seed 1
Towards Biologically Plausible and Private Gene Expression Data Generation
Chen, Dingfan, Oestreich, Marie, Afonja, Tejumade, Kerkouche, Raouf, Becker, Matthias, Fritz, Mario
Generative models trained with Differential Privacy (DP) are becoming increasingly prominent in the creation of synthetic data for downstream applications. Existing literature, however, primarily focuses on basic benchmarking datasets and tends to report promising results only for elementary metrics and relatively simple data distributions. In this paper, we initiate a systematic analysis of how DP generative models perform in their natural application scenarios, specifically focusing on real-world gene expression data. We conduct a comprehensive analysis of five representative DP generation methods, examining them from various angles, such as downstream utility, statistical properties, and biological plausibility. Our extensive evaluation illuminates the unique characteristics of each DP generation method, offering critical insights into the strengths and weaknesses of each approach, and uncovering intriguing possibilities for future developments. Perhaps surprisingly, our analysis reveals that most methods are capable of achieving seemingly reasonable downstream utility, according to the standard evaluation metrics considered in existing literature. Nevertheless, we find that none of the DP methods are able to accurately capture the biological characteristics of the real dataset. This observation suggests a potential over-optimistic assessment of current methodologies in this field and underscores a pressing need for future enhancements in model design.
Group Cohesion in Multi-Agent Scenarios as an Emergent Behavior
Volkmer, Gianluca Georg Alois, Alsabah, Nabil
The integration of artificial intelligence into multi-agent systems (MAS) has garnered an ever increasing attention among AI researchers. Of special interest are agents that exhibit social behavioral patterns, such as coordination, cooperation and conflict resolution [1]. Thereby, researchers have relied on classical approaches [9; 18; 20]. In recent publications, researchers used reinforcement learning to train their agents in multi-agent environments [4; 13; 28]. This subfield of machine learning allows agents to deduce optimal behavior solely from the problem formulation using a reward function that gives (delayed) feedback on actions. Social behavior, such as cooperation, eventually emerges as agents optimize their behavior to reach a predefined goal. Using AI frameworks that explicitly integrate psychological insights into human behavior might seem as a viable alternative when designing social multi-agent systems. In fact, over the course of the last four decades, cognitive scientists have developed so-called cognitive architectures to provide unified models of cognition and serve as frameworks for introducing human-like behavioral patterns into AI agents [14; 16]. Some cognitive architectures, like Soar [17; 23] and Icarus [15] are purely symbolic: They emulate aspects of planing and reasoning through the vehicle of production rules.
A Neural Network-based SAT-Resilient Obfuscation Towards Enhanced Logic Locking
Hassan, Rakibul, Kolhe, Gaurav, Rafatirad, Setareh, Homayoun, Houman, Dinakarrao, Sai Manoj Pudukotai
Logic obfuscation is introduced as a pivotal defense against multiple hardware threats on Integrated Circuits (ICs), including reverse engineering (RE) and intellectual property (IP) theft. The effectiveness of logic obfuscation is challenged by the recently introduced Boolean satisfiability (SAT) attack and its variants. A plethora of countermeasures has also been proposed to thwart the SAT attack. Irrespective of the implemented defense against SAT attacks, large power, performance, and area overheads are indispensable. In contrast, we propose a cognitive solution: a neural network-based unSAT clause translator, SATConda, that incurs a minimal area and power overhead while preserving the original functionality with impenetrable security. SATConda is incubated with an unSAT clause generator that translates the existing conjunctive normal form (CNF) through minimal perturbations such as the inclusion of pair of inverters or buffers or adding a new lightweight unSAT block depending on the provided CNF. For efficient unSAT clause generation, SATConda is equipped with a multi-layer neural network that first learns the dependencies of features (literals and clauses), followed by a long-short-term-memory (LSTM) network to validate and backpropagate the SAT-hardness for better learning and translation. Our proposed SATConda is evaluated on ISCAS85 and ISCAS89 benchmarks and is seen to defend against multiple state-of-the-art successfully SAT attacks devised for hardware RE. In addition, we also evaluate our proposed SATCondas empirical performance against MiniSAT, Lingeling and Glucose SAT solvers that form the base for numerous existing deobfuscation SAT attacks.
Cross-lingual Approaches for the Detection of Adverse Drug Reactions in German from a Patient's Perspective
Raithel, Lisa, Thomas, Philippe, Roller, Roland, Sapina, Oliver, Möller, Sebastian, Zweigenbaum, Pierre
In this work, we present the first corpus for German Adverse Drug Reaction (ADR) detection in patient-generated content. The data consists of 4,169 binary annotated documents from a German patient forum, where users talk about health issues and get advice from medical doctors. As is common in social media data in this domain, the class labels of the corpus are very imbalanced. This and a high topic imbalance make it a very challenging dataset, since often, the same symptom can have several causes and is not always related to a medication intake. We aim to encourage further multi-lingual efforts in the domain of ADR detection and provide preliminary experiments for binary classification using different methods of zero- and few-shot learning based on a multi-lingual model. When fine-tuning XLM-RoBERTa first on English patient forum data and then on the new German data, we achieve an F1-score of 37.52 for the positive class. We make the dataset and models publicly available for the community.
Self-Tuning Deep Reinforcement Learning
Zahavy, Tom, Xu, Zhongwen, Veeriah, Vivek, Hessel, Matteo, Oh, Junhyuk, van Hasselt, Hado, Silver, David, Singh, Satinder
Reinforcement learning (RL) algorithms often require expensive manual or automated hyperparameter searches in order to perform well on a new domain. This need is particularly acute in modern deep RL architectures which often incorporate many modules and multiple loss functions. In this paper, we take a step towards addressing this issue by using metagradients (Xu et al., 2018) to tune these hyperparameters via differentiable cross validation, whilst the agent interacts with and learns from the environment. We present the Self-Tuning Actor Critic (STAC) which uses this process to tune the hyperparameters of the usual loss function of the IMPALA actor critic agent(Espeholt et. al., 2018), to learn the hyperparameters that define auxiliary loss functions, and to balance trade offs in off policy learning by introducing and adapting the hyperparameters of a novel leaky V-trace operator. The method is simple to use, sample efficient and does not require significant increase in compute. Ablative studies show that the overall performance of STAC improves as we adapt more hyperparameters. When applied to 57 games on the Atari 2600 environment over 200 million frames our algorithm improves the median human normalized score of the baseline from 243% to 364%.