期刊文献+
共找到17篇文章
< 1 >
每页显示 20 50 100
Security Test Case Prioritization through Ant Colony Optimization Algorithm
1
作者 Abdulaziz Attaallah Khalil al-Sulbi +5 位作者 Areej Alasiry Mehrez Marzougui Mohd Waris Khan Mohd Faizan Alka Agrawal Dhirendra Pandey 《Computer Systems Science & Engineering》 SCIE EI 2023年第12期3165-3195,共31页
Security testing is a critical concern for organizations worldwide due to the potential financial setbacks and damage to reputation caused by insecure software systems.One of the challenges in software security testin... Security testing is a critical concern for organizations worldwide due to the potential financial setbacks and damage to reputation caused by insecure software systems.One of the challenges in software security testing is test case prioritization,which aims to reduce redundancy in fault occurrences when executing test suites.By effectively applying test case prioritization,both the time and cost required for developing secure software can be reduced.This paper proposes a test case prioritization technique based on the Ant Colony Optimization(ACO)algorithm,a metaheuristic approach.The performance of the ACO-based technique is evaluated using the Average Percentage of Fault Detection(APFD)metric,comparing it with traditional techniques.It has been applied to a Mobile Payment Wallet application to validate the proposed approach.The results demonstrate that the proposed technique outperforms the traditional techniques in terms of the APFD metric.The ACO-based technique achieves an APFD of approximately 76%,two percent higher than the second-best optimal ordering technique.These findings suggest that metaheuristic-based prioritization techniques can effectively identify the best test cases,saving time and improving software security overall. 展开更多
关键词 CONFIDENTIALITY INTEGRITY AUTHENTICATION NON-REPUDIATION RESILIENCE AUTHORIZATION ant colony optimization algorithm
下载PDF
Research on Grid Planning of Dual Power Distribution Network Based on Parallel Ant Colony Optimization Algorithm
2
作者 Shuaixiang Wang 《Journal of Electronic Research and Application》 2023年第1期32-41,共10页
A distribution network plays an extremely important role in the safe and efficient operation of a power grid.As the core part of a power grid’s operation,a distribution network will have a significant impact on the s... A distribution network plays an extremely important role in the safe and efficient operation of a power grid.As the core part of a power grid’s operation,a distribution network will have a significant impact on the safety and reliability of residential electricity consumption.it is necessary to actively plan and modify the distribution network’s structure in the power grid,improve the quality of the distribution network,and optimize the planning of the distribution network,so that the network can be fully utilized to meet the needs of electricity consumption.In this paper,a distribution network grid planning algorithm based on the reliability of electricity consumption was completed using ant colony algorithm.For the distribution network structure planning of dual power sources,the parallel ant colony algorithm was used to prove that the premise of parallelism is the interactive process of ant colonies,and the dual power distribution network structure model is established based on the principle of the lowest cost.The artificial ants in the algorithm were compared with real ants in nature,and the basic steps and working principle of the ant colony optimization algorithm was studied with the help of the travelling salesman problem(TSP).Then,the limitations of the ant colony algorithm were analyzed,and an improvement strategy was proposed by using python for digital simulation.The results demonstrated the reliability of model-building and algorithm improvement. 展开更多
关键词 Parallel ant colony optimization algorithm Dual power sources Distribution network Grid planning
下载PDF
Feature Extraction of Stored-grain Insects Based on Ant Colony Optimization and Support Vector Machine Algorithm 被引量:1
3
作者 胡玉霞 张红涛 +1 位作者 罗康 张恒源 《Agricultural Science & Technology》 CAS 2012年第2期457-459,共3页
[Objective] The aim was to study the feature extraction of stored-grain insects based on ant colony optimization and support vector machine algorithm, and to explore the feasibility of the feature extraction of stored... [Objective] The aim was to study the feature extraction of stored-grain insects based on ant colony optimization and support vector machine algorithm, and to explore the feasibility of the feature extraction of stored-grain insects. [Method] Through the analysis of feature extraction in the image recognition of the stored-grain insects, the recognition accuracy of the cross-validation training model in support vector machine (SVM) algorithm was taken as an important factor of the evaluation principle of feature extraction of stored-grain insects. The ant colony optimization (ACO) algorithm was applied to the automatic feature extraction of stored-grain insects. [Result] The algorithm extracted the optimal feature subspace of seven features from the 17 morphological features, including area and perimeter. The ninety image samples of the stored-grain insects were automatically recognized by the optimized SVM classifier, and the recognition accuracy was over 95%. [Conclusion] The experiment shows that the application of ant colony optimization to the feature extraction of grain insects is practical and feasible. 展开更多
关键词 Stored-grain insects ant colony optimization algorithm Support vector machine Feature extraction RECOGNITION
下载PDF
Buffer allocation method of serial production lines based on improved ant colony optimization algorithm 被引量:2
4
作者 周炳海 Yu Jiadi 《High Technology Letters》 EI CAS 2016年第2期113-119,共7页
Buffer influences the performance of production lines greatly.To solve the buffer allocation problem(BAP) in serial production lines with unreliable machines effectively,an optimization method is proposed based on an ... Buffer influences the performance of production lines greatly.To solve the buffer allocation problem(BAP) in serial production lines with unreliable machines effectively,an optimization method is proposed based on an improved ant colony optimization(IACO) algorithm.Firstly,a problem domain describing buffer allocation is structured.Then a mathematical programming model is established with an objective of maximizing throughput rate of the production line.On the basis of the descriptions mentioned above,combining with a two-opt strategy and an acceptance probability rule,an IACO algorithm is built to solve the BAP.Finally,the simulation experiments are designed to evaluate the proposed algorithm.The results indicate that the IACO algorithm is valid and practical. 展开更多
关键词 buffer allocation improved ant colony optimization (IACO) algorithm serial pro-duction line throughput rate
下载PDF
Electro-Hydraulic Servo System Identification of Continuous Rotary Motor Based on the Integration Algorithm of Genetic Algorithm and Ant Colony Optimization 被引量:1
5
作者 王晓晶 李建英 +1 位作者 李平 修立威 《Journal of Donghua University(English Edition)》 EI CAS 2012年第5期428-433,共6页
In order to increase the robust performance of electro-hydraulic servo system, the system transfer function was identified by the intergration algorithm of genetic algorithm and ant colony optimization(GA-ACO), which ... In order to increase the robust performance of electro-hydraulic servo system, the system transfer function was identified by the intergration algorithm of genetic algorithm and ant colony optimization(GA-ACO), which was based on standard genetic algorithm and combined with positive feedback mechanism of ant colony algorithm. This method can obtain the precise mathematic model of continuous rotary motor which determines the order of servo system. Firstly, by constructing an appropriate fitness function, the problem of system parameters identification is converted into the problem of system parameter optimization. Secondly, in the given upper and lower bounds a set of optimal parameters are selected to meet the best approximation of the actual system. And the result shows that the identification output can trace the sampling output of actual system, and the error is very small. In addition, another set of experimental data are used to test the identification result. The result shows that the identification parameters can approach the actual system. The experimental results verify the feasibility of this method. And it is fit for the parameter identification of general complex system using the integration algorithm of GA-ACO. 展开更多
关键词 continuous rotary motor system identification genetic algorithm and ant colony optimization (GA-ACO) algorithm
下载PDF
Multi-Label Feature Selection Based on Improved Ant Colony Optimization Algorithm with Dynamic Redundancy and Label Dependence
6
作者 Ting Cai Chun Ye +5 位作者 Zhiwei Ye Ziyuan Chen Mengqing Mei Haichao Zhang Wanfang Bai Peng Zhang 《Computers, Materials & Continua》 SCIE EI 2024年第10期1157-1175,共19页
The world produces vast quantities of high-dimensional multi-semantic data.However,extracting valuable information from such a large amount of high-dimensional and multi-label data is undoubtedly arduous and challengi... The world produces vast quantities of high-dimensional multi-semantic data.However,extracting valuable information from such a large amount of high-dimensional and multi-label data is undoubtedly arduous and challenging.Feature selection aims to mitigate the adverse impacts of high dimensionality in multi-label data by eliminating redundant and irrelevant features.The ant colony optimization algorithm has demonstrated encouraging outcomes in multi-label feature selection,because of its simplicity,efficiency,and similarity to reinforcement learning.Nevertheless,existing methods do not consider crucial correlation information,such as dynamic redundancy and label correlation.To tackle these concerns,the paper proposes a multi-label feature selection technique based on ant colony optimization algorithm(MFACO),focusing on dynamic redundancy and label correlation.Initially,the dynamic redundancy is assessed between the selected feature subset and potential features.Meanwhile,the ant colony optimization algorithm extracts label correlation from the label set,which is then combined into the heuristic factor as label weights.Experimental results demonstrate that our proposed strategies can effectively enhance the optimal search ability of ant colony,outperforming the other algorithms involved in the paper. 展开更多
关键词 Multi-label feature selection ant colony optimization algorithm dynamic redundancy high-dimensional data label correlation
下载PDF
Solving algorithm for TA optimization model based on ACO-SA 被引量:4
7
作者 Jun Wang Xiaoguang Gao Yongwen Zhu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2011年第4期628-639,共12页
An ant colony optimization (ACO)-simulated annealing (SA)-based algorithm is developed for the target assignment problem (TAP) in the air defense (AD) command and control (C2) system of surface to air missi... An ant colony optimization (ACO)-simulated annealing (SA)-based algorithm is developed for the target assignment problem (TAP) in the air defense (AD) command and control (C2) system of surface to air missile (SAM) tactical unit. The accomplishment process of target assignment (TA) task is analyzed. A firing advantage degree (FAD) concept of fire unit (FU) intercepting targets is put forward and its evaluation model is established by using a linear weighted synthetic method. A TA optimization model is presented and its solving algorithms are designed respectively based on ACO and SA. A hybrid optimization strategy is presented and developed synthesizing the merits of ACO and SA. The simulation examples show that the model and algorithms can meet the solving requirement of TAP in AD combat. 展开更多
关键词 target assignment (TA) optimization ant colony optimization (ACO) algorithm simulated annealing (SA) algorithm hybrid optimization strategy.
下载PDF
Storage Assignment Optimization in a Multi-tier Shuttle Warehousing System 被引量:8
8
作者 WANG Yanyan MOU Shandong WU Yaohua 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第2期421-429,共9页
The current mathematical models for the storage assignment problem are generally established based on the traveling salesman problem(TSP),which has been widely applied in the conventional automated storage and retri... The current mathematical models for the storage assignment problem are generally established based on the traveling salesman problem(TSP),which has been widely applied in the conventional automated storage and retrieval system(AS/RS).However,the previous mathematical models in conventional AS/RS do not match multi-tier shuttle warehousing systems(MSWS) because the characteristics of parallel retrieval in multiple tiers and progressive vertical movement destroy the foundation of TSP.In this study,a two-stage open queuing network model in which shuttles and a lift are regarded as servers at different stages is proposed to analyze system performance in the terms of shuttle waiting period(SWP) and lift idle period(LIP) during transaction cycle time.A mean arrival time difference matrix for pairwise stock keeping units(SKUs) is presented to determine the mean waiting time and queue length to optimize the storage assignment problem on the basis of SKU correlation.The decomposition method is applied to analyze the interactions among outbound task time,SWP,and LIP.The ant colony clustering algorithm is designed to determine storage partitions using clustering items.In addition,goods are assigned for storage according to the rearranging permutation and the combination of storage partitions in a 2D plane.This combination is derived based on the analysis results of the queuing network model and on three basic principles.The storage assignment method and its entire optimization algorithm method as applied in a MSWS are verified through a practical engineering project conducted in the tobacco industry.The applying results show that the total SWP and LIP can be reduced effectively to improve the utilization rates of all devices and to increase the throughput of the distribution center. 展开更多
关键词 Multi-tier shuttle warehousing system storage assignment optimization open queuing network ant colony clustering algorithm
下载PDF
Research of Rural Power Network Reactive Power Optimization Based on Improved ACOA
9
作者 YU Qian ZHAO Yulin WANG Xintao 《Journal of Northeast Agricultural University(English Edition)》 CAS 2010年第3期48-52,共5页
In view of the serious reactive power loss in the rural network, improved ant colony optimization algorithm (ACOA) was used to optimize the reactive power compensation for the rural distribution system. In this stud... In view of the serious reactive power loss in the rural network, improved ant colony optimization algorithm (ACOA) was used to optimize the reactive power compensation for the rural distribution system. In this study, the traditional ACOA was improved in two aspects: one was the local search strategy, and the other was pheromone mutation and re-initialization strategies. The reactive power optimization for a county's distribution network showed that the improved ACOA was practicable. 展开更多
关键词 rural power network reactive power optimization ant colony optimization algorithm local search strategy pheromone mutation and re-initialization strategy
下载PDF
Energy-efficient task allocation for reliable parallel computation of cluster-based wireless sensor network in edge computing
10
作者 Jiabao Wen Jiachen Yang +2 位作者 Tianying Wang Yang Li Zhihan Lv 《Digital Communications and Networks》 SCIE CSCD 2023年第2期473-482,共10页
To efficiently complete a complex computation task,the complex task should be decomposed into subcomputation tasks that run parallel in edge computing.Wireless Sensor Network(WSN)is a typical application of parallel c... To efficiently complete a complex computation task,the complex task should be decomposed into subcomputation tasks that run parallel in edge computing.Wireless Sensor Network(WSN)is a typical application of parallel computation.To achieve highly reliable parallel computation for wireless sensor network,the network's lifetime needs to be extended.Therefore,a proper task allocation strategy is needed to reduce the energy consumption and balance the load of the network.This paper proposes a task model and a cluster-based WSN model in edge computing.In our model,different tasks require different types of resources and different sensors provide different types of resources,so our model is heterogeneous,which makes the model more practical.Then we propose a task allocation algorithm that combines the Genetic Algorithm(GA)and the Ant Colony Optimization(ACO)algorithm.The algorithm concentrates on energy conservation and load balancing so that the lifetime of the network can be extended.The experimental result shows the algorithm's effectiveness and advantages in energy conservation and load balancing. 展开更多
关键词 Wireless sensor network Parallel computation Task allocation Genetic algorithm ant colony optimization algorithm ENERGY-EFFICIENT Load balancing
下载PDF
Automatic Driving Material Handling Vehicle Station Location and Scheduling Mathematical Modeling and Analysis
11
作者 Qi Zhang Qiaozhen Zhang 《Journal of Applied Mathematics and Physics》 2023年第9期2630-2643,共14页
Traditional material handling vehicles often use internal combustion engines as their power source, which results in exhaust emissions that pollute the environment. In contrast, automated material handling vehicles ha... Traditional material handling vehicles often use internal combustion engines as their power source, which results in exhaust emissions that pollute the environment. In contrast, automated material handling vehicles have the advantages of zero emissions, low noise, and low vibration, thus avoiding exhaust pollution and providing a more comfortable working environment for operators. In order to achieve the goals of “peaking carbon emissions by 2030 and achieving carbon neutrality by 2060”, the use of environmentally friendly autonomous material handling vehicles for material transportation is an inevitable trend. To maximize the amount of transported materials, consider peak-to-valley electricity pricing, battery pack procurement, and the construction of charging and swapping stations while achieving “minimum daily transportation volume” and “lowest investment and operational cost over a 3-year settlement period” with the shortest overall travel distance for all material handling vehicles, this paper examines two different scenarios and establishes goal programming models. The appropriate locations for material handling vehicle swapping stations and vehicle battery pack scheduling schemes are then developed using the NSGA-II algorithm and ant colony optimization algorithm. The results show that, while ensuring a daily transportation volume of no less than 300 vehicles, the lowest investment and operational cost over a 3-year settlement period is approximately 24.1 million Yuan. The material handling vehicles follow the shortest path of 119.2653 km passing through the designated retrieval points and have two shortest routes. Furthermore, the advantages and disadvantages of the proposed models are analyzed, followed by an evaluation, deepening, and potential extension of the models. Finally, future research directions in this field are suggested. 展开更多
关键词 Electric Material Handling Vehicles Battery Swap Station Location Scheduling Scheme NSGA-II Algorithm ant colony optimization Algorithm
下载PDF
The analysis of the convergence of ant colony optimization algorithm
12
作者 ZHU Qingbao WANG Lingling 《Frontiers of Electrical and Electronic Engineering in China》 CSCD 2007年第3期268-272,共5页
The ant colony optimization algorithm has been widely studied and many important results have been obtained.Though this algorithm has been applied to many fields,the analysis about its convergence is much less,which w... The ant colony optimization algorithm has been widely studied and many important results have been obtained.Though this algorithm has been applied to many fields,the analysis about its convergence is much less,which will influence the improvement of this algorithm.Therefore,the convergence of this algorithm applied to the traveling salesman problem(TSP)was analyzed in detail.The conclusion that this algorithm will definitely converge to the optimal solution under the condition of 0<q_(0)<1 was proved true.In addition,the influence on its convergence caused by the properties of the closed path,heuristic functions,the pheromone and q_(0) was analyzed.Based on the above-mentioned,some conclusions about how to improve the speed of its convergence are obtained. 展开更多
关键词 ant colony optimization algorithm convergence analysis heuristic function TSP
原文传递
Gear Fault Recognition and Diagnosis Based on Ant Colony Optimization Algorithm
13
作者 Mingzan Wang Jinzhong He 《Journal of Systems Science and Information》 2006年第3期495-500,共6页
introduce a new kind of swarm intelligence algorithm, the Ant Colony Optimization (ACO) algorithm. Propose a clustering analysis model based on ACO, apply the model to recognition and diagnosis of operation state fo... introduce a new kind of swarm intelligence algorithm, the Ant Colony Optimization (ACO) algorithm. Propose a clustering analysis model based on ACO, apply the model to recognition and diagnosis of operation state for gearbox. Testing four kinds of gears and clustering some characteristic parameters of the gear vibration signal, the conclusion shows that this method can recognize running state with accuracy and all speed. It is a new method for fault recognition and diagnosis. 展开更多
关键词 ant colony optimal algorithm CLUSTERING fault diagnosis RECOGNITION
原文传递
Genetic algorithm for short-term scheduling of make-and-pack batch production process 被引量:1
14
作者 Wuthichai Wongthatsanekorn Busaba Phruksaphanrat 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第9期1475-1483,共9页
This paper considers a scheduling problem in industrial make-and-pack batch production process. This process equips with sequence-dependent changeover time, multipurpose storage units with limited capacity, storage ti... This paper considers a scheduling problem in industrial make-and-pack batch production process. This process equips with sequence-dependent changeover time, multipurpose storage units with limited capacity, storage time, batch splitting, partial equipment connectivity and transfer time. The objective is to make a production plan to satisfy all constraints while meeting demand requirement of packed products from various product families. This problem is NP-hard and the problem size is exponentially large for a realistic-sized problem. Therefore,we propose a genetic algorithm to handle this problem. Solutions to the problems are represented by chromosomes of product family sequences. These sequences are decoded to assign the resource for producing packed products according to forward assignment strategy and resource selection rules. These techniques greatly reduce unnecessary search space and improve search speed. In addition, design of experiment is carefully utilized to determine appropriate parameter settings. Ant colony optimization and Tabu search are also implemented for comparison. At the end of each heuristics, local search is applied for the packed product sequence to improve makespan. In an experimental analysis, all heuristics show the capability to solve large instances within reasonable computational time. In all problem instances, genetic algorithm averagely outperforms ant colony optimization and Tabu search with slightly longer computational time. 展开更多
关键词 Genetic algorithm ant colony optimization Tabu search Batch scheduling Make-and-pack production Forward assignment strategy
下载PDF
Performance optimization of the elliptically vibrating screen with a hybrid MACO-GBDT algorithm 被引量:2
15
作者 Zhiquan Chen Zhanfu Li +1 位作者 Huihuang Xia Xin Tong 《Particuology》 SCIE EI CAS CSCD 2021年第3期193-206,共14页
As a typical screening apparatus,the elliptically vibrating screen was extensively employed for the size classification of granular materials.Unremitting efforts have been paid on the improvement of sieving performanc... As a typical screening apparatus,the elliptically vibrating screen was extensively employed for the size classification of granular materials.Unremitting efforts have been paid on the improvement of sieving performance,but the optimization problem was still perplexing the researchers due to the complexity of sieving process.In the present paper,the sieving process of elliptically vibrating screen was numerically simulated based on the Discrete Element Method(DEM).The production quality and the processing capacity of vibrating screen were measured by the screening efficiency and the screening time,respectively.The sieving parameters including the length of semi-major axis,the length ratio of two semi-axes,the vibration frequency,the inclination angle,the vibration direction angle and the motion direction of screen deck were investigated.Firstly,the Gradient Boosting Decision Trees(GBDT)algorithm was adopted in the modelling task of screening data.The trained prediction models with sufficient generalization performance were obtained,and the relative importance of six parameters for both the screening indexes was revealed.After that,a hybrid MACO-GBDT algorithm based on the Ant Colony Optimization(ACO)was proposed for optimizing the sieving performance of vibrating screen.Both the single objective optimization of screening efficiency and the stepwise optimization of screening results were conducted.Ultimately,the reliability of the MACO-GBDT algorithm were examined by the numerical experiments.The optimization strategy provided in this work would be helpful for the parameter design and the performance improvement of vibrating screens. 展开更多
关键词 Discrete Element Method(DEM) Elliptically vibrating screen Sieving performance Gradient Boosting Decision Trees(GBDT) ant colony optimization(ACO)algorithm
原文传递
Hierarchical method of task assignment for multiple cooperating UAV teams 被引量:17
16
作者 Xiaoxuan Hu Huawei Ma +1 位作者 Qingsong Ye He Luo 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2015年第5期1000-1009,共10页
The problem of task assignment for multiple cooperating unmanned aerial vehicle(UAV) teams is considered. Multiple UAVs forming several small teams are needed to perform attack tasks on a set of predetermined ground t... The problem of task assignment for multiple cooperating unmanned aerial vehicle(UAV) teams is considered. Multiple UAVs forming several small teams are needed to perform attack tasks on a set of predetermined ground targets. A hierarchical task assignment method is presented to address the problem. It breaks the original problem down to three levels of sub-problems: target clustering, cluster allocation and target assignment. The first two sub-problems are centrally solved by using clustering algorithms and integer linear programming, respectively, and the third sub-problem is solved in a distributed and parallel manner, using a mixed integer linear programming model and an improved ant colony algorithm. The proposed hierarchical method can reduce the computational complexity of the task assignment problem considerably, especially when the number of tasks or the number of UAVs is large. Experimental results show that this method is feasible and more efficient than non-hierarchical methods. 展开更多
关键词 unmanned aerial vehicle (UAV) task assignment CLUSTERING integer linear programming ant colony optimization(ACO) algorithm
原文传递
RFES: a real-time fire evacuation system for Mobile Web3D 被引量:3
17
作者 Feng-ting YAN Yong-hao HU +3 位作者 Jin-yuan JIA Qing-hua GUO He-hua ZHU Zhi-geng PAN 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2019年第8期1061-1075,共15页
There are many bottlenecks that limit the computing power of the Mobile Web3 D and they need to be solved before implementing a public fire evacuation system on this platform.In this study,we focus on three key proble... There are many bottlenecks that limit the computing power of the Mobile Web3 D and they need to be solved before implementing a public fire evacuation system on this platform.In this study,we focus on three key problems:(1)The scene data for large-scale building information modeling(BIM)are huge,so it is difficult to transmit the data via the Internet and visualize them on the Web;(2)The raw fire dynamic simulator(FDS)smoke diffusion data are also very large,so it is extremely difficult to transmit the data via the Internet and visualize them on the Web;(3)A smart artificial intelligence fire evacuation app for the public should be accurate and real-time.To address these problems,the following solutions are proposed:(1)The large-scale scene model is made lightweight;(2)The amount of dynamic smoke is also made lightweight;(3)The dynamic obstacle maps established from the scene model and smoke data are used for optimal path planning using a heuristic method.We propose a real-time fire evacuation system based on the ant colony optimization(RFES-ACO)algorithm with reused dynamic pheromones.Simulation results show that the public could use Mobile Web3 D devices to experience fire evacuation drills in real time smoothly.The real-time fire evacuation system(RFES)is efficient and the evacuation rate is better than those of the other two algorithms,i.e.,the leader-follower fire evacuation algorithm and the random fire evacuation algorithm. 展开更多
关键词 Fire evacuation drill Building information modeling(BIM)building space Mobile Web3D Real-time fire evacuation system based on ant colony optimization(RFES-ACO)algorithm
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部