scholarly journals SIMULATION OF SOIL LIQUEFACTION DUE TO EARTHQUAKE LOADING USING THE UBC3D-PLM MODEL

2019 ◽  
Vol 7 (3) ◽  
pp. 39-44
Author(s):  
Armen Ter-martirosyan ◽  
Osman Ahmad
Keyword(s):  
Los Angeles ◽  
Process Model ◽  
Soil Mass ◽  
Seismic Effect ◽  
Soil Liquefaction ◽  
Elastic Behavior ◽  
Soil Behavior ◽  
Basic Step ◽  
Seismic Impact ◽  
The Impact

Liquefaction is a phenomenon in which the stiffness and strength of a soil are reduced as a result of seismic effect or other dynamic effects. Liquefaction was the basic reason of the big damages caused by many earthquakes around the world. The basic step in the processes of predicting the soil liquefaction is the modeling of soil behavior. At the present time, numerous soil models are presented. Nevertheless, only some of them can simulate this process. Model UBC3D-PLM is one of these models which can be used. In this paper, the possibilities of this model are considered by modeling on the PLAXIS software package the seismic impact on a building with its different heights. The actual data of Upland earthquake 1990 near Los Angeles city was used. Results of this simulation showed us the difference in the behavior of the soil mass under the impact of an earthquake compared with the elastic behavior, as well as showed us the necessary to use the UBC3D-PLM model to estimate the seismic impact.

scholarly journals Simulation of soil liquefaction due to earthquake loading

2019 ◽  
Vol 97 ◽  
pp. 03025 ◽  
Author(s):  
Armen Ter-Martirosyan ◽  
Ahmad Othman
Keyword(s):  
Los Angeles ◽  
Real Data ◽  
Soil Mass ◽  
Soil Liquefaction ◽  
Elastic Behavior ◽  
Main Step ◽  
Soil Behavior ◽  
The Difference ◽  
Strength And Stiffness ◽  
Seismic Impact

Liquefaction is a phenomenon in which the strength and stiffness of a soil are reduced as a result of seismic or other dynamic effects. Liquefaction was the main reason of the huge damages caused by many earthquakes around the world. The modeling of soil behavior is the main step in the process of predicting the soil liquefaction. Currently, a large number of soil models are presented. However, only some of them can simulate this process. One of these models which can be used is model UBC3D-PLM. In this paper, the possibilities of this model are considered by modeling the seismic impact on a building with its different heights on the PLAXIS software package. The real data of Upland earthquake 1990 near Los Angeles city was used. Results of the simulation showed the difference in the behavior of the soil mass under the influence of an earthquake compared with the elastic behavior, as well as the need to use the UBC3D-PLM model to estimate the seismic impact.

scholarly journals A critical assessment of the Burning Index in Los Angeles County, California

2007 ◽  
Vol 16 (4) ◽  
pp. 473 ◽  
Author(s):  
Frederic P. Schoenberg ◽  
Chien-Hsun Chang ◽  
Jon E. Keeley ◽  
Jamie Pompa ◽  
James Woods ◽  
...  
Keyword(s):  
Wind Speed ◽  
Los Angeles ◽  
Relative Humidity ◽  
Process Model ◽  
Los Angeles County ◽  
Wildfire Occurrence ◽  
Simple Alternative ◽  
Individual Variables ◽  
Burning Index ◽  
The Impact

The Burning Index (BI) is commonly used as a predictor of wildfire activity. An examination of data on the BI and wildfires in Los Angeles County, California, from January 1976 to December 2000 reveals that although the BI is positively associated with wildfire occurrence, its predictive value is quite limited. Wind speed alone has a higher correlation with burn area than BI, for instance, and a simple alternative point process model using wind speed, relative humidity, precipitation and temperature well outperforms the BI in terms of predictive power. The BI is generally far too high in winter and too low in fall, and may exaggerate the impact of individual variables such as wind speed or temperature during times when other variables, such as precipitation or relative humidity, render the environment ill suited for wildfires.

The Doctor Faustus Dossier

2018 ◽  
Author(s):  
Adrian Daub
Keyword(s):  
Twentieth Century ◽  
Los Angeles ◽  
Primary Source ◽  
Music And Literature ◽  
Twentieth Century Music ◽  
Private And Public ◽  
Doctor Faustus ◽  
Public Lives ◽  
Nazi Era ◽  
The Impact

Arnold Schoenberg and Thomas Mann, two towering figures of twentieth-century music and literature, both found refuge in the German-exile community in Los Angeles during the Nazi era. This complete edition of their correspondence provides a glimpse inside their private and public lives and culminates in the famous dispute over Mann's novel Doctor Faustus. In the thick of the controversy was Theodor Adorno, then a budding philosopher, whose contribution to the Faustus affair would make him an enemy of both families. Gathered here for the first time in English, the letters are complemented by diary entries, related articles, and other primary source materials, as well as an introduction that contextualizes the impact that these two great artists had on twentieth-century thought and culture.

scholarly journals Evaluating interventions with victims of intimate partner violence: a community psychology approach

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Cinzia Albanesi ◽  
Carlo Tomasetto ◽  
Veronica Guardabassi
Keyword(s):  
Intimate Partner Violence ◽  
Social Services ◽  
Psychological Health ◽  
Partner Violence ◽  
Process Model ◽  
Professional Training ◽  
Phenomenological Approach ◽  
Intimate Partner ◽  
Structured Interviews ◽  
The Impact

Abstract Purpose Intimate Partner Violence (IPV) is one of the most common forms of domestic violence, with profound implication for women's physical and psychological health. In this text we adopted the Empowerment Process Model (EPM) by Cattaneo and Goodman (Psychol Violence 5(1):84–94) to analyse interventions provided to victims of IPV by a Support Centre for Women (SCW) in Italy, and understand its contribution to women’s empowerment. Method We conducted semi-structured interviews with ten women who had been enrolled in a program for IPV survivors at a SCW in the past three years. The interviews focused on the programs’ aims, actions undertaken to reach them, and the impact on the women’s lives, and were analysed using an interpretative phenomenological approach. Results Results showed that the interventions provided by the SWC were adapted according to women's needs. In the early phases, women’s primary aim was ending violence, and the intervention by the SCW was deemed as helpful to the extent it provided psychological support, protection and safe housing. Women’s aims subsequently moved to self-actualisation and economic and personal independence which required professional training, internships, and social support. Although satisfying the majority of the women’s expectations, other important needs (e.g., economic support or legal services) were poorly addressed, and cooperation with other services (e.g., police or social services) was sometimes deemed as critical. Conclusions By evaluating a program offered by a SCW to IPV survivors through the lens of the EPM model, we found that women deemed the program as effective when both individual resources and empowerment processes were promoted. Strengths, limitations and implications are discussed.

A multiscale homogenization procedure to predict the elasto-viscoplastic behavior of polymer-based nanocomposites

2021 ◽  
pp. 096739112110233
Author(s):  
Mohammad Hassan Shojaeefard ◽  
Abolfazl Khalkhali ◽  
Sharif Khakshournia
Keyword(s):  
Design Procedure ◽  
Polymeric Matrix ◽  
Elastic Behavior ◽  
Algorithm Optimization ◽  
Multiphase Materials ◽  
Rate Dependent ◽  
Main Challenge ◽  
Compressive Loads ◽  
Structural Parts ◽  
The Impact

It has been demonstrated that adding a few percent of nanoscale reinforcements, leads to remarkable improvement in mechanical properties of the polymers such as stiffness, damping, and energy absorption. These lightweight materials are attractive substitutes for the heavy metallic structural parts in the automotive, military, aerospace and many other industries. However, due to complexity of these multiphase materials, accurate modeling of their behavior in real loading cases is still ambiguous. The impact simulation is a vital step in design procedure of a vehicle, where a strain rate-dependent model of its components is required. In this paper, an elasto-viscoplastic modeling procedure of the polymer-based nanocomposites, assuming the elastic behavior of the nano-phase is presented; whereas the polymeric matrix deformation is dependent to the loading rate and is characterized by the method of Genetic algorithm optimization-based fitting to the experimental observations. By introducing a modified Halpin-Tsai method, the nanocomposite is then modeled as a homogenized material where the modification algorithm is the main challenge. A combination of approaches including parametric analysis, central composite design of experiments and response surface method is proposed to modify the tangent modulus of the polymeric matrix to be passed as the input to the Halpin-Tsai equations. Finally, the procedure is implemented to a set of epoxy-GNP nanocomposites under unidirectional compressive loads with different rates and the stress-strain curves are predicted with a decent precision.

scholarly journals Review of the relationship between aggregates geology and Los Angeles and micro-Deval tests

2021 ◽  
Vol 80 (3) ◽  
pp. 1963-1980
Author(s):  
Solomon Adomako ◽  
Christian John Engelsen ◽  
Rein Terje Thorstensen ◽  
Diego Maria Barbieri
Keyword(s):  
Los Angeles ◽  
Crystal Size ◽  
Grain Shape ◽  
Mechanical Performance ◽  
Pore Space ◽  
Construction Material ◽  
Engineering Properties ◽  
Coarse Grained ◽  
The Impact ◽  
The Relationship

AbstractRock aggregates constitute the enormous volume of inert construction material used around the globe. The petrologic description as igneous, sedimentary, and metamorphic types establishes the intrinsic formation pattern of the parent rock. The engineering properties of these rocks vary due to the differences in the transformation process (e.g. hydrothermal deposits) and weathering effect. The two most common mechanical tests used to investigate the performance of aggregates are the Los Angeles (LA) and micro-Deval (MD) tests. This study reviewed the geological parameters (including mineralogy, grain and crystal size, grain shape, and porosity) and the relationship to Los Angeles and micro-Deval tests. It was found that high content of primary minerals in rocks (e.g. quartz and feldspar) is a significant parameter for performance evaluation. Traces of secondary and accessory minerals also affect the performance of rocks, although in many cases it is based on the percentage. Furthermore, some studies showed that the effect of mineralogic composition on mechanical strength is not sufficient to draw final conclusions of mechanical performance; therefore, the impact of other textural characteristics should be considered. The disposition of grain size and crystal size (e.g. as result of lithification) showed that rocks composed of fine-grain textural composition of ≤ 1 mm enhanced fragmentation and wear resistance than medium and coarse grained (≥ 1 mm). The effect of grain shape was based on convex and concave shapes and flat and elongated apexes of tested samples. The equidimensional form descriptor of rocks somehow improved resistance to impact from LA than highly flat and elongated particles. Lastly, the distribution of pore space investigated by means of the saturation method mostly showed moderate (R = 0.50) to strong (R = 0.90) and positive correlations to LA and MD tests.

scholarly journals A Hybrid Energy System Workflow for Energy Portfolio Optimization

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4392
Author(s):  
Jia Zhou ◽  
Hany Abdel-Khalik ◽  
Paul Talbot ◽  
Cristian Rabiti
Keyword(s):  
Time Series ◽  
Gaussian Process ◽  
Electricity Market ◽  
Process Model ◽  
Net Present Value ◽  
Historical Data ◽  
Energy System ◽  
Initial Guess ◽  
Reduced Order ◽  
The Impact

This manuscript develops a workflow, driven by data analytics algorithms, to support the optimization of the economic performance of an Integrated Energy System. The goal is to determine the optimum mix of capacities from a set of different energy producers (e.g., nuclear, gas, wind and solar). A stochastic-based optimizer is employed, based on Gaussian Process Modeling, which requires numerous samples for its training. Each sample represents a time series describing the demand, load, or other operational and economic profiles for various types of energy producers. These samples are synthetically generated using a reduced order modeling algorithm that reads a limited set of historical data, such as demand and load data from past years. Numerous data analysis methods are employed to construct the reduced order models, including, for example, the Auto Regressive Moving Average, Fourier series decomposition, and the peak detection algorithm. All these algorithms are designed to detrend the data and extract features that can be employed to generate synthetic time histories that preserve the statistical properties of the original limited historical data. The optimization cost function is based on an economic model that assesses the effective cost of energy based on two figures of merit: the specific cash flow stream for each energy producer and the total Net Present Value. An initial guess for the optimal capacities is obtained using the screening curve method. The results of the Gaussian Process model-based optimization are assessed using an exhaustive Monte Carlo search, with the results indicating reasonable optimization results. The workflow has been implemented inside the Idaho National Laboratory’s Risk Analysis and Virtual Environment (RAVEN) framework. The main contribution of this study addresses several challenges in the current optimization methods of the energy portfolios in IES: First, the feasibility of generating the synthetic time series of the periodic peak data; Second, the computational burden of the conventional stochastic optimization of the energy portfolio, associated with the need for repeated executions of system models; Third, the inadequacies of previous studies in terms of the comparisons of the impact of the economic parameters. The proposed workflow can provide a scientifically defendable strategy to support decision-making in the electricity market and to help energy distributors develop a better understanding of the performance of integrated energy systems.

scholarly journals Assessing inequality, irregularity, and severity regarding road traffic safety during COVID-19

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lei Lin ◽  
Feng Shi ◽  
Weizi Li
Keyword(s):  
New York ◽  
Los Angeles ◽  
Traffic Safety ◽  
Traffic Accidents ◽  
Road Traffic ◽  
Human Mobility ◽  
Critical Conditions ◽  
Road Traffic Safety ◽  
Accident Data ◽  
The Impact

AbstractCOVID-19 has affected every sector of our society, among which human mobility is taking a dramatic change due to quarantine and social distancing. We investigate the impact of the pandemic and subsequent mobility changes on road traffic safety. Using traffic accident data from the city of Los Angeles and New York City, we find that the impact is not merely a blunt reduction in traffic and accidents; rather, (1) the proportion of accidents unexpectedly increases for “Hispanic” and “Male” groups; (2) the “hot spots” of accidents have shifted in both time and space and are likely moved from higher-income areas (e.g., Hollywood and Lower Manhattan) to lower-income areas (e.g., southern LA and southern Brooklyn); (3) the severity level of accidents decreases with the number of accidents regardless of transportation modes. Understanding those variations of traffic accidents not only sheds a light on the heterogeneous impact of COVID-19 across demographic and geographic factors, but also helps policymakers and planners design more effective safety policies and interventions during critical conditions such as the pandemic.

scholarly journals When is a Match Sufficient? A Score-based Balance Metric for the Synthetic Control Method

2020 ◽  
Vol 8 (1) ◽  
pp. 209-228
Author(s):  
Layla Parast ◽  
Priscillia Hunt ◽  
Beth Ann Griffin ◽  
David Powell
Keyword(s):  
Los Angeles ◽  
Control Method ◽  
Control Unit ◽  
Treated Group ◽  
Control Group ◽  
Synthetic Control ◽  
Donor Pool ◽  
Synthetic Control Method ◽  
The Mean ◽  
The Impact

AbstractIn some applications, researchers using the synthetic control method (SCM) to evaluate the effect of a policy may struggle to determine whether they have identified a “good match” between the control group and treated group. In this paper, we demonstrate the utility of the mean and maximum Absolute Standardized Mean Difference (ASMD) as a test of balance between a synthetic control unit and treated unit, and provide guidance on what constitutes a poor fit when using a synthetic control. We explore and compare other potential metrics using a simulation study. We provide an application of our proposed balance metric to the 2013 Los Angeles (LA) Firearm Study [9]. Using Uniform Crime Report data, we apply the SCM to obtain a counterfactual for the LA firearm-related crime rate based on a weighted combination of control units in a donor pool of cities. We use this counterfactual to estimate the effect of the LA Firearm Study intervention and explore the impact of changing the donor pool and pre-intervention duration period on resulting matches and estimated effects. We demonstrate how decision-making about the quality of a synthetic control can be improved by using ASMD. The mean and max ASMD clearly differentiate between poor matches and good matches. Researchers need better guidance on what is a meaningful imbalance between synthetic control and treated groups. In addition to the use of gap plots, the proposed balance metric can provide an objective way of determining fit.

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