Individual-based modelling of fishermen search behaviour with neural networks and reinforcement learning

A model to mimic the search behaviour of fishermen is built with two neural networks to cope with two separate decision-making processes in fishing activities. One neural network deals with decisions to stay or move to new fishing grounds and the other is constructed for the purpose of finding prey within the fishing areas. Some similarities with the behaviour of real fishermen are found: concentrated local search once a prey has been located to increase the probability of remaining near a prey patch and the straightforward movement to other fishing grounds. The artificial fisherman prefers areas near the port when conditions in different fishing grounds are similar or when there is high uncertainty in its world. In the latter case a reluctance to navigate to other areas is observed. The artificial fisherman selects areas with higher concentration of prey, even if they are far from the port of departure, unless a high uncertainty is related to the fishing ground. Connected areas are preferred and followed in orderly fashion if a higher catch is expected. The observed behaviour of the artificial fisherman in uncertain scenarios can be described as a risk-averse attitude. The approach seems appropriate for an individual-based modelling of fishery systems, focusing on the learning and adaptive characteristics of fishermen and on interactions that take place at a fine scale.     

Social dimensions of mining: Research,policy and practice challenges for the minerals industry in Australia

The social dimensions of the mining industry are increasingly acknowledged as critical to business success, yet remain the least understood aspect of the business concept of sustainable development—the ‘triple bottom line’ of economy, environment and society.     

Q235钢在火灾条件下的力学性能研究

在试验的基础上,对建筑中常用的Q235铜在火灾条件下的力学性能进行了研究,获得了Q235钢的屈服强度、极限强度、弹性模量、极限应变等力学性能随温度变化而变化的规律,并对影响Q235钢力学性能的因素进行了分析。     

高地应力条件下Q系统在某勘探洞围岩分类中的应用

西南地区某水电站勘探洞高地应力是一个突出问题,高地应力洞段岩体属于坚硬岩或较坚硬岩,主要破坏方式是岩爆。高地应力区非岩爆岩体中未见结构性流变和软岩塑性流动等变形破坏现象,岩体质量较好。通过对岩体质量分类Q系统在该勘探洞高地应力洞段的应用,发现Q系统对于高地应力区非岩爆段岩体没有给出相应的SRF值;岩爆的发育条件是多方面的,但Q系统对岩爆的发育条件考虑较单一,所以它在高地应力区岩爆段的分类结果不能准确地体现出岩爆的等级和围岩类别。基于这2个问题,本文对Q系统做了相应的修改,以适应该勘探洞围岩分类,从修改后Q系统的分类结果看,效果良好。     

Study of chest injuries to 3-year-old child occupants seated in impact shield and 5-point harness CRSs

Objective: The objective of this study was to investigate whether the 5-point harness or the impact shield child restraint system (CRS) or both have the potential to cause chest injuries to children. This is determined by examining whether the loading to the chest reaches the internal organ injury threshold for children.

Method: The chest injury risk to a child occupant in a CRS was investigated using Q3 dummy tests, finite element (FE) simulations (Q3 dummy and human models), and animal tests. The investigation was done for 2 types of CRSs (i.e., the impact shield CRS and 5-point harness CRS) based on the UN R44 dynamic test specifications.

Results: The tests using a Q3 dummy indicated that although the chest deflection of the dummy in the impact shield CRS was large, it was less than the injury threshold (40 mm). Computational biomechanics simulations (using finite element FE analysis) showed that the Q3 dummy's chest is loaded by the shield and deforms substantially under this load. To clarify whether chest injuries due to chest compression can occur with an impact shield or with the 5-point harness CRS, 7 experiments were performed using Tibetan miniature pigs with weights ranging from 9.7 to 13 kg. Severe chest and abdominal injuries (lung contusion, coronary artery laceration, liver laceration) were found in the tests using the impact shield CRS. No chest injuries were present when using the 5-point harness CRS.

Conclusion: When using the impact shield CRS, the chest deformed substantially in dummy tests and FE simulations, and chest and abdominal injuries were observed in pig tests. It is possible that these chest injuries could also occur to child occupants sitting in the impact shield CRS.     

Chinese resource security policies and the restructuring of the Asia-Pacific iron ore market

This paper reviews the restructuring of the Asia-Pacific iron ore market in the wake of the rise of the Chinese steel industry. Prior to the 2000s, this market was characterised by two key features—high firm-level concentration on both the producer and consumer sides, and price determination through annually negotiated benchmark pricing between Australian mining and Japanese steel firms. However, owing to rapid growth in the Chinese steel industry and its emergence as the region's principal iron ore consumer, the Asia-Pacific iron ore market has been dramatically restructured during the last decade. This process has been accelerated since 2005 by Chinese governmental resource security policies, which have sought to address current record high iron ore prices through the use of foreign investment to sponsor new market entrants and the formation of an import cartel amongst the Chinese steel firms. This paper evaluates how these policies have driven restructuring in the Asia-Pacific iron ore market, through an analysis of the growth of China's steel industry, Chinese resource security policies aimed at lowering iron ore import costs, and their effects upon the regional market's ownership structure and price determination mechanisms. It argues that while Chinese investment and cartelisation policies have catalysed significant changes to the ownership and pricing structures of the Asia-Pacific iron ore market, they have carried only mixed benefits for the Chinese steel industry's resource security.     

Mineral reserves under price uncertainty

National reporting organizations and regulatory bodies for the minerals and mining sector are requiring publicly reported Ore-Reserve estimates to take account of uncertainties. Whilst methodologies that account for physical uncertainty appear relatively well developed, methodologies which can take account of economic uncertainty appear much less so. To counter this shortfall, we present an efficient and general methodology which can quantify the effect of price uncertainty within reserve estimates, providing both the expected reserve size and the associated distribution (box whisker plot). This statistical information can be used by interested parties to understand precisely where the reserve risks lie, which we highlight in a worked example.     

Perspectives on community representation within the Extractive Industries Transparency Initiative: Experiences from south-east Madagascar

This article critically examines the nature and quality of governance in community representation and civil society engagement in the context of trans-national large-scale mining, drawing on experiences in the Anosy Region of south-east Madagascar. An exploration of functional relationships between government, mining business and civil society stakeholders reveals an equivocal legitimacy of certain civil society representatives, created by state manipulation, which contributes to community disempowerment. The appointment of local government officials, rather than election, creates a hierarchy of upward dependencies and a culture where the majority of officials express similar views and political alliances. As a consequence, community resistance is suppressed.     

Social responsibility and resource extraction: Are Chinese oil companies different?

In order to meet China’s rapidly increasing demand for oil, Chinese oil companies have been investing in oil production around the world. This article addresses one specific aspect of the more generalized fears expressed about China’s increasing demand for natural resources which is the impact that its oil companies will have on the corporate social responsibility (CSR) movement. In doing so, it limits its analysis to the three main Chinese oil companies: the China National Petroleum Corporation (CNPC), the China Petroleum and Chemical Corporation (Sinopec) and the China National Offshore Oil Corporation (CNOOC) and their investments in sub-Saharan Africa.     

Corporate Social Responsibility and development in Africa: Redefining the roles and responsibilities of public and private actors in the mining sector

This paper revisits the role of Corporate Social Responsibility (CSR), suggesting the usefulness of adopting a holistic and historical perspective. It underlines the importance of taking into account the evolving regulatory frameworks within which mining activities take place in order to consider the changing roles played by the various actors involved, whether multilateral, national or local, public or private. In this broad context it then becomes possible to revisit issues of legitimacy, responsibility, and accountability, which CSR strategies aim to address. The article draws attention to the shortcomings of strategies, whether bilateral or multilateral, public or private, which, in an attempt to respond to problems of risk and legitimacy faced by mining companies, have put forward measures in the name of CSR that do not address the origins that give rise to such problems and, in so doing, tend to mask the very nature of the difficulties at hand. The analysis leads to quite different conclusions as compared to those that result from the adoption of a shorter term and investment-led perspective.