Geodesy introduction to geodetic datum and geodetic systems
Lu, Zhiping; Qiao, Shubo
2014-01-01
A full introduction to geodetic data and systems written by well-known experts in their respective fields, this book is an ideal text for courses in geodesy and geomatics covering everything from coordinate and gravimetry data to geodetic systems of all types.
On the unification of geodetic leveling datums using satellite altimetry
Mather, R. S.; Rizos, C.; Morrison, T.
1978-01-01
Techniques are described for determining the height of Mean Sea Level (MSL) at coastal sites from satellite altimetry. Such information is of value in the adjustment of continental leveling networks. Numerical results are obtained from the 1977 GEOS-3 altimetry data bank at Goddard Space Flight Center using the Bermuda calibration of the altimeter. Estimates are made of the heights of MSL at the leveling datums for Australia and a hypothetical Galveston datum for central North America. The results obtained are in reasonable agreement with oceanographic estimates obtained by extrapolation. It is concluded that all gravity data in the Australian bank AUSGAD 76 and in the Rapp data file for central North America refer to the GEOS-3 altimeter geoid for 1976.0 with uncertainties which do not exceed + or - 0.1 mGal.
The Impact of Sea Level Rise on Geodetic Vertical Datum of Peninsular Malaysia
Din, A. H. M.; Abazu, I. C.; Pa'suya, M. F.; Omar, K. M.; Hamid, A. I. A.
2016-09-01
Sea level rise is rapidly turning into major issues among our community and all levels of the government are working to develop responses to ensure these matters are given the uttermost attention in all facets of planning. It is more interesting to understand and investigate the present day sea level variation due its potential impact, particularly on our national geodetic vertical datum. To determine present day sea level variation, it is vital to consider both in-situ tide gauge and remote sensing measurements. This study presents an effort to quantify the sea level rise rate and magnitude over Peninsular Malaysia using tide gauge and multi-mission satellite altimeter. The time periods taken for both techniques are 32 years (from 1984 to 2015) for tidal data and 23 years (from 1993 to 2015) for altimetry data. Subsequently, the impact of sea level rise on Peninsular Malaysia Geodetic Vertical Datum (PMGVD) is evaluated in this study. the difference between MSL computed from 10 years (1984 - 1993) and 32 years (1984 - 2015) tidal data at Port Kelang showed that the increment of sea level is about 27mm. The computed magnitude showed an estimate of the long-term effect a change in MSL has on the geodetic vertical datum of Port Kelang tide gauge station. This will help give a new insight on the establishment of national geodetic vertical datum based on mean sea level data. Besides, this information can be used for a wide variety of climatic applications to study environmental issues related to flood and global warming in Malaysia.
THE IMPACT OF SEA LEVEL RISE ON GEODETIC VERTICAL DATUM OF PENINSULAR MALAYSIA
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A. H. M. Din
2016-09-01
Full Text Available Sea level rise is rapidly turning into major issues among our community and all levels of the government are working to develop responses to ensure these matters are given the uttermost attention in all facets of planning. It is more interesting to understand and investigate the present day sea level variation due its potential impact, particularly on our national geodetic vertical datum. To determine present day sea level variation, it is vital to consider both in-situ tide gauge and remote sensing measurements. This study presents an effort to quantify the sea level rise rate and magnitude over Peninsular Malaysia using tide gauge and multi-mission satellite altimeter. The time periods taken for both techniques are 32 years (from 1984 to 2015 for tidal data and 23 years (from 1993 to 2015 for altimetry data. Subsequently, the impact of sea level rise on Peninsular Malaysia Geodetic Vertical Datum (PMGVD is evaluated in this study. the difference between MSL computed from 10 years (1984 – 1993 and 32 years (1984 – 2015 tidal data at Port Kelang showed that the increment of sea level is about 27mm. The computed magnitude showed an estimate of the long-term effect a change in MSL has on the geodetic vertical datum of Port Kelang tide gauge station. This will help give a new insight on the establishment of national geodetic vertical datum based on mean sea level data. Besides, this information can be used for a wide variety of climatic applications to study environmental issues related to flood and global warming in Malaysia.
Filmer, M. S.; Hughes, C. W.; Woodworth, P. L.; Featherstone, W. E.; Bingham, R. J.
2018-04-01
The direct method of vertical datum unification requires estimates of the ocean's mean dynamic topography (MDT) at tide gauges, which can be sourced from either geodetic or oceanographic approaches. To assess the suitability of different types of MDT for this purpose, we evaluate 13 physics-based numerical ocean models and six MDTs computed from observed geodetic and/or ocean data at 32 tide gauges around the Australian coast. We focus on the viability of numerical ocean models for vertical datum unification, classifying the 13 ocean models used as either independent (do not contain assimilated geodetic data) or non-independent (do contain assimilated geodetic data). We find that the independent and non-independent ocean models deliver similar results. Maximum differences among ocean models and geodetic MDTs reach >150 mm at several Australian tide gauges and are considered anomalous at the 99% confidence level. These differences appear to be of geodetic origin, but without additional independent information, or formal error estimates for each model, some of these errors remain inseparable. Our results imply that some ocean models have standard deviations of differences with other MDTs (using geodetic and/or ocean observations) at Australian tide gauges, and with levelling between some Australian tide gauges, of ˜ ± 50 mm . This indicates that they should be considered as an alternative to geodetic MDTs for the direct unification of vertical datums. They can also be used as diagnostics for errors in geodetic MDT in coastal zones, but the inseparability problem remains, where the error cannot be discriminated between the geoid model or altimeter-derived mean sea surface.
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Shengxiang Huang
2017-01-01
Full Text Available A landslide monitoring network construction within unified datum which combined fiducial points, working reference points, and monitoring points was intensively studied in the Three Gorges Reservoir area. With special long and narrow geographical location in the area, designing and building monitoring network was vital to the realization of landslide monitoring. To build such a network with high precision, this paper mainly focused on the following four aspects: (1 method of using multiple GPS reference stations to build a unified datum network and subnet adjustment, (2 GPS data processing algorithm with millimeter level, (3 analysis of influence on the adjustment resulting from systematic error of time evolution datum from different GPS observations, and (4 establishment and stability analysis of unified datum. Then, using global test and trial-and-error method to analyze the datum based on the GPS observations (2008~2011 of landslide monitoring network in the area, we concluded that there were moved reference points during the three years of high water impoundment, and the horizontal displacement of moved reference points was more than 4 cm, even up to 79.4 cm. The displacement direction of unstable reference points was inspected with geographical environment at sites, which revealed congruency between them.
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Mostafa Rabah
2016-06-01
To see how non-performing maintenance degrading the values of the HARN and NACN, the available HARN and NACN stations in the Nile Delta were observed. The Processing of the tested part was done by CSRS-PPP Service based on utilizing Precise Point Positioning “PPP” and Trimble Business Center “TBC”. The study shows the feasibility of Precise Point Positioning in updating the absolute positioning of the HARN network and its role in updating the reference frame (ITRF. The study also confirmed the necessity of the absent role of datum maintenance of Egypt networks.
A Unified Geodetic Vertical Velocity Field (UGVVF), Version 1.0
Schmalzle, G.; Wdowinski, S.
2014-12-01
Tectonic motion, volcanic inflation or deflation, as well as oil, gas and water pumping can induce vertical motion. In southern California these signals are inter-mingled. In tectonics, properly identifying regions that are contaminated by other signals can be important when estimating fault slip rates. Until recently vertical deformation rates determined by high precision Global Positioning Systems (GPS) had large uncertainties compared to horizontal components and were rarely used to constrain tectonic models of fault motion. However, many continuously occupied GPS stations have been operating for ten or more years, often delivering uncertainties of ~1 mm/yr or less, providing better constraints for tectonic modeling. Various processing centers produced GPS time series and estimated vertical velocity fields, each with their own set of processing techniques and assumptions. We compare vertical velocity solutions estimated by seven data processing groups as well as two combined solutions (Figure 1). These groups include: Central Washington University (CWU) and New Mexico Institute of Technology (NMT), and their combined solution provided by the Plate Boundary Observatory (PBO) through the UNAVCO website. Also compared are the Jet Propulsion Laboratory (JPL) and Scripps Orbit and Permanent Array Center (SOPAC) and their combined solution provided as part of the NASA MEaSUREs project. Smaller velocity fields included are from Amos et al., 2014, processed at the Nevada Geodetic Laboratory, Shen et al., 2011, processed by UCLA and called the Crustal Motion Map 4.0 (CMM4) dataset, and a new velocity field provided by the University of Miami (UM). Our analysis includes estimating and correcting for systematic vertical velocity and uncertainty differences between groups. Our final product is a unified velocity field that contains the median values of the adjusted velocity fields and their uncertainties. This product will be periodically updated when new velocity fields
Determination of Vertical Datum Offset between the Regional and the Global Height Datum
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LI Jiancheng
2017-10-01
Full Text Available The unification of the global height datum is a key problem to be solved for geodesy after the unification of global geodetic coordination system and three-dimension spatial datum, and the basis of global spatial information sharing and exchange. In this paper, the theoretical and practical problems of vertical datum offset between the regional height datum and the global height datum are studied. Based on the classical theory of the height system in physical geodesy, the definition of the height datum vertical offset is given, and the rigorous formulas for calculating the vertical offset are derived. The formulas can be used to deduce the three methods of the height datum vertical offset determination. On that basis, the influences of different reference system and reference ellipsoid parameters on the calculation of the vertical offset are analyzed. The results show that the reference system and the ellipsoid parameter conversion are very necessary. At the same time, the height anomaly differences method needs to consider the degree zero correction caused by the inconsistency between gravity potential of the global height datum and the one computed by the model. Based on potential difference approach and the height anomaly difference method, the vertical offset between the China 1985 national height datum and the global height datum corresponding to the normal gravity potential U0 of GRS80, WGS-84 and CGCS2000 reference ellipsoidal from the 152 GPS/leveling points near the origin of Qingdao height origin and the EGM2008, EIGEN-6C4 and SGG-UGM-1 model. The regional datum is 23.1 cm lower than the global datum based on EIGEN-6C4 and WGS-84. When the Gauss-Listing geoid (mean sea surface is selected as the global height datum, the China 1985 national height datum is 21.0 cm higher than the global height datum. The results also show that there are still large differences among the accuracies of the current gravity field models on these GPS
Digital Repository Service at National Institute of Oceanography (India)
Pathak, M.C.; Kotnala, K.L.
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National Oceanic and Atmospheric Administration, Department of Commerce — VDatum is a free software tool being developed jointly by NOAA's National Geodetic Survey (NGS), Office of Coast Survey (OCS), and Center for Operational...
The review and development of a modern GNSS network and datum in Uzbekistan
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Dilbarkhon Fazilova
2017-05-01
Full Text Available This study is focused on the discussion of a modern GNSS network and datum in Uzbekistan. Considering the significance difference (up to 200 m in positions of the local ellipsoidal datum and the global datum, the precise transformation parameters between national geodetic datum CS-42, and the World Geodetic System 1984 (WGS84 global datum used by the GPS is estimated. This study aims to evaluate the accuracy of the currently used transformation parameters from different sources in the region, and give preliminary recommendations for using these sets also. The differences between transformed, original and WGS-84 coordinates were calculated and evaluated. On the basis of this difference, different zones for determination of transformation parameters have been proposed.
Absolute Gravity Datum in the Age of Cold Atom Gravimeters
Childers, V. A.; Eckl, M. C.
2014-12-01
The international gravity datum is defined today by the International Gravity Standardization Net of 1971 (IGSN-71). The data supporting this network was measured in the 1950s and 60s using pendulum and spring-based gravimeter ties (plus some new ballistic absolute meters) to replace the prior protocol of referencing all gravity values to the earlier Potsdam value. Since this time, gravimeter technology has advanced significantly with the development and refinement of the FG-5 (the current standard of the industry) and again with the soon-to-be-available cold atom interferometric absolute gravimeters. This latest development is anticipated to provide improvement in the range of two orders of magnitude as compared to the measurement accuracy of technology utilized to develop ISGN-71. In this presentation, we will explore how the IGSN-71 might best be "modernized" given today's requirements and available instruments and resources. The National Geodetic Survey (NGS), along with other relevant US Government agencies, is concerned about establishing gravity control to establish and maintain high order geodetic networks as part of the nation's essential infrastructure. The need to modernize the nation's geodetic infrastructure was highlighted in "Precise Geodetic Infrastructure, National Requirements for a Shared Resource" National Academy of Science, 2010. The NGS mission, as dictated by Congress, is to establish and maintain the National Spatial Reference System, which includes gravity measurements. Absolute gravimeters measure the total gravity field directly and do not involve ties to other measurements. Periodic "intercomparisons" of multiple absolute gravimeters at reference gravity sites are used to constrain the behavior of the instruments to ensure that each would yield reasonably similar measurements of the same location (i.e. yield a sufficiently consistent datum when measured in disparate locales). New atomic interferometric gravimeters promise a significant
Geodetic Control Points - National Geodetic Survey Benchmarks
NSGIC Local Govt | GIS Inventory — This data contains a set of geodetic control stations maintained by the National Geodetic Survey. Each geodetic control station in this dataset has either a precise...
Rydlund, Jr., Paul H.; Noll, Michael L.
2017-03-07
Datum conversions from the National Geodetic Vertical Datum of 1929 to the North American Vertical Datum of 1988 among inland and coastal gages throughout the hydrologic regions of New England, the Mid-Atlantic, and the South Atlantic-Gulf have implications among river and storm surge forecasting, general commerce, and water-control operations. The process of data conversions may involve the application of a recovered National Geodetic Vertical Datum of 1929–North American Vertical Datum of 1988 offset, a simplistic datum transformation using VDatum or VERTCON software, or a survey, depending on a gaging network datum evaluation, anticipated uncertainties for data use among the cooperative water community, and methods used to derive the conversion. Datum transformations from National Geodetic Vertical Datum of 1929 to North American Vertical Datum of 1988 using VERTCON purport errors of ± 0.13 foot at the 95 percent confidence level among modeled points, claiming more consistency along the east coast. Survey methods involving differential and trigonometric leveling, along with observations using Global Navigation Satellite System technology, afford a variety of approaches to establish or perpetuate a datum during a survey. Uncertainties among leveling approaches are generally quality category and ≥0.1 foot for Level II or III quality categories (defined by the U.S. Geological Survey) by observation and review of experienced practice. The conversion process is initiated with an evaluation of the inland and coastal gage network datum, beginning with altitude datum components and the history of those components queried through the U.S. Geological Survey Groundwater Site Inventory database. Subsequent edits to the Groundwater Site Inventory database may be required and a consensus reached among the U.S. Geological Survey Water Science Centers to identify the outstanding workload categorized as in-office datum transformations or offset applications versus out
2012-07-23
... Datum for Surveying and Mapping Activities for the Territory of Puerto Rico AGENCY: National Geodetic...-16 ( http://www.whitehouse.gov/omb/circulars/a016/a016.html ), to affirm the Puerto Rico Vertical... the islands of Puerto Rico, Culebra, Mona and Vieques of the Commonwealth of Puerto Rico and to the...
Technical Progress and Development Directions of Oceanic Spatial Information Datum
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BAO Jingyang
2017-10-01
Full Text Available This paper briefly analyzes the basic development and technical situation of oceanic spatial information datum, reviews the main processes of oceanic vertical datum and correlative oceanic tidal study, such as improvement and perfect methods of determining tidal station vertical datum, realizing form of vertical datum controlled by tidal station, effect on maintaining vertical datum by long-term tidal station, oceanic tidal model establishing, and also construction and transformation of tidal datum, and then forecasts the key development directions of oceanic spatial information datum on high-accuracy marine position service, vertical datum and the transferring model refinement and spatial datum application.
Integration of space geodesy: a US National Geodetic Observatory
Yunck, Thomas P.; Neilan, Ruth
2003-01-01
In the interest of improving the performance and efficiency of space geodesy a diverse group in the U.S., in collaboration with IGGOS, has begun to establish a unified National Geodetic Observatory (NGO).
El datum geodésico de Ocotepeque y el datum satelitario del sistema WGS84.
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Esteban Dörries
2016-03-01
Full Text Available En Costa Rica están en uso actualmente dos sistemas de coordenadas. El sistema de coordenadas Lambert del Instituto Geográfico Nacional (IGN, definido a partir del datum de Ocotepeque y el sistema CRTM del Catastro Nacional, definido a partir del datum del sistema satelitario GPS. Para establecer las bases científicas y técnicas adecuadas para realizar recomendaciones que permitan fijar normas conducentes a la unificación de los sistemas de referencia y a la eliminación de las ambigüedades, se ejecutó un proyecto de investigación en la Escuela de Topografía, Catastro y Geodesia (ETCG, de la Universidad Nacional, titulado “Estudio comparativo del datum Geodésico de Ocotepeque y el datum satelitario del sistema WGS84”. Este proyecto tuvo como objetivo general efectuar un estudio comparativo de la Red Geodésica Nacional utilizada por el IGN, formada por cadenas de triangulación, es base de la cartografía oficial y está orientada en relación con el datum geodésico de Ocotepeque, y una red obtenida por mediciones GPS constituida por las del Catastro Nacional y de la Universidad Nacional como redes parciales, formada por figuras y orientada en el datum satelitario WGS84.
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Yao Yevenyo Ziggah
2017-03-01
Full Text Available Most developing countries like Ghana are yet to adopt the geocentric datum for its surveying and mapping purposes. It is well known and documented that non-geocentric datums based on its establishment have more distortions in height compared with satellite datums. Most authors have argued that combining such height with horizontal positions (latitude and longitude in the transformation process could introduce unwanted distortions to the network. This is because the local geodetic height in most cases is assumed to be determined to a lower accuracy compared with the horizontal positions. In the light of this, a transformation model was proposed by Featherstone and Vaníček (1999 which avoids the use of height in both global and local datums in coordinate transformation. It was confirmed that adopting such a method reduces the effect of distortions caused by geodetic height on the transformation parameters estimated. Therefore, this paper applied Featherstone and Vaníček (FV model for the first time to a set of common points coordinates in Ghana geodetic reference network. The FV model was used to transform coordinates from global datum (WGS84 to local datum (Accra datum. The results obtained based on the Root Mean Square Error (RMSE and Mean Absolute Error (MAE in both Eastings and Northings were satisfactory. Thus, a RMSE value of 0.66 m and 0.96 m were obtained for the Eastings and Northings while 0.76 m and 0.73 m were the MAE values achieved. Also, the FV model attained a transformation accuracy of 0.49 m. Hence, this study will serve as a preliminary investigation in avoiding the use of height in coordinate transformation within Ghana’s geodetic reference network.
Progress and Prospects in Developing Marine Vertical Datum
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ZHOU Xinghua
2017-10-01
Full Text Available Marine vertical datum system construction is the basic work of marine surveying. In the 2009-2012, China has preliminarily constructed the transformation and unification of different height/depth datum model in the China Sea of 80 nautical mile. In recent years, this model has been extended to the South China Sea, the western Pacific and the eastern Indian Ocean, and then a seamless vertical datum model in the south and north pole area to the whole world gradually will be constructed in the near future, this is the foundation of supporting the digital ocean construction in China. This paper mainly discusses the research status of marine vertical datum construction which had been carried out in major coastal countries or regions, analyzes the main work and approaches and key technologies in the process of the marine vertical datum system building, and then expounds the achievements and existing problems in the practice of our country marine vertical datum building.
Integration of space geodesy: A US National Geodetic Observatory
Yunck, Thomas P.; Neilan, Ruth E.
2005-11-01
In the interest of improving the performance and efficiency of space geodesy a diverse group in the US, in collaboration with IGGOS, has begun to establish a unified National Geodetic Observatory (NGO). To launch this effort an international team will conduct a multi-year program of research into the technical issues of integrating SLR, VLBI, and GPS geodesy to produce a unified set of global geodetic products. The goal is to improve measurement accuracy by up to an order of magnitude while lowering the cost to current sponsors. A secondary goal is to expand and diversify international sponsorship of space geodesy. Principal benefits will be to open new vistas of research in geodynamics and surface change while freeing scarce NASA funds for scientific studies. NGO will proceed in partnership with, and under the auspices of, the International Association of Geodesy (IAG) as an element of the Integrated Global Geodetic Observation System project. The collaboration will be conducted within, and will make full use of, the IAG's existing international services: the IGS, IVS, ILRS, and IERS. Seed funding for organizational activities and technical analysis will come from NASA's Solid Earth and Natural Hazards Program. Additional funds to develop an integrated geodetic data system known as Inter-service Data Integration for Geodetic Operations (INDIGO), will come from a separate NASA program in Earth science information technology. INDIGO will offer ready access to the full variety of NASA's space geodetic data and will extend the GPS Seamless Archive (GSAC) philosophy to all space geodetic data types.
The Unified Levelling Network of Sarawak and its Adjustment
Som, Z. A. M.; Yazid, A. M.; Ming, T. K.; Yazid, N. M.
2016-09-01
The height reference network of Sarawak has seen major improvement in over the past two decades. The most significant improvement was the establishment of extended precise leveling network of which is now able to connect all three major datum points at Pulau Lakei, Original and Bintulu. Datum by following the major accessible routes across Sarawak. This means the leveling network in Sarawak has now been inter-connected and unified. By having such a unified network leads to the possibility of having a common single least squares adjustment been performed for the first time. The least squares adjustment of this unified levelling network was attempted in order to compute the height of all Bench Marks established in the entire levelling network. The adjustment was done by using MoreFix levelling adjustment package developed at FGHT UTM. The computational procedure adopted is linear parametric adjustment by minimum constraint. Since Sarawak has three separate datums therefore three separate adjustments were implemented by utilizing datum at Pulau Lakei, Original Miri and Bintulu Datum respectively. Results of the MoreFix unified adjustment agreed very well with adjustment repeated using Starnet. Further the results were compared with solution given by Jupem and they are in good agreement as well. The difference in height analysed were within 10mm for the case of minimum constraint at Pulau Lakei datum and with much better agreement in the case of Original Miri Datum.
THE UNIFIED LEVELLING NETWORK OF SARAWAK AND ITS ADJUSTMENT
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Z. A. M. Som
2016-09-01
Full Text Available The height reference network of Sarawak has seen major improvement in over the past two decades. The most significant improvement was the establishment of extended precise leveling network of which is now able to connect all three major datum points at Pulau Lakei, Original and Bintulu. Datum by following the major accessible routes across Sarawak. This means the leveling network in Sarawak has now been inter-connected and unified. By having such a unified network leads to the possibility of having a common single least squares adjustment been performed for the first time. The least squares adjustment of this unified levelling network was attempted in order to compute the height of all Bench Marks established in the entire levelling network. The adjustment was done by using MoreFix levelling adjustment package developed at FGHT UTM. The computational procedure adopted is linear parametric adjustment by minimum constraint. Since Sarawak has three separate datums therefore three separate adjustments were implemented by utilizing datum at Pulau Lakei, Original Miri and Bintulu Datum respectively. Results of the MoreFix unified adjustment agreed very well with adjustment repeated using Starnet. Further the results were compared with solution given by Jupem and they are in good agreement as well. The difference in height analysed were within 10mm for the case of minimum constraint at Pulau Lakei datum and with much better agreement in the case of Original Miri Datum.
Ramification of Datum and Ellipsoidal Parameters on Post ...
African Journals Online (AJOL)
Michael
2015-06-01
Jun 1, 2015 ... also post processed using Ghana War Office datum and ellipsoidal parameters. The results for the two ... rely on the datum (Kotzev, 2013). It is equally ..... Microsoft Excel spreadsheet (MS excel) was used for analysis of the ...
Determining Coastal Mean Dynamic Topography by Geodetic Methods
Huang, Jianliang
2017-11-01
In geodesy, coastal mean dynamic topography (MDT) was traditionally determined by spirit leveling technique. Advances in navigation satellite positioning (e.g., GPS) and geoid determination enable space-based leveling with an accuracy of about 3 cm at tide gauges. Recent CryoSat-2, a satellite altimetry mission with synthetic aperture radar (SAR) and SAR interferometric measurements, extends the space-based leveling to the coastal ocean with the same accuracy. However, barriers remain in applying the two space-based geodetic methods for MDT determination over the coastal ocean because current geoid modeling focuses primarily on land as a substitute to spirit leveling to realize the vertical datum.
Global height datum unification: a new approach in gravity potential space
Ardalan, A. A.; Safari, A.
2005-12-01
The problem of “global height datum unification” is solved in the gravity potential space based on: (1) high-resolution local gravity field modeling, (2) geocentric coordinates of the reference benchmark, and (3) a known value of the geoid’s potential. The high-resolution local gravity field model is derived based on a solution of the fixed-free two-boundary-value problem of the Earth’s gravity field using (a) potential difference values (from precise leveling), (b) modulus of the gravity vector (from gravimetry), (c) astronomical longitude and latitude (from geodetic astronomy and/or combination of (GNSS) Global Navigation Satellite System observations with total station measurements), (d) and satellite altimetry. Knowing the height of the reference benchmark in the national height system and its geocentric GNSS coordinates, and using the derived high-resolution local gravity field model, the gravity potential value of the zero point of the height system is computed. The difference between the derived gravity potential value of the zero point of the height system and the geoid’s potential value is computed. This potential difference gives the offset of the zero point of the height system from geoid in the “potential space”, which is transferred into “geometry space” using the transformation formula derived in this paper. The method was applied to the computation of the offset of the zero point of the Iranian height datum from the geoid’s potential value W 0=62636855.8 m2/s2. According to the geometry space computations, the height datum of Iran is 0.09 m below the geoid.
Towards the Implementation of Semi-Dynamic Datum for Malaysia
Shariff, N. S.; Gill, J.; Amin, Z. M.; Omar, K. M.
2017-10-01
A semi-dynamic datum provides positions with respect to time while taking into account the secular and non-secular deformations, making it the best approach to adapt with the dynamic processes of the earth. Malaysia, as yet, employs a static datum, i.e., GDM2000, at epoch 2000; though Malaysia has evidently been affected by seismic activity for the past decade. Therefore, this paper seeks to propose a design for implementing a semi-dynamic datum for Malaysia. Methodologically, GPS time series analyses are carried out to investigate the seismic activity of Malaysia, which essentially contributes to the proposed design of the semi-dynamic datum for Malaysia. The implications of implementing a semi-dynamic datum for Malaysia are discussed as well. The results indicate that Malaysia undergoes a complex deformation; whereby the earthquakes - primarily the 2004 Sumatra-Andaman, 2005 Nias and 2012 Northern Sumatra earthquakes - have affected the underlying secular velocities of Malaysia. Consequently, from this information, the proposed design, particularly the secular and non-secular deformation models, is described in detail. The proposed semi-dynamic datum comprises a transformation, temporal, and spatial module, and utilizes a bilinear interpolation method. Overall, this paper aims to contribute to the feasibility of a semi-dynamic datum approach for Malaysia.
Geodetic Survey Water Level Observations
National Oceanic and Atmospheric Administration, Department of Commerce — Over one million images of National Coast & Geodetic Survey (now NOAA's National Geodetic Survey/NGS) forms captured from microfiche. Tabular forms and charts...
Alvarez, Gabriel O.
2018-05-01
Hydrocarbon exploration in Argentina started long before the IGM created a single, high-precision geodetic reference network for the whole country. Several geodetic surveys were conducted in every producing basin, which have ever since then supported well placement. Currently, every basin has a huge amount of information referenced to the so-called "local" geodetic systems, such as Chos Malal - Quiñi Huao in the Neuquén Basin, and Pampa del Castillo in the San Jorge Basin, which differ to a greater or lesser extent from the national Campo Inchauspe datum established by the IGM in 1969 as the official geodetic network. However, technology development over the last few years and the expansion of satellite positioning systems such as GPS resulted in a new world geodetic order. Argentina rapidly joined this new geodetic order through the implementation of a new national geodetic system by the IGM: POSGAR network, which replaced the old national Campo Inchauspe system. However, this only helped to worsen the data georeferencing issue for oil companies, as a third reference system was added to each basin. Now every basin has a local system, the national system until 1997 (Campo Inchauspe), and finally the newly created POSGAR network national satellite system, which is geocentric unlike the former two planimetric datums. The purpose of this paper is to identify and allocate geodetic systems of coordinates to historical wells, whose geodetic system is missing or has been erroneously allocated, by using currently available technological resources such as geographic information systems and high-resolution satellite imagery.
Modified geodetic brane cosmology
International Nuclear Information System (INIS)
Cordero, Rubén; Cruz, Miguel; Molgado, Alberto; Rojas, Efraín
2012-01-01
We explore the cosmological implications provided by the geodetic brane gravity action corrected by an extrinsic curvature brane term, describing a codimension-1 brane embedded in a 5D fixed Minkowski spacetime. In the geodetic brane gravity action, we accommodate the correction term through a linear term in the extrinsic curvature swept out by the brane. We study the resulting geodetic-type equation of motion. Within a Friedmann–Robertson–Walker metric, we obtain a generalized Friedmann equation describing the associated cosmological evolution. We observe that, when the radiation-like energy contribution from the extra dimension is vanishing, this effective model leads to a self-(non-self)-accelerated expansion of the brane-like universe in dependence on the nature of the concomitant parameter β associated with the correction, which resembles an analogous behaviour in the DGP brane cosmology. Several possibilities in the description for the cosmic evolution of this model are embodied and characterized by the involved density parameters related in turn to the cosmological constant, the geometry characterizing the model, the introduced β parameter as well as the dark-like energy and the matter content on the brane. (paper)
Enhanced definition and required examples of common datum imposed by ISO standard
Yan, Yiqing; Bohn, Martin
2017-12-01
According to the ISO Geometrical Product Specifications (GPS), the establishment and definition of common datum for geometrical components are not fully defined. There are two main limitations of this standard. Firstly: the explications of ISO examples of common datums are not matched with their corresponding definitions, and secondly: a full definition of common datum is missing. This paper suggests a new approach for an enhanced definition and concrete examples of common datum and proposes a holistic methodology for establishment of common datum for each geometrical component. This research is based on the analysis of physical behaviour of geometrical components, orientation constraints and invariance classes of datums. This approach fills the definition gaps of common datum based on ISO GPS, thereby eliminating those deficits. As a result, an improved methodology for a fully functional defined definition of common datum was formulated.
Kravos, Urban
2011-01-01
In the modern business world, communication are becoming more and more complex. As a solution to this problem unified communications occurred. Using a single communication approach unified communications are the integration of various communication technologies (eg, telephony, unified messaging, audio, video and web conferencing and collaboration tools). Unified Messaging, which represents only part of the unified communications means the integration of different non real time communication t...
Unified height systems after GOCE
Rummel, Reiner; Gruber, Thomas; Sideris, Michael; Rangelova, Elena; Woodworth, Phil; Hughes, Chris; Ihde, Johannes; Liebsch, Gunter; Rülke, Axel; Gerlach, Christian; Haagmans, Roger
2015-04-01
The objectives of global height unification are twofold, (1) the realization of accurate geopotential numbers C together with their standard deviation σ(C) at a selected set of stations (datum points of national height systems, geodetic fundamental stations (IERS), primary tide gauges (PSMSL) and primary reference clocks (IERS)) and (2) the determination of height off-sets between all existing regional/national height systems and one global height reference. In the future the primary method of height determination will be GPS-levelling with very stringent requirements concerning the consistency of the positioning and the gravity potential difference part. Consistency is required in terms of the applied standards (ITRF, zero tide system, geodetic reference system). Geopotential differences will be based on a next generation geopotential model combining GOCE and GRACE and a best possible collection of global terrestrial and altimetric gravity and topographic data. Ultimately, the envisaged accuracy of height unification is about 10 cm2/s2 (or 1cm). At the moment, in well surveyed regions, an accuracy of about 40 to 60 cm2/s2 (or 4 to 6cm) is attainable. Objective One can be realized by straight forward computation of geopotential numbers C, i.e. geopotential differences relative to an adopted height reference. No adjustment is required for this. Objective Two, the unification of existing height systems is achieved by employing a least-squares adjustment based on the GBVP-approach. In order to attain a non-singular solution, this requires for each included datum zone at least one geo-referenced station per zone, i.e. its ellipsoidal height h and, in addition, the corresponding physical height H (geopotential number, normal height, orthometric height, etc.). Changes in geopotential numbers of consecutive realizations reflect (1) temporal changes of station heights, (2) improvements or changes of the applied geopotential (or geoid) model and (3) improvements of the
Earth Data Analysis Center, University of New Mexico — This data contains a set of geodetic control stations maintained by the National Geodetic Survey. Each geodetic control station in this dataset has either a precise...
National Geodetic Control Stations, Geographic NAD83, NGS (2004) [geodetic_ctrl_point_la_NGS_2004
Louisiana Geographic Information Center — This data contains a set of geodetic control stations maintained by the National Geodetic Survey. Each geodetic control station in this dataset has either a precise...
Fitting the datum of SANS with Pxy program
International Nuclear Information System (INIS)
Sun, Liangwei; Peng, Mei; Chen, Liang
2009-04-01
The thesis introduces the basic theory of Small-Angle neutron scattering, enumerates several approximate law. It simply describes the components of Small-Angle neutron spectrometer (SANS) and the parameters of SANS of Budapest Neutron Center (BNC) in Hungary. During the period of studying at Budapest Neutron Center in Hungary, the experiments of wavelength calibration was carried out with SIBE and the SANS experiments of sample Micelles. The experiments are briefly introduced. Pxy program is used to fit these datum, and the results of wavelength and sizes of sample Micelles are presented. (authors)
National Geodetic Survey's Airport Aerial Photography
National Oceanic and Atmospheric Administration, Department of Commerce — The National Geodetic Survey (NGS), formerly part of the U.S. Coast and Geodetic Survey, has been performing Aeronautical surveys since the 1920's. NGS, in...
33 CFR 110.129a - Apra Harbor, Guam. (Datum: WGS 84)
2010-07-01
... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Apra Harbor, Guam. (Datum: WGS 84) 110.129a Section 110.129a Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.129a Apra Harbor, Guam. (Datum: WGS 84) (a...
33 CFR 110.168 - Hampton Roads, Virginia and adjacent waters (Datum: NAD 83).
2010-07-01
... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Hampton Roads, Virginia and adjacent waters (Datum: NAD 83). 110.168 Section 110.168 Navigation and Navigable Waters COAST GUARD..., Virginia and adjacent waters (Datum: NAD 83). (a) Anchorage Grounds—(1) Anchorage A [Naval Anchorage]. The...
33 CFR 110.235 - Pacific Ocean (Mamala Bay), Honolulu Harbor, Hawaii (Datum: NAD 83).
2010-07-01
... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Pacific Ocean (Mamala Bay), Honolulu Harbor, Hawaii (Datum: NAD 83). 110.235 Section 110.235 Navigation and Navigable Waters COAST... Pacific Ocean (Mamala Bay), Honolulu Harbor, Hawaii (Datum: NAD 83). (a) The anchorage grounds—(1...
Datum Feature Extraction and Deformation Analysis Method Based on Normal Vector of Point Cloud
Sun, W.; Wang, J.; Jin, F.; Liang, Z.; Yang, Y.
2018-04-01
In order to solve the problem lacking applicable analysis method in the application of three-dimensional laser scanning technology to the field of deformation monitoring, an efficient method extracting datum feature and analysing deformation based on normal vector of point cloud was proposed. Firstly, the kd-tree is used to establish the topological relation. Datum points are detected by tracking the normal vector of point cloud determined by the normal vector of local planar. Then, the cubic B-spline curve fitting is performed on the datum points. Finally, datum elevation and the inclination angle of the radial point are calculated according to the fitted curve and then the deformation information was analyzed. The proposed approach was verified on real large-scale tank data set captured with terrestrial laser scanner in a chemical plant. The results show that the method could obtain the entire information of the monitor object quickly and comprehensively, and reflect accurately the datum feature deformation.
National Oceanic and Atmospheric Administration, Department of Commerce — This data contains a set of geodetic control stations maintained by the National Geodetic Survey. Each geodetic control station in this dataset has either a precise...
Comparing The Accuracy of Different Map Projections and Datums Using Truth Data
Directory of Open Access Journals (Sweden)
Amjed Naser Mohsin AL-Hameedawi
2018-02-01
Full Text Available Positional inaccuracy is a major public engineering problem, and the cause of errors which lead to inaccurate measurements. The main challenge faced by many researchers is the accuracy. Hence, this paper involved comparing various map projections and datums effect on accuracy using 7 parameter method and root mean square errors (RMSE test. In order to prepare data for analysis, sets of points in the study area, which is located in north of Iraq in Sulaymaniyah Governorate (Arbat City, were selected as follows: first set of ten checkpoints (reference points was selected randomly. The cartographic parameters for these points were (Lat. /Long. coordinates and datum was WGS84 using Differential GPS. Then other sets of points were ten Ground Control Points (GCP for the same positions, but in this case were Cartesian coordinates with different projections and datums. The idea was to convert coordinates system of the second set points to geographic coordinate system for all specified projections using 7 parameter method. After that calculate RMSE between transformed coordinates and original coordinates (first set of checkpoints. The projection and datum that will guarantee less RMSE will be the best for study area. In this method required acquire ground control points (GCP and global position system points (GPS points, for the purpose completing the study all the needed coordinates were measured using DGPS. Not only datum transformation from global datum (WGS1984-UTM-Zone-38N to local datum (Karbala1979-UTM-Zone-38N were performed, but also producing new maps for the purpose of comparisons. The results demonstrated that UTM projection and local datum (Karbala1979-UTM-Zone-38N were the best for study area according to RMSE test.
DEFF Research Database (Denmark)
Torgersen, Mads
This thesis presents the RUNE language, a semantic construction of related and tightly coupled programming constructs presented in the shape of a programming language. The major contribution is the succesfull design of a highly unified and general programming model, capable of expressing some of ...... a unified name declaration mechanism. The resulting expressiveness allows for argument covariance, dependent types and module types, plus a solution to the so-called expression problem of two way extensibility in object-oriented languages....... of the most complex type relations put forth in type systems research, without compromising such fundamental qualities as conceptuality, modularity and static typing. While many new constructs and unifications are put forth to substantiate their conceptual validity, type rules are given to support...
International Nuclear Information System (INIS)
Georgi, H.
1980-01-01
Unified gauge theories such as SU(5) of particle interactions are built on the colour SU(3) and SU(2) x U(1) gauge theories which apparently describe strong and weak and electromagnetic interactions at distances as small as 10 -16 cm. In this article the classical reasons for going beyond SU(3)xSU(2)xU(1) to a fully unified theory such as SU(5) are reviewed, and a new reason formulated. A class of imaginary worlds similar to our own is considered and it is shown that unification is possible only in ours. This suggests that the low-energy interactions are unique in that they are constructed to make unification possible. (author)
Legacy and future of Kilauea's geodetic studies
Montgomery-Brown, E. D.; Miklius, A.
2011-12-01
Because of its extensive and detailed history of geodetic measurements, Kilauea is one of the best-studied if not also best-understood volcanic systems in the world. Hawaiian volcanoes have a long history of deformation observations. These observations range from native legends of Pele's underground travels, through initial measurements made by the Hawaiian Volcano Observatory, and finally to current ground-based and satellite observations. Many questions still remain, relating to Kilauea's dynamics, where geodetic measurements could offer fundamental insights. For example, new geodetic experiments could lead to a better understanding of the degree of magmatic and tectonic interaction, the geometries of faults at depth, the extent of offshore deformation, and the magmatic plumbing system. While it is possible to design many experiments to address these issues, we focus on three deformation targets where geodetic improvements, including finer sampling in space and time, could yield significant advancements toward understanding Kilauea's dynamics. First, by scrutinizing spatially-dense space-borne geodetic data for signs of upper east rift zone deformation and incorporating gravity and seismic data in a high resolution tomographic model, the hydraulic connection between Kilauea's summit and the rift zone could be imaged, which would provide insight into the pathways that transport magma out to the rift zones. Second, a combination of geodetic and seismic data could be used to determine the nature of possible relationships and interactions between the Hilina fault system and Kilauea's basal decollement. Such a study would have important implications for assessments of future earthquake and sector collapse hazards. Lastly, by adding seafloor geodetic measurements and seismic data to the current geodetic network on Kilauea, we could delimit the offshore extent of transient and episodic decollement deformation. In addition to multidisciplinary approaches, future geodetic
Stability of Global Geodetic Results
Herring, T.
The precision of global geodetic techniques has reached unprecedented levels. Sys- tems capable of millimeter level horizontal and several millimeter vertical precisions are now deployed. The Global Positioning System (GPS) has the most deployed continuously-operating receivers with several hundred providing data through the in- ternet for analysis. However, the satellite system used with GPS evolves with time as new generations of GPS satellites are launched. During the 1990's, the constellation evolved from Block I to Block II and IIA with the most recent generation being Block IIR. There are considerable differences in the size and antenna configurations in the different generations of satellites. The antenna configuration specifically could cause systematic changes in the terrestrial reference system. Results from the ITRF2000 combinations suggest that there are significant time variations in the scale of GPS system possibly due to phase center variations in GPS transmission antennas. These variations could result in height changes of up to 3 mm/yr. We will investigate the stability of the GPS system through combination of GPS results with results from VLBI and SLR. All components of the transformation between the systems, rotation, translation and scale will be investigated.
Evaluation of datum unit for diagnostics of journal-bearing systems
International Nuclear Information System (INIS)
Jeon, Byung Chul; Jung, Joon Ha; Youn, Byeng Doog; Kim, Yeon Whan; Bae, Yong Chae
2015-01-01
Journal bearings support rotors using fluid film between the rotor and the stator. Generally, journal bearings are used in large rotor systems such as turbines in a power plant, because even in high-speed and load conditions, journal bearing systems run in a stable condition. To enhance the reliability of journal-bearing systems, in this paper, we study health-diagnosis algorithms that are based on the supervised learning method. Specifically, this paper focused on defining the unit of features, while other previous papers have focused on defining various features of vibration signals. We evaluate the features of various lengths or units on the separable ability basis. From our results, we find that one cycle datum in the time-domain and 60 cycle datum in the frequency domain are the optimal datum units for real-time journal-bearing diagnosis systems
Evaluation of datum unit for diagnostics of journal-bearing systems
Energy Technology Data Exchange (ETDEWEB)
Jeon, Byung Chul; Jung, Joon Ha; Youn, Byeng Doog [Dept. of Mechanical and Aerospace Engineering, Seoul National University, Seoul (Korea, Republic of); Kim, Yeon Whan; Bae, Yong Chae [Power Generation Laboratory, KEPCO Research Institute, Daejeon (Korea, Republic of)
2015-08-15
Journal bearings support rotors using fluid film between the rotor and the stator. Generally, journal bearings are used in large rotor systems such as turbines in a power plant, because even in high-speed and load conditions, journal bearing systems run in a stable condition. To enhance the reliability of journal-bearing systems, in this paper, we study health-diagnosis algorithms that are based on the supervised learning method. Specifically, this paper focused on defining the unit of features, while other previous papers have focused on defining various features of vibration signals. We evaluate the features of various lengths or units on the separable ability basis. From our results, we find that one cycle datum in the time-domain and 60 cycle datum in the frequency domain are the optimal datum units for real-time journal-bearing diagnosis systems.
VARIATION OF CHART DATUM TOWARDS MARITIME DELIMITATION DUE TO RISING SEA LEVEL
Directory of Open Access Journals (Sweden)
A. R. M. Faizuddin
2017-10-01
Full Text Available The importance of Chart Datum in hydrographic surveying is inarguable because its determination is part of the process to obtain the actual depth of bathymetry. The Chart Datum has a relationship with the determination of base points because any uncertainty of the base points would definitely cause uncertainty to the determination of the maritime baseline. If there is any doubt on the baselines, it will then cause doubt on the maritime zones as well which includes the equidistant line that forms the border between the two countries. However, due to the ongoing rising sea level, there has been some variations of the Chart Datum in some areas in Malaysia. This research discusses about the variation of Mean Sea Level and Chart Datum for the tide gauge stations at Geting, Cendering, Sedili and Tioman at East Coast and Kukup, Langkawi, Lumut and Penang at the West Coast of Peninsular Malaysia. The tidal analysis was carried out by using the 23 years of data beginning at 1993 to 2015. The observed tidal data for 23 years were processed and analysed by using GeoTide software. In this research, the Harmonic Analysis technique was used in order to calculate the values of Mean Sea Level and the Chart Datum while the slope of the shoreline is modelled by using Global Mapper. The linear trend of the Mean Sea Level and the Chart Datum was analysed to determine the increase of the annual sea level in millimetres accuracy and also to determine the variation of the Chart Datum for each tidal station and its impact towards maritime baseline. The result has shown that the linear trend of sea level rise varies from 24 millimetres per year up to 168 millimetres per year at the East Coast and 24 millimetres per year up to 96 millimetres per year at the West Coast of Peninsular Malaysia. As for the maritime baseline, results has indicated that there exist shifting in the horizontal which are varies from 1.564 metres per year to 3.299 metres per year at the East Coast
Variation of Chart Datum Towards Maritime Delimitation due to Rising Sea Level
Faizuddin, A. R. M.; Razali, M. M.
2017-10-01
The importance of Chart Datum in hydrographic surveying is inarguable because its determination is part of the process to obtain the actual depth of bathymetry. The Chart Datum has a relationship with the determination of base points because any uncertainty of the base points would definitely cause uncertainty to the determination of the maritime baseline. If there is any doubt on the baselines, it will then cause doubt on the maritime zones as well which includes the equidistant line that forms the border between the two countries. However, due to the ongoing rising sea level, there has been some variations of the Chart Datum in some areas in Malaysia. This research discusses about the variation of Mean Sea Level and Chart Datum for the tide gauge stations at Geting, Cendering, Sedili and Tioman at East Coast and Kukup, Langkawi, Lumut and Penang at the West Coast of Peninsular Malaysia. The tidal analysis was carried out by using the 23 years of data beginning at 1993 to 2015. The observed tidal data for 23 years were processed and analysed by using GeoTide software. In this research, the Harmonic Analysis technique was used in order to calculate the values of Mean Sea Level and the Chart Datum while the slope of the shoreline is modelled by using Global Mapper. The linear trend of the Mean Sea Level and the Chart Datum was analysed to determine the increase of the annual sea level in millimetres accuracy and also to determine the variation of the Chart Datum for each tidal station and its impact towards maritime baseline. The result has shown that the linear trend of sea level rise varies from 24 millimetres per year up to 168 millimetres per year at the East Coast and 24 millimetres per year up to 96 millimetres per year at the West Coast of Peninsular Malaysia. As for the maritime baseline, results has indicated that there exist shifting in the horizontal which are varies from 1.564 metres per year to 3.299 metres per year at the East Coast and from 1
2013-06-18
... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management [MMAA104000] North American Datum of 1983 (NAD 83) Outer Continental Shelf (OCS) Provisional Official Protraction Diagram (OPDs) AGENCY... OPDs. SUMMARY: Notice is hereby given that effective with this publication two NAD 83-based OCS...
A global vertical reference frame based on four regional vertical datums
Czech Academy of Sciences Publication Activity Database
Burša, Milan; Kenyon, S.; Kouba, J.; Šíma, Zdislav; Vatrt, V.; Vojtíšková, M.
2004-01-01
Roč. 48, č. 3 (2004), s. 493-502 ISSN 0039-3169 Institutional research plan: CEZ:AV0Z1003909 Keywords : geopotentinal * local vertical datums * global vertical reference frame Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 0.447, year: 2004
2011-12-12
... Datum for Surveying and Mapping Activities for the Islands of St. Croix, St. John, and St. Thomas... datum for surveying and mapping activities for the islands of St. Croix, St. John, and St. Thomas of the... by other Federal surveying and mapping agencies on St. Croix, St. John, and St. Thomas, with the...
Goradia, Shantilal
2013-04-01
Century old GR fails to unify quantum physics, nuclear force or distinguish between the mass of living bodies from inert mass. Probabilistic gravity [1] explains strong coupling (nuclear force). The natural log of the age of the universe, 10E60 in Planck times, equaling 137 (1/Alpha) extends physics to deeper science, if we stand on the shoulders of giants like Feynman and Gamow. Implications of [1] are that it is not the earth, but M and S numbers of the particles of the earth are remotely interacting with corresponding numbers of the particles of the moon and the sun respectively, neglecting other heavenly bodies in this short draft. This new physics is likely to enable creative scientific minds to throw light on a theoretical basis for an otherwise arbitrary cosmological constant, uniformity of microwave background, further vindication of Boltzmann, quantum informatics, Einstein’s later publicized views and more, eliminating the need to spend money for implicitly nonexistent quantum gravity and graviton.[4pt] [1] Journal of Physical Science and Applications 2 (7) (2012) 265-268.
Explicitly computing geodetic coordinates from Cartesian coordinates
Zeng, Huaien
2013-04-01
This paper presents a new form of quartic equation based on Lagrange's extremum law and a Groebner basis under the constraint that the geodetic height is the shortest distance between a given point and the reference ellipsoid. A very explicit and concise formulae of the quartic equation by Ferrari's line is found, which avoids the need of a good starting guess for iterative methods. A new explicit algorithm is then proposed to compute geodetic coordinates from Cartesian coordinates. The convergence region of the algorithm is investigated and the corresponding correct solution is given. Lastly, the algorithm is validated with numerical experiments.
Rydlund, Jr., Paul H.; Densmore, Brenda K.
2012-01-01
Geodetic surveys have evolved through the years to the use of survey-grade (centimeter level) global positioning to perpetuate and post-process vertical datum. The U.S. Geological Survey (USGS) uses Global Navigation Satellite Systems (GNSS) technology to monitor natural hazards, ensure geospatial control for climate and land use change, and gather data necessary for investigative studies related to water, the environment, energy, and ecosystems. Vertical datum is fundamental to a variety of these integrated earth sciences. Essentially GNSS surveys provide a three-dimensional position x, y, and z as a function of the North American Datum of 1983 ellipsoid and the most current hybrid geoid model. A GNSS survey may be approached with post-processed positioning for static observations related to a single point or network, or involve real-time corrections to provide positioning "on-the-fly." Field equipment required to facilitate GNSS surveys range from a single receiver, with a power source for static positioning, to an additional receiver or network communicated by radio or cellular for real-time positioning. A real-time approach in its most common form may be described as a roving receiver augmented by a single-base station receiver, known as a single-base real-time (RT) survey. More efficient real-time methods involving a Real-Time Network (RTN) permit the use of only one roving receiver that is augmented to a network of fixed receivers commonly known as Continually Operating Reference Stations (CORS). A post-processed approach in its most common form involves static data collection at a single point. Data are most commonly post-processed through a universally accepted utility maintained by the National Geodetic Survey (NGS), known as the Online Position User Service (OPUS). More complex post-processed methods involve static observations among a network of additional receivers collecting static data at known benchmarks. Both classifications provide users
Establishment of 2000 National Geodetic Control Network of China and It’s Technological Progress
Directory of Open Access Journals (Sweden)
CHEN Junyong
2007-02-01
Full Text Available Objectives: 2000’ National Geodetic Control Network of China is an important fundamental scientific engineering project in China. It consists of three parts which are establishment of 2000 National GPS Geodetic Network, its combination adjustment with national astro-geodetic network and 2000 National Gravity Fundamental network. It provides the high precise coordinate reference and gravity reference for three dimensional geo-center national coordinates system and gravity system, respectively. Additionally, it provides precise unified geometric and physical geodesy information for the economic construction, the national defense and the scientific research. Methods: 1. The larger number of data are processed in triple networks adjustment of 2000 National GPS Geodetic Network, which are chosen from the GPS monitoring stations, such as grade A, B of national GPS network , grade 1st and 2nd of national GPS network, crustal movement observation network of China, and others crustal deformation monitoring stations. Finally, the data of 2666 GPS stations are used in the data processing of 2000 National GPS Geodetic Network, including 124 external stations and 2542 internal stations. In order to the results of triple networks adjustment are corresponding to that of three dimensional geo-center coordinates system, ITRF 97 and epoch 2000.0 are chosen as the coordinate reference frame and epoch reference, respectively. The methods of “strong reference” and “weak reference” are combined used in the control data selection of triple networks adjustment. The scale and rotation scales are adopted for each sub network. The least square adjustment is firstly adopted in each sub network adjustment. The data of obvious abnormal baselines are found and rejected firstly. And the method of double factor robust estimation is adopted in the data processing. 2. The combined adjustment of 2000 National GPS Geodetic Network and national astro-geodetic network is
Geodetic alignment of laser power installations
International Nuclear Information System (INIS)
Shtorm, V.V.; Gostev, A.M.; Drobikov, A.V.
1989-01-01
Main problems occuring in applied geodesy under initial alignment of laser power installation optical channel are considered. Attention is paid to alignment of lens beamguide telescopic pairs and alignment quality control. Methods and means of geodetic measurements under alignment are indicated. Conclusions are made about the degree of working through certain aspects of the problem
WAVE EQUATION DATUMING TO CORRECT TOPOGRAPHY EFFECT ON FOOTHILL SEISMIC DATA
Directory of Open Access Journals (Sweden)
Montes Vides Luis Alfredo
2005-08-01
Full Text Available The current seismic processing applies Static Corrections to overcome the effects associated to rough topography, based in the assumption that velocity in near surface is lower than in the substratum, which force going up rays travel near to vertical. However, when the velocity contrast between these layers is not large enough, the trajectory of the up going rays deviate from vertical raveling the reflectors erroneously. A better alternative to correct this is to continue the wave field to a datum, because it does not assume vertical ray trajectory and solves the acoustic wave equation to extrapolate sources and receivers. The Kirchhoff approach was tested in synthetic shots continuing their wave field to a datum and finally it was applied instead of Static Corrections in real data acquired in foothill zones. First shot and receiver gathers were downward continued to the base of weathering layer and later upward continued to a final flat datum. Comparing the obtained results we observed that continuation approach provides a noticeable enhancement of reflectors in seismic records, displaying a better continuity of the reflectors and an increment in frequency content.
Geodetic precession or dragging of inertial frames?
International Nuclear Information System (INIS)
Ashby, N.; Shahid-Saless, B.
1990-01-01
In metric theories of gravity the principle of general covariance allows one to describe phenomena by means of any convenient choice of coordinate system. In this paper it is shown that in an appropriately chosen coordinate system, geodetic precession of a gyroscope orbiting a spherically symmetric, spinning mass can be recast as a Lense-Thirring frame-dragging effect without invoking spatial curvature. The origin of this reference frame moves around the source but the frame axes point in fixed directions. The drag can be interpreted to arise from the orbital angular momentum of the source around the origin of the reference frame. In this reference frame the effects of geodetic precession and Lense-Thirring drag due to intrinsic angular momentum of the source have the same origin, namely, gravitomagnetism
3D geodetic monitoring slope deformations
Directory of Open Access Journals (Sweden)
Weiss Gabriel
1996-06-01
Full Text Available For plenty of slope failures that can be found in Slovakia is necessary and very important their geodetic monitoring (because of their activity, reactivisations, checks. The paper gives new methodologies for these works, using 3D terrestrial survey technologies for measurements in convenient deformation networks. The design of an optimal type of deformation model for various kinds of landslides and their exact processing with an efficient testing procedure to determine the kinematics of the slope deformations are presented too.
Healy, Paul; Barber, Declan
2015-01-01
As telephony services, mobile services and internet services continue to converge, the prospect of providing Unified Messaging and even Unified Communications becomes increasingly achievable. This paper discusses the growing importance of IP-based networks to Unified Messaging developments and examines some of the key services and protocols that are likely to make Unified Messaging more widely available. In this initial paper, we limit ourselves initially to the unification of text-based mess...
Search skip specific nav links Home arrow Unified Federal Review Three logos: 1) Executive Office of the Homeland Security. Unified Federal Environmental and Historic Preservation Review Process Please visit the new location for the Unified Federal Review located here: http://www.fema.gov/environmental-historic
Ostrogradski Hamiltonian approach for geodetic brane gravity
International Nuclear Information System (INIS)
Cordero, Ruben; Molgado, Alberto; Rojas, Efrain
2010-01-01
We present an alternative Hamiltonian description of a branelike universe immersed in a flat background spacetime. This model is named geodetic brane gravity. We set up the Regge-Teitelboim model to describe our Universe where such field theory is originally thought as a second order derivative theory. We refer to an Ostrogradski Hamiltonian formalism to prepare the system to its quantization. This approach comprize the manage of both first- and second-class constraints and the counting of degrees of freedom follows accordingly.
Geodetic achievement and avoidance games for graphs | Haynes ...
African Journals Online (AJOL)
Let G = (V,E) be a nontrivial connected graph. For a subset S ⊆ V, the geodesic closure (S) of S is the set of all vertices on geodesics (shortest paths) between two vertices of S. We study the geodetic achievement and avoidance games defined by Buckley and Harary (Geodetic games for graphs, Quaestiones Math.
Directory of Open Access Journals (Sweden)
Sun Shaoan
2011-11-01
Full Text Available A statistical correlation method is used to study the effect of instability of the calculation datum (used in traditional method of indirect adjustment on calculated gravity results, using data recorded by Long-men Mountain regional gravity network during 1996 – 2007. The result shows that when this effect is corrected, anomalous gravity changes before the 2008 Wenchuan Ms8.0 earthquake become obvious and characteristically distinctive. Thus the datum-stability problem must be considered when processing and analyzing data recorded by a regional gravity network.
Multi-geodetic characterization of the seasonal signal at the CERGA geodetic reference, France
Memin, A.; Viswanathan, V.; Fienga, A.; Santamaría-Gómez, A.; Boy, J. P.
2016-12-01
Crustal deformations due to surface-mass loading account for a significant part of the variability in geodetic time series. A perfect understanding of the loading signal observed by geodetic techniques should help in improving terrestrial reference frame (TRF) realizations. Yet, discrepancies between crustal motion estimates from models of surface-mass loading and observations are still too large so that no model is currently recommended by the IERS for reducing the data. We investigate the discrepancy observed in the seasonal variations of the CERGA station, South of France.We characterize the seasonal motions of the reference geodetic station CERGA from GNSS, SLR and LLR. We compare the station motion observed with GNSS and SLR and we estimate changes in the station-to-the-moon distance using an improved processing strategy. We investigate the consistency between these geodetic techniques and compare the observed station motion with that estimated using models of surface-mass change. In that regard, we compute atmospheric loading effects using surface pressure fields from ECMWF, assuming an ocean response according to the classical inverted barometer (IB) assumption, considered to be valid for periods typically exceeding a week. We also used general circulation ocean models (ECCO and GLORYS) forced by wind, heat and fresh water fluxes. The continental water storage is described using GLDAS/Noah and MERRA-land models.Using the surface-mass models, we estimate the amplitude of the seasonal vertical motion of the CERGA station ranging between 5 and 10 mm with a maximum reached in August, mostly due to hydrology. The horizontal seasonal motion of the station may reach up to 3 mm. Such a station motion should induce a change in the distance to the moon reaching up to 10 mm, large enough to be detected in LLR time series and compared to GNSS- and SLR-derived motion.
Introducing a New Software for Geodetic Analysis
Hjelle, Geir Arne; Dähnn, Michael; Fausk, Ingrid; Kirkvik, Ann-Silje; Mysen, Eirik
2017-04-01
At the Norwegian Mapping Authority, we are currently developing Where, a new software for geodetic analysis. Where is built on our experiences with the Geosat software, and will be able to analyse and combine data from VLBI, SLR, GNSS and DORIS. The software is mainly written in Python which has proved very fruitful. The code is quick to write and the architecture is easily extendable and maintainable, while at the same time taking advantage of well-tested code like the SOFA and IERS libraries. This presentation will show some of the current capabilities of Where, including benchmarks against other software packages, and outline our plans for further progress. In addition we will report on some investigations we have done experimenting with alternative weighting strategies for VLBI.
A preliminary geodetic data model for geographic information systems
Kelly, K. M.
2009-12-01
Our ability to gather and assimilate integrated data collections from multiple disciplines is important for earth system studies. Moreover, geosciences data collection has increased dramatically, with pervasive networks of observational stations on the ground, in the oceans, in the atmosphere and in space. Contemporary geodetic observations from several space and terrestrial technologies contribute to our knowledge of earth system processes and thus are a valuable source of high accuracy information for many global change studies. Assimilation of these geodetic observations and numerical models into models of weather, climate, oceans, hydrology, ice, and solid Earth processes is an important contribution geodesists can make to the earth science community. Clearly, the geodetic observations and models are fundamental to these contributions. ESRI wishes to provide leadership in the geodetic community to collaboratively build an open, freely available content specification that can be used by anyone to structure and manage geodetic data. This Geodetic Data Model will provide important context for all geographic information. The production of a task-specific geodetic data model involves several steps. The goal of the data model is to provide useful data structures and best practices for each step, making it easier for geodesists to organize their data and metadata in a way that will be useful in their data analyses and to their customers. Built on concepts from the successful Arc Marine data model, we introduce common geodetic data types and summarize the main thematic layers of the Geodetic Data Model. These provide a general framework for envisioning the core feature classes required to represent geodetic data in a geographic information system. Like Arc Marine, the framework is generic to allow users to build workflow or product specific geodetic data models tailored to the specific task(s) at hand. This approach allows integration of the data with other existing
Geodetic Control Points - Multi-State Control Point Database
NSGIC State | GIS Inventory — The Multi-State Control Point Database (MCPD) is a database of geodetic and mapping control covering Idaho and Montana. The control were submitted by registered land...
Geodetic analysis of disputed accurate qibla direction
Saksono, Tono; Fulazzaky, Mohamad Ali; Sari, Zamah
2018-04-01
Muslims perform the prayers facing towards the correct qibla direction would be the only one of the practical issues in linking theoretical studies with practice. The concept of facing towards the Kaaba in Mecca during the prayers has long been the source of controversy among the muslim communities to not only in poor and developing countries but also in developed countries. The aims of this study were to analyse the geodetic azimuths of qibla calculated using three different models of the Earth. The use of ellipsoidal model of the Earth could be the best method for determining the accurate direction of Kaaba from anywhere on the Earth's surface. A muslim cannot direct himself towards the qibla correctly if he cannot see the Kaaba due to setting out process and certain motions during the prayer this can significantly shift the qibla direction from the actual position of the Kaaba. The requirement of muslim prayed facing towards the Kaaba is more as spiritual prerequisite rather than physical evidence.
International Nuclear Information System (INIS)
Muelaner, J E; Wang, Z; Keogh, P S; Brownell, J; Fisher, D
2016-01-01
Understanding the uncertainty of dimensional measurements for large products such as aircraft, spacecraft and wind turbines is fundamental to improving efficiency in these products. Much work has been done to ascertain the uncertainty associated with the main types of instruments used, based on laser tracking and photogrammetry, and the propagation of this uncertainty through networked measurements. Unfortunately this is not sufficient to understand the combined uncertainty of industrial measurements, which include secondary tooling and datum structures used to locate the coordinate frame. This paper presents for the first time a complete evaluation of the uncertainty of large scale industrial measurement processes. Generic analysis and design rules are proven through uncertainty evaluation and optimization for the measurement of a large aero gas turbine engine. This shows how the instrument uncertainty can be considered to be negligible. Before optimization the dominant source of uncertainty was the tooling design, after optimization the dominant source was thermal expansion of the engine; meaning that no further improvement can be made without measurement in a temperature controlled environment. These results will have a significant impact on the ability of aircraft and wind turbines to improve efficiency and therefore reduce carbon emissions, as well as the improved reliability of these products. (paper)
International Nuclear Information System (INIS)
Rosner, J.L.
1987-01-01
This paper reports on a pedagogical introduction that attempts to unify the strong and electroweak interactions. Unifying groups discussed include SU(5), SO(10), and E 6 . Particular attention is paid to the questions of whether the low-energy gauge group (that accessible at accelerator experiments in the foreseeable future) extends beyond SU(3) x SU(2) L x U(1). Low-energy studies of neutral-current effects, direct production of gauge bosons, and new fermions all can shed light on this question. Brief remarks are made concerning the role of monopoles, cosmic strings, baryogenesis, supersymmetry, and higher dimensions in this program
Cromatografia unificada Unified chromatography
Directory of Open Access Journals (Sweden)
Carin von Mühlen
2004-10-01
Full Text Available The scope of this study encompasses an overview of the principles of unified chromatography as well as the principles of chromatographic techniques as applied to unified systems, which include gas chromatography, liquid chromatography, supercritical fluid chromatography, high temperature and high pressure liquid chromatography, micro-liquid chromatography, enhanced fluidity chromatography, and solvating gas chromatography. Theoretical considerations and individual instrumental parameters such as mobile phase, sample introduction system, columns, and detection system are also discussed. Future applications of this separation approach are discussed.
Analysis of Tidal Data for Dagang Tidal Gauge and Study of the Changes for the National Height Datum
Directory of Open Access Journals (Sweden)
WU Fumei
2015-07-01
Full Text Available The main tides affecting Dagang sea level are analyzed and the national height datum is studied by analyzing 1980—2011 hourly tidal data and 1952—2007 monthly mean tidal data. Firstly, the frequencies and amplitudes of main tides including 180 short-period tides and 6 long-period tides are gained by the Fouirer transform. Then the actual amplitudes and their variations of main tides are obtained by the harmonic analysis of the 1980—2011 hourly tidal data, and the changes with about 19 year period can easily be found in the amplitudes of Q1、O1、M2、K1、K2. And then the changes of the mean sea level at Dagang tidal gauge defining national height datum during the period of 1952—2011 are studied by the harmonic analysis and the shifting average of 18.61 year tidal heights. The results of these methods show that the mean sea level at Dagang tidal gauge descended with the speed of 1.07 mm/a and 0.76 mm/a respectively during 1952—1980, and that it ascended with the speed of 1.59 mm/a and 1.62 mm/a respectively during 1980—2011. And finally the difference of 0.14 cm is achieved by the shifting average of 18.61 year tidal heights for 1985 National Height Datum.
Modeling the North American vertical datum of 1988 errors in the conterminous United States
Li, X.
2018-02-01
A large systematic difference (ranging from -20 cm to +130 cm) was found between NAVD 88 (North AmericanVertical Datum of 1988) and the pure gravimetric geoid models. This difference not only makes it very difficult to augment the local geoid model by directly using the vast NAVD 88 network with state-of-the-art technologies recently developed in geodesy, but also limits the ability of researchers to effectively demonstrate the geoid model improvements on the NAVD 88 network. Here, both conventional regression analyses based on various predefined basis functions such as polynomials, B-splines, and Legendre functions and the Latent Variable Analysis (LVA) such as the Factor Analysis (FA) are used to analyze the systematic difference. Besides giving a mathematical model, the regression results do not reveal a great deal about the physical reasons that caused the large differences in NAVD 88, which may be of interest to various researchers. Furthermore, there is still a significant amount of no-Gaussian signals left in the residuals of the conventional regression models. On the other side, the FA method not only provides a better not of the data, but also offers possible explanations of the error sources. Without requiring extra hypothesis tests on the model coefficients, the results from FA are more efficient in terms of capturing the systematic difference. Furthermore, without using a covariance model, a novel interpolating method based on the relationship between the loading matrix and the factor scores is developed for predictive purposes. The prediction error analysis shows that about 3-7 cm precision is expected in NAVD 88 after removing the systematic difference.
Modeling the North American vertical datum of 1988 errors in the conterminous United States
Directory of Open Access Journals (Sweden)
Li X.
2018-02-01
Full Text Available A large systematic difference (ranging from −20 cm to +130 cm was found between NAVD 88 (North AmericanVertical Datum of 1988 and the pure gravimetric geoid models. This difference not only makes it very difficult to augment the local geoid model by directly using the vast NAVD 88 network with state-of-the-art technologies recently developed in geodesy, but also limits the ability of researchers to effectively demonstrate the geoid model improvements on the NAVD 88 network. Here, both conventional regression analyses based on various predefined basis functions such as polynomials, B-splines, and Legendre functions and the Latent Variable Analysis (LVA such as the Factor Analysis (FA are used to analyze the systematic difference. Besides giving a mathematical model, the regression results do not reveal a great deal about the physical reasons that caused the large differences in NAVD 88, which may be of interest to various researchers. Furthermore, there is still a significant amount of no-Gaussian signals left in the residuals of the conventional regression models. On the other side, the FA method not only provides a better not of the data, but also offers possible explanations of the error sources. Without requiring extra hypothesis tests on the model coefficients, the results from FA are more efficient in terms of capturing the systematic difference. Furthermore, without using a covariance model, a novel interpolating method based on the relationship between the loading matrix and the factor scores is developed for predictive purposes. The prediction error analysis shows that about 3-7 cm precision is expected in NAVD 88 after removing the systematic difference.
The Australian Geodetic Observing Program. Current Status and Future Plans
Johnston, G.; Dawson, J. H.
2015-12-01
Over the last decade, the Australian government has through programs like AuScope, the Asia Pacific Reference Frame (APREF), and the Pacific Sea Level Monitoring (PSLM) Project made a significant contribution to the Global Geodetic Observing Program. In addition to supporting the national research priorities, this contribution is justified by Australia's growing economic dependence on precise positioning to underpin efficient transportation, geospatial data management, and industrial automation (e.g., robotic mining and precision agriculture) and the consequent need for the government to guarantee provision of precise positioning products to the Australian community. It is also well recognised within Australia that there is an opportunity to exploit our near unique position as being one of the few regions in the world to see all new and emerging satellite navigation systems including Galileo (Europe), GPS III (USA), GLONASS (Russia), Beidou (China), QZSS (Japan) and IRNSS (India). It is in this context that the Australian geodetic program will build on earlier efforts and further develop its key geodetic capabilities. This will include the creation of an independent GNSS analysis capability that will enable Australia to contribute to the International GNSS Service (IGS) and an upgrade of key geodetic infrastructure including the national VLBI and GNSS arrays. This presentation will overview the significant geodetic activities undertaken by the Australian government and highlight its future plans.
International Nuclear Information System (INIS)
Anon
2011-01-01
A unified European electricity market means a unification and harmonisation of functioning of the national electricity market into one European Market or into one entity. It gives an opportunity to Slovenske elektrarne to open room for their wider activity within Europe where common rules for cross-boarder trade and markets functioning will apply. (author)
International Nuclear Information System (INIS)
Prasad, R.
1975-01-01
Results of researches into Unified Field Theory over the past seven years are presented. The subject is dealt with in chapters entitled: the choice of affine connection, algebraic properties of the vector fields, field laws obtained from the affine connection based on the path integral method, application to quantum theory and cosmology, interpretation of physical theory in terms of geometry. (U.K.)
Energy Technology Data Exchange (ETDEWEB)
Kapetanakis, D. (Technische Univ. Muenchen, Garching (Germany). Physik Dept.); Mondragon, M. (Technische Univ. Muenchen, Garching (Germany). Physik Dept.); Zoupanos, G. (National Technical Univ., Athens (Greece). Physics Dept.)
1993-09-01
We present phenomenologically viable SU(5) unified models which are finite to all orders before the spontaneous symmetry breaking. In the case of two models with three families the top quark mass is predicted to be 178.8 GeV. (orig.)
International Nuclear Information System (INIS)
Kapetanakis, D.; Mondragon, M.; Zoupanos, G.
1993-01-01
We present phenomenologically viable SU(5) unified models which are finite to all orders before the spontaneous symmetry breaking. In the case of two models with three families the top quark mass is predicted to be 178.8 GeV. (orig.)
Chung, Ding-Yu
2002-01-01
The unified theory of physics unifies various phenomena in our observable universe and other universes. The unified theory is based on the zero-energy universe and the space-object structures. Different universes in different developmental stages are the different expressions of the space-object structures. The unified theory is divided into five parts: the space-object structures, cosmology, the periodic table of elementary particles, the galaxy formation, and the extreme force field. The sp...
The Global Geodetic Observing System: Recent Activities and Accomplishments
Gross, R. S.
2017-12-01
The Global Geodetic Observing System (GGOS) of the International Association of Geodesy (IAG) provides the basis on which future advances in geosciences can be built. By considering the Earth system as a whole (including the geosphere, hydrosphere, cryosphere, atmosphere and biosphere), monitoring Earth system components and their interactions by geodetic techniques and studying them from the geodetic point of view, the geodetic community provides the global geosciences community with a powerful tool consisting mainly of high-quality services, standards and references, and theoretical and observational innovations. The mission of GGOS is: (a) to provide the observations needed to monitor, map and understand changes in the Earth's shape, rotation and mass distribution; (b) to provide the global frame of reference that is the fundamental backbone for measuring and consistently interpreting key global change processes and for many other scientific and societal applications; and (c) to benefit science and society by providing the foundation upon which advances in Earth and planetary system science and applications are built. The goals of GGOS are: (1) to be the primary source for all global geodetic information and expertise serving society and Earth system science; (2) to actively promote, sustain, improve, and evolve the integrated global geodetic infrastructure needed to meet Earth science and societal requirements; (3) to coordinate with the international geodetic services that are the main source of key parameters and products needed to realize a stable global frame of reference and to observe and study changes in the dynamic Earth system; (4) to communicate and advocate the benefits of GGOS to user communities, policy makers, funding organizations, and society. In order to accomplish its mission and goals, GGOS depends on the IAG Services, Commissions, and Inter-Commission Committees. The Services provide the infrastructure and products on which all contributions
Leveraging geodetic data to reduce losses from earthquakes
Murray, Jessica R.; Roeloffs, Evelyn A.; Brooks, Benjamin A.; Langbein, John O.; Leith, William S.; Minson, Sarah E.; Svarc, Jerry L.; Thatcher, Wayne R.
2018-04-23
Seismic hazard assessments that are based on a variety of data and the best available science, coupled with rapid synthesis of real-time information from continuous monitoring networks to guide post-earthquake response, form a solid foundation for effective earthquake loss reduction. With this in mind, the Earthquake Hazards Program (EHP) of the U.S. Geological Survey (USGS) Natural Hazards Mission Area (NHMA) engages in a variety of undertakings, both established and emergent, in order to provide high quality products that enable stakeholders to take action in advance of and in response to earthquakes. Examples include the National Seismic Hazard Model (NSHM), development of tools for improved situational awareness such as earthquake early warning (EEW) and operational earthquake forecasting (OEF), research about induced seismicity, and new efforts to advance comprehensive subduction zone science and monitoring. Geodetic observations provide unique and complementary information directly relevant to advancing many aspects of these efforts (fig. 1). EHP scientists have long leveraged geodetic data for a range of influential studies, and they continue to develop innovative observation and analysis methods that push the boundaries of the field of geodesy as applied to natural hazards research. Given the ongoing, rapid improvement in availability, variety, and precision of geodetic measurements, considering ways to fully utilize this observational resource for earthquake loss reduction is timely and essential. This report presents strategies, and the underlying scientific rationale, by which the EHP could achieve the following outcomes: The EHP is an authoritative source for the interpretation of geodetic data and its use for earthquake loss reduction throughout the United States and its territories.The USGS consistently provides timely, high quality geodetic data to stakeholders.Significant earthquakes are better characterized by incorporating geodetic data into USGS
A Community-based Partnership for a Sustainable GNSS Geodetic Network
Dokka, R. K.
2009-12-01
Geodetic networks offer unparalleled opportunities to monitor and understand many of the rhythms of the Earth most vital to the sustainability of modern and future societies, i.e., crustal motions, sea-level, and the weather. For crustal deformation studies, the advantage is clear. Modern measurements allow us to document not only the permanent strains incurred over a seismic cycle, for example, but also the ephemeral strains that are critical for understanding the underlying physical mechanism. To be effective for science, however, geodetic networks must be properly designed, capitalized, and maintained over sufficient time intervals to fully capture the processes in action. Unfortunately, most networks lack interoperability and lack a business plan to ensure long term sustainability. The USA, for example, lacks a unified nation-wide GNSS network that can sustain its self over the coming years, decades, and century. Current federal priorities do not yet envision such a singular network. Publicly and privately funded regional networks exist, but tend to be parochial in scope, and optimized for a special user community, e.g., surveying, crustal motions, etc. Data sharing is common, but the lack of input at the beginning limits the functionality of the system for non-primary users. Funding for private networks depend heavily on the user demand, business cycle, and regulatory requirements. Agencies funding science networks offer no guarantee of sustained support. An alternative model (GULFNet) developed in Louisiana is meeting user needs, is sustainable, and is helping engineers, surveyors, and geologists become more spatially enabled. The common denominator among all participants is the view that accurate, precise, and timely geodetic data have tangible value for all segments of society. Although operated by a university (LSU), GULFNet is a community-based partnership between public and private sectors. GULFNet simultaneously achieves scientific goals by providing
International Nuclear Information System (INIS)
Langacker, P.
1981-01-01
In this talk I discuss the present status of these theories and of their observational and experimental implications. In section II, I briefly review the standard SU 3 sup(c) x SU 2 x U 1 model of the strong and electroweak interactions. Although phenomenologically successful, the standard model leaves many questions unanswered. Some of these questions are addressed by grand unified theories, which are defined and discussed in Section III. The Georgi-Glashow SU 5 model is described, as are theories based on larger groups such as SO 10 , E 6 , or SO 16 . It is emphasized that there are many possible grand unified theories and that it is an experimental problem not only to test the basic ideas but to discriminate between models. (orig./HSI)
DEFF Research Database (Denmark)
Codello, Alessandro; Jain, Rajeev Kumar
2018-01-01
We present a unified evolution of the universe from very early times until the present epoch by including both the leading local correction R2 and the leading non-local term R1□2R to the classical gravitational action. We find that the inflationary phase driven by R2 term gracefully exits...... in a transitory regime characterized by coherent oscillations of the Hubble parameter. The universe then naturally enters into a radiation dominated epoch followed by a matter dominated era. At sufficiently late times after radiation–matter equality, the non-local term starts to dominate inducing an accelerated...... expansion of the universe at the present epoch. We further exhibit the fact that both the leading local and non-local terms can be obtained within the covariant effective field theory of gravity. This scenario thus provides a unified picture of inflation and dark energy in a single framework by means...
DEFF Research Database (Denmark)
Buhl, Kenneth Øhlenschlæger
2012-01-01
Formålet med denne artikel er at se nærmere på erfaringerne fra den maritime kampagne under den militære indsats i konflikten i Libyen i 2011, som i NATO regi blev kendt som Operation Unified Protector (OUP). Dækningen i de danske medier fokuserede primært på luftkampagnen, hvilket må tilskrives,...
Unified Engineering Software System
Purves, L. R.; Gordon, S.; Peltzman, A.; Dube, M.
1989-01-01
Collection of computer programs performs diverse functions in prototype engineering. NEXUS, NASA Engineering Extendible Unified Software system, is research set of computer programs designed to support full sequence of activities encountered in NASA engineering projects. Sequence spans preliminary design, design analysis, detailed design, manufacturing, assembly, and testing. Primarily addresses process of prototype engineering, task of getting single or small number of copies of product to work. Written in FORTRAN 77 and PROLOG.
Kopal, Nils
2016-01-01
In this German seminar paper, which was written in the year 2011 at the University of Duisburg for a Bachelor Colloquium in Applied computer science, we show a brief overview of the Rational Unified Process (RUP). Thus, interested students or generally interested people in software development gain a first impression of RUP. The paper includes a survey and overview of the underlying process structure, the phases of the process, its workflows, and describes the always by the RUP developers pos...
Xiong, X.; Gao, R.; Li, Q.; Wang, H.
2012-12-01
The sedimentary basin and the orogenic belt are the basic two tectonic units of the continental lithosphere, and form the basin-mountain coupling system, The research of which is the key element to the oil and gas exploration, the global tectonic theory and models and the development of the geological theory. The Sichuan basin and adjacent orogenic belts is one of the most ideal sites to research the issues above, in particular by the recent deep seismic profiling datum. From the 1980s to now, there are 11 deep seismic sounding profiles and 6 deep seismic reflection profiles and massive seismic broadband observation stations deployed around and crossed the Sichuan basin, which provide us a big opportunity to research the deep structure and other forward issues in this region. Supported by the National Natural Science Foundation of China (Grant No. 41104056) and the Fundamental Research Funds of the Institute of Geological Sciences, CAGS (No. J1119), we sampled the Moho depth and low-velocity zone depth and the Pn velocity of these datum, then formed the contour map of the Moho depth and Pn velocity by the interpolation of the sampled datum. The result shows the Moho depth beneath Sichuan basin ranges from 40 to 44 km, the sharp Moho offset appears in the western margin of the Sichuan basin, and there is a subtle Moho depression in the central southern part of the Sichuan basin; the P wave velocity can be 6.0 km/s at ca. 10 km deep, and increases gradually deeper, the average P wave velocity in this region is ca. 6.3 km/s; the Pn velocity is ca. 8.0-8.02 km/s in Sichuan basin, and 7.70-7.76 km/s in Chuan-Dian region; the low velocity zone appears in the western margin of the Sichuan basin, which maybe cause the cause of the earthquake.
DEFF Research Database (Denmark)
Iliffe, J.C.; Ziebart, M.; Cross, P.A.
2003-01-01
The background to the recent computation of a new vertical datum model for the British Isles (OSGM02) is described After giving a brief description of the computational techniques and the data sets used for the derivation of the gravimetric geoid, the paper focuses on the fitting of this surface...... to the GPS and levelling networks in the various regions of the British Isles in such a way that it can be used in conjunction with GPS to form a replacement for the existing system of bench marks. The error sources induced in this procedure are discussed, and the theoretical basis given for the fitting...
Error Propagation in Geodetic Networks Studied by FEMLAB
DEFF Research Database (Denmark)
Borre, Kai
2009-01-01
Geodetic networks can be described by discrete models. The observations may be height differences, distances, and directions. Geodesists always make more observations than necessary and estimate the solution by using the principle of least squares. Contemporary networks often contain several thou...
Verification of Positional Accuracy of ZVS3003 Geodetic Control ...
African Journals Online (AJOL)
The International GPS Service (IGS) has provided GPS orbit products to the scientific community with increased precision and timeliness. Many users interested in geodetic positioning have adopted the IGS precise orbits to achieve centimeter level accuracy and ensure long-term reference frame stability. Positioning with ...
Poerbandono
2017-07-01
This paper assesses the presence of navigational hazards due to underestimation of charted depths originated from an establishment of a sea-level-related reference plane, i.e. datum. The study domain is situated in one of Indonesia's densest marine traffic, SW Java Sea, Indonesia. The assessment is based on the comparison of the authorized Chart Datum (CD), being uniformly located at 0.6 m below Mean Sea Level (MSL), and a spatially varying Lowest Astronomical Tide (LAT) generated for the purpose of this research. Hazards are considered here as the deviation of LAT from CD and quantified as the ratio of LAT -CD deviation with respect to the allowable Total Vertical Uncertainty (TVU), i.e. the international standard for accuracy of depth information on nautical charts. Underestimation of charted depth is expected for the case that LAT falls below CD. Such a risk magnifies with decreasing depths, as well as the increasing volume of traffic and draught of the vessel. It is found that most of the domain is in the interior of risk-free zone from using uniform CD. As much as 0.08 and 0.19 parts of the area are in zones where the uncertainty of CD contributes respectively to 50% and 30% of Total Vertical Uncertainty. These are zones where the hazard of navigation is expected to increase due to underestimated lowest tidal level.
Unified Symmetry of Hamilton Systems
International Nuclear Information System (INIS)
Xu Xuejun; Qin Maochang; Mei Fengxiang
2005-01-01
The definition and the criterion of a unified symmetry for a Hamilton system are presented. The sufficient condition under which the Noether symmetry is a unified symmetry for the system is given. A new conserved quantity, as well as the Noether conserved quantity and the Hojman conserved quantity, deduced from the unified symmetry, is obtained. An example is finally given to illustrate the application of the results.
Energy Technology Data Exchange (ETDEWEB)
Kos, L. [LECAD Laboratory, Faculty of Mechanical Engineering, University of Ljubljana, SI-1000 Ljubljana (Slovenia); Tskhakaya, D. D.; Jelić, N. [Institute for Theoretical Physics, Fusion@ÖAW, University of Innsbruck, A-6020 Innsbruck (Austria)
2015-09-15
Recent decades have seen research into the conditions necessary for the formation of the monotonic potential shape in the sheath, appearing at the plasma boundaries like walls, in fluid, and kinetic approximations separately. Although either of these approaches yields a formulation commonly known as the much-acclaimed Bohm criterion (BC), the respective results involve essentially different physical quantities that describe the ion gas behavior. In the fluid approach, such a quantity is clearly identified as the ion directional velocity. In the kinetic approach, the ion behavior is formulated via a quantity (the squared inverse velocity averaged by the ion distribution function) without any clear physical significance, which is, moreover, impractical. In the present paper, we try to explain this difference by deriving a condition called here the Unified Bohm Criterion, which combines an advanced fluid model with an upgraded explicit kinetic formula in a new form of the BC. By introducing a generalized polytropic coefficient function, the unified BC can be interpreted in a form that holds, irrespective of whether the ions are described kinetically or in the fluid approximation.
Frauendorf, S.
2018-04-01
The key elements of the Unified Model are reviewed. The microscopic derivation of the Bohr Hamiltonian by means of adiabatic time-dependent mean field theory is presented. By checking against experimental data the limitations of the Unified Model are delineated. The description of the strong coupling between the rotational and intrinsic degrees of freedom in framework of the rotating mean field is presented from a conceptual point of view. The classification of rotational bands as configurations of rotating quasiparticles is introduced. The occurrence of uniform rotation about an axis that differs from the principle axes of the nuclear density distribution is discussed. The physics behind this tilted-axis rotation, unknown in molecular physics, is explained on a basic level. The new symmetries of the rotating mean field that arise from the various orientations of the angular momentum vector with respect to the triaxial nuclear density distribution and their manifestation by the level sequence of rotational bands are discussed. Resulting phenomena, as transverse wobbling, rotational chirality, magnetic rotation and band termination are discussed. Using the concept of spontaneous symmetry breaking the microscopic underpinning of the rotational degrees is refined.
Influence of bad measurements in properties of GeodeticNnetwork
Directory of Open Access Journals (Sweden)
Vincent Jakub
2008-12-01
Full Text Available In establishment of LGS (Local geodetic Net some given coordinated points from the relevant area are used, new points areestablished and the required distances and angles among the points are measured. If some measurements are defective, the netadjustment with the obtained values is depreciated, unacceptable. In the paper there is given an identification method of incorrectmeasurement results. The faulty results are eliminated in a new adjustment or the relevant defective measurements are repeated forobtaining correct values.
Geodetic Volcano Monitoring Research in Canary Islands: Recent Results
Fernandez, J.; Gonzalez, P. J.; Arjona, A.; Camacho, A. G.; Prieto, J. F.; Seco, A.; Tizzani, P.; Manzo, M. R.; Lanari, R.; Blanco, P.; Mallorqui, J. J.
2009-05-01
The Canarian Archipelago is an oceanic island volcanic chain with a long-standing history of volcanic activity (> 40 Ma). It is located off the NW coast of the African continent, lying over a transitional crust of the Atlantic African passive margin. At least 12 eruptions have been occurred on the islands of Lanzarote, Tenerife and La Palma in the last 500 years. Volcanism manifest predominantly as basaltic strombolian monogenetic activity (whole archipelago) and central felsic volcanism (active only in Tenerife Island). We concentrate our studies in the two most active islands, Tenerife and La Palma. In these islands, we tested different methodologies of geodetic monitoring systems. We use a combination of ground- and space-based techniques. At Tenerife Island, a differential interferometric study was performed to detect areas of deformation. DInSAR detected two clear areas of deformation, using this results a survey-based GPS network was designed and optimized to control those deformations and the rest of the island. Finally, using SBAS DInSAR results weak spatial long- wavelength subsidence signals has been detected. At La Palma, the first DInSAR analysis have not shown any clear deformation, so a first time series analysis was performed detecting a clear subsidence signal at Teneguia volcano, as for Tenerife a GPS network was designed and optimized taking into account stable and deforming areas. After several years of activities, geodetic results served to study ground deformations caused by a wide variety of sources, such as changes in groundwater levels, volcanic activity, volcano-tectonics, gravitational loading, etc. These results proof that a combination of ground-based and space-based techniques is suitable tool for geodetic volcano monitoring in Canary Islands. Finally, we would like to strength that those results could have serious implications on the continuous geodetic monitoring system design and implementation for the Canary Islands which is under
Direction: unified theory of interactions
International Nuclear Information System (INIS)
Valko, P.
1987-01-01
Briefly characterized are the individual theories, namely, the general relativity theory, the Kaluza-Klein theory, the Weyl theory, the unified theory of electromagnetic and weak interactions, the supergravity theory, and the superstring theory. The history is recalled of efforts aimed at creating a unified theory of interactions, and future prospects are outlined. (M.D.). 2 figs
International Nuclear Information System (INIS)
Ellis, J.
1982-01-01
The author gives an introduction to the construction of grand unified theories on the base of the SU(3)xSU(2)xU(1) model of the strong, weak, and electromagnetic interactions. Especially he discusses the proton decay, neutrino masses and oscillations, and cosmological implications in connection with grand unified theories. (orig./HSI)
An Overview of Geodetic Volcano Research in the Canary Islands
Fernández, José; González, Pablo J.; Camacho, Antonio G.; Prieto, Juan F.; Brú, Guadalupe
2015-11-01
The Canary Islands are mostly characterized by diffuse and scattered volcanism affecting a large area, with only one active stratovolcano, the Teide-Pico Viejo complex (Tenerife). More than 2 million people live and work in the 7,447 km2 of the archipelago, resulting in an average population density three times greater than the rest of Spain. This fact, together with the growth of exposure during the past 40 years, increases volcanic risk with respect previous eruptions, as witnessed during the recent 2011-2012 El Hierro submarine eruption. Therefore, in addition to purely scientific reasons there are economic and population-security reasons for developing and maintaining an efficient volcano monitoring system. In this scenario geodetic monitoring represents an important part of the monitoring system. We describe volcano geodetic monitoring research carried out in the Canary Islands and the results obtained. We consider for each epoch the two main existing constraints: the level of volcanic activity in the archipelago, and the limitations of the techniques available at the time. Theoretical and observational aspects are considered, as well as the implications for operational volcano surveillance. Current challenges of and future perspectives in geodetic volcano monitoring in the Canaries are also presented.
Seven Deadliest Unified Communications Attacks
York, Dan
2010-01-01
Do you need to keep up with the latest hacks, attacks, and exploits effecting Unified Communications technology? Then you need Seven Deadliest Unified Communication Attacks. This book pinpoints the most dangerous hacks and exploits specific to Unified Communications, laying out the anatomy of these attacks including how to make your system more secure. You will discover the best ways to defend against these vicious hacks with step-by-step instruction and learn techniques to make your computer and network impenetrable. Attacks featured in this book include: UC Ecosystem Attacks Insecure Endpo
Directory of Open Access Journals (Sweden)
Doskocz Adam
2016-01-01
Full Text Available All official data are currently integrated and harmonized in a spatial reference system. This paper outlines a national geodetic and cartographic resources in Poland. The national geodetic and cartographic resources are an important part of the spatial information infrastructure in the European Community. They also provide reference data for other resources of Spatial Data Infrastructure (SDI, including: main and detailed geodetic control networks, base maps, land and buildings registries, geodetic registries of utilities and topographic maps. This paper presents methods of producing digital map data and technical standards for field surveys, and in addition paper also presents some aspects of building Global and Regional SDI.
An Autonomous, Low Cost Platform for Seafloor Geodetic Observations
Ericksen, T.; Foster, J. H.; Bingham, B. S.
2013-12-01
The high cost of acquiring geodetic data from the sea floor has limited the observations available to help us understand and model the behavior of seafloor geodetic processes. To address this problem, the Pacific GPS Facility at the University of Hawaii is developing a cost effective approach for accurately measuring short-term vertical motions of the seafloor and maintaining a continuous long-term record of seafloor pressure without the requirement for costly ship time. There is a recognized need to vastly increase our underwater geodetic observing capacity. Most of the largest recorded earthquakes and most devastating tsunamis are generated at subduction zones underwater. Similarly, many volcanoes are partly (e.g. Santorini) or completely (e.g. Loihi) submerged, and are not well observed and understood. Furthermore, landslide features ring many ocean basins, and huge debris deposits surround many volcanic oceanic islands. Our approach will lower the cost of collecting sea-floor geodetic data, reducing the barriers preventing us from acquiring the information we need to observe and understand these types of structures and provide a direct societal benefit in improving hazard assessment. The capability is being developed by equipping one of the University of Hawaii Wave Gliders with an integrated acoustic telemetry package, a dual frequency geodetic-grade Global Positioning System (GPS) receiver, processing unit, and cellular communications. The Wave Glider will interrogate high accuracy pressure sensors on the sea floor to maintain a near-continuous stream of pressure and temperature data, but seafloor pressure data includes contribution from a variety of sources and on its own may not provide the accuracy required for geodetic investigations. Independent measurements of sea surface pressure and sea surface height can be used to remove these contributions from the observed sea floor pressure timeseries. We will integrate our seafloor pressure measurements with air
UPQC (Unified power Quality Conditioner)
Indian Academy of Sciences (India)
First page Back Continue Last page Graphics. UPQC (Unified power Quality Conditioner). Hybrid of Shunt and Series compensator. Compensate both Current Quality and Voltage Quality. Costlier Solution as it involves two set of Inverters.
International Nuclear Information System (INIS)
Leite Lopes, J.
1998-04-01
In this work, we discuss the physical ideas which represents the basis for the unified gauge field model. Despite of the difficulties that we presently have for embodying in a natural manner muons and hadrons in that model, we have the feeling that we are on the way which seems to lead to the construction of a theory in which the Maxwell electromagnetic field and the Fermi weak interaction field are manifestations of a unique subjacent physical entity - the unified gauge fields. (author)
Geodetic Space Weather Monitoring by means of Ionosphere Modelling
Schmidt, Michael
2017-04-01
The term space weather indicates physical processes and phenomena in space caused by radiation of energy mainly from the Sun. Manifestations of space weather are (1) variations of the Earth's magnetic field, (2) the polar lights in the northern and southern hemisphere, (3) variations within the ionosphere as part of the upper atmosphere characterized by the existence of free electrons and ions, (4) the solar wind, i.e. the permanent emission of electrons and photons, (5) the interplanetary magnetic field, and (6) electric currents, e.g. the van Allen radiation belt. It can be stated that ionosphere disturbances are often caused by so-called solar storms. A solar storm comprises solar events such as solar flares and coronal mass ejections (CMEs) which have different effects on the Earth. Solar flares may cause disturbances in positioning, navigation and communication. CMEs can effect severe disturbances and in extreme cases damages or even destructions of modern infrastructure. Examples are interruptions to satellite services including the global navigation satellite systems (GNSS), communication systems, Earth observation and imaging systems or a potential failure of power networks. Currently the measurements of solar satellite missions such as STEREO and SOHO are used to forecast solar events. Besides these measurements the Earth's ionosphere plays another key role in monitoring the space weather, because it responses to solar storms with an increase of the electron density. Space-geodetic observation techniques, such as terrestrial GNSS, satellite altimetry, space-borne GPS (radio occultation), DORIS and VLBI provide valuable global information about the state of the ionosphere. Additionally geodesy has a long history and large experience in developing and using sophisticated analysis and combination techniques as well as empirical and physical modelling approaches. Consequently, geodesy is predestinated for strongly supporting space weather monitoring via
Research in Application of Geodetic GPS Receivers in Time Synchronization
Zhang, Q.; Zhang, P.; Sun, Z.; Wang, F.; Wang, X.
2018-04-01
In recent years, with the development of satellite orbit and clock parameters accurately determining technology and the popularity of geodetic GPS receivers, Common-View (CV) which proposed in 1980 by Allan has gained widespread application and achieved higher accuracy time synchronization results. GPS Common View (GPS CV) is the technology that based on multi-channel geodetic GPS receivers located in different place and under the same common-view schedule to receiving same GPS satellite signal at the same time, and then calculating the time difference between respective local receiver time and GPST by weighted theory, we will obtain the difference between above local time of receivers that installed in different station with external atomic clock. Multi-channel geodetic GPS receivers have significant advantages such as higher stability, higher accuracy and more common-view satellites in long baseline time synchronization application over the single-channel geodetic GPS receivers. At present, receiver hardware delay and surrounding environment influence are main error factors that affect the accuracy of GPS common-view result. But most error factors will be suppressed by observation data smoothing and using of observation data from different satellites in multi-channel geodetic GPS receiver. After the SA (Selective Availability) cancellation, using a combination of precise satellite ephemeris, ionospheric-free dual-frequency P-code observations and accurately measuring of receiver hardware delay, we can achieve time synchronization result on the order of nanoseconds (ns). In this paper, 6 days observation data of two IGS core stations with external atomic clock (PTB, USNO distance of two stations about 6000 km) were used to verify the GPS common-view theory. Through GPS observation data analysis, there are at least 2-4 common-view satellites and 5 satellites in a few tracking periods between two stations when the elevation angle is 15°, even there will be at least
RESEARCH IN APPLICATION OF GEODETIC GPS RECEIVERS IN TIME SYNCHRONIZATION
Directory of Open Access Journals (Sweden)
Q. Zhang
2018-04-01
Full Text Available In recent years, with the development of satellite orbit and clock parameters accurately determining technology and the popularity of geodetic GPS receivers, Common-View (CV which proposed in 1980 by Allan has gained widespread application and achieved higher accuracy time synchronization results. GPS Common View (GPS CV is the technology that based on multi-channel geodetic GPS receivers located in different place and under the same common-view schedule to receiving same GPS satellite signal at the same time, and then calculating the time difference between respective local receiver time and GPST by weighted theory, we will obtain the difference between above local time of receivers that installed in different station with external atomic clock. Multi-channel geodetic GPS receivers have significant advantages such as higher stability, higher accuracy and more common-view satellites in long baseline time synchronization application over the single-channel geodetic GPS receivers. At present, receiver hardware delay and surrounding environment influence are main error factors that affect the accuracy of GPS common-view result. But most error factors will be suppressed by observation data smoothing and using of observation data from different satellites in multi-channel geodetic GPS receiver. After the SA (Selective Availability cancellation, using a combination of precise satellite ephemeris, ionospheric-free dual-frequency P-code observations and accurately measuring of receiver hardware delay, we can achieve time synchronization result on the order of nanoseconds (ns. In this paper, 6 days observation data of two IGS core stations with external atomic clock (PTB, USNO distance of two stations about 6000 km were used to verify the GPS common-view theory. Through GPS observation data analysis, there are at least 2–4 common-view satellites and 5 satellites in a few tracking periods between two stations when the elevation angle is 15°, even
The University, the Market, and the Geodetic Engineer or
DEFF Research Database (Denmark)
Stubkjær, Erik
2002-01-01
In Europe, universities have existed for more than 800 years. The university is the place in society for higher learning and related research. Through the ages, the universities have enjoyed a remarkably freedom relative to religious and secular powers. In recent years, the objectives and practises...... project, which concerned the education of geodetic engineers in Slovenia. The body of the paper presents a selection of ideas that shaped the university through the centuries, with a view to balance the present interest in advancing market-directed behaviour....
Current status of the EPOS WG4 - GNSS and Other Geodetic Data
Fernandes, Rui; Bastos, Luisa; Bruyninx, Carine; D'Agostino, Nicola; Dousa, Jan; Ganas, Athanassios; Lidberg, Martin; Nocquet, Jean-Mathieu
2014-05-01
WG4 - "EPOS Geodetic Data and Other Geodetic Data" is the Working Group of the EPOS project in charge of defining and preparing the integration of the existing Pan-European Geodetic Infrastructures that will support European Geosciences, which is the ultimate goal of the EPOS project. The WG4 is formed by representatives of the participating EPOS countries (23) but it is also open to the entire geodetic community. In fact, WG4 also already includes members from countries that formally are not integrating EPOS in this first step. The geodetic component of EPOS (WG4) is dealing essentially with Research Infrastructures focused on continuous operating GNSS (cGNSS) in the current phase. The option of concentrating the efforts on the presently most generalized geodetic tool supporting research on Solid Earth was decided in order to optimize the existing resources. Nevertheless, WG4 will continue to pursue the development of tools and methodologies that permit the access of the EPOS community to other geodetic information (e.g., gravimetry). Furthermore, although the focus is on Solid Earth applications, other research and technical applications (e.g., reference frames, meteorology, space weather) can also benefit from the efforts of WG4 EPOS towards the optimization of the geodetic resources in Europe. We will present and discuss the plans for the implementation of the thematic and core services (TCS) for geodetic data within EPOS and the related business plan. We will focus on strategies towards the implementation of the best solutions that will permit to the end-users, and in particular geo-scientists, to access the geodetic data, derived solutions, and associated metadata using transparent and uniform processes. Five pillars have been defined proposed for the TCS: Dissemination, Preservation, Monitoring, and Analysis of geodetic data plus the Support and Governance Infrastructure. Current proposals and remaining open questions will be discussed.
SIRGAS: the core geodetic infrastructure in Latin America and the Caribbean
Sanchez, L.; Brunini, C.; Drewes, H.; Mackern, V.; da Silva, A.
2013-05-01
Studying, understanding, and modelling geophysical phenomena, such as global change and geodynamics, require geodetic reference frames with (1) an order of accuracy higher than the magnitude of the effects we want to study, (2) consistency and reliability worldwide (the same accuracy everywhere), and (3) a long-term stability (the same order of accuracy at any time). The definition, realisation, maintenance, and wide-utilisation of the International Terrestrial Reference System (ITRS) are oriented to guarantee a globally unified geometric reference frame with reliability at the mm-level, i.e. the International Terrestrial Reference Frame (ITRF). The densification of the global ITRF in Latin America and The Caribbean is given by SIRGAS (Sistema de Referencia Geocéntrico para Las Américas), primary objective of which is to provide the most precise coordinates in the region. Therefore, SIRGAS is the backbone for all regional projects based on the generation, use, and analysis of geo-referenced data at national as well as at international level. Besides providing the reference for a wide range of scientific applications such as the monitoring of Earth's crust deformations, vertical movements, sea level variations, atmospheric studies, etc., SIRGAS is also the platform for practical applications such as engineering projects, digital administration of geographical data, geospatial data infrastructures, etc. According to this, the present contribution describes the main features of SIRGAS, giving special care to those challenges faced to continue providing the best possible, long-term stable and high-precise reference frame for Latin America and the Caribbean.
Geodetic refraction effects of electromagnetic wave propagation through the atmosphere
1984-01-01
With very few exceptions, geodetic measurements use electro magnetic radiation in order to measure directions, distances, time delays, and Doppler frequency shifts, to name the main ter restrial and space observables. Depending on the wavelength of the radiation and the purpose of the measurements, the follow ing parameters of the electromagnetic wave are measured: ampli tude, phase, angle-of-arrival, polarisation and frequency. Ac curate corrections have to be applied to the measurements in order to take into account the effects of the intervening medium between transmitter and receiver. The known solutions use at mospheric models, special observation programs, remote sensing techniques and instrumental methods. It has been shown that the effects of the earth's atmospheric envelope present a fundamental limitation to the accuracy and precision of geodetic measurements. This applies equally to ter restrial and space applications. Instrumental accuracies are al ready below the atmospherically i...
Adjustment of positional geodetic networks by unconventional estimations
Directory of Open Access Journals (Sweden)
Silvia Gašincová
2010-06-01
Full Text Available The content of this paper is the adjustment of positional geodetic networks by robust estimations. The techniques (basedon the unconventional estimations of repeated least-square method which have turned out to be suitable and applicable in the practisehave been demonstrated on the example of the local geodetic network, which was founded to compose this thesis. In the thesisthe following techniques have been chosen to compare the Method of least-squares with those many published in foreign literature:M-estimation of Biweight,M-estimation of Welsch and Danish method. All presented methods are based on the repeated least-squaremethod principle with gradual changing of weight of individual measurements. In the first stage a standard least-square method wascarried out in the following steps – iterations we gradually change individual weights according to the relevant instructions/ regulation(so-called weight function. Iteration process will be stopped when no deviated measurements are found in the file of measured data.MatLab programme version 5.2 T was used to implement mathematical adjustment.
Geodetic and seismological investigation in the Ionian area
Directory of Open Access Journals (Sweden)
F. Riguzzi
1997-06-01
Full Text Available Geodetic and seismic evidence of crustal deformations in the Ionian area are shown in this paper. The Ionian GPS network, composed of nine sites crossing the Ionian Sea from Calabria, Southern Italy, to Northwestern Greece, was established and surveyed in 1991, 1994, 1995 within the framework of the TYRGEONET project (Anzidei et al., 1996. In 1996 a return campaign was carried out after the occurrence of seismic activity in 1995. The displacement pattern obtained for the Greek side of the network agrees well with those previously displayed, both in magnitude and direction, confirming a mean displacement rate of about 1-2 cm1/yr. The same agreement is not found for the Italian side of the network, where no significant deformations were detected between 1994 and 1996. Seismic deformation was also studied for the same area, starting from the moment tensors of events which occurred in the last 20 years with magnitude greater than 5.0; evident similarity with the displacement field exhibited by the Greek side of the Ionian Sea by geodetic surveys was inferred. On the contrary, the motion detected for the Italian area cannot be simply related to seismic activity.
Geodetic contributions to IWRM-projects in middle Java, Indonesia
Schmitt, Günter
2010-12-01
The district of Gunung Kidul in middle Java is one of the poorest regions in Indonesia. The essential reason is the acute water scarcity in this karst region during the months of the dry season. As a consequence of the poor living conditions many people have migrated away and therefore the development of the region is stagnating. During the last few years two projects have been initiated under the theme “Integrated Water Resources Management” in order to improve the water supply situation, both funded by the German Federal Ministry of Education and Research, and realized essentially by institutes of the University of Karlsruhe. Geodetic sub-projects are integrated into both projects. Special surveying activities had been, and have still to be, carried out to realise the geometrical basis for several other sub-projects. The particular contributions are 3D cave measurements for visualisation and planning, staking out of drilling points and construction axes, the definition of a common reference system, the surveying of the water distribution network and its technical facilities, the setting up and the management of a geographical information system (GIS), as well as special measurements such as dam monitoring or controlling of a vertical drilling machine. The paper reviews these projects and describes the geodetic activities.
NSGIC State | GIS Inventory — Geodetic Control Points dataset current as of 1995. Benchmarks; Vertical elevation bench marks for monumented geodetic survey control points for which mean sea level...
Plate motions and deformations from geologic and geodetic data
Jordan, T. H.
1986-06-01
Research effort on behalf of the Crustal Dynamics Project focused on the development of methodologies suitable for the analysis of space-geodetic data sets for the estimation of crustal motions, in conjunction with results derived from land-based geodetic data, neo-tectonic studies, and other geophysical data. These methodologies were used to provide estimates of both global plate motions and intraplate deformation in the western U.S. Results from the satellite ranging experiment for the rate of change of the baseline length between San Diego and Quincy, California indicated that relative motion between the North American and Pacific plates over the course of the observing period during 1972 to 1982 were consistent with estimates calculated from geologic data averaged over the past few million years. This result, when combined with other kinematic constraints on western U.S. deformation derived from land-based geodesy, neo-tectonic studies, and other geophysical data, places limits on the possible extension of the Basin and Range province, and implies significant deformation is occurring west of the San Andreas fault. A new methodology was developed to analyze vector-position space-geodetic data to provide estimates of relative vector motions of the observing sites. The algorithm is suitable for the reduction of large, inhomogeneous data sets, and takes into account the full position covariances, errors due to poorly resolved Earth orientation parameters and vertical positions, and reduces baises due to inhomogeneous sampling of the data. This methodology was applied to the problem of estimating the rate-scaling parameter of a global plate tectonic model using satellite laser ranging observations over a five-year interval. The results indicate that the mean rate of global plate motions for that interval are consistent with those averaged over several million years, and are not consistent with quiescent or greatly accelerated plate motions. This methodology was also
Experimental status of unified theories
International Nuclear Information System (INIS)
Bilen'kij, S.M.
1979-01-01
A standard SU(2)xU(1) theory is discussed. It is based on an assumption that the left components of fields form doublets, and the rignt ones - singlets. From the weak interaction lagrangian an expression is obtained for the effective hamiltonian describing neutrino-lepton processes. The results of discussing the experimental status of the unified theories of weak and electromagnetic interactions are in agreement with the simplest version of the unified theories - the Weinberg-Salam theory. It has been noted that the accuracy of the experiments (not exceeding 20%) is insufficient and no information is available on diagonal terms of the hamiltonian
The Simplest Unified Growth Theory
DEFF Research Database (Denmark)
Strulik, Holger; Weisdorf, Jacob Louis
This paper provides a unified growth theory, i.e. a model that explains the very long-run economic and demographic development path of industrialized economies, stretching from the pre-industrial era to present-day and beyond. Making strict use of Malthus' (1798) so-called preventive check...... hypothesis - that fertility rates vary inversely with the price of food - the current study offers a new and straightforward explanation for the demographic transition and the break with the Malthusian era. The current framework lends support to existing unified growth theories and is well in tune...
Encouraging Deep Approach to Learning in Civil and Geodetic Engineering
Directory of Open Access Journals (Sweden)
Gašper Mrak
2016-10-01
Full Text Available This paper presents activities and changes applied to the teaching process within selected courses offered by Faculty of civil and geodetic engineering, University of Ljubljana, Slovenia. Theoretical background, evaluated from the point of the technical education needs, is presented. It can be seen that special focus has to be made to the students' motivation for deep learning which guarantees optimal balance between acquisition of concepts and skills, information processing and integration of fragmented pieces of knowledge into complex structures. Three case studies used to test theoretical points of departure are presented. Results of the introduced novelties and changes have been evaluated through the assessment of knowledge, students' satisfaction and teaching staff evaluations. For conclusive results, monitoring over a longer period of time should be conducted.
Directory of Open Access Journals (Sweden)
Wei Zhou
2016-01-01
Full Text Available This study proposes an improved metabolism grey model [IMGM(1,1] to predict small samples with a singular datum, which is a common phenomenon in daily economic data. This new model combines the fitting advantage of the conventional GM(1,1 in small samples and the additional advantages of the MGM(1,1 in new real-time data, while overcoming the limitations of both the conventional GM(1,1 and MGM(1,1 when the predicted results are vulnerable at any singular datum. Thus, this model can be classified as an improved grey prediction model. Its improvements are illustrated through a case study of sulfur dioxide emissions in China from 2007 to 2013 with a singular datum in 2011. Some features of this model are presented based on the error analysis in the case study. Results suggest that if action is not taken immediately, sulfur dioxide emissions in 2016 will surpass the standard level required by the Twelfth Five-Year Plan proposed by the China State Council.
Land water storage from space and the geodetic infrastructure
Cazenave, A.; Larson, K.; Wahr, J.
2009-04-01
In recent years, remote sensing techniques have been increasingly used to monitor components of the water balance of large river basins. By complementing scarce in situ observations and hydrological modelling, space observations have the potential to significantly improve our understanding of hydrological processes at work in river basins and their relationship with climate variability and socio-economic life. Among the remote sensing tools used in land hydrology, several originate from space geodesy and are integral parts of the Global Geodetic Observing System. For example, satellite altimetry is used for systematic monitoring of water levels of large rivers, lakes and floodplains. InSAR allows the detection of surface water change. GRACE-based space gravity offers for the first time the possibility of directly measuring the spatio-temporal variations of the vertically integrated water storage in large river basins. GRACE is also extremely useful for measuring changes in mass of the snow pack in boreal regions. Vertical motions of the ground induced by changes in water storage in aquifers can be measured by both GPS and InSAR. These techniques can also be used to investigate water loading effects. Recently GPS has been used to measure changes in surface soil moisture, which would be important for agriculture, weather prediction, and for calibrationg satellite missions such as SMOS and SMAP. These few examples show that space and ground geodetic infrastructures are increasingly important for hydrological sciences and applications. Future missions like SWOT (Surface Waters Ocean Topography; a wide swath interferometric altimetry mission) and GRACE 2 (space gravimetry mission based on new technology) will provide a new generation of hydrological products with improved precision and resolution.
DETECTION OF COASTLINE DEFORMATION USING REMOTE SENSING AND GEODETIC SURVEYS
Directory of Open Access Journals (Sweden)
A. Sabuncu
2016-06-01
Full Text Available The coastal areas are being destroyed due to the usage that effect the natural balance. Unconsciously sand mining from the sea for nearshore nourishment and construction uses are the main ones. Physical interferences for mining of sand cause an ecologic threat to the coastal environment. However, use of marine sand is inevitable because of economic reasons or unobtainable land-based sand resources. The most convenient solution in such a protection–usage dilemma is to reduce negative impacts of sand production from marine. This depends on the accurate determination of criteriaon production place, style, and amount of sand. With this motivation, nearshore geodedic surveying studies performed on Kilyos Campus of Bogazici University located on the Black Sea coast, north of Istanbul, Turkey between 2001-2002. The study area extends 1 km in the longshore. Geodetic survey was carried out in the summer of 2001 to detect the initial condition for the shoreline. Long-term seasonal changes in shoreline positions were determined biannually. The coast was measured with post-processed kinematic GPS. Besides, shoreline change has studied using Landsat imagery between the years 1986-2015. The data set of Landsat 5 imageries were dated 05.08.1986 and 31.08.2007 and Landsat 7 imageries were dated 21.07.2001 and 28.07.2015. Landcover types in the study area were analyzed on the basis of pixel based classification method. Firstly, unsupervised classification based on ISODATA (Iterative Self Organizing Data Analysis Technique has been applied and spectral clusters have been determined that gives prior knowledge about the study area. In the second step, supervised classification was carried out by using the three different approaches which are minimum-distance, parallelepiped and maximum-likelihood. All pixel based classification processes were performed with ENVI 4.8 image processing software. Results of geodetic studies and classification outputs will be
Landing, Ed; Geyer, Gerd; Brasier, Martin D.; Bowring, Samuel A.
2013-08-01
Use of the first appearance datum (FAD) of a fossil to define a global chronostratigraphic unit's base can lead to intractable correlation and stability problems. FADs are diachronous—they reflect species' evolutionary history, dispersal, biofacies, preservation, collection, and taxonomy. The Cambrian Evolutionary Radiation is characterised by diachronous FADs, biofacies controls, and provincialism of taxa and ecological communities that confound a stable Lower Cambrian chronostratigraphy. Cambrian series and stage definitions require greater attention to assemblage zone successions and non-biostratigraphic, particularly carbon isotope, correlation techniques such as those that define the Ediacaran System base. A redefined, basal Cambrian Trichophycus pedum Assemblage Zone lies above the highest Ediacaran-type biotas (vendobionts, putative metazoans, and calcareous problematica such as Cloudina) and the basal Asteridium tornatum-Comasphaeridium velvetum Zone (acritarchs). This definition and the likely close correspondence of evolutionary origin and local FAD of T. pedum preserves the Fortune Head, Newfoundland, GSSP of the Cambrian base and allows the presence of sub-Cambrian, branched ichnofossils. The sub-Tommotian-equivalent base of Stage 2 (a suggested "Laolinian Stage") should be defined by the I'/L4/ZHUCE δ13C positive peak, bracketed by the lower ranges of Watsonella crosbyi and Aldanella attleborensis (molluscs) and the Skiagia ornata-Fimbrioglomerella membranacea Zone (acritarchs). The W. crosbyi and A. attleborensis FADs cannot define a Stage 2 base as they are diachronous even in the Newfoundland "type" W. crosbyi Zone. The Series 2 base cannot be based on a species' FAD owing to the provincialism of skeletalised metazoans in the Terreneuvian-Series 2 boundary interval and global heterochrony of the oldest trilobites. A Series 2 and Stage 3 (a suggested "Lenaldanian Series" and "Zhurinskyan Stage," new) GSSP base is proposed at the Siberian lower
Directory of Open Access Journals (Sweden)
Maria Chiara Pievatolo
2013-07-01
Full Text Available Is it right to wage war to export democracy, or - as Kant would have said - to forcibly interfere in the constitution and in the government of another state with the goal of transforming it into a republic? The answer of Kant, contained in the fifth preliminary article of the Perpetual Peace, leans towards non-interventionism: a bad constitution can never justify a war, because it may be the root only of a scandalum acceptum. To understand the meaning of scandalum acceptum we have to become aware that it is a term originating from moral theology, which we should translate into the language of international law. The scandal, as it was still clear to Kant’s contemporaries, is the sin of advertising a sinful behavior: but it is just a scandalum acceptum if the act that inspired others to sin has been done without the intention to give them a bad example. A flawed constitution can be only the occasion of a scandalum acceptum because its legal power does not spread its influence beyond the border of its state. If a nation chooses to imitate the allegedly wrong constitution of another state, its choice depends only on its sovereignty, because it is a matter of internal constitutional law. On the other hand, waging war against another country because of its allegedly flawed constitution is a worse kind of scandal, the scandalum datum, because it involves an international law principle of limited sovereignty according to which every state has the right to assault another state because of its constitution.
Toward a Unified Communication Theory.
McMillan, Saundra
After discussing the nature of theory itself, the author explains her concept of the Unified Communication Theory, which rests on the assumption that there exists in all living structures a potential communication factor which is delimited by species and ontogeny. An organism develops "symbol fixation" at the level where its perceptual abilities…
A model unified field equation
International Nuclear Information System (INIS)
Perring, J.K.; Skyrme, T.H.R.
1994-01-01
The classical solutions of a unified field theory in a two-dimensional space-time are considered. This system, a model of a interacting mesons and baryons, illustrates how the particle can be built from a wave-packet of mesons and how reciprocally the meson appears as a tightly bound combination of particle and antiparticle. (author). 6 refs
Stress coupling in the seismic cycle indicated from geodetic measurements
Wang, L.; Hainzl, S.; Zoeller, G.; Holschneider, M.
2012-12-01
The seismic cycle includes several phases, the interseismic, coseismic and postseismic phase. In the interseismic phase, strain gradually builds up around the overall locked fault in tens to thousands of years, while it is coseismically released in seconds. In the postseismic interval, stress relaxation lasts months to years, indicated by evident aseismic deformations which have been indicated to release comparable or even higher strain energy than the main shocks themselves. Benefiting from the development of geodetic observatory, e.g., Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR) in the last two decades, the measurements of surface deformation have been significantly improved and become valuable information for understanding the stress evolution on the large fault plane. In this study, we utilize the GPS/InSAR data to investigate the slip deficit during the interseismic phase, the coseismic slip and the early postseismic creep on the fault plane. However, it is already well-known that slip inversions based only on the surface measurements are typically non-unique and subject to large uncertainties. To reduce the ambiguity, we utilize the assumption of stress coupling between interseismic and coseismic phases, and between coseismic and postseismic phases. We use a stress constrained joint inversion in Bayesian approach (Wang et al., 2012) to invert simultaneously for (1) interseismic slip deficit and coseismic slip, and (2) coseismic slip and postseismic creep. As case studies, we analyze earthquakes occurred in well-instrumented regions such as the 2004 M6.0 Parkfield earthquake, the 2010 M8.7 earthquake and the 2011 M9.1 Tohoku-Oki earthquake. We show that the inversion with the stress-coupling constraint leads to better constrained slip distributions. Meanwhile, the results also indicate that the assumed stress coupling is reasonable and can be well reflected from the available geodetic measurements. Reference: Lifeng
Unified theory of effective interaction
Energy Technology Data Exchange (ETDEWEB)
Takayanagi, Kazuo, E-mail: k-takaya@sophia.ac.jp
2016-09-15
We present a unified description of effective interaction theories in both algebraic and graphic representations. In our previous work, we have presented the Rayleigh–Schrödinger and Bloch perturbation theories in a unified fashion by introducing the main frame expansion of the effective interaction. In this work, we start also from the main frame expansion, and present various nonperturbative theories in a coherent manner, which include generalizations of the Brandow, Brillouin–Wigner, and Bloch–Horowitz theories on the formal side, and the extended Krenciglowa–Kuo and the extended Lee–Suzuki methods on the practical side. We thus establish a coherent and comprehensive description of both perturbative and nonperturbative theories on the basis of the main frame expansion.
Split supersymmetry in unified models
International Nuclear Information System (INIS)
Dutta, Bhaskar; Mimura, Yukihiro
2005-01-01
In the context of split supersymmetry, the gaugino mass spectrum seems to be very important to satisfy the dark matter content of the universe and the gauge coupling unification. In this Letter, we have considered various sources of gaugino masses in the context of unified models. We show that the gaugino mass spectrum varies in different unification pictures. In the context of SU(5), we have found that the bino/wino mass ratio can be close to one at the weak scale which is helpful to satisfy the WMAP data. The gluino/wino mass ratio is also different from the usual scenario of unified gaugino masses. The gaugino masses can be around one TeV and m SUSY is chosen so that the gluino mass does not create any cosmological problem. In the context of the Pati-Salam model, we show that the gluino mass can be made very heavy even after maintaining the unification of the gauge couplings
Geodetic and geophysical observations in Antarctica an overview in the IPY perspective
Capra, Alessandro
2008-01-01
This book is a collection of papers on various aspects of the geodetic and geophysical investigation and observation techniques. It includes material from the Arctic and Antarctica, as well as covering work from both temporary and permanent observatories.
On the effect of ionospheric delay on geodetic relative GPS positioning
Georgiadou, P.Y.; Kleusberg, A.
1988-01-01
Uncorrected ionospheric delay is one of the factors limiting the accuracy in geodetic relative positioning with single frequency Global Positioning System (GPS) carrier phase observations. Dual frequency measurements can be combined to eliminate the ionospheric delay in the observations. A
A comparative study for the estimation of geodetic point velocity by ...
Indian Academy of Sciences (India)
Geodetic point velocity; artificial neural networks; back propagation; radial basis function; Kriging. J. Earth Syst. Sci. ...... The employment of BPANN is an alternative tool to KRIG for .... Computational Intelligence and Multimedia Applications.
The Importance of Geodetically Controlled Data Sets: THEMIS Controlled Mosaics of Mars, a Case Study
Fergason, R. L.; Weller, L.
2018-04-01
Accurate image registration is necessary to answer questions that are key to addressing fundamental questions about our universe. To provide such a foundational product for Mars, we have geodetically controlled and mosaicked THEMIS IR images.
International Nuclear Information System (INIS)
Wildermuth, K.; Tang, Y.C.
1977-01-01
The purpose of this monograph is to describe a microscopic nuclear theory which can be used to consider all low-energy nuclear phenomena from a unified viewpoint. In this theory, the Pauli principle is completely taken into account and translationally invariant wave functions are always employed. It can be utilized to study reactions initiated not only by nucleons but also by arbitrary composite particles
Three-dimensional stochastic adjustment of volcano geodetic network in Arenal volcano, Costa Rica
Muller, C.; van der Laat, R.; Cattin, P.-H.; Del Potro, R.
2009-04-01
Volcano geodetic networks are a key instrument to understanding magmatic processes and, thus, forecasting potentially hazardous activity. These networks are extensively used on volcanoes worldwide and generally comprise a number of different traditional and modern geodetic surveying techniques such as levelling, distances, triangulation and GNSS. However, in most cases, data from the different methodologies are surveyed, adjusted and analysed independently. Experience shows that the problem with this procedure is the mismatch between the excellent correlation of position values within a single technique and the low cross-correlation of such values within different techniques or when the same network is surveyed shortly after using the same technique. Moreover one different independent network for each geodetic surveying technique strongly increase logistics and thus the cost of each measurement campaign. It is therefore important to develop geodetic networks which combine the different geodetic surveying technique, and to adjust geodetic data together in order to better quantify the uncertainties associated to the measured displacements. In order to overcome the lack of inter-methodology data integration, the Geomatic Institute of the University of Applied Sciences of Western Switzerland (HEIG-VD) has developed a methodology which uses a 3D stochastic adjustment software of redundant geodetic networks, TRINET+. The methodology consists of using each geodetic measurement technique for its strengths relative to other methodologies. Also, the combination of the measurements in a single network allows more cost-effective surveying. The geodetic data are thereafter adjusted and analysed in the same referential frame. The adjustment methodology is based on the least mean square method and links the data with the geometry. Trinet+ also allows to run a priori simulations of the network, hence testing the quality and resolution to be expected for a determined network even
Geodetic determinations for the NuMI project at Fermilab
International Nuclear Information System (INIS)
Bocean, V.
1999-01-01
As a part of the Neutrinos at the Main Injector (NuMI) project, the MINOS (Main Injector Neutrino Oscillation Search) experiment will search for neutrino mass by looking for neutrino oscillations. The project plans to direct a beam of muon neutrinos from the Main Injector towards both nearby and far-off detectors capable of counting all three types of neutrinos. The beam will travel 735 km through the Earth towards a remote iron mine in northern Minnesota where, 710 m below surface, a massive 5400 metric tons detector will be built. For the neutrino energy spectrum physics test to work properly, the primary proton beam must be within ± 12 m from its ideal position at Soudan, MN, corresponding to ± 1.63 x 10-5 radians, i.e. 3.4 arc-seconds. Achieving this tolerance requires a rather exact knowledge of the geometry of the beam, expressed in terms of the azimuth and the slope of the vector joining the two sites. This paper summarizes the concepts, the methodology, the implementation, and the results of the geodetic surveying efforts made up to date for determining the absolute positions of the Fermilab and the Soudan underground mine sites, from which the beam orientation parameters are computed. (author)
Thin-plate spline quadrature of geodetic integrals
Vangysen, Herman
1989-01-01
Thin-plate spline functions (known for their flexibility and fidelity in representing experimental data) are especially well-suited for the numerical integration of geodetic integrals in the area where the integration is most sensitive to the data, i.e., in the immediate vicinity of the evaluation point. Spline quadrature rules are derived for the contribution of a circular innermost zone to Stoke's formula, to the formulae of Vening Meinesz, and to the recursively evaluated operator L(n) in the analytical continuation solution of Molodensky's problem. These rules are exact for interpolating thin-plate splines. In cases where the integration data are distributed irregularly, a system of linear equations needs to be solved for the quadrature coefficients. Formulae are given for the terms appearing in these equations. In case the data are regularly distributed, the coefficients may be determined once-and-for-all. Examples are given of some fixed-point rules. With such rules successive evaluation, within a circular disk, of the terms in Molodensky's series becomes relatively easy. The spline quadrature technique presented complements other techniques such as ring integration for intermediate integration zones.
Azimuth selection for sea level measurements using geodetic GPS receivers
Wang, Xiaolei; Zhang, Qin; Zhang, Shuangcheng
2018-03-01
Based on analysis of Global Positioning System (GPS) multipath signals recorded by a geodetic GPS receiver, GPS Reflectometry (GPS-R) has demonstrated unique advantages in relation to sea level monitoring. Founded on multipath reflectometry theory, sea level changes can be measured by GPS-R through spectral analysis of recorded signal-to-noise ratio data. However, prior to estimating multipath parameters, it is necessary to define azimuth and elevation angle mask to ensure the reflecting zones are on water. Here, a method is presented to address azimuth selection, a topic currently under active development in the field of GPS-R. Data from three test sites: the Kachemak Bay GPS site PBAY in Alaska (USA), Friday Harbor GPS site SC02 in the San Juan Islands (USA), and Brest Harbor GPS site BRST in Brest (France) are analyzed. These sites are located in different multipath environments, from a rural coastal area to a busy harbor, and they experience different tidal ranges. Estimates by the GPS tide gauges at azimuths selected by the presented method are compared with measurements from physical tide gauges and acceptable correspondence found for all three sites.
Earth rotation excitation mechanisms derived from geodetic space observations
Göttl, F.; Schmidt, M.
2009-04-01
Earth rotation variations are caused by mass displacements and motions in the subsystems of the Earth. Via the satellite Gravity and Climate Experiment (GRACE) gravity field variations can be identified which are caused by mass redistribution in the Earth system. Therefore time variable gravity field models (GFZ RL04, CSR RL04, JPL RL04, ITG-Grace03, GRGS, ...) can be used to derive different impacts on Earth rotation. Furthermore satellite altimetry provides accurate information on sea level anomalies (AVISO, DGFI) which are caused by mass and volume changes of seawater. Since Earth rotation is solely affected by mass variations and motions the volume (steric) effect has to be reduced from the altimetric observations in order to infer oceanic contributions to Earth rotation variations. Therefore the steric effect is estimated from physical ocean parameters such as temperature and salinity changes in the oceans (WOA05, Ishii). In this study specific individual geophysical contributions to Earth rotation variations are identified by means of a multitude of accurate geodetic space observations in combination with a realistic error propagation. It will be shown that due to adjustment of altimetric and/or gravimetric solutions the results for polar motion excitations can be improved.
STRUCTURAL MONITORING WITH GEODETIC SURVEY OF QUADRIFOGLIO CONDOMINIUM (LECCE
Directory of Open Access Journals (Sweden)
D. Costantino
2014-01-01
Full Text Available Monitoring buildings for moving elements has been always a problem of great importance for their conservation and preservation, as well as for risk mitigation. In particular, topographic surveying allows, through the use of the principles and instruments of the geodetic survey, to control moving points which have been identified and measured. In this study case, twelve survey campaigns were done for monitoring a building located in the city of Lecce. The condominium was built five years ago on an old quarry filled with debris to allow construction. Later in time, obviously, cracks started to appear on walls within the property, and for this legal actions were taken. The survey schema adopted has been that of triangulation/trilateration, from two vertices with known coordinates. With this methodologies four cornerstones have been identified, established with forced centering on pillars with anchor plates, connected to same number of framework points, considered stable. From these, 23 control points located on the structure with rotating prisms anchored at the same manner have been surveyed. The elaboration has been carried out by generating redundancy of the measures and compensating the values with least mean squares. The results obtained by the activity of survey and elaboration have confirmed the existence of ongoing phenomena. The causes that have generated the phenomenon have been, subsequently, investigated and have been considered attributable to the existence of a sewer pipeline and a water pipeline not properly put in place and consequently broke down due to the geological characteristics of the site.
GeoSEA: Geodetic Earthquake Observatory on the Seafloor
Kopp, Heidrun; Lange, Dietrich; Flueh, Ernst R.; Petersen, Florian; Behrmann, Jan-Hinrich; Devey, Colin
2014-05-01
Space geodetic observations of crustal deformation have contributed greatly to our understanding of plate tectonic processes in general, and plate subduction in particular. Measurements of interseismic strain have documented the active accumulation of strain, and subsequent strain release during earthquakes. However, techniques such as GPS cannot be applied below the water surface because the electromagnetic energy is strongly attenuated in the water column. Evidence suggests that much of the elastic strain build up and release (and particularly that responsible for both tsunami generation and giant earthquakes) occurs offshore. To quantify strain accumulation and assess the resultant hazard potential we urgently need systems to resolve seafloor crustal deformation. Here we report on first results of sea trials of a newly implemented seafloor geodesy array. The GeoSEA (Geodetic Earthquake Observatory on the Seafloor) array consists of a seafloor transponder network comprising 35 units and a wave glider acting as a surface unit (GeoSURF) to ensure satellite correspondence, data transfer and monitor system health. Seafloor displacement occurs in the horizontal (x,y) and vertical direction (z). The vertical displacement is measured by monitoring pressure variations at the seafloor. Horizontal seafloor displacement can be measured either using an acoustic/GPS combination to provide absolute positioning (requiring a suitably equipped vessel to perform repeated cruises to provide the GPS fixes) or by long-term acoustic telemetry between different beacons fixed on the seafloor to determine relative distances by using the travel time observations to each other, which is the technique tested during our short sea trials. For horizontal direct path measurements, the system utilizes acoustic ranging techniques with a ranging precision better than 15 mm and long term stability over 2 km distances. Vertical motion is obtained from pressure gauges. Integrated inclinometers
Unified approach to dense matter
International Nuclear Information System (INIS)
Park, Byung-Yoon; Lee, Hee-Jung; Vento, Vicente; Kim, Joon-Il; Min, Dong-Pil; Rho, Mannque
2005-01-01
We apply the Skyrme model to dense hadronic matter, which provides a unified approach to high density, valid in the large N c limit. In our picture, dense hadronic matter is described by the classical soliton configuration with minimum energy for the given baryon number density. By incorporating the meson fluctuations on such ground state we obtain an effective Lagrangian for meson dynamics in a dense medium. Our starting point has been the Skyrme model defined in terms of pions, thereafter we have extended and improved the model by incorporating other degrees of freedom such as dilaton, kaons and vector mesons
Einstein's theory of unified fields
Tonnelat, Marie Antoinette
2014-01-01
First published in1966, here is presented a comprehensive overview of one of the most elusive scientific speculations by the pre-eminent genius of the 20th century. The theory is viewed by some scientists with deep suspicion, by others with optimism, but all agree that it represents an extreme challenge. As the author herself affirms, this work is not intended to be a complete treatise or 'didactic exposition' of the theory of unified fields, but rather a tool for further study, both by students and professional physicists. Dealing with all the major areas of research whic
Comparison of direct and geodetic mass balances on a multi-annual time scale
Directory of Open Access Journals (Sweden)
A. Fischer
2011-02-01
Full Text Available The geodetic mass balances of six Austrian glaciers over 19 periods between 1953 and 2006 are compared to the direct mass balances over the same periods. For two glaciers, Hintereisferner and Kesselwandferner, case studies showing possible reasons for discrepancies between the geodetic and the direct mass balance are presented. The mean annual geodetic mass balance for all periods is −0.5 m w.e. a^{−1}, the mean annual direct mass balance −0.4 m w.e. a^{−1}. The mean cumulative difference is −0.6 m w.e., the minimum −7.3 m w.e., and the maximum 5.6 m w.e. The accuracy of geodetic mass balance may depend on the accuracy of the DEMs, which ranges from 2 m w.e. for photogrammetric data to 0.02 m w.e. for airborne laser scanning (LiDAR data. Basal melt, seasonal snow cover, and density changes of the surface layer also contribute up to 0.7 m w.e. to the difference between the two methods over the investigated period of 10 yr. On Hintereisferner, the fraction of area covered by snow or firn has been changing within 1953–2006. The accumulation area is not identical with the firn area, and both are not coincident with areas of volume gain. Longer periods between the acquisition of the DEMs do not necessarily result in a higher accuracy of the geodetic mass balance. Trends in the difference between the direct and the geodetic data vary from glacier to glacier and can differ systematically for specific glaciers under specific types of climate forcing. Ultimately, geodetic and direct mass balance data are complementary, and great care must be taken when attempting to combine them.
The impacts of source structure on geodetic parameters demonstrated by the radio source 3C371
Xu, Ming H.; Heinkelmann, Robert; Anderson, James M.; Mora-Diaz, Julian; Karbon, Maria; Schuh, Harald; Wang, Guang L.
2017-07-01
Closure quantities measured by very-long-baseline interferometry (VLBI) observations are independent of instrumental and propagation instabilities and antenna gain factors, but are sensitive to source structure. A new method is proposed to calculate a structure index based on the median values of closure quantities rather than the brightness distribution of a source. The results are comparable to structure indices based on imaging observations at other epochs and demonstrate the flexibility of deriving structure indices from exactly the same observations as used for geodetic analysis and without imaging analysis. A three-component model for the structure of source 3C371 is developed by model-fitting closure phases. It provides a real case of tracing how the structure effect identified by closure phases in the same observations as the delay observables affects the geodetic analysis, and investigating which geodetic parameters are corrupted to what extent by the structure effect. Using the resulting structure correction based on the three-component model of source 3C371, two solutions, with and without correcting the structure effect, are made. With corrections, the overall rms of this source is reduced by 1 ps, and the impacts of the structure effect introduced by this single source are up to 1.4 mm on station positions and up to 4.4 microarcseconds on Earth orientation parameters. This study is considered as a starting point for handling the source structure effect on geodetic VLBI from geodetic sessions themselves.
Operational production of Geodetic Excitation Functions from EOP estimated values at ASI-CGS
Sciarretta, C.; Luceri, V.; Bianco, G.
2009-04-01
ASI-CGS is routinely providing geodetic excitation functions from its own estimated EOP values (at present SLR and VLBI; the current use of GPS EOP's is also planned as soon as this product will be fully operational) on the ASI geodetic web site (http://geodaf.mt.asi.it). This product has been generated and monitored (for ASI internal use only) in a long pre-operational phase (more than two years), including validation and testing. The daily geodetic excitation functions are now weekly updated along with the operational ASI SLR and VLBI EOP solutions and compared, whenever possible, with the atmospheric excitation functions available at the IERS SBAAM, under the IB and not-IB assumption, including the "wind" term. The work will present the available estimated geodetic function time series and its comparison with the relevant atmospheric excitation functions, deriving quantitative indicators on the quality of the estimates. The similarities as well as the discrepancies among the atmospheric and geodetic series will be analysed and commented, evaluating in particular the degree of correlation among the two estimated time series and the likelihood of a linear dependence hypothesis.
Large earthquake rates from geologic, geodetic, and seismological perspectives
Jackson, D. D.
2017-12-01
Earthquake rate and recurrence information comes primarily from geology, geodesy, and seismology. Geology gives the longest temporal perspective, but it reveals only surface deformation, relatable to earthquakes only with many assumptions. Geodesy is also limited to surface observations, but it detects evidence of the processes leading to earthquakes, again subject to important assumptions. Seismology reveals actual earthquakes, but its history is too short to capture important properties of very large ones. Unfortunately, the ranges of these observation types barely overlap, so that integrating them into a consistent picture adequate to infer future prospects requires a great deal of trust. Perhaps the most important boundary is the temporal one at the beginning of the instrumental seismic era, about a century ago. We have virtually no seismological or geodetic information on large earthquakes before then, and little geological information after. Virtually all-modern forecasts of large earthquakes assume some form of equivalence between tectonic- and seismic moment rates as functions of location, time, and magnitude threshold. That assumption links geology, geodesy, and seismology, but it invokes a host of other assumptions and incurs very significant uncertainties. Questions include temporal behavior of seismic and tectonic moment rates; shape of the earthquake magnitude distribution; upper magnitude limit; scaling between rupture length, width, and displacement; depth dependence of stress coupling; value of crustal rigidity; and relation between faults at depth and their surface fault traces, to name just a few. In this report I'll estimate the quantitative implications for estimating large earthquake rate. Global studies like the GEAR1 project suggest that surface deformation from geology and geodesy best show the geography of very large, rare earthquakes in the long term, while seismological observations of small earthquakes best forecasts moderate earthquakes
Geodetic constraints on continental rifting along the Red Sea
Reilinger, R.; McClusky, S.; Arrajehi, A.; Mahmoud, S.; Rayan, A.; Ghebreab, W.; Ogubazghi, G.; Al-Aydrus, A.
2006-12-01
We are using the Global Positioning System (GPS) to monitor and quantify patterns and rates of tectonic and magmatic deformation associated with active rifting of the continental lithosphere and the transition to sea floor spreading in the Red Sea. Broad-scale motions of the Nubian and Arabian plates indicate coherent plate motion with internal deformation below the current resolution of our measurements (~ 1-2 mm/yr). The GPS-determined Euler vector for Arabia-Nubia is indistinguishable from the geologic Euler vector determined from marine magnetic anomalies, and Arabia-Eurasia relative motion from GPS is equal within uncertainties to relative motion determined from plate reconstructions, suggesting that Arabia plate motion has remained constant (±10%) during at least the past ~10 Ma. The approximate agreement between broad-scale GPS rates of extension (i.e., determined from relative plate motions) and those determined from magnetic anomalies along the Red Sea rift implies that spreading in the central Red Sea is primarily confined to the central rift (±10-20%). Extension appears to be more broadly distributed in the N Red Sea and Gulf of Suez where comparisons with geologic data also indicate a relatively recent (between 500 and 125 kyr BP) change in the motion of the Sinai block that is distinct from both Nubia and Arabia. In the southern Red Sea, GPS results are beginning to define the motion of the "Danakil micro-plate". We investigate and report on a model involving CCW rotation of the Danakil micro-plate relative to Nubia and magmatic inflation below the Afar Triple Junction that is consistent with available geodetic constraints. Running the model back in time suggests that the Danakil micro-plate has been an integral part of rifting/triple junction processes throughout the history of separation of the Arabian and Nubian plates. On the scale of Nubia-Arabia-Eurasia plate interactions, we show that new area formed at spreading centers roughly equals that
Regional Crustal Deformation and Lithosphere Thickness Observed with Geodetic Techniques
Vermeer, M.; Poutanen, M.; Kollo, K.; Koivula, H.; Ahola, J.
2009-04-01
The solid Earth, including the lithosphere, interacts in many ways with other components of the Earth system, oceans, atmosphere and climate. Geodesy is a key provider of data needed for global and environmental research. Geodesy provides methods and accurate measurements of contemporary deformation, sea level and gravity change. The importance of the decades-long stability and availability of reference frames must be stressed for such studies. In the future, the need to accurately monitor 3-D crustal motions will grow, both together with increasingly precise GNSS (Global Navigation Satellite System) positioning, demands for better follow-up of global change, and local needs for crustal motions, especially in coastal areas. These demands cannot yet be satisfied. The project described here is a part of a larger entity: Upper Mantle Dynamics and Quaternary Climate in Cratonic Areas, DynaQlim, an International Lithosphere Project (ILP) -sponsored initiative. The aims of DynaQlim are to understand the relations between upper mantle dynamics, mantle composition, physical properties, temperature and rheology, to study the postglacial uplift and ice thickness models, sea level change and isostatic response, Quaternary climate variations and Weichselian (Laurentian and other) glaciations during the late Quaternary. We aim at studying various aspects of lithospheric motion within the Finnish and Fennoscandian area, but within a global perspective, by the newest geodetic techniques in a multidisciplinary setting. The studies involve observations of three-dimensional motions and gravity change in a multidisciplinary context on a range of spatial scales: the whole of Fennoscandia, Finland, a regional test area of Satakunta, and the local test site Olkiluoto. Objectives of the research include improving our insight into the 3-D motion of a thick lithosphere, and into the gravity effect of the uplift, using novel approaches; improving the kinematic 3-D models in the
Monitoring of Volcanic Activity by Sub-mm Geodetic Analyses
Miura, S.; Mare, Y.; Ichiki, M.; Demachi, T.; Tachibana, K.; Nishimura, T.
2017-12-01
Volcanic earthquakes have been occurring beneath Zao volcano in northern Honshu, Japan since 2013, following the increase of deep low frequency earthquakes from 2012. On account of a burst of seismicity initiated in April 2015, the JMA announced a warning of eruption, however, the seismicity gradually decreased for the next two months and the warning was canceled in June. In the same time period, minor expansive deformation was observed by GNSS. Small earthquakes are still occurring, and low-freq. earthquakes (LPE) occur sometimes accompanied by static tilt changes. In this study, we try to extract the sub-mm displacements from the LPE waveforms observed by broadband seismometers (BBS) and utilize them for geodetic inversion to monitor volcanic activities. Thun et al. (2015, 2016) devised an efficient method using a running median filter (RMF) to remove LP noises, which contaminate displacement waveforms. They demonstrated the reproducibility of the waveforms corresponding to the experimentally given sub-mm displacements in the laboratory. They also apply the method to the field LPE data obtained from several volcanoes to show static displacements. The procedure is outlined as follows: (1) Unfiltered removal of the instrument response, (2) LP noise estimate by LPF with a corner frequency of 5/M, where M (seconds) is the time window of the RMF and should be at least three times the length of the rise time. (3) Subtract the noise estimated from step (2). (4) Integrate to obtain displacement waveforms. We apply the method to the BBS waveform at a distance of about 1.5 km ESE from the summit crater of Zao Volcano associated with a LPE on April 1, 2017. Assuming the time window M as 300 seconds, we successfully obtained the displacement history: taking the rise time of about 2 minutes, the site was gradually uplifted with the amount of about 50-60 µm and then subsided with HF displacements in the next 2 minutes resulting about 20-30 µm static upheaval. Comparing the
Geodetic data support trapping of ethane in Titan's polar crust
Sotin, Christophe; Rambaux, Nicolas
2016-04-01
Titan's surface is characterized by polar depressions that strongly influence interpretations of the gravity data. This study investigates several geodynamical models that can explain these depressions. For each model, the values of the three moments of inertia are computed numerically by discretizing the interior in spherical coordinates. The study shows that a Pratt model where the polar subsurface is made of ethane clathrates can explain the polar depression, the abrupt jump in altitude at about 60 degrees latitude, and the values of the degree 2 gravity coefficients. This model, proposed by Choukroun and Sotin [1], is based on the stability of ethane clathrate hydrates relative to methane clathrate hydrates. In addition to fitting the geodetic data, it explains the absence of ethane in Titan's atmosphere although ethane is the main product of the photolysis of methane. Other geophysical models based on latitudinal variations in the tidal heating production or in the heat flux at the base of the icy crust do not provide such a good match to the gravity and topographic observations. The ethane-clathrate model predicts that all the ethane produced by photolysis of methane at the present rate during the last billion years could be stored in the polar subsurface. It is consistent with the age of Titan's surface and that of Titan's atmospheric methane inferred from geological and geochemical observations by the Cassini/Huygens mission. The present study also emphasizes the role of mass anomalies on the interpretation of the degree 2 gravity coefficients. It shows that for Titan, a slow rotator, the values of the two equatorial moments of inertia (MoI) are largely affected by the polar depressions whereas the value of polar MoI is not. Therefore, as pointed out by previous calculations [2], calculating the moment of inertia (MoI) factor from the value of J2 could lead to major errors. This is not the case for our preferred Titan's model for which the negative polar
Geodetic infrastructure at the Barcelona harbour for sea level monitoring
Martinez-Benjamin, Juan Jose; Gili, Josep; Lopez, Rogelio; Tapia, Ana; Pros, Francesc; Palau, Vicenc; Perez, Begona
2015-04-01
The presentation is directed to the description of the actual geodetic infrastructure of Barcelona harbour with three tide gauges of different technologies for sea level determination and contribution to regional sea level rise and understanding past and present sea level rise in the Barcelona harbour. It is intended that the overall system will constitute a CGPS Station of the ESEAS (European Sea Level) and TIGA (GPS Tide Gauge Benchmark Monitoring) networks. At Barcelona harbour there is a MIROS radar tide gauge belonging to Puertos del Estado (Spanish Harbours).The radar sensor is over the water surface, on a L-shaped structure which elevates it a few meters above the quay shelf. 1-min data are transmitted to the ENAGAS Control Center by cable and then sent each 1 min to Puertos del Estado by e-mail. The information includes wave forescast (mean period, significant wave height, sea level, etc.This sensor also measures agitation and sends wave parameters each 20 min. There is a GPS station Leica Geosystems GRX1200 GG Pro and antenna AX 1202 GG. The Control Tower of the Port of Barcelona is situated in the North dike of the so-called Energy Pier in the Barcelona harbor (Spain). This tower has different kind of antennas for navigation monitoring and a GNSS permanent station. As the tower is founded in reclaimed land, and because its metallic structure, the 50 m building is subjected to diverse movements, including periodic fluctuations due to temperature changes. In this contribution the 2009, 2011, 2012, 2013 and 2014 the necessary monitoring campaigns are described. In the framework of a Spanish Space Project, the instrumentation of sea level measurements has been improved by providing the Barcelona site with a radar tide gauge Datamar 2000C from Geonica S.L. in June 2014 near an acoustic tide gauge from the Barcelona Harbour installed in 2013. Precision levelling has been made several times in the last two years because the tower is founded in reclaimed land and
Kodet, J.; Schreiber, K. U.; Eckl, J.; Plötz, C.; Mähler, S.; Schüler, T.; Klügel, T.; Riepl, S.
2018-01-01
The quality of the links between the different space geodetic techniques (VLBI, SLR, GNSS and DORIS) is still one of the major limiting factors for the realization of a unique global terrestrial reference frame that is accurate enough to allow the monitoring of the Earth system, i.e., of processes like sea level change, postglacial rebound and silent earthquakes. According to the specifications of the global geodetic observing system of the International Association of Geodesy, such a reference frame should be accurate to 1 mm over decades, with rates of change stable at the level of 0.1 mm/year. The deficiencies arise from inaccurate or incomplete local ties at many fundamental sites as well as from systematic instrumental biases in the individual space geodetic techniques. Frequently repeated surveys, the continuous monitoring of antenna heights and the geometrical mount stability (Lösler et al. in J Geod 90:467-486, 2016. https://doi.org/10.1007/s00190-016-0887-8) have not provided evidence for insufficient antenna stability. Therefore, we have investigated variations in the respective system delays caused by electronic circuits, which is not adequately captured by the calibration process, either because of subtle differences in the circuitry between geodetic measurement and calibration, high temporal variability or because of lacking resolving bandwidth. The measured system delay variations in the electric chain of both VLBI- and SLR systems reach the order of 100 ps, which is equivalent to 3 cm of path length. Most of this variability is usually removed by the calibrations but by far not all. This paper focuses on the development of new technologies and procedures for co-located geodetic instrumentation in order to identify and remove systematic measurement biases within and between the individual measurement techniques. A closed-loop optical time and frequency distribution system and a common inter-technique reference target provide the possibility to remove
Towards a Unified Programming Language
DEFF Research Database (Denmark)
Madsen, Ole Lehrmann
2000-01-01
The goal of research in programming languages should be to develop languages that integrates the best of concepts and constructs from the various programming paradigms. We do not argue for a multi-paradigm language, where the programmer alternates between the different paradigms/styles. Instead, we...... find that the languages of the future should integrate the best available concepts and constructs in such a way that the programmer does not think of multiple paradigms when using a given language. In this paper, we describe to what extent the BETA language has been successful in obtaining a unified...... style and where more research is needed. In addition to traditional paradigms such as object-oriented-, imperative-functional- and logic programming, we also discuss concurrent programming and prototype-based programming. We discuss language features such as the BETA pattern construct, virtual...
A unified plant information network
International Nuclear Information System (INIS)
Niederauer, G.F.
1986-01-01
Technology is bringing power plants fully into the age of computerization. Microcomputers, data base managers, networking, and friendly, expert software are principal technology factors. Monitoring will improve, and the number and power of computers is increasing. The huge information flow will cause computers to be integrated into a communication network. The total plant operating triangle includes process, engineering, and management systems. The total network will integrate all of these into a Total Unified Plant Information Network (TUPIN). Software will take the type of information beyond monitored data. Analysis will improve through direct access to logical, physical, and procedural models by end users. Information management will improve through widespread use of hierarchical, relational, and expert data base managers. Expert systems will aid in diagnostics and interpretation. The goal is to automate plant operations to enhance safety and performance and to reduce cost by making both the plants and the personnel more expert
Cosmology and unified gauge theory
Oraifeartaigh, L.
1981-09-01
Theoretical points in common between cosmology and unified gauge theory (UGT) are reviewed, with attention given to areas of one which have proven useful for the other. The underlying principles for both theoretical frameworks are described, noting the differences in scale, i.e., 10 to the 25th cm in cosmology and 10 to the -15th cm for UGT. Cosmology has produced bounds on the number of existing neutrino species, and also on the mass of neutrinos, two factors of interest in particle physics. Electrons, protons, and neutrinos, having been spawned from the same massive leptons, each composed of three quarks, have been predicted to be present in equal numbers in the Universe by UGT, in line with necessities of cosmology. The Grand UGT also suggests specific time scales for proton decay, thus accounting for the observed baryon assymmetry.
Unifying physical concepts of reality
Energy Technology Data Exchange (ETDEWEB)
Gilbert, T.L.
1983-08-01
Physics may be characterized as the science of matter and energy. It anchors the two ends of the frontiers of science: the frontier of the very small and the frontier of the very large. All of the phenomena that we observe and study at the frontiers of science - all external experiences - are manifestations of matter and energy. One may, therefore, use physics to exemplify both the diversity and unity of science. This theme will be developed in two separate examples: first by sketching, very briefly, the historical origins of frontiers of the very small and very large and the converging unity of these two frontiers; and then by describing certain unifying concepts that play a central role in physics and provide a framework for relating developments in different sciences.
Phenomenology of unified gauge theories
International Nuclear Information System (INIS)
Ellis, J.
1983-01-01
Part I of these lectures treats the standard Glashow-Weinberg-Salam model of weak and electromagnetic interactions, discussing in turn its basic structure and weak neutral currents, charged currents, mixing angles and CP violation, and the phenomenology of weak vector and Higgs bosons. Part II of the lectures discusses the structure of theories of dynamical symmetry breaking such as technicolour, phenomenological consequences, frustrations and alternatives. The third part of these lectures offers the standard menu of grand unified theories (GUTs) of the strong, weak and electromagnetic interactions, including an hors d'oeuvre of constraints on the parameters of the standard model, a main course of baryon number violating processes, and desserts which violate lepton number and CP. The fourth and final part goes through different attempts to remedy the inadequacies of previous theories by invoking supersymmetry and reaching out towards gravitation. (orig./HSI)
Unifying physical concepts of reality
International Nuclear Information System (INIS)
Gilbert, T.L.
1983-01-01
Physics may be characterized as the science of matter and energy. It anchors the two ends of the frontiers of science: the frontier of the very small and the frontier of the very large. All of the phenomena that we observe and study at the frontiers of science - all external experiences - are manifestations of matter and energy. One may, therefore, use physics to exemplify both the diversity and unity of science. This theme will be developed in two separate examples: first by sketching, very briefly, the historical origins of frontiers of the very small and very large and the converging unity of these two frontiers; and then by describing certain unifying concepts that play a central role in physics and provide a framework for relating developments in different sciences
Unified gauge theories with spontaneous symmetry breaking
International Nuclear Information System (INIS)
MacDowell, S.W.
1975-01-01
Unified gauge theories with spontaneous symmetry breaking are studied with a view to renormalize quantum field theory. Georgi-Glashow and Weinberg-Salam models to unify weak and electromagnetic interactions are discussed in detail. Gauge theories of strong interactions are also considered [pt
A unifying philosophy of governance
Directory of Open Access Journals (Sweden)
Sankarshan Acharya
2012-09-01
Full Text Available Bertrand Russell won Nobel Prize for arguing that science has triumphed over religion. Since religions are based on god, Russell’s argument implies that science has triumphed over both religion and god. But neither Russell nor anyone else has ever defined religion and god, rationally. The assertion about triumph of science (which is founded on rationality over concepts such as religion and god (which are not defined rationally or scientifically in the extant literature cannot be rational. This paper offers a novel rational philosophical foundation for the concepts of god, religion and science in which the claim that science triumphs over religion is redundant. This paper also presents substantial new insights about epistemic truths to help resolve current problems facing humanity like financial moral hazard and terrorism which have unnerved nations worldwide. The humanity now begs to answer a fundamental question of how we can govern ourselves. This paper offers a coherent set of credible answers. In particular, it offers a coherent unified philosophy about how humans have universally formed beliefs to govern themselves and how this philosophy could help resolve current problems. The universal rendering of beliefs articulated here subsumes the extant characterization of probability beliefs in mathematics, science, engineering, economics, religion and philosophy. The universal beliefs so articulated in this paper obviate the currently prevalent philosophical conflicts between religion and science or between theism and atheism and paves the way for optimal governance for prosperity amid stability. This philosophy also offers a rational characterization of the spiritual notion of Nirvana or salvation of the soul and the notion of epistemic truth. The unifying philosophy can help humanity achieve unity, stability and prosperity, sans financial moral hazard, antagonism, wars, nuclear proliferation, global warming and atmospheric pollution.
Toward a Unified AGN Structure
Kazanas, Demosthenes; Fukumura, Keigo; Shrader, Chris; Behar, Ehud; Contopoulosa, Ioannis
2012-01-01
We present a unified model for the structure and appearance of accretion powered sources across their entire luminosity range from galactic X-ray binaries (XRB) to luminous quasars, with emphasis on AG N and their phenomenology. Central to this model is the notion of MHD winds launched by the accretion disks that power these objects. These winds provide the matter that manifests as blueshifted absorption features in the UV and X-ray spectra of a large fraction of these sources; furthermore, their density distribution in the poloidal plane determines their "appearance" (i.e. the column and velocity structure of these absorption features and the obscuration of the continuum source) as a function of the observer inclination angle (a feature to which INTEGRAL has made significant contributions). This work focuses on just the broadest characteristics of these objects; nonetheless, it provides scaling laws that allow one to reproduce within this model the properties of objects extending in luminosity from luminous quasars to XRBs. Our general conclusion is that the AGN phenomenology can be accounted for in terms of three parameters: The wind maSS flux in units of the Eddington value, m(dot), the observers' inclination angle Theta and the logarithmic slope between the 0/UV and X-ray fluxes alpha(sub ox); however because of a correlation between alpha(sub ox) and UV luminosity the number of significant parameters is two. The AGN correlations implied by this model appear to extend to and consistent with the XRB phenomenology, suggesting the presence of a truly unified underlying structure for accretion powered sources.
First-order design of geodetic networks using the simulated annealing method
Berné, J. L.; Baselga, S.
2004-09-01
The general problem of the optimal design for a geodetic network subject to any extrinsic factors, namely the first-order design problem, can be dealt with as a numeric optimization problem. The classic theory of this problem and the optimization methods are revised. Then the innovative use of the simulated annealing method, which has been successfully applied in other fields, is presented for this classical geodetic problem. This method, belonging to iterative heuristic techniques in operational research, uses a thermodynamical analogy to crystalline networks to offer a solution that converges probabilistically to the global optimum. Basic formulation and some examples are studied.
Seagrass from Unified Florida Reef Tract Map (NODC Accession 0123059)
National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is a subset of the Unified Map representing Seagrass areas. Version 1.1 - December 2013. The Unified Florida Reef Tract Map (Unified Reef Map) provides...
Geodetic antenna calibration test in the Antarctic environment
Grejner-Brzezinska, A.; Vazquez, E.; Hothem, L.
2006-01-01
TransAntarctic Mountain DEFormation (TAMDEF) Monitoring Network is the NSF-sponsored OSU and USGS project, aimed at measuring crustal motion in the Transantarctic Mountains of Victoria Land using GPS carrier phase measurements. Station monumentation, antenna mounts, antenna types, and data processing strategies were optimized to achieve mm-level estimates for the rates of motion. These data contributes also to regional Antarctic frame definition. Significant amount of data collected over several years allow the investigation of unique aspects of GPS geodesy in Antarctica, to determine how the error spectrum compares to the mid-latitude regions, and to identify the optimum measurement and data processing schemes for Antarctic conditions, in order to test the predicted rates of motion (mm-level w.r.t. time). The data collection for the TAMDEF project was initiated in 1996. The primary antenna used has been the Ashtech L1/L2 Dorne Margolin (D/M) choke ring. A few occupations involved the use of a Trimble D/M choke ring. The data were processed using the antenna calibration data available from the National Geodetic Survey (NGS). The recent developments in new antenna designs that are lighter in weight and lower in cost are being considered as a possible alternative to the bulkier and more expensive D/M choke ring design. In November 2003, in situ testing of three alternative models of L1/L2 antennas was conducted at a site located in the vicinity of McMurdo Station, Antarctica (S77.87, E166.56). The antenna models used in this test were: Ashtech D/M choke ring, Trimble D/M choke ring, Trimble Zephyr, and the NovAtel GPS-702. Two stations, spaced within 30 meters, were used in the test. Both had the characteristics similar to the stations of the TAMDEF network, i.e., the UNAVCO fixed-height, force-centered level mounts with a constant antenna offset were used, ensuring extreme stability of the antenna/ mount/pin set up. During each of the four 3-day test data collection
76 FR 43923 - Final Flood Elevation Determinations
2011-07-22
... Approximately 30 feet downstream of I-64 +22 *National Geodetic Vertical Datum. +North American Vertical Datum... Center Street. * National Geodetic Vertical Datum. + North American Vertical Datum. Depth in feet above... +864 upstream of Wallace Street. Moon and Hamilton County Drain......... At the Detention Area F +861...
A Product Line Enhanced Unified Process
DEFF Research Database (Denmark)
Zhang, Weishan; Kunz, Thomas
2006-01-01
The Unified Process facilitates reuse for a single system, but falls short handling multiple similar products. In this paper we present an enhanced Unified Process, called UPEPL, integrating the product line technology in order to alleviate this problem. In UPEPL, the product line related activit...... activities are added and could be conducted side by side with other classical UP activities. In this way both the advantages of Unified Process and software product lines could co-exist in UPEPL. We show how to use UPEPL with an industrial mobile device product line in our case study....
A Unified Grand Tour of Theoretical Physics
Lawrie, Ian D
2002-01-01
A unified account of the principles of theoretical physics, A Unified Grand Tour of Theoretical Physics, Second Edition stresses the inter-relationships between areas that are usually treated as independent. The profound unifying influence of geometrical ideas, the powerful formal similarities between statistical mechanics and quantum field theory, and the ubiquitous role of symmetries in determining the essential structure of physical theories are emphasized throughout.This second edition conducts a grand tour of the fundamental theories that shape our modern understanding of the physical wor
The unified theory of nuclear reactions
International Nuclear Information System (INIS)
Tobocman, W.
A unified nuclear reaction theory is a formalism for the scattering reactions of many-body nuclear systems which is capable of describing both direct interaction and compound nucleus formation processes. The Feshbach projection operator formalism is the original unified nuclear reaction theory. An alternative unified nuclear reaction theory called the X-matrix formalism is described. The X-matrix formalism is a generalization of the Brown-de Dominicis formalism. It does not require projection operators and is readly applied to rearrangement collisions
The impact of using jason-1 and cryosat-2 geodetic mission altimetry for gravity field modeling
DEFF Research Database (Denmark)
Andersen, Ole Baltazar; Jain, Maulik; Knudsen, Per
2016-01-01
Since the release of the Danish Technical University DTU10 global marine gravity field in 2010, the amount of geodetic mission altimetry data has nearly tripled. The Cryosat-2 satellite have provided data along its 369 day near repeat since 2010 and as of May 2012 the Jason-1 satellite has been o...
Geodynamical behavior of some active area in Egypt, as deduced from geodetic and gravity data
Issawy, E.; Mrlina, J.; Radwan, A.; Mahmoud, S.; Rayan, A.
2009-04-01
Temporal gravity variation in parallel with the space geodetic technique (GPS) had been started in Egypt for real campaigns in 1997. The geodetic networks around the High Dam, Aswan area was the first net to be measured. More than five measurement epochs were performed. The results had a considerable limit of coincidence between gravity and GPS observations. The trend of gravity changes indicated a positive stress and had the vertical displacement observed for leveling points. The lowest gravity changes along Kalabsha fault reflect extensional and/or strike component of the stress field. Also, the areas around Cairo (Greater Cairo) and due to the occurrence of an earthquake of 1992, such type of measurements were useful for monitoring the recent activity. The data of the geodetic network around Cairo after 5 campaigns showed that, the estimated horizontal velocities for almost all points are 5.5± mm/year in approximately NW-SE direction. The non-tidal changes can explain the dynamic process within the upper crust related to the development of local stress conditions. The trends of gravity changes are more or less coincident with that deduced from GPS deformation analysis and the occurrence of the main shocks in the area. In additions, in 2005 the geodetic network around the southern part of Sinai and the Gulf of Suez were established. One campaign of measurements had been performed and the gravity values were obtained.
Williamson, A.; Newman, A. V.
2017-12-01
Finite fault inversions utilizing multiple datasets have become commonplace for large earthquakes pending data availability. The mixture of geodetic datasets such as Global Navigational Satellite Systems (GNSS) and InSAR, seismic waveforms, and when applicable, tsunami waveforms from Deep-Ocean Assessment and Reporting of Tsunami (DART) gauges, provide slightly different observations that when incorporated together lead to a more robust model of fault slip distribution. The merging of different datasets is of particular importance along subduction zones where direct observations of seafloor deformation over the rupture area are extremely limited. Instead, instrumentation measures related ground motion from tens to hundreds of kilometers away. The distance from the event and dataset type can lead to a variable degree of resolution, affecting the ability to accurately model the spatial distribution of slip. This study analyzes the spatial resolution attained individually from geodetic and tsunami datasets as well as in a combined dataset. We constrain the importance of distance between estimated parameters and observed data and how that varies between land-based and open ocean datasets. Analysis focuses on accurately scaled subduction zone synthetic models as well as analysis of the relationship between slip and data in recent large subduction zone earthquakes. This study shows that seafloor deformation sensitive datasets, like open-ocean tsunami waveforms or seafloor geodetic instrumentation, can provide unique offshore resolution for understanding most large and particularly tsunamigenic megathrust earthquake activity. In most environments, we simply lack the capability to resolve static displacements using land-based geodetic observations.
Driver, J. M.
1982-01-01
Significant aberrations can occur in acquired images which, unless compensated on board the spacecraft, can seriously impair throughput and timeliness for typical Earth observation missions. Conceptual compensations options are advanced to enable acquisition of images with inherent geometric and geodetic accuracy. Research needs are identified which, when implemented, can provide inherently accurate images. Agressive pursuit of these research needs is recommended.
A unifying conceptual model of entrepreneurial management
DEFF Research Database (Denmark)
Senderovitz, Martin
This article offers a systematic analysis and synthesis of the area of entrepreneurial management. Through a presentation of two main perspectives on entrepreneurial management and a newly developed unifying conceptual entrepreneurial management model, the paper discusses a number of theoretical...
Unified data model for biological data
International Nuclear Information System (INIS)
Idrees, M.
2014-01-01
A data model empowers us to store, retrieve and manipulate data in a unified way. We consider the biological data consists of DNA (De-Oxyribonucleic Acid), RNA (Ribonucleic Acid) and protein structures. In our Bioinformatics Lab (Bioinformatics Lab, Alkhawarizmi Institute of Computer Science, University of Engineering and Technology, Lahore, Pakistan), we have already proposed two data models for DNA and protein structures individually. In this paper, we propose a unified data model by using the data models of TOS (Temporal Object Oriented System) after making some necessary modifications to this data model and our already proposed the two data models. This proposed unified data model can be used for the modeling and maintaining the biological data (i.e. DNA, RNA and protein structures), in a single unified way. (author)
76 FR 19893 - Unified Command Plan 2011
2011-04-08
... Plan 2011 Memorandum for the Secretary of Defense Pursuant to my authority as Commander in Chief, I hereby approve and direct the implementation of the revised Unified Command Plan. Consistent with title...
Development of unified gauge theories: retrospect
International Nuclear Information System (INIS)
Lee, B.W.
1977-01-01
The construction and development of unified gauge theory of weak, electromagnetic, and strong interactions is reviewed. The Weinberg and Lee contributions to this study are mainly considered as personal recollections
Unified universal quantum cloning machine and fidelities
Energy Technology Data Exchange (ETDEWEB)
Wang Yinan; Shi Handuo; Xiong Zhaoxi; Jing Li; Mu Liangzhu [School of Physics, Peking University, Beijing 100871 (China); Ren Xijun [School of Physics and Electronics, Henan University, Kaifeng 4750011 (China); Fan Heng [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)
2011-09-15
We present a unified universal quantum cloning machine, which combines several different existing universal cloning machines together, including the asymmetric case. In this unified framework, the identical pure states are projected equally into each copy initially constituted by input and one half of the maximally entangled states. We show explicitly that the output states of those universal cloning machines are the same. One importance of this unified cloning machine is that the cloning procession is always the symmetric projection, which reduces dramatically the difficulties for implementation. Also, it is found that this unified cloning machine can be directly modified to the general asymmetric case. Besides the global fidelity and the single-copy fidelity, we also present all possible arbitrary-copy fidelities.
Unified Approach in the DSS Development Process
Directory of Open Access Journals (Sweden)
2007-01-01
Full Text Available The structure of today's decision support environment become very complex due to new generation of Business Intelligence applications and technologies like Data Warehouse, OLAP (On Line Analytical Processing and Data Mining. In this respect DSS development process are not simple and needs an adequate methodology or framework able to manage different tools and platforms to achieve manager's requirements. The DSS development process must be view like a unified and iterative set of activities and operations. The new techniques based on Unified Process (UP methodology and UML (Unified Modeling Language it seems to be appropriate for DSS development using prototyping and RAD (Rapid Application Development techniques. In this paper we present a conceptual framework for development and integrate Decision Support Systems using Unified Process Methodology and UML.
Unified Chiral models of mesons and baryons
International Nuclear Information System (INIS)
Mendez-Galain, R.; Ripka, G.
1990-01-01
Unified Chiral models of mesons and baryons are presented. Emphasis is placed on the underlying quark structure of hadrons including the Skyrmion. The Nambu Jona-Lasinio model with vector mesons is discussed
Barnhart, W. D.; Briggs, R.
2015-12-01
Geodetic imaging techniques enable researchers to "see" details of fault rupture that cannot be captured by complementary tools such as seismology and field studies, thus providing increasingly detailed information about surface strain, slip kinematics, and how an earthquake may be transcribed into the geological record. For example, the recent Haiti, Sierra El Mayor, and Nepal earthquakes illustrate the fundamental role of geodetic observations in recording blind ruptures where purely geological and seismological studies provided incomplete views of rupture kinematics. Traditional earthquake hazard analyses typically rely on sparse paleoseismic observations and incomplete mapping, simple assumptions of slip kinematics from Andersonian faulting, and earthquake analogs to characterize the probabilities of forthcoming ruptures and the severity of ground accelerations. Spatially dense geodetic observations in turn help to identify where these prevailing assumptions regarding fault behavior break down and highlight new and unexpected kinematic slip behavior. Here, we focus on three key contributions of space geodetic observations to the analysis of co-seismic deformation: identifying near-surface co-seismic slip where no easily recognized fault rupture exists; discerning non-Andersonian faulting styles; and quantifying distributed, off-fault deformation. The 2013 Balochistan strike slip earthquake in Pakistan illuminates how space geodesy precisely images non-Andersonian behavior and off-fault deformation. Through analysis of high-resolution optical imagery and DEMs, evidence emerges that a single fault map slip as both a strike slip and dip slip fault across multiple seismic cycles. These observations likewise enable us to quantify on-fault deformation, which account for ~72% of the displacements in this earthquake. Nonetheless, the spatial distribution of on- and off-fault deformation in this event is highly spatially variable- a complicating factor for comparisons
Propagation of uncertainty by Monte Carlo simulations in case of basic geodetic computations
Directory of Open Access Journals (Sweden)
Wyszkowska Patrycja
2017-12-01
Full Text Available The determination of the accuracy of functions of measured or adjusted values may be a problem in geodetic computations. The general law of covariance propagation or in case of the uncorrelated observations the propagation of variance (or the Gaussian formula are commonly used for that purpose. That approach is theoretically justified for the linear functions. In case of the non-linear functions, the first-order Taylor series expansion is usually used but that solution is affected by the expansion error. The aim of the study is to determine the applicability of the general variance propagation law in case of the non-linear functions used in basic geodetic computations. The paper presents errors which are a result of negligence of the higher-order expressions and it determines the range of such simplification. The basis of that analysis is the comparison of the results obtained by the law of propagation of variance and the probabilistic approach, namely Monte Carlo simulations. Both methods are used to determine the accuracy of the following geodetic computations: the Cartesian coordinates of unknown point in the three-point resection problem, azimuths and distances of the Cartesian coordinates, height differences in the trigonometric and the geometric levelling. These simulations and the analysis of the results confirm the possibility of applying the general law of variance propagation in basic geodetic computations even if the functions are non-linear. The only condition is the accuracy of observations, which cannot be too low. Generally, this is not a problem with using present geodetic instruments.
Propagation of uncertainty by Monte Carlo simulations in case of basic geodetic computations
Wyszkowska, Patrycja
2017-12-01
The determination of the accuracy of functions of measured or adjusted values may be a problem in geodetic computations. The general law of covariance propagation or in case of the uncorrelated observations the propagation of variance (or the Gaussian formula) are commonly used for that purpose. That approach is theoretically justified for the linear functions. In case of the non-linear functions, the first-order Taylor series expansion is usually used but that solution is affected by the expansion error. The aim of the study is to determine the applicability of the general variance propagation law in case of the non-linear functions used in basic geodetic computations. The paper presents errors which are a result of negligence of the higher-order expressions and it determines the range of such simplification. The basis of that analysis is the comparison of the results obtained by the law of propagation of variance and the probabilistic approach, namely Monte Carlo simulations. Both methods are used to determine the accuracy of the following geodetic computations: the Cartesian coordinates of unknown point in the three-point resection problem, azimuths and distances of the Cartesian coordinates, height differences in the trigonometric and the geometric levelling. These simulations and the analysis of the results confirm the possibility of applying the general law of variance propagation in basic geodetic computations even if the functions are non-linear. The only condition is the accuracy of observations, which cannot be too low. Generally, this is not a problem with using present geodetic instruments.
Added-value joint source modelling of seismic and geodetic data
Sudhaus, Henriette; Heimann, Sebastian; Walter, Thomas R.; Krueger, Frank
2013-04-01
In tectonically active regions earthquake source studies strongly support the analysis of the current faulting processes as they reveal the location and geometry of active faults, the average slip released or more. For source modelling of shallow, moderate to large earthquakes often a combination of geodetic (GPS, InSAR) and seismic data is used. A truly joint use of these data, however, usually takes place only on a higher modelling level, where some of the first-order characteristics (time, centroid location, fault orientation, moment) have been fixed already. These required basis model parameters have to be given, assumed or inferred in a previous, separate and highly non-linear modelling step using one of the these data sets alone. We present a new earthquake rupture model implementation that realizes a fully combined data integration of surface displacement measurements and seismic data in a non-linear optimization of simple but extended planar ruptures. The model implementation allows for fast forward calculations of full seismograms and surface deformation and therefore enables us to use Monte Carlo global search algorithms. Furthermore, we benefit from the complementary character of seismic and geodetic data, e. g. the high definition of the source location from geodetic data and the sensitivity of the resolution of the seismic data on moment releases at larger depth. These increased constraints from the combined dataset make optimizations efficient, even for larger model parameter spaces and with a very limited amount of a priori assumption on the source. A vital part of our approach is rigorous data weighting based on the empirically estimated data errors. We construct full data error variance-covariance matrices for geodetic data to account for correlated data noise and also weight the seismic data based on their signal-to-noise ratio. The estimation of the data errors and the fast forward modelling opens the door for Bayesian inferences of the source
Miller, J.F.; Ethington, Raymond L.; Evans, K.R.; Holmer, L.E.; Loch, James D.; Popov, L.E.; Repetski, J.E.; Ripperdan, R.L.; Taylor, John F.
2006-01-01
We propose a candidate for the Global Standard Stratotype-section and Point (GSSP) for the base of the highest stage of the Furongian Series of the Cambrian System. The section is at Lawson Cove in the Ibex area of Millard County, Utah, USA. The marker horizon is the first appearance datum (FAD) of the conodont Cordylodus andresi Viira et Sergeyeva in Kaljo et al. [Kaljo, D., Borovko, N., Heinsalu, H., Khazanovich, K., Mens, K., Popov, L., Sergeyeva, S., Sobolevskaya, R., Viira, V., 1986. The Cambrian-Ordovician boundary in the Baltic-Ladoga clint area (North Estonia and Leningrad Region, USSR). Eesti NSV Teaduste Akadeemia Toimetised. Geologia 35, 97-108]. At this section and elsewhere this horizon also is the FAD of the trilobite Eurekia apopsis (Winston et Nicholls, 1967). This conodont characterizes the base of the Cordylodus proavus Zone, which has been recognized in many parts of the world. This trilobite characterizes the base of the Eurekia apopsis Zone, which has been recognized in many parts of North America. The proposed boundary is 46.7 m above the base of the Lava Dam Member of the Notch Peak Formation at the Lawson Cove section. Brachiopods, sequence stratigraphy, and carbon-isotope geochemistry are other tools that characterize this horizon and allow it to be recognized in other areas. ?? 2006 Nanjing Institute of Geology and Palaeontology, CAS.
GOZCARDS Source Data for Ozone Monthly Zonal Means on a Geodetic Latitude and Pressure Grid V1.01
National Aeronautics and Space Administration — The GOZCARDS Source Data for Ozone Monthly Zonal Averages on a Geodetic Latitude and Pressure Grid product (GozSmlpO3) contains zonal means and related information...
National Aeronautics and Space Administration — The GOZCARDS Source Data for Nitrous Oxide Monthly Zonal Averages on a Geodetic Latitude and Pressure Grid product (GozSmlpN2O) contains zonal means and related...
National Aeronautics and Space Administration — The GOZCARDS Source Data for Temperature Monthly Zonal Averages on a Geodetic Latitude and Pressure Grid product (GozSmlpT) contains zonal means and related...
National Aeronautics and Space Administration — The GOZCARDS Source Data for Nitric Acid Monthly Zonal Averages on a Geodetic Latitude and Pressure Grid product (GozSmlpHNO3) contains zonal means and related...
Plag, Hans-Peter
2009-01-01
Geodesy plays a key role in geodynamics, geohazards, the global water cycle, global change, atmosphere and ocean dynamics. This book covers geodesy's contribution to science and society and identifies user needs regarding geodetic observations and products.
National Aeronautics and Space Administration — The GOZCARDS Merged Data for Nitrous Oxide Monthly Zonal Averages on a Geodetic Latitude and Pressure Grid product (GozMmlpN2O) contains zonal means and related...
National Aeronautics and Space Administration — The GOZCARDS Merged Data for Water Vapor Monthly Zonal Averages on a Geodetic Latitude and Pressure Grid product (GozMmlpH2O) contains zonal means and related...
National Aeronautics and Space Administration — The GOZCARDS Merged Data for Hydrogen Chloride Monthly Zonal Averages on a Geodetic Latitude and Pressure Grid product (GozMmlpHCl) contains zonal means and related...
GOZCARDS Merged Data for Ozone Monthly Zonal Means on a Geodetic Latitude and Pressure Grid V1.01
National Aeronautics and Space Administration — The GOZCARDS Merged Data for Ozone Monthly Zonal Averages on a Geodetic Latitude and Pressure Grid product (GozMmlpO3) contains zonal means and related information...
National Aeronautics and Space Administration — The GOZCARDS Merged Data for Nitric Acid Monthly Zonal Averages on a Geodetic Latitude and Pressure Grid product (GozMmlpHNO3) contains zonal means and related...
National Aeronautics and Space Administration — Geodetic imaging is revolutionizing geophysics, but the scope of discovery has been limited by labor-intensive technological implementation of the analyses. The...
New Antarctic Gravity Anomaly Grid for Enhanced Geodetic and Geophysical Studies in Antarctica.
Scheinert, M; Ferraccioli, F; Schwabe, J; Bell, R; Studinger, M; Damaske, D; Jokat, W; Aleshkova, N; Jordan, T; Leitchenkov, G; Blankenship, D D; Damiani, T M; Young, D; Cochran, J R; Richter, T D
2016-01-28
Gravity surveying is challenging in Antarctica because of its hostile environment and inaccessibility. Nevertheless, many ground-based, airborne and shipborne gravity campaigns have been completed by the geophysical and geodetic communities since the 1980s. We present the first modern Antarctic-wide gravity data compilation derived from 13 million data points covering an area of 10 million km 2 , which corresponds to 73% coverage of the continent. The remove-compute-restore technique was applied for gridding, which facilitated levelling of the different gravity datasets with respect to an Earth Gravity Model derived from satellite data alone. The resulting free-air and Bouguer gravity anomaly grids of 10 km resolution are publicly available. These grids will enable new high-resolution combined Earth Gravity Models to be derived and represent a major step forward towards solving the geodetic polar data gap problem. They provide a new tool to investigate continental-scale lithospheric structure and geological evolution of Antarctica.
Neyer, F.; Nocerino, E.; Gruen, A.
2018-05-01
Creating 3-dimensional (3D) models of underwater scenes has become a common approach for monitoring coral reef changes and its structural complexity. Also in underwater archeology, 3D models are often created using underwater optical imagery. In this paper, we focus on the aspect of detecting small changes in the coral reef using a multi-temporal photogrammetric modelling approach, which requires a high quality control network. We show that the quality of a good geodetic network limits the direct change detection, i.e., without any further registration process. As the photogrammetric accuracy is expected to exceed the geodetic network accuracy by at least one order of magnitude, we suggest to do a fine registration based on a number of signalized points. This work is part of the Moorea Island Digital Ecosystem Avatar (IDEA) project that has been initiated in 2013 by a group of international researchers (https://mooreaidea.ethz.ch/).
Seismic and Geodetic Monitoring of the Nicoya, Costa Rica, Seismic Gap
Protti, M.; Gonzalez, V.; Schwartz, S.; Dixon, T.; Kato, T.; Kaneda, Y.; Simila, G.; Sampson, D.
2007-05-01
The Nicoya segment of the Middle America Trench has been recognized as a mature seismic gap with potential to generate a large earthquake in the near future (it ruptured with large earthquakes in 1853, 1900 and 1950). Low level of background seismicity and fast crustal deformation of the forearc are indicatives of strong coupling along the plate interface. Given its high seismic potential, the available data and especially the fact that the Nicoya peninsula extends over large part of the rupture area, this gap was selected as one of the two sites for a MARGINS-SEIZE experiment. With the goal of documenting the evolution of loading and stress release along this seismic gap, an international effort involving several institutions from Costa Rica, the United States and Japan is being carried out for over a decade in the region. This effort involves the installation of temporary and permanent seismic and geodetic networks. The seismic network includes short period, broad band and strong motion instruments. The seismic monitoring has provided valuable information on the geometry and characteristics of the plate interface. The geodetic network includes temporary and permanent GPS stations as well as surface and borehole tiltmeters. The geodetic networks have helped quantify the extend and degree of coupling. A continuously recording, three- station GPS network on the Nicoya Peninsula, Costa Rica, recorded what we believe is the first slow slip event observed along the plate interface of the Costa Rica subduction zone. We will present results from these monitoring networks. Collaborative international efforts are focused on expanding these seismic and geodetic networks to provide improved resolution of future creep events, to enhanced understanding of the mechanical behavior of the Nicoya subduction segment of the Middle American Trench and possibly capture the next large earthquake and its potential precursor deformation.
Geodetic Slip Solution for the Mw=7.4 Champerico (Guatemala) Earthquake of 07 November 2012
Ellis, A. P.; DeMets, C.; Briole, P.; Molina, E.; Flores, O.; Rivera, J.; Lasserre, C.; Lyon-Caen, H.; Lord, N. E.
2014-12-01
As the first large subduction thrust earthquake off the coast of western Guatemala in the past several decades, the 07 November 2012 Mw=7.4 earthquake offers the first opportunity for a geodetic study of coseismic and postseismic behavior for a segment of the Middle America trench where frictional coupling makes a transition from weak coupling off the coast of El Salvador to strong coupling in southern Mexico. We use measurements at 19 continuous GPS sites in Guatemala, El Salvador, and Mexico to estimate the coseismic slip and post-seismic deformation of the November 2012 Champerico (Guatemala) earthquake. Coseismic offsets range from ~47 mm near the epicenter to El Salvador. An inversion of the geodetic data indicate that that up to ~2 m of coseismic slip occurred on a ~30 km by 30 km rupture area between ~10 and 30 km depth, encouragingly close to the global CMT epicenter. The geodetic moment of 13 x 1019 N·m and corresponding magnitude of 7.4 both agree well with independent seismological estimates. An inversion for the postseismic fault afterslip shows that the transient postseismic motions recorded at 11 GPS sites are well fit with a logarithmically decaying function. More than 70 per cent of the postseismic slip occurred at the same depth or directly downdip from the main shock epicenter. At the upper limit, afterslip that occurred within 6 months of the earthquake released energy equivalent to only ~20 per cent of the coseismic moment. The seismologically derived slip solution from Ye et al. (2012), which features more highly concentrated slip than our own, fits our GPS offsets reasonably well provided that we translate their slip centroid ~51 km to the west to a position close to our own slip centroid. The geodetic and seismologic slip solutions thus suggest bounds of 2-5 m for the peak slip along a region of the interface no larger than 30 x 30 km and possibly much smaller.
Unified theory in the worldline approach
Directory of Open Access Journals (Sweden)
James P. Edwards
2015-11-01
Full Text Available We explore unified field theories based on the gauge groups SU(5 and SO(10 using the worldline approach for chiral fermions with a Wilson loop coupling to a background gauge field. Representing path ordering and chiral projection operators with functional integrals has previously reproduced the sum over the chiralities and representations of standard model particles in a compact way. This paper shows that for SU(5 the 5¯ and 10 representations – into which the Georgi–Glashow model places the left-handed fermionic content of the standard model – appear naturally and with the familiar chirality. We carry out the same analysis for flipped SU(5 and uncover a link to SO(10 unified theory. We pursue this by exploring the SO(10 theory in the same framework, the less established unified theory based on SU(6 and briefly consider the Pati–Salam model using SU(4×SU(2×SU(2.
Extending Resolution of Fault Slip With Geodetic Networks Through Optimal Network Design
Sathiakumar, Sharadha; Barbot, Sylvain Denis; Agram, Piyush
2017-12-01
Geodetic networks consisting of high precision and high rate Global Navigation Satellite Systems (GNSS) stations continuously monitor seismically active regions of the world. These networks measure surface displacements and the amount of geodetic strain accumulated in the region and give insight into the seismic potential. SuGar (Sumatra GPS Array) in Sumatra, GEONET (GNSS Earth Observation Network System) in Japan, and PBO (Plate Boundary Observatory) in California are some examples of established networks around the world that are constantly expanding with the addition of new stations to improve the quality of measurements. However, installing new stations to existing networks is tedious and expensive. Therefore, it is important to choose suitable locations for new stations to increase the precision obtained in measuring the geophysical parameters of interest. Here we describe a methodology to design optimal geodetic networks that augment the existing system and use it to investigate seismo-tectonics at convergent and transform boundaries considering land-based and seafloor geodesy. The proposed network design optimization would be pivotal to better understand seismic and tsunami hazards around the world. Land-based and seafloor networks can monitor fault slip around subduction zones with significant resolution, but transform faults are more challenging to monitor due to their near-vertical geometry.
Bennington, Ninfa; Thurber, Clifford; Feigl, Kurt; ,
2011-01-01
Several studies of the 2004 Parkfield earthquake have linked the spatial distribution of the event’s aftershocks to the mainshock slip distribution on the fault. Using geodetic data, we find a model of coseismic slip for the 2004 Parkfield earthquake with the constraint that the edges of coseismic slip patches align with aftershocks. The constraint is applied by encouraging the curvature of coseismic slip in each model cell to be equal to the negative of the curvature of seismicity density. The large patch of peak slip about 15 km northwest of the 2004 hypocenter found in the curvature-constrained model is in good agreement in location and amplitude with previous geodetic studies and the majority of strong motion studies. The curvature-constrained solution shows slip primarily between aftershock “streaks” with the continuation of moderate levels of slip to the southeast. These observations are in good agreement with strong motion studies, but inconsistent with the majority of published geodetic slip models. Southeast of the 2004 hypocenter, a patch of peak slip observed in strong motion studies is absent from our curvature-constrained model, but the available GPS data do not resolve slip in this region. We conclude that the geodetic slip model constrained by the aftershock distribution fits the geodetic data quite well and that inconsistencies between models derived from seismic and geodetic data can be attributed largely to resolution issues.
International Nuclear Information System (INIS)
Tokiwa, Tetsuya; Niizato, Tadafumi; Nohara, Tsuyoshi; Asamori, Koichi; Matsuura, Yuki; Kosaka, Hideki
2011-01-01
In this study, we present the preliminary results for the estimation of a horizontal crustal movement by using geodetic and geological approach in the Horonobe area, northern Hokkaido, Japan. The estimations have been carried out by using a GPS data and a geological cross section obtained by applying balanced-section method. As results of this study, both of the shortening rates estimated by GPS data and balanced-section method indicate several millimeters per year. Namely, there is no contradiction between geodetic and geological data, and it is considered that Horonobe area is still situated similar tendency and magnitude of a crustal movement. It is seemingly considered that geodetic data is unhelpful for estimating the long-term crustal movement, because period of geodetic observations is a very short. However, the result of this study indicates that geodetic data provide valuable information for estimating the long-term crustal movement in the area, and it is considered that geodetic approach play an important role in improvement of the credibility of evaluation for prediction of long-term stability. (author)
A unified transmission loss allocation method
International Nuclear Information System (INIS)
Ding, Qifeng; Abur, Ali
2007-01-01
A new unified method which allocates transmission losses either to buses in a pool market or to individual transactions in a bilateral contract market is presented in this paper. A detailed derivation of the method is given. A bus-loss matrix and a transaction-loss matrix are developed to show the interactions between bus injections and transactions. It is further demonstrated that the ''Physical-power-flow-based'' method can be obtained as an approximation of this unified approach under certain simplifying assumptions. Test systems are used to illustrate how the proposed method behaves under different possible scenarios. (author)
Unifying distribution functions: some lesser known distributions.
Moya-Cessa, J R; Moya-Cessa, H; Berriel-Valdos, L R; Aguilar-Loreto, O; Barberis-Blostein, P
2008-08-01
We show that there is a way to unify distribution functions that describe simultaneously a classical signal in space and (spatial) frequency and position and momentum for a quantum system. Probably the most well known of them is the Wigner distribution function. We show how to unify functions of the Cohen class, Rihaczek's complex energy function, and Husimi and Glauber-Sudarshan distribution functions. We do this by showing how they may be obtained from ordered forms of creation and annihilation operators and by obtaining them in terms of expectation values in different eigenbases.
Technical writing practically unified through industry
Houston, L. S.
1981-01-01
General background details in the development of a university level technical writing program, based upon the writing tasks of the student's occupations, are summarized. Objectives and methods for unifying the courses of study with the needs of industry are discussed. Four academic course divisions, Industries Technologies, in which preparation and training are offered are: Animal, Horticulture, Agriculture, and Agricultural Business. Occupational competence is cited as the main goal for these programs in which technical writing is to be practically unified through industry. Course descriptions are also provided.
Prospects of a Unified Management System
DEFF Research Database (Denmark)
Jørgensen, Tine Herreborg; Simonsen, Gorm
2002-01-01
In this article, the trend among management systems towards a common structure and the inclusion of additional areas of corporate concern (quality, environment, occupational health and safety and social responsibility) is outlined. The article suggests that a large part of the work associated...... with implementing and maintaining standardised management systems can be rationalised by developing a ?unified system?. The unified system is proposed to consist of a common basic standard of general managerial methodology expandable with supplements, which are related to the specific areas of concern...
Belli, A.; Exertier, P.; Lemoine, F. G.; Chinn, D. S.; Zelensky, N. P.
2017-12-01
The GGOS objectives are to maintain a geodetic network with an accuracy of 1 mm and a stability of 0.1 mm per year. For years, the laser ranging technique, which provide very accurate absolute distances to geodetic targets enable to determine the scale factor as well as coordinates of the geocenter. In order to achieve this goal, systematic errors appearing in the laser ranging measurements must be considered and solved. In addition to Range Bias (RB), which is the primary source of uncertainty of the technique, Time Bias (TB) has been recently detected by using the Time Transfer by Laser Link (T2L2) space instrument capability on-board the satellite Jason-2. Instead of determining TB through the precise orbit determination that is applied to commonly used geodetic targets like LAGEOS to estimate global geodetic products, we have developed, independently, a dedicated method to transfer time between remote satellite laser ranging stations. As a result, the evolving clock phase shift to UTC of around 30 stations has been determined under the form of time series of time bias per station from 2008 to 2016 with an accuracy of 3-4 ns. It demonstrated the difficulty, in terms of Time & Frequency used technologies, to locally maintain accuracy and long term stability at least in the range of 100 ns that is the current requirement for time measurements (UTC) for the laser ranging technique. Because some laser ranging stations oftently exceed this limit (from 100 ns to a few μs) we have been studying these effects first on the precision orbit determination itself, second on the station positioning. We discuss the impact of TB on LAGEOS and Jason-2 orbits, which appears to affect the along-track component essentially. We also investigate the role of TB in global geodetic parameters as the station coordinates. Finally, we propose to provide the community with time series of time bias of laser ranging stations, under the form of a data- handling-file in order to be included in
Minster, J. H.; Altamimi, Z.; Blewitt, G.; Carter, W. E.; Cazenave, A. A.; Davis, J. L.; Dragert, H.; Feary, D. A.; Herring, T.; Larson, K. M.; Ries, J. C.; Sandwell, D. T.; Wahr, J. M.
2009-12-01
Over the past half-century, space geodetic technologies have changed profoundly the way we look at the planet, not only in the matter of details and accuracy, but also in the matter of how the entire planet changes with time, even on “human” time scales. The advent of space geodesy has provided exquisite images of the ever-changing land and ocean topography and global gravity field of the planet. We now enjoy an International Terrestrial Reference System with a time-dependent geocenter position accurate to a few millimeters. We can image small and large tectonic deformations of the surface before, during, and after earthquakes and volcanic eruptions. We measure both the past subtle changes as well as the recent dramatic changes in the ice sheets, and track global and regional sea-level change to a precision of a millimeter per year or better. The remarkable achievements of Earth observing missions over the past two decades, and the success of future international missions described in the Decadal Survey depend both implicitly and explicitly on the continued availability and enhancement of a reliable and resilient global infrastructure for precise geodesy, and on ongoing advances in geodetic science that are linked to it. This allows us to deal with global scientific, technological and social issues such as climate change and natural hazards, but the impact of the global precise geodetic infrastructure also permeates our everyday lives. Nowadays drivers, aviators, and sailors can determine their positions inexpensively to meter precision in real time, anywhere on the planet. In the foreseeable future, not only will we be able to know a vehicle’s position to centimeter accuracy in real time, but also to control that position, and thus introduce autonomous navigation systems for many tasks which are beyond the reach of “manual” navigation capabilities. This vision will only be realized with sustained international support of the precise global geodetic
Enhanced three-dimensional stochastic adjustment for combined volcano geodetic networks
Del Potro, R.; Muller, C.
2009-12-01
Volcano geodesy is unquestionably a necessary technique in studies of physical volcanology and for eruption early warning systems. However, as every volcano geodesist knows, obtaining measurements of the required resolution using traditional campaigns and techniques is time consuming and requires a large manpower. Moreover, most volcano geodetic networks worldwide use a combination of data from traditional techniques; levelling, electronic distance measurements (EDM), triangulation and Global Navigation Satellite Systems (GNSS) but, in most cases, these data are surveyed, analysed and adjusted independently. This then leaves it to the authors’ criteria to decide which technique renders the most realistic results in each case. Herein we present a way of solving the problem of inter-methodology data integration in a cost-effective manner following a methodology were all the geodetic data of a redundant, combined network (e.g. surveyed by GNSS, levelling, distance, angular data, INSAR, extensometers, etc.) is adjusted stochastically within a single three-dimensional referential frame. The adjustment methodology is based on the least mean square method and links the data with its geometrical component providing combined, precise, three-dimensional, displacement vectors, relative to external reference points as well as stochastically-quantified, benchmark-specific, uncertainty ellipsoids. Three steps in the adjustment allow identifying, and hence dismissing, flagrant measurement errors (antenna height, atmospheric effects, etc.), checking the consistency of external reference points and a final adjustment of the data. Moreover, since the statistical indicators can be obtained from expected uncertainties in the measurements of the different geodetic techniques used (i.e. independent of the measured data), it is possible to run a priori simulations of a geodetic network in order to constrain its resolution, and reduce logistics, before the network is even built. In this
Earth Science Community IT Resources through a Unified Data and Analysis Portal
Bock, Y.; Webb, F. H.; Kedar, S.; Pierce, M.; Scharber, M.; Argus, D. F.; Aydin, G.; Chang, R.; Dong, D.; Fang, P.; Granat, R. A.; Jamason, P.; Newport, B. J.; Owen, S. E.; Parker, J. W.; Prawirodirdjo, L.; Vernon, F.; Wadsworth, G.
2006-12-01
We are in the process of merging the capabilities of three NASA-funded projects under the umbrella of the NASA Access Project, "Modeling and On-the-fly Solutions for Solid Earth Sciences (MOSES)" to facilitate data mining and modeling of rapidly expanding multi-disciplinary geoscience data sets. (1) The SCIGN- REASoN project is focused on the combination, validation, archive, and delivery of high-level data products and data mining capabilities from space geodetic measurements, in particular from over 600 CGPS stations in Western North America; (2) The QuakeSim project is developing linked Web service environments for supporting high performance models of crustal deformation from a variety of geophysical sensors, including GPS and seismic instruments; (3) The SENH-Applications GPS/Seismic integration project has developed a prototype real-time GPS/seismic displacement meter for seismic hazard mitigation and monitoring of critical infrastructure. The focus of the MOSES project is to enable direct interaction between modelers and data/data-product providers using Web services, within a unified portal architecture. Modeling applications include, for example, time series analysis of continuous and real-time data (e.g., RDAHMM and st_filter programs) and fault dislocation modeling (e.g., Simplex program). Community resources include access to extensive infrastructure and distributed data archive holdings, an on-line map server/client linked to a GIS database, a "GPS Explorer" data portal that is extensible to heterogeneous data sets, and "Geophysical Resource Web Services." We present the current capabilities of the unified data and analysis portal, and provide a few examples of combinations of independent geophysical measurements.
The unified coordination language UnCL.
F.S. de Boer (Frank); J.V. Guillen Scholten (Juan); J.F. Jacob (Joost)
2005-01-01
textabstractIn this paper we show how to use a (subset) of UML as an Unified Coordination Language (UnCL) that is based on a separation of concerns between coordination and computation. As such UnCL provides a general language for the coordination of, in particular, object-oriented applications. The
A Unified Introduction to Ordinary Differential Equations
Lutzer, Carl V.
2006-01-01
This article describes how a presentation from the point of view of differential operators can be used to (partially) unify the myriad techniques in an introductory course in ordinary differential equations by providing students with a powerful, flexible paradigm that extends into (or from) linear algebra. (Contains 1 footnote.)
Unifying Learning Object Repositories in MACE
Prause, Christian; Ternier, Stefaan; De Jong, Tim; Apelt, Stefan; Scholten, Marius; Wolpers, Martin; Eisenhauer, Markus; Vandeputte, Bram; Specht, Marcus; Duval, Erik
2007-01-01
Prause, C., Ternier, S., De Jong, T., Apelt, S., Scholten, M., Wolpers, M., et al. (2007). Unifying Learning Object Repositories in MACE. In D. Massart, J.-N. Colin & F. V. Assche (Eds.). Proceedings of the First International Workshop on Learning Object Discovery & Exchange (LODE'07). September,
Unify a hazardous materials/waste program
International Nuclear Information System (INIS)
Carson, H.T.
1988-01-01
Efficiently managing a hazardous materials/waste program in a multi-facility, multi-product corporation is a major challenge. This paper describes several methods to help unify a program and gain maximum efficiency of manpower and to minimize risk
A unified theory in higher dimensions
Energy Technology Data Exchange (ETDEWEB)
Kapetanakis, D. (National Research Centre for the Physical Sciences Democritos, Athens (Greece)); Zoupanos, G. (European Organization for Nuclear Research, Geneva (Switzerland))
1990-10-11
We present a grand unified model defined in ten dimensions and based on the group SO(13). The model is dimensionally reduced over the non-simply-connected space (Su(3)/U(1)xU(1))/Z{sub 2} giving in four dimensions the standard model. (orig.).
A unified theory in higher dimensions
International Nuclear Information System (INIS)
Kapetanakis, D.; Zoupanos, G.
1990-01-01
We present a grand unified model defined in ten dimensions and based on the group SO(13). The model is dimensionally reduced over the non-simply-connected space [Su(3)/U(1)xU(1)]/Z 2 giving in four dimensions the standard model. (orig.)
Toward a Unified Theory of Human Reasoning.
Sternberg, Robert J.
1986-01-01
The goal of this unified theory of human reasoning is to specify what constitutes reasoning and to characterize the psychological distinction between inductive and deductive reasoning. The theory views reasoning as the controlled and mediated application of three processes (encoding, comparison and selective combination) to inferential rules. (JAZ)
IDEA: A Unifying Theory for Evaluation Systems
DEFF Research Database (Denmark)
Bella, Giampaolo; Giustolisi, Rosario
2017-01-01
Secure systems for voting, exams, auctions and conference paper management are theorised to address the same problem, that of secure evaluations. In support of such a unifying theory comes a model for Secure Evaluation Systems (SES), which offers innovative common grounds to understand all four...
Barbolini, Natasha; Rubidge, Bruce; Bamford, Marion K.
2018-04-01
The main Karoo Basin (MKB), internationally renowned for its wealth of fossil tetrapods, has been lithostratigraphically subdivided into three discrete regions: two (east and west) proximal facies adjacent to the Cape Fold Belt, and a distal facies, away from the Cape Fold Belt. Because of lithological differences between formations of the proximal and distal sectors of the MKB, it has been difficult to correlate time-equivalent lithostratigraphic units in the different sectors. Palynology provides a tool for refining stratigraphic correlations within the MKB, but only species with restricted ranges are biostratigraphically significant. Restricted-range palynomorph taxa from the Ecca and Beaufort groups indicate the following relationships: the lowermost Vryheid Formation palynoflora can be strongly correlated with that of the Prince Albert Formation, whereas the Whitehill-Collingham formations and No. 2 seam (Vryheid Formation), and the Ripon Formation and No. 4 seam (Vryheid Formation) can be tentatively linked using palynology. The lower-middle Normandien Formation in the north is chronologically equivalent to the Ripplemead member of the Balfour Formation in the south. Although the Ecca-Beaufort Group boundary is known to be diachronous, restricted-range palynomorphs cannot yet confirm that the uppermost Ecca Group in the northern part of the basin was deposited at the same time as the lower Beaufort Group in the south. This study demonstrates that despite diachronous ranges of some taxa, palynology is useful in correlating age-equivalent lithostratigraphic units in the proximal and distal sectors of the basin. A new First Appearance Datum (FAD) palynozonation for the Karoo is presented that is calibrated by the most recent radiometric dates for South Africa, Australia, and South America. The new zones are also correlated with Permian successions in Antarctica, Zambia, Botswana, and India. Future palynostratigraphic work in South Africa must take into account
Radial and Regge excitations in unified, grand unified and subconstituent models
International Nuclear Information System (INIS)
Schnitzer, H.J.
1981-01-01
Necessary group theoretic conditions for all elementary gauge bosons and fermions of an arbitrary renormalizable gauge theory to lie on Regge trajectories are reviewed. It is then argued that in properly unified gauge theories all particles of a given spin lie on Regge trajectories. This then implies that a properly unified gauge theory has no local U(1) factor groups, and no massive fermion singlets. A consideration of the general pattern of Regge and radial recurrences to be expected in quantum field theories suggests that the presence or absence of spin 3/2 quarks and/or leptons in the TeV region will provide crucial clues to enable one to distinguish between various classes of unified, grand unified, and subconstituent models. The correct interpretation of such excited fermions will require correlation with the higgs boson mass and possible radial and Regge excitations of the weak vector bosons. (orig.)
Unified treatment of the classical and quantum mechanics
International Nuclear Information System (INIS)
Shirokov, Yu.M.
1979-01-01
Classical and Quantum Mechanics are unified in the sense that almost all axioms of both mechanics are identical. The only distinction is the explicit form of one algebraic identity. The unified theory is applied to scattering problem. (Z.M.)
designing a framework for a unified electronic identity system
African Journals Online (AJOL)
DJFLEX
In this paper, a Unified Identity System is proposed where single electronic identity (eID) is issued that can be used ... online commerce and public sector organizations. Because ..... SearchUnifiedCommunications.com Definitions, Access date.
Pauk, Benjamin A.; Power, John A.; Lisowski, Mike; Dzurisin, Daniel; Iwatsubo, Eugene Y.; Melbourne, Tim
2001-01-01
Between August 3 and 8,2000,the Alaska Volcano Observatory completed a Global Positioning System (GPS) survey at Augustine Volcano, Alaska. Augustine is a frequently active calcalkaline volcano located in the lower portion of Cook Inlet (fig. 1), with reported eruptions in 1812, 1882, 1909?, 1935, 1964, 1976, and 1986 (Miller et al., 1998). Geodetic measurements using electronic and optical surveying techniques (EDM and theodolite) were begun at Augustine Volcano in 1986. In 1988 and 1989, an island-wide trilateration network comprising 19 benchmarks was completed and measured in its entirety (Power and Iwatsubo, 1998). Partial GPS surveys of the Augustine Island geodetic network were completed in 1992 and 1995; however, neither of these surveys included all marks on the island.Additional GPS measurements of benchmarks A5 and A15 (fig. 2) were made during the summers of 1992, 1993, 1994, and 1996. The goals of the 2000 GPS survey were to:1) re-measure all existing benchmarks on Augustine Island using a homogeneous set of GPS equipment operated in a consistent manner, 2) add measurements at benchmarks on the western shore of Cook Inlet at distances of 15 to 25 km, 3) add measurements at an existing benchmark (BURR) on Augustine Island that was not previously surveyed, and 4) add additional marks in areas of the island thought to be actively deforming. The entire survey resulted in collection of GPS data at a total of 24 sites (fig. 1 and 2). In this report we describe the methods of GPS data collection and processing used at Augustine during the 2000 survey. We use this data to calculate coordinates and elevations for all 24 sites surveyed. Data from the 2000 survey is then compared toelectronic and optical measurements made in 1988 and 1989. This report also contains a general description of all marks surveyed in 2000 and photographs of all new marks established during the 2000 survey (Appendix A).
Space Geodetic Technique Co-location in Space: Simulation Results for the GRASP Mission
Kuzmicz-Cieslak, M.; Pavlis, E. C.
2011-12-01
The Global Geodetic Observing System-GGOS, places very stringent requirements in the accuracy and stability of future realizations of the International Terrestrial Reference Frame (ITRF): an origin definition at 1 mm or better at epoch and a temporal stability on the order of 0.1 mm/y, with similar numbers for the scale (0.1 ppb) and orientation components. These goals were derived from the requirements of Earth science problems that are currently the international community's highest priority. None of the geodetic positioning techniques can achieve this goal alone. This is due in part to the non-observability of certain attributes from a single technique. Another limitation is imposed from the extent and uniformity of the tracking network and the schedule of observational availability and number of suitable targets. The final limitation derives from the difficulty to "tie" the reference points of each technique at the same site, to an accuracy that will support the GGOS goals. The future GGOS network will address decisively the ground segment and to certain extent the space segment requirements. The JPL-proposed multi-technique mission GRASP (Geodetic Reference Antenna in Space) attempts to resolve the accurate tie between techniques, using their co-location in space, onboard a well-designed spacecraft equipped with GNSS receivers, a SLR retroreflector array, a VLBI beacon and a DORIS system. Using the anticipated system performance for all four techniques at the time the GGOS network is completed (ca 2020), we generated a number of simulated data sets for the development of a TRF. Our simulation studies examine the degree to which GRASP can improve the inter-technique "tie" issue compared to the classical approach, and the likely modus operandi for such a mission. The success of the examined scenarios is judged by the quality of the origin and scale definition of the resulting TRF.
Grillo, Barbara; Braitenberg, Carla; Nagy, Ildikó; Devoti, Roberto; Zuliani, David; Fabris, Paolo
2018-04-01
Ten years' geodetic observations (2006-2016) in a natural cave of the Cansiglio Plateau (Bus de la Genziana), a limestone karstic area in northeastern Italy, are discussed. The area is of medium-high seismic risk: a strong earthquake in 1936 below the plateau (M m = 6.2) and the 1976 disastrous Friuli earthquake (M m = 6.5) are recent events. At the foothills of the karstic massif, three springs emerge, with average flow from 5 to 10 m3/s, and which are the sources of a river. The tiltmeter station is set in a natural cavity that is part of a karstic system. From March 2013, a multiparametric logger (temperature, stage, electrical conductivity) was installed in the siphon at the bottom of the cave to discover the underground hydrodynamics. The tilt records include signals induced by hydrologic and tectonic effects. The tiltmeter signals have a clear correlation to the rainfall, the discharge series of the river and the data recorded by multiparametric loggers. Additionally, the data of a permanent GPS station located on the southern slopes of the Cansiglio Massif (CANV) show also a clear correspondence with the river level. The fast water infiltration into the epikarst, closely related to daily rainfall, is distinguished in the tilt records from the characteristic time evolution of the karstic springs, which have an impulsive level increase with successive exponential decay. It demonstrates the usefulness of geodetic measurements to reveal the hydrological response of the karst. One outcome of the work is that the tiltmeters can be used as proxies for the presence of flow channels and the pressure that builds up due to the water flow. With 10 years of data, a new multidisciplinary frontier was opened between the geodetic studies and the karstic hydrogeology to obtain a more complete geologic description of the karst plateau.
The Global Geodetic Observing System: Space Geodesy Networks for the Future
Pearlman, Michael; Pavlis, Erricos; Ma, Chopo; Altamini, Zuheir; Noll, Carey; Stowers, David
2011-01-01
Ground-based networks of co-located space geodetic techniques (VLBI, SLR, GNSS. and DORIS) are the basis for the development and maintenance of the International Terrestrial Reference frame (ITRF), which is our metric of reference for measurements of global change, The Global Geodetic Observing System (GGOS) of the International Association of Geodesy (IAG) has established a task to develop a strategy to design, integrate and maintain the fundamental geodetic network and supporting infrastructure in a sustainable way to satisfy the long-term requirements for the reference frame. The GGOS goal is an origin definition at 1 mm or better and a temporal stability on the order of 0.1 mm/y, with similar numbers for the scale and orientation components. These goals are based on scientific requirements to address sea level rise with confidence, but other applications are not far behind. Recent studies including one by the US National Research Council has strongly stated the need and the urgency for the fundamental space geodesy network. Simulations are underway to examining accuracies for origin, scale and orientation of the resulting ITRF based on various network designs and system performance to determine the optimal global network to achieve this goal. To date these simulations indicate that 24 - 32 co-located stations are adequate to define the reference frame and a more dense GNSS and DORIS network will be required to distribute the reference frame to users anywhere on Earth. Stations in the new global network will require geologically stable sites with good weather, established infrastructure, and local support and personnel. GGOS wil seek groups that are interested in participation. GGOS intends to issues a Call for Participation of groups that would like to contribute in the network implementation and operation. Some examples of integrated stations currently in operation or under development will be presented. We will examine necessary conditions and challenges in
Precise Orbital and Geodetic Parameter Estimation using SLR Observations for ILRS AAC
Directory of Open Access Journals (Sweden)
Young-Rok Kim
2013-12-01
Full Text Available In this study, we present results of precise orbital geodetic parameter estimation using satellite laser ranging (SLR observations for the International Laser Ranging Service (ILRS associate analysis center (AAC. Using normal point observations of LAGEOS-1, LAGEOS-2, ETALON-1, and ETALON-2 in SLR consolidated laser ranging data format, the NASA/ GSFC GEODYN II and SOLVE software programs were utilized for precise orbit determination (POD and finding solutions of a terrestrial reference frame (TRF and Earth orientation parameters (EOPs. For POD, a weekly-based orbit determination strategy was employed to process SLR observations taken from 20 weeks in 2013. For solutions of TRF and EOPs, loosely constrained scheme was used to integrate POD results of four geodetic SLR satellites. The coordinates of 11 ILRS core sites were determined and daily polar motion and polar motion rates were estimated. The root mean square (RMS value of post-fit residuals was used for orbit quality assessment, and both the stability of TRF and the precision of EOPs by external comparison were analyzed for verification of our solutions. Results of post-fit residuals show that the RMS of the orbits of LAGEOS-1 and LAGEOS-2 are 1.20 and 1.12 cm, and those of ETALON-1 and ETALON-2 are 1.02 and 1.11 cm, respectively. The stability analysis of TRF shows that the mean value of 3D stability of the coordinates of 11 ILRS core sites is 7.0 mm. An external comparison, with respect to International Earth rotation and Reference systems Service (IERS 08 C04 results, shows that standard deviations of polar motion Xp and Yp are 0.754 milliarcseconds (mas and 0.576 mas, respectively. Our results of precise orbital and geodetic parameter estimation are reasonable and help advance research at ILRS AAC.
ESPACE - a geodetic Master's program for the education of Satellite Application Engineers
Hedman, K.; Kirschner, S.; Seitz, F.
2012-04-01
In the last decades there has been a rapid development of new geodetic and other Earth observation satellites. Applications of these satellites such as car navigation systems, weather predictions, and, digital maps (such as Google Earth or Google Maps) play a more and more important role in our daily life. For geosciences, satellite applications such as remote sensing and precise positioning/navigation have turned out to be extremely useful and are meanwhile indispensable. Today, researchers within geodesy, climatology, oceanography, meteorology as well as within Earth system science are all dependent on up-to-date satellite data. Design, development and handling of these missions require experts with knowledge not only in space engineering, but also in the specific applications. That gives rise to a new kind of engineers - satellite application engineers. The study program for these engineers combines parts of different classical disciplines such as geodesy, aerospace engineering or electronic engineering. The satellite application engineering program Earth Oriented Space Science and Technology (ESPACE) was founded in 2005 at the Technische Universität München, mainly from institutions involved in geodesy and aerospace engineering. It is an international, interdisciplinary Master's program, and is open to students with a BSc in both Science (e.g. Geodesy, Mathematics, Informatics, Geophysics) and Engineering (e.g. Aerospace, Electronical and Mechanical Engineering). The program is completely conducted in English. ESPACE benefits from and utilizes its location in Munich with its unique concentration of expertise related to space science and technology. Teaching staff from 3 universities (Technische Universität München, Ludwig-Maximilian University, University of the Federal Armed Forces), research institutions (such as the German Aerospace Center, DLR and the German Geodetic Research Institute, DGFI) and space industry (such as EADS or Kayser-Threde) are
Deformation offshore Northern Chile monitored by a seafloor geodetic network (GeoSEA)
Hannemann, Katrin; Lange, Dietrich; Kopp, Heidrun; Petersen, Florian; Contreras-Reyes, Eduardo
2017-04-01
The Nazca-South American plate boundary around 21°S has last ruptured in an earthquake in 1877 and was identified as a seismic gap prior to the 2014 Iquique earthquake (Mw=8.1). The southern portion of this segment is still unbroken. The geodetic monitoring of the Chilean subduction zone is crucial to understand the deformation processes in this area. Most geodetic measurements rely on GPS and are therefore limited to onshore campaigns. In December 2015, we installed the GeoSEA (Geodetic Earthquake Observatory on the SEAfloor) array around 21°S of the Nazca-South American plate boundary with RV SONNE to extend the geodetic observations to the offshore areas. The GeoSEA array consists of autonomous acoustic seafloor transponders mounted on 4 m high tripods. These transponders are able to continuously measure the two-way travel time of acoustic signals between station pairs (baselines) and the properties of the sea water (sound speed, temperature and pressure) at each transponder. These measurements are used to retrieve the distances between the transponders and give insights into the deformation of the seafloor. At the Chilean subduction zone, we installed in total 23 transponders in 3 subarrays with interstation distances of up to 2500 m. On the middle continental slope in 2300 m water depth, an array consisting of 8 transponders measures across crustal faults seen in AUV mapping. A second array of 5 stations located on the outer rise monitors extension across normal plate-bending faults. The deepest deployment in 5000 m water depth located on the lower continental slope with 10 stations is designed to measure diffuse strain build-up. The transponders are intended to monitor the seafloor deformation for 3.5 years. In November 2016 during a cruise of RV Langseth, the first 11 months of data were successfully uploaded via an acoustic modem. Furthermore, an additional component of the network, GeoSURF, a self-steering autonomous vehicle (wave glider), was
Multi-planed unified switching topologies
Chen, Dong; Heidelberger, Philip; Sugawara, Yutaka
2017-07-04
An apparatus and method for extending the scalability and improving the partitionability of networks that contain all-to-all links for transporting packet traffic from a source endpoint to a destination endpoint with low per-endpoint (per-server) cost and a small number of hops. An all-to-all wiring in the baseline topology is decomposed into smaller all-to-all components in which each smaller all-to-all connection is replaced with star topology by using global switches. Stacking multiple copies of the star topology baseline network creates a multi-planed switching topology for transporting packet traffic. Point-to-point unified stacking method using global switch wiring methods connects multiple planes of a baseline topology by using the global switches to create a large network size with a low number of hops, i.e., low network latency. Grouped unified stacking method increases the scalability (network size) of a stacked topology.
Finite Unified Theories and the Higgs boson
Heinemeyer, Sven; Zoupanos, George
2012-01-01
All-loop Finite Unified Theories (FUTs) are very interesting N = 1 supersymmetric Grand Unified Theories (GUTs) realising an old field theory dream, and moreover have a remarkable predictive power due to the required reduction of couplings. Based on this theoretical framework phenomenologically consistent FUTs have been constructed. Here we review two FUT models based on the SU(5) gauge group, which can be seen as special, restricted and thus very predictive versions of the MSSM. We show that from the requirement of correct prediction of quark masses and other experimental constraints a light Higgs-boson mass in the range M_h ~ 121 - 126 GeV is predicted, in striking agreement with recent experimental results from ATLAS and CMS. The model furthermore naturally predicts a relatively heavy spectrum with colored supersymmetric particles above ~ 1.5 TeV in agreement with the non-observation of those particles at the LHC.
Can the laws of physics be unified ?
Langacker, Paul
2017-01-01
The standard model of particle physics describes our current understanding of nature's fundamental particles and their interactions, yet gaps remain. For example, it does not include a quantum theory of gravity, nor does it explain the existence of dark matter. Once complete, however, the standard model could provide a unified description of the very building blocks of the universe. Researchers have been chasing this dream for decades, and many wonder whether such a dream can ever be made a reality. Can the Laws of Physics Be Unified? is a short introduction to this exciting frontier of physics. The book is accessibly written for students and researchers across the sciences, and for scientifically minded general readers. Paul Langacker begins with an overview of the key breakthroughs that have shaped the standard model, and then describes the fundamental particles, their interactions, and their role in cosmology. He goes on to explain field theory, internal symmetries, Yang-Mills theories, strong and electro...
Unified-field theory: yesterday, today, tomorrow
International Nuclear Information System (INIS)
Bergman, P.G.
1982-01-01
Beginning with the expounding of Einstein understanding of advantages and disadvantages of general relativity theory, the authors proceed to consideration of what the complete unified theory have to be according to Einstein. The four theories which can be considered as ''unified'', namely weyl and Calutsa ones, worked out a half of century ago, and twistor twisting and supersymmetry theories, nowadays attracting attention, are briefly described and discussed. The authors come to a conclusion that achievements in elementary-particle physics have to affect any future theory, that this theory has to explain the principle contradictions between classical and quantum field theories, and that finally it can lead to change of the modern space-time model as a four-dimensional variety
Towards a Unified Global ICT Infrastructure
DEFF Research Database (Denmark)
Madsen, Ole Brun
2006-01-01
A successful evolution towards a unified global WAN platform allowing for the coexistence and interoperability of all kind of services requires careful planning of the next generation global cooperative wired and wireless information infrastructure. The absence of commonly agreed upon and adopted...... to be solved can be found in the interrelation between communication, connectivity and convergence. This paper will focus on steps to be taken in planning the physical infrastructure as a prerequisite for a successful evolution....
Unified geometric description of black hole thermodynamics
International Nuclear Information System (INIS)
Alvarez, Jose L.; Quevedo, Hernando; Sanchez, Alberto
2008-01-01
In the space of thermodynamic equilibrium states we introduce a Legendre invariant metric which contains all the information about the thermodynamics of black holes. The curvature of this thermodynamic metric becomes singular at those points where, according to the analysis of the heat capacities, phase transitions occur. This result is valid for the Kerr-Newman black hole and all its special cases and, therefore, provides a unified description of black hole phase transitions in terms of curvature singularities.
The group manifold approach to unified gravity
International Nuclear Information System (INIS)
Regge, T.
1984-01-01
These lectures start with a synopsis of historical results in the construction of unified theories of gravity. The author keeps some mathematical rigour throughout the lectures. He gives a provisional description of supermanifolds and a set of formal rules intended to manipulate superforms or supermanifolds. Super Lie groups are discussed as well as the dimensional reduction of gravity theories, the Kaluza-Klein theory. A formal introduction of supersymmetry is given. (Auth.)
Unifying Ancient and Modern Geometries Through Octonions
International Nuclear Information System (INIS)
Catto, Sultan; Gürcan, Yasemin; Kurt, Levent; Khalfan, Amish
2016-01-01
We show the first unified description of some of the oldest known geometries such as the Pappus’ theorem with more modern ones like Desargues' theorem, Monge's theorem and Ceva's theorem, through octonions, the highest normed division algebra in eight dimensions. We also show important applications in hadronic physics, giving a full description of the algebra of color applicable to quark physics, and comment on further applications. (paper)
A unified architecture of transcriptional regulatory elements
DEFF Research Database (Denmark)
Andersson, Robin; Sandelin, Albin Gustav; Danko, Charles G.
2015-01-01
Gene expression is precisely controlled in time and space through the integration of signals that act at gene promoters and gene-distal enhancers. Classically, promoters and enhancers are considered separate classes of regulatory elements, often distinguished by histone modifications. However...... and enhancers are considered a single class of functional element, with a unified architecture for transcription initiation. The context of interacting regulatory elements and the surrounding sequences determine local transcriptional output as well as the enhancer and promoter activities of individual elements....
Neutrino mixing in a grand unified theory
International Nuclear Information System (INIS)
Milton, K.; Tanaka, K.
1980-01-01
Neutrino mixing in a grand unified theory in which the neutrino mass matrix is determined by the Gell-Mann-Ramond-Slansky mechanism was investigated. With an arbitrary real right-handed Majorana mass matrix which incorporates three neutrino mass scales, the effects of the up-quark mass matrix are found to be dominant and as a result no significant mixing of ν/sub e/ occurs, while ν/sub μ/ - ν/sub γ/ mixing can be substantial
Towards a unified theory of reciprocity.
Rosas, Alejandro
2012-02-01
In a unified theory of human reciprocity, the strong and weak forms are similar because neither is biologically altruistic and both require normative motivation to support cooperation. However, strong reciprocity is necessary to support cooperation in public goods games. It involves inflicting costs on defectors; and though the costs for punishers are recouped, recouping costs requires complex institutions that would not have emerged if weak reciprocity had been enough.
A Unified Framework for Systematic Model Improvement
DEFF Research Database (Denmark)
Kristensen, Niels Rode; Madsen, Henrik; Jørgensen, Sten Bay
2003-01-01
A unified framework for improving the quality of continuous time models of dynamic systems based on experimental data is presented. The framework is based on an interplay between stochastic differential equation (SDE) modelling, statistical tests and multivariate nonparametric regression. This co......-batch bioreactor, where it is illustrated how an incorrectly modelled biomass growth rate can be pinpointed and an estimate provided of the functional relation needed to properly describe it....
Cosmic strings in unified gauge theories
International Nuclear Information System (INIS)
Everett, A.E.
1981-01-01
Some spontaneously broken gauge theories can give rise to stringlike vacuum structures (vortices). It has been pointed out by Vilenkin that in grand unified theories these can be sufficiently massive to have cosmological implications, e.g., in explaining the formation of galaxies. The circumstances in which such structures occur are examined. They do not occur in the simplest grand unified theories, but can occur in some more elaborate models which have been proposed. The cross section for the scattering of elementary particles by strings is estimated. This is used to evaluate the effect of collisions on the dynamics of a collapsing circular string, with particular attention to the question of whether energy dissipation by collision can reduce the rate of formation of black holes by collapsed strings, which may be unacceptably large in models where strings occur. It is found that the effect of collisions is not important in the case of grand unified strings, although it can be important for lighter strings
Coset realization of unifying W-algebras
International Nuclear Information System (INIS)
Blumenhagen, R.; Huebel, R.
1994-06-01
We construct several quantum coset W-algebras, e.g. sl(2,R)/U(1) and sl(2,R)+sl(2,R)/sl(2,R), and argue that they are finitely nonfreely generated. Furthermore, we discuss in detail their role as unifying W-algebras of Casimir W-algebras. We show that it is possible to give coset realizations of various types of unifying W-algebras, e.g. the diagonal cosets based on the symplectic Lie algebras sp(2n) realize the unifying W-algebras which have previously been introduced as 'WD -n '. In addition, minimal models of WD -n are studied. The coset realizations provide a generalization of level-rank-duality of dual coset pairs. As further examples of finitely nonfreely generated quantum W-algebras we discuss orbifolding of W-algebras which on the quantum level has different properties than in the classical case. We demonstrate in some examples that the classical limit according to Bowcock and Watts of these nonfreely finitely generated quantum W-algebras probably yields infinitely nonfreely generated classical W-algebras. (orig.)
Unified strength theory and its applications
Yu, Mao-Hong
2004-01-01
This is a completely new theory dealing with the yield and failure of materials under multi-axial stresses. It provides a system of yield and failure criteria adopted for most materials, from metallic materials to rocks, concretes, soils, polymers etc. The Unified Strength Theory has been applied successfully to analyse the elastic limit, plastic limit capacities, the dynamic response behavior for some structures under static and moderate impulsive load, and may be implemented in some elasto-plastic finite element computer codes. The Unified Strength Theory is described in detail and by using this theory a series of results can be obtained. The Unified Strength Theory can improve the conservative Mohr-Coulomb Theory, and since intermediate principal stress is not taken into account in the Mohr-Coulomb theory and most experimental data is not pertainable to the Mohr-Coulomb Theory, a considerable economic benefit may be obtained. The book can also increase the effect of most commercial finite element computer ...
Proton decay in grand unified theories
International Nuclear Information System (INIS)
Lucha, W.
1984-01-01
Interactions which violate the conservation of baryon and lepton number represent an intrinsic part of all grand unified theories (GUTs) of strong and electroweak interactions. These new interactions - predicted within the framework of GUTs - generate B and L violating four-fermion interactions via the exchange of superheavy particles which cannot be ascribed a well-defined baryon or lepton number. The effective coupling constant of these four-fermion interactions might be large enough to make the proton decay detectable by the present generation of experiments. In this review the basic concepts of conventional as well as supersymmetric GUTs relevant for proton decay are sketched. The baryon number violating sector of grand unified theories is discussed in more detail. Special emphasis is laid on the various selection rules arising as consequences of low-energy gauge invariance and supersymmetry for proton decay. These selection rules already determine the coarse pattern of the resulting decay modes and branching ratios without any reference to or detailed knowledge of the underlying grand unified theory. Finally the numerous theoretical predictions are summarized and confronted with experiment. (Author)
Kosek, W.; Popinski, W.; Niedzielski, T.
2011-10-01
It has been already shown that short period oscillations in polar motion, with periods less than 100 days, are very chaotic and are responsible for increase in short-term prediction errors of pole coordinates data. The wavelet technique enables to compare the geodetic and fluid excitation functions in the high frequency band in many different ways, e.g. by looking at the semblance function. The waveletbased semblance filtering enables determination the common signal in both geodetic and fluid excitation time series. In this paper the considered fluid excitation functions consist of the atmospheric, oceanic and land hydrology excitation functions from ECMWF atmospheric data produced by IERS Associated Product Centre Deutsches GeoForschungsZentrum, Potsdam. The geodetic excitation functions have been computed from the combined IERS pole coordinates data.
Simulations of VLBI observations of a geodetic satellite providing co-location in space
Anderson, James M.; Beyerle, Georg; Glaser, Susanne; Liu, Li; Männel, Benjamin; Nilsson, Tobias; Heinkelmann, Robert; Schuh, Harald
2018-02-01
We performed Monte Carlo simulations of very-long-baseline interferometry (VLBI) observations of Earth-orbiting satellites incorporating co-located space-geodetic instruments in order to study how well the VLBI frame and the spacecraft frame can be tied using such measurements. We simulated observations of spacecraft by VLBI observations, time-of-flight (TOF) measurements using a time-encoded signal in the spacecraft transmission, similar in concept to precise point positioning, and differential VLBI (D-VLBI) observations using angularly nearby quasar calibrators to compare their relative performance. We used the proposed European Geodetic Reference Antenna in Space (E-GRASP) mission as an initial test case for our software. We found that the standard VLBI technique is limited, in part, by the present lack of knowledge of the absolute offset of VLBI time to Coordinated Universal Time at the level of microseconds. TOF measurements are better able to overcome this problem and provide frame ties with uncertainties in translation and scale nearly a factor of three smaller than those yielded from VLBI measurements. If the absolute time offset issue can be resolved by external means, the VLBI results can be significantly improved and can come close to providing 1 mm accuracy in the frame tie parameters. D-VLBI observations with optimum performance assumptions provide roughly a factor of two higher uncertainties for the E-GRASP orbit. We additionally simulated how station and spacecraft position offsets affect the frame tie performance.
Uncertainty assessment in geodetic network adjustment by combining GUM and Monte-Carlo-simulations
Niemeier, Wolfgang; Tengen, Dieter
2017-06-01
In this article first ideas are presented to extend the classical concept of geodetic network adjustment by introducing a new method for uncertainty assessment as two-step analysis. In the first step the raw data and possible influencing factors are analyzed using uncertainty modeling according to GUM (Guidelines to the Expression of Uncertainty in Measurements). This approach is well established in metrology, but rarely adapted within Geodesy. The second step consists of Monte-Carlo-Simulations (MC-simulations) for the complete processing chain from raw input data and pre-processing to adjustment computations and quality assessment. To perform these simulations, possible realizations of raw data and the influencing factors are generated, using probability distributions for all variables and the established concept of pseudo-random number generators. Final result is a point cloud which represents the uncertainty of the estimated coordinates; a confidence region can be assigned to these point clouds, as well. This concept may replace the common concept of variance propagation and the quality assessment of adjustment parameters by using their covariance matrix. It allows a new way for uncertainty assessment in accordance with the GUM concept for uncertainty modelling and propagation. As practical example the local tie network in "Metsähovi Fundamental Station", Finland is used, where classical geodetic observations are combined with GNSS data.
Plate Motion and Crustal Deformation Estimated with Geodetic Data from the Global Positioning System
Argus, Donald F.; Heflin, Michael B.
1995-01-01
We use geodetic data taken over four years with the Global Positioning System (GPS) to estimate: (1) motion between six major plates and (2) motion relative to these plates of ten sites in plate boundary zones. The degree of consistency between geodetic velocities and rigid plates requires the (one-dimensional) standard errors in horizontal velocities to be approx. 2 mm/yr. Each of the 15 angular velocities describing motion between plate pairs that we estimate with GPS differs insignificantly from the corresponding angular velocity in global plate motion model NUVEL-1A, which averages motion over the past 3 m.y. The motion of the Pacific plate relative to both the Eurasian and North American plates is observed to be faster than predicted by NUVEL-1A, supporting the inference from Very Long B ase- line Interferometry (VLBI) that motion of the Pacific plate has speed up over the past few m.y. The Eurasia-North America pole of rotation is estimated to be north of NUVEL-1A, consistent with the independent hypothesis that the pole has recently migrated northward across northeast Asia to near the Lena River delta. Victoria, which lies above the main thrust at the Cascadia subduction zone, moves relative to the interior of the overriding plate at 30% of the velocity of the subducting plate, reinforcing the conclusion that the thrust there is locked beneath the continental shelf and slope.
Directory of Open Access Journals (Sweden)
S. Manneela
2016-06-01
Full Text Available Exemplifying the tsunami source immediately after an earthquake is the most critical component of tsunami early warning, as not every earthquake generates a tsunami. After a major under sea earthquake, it is very important to determine whether or not it has actually triggered the deadly wave. The near real-time observations from near field networks such as strong motion and Global Positioning System (GPS allows rapid determination of fault geometry. Here we present a complete processing chain of Indian Tsunami Early Warning System (ITEWS, starting from acquisition of geodetic raw data, processing, inversion and simulating the situation as it would be at warning center during any major earthquake. We determine the earthquake moment magnitude and generate the centroid moment tensor solution using a novel approach which are the key elements for tsunami early warning. Though the well established seismic monitoring network, numerical modeling and dissemination system are currently capable to provide tsunami warnings to most of the countries in and around the Indian Ocean, the study highlights the critical role of geodetic observations in determination of tsunami source for high-quality forecasting.
New Antarctic Gravity Anomaly Grid for Enhanced Geodetic and Geophysical Studies in Antarctica
Scheinert, M.; Ferraccioli, F.; Schwabe, J.; Bell, R.; Studinger, M.; Damaske, D.; Jokat, W.; Aleshkova, N.; Jordan, T.; Leitchenkov, G.; Blankenship, D. D.; Damiani, T. M.; Young, D.; Cochran, J. R.; Richter, T. D.
2018-01-01
Gravity surveying is challenging in Antarctica because of its hostile environment and inaccessibility. Nevertheless, many ground-based, airborne and shipborne gravity campaigns have been completed by the geophysical and geodetic communities since the 1980s. We present the first modern Antarctic-wide gravity data compilation derived from 13 million data points covering an area of 10 million km2, which corresponds to 73% coverage of the continent. The remove-compute-restore technique was applied for gridding, which facilitated levelling of the different gravity datasets with respect to an Earth Gravity Model derived from satellite data alone. The resulting free-air and Bouguer gravity anomaly grids of 10 km resolution are publicly available. These grids will enable new high-resolution combined Earth Gravity Models to be derived and represent a major step forward towards solving the geodetic polar data gap problem. They provide a new tool to investigate continental-scale lithospheric structure and geological evolution of Antarctica. PMID:29326484
Application of Geodetic VLBI Data to Obtaining Long-Term Light Curves for Astrophysics
Kijima, Masachika
2010-01-01
The long-term light curve is important to research on binary black holes and disk instability in AGNs. The light curves have been drawn mainly using single dish data provided by the University of Michigan Radio Observatory and the Metsahovi Radio Observatory. Hence, thus far, we have to research on limited sources. I attempt to draw light curves using VLBI data for those sources that have not been monitored by any observatories with single dish. I developed software, analyzed all geodetic VLBI data available at the IVS Data Centers, and drew the light curves at 8 GHz. In this report, I show the tentative results for two AGNs. I compared two light curves of 4C39.25, which were drawn based on single dish data and on VLBI data. I confirmed that the two light curves were consistent. Furthermore, I succeeded in drawing the light curve of 0454-234 with VLBI data, which has not been monitored by any observatory with single dish. In this report, I suggest that the geodetic VLBI archive data is useful to obtain the long-term light curves at radio bands for astrophysics.
Geodetic reanalysis of annual glaciological mass balances (2001-2011) of Hintereisferner, Austria
Klug, Christoph; Bollmann, Erik; Galos, Stephan Peter; Nicholson, Lindsey; Prinz, Rainer; Rieg, Lorenzo; Sailer, Rudolf; Stötter, Johann; Kaser, Georg
2018-03-01
This study presents a reanalysis of the glaciologically obtained annual glacier mass balances at Hintereisferner, Ötztal Alps, Austria, for the period 2001-2011. The reanalysis is accomplished through a comparison with geodetically derived mass changes, using annual high-resolution airborne laser scanning (ALS). The grid-based adjustments for the method-inherent differences are discussed along with associated uncertainties and discrepancies of the two methods of mass balance measurements. A statistical comparison of the two datasets shows no significant difference for seven annual, as well as the cumulative, mass changes over the 10-year record. Yet, the statistical view hides significant differences in the mass balance years 2002/03 (glaciological minus geodetic records = +0.92 m w.e.), 2005/06 (+0.60 m w.e.), and 2006/07 (-0.45 m w.e.). We conclude that exceptional meteorological conditions can render the usual glaciological observational network inadequate. Furthermore, we consider that ALS data reliably reproduce the annual mass balance and can be seen as validation or calibration tools for the glaciological method.
Contribution of SELENE-2 geodetic measurements to constrain the lunar internal structure
Matsumoto, K.; Kikuchi, F.; Yamada, R.; Iwata, T.; Kono, Y.; Tsuruta, S.; Hanada, H.; Goossens, S. J.; Ishihara, Y.; Kamata, S.; Sasaki, S.
2012-12-01
Internal structure and composition of the Moon provide important clue and constraints on theories for how the Moon formed and evolved. The Apollo seismic network has contributed to the internal structure modeling. Efforts have been made to detect the lunar core from the noisy Apollo data (e.g., [1], [2]), but there is scant information about the structure below the deepest moonquakes at about 1000 km depth. On the other hand, there have been geodetic studies to infer the deep structure of the Moon. For example, LLR (Lunar Laser Ranging) data analyses detected a displacement of the lunar pole of rotation, indicating that dissipation is acting on the rotation arising from a fluid core [3]. Bayesian inversion using geodetic data (such as mass, moments of inertia, tidal Love numbers k2 and h2, and quality factor Q) also suggests a fluid core and partial melt in the lower mantle region [4]. Further improvements in determining the second-degree gravity coefficients (which will lead to better estimates of moments of inertia) and the Love number k2 will help us to better constrain the lunar internal structure. Differential VLBI (Very Long Baseline Interferometry) technique, which was used in the Japanese lunar exploration mission SELENE (Sept. 2007 - June 2009), is expected to contribute to better determining the second-degree potential Love number k2 and low-degree gravity coefficients. SELENE will be followed by the future lunar mission SELENE-2 which will carry both a lander and an orbiter. We propose to put the SELENE-type radio sources on these spacecraft in order to accurately estimate k2 and the low-degree gravity coefficients. By using the same-beam VLBI tracking technique, these parameters will be retrieved through precision orbit determination of the orbiter with respect to the lander which serves as a reference. The VLBI mission with the radio sources is currently one of the mission candidates for SELENE-2. We have conducted a preliminary simulation study on the
Model of unified gauge fields; Le modele des champs de jauge unifies
Energy Technology Data Exchange (ETDEWEB)
Leite Lopes, J. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)
1998-04-01
In this work, we discuss the physical ideas which represents the basis for the unified gauge field model. Despite of the difficulties that we presently have for embodying in a natural manner muons and hadrons in that model, we have the feeling that we are on the way which seems to lead to the construction of a theory in which the Maxwell electromagnetic field and the Fermi weak interaction field are manifestations of a unique subjacent physical entity - the unified gauge fields. (author) 22 refs., 6 figs.
Carafa, Michele M. C.; Bird, Peter
2016-07-01
The lithosphere of Italy is exposed to a number of different short-term strain transients, including but not limited to landslides, postseismic relaxation, and volcanic inflation/deflation. These transients affect GPS velocities and complicate the assessment of the long-term tectonic component of the surface deformation. In a companion paper we present a method for anticipating the principal patterns of nontectonic, short-term strains and building this information into the covariance matrix of the geodetic velocities. In this work we apply this method to Italian GPS velocities to build an augmented covariance matrix that characterizes all expected discrepancies between short- and long-term velocities. We find that formal uncertainties usually reported for GPS measurements are smaller than the variability of the same benchmarks across a geologic time span. Furthermore, we include in our modeling the azimuths of most compressive horizontal principal stresses (SHmax) because GPS data cannot resolve the active kinematics of coastal and offshore areas. We find that the final tectonic model can be made relatively insensitive to short-term interfering processes if the augmented covariance matrix and SHmax data records are used in the objective function. This results in a preferred neotectonic model that is also in closer agreement with independent geologic and seismological constraints and has the advantage of reducing short-term biases in forecasts of long-term seismicity.
LEP constraints on grand unified theories
International Nuclear Information System (INIS)
Sarkar, Utpal
1993-01-01
Recent developments on grand unified theories (GUTs) in the context of the LEP measurements of the coupling constants are reviewed. The three coupling constants at the electroweak scale have been measured at LEP quite precisely. One can allow these couplings to evolve with energy following the renormalization group equations for the various groups and find out whether all the coupling constants meet at any energy. It was pointed out that the minimal SU(5) grand unified theory fails to satisfy this test. However, various extensions of the theory are still allowed. These extensions include (i) supersymmetric SU(5) GUT, with some arbitrariness in the susy breaking scale arising from the threshold corrections, (ii) non-susy SU(5) GUTs with additional fermions as well as Higgs multiplets, which has masses of the order of TeV, and (iii) non-renormalizable effect of gravity with a fine tuned relation among the coupling constants at the unification energy. The LEP results also constrain GUTs with an intermediate symmetry breaking scale. By adjusting the intermediate symmetry breaking scale, one usually can have unification, but these theories get constrained. For example, the left-right symmetric theories coming from GUTs can be broken only at energies higher than about ∼10 10 GeV. This implies that if right handed gauge bosons are found at energies lower than this scale, then that will rule out the possibility of grand unification. Another recent interesting development on the subject, namely, low energy unification, is discussed in this context. All the coupling constants are unified at energies of the order of ∼10 8 GeV when they are embedded in an SU(15)GUT, with some particular symmetry breaking pattern. But even in this case the results of the intermediate symmetry breaking scale remain unchanged. (author). 16 refs., 3 figs
Cosmotopological relation for a unified field theory
International Nuclear Information System (INIS)
Bij, J. J. van der
2007-01-01
I present an argument, based on the topology of the universe, why there are three generations of fermions. The argument implies a preferred unified gauge group of SU(5), but with SO(10) representations of the fermions. The breaking pattern SU(5)→SU(3)xSU(2)xU(1) is preferred over the pattern SU(5)→SU(4)xU(1). On the basis of the argument one expects an asymmetry in the early universe microwave data, which might have been detected already
General unifying features of controlled quantum phenomena
International Nuclear Information System (INIS)
Pechen, Alexander; Brif, Constantin; Wu, Rebing; Chakrabarti, Raj; Rabitz, Herschel
2010-01-01
Many proposals have been put forth for controlling quantum phenomena, including open-loop, adaptive feedback, and real-time feedback control. Each of these approaches has been viewed as operationally, and even physically, distinct from the others. This work shows that all such scenarios inherently share the same fundamental control features residing in the topology of the landscape relating the target physical observable to the applied controls. This unified foundation may provide a basis for development of hybrid control schemes that would combine the advantages of the existing approaches to achieve the best overall performance.
Towards unifying inheritance and automatic program specialization
DEFF Research Database (Denmark)
Schultz, Ulrik Pagh
2002-01-01
and specialization of classes (inheritance) are considered different abstractions. We present a new programming language, Lapis, that unifies inheritance and program specialization at the conceptual, syntactic, and semantic levels. This paper presents the initial development of Lapis, which uses inheritance...... with covariant specialization to control the automatic application of program specialization to class members. Lapis integrates object-oriented concepts, block structure, and techniques from automatic program specialization to provide both a language where object-oriented designs can be e#ciently implemented...
Leading gravitational corrections and a unified universe
DEFF Research Database (Denmark)
Codello, Alessandro; Jain, Rajeev Kumar
2016-01-01
Leading order gravitational corrections to the Einstein-Hilbert action can lead to a consistent picture of the universe by unifying the epochs of inflation and dark energy in a single framework. While the leading local correction induces an inflationary phase in the early universe, the leading...... nonlocal term leads to an accelerated expansion of the universe at the present epoch. We argue that both the leading UV and IR terms can be obtained within the framework of a covariant effective field theory of gravity. The perturbative gravitational corrections therefore provide a fundamental basis...
TOWARDS A UNIFIED VIEW OF METAHEURISTICS
Directory of Open Access Journals (Sweden)
El-Ghazali Talbi
2013-02-01
Full Text Available This talk provides a complete background on metaheuristics and presents in a unified view the main design questions for all families of metaheuristics and clearly illustrates how to implement the algorithms under a software framework to reuse both the design and code. The key search components of metaheuristics are considered as a toolbox for: - Designing efficient metaheuristics (e.g. local search, tabu search, simulated annealing, evolutionary algorithms, particle swarm optimization, scatter search, ant colonies, bee colonies, artificial immune systems for optimization problems. - Designing efficient metaheuristics for multi-objective optimization problems. - Designing hybrid, parallel and distributed metaheuristics. - Implementing metaheuristics on sequential and parallel machines.
Improvements on a Unified Dark Matter Model
Directory of Open Access Journals (Sweden)
Del Popolo A.
2016-06-01
Full Text Available We study, by means of a spherical collapse model, the effect of shear, rotation, and baryons on a generalized Chaplygin gas (gCg dominated universe. We show that shear, rotation, and the presence of baryons slow down the collapse compared to the simple spherical collapse model. The slowing down in the growth of density perturbation is able to solve the instability of the unified dark matter (UDM models described in previous papers (e.g. Sandvik et al. 2004 at the linear perturbation level, as also shown by a direct comparison of our model with previous results.
Meertens, C. M.; Boler, F. M.; Ertz, D. J.; Mencin, D.; Phillips, D.; Baker, S.
2017-12-01
UNAVCO, in its role as a NSF facility for geodetic infrastructure and data, has succeeded for over two decades using on-premises infrastructure, and while the promise of cloud-based infrastructure is well-established, significant questions about suitability of such infrastructure for facility-scale services remain. Primarily through the GeoSciCloud award from NSF EarthCube, UNAVCO is investigating the costs, advantages, and disadvantages of providing its geodetic data and services in the cloud versus using UNAVCO's on-premises infrastructure. (IRIS is a collaborator on the project and is performing its own suite of investigations). In contrast to the 2-3 year time scale for the research cycle, the time scale of operation and planning for NSF facilities is for a minimum of five years and for some services extends to a decade or more. Planning for on-premises infrastructure is deliberate, and migrations typically take months to years to fully implement. Migrations to a cloud environment can only go forward with similar deliberate planning and understanding of all costs and benefits. The EarthCube GeoSciCloud project is intended to address the uncertainties of facility-level operations in the cloud. Investigations are being performed in a commercial cloud environment (Amazon AWS) during the first year of the project and in a private cloud environment (NSF XSEDE resource at the Texas Advanced Computing Center) during the second year. These investigations are expected to illuminate the potential as well as the limitations of running facility scale production services in the cloud. The work includes running parallel equivalent cloud-based services to on premises services and includes: data serving via ftp from a large data store, operation of a metadata database, production scale processing of multiple months of geodetic data, web services delivery of quality checked data and products, large-scale compute services for event post-processing, and serving real time data
Deja vu: The Unified Command Plan of the Future Revisited
2011-05-19
Approved for Public Release; Distribution is Unlimited Déjà vu : The Unified Command Plan of the Future Revisited A Monograph by Lieutenant...DD-MM-YYYY) 19-05-2011 2. REPORT TYPE Monograph 3. DATES COVERED (From - To) JUL 2010 – MAY 2011 4. TITLE AND SUBTITLE Déjà vu : The Unified...i SCHOOL OF ADVANCED MILITARY STUDIES MONOGRAPH APPROVAL Lieutenant Colonel Edward Francis Martignetti Title of Monograph: Déjà vu : The Unified
Crowell, Brendan; Schmidt, David; Bodin, Paul; Vidale, John; Gomberg, Joan S.; Hartog, Renate; Kress, Victor; Melbourne, Tim; Santillian, Marcelo; Minson, Sarah E.; Jamison, Dylan
2016-01-01
A prototype earthquake early warning (EEW) system is currently in development in the Pacific Northwest. We have taken a two‐stage approach to EEW: (1) detection and initial characterization using strong‐motion data with the Earthquake Alarm Systems (ElarmS) seismic early warning package and (2) the triggering of geodetic modeling modules using Global Navigation Satellite Systems data that help provide robust estimates of large‐magnitude earthquakes. In this article we demonstrate the performance of the latter, the Geodetic First Approximation of Size and Time (G‐FAST) geodetic early warning system, using simulated displacements for the 2001Mw 6.8 Nisqually earthquake. We test the timing and performance of the two G‐FAST source characterization modules, peak ground displacement scaling, and Centroid Moment Tensor‐driven finite‐fault‐slip modeling under ideal, latent, noisy, and incomplete data conditions. We show good agreement between source parameters computed by G‐FAST with previously published and postprocessed seismic and geodetic results for all test cases and modeling modules, and we discuss the challenges with integration into the U.S. Geological Survey’s ShakeAlert EEW system.
A unified view of "how allostery works".
Tsai, Chung-Jung; Nussinov, Ruth
2014-02-01
The question of how allostery works was posed almost 50 years ago. Since then it has been the focus of much effort. This is for two reasons: first, the intellectual curiosity of basic science and the desire to understand fundamental phenomena, and second, its vast practical importance. Allostery is at play in all processes in the living cell, and increasingly in drug discovery. Many models have been successfully formulated, and are able to describe allostery even in the absence of a detailed structural mechanism. However, conceptual schemes designed to qualitatively explain allosteric mechanisms usually lack a quantitative mathematical model, and are unable to link its thermodynamic and structural foundations. This hampers insight into oncogenic mutations in cancer progression and biased agonists' actions. Here, we describe how allostery works from three different standpoints: thermodynamics, free energy landscape of population shift, and structure; all with exactly the same allosteric descriptors. This results in a unified view which not only clarifies the elusive allosteric mechanism but also provides structural grasp of agonist-mediated signaling pathways, and guides allosteric drug discovery. Of note, the unified view reasons that allosteric coupling (or communication) does not determine the allosteric efficacy; however, a communication channel is what makes potential binding sites allosteric.
DataSpread: Unifying Databases and Spreadsheets.
Bendre, Mangesh; Sun, Bofan; Zhang, Ding; Zhou, Xinyan; Chang, Kevin ChenChuan; Parameswaran, Aditya
2015-08-01
Spreadsheet software is often the tool of choice for ad-hoc tabular data management, processing, and visualization, especially on tiny data sets. On the other hand, relational database systems offer significant power, expressivity, and efficiency over spreadsheet software for data management, while lacking in the ease of use and ad-hoc analysis capabilities. We demonstrate DataSpread, a data exploration tool that holistically unifies databases and spreadsheets. It continues to offer a Microsoft Excel-based spreadsheet front-end, while in parallel managing all the data in a back-end database, specifically, PostgreSQL. DataSpread retains all the advantages of spreadsheets, including ease of use, ad-hoc analysis and visualization capabilities, and a schema-free nature, while also adding the advantages of traditional relational databases, such as scalability and the ability to use arbitrary SQL to import, filter, or join external or internal tables and have the results appear in the spreadsheet. DataSpread needs to reason about and reconcile differences in the notions of schema, addressing of cells and tuples, and the current "pane" (which exists in spreadsheets but not in traditional databases), and support data modifications at both the front-end and the back-end. Our demonstration will center on our first and early prototype of the DataSpread, and will give the attendees a sense for the enormous data exploration capabilities offered by unifying spreadsheets and databases.
SO(10) supersymmetric grand unified theories
Dermisek, Radovan
The origin of the fermion mass hierarchy is one of the most challenging problems in elementary particle physics. In the standard model fermion masses and mixing angles are free parameters. Supersymmetric grand unified theories provide a beautiful framework for physics beyond the standard model. In addition to gauge coupling unification these theories provide relations between quark and lepton masses within families, and with additional family symmetry the hierarchy between families can be generated. We present a predictive SO(10) supersymmetric grand unified model with D 3 x U(1) family symmetry. The hierarchy in fermion masses is generated by the family symmetry breaking D 3 x U(1) → ZN → nothing. This model fits the low energy data in the charged fermion sector quite well. We discuss the prediction of this model for the proton lifetime in light of recent SuperKamiokande results and present a clear picture of the allowed spectra of supersymmetric particles. Finally, the detailed discussion of the Yukawa coupling unification of the third generation particles is provided. We find a narrow region is consistent with t, b, tau Yukawa unification for mu > 0 (suggested by b → sgamma and the anomalous magnetic moment of the muon) with A0 ˜ -1.9m16, m10 ˜ 1.4m16, m16 ≳ 1200 GeV and mu, M1/2 ˜ 100--500 GeV. Demanding Yukawa unification thus makes definite predictions for Higgs and sparticle masses.
Unifying hydrotropy under Gibbs phase rule.
Shimizu, Seishi; Matubayasi, Nobuyuki
2017-09-13
The task of elucidating the mechanism of solubility enhancement using hydrotropes has been hampered by the wide variety of phase behaviour that hydrotropes can exhibit, encompassing near-ideal aqueous solution, self-association, micelle formation, and micro-emulsions. Instead of taking a field guide or encyclopedic approach to classify hydrotropes into different molecular classes, we take a rational approach aiming at constructing a unified theory of hydrotropy based upon the first principles of statistical thermodynamics. Achieving this aim can be facilitated by the two key concepts: (1) the Gibbs phase rule as the basis of classifying the hydrotropes in terms of the degrees of freedom and the number of variables to modulate the solvation free energy; (2) the Kirkwood-Buff integrals to quantify the interactions between the species and their relative contributions to the process of solubilization. We demonstrate that the application of the two key concepts can in principle be used to distinguish the different molecular scenarios at work under apparently similar solubility curves observed from experiments. In addition, a generalization of our previous approach to solutes beyond dilution reveals the unified mechanism of hydrotropy, driven by a strong solute-hydrotrope interaction which overcomes the apparent per-hydrotrope inefficiency due to hydrotrope self-clustering.
A unified dynamics for micro and macrosystems
International Nuclear Information System (INIS)
Ghirardi, G.C.; Rimini, A.; Weber, T.
1985-12-01
An explicit model allowing a unified description of micro and macrosystems is exhibited. Firstly, a modified quantum dynamics for the description of macroobjects is constructed and it is shown that it forbids the occurrence of linear superpositions of states localized in far away spatial regions and induces an evolution agreeing with classical mechanics. This dynamics also allows a description of the evolution in terms of trajectories. To set up a unified description of all physical phenomena, a modification of the dynamics, with respect to the standard Hamiltonian one, is then postulated also for microscopic systems. It is shown that one can consistently deduce from it the previously considered dynamics for the centre of mass of macroscopic systems. Choosing in an appropriate way the parameters of the so obtained model one can show that the standard quantum theory for microobjects, the quantum mechanical wave packet reduction with fixed pointer positions, and the classical behaviour for macroobjects can be all derived in a consistent way. Moreover, in the case of a macroscopic system one can obtain, by means of appropriate approximations, a description of the evolution in terms of a phase-space density distribution obeying a Fokker-Planck diffusion equation. (author)
Group theory for unified model building
International Nuclear Information System (INIS)
Slansky, R.
1981-01-01
The results gathered here on simple Lie algebras have been selected with attention to the needs of unified model builders who study Yang-Mills theories based on simple, local-symmetry groups that contain as a subgroup the SUsup(w) 2 x Usup(w) 1 x SUsup(c) 3 symmetry of the standard theory of electromagnetic, weak, and strong interactions. The major topics include, after a brief review of the standard model and its unification into a simple group, the use of Dynkin diagrams to analyze the structure of the group generators and to keep track of the weights (quantum numbers) of the representation vectors; an analysis of the subgroup structure of simple groups, including explicit coordinatizations of the projections in weight space; lists of representations, tensor products and branching rules for a number of simple groups; and other details about groups and their representations that are often helpful for surveying unified models, including vector-coupling coefficient calculations. Tabulations of representations, tensor products, and branching rules for E 6 , SO 10 , SU 6 , F 4 , SO 9 , SO 5 , SO 8 , SO 7 , SU 4 , E 7 , E 8 , SU 8 , SO 14 , SO 18 , SO 22 , and for completeness, SU 3 are included. (These tables may have other applications.) Group-theoretical techniques for analyzing symmetry breaking are described in detail and many examples are reviewed, including explicit parameterizations of mass matrices. (orig.)
A Unified Theoretical Framework for Cognitive Sequencing.
Savalia, Tejas; Shukla, Anuj; Bapi, Raju S
2016-01-01
The capacity to sequence information is central to human performance. Sequencing ability forms the foundation stone for higher order cognition related to language and goal-directed planning. Information related to the order of items, their timing, chunking and hierarchical organization are important aspects in sequencing. Past research on sequencing has emphasized two distinct and independent dichotomies: implicit vs. explicit and goal-directed vs. habits. We propose a theoretical framework unifying these two streams. Our proposal relies on brain's ability to implicitly extract statistical regularities from the stream of stimuli and with attentional engagement organizing sequences explicitly and hierarchically. Similarly, sequences that need to be assembled purposively to accomplish a goal require engagement of attentional processes. With repetition, these goal-directed plans become habits with concomitant disengagement of attention. Thus, attention and awareness play a crucial role in the implicit-to-explicit transition as well as in how goal-directed plans become automatic habits. Cortico-subcortical loops basal ganglia-frontal cortex and hippocampus-frontal cortex loops mediate the transition process. We show how the computational principles of model-free and model-based learning paradigms, along with a pivotal role for attention and awareness, offer a unifying framework for these two dichotomies. Based on this framework, we make testable predictions related to the potential influence of response-to-stimulus interval (RSI) on developing awareness in implicit learning tasks.
A Unified Theoretical Framework for Cognitive Sequencing
Directory of Open Access Journals (Sweden)
Tejas Savalia
2016-11-01
Full Text Available The capacity to sequence information is central to human performance. Sequencing ability forms the foundation stone for higher order cognition related to language and goal-directed planning. Information related to the order of items, their timing, chunking and hierarchical organization are important aspects in sequencing. Past research on sequencing has emphasized two distinct and independent dichotomies: implicit versus explicit and goal-directed versus habits. We propose a theoretical framework unifying these two streams. Our proposal relies on brain's ability to implicitly extract statistical regularities from the stream of stimuli and with attentional engagement organizing sequences explicitly and hierarchically. Similarly, sequences that need to be assembled purposively to accomplish a goal require engagement of attentional processes. With repetition, these goal-directed plans become habits with concomitant disengagement of attention. Thus attention and awareness play a crucial role in the implicit-to-explicit transition as well as in how goal-directed plans become automatic habits. Cortico-subcortical loops ─ basal ganglia-frontal cortex and hippocampus-frontal cortex loops ─ mediate the transition process. We show how the computational principles of model-free and model-based learning paradigms, along with a pivotal role for attention and awareness, offer a unifying framework for these two dichotomies. Based on this framework, we make testable predictions related to the potential influence of response-to-stimulus interval (RSI on developing awareness in implicit learning tasks.
Aspects of extra dimensional supersymmetric unified theories
International Nuclear Information System (INIS)
Fichet, S.
2011-09-01
The purpose of this work is to investigate Grand Unified Theories (GUTs) and to make the link with passed and upcoming experiments. The structure of this thesis is as follows. In the first chapter, we will briefly review the sequence of arguments leading to the Higgs mechanism, then to the different concepts underlying physics beyond the Standard Model, and to the paradigm of extra dimensional supersymmetric grand unified theories. At each level of the argumentation, we will mention the different solutions available. The second chapter introduces more formally supersymmetry and extra dimensions, focusing in particular on the aspects of symmetry breaking. Then, in the third chapter, we present in details the two frameworks of extra dimensional theories in which we worked, called supersymmetric gauge-Higgs unification (GHU) and holographic grand unification (HGU) as well as the developments and modifications we brought to them. The fourth chapter is devoted to the low energy viability of the GHU framework, as well as its phenomenological implications. The fifth chapter presents a more generic study of the property of GUT-scale degenerate Higgs mass matrix, common to both frameworks. Finally, the sixth chapter is devoted to the viability and phenomenological implications of the HGU framework, with special emphasis on lepton flavour violation. This quantitative study takes properly into account effects of matrix anarchy, as well as exact flavour observables. The results obtained should generalize, at least qualitatively, to any other model with similar localization and supersymmetry breaking features
Learned Compact Local Feature Descriptor for Tls-Based Geodetic Monitoring of Natural Outdoor Scenes
Gojcic, Z.; Zhou, C.; Wieser, A.
2018-05-01
The advantages of terrestrial laser scanning (TLS) for geodetic monitoring of man-made and natural objects are not yet fully exploited. Herein we address one of the open challenges by proposing feature-based methods for identification of corresponding points in point clouds of two or more epochs. We propose a learned compact feature descriptor tailored for point clouds of natural outdoor scenes obtained using TLS. We evaluate our method both on a benchmark data set and on a specially acquired outdoor dataset resembling a simplified monitoring scenario where we successfully estimate 3D displacement vectors of a rock that has been displaced between the scans. We show that the proposed descriptor has the capacity to generalize to unseen data and achieves state-of-the-art performance while being time efficient at the matching step due the low dimension.
Directory of Open Access Journals (Sweden)
Ochałek Agnieszka
2018-01-01
Full Text Available The significant part of the hydrography is bathymetry, which is the empirical part of it. Bathymetry is the study of underwater depth of waterways and reservoirs, and graphic presentation of measured data in form of bathymetric maps, cross-sections and three-dimensional bottom models. The bathymetric measurements are based on using Global Positioning System and devices for hydrographic measurements – an echo sounder and a side sonar scanner. In this research authors focused on introducing the case of obtaining and processing the bathymetrical data, building numerical bottom models of two post-mining reclaimed water reservoirs: Dwudniaki Lake in Wierzchosławice and flooded quarry in Zabierzów. The report includes also analysing data from still operating mining water reservoirs located in Poland to depict how bathymetry can be used in mining industry. The significant issue is an integration of bathymetrical data and geodetic data from tachymetry, terrestrial laser scanning measurements.
Ochałek, Agnieszka; Lipecki, Tomasz; Jaśkowski, Wojciech; Jabłoński, Mateusz
2018-03-01
The significant part of the hydrography is bathymetry, which is the empirical part of it. Bathymetry is the study of underwater depth of waterways and reservoirs, and graphic presentation of measured data in form of bathymetric maps, cross-sections and three-dimensional bottom models. The bathymetric measurements are based on using Global Positioning System and devices for hydrographic measurements - an echo sounder and a side sonar scanner. In this research authors focused on introducing the case of obtaining and processing the bathymetrical data, building numerical bottom models of two post-mining reclaimed water reservoirs: Dwudniaki Lake in Wierzchosławice and flooded quarry in Zabierzów. The report includes also analysing data from still operating mining water reservoirs located in Poland to depict how bathymetry can be used in mining industry. The significant issue is an integration of bathymetrical data and geodetic data from tachymetry, terrestrial laser scanning measurements.
Processing of a geodetic network determined in ETRS-89 with application of different cofactors
Directory of Open Access Journals (Sweden)
Slavomír Labant
2012-12-01
Full Text Available At present, manufacturers characterize the accuracy of vectors measured by the static method of GNSS technology usingrelationship 5 mm + 1⋅ D ppm . The advantage of the GNSS system over other terrestrial technologies is that it is not affectedby uncertainties in the ground layers of the atmosphere. The paper presents experimental measurement of the 3D geodetic network usingthe technology of global navigation satellite systems, processing and analysis of measurements taken at the Čierny Váh pumping hydropowerstation. Observations were carried out in July 2008. The aim of the paper is to assess parameters used in the model to estimateparameters of the first and second order of the network structures.
Optimization of observation plan based on the stochastic characteristics of the geodetic network
Directory of Open Access Journals (Sweden)
Pachelski Wojciech
2016-06-01
Full Text Available Optimal design of geodetic network is a basic subject of many engineering projects. An observation plan is a concluding part of the process. Any particular observation within the network has through adjustment a different contribution and impact on values and accuracy characteristics of unknowns. The problem of optimal design can be solved by means of computer simulation. This paper presents a new method of simulation based on sequential estimation of individual observations in a step-by-step manner, by means of the so-called filtering equations. The algorithm aims at satisfying different criteria of accuracy according to various interpretations of the covariance matrix. Apart of them, the optimization criterion is also amount of effort, defined as the minimum number of observations required.
Geodetic Imaging: Expanding the Boundaries of Geodesy in the 21st Century
Fernandez Diaz, J. C.; Carter, W. E.; Shrestha, R. L.; Glennie, C. L.
2013-12-01
High resolution (sub-meter) geodetic images covering tens to thousands of square kilometers have extended the boundaries of geodesy into related areas of the earth sciences, such as geomorphology and geodynamics, during the past decade, to archaeological exploration and site mapping during the past few years, and are now poised to transform studies of flora and fauna in the more remote regions of the world. Geodetic images produced from airborne laser scanning (ALS), a.k.a. airborne light detection and ranging (LiDAR) have proven transformative to the modern practice of geomorphology where researchers have used decimeter resolution digital elevation models (DEMs) to determine the spatial frequencies of evenly spaced features in terrain, and developed models and mathematical equations to explain how the terrain evolved to its present state and how it is expected to change in the future (Perron et al., 2009). In geodynamics researchers have used ';before' and ';after' geodetic images of the terrain near earthquakes, such as the 2010 El Mayor-Cucapah Earthquake, to quantify surface displacements and suggest models to explain the observed deformations (Oskin et. al., 2012). In archaeology, the ability of ALS to produce ';bare earth' DEMs of terrain covered with dense vegetation, including even tropical rain forests, has revolutionized the study of archaeology in highly forested areas, finding ancient structures and human modifications of landscapes not discovered by archaeologists working at sites for decades (Chase et al., 2011 & Evans et al., 2013), and finding previously unknown ruins in areas that ground exploration has not been able to penetrate since the arrival of the conquistadors in the new world in the 17th century (Carter et al., 2012). The improved spatial resolution and ability of the third generation ALS units to obtain high resolution bare earth DEMs and canopy models in areas covered in dense forests, brush, and even shallow water (steams, lakes, and
Geodetic measurement of deformation east of the San Andreas Fault in Central California
Sauber, Jeanne; Solomon, Sean C.; Lisowski, Michael
1988-01-01
The shear strain rates in the Diablo Range of California have been calculated, and the slip rate along the Calaveras and Paicines faults in Central California have been estimated, on the basis of triangulation and trilateration data from two geodetic networks located between the western edge of the Great Valley and the San Andreas Fault. The orientation of the principal compressive strain predicted from the azimuth of the major structures in the region is N 25 deg E, leading to an average shear strain value that corresponds to a relative shortening rate of 4.5 + or - 2.4 mm/yr. It is inferred that the measured strain is due to compression across the fold of this area. The hypothesized uniform, fault-normal compression within the Coast Ranges is not supported by these results.
Directory of Open Access Journals (Sweden)
Jouni Peltoniemi
2009-05-01
Full Text Available The design, operation, and properties of the Finnish Geodetic Institute Field Goniospectrometer (FIGIFIGO are presented. FIGIFIGO is a portable instrument for the measurement of surface Bidirectional Reflectance Factor (BRF for samples with diameters of 10 – 50 cm. A set of polarising optics enable the measurement of linearly polarised BRF over the full solar spectrum (350 – 2,500 nm. FIGIFIGO is designed mainly for field operation using sunlight, but operation in a laboratory environment is also possible. The acquired BRF have an accuracy of 1 – 5% depending on wavelength, sample properties, and measurement conditions. The angles are registered at accuracies better than 2°. During 2004 – 2008, FIGIFIGO has been used in the measurement of over 150 samples, all around northern Europe. The samples concentrate mostly on boreal forest understorey, snow, urban surfaces, and reflectance calibration surfaces.
A geodetic matched-filter search for slow slip with application to the Mexico subduction zone
Rousset, B.; Campillo, M.; Lasserre, C.; Frank, W.; Cotte, N.; Walpersdorf, A.; Socquet, A.; Kostoglodov, V.
2017-12-01
Since the discovery of slow slip events, many methods have been successfully applied to model obvious transient events in geodetic time series, such as the widely used network strain filter. Independent seismological observations of tremors or low frequency earthquakes and repeating earthquakes provide evidence of low amplitude slow deformation but do not always coincide with clear occurrences of transient signals in geodetic time series. Here, we aim to extract the signal corresponding to slow slips hidden in the noise of GPS time series, without using information from independent datasets. We first build a library of synthetic slow slip event templates by assembling a source function with Green's functions for a discretized fault. We then correlate the templates with post-processed GPS time series. Once the events have been detected in time, we estimate their duration T and magnitude Mw by modelling a weighted stack of GPS time series. An analysis of synthetic time series shows that this method is able to resolve the correct timing, location, T and Mw of events larger than Mw 6.0 in the context of the Mexico subduction zone. Applied on a real data set of 29 GPS time series in the Guerrero area from 2005 to 2014, this technique allows us to detect 28 transient events from Mw 6.3 to 7.2 with durations that range from 3 to 39 days. These events have a dominant recurrence time of 40 days and are mainly located at the down dip edges of the Mw > 7.5 SSEs.
A geodetic matched filter search for slow slip with application to the Mexico subduction zone
Rousset, B.; Campillo, M.; Lasserre, C.; Frank, W. B.; Cotte, N.; Walpersdorf, A.; Socquet, A.; Kostoglodov, V.
2017-12-01
Since the discovery of slow slip events, many methods have been successfully applied to model obvious transient events in geodetic time series, such as the widely used network strain filter. Independent seismological observations of tremors or low-frequency earthquakes and repeating earthquakes provide evidence of low-amplitude slow deformation but do not always coincide with clear occurrences of transient signals in geodetic time series. Here we aim to extract the signal corresponding to slow slips hidden in the noise of GPS time series, without using information from independent data sets. We first build a library of synthetic slow slip event templates by assembling a source function with Green's functions for a discretized fault. We then correlate the templates with postprocessed GPS time series. Once the events have been detected in time, we estimate their duration T and magnitude Mw by modeling a weighted stack of GPS time series. An analysis of synthetic time series shows that this method is able to resolve the correct timing, location, T, and Mw of events larger than Mw 6 in the context of the Mexico subduction zone. Applied on a real data set of 29 GPS time series in the Guerrero area from 2005 to 2014, this technique allows us to detect 28 transient events from Mw 6.3 to 7.2 with durations that range from 3 to 39 days. These events have a dominant recurrence time of 40 days and are mainly located at the downdip edges of the Mw>7.5 slow slip events.
Results from the Geodetic Observatory TIGO due to the Mw 8.8 Earthquake
Hase, H.; Böer, A.; Sierk, B.; Ihde, J.; Weber, G.; Wilmes, H.; Falk, R.; Hessels, U.; Neumaier, P.; Söhne, W.; Wziontek, H.; Engelhard, G.; Sobarzo, S.; Cifuentes, O.; Guaitiao, C.; Cona, I.; Avendaño, M.; Herrera, C.; Mora, V.; Fernandez, A.; Oñate, E.; Zaror, P.; Pedreros, F.; Zapata, O.
2010-12-01
The Geodetic Observatory TIGO is unique in Latin America. With its sensors and instruments it defines a reference point in the time, space and gravity field domain. Its operation started in 2002, for which reason data series documented the preseismic situation very well. With the Mw 8.8 earthquake on February 27, 2010, the entire observatory was exposed to strong motions due to its closeness to the epicenter. Since then the postseismic behaviour of the subduction zone can be studied and compared with the preseismic situation. TIGO provided continuous GPS/GLONASS data with 1s samples which give an insight to the mechanism of the decoupling of the Nazca and the South-American plate. The displacement of more than 3m had a duration of 30s at the beginning of the 147s duration of the earthquake. The displacement could be confirmed afterwards with VLBI and SLR methods. TIGO used its absolute gravity meter in an unusual way with weekly measurements on the same monument. These data show an irregularity during the last 3 weeks before the earthquake. Finally the postseismic movement to the west triggered by the earthquake and registered by geodetic space techniques indicate that the western expansion of the South-American plate did not stop yet. The pre- and post-seismic displacement vectors differ by less than 180° which might be explained by a fractional strike slip in the mega thrust. The coincidence of the epicenter with one of the keystations for global reference frames showed deficiencies by the linear modelling of tectonical movements in terrestial reference frames. This problem calls for near-real time reference frames.
Ebner, R.; Featherstone, W. E.
2008-09-01
Establishing geodetic control networks for subsequent surveys can be a costly business, even when using GPS. Multiple stations should be occupied simultaneously and post-processed with scientific software. However, the free availability of online GPS precise point positioning (PPP) post-processing services offer the opportunity to establish a whole geodetic control network with just one dual-frequency receiver and one field crew. To test this idea, we compared coordinates from a moderate-sized (~550 km by ~440 km) geodetic network of 46 points over part of south-western Western Australia, which were processed both with the Bernese v5 scientific software and with the CSRS (Canadian Spatial Reference System) PPP free online service. After rejection of five stations where the antenna type was not recognised by CSRS, the PPP solutions agreed on average with the Bernese solutions to 3.3 mm in east, 4.8 mm in north and 11.8 mm in height. The average standard deviations of the Bernese solutions were 1.0 mm in east, 1.2 mm in north and 6.2 mm in height, whereas for CSRS they were 3.9 mm in east, 1.9 mm in north and 7.8 mm in height, reflecting the inherently lower precision of PPP. However, at the 99% confidence level, only one CSRS solution was statistically different to the Bernese solution in the north component, due to a data interruption at that site. Nevertheless, PPP can still be used to establish geodetic survey control, albeit with a slightly lower quality because of the larger standard deviations. This approach may be of particular benefit in developing countries or remote regions, where geodetic infrastructure is sparse and would not normally be established without this approach.
76 FR 76060 - Final Flood Elevation Determinations
2011-12-06
... Illinois Route 34. * National Geodetic Vertical Datum. + North American Vertical Datum. Depth in feet above... Vertical Datum. + North American Vertical Datum. Depth in feet above ground. [caret] Mean Sea Level..., Michigan (All Jurisdictions) Docket No.: FEMA-B-1089 Alward Drain At the confluence with +615 Charter...
Hilltop supernatural inflation and SUSY unified models
Kohri, Kazunori; Lim, C. S.; Lin, Chia-Min; Mimura, Yukihiro
2014-01-01
In this paper, we consider high scale (100TeV) supersymmetry (SUSY) breaking and realize the idea of hilltop supernatural inflation in concrete particle physics models based on flipped-SU(5)and Pati-Salam models in the framework of supersymmetric grand unified theories (SUSY GUTs). The inflaton can be a flat direction including right-handed sneutrino and the waterfall field is a GUT Higgs. The spectral index is ns = 0.96 which fits very well with recent data by PLANCK satellite. There is no both thermal and non-thermal gravitino problems. Non-thermal leptogenesis can be resulted from the decay of right-handed sneutrino which plays (part of) the role of inflaton.
Hilltop supernatural inflation and SUSY unified models
Energy Technology Data Exchange (ETDEWEB)
Kohri, Kazunori [Cosmophysics Group, Theory Center, IPNS KEK, and The Graduate University for Advanced Studies (Sokendai), 1-1 Oho, Tsukuba, 305-0801 (Japan); Lim, C.S. [Department of Mathematics, Tokyo Woman' s Christian University, Tokyo, 167-8585 (Japan); Lin, Chia-Min [Department of Physics, Chuo University, Bunkyo-ku, Tokyo, 112 (Japan); Mimura, Yukihiro, E-mail: kohri@post.kek.jp, E-mail: lim@lab.twcu.ac.jp, E-mail: lin@chuo-u.ac.jp, E-mail: mimura@hep1.phys.ntu.edu.tw [Department of Physics, National Taiwan University, Taipei, 10617 Taiwan (China)
2014-01-01
In this paper, we consider high scale (100TeV) supersymmetry (SUSY) breaking and realize the idea of hilltop supernatural inflation in concrete particle physics models based on flipped-SU(5)and Pati-Salam models in the framework of supersymmetric grand unified theories (SUSY GUTs). The inflaton can be a flat direction including right-handed sneutrino and the waterfall field is a GUT Higgs. The spectral index is n{sub s} = 0.96 which fits very well with recent data by PLANCK satellite. There is no both thermal and non-thermal gravitino problems. Non-thermal leptogenesis can be resulted from the decay of right-handed sneutrino which plays (part of) the role of inflaton.
Unifying flipped SU(5) in five dimensions
International Nuclear Information System (INIS)
Barr, S.M.; Dorsner, Ilja
2002-01-01
It is shown that embedding a four-dimensional flipped SU(5) model in a five-dimensional SO(10) model preserves the best features of both flipped SU(5) and SO(10). The missing partner mechanism, which naturally achieves both doublet-triplet splitting and suppression of d=5 proton decay operators, is realized as in flipped SU(5), while the gauge couplings are unified as in SO(10). The masses of down quarks and charged leptons, which are independent in flipped SU(5), are related by the SO(10). Distinctive patterns of quark and lepton masses can result. The gaugino mass M 1 is independent of M 3 and M 2 , which are predicted to be equal
Covariant extensions and the nonsymmetric unified field
International Nuclear Information System (INIS)
Borchsenius, K.
1976-01-01
The problem of generally covariant extension of Lorentz invariant field equations, by means of covariant derivatives extracted from the nonsymmetric unified field, is considered. It is shown that the contracted curvature tensor can be expressed in terms of a covariant gauge derivative which contains the gauge derivative corresponding to minimal coupling, if the universal constant p, characterizing the nonsymmetric theory, is fixed in terms of Planck's constant and the elementary quantum of charge. By this choice the spinor representation of the linear connection becomes closely related to the spinor affinity used by Infeld and Van Der Waerden (Sitzungsber. Preuss. Akad. Wiss. Phys. Math. Kl.; 9:380 (1933)) in their generally covariant formulation of Dirac's equation. (author)
SUGERE - a unified system for waste management
International Nuclear Information System (INIS)
Silva, Eliane Magalhaes Pereira da; Vasconcelos, Vanderley de; Senne Junior, Murillo; Jordao, Elizabete
2005-01-01
Generation and disposal of wastes has been responsible for many economical, ecological and public health problems. In order to manage hazardous wastes in an environment friendly manner, many technical and administrative procedures should be implemented, including prevention, control of generation, and final disposal. A software named SUGERE - a unified system for waste management - is being developed. It is an easy to use tool that integrates all the steps involved in hazardous and radioactive waste management. This system is intended to help generators, transporters and owners of treatment, storage and disposal facilities to manage hazardous and radioactive wastes, by assuring compliance with environmental laws and consumer requirements. This paper presents the current status of the SUGERE software, developed using Borland Delphi package. The nuclear industry is used as a reference for developing this work. (author)
UniPOPS: Unified data reduction suite
Maddalena, Ronald J.; Garwood, Robert W.; Salter, Christopher J.; Stobie, Elizabeth B.; Cram, Thomas R.; Morgan, Lorrie; Vance, Bob; Hudson, Jerome
2015-03-01
UniPOPS, a suite of programs and utilities developed at the National Radio Astronomy Observatory (NRAO), reduced data from the observatory's single-dish telescopes: the Tucson 12-m, the Green Bank 140-ft, and archived data from the Green Bank 300-ft. The primary reduction programs, 'line' (for spectral-line reduction) and 'condar' (for continuum reduction), used the People-Oriented Parsing Service (POPS) as the command line interpreter. UniPOPS unified previous analysis packages and provided new capabilities; development of UniPOPS continued within the NRAO until 2004 when the 12-m was turned over to the Arizona Radio Observatory (ARO). The submitted code is version 3.5 from 2004, the last supported by the NRAO.
A unified grand tour of theoretical physics
Lawrie, Ian D
2013-01-01
A Unified Grand Tour of Theoretical Physics invites its readers to a guided exploration of the theoretical ideas that shape our contemporary understanding of the physical world at the fundamental level. Its central themes, comprising space-time geometry and the general relativistic account of gravity, quantum field theory and the gauge theories of fundamental forces, and statistical mechanics and the theory of phase transitions, are developed in explicit mathematical detail, with an emphasis on conceptual understanding. Straightforward treatments of the standard models of particle physics and cosmology are supplemented with introductory accounts of more speculative theories, including supersymmetry and string theory. This third edition of the Tour includes a new chapter on quantum gravity, focusing on the approach known as Loop Quantum Gravity, while new sections provide extended discussions of topics that have become prominent in recent years, such as the Higgs boson, massive neutrinos, cosmological perturba...
A Unifying Theory of Biological Function.
van Hateren, J H
2017-01-01
A new theory that naturalizes biological function is explained and compared with earlier etiological and causal role theories. Etiological (or selected effects) theories explain functions from how they are caused over their evolutionary history. Causal role theories analyze how functional mechanisms serve the current capacities of their containing system. The new proposal unifies the key notions of both kinds of theories, but goes beyond them by explaining how functions in an organism can exist as factors with autonomous causal efficacy. The goal-directedness and normativity of functions exist in this strict sense as well. The theory depends on an internal physiological or neural process that mimics an organism's fitness, and modulates the organism's variability accordingly. The structure of the internal process can be subdivided into subprocesses that monitor specific functions in an organism. The theory matches well with each intuition on a previously published list of intuited ideas about biological functions, including intuitions that have posed difficulties for other theories.
Hilltop supernatural inflation and SUSY unified models
International Nuclear Information System (INIS)
Kohri, Kazunori; Lim, C.S.; Lin, Chia-Min; Mimura, Yukihiro
2014-01-01
In this paper, we consider high scale (100TeV) supersymmetry (SUSY) breaking and realize the idea of hilltop supernatural inflation in concrete particle physics models based on flipped-SU(5)and Pati-Salam models in the framework of supersymmetric grand unified theories (SUSY GUTs). The inflaton can be a flat direction including right-handed sneutrino and the waterfall field is a GUT Higgs. The spectral index is n s = 0.96 which fits very well with recent data by PLANCK satellite. There is no both thermal and non-thermal gravitino problems. Non-thermal leptogenesis can be resulted from the decay of right-handed sneutrino which plays (part of) the role of inflaton
Centrally managed unified shared virtual address space
Wilkes, John
2018-02-13
Systems, apparatuses, and methods for managing a unified shared virtual address space. A host may execute system software and manage a plurality of nodes coupled to the host. The host may send work tasks to the nodes, and for each node, the host may externally manage the node's view of the system's virtual address space. Each node may have a central processing unit (CPU) style memory management unit (MMU) with an internal translation lookaside buffer (TLB). In one embodiment, the host may be coupled to a given node via an input/output memory management unit (IOMMU) interface, where the IOMMU frontend interface shares the TLB with the given node's MMU. In another embodiment, the host may control the given node's view of virtual address space via memory-mapped control registers.
Cosmological implications of grand unified theories
International Nuclear Information System (INIS)
Nanopoulos, D.V.
1982-01-01
These lectures, mainly devoted to the cosmological implications of GUTs, also include the essential ingredients of GUTs and some of their important applications to particle physics. Section 1 contains some basic points concerning the structure of the standard strong and electroweak interactions prior to grand unification. A detailed expose of GUTs is attempted in sect. 2, including their basci principles and their consequences for particle physics. The minimal, simplest GUT, SU 5 is analysed in some detail and it will be used throughout these lectures as the GUT prototype. Finally, sect. 3 contains the most important cosmological implications of GUTs, including baryon number generation in the early Universe (in rather lengthy detail), dissipative processes in the very early Universe, grand unified monopoles, etc. (orig./HSI)
OPC from data access to unified architecture
Lange, Jurgen; Burke, Thomas J
2010-01-01
OPC stands for Openness, Productivity, and Collaboration, symbolizing the new possibilities opening up in automation technology. The main objective of the new OPC generation Unified Architecture is to facilitate global interoperability and to define an information and data-exchange mechanism that is service oriented, multivendor, and cross-platform capable – from the field device on the shop floor to the ERP system on the factory level. This book includes information on: - the birth, objectives, and fundamentals of OPC and OPC UA, - the technical specifications that currently exist and those that are in preparation, - the procedures for designing and implementing components, - a transparent presentation of the technology through application possibilities and examples, and - the outlook for the future of OPC and OPC UA. Important perspectives and updates in this new edition include - the new era and the exciting application possibilities developing with OPC UA, - the new OPC UA specifications, - the devel...
Introduction to Grand Unified Theories. 12
International Nuclear Information System (INIS)
Wali, K.C.
1989-01-01
This chapter presents an introduction into Grand Unified Theories. After a discussion of the general features to be expected in any such theory, and of the motivations for them, a detailed presentation of SU(5) theory is given. The group structures, particle multiplets, gauge and Higgs bosons are explained. The two stages of spontaneous symmetry breaking via the Higgs model, are calculated individually and in combination. Fermion mass matrices and relations between quark and lepton masses are derived. predictions of SU(5) theory, calculated using renormalization group methods, are derived. The chapter ends with discussions that bring together particle physics and cosmology, including the baryon asymmetry problem, phase transitions in the very early universe, and singularities like domain walls, vortex lines and monopoles. (author). 9 refs.; 4 figs.; 5 tabs
On the History of Unified Field Theories
Directory of Open Access Journals (Sweden)
Goenner Hubert F.M.
2004-01-01
Full Text Available This article is intended to give a review of the history of the classical aspects of unified field theories in the 20th century. It includes brief technical descriptions of the theories suggested, short biographical notes concerning the scientists involved, and an extensive bibliography. The present first installment covers the time span between 1914 and 1933, i.e., when Einstein was living and working in Berlin - with occasional digressions into other periods. Thus, the main theme is the unification of the electromagnetic and gravitational fields augmented by short-lived attempts to include the matter field described by Schrödinger's or Dirac's equations. While my focus lies on the conceptual development of the field, by also paying attention to the interaction of various schools of mathematicians with the research done by physicists, some prosopocraphical remarks are included.
Supersymmetric grand unified theories and cosmology
International Nuclear Information System (INIS)
Lazarides, G.; Shafi, Q.
1983-01-01
By examining the behavior of supersymmetric grand unified theories (GUT's) in the very early universe we find two classes of realistic models. In one of them supersymmetry is broken at or near superheavy GUT scale. The cosmological implications of such models are expected to be similar to those of nonsupersymmetric GUT's. In the second class of models, the superheavy GUT scale is related to the supersymmetry-breaking scale in the manner of Witten. Two types of cosmological scenarios appear possible in this case, either with or without an intermediate (new) inflationary phase. They can be experimentally distinguished, since the former predicts an absence and the latter an observable number density of superheavy monopoles. A mechanism for generating baryon asymmetry in such models is pointed out
A unified approach to the Darwin approximation
International Nuclear Information System (INIS)
Krause, Todd B.; Apte, A.; Morrison, P. J.
2007-01-01
There are two basic approaches to the Darwin approximation. The first involves solving the Maxwell equations in Coulomb gauge and then approximating the vector potential to remove retardation effects. The second approach approximates the Coulomb gauge equations themselves, then solves these exactly for the vector potential. There is no a priori reason that these should result in the same approximation. Here, the equivalence of these two approaches is investigated and a unified framework is provided in which to view the Darwin approximation. Darwin's original treatment is variational in nature, but subsequent applications of his ideas in the context of Vlasov's theory are not. We present here action principles for the Darwin approximation in the Vlasov context, and this serves as a consistency check on the use of the approximation in this setting
New ideas about unified field theory
International Nuclear Information System (INIS)
Gleiser, M.
1986-01-01
An outline of the physical concepts evolution is given from the ancient philosophers to the present time. With qualitative explanations about the meaning of the theories that is the milestones of these concepts evolution, it mentions the ideas which lead the studies to the conception of a unified field theory. Chronologically, it has brief information about the ideas of Laplace (mechanical determinism), Maxwell (the field concept), Einsten (the space-time structure), Heisenberg and Schroedinger (the quantum mechanics), Dirac (the relativistic quantum and the antiparticles), Gell-Mann (the quarks), Weinberg-Salam (Weak interactions and eletromagnetic unification), H. Georgi and S. Glashon (strong interactions plus Weinberg-Salam), Kaluza-Klein (a fifth space-time coordinate), and Zumino-Weiss (supersymmetry and supergravity). (G.D.F.) [pt
Preface to a GUT (Grand Unified Theory)
International Nuclear Information System (INIS)
Honig, W.
1982-01-01
A Grand Unified Theory (GUT) is proposed exhibiting relativistic invariance and based on a physical model for vacuum space consisting of the superposition of oppositely charged continuous fluids. Models for the photon, electron, neutrino, proton, etc., consist of separate unique variations in the relative densities of the fluids and their flow patterns. This GUT is also based on the use of transfinite axiomatic number forms and on a concept of metrical relativity which hopefully reconciles the many logical dichotomies in and between Special Relativity and Quantum Mechanics. These ideas result in a number of experimental proposals and predicted results which appear to be underivable from present paradigms, first among which is a physical model for the hidden variable of Quantum Mechanics. It is on these features that attention should rest. (Auth.)
Higgsless grand unified theory breaking and trinification
International Nuclear Information System (INIS)
Carone, Christopher D.; Conroy, Justin M.
2004-01-01
Boundary conditions on an extra dimensional interval can be chosen to break bulk gauge symmetries and to reduce the rank of the gauge group. We consider this mechanism in models with gauge trinification. We determine the boundary conditions necessary to break the trinified gauge group directly down to that of the standard model. Working in an effective theory for the gauge-symmetry-breaking parameters on a boundary, we examine the limit in which the grand-unified theory-breaking-sector is Higgsless and show how one may obtain the low-energy particle content of the minimal supersymmetric standard model. We find that gauge unification is preserved in this scenario, and that the differential gauge coupling running is logarithmic above the scale of compactification. We compare the phenomenology of our model to that of four dimensional 'trinified' theories
Grand unified models including extra Z bosons
International Nuclear Information System (INIS)
Li Tiezhong
1989-01-01
The grand unified theories (GUT) of the simple Lie groups including extra Z bosons are discussed. Under authors's hypothesis there are only SU 5+m SO 6+4n and E 6 groups. The general discussion of SU 5+m is given, then the SU 6 and SU 7 are considered. In SU 6 the 15+6 * +6 * fermion representations are used, which are not same as others in fermion content, Yukawa coupling and broken scales. A conception of clans of particles, which are not families, is suggested. These clans consist of extra Z bosons and the corresponding fermions of the scale. The all of fermions in the clans are down quarks except for the standard model which consists of Z bosons and 15 fermions, therefore, the spectrum of the hadrons which are composed of these down quarks are different from hadrons at present
Centrally managed unified shared virtual address space
Energy Technology Data Exchange (ETDEWEB)
Wilkes, John
2018-02-13
Systems, apparatuses, and methods for managing a unified shared virtual address space. A host may execute system software and manage a plurality of nodes coupled to the host. The host may send work tasks to the nodes, and for each node, the host may externally manage the node's view of the system's virtual address space. Each node may have a central processing unit (CPU) style memory management unit (MMU) with an internal translation lookaside buffer (TLB). In one embodiment, the host may be coupled to a given node via an input/output memory management unit (IOMMU) interface, where the IOMMU frontend interface shares the TLB with the given node's MMU. In another embodiment, the host may control the given node's view of virtual address space via memory-mapped control registers.
Alternative Fuels Data Center: Mesa Unified School District Reaps Economic
and Environmental Benefits with Propane Buses Mesa Unified School District Reaps Economic and School District Reaps Economic and Environmental Benefits with Propane Buses on Facebook Tweet about Alternative Fuels Data Center: Mesa Unified School District Reaps Economic and Environmental Benefits with
Unified SU(4) color models in ten dimensions
International Nuclear Information System (INIS)
Hanlon, B.E.; Joshi, G.C.
1992-01-01
Some aspects of constructing unified models with SU(4) as the color group via a unifying group defined in ten dimensions are examined. Four dimensional theories are recovered using the Coset Space Dimensional Reduction scheme. Candidate models are considered in order to highlight some of the difficulties in constructing realistic four dimensional theories. 30 refs
A Unified Scaling Law in Spiral Galaxies.
Koda; Sofue; Wada
2000-03-01
We investigate the origin of a unified scaling relation in spiral galaxies. Observed spiral galaxies are spread on a plane in the three-dimensional logarithmic space of luminosity L, radius R, and rotation velocity V. The plane is expressed as L~&parl0;VR&parr0;alpha in the I passband, where alpha is a constant. On the plane, observed galaxies are distributed in an elongated region which looks like the shape of a surfboard. The well-known scaling relations L-V (Tully-Fisher [TF] relation), V-R (also the TF relation), and R-L (Freeman's law) can be understood as oblique projections of the surfboard-like plane into two-dimensional spaces. This unified interpretation of the known scaling relations should be a clue to understand the physical origin of all the relations consistently. Furthermore, this interpretation can also explain why previous studies could not find any correlation between TF residuals and radius. In order to clarify the origin of this plane, we simulate formation and evolution of spiral galaxies with the N-body/smoothed particle hydrodynamics method, including cooling, star formation, and stellar feedback. Initial conditions are set to 14 isolated spheres with two free parameters, such as mass and angular momentum. The cold dark matter (h=0.5, Omega0=1) cosmology is considered as a test case. The simulations provide the following two conclusions: (1) The slope of the plane is well reproduced but the zero point is not. This zero-point discrepancy could be solved in a low-density (Omega00.5) cosmology. (2) The surfboard-shaped plane can be explained by the control of galactic mass and angular momentum.
75 FR 62061 - Proposed Flood Elevation Determinations
2010-10-07
... extending approximately 510 feet east along Sandy Drive. * National Geodetic Vertical Datum. Depth in feet above ground. + North American Vertical Datum. [caret] Mean Sea Level, rounded to the nearest 0.1 meter... Club Drain. [[Page 62063
Coral Reef and Hardbottom from Unified Florida Reef Tract Map (NODC Accession 0123059)
National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is a subset of the Unified Map representing Coral reef and Hardbottom areas. Version 1.1 - December 2013. The Unified Florida Reef Tract Map (Unified...
MOONLIGHT: A NEW LUNAR LASER RANGING RETROREFLECTOR AND THE LUNAR GEODETIC PRECESSION
Directory of Open Access Journals (Sweden)
M. Martini
2013-12-01
Full Text Available Since the 1970s Lunar Laser Ranging (LLR to the Apollo Cube Corner Retroreflector (CCR arrays (developed by the University of Maryland, UMD supplied almost all significant tests of General Relativity (Alley et al., 1970; Chang et al., 1971; Bender et al.,1973: possible changes in the gravitational constant, gravitational self-energy, weak equivalence principle, geodetic precession, inverse-square force-law. The LNF group, in fact, has just completed a new measurement of the lunar geodetic precession with Apollo array, with accuracy of 9 × 10−3, comparable to the best measurement to date. LLR has also provided significant information on the composition and origin of the moon. This is the only Apollo experiment still in operation. In the 1970s Apollo LLR arrays contributed a negligible fraction of the ranging error budget. Since the ranging capabilities of ground stations improved by more than two orders of magnitude, now, because of the lunar librations, Apollo CCR arrays dominate the error budget. With the project MoonLIGHT (Moon Laser Instrumentation for General relativity High-accuracy Tests, in 2006 INFN-LNF joined UMD in the development and test of a new-generation LLR payload made by a single, large CCR (100mm diameter unaffected by the effect of librations. With MoonLIGHT CCRs the accuracy of the measurement of the lunar geodetic precession can be improved up to a factor 100 compared to Apollo arrays. From a technological point of view, INFN-LNF built and is operating a new experimental apparatus (Satellite/lunar laser ranging Characterization Facility, SCF and created a new industry-standard test procedure (SCF-Test to characterize and model the detailed thermal behavior and the optical performance of CCRs in accurately laboratory-simulated space conditions, for industrial and scientific applications. Our key experimental innovation is the concurrent measurement and modeling of the optical Far Field Diffraction Pattern (FFDP and the
The potential role of real-time geodetic observations in tsunami early warning
Tinti, Stefano; Armigliato, Alberto
2016-04-01
experimental or testing stage and haven't been implemented yet in any standard TWS operations. Nonetheless, this is seen to be the future and the natural TWS evolving enhancement. In this context, improvement of the real-time estimates of tsunamigenic earthquake focal mechanism is of fundamental importance to trigger the appropriate computational chain. Quick discrimination between strike-slip and thrust-fault earthquakes, and equally relevant, quick assessment of co-seismic on-fault slip distribution, are exemplary cases to which a real-time geodetic monitoring system can contribute significantly. Robust inversion of geodetic data can help to reconstruct the sea floor deformation pattern especially if two conditions are met: the source is not too far from network stations and is well covered azimuthally. These two conditions are sometimes hard to satisfy fully, but in certain regions, like the Mediterranean and the Caribbean sea, this is quite possible due to the limited size of the ocean basins. Close cooperation between the Global Geodetic Observing System (GGOS) community, seismologists, tsunami scientists and TWS operators is highly recommended to obtain significant progresses in the quick determination of the earthquake source, which can trigger a timely estimation of the ensuing tsunami and a more reliable and detailed assessment of the tsunami size at the coast.
Feasibility of Construction of the Continuously Operating Geodetic GPS Network of Sinaloa, Mexico
Vazquez, G. E.; Jacobo, C.
2011-12-01
This research is based on the study and analysis of feasibility for the construction of the geodetic network for GPS continuous operation for Sinaloa, hereafter called (RGOCSIN). A GPS network of continuous operation is defined as that materialized structure physically through permanent monuments where measurements to the systems of Global Positioning (GPS) is performed continuously throughout a region. The GPS measurements in this network are measurements of accuracy according to international standards to define its coordinates, thus constituting the basic structure of geodetic referencing for a country. In this context is that in the near future the RGOCSIN constitutes a system state only accurate and reliable georeferencing in real-time (continuous and permanent operation) and will be used for different purposes; i.e., in addition to being fundamental basis for any lifting topographic or geodetic survey, and other areas such as: (1) Different construction processes (control and monitoring of engineering works); (2) Studies of deformation of the Earth's crust (before and after a seismic event); (3) GPS meteorology (weather forecasting); (4) Demarcation projects (natural and political); (5) Establishment of bases to generate mapping (necessary for the economic and social development of the state); (6) Precision agriculture (optimization of economic resources to the various crops); (7) Geographic information systems (Organization and planning activities associated with the design and construction of public services); (8) Urban growth (possible settlements in the appropriate form and taking care of the environmental aspect), among others. However there are criteria and regulations according to the INEGI (Instituto Nacional de Estadística y Geografía, http://www.inegi.org.mx/) that must be met; even for this stage of feasibility of construction that sees this project as a first phase. The fundamental criterion to be taken into account according to INEGI is a
Installation of a seafloor geodetic network offshore northern Chile (GeoSEA)
Kopp, Heidrun; Lange, Dietrich; Hannemann, Katrin; Petersen, Florian; Contreras-Reyes, Eduardo
2016-04-01
The seafloor stores crucial information on sub-seafloor processes, including stress, elastic strain, and earthquake and tsunami generation. This information may be extracted through the nascent scientific field of seafloor geodesy. The target of the recently installed GeoSEA array (Geodetic Earthquake Observatory on the SEAfloor) is to measure crustal deformation in mm-scale on the marine forearc and outer rise of the South American subduction system around 21°S. This segment of the Nazca-South American plate boundary has last ruptured in an earthquake in 1877 and was identified as a seismic gap prior to the 2014 Iquique/Pisagua earthquake (Mw=8.1). The southern portion of the segment remains unbroken by a recent earthquake. Seafloor geodetic measurements provide a way to monitor crustal deformation at high resolution comparable to the satellite-based GPS technique upon which terrestrial geodesy is largely based. The GeoSEA Network consists of autonomous seafloor transponders installed on 4 m high tripods, which were lowered to the seabed on the deep-sea cable of RV SONNE in December 2015. The transponders within an array intercommunicate via acoustic signals for a period of up to 3.5 years and measure acoustic distance, tilt and pressure. An additional component of the network is GeoSURF, a self-steering autonomous surface vehicle (Wave Glider), which monitors system health and is capable to upload the seafloor data to the sea surface and to transfer it via satellite. We have chosen three areas on the middle and lower slope and the outer rise for the set-up of three sub-arrays. The array in Area 1 on the middle continental slope consists of 8 transponders located in pairs on four topographic ridges, which are surface expressions of faults at depth. Area 2 is located on the outer rise seaward of the trench where 5 stations monitor extension across plate-bending related normal faults. The third area is located at water depth >5000 m on the lower continental slope
Geodetic Measurements and Mechanical Models of Cyclic Deformation at Okmok Volcano, Alaska
Feigl, K.; Masterlark, T.; Lu, Z.; Ohlendorf, S. J.; Thurber, C. H.; Sigmundsson, F.
2009-12-01
The 1997 and 2008 eruptions of Okmok volcano, Alaska, provide a rare opportunity for conducting a rheological experiment to unravel the complex processes associated with magma migration, storage, and eruption in an active volcano. In this experiment, the magma flux during the eruption provides the “impulse” and the subsequent, transient deformation, the “response”. By simulating the impulse, measuring the response, and interpreting the constitutive relations between the two, one can infer the rheology. Okmok is an excellent natural laboratory for such an experiment because a complete cycle of deformation has been monitored using geodetic and seismic means, including: (a) geodetic time series from Interferometric Synthetic Aperture Radar (InSAR) and the Global Positioning System (GPS), (b) earthquake locations; and (c) seismic tomography. We are developing quantitative models using the Finite Element Method (FEM) to simulate the timing and location of the observed seismicity and deformation by accounting for: (a) the geometry and loading of the magma chamber and lava flow, (b) the spatial distribution of material properties; and (c) the constitutive (rheological) relations between stress and strain. Here, we test the hypothesis that the deformation following the 1997 eruption did not reach a steady state before the eruption in 2008. To do so, we iteratively confront the FEM models with the InSAR measurements using the General Inversion of Phase Technique (GIPhT). This approach models the InSAR phase data directly, without unwrapping, as developed, validated, and applied by Feigl and Thurber [Geophys. J. Int., 2009]. By minimizing a cost function that quantifies the misfit between observed and modeled values in terms of “wrapped” phase (with values ranging from -1/2 to +1/2 cycles), GIPhT can estimate parameters in a geophysical model. By avoiding the pitfalls of phase-unwrapping approaches, GIPhT allows the analysis, interpretation and modeling of more
Seismicity and seismic hazard in Sabah, East Malaysia from earthquake and geodetic data
Gilligan, A.; Rawlinson, N.; Tongkul, F.; Stephenson, R.
2017-12-01
While the levels of seismicity are low in most of Malaysia, the state of Sabah in northern Borneo has moderate levels of seismicity. Notable earthquakes in the region include the 1976 M6.2 Lahad Datu earthquake and the 2015 M6 Ranau earthquake. The recent Ranau earthquake resulted in the deaths of 18 people on Mt Kinabalu, an estimated 100 million RM ( US$23 million) damage to buildings, roads, and infrastructure from shaking, and flooding, reduced water quality, and damage to farms from landslides. Over the last 40 years the population of Sabah has increased to over four times what it was in 1976, yet seismic hazard in Sabah remains poorly understood. Using seismic and geodetic data we hope to better quantify the hazards posed by earthquakes in Sabah, and thus help to minimize risk. In order to do this we need to know about the locations of earthquakes, types of earthquakes that occur, and faults that are generating them. We use data from 15 MetMalaysia seismic stations currently operating in Sabah to develop a region-specific velocity model from receiver functions and a pre-existing surface wave model. We use this new velocity model to (re)locate earthquakes that occurred in Sabah from 2005-2016, including a large number of aftershocks from the 2015 Ranau earthquake. We use a probabilistic nonlinear earthquake location program to locate the earthquakes and then refine their relative locations using a double difference method. The recorded waveforms are further used to obtain moment tensor solutions for these earthquakes. Earthquake locations and moment tensor solutions are then compared with the locations of faults throughout Sabah. Faults are identified from high-resolution IFSAR images and subsequent fieldwork, with a particular focus on the Lahad Datau and Ranau areas. Used together, these seismic and geodetic data can help us to develop a new seismic hazard model for Sabah, as well as aiding in the delivery of outreach activities regarding seismic hazard
THE ROLE OF ASTRO-GEODETIC IN PRECISE GUIDANCE OF LONG TUNNELS
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M. Mirghasempour
2015-12-01
Full Text Available One of prime aspects of surveying projects is guidance of paths of a long tunnel from different directions and finally ending all paths in a specific place. This kind of underground surveying, because of particular condition, has some different points in relation to the ground surveying, including Improper geometry in underground transverse, low precise measurement in direction and length due to condition such as refraction, distinct gravity between underground point and corresponding point on the ground (both value and direction of gravity and etc. To solve this problems, astro-geodetic that is part of geodesy science, can help surveying engineers. In this article, the role of astronomy is defined in two subjects: 1- Azimuth determination of directions from entrance and exit nets of tunnel and also calibration of gyro-theodolite to use them in Underground transvers: By astronomical methods, azimuth of directions can be determine with an accuracy of 0.5 arcsecond, whereas, nowadays, no gyroscope can measure the azimuth in this accuracy; For instance, accuracy of the most precise gyroscope (Gyromat 5000 is 1.2 cm over a distance of one kilometre (2.4 arcsecond. Furthermore, the calibration methods that will be mention in this article, have significance effects on underground transverse. 2- Height relation between entrance point and exit point is problematic and time consuming; For example, in a 3 km long tunnel ( in Arak- Khoram Abad freeway, to relate entrance point to exit point, it is necessary to perform levelling about 90 km. Other example of this boring and time consuming levelling is in Kerman tunnel. This tunnel is 36 km length, but to transfer the entrance point height to exit point, 150 km levelling is needed. According to this paper, The solution for this difficulty is application of astro-geodetic and determination of vertical deflection by digital zenith camera system TZK2-D. These two elements make possible to define geoid profile
National Oceanic and Atmospheric Administration, Department of Commerce — This collection contains Sensor Data Records (SDRs), Geodetic Data Records (GDRs), Waveform Data Records (WDRs), and Crossover Difference data Records (XDRs) from...
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Slavomír Labant
2011-12-01
Full Text Available This article addresses the adjustment of a 3D geodetic network in the Dargovských Hrdinov suburbs using Global Navigation SatelliteSystems (GNSS for the purposes of deformation analysis. The advantage of using the GNSS compared to other terrestrial technology is thatit is not influenced by unpredictability in the ground level atmosphere and individual visibilities between points in the observed network arenot necessary. This article also includes the planning of GNSS observations using Planning Open Source software from Trimble as well assubsequent observations at individual network points. The geodetic network is processing on the basis of the Gauss-Markov model usingthe least square method and robust adjustment. From robust methods, Huber’s Robust M-estimation and Hampel’s Robust M-estimationwere used. Individual adjustments were tested and subsequently the results of analysis were graphically visualised using absolute confidenceellipsoids.
Dapo, A.; Pribicevic, B.; Herak, M.; Prelogovic, E.
2012-04-01
Since the last great earthquake in 1880 which shook the Zagreb area with IX° MCS, tectonic movements and models of numerous Zagreb faults have been the focal point of Croatian geologists, seismologists and in the last 15 years also geodetic scientists, who all have been working in the scope of their scientific branches on bringing the light to the tectonic mechanisms in the wider Zagreb area. Since it is tectonically very active area and being the Capitol city of the Croatia with very high population density it is of utmost importance to understand those mechanisms and to according to them find the best possible measures for protecting people and valuables. Best results are certainly going to be achieved through the interdisciplinary approach. That is why this paper presents first interdisciplinary results from geodetic, geologic and seismic researches and their contribution to the collective knowledge about tectonic movements in the wider area of the City of Zagreb.
Segall, P; Harris, R
1986-09-26
A network of geodetic lines spanning the San Andreas fault near the rupture zone of the 1966 Parkfield, California, earthquake (magnitude M = 6) has been repeatedly surveyed since 1959. In the study reported here the average rates of line-length change since 1966 were inverted to determine the distribution of interseismic slip rate on the fault. These results indicate that the Parkfield rupture surface has not slipped significantly since 1966. Comparison of the geodetically determined seismic moment of the 1966 earthquake with the interseismic slip-deficit rate suggests that the strain released by the latest shock will most likely be restored between 1984 and 1989, although this may not occur until 1995. These results lend independent support to the earlier forecast of an M = 6 earthquake near Parkfield within 5 years of 1988.
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Kadaj Roman
2016-12-01
Full Text Available The adjustment problem of the so-called combined (hybrid, integrated network created with GNSS vectors and terrestrial observations has been the subject of many theoretical and applied works. The network adjustment in various mathematical spaces was considered: in the Cartesian geocentric system on a reference ellipsoid and on a mapping plane. For practical reasons, it often takes a geodetic coordinate system associated with the reference ellipsoid. In this case, the Cartesian GNSS vectors are converted, for example, into geodesic parameters (azimuth and length on the ellipsoid, but the simple form of converted pseudo-observations are the direct differences of the geodetic coordinates. Unfortunately, such an approach may be essentially distorted by a systematic error resulting from the position error of the GNSS vector, before its projection on the ellipsoid surface. In this paper, an analysis of the impact of this error on the determined measures of geometric ellipsoid elements, including the differences of geodetic coordinates or geodesic parameters is presented. Assuming that the adjustment of a combined network on the ellipsoid shows that the optimal functional approach in relation to the satellite observation, is to create the observational equations directly for the original GNSS Cartesian vector components, writing them directly as a function of the geodetic coordinates (in numerical applications, we use the linearized forms of observational equations with explicitly specified coefficients. While retaining the original character of the Cartesian vector, one avoids any systematic errors that may occur in the conversion of the original GNSS vectors to ellipsoid elements, for example the vector of the geodesic parameters. The problem is theoretically developed and numerically tested. An example of the adjustment of a subnet loaded from the database of reference stations of the ASG-EUPOS system was considered for the preferred functional
Riccardi, U.; Arnoso, J.; Benavent, M.; Vélez, E.; Tammaro, U.; Montesinos, F. G.
2018-05-01
We report on a detailed geodetic continuous monitoring in Timanfaya volcanic area (TVA), where the most intense geothermal anomalies of Lanzarote Island are located. We analyze about three years of GNSS data collected on a small network of five permanent stations, one of which at TVA, deployed on the island, and nearly 20 years of tiltmeter and strainmeter records acquired at Los Camelleros site settled in the facilities of the Geodynamics Laboratory of Lanzarote within TVA. This study is intended to contribute to understanding the active tectonics on Lanzarote Island and its origin, mainly in TVA. After characterizing and filtering out the seasonal periodicities related to "non-tectonic" sources from the geodetic records, a tentative ground deformation field is reconstructed through the analysis of both tilt, strain records and the time evolution of the baselines ranging the GNSS stations. The joint interpretation of the collected geodetic data show that the area of the strongest geothermal anomaly in TVA is currently undergoing a SE trending relative displacement at a rate of about 3 mm/year. This area even experiences a significant subsidence with a maximum rate of about 6 mm/year. Moreover, we examine the possible relation between the observed deformations and atmospheric effects by modelling the response functions of temperature and rain recorded in the laboratory. Finally, from the retrieval of the deformation patterns and the joint analysis of geodetic and environmental observations, we propose a qualitative model of the interplaying role between the hydrological systems and the geothermal anomalies. Namely, we explain the detected time correlation between rainfall and ground deformation because of the enhancement of the thermal transfer from the underground heat source driven by the infiltration of meteoric water.
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Mircea Ortelecan
2016-11-01
Full Text Available The paper analyzes the possibility to establish the coefficient of scale towards the total station scale triangulation network in the conduct of geodetic and topographic observations in the points with known coordinates (old points or points whose coordinates we want to determine (new points. The purpose of the study is undertaken to simplify computing operations to reduce distances measured from the topographic surface to the Stereo 70 projection plan.
Iles, E. J.; McCallum, L.; Lovell, J. E. J.; McCallum, J. N.
2018-02-01
As we move into the next era of geodetic VLBI, the scheduling process is one focus for improvement in terms of increased flexibility and the ability to react with changing conditions. A range of simulations were conducted to ascertain the impact of scheduling on geodetic results such as Earth Orientation Parameters (EOPs) and station coordinates. The potential capabilities of new automated scheduling modes were also simulated, using the so-called 'dynamic scheduling' technique. The primary aim was to improve efficiency for both cost and time without losing geodetic precision, particularly to maximise the uses of the Australian AuScope VLBI array. We show that short breaks in observation will not significantly degrade the results of a typical 24 h experiment, whereas simply shortening observing time degrades precision exponentially. We also confirm the new automated, dynamic scheduling mode is capable of producing the same standard of result as a traditional schedule, with close to real-time flexibility. Further, it is possible to use the dynamic scheduler to augment the 3 station Australian AuScope array and thereby attain EOPs of the current global precision with only intermittent contribution from 2 additional stations. We thus confirm automated, dynamic scheduling bears great potential for flexibility and automation in line with aims for future continuous VLBI operations.
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Luca Vittuari
2016-04-01
Full Text Available This paper compares three different methods capable of estimating the deflection of the vertical (DoV: one is based on the joint use of high precision spirit leveling and Global Navigation Satellite Systems (GNSS, a second uses astro-geodetic measurements and the third gravimetric geoid models. The working data sets refer to the geodetic International Terrestrial Reference Frame (ITRF co-location sites of Medicina (Northern, Italy and Noto (Sicily, these latter being excellent test beds for our investigations. The measurements were planned and realized to estimate the DoV with a level of precision comparable to the angular accuracy achievable in high precision network measured by modern high-end total stations. The three methods are in excellent agreement, with an operational supremacy of the astro-geodetic method, being faster and more precise than the others. The method that combines leveling and GNSS has slightly larger standard deviations; although well within the 1 arcsec level, which was assumed as threshold. Finally, the geoid model based method, whose 2.5 arcsec standard deviations exceed this threshold, is also statistically consistent with the others and should be used to determine the DoV components where local ad hoc measurements are lacking.
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Ryszard MIELIMĄKA
2014-10-01
Full Text Available The article presents the problem of the usage of post‐processing services of the ASG‐EUPOS system on the example of GNSS network established for geodetic service of building of the inclined drift, to make coal deposit accessible, and also building associated objects. For the purpose of geodetic service of construction realization network was established outside the planned objects. The network consists of six new ground points and four control points belonging to ASG‐EUPOS network. Simultaneous, static measurements of the network were performed in three‐hour observation session, using multi‐frequency and multi‐system satellite receivers – Trimble R8. The paper presents three variants of post‐processing of the observation results. Calculations were performed using POZGEO‐D service and geodetic software package GEONET. The results of the calculation process revealed, that homogeneous vector networks should be adjusted on the ellipsoid or in the geocentric system. Model of adjustment of the vector network on the plane adopted in the GEONET software package should not be applied for elaboration of this type of network (long reference vectors more than 50km.
The astro-geodetic use of CCD for gravity field refinement
Gerstbach, G.
1996-07-01
The paper starts with a review of geoid projects, where vertical deflections are more effective than gravimetry. In alpine regions the economy of astrogeoids is at least 10 times higher, but many countries do not make use of this fact - presumably because the measurements are not fully automated up to now. Based upon the experiences of astrometry of high satellites and own tests the author analyses the use of CCD for astro-geodetic measurements. Automation and speeding up will be possible in a few years, the latter depending on the observation scheme. Sensor characteristics, cooling and reading out of the devices should be harmonized. Using line sensors in small prism astrolabes, the CCD accuracy will reach the visual one (±0.2″) within 5-10 years. Astrogeoids can be combined ideally with geological data, because vertical variation of rock densities does not cause systematic effects (contrary to gravimetry). So a geoid of ±5 cm accuracy (achieved in Austria and other alpine countries by 5-10 points per 1000 km 2) can be improved to ±2 cm without additional observations and border effects.
Geodetic proof of vertical recent movements at the seism generating zone of Acambay, Mexico
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Luis Miguel Espinosa-Rodríguez
2016-12-01
Full Text Available The central territorial belt oriented west-east and located along the parallel 19 in the Mexican Republic, is composed of a complex system of faults, that respond to the consequent morphology of a tension arched system, which has been erected to the Volcanic Transmexican or Transversal Belt. This region evidences the dynamics and evolution of a graben and horst tectonic system, as well as volcanic manifestations characterized by stratovolcanoes, monogenetic fields and fisural flows, among others. In particular, in the center of the Mexican regional complex, the fault system which delimits the region of Acambay in the state of Mexico, had showed evidences of seismogenerating activity during a century until the present time. According to the above and based on the geomorphological analysis and the geodetic measurements, the dynamic presented by these morphostructures in a multitemporal comparative study (1998/2003 o 2011 is showed. The rates of vertical tectonic movements reflect recent rise values ranging from + 7,3 to 12,8 mm/year in the northern horst of Santa María Tixmadejé, while in the central graben of Acambay are very weak, of the order of + 0,4 to + 0,5 mm/year.
Geodetic Finite-Fault-based Earthquake Early Warning Performance for Great Earthquakes Worldwide
Ruhl, C. J.; Melgar, D.; Grapenthin, R.; Allen, R. M.
2017-12-01
GNSS-based earthquake early warning (EEW) algorithms estimate fault-finiteness and unsaturated moment magnitude for the largest, most damaging earthquakes. Because large events are infrequent, algorithms are not regularly exercised and insufficiently tested on few available datasets. The Geodetic Alarm System (G-larmS) is a GNSS-based finite-fault algorithm developed as part of the ShakeAlert EEW system in the western US. Performance evaluations using synthetic earthquakes offshore Cascadia showed that G-larmS satisfactorily recovers magnitude and fault length, providing useful alerts 30-40 s after origin time and timely warnings of ground motion for onshore urban areas. An end-to-end test of the ShakeAlert system demonstrated the need for GNSS data to accurately estimate ground motions in real-time. We replay real data from several subduction-zone earthquakes worldwide to demonstrate the value of GNSS-based EEW for the largest, most damaging events. We compare predicted ground acceleration (PGA) from first-alert-solutions with those recorded in major urban areas. In addition, where applicable, we compare observed tsunami heights to those predicted from the G-larmS solutions. We show that finite-fault inversion based on GNSS-data is essential to achieving the goals of EEW.
Space geodetic observations of repeating slow slip events beneath the Bonin Islands
Arisa, Deasy; Heki, Kosuke
2017-09-01
The Pacific Plate subducts beneath the Philippine Sea Plate along the Izu-Bonin Trench. We investigated crustal movements at the Bonin Islands, using Global Navigation Satellite System and geodetic Very Long Baseline Interferometry data to reveal how the two plates converge in this subduction zone. These islands are located ∼100 km from the trench, just at the middle between the volcanic arc and the trench, making these islands suitable for detecting signatures of episodic deformation such as slow slip events (SSEs). During 2007-2016, we found five SSEs repeating quasi-periodically with similar displacement patterns. In estimating their fault parameters, we assumed that the fault lies on the prescribed plate boundary, and optimized the size, shape and position of the fault and dislocation vectors. Average fault slip was ∼5 cm, and the average moment magnitude was ∼6.9. We also found one SSE occurred in 2008 updip of the repeating SSE in response to an M6 class interplate earthquake. In spite of the frequent occurrence of SSEs, there is no evidence for long-term strain accumulation in the Bonin Islands that may lead to future megathrust earthquakes. Plate convergence in Mariana-type subduction zones may occur, to a large extent, episodically as repeating SSEs.
Application of median-equation approach for outlier detection in geodetic networks
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Serif Hekimoglu
Full Text Available In geodetic measurements some outliers may occur sometimes in data sets, depending on different reasons. There are two main approaches to detect outliers as Tests for outliers (Baarda's and Pope's Tests and robust methods (Danish method, Huber method etc.. These methods use the Least Squares Estimation (LSE. The outliers affect the LSE results, especially it smears the effects of the outliers on the good observations and sometimes wrong results may be obtained. To avoid these effects, a method that does not use LSE should be preferred. The median is a high breakdown point estimator and if it is applied for the outlier detection, reliable results can be obtained. In this study, a robust method which uses median with or as a treshould value on median residuals that are obtained from median equations is proposed. If the a priori variance of the observations is known, the reliability of the new approch is greater than the one in the case where the a priori variance is unknown.
Applications of Voronoi and Delaunay Diagrams in the solution of the geodetic boundary value problem
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C. A. B. Quintero
Full Text Available Voronoi and Delaunay structures are presented as discretization tools to be used in numerical surface integration aiming the computation of geodetic problems solutions, when under the integral there is a non-analytical function (e. g., gravity anomaly and height. In the Voronoi approach, the target area is partitioned into polygons which contain the observed point and no interpolation is necessary, only the original data is used. In the Delaunay approach, the observed points are vertices of triangular cells and the value for a cell is interpolated for its barycenter. If the amount and distribution of the observed points are adequate, gridding operation is not required and the numerical surface integration is carried out by point-wise. Even when the amount and distribution of the observed points are not enough, the structures of Voronoi and Delaunay can combine grid with observed points in order to preserve the integrity of the original information. Both schemes are applied to the computation of the Stokes' integral, the terrain correction, the indirect effect and the gradient of the gravity anomaly, in the State of Rio de Janeiro, Brazil area.
Lehmann, Rüdiger; Lösler, Michael
2017-12-01
Geodetic deformation analysis can be interpreted as a model selection problem. The null model indicates that no deformation has occurred. It is opposed to a number of alternative models, which stipulate different deformation patterns. A common way to select the right model is the usage of a statistical hypothesis test. However, since we have to test a series of deformation patterns, this must be a multiple test. As an alternative solution for the test problem, we propose the p-value approach. Another approach arises from information theory. Here, the Akaike information criterion (AIC) or some alternative is used to select an appropriate model for a given set of observations. Both approaches are discussed and applied to two test scenarios: A synthetic levelling network and the Delft test data set. It is demonstrated that they work but behave differently, sometimes even producing different results. Hypothesis tests are well-established in geodesy, but may suffer from an unfavourable choice of the decision error rates. The multiple test also suffers from statistical dependencies between the test statistics, which are neglected. Both problems are overcome by applying information criterions like AIC.
The Earth isn't flat: The (large) influence of topography on geodetic fault slip imaging.
Thompson, T. B.; Meade, B. J.
2017-12-01
While earthquakes both occur near and generate steep topography, most geodetic slip inversions assume that the Earth's surface is flat. We have developed a new boundary element tool, Tectosaur, with the capability to study fault and earthquake problems including complex fault system geometries, topography, material property contrasts, and millions of elements. Using Tectosaur, we study the model error induced by neglecting topography in both idealized synthetic fault models and for the cases of the MW=7.3 Landers and MW=8.0 Wenchuan earthquakes. Near the steepest topography, we find the use of flat Earth dislocation models may induce errors of more than 100% in the inferred slip magnitude and rake. In particular, neglecting topographic effects leads to an inferred shallow slip deficit. Thus, we propose that the shallow slip deficit observed in several earthquakes may be an artefact resulting from the systematic use of elastic dislocation models assuming a flat Earth. Finally, using this study as an example, we emphasize the dangerous potential for forward model errors to be amplified by an order of magnitude in inverse problems.
Farolfi, Gregorio; Del Ventisette, Chiara
2016-04-01
A new horizontal crustal velocity field of Alpine Mediterranean area was determined by continuous long time series (6.5 years) of 113 Global Navigation Satellite System (GNSS) permanent stations. The processing was performed using state-of-the-art absolute antenna phase center correction model and recomputed precise IGS orbits available since April 2014. Moreover, a new more accurate tropospheric mapping function for geodetic applications was adopted. Results provide a new detailed map of the kinematics throughout the entire study area. This area is characterized by a complex tectonic setting driven by the interaction of Eurasian and African plates. The eastern Alps, Corsica, Sardinia and the Tyrrhenian Sea (which is covered only by interpolation data) show small velocity residuals with respect to the Eurasian plate. The whole Apennines axis discriminates two different velocity patterns, the Adriatic and the Tyrrhenian area. The area around Messina Strait, which separates peninsular Italy and Sicily, represents a poorly understood region. Results identify an important boundary zone between two different domains, Calabria and Sicily, which are characterized by different crustal motions. The northeastern part of Sicily and Calabria move like Adriatic area, whilst the rest of Sicily, Malta and Lampedusa are dominated by African motion.
Engel, P.; Schweimler, B.
2016-04-01
The deformation monitoring of structures and buildings is an important task field of modern engineering surveying, ensuring the standing and reliability of supervised objects over a long period. Several commercial hardware and software solutions for the realization of such monitoring measurements are available on the market. In addition to them, a research team at the Neubrandenburg University of Applied Sciences (NUAS) is actively developing a software package for monitoring purposes in geodesy and geotechnics, which is distributed under an open source licence and free of charge. The task of managing an open source project is well-known in computer science, but it is fairly new in a geodetic context. This paper contributes to that issue by detailing applications, frameworks, and interfaces for the design and implementation of open hardware and software solutions for sensor control, sensor networks, and data management in automatic deformation monitoring. It will be discussed how the development effort of networked applications can be reduced by using free programming tools, cloud computing technologies, and rapid prototyping methods.
Geodetically resolved slip distribution of the 27 August 2012 Mw=7.3 El Salvador earthquake
Geirsson, H.; La Femina, P. C.; DeMets, C.; Hernandez, D. A.; Mattioli, G. S.; Rogers, R.; Rodriguez, M.
2013-12-01
On 27 August 2012 a Mw=7.3 earthquake occurred offshore of Central America causing a small tsunami in El Salvador and Nicaragua but little damage otherwise. This is the largest magnitude earthquake in this area since 2001. We use co-seismic displacements estimated from episodic and continuous GPS station time series to model the magnitude and spatial variability of slip for this event. The estimated surface displacements are small (earthquake. We use TDEFNODE to model the displacements using two different modeling approaches. In the first model, we solve for homogeneous slip on free rectangular fault(s), and in the second model we solve for distributed slip on the main thrust, realized using different slab models. The results indicate that we can match the seismic moment release, with models indicating rupture of a large area, with a low magnitude of slip. The slip is at shallow-to-intermediate depths on the main thrust off the coast of El Salvador. Additionally, we observe a deeper region of slip to the east, that reaches towards the Gulf of Fonseca between El Salvador and Nicaragua. The observed tsunami additionally indicates near-trench rupture off the coast of El Salvador. The duration of the rupturing is estimated from seismic data to be 70 s, which indicates a slow rupture process. Since the geodetic moment we obtain agrees with the seismic moment, this indicates that the earthquake was not associated with aseismic slip.
Pragmatic Information as a Unifying Biological Concept
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Reza Maleeh
2014-09-01
Full Text Available This paper aims to introduce a developed reading of Roederer’s interpretation of pragmatic information as a good candidate for a Unifying Information Concept required for an as-yet-unavailable Science of Information. According to pragmatic information, information and information processing are exclusive attributes of biological systems related to the very definition of life. I will apply the notion to give new accounts in the following areas: (1 quantum interpretation: based on a modified version of David Bohm’s interpretation of quantum mechanics, I propose an ontological, information-based interpretation of quantum mechanics which, unlike Roederer’s interpretation, satisfies all conditions of pragmatic information; (2 artificial intelligence: the notion successfully distinguishes natural living systems from artifacts and natural non-living systems, providing a context to pose an information-based argument against the thesis of Strong Artificial Intelligence; (3 phenomenal consciousness: I will use pragmatic information to modify and update Chalmers’s Double-aspect Theory of Information to be explanatorily more powerful regarding the physical aspect of his theory; (4 causation: based on pragmatic information, I pose a new account of causation which differentiates causation in biology from causation in natural abiotic world.
Unified creep-plasticity model for halite
International Nuclear Information System (INIS)
Krieg, R.D.
1980-11-01
There are two national energy programs which are considering caverns in geological salt (NaCl) as a storage repository. One is the disposal of nuclear wastes and the other is the storage of oil. Both short-time and long-time structural deformations and stresses must be predictable for these applications. At 300K, the nominal initial temperature for both applications, the salt is at 0.28 of the melting temperature and exhibits a significant time dependent behavior. A constitutive model has been developed which describes the behavior observed in an extensive set of triaxial creep tests. Analysis of these tests showed that a single deformation mechanism seems to be operative over the stress and temperature range of interest so that the secondary creep data can be represented by a power of the stress over the entire test range. This simple behavior allowed a new unified creep-plasticity model to be applied with some confidence. The resulting model recognizes no inherent difference between plastic and creep strains yet models the total inelastic strain reasonably well including primary and secondary creep and reverse loadings. A multiaxial formulation is applied with a back stress. A Bauschinger effect is exhibited as a consequence and is present regardless of the time scale over which the loading is applied. The model would be interpreted as kinematic hardening in the sense of classical plasticity. Comparisons are made between test data and model behavior
Randomized central limit theorems: A unified theory.
Eliazar, Iddo; Klafter, Joseph
2010-08-01
The central limit theorems (CLTs) characterize the macroscopic statistical behavior of large ensembles of independent and identically distributed random variables. The CLTs assert that the universal probability laws governing ensembles' aggregate statistics are either Gaussian or Lévy, and that the universal probability laws governing ensembles' extreme statistics are Fréchet, Weibull, or Gumbel. The scaling schemes underlying the CLTs are deterministic-scaling all ensemble components by a common deterministic scale. However, there are "random environment" settings in which the underlying scaling schemes are stochastic-scaling the ensemble components by different random scales. Examples of such settings include Holtsmark's law for gravitational fields and the Stretched Exponential law for relaxation times. In this paper we establish a unified theory of randomized central limit theorems (RCLTs)-in which the deterministic CLT scaling schemes are replaced with stochastic scaling schemes-and present "randomized counterparts" to the classic CLTs. The RCLT scaling schemes are shown to be governed by Poisson processes with power-law statistics, and the RCLTs are shown to universally yield the Lévy, Fréchet, and Weibull probability laws.
Argumentation and Inference: A Unified Approach
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Christophe Fouqueré
2013-12-01
Full Text Available We propose in this paper to use Ludics as a unified framework for the analysis of dialogue and the reasoning system. Not only is Ludics a logical theory, but it may also be built by means of concepts of game theory. We first present the main concepts of Ludics. A design is an abstraction and a generalization of the concept of proof. Interaction between designs is equivalent to cut elimination or modus ponens in logical theories. It appears to be a natural means for representing dialogues and also for reasoning. A design is a set of sequences of alternate actions, similar to a move in game theory. We apply Ludics to argumentative dialogues. We discuss how to model the speech acts of argumentative dialogues in terms of dialogue acts. A dialogue act is given by a Ludics action together with the expression that reveals the action in a turn of speech. We show also how arguments may be stored in a commitment state used for reasoning. Finally we revisit an example of juridical dialogue that has been analyzed by Prakken in a different framework.
Unifying Theories of Psychedelic Drug Effects
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Link R. Swanson
2018-03-01
Full Text Available How do psychedelic drugs produce their characteristic range of acute effects in perception, emotion, cognition, and sense of self? How do these effects relate to the clinical efficacy of psychedelic-assisted therapies? Efforts to understand psychedelic phenomena date back more than a century in Western science. In this article I review theories of psychedelic drug effects and highlight key concepts which have endured over the last 125 years of psychedelic science. First, I describe the subjective phenomenology of acute psychedelic effects using the best available data. Next, I review late 19th-century and early 20th-century theories—model psychoses theory, filtration theory, and psychoanalytic theory—and highlight their shared features. I then briefly review recent findings on the neuropharmacology and neurophysiology of psychedelic drugs in humans. Finally, I describe recent theories of psychedelic drug effects which leverage 21st-century cognitive neuroscience frameworks—entropic brain theory, integrated information theory, and predictive processing—and point out key shared features that link back to earlier theories. I identify an abstract principle which cuts across many theories past and present: psychedelic drugs perturb universal brain processes that normally serve to constrain neural systems central to perception, emotion, cognition, and sense of self. I conclude that making an explicit effort to investigate the principles and mechanisms of psychedelic drug effects is a uniquely powerful way to iteratively develop and test unifying theories of brain function.
Texture Repairing by Unified Low Rank Optimization
Institute of Scientific and Technical Information of China (English)
Xiao Liang; Xiang Ren; Zhengdong Zhang; Yi Ma
2016-01-01
In this paper, we show how to harness both low-rank and sparse structures in regular or near-regular textures for image completion. Our method is based on a unified formulation for both random and contiguous corruption. In addition to the low rank property of texture, the algorithm also uses the sparse assumption of the natural image: because the natural image is piecewise smooth, it is sparse in certain transformed domain (such as Fourier or wavelet transform). We combine low-rank and sparsity properties of the texture image together in the proposed algorithm. Our algorithm based on convex optimization can automatically and correctly repair the global structure of a corrupted texture, even without precise information about the regions to be completed. This algorithm integrates texture rectification and repairing into one optimization problem. Through extensive simulations, we show our method can complete and repair textures corrupted by errors with both random and contiguous supports better than existing low-rank matrix recovery methods. Our method demonstrates significant advantage over local patch based texture synthesis techniques in dealing with large corruption, non-uniform texture, and large perspective deformation.
Constraints on grand unified superstring theories
International Nuclear Information System (INIS)
Ellis, J.; Lopez, J.L.; Nanopoulos, D.V.; Houston Advanced Research Center
1990-01-01
We evaluate some constraints on the construction of grand unified superstring theories (GUSTs) using higher level Kac-Moody algebras on the world-sheet. In the most general formulation of the heterotic string in four dimensions, an analysis of the basic GUST model-building constraints, including a realistic hidden gauge group, reveals that there are no E 6 models and any SO(10) models can only exist at level-5. Also, any such SU(5) models can exist only for levels 4≤k≤19. These SO(10) and SU(5) models risk having many large, massless, phenomenologically troublesome representations. We also show that with a suitable hidden sector gauge group, it is possible to avoid free light fractionally charged particles, which are endemic to string derived models. We list all such groups and their representations for the flipped SU(5)xU(1) model. We conclude that a sufficiently binding hidden sector gauge group becomes a basic model-building constraint. (orig.)
A Unified Model for Tidal Disruption Events
Dai, Lixin; McKinney, Jonathan C.; Roth, Nathaniel; Ramirez-Ruiz, Enrico; Miller, M. Coleman
2018-06-01
In the past few years wide-field optical and UV transient surveys and X-ray telescopes have allowed us to identify a few dozen candidate tidal disruption events (TDEs). While in theory the physical processes in TDEs are ubiquitous, a few distinct classes of TDEs have been observed. Some TDEs radiate mainly in NUV/optical, while others produce prominent X-rays. Moreover, relativistic jets have been observed in only a handful of TDEs. This diversity might be related to the details of the super-Eddington accretion and emission physics relevant to TDE disks. In this Letter, we utilize novel three-dimensional general relativistic radiation magnetohydrodynamics simulations to study the super-Eddington compact disk phase expected in TDEs. Consistent with previous studies, geometrically thick disks, wide-angle optically thick fast outflows, and relativistic jets are produced. The outflow density and velocity depend sensitively on the inclination angle, and hence so does the reprocessing of emission produced from the inner disk. We then use Monte Carlo radiative transfer to calculate the reprocessed spectra and find that that the observed ratio of optical to X-ray fluxes increases with increasing inclination angle. This naturally leads to a unified model for different classes of TDEs in which the spectral properties of the TDE depend mainly on the viewing angle of the observer with respect to the orientation of the disk.
A unified grand tour of theoretical physics
Griffiths, J
2002-01-01
Anyone offering a grand tour is faced with several options. Should they concentrate on what may be considered to be essential features, or should they attempt to present a brief glimpse of almost everything? The present offering is a compromise between these two extremes. The area considered - theoretical physics - is now such a vast subject that some kind of compromise is essential. Indeed, the field is now so wide that few could even attempt to review it in a single-authored work. My task here is to assess how well this book has succeeded in its main aim of providing a unified (though introductory) tour of this subject. Constrained within a single volume, this is clearly not an updated Landau-Lifschitz. It cannot be expected to take any particular topic to the level of recent research. Nevertheless, it does seem to cover the broad range of essential topics which now constitute the subject. It starts (most appropriately in my opinion) with geometry. It then covers classical physics, general relativity and qu...
Unifying Theories of Psychedelic Drug Effects
Swanson, Link R.
2018-01-01
How do psychedelic drugs produce their characteristic range of acute effects in perception, emotion, cognition, and sense of self? How do these effects relate to the clinical efficacy of psychedelic-assisted therapies? Efforts to understand psychedelic phenomena date back more than a century in Western science. In this article I review theories of psychedelic drug effects and highlight key concepts which have endured over the last 125 years of psychedelic science. First, I describe the subjective phenomenology of acute psychedelic effects using the best available data. Next, I review late 19th-century and early 20th-century theories—model psychoses theory, filtration theory, and psychoanalytic theory—and highlight their shared features. I then briefly review recent findings on the neuropharmacology and neurophysiology of psychedelic drugs in humans. Finally, I describe recent theories of psychedelic drug effects which leverage 21st-century cognitive neuroscience frameworks—entropic brain theory, integrated information theory, and predictive processing—and point out key shared features that link back to earlier theories. I identify an abstract principle which cuts across many theories past and present: psychedelic drugs perturb universal brain processes that normally serve to constrain neural systems central to perception, emotion, cognition, and sense of self. I conclude that making an explicit effort to investigate the principles and mechanisms of psychedelic drug effects is a uniquely powerful way to iteratively develop and test unifying theories of brain function. PMID:29568270
75 FR 29219 - Proposed Flood Elevation Determinations
2010-05-25
... County. approximately 268 feet upstream of Robbin Lane. * National Geodetic Vertical Datum. + North... Judge, 516 Fairway Drive, Brandenburg, KY 40108. Scott County, Kentucky, and Incorporated Areas Dry Run...
Ontology-based Metadata Portal for Unified Semantics
National Aeronautics and Space Administration — The Ontology-based Metadata Portal for Unified Semantics (OlyMPUS) will extend the prototype Ontology-Driven Interactive Search Environment for Earth Sciences...
The Relationship Between Unified Communications and Big Data ...
African Journals Online (AJOL)
pc
2018-03-05
Mar 5, 2018 ... Keywords- Big data, Unified Communications, Big Data. Analytics ... sensors through a phenomenon referred to as Internet of. Things (IoT). ... warehouse which utilized when dealing with large quantities of unstructured data.
Constructing 5d orbifold grand unified theories from heterotic strings
International Nuclear Information System (INIS)
Kobayashi, Tatsuo; Raby, Stuart; Zhang Renjie
2004-01-01
A three-generation Pati-Salam model is constructed by compactifying the heterotic string on a particular T 6 /Z 6 Abelian symmetric orbifold with two discrete Wilson lines. The compactified space is taken to be the Lie algebra lattice G 2 -bar SU(3)-bar SO(4). When one dimension of the SO(4) lattice is large compared to the string scale, this model reproduces many features of a 5d SO(10) grand unified theory compactified on an S 1 /Z 2 orbifold. (Of course, with two large extra dimensions we can obtain a 6d SO(10) grand unified theory.) We identify the orbifold parities and other ingredients of the orbifold grand unified theories in the string model. Our construction provides a UV completion of orbifold grand unified theories, and gives new insights into both field theoretical and string theoretical constructions
On unified-entropy characterization of quantum channels
International Nuclear Information System (INIS)
Rastegin, A E
2012-01-01
We consider properties of quantum channels with the use of unified entropies. Extremal unravelings of quantum channel with respect to these entropies are examined. The concept of map entropy is extended in terms of the unified entropies. The map (q, s)-entropy is naturally defined as the unified (q, s)-entropy of a rescaled dynamical matrix of given quantum channel. Inequalities of Fannes type are obtained for introduced entropies in terms of both the trace and Frobenius norms of difference between corresponding dynamical matrices. Additivity properties of introduced map entropies are discussed. The known inequality of Lindblad with the entropy exchange is generalized to many of the unified entropies. For the tensor product of a pair of quantum channels, we derive a two-sided estimate on the output entropy of a maximally entangled input state. (paper)
Generalized projective synchronization of a unified chaotic system
International Nuclear Information System (INIS)
Yan Jianping; Li Changpin
2005-01-01
In the present paper, a simple but efficient control technique of the generalized projective synchronization is applied to a unified chaotic system. Numerical simulations show that this method works very well, which can also be applied to other chaotic systems
A Unified Mathematical Definition of Classical Information Retrieval.
Dominich, Sandor
2000-01-01
Presents a unified mathematical definition for the classical models of information retrieval and identifies a mathematical structure behind relevance feedback. Highlights include vector information retrieval; probabilistic information retrieval; and similarity information retrieval. (Contains 118 references.) (Author/LRW)
Unified composite model of all fundamental particles and forces
International Nuclear Information System (INIS)
Terazawa, H.
2000-01-01
The unified supersymmetric composite model of all fundamental particles (and forces) including not only the fundamental fermions (quarks and leptons) but also the fundamental bosons (gauge bosons and Higgs scalars) is reviewed in detail
Unified Nonlinear Flight Dynamics and Aeroelastic Simulator Tool, Phase I
National Aeronautics and Space Administration — ZONA Technology, Inc. (ZONA) proposes a R&D effort to develop a Unified Nonlinear Flight Dynamics and Aeroelastic Simulator (UNFDAS) Tool that will combine...
Supergravity and the quest for a unified theory
International Nuclear Information System (INIS)
Ferrara, S.
1995-01-01
The foundation of supergravity and research in its subsequent developments is described. Special emphasis is placed on the impact of supergravity on the search for a unified theory of fundamental interactions. (author)
Top-down approach to unified supergravity models
International Nuclear Information System (INIS)
Hempfling, R.
1994-03-01
We introduce a new approach for studying unified supergravity models. In this approach all the parameters of the grand unified theory (GUT) are fixed by imposing the corresponding number of low energy observables. This determines the remaining particle spectrum whose dependence on the low energy observables can now be investigated. We also include some SUSY threshold corrections that have previously been neglected. In particular the SUSY threshold corrections to the fermion masses can have a significant impact on the Yukawa coupling unification. (orig.)
Restrictions on SU(5) as a grand unified theory
International Nuclear Information System (INIS)
Shellard, R.C.
1984-01-01
Some restrictions imposed upon Grand Unified Theories by dynamical symetry breakdown are examined. They are shown that, in particular, theories SU(5) as symmetry group, with 3 or more fermion families undergo dynamical symmetry breakdown, and some of the fermions will acquire mass at the Grand Unified scale. On the other hand, the SO(10) group, with 3 families is free from this problem. (Author) [pt
Lattice mechanics of ionic crystals - unified study
International Nuclear Information System (INIS)
Sengupta, S.; Roy, D.; Basu, A.N.
1979-01-01
The up-to-date situation in the understanding of the mechanical properties of ionic solids is reviewed. These properties are determined by the Born-Oppenheimer (B-O) potential energy function. For ionic crystals this potential energy function can be written down with some precision. To keep the expression tractable, the dominant electron deformation, the dipolar deformation, is treated as an adiabatic variable and the energy then becomes a function of both the nuclear coordinates and the ionic dipole moments. All the well known models for ionic crystals are discussed in terms of the energy expression they imply. This makes the comparison straight forward and brings out the essential difference between the models clearly. Next various quantum mechanical treatments for ionic crystals are reviewed. An attempt is made to obtain the B-O potential energy expression using a Heitler-London approach. By comparing the various models one can arrive at some definitive conclusions about the degree of validity and the assumptions underlying these models. Finally a comprehensive review of the results of actual computation on various ionic crystals done by different authors is undertaken. The crucial quantitative results are examined and the success and shortcoming of each calculation are critically analysed. The guiding principle in this part is the unified approach. i.e. to see how far a model with a given set of parameters accounts for both the dynamic and static properties. The discussion is divided in three sections for crystals with sodium chloride, cesium chloride and zinc sulfide structures. Outstanding problems and difficulties in the present understanding are pointed out. (auth.)
Evaluation of a New Prototype Geodetic Astrolabe for Measuring Deflections of the Vertical
Slater, J. A.; Thompson, N.; Angell, L. E.; Belenkii, M. S.; Bruns, D. G.; Johnson, D. O.
2009-12-01
During the last three years, the National Geospatial-Intelligence Agency (NGA), with assistance from the U.S. Naval Observatory (USNO), sponsored the development of a new electronic geodetic astrolabe for measuring deflections of the vertical (DoV). NGA’s current operational astrolabes, built in 1995, have a number of undesirable features including the need for a pool of liquid mercury as a reflecting surface. The new state-of-the-art prototype instrument, completed by Trex Enterprises in early 2009, was designed to meet a 0.2 arcsec accuracy requirement. It reduces the weight, eliminates the mercury, and dramatically reduces observation times. The new astrolabe consists of a 101 mm aperture telescope with a 1.5° field of view and an inclinometer mounted inside a 92-cm high, 30-cm diameter tube, an external GPS receiver for timing, and a laptop computer that controls and monitors the instrument and performs the computations. Star images are recorded by an astronomical-grade camera with a 2,048 x 2,048 pixel CCD sensor that is externally triggered by time pulses from the GPS receiver. The prototype was designed for nighttime observation of visible stars equal to or brighter than magnitude 10.0. The inclinometer is a system of two orthogonal pendula that define the local gravitational vertical, each consisting of a brass plumb bob suspended from an aluminized polymer ribbon set between two electrodes. An internal reference collimator is rigidly tied to the inclinometer and projects an array of reference points of light onto the CCD sensor. After the astrolabe is coarsely leveled to within 20 arcsec, voice coil actuators automatically adjust and maintain the inclinometer vertical to within 0.02 arcsec. Independent images are collected at 6 second intervals using a 200 msec exposure time. The CCD coordinates are determined for each star and a collimator reference point on each image. Stars are identified by referencing a customized star catalog produced by USNO. A
29 CFR 779.219 - Unified operation may be achieved without common control or common ownership.
2010-07-01
... Act May Apply; Enterprise Coverage Unified Operation Or Common Control § 779.219 Unified operation may... through “unified operation.” It is clear from the definition that if the described activities are performed through unified operation they will be part of the enterprise whether they are performed by one...
Self-force correction to geodetic spin precession in Kerr spacetime
Akcay, Sarp
2017-08-01
We present an expression for the gravitational self-force correction to the geodetic spin precession of a spinning compact object with small, but non-negligible mass in a bound, equatorial orbit around a Kerr black hole. We consider only conservative backreaction effects due to the mass of the compact object (m1), thus neglecting the effects of its spin s1 on its motion; i.e., we impose s1≪G m12/c and m1≪m2, where m2 is the mass parameter of the background Kerr spacetime. We encapsulate the correction to the spin precession in ψ , the ratio of the accumulated spin-precession angle to the total azimuthal angle over one radial orbit in the equatorial plane. Our formulation considers the gauge-invariant O (m1) part of the correction to ψ , denoted by Δ ψ , and is a generalization of the results of Akcay et al. [Classical Quantum Gravity 34, 084001 (2017), 10.1088/1361-6382/aa61d6] to Kerr spacetime. Additionally, we compute the zero-eccentricity limit of Δ ψ and show that this quantity differs from the circular orbit Δ ψcirc by a gauge-invariant quantity containing the gravitational self-force correction to general relativistic periapsis advance in Kerr spacetime. Our result for Δ ψ is expressed in a manner that readily accommodates numerical/analytical self-force computations, e.g., in the radiation gauge, and paves the way for the computation of a new eccentric-orbit Kerr gauge invariant beyond the generalized redshift.
Ohlendorf, S. J.; Feigl, K.; Thurber, C. H.; Lu, Z.; Masterlark, T.
2011-12-01
Okmok Volcano is an active caldera located on Umnak Island in the Aleutian Island arc. Okmok, having recently erupted in 1997 and 2008, is well suited for multidisciplinary studies of magma migration and storage because it hosts a good seismic network and has been the subject of synthetic aperture radar (SAR) images that span the recent eruption cycle. Interferometric SAR can characterize surface deformation in space and time, while data from the seismic network provides important information about the interior processes and structure of the volcano. We conduct a complete time series analysis of deformation of Okmok with images collected by the ERS and Envisat satellites on more than 100 distinct epochs between 1993 and 2008. We look for changes in inter-eruption inflation rates, which may indicate inelastic rheologic effects. For the time series analysis, we analyze the gradient of phase directly, without unwrapping, using the General Inversion of Phase Technique (GIPhT) [Feigl and Thurber, 2009]. This approach accounts for orbital and atmospheric effects and provides realistic estimates of the uncertainties of the model parameters. We consider several models for the source, including the prolate spheroid model and the Mogi model, to explain the observed deformation. Using a medium that is a homogeneous half space, we estimate the source depth to be centered at about 4 km below sea level, consistent with the findings of Masterlark et al. [2010]. As in several other geodetic studies, we find the source to be approximately centered beneath the caldera. To account for rheologic complexity, we next apply the Finite Element Method to simulate a pressurized cavity embedded in a medium with material properties derived from body wave seismic tomography. This approach allows us to address the problem of unreasonably large pressure values implied by a Mogi source with a radius of about 1 km by experimenting with larger sources. We also compare the time dependence of the
Directory of Open Access Journals (Sweden)
Inés Dussaillant
2018-02-01
Full Text Available We compare two independent estimates of the rate of elevation change and geodetic mass balance of the Northern Patagonian Icefield (NPI between 2000 (3,856 km2 and 2012 (3,740 km2 from space-borne data. The first is obtained by differencing the Shuttle Radar Topography Mission (SRTM digital elevation model (DEM from February 2000 and a Satellite pour l'Observation de la Terre 5 (SPOT5 DEM from March 2012. The second is deduced by fitting pixel-based linear elevation trends over 118 DEMs calculated from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER stereo images acquired between 2000 and 2012. Both methods lead to similar and strongly negative icefield-wide mass balance rates of −1.02 ± 0.21 and −1.06 ± 0.14 m w.e. yr−1 respectively, which is in agreement with earlier studies. Contrasting glacier responses are observed, with individual glacier mass balance rates ranging from −0.15 to −2.30 m w.e. yr−1 (standard deviation = 0.49 m w.e. yr−1; N = 38. For individual glaciers, the two methods agree within error bars, except for small glaciers poorly sampled in the SPOT5 DEM due to clouds. Importantly, our study confirms the lack of penetration of the C-band SRTM radar signal into the NPI snow and firn except for a region above 2,900 m a.s.l. covering <1% of the total area. Ignoring penetration would bias the mass balance by only 0.005 m w.e. yr−1. A strong advantage of the ASTER method is that it relies only on freely available data and can thus be extended to other glacierized areas.
Geodetic mass balance measurements on debris and clean-ice tropical glaciers in Ecuador
La Frenierre, J.; Decker, C. R.; Jordan, E.; Wigmore, O.; Hodge, B. E.; Niederriter, C.; Michels, A.
2017-12-01
Glaciers are recognized as highly sensitive indicators of climate change in high altitude, low latitude environments. In the tropical Andes, various analyses of glacier surface area change have helped illuminate the manifestation of climate change in this region, however, information about actual glacier mass balance behavior is much more limited given the relatively small glaciers, difficult access, poor weather, and/or limited local resources common here. Several new technologies, including aerial and terrestrial LIDAR and structure-from-motion photogrammetry using small unmanned aerial vehicles (UAVs), make mass balance measurements using geodetic approaches increasingly feasible in remote mountain locations, which can both further our understanding of changing climatic conditions, and improve our ability to evaluate the downstream hydrologic impacts of ice loss. At Volcán Chimborazo, Ecuador, these new technologies, combined with a unique, 5-meter resolution digital elevation model derived from 1997 aerial imagery, make possible an analysis of the magnitude and spatial patterns of mass balance behavior over the past two decades. Here, we evaluate ice loss between 1997 and 2017 at the tongues of two adjacent glaciers, one debris-covered and detached from its accumulation area (Reschreiter Glacier), and one debris-free and intact (Hans Meyer Glacier). Additionally, we incorporate data from 2012 and 2013 terrestrial LIDAR surveys to evaluate the behavior of the Reschreiter at a finer temporal resolution. We find that on the Hans Meyer, the mean surface deflation rate since 1997 at the present-day tongue has been nearly 3 m yr-1, while on the lower-elevation Reschreiter, the mean deflation rate has been approximately 1 m yr-1. However, the processes by which debris-covered ice becomes exposed results in highly heterogeneous patterns of ice loss, with some areas experiencing surface deflation rates approaching 15 m yr-1 when energy absorption is unimpeded.
Wińska, Małgorzata; Nastula, Jolanta
2017-04-01
Large scale mass redistribution and its transport within the Earth system causes changes in the Earth's rotation in space, gravity field and Earth's ellipsoid shape. These changes are observed in the ΔC21, ΔS21, and ΔC20 spherical harmonics gravity coefficients, which are proportional to the mass load-induced Earth rotational excitations. In this study, linear trend, decadal, inter-annual, and seasonal variations of low degree spherical harmonics coefficients of Earth's gravity field, determined from different space geodetic techniques, Gravity Recovery and Climate Experiment (GRACE), satellite laser ranging (SLR), Global Navigation Satellite System (GNSS), Earth rotation, and climate models, are examined. In this way, the contribution of each measurement technique to interpreting the low degree surface mass density of the Earth is shown. Especially, we evaluate an usefulness of several climate models from the Coupled Model Intercomparison Project phase 5 (CMIP5) to determine the low degree Earth's gravity coefficients using GRACE satellite observations. To do that, Terrestrial Water Storage (TWS) changes from several CMIP5 climate models are determined and then these simulated data are compared with the GRACE observations. Spherical harmonics ΔC21, ΔS21, and ΔC20 changes are calculated as the sum of atmosphere and ocean mass effect (GAC values) taken from GRACE and a land surface hydrological estimate from the selected CMIP5 climate models. Low degree Stokes coefficients of the surface mass density determined from GRACE, SLR, GNSS, Earth rotation measurements and climate models are compared to each other in order to assess their consistency. The comparison is done by using different types of statistical and signal processing methods.
From Geodetic Imaging of Seismic and Aseismic Fault Slip to Dynamic Modeling of the Seismic Cycle
Avouac, Jean-Philippe
2015-05-01
Understanding the partitioning of seismic and aseismic fault slip is central to seismotectonics as it ultimately determines the seismic potential of faults. Thanks to advances in tectonic geodesy, it is now possible to develop kinematic models of the spatiotemporal evolution of slip over the seismic cycle and to determine the budget of seismic and aseismic slip. Studies of subduction zones and continental faults have shown that aseismic creep is common and sometimes prevalent within the seismogenic depth range. Interseismic coupling is generally observed to be spatially heterogeneous, defining locked patches of stress accumulation, to be released in future earthquakes or aseismic transients, surrounded by creeping areas. Clay-rich tectonites, high temperature, and elevated pore-fluid pressure seem to be key factors promoting aseismic creep. The generally logarithmic time evolution of afterslip is a distinctive feature of creeping faults that suggests a logarithmic dependency of fault friction on slip rate, as observed in laboratory friction experiments. Most faults can be considered to be paved with interlaced patches where the friction law is either rate-strengthening, inhibiting seismic rupture propagation, or rate-weakening, allowing for earthquake nucleation. The rate-weakening patches act as asperities on which stress builds up in the interseismic period; they might rupture collectively in a variety of ways. The pattern of interseismic coupling can help constrain the return period of the maximum- magnitude earthquake based on the requirement that seismic and aseismic slip sum to match long-term slip. Dynamic models of the seismic cycle based on this conceptual model can be tuned to reproduce geodetic and seismological observations. The promise and pitfalls of using such models to assess seismic hazard are discussed.
Recent surface displacements in the Upper Rhine Graben — Preliminary results from geodetic networks
Fuhrmann, Thomas; Heck, Bernhard; Knöpfler, Andreas; Masson, Frédéric; Mayer, Michael; Ulrich, Patrice; Westerhaus, Malte; Zippelt, Karl
2013-08-01
Datasets of the GNSS Upper Rhine Graben Network (GURN) and the national levelling networks in Germany, France and Switzerland are investigated with respect to current surface displacements in the Upper Rhine Graben (URG) area. GURN consists of about 80 permanent GNSS (Global Navigation Satellite Systems) stations. The terrestrial levelling network comprises 1st and 2nd order levelling lines that have been remeasured at intervals of roughly 25 years, starting in 1922. Compared to earlier studies national institutions and private companies made available raw data, allowing for consistent solutions for the URG region. We focussed on the southern and eastern parts of the investigation area. Our preliminary results show that the levelling and GNSS datasets are sensitive to resolve small surface displacement rates down to an order of magnitude of 0.2 mm/a and 0.4 mm/a, respectively. The observed horizontal velocity components for a test region south of Strasbourg, obtained from GNSS coordinate time series, vary around 0.5 mm/a. The results are in general agreement with interseismic strain built-up in a sinistral strike-slip regime. Since the accuracy of the GNSS derived vertical component is insufficient, data of precise levelling networks is used to determine vertical displacement rates. More than 75% of the vertical rates obtained from a kinematic adjustment of 1st order levelling lines in the eastern part of URG vary between - 0.2 mm/a and + 0.2 mm/a, indicating that this region behaves stable. Higher rates up to 0.5 mm/a in a limited region south of Freiburg are in general agreement with active faulting. We conclude that both networks deliver stable results that reflect real surface movements in the URG area. We note, however, that geodetically observed surface displacements generally result from a superposition of different effects, and that a separation in tectonic and non-tectonic processes needs additional information and expertise.
Geodetic integration of Sentinel-1A IW data using PSInSAR in Hungary
Farkas, Péter; Hevér, Renáta; Grenerczy, Gyula
2015-04-01
ESA's latest Synthetic Aperture Radar (SAR) mission Sentinel-1 is a huge step forward in SAR interferometry. With its default acquisition mode called the Interferometric Wide Swath Mode (IW) areas through all scales can be mapped with an excellent return time of 12 days (while only the Sentinel-1A is in orbit). Its operational data policy is also a novelty, it allows scientific users free and unlimited access to data. It implements a new type of ScanSAR mode called Terrain Observation with Progressive Scan (TOPS) SAR. It has the same resolution as ScanSAR but with better signal-to-noise ratio distribution. The bigger coverage is achieved by rotation of the antenna in the azimuth direction, therefore it requires very precise co-registration because even errors under a pixel accuracy can introduce azimuth phase variations caused by differences in Doppler-centroids. In our work we will summarize the benefits and the drawbacks of the IW mode. We would like to implement the processing chain of GAMMA Remote Sensing of such data for mapping surface motion with special attention to the co-registration step. Not only traditional InSAR but the advanced method of Persistent Scatterer InSAR (PSInSAR) will be performed and presented as well. PS coverage, along with coherence, is expected to be good due to the small perpendicular and temporal baselines. We would also like to integrate these measurements into national geodetic networks using common reference points. We have installed trihedral corner reflectors at some selected sites to aid precise collocation. Thus, we aim to demonstrate that Sentinel-1 can be effectively used for surface movement detection and monitoring and it can also provide valuable information for the improvement of our networks.
Menteşe, E. Y.; Kilic, O.; BAS, M.; Tarih, A.; Duran, K.; Gumus, S.; Yapar, E. R.; Karasu, M. E.; Mehmetoğlu, H.; Karaman, A.; Edi˙ger, V.; Kosma, R. C.; Ozalaybey, S.; Zor, E.; Arpat, E.; Polat, F.; Dogan, U.; Cakir, Z.; Erkan, B.
2017-12-01
There are several methods that can be utilized for describing the landslide mechanisms. While some of them are commonly used, there are relatively new methods that have been proven to be useful. Obviously, each method has its own limitations and thus integrated use of these methods contributes to obtaining a realistic landslide model. The slopes of Küçükçekmece and Büyükçekmece Lagoons located at the Marmara Sea coast of İstanbul, Turkey, are among most specific examples of complex type landslides. The landslides in the area started developing at low sea level, and appears to ceased or at least slowed down to be at minimum after the sea level rise, as oppose to the still-active landslides that continue to cause damage especially in the valley slopes above the recent sea level between the two lagoons. To clarify the characteristics of these slope movements and classify them in most accurate way, Directorate of Earthquake and Ground Research of Istanbul Metropolitan Municipality launched a project in cooperation with Marmara Research Center of The Scientific and Technological Research Council of Turkey (TÜBİTAK). The project benefits the utility of the techniques of different disciplines such as geology, geophysics, geomorphology, hydrogeology, geotechnics, geodesy, remote sensing and meteorology. Specifically, this study focuses on two main axes of these techniques, namely: geological and geodetic. The reason for selecting these disciplines is because of their efficiency and power to understand the landslide mechanism in the area. Main approaches used in these studies are comprised of geological drills, inclinometer measurements, GPS surveys and SAR (both satellite and ground based) techniques. Integration of the results gathered from these techniques led the project team to comprehend critical aspects of landslide phenomenon in the area and produce precise landslide hazard maps that are basic instruments for a resilient urban development.
NChina16: A stable geodetic reference frame for geological hazard studies in North China
Wang, Guoquan; Bao, Yan; Gan, Weijun; Geng, Jianghui; Xiao, Gengru; Shen, Jack S.
2018-04-01
We have developed a stable North China Reference Frame 2016 (NChina16) using five years of continuous GPS observations (2011.8-2016.8) from 12 continuously operating reference stations (CORS) fixed to the North China Craton. Applications of NChina16 in landslide and subsidence studies are illustrated in this article. A method for realizing a regional geodetic reference frame is introduced. The primary result of this study is the seven parameters for transforming Cartesian ECEF (Earth-Centered, Earth-Fixed) coordinates X, Y, and Z from the International GNSS Service Reference Frame 2008 (IGS08) to NChina16. The seven parameters include the epoch that is used to align the regional reference frame to IGS08 and the time derivatives of three translations and three rotations. The GIPSY-OASIS (V6.4) software package was used to obtain the precise point positioning (PPP) daily solutions with respect to IGS08. The frame stability of NChina16 is approximately 0.5 mm/year in both horizontal and vertical directions. This study also developed a regional model for correcting seasonal motions superimposed into the vertical component of the GPS-derived displacement time series. Long-term GPS observations (1999-2016) from five CORS in North China were used to develop the seasonal model. According to this study, the PPP daily solutions with respect to NChina16 could achieve 2-3 mm horizontal accuracy and 4-5 mm vertical accuracy after being modified by the regional model. NChina16 will be critical to study geodynamic problems in North China, such as earthquakes, faulting, subsidence, and landslides. The regional reference frame will be periodically updated every few years to mitigate degradation of the frame with time and be synchronized with the update of IGS reference frame.
Niemi, N. A.; Clark, M. K.
2017-12-01
For the past 6 years, the University of Michigan has implemented geodetic techniques into both summer field courses and on-campus courses. The primary means for incorporating these technologies has been a partnership with UNAVCO to introduce terrestrial laser scanning (TLS) at summer field courses, although employing Structure from Motion(SfM), ArcCollector for iPads and RTK GPS surveying have also been explored. The nature of these types of data lend themselves readily to geomorphology, environmental, and natural hazards-based projects, and we have developed field projects or labs around neotectonics (fault-scarp scanning and diffusion analysis), change detection (braided stream evolution, landslide and rock glacier motion, coastal change) and mass wasting processes (rock avalanche scanning and analysis). While we have primarily developed multi-day projects that use these tools in a field camp setting, we have also developed weekend field trip projects and traditional afternoon lab exercises associated with on-campus courses. The use of geodetic technology is generally well received by students. Reasons for this are the use of somewhat different skill sets from traditional geologic mapping problems, including research survey design, real-time data acquisition, and quantitative data analysis. Students also perceive that they are engaged in learning technology which they may use in their future employment. Challenges encountered, particularly in the field, include managing large student groups with a finite pool of equipment, rapid data processing pressures, variable student experience with analysis software and limited technical support for field-based computational resources. We will describe the positive attributes of incorporating geodetic technologies into undergraduate courses and elaborate on some best practices learned from our experiences.
Bartlow, N. M.
2017-12-01
Slow Earthquake Hunters is a new citizen science project to detect, catalog, and monitor slow slip events. Slow slip events, also called "slow earthquakes", occur when faults slip too slowly to generate significant seismic radiation. They typically take between a few days and over a year to occur, and are most often found on subduction zone plate interfaces. While not dangerous in and of themselves, recent evidence suggests that monitoring slow slip events is important for earthquake hazards, as slow slip events have been known to trigger damaging "regular" earthquakes. Slow slip events, because they do not radiate seismically, are detected with a variety of methods, most commonly continuous geodetic Global Positioning System (GPS) stations. There is now a wealth of GPS data in some regions that experience slow slip events, but a reliable automated method to detect them in GPS data remains elusive. This project aims to recruit human users to view GPS time series data, with some post-processing to highlight slow slip signals, and flag slow slip events for further analysis by the scientific team. Slow Earthquake Hunters will begin with data from the Cascadia subduction zone, where geodetically detectable slow slip events with a duration of at least a few days recur at regular intervals. The project will then expand to other areas with slow slip events or other transient geodetic signals, including other subduction zones, and areas with strike-slip faults. This project has not yet rolled out to the public, and is in a beta testing phase. This presentation will show results from an initial pilot group of student participants at the University of Missouri, and solicit feedback for the future of Slow Earthquake Hunters.
Kyriakopoulos, Christos; Oglesby, David D.; Funning, Gareth J.; Ryan, Kenneth
2017-01-01
The 2010 Mw 7.2 El Mayor-Cucapah earthquake is the largest event recorded in the broader Southern California-Baja California region in the last 18 years. Here we try to analyze primary features of this type of event by using dynamic rupture simulations based on a multifault interface and later compare our results with space geodetic models. Our results show that starting from homogeneous prestress conditions, slip heterogeneity can be achieved as a result of variable dip angle along strike and the modulation imposed by step over segments. We also considered effects from a topographic free surface and find that although this does not produce significant first-order effects for this earthquake, even a low topographic dome such as the Cucapah range can affect the rupture front pattern and fault slip rate. Finally, we inverted available interferometric synthetic aperture radar data, using the same geometry as the dynamic rupture model, and retrieved the space geodetic slip distribution that serves to constrain the dynamic rupture models. The one to one comparison of the final fault slip pattern generated with dynamic rupture models and the space geodetic inversion show good agreement. Our results lead us to the following conclusion: in a possible multifault rupture scenario, and if we have first-order geometry constraints, dynamic rupture models can be very efficient in predicting large-scale slip heterogeneities that are important for the correct assessment of seismic hazard and the magnitude of future events. Our work contributes to understanding the complex nature of multifault systems.
Cristofoletti, P.; Esposito, A.; Anzidei, M.
2003-04-01
This paper presents the methodologies and issues involved in the use of GIS techniques to manage geodetic information derived from networks in seismic and volcanic areas. Organization and manipulation of different geodetical, geological and seismic database, give us a new challenge in interpretation of information that has several dimensions, including spatial and temporal variations, also the flexibility and brand range of tools available in GeoNetGIS, make it an attractive platform for earthquake risk assessment. During the last decade the use of geodetic networks based on the Global Positioning System, devoted to geophysical applications, especially for crustal deformation monitoring in seismic and volcanic areas, increased dramatically. The large amount of data provided by these networks, combined with different and independent observations, such as epicentre distribution of recent and historical earthquakes, geological and structural data, photo interpretation of aerial and satellite images, can aid for the detection and parameterization of seismogenic sources. In particular we applied our geodetic oriented GIS to a new GPS network recently set up and surveyed in the Central Apennine region: the CA-GeoNet. GeoNetGIS is designed to analyze in three and four dimensions GPS sources and to improve crustal deformation analysis and interpretation related with tectonic structures and seismicity. It manages many database (DBMS) consisting of different classes, such as Geodesy, Topography, Seismicity, Geology, Geography and Raster Images, administrated according to Thematic Layers. GeoNetGIS represents a powerful research tool allowing to join the analysis of all data layers to integrate the different data base which aid for the identification of the activity of known faults or structures and suggesting the new evidences of active tectonics. A new approach to data integration given by GeoNetGIS capabilities, allow us to create and deliver a wide range of maps, digital
Cervelli, Peter Francis
2002-09-01
Paradoxically, one of the greatest hazards associated with oceanic volcanoes is not volcanic. Rather, it is the potential for catastrophic flank failure resulting in devastating tsunamis, which threaten not just the immediate vicinity, but coastal cities along the entire rim of an ocean basin. Kilauea volcano on the Island of Hawaii, USA, a potential source of such flank failures, is monitored by a network of continuously recording geodetic instruments, including Global Positioning System (GPS) receivers, tiltmeters, and strainmeters. In this thesis, methodology is developed for using these geodetic data to estimate the geometry and type of active deformation sources, such as dikes, magma chambers, and faults. The methodology is then applied to two episodes of deformation that occurred at Kilauea Volcano in 1999 and 2000. First, the deformation associated with an earthquake swarm on September 12, 1999 in the Upper East Rift Zone of Kilauea Volcano, which was recorded by continuous GPS receivers, tiltmeters, campaign GPS, leveling, and InSAR, is analyzed and interpreted as a west to east propagating dike intrusion. Lack of premonitory inflation of Kilauea's summit suggests that the immediate cause of the intrusion was probably tensile failure in the shallow crust of the Upper East Rift, rather than forceful magma injection. Second, in early November 2000, the geodetic network recorded transient southeastward displacements, which we interpret as an episode of aseismic fault slip. The duration of the event was about 36 hours; it had an equivalent moment magnitude of M5.7, and a maximum slip velocity of about 6 cm/day. Inversion of the GPS data images a shallowly dipping thrust at a depth of 4.5 km that we interpret as the down dip extension of the Hilina Pali fault system. Thus it is demonstrated that continuous geodetic networks can detect accelerating slip, potentially leading to warnings of imminent volcanic flank collapse. Finally, in the last chapter of the
4-D Visualization of Seismic and Geodetic Data of the Big Island of Hawai'i
Burstein, J. A.; Smith-Konter, B. R.; Aryal, A.
2017-12-01
For decades Hawai'i has served as a natural laboratory for studying complex interactions between magmatic and seismic processes. Investigating characteristics of these processes, as well as the crustal response to major Hawaiian earthquakes, requires a synthesis of seismic and geodetic data and models. Here, we present a 4-D visualization of the Big Island of Hawai'i that investigates geospatial and temporal relationships of seismicity, seismic velocity structure, and GPS crustal motions to known volcanic and seismically active features. Using the QPS Fledermaus visualization package, we compile 90 m resolution topographic data from NASA's Shuttle Radar Topography Mission (SRTM) and 50 m resolution bathymetric data from the Hawaiian Mapping Research Group (HMRG) with a high-precision earthquake catalog of more than 130,000 events from 1992-2009 [Matoza et al., 2013] and a 3-D seismic velocity model of Hawai'i [Lin et al., 2014] based on seismic data from the Hawaiian Volcano Observatory (HVO). Long-term crustal motion vectors are integrated into the visualization from HVO GPS time-series data. These interactive data sets reveal well-defined seismic structure near the summit areas of Mauna Loa and Kilauea volcanoes, where high Vp and high Vp/Vs anomalies at 5-12 km depth, as well as clusters of low magnitude (M data are also used to help identify seismic clusters associated with the steady crustal detachment of the south flank of Kilauea's East Rift Zone. We also investigate the fault geometry of the 2006 M6.7 Kiholo Bay earthquake event by analyzing elastic dislocation deformation modeling results [Okada, 1985] and HVO GPS and seismic data of this event. We demonstrate the 3-D fault mechanisms of the Kiholo Bay main shock as a combination of strike-slip and dip-slip components (net slip 0.55 m) delineating a 30 km east-west striking, southward-dipping fault plane, occurring at 39 km depth. This visualization serves as a resource for advancing scientific analyses of
McWhirter, J.; Boler, F. M.; Bock, Y.; Jamason, P.; Squibb, M. B.; Noll, C. E.; Blewitt, G.; Kreemer, C. W.
2010-12-01
Three geodesy Archive Centers, Scripps Orbit and Permanent Array Center (SOPAC), NASA's Crustal Dynamics Data Information System (CDDIS) and UNAVCO are engaged in a joint effort to define and develop a common Web Service Application Programming Interface (API) for accessing geodetic data holdings. This effort is funded by the NASA ROSES ACCESS Program to modernize the original GPS Seamless Archive Centers (GSAC) technology which was developed in the 1990s. A new web service interface, the GSAC-WS, is being developed to provide uniform and expanded mechanisms through which users can access our data repositories. In total, our respective archives hold tens of millions of files and contain a rich collection of site/station metadata. Though we serve similar user communities, we currently provide a range of different access methods, query services and metadata formats. This leads to a lack of consistency in the userís experience and a duplication of engineering efforts. The GSAC-WS API and its reference implementation in an underlying Java-based GSAC Service Layer (GSL) supports metadata and data queries into site/station oriented data archives. The general nature of this API makes it applicable to a broad range of data systems. The overall goals of this project include providing consistent and rich query interfaces for end users and client programs, the development of enabling technology to facilitate third party repositories in developing these web service capabilities and to enable the ability to perform data queries across a collection of federated GSAC-WS enabled repositories. A fundamental challenge faced in this project is to provide a common suite of query services across a heterogeneous collection of data yet enabling each repository to expose their specific metadata holdings. To address this challenge we are developing a "capabilities" based service where a repository can describe its specific query and metadata capabilities. Furthermore, the architecture of
Application of ray-traced tropospheric slant delays to geodetic VLBI analysis
Hofmeister, Armin; Böhm, Johannes
2017-08-01
The correction of tropospheric influences via so-called path delays is critical for the analysis of observations from space geodetic techniques like the very long baseline interferometry (VLBI). In standard VLBI analysis, the a priori slant path delays are determined using the concept of zenith delays, mapping functions and gradients. The a priori use of ray-traced delays, i.e., tropospheric slant path delays determined with the technique of ray-tracing through the meteorological data of numerical weather models (NWM), serves as an alternative way of correcting the influences of the troposphere on the VLBI observations within the analysis. In the presented research, the application of ray-traced delays to the VLBI analysis of sessions in a time span of 16.5 years is investigated. Ray-traced delays have been determined with program RADIATE (see Hofmeister in Ph.D. thesis, Department of Geodesy and Geophysics, Faculty of Mathematics and Geoinformation, Technische Universität Wien. http://resolver.obvsg.at/urn:nbn:at:at-ubtuw:1-3444, 2016) utilizing meteorological data provided by NWM of the European Centre for Medium-Range Weather Forecasts (ECMWF). In comparison with a standard VLBI analysis, which includes the tropospheric gradient estimation, the application of the ray-traced delays to an analysis, which uses the same parameterization except for the a priori slant path delay handling and the used wet mapping factors for the zenith wet delay (ZWD) estimation, improves the baseline length repeatability (BLR) at 55.9% of the baselines at sub-mm level. If no tropospheric gradients are estimated within the compared analyses, 90.6% of all baselines benefit from the application of the ray-traced delays, which leads to an average improvement of the BLR of 1 mm. The effects of the ray-traced delays on the terrestrial reference frame are also investigated. A separate assessment of the RADIATE ray-traced delays is carried out by comparison to the ray-traced delays from the
Geodetic Insights into the Earthquake Cycle in a Fold and Thrust Belt
Ingleby, T. F.; Wright, T. J.; Butterworth, V.; Weiss, J. R.; Elliott, J.
2017-12-01
Geodetic measurements are often sparse in time (e.g. individual interferograms) and/or space (e.g. GNSS stations), adversely affecting our ability to capture the spatiotemporal detail required to study the earthquake cycle in complex tectonic systems such as subaerial fold and thrust belts. In an effort to overcome these limitations we combine 3 generations of SAR satellite data (ERS 1/2, Envisat & Sentinel-1a/b) to obtain a 25 year, high-resolution surface displacement time series over the frontal portion of an active fold and thrust belt near Quetta, Pakistan where a Mw 7.1 earthquake doublet occurred in 1997. With these data we capture a significant portion of the seismic cycle including the interseismic, coseismic and postseismic phases. Each satellite time series has been referenced to the first ERS-1 SAR epoch by fitting a ground deformation model to the data. This allows us to separate deformation associated with each phase and to examine their relative roles in accommodating strain and creating topography, and to explore the relationship between the earthquake cycle and critical taper wedge mechanics. Modeling of the coseismic deformation suggests a long, thin rupture with rupture length 7 times greater than rupture width. Rupture was confined to a 20-30 degree north-northeast dipping reverse fault or ramp at depth, which may be connecting two weak decollements at approximately 8 km and 13 km depth. Alternatively, intersections between the coseismic fault plane and pre-existing steeper splay faults underlying folds may have played a significant role in inhibiting rupture, as evidenced by intersection points bordering the rupture. These fault intersections effectively partition the fault system down-dip and enable long, thin ruptures. Postseismic deformation is manifest as uplift across short-wavelength folds at the thrust front, with displacement rates decreasing with time since the earthquake. Broader patterns of postseismic uplift are also observed
Space-geodetic Constraints on GIA Models with 3D Viscosity
Van Der Wal, W.; Xu, Z.
2012-12-01
Models for Glacial Isostatic Adjustment (GIA) are an important correction to observations of mass change in the polar regions. Inputs for GIA models include past ice thickness and deformation parameters of the Earth's mantle, both of which are imperfectly known. Here we focus on the latter by investigating GIA models with 3D viscosity and composite (linear and non-linear) flow laws. It was found recently that GIA models with a composite flow law result in a better fit to historic sea level data, but they predict too low present-day uplift rates and gravity rates. Here GIA models are fit to space-geodetic constraints in Fennoscandia and North America. The preferred models are used to calculate the magnitude of the GIA correction on mass change estimates in Greenland and Antarctica. The observations used are GRACE Release 4 solutions from CSR and GFZ and published GPS solutions for North America and Fennoscandia, as well as historic sea level data. The GIA simulations are performed with a finite element model of a spherical, self-gravitating, incompressible Earth with 2x2 degree elements. Parameters in the flow laws are taken from seismology, heatflow measurements and experimental constraints and the ice loading history is prescribed by ICE-5G. It was found that GRACE and GPS derived uplift rates agree at the level of 1 mm/year in North America and at a level of 0.5 mm/year in Fennoscandia, the difference between the two regions being due to larger GPS errors and under sampling in North America. It can be concluded that both GPS and GRACE see the same process and the effects of filtering, noise and non-GIA processes such as land hydrology are likely to be small. Two GIA models are found that bring present-day uplift rate close to observed values in North America and Fennoscandia. These models result in a GIA correction of -17 Gt/year and -26 Gt/year on Greenland mass balance estimates from GRACE.
La Femina, P. C.; Klippel, A.; Zhao, J.; Walgruen, J. O.; Stubbs, C.; Jackson, K. L.; Wetzel, R.
2017-12-01
High-quality geodetic data and data products, including GPS-GNSS, InSAR, LiDAR, and Structure from Motion (SfM) are opening the doors to visualizing, quantifying, and modeling geologic, tectonic, geomorphic, and geodynamic processes. The integration of these data sets with other geophysical, geochemical and geologic data is providing opportunities for the development of immersive Virtual Reality (iVR) field trips in the geosciences. iVR fieldtrips increase accessibility in the geosciences, by providing experiences that allow for: 1) exploration of field locations that might not be tenable for introductory or majors courses; 2) accessibility to outcrops for students with physical disabilities; and 3) the development of online geosciences courses. We have developed a workflow for producing iVR fieldtrips and tools to make quantitative observations (e.g., distance, area, and volume) within the iVR environment. We use a combination of terrestrial LiDAR and SfM data, 360° photos and videos, and other geophysical, geochemical and geologic data to develop realistic experiences for students to be exposed to the geosciences from sedimentary geology to physical volcanology. We present two of our iVR field trips: 1) Inside the Volcano: Exploring monogenetic volcanism at Thrihnukagigar Iceland; and 2) Changes in Depositional Environment in a Sedimentary Sequence: The Reedsville and Bald Eagle Formations, Pennsylvania. The Thrihnukagigar experience provides the opportunity to investigate monogenetic volcanism through the exploration of the upper 125 m of a fissure-cinder cone eruptive system. Students start at the plate boundary scale, then zoom into a single volcano where they can view the 3D geometry from either terrestrial LiDAR or SfM point clouds, view geochemical data and petrologic thins sections of rock samples, and a presentation of data collection and analysis, results and interpretation. Our sedimentary geology experience is based on a field lab from our
Geodetic Infrastructure in the Ibiza and Barcelona Harbours for Sea Level Monitoring
Martinez-Benjamin, J. J.; Gili, J.; Lopez, R.; Tapia, A.; Perez, B.; Pros, F.
2013-12-01
The presentation is directed to the description of the actual situation and relevant information of the geodetic infrastructure of Ibiza and Barcelona sites for sea level determination and contribution to regional sea level rise. Time series are being analysed for mean sea level variations www.puertos.es. .In the framework of a Spanish Space Project, the instrumentation of sea level measurements has been improved by providing the Barcelona site with a radar tide gauge Datamar 2000C from Geonica s.l. near an acoustic tide gauge. Puertos del Estado installed in 2007 a MIROS radar tide gauge and the Barcelona Harbour Authority a GPS referente station in the roof of the new Control Tower situated in the Energy Pier. The radar sensor is over the water surface, on a L-shaped structure which elevates it a few meters above the quay shelf. 1-min data are transmitted to the ENAGAS Control Center by cable and then sent each 1 min to Puertos del Estado by e-mail. There is a GPS station Leica Geosystems GRX1200 GG Pro and antenna 1202. Precision levelling has been made several times in the last two years because the tower is founded in reclaimed land. The measured settlement rate is about 1cm/year that may be could mask the values registered by the tide gauge. A description of the actual infrastructure at Ibiza harbour at Marina de Botafoch, is presented and its applications to sea level monitoring and altimeter calibration in support of the main CGPS at Ibiza harbour. It is described the geometrical precision levelling made in June 2013 between the radar tide gauge and the GPS station. In particular, the CGPS located at Ibiza harbour is essential for its application to the marine campaign Baleares 2013, near Ibiza island. The main objective is to determine the altimeter bias for Jason-2, about 9:09 UTC September 15, 2013, and Saral/AltiKa, about 05:30 UTC September 16, UTC. These activities has been received funding of the Ministerio de Ciencia e Innovacion under Spanish
Osada, Y.; Ohta, Y.; Demachi, T.; Kido, M.; Fujimoto, H.; Azuma, R.; Hino, R.
2013-12-01
Large interplate earthquake repeatedly occurred in Japan Trench. Recently, the detail crustal deformation revealed by the nation-wide inland GPS network called as GEONET by GSI. However, the maximum displacement region for interplate earthquake is mainly located offshore region. GPS/Acoustic seafloor geodetic observation (hereafter GPS/A) is quite important and useful for understanding of shallower part of the interplate coupling between subducting and overriding plates. We typically conduct GPS/A in specific ocean area based on repeated campaign style using research vessel or buoy. Therefore, we cannot monitor the temporal variation of seafloor crustal deformation in real time. The one of technical issue on real time observation is kinematic GPS analysis because kinematic GPS analysis based on reference and rover data. If the precise kinematic GPS analysis will be possible in the offshore region, it should be promising method for real time GPS/A with USV (Unmanned Surface Vehicle) and a moored buoy. We assessed stability, precision and accuracy of StarFireTM global satellites based augmentation system. We primarily tested for StarFire in the static condition. In order to assess coordinate precision and accuracy, we compared 1Hz StarFire time series and post-processed precise point positioning (PPP) 1Hz time series by GIPSY-OASIS II processing software Ver. 6.1.2 with three difference product types (ultra-rapid, rapid, and final orbits). We also used difference interval clock information (30 and 300 seconds) for the post-processed PPP processing. The standard deviation of real time StarFire time series is less than 30 mm (horizontal components) and 60 mm (vertical component) based on 1 month continuous processing. We also assessed noise spectrum of the estimated time series by StarFire and post-processed GIPSY PPP results. We found that the noise spectrum of StarFire time series is similar pattern with GIPSY-OASIS II processing result based on JPL rapid orbit
Hreinsdottir, Sigrun
2005-07-01
GPS geodetic measurements are used to study two major earthquakes, the 2001 MW 7.7 El Salvador and 2002 MW 7.9 Denali Fault earthquakes. The 2001 MW 7.7 earthquake was a normal fault event in the subducting Cocos plate offshore El Salvador. Coseismic displacements of up to 15 mm were measured at permanent GPS stations in Central America. The GPS data were used to constrain the location of and slip on the normal fault. One month later a MW 6.6 strike-slip earthquake occurred in the overriding Caribbean plate. Coulomb stress changes estimated from the M W 7.7 earthquake suggest that it triggered the MW 6.6 earthquake. Coseismic displacement from the MW 6.6 earthquake, about 40 mm at a GPS station in El Salvador, indicates that the earthquake triggered additional slip on a fault close to the GPS station. The MW 6.6 earthquake further changed the stress field in the overriding Caribbean plate, with triggered seismic activity occurring west and possibly also to the east of the rupture in the days to months following the earthquake. The MW 7.9 Denali Fault earthquake ruptured three faults in the interior of Alaska. It initiated with a thrust motion on the Susitna Glacier fault but then ruptured the Denali and Totschunda faults with predominantly right-lateral strike-slip motion unilaterally from west to east. GPS data measured in the two weeks following the earthquake suggest a complex coseismic rupture along the faults with two main regions of moment release along the Denali fault. A large amount of additional data were collected in the year following the earthquake which greatly improved the resolution on the fault, revealing more details of the slip distribution. We estimate a total moment release of 6.81 x 1020 Nm in the earthquake with a M W 7.2 thrust subevent on Susitna Glacier fault. The slip on the Denali fault is highly variable, with 4 main pulses of moment release. The largest moment pulse corresponds to a MW 7.5 subevent, about 40 km west of the Denali
Nothing From Everything- A Unified Theory
Mehra, Vijay Kumar
2016-07-01
Nothing From Everything-A Unified Theory is a philosophical insight into principles of nature through principle of complementary spontaneity and principle of vertical continuity. This work is intended to explain various cosmological phenomena in light of behaviour of particles in range of their respective and relative speed of light. This theory explains creation of Universe from nothing or zero spacetime through scalar energy field collapsing into Higgs field resulting into giving mass to various particles. The energy particles taking origin from nothing while moving away from zero space-time would create space-time of their own order because energy/matter needs space to exist. The particles while moving away from zero space-time would end up in breaking symmetry of matter/energy at their mass infinity (highest possible mass of any particle, which is function of speed of spin). This break in symmetry would lead to curving of particles upon themselves and hence would lead to creation of antiparticles going back in time towards zero spacetime. Therefore the Universe could have been created by alternate layers of particles and antiparticles and also alternate layers of matter and antimatter with decelerating speed of light, which would lead to creation a closed and flat Universe. With increase in mass of Universe (creation of more and more Universe's matter from nothing), the gravitational force of Universe is bound to increase and hence with quantum by quantum increase in gravity, it would apply brakes on relative speed of photon/light out of its reference frame or designated space and hence speed of photon would decrease. If closed and flat Universe was created with decelerating speed of light, then such Universe is bound to contract back with accelerating speed of light which would have inverse impact on gravitational constant across various spacetime zones of Universe. And hence mass bodies would drift away spontaneously purely on basis and proportional to
An Adaptive Unified Differential Evolution Algorithm for Global Optimization
Energy Technology Data Exchange (ETDEWEB)
Qiang, Ji; Mitchell, Chad
2014-11-03
In this paper, we propose a new adaptive unified differential evolution algorithm for single-objective global optimization. Instead of the multiple mutation strate- gies proposed in conventional differential evolution algorithms, this algorithm employs a single equation unifying multiple strategies into one expression. It has the virtue of mathematical simplicity and also provides users the flexibility for broader exploration of the space of mutation operators. By making all control parameters in the proposed algorithm self-adaptively evolve during the process of optimization, it frees the application users from the burden of choosing appro- priate control parameters and also improves the performance of the algorithm. In numerical tests using thirteen basic unimodal and multimodal functions, the proposed adaptive unified algorithm shows promising performance in compari- son to several conventional differential evolution algorithms.
Unified Phase Diagram for Iron-Based Superconductors.
Gu, Yanhong; Liu, Zhaoyu; Xie, Tao; Zhang, Wenliang; Gong, Dongliang; Hu, Ding; Ma, Xiaoyan; Li, Chunhong; Zhao, Lingxiao; Lin, Lifang; Xu, Zhuang; Tan, Guotai; Chen, Genfu; Meng, Zi Yang; Yang, Yi-Feng; Luo, Huiqian; Li, Shiliang
2017-10-13
High-temperature superconductivity is closely adjacent to a long-range antiferromagnet, which is called a parent compound. In cuprates, all parent compounds are alike and carrier doping leads to superconductivity, so a unified phase diagram can be drawn. However, the properties of parent compounds for iron-based superconductors show significant diversity and both carrier and isovalent dopings can cause superconductivity, which casts doubt on the idea that there exists a unified phase diagram for them. Here we show that the ordered moments in a variety of iron pnictides are inversely proportional to the effective Curie constants of their nematic susceptibility. This unexpected scaling behavior suggests that the magnetic ground states of iron pnictides can be achieved by tuning the strength of nematic fluctuations. Therefore, a unified phase diagram can be established where superconductivity emerges from a hypothetical parent compound with a large ordered moment but weak nematic fluctuations, which suggests that iron-based superconductors are strongly correlated electron systems.
Unified Phase Diagram for Iron-Based Superconductors
Gu, Yanhong; Liu, Zhaoyu; Xie, Tao; Zhang, Wenliang; Gong, Dongliang; Hu, Ding; Ma, Xiaoyan; Li, Chunhong; Zhao, Lingxiao; Lin, Lifang; Xu, Zhuang; Tan, Guotai; Chen, Genfu; Meng, Zi Yang; Yang, Yi-feng; Luo, Huiqian; Li, Shiliang
2017-10-01
High-temperature superconductivity is closely adjacent to a long-range antiferromagnet, which is called a parent compound. In cuprates, all parent compounds are alike and carrier doping leads to superconductivity, so a unified phase diagram can be drawn. However, the properties of parent compounds for iron-based superconductors show significant diversity and both carrier and isovalent dopings can cause superconductivity, which casts doubt on the idea that there exists a unified phase diagram for them. Here we show that the ordered moments in a variety of iron pnictides are inversely proportional to the effective Curie constants of their nematic susceptibility. This unexpected scaling behavior suggests that the magnetic ground states of iron pnictides can be achieved by tuning the strength of nematic fluctuations. Therefore, a unified phase diagram can be established where superconductivity emerges from a hypothetical parent compound with a large ordered moment but weak nematic fluctuations, which suggests that iron-based superconductors are strongly correlated electron systems.
Mechanical systems a unified approach to vibrations and controls
Gans, Roger F
2015-01-01
This essential textbook covers analysis and control of engineering mechanisms, which include almost any apparatus with moving parts used in daily life, from musical instruments to robots. The text presents both vibrations and controls with considerable breadth and depth using a unified notation. It strikes a nice balance between the analytical and the practical. This text contains enough material for a two semester sequence, but it can also be used in a single semester course combining the two topics. Mechanical Systems: A Unified Approach to Vibrations and Controls presents a common notation and approach to these closely related areas. Examples from the both vibrations and controls components are integrated throughout this text. This book also: · Presents a unified approach to vibrations and controls, including an excellent diagram that simultaneously discusses embedding classical vibrations (mechanical systems) in a discussion of models, inverse models, and open and closed loop control ...
Canonical duality theory unified methodology for multidisciplinary study
Latorre, Vittorio; Ruan, Ning
2017-01-01
This book on canonical duality theory provides a comprehensive review of its philosophical origin, physics foundation, and mathematical statements in both finite- and infinite-dimensional spaces. A ground-breaking methodological theory, canonical duality theory can be used for modeling complex systems within a unified framework and for solving a large class of challenging problems in multidisciplinary fields in engineering, mathematics, and the sciences. This volume places a particular emphasis on canonical duality theory’s role in bridging the gap between non-convex analysis/mechanics and global optimization. With 18 total chapters written by experts in their fields, this volume provides a nonconventional theory for unified understanding of the fundamental difficulties in large deformation mechanics, bifurcation/chaos in nonlinear science, and the NP-hard problems in global optimization. Additionally, readers will find a unified methodology and powerful algorithms for solving challenging problems in comp...
a Unified Matrix Polynomial Approach to Modal Identification
Allemang, R. J.; Brown, D. L.
1998-04-01
One important current focus of modal identification is a reformulation of modal parameter estimation algorithms into a single, consistent mathematical formulation with a corresponding set of definitions and unifying concepts. Particularly, a matrix polynomial approach is used to unify the presentation with respect to current algorithms such as the least-squares complex exponential (LSCE), the polyreference time domain (PTD), Ibrahim time domain (ITD), eigensystem realization algorithm (ERA), rational fraction polynomial (RFP), polyreference frequency domain (PFD) and the complex mode indication function (CMIF) methods. Using this unified matrix polynomial approach (UMPA) allows a discussion of the similarities and differences of the commonly used methods. the use of least squares (LS), total least squares (TLS), double least squares (DLS) and singular value decomposition (SVD) methods is discussed in order to take advantage of redundant measurement data. Eigenvalue and SVD transformation methods are utilized to reduce the effective size of the resulting eigenvalue-eigenvector problem as well.
Towards a Unified Sentiment Lexicon Based on Graphics Processing Units
Directory of Open Access Journals (Sweden)
Liliana Ibeth Barbosa-Santillán
2014-01-01
Full Text Available This paper presents an approach to create what we have called a Unified Sentiment Lexicon (USL. This approach aims at aligning, unifying, and expanding the set of sentiment lexicons which are available on the web in order to increase their robustness of coverage. One problem related to the task of the automatic unification of different scores of sentiment lexicons is that there are multiple lexical entries for which the classification of positive, negative, or neutral {P,N,Z} depends on the unit of measurement used in the annotation methodology of the source sentiment lexicon. Our USL approach computes the unified strength of polarity of each lexical entry based on the Pearson correlation coefficient which measures how correlated lexical entries are with a value between 1 and −1, where 1 indicates that the lexical entries are perfectly correlated, 0 indicates no correlation, and −1 means they are perfectly inversely correlated and so is the UnifiedMetrics procedure for CPU and GPU, respectively. Another problem is the high processing time required for computing all the lexical entries in the unification task. Thus, the USL approach computes a subset of lexical entries in each of the 1344 GPU cores and uses parallel processing in order to unify 155802 lexical entries. The results of the analysis conducted using the USL approach show that the USL has 95.430 lexical entries, out of which there are 35.201 considered to be positive, 22.029 negative, and 38.200 neutral. Finally, the runtime was 10 minutes for 95.430 lexical entries; this allows a reduction of the time computing for the UnifiedMetrics by 3 times.
Dolan, James F.; Meade, Brendan J.
2017-12-01
Comparison of preevent geodetic and geologic rates in three large-magnitude (Mw = 7.6-7.9) strike-slip earthquakes reveals a wide range of behaviors. Specifically, geodetic rates of 26-28 mm/yr for the North Anatolian fault along the 1999 MW = 7.6 Izmit rupture are ˜40% faster than Holocene geologic rates. In contrast, geodetic rates of ˜6-8 mm/yr along the Denali fault prior to the 2002 MW = 7.9 Denali earthquake are only approximately half as fast as the latest Pleistocene-Holocene geologic rate of ˜12 mm/yr. In the third example where a sufficiently long pre-earthquake geodetic time series exists, the geodetic and geologic rates along the 2001 MW = 7.8 Kokoxili rupture on the Kunlun fault are approximately equal at ˜11 mm/yr. These results are not readily explicable with extant earthquake-cycle modeling, suggesting that they may instead be due to some combination of regional kinematic fault interactions, temporal variations in the strength of lithospheric-scale shear zones, and/or variations in local relative plate motion rate. Whatever the exact causes of these variable behaviors, these observations indicate that either the ratio of geodetic to geologic rates before an earthquake may not be diagnostic of the time to the next earthquake, as predicted by many rheologically based geodynamic models of earthquake-cycle behavior, or different behaviors characterize different fault systems in a manner that is not yet understood or predictable.
Basoglu, Burak; Halicioglu, Kerem; Albayrak, Muge; Ulug, Rasit; Tevfik Ozludemir, M.; Deniz, Rasim
2017-04-01
In the last decade, the importance of high-precise geoid determination at local or national level has been pointed out by Turkish National Geodesy Commission. The Commission has also put objective of modernization of national height system of Turkey to the agenda. Meanwhile several projects have been realized in recent years. In Istanbul city, a GNSS/Levelling geoid was defined in 2005 for the metropolitan area of the city with an accuracy of ±3.5cm. In order to achieve a better accuracy in this area, "Local Geoid Determination with Integration of GNSS/Levelling and Astro-Geodetic Data" project has been conducted in Istanbul Technical University and Bogazici University KOERI since January 2016. The project is funded by The Scientific and Technological Research Council of Turkey. With the scope of the project, modernization studies of Digital Zenith Camera System are being carried on in terms of hardware components and software development. Accentuated subjects are the star catalogues, and centroiding algorithm used to identify the stars on the zenithal star field. During the test observations of Digital Zenith Camera System performed between 2013-2016, final results were calculated using the PSF method for star centroiding, and the second USNO CCD Astrograph Catalogue (UCAC2) for the reference star positions. This study aims to investigate the position accuracy of the star images by comparing different centroiding algorithms and available star catalogs used in astro-geodetic observations conducted with the digital zenith camera system.
Directory of Open Access Journals (Sweden)
Dedi Atunggal
2018-06-01
Full Text Available GPS modules have been used for various applications in recent years. Its early development came in parallel with the advancement of Unmanned Aerial Vehicle (UAV technology. Nowadays, it is also used in in geographic information system (GIS data acquisition/census, mapping surveys, structure stability monitoring systems and many other applications. GPS modules generally have several positioning features, including standard positioning service (SPS, static positioning, precise point positioning (PPP, post processing kinematic (PPK and real time kinematic (RTK GPS. GPS modules in general are only equipped with a microstrip-type antenna or better known as patch antenna. Results from related research show that GPS module with this type of antenna has sub meter accuracy when used for PPK or RTK GPS method. The use of geodetic antennas is very potential to increase GPS position accuracy by up to centimeter level. This paper discusses the evaluation of GPS module measurements with geodetic type antennas for precise positioning using RTK GPS. This paper is focused on the resolution of GPS cycle ambiguity that is often expressed by the term fixing ratio and the accuracy of measurement results obtained. To provide a comprehensive description of the performance of GPS module, in this research two types of GPS module were used; single and dual frequency. Both types of GPS modules were used to conduct simultaneous observation on an open and obstructed observation location.
Design of output feedback controller for a unified chaotic system
International Nuclear Information System (INIS)
Li Wenlin; Chen Xiuqin; Shen Zhiping
2008-01-01
In this paper, the synchronization of a unified chaotic system is investigated by the use of output feedback controllers; a two-input single-output feedback controller and single-input single-output feedback controller are presented to synchronize the unified chaotic system when the states are not all measurable. Compared with the existing results, the controllers designed in this paper have some advantages such as small feedback gain, simple structure and less conservation. Finally, numerical simulations results are provided to demonstrate the validity and effectiveness of the proposed method
Nonlinear adaptive inverse control via the unified model neural network
Jeng, Jin-Tsong; Lee, Tsu-Tian
1999-03-01
In this paper, we propose a new nonlinear adaptive inverse control via a unified model neural network. In order to overcome nonsystematic design and long training time in nonlinear adaptive inverse control, we propose the approximate transformable technique to obtain a Chebyshev Polynomials Based Unified Model (CPBUM) neural network for the feedforward/recurrent neural networks. It turns out that the proposed method can use less training time to get an inverse model. Finally, we apply this proposed method to control magnetic bearing system. The experimental results show that the proposed nonlinear adaptive inverse control architecture provides a greater flexibility and better performance in controlling magnetic bearing systems.
Role of baryons in unified dark matter models
International Nuclear Information System (INIS)
Beca, L.M.G.; Avelino, P.P.; Carvalho, J.P. de M.; Martins, C.J.A.P.
2003-01-01
We discuss the importance of including baryons in analyses of unified dark matter scenarios, focusing on toy models involving a generalized Chaplygin gas. We determine observational constraints on this unified dark matter scenario coming from large-scale structure, type Ia supernovae and CMB data showing how this component can bring about a different behavior from the classical cold dark matter model with a cosmological constant and thus motivate further studies of this type of models. We also speculate on interesting new features which are likely to be important on nonlinear scales in this context
Geometric theory of fundamental interactions. Foundations of unified physics
International Nuclear Information System (INIS)
Pestov, A.B.
2012-01-01
We put forward an idea that regularities of unified physics are in a simple relation: everything in the concept of space and the concept of space in everything. With this hypothesis as a ground, a conceptual structure of a unified geometrical theory of fundamental interactions is created and deductive derivation of its main equations is produced. The formulated theory gives solution of the actual problems, provides opportunity to understand the origin and nature of physical fields, local internal symmetry, time, energy, spin, charge, confinement, dark energy and dark matter, thus conforming the existence of new physics in its unity
Besutiu, Lucian; Zlagnean, Luminita
2015-04-01
Background Located in the bending zone of East Carpathians, the so-called Vrancea zone is one of the most active seismic regions in Europe. Despite many years of international research, its intermediate-depth seismicity within full intra-continental environment still represents a challenge of the 21st century. Infrastructure In the attempt to join the above-mentioned efforts, the Solid Earth Dynamics Department (SEDD) in the Institute of Geodynamics of the Romanian Academy has developed a special research infrastructure, mainly devoted to gravity and space geodesy observations. A geodetic network covering the epicentre area of the intermediate-depth earthquakes has been designed and implemented for monitoring deep geodynamic processes and their surface echoes. Within each base-station of the above-mentioned network, a still-reinforced concrete pillar allows for high accuracy repeated gravity and GPS determinations. Results Starting from some results of the previously run CERGOP and UNIGRACE European programmes, to which additional SEDD repeated field campaigns were added, an unusual geodynamic behaviour has been revealed in the area. 1) Crust deformation: unlike the overall uprising of East Carpathians, as a result of denudation followed by erosion, their SE bending zone, with Vrancea epicentre area exhibits a slight subsidence. 2) Gravity change: more than 200 microgals non-tidal gravity decrease over a 20 years time-span has been noticed within the subsiding area. Extended observations showed the gravity lowering as a nowadays continuing process. Interpretation This strange combination of topography subsidence and gravity lowering has been interpreted in terms of crust stretching in the Vrancea epicentre zone due to the gravity pull created by densification of the lower crust as a result of phase-transform processes taking place in the lithospheric compartment sunken into the upper mantle. The occurrence of crust earthquakes with vertical-extension focal
Geodetic Imaging for Rapid Assessment of Earthquakes: Airborne Laser Scanning (ALS)
Carter, W. E.; Shrestha, R. L.; Glennie, C. L.; Sartori, M.; Fernandez-Diaz, J.; National CenterAirborne Laser Mapping Operational Center
2010-12-01
northwest, from the epicenter in Baja California through the US-Mexico border. The ALS observations were collected from an aircraft altitude of 600 m, flying at approximately 80 m/sec, using an Optech Inc. Gemini sensor, operating at 100 kHz, a scanning angle plus/minus 14 degrees and scan rate of 60 Hz. Some 24 lines, comprising a corridor 3 km wide and 106 km in length, were mapped, with a nominal point density of just over 10 points/m2. Total flight time for the project was just under 21 hours, but the laser on time was only 13 hours and 21 minutes. Preliminary versions of the observational data were delivered to the PIs (Michael Oskin, UC Davis, and Ramon Arrowsmith, ASU) within a few days of their collection. Geodetic imaging is still in its early stages of development, and ALS technology is progressing rapidly. The use of multiple channel (based on multiple lasers of the same or different colors and/or receivers operating in parallel) ALS units will result in contiguous sub-decimeter coverage, and deployment of ALS units in UAVs, with data transmitted to the operators in real time, will further reduce the turn-around time and enable more rapid assessment of earthquakes within the next decade.
Gualandi, Adriano; Serpelloni, Enrico; Elina Belardinelli, Maria; Bonafede, Maurizio; Pezzo, Giuseppe; Tolomei, Cristiano
2015-04-01
A critical point in the analysis of ground displacement time series, as those measured by modern space geodetic techniques (primarly continuous GPS/GNSS and InSAR) is the development of data driven methods that allow to discern and characterize the different sources that generate the observed displacements. A widely used multivariate statistical technique is the Principal Component Analysis (PCA), which allows to reduce the dimensionality of the data space maintaining most of the variance of the dataset explained. It reproduces the original data using a limited number of Principal Components, but it also shows some deficiencies, since PCA does not perform well in finding the solution to the so-called Blind Source Separation (BSS) problem. The recovering and separation of the different sources that generate the observed ground deformation is a fundamental task in order to provide a physical meaning to the possible different sources. PCA fails in the BSS problem since it looks for a new Euclidean space where the projected data are uncorrelated. Usually, the uncorrelation condition is not strong enough and it has been proven that the BSS problem can be tackled imposing on the components to be independent. The Independent Component Analysis (ICA) is, in fact, another popular technique adopted to approach this problem, and it can be used in all those fields where PCA is also applied. An ICA approach enables us to explain the displacement time series imposing a fewer number of constraints on the model, and to reveal anomalies in the data such as transient deformation signals. However, the independence condition is not easy to impose, and it is often necessary to introduce some approximations. To work around this problem, we use a variational bayesian ICA (vbICA) method, which models the probability density function (pdf) of each source signal using a mix of Gaussian distributions. This technique allows for more flexibility in the description of the pdf of the sources
Trembecka, Anna
2013-06-01
Amendment to the Act on special rules of preparation and implementation of investment in public roads resulted in an accelerated mode of acquisition of land for the development of roads. The decision to authorize the execution of road investment issued on its basis has several effects, i.e. determines the location of a road, approves surveying division, approves construction design and also results in acquisition of a real property by virtue of law by the State Treasury or local government unit, among others. The conducted study revealed that over 3 years, in this mode, the city of Krakow has acquired 31 hectares of land intended for the implementation of road investments. Compensation is determined in separate proceedings based on an appraisal study estimating property value, often at a distant time after the loss of land by the owner. One reason for the lengthy compensation proceedings is challenging the proposed amount of compensation, unregulated legal status of the property as well as imprecise legislation. It is important to properly develop geodetic and legal documentation which accompanies the application for issuance of the decision and is also used in compensation proceedings. Zmiana ustawy o szczególnych zasadach przygotowywania i realizacji inwestycji w zakresie dróg publicznych spowodowała przyspieszony tryb pozyskiwania gruntów przeznaczonych pod budowę dróg. Wydawana na jej podstawie decyzja o zezwoleniu na realizację inwestycji drogowej wywołuje szereg skutków, tj. m.in. ustala lokalizację drogi, zatwierdza podziały geodezyjne, zatwierdza projekt budowlany a także powoduje nabycie nieruchomości z mocy prawa, przez Skarb Państwa lub jednostki samorządu terytorialnego. Przeprowadzone badania wykazały iż w powyższym trybie miasto Kraków nabyło w okresie 3 lat ponad 31 ha gruntów przeznaczonych na realizację inwestycji drogowych. Odszkodowanie ustalane jest w drodze odrębnego postępowania w oparciu o operat szacunkowy okre
Sudhaus, Henriette; Heimann, Sebastian; Steinberg, Andreas; Isken, Marius; Vasyura-Bathke, Hannes
2017-04-01
In the last few years impressive achievements have been made in improving inferences about earthquake sources by using InSAR (Interferometric Synthetic Aperture Radar) data. Several factors aided these developments. The open data basis of earthquake observations has expanded vastly with the two powerful Sentinel-1 SAR sensors up in space. Increasing computer power allows processing of large data sets for more detailed source models. Moreover, data inversion approaches for earthquake source inferences are becoming more advanced. By now data error propagation is widely implemented and the estimation of model uncertainties is a regular feature of reported optimum earthquake source models. Also, more regularly InSAR-derived surface displacements and seismological waveforms are combined, which requires finite rupture models instead of point-source approximations and layered medium models instead of homogeneous half-spaces. In other words the disciplinary differences in geodetic and seismological earthquake source modelling shrink towards common source-medium descriptions and a source near-field/far-field data point of view. We explore and facilitate the combination of InSAR-derived near-field static surface displacement maps and dynamic far-field seismological waveform data for global earthquake source inferences. We join in the community efforts with the particular goal to improve crustal earthquake source inferences in generally not well instrumented areas, where often only the global backbone observations of earthquakes are available provided by seismological broadband sensor networks and, since recently, by Sentinel-1 SAR acquisitions. We present our work on modelling standards for the combination of static and dynamic surface displacements in the source's near-field and far-field, e.g. on data and prediction error estimations as well as model uncertainty estimation. Rectangular dislocations and moment-tensor point sources are exchanged by simple planar finite
Phase transitions at finite chemical potential in grand unified theories
International Nuclear Information System (INIS)
Bailin, D.; Love, A.
1984-01-01
We discuss the circumstances in which non-zero chemical potentials might prevent symmetry restoration in phase transitions in the early universe at grand unification or partial unification scales. The general arguments are illustrated by consideration of SO(10) and SU(5) grand unified theories. (orig.)
About the Possibility of Creation of a Deterministic Unified Mechanics
International Nuclear Information System (INIS)
Khomyakov, G.K.
2005-01-01
The possibility of creation of a unified deterministic scheme of classical and quantum mechanics, allowing to preserve their achievements is discussed. It is shown that the canonical system of ordinary differential equation of Hamilton classical mechanics can be added with the vector system of ordinary differential equation for the variables of equations. The interpretational problems of quantum mechanics are considered
Designing a framework for a unified electronic identity system ...
African Journals Online (AJOL)
In this paper, a Unified Identity System is proposed where single electronic identity (eID) is issued that can be used across the various platforms of business transaction. The activity/state diagram of the model is presented, and the means of authentication is based on the Secure Assertion Markup Language (SAML) ...
A unifying approach to existence of Nash equilibria
Balder, E.J.
1997-01-01
An approach initiated in [4] is shown to unify results about the existence of (i) Nash equilibria in games with at most countably many players, (ii) Cournot-Nash equilibrium distributions for large, anonymous games, and (iii) Nash equilibria (both mixed and pure) for continuum games. A new, central
Seismic monitoring: a unified system for research and verifications
International Nuclear Information System (INIS)
Thigpen, L.
1979-01-01
A system for characterizing either a seismic source or geologic media from observational data was developed. This resulted from an examination of the forward and inverse problems of seismology. The system integrates many seismic monitoring research efforts into a single computational capability. Its main advantage is that it unifies computational and research efforts in seismic monitoring. 173 references, 9 figures, 3 tables
Unified Model for Generation Complex Networks with Utility Preferential Attachment
International Nuclear Information System (INIS)
Wu Jianjun; Gao Ziyou; Sun Huijun
2006-01-01
In this paper, based on the utility preferential attachment, we propose a new unified model to generate different network topologies such as scale-free, small-world and random networks. Moreover, a new network structure named super scale network is found, which has monopoly characteristic in our simulation experiments. Finally, the characteristics of this new network are given.
Adapting the unified software development process for user interface development
Obrenovic, Z.; Starcevic, D.
2006-01-01
In this paper we describe how existing software developing processes, such as Rational Unified Process, can be adapted in order to allow disciplined and more efficient development of user interfaces. The main objective of this paper is to demonstrate that standard modeling environments, based on the
Designing synchronization schemes for chaotic fractional-order unified systems
International Nuclear Information System (INIS)
Wang Junwei; Zhang Yanbin
2006-01-01
Synchronization in chaotic fractional-order differential systems is studied both theoretically and numerically. Two schemes are designed to achieve chaos synchronization of so-called unified chaotic systems and the corresponding numerical algorithms are established. Some sufficient conditions on synchronization are also derived based on the Laplace transformation theory. Computer simulations are used for demonstration
Modeling of hydrodynamic cavitation reactors: a unified approach
Moholkar, V.S.; Pandit, A.B.
2001-01-01
An attempt has been made to present a unified theoretical model for the cavitating flow in a hydrodynamic cavitation reactor using the nonlinear continuum mixture model for two-phase flow as the basis. This model has been used to describe the radial motion of bubble in the cavitating flow in two
The Bjorken-Paschos relation in the unified gauge theory
International Nuclear Information System (INIS)
Oh, S.K.
1980-07-01
We have examined in the unified gauge theory with the integrally-charged quark model the Bjorken-Paschos relation within the impulse approximation of the parton picture. We find that the relation is valid for the forward scattering region and provides a reliable way to test the charge assignment of the quarks and the gluons. (author)
Catastrophe Theory: A Unified Model for Educational Change.
Cryer, Patricia; Elton, Lewis
1990-01-01
Catastrophe Theory and Herzberg's theory of motivation at work was used to create a model of change that unifies and extends Lewin's two separate stage and force field models. This new model is used to analyze the behavior of academics as they adapt to the changing university environment. (Author/MLW)
78 FR 18235 - Unified Rule for Loss on Subsidiary Stock
2013-03-26
... DEPARTMENT OF THE TREASURY Internal Revenue Service 26 CFR Part 1 Unified Rule for Loss on... first sentence, reinstate the following sentence: Sec. 1.1502-32 Investment adjustments. * * * * * (c... than the time the distribution is taken into account under the Internal Revenue Code (e.g., under...
Teachers' Perceptions of Technology Integration in a Unified School District
Bloodman, Suzette L.
2014-01-01
A unified school district (USD) continues to invest millions of dollars into its technology integration initiatives with minimal academic gains. Since teachers are essential to effective technology integration, the purpose of this phenomenological study was to analyze the perceptions of 13 teachers within the USD relative to how they could more…
New unified field theory based on the conformal group
Energy Technology Data Exchange (ETDEWEB)
Pessa, E [Rome Univ. (Italy). Ist. di Matematica
1980-10-01
Based on a six-dimensional generalization of Maxwell's equations, a new unified theory of the electromagnetic and gravitational field is developed. Additional space-time coordinates are interpreted only as mathematical tools in order to obtain a linear realization of the four-dimensional conformal group.
When Unified Teacher Pay Scales Meet Differential Alternative Returns
Walsh, Patrick
2014-01-01
This paper quantifies the extent to which unified teacher pay scales and differential alternatives produce opportunity costs that are asymmetric in math and verbal skills. Data from the Baccalaureate and Beyond 1997 and 2003 follow-ups are used to estimate a fully parametric, selection-corrected wage equation for nonteachers, which is then used to…
Quintessential inflation: A unified scenario of inflation and dark energy
Directory of Open Access Journals (Sweden)
Hossain Wali
2018-01-01
Full Text Available Quintessential inflation unifies inflation and late time acceleration by a single scalar field. Such a scenario, with canonical and non-canonical scalar fields, has been discussed. The scalar field behaves as an inflaton field during inflation and as a quintessence field during late time. Also the predictions of the models has been compared with the recent Planck data.
A unifying theory The universe on a string
Greene, Brian
2006-01-01
Seventy-five years ago, Albert Einstein completed his unified field theory; but, as had happened before and would happen again, Einstein had to go bak to the drawing board. Much progress have been inspired, with the most recent advances coming from an approach called string theory. (1,5 page)
Unified Approach to Universal Cloning and Phase-Covariant Cloning
Hu, Jia-Zhong; Yu, Zong-Wen; Wang, Xiang-Bin
2008-01-01
We analyze the problem of approximate quantum cloning when the quantum state is between two latitudes on the Bloch's sphere. We present an analytical formula for the optimized 1-to-2 cloning. The formula unifies the universal quantum cloning (UQCM) and the phase covariant quantum cloning.
Towards a unified theory of task-specific motivation
De Brabander, Cornelis; Martens, Rob
2014-01-01
This study aims to integrate the current proliferation of motivation theories in a Unified Model of Task-specific Motivation (UMTM). According to this model readiness for action results from an interaction between four relatively independent types of valences that can be classified as affective or
The Vector Space as a Unifying Concept in School Mathematics.
Riggle, Timothy Andrew
The purpose of this study was to show how the concept of vector space can serve as a unifying thread for mathematics programs--elementary school to pre-calculus college level mathematics. Indicated are a number of opportunities to demonstrate how emphasis upon the vector space structure can enhance the organization of the mathematics curriculum.…
Unifying weak and electromagnetic forces in Weinberg-Salam theory
International Nuclear Information System (INIS)
Savoy, C.A.
1978-01-01
In this introduction to the ideas related to the unified gauge theories of the weak and electromagnetic interactions, we begin with the motivations for its basic principles. Then, the formalism is briefly developed, in particular the so-called Higgs mechanism. The advantages and the consequences of the (non-abelian) gauge invariance are emphasized, together with the experimental tests of the theory [fr
Masses of particles in the SO(18) grand unified model
International Nuclear Information System (INIS)
Asatryan, G.M.
1984-01-01
The grand unified model based on the orthogonal group SO(18) is treated. The model involves four familiar and four mirror families of fermions. Arising of masses of familiar and mirror particles is studied. The mass of the right-handed Wsub(R) boson interacting via right-handed current way is estimated
The coherence problem with th Unified Neutral Theory of biodiversity
James S. Clark
2012-01-01
The Unified Neutral Theory of Biodiversity (UNTB), proposed as an alternative to niche theory, has been viewed as a theory that species coexist without niche differences, without fitness differences, or with equal probability of success. Support is claimed when models lacking species differences predict highly aggregated metrics, such as species abundance distributions...
Unifying the Universe the physics of heaven and earth
Padamsee, Hasan S
2003-01-01
Unifying the Universe: The Physics of Heaven and Earth provides a solid background in basic physics. With a humanistic perspective, it shows how science is significant for more than its technological consequences. The book includes clear and well-planned links to the arts and philosophies of relevant historical periods to bring science and the humanities together.
Schr"odinger's Unified Field Theory: Physics by Public Relations
Halpern, Paul
2009-05-01
We will explore the circumstances surrounding Erwin Schr"odinger's announcement in January 1947 that he had developed a comprehensive unified field theory of gravitation and electromagnetism. We will speculate on Schr"odinger's motivations for the mode and tone of his statements, consider the reaction of the international press within the context of the postwar era, and examine Einstein's response.
A Unified Analysis of Japanese Aspect Marker "te iru."
Shinzato, Rumiko
1993-01-01
Following Jacobson's 1990 work, this study is another attempt to offer a unified analysis of the Japanese aspect marker "te iru" that touches upon Gestalt psychologists' ideas of figure/ground opposition, Langacker's cognitive grammar, and Kunihiro's cognitive analysis. (Contains 34 references.) (LB)
2011-01-31
... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of the... protection, Air pollution control, Incorporation by reference, Intergovernmental relations, Nitrogen dioxide...
2011-08-23
... respiratory and cardiovascular disease, decreased lung function, visibility impairment, and damage to... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... approve revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of...
2010-05-21
..., aggravation of respiratory and cardiovascular disease, decreased lung function, visibility impairment, and... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... approve revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of...
2011-06-24
... premature mortality, aggravation of respiratory and cardiovascular disease, decreased lung function... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... approve revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of...
Pratt-Sitaula, B. A.; Walker, B.; Douglas, B. J.; Charlevoix, D. J.; Miller, M. M.
2015-12-01
The GETSI project, funded by NSF TUES, is developing and disseminating teaching and learning materials that feature geodesy data applied to critical societal issues such as climate change, water resource management, and natural hazards (serc.carleton.edu/getsi). It is collaborative between UNAVCO (NSF's geodetic facility), Mt San Antonio College, and Indiana University. GETSI was initiated after requests by geoscience faculty for geodetic teaching resources for introductory and majors-level students. Full modules take two weeks but module subsets can also be used. Modules are developed and tested by two co-authors and also tested in a third classroom. GETSI is working in partnership with the Science Education Resource Center's (SERC) InTeGrate project on the development, assessment, and dissemination to ensure compatibility with the growing number of resources for geoscience education. Two GETSI modules are being published in October 2015. "Ice mass and sea level changes" includes geodetic data from GRACE, satellite altimetry, and GPS time series. "Imaging Active Tectonics" has students analyzing InSAR and LiDAR data to assess infrastructure earthquake vulnerability. Another three modules are in testing during fall 2015 and will be published in 2016. "Surface process hazards" investigates mass wasting hazard and risk using LiDAR data. "Water resources and geodesy" uses GRACE, vertical GPS, and reflection GPS data to have students investigating droughts in California and the High Great Plains. "GPS, strain, and earthquakes" helps students learn about infinitesimal and coseismic strain through analysis of horizontal GPS data and includes an extension module on the Napa 2014 earthquake. In addition to teaching resources, the GETSI project is compiling recommendations on successful development of geodesy curricula. The chief recommendations so far are the critical importance of including scientific experts in the authorship team and investing significant resources in
Wang, K.; Sun, T.; Hino, R.; Iinuma, T.; Tomita, F.; Kido, M.
2017-12-01
Numerous observations pertaining to the M=9.0 2011 Tohoku-oki earthquake have led to new understanding of subduction zone earthquakes. By synthesizing published research results and our own findings, we explore what has been learned about fault behavior and Earth rheology from geodetic imaging of crustal deformation before and after the earthquake. Before the earthquake, megathrust locking models based on land-based geodetic observations correctly outlined the along-strike location of the future rupture zone, showing that land-based observations are capable of resolving along-strike variations in locking and creep at wavelengths comparable to distances from the network. But they predicted a locked zone that was much deeper than the actual rupture in 2011. The incorrect definition of the locking pattern in the dip direction demonstrates not only the need for seafloor geodesy but also the importance of modeling interseismic viscoelastic stress relaxation and stress shadowing. The discovery of decade-long accelerated slip downdip of the future rupture zone raises new questions on fault mechanics. After the earthquake, seafloor geodetic discovery of opposing motion offshore provided unambiguous evidence for the dominance of viscoelastic relaxation in short-term postseismic deformation. There is little deep afterslip in the fault area where the decade-long pre-earthquake slip acceleration is observed. The complementary spatial distribution of pre-slip and afterslip calls for new scientific research. However, the near absence of deep afterslip directly downdip of the main rupture is perceived to be controversial because some viscoelastic models do predict large afterslip here, although less than predicted by purely elastic models. We show that the large afterslip in these models is largely an artefact due to the use of a layered Earth model without a subducting slab. The slab acts as an "anchor" in the mantle and retards landward motion following a subduction earthquake
Bos, A.G. (Annemarie Gerredina)
2003-01-01
In this thesis I am concerned with modeling the kinematics of surface deformation using space geodetic observations in order to advance insight in both interseismic and coseismic surface response. To model the surface deformation field I adopt the method of Spakman and Nyst (2002) which resolves the
Synchronization of a unified chaotic system and the application in secure communication
International Nuclear Information System (INIS)
Lu Junan; Wu Xiaoqun; Lue Jinhu
2002-01-01
This Letter further investigates the synchronization of a unified chaotic system via different methods. Several sufficient theorems for the synchronization of the unified chaotic system are deduced. A scheme of secure communication based on the synchronization of the unified chaotic system is presented. Numerical simulation shows its feasibility
Performance Analysis of FSO Links over Unified Gamma-Gamma Turbulence Channels
Ansari, Imran Shafique; Yilmaz, Ferkan; Alouini, Mohamed-Slim
2015-01-01
, then, present unified exact closed-form expressions for various statistical characteristics of the end-to-end signal-to-noise ratio (SNR) of a single link FSO transmission system. We capitalize on these unified results to offer unified exact closed
2011-07-28
... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... proposing to approve San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) Rule 3170... the environment. San Joaquin Valley Unified Air Pollution Control District SJVUAPCD is an extreme...
Directory of Open Access Journals (Sweden)
Panou G.
2017-02-01
Full Text Available The direct geodesic problem on an oblate spheroid is described as an initial value problem and is solved numerically using both geodetic and Cartesian coordinates. The geodesic equations are formulated by means of the theory of differential geometry. The initial value problem under consideration is reduced to a system of first-order ordinary differential equations, which is solved using a numerical method. The solution provides the coordinates and the azimuths at any point along the geodesic. The Clairaut constant is not used for the solution but it is computed, allowing to check the precision of the method. An extensive data set of geodesics is used, in order to evaluate the performance of the method in each coordinate system. The results for the direct geodesic problem are validated by comparison to Karney’s method. We conclude that a complete, stable, precise, accurate and fast solution of the problem in Cartesian coordinates is accomplished.
Hamiel, Yariv; Piatibratova, Oksana; Mizrahi, Yaakov; Nahmias, Yoav; Sagy, Amir
2018-04-01
Detailed field and geodetic observations of crustal deformation across the Jericho Fault section of the Dead Sea Fault are presented. New field observations reveal several slip episodes that rupture the surface, consist with strike slip and extensional deformation along a fault zone width of about 200 m. Using dense Global Positioning System measurements, we obtain the velocities of new stations across the fault. We find that this section is locked for strike-slip motion with a locking depth of 16.6 ± 7.8 km and a slip rate of 4.8 ± 0.7 mm/year. The Global Positioning System measurements also indicate asymmetrical extension at shallow depths of the Jericho Fault section, between 0.3 and 3 km. Finally, our results suggest the vast majority of the sinistral slip along the Dead Sea Fault in southern Jorden Valley is accommodated by the Jericho Fault section.
Varugu, B. K.; Amelung, F.
2017-12-01
Mauna Loa volcano, located on the Big Island, Hawaii, is the largest volcano on the earth and historically been one of the most active volcanoes on the earth. Since its last eruption in 1984, there was a decrease in the magmatic activity, yet episodic inflations with increased seismicity sparks interests in the scientific community and there is strong need to monitor the volcano with growing infrastructure close to the flanks of the volcano. Geodetic modelling of the previous inflations illustrate that the magma activity is due to inflation of hydraulically connected dike and magma chamber located from 4-8km beneath the summit (Amelung et al. 2007). Most of the seismicity observed on Mauna Loa is due to the movement along a decollement fault situated at the base of the volcano. Magma inflation under Mauna Loa has started again during the last quarter of 2013 and is continuing still with an increased seismicity. In this study, we used 140 images form COSMO SkyMED between 2013-2017 to derive and model the ground deformation. We carried out time series InSAR analysis using Small Baseline (SB) approach. While the deformation pattern seems similar in many ways to the previous inflation periods, geodetic modelling for inversion of source parameters indicate a significant propagation of the dike ( 1 km) into the South West Rift Zone(SWRZ) and a decreased depth of the dike top from summit, compared to the previous inflations. Such propagation needs to be studied further in view of the steep slope of SWRZ. In understanding the dynamics of this propagating dike, we also observed an increased seismic activity since 2014 in the vicinity of the modelled dike. Here in this study we attempt to characterize the stresses induced by the propagating dike and seaward slipping movement along the basal decollement, to explain the increased seismicity using a finite element model.
How Well do we Know Near-Surface Density When Determining Mass Balance by the Geodetic Method?
Kuhn, M. H.; Matzi, E.
2005-12-01
From a data set of firn pits in the accumulation area of Hintereisferner in the years 1964 - 2002 the behavior of density and water equivalent was analyzed with a view to estimating the potential errors in the application of the geodetic method. Since annual specific balance ranged from 100 to 3300 mm w.e. the profiles were scaled to total depth. For the uppermost 10% of the annual deposit at a typical location the 1964-2002 mean density would be 350 kg/m-3 with a standard deviation of 110 kg/m-3; for the 10% layer at the base of the annual snowpack the respective figures are 510 +- 30 kg/m-3. The normalized long term means of an ensemble of 9 pits ranged from 310 to 380 kg/m-3 in the top layer and from 510 to 540 kg/m-3 in the bottom layer. When one outlier is removed the the range in the bottom layer reduces to 525 to 540 kg/m-3. This small local variance encourages the use of the geodetic method. The comparison of elevation models of 1969 and 1997 yields a mass change that agrees very well with the results of the glaciological method provided the volume change is converted to mass with a density of 900 kg/m-3. While this may be true for the entire glacier on long terms, it will fail for individual years in the accumulation area. Possible errors are calculated from the data set emphasizing the role of year to year changes of specific balance and accumulation area ratio.
The Unified Database for BM@N experiment data handling
Gertsenberger, Konstantin; Rogachevsky, Oleg
2018-04-01
The article describes the developed Unified Database designed as a comprehensive relational data storage for the BM@N experiment at the Joint Institute for Nuclear Research in Dubna. The BM@N experiment, which is one of the main elements of the first stage of the NICA project, is a fixed target experiment at extracted Nuclotron beams of the Laboratory of High Energy Physics (LHEP JINR). The structure and purposes of the BM@N setup are briefly presented. The article considers the scheme of the Unified Database, its attributes and implemented features in detail. The use of the developed BM@N database provides correct multi-user access to actual information of the experiment for data processing. It stores information on the experiment runs, detectors and their geometries, different configuration, calibration and algorithm parameters used in offline data processing. An important part of any database - user interfaces are presented.
Rational Unified Process jako metodika vývoje softwaru
Rytíř, Vladimír
2008-01-01
Cílem této práce je seznámit se s procesem vývoje softwaru dle vybraných metodik s hlavním zaměřením na metodiku Rational Unified Process od firmy IBM. Incepční a elaborační fáze této metody také aplikuji na praktickém příkladě. Goal of my work is to introduce software development process metods specialized to Rational Unified Process metod from IBM. I aplicate inception and elaboration phases of RUP on practical example. B
Hyperion technology enables unified meteorological and radiological monitoring
International Nuclear Information System (INIS)
Zigic, A.; Saponjic, D.; Arandjelovic, V.; Zunic, Z. . E-mail address of corresponding author: alex@vin.bg.ac.yu; Zigic, A.)
2005-01-01
The present state of meteorological and radiological measurement and monitoring are quite localized to smaller areas which implies the difficulties in knowing the measurement results in the wider region instantly. The need for establishing a distributed, flexible, modular and centralized measurement system for both meteorological and radiological parameters of environment is arising. The measurement and monitoring of radiological parameters of environment are not sufficient since there is a strong correlation between radiological and meteorological parameters which implies a unified distributed automatic monitoring system. The unified monitoring system makes it possible to transfer, process and store measured data in local and central databases. Central database gives a possibility of easy access to all measured data for authorized personnel and institutions. Stored measured data in central database gives a new opportunity to create a base for meteorological and radiological modelling and studies. (author)
Transcultural nursing as a global care humanizer, diversifier, and unifier.
Leininger, M M
1997-01-01
Three dominant themes of transcultural nursing as a global humanizer, diversifier, and unifier are discussed in relation to their meaning and uses in education, practice, research and consultation. The presenter takes the position that these three dominant themes are essential and imperative to promote, transform, and maintain desired care outcomes which are beneficial, satisfying, and healthy for people of diverse and similar cultures. The three themes are discussed within Leininger's theory of Culture Care Diversity and Universality with focus on the modes of action and decision-making. The author encourages transcultural nurses to take leadership to be an active global humanizer, diversifier, and unifier and transform nursing and health care into the 21st century.
Unified dark fluid in Brans-Dicke theory
International Nuclear Information System (INIS)
Tripathy, Sunil K.; Behera, Dipanjali; Mishra, Bivudutta
2015-01-01
Anisotropic dark energy cosmological models are constructed in the frame work of generalised Brans-Dicke theory with a self-interacting potential. A unified dark fluid characterised by a linear equation of state is considered as the source of dark energy. The shear scalar is considered to be proportional to the expansion scalar simulating an anisotropic relationship among the directional expansion rates. The dynamics of the universe in the presence of a unified dark fluid in anisotropic background have been discussed. The presence of an evolving scalar field makes it possible to get an accelerating phase of expansion even for a linear relationship among the directional Hubble rates. It is found that the anisotropy in expansion rates does not affect the scalar field, the self-interacting potential, but it controls the non-evolving part of the Brans-Dicke parameter. (orig.)
Research and Design in Unified Coding Architecture for Smart Grids
Directory of Open Access Journals (Sweden)
Gang Han
2013-09-01
Full Text Available Standardized and sharing information platform is the foundation of the Smart Grids. In order to improve the dispatching center information integration of the power grids and achieve efficient data exchange, sharing and interoperability, a unified coding architecture is proposed. The architecture includes coding management layer, coding generation layer, information models layer and application system layer. Hierarchical design makes the whole coding architecture to adapt to different application environments, different interfaces, loosely coupled requirements, which can realize the integration model management function of the power grids. The life cycle and evaluation method of survival of unified coding architecture is proposed. It can ensure the stability and availability of the coding architecture. Finally, the development direction of coding technology of the Smart Grids in future is prospected.
A unified treatment of kinetic effects in a tokamak pedestal
International Nuclear Information System (INIS)
Catto, Peter J; Landreman, Matt; Kagan, Grigory; Pusztai, Istvan
2011-01-01
We consider the effects of a finite pedestal radial electric field on ion orbits using a unified approach. We then employ these modified orbit results to retain finite E x B drift departures from flux surfaces in an improved drift-kinetic equation. The procedure allows us to make a clear distinction between transit averages and flux surface averages when solving this kinetic equation. The technique outlined here is intended to clarify and unify recent evaluations of the banana regime decrease and plateau regime alterations in the ion heat diffusivity; the reduction and possible reversal of the poloidal flow in the banana regime, and its augmentation in the plateau regime; the increase in the bootstrap current; and the enhancement of the residual zonal flow regulation of turbulence.
Onset of the nonlinear regime in unified dark matter models
International Nuclear Information System (INIS)
Avelino, P.P.; Beca, L.M.G.; Carvalho, J.P.M. de; Martins, C.J.A.P.; Copeland, E.J.
2004-01-01
We discuss the onset of the nonlinear regime in the context of unified dark matter models involving a generalized Chaplygin gas. We show that the transition from dark-matter-like to dark-energy-like behavior will never be smooth. In some regions of space the transition will never take place while in others it may happen sooner or later than naively expected. As a result the linear theory used in previous studies may break down late in the matter dominated era even on large cosmological scales. We study the importance of this effect showing that its magnitude depends on the exact form of the equation of state in the low density regime. We expect that our results will be relevant for other unified dark matter scenarios, particularly those where the quartessence candidate is a perfect fluid
High energy behaviour of particles and unified statistics
International Nuclear Information System (INIS)
Chang, Y.
1984-01-01
Theories and experiments suggest that particles at high energy appear to possess a new statistics unifying Bose-Einstein and Fermi-Dirac statistics via the GAMMA distribution. This hypothesis can be obtained from many models, and agrees quantitatively with scaling, the multiplicty, large transverse momentum, the mass spectrum, and other data. It may be applied to scatterings at high energy, and agrees with experiments and known QED's results. The Veneziano model and other theories have implied new statistics, such as, the B distribution and the Polya distribution. They revert to the GAMMA distribution at high energy. The possible inapplicability of Pauli's exclusion principle within the unified statistics is considered and associated to the quark constituents
Reduction of parameters in Finite Unified Theories and the MSSM
Heinemeyer, Sven; Mondragón, Myriam; Tracas, Nicholas; Zoupanos, George
2018-02-01
The method of reduction of couplings developed by W. Zimmermann, combined with supersymmetry, can lead to realistic quantum field theories, where the gauge and Yukawa sectors are related. It is the basis to find all-loop Finite Unified Theories, where the β-function vanishes to all-loops in perturbation theory. It can also be applied to the Minimal Supersymmetric Standard Model, leading to a drastic reduction in the number of parameters. Both Finite Unified Theories and the reduced MSSM lead to successful predictions for the masses of the third generation of quarks and the Higgs boson, and also predict a heavy supersymmetric spectrum, consistent with the non-observation of supersymmetry so far.
Low-energy neutral current phenomenology and grand unified theories
International Nuclear Information System (INIS)
Del Aguila, F.; Mendez, A.
1981-01-01
We derive necessary and sufficient conditions to be satisfied by any expanded electroweak gauge model in order to reproduce the standard model low-energy neutral current predictions. These conditions imply several constraints on the neutral gauge boson masses and the quantum number assignments for the ordinary fermions. Using these conditions, we prove that the popular grand unified theories based on the gauge groups SO(10) and E6 can only accommodate trivial extensions of the standard model. As a consequence, if any of these grand unified models works at some energy scale, present low-energy neutral current phenomenology implies that the Z-boson must be produced with the expected mass and couplings to the ordinary fermions. Any additional neutral gauge boson (with the possible exception of very heavy ones) could only be produced in hadronic collisions and it would not decay in e + e - . (orig.)
Constructal Law and the Unifying Principle of Design
Lorente, Sylvie; Bejan, Adrian
2013-01-01
Design happens everywhere, whether in animate objects (e.g., dendritic lung structures, bacterial colonies, and corals), inanimate patterns (river basins, beach slope, and dendritic crystals), social dynamics (pedestrian traffic flows), or engineered systems (heat dissipation in electronic circuitry). This “design in nature” often takes on remarkably similar patterns, which can be explained under one unifying Constructal Law. This book explores the unifying power of the Constructal Law and its applications in all domains of design generation and evolution, ranging from biology and geophysics to globalization, energy, sustainability, and security. The Constructal Law accounts for the universal tendency of flow systems to morph into evolving configurations that provide greater and easier access over time. The Constructal Law resolves the many and contradictory ad hoc statements of “optimality”, end design, and destiny in nature, such as minimum and maximum entropy production and minimum and maximum fl...
Unified Digital Periodic Signal Filters for Power Converter Systems
DEFF Research Database (Denmark)
Yang, Yongheng; Xin, Zhen; Zhou, Keliang
2017-01-01
Periodic signal controllers like repetitive and resonant controllers have demonstrated much potential in the control of power electronic converters, where periodic signals (e.g., ac voltages and currents) can be precisely regulated to follow references. Beyond the control of periodic signals, ac...... signal processing (e.g., in synchronization and pre-filtering) is also very important for power converter systems. Hence, this paper serves to unify digital periodic signal filters so as to maximize their roles in power converter systems (e.g., enhance the control of ac signals). The unified digital...... periodic signal filters behave like a comb filter, but it can also be configured to selectively filter out the harmonics of interest (e.g., the odd-order harmonics in single-phase power converter systems). Moreover, a virtual variable-sampling-frequency unit delay that enables frequency adaptive periodic...
Modeling Enterprise Authorization: A Unified Metamodel and Initial Validation
Directory of Open Access Journals (Sweden)
Matus Korman
2016-07-01
Full Text Available Authorization and its enforcement, access control, have stood at the beginning of the art and science of information security, and remain being crucial pillar of security in the information technology (IT and enterprises operations. Dozens of different models of access control have been proposed. Although Enterprise Architecture as the discipline strives to support the management of IT, support for modeling access policies in enterprises is often lacking, both in terms of supporting the variety of individual models of access control nowadays used, and in terms of providing a unified ontology capable of flexibly expressing access policies for all or the most of the models. This study summarizes a number of existing models of access control, proposes a unified metamodel mapped to ArchiMate, and illustrates its use on a selection of example scenarios and two business cases.
DiPS: A Unifying Approach for developing System Software
Michiels, Sam; Matthijs, Frank; Walravens, Dirk; Verbaeten, Pierre
2002-01-01
In this paper we unify three essential features for flexible system software: a component oriented approach, self-adaptation and separation of concerns.We propose DiPS (Distrinet Protocol Stack), a component framework, which offers components, an anonymous interaction model and connectors to handle non-functional aspects such as concurrency. DiPS has effectively been used in industrial protocol stacks and device drivers.
Skinner-Rusk unified formalism for higher-order systems
Prieto-Martínez, Pedro Daniel; Román-Roy, Narciso
2012-07-01
The Lagrangian-Hamiltonian unified formalism of R. Skinner and R. Rusk was originally stated for autonomous dynamical systems in classical mechanics. It has been generalized for non-autonomous first-order mechanical systems, first-order and higher-order field theories, and higher-order autonomous systems. In this work we present a generalization of this formalism for higher-order non-autonomous mechanical systems.
Flavor unifying schemes with a single fermionic representation
International Nuclear Information System (INIS)
Davidson, A.; Wali, K.C.
1980-05-01
If quarks and leptons are indeed elementary, it is natural that they belong to a single representation of a unifying group, G. It is shown that such a requirement, which is inconsistent with G = SU(N), can be satisfied within the semi-simple group G = SU(N) x SU(N). Furthermore, N = 7 emerges as the unique solution accompanied by a fermionic set that exhibits a natural generation structure
Multiple growth regimes: Insights from unified growth theory
Galor, Oded
2007-01-01
Unified Growth Theory uncovers the forces that contributed to the existence of multiple growth regimes and the emergence of convergence clubs. It suggests that differential timing of take-offs from stagnation to growth segmented economies into three fundamental regimes: slow growing economies in a Malthusian regime, fast growing countries in a sustained growth regime, and economies in the transition between these regimes. In contrast to existing research that links regime switching thresholds...
A Unified Access Model for Interconnecting Heterogeneous Wireless Networks
2015-05-01
validation of the proposed network design for unified network access, and it lays the foundation for implementing a Software - Defined Networking ( SDN ...York (NY): Springer; 2014. Chapter 2, Software - defined networking ; p. 19–32. 5. Sharma S, Staessens D, Colle D, Pickavet M, Demeester P. A...demonstration of fast failure recovery in software defined networking . In: Korakis T, Zink M, Ott, M, editors. Testbeds and research infrastructure
The Unified Problem-Solving Method Development Language UPML
Fensel, Dieter; Motta, Enrico; van Harmelen, Frank; Benjamins, V. Richard; Crubezy, Monica; Decker, Stefan; Gaspari, Mauro; Groenboom, Rix; Grosso, William; Musen, Mark; Plaza, Enric; Schreiber, Guus; Studer, Rudi; Wielinga, Bob
2003-01-01
Problem-solving methods provide reusable architectures and components for implementing the reasoning part of knowledge-based systems. The UNIFIED PROBLEM-SOLVING METHOD DESCRIPTION LANGUAGE (UPML) has been developed to describe and implement such architectures and components to facilitate their semi-automatic reuse and adaptation. In a nutshell, UPML is a framework for developing knowledge-intensive reasoning systems based on libraries ofg eneric problem-solving components. The paper describe...
Split Octonion electrodynamics and unified fields of dyons
International Nuclear Information System (INIS)
Bisht, P.S.
2004-01-01
Split octonion electrodynamics has been developed in terms of Zorn's vector matrix realization by reformulating electromagnetic potential, current, field tensor and other dynamical quantities. Corresponding field equation (Unified Maxwell's equations) and equation of motion have been reformulated by means of split octonion and its Zorn vector realization in unique, simpler and consistent manner. It has been shown that this theory reproduces the dyon field equations in the absence of gravito-dyons and vice versa
Unified Facilities Criteria (UFC) Design Guide. Army Reserve Facilities
2010-02-01
horticulturally appropriate to the site specific location in which they are planted. Consideration should be given to adjacent structures and improvements...impact FPI Federal Prison Industries FPM Feet per minute GFCI Government-furnished/contractor-installed or Ground-Fault Circuit Interrupter GFGI...Uniform Federal Accessibility Standards UFGs Unified Facility Guide Specifications UFGs Rst UFGS - Reserve Support Team UnICoR Federal Prison Industry
Wartime Roles and Capabilities for the Unified Logistic Staffs
1989-02-01
standard Army ammunition system SAPO Subarea Petroleum Office SCP service control point (fuels) SHAPE Supreme Headquarters, Allied Powers Europe SIDATH... SAPOs ). Communication exists between the operations and logistic staffs within the unified, component, Service, and JS levels. But between...daily. The JPOs/ SAPOs receive the short-term requirements and consoli- date them for resupply by submitting slates (how much, when, and where needed
Chaos synchronization of a unified chaotic system via partial linearization
International Nuclear Information System (INIS)
Yu Yongguang; Li Hanxiong; Duan Jian
2009-01-01
A partial linearization method is proposed for realizing the chaos synchronization of an unified chaotic system. Through synchronizing partial state of the chaotic systems can result in the synchronization of their entire states, and the resulting controller is singularity free. The results can be easily extended to the synchronization of other similar chaotic systems. Simulation results are conducted to show the effectiveness of the method.
Radiative breaking of cosmologically acceptable grand unified theories
International Nuclear Information System (INIS)
Gato, B.; Leon, J.; Quiros, M.
1984-01-01
We present a cosmologically acceptable grand unified model where the breaking of SU(5) proceeds through radiative corrections induced by supergravity soft-breaking terms. The breaking scale is determined by dimensional transmutation. The model is compatible with the radiative breaking of SU(2)sub(L)xU(1)sub(Y) which provides an experimentally accessible low energy particle spectrum and small top quark mass. (orig.)
Z2 vortex strings in grand unified theories
International Nuclear Information System (INIS)
Olive, D.; Turok, N.
1982-01-01
Spontaneously broken gauge theories may display distinct vortex string solutions for the disconnected components of the exact gauge symmetry group. A type of Higgs mechanism thought to apply in grand unified theories as being responsible for fermion masses yields Z 2 vortex lines, irrespectively of the group. These could seed galaxy formation if the corresponding fermion masses are superheavy. More generally a Higgs mechanism producing Zsub(n) vortex strings is presented. (orig.)
A unified BFKL/DGLAP description of deep inelastic scattering
International Nuclear Information System (INIS)
Kwiecinski, J.; Stasto, A. M.; Martin, A. D.
1997-01-01
We introduce a coupled pair of evolution equations for the unintegrated gluon distribution and the sea quark distribution which incorporate both the resummed leading ln(1/x) BFKL contributions and the resummed leading ln(Q 2 ) DGLAP contributions. We solve these unified equations in the perturbative QCD domain. With only two physically motivated parameters we obtain an excellent description of the HERA F 2 data
Globalization and migration: A "unified brain drain" model
Brezis, Elise S.; Soueri, Ariel
2012-01-01
Globalization has led to a vast flow of migration of workers but also of students. The purpose of this paper is to analyze the migration of individuals encompassing decisions already at the level of education. We develop a unified brain drain model that incorporates the decisions of an individual vis - à - vis both education and migration. In the empirical part, this paper addresses international flows of migration within the EU and presents strong evidence of concentration of students in cou...
Unified Stochastic Geometry Model for MIMO Cellular Networks with Retransmissions
Afify, Laila H.
2016-10-11
This paper presents a unified mathematical paradigm, based on stochastic geometry, for downlink cellular networks with multiple-input-multiple-output (MIMO) base stations (BSs). The developed paradigm accounts for signal retransmission upon decoding errors, in which the temporal correlation among the signal-to-interference-plus-noise-ratio (SINR) of the original and retransmitted signals is captured. In addition to modeling the effect of retransmission on the network performance, the developed mathematical model presents twofold analysis unification for MIMO cellular networks literature. First, it integrates the tangible decoding error probability and the abstracted (i.e., modulation scheme and receiver type agnostic) outage probability analysis, which are largely disjoint in the literature. Second, it unifies the analysis for different MIMO configurations. The unified MIMO analysis is achieved by abstracting unnecessary information conveyed within the interfering signals by Gaussian signaling approximation along with an equivalent SISO representation for the per-data stream SINR in MIMO cellular networks. We show that the proposed unification simplifies the analysis without sacrificing the model accuracy. To this end, we discuss the diversity-multiplexing tradeoff imposed by different MIMO schemes and shed light on the diversity loss due to the temporal correlation among the SINRs of the original and retransmitted signals. Finally, several design insights are highlighted.
The performance of FLake in the Met Office Unified Model
Directory of Open Access Journals (Sweden)
Gabriel Gerard Rooney
2013-12-01
Full Text Available We present results from the coupling of FLake to the Met Office Unified Model (MetUM. The coupling and initialisation are first described, and the results of testing the coupled model in local and global model configurations are presented. These show that FLake has a small statistical impact on screen temperature, but has the potential to modify the weather in the vicinity of areas of significant inland water. Examination of FLake lake ice has revealed that the behaviour of lakes in the coupled model is unrealistic in some areas of significant sub-grid orography. Tests of various modifications to ameliorate this behaviour are presented. The results indicate which of the possible model changes best improve the annual cycle of lake ice. As FLake has been developed and tuned entirely outside the Unified Model system, these results can be interpreted as a useful objective measure of the performance of the Unified Model in terms of its near-surface characteristics.
Inverted Unified Power Quality Conditioner to compensate overvoltage
Directory of Open Access Journals (Sweden)
Yeison Alberto Garcés Gómez
2017-07-01
Full Text Available Introduction: The use of unified power quality conditioners UPQC in the electric systems can correct waveform distortions in a steady state, like harmonics, flicker, and the power factor. Objective: This paper presents a novel approach for active compensation of overvoltage with a UPQC in dual topology or iUPQC. Methodology: The study it is presented in five stages, the section I shows an introduction and the state of the art, section II presents the unified power quality conditioner UPQC, section III describes the generalized reactive power theory applied to the iUPQC (dual topology, section IV shows the numerical simulations and the results and section V presents the conclusions of the study. Results: The results for the application of the iUPQC to the compensation of overvoltage are proved and compared with the more representative theory related to compensation of harmonics and low power factor. Conclusions: The control algorithm presented for the unified power quality conditioner in dual topology allows to compensate the overvoltage in three-phase systems as well as voltage and current harmonics and the low power factor.
Unified Stochastic Geometry Model for MIMO Cellular Networks with Retransmissions
Afify, Laila H.; Elsawy, Hesham; Al-Naffouri, Tareq Y.; Alouini, Mohamed-Slim
2016-01-01
This paper presents a unified mathematical paradigm, based on stochastic geometry, for downlink cellular networks with multiple-input-multiple-output (MIMO) base stations (BSs). The developed paradigm accounts for signal retransmission upon decoding errors, in which the temporal correlation among the signal-to-interference-plus-noise-ratio (SINR) of the original and retransmitted signals is captured. In addition to modeling the effect of retransmission on the network performance, the developed mathematical model presents twofold analysis unification for MIMO cellular networks literature. First, it integrates the tangible decoding error probability and the abstracted (i.e., modulation scheme and receiver type agnostic) outage probability analysis, which are largely disjoint in the literature. Second, it unifies the analysis for different MIMO configurations. The unified MIMO analysis is achieved by abstracting unnecessary information conveyed within the interfering signals by Gaussian signaling approximation along with an equivalent SISO representation for the per-data stream SINR in MIMO cellular networks. We show that the proposed unification simplifies the analysis without sacrificing the model accuracy. To this end, we discuss the diversity-multiplexing tradeoff imposed by different MIMO schemes and shed light on the diversity loss due to the temporal correlation among the SINRs of the original and retransmitted signals. Finally, several design insights are highlighted.
Brunini, C.; Sánchez, L.
2008-05-01
SIRGAS is the geocentric reference system for the Americas. Its definition corresponds to the IERS International Terrestrial Reference System (ITRS) and it is realized by a regional densification of the IERS International Terrestrial Reference Frame (ITRF). The SIRGAS activities are coordinated by three working groups: SIRGAS-WGI (Reference System) is committed to establish and maintain a continental-wide geocentric reference frame within the ITRF. This objective was initially accomplished through two continental GPS campaigns in 1995 and 2000, including 58 and 184 stations, respectively. Today, it is realized by around 130 continuously operating GNSS sites, which are processed weekly by the IGS Regional Network Associate Analysis Centre for SIRGAS (IGS- RNAAC-SIR). SIRGAS-WGII (Geocentric Datum) is primarily in charged of defining the SIRGAS geodetic datum in the individual countries, which is given by the origin, orientation and scale of the SIRGAS system, and the parameters of the GRS80 ellipsoid. It is concentrating on promoting and supporting the adoption of SIRGAS in the Latin American and Caribbean countries through national densifications of the continental network. SIRGAS- WGIII (Vertical Datum) is dedicated to the definition and realization of a unified vertical reference system within a global frame. Its central purpose is to refer the geopotential numbers (or physical heights) in all countries to one and the same equipotential surface (W0), which must be globally defined. This includes also the transformation of the existing height datums into the new system. This study shows the SIRGAS achievements of the last two years.
Implications of a Non-Unified Command System and the Need for a Unified Command System in Zambia
2015-06-12
aspects. It has been found that Zambia’s two attempts to unify its system happened during the one party participatory democracy era. Since the coming...and its Implication for Democracy ,” in Ourselves to Know: Civil Military Relations and Defence Transformation in Southern Africa, eds. Rocky Williams...adopted a multiparty system of government under the Movement for Multi-Party Democracy (MMD) which decided to revert to independent commands. As
Namysłowska-Wilczyńska, Barbara; Wynalek, Janusz
2017-12-01
Geostatistical methods make the analysis of measurement data possible. This article presents the problems directed towards the use of geostatistics in spatial analysis of displacements based on geodetic monitoring. Using methods of applied (spatial) statistics, the research deals with interesting and current issues connected to space-time analysis, modeling displacements and deformations, as applied to any large-area objects on which geodetic monitoring is conducted (e.g., water dams, urban areas in the vicinity of deep excavations, areas at a macro-regional scale subject to anthropogenic influences caused by mining, etc.). These problems are very crucial, especially for safety assessment of important hydrotechnical constructions, as well as for modeling and estimating mining damage. Based on the geodetic monitoring data, a substantial basic empirical material was created, comprising many years of research results concerning displacements of controlled points situated on the crown and foreland of an exemplary earth dam, and used to assess the behaviour and safety of the object during its whole operating period. A research method at a macro-regional scale was applied to investigate some phenomena connected with the operation of the analysed big hydrotechnical construction. Applying a semivariogram function enabled the spatial variability analysis of displacements. Isotropic empirical semivariograms were calculated and then, theoretical parameters of analytical functions were determined, which approximated the courses of the mentioned empirical variability measure. Using ordinary (block) kriging at the grid nodes of an elementary spatial grid covering the analysed object, the values of the Z* estimated means of displacements were calculated together with the accompanying assessment of uncertainty estimation - a standard deviation of estimation σk. Raster maps of the distribution of estimated averages Z* and raster maps of deviations of estimation σk (in perspective
Ellis, Andria; DeMets, Charles; Briole, Pierre; Molina, Enrique; Flores, Omar; Rivera, Jeffrey; Lasserre, Cécile; Lyon-Caen, Hélène; Lord, Neal
2014-05-01
As the first large subduction thrust earthquake off the coast of western Guatemala in the past 50 years, the 7 November 2012 Mw=7.4 earthquake offers the first opportunity for a geodetic study of coseismic and postseismic behavior for a segment of the Middle America trench where frictional coupling makes a transition from weak coupling off the coast of El Salvador to strong coupling in southern Mexico. Processing of continuous GPS measurements at 19 stations in Guatemala, El Salvador, and southern Mexico, and at 7 campaign points in Guatemala defines a highly consistent pattern of coseismic offsets during the earthquake, ranging from 47±5 mm of SW movement just inland from the earthquake epicenter to a few mm at sites located in northern Guatemala. Inversions of these offsets to find their best-fitting fault-slip solution in an elastic half space give a geodetic earthquake moment ranging between 0.75 and 1.1 x 1020 Nm, slightly smaller than the seismic estimates that range between 1.2 and 1.45 x 1020 Nm. Slip inversion using a constant slip model, assuming 293° and 29° for the fault azimuth and dip angle, indicates a nearly reverse slip of 2.8 m (rake 78°) on a fault plane 42 km-long and 20 km-wide, centered at 26 km depth. A variable slip inversion indicates that slip concentrated above depths of 40 km may have extended updip to the trench and reached a maximum of only 0.8 m, less than one-sixth the maximum slip indicated by a recent slip solution (5.3 m) obtained from waveform inversion of seismological data. Detailed model comparisons will be discussed. Transient postseismic displacements have been recorded at the nearby continuous GPS sites with amplitudes reaching 20-25 mm at some stations. The duration of the phenomenon is short: using an exponential-decay model, the estimated decay time is 90 ± 10 days. This postseismic signal is consistent with afterslip along a significantly broader area (+50%) of the subduction interface than ruptured coseismically
Ellis, Andria P.; DeMets, Charles; Briole, Pierre; Molina, Enrique; Flores, Omar; Rivera, Jeffrey; Lasserre, Cécile; Lyon-Caen, Hélène; Lord, Neal
2015-05-01
As the first large subduction thrust earthquake off the coast of western Guatemala in the past several decades, the 2012 November 7 Mw = 7.4 earthquake offers the first opportunity to study coseismic and postseismic behaviour along a segment of the Middle America trench where frictional coupling makes a transition from weak coupling off the coast of El Salvador to strong coupling in southern Mexico. We use measurements at 19 continuous GPS sites in Guatemala, El Salvador and Mexico to estimate the coseismic slip and postseismic deformation of the November 2012 Champerico (Guatemala) earthquake. An inversion of the coseismic offsets, which range up to ˜47 mm at the surface near the epicentre, indicates that up to ˜2 m of coseismic slip occurred on a ˜30 × 30 km rupture area between ˜10 and 30 km depth, which is near the global CMT centroid. The geodetic moment of 13 × 1019 N m and corresponding magnitude of 7.4 both agree well with independent seismological estimates. Transient postseismic deformation that was recorded at 11 GPS sites is attributable to a combination of fault afterslip and viscoelastic flow in the lower crust and/or mantle. Modelling of the viscoelastic deformation suggests that it constituted no more than ˜30 per cent of the short-term postseismic deformation. GPS observations that extend six months after the earthquake are well fit by a model in which most afterslip occurred at the same depth or directly downdip from the rupture zone and released energy equivalent to no more than ˜20 per cent of the coseismic moment. An independent seismological slip solution that features more highly concentrated coseismic slip than our own fits the GPS offsets well if its slip centroid is translated ˜50 km to the west to a position close to our slip centroid. The geodetic and seismologic slip solutions thus suggest bounds of 2-7 m for the peak slip along a region of the interface no larger than 30 × 30 km.
NSGIC Local Govt | GIS Inventory — Geodetic Control Points dataset current as of 2011. Chippewa County has been working on tightening up their control network over the years. The first network was...
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Cemal Ozer Yigit
2016-07-01
Full Text Available The present study evaluates the dynamic behaviour of the Ermenek Dam, the second highest dam in Turkey, based on conventional geodetic measurements and Finite Element Model (FEM analyses during its first filling period. In total, eight periods of measured deformation are considered from the end of construction until the reservoir reached its full capacity. The displacement response of the dam to the reservoir level and to seasonal temperature variations is examined in detail. Time series of apparent total displacements at the middle of the crest of the dam exhibits periodicity and linear trends. Correlation analysis revealed that periodic and linear displacement responses of the dam are related to variations of seasonal temperature and linearly increased reservoir level, respectively, indicating a relation between temperature, water load and dam deformation. It is also concluded that measured deformations based on geodetic data show good agreement with the predicted deformation obtained by the FEM analysis.
Polet, J.; Alvarez, K.; Elizondo, K.
2017-12-01
In the early 1980's and 1990's numerous leveling lines and dry tilt arrays were installed throughout Central and Southern California by United States Geological Survey scientists and other researchers (e.g. Sylvester, 1985). These lines or triangular arrays of geodetic monuments commonly straddle faults or have been installed close to volcanic areas, where significant motion is expected over relatively short time periods. Over the past year, we have incorporated geodetic surveys of these arrays as part of our field exercises in undergraduate and graduate level classes on topics such as shallow subsurface geophysics and field geophysics. In some cases, the monuments themselves first had to be located based on only limited information, testing students' Brunton use and map reading skills. Monuments were then surveyed using total stations and global navigation satellite system (GNSS) receivers, using a variety of experimental procedures. The surveys were documented with tables, photos, maps and graphs in field reports, as well as in wiki pages created by student groups for a geophysics field class this June. The measurements were processed by the students and compared with similar data from surveys conducted soon after installation of the arrays, to analyze the deformation that occurred over the last few decades. The different geodetic techniques were also compared and an error analysis was conducted. The analysis and processing of these data challenged and enhanced students' quantitative literacy and technology skills. The final geodetic measurements are being incorporated into several senior and MSc thesis projects. Further surveys are planned for additional classes, in topics that could include seismology, geodesy, volcanology and global geophysics. We are also considering additional technologies, such as structure from motion (SfM) photogrammetry.