适应高速铁路自动驾驶系统的列车运行计划调整策略研究

高速铁路列车自动驾驶(ATO)系统是铁路智能化发展的重要组成部分,其应用实现了列车运行多项功能的联动控制,显著提升了高速铁路自动化水平,减轻了工作人员的劳动强度。我国铁路网密度大、运用场景复杂,列车运行计划实时调整难度较大,对ATO系统运用有更高的要求。基于ATO系统工作原理,分析ATO系统与运行计划的关联关系,总结列车运行计划与ATO系统适应性存在的不足,提出了适应ATO系统的列车运行计划调整策略,可以为优化ATO列车运行计划调整策略、提升高速铁路服务水平与效能提供支撑。     

Viewpoint: COVID-19 and seed security response now and beyond

COVID-19 brings new challenges worldwide, including to smallholder farmers and their seed systems. In response, an escalating number of seed projects are being planned to deliver immediate aid or to alter current seed production programs. A Statement, prepared by diverse seed system experts, aims to steer both the immediate aid (next 1–2 seasons) and more developmental planning (next 1–3 years). The Statement includes 10 short-term and 4 medium-term recommendations, placing emphasis on all seed systems smallholders use: formal, informal, and integrated. It also looks beyond seed per se to the direct information and digital systems that shape remote assessments, data sharing and inclusive feedback. The Statement is prefaced by an introduction that helps contextualize the recommendations, reviews the history of humanitarian seed aid and summarizes the varied response forms that have unfolded over the last three decades.     

Efficiency analysis of emergency departments in metropolitan areas

The demand in the healthcare industry is increasing exponentially due to aging population of the world and this is leading to a rapid increase in the cost of healthcare. The emergency departments of the hospitals are the frontline of health care systems and play an additional critical role in providing an efficient and high-quality response for patients. The overcrowding at the emergency departments due to growing demand results in a situation where the demand for ED services exceeds the ability to provide care in a reasonable amount of time. This has led countries to reconsider their health policies in a way to increase their efficiency in their healthcare systems in general and in emergency departments, in particular. As in many countries, there has been a steady and significant increase in the number of patients that seek health services at the emergency departments of state hospitals of Turkey, due to the significant structural reforms in health services since 2003. While meeting this increasing demand, it is ever more important to provide these critical health services efficiently. Therefore, the efficiency of the emergency departments of seven general hospitals run by Istanbul's Beyoglu State Hospitals Association have been analyzed using categorical Data Envelopment Analysis (DEA) models. The analysis of DEA results is supported by a set of statistical methods to make it easier for the hospital administrators to interpret the analysis and draw conclusions. The analysis shows that less-equipped EDs are supported by better equipped, larger EDs, resulting in a hub-and-spoke type of structure among the EDs where “satellite” EDs serve an important referral function and thus evaluating their efficiency without taking the interoperability among these units into account would not be an accurate assessment of their performance.     

Analysis of different public policies through simulation to increase total social utility in a healthcare system

Public and private hospitals are seen to co-exist in several countries and they have different levels of service, waiting times and prices. Public hospitals, in general, are cheaper, but more crowded and offer lower quality service than private ones while private ones are underutilized because of the higher payments required for their services. These differences among hospitals affect patients’ choices in hospital selection and result in different levels of satisfaction in the community. Appropriate subsidy mechanisms can be developed to balance the capacity utilization of both sectors and to improve overall access to healthcare. The objective of this study is to develop an estimate of the magnitude of this improvement and differential effectiveness of various policies in achieving this improvement. For this purpose, we develop a simulation model that includes all the emergency departments of main public and private hospitals in a certain region of Turkey. We analyze the effects of different public policies on patients’ preferences regarding hospital choices and the results of these choices on social utility and public healthcare spending. Different capacity decisions, contracting and subsidy mechanisms are proposed and the optimal system parameters are determined under these mechanisms over this simulation model. After the validation and verification of the simulation model, several scenarios are designed and executed to increase social utility, decrease government expenses, improve patient satisfaction level and decrease waiting times. We compare the proposed scenarios based on multiple objective functions and present numerical results for different scenarios in this system.     

Collective efficacy and natural hazards: differing roles of social cohesion and task-specific efficacy in shaping risk and coping beliefs

Abstract

Previous research in non-disaster contexts has shown that the concept of collective efficacy, which is a group’s sense of its ability to achieve a specific objective, assists understanding of community readiness and households’ decisions to take preparedness actions. Collective efficacy expands the concept of social capital, which refers to social resources such as trust, norms and networks, by addressing how likely communities are to activate these resources for specific tasks. This paper empirically investigates the effect of three distinct collective efficacy components on risk perception, fear and self-efficacy regarding natural hazards in Austria. The three components have differing impacts on risk and coping beliefs: (1) Social cohesion decreases risk perception and fear but has no effect on self-efficacy; (2) Efficacy belief in social support increases self-efficacy; (3) Efficacy belief in citizen groups increases risk perception and fear. The combination of efficacy belief in social support and citizen groups seems to be most promising for stimulating protective action, as they together promote both risk and coping appraisal. However, overreliance on social support may have the undesirable effect of creating a false sense of safety among disaster-prone households. The findings demonstrate that collective efficacy provides a meaningful perspective from which to examine risk and coping beliefs but caution against treating it as an umbrella concept, given the differing effects of its components. Future studies are needed to investigate the impact of collective efficacy on other key explanatory factors of protective action, such as response efficacy or non-protective responses.     

瑞昌市政府应急机制分析

各级党委政府特别是县级政府应把建立突发事件应急机制纳入城市可持续发展的总体战略规划之中,与经济建设和各项社会事业协调发展。本文主要分析江西省瑞昌市政府在应对自然灾害时应急机制的缺失与不足。     

A fuzzy multi-objective programming approach for determination of resilient supply portfolio under supply failure risks

The main contribution of this paper is to develop a new decision tool that interprets strategies for determination of resilient supply portfolio under supply failure risks. The strategic decisions include the allocation of emergency capacities to be pre-positioned at backup suppliers, the output of which can be increased in the event of mitigating a shortage caused by another supplier's failure. The model contains three objective functions – minimising the total cost, minimising the net rejected items and minimising the net late deliveries – while satisfying capacity and minimum order quantity requirement constraints. A weighted additive fuzzy multi-objective model is proposed to simultaneously consider the imprecision of information and the relative importance of objectives for determining the allocation of order quantity and emergency capacity to each supplier. The application of the proposed model is illustrated using an example case of global supply chains with different supplier characteristics.     

Real-time relief distribution in the aftermath of disasters – A rolling horizon approach

This paper presents a rolling horizon-based framework for real-time relief distribution in the aftermath of disasters. This framework consists of two modules. One is a state estimation and prediction module, which predicts relief demands and delivery times. The other is a relief distribution module, which solves for optimal relief distribution flows. The goal is to minimize the total time to deliver relief goods to satisfy the demand, considering uncertain data and of the risk-averse attitude of the decision-maker. A numerical example based on the large-scale earthquake that occurred on September 21, 1999 in Taiwan is presented to demonstrate the system.     

A stochastic programming approach for floods emergency logistics

This article presents a model to assist decision makers in the logistics of a flood emergency. The model attempts to optimize inventory levels for emergency supplies as well as vehicles’ availability, in order to deliver enough supplies to satisfy demands with a given probability. A spatio-temporal stochastic process represents the flood occurrence. The model is approximately solved with sample average approximation. The article presents a method to quantify the impact of the various intervening logistics parameters. An example is provided and a sensitivity analysis is performed. The studied example shows large differences between the impacts of logistics parameters such as number of products, number of periods, inventory capacity and degree of demand fulfillment on the logistics cost and time. This methodology emerges as a valuable tool to help decision makers to allocate resources both before and after a flood occurs, with the aim of minimizing the undesirable effects of such events.     

Should executives go to jail over cybersecurity breaches?

The Consumer Data Protection Act, a new bill introduced by Senator Ron Wyden, is proposing “jail time of up to 20 years for executives who knowingly sign off on incorrect or inaccurate annual certifications of their companies’ data-security practices.” The bill also recommends that companies be fined “up to 4 percent of their annual revenue.” While the critics consider the penalties too harsh and severe, the proposed legislation reflects two key realities – a) active involvement and commitment of senior management is essential to achieving a high level of cybersecurity preparedness; and b) legislation and fear of severe penalties (such as Sarbanes-Oxley Act of 2002 and European Union’s General Data Protection Regulation) is often necessary to motivate desired organizational behavior. In an increasingly digital ecosystem characterized by high levels of electronic connectivity, vulnerability to cyberattacks is growing. Organizations are in a perpetual state of breach with rapidly expanding attack surfaces and evolving threat vectors. Protecting confidential data and related digital assets is becoming critical to survival and success. Senior management must come to terms with this new business reality and give strategic priority to cybersecurity preparedness and investments. Research finds active involvement of top management in cyber risk mitigation initiatives to be a critical success factor and best practice. The onus is also on senior management to create a high-performance security culture founded on three key cornerstones – commitment, preparedness, and discipline. They also must lead the charge in establishing a cybersecurity governance structure characterized by joint ownership, responsibility, and accountability.