Debris removal during disaster response: A case for Turkey

Debris occurs from the ruin and wreckage of structures during a disaster. Proper removal of debris is of great importance because it blocks roads and prohibits emergency aid teams from accessing disaster-affected regions. Poor disaster management, lack of efficiency and delays in debris removal cause disruptions in providing shelter, nutrition, healthcare and communication services to disaster victims, and more importantly, result in loss of lives. Due to the importance of systematic and efficient debris removal from the perspectives of improving disaster victims quality of life and allowing the transportation of emergency relief materials, the focus of this study is on providing emergency relief supplies to disaster-affected regions as soon as possible by unblocking roads through removing the accumulated debris. We develop a mathematical model for the problem that requires long CPU times for large instances. Since it is crucial to act quickly in an emergency case, we also propose a heuristic methodology that solves instances with an average gap of 1% and optimum ratio of 80.83%.     

The volunteer matrix: positioning of volunteer organizations

• In the fierce competition that volunteer involving organizations face nowadays over people's willingness to donate their time, marketing strategies should be used. In order to enhance the organization's recruitability (ability to recruit suitable volunteers), it is important for volunteer organizations to understand what the positioning of the organization is and the type of volunteering that is being offered. In the current article we suggest using a marketing tool to increase the ability to recruit volunteers: positioning and perceptual mapping. Our perceptual mapping – the volunteer matrix is based on two dimensions: price (different costs attached to the volunteer experience) and quality (the overall quality of the volunteering experience). Thus, the matrix includes four different positions, and we demonstrate the manners in which different volunteer organizations or roles are positioned in each. Discussed are also the possible implementations of the matrix in order to recruit suitable volunteers and retain them.

Copyright © 2010 John Wiley & Sons, Ltd.     

An optimization model for volunteer assignments in humanitarian organizations

One of the challenges facing humanitarian organizations is that there exist limited decision technologies that are tailored specifically to their needs. While employee workforce management models have been the topic of extensive research over the past decades, very little work has yet concentrated on the problem of managing volunteers for humanitarian organizations. This paper develops a multi-criteria optimization model to assist in the assignment of volunteers to tasks, based upon a series of principles from the field of volunteer management. In particular, it offers a new volunteer management approach for incorporating the decision maker's preferences and knowledge into the volunteer assignment process, thus allowing him or her to closely examine the tradeoffs between potentially conflicting objectives. Test results illustrate the model's ability to capture these tradeoffs and represent the imprecision inherent in the work of humanitarian organizations, and thus demonstrate its ability to support efficient and effective volunteer management.     

基于免疫—蚁群算法的应急物流配送网络优化研究

论文针对应急物流的配送车辆路径优化问题,建立以应急物流初期有限资源的分配达到整体的最优化（时间短、效率高、安全高、成本低）的多目标模型,结合模型的特点,利用免疫算法和蚁群算法相融合的启发式算法进行求解,最后进行算例分析,解决应急物流配送车辆路径选择的实际问题。     

Practical POMDP-based test mechanism for quality assurance in volunteer crowdsourcing

ABSTRACT

In volunteer crowdsourcing, tasks are published via an open call and completed by many workers without reward. Under the traditional volunteer crowdsourcing paradigm, workers with diverse levels of reliabilities are chosen indiscriminately; moreover, each worker’s performance may change over the time. Thus, the quality of task completions is a key concern in volunteer crowdsourcing. To improve the task completion quality (i.e. the accuracy of task answers), we adopt an adaptive test task (with a true answer) insertion approach to detect a worker’s performance dynamically, thereby ensuring that normal tasks (with unknown true answers) are assigned when this worker is currently deemed reliable via testing. To decide when to route test tasks to detect a worker’s performance or assign normal tasks to be completed in a high quality state, we proposed a Partially Observable Markov Decision Processes (POMDP) based test mechanism without any complicated parameter estimation, which is more practical for real-world volunteer crowdsourcing applications. In addition, we also designed rejection strategies to reject malicious workers and dubious answers. Experiments on real datasets demonstrate that the proposed test mechanism performs better in the accuracy of task answers, compared with benchmark methods.     

Customizing immunization clinic operations to minimize open vial waste

Many multi-dose vaccine vials must be used within hours of reconstitution; unused doses are discarded as “open vial waste.” Building on Mofrad et al. (2014), we evaluate operating strategies that maximize coverage by controlling open vial waste. We define novel metrics for determining thresholds on vaccination clinic operating hours and session frequency. We study the performance of optimal and heuristic policies in the presence of random vial yield. Cost analyses indicate significant potential savings. Because optimal strategies are context specific, we also develop a decision support tool (available online) to easily replicate the analysis for any problem setting.     

Understanding individual responses to failure by the organisation to fulfil its obligations: examining the influence of psychological capital and psychological contract type

This study advances both psychological contract (PC) and psychological capital (PsyCap) research by testing a novel theoretical model predicting likely worker response, as a joint function of an individual's level of PsyCap and PC type, to perceived failure by the organisation to meet its obligations to the worker–organisation relationship. With a large emergency services organisation using volunteer workers as the research context, the study presents the first empirical evidence from a sample of 592 volunteers that the integrated application of PC and PsyCap theory can contribute to a better understanding of individual responses to an organisation's failure to affirm ongoing support for the volunteer–organisation relationship.     

Scheduling spatially distributed jobs with degradation: Application to pothole repair

This paper considers scheduling spatially distributed jobs with degradation. A mixed integer programming (MIP) model is developed for the linear degradation case in which no new jobs arrive. Properties of the model are analyzed, following which three heuristics are developed, enhanced greedy, chronological decomposition and simulated annealing. Numerical tests are conducted to: (i) establish limits of the exact MIP solution, (ii) identify the best heuristic based on an analysis of performance on small problem instances for which exact solutions are known, (iii) solve large problem instances and obtain lower bounds to establish solution quality, and (iv) study the effect of three key model parameters. Findings from our computational experiments indicate that: (i) exact solutions are limited to instances with less than 14 jobs; (ii) the enhanced greedy heuristic followed by the application of the simulated annealing heuristic yields high quality solutions for large problem instances in reasonable computation time; and (iii) the factors “degradation rate” and “work hours” have a significant effect on the objective function. To demonstrate applicability of the model, a case study is presented based on a pothole repair scenario from Buffalo, New York, USA. Findings from the case study indicate that scheduling spatially dispersed jobs with degradation such as potholes requires: (i) careful consideration of the number of servers assigned, degradation rate and depot location; (ii) appropriate modeling of continuously arriving jobs; and (iii) appropriate incorporation of equity consideration.     

Unlikely allies: Bureaucracy as a cultural trope in a grassroots volunteer organization

This article investigates the role of bureaucratic organizing in a grassroots volunteer organization, which emerged during the so-called refugee crisis in an emergency refugee shelter in Germany. Most research agrees that this type of organization is by definition counter-bureaucratic. In the organization I studied, however, volunteers adopted, accepted and acclaimed bureaucratic organizing as the only, natural and self-evident way of making the grassroots work. Drawing on ethnographic research, my analysis unravels how bureaucracy became a common frame of reference that allowed the volunteers to self-organize despite their different motivations, attitudes and social backgrounds. To theorize these findings, the paper draws on the concept of a cultural trope. In so doing, it offers a more nuanced understanding of bureaucracy in grassroots volunteer organizations that might stimulate scholars to rethink its role in other fluid, dynamic and value-driven organizations.     

VMI模式下的非周期性IRP问题

本文针对VMI管理模式下非周期性计划期、单车辆IRP问题，建立供应商库存管理路径优化模型．利用两阶段启发式算法结合蚁群算法、遗传算法等亚启发式算法来求解模型，并分析结果影响。     

Coping and adjustment of Western expatriate managers in Hong Kong

This article examines coping mechanisms of Western expatriate business managers in Hong Kong to determine how these strategies are associated with the expatriates’ sociocultural and psychological adjustment. This is important since the few previous studies that have touched upon expatriate coping strategies have focused on other topics which affected both their samples, methodology and findings. Furthermore, effective coping strategies can be taught in cultural training programs better preparing expatriate candidates for their foreign assignments. As predicted, the results indicated a clear positive association between problem focused coping and both sociocultural and psychological adjustment as well as a negative relation between symptom focused coping and both dimensions of adjustment. Implications for international business firms and future research of the findings are discussed in detail.     

Converting volunteers to donors: Fundraising strategies for professional associations

The use of fundraising strategies in professional associations is on the rise as member donations have become an increasingly important revenue stream for the associations. This study aims to understand why member volunteers are potential donors to professional associations and to examine whether association solicitation is effective in increasing member volunteer donations. A moderated mediation model was tested with data that consisted of 3,224 professional association members. The results suggest that member satisfaction significantly mediates the relationship between member volunteering and financial giving, and solicitation only makes a difference to member volunteers who are satisfied with their membership. This study concludes that targeting satisfied member volunteers for donations could yield financial benefits to professional associations.     

Dispatching and routing of emergency vehicles in disaster mitigation using data fusion

The aim of this paper is to develop a robust methodology for the dispatching and routing of emergency vehicles (EVs) in a post-disaster environment with the support of data fusion. In this work, we consider an earthquake scenario with a large number of casualties needing medical attention. Given an influx of information (regarding casualties, road, traffic conditions, etc.), data are fused to provide estimates of the entities under consideration. We use this information to dispatch and route EVs to casualty pickup locations, followed by delivery to appropriate hospitals. Key factors here include patient priorities, clustering criteria, and distance. Similarly, factors affecting the dispatching of EVs from patient locations to hospitals include waiting time at hospital emergency rooms, hospital capacity, and distance. Routes must be generated for EVs by accounting for real-world road networks, existing road damage, congestion, and related issues. We develop a dispatching and routing simulation model, and utilize a case study to evaluate the performance of our proposed methodology.     

一次性消耗的应急系统资源调度问题研究

文章研究了一次性消耗的应急资源调度问题,将参与应急的出救点数目最少和应急开始时间最短同时作为优化目标,首先给出了参与应急出救点数目取值范围的判定定理,然后将问题转化为出救点数一定条件下的应急开始时间最早的单目标优化问题,从而得到一组Pareto最优解。并从理论上证明了求解方法的有效性和正确性。     

考虑人口因素的公共应急服务设施选址问题研究

研究了考虑人口因素的公共应急服务设施选址问题,建立了该问题数学模型,分别设计了求解该问题的精确算法和启发式算法,并通过具体的案例进行了求解及分析,得到了满意的结果。     

Facility location under demand uncertainty: Response to a large-scale bio-terror attack

In the event of a catastrophic bio-terror attack, major urban centers need to efficiently distribute large amounts of medicine to the population. In this paper, we consider a facility location problem to determine the points in a large city where medicine should be handed out to the population. We consider locating capacitated facilities in order to maximize coverage, taking into account a distance-dependent coverage function and demand uncertainty. We formulate a special case of the maximal covering location problem (MCLP) with a loss function, to account for the distance-sensitive demand, and chance-constraints to address the demand uncertainty. This model decides the locations to open, and the supplies and demand assigned to each location. We solve this problem with a locate-allocate heuristic. We illustrate the use of the model by solving a case study of locating facilities to address a large-scale emergency of a hypothetical anthrax attack in Los Angeles County.     

The maximal covering location problem with accessibility indicators and mobile units

We study the Maximal Covering Location Problem with Accessibility Indicators and Mobile Units that maximizes the facilities coverage, the accessibility of the zones to the open facilities, and the spatial disaggregation. The main characteristic of our problem is that mobile units can be deployed from open facilities to extend the coverage, accessibility, and opportunities for the inhabitants of the different demand zones. We formulate the Maximal Covering Location Problem with Accessibility Indicators and Mobile Units as a mixed-integer linear programming model. To solve larger instances, we propose a matheuristic (combination of exact and heuristic methods) composed of an Estimation of Distribution Algorithm and a parameterized Maximal Covering Location Problem with Accessibility Indicators and Mobile Units integer model. To test our methodology, we consider the Maximal Covering Location Problem with Accessibility Indicators and Mobile Units model to cover the low-income zones with Severe Acute Respiratory Syndrome Coronavirus 2 patients. Using official databases, we made a set of instances where we considered the poverty index, number of population, locations of hospitals, and Severe Acute Respiratory Syndrome Coronavirus 2 patients. The experimental results show the efficiency of our methodologies. Compared to the case without mobile units, we drastically improve the coverage and accessibility for the inhabitants of the demand zones.     

A Fraternity Of Danger

A bstract . Interviews and participation with members of rural volunteer fire departments (VFDs) in New York State, indicate that local communities in rural regions are structured around VFDs. Such "communities" involves both the fraternity of the fire house, resting on the teamwork essential to firefighting, and a wider locality, which the VFDs spatially define and symbolically integrate through a ritual of parades, fund raising efforts, and their example of community service. The working class, attached to the locality by stable residence and recruited intergenerationally into the fire service, supplies the majority of volunteers.
Neoliberal modernization threatens this recruitment pattern. Problems have developed because the "new middle class" rejects VFD participation, except as ambulance volunteers. As localities compete for outside investment through the reduced cost of their services, they have exploited volunteers to provide fire protection at less cost than that of paid departments. This commodification of the VFDs risks destroying their character as a system of moral obligation unifying a locality and is an inequitable, and unsustainable, "tax" on working class volunteers. But innovative systems of emergency and other services can be used to attract the new male and female middle class into volunteer local activities.     

Mathematical programming for nominating exchange students for international universities: The impact of stakeholders’ objectives and fairness constraints on allocations

We consider the problem of nominating exchange students to attend international universities where places are limited. We take into account three objectives: The sending university aims to maximize the number of nominations, the students seek nomination for a highly preferred university and, finally, the receiving universities strive for excellent incoming students. Pairwise comparison of students should guarantee the following fairness: A student with higher academic achievements should be preferred over a student with lower academic achievements. We provide mathematical programming models of the nomination problem which maximize the overall objectives and guarantee different types of pairwise fairness. Several years of real data from a major school are employed to evaluate the models’ performance including a benchmark against the heuristic that is used by the school. We show analytically and experimentally that the heuristic approach fails to guarantee some pairwise fairness. Our results reveal the following four insights: First, compared to the current approach, up to 6.6% more students can be nominated with our optimization model while ensuring all pairwise fairness perspectives. Second, on average, students are nominated with better academic achievements. Third, the problem instances can be solved to optimality within a fraction of a second even for large-size instances comprising more than 500 students and about 150 schools offering nearly 450 exchange places. This is important for its use in practice. Last, up to 17.9% more students can be nominated when considering the overall objective to maximize nominations.     

A process model of volunteer motivation

Traditional HR functions of recruitment, selection, training/development, and retention must be adapted when managing a volunteer workforce. While much research has focused on what motivates people to volunteer, very little has focused on the process of volunteer motivation. In this paper, we move beyond the traditional content-based approaches to explain how people decide whether to volunteer, how much effort to expend, and then whether to continue volunteering over time. Our model, based on image theory, provides new insights into volunteer decision making and behavior.