Models to predict the deformation modulus and the coefficient of subgrade reaction for earth filling structures

Determination of deformation modulus and coefficient of subgrade reaction of soils have major importance, whether the projects are in design, and construction or compaction assessment stage of earth filling structures. Plate load test is one of the frequently used method to directly determine the parameters but the method is both costly and time consuming. For this reason, this paper is concerned with the applications of artificial neural networks (ANN) and simple-multiple regression analysis to predict deformation modulus and coefficient of subgrade reaction of compacted soils from compaction parameters (such as maximum dry density (MDD) and optimum moisture content (OMC), field dry density (FDD), and field moisture content (FMC)). Regression analysis and artificial neural network estimation indicated that there are acceptable correlations between deformation modulus and coefficient of subgrade reaction and these parameters. Artificial neural networks model exhibits higher performance than traditional statistical model for predicting deformation modulus and coefficient of subgrade reaction.     

Applying eco-visualisations of different interface formats to evoke sustainable behaviours towards household water saving

The shortage of water resources is a global issue. This study attempts to utilise eco-visualisation interface design to affect users’ water-usage behaviour. Three interface proposals were designed in this study: numeric, water droplet (abstract symbol), and swimming fish (animated image). These three different interface formats range from abstract to figurative and from neutral to affective. A total of 93 subjects were divided into three groups and randomly performed designated dishwashing tasks twice. One of the tasks was completed without the assistance of any interface, whereas the other involved applying one of the three interface formats with eco-visualisations. In this study, the Self-Assessment Manikin scales, the System Usability Scale, and the Questionnaires for User Interaction Satisfaction were used to measure the emotional dimensions and perceived usability and to record the differences in water usage volume. The results indicated that the emotional valence evoked by the animated image interface was significantly higher than that by the numeric interface. The effect of the numeric interface formats on the subjects focused on emotional arousal, whereas other interfaces emphasised emotional valence. With the aid of the eco-visualisations of interface design, the evoked emotional response and enhanced usability could help improve sustainable behaviours towards water saving.     

Comparison of image reconstruction by using near‐field and far‐field data for an imperfect conductor

Image reconstruction by using near‐field and far‐field data for an imperfectly conducting cylinder is investigated. A conducting cylinder of unknown shape and conductivity scatters the incident wave in free space and the scattered near and far fields are measured. By using measured fields, the imaging problem is reformulated into an optimization problem and solved by the genetic algorithm. Numerical results show that the convergence speed and final reconstructed results by using near‐field data are better than those obtained by using far‐field data. This work provides both comparative and quantitative information. © 2001 John Wiley & Sons, Inc. Int J RF and Microwave CAE 11: 69–73, 2001.     

Investigation of point-to-point performance test of touch trigger probes on coordinate-measuring machines

A major factor contributing to the total measuring error of coordinate measuring machines (CMMs) is the performance of the probing sub-system. Probing test methods are typically used to detect errors due to the probing sub-system. The probe performance evaluation method specified in the ANSI B89 standard is investigated in this paper. The sampling plan associated in the probe performance evaluation was tested by using experimental probing data from a CMM. Research findings indicate that the performance of touch trigger probes is overestimated due to a systematic bias in the vertical direction of the best-fit reference ball center in the probe performance test. A two-latitude sampling plan synthesis method based on a pretravel model for touch trigger probes is proposed in this paper. The proposed method can be used to accurately identify the reference ball center in the performance test of touch trigger probes.     

Kinematic analysis of 3SPS+1PS bionic parallel test platform for hip joint simulator based on unit quaternion

As a novel parallel hip joint simulator, the 3SPS+1PS bionic parallel test platform with 4 degrees of freedom including three rotations and one translation is proposed. SPS denotes the spherical-prismatic-spherical leg and PS denotes the prismatic-spherical leg where only the prismatic joint is actuated and hence underlined. By means of the unit quaternion method, the formulae for solving the inverse/forward displacement, the inverse/forward velocity and the inverse/forward acceleration kinematics are derived. Using the unit quaternion to represent the position and orientation of a moving platform, singularities caused by Euler angles can be avoided. Combining the topological structure characteristics of the 3SPS+1PS bionic parallel test platform and letting the three-dimensional (3-D) motion of a human hip joint as its output movement, the displacement trajectories of three active legs are constructed based on the inverse displacement kinematics. The forward kinematic tests whose data are recorded by a 3-D orientation capture system are carried out on the developed parallel hip joint simulator. Moreover, the results of the forward kinematic tests prove that the 3SPS+1PS bionic parallel test platform can approximately represent human hip joint motion and provide more reliable experimental data for hip joint prostheses in clinical application.     

Physiological responses to simulated firefighter exercise protocols in varying environments

For decades, research to quantify the effects of firefighting activities and personal protective equipment on physiology and biomechanics has been conducted in a variety of testing environments. It is unknown if these different environments provide similar information and comparable responses. A novel Firefighting Activities Station, which simulates four common fireground tasks, is presented for use with an environmental chamber in a controlled laboratory setting. Nineteen firefighters completed three different exercise protocols following common research practices. Simulated firefighting activities conducted in an environmental chamber or live-fire structures elicited similar physiological responses (max heart rate: 190.1 vs 188.0 bpm, core temperature response: 0.047°C/min vs 0.043°C/min) and accelerometry counts. However, the response to a treadmill protocol commonly used in laboratory settings resulted in significantly lower heart rate (178.4 vs 188.0 bpm), core temperature response (0.037°C/min vs 0.043°C/min) and physical activity counts compared with firefighting activities in the burn building.

Practitioner Summary: We introduce a new approach for simulating realistic firefighting activities in a controlled laboratory environment for ergonomics assessment of fire service equipment and personnel. Physiological responses to this proposed protocol more closely replicate those from live-fire activities than a traditional treadmill protocol and are simple to replicate and standardise.     

Computing Green's function of the initial-boundary value problem for the wave equation in a layered cylinder

A new analytical method for the approximate computation of the time-dependent Green's function for the initial-boundary value problem of the three-dimensional wave equation on multi-layered bounded cylinder is suggested in this paper. The method is based on the derivation of eigenvalues and eigenfunctions for an ordinary differential equation with piecewise constant coefficients, and an approximate computation of Green's function in the form of the Fourier series with a finite number of terms relative to the orthogonal set of the derived eigenfunctions. The computational experiment confirms the robustness of the method.     

模拟抗原（Ac-NK16-Ahx-3）免疫反应抗体ELISA检测方法研究

为满足实验室单克隆抗体的制备研究,本实验特对实验室常用的制备单抗的模拟抗原（Ac-NK16-Ahx-3）进行ELISA间接法检测,进而建立一种高效的检测方法。通过对不同稀释度待测抗体的免疫吸附测定,检测出它的最终灵敏度为0.078mg/mL,最佳二抗稀释倍数为300倍,其最佳拟合曲线为y=-0.0732x＋0.6875,R2=0.8619。并且,通过统计学方法进行统计分析,确定出各实验组的相关性及变异系数,从而排除实验中的操作误差,最终可确定最佳的实验条件,并保证实验的准确性。     

Model test of helical angle effect on coal loading performance of shear drum

The work presented in this paper focuses on improving coal loading performance of shear drum.Employing the similarity theory,we carried out a dimensional analysis of the correlation parameters which in...