scholarly journals Path Optimization along Buoys Based on the Shortest Path Tree with Uncertain Atmospheric and Oceanographic Data

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Han Xue ◽  
Tian Chai
Keyword(s):  
Shortest Path ◽  
Wave Speed ◽  
S Wave ◽  
Average Wind Speed ◽  
Shortest Path Tree ◽  
Total Distance ◽  
Average Wind ◽  
Travelling Time ◽  
Bad Weather ◽  
Ship Speed

In order to design an optimized route for ships in line with economic benefits; avoid bad weather; reduce unnecessary detours; shorten the navigation time; and achieve the purpose of safety, fuel saving, and punctual arrival, this paper takes the navigation mark as the node of the tree, takes the connection of the adjacent navigation marks as the tree path, and divides the distance of the adjacent buoys by the ship’s speed as the path cost. The speed calculation collects the current hydrometeorological data such as wind and wave data, uses Aertssen’s deceleration formula to adjust the speed, and improves Dijkstra to find the shortest path. In the experiment, two routes from Dongdu to Xiamen Gang Kou are compared under bad weather conditions. Route 1 is with 5.877 m/s average wind speed, 0.860 m/s wave speed, and total distance 34717 m. Route 2 is with 8.503 m/s average wind speed, 1.429 m/s wave speed, and total distance 30223 m. The calculated ship speed travelling in route 1 is 12.243 km, and its travelling time is 1.53 h. The calculated ship speed travelling in route 2 is 10.523 km, and its travelling time is 1.55 h. Although the total distance of route 1 is longer, it takes less time for ships to travel in route 1. The experimental results verify the effectiveness of the navigation algorithm based on the shortest path tree of uncertain weather maps.

SHAPING OF AN AUTONOMOUS POWER SYSTEM FOR GUARANTEED POWER SUPPLY WITH THE PREDOMINANCE WIND ENERGY

2018 ◽  
pp. 28-50
Author(s):  
S. G. Ignatiev ◽  
S. V. Kiseleva
Keyword(s):  
Energy Storage ◽  
Wind Speed ◽  
Wind Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Energy Demand ◽  
Diesel Generator ◽  
Average Wind Speed ◽  
Wind Speeds ◽  
Average Wind

Optimization of the autonomous wind-diesel plants composition and of their power for guaranteed energy supply, despite the long history of research, the diversity of approaches and methods, is an urgent problem. In this paper, a detailed analysis of the wind energy characteristics is proposed to shape an autonomous power system for a guaranteed power supply with predominance wind energy. The analysis was carried out on the basis of wind speed measurements in the south of the European part of Russia during 8 months at different heights with a discreteness of 10 minutes. As a result, we have obtained a sequence of average daily wind speeds and the sequences constructed by arbitrary variations in the distribution of average daily wind speeds in this interval. These sequences have been used to calculate energy balances in systems (wind turbines + diesel generator + consumer with constant and limited daily energy demand) and (wind turbines + diesel generator + consumer with constant and limited daily energy demand + energy storage). In order to maximize the use of wind energy, the wind turbine integrally for the period in question is assumed to produce the required amount of energy. For the generality of consideration, we have introduced the relative values of the required energy, relative energy produced by the wind turbine and the diesel generator and relative storage capacity by normalizing them to the swept area of the wind wheel. The paper shows the effect of the average wind speed over the period on the energy characteristics of the system (wind turbine + diesel generator + consumer). It was found that the wind turbine energy produced, wind turbine energy used by the consumer, fuel consumption, and fuel economy depend (close to cubic dependence) upon the specified average wind speed. It was found that, for the same system with a limited amount of required energy and high average wind speed over the period, the wind turbines with lower generator power and smaller wind wheel radius use wind energy more efficiently than the wind turbines with higher generator power and larger wind wheel radius at less average wind speed. For the system (wind turbine + diesel generator + energy storage + consumer) with increasing average speed for a given amount of energy required, which in general is covered by the energy production of wind turbines for the period, the maximum size capacity of the storage device decreases. With decreasing the energy storage capacity, the influence of the random nature of the change in wind speed decreases, and at some values of the relative capacity, it can be neglected.

scholarly journals Analysis of Performance of the Wind-Driven Pulverizing Aerator Based on Average Wind Speeds in the Conditions of Góreckie Lake

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2796
Author(s):  
Andrzej Osuch ◽  
Ewa Osuch ◽  
Stanisław Podsiadłowski ◽  
Piotr Rybacki
Keyword(s):  
Mathematical Model ◽  
Wind Speed ◽  
Water Pump ◽  
Average Wind Speed ◽  
Flow Rates ◽  
Wind Speeds ◽  
Average Wind ◽  
Flow Through ◽  
Analysis Of Performance ◽  
Research Period

In the introduction to this paper, the characteristics of Góreckie lake and the construction and operation of the wind-driven pulverizing aerator are presented. The purpose of this manuscript is to determine the efficiency of the pulverizing aerator unit in the windy conditions of Góreckie Lake. The efficiency of the pulverization aerator depends on the wind conditions at the lake. It was necessary to conduct thorough research to determine the efficiency of water flow through the pulverization segment (water pump). It was necessary to determine the rotational speed of the paddle wheel, which depended on the average wind speed. Throughout the research period, measurements of hourly average wind speed were carried out. It was possible to determine the efficiency of the machine by developing a dedicated mathematical model. The latest method was used in the research, consisting of determining the theoretical volumetric flow rates of water in the pulverizing aerator unit, based on average hourly wind speeds. Pulverization efficiency under the conditions of Góreckie Lake was determined based on 6600 average wind speeds for spring, summer and autumn, 2018. Based on the model, the theoretical efficiency of the machine was calculated, which, under the conditions of Góreckie Lake, amounted to 75,000 m3 per year.

scholarly journals A bi-level encoding scheme for the clustered shortest-path tree problem in multifactorial optimization

2021 ◽  
Vol 100 ◽  
pp. 104187 ◽  
Author(s):  
Huynh Thi Thanh Binh ◽  
Ta Bao Thang ◽  
Nguyen Duc Thai ◽  
Pham Dinh Thanh
Keyword(s):  
Shortest Path ◽  
Shortest Path Tree ◽  
Encoding Scheme

Development and Field Testing of an Inclined Flanged Compact Diffuser for a Micro Wind Turbine

2014 ◽  
Author(s):  
Sandip Kale ◽  
S. N. Sapali
Keyword(s):  
Wind Turbine ◽  
Wind Velocity ◽  
Wind Turbines ◽  
Energy Production ◽  
Cost Effective ◽  
Field Testing ◽  
International Electrotechnical Commission ◽  
Average Wind Speed ◽  
Average Wind ◽  
Power Curves

Micro wind turbines installed in various applications, experience average wind speed for most of the time during operations. Power produced by the wind turbine is proportional to the cubic power of the wind velocity and a small increase in wind velocity results increases power output significantly. The approach wind velocity can be increased by covering traditional wind turbine with a diffuser. Researchers are continuously working to develop a compact, lightweight, cost effective and feasible diffuser for wind turbines. The present work carried out to develop a diffuser with these stated objectives. A compact, lightweight inclined flanged diffuser developed for a micro wind turbine. Bare micro wind turbine and wind turbine covered with developed efficient inclined flanged diffuser tested in the field as per International Electrotechnical Commission (IEC) standards and results presented in the form of power curves. The prediction of annual energy production for both wind turbines determined as per IEC standards.

Dynamic Analysis of a Mode I Propagating Crack Subjected to a Concentrated Load

2003 ◽  
Vol 70 (5) ◽  
pp. 668-675
Author(s):  
Y.-L. Chung ◽  
M.-R. Chen
Keyword(s):  
Stress Intensity ◽  
Wave Speed ◽  
Complete Solution ◽  
Crack Tip ◽  
Dynamic Effect ◽  
Mode I ◽  
S Wave ◽  
Dynamic Stress Intensity Factors ◽  
Concentrated Load ◽  
Self Similar

This work investigates the phenomenon of mode I central crack propagating with a constant speed subjected to a concentrated load on the crack surfaces. This problem is not a self-similar problem. However, the method of self-similar potential (SSP) in conjunction with superposition can be successfully applied if the time delay and the origin shift are considered. After the complete solution is obtained, attention is stressed on the dynamic stress intensity factors (DSIFs). Analytical results indicate that the DSIF equals the static stress intensity factor if the crack-tip speed is very slow and equal to zero if the crack-tip velocity approaches the Rayleigh-wave speed. However, the dynamic effect becomes obvious only if the crack-tip speed is 0.4 times faster than the S-wave speed. Moreover, the combination of SSP method and the superposition scheme can be applied to the expanding uniformly distributed load acting on a portion of the crack surfaces.

A low complexity shortest path tree restoration scheme for IP networks

2010 ◽  
Vol 14 (6) ◽  
pp. 566-568 ◽  
Author(s):  
Huan Chen ◽  
Po-Kai Tseng
Keyword(s):  
Shortest Path ◽  
Low Complexity ◽  
Ip Networks ◽  
Shortest Path Tree ◽  
Restoration Scheme

scholarly journals Rapid coral mortality following unusually calm and hot conditions on Iriomote, Japan

F1000Research ◽  
2018 ◽  
Vol 6 ◽  
pp. 1728 ◽  
Author(s):  
Andrew H Baird ◽  
Sally A. Keith ◽  
Erika Woolsey ◽  
Ryuta Yoshida ◽  
Tohru Naruse
Keyword(s):  
Water Movement ◽  
Sea Surface ◽  
Bleaching Event ◽  
Coral Mortality ◽  
Average Wind Speed ◽  
Common Cause ◽  
Wind Speeds ◽  
Average Wind ◽  
The Mean ◽  
Low Wind Speeds

Coral bleaching can be induced by many different stressors, however, the most common cause of mass bleaching in the field is higher than average sea surface temperatures (SST). Here, we describe an unusual bleaching event that followed very calm sea conditions combined with higher than average SST. Patterns of mortality differed from typical bleaching in four ways: 1) mortality was very rapid; 2) a different suite of species were most affected; 3) tissue mortality in Acropora spp. was often restricted to the center of the colony; 4) the event occurred early in summer. The two weeks prior to the event included 8 days where the average wind speed was less than 3 ms-1. In addition, SSTs in the weeks preceding and during the event were 1.0-1.5°C higher than the mean for the last 30 years. We hypothesize that this unusual bleaching event was caused by anoxia resulting from a lack of water movement induced by low wind speeds combined with high SST.

scholarly journals A Fissile Ripple Spreading Algorithm to Solve Time-Dependent Vehicle Routing Problem via Coevolutionary Path Optimization

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Wen Xu ◽  
JiaJun Li
Keyword(s):  
Vehicle Routing ◽  
Shortest Path ◽  
Traffic Congestion ◽  
Path Optimization ◽  
Time Dependent ◽  
Optimization Approach ◽  
Routing Problem ◽  
Shortest Path Problems ◽  
Travelling Time ◽  
Logistics Delivery

The time-dependent vehicle routing problems have lately received great attention for logistics companies due to their crucial roles in reducing the time and economic costs, as well as fuel consumption and carbon emissions. However, the dynamic routing environment and traffic congestions have made it challenging to make the actual travelling trajectory optimal during the delivery process. To overcome this challenge, this study proposed an unconventional path optimization approach, fissile ripple spreading algorithm (FRSA), which is based on the advanced structure of coevolutionary path optimization (CEPO). The objective of the proposed model is to minimize the travelling time and path length of the vehicle, which are the popular indicators in path optimization. Some significant factors usually ignored in other research are considered in this study, such as congestion evolution, routing environment dynamics, signal control, and the complicated correlation between delivery sequence and the shortest path. The effectiveness of the proposed approach was demonstrated well in two sets of simulated experiments. The results prove that the proposed FRSA can scientifically find out the optimal delivery trajectory in a single run via global research, effectively avoid traffic congestion, and decrease the total delivery costs. This finding paves a new way to explore a promising methodology for addressing the delivery sequence and the shortest path problems at the same time. This study can provide theoretical support for the practical application in logistics delivery.

scholarly journals Formation and distribution of sea-surface microlayers

2010 ◽  
Vol 7 (4) ◽  
pp. 5719-5755 ◽  
Author(s):  
O. Wurl ◽  
E. Wurl ◽  
L. Miller ◽  
K. Johnson ◽  
S. Vagle
Keyword(s):  
Wind Speed ◽  
Primary Production ◽  
Sea Surface ◽  
Surface Microlayer ◽  
Average Wind Speed ◽  
Wind Speeds ◽  
Average Wind ◽  
The Pacific ◽  
Sea Surface Microlayer ◽  
Natural Surfactants

Abstract. Results from a study of surfactants in the sea-surface microlayer (SML) in different regions of the ocean (subtropical, temperate, polar) suggest that this interfacial layer between the ocean and atmosphere covers the ocean's surface to a significant extent. Threshold values at which primary production acts as a significant source of natural surfactants have been derived from the enrichment of surfactants in the SML relative to underlying water and local primary production. Similarly, we have also derived a wind speed threshold at which the SML is disrupted. The results suggest that surfactant enrichment in the SML is typically greater in oligotrophic regions of the ocean than in more productive waters. Furthermore, the enrichment of surfactants persisted at wind speeds of up to 10 m s−1 without any observed depletion above 5 m s−1. This suggests that the SML is stable enough to exist even at the global average wind speed of 6.6 m s−1. Global maps of primary production and wind speed are used to estimate the ocean's SML coverage. The maps indicate that wide regions of the Pacific and Atlantic Oceans between 30° N and 30° S are more significantly affected by the SML than northern of 30° N and southern of 30° S due to higher productivity (spring/summer blooms) and wind speeds exceeding 12 m s−1 respectively.

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