区域旅游规划中旅游资源集合区生态位的研究

旅游资源单体的结合与分散直接决定着区域旅游规划的定位。本文剖析旅游资源实体聚合与分散的特征,诠释了旅游资源集合区的内涵与外延,运用生态位理论探讨了旅游资源集合区在区域旅游规划中的地位和作用,并以浙江省为例对区域旅游规划中旅游资源集合区的生态位进行了研究,以期为区域旅游规划中对旅游资源的多角度认识提供参考。     

SNM视角下新型研发机构发展质量提升路径与策略

针对当前不少新型研发机构创新效率不高、创新效果不大等发展瓶颈, 基于SNM(Strategic Niche Management)理论, 从愿景建立、技术选择、网络构建、成果转化和交互学习等5个维度设计了新型研发机构发展质量的提升路径, 进而通过凝练国际高水平研发机构的成功做法, 给出提升新型研发机构高质量发展的策略建议, 旨在为我国新型研发机构的提质增效提供崭新视角和参考借鉴。     

基于粒子群优化算法的电网GIC-Q多目标优化策略

地磁感应电流(GIC)流经变压器绕组会产生直流偏磁现象,造成变压器无功损耗增加,破坏电网无功平衡,影响电网安全稳定运行。为了有效地抑制GIC对电网的不良影响,以无功补偿设备成本和电压偏移量最小为目标,提出一种基于粒子群优化算法的多目标无功优化策略,保证地磁场扰动下电网无功平衡。所提策略利用小生境共享机制不断更新粒子位置,并依据拥挤距离排序对Pareto最优解进行存档,保持解的多样性和均匀性;引入混沌变异避免陷入局部最优解,同时提高全局搜索能力。GIC标准算例的仿真结果验证了所提策略的准确性和有效性。     

基于隔离小生境粒子群算法的APF优化配置

随着非线性负载的广泛应用,传统负荷端分散的谐波治理方式弊端渐显。以中小型电网中有源电力滤波器的集中补偿配置为目标,设计一种基于隔离小生境粒子群算法的APF优化配置方法。建立了有源电力滤波器的优化配置数学模型,以节点电压畸变率均方根为目标函数,并使用罚函数处理约束条件。改进后的粒子群算法兼顾全局与局部寻优能力,避免陷入局部最优点。在阐述所提优化配置方法流程的基础上,IEEE算例分析表明该配置方法可以同时进行APF位置和容量的寻优,治理后系统各节点总谐波电压畸变率小于4%,谐波附加损耗降低90%以上,实现对单、多谐波源系统电能质量的有效治理。     

山东半岛蓝色经济区旅游空间结构研究——基于生态位理论

合理的区域旅游空间结构可以促进区域旅游业的发展。为了充分利用山东半岛蓝色经济区丰富的旅游资源,促进区域旅游的可持续发展,文章在分析了山东半岛蓝色经济区旅游资源、旅游业现状及旅游交通状况的基础上,运用生态位理论,对山东半岛蓝色经济区的旅游城市进行生态位评价,并根据结果构建了以两个特色旅游区为主的旅游空间结构体系。     

使用特征点与灰度值的医学图像局部配准方法

针对医学图像配准中,存在某些图像间大部分区域没有差异或者存在差异但不被关心的情况,提出了一种局部图像配准方法。该方法使用局部可控的紧支撑径向基函数作为配准变换函数,通过在感兴趣区域设置特征点,将变换函数作用范围限制在图像中某一特定区域,保持其他区域不发生变形。利用图像间的互信息量作为测度函数,更加精确地求解变换函数。在优化策略的选择中,将图像配准看作为寻优过程,采用基于小生境的遗传算法优化变换函数参数,能够克服经典遗传算法早熟、搜索能力差等缺点。通过对已知变换函数的仿真图像与真实医学图像进行实验,结果表明该算法能够准确地找到较优的变换函数,并且将作用区域限制在较小范围内。该方法结合了基于特征点和基于像素配准方法的优点,有效的搜索策略保证了变换函数准确性,是一种可行的、鲁棒的局部医学图像配准方法。     

基于小生境遗传算法的粗糙集属性约简方法

针对遗传算法在全局优化问题中出现的早熟和收敛速度慢的问题,提出一种基于小生境遗传算法的粗糙集属性约简算法,采用基于淘汰相似结构机制的小生境技术,通过引入罚函数的方法调整个体的适应度,提高全局搜索能力。实验证明该算法是有效的,并能求解出信息系统中多组不同的最小约简,为决策支持和数据挖掘等提供更多信息。     

基于小生境免疫遗传算法的硅钢片优化排样

提出一种基于小生境免疫遗传算法的多级序列优化方法,并解决硅钢片优化排样问题。以免疫算法为基础,通过遗传算法进化抗体群,利用小生境技术保持抗体群的多样性。遗传算子和免疫记忆策略加快了优良个体的产生,提高了算法的收敛速度。共享机制和克隆抑制策略提高了算法的全局搜索能力,有效地避免早熟收敛现象。实际生产数据排样结果表明,该算法是有效、可行的。     

Comparative Genomics of the Extreme Acidophile Acidithiobacillus thiooxidans Reveals Intraspecific Divergence and Niche Adaptation

Acidithiobacillus thiooxidans known for its ubiquity in diverse acidic and sulfur-bearing environments worldwide was used as the research subject in this study. To explore the genomic fluidity and intraspecific diversity of Acidithiobacillus thiooxidans (A. thiooxidans) species, comparative genomics based on nine draft genomes was performed. Phylogenomic scrutiny provided first insights into the multiple groupings of these strains, suggesting that genetic diversity might be potentially correlated with their geographic distribution as well as geochemical conditions. While these strains shared a large number of common genes, they displayed differences in gene content. Functional assignment indicated that the core genome was essential for microbial basic activities such as energy acquisition and uptake of nutrients, whereas the accessory genome was thought to be involved in niche adaptation. Comprehensive analysis of their predicted central metabolism revealed that few differences were observed among these strains. Further analyses showed evidences of relevance between environmental conditions and genomic diversification. Furthermore, a diverse pool of mobile genetic elements including insertion sequences and genomic islands in all A. thiooxidans strains probably demonstrated the frequent genetic flow (such as lateral gene transfer) in the extremely acidic environments. From another perspective, these elements might endow A. thiooxidans species with capacities to withstand the chemical constraints of their natural habitats. Taken together, our findings bring some valuable data to better understand the genomic diversity and econiche adaptation within A. thiooxidans strains.     

An integrated approach to untangling mediated connectedness with online and mobile media

With the growth and convergence of mobile and social computing technology, mobile media are accorded new social meaning manifested in different aspects of our everyday life. This paper employs multiple theoretical frameworks—including the theory of the niche, the framework of media repertoires, and the communication infrastructure model—to examine individual-technology relationship as manifested through media repertoires and media connectedness. It argues that individuals tend to construct a set of media options and build connectedness with media technologies by engaging in a wide scope of activities through these media. In turn, this media repertoire and media connectedness may facilitate the performance of social and cultural practices in the public space. To investigate this conceptualization empirically, this study conducted a secondary analysis of data collected by the Pew Research Center in the United States. The results showed that multidimensional use of mobile apps was predicted by multidimensional Internet use, along with the scope of regular apps used and monetary investment by users. Additionally, multidimensional Internet use and the use of media repertoires consisting of mobile media and social media for socio-cultural activities facilitate public socio-cultural engagement. These results bring to light a new way of understanding how humans appropriate multiple types of technologies for activities in everyday life.