scholarly journals Shortest Path Computing in Directed Graphs with Weighted Edges Mapped on Random Networks of Memristors

2020 ◽  
Vol 30 (01) ◽  
pp. 2050002
Author(s):  
Carlos Fernandez ◽  
Ioannis Vourkas ◽  
Antonio Rubio
Keyword(s):  
Shortest Path ◽  
Optimization Problems ◽  
Circuit Simulation ◽  
Directed Graphs ◽  
Switching Behavior ◽  
Large Set ◽  
Open Problems ◽  
Time Required ◽  
The Impact ◽  
Computing Approach

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.

scholarly journals The feasibility of proton exchange membrane fuel cells

2021 ◽  
Author(s):  
Mina Safe
Keyword(s):  
Genetic Algorithm ◽  
Fuel Cells ◽  
Proton Exchange Membrane ◽  
Optimization Problems ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Cellulose Membrane ◽  
Large Set ◽  
Exchange Membrane ◽  
The Impact

Proton exchange membrane (PEM) fuel cells' main components are the anode, cathode and the membrane. A conventional membrane used in today's PEM fuel cells is the Nafion 117 membrane. In this project, the Nafion 177 membrane is discussed in detail to demonstrate its ability to absorb water and the capability to operate in a specific range of temperatures. In addition, an extensive simulation using CATIA V5 is used to determine the highest stress distribution on the membrane for various boundary conditions. Other membranes materials were also considered in this report. They include the Dias membrane, the bacterial cellulose membrane to expand the selection of candidate membranes that can be used im PEM fuel cells for future research. Optimization methods were utilized to maximize the performance of the PEM fuel cells. The Genetic Algorithm is used to solve optimization problems by implementing powerful search techniques to find an optimal solution within a large set of solutions. In this project, the Genetic Algorithm is used to show the impact of the stack positions in order to optimize voltage output. In addition, the Nafion content and platinum loading are adjusted to optimize the performance of the current density within PEM fuel cells.

scholarly journals The feasibility of proton exchange membrane fuel cells

2021 ◽  
Author(s):  
Mina Safe
Keyword(s):  
Genetic Algorithm ◽  
Fuel Cells ◽  
Proton Exchange Membrane ◽  
Optimization Problems ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Cellulose Membrane ◽  
Large Set ◽  
Exchange Membrane ◽  
The Impact

Proton exchange membrane (PEM) fuel cells' main components are the anode, cathode and the membrane. A conventional membrane used in today's PEM fuel cells is the Nafion 117 membrane. In this project, the Nafion 177 membrane is discussed in detail to demonstrate its ability to absorb water and the capability to operate in a specific range of temperatures. In addition, an extensive simulation using CATIA V5 is used to determine the highest stress distribution on the membrane for various boundary conditions. Other membranes materials were also considered in this report. They include the Dias membrane, the bacterial cellulose membrane to expand the selection of candidate membranes that can be used im PEM fuel cells for future research. Optimization methods were utilized to maximize the performance of the PEM fuel cells. The Genetic Algorithm is used to solve optimization problems by implementing powerful search techniques to find an optimal solution within a large set of solutions. In this project, the Genetic Algorithm is used to show the impact of the stack positions in order to optimize voltage output. In addition, the Nafion content and platinum loading are adjusted to optimize the performance of the current density within PEM fuel cells.

The Map-Based Shortest Route Selection by Using Ant Colony Optimization Algorithm

2018 ◽  
Vol 1 (1) ◽  
pp. 15
Author(s):  
Achmad Fanany Onnilita Gaffar ◽  
Agusma Wajiansyah ◽  
Supriadi Supriadi
Keyword(s):  
Ant Colony Optimization ◽  
Shortest Path ◽  
Optimization Algorithm ◽  
Optimization Problems ◽  
Google Earth ◽  
Ant Colony ◽  
Food Sources ◽  
Shortest Route ◽  
Study Results ◽  
Destination Point

The shortest path problem is one of the optimization problems where the optimization value is a distance. In general, solving the problem of the shortest route search can be done using two methods, namely conventional methods and heuristic methods. The Ant Colony Optimization (ACO) is the one of the optimization algorithm based on heuristic method. ACO is adopted from the behavior of ant colonies which naturally able to find the shortest route on the way from the nest to the food sources. In this study, ACO is used to determine the shortest route from Bumi Senyiur Hotel (origin point) to East Kalimantan Governor's Office (destination point). The selection of the origin and destination points is based on a large number of possible major roads connecting the two points. The data source used is the base map of Samarinda City which is cropped on certain coordinates by using Google Earth app which covers the origin and destination points selected. The data pre-processing is performed on the base map image of the acquisition results to obtain its numerical data. ACO is implemented on the data to obtain the shortest path from the origin and destination point that has been determined. From the study results obtained that the number of ants that have been used has an effect on the increase of possible solutions to optimal. The number of tours effect on the number of pheromones that are left on each edge passed ant. With the global pheromone update on each tour then there is a possibility that the path that has passed the ant will run out of pheromone at the end of the tour. This causes the possibility of inconsistent results when using the number of ants smaller than the number of tours.

scholarly journals Exoplanet mass estimation for a sample of targets for the Ariel mission

2021 ◽  
Author(s):  
J. R. Barnes ◽  
C. A. Haswell
Keyword(s):  
Radial Velocity ◽  
Input Parameter ◽  
Noise Sources ◽  
Time Commitment ◽  
Low Mass ◽  
Time Required ◽  
Fixed Input ◽  
The Impact ◽  
Quadrature Sampling

AbstractAriel’s ambitious goal to survey a quarter of known exoplanets will transform our knowledge of planetary atmospheres. Masses measured directly with the radial velocity technique are essential for well determined planetary bulk properties. Radial velocity masses will provide important checks of masses derived from atmospheric fits or alternatively can be treated as a fixed input parameter to reduce possible degeneracies in atmospheric retrievals. We quantify the impact of stellar activity on planet mass recovery for the Ariel mission sample using Sun-like spot models scaled for active stars combined with other noise sources. Planets with necessarily well-determined ephemerides will be selected for characterisation with Ariel. With this prior requirement, we simulate the derived planet mass precision as a function of the number of observations for a prospective sample of Ariel targets. We find that quadrature sampling can significantly reduce the time commitment required for follow-up RVs, and is most effective when the planetary RV signature is larger than the RV noise. For a typical radial velocity instrument operating on a 4 m class telescope and achieving 1 m s−1 precision, between ~17% and ~ 37% of the time commitment is spent on the 7% of planets with mass Mp < 10 M⊕. In many low activity cases, the time required is limited by asteroseismic and photon noise. For low mass or faint systems, we can recover masses with the same precision up to ~3 times more quickly with an instrumental precision of ~10 cm s−1.

scholarly journals Evaluating the Impact of Intensive Case Management for Severe Vocational Injuries on Work Incapacity and Costs

2021 ◽  
Author(s):  
Rolando Leiva ◽  
Lise Rochaix ◽  
Noémie Kiefer ◽  
Jean-Claude K. Dupont
Keyword(s):  
Treatment Group ◽  
Case Management ◽  
Sick Leave ◽  
Insurance Fund ◽  
Large Set ◽  
Intensive Case Management ◽  
Exact Matching ◽  
Case Management Program ◽  
The Impact ◽  
Permanent Work

AbstractPurpose This study investigates the impact of an intensive case management program on sick leave days, permanent work incapacity levels and treatment costs for severe vocational injuries set up by the French National Insurance Fund in five health insurance districts. Methods The method employed relies on a four-step matching procedure combining Coarsened Exact Matching and Propensity Score Matching, based on an original administrative dataset. Average Treatment effects on the Treated were estimated using a parametric model with a large set of covariates. Results After one-year follow-up, workers in the treatment group had higher sickness absence rates, with 22 extra days, and the program led to 2.7 (95% CI 2.3–3.1) times more diagnoses of permanent work incapacity in the treatment group. With an estimated yearly operational cost of 2,722 € per treated worker, the average total extra treatment cost was 4,569 € for treated workers, which corresponds to a cost increase of 29.2% for the insurance fund. Conclusions The higher costs found for the treatment group are mainly due to longer sick leave duration for the moderate severity group, implying higher cash transfers in the form of one-off indemnities. Even though workers in the treated group have more diagnoses of permanent work incapacity, the difference of severity between groups is small. Our results on longer sick leave duration are partly to be explained by interactions between the case managers and the occupational physicians that encouraged patients to stay longer off-work for better recovery, despite the higher costs that this represented for the insurance fund and the well-documented adverse side effects of longer periods off-work.

An experimental study of Web switching behavior

2003 ◽  
Vol 22 (2) ◽  
pp. 87-93
Author(s):  
James Otto ◽  
Mohammad Najdawi ◽  
William Wagner
Keyword(s):  
Experimental Study ◽  
Electronic Commerce ◽  
Web Site ◽  
Waiting Times ◽  
Switching Behavior ◽  
The Internet ◽  
Wait Times ◽  
Web Page ◽  
Extensive Growth ◽  
The Impact

With the extensive growth of the Internet and electronic commerce, the issue of how users behave when confronted with long download times is important. This paper investigates Web switching behavior. The paper describes experiments where users were subjected to artificially delayed Web page download times to study the impact of Web site wait times on switching behavior. Two hypotheses were tested. First, that longer wait times will result in increased switching behavior. The implication being that users become frustrated with long waiting times and choose to go elsewhere. Second, that users who switch will benefit, in terms of decreased download times, from their decision to switch.

Graphical structure of extended b-metric spaces: an application to the transverse oscillations of a homogeneous bar

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mudasir Younis ◽  
Deepak Singh ◽  
Ishak Altun ◽  
Varsha Chauhan
Keyword(s):  
Metric Spaces ◽  
Fixed Point Theory ◽  
Directed Graphs ◽  
Point Theory ◽  
Graph Structure ◽  
Open Ball ◽  
Open Problems ◽  
Graphical Structure ◽  
State Of Art ◽  
Transverse Oscillations

Abstract The purpose of this article is to present the notion of graphical extended b-metric spaces, blending the concepts of graph theory and metric fixed point theory. We discuss the structure of an open ball of the new proposed space and elaborate on the newly introduced ideas in a novel way by portraying suitably directed graphs. We also provide some examples in graph structure to show that our results are sharp as compared to the results in the existing state-of-art. Furthermore, an application to the transverse oscillations of a homogeneous bar is entrusted to affirm the applicability of the established results. Additionally, we evoke some open problems for enthusiastic readers for the future aspects of the study.

A Dicode Signaling Scheme for Capacitively Coupled Interface

2011 ◽  
Vol 497 ◽  
pp. 296-305
Author(s):  
Yasushi Yuminaka ◽  
Kyohei Kawano
Keyword(s):  
Partial Response ◽  
Data Transmission ◽  
High Speed ◽  
Circuit Simulation ◽  
Frequency Bandwidth ◽  
Capacitively Coupled ◽  
Limited Frequency ◽  
Simulation Results ◽  
Response Coding ◽  
The Impact

In this paper, we present a bandwidth-efficient partial-response signaling scheme for capacitivelycoupled chip-to-chip data transmission to increase data rate. Partial-response coding is knownas a technique that allows high-speed transmission while using a limited frequency bandwidth, by allowingcontrolled intersymbol interference (ISI). Analysis and circuit simulation results are presentedto show the impact of duobinary (1+D) and dicode (1-D) partial-response signaling for capacitivelycoupled interface.

scholarly journals Optimal Pricing Strategy of Electric Vehicle Charging Station for Promoting Green Behavior Based on Time and Space Dimensions

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Xiaomin Xu ◽  
Dongxiao Niu ◽  
Yan Li ◽  
Lijie Sun
Keyword(s):  
Electric Vehicles ◽  
Optimization Problems ◽  
Power Grid ◽  
Economic Benefits ◽  
Pricing Strategy ◽  
Optimal Pricing ◽  
Electricity Pricing ◽  
Optimal Pricing Strategy ◽  
Charging Stations ◽  
The Impact

Considering that the charging behaviors of users of electric vehicles (EVs) (including charging time and charging location) are random and uncertain and that the disorderly charging of EVs brings new challenges to the power grid, this paper proposes an optimal electricity pricing strategy for EVs based on region division and time division. Firstly, by comparing the number of EVs and charging stations in different districts of a city, the demand ratio of charging stations per unit is calculated. Secondly, according to the demand price function and the principle of profit maximization, the charging price between different districts of a city is optimized to guide users to charge in districts with more abundant charging stations. Then, based on the results of the zonal pricing strategy, the time-of-use (TOU) pricing strategy in different districts is discussed. In the TOU pricing model, consumer satisfaction, the profit of power grid enterprises, and the load variance of the power grid are considered comprehensively. Taking the optimization of the comprehensive index as the objective function, the TOU pricing optimization model of EVs is constructed. Finally, the nondominated sorting genetic algorithm (NSGA-II) is introduced to solve the above optimization problems. The specific data of EVs in a municipality directly under the Central Government are taken as examples for this analysis. The empirical results demonstrate that the peak-to-valley ratio of a certain day in the city is reduced from 56.8% to 43% by using the optimal pricing strategy, which further smooth the load curve and alleviates the impact of load fluctuation. To a certain extent, the problem caused by the uneven distribution of electric vehicles and charging stations has been optimized. An orderly and reasonable electricity pricing strategy can guide users to adjust charging habits, to ensure grid security, and to ensure the economic benefits of all parties.

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