New Modeling and Solution Paradigms for Transportation Problems with Applications to Railroads

为了提供服务，行业和政府在很大程度上依赖于他们高效运输货物的能力。在最简单的形式下，运输问题可以使用传统的优化算法有效地解决。然而，实际应用经常表现出各种额外的组合要求，这就需要涉及建模，通常是以整数规划的形式。这种建模通常被从业者视为不自然，并导致使用最先进的商业软件难以解决的模型。该奖项的研究目标是为此类交通问题开发一种新的建模和解决方案。在这个范例中，确定了几个关键结构，允许用户简洁地施加经常出现的组合约束，而不需要使用整数规划来表示它们。然后可以利用这些构造来设计更高效、准确和启发式的求解方法，这些方法利用网络的结构和组合要求。这项研究还将试图证明这一范例在解决铁路散装运输所产生的实际问题上的优势。如果成功，这项研究将产生一个集成的建模和解决方案范例，为更大的交通问题提供更快的解决方案，并将许多目前难以解决的实际相关问题纳入可处理范围。它将导致减少运输成本和里程的解决方案，从而提高依赖运输的行业的效率。结果将通过会议、出版物和一个专门的互联网网页及时传播，该网页将包含相关模型、风格化应用和原型实施。本科生和研究生也将通过开发课程材料和参与研究而受益于这一奖项。

To provide services, industries and the government rely heavily on their ability to efficiently transport goods. In their simplest form, transportation problems can be solved efficiently using traditional optimization algorithms. However, practical applications often exhibit a variety of additional combinatorial requirements that necessitate involved modeling, often in the form of integer programs. This modeling is often seen as unnatural by practitioners and results in models that are difficult to solve with state-of-the-art commercial software. The research objective of this award is to develop a new modeling and solution paradigm for such transportation problems. In this paradigm, a few key constructs are identified that allow the user to succinctly impose often-occurring combinatorial constraints without the need to formulate them using integer programming. These constructs can then be exploited to design more efficient exact and heuristic solution methodologies that take advantage of the structure of the network and of the combinatorial requirements. The research will also seek to demonstrate the advantages of this paradigm on practical problems emanating from bulk delivery in railroads. If successful, this research will result in an integrated modeling and solution paradigm that will provide faster solutions to larger transportation problems and that will bring within the range of tractability many practically relevant problems that are currently intractable. It will lead to solutions where transportation costs and miles are reduced and will therefore improve the efficiency of industries relying on transportation. Results will be disseminated timely via conferences, publications and a dedicated internet page that will contain relevant models, stylized applications and prototype implementations. Undergraduate and graduate students will also benefit from this award through the development of course material and involvement in research.