期刊文献+
共找到5篇文章
< 1 >
每页显示 20 50 100
Estimating Tree Canopy Cover and Identifying Deforestation Patterns in Meghalaya (1990-2021) through ML Classifiers
1
作者 Tapan Dhar Sengalvarayan Aravindan Basudeb Bhatta 《Journal of Geographic Information System》 2023年第3期309-333,共25页
This study utilizes ML classifiers to estimate canopy density based on three decades of data (1990-2021). The Support Vector Machine (SVM) classifier outperformed other classifiers, such as Random Tree and Maximum Lik... This study utilizes ML classifiers to estimate canopy density based on three decades of data (1990-2021). The Support Vector Machine (SVM) classifier outperformed other classifiers, such as Random Tree and Maximum Likelihood. Satellite data from Landsat and Sentinel 2 was classified using a developed python model, providing an economical and time-saving approach. The accuracy of the classification was evaluated through a confusion matrix and area computation. The findings indicate a negative trend in the overall decadal change, with significant tree loss attributed to jhum cultivation, mining, and quarry activities. However, positive changes were observed in recent years due to the ban on illegal mining. The study highlights the dynamic nature of tree cover and emphasizes the need for biennial assessments using at least five time-series data. Micro-level analysis in Shallang, West Khasi hills, revealed a concerning trend of shortening jhum cycles. Automation in canopy change analysis is crucial for effective forest monitoring, providing timely information for law enforcement proposals and involving forest managers, stakeholders, and watchdog organizations. 展开更多
关键词 MEGHALAYA Forest Cover ML SVM Python Script Decadal Change Biennial Change
下载PDF
Multi-objectives fuzzy optimization model for ship form demonstration based on information entropy 被引量:4
2
作者 ZHANG Wei-ying LIN Yan +1 位作者 JI Zhuo-shang DENG Lin-yi 《Journal of Marine Science and Application》 2006年第1期12-16,共5页
Selecting optimization ship form scheme is an important content in the process of concept design of ship. Multi-objective fuzzy decision-making model for ship form demonstration is set up according to the fuzzy patter... Selecting optimization ship form scheme is an important content in the process of concept design of ship. Multi-objective fuzzy decision-making model for ship form demonstration is set up according to the fuzzy pattern-recognition theory. Weight coefficients of each target of ship form scheme are determined by information entropy and individual subjective partiality. This model is used to select the optimal ship form scheme,the example shows that the model is exact and the result is credible. It can provide a reference for choosing the optimization scheme of ship form. 展开更多
关键词 船舶 技术性能 信息学 模糊理论
下载PDF
Model and algorithm for container ship stowage planning based on bin-packing problem 被引量:4
3
作者 ZHANG Wei-ying LIN Yan JI Zhuo-shang 《Journal of Marine Science and Application》 2005年第3期30-36,共7页
In a general case, container ship serves many different ports on each voyage. A stowage planning for container ship made at one port must take account of the influence on subsequent ports. So the complexity of stowage... In a general case, container ship serves many different ports on each voyage. A stowage planning for container ship made at one port must take account of the influence on subsequent ports. So the complexity of stowage planning problem increases due to its multi-ports nature. This problem is NP-hard problem. In order to reduce the computational complexity, the problem is decomposed into two sub-problems in this paper. First, container ship stowage problem (CSSP) is regarded as 'packing problem', ship-bays on the board of vessel are regarded as bins, the number of slots at each bay are taken as capacities of bins, and containers with different characteristics (homogeneous containers group) are treated as items packed. At this stage, there are two objective functions, one is to minimize the number of bays packed by containers and the other is to minimize the number of overstows. Secondly, containers assigned to each bays at first stage are allocate to special slot, the objective functions are to minimize the metacentric height, heel and overstows.The taboo search heuristics algorithm are used to solve the subproblem. The main focus of this paper is on the first subproblem. A case certifies the feasibility of the model and algorithm. 展开更多
关键词 集装箱运输 船舶 堆装物 CSSP
下载PDF
Review of containership stowage plans for full routes 被引量:2
4
作者 张维英 林焰 +1 位作者 纪卓尚 张光发 《Journal of Marine Science and Application》 2008年第4期278-285,共8页
Containership stowage plans are a pivotal teaches in the system of container transportation.With the increasing containers shipping,planning containership stowage has become more and more complicated.So intelligent st... Containership stowage plans are a pivotal teaches in the system of container transportation.With the increasing containers shipping,planning containership stowage has become more and more complicated.So intelligent stowage planning for containerships is of great significance.An effective stowage plan may improve efficiency of transportation system.First,the progress of containership stowage plan at home and abroad is reviewed,including the latest developments,such as the application of various optimization methods and computer techniques to the problem.Then,the complexities of the problem are discussed and areas where investigations are still needed are pointed out.This will provide a reference for further research on the subject. 展开更多
关键词 集装箱 海洋运输 堆装物 智能装载
下载PDF
Research on the Optimization Approach for Cargo Oil Tank Design Based on the Improved Particle Swarm Optimization Algorithm 被引量:1
5
作者 姜文英 林焰 +1 位作者 陈明 于雁云 《Journal of Shanghai Jiaotong university(Science)》 EI 2015年第5期565-570,共6页
Based on the improved particle swarm optimization(PSO) algorithm,an optimization approach for the cargo oil tank design(COTD) is presented in this paper.The purpose is to design an optimal overall dimension of the car... Based on the improved particle swarm optimization(PSO) algorithm,an optimization approach for the cargo oil tank design(COTD) is presented in this paper.The purpose is to design an optimal overall dimension of the cargo oil tank(COT) under various kinds of constraints in the preliminary design stage.A non-linear programming model is built to simulate the optimization design,in which the requirements and rules for COTD are used as the constraints.Considering the distance between the inner shell and hull,a fuzzy constraint is used to express the feasibility degree of the double-hull configuration.In terms of the characteristic of COTD,the PSO algorithm is improved to solve this problem.A bivariate extremum strategy is presented to deal with the fuzzy constraint,by which the maximum and minimum cargo capacities are obtained simultaneously.Finally,the simulation demonstrates the feasibility and effectiveness of the proposed approach. 展开更多
关键词 船舶 CAD COTD 设计
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部