聚氨酯弹性体跟面不同性能之间关系的研究

制备了一系列不同硬度的聚醚型聚氨酯跟面,采用最新防滑试验方法,测试其在两种标准瓷砖界面上的摩擦系数,同时测定了硬度和耐磨性,并研究了这3项性能之间的相互关系。

皮鞋跟面耐磨性能测试方法的研究

针对我国现行皮鞋鞋跟耐磨性能检测标准GB/T3903.2-2008《鞋类通用检验方法耐磨试验方法》、GB/T9867-2008《硫化橡胶或热塑性橡胶耐磨性能的测定(旋转辊筒式磨耗机法)》、GB/T1689-1998《硫化橡胶耐磨性能的测定(用阿克隆磨耗机)》等存在的一些问题,选用了目前男、女皮鞋跟面中最具有代表性和可比性的3种材料,分别为橡胶、塑料和聚氨酯,以及与试穿实验结果进行比对,得出GB/T9867-2008《硫化橡胶或热塑性橡胶耐磨性能的测定(旋转辊筒式磨耗机法)》方法适合对多种皮鞋跟面材料进行测试的结论。

新近发布的6项鞋类国家标准解读

为使标准使用者更好地理解标准,促进标准更好地实施,对2021年发布的《鞋类勾心》《鞋类内底试验方法 跟部持钉力》《鞋类外底试验方法 撕裂强度》《鞋类外底试验方法 针撕破强度》《鞋类整鞋试验方法 鞋跟结合强度》和《皮鞋跟面耐磨性能试验方法》6项鞋类国家标准,从标准的编制背景、标准主要内容、修订内容三方面进行解读。6项标准分别于2022年3月1日、2022年5月1日起实施,标准的实施将进一步促进鞋类部件质量的提高,并提高鞋类产品的安全性。

An unscented particle filter for ground maneuvering target tracking

In this study, an unscented particle filtering method based on an interacting multiple model (IMM) frame for a Markovian switching system is presented. The method integrates the multiple model (MM) filter with an unscented particle filter (UPF) by an interaction step at the beginning. The framework (interaction/mixing, filtering, and combination) is similar to that in a standard IMM filter, but an UPF is adopted in each model. Therefore, the filtering performance and degeneracy phenomenon of particles are improved. The filtering method addresses nonlinear and/or non-Gaussian tracking problems. Simulation results show that the method has better tracking performance compared with the standard IMM-type filter and IMM particle filter.

Robust Adaptive Path Following for Underactuated Surface Vessels with Uncertain Dynamics

A robust adaptive control strategy was developed to force an underactuated surface vessel to follow a reference path,despite the presence of uncertain parameters and unstructured uncertainties including exogenous disturbances and measurement noise.The reference path can be a curve or a straight line.The proposed controller was designed by using Lyapunov’s direct method and sliding mode control and backstepping techniques.Because the sway axis of the vessel was not directly actuated,two sliding surfaces were introduced,the first one in terms of the surge motion tracking errors and the second one for the yaw motion tracking errors.The adaptive control law guaranteed the uniform ultimate boundedness of the tracking errors.Numerical simulation results were provided to validate the effectiveness of the proposed controller for path following of underactuated surface vessels.

Tracking facial features with occlusions

Facial expression recognition consists of determining what kind of emotional content is presented in a human face. The problem presents a complex area for exploration, since it encompasses face acquisition, facial feature tracking, facial ex- pression classification. Facial feature tracking is of the most interest. Active Appearance Model (AAM) enables accurate tracking of facial features in real-time, but lacks occlusions and self-occlusions. In this paper we propose a solution to improve the accuracy of fitting technique. The idea is to include occluded images into AAM training data. We demonstrate the results by running ex- periments using gradient descent algorithm for fitting the AAM. Our experiments show that using fitting algorithm with occluded training data improves the fitting quality of the algorithm.

Trajectory planning and tracking control for underactuated unmanned surface vessels

The trajectory planning and tracking control for an underactuated unmanned surface vessel(USV) were addressed.The reference trajectory was generated by a virtual USV,and the error equation of trajectory tracking for underactuated USV was obtained,which transformed the tracking and stabilization problem of underactuated USV into the stabilization problem of the trajectory tracking error equation.A nonlinear state feedback controller was proposed based on backstepping technique and Lyapunov's direct method.By means of Lyapunov analysis,it is proved that the proposed controller ensures that the solutions of closed loop system have the ultimate boundedness property.Numerical simulation results are presented to validate the effectiveness and robustness of the proposed controller.

Adaptation of feed rate for 3-axis CNC high-speed machining

To improve the efficiency of CNC machining, assumptive transit circular arc is used to contour two adjacent moves together on the comer to make smooth paths. The radios of transit circular arc can be adjusted with contour accuracy, and the feed rate on the corner can be controlled through limiting the maximum feed rate of transit circular arc segment. A look-ahead algorithm for a series of moves is proposed for speed adjustment in advance, which avoids the occurrence of overload of cutting tool on the comer and reduces the servo track error of parts on the corner or of circular arc move. Equivalent trapezoidal velocity profile is used to analyze the speed of S-curve velocity profile and work out its accurate interpolation, which overcomes the disadvantage of looking up table to calculate feed rate approximately, hence high accuracy and fine surface quality can be obtained while the machining speed is high. The proposed methods can meet the requirements of real-time analysis of high-speed machining. The presented algorithm is effective and has been adopted by CNC system of newly developed high-speed milling machine.

Area Variation Based Color Snake Algorithm for Moving Object Tracking

A snake algorithm has been known that it has a strong point in extracting the exact contour of an object. But it is apt to be influenced by scattered edges around the control points. Since the shape of a moving object in 2D image changes a lot due to its rotation and translation in the 3D space, the conventional algorithm that takes into account slowly moving objects cannot provide an appropriate solution. To utilize the advantages of the snake algorithm while minimizing the drawbacks, this paper proposes the area variation based color snake algorithm for moving object tracking. The proposed algorithm includes a new energy term which is used for preserving the shape of an object between two consecutive images. The proposed one can also segment precisely interesting objects on complex image since it is based on color information. Experiment results show that the proposed algorithm is very effective in various environments.

Adaptive Resource Allocation Algorithm for Internet of Things with Bandwidth Constraint

In order to improve the transmission accuracy and efficiency of sensing and actuating signals in Internet of Things （loT） and ensure the system stability, an adaptive resource allocation algorithm is proposed, which dynami- cally assigns the network bandwidth and priority among components according to their signals＇ frequency domain characteristics. A remote sensed and controlled unmanned ground vehicle （UGV） path tracking test-bed was devel- oped and multiple UGV＇s tracking error signals were measured in the simulation for performance evaluation. Results show that with the same network bandwidth constraints, the proposed algorithm can reduce,, the accumulated and maximum errors of UGV path tracking by over 60% compared with the conventional static algorithm.

Ribbon model based path tracking method for autonomous ground vehicles

To resolve the path tracking problem of autonomous ground vehicles,an analysis of existing path tracking methods was carried out and an important conclusion was got.The vehicle-road model is crucial for path following.Based on the conclusion,a new vehicle-road model named "ribbon model" was constructed with consideration of road width and vehicle geometry structure.A new vehicle-road evaluation algorithm was proposed based on this model,and a new path tracking controller including a steering controller and a speed controller was designed.The difficulties of preview distance selection and parameters tuning with speed in the pure following controller are avoided in this controller.To verify the performance of the novel method,simulation and real vehicle experiments were carried out.Experimental results show that the path tracking controller can keep the vehicle in the road running as fast as possible,so it can adjust the control strategy,such as safety,amenity,and rapidity criteria autonomously according to the road situation.This is important for the controller to adapt to different kinds of environments,and can improve the performance of autonomous ground vehicles significantly.

Nitrogen budget in the Changjiang River drainage area

We established a budget model of nitrogen （N） inputs and outputs between watersheds and waterbodies to determine the sources of riverine N in the Changjiang （Yangtze） River drainage area. Nitrogen inputs in the budget included N from synthetic fertilizer, biological fixation by leguminous and other crops, wet/dry atmospheric deposition, excreta from humans and animals, and crop residues. The total N input was estimated to be 17.6 Tg, of which 20% or 3.5 Tg N was transported into waterbodies. Of the total N transported into waterbodies, the largest proportion was N from animal waste （26%）, followed by N from atmospheric wet/dry deposition （25%）, synthetic fertilizer N （17%）, N in sewage wastes （17%）, N in human waste from rural areas （6%） and industrial wastewater N （9%）. We studied the spatial patterns of N inputs and outputs by dividing the Changjiang River drainage area into four sub-basins, from upstream to downstream： the Tongtian River drainage area （TTD, the headwater drainage area, 138 000 l^n2, less disturbed by human activities）; the Jinsha River drainage area （JSD, 347 000 km2, less disturbed by human activities, approx. 3 500 km upstream of the Changjiang estuary）; the Pingshan-Yichang drainage area （PYD, 520 500 krn2, large-scale human disturbance, about 2 000 km upstream of the Changjiang estuary）; and the Yichang-Datong drainage area （YDD, 699 900 km^2, large-scale httman disturbance, approx. 620 km upstream of the Changjiang estuary）. The average N input into waterbodies was 2.3, 7.3, 24.1, and 28.2 kg N/ha in the TTD, JSD, PYD, and YDD sub-basins, respectively, suggesting an increase of N-components of more than 10 times from upstream to downstream areas.

Tracking of Flat Belts

When applying fiat belts, correct tracking of the belt through the installation has to be assured. Since flat belts are commonly used for conveying and transmission purposes, tracking systems have been well developed, but the ultimate tracking behaviour of the belt can be greatly enhanced by taking special care in the creation of an adequate tracking mechanism. To obtain long-life operation and full value from the equipment, the correct tracking technique plays an important role. This paper deals with two tracking techniques： The skewed and the angled pulley axis. Numerical simulation results are compared with both measurements and an analytical approach. The advantages of numerical simulation compared to experimental tests are ease, convenience and the absence of any safety risk. Compared to analytical approaches the simulation is used for systems for which simple closed form analytic solutions are not possible.

NUMERICAL EXPERIMENTS ON THE IMPACTS OF SEA SPRAY ON TROPICAL CYCLONES

The latest version of sea spray flux parameterization scheme developed by Andreas is coupled with the PSU/NCAR model MM5 in this paper. A western Pacific tropical cyclone named Nabi in 2005 is simulated using this coupled air-sea spray modeling system to study the impacts of sea spray evaporation on the evolution of tropical cyclones. The results demonstrate that sea spray can lead to a significant increase of heat fluxes in the air-sea interface, especially the latent heat flux, the maximum of which can increase by up to about 35% - 80% The latent heat flux seems to be more important than the sensible heat flux for the evolution of tropical cyclones. Regardless of whether sea spray fluxes have been considered, the model can always simulate the track of Nabi well, which seems to indicate that sea spray has little impact on the movement of tropical cyclones. However, with sea spray fluxes taken into account in the model, the intensity of a simulated tropical cyclone can have significant increase. Due to the enhancement of water vapor and heat from the sea surface to the air caused by sea spray, the warm core structure is better-defined, the minimum sea level pressure decreases and the vertical speed is stronger around the eye in the experiments, which is propitious to the development and evolution of tropical cyclones.

Trajectory tracking control for underactuated unmanned surface vehicles with dynamic uncertainties

The trajectory tracking control problem for underactuated unmanned surface vehicles(USV) was addressed, and the control system took account of the uncertain influences induced by model perturbation, external disturbance, etc. By introducing the reference, trajectory was generated by a virtual USV, and the error equation of trajectory tracking for USV was obtained, which transformed the tracking problem of underactuated USV into the stabilization problem of the trajectory tracking error equation. A backstepping adaptive sliding mode controller was proposed based on backstepping technology and method of dynamic slide model control. By means of theoretical analysis, it is proved that the proposed controller ensures that the solutions of closed loop system have the ultimate boundedness property. Simulation results are presented to illustrate the effectiveness of the proposed controller.

An advanced segmentation using area and boundary tracing technique in extraction of lungs region

A new method is presented for the segmentation of pulmonary parenchyma. The proposed method is based on the area calculation of different objects in the image. The main purpose of the proposed algorithm is the segment of the lungs images from the computer tomography(CT) images. The original image is binarized using the bit-plane slicing technique and among the different images the best binarized image is chosen. After binarization, the labeling is done and the area of each label is calculated from which the next level of binarized image is obtained. Then, the boundary tracing algorithm is applied to get another level of binarized image. The proposed method is able to extract lung region from the original images. The experimental results show the significance of the proposed method.

Erratum to: An advanced segmentation using area and boundary tracing technique in extraction of lungs region

Erratum to：J.Cent.South Univ.（2014）21：3811-3820DOI：10.1007/s11771-014-2366-9The original version of this article unfortunately contained three mistakes.The mistakes are corrected as follows：1）The spelling of third author is incorrect.The correct name is Jae-Young PYUN.2）The information of corresponding author is incorrect.The correct information should be Goo-Rak KWON,Professor,PhD;Tel/Fax：＋98-711-7264102;E-mail：grkwon@chosun.ac.kr

Serret-Frenet frame based on path following control for underactuated unmanned surface vehicles with dynamic uncertainties

The path following problem for an underactuated unmanned surface vehicle(USV) in the Serret-Frenet frame is addressed. The control system takes account of the uncertain influence induced by model perturbation, external disturbance, etc. By introducing the Serret-Frenet frame and global coordinate transformation, the control problem of underactuated system(a nonlinear system with single-input and ternate-output) is transformed into the control problem of actuated system(a single-input and single-output nonlinear system), which simplifies the controller design. A backstepping adaptive sliding mode controller(BADSMC)is proposed based on backstepping design technique, adaptive method and theory of dynamic slide model control(DSMC). Then, it is proven that the state of closed loop system is globally stabilized to the desired configuration with the proposed controller. Simulation results are presented to illustrate the effectiveness of the proposed controller.

Modulating a Solar Parabolic Dish to Produce Boiled Water

A two-meter parabolic solar concentration dish has been modulated to produce boiled water over 100℃ for various purposes of central heating services. For an effective performance, the system required both continuous exposure of the dish to sunlight during the day time as well as to an electric control circuit （tracking system）. The amount of the potable water was dependent particularly on the accurate centering of the system which could increase upon preheating. This system has therefore been possible to heat up water at home via increasing the temperature in hot tank by both covering the hot water tank and isolating it from the surroundings using insulators. Applications of a successful parabolic solar concentration has also been designed to provide desalinated water for domestic usage which operates with temperatures higher than other types of the solar radiation for the future.

Application of a Zero-speed Fin Stabilizer for Roll Reduction of a Marine Robot near the Surface

A zero-speed fin stabilizer system was developed for rolling control of a marine robot.As a robot steering device near the sea surface with low speed,it will have rolling motion due to disturbance from waves.Based on the working principle of a zero-speed fin stabilizer and a marine robot’s dynamic properties,a roll damping controller was designed with a master-slave structure.It was composed of a sliding mode controller and an output tracking controller that calculates the desired righting moment and drives the zero-speed fin stabilizer.The methods of input-output linearization and model reference were used to realize the tracking control.Simulations were presented to demonstrate the validity of the control law proposed.