1,065 research outputs found
A Two-Tier Urban Delivery Network with Robot-based Deliveries
In this paper, we investigate a two-tier delivery network with robots operating on the second tier. We determine the optimal number of local robot hubs as well as the optimal number of robots to service all customers and compare the resulting operational cost to conventional truck-based deliveries. Based on the well-known p-median problem, we present mixed-integer programs that consider the limited range of robots due to battery size. Compared to conventional truck-based deliveries, robot-based deliveries can save about 70% of operational cost and even more, up to 90%, for a scenario with customer time windows
Flexible Time Window Management for Attended Home Deliveries
In the competitive world of online retail, customers can choose from a selection of delivery time windows on a retailer's website. Creating a set of suitable and cost-efficient delivery time windows is challenging, since customers want short time windows, but short time windows can increase delivery costs significantly. Furthermore, the acceptance of a request in a particular short time window can greatly restrict the ability to accommodate future requests. In this paper, we present customer acceptance mechanisms that enable flexible time window management in the booking of time-window based attended home deliveries. We build tentative delivery routes and check which time windows are feasible for each new customer request. We offer the feasible long delivery time windows as a standard and let our approaches decide when to offer short time windows. Our approaches differ in the comprehensiveness of information they consider with regard to customer characteristics as well as detailed characteristics of the evolving route plan. We perform a computational study to investigate the approaches' ability to offer short time windows and still allow for a large number of customers to be served. We consider various demand scenarios, partially derived from real order data from a German online supermarket
The Flood Mitigation Problem in a Road Network
Natural disasters are highly complex and unpredictable. However, long-term
planning and preparedness activities can help to mitigate the consequences and
reduce the damage. For example, in cities with a high risk of flooding,
appropriate roadway mitigation can help reduce the impact of floods or high
waters on transportation systems. Such communities could benefit from a
comprehensive assessment of mitigation on road networks and identification of
the best subset of roads to mitigate. In this study, we address a pre-disaster
planning problem that seeks to strengthen a road network against flooding. We
develop a network design problem that maximizes the improvement in
accessibility and travel times between population centers and healthcare
facilities subject to a given budget. We provide techniques for reducing the
problem size to help make the problem tractable. We use cities in the state of
Iowa in our computational experiments.Comment: 40 pages, 8 figures, 21 table
Modeling Correlation in Vehicle Routing Problems with Makespan Objectives and Stochastic Travel Times
The majority of stochastic vehicle routing models consider travel times to be independent. However, in reality, travel times are often stochastic and correlated, such as in urban areas. We examine a vehicle routing problem with a makespan objective incorporating both stochastic and correlated travel times. We develop an approach based on extreme-value theory to estimate the expected makespan (and standard deviation) and embed this within a routing heuristic. We present results that demonstrate the impact of different correlation patterns and levels of correlation on route planning
Time Slot Management in Attended Home Delivery
Many e-tailers providing attended home delivery, especially e-grocers, offer narrow delivery time slots to ensure satisfactory customer service. The choice of delivery time slots has to balance marketing and operational considerations, which results in a complex planning problem. We study the problem of selecting the set of time slots to offer in each of the zip codes in a service region. The selection needs to facilitate cost-effective delivery routes, but also needs to ensure an acceptable level of service to the customer. We present two fully-automated approaches that are capable of producing high-quality delivery time slot offerings in a reasonable amount of time. Computational experiments reveal the value of these approaches and the impact of the environment on the underlying trade-offs
Demand Management Opportunities in E-fulfillment: What Internet Retailers Can Learn from Revenue Management
In this paper, we explain how Internet retailers can learn from proven revenue management concepts and use them to reduce costs and enhance service. We focus on attended deliveries as these provide the greatest opportunities and challenges. The key driver is service differentiation. Revenue management has shown that companies can do much better than a one-size-fits-all first-come-first-serve strategy when selling scarce capacity to a heterogeneous market. Internet retailers have strong levers at their disposal for actively steering demand, notably the offered delivery time windows and their associated prices. Unlike traditional revenue management, these demand management decisions affect both revenues and costs. This calls for a closer coordination of marketing and operations than current common practice
Are we there yet? Laboratory preparedness for emerging infectious diseases
The West African Ebola virus epidemic of 2013–2016
was the most widespread epidemic of this disease in history;
it is estimated that this occurrence contributed to
more than 11000 deaths. During the epidemic, healthcare
workers (HCW)8 (including laboratorians) were
mobilized to care for individuals with suspected or confirmed
Ebola virus disease (EVD). However, at the
height of the epidemic, guidance on appropriate safety
measures for laboratory workers manipulating specimens
from EVD patients was sparse. This highlighted the need
for data and guidelines for laboratories testing specimens
not only for patients with EVD, but for any emerging
infectious disease. During the Ebola epidemic, questions
were raised about the roles and responsibilities of laboratories
in responding to highly infectious diseases, and the burden
of ongoing readiness for rare events. As the outbreak
decelerates, laboratorians must regroup, gather data, and
prepare for future outbreaks. We have asked 4 experts in this
field to share their thoughts on contemporary challenges in
laboratory preparedness for emerging infectious disease
2006 AAPP Monograph American Series
The African American Professors Program (AAPP) at the University of South Carolina is proud to publish the sixth edition of its annual monograph series. The program recognizes the significance of offering its scholars a venue for engaging actively in research and for publishing papers related thereto. Parallel with the publication of their refereed manuscripts is the opportunity to gain visibility among scholars throughout institutions worldwide.
Scholars who have contributed manuscripts for this monograph are to be commended for adding this additional responsibility to their academic workloads. Writing across disciplines adds to the intellectual diversity of these papers. From neophytes, relatively speaking, to an array of very experienced individuals, the chapters have been researched and comprehensively written.
Founded in 1997 through the Department of Educational Leadership and Policies in the College of Education, AAPP was designed to address the underrepresentation of African American professors on college and university campuses. Its mission is to expand the pool of these professors in critical academic and research areas. Sponsored by the University of South Carolina, the W.K. Kellogg Foundation, and the South Carolina General Assembly, the program recruits doctoral students for disciplines in which African Americans currently are underrepresented among faculty in higher education.
The continuation of this monograph series is seen as responding to a window of opportunity to be sensitive to an academic expectation of graduates as they pursue career placement and, at the same time, one that allows for the dissemination of AAPP products to a broader community. The importance of this monograph series has been voiced by one of our 2002 AAPP graduates, Dr. Shundele LaTjuan Dogan, a former Program Officer for the Southern Education Foundation, Atlanta, Georgia, a former Administrative Fellow at Harvard University, and currently a Senior Program Officer with the Arthur M. Blank Foundation, focusing on the Pathways to Success Initiative. Dr. Dogan wrote:
One thing in particular that I want to thank you for is having the African American Professors Program scholars publish articles for the monograph. I have to admit that writing the articles seemed like extra work at the time. However, in my recent interview process, organizations have asked me for samples of my writing. Including an article from a published monograph helped to make my portfolio much more impressive. You were \u27right on target\u27 in having us do the monograph series. {AAPP 2003 Monograph, p xi)
The African American Professors Program offers this 2006 publication as a contribution to its readership and hopes that you will be inspired by this select group of manuscripts.
John McFadden, Ph.D.
The Benjamin Elijah Mays Professor
Director, African American Professors Program
University of South Carolinahttps://scholarcommons.sc.edu/mcfadden_monographs/1008/thumbnail.jp
Work Placement for International Student Programs (WISP): a model of effective practice
With a marked increase in the number of international students enrolling in university programs across the globe it is important that personal and professional experiences are positive. Of interest is the workplace component of international students’ study programs, as these experiences provide opportunities for students to socialise into new workplaces and cultural contexts. This chapter presents a theoretical model that takes into account the relationship between the concepts of internationalisation, professional socialisation, reflection and cultural development. It explores Knight’s (1999) work on internationalisation; research on personal and professional socialisation; effective reflective practice; and the notion of cultural development (Wells, 2000). We argue that an enhanced ethos approach, together with strong personal and professional student and staff agency and reflective practice, enhances the work placement experience. If all these elements are taken into account and the interrelationship between them is understood, we contend that it is more likely for workplace experiences to be positive and meaningful for all stakeholders
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