Analysis of pseudo-random number generators in QMC-SSE method

In the quantum Monte Carlo(QMC)method,the pseudo-random number generator(PRNG)plays a crucial role in determining the computation time.However,the hidden structure of the PRNG may lead to serious issues such as the breakdown of the Markov process.Here,we systematically analyze the performance of different PRNGs on the widely used QMC method known as the stochastic series expansion(SSE)algorithm.To quantitatively compare them,we introduce a quantity called QMC efficiency that can effectively reflect the efficiency of the algorithms.After testing several representative observables of the Heisenberg model in one and two dimensions,we recommend the linear congruential generator as the best choice of PRNG.Our work not only helps improve the performance of the SSE method but also sheds light on the other Markov-chain-based numerical algorithms.

Estimating energy release performance of oxidizer-activated aluminum fuel particles under ultrafast stimulus

Aluminum(Al) particles are good fuel additives to improve the energy output performances of explosives. Under detonation environment, reaction delay of Al particles plays a key role in the energy release efficiency. Up to date, reaction delay of Al particles is still limited by the efficiency of mass and heat transfer from oxidizers to Al particles. To address this issue, a homogeneous fuel-oxidizer assembly has recently become a promising strategy. In this work, oxidizer-activated Al fuel particles(ALG) were prepared with glycidyl azide polymer(GAP) as the oxidizer. The ALG was in uniform spherical shape and core-shell structure with shell layer of around 5 nm which was observed by scanning electron microscope and transmission electron microscope. The localized nanoscale mid-IR measurement detected the uniform distribution of characteristic absorption bond of GAP in the shell layer which confirmed the homogenous fuel-oxidizer structure of ALG. A thermal gravimetric analysis of ALG at ultrafast heating rate of 1000℃/min under argon atmosphere was conducted. The decomposition of GAP finished much earlier than that of GAP at heating rate of 10℃/min. Under ultrafast high laser fluence, the reaction response of ALG was characterized and compared with that of micro-sized Al(μAl). With the increase of laser energy, the propagation distance of the shock wave increased. However, the velocity histories were nearly the same when energies were lower than 299 mJ or higher than 706 mJ. The propagation distance of the shock wave for ALG was 0.5 mm larger than that for μAl at 2.1 μs. The underwater explosion showed the peak pressure and the shock wave energy of the ALG-based explosive were both higher than those of the μAl-based explosive at 2.5 m. This study shows the feasibility to improve the energy release of Al-based explosives via using the oxidizer-activated Al fuel particles with energetic polymer as the oxidizer.

In vivo synaptic transmission in the zebra finch high vocal center and robust nucleus of the arcopallium after different stimulus patterns

BACKGROUND： Electrophysiological studies using brain slices have revealed that the developmental regulation of synaptic plasticity in vocal learning pathway is essential for song learning in zebra finches. Publications reporting in vivo electrophysiological investigation are scarce. Many aspects of neural mechanisms underlying song learning and production still remain uncertain. OBJECTIVE： To observe the efficacy of paired pulses and the effect on synaptic transmission induced by low-frequency stimulations, high-frequency stimulations, and theta-burst stimulations. DESIGN, TIME AND SETTING： A comparative observation. The experiment was conducted from October 2006 to October 2007 in the Neurophysiology Laboratory of South-China Normal University. MATERIALS： Twenty-four adult male zebra finches were supplied by the Department of Animal Experiment of College of Life Sciences, South China Normal University. A SEN-7203 stimulator （NIHON KOHDEN）, as well as a DSJ-731WF microelectrode amplifier and DSJ-F amplifier （provided by South-China Normal University）, were used to stimulate and record, respectively. METHODS： Animals were randomly divided into low-frequency, high-frequency, and theta-burst frequency stimulation groups. After recording evoked potentials, an input-output curve was evaluated. Subsequently, the efficacy of paired pulses with different stimulus intensity （1/3, 1/2, 2/3, or 3/4 of the value that induced the largest synaptic response）, as well as interpulse intervals （50, 75, and 100 ms）, was measured in each group. The test stimulus intensity was set to a level that evoked 1/2 or 1/3 amplitude of the maximum response. MAIN OUTCOME MEASURES： Changes in amplitude, slope, and area of evoked potentials elicited by different stimulus patterns. RESULTS： （1） Efficacy of paired pulses： there was significant paired-pulse facilitation in the high vocal center and robust nucleus of the arcopallium （HVC-RA） synapse. Efficacy decreased when paired-pulse intervals or stimulus intensities were increased. （2） Low-frequency stimulations at 1 Hz had a negligible effect on efficacy of synaptic transmission, while 5 Hz depressed synaptic transmission for only 5 minutes. （3） High-frequency stimulations at 50 Hz or 100 Hz induced synaptic depression that lasted for up to 30 minutes. （4） Theta-burst stimulation depressed synaptic transmission efficiency significantly for about 10 minutes. However, in contrast to low-frequency or high-frequency stimulations, theta-burst stimulations also induced slight potentiation of synaptic transmission for up to 60 minutes following depression phase, although the slope or area did not change. CONCLUSION： Paired pulses induced a remarkable efficacy of paired pulses in the high vocal center and robust nucleus of the arcopallium pathway. Low-frequency, high-frequency, or theta-burst frequency stimulation did not induce long-lasting changes in synaptic transmission.

Energy distribution and effective components analysis of 2^(n) sequence pseudo-random signal

In order to extract usable harmonics from real 2^(n) sequence pseudo-random data,a technical method is proposed.An equation for predicting the average amplitude of the main frequencies is proposed to guide the choice of signal type for different exploration tasks.By the threshold of the amplitude of the transmitted signal,a set of candidate frequencies are first selected.Then,by operating a spectrum envelope method at these candidate frequencies on received data,effective components in data are extracted.A frequency density calculation method is proposed based on a logical number summation method,to reasonably characterize the frequency density in different frequency bands.By applying this method to real data in Sichuan,China,with signal Type 13,75 effective components are extracted,including both main frequencies and harmonics.The result suggests that the number of effective frequencies in the 2^(n) sequence pseudo-random signal can be increased by extracting usable harmonics,without any additional fieldwork.

Application of pseudo-random frequency domain electromagnetic method in mining areas with strong interferences

Due to the strong electromagnetic interferences and human interference,traditional electromagnetic methods cannot obtain high quality resistivity data of mineral deposits in Chinese mines.The wide field electromagnetic method(WFEM),in which the pseudo-random signal is taken as the transmitter source,can extract high quality resistivity data in areas with sever interference by only measuring the electric field component.We use the WFEM to extract the resistivity information of the Dongguashan mine in southeast China.Compared with the audio magnetotelluric(AMT)method,and the controlled source audio-frequency magnetotelluric(CSAMT) method,the WFEM can obtain data with higher quality and simpler operations.The inversion results indicate that the WFEM can accurately identify the location of the main ore-body,which can be used for deep mine exploration in areas with strong interference.

Effect of Touch stimulus on the Expression of C-fos and TrkA in Spinal Cord Following Chronic Constriction Injury of the Sciatic Nerve in Rats

Summary: To study the mechanism of the innoxious touch-stimulus on the modulation of hyperalgesia and the expression of the C-fos and the nerve growth factor (NGF) receptor-TrkA in the spinal dorsal horn neurons following the chronic constriction injury (CCI) of the sciatic nerve in rats, 60 female Sprague-Dawley rats were randomly divided into sham-operation group and CCI group, with each group being further divided into 3 subgroups on the 7th,14th and 28th day after operation (n=10). The mechanical and the thermal withdrawal threshold were assessed following the touch stiumulation after the CCI, immunohistochemical methods were employed to observe the expression of the C-fos and TrkA in spinal dorsal horn. Our results showed that the hyperalgesia appeared on the 4th day and reached the maximal level on the 14th day after operation. The expression of the C-fos also increased significantly and reached its maximal level on the 14th day after the touch-stimulus. Meanwhile, the TrkA expression was elevated significantly in both groups, as compared with basic data, and the difference was statistically significant (P<0.05). It is concluded that the level of the C-fos expression changed with the paw withdrawal threshold variation and increased markedly following the innoxious touch-stimulus. The expression of the TrkA receptors also increased gradually following the development of the neuropathic pain. The results suggest that C-fos may play a crucial role in the development of the hyperalgesia in the earlier-time of the neuropathic pain, but TrkA receptors may be involved in the long-lasting adaptive changes of the central pathway in neuropathic pain.

Stability of N-LTNR exposing to severe thermal stimulus

The thermal stability of normal lead styphnate（ N-LTNR） has been studied under severe temperature（- 70 ℃- 130 ℃ for 5 days） with a high optical microscope and camera were used to observe apparent morphology and thermal gravimetric analysis was applied to study the physical changes. In addition,vacuum stability analysis,differential scanning calorimetry（ DSC）,thermal gravimetric analysis（ TGA） and purity analysis were utilized to study the chemical changes. As well as flame sensitivity analysis were used to investigated the explosive changes. The results show that N-LTNR has good chemical stability and fire function stability between- 70 ℃ and 130 ℃,but poor physical stability. When the temperature was exceeded than 110 ℃,the N-LTNR lost crystal water which made the energetic material become darker in color,lager in volume and lighter in weight（ 3. 416%） when the temperature was below- 40 ℃,the phenomenon of crystal broking and jumping happened.

Ultrafast Infrared Spectroscopic Study of Microscopic Structural Dynamics in pH Stimulus-Responsive Hydrogels

Hydrogels show versatile properties and are of great interest in the fields of bioelectronics and tissue engineering.Understanding the dynamics of the water molecules trapped in the three-dimensional polymeric networks of the hydrogels is crucial to elucidate their mechanical and swelling properties at the molecular level.In this report,the poly(DMAEMA-co-AA)hydrogels were synthesized and characterized by the macroscopic swelling measurements under different pH conditions.Furthermore,the microscopic structural dynamics of pH stimulus-responsive hydrogels were studied using FTIR and ultrafast IR spectroscopies from the viewpoint of the SCN-anionic solute as the local vibrational reporter.Ultrafast IR spectroscopic measurements showed the time constants of the vibrational population decay of SCN-were increased from 14±1 ps to 20±1 ps when the pH of the hydrogels varied from2.0 to 12.0.Rotational anisotropy measurements further revealed that the rotation of SCNanionic probe was restricted by the three-dimensional network formed in the hydrogels and the rotation of SCN-anionic probe cannot decay to zero especially at the pH of 7.0.These results are expected to provide a molecular-level understanding of the microscopic structure of the cross-linked polymeric network in the pH stimulus-responsive hydrogels.

Pseudo-Random Sequences Generator Based on Discrete Hyperchaotic Systems

We first design a discrete hyperchaotic system via piece-wise linear state feedback. The states of the closed loop system are locally expanding in two directions but absolutely bounded on the whole, which implies hyperchaos. Then, we use three suchlike hyperchaotic systems with different feedback gain matrices to design a pseudo-random sequence generator (PRSG). Through a threshold function, three sub-sequences generated from the output of piecewise linear functions are changed into 0-1 sequences. Then, followed by XOR operation, an unpredictable pseudo-random sequence (PRS) is ultimately obtained. The analysis and simulation results indicate that the PRS, generated with hyperchaotic systems, has desirable statistical features.

Blind parameter estimation of pseudo-random binary code-linear frequency modulation signal based on Duffing oscillator at low SNR

Conventional parameter estimation methods for pseudo-random binary code-linear frequency modulation(PRBC-LFM)signals require prior knowledge,are computationally complex,and exhibit poor performance at low signal-to-noise ratios(SNRs).To overcome these problems,a blind parameter estimation method based on a Duffing oscillator array is proposed.A new relationship formula among the state of the Duffing oscillator,the pseudo-random sequence of the PRBC-LFM signal,and the frequency difference between the PRBC-LFM signal and the periodic driving force signal of the Duffing oscillator is derived,providing the theoretical basis for blind parameter estimation.Methods based on amplitude method,short-time Fourier transform method,and power spectrum entropy method are used to binarize the output of the Duffing oscillator array,and their performance is compared.The pseudo-random sequence is estimated using Duffing oscillator array synchronization,and the carrier frequency parameters are obtained by the relational expressions and characteristics of the difference frequency.Simulation results show that this blind estimation method overcomes limitations in prior knowledge and maintains good parameter estimation performance up to an SNR of-35 dB.

Exogenous Protein as an Environmental Stimulus of Biofilm Formation in Select Bacterial Strains

A screening of environmental conditions that would elicit robust biofilm in a collection of Serratia marcescens isolated from soil revealed that exogenous milk protein increased biofilm productivity up to ten-fold. A select screening of fish pathogens, freshwater and human isolates identified several other species that responded similarly to exogenous protein. The optimal protein concentration was species specific;S. marcescens at 5% milk protein, Aeromonas sp. at 2% - 3%, Flavobacterium columnare at 1% and Pseudomonas aeruginosa at 0.1% - 0.4%. Media supplemented with milk protein also increased the cell counts in biofilm as well as the protein incorporated into the biofilm matrix. These data suggest that relatively high concentrations of exogenous protein may serve as an environmental trigger for biofilm formation, particularly for pathogenic bacteria exposed to relatively high concentrations of protein in bodily fluids and mucosal surfaces.

HIERACHICAL STRUCTURES FOR GENERATING PSEUDO-RANDOM SEQUENCES AND ARRAYS

This paper proposes new hierarchical structures for generating pseudorandom sequences and arrays. The principle of the structures is based on a new concept-multi-interleaving. It is the generalization of normal sequence decimation(sampling). The kernal of the structures is a lower speed linear feedback shift register together with several high speed time-division multiplexers arranged hierarchically. These new structures have much higher speed compared with that of other schemes proposed before.

Feather Vibration as a Stimulus for Sensing Incipient Separation in Falcon Diving Flight

Based on our preceding studies on the aerodynamics of a falcoperegrinus in diving flight along a vertical dam it is known that even when the body shape of the bird is rather streamlined in V-shape some feathers tips may elevate in certain regions of the body. These regions were identified in wind tunnel tests for typical diving flight conditions as regions of locally separated flow. A life-size model in V-shape of a falcoperegrinus with artificial feathers fixed along the body was studied in a wind tunnel to focus on the fluid-structure interaction of feathers located in this sector. The distal ends of the feathers show flow-induced vibrations at typical flight conditions which grow linear in amplitude with increasing angle of incidence until incipient separation. In light of the proven existence of vibration-sensitive mechanoreceptors in the follicles of secondary feathers in birds it is hypothesized that this linear amplitude response offers the bird to sense the angle of incidence during the diving flight using the vibration magnitude as sensory stimulus. Thus the bird in streamlined shape has still a good measure to control its attitude to be in the narrow window of safe angle of incidence. This might have implications also for other birds or technical applications of airfoil sensors regarding incipient separation detection.

BIT COMMITMENT USING PSEUDO-RANDOM SYNTHESIZER

This paper presents two practical message commitment schemes: one is suitable for committing many bits, and another is useful for committing any bit-long message. They are provably secure based on pseudo-random synthesizers. In these schemes, the sender may be unbounded to polynomial time and the receiver is bounded. The advantage of these schemes is that the secure parameter may be small.

Pseudo-Random Coding Side-Lobe Suppression Method Based on CLEAN Algorithm

A pseudo-random coding side-lobe suppression method based on CLEAN algorithm is introduced.The CLEAN algorithm mainly processes pulse compression results of a pseudo-random coding,and estimates a target＇s distance by a method named interpolation method,so that we can get an ideal pulse compression result of the target,and then use the adjusted ideal pulse compression side-lobe to cut the actual pulse compression result,so as to achieve the remarkable performance of side-lobe suppression for large targets,and let the adjacent small targets appear.The computer simulations by MATLAB with this method analyze the effect of side-lobe suppression in an ideal or noisy environment.It is proved that this method can effectively solve the problem due to the side-lobe of pseudo-random coding being too high,and can enhance the radar＇s multi-target detection ability.

Who Will Benefit from China’s Stimulus?

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How the Brain Process Stimulus-Response Conflict? New Insights from Lateralized Readiness Potentials Scalp Topography and Reaction Times

Stimulus-Response Compatibility (SRC) refers to the fact that some tasks are performed easier and better than others because of the way stimuli and responses are paired with each other. To assess the brain responses to stimulus-response conflicts, we investigated the behavioral (accuracy and Reaction Times: RTs) as well as the physiological response (Lateralized Readiness Potentials: LRP) modulations in a positional blocked and a conditional mixed design in twelve university students. Results revealed that the performance was less accurate and the RTs, as well as the LRP onset, were delayed under the mixed conditional design. A greater compatibility effect was also noted on accuracy, RTs and LRP onset latency in the mixed design. Consistent with these findings, smaller peak activation at fronto-central areas suggests that more selective inhibition is needed in a mixed design context. Despite a smaller activation, the topographical distribution is similar in both designs. These results indicate that the translation time between stimulus- and response codes are greater under the mixed instruction, while the similar LRP topography suggests that common neural structures underlie LRPs in response to both type of designs.

MEASUREMENT OF AMPLITUDE AND DELAY OF STIMULUS FREQUENCY OTOACOUSTIC EMISSIONS

Although stimulus frequency otoacoustic emissions (SFOAEs) have been used as a non-invasive measure of cochlear mechanics, clinical and experimental application of SFOAEs has been limited by difficulties in accurately deriving quantitative information from sound pressure measured in the ear canal. In this study, a novel signal processing method for multicomponent analysis (MCA) was used to measure the amplitude and delay of the SFOAE. This report shows the delay-frequency distribution of the SFOAE measured from the human ear. A low level acoustical suppressor near the probe tone significantly suppressed the SFOAE, strongly indicating that the SFOAE was generated at characteristic frequency locations. Information derived from this method may reveal more details of cochlear mechanics in the human ear.

Adding Pseudo-Random Test Sequence Generator in the Test Simulator for DFT Approach

This paper presents modified version of a realistic test tool suitable to Design For Testability （DFT） and Built-ln Self Test （BIST） environments. A comprehensive tool is developed in the form of a test simulator. The simulator is capable of providing a required goal of test for the Circuit Under Test （CUT）. The simulator uses the approach of fault diagnostics with fault grading procedures to provide the optimum tests. The current version of the simulator embeds features of exhaustive and pseudo-random test generation schemes along with the search solutions of cost effective test goals. The simulator provides facilities of realizing all possible pseudo-random sequence generators with all possible combinations of seeds. The tool is developed on a common Personal Computer （PC） platform and hence no special software is required. Thereby, it is a low cost tool hence economical. The tool is very much suitable for determining realistic test sequences for a targeted goal of testing for any CUT. The developed tool incorporates flexible Graphical User Interface （GUI） procedures and can be operated without any special programming skill. The tool is debugged and tested with the results of many bench mark circuits. Further, this developed tool can be utilized for educational purposes for many courses such as fault-tolerant computing, fault diagnosis, digital electronics, and safe-reliable-testable digital logic designs.

Stimulus 2009(Part Two)——Measures facilitate light & textile industry

Support SMEs Increase the scale of financial supports at various levels to support SMEs, sustain light & textile projects with promising market prospect, notable driving of employment and remarkable social benefits, and step up investments in construction of credit guarantee system and service