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A Graph Theoretic Additive Approximation of Optimal Transport

Nathaniel Lahn, Deepika Mulchandani, Sharath Raghvendra

Neural Information Processing Systems

Transportation cost is an attractive similarity measure between probability distributions due to its many useful theoretical properties. However, solving optimal transport exactly can be prohibitively expensive.


A Novel Machine Learning Approach to Data Inconsistency with respect to a Fuzzy Relation

Palangetić, Marko, Cornelis, Chris, Greco, Salvatore, Słowiński, Roman

arXiv.org Artificial Intelligence

Inconsistency in prediction problems occurs when instances that relate in a certain way on condition attributes, do not follow the same relation on the decision attribute. For example, in ordinal classification with monotonicity constraints, it occurs when an instance dominating another instance on condition attributes has been assigned to a worse decision class. It typically appears as a result of perturbation in data caused by incomplete knowledge (missing attributes) or by random effects that occur during data generation (instability in the assessment of decision attribute values). Inconsistencies with respect to a crisp preorder relation (expressing either dominance or indiscernibility between instances) can be handled using symbolic approaches like rough set theory and by using statistical/machine learning approaches that involve optimization methods. Fuzzy rough sets can also be seen as a symbolic approach to inconsistency handling with respect to a fuzzy relation. In this article, we introduce a new machine learning method for inconsistency handling with respect to a fuzzy preorder relation. The novel approach is motivated by the existing machine learning approach used for crisp relations. We provide statistical foundations for it and develop optimization procedures that can be used to eliminate inconsistencies. The article also proves important properties and contains didactic examples of those procedures.


Backpropagation and fuzzy algorithm Modelling to Resolve Blood Supply Chain Issues in the Covid-19 Pandemic

Erlansari, Aan, Effendi, Rusdi, C, Funny Farady, Wijanarko, Andang, Susilo, Boko, Hardiansyah, Reza

arXiv.org Artificial Intelligence

Bloodstock shortages and its uncertain demand has become a major problem for all countries worldwide. Therefore, this study aims to provide solution to the issues of blood distribution during the Covid-19 Pandemic at Bengkulu, Indonesia. The Backpropagation algorithm was used to improve the possibility of discovering available and potential donors. Furthermore, the distances, age, and length of donation were measured to obtain the right person to donate blood when it needed. The Backpropagation uses three input layers to classify eligible donors, namely age, body, weight, and bias. In addition, the system through its query automatically counts the variables via the Fuzzy Tahani and simultaneously access the vast database.


Reinforcement Learning for Flexibility Design Problems

Wei, Yehua, Zhang, Lei, Zhang, Ruiyi, Si, Shijing, Zhang, Hao, Carin, Lawrence

arXiv.org Artificial Intelligence

Flexibility design problems are a class of problems that appear in strategic decision-making across industries, where the objective is to design a ($e.g.$, manufacturing) network that affords flexibility and adaptivity. The underlying combinatorial nature and stochastic objectives make flexibility design problems challenging for standard optimization methods. In this paper, we develop a reinforcement learning (RL) framework for flexibility design problems. Specifically, we carefully design mechanisms with noisy exploration and variance reduction to ensure empirical success and show the unique advantage of RL in terms of fast-adaptation. Empirical results show that the RL-based method consistently finds better solutions compared to classical heuristics.


Mapping Network States Using Connectivity Queries

Rodríguez, Alexander, Adhikari, Bijaya, González, Andrés D., Nicholson, Charles, Vullikanti, Anil, Prakash, B. Aditya

arXiv.org Artificial Intelligence

Can we infer all the failed components of an infrastructure network, given a sample of reachable nodes from supply nodes? One of the most critical post-disruption processes after a natural disaster is to quickly determine the damage or failure states of critical infrastructure components. However, this is non-trivial, considering that often only a fraction of components may be accessible or observable after a disruptive event. Past work has looked into inferring failed components given point probes, i.e. with a direct sample of failed components. In contrast, we study the harder problem of inferring failed components given partial information of some `serviceable' reachable nodes and a small sample of point probes, being the first often more practical to obtain. We formulate this novel problem using the Minimum Description Length (MDL) principle, and then present a greedy algorithm that minimizes MDL cost effectively. We evaluate our algorithm on domain-expert simulations of real networks in the aftermath of an earthquake. Our algorithm successfully identify failed components, especially the critical ones affecting the overall system performance.


A Review of Emergency Incident Prediction, Resource Allocation and Dispatch Models

Mukhopadhyay, Ayan, Pettet, Geoffrey, Vazirizade, Sayyed, Lu, Di, Baroud, Hiba, Jaimes, Alex, Vorobeychik, Yevgeniy, Kochenderfer, Mykel, Dubey, Abhishek

arXiv.org Artificial Intelligence

Emergency response to incidents such as accidents, medical calls, and fires is one of the most pressing problems faced by communities across the globe. In the last fifty years, researchers have developed statistical, analytical, and algorithmic approaches for designing emergency response management (ERM) systems. In this survey, we present models for incident prediction, resource allocation, and dispatch for emergency incidents. We highlight the strengths and weaknesses of prior work in this domain and explore the similarities and differences between different modeling paradigms. Finally, we present future research directions. To the best of our knowledge, our work is the first comprehensive survey that explores the entirety of ERM systems.


A Graph Theoretic Additive Approximation of Optimal Transport

Lahn, Nathaniel, Mulchandani, Deepika, Raghvendra, Sharath

arXiv.org Machine Learning

Transportation cost is an attractive similarity measure between probability distributions due to its many useful theoretical properties. However, solving optimal transport exactly can be prohibitively expensive. Therefore, there has been significant effort towards the design of scalable approximation algorithms. Previous combinatorial results [Sharathkumar, Agarwal STOC '12, Agarwal, Sharathkumar STOC '14] have focused primarily on the design of strongly polynomial multiplicative approximation algorithms. There has also been an effort to design approximate solutions with additive errors [Cuturi NIPS '13, Altschuler et. al NIPS '17, Dvurechensky et al., ICML '18, Quanrud, SOSA '19] within a time bound that is linear in the size of the cost matrix and polynomial in $C/\delta$; here $C$ is the largest value in the cost matrix and $\delta$ is the additive error. We present an adaptation of the classical graph algorithm of Gabow and Tarjan and provide a novel analysis of this algorithm that bounds its execution time by $O(\frac{n^2 C}{\delta}+ \frac{nC^2}{\delta^2})$. Our algorithm is extremely simple and executes, for an arbitrarily small constant $\varepsilon$, only $\lfloor \frac{2C}{(1-\varepsilon)\delta}\rfloor + 1$ iterations, where each iteration consists only of a Dijkstra search followed by a depth-first search. We also provide empirical results that suggest our algorithm significantly outperforms existing approaches in execution time.


A Heuristic Method for Solving the Problem of Partitioning Graphs with Supply and Demand

Jovanovic, Raka, Bousselham, Abdelkader, Voss, Stefan

arXiv.org Artificial Intelligence

Noname manuscript No. (will be inserted by the editor) Abstract In this paper we present a greedy algorithm for solving the problem of the maximum partitioning of graphs with supply and demand (MPGSD). The goal of the method is to solve the MPGSD for large graphs in a reasonable time limit. This is done by using a two stage greedy algorithm, with two corresponding types of heuristics. The solutions acquired in this way are improved by applying a computationally inexpensive, hill climbing like, greedy correction procedure. In our numeric experiments we analyze different heuristic functions for each stage of the greedy algorithm, and show that their performance is highly dependent on the properties of the specific instance. Our tests show that by exploring a relatively small number of solutions generated by combining different heuristic functions, and applying the proposed correction procedure we can find solutions within only a few percent of the optimal ones. Keywords Graph Partitioning · Greedy Algorithm · Demand vertex · Supply vertex 1 Introduction A wide range of practical problems can be efficiently represented by means of graph partitioning. Present address: Qatar Environment and Energy Research Institute (QEERI), PO Box 5825, Doha, Qatar Abdelkader Bousselham Qatar Environment and Energy Research Institute (QEERI), PO Box 5825, Doha, Qatar Email: abousselham@qf.org.qa In this paper the focus is on the problem of maximum partitioning of a graph with supply and demand (MPGSD). This problem is defined on a graph G, in which each node is either a supply or a demand node. Each vertex v has a corresponding positive number, which is called the supply of node v; otherwise, if v is a demand node, this value would be called demand.