IMPROVED BOUNDS FOR GOSSIPING IN MESH BUS NETWORKS

2000 ◽  
Vol 01 (01) ◽  
pp. 1-19
Author(s):  
JEAN-CLAUDE BERMOND ◽  
SUSAN MARSHALL ◽  
MIN-LI YU
Keyword(s):  
Arbitrary Dimension ◽  
Minimum Number ◽  
One Step ◽  
Bus Network ◽  
Bus Networks

Improved bounds for the minimum gossiping time in mesh bus networks of arbitrary dimension for 1-port model are given. More precisely, the gossiping protocol consists of steps during which messages are sent via buses and at the end of the protocol, all the nodes should know all the information. Furthermore, during one step a bus can carry at most one message, and each node can either send or receive (not both) on at most one bus The minimum gossiping time of a bus network G is the minimum number of steps required to perform a gossip under this model. Here we determine almost exactly the minimum gossip time for 2-dimensional mesh bus networks and give tight bounds for d-dimensional mesh bus networks.

Using GTFS to Calculate Travel Time Savings Potential of Bus Preferential Treatments

2021 ◽  
pp. 036119812110092
Author(s):  
Daniel Arias ◽  
Kara Todd ◽  
Jennifer Krieger ◽  
Spencer Maddox ◽  
Pearse Haley ◽  
...  
Keyword(s):  
Travel Time ◽  
Planning Process ◽  
Operating Cost ◽  
Flow Characteristics ◽  
Travel Time Savings ◽  
Bus Lane ◽  
Time Savings ◽  
Bus Network ◽  
Bus Networks ◽  
Transit Agencies

Dedicated bus lanes and other transit priority treatments are a cost-effective way to improve transit speed and reliability. However, creating a bus lane can be a contentious process; it requires justification to the public and frequently entails competition for federal grants. In addition, more complex bus networks are likely to have unknown locations where transit priority infrastructure would provide high value to riders. This analysis presents a methodology for estimating the value of bus preferential treatments for all segments of a given bus network. It calculates the passenger-weighted travel time savings potential for each inter-stop segment based on schedule padding. The input data, ridership data, and General Transit Feed Specification (GTFS) trip-stop data are universally accessible to transit agencies. This study examines the 2018 Metropolitan Atlanta Rapid Transit Authority (MARTA) bus network and identifies a portion of route 39 on Buford Highway as an example candidate for a bus lane corridor. The results are used to evaluate the value of time savings to passengers, operating cost savings to the agency, and other benefits that would result from implementing bus lanes on Buford Highway. This study does not extend to estimating the cost of transit priority infrastructure or recommending locations based on traffic flow characteristics. However, it does provide a reproducible methodology to estimate the value of transit priority treatments, and it identifies locations with high value, all using data that are readily available to transit agencies. Conducting this analysis provides a foundation for beginning the planning process for transit priority infrastructure.

scholarly journals Restriction of cell lysis by homologous complement: II. Protection of erythrocytes against lysis by newly activated complement

Blood ◽  
1988 ◽  
Vol 71 (2) ◽  
pp. 287-292
Author(s):  
JJ Houle ◽  
EM Hoffmann ◽  
AF Esser
Keyword(s):  
Protective Effect ◽  
Cell Lysis ◽  
Cell Killing ◽  
Complement Proteins ◽  
Minimum Number ◽  
One Step ◽  
High Concentrations ◽  
Heterologous Cell ◽  
Complement Lysis

Our previous work revealed that homologous complement (C) was ineffective in lysing antibody-sensitized erythrocytes (EA) even at high concentrations. It was also shown that activation of complement on homologous EA resulted in the binding of C9 and the formation of EA bearing complement proteins C1 through C9 (EAC1–9), yet few hemolytic sites were formed. Instead, as shown here, the formation of homologous EAC1–9 caused the cells to become resistant to lysis even by heterologous complement during a second incubation. In contrast, when homologous EAC1–8 were produced by incubating EA with C9-depleted serum, such intermediates were not protected against lysis by heterologous complement during a second incubation. Furthermore, homologous C9 on EAC1–9 was able to reduce the hemolytic efficiency of heterologous complement without blocking C activation and the formation of new C5b-9 complexes. Protection was not modified when homologous EAC1–9 were produced in one step, by incubation of EA with serum, or sequentially by adding C9 to EAC1–8. The minimum number of 9-sites required to confer a protective effect on EAC1–9 was less than 200 per cell. Thus, in addition to its known effect in heterologous cell killing, homologous C9 is capable of protecting homologous cells against inadvertent complement lysis.

Solving a second-order algebro-differential equation with respect to the derivative

2021 ◽  
pp. 414-420
Author(s):  
Vladimir I. Uskov
Keyword(s):  
Differential Equation ◽  
Cauchy Problem ◽  
Rigid Body ◽  
Fredholm Operator ◽  
Arbitrary Dimension ◽  
Second Order ◽  
Index Zero ◽  
Second Order Differential Equations ◽  
The Cauchy Problem ◽  
One Step

We consider a second-order algebro-differential equation. Equations and systems of second-order differential equations describe the operation of an electronic triode circuit with feedback, rotation of a rigid body with a cavity, reading information from a disk, etc. The highest derivative is preceded by an irreversible operator. This is a Fredholm operator with index zero, kernel of arbitrary dimension, and Jordan chains of arbitrary lengths. Equations with irreversible operators at the highest derivative are called algebro-differential. In this case, the solution to the problem exists under certain conditions on the components of the desired function. To solve the equation with respect to the derivative, the method of cascade splitting of the equation is used, which consists in the stepwise splitting of the equation into equations in subspaces of decreasing dimensions. Cases of one-step and two-step splitting are considered. The splitting uses the result on the solution of a linear equation with Fredholm operator. In each case, the corresponding result is formulated as a theorem. To illustrate the result obtained in the case of one-step splitting, an illustrative example of the Cauchy problem is given.

scholarly journals Various Constructions of Qudit SWAP Gate

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
S. Balakrishnan
Keyword(s):  
Arbitrary Dimension ◽  
Circuit Complexity ◽  
Quantum Systems ◽  
Swap Gate ◽  
Minimum Number ◽  
Swap Operation

It is known that SWAP operation for quantum systems of arbitrary dimension can be implemented using various qudit gates. In this paper, equivalence of some important qudit operations is demonstrated. Equivalence of the qudit operations is exploited to minimize the circuit complexity in the previously proposed qudit SWAP gate constructions. Further, constructions of qudit SWAP operation with minimum number of qudit gates are also proposed. Importantly, these circuit constructions of SWAP retain its properties like symmetry and simplicity.

Active Node Detection in A Reconfigurable Microgrid using Minimum Spanning Tree Algorithms

2017 ◽  
Vol 5 (3) ◽  
pp. 502 ◽  
Author(s):  
Anay Majee ◽  
Souradeep Nanda ◽  
Gnana Swathika O.V
Keyword(s):  
Renewable Energy ◽  
Spanning Tree ◽  
Power Flow ◽  
Minimum Spanning Tree ◽  
Grid Connection ◽  
Protection Strategies ◽  
Sample Test ◽  
Minimum Number ◽  
Tree Algorithms ◽  
Bus Networks

<p>Microgrids are the solution to the growing demand for energy in the recent times. It has the potential to improve local reliability, reduce cost and increase penetration rates for distributed renewable energy generation. Inclusion of Renewable Energy Systems (RES) which have become the topic of discussion in the recent times due to acute energy crisis, causes the power flow in the microgrid to be bi-directional in nature. The presence of the RES in the microgrid system causes the grid to be reconfigurable. This reconfiguration might also occur due to load or utility grid connection and disconnection. Thus conventional protection strategies are not applicable to micro-grids and is hence challenging for engineers to protect the grid in a fault condition. In this paper various Minimum Spanning Tree (MST) algorithms are applied in microgrids to identify the active nodes of the current topology of the network in a heuristic approach and thereby generating a tree from the given network so that minimum number of nodes have to be disconnected from the network during fault clearance. In the paper we have chosen the IEEE-39 and IEEE-69 bus networks as our sample test systems.</p>

scholarly journals Investigating the Preferences of Local Residents toward a Proposed Bus Network Redesign in Chattanooga, Tennessee

2021 ◽  
pp. 036119812110130
Author(s):  
Abubakr Ziedan ◽  
Cassidy Crossland ◽  
Candace Brakewood ◽  
Philip Pugliese ◽  
Harrison Ooi
Keyword(s):  
Survey Data ◽  
Planning Process ◽  
Age Groups ◽  
Transit Network ◽  
Transit Service ◽  
Local Residents ◽  
Bus Network ◽  
Bus Networks ◽  
Bus Service ◽  
Transit Agencies

Many transit agencies are considering or implementing bus network redesigns. Considering this growing trend, this study investigates the preferences of local residents for a proposed bus network redesign in Chattanooga, Tennessee. The study uses survey data collected by the Chattanooga Area Regional Transportation Authority and its partners as part of a bus network redesign planning process. Using the survey data, three logit models are estimated to explore preferences between different bus network redesign philosophies, transit network improvements, and willingness to pay for proposed transit improvements and expansion. There are three main findings. First, respondents who ride the bus prefer access to more places over frequent bus service, whereas non-riders prefer more frequent transit service. Second, the models suggest that younger generations are more supportive of transit improvements than older age groups. Third, people living near bus routes and those with higher income levels are more willing to pay for proposed transit improvements. The findings of this study should inform transit agencies that are considering or are in the process of redesigning their bus networks.

scholarly journals Using Open Big Data to Build and Analyze Urban Bus Network Models within and across Administrations

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Sheng Wei ◽  
Lei Wang ◽  
Xiongwu Fu ◽  
Tao Jia
Keyword(s):  
Big Data ◽  
Network Model ◽  
Public Services ◽  
Network Models ◽  
The Body ◽  
Spatial Distance ◽  
County Level ◽  
Urban Bus ◽  
Bus Network ◽  
Bus Networks

Urban bus networks play an important role, when the capacity of urban public services is evaluated. With recent advancements in Internet and Communication Technologies, there is an emerging interest in building an urban bus network model through open big data. This has rarely been investigated and exposes several challenges in the provision of transportation services in urban planning. On the one hand, it is necessary to combine bus stations based on spatial distance constraints due to their ambiguous definition in open big data; on the other hand, it is difficult and time-consuming to relocate and build new stations, but the optimization of bus lines is relatively easy to implement. This study aimed to develop an explicit methodological framework for building and analyzing two different types of urban bus network model using open big data. Thereafter, the framework was applied in two case studies in China, within a county-level administration and in a region including three county-level administrations. The key result shows that there was a shortage of urban bus services across these different administrations. This paper contributes to the body of research methodologies into public transport networks and to understanding the sharing of urban public services across administrations, improving the management of urban bus networks, and highlighting the importance of examining the characteristics of urban bus network in county-level administrations rather than just in large cities in China.

scholarly journals Evaluation of Bus Networks in China: From Topology and Transfer Perspectives

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Hui Zhang ◽  
Peng Zhao ◽  
Yinhai Wang ◽  
Xiangming Yao ◽  
Chengxiang Zhuge
Keyword(s):  
Public Transportation ◽  
Topological Structure ◽  
Small Degree ◽  
Network Evolution ◽  
Transfer Time ◽  
Static Properties ◽  
Random Choice ◽  
The Public ◽  
Bus Network ◽  
Bus Networks

With the development of the public transportation, bus network becomes complicated and hard to evaluate. Transfer time is a vital indicator to evaluate bus network. This paper proposed a method to calculate transfer times using Space P. Four bus networks in China have been studied in this paper. Some static properties based on graph theory and complex theory are used to evaluate bus topological structure. Moreover, a bus network evolution model to reduce transfer time is proposed by adding lines. The adding method includes four types among nodes with random choice, large transfer time, degree, and small degree. The results show that adding lines with nodes of small degree is most effective comparing with the other three types.

scholarly journals Bus transport network analysis in Rio de Janeiro based on topological models using Social Networks

2020 ◽  
Author(s):  
Diego Carvalho ◽  
Rafael Barbastefano ◽  
Louise Pumar
Keyword(s):  
Social Networks ◽  
Rio De Janeiro ◽  
Transportation Network ◽  
Giant Component ◽  
Space Networks ◽  
Minimum Number ◽  
Bus Stops ◽  
Bus Networks ◽  
Topological Models ◽  
Bus System

In recent years, studies on public transport networks have intensified in the Social Networks field, especially in bus networks, motivated by urban mobility’s relevance for the proper functioning of a city. Rio de Janeiro city, Brazil, has undergone recent changes in its municipal bus system, modifying several lines and bus stops due to the preparation for the Olympic games. This paper analyzes the structure of Rio’s bus transportation network of this city using Social Network technics, comparing its topology in 2014 and 2016 – before and after the change and the properties of the bus system investigated based on the topological models B-space, P-space, and C-space. Some essential parameters were calculated, such as giant component, distance, diameter, degree, closeness, and betweenness. The results showed a reduction of 22.75% of the lines and 5.19% of the bus stops from 2014 to 2016. We show that a maximum of four lines is required to move between any two bus stops within the city in both years. However, with three, it is possible to reach more than 99% of the bus stops. Besides, this study also introduces a new C- space network according to the minimum number of frequent bus stops that the lines had. Based on the giant component analysis of these new C-space networks with many common points, it is possible to detect possible expressway corridors.

scholarly journals A Comprehensive TCO Evaluation Method for Electric Bus Systems Based on Discrete-Event Simulation Including Bus Scheduling and Charging Infrastructure Optimisation

2020 ◽  
Author(s):  
Dominic Jefferies ◽  
Dietmar Göhlich
Keyword(s):  
Discrete Event Simulation ◽  
Evaluation Method ◽  
Scheduling Algorithm ◽  
Discrete Event ◽  
Local Conditions ◽  
Charging Infrastructure ◽  
Event Simulation ◽  
Electric Bus ◽  
Bus Network ◽  
Bus Networks

Bus operators around the world are facing the transformation of their fleets from fossil-fuelled to electric buses. Two technologies prevail: Depot charging and opportunity charging at terminal stops. Total cost of ownership (TCO) is an important metric for the decision between the two technologies, however, most TCO studies for electric bus systems rely on generalised route data and simplifying assumptions that may not reflect local conditions. In particular, the need to re-schedule vehicle operations to satisfy electric buses’ range and charging time constraints is commonly disregarded. We present a simulation tool based on discrete-event simulation to determine the vehicle, charging infrastructure, energy and staff demand required to electrify real-world bus networks. These results are then passed to a TCO model. A greedy scheduling algorithm is developed to plan vehicle schedules suitable for electric buses. Scheduling and simulation are coupled with a genetic algorithm to determine cost-optimised charging locations for opportunity charging. A case study is carried out in which we analyse the electrification of a metropolitan bus network consisting of 39 lines with 4748 passenger trips per day. The results generally favour opportunity charging over depot charging in terms of TCO, however, under some circumstances, the technologies are on par. This emphasises the need for detailed analysis of the local bus network in order to make an informed procurement decision.

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