scholarly journals A packet replication algorithm for delay tolerant networks based on multi-metric

2021 ◽  
Vol 2093 (1) ◽  
pp. 012023
Author(s):  
Yongguang Liu
Keyword(s):  
Utility Function ◽  
Entropy Weight ◽  
Average Delay ◽  
Original Algorithm ◽  
Performance Metric ◽  
Replication Number ◽  
Encounter Time ◽  
Delay Tolerant ◽  
Utility Metrics ◽  
The Impact

Abstract Utility function of packet is often used to decide how to replicate packet in DTN networks. But this method has more uncertainty and relies on a single performance metric. For this problem, in order to reduce the impact of a single metric uncertainty, multiple utility metrics are introduced in the new algorithm. A packet replication probability calculation method based on entropy weight is designed. By calculating the entropy weight of each metric, the algorithm obtains the replication probability of each packet and takes the probability as the priority of packet replication. Because of considering the two metrics of packet expected transmission delay and node encounter possibility, the algorithm effectively reduces the influence of encounter time distribution problem and direction prediction problem in the original algorithm, and reduces the uncertainty of utility function. Simulation results show that the algorithm reduces the packet replication number and the average delay, improves the successful packet delivery rate. The overall performance of the network is further improved.

scholarly journals Integrated IEW-TOPSIS and Fire Dynamics Simulation for Agent-Based Evacuation Modeling in Industrial Safety

Safety ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 47
Author(s):  
Wattana Chanthakhot ◽  
Kasin Ransikarbum
Keyword(s):  
Emergency Evacuation ◽  
Industrial Sector ◽  
Industrial Safety ◽  
Dynamics Simulation ◽  
Entropy Weight ◽  
Fire Dynamics ◽  
Evacuation Simulation ◽  
Evacuation Modeling ◽  
Agent Based ◽  
The Impact

Emergency events in the industrial sector have been increasingly reported during the past decade. However, studies that focus on emergency evacuation to improve industrial safety are still scarce. Existing evacuation-related studies also lack a perspective of fire assembly point’s analysis. In this research, location of assembly points is analyzed using the multi-criteria decision analysis (MCDA) technique based on the integrated information entropy weight (IEW) and techniques for order preference by similarity to ideal solution (TOPSIS) to support the fire evacuation plan. Next, we propose a novel simulation model that integrates fire dynamics simulation coupled with agent-based evacuation simulation to evaluate the impact of smoke and visibility from fire on evacuee behavior. Factors related to agent and building characteristics are examined for fire perception of evacuees, evacuees with physical disabilities, escape door width, fire location, and occupancy density. Then, the proposed model is applied to a case study of a home appliance factory in Chachoengsao, Thailand. Finally, results for the total evacuation time and the number of remaining occupants are statistically examined to suggest proper evacuation planning.

scholarly journals Analysis of Brand Visual Design Based on Collaborative Filtering Algorithm

2022 ◽  
Vol 2022 ◽  
pp. 1-8
Author(s):  
Gao Chaomeng ◽  
Wang Yonggang
Keyword(s):  
Collaborative Filtering ◽  
Visual Communication ◽  
Visual Design ◽  
Design System ◽  
Original Algorithm ◽  
Filtering Algorithm ◽  
Visual Communication Design ◽  
Communication Design ◽  
Collaborative Filtering Algorithm ◽  
The Impact

With the continuous development of China’s social economy, the competitiveness of brand market is gradually increasing. In order to improve their own level in brand building, major enterprises gradually explore and study visual communication design. Brand visual design has also received more and more attention. Building a complete and rich visual design system can improve the brand level and attract users to consume. Based on the abovementioned situation, this paper proposes to use collaborative filtering algorithm to analyze and study brand visual design. Firstly, a solution is proposed to solve the problem of low accuracy of general recommendation algorithm in brand goods. Collaborative filtering algorithm is used to analyze the visual communication design process of enterprise brand. Research on personalized image design according to consumers’ trust and recognition of brand design is conducted. In traditional craft brand visual design, we mainly study the impact of image design on consumer behavior. The brand loyalty model is used to predict and analyze the visual design effect. Also, the user’s evaluation coefficient is taken as the expression of brand visual design recognition. Finally, the collaborative filtering algorithm is optimized to improve the consumer similarity based on the original algorithm. The results show that the brand visual design using collaborative filtering algorithm can help enterprises obtain greater benefits in their own brand construction. It provides effective data help in the development of traditional craft brands.

scholarly journals Technical note: PMR – a proxy metric to assess hydrological model robustness in a changing climate

2021 ◽  
Author(s):  
Paul Royer-Gaspard ◽  
Vazken Andréassian ◽  
Guillaume Thirel
Keyword(s):  
Hydrological Model ◽  
Evaluation Studies ◽  
Computational Cost ◽  
Climatic Conditions ◽  
Technical Note ◽  
Performance Metric ◽  
Reliable Assessment ◽  
Sample Test ◽  
The Impact ◽  
Model Robustness

Abstract. The ability of hydrological models to perform in climatic conditions different from those encountered in calibration is crucial to ensure a reliable assessment of the impact of climate change in water management sectors. However, most evaluation studies based on the Differential Split-Sample Test (DSST) endorsed the consensus that rainfall-runoff models lack climatic robustness. Models typically exhibit substantial errors on streamflow volumes applied under climatologically different conditions. In this technical note, we propose a new performance metric to evaluate model robustness without applying the DSST and which performs with a single hydrological model calibration. The Proxy for Model Robustness (PMR) is based on the systematic computation of model error on sliding sub-periods of the whole streamflow time series. We demonstrate that the metric shows patterns similar to those obtained with the DSST for a conceptual model on a set of 377 French catchments. An analysis of sensitivity to the length of the sub-periods shows that this length influences the values of the PMR and its adequation with DSST biases. We recommend a range of a few years for the choice of sub-period lengths, although this should be context-dependent. Our work makes it possible to evaluate the temporal transferability of any hydrological model, including uncalibrated models, at a very low computational cost.

The Impact of Delayed Symptomatic Treatment Implementation in the Intensive Care Unit

Healthcare ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 35
Author(s):  
Lesley Meng ◽  
Krzysztof Laudanski ◽  
Mariana Restrepo ◽  
Ann Huffenberger ◽  
Christian Terwiesch
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Medical Center ◽  
Academic Medical Center ◽  
Symptomatic Treatment ◽  
Medication Administration ◽  
Average Delay ◽  
Treatment Implementation ◽  
Medication Delivery ◽  
The Impact

We estimated the harm related to medication delivery delays across 12,474 medication administration instances in an intensive care unit using retrospective data in a large urban academic medical center between 2012 and 2015. We leveraged an instrumental variables (IV) approach that addresses unobserved confounds in this setting. We focused on nurse shift changes as disruptors of timely medication (vasodilators, antipyretics, and bronchodilators) delivery to estimate the impact of delay. The average delay around a nurse shift change was 60.8 min (p < 0.001) for antipyretics, 39.5 min (p < 0.001) for bronchodilators, and 57.1 min (p < 0.001) for vasodilators. This delay can increase the odds of developing a fever by 32.94%, tachypnea by 79.5%, and hypertension by 134%, respectively. Compared to estimates generated by a naïve regression approach, our IV estimates tend to be higher, suggesting the existence of a bias from providers prioritizing more critical patients.

scholarly journals Spatial and seasonal effects on the delayed ionospheric response to solar EUV changes

2019 ◽  
Author(s):  
Erik Schmölter ◽  
Jens Berdermann ◽  
Norbert Jakowski ◽  
Christoph Jacobi
Keyword(s):  
Southern Hemisphere ◽  
Geomagnetic Activity ◽  
Correlation Coefficients ◽  
Seasonal Effects ◽  
Constant Delay ◽  
Average Delay ◽  
Ionospheric Response ◽  
The Difference ◽  
Longitudinal Variability ◽  
The Impact

Abstract. This study correlates different ionospheric parameters with the integrated solar EUV radiation for an analysis of the delayed ionospheric response in order to confirm previous studies on the delay and to further specify variations of the delay. Several time series for correlation coefficients and delays are presented to characterize the trend of the delay from 2011 to 2013. The impact of the diurnal variations of ionospheric parameters in the analysis on hourly resolution for fixed locations are discussed and specified with calculations in different time scales and with comparison to solar and geomagnetic activity. An average delay for TEC of &amp;approx; 18.7 hours and for foF2 of &amp;approx; 18.6 hours is calculated at four European stations. Through comparison with the Australian region the difference between northern and southern hemisphere is analyzed and a seasonal variation of the delay between northern and southern hemisphere is calculated for TEC with &amp;approx; 5 ± 0.7 hours and foF2 with &amp;approx; 8 ± 0.8 hours. The latitudinal and longitudinal variability of the delay is analyzed for the European region and a decrease of the delay from &amp;approx; 21.5 hours at 30° N to &amp;approx; 19.0 hours at 70° N has been found. For winter months a roughly constant delay of &amp;approx; 19.5 hours is calculated. In this study a North-South trend of the ionospheric delay during summer month has been observed with &amp;approx; 0.06 hours per degree in latitude. The results based on solar and ionospheric data in hourly resolution and the analysis of the delayed ionospheric response to solar EUV show the seasonal and latitudinal variations. Results also indicate the dependence on the geomagnetic activity as well as on the 11-year solar cycle.

scholarly journals The Feasibility of Opening Communities -- Based on the Wiedemann Car-Following Model

2018 ◽  
Vol 11 (3) ◽  
pp. 57
Author(s):  
Xiao-Yan Cao ◽  
Bing-Qian Liu ◽  
Bao-Ru Pan ◽  
Yuan-Biao Zhang
Keyword(s):  
Traffic Congestion ◽  
Large Scale ◽  
Gated Communities ◽  
Urban Traffic ◽  
Average Delay ◽  
Traffic Demand ◽  
Car Following ◽  
Car Following Model ◽  
Urbanization In China ◽  
The Impact

With the accelerating development of urbanization in China, the increasing traffic demand and large scale gated communities have aggravated urban traffic congestion. This paper studies the impact of communities opening on road network structure and the surrounding road capacity. Firstly, we select four indicators, namely average speed, vehicle flow, average delay time, and queue length, to measure traffic capacity. Secondly, we establish the Wiedemann car-following model, then use VISSIM software to simulate the traffic conditions of surrounding roads of communities. Finally, we take Shenzhen as an example to simulate and compare the four kinds of gated communities, axis, centripetal and intensive layout, and we also analyze the feasibility of opening communities.

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