scholarly journals Study on the Steepness of Landslide-Induced Wave and Nonlinear Motion of Container Ships

2020 ◽  
Vol 10 (6) ◽  
pp. 2159
Author(s):  
Peiyin Yuan ◽  
Pingyi Wang ◽  
Yu Zhao
Keyword(s):  
High Speed ◽  
Large Scale ◽  
Design Method ◽  
Slope Angle ◽  
Volume Effect ◽  
Water Area ◽  
Three Gorges Reservoir Area ◽  
Orthogonal Experimental Design ◽  
Landslide Volume ◽  
Ship Rolling

Large-scale instability of a landslide body, sliding down a bank slope and entering water at a high speed, arouses landslide surges. Taking the water entry point as a source point, they spread rapidly to surrounding areas, increasing the danger risk of vessel passages in the water area. In this paper, adopting an orthogonal experimental design method, based on the test data, the Three Gorges Reservoir area was derived in order to calculate the height of the first wave of the bank landslide surge: to analyze the slope angle, the geological environment, the volume of the landslide surge, and the landslide surge wave steepness; to study the landslide volume effect on ship rolling and the swaying motion rule; and to explore the landslide surge in different ship rolling positions and transverse oscillation characteristics. This study can provide theoretical support for the navigation safety of ships in landslide surge waters.

scholarly journals Dense-RefineDet for Traffic Sign Detection and Classification

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6570
Author(s):  
Chang Sun ◽  
Yibo Ai ◽  
Sheng Wang ◽  
Weidong Zhang
Keyword(s):  
High Speed ◽  
Large Scale ◽  
Design Method ◽  
Contextual Information ◽  
Real Life ◽  
Single Shot ◽  
Traffic Sign ◽  
Traffic Signs ◽  
High Level ◽  
Anchor Design

Detecting and classifying real-life small traffic signs from large input images is difficult due to their occupying fewer pixels relative to larger targets. To address this challenge, we proposed a deep-learning-based model (Dense-RefineDet) that applies a single-shot, object-detection framework (RefineDet) to maintain a suitable accuracy–speed trade-off. We constructed a dense connection-related transfer-connection block to combine high-level feature layers with low-level feature layers to optimize the use of the higher layers to obtain additional contextual information. Additionally, we presented an anchor-design method to provide suitable anchors for detecting small traffic signs. Experiments using the Tsinghua-Tencent 100K dataset demonstrated that Dense-RefineDet achieved competitive accuracy at high-speed detection (0.13 s/frame) of small-, medium-, and large-scale traffic signs (recall: 84.3%, 95.2%, and 92.6%; precision: 83.9%, 95.6%, and 94.0%). Moreover, experiments using the Caltech pedestrian dataset indicated that the miss rate of Dense-RefineDet was 54.03% (pedestrian height > 20 pixels), which outperformed other state-of-the-art methods.

Dynamic Analysis and Design Method Study on the Combined-Boom System of Portal Crane

2012 ◽  
Vol 152-154 ◽  
pp. 1645-1649 ◽  
Author(s):  
Yuan Tao Sun ◽  
Duan Li
Keyword(s):  
High Speed ◽  
Large Scale ◽  
Design Method ◽  
Time History ◽  
Analysis Method ◽  
Drive Power ◽  
Analysis And Design ◽  
Whole Process ◽  
Handling Device ◽  
Portal Crane

As a main handling device the portal crane is widely used in port, railroad, etc.The crane handling procedure is mainly carried out through its combined-boom system luffing or swing .In general, in order to reduce drive power and improve the operational performance, the luffing trajectory should meet the design requirement. At the same time, structure stress should be secured in the whole process of handling the cargo. Recently, to deal with more heaver and further cargo, the portal crane is becoming more large-scale. So that the large-scale components such as jib elastic deformation effect on large displacement motion cannot be ignored longer. In addition to the structure high speed motion in the process of handling also make the structure dynamic behaviors spending more obvious specially in the condition of luffing combined with swing. However, the problem for this dynamic behavior brings about to physical design sometimes has no method to solve according to the conventional analysis algorithm and dynamics method. To reduce the deviation caused by the common analysis, design and analysis method based on the multibody is put forward in this thesis. According to the method, the result on the luffing trajectory and stress-time history are analyzed easily. So that it ensure the efficiency and increase the accuracy of the initial design according to the conventional design and analysis method.

scholarly journals Design of large-scale streamlined head cars of high-speed trains and aerodynamic drag calculation

2017 ◽  
Vol 44 (4) ◽  
pp. 89-97 ◽  
Author(s):  
Zhenfeng Wu ◽  
Enyu Yang ◽  
Wangcai Ding
Keyword(s):  
High Speed ◽  
Large Scale ◽  
Production Control ◽  
Aerodynamic Drag ◽  
Design Method ◽  
Control Point ◽  
Surface Characteristics ◽  
High Speed Train ◽  
Research Subjects ◽  
High Speed Trains

Aerodynamic drag plays an important role in high-speed trains, and how to reduce the aerodynamic drag is one of the most important research subjects related to modern railway systems. This paper investigates a design method for large-scale streamlined head cars of high-speed trains by adopting NURBS theory according to the outer surface characteristics of trains. This method first created the main control lines of the driver cab by inputting control point coordinates; then, auxiliary control lines were added to the main ones. Finally, the reticular region formed by the main control lines and auxiliary ones were filled. The head car was assembled with the driver cab and sightseeing car in a virtual environment. The numerical simulation of train flow field was completed through definition of geometric models, boundary conditions, and space discretization. The calculation results show that the aerodynamic drag of the high-speed train with large-scale streamlined head car decreases by approximately 49.3% within the 50-300 km/h speed range compared with that of the quasi-streamlined high-speed train. This study reveals that the high-speed train with large-scale streamlined head car could achieve the purpose of reducing running aerodynamic drag and saving energy, and aims to provide technical support for the subsequent process design and production control of high-speed train head cars.

Validation of the Deep Patch Embankment Repair Design Method using a Large-Scale Centrifuge

2018 ◽  
Vol 2672 (52) ◽  
pp. 142-151
Author(s):  
Eli V. Cuelho ◽  
Steven W. Perkins ◽  
Brian M. Collins
Keyword(s):  
Phase I ◽  
Large Scale ◽  
Design Method ◽  
Slope Angle ◽  
Design Procedure ◽  
Design Tool ◽  
Patch Repair ◽  
Slope Failures ◽  
Lagrangian Analysis ◽  
Layer Spacing

The deep patch repair technique has been widely used in the western U.S.A. to address subsidence and shallow slope failures mainly within poorly performing side-cast embankments and natural slopes consisting of weak soils overlying stronger soils. This project was a multi-phase effort to examine, refine, update, and verify the design procedure associated with this repair method. An experimental design was developed to examine the performance of various deep patch repair configurations and to validate the design technique developed using FLAC (Fast Lagrangian Analysis of Continua) modeling results during Phase I. A series of unreinforced and reinforced slope configurations were tested using a large centrifuge to study their behavior and document their performance. Fourteen centrifuge models (seven unreinforced and seven deep patch reinforced) were run to verify the design chart for a 39-degree slope angle and having one-foot thick deep patch layer spacing (one of four design charts developed during Phase I). Performance of the deep patch models was evaluated based on a serviceability criterion limiting movement in the road bench atop the reinforced zone. Models reinforced with deep patches helped stabilize slope failures by acting as a cantilever and redirecting the failure path to the face of the slope beneath the slope crest, thereby reducing distresses near the top surface of the deep patch. Overall, results from this analysis indicated that the design tool created during Phase I sufficiently predicts the depth of the deep patch necessary to achieve good performance.

Do elite soccer players cover longer distance when losing? Differences between attackers and defenders

2020 ◽  
pp. 174795412098227
Author(s):  
Carlos Lago-Peñas ◽  
Anton Kalén ◽  
Miguel Lorenzo-Martinez ◽  
Roberto López-Del Campo ◽  
Ricardo Resta ◽  
...  
Keyword(s):  
New York ◽  
High Speed ◽  
Large Scale ◽  
Tracking System ◽  
Soccer Players ◽  
Running Performance ◽  
Situational Variables ◽  
Total Distance ◽  
Professional Soccer ◽  
Score Line

This study aimed to evaluate the effects playing position, match location (home or away), quality of opposition (strong or weak), effective playing time (total time minus stoppages), and score-line on physical match performance in professional soccer players using a large-scale analysis. A total of 10,739 individual match observations of outfield players competing in the Spanish La Liga during the 2018–2019 season were recorded using a computerized tracking system (TRACAB, Chyronhego, New York, USA). The players were classified into five positions (central defenders, players = 94; external defenders, players = 82; central midfielders, players = 101; external midfielders, players = 72; and forwards, players = 67) and the following match running performance categories were considered: total distance covered, low-speed running (LSR) distance (0–14 km · h−1), medium-speed running (MSR) distance (14–21 km · h−1), high-speed running (HSR) distance (>21 km · h−1), very HSR (VHSR) distance (21–24 km · h−1), sprint distance (>24 km · h−1) Overall, match running performance was highly dependent on situational variables, especially the score-line condition (winning, drawing, losing). Moreover, the score-line affected players running performance differently depending on their playing position. Losing status increased the total distance and the distance covered at MSR, HSR, VHSR and Sprint by defenders, while attacking players showed the opposite trend. These findings may help coaches and managers to better understand the effects of situational variables on physical performance in La Liga and could be used to develop a model for predicting the physical activity profile in competition.

scholarly journals Design of a Variable-Stiffness Compliant Skin for a Morphing Leading Edge

2021 ◽  
Vol 11 (7) ◽  
pp. 3165
Author(s):  
Zhigang Wang ◽  
Yu Yang
Keyword(s):  
Composite Laminate ◽  
Large Scale ◽  
Design Method ◽  
Leading Edge ◽  
Variable Stiffness ◽  
Manufacturing Constraints ◽  
Aircraft Wing ◽  
Noise Abatement ◽  
Civil Aircraft ◽  
Final Profile

A seamless and smooth morphing leading edge has remarkable potential for noise abatement and drag reduction of civil aircraft. Variable-stiffness compliant skin based on tailored composite laminate is a concept with great potential for morphing leading edge, but the currently proposed methods have difficulty in taking the manufacturing constraints or layup sequence into account during the optimization process. This paper proposes an innovative two-step design method for a variable-stiffness compliant skin of a morphing leading edge, which includes layup optimization and layup adjustment. The combination of these two steps can not only improve the deformation accuracy of the final profile of the compliant skin but also easily and effectively determine the layup sequence of the composite layup. With the design framework, an optimization model is created for a variable-stiffness compliant skin, and an adjustment method for its layups is presented. Finally, the deformed profiles between the directly optimized layups and the adjusted ones are compared to verify its morphing ability and accuracy. The final results demonstrate that the obtained deforming ability and accuracy are suitable for a large-scale aircraft wing.

scholarly journals 1.5 °C degrowth scenarios suggest the need for new mitigation pathways

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lorenz T. Keyßer ◽  
Manfred Lenzen
Keyword(s):  
Technological Change ◽  
High Speed ◽  
Large Scale ◽  
High Energy ◽  
Climate Mitigation ◽  
Intergovernmental Panel ◽  
Economic Output ◽  
Integrated Assessment Modelling ◽  
Negative Emissions ◽  
Energy Emissions

Abstract1.5  °C scenarios reported by the Intergovernmental Panel on Climate Change (IPCC) rely on combinations of controversial negative emissions and unprecedented technological change, while assuming continued growth in gross domestic product (GDP). Thus far, the integrated assessment modelling community and the IPCC have neglected to consider degrowth scenarios, where economic output declines due to stringent climate mitigation. Hence, their potential to avoid reliance on negative emissions and speculative rates of technological change remains unexplored. As a first step to address this gap, this paper compares 1.5  °C degrowth scenarios with IPCC archetype scenarios, using a simplified quantitative representation of the fuel-energy-emissions nexus. Here we find that the degrowth scenarios minimize many key risks for feasibility and sustainability compared to technology-driven pathways, such as the reliance on high energy-GDP decoupling, large-scale carbon dioxide removal and large-scale and high-speed renewable energy transformation. However, substantial challenges remain regarding political feasibility. Nevertheless, degrowth pathways should be thoroughly considered.

scholarly journals Optimal Design of Novel Blade Profile for Savonius Wind Turbines

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3484
Author(s):  
Tai-Lin Chang ◽  
Shun-Feng Tsai ◽  
Chun-Lung Chen
Keyword(s):  
Wind Energy ◽  
Drag Force ◽  
Wind Turbines ◽  
Rural Areas ◽  
Large Scale ◽  
Design Method ◽  
Angular Position ◽  
Vertical Axis ◽  
Blade Profile ◽  
Main Concept

Since the affirming of global warming, most wind energy projects have focused on the large-scale Horizontal Axis Wind Turbines (HAWTs). In recent years, the fast-growing wind energy sector and the demand for smarter grids have led to the use of Vertical Axis Wind Turbines (VAWTs) for decentralized energy generation systems, both in urban and remote rural areas. The goals of this study are to improve the Savonius-type VAWT’s efficiency and oscillation. The main concept is to redesign a Novel Blade profile using the Taguchi Robust Design Method and the ANSYS-Fluent simulation package. The convex contour of the blade faces against the wind, creating sufficient lift force and minimizing drag force; the concave contour faces up to the wind, improving or maintaining the drag force. The result is that the Novel Blade improves blade performance by 65% over the Savonius type at the best angular position. In addition, it decreases the oscillation and noise accordingly. This study achieved its two goals.

scholarly journals Prevention of Mountain Disasters and Maintenance of Residential Area through Real-Time Terrain Rendering

2021 ◽  
Vol 13 (5) ◽  
pp. 2950
Author(s):  
Su-Kyung Sung ◽  
Eun-Seok Lee ◽  
Byeong-Seok Shin
Keyword(s):  
Real Time ◽  
Graphics Processing Units ◽  
High Speed ◽  
Large Scale ◽  
Civil Engineering ◽  
Three Dimensional ◽  
Sampled Data ◽  
Residential Areas ◽  
Terrain Rendering ◽  
Mountain Disasters

Climate change increases the frequency of localized heavy rains and typhoons. As a result, mountain disasters, such as landslides and earthworks, continue to occur, causing damage to roads and residential areas downstream. Moreover, large-scale civil engineering works, including dam construction, cause rapid changes in the terrain, which harm the stability of residential areas. Disasters, such as landslides and earthenware, occur extensively, and there are limitations in the field of investigation; thus, there are many studies being conducted to model terrain geometrically and to observe changes in terrain according to external factors. However, conventional topography methods are expressed in a way that can only be interpreted by people with specialized knowledge. Therefore, there is a lack of consideration for three-dimensional visualization that helps non-experts understand. We need a way to express changes in terrain in real time and to make it intuitive for non-experts to understand. In conventional height-based terrain modeling and simulation, there is a problem in which some of the sampled data are irregularly distorted and do not show the exact terrain shape. The proposed method utilizes a hierarchical vertex cohesion map to correct inaccurately modeled terrain caused by uniform height sampling, and to compensate for geometric errors using Hausdorff distances, while not considering only the elevation difference of the terrain. The mesh reconstruction, which triangulates the three-vertex placed at each location and makes it the smallest unit of 3D model data, can be done at high speed on graphics processing units (GPUs). Our experiments confirm that it is possible to express changes in terrain accurately and quickly compared with existing methods. These functions can improve the sustainability of residential spaces by predicting the damage caused by mountainous disasters or civil engineering works around the city and make it easy for non-experts to understand.

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