All‐Printed Porous Carbon Film for Electricity Generation from Evaporation‐Driven Water Flow

Converting environmental “waste energies” into electricity via a natural process is an ideal strategy for environmental energy harvesting and supplying power for distributed energy‐consuming devices. This paper reports that evaporation‐driven water flow within an all‐printed porous carbon film can reliably generate sustainable voltage up to 1 V with a power density of ≈8.1 µW cm^?3 under ambient conditions. The output performance of the device can be easily scaled up and used to power low‐power consumption electronic devices or for energy storage. Furthermore, the device is successfully used without electric storage as a direct power source for electrodeposition of silver microstructures. Because of the ubiquity of water evaporation in nature and the low cost of materials involved, the study presents a novel avenue to harvest ambient energy and has potential applications in low‐cost, green, self‐powered devices and systems.     

Energy-Harvesting Systems for Green Computing

Energy harvesting technologies provide a promising alternative to battery-powered systems and create an opportunity to achieve sustainable computing for the exploitation of ambient energy sources. However, energy harvesting devices and power generators encompass a number of non-classical system behaviors or characteristics, such as delivering nondeterministic power density, and these would create hindrance for effectively utilizing the harvested energy. Previously, we have investigated new design methods and tools that are used to enable power adaptive computing and, particularly, catering non-deterministic voltage, which can efficiently utilize ambient energy sources. Also, we developed a co-optimization approach to maximize the computational efficiency from the harvested ambient energy. This paper will provide a review of these methods. Emerging technologies, such as 3D-IC, which would also enable new paradigm of green and high-performance computing, will be also discussed.     

载频智能节电技术在TD-LTE通信网络中的应用

在移动通信网络的能耗中,基站的能耗超过了整个通信系统能耗的70%,为了能够实现移动运营商的节能目标,对于无线基站节能减耗技术的研究将是一个非常重要的方面。首先从移动通信基站节能的现状出发,分析了TD-LTE系统中基站主设备智能节电系统设计的必要性。在分析无线网络话务时间规律的基础上,针对移动通信网络话务潮汐的特点,根据TD-LTE系统基站主设备的运行原理,分析了载频关断技术在TD-LTE基站系统中实现节能降耗的方法,提出了载频智能关断技术在TD-LTE基站系统中设计原则和技术方案,并且通过测试验证得出了载频智能关断技术在TD-LTE网络中运行的可行性。最后,对此项技术规模性应用所取得的节能效果进行了总结并提出应用建议。     

云计算数据中心节能关键技术分析

随着经济的快速发展,各行各业对于信息化的运用越来越普遍,云计算作为信息化技术发展中的一部分,对云计算数据中心节能进行定量指标方面的分析和研究,并且针对云计算数据中心节能的一些关键性技术,即机房选址、IT设备选型、电源系统优化、制冷系统设计和应用场景的选择等进行详细的分析和研究.     

An energy‐saving algorithm for cloud resource management using a Kalman filter

Cloud computing has emerged as a promising technique to provide storage and computing component on‐demand services over a network. In this paper, we present an energy‐saving algorithm using the Kalman filter for cloud resource management to predict the workload and to further achieve high resource availability with low service level agreement. Using the proposed algorithm, one can estimate the potential future workload trend then predict the computing component workload utilizations and further retrench energy consumption and achieve load balancing in a cloud system. Experimental results show that the proposed algorithm achieves more than 92.22% accuracy in the computing component workload prediction, improves 55.11% energy in energy consumption, and has 3.71% in power prediction error rate, respectively. Copyright © 2013 John Wiley & Sons, Ltd.     

Power‐conservative server consolidation based resource management in cloud

The cloud computing environment is a real‐time communication network that involves a large number of systems connected in a distributed fashion, for which resources are available on demand. In recent years, due to the enormous growth of data and information, data maintenance tasks involve a major effort in information technology (IT) industries. So, IT industries are concentrating on the cloud computing environment in order to maintain their data and manage their resources. Owing to the increase in the number of data centres, which have an impact on electrical energy cost, peak power dissipation, cooling and carbon emission, power‐conservation‐based resource management is essential. A best‐fit heuristic job placement algorithm is proposed in this paper in order to increase the job allocation percentage, a worst‐fit heuristic virtual machine (VM) placement algorithm is also proposed in order to place the VMs over the physical machines (PMs) thereby reducing the number of the latter allotted, and a server consolidation algorithm is proposed in order to improve power conservation. Copyright © 2014 John Wiley & Sons, Ltd.     

浅析云计算节能技术与应用

云计算技术发展为数据中心节能减排提供了新的技术保障,本文梳理了云计算技术体系下节能减排的关键技术,并对数据中心服务器整合过程中的能耗进行统计分析。     

Ultrafast Laser Pulses Enable One‐Step Graphene Patterning on Woods and Leaves for Green Electronics

Fast, simple, cost‐efficient, eco‐friendly, and design‐flexible patterning of high‐quality graphene from abundant natural resources is of immense interest for the mass production of next‐generation graphene‐based green electronics. Most electronic components have been manufactured by repetitive photolithography processes involving a large number of masks, photoresists, and toxic etchants; resulting in slow, complex, expensive, less‐flexible, and often corrosive electronics manufacturing processes to date. Here, a one‐step formation and patterning of highly conductive graphene on natural woods and leaves by programmable irradiation of ultrafast high‐photon‐energy laser pulses in ambient air is presented. Direct photoconversion of woods and leaves into graphene is realized at a low temperature by intense ultrafast light pulses with controlled fluences. Green graphene electronic components of electrical interconnects, flexible temperature sensors, and energy‐storing pseudocapacitors are fabricated from woods and leaves. This direct graphene synthesis is a breakthrough toward biocompatible, biodegradable, and eco‐friendlily manufactured green electronics for the sustainable earth.     

Rear‐Illuminated Perovskite Photorechargeable Lithium Battery

Photovoltaic power‐conversion systems can harvest energy from sunlight almost perpetually whenever sunrays are accessible. Meanwhile, as indispensable energy storage units used in advanced technologies such as portable electronics, electric vehicles, and renewable/smart grids, batteries are energy‐limited closed systems and require constant recharging. Fusing these two essential technologies into a single device would create a sustainable power source. Here, it is demonstrated that such an integrated device can be realized by fusing a rear‐illuminated single‐junction perovskite solar cell with Li₄Ti₅O₁₂‐LiCoO₂ Li‐ion batteries, whose photocharging is enabled by an electronic converter via voltage matching. This design facilitates a straightforward monolithic stacking of the battery on the solar cell using a common metal substrate, which provides a robust mechanical isolation between the two systems while simultaneously providing an efficient electrical interconnection. This system delivers a high overall photoelectric conversion‐storage efficiency of 7.3%, outperforming previous efforts on stackable integrated architectures with organic–inorganic photovoltaics. Furthermore, converter electronics facilitates system control with battery management and maximum power point tracking, which are inevitable for efficient, safe, and reliable operation of practical loads. This work presents a significant advancement toward integrated photorechargeable energy storage systems as next‐generation power sources.     

An energy‐saving‐centric downlink scheduling scheme for WiMAX networks

This study proposes an energy‐saving‐centric downlink scheduling scheme to support efficient power utilization and to satisfy the QoS requirements. The base station considers the queue lengths of mobile stations with real‐time and non‐real‐time connections and considers their QoS requirements to determine the sleeping parameters when the mobile stations issue sleep requests. The proposed scheme appropriately reschedules the sleep‐requesting mobile station to transmit its queued packets for optimal power‐saving efficiency. The QoS requirement is considered as the constraint during traffic rescheduling. The treatment of real‐time connections generally requires a trade‐off of the delay requirement and the longer sleep window, and the non‐real‐time connections must concern the packet drop and minimum data rates when performing the energy‐centric scheduling. Two rescheduling algorithms, that is, whole and partial reschedules, are proposed and analyzed in this paper. The whole‐reschedule scheme provides improved energy‐saving performance at the cost of tolerable longer delay and computing complexity when compared with the partial‐reschedule scheme. Our simulation results indicated that both schemes not only guarantee the desired QoS but also achieve superior energy‐saving efficiency to that of traditional scheduling. Copyright © 2012 John Wiley & Sons, Ltd.     

新能源技术在通信基站供电系统中的应用

文中旨在探究新能源技术在通信供电系统中的应用。随着国内5G网络的正式商用,人们对信息的处理、传输、交互等的要求越来越高,原有的通信基站规模已无法满足人们日益增长的通信需求,越来越多的通信基站正在选址、设计、建设及投运。同时,考虑到能源的可持续发展,需减少对传统化石能源的依赖,存量通信基站及新建通信基站都应考虑对新能源技术的应用与研究。文中提出了新能源技术在通信供电系统中的具体应用,希望能促进通信供电系统的能源结构转型,扩大绿色能源的应用范围。     

Green power: status and perspectives

The main objective of the so-called green power marketing is to provide selective customers of electric energy with choices to purchase electric energy from sustainable, environmentally friendly sources. This paper presents a rationale for marketing of green power provides a brief overview of some of the existing efforts in the United States and abroad, and attempts to identify the conditions and future trends for survival of renewable energy in the energy marketplace. Our goal is primarily to provide a representative sample of the current technology status, rather than a comprehensive coverage of worldwide initiatives in this area     

A technique to improve network lifetime in mobile ad hoc networks

Energy is an important issue in mobile ad hoc networks (MANETs), and different energy‐aware routing mechanisms have been proposed to minimize the energy consumption in MANETs. Most of the energy‐aware routing schemes reported in the literature have considered only the residual battery capacity as the cost metric in computing a path. In this paper, we have proposed, an energy‐aware routing technique which considers the following parameters: (i) a cost metric, which is a function of residual battery power and energy consumption rate of participating nodes in path computation; (ii) a variable transmission power technique for transmitting data packets; and (iii) To minimize the over‐utilization of participating nodes, a limit is set on the number of paths that can be established to a destination through a participating node. The proposed scheme is simulated using Qualnet 4.5 simulator, and compared with Ad hoc On‐Demand Distance Vector (AODV) and Lifetime Enhancement Routing (LER). We observed that the proposed scheme performs better in terms of network lifetime and energy consumption. Copyright © 2014 John Wiley & Sons, Ltd.     

Energy‐aware supply route data collecting methods using wireless sensor networks

In military action, marching is a common method used for supply‐troop movement. Supply routes are typically in the wilderness where the route conditions change over time. This paper proposes a power‐saving algorithm allowing supply troops to collect route information using wireless sensor network technology. Each member in the marching supply troop is equipped with a battery‐powered sensor. To save power consumption, the proposed methods schedule the sleeping period for each member according to the size of the marching supply troop and its moving velocity. Two data carrying methods are proposed to reduce the frequency of long‐distance data uploading. The first method allows the uploaded data to be carried within a single‐round data collection period, and the second method extends the data carrying period to multiple rounds. The simulation results show that scheduling a sleep period can prolong the sensing distance along the route. These two proposed methods can add an additional 18–70% in distance data over methods without scheduling a sleep period. The energy spent on long‐distance data transmissions can be improved by 7–25%. Copyright © 2015 John Wiley & Sons, Ltd.     

Efficient Maximum Power Tracking of Energy Harvesting Using a μController for Power Savings

This letter describes an efficient technique for maximum power point tracking (MPPT) of an energy harvesting device. It is based on controlling the device voltage at the point of maximum power. Using a microcontroller with a power saving technique, the MPPT algorithm maintains the maximum power with low power consumption. An experiment shows that the algorithm maximizes the energy transfer power using an energy management IC fabricated in a 0.18‐μm process. Compared to direct energy transfer to a battery, the proposed technique is more efficient for low‐energy harvesting under variable conditions.     

Flexible Prime‐Field Genus 2 Hyperelliptic Curve Cryptography Processor with Low Power Consumption and Uniform Power Draw

This paper presents an energy‐efficient (low power) prime‐field hyperelliptic curve cryptography (HECC) processor with uniform power draw. The HECC processor performs divisor scalar multiplication on the Jacobian of genus 2 hyperelliptic curves defined over prime fields for arbitrary field and curve parameters. It supports the most frequent case of divisor doubling and addition. The optimized implementation, which is synthesized in a 0.13 μm standard CMOS technology, performs an 81‐bit divisor multiplication in 503 ms consuming only 6.55 μJ of energy (average power consumption is 12.76 μW). In addition, we present a technique to make the power consumption of the HECC processor more uniform and lower the peaks of its power consumption.     

绿色无线通信技术相关研究与标准化

绿色通信是当前通信领域的关注重点,通信产业中的能量消耗决定了网络运营成本,也影响了节能减排与环境保护.无线通信是目前通信的主要方式,因此绿色无线通信更值得关注.本文总结了相关标准组织对绿色通信、网络节能的标准化工作,同时从现有蜂窝网络中的节能技术、下一代蜂窝网络中的节能技术两个方面进行了讨论,为未来绿色通信技术相关研究...     

Self‐Supported Cobalt Phosphide Mesoporous Nanorod Arrays: A Flexible and Bifunctional Electrode for Highly Active Electrocatalytic Water Reduction and Oxidation

Water splitting for the production of hydrogen and oxygen is an appealing solution to advance many sustainable and renewable energy conversion and storage systems, while the key fact depends on the innovative exploration regarding the design of efficient electrocatalysts. Reported herein is the growth of CoP mesoporous nanorod arrays on conductive Ni foam through an electrodeposition strategy. The resulting material of well‐defined mesoporosity and a high specific surface area (148 m² g^?1) can be directly employed as a bifunctional and flexible working electrode for both hydrogen and oxygen evolution reactions, showing superior activities as compared with noble metal benchmarks and state‐of‐the‐art transition‐metal‐based catalysts. This is intimately related to the unique nanorod array electrode configuration, leading to excellent electric interconnection and improved mass transport. A further step is taken toward an alkaline electrolyzer that can achieve a current density of 10 mA cm^?2 at a voltage around 1.62 V over a long‐term operation, better than the combination of Pt and IrO₂. This development is suggested to be readily extended to obtain other electrocatalysis systems for scale‐up water‐splitting technology.     

绿色基站解决方案与实现技术

基站功耗是无线通信系统功耗的主体。基站绿色节能解决方案是无线网络绿色节能的首要目标。基于绿色基站解决方案涉及基站架构、基站形态、绿色基站节能技术及绿色站点应用等多个方面,文章提出绿色基站解决方案,探求基站节能降耗的有效途径。     

PAVM: a framework for policy‐aware virtual machine management

The problem of efficient placement of virtual machines (VMs) in cloud computing infrastructure is well studied in the literature. VM placement decision involves selecting a physical machine in the data center to host a specific VM. This decision could play a pivotal role in yielding high efficiency for both the cloud and its users. Also, reallocation of VMs could be performed through migrations to achieve goals like higher server consolidation or power saving. VM placement and reallocation decisions may consider affinities such as memory sharing, CPU processing, disk sharing, and network bandwidth requirements between VMs defined in multiple dimensions. Considering the NP‐hard complexity associated with computing an optimal solution for this VM placement decision problem, existing research employs heuristic‐based techniques to compute an efficient solution. However, most of these approaches are restricted to only a single attribute at a time. That is, a given technique of using heuristics to compute VM placement considers only a single attribute, while completely ignoring the impact of other dimensions of placing VMs. While this approach may improve the efficiency with respect to the affinity attribute in consideration, it may yield degraded performance with respect to other affinities. In addition, the criteria for determining VM‐placement efficiency may vary for different applications. Hence, the overall goal of achieving VM placement efficiency becomes difficult and challenging. We are motivated by this challenging problem of efficient VM placement and propose policy‐aware virtual machine management (PAVM), a generic framework that can be used for efficient VM management in a cloud computing platform based on the service provider‐defined policies to achieve the desired system‐wide goals. This involves efficient means to profile different VM affinities and to use profiled information effectively by intelligent and efficient VM migrations at run time considering multiple attributes at a time. By conducting extensive evaluation through simulation and real experiments that involve VM affinities on the basis of network and memory, we confirmed that the PAVM architecture is capable of improving the efficiency of a cloud system. We elaborate the architecture of a PAVM system, describe its implementation, and present details of our experiments. Copyright © 2016 John Wiley & Sons, Ltd.