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1.

Music categorization based on acoustic features extracted from music clips and user-defined tags forms the basis of recent music recommendation applications, because relevant tags can be automatically assigned based on the feature values and their relation to tags. In practice, especially for handheld lightweight mobile devices, there is a certain limitation on the computational capacity, owing to consumers’ usage behavior or battery consumption. This also limits the maximum number of acoustic features to be extracted, and results in the necessity of identifying a compact feature subset that is used for the music categorization process. In this study, we propose an approach to compact feature subset-based multi-label music categorization for mobile music recommendation services. Experimental results using various multi-labeled music datasets reveal that the proposed approach yields better performance when compared to conventional approach.

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2.

In a wireless networked control system (W-NCS), energy is required to transmit a sensor reading to the controller. It should be noted that the packet success rate (PSR) is an essential factor in the control performance, and PSR is directly proportional to the energy per symbol. Hence, it requires a significant amount of energy to have perfect control performance. However, in most cases in wireless sensor network scenarios, each node is attached to a limited power battery. Therefore, an energy optimization scheme that can harvest energy while maintaining the control performance is essentially required. The combination of Kalman filter and Linear Quadratic Regulator (LQR) that is known as Linear Quadratic Gaussian (LQG) is used as the backbone of the scheme to estimate the state and synthesize the optimal control. In addition, the optimal power scheduler (PS) is introduced to minimize energy usage while maintaining control performance. The finite block length approach is applied to achieve the upper bound of packet error rate. The results of energy consumption optimization showed that the scheme worked perfectly, wherein the energy per symbol usage is low, and the stability of the dynamic system is well maintained.

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3.

With the popularity of mobile devices, the next generation of mobile networks has faced several challenges. Different applications have been emerged, with different requirements. Offering an infrastructure that meets different types of applications with specific requirements is one of these issues. In addition, due to user mobility, the traffic generated by the mobile devices in a specific location is not constant, making it difficult to reach the optimal resource allocation. In this context, network function virtualization (NFV) can be used to deploy the telecommunication stacks as virtual functions running on commodity hardware to meet users’ requirements such as performance and availability. However, the deployment of virtual functions can be a complex task. To select the best placement strategy that reduces the resource usage, at the same time keeps the performance and availability of network functions is a complex task, already proven to be an NP-hard problem. Therefore, in this paper, we formulate the NFV placement as a multi-objective problem, where the risk associated with the placement and energy consumption are taken into consideration. We propose the usage of two optimization algorithms, NSGA-II and GDE3, to solve this problem. These algorithms were taken into consideration because both work with multi-objective problems and present good performance. We consider a triathlon circuit scenario based on real data from the Ironman route as an use case to evaluate and compare the algorithms. The results show that GDE3 is able to attend both objectives (minimize failure and minimize energy consumption), while the NSGA-II prioritizes energy consumption.

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4.
The increasing number of mobile devices with ever‐growing capabilities makes them useful for running scientific applications. However, these applications have high computational demands, whereas mobile devices have limited capabilities when compared with non‐mobile devices. More importantly, mobile devices rely on batteries for their power supply. We initially measure the battery consumption of different versions of known micro‐benchmarks representing common programming primitives found in scientific applications. Then, we analyze the performance of such micro‐benchmarks in CPU‐intensive mobile applications. We apply good programming practices and code refactorings to reduce battery consumption of scientific mobile applications. Our results show the reduction in energy usage from applying these refactorings to three scientific applications, and we consequently propose guidelines for high‐performance computing applications. Our focus is on Android, the dominant mobile operating system. As a long‐term contribution, our results represent one more step in the progress towards hybrid distributed infrastructures comprising fixed and mobile nodes, that is, the so‐called mobile grids. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

5.

The adoption and popularization of mobile devices, such as smartphones and tablets, accentuated after the second decade of this century, has been motivated by the growing number of mobile applications, which can solve problems in different areas of contemporary societies. Conversely, the software development industry is motivated by the increasing number and quality of resources that mobile devices possess nowadays (e.g., memory, sensors, processing power or battery). While powerful mobile devices do exist, one of the main driving factors behind the increase of resources is the usage of Cloud technology, which strongly complement mobile computing. As expected, the adoption of measures to mitigate security issues has not accompanied the growth and speed of development for Cloud and Mobile software, to ensure that these are resilient to attacks by design. Aiming to contribute to decrease the gap between software and security engineering, this paper presents a deep approach to attack taxonomy, security mechanisms, and security test specification for the Cloud and Mobile ecosystem of applications. This is also the first time an encompassing and conjoined approach is provided for attack taxonomy and specification of security tests automation tools for this ecosystem.

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6.
Mobile computing devices have improved substantially. Such a development fosters the usage of those devices for various purposes, including health care as a prominent example. Mobile health (mHealth) is a subfield of electronic health (eHealth) that refers to the practice of medicine and public health supported by mobile devices. A specific concern for mHealth is the limitation of power supply for the mobile devices, since interruptions on power supply can result in critical situations. This paper proposes analytical models to identify the mean time of one life cycle of the battery, and thus identify the average battery lifetime considering some device utilization characteristics. We evaluate the impact of both network connectivity (local and wide areas) and communication protocols (Polling, Long polling, WebSockets, and XMPP) on the discharging rate, and subsequently on the lifetime of batteries with different power capacities. We observed a noteworthy impact of these factors on battery usage and, thus, on mHealth applications. We use a hierarchical modeling approach that enables efficient representation of system complexity and provides accurate results for planning the autonomy of mobile devices in an mHealth context.  相似文献   

7.

Mobile cloud computing is a form of cloud computing that incorporates mobile devices such as smartphones and tablet PCs into the cloud infrastructure. As mobile devices are resource-constrained in nature, new scheduling strategies are required when using them as resource providers. Based on our previous group-based scheduling algorithm, we present fault-tolerant scheduling algorithms considering checkpoint and replication mechanisms to actively cope with faults. We carried out the performance evaluation with simulation to demonstrate that our algorithm is more efficient than the existing one lacking fault tolerance in terms of accuracy rate, resource consumption, and average execution time. In particular, the average execution time was reduced by about 60%, resulting in the reduction of resource consumption.

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8.

Organic light-emitting diode (OLED) displays have a high power efficiency; however, the frequent use of user interaction-based applications such as instant messengers, video players, and games contributes strongly to the total power consumption. The power consumption varies significantly depending on the display contents, and thus, color transformation, which is a representative low-power technique, is used for OLED displays. Previously developed low-power color transformation methods have not been thoroughly researched for satisfying the human visual system and have not considered optimal visual satisfaction and power consumption simultaneously. In this paper, a novel low-power color transformation approach is proposed, which is aimed at simultaneously optimizing both visual satisfaction and power consumption. In addition, it is implemented on an active-matrix OLED (AMOLED) display-based Android smartphone at runtime. Experimental results show that the proposed technique achieves better human visual satisfaction and shows up to 22.32% power saving on average on the AMOLED display and offers 6.23% more extended battery life over that of an existing leading technique.

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9.

In recent years, Fog Computing (FC) is known as a good infrastructure for the Internet of Things (IoT). Using this architecture for the mobile applications in the IoT is named the Mobile Fog Computing (MFC). If we assume that an application includes some modules, thus, these modules can be sent to the Fog or Cloud layer because of the resource limitation or increased runtime at the mobile. This increases the efficiency of the whole system. As data is entered sequentially, and the input is given to the modules, the number of executable modules increases. So, this research is conducted to find the best place in order to run the modules that can be on the mobile, Fog, or Cloud. According to the proposed method, when the modules arrive at gateway, then, a Hidden Markov model Auto-scaling Offloading (HMAO) finds the best destination to execute the module to create a compromise between the energy consumption and execution time of the modules. The evaluation results obtained regarding the parameters of the energy consumption, execution cost, delay, and network resource usage shows that the proposed method on average is better than the local execution, First-Fit (FF), and Q-learning based method.

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10.
针对移动边缘计算环境下,移动设备的计算、续航、存储能力的不足,导致其响应延迟、电池寿命降低等问题,设计了一种动态节能资源竞争计算卸载(DERCO)策略。该策略综合考虑了信道容量以及设备间的相互干扰等情况,以一种贪婪算法的思想,让所有边缘设备通过迭代竞争信道资源,节能效果最好的设备将获得卸载机会,再利用一次性卸载方法,根据实时的信道状况和卸载速率进行动态的细粒度子任务卸载决策。实验结果表明,该策略优于一种近似协同计算卸载方案,有效降低了设备的能耗与时延。  相似文献   

11.

Todays, XML as a de facto standard is used to broadcast data over mobile wireless networks. In these networks, mobile clients send their XML queries over a wireless broadcast channel and recieve their desired XML data from the channel. However, downloading the whole XML data by a mobile device is a challenge since the mobile devices used by clients are small battery powered devices with limited resources. To meet this challenge, the XML data should be indexed in such a way that the desired XML data can be found easily and only such data can be downloaded instead of the whole XML data by the mobile clients. Several indexing methods are proposed to selectively access the XML data over an XML stream. However, the existing indexing methods cause an increase in the size of XML stream by including some extra information over the XML stream. In this paper, a new XML stream structure is proposed to disseminate the XML data over a broadcast channel by grouping and summarizing the structural information of XML nodes. By summarizing such information, the size of XML stream can be reduced and therefore, the latency of retrieving the desired XML data over a wirless broadcast channel can be reduced. The proposed XML stream structure also contains indexes in order to skip from the irrelevant parts over the XML stream. It therefore can reduce the energy consumption of mobile devices in downloading the results of XML queries. In addition, our proposed XML stream structure can process different types of XML queries and experimental results showed that it improves the performace of XML query processing over the XML data stream compared to the existing research works in terms of access and tuning times.

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12.
Battery management of mobile robots is an issue that has not been a strong focus of attention and is usually addressed by the simple use of battery thresholds. One of the main causes is that no significant method of assessment of risk of battery depletion has yet been proposed. As a result decision of redirection to a charging station is fixed and takes into account neither a dynamic evaluation of the risk of battery depletion nor an evaluation of the gain, defined as the level of mission accomplishment that could be achieved. In this paper we propose a novel method for evaluation of risk of battery depletion for mobile robots. Uncertainties concerning effective battery capacity, current discharge rate and energy required for reaching the station are addressed by the use of probability density functions. This risk assessment will allow replacing the usage of battery threshold by a customizable risk-taking parameter that will be used to define what level of gain is required for balancing a given level of risk. This risk/gain management of battery will guarantee that decision of redirection to the station corresponds to a favorable compromise between risk and level of mission accomplishment. While the proposed approach has been tested using a simulated and real room cleaning robot, it could be applied on a wider range of mobile robots.  相似文献   

13.
Abstract

Cloud computing, the recently emerged revolution in IT industry, is empowered by virtualisation technology. In this paradigm, the user’s applications run over some virtual machines (VMs). The process of selecting proper physical machines to host these virtual machines is called virtual machine placement. It plays an important role on resource utilisation and power efficiency of cloud computing environment. In this paper, we propose an imperialist competitive-based algorithm for the virtual machine placement problem called ICA-VMPLC. The base optimisation algorithm is chosen to be ICA because of its ease in neighbourhood movement, good convergence rate and suitable terminology. The proposed algorithm investigates search space in a unique manner to efficiently obtain optimal placement solution that simultaneously minimises power consumption and total resource wastage. Its final solution performance is compared with several existing methods such as grouping genetic and ant colony-based algorithms as well as bin packing heuristic. The simulation results show that the proposed method is superior to other tested algorithms in terms of power consumption, resource wastage, CPU usage efficiency and memory usage efficiency.  相似文献   

14.
Mobile battery-operated devices are becoming an essential instrument for business, communication, and social interaction. In addition to the demand for an acceptable level of performance and a comprehensive set of features, users often desire extended battery lifetime. In fact, limited battery lifetime is one of the biggest obstacles facing the current utility and future growth of increasingly sophisticated “smart” mobile devices. This paper proposes a novel application-aware and user-interaction aware energy optimization middleware framework (AURA) for pervasive mobile devices. AURA optimizes CPU and screen backlight energy consumption while maintaining a minimum acceptable level of performance. The proposed framework employs a novel Bayesian application classifier and management strategies based on Markov Decision Processes and Q-Learning to achieve energy savings. Real-world user evaluation studies on Google Android based HTC Dream and Google Nexus One smartphones running the AURA framework demonstrate promising results, with up to 29% energy savings compared to the baseline device manager, and up to 5×savings over prior work on CPU and backlight energy co-optimization.  相似文献   

15.
娄柯  崔宝同李纹 《控制与决策》2013,28(11):1637-1642

针对移动传感器网络中的目标跟踪问题, 以及现有控制策略在保持网络拓扑结构连通性和降低能量消耗方面存在的不足, 提出一种基于蜂拥控制的移动传感器网络目标跟踪算法. 首先, 利用网络中部分节点检测目标, 并使用卡尔曼一致性滤波算法估计目标的状态, 在获得比较精确的估计状态的同时降低能量消耗; 然后, 在蜂拥控制下传感器网络始终保持拓扑结构连通性和目标对网络可见, 同时避免节点之间发生碰撞. 仿真结果验证了所提出算法的有效性.

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16.
Mobile cloud computing is a dynamic, virtually scalable and network based computing environment where mobile device acts as a thin client and applications run on remote cloud servers. Mobile cloud computing resources required by different users depend on their respective personalized applications. Therefore, efficient resource provisioning in mobile clouds is an important aspect that needs special attention in order to make the mobile cloud computing a highly optimized entity. This paper proposes an adaptive model for efficient resource provisioning in mobile clouds by predicting and storing resource usages in a two dimensional matrix termed as resource provisioning matrix. These resource provisioning matrices are further used by an independent authority to predict future required resources using artificial neural network. Independent authority also checks and verifies resource usage bill computed by cloud service provider using resource provisioning matrices. It provides cost computation reliability for mobile customers in mobile cloud environment. Proposed model is implemented on Hadoop using three different applications. Results indicate that proposed model provides better mobile cloud resources utilization as well as maintains quality of service for mobile customer. Proposed model increases battery life of mobile device and decreases data usage cost for mobile customer.  相似文献   

17.
马郓  刘譞哲  梅宏 《软件学报》2020,31(7):1980-1996
随着移动互联网的飞速发展,用户越来越多地通过移动设备访问Web应用.浏览器为Web应用提供基本的计算、渲染等运行时支撑,其缓存机制可以支持Web应用直接从本地而不是通过网络来获取可复用资源,不仅能够减少整体的执行时间从而提升应用加载速度,还能够减少网络流量使用和电池电量消耗,从而保证移动Web用户体验.近年来,围绕面向移动Web应用的浏览器缓存优化得到了国内外学术界和工业界的广泛关注.然而,现有研究工作大多都是从网络层面关注浏览器缓存的整体性能,未充分考虑移动互联网用户访问行为的差异性和动态性,以及Web应用自身持续演化对浏览器实际缓存性能的影响.针对这一问题,首先设计了一种新型主动式缓存度量实验,通过仿真用户的访问行为来分析移动Web应用实际资源使用情况,揭示了浏览器缓存的理论性能上限和实际性能之间的巨大差距,并发现了造成这一差距的3个主要原因:重复请求别名资源、启发式过期时间和保守的过期时间配置.基于此发现,从应用层和平台层分别提出了两种浏览器缓存性能优化方案,并实现了原型系统.实验结果表明,采用两种方法分别平均可减少8%~51%和4%~58%的网络流量,且系统开销较小.  相似文献   

18.
荷电状态(SOC)是动力锂电池的重要参数.针对安时法估计锂电池SOC存在累积误差,其他估计算法复杂度较高的问题,提出一种工程实用的SOC估计方法.该方法通过分析电池特性并结合安时法,建立了SOC初始值、总容量和累积误差的校准方法.通过建立终端电压与SOC之间的映射关系,利用恒流、恒压不同充电阶段的电池特性,实现了电池系统在一个放电周期内的SOC高精度估计.实验表明,该方法能够使得SOC的估计误差在5%以内.  相似文献   

19.
ABSTRACT

This research investigated how mobile apps influence the dynamic capabilities of service sector micro and small enterprises (MSEs) in Lagos, Nigeria. Using an abductive method, data from 388 service sector MSEs was examined through exploratory factor analysis. The resultant model suggests that mobile app usage barely increases the absorptive capability (integrating new learning into the organization) of MSEs; rather, it strongly influences the ability to seize opportunities. The result implies that mobile app usage by service sector MSEs in Lagos deviates from the conventional views on the micro foundations of the dynamic capability framework, which argues that sensed opportunities are first analysed (shaped) before resources are deployed towards their maximization. These findings suggest that the service sector MSEs in Lagos seldom scrutinize opportunities before deploying resources to seize them. This study extends IS literature on how mobile apps help MSEs to exploit business opportunities in resource-constrained contexts.  相似文献   

20.
更长的飞行时间是四旋翼无人机领域研究热点方向之一;在对实际飞行中瞬时消耗电流和电池电压数据的研究中发现,过大姿态角下电池电量消耗显著提升;为了延长飞行时间和提升电池电量使用效率,提出一种长续航飞行模式;在该模式下,基于现有的角速度串级PID姿态控制器,将飞行加速度的控制算法改为飞行速度控制,限制过大姿态角的操作;在无风、微风和强风环境下的飞行实验表明,长续航飞行模式比传统飞行方式飞行时间增加8%~20%;长续航飞行模式可广泛应用于多种无需快速变换飞行路径,但需要更长飞行时间的的应用场景中。  相似文献   

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