1,411 research outputs found

    Results of phase one of land use information Delphi study

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    The Land Use Management Information System (LUMIS) is being developed for the city portion of the Santa Monica mountains. LUMIS incorporates data developed from maps and aerial photos as well as traditional land based data associated with routine city and county record keeping activities and traditional census data. To achieve the merging of natural resource data with governmental data LUMIS is being designed in accordance with restrictions associated with two other land use information systems currently being constructed by Los Angeles city staff. The two city systems are LUPAMS (Land Use Planning and Management System) which is based on data recorded by the County Assessor's office for each individual parcel of land in the city, and Geo-BEDS, a geographically based environmental data system

    The availability of local aerial photography in southern California

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    Some of the major photography and photogrammetric suppliers and users located in Southern California are listed. Recent trends in aerial photographic coverage of the Los Angeles basin area are also noted, as well as the uses of that imagery

    LUMIS Interactive graphics operating instructions and system specifications

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    The LUMIS program has designed an integrated geographic information system to assist program managers and planning groups in metropolitan regions. Described is the system designed to interactively interrogate a data base, display graphically a portion of the region enclosed in the data base, and perform cross tabulations of variables within each city block, block group, or census tract. The system is designed to interface with U. S. Census DIME file technology, but can accept alternative districting conventions. The system is described on three levels: (1) introduction to the systems's concept and potential applications; (2) the method of operating the system on an interactive terminal; and (3) a detailed system specification for computer facility personnel

    An automatic deep learning approach for coronary artery calcium segmentation

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    Coronary artery calcium (CAC) is a significant marker of atherosclerosis and cardiovascular events. In this work we present a system for the automatic quantification of calcium score in ECG-triggered non-contrast enhanced cardiac computed tomography (CT) images. The proposed system uses a supervised deep learning algorithm, i.e. convolutional neural network (CNN) for the segmentation and classification of candidate lesions as coronary or not, previously extracted in the region of the heart using a cardiac atlas. We trained our network with 45 CT volumes; 18 volumes were used to validate the model and 56 to test it. Individual lesions were detected with a sensitivity of 91.24%, a specificity of 95.37% and a positive predicted value (PPV) of 90.5%; comparing calcium score obtained by the system and calcium score manually evaluated by an expert operator, a Pearson coefficient of 0.983 was obtained. A high agreement (Cohen's k = 0.879) between manual and automatic risk prediction was also observed. These results demonstrated that convolutional neural networks can be effectively applied for the automatic segmentation and classification of coronary calcifications

    Temperature and Emission-Measure Profiles Along Long-Lived Solar Coronal Loops Observed with TRACE

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    We report an initial study of temperature and emission measure distributions along four steady loops observed with the Transition Region and Coronal Explorer (TRACE) at the limb of the Sun. The temperature diagnostic is the filter ratio of the extreme-ultraviolet 171-angstrom and 195-angstrom passbands. The emission measure diagnostic is the count rate in the 171-angstrom passband. We find essentially no temperature variation along the loops. We compare the observed loop structure with theoretical isothermal and nonisothermal static loop structure.Comment: 10 pages, 3 postscript figures (LaTeX, uses aaspp4.sty). Accepted by ApJ Letter

    Collisional Plasma Models with APEC/APED: Emission Line Diagnostics of Hydrogen-like and Helium-like Ions

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    New X-ray observatories (Chandra and XMM-Newton) are providing a wealth of high-resolution X-ray spectra in which hydrogen- and helium-like ions are usually strong features. We present results from a new collisional-radiative plasma code, the Astrophysical Plasma Emission Code (APEC), which uses atomic data in the companion Astrophysical Plasma Emission Database (APED) to calculate spectral models for hot plasmas. APED contains the requisite atomic data such as collisional and radiative rates, recombination cross sections, dielectronic recombination rates, and satellite line wavelengths. We compare the APEC results to other plasma codes for hydrogen- and helium-like diagnostics, and test the sensitivity of our results to the number of levels included in the models. We find that dielectronic recombination with hydrogen-like ions into high (n=6-10) principal quantum numbers affects some helium-like line ratios from low-lying (n=2) transitions.Comment: 5 pages, 6 figures, accepted by ApJ Letter

    Superflares on Ordinary Solar-Type Stars

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    Short duration flares are well known to occur on cool main-sequence stars as well as on many types of `exotic' stars. Ordinary main-sequence stars are usually pictured as being static on time scales of millions or billions of years. Our sun has occasional flares involving up to 1031\sim 10^{31} ergs which produce optical brightenings too small in amplitude to be detected in disk-integrated brightness. However, we identify nine cases of superflares involving 103310^{33} to 103810^{38} ergs on normal solar-type stars. That is, these stars are on or near the main-sequence, are of spectral class from F8 to G8, are single (or in very wide binaries), are not rapid rotators, and are not exceedingly young in age. This class of stars includes many those recently discovered to have planets as well as our own Sun, and the consequences for any life on surrounding planets could be profound. For the case of the Sun, historical records suggest that no superflares have occurred in the last two millennia.Comment: 16 pages, accepted for publication in Ap

    L’influenza dell’attaccamento e della sensibilità diadica genitorialesullo sviluppo psicomotorio del bambino nato pretermine

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    Lo scopo di questa ricerca è studiare i precursori dell’attaccamento e la sensibilità diadica genitoriale nelle famiglie con bambino nato pretermine. Sono state considerate 110 famiglie delle quali 55 con figli nati pretermine ( peso alla nascita < 1500 gr.) per un totale di 330 soggetti valutati durante i primi sei mesi di età corretta del bambino. Le diadi madre-bambino e padre-bambino sono state sottoposte al CARE-Index, una procedura videoregistrata per la valutazione dei precursori dell’attaccamento; ad entrambi i genitori sono stati somministrati CES-D, per la valutazione della depressione e STAI Y-2, per la valutazione dell’ansia di tratto. Lo sviluppo psicomotorio dei neonati è stato valutato tramite le scale Bayley. Rispetto ai controlli, nelle madri dei bambini pretermine sono stati evidenziati bassi punteggi di Sensibilità Diadica al CARE-Index (p=.025) ed elevati livelli di ansia (p=.026). Nei padri sono stati riscontrati bassi punteggi di Sensibilità Diadica (p=.004) e alti livelli di sintomi depressivi (p=.003). Nelle famiglie pretermine i precursori dell’attaccamento sono più frequentemente di tipo insicuro nelle madri (p=.000) e nei padri (p=.000), mentre nei neonati solo nell’interazione con la madre (p=012). Questi fattori sono risultati associati a minori punteggi alle scale Bayley (p=.000). Nelle madri dei neonati pretermine si riscontrano frequenti difficoltà con la famiglia di origine, nei padri una percezione negativa del proprio bambino e una maggiore insoddisfazione per l’assistenza ricevuta. Questi risultati evidenziano che il 40% delle madri e il 75% dei padri dei bambini nati pretermine rientra nella fascia ad alto rischio del CARE-Index (che richiede un trattamento psicologico e/o farmacologico). In tali casi, la scarsa sensibilità diadica, i precursori di attaccamento insicuro e le difficoltà psicologiche dei genitori sembrano influenzare lo sviluppo psicomotorio del bambino

    EUV emission lines and diagnostics observed with Hinode/EIS

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    Quiet Sun and active region spectra from the Hinode/EIS instrument are presented, and the strongest lines from different temperature regions discussed. A list of emission lines recommended to be included in EIS observation studies is presented based on analysis of blending and diagnostic potential using the CHIANTI atomic database. In addition we identify the most useful density diagnostics from the ions covered by EIS.Comment: 14 pages, 3 figures, submitted to PASJ Hinode first results issu

    A solar active region loop compared with a 2D MHD model

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    We analyzed a coronal loop observed with the Normal Incidence Spectrometer (NIS), which is part of the Coronal Diagnostic Spectrometer (CDS) on board the Solar and Heliospheric Observatory (SOHO). The measured Doppler shifts and proper motions along the selected loop strongly indicate unidirectional flows. Analysing the Emission Measure Curves of the observed spectral lines, we estimated that the temperature along the loop was about 380000 K. We adapted a solution of the ideal MHD steady equations to our set of measurements. The derived energy balance along the loop, as well as the advantages/disadvantages of this MHD model for understanding the characteristics of solar coronal loops are discussed.Comment: A&A in press, 10 pages, 6 figure
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