range constraint
AdaMS: Deep Metric Learning with Adaptive Margin and Adaptive Scale for Acoustic Word Discrimination
Many recent loss functions in deep metric learning are expressed with logarithmic and exponential forms, and they involve margin and scale as essential hyper-parameters. Since each data class has an intrinsic characteristic, several previous works have tried to learn embedding space close to the real distribution by introducing adaptive margins. However, there was no work on adaptive scales at all. We argue that both margin and scale should be adaptively adjustable during the training. In this paper, we propose a method called Adaptive Margin and Scale (AdaMS), where hyper-parameters of margin and scale are replaced with learnable parameters of adaptive margins and adaptive scales for each class. Our method is evaluated on Wall Street Journal dataset, and we achieve outperforming results for word discrimination tasks.
Program Transfer and Ontology Awareness for Semantic Parsing in KBQA
Cao, Shulin, Shi, Jiaxin, Yao, Zijun, Hou, Lei, Li, Juanzi, Xiao, Jinghui
Semantic parsing in KBQA aims to parse natural language questions into logical forms, whose execution against a knowledge base produces answers. Learning semantic parsers from question-answer pairs requires searching over a huge space of logical forms for ones consistent with answers. Current methods utilize various prior knowlege or entity-level KB constraints to reduce the search space. In this paper, we investigate for the first time prior knowledge from external logical form annotations and ontology-level constraints. We design a hierarchical architecture for program transfer, and propose an ontology-guided pruning algorithm to reduce the search space. The experiments on ComplexWebQuestions show that our method improves the state-of-the-art F1 score from 44.0% to 58.7%, with an absolute gain of 14.7%, which demonstrates the effectiveness of program transfer and ontology awareness.
Robust Multi-Agent Path Finding and Executing
Atzmon, Dor (Ben-Gurion University) | Stern, Roni (Ben-Gurion University) | Felner, Ariel (Ben-Gurion University) | Wagner, Glenn (Carnegie Mellon University) | Barták, Roman (Charles University) | Zhou, Neng-Fa (CUNY Brooklyn College)
Multi-agent path-finding (MAPF) is the problem of finding a plan for moving a set of agents from their initial locations to their goals without collisions. Following this plan, however, may not be possible due to unexpected events that delay some of the agents. In this work, we propose a holistic solution for MAPF that is robust to such unexpected delays. First, we introduce the notion of a k-robust MAPF plan, which is a plan that can be executed even if a limited number (k) of delays occur. We propose sufficient and required conditions for finding a k-robust plan, and show how to convert several MAPF solvers to find such plans. Then, we propose several robust execution policies. An execution policy is a policy for agents executing a MAPF plan. An execution policy is robust if following it guarantees that the agents reach their goals even if they encounter unexpected delays. Several classes of such robust execution policies are proposed and evaluated experimentally. Finally, we present robust execution policies for cases where communication between the agents may also be delayed. We performed an extensive experimental evaluation in which we compared different algorithms for finding robust MAPF plans, compared different ro- bust execution policies, and studied the interplay between having a robust plan and the performance when using a robust execution policy.
k-Robust Multi-Agent Path Finding
Atzmon, Dor (Ben-Gurion University of the Negev) | Felner, Ariel (Ben-Gurion University of the Negev) | Stern, Roni (Ben-Gurion University of the Negev) | Wagner, Glenn (Carnegie Mellon University) | Barták, Roman (Charles University) | Zhou, Neng-Fa (City University of New York)
In the multi-agent path-finding (MAPF) problem a plan is needed to move a set of agents from their initial location to their goals without collisions. In this paper we introduce and study the k -robust MAPF problem, where we seek a plan that is robust to k unexpected delays per agent. We say that a plan π is k -robust if it does not have any k - delay conflicts. Informally, this means that no conflicts will occur even if some of the agents are delayed by up to k time steps. The problem we address in this paper is how to find optimal sum-of-costs k -robust plans.
Range and Roots: Two Common Patterns for Specifying and Propagating Counting and Occurrence Constraints
Bessiere, Christian, Hebrard, Emmanuel, Hnich, Brahim, Kiziltan, Zeynep, Walsh, Toby
We propose Range and Roots which are two common patterns useful for specifying a wide range of counting and occurrence constraints. We design specialised propagation algorithms for these two patterns. Counting and occurrence constraints specified using these patterns thus directly inherit a propagation algorithm. To illustrate the capabilities of the Range and Roots constraints, we specify a number of global constraints taken from the literature. Preliminary experiments demonstrate that propagating counting and occurrence constraints using these two patterns leads to a small loss in performance when compared to specialised global constraints and is competitive with alternative decompositions using elementary constraints.