scholarly journals Accessibility Toolbox for R and ArcGIS

10.32866/8416 ◽  
2019 ◽  
Author(s):  
Christopher D. Higgins
Keyword(s):  
Impedance Function ◽  
Accessibility Analysis ◽  
Analysis Workflow ◽  
Travel Impedance ◽  
Study Context ◽  
Impedance Functions ◽  
Selection Of

Analyses of place-based accessibility undertaken in the popular ArcGIS environment require many time-consuming and tedious steps. Moreover, questions persist over the selection of an impedance function and cost or cut-off parameters. In response, this paper details a new Accessibility Toolbox for R and ArcGIS that includes a Python tool for conducting accessibility analyses and an interactive R Notebook that enables the visualization and customization of impedance functions and parameters. Using this toolbox, researchers and practitioners can simplify their accessibility analysis workflow and make better decisions about the specification and customization of travel impedance for their study context.

Research on Improvement Road Impedance Function Based on Vehicle Navigation System

2013 ◽  
Vol 659 ◽  
pp. 45-48
Author(s):  
Rui Wang ◽  
Zai Tang Wang
Keyword(s):  
Path Planning ◽  
Navigation System ◽  
Vehicle Navigation ◽  
Impedance Function ◽  
Vehicle Navigation System ◽  
Navigation Path ◽  
Planning Algorithm ◽  
Improved Model ◽  
Path Planning Algorithm ◽  
Impedance Functions

Comparing with some widely used road impedance functions, this paper choose BPR model as base model of improvement, and determine the parameter of BPR model. We apply the improved model to vehicle navigation system in the path planning algorithm, and experiments proved that the model satisfies navigation path planning requirement and have universal performance.

Bound estimates for the derivative of driving point impedance functions

Filomat ◽  
2018 ◽  
Vol 32 (18) ◽  
pp. 6211-6218 ◽  
Author(s):  
Bülent Örnek ◽  
Timur Düzenlı
Keyword(s):  
Analytic Function ◽  
Boundary Point ◽  
Imaginary Axis ◽  
Proved Theorem ◽  
Impedance Function ◽  
Boundary Analysis ◽  
Natural Result ◽  
The Right ◽  
Rlc Circuits ◽  
Impedance Functions

In this paper, a boundary analysis is carried out for the derivative of driving point impedance functions, which is mainly used for synthesis of networks containing RL, RC and RLC circuits. It is known that driving point impedance function, Z(s), is an analytic function defined on the right half of the s-plane. In this study, we derive inequalities for the modulus of derivative of driving point impedance function, |Z'(0)|, by assuming the Z(s) function is also analytic at the boundary point s = 0 on the imaginary axis and the sharpness of these inequalities is proved. Furthermore, an equation for the driving point impedance function, Z(s), is obtained as a natural result of the proved theorem in this study.

An Investigation of Soil-Structure Interaction Effects Observed at the MIT Green Building

2016 ◽  
Vol 32 (4) ◽  
pp. 2425-2448 ◽  
Author(s):  
Ertugrul Taciroglu ◽  
Mehmet Çelebi ◽  
S. Farid Ghahari ◽  
Fariba Abazarsa
Keyword(s):  
Soil Structure ◽  
Transfer Functions ◽  
Green Building ◽  
Modal Identification ◽  
Beam Model ◽  
Impedance Function ◽  
Frequency Dependent ◽  
Flexible Base ◽  
Soil Foundation ◽  
Impedance Functions

The soil-foundation impedance function of the MIT Green Building is identified from its response signals recorded during an earthquake. Estimation of foundation impedance functions from seismic response signals is a challenging task, because: (1) the foundation input motions (FIMs) are not directly measurable, (2) the as-built properties of the super-structure are only approximately known, and (3) the soil-foundation impedance functions are inherently frequency-dependent. In the present study, aforementioned difficulties are circumvented by using, in succession, a blind modal identification (BMID) method, a simplified Timoshenko beam model (TBM), and a parametric updating of transfer functions (TFs). First, the flexible-base modal properties of the building are identified from response signals using the BMID method. Then, a flexible-base TBM is updated using the identified modal data. Finally, the frequency-dependent soil-foundation impedance function is estimated by minimizing the discrepancy between TFs (of pairs instrumented floors) that are (1) obtained experimentally from earthquake data and (2) analytically from the updated TBM. Using the fully identified flexible-base TBM, the FIMs as well as building responses at locations without instruments can be predicted, as demonstrated in the present study.

scholarly journals Insights into the Ligand Binding to Bromodomain-Containing Protein 9 (BRD9): A Guide to the Selection of Potential Binders by Computational Methods

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7192
Author(s):  
Simona De Vita ◽  
Maria Giovanna Chini ◽  
Giuseppe Bifulco ◽  
Gianluigi Lauro
Keyword(s):  
Molecular Dynamics ◽  
Molecular Docking ◽  
Binding Affinities ◽  
Residue Interaction ◽  
Balance Accuracy ◽  
Explicit Solvent ◽  
Analysis Workflow ◽  
Biological Tests ◽  
Dynamics Simulations ◽  
Selection Of

The estimation of the binding of a set of molecules against BRD9 protein was carried out through an in silico molecular dynamics-driven exhaustive analysis to guide the identification of potential novel ligands. Starting from eight crystal structures of this protein co-complexed with known binders and one apo form, we conducted an exhaustive molecular docking/molecular dynamics (MD) investigation. To balance accuracy and an affordable calculation time, the systems were simulated for 100 ns in explicit solvent. Moreover, one complex was simulated for 1 µs to assess the influence of simulation time on the results. A set of MD-derived parameters was computed and compared with molecular docking-derived and experimental data. MM-GBSA and the per-residue interaction energy emerged as the main indicators for the good interaction between the specific binder and the protein counterpart. To assess the performance of the proposed analysis workflow, we tested six molecules featuring different binding affinities for BRD9, obtaining promising outcomes. Further insights were reported to highlight the influence of the starting structure on the molecular dynamics simulations evolution. The data confirmed that a ranking of BRD9 binders using key parameters arising from molecular dynamics is advisable to discard poor ligands before moving on with the synthesis and the biological tests.

Application of theories in CSR research focusing study context and corporate attributes

2020 ◽  
Vol 36 (3) ◽  
pp. 305-324
Author(s):  
Sohel Mehedi ◽  
Dayana Jalaludin
Keyword(s):  
Literature Review ◽  
Voluntary Disclosure ◽  
English Language ◽  
Exogenous Variables ◽  
Strong Basis ◽  
Content Type ◽  
Corporate Social ◽  
Study Context ◽  
Csr Engagement ◽  
Selection Of

Purpose The purpose of this paper is to review the background of the theories, how they motivate corporations to engage in corporate social responsibility (CSR) activities and their application, focusing on the study context and corporate attributes. Design/methodology/approach The study used Google Scholar as an online database and collected 170 published academic papers via a systematic search procedure; of these, 112 papers were selected as suitable for the study purpose. The selection followed the analysis of the abstract, the paper contents including the proposition of the theories, the literature review, the theoretical framework and the hypothesis development. Findings The study findings indicate that the cores of the proposed theories to explore CSR are not identical. The components of theories build a social value system, which intensely motivates corporations to engage in CSR activities and voluntary disclosure practices. A thorough analysis of the characteristics of the theories demonstrates that the choice of theories to explore both an endogenous variable like CSR and exogenous variables depends on the study context and the characteristics of the corporate attributes. Research limitations/implications The study considers only the most prominent theories in CSR research, but many other theories are also explored in CSR research. In addition, the study takes only academic papers in the English language into consideration, and the generalization of study findings is only for CSR research. Practical implications The study aims to provide guidance about the selection of theories based on the contexts and corporate attributes to explore both endogenous and exogenous variables. It draws policymakers’ attention toward the renovation and addition of motivational instruments in the context. The study also helps industry practitioners in realizing the principles and consequences of the theories and in taking strategic social and environmental obligations into consideration in their decision-making process. Originality/value This is the first attempt to conduct a literature review on the development of theories and corporate CSR engagement from 1975 to 2019, covering 112 published academic papers. A deeper understanding using theoretical conceptualization as guidance is beneficial, as it provides a strong basis for the enhancement of future CSR corporate activities.

A mixed-mode traffic assignment model with new time-flow impedance function

2018 ◽  
Vol 32 (03) ◽  
pp. 1850017 ◽  
Author(s):  
Gui-Hua Lin ◽  
Yu Hu ◽  
Yuan-Yang Zou
Keyword(s):  
Electric Vehicles ◽  
Mixed Mode ◽  
Transportation Network ◽  
Operating Cost ◽  
Impedance Function ◽  
Sqp Algorithm ◽  
Time Flow ◽  
Flow Impedance ◽  
Impedance Functions ◽  
New Time

Recently, with the wide adoption of electric vehicles, transportation network has shown different characteristics and been further developed. In this paper, we present a new time-flow impedance function, which may be more realistic than the existing time-flow impedance functions. Based on this new impedance function, we present an optimization model for a mixed-mode traffic network in which battery electric vehicles (BEVs) and gasoline vehicles (GVs) are chosen. We suggest two approaches to handle the model: One is to use the interior point (IP) algorithm and the other is to employ the sequential quadratic programming (SQP) algorithm. Three numerical examples are presented to illustrate the efficiency of these approaches. In particular, our numerical results show that more travelers prefer to choosing BEVs when the distance limit of BEVs is long enough and the unit operating cost of GVs is higher than that of BEVs, and the SQP algorithm is faster than the IP algorithm.

The influence of the impedance function on gravity-based pedestrian accessibility measures: A comparative analysis

2016 ◽  
Vol 44 (4) ◽  
pp. 740-763 ◽  
Author(s):  
David S Vale ◽  
Mauro Pereira
Keyword(s):  
Factor Analysis ◽  
Comparative Analysis ◽  
Spatial Analysis ◽  
Correlation Analysis ◽  
Spatial Data ◽  
Impedance Function ◽  
Data Variability ◽  
Planning Objective ◽  
Selection Of ◽  
Pedestrian Accessibility

Pedestrian accessibility has been growing in importance as an urban planning objective. Assessing it with gravity-based or potential accessibility measures requires the selection of an impedance function in order to reflect the friction of distance. The choice of impedance function is crucial to pedestrian accessibility assessment due to the level of spatial data detail required and also because perceived distances differ from physical distances. Here, we measure and compare 20 gravity-based measures, varying the impedance function and associated parameters. Correlation analysis revealed a significant and strong correlation between the measures. Factor analysis extracted two groups of measures, differing mainly in their maximum cutoff travel distance, i.e. the distance at which the impedance function reaches zero. Spatial analysis revealed that all measures produce similar spatial results in terms of identifying high and low accessibility locations but different values for medium accessibility locations. Places located at between 200 and 400 m from an opportunity are especially sensitive to the impedance function used. We promote a cumulative–Gaussian approach to measure pedestrian accessibility, as it explicitly includes the travel tolerance concept and we found it to be the most robust measure in terms of data variability.

scholarly journals An interactive web-based application for Comprehensive Analysis of RNAi-screen Data

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Bhaskar Dutta ◽  
Alaleh Azhir ◽  
Louis-Henri Merino ◽  
Yongjian Guo ◽  
Swetha Revanur ◽  
...  
Keyword(s):  
Comprehensive Analysis ◽  
Rnai Screen ◽  
Integrated Analysis ◽  
Expression Data ◽  
Web Based ◽  
Optimal Thresholds ◽  
Analysis Workflow ◽  
Genome Scale ◽  
Sirna Screens ◽  
Selection Of

Abstract RNAi screens are widely used in functional genomics. Although the screen data can be susceptible to a number of experimental biases, many of these can be corrected by computational analysis. For this purpose, here we have developed a web-based platform for integrated analysis and visualization of RNAi screen data named CARD (for Comprehensive Analysis of RNAi Data; available at https://card.niaid.nih.gov). CARD allows the user to seamlessly carry out sequential steps in a rigorous data analysis workflow, including normalization, off-target analysis, integration of gene expression data, optimal thresholds for hit selection and network/pathway analysis. To evaluate the utility of CARD, we describe analysis of three genome-scale siRNA screens and demonstrate: (i) a significant increase both in selection of subsequently validated hits and in rejection of false positives, (ii) an increased overlap of hits from independent screens of the same biology and (iii) insight to microRNA (miRNA) activity based on siRNA seed enrichment.

Association of electronic-health record (EHR)-derived race with BRCA testing in patients (pts) with breast cancer (BC) with similar genetic ancestry (GA) in a clinicogenomic database (CGDB).

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 6524-6524
Author(s):  
Yanling Jin ◽  
Charlotta Fruchtenicht ◽  
Sylvia Hu ◽  
Janis Allen ◽  
Anne-Marie Meyer ◽  
...  
Keyword(s):  
Health Disparities ◽  
Sample Size ◽  
South Asian ◽  
Racial Disparity ◽  
Brca Testing ◽  
Analysis Workflow ◽  
Comprehensive Genomic Profiling ◽  
Testing Patterns ◽  
Increase Sample Size ◽  
Selection Of

6524 Background: Disparities in health outcomes can be affected by biological factors associated with GA and social determinants of health. These factors can be teased apart using GA data from comprehensive genomic profiling (CGP) in pts with cancer. CGDBs that link EHR data with CGP enable the selection of pts with similar GA. Holding GA constant provides an opportunity to directly study the effects of reported race in health disparities. This study evaluated a published racial disparity (BRCA testing rates in African American [AA] vs White pts with BC) in a population with fixed, similar GA. Methods: The nationwide (US-based) deidentified Flatiron Health and Foundation Medicine (FMI) BC CGDB (Q3 2020) was used. For each pt, GA fractions from 5 geographic ancestry groups (African [AFR]; Admixed American; East Asian; European [EUR]; South Asian) were derived by FMI using an admixture analysis workflow using genes captured in the CGP assay. To focus on BRCA testing in AA vs White pts and find a sufficient population with similar GA but AA or White race, pts with admixture of both EUR and AFR ancestry were selected. The chosen fractions were: Cohort 1=35%-65% AFR and EUR each; Cohort 2=25%-60% AFR and EUR each; Cohort 3=30%-60% AFR. Cohorts overlap but were chosen to increase sample size. In each cohort, documented BRCA testing prevalence, time from diagnosis to BRCA test date, age at BRCA test and overall survival (OS) were compared between races. Other race (OR) and missing race (MR) were also reported. Results: Most pts (4130/6903) in the BC CGDB had ≥75% EUR ancestry; 129 pts had AFR ancestry fractions ≥25% with EUR ancestry >0%. AA pts had the lowest BRCA testing rates (39%, 43%, 44% for Cohorts 1-3, respectively), which were 18%, 10% and 17% lower compared with White pts, respectively (Table). In Cohorts 1-3, AA pts experienced a longer median time between diagnosis and testing (399, 668, 900 days) compared with White pts (93, 667, 106 days). The median age at BRCA test was 16, 9 and 8 years younger in AA pts (49, 47 and 50 years) compared with White pts. Although pts with MR data had the lowest OS compared with the other races within each cohort, the sample size of each arm for all cohorts was too small to make conclusions. Conclusions: This study demonstrated that when holding GA constant, racial disparities persist in BRCA testing patterns and outcome in pts with BC from a CGDB. With increasing availability of linked clinical and genomic data, further exploration of disparities in genetically similar cohorts can provide deeper insight for cancer outcomes and health disparities research.[Table: see text]

Dynamic Response of Different Types of Shallow Foundation over Sandy Soils to Horizontal Harmonic Loading

2015 ◽  
Vol 6 (1) ◽  
pp. 1-14
Author(s):  
Taha Ashoori ◽  
Keivan Pakiman
Keyword(s):  
Dynamic Response ◽  
Finite Thickness ◽  
Shallow Foundation ◽  
Width Ratio ◽  
Dynamic Force ◽  
Impedance Function ◽  
Dynamic Impedance ◽  
Length Width ◽  
Soil Foundation ◽  
Impedance Functions

Increasing requirements of industries and research institutes to analytically results of interaction soil-foundation related systems, reveals the importance of the dynamic impedance functions than ever before. The dynamic impedance function relations are presented for mass less rigid foundations which is possible to obtain dynamic response of foundations for different frequencies and masses accordingly. In this study, the dynamic impedance functions were investigated using physical modeling tests on sandy soil with finite thickness soil stratum over bedrock. The tests were carried out inside a steel container of dimensions 1×1×0.8m in length, width and height respectively which was filled into container with Babolsar sand by using air – pluviation technique after calibration test with relative density of 55.1 percent. The selected foundations were square and circular with same surface area and rectangular with length to width ratio of 2 that were investigated to determine effects of shape, inertia, embedment ratio, dynamic force amplitude and bedrock on horizontal impedance.

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