This paper studies the supercritical Bernoulli bond percolation in two dimensions, focusing on properties of the winding angles of open paths. Under the condition that there exists an open path from the origin to the boundary of box B(n), we prove that a law of large numbers holds for the maximum of such paths' winding angles. Moreover, we show that for any δ>0, there is a high probability that the distance between two adjacent contact points in two neighboring "innermost" left-right crossings is less than log1+δn for sufficiently large n.
In this paper, we study minimal two-spheres in Q3 by harmonic sequence, and we obtain four classes of linearly full minimal two-spheres with constant curvature. Although they are also minimal in CP4, their geometric properties are different.
In this paper, we investigate the convergence rate of the limit of a controlled branching process with random control functions in the varying environment after suitable normalization.
In materials with no spatial inversion symmetry, the antisymmetric spin-orbit coupling can cause an admixture of the spin-singlet and spin-triplet pairings. We study the influence of the spin-orbit coupling and the degree of parity mixing on the specific heat and spin susceptibility of such superconductors, with a particular emphasis on the heavy fermion superconductor CePt3Si. Results compatible with experimental findings are obtained.
The photodissociation of 1,2-C2H4Br2 has been investigated by spin-orbit ab initio calculations. The vertical excitation energies for some excited states of 1,2-C2H4Br2 were calculated. The potential energy curves of 1,2-C2H4Br2 along the C—Br dissociation coordinate were calculated using the MS-CASPT2/CASSI-SO method. The photodissociation channels of 1,2-C2H4Br2 leading to C2H4Br+Br (2P3/2) and C2H4Br+Br*(2P1/2) were clearly assigned based on the calculated results.
As a key material for plant photosynthesis, Chlorophyll is a proxy for vegetation health. Both vegetation indices and three-band model were used to estimate soybean Chl-a concentration with in situ reflectance for soybean canopy. Furthermore, modified vegetation indices are optimized through interactive data language (IDL) to improve soybean Chl-a estimation accuracy. The results show that three-band model is an effective approach for estimating soybean Chl-a. Compared to the models based on both the original and modified vegetation indices, the three-band model achieves better performance with higher coefficient of determination (R2=0.81).
The free-floating population of Enteromorpha prolifera, which results in the blooms in Yellow Sea, has remarkable phenotypic variations compared to the attached population. We applied methylation-sensitive restriction fingerprinting (MSRF) to E. prolifera for methylation polymorphism with methylation-sensitive enzyme digestion. Our results showed that the free-floating sample might be abnormally hypermethylated at BstUI sites. It is suggested that these changes at epigenetic level may promote the rapid adaptation of E. prolifera to free-floating lives in Yellow Sea.
Taking the central Jilin province as a case, we explore spatial-temporal evolution of economic pattern and driving mechanisms in this area. From 1995 to 2010, the disparity shows an inverse-U shape. Changchun and Jilin keep being high-speed economic development regions, and the trend that high-speed economic development regions gather in Changchun, Jilin, and Songyuan becomes significant. The driving mechanisms are identified as the following aspects: basis of historical development, policies on regional development, promotion of market economy, driving effect of industrial cluster and diffusion, and support of talents and technology.
By selecting some county-level administrative districts as the study units and using SPSS16.0 and ArcGIS9.3,we analyze the spatial and temporal patterns of regional economic disparity in Songhua River basin on the basis of per capita GDP during the period from 2001 to 2011. The results show that:1)the total economic disparities and polarization at county level have decreased,and the integral economic disparities are contributed by the inside disparities; 2)the disparity between the upper and lower reaches greatly changed after the developments during these years,Songyuan as a secondary economic growth pole formed gradually,and the spatial distribution changed from the gradient distribution to a "dual-core" structure which consists of Changchun-Jilin and Songyuan; and 3)resource, industrial structure, and policy are the main causes of the regional economic disparity.
Economic growth and urbanization level in Xinjiang have been gradually increasing since 1978. Economic growth is the Granger causal reason for the comprehensive indexes of the urbanization level and the ecological environment pressure. The contribution rate of G to U is continuously decreasing, but that of G to P is continuously rising. Based on the long-term forecast, the explanatory power of G to P will be improved. We should continue to improve the energy resource utilization efficiency and environmental investment level, in order to reduce the ecological environment pressure during the process of economic growth.
The response of different soil layers to different precipitations in both BSC and NBSC sites were analyzed using EC-5 soil moisture sensor during the whole rainy season. The results show that: 1) regardless of precipitation size the presence of BSC hindered the infiltration of precipitation, and this situation was more obvious in small precipitations; 2) most of the absorbing roots of A. ordosica were within the 40 cm soil, and the development of BSC caused serious impediment when the precipitation size was the less than 20 mm, which would result in the recession of A. ordosica in the fixed sand dunes if things continue in this way; and 4) the change of precipitation pattern would have an important impact on soil moisture and vegetation succession.
We establish an evaluation index system, and we evaluate the spatial differences and analyze the major influential factors for the sustainable livelihoods of peasant household in Liangshan prefecture. A brief comparison on the sustainable livelihoods of peasant household is made between Liangshan prefecture and Sichuan province. Additionally, the development level is closely related to the regional resources and environment conditions. Spatial autocorrelation model analysis reveals that there are significant spatial autocorrelations for the sustainable livelihoods of peasant household in Liangshan. Finally the measures are put forward to improve the ability of sustainable livelihoods of peasant household in mountain settlement.
A moving target ISAR imaging method based on compressed sensing (CS) theory is presented. Random pulse repetition frequency is used to meet the requirements of both CS theory and ISAR target detection. This ISAR imaging method based on random pulse repetition frequency and CS theory is aimed at solving the Doppler ambiguity problem brought by moving target in ISAR observation model. The effects of the change range of the random interval and the minimum of the change step on the pesformance of the method are analyzed. The validity of the proposed method is testified by the simulation and applications.
We propose an edge detection algorithm of SAR images based on dual-tree complex wavelet transform. We use the oriented gradient of histogram method to calculate the gradient matrix on all complex wavelet subbands, and acquire the global matrix based on the directional selectivity and multi-scale property of dual-tree complex wavelet transform. The edges are extracted by thresholding the matrix. The proposed algorithm effectively detects significant edges, and it is robust to the speckle noise, intensity inhomogeneity, and blurred boundaries of SAR images. The experimental results show effectiveness of the proposed algorithm.
We present a novel relay selection algorithm in amplify-and-forward relay network with one source node, one destination, and multiple relay nodes. When the channel state information (CSI) of the first hop used for selection is outdated, closed-form expression for the system outage probability is derived. Then we propose a relay selection algorithm with assistance of the channel correlation coefficient, which aims at minimizing the system outage probability. The numerical simulation results show that the proposed strategy brings significant performance gain compared to the conventional partial relay selection strategy.
We consider the OFDM system simultaneously corrupted by the clipping distortion and quantization distortion. Joint optimization of such an OFDM system from the standpoint of end-to-end link is investigated. The corresponding multi-variable and multi-object optimization models are established and the Pareto front is obtained through software simulation by employing the NSGA-Ⅱ algorithm. Results show that at USQ width of 1 or 2 bit, more than 5dB peak-to-average power ratio gain is achieved while the loss of the average channel capacity is much less than 0.1 bps/Hz. Meanwhile, the theoretical BER of the OFDM system is derived and its accuracy is verified by software simulations.
In the field of academic recommendation, changes in learner's preferences and academic trends with time affect the accuracy of academic recommendation systems. Most of the existing recommendation methods do not consider the time factor. We propose the dynamic transfer chain (DTC) to model users' preferences and academic trends over time. Based on DTC framework, we present a novel temporal academic recommendation algorithm (SVD&DTC) which combines singular value decomposition (SVD) and DTC together. Finally, we evaluate the effectiveness of the method using datasets on SeekSearch, and the results show a 3.89% improvement over the previous start-of-the-art.
JIT(just-in-time) compilation technique improves the efficiency of code execution. In almost all web browsers as well as Java, Perl, Python, Ruby and Flash, JIT is implemented into their already complex code base. However, for high effectiveness, JIT engines allocate memory with RWX (readable, writable, and executable) permissions to predictable offsets, which goes against DEP (data execution prevention) and ASLR (address space layout randomization). We first analyze two existed JIT defense tools and show the defects of them. Based on our analysis, we design and implement an approach named Ares to protect JIT engines from normal JIT-based attack without modifying JIT engines' source code. Experiments show that our approach guarantees the safety of JIT compilation and the overhead is acceptable.
An adaptive-energy-threshold-based energy-efficient on-demand multicast routing protocol (EMRP) for wireless Ad Hoc and sensor networks is proposed to prolong the network lifetime. Based on the network energy status, EMRP adaptively calculates an energy threshold which protects the nodes with low remaining energy by discouraging their engagement in multicast tree. Further, it adopts destination-driven strategy to efficiently reduce the multicast tree size to save the energy for a multicast task. EMRP does not require nodes to keep global or local network state information. It has low overheads and is easy to implement. Simulation results show that EMRP greatly reduces the energy cost for per-packet delivery and prolongs the network lifetime.
Based on level-2 data from CE-318 installed at Taihu Lake(one of AERONET sites) from September 2005 to September 2010, variation of single scattering albedo (SSA) with time and the frequency distribution features were analyzed. Maximum and minimum monthly mean values of SSA were observed in August (0.95±0.03) and December (0.87±0.03), respectively. Maximum and minimum of seasonal mean value of SSA were observed in summer (0.94±0.03) and winter (0.88±0.04), respectively. Frequency distribution of SSA shows that the peak value is between 0.9 to 0.92, with a yearly average value of 0.90. The aerosol over Taihu Lake should be classified as moderate absorbing aerosol.