共查询到19条相似文献，搜索用时 203 毫秒
1.
Non-Rigid Medical Image Registration with Joint Histogram Estimation Based on Mutual Information 总被引：1，自引：0，他引：1
A mutual information-based non-rigid medical image registration algorithm is presented. An approximate function of Hanning windowed sinc is used as kernel function of partial volume (PV) interpolation to estimate the joint histogram, which is the key to calculating the mutual information. And a new method is proposed to compute the gradient of mutual information with respect to the model parameters. The transformation of object is modeled by a free-form deformation (FFD) based on B-splines. The experiments on 3D synthetic and real image data show that the algorithm can converge at the global optimum and restrain the emergency of local extreme. 相似文献
2.
Multi-attribute decision-making approach dealing with uncertain linguistic assessment information 总被引：1，自引：0，他引：1
Gu Jing Zhou Zongfang 《东南大学学报》2008,(Z1)
An approach is presented to deal with a multi-attribute decision-making problem in which the attribute weights are unknown and the attribute values take the form of uncertain linguistic variables. First, a linguistic assessment standard is set up to deal with the uncertain linguistic attributes, and the operation laws of uncertain linguistic variables and the uncertain linguistic weighting average(ULWA)operator are introduced. Then a ranking formula of uncertain linguistic variables based on expectation-variance is proposed. As for the case without weight information, a goal program based on a warp function is constructed to determine the attribute weights, and the ULWA operator is utilized to aggregate the assessment information of uncertain linguistic variables, and the corresponding alternatives are ranked by a formula based on expectation-variance. Finally, a numerical example is given, and the results demonstrate that it is much easier and faster for the ranking method based on expectation-variance when compared to the existing methods. 相似文献
3.
A cluster analyzing algorithm based on grids is introduced in this paper,which is applied to data mining in the city emergency system. In the previous applications, data mining was based on the method of analyzing points and lines, which was not efficient enough in dealing with the geographic information in units of police areas. The proposed algorithm maps an event set stored as a point set to a grid unit set, utilizes the cluster algorithm based on grids to find out all the clusters, and shows the results in the method of visualization. The algorithm performs well when dealing with high dimensional data sets and immense data. It is suitable for the data mining based on geographic information system and is supportive to decision-makings in the city emergency system. 相似文献
4.
Traditional methods for detecting symmetry in image suffer greatly from the contrast of im-age and noise, and they all require some preprocessing. This paper presents a new method of im-age symmetry detection. This method detects symmetry with phase information utilizing logGabor wavelets,because phase information is stable and significant, while symmetric points produce pat-terns easy to be recognised and confirmable in local phase. Phase method does not require any preprocessing. and its result is accurate or invariant to contrast, rotation and illumination conditions. This method can detect mirror symmetry, rotating symmetry and curve symmetry at one time. Results of experiment show that, compared with pivotal element algorithm based on intensity information, phase method is more accurate and robust. 相似文献
5.
Ram Bahal Monika Wason Sudeep 《美中教育评论》2006,3(5):58-65
Looking the progress of cyber based information system in railways, air ways, commercial institutions, industries, medical institutions etc. a pertinent questions is raised that why not in agriculture？ It is however, realized that due to short supply of extension workers, their lower educational level and least per capita extension expenditure, the demand based extension services are not been provided to different kinds of clients. Due to diversification of agriculture, the needs are varying from farmer to farmer and area to area. Farmers need different calculated feasible, viable and economical practices to follow for better output and income. The socio-economic and agro-climatic situation of farmers in the same village is also different. Therefore, demand based extension services cannot be possible through our conventional system of extension with the available human and financial resources. So far, extension agents give the information what ever they know and not that what the farmers need. It is therefore suggested to develop cyber based extension system in our country, which provides all required information about all possible questions of the farmers. Keeping this point in view, an effort was made to develop an Expert System of Extension at Division of Agricultural Extension, Indian Agricultural Research Institute New Dlehi-12. The system was built in two phases. In the first phase the agricultural information of the selected crops have been collected from the authentic sources and stored in the form of a database. In the second phase, the decision rules were formulated and coded in the expert system. Both these phases are finally combined to form cyber-based expert system, which is hosted on the Internet for the use of the farmers and general public. This is a best combination of man and machine for efficiency and need to based on dissemination at a time to all farmers. 相似文献
6.
A new algorithm is presented by using the ant colony algorithm based on genetic method (ACG) to solve the continuous optimization problem.Each component has a seed set.The seed in the set has the value of component,trail information and fitness.The ant chooses a seed from the seed set with the possibility determined by trail information and fitness of the seed.The genetic method is used to form new solutions from the solutions got by the ants.Best solutions are selected to update the seeds in the sets and trail information of the seeds.In updating the trail information,a diffusion function is used to achieve the diffuseness of trail information.The new algorithm is tested with 8 different benchmark functions. 相似文献
7.
The term "soft power" is coined by a noted American scholar Joseph Nye. It means a nation’s ability to get others to do what it wants without either coercive military or economic pressures, or material inducements. It is the attractiveness and seduction, the resources of which include culture, values, political ideas and policies. During the past two decades, the soft power concept has gained widespread acceptance and usage. In a global information age and in a multi-polarized world, the US government has all along attached much importance to the exercise of soft power in foreign policies. It goes to great lengths to advance its universal culture and values, promote public diplomacy, and shape the world order by helping establish the international institutions and norms. The US government draws on the resources of soft power to improve the national image and thus promote its popularity across the world with a view to serving the national interests. The idea of soft power improves the traditional concept of power, enriches the practice of the US diplomacy. However, we shouldn’t fail to see that it is based on US superiority with the ultimate goal of achieving US hegemony. But still we can learn something from the concept and introduce it into our policies. 相似文献
8.
Unbalanced energy consumption distribution caused by the concentration of facilities and population topples the natural energy equilibrium of a city and causes environmental problems such as urban tropical night, heat island phenomenon, global warming deterioration. Therefore, to secure eco-friendliness and sustainability of a city, it is necessary to introduce measures to alleviate the unequal distribution phenomenon of urban energy consumption from the city planning stage. For this purpose, the first step is to understand the current energy environment. The urban energy environment is affected by many factors in addition to gathering of buildings. Therefore, there is a limit to fully understanding advanced urban energy environment with only simple statistical urban information management technique. Research on methods of analyzing urban energy environment through simulation of recent urban scale is underway. There is not enough discussion about basic informaion databases for environmental analysis simulation of urban energy. This study presents a method using GIS (geographic information system) and web-based environmental information database as a way to improve the simulation accuracy. First, environmental information factors used for urban simulation were derived, and a web-based environmental information database targeting Daegu metropolitan city of Korea was built. Then, the urban energy environment was analyzed on a trial basis by linking the database with GIS. 相似文献
9.
《英语辅导》2005,(1)
Witch-HuntA deliberate attempt to find and punish people whose opinions are seen as wrong or dangerous. Often this is based on false information, and the people who are punished in a witch-hunt are often completely innocent. An example: During the 1950s, there was a witch-hunt in the USA organized against the 相似文献
10.
Effective and robust recognition and tracking of objects are the key problems in visual surveillance systems. Most existing object recognition methods were designed with particular objects in mind. This study presents a general moving objects recognition method using global features of targets. Targets are extracted with an adaptive Gaussian mixture model and their silhouette images are captured and unified. A new objects silhouette database is built to provide abundant samples to train the subspace feature. This database is more convincing than the previous ones. A more effective dimension reduction method based on graph embedding is used to obtain the projection eigenvector. In our experiments, we show the effective performance of our method in addressing the moving objects recognition problem and its superiority compared with the previous methods. 相似文献
11.
图卷积网络由于能够直接处理图结构数据的优点而受到广泛研究。当前的多数图卷积网络是基于图信号的平滑性(低频信息),且不能根据各节点适合的接受域生成对应的节点嵌入,随着网络层数的增加,易出现图卷积网络特有的过平滑问题而导致性能下降。为此,提出了基于自适应频率和动态节点嵌入的图卷积网络模型(adaptive frequency and dynamic node embedding based graph convolutional network, FDGCN)。FDGCN模型能够自适应聚合不同频率的信息,同时利用每层网络的输出,平衡每个节点来自全局和局部领域的信息,动态地调节节点嵌入。通过在4个公共数据集上进行实验,对比了6个现有模型,证明了FDGCN模型的有效性。 相似文献
12.
一个描述可视化语言上下文属性化的图文法框架 总被引：2，自引：0，他引：2
针对目前已有的上下文相关图文法的描述规范过于复杂或不太直观,提出了一个新的上下文相关图文法的形式框架：上下文属性化的图文法CAGG．该文法将产生式的上下文信息刻画成相关结点的上下文属性来解决嵌入问题．而且进一步分析了合流的CAGG产生式集合的基本特征,并基于此设计了合流产生式集合的判定算法,从而为构造高效的语法分析算法奠定了基础．通过与已有上下文相关图文法的对比分析可知,CAGG图文法的形式更为简洁和直观,因而更适于且更易于应用到可视化语言描述领域． 相似文献
13.
Rosanne W. Fortner Jae-Young Lee Jeffrey R. Corney Samantha Romanello Joseph Bonnell Brian Luthy 《Environmental Education Research》2000,6(2):127-141
During a 10-week period prior to the 1997 Kyoto conference on climate change, two parallel studies were conducted: Study 1 examined media portrayals of global warming and the certainty with which information was reported (percentage of 'hedging'); Study 2 was a telephone survey to assess public knowledge about key topics in global climate change, people's certainty about their information, trust in the media, and willingness to take action on global warming. Media reports were found to be scarce, and about half of the references to global warming were found to be hedged. More hedging was evident in the New York Times than in other print media and national television reports, and economic impacts of climate change were reported with the greatest certainty. The audience (N = 139 adults, average age 36–45, with at least a high school education) reported trusting their media sources more than 50% of the time. They were collectively fairly knowledgeable and certain about global warming information (9.1 on a scale of - 20 to + 20), and they appeared to be willing to adopt a range of responsible behaviors seen to be useful in countering global warming (average response 3.0 out of 4). The knowledge/certainty factor was described as 'attitude under uncertainty', and was significantly related to media trust (r = 0.325, p < 0.01) and willingness to act responsibly (r = 0.400, p < 0.01). Comparing Study 1 with Study 2, the research does not support a hypothesis that media hedging is related to uncertainty. Implications for environmental communicators are discussed. 相似文献
14.
This paper introduces a family of error-correcting codes called zigzag codes.A zigzag code is described by a highly structured zigzag graph.Due to the structureal properties of the graph,very low-complexity soft-in,soft-out decoding rules can be implemented.we present a decoding rule,absed on the Max-Log-APP(MLA) formulation,which requires a total of only 20 addition-equivalent-operations per information bit per iteration.Simulation of a rate-1/2 concatenated zigzag code with four constitutent encoders with interlezer length 65536 yields a bit error rate(BER) and of 10^-5 at 0.9 dB and 1.4dB away from the Shannon limit by optimal (APP) and low-cost sub-optimal(MLA) decoders,respectively. 相似文献
15.
The global classroom is an emerging technology-based pedagogy used internationally by educational institutions. To evaluate a global classroom, we conducted a qualitative study using written reflections and semi-structured interviews of global classroom participants, based on two theoretical frameworks: Kearsley and Shneiderman’s engagement theory and Kolb’s experiential learning theory. We analyzed student reflections and transcribed interviews, using the software package, NVivo, with two objectives: (1) to evaluate if global classroom is engaging and experiential to students and (2) to elucidate how student engagement is fostered in the global classroom through experiential learning. Results illustrated a complex relationship between student engagement and experiential learning. During the experiential learning cycle, engagement theory (relate-create-donate) principles contributed to student engagement at varying levels and for different purposes. Based on the results of this study, we created a framework that demonstrates the interactivity of engagement theory and experiential learning theory to describe how student engagement featured in experiential learning during this global classroom, with strategies to maximize student engagement in experiential learning. 相似文献
16.
利用MATLAB对Henon系统的动力学行为的演变进行仿真与分析.通过对时域图、相图、功率谱和分岔图的分析,表明Henon系统可通过阵发性途径走向混沌,其间歇性与霍夫分岔和倍周期分岔密切相关. 相似文献
17.
在遗传算法中一个关键问题是必须采取措施保持种群多样性，防止算法出现早熟收敛。本文提出了一种基于父个体相似度的自适应遗传算法，使用新的自适应遗传操作策略以保持种群多样性。将新算法用于求解图的度约束最小生成树问题，实验结果表明本方法到比不使用父个体相似度信息的普通遗传算法权值更低的度约束最小生成树。 相似文献
18.
考虑了一类永磁同步电动机的终端滑模控制器设计问题.在控制器设计中利用中继切换控制使系统在给定的当前控制律的作用下运行到某一特定状态（或某一特定区域）后,控制律被切换到有限时间收敛的终端滑模控制器,使得系统在有限时间内达到平衡状态.终端滑模控制器的设计保证了闭环系统所有信号的有界性和平衡点的全局稳定性,以及系统在有限时间内精确地跟踪给定的参考信号.最后,通过一个数值仿真验证了所提算法的正确有效性. 相似文献
19.
社会总用电量预报是电力系统的重要工作之一,社会总用电量为非线性时间序列．针对电力系统负荷的复杂性及非线性,提出了结合混沌理论的思想,充分利用数据信息,在重构电力负荷相空间的基础上运用混沌全域法对负荷进行预测,并与最小二乘法预测模型预测结果进行比较,结果显示混沌全域法预测结果明显优于最小二乘法预测模型,预测精度也满足工程应用． 相似文献