52 research outputs found
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A Special Event Loyalty Model: Comparing First Time and Repeat Attendees
Xiangping Li works as an assistant professor at Tourism College, Institute for Tourism Studies, Macao, China. Her research interests include tourism planning and development; destination marketing, and tourist behavior.Oral Presentatio
Influence of Grapheme and Syllable Learning on Handwriting Output of Chinese Characters in Children With Dictation Difficulties
Studies on Chinese dictation difficulties have focused on visual processing and phonological processing. In recent decades, attention has shifted to the ability to bind visual and auditory information. However, such studies are scarce and rarely focus on how this ability influences children’s learning and writing of Chinese characters. In this study, a group of children with Chinese dictation difficulties and a control group without such difficulties were instructed to learn rarely used Chinese characters under three learning modes: grapheme learning, syllable learning, and grapheme-syllable learning. Participants’ learning time and writing accuracy were recorded under each learning mode. Findings showed that under the grapheme learning mode, learning time and writing accuracy failed to differ significantly between the two groups. However, under the grapheme-syllable learning mode, the writing accuracy of children with dictation difficulties was significantly lower than controls. These findings, taken together, suggested that for children with dictation difficulties, learning graphemes and syllables at the same time did not improve their writing performance as much as the controls. Under the syllable learning mode, learning time and writing accuracy failed to differ significantly between the two groups. The findings contributed to a better understanding of the Chinese dictation difficulties
Regional temperature response to different forest development stages in Fennoscandia explored with a regional climate model
Several studies investigated the regional temperature effects of afforestation or deforestation, but the impacts of different forest development stages or alternative forest management received limited attention. This is mainly due to challenges in representing area-limited forest dynamics in low-resolution climate models and the need for accurate forest parameters. This study investigates the impact of alternative forest development stages and composition on regional climate in Fennoscandia using a coupled regional climate model. By incorporating realistic and high-resolution forest maps, our modelling framework reduces biases in estimating surface temperature compared to default model runs. If today's forest composition of tree species is left to achieve a mature state (a proxy for the absence of harvesting), an annual mean reduction in 2 m air temperature is estimated, with a cooling peak in summer of -0.53 ± 0.20 °C (mean ± standard deviation) mainly induced by increased cloud cover. Conversely, undeveloped forests (a proxy for increased harvest) induce a contrasting seasonal response: a summer warming of 0.53 ± 0.15 °C (mainly caused by higher sensible heat fluxes), and a weak winter cooling of -0.14 ± 0.24 °C (mainly caused by a higher surface albedo). A transition from evergreen to deciduous forests shows a summer average cooling of -0.57 ± 0.28 °C, mainly attributed to changes in surface albedo. These temperature effects are equivalent to a relatively large fraction of the expected warming by 2050 in Fennoscandia (from 16 % to 70 %, depending on the specific scenario and season). Some modelling outputs appear inconsistent with observations and past modelling studies, such as the cooling effects in winter of more developed forests. Our results provide new insights into the complex relationships between forest dynamics and regional temperature, but modelling improvements are still needed to achieve a robust understanding of the regional climate effects of forest management
Convex Relaxation Algorithms for Energy-Infeasibility Tradeoff in Cognitive Radio Networks
In cognitive radio networks, uncontrolled access of secondary users degrades the performance of primary users and can even lead to system infeasibility, as the secondary users are allowed to transmit simultaneously on a shared spectrum. We study the feasibility of the total energy consumption minimization problem subjecting to power budget and Signal-to-Interference-plus-Noise Ratio (SINR) constraints. Finding the largest set of secondary users (i.e., the system capacity) that can be supported in the system is hard to solve due to the nonconvexity of the cardinality objective. We formulate this problem as a vector-cardinality optimization problem, and propose a convex relaxation that replaces the objective with a continuous and convex function. Motivated by the sum-of-infeasibilities heuristic, a joint power and admission control algorithm is proposed to compute the maximum number of secondary users that can be supported. Numerical results are presented to show that our algorithm is theoretically sound and practically implementable
County-Scale Spatial Distribution of Soil Enzyme Activities and Enzyme Activity Indices in Agricultural Land: Implications for Soil Quality Assessment
Here the spatial distribution of soil enzymatic properties in agricultural land was evaluated on a county-wide (567 km2) scale in Changwu, Shaanxi Province, China. The spatial variations in activities of five hydrolytic enzymes were examined using geostatistical methods. The relationships between soil enzyme activities and other soil properties were evaluated using both an integrated total enzyme activity index (TEI) and the geometric mean of enzyme activities (GME). At the county scale, soil invertase, phosphatase, and catalase activities were moderately spatially correlated, whereas urease and dehydrogenase activities were weakly spatially correlated. Correlation analysis showed that both TEI and GME were better correlated with selected soil physicochemical properties than single enzyme activities. Multivariate regression analysis showed that soil OM content had the strongest positive effect while soil pH had a negative effect on the two enzyme activity indices. In addition, total phosphorous content had a positive effect on TEI and GME in orchard soils, whereas alkali-hydrolyzable nitrogen and available potassium contents, respectively, had negative and positive effects on these two enzyme indices in cropland soils. The results indicate that land use changes strongly affect soil enzyme activities in agricultural land, where TEI provides a sensitive biological indicator for soil quality
The Key Technology Design of the Real-Time Monitoring System Based on FPGA
Due to having a direct affect for the growth of crops, the monitor and modification for the indicators of Greenhouse environment play significant roles in improving the yield of crops. The system, which adopts FPGA technology to control and modify the air condition and lighting system by collecting and analyzing the data of the temperature and humidity, has achieved good effects in practice. In our study, the key technology of real-time data acquisition system based on FPGA is proposed. In particular, based on FPGA, the designed ADC0809 and asynchronous FIFO can save the data in real time, which can be analyzed and disposed timely, so that the environment can be corrected in time.</p
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