The Impact of Shortest-Path Searches on Dynamic Autonomous Transport Scheduling

Author(s):  
Max Gath ◽  
Otthein Herzog ◽  
Maximilian Vaske
Keyword(s):  
2020 ◽  
Vol 30 (01) ◽  
pp. 2050002
Author(s):  
Carlos Fernandez ◽  
Ioannis Vourkas ◽  
Antonio Rubio

To accelerate the execution of advanced computing tasks, in-memory computing with resistive memory provides a promising solution. In this context, networks of memristors could be used as parallel computing medium for the solution of complex optimization problems. Lately, the solution of the shortest-path problem (SPP) in a two-dimensional memristive grid has been given wide consideration. Some still open problems in such computing approach concern the time required for the grid to reach to a steady state, and the time required to read the result, stored in the state of a subset of memristors that represent the solution. This paper presents a circuit simulation-based performance assessment of memristor networks as SPP solvers. A previous methodology was extended to support weighted directed graphs. We tried memristor device models with fundamentally different switching behavior to check their suitability for such applications and the impact on the timely detection of the solution. Furthermore, the requirement of binary vs. analog operation of memristors was evaluated. Finally, the memristor network-based computing approach was compared to known algorithmic solutions to the SPP over a large set of random graphs of different sizes and topologies. Our results contribute to the proper development of bio-inspired memristor network-based SPP solvers.


2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Peng Xu ◽  
Qian Wu ◽  
Deyang Lu ◽  
Jian Yu ◽  
Yongsheng Rao ◽  
...  

Abstract Background MicroRNAs are a class of important small noncoding RNAs, which have been reported to be involved in the processes of tumorigenesis and development by targeting a few genes. Existing studies show that the imbalance between cell proliferation and apoptosis is closely related to the initiation and development of cancers. However, the impact of miRNAs on this imbalance has not been studied systematically. Results In this study, we first construct a cell fate miRNA-gene regulatory network. Then, we propose a systematical method for calculating the global impact of miRNAs on cell fate genes based on the shortest path. Results on breast cancer and liver cancer datasets show that most of the cell fate genes are perturbed by the differentially expressed miRNAs. Most of the top-identified miRNAs are verified in the Human MicroRNA Disease Database (HMDD) and are related to breast and liver cancers. Function analysis shows that the top 20 miRNAs regulate multiple cell fate related function modules and interact tightly based on their functional similarity. Furthermore, more than half of them can promote sensitivity or induce resistance to some anti-cancer drugs. Besides, survival analysis demonstrates that the top-ranked miRNAs are significantly related to the overall survival time in the breast and liver cancers group. Conclusion In sum, this study can help to systematically study the important role of miRNAs on proliferation and apoptosis and thereby uncover the key miRNAs during the process of tumorigenesis. Furthermore, the results of this study will contribute to the development of clinical therapy based miRNAs for cancers.


2019 ◽  
Vol 20 (1) ◽  
pp. 17-26
Author(s):  
Md. Sharif Hossen ◽  
Muhammad Sajjadur Rahim

Intermittently connected mobile networks are sparsely connected wireless ad-hoc networks where there is no end-to-end path from a source device to a destination. Generally, these paths do not exist. Hence, these devices use intermittent path using the concept of the store-and-forward mechanism to successfully do the communication. These networks are featured by long delay, dissimilar data rates, and larger error rates. Hence, we see the analysis of several delay-tolerant routing protocols, e.g., epidemic, spray-and-wait, prophet, maxprop, rapid, and spray-and-focus using opportunistic network environment simulator. At first, the investigations of the above considered routing protocols are done across three mobility models namely random direction, random walk, and shortest path map based movement mobility model for node impact only. Then, we evaluate these routing protocols against the impact of message copy, buffer, and time-to-live using shortest path map considering the result of node impact. We use three metrics and the result shows that spray-and-focus deserves good performance for showing higher delivery, lower latency, and lower overhead among all routing techniques while epidemic the poor.


2019 ◽  
Vol 11 (22) ◽  
pp. 6275
Author(s):  
Qian Ye ◽  
Hyun Kim

This paper investigates the impact of partial node failure from the perspective of shortest path network problems. We propose a network model that we call shortest path network problems for partial node failure, designed to examine the influence of partial node failures in a flow-based network using a set of indicators. The concept of partial node failure was applied to a special type of hub station, a mandatory transfer in subway or railway systems where multiple lines are arranged for the transfer of passengers. Numerical experiments were carried out on the Washington Metropolitan Area Transit Authority network (WMATA). The results or analysis detail how changes in flow distribution in the network were measured when a station partially failed, as well as ways of identifying heavily impacted stations with respect to different indicators. Various partial node failure scenarios were simulated for origin–destination (OD) flows by days, providing comprehensive information with which to evaluate plans for partial node failures, such as those related to scheduling maintenance, along with insights with which to make contingent plans for potential closure of stations. A major finding emphasizes that the rankings of station criticality are highly sensitive to the different OD flows by days when partial node failures are assumed in network modeling.


2000 ◽  
Vol 10 (01) ◽  
pp. 51-58 ◽  
Author(s):  
SVEN VENEMA ◽  
HONG SHEN ◽  
FRANCIS SURAWEERA

For a weighted, undirected graph G=(V, E) where |V|=n and |E|=m, we examine the single most vital edge with respect to all-pairs shortest paths (APSP) under two different measurements. The first measurement considers only the impact of the removal of a single edge from the APSP on the shortest distance between each vertex pair. The second considers the total weight of all the edges which make up the APSP, that is, calculate the sum of the distance between each vertex pair after the deletion of any edge belonging to a shortest path. We give a sequential algorithm for this problem, and show how to obtain an NC algorithm running in O( log n) time using mn2 processors and O(mn2) space on the MINIMUM CRCW PRAM. Given the shortest distance between each pair of vertices u and v, the diameter of the graph is defined as the longest of these distances. The Most vital edge with respect to the diameter is the edge lying on such a u–v shortest path which when removed causes the greatest increase in the diameter. We show how to modify the above algorithm to solve this problem using the same time and number of processors. Both algorithms compare favourably with the straightforward solution which simply recalculates the all pairs shortest path information.


2013 ◽  
Vol 40 (1) ◽  
pp. 345-355 ◽  
Author(s):  
Leonardo C.T. Bezerra ◽  
Elizabeth F.G. Goldbarg ◽  
Marco C. Goldbarg ◽  
Luciana S. Buriol

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Ningning Zhao ◽  
Nan Li ◽  
Yu Sun ◽  
Zheng Gao

Most of the traditional taxi path planning studies assume that the aircraft is in uniform speed, and the model is optimized based on the shortest taxi time. Although it is easy to solve, it does not consider the change of the speed profile when the aircraft turns, and the optimal taxiing time of the aircraft does not necessarily bring the optimal taxiing fuel consumption. In this paper, the aircraft’s taxi distance and the number of turns in the taxi are considered. The aircraft path planning model with the shortest total distance of the airport surface is established. The improved A ∗ algorithm is used to obtain the shortest path P. Based on this, the shortest path P is established. Considering the multitarget velocity profile model of time and fuel consumption, a heuristic search is used to generate an accurate velocity profile for each path to obtain a 4D trajectory of the aircraft and then quantitative analysis of the impact of aircraft pollutant emissions on the airport environment based on 4D trajectory taxi time. The experimental results show that, compared with the traditional optimization method without considering the turning times, the total taxiing distance and turning times of the aircraft are greatly reduced. By balancing the taxiing time and fuel consumption, a set of Pareto-optimal velocity profiles is generated for the aircraft taxiing path; at the same time, it will help the airport save energy and reduce emissions and improve the quality of the airport environment. It has a high practical application value and is expected to be applied in the real-time air traffic control decision of aircraft surface in the future.


2014 ◽  
Vol 548-549 ◽  
pp. 1299-1303 ◽  
Author(s):  
Mohammad Z. Masoud ◽  
Ismael A. Jannoud

Modeling Internet structure as an autonomous system (AS) graph is considered one of the most common methods to study the Internet. AS-graph is constructed by utilizing ASes from the Internet. The AS number was 16-bit address. It reduced the size of ASes scope in one hand and made the AS graph small and easy to be produced and modeled. However, the number of ASes has exceeded the 16-bits limits. The 32-bit addressing has emerged as a method to tackle this problem. This increasing in the AS number scope converted the AS graph into a massive graph with unpredicted number of ASes. In this paper, we attempt to study the impact of 32-bits addresses on the AS graph. Graph parameters have been utilized to measure this impact. To this end, we have constructed two AS-graphs, a 16-bits-AS graph and a full AS graph. We have compared these graphs according to cluster coefficient, betweenness centrality, node degree and average shortest path. Our results demonstrated that the 32-bits ASes are popular. Moreover, these ASes have an effect on reducing the value of the global cluster coefficient and increasing the average shortest path. We observed that the number of vertexes that connect 16-bits and 32-bits ASes is small and requires more inferring.


2021 ◽  
Author(s):  
Gaurav H Patel ◽  
David C. Gruskin ◽  
Sophie C. Arkin ◽  
Emery C. Jamerson ◽  
Daniel R. Ruiz-Betancourt ◽  
...  

Background: Efficient processing of complex and dynamic social scenes relies on intact connectivity of many underlying cortical areas and networks, but how connectivity deficits affect this functioning in social cognition remains unknown. Here we measure these relationships using functionally based localization of social cognition areas, resting-state functional connectivity, and movie-watching data. Methods: In 42 schizophrenia participants (SzP) and 41 healthy controls (HC), we measured the functional connectivity of areas localized by face-emotion processing, theory-of-mind, and attention tasks. We quantified the weighted shortest path length between visual and medial prefrontal theory-of-mind areas in both populations to assess the impact of functional connectivity deficits on network structure. We then correlated connectivity along the shortest path in each group with movie-evoked activity in a key node of the theory-of-mind network (TPJp). Results: SzP had pronounced connectivity deficits in temporoparietal junction/posterior superior temporal sulcus (TPJ-pSTS) areas involved in face-emotion processing (t(81)=4.4, p=0.00002). In HC the shortest path connecting visual and medial prefrontal theory-of-mind areas passed through TPJ-pSTS, whereas in SzP the shortest path passed through prefrontal cortex (PFC). While movie-evoked TPJp activity correlated with connectivity along the TPJ-pSTS pathway in both groups (r=0.43, p=0.002), it additionally correlated with connectivity along the PFC pathway only in SzP (rSzP=0.56, p=0.003). Conclusions: Connectivity along the human-unique TPJ-pSTS pathway affects both the network architecture and functioning of areas involved in processing complex dynamic social scenes. These results demonstrate how focal deficits can have widespread impacts across cortex.


2018 ◽  
Vol 6 (2) ◽  
pp. 105-114 ◽  
Author(s):  
Rully Pramudita ◽  
Nadya Safitri

Abstract In a large city, there are many congestion problems, so the selection of the fastest route to reach the destination is needed. The city of Bandung is one of the big cities in Indonesia which has a fairly crowded traffic density and tends to be a lot of congestion in it. So we need a study that can discuss the path of independence. In the study to determine the shortest path there are several algorithm options to solve it. This research was conducted using the Bellman Ford algorithm to try to solve the problem of selecting the fastest path. The case that will be focused on in this study covers the route that starts from Ir. H. Juanda street and ends at the Leuwipanjang bus terminal. The road node that will be passed is taken from several main points that will be passed. Calculation of coordinates will be calculated using the concept of graph and haversine formula. The impact of this research is that it can be known the fastest path needed using the Bellman Ford algorithm.   Keywords: Algoritm, Bellman Ford, Graph, Haversine Formula, Shortest Path.   Abstrak   Dalam sebuah kota besar saat ini banyak sekali permasalahan kemacetan, maka dibutuhkan pemilihan rute jalan yang tercepat untuk mencapai tujuan. Kota Bandung merupakan salah satu kota besar di Indonesia yang memiliki kepadatan lalu lintas cukup ramai dan cenderung banyak terjadi kemacetan didalamnya. Maka diperlukan sebuah penelitian yang dapat membahas mengenai jalur tependek. Dalam kajian untuk menentukan jalur terpendek terdapat beberapa pilihan algoritma untuk menyelesaikannya. Penelitian ini dilakukan menggunakan algoritma Bellman Ford untuk mencoba menyelesaikan masalah pemilihan jalur tercepat. Kasus yang akan difokuskan dalam penelitian ini mencangkup rute yang dimulai dari jalan Ir.H.Djuanda dan berakhir di terminal bis Leuwipanjang. Simpul jalan yang akan dilalui diambil dari beberapa titik utama yang akan dapat dilewati. Perhitungan koordinat akan dihitung menggunakan konsep graf dan haversine formula. Dampak dari penelitian ini yaitu dapat diketahuinya jalur tercepat yang dibutuhkan menggunakan algoritma Bellman Ford.   Kata kunci: Algoritma, Bellman Ford, Graf, Haversine Formula, Shortest Path.


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