THE ROLE OF FARM OWNERSHIP IN OFF-FARM WORK PARTICIPATION

A labor supply model is used to examine the relationship between farm ownership and operators' participation in the off-farm labor market for the Northeast region. The results indicate that ownership significantly influences operators' off-farm employment participation. In particular, part-owners significantly allocate labor services to off-farm activities. The results also show that the participation rate among part-owner operators is high partly because the availability of other income sources accelerates the process of acquiring assets to become full-owner operators.Labor and Human Capital,

SEARCH THEORY RISK PREFERENCE AND FARMLAND PRESERVATION

This paper uses search theory to examine the role that risk preference (RP) plays in farmland preservation. Assuming that the distribution of the offer price is fixed, the analysis indicates that risk-averse agents have lower reservation prices than risk-neutral agents, and that agricultural land held by the former exits farming at a faster rate. The results also show that farmland preservation policies which increase reservation prices have a greater capitalization effect if agents are risk-loving, and that such policies, while effectively protecting the interest of land speculators, may be less effective in serving the needs of farming and farm-held open space.Risk and Uncertainty,

Changes in soil labile and recalcitrant carbon pools after land-use change in a semi-arid agro-pastoral ecotone in Central Asia

Soil organic matter is a heterogeneous and complex entity that consists of a diverse range of compounds. However, the responses of soil organic carbon (SOC) fractions with different biochemical stabilities to land-use change are inadequately addressed. In this study, soil samples (0-60 cm) were collected with a 10 cm interval from grassland (GS), cropland (CS), woodland (WS), and orchard (OS) using paired-site approach in a typical semi-arid agro-pastoral ecotone in the Ili River Valley, Central Asia, to: (1) clarify the vertical changes in soil labile (LPI and LPII) and recalcitrant C pools (RP) after GS conversion to CS and CS conversion to WS and OS; and to (2) evaluate the impact of land-use change on SOC stability. The results indicated that LPI stocks in topsoil (0-30 cm) and subsoil (30-60 cm) showed opposite responses to land-use change. In contrast, LPII and RP stocks in both soil layers significantly decreased after conversion of GS to CS, and significantly increased after CS afforestation. These results demonstrated that RP in subsoils could also be altered by land-use change. In general, conversion from GS to CS decreased the recalcitrance index of SOC (RISOC), which increased after conversion from CS to WS. The results implied that cultivation decreased the stability of SOC, causing the depletion of SOC stock, whereas CS conversion to WS enhanced the stability of SOC, promoting SOC sequestration. The negative correlations between RISOC, pH, and electrical conductivity (EC1:5) suggested that soil pH and salinity were potential indicators reflecting the biochemical recalcitrance of SOC. Since both soil pH and EC1:5 showed decreasing trends after conversion from CS to WS and OS, the results suggested that afforestation on CS contributed to mitigate soil salinization while promoting SOC sequestration in this semi-arid agro-pastoral ecotone

EFFECTIVENESS OF USE-VALUE ASSESSMENT IN PRESERVING FARMLAND: A SEARCH-THEORETIC APPROACH

Search theory is used to present a theoretically defensible model to examine the effectiveness of use value assessment (UVA) in preserving farmland. The model is empirically tractable and supports the findings of past research. The analysis considers the impact of farm income, uncertainty, and the distribution of the offer price on the effectiveness of UVA in preserving farmland and shows, through the effect on the reservation price, that for a given distribution of the offer price, property-tax rate, and the difference between market-value and use-value of land, the preservation of agricultural land only takes place within a relevant range

EFFECTIVENESS OF USE-VALUE ASSESSMENT IN PRESERVING FARMLAND: A SEARCH-THEORETIC APPROACH

Search theory is used to present a theoretically defensible model to examine the effectiveness of use value assessment (UVA) in preserving farmland. The model is empirically tractable and supports the findings of past research. The analysis considers the impact of farm income, uncertainty, and the distribution of the offer price on the effectiveness of UVA in preserving farmland and shows, through the effect on the reservation price, that for a given distribution of the offer price, property-tax rate, and the difference between market-value and use-value of land, the preservation of agricultural land only takes place within a relevant range.Farmland preservation, Offer price, Reservation price, Search theory, Uncertainty, Use-value assessment, Land Economics/Use,

A Determination Method for Gait Event Based on Acceleration Sensors

A gait event is a crucial step towards the effective assessment and rehabilitation of motor dysfunctions. However, for the data acquisition of a three-dimensional motion capture (3D Mo-Cap) system, the high cost of setups, such as the high standard laboratory environment, limits widespread clinical application. Inertial sensors are increasingly being used to recognize and classify physical activities in a variety of applications. Inertial sensors are now sufficiently small in size and light in weight to be part of a body sensor network for the collection of human gait data. The acceleration signal has found important applications in human gait recognition. In this paper, using the experimental data from the heel and toe, first the wavelet method was used to remove noise from the acceleration signal, then, based on the threshold of comprehensive change rate of the acceleration signal, the signal was primarily segmented. Subsequently, the vertical acceleration signals, from heel and toe, were integrated twice, to compute their respective vertical displacement. Four gait events were determined in the segmented signal, based on the characteristics of the vertical displacement of heel and toe. The results indicated that the gait events were consistent with the synchronous record of the motion capture system. The method has achieved gait event subdivision, while it has also ensured the accuracy of the defined gait events. The work acts as a valuable reference, to further study gait recognition

Impact of Winter Snowfall on Vegetation Greenness in Central Asia

Snowfall is an important climatic variable with remarkable impacts on vegetation greenness in the alpine and extra-tropical regions. Central Asia (CA) is located in the middle latitude with high mountains, and the ecosystem is vulnerable to climate change in CA. In this region, the vegetation response to winter snowfall and its interactions with growing season climatic factors on vegetation greenness is still unclear. Thus, this study attempted to examine the impact of winter snowfall on vegetation greenness with remote-sensing vegetation index and reanalysis climatic data, and to investigate the interactions between winter snowfall and growing season climatic factors and their influence on vegetation growth via path analysis. The results showed that there is a generally positive correlation between winter snowfall and vegetation greenness from May to September and during the whole growing season (April to September). This positive correlation was significant in 8% of the study area for the whole growing season. However, the increase in winter snowfall was not beneficial to the regional vegetation growth in April. The vegetation response to winter snowfall also relates to land-cover type and elevation. The vegetation greenness in grassland was depicted to be more sensitive to winter snowfall than that in forestland. The response turned from positive to negative when the elevation increased from below 3000 m to above 3000 m. Moreover, the impact of winter snowfall on vegetation greenness was not regulated by temperature and precipitation in the growing season in more than 70% of CA. The impact relates to the interaction with April temperature in Central Kazakhstan, and is regulated by growing season precipitation in North Kazakhstan where annual precipitation mainly occurs in the growing season. The impact of winter snowfall on vegetation greenness is more important than growing season precipitation and temperature in some areas, since annual precipitation does not concentrate in the growing season or the relative increase of winter snowfall is great in these places. The results of the present study improve the understanding of vegetation response to climate change, and provide a scientific reference for environmental protection in CA and similar regions

Thrust Ripple Force Minimization and Efficiency Analysis of Electromagnetic Actuator on Active Suspension

A novel electromagnetic actuator for active suspension is designed on an in-wheel motor electric vehicle in this paper. Aiming at reducing thrust ripple force and improving stability of the actuator, a method of calculating the optimum slot width and optimizing edge radian of end tooth is proposed. Firstly, a finite element model (FEM) of the actuator is modeled, and the correctness of FEM is verified through comparisons of simulation results and analytical ones, including counterelectromotive force of coil winding and force characteristic test of the actuator. Based on the FEM, the influence of slot width on electromagnetic thrust and total harmonic distortion (THD) is analyzed, and the slot width is improved. The side effect of the actuator is considered. By improving the edge radian, the fluctuation of the cogging force and thrust ripple is reduced. In addition, output efficiency and energy feed efficiency of the actuator after reducing thrust ripple are studied. The results show the minimum THD is 4.2%, which is obtained at the slot width 4.3 mm, and thrust ripple is 36.5 N. When the edge radian is 60°, the thrust ripple decreases to only 15.7 N, which is reduced by 57.0%. The maximum output efficiency and energy feedback efficiency of the actuator are 87.5% and 27.1%, respectively. Finally, according to actuator characteristic tests of two working modes, it is concluded that the maximum energy feedback efficiency is 25.6%. The input current and current frequency should be gradually increased with the increase of suspension speed under active mode, and the maximum output efficiency is 80.2%. The test results are basically consistent with the FEM analysis values, which verify the correctness of the FEM analysis

Prediction of Epilepsy Based on Tensor Decomposition and Functional Brain Network

Epilepsy is a chronic neurological disorder which can affect 65 million patients worldwide. Recently, network based analyses have been of great help in the investigation of seizures. Now graph theory is commonly applied to analyze functional brain networks, but functional brain networks are dynamic. Methods based on graph theory find it difficult to reflect the dynamic changes of functional brain network. In this paper, an approach to extracting features from brain functional networks is presented. Dynamic functional brain networks can be obtained by stacking multiple functional brain networks on the time axis. Then, a tensor decomposition method is used to extract features, and an ELM classifier is introduced to complete epilepsy prediction. In the prediction of epilepsy, the accuracy and F1 score of the feature extracted by tensor decomposition are higher than the degree and clustering coefficient. The features extracted from the dynamic functional brain network by tensor decomposition show better and more comprehensive performance than degree and clustering coefficient in epilepsy prediction

SEARCH THEORY RISK PREFERENCE AND FARMLAND PRESERVATION

This paper uses search theory to examine the role that risk preference (RP) plays in farmland preservation. Assuming that the distribution of the offer price is fixed, the analysis indicates that risk-averse agents have lower reservation prices than risk-neutral agents, and that agricultural land held by the former exits farming at a faster rate. The results also show that farmland preservation policies which increase reservation prices have a greater capitalization effect if agents are risk-loving, and that such policies, while effectively protecting the interest of land speculators, may be less effective in serving the needs of farming and farm-held open space