基于数据包络分析的乙烯能效分析系统

乙烯工业是石油化工中的核心也是高耗能行业,评价乙烯企业的用能水平是实现节能降耗的基础.本文针对乙烯企业的能效分析问题,基于数据包络分析(DEA),提出了一种面向整厂级别的能效分析方法.该方法综合乙烯生产的各项投入产出计算其能效.并基于该方法利用Matlab Web Server构建了B/S架构的乙烯能效分析系统,实现了多个乙烯企业横向及纵向的能效分析,为企业了解其能效水平及趋势提供了参考依据.     

Improving energy efficiency for flash memory based embedded applications

The JFFS2 file system for flash memory compresses files before actually writing them into flash memory. Because of this, multimedia files, for instance, which are already compressed in the application level go through an unnecessary and time-consuming compression stage and cause energy waste. Also, when reading such multimedia files, the default use of disk cache results in unnecessary main memory access, hence an energy waste, due to the low cache hit ratio. This paper presents two techniques to reduce the energy consumption of the JFFS2 flash file system for power-aware applications. One is to avoid data compression selectively when writing files, and the other is to bypass the page caching when reading sequential files. The modified file system is implemented on a PDA running Linux and the experiment results show that the proposed mechanism effectively reduces the overall energy consumption when accessing continuous and large files.     

Contextual patterns in mobile service usage

Mobile services differ from other services because of their temporal and spatial attributes. Mobile services additionally differ from each other in their value-added to the end-user. Some services—such as emailing and voice—are more business oriented. On the other hand, various free-time oriented services are provided in new smartphones, such as imaging and music playback. The present paper studies how mobile services are used in different contexts. For this, the paper develops a specialized algorithm that can be used with handset-based usage data acquired straight from end-users in an established panel study process. Educated guesses can be drawn on the user context based on the developed algorithm. In the present exercise usage contexts were divided into home, office and “on the move”. The algorithm is used with exemplary data from Finland and the UK covering 324 consumers in 2006. More than 70% of contextual use cases are correctly classified based on raw data. According to exemplary results particularly multimedia services are used “on the move”, whereas legacy mobile services experience more evenly distributed usage across all contexts. The algorithm that identifies context based on raw data provides a new angle to mobile end-user research. In the future, the accuracy of the algorithm will be improved with the integration of seamless cell-id logging and GPS data.     

Design patterns for user interface for mobile applications

The topic of this paper is a collection of user interface (UI) design patterns for mobile applications. In the paper we present the structure of the patterns collection – the patterns are suggested solutions to problems that are grouped into a set of problem areas that are further grouped into three main problem areas – a structure which is valuable both as an index to identifying patterns to use, and it gives a fairly comprehensive overview of issues when designing user interfaces for mobile applications. To show the breadth of the patterns collection we present six individual problems with connected design patterns in some detail – each coming from different problem areas. They represent important and relevant problems, and are on different levels of abstraction, thus showing how patterns may be used to present problems and solutions on different levels of detail. To show the relevance and usefulness of the patterns collection for usability professionals with a mixed background, we present some relevant findings from a validation of the patterns collection. In addition to verifying the relevance and usefulness of the patterns collection, it also shows both expected and surprising correlations between background and perceived relevance and usefulness. One important finding from the validation is an indication that the patterns collection is best suited for experienced UI developers wanting to start developing mobile UIs. Using a patterns collection for documenting design knowledge and experience has been a mixed experience, so we discuss pros and cons of this. Finally, we present related work and future research.     

基于高能效及公平性的移动设备定位算法

通过分析校园师生基于GPS的真实活动轨迹,以及何种算法才最适合具有自私性的移动用户展开合作,提出一种高能效及用户公平定位技术.通过采用代理设备合作思想,提出一种集中式最优算法,在保证固定精度界限和设备公平的基础上,实现移动设备GPS时间平均功率最小化.通过控制退避时间和GPS关闭时间,提出一种分布式准最优算法.最后,基于多种拓扑结构进行全面的仿真实验,验证了算法的高能效性和公平性.     

Implementing home energy management system with UPnP and mobile applications

The power grid is undergoing a revolution and modernization through integrating information and communication technologies with the power system and also installing new electricity system technologies. Distributed controls in a certain self-reliant power-service area are critical means to modernize the power system to be the Smart Grid. Since the self-reliant area is assumed to perform physical and/or expert-engineered operations that should be integrated, monitored and controlled by a computational cyber system, the area is one area where the cyber and physical systems interact together, and home in the Smart Grid is one example for the area. In this paper, we propose a home energy management system (HEMS) to realize full automation combining computational and physical systems in a home area, which excludes operator-based control and management. The proposed system is designed to be built on the Universal Plug-and-Play architecture, and it can be accessed remotely over the Internet via mobile applications that work in Apple iPhone. Based on the design, we actually implemented the HEMS and constructed an empirical testbed that consists of networked personal computers, home appliances, and portable wireless devices. With the empirical testbed, we verified the monitoring and controlling functions of the HEMS. Additionally we carried out an extensive simulation study with the measured data of power consumption and the collected data of power price in order to see the effectiveness of the proposed HEMS. We also discuss about some limitations and challenges that we have encountered in designing and implementing the HEMS.     

Improving the efficiency and reliability of wearable based mobile eHealth applications

In this paper we address the support of wearable mHealth applications in LTE and future 5G networks following a holistic approach that spans across the elements of a mobile network. The communication requirements change from one application to another so we propose a measurement methodology to facilitate the selection of the user equipment to fulfil these requirements. We also discuss a new network architecture to support traffic prioritization, RAN programmability, low latency and group communications to over-the-top applications. Our proposal is validated using several realistic experimentation platforms and the results show that mHealth systems can benefit from our approach.     

Energy efficiency on location based applications in mobile cloud computing: a survey

The constrained battery power of mobile devices poses a serious impact on user experience. As an increasingly prevalent type of applications in mobile cloud environments, location-based applications (LBAs) present some inherent limitations concerning energy. For example, the Global Positioning System based positioning mechanism is well-known for its extremely power-hungry attribute. Due to the severity of the issue, considerable researches have focused on energy-efficient locating sensing mechanism in the last a few years. In this paper, we provide a comprehensive survey of recent work on low-power design of LBAs. An overview of LBAs and different locating sensing technologies used today are introduced. Methods for energy saving with existing locating technologies are investigated. Reductions of location updating queries and simplifications of trajectory data are also mentioned. Moreover, we discuss cloud-based schemes in detail which try to develop new energy-efficient locating technologies by leveraging the cloud capabilities of storage, computation and sharing. Finally, we conclude the survey and discuss the future research directions.     

一种基于移动Internet的实时Email系统

简要介绍移动Ｉｎｔｅｒｎｅｔ和传统Ｅｍａｉｌ技术,描述了构造一个ＷＡＰ应用模型的实现并展望它的未来。     

An energy-efficient task migration scheme based on genetic algorithms for mobile applications in CloneCloud

The Journal of Supercomputing - The limitations of mobile devices have attracted researchers to work out an energy-efficient mechanism to enhance user experience. The emerging mobile cloud...     

An energy efficiency semi-static routing algorithm for WSNs based on HAC clustering method

In Wireless Sensor Networks (WSNs), energy efficiency is one of the most important factors influencing the networks’ performance. Through a well designed routing algorithm, WSNs’ energy efficiency can be improved evidently. Among various routing algorithms, hierarchical routing algorithms have advantages in improving nets’ robustness and flexibility, and it is more appropriate for large scale of networks. In this paper, some typical hierarchical routing algorithms are introduced, and their advantages and defects are analyzed. Based on these analyses, a new hierarchical routing algorithm with high energy efficiency named EESSC is proposed which is based on the improved HAC clustering approach. In EESSC, the sensor nodes’ residual energy would be taken into account in clustering operation, and a special packet head is defined to help update nodes’ energy information when transmitting message among the nodes. When the clusters have been formed, the nodes in cluster would be arrayed in a list and cluster head would be rotated automatically by the order of list. And a re-cluster mechanism is designed to dynamic adjust the result of clustering to make sensor nodes organization more reasonable. At last, EESSC is compared to other typical hierarchical routing algorithms in a series of experiments, and the experiments’ result which proves that EESSC has obviously improved the WSNs’ energy efficiency has been analyzed.     

An energy efficient FPGA partial reconfiguration based micro-architectural technique for IoT applications

Low power consumption and high computational performance are two important processor design goals for IoT applications. Achieving both design goals in one processor architecture is challenging due to their conflicting requirements. This paper introduces a reconfigurable micro-architectural level technique that allows a Reduced Instruction Set Computing (RISC) processor to support IoT applications with different performance and energy trade-off requirements. The processor can be reconfigured into either multi-cycle execution mode (low computational speed with low dynamic power consumption) or pipeline execution mode (high computational speed at the expense of high dynamic power), based on dynamic workload characteristics in IoT applications. Switching between modes is accomplished by exploiting the partial reconfiguration (PR) feature offered by the recent advancements in modern FPGAs. A RISC processor was designed based on the proposed micro-architectural level technique and implemented on FPGA as IoT sensor node. Experimental results demonstrate that the proposed technique with reconfigurable micro-architecture is able to significantly reduce the dynamic energy consumption, compared to conventional multi-cycle and pipeline only micro-architectures, while allowing better performance-energy trade-off in IoT applications.     

An optimized modular neural network controller based on environment classification and selective sensor usage for mobile robot reactive navigation

A new approach to the design of a neural network (NN) based navigator is proposed in which the mobile robot travels to a pre-defined goal position safely and efficiently without any prior map of the environment. This navigator can be optimized for any user-defined objective function through the use of an evolutionary algorithm. The motivation of this research is to develop an efficient methodology for general goal-directed navigation in generic indoor environments as opposed to learning specialized primitive behaviors in a limited environment. To this end, a modular NN has been employed to achieve the necessary generalization capability across a variety of indoor environments. Herein, each NN module takes charge of navigating in a specialized local environment, which is the result of decomposing the whole path into a sequence of local paths through clustering of all the possible environments. We verify the efficacy of the proposed algorithm over a variety of both simulated and real unstructured indoor environments using our autonomous mobile robot platform.     

Robust passive autofocus system for mobile phone camera applications

A robust autofocus system is a ubiquitous function in today’s mobile phone camera applications. However, due to the power consumption and size requirements, it is difficult for the autofocus function to be implemented into the design of mobile phone cameras. This paper presents a passive autofocus system with low computational complexity. This system uses a novel contrast measurement to determine degree of image sharpness, which can better reflect the information about image discontinuities. In order to gauge the performance of this measurement, a modified peak search strategy is used in the experiments. The experimental results from several typical image sequences validate the effectiveness of the proposed method.     

CARISMA: context-aware reflective middleware system for mobile applications

Mobile devices, such as mobile phones and personal digital assistants, have gained wide-spread popularity. These devices will increasingly be networked, thus enabling the construction of distributed applications that have to adapt to changes in context, such as variations in network bandwidth, battery power, connectivity, reachability of services and hosts, etc. In this paper, we describe CARISMA, a mobile computing middleware which exploits the principle of reflection to enhance the construction of adaptive and context-aware mobile applications. The middleware provides software engineers with primitives to describe how context changes should be handled using policies. These policies may conflict. We classify the different types of conflicts that may arise in mobile computing and argue that conflicts cannot be resolved statically at the time applications are designed, but, rather, need to be resolved at execution time. We demonstrate a method by which policy conflicts can be handled; this method uses a microeconomic approach that relies on a particular type of sealed-bid auction. We describe how this method is implemented in the CARISMA middleware architecture and sketch a distributed context-aware application for mobile devices to illustrate how the method works in practice. We show, by way of a systematic performance evaluation, that conflict resolution does not imply undue overheads, before comparing our research to related work and concluding the paper.     

Dual antenna system for metal frame mobile phone applications

A dual antenna system with 77 mm × 10 mm × 7.5 mm for metal frame (MF) LTE/GPS mobile phones is proposed and studied. The antenna proposed in this study comprises two antenna elements (Ant 1 and Ant 2) and a decoupling line. Ant 1 as the main antenna that covers the lower band (698‐960 MHz), the GPS band, and the higher band (1710‐2690 MHz) consisting of a ground branch, a coupled line, and a tuning line. Ant 2 as the auxiliary antenna that covers the higher band consisting of a monopole branch and a match circuit. Ant 1 and Ant 2 form a two‐element MIMO antenna covering the higher band. The advantages of the proposed antenna are that the main antenna (Ant 1) covers the GPS band and all of the 2G/3G/4G bands, and the two‐element MIMO antenna covering the higher band, which consists of Ant 1 and Ant 2 located at the same side of a mobile phone with an MF, is obtained. A prototype is manufactured and tested. For Ant 1, the measured working bands (under ?6 dB condition) are 685 to 965 MHz and 1480 to 2800 MHz, and the LTE700, GSM850, GSM900, GPS, GSM1800, GSM1900, UMTS, LTE2300, and LTE2500 bands are covered. For Ant 2, the measured working band (under ?6 dB condition) is 1640 to 2720 MHz, and the GSM1800, GSM1900, UMTS, LTE2300, and LTE2500 bands are covered. The measured isolations between Ant 1 and Ant 2 are larger than 12 dB at the working bands. The measured efficiencies, envelope correlation coefficients, and mean effective gains are also presented.     

An efficient model-based methodology for developing device-independent mobile applications

Current methodologies for developing mobile applications are mostly based on the application programming interfaces (APIs) offered by the native platform. Hence, most solutions are characterized by a low portability and/or reusability. In this paper, we propose a novel methodology based on a declarative and device-independent approach for developing event-driven mobile applications. The methodology relies on: (i) an abstract mobile device based on the user interface markup language; (ii) a content adaptation mechanism based on user preferences; (iii) a context adaptation mechanism based on a standardized context of delivery; (iv) a uniform set of client-side APIs based on an interface object model; (v) an efficient transformational model.More specifically, in the design phase, the application is modeled as platform-independent on the abstract mobile device. In the execution phase, the application is automatically tailored to the specific platform on the basis of the content and context adaptation mechanisms. We describe the analysis, design and implementation of a framework, called MODIF, which supports the proposed methodology, and show its application to the development of both business and consumer real-world applications on Apple iPhone? and Google Android? mobile devices. Finally, we discuss how the experience of using MODIF highlights the quality of the methodology in terms of automation of the lifecycle, expressiveness and readability of the representation, efficiency of the compilation/interpretation, fast learning curve and predictability.