Reviewerly/exHarmony huggingface dataset:
Bot or not?

Many empirical studies focus on socio-technical activity in social coding platforms such as GitHub, for example to study the onboarding, abandonment, productivity and collaboration among team members. Such studies face the difficulty that GitHub activity can also be generated automatically by bots of a different nature. It therefore becomes imperative to distinguish such bots from human users. We propose an automated approach to detect bots in GitHub pull request (PR) activity. Relying on the assumption that bots contain repetitive message patterns in their PR comments, we analyse the similarity between multiple messages from the same GitHub identity, using a clustering method that combines the Jaccard and Levenshtein distance. We empirically evaluate our approach by analysing 20,090 PR comments of 250 users and 42 bots in 1,262 GitHub repositories. Our results show that the method is able to clearly separate bots from human users.
Deep Unsupervised Self-Evolutionary Hashing for Image Retrieval

Hashing methods have proven to be effective in the field of large-scale image retrieval. In recent years, the performance of hashing algorithms based on deep learning has greatly exceeded that of non-deep methods. However, most of the outstanding hashing methods are supervised models that heavily rely on annotated labels. In order to circumvent the huge overhead of labeling large-scale datasets, some unsupervised hashing algorithms have been proposed, such as pseudo labels and pseudo pairs. Since the image labels are strictly unavailable, some hyper-parameters in these methods are difficult to be selected, e.g., the final result is very sensitive to the picked number of categories or the chosen threshold of similarity for pairs. In addition, the calculation of pseudo-labels in high-dimensional space is not only computationally complex, but also has low precision. Therefore, in order to alleviate these issues in this paper, we propose a simple but effective Deep Unsupervised Self-evolutionary Hashing (DUSH) algorithm, which utilizes a curriculum learning strategy to iteratively select pseudo pairs from easy to hard in low dimensional Hamming space. Extensive experiments are conducted on four popular datasets, including two single-label datasets and two multi-label datasets, and the results show that our method can significantly outperform the state-of-the-art methods.
An ASP approach for reasoning in a concept-aware multipreferential lightweight DL

Abstract In this paper we develop a concept aware multi-preferential semantics for dealing with typicality in description logics, where preferences are associated with concepts, starting from a collection of ranked TBoxes containing defeasible concept inclusions. Preferences are combined to define a preferential interpretation in which defeasible inclusions can be evaluated. The construction of the concept-aware multipreference semantics is related to Brewka’s framework for qualitative preferences. We exploit Answer Set Programming (in particular, asprin ) to achieve defeasible reasoning under the multipreference approach for the lightweight description logic ξ $\mathcal L_ \bot ^ + $ .
Agile-Concurrent hybrid: A framework for concurrent product development using Scrum

Agile development became very popular at the beginning of the 21st century when the Manifesto for Agile Software Development was released. Since then, it has been predominant in the software industry and has been increasingly transferred to the development of physical products due to its great success. There are many studies on Agile-Stage-Gate hybrids that combine agile Scrum and the traditional Stage-Gate model, however no research has been found that addresses a direct integration of Scrum into a concurrent product development model in a similar way. In this paper, we therefore examine the possibility of introducing Scrum into the concurrent product development and propose a Scrum framework for an Agile-Concurrent hybrid. We propose that the framework for concurrent development remains unchanged: the stages overlap and the track-and-loop approach is preserved, while Scrum is proposed for the execution of day-to-day work. The main advantage of the proposed hybrid is that after each iteration the customer reviews the results of an entire loop, not just of one stage, which enables a broader understanding of the progress and facilitates a more extensive feedback. A quicker resolution of discrepancies, and a faster and more effective response to change is thus ensured. In the paper, the needed organizational changes and potential implementation issues are also discussed.
TAFA: Two-headed Attention Fused Autoencoder for Context-Aware Recommendations

Collaborative filtering with implicit feedback is a ubiquitous class of recommendation problems where only positive interactions such as purchases or clicks are observed. Autoencoder-based recommendation models have shown strong performance on many implicit feedback benchmarks. However, these models tend to suffer from popularity bias making recommendations less personalized. User-generated reviews contain a rich source of preference information, often with specific details that are important to each user, and can help mitigate the popularity bias. Since not all reviews are equally useful, existing work has been exploring various forms of attention to distill relevant information. In the majority of proposed approaches, representations from implicit feedback and review branches are simply concatenated at the end to generate predictions. This can prevent the model from learning deeper correlations between the two modalities and affect prediction accuracy. To address these problems, we propose a novel Two-headed Attention Fused Autoencoder (TAFA) model that jointly learns representations from user reviews and implicit feedback to make recommendations. We apply early and late modality fusion which allows the model to fully correlate and extract relevant information from both input sources. To further combat popularity bias, we leverage the Noise Contrastive Estimation (NCE) objective to “de-popularize” the fused user representation via a two-headed decoder architecture. Empirically, we show that TAFA outperforms leading baselines on multiple real-world benchmarks. Moreover, by tracing attention weights back to reviews we can provide explanations for the generated recommendations and gain further insights into user preferences. Full code for this work is available here: https://github.com/layer6ai-labs/TAFA.
Smart contract for electricity transactions and charge settlements using blockchain

Abstract In this article, aimed at the future “let go” electricity market, smart contracts for grid enterprises doing electricity transactions and charge settlements based on blockchain technology, as well as the trading model using the smart contracts, are proposed. Then the key technological difficulties are analyzed, and the solutions are given. The main goal of our research is to help developing the infrastructure for electricity market members, and match their bilateral trading. By running a smart contract instance in a peer‐to‐peer network composed by 4000 nodes, experiments show that the success rate is 99.38% and the average time consumption for each transaction is 16 seconds. If our method is applied, we can reduce the trust cost of the electric electricity market, and improve the efficiency of the electricity transaction and charge settlement.
PFAN++: Bi-Directional Image-Text Retrieval With Position Focused Attention Network

Bi-directional image-text retrieval and matching attract much attention recently. This cross-domain task demands a fine understanding of both modalities for learning a measure of different modality data. In this paper, we propose a novel position focused attention network to investigate the relation between the visual and the textual views. This work integrates the prior object position to enhance the visual-text joint-embedding learning. The image is first split into blocks, which are treated as the basic position cells, and the position of an image region is inferred. Then, we propose a position attention to model the relations between the image region and position cells. Finally, we generate a valuable position feature to further enhance the region expression and model a more reliable relationship between the visual image and the textual sentence. Experiments on the popular datasets Flickr30K and MS-COCO show the effectiveness of the proposed method. Besides the public datasets, we also conduct experiments on our collected practical large-scale news dataset (Tencent-News) to validate the practical application value of the proposed method. As far as we know, this is the first attempt to test the performance on the practical application. Our method achieves the competitive performance on all of these three datasets.
Model Size Reduction Using Frequency Based Double Hashing for Recommender Systems

Deep Neural Networks (DNNs) with sparse input features have been widely used in recommender systems in industry. These models have large memory requirements and need a huge amount of training data. The large model size usually entails a cost, in the range of millions of dollars, for storage and communication with the inference services. In this paper, we propose a hybrid hashing method to combine frequency hashing and double hashing techniques for model size reduction, without compromising performance. We evaluate the proposed models on two product surfaces. In both cases, experiment results demonstrated that we can reduce the model size by around 90 while keeping the performance on par with the original baselines.
Real-Time Mission-Motion Planner for Multi-UUVs Cooperative Work Using Tri-Level Programing

This article develops a novel mission-motion planner for unmanned underwater vehicles (UUVs) when dispatching them to visit a set of marine stations in a vast and time-varying environment. Specifically, a tri-level optimization model is built for the planner to finish the task with less energy cost. The lower-level is a motion planner, which provides safe and efficient paths with local environmental information. The middle-level is a mission planner, which designs a balanced station allocation mode as well as economical visitation sequences for each UUV concerning global information. The upper-level is a commander, which manages and synchronizes the two levels, so that UUVs can autonomously decide the next destination and corresponding paths in real-time. Thereafter, different heuristic algorithms are chosen according to each level property, and their initialization processes are modified to solve the optimization efficiently. Finally, the proposed model and algorithms present their outstanding performance in complex and large-scale cases.
A critical literature survey and prospects on tampering and anomaly detection in image data

Concernings related to image security have increased in the last years. One of the main reasons relies on the replacement of conventional photography to digital images, once the development of new technologies for image processing, as much as it has helped in the evolution of many new techniques in forensic studies, it also provided tools for image tampering. In this context, many companies and researchers devoted many efforts towards methods for detecting such tampered images, mostly aided by autonomous intelligent systems. Therefore, this work focuses on introducing a rigorous survey contemplating the state-of-the-art literature on computer-aided tampered image detection using machine learning techniques, as well as evolutionary computation, neural networks, fuzzy logic, Bayesian reasoning, among others. Besides, it also contemplates anomaly detection methods in the context of images due to the intrinsic relation between anomalies and tampering. Moreover, it aims at recent and in-depth researches relevant to the context of image tampering detection, performing a survey over more than 100 works related to the subject, spanning across different themes related to image tampering detection. Finally, a critical analysis is performed over this comprehensive compilation of literature, yielding some research opportunities and discussing some challenges in an attempt to align future efforts of the community with the niches and gaps remarked in this exciting field.
Supporting topic modeling and trends analysis in biomedical literature

Topic modeling refers to a suite of probabilistic algorithms for extracting popular topics from a collection of documents. A common approach involves the use of the Latent Dirichlet Allocation (LDA) algorithm, and, although free implementations are available, their deployment in general requires a certain degree of programming expertise. This paper presents a user-friendly web-based application, specifically designed for the biomedical professional, that supports the entire process of topic modeling and comparative trends analysis of scientific literature. The application was evaluated for its efficacy and usability by intended users with no programming expertise (15 biomedical professionals). Results of evaluation showed a positive acceptance of system functionalities and an overall usability score of 76/100 in the System Usability Score (SUS) scale. This suggests that literature topic modeling can become more popular amongst biomedical professionals via the use of a user-friendly application that fully supports the entire workflow, thus opening new perspectives for literature review and scientific research.
”And then they died”: Using Action Sequences for Data Driven, Context Aware Gameplay Analysis

Many successful games rely heavily on data analytics to understand players and inform design. Popular methodologies focus on machine learning and statistical analysis of aggregated data. While effective in extracting information regarding player action, much of the context regarding when and how those actions occurred is lost. Qualitative methods allow researchers to examine context and derive meaningful explanations about the goals and motivations behind player behavior, but are difficult to scale. In this paper, we build on previous work by combining two existing methodologies: Interactive Behavior Analytics (IBA) [2] and sequence analysis (SA), in order to create a novel, mixed methods, human-in-the-loop data analysis methodology that uses behavioral labels and visualizations to allow analysts to examine player behavior in a way that is context sensitive, scalable, and generalizable. We present the methodology along with a case study demonstrating how it can be used to analyze behavioral patterns of teamwork in the popular multiplayer game Defense of the Ancients 2 (DotA 2).
The JPEG Pleno Light Field Coding Standard 4D-Transform Mode: How to Design an Efficient 4D-Native Codec

The increasing demand for highly realistic and immersive visual experiences has led to the emergence of richer 3D visual representation models such as light fields, point clouds and meshes. Light fields may be modelled as a 2D array of 2D views, corresponding to a large amount of data, which demands for highly efficient coding solutions. Although static light fields are inherently 4D structures, the coding solutions in the literature mostly employ traditional 2D coding tools associated with techniques such as depth-based image rendering to generate a residual, again to be coded using available 2D coding tools. To address the market needs, JPEG has launched the so-called JPEG Pleno standard, which Part 2 is dedicated to light field coding. The JPEG Pleno Light Field Coding standard includes two coding modes, one based on the 4D-DCT, so-called 4D-Transform mode, and another based on depth-based synthesis, so-called 4D-Prediction. The 4D-Transform coding mode standardizes for the first time a 4D-native light field coding solution where the full light field redundancy across the four dimensions is comprehensively exploited, somehow extending to 4D the 2D coding framework adopted decades ago by the popular JPEG Baseline standard. In this context, this paper describes and analyzes in detail the conceptual and algorithmic design process which has led to the creation of the JPEG Pleno Light Field Coding standard 4D-Transform coding mode. This has happened through a sequence of steps involving technical innovation design and integration where increasingly sophisticated coding tools have been combined and improved to maximize the final rate distortion (RD) performance.
Estonian Case Inflection Made Simple

According to word and paradigm morphology (Matthews 1974, Blevins 2016), the word is the basic cognitive unit over which paradigmatic analogy operates to predict form and meaning of novel forms. Baayen et al. (2019b, 2018) introduced a computational formalization of word and paradigm morphology which makes it possible to model the production and comprehension of complex words without requiring exponents, morphemes, inflectional classes, and separate treatment of regular and irregular morphology. This computational model, Linear Discriminative Learning (LDL), makes use of simple matrix algebra to move from words’ forms to meanings (comprehension) and from words’ meanings to their forms (production). In Baayen et al. (2018), we showed that LDL makes accurate predictions for Latin verb conjugations. The present study reports results for noun declension in Estonian. Consistent with previous findings, the model’s predictions for comprehension and production are highly accurate. Importantly, the model achieves this high accuracy without being informed about stems, exponents, and inflectional classes. The speech errors produced by the model look like errors that native speakers might make. When the model is trained on incomplete paradigms, comprehension accuracy for unseen forms is hardly affected, but production accuracy decreases, reflecting the well-known asymmetry between comprehension and production.
QShield: Protecting Outsourced Cloud Data Queries With Multi-User Access Control Based on SGX

Due to the concern on cloud security, digital encryption is applied before outsourcing data to the cloud for utilization. This introduces a challenge about how to efficiently perform queries over ciphertexts. Crypto-based solutions currently suffer from limited operation support, high computational complexity, weak generality, and poor verifiability. An alternative method that utilizes hardware-assisted Trusted Execution Environment (TEE), i.e., Intel SGX, has emerged to offer high computational efficiency, generality and flexibility. However, SGX-based solutions lack support on multi-user query control and suffer from security compromises caused by untrustworthy TEE function invocation, e.g., key revocation failure, incorrect query results, and sensitive information leakage. In this article, we leverage SGX and propose a secure and efficient SQL-style query framework named QShield. Notably, we propose a novel lightweight secret sharing scheme in QShield to enable multi-user query control; it effectively circumvents key revocation and avoids cumbersome remote attestation for authentication. We further embed a trust-proof mechanism into QShield to guarantee the trustworthiness of TEE function invocation; it ensures the correctness of query results and alleviates side-channel attacks. Through formal security analysis, proof-of-concept implementation and performance evaluation, we show that QShield can securely query over outsourced data with high efficiency and scalable multi-user support.
An algorithm based on bidirectional searching and geometric constrained sampling for automatic manipulation planning in aircraft cable assembly

Robotic manipulation of deformable linear objects has potential application in aircraft cable assembly. However, it is difficult to be implemented in real tasks due to requiring prediction of the object’s deformation and obstacle-free manipulation planning with high efficiency. Aiming at exploring automatic assembly planning for aircraft cables assembly in narrow cabins with obstacles, this paper proposes a novel planning algorithm named RRT-BwC (Bi-direction with Constrain). Firstly, formulation of the question and the manipulation objects are presented with geometric definitions. Then a bi-RRT-tree searching method is developed to design the planner for overcoming obstacles in the high dimensional planning space. The numerical distance between configurations in the cable shape space are defined to measure the demands for their transition in consideration of the manipulation logics. And the sampling zone constrains to the shape configuration nodes are also discussed. Finally, the algorithm presents a valid manipulation sequence for robotic manipulation. The functionality and performance of the improved RRT approach are demonstrated with a simulated real-world problem of aircraft cable assembly, exhibiting computation efficiency promotion.
NGUARD+

Game bots are automated programs that assist cheating users, leading to an imbalance in the game ecosystem and the collapse of user interest. Online games provide immersive gaming experience and attract many loyal fans. However, game bots have proliferated in volume and method, evolving with the real-world detection methods and showing strong diversity, leaving game bot detection efforts extremely difficult. Existing game bot detection techniques mostly rely on handcrafted features or time-series based features instead of fully utilizing player behavior sequences. In this regard, a more reasonable way should be learning user patterns from player behavior sequences when facing the fast-changing nature of game bots. Here we propose a general game bot detection framework for massively multiplayer online role playing games termed NGUARD+ (denoting NetEase Games’ Guard), which captures user patterns in order to identify game bots from player behavior sequences. NGUARD+ mainly employs attention-based methods to automatically differentiate game bots from humans. We provide a combination of supervised and unsupervised methods for game bot detection to detect game bots and new type of game bots even when the labels of game bots are limited. Specifically, we propose the following two variants for attention-based sequence modeling: Attention based Bidirectional Long Short-Term Memory Networks (ABLSTM) and Hierarchical Self-Attention Network (HSAN) as our supervised models. ABLSTM is keen on inducing certain inductive biases which makes learning more reasonable as well as capturing local dependency and global information, while HSAN could handle much longer behavior sequences with less memory and higher computational efficiency. Experiments conducted on a real-world dataset show that NGUARD+ can achieve remarkable performance improvement compared to traditional methods. Moreover, NGUARD+ can reveal outstanding robustness for game bots in mutated patterns and even in completely unseen patterns.
Energy-Efficient Path Planning Algorithm on Three-Dimensional Large-Scale Terrain Maps for Mobile Robots

This paper presents an algorithm for energy-efficient path planning for robotic systems in three-dimensional maps, called Local Roughness Local Height Difference A* (LRLHD-A*). This algorithm is an extension of A* algorithm; it uses local irregularities of the surface and local height differences to reveal static obstacles, as well as a metric for edge weight determination. Approbation of this algorithm in the Gazebo simulation environment revealed that the distance between the start and target points has no substantial effect on the duration of planning process, using this algorithm. Experimental comparison of performance efficiency of the actual algorithm with relevant alternatives showed, that the LRLHD-A* algorithm traces paths 4–15 times faster, than the most successful analogous algorithm LRLHD-Dijkstra. The path, established at output of our algorithm, outperforms similar algorithms from the A* group in energy efficiency by 1.3–6.3%. This is because the LRLHD-A* algorithm not only ensures finding of the shortest path to the target point, but also accounts for energy consumption of the robot on the route, based on the terrain features and specificity of motion within it.