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为了满足异构网络热点区域覆盖,同时解决由于低功率基站在高功率基站覆盖区域随意分布而带来的小区间干扰及系统容量速率受限问题,提出了一种载波聚合系统的联合小区选择、载波选择和干扰对齐算法。该方法是在载波公平比例准则下,动态的选择成员载波。为了进一步降低小区间干扰,设计了新的基于干扰对齐的用户小区选择算法。理论分析表明,联合优化算法问题可以分解成三个子问题进行优化求解处理。仿真结果表明,与调度复用因子为1的参考算法相比,设计的方案由于联合了小区选择和载波选择使得用户选择低功率节点作为服务小区的机会增多,提高了低功率节点小区容量,使系统的吞吐量得到提高。 相似文献
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Zhi Qiao Meiyan Zhao Fang Wang Luo Liu 《International journal of remote sensing》2016,37(10):2433-2450
Forests account for more than 23% of China’s total area. As the most important terrestrial ecosystem, forests have tremendous ecological value. However, it remains difficult to classify forest subcategories at the national scale. In this study, a newly developed binary division procedure was used to categorize forest areas, including their spatiotemporal dynamics, during the period 2000–2010. Time-series images acquired using the Moderate Resolution Imaging Spectroradiometer (MODIS), together with auxiliary data on land use, climate zoning, and topography, were utilized. Hierarchical classification and zoning were combined with remote-sensing auto-classification. Based on the forest extent mask, the state-level forest system was divided into four classes and 18 subcategories. The method achieved an acceptable overall accuracy of 73.1%, based on a comparison to the sample points of China’s fourth forest general survey data set. In 2010, the total forest area was 1.755 × 106 km2, and the total area of and shrubs was 4.885 × 105 km2. The total area of woodland increased by 2536.25 km2 during the decade 2000–2010. The shrub subcategories exhibited almost no change during this time period; however, significant changes in forest area occurred in the mountainous region of Northeast China as well as in the hilly regions of Southern China. The main transformations took place in cold-temperate and temperate mountainous deciduous coniferous forest, subtropical deciduous coniferous forest, subtropical evergreen coniferous forest, and temperate and subtropical deciduous broadleaved mixed forests. The binary division procedure proposed herein can be used not only to rapidly classify more forest subcategories and monitor their dynamic changes, but also to improve the classification accuracy compared with global and national land-cover maps. 相似文献
958.
The shortage of water resources is a global issue. This study attempts to utilise eco-visualisation interface design to affect users’ water-usage behaviour. Three interface proposals were designed in this study: numeric, water droplet (abstract symbol), and swimming fish (animated image). These three different interface formats range from abstract to figurative and from neutral to affective. A total of 93 subjects were divided into three groups and randomly performed designated dishwashing tasks twice. One of the tasks was completed without the assistance of any interface, whereas the other involved applying one of the three interface formats with eco-visualisations. In this study, the Self-Assessment Manikin scales, the System Usability Scale, and the Questionnaires for User Interaction Satisfaction were used to measure the emotional dimensions and perceived usability and to record the differences in water usage volume. The results indicated that the emotional valence evoked by the animated image interface was significantly higher than that by the numeric interface. The effect of the numeric interface formats on the subjects focused on emotional arousal, whereas other interfaces emphasised emotional valence. With the aid of the eco-visualisations of interface design, the evoked emotional response and enhanced usability could help improve sustainable behaviours towards water saving. 相似文献
959.
As the population of elderly people in society rises, the importance of technology to assist health management is growing with the demographic shift. Wearable personal computing has been the common solution proposed by related projects to fulfil the needs of elderly people. These add-on devices are attached to the users, and result in uneasiness or discomfort while wearing them in public areas. In this study, three common wearing positions – wrist, upper arm, and neck – were investigated in terms of psychological perception and perceived readability. Twenty-four Taiwanese participants in Miaoli area were asked to wear the designed prototypes for a certain time. The participants completed questionnaires and participated in an open-ended interview. Data of psychological perceptions, visibility, and readability about wearable devices were collected. The results evidenced that the personal attributes of gender, smart device user, and requirement for medical care affect the psychological perception and user attitudes. The statistical results indicated significant differences in elderly people's attitudes towards wearable devices attached to different parts of the body. The wrist was the most favourable location to attach a wearable device. 相似文献
960.
图像分割是图像理解和计算机视觉的重要内容.针对单核SVM在进行图像分割过程中不能兼顾分割精度高和泛化性能好的问题,提出一种基于K均值聚类和优化多核SVM的图像分割算法.该算法首先运用K均值聚类算法自动选取训练样本,然后提取其颜色特征和纹理特征作为训练样本的特征属性,并使用其对构造的多核SVM分割模型进行训练,最后用粒子群优化算法对多核核参数、惩罚因子以及核权重系数联合寻优,使生成的多核SVM具有更好的分割性能.实验结果表明,本文方法在有效提取图像目标细节的同时,获得了更高的分割精度,与基于单核的SVM分割模型相比,具有更强的泛化能力. 相似文献