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971.
According to the Third Greenhouse Gas (GHG) Study 2014 of International Maritime Organization (IMO), the total emission in 2012 are estimated to be 949 million tonnes which is 2.7% of global CO2 emission by total shipping and expected to increase from 2012 levels by 50–250% by 2050. Significant changes are needed to all industry by implementation of energy efficiency design and operational measures to meet existing and future global emission reduction targets. Although the fuel cost-reducing effects of some energy efficiency measures and new technologies are well established and matured, shipping companies appear reluctant to adopt them. Besides, it is observed that the stakeholders are directly or indirectly involved for implementation of energy efficiency measures in shipping industry. Therefore, the objective for this study was to identify the barriers to energy efficiency operational measures by a qualitative survey among various stakeholders from all corners of shipping industry. It has been found in the research that the barriers for implementation of all cost-free operational measures are almost the same such as lack of information of the measure, lack of awareness and competence of ship crews and operation difficulties which are in nature of information and technical barriers. But financial issue and owner’s interest are the key barriers for some other operational measures which are related to costing and need investment for implementation. 相似文献
972.
Xuyu Hu 《WMU Journal of Maritime Affairs》2018,17(3):347-375
Mandatory rules exist in contracts for international liner shipping primarily because of imbalances and non-equity in the allocation of contract responsibilities. The superior bargaining position owned by the carriers depends largely upon liner market monopoly levels, the supply and demand balance between the shipper and carrier, and the cargo volume size of the shippers. With the development of shipping technologies, mode of transport, and shipping competition policy, the unequal comparison of bargaining forces between shippers and carriers changes. When the existing mandatory rule was deemed no longer necessary due to changing circumstances, legislation requirements to restore freedom to contract became apparent. When both sides have equal bargaining power, adoption of the principle of freedom of contract for their business relationships is suitable. The Rotterdam Rules concerning freedom of volume contract construction is based on equal bargaining powers between both sides and responds to the evolving situation of the industry. The Rules represent the development trend of today’s theory of contracts for international liner shipping and the demand for legal and institutional changes. 相似文献
973.
基于K最近邻决策的支持向量机分类算法及仿真 总被引:2,自引:0,他引:2
将基于支持向量机(SVM)的分类方法和最近邻法(NN)相结合,提出了一种SVM-KNN的分类方法。通过SVM算法对训练样本进行训练并找出支持向量,在进行待识别样本判断时,当其与最优分类面距离大于某一给定阈值时采用SVM决策模型,否则运用K最近邻法决策其类别,从而减少SVM算法的误判概率。仿真实验结果显示,运用该算法无论对于合成数据还是真实数据,在分类精度上比单独的SVM都有较明显的提高。 相似文献
974.
975.
Hamid Bazargan Hamid Bahai Amin Aminzadeh–Gohari 《Journal of Marine Science and Technology》2007,12(1):34-42
This study presents a new method for calculating return values. The essence of the method is that it utilizes nonstationary
data to calculate the return value for a region in the Northeast Pacific. The nonstationary data was obtained from a model
which was previously developed for the behavior of the significant wave height as a function of time in the region. The method
is illustrated by convolving two generalized Pareto distribution functions fitted to two parts of the model, computing a suitable
extreme value from the new distribution function, and calculating the return value using this extreme value. 相似文献
976.
Genetic algorithms (GAs) can powerfully search for parameters in a large multidimensional design space. Thus, the principle
can be applied to preliminary series propeller design problems with multiple considerations. In the present study, B-series
propeller design was conducted using a GA for both hydrodynamic efficiency and vibration consideration. The objective function
was set by users who could freely weight the relative importance of efficiency and vibration. GAs were successfully shown
to be able to obtain an optimal set of parameters leading to efficient performance and low vibration. 相似文献
977.
WANG Bai-he HUANG Jian-guo 《船舶与海洋工程学报》2007,6(4):13-17
A classical time-varying signal,the multi-component Chirp signal has been widely used and the ability to estimate its instantaneous frequency(IF) is very useful. But in noisy environments,it is hard to estimate the IF of a multi-component Chirp signal accurately. Wigner distribution maxima(WDM) are usually utilized for this estimation. But in practice,estimation bias increases when some points deviate from the true IF in high noise environments. This paper presents a new method of multi-component Chirp signal IF estimation named Wigner Viterbi fit(WVF) ,based on Wigner-Ville distribution(WVD) and the Viterbi algorithm. First,we transform the WVD of the Chirp signal into digital image,and apply the Viterbi algorithm to separate the components and estimate their IF. At last,we establish a linear model to fit the estimation results. Theoretical analysis and simulation results prove that this new method has high precision and better performance than WDM in high noise environments,and better suppression of interference and the edge effect. Compared with WDM,WVF can reduce the mean square error(MSE) by 50% when the signal to noise ration(SNR) is in the range of -15dB to -11dB. WVF is an effective and promising IF estimation method. 相似文献
978.
多媒体教学作为一种新兴的教学手段,在教育过程中显示出了明显的优势,弥补了传统教学方法的不足;但是,在应用多媒体技术进行教学时,因为对多媒体教学的优缺点认识不到位,使得在教学中容易出现一些漏洞,从而影响了多媒体技术在教学中的普及、推广和优势的发挥。解决这一问题的方法应该多媒体教学和传统教学方法相结合,互为补充,这样才能取得较好的教学效果。 相似文献
979.
分析了两种常用CAD软件Inventor和AutoCAD的优缺点,提出了一种利用Inventor制作的三维模型生成AutoCAD工程图的方法,以及在AutoCAD中将其标准化的一些技巧。集成Inventor和AutoCAD的优点应用于产品结构设计,可提高设计绘图的效率和质量。 相似文献
980.
Martin F. Diez-Picazo 《WMU Journal of Maritime Affairs》2007,6(2):241-247
A cross-cutting Maritime Policy can ensure that climate change threats and challenges in regards to seas and oceans are dealt
with in a wide policy framework that takes into account the impacts that climate change may have on other sectors and vice
versa. 相似文献