Estimating the Input Power of a Power Plant Using the Efficiency of the Inverter

The study focuses on estimating the input power of a power plant from available data, using the theoretical inverter efficiency as the key parameter. The paper addresses the problem of missing data in power generation systems and proposes an approach based on the efficiency formula widely documented in the literature. In the absence of input data, this method makes it possible to estimate the plant’s input power using data extracted from the site, in particular that provided by the Ministry of the Environment. The importance of this study lies in the need to accurately determine the input power in order to assess the overall performance of the energy system.

Layering Precision Land Leveling and Furrow Irrigated Raised Bed Planting: Productivity and Input Use Efficiency of Irrigated Bread Wheat in Indo-Gangetic Plains

Stagnating yield and declining input use efficiency in irrigated wheat of the Indo-Gangetic Plain (IGP) coupled with diminishing availability of water for agriculture is a major concern of food security in South Asia. The objective of our study was to establish an understanding of how wheat yield and input use efficiency can be improved and how land leveling and crop establishment practices can be modified to be more efficient in water use through layering of precision-conservation crop management techniques. The “precision land leveling with raised bed” planting can be used to improve crop yield, water and nutrient use efficiency over the existing “traditional land leveling with flat” planting practices. We conducted a field experiment during 2002-2004 at Modipuram, India to quantify the benefits of alternate land leveling (precision land leveling) and crop establishment (furrow irrigated raised bed planting) techniques alone or in combination (layering precision-conservation) in terms of crop yield, water savings, and nutrient use efficiency of wheat production in IGP. The wheat yield was about 16.6% higher with nearly 50% less irrigation water with layering precision land leveling and raised bed planting compared to traditional practices (traditional land leveling with flat planting). The agronomic (AE) and uptake efficiency (UE) of N, P and K were significantly improved under precision land leveling with raised bed planting technique compared to other practices.

Meta-analysis of CO_(2) conversion,energy efficiency,and other performance data of plasma-catalysis reactors with the open access PIONEER database

This paper brings the comparison of performances of CO_(2)conversion by plasma and plasma-assisted catalysis based on the data collected from literature in this field,organised in an open access online database.This tool is open to all users to carry out their own analyses,but also to contributors who wish to add their data to the database in order to improve the relevance of the comparisons made,and ultimately to improve the efficiency of CO_(2)conversion by plasma-catalysis.The creation of this database and database user interface is motivated by the fact that plasma-catalysis is a fast-growing field for all CO_(2)conversion processes,be it methanation,dry reforming of methane,methanolisation,or others.As a result of this rapid increase,there is a need for a set of standard procedures to rigorously compare performances of different systems.However,this is currently not possible because the fundamental mechanisms of plasma-catalysis are still too poorly understood to define these standard procedures.Fortunately however,the accumulated data within the CO_(2)plasma-catalysis community has become large enough to warrant so-called“big data”studies more familiar in the fields of medicine and the social sciences.To enable comparisons between multiple data sets and make future research more effective,this work proposes the first database on CO_(2)conversion performances by plasma-catalysis open to the whole community.This database has been initiated in the framework of a H_(2)0_(2)0 European project and is called the“PIONEER Data Base”.The database gathers a large amount of CO_(2)conversion performance data such as conversion rate,energy efficiency,and selectivity for numerous plasma sources coupled with or without a catalyst.Each data set is associated with metadata describing the gas mixture,the plasma source,the nature of the catalyst,and the form of coupling with the plasma.Beyond the database itself,a data extraction tool with direct visualisation features or advanced filtering functionalities has been developed and is available online to the public.The simple and fast visualisation of the state of the art puts new results into context,identifies literal gaps in data,and consequently points towards promising research routes.More advanced data extraction illustrates the impact that the database can have in the understanding of plasma-catalyst coupling.Lessons learned from the review of a large amount of literature during the setup of the database lead to best practice advice to increase comparability between future CO_(2)plasma-catalytic studies.Finally,the community is strongly encouraged to contribute to the database not only to increase the visibility of their data but also the relevance of the comparisons allowed by this tool.

Efficiency assessment of coal mine safety input by data envelopment analysis

In recent years improper allocation of safety input has prevailed in coal mines in China, which resulted in the frequent accidents in coal mining operation. A comprehensive assessment of the input efficiency of coal mine safety should lead to improved efficiency in the use of funds and management resources. This helps government and enterprise managers better understand how safety inputs are used and to optimize allocation of resources. Study on coal mine’s efficiency assessment of safety input was con- ducted in this paper. A C2R model with non-Archimedean infinitesimal vector based on output is established after consideration of the input characteristics and the model properties. An assessment of an operating mine was done using a specific set of input and output criteria. It is found that the safety input was efficient in 2002 and 2005 and was weakly efficient in 2003. However, the effi- ciency was relatively low in both 2001 and 2004. The safety input resources can be optimized and adjusted by means of projection theory. Such analysis shows that, on average in 2001 and 2004, 45% of the expended funds could have been saved. Likewise, 10% of the safety management and technical staff could have been eliminated and working hours devoted to safety could have been reduced by 12%. These conditions could have given the same results.

Input and output efficiency of urban agglomerations in China using DEA multi-stage model

In this study, we apply the data envelopment analysis(DEA) model to quantitatively measure the input and output efficiency of 19 urban agglomerations in China from 2011 to 2016. The results show that the input and output efficiency of urban agglomerations is relatively not high, only a small number of that reach the optimal DEA efficiency. It is clearly revealed that there are the regions from the east that presents the better performance, followed by regions from the central and the west. The peer counts show that Zhusanjiao is taken into account 12 times which shows the importance here of the Zhusanjiao model.Considering the values for radial movements and the slack movements, respective urban agglomeration has their improving orientation towards the capital slack, the labor slack or the land slack. It offers a scientific decision-making of for healthy urbanization and high quality development.

A Study on Input-Output Efficiency of Citrus in Jiangxi Province

This paper analyzes the citrus input-output efficiency by using the DEA-Malmquist productivity index methods based on the data of six counties in Jiangxi Province from 2010 to 2013.The result shows that TFP of Jiangxi citrus is at low level overall,but the development is rapid.Technological progress is the driving force to promote productivity growth.Based on the static analysis study of six counties in 2013,it is found that the available input factors on the whole are in an ideal condition,and the citrus input factors in a few counties are redundant.Therefore,according to the results,the following policy recommendations are proposed:speeding up the intensive production of citrus in Jiangxi Province,to maximize the scale effect;adjusting the input ratio of various factors of production,so as to improve the citrus input-output efficiency.

An application of data envelopment analysis to investigate the efficiency of lumber industry in northwestern Ontario,Canada

This study aims at exploring the technical efficiency of lum- ber industry in northwestern Ontario, Canada using data envelopment analysis （DEA）. The DEA model analyzes relative technical efficiency of lumber mills with disproportionate inputs and outputs by dividing the 10- year time series data, for inputs and outputs of 24 lumber mills, over two periods （1999-2003 and 2004-2008）. Four inputs, namely, material （log volume）, labour （man-hours）, two types of energy （hog-fuel and electric- ity）, and one output （lumber volume） are used in this study. The trend analysis shows an annual reduction of 10%, 13% and 13% for lumber output, log consumption （input） and number of employees, respectively, during the period 1999-2008. The results from DEA with two scenarios with energy inputs and without energy inputs, for the two periods are found to be mixed and interesting. While some mills have improved their performance in terms of best use of available scarce inputs in the second period, some have shown negative per cent change in efficiency. In the with energy input and the without energy input scenario, some of the mills show a reduction in efficiency in the second period from the first period, with the highest estimated reductions of-13.9% and -47.6%, respectively. A possible explanation for these negative performances of mills in the latter period is the decline in production in the second period compared to the first period, where these mills were not able to adjust their inputs （mostly labour） as proportional lay-offs might not have been possible. These results provide policy makers and industry stakeholders with an improved understanding of the trends of efficiency and employ- ment as well as reallocation opportunities of future inputs in order to increase benefits from this sector.

Determining the Technical Efficiency of Specialty Ophthalmology Hospital Using SFA and DEA: 2009-2011

Introduction: During the last decade, the health sector of many countries in general has been faced significantly with the increase of health care costs and in particular with the growth in hospital costs, that a significant part of it is due to the inefficient use of resources. The present study has been calculated the technical efficiency of the Specialty Ophthalmology Hospital of Tehran University of Medical Sciences by the comprehensive data analysis methods and stochastic frontier analysis. Methods: In this article, the technical efficiency of the Specialty Ophthalmology Hospital of Tehran University of Medical Sciences has been calculated by the years of 2009 to 2011, by the comprehensive data analysis methods and stochastic frontier analysis. For this purpose, the form of input-oriented data envelopment analysis approach was used by assuming the variable Productivity to scale and stochastic frontier analysis method and from the five output, the occupied bed days, outpatient admissions, inpatient admissions, inpatient days and bed occupancy factor, and from the six output, it means active beds, number of doctors, nurses, and other personnel, budget and equipment costs were used for the study. For data analyzing, Deap software, edit 1/2 and Frontier edit 1/4, was used. Result: The results of a comprehensive data analysis method showed: 1) The capacity of improving technical efficiency in the studied sector is 34% (average technical efficiency is 0.663 parts);and 2) some of the sectors are met the excess inputs (factors of production). Technical efficiency using stochastic frontier analysis was equal to 0.937. In fact, the stochastic frontier analysis showed the inefficiency is less than the actual value. Conclusion: Reducing excess capacity factors (factors of production) should be conducted in the form of a comprehensive plan and by considering all regarded aspects, that this reduction plays a major role in the hospital and health sector costs reduction.

Research on a High-Efficiency LED Driving Circuit Based on Buck Topology

A high efficiency LED(Light Emitting Diode) driver based on Buck converter, which could operate under a wide AC input voltage range(85V^265V) and drive a series of high power LEDs, is presented in this paper. The operation principles, power loss factors of the LED driver in this study are analyzed and discussed in detail and some effective ways to improve efficiency are proposed through system design considerations. To verify the feasibility, a laboratory prototype is also designed and tested for an LED lamp which consists of 16 LUMILEDS LEDs in series. Experimental results show that a high efficiency of 92% at I0=350mA can be achieved and the studied driver might be practical for driving high power LEDs. In the last, the overall efficiency over 90% is gained through some experiments under variable input and output voltages and verifies the validity of the designed driver.

Energy efficiency and economic growth of China:1953-2006

Energy plays an important role in the economic life. With the rapid development of economy, the constraint of energy on the sustainable development of economy is becoming more and more obvious. This paper just studies the factors influencing energy efficiency of China and the relationship between energy efficiency and China's economic growth. By using time series multivariable linear regression methods with China's relevant data from 1953 to 2006, this paper constructs the regression model to analyze the factors that would impact energy efficiency. After that, a regression model of China's real output to capital, labor and energy efficiency is conducted to estimate the marginal contribution of every factor to the real output to prove the fundamental influence of energy eff iciency to the economic growth. In the end, some policies and recommendations are also put forward in order to improve the energy efficiency of China.

Optimization of energy efficiency for the full-duplex massive MIMO systems

The energy efficiency（EE） for the full-duplex massive multi-input multi-output（MIMO） system is investigated. Given the transmit powers of both the uplink and the downlink, the closed-form solutions of the optimal number of antennas and the maximum EE are achieved in the high regime of the signal-to-noise ratio（SNR）. It is shown that the optimal number of antennas and the maximum EE gets larger with the increase in user numbers. To further improve the EE, an optimization algorithm with low complexity is proposed to jointly determine the number of antennas and the transmit powers of both the uplink and the downlink. It is shown that, the proposed algorithm can achieve the system performance very close to the exhaustive search.

Assessing China’s regional efficiency of energy-saving and emission reduction using the target orientation approach of extended DDF model

Based on the target of energy-saving and emission reduction(ESER)in the national five-year plan in China,an extended directional distance function model(E-DDF)including undesirable input and undesirable output is proposed,and energy-saving efficiency,emission reduction efficiency,ESER efficiency are defined.Then the weighted directional distance function model is constructed for the total factors efficiency index model of ESER to reflect its dynamic change.The results show that the ESER efficiency continues to rise during the three five-year plan periods(2006-2017),and the efficiency score of the east area are higher than those of central and west area.The disparity and change of energy-saving efficiency among difference regions are not obvious,but the disparity and change of emission reduction efficiency are the main reasons for the improvement and change of ESER efficiency index.In the long run,the ESER efficiency is in a dynamic upward trend,and the effect of technological progress is more obvious compared with technical efficient index.

Toward the Energy Efficiency of Resource Allocation Algorithms for OFDMA Downlink MIMO Systems

The problem of the simultaneous multi-user resource allocation algorithm in orthogonal frequency division multiple access(OFDMA)based systems has recently attracted significant interest.However,most studies focus on maximizing the system throughput and spectral efficiency.As the green radio is essential in 5G and future networks,the energy efficiency becomes the major concern.In this paper,we develop four resource allocation schemes in the downlink OFDMA network and the main focus is on analyzing the energy efficiency of these schemes.Specifically,we employ the advanced multi-antenna technology in a multiple input-multiple output(MIMO)system.The first scheme is based on transmit spatial diversity(TSD),in which the vector channel with the highest gain between the base station(BTS)and specific antenna at the remote terminal(RT)is chosen for transmission.The second scheme further employs spatial multiplexing on the MIMO system to enhance the throughput.The space-division multiple-access(SDMA)scheme assigns single subcarrier simultaneously to RTs with pairwise“nearly orthogonal”spatial signatures.In the fourth scheme,we propose to design the transmit beamformers based on the zero-forcing(ZF)criterion such that the multi-user interference(MUI)is completely removed.We analyze the tradeoff between the throughput and power consumption and compare the performance of these schemes in terms of the energy efficiency.

基于DEA模型的安康市农业投入产出效率评价

为了解安康市现代农业发展效率状况,选取2009—2020年安康市污染治理投资总额、农业固定资产投资额、耕地面积和乡村劳动力资源总数4个农业投入指标,以及农业总产值和农业人均生产值2个农业产出指标,采用数据包络分析(data envelopment analysis,DEA)模型中的BCC模型进行效率分析。结果表明,安康市农业投入产出效率只有2020年的DEA模型是有效的,但从2009年开始,综合效率总体呈现上升趋势;从投入冗余率与产出不足率可以看出,安康市农业总产值基本不存在产出不足的现象,除2020年外,其余各年份在污染治理投资总额、农业固定资产投资额、耕地面积和乡村劳动力资源总数的投入在不同程度都存在冗余,投入结构不合理造成DEA模型无效。

技术融合与企业出口产品质量--来自中国工业企业的经验证据

技术融合是提高科技成果转化和产业化水平、实现经济高质量发展取得新突破的关键。推动中国迈向贸易强国的背景下,研究技术融合究竟如何影响中国企业出口产品质量的问题尤为重要。使用2000—2013年中国工业企业数据作为研究样本,构建固定效应模型,系统考察技术融合对企业出口产品质量的影响及作用机制。研究发现,技术融合的深化显著提升了企业出口产品质量。异质性分析表明,技术融合对企业出口产品质量的提升作用在非国有企业、非外资企业以及沿海企业中表现更为突出。机制检验发现,技术融合深化能够提升企业全要素生产率以及固定成本投入效率,最终实现企业出口产品质量升级;市场化程度以及政府支持力度会在技术融合提升企业出口产品质量过程中发挥正向调节作用。因此,应进一步深化技术融合,搭建高效的交流合作平台,加速优质要素资源流动,重点培育本土企业自主创新能力,实现出口产品质量升级。

中国高技术产业科技成果转化效率和投入产出结构分析

为进一步探究我国高技术产业中各个行业科技成果转化效率及其投入产出结构,利用2009—2021年的面板数据,采用超效率SBM模型对中国高技术产业科技成果转化效率进行研究,分析中国高技术产业15个行业的科技成果转化综合效率和投入冗余、产出不足,为高技术产业及其行业调整优化投入产出结构、提升科技成果转化效率提供基础。研究发现,中国高技术产业科技成果转化效率呈现出先下降再波动上升的趋势,各行业均呈现波动上升的良好发展趋势,但整体水平不高,行业间差距较大;行业间R&D活动人员、技术改造经费和科技活动经费中的政府资金投入冗余,新产品销售收入产出不足问题突出。基于上述结论提出根据行业特点,先转换再精减冗余人员、重视科研人员再教育、调整资金分配结构、转变政府干预方式、建立健全多渠道合作机制、注重市场需求导向促进理论成果市场化等建议,以进一步提升高技术产业科技成果转化效率。

考虑投入产出的常规公交调度绩效回溯性动态评价

实时调度因其灵活性在公交运营组织中发挥着重要决策作用。现行调度(员)绩效评价虽然能够考核行车计划执行情况,却忽略了在乘客体验和企业投入产出层面对调度效果考查,也不支持回溯过往调度实施效果。为使调度员能够精准提升调度技能和绩效、解决调度决策滞后造成的运能浪费等问题并提高乘客满意度,从投入产出及回溯性动态评价2个维度提出基于三阶段Super-SBM(super-efficiency slack-based measurement)模型的常规公交调度绩效评价方法,考虑路况及客流对调度效果的影响,在现行指标基础上从乘客角度增加运营速度、候车时间变化率及满载率标准差3项产出指标,构建评价体系。对2条上海公交线路的实际调度进行回溯性评价,验证了本文评价方法能准确区分调度效果差异。结果表明,高峰时段灵活的调度策略比在平峰能产生更明显的效益,且调度策略在不同时空场景呈现差异化适用性。通过回溯分析历史调度记录的绩效,一方面可以针对各场景为调度员提供调度决策支持,另一方面可为基于机器学习的公交实时调度策略生成技术挑选合适的学习样本,从而提升常规公交运营组织效率。

基于SWIPT的无小区大规模MIMO-NOMA系统能量效率研究

无小区大规模多输入多输出(Multiple-Input Multiple-Output,MIMO)与非正交多址接入(Non-Orthogonal Multiple Access,NOMA)都是未来6G的使能技术。无线携能通信(Simultaneous Wireless Information and Power Transfer,SWIPT)技术在进行信息解码的同时收集能量,与无小区大规模MIMO-NOMA优势互补。文中基于SWIPT研究无小区大规模MIMO-NOMA系统中的能量效率问题,通过联合优化功率分配系数和SWIPT的时隙切换(Time Switching,TS)系数,提高系统的能量效率。为了最大化能量效率,采用布谷鸟算法设计功率分配系数。考虑一种特殊情况,将所有终端的TS系数设置相同,进而推导了最佳TS系数的封闭表达式。仿真结果表明,相较于几种已有方案,文中提出的优化方案可以显著提升系统的能量效率。

ESG责任履行与企业技术创新提质增效

本文以2009~2022年沪深A股上市企业为研究样本,基于资源依赖理论和信号传递理论,考察了企业ESG履责对企业创新的影响及异质性特征,并对企业技术创新资源投入、资源约束、市场关注在其中的中介传导机制以及数字化转型的调节机制进行了检验。研究发现:(1)企业ESG履责对企业技术创新质量和创新效率均有着显著正向影响,对企业创新有着“提质增效”的重要作用;(2)企业ESG履责能够显著提升企业技术创新资源投入,缓解资源约束,提升市场关注,进而促进企业技术创新质量与创新效率的显著提升,资源投入、资源约束、市场关注在ESG履责对企业创新“提质增效”作用中发挥部分中介作用;(3)数字化转型能够调节ESG履责与企业技术创新间的“提质增效”作用,即企业数字化转型程度越高,企业ESG履责越能促进创新质量与创新效率的提升。

地块规模与化肥投入:减施逻辑及其证据

本文基于诱致性技术变迁理论分析地块规模约束下的化肥减施逻辑,利用2020年中国乡村振兴综合调查(CRRS)7个省(自治区)的玉米种植户数据,运用两阶段最小二乘法(two-stage least squares regression,2SLS)分析地块规模对化肥投入的影响。实证结果表明:扩大地块规模可以降低化肥投入强度,提高化肥投入效率。异质性分析发现,与小农户相比,规模农户扩大地块规模对化肥减施的影响更大;对于化肥投入强度越高、投入效率越低的农户,扩大地块规模对化肥投入的影响越大。进一步的分析发现,机械作业替代农业劳动,是扩大地块规模促进化肥减施的作用机制。