Amphibious vehicles are more prone to attitude instability compared to ships,making it crucial to develop effective methods for monitoring instability risks.However,large inclination events,which can lead to instabili...Amphibious vehicles are more prone to attitude instability compared to ships,making it crucial to develop effective methods for monitoring instability risks.However,large inclination events,which can lead to instability,occur frequently in both experimental and operational data.This infrequency causes events to be overlooked by existing prediction models,which lack the precision to accurately predict inclination attitudes in amphibious vehicles.To address this gap in predicting attitudes near extreme inclination points,this study introduces a novel loss function,termed generalized extreme value loss.Subsequently,a deep learning model for improved waterborne attitude prediction,termed iInformer,was developed using a Transformer-based approach.During the embedding phase,a text prototype is created based on the vehicle’s operation log data is constructed to help the model better understand the vehicle’s operating environment.Data segmentation techniques are used to highlight local data variation features.Furthermore,to mitigate issues related to poor convergence and slow training speeds caused by the extreme value loss function,a teacher forcing mechanism is integrated into the model,enhancing its convergence capabilities.Experimental results validate the effectiveness of the proposed method,demonstrating its ability to handle data imbalance challenges.Specifically,the model achieves over a 60%improvement in root mean square error under extreme value conditions,with significant improvements observed across additional metrics.展开更多
Taking Niyang River Basin as an example, applying with the indices of landscape pattern, the indices of ecological risk of ecosystems are calculated in this paper, which takes the value of ecological loss of main ecos...Taking Niyang River Basin as an example, applying with the indices of landscape pattern, the indices of ecological risk of ecosystems are calculated in this paper, which takes the value of ecological loss of main ecosystem as the evaluation standard and takes into account the impacts of probability or the velocity of main hazards and event of the ecosystem. And the grades of ecological risk are assessed. According to the results of assessment, the ecological risk grades of the basin are divided into five classes. From the first grade risk to the fifth grade risk, the values of regional risk indices gradually reduce. The first grade risk areas mainly distribute in Niyang river and its branches downstream and the surrounding areas of main towns. And the basin area of non-valley region and the headstream regions of the branches are the fifth grades risk areas. This evaluation results provide the basis to the regional sustainable development.展开更多
According to optimal contracting theory, compensation contracts are effective in solving the agency problem between stockholders and managers. Executive compensation is naturally related to firm performance. However, ...According to optimal contracting theory, compensation contracts are effective in solving the agency problem between stockholders and managers. Executive compensation is naturally related to firm performance. However, contracts are not always perfect. Managers may exert influence on the formulation and implementation of compensation contracts by means of their managerial power. As fair value has been introduced into the new accounting standards in China, new concerns have arisen over the relationship between profits and losses from changes in fair value(CFV) and levels of executive compensation.In this study, we find that executive compensation is significantly related to CFV. However, this sensitivity is asymmetric in that increases to compensation due to profits from changes in fair value(PCFV) are higher than reductions to compensation due to losses from changes in fair value(LCFV). Furthermore,we find that managerial power determines the strength of this asymmetry.展开更多
Four environmemtal service functions of wheat, barley and rape ecosystem are evaluated in material production, air adjustment (including carbon dioxide fixation and oxygen release in Tibetan Autonomous Region), water ...Four environmemtal service functions of wheat, barley and rape ecosystem are evaluated in material production, air adjustment (including carbon dioxide fixation and oxygen release in Tibetan Autonomous Region), water conservation, and nutrient recycling. Based on it the economic loss of environment due to desertification is valued. The results show that the service functions of farmland ecosystem in Tibet are totally valued at 4 436. 2 × 106 yuan, the value of each service function is ordered as: air adjustment 2 070.2× 106 yuan (46.67%), material production 2 011. 1× 106 yuan (45.33%), nutrient recycling 193. 1×106 yuan (4.35%), and water conservation 161. 8×106 yuan (3.65%). The total area of wheat, barley and rape in Tibet is over 189 700 ha, and the service function of farmland ecosystem is valued at 23 386 yuan/ha per year. The degraded area of arable land in Tibet is about 1 082 ha per year, equivalent to the annual loss of farmland ecosystem service value of 25.3×106 yuan. Over the past 30 years the total loss of the value is 1 347.0×106 yuan.展开更多
基金Supported by the National Defense Basic Scientific Research Program of China.
文摘Amphibious vehicles are more prone to attitude instability compared to ships,making it crucial to develop effective methods for monitoring instability risks.However,large inclination events,which can lead to instability,occur frequently in both experimental and operational data.This infrequency causes events to be overlooked by existing prediction models,which lack the precision to accurately predict inclination attitudes in amphibious vehicles.To address this gap in predicting attitudes near extreme inclination points,this study introduces a novel loss function,termed generalized extreme value loss.Subsequently,a deep learning model for improved waterborne attitude prediction,termed iInformer,was developed using a Transformer-based approach.During the embedding phase,a text prototype is created based on the vehicle’s operation log data is constructed to help the model better understand the vehicle’s operating environment.Data segmentation techniques are used to highlight local data variation features.Furthermore,to mitigate issues related to poor convergence and slow training speeds caused by the extreme value loss function,a teacher forcing mechanism is integrated into the model,enhancing its convergence capabilities.Experimental results validate the effectiveness of the proposed method,demonstrating its ability to handle data imbalance challenges.Specifically,the model achieves over a 60%improvement in root mean square error under extreme value conditions,with significant improvements observed across additional metrics.
文摘Taking Niyang River Basin as an example, applying with the indices of landscape pattern, the indices of ecological risk of ecosystems are calculated in this paper, which takes the value of ecological loss of main ecosystem as the evaluation standard and takes into account the impacts of probability or the velocity of main hazards and event of the ecosystem. And the grades of ecological risk are assessed. According to the results of assessment, the ecological risk grades of the basin are divided into five classes. From the first grade risk to the fifth grade risk, the values of regional risk indices gradually reduce. The first grade risk areas mainly distribute in Niyang river and its branches downstream and the surrounding areas of main towns. And the basin area of non-valley region and the headstream regions of the branches are the fifth grades risk areas. This evaluation results provide the basis to the regional sustainable development.
基金supported by the Leading Academic Discipline Project from the Education Committee of Shanghai (Project No.J51701)the National Natural Science Foundation of China (Project No.70902063)+2 种基金the Humanities and Social Sciences Foundation of Ministry of Education of China (Project Nos.09YJC630157 and 12YJA790197)the Key Research and Innovation Project of Shanghai Municipal Education Commission (11ZS86)the IAPHD Project of Nanjing University
文摘According to optimal contracting theory, compensation contracts are effective in solving the agency problem between stockholders and managers. Executive compensation is naturally related to firm performance. However, contracts are not always perfect. Managers may exert influence on the formulation and implementation of compensation contracts by means of their managerial power. As fair value has been introduced into the new accounting standards in China, new concerns have arisen over the relationship between profits and losses from changes in fair value(CFV) and levels of executive compensation.In this study, we find that executive compensation is significantly related to CFV. However, this sensitivity is asymmetric in that increases to compensation due to profits from changes in fair value(PCFV) are higher than reductions to compensation due to losses from changes in fair value(LCFV). Furthermore,we find that managerial power determines the strength of this asymmetry.
基金part of the achievements of the special social welfare program "Research on value accounting system of degraded environment and important technical standards (2003DIA7J047)"
文摘Four environmemtal service functions of wheat, barley and rape ecosystem are evaluated in material production, air adjustment (including carbon dioxide fixation and oxygen release in Tibetan Autonomous Region), water conservation, and nutrient recycling. Based on it the economic loss of environment due to desertification is valued. The results show that the service functions of farmland ecosystem in Tibet are totally valued at 4 436. 2 × 106 yuan, the value of each service function is ordered as: air adjustment 2 070.2× 106 yuan (46.67%), material production 2 011. 1× 106 yuan (45.33%), nutrient recycling 193. 1×106 yuan (4.35%), and water conservation 161. 8×106 yuan (3.65%). The total area of wheat, barley and rape in Tibet is over 189 700 ha, and the service function of farmland ecosystem is valued at 23 386 yuan/ha per year. The degraded area of arable land in Tibet is about 1 082 ha per year, equivalent to the annual loss of farmland ecosystem service value of 25.3×106 yuan. Over the past 30 years the total loss of the value is 1 347.0×106 yuan.
