It was suggested by Pantanen that the mean squared error may be used to measurethe inefficiency of the least squares estimator.Styan and Rao et al.discussed thisinefficiency and its bound later.In this paper we propos...It was suggested by Pantanen that the mean squared error may be used to measurethe inefficiency of the least squares estimator.Styan and Rao et al.discussed thisinefficiency and its bound later.In this paper we propose a new inefficiency of the leastsquares estimator with the measure of generalized variance and obtain its bound.展开更多
Scale-controlling and technology-upgrading measures are considered effective for mitigating vehicle exhaust emissions.This study investigated the impacts of fuel consumption and vehicle quantities on the total factor ...Scale-controlling and technology-upgrading measures are considered effective for mitigating vehicle exhaust emissions.This study investigated the impacts of fuel consumption and vehicle quantities on the total factor inefficiency in China’s highway transport sector during 2011-2015,based on the Bounded Adjusted Measure Data Envelopment Analysis(BAM-DEA)model combined with natural and managerial disposability scenarios.The results showed that the average global inefficiency(GIE)score of the exhaust emissions(CO,HC,NOx,and PM)was 0.41 under the assumption of natural disposability and 0.23 in the managerial disposability situation.Moreover,the main causes of total factor inefficiency scores from the perspective of natural disposability were road length,fuel consumption,and exhaust emissions,whereas those from a managerial disposability perspective were road length and exhaust emissions.These two results suggested that environmental efficiency can be promoted by increasing the quantities of clean-energy vehicles and high-quality gasoline/diesel consumption.In terms of the spatial distribution of GIE,the scores showed a decreasing trend from China’s northwestern inland regions to its southeastern coastal regions under both natural and managerial disposability.Environmental efficiency in some provinces(such as Yunnan)demonstrated good progress under managerial disposability,but other regions did not(such as Hebei and Ningxia).Thus,each province should choose appropriate strategies regarding vehicle quantities and fuel consumption according to the technical inefficiency scores of differing disposability situations.展开更多
We used the directional output distance function to derive estimates of green inefficiency, shadow prices, and waste costs of three wastes (waste water, waste gas, and solid waste) for thirty regions in China during t...We used the directional output distance function to derive estimates of green inefficiency, shadow prices, and waste costs of three wastes (waste water, waste gas, and solid waste) for thirty regions in China during the 1996-2003 periods. There is an upward trend in green inefficiency in Chinese regions from 1996 to 2003. The green inefficiency score in west area is the lowest but in central and east areas are higher. The costs of wastes have an upward trend in east and central areas but downward trend in west area in the last two observation years.展开更多
Android applications are becoming increasingly powerful in recent years. While their functionality is still of paramount importance to users, the energy efficiency of these applications is also gaining more and more a...Android applications are becoming increasingly powerful in recent years. While their functionality is still of paramount importance to users, the energy efficiency of these applications is also gaining more and more attention. Researchers have discovered various types of energy defects in Android applications, which could quickly drain the battery power of mobile devices. Such defects not only cause inconvenience to users, but also frustrate Android developers as diagnosing the energy inefficiency of a software product is a non-trivial task. In this work, we perform a literature review to understand the state of the art of energy inefficiency diagnosis for Android applications. We identified 55 research papers published in recent years and classified existing studies from four different perspectives, including power estimation method, hardware component, types of energy defects, and program analysis approach. We also did a cross-perspective analysis to summarize and compare our studied techniques. We hope that our review can help structure and unify the literature and shed light on future research, as well as drawing developers' attention to build energy-efficient Android applications.展开更多
Subject Code:C06 Under the support of the National Natural Science Foundation of China,the research group led by Prof.Zhang Liangran(张亮然)from Shandong University,collaborated mainly with the research group led by P...Subject Code:C06 Under the support of the National Natural Science Foundation of China,the research group led by Prof.Zhang Liangran(张亮然)from Shandong University,collaborated mainly with the research group led by Prof.Nancy Kleckner from Harvard University,has demonstrated that human female meiosis has展开更多
Motor imagery brain–computer interfaces(MI-BCIs)have great potential value in prosthetics control,neurorehabilitation,and gaming;however,currently,most such systems only operate in controlled laboratory environments....Motor imagery brain–computer interfaces(MI-BCIs)have great potential value in prosthetics control,neurorehabilitation,and gaming;however,currently,most such systems only operate in controlled laboratory environments.One of the most important obstacles is the MI-BCI inefficiency phenomenon.The accuracy of MI-BCI control varies significantly(from chance level to 100%accuracy)across subjects due to the not easily induced and unstable MI-related EEG features.An MI-BCI inefficient subject is defined as a subject who cannot achieve greater than 70%accuracy after sufficient training time,and multiple survey results indicate that inefficient subjects account for 10%–50%of the experimental population.The widespread use of MI-BCI has been seriously limited due to these large percentages of inefficient subjects.In this review,we summarize recent findings of the cause of MI-BCI inefficiency from resting-state brain function,task-related brain activity,brain structure,and psychological perspectives.These factors help understand the reasons for inter-subject MI-BCI control performance variability,and it can be concluded that the lower resting-state sensorimotor rhythm(SMR)is the key factor in MI-BCI inefficiency,which has been confirmed by multiple independent laboratories.We then propose to divide MI-BCI inefficient subjects into three categories according to the resting-state SMR and offline/online accuracy to apply more accurate approaches to solve the inefficiency problem.The potential solutions include developing transfer learning algorithms,new experimental paradigms,mindfulness meditation practice,novel training strategies,and identifying new motor imagery-related EEG features.To date,few studies have focused on improving the control accuracy of MI-BCI inefficient subjects;thus,we appeal to the BCI community to focus more on this research area.Only by reducing the percentage of inefficient subjects can we create the opportunity to expand the value and influence of MI-BCI.展开更多
The stock market in the form of the S&P 500 is estimated to be inefficient in 13%to 30%of the time since 1963.This is contrary to the theory of efficient capital markets,but in accordance with Samuelson’s Dictum,...The stock market in the form of the S&P 500 is estimated to be inefficient in 13%to 30%of the time since 1963.This is contrary to the theory of efficient capital markets,but in accordance with Samuelson’s Dictum,which posits that the stock market is micro efficient,but macro inefficient.I develop a new model to measure potential inefficiency at macro level.Inefficiency in price(P)is driven by earnings(EPS)and/or valuation(P/E).At the peak of the TMT-bubble in 1999/2000,both factors were in play,while only earnings assumptions were inefficient before the Great Financial Crisis in 2008/09.The model developed show expected results in terms of relative efficiency for Developed vs.Emerging Markets and for Dow Jones vs.Nasdaq.Parts of academia seems to accept a different definition of market efficiency at micro level compared to macro level.At macro level,a standard“price vs.fair value”definition seems to be generally accepted,while at micro level,a relative“price vs.price”definition seems to be broadly used.The latter way of thinking has historically contributed to price bubbles.Numerous examples of stock prices that deviate significantly from their fair value in days,weeks and months and doubtful methods for measuring efficiency at micro level cast doubt about the micro efficiency claim part of Samuelson’s Dictum.展开更多
Advance development of wireless technologies and micro-sensor systems have enabled Wireless Sensor Network (WSN) to emerge as a leading solution in many crucial sensor-based applications. WSN deploys numerous resource...Advance development of wireless technologies and micro-sensor systems have enabled Wireless Sensor Network (WSN) to emerge as a leading solution in many crucial sensor-based applications. WSN deploys numerous resource-constrained sensor nodes which have limited power supply, memory and computation capability in a harsh environment. Inefficient routing strategy results in degraded network performance in terms of reliability, latency and energy efficiency. In this paper, a cross-layer design, Contention-based MAC and Routing protocol is proposed, termed Contention/SNIR-Based Forwarding (CSBF) protocol. CSBF utilizes the geographical information of sensor nodes to effectively guide the routing direction towards destination node, thereby enhancing reliability. Furthermore, Signal-to-Noise-plus-Interference Ratio (SNIR) metric is used as a routing parameter to guarantee high quality link for data transmission. A Contention-Winner Relay scheme is utilized to reduce the delays caused by the contention procedure. Energy efficiency is also improved by introducing sleep mode technique in CSBF. The simulation work is carried out via OMNeT++ network simulator. The performance of CSBF is compared with other existing routing protocols such as AODV and DSDV in terms of packet delivery ratio (PDR), average end-to-end (ETE) delay and energy consumption per packet. Simulation results highlight that CSBF outperforms AODV and DSDV protocols in respect of PDR and energy efficiency. CSBF also has the most consistent overall network performance.展开更多
This paper presents a case study on the repair of a mechanical component of an overhead crane.The problem was initially identified through on-site inspection and analysis of the crane’s performance.The mechanical par...This paper presents a case study on the repair of a mechanical component of an overhead crane.The problem was initially identified through on-site inspection and analysis of the crane’s performance.The mechanical part was found damaged,leading to safety concerns and operational inefficiencies.The paper details the process of diagnosing the issue,developing a repair plan,and executing the repair work.The repair plan involved replacing the damaged component with a new one and conducting additional maintenance work to ensure optimal performance.The paper also discusses the outcomes of the repair work,which led to improved safety and increased efficiency of the overhead crane.The case study provides insights into the importance of regular maintenance and on-site inspections in ensuring the safe and efficient operation of mechanical systems.展开更多
This paper provides empirical evidence that improved supplemental irrigation (ISI) can be justified on both environmental and economic grounds. Results of a stochastic frontier model which explicitly and simultaneousl...This paper provides empirical evidence that improved supplemental irrigation (ISI) can be justified on both environmental and economic grounds. Results of a stochastic frontier model which explicitly and simultaneously accounts for technical inefficiency and production risk applied to data collected from 513 wheat farms in the rainfed areas of Syria show that the typical adopter farmer obtained yield and productive efficiency gains of 6% and 7% respectively. A stochastic dominance criterion also showed that the adopter farmers got 10% and 13% reductions in risk of obtaining yield levels below 4 tons/ha and 3 tons/ha respectively. Given its adoption level of 22.3% in 2010, ISI led to the production of 52 thousand metric tons (6%), more wheat and conservation of 120 million cubic meters of water (10%). ISI has the potential to reduce total irrigation water use by upto 45% and for further increases in yield if accompanied with sprinklers and other improved agronomic practices, thereby enhancing food security and environmental sustainability in the country. An important policy implication of these findings is that wider dissemination of ISI along with other complementary agronomic practices in postwar Syria could be a viable option to be considered by national and international efforts for the restoration and rehabilitation of agriculture in the country.展开更多
The prognostic role of cardiopulmonary exercise test (CPET) in elderly women with chronic heart failure (HF) has not yet been clarified. We assessed the incremental value of CPET variables for risk stratification in f...The prognostic role of cardiopulmonary exercise test (CPET) in elderly women with chronic heart failure (HF) has not yet been clarified. We assessed the incremental value of CPET variables for risk stratification in female HF patients with preserved or reduced left ventricular ejection fraction (LVEF). We prospectively followed up 131 female HF outpatients aged 72 [interquartile range 62 - 77] years after a symptom limited CPET. 34% had ischemic heart disease and 14% permanent atrial fibrillation, 24% were in NYHA class III. LVEF was 50% [interquartile range 36 - 62], peak oxygen consumption was 11.3 [interquartile range 9.2 - 13.5] ml/kg/min;the slope of the regression line relating ventilation to CO2 output was 33.9 [interquartile range 30.3 - 44.9];40% of patients showed exercise oscillatory breathing during CPET. During a median follow-up of 18 months [interquartile range 8 - 54], overall 39 patients (29.7%) met the combined end-point of cardiovascular mortality or HF admission using a time-to-first event approach. Moderate to severe mitral regurgitation, slope, exercise oscillatory breathing were independently associated to cardiovascular mortality or HF admission. When CPET ventilatory variables were added to clinical and echocardiographic parameters, prediction of the combined point improved significantly (AUC 0.755 (95% CI 0.662 to 0.832) vs 0.634 (95% CI 0.536 to 0.725), p = 0.016). In conclusion, among elderly female HF patients the CPET derived parameters EOB and VE/VCO2 slope emerged as strong prognostic markers, with additive predictive value to clinical and echocardiographic parameters in patients with both reduced and preserved LVEF.展开更多
The paper refers to literatures to show how the state mitigates the effects of market failures in foreign trade.The research study leads to the conclusion that state interventions are necessary in creating administrat...The paper refers to literatures to show how the state mitigates the effects of market failures in foreign trade.The research study leads to the conclusion that state interventions are necessary in creating administrative and legal conditions for facilitating trade exchange in the context of the role of transnational corporations in the global economy,as well as in reducing the adverse impact of international turbulences on the competitiveness of national entities through the use of export supporting instruments.展开更多
This paper improves the slacks-based method for estimating inefficiency,derives the criteria for the selection of the weights of output and input inefficiencies in the objective function,and creates a new nonparametri...This paper improves the slacks-based method for estimating inefficiency,derives the criteria for the selection of the weights of output and input inefficiencies in the objective function,and creates a new nonparametric method for accounting economic growth.Based on this method,the paper estimates the sources of China s economic growth from 1978 to 2013.Our findings suggest that factor input and especially capital is a major source of economic growth for China as a whole and its major regions,and that economic growth in recent years is increasingly dependent on capital.For a rather long period of time before 2005,China s northeast,central and western regions lagged behind the eastern region in terms of economic growth,and TFP and factor input are major reasons behind such regional growth disparities.Although other regions have narrowed their disparities with and even overtaken the eastern region in terms of economic growth,the key driver is the rapid increase in the contribution of factor input.Advanced technologies of eastern region should be utilized to promote TFP progress in other regions,which is vital to economic growth in these regions and China as a whole.展开更多
The transformation of quantitative variables into categories is a common practice in both experimental and observational studies. The typical procedure is to create groups by splitting the original variable distributi...The transformation of quantitative variables into categories is a common practice in both experimental and observational studies. The typical procedure is to create groups by splitting the original variable distribution at some cut point on the scale of measurement (e.g. mean, median, mode). Allegedly, dichotomization improves causal inference by simplifying statistical analyses. In this article, we address some of the adverse consequences of recoding quantitative variables into categories. In particular, we provide evidence that categorization usually leads to inefficient and biased estimates. We believe that considerable progress in our understanding of data analysis can occur if scholars follow the recommendations presented in this article. The recodification of quantitative variables as categorical is a poor methodological strategy, and scientists must stay away from it.展开更多
This paper examines the problems existing in Extensive Reading Teaching for Vocational Business English Majors and analyses the contributing factors for the time-consuming and inefficient Extensive Reading Teaching.Ba...This paper examines the problems existing in Extensive Reading Teaching for Vocational Business English Majors and analyses the contributing factors for the time-consuming and inefficient Extensive Reading Teaching.Based on the analysis,the author points out some solutions from the following several aspects:the teachers’ roles,the choice of textbooks and the organization of the class as well as the integrated design of the class activities,be carried out in the student-centered class to be practical and helpful in the Extensive Reading Teaching.展开更多
Elasticity of substitution is traditionally estimated while ignoring technical and allocative inefficiencies,which could bias the estimates.We estimate elasticity of substitution for Chinese energy-intensive sectors b...Elasticity of substitution is traditionally estimated while ignoring technical and allocative inefficiencies,which could bias the estimates.We estimate elasticity of substitution for Chinese energy-intensive sectors by incorporating these inefficiencies.The results show most of the sectors are low substitutes between input factors and stress important differences among energy-intensive sectors.Concerning the cross-price elasticity for energy,with respect to capital(labor),the sectors are mainly characterized by weak substitutability or complementary.These imply the production structure is quite rigid and capital cannot be so readily used as a substitute for energy.展开更多
Seafood plays an important role in human nutrition and its increased consumption is actively recommended for sustenance and health benefits in both developing and developed countries. In parallel to this, the public r...Seafood plays an important role in human nutrition and its increased consumption is actively recommended for sustenance and health benefits in both developing and developed countries. In parallel to this, the public receives confusing advice as to what seafood is sustainably produced and is frequently misled about the environmental impacts of fishing, especially in locations such as Australia where contemporary fishery management has a conservation and sustainability focus. It is recognised globally that Australia’s traditional fishery management driven by strict sustainability and biodiversity regulations, has achieved impressive results in managing both fish stocks and the effects of fishing on marine environments. Despite this, continued pressure from non-government organisations (NGOs) and a perpetuation of the misuse of management terms such as “overfished” is used to promote the misguided need for ever increasing fishing restrictions, most obviously in “protected areas”. This paper questions the motives of some NGOs and governments in Australia in pursuing additional restrictions on fishing which are mostly unnecessary and disproportionate to the sustainability requirements of other sources of food. This is done within the context of the global need for sustainable seafood supply and the need for effective marine conservation that addresses all threats to marine ecosystems in proportion to the magnitude of each threat.展开更多
Anchor points play an important role in data envelopment analysis theory and applications;they delineate the efficient part of the production possibility set(PPS)frontier.In this paper,we propose an approach for findi...Anchor points play an important role in data envelopment analysis theory and applications;they delineate the efficient part of the production possibility set(PPS)frontier.In this paper,we propose an approach for finding the anchor points of the PPS of the Banker,Charnes and Cooper(BCC)model.This approach is based on a variant of super-efficiency models and their duals.The necessary and sufficient conditions for the characterization of the anchor points are also provided.Finally,the applicability of the proposed model is illustrated with some numerical examples.展开更多
The wide occurrence of new-emerging pollutants and their potential environmental and ecological risks have recently caused great public concerns. The paper firstly put forward the severe problem. Then the possible mai...The wide occurrence of new-emerging pollutants and their potential environmental and ecological risks have recently caused great public concerns. The paper firstly put forward the severe problem. Then the possible main reasons were analyzed which might attribute to both the inefficient removal of wastewater treatment plants with conventional technology and ignorance of the monitor and control of new-emerging pollutants in the effluents. Also, the complexity and extreme high costs may also make the organizations sidestep the problem. Finally, possible strategies to deal with the problems were proposed. The upgrade of wastewater treatment plants was important and urgent.展开更多
With the rapid development of urbanization,the industrial parks originally located in the suburbs are gradually incorporated into the urban center.Industries that fail to follow the transformation of urban economic de...With the rapid development of urbanization,the industrial parks originally located in the suburbs are gradually incorporated into the urban center.Industries that fail to follow the transformation of urban economic development and are forced to close,or enterprises that move out without conforming to the environment,become a gray area within the city.Most of the existing assessments are conducting single assessment of some indicators,but than their actual benefits.Through the field investigation on the starting area of Handan Economic Development Zone,and the evaluation on the nature of land use,development intensity,investment and output,and idle land,inefficient land use in the park is identified.According to different evaluation results,different update and promotion methods are put forward.The research could provide a new evaluation method and idea for subsequent renewal and development of urban industrial parks.展开更多
文摘It was suggested by Pantanen that the mean squared error may be used to measurethe inefficiency of the least squares estimator.Styan and Rao et al.discussed thisinefficiency and its bound later.In this paper we propose a new inefficiency of the leastsquares estimator with the measure of generalized variance and obtain its bound.
基金support from the National Natural Science Foundation of China[Grant No.72074183]the Humanities and Social Science Foundation of Chinese Ministry of Education[Grant No.20YJC630104]the National Social Science Foundation of China[Grant No.18ZDA052].
文摘Scale-controlling and technology-upgrading measures are considered effective for mitigating vehicle exhaust emissions.This study investigated the impacts of fuel consumption and vehicle quantities on the total factor inefficiency in China’s highway transport sector during 2011-2015,based on the Bounded Adjusted Measure Data Envelopment Analysis(BAM-DEA)model combined with natural and managerial disposability scenarios.The results showed that the average global inefficiency(GIE)score of the exhaust emissions(CO,HC,NOx,and PM)was 0.41 under the assumption of natural disposability and 0.23 in the managerial disposability situation.Moreover,the main causes of total factor inefficiency scores from the perspective of natural disposability were road length,fuel consumption,and exhaust emissions,whereas those from a managerial disposability perspective were road length and exhaust emissions.These two results suggested that environmental efficiency can be promoted by increasing the quantities of clean-energy vehicles and high-quality gasoline/diesel consumption.In terms of the spatial distribution of GIE,the scores showed a decreasing trend from China’s northwestern inland regions to its southeastern coastal regions under both natural and managerial disposability.Environmental efficiency in some provinces(such as Yunnan)demonstrated good progress under managerial disposability,but other regions did not(such as Hebei and Ningxia).Thus,each province should choose appropriate strategies regarding vehicle quantities and fuel consumption according to the technical inefficiency scores of differing disposability situations.
文摘We used the directional output distance function to derive estimates of green inefficiency, shadow prices, and waste costs of three wastes (waste water, waste gas, and solid waste) for thirty regions in China during the 1996-2003 periods. There is an upward trend in green inefficiency in Chinese regions from 1996 to 2003. The green inefficiency score in west area is the lowest but in central and east areas are higher. The costs of wastes have an upward trend in east and central areas but downward trend in west area in the last two observation years.
基金supported by the Guangdong Basic and Applied Basic Research Foundation(2021A1515012297)the Shenzhen Science and Technology Innovation Commission(R2020A045)the Open Project of Guangdong Provincial Key Laboratory of High-Performance Computing(2021).
文摘Android applications are becoming increasingly powerful in recent years. While their functionality is still of paramount importance to users, the energy efficiency of these applications is also gaining more and more attention. Researchers have discovered various types of energy defects in Android applications, which could quickly drain the battery power of mobile devices. Such defects not only cause inconvenience to users, but also frustrate Android developers as diagnosing the energy inefficiency of a software product is a non-trivial task. In this work, we perform a literature review to understand the state of the art of energy inefficiency diagnosis for Android applications. We identified 55 research papers published in recent years and classified existing studies from four different perspectives, including power estimation method, hardware component, types of energy defects, and program analysis approach. We also did a cross-perspective analysis to summarize and compare our studied techniques. We hope that our review can help structure and unify the literature and shed light on future research, as well as drawing developers' attention to build energy-efficient Android applications.
文摘Subject Code:C06 Under the support of the National Natural Science Foundation of China,the research group led by Prof.Zhang Liangran(张亮然)from Shandong University,collaborated mainly with the research group led by Prof.Nancy Kleckner from Harvard University,has demonstrated that human female meiosis has
基金supported by grants from the National Natural Science Foundation of China(NSFC,Grant No.61603344,No.61961160705,No.#U19A2082)the Key Research Projects of Henan Higher Education Institutions(Project No.16A120008)
文摘Motor imagery brain–computer interfaces(MI-BCIs)have great potential value in prosthetics control,neurorehabilitation,and gaming;however,currently,most such systems only operate in controlled laboratory environments.One of the most important obstacles is the MI-BCI inefficiency phenomenon.The accuracy of MI-BCI control varies significantly(from chance level to 100%accuracy)across subjects due to the not easily induced and unstable MI-related EEG features.An MI-BCI inefficient subject is defined as a subject who cannot achieve greater than 70%accuracy after sufficient training time,and multiple survey results indicate that inefficient subjects account for 10%–50%of the experimental population.The widespread use of MI-BCI has been seriously limited due to these large percentages of inefficient subjects.In this review,we summarize recent findings of the cause of MI-BCI inefficiency from resting-state brain function,task-related brain activity,brain structure,and psychological perspectives.These factors help understand the reasons for inter-subject MI-BCI control performance variability,and it can be concluded that the lower resting-state sensorimotor rhythm(SMR)is the key factor in MI-BCI inefficiency,which has been confirmed by multiple independent laboratories.We then propose to divide MI-BCI inefficient subjects into three categories according to the resting-state SMR and offline/online accuracy to apply more accurate approaches to solve the inefficiency problem.The potential solutions include developing transfer learning algorithms,new experimental paradigms,mindfulness meditation practice,novel training strategies,and identifying new motor imagery-related EEG features.To date,few studies have focused on improving the control accuracy of MI-BCI inefficient subjects;thus,we appeal to the BCI community to focus more on this research area.Only by reducing the percentage of inefficient subjects can we create the opportunity to expand the value and influence of MI-BCI.
文摘The stock market in the form of the S&P 500 is estimated to be inefficient in 13%to 30%of the time since 1963.This is contrary to the theory of efficient capital markets,but in accordance with Samuelson’s Dictum,which posits that the stock market is micro efficient,but macro inefficient.I develop a new model to measure potential inefficiency at macro level.Inefficiency in price(P)is driven by earnings(EPS)and/or valuation(P/E).At the peak of the TMT-bubble in 1999/2000,both factors were in play,while only earnings assumptions were inefficient before the Great Financial Crisis in 2008/09.The model developed show expected results in terms of relative efficiency for Developed vs.Emerging Markets and for Dow Jones vs.Nasdaq.Parts of academia seems to accept a different definition of market efficiency at micro level compared to macro level.At macro level,a standard“price vs.fair value”definition seems to be generally accepted,while at micro level,a relative“price vs.price”definition seems to be broadly used.The latter way of thinking has historically contributed to price bubbles.Numerous examples of stock prices that deviate significantly from their fair value in days,weeks and months and doubtful methods for measuring efficiency at micro level cast doubt about the micro efficiency claim part of Samuelson’s Dictum.
文摘Advance development of wireless technologies and micro-sensor systems have enabled Wireless Sensor Network (WSN) to emerge as a leading solution in many crucial sensor-based applications. WSN deploys numerous resource-constrained sensor nodes which have limited power supply, memory and computation capability in a harsh environment. Inefficient routing strategy results in degraded network performance in terms of reliability, latency and energy efficiency. In this paper, a cross-layer design, Contention-based MAC and Routing protocol is proposed, termed Contention/SNIR-Based Forwarding (CSBF) protocol. CSBF utilizes the geographical information of sensor nodes to effectively guide the routing direction towards destination node, thereby enhancing reliability. Furthermore, Signal-to-Noise-plus-Interference Ratio (SNIR) metric is used as a routing parameter to guarantee high quality link for data transmission. A Contention-Winner Relay scheme is utilized to reduce the delays caused by the contention procedure. Energy efficiency is also improved by introducing sleep mode technique in CSBF. The simulation work is carried out via OMNeT++ network simulator. The performance of CSBF is compared with other existing routing protocols such as AODV and DSDV in terms of packet delivery ratio (PDR), average end-to-end (ETE) delay and energy consumption per packet. Simulation results highlight that CSBF outperforms AODV and DSDV protocols in respect of PDR and energy efficiency. CSBF also has the most consistent overall network performance.
文摘This paper presents a case study on the repair of a mechanical component of an overhead crane.The problem was initially identified through on-site inspection and analysis of the crane’s performance.The mechanical part was found damaged,leading to safety concerns and operational inefficiencies.The paper details the process of diagnosing the issue,developing a repair plan,and executing the repair work.The repair plan involved replacing the damaged component with a new one and conducting additional maintenance work to ensure optimal performance.The paper also discusses the outcomes of the repair work,which led to improved safety and increased efficiency of the overhead crane.The case study provides insights into the importance of regular maintenance and on-site inspections in ensuring the safe and efficient operation of mechanical systems.
文摘This paper provides empirical evidence that improved supplemental irrigation (ISI) can be justified on both environmental and economic grounds. Results of a stochastic frontier model which explicitly and simultaneously accounts for technical inefficiency and production risk applied to data collected from 513 wheat farms in the rainfed areas of Syria show that the typical adopter farmer obtained yield and productive efficiency gains of 6% and 7% respectively. A stochastic dominance criterion also showed that the adopter farmers got 10% and 13% reductions in risk of obtaining yield levels below 4 tons/ha and 3 tons/ha respectively. Given its adoption level of 22.3% in 2010, ISI led to the production of 52 thousand metric tons (6%), more wheat and conservation of 120 million cubic meters of water (10%). ISI has the potential to reduce total irrigation water use by upto 45% and for further increases in yield if accompanied with sprinklers and other improved agronomic practices, thereby enhancing food security and environmental sustainability in the country. An important policy implication of these findings is that wider dissemination of ISI along with other complementary agronomic practices in postwar Syria could be a viable option to be considered by national and international efforts for the restoration and rehabilitation of agriculture in the country.
文摘The prognostic role of cardiopulmonary exercise test (CPET) in elderly women with chronic heart failure (HF) has not yet been clarified. We assessed the incremental value of CPET variables for risk stratification in female HF patients with preserved or reduced left ventricular ejection fraction (LVEF). We prospectively followed up 131 female HF outpatients aged 72 [interquartile range 62 - 77] years after a symptom limited CPET. 34% had ischemic heart disease and 14% permanent atrial fibrillation, 24% were in NYHA class III. LVEF was 50% [interquartile range 36 - 62], peak oxygen consumption was 11.3 [interquartile range 9.2 - 13.5] ml/kg/min;the slope of the regression line relating ventilation to CO2 output was 33.9 [interquartile range 30.3 - 44.9];40% of patients showed exercise oscillatory breathing during CPET. During a median follow-up of 18 months [interquartile range 8 - 54], overall 39 patients (29.7%) met the combined end-point of cardiovascular mortality or HF admission using a time-to-first event approach. Moderate to severe mitral regurgitation, slope, exercise oscillatory breathing were independently associated to cardiovascular mortality or HF admission. When CPET ventilatory variables were added to clinical and echocardiographic parameters, prediction of the combined point improved significantly (AUC 0.755 (95% CI 0.662 to 0.832) vs 0.634 (95% CI 0.536 to 0.725), p = 0.016). In conclusion, among elderly female HF patients the CPET derived parameters EOB and VE/VCO2 slope emerged as strong prognostic markers, with additive predictive value to clinical and echocardiographic parameters in patients with both reduced and preserved LVEF.
文摘The paper refers to literatures to show how the state mitigates the effects of market failures in foreign trade.The research study leads to the conclusion that state interventions are necessary in creating administrative and legal conditions for facilitating trade exchange in the context of the role of transnational corporations in the global economy,as well as in reducing the adverse impact of international turbulences on the competitiveness of national entities through the use of export supporting instruments.
文摘This paper improves the slacks-based method for estimating inefficiency,derives the criteria for the selection of the weights of output and input inefficiencies in the objective function,and creates a new nonparametric method for accounting economic growth.Based on this method,the paper estimates the sources of China s economic growth from 1978 to 2013.Our findings suggest that factor input and especially capital is a major source of economic growth for China as a whole and its major regions,and that economic growth in recent years is increasingly dependent on capital.For a rather long period of time before 2005,China s northeast,central and western regions lagged behind the eastern region in terms of economic growth,and TFP and factor input are major reasons behind such regional growth disparities.Although other regions have narrowed their disparities with and even overtaken the eastern region in terms of economic growth,the key driver is the rapid increase in the contribution of factor input.Advanced technologies of eastern region should be utilized to promote TFP progress in other regions,which is vital to economic growth in these regions and China as a whole.
文摘The transformation of quantitative variables into categories is a common practice in both experimental and observational studies. The typical procedure is to create groups by splitting the original variable distribution at some cut point on the scale of measurement (e.g. mean, median, mode). Allegedly, dichotomization improves causal inference by simplifying statistical analyses. In this article, we address some of the adverse consequences of recoding quantitative variables into categories. In particular, we provide evidence that categorization usually leads to inefficient and biased estimates. We believe that considerable progress in our understanding of data analysis can occur if scholars follow the recommendations presented in this article. The recodification of quantitative variables as categorical is a poor methodological strategy, and scientists must stay away from it.
文摘This paper examines the problems existing in Extensive Reading Teaching for Vocational Business English Majors and analyses the contributing factors for the time-consuming and inefficient Extensive Reading Teaching.Based on the analysis,the author points out some solutions from the following several aspects:the teachers’ roles,the choice of textbooks and the organization of the class as well as the integrated design of the class activities,be carried out in the student-centered class to be practical and helpful in the Extensive Reading Teaching.
基金financial support provided by the China Natural Science Funding:[Grant Number71673134]sponsored by Qing Lan Project and the Fundamental Research Funds for the Central Universities:[Grant Number NJ20150035]
文摘Elasticity of substitution is traditionally estimated while ignoring technical and allocative inefficiencies,which could bias the estimates.We estimate elasticity of substitution for Chinese energy-intensive sectors by incorporating these inefficiencies.The results show most of the sectors are low substitutes between input factors and stress important differences among energy-intensive sectors.Concerning the cross-price elasticity for energy,with respect to capital(labor),the sectors are mainly characterized by weak substitutability or complementary.These imply the production structure is quite rigid and capital cannot be so readily used as a substitute for energy.
文摘Seafood plays an important role in human nutrition and its increased consumption is actively recommended for sustenance and health benefits in both developing and developed countries. In parallel to this, the public receives confusing advice as to what seafood is sustainably produced and is frequently misled about the environmental impacts of fishing, especially in locations such as Australia where contemporary fishery management has a conservation and sustainability focus. It is recognised globally that Australia’s traditional fishery management driven by strict sustainability and biodiversity regulations, has achieved impressive results in managing both fish stocks and the effects of fishing on marine environments. Despite this, continued pressure from non-government organisations (NGOs) and a perpetuation of the misuse of management terms such as “overfished” is used to promote the misguided need for ever increasing fishing restrictions, most obviously in “protected areas”. This paper questions the motives of some NGOs and governments in Australia in pursuing additional restrictions on fishing which are mostly unnecessary and disproportionate to the sustainability requirements of other sources of food. This is done within the context of the global need for sustainable seafood supply and the need for effective marine conservation that addresses all threats to marine ecosystems in proportion to the magnitude of each threat.
文摘Anchor points play an important role in data envelopment analysis theory and applications;they delineate the efficient part of the production possibility set(PPS)frontier.In this paper,we propose an approach for finding the anchor points of the PPS of the Banker,Charnes and Cooper(BCC)model.This approach is based on a variant of super-efficiency models and their duals.The necessary and sufficient conditions for the characterization of the anchor points are also provided.Finally,the applicability of the proposed model is illustrated with some numerical examples.
文摘The wide occurrence of new-emerging pollutants and their potential environmental and ecological risks have recently caused great public concerns. The paper firstly put forward the severe problem. Then the possible main reasons were analyzed which might attribute to both the inefficient removal of wastewater treatment plants with conventional technology and ignorance of the monitor and control of new-emerging pollutants in the effluents. Also, the complexity and extreme high costs may also make the organizations sidestep the problem. Finally, possible strategies to deal with the problems were proposed. The upgrade of wastewater treatment plants was important and urgent.
文摘With the rapid development of urbanization,the industrial parks originally located in the suburbs are gradually incorporated into the urban center.Industries that fail to follow the transformation of urban economic development and are forced to close,or enterprises that move out without conforming to the environment,become a gray area within the city.Most of the existing assessments are conducting single assessment of some indicators,but than their actual benefits.Through the field investigation on the starting area of Handan Economic Development Zone,and the evaluation on the nature of land use,development intensity,investment and output,and idle land,inefficient land use in the park is identified.According to different evaluation results,different update and promotion methods are put forward.The research could provide a new evaluation method and idea for subsequent renewal and development of urban industrial parks.