教学课程资源库 更多>>

关键词： Skeleton   Planning   Robots   Approximation algorithms   Reliability   Probabilistic logic   Heuristic algorithms   Computer science   Topology   Three-dimensional displays   Motion planning   path planning   computational geometry  

摘要： We present a hierarchical RRT-based motion planning strategy, Hierarchical Annotated-Skeleton Guided RRT (HAS-RRT), guided by a workspace skeleton, to solve motion planning problems. HAS-RRT provides up to a 91% runtime reduction and builds a tree at least 30% smaller than competitors while still finding competitive-cost paths. This is because our strategy prioritizes paths indicated by the workspace guidance to efficiently find a valid motion plan for the robot. Existing methods either rely too heavily on workspace guidance or have difficulty finding narrow passages. By taking advantage of the assumptions that the workspace skeleton provides, HAS-RRT is able to build a smaller tree and find a path faster than its competitors. Additionally, we show that HAS-RRT is robust to the quality of workspace guidance provided and that, in a worst-case scenario where the workspace skeleton provides no additional insight, our method performs comparably to an unguided method.

关键词： Indexes   Blockchains   Mathematical models   Memory   Location awareness   Knowledge engineering   Data engineering   Computer science   Trustless services   Query processing   Blockchain query   index management   dynamic workloads   index benefit   verification  

摘要： Blockchain-based query with its traceability and data provenance has become increasingly popular and widely adopted in numerous applications. Yet existing index-based query approaches are only efficient under static blockchain query workloads where the query attribute or type must be fixed. It turns out to be particularly challenging to construct an efficient index for dynamic workloads due to prohibitively long construction time and excessive storage consumption. In this paper, we present FlexIM, the first efficient and verifiable index management system for blockchain dynamic queries. The key innovation in FlexIM is to uncover the inherent characteristics of blockchain, i.e., data distribution and block access frequency, and then to optimally choose the index by utilizing reinforcement learning technique under varying workloads. In addition, we enhance and facilitate verifiability with low storage overhead by leveraging Root Merkle Tree (RMT) and Bloom Filter Merkle Tree (BMT). Our comprehensive evaluations demonstrate that FlexIM outperforms the state-of-the-art blockchain query mechanism, vChain+, by achieving a 26.5% speedup while consuming 94.2% less storage, on average, over real-world Bitcoin datasets.

关键词： Multiplexing   Recommender systems   Graph neural networks   Correlation   Contrastive learning   Representation learning   Electronic commerce   Bipartite graph   Training   Computer science   Recommender system   graph representation learning   multiplex graph neural network   behavior pattern   relation chain  

摘要： Effective recommender systems play a crucial role in accurately capturing user and item attributes that mirror individual preferences. Some existing recommendation techniques have started to shift their focus towards modeling various types of interactive relations between users and items in real-world recommendation scenarios, such as clicks, marking favorites, and purchases on online shopping platforms. Nevertheless, these approaches still grapple with two significant challenges: (1) Insufficient modeling and exploitation of the impact of various behavior patterns formed by multiplex relations between users and items on representation learning, and (2) ignoring the effect of different relations within behavior patterns on the target relation in recommender system scenarios. In this work, we introduce a novel recommendation framework, Dual-Channel Multiplex Graph Neural Network (DCMGNN), which addresses the aforementioned challenges. It incorporates an explicit behavior pattern representation learner to capture the behavior patterns composed of multiplex user-item interactive relations, and includes a relation chain representation learner and a relation chain-aware encoder to discover the impact of various auxiliary relations on the target relation, the dependencies between different relations, and mine the appropriate order of relations in a behavior pattern. Extensive experiments on three real-world datasets demonstrate that our DCMGNN surpasses various state-of-the-art recommendation methods. It outperforms the best baselines by 10.06% and 12.15% on average across all datasets in terms of Recall@10 and NDCG@10 respectively. The source code of our paper is available at https://***/lx970414/TKDE-DCMGNN.

摘要： Black beer festivals in the United States are dynamic sites where geography, culture, and economy converge to challenge exclusion and reimagine representation in the craft beer industry. This paper explores how these festivals operate as culturally significant and economically generative spaces that reframe the dominant narrative of craft beer as a white, male-dominated field. Drawing on concepts of cultural capital, tourism geography, and urban economic development, the paper positions Black beer festivals as platforms for reclaiming brewing heritage, fostering community, and advancing racial equity within cultural economies. Beginning with a historical overview of Black American brewing traditions and their suppression through colonialism, Prohibition, and systemic racism, the paper traces a lineage of cultural erasure and resistance that informs the present-day significance of festivals like Blacktoberfest in Atlanta. Through this case study, the analysis reveals how Blacktoberfest embodies localized place-making and global cultural expression, serving both as a space of celebration and as a catalyst for economic participation and social inclusion. Ultimately, the paper argues that Black beer festivals are not merely leisure events but geographies of empowerment, where the cultural, spatial, and economic dimensions of Black life are made visible, valued, and central to rethinking the contours of American craft beer culture.

关键词： Computer security   Security   Reliability   Computer crime   Economics   Technological innovation   Protocols   Surveys   Computer science   Stability criteria  

摘要： This study investigates cybersecurity compliance in Sierra Leone's public sector, exploring factors like self-efficacy, innovativeness, perceived security, trust, and cybersecurity awareness. The research uses structural equation modeling to analyze survey data from four hundred and ninety-two (492) public sector employees from five ministries and one agency. Reliable measurement models confirm these constructs' validity. Analysis shows that self-efficacy and innovativeness positively impact cybersecurity compliance, with perceived trust mediating these relationships. However, perceived security's mediating role is less significant. Cybersecurity awareness notably moderates these relationships, enhancing compliance intention. The study offers significant insights for enhancing cybersecurity strategies, particularly in developing countries, and underscores the importance of individual factors in cybersecurity compliance.

关键词： Multidimensional dynamic assessment   Zone of proximal development   Competence in computer science   Learning potential  

摘要： Computer Science (CS) is a vital subject in K-12 education, and acquiring proficiency in CS is essential for nurturing talent. However, current teaching practices often rely on standardized tests to evaluate academic performance, which may not offer a comprehensive and multidimensional assessment of students' competency in learning CS. Furthermore, developing students' competence is a dynamic and non-linear process. Therefore, it is essential to develop alternative assessment methods to evaluate students' competency and learning potential in CS comprehensively. This study presents a computational model of the Zone of Proximal Development (ZPD) based on dynamic evaluation and the fuzzy evaluation method, and develops a multidimensional dynamic assessment system to measure the developmental intervals and cognitive states of learners' different dimensions of competence in CS. A quasi-experimental study was conducted to evaluate the effectiveness of the system in a high school (K12) computer science course related to the teaching of programming. The experimental group comprised 50 students who received instruction with the assessment system, while the control group, consisting of 52 students, received traditional teaching methods. The study demonstrates that the multidimensional dynamic assessment system had a significant positive impact on students' competence in CS, particularly in the dimensions of "learning" and "applying". Furthermore, the results indicate students' academic achievement and learning potential improvements.

关键词： Digital agriculture   Abstraction   Critical agri-food studies   Networking research   Infrastructure   Responsible research and innovation   Knowledge convergence   Vendor lock-in  

摘要： Excitement about digital agriculture-i.e., expanded reliance on collecting, integrating, analyzing, and applying digital data in agri-food systems-is bringing two different conceptualizations of abstraction into collision and dialogue. Critical agri-food scholars have long expressed concerns about disembedding-or abstracting-agriculture from particular geographies, farmers' varied interests, and ecological processes. In contrast, in computer science, abstraction is understood as beneficial for taming the complexities of technology and supporting the development of general-purpose tools. In this paper, we compare these very different theorizations of abstraction through an ethnographic case study of the early development of new digital agriculture networking infrastructure. We analyze how the commitments to abstraction in computer science relate to and depart from critical agri-food studies' critiques of decontextualization and disembedding. The study is based on a long-term collaboration between computer networking researchers and social scientists. Our findings indicate that the commitment to abstraction by computer network scientists leads them to engage minimally with critical agri-food studies' concerns regarding historical processes of agricultural industrialization and their effect on farm size, the labor process, and the environment, but produces deep engagement with concerns regarding corporate control of innovation trajectories. We find, however, that the technologists focus on open innovation and vendor lock-in in order to expand the scale, scope, and pace of innovation, rather than to advance social justice and environmental sustainability, demonstrating that openness can be understood and practiced in various ways. Through integrated treatment of abstraction in computer science and critical agri-food studies, this article highlights opportunities and constraints for interdisciplinary analysis pertaining to the development of digital agriculture. Through

关键词： Vectors   Roads   Nickel   Matrix decomposition   Data mining   Costs   Social networking (online)   Linear programming   Computer science   Training   Multi-attributed road-social networks   multi-attributed community   local community detection   dominance relation  

摘要： The information available in multi-attributed road-social networks includes network structure, location information, and numerical attributes. Most studies mainly focus on mining communities by combining structure with attributes or structure with location, which do not consider structure, attributes, and location simultaneously. Therefore, we propose a parameter-free algorithm, called LCDMRS, to mine local communities in multi-attributed road-social networks. LCDMRS extracts a sub-network surrounding the given node and embeds it to generate the vector representations of nodes, which incorporates both structural and attributed information. Based on the vector representations of nodes, the average cosine similarity between nodes is designed to ensure both the structural and attributed cohesiveness of the community, while the community node density is designed to ensure the spatial cohesiveness of the community. Targeting the community node density and cosine similarity of nodes, LCDMRS takes the given node as the starting node and employs the community dominance relation to expand the community outward. Experimental results on multiple real-world datasets demonstrate LCDMRS outperforms comparison algorithms.

关键词： Industrial Internet of Things   Collaboration   Consensus protocol   Security   Protocols   Relays   Throughput   Safety   Informatics   Computer science   Blockchain   consensus   cross-chain communication  

摘要： Blockchain-based industrial Internet-of-Things (IIoT) systems have seen rapid adoption and development in recent years. The increasing diversity of IIoT application scenarios is driving the growth of multichain ecosystem, making cross-chain communication a key issue in multichain collaboration. However, existing centralized cross-chain architectures risk derailing the blockchain's trust-free decentralization and suffer from single point failure. The design of decentralized cross-chain collaboration mainly faces two key challenges. First, implicit cross-chain accountability, which is caused by collusion among malicious distributed participants and, thus, compromises cross-chain security. Second, low cross-chain efficiency, which is induced by the highly dynamic environment in practical cross-chain networks, i.e., changing memberships, and adaptive attacks to corrupt honest nodes. In this article, we propose a cross-chain consensus protocol DeCross to solve the abovementioned problems. DeCross achieves decentralized cross-chain collaboration with explicit accountability and high efficiency. Specifically, we audit participants with a succinct auditable data object constructed from the protocol to hold nodes accountable for misbehaving. Furthermore, we propose a parallel processing workflow that leverages both CPUs and GPUs to guarantee efficient and stable cross-chain communication. Finally, we implement a prototype based on the hyperledger fabric with both local and geo-distributed clusters. Our extensive experiments show that DeCross achieves 44% better throughput over the existing cross-chain approaches.

关键词： Balinese Traditional Architecture   Balinese Traditional Buildings   Kosala Kosali   Balinese Traditional Architecture Dataset   Residential Buildings   Sacred Buildings   Cultural Preservation   Computer Vision and Pattern Recognition   Computer science  

摘要： This study introduces a dataset focused on Balinese traditional architecture, comprising two main categories, residential and sacred buildings. The dataset includes 14 types of residential buildings with 68 images and 29 types of sacred buildings with 76 images. Each design is represented through 2D drawings, such as front, side, section views, and floor plans, created using AutoCAD software. These drawings are meticulously derived from traditional Balinese architectural texts to ensure alignment with cultural norms. The completed designs were exported into JPG format using Figma, with accompanying metadata that includes size and structural details to enhance usability. This dataset aims to support researchers, cultural preservationists, and educators in exploring and preserving Balinese architectural heritage. (c) 2025 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY-NC license ( http://***/licenses/by-nc/4.0/ )