(Non-)Ergodicity of a Degenerate Diffusion Modeling the Fiber Lay Down Process

This paper presents the results of an experimental setup for a position tracking system that is to control a working table to track a workpiece on a moving conveyor belt, such that the manipulator placed on the working table is able to operate upon the workpiece while the workpiece is still moving. The feedback control employs a reflective type optical sensor which is placed on the table, to measure the relative positions of the working table and the workpiece. A predictive method to compensate for the effect of sensor output saturation on tracking performance is investigated in detail. The application of this tracking control to industrial production lines to achieve a nonstop work flow may shorten overall manufacturing time, and therefore improve the production efficiency and increase the productivity.

Dans cet article, nous introduisons un processus de Markov dont l’unique distribution invariante est le modèle d’Ising Curie–Weiss de criticalité auto-organisée que nous avons construit et étudié dans (Ann. Probab. 44(1):444-478, 2016). Dans le cas Gaussien, nous montrons rigoureusement qu’il s’agit d’un modèle dynamique de criticalité auto-organisée : les fluctuations de la somme $S_{n}(\cdot)$ du processus évoluent à une vitesse de temps d’ordre $\sqrt{n}$ et à une échelle spatiale d’ordre $n^{3/4}$ et le processus limite est la solution d’une équation différentielle stochastique « critique ».

We provide non-asymptotic $L^1$ bounds to the normal for four well-known models in statistical physics and particle systems in $\mathbb{Z}^d$; the ferromagnetic nearest-neighbor Ising model, the supercritical bond percolation model, the voter model and the contact process. In the Ising model, we obtain an $L^1$ distance bound between the total magnetization and the normal distribution at any temperature when the magnetic moment parameter is nonzero, and when the inverse temperature is below critical and the magnetic moment parameter is zero. In the percolation model we obtain such a bound for the total number of points in a finite region belonging to an infinite cluster in dimensions $d \ge 2$, in the voter model for the occupation time of the origin in dimensions $d \ge 7$, and for finite time integrals of non-constant increasing cylindrical functions evaluated on the one dimensional supercritical contact process started in its unique invariant distribution. The tool developed for these purposes is a version of Stein's method adapted to positively associated random variables. In one dimension, letting $\boldsymbol{\xi}=(\xi_1,\ldots,\xi_m)$ be a positively associated mean zero random vector with components that obey the bound $|\xi_i| \le B, i=1,\ldots,m$, and whose sum $W = \sum_{i=1}^m \xi_i$ has variance 1, it holds that $$ d_1 \left(\mathcal{L}(W),\mathcal{L}(Z) \right) \leq 5B + \sqrt{\frac{8}{\pi}}\sum_{i \neq j} \mathbb{E}[\xi_i \xi_j] $$ where $Z$ has the standard normal distribution and $d_1(\cdot,\cdot)$ is the $L^1$ metric. Our methods apply in the multidimensional case with the $L^1$ metric replaced by a smooth function metric.

Calcium-Dependent Synaptic Vesicle Trafficking Underlies Indefatigable Release at the Hair Cell Afferent Fiber Synapse

On-line application of near infrared (NIR) spectroscopy in food production

Real‐time inspection and removal of individual Fusarium head blight (FHB) infected corn grains from the processing lines has been a challenging issue due to the bulk handling and smaller kernel size. In this study, four different variants (small(s), medium(m), nano(n), and large(l)) of You Only Look Once (YOLO) version 5 object detection technique were trained for the detection of Fusarium infection in a moving monolayer of touching and non‐touching corn grains. The YOLOv5 object detection models were evaluated for their performance in detecting FHB infection in individual corn grains. A heterogeneous dataset containing images and video frames of healthy and FHB infected corn grains in different illuminations was utilized. The mean average precision calculated at Intersection over Union threshold of .5 (mAP@50) was 99%, 98%, 95%, and 96% for YOLOv5‐s, YOLOv5‐m, YOLOv5‐n, and YOLOv5‐l models, respectively. The detection speed in videos was 3.9, 1.6, 9.8, and .8 frames per second for YOLOv5‐s, m, n, and l models, respectively. For non‐touching grains, all four variants of the YOLOv5 model showed 100% precision, but for touching grains, all variants showed false negatives in detection of FHB infection, especially on overlapping kernels. The recall values were found to be 98%, 99%, 96%, and 97% for YOLOv5‐s, m, n, and l models, respectively. The best combination of mAP, detection speed, and lower false negatives was achieved by the YOLOv5‐m model. YOLOv5‐m has the potential for use in real‐time detection of Fusarium infection in corn grains apart from lag time in videos.Practical ApplicationThe developed video analysis technique based on YOLOv5 object detection method will be beneficial for the accurate identification of Fusarium infected corn grains in bulk handling facilities. The individual FHB infected grains could be detected on processing lines and could be used for real‐time inspection replacing the random sampling techniques currently used, thereby preventing the entry of Fusarium mycotoxins in the food chain. For non touching corn grains, all the YOLOv5 model variants showed a 100% precision in identifying the healthy and FHB infected grains. For touching grains, YOLOv5‐m model showed the best combination of mAP, detection speed, and lower false negatives proving appropriate for inspection on moving conveyor belts. The nano model with the lightweight architecture installed in portable devices can be used for immediate detection of FHB infection without lag time.

Commentary on Historical Intimate Partner Violence and Its Impact on Well-Being and Risk for Elder Abuse in Older Women

Turbulent impinging jets at three different jet nozzle forms were numerically analyzed using the SIMPLE algorithm and k-epsilon turbulent model to investigate the flow field and heat transfer characteristics. The food placed upon a moving conveyor belt cooled by series of impinging jets under a specific condition. Three semi-confined domains with different jet nozzles were established, thereby with slot, rectangular, and funnel-shaped nozzles, respectively. Based on computational fluid dynamic (CFD) calculations, distributions of the temperature and wind velocity at four critical cross-sections of domains were compared. The results reveal that the freezing rate of foods mainly relates to temperature and wind velocity. For three semi-confined domains, the impinging jet with slot nozzles produces higher exit wind velocity, lower center temperature, and a better mass flow uniformity than others, which could better improve the heat transfer performance, and could increase the freezing rate of foods.

A novel aerosol generation system has been constructed for use in a large wind tunnel for two distinct research projects. One project requires a uniform aerosol concentration over the wind tunnel cross section, while the other project demands a stratified aerosol concentration distribution. The system consists of an array of venturi nozzles, which entrains particulate matter from a moving conveyor belt and disperses it into the tunnel under the force provided by a compressed air source. For the stratified release configuration, only the bottom row of nozzles was used and a confinement sleeve was installed to prevent mixing with clean air; the mixing fans were omitted from this configuration. The uniform release arrangement was tested by gravimetrically measuring particle concentration over the cross section of the tunnel for tunnel speeds of 0.1 and 1.0 m/s; uniformity was achieved within a coefficient of variation of 6.4%. The stratified distribution results show a high concentration near the floor, whic...

Robotics research continuously seeks to improve productivity in manufacturing automation. In the last several years, more and more efforts have been put in the integration of multiple sensors into robot systems. The goal is to make robots more adaptive and flexible in unstructured or frequently changing environments, and to enable robots to execute intelligent tasks. Thus the robot productivity as well as applicability can be improved. The object of this study is to develop a multisensor controlled robotic tracking and automatic pick and place system. The system is designed for recognizing and tracking an object which is selected from multiple objects that are unknown and randomly placed on a moving conveyor belt, using a vision, infrared and encoder sensors in the feedback loop. The robot tracks the parts and transfers them to the proper pallets.

We experimentally demonstrate that the flow rate of granular material through an aperture is controlled by the exit velocity imposed on the particles and not by the pressure at the base, contrary to what is often assumed in previous work. This result is achieved by studying the discharge process of a dense packing of monosized disks through an orifice. The flow is driven by a conveyor belt. This two-dimensional horizontal setup allows us to independently control the velocity at which the disks escape the horizontal silo and the pressure in the vicinity of the aperture. The flow rate is found to be proportional to the belt velocity, independent of the amount of disks in the container and, thus, independent of the pressure in the outlet region. In addition, this specific configuration makes it possible to get information on the system dynamics from a single image of the disks that rest on the conveyor belt after the discharge.

Optimal control problems for degenerate two-dimensional diffusion processes are considered. The processes could serve as models for wear processes. The objective is to make the controlled process leave the continuation region through a given part of the boundary. Explicit and exact solutions are obtained for important processes such as the geometric Brownian motion and the Ornstein-Uhlenbeck process.

Terahertz (THz) imaging technology has a great potential application owing to the unique properties of THz wave that has both permeability and feature of straight [1]. Especially for real-time THz imaging detectors, field-effect transistor (FET)-based plasmonic THz detectors [2] are now being intensively developed in multi-pixel array configuration by exploiting the silicon (Si) CMOS technology advantages of low-cost and high integration density. In terms of the circuit design approach, by utilizing resistive self-mixing in the FET channel, a 0.65 THz focal plane array (FPA) detector was reported [3] and more recently, a 1 k-pixel camera has been demonstrated for a real-time THz imaging by 65-nm CMOS technology [4]. In this work, we experimentally demonstrate the real-time terahertz (THz) imaging of moving object on the conveyer belt by implementing asymmetric FET-based plasmonic 2×200 array scanner in 65-nm CMOS technology. Based on the enhanced detecting performance from our previous works [5][6], fast and uniform detection results are presented by novel device and circuit design for real-time THz imaging.

Since 2015, ‘workerless factories’ have surfaced in various industrial zones in China, capturing media attention. In one case, on the shop floor of a mobile phone module manufacturer, conveyor belts were staffed not by dispirited and sweating workers, but by robots executing repetitive pre-programmed tasks. China became the largest market for industrial robots in 2013. This wave of robotisation is largely triggered by the rising labour costs and growing labour activism. By 2019, 140,500 new robots were sold nationwide—a twofold increase from five years earlier. While media touted how industrial automation pushed Chinese economy to shift from leveraging its ‘labour divided’ to developing a ‘robot dividend’, labour scholars and activists began to wonder how workers could gain a fair share of the ‘robot dividend.’ Recent research has confirmed that in some firms that adopted robots, wage increases lagged far behind the growth of productivity, while in others, wages remained stagnant or were even slashed. It is obvious that the growing wave of labour insurgencies that spread China in the early 2010s was not extended to struggles over labour’s benefits in technological upgrading. Why? Industrial Automation’s Impact on Employment and Skills Even in firms less extreme than the ‘workerless factories’, the power of industrial automation to slash labour is very dramatic. My own research in four factories in a city in South China identifies a dramatic reduction in labour demand, ranging between 67 and 85 percent cut per production line. A recent study of 299 manufacturing firms that adopted technological upgrading in Guangdong Province showed each firm fired an average of ninety-six employees, accounting for 9.58 percent of the total workforce. On the shop floor, about 80 percent of positions could easily be replaced with machines1. However, so far, we have not witnessed a large number of the workers made redundant by technological upgrading being thrown on to the streets. There are several reasons. First, firms upgraded their equipment gradually rather than resorting to wholesale shifts to new automated lines. Such incremental arrangements gave companies time to adjust workers’ positions and limit new recruitment. Second, taking advantage of migrant workers’ high turnover rate and specific wage structure, most employers did not have to actively dismiss workers, but used other tactics—e.g. slashing overtime work hours--- to force workers to quit on their own initiative. Third, a few firms were able to absorb the surplus labour by expanding their production lines; however, that is contingent on the firm’s position in the value chain as well as its broader market status. The impact of automation on workers’ skills is equally controversial. Although technological upgrading has the potential of upgrading workers’ skills, the outcome is highly contingent. My research has discovered that skilled workers are often the main target for job replacement due to their high wages and enhanced bargaining power. Another research has revealed that women workers are offered much less in-house training than their male counterparts because most employers uphold an ideology of gender stereotyping that considers women to be ‘fearful of machines’ or deficient in logical thinking2. Considering that China’s past development path has hinged on labour-intensive production positioned in the low-end of global commodity chain, many manufacturers are either slow or reluctant to take up labour retraining. Among the eight manufacturers I studied, only one invested in training workers, and this was because the company engages in high-precision metalwork that requires substantial levels of skill in the production process. Mr Zhou, the owner of a firm that produces highend parts for optical-fibre communication equipment, chose to automate to achieve quality improvement, not just larger output. Building on his previous experience working in a state-owned enterprise, he set up an in-house apprenticeship program to train skilled workers. He stated: ‘Machinery is something everybody can buy, but a good production process needs to be designed. One component is hardware and the other is software.’ As a small and medium-sized enterprise, the case of Mr Zhou’s company is quite exceptional. Given the high turnover rate, very few employers in Dongguan are willing to invest in workers’ training. Workers’ Reactions to Technological Upgrading How have...

In this chapter we express the classical Wigner function by a degenerate diffusion process [164] solving a randomly perturbed Newton equation. We discuss first some estimates on the solution of these equations and the long time behaviour of the diffusion process. We discuss a relation between the classical Wigner function and the quantum one. We approximate the large time behaviour of the density matrix by the classical Wigner function. In this way we obtain some estimates on the decoherence in space expressed by the correlation functions of the diffusion process.