A Nonextensive Statistical Physics Analysis of the 1995 Kobe,Japan Earthquake     

Giorgos Papadakis  Filippos Vallianatos  Peter Sammonds 《Pure and Applied Geophysics》2015,172(7):1923-1931

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Earthquake response of two repaired buildings damaged in past seismic shaking     

A. S. Papageorgiou 《Soil Dynamics and Earthquake Engineering》1991,10(5)

Two reinforced concrete buildings which suffered architectural and minor structural damage during the 1971 San Fernando earthquake, were shaken again by the 1987 Whittier Narrows earthquake. Their well recorded responses are analyzed employing a system identification technique. Comparison of the vibration parameters inferred from analyses of the Whittier earthquake response to the corresponding parameters inferred from dynamic response data before, during and after the San Fernando earthquake verify the adequacy of the repairs made on the structures. Also, comparison of the recorded dynamic responses with the design code requirements provides supporting evidence for the adequacy of current design practices.  相似文献   

The Barrier Model and Strong Ground Motion     

A. S. Papageorgiou 《Pure and Applied Geophysics》2003,160(3-4):603-634

— An overview of the most important developments in Engineering (or Strong Motion) Seismology is presented alongside Professor Keiiti Aki's contributions, who is one of the founders of this field. The mechanics of earthquake rupture are discussed with due emphasis on the various physical phenomena. The presentation is made in a tutorial manner, borrowing freely from Keiiti Aki's papers, and endeavoring to emulate his unique style of clarity, simplicity and synthetic ability.  相似文献   

Adaptable User Profiles for Intelligent Geospatial Queries   总被引：1，自引：0，他引：1  

Giorgos Mountrakis  Peggy Agouris  Anthony Stefanidis 《Transactions in GIS》2005,9(4):561-583

The geospatial information user community is becoming increasingly diverse, with numerous users accessing distributed datasets for various types of applications. Currently in GIS, unlike traditional databases, there is a lack of machine learning algorithms to customize information retrieval results. Thus the particular interests of individual users are not taken into account in traditional geospatial queries. In this paper we present a system that adjusts query results based on user requirements and needs. It does so by using a collection of fuzzy functions that express user preference specifically in GIS environments. The focus of this work is on preference learning for one‐dimensional, quantitative attributes, and on the customization of geospatial queries using this information. The model used to express user preferences adjusts gradually to the underlying complexity during a training process, starting with fairly simple linear functions and progressing to complex non‐linear ones as needed. Our advanced modeling capabilities are demonstrated through an applicability example, and statistical simulations show the robustness of our system.  相似文献   

Response of base-isolated buildings to random excitations described by the Clough-Penzien spectral model     

B. C. Lin  I. G. Tadjbakhsh  A. S. Papageorgiou  G. Ahmadi 《地震工程与结构动力学》1989,18(1):49-62

The stationary response of base-isolated buildings subjected to earthquake excitation is studied. The frequency content of earthquake input is described by the Clough-Penzien spectral model. The response parameters of interest are (1) the root-mean-square (RMS) displacement σ_x of the basement relative to the foundation (i.e. shear deformation of the isolation system) and (2) the ratio (σ_a/σ_a0) of the RMS value of the absolute acceleration at the roof of the isolated structure over the corresponding value when the isolation system is locked. The variation of these response parameters with the effective frequency f₀ of the base-isolated structure is investigated. As input, earthquakes with moment magnitudes M = 7-3 and M = 6-0 are considered. The acceleration spectra corresponding to these two earthquake sizes have pronouncedly different frequency content over the frequency range 0–1-1–0 Hz which is of primary importance for base-isolated structures. An important conclusion that comes from these analyses is that confidence in the effectiveness of a base-isolated system should be based primarily on its capacity to absorb/dissipate energy and less on its influence in shifting the fundamental period of the structure out of the range of dominant earthquake energy.  相似文献   

Church repair swarms and earthquakes in Rhodes Island, Greece   总被引：1，自引：0，他引：1  

S. Stiros  S. Papageorgiou  V. Kontogianni  P. Psimoulis 《Journal of Seismology》2006,10(4):527-537

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Response of tall buildings to base rocking induced by Rayleigh waves          下载免费PDF全文

Kristel C. Meza Fajardo  Apostolos S. Papageorgiou 《地震工程与结构动力学》2018,47(8):1755-1773

By now, it is well known that long‐period surface waves can induce resonant response in high‐rise buildings, in particular those located in sedimentary basins. Rayleigh wave passage has been reported to induce rocking motion at the base of the buildings which can increase displacement demands significantly. However, the building behavior to base rocking has not been extensively studied because commercially available instruments do not record rotational components of ground motion, and thus, rocking time histories have not been available to the analysts. In a recent study, we proposed an effective method for estimating the rocking associated with Rayleigh waves, which takes into account their frequency‐dependent phase velocities. In the present work, we select a number of recorded seismic motions which include surface waves on sedimentary basins from recent well‐recorded earthquake events. Then, we proceed to identify and extract the recorded surface waves by using the technique mentioned above. Using realistic soil‐structure analytical models that have been proposed in the published literature for high‐rise buildings, we study their response to Rayleigh waves as they respond to both translational and rocking motions. Of particular interest is to compare the response of such structures with and without the presence of rotational motions due to surface waves. Using the roof displacement and the building interstory drift as response quantities, our results indicate that demands are controlled by rotational (rocking) motions associated with Rayleigh waves.  相似文献   

Language‐Independent Access to History Textbooks: Utilizing GIS Functionality with Spatiotemporal and Thematic Metadata     

Dieter Pfoser  Alexandros Efentakis  Thanasis Hadzilacos  Sophia Karagiorgou  Giorgos Vasiliou 《Transactions in GIS》2010,14(6):773-790

Integrating and accessing structured textual content obtained from different sources is a challenging task and becomes even more so when dealing with multiple languages. The objective of this article is to showcase the technological efforts towards the creation of a digital European history textbook repository that integrates respective textbooks from various countries and publishers. The content integration is achieved by introducing language independent metadata based on space (locations), time (dates), and thematic categories (history gazetteer). Providing adequate interfaces such metadata can be used to offer language‐independent access to Multilanguage history textbook content. The specific focus in this article will be on (1) presenting the metadata, (2) the data management approach including indexing the history textbook content and (3) the resulting textbook repository including its GIS‐based interface, allowing for a combination of map, timeline and keyword based search of the history content.  相似文献   

Image based remote sensing method for modeling black-eyed beans (Vigna unguiculata) Leaf Area Index (LAI) and Crop Height (CH) over Cyprus     

Giorgos Papadavid  Dionysia Fasoula  Michael Hadjimitsis  P. Skevi Perdikou  Diofantos G. Hadjimitsis 《Central European Journal of Geosciences》2013,5(1):1-11

In this paper, Leaf Area Index (LAI) and Crop Height (CH) are modeled to the most known spectral vegetation index — NDVI — using remotely sensed data. This approach has advantages compared to the classic approaches based on a theoretical background. A GER-1500 field spectro-radiometer was used in this study in order to retrieve the necessary spectrum data for estimating a spectral vegetation index (NDVI), for establishing a semiempirical relationship between black-eyed beans’ canopy factors and remotely sensed data. Such semi-empirical models can be used then for agricultural and environmental studies. A field campaign was undertaken with measurements of LAI and CH using the Sun-Scan canopy analyzer, acquired simultaneously with the spectroradiometric (GER1500) measurements between May and June of 2010. Field spectroscopy and remotely sensed imagery have been combined and used in order to retrieve and validate the results of this study. The results showed that there are strong statistical relationships between LAI or CH and NDVI which can be used for modeling crop canopy factors (LAI, CH) to remotely sensed data. The model for each case was verified by the factor of determination. Specifically, these models assist to avoid direct measurements of the LAI and CH for all the dates for which satellite images are available and support future users or future studies regarding crop canopy parameters.  相似文献   

Hygroscopic properties of aerosol particles in the north‐eastern Atlantic during ACE‐2     

Erik Swietlicki  Jingchuan Zhou  David S. Covert  Kaarle Hämeri  Bernhard Busch  Minna Väkeva  Ulrike Dusek  Olle H. Berg  Alfred Wiedensohler  Pasi Aalto  Jyrki Mäkelä  Bengt G. Martinsson  Giorgos Papaspiropoulos  Besim Mentes  Göran Frank  Frank Stratmann 《Tellus. Series B, Chemical and physical meteorology》2000,52(2):201-227

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