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
It was suggested by Pantanen that the mean squared error may be used to measure the inefficiency of the least squares estimator. Styan[2] and Rao[3] et al. discussed this inefficiency and it's bound later. In this...It was suggested by Pantanen that the mean squared error may be used to measure the inefficiency of the least squares estimator. Styan[2] and Rao[3] et al. discussed this inefficiency and it's bound later. In this paper we propose a new inefficiency of the least squares estimator with the measure of generalized variance and obtain its bound.展开更多
Demonstrating theoretically the possibility that the financial market, albeit incomplete, has equilibrium and that this equilibrium is efficient and has been an important topic at the frontier of the research on gener...Demonstrating theoretically the possibility that the financial market, albeit incomplete, has equilibrium and that this equilibrium is efficient and has been an important topic at the frontier of the research on general equilibrium for financial markets. The paper examines the asymptotic properties of incomplete financial markets taking into accounting the asset structure. The paper deals with a case in which a structure of securities relates to the asymptotic inefficiency.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
Compared with standard logit-based stochastic user equilibrium assignment model,the C-logit model describes route choice behavior in a more realistic way by considering the overlapping effect between routes.This paper...Compared with standard logit-based stochastic user equilibrium assignment model,the C-logit model describes route choice behavior in a more realistic way by considering the overlapping effect between routes.This paper investigates the inefficiency upper bounds of this model against the deterministic system optimum and the C-logit stochastic system optimum in terms of the total network travel time.It is found that the commonality factor of overlapping routes significantly affects the inefficiency bound,besides link congestion degree,total demand and the number of feasible routes.If the commonality factor is not considered,the efficiency loss resulting from selfishly stochastic travel behavior will be to large extent underestimated.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
This paper contributes to establish a new method to review (X) inefficiency of state owned enterprise. It set up an index system of (X) inefficiency to evaluate by Analytic Hierarchy Process (AHP). Based on this...This paper contributes to establish a new method to review (X) inefficiency of state owned enterprise. It set up an index system of (X) inefficiency to evaluate by Analytic Hierarchy Process (AHP). Based on this review result, this paper also put forward relative appraising of two times about (X) inefficiency of state owned enterprise by means of Data Envelopment Analysis (DEA). At last, a major conclusion is that this method is very helpful to review X inefficiency of state owned enterprise.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 deals with a type of servicing machines model, which service station has a life time of the kth Er-langian distribution and can be repaired just like a new one. The cyclic time and the inefficiency quantiti...This paper deals with a type of servicing machines model, which service station has a life time of the kth Er-langian distribution and can be repaired just like a new one. The cyclic time and the inefficiency quantities of this system in equilibrium are obtained.展开更多
This study provides estimates of smallholder household's production efficiency and its determinants, and separately analyses the technical efficiency of dairy technology adopting and non-adopting farmers using data f...This study provides estimates of smallholder household's production efficiency and its determinants, and separately analyses the technical efficiency of dairy technology adopting and non-adopting farmers using data from Ethiopia. Cobb-Douglas stochastic frontier production function was modeled in the context of local level agricultural innovation systems framework and estimated using 2011 milk production data on 304 dairy farmers. Results show that the mean level of technical efficiency among the sampled farmers was about 26%. This result suggests that there is room for significant increases of production through reallocation of existing resources. Despite significant variation among farmers, these results also indicate only 19% of farmers have mean efficiency scores (_〉 50%), implying a need to focus on creating innovation capacity that pushes the production frontier outward in the dairy production system. It is also revealed that individual farm households' efficiency varied widely across dairy technology adoption status, gender and districts. The significant gamma (g) statistic, of 0.9985 in the analysis indicates that about 99.85% variation in the output of milk production would be attributed to technical inefficiency effects (those under farmer's control) while only 0.0015% would be due to random effects, i.e., beyond the farmers control and hence calling for a focus on efficiency enhancing investments. Education, farm size, extension visit and off-farm income opportunity were found to be efficiency enhancing. The study recommends that different components of an agricultural innovation system have to interact to improve the innovation capacity of different actors and thereby improve the estimated technical inefficiencies.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 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 has deduced a non-parameter analysis framework that can estimate the sources of economic growth based on provincial data as samples. Result of the estimate indicates that between 1978 and 2010, TFP, labor a...This paper has deduced a non-parameter analysis framework that can estimate the sources of economic growth based on provincial data as samples. Result of the estimate indicates that between 1978 and 2010, TFP, labor and capital contributed to China's economic growth by 10.9%, 3.7% and 85.4% respectively. If the impact of global financial crisis is not taken into account, these figures should be 20.70/0, 3.3% and 76.0%. Contribution of labor to economic growth is the smallest, below 8%for most of the years. Share of TFP contribution increased before the 1990s despite wild swings, exceeding 50% in 1992, followed by continuous decline until well below 10% after 2005. Share of capital contribution decreased before 1990s with wild swings and maintained an upward trend after 1992, approaching 90% after 2005.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
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.
文摘It was suggested by Pantanen that the mean squared error may be used to measure the inefficiency of the least squares estimator. Styan[2] and Rao[3] et al. discussed this inefficiency and it's bound later. In this paper we propose a new inefficiency of the least squares estimator with the measure of generalized variance and obtain its bound.
文摘Demonstrating theoretically the possibility that the financial market, albeit incomplete, has equilibrium and that this equilibrium is efficient and has been an important topic at the frontier of the research on general equilibrium for financial markets. The paper examines the asymptotic properties of incomplete financial markets taking into accounting the asset structure. The paper deals with a case in which a structure of securities relates to the asymptotic inefficiency.
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.
基金supported by the National Basic Research Program of China under Grant No.2012CB725401the National Natural Science Foundation of China under Grant Nos.71271001 and 71401083the Program for New Century Excellent Talents in University under Grant No.NCET-13-0025
文摘Compared with standard logit-based stochastic user equilibrium assignment model,the C-logit model describes route choice behavior in a more realistic way by considering the overlapping effect between routes.This paper investigates the inefficiency upper bounds of this model against the deterministic system optimum and the C-logit stochastic system optimum in terms of the total network travel time.It is found that the commonality factor of overlapping routes significantly affects the inefficiency bound,besides link congestion degree,total demand and the number of feasible routes.If the commonality factor is not considered,the efficiency loss resulting from selfishly stochastic travel behavior will be to large extent underestimated.
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The project is supported by National Natural Science Foundation of China(70131010) the National Philosophy Social Science Innovation Base of Technology, Policy and Managment.
文摘This paper contributes to establish a new method to review (X) inefficiency of state owned enterprise. It set up an index system of (X) inefficiency to evaluate by Analytic Hierarchy Process (AHP). Based on this review result, this paper also put forward relative appraising of two times about (X) inefficiency of state owned enterprise by means of Data Envelopment Analysis (DEA). At last, a major conclusion is that this method is very helpful to review X inefficiency of state owned enterprise.
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 deals with a type of servicing machines model, which service station has a life time of the kth Er-langian distribution and can be repaired just like a new one. The cyclic time and the inefficiency quantities of this system in equilibrium are obtained.
文摘This study provides estimates of smallholder household's production efficiency and its determinants, and separately analyses the technical efficiency of dairy technology adopting and non-adopting farmers using data from Ethiopia. Cobb-Douglas stochastic frontier production function was modeled in the context of local level agricultural innovation systems framework and estimated using 2011 milk production data on 304 dairy farmers. Results show that the mean level of technical efficiency among the sampled farmers was about 26%. This result suggests that there is room for significant increases of production through reallocation of existing resources. Despite significant variation among farmers, these results also indicate only 19% of farmers have mean efficiency scores (_〉 50%), implying a need to focus on creating innovation capacity that pushes the production frontier outward in the dairy production system. It is also revealed that individual farm households' efficiency varied widely across dairy technology adoption status, gender and districts. The significant gamma (g) statistic, of 0.9985 in the analysis indicates that about 99.85% variation in the output of milk production would be attributed to technical inefficiency effects (those under farmer's control) while only 0.0015% would be due to random effects, i.e., beyond the farmers control and hence calling for a focus on efficiency enhancing investments. Education, farm size, extension visit and off-farm income opportunity were found to be efficiency enhancing. The study recommends that different components of an agricultural innovation system have to interact to improve the innovation capacity of different actors and thereby improve the estimated technical inefficiencies.
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 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 has deduced a non-parameter analysis framework that can estimate the sources of economic growth based on provincial data as samples. Result of the estimate indicates that between 1978 and 2010, TFP, labor and capital contributed to China's economic growth by 10.9%, 3.7% and 85.4% respectively. If the impact of global financial crisis is not taken into account, these figures should be 20.70/0, 3.3% and 76.0%. Contribution of labor to economic growth is the smallest, below 8%for most of the years. Share of TFP contribution increased before the 1990s despite wild swings, exceeding 50% in 1992, followed by continuous decline until well below 10% after 2005. Share of capital contribution decreased before 1990s with wild swings and maintained an upward trend after 1992, approaching 90% after 2005.
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.