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Tehran, Iran

International Institute of Earthquake Engineering and Seismology , founded by Mohsen Ghafory-Ashtiany, is an international earthquake engineering and seismology institute based in Iran. It was established as a result of the 24th UNESCO General Conference Resolution DR/250 under Iranian government approval in 1989. It was founded as an independent institute within the Iran’s Ministry of Science, Research and Technology.Mohsen Ghafory-Ashtiany distinguished professor of earthquake engineering and risk management at International Institute of Earthquake Engineering and seismology which was founded by him in 1989, is Chief Editor of JSEE and IDRiM Journals; author of more than 140 papers and 3 books in the field of earthquake engineering, seismic hazard and risk analysis, risk management and planning. Ashtiany is the Director and member of the Executive committee of International Association of Earthquake engineering , Chairman of Earthquake Hazard, Risk and Strong Ground Motion Commission of IASPEI, member of UN-ISDR Scientific and Technical commission, Director and member of board of World Seismic Safety Initiative, member of Global Earthquake Risk Model Project; Member of Geo-Hazard Initiative, Member of GSHAP, Member of Global Risk Forum-Davos, and many other scientific communities. Ashtiany was born in Tehran, Iran in 1957 and graduated from Va. Tech in 1983 with honor, and is resident of US.On its establishment, the IIEES drew up a seismic code in an attempt to improve the infrastructural response to earthquakes and seismic activity in the country. Its primary objective is to reduce the risk of seismic activity on buildings and roads and provide mitigation measures both in Iran and the region.The institute is responsible for much of the research and education in this field by conducting research and providing education and knowledge in seismotectonic studies, seismology and earthquake engineering. In addition conducts research and educates in risk management and generating possibilities for an effective earthquake response strategy. The IIEES is composed of the following research Centers: Seismology, Geotechnical Earthquake Engineering, Structural Earthquake Engineering, Risk Management; National center for Earthquake Prediction, and Graduate School, Public Education and Information Division. Wikipedia.

Mokhtari M.,International Institute of Earthquake Engineering and Seismology
Natural Hazards

Iran has long been known as one of the most seismically active areas of the world, and it frequently suffers destructive and catastrophic earthquakes that cause heavy loss of human life and widespread damage. The Alborz region in the northern part of Iran is an active EW trending mountain belt of 100 km wide and 600 km long. The Alborz range is bounded by the Talesh Mountains to the west and the Kopet Dagh Mountains to the east and consists of several sedimentary and volcanic layers of Cambrian to Eocene ages that were deformed during the late Cenozoic collision. Several active faults affect the central Alborz. The main active faults are the North Tehran and Mosha faults. The Mosha fault is one of the major active faults in the central Alborz as shown by its strong historical seismicity and its clear morphological signature. Situated in the vicinity of Tehran city, this 150-km-long N100° E trending fault represents an important potential seismic source. For earthquake monitoring and possible future prediction/precursory purposes, a test site has been established in the Alborz mountain region. The proximity to the capital of Iran with its high population density, low frequency but high magnitude earthquake occurrence, and active faults with their historical earthquake events have been considered as the main criteria for this selection. In addition, within the test site, there are hot springs and deep water wells that can be used for physico-chemical and radon gas analysis for earthquake precursory studies. The present activities include magnetic measurements; application of methodology for identification of seismogenic nodes for earthquakes of M ≥ 6.0 in the Alborz region developed by International Institute of Earthquake Prediction Theory and Mathematical Geophysics, IIEPT RAS, Russian Academy of Science, Moscow (IIEPT&MG RAS); a feasibility study using a dense seismic network for identification of future locations of seismic monitoring stations and application of short-term prediction of medium- and large-size earthquakes is based on Markov and extended self-similarity analysis of seismic data. The establishment of the test site is ongoing, and the methodology has been selected based on the IASPEI evaluation report on the most important precursors with installation of (i) a local dense seismic network consisting of 25 short-period seismometers, (ii) a GPS network consisting of eight instruments with 70 stations, (iii) magnetic network with four instruments, and (iv) radon gas and a physico-chemical study on the springs and deep water wells. © Springer Science+Business Media B.V. 2009. Source

Hosseini Hashemi B.,International Institute of Earthquake Engineering and Seismology | Jafari M.A.,Niroo Research Institute
Journal of Constructional Steel Research

This research was performed to evaluate two analytical methods for predicting the compressive strength of batten columns. Batten columns were subjected to pure axial compression, and the compressive strength was measured. The analytical methods used included the well-known Ayrton-Perry and ultimate strength curve methods to calculate the compressive strength of imperfect solid web columns, but their validity has not yet been studied experimentally on built-up columns. The geometrical parameters considered included the batten plate spacing and dimensions and the distance between the two longitudinal chords. The results show that the analytical methods were generally valid for the prediction of the compressive strength in batten columns and solid web columns. Using the average results of the Ayrton-Perry and ultimate strength curve methods leads to the best prediction of the column compressive strength. It was also shown that the initial imperfections in the batten columns could have a more important effect than the geometrical specifications on the value of compressive strength. © 2011 Elsevier Ltd. Source

Hamzehloo H.,International Institute of Earthquake Engineering and Seismology | Mahood M.,Islamic Azad University at Tehran
Bulletin of the Seismological Society of America

Predictive attenuation relationships have been developed for peak ground acceleration and spectral coordinates based on observed and simulated records for East Central Iran. First, the predictive relationships are derived based on observed records. The observed data set, which was considered, includes a total of 258 records from 109 earthquakes with a magnitude range of 5.0-7.4 on rock site. Then a suite of ground motions has been simulated for a range of magnitude and distances based on the stochastic finite fault ground-motion model. The theoretical-empirical attenuation relationship, which has been developed for the horizontal component of peak ground acceleration and spectral acceleration, is applicable to earthquakes of Mw 5.0-7.4 at a distance up to 100 km. Source

Zafarani H.,International Institute of Earthquake Engineering and Seismology | Soghrat M.,Tarbiat Modares University
Bulletin of the Seismological Society of America

Physically based ground-motion prediction equations for soil and rock sites in the Zagros region have been developed based on the specific barrier model (SBM) used within the context of the stochastic model. Instead of direct timedomain simulation, random vibration theory was used to estimate measures of peak motion in terms of the pseudospectral velocity of anelastic harmonic oscillator with 5% viscous damping. To avoid the uncertainties, calibration of the source model uses a database of carefully selected strong motion data without ambiguity about the site condition. Therefore, only rock sites are selected for determining source parameters. Also, to avoid any inconsistencies caused by magnitude conversion formulas, we restricted the dataset only to events with available moment magnitudes. Regression analysis is performed using the random effects model that considers both interevent and intraevent variabilities to effectively deal with the problem of an unequal number of records from different earthquakes. No sign of self-similarity breakdown is observed between the source radius and its seismic moment. The local and global stress drops derived for the Zagros region (39 and 116 bars, respectively) are more consistent with the values obtained by other authors for an interplate regime than the values for an intraplate region. However, from the viewpoint of source heterogeneity (as the ratio of the stress drops is an indicator of the complexity of the source and heterogeneity of slip on the fault) the Zagros events, which have a stress-drop ratio of about three are more homogeneous than other interplate events. Stochastic simulations are then implemented to predict peak ground motion and response spectra parameters for rock and soil site conditions. Source

Husseinzadeh Kashan A.,Tarbiat Modares University | Husseinzadeh Kashan M.,Tarbiat Modares University | Karimiyan S.,International Institute of Earthquake Engineering and Seismology
Information Sciences

Many combinatorial optimization problems comprise a grouping phase (the grouping problem) in which the task is to partition a set of items into disjoint sets. Introduced in 1994, grouping genetic algorithm (GGA) is the only evolutionary algorithm heavily modified to suit the structure of grouping problems. In this paper we adapt the structure of the well-known particle swarm optimization algorithm (PSO) for grouping problems. To propose the grouping version of the PSO algorithm, which is called GPSO algorithm, we develop new particle position and velocity updating equations which preserve the major characteristics of the original equations and are respondent to the structure of grouping problems. The new updating equations work with groups of items rather than items isolatedly. One of the main characteristics of the new equations is that they work in continuous space but their outcome is used in discrete space through a two phase procedure. Applications of GPSO algorithm are made to the single batch-machine scheduling problem and bin packing problem, and results are compared with the results reported by GGA. Computational results testify that our algorithm is efficient and can be regarded as a new solver for the wide class of grouping problems. © 2012 Published by Elsevier Inc. Source

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