OpenRaiser/Intern-Atlas huggingface dataset:
Reinforcement Learning Guided by Provable Normative Compliance
Venue: arXiv cs.AI 2022
Year: 2022

Reinforcement learning (RL) has shown promise as a tool for engineering safe, ethical, or legal behaviour in autonomous agents. Its use typically relies on assigning punishments to state-action pairs that constitute unsafe or unethical choices. Despite this assignment being a crucial step in this approach, however, there has been limited discussion on generalizing the process of selecting punishments and deciding where to apply them. In this paper, we adopt an approach that leverages an existing framework -- the normative supervisor of (Neufeld et al., 2021) -- during training. This normative supervisor is used to dynamically translate states and the applicable normative system into defeasible deontic logic theories, feed these theories to a theorem prover, and use the conclusions derived to decide whether or not to assign a punishment to the agent. We use multi-objective RL (MORL) to balance the ethical objective of avoiding violations with a non-ethical objective; we will demonstrate that our approach works for a multiplicity of MORL techniques, and show that it is effective regardless of the magnitude of the punishment we assign.
The Weak Supervision Landscape
Venue: arXiv cs.LG 2022
Year: 2022

Many ways of annotating a dataset for machine learning classification tasks that go beyond the usual class labels exist in practice. These are of interest as they can simplify or facilitate the collection of annotations, while not greatly affecting the resulting machine learning model. Many of these fall under the umbrella term of weak labels or annotations. However, it is not always clear how different alternatives are related. In this paper we propose a framework for categorising weak supervision settings with the aim of: (1) helping the dataset owner or annotator navigate through the available options within weak supervision when prescribing an annotation process, and (2) describing existing annotations for a dataset to machine learning practitioners so that we allow them to understand the implications for the learning process. To this end, we identify the key elements that characterise weak supervision and devise a series of dimensions that categorise most of the existing approaches. We show how common settings in the literature fit within the framework and discuss its possible uses in practice.
Acoustics-specific Piano Velocity Estimation
Venue: arXiv cs.SD 2022
Year: 2022

Motivated by the state-of-art psychological research, we note that a piano performance transcribed with existing Automatic Music Transcription (AMT) methods cannot be successfully resynthesized without affecting the artistic content of the performance. This is due to 1) the different mappings between MIDI parameters used by different instruments, and 2) the fact that musicians adapt their way of playing to the surrounding acoustic environment. To face this issue, we propose a methodology to build acoustics-specific AMT systems that are able to model the adaptations that musicians apply to convey their interpretation. Specifically, we train models tailored for virtual instruments in a modular architecture that takes as input an audio recording and the relative aligned music score, and outputs the acoustics-specific velocities of each note. We test different model shapes and show that the proposed methodology generally outperforms the usual AMT pipeline which does not consider specificities of the instrument and of the acoustic environment. Interestingly, such a methodology is extensible in a straightforward way since only slight efforts are required to train models for the inference of other piano parameters, such as pedaling.
When to Go, and When to Explore: The Benefit of Post-Exploration in Intrinsic Motivation
Venue: arXiv cs.LG 2022
Year: 2022

Go-Explore achieved breakthrough performance on challenging reinforcement learning (RL) tasks with sparse rewards. The key insight of Go-Explore was that successful exploration requires an agent to first return to an interesting state ('Go'), and only then explore into unknown terrain ('Explore'). We refer to such exploration after a goal is reached as 'post-exploration'. In this paper we present a systematic study of post-exploration, answering open questions that the Go-Explore paper did not answer yet. First, we study the isolated potential of post-exploration, by turning it on and off within the same algorithm. Subsequently, we introduce new methodology to adaptively decide when to post-explore and for how long to post-explore. Experiments on a range of MiniGrid environments show that post-exploration indeed boosts performance (with a bigger impact than tuning regular exploration parameters), and this effect is further enhanced by adaptively deciding when and for how long to post-explore. In short, our work identifies adaptive post-exploration as a promising direction for RL exploration research.
Near-Field Communications for 6G: Fundamentals, Challenges, Potentials, and Future Directions
Venue: arXiv cs.IT 2022
Year: 2022

Extremely large antenna array (ELAA) is a common feature of several key candidate technologies for sixth-generation mobile networks (6G), such as ultra-massive multiple-input-multiple-output (UM-MIMO), cell-free massive MIMO, reconfigurable intelligent surface (RIS), and terahertz communications. Since the number of antennas is very large for ELAA, the electromagnetic radiation field needs to be modeled by near-field spherical waves, which is opposed to the conventional planar-wave-based radiation model of 5G massive MIMO. As a result, near-field communications will become essential in 6G wireless networks. In this article, we systematically investigate the emerging near-field communication techniques. Firstly, we present the fundamentals of near-field communications and the metric to determine the near-field ranges in typical communication scenarios. Then, we investigate recent studies specific to near-field communications by classifying them into two categories, i.e., techniques addressing the challenges and those exploiting the potentials in near-field regions. Their principles, recent progress, pros and cons are discussed. More importantly, several open problems and future research directions for near-field communications are pointed out. We believe that this article would inspire more innovations for this important research topic of near-field communications for 6G.
$crypto_{lib}$: Comparing and selecting cryptography libraries (long version of EICC 2022 publication)
Venue: arXiv cs.CR 2022
Year: 2022

Selecting a library out of numerous candidates can be a laborious and resource-intensive task. We present the $crypto_{lib}$ index, a tool for decision-makers to choose the best fitting cryptography library for a given context. To define our index, 15 library attributes were synthesized from findings based on a literature review and interviews with decision-makers. These attributes were afterwards validated and weighted via an online survey. In order to create the index value for a given library, the individual attributes are assessed using given evaluation criteria associated with the respective attribute. As a proof of concept and to give a practical usage example, the derivation of the $crypto_{lib}$ values for the libraries Bouncy Castle and Tink are shown in detail. Overall, by tailoring the weighting of the $crypto_{lib}$ attributes to their current use case, decision-makers are enabled to systematically select a cryptography library fitting best to their software project at hand in a guided, repeatable and reliable way.
Low-complexity Near-optimum Symbol Detection Based on Neural Enhancement of Factor Graphs
Venue: arXiv cs.IT 2022
Year: 2022

We consider the application of the factor graph framework for symbol detection on linear inter-symbol interference channels. Based on the Ungerboeck observation model, a detection algorithm with appealing complexity properties can be derived. However, since the underlying factor graph contains cycles, the sum-product algorithm (SPA) yields a suboptimal algorithm. In this paper, we develop and evaluate efficient strategies to improve the performance of the factor graph-based symbol detection by means of neural enhancement. In particular, we consider neural belief propagation and generalizations of the factor nodes as an effective way to mitigate the effect of cycles within the factor graph. By applying a generic preprocessor to the channel output, we propose a simple technique to vary the underlying factor graph in every SPA iteration. Using this dynamic factor graph transition, we intend to preserve the extrinsic nature of the SPA messages which is otherwise impaired due to cycles. Simulation results show that the proposed methods can massively improve the detection performance, even approaching the maximum a posteriori performance for various transmission scenarios, while preserving a complexity which is linear in both the block length and the channel memory.
Understanding the role of single-board computers in engineering and computer science education: A systematic literature review
Venue: arXiv cs.CY 2022
Year: 2022

In the last decade, Single-Board Computers (SBCs) have been employed more frequently in engineering and computer science both to technical and educational levels. Several factors such as the versatility, the low-cost, and the possibility to enhance the learning process through technology have contributed to the educators and students usually employ these devices. However, the implications, possibilities, and constraints of these devices in engineering and Computer Science (CS) education have not been explored in detail. In this systematic literature review, we explore how the SBCs are employed in engineering and computer science and what educational results are derived from their usage in the period 2010-2020 at tertiary education. For that, 154 studies were selected out of n=605 collected from the academic databases Ei Compendex, ERIC, and Inspec. The analysis was carried-out in two phases, identifying, e.g., areas of application, learning outcomes, and students and researchers' perceptions. The results mainly indicate the following aspects: (1) The areas of laboratories and e-learning, computing education, robotics, Internet of Things (IoT), and persons with disabilities gather the studies in the review. (2) Researchers highlight the importance of the SBCs to transform the curricula in engineering and CS for the students to learn complex topics through experimentation in hands-on activities. (3) The typical cognitive learning outcomes reported by the authors are the improvement of the students' grades and the technical skills regarding the topics in the courses. Concerning the affective learning outcomes, the increase of interest, motivation, and engagement are commonly reported by the authors.
TR-MOT: Multi-Object Tracking by Reference
Venue: arXiv cs.CV 2022
Year: 2022

Multi-object Tracking (MOT) generally can be split into two sub-tasks, i.e., detection and association. Many previous methods follow the tracking by detection paradigm, which first obtain detections at each frame and then associate them between adjacent frames. Though with an impressive performance by utilizing a strong detector, it will degrade their detection and association performance under scenes with many occlusions and large motion if not using temporal information. In this paper, we propose a novel Reference Search (RS) module to provide a more reliable association based on the deformable transformer structure, which is natural to learn the feature alignment for each object among frames. RS takes previous detected results as references to aggregate the corresponding features from the combined features of the adjacent frames and makes a one-to-one track state prediction for each reference in parallel. Therefore, RS can attain a reliable association coping with unexpected motions by leveraging visual temporal features while maintaining the strong detection performance by decoupling from the detector. Our RS module can also be compatible with the structure of the other tracking by detection frameworks. Furthermore, we propose a joint training strategy and an effective matching pipeline for our online MOT framework with the RS module. Our method achieves competitive results on MOT17 and MOT20 datasets.
Generation of Speaker Representations Using Heterogeneous Training Batch Assembly
Venue: arXiv cs.SD 2022
Year: 2022

In traditional speaker diarization systems, a well-trained speaker model is a key component to extract representations from consecutive and partially overlapping segments in a long speech session. To be more consistent with the back-end segmentation and clustering, we propose a new CNN-based speaker modeling scheme, which takes into account the heterogeneity of the speakers in each training segment and batch. We randomly and synthetically augment the training data into a set of segments, each of which contains more than one speaker and some overlapping parts. A soft label is imposed on each segment based on its speaker occupation ratio, and the standard cross entropy loss is implemented in model training. In this way, the speaker model should have the ability to generate a geometrically meaningful embedding for each multi-speaker segment. Experimental results show that our system is superior to the baseline system using x-vectors in two speaker diarization tasks. In the CALLHOME task trained on the NIST SRE and Switchboard datasets, our system achieves a relative reduction of 12.93% in DER. In Track 2 of CHiME-6, our system provides 13.24%, 12.60%, and 5.65% relative reductions in DER, JER, and WER, respectively.
End-to-End Table Question Answering via Retrieval-Augmented Generation
Venue: arXiv cs.CL 2022
Year: 2022

Most existing end-to-end Table Question Answering (Table QA) models consist of a two-stage framework with a retriever to select relevant table candidates from a corpus and a reader to locate the correct answers from table candidates. Even though the accuracy of the reader models is significantly improved with the recent transformer-based approaches, the overall performance of such frameworks still suffers from the poor accuracy of using traditional information retrieval techniques as retrievers. To alleviate this problem, we introduce T-RAG, an end-to-end Table QA model, where a non-parametric dense vector index is fine-tuned jointly with BART, a parametric sequence-to-sequence model to generate answer tokens. Given any natural language question, T-RAG utilizes a unified pipeline to automatically search through a table corpus to directly locate the correct answer from the table cells. We apply T-RAG to recent open-domain Table QA benchmarks and demonstrate that the fine-tuned T-RAG model is able to achieve state-of-the-art performance in both the end-to-end Table QA and the table retrieval tasks.
Mapping Topics in 100,000 Real-life Moral Dilemmas
Venue: arXiv cs.SI 2022
Year: 2022

Moral dilemmas play an important role in theorizing both about ethical norms and moral psychology. Yet thought experiments borrowed from the philosophical literature often lack the nuances and complexity of real life. We leverage 100,000 threads -- the largest collection to date -- from Reddit's r/AmItheAsshole to examine the features of everyday moral dilemmas. Combining topic modeling with evaluation from both expert and crowd-sourced workers, we discover 47 finer-grained, meaningful topics and group them into five meta-categories. We show that most dilemmas combine at least two topics, such as family and money. We also observe that the pattern of topic co-occurrence carries interesting information about the structure of everyday moral concerns: for example, the generation of moral dilemmas from nominally neutral topics, and interaction effects in which final verdicts do not line up with the moral concerns in the original stories in any simple way. Our analysis demonstrates the utility of a fine-grained data-driven approach to online moral dilemmas, and provides a valuable resource for researchers aiming to explore the intersection of practical and theoretical ethics.
Snapshot Visualization of Complex Graphs with Force-Directed Algorithms
Venue: arXiv cs.DS 2022
Year: 2022

Force-directed algorithms are widely used for visualizing graphs. However, these algorithms are computationally expensive in producing good quality layouts for complex graphs. The layout quality is largely influenced by execution time and methods' input parameters especially for large complex graphs. The snapshots of visualization generated from these algorithms are useful in presenting the current view or a past state of an information on timeslices. Therefore, researchers often need to make a trade-off between the quality of visualization and the selection of appropriate force-directed algorithms. In this paper, we evaluate the quality of snapshots generated from 7 force-directed algorithms in terms of number of edge crossing and the standard deviations of edge length. Our experimental results showed that KK, FA2 and DH algorithms cannot produce satisfactory visualizations for large graphs within the time limit. KK-MS-DS algorithm can process large and planar graphs but it does not perform well for graphs with low average degrees. KK-MS algorithm produces better visualizations for sparse and non-clustered graphs than KK-MS-DS algorithm.
Cyberbullying Indicator as a Precursor to a Cyber Construct Development
Venue: arXiv cs.CR 2022
Year: 2022

The current global pandemic occasioned by the SARS-CoV-2 virus has been attributed, partially, to the growing range of cyber vises within the cyber ecosystem. One area of such impact is the increasing tendencies of cyber-bullying among students. Cyberbullying -- the act of subjugating others using a cyber platform -- is a growing concern among educators, especially in High-S chools. Whilst studies have been carried out towards understanding this menace, the approach towards id entifying indicators of cyberbullying is largely missing in the literature. To address this research gap, this study proposed a cyberbullying framework based on the identification of some observable behavioral indicators. Using a self-administered measurement instrument from 30-respondents, the study observed the probability of a cyberbully construct, as a potential measure of the presence of cyberbullying; a probability that has been largely ignored in extant literature. This observation presents a veritable tool for the development of an active and integrated learning platform void of abuse among students. Furthermore, within the cyber education ecosystem, a cyberbullying construct would provide a mechanism for the development of an appropriate online learning platform, which would be useful to the information system and cyber education research communities.
Suffix tree-based linear algorithms for multiple prefixes, single suffix counting and listing problems
Venue: arXiv cs.DS 2022
Year: 2022

Given two strings $T$ and $S$ and a set of strings $P$, for each string $p \in P$, consider the unique substrings of $T$ that have $p$ as their prefix and $S$ as their suffix. Two problems then come to mind; the first problem being the counting of such substrings, and the second problem being the problem of listing all such substrings. In this paper, we describe linear-time, linear-space suffix tree-based algorithms for both problems. More specifically, we describe an $O(|T| + |P|)$ time algorithm for the counting problem, and an $O(|T| + |P| + \#(ans))$ time algorithm for the listing problem, where $\#(ans)$ refers to the number of strings being listed in total, and $|P|$ refers to the total length of the strings in $P$. We also consider the reversed version of the problems, where one prefix condition string and multiple suffix condition strings are given instead, and similarly describe linear-time, linear-space algorithms to solve them.
Desenvolvimento de ferramenta de simulação para auxílio no ensino da disciplina de robótica industrial
Venue: arXiv cs.RO 2022
Year: 2022

Currently, robotics is one of the fastest growing areas not only in the industrial sector but also in the consumer and service sectors. Several areas benefit from the technological advancement of robotics, especially the industrial area those benefits from gains in productivity and quality. However, to supply this growing demand it is necessary for the newly graduated professionals to have a deeper understanding of how to design and control a robotic manipulator. It is logical that in order to obtain this more in-depth knowledge of robotics, it is necessary to have an experience with a real robotic manipulator, since the practice is a much more efficient way of learning than theory. However, it is known that a robotic arm is not a cheap investment, and its maintenance is not cheap either. Therefore, many educational institutions are not able to provide this type of experience to their students. With this in mind, and through the use of Unity 3D, which is a game development software, a robotic arm simulator has been developed to correlate classroom theory with what actually happens in practice. The robotic manipulators implemented on this simulator can be controlled by both inverse kinematics (which is the industry standard) and direct kinematics.
Assessing the risk of re-identification arising from an attack on anonymised data
Venue: arXiv cs.LG 2022
Year: 2022

Objective: The use of routinely-acquired medical data for research purposes requires the protection of patient confidentiality via data anonymisation. The objective of this work is to calculate the risk of re-identification arising from a malicious attack to an anonymised dataset, as described below. Methods: We first present an analytical means of estimating the probability of re-identification of a single patient in a k-anonymised dataset of Electronic Health Record (EHR) data. Second, we generalize this solution to obtain the probability of multiple patients being re-identified. We provide synthetic validation via Monte Carlo simulations to illustrate the accuracy of the estimates obtained. Results: The proposed analytical framework for risk estimation provides re-identification probabilities that are in agreement with those provided by simulation in a number of scenarios. Our work is limited by conservative assumptions which inflate the re-identification probability. Discussion: Our estimates show that the re-identification probability increases with the proportion of the dataset maliciously obtained and that it has an inverse relationship with the equivalence class size. Our recursive approach extends the applicability domain to the general case of a multi-patient re-identification attack in an arbitrary k-anonymisation scheme. Conclusion: We prescribe a systematic way to parametrize the k-anonymisation process based on a pre-determined re-identification probability. We observed that the benefits of a reduced re-identification risk that come with increasing k-size may not be worth the reduction in data granularity when one is considering benchmarking the re-identification probability on the size of the portion of the dataset maliciously obtained by the adversary.
Learning from few examples with nonlinear feature maps
Venue: arXiv cs.LG 2022
Year: 2022

In this work we consider the problem of data classification in post-classical settings were the number of training examples consists of mere few data points. We explore the phenomenon and reveal key relationships between dimensionality of AI model's feature space, non-degeneracy of data distributions, and the model's generalisation capabilities. The main thrust of our present analysis is on the influence of nonlinear feature transformations mapping original data into higher- and possibly infinite-dimensional spaces on the resulting model's generalisation capabilities. Subject to appropriate assumptions, we establish new relationships between intrinsic dimensions of the transformed data and the probabilities to learn successfully from few presentations.