Yanqiu Chen, Xiaodong Zhou, Taolin Zhang, Zhijian Fu, Yuqi Hu and Lizhong Yang
– The purpose of this paper is to study the behavior of smoke flow in building fires and optimize the design of smoke control systems.
Abstract
Purpose
The purpose of this paper is to study the behavior of smoke flow in building fires and optimize the design of smoke control systems.
Design/methodology/approach
A total of 435 3-D fire simulations were conducted through NIST fire dynamics simulator to analyze thermal behavior of combined buoyancy-induced and pressure-driven smoke flow in complex vertical shafts, under consideration of influence of heat release rate (HRR) and locations of heat sources. This influence was evaluated through neutral pressure plane (NPP), which is a critical plane depicting the flow velocity distributions. Hot smoke flows out of shafts beyond the NPP and cold air flows into shafts below the NPP.
Findings
Numerical simulation results show that HRR of heat source has little influence on NPP, while location of heat source can make a significant difference to NPP, particularly in cases of multi-heat source. Identifying the location of NPP helps to develop a more effective way to control the smoke with less energy consumption. Through putting an emphasis on smoke exhausting beyond the NPP and air supplying below the NPP, the smoke control systems can make the best use of energy.
Research limitations/implications
Because of the chosen research approach, the research results may need to be tested by further experiments.
Practical implications
The paper includes implications for the optimization of smoke control systems design in buildings.
Originality/value
This paper fulfills an identified need to research the behavior of hot smoke in building fires and optimize the design of smoke control systems.
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Zhe Liu, Zhijian Qiao, Chuanzhe Suo, Yingtian Liu and Kefan Jin
This paper aims to study the localization problem for autonomous industrial vehicles in the complex industrial environments. Aiming for practical applications, the pursuit is to…
Abstract
Purpose
This paper aims to study the localization problem for autonomous industrial vehicles in the complex industrial environments. Aiming for practical applications, the pursuit is to build a map-less localization system which can be used in the presence of dynamic obstacles, short-term and long-term environment changes.
Design/methodology/approach
The proposed system contains four main modules, including long-term place graph updating, global localization and re-localization, location tracking and pose registration. The first two modules fully exploit the deep-learning based three-dimensional point cloud learning techniques to achieve the map-less global localization task in large-scale environment. The location tracking module implements the particle filter framework with a newly designed perception model to track the vehicle location during movements. Finally, the pose registration module uses visual information to exclude the influence of dynamic obstacles and short-term changes and further introduces point cloud registration network to estimate the accurate vehicle pose.
Findings
Comprehensive experiments in real industrial environments demonstrate the effectiveness, robustness and practical applicability of the map-less localization approach.
Practical implications
This paper provides comprehensive experiments in real industrial environments.
Originality/value
The system can be used in the practical automated industrial vehicles for long-term localization tasks. The dynamic objects, short-/long-term environment changes and hardware limitations of industrial vehicles are all considered in the system design. Thus, this work moves a big step toward achieving real implementations of the autonomous localization in practical industrial scenarios.
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The purpose of the paper is to analyse the characteristics, development and implementation of the Chinese labour arbitration system and its role in settling labour disputes.
Abstract
Purpose
The purpose of the paper is to analyse the characteristics, development and implementation of the Chinese labour arbitration system and its role in settling labour disputes.
Design/methodology/approach
The paper analyses official statistics and the arbitral cases published on the web sites of government labour and social security departments.
Findings
The paper finds that labour arbitration has become the most important mechanism for settling labour disputes in China since the middle 1990s. This trend indicates the fading of traditional political and administrative means due to the decreasing influence of governmental labour administration and the subordinate status of trade unions, and the emergence of the rule of law in setting labour terms. The effectiveness and fairness of labour arbitration is to a certain extent constrained by its limitations and workers' weak position in employment relations that prohibit it from fully upholding the Labour Law.
Research limitations
The paper shows that there is a paucity of literature devoted to labour arbitration in China. Further research is necessary to study labour arbitration, particularly the issues concerning: the frequency and reasons for workers to compromise in demands when claims, especially unfair dismissal cases; the process and the way in which arbitrators handle cases and make decisions; the fairness of arbitration awards; and the ways for improving competency and neutrality of arbitrators and arbitration committees.
Practical implications
The paper shows that the party‐appointed method is necessary to improve the two parties' control of arbitration process. The public should be allowed to access to case and arbitrator related information in order to increase the transparency of arbitration.
Originality/value
This is the first paper that introduces the labour arbitration system in China and analyzes its role in setting labour disputes and its potential for improvement.
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Zhai Longzhen and ShaoHong Feng
The rapid evacuation of personnel in emergency situations is of great significance to the safety of pedestrians. In order to further improve the evacuation efficiency in emergency…
Abstract
Purpose
The rapid evacuation of personnel in emergency situations is of great significance to the safety of pedestrians. In order to further improve the evacuation efficiency in emergency situations, this paper proposes a pedestrian evacuation model based on improved cellular automata based on microscopic features.
Design/methodology/approach
First, the space is divided into finer grids, so that a single pedestrian occupies multiple grids to show the microscopic behavior between pedestrians. Second, to simulate the velocity of pedestrian movement under different personnel density, a dynamic grid velocity model is designed to establish a linear correspondence relationship with the density of people in the surrounding environment. Finally, the pedestrian dynamic exit selection mechanism is established to simulate the pedestrian dynamic exit selection process.
Findings
The proposed method is applied to single-exit space evacuation, multi-exit space evacuation, and space evacuation with obstacles, respectively. Average speed and personnel evacuation decisions are analyzed in specific applications. The method proposed in this paper can provide the optimal evacuation plan for pedestrians in multiple exit and obstacle environments.
Practical implications/Social implications
In fire and emergency situations, the method proposed in this paper can provide a more effective evacuation strategy for pedestrians. The method proposed in this paper can quickly get pedestrians out of the dangerous area and provide a certain reference value for the stable development of society.
Originality/value
This paper proposes a cellular automata pedestrian evacuation method based on a fine grid velocity model. This method can more realistically simulate the microscopic behavior of pedestrians. The proposed model increases the speed of pedestrian movement, allowing pedestrians to dynamically adjust the speed according to the specific situation.
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Jiang Zhao, Ksenia Gerasimova, Yala Peng and Jiping Sheng
The purpose of this paper is to discuss characteristics of organic food value chain governance and policy tools that can increase the supply of good quality of agri-products.
Abstract
Purpose
The purpose of this paper is to discuss characteristics of organic food value chain governance and policy tools that can increase the supply of good quality of agri-products.
Design/methodology/approach
This paper discusses a national organic food supply system in China, identifying the link between an organization form with a social confidence crisis and information asymmetry as the main challenges. It develops an analytical model of the market structure of organic certification based on the contract theory, which considers the certification incentive driven by both farmers and processors. Two cases of raw milk producers and processors provide empirical data.
Findings
The argument which is brought forward is that product information asymmetry together with strict requirement for ensuring organic food integrity brings the organic milk value chain into a highly integrated organization pattern. A tight value chain is effective in the governance of organic food supply chain under third party certification (TPC), while a loose value chain discourages producing organic products because of transaction costs. TPC is found to be a positively correlation with a tight value chain, but it brings high organizational cost and it raises cost for consumers.
Originality/value
This is the first paper discussing the governance of organic food value chain in Chinese milk industry.