and cultural changes is one of the primary archeological and paleoanthropological research topics. Analysis of ice and marine cores has yielded a high-resolution record of millennial-scale changes during the Late Pleistocene and Holocene eras. However, cultural changes are documented in low-resolution continental deposits; thus, their correlation with the millennial-scale climatic sequence is often difficult. In this paper, we present a rare occurrence in which a thick archeological sequence is associated with a high-resolution environmental record. The Cinglera del Capello is a tufa-draped cliff located in the northeastern Iberian Peninsula, 50 km west of Barcelona. This cliff harbors several rock-shelters with Late Pleistocene and Early Holocene deposits. Together, the deposits of four rock-shelters span from 7000 to 70,000 years ago and provide a high-resolution record of the environmental and human dynamics during this timespan. This record allows the correlation of the cultural and environmental changes. The multiproxy approach to the Cinglera evidence indicates that the main cultural stages of the Late Pleistocene and Early Holocene (Middle Paleolithic, Upper Paleolithic and Mesolithic) are associated with significant changes in the environmental and depositional contexts.

  13. METALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20110165 Chen Jiawei(The 3rd Geological Team,Henan Bureau of Geology and Mineral Resources,Xinyang 464000,China)Ore Control Conditions and Genetic Model for the Bodaoling Ag-Au Deposit in Guangshan,Henan Province(Acta Geologica Sichuan,ISSN1006-0995,CN51-1273/P,30(1),2010,p.28-30,5 illus.,1 ref.,with English abstract)Key words:gold ores,Henan Province20110166 Chen Mingquan(Geological Team 306,Yunnan Bureau of Nonferrous Geology,Kunming 650216,Ch

  14. METALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>20122389 Cai Lianyou ( No.332 Geological Team,Bureau of Geology and Mineral Resources Exploration of Anhui Province,Huangshan 245000,China );Weng Wangfei Geologic Characteristic and Ore-Control Factors of the Nanshan W-Mo Polymetallic Ore Deposit in South Anhui Province ( Geological Survey and Research,ISSN1672-4135,CN12-1353 / P,34 ( 4 ), 2011,p.290-298,3 illus.,1table,14refs. ) Key words:tungsten ores,molybdenum ores,ore guide of prospecting,Anhui Province

  15. CIRCLE OF WILLIS: VARIANT FORMS AND THEIR EMBRYOLOGY USING GROSS DISSECTION AND MAGNETIC RESONANCE ANGIOGRAPHY

    Directory of Open Access Journals (Sweden)

    Bishwajeet Saikia

    2014-06-01

    Full Text Available Background: The circle of Willis is a large arterial anastomotic ring present at the base of the brain uniting the internal carotid and the vertebrobasilar systems. Branches from the internal carotid and vertebral arteries anastomose to form an arterial circle in the basal cisterns and then distribute to supply the brain. The anatomy of the circle is known to vary significantly; the vessels may be absent or sufficiently narrowed altering the hemodynamics of the circle of Willis and affecting its role as a collateral route. These variant forms can be correlated to their phylogeny and embryology. Prior knowledge of these variant forms is important in pathologies and treatment (e.g. parent artery occlusion for carotid aneurysms resulting occlusion of carotid and vertebral arteries. Context and purpose: Our study was undertaken to observe and compare the morphology of circle of Willis using two entirely different methods; gross dissection (GD and Magnetic resonance angiography (MRA and to correlate the variant patterns encountered with the possible underlying developmental events. Gross dissection was carried out in 70 human cadavers and equal numbers of MRA’s of healthy individuals were studied retrospectively. Results: Only 31 cases (22.14% presented with a complete circle of Willis, out of which 14 (20% were cadaveric specimen and 17 (24.18% were in MRA group. Unilateral hypoplastic posterior communicating artery was the most common variation observed in our study (19.28%. Conclusions: The wide variation in completeness of the circle of Willis in general population is similar to earlier observations. Review of phylogeny and embryology makes us familiar with variant forms which would be otherwise difficult to recognize and may be misinterpreted. MRA and gross dissection findings despite certain variations are comparable.

  16. Limestone cliff - face and cave use by wild ring-tailed lemurs (Lemur catta in southwestern Madagascar

    Directory of Open Access Journals (Sweden)

    Michelle L. Sauther

    2013-11-01

    Full Text Available Ring-tailed lemurs live in a range of habitats in southwestern Madagascar. To date, much of the knowledge of ring-tailed lemur ecology, biology and behavior come from riverine gallery forests sites. Recent years have seen an expansion of comprehensive research on this resilient species, including areas of limestone spiny forest along Madagascar’s southwestern coast. This work is documenting newly discovered behaviors by this species. The regular use of cliff-faces and embedded crevices and caves by ring-tailed lemurs in southwestern Madagascar are reported here. Cave use by several anthropoid primates has been explained as a thermoregulatory behavior. It is suggested that cliff-face and cave use by these ring-tailed lemurs serves several purposes, including resource acquisition, thermoregulation, and as an anti-predator avoidance strategy in the absence of suitable large sleeping trees. Observations indicate that the limestone boundaries of the Mahafaly Plateau and their associated xerophytic scrub forests warrant further conserva­tion attention, given the presence of behavioral variation and increasing threats to this endangered primate species. RÉSUMÉLemur catta occupe divers habitats dans le Sud-ouest de Madagascar. L’écologie, la biologie et le comportement de Lemur catta sont actuellement mieux connus des populations vivant dans les forêts riveraines et les zones environnantes. Pour mieux comprendre cette espèce de lémurien, les recherches ont été étendues à d’autres habitats dont les forêts épineuses du plateau calcaire qui est situé le long du littoral Sud-ouest de Madagascar. Dans cette étude nous rapportons les comportements récemment découverts de Lemur catta qui utilise les falaises et les grottes dans le Sud-ouest de Madagascar. L’utilisation des grottes par la plupart des primates hominoïdes est liée à un avantage thermorégulateur offert par ce milieu. Dans notre cas, l’exploitation de falaises et de

  17. Hydrogeology of the Cliff House Sandstone in the San Juan structural basin, New Mexico, Colorado, Arizona and Utah

    Science.gov (United States)

    Thorn, Conde R.; Levings, G.W.; Craigg, S.D.; Dam, W.L.; Kernodle, J.M.

    1990-01-01

    This report is one in a series resulting from the U.S. Geological Survey's Regional Aquifer-System Analysis (RASA) study of the San Juan structural basin that began in October 1984. Previous reports in the series describe the hydrogeology of the Dakota Sandstone (Craigg and others, 1989), Point Lookout Sandstone (Craigg and others, 1990), Morrison Formation (Dam and others, 1990), Gallup Sandstone (Kernodle and others, 1989), and Menefee Formation (Levings and others, 1990) in the San Juan structural basin. The purposes of the RASA (Welder, 1986) are to: (1) Define and evaluate the aquifer system; (2) assess the effects of past, present, and potential ground-water use on aquifers and streams; and (3) determine the availability and quality of ground water. This report summarizes information on the geology and the occurrence and quality of water in the Cliff House Sandstone, one of the primary water-bearing units in the regional aquifer system. Data used in this report were collected during the study or were derived from existing records in the U.S. Geological Survey's computerized National Water Information System (NWIS) data base, the Petroleum Information Corporation's data base, and the Dwight's ENERGYDATA Inc. BRIN data base. Although all data available for the Cliff House Sandstone were considered in formulating the discussions in the text, not all those data could be plotted on the illustrations. The San Juan structural basin is in New Mexico, Colorado, Arizona, and Utah and has an area of about 21,600 square miles (fig. 1). The structural basin is about 140 miles wide and about 200 miles long. The study area is that part of the structural basin that contains rocks of Triassic or younger age and, therefore, is less extensive than the structural basin. Triassic through Tertiary sedimentary rocks are emphasized in this study because the major aquifers in the basin are present in these rocks. The study area is about 140 miles wide (about the same as the

  18. Electrophoretic deposition of nickel zinc ferrite nanoparticles into microstructured patterns

    Directory of Open Access Journals (Sweden)

    Stefan J. Kelly

    2016-05-01

    Full Text Available Using DC electric fields, nickel-zinc ferrite (Ni0.5Zn0.5Fe2O4 nanoparticles (Dh =16.6 ± 3.6 nm are electrophoretically deposited onto silicon substrates to form dense structures defined by photoresist molds. Parameters such as electric field, bath composition, and deposition time are tuned to produce films ranging in thickness from 177 to 805 nm. The deposited films exhibit soft magnetic properties with a saturation magnetization of 60 emu/g and a coercivity of 2.6 kA/m (33 Oe. Additionally, the influence of the photoresist mold on the deposit profile is studied, and patterned films with different shapes (lines, squares, circles, etc. are demonstrated with feature sizes down to 5 μm.

  19. Accurate episomal HIV 2-LTR circles quantification using optimized DNA isolation and droplet digital PCR

    Directory of Open Access Journals (Sweden)

    Eva Malatinkova

    2014-11-01

    Full Text Available Introduction: In HIV-infected patients on combination antiretroviral therapy (cART, the detection of episomal HIV 2-LTR circles is a potential marker for ongoing viral replication. Quantification of 2-LTR circles is based on quantitative PCR or more recently on digital PCR assessment, but is hampered due to its low abundance. Sample pre-PCR processing is a critical step for 2-LTR circles quantification, which has not yet been sufficiently evaluated in patient derived samples. Materials and Methods: We compared two sample processing procedures to more accurately quantify 2-LTR circles using droplet digital PCR (ddPCR. Episomal HIV 2-LTR circles were either isolated by genomic DNA isolation or by a modified plasmid DNA isolation, to separate the small episomal circular DNA from chromosomal DNA. This was performed in a dilution series of HIV-infected cells and HIV-1 infected patient derived samples (n=59. Samples for the plasmid DNA isolation method were spiked with an internal control plasmid. Results: Genomic DNA isolation enables robust 2-LTR circles quantification. However, in the lower ranges of detection, PCR inhibition caused by high genomic DNA load substantially limits the amount of sample input and this impacts sensitivity and accuracy. Moreover, total genomic DNA isolation resulted in a lower recovery of 2-LTR templates per isolate, further reducing its sensitivity. The modified plasmid DNA isolation with a spiked reference for normalization was more accurate in these low ranges compared to genomic DNA isolation. A linear correlation of both methods was observed in the dilution series (R2=0.974 and in the patient derived samples with 2-LTR numbers above 10 copies per million peripheral blood mononuclear cells (PBMCs, (R2=0.671. Furthermore, Bland–Altman analysis revealed an average agreement between the methods within the 27 samples in which 2-LTR circles were detectable with both methods (bias: 0.3875±1.2657 log10. Conclusions: 2-LTR

  20. Automatic Detection and Quantification of WBCs and RBCs Using Iterative Structured Circle Detection Algorithm

    Directory of Open Access Journals (Sweden)

    Yazan M. Alomari

    2014-01-01

    Full Text Available Segmentation and counting of blood cells are considered as an important step that helps to extract features to diagnose some specific diseases like malaria or leukemia. The manual counting of white blood cells (WBCs and red blood cells (RBCs in microscopic images is an extremely tedious, time consuming, and inaccurate process. Automatic analysis will allow hematologist experts to perform faster and more accurately. The proposed method uses an iterative structured circle detection algorithm for the segmentation and counting of WBCs and RBCs. The separation of WBCs from RBCs was achieved by thresholding, and specific preprocessing steps were developed for each cell type. Counting was performed for each image using the proposed method based on modified circle detection, which automatically counted the cells. Several modifications were made to the basic (RCD algorithm to solve the initialization problem, detecting irregular circles (cells, selecting the optimal circle from the candidate circles, determining the number of iterations in a fully dynamic way to enhance algorithm detection, and running time. The validation method used to determine segmentation accuracy was a quantitative analysis that included Precision, Recall, and F-measurement tests. The average accuracy of the proposed method was 95.3% for RBCs and 98.4% for WBCs.

  1. Calculation of the mean circle size does not circumvent the bottleneck of crowding.

    Science.gov (United States)

    Banno, Hayaki; Saiki, Jun

    2012-10-22

    Visually, we can extract a statistical summary of sets of elements efficiently. However, our visual system has a severe limitation in that the ability to recognize an object is remarkably impaired when it is surrounded by other objects. The goal of this study was to investigate whether the crowding effect obstructs the calculation of the mean size of objects. First, we verified that the crowding effect occurs when comparing the sizes of circles (Experiment 1). Next, we manipulated the distances between circles and measured the sensitivity when circles were on or off the limitation of crowding (Experiment 2). Participants were asked to compare the mean sizes of the circles in the left and right visual fields and to judge which was larger. Participants' sensitivity to mean size difference was lower when the circles were located in the nearer distance. Finally, we confirmed that crowding is responsible for the observed results by showing that displays without a crowded object eliminated the effects (Experiment 3). Our results indicate that the statistical information of size does not circumvent the bottleneck of crowding.

  2. Does the Value Circle Exist Within Persons or Only Across Persons?

    Science.gov (United States)

    Borg, Ingwer; Bardi, Anat; Schwartz, Shalom H

    2017-04-01

    This study tests whether the Schwartz (1992) value circle exists within individuals, not only across individuals, thereby providing evidence for the within-person rationale underlying the value circle. We analyze responses from five samples (a representative sample in Britain, a general population sample in the United States, and university students in Britain and Iran) varying in value measures of the Schwartz value theory (SVS, PVQ40, PVQ21). An unfolding model is used to map each person's value profile into a two-dimensional space representing both persons and values. In all samples, clear value circles were found, with values ordered around the circle largely according to the theory. The model also represents most individuals well. The value circle exists within individuals, providing strong support for the underlying within-person rationale for the Schwartz (1992) value theory. The unfolding analysis allows identifying which persons fit the model less well and in which way, identifying how meaningful subgroups differ in their value profiles, and testing whether meaningful subgroups have different value structures. The model opens up many new possibilities for research linking values to other variables.

  3. A simple technique for morphological measurement of cerebral arterial circle variations using public domain software (Osiris).

    Science.gov (United States)

    Ansari, Saeed; Dadmehr, Majid; Eftekhar, Behzad; McConnell, Douglas J; Ganji, Sarah; Azari, Hassan; Kamali-Ardakani, Shahab; Hoh, Brian L; Mocco, J

    2011-12-01

    This article describes a straightforward method to measure the dimensions and identify morphological variations in the cerebral arterial circle using the general-purpose software program Osiris. This user-friendly and portable program displays, manipulates, and analyzes medical digital images, and it has the capability to determine morphometric properties of selected blood vessels (or other anatomical structures) in humans and animals. To ascertain morphometric variations in the cerebral arterial circle, 132 brains of recently deceased fetuses, infants, and adults were dissected. The dissection procedure was first digitized, and then the dimensions were measured with Osiris software. Measurements of each vessel's length and external diameters were used to identify and classify morphological variations in the cerebral arterial circle. The most commonly observed anatomical variations were uni- and bilateral hypoplasia of the posterior communicating artery. This study demonstrates that public domain software can be used to measure and classify cerebral arterial circle vessels. This method could be extended to examine other anatomical regions or to study other animals. Additionally, knowledge of variations within the circle could be applied clinically to enhance diagnostic and treatment specificity.

  4. Observations of debris flows at Chalk Cliffs, Colorado, USA: Part 1, in-situ measurements of flow dynamics, tracer particle movement and video imagery from the summer of 2009

    Science.gov (United States)

    McCoy, Scott W.; Coe, Jeffrey A.; Kean, Jason W.; Tucker, Greg E.; Staley, Dennis M.; Wasklewicz, Thad A.

    2011-01-01

    Debris flows initiated by surface-water runoff during short duration, moderate- to high-intensity rainfall are common in steep, rocky, and sparsely vegetated terrain. Yet large uncertainties remain about the potential for a flow to grow through entrainment of loose debris, which make formulation of accurate mechanical models of debris-flow routing difficult. Using a combination of in situ measurements of debris flow dynamics, video imagery, tracer rocks implanted with passive integrated transponders (PIT) and pre- and post-flow 2-cm resolution digital terrain models (terrain data presented in a companion paper by STALEY et alii, 2011), we investigated the entrainment and transport response of debris flows at Chalk Cliffs, CO, USA. Four monitored events during the summer of 2009 all initiated from surface-water runoff, generally less than an hour after the first measurable rain. Despite reach-scale morphology that remained relatively constant, the four flow events displayed a range of responses, from long-runout flows that entrained significant amounts of channel sediment and dammed the main-stem river, to smaller, short-runout flows that were primarily depositional in the upper basin. Tracer-rock travel-distance distributions for these events were bimodal; particles either remained immobile or they travelled the entire length of the catchment. The long-runout, large-entrainment flow differed from the other smaller flows by the following controlling factors: peak 10-minute rain intensity; duration of significant flow in the channel; and to a lesser extent, peak surge depth and velocity. Our growing database of natural debris-flow events can be used to develop linkages between observed debris-flow transport and entrainment responses and the controlling rainstorm characteristics and flow properties.

  5. Physiological and lifestyle factors contributing to risk and severity of peri-orbital dark circles in the Brazilian population*

    Science.gov (United States)

    Matsui, Mary S; Schalka, Sérgio; Vanderover, Garrett; Fthenakis, Christina G.; Christopher, J; Bombarda, Patricia Camarano Pinto; Bueno, Juliana Regina; Viscomi, Bianca Lenci Inácio; Bombarda Júnior, Mário Sérgio

    2015-01-01

    BACKGROUND Peri-orbital dark circles are a cosmetic concern worldwide, and have been attributed to hyperpigmentation from allergy or atopic dermatitis, blood stasis, structural shadowing effects, and a thin epidermis/dermis under the eye. It is of interest to better understand lifestyle and demographic risk factors and the relative impact of melanin, blood and epidermal/dermal factors on the severity of Peri-orbital dark circles. OBJECTIVE To compare by non-invasive imaging the impact of biological factors to a visual grading scale for Peri-orbital dark circles, and test the correlation of various demographic factors with Peri-orbital dark circles. METHODS Subjects completed a lifestyle and health survey, and Peri-orbital dark circles severity was evaluated using standardized photographs. Hyperspectral image analysis was used to assess the contributions of melanin, blood volume, degree of blood oxygen saturation, and dermal scattering. RESULTS Family history was the most significant risk factor for Peri-orbital dark circles. The average age of onset was 24 years, and earlier onset correlated with higher severity scores. Asthma was significantly associated with Peri-orbital dark circles scores, but self-reported allergy was not. In this study, sleep was not correlated with Peri-orbital dark circles scores. Hyperspectral imaging indicated that melanin was the dominant correlate for Peri-orbital dark circles severity, while oxygen saturation was secondary. The difference between under-eye and cheek measurements for ∆L*and ∆E* were the most significant instrumental parameters correlated with visual assessment of Peri-orbital dark circles severity. CONCLUSION Although typically associated with lack of sleep, risk of Peri-orbital dark circles is primarily hereditary. The main factors contributing to the appearance of Peri-orbital dark circles are melanin and (deoxygenated) blood. PMID:26375218

  6. NONMETALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20111761 Chen Hua(115 Geological Party,Guizhou Bureau of Geology and Mineral Exploration & Development,Guiyang 551400,China);Deng Chao Analysis on the Metallogenic Environment of Maochang Bauxite in Guizhou Province(Guizhou Geology,ISSN1000-5943,CN52-1059/P,27(3),2010,p.198-201,2 illus.,1 table,8 refs.)Key words:bauxite deposit,Guizhou Province By long time physical and chemical process,the carbonate rock after Central Guizhou uplidft,becomes red clay,after further weathering,the red clay decomposed into the oxide,hydroxide of Al and Fe,in the dissolution hole and depression,it concentrates primary fragmentary tight and earthy karst bauxite ore.Because the variation of landform,it decomposes and cracks again,affords the material source

  7. The distinction of submarine mass failure deposits from tsunami backwash deposits - an example from Hornitos, Northern Chile

    Science.gov (United States)

    Spiske, M.; Bahlburg, H.; Weiss, R.

    2013-12-01

    Sedimentary features of onshore tsunami deposits were studied in great detail within the last decade. While the characteristics of such onshore deposits are well documented, the associated marine tsunami effects, such as sediment dispersion, re-deposition, and sediment bypassing during runup and backwash are scarcely reported. The knowledge of the appearance of submarine tsunami features is important, not only to understand the hydrodynamic processes involved, but also because pre-Quaternary sediments tend to be of marine origin when extending the geological record farther into the past. In this study we challenge the former interpretation of a backwash tsunami origin of a Pliocene coarse clast unit at Hornitos that was previously linked to the Eltanin impact tsunami. The respective unit contains several tens of meters long rock slabs and components from both the shallow marine basin and onshore environments, such as alluvial fans, beaches, cliffs and the local basement rocks. It is intercalated into breccia layers of smaller scale that represent the likewise energetic background sedimentation. The unit was most likely emplaced by a high-density flow with possible hydroplaning at its base and front. This is underlined by soft-sediment deformation and sand dykes. The comparison to recent submarine tsunami sediments shows that there are hardly any similarities, most notably because the unit at Hornitos was deposited en masse without any obvious trends. Our re-interpretation considers the local synsedimentary tectonic background and a comparison to recent submarine tsunami sediments caused by tsunamis with similar onshore wave heights. We show that a relation to the Eltanin impact can be excluded because enhanced models that include a shoaling effect as soon as the tsunami approaches shallow shelf regions prove that such an impact did not entail large onshore wave heights at Hornitos. Additionally, the biostratigraphic age of the La Portada formation is not

  8. Cosmogenic Exposure Dating of Paleo-Rockfall Deposits, Christchurch, New Zealand

    Science.gov (United States)

    Mackey, B. H.; Quigley, M.

    2013-12-01

    The 22nd February 2011 MW 6.2 Christchurch earthquake occurred on a previously unrecognized blind thrust fault and generated severe localized vertical ground accelerations (>2 g). Constraining rupture history for such faults is challenging as there is no surface evidence of faulting (e.g., scarps, fault traces) which can be studied directly. However, the earthquake generated a range of secondary effects, including extensive rockfall and cliff collapse at many locations around the Port Hills south of Christchurch, remnants of a Miocene strato-shield volcanic complex. Many of these sites also exhibit pre-historic rockfall deposits. Here we ask whether ancient rockfall deposits can serve as off-fault evidence for paleo-earthquakes, and can be used to constrain the timing of previous episodes of severe shaking? Our site at Rapaki Bay west of Lyttelton is ideally suited for analysis of paleo-rockfall events as it has a prominent 60 m high sub-vertical cliff comprised of stratified lava flows, and a 600-m-long planar fore-slope. The site experienced significant, well-documented rockfall during the 2011 event, and has large (2-10 m diameter), lichen-covered boulders scattered down slope and partially embedded in late Quaternary loess and colluvium. We employ cosmogenic exposure dating of paleo-rockfall boulders to establish the timing of boulder emplacement. The basalt rock contains abundant clinopyroxene (augite) which is able to quantitatively retain cosmogenic 3He. This approach requires constraining the inherited 3He from non-cosmogenic sources, the potential cosmogenic exposure while boulders are on the cliff, and the background erosion rate. The probability distribution of exposure ages from the surface of pre-historically emplaced boulders show significant clustering of ages in the mid Holocene, with a long tail of individual ages out to ~60 ka. Comparison with numerical modeling of a range of rockfall event scenarios reveals the measured age distribution is most

  9. Great circle solution to polarization-based quantum communication (QC) in optical fiber

    Science.gov (United States)

    Nordholt, Jane Elizabeth; Peterson, Charles Glen; Newell, Raymond Thorson; Hughes, Richard John

    2016-03-15

    Birefringence in optical fibers is compensated by applying polarization modulation at a receiver. Polarization modulation is applied so that a transmitted optical signal has states of polarization (SOPs) that are equally spaced on the Poincare sphere. Fiber birefringence encountered in propagation between a transmitter and a receiver rotates the great circle on the Poincare sphere that represents the polarization bases used for modulation. By adjusting received polarizations, polarization components of the received optical signal can be directed to corresponding detectors for decoding, regardless of the magnitude and orientation of the fiber birefringence. A transmitter can be configured to transmit in conjugate polarization bases whose SOPs can be represented as equidistant points on a great circle so that the received SOPs are mapped to equidistant points on a great circle and routed to corresponding detectors.

  10. Orthogonal Laurent polynomials in unit circle, extended CMV ordering and 2D Toda type integrable hierarchies

    CERN Document Server

    Alvarez-Fernandez, Carlos

    2012-01-01

    Orthogonal Laurent polynomials in the unit circle and the theory of Toda-like integrable systems are connected using the Gauss--Borel factorization of a Cantero-Moral-Velazquez moment matrix, which is constructed in terms of a complex quasi-definite measure supported in the unit circle. The factorization of the moment matrix leads to orthogonal Laurent polynomials in the unit circle and the corresponding second kind functions. Jacobi operators, 5-term recursion relations and Christoffel-Darboux kernels, projecting to particular spaces of truncated Laurent polynomials, and corresponding Christoffel-Darboux formulae are obtained within this point of view in a completely algebraic way. Cantero-Moral-Velazquez sequence of Laurent monomials is generalized and recursion relations, Christoffel-Darboux kernels, projecting to general spaces of truncated Laurent polynomials and corresponding Christoffel-Darboux formulae are found in this extended context. Continuous deformations of the moment matrix are introduced and ...

  11. Mosh pits and Circle pits: Collective motion at heavy metal concerts

    Science.gov (United States)

    Bierbaum, Matthew; Silverberg, Jesse L.; Sethna, James P.; Cohen, Itai

    2013-03-01

    Heavy metal concerts present an extreme environment in which large crowds (~102 -105) of humans experience very loud music (~ 130 dB) in sync with bright, flashing lights, often while intoxicated. In this setting, we find two types of collective motion: mosh pits, in which participants collide with each other randomly in a manner resembling an ideal gas, and circle pits, in which participants run collectively in a circle forming a vortex of people. We model these two collective behaviors using a flocking model and find qualitative and quantitative agreement with the behaviors found in videos of metal concerts. Futhermore, we find a phase diagram showing the transition from a mosh pit to a circle pit as well as a predicted third phase, lane formation.

  12. PACKING CIRCLES WITHIN CIRCULAR CONTAINERS: A NEW HEURISTIC ALGORITHM FOR THE BALANCE CONSTRAINTS CASE

    Directory of Open Access Journals (Sweden)

    Washington Alves de Oliveira

    Full Text Available ABSTRACT In this work we propose a heuristic algorithm for the layout optimization for disks installed in a rotating circular container. This is a unequal circle packing problem with additional balance constraints. It proved to be an NP-hard problem, which justifies heuristics methods for its resolution in larger instances. The main feature of our heuristic is based on the selection of the next circle to be placed inside the container according to the position of the system's center of mass. Our approach has been tested on a series of instances up to 55 circles and compared with the literature. Computational results show good performance in terms of solution quality and computational time for the proposed algorithm.

  13. On the sum of powered distances to certain sets of points on the circle

    CERN Document Server

    Nikolov, Nikolai

    2011-01-01

    In this paper we consider an extremal problem in geometry. Let $\\lambda$ be a real number and $A$, $B$ and $C$ be arbitrary points on the unit circle $\\Gamma$. We give full characterization of the extremal behavior of the function $f(M,\\lambda)=MA^\\lambda+MB^\\lambda+MC^\\lambda$, where $M$ is a point on the unit circle as well. We also investigate the extremal behavior of $\\sum_{i=1}^nXP_i$, where $P_i, i=1,...,n$ are the vertices of a regular $n$-gon and $X$ is a point on $\\Gamma$, concentric to the circle circumscribed around $P_1...P_n$. We use elementary analytic and purely geometric methods in the proof.

  14. An Algorithmic Solution for Computing Circle Intersection Areas and its Applications to Wireless Communications

    CERN Document Server

    Librino, Federico; Zorzi, Michele

    2012-01-01

    A novel iterative algorithm for the efficient computation of the intersection areas of an arbitrary number of circles is presented. The algorithm, based on a trellis-structure, hinges on two geometric results which allow the existence-check and the computation of the area of the intersection regions generated by more than three circles by simple algebraic manipulations of the intersection areas of a smaller number of circles. The presented algorithm is a powerful tool for the performance analysis of wireless networks, and finds many applications, ranging from sensor to cellular networks. As an example of practical application, an insightful study of the uplink outage probability of in a wireless network with cooperative access points as a function of the transmission power and access point density is presented.

  15. An algorithm for Path planning with polygon obstacles avoidance based on the virtual circle tangents

    Directory of Open Access Journals (Sweden)

    Zahraa Y. Ibrahim

    2016-12-01

    Full Text Available In this paper, a new algorithm called the virtual circle tangents is introduced for mobile robot navigation in an environment with polygonal shape obstacles. The algorithm relies on representing the polygonal shape obstacles by virtual circles, and then all the possible trajectories from source to target is constructed by computing the visible tangents between the robot and the virtual circle obstacles. A new method for searching the shortest path from source to target is suggested. Two states of the simulation are suggested, the first one is the off-line state and the other is the on-line state. The introduced method is compared with two other algorithms to study its performance.

  16. "Socratic Circles are a Luxury": Exploring the Conceptualization of a Dialogic Tool in Three Science Classrooms

    Science.gov (United States)

    Copelin, Michelle Renee

    Research has shown that dialogic instruction promotes learning in students. Secondary science has traditionally been taught from an authoritative stance, reinforced in recent years by testing policies requiring coverage. Socratic Circles are a framework for student-led dialogic discourse, which have been successfully used in English language arts and social studies classrooms. The purpose of this research was to explore the implementation process of Socratic Circles in secondary science classes where they have been perceived to be more difficult. Focusing on two physical science classes and one chemistry class, this study described the nature and characteristics of Socratic Circles, teachers' dispositions toward dialogic instruction, the nature and characteristics of student discussion, and student motivation. Socratic Circles were found to be a dialogic support that influenced classroom climate, social skills, content connections, and student participation. Teachers experienced conflict between using traditional test driven scripted teaching, and exploring innovation through dialogic instruction. Students experienced opportunities for peer interaction, participation, and deeper discussions in a framework designed to improve dialogic skills. Students in two of the classrooms showed evidence of motivation for engaging in peer-led discussion, and students in one class did not. The class that did not show evidence of motivation had not been given the same scaffolding as the other two classes. Two physical science teachers and one chemistry teacher found that Socratic Circles required more scaffolding than was indicated by their peers in other disciplines such as English and social studies. The teachers felt that student's general lack of background knowledge for any given topic in physical science or chemistry necessitated the building of a knowledge platform before work on a discussion could begin. All three of the teachers indicated that Socratic Circles were a

  17. Zernike expansion of derivatives and Laplacians of the Zernike circle polynomials.

    Science.gov (United States)

    Janssen, A J E M

    2014-07-01

    The partial derivatives and Laplacians of the Zernike circle polynomials occur in various places in the literature on computational optics. In a number of cases, the expansion of these derivatives and Laplacians in the circle polynomials are required. For the first-order partial derivatives, analytic results are scattered in the literature. Results start as early as 1942 in Nijboer's thesis and continue until present day, with some emphasis on recursive computation schemes. A brief historic account of these results is given in the present paper. By choosing the unnormalized version of the circle polynomials, with exponential rather than trigonometric azimuthal dependence, and by a proper combination of the two partial derivatives, a concise form of the expressions emerges. This form is appropriate for the formulation and solution of a model wavefront sensing problem of reconstructing a wavefront on the level of its expansion coefficients from (measurements of the expansion coefficients of) the partial derivatives. It turns out that the least-squares estimation problem arising here decouples per azimuthal order m, and per m the generalized inverse solution assumes a concise analytic form so that singular value decompositions are avoided. The preferred version of the circle polynomials, with proper combination of the partial derivatives, also leads to a concise analytic result for the Zernike expansion of the Laplacian of the circle polynomials. From these expansions, the properties of the Laplacian as a mapping from the space of circle polynomials of maximal degree N, as required in the study of the Neumann problem associated with the transport-of-intensity equation, can be read off within a single glance. Furthermore, the inverse of the Laplacian on this space is shown to have a concise analytic form.

  18. Stream of Consciousness and Symbolism, the“Magic”Used by Heming-way to Characterize Harry as A Dying Man on the Cliff of Kilimanjaro

    Institute of Scientific and Technical Information of China (English)

    蓝清珂

    2016-01-01

    The Snows of Kilimanjaro was written in the 20th century when the realism was still the main stream in the field of litera-ture. However, Hemingway broke the cocoon of realism and flew into a new literary kingdom—modernism, where many new theories such as stream of consciousness and archetypal symbol blossomed and were used in literature. This paper mainly ana-lyzed how stream of consciousness and symbolism were used in the Snows of Kilimanjaro to characterize Harry as a dying man on the cliff of Kilimanjaro.

  19. Dendrobium officinale cliff epiphytic cultivation method%铁皮石斛悬崖附生栽培技术研究

    Institute of Scientific and Technical Information of China (English)

    斯金平; 陈梓云; 刘京晶; 朱玉球; 蔡国见; 黄柄荣; 章焜一; 金传高

    2015-01-01

    以铁皮石斛设施栽培投入大、药材功效不如野生等问题为导向,通过水分调控、崖壁坡度选择,研究悬崖附生铁皮石斛生长情况、农艺性状、产量、多糖及醇溶性浸出物含量.结果表明,将铁皮石斛附生于85 ~ 90°悬崖表面,在生长季节喷水1 ~2 h·d-1的条件下,即使在裸露的环境中,不用基质,不施肥料也能够较好的生长,获得较高的产量,其形态与悬崖上野生铁皮石斛无异;多糖与醇溶性浸出物含量显著高于设施基质栽培,并与萌蘖生理年龄密切相关,逆境有利于铁皮石斛多糖与醇溶性浸出物等功效成分的积累.%To solve the issues of costly planting of facility cultivation method and inferior efficacy than wild herbs of Dendrobium officinale,the cliff epiphytic cultivation method was studied.To research the growth,agronomic traits,yield,polysaccharide and alcohol-soluble extract contents were measured on the D.officinale from different water regulation and cliff slope gradients treatments.The results showed that D.officinale epiphytic at 85°-90° cliff and sprayed water 1-2 h · d-1 at the growing season can get better growth and obtain high yield,and the morphology has no different from wild cliff D.officinale,even in the environments without shade.The contents of polysaccharide and alcohol-soluble extract are closely related to the physiological ages,but significantly higher than the facility cultivation.It is possible that environmental stresses benefit the accumulation of polysaccharides,alcohol-soluble extract and other efficient ingredients.

  20. Circle of Willis variation in a complex stroke presentation: a case report

    Directory of Open Access Journals (Sweden)

    Young Carolyn A

    2006-03-01

    Full Text Available Abstract Background The impact of circle of Willis anatomical variation upon the presentation of stroke is probably underrecognised. Case presentation A 63-year-old right-handed woman developed a left hemiparesis and right leg weakness sequentially following a road traffic accident (RTA. Despite initial concern about the possibility of cervical spinal cord injury, the final diagnosis was bilateral artery-to-artery embolic cerebral infarction with dominant right internal carotid artery. Conclusion The case illustrates the complex presentation of stroke as a pseudo-cervical cord lesion and the impact of circle of Willis anatomical variation upon the expression of large vessel cerebrovascular disease.

  1. Circular and linear regression fitting circles and lines by least squares

    CERN Document Server

    Chernov, Nikolai

    2010-01-01

    Find the right algorithm for your image processing applicationExploring the recent achievements that have occurred since the mid-1990s, Circular and Linear Regression: Fitting Circles and Lines by Least Squares explains how to use modern algorithms to fit geometric contours (circles and circular arcs) to observed data in image processing and computer vision. The author covers all facets-geometric, statistical, and computational-of the methods. He looks at how the numerical algorithms relate to one another through underlying ideas, compares the strengths and weaknesses of each algorithm, and il

  2. Empirical Research on the Urban Development Level of Wuhan Urban Circle

    Directory of Open Access Journals (Sweden)

    Yazhou Xiong

    2013-03-01

    Full Text Available The research object of this paper is the nine cities of Wuhan urban circle. Firstly, this paper establishes the comprehensive evaluation indicator system and evaluation model of the urban development level via systems analysis, then makes a PCA (Principal Components Analysis to the original data by means of SPSS; Next, this paper analyzes the worked data via AHP (Analytic Hierarchy Process and comprehensive score and ranking of the nine cities is obtained and the nine cities are divided into three clusters via K-means clustering analysis; Finally, this paper appraises urban development level of Wuhan urban circle.

  3. The Voronoi diagram of circles and its application to the visualization of the growth of particles

    DEFF Research Database (Denmark)

    Anton, François; Mioc, Darka; Gold, Christopher M.

    2009-01-01

    Circles are frequently used for modelling the growth of particle aggregates through the Voronoi diagram of circles, that is a special instance of the Johnson-Mehl tessellation. The Voronoi diagram of a set of sites is a decomposition of space into proximal regions. The proximal region of a site...... is the locus of points closer to that site than to any other one. Voronoi diagrams allow one to answer proximity queries after locating a query point in the Voronoi zone it belongs to. The dual graph of the Voronoi diagram is called the Delaunay graph. In this paper, we first show a necessary and sufficient...

  4. Investigation of Brain Arterial Circle Malformations Using Electrical Modelling and Simulation

    Directory of Open Access Journals (Sweden)

    Klara Capova

    2006-01-01

    Full Text Available The paper deals with the cerebral arterial system investigation by means of electrical modelling and simulations. The main attention is paid to the brain arterial circle malformations (stenoses and aneurysms and their determination and evaluation by computer-aided methods as tools of a non-invasive diagnostics. The compensation possibilities of brain arterial circle in case of presence of concrete arterial malformations are modelled and simulated. The simulation results of brain arteries blood pressures and volume flow velocities time dependences are presented and discussed under various health conditions.

  5. Amplitude variables of circle on the pedagogic pommel horse in gymnastics.

    Science.gov (United States)

    Baudry, Ludovic; Sforza, Chiarella; Leroy, David; Lovecchio, Nicola; Gautier, Geoffroy; Thouvarecq, Régis

    2009-05-01

    The movement amplitude is a key component of numerous elements in gymnastics. The purpose of the present study is to highlight the most pertinent amplitude variable of the circle performed on the pedagogic pommel horse. Twelve gymnasts (6 expert gymnasts vs. 6 nonexpert gymnasts) performed 10 circles on this event. A Vicon 512 system was used to record the 3-dimensional position of 11 markers fixed on the gymnasts. Our results revealed than 4 amplitude variables permitted us to significantly discriminate the levels of performance of the gymnasts (p gymnasts and to measure improvement in movements after specific training.

  6. Vicious circles of punishment: a reading of Melanie Klein's Envy and gratitude.

    Science.gov (United States)

    Smith, Henry F

    2008-01-01

    Staged as a moral drama, Melanie Klein's Envy and Gratitude (1957) straddles two eras: one reflecting a simpler more concrete, historical method, and the other an approach of greater complexity, focused on the transferential moment. Embedded within the transference are the vicious circles of envy and punishment that are the hallmark of Klein's text. Punishment itself which is always punishment of both self and other, creates its own vicious circle, set in motion by a single act. In the sadomasochistic enactments that result, the moral force of Klein's categories fuels the countertransference. A detailed clinical hour is presented.

  7. Peer Evaluation of Master Programs: Closing the Quality Circle of the CDIO Approach?

    DEFF Research Database (Denmark)

    Hussmann, Peter Munkebo; Bisi, Anita; Malmqvist, Johan;

    2012-01-01

    programs within their field at another N5T institution. The article describes the quality enhancement tool in detail, its contribution to the development of the involved programs, and how international peer evaluation can contribute to closing the quality circle. Finally, it assesses the value...... peer evaluations of educational programs to enable their further development and close the quality circle. In addition, the project will contribute to the consolidation of the N5T alliance by facilitating contacts between faculty members and providing them with an in-depth knowledge of the study...

  8. From Death to Life – The Hydrological Circle of Cosmos and Copulation

    Directory of Open Access Journals (Sweden)

    Terje Oestigaard

    2008-10-01

    Full Text Available When a person dies, how is the soul transferred from the dead body to an infant in a mother's womb? In Hinduism this process in understood and explained metaphorically by the hydrological circle and the interrelatedness of fire and water. The cosmological circle of reincarnation is a life-giving process which includes the life-giving waters; the essence of life. Based on mythology and the sacred scriptures, this process is investigated.Key Words: Hindu Mythology, eroticism, funeral practice, sexualityDOI = 10.3126/dsaj.v2i0.1360Dhaulagiri Journal of Sociology and Anthropology Vol.2 pp.121-144

  9. Migraine with aura is associated with an incomplete circle of willis: results of a prospective observational study.

    Directory of Open Access Journals (Sweden)

    Brett Cucchiara

    Full Text Available OBJECTIVE: To compare the prevalence of an incomplete circle of Willis in patients with migraine with aura, migraine without aura, and control subjects, and correlate circle of Willis variations with alterations in cerebral perfusion. METHODS: Migraine with aura, migraine without aura, and control subjects were prospectively enrolled in a 1∶1∶1 ratio. Magnetic resonance angiography was performed to examine circle of Willis anatomy and arterial spin labeled perfusion magnetic resonance imaging to measure cerebral blood flow. A standardized template rating system was used to categorize circle of Willis variants. The primary pre-specified outcome measure was the frequency of an incomplete circle of Willis. The association between circle of Willis variations and cerebral blood flow was also analyzed. RESULTS: 170 subjects were enrolled (56 migraine with aura, 61 migraine without aura, 53 controls. An incomplete circle of Willis was significantly more common in the migraine with aura compared to control group (73% vs. 51%, p = 0.02, with a similar trend for the migraine without aura group (67% vs. 51%, p = 0.08. Using a quantitative score of the burden of circle of Willis variants, migraine with aura subjects had a higher burden of variants than controls (p = 0.02. Compared to those with a complete circle, subjects with an incomplete circle had greater asymmetry in hemispheric cerebral blood flow (p = 0.05. Specific posterior cerebral artery variants were associated with greater asymmetries of blood flow in the posterior cerebral artery territory. CONCLUSIONS: An incomplete circle of Willis is more common in migraine with aura subjects than controls, and is associated with alterations in cerebral blood flow.

  10. ULYSSES comes full circle, before revisiting the Sun's poles

    Science.gov (United States)

    1998-04-01

    From its unique perspective, Ulysses has provided scientists with the very first all-round map of the heliosphere, the huge bubble in space filled by the Sun's wind. The Earth swims deep inside the heliosphere, and gusts and shocks in the solar wind can harm satellites, power supplies and ommunications. They may also affect our planet's weather. A better grasp of the solar weather in the heliosphere is therefore one of the major aims of ESA's science programme. In a project of international cooperation between ESA and NASA, Ulysses was launched towards Jupiter in October 1990 by the US space shuttle Discovery. Arriving in February 1992, Ulysses stole energy from the giant planet in a slingshot manoeuvre and was propelled back towards the Sun in an elongated orbit almost at right angles to the ecliptic plane, where the Earth and other planets circle the Sun. "This month Ulysses returns to the point in space where its out-of-ecliptic journey began, but Jupiter isn't there," explains Richard Marsden, ESA's project scientist for Ulysses. "Following its own inexorable path around the Sun, Jupiter is far away on the opposite side of the Solar System. So Ulysses' course will not be changed a second time. The spacecraft is now in effect a man-made comet, forever bound into a 6-year polar orbit around the Sun." Ulysses now starts its second orbit. It will travel over the poles of the Sun in 2000-2001 just as the count of dark sunspots is expected to reach a maximum. With its operational life extended for the Ulysses Solar Maximum Mission, the spacecraft will find the heliosphere much stormier than during its first orbit. Discoveries so far Like its mythical namesake, Ulysses has already had an eventful voyage of discovery. Its unique trajectory has provided the scientific teams with a new perspective, from far out in space and especially in the previously unknown regions of the heliosphere over the Sun's poles. Passing within 9.8 degrees of the polar axis, the highly

  11. Reply to comment on: Lawrence, J.A., Mortimore, R.N., Stone, K.J., and Busby, J.P., 2013. Sea saltwater weakening of chalk and the impact on cliff instability. Geomorphology 191, 14-22

    Science.gov (United States)

    Lawrence, James A.; Mortimore, Rory N.

    2015-02-01

    We are grateful to Dornbusch (2014) for the opportunity to clarify the role we propose for salt water weakening of the chalk and its potential importance as a mechanism contributing to cliff instability. Dornbusch's argument is based largely on a single comment "This work challenges the established view by identifying the role of salt from seawater in the degradation of porous rocks in coastal environments as a third and potentially the most important mechanism leading to chalk cliff collapse" (Lawrence et al., 2013: 15). This was not intended as a "conclusion" as suggested by Dornbusch (2014) but is rather a qualitative introductory statement highlighting the potential importance of the salt water weakening process in coastal cliff instability. The actual conclusions of the work are not challenged by Dornbusch (2014).

  12. Edge of a cliff

    CERN Document Server

    Shimizu, Yusuke

    2016-01-01

    We discuss the neutrino flavor structures in the Occam's razor approach for the Dirac neutrino mass matrices. We assume that the charged lepton mass matrix takes a diagonal base, while the right-handed Majorana neutrino mass matrix is also diagonal and we consider nine patterns of the four zero textures for the Dirac neutrinos mass matrices. We numerically analyze the left-handed Majorana neutrino mass matrices for nine patterns of the Dirac neutrino mass matrices and we found two interesting patterns where both normal and inverted neutrino mass hierarchies can be realized. We also found if the neutrino mass is normal hierarchy, this scenario will be likely to be excluded by the measurements of the Dirac CP violating phase in the T2K and NO$\

  13. The Two-Spectra Inverse Problem for Semi-infinite Jacobi Matrices in The Limit-Circle Case

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Luis O., E-mail: silva@leibniz.iimas.unam.mx; Weder, Ricardo [Instituto de Investigaciones en Matematicas Aplicadas y en Sistemas, Universidad Nacional Autonoma de Mexico, Departamento de Metodos Matematicos y Numericos (Mexico)], E-mail: weder@servidor.unam.mx

    2008-05-15

    We present a technique for reconstructing a semi-infinite Jacobi operator in the limit circle case from the spectra of two different self-adjoint extensions. Moreover, we give necessary and sufficient conditions for two real sequences to be the spectra of two different self-adjoint extensions of a Jacobi operator in the limit circle case.

  14. Making a Circle: Tool Use and the Spaces where We Live

    Science.gov (United States)

    Noble, Tracy; DiMattia, Cara; Nemirovsky, Ricardo; Barros, Apolinario

    2006-01-01

    A group of high school students created a drawing of a circle using a device called the Drawing Machine. To describe their experiences, we propose an alternative to the idea that to master a tool one must create a mental version of the tool. We suggest, instead, that as students change their relationships to a tool over time, their lived-in spaces…

  15. Inquiry into Lemercier de la Rivière’s entry into the circle of Quesnay.

    OpenAIRE

    Bernard Herencia

    2013-01-01

    This paper proposes a new reading of the sources to release a new dating for entering Lemercier de la Rivière in intellectual circles of Quesnay and Mirabeau. In doing so, this Physiocrat generally accepted by commentators as a secondary author of the school led by Quesnay, appears as one of its founders.

  16. Reactivation of chromosomally integrated human herpesvirus-6 by telomeric circle formation.

    Directory of Open Access Journals (Sweden)

    Bhupesh K Prusty

    Full Text Available More than 95% of the human population is infected with human herpesvirus-6 (HHV-6 during early childhood and maintains latent HHV-6 genomes either in an extra-chromosomal form or as a chromosomally integrated HHV-6 (ciHHV-6. In addition, approximately 1% of humans are born with an inheritable form of ciHHV-6 integrated into the telomeres of chromosomes. Immunosuppression and stress conditions can reactivate latent HHV-6 replication, which is associated with clinical complications and even death. We have previously shown that Chlamydia trachomatis infection reactivates ciHHV-6 and induces the formation of extra-chromosomal viral DNA in ciHHV-6 cells. Here, we propose a model and provide experimental evidence for the mechanism of ciHHV-6 reactivation. Infection with Chlamydia induced a transient shortening of telomeric ends, which subsequently led to increased telomeric circle (t-circle formation and incomplete reconstitution of circular viral genomes containing single viral direct repeat (DR. Correspondingly, short t-circles containing parts of the HHV-6 DR were detected in cells from individuals with genetically inherited ciHHV-6. Furthermore, telomere shortening induced in the absence of Chlamydia infection also caused circularization of ciHHV-6, supporting a t-circle based mechanism for ciHHV-6 reactivation.

  17. Integer Programming Formulations for Approximate Packing Circles in a Rectangular Container

    Directory of Open Access Journals (Sweden)

    Igor Litvinchev

    2014-01-01

    Full Text Available A problem of packing a limited number of unequal circles in a fixed size rectangular container is considered. The aim is to maximize the (weighted number of circles placed into the container or minimize the waste. This problem has numerous applications in logistics, including production and packing for the textile, apparel, naval, automobile, aerospace, and food industries. Frequently the problem is formulated as a nonconvex continuous optimization problem which is solved by heuristic techniques combined with local search procedures. New formulations are proposed for approximate solution of packing problem. The container is approximated by a regular grid and the nodes of the grid are considered as potential positions for assigning centers of the circles. The packing problem is then stated as a large scale linear 0-1 optimization problem. The binary variables represent the assignment of centers to the nodes of the grid. Nesting circles inside one another is also considered. The resulting binary problem is then solved by commercial software. Numerical results are presented to demonstrate the efficiency of the proposed approach and compared with known results.

  18. Cultural Safety Circles and Indigenous Peoples' Perspectives: Inclusive Practices for Participation in Higher Education

    Science.gov (United States)

    Aseron, Johnnie; Greymorning, S. Neyooxet; Miller, Adrian; Wilde, Simon

    2013-01-01

    Indigenous experiences, as found within traditional ways and cultural practices, are an acknowledgement of traditional methods for sharing, learning, and collective knowledge development and maintenance. The application of Cultural Safety Circles can help provide a collective space where definitions for cultural and educational exchange can take…

  19. Two-dimensional Few-circle Optical Pulses in the Inhomogeneous Environment of Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    M.B. Belonenko

    2015-12-01

    Full Text Available We consider the task about few-circle optical pulses dynamics (light bullets in the inhomogeneous environment of carbon nanotubes. Electromagnetic field of pulse describes classically, on basis of Maxwell equation, and carbon nanotubes give dispersion law for electrons, which interacting with pulse. We show that light bullets propagate stably.

  20. Effect of end-to-end invagination pancreaticojejunostomy with circle discontinuous U suture in pancreatic surgery

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xuewen; XUAN Wei; JIANG Tao; JI Degang; YANG Yongsheng; ZHANG Dan; XIE Yingjun; MENG Zihui; ZHAO Jisheng

    2007-01-01

    The aim of this paper is to summarize the methods of pancreaficojejunostomy in the pancreatic operation and to study the safety and feasibility of a new operative method called end-to-end invagination pancreaticojejunostomy with circle discontinuous U suture to prevent fistula of pancreaticojejunostomy.Eight-three patients with pancreaticoduodenectomy in the 3rd Hospital,Jilin University from 2001 January to 2006 April were reviewed.The incidences of pancreatic fistula with different types of pancreaticojejunostomy were compared.The overall incidence rate of pancreatic fistula was 26.5% (22/83).No pancreatic fistula occurred in end-to-end invagination pancreaticojejunostomy with circle discontinuous U suture.The incidence rate of the fistula following end-to-end invagination pancreaticojejunostomy with circle discontinuous U suture was significantly lower than that of traditional end-to-end pancreaticojejunostomy [40%,(10/25),P<0.01] and end-to-side pancreaticojejunostomy [27.3%,(12/44),P < 0.05],but no significant difference (P>0.05) between traditional end-to-end pancreaticojejunostomy and end-to-side pancreaticojejunostomywas discovered.End-to-end invagination pancreaticojejunostomy with circle discontinuous U suture has a definite effect on avoiding pancreatic fistula following pancreaticojejunostomy and is worth being recommended.But the cases were limited,so this method would still need to be observed and confirmed further in the future.

  1. The rolling-circle melting-pot model for porcine circovirus DNA replication

    Science.gov (United States)

    A stem-loop structure, formed by a pair of inverted repeats during DNA replication, is a conserved feature at the origin of DNA replication (Ori) among plant and animal viruses, bacteriophages and plasmids that replicate their genomes via the rolling-circle replication (RCR) mechanism. Porcine circo...

  2. Quasi-periodic Bifurcations of Invariant Circles in Low-dimensional Dissipative Dynamical Systems

    NARCIS (Netherlands)

    Vitolo, Renato; Broer, Henk; Simo, Carles

    2011-01-01

    This paper first summarizes the theory of quasi-periodic bifurcations for dissipative dynamical systems. Then it presents algorithms for the computation and continuation of invariant circles and of their bifurcations. Finally several applications are given for quasiperiodic bifurcations of Hopf, sad

  3. The Influence of Quality Circles on Attitudinal Outcomes Among Civil Engineering Personnel.

    Science.gov (United States)

    1985-09-01

    hygiene factors are related to job context. Herzberg recommends that jobs should be *enriched" by making the work more meaningful and interesting. He...34 Quality Progress, 13: 30-33 (1980b). Crawford, Maj Frederick L. "Quality Circles Results Measurement in the Federal Sector." Report to Air Command

  4. Dear Nel: Opening the Circles of Care (Letters to Nel Noddings)

    Science.gov (United States)

    Lake, Robert

    2012-01-01

    This collection is a moving tribute to Nel Noddings, a fascinating and influential scholar who has contributed greatly to numerous fields, including education, feminism, ethics, and the study of social justice and equity. "Dear Nel: Opening the Circles of Care" presents contributions from renowned teachers, educators, and activists, such as David…

  5. Quality circles to improve prescribing of primary care physicians. Three comparative studies.

    NARCIS (Netherlands)

    Wensing, M.J.P.; Broge, B.; Riens, B.; Kaufmann-Kolle, P.; Akkermans, R.P.; Grol, R.P.T.M.; Szecsenyi, J.

    2009-01-01

    PURPOSE: To determine the effectiveness of quality circles on prescribing patterns of primary care physicians in Germany and to explore the influence of specific factors on changes. METHODS: Three large non-randomised comparative studies were performed in primary care in Germany, with baseline measu

  6. Early-Years Teachers' Concept Images and Concept Definitions: Triangles, Circles, and Cylinders

    Science.gov (United States)

    Tsamir, Pessia; Tirosh, Dina; Levenson, Esther; Barkai, Ruthi; Tabach, Michal

    2015-01-01

    This study investigates practicing early-years teachers' concept images and concept definitions for triangles, circles, and cylinders. Teachers were requested to define each figure and then to identify various examples and non-examples of the figure. Teachers' use of correct and precise mathematical language and reference to critical and…

  7. "Telling Stories Long into the Night": Romantic Circles High School Project.

    Science.gov (United States)

    Walton, Brenda H.; Bork, Tara

    2001-01-01

    Reports on the authors' experiences in the Romantic Circles (RC) High School Project. Considers how RC High enables technology to be used as a tool in the study of literature and culture of the past, subjects that often seem dead and remote from a student's concern. (SG)

  8. Dinner Tables and Concentric Circles: A Harmony of Mathematics, Music, and Physics

    Science.gov (United States)

    Douthett, Jack; Krantz, Richard J.

    2008-01-01

    How should men and women be seated around a dinner table to maximize conversation between members of the opposite sex? What can be said about the distribution of points around two concentric circles? How are the white and black keys on the piano keyboard organized? What spin configuration in the Ising model minimizes energy? These four problems…

  9. Detection of Veneer Moisture Content by Surface-circle-shaped Resistance

    Institute of Scientific and Technical Information of China (English)

    Sa Chao; Du Hongbo; Zhang Biguang; Wang Guozhu

    2003-01-01

    This paper, with veneer as a particularly detected target, deals with a new method for detecting veneer moisture content. Surface resistance is measured by the fixed pressure, circle-shaped point and surface-touched detector. With the help of the computer, the veneer moisture and its distribution will be detected in a faster way with no harm to the veneer surface.

  10. Volunteers in Circles of Support and Accountability : Job demands, job resources, and outcome

    NARCIS (Netherlands)

    Höing, M.A.; Vogelvang, B.; Bogaerts, Stefan

    2016-01-01

    In Circles of Support and Accountability (CoSA), volunteers support a medium- to high-risk sex offender in his process toward desistance by developing a long-term empathic relationship. More knowledge is needed about the impact of this work on volunteers themselves. In a sample of 40 Dutch CoSA volu

  11. Learners' Perceptions toward Pronunciation Instruction in Three Circles of World Englishes

    Science.gov (United States)

    Kang, Okim

    2015-01-01

    From the perspective of World Englishes (i.e., varieties of English in different regions of the world), mutual intelligibility is a key issue for both listeners and speakers. Nevertheless, learners often have an idealized notion of native-speaker spoken norms and may be in favor of more prestigious inner circle models than others. This study…

  12. Statistics of Poincare recurrences for a class of smooth circle maps

    Energy Technology Data Exchange (ETDEWEB)

    Buric, Nikola [Department of Physics and Mathematics, Faculty of Pharmacy, University of Beograd, Vojvode Stepe 450, 11000 Belgrade (Serbia and Montenegro)]. E-mail: buric@phy.bg.ac.yu; Rampioni, Aldo [Department of Physics, University of Bologna, INFN Sezione di Bologna (Italy); Turchetti, Giorgio [Department of Physics, University of Bologna, INFN Sezione di Bologna (Italy)

    2005-03-01

    Statistics of Poincare recurrence for a class of circle maps, including sub-critical, critical, and super-critical cases, are studied. It is shown how the topological differences in the various types of the dynamics are manifested in the statistics of the return times.

  13. Reading and Analyzing Ethnographies through Literature Circles: A Praxis Model for Encouraging Multicultural Educators

    Science.gov (United States)

    Coles-Ritchie, Marilee

    2013-01-01

    This study explores the process of implementing literature circles using ethnographies as the texts to better prepare teachers for multicultural/ multilingual teaching contexts. Data collected by the course instructor and two of the participants, using a Critical Teacher Action Research (CTAR) methodology, indicate that participants think…

  14. Analytical methods for an elliptic singular perturbation problem In a circle

    NARCIS (Netherlands)

    Temme, N.M.

    2007-01-01

    We consider an elliptic perturbation problem in a circle by using the analytical solution that is given by a Fourier series with coefficients in terms of modified Bessel functions. By using saddle point methods we construct asymptotic approximations with respect to a small parameter. In particular

  15. Analytical methods for an elliptic singular perturbation problem in a circle

    NARCIS (Netherlands)

    Temme, N.M.

    2006-01-01

    We consider an elliptic perturbation problem in a circle by using the analytical solution that is given by a Fourier series with coefficients in terms of modified Bessel functions. By using saddle point methods we construct asymptotic approximations with respect to a small parameter. In particular w

  16. Runaway Climate Change as Challenge to the "Closing Circle" of Education for Sustainable Development

    Science.gov (United States)

    Selby, David; Kagawa, Fumiyo

    2010-01-01

    Education for sustainable development (ESD) is the latest and thickest manifestation of the "closing circle" of policy-driven environmental education. Characterised by definitional haziness, a tendency to blur rather than lay bare inconsistencies and incompatibilities, and a cozy but ill-considered association with the globalisation agenda, the…

  17. Penentuan Segmen Pasar Produk Private Label Makanan Siap Saji (Studi Pada Circle K Surabaya)

    OpenAIRE

    2015-01-01

    Segmentasi pasar memberikan peluang bagi peritel guna menyesuaikan produknya dengan permintaan konsumen. Penelitian ini bertujuan untuk mengetahui segmen pasar produk private label makanan siap saji di Circle K. Penelitian menggunakan analisis deskriptif untuk menggambarkan karakteristik konsumen dari variabel demografis, geografis, dan perilaku, analisis cluster K-Mean untuk menentukan segmen pasar dari variabel psikografis, analisis SWOT untuk menyusun faktor-faktor strategis perusahaan. Ha...

  18. Using Reading Circles Strategy for Developing Preparatory Students' Critical Reading Skills and Social Skills

    Science.gov (United States)

    Abdelrasoul, Mohamed Mahmoud Ibrahim

    2014-01-01

    The present study aimed at developing the necessary critical reading skills and social skills of the Egyptian EFL second year preparatory school students, through a proposed program based on using reading circles strategy. The study participants were 44 students from Sohag Experimental Preparatory School in Sohag Governorate. Instruments of the…

  19. Embedding and Distributing Constant Time Delay in Circle Time and Transitions.

    Science.gov (United States)

    Wolery, Mark; Anthony, Leslie; Caldwell, Nicola K.; Snyder, Erin D.; Morgante, James D.

    2002-01-01

    This study evaluated embedding and distributing constant time delay instructional trials into circle time and transitions between activities in a summer camp program. Three boys (ages 5-8) with disabilities or behavior problems participated. Results indicated the children acquired the behaviors they were taught and generalized the learned…

  20. Volunteers in circles of support and accountability : Job demands, job resources, and outcome

    NARCIS (Netherlands)

    Höing, M.A.; Vogelvang, B.; Bogaerts, Stefan

    2017-01-01

    In Circles of Support and Accountability (CoSA), volunteers support a medium- to high-risk sex offender in his process toward desistance by developing a long-term empathic relationship. More knowledge is needed about the impact of this work on volunteers themselves. In a sample of 40 Dutch CoSA volu

  1. NUMERICAL SOLUTIONS FOR THE TRANSIENT FLOW IN THE HOMOGENOUS CLOSED CIRCLE RESERVOIRS

    Institute of Scientific and Technical Information of China (English)

    周蓉; 刘曰武; 周富信

    2003-01-01

    There are many fault block fields in China. A fault block field consists of fault pools.The small fault pools can be viewed as the closed circle reservoirs in some case. In order to know the pressure change of the developed formation and provide the formation data for developing the fault block fields reasonably, the transient flow should be researched. In this paper, we use the automatic mesh generation technology and the finite element method to solve the transient flow problem for the well located in the closed circle reservoir, especially for the well located in an arbitrary position in the closed circle reservoir. The pressure diffusion process is visualized and the well-location factor concept is first proposed in this paper. The typical curves of pressure vs time for the well with different welllocation factors are presented. By comparing numerical results with the analytical solutions of the well located in the center of the closed circle reservoir, the numerical method is verified.

  2. Classroom community and discourse: How argumentation emerges during a Socratic circle

    Directory of Open Access Journals (Sweden)

    Alexis Carmela Brown

    2016-03-01

    Full Text Available Literacy and language development is a central aspect of educational theory and practice.  One area of literacy and rowlanguage research that has had a lot of attention is dialogic teaching (Bakhtin, 1984; Freire, 1970; Murphey, Wilkinson, Soter, Hennessey, & Alexander, 2009; Reznitskaya & Gregory, 2013.  However, there is limited research on how high school students use their classroom discourse to construct meaning, especially in argumentation.  The purpose of this data analysis is to investigate the emergence of argumentation literacy in a Socratic circle.  Socratic circles, a literacy practice consisting of two concentric circles of students focused around a piece of text, are used to provide students with the opportunity to co-construct meaning through classroom dialogue (Copeland, 2005.  The emergence and construction of argumentation is analyzed by applying discourse analysis to a video of a high school classroom,.  Findings from this analysis reveal that through the use of exploratory talk, three discourse patterns emerge that are in line with argumentation practices: (1 generalizations, (2 communicative struggles, and (3 co-construction of ideas.  Results of the analysis are discussed to inform theory and instruction on dialogic teaching and the use of Socratic circles to develop argumentation-related forms of literacy.

  3. A Study of Traditional Circle Games Played in Public School Kindergartens across the United States.

    Science.gov (United States)

    Rothlein, Liz; And Others

    1988-01-01

    Investigates traditional circle games played in 203 public school kindergartens in 35 states. Results indicate that music/movement and racing games were the major game categories; the most common frequency and duration was three times per week for 20 minutes; and the purposes of the games were to have fun, and to foster social, physical motor, and…

  4. 17th century arguments for the impossibility of the indefinite and the definite circle quadrature

    DEFF Research Database (Denmark)

    Lützen, Jesper

    2014-01-01

    The classical problem of the quadrature (or equivalently the rectification) of the circle enjoyed a renaissance in the second half of the 17th century. The new analytic methods provided the means for the discovery of infinite expressions of and for the first attempts to prove impossibility statem...

  5. Strategic Sustainability Management for Enhancing Corporate Value: in the context of Korean Business Circles

    NARCIS (Netherlands)

    Y-G. Ahn

    2007-01-01

    textabstractIn line with the growing importance of Corporate Sustainability Management (CSM) in business circles, the linkages between CSM, corporate values and performance is becoming increasingly higher on the agenda both for internal corporate management purposes and for external relations for co

  6. Approximation by polynomials and Blaschke products having all zeros on a circle

    CERN Document Server

    Farmer, David W

    2010-01-01

    We show that a nonvanishing analytic function on a domain in the unit disc can be approximated by (a scalar multiple of) a Blaschke product whose zeros lie on a prescribed circle enclosing the domain. We also give a new proof of the analogous classical result for polynomials. A connection is made to universality results for the Riemann zeta function.

  7. Quasi-symmetric Conjugacy of Blaschke Products on the unit Circle

    DEFF Research Database (Denmark)

    Petersen, Carsten Lunde

    2007-01-01

    Let B be a Blaschke product for which the restriction to the unit circle 1 is a degree d > 1 covering. We prove that B is quasi-symmetrically conjugate to z zd on 1, if all its periodic points in 1 are repelling and if 1 does not intersect the -limit set of any recurrent critical point for B....

  8. The Three Circles Redux: A Market-Theoretic Perspective on World Englishes

    Science.gov (United States)

    Park, Joseph Sung-Yul; Wee, Lionel

    2009-01-01

    While Kachru's Three Circles model of World Englishes (Kachru 1985, 1986; Kachru and Nelson 1996) has been highly influential in highlighting the changing distribution and functions of English, it has also been criticized for its inability to account for the heterogeneity and dynamics of English-using communities, and for perpetuating the very…

  9. Constructing Knowledge about the Trigonometric Functions and Their Geometric Meaning on the Unit Circle

    Science.gov (United States)

    Altman, Renana; Kidron, Ivy

    2016-01-01

    Processes of knowledge construction are investigated. A learner is constructing knowledge about the trigonometric functions and their geometric meaning on the unit circle. The analysis is based on the dynamically nested epistemic action model for abstraction in context. Different tasks are offered to the learner. In his effort to perform the…

  10. Literature Circles: Meeting Reading Standards, Making Personal Connections, and Appreciating Other Interpretations

    Science.gov (United States)

    Latendresse, Carter

    2004-01-01

    This article discusses a reading instruction applicable to widely diverse classrooms, because it weaves together dynamic strands from three approaches to teaching reading: literature circle method, reciprocal teaching, and modern literary theories. The author presents three stages to achieve reading success: (1) applying the key features of…

  11. The Schur algorithm for generalized Schur functions III : J-unitary matrix polynomials on the circle

    NARCIS (Netherlands)

    Alpay, Daniel; Azizov, Tomas; Dijksma, Aad; Langer, Heinz

    2003-01-01

    The main result is that for J = ((1)(0) (0)(-1)) every J-unitary 2 x 2-matrix polynomial on the unit circle is an essentially unique product of elementary J-unitary 2 x 2-matrix polynomials which are either of degree 1 or 2k. This is shown by means of the generalized Schur transformation introduced

  12. PT-invariance and representations of the Temperley-Lieb algebra on the unit circle

    CERN Document Server

    Korff, Christian

    2007-01-01

    We present in detail a recent conjecture on self-adjoint representations of the Temperley-Lieb algebra for particular values on the unit circle. The formulation in terms of graphical calculus is emphasized and discussed for several examples. The role of PT (parity and time reversal) invariance is highlighted as it might prove important for generalising the construction to other cases.

  13. Quantization of Sine-Gordon solitons on the circle: semiclassical vs. exact results

    CERN Document Server

    Pawellek, Michael

    2008-01-01

    We consider the semiclassical quantization of sine-Gordon solitons on the circle with periodic and anti-periodic boundary conditions. The 1-loop quantum corrections to the mass of the solitons are determined using zeta function regularization in the integral representation. We compare the semiclassical results with exact numerical calculations in the literature and find excellent agreement even outside the plain semiclassical regime.

  14. "Slow Down, You Move Too Fast:" Literature Circles as Reflective Practice

    Science.gov (United States)

    Sanacore, Joseph

    2013-01-01

    Becoming an effective literacy learner requires a bit of slowing down and appreciating the reflective nature of reading and writing. Literature circles support this instructional direction because they provide opportunities for immersing students in discussions that encourage their personal responses. When students feel their personal responses…

  15. An Analysis of Elementary School Children's Fractional Knowledge Depicted with Circle, Rectangle, and Number Line Representations

    Science.gov (United States)

    Tunç-Pekkan, Zelha

    2015-01-01

    It is now well known that fractions are difficult concepts to learn as well as to teach. Teachers usually use circular pies, rectangular shapes and number lines on the paper as teaching tools for fraction instruction. This article contributes to the field by investigating how the widely used three external graphical representations (i.e., circle,…

  16. Circle of Security in Child Care: Putting Attachment Theory into Practice in Preschool Classrooms

    Science.gov (United States)

    Cooper, Glen; Hoffman, Kent; Powell, Bert

    2017-01-01

    This article describes the Circle of Security-Classroom (COS-C) approach to applying attachment theory in preschool settings. Early childhood is an incubator for a wide range of development including the underpinnings of school readiness. Secure teacher-child relationships support this process. However, most preschool staff members lack guidance…

  17. The Arithmetic of Elliptic Fibrations in Gauge Theories on a Circle

    CERN Document Server

    Grimm, Thomas W; Klevers, Denis

    2016-01-01

    The geometry of elliptic fibrations translates to the physics of gauge theories in F-theory. We systematically develop the dictionary between arithmetic structures on elliptic curves as well as desingularized elliptic fibrations and symmetries of gauge theories on a circle. We show that the Mordell-Weil group law matches integral large gauge transformations around the circle in Abelian gauge theories and explain the significance of Mordell-Weil torsion in this context. We also use Higgs transitions and circle large gauge transformations to introduce a group law for genus-one fibrations with multi-sections. Finally, we introduce a novel arithmetic structure on elliptic fibrations with non-Abelian gauge groups in F-theory. It is defined on the set of exceptional divisors resolving the singularities and divisor classes of sections of the fibration. This group structure can be matched with certain integral non-Abelian large gauge transformations around the circle when studying the theory on the lower-dimensional ...

  18. Using Social Networks and ICTs to Enhance Literature Circles: A Practical Approach

    Science.gov (United States)

    Walker, Andrea

    2010-01-01

    The purpose of this paper is to describe and demonstrate how social networks such as "Facebook" and "Goodreads", and information and communication technologies (ICTs) tools like laptops and iPods can support and enhance literature circles. The innovation described is implemented by the library and aims to promote reading for…

  19. Deposit model for volcanogenic uranium deposits

    Science.gov (United States)

    Breit, George N.; Hall, Susan M.

    2011-01-01

    Volcanism is a major contributor to the formation of important uranium deposits both close to centers of eruption and more distal as a result of deposition of ash with leachable uranium. Hydrothermal fluids that are driven by magmatic heat proximal to some volcanic centers directly form some deposits. These fluids leach uranium from U-bearing silicic volcanic rocks and concentrate it at sites of deposition within veins, stockworks, breccias, volcaniclastic rocks, and lacustrine caldera sediments. The volcanogenic uranium deposit model presented here summarizes attributes of those deposits and follows the focus of the International Atomic Energy Agency caldera-hosted uranium deposit model. Although inferred by some to have a volcanic component to their origin, iron oxide-copper-gold deposits with economically recoverable uranium contents are not considered in this model.

  20. New mechanized system for circle spraying of oil palms seedling emergence

    Directory of Open Access Journals (Sweden)

    Darius El Pebrian

    2012-04-01

    Full Text Available A new machine system has been designed, developed and evaluated for extensive circle spraying of oil palms (Elaeis guineensis Jacq. in an effort to overcome the inefficient spraying problem with the conventional spraying system. The machine system consists of a four-wheeled drive 4WD prime mover with front mounted machine attachments for the circle spraying operation. The configuration of the circle spraying attachment consists of a hexagonal curved spray boom, lifting arm, opening-tilting mechanism unit, storage tank, spray pump, solid cone nozzles, and associate hydraulic system. Field performance tests on the machine system showed an average effective field capacity of 7.89 ha per man per day and when compared to the earlier reported effective field capacity of the walking spray-operated equipment using Serena LT16 knapsack sprayer; a difference of 1.97 time for circle spraying of mature palms grove. Reduction in the human energy expenditure of 101.28 kJ man-1 h-1 or 10.68 % but an increase in the spraying cost of 1.53 USD ha-1 or 24.9 % were obtained with the machine system against the walking spraying-operated equipment using Serena LT16 knapsack sprayer. Justification for machine system to be cost effective could be satisfied if the present effective field capacity is increased to 1.263 time with good skilled operator or if the current R&D cost is reduced to 0.41 time. This is because the improved field capacity of new machine system could not rationalize its current R&D cost. Admittedly, the machine system has great potential to overcome the limitations with the current employed machine/equipment in the circle spraying operation of oil palms in the plantation.

  1. Enhanced x-ray resolving power achieved behind the focal circles of Cauchois spectrometers.

    Science.gov (United States)

    Seely, John F; Hudson, Lawrence T; Holland, Glenn E; Henins, Albert

    2008-05-20

    Maintaining high resolving power is a primary challenge in hard x-ray spectroscopy of newly developed bright and transient x-ray sources such as laser-produced plasmas. To address this challenge, the line widths in x-ray spectra with energies in the 17 keV to 70 keV range were recorded by positioning the detectors on and behind the focal circles of Cauchois type transmission-crystal spectrometers. To analyze and understand the observed line widths, we developed a geometrical model that accounts for source broadening and various instrumental broadening mechanisms. The x-ray sources were laboratory Mo or W electron-bombarded anodes, and the spectra were recorded on photostimulable phosphor image plates. For these relatively small x-ray sources, it was found that when the detector was placed on or near the focal circle, the line widths were dominated by the effective spatial resolution of the detector. When the detector was positioned beyond the focal circle, the line widths were determined primarily by source-size broadening. Moreover, the separation between the spectral lines increased with distance behind the focal circle faster than the line widths, resulting in increased resolving power with distance. Contributions to line broadenings caused by the crystal thickness, crystal rocking curve width, geometrical aberrations, and natural widths of the x-ray transitions were in all cases smaller than detector and source broadening, but were significant for some spectrometer geometries. The various contributions to the line widths, calculated using simple analytical expressions, were in good agreement with the measured line widths for a variety of spectrometer and source conditions. These modeling and experimental results enable the design of hard x-ray spectrometers that are optimized for high resolving power and for the measurement of the x-ray source size from the line widths recorded behind the focal circle.

  2. Coefficients calculation of the best linear method for recovery of bounded analytic functions in a circle

    Directory of Open Access Journals (Sweden)

    Ovchintsev Mikhail Petrovich

    2014-04-01

    Full Text Available This paper considers the problem of optimal recovery of bounded analytic functions. Namely, the values of these functions are determined at the point from their values at n given points lying in the unit circle. At first, we recall the necessary basic concepts: error of approximation by some method (which is a complex function of n complex variables, the best approximation method. Some theorems from the works of K.U. Osipenko are discussed: on the existence of a best linear approximation method and on calculating the error of best recovery method. After that we write out the formula for finding the error of best approximation method of bounded analytic functions in a unit circle. The lemma of conformal invariance of optimal recovery problem of these functions follows. We prove that under conformal mapping of the unit circle onto itself the error of the best approximation method before mapping coincides with the error of the best approximation method after mapping. It is also proved that a linear best method after conformal mapping coincides with the linear best restore method before this mapping (wherein the problem of optimal recovery after mapping is considered on the images of n given points lying in the original unit circle. Finally, we consider the problem of optimal recovery of bounded analytic functions in a circle in special case when the given points coincide with the vertices of a regular n-gon, and the point itself coincides with its center (which coincides with the origin. We prove that all the coefficients of the best linear method in this case are identical (wherein we apply the lemma of conformal invariance of optimal recovery problem of bounded analytic functions. The formulas for calculating these coefficients are given (for this purpose we write out an integral. The result is the smart, simple formulas for calculating the coefficients of the best linear approximation method for this particular case.

  3. 一种工程图中圆的整体识别方法%A Method of Global Recogniting Circles about Engineering Drawing

    Institute of Scientific and Technical Information of China (English)

    张显全

    2003-01-01

    In study on recognition of engineering drawings,the recognition for circle is a key technology. A newmethod of global recognition circle about engineering drawing is presented. Image of engineering drawing is process-ed. It depends on the circular arc of the image,the circle or circular arc is global recognized by tracing the circle direc-tion and region. Experimental results show that the method is feasibility and availability.

  4. Water sediment separation mechanism and design parameters of conical circles in shuttle-conical tubes%梭锥管内锥圈水沙分离机理及锥圈设计参数

    Institute of Scientific and Technical Information of China (English)

    李琳; 谭义海; 杨海华; 王苗; 邱秀云

    2013-01-01

    According to the sediment movement mechanics and precipitation theory,the influences of conical circles in shuttle-conical tubes on sediment deposition characteristics are analyzed based on their unique sediment settlement characteristics.Taking floccules as the study object,the angle range of the conical circles to meet the sediment deposition at greater speed along their inner surface is presented by means of the mechanical analysis and statistical regression.Based on the precipitation theory,the deduced best angle of the conical circles is 45°.The influences of length and spacing of the conical circles on sediment settling velocity are also theoretically derived.The results show that the shuttle-conical tubes can make more sediment settle than the ordinary devices under the same water and sand conditions.The sediment settling velocity relates to the ratio of the length to the spacing.The larger the ratio is,the higher is the sediment settling velocity.Therefore,a larger ratio of the length to the spacing of the conical circles is suggested.%从梭锥管内特有的泥沙沉降特性出发,根据泥沙运动力学和沉淀理论,重点分析梭锥管内锥圈对泥沙沉降特性的影响.以絮团为研究对象,通过力学分析和数值分析给出了满足泥沙不淤积且以较大速度沿锥圈内表面下滑的锥圈倾角范围,并根据沉淀理论推导出锥圈的最佳倾角为45°.理论推导出锥圈长度和锥圈间距,研究这两个参数对泥沙沉降速度的影响,结果表明在相同的水沙条件下,梭锥管可使更多泥沙发生沉降,其沉降能力大于没有加锥圈的普通容器.泥沙沉降速度与锥圈长度和锥圈间距的比值有关,比值越大,泥沙沉降速度越大,设计时建议选择较大的比值.

  5. Study of cliff activity dominating the gas and dust comae of comet 67P/Churyumov-Gerasimenko during the early phase of the Rosetta mission using ROSINA/COPS and OSIRIS data

    Science.gov (United States)

    Marschall, Raphael; Su, Cheng-Chin; Liao, Ying; Rubin, Martin; Wu, Jong-Shinn; Thomas, Nicolas; altwegg, kathrin; Sierks, Holger; OSIRIS, ROSINA

    2016-10-01

    The study by [1] has proposed the idea that the cometary dust jets in the northern hemisphere of comet 67P/Churyumov-Gerasimenko arise mainly from rough cliff like terrain. Using our 3D gas and dust dynamics coma model [2] we have run simulations targeting the question whether areas with high gravitational slopes alone can indeed account for both the ROSINA/COPS and the OSIRIS data obtained for mid August to end October 2014.The basis of our simulations is the shape model "SHAP4S" of [3]. Surface temperatures have been defined using a simple 1-D thermal model (including insolation, shadowing, thermal emission, sublimation but neglecting conduction) computed for each facet of the shape model allowing a consistent and known description of the gas flux and its initial temperature. In a next step we use the DSMC program PDSC++ [4] to calculate the gas properties in 3D space. The gas solution can be compared with the in situ measurements by ROSINA/COPS. In a subsequent step dust particles are introduced into the gas flow to determine dust densities and with a column integrator and Mie theory dust brightnesses that can be compared to OSIRIS data.To examine cliff activity we have divided the surface into two sets. One with gravitational slopes larger than 30° which we call cliffs and one with slopes less than 30° which we shall call plains. We have set up two models, "cliff only" and "plains only" where the respective set of areas are active and the others inert. The outgassing areas are assumed to be purely insolation driven. The "cliffs only" model is a statistically equally good fit to the ROSINA/COPS data as the global insolation driven model presented in [2]. The "plains only" model on the other hand is statistically inferior to the "cliffs only" model. We found in [2] that increased activity in the Hapi region (called inhomogeneous model) of the comet improves the fit of the gas results significantly. We can show in this study that a "cliffs + Hapi" model fits the

  6. On the Construction of Mohr Stress Circle and a Graphic Method in Representing the Stress Components on Different Oblique Planes

    Institute of Scientific and Technical Information of China (English)

    Zhubin He; Z. R. Wang; Kunpeng Kang

    2004-01-01

    The Mohr stress circle for three-dimensional stress is usually determined by equations,which is lack of intuitionistic meanings and difficult to understand. In this paper, the construction of Mohr stress circle is illustrated directly by numerical method. The shortcoming of Mohr stress circle in representing the stress components on different oblique planes for three-dimensional stress is analyzed. A three-dimensional figure is given to describe the variation of normal and shear stress on different oblique planes at one point for the first time.

  7. An Investigation of Seventh Grade Students’ Performances on Conceptual, Procedural and Graphical Problems Regarding Circles

    Directory of Open Access Journals (Sweden)

    Lütfi İncikabı

    2015-04-01

    Full Text Available The purpose of this study is to determine seventh grade students’ preferences among the procedural, conceptual and graphical questions in the subject of circles, to define their success levels in their preferences, and to compare students’ success levels in one question type with their performances in other question types. The methodology adopted during this research was case study. Based on criterion-based purposive sampling strategy, 98 middle school students were selected as the participants. Data were collected through an achievement test consisting of nine questions (three per question type. The results obtained from the study indicated that students mostly preferred graphical question types. Moreover, majority of students could not succeeded high levels in their preferred question types. In addition, the students performed better in graphical question types; however, the failure in procedural question types was remarkable. Keywords: Multiple representations, middle school students, mathematics education, circles

  8. Integrated photonic 3D waveguide arrays for quantum random walks on a circle

    CERN Document Server

    Linjordet, Trond

    2010-01-01

    Quantum random walks (QRWs) can be used to perform both quantum simulations and quantum algorithms. In order to exploit this potential, quantum walks on different types of graphs must be physically implemented. To this end this we design, model and experimentally fabricate, using the femtosecond laser direct-write technique, a 3D tubular waveguide array within glass to implement a photonic quantum walk on a circle. The boundary conditions of a QRW on a circle naturally suggests a 3D waveguide implementation - allowing much simpler device design than what could be achieved using a 2D waveguide architecture. We show that, in some cases, three-dimensional photonic circuits can be more suited to the simulation of complex quantum phenomena.

  9. Pythagorean hodograph spline spirals that match G3 Hermite data from circles

    KAUST Repository

    Li, Zhong

    2015-04-01

    A construction is given for a G3 piecewise rational Pythagorean hodograph convex spiral which interpolates two G3 Hermite data associated with two non-concentric circles, one being inside the other. The spiral solution is of degree 7 and is the involute of a G2 convex curve, referred to as the evolute solution, with prescribed length, and composed of two PH quartic curves. Conditions for G3 continuous contact with circles are then studied and it turns out that an ordinary cusp at each end of the evolute solution is required. Thus, geometric properties of a family of PH polynomial quartics, allowing to generate such an ordinary cusp at one end, are studied. Finally, a constructive algorithm is described with illustrative examples.

  10. Strange non-chaotic attractors in quasiperiodically forced circle maps: Diophantine forcing

    CERN Document Server

    Jäger, T

    2011-01-01

    We study parameter families of quasiperiodically forced (qpf) circle maps with Diophantine frequency. Under certain C1-open conditions concerning their geometry, we prove that these families exhibit nonuniformly hyperbolic behaviour, often referred to as the existence of strange nonchaotic attractors, on parameter sets of positive measure. This provides a nonlinear version of results by Young on quasiperiodic SL (2;R)-cocycles and complements previous results in this direction which hold for sets of frequencies of positive measure, but did not allow for an explicit characterisation of these frequencies. As an application, we study a qpf version of the Arnold circle map and show that the Arnold tongue corresponding to rotation number 1/2 collapses on an open set of parameters. The proof requires to perform a parameter exclusion with respect to some twist parameter and is based on the multiscale analysis of the dynamics on certain dynamically defined critical sets. A crucial ingredient is to obtain good control...

  11. Shared inputs and desynchrony in elliptic bursters: from slow passage to discontinuous circle maps

    CERN Document Server

    Lajoie, Guillaume

    2010-01-01

    What input signals will lead to synchrony vs. desynchrony in a group of biological oscillators? This question connects with both classical dynamical sys- tems analyses of entrainment and phase locking and with emerging studies of stimulation patterns for controlling neural network activity. Here, we focus on the response of a population of uncoupled, elliptically bursting neurons to a com- mon pulsatile input. We extend a phase reduction from the literature to capture inputs of varied strength, leading to a circle map with discontinuities of various orders. In a combined analytical and numerical approach, we apply our results to both a normal form model for elliptic bursting and to a biophysically-based model for neurons of the basal ganglia. We find that, depending on the period and amplitude of inputs, the response can either appear chaotic (with provably positive Lyaponov exponent for the associated circle maps), or periodic with a broad range of phase-locked periods. Throughout, we discuss the critical un...

  12. The Study of Transcendence Circles in Golshan-e Raz and Mafatih al-E’jaz

    Directory of Open Access Journals (Sweden)

    M Panahi

    2014-03-01

    Jungian attitude to the system of these circles leads to the discovery of their psychological aspect. The process of individuation is mapped onto the man’s revelation and he who has reached the center projects his progression on the system of being. Thus, the being also should move from individuation to center and experiences divine kindness and wrath via god’s glory and beauty manifestations.

  13. Right-invariant Sobolev metrics ${H}^{s}$ on the diffeomorphisms group of the circle

    CERN Document Server

    Escher, Joachim

    2012-01-01

    We study the geodesic flow on the diffeomorphisms group of the circle with respect to the right-invariant metric induced by the fractional Sobolev norm $H^s$ for $s\\ge1/2$. We show that the corresponding initial value problem possesses a maximal solution in the smooth category and that the Riemannian exponential mapping is a smooth diffeomorphism from a neighbourhood of 0 in $C^{\\infty}(S)$ onto a neighbourhood of the identity in $Diff^{\\infty}(S)$.

  14. Infinite-Dimensional Feedback Systems: The Circle Criterion and Input-to-State Stability

    OpenAIRE

    2008-01-01

    An input-to-state stability theory, which subsumes results of circle criterion type, is developed in the context of a class of infinite-dimensional systems. The generic system is of Lur’e type: a feedback interconnection of a well-posed infinite-dimensional linear system and a nonlinearity. The class of nonlinearities is subject to a (generalized) sector condition and contains, as particular subclasses, both static nonlinearities and hysteresis operators of Preisach type.

  15. Peak Trekking of Hierarchy Mountain for the Detection of Cerebral Aneurysm using Modified Hough Circle Transform

    OpenAIRE

    Mitra, Jubin

    2013-01-01

    The Circle of Willis is in the junction of two carotid arteries and two vertebral arteries that supply the brain with nutrition. Junctions where these arteries come together may develop weak spots that can balloon out and fill with blood, creating aneurysms. These sac-like areas may leak or rupture, spilling blood into surrounding tissues which may cause artery spasm leading to potential stroke or even death. Clipping and coiling are two treatment options preferred by neurosurgeon which requi...

  16. Common Directions in Caucasian Chalk Circle and Keşanlı Ali Destanı

    OpenAIRE

    ODACI, Serdar

    2016-01-01

    Epic Theater founded by Bertolt Brecht influenced world literaturein the half of 20th century. Epic theater is against to Aristothalesian Theater.Naturally Brehct's plays were translated to Turkish and were presented. SuchTurkish writers as Haldun Taner and Vasıf Öngeren wrote play according toepic theater concept. In this paper common aspects in Keşanlı Ali Destanıand Caucasian Chalk Circle are examined.

  17. "Common Directions in Caucasian Chalk Circle and Keşanlı Ali Destanı"

    OpenAIRE

    ODACI, Serdar

    2010-01-01

    Epic Theater founded by Bertolt Brecht influenced world literature in the half of 20th century. Epic theater is against to Aristothalesian Theater. Naturally Brehct's plays were translated to Turkish and were presented. Such Turkish writers as Haldun Taner and Vasıf Öngeren wrote play according to epic theater concept. In this paper common aspects in Keşanlı Ali Destanı and Caucasian Chalk Circle are examined.

  18. Investigating the Use of Circle in Gear Cutting as a Substitute to Involute Profile

    Directory of Open Access Journals (Sweden)

    A.D. Kibet

    2012-05-01

    Full Text Available Gears are used in various machines and industries for transportation and transmission of power. Other uses are in consumer electronics and many machines used in homes like the washing machines, electric drills and kitchen appliances. Gears come in different sizes ranging from a module of 0.5 to 100 mm. Currently there is a problem of accurately machining gears. This is due to inaccurate positioning of the blank and cutter. The objective of the study was to investigate and determine the appropriate way of producing quality and accurate gears most economically through the use of a circle as a substitute to involute profile in gear cutting. Two different gears of same dimensional characteristics were cut; one using a Computer Numerical Control machine utilizing circle profile and the other using conventional milling machine. Dimensional comparisons were made of the two cut gears against an actual involute profile to determine the margin of error. The circle involute profile made using CNC was found to be exactly as the true involute profile though an error of 0.078 mm was observed in some sections of the profile. For the hobbing case, it was impossible to accurately machine the actual depth and as such, the intended depth of 7.32 was surpassed by 0.2 mm. The tooth was thicker throughout the length of the profile and the fillet radii lucked homogeneity. The involute circle approach was therefore successful and as such can benefit all CNC users and gear cutters in producing accurate gears cheaply.

  19. The partition function of a multi-component Coulomb gas on a circle

    Energy Technology Data Exchange (ETDEWEB)

    Jokela, Niko; Keski-Vakkuri, Esko [Helsinki Institute of Physics, University of Helsinki, PO Box 64, FIN-00014 (Finland); Jaervinen, Matti [University of Southern Denmark, Campusvej 55, DK-5230 Odense M (Denmark)], E-mail: niko.jokela@helsinki.fi, E-mail: mjarvine@ifk.sdu.dk, E-mail: esko.keski-vakkuri@helsinki.fi

    2008-04-11

    We study a two-dimensional Coulomb gas consisting of a mixture of particles carrying various positive multiple integer charges, confined on a unit circle. We consider the system in the canonical and grand canonical ensembles, and attempt to calculate the partition functions analytically, using Toeplitz and confluent Vandermonde determinants. Just like in the simple one-component system (Dyson gas), the partition functions simplify at special temperature {beta} = 2, allowing us to find compact expressions for them.

  20. INTEGRATING SIX-SIGMA AND HEALTHCARE QUALITY IMPROVEMENT CIRCLES IN REDUCING THE NEEDLE STICKING

    OpenAIRE

    Sen-Ji Chen; Frank F. C. Pan; Hsuen C. H. Chen

    2008-01-01

    Six-Sigma (SS) is a managerial philosophy used in detecting the error rate of a particular (set) of activities. This research applies six sigma concepts in dealing with troublesome needle-stick events that occurred in a Taiwan hospital. This research integrates several advanced managerial instruments into one framework, grounded in Continuous Quality Improvement and Total Quality Management. This framework combines Six-Sigma and Health Quality Improvement circle practices. The project suggest...

  1. A topological state sum model for a scalar field on the circle

    CERN Document Server

    Kerr, Steven

    2016-01-01

    This paper is a follow-up to a previous paper on fermions. A simple state sum model for a scalar field on a triangulated 1-manifold is constructed. The model is independent of the triangulation and gives exactly the same partition function as the continuum functional integral with zeta function regularisation. For a certain choice of gauge group, the state sum model on the circle is equivalent to the path integral for the simple harmonic oscillator.

  2. On Linear Combinations of Two Orthogonal Polynomial Sequences on the Unit Circle

    Directory of Open Access Journals (Sweden)

    Suárez C

    2010-01-01

    Full Text Available Let be a monic orthogonal polynomial sequence on the unit circle. We define recursively a new sequence of polynomials by the following linear combination: , , . In this paper, we give necessary and sufficient conditions in order to make be an orthogonal polynomial sequence too. Moreover, we obtain an explicit representation for the Verblunsky coefficients and in terms of and . Finally, we show the relation between their corresponding Carathéodory functions and their associated linear functionals.

  3. Analysis of Laser Diode Pumped Solid-State Laser Resonator by the Transform Circle Approach

    Institute of Scientific and Technical Information of China (English)

    SONG Feng; ZHANG Guang-Yin; XU Jing-Jun; ZHANG Chao-Bo

    2000-01-01

    The typical laser characteristics of a laser diode pumped solid-state laser with a Z-type resonator structure are analyzed by the transform circle approach. Laser waists change with the thermal focus length of the lasing medium so that the output power becomes unstable. In particular, there is a very unstable operation region when the pump power is of medium magnitude. A method is put forward to avoid this situation.

  4. Deposition of antimony telluride thin film by ECALE

    Institute of Scientific and Technical Information of China (English)

    GAO; Xianhui; YANG; Junyou; ZHU; Wen; HOU; Jie; BAO; Siqian; FAN; Xi'an; DUAN; Xingkai

    2006-01-01

    The process of Sb2Te3 thin film growth on the Pt substrate by electrochemical atomic layer epitaxy (ECALE) was studied. Cyclic voltammetric scanning was performed to analyze the electrochemical behavior of Te and Sb on the Pt substrate. Sb2Te3 film was formed using an automated flow deposition system by alternately depositing Te and Sb atomic layers for 400 circles. The deposited Sb2Te3 films were characterized by XRD, EDX, FTIR and FESEM observation. Sb2Te3 compound structure was confirmed by XRD pattern and agreed well with the results of EDX quantitative analysis and coulometric analysis. FESEM micrographs showed that the deposit was composed of fine nano particles with size of about 20 nm. FESEM image of the cross section showed that the deposited films were very smooth and dense with thickness of about 190 nm. The optical band gap of the deposited Sb2Te3 film was determined as 0.42 eV by FTIR spectroscopy, and it was blue shifted in comparison with that of the bulk Sb2Te3 single crystal due to its nanocrystalline microstructure.

  5. Laser controlled deposition of metal microstructures via nondiffracting Bessel beam illumination

    Science.gov (United States)

    Drampyan, Rafael; Leonov, Nikita; Vartanyan, Tigran

    2016-04-01

    The technique of the laser controlled deposition of sodium and rubidium deposits on the sapphire substrate is presented. The metals were deposited on the clean sapphire substrate from the vapor phase contained in the evacuated and sealed cell. We use an axicon to produce a non-diffracting Bessel beam out of the beam got from the cw diode laser with 200 mW power at the wavelength of 532 nm. After 30 minutes of the laser-controlled deposition the substrates were examined in the optical microscope. The obtained metal deposits form the sharp-cut circles with the pitch of 10 μm, coincident with the tens of dark rings of the Bessel beam. Reduction of the laser power leads to the build up of the continuous metal film over the whole substrate.

  6. Spindle error motion measurement using concentric circle grating and phase modulation interferometers

    Science.gov (United States)

    Aketagawa, M.; Madden, M.; Uesugi, S.; Kumagai, T.; Maeda, Y.; Okuyama, E.

    2012-11-01

    In the conventional methods to measure radial, axial and angular motions of spindles, complicated artifacts with relative large volume (such as two balls linked with a cylinder) are required. Small volume artifact is favorable from the viewpoint of the accurate and practical measurement of the spindle motion. This paper describes a concurrent measurement of spindle radial, axial and angular motions using concentric circle grating and phase modulation interferometers. In the measurement, the concentric circle grating with fine pitch is installed on top of the spindle of interest. The grating is a reference artifact in the method. Three optical sensors are fixed over the concentric circle grating, and observe the proper positions of the grating. The optical sensor consists of a frequency modulated laser diode as a light source, and two interferometers. One interferometer observes an interference fringe between reflected light form a fixed mirror and 0-th order diffraction light from the grating to measure the axial motion. Another interferometer observes an interference fringe between +/-2nd diffraction lights from the grating to measure the radial motion. Using three optical sensors, three radial displacements and three axial displacements of the proper observed position of the grating can be measured. From these measured displacements, radial, axial and angular motions of the spindle can be calculated concurrently. In the paper, a measurement instrument, a novel fringe interpolation technique by sinusoidal phase modulation and experimental results are discussed.

  7. Design of Circle Array Pattern for Transparent Nanomesh-Type Electrodes.

    Science.gov (United States)

    Shin, Seungsu; Ganorkar, Shraddha; Kim, Jungyoon; Kim, Young-Hwan; Kim, Yong Tae; Kim, Seong-Il

    2015-10-01

    In this study, we report simulation results for the optical properties of nanomesh-type electrodes for transparent electrode. Usually, indium tin oxide (ITO) is commonly used for transparent conductor to solar cell, display, LED and other electronic modules. However, the cost is high due to the rarity of indium. An alternative way is use of transparent nanomesh-type metal electrode for solar cell. Finite different time domain (FDTD) method was used to simulate and analyze their optical properties. Various array patterns (square, circle and circle hexagonal array) of metal on glass (SiO2) substrates were designed and their properties of transmission and reflection were simulated by using the broad band (λ = 300~1200 nm) plane wave source. To compare basic characteristics of each pattern, various structural parameters such as hole diameter, pitch and metal thickness were applied. The effect of three typical metals, such as Ag, Au, and Al was also compared. In the results, we will discuss about large dip of transmission appeared at the particular wavelength region from the circle array pattern, which is design with pitch of 500 nm at the wavelength range 700 to 800 nm. The surface plasmonpolaritons (SPP) effect can be the cause of large dip and we could find a broad and high transmission from the properly designed in nanomesh-type electrodes, which was calculated as a function of wavelength.

  8. Linear Determination of a Camera's Intrinsic Parameters Using Two Intersecting Circles

    Directory of Open Access Journals (Sweden)

    Xu Chen

    2014-03-01

    Full Text Available An approach using two intersecting circles is proposed as a linear approach for determining a camera's intrinsic parameters. The two intersecting coplanar circles have four intersection points in the projective plane: two real points and two circular points. In the image plane, the diagonal triangle - on which the image of the four intersection points composes a complete quadrangle - is a self-polar triangle for the projection curves of the circles. The vertex of the self-polar triangle is the null space of the degenerate conic formed by the image of the four intersection points. By solving the three vertices of the self-polar triangle using the image coordinates of the two real intersection points, the degenerate conic can be obtained. The image of the two circular points is then computed from the intersection points of the degenerate conic. Using the image of the circular points from the three images of the same planar pattern with different directions, the intrinsic parameters can be linearly determined.

  9. The Archaeoastronomy of Tomnaverie Recumbent Stone Circle: A Comparison of Methodologies

    Directory of Open Access Journals (Sweden)

    Liz Henty

    2014-09-01

    Full Text Available The way we view the past is constantly modified by new evidence and methodological advances. Archaeological data is gleaned from the ground and archaeoastronomical evidence considers the use of the sky in relation to the archaeological record. Since the beginning of the 20th  century the two disciplines of archaeology and archaeoastronomy have flirted with one another but there has never been a satisfactory marriage. This paper looks at the Recumbent Stone Circles (RSCs of north-east Scotland to examine the methodologies, and compare the results, of both disciplines. The RSCs are a distinctive type of stone circle characterised by a large recumbent stone which is flanked on either side by a tall pillar. This recumbent arrangement is almost invariably located in the south-west of the circle. RSCs are generally located near the summits of low hills and enjoy clear horizon views. Over the years they have been the subject of extensive research. This research will be reviewed and Tomnaverie RSC will be singled out as a special case study to examine whether there still needs to be a divide between the disciplines.

  10. Influence of "Holiday Tourism Circle of Beijing" on Chengde Tourism Spatial Alteration and Reconstruction

    Institute of Scientific and Technical Information of China (English)

    Li Chen; Cheng Shengkui; Chen Yuansheng; Zhang Yingqiu

    2006-01-01

    Chengde City, famous for its cultural sightseeing tourism industry, and is located in China's "Capital Holiday Tourism Circle". This location is advantageous, because of the recent boom in China's national tourism industry. This industry has gone through several structural and development changes with in the past several years. A result of these restructuring patterns is the great changes concerning competitive and cooperative relations among tourism destinations, which have precipitated the decline of the traditional sightseeing pattern.Northern China's "Capital Holiday Tourism Circle" is one of nine key areas within the Chinese tourism industry under development during the Eleventh Five-Year Plan. In the present article the method of "Distance Decline of The Tourist Flow" was used to define the flow of tourists in the Capital Holiday Tourism Circle and its influence upon Chengde's tourism spatial distribution. 3 aspects will be discussed: (1) The transformation from sightseeing to leisure markets makes the change possible in Chengde's tourism spatial pattern. (2) The location advantage (adjacent to Beijing and Tianjin) also leads to the change in Chengde tourism spatial pattern. (3) The establishment of freeways also contributes to a great degrees of change.The rapid development of leisure tourism might lead to the change from nucleus model to a diversified one within Chengde's tourism. Specifically, Chengde is developing the tourism industry with the central heritage area as the nucleus and the northern forest,pasture,southern mountain, and rivers as its periphery.

  11. White Blood Cell Segmentation by Circle Detection Using Electromagnetism-Like Optimization

    Science.gov (United States)

    Oliva, Diego; Díaz, Margarita; Zaldivar, Daniel; Pérez-Cisneros, Marco; Pajares, Gonzalo

    2013-01-01

    Medical imaging is a relevant field of application of image processing algorithms. In particular, the analysis of white blood cell (WBC) images has engaged researchers from fields of medicine and computer vision alike. Since WBCs can be approximated by a quasicircular form, a circular detector algorithm may be successfully applied. This paper presents an algorithm for the automatic detection of white blood cells embedded into complicated and cluttered smear images that considers the complete process as a circle detection problem. The approach is based on a nature-inspired technique called the electromagnetism-like optimization (EMO) algorithm which is a heuristic method that follows electromagnetism principles for solving complex optimization problems. The proposed approach uses an objective function which measures the resemblance of a candidate circle to an actual WBC. Guided by the values of such objective function, the set of encoded candidate circles are evolved by using EMO, so that they can fit into the actual blood cells contained in the edge map of the image. Experimental results from blood cell images with a varying range of complexity are included to validate the efficiency of the proposed technique regarding detection, robustness, and stability. PMID:23476713

  12. White Blood Cell Segmentation by Circle Detection Using Electromagnetism-Like Optimization

    Directory of Open Access Journals (Sweden)

    Erik Cuevas

    2013-01-01

    Full Text Available Medical imaging is a relevant field of application of image processing algorithms. In particular, the analysis of white blood cell (WBC images has engaged researchers from fields of medicine and computer vision alike. Since WBCs can be approximated by a quasicircular form, a circular detector algorithm may be successfully applied. This paper presents an algorithm for the automatic detection of white blood cells embedded into complicated and cluttered smear images that considers the complete process as a circle detection problem. The approach is based on a nature-inspired technique called the electromagnetism-like optimization (EMO algorithm which is a heuristic method that follows electromagnetism principles for solving complex optimization problems. The proposed approach uses an objective function which measures the resemblance of a candidate circle to an actual WBC. Guided by the values of such objective function, the set of encoded candidate circles are evolved by using EMO, so that they can fit into the actual blood cells contained in the edge map of the image. Experimental results from blood cell images with a varying range of complexity are included to validate the efficiency of the proposed technique regarding detection, robustness, and stability.

  13. Concentric circles based simple optical landing aid for vertical takeoff and landing aircrafts

    Science.gov (United States)

    Murshid, Syed H.; Enaya, Rayan; Lovell, Gregory L.

    2014-09-01

    Vertical takeoff and landing (VTOL) aircrafts such as helicopters and drones, add a flexible degree of operation to airborne vehicles. In order to operate these devices in low light situations, where it is difficult to determine slope of the landing surface, a lightweight and standalone device is proposed here. This small optical device can be easily integrated into current VTOL systems. An optical projector consisting of low power, light weight, solid state laser along with minimal optics is utilized to illuminate the landing surface with donut shaped circles and coaxial centralized dot. This device can placed anywhere on the aircraft and a properly placed fiber system can be used to illuminate the surface beneath the bottom of the VTOL aircraft in a fashion that during operation, when the aircraft is parallel to the landing surface, the radius between the central dot and outer ring(s) are equidistant for the entire circumference; however, when there the landing surface of the VTOL aircraft is not parallel to the landing strip, the radial distance between two opposite sides of the circle and central dot will be unequal. The larger this distortion, the greater the difference will be between the opposite sides of the circle. Visual confirmation or other optical devices can be used to determine relative alignment of the projector output allowing the pilot to make proper adjustments as they approach the landing surface to ensure safe landings. Simulated and experimental results from a prototype optical projector are presented here.

  14. Planning Curvature-Constrained Paths to Multiple Goals Using Circle Sampling.

    Science.gov (United States)

    Lobaton, Edgar; Zhang, Jinghe; Patil, Sachin; Alterovitz, Ron

    2011-01-01

    We present a new sampling-based method for planning optimal, collision-free, curvature-constrained paths for nonholonomic robots to visit multiple goals in any order. Rather than sampling configurations as in standard sampling-based planners, we construct a roadmap by sampling circles of constant curvature and then generating feasible transitions between the sampled circles. We provide a closed-form formula for connecting the sampled circles in 2D and generalize the approach to 3D workspaces. We then formulate the multi-goal planning problem as finding a minimum directed Steiner tree over the roadmap. Since optimally solving the multi-goal planning problem requires exponential time, we propose greedy heuristics to efficiently compute a path that visits multiple goals. We apply the planner in the context of medical needle steering where the needle tip must reach multiple goals in soft tissue, a common requirement for clinical procedures such as biopsies, drug delivery, and brachytherapy cancer treatment. We demonstrate that our multi-goal planner significantly decreases tissue that must be cut when compared to sequential execution of single-goal plans.

  15. Adaptive circle-ellipse fitting method for estimating tree diameter based on single terrestrial laser scanning

    Science.gov (United States)

    Bu, Guochao; Wang, Pei

    2016-04-01

    Terrestrial laser scanning (TLS) has been used to extract accurate forest biophysical parameters for inventory purposes. The diameter at breast height (DBH) is a key parameter for individual trees because it has the potential for modeling the height, volume, biomass, and carbon sequestration potential of the tree based on empirical allometric scaling equations. In order to extract the DBH from the single-scan data of TLS automatically and accurately within a certain range, we proposed an adaptive circle-ellipse fitting method based on the point cloud transect. This proposed method can correct the error caused by the simple circle fitting method when a tree is slanted. A slanted tree was detected by the circle-ellipse fitting analysis, then the corresponding slant angle was found based on the ellipse fitting result. With this information, the DBH of the trees could be recalculated based on reslicing the point cloud data at breast height. Artificial stem data simulated by a cylindrical model of leaning trees and the scanning data acquired with the RIEGL VZ-400 were used to test the proposed adaptive fitting method. The results shown that the proposed method can detect the trees and accurately estimate the DBH for leaning trees.

  16. A circle dance in a psychiatric setting : can a circle dance intervention decrease levels of depressed affect among patients with mental health illnesses and, if so, what aspect of this dance is most significant?

    OpenAIRE

    Beard, Ella King

    2016-01-01

    This study investigates the role of the circle dance in decreasing depressed affect amongst a group of 45 patients with severe mental health illnesses and highlights the most significant aspect of that dance. Patients participated in one of four conditions: a group performing a regular traditional upbeat Irish circle dance holding hands and with a jump step [jump+hands]; a group performing the same dance holding hands with no jump step [hands]; a group performing the same dance without holdin...

  17. "Really," "Not Possible," "I Can't Believe It": Exploring Informational Text in Literature Circles

    Science.gov (United States)

    Barone, Diane; Barone, Rebecca

    2016-01-01

    Fifth graders' interpretations of nonfiction or informational text were explored. Each literature circle group read and responded to informational text. Discoveries included that students' conversations and written responses were closely connected to text and that students created multimodal responses.

  18. Ultrasensitive detection of nucleic acids by template enhanced hybridization followed by rolling circle amplification and catalytic hairpin assembly.

    Science.gov (United States)

    Song, Weiling; Zhang, Qiao; Sun, Wenbo

    2015-02-11

    An ultrasensitive protocol for fluorescent detection of DNA is designed by combining the template enhanced hybridization process (TEHP) with Rolling Circle Amplification (RCA) and Catalytic Hairpin Assembly (CHA), showing a remarkable amplification efficiency.

  19. Kobayashi's and Teichmüller's Metrics on the Teichmüller Space of Symmetric Circle Homeomorphisms

    Institute of Scientific and Technical Information of China (English)

    Jun HU; Yun Ping JIANG; Zhe WANG

    2011-01-01

    We give a direct proof of a result of Earle, Gardiner and Lakic, that is, Kobayashi's metric and Teichmüller's metric coincide with each other on the Teichmüller space of symmetric circle homeomorphisms.

  20. Comparison of two different methods for the uncertainty estimation of circle diameter measurements using an optical coordinate measuring machine

    DEFF Research Database (Denmark)

    Morace, Renata Erica; Hansen, Hans Nørgaard; De Chiffre, Leonardo

    2005-01-01

    This paper deals with the uncertainty estimation of measurements performed on optical coordinate measuring machines (CMMs). Two different methods were used to assess the uncertainty of circle diameter measurements using an optical CMM: the sensitivity analysis developing an uncertainty budget...