Efficient Slew-Rate Enhanced Operational Transconductance Amplifier

Today, along with the prevalent use of portable equipment, wireless, and other battery powered systems, the demand for amplifiers with a high gain-bandwidth product（GBW）, slew rate（SR）, and at the same time very low static power dissipation is growing. In this work, an operational transconductance amplifier（OTA） with an enhanced SR is proposed. By inserting a sensing resistor in the input port of the current mirror in the OTA, the voltage drop across the resistor is converted into an output current containing a term in proportion to the square of the voltage, and then the SR of the proposed OTA is significantly enhanced and the current dissipation can be reduced. The proposed OTA is designed and simulated with a 0.5μm complementary metal oxide semiconductor（CMOS） process. The simulation results show that the SR is 4.54V/μs, increased by 8.25 times than that of the conventional design, while the current dissipation is only 87.3%.

Operation Efficiency Optimisation Modelling and Application of Model Predictive Control

The efficiency of any energy system can be charaterised by the relevant efficiency components in terms of performance, operation, equipment and technology(POET). The overall energy efficiency of the system can be optimised by studying the POET energy efficiency components. For an existing energy system, the improvement of operation efficiency will usually be a quick win for energy efficiency. Therefore, operation efficiency improvement will be the main purpose of this paper. General procedures to establish operation efficiency optimisation models are presented. Model predictive control, a popular technique in modern control theory, is applied to solve the obtained energy models. From the case studies in water pumping systems, model predictive control will have a prosperous application in more energy efficiency problems.

Effects of aggregating forests, establishing forest road networks, and mechanization on operational efficiency and costs in a mountainous region in Japan

We investigated forest road networks and forestry operations before and after mechanization on aggregated forestry operation sites. We developed equations to estimate densities of road networks with average slope angles, operational efficiency of bunching operations with road network density, and average forwarding distances with operation site areas. Subsequently, we analyzed the effects of aggregating forests, establishing forest road networks, and mechanization on operational efficiency and costs. Six ha proved to be an appropriate operation site area with minimum operation expenses. The operation site areas of the forest owners＇ cooperative in this region aggregated approximately 6 ha and the cooperative conducted forestry operations on aggregated sites. Therefore, 6 ha would be an appropriate operation site area in this region. Regarding road network density, higher-density road networks increased operational expenses due to the higher direct operational expenses of strip road establishment. Therefore, road network density should be reduced to approximately 200 m.

Operational efficiencies and costs of an arm roll forwarder: A case study at Nasu in Tochigi Prefecture, Japan

We investigated a developed arm roll forwarder at Nasu in Tochigi Prefecture, Japan. An arm roll forwarder can only load a steel container that has been fully loaded with logs beforehand, and can later unload such a container. Such a forwarder can shorten the loading and untoading times and improve operational efficiency. We examined two operation systems with an arm roll forwarder and a forwarder. In the first system the loading was done with a grapple-loader. In the second system the loading was done with a processor. The loading times of an arm roll forwarder were significantly tess than those of a forwarder. Because the optimal cycle times （excluding the waiting times for an arm roll for- warder） were significantly reduced, the costs of using an arm roll for- warder are lower, although the loading capacity was small and the hourly operation cost was high. The maximum operational efficiencies varied depending on forwarding distances. The second operation system with an arm roll forwarder exhibited the best operational efficiency within a 1,580-m forwarding distance, and beyond that distance it exhibited the highest operational efficiency when a forwarder was used. Similarly, the cost of operation of the system with an arm roll forwarder was the lowest within a 1,130-m forwarding distance, and beyond that distance the cost was the lowest when using the forwarder. Therefore, the arm roll for- warder is effective within a certain forwarding distance.

Operation Efficiency and Influencing Factors of Listed Companies of Swine Industry:Empirical Analysis Based on Data of 16 Listed Companies in 2010-2014

Listed companies of the swine industry,as an important form of agricultural industrialized operation,are typical representatives of large-scale production and the level of their operation efficiency exerts a direct influence on the healthy development of the swine industry.Using the DEA-based Malmquist method,this paper made a static and dynamic evaluation of the operation efficiency of 16 listed companies in China's swine industry in 2010-2014. It obtained following results:( i) The overall efficiency of listed companies of China's swine industry remained at high level and the development trend was excellent.( ii) Different types of enterprises had difference in the overall efficiency,pure technical efficiency and scale efficiency. In general,pig feed processing companies had the best performance,followed by slaughtering and deep processing companies,and swine breeding companies were the worst.( iii) The total factor productivity characterized by the Malmquist index declined year by year in 2010-2013 and was improved in 2014,mainly due to technological progress.( iv) The total asset turnover ratio,equity concentration,and R & D management level had a significantly positive impact on the operation efficiency of listed companies in the swine industry,while the human capital had a significantly negative impact.

An Analysis of Operational Efficiency of Agricultural Insurance Agency:Based on Three-Stage DEA Model

From the perspective of agricultural insurance agency,this paper focuses on the study of operational efficiency of agricultural insurance agency,and analyzes the operational efficiency of agricultural insurance agency and its influencing factors,in order to improve the operational efficiency of agricultural insurance agency,better supply agricultural insurance and achieve the policy effect of agricultural insurance.The results of this paper are as follows:( i) Either comprehensive operational efficiency or scale efficiency of Chinese-funded agency is higher than that of foreign-funded agency,but its pure technical efficiency is lower than that of foreign-funded agency,indicating that the managerial decision ability of Chinese-funded agency is weaker than that of foreign-funded agency,and needs to be improved;( ii) The operational efficiency of professional agricultural insurance agency is higher than that of comprehensive agricultural insurance agency,and the agricultural insurance agency is greatly affected by environmental factors;( iii) The operating time of agricultural insurance agency is proportional to its operational efficiency;( iv) The quality of employees is positively correlated with the capital and cost input difference,but negatively correlated with the difference in the number of employees. Therefore,it is necessary to pay attention to the improvement of employees' working efficiency while laying emphasis on employees' quality.

The Correlation of Hospital Operational Efficiency and Average Length of Stay in China: A Study Based on Provincial Level Data

Objective: To measure the hospital operation efficiency, study the correlation between average length of stay and hospital operation efficiency, analyze the importance of shortening average length of stay to the improvement of the hospital operation efficiency and put forward relevant policy suggestion. Methods: Based on China provincial panel data from 2003 to 2012, the hospital operation efficiencies are calculated using Super Efficiency Data Envelopment Analysis model, and the correlation between average length of stay and hospital operation efficiency is tested using Spearman rank correlation coefficient test. Results: From 2003 to 2012, the average of national hospital operation efficiency was increasing slowly and the hospital operations were inefficient in most of the areas. The national hospital operation efficiency is negatively correlated to the average length of stay. Conclusion: Measures should be taken to set average length of stay in a scientific and reasonable way, improve social and economic benefits based on the improvement of efficiency.

The Operation Efficiency Evaluation for Listed Companies of China Aviation Industry Based on DEA and Malmquist Index

The data envelopment analysis （DEA） is used to evaluate operation efficiency of 17 listed companies in China aviation industry from 2006 to 2011, and make longitudinal analysis for the operation efficiency. In addition, the reason of changing efficiency is dynamically evaluated by Malmquist productivity index. The empirical results show that average operation efficiency of 17 listed companies in China aviation industry is less than 1, which means that the operation activities of aviation industry exist diseconomies characteristic, technological progress efficiency is a major influenced factor

2013—2019年上海市市级医院运行效率及影响因素

目的分析2013—2019年上海市市级医院的运行效率及其影响因素,为医院提质增效提供依据。方法以上海市12家市级综合医院与18家市级专科医院为研究对象,运用DEA-BCC模型、Malmquist指数模型与Tobit回归模型测算样本医院的效率及其动态变化情况,并分析其影响因素。结果2013—2019年,样本综合医院的全要素生产率与技术进步指数增长,技术效率指数下降,样本专科医院的全要素生产率、技术进步指数、技术效率均增长。进一步分析发现,卫生技术人员占比、床位使用率、院区总数与技术效率正相关,31 d再入院率、药占比与技术效率负相关。结论样本医院运行效率较高,但多数医院处于规模不经济状态,应调整发展规模,优化资源配置。样本医院的全要素生产率提高主要依靠技术进步推动,建议加强人才建设,提高技术创新能力。样本医院运行效率受多重因素影响,制定战略目标时应结合实际情况进行统筹规划。

Effect of blockchain technology initiatives on firms’market value

Despite blockchain’s potential to transform corporations by providing new ways of organizing business processes and handling information,extant research pays inadequate attention to how and under what conditions blockchain technology provides additional financial value for shareholders.Drawing on the efficient market hypothesis and signaling theory,we examined the relationship between firms’blockchain use,development announcements,and stock market reactions.We used the event study methodology to analyze a sample of blockchain projects initiated by US firms between 2016 and 2019.The sample contains 114 firm-event observations.The findings show that the average abnormal return over a 2 days event period(including the day of the announcement and the day after the announcement)was positive.This positive stock market reaction is even more substantial when firms announce blockchain projects that focus on saving cost or time.Our findings also indicate that blockchain announcements tend to elicit more positive market reactions from smaller firms.We analyzed 249 firm-event observations containing firms from around the world and conclude that blockchain technology has a non-significant long-term impact on operating performance.The contingency approach adopted in our research provides advice for selecting the right mix of blockchain investment initiatives that is most suitable for a given organizational context.

Efficient dual-wavelength operation of Nd:LYSO laser by diode pumping aimed toward the absorption peak

By aiming the pump wavelength of the laser （Ndo.oo5Luo.4975Yo.4975）2SiO5 （Nd：LYSO） crystal 1 079 nm is obtained. The maximum output power corresponding to an optical conversion efficiency of diode to the absorption peak at 811 an efficient dual-wavelength operation at 1 is 702 mW when the incident pump power is 27.7% and a slope efficiency of 37.0% of the 075 and 2.53W,

Highly efficient CW laser operation in 4 at. % Tm^(3+) and 4 at. % Y^(3+) codoped CaF_2 crystals

Tm：CaF2 and Tm;Y：CaF2 single crystals were prepared by the temperature gradient technique. The spectral properties of Tm;Y：CaF2 single crystals were investigated and compared with those of Tm：CaF2. It was demonstrated that codoping with Y3＋ ions could efficiently improve the spectroscopic properties. Tm;Y：CaF2 crystals have larger absorption cross-sections at the pumping wavelength, larger mid-infrared stimulated emission cross-sections, and much longer fluorescence lifetimes of the upper laser level（Tm3＋：3H4 level） than Tm：CaF2 crystals. Continuous-wave（CW） lasers around 1.97 μm were demonstrated in 4.0 at. % Tm,4.0 at. % Y：CaF2 single crystals under 792 nm laser diode（LD） pumping. The best laser performance has been demonstrated with a low threshold of 0.368 W, a high slope efficiency of 54.8%, and a maximum output power of 1.013 W.

Study of Efficiency of Agricultural Listed Companies Based on DEA Model

As leading enterprises supporting the agricultural development,agricultural listed companies play a great role,thus the study on their operating efficiency will have a strong demonstration effect. Using the data envelopment analysis( DEA) model,the operating efficiency of 20 agricultural listed companies was compared and analyzed. The results indicated that the overall efficiency of the agricultural listed companies is low. In agricultural listed companies with low or moderate overall efficiency,some agricultural companies are affected by the pure technical efficiency or scale efficiency,while other companies are affected by both factors,and accompanied with the increasing or decreasing efficiency along with the scale. Through in-depth analysis,it concluded that nine companies affected by pure technical efficiency have different degree of input redundancy or output deficiency. On this basis,it came up with pertinent recommendations for improvement.

Optimization in the Selection of Sugarcane Varieties in a Sucro Energy Plant Located in the State of Sao Paulo,Brazil

Sugarcane crops have undergone several changes with the intensification of agricultural machinery in Brazil in the last years.This occurs,mainly,due to the transfer of the semi-mechanized system to the mechanized one during harvest operations.Thus,studies are needed on the optimization of sugarcane production in relation to mechanized processes,since it is necessary to verify the adaptability of sugarcane varieties to the mechanization of the plantation.This study aimed to develop and apply a mathematical model of optimization to select sugarcane varieties that maximize production and meet the quality standards required by the industry for sugar and fiber contents.The data were collected in a sugarcane mill located in the interior of S?o Paulo state.The result obtained by the optimization process evinced an increase of 16.65%when compared to the productivity of the initial scenario.

Coordinated Chance-constrained Optimization of Multi-energy Microgrid System for Balancing Operation Efficiency and Quality-of-service

To enhance the flexible interactions among multiple energy carriers,i.e.,electricity,thermal power and gas,a coordinated programming method for multi-energy microgrid(MEMG)system is proposed.Various energy requirements for both residential and parking loads are managed simultaneously,i.e.,electric and thermal loads for residence,and charging power and gas filling requirements for parking vehicles.The proposed model is formulated as a two-stage joint chance-constrained programming,where the first stage is a day-ahead operation problem that provides the hourly generation,conversion,and storage towards the minimization of operation cost considering the forecasting error of photovoltaic output and load demand.Meanwhile,the second stage is an on-line scheduling which adjusts the energy scheme in hourly time-scale considering the uncertainty.Simulations have demonstrated the validity of the proposed method,i.e.,collecting the flexibilities of thermal system,gas system,and parking vehicles to facilitate the operation of electrical networks.Sensitivity analysis shows that the proposed scheme can achieve a compromise between the operation efficiency and service quality.

Comparing Operational Efficiency of Mobile Operators in Brazil, Russia, India and China

Using partial factor productivity and data envelopment analysis approaches, this study measures and compares the operational efficiency of the 10 dominant mobile operators in Brazil, Russia, India and China （BRIC） between 2002 and 2006. The results of data envelopment analysis indicate that the two leading Brazilian mobile operators, Vivo and TIM, are fully efficient throughout the entire period of study, however, Indian mobile operators are the least efficient among BRIC operators. Interestingly, the findings of this study verify that full operational efficiency can be achieved by operators with large revenues, such as China Unicorn, and by other, y with medium and small revenues, such as Hvo, TIM and Oi. Partial faetor productivity demonstrates that 3 of the 4 Brazilian mobile operators, Vivo, TIM and Oi, have remarkable productivity ratios, and that the state-owned operator, China Unicom, has the highest revenue per capital expenditure among BRIC operators. In contrast, Indian mobile operators ＇productivity ratios are generally low compared to other BRIC mobile carriers.

Study on operation strategy and load forecasting for distributed energy system based on Chinese supply-side power grid reform

This study focuses on the development and analysis of a real-time updated operations strategy of a distributed energy system(DES).Owing to the relevant Chinese policy of electrical transmission and distribution,combined cooling,heating,and power system(CCHP)and photovoltaic(PV)systems are not currently allowed.However,with the Chinese supply-side power grid reform,the permissions for connections between DESs and utilities are gradually evolving.By performing building simulation and using mixed integer linear programming(MILP),a real-time updated operation strategy of a DES is established.Then,considering the DES from Tianjin Eco-city as a case study,a comparative analysis between this updated strategy and the current operation strategy is performed by evaluating three factors:economic efficiency,energy consumption,and CO2 emission.The results show that the updated strategy can reduce 29.12%of electricity time-of-use cost,10.11%of total fuel consumption,and 18.40%of CO2 emission during the cooling season.Besides,a method of“rolling load forecasting”for DES by using Support vector regression machine(SVR)is proposed and discussed.The testing shows that the Mean Absolute Percentage Error(MAPE)is below 7.5%.And when the training sample is large,the particle swarm optimization algorithm can be used to shorten the modeling time of the air conditioning load forecasting model.

A Review and Outlook on Predictive Cruise Control of Vehicles and Typical Applications Under Cloud Control System

With the application of mobile communication technology in the automotive industry,intelligent connected vehicles equipped with communication and sensing devices have been rapidly promoted.The road and traffic information perceived by intelligent vehicles has important potential application value,especially for improving the energy-saving and safe-driving of vehicles as well as the efficient operation of traffic.Therefore,a type of vehicle control technology called predictive cruise control(PCC)has become a hot research topic.It fully taps the perceived or predicted environmental information to carry out predictive cruise control of vehicles and improves the comprehensive performance of the vehicle-road system.Most existing reviews focus on the economical driving of vehicles,but few scholars have conducted a comprehensive survey of PCC from theory to the status quo.In this paper,the methods and advances of PCC technologies are reviewed comprehensively by investigating the global literature,and typical applications under a cloud control system(CCS)are proposed.Firstly,the methodology of PCC is generally introduced.Then according to typical scenarios,the PCC-related research is deeply surveyed,including freeway and urban traffic scenarios involving traditional vehicles,new energy vehicles,intelligent vehicles,and multi-vehicle platoons.Finally,the general architecture and three typical applications of the cloud control system(CCS)on PCC are briefly introduced,and the prospect and future trends of PCC are proposed.