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Smoothness preserving layout for dynamic labels by hybrid optimization

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Computational Visual Media 2022年第1期8卷 149-163页

作者： Yu He Guo-Dong Zhao Song-Hai Zhang department of computer Science and technology Tsinghua UniversityBeijingChina department of computer Science and technology Tianjin University of TechnologyTianjinChina

Stable label movement and smooth label trajectory are critical for effective information *** label changes cannot be avoided by whatever forced directed methods due to the unreliability of resultant force or global optimization methods due to the complex trade-off on the different *** solve this problem,we proposed a hybrid optimization method by taking advantages of the merits of both *** first detect the spatial-temporal intersection regions from whole trajectories of the features,and initialize the layout by optimization in decreasing order by the number of the involved *** label movements between the spatial-temporal intersection regions are determined by force directed *** cope with some features with high speed relative to neighbors,we introduced a force from future,called temporal force,so that the labels of related features can elude ahead of time and retain smooth *** also proposed a strategy by optimizing the label layout to predict the trajectories of features so that such global optimization method can be applied to streaming data.

关键词： label layout smoothness preserving dynamic label forced based static optimization hybrid optimization

Machine Learning Techniques in Predicting Hot Deformation Behavior of Metallic Materials

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computer Modeling in Engineering & Sciences 2025年第1期142卷 713-732页

作者： Petr Opela Josef Walek Jaromír Kopecek department of Metallurgical Technologies Faculty of Materials Science and TechnologyVSB–Technical University of OstravaOstrava70800Czech Republic FZU—Institute of Physics of the Czech Academy of Sciences Prague18200Czech Republic

In engineering practice,it is often necessary to determine functional relationships between dependent and independent *** relationships can be highly nonlinear,and classical regression approaches cannot always provide sufficiently reliable ***,Machine Learning(ML)techniques,which offer advanced regression tools to address complicated engineering issues,have been developed and widely *** study investigates the selected ML techniques to evaluate their suitability for application in the hot deformation behavior of metallic *** ML-based regression methods of Artificial Neural Networks(ANNs),Support Vector Machine(SVM),Decision Tree Regression(DTR),and Gaussian Process Regression(GPR)are applied to mathematically describe hot flow stress curve datasets acquired experimentally for a medium-carbon *** the GPR method has not been used for such a regression task before,the results showed that its performance is the most favorable and practically unrivaled;neither the ANN method nor the other studied ML techniques provide such precise results of the solved regression analysis.

关键词： Machine learning Gaussian process regression artificial neural networks support vector machine hot deformation behavior

A Combinational Perspective in Stimulating Cooperation in Mobile Ad Hoc Networks

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Journal of computer Science & technology 2011年第2期26卷 256-268页

作者： Mahshid Rahnamay-Naeini Masoud Sabaei department of computer Engineering and Information technology Amirkabir University of Technology department of Electrical and computer Engineering University of New Mexico

In wireless ad hoc networks cooperation among nodes cannot always be assumed since nodes with limited resources and different owners are capable of making independent decisions. Cooperation problems in topology control and packet forwarding tasks have been mostly studied separately but these two tasks are not independent. Considering a joint cooperation problem by taking into account dependencies between tasks will result in more reliable and efficient networks. In this paper topology control definition is extended to cover cooperation problem in both packet forwarding and topology control in a single problem. In this definition nodes have to adjust their transmission power and decide on their relay role. This paper models the interactions of nodes as a potential game with two-dimensional utility function. The presented model, named TCFORCE （Topology Control packet FORwarding Cooperation Enforcement）, preserves the network connectivity and reduces the energy consumption by providing cooperative paths between all pairs of nodes in the network.

关键词： game theory non-cooperative packet forwarding topology control wireless ad hoc networks

KeJia:towards an autonomous service robot with tolerance of unexpected environmental changes

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Frontiers of Information technology & Electronic Engineering 2019年第3期20卷 307-317页

作者： Wei SHUAI Xiao-ping CHEN department of computer Science and technology University of Science and Technology of China

KeJia is a domestic service robot, consisting of a mobile base, an arm, two cameras, and a set of software components for perception, manipulation, natural language understanding, motion and task planning, and decision making. With on-line running of these functions, a robot can adapt to dynamic environments which may have unexpected changes. In this paper, we propose a novel hierarchical method which combines motion planning with a neural network, so that the robot can tolerate errors from sensors, wear of parts, and human disturbances during motion execution. We evaluate our work on KeJia that cooks popcorn using a microwave oven, where humans try to disturb KeJia during the operation.

关键词： Robot Task planning Manipulation

PPLS: a privacy-preserving location-sharing scheme in mobile online social networks

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Science China(Information Sciences) 2020年第3期63卷 173-183页

作者： Chang XU Xuan XIE Liehuang ZHU Kashif SHARIF Chuan ZHANG Xiaojiang DU Mohsen GUIZANI School of computer Science and technology Beijing Institute of Technology department of computer and Information Sciences Temple University department of computer Science and Engineering Qatar University

The recent proliferation of mobile devices has given rise to mobile online social networks(m OSNs), an emerging network paradigm that uses social networks as its main design element. As one of the most critical components in m OSNs, location sharing plays an important role in helping users share information and strengthen their social bonds, which however may compromise users’ privacy, including location information and social relationship details. To address these challenges, some solutions have been proposed. However, none of them considers the privacy of inter-user threshold distance, which effectively can be used to identify users, their friends, and location information, by malicious or undesired elements of the system. To overcome this limitation, we propose a secure distance comparison protocol. Furthermore,we present a privacy-preserving location-sharing scheme(PPLS), which allows users to build more complex access control policies. The safety of our scheme is validated by the security analysis and the experimental results demonstrate the efficiency of PPLS scheme.

关键词： privacy-preservation location-sharing mobile online social networks

Garbage Collector Verification for Proof-Carrying Code

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Journal of computer Science & technology 2007年第3期22卷 426-437页

作者：林春晓陈意云李隆华蓓 department of computer Science and technology University of Science and technology of China

We present the verification of the machine-level implementation of a conservative variant of the standard mark-sweep garbage collector in a Hoare-style program logic. The specification of the collector is given on a machine-level memory model using separation logic, and is strong enough to preserve the safety property of any common mutator program. Our verification is fully implemented in the Coq proof assistant and can be packed immediately as foundational proof-carrying code package. Our work makes important attempt toward building fully certified production-quality garbage collectors.

关键词： program verification garbage collector proof-carrying code program safety

Double Barrier Coverage in Dense Sensor Networks

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Journal of computer Science & technology 2008年第1期23卷 154-164,F0003页

作者：蒋承东陈国良 department of computer Science and technology University of Science and Technology of China

When a sensor network is deployed to detect objects penetrating a protected region, it is not necessary to have every point in the deployment region covered by a sensor. It is enough if the penetrating objects are detected at some point in their trajectory. If a sensor network guarantees that every penetrating object will be detected by two distinct sensors at the same time somewhere in this area, we say that the network provides double barrier coverage （DBC）. In this paper, we propose a new planar structure of Sparse Delaunay Triangulation （SparseDT）, and prove some elaborate attributes of it. We develop theoretical foundations for double barrier coverage, and propose efficient algorithms with NS2 simulator using which one can activate the necessary sensors to guarantee double barrier coverage while the other sensors go to sleep. The upper and lower bounds of number of active nodes are determined, and we show that high-speed target will be detected efficiently with this configuration.

关键词： wireless sensor network barrier coverage Delaunay triangulation distributed algorithm

Integrating Evolutionary Testing with Reinforcement Learning for Automated Test Generation of Object-Oriented Software

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Chinese Journal of Electronics 2015年第1期24卷 38-45页

作者： HE Wei ZHAO Ruilian ZHU Qunxiong department of computer Science and technology Beijing University of Chemical Technology

Recent advances in evolutionary test generation greatly facilitate the testing of Object-oriented(OO) software. Existing test generation approaches are still limited when the Software under test(SUT) includes Inherited class hierarchies(ICH) and Non-public methods(NPM). This paper presents an approach to generate test cases for OO software via integrating evolutionary testing with reinforcement learning. For OO software with ICH and NPM, two kinds of particular isomorphous substitution actions are presented and a Q-value matrix is maintained to assist the evolutionary test generation. A prototype called Evo Q is developed based on this approach and is applied to generate test cases for actual Java *** results show that Evo Q can efficiently generate test cases for SUT with ICH and NPM and achieves higher branch coverage than two state-of-the-art test generation approaches within the same time budget.

关键词： Object-oriented software Evolutionary testing Reinforcement learning Inherited class hierarchies Non-public methods.

A Verifiable Trust-Based CP-ABE Access Control Scheme for Cloud-Assisted Renewable Energy Systems

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computers, Materials & Continua 2025年第1期82卷 1211-1232页

作者： Jiyu Zhang Kehe Wu Ruomeng Yan Zheng Tian Yizhen Sun Yuxi Wu Yaogong Guo department of Control and computer Engineering North China Electric Power UniversityBeijing102206China State Grid Information&Communication Company of Hunan Electric Power Corporation Changsha410118China State Grid Hunan Electric Power Corporation Chenzhou Power Supply Branch Chenzhou423000China

Renewable Energy Systems(RES)provide a sustainable solution to climate warming and environmental pollution by enhancing stability and reliability through status acquisition and analysis on cloud platforms and intelligent processing on edge servers(ES).However,securely distributing encrypted data stored in the cloud to terminals that meet decryption requirements has become a prominent research ***,managing attributes,including addition,deletion,and modification,is a crucial issue in the access control scheme for *** address these security concerns,a trust-based ciphertext-policy attribute-based encryption(CP-ABE)device access control scheme is proposed for RES(TB-CP-ABE).This scheme effectivelymanages the distribution and control of encrypted data on the cloud through robust attribute key *** introducing trust management mechanisms and outsourced decryption technology,the ES system can effectively assess and manage the trust worthiness of terminal devices,ensuring that only trusted devices can participate in data exchange and access sensitive ***,the ES system dynamically evaluates trust scores to set decryption trust thresholds,thereby regulating device data access permissions and enhancing the system’s *** validate the security of the proposed TB-CP-ABE against chosen plaintext attacks,a comprehensive formal security analysis is conducted using the widely accepted random oraclemodel under the decisional q-Bilinear Diffie-Hellman Exponent(q-BDHE)***,comparative analysis with other schemes demonstrates that the TB-CP-ABE scheme cuts energy/communication costs by 43%,and scaleswell with rising terminals,maintaining average latency below 50ms,ensuring real-time service *** proposed scheme not only provides newinsights for the secure management of RES but also lays a foundation for future secure energy solutions.

关键词： Access control renewable energy systems(RES) ciphertext-policy attribute-based encryption(CP-ABE) security