Evaluating the effectivenes s of forest restoration projects is crucial for designing adaptive restoration strategies.However,existing studies have primarily focused on ecological outcomes while overlooking cost input...Evaluating the effectivenes s of forest restoration projects is crucial for designing adaptive restoration strategies.However,existing studies have primarily focused on ecological outcomes while overlooking cost inputs.This gap can lead to increased uncertainties in restoration planning.Here we investigated forest dynamics in China's Upper Yangtze River Basin(UYRB)using kernel Normalized Difference Vegetation Index(kNDVI),Leaf Area Index(LAI),Gross Primary Productivity(GPP),Ku-band Vegetation Optical Depth(Ku-VOD)time series and climate data from1982 to 2020.Subsequently,we employed a residual trend analysis integrating temporal effects to determine the relative contributions of climate change and human activities to forest dynamics before and after the implementation of forest restoration engineering in 1998.Additionally,we developed an Afforestation Efficiency Index(AEI)to quantitatively assess the cost efficiency of afforestation projects.Results indicated that forest in the UYRB showed sustained increases during 1982-2020,with most areas experiencing greater growth after 1998 than before.Temporal effects of climatic factors influenced over 42.7%of the forest,and incorporating time-lag and cumulative effects enhanced climate-based explanations of forest variations by 1.61-24.73%.Human activities emerged as the dominant driver of forest dynamics post 1998,whereas climate variables predominated before this period.The cost-effectiveness of forest restoration projects in the UYRB typically ranges from moderate to high,with higher success predominantly observed in the northeastern and eastern counties,while the central,western,and northwestern counties mainly showed relatively low efficiency.These findings stress the need for assessing forest restoration outcomes from both ecological and cost perspectives,and can offer valuable insights for optimizing the layout of forest restoration initiatives in the UYRB.展开更多
The structure of the extended gate ion sensitive field effect transistor (EGISFET) is similar to the structure of the ion sensitive field effect transistor (ISFET).Moreover,the non-ideal effect of EGISFET is the mai...The structure of the extended gate ion sensitive field effect transistor (EGISFET) is similar to the structure of the ion sensitive field effect transistor (ISFET).Moreover,the non-ideal effect of EGISFET is the main impediment to development of commercial processes for sensitive devices.It is necessary to promote the stability and reliability of the devices by employing calibration circuits and the better fabrication conditions.The temporal drift exists in the entire measurement experiment. Furthermore,in this study we can reduce the temporal drift effect which influences the stability of the TiN sensitive electrode with the differential front-end offset circuit.The measurement system combines with shifting circuit,differential and instrument amplifiers.We employ the calibration circuit to compare with the variations of the output voltage,and expectably improve the stability and reliability of the TiN sensitive electrode by the novel calibration circuit.展开更多
On the basis of considering electrochemical reactions and collision relations in detail, a direct numerical simulation model of a helicon plasma discharge with three-dimensional two-fluid equations was employed to stu...On the basis of considering electrochemical reactions and collision relations in detail, a direct numerical simulation model of a helicon plasma discharge with three-dimensional two-fluid equations was employed to study the characteristics of the temporal evolution of particle density and electron temperature. With the assumption of weak ionization, the Maxwell equations coupled with the plasma parameters were directly solved in the whole computational domain. All of the partial differential equations were solved by the finite element solver in COMSOL Multiphysics^（TM） with a fully coupled method. In this work, the numerical cases were calculated with an Ar working medium and a Shoji-type antenna. The numerical results indicate that there exist two distinct modes of temporal evolution of the electron and ground atom density, which can be explained by the ion pumping effect. The evolution of the electron temperature is controlled by two schemes： electromagnetic wave heating and particle collision cooling. The high RF power results in a high peak electron temperature while the high gas pressure leads to a low steady temperature. In addition, an OES experiment using nine Ar I lines was conducted using a modified CR model to verify the validity of the results by simulation, showing that the trends of temporal evolution of electron density and temperature are well consistent with the numerically simulated ones.展开更多
Space-division multiplexing(SDM)offers a promising route to scaling data throughput in fiber-optic networks,but it also introduces challenges such as mode-dependent loss(MDL)and intermodal crosstalk,which increase the...Space-division multiplexing(SDM)offers a promising route to scaling data throughput in fiber-optic networks,but it also introduces challenges such as mode-dependent loss(MDL)and intermodal crosstalk,which increase the computational load on digital signal processing(DSP).Periodic mode mixing has been shown to mitigate these effects by redistributing loss and gain across modes and shortening the effective temporal impulse response over which crosstalk accumulates.In this work,we present a novel and compact mode-scrambling device,3D printed directly onto the facet of a few-mode fiber.展开更多
Comparison effects have been studied extensively in many fields.In particular,existing operations management articles have discussed the impact of comparison effects on enterprises'production and pricing decisions...Comparison effects have been studied extensively in many fields.In particular,existing operations management articles have discussed the impact of comparison effects on enterprises'production and pricing decisions.Research has also shown that consumers'purchasing decisions are primarily determined by three factors:product quality,selling price,and comparison effects.The current study introduces the concepts of social and temporal comparison effects to examine how comparison effects influence a monopolist's production quality and pricing strategy for substitutable products.Results reveal the following:(1)Setting different prices for even two types of substitutable products with negligible quality differences can divide customers into three groups under the influence of social comparison effects in a single-stage model.(2)The monopolist should avoid using a price discrimination strategy in which products with a short market life cycle have the same quality but different prices.(3)When the market life cycle of products is sufficiently long in the single-product market and the market with two substitutable products,the monopolist's optimal choice in the second stage is to keep production quality constant and increase the selling price.Consequently,the number of buyers does not decrease because of temporal comparison effects.Therefore,the firm increases its revenue.(4)For the market with two substitutable products with quality differences,one approximate optimal strategy for the enterprise in the second stage is to keep the selling price constant with the assumption that product quality cannot be adjusted after the first period.At this point,the consumption situation in the market is the same as that in the first stage.Therefore,when no external constraints exist,the monopolist firm can obtain more benefits in the second stage than in the first stage by exploiting the temporal comparison effects of consumers in the second stage.(5)When consumer identity information can be confirmed in the market,social comparison effects,similar to temporal comparison effects,could help the enterprise increase its price and profit while maintaining product quality.These social and temporal comparison effects constrain consumers.Thus,the number of people who continueto buyproducts does not decrease.展开更多
Due to the similarity of conditioning factors,the aggregation feature of landslides and the multi-temporal landslide inventory,the spatial and temporal effects of landslides need to be considered in landslide suscepti...Due to the similarity of conditioning factors,the aggregation feature of landslides and the multi-temporal landslide inventory,the spatial and temporal effects of landslides need to be considered in landslide susceptibility prediction(LSP).The ignorance of this issue will result in some biases and time-invariance in landslide susceptibility.Hence,a novel framework has been proposed to update landslide susceptibility by simultaneously considering the spatial and temporal effects of landslides at the regional scale.In this framework,the landslide inventory of Chongyi County has been divided into pre-and fresh-landslide inventories.According to the LSP results predicted by the support vector machine(SVM)model using the slope unit-based conditioning factors and pre-landslide inventory,a normalized spatial distance index(NSDI)is calculated to quantitatively represent the spatial correlation between landslides and surrounding slope units to develop the SVM-NSDI model.Furthermore,the SVM-Updating model,which incorporates the LSP results of the SVM-NSDI model and fresh-landslide inventory,could be developed to update the LSP results.Subsequently,the confusion matrix,the area under the receiver operating characteristic curve(AUC)and frequency ratio(FR)accuracy are used to evaluate the prediction performance of the above LSP models.The F1-score values of the SVM,SVM-NSDI and SVM-Updating models are 0.776,0.816 and 0.831,respectively.The AUC values are 0.869,0.903 and 0.914 and the FR accuracies are 0.795,0.853 and 0.873.It can be concluded that landslide susceptibility is a time-variant variable,which can be updated by considering the spatial correlation between landslides and surrounding slope units as well as the temporal effects of multi-temporal landslide inventory.This study provides a new framework to update landslide susceptibility over time and also provides more accurate LSP results for decisionmakers.展开更多
With the rapid development of location-based networks, point-of-interest（POI） recommendation has become an important means to help people discover interesting and attractive locations, especially when users travel o...With the rapid development of location-based networks, point-of-interest（POI） recommendation has become an important means to help people discover interesting and attractive locations, especially when users travel out of town. However, because users only check-in interaction is highly sparse, which creates a big challenge for POI recommendation. To tackle this challenge, we propose a joint probabilistic generative model called geographical temporal social content popularity（GTSCP） to imitate user check-in activities in a process of decision making, which effectively integrates the geographical influence, temporal effect, social correlation, content information and popularity impact factors to overcome the data sparsity, especially for out-of-town users. Our proposed the GTSCP supports two recommendation scenarios in a joint model, i.e., home-town recommendation and out-of-town recommendation. Experimental results show that GTSCP achieves significantly superior recommendation quality compared to other state-of-the-art POI recommendation techniques.展开更多
基金supported by the National Natural Science Foundation of China(42071238)the Jiuzhaigou Post-Disaster Restoration and Reconstruction Program(5132202020000046)+1 种基金the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)the Ministry of Science and Technology of the People's Republic of China(2019QZKK0402)。
文摘Evaluating the effectivenes s of forest restoration projects is crucial for designing adaptive restoration strategies.However,existing studies have primarily focused on ecological outcomes while overlooking cost inputs.This gap can lead to increased uncertainties in restoration planning.Here we investigated forest dynamics in China's Upper Yangtze River Basin(UYRB)using kernel Normalized Difference Vegetation Index(kNDVI),Leaf Area Index(LAI),Gross Primary Productivity(GPP),Ku-band Vegetation Optical Depth(Ku-VOD)time series and climate data from1982 to 2020.Subsequently,we employed a residual trend analysis integrating temporal effects to determine the relative contributions of climate change and human activities to forest dynamics before and after the implementation of forest restoration engineering in 1998.Additionally,we developed an Afforestation Efficiency Index(AEI)to quantitatively assess the cost efficiency of afforestation projects.Results indicated that forest in the UYRB showed sustained increases during 1982-2020,with most areas experiencing greater growth after 1998 than before.Temporal effects of climatic factors influenced over 42.7%of the forest,and incorporating time-lag and cumulative effects enhanced climate-based explanations of forest variations by 1.61-24.73%.Human activities emerged as the dominant driver of forest dynamics post 1998,whereas climate variables predominated before this period.The cost-effectiveness of forest restoration projects in the UYRB typically ranges from moderate to high,with higher success predominantly observed in the northeastern and eastern counties,while the central,western,and northwestern counties mainly showed relatively low efficiency.These findings stress the need for assessing forest restoration outcomes from both ecological and cost perspectives,and can offer valuable insights for optimizing the layout of forest restoration initiatives in the UYRB.
文摘The structure of the extended gate ion sensitive field effect transistor (EGISFET) is similar to the structure of the ion sensitive field effect transistor (ISFET).Moreover,the non-ideal effect of EGISFET is the main impediment to development of commercial processes for sensitive devices.It is necessary to promote the stability and reliability of the devices by employing calibration circuits and the better fabrication conditions.The temporal drift exists in the entire measurement experiment. Furthermore,in this study we can reduce the temporal drift effect which influences the stability of the TiN sensitive electrode with the differential front-end offset circuit.The measurement system combines with shifting circuit,differential and instrument amplifiers.We employ the calibration circuit to compare with the variations of the output voltage,and expectably improve the stability and reliability of the TiN sensitive electrode by the novel calibration circuit.
基金funding from National Natural Science Foundation of China under grant agreement No. 11305265 (research on the acceleration mechanism of an electric double layer in a helicon plasma with a divergent magnetic field)
文摘On the basis of considering electrochemical reactions and collision relations in detail, a direct numerical simulation model of a helicon plasma discharge with three-dimensional two-fluid equations was employed to study the characteristics of the temporal evolution of particle density and electron temperature. With the assumption of weak ionization, the Maxwell equations coupled with the plasma parameters were directly solved in the whole computational domain. All of the partial differential equations were solved by the finite element solver in COMSOL Multiphysics^（TM） with a fully coupled method. In this work, the numerical cases were calculated with an Ar working medium and a Shoji-type antenna. The numerical results indicate that there exist two distinct modes of temporal evolution of the electron and ground atom density, which can be explained by the ion pumping effect. The evolution of the electron temperature is controlled by two schemes： electromagnetic wave heating and particle collision cooling. The high RF power results in a high peak electron temperature while the high gas pressure leads to a low steady temperature. In addition, an OES experiment using nine Ar I lines was conducted using a modified CR model to verify the validity of the results by simulation, showing that the trends of temporal evolution of electron density and temperature are well consistent with the numerically simulated ones.
基金Horizon 2020 Framework Programme(619732)Ministry of Innovation,Science and Technology,Fulbright U.S.Scholar Program。
文摘Space-division multiplexing(SDM)offers a promising route to scaling data throughput in fiber-optic networks,but it also introduces challenges such as mode-dependent loss(MDL)and intermodal crosstalk,which increase the computational load on digital signal processing(DSP).Periodic mode mixing has been shown to mitigate these effects by redistributing loss and gain across modes and shortening the effective temporal impulse response over which crosstalk accumulates.In this work,we present a novel and compact mode-scrambling device,3D printed directly onto the facet of a few-mode fiber.
文摘Comparison effects have been studied extensively in many fields.In particular,existing operations management articles have discussed the impact of comparison effects on enterprises'production and pricing decisions.Research has also shown that consumers'purchasing decisions are primarily determined by three factors:product quality,selling price,and comparison effects.The current study introduces the concepts of social and temporal comparison effects to examine how comparison effects influence a monopolist's production quality and pricing strategy for substitutable products.Results reveal the following:(1)Setting different prices for even two types of substitutable products with negligible quality differences can divide customers into three groups under the influence of social comparison effects in a single-stage model.(2)The monopolist should avoid using a price discrimination strategy in which products with a short market life cycle have the same quality but different prices.(3)When the market life cycle of products is sufficiently long in the single-product market and the market with two substitutable products,the monopolist's optimal choice in the second stage is to keep production quality constant and increase the selling price.Consequently,the number of buyers does not decrease because of temporal comparison effects.Therefore,the firm increases its revenue.(4)For the market with two substitutable products with quality differences,one approximate optimal strategy for the enterprise in the second stage is to keep the selling price constant with the assumption that product quality cannot be adjusted after the first period.At this point,the consumption situation in the market is the same as that in the first stage.Therefore,when no external constraints exist,the monopolist firm can obtain more benefits in the second stage than in the first stage by exploiting the temporal comparison effects of consumers in the second stage.(5)When consumer identity information can be confirmed in the market,social comparison effects,similar to temporal comparison effects,could help the enterprise increase its price and profit while maintaining product quality.These social and temporal comparison effects constrain consumers.Thus,the number of people who continueto buyproducts does not decrease.
基金funded by the National Natural Science Foundation of China(Nos.52222905,52179103,41807285,41972280 and 42272326)China Postdoctoral Science Foundation(No.2019M652287)Jiangxi Provincial Natural Science Foundation(Nos.20181ACB20008,20192BBG70078)。
文摘Due to the similarity of conditioning factors,the aggregation feature of landslides and the multi-temporal landslide inventory,the spatial and temporal effects of landslides need to be considered in landslide susceptibility prediction(LSP).The ignorance of this issue will result in some biases and time-invariance in landslide susceptibility.Hence,a novel framework has been proposed to update landslide susceptibility by simultaneously considering the spatial and temporal effects of landslides at the regional scale.In this framework,the landslide inventory of Chongyi County has been divided into pre-and fresh-landslide inventories.According to the LSP results predicted by the support vector machine(SVM)model using the slope unit-based conditioning factors and pre-landslide inventory,a normalized spatial distance index(NSDI)is calculated to quantitatively represent the spatial correlation between landslides and surrounding slope units to develop the SVM-NSDI model.Furthermore,the SVM-Updating model,which incorporates the LSP results of the SVM-NSDI model and fresh-landslide inventory,could be developed to update the LSP results.Subsequently,the confusion matrix,the area under the receiver operating characteristic curve(AUC)and frequency ratio(FR)accuracy are used to evaluate the prediction performance of the above LSP models.The F1-score values of the SVM,SVM-NSDI and SVM-Updating models are 0.776,0.816 and 0.831,respectively.The AUC values are 0.869,0.903 and 0.914 and the FR accuracies are 0.795,0.853 and 0.873.It can be concluded that landslide susceptibility is a time-variant variable,which can be updated by considering the spatial correlation between landslides and surrounding slope units as well as the temporal effects of multi-temporal landslide inventory.This study provides a new framework to update landslide susceptibility over time and also provides more accurate LSP results for decisionmakers.
基金supported by the National Key Project of Scientific and Technical Supporting Programs of China(2014BAK15B01)
文摘With the rapid development of location-based networks, point-of-interest（POI） recommendation has become an important means to help people discover interesting and attractive locations, especially when users travel out of town. However, because users only check-in interaction is highly sparse, which creates a big challenge for POI recommendation. To tackle this challenge, we propose a joint probabilistic generative model called geographical temporal social content popularity（GTSCP） to imitate user check-in activities in a process of decision making, which effectively integrates the geographical influence, temporal effect, social correlation, content information and popularity impact factors to overcome the data sparsity, especially for out-of-town users. Our proposed the GTSCP supports two recommendation scenarios in a joint model, i.e., home-town recommendation and out-of-town recommendation. Experimental results show that GTSCP achieves significantly superior recommendation quality compared to other state-of-the-art POI recommendation techniques.
