Intensity range as a function of task and training

This study examined intensity range as a function of elicitation task (reading and automatic speech sequences), musical training, and the interaction between task and musical training in 31 college students. The results indicated significant differences in loudness range by experiental task. Intensity range for the descending automatic sequence was significantly greater than that for the ascending and reading tasks. While the overall effect of musical training was nonsignificant, there was a significant interaction between task and training, with musicians having a significantly greater mean range on the ascending task. A comparison between ascending and descending tasks indicated a significant mean difference between lower limits and no significant mean difference between upper limits. The range for the reading probe was located approximately in the middle of the total available intensity range.     

Analysis of detectable range of multiple-slit streak tube imaging lidar

Multiple-slit streak tube imaging lidar is a promising flash imaging system. Its detectable range, affected by the detection of the unit sensitivity, operating mode, and visibility, are critical factors for the system design and applications. In order to discuss the lidar range measurement performance, a lidar equation based on the Lambert law is analyzed, and the relationship between the lidar detectable range and the emission power is simulated at different levels of visibility; the result shows that the detectable range of lidar developed in our laboratory reaches 2,500 m for a 23 km visibility. Outfield experiments were carried out to evaluate the system performance; a clear stripe image for a target located 1386 m away was gained under the condition of 15 km visibility. Finally, parameters that affect the lidar detectable range are discussed, and relevant methods to improve the lidar performance are proposed.     

基于多重分形去趋势波动分析法的交通流多重分形无标度区间自动识别方法

无标度区间是时间序列在统计意义上存在分形自相似性的尺度范围,是交通流多重分形特征研究中的重要组成部分.为解决交通流多重分形研究中多重分形去趋势波动分析法(multi-fractal detrended fluctuation analysis,MF-DFA)缺乏有效识别无标度区间方法的问题,本文在分析算法过程中交通流波动函数对数曲线突变点性质的基础上,结合传统无标度区间识别方法的构建思想,建立基于MF-DFA算法的无标度区间自动识别方法.以北京市二环快速路外环方向的部分道路为例开展实例研究,通过与传统无标度区间识别方法的结果对比,验证新方法的有效性.研究结果表明:本文方法能自动识别交通流多重分形无标度区间,且稳定性好;案例研究可知交通流短时间内波动较小、自相似性较强,随着研究时间段变长、交通流波动逐渐变大,自相似性逐渐消失,进一步解释了交通流无标度区间的有限性.     

Range of Er ions in amorphous Si

We have measured the range and range straggling for energetic 100-900 keV Er ions in amorphous Si by means of Rutherford backscattering followed by spectrum analysis. The results are compared with other experimental data and Monte Carlo (SRIM-2003) calculations. Our experimental results show that, although the measured values for both range and range straggling exceed the SRIM predictions, they are nevertheless consistent with trends that have been previously observed. We see no anomalous trends in range and range straggling parameters for the rare earth ions for implant energies E ≥ 100 keV. We present a detailed consideration of ⁴He stopping powers in Si due to its crucial impact on RBS range measurements.     

On the continuity of the critical value for long range percolation in the exponential case

We show that for a long range percolation model with exponentially decaying connections, the limit of critical values of any sequence of long range percolation models approaching the original model from below is the critical value for the original long range percolation model. As an interesting corollary, this implies that if a long range percolation model with exponential connections is supercritical, then it still percolates even if all long bonds are removed. We also show that the percolation probability is continuous (in a certain sense) in the supercritical regime for long range percolation models with exponential connections.Research supported by a grant from the Swedish National Science Foundation.     

一种新的激光雷达距离像噪声抑制方法

主要针对激光雷达距离像的距离反常噪声抑制问题,阐述了激光雷达距离像的噪声原理,分析了应用传统中值滤波方法抑制距离反常噪声的缺陷,提出了基于包围准则的自适应中值滤波算法。该方法首先根据包围准则检测噪声,对5×5滤波窗口内的像素值进行排序差分;然后选择低于门限长度最长的连续差分值对应的像素值作为距离正常值;最后运用中值滤波和加权均值滤波进行噪声抑制。实验结果表明,该方法有效抑制了距离反常噪声,且较好地保护了距离图像中目标的边缘细节,均方根误差分别比3×3和5×5窗口中值滤波法减少了27.1%和9.1%。     

Long range corrections for computer simulations of adsorption

Long range corrections are routinely applied to simulations of bulk fluids by assuming that the radial distribution function is unity beyond a certain cutoff radius for pairwise interactions. Similar long range corrections for gas-solid interactions in adsorption frequently are ignored because of the anisotropic structure of the solid. However, the error associated with assuming isotropy beyond the cutoff radius is small compared with the magnitude of the long range correction. The long range correction to the Henry constant for a cutoff radius of 13 Å is 14% for CH₄ and 70% for SF₆ for adsorption in silicalite at 298 K. The large errors incurred by neglecting long range corrections can be concealed by increasing the well depth of the gas-solid interaction, but this approximation reduces the accuracy and portability of the potential parameters. Consistency in the cutoff radius is more important than the inclusion or neglect of long range corrections to the energy.     

相位补偿算法对提高太赫兹雷达距离像分辨率的研究

介绍了0.2 THz频率步进雷达系统以及获得一维距离像的方法,并利用0.2 THz雷达对角反射器进行距离像分辨率实验,分析了频率步进信号相位不一致对一维距离像以及分辨率的影响,提出了回波相位补偿的方法.经过相位补偿后,目标距离像分辨率和信噪比都显著提高,分辨率达到了厘米量级.仿真和实验结果表明,宽带太赫兹频率步进雷达经过相位补偿,可以对目标进行高分辨率成像,从而为太赫兹雷达二维和三维成像奠定了基础.     

ICCD紫外告警系统能量传递过程分析

从目标的辐射能量传递出发,针对紫外告警系统的作用距离估算问题,分析了辐射照度与辐射通量两种形式下的能量在ICCD紫外告警系统中的传递过程。分别将上述过程用于实例的计算,得到了CCD靶面能量与作用距离的关系。此过程的分析为建立基于点源探测和基于成像探测的紫外告警系统作用距离估算模型提供了理论依据。     

Modification of short-range repulsive interactions in ReaxFF reactive force field for Fe-Ni-Al alloy

The short-range repulsive interactions of any force field must be modified to be applicable for high energy atomic collisions because of extremely far from equilibrium state when used in molecular dynamics (MD) simulations. In this work, the short-range repulsive interaction of a reactive force field (ReaxFF), describing Fe-Ni-Al alloy system, is well modified by adding a tabulated function form based on Ziegler-Biersack-Littmark (ZBL) potential. The modified interaction covers three ranges, including short range, smooth range, and primordial range. The short range is totally predominated by ZBL potential. The primordial range means the interactions in this range is the as-is ReaxFF with no changes. The smooth range links the short-range ZBL and primordial-range ReaxFF potentials with a taper function. Both energies and forces are guaranteed to be continuous, and qualified to the consistent requirement in LAMMPS. This modified force field is applicable for simulations of energetic particle bombardments and reproducing point defects' booming and recombination effectively.     

High-temperature thermoelectric behavior of lead telluride

Usefulness of a material in thermoelectric devices is temperature specific. The central problem in thermoelectric material research is the selection of materials with high figure-of-merit in the given temperature range of operation. It is of considerable interest to know the utility range of the material, which is decided by the degrading effect of minority carrier conduction. Lead telluride is among the best-known materials for use in the temperature range 400–900 K. This paper presents a detailed theoretical investigation of the role of minority carriers in degrading the thermoelectric properties of lead telluride and outlines the temperature range for optimal performance.     

Size of two-body weakly bound objects: short versus long range potentials

The variation of the size of two-body objects is investigated, as the separation energy approaches zero, with both long range potentials and short range potentials having a repulsive core. It is shown that long range potentials can also give rise to very extended systems. Except for the l = 0 state, the asymptotic laws differ according to the range of the potential. For short range potentials defined by two and three parameters, their sensitivity to the shape and length is studied. These ideas as well as the transition from the short to the long range regime for the l = 0 case are illustrated using the Kratzer potential.     

Discussion on the usefulness of dose dynamic multi-leaf collimator-based plan to overcome dose limit of spinal cord in high-dose radiotherapy

In this study, the conventional plan was compared with the plan that was based on a dose dynamic multi-leaf collimator (MLC), and a dose dynamic MLC was used to evaluate its usefulness. Then, this study examined if it was possible to perform a high-dose radiation therapy by adjusting the dose limit of the spinal cord when the dose dynamic MLC-based plan was used. First of all, linear accelerator was used to compare the conventional plan with the dose dynamic MLC-based plan. Then, the study was conducted in two methods in order to examine the proper range of the shield for the spinal cord when the dose dynamic MLC was used to adjust the dose of the spinal cord. In the first method, X-omat film was used to perform film dosimetry. In the second method, radiation treatment planning (RTP) system was used to find out the proper range among 0, 3, 6, and 9 mm. When film scan was performed in the each range, respectively, from the spinal cord and under the same conditions, it was confirmed to be appropriate to use the range of 3 mm. When the RTP system was used to perform planning in the shield range of each range, respectively, from the spinal cord, dose-volume histogram (DVH) was a slight difference could be found in the region from 25% to 35%. On the contrary, no radiation exposure was found in the region of 35% or higher for all of the each range. Consequently, if MLC is selected in consideration of the planning target volume (PTV), the most proper value can be obtained by selecting the range of 3 mm. Next, the DVH was compared to examine the relationship in PTV when the each range was used for planning. All of the ranges showed the same pattern up to the point of 90%. However, the results were different in the region of higher than 90% because the dose was low for the spinal cord, and a relatively useful dose was used for PTV when the range was 3 mm.     

The effect of different ion stopping models on calculated parameters of the radiation damage of materials

Direct numerical solution of the Boltzman transport equation for incident ions and knocked-off atoms of the target is applied for range and damage calculations. The influence of physical parameters in a model of ion stopping in matter on the obtained range and damage distribution is investigated in the range of ion energies from 1 KeV to 1 MeV. All the examined interatomic potentials give close values of mean depths and higher moments of range and damage distributions. The influence of differences in electronic stopping is also studied. The obtained results are compared with experimental data and the results of other calculations.     

Beam forming optic aberrations’ impact on maximum range of semiconductor laser based rangefinders

Miniature rangefinding modules based on pulsed semiconductor laser technology are becoming more and more popular components of a variety of modern optoelectronics devices where precise, fast and eye-safe range estimation is needed. Current trends associated with minimization of both physical dimensions and cost of such modules lead to the design approach relying on exact meeting the requirements of a given application, concerning the spatial resolution and especially the maximum range. Optical components of a rangefinder cover a substantial part of its cost and determine its overall dimensions, but primarily — the indigenous parameters of the transmitter and receiver trains are crucial for the maximum measurable range. The quantitative analysis of transmitter optics aberrational characteristics impact on signal-to-noise ratio range dependence and thus the maximum range of a laser rangefinder is presented in the paper. Modern optical fabrication technology offers a huge range of solutions, changing in imaging/projecting characteristics which implies the price level as well. Rangefinder optics has a very specific task which sometimes makes it unreasonable to fight for the diffraction limited performance. The article provides the approach how to determine the acceptable level of optical aberrations which still does not degrade the measurable range significantly.     

Quick focusing of imaging optics using micromachined adaptive mirrors

Inexpensive micromachined varifocal mirrors, providing a very wide range of focal distance control are described. The focal distance of a mirror with a clear aperture of 1 cm can be controlled in the range ∞ to +0.25 m (four diopters) in a frequency band up to 75 Hz by applying control voltages in the range of 0 to 200 V. Applications for quick focus control in a CCD camera and for direct correction of the accommodation depth of a human eye are reported.     

Range compensation for backscattering measurements in the difference-frequency nearfield of a parametric sonar

Measurement of acoustic backscattering properties of targets requires removal of the range dependence of echoes. This process is called range compensation. For conventional sonars making measurements in the transducer farfield, the compensation removes effects of geometrical spreading and absorption. For parametric sonars consisting of a parametric acoustic transmitter and a conventional-sonar receiver, two additional range dependences require compensation when making measurements in the nonlinearly generated difference-frequency nearfield: an apparently increasing source level and a changing beamwidth. General expressions are derived for range compensation functions in the difference-frequency nearfield of parametric sonars. These are evaluated numerically for a parametric sonar whose difference-frequency band, effectively 1-6?kHz, is being used to observe Atlantic herring (Clupea harengus) in situ. Range compensation functions for this sonar are compared with corresponding functions for conventional sonars for the cases of single and multiple scatterers. Dependences of these range compensation functions on the parametric sonar transducer shape, size, acoustic power density, and hydrography are investigated. Parametric range compensation functions, when applied with calibration data, will enable difference-frequency echoes to be expressed in physical units of volume backscattering, and backscattering spectra, including fish-swimbladder-resonances, to be analyzed.     

Chemical transformations of iron compounds during the process of hard coal pyrolysis

The coal with a very high sulphure content was used as a charge of a reactor for hydropyrolysis processes in the 820–1120 K range and for pyrolysis processes in an argon atmosphere. The results of Mössbauer measurements for the semi-cokes, obtained during hydropyrolysis, showed that the pyrite was transformed to pyrrhotites in the 820–870 K range when it was transformed to metallic iron in the 1000–1120 K range. The pyrolysis in an argon atmosphere leads to decomposition of pyrite to pyrrhotites but the metallic iron was not evidenced in these cokes.     

Measurement of a broad range of Gaussian laser beam diameters using various periodic and aperiodic rulings

A novel analytical approach is proposed for an accurate estimation of a broad range of Gaussian laser beam diameters. The new approach, based on the Fourier transform and the convolution operations, is used to study the performance of most recently proposed periodic and aperiodic rulings. Further, for applications that require extremely small beam diameter measurements, a new Ronchi-like ruling is proposed; while for applications requiring large beam diameters measurements, various aperiodic non-Ronchi rulings are proposed. Furthermore, for spot-size measurement applications, which range from very small to very large beam diameters, a new single aperiodic exponential ruling is proposed. This new ruling eliminates the necessity of using a large number of rulings for measuring a broad range of beam diameters.     

Cross-language differences in fundamental frequency range: a comparison of English and German

This paper presents a systematic comparison of various measures of f0 range in female speakers of English and German. F0 range was analyzed along two dimensions, level (i.e., overall f0 height) and span (extent of f0 modulation within a given speech sample). These were examined using two types of measures, one based on "long-term distributional" (LTD) methods, and the other based on specific landmarks in speech that are linguistic in nature ("linguistic" measures). The various methods were used to identify whether and on what basis or bases speakers of these two languages differ in f0 range. Findings yielded significant cross-language differences in both dimensions of f0 range, but effect sizes were found to be larger for span than for level, and for linguistic than for LTD measures. The linguistic measures also uncovered some differences between the two languages in how f0 range varies through an intonation contour. This helps shed light on the relation between intonational structure and f0 range.