期刊文献+
共找到73篇文章
< 1 2 4 >
每页显示 20 50 100
Power consumption in a field emission panel
1
作者 李晨 雷威 +1 位作者 张晓兵 顾伟 《Journal of Southeast University(English Edition)》 EI CAS 2006年第1期39-42,共4页
The power consumption and electric field distribution in a field emission display (FED) panel is optimized with a novel pixel structure. A circuit model is proposed to estimate the total power consumption in an FED ... The power consumption and electric field distribution in a field emission display (FED) panel is optimized with a novel pixel structure. A circuit model is proposed to estimate the total power consumption in an FED panel which is composed of anode energy consumption, energy loss due to the leakage current and the energy dissipated in the parasitic capacitances. Moreover, the parasitic capacitances play a vital part in the power consumption and driving performance. In order to lower the parasitic capacitances, multiple dielectric layers are used as the gate electrode. Due to different etching speeds, a novel pixel structure is formed. As a result, the power consumption of an FED panel is reduced by 28% in a full white picture, and the electron beam performance is also better than that of the conventional structure. 展开更多
关键词 field emission display power consumption circuit model
下载PDF
Influences of nonassociated flow rules on seismic bearing capacity factors of strip footing on soil slope by energy dissipation method 被引量:14
2
作者 杨小礼 郭乃正 +1 位作者 赵炼恒 邹金锋 《Journal of Central South University of Technology》 EI 2007年第6期842-847,共6页
Seismic bearing capacity factors of a strip footing placed on soil slope were determined with both associated and nonassociated flow rules. Quasi-static representation of earthquake effects using a seismic coefficient... Seismic bearing capacity factors of a strip footing placed on soil slope were determined with both associated and nonassociated flow rules. Quasi-static representation of earthquake effects using a seismic coefficient concept was adopted for seismic bearing capacity calculations. A multi-wedge translational failure mechanism was used to obtain the seismic bearing capacity factors for different seismic coefficients and various inclined angles. Employing the associated flow rule, numerical results were compared with the published solutions. For bearing capacity factors related to cohesion and equivalent surcharge load, the maximum difference approximates 0.1%. However, the difference of bearing capacity factor related to unit weight is larger. With the two flow rules, the seismic bearing capacity factors were presented in the form of design charts for practical use. The results show that seismic bearing capacity factors related to the cohesion, the equivalent surcharge load and the unit weight increase greatly as the dilatancy angle increases, and that the nonassociated flow rule has important influences on the seismic bearing capacity. 展开更多
关键词 nonassociated flow rule seismic bearing capacity factor EARTHQUAKE
下载PDF
Bearing capacity of foundation on slope determined by energy dissipation method and model experiments 被引量:15
3
作者 杨小礼 王志斌 +1 位作者 邹金锋 李亮 《Journal of Central South University of Technology》 EI 2007年第1期125-128,共4页
To determine the ultimate bearing capacity of foundations on sloping ground surface in practice, energy dissipation method was used to formulate the beating capacity as programming problem, and full-scale model experi... To determine the ultimate bearing capacity of foundations on sloping ground surface in practice, energy dissipation method was used to formulate the beating capacity as programming problem, and full-scale model experiments were investigated to analyze the performance of the soil slopes loaded by a strip footing in laboratory. The soil failure is governed by a linear Mohr-Coulomb yield criterion, and soil deformation follows an associated flow rule. Based on the energy dissipation method of plastic mechanics, a multi-wedge translational failure mechanism was employed to obtain the three bearing capacity factors related to cohesion, equivalent surcharge load and the unit gravity for various slope inclination angles. Numerical results were compared with those of the published solutions using finite element method and those of model experiments. The bearing capacity factors were presented in the form of design charts for practical use in engineering. The results show that limit analysis solutions approximate to those of model tests, and that the energy dissipation method is effective to estimate bearing capacity of soil slope. 展开更多
关键词 energy dissipation bearing capacity soil slope model experiment
下载PDF
Numerical Investigation of Constructal Distributors with Different Configurations 被引量:5
4
作者 范志伟 周兴贵 +1 位作者 罗灵爱 袁渭康 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第1期175-178,共4页
Seven distributors with different configurations are designed and optimized by constructal approach. Their flow distribution performance and energy dissipation are investigated and compared by computational fluid dyna... Seven distributors with different configurations are designed and optimized by constructal approach. Their flow distribution performance and energy dissipation are investigated and compared by computational fluid dynamics (CFD) simulation. The reliability of CFD simulation is verified by experiments on the distributor that has all distributing rectangle channels on a plate. The results show that the symmetry of the distributing channels has decisive influence on the performance of flow distribution. Increasing the generations of channel branching will improve the flow distribution uniformity, but on the other hand increase the energy dissipation. Among all the seven constructal distributors, the distributor that has dichotomy configuration, Y-type junctions and straight interconnecting channels, is recommended for its better flow distribution performance and less energy dissipation. 展开更多
关键词 constructal distributor CONFIGURATION flow distribution energy dissipation
下载PDF
Adaptive ant-based routing in wireless sensor networks using Energy~* Delay metrics 被引量:6
5
作者 Yao-feng WEN Yu-quan CHEN Min PAN 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第4期531-538,共8页
To find the optimal routing is always an important topic in wireless sensor networks (WSNs). Considering a WSN where the nodes have limited energy, we propose a novel Energy*Delay model based on ant algorithms ("... To find the optimal routing is always an important topic in wireless sensor networks (WSNs). Considering a WSN where the nodes have limited energy, we propose a novel Energy*Delay model based on ant algorithms ("E&D ANTS" for short) to minimize the time delay in transferring a fixed number of data packets in an energy-constrained manner in one round. Our goal is not only to maximize the lifetime of the network but also to provide real-time data transmission services. However, because of the tradeoff of energy and delay in wireless network systems, the reinforcement learning (RL) algorithm is introduced to train the model. In this survey, the paradigm of E&D ANTS is explicated and compared to other ant-based routing algorithms like AntNet and AntChain about the issues of routing information, routing overhead and adaptation. Simulation results show that our method performs about seven times better than AntNet and also outperforms AntChain by more than 150% in terms of energy cost and delay per round. 展开更多
关键词 Ant colony optimization (ACO) PHEROMONES Power consumption Wireless sensor networks (WSNs)
下载PDF
Energy Consumption in Comminution of Mica with Cavitation Abrasive Water Jet 被引量:12
6
作者 GUO Chu-wen DONG Lu 《Journal of China University of Mining and Technology》 EI 2007年第2期251-254,共4页
We have studied the efficiency of energy consumption in the comminution of mica powder with cavitation abrasive water jet technology. The energy required to create new surfaces in the comminution of mica powder with c... We have studied the efficiency of energy consumption in the comminution of mica powder with cavitation abrasive water jet technology. The energy required to create new surfaces in the comminution of mica powder with cavitation abrasive water jet was calculated,in order to estimate its efficiency of energy consumption. The particle size distribution and the specific surface area were measured by applying a JEM-200CX transmission electron microscope and an Autosorb-1 automatic surface area analyzer. The study results show that the efficiency of energy consumed in creating new surface areas is as high as 2.92%,or 4.94% with the aid of cavitation in the comminution of mica powder. This efficiency will decrease with an increase in the number of comminutions. After three comminutions,the efficien-cies will become 1.91% and 2.29% for comminution without cavitation and with cavitation,respectively. The abrasive water jet technology is an effective way for comminution of mica powder. 展开更多
关键词 energy consumption comminution MICA cavitation abrasive water jet
下载PDF
A Game Theoretic Approach for Energy-Efficient In-Network Caching in Content-Centric Networks 被引量:4
7
作者 FANG Chao YU F. Richard +2 位作者 HUANG Tao LIU Jiang LIU Yunjie 《China Communications》 SCIE CSCD 2014年第11期135-145,共11页
Recently, content-centric networking (CCN) has become a hot research topic for the diffusion of contents over the Internet. Most existing works on CCN focus on the improvement of network resource utilization. Conseq... Recently, content-centric networking (CCN) has become a hot research topic for the diffusion of contents over the Internet. Most existing works on CCN focus on the improvement of network resource utilization. Consequently, the energy consumption aspect of CCN is largely ignored. In this paper, we propose a distributed energyefficient in-network caching scheme for CCN, where each content router only needs locally available information to make caching decisions considering both caching energy consumption and transport energy consumption. We formulate the in-network caching problem as a non-cooperative game. Through rigorous mathematical analysis, we prove that pure strategy Nash equilibria exist in the proposed scheme, and it always has a strategy profile that implements the socially optimal configuration, even if the touters are self-interested in nature. Simulation results are presented to show that the distributed solution is competitive to the centralized scheme, and has superior performance compared to other popular caching schemes in CCN. Besides, it exhibits a fast convergence speed when the capacity of content routers varies. 展开更多
关键词 in-network caching contentcentric networking energy efficiency noncooperative game
下载PDF
A low-power Rijndael S-Box based on pass transmission gate and composite field arithmetic 被引量:2
8
作者 ZENG Yong-hong ZOU Xue-cheng +1 位作者 LIU Zheng-lin LEI Jian-ming 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第10期1553-1559,共7页
Using composite field arithmetic in Galois field can result in the compact Rijndael S-Box. However, the power con- sumption of this solution is too large to be used in resource-limited embedded systems. A full-custom ... Using composite field arithmetic in Galois field can result in the compact Rijndael S-Box. However, the power con- sumption of this solution is too large to be used in resource-limited embedded systems. A full-custom hardware implementation of composite field S-Box is proposed for these targeted domains in this paper. The minimization of power consumption is implemented by optimizing the architecture of the composite field S-Box and using the pass transmission gate (PTG) to realize the logic functions of S-Box. Power simulations were performed using the netlist extracted from the layout. HSPICE simulation results indicated that the proposed S-Box achieves low power consumption of about 130 μW at 10 MHz using 0.25 μm/2.5 V technology, while the consumptions of the positive polarity reed-muller (PPRM) based S-Box and composite field S-Box based on the conventional CMOS logic style are about 240 μW and 420 μW, respectively. The simulations also showed that the presented S-Box obtains better low-voltage operating property, which is clearly relevant for applications like sensor nodes, smart cards and radio frequency identification (RFID) tags. 展开更多
关键词 Composite field Rijndael S-Box FULL-CUSTOM Pass transmission gate (PTG) Low power consumption LOW-VOLTAGE
下载PDF
Response and energy dissipation of rock under stochastic stress waves 被引量:4
9
作者 邓建 边利 《Journal of Central South University of Technology》 EI 2007年第1期111-114,共4页
The response and energy dissipation of rock under stochastic stress waves were analyzed based on dynamic fracture criterion of brittle materials integrating with Fourier transform methods of spectral analysis. When th... The response and energy dissipation of rock under stochastic stress waves were analyzed based on dynamic fracture criterion of brittle materials integrating with Fourier transform methods of spectral analysis. When the stochastic stress waves transmit through rocks, the frequency and energy ratio of harmonic components were calculated by analytical and discrete analysis methods. The stress waves in shale, malmstone and liparite were taken as examples to illustrate the proposed analysis methods. The results show the harder the rock, the less absorption of energy, the more the useless elastic waves transmitting through rock, and the narrower the cutoff frequency to fracture rock. When the whole stress energy doubles either by doubling the duration time or by increasing the amplitude of stress wave, ratio of the energy of elastic waves transmitting through rock to the whole stress energy (i.e. energy dissipation ratio) is decreased to 10%-15%. When doubling the duration time, the cutoff frequency to fracture rock remains constant. However, with the increase of the amplitude of stress wave, the cutoff frequency increases accordingly. 展开更多
关键词 stochastic stress waves dynamic fracture criterion Fourier transform energy dissipation ROCK
下载PDF
Grid-based energy-aware routing in wireless sensor networks
10
作者 刘曙 庄艳艳 +1 位作者 王芳芳 陶军 《Journal of Southeast University(English Edition)》 EI CAS 2009年第4期445-450,共6页
The model of energy cost in a wireless sensor network (WSN)environment is built, and the energy awareness and the wireless interference mainly due to different path loss models are studied. A special case of a clust... The model of energy cost in a wireless sensor network (WSN)environment is built, and the energy awareness and the wireless interference mainly due to different path loss models are studied. A special case of a clustering scheme, a twodimensional grid clustering mechanism, is adopted. Clusterheads are rotated evenly among all sensor nodes in an efficient and decentralized manner, based on the residual energy in the battery and the random backoff time. In addition to transmitting and receiving packets within the sensors' electrical and amplification circuits, extra energy is needed in the retransmission of packets due to packet collisions caused by severe interference. By analysis and mathematical derivation, which are based on planar geometry, it is shown that the total energy consumed in the network is directly related to the gridstructure in the proposed grid based clustering mechanism. The transmission range is determined by cluster size, and the path loss exponent is determined by nodal separation. The summation of overall interference is caused by all the sensors that are transmitting concurrently. By analysis and simulation, an optimal grid structure with the corresponding grid size is presented, which balances between maximizing energy conservation and minimizing overall interference in wireless sensor networks. 展开更多
关键词 wireless sensor networks: grid: energy consumption: interference: packet loss
下载PDF
Sources and significance of variation in basal,summit and maximal metabolic rates in birds 被引量:7
11
作者 Andrew E. MCKECHNIE David L. SWANSON 《Current Zoology》 SCIE CAS CSCD 北大核心 2010年第6期741-758,共18页
The rates at which birds use energy may have profound effects on fitness, thereby influencing physiology, behavior, ecology and evolution. Comparisons of standardized metabolic rates (e.g., lower and upper limits of ... The rates at which birds use energy may have profound effects on fitness, thereby influencing physiology, behavior, ecology and evolution. Comparisons of standardized metabolic rates (e.g., lower and upper limits of metabolic power output) present a method for elucidating the effects of ecological and evolutionary factors on the interface between physiology and life history in birds. In this paper we review variation in avian metabolic rates [basal metabolic rate (BMR; minimum normothermic metabolic rate), summit metabolic rate (Msum; maximal thermoregulatory metabolic rate), and maximal metabolic rate (MMR; maximal exercise metabolic rate)], the factors associated with this variation, the evidence for functional links between these metabolic traits, and the ecological and evolutionary significance of avian metabolic diversity. Both lower and upper limits to metabolic power production are phenotypically flexible traits, and vary in association with numerous ecological and evolutionary factors. For both inter- and intraspecific comparisons, lower and upper limits to metabolic power production are generally upregulated in response to energetically demanding conditions and downregulated when energetic demands are relaxed, or under conditions of energetic scarcity. Positive correlations have been documented between BMR, Msum and MMR in some, but not all studies on birds, providing partial support for the idea of a functional link between lower and upper limits to metabolic power production, but more intraspecific studies are needed to determine the robustness of this conclusion. Correlations between BMR and field metabolic rate (or daily energy expenditure) in birds are variable, suggesting that the linkage between these traits is subject to behavioral adjustment, and studies of the relationship between field and maximal metabolic rates are lacking. Our understanding of avian metabolic diversity would benefit from future studies of: (1) the functional and mechanistic links between lower and upper limits of metabolic power output; (2) the environmental and ecological cues driving phenotypically flexible metabolic responses, and how responses to such cues might impact population responses to climate change; (3) the shapes of metabolic reaction norms and their association with environmental variability; and (4) the relationship of metabolic variation to fitness, including studies of repeatability and heritability of minimum and maximum metabolic power output [Current Zoology 56 (6): 741-758, 2010]. 展开更多
关键词 Phenotypic flexibility Reaction norms Basal metabolic rate Maximal metabolic rate BIRDS
下载PDF
Behavioral and physiological flexibility are used by birds to manage energy and support investment in the early stages of reproduction 被引量:2
12
作者 Franois VZINA Katrina G. SALVANTE 《Current Zoology》 SCIE CAS CSCD 北大核心 2010年第6期767-792,共26页
Interest in phenotypic flexibility has increased dramatically over the last decade, but flexibility during reproduction has received relatively little attention from avian scientists, despite its possible impact on fi... Interest in phenotypic flexibility has increased dramatically over the last decade, but flexibility during reproduction has received relatively little attention from avian scientists, despite its possible impact on fitness. Because most avian species maintain atrophied reproductive organs when not active, reproduction in birds requires major tissue remodeling in preparation for breeding. Females undergo rapid (days) recrudescence and regression of their reproductive organs at each breeding attempt, while males grow their organs ahead of time at a much slower rate (weeks) and may maintain them at maximal size throughout the breeding season. Reproduction is associated with significant metabolic costs. Egg production leads to a 22%-27% increase in resting metabolic rate (RMR) over non-reproductive values. This is partly due to the activity of the oviduct, an organ that may allow females to adjust reproductive investment by modulating egg size and quality. In males, gonadal recrudescence may lead to a 30% increase in RMR, but the data are inconsistent and general conclusions regarding energetic costs of reproduction in males will require more research. Recent studies on captive female zebra finches describe the impacts of these costs on daily energy budgets and highlight the strategies used by birds to maintain their investment in reproduction when energy is limited. Whenever possible, birds use behavioral flexibility as a first means of saving energy. Decreasing locomotor activity saves energy during challenges such as egg production or exposure to cold temperatures and is an efficient way to buffer variation in individual daily energy budgets. However, when behavioral flexibility is not possible, birds must rely on flexibility at the physiological level to meet energy demands. In zebra finches breeding in the cold, this results in a reduced pace of laying, likely due to down-regulation of both reproductive and non-reproductive function, allowing females to defend minimal egg size and maintain reproductive success. More research involving a range of species in captive and flee-living conditions is needed to determine how phenotypic flexibility during tissue remodeling and early reproductive investment translates to natural conditions and affects fitness [Current Zoology 56 (6): 767-792, 2010]. 展开更多
关键词 Phenotypic plasticity Phenotypic flexibility BMR Energy budget ORGAN Egg size Physiological tradeoff Fitness
下载PDF
Energy dissipation of cavity expansion based on generalized non-linear failure criterion under high stresses 被引量:3
13
作者 邹金锋 童无欺 赵健 《Journal of Central South University》 SCIE EI CAS 2012年第5期1419-1424,共6页
Based on the compression mechanism for analyzing the cavity expansion problem in soil under high stresses,generalized non-linear failure criterion and large strain and energy conservation in plastic region during the ... Based on the compression mechanism for analyzing the cavity expansion problem in soil under high stresses,generalized non-linear failure criterion and large strain and energy conservation in plastic region during the cavity expanding were adopted.The energy conservation equation was established and the limited pressure of cavity expansion under high stresses was given based on the energy dissipation analysis method,in which the energy generated from cavity expansion is absorbed by the volume change and shear strain caused in soil.The factors of large strain and dilatation were considered by the proposed method.The analysis shows that the limited pressure is determined by failure criterion,stress state,large deformation characteristic,dilatation and strength of soil.It is shown from the comparison that the results with the proposed method approximate to those of the in-situ method.The cavity expansion pressure first decreases and then increases nonlinearly with both of shear modulus and dilatation increasing. 展开更多
关键词 energy dissipation energy conservation large strain cavity expansion high stress
下载PDF
Numerical analysis of grinding power consumption of a vertical planetary mill 被引量:3
14
作者 HAO Xue-di ZHU Dong-mei +1 位作者 BIAN Zhi-rui WANG Xin 《Journal of China University of Mining and Technology》 EI 2008年第2期311-315,共5页
Planetary wheel rolling on a coal-bed was simplified as rigid wheel rolling on the coal-bed with a rigid base when a Ver- tical planetary mill(VPM)is running.Based on our analysis,we conclude that the Bekker formulati... Planetary wheel rolling on a coal-bed was simplified as rigid wheel rolling on the coal-bed with a rigid base when a Ver- tical planetary mill(VPM)is running.Based on our analysis,we conclude that the Bekker formulation for computing rolling resis- tance is not applicable to calculate directly the rolling resistance of the wheel.According to the principle of the Bekker apparatus,pressure-sinkage curves were obtained by tests on a piece of mono-axial consolidation apparatus used in soil-mechanics.The de- formation modulus of the coal-bed was calculated using elastic mechanics.A finite element model of the planetary wheel coal-bed was built up by the use of a rigid and a Drucker-Prager material model in LS-DYNA.According to the simulation results,the wheel rolling resistance,the grinding power consumption and the motor power of the mill were calculated and the mistake in the initial design of the mill was modified.The simulation results agree well with the results of the semi-industrial tests. 展开更多
关键词 VPM power-consumption GRINDING ROLLING finite element method (FEM)
下载PDF
A vector inserting TPG for BIST design with low peak power consumption 被引量:2
15
作者 谈恩民 Song Shengdong Shi Wenkang 《High Technology Letters》 EI CAS 2007年第4期418-421,共4页
A test pattern generator (TPG) which can highly reduce the peak power consumption during built-in self-test (BIST) application is proposed. The proposed TPG, called LPpe-TPG, consists of a linear feedback shift re... A test pattern generator (TPG) which can highly reduce the peak power consumption during built-in self-test (BIST) application is proposed. The proposed TPG, called LPpe-TPG, consists of a linear feedback shift register (LFSR) and some control circuits. A procedure is presented firstly to make compare vectors between pseudorandom test patterns by adding some circuits to the original LFSR and secondly to insert some vectors between two successive pseudorandom test patterns according to the ordinal selection of every two bits of the compare vector. Then the changes between any successive test patterns of the test set generated by the LPpe-TPG are not more than twice. This leads to a decrease of the weighted switching activity (WSA) of the circuit under test (CUT) and therefore a reduction of the power consumption. Experimental results based on some ISCAS' 85 benchmark circuits show that the peak power consumption has been reduced by 25.25% to 64.46%. Also, the effectiveness of our approach to reduce the total and average power consumption is kept, without losing stuck-at fault coverage. 展开更多
关键词 low peak power consumption design built-in self-test (BIST) test pattern generator(TPG) linear feedback shift register (LFSR) weighted switching activity (WSA)
下载PDF
Energy expenditure and muscular activation patterns through active sitting on compliant surfaces 被引量:1
16
作者 D.Clark Dickin Rachel K.Surowiec Henry Wang 《Journal of Sport and Health Science》 SCIE 2017年第2期207-212,共6页
Purpose: To test the effectiveness of sitting surfaces with varied amounts of stability on muscle activity and energy expenditure.Methods: Using a within-participants repeated measures design, 11 healthy young-adult f... Purpose: To test the effectiveness of sitting surfaces with varied amounts of stability on muscle activity and energy expenditure.Methods: Using a within-participants repeated measures design, 11 healthy young-adult females(age = 20.0 ± 1.8 years) were measured using indirect calorimetry to assess energy expenditure, and electromyography to assess muscular activation in trunk and leg musculature under 3different sitting surfaces: flat-firm surface, air-filled cushion, and a stability ball. Data were analyzed using repeated measures analysis of variance with follow-up pairwise contrasts used to determine the specific effects of sitting surface on muscle activation and energy expenditure.Results: Significantly greater energy expenditure was recorded for the stability ball(p = 0.01) and the cushion(p = 0.03) over the flat surface(10.4% and 9.6% greater, respectively), with no differences between the ball and the cushion. Both the ball and the cushion produced higher tibialis anterior activation over the flat surface(1.09 and 0.63 root-mean-square millivolts(RMSmv), respectively), while the stability ball produced higher soleus activity over both cushion and flat surfaces(3.97 and 4.24 RMSmv, respectively). Additionally, the cushion elicited higher adductor longus activity over the ball and flat surfaces(1.76 and 1.81 RMSmv, respectively), but no trunk musculature differences were revealed.Conclusion: Compliant surfaces resulted in higher levels of muscular activation in the lower extremities facilitating increased caloric expenditure.Given the increasing trends in sedentary careers and the increases in obesity, this is an important finding to validate the merits of active sitting facilitating increased caloric expenditure and muscle activation. 展开更多
关键词 Energy metabolism ELECTROMYOGRAPHY Female POSTURE Sedentary lifestyle WORKPLACE
下载PDF
Spectral and Energy Efficiency of Downlink MU-MIMO Systems with MRT 被引量:4
17
作者 Weiqiang Tan Shi Jin Jide Yuan 《China Communications》 SCIE CSCD 2017年第5期105-111,共7页
This paper studies the achievable spectral efficiency(SE)of downlink multiuser multiple-input-multiple-output(MIMO)system,where the base station(BS)is deployed an arbitrary finite antenna number and communicates simul... This paper studies the achievable spectral efficiency(SE)of downlink multiuser multiple-input-multiple-output(MIMO)system,where the base station(BS)is deployed an arbitrary finite antenna number and communicates simultaneously with many users. We assume that the BS has accurate channel state information(CSI)and adopt maximum ratio transmission(MRT)precoding. An accurate analytical result for the achievable SE is obtained. Based on the analytical result on the achievable SE,we further study the achievable energy efficiency(EE)of multiuser MIMO system by considering an energy consumption model. Results indicate that the increasing number of BS antennas can boost the achievable SE of system,whilst the achievable SE tends to a saturated rate in the high signal-tonoise ratios(SNR)regime. Furthermore,an important conclusion is that the increasing number of users is beneficial for the achievable EE and there is an optimal antenna number to maximize the EE of system. 展开更多
关键词 energy efficiency multiuser MIMO maximum ration transmission spectral efficiency
下载PDF
Comparison of heart rate monitoring with indirect calorimetry for energy expenditure evaluation 被引量:1
18
作者 Zhusheng Yu Eszter Volgyi +5 位作者 Ru Wang Andrea Ember Petri Wiklund Markku Alen Frances ATylavsky Sulin Cheng 《Journal of Sport and Health Science》 SCIE 2012年第3期178-183,195,共7页
Purpose:The purpose of this study was to compare established methods with newly-developed methods for estimating the total energy expenditure(TEE). Methods:The study subjects comprised 46 individuals,including 16 midd... Purpose:The purpose of this study was to compare established methods with newly-developed methods for estimating the total energy expenditure(TEE). Methods:The study subjects comprised 46 individuals,including 16 middle-aged men(mean age 51.4 years),14 middle-aged women(mean age 49.9 years) and 16 young women(mean age 19.1 years).The TEE was estimated from 24-h heart rate(HR) data using newly-developed software (MoveSense HRAnalyzer 201 la,RC1.Suunto Oy,Vantaa,Finland),and was compared against the TEE determined using doubly labeled water (DLW).Agreement between the two methods was analyzed using Bland and Altman plots. Results:The HR method yielded similar TEE values as the DLW method at the group level,with an average of 8.6 kcal/day in the difference in the mean,but with large individual variations.Forty-four(96%) out of 46 subjects fell within±2SD of the mean difference in TEE comparisons, and there was no tendency towards under- or over-estimation. Conclusion:Our results indicate that the current software using HR analysis for the estimation of daily TEE needs further development for use with free-living individuals. 展开更多
关键词 Doubly labeled water Heart rate monitoring Males and females Total energy expenditure
下载PDF
Efficiency of Structural Materials in Sustainable Design 被引量:1
19
作者 Ali Osman Kuruscu Zehra Canan Girgin 《Journal of Civil Engineering and Architecture》 2014年第10期1260-1265,共6页
The main aim of this paper is to investigate energy consumptions, CO2 emissions and costs during the production and life cycle of structural materials. The virgin and recycled metals as well as waste minerals such as ... The main aim of this paper is to investigate energy consumptions, CO2 emissions and costs during the production and life cycle of structural materials. The virgin and recycled metals as well as waste minerals such as fly ash, slag in concrete save energy consumption, CO2 emissions and costs. The importance and effectiveness of recycled materials will be statistically evaluated via energy consumption, carbon footprint, ultimate strength and their ratios. Embodied energy to ultimate strength or embodied carbon to ultimate strength ratios may emphasize the effectiveness of a sustainable material. The analyses in this study indicate the utilization of the recycled steel and C50 concrete with 50% fly ash or slag is the most efficient way of using sustainable materials. 展开更多
关键词 CO2 building materials ENERGY STRENGTH recycle.
下载PDF
Characteristics of viscous debris flow in a drainage channel with an energy dissipation structure 被引量:4
20
作者 CHEN Jian-gang CHEN Xiao-qing +1 位作者 CHEN Hua-yong ZHAO Wan-yu 《Journal of Mountain Science》 SCIE CSCD 2016年第2期223-233,共11页
A new type of drainage channel with an energy dissipation structure has been proposed based on previous engineering experiences and practical requirements for hazard mitigation in earthquakeaffected areas.Experimental... A new type of drainage channel with an energy dissipation structure has been proposed based on previous engineering experiences and practical requirements for hazard mitigation in earthquakeaffected areas.Experimental studies were performed to determine the characteristics of viscous debris flow in a drainage channel of this type with a slope of 15%.The velocity and depth of the viscous debris flow were measured,processed,and subsequently used to characterize the viscous debris flow in the drainage channel.Observations of this experiment showed that the surface of the viscous debris flow in a smooth drainage channel was smoother than that of a similar debris flow passing through the energy dissipation section in a channel of the new type studied here.However,the flow patterns in the two types of channels were similar at other points.These experimental results show that the depth of the viscous debris flow downstream of the energy dissipation structure increased gradually with the length of the energy dissipation structure.In addition,in the smooth channel,the viscous debris-flow velocity downstream of the energy dissipation structure decreased gradually with the length of the energy dissipation structure.Furthermore,theviscous debris-flow depth and velocity were slightly affected by variations in the width of the energy dissipation structure when the channel slope was 15%.Finally,the energy dissipation ratio increased gradually as the length and width of the energy dissipation structure increased;the maximum energy dissipation ratio observed was 62.9%(where B = 0.6m and L/w = 6.0). 展开更多
关键词 Debris flow Drainage channel Energy dissipation structure Geological disaster
下载PDF
上一页 1 2 4 下一页 到第
使用帮助 返回顶部