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Abstract: Loess shoulder-lines are the most critical terrain feature in representing and modeling the landforms of the Loess Plateau of China. Existing algorithms usually fail in obtaining a continuous shoulder-line for complicated surface, DEM quality and algorithm limitation. This paper proposes a new method, by which gradient vector flow (GVF) snake model is employed to generate an integrated contour which could connect the discontinuous fragments of shoulder-line. Moreover, a new criterion for the selection of initial seeds is created for the snake model, which takes the value of median smoothing of the local neighborhood regions. By doing this, we can extract the adjacent boundary of loess positive–negative terrains from the shoulder-line zones, which build a basis to found the real shoulder-lines by the gradient vector flow. However, the computational burden of this method remains heavy for large DEM dataset. In this study, a parallel computing scheme of the cluster for automatic shoulder-line extraction is proposed and implemented with a parallel GVF snake model. After analyzing the principle of the method, the paper develops an effective parallel algorithm integrating both single program multiple data (SPMD) and master/slave (M/S) programming modes. Based on domain decomposition of DEM data, each partition is decomposed regularly and calculated simultaneously. The experimental results on different DEM datasets indicate that parallel programming can achieve the main objective of distinctly reducing execution time without losing accuracy compared with the sequential model. The hybrid algorithm in this study achieves a mean shoulder-line offset of 15.8m, a quite satisfied result in both accuracy and efficiency compared with published extraction methods. [Copyright &y& Elsevier]

Abstract: AVS (audio video coding standard) is the latest multimedia coding standard of China. Similar to H.264/AVC, AVS adopted the technology of fractional-pel-accurate motion compensation, which enhanced the compression efficiency. To obtain fractional pels, 4-tap FIR filters and bilinear filters are used for luma and chroma interpolation respectively. Unlike the VLSI-optimized FIR filters which could be implemented by adders and shifters, the bilinear filter for chroma is not so convenient for direct VLSI implementation due to its multiplications. In this paper, we propose a VLSI-oriented algorithm named SHAM (x–y-separated halved-approaching method) to accomplish the bilinear filtering. The proposed SHAM algorithm adopts a halved-approaching method which is an addition-and-shift-only method and with simpler data path. VLSI structures are also provide to implement the SHAM algorithm in this paper. Experiments based on UMC process show that the SHAM algorithm could be implemented with about 48% less silicon area or at doubled frequency compared with the direct implementation of the bilinear filter. [Copyright &y& Elsevier]

In this paper, a semantic description method based on improved WM algorithm is proposed to characterize the facial features of larger Chinese ethnic groups. We firstly utilize the face landmarking technique to extract facial feature points automatically. Geometric features are defined with these detected landmarks, including distances, perimeters and areas. Then the WM method is improved to generate linguistic rule from facial geometric feature data, which implements semantic description for multi-ethnic facial characteristics. Finally, a case study of learning ethnicity from face with proposed method is investigated in CEFD database. The experiment results indicate that the linguistic rule base obtained by method is competitive in ethnicity recognition compared with method Naive Bayes, C4.5, Decision Table, Random Forest, Adaboost and Logistic regression in terms of accuracy and interpretability. [ABSTRACT FROM AUTHOR]

Abstract: A new construction adder based on Chinese abacus algorithm is presented in this paper. There are two kinds of beads used in this construction. Each column element has three higher beads with a weight of four and three lower beads with a weight of one. The proposed 32-bit adder contains eight column elements. The construction was simulated by the technology of TSMC 0.18μm CMOS process. Layout was also made by the same technology. The maximum delay of the 32-bit abacus adder is 0.91ns and 14% less than that of Carry Look-ahead Adders for 0.18μm technology. The power consumption of the abacus adder is 3.1mW and 28% less than that of Carry Look-ahead Adders for 0.18μm technology. Recent researches are compared with the proposed adder. The construction was also simulated by Predictive Technology Model. The PTM results also presented. The use of Chinese abacus approach offers a competitive technique with respect to other adders. [Copyright &y& Elsevier]

Abstract: Accurate estimation of the reference crop evapotranspiration (ET 0) is investigated due to its critical role in affecting calculation of crop water use and efficiency in agricultural ecosystems. The main emphasis in this paper is to clarify the possible uncertainty in the estimation of ET 0 associated with using un-calibrated Ångström–Prescott (A–P) coefficients. We first calibrated the coefficients using long-term data records from 34 sites in the Yellow River basin in China, and then applied these coefficients to estimate short wave irradiance (R s ) and ET 0 at 16 sites to evaluate the difference in ET 0 between the FAO recommended and the locally calibrated. We found that the direct use of the FAO recommended coefficients significantly affected the estimation of ET 0 at most sites, which differed from −3% to 15% at daily scale and from −4% to 16% at monthly scale from the locally calibrated ones. These differences are comparable with or larger than those caused by some alternatives of the FAO recommended algorithms for net irradiance or vapor pressure, which further highlights the importance of using the locally calibrated coefficients. The degree of difference in ET 0 showed a significant threshold relation with altitude and longitude in such a way that relatively small impact lies around 2233m and 98°E, and away from these, the effect begins to increase. Given the large overestimation in water use as a consequence of the significant overestimation in ET 0 associated with the direct use of the FAO coefficients, especially in those high yield production areas with altitude <1200m, we developed several relationships between the A–P coefficient a, b, (a + b) and other easily obtainable factors (altitude, longitude and air temperature). A three-step procedure was recommended in applying these relations, which was (1) determine if calibration is needed or not for a given location; (2) estimate one of the A–P coefficients, either a or b if calibration is needed; (3) estimate the remaining coefficient using relations of (a + b) due to its higher coefficient of determination. In summary, we have revealed the errors and areas that are most affected when using the un-calibrated coefficients, and discussed the consequence of such error on agricultural production, and proposed practical solutions to avoid large errors. These results are intended to make the research community aware of such errors so that more appropriate choice of these coefficients is made. We hope that similar assessment will be done in other climates, contributing to managing water resources efficiently in water basins. [Copyright &y& Elsevier]

Abstract: In this paper, we used the available algorithm for soil moisture estimation over LOPEX05 (the Loess Plateau land surface process Experiment (2005)) area. The available algorithm used ENVISAT/ASAR AP mode VV polarization observational data at a low incidence angle and ground measured soil moistures. The ground measurements were performed in the summer of the 2005 during the LOPEX05 field campaign. The validated results indicate that an average difference between the soil moistures estimated from the microwave remote sensing and ground measurements is less than 0.02cm3/cm3, with a RMS error of 2.0%, and a maximum less than 0.04cm3/cm3. The algorithm was applied to the surface soil moisture mapping later. The results show that this algorithm is suitable for monitoring soil moisture information of the agricultural fields over the Chinese Loess Plateau, when ground land cover situation and the resolution of imagery data are taken into account. However, we also find that there are large differences over the steep slope region, the edge of mesa. The results are not acceptable for surface soil moisture estimation in these regions. Thus, the surface soil moisture retrieval in the steep slope region of the Loess Plateau need to be further investigated in the future. [Copyright &y& Elsevier]