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关键词： Mirrors   Visualization   Feature extraction   Computer science   Object detection   Task analysis   Image edge detection   Mirror detection   visual chirality   intrinsic mirror property   salient object detection  

摘要： Mirror detection is challenging because the visual appearances of mirrors change depending on those of their surroundings. As existing mirror detection methods are mainly based on extracting contextual contrast and relational similarity between mirror and non-mirror regions, they may fail to identify a mirror region if these assumptions are violated. Inspired by a recent study of applying a CNN to help distinguish whether an image is flipped or not based on the visual chirality property, in this paper, we rethink this image-level visual chirality property and reformulate it as a learnable pixel level cue for mirror detection. Specifically, we first propose a novel flipping-convolution-flipping (FCF) transformation to model visual chirality as learnable commutative residual. We then propose a novel visual chirality embedding (VCE) module to exploit this commutative residual in multi-scale feature maps, to embed the visual chirality features into our mirror detection model. Besides, we also propose a visual chirality-guided edge detection (CED) module to integrate the visual chirality features with contextual features for detection refinement. Extensive experiments show that the proposed method outperforms state-of-the-art methods on three benchmark datasets.

关键词： Periodic structures   Task analysis   Computer science   Network topology   Data models   Topology   Prediction algorithms   Network representation learning   network embedding   attributed network   hierarchical attributed network   granulation  

摘要： Network representation learning, also called network embedding, aiming to learn low dimensional vectors for nodes while preserving essential properties of the network, benefits plenty of practical applications. However, how to do representation learning on the network quickly and effectively is a meaningful and challenging task, especially for the attributed networks. In this paper, we propose HANE, a Hierarchical Attributed Network Embedding framework, which is a fast and effective method by quickly constructing a hierarchical attributed network of different granularities to learn nodes representations. Specifically, for an attributed network, HANE first builds a hierarchy of successively smaller attributed network from fine to coarse by the fast granulation strategy fusing topological structure and node attributes. After using any unsupervised network embedding method to learn nodes representations of the coarsest network, HANE refines the nodes representations of the hierarchical attributed network from coarse to fine. HANE improves the speed of network representation learning while maintaining its performance and the representation learning method of the coarsest network is flexible. We conduct extensive evaluations for the proposed framework HANE on six datasets and two benchmark applications. Experimental results demonstrate that HANE achieves significant improvements over previous state-of-the-art network embedding methods in efficiency and effectiveness.

关键词： Ciphers   Encryption   Security   Sun   Technological innovation   Iterative methods   Computer science   Feistel structure   Lai-Massey structure   impossible differential   dual structure   zero-correlation linear hull  

摘要： This paper mainly investigates the iterative structures whose decryption is similar to the encryption. Firstly, we unify many well-known structures which share similar procedures between the decryption and the encryption, and give a sufficient and necessary condition for this structure to be bijective, which reveals many new insights into the Feistel structure as well as the Lai-Massey structure. Secondly, we analyze the security of the unified structure against the known cryptanalysis. By extending the dual structure from a Feistel structure to the unified structure, we prove that a differential of the unified structure is impossible if and only if it is a zero-correlation linear hull of its dual structure, which presents a generalized link between the impossible differential and zero-correlation linear cryptanalysis shown in CRYPTO 2015. Significantly, several constraints on the linear components of the cipher and the permutation on the branches of the cipher are specified to make the structure resilient to differential and linear cryptanalysis. Furthermore, in the case that the order of the permutation equals the number of the branches n, we prove that there always exist a (3n-1)-round impossible differential and a (3n-1)-round zero-correlation linear hull of the structure, and also present an algorithm to construct these distinguishers. Finally, we propose some novel structures which might be used in future block cipher designs.

关键词： Industries   Computer science   Conferences   Europe   Computer graphics   History   Standards  

摘要： "The Origins of Computer Graphics in Europe," is being published in two parts: Part 1, in this issue of IEEE Computer Graphics and Applications, is subtitled "The Beginnings in Germany";Part 2, to be published in the May/June issue, is subtitled "The Spreading of Computer Graphics in Europe." I was a participant, contributor, and witness to the events reported here and I relate my personal story along with the broader history. Part 1 describes the origins and successful evolution of computer graphics in Germany, starting in 1965, and includes details of the people and subject matter of the earliest research groups. It describes the efforts undertaken to establish computer graphics as a proper academic discipline, including the founding of EUROGRAPHICS, and creation of institutes for both basic and applied research in computer graphics. Part 2 continues the story with a focus on activities contributing to the growth of the academic and industrial computer graphics communities across Europe and documents the two IFIP workshops at Seillac and the development of the GKS Graphics Standard. Over these years, computer graphics gained respect and importance as a component of the computer science curricula and became an important tool and enabling technology for applications for industry and for the IT market in Europe.

关键词： Dictionaries   Visualization   Logic gates   Physics   Biology   Ontologies   Computer science  

摘要： Effective communication is vital for academic project success, particularly in multidisciplinary teams with diverse backgrounds and disciplines. Misunderstandings can arise from differing interpretations of terms, which may go unnoticed. VisDict aims to bridge this gap by creating a visual dictionary within a science gateway to facilitate clear communication between workflow providers and domain researchers. This innovative approach translates computational science concepts into fields like physics and biology. This article delves into our method for building the visual dictionary, the insights gained from curating initial entries, and future plans for automated expansion and illustration of relevant terms.

关键词： Controllability   Heuristic algorithms   Approximation algorithms   Laplace equations   Computer science   Greedy algorithms   Dynamic programming   graph algorithms   network topology   strong structural controllability  

摘要： In this article, we study the problem of computing a tight lower bound on the dimension of the strong structurally controllable subspace (SSCS) in networks with Laplacian dynamics. The bound is based on a sequence of vectors containing the distances between leaders (nodes with external inputs) and followers (remaining nodes) in the underlying network graph. Such vectors are referred to as the distance-to-leaders vectors. We give exact and approximate algorithms to compute the longest sequences of distance-to-leaders vectors, which directly provide distance-based bounds on the dimension of SSCS. The distance-based bound is known to outperform the other known bounds (for instance, based on zero-forcing sets), especially when the network is partially strong structurally controllable. Using these results, we discuss an application of the distance-based bound in solving the leader selection problem for strong structural controllability. Further, we characterize strong structural controllability in path and cycle graphs with a given set of leader nodes using sequences of distance-to-leaders vectors. Finally, we numerically evaluate our results on various graphs.

关键词： History   Feature extraction   Wireless fidelity   Social networking (online)   Systematics   Peer-to-peer computing   Computer science   Fraud-agents detection   online lending   Index Terms   empirical study  

摘要： Online Microlending, a new financial service, focuses on small loans without any sort of collateral. It provides more flexible and quicker funding for borrowers, as well as higher interest rates of return. For platforms that provide such services, an essential task is to adequately evaluate each loan's risk so as to minimize the possible financial loss. However, there exists a special group of borrowers, namely fraud-agents, who gain illegal profits from inciting other borrowers to cheat, i.e., they help the high-risk borrowers evade the risk evaluation by crafting fake personal information. The existence of fraud-agents poses a severe threat to the risk management systems and results in a huge financial loss for lending platforms. In this article, we present the first machine learning-based solution to detect fraud-agents in online microlending. The key challenge of this decade-long problem is that it is unclear how to construct effective features from multiple behavior logs such as phone call history, address book, loan history and activity logs of borrowers. To address this problem, we first conduct an empirical study on over 600K borrowers to gain some insights on the adversarial behaviors of fraud-agents comparing to normal borrowers and benign-agents. Based on the study, we are able to design a total of 26 features, falling into four groups, for fraud agent detection. Then, we propose a two-stage detection model to address the challenge of limited number of labeled fraud agent examples. The evaluation results show that our method can achieve a precision of 94.30%. We deploy our method on a real large online microlending platform with 11,953,273 borrowers, and we identify 29,727 fraud-agents from them. The domain experts from the platform confirm that 95.59% of them are real fraud-agents, and have added them to the platform's internal blacklist. We further conduct a measurement study on those fraud-agents to share deeper insights on their adversarial behaviors.

关键词： COVID-19   CAPE framework   Capacity   Access   Participation   Experience   underrepresented   underserved   historically marginalized  

摘要： Research Problem. Computer science (CS) education researchers conducting studies that target high school students have likely seen their studies impacted by COVID-19. Interpreting research findings impacted by COVID-19 presents unique challenges that will require a deeper understanding as to how the pandemic has affected underserved and underrepresented students studying or unable to study computing. Research Question. Our research question for this study was: In what ways has the high school computer science educational ecosystem for students been impacted by COVID-19, particularly when comparing schools based on relative socioeconomic status of a majority of students? Methodology. We used an exploratory sequential mixed methods study to understand the types of impacts high school CS educators have seen in their practice over the past year using the CAPE theoretical dissaggregation framework to measure schools' Capacity to offer CS, student Access to CS education, student Participation in CS, and Experiences of students taking CS. Data Collection Procedure. We developed an instrument to collect qualitative data from open-ended questions, then collected data from CS high school educators (n = 21) and coded them across CAPE. We used the codes to create a quantitative instrument. We collected data from a wider set of CS high school educators (n = 185), analyzed the data, and considered how these findings shape research conducted over the last year. Findings. Overall, practitioner perspectives revealed that capacity for CS Funding, Policy & Curriculum in both types of schools grew during the pandemic, while the capacity to offer physical and human resources decreased. While access to extracurricular activities decreased, there was still a significant increase in the number of CS courses offered. Fewer girls took CS courses and attendance decreased. Student learning and engagement in CS courses were significantly impacted, while other noncognitive factors like interest

关键词： Computer science   Databases   Indexing  

摘要： DBLP provides comprehensive and free computer science (CS) bibliographic data to all. But how well does it really cover CS journals? In this article, we compare DBLP's indexed journals with those classified as CS by the leading indexing services today-Web of Science and Scopus.