scholarly journals Structural Analysis in Transit System Using Network Theory Case of Guadalajara, Mexico

Urban Science ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 87
Author(s):  
Orlando Barraza ◽  
Miquel Estrada
Keyword(s):  
Structural Analysis ◽  
Network Theory ◽  
Planning Process ◽  
Structural Features ◽  
Transport Network ◽  
Structural Elements ◽  
Transit System ◽  
Transit Network ◽  
Network Properties ◽  
In Transit

Structural analysis in a transit network is a key aspect used to evaluate in a planning process. In this sense, the use of network science was applied in this work to generate a framework of the main structural features of a transport network. In this case, an alternative transport network in Guadalajara, Mexico was taken as an example. The network properties selected were grade of accessibility, spatial friction, and vulnerability. In the case of the grade of accessibility, this propriety makes reference to the efficiency of the travel time that the network gives due to its structural features. The spatial friction measures how direct in terms of distance the trips that the network provides are, and the vulnerability relates to the ease with which the network can comprise its performance by affectations to their nodes or links. In this sense, this work presents a detailed methodology and a set of open-source tools that can be used to measure these key structural elements for decision making.

Accessibility Scenario Analysis of a Hypothetical Future Transit Network: Social Equity Implications of a General Transit Feed Specification–Based Sketch Planning Tool

2017 ◽  
Vol 2671 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Andrew Guthrie ◽  
Yingling Fan ◽  
Kirti Vardhan Das
Keyword(s):  
Planning Process ◽  
Social Equity ◽  
Social Benefit ◽  
Planning Tool ◽  
Transit Planning ◽  
Transit System ◽  
Transit Systems ◽  
Transit Network ◽  
Accessibility Analysis ◽  
Transit Accessibility

Accessibility analysis can have important implications for understanding social equity in transit planning. The emergence and the increasingly broad acceptance of the general transit feed specification (GTFS) format for transit route, stop, and schedule data have revolutionized transit accessibility research by providing researchers with a convenient, publicly available source of data interoperable with common geographic information system (GIS) software. Existing approaches to GTFS-based transit analysis, however, focus on currently operating transit systems. With major transit expansions across the nation and around the world increasing in number and ambition, understanding the accessibility impacts of proposed projects in their early planning stages is crucial to achieving the greatest possible social benefit from these massive public investments. This paper describes the development of a hypothetical transit network based on current GTFS data and proposed 2040 transit improvements for the Twin Cities region of Minneapolis–Saint Paul, Minnesota, as well as its use as a sketch planning tool in exploring the proposed system’s impacts on access to job vacancies from historically disadvantaged areas. This research demonstrates the importance of accessibility analysis in planning a transit system that increases opportunity for marginalized workers and concludes by calling for broader, easier access to accessibility analysis for practitioners and community groups to refine the early stages of the transit planning process and democratize an increasingly crucial transit planning tool.

scholarly journals Comparative Measures for Transit Network Performance Analysis

2012 ◽  
Vol 47 (3) ◽  
Author(s):  
Young-Jae Lee
Keyword(s):  
Network Performance ◽  
Weighted Average ◽  
Comparative Approach ◽  
Transit Planning ◽  
Transit System ◽  
Transit Network ◽  
Transportation Modes ◽  
Two Measures ◽  
In Transit ◽  
Simple Average

This paper discusses existing measures for the analysis of transit network performance and develops new measures that use a comparative approach to examine the efficiency of transit network configuration. Most measures in transit planning and operating are estimated by the transit system itself, but because transit competes with other transportation modes, comparative measures are necessary to attract more transit riders. This paper introduces two measures: the Degree of Competitiveness and the Degree of Circuity. While these measures examine performance for each zone-to-zone travel, simple average and weighted average are also introduced to evaluate the entire transit network.

Transit Network Design: The Necessity of Elastic Demand Consideration

2011 ◽  
Vol 97-98 ◽  
pp. 1117-1122 ◽  
Author(s):  
Andisheh Ranjbari ◽  
Afshin Shariat Mohaymany ◽  
S. M. Mahdi Amiripour
Keyword(s):  
Network Design ◽  
Public Transportation ◽  
Supply And Demand ◽  
Network Design Problem ◽  
Elastic Demand ◽  
Transit System ◽  
Transit Network ◽  
Optimal Network ◽  
Transit Network Design ◽  
In Transit

Transit network design as the first and critical phase of public transportation planning is extremely sensitive to transit demand. An important characteristic of transit demand is elasticity or service-dependency, which means that any change in the service offered by the system is followed by a change in transit demand. Due to the complexity of transit network design problem (TNDP) researchers have usually assumed transit demand to be fixed rather than elastic; while ignoring this issue may result in inefficiency of system, dissatisfaction of users, and system failure, since the predicted amount of passengers would not use the transit system. This paper aims to demonstrate the necessity of elastic demand consideration in transit network design, and proposes a solution framework, which is composed of a preparation stage and an iterative procedure. A case study example is presented subsequently, to show the use of this solution method and further illustrates the necessity of considering this issue. Three cases of truly predicted demand (considering elastic demand), overestimated and underestimated demands (in the absence of elastic demand consideration) are defined, and the performance measures of these cases are compared to those in the base mode. The results show that elastic demand consideration leads to the optimal network, in which the system efficiently matches between supply and demand.

scholarly journals Bus Transit Network Structure Selection With Multiple Objectives

2021 ◽  
Vol 12 (4) ◽  
pp. 1-13
Author(s):  
K. Ramacandra Rao ◽  
Subhro Mitra ◽  
Joseph Szmerekovsky
Keyword(s):  
Network Structure ◽  
Public Transportation ◽  
Rational Design ◽  
Ad Hoc ◽  
Planning Process ◽  
Transit System ◽  
Transit Network ◽  
Structure Selection ◽  
Bus Transit ◽  
Bus Transportation

Bus transportation is the essential mode of public transportation available for intra-district movements in India. The planning of different stages of bus transportation planning is usually done in an ad-hoc manner on the basis of the experience of the operators. For a rational design of the bus transit system, it is essential to take into account the objectives of different interest groups. Selection of an appropriate network structure is an essential part of the planning process. In this paper, a model developed for generating a number of alternative network structures using link deletion concept is presented. One of these alternatives can be selected on the basis of the trade-off between the user and operator objectives. The model has been applied to a case study of bus transit network of Visakhapatnam region in Andhra Pradesh.

Influence of the distribution of the shear walls on the seismic response of the buildings

2020 ◽  
Vol 15 (1) ◽  
pp. 37-44
Author(s):  
El Mehdi Echebba ◽  
Hasnae Boubel ◽  
Oumnia Elmrabet ◽  
Mohamed Rougui
Keyword(s):  
Structural Analysis ◽  
Seismic Response ◽  
Natural Frequency ◽  
Structural Design ◽  
Structural Response ◽  
Shear Walls ◽  
Structural Elements ◽  
Analysis Software ◽  
Ansys Apdl ◽  
The Impact

Abstract In this paper, an evaluation was tried for the impact of structural design on structural response. Several situations are foreseen as the possibilities of changing the distribution of the structural elements (sails, columns, etc.), the width of the structure and the number of floors indicates the adapted type of bracing for a given structure by referring only to its Geometric dimensions. This was done by studying the effect of the technical design of the building on the natural frequency of the structure with the study of the influence of the distribution of the structural elements on the seismic response of the building, taking into account of the requirements of the Moroccan earthquake regulations 2000/2011 and using the ANSYS APDL and Robot Structural Analysis software.

scholarly journals Repression and Derepression of Minus-Strand Synthesis in a Plus-Strand RNA Virus Replicon

2004 ◽  
Vol 78 (14) ◽  
pp. 7619-7633 ◽  
Author(s):  
Guohua Zhang ◽  
Jiuchun Zhang ◽  
Anne E. Simon
Keyword(s):  
Solution Structure ◽  
Rna Virus ◽  
Structural Features ◽  
General Mechanism ◽  
Minus Strand ◽  
Turnip Crinkle Virus ◽  
Structural Elements ◽  
Transcription In Vitro

ABSTRACT Plus-strand viral RNAs contain sequences and structural elements that allow cognate RNA-dependent RNA polymerases (RdRp) to correctly initiate and transcribe asymmetric levels of plus and minus strands during RNA replication. cis-acting sequences involved in minus-strand synthesis, including promoters, enhancers, and, recently, transcriptional repressors (J. Pogany, M. R. Fabian, K. A. White, and P. D. Nagy, EMBO J. 22:5602-5611, 2003), have been identified for many viruses. A second example of a transcriptional repressor has been discovered in satC, a replicon associated with turnip crinkle virus. satC hairpin 5 (H5), located proximal to the core hairpin promoter, contains a large symmetrical internal loop (LSL) with sequence complementary to 3′-terminal bases. Deletion of satC 3′-terminal bases or alteration of the putative interacting bases enhanced transcription in vitro, while compensatory exchanges between the LSL and 3′ end restored near-normal transcription. Solution structure analysis indicated that substantial alteration of the satC H5 region occurs when the three 3′-terminal cytidylates are deleted. These results indicate that H5 functions to suppress synthesis of minus strands by sequestering the 3′ terminus from the RdRp. Alteration of a second sequence strongly repressed transcription in vitro and accumulation in vivo, suggesting that this sequence may function as a derepressor to free the 3′ end from interaction with H5. Hairpins with similar sequence and/or structural features that contain sequence complementary to 3′-terminal bases, as well as sequences that could function as derepressors, are located in similar regions in other carmoviruses, suggesting a general mechanism for controlling minus-strand synthesis in the genus.

scholarly journals Structural Analysis and Design of Structural Elements of A Building

2018 ◽  
Vol Volume-2 (Issue-3) ◽  
pp. 1132-1151
Author(s):  
Potharaboyena Vinay ◽  
Kurimilla Srilaxmi ◽  
Keyword(s):  
Structural Analysis ◽  
Structural Elements ◽  
Analysis And Design

Chondroitin sulfate and cytoplasmic domain-dependent membrane targeting of the NG2 proteoglycan promotes retraction fiber formation and cell polarization

2001 ◽  
Vol 114 (12) ◽  
pp. 2315-2325 ◽  
Author(s):  
William B. Stallcup ◽  
Kimberlee Dahlin-Huppe
Keyword(s):  
Chondroitin Sulfate ◽  
Rho Gtpase ◽  
Cytoplasmic Domain ◽  
Structural Features ◽  
Cell Polarization ◽  
Fiber Formation ◽  
Structural Elements ◽  
Motile Cells ◽  
Chondroitin Sulfate Chain ◽  
Ng2 Proteoglycan

Targeting of the NG2 proteoglycan to cellular retraction fibers was studied by expressing mutant NG2 molecules lacking specific structural elements of the proteoglycan. Both the cytoplasmic domain and the chondroitin sulfate chain of NG2 appear to have roles in sorting NG2 to subcellular microdomains destined to become retraction fibers. Neither of these structural features alone is sufficient to allow optimal targeting of NG2 to retraction fibers, but together they promote efficient localization of the proteoglycan to these sites. This pattern of NG2 sorting seems to be necessary for optimal retraction fiber formation, as cells expressing poorly targeted NG2 mutants are noticeably deficient in their ability to extend retraction fibers. Furthermore, retraction fiber formation correlates strongly with the tendency of cells to assume a polarized morphology with NG2-positive retraction fibers at one pole of the cell and actin-rich lamellipodia at the other. This polarization can be triggered either through engagement of NG2 by the substratum or by exposure to lysophosphatidic acid, a potent activator of the rho GTPase. These results suggest a possible role for NG2 in regulating rho-dependent mechanisms in the trailing processes of motile cells.

Geology, Structural Analysis, and Paragenesis of the Arrow Uranium Deposit, Western Athabasca Basin, Saskatchewan, Canada: Implications for the Development of the Patterson Lake Corridor

2020 ◽  
Author(s):  
Sean Hillacre ◽  
Kevin Ansdell ◽  
Brian McEwan
Keyword(s):  
Structural Analysis ◽  
Uranium Deposit ◽  
Regional Scale ◽  
Structural Features ◽  
White Mica ◽  
Uranium Mineralization ◽  
Fault System ◽  
Thin Sections ◽  
Athabasca Basin ◽  
Quartz Veins

Abstract Recent significant discoveries of uranium mineralization in the southwestern Athabasca basin, northern Saskatchewan, Canada, have been associated with a series of geophysical conductors along a NE- to SW-trending structural zone, termed the Patterson Lake corridor. The Arrow deposit (indicated mineral resource: 256.6 Mlb U3O8; grade 4.03% U3O8) is along this trend, hosted exclusively in basement orthogneisses of the Taltson domain, and is the largest undeveloped uranium deposit in the basin. This study is the first detailed analysis of a deposit along this corridor and examines the relationships between the ductile framework and brittle reactivation of structures, mineral paragenesis, and uranium mineralization. Paragenetic information from hundreds of drill core samples and thin sections was integrated with structural analysis utilizing over 18,000 measurements of various structural features. The structural system at Arrow is interpreted as a partitioned, strike-slip–dominated, brittle-ductile fault system of complex Riedel-style geometry. The system developed along subvertical, NE- to SW-trending dextral high-strain zones formed syn- to post-D3 deformation, which were the focus of extensive premineralization metasomatism (quartz flooding, sericitization, chloritization), within the limb domain of a regional-scale fold structure. These zones evolved through post-Athabasca dextral and sinistral reactivation events, creating brittle fault linkages and dilation zones, allowing for hydrothermal fluid migration and resulting uraninite precipitation and associated alteration (white mica, chlorite, kaolinite, hematite, quartz veins). This study of the structural context of Arrow is important as it emphasizes that protracted reactivation of deep-seated structures and their subsidiaries was a fundamental control on uranium mineralization in the southwestern Athabasca basin.

Aspect structural du Medoc atlantique

1960 ◽  
Vol S7-II (6) ◽  
pp. 796-800
Author(s):  
Michelle Caralp ◽  
M. Vigneaux
Keyword(s):  
Atlantic Coast ◽  
River Mouth ◽  
Structural Features ◽  
Structural Elements

Abstract Data from some 10 boreholes in the area south of the Gironde river mouth on the Atlantic coast of France show that there are three main structural elements below the Quaternary cover. From north to south, these are the Hourtin syncline, the faulted Carcans anticline, and the block-faulted section south of Carcans. These structural features controlled Tertiary deposition and, in particular, explain the lateral facies variations of Miocene formations.

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