ON BENEFICIAL CONNECTIONS AMONG SHORT AGRI-FOOD SUPPLY CHAINS AND CIRCULAR BIOECONOMY

The concepts of short agri-food supply chains and circular bioeconemy are complementary and mutually reinforcing, while they may play an important role in sustainability transitions. The elimination of middlemen and the possibilities of forward vertical integration of farmers are the key components ofshort agri-food supply chains, while bioeconomy refers to the sustainable production and use of biological resources stemming from forestry, agriculture, fisheries, and waste streams. The development of closed-loop systems where waste is converted into new resources, lies in the core of circular bioeconomy, which seeks to reduce waste and maximize resource usage. A sustainable and regenerative economy where waste is viewed as a resource and the use of finite resources is decreased is what this strategy seeks to achieve. When combined, short agri-food supply chains and circular bioeconomy can support sustainable economic growth, social advancement, and environmental protection by encouraging local manufacturing, minimizing waste, and developing innovative bio-based goods and procedures. In this article, we examine the benefits which occur in short agri-food supply when they adopt the principles of circular bioeconomy. Also, we examine how can the ideas of the circular bioeconomy be applied to short agri-food supply chains in order to minimize waste and maximize resource usage. In addition, we explore the corresponding difficulties and opportunities for creating bio-based goods and procedures in short agri-food supply chains. Last but not least, we discuss the effects of short agri-food supply chains and the circular bioeconomy on global agri-food systems and how these concepts are connected with issues at stake, such as food security and sustainability.

Design and Implementation of Regulated Oxygenation Based Ventilation System with Feedback Mechanism

A multifunctional medical device for the aid of COVID affected patients are scarce. This paper proposes an automated medical device which is incorporated with a feedback mechanism and a GSM base emergency alarm system. The combined sensors in the prototype can acquire readings of a patient's temperature, heart rate, oxygen saturation (SpO2), respiratory rate (RR), and heart condition noninvasively and can send these vitals easily via SMS in real time. Based on the patient's SpO2 level and RR, the system can control the oxygen flow through a nasal canola with the aid of a servo motor mechanism. The system derives information from the sensors to operate automatically based on the degrading vitals of a patient. Due to its nature of user friendliness the protype can be operated without much prior medical knowledge. © 2023 IEEE.

Estimations and Control of Julia Sets of the SIS Model Perturbed by Noise.

The estimations and control of Julia sets of the SIS(susceptible-infectious-susceptible) model under noise perturbation are studied. At first, a discrete SIS model is introduced, and the effects of additive and multiplicative noises on the fractal characteristics of the SIS model are discussed. Then, estimations of the Julia sets of the SIS model under additive and multiplicative noise perturbations are given, respectively. At last, the feedback control method is used to set appropriate controllers to realize control of the Julia set, and the influence of noise on the Julia set of the SIS model is reduced. The reason why this method is effective is also explained.

Effectiveness of feedback control and the trade-off between death by COVID-19 and costs of countermeasures.

We provided a framework of a mathematical epidemic modeling and a countermeasure against the novel coronavirus disease (COVID-19) under no vaccines and specific medicines. The fact that even asymptomatic cases are infectious plays an important role for disease transmission and control. Some patients recover without developing the disease; therefore, the actual number of infected persons is expected to be greater than the number of confirmed cases of infection. Our study distinguished between cases of confirmed infection and infected persons in public places to investigate the effect of isolation. An epidemic model was established by utilizing a modified extended Susceptible-Exposed-Infectious-Recovered model incorporating three types of infectious and isolated compartments, abbreviated as SEIIIHHHR. Assuming that the intensity of behavioral restrictions can be controlled and be divided into multiple levels, we proposed the feedback controller approach to implement behavioral restrictions based on the active number of hospitalized persons. Numerical simulations were conducted using different detection rates and symptomatic ratios of infected persons. We investigated the appropriate timing for changing the degree of behavioral restrictions and confirmed that early initiating behavioral restrictions is a reasonable measure to reduce the burden on the health care system. We also examined the trade-off between reducing the cumulative number of deaths by the COVID-19 and saving the cost to prevent the spread of the virus. We concluded that a bang-bang control of the behavioral restriction can reduce the socio-economic cost, while a control of the restrictions with multiple levels can reduce the cumulative number of deaths by infection.

Dynamical analysis of a discrete-time COVID-19 epidemic model.

In this paper, we explore local dynamics with topological classifications, bifurcation analysis, and chaos control in a discrete-time COVID-19 epidemic model in the interior of ℝ + 4 . It is explored that for all involved parametric values, discrete-time COVID-19 epidemic model has boundary equilibrium solution and also it has an interior equilibrium solution under definite parametric condition. We have explored the local dynamics with topological classifications about boundary and interior equilibrium solutions of the discrete-time COVID-19 epidemic model by linear stability theory. Further, for the discrete-time COVID-19 epidemic model, existence of periodic points and convergence rate are also investigated. It is also studied the existence of possible bifurcations about boundary and interior equilibrium solutions and proved that there exists no flip bifurcation about boundary equilibrium solution. Moreover, it is proved that about interior equilibrium solution, there exist Hopf and flip bifurcations, and we have studied these bifurcations by utilizing explicit criterion. Moreover, by feedback control strategy, chaos in the discrete COVID-19 epidemic model is also explored. Finally, theoretical results are verified numerically.

Navigating feedback practices across learning contexts: implications for feedback literacy

Student feedback practices have been primarily discussed within a context of the particular course or unit of study. Little attention has been paid to how students navigate their feedback practices as they progress through different learning contexts and whether they apply known feedback strategies in new settings. To open exploration of this issue, case studies of five participants were studied over different courses – undergraduate, direct-entry access program and postgraduate - in order to identify how learners' understandings of past and immediate contexts impacted their approaches to feedback. Data were collected through student artefacts which included e-portfolios completed in the direct-entry program and two interviews, approximately one year apart. Thematic analysis of the data indicated influences of learners' feedback histories on the application of feedback in new contexts. The findings highlight the need to consider students' past feedback experiences, as well as identify connections between courses, in order to assist students in applying feedback practices across contexts. Further research exploring how micro transitions between courses and students' lived experiences of interacting with feedback tools and materials influence their feedback literacy is recommended. [ FROM AUTHOR]

A pivotal restructuring of modelling the control of COVID-19 during and after massive vaccination for the next few years

T his paper presents a new mathematical feedback model to demonstrate how direct observations of the epidemiological compartments of population could be mapped to inputs, such that the social spread of the disease is asymptotically subdued. Details of the stabilization and robustness are included. This is a pivotal restructuring of modelling the control of corona virus from the current models in use world-wide which do not utilize feedback of functions of epidemiological compartments of population to construct the inputs. Although several vaccines have received Emergency Use Authorization (EUA) massive vaccination would take several years to reach herd immunity in most countries. Furthermore, the period of efficacy of the vaccination may be approximately one year only resulting in an unending vaccination. Even during the vaccination, there would be an urgent need to control the spread of the virus. When herd immunity is reached without feedback control and vaccination is discontinued, there could be new surges of the disease. These surges of disease could be prevented in appropriately designed stable feedback models. Moreover, extensive testing, contact tracing, and medical treatment of those found infected, must be maintained. © 2021, Philippine-American Academy of Science and Engineering. All rights reserved.

The Effect of Different Feedback Strategy on Learning Outcome inMicro-video Course Learning

The outbreak of COVID-19 promotes the development of online learning. Micro-video course has become the mainstream learning resource of online learning because of its concise theme, strong pertinence and vivid content. However, there are few researches on feedback strategy of micro-video course in basic education. Based on the principles of multi-media design and ADDIE instructional design model, a micro-video course of robot knowledge was designed in this study. Different feedback strategies(i.e., descriptive feedback (DF), evaluative feedback (EF), suggestive feedback(SF), guiding feedback (GF)) were embedded in the micro-video course. The effects of four feedback strategies on students' learning outcome, cognitive load, and learning motivation were explored through experiment. The results provide some suggestions for the production of basic education micro-video course. © 2022 IEEE.

Respect the Unstable: Delays and Saturation in Contact Tracing for Disease Control

Motivated by the novel coronavirus disease (COVID-19) pandemic, this paper aims to apply Gunter Stein's cautionary message of respecting the unstable to the problem of controlling the spread of an infectious disease. With this goal, we study the effect that delays and capacity constraints have in the test, trace, and isolate (TeTrIs) process, and how they impact its ability to prevent exponential disease spread. Our analysis highlights the critical importance of speed and scale in the TeTrIs process. Precisely, ensuring that the delay in the TeTrIs process is much smaller than the doubling time of the disease spread is necessary for achieving acceptable performance. Similarly, limited TeTrIs capacity introduces a threshold on the size of an outbreak beyond which the disease spreads almost like the uncontrolled case. Along the way, we provide numerical illustrations to highlight these points.

Compostable Packaging Waste Management—Main Barriers, Reasons, and the Potential Directions for Development

The paper aims to identify the main reasons for the low level of compostable packaging waste management and to propose potential directions for development. Based on qualitative research (individual in-depth interviews and focus group discussions using the Social Innovation Lab), these are: (1) the lack of uniform and transparent regulations regarding the planning and organization of a closed-loop system for compostable packaging, (2) insufficient communication between the private and public sectors on how to increase the use of compostable packaging, (3) poorly developed infrastructure for compostable waste recycling, and (4) a lack of financial incentives to support activities for the circular economy of composting packaging at the communal level. Moreover, the portfolio of bottom-up (initiated by consumers, educational institutions, and NGOs) and bottom-down dimension (national, regional programs) proposals are presented. The diagnosis of different view perspectives of the supply chain underlines the crucial role of stakeholder cooperation improvement.

Feedback and Control Course Labs for Distance Learning

Classic Feedback and Control is an undergraduate course that introduces students to concepts and methods for modeling, analysis, and design of single-input-single-output feedback control systems in the Electrical and/or Computer Engineering majors. In addition to using lectures to explain theories and assigning homework assignments for students to practice their modeling and analyses skills, instructors would usually supplement the course by a series of hardware-based experiments and software-based simulation labs so that students can apply the acquired knowledge to physical systems and real-world control problems. Similar to many other institutions, our ECE program offers a Feedback and Control course to junior students in the Electrical Engineering and Electromechanical Engineering majors. This course is a 3-hour lecture, 2-hour lab, as a 4-credit course. Topics discussed include modeling in both the time and the frequency domains, time response, model reduction, stability, steady-state error, root locus, design via root locus, frequency response, and design via frequency response. Due to the COVID-19 pandemic, both students and faculty in our institution were forced to work and study from home in summer 2020. In order to engage students in distance learning, application-oriented and active-learning opportunities were created. A series of exclusively software-based labs and projects were designed to help students gain a better understanding of how the knowledge are useful in real-world situations. Particularly, nine simulation labs and two simulation projects were used in the class of summer 2020. In order to evaluate the effectiveness of the designed simulation labs and projects in helping students to grasp and then apply the control concepts and ideas, surveys were conducted in the summer 2020 class to collect students' opinions and feedbacks. Among the 27 participating students, 81.4% of students “agree” or “strongly agree” that simulation laboratory exercises increased their interest in the subject, 85.1% of students “agree” or “strongly agree” that simulation laboratory exercises helped them better to learn course content, and 77.7% of the students thought simulation laboratory exercises were excellent or very good. We also compared the percentage of students who performed at the A, A-, B+, B, and B- levels with past records (while teaching was in-person), which turned out to be comparable and similar. This indicates the effectiveness of these simulation-based labs & projects, and their contribution in helping to maintain the course standard. © American Society for Engineering Education, 2021

Design and Evaluation of Undergraduate Feedback-control System Course in Distance Learning

This paper is a work-in-progress (WIP) paper. COVID19 pandemic profoundly changed the way educators teach and the way students learn. Our institution, the New York City College of Technology, abruptly switched to distance learning mode in Spring 2020 and continues to offer all courses online in Fall 2020. This paper presents the redesign and evaluation of an undergraduate Feedback Control System course to adapt to distance learning. Feedback Control System course is the last required course for the Bachelor of Technology (BTech) program in Computer Engineering Technology (CET), which has a 3-hour lecture lesson and a 3-hour lab session every week. Due to our BTech students' diverse mathematical backgrounds, students think this course is demanding even in the traditional face-to-face teaching mode. Teaching such a mathematically involved class in the distance learning mode poses significant challenges to both the instructors and the students. This paper documents our re-structure and redesign process of both the lecture and lab components to facilitate students' remote learning experience, satisfy the ABET accreditation criteria and maintain our pre-set learning standard. The online characteristic gives the instructors the freedom and a framework to teach classes in various delivery modes via synchronous lectures (like virtual meetings) and asynchronous online supplementary resources (for example, Blackboard). The arrangements we made to adjust to the distance learning mode include: a) decomposition of the course context into three modules and clear specification of the corresponding learning objectives of each module;b) combination of different technologies to create friendly and inclusive learning environment;c) frequent assessment of students' performance via online quizzes/tests;and d) carefully-designed laboratory assignments via MATLAB simulations that are able to demonstrate the entire feedback control process. A comparison of students' performance under the traditional face-to-face learning mode and the new distance learning mode is conducted. Based on assessment results, we will evaluate the effectiveness of our current teaching methodology/plan developed for distance learning and possibly identify potential areas for further improvement. © American Society for Engineering Education, 2021

Low-Cost Portable Emergency Mechanical Ventilator Proposed for Covid-19 Patients

The COVID-19 pandemic has resulted in severe shortages of ventilators around the world. COVID-19 patients with extreme acute respiratory distress syndrome (ARDS) have an unmet requirement for quickly transportable, emergency-use ventilators with adequate functionality. We present the design and validation of a simple, compact, and low-cost ventilator with features such as automatic dual mode switching and Advanced closed loop feedback control for the intelligent adult respiratory circuit. It involves the design and making of a prototype that will provide oxygen-regulated, volume and pressure controlled air for mechanical ventilation with sensors providing feedback signals for a closed loop control. © 2021 IEEE.

DESIGN OF AN AUTOMATED MONITORING AND CONTROL SYSTEM FOR THE SOFT DRINK CAPPING MACHINE AND PROCESS MIXER

Hierdie artikel is gebaseer op botteleringproses optimering deur deurlopende verbetering. n Gevallestudie is by maatskappy XYZ geloods. Die Ses Sigma Definieer, Meet, Ontleed, Verbeter, en Beheer metodologie het getoon dat die bottelering en doppie-opsit prosesse defekte by die drie sigma vlak lewer. Die 5 Hoekoms, Pareto-kaart, visgraatdiagram en Verskaffers, Insette, Prosesse, Uitsette, Kliente model het getoon dat los doppies (31.6%), lae opvulvlakke (29.2%) en leě bottels (28.9%) die vernaamste redes tot hoě kostes as gevolg van swak gehalte is. Die moniteringstelsel is ontwerp op die toegepaste wringkrag te meet, die doppie werkstuk status te monitor en die drankie temperatuur soos dit die hitteruiler verlaat te meet. Die verkoelingstelsel van die menger is ontwerp met n geslote lus beheerstelsel. As die drankie se temperatuur nie binne een of twee grade Celsius is nie, word dit gestuur vir sekondere verkoeling, anders beweeg dit aan. Die glikol inlaatklep word aangedryf sodat die vloei van die verkoelingsmiddel aangepas word om te verseker die primere verkoeling is doeltreffend. Die resultate toon dat dit moontlik is om die proses binne die ses sigma vlak te bedryf.Alternate :This paper is based on bottling process optimisation through continuous improvement. A case study was done at XYZ company. The Six Sigma Define, Measure, Analyze, Improve, and Control (DMAIC) methodology revealed that the bottling and capping processes were producing defects at 3 Sigma level. The 5 Whys, Pareto chart, fish bone diagram, and Suppliers, Inputs, Process, Outputs, Customers (SIPOC) model showed that loose-capped bottles (31.6%), under-fills (29.2%), and empty bottles (28.9%) caused the highest cost through poor quality. The monitoring system was designed to monitor the applied torque value, the capping head status, and the beverage temperature upon leaving the heat exchanger. The cooling system on the mix processor was designed using the closed loop control strategy. If the beverage temperature is not within 1 or 2 degrees Celsius, it is directed to secondary cooling;otherwise, it proceeds. The glycol inlet valve is actuated such that the flow of the coolant is adjusted to ensure that the primary cooling is efficient. The results show that it is possible to operate production within the Six Sigma level.

Discrete-time COVID-19 epidemic model with bifurcation and control.

The local dynamics with different topological classifications, bifurcation analysis and chaos control in a discrete-time COVID-19 epidemic model are investigated in the interior of $ \mathbb{R}_+^3 $. It is proved that discrete-time COVID-19 epidemic model has boundary equilibrium solution for all involved parameters, but it has an interior equilibrium solution under definite parametric condition. Then by linear stability theory, local dynamics with different topological classifications are investigated about boundary and interior equilibrium solutions of the discrete-time COVID-19 epidemic model. Further for the discrete-time COVID-19 epidemic model, existence of periodic points and convergence rate are also investigated. It is also investigated the existence of possible bifurcations about boundary and interior equilibrium solutions, and proved that there exists no flip bifurcation about boundary equilibrium solution. Moreover, it is proved that about interior equilibrium solution there exists hopf and flip bifurcations, and we have studied these bifurcations by utilizing explicit criterion. Next by feedback control strategy, chaos in the discrete COVID-19 epidemic model is also explored. Finally numerically verified theoretical results.

Pid-based with odometry for trajectory tracking control on four-wheel omnidirectional COVID-19 aromatherapy robot

Inhalation therapy is one of the most popular treatments for many pulmonary conditions. The proposed Covid-19 aromatherapy robot is a type of Unmanned Ground Vehicle (UGV) mobile robot that delivers therapeutic vaporized essential oils or drugs needed to prevent or treat Covid-19 infections. It uses four omnidirectional wheels with a controlled speed to possibly move in all directions according to its trajectory. All motors for straight, left, or right directions need to be controlled, or the robot will be off-target. The paper presents omnidirectional four-wheeled robot trajectory tracking control based on PID and odometry. The odometry was used to obtain the robot's position and orientation, creating the global map. PID-based controls are used for three purposes: motor speed control, heading control, and position control. The omnidirectional robot had successfully controlled the movement of its four wheels at low speed on the trajectory tracking with a performance criterion value of 0.1 for the IAEH, 4.0 for MAEH, 0.01 for RMSEH, 0.00 for RMSEXY, and 0.06 for REBS. According to the experiment results, the robot's linear velocity error rate is 2%, with an average test value of 1.3 percent. The robot heading effective error value on all trajectories is 0.6%. The robot's direction can be monitored and be maintained at the planned trajectory. © 2021 by the authors.

Design, Control, Modeling, and Simulation of Mechanical Ventilator for Respiratory Support

In the early stage of the 21st century, humankind is facing high medical risks. To the best of our knowledge, there is currently no efficient way to stop chains of infections, and hence citizens suffer significantly increasing numbers of diseases. The most important factor in this scenario is the lack of necessary equipment to cure disease and maintain our living. Once breath cannot be guaranteed, humans find themselves in a dangerous state. This study aimed to design, control, model, and simulate mechanical ventilator that is open-source structure, lightweight, and portable, which is proper for patients to cure themselves at home. In the scope of this research, the hardware platform for the mechanical design, implementation of control rules, and some trials of both simulations and experiments are presented as our methodology. The proposed design of ventilator newly features the bioinspired mechanism, finger-like actuator, and flow rate-based control. Firstly, the approximate evaluation of the lung model is presented with some physiological characteristics. Owing to this investigation, the control scheme was established to adapt to the biological body. Moreover, it is essential for the model to be integrated to determine the appropriate performance of the closed-loop system. Derived from these theoretical computations, the innovative concept of mechanical design was demonstrated using the open-source approach, and the real-world model was constructed. In order to estimate the driving torque, the hardware modeling was conducted using mathematical expressions. To validate the proposed approach, the overall system was evaluated using Matlab/Simulink, and experiments with the proposed platform were conducted in two situations: 20 lpm as a reference flow rate for 4 seconds and 45 lpm for 2.5 seconds, corresponding to normal breath and urgent breath. From the results of this study, it can be clearly observed that the system’s performance ensures that accurate airflow is provided, although the desired airflow fluctuates. Based on the test scenario in hardware, the RMS (root-mean-square) values of tracking errors in airflow for both cases were 1.542 and 1.767. The proposed design could deal with changes in airflow, and this machine could play a role as a proper, feasible, and robust solution to support human living.