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In view of the uncertainty and intermittency of wind power, this paper proposes an optimal economical dispatch (ED) model and develops a method to estimate risk and manage hybrid power systems (traditional + wind~power~systems) for the short-term (24 h) operations. The model and the method have taken into account the large wind power penetration and the wind variability. The particle swarm optimization (PSO) refid="ref1"/ algorithm with constraints is applied to solve the ED problem. Value at risk (VaR) refid="ref2"/ and integrated risk management (IRM) refid="ref3"/ are used separately to assess the risk, so that an optimal tradeoff between the profit and risk is made for the system operations. The model and the method are tested on the standard IEEE 30-bus power system and network in Shanghai. The validity of the model and the method has been approved. [ABSTRACT FROM PUBLISHER]

Traditional remote sensing observation can only derive chlorophyll-a concentration in surface water (Chlasurf), which is insufficient for water quality monitoring or biogeochemical applications. In this paper, a column-integrated biomass (CIB) estimation algorithm was established in Lake Dianchi, China, and the CIB was estimated by Ocean and Land Color Instrument (OLCI) data from 2016 to 2018. First, the results show that the method is applicable to CIB estimation in nonbloom conditions [mean absolute percentage error (MAPE) = 10.55%, mean ratio (MR) = 0.996]. On the one hand, Chlasurf could be estimated using a universal model of Chla (UMOC) estimation for case-II waters; on the other hand, CIB could be obtained from Chlasurf according to the linear relationship between the Chlasurf and CIB. Second, both the spatial and temporal variabilities of Chlasurf are larger than those of CIB, which indicates that the biomass of the whole lake is relatively stable from day to day. During algal bloom periods, the CIB at nonbloom areas tends to decrease, suggesting that algae from nonbloom regions have migrated to bloom regions. Third, wind speed (WS) is the most critical meteorological factor affecting the water surface biomass, compared with other parameters. The average percentage of surface-to-total biomass in nonbloom conditions is about 7% when the WS is less than 2 m/s. [ABSTRACT FROM AUTHOR]

The three-dimentional plant canopy architecture is often characterized using the foliage clumping index useful for ecological and land surface modeling. In this paper, an algorithm is developed to retrieve the foliage clumping index with the Moderate Resolution Imaging Spectroradiometer bidirectional reflectance distribution function (BRDF) parameter product (MCD43A1), which is generated using the RossThick-LiSparse Reciprocal (Ross-Li) model. First, the Ross-Li model is modified to improve the simulation of the reflectance at hotspot using the Polarization and Directionality of Earth Reflectance measurements as benchmarks to determine BRDF parameters. Then, the modified model (Ross-Li-H) is used to simulate the reflectance at hotspot and darkspot, which is used to calculate the normalized difference between hotspot and darkspot (NDHD). With the relationship between clumping index and NDHD simulated by the 4-Scale geometrical model, the clumping index over China's landmass at 500-m resolution is retrieved every 8 days during the period from 2003 to 2008. Finally, The effect of topography on the retrieved clumping index is corrected using a topographic compensation function calculated from the digital elevation model at 90-m resolution. The topographically corrected clumping index values correlate well with field measurements at five sites over China, indicating the feasibility of the algorithm for retrieving the clumping index from the MCD43A1 product. [ABSTRACT FROM AUTHOR]

Analyzing mobile telephony diffusion involves identifying drivers and forecasting growth using a growth model. However, to our knowledge, no framework for model selection exists. To eliminate ad hoc model selection, this study presents a novel model-comparison method based on an analysis of mobile telephony diffusion in China, which accounts for one-fifth of global mobile telephony subscriptions. Determinants of the diffusion rate are then analyzed using the most appropriate model identified by the proposed model-comparison method in terms of minimum root-mean-square error. Empirical results identify the Gompertz model as the best model for diffusion forecasting. The three most significant determinants are low-cost mobile handsets, prepaid services, and personal handy-phone system (PHS) services. All of these determinants contribute to meeting the demand in China's low-end market. This study combines the proposed model-comparison method with estimates of determinants of diffusion rate to improve analysis and forecasting accuracy for mobile telephony diffusion. Moreover, model comparisons using data from eight representative countries (Brazil, China, France, Germany, India, Russia, the U.K., and the U.S.) provide a valuable reference for model selection for mobile telephony diffusion. [ABSTRACT FROM PUBLISHER]

Motivated by the rapid growth of and an increasing interest in the Chinese online auction market, we empirically investigated EachNet (www.eachnet.com), a highly popular eBay model of a Chinese consumer-to-consumer online auction site. Based on EachNet 's auction mechanisms, a general framework was developed to guide the evaluation of various seller- and buyer-specific factors affecting the outcomes of online auctions, as well as the interrelationships among these factors. Three product-independent performance indicators, namely success-or-failure, effectiveness, and satisfaction, were proposed for assessing the online auction outcome instead of basing assessment on the final price that may vary significantly among different product categories. Our empirical results suggest that the impact of seller characteristics and seller-determined auction attributes on auction performance are partially mediated by the volume of bids generated by all competing bidders during the auction. The implications of this study are also discussed to encourage further research in this area. [ABSTRACT FROM PUBLISHER]