Towards collaborative dialogue in Minecraft

This dissertation describes our work in building interactive agents that can communicate with humans to collaboratively solve tasks in grounded scenarios. To investigate the challenges of building such agents, we define a novel instantiation of a situated, Minecraft-based, Collaborative Building Task in which one player (A, the Architect) is shown a target structure, denoted Target, and needs to instruct the other player (B, the Builder) to build a copy of this structure, denoted Built, in a predefined build region. While both players can interact asynchronously via a chat interface, we define the roles to be asymmetric: A can observe B and Target, but is invisible and cannot place blocks; meanwhile, B can freely place and remove blocks, but has no explicit knowledge of the target structure. Each agent requires a different set of abilities in order to be successful at this task: specifically, A's main challenges arise in the task of generating situated instructions by comparing Built and Target, while B's responsibilities focus mainly on comprehending A's situated instructions using both dialogue and world context. Both agents must be able to interact asynchronously in an evolving dialogue context and a dynamic world state within which they are embodied. In this work, we specifically examine how well end-to-end neural models can learn to be instruction givers (i.e., Architects) from a limited amount of real human-human data. In order to examine how humans complete the Collaborative Building Task, as well as use human-human data as a gold standard for training and evaluating models, we present the Minecraft Dialogue Corpus, a collection of 509 conversations and game logs. We then introduce baseline models for the challenging subtask of Architect utterance generation, and evaluate them offline, using both automated metrics and human evaluation. We show that while conditioning our model on a simple representation of the world gives our model improved ability to generate correct instructions, there are still many obvious shortcomings, and it is difficult for these models to learn the large variety of abilities needed to be successful Architects in an entirely end-to-end manner. To combat this, we show that including meaningful, structured inputs about the world and discourse state as additional inputs -- specifically, by adding oracle information about the Builder's next actions, as well as enriching our linguistic representation with Architect dialogue acts -- improves the performance of our utterance generation models. We also augment the data with shape information by pretraining 3D shape localization models on synthetically generated block configurations. Finally, we integrate Architect utterance generation models into actual Minecraft agents and evaluate them in a fully interactive setting

Semi-automated Ontology Generation for Biocuration and Semantic Search

Background: In the life sciences, the amount of literature and experimental data grows at a tremendous rate. In order to effectively access and integrate these data, biomedical ontologies – controlled, hierarchical vocabularies – are being developed. Creating and maintaining such ontologies is a difficult, labour-intensive, manual process. Many computational methods which can support ontology construction have been proposed in the past. However, good, validated systems are largely missing. Motivation: The biocuration community plays a central role in the development of ontologies. Any method that can support their efforts has the potential to have a huge impact in the life sciences. Recently, a number of semantic search engines were created that make use of biomedical ontologies for document retrieval. To transfer the technology to other knowledge domains, suitable ontologies need to be created. One area where ontologies may prove particularly useful is the search for alternative methods to animal testing, an area where comprehensive search is of special interest to determine the availability or unavailability of alternative methods. Results: The Dresden Ontology Generator for Directed Acyclic Graphs (DOG4DAG) developed in this thesis is a system which supports the creation and extension of ontologies by semi-automatically generating terms, definitions, and parent-child relations from text in PubMed, the web, and PDF repositories. The system is seamlessly integrated into OBO-Edit and Protégé, two widely used ontology editors in the life sciences. DOG4DAG generates terms by identifying statistically significant noun-phrases in text. For definitions and parent-child relations it employs pattern-based web searches. Each generation step has been systematically evaluated using manually validated benchmarks. The term generation leads to high quality terms also found in manually created ontologies. Definitions can be retrieved for up to 78% of terms, child ancestor relations for up to 54%. No other validated system exists that achieves comparable results. To improve the search for information on alternative methods to animal testing an ontology has been developed that contains 17,151 terms of which 10% were newly created and 90% were re-used from existing resources. This ontology is the core of Go3R, the first semantic search engine in this field. When a user performs a search query with Go3R, the search engine expands this request using the structure and terminology of the ontology. The machine classification employed in Go3R is capable of distinguishing documents related to alternative methods from those which are not with an F-measure of 90% on a manual benchmark. Approximately 200,000 of the 19 million documents listed in PubMed were identified as relevant, either because a specific term was contained or due to the automatic classification. The Go3R search engine is available on-line under www.Go3R.org

Migration Research in a Digitized World

This open access book explores implications of the digital revolution for migration scholars’ methodological toolkit. New information and communication technologies hold considerable potential to improve the quality of migration research by originating previously non-viable solutions to a myriad of methodological challenges in this field of study. Combining cutting-edge migration scholarship and methodological expertise, the book addresses a range of crucial issues related to both researcher-designed data collections and the secondary use of “big data”, highlighting opportunities as well as challenges and limitations. A valuable source for students and scholars engaged in migration research, the book will also be of keen interest to policymakers

Migration Research in a Digitized World: Using Innovative Technology to Tackle Methodological Challenges

This book explores implications of the digital revolution for migration scholars' methodological toolkit. New information and communication technologies hold considerable potential to improve the quality of migration research by originating previously non-viable solutions to a myriad of methodological challenges in this field of study. Combining cutting-edge migration scholarship and methodological expertise, the book addresses a range of crucial issues related to both researcher-designed data collections and the secondary use of "big data", highlighting opportunities as well as challenges and limitations. A valuable source for students and scholars engaged in migration research, the book will also be of keen interest to policymakers

Migration Research in a Digitized World: Using Innovative Technology to Tackle Methodological Challenges

This open access book explores implications of the digital revolution for migration scholars’ methodological toolkit. New information and communication technologies hold considerable potential to improve the quality of migration research by originating previously non-viable solutions to a myriad of methodological challenges in this field of study. Combining cutting-edge migration scholarship and methodological expertise, the book addresses a range of crucial issues related to both researcher-designed data collections and the secondary use of “big data”, highlighting opportunities as well as challenges and limitations. A valuable source for students and scholars engaged in migration research, the book will also be of keen interest to policymakers

Proceedings of the 21st Conference on Formal Methods in Computer-Aided Design – FMCAD 2021

The Conference on Formal Methods in Computer-Aided Design (FMCAD) is an annual conference on the theory and applications of formal methods in hardware and system verification. FMCAD provides a leading forum to researchers in academia and industry for presenting and discussing groundbreaking methods, technologies, theoretical results, and tools for reasoning formally about computing systems. FMCAD covers formal aspects of computer-aided system design including verification, specification, synthesis, and testing

Algorithms based on spider daddy long legs for finding the optimal route in securing mobile ad hoc networks

Mobile ad hoc networks (MANETs) are wireless networks that are subject to severe attacks, such as the black hole attack. One of the goals in the research is to find a method to prevent black hole attacks without decreasing network throughput or increasing routing overhead. The routing mechanism in define uses route requests (RREQs; for discovering routes) and route replies (RREPs; for receiving paths). However, this mechanism is vulnerable to attacks by malicious black hole nodes. The mechanism is developed to find the shortest secure path and to reduce overhead using the information that is available in the routing tables as an input to propose a more complex nature-inspired algorithm. The new method is called the Daddy Long-Legs Algorithm (PGO-DLLA), which modifies the standard AODV and optimizes the routing process. This method avoids dependency exclusively on the hop counts and destination sequence numbers (DSNs) that are exploited by malicious nodes in the standard AODV protocol. The experiment by performance metrics End-to-End delay and packet delivery ratio are compared in order to determine the best effort traffic. The results showed the PGO-DLLA improvement of the shortest and secure routing from black hole attack in MANET. In addition, the results indicate better performance than the related works algorithm with respect to all metrics excluding throughput which AntNet is best in routing when the pause time be more than 40 seconds. PGODLLA is able to improve the route discovery against the black hole attacks in AODV. Experiments in this thesis have shown that PGO-DLLA is able to reduce the normalized routing load, end-to-end delay, and packet loss and has a good throughput and packet delivery ratio when compared with the standard AODV protocol, BAODV protocol, and the current related protocols that enhance the routing security of the AODV protocols

Proceedings of the 7th Sound and Music Computing Conference

Proceedings of the SMC2010 - 7th Sound and Music Computing Conference, July 21st - July 24th 2010