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 SRI International


A Recap of the AAAI and IAAI 2018 Conferences and the EAAI Symposium

AI Magazine

The 2018 AAAI Conference on Artificial Intelligence, the 2018 Innovative Applications of Artificial Intelligence, and the 2018 Symposium on Educational Advances in Artificial Intelligence were held February 2โ€“7, 2018 at the Hilton New Orleans Riverside, New Orleans, Louisiana, USA. ย This report, based on the prefaces contained in the AAAI-18 proceedings and program, summarizes the events of the conference.


ATOL: A Framework for Automated Analysis and Categorization of the Darkweb Ecosystem

AAAI Conferences

We present a framework for automated analysis and categorization of .onion websites in the darkweb to facilitate analyst situational awareness of new content that emerges from this dynamic landscape. Over the last two years, our team has developed a large-scale darkweb crawling infrastructure called OnionCrawler that acquires new onion domains on a daily basis, and crawls and indexes millions of pages from these new and previously known .onion sites. It stores this data into a research repository designed to help better understand Torโ€™s hidden service ecosystem. The analysis component of our framework is called Automated Tool for Onion Labeling (ATOL), which introduces a two-stage thematic labeling strategy: (1) it learns descriptive and discriminative keywords for different categories, and (2) uses these terms to map onion site content to a set of thematic labels. We also present empirical results of ATOL and our ongoing experimentation with it, as we have gained experience applying it to the entirety of our darkweb repository, now over 70 million indexed pages. We find that ATOL can perform site-level thematic label assignment more accurately than keywordbased schemes developed by domain experts โ€” we expand the analyst-provided keywords using an automatic keyword discovery algorithm, and get 12% gain in accuracy by using a machine learning classification model. We also show how ATOL can discover categories on previously unlabeled onions and discuss applications of ATOL in supporting various analyses and investigations of the darkweb.


Trusted Machine Learning: Model Repair and Data Repair for Probabilistic Models

AAAI Conferences

When machine learning algorithms are used in life-critical or mission-critical applications (e.g., self driving cars, cyber security, surgical robotics), it is important to ensure that they provide some high-level correctness guarantees. We introduce a paradigm called Trusted Machine Learning (TML) with the goal of making learning techniques more trustworthy. We outline methods that show how symbolic analysis (specifi- cally parametric model checking) can be used to learn the dynamical model of a system where the learned model satis- fies correctness requirements specified in the form of temporal logic properties (e.g., safety, liveness). When a learned model does not satisfy the desired guarantees, we try two approaches: (1) Model Repair, wherein we modify a learned model directly, and (2) Data Repair, wherein we modify the data so that re-learning from the modified data will result in a trusted model. Model Repair tries to make the minimal changes to the trained model while satisfying the properties, whereas Data Repair tries to make the minimal changes to the dataset used to train the model for ensuring satisfaction of the properties. We show how the Model Repair and Data Repair problems can be solved for the case of probabilistic models, specifically Discrete-Time Markov Chains (DTMC) or Markov Decision Processes (MDP), when the desired properties are expressed in Probabilistic Computation Tree Logic (PCTL). Specifically, we outline how the parameter learning problem in the probabilistic Markov models under temporal logic constraints can be equivalently expressed as a non-linear optimization with non-linear rational constraints, by performing symbolic transformations using a parametric model checker. We illustrate the approach on two case studies: a controller for automobile lane changing, and query router for a wireless sensor network.


Zero-Shot Event Detection by Multimodal Distributional Semantic Embedding of Videos

AAAI Conferences

We propose a new zero-shot Event-Detection method by Multi-modal Distributional Semantic embedding of videos. Our model embeds object and action concepts as well as other available modalities from videos into a distributional semantic space. To our knowledge, this is the first Zero-Shot event detection model that is built on top of distributional semantics and extends it in the following directions: (a) semantic embedding of multimodal information in videos (with focus on the visual modalities), (b) semantic embedding of concepts definitions, and (c) retrieve videos by free text event query (e.g., "changing a vehicle tire") based on their content. We first embed the video into the multi-modal semantic space and then measure the similarity between videos with the event query in free text form. We validated our method on the large TRECVID MED (Multimedia Event Detection) challenge. Using only the event title as a query, our method outperformed the state-the-art that uses big descriptions from 12.6\% to 13.5\% with MAP metric and from 0.73 to 0.83 with ROC-AUC metric. It is also an order of magnitude faster.


A Prototype Intelligent Assistant to Help Dysphagia Patients Eat Safely At Home

AAAI Conferences

For millions of people with swallowing disorders, preventing potentially deadly aspiration pneumonia requires following prescribed safe eating strategies. But adherence is poor, and caregiversโ€™ ability to encourage adherence is limited by the onerous and socially aversive need to monitoring anotherโ€™s eating. We have developed an early prototype for an intelligent assistant that monitors adherence and provides feedback to the patient, and tested monitoring precision with healthy subjects for one strategy called a โ€œchin tuck.โ€ Results indicate that adaptations of current generation machine vision and personal assistant technologies could effectively monitor chin tuck adherence, and suggest the feasibility of a more general assistant that encourages adherence to a wide range of safe eating strategies.


Natural Language Access to Data: It Takes Common Sense!

AAAI Conferences

Commonsense reasoning proves to be an essential tool for natural-language access to data. In a deductive approach to this problem, language processing technology translates English queries into a first-order logical form, which is regarded as a conjecture to be established by a theorem prover. Subject domain knowledge is encoded in an axiomatic theory equipped with links to appropriate databases. Commonsense reasoning is necessary to disambiguate the query, to connect the query with relevant tables in the databases, to deal with logical relationships in the query, and to achieve interoperability between disparate databases. This is illustrated with examples from a proof-of-concept system called Quest, which deals with queries over business enterprise data for an industrial QA system.


The SRI BioFrustration Corpus: Audio, Video, and Physiological Signals for Continuous User Modeling

AAAI Conferences

We describe the SRI BioFrustration Corpus, an in-progress corpus of time-aligned audio, video, and autonomic nervous system signals recorded while users interact with a dialog system to make returns of faulty consumer items. The corpus offers two important advantages for the study of turn-taking under emotion. First, it contains state-of-the-art ECG, skin conductance, blood pressure, and respiration signals, along with multiple audio channels and video channels. Second, the collection paradigm is carefully controlled. Though the users believe they are interacting with an empathetic system, in reality the system afflicts each subject with an identical history of "frustration inducers." This approach enables detailed within- and across-speaker comparisons of the effect of physiological state on user behavior. Continuous signal recording enables studying the effect of frustration inducers with respect to speech-based system-directed turns, inter-turn regions, and system text-to-speech responses.


Enhanced End-of-Turn Detection for Speech to a Personal Assistant

AAAI Conferences

Speech to personal assistants (e.g., reminders, calendar entries, messaging, voice search) is often uttered under cognitive load, causing nonfinal pausing that can result in premature recognition cut-offs. Prior research suggests that prepausal features can discriminate final from nonfinal pauses, but it does not reveal how speakers would behave if given longer to pause. To this end, we collected and compared two elicitation corpora differing in naturalness and task complexity. The Template Corpus (4409 nonfinal pauses) uses keyword-based prompts; the Freeform Corpus (8061 nonfinal pauses) elicits open-ended speech. While nonfinal pauses are longer and twice as frequent in the Freeform data, prepausal feature modelling is roughly equally effective in both corpora. At a response latency of 100 ms, prepausal features modelled by an SVM reduced cut-off rates from 100% to 20% for both corpora. Results have implications for enhancing turn-taking efficiency and naturalness in personal-assistant technology.


Representing States in a Biology Textbook

AAAI Conferences

Representing biology textbook knowledge involves handling numerous concepts that have multiple possible states, for example, developmental states such as embryo, juvenile and larva; system states such as homeostasis and equilibrium; states of chromosomes such as chromatin, nicked, etc. Though substantial research exists on formalisms for representing states, relatively less work exists on ontologically representing them in a complex domain. Our findings include: (a) the word state in natural language is used with both entities and events which requires that we generalize the traditional definition of state to distinguish between an entity state and an event state; (b) an abstract modeling pattern called the process flow diagram that provides a practically achievable target for the output of natural language processing programs, and enables knowledge authoring by domain experts that can be compiled into a well-known background theory based on action languages. The background theory, combined with reasoning methods from the action language, allows building tools that simulate processes and answer sophisticated questions about process interruptions.


Achieving Intelligence Using Prototypes, Composition, and Analogy

AAAI Conferences

In this paper, I summarize the results of a decade-plus of research and development driven by the vision that human knowledge can be grounded in a small number of prototypical components that can be extended through composition and analogy. These ideas have been embodied in a system called AURA, which has been used to engineer an expressive knowledge base for an intelligent biology textbook. The focus of the current paper is to abstract away from the specifics and, to instead describe the core ideas in such a manner that they can be transferred and applied in different contexts, and to relate those ideas to the ongoing research by others.