A Hierarchical Semantic Map for Large-scale Outdoor Environment

2021 ◽  
Author(s):  
Di Zhang ◽  
De Xu
Keyword(s):  
Large Scale ◽  
Outdoor Environment ◽  
Semantic Map

scholarly journals A Portable Direct Methanol Fuel Cell Power Station for Long-Term Internet of Things Applications

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3547
Author(s):  
Chung-Jen Chou ◽  
Shyh-Biau Jiang ◽  
Tse-Liang Yeh ◽  
Li-Duan Tsai ◽  
Ku-Yen Kang ◽  
...  
Keyword(s):  
Power Generation ◽  
Fuel Cell ◽  
Internet Of Things ◽  
Direct Methanol Fuel Cell ◽  
Large Scale ◽  
Outdoor Environment ◽  
Power Station ◽  
Direct Methanol ◽  
Methanol Fuel Cell

With regard to the best electro-chemical efficiency of an active direct methanol fuel cell (DMFC), the stacks and their balance of plant (BOP) are complex to build and operate. The yield of making the large-scale stacks is difficult to improve. Therefore, a portable power station made of multiple simpler planar type stack modules with only appropriate semi-active BOPs was developed. A planar stack and its miniature BOP components are integrated into a semi-active DMFC stack module for easy production, assembly, and operation. An improved energy management system is designed to control multiple DMFC stack modules in parallel to enhance its power-generation capacity and stability so that the portability, environmental tolerance, and long-term durability become comparable to that of the active systems. A prototype of the power station was tested for 3600 h in an actual outdoor environment through winter and summer. Its performance and maintenance events are analyzed to validate its stability and durability. Throughout the test, it maintained the daily average of 3.3 W power generation with peak output driving capability of 12 W suitable for Internet of Things (IoT) applications.

Numerical Simulation of Natural Ventilation in Large-Scale Industrial Workshops Based on Orthogonal Test Design

2013 ◽  
Author(s):  
Yan Long ◽  
Jinming Feng ◽  
Ke Liu ◽  
Shiping Jin ◽  
Yan Fu
Keyword(s):  
Heat Source ◽  
Large Scale ◽  
Natural Ventilation ◽  
Orthogonal Test ◽  
Outdoor Environment ◽  
Industrial Plant ◽  
Test Design ◽  
Range Analysis ◽  
Orthogonal Test Design ◽  
Cfd Method

In this paper, orthogonal test design method and the CFD method were used to study the different building envelopes, and the outdoor environment of natural ventilation effect of single span of high temperature industrial workshop. Firstly, 18 ventilation models of workshop with heat source were constructed with orthogonal test design. Secondly, 18 ventilation models of workshop with heat source were simulated with CFD method. Finally, the order of the influencing factors on the ventilation of workshop was obtained through multiple index range analysis of the orthogonal experiment results according to the average temperature inside the workshop. Then the optimal combination of the best ventilation effect was selected. The research results can provide effectively theoretical basis for the future industrial plant ventilation design and optimization.

scholarly journals Lexical diachronic semantic maps

2021 ◽  
Vol 11 (3) ◽  
pp. 367-420 ◽  
Author(s):  
Thanasis Georgakopoulos ◽  
Stéphane Polis
Keyword(s):  
Large Scale ◽  
Historical Linguistics ◽  
Qualitative Evaluation ◽  
Ancient Greek ◽  
Semantic Map ◽  
Semantic Extension ◽  
Ancient Egyptian ◽  
Semantic Maps ◽  
Scope Of Application

Abstract This paper extends the scope of application of the semantic map model to diachronic lexical semantics. Combining a quantitative approach to large-scale synchronic polysemy data with a qualitative evaluation of the diachronic material in two text languages, ancient Egyptian and ancient Greek, it shows that weighted diachronic semantic maps can capture informative generalizations about the organization of the lexicon and its reshaping over time. The general methodology developed in the paper is illustrated with a case study of the semantic extension of time-related lexemes. This case study shows that the blend of tools well established in linguistic typology with proven methods of historical linguistics enables a principled approach to long-standing questions in the fields of diachronic semasiology and onomasiology.

scholarly journals Video Analysis of Pedestrian Movement (VAPM) under Different Lighting Conditions—Method Exploration

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4141
Author(s):  
Maria Johansson ◽  
Aliaksei Laureshyn ◽  
Mikael Nilsson
Keyword(s):  
Video Analysis ◽  
Smart City ◽  
Large Scale ◽  
Outdoor Environment ◽  
Energy Usage ◽  
Pedestrian Movement ◽  
Lighting Conditions ◽  
Methodological Triangulation ◽  
Lighting Systems ◽  
New City

When daylight hours are limited, pedestrians are dependent on appropriate outdoor lighting. Although new city lighting applications must consider both energy usage and pedestrian responses, current methods used to capture pedestrian walking behaviour during dark conditions in real settings are limited. This study reports on the development and evaluation of a video-based method that analyses pedestrians’ microscopic movements (VAPM—video analysis of pedestrian movements), including placement and speed, in an artificially lit outdoor environment. In a field study utilising between-subjects design, 62 pedestrians walked along the same path under two different lighting applications. VAPM accurately discriminated pedestrians’ microscopic movements in the two lighting applications. By incorporating methodological triangulation, VAPM successfully complemented observer-based assessments of pedestrians’ perceptions and evaluations of the two lighting applications. It is suggested that in evaluations of pedestrian responses to city lighting applications, observer-based assessments could be successfully combined with an analysis of actual pedestrian movement while walking in the lit environment. However, prior to employing a large-scale application of VAPM, the methodology needs to be further adapted for use with drones and integration into smart city lighting systems.

Numerical study of external explosion characteristics induced by indoor natural gas vented explosion

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Lei Pang ◽  
Qianran Hu ◽  
Kai Yang
Keyword(s):  
Natural Gas ◽  
Design Methodology ◽  
Large Scale ◽  
Numerical Study ◽  
Outdoor Environment ◽  
Gas Explosion ◽  
Content Type ◽  
Gas Explosions ◽  
Explosion Overpressure ◽  
Vented Explosion

Purpose The purpose of this paper is to ascertain the harm to personnel and equipment caused by an external explosion during natural gas explosion venting. The external explosion characteristics induced by the indoor natural gas explosion are the focal points of the investigation. Design/methodology/approach Computational fluid dynamics technology was used to investigate the large-scale explosion venting process of natural gas in a 6 × 3 × 2.5 m room, and the characteristics of external explosion under different scaled vent size (Kv = Av/V2/3, 0.05, 0.08, 0.13, 0.18) were numerically analyzed. Findings When Kv = 0.08, the length and duration of the explosion fireball are 13.39 and 450 ms, respectively, which significantly expands the degree and range of high-temperature hazards. The suitable flow-field structure causes the external explosion overpressure to be more than twice that indoors, i.e. the natural gas explosion venting overpressure may be considerably more hazardous in an outdoor environment than inside a room. A specific range for the Kv can promote the superposition of outdoor rupture waves and explosion shock waves, thereby creating a new overpressure hazard. Originality/value Little attention has been devoted to investigating systematically the external explosion hazards. Based on the numerical simulation and the analysis, the external explosion characteristics induced by the indoor large-scale gas explosion were obtained. The research results are theoretically significant for mitigating the effects of external gas explosions on personnel and equipment.

3D Pointing Gestures as Target Selection Tools for Monocular UAVs

2020 ◽  
Author(s):  
Anna C S Medeiros ◽  
Photchara Ratsamee ◽  
Jason Orlosky ◽  
Yuki Uranishi ◽  
Manabu Higashida ◽  
...  
Keyword(s):  
Large Scale ◽  
Target Selection ◽  
Outdoor Environment ◽  
Depth Information ◽  
Multiple Objects ◽  
First Response ◽  
Elicitation Study ◽  
Pointing Gestures ◽  
Emergency Scenarios ◽  
Pointing Gesture

Abstract Firefighters need to gain information from both inside and outside of buildings in first response emergency scenarios. For this purpose, drones are beneficial. This paper presents an elicitation study that showed the firefighters' desire to collaborate with autonomous drones. We developed a Human-Drone Interaction (HDI) method for indicating a target to a drone using 3D pointing gestures estimated solely from a monocular camera. The participant first points to a window without using any wearable or body-attached device. Through the drone's front-facing camera, the drone detects the gesture and computes the target window. This work includes a description of the process for choosing the gesture, detecting and localizing objects, and carrying out the transformations between coordinate systems. Our proposed 3D pointing gesture improves a 2D pointing gesture interface by integrating depth information with SLAM, solving multiple objects aligned on the same plane ambiguity, in a large-scale outdoor environment. Experimental results showed that our 3D pointing gesture interface obtained a 0.85 and 0.73 F1-Score on average in simulation and real-world experiments and 0.58 F1-Score at the maximum distance of 25 meters between drone and building.

Building of cognizing semantic map in large-scale semi-unknown environment

2014 ◽  
Vol 21 (5) ◽  
pp. 1804-1815
Author(s):  
Hao Wu ◽  
Guo-hui Tian ◽  
Yan Li ◽  
Sen Sang ◽  
Hai-ting Zhang
Keyword(s):  
Large Scale ◽  
Semantic Map ◽  
Unknown Environment

An automated assembly technology for large mobile radar antenna

2016 ◽  
Vol 36 (4) ◽  
pp. 429-438 ◽  
Author(s):  
Gaoliang Peng ◽  
Yu Sun ◽  
Rui Han ◽  
Chuanhao Li
Keyword(s):  
Large Scale ◽  
Outdoor Environment ◽  
Automatic Assembly ◽  
Accurate Identification ◽  
Content Type ◽  
Operation Conditions ◽  
Assembly Technology ◽  
Three Degree Of Freedom ◽  
Radar Antenna ◽  
Lifting Equipment

Purpose Large-scale mobile radars are still erected manually by using lifting equipment, which often fails to meet the requirements on precision, quality and efficiency in the erecting process. This paper aims to introduce techniques for automatic assembly of large mobile radar antenna. Design/methodology/approach A large-scale metrology system for accurate identification of the positions and orientation of the radar antenna components is presented. A novel three-degree-of-freedom parallel mechanism is designed to realize orientation adjustment of three axes synchronous, and, thus guarantees the efficiency and accuracy of positioning process. Findings The system described in this paper is practicable in outdoor environment and provides a holistic solution that gives full consideration of the operation conditions and the environmental influences. In performance evaluation tests, the measured absolute accuracy is less than ±1 mm and repeatability is less than ±0.5 mm in the positioning task for 10 × 3 m large antenna. Originality/value This paper presents a new concept of an automatic assembly technology for the large radar antenna application.

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