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排序方式: 共有452条查询结果,搜索用时 15 毫秒
41.
A comprehensive approach to model and use context for adapting applications in pervasive environments 总被引:2,自引:0,他引:2
With an increasing diversity of pervasive computing devices integrated in our surroundings and an increasing mobility of users, it will be important for computer systems and applications to be context-aware. Lots of works have already been done in this direction on how to capture context data and how to carry it to the application. Among the remaining challenges are to create the intelligence to analyze the context information and deduce the meaning out of it, and to integrate it into adaptable applications. Our work focuses on these challenges by defining generic context storage and processing model and by studying its impact on the application core. We propose a reusable context ontology model that is based on two levels: a generic level and a domain specific level. We propose a generic adaptation framework to guarantee adaptation of applications to the context in a pervasive computing environment. We also introduce a comprehensive adaptation approach that involves content adaptation and presentation adaptation inline with the adaptation of the core services of applications. Our case study shows that the context model and the application adaptation strategies provide promising service architecture. 相似文献
42.
Ivan Tanev 《Genetic Programming and Evolvable Machines》2007,8(1):39-59
In this work we propose an approach for incorporating learning probabilistic context-sensitive grammar (LPCSG) in genetic
programming (GP), employed for evolution and adaptation of locomotion gaits of a simulated snake-like robot (Snakebot). Our
approach is derived from the original context-free grammar which usually expresses the syntax of genetic programs in canonical
GP. Empirically obtained results verify that employing LPCSG contributes to the improvement of computational effort of both
(i) the evolution of the fastest possible locomotion gaits for various fitness conditions and (ii) adaptation of these locomotion
gaits to challenging environment and degraded mechanical abilities of the Snakebot. 相似文献
43.
Agent-based simulation has been a popular technique in modeling and analyzing electricity markets in recent years. The main
objective of this paper is to study existing agent-based simulation packages for electricity markets. We first provide an
overview of electricity markets and briefly introduce the agent-based simulation technique. We then investigate several general-purpose
agent-based simulation tools. Next, we review four popular agent-based simulation packages developed for electricity markets
and several agent-based simulation models reported in the literature. We compare all the reviewed packages and models and
identify their common features and design issues. Based on the study, we describe an agent-based simulation framework for
electricity markets to facilitate the development of future models for electricity markets. 相似文献
44.
针对QoS管理模型中的自适应处理模块进行了深入研究,提出了基于用户的自适应类选择算法,该算法不仅能够提高用户的满意度,而且能够均衡各个服务类别在网络中的负荷,保证应用的服务质量,实现QoS管理的自适应性.算法采用了基于下一时刻的预测方法进行估算,从而优化了参数取值,使用户选择的服务类别更加精确. 相似文献
45.
《工程(英文)》2018,4(1):156-163
Sea level rise (SLR) is a major projected threat of climate change that is expected to affect developing coastal cities located in estuarine delta regions. Shanghai is one such city, being located in the Yangtze River Delta (YRD). It is difficult, however, for decision-makers to implement adaptation due to the uncertain causes, magnitudes, and timings of SLR behaviors. This paper attempts to map the causes and magnitudes of SLR behaviors on a decadal scale. We analyze the tidal level records from 11 tidal gauge stations and the corresponding bathymetry measurements around these stations since 1921. We identify three new SLR behaviors along the Shanghai coast due to anthropogenic geomorphologic changes (AGCs), besides the well-known eustatic sea level rise (ESLR), tectonic subsidence (TS), and urban land subsidence (ULS). The first new behavior is regional sea level rise (RSLR), which occurs as a result of land reclamation and deep waterway regulation. The second is regional sea level fall (RSLF), which occurs because the channel bed is eroded due to sediment supply decline in the river catchment. The last SLR behavior is local tidal datum rise (LTDR). Thus, we project that the magnitude of SLR for the Shanghai coast ranges from 10 cm to 16 cm from 2011 to 2030. Clarifying SLR behaviors is important to aid local decision-makers in planning structural and non-structural measures to combat escalating flood damage costs in an estuarine delta system; this field is full of future challenges. 相似文献
46.
A reflective infrastructure for workflow adaptability 总被引:15,自引:0,他引:15
We present a flexible framework that enables workflow systems to adapt to changing conditions. The model is designed to reveal key aspects of the tasks involved in representing and enacting business processes. These fundamental characteristics are identified as state, behaviour, distribution, coordination and enactment. By isolating such core concepts in a way that allows them to be varied, we open up the general process of task coordination and execution, allowing for extensions in a planned way. By suitable manipulation of each of these aspects, at the appropriate level, a workflow system may be extensively modified in a way that minimises the effect of such change upon other aspects of the system. 相似文献
47.
随着全球气候不断升温,城市高温
灾害越来越严重,严重影响城市人居环境。
通过CNKI和Web of Science检索城市高温
灾害相关文献,采用Met a-a na lysis方法和
CiteSpace工具,分析近年来城市规划应对高
温灾害的研究进展。结果发现,城市高温灾
害的规划应对研究起源于城市热岛方面,在
气候变化方面得到发展,最后形成城市高温
灾害的研究。在减缓性策略与适应性策略两
大主题下,主要应对途径是土地利用、空间
结构、道路交通、绿化景观以及建筑等,每种
途径又分为多种具体策略。目前在规划体系、
针对性规划以及效益评估等方面存在明显不
足。在理论上应加强构建规划体系,以及效
益评估系统的研究;在实践中制定应对高温
灾害的规划编制标准,探索气候友好型城市
规划设计方法,为韧性城市建设提供参考。 相似文献
48.
该文以山西省电力公司下属的几个中等职业学校的环境改造为例,阐述了近年来现代职业教育的发展对校园建筑及环境的时代要求,探讨了校园环境改造中可以采用的策略,并提出建立在建筑策划程序下的体现安全、经济的适应性改造手段和符合经济目标的策略选择。 相似文献
49.
Ant colony optimization was initially proposed for discrete search spaces while in continuous domains, discretization of the
search space has been widely practiced. Attempts for direct extension of ant algorithms to continuous decision spaces are
rapidly growing. This paper briefly reviews the central idea and mathematical representation of a recently proposed algorithm
for continuous domains followed by further improvements in order to make the algorithm adaptive and more efficient in locating
near optimal solutions. Performance of the proposed improved algorithm has been tested on few well-known benchmark problems
as well as a real-world water resource optimization problem. The comparison of the results obtained by the present method
with those of other ant-based algorithms emphasizes the robustness of the proposed algorithm in searching the continuous space
more efficiently as locating the closest, among other ant methods, to the global optimal solution. 相似文献
50.
未来移动通信将包含多种不同的无线网络存取技术与标准 ,移动终端如何运转在不同的无线网络系统下 ,如何使用不同的无线存取技术 ( UMTS,cdma2 0 0 0 ,GSM/GPRS,WLAN,WPAN等 ) ,这是本篇要考虑的问题。并提出了一个结构独立开放并有 Qo S保证的基于 All- IP的异构无线网漫游方案 相似文献