In recent times, there has been a rapid surge in the advancement of technologies associated with Unmanned Aerial Vehicles (UAVs), particularly in the domains of sensors, networking, and processing. Consequently, substantial investments from both governments and industries have been directed towards the exploration of UAVs, aiming to enhance their performance for secure and dependable deployments. The evolution of design methodologies and the exploration of UAV systems have transitioned from single UAV applications to encompass multi-UAVs and cooperative UAV systems. These systems necessitate a heightened level of coordination and collaboration to execute tasks, demanding innovative networking models, approaches, and mechanisms tailored for highly mobile nodes, encompassing numerous intricate parameters and constraints. The present paper provides comprehensive insights and conducts a meticulous examination of UAV communication protocols, networking systems, architectures, and applications. Furthermore, it delves into UAV solutions while underscoring critical technical challenges and unresolved research issues that warrant further investigation and dedicated research and development endeavors. In this paper, we study some problems and solutions for The Command and Control (C2) aspect of UAV communication systems. We also give some directions for research in near future.

This article's primary goals are to provide design drawings, a description of the structure, an explanation of the working principle, and a kinematics calculation for text stamping machines. This machine has an electric motor, a gear-pinion transmission, a rotating disc-rod-slider mechanism and a hinged four-way mechanism. This is a simple, reasonably priced and useful device for administrative agencies' workstations. An ordinary administrative worker can also operate it. This device is about the same size as a laptop or printer. It operates by clamping the seal, stamping constantly onto A4 pages. The stamping speed can also be changed by varying the shaft speed of the electric motor. It is convenient, but it also has the disadvantage of requiring someone to put the paper in and take it out. The box frame of this machine is made of plastic or wood. Some transmission components are made of steel. When this machine works, the force applied to it and the force caused by it are very small, so in general it is very simple and safe. Keywords: Gear transmission – rack, rotating disc mechanism – connecting rod – slider, four-hinged mechanism, stamping machine.

Nigeria and developing countries are suffering from infectious diseases due to a mixture of determinants. Parable, rotavirus is a major concern that causes a lot of deaths and hospitalization among children under five of age. Therefore, it is imperative to have more understanding of the rotavirus. A literature review to form concepts were made under the following headings: Historical background of the Rotaviruses, General Characteristics of Rotaviruses, Classification of Rotaviruses, Structure of Rotavirus particle, Rotavirus protein, Non- structural proteins, Structure of Rotavirus genome, Genetic reassortment of Rotaviruses, Mechanisms of Rotavirus genetic diversity, Rotavirus infection, Rotavirus replication, Transmission of Rotaviruses, Incubation period of Rotaviruses, Pathogenesis of Rotavirus infection, Signs and symptoms of Rotavirus infection, Immunity to Rotaviruses, Laboratory diagnosis of Rotaviruses, Epidemiology of Rotaviruses, Treatment of rotavirus infection, Antiviral therapy, Other Therapies, Management of Rotavirus infection, Prevention of Rotavirus infections, General Preventive Measures, Hospital Infection Control Measures. This information would invariably help in gaining understanding the basics of Rotavirus that causes diarrhea in children.

This article presents how to speculate, design and simulate a mechanical horse based on the point of view of the military man Khong Minh, a talented character in the work "Three Kingdoms" (author La Quan Trung). The behavior of this type of horse closely resembles that of a real horse. That is, it can walk, run, carry goods or people. It is made mainly of wood or steel. The authors speculated that Khong Minh placed a leaf spring in the belly of the mechanical horse. Soldiers just need to rotate so that the leaf spring twists, it will store energy in the form of potential energy. Then, it slowly unfolds, and the potential energy is converted into kinetic energy, transmitting motion to the mechanisms connected to the horse's legs. Finally, the mechanical horse lifted his leg and was able to walk. Despite such speculation, when recreating a mechanical horse, our team of authors used a battery-powered motor instead of leaf springs and gear transmissions as a pre-assembled transmission part in the belly of the mechanical horse. We design additional parts such as the head, tail, belly, legs, etc. to create a complete mechanical horse. The design goal of the author's mechanical horse is to clear people's doubts about the "wooden buffalo mechanical horse" in the literary work "Three Kingdoms". At the same time, this type of mechanical horse is also applied as an amusement ride for people in tourist areas and as a children's toy in the family.

As a response to global warming and climate change, climate change adaptation aims to lessen the susceptibility of social and biological systems to relatively abrupt change and so counteract the effects of global warming. Openness and cooperation are key tenets of an adaptation strategy; as a result, mechanisms for a wide range of stakeholders are included in the creation and execution of adaptation strategies. However, few poor nations have made a point of involving stakeholders in decision-making processes for climate change adaptation. In many regions of the world, there is a notable dearth of concrete plans to include stakeholders in the adaptation of policy-making and implementation. This study uses Viet Nam as a case study to evaluate the level of stakeholder involvement in climate change adaptation strategies. The findings demonstrate that the Vietnamese government has adopted a "top-down" decision-making strategy, in which the government plays the primary role, communities and NGOs have a minimal impact on the creation and implementation of policies, and the private sector is only involved in the implementation phase. Stakeholder participation has generally been acknowledged in Vietnam, although the country's national climate change policies have not been adequately implemented. As a result, the policies for adaptation are unlikely to be effective in the unique settings of diverse places and may not be embraced by all stakeholders, which may ultimately limit adaptation activities. Viet Nam is advised to encourage participation by many stakeholders in the formulation of policy. Other countries can adopt the lessons from Vietnam while creating their adaptation policies.

Enzymes are biodegradable catalysts naturally present in living organisms. Enzymes can accelerate biochemical reactions by reducing the activation energy, and they are not consumed during reaction processes. Numerous applications of enzymes have been developed in biotechnology, industry, medicine, pharmaceuticals, food processing, biofuels, and so on. In this study, we develop a mathematical model describing enzymatic reactions with a Ping-Pong mechanism and competitive substrate inhibition. In order to obtain insights into the model behaviors, we use Python software to obtain numerical solutions for the model. Some discussions on the numerical results is provided. Finally, we briefly discuss a potential application of the model and some future work.

Activity recognition is one of the preliminary steps in designing and implementing assistive services in smart homes. Such services help identify abnormality or automate events generated while occupants do as well as intend to do their desired Activities of Daily Living (ADLs) inside a smart home environment. However, most existing systems are applied for single-resident homes. Multiple people living together create additional complexity in modeling numbers of overlapping and concurrent activities. In this paper, we introduce a hybrid mechanism between ontology-based and unsupervised machine learning strategies in creating activity models used for activity recognition in the context of multi-resident homes. Comparing to related data-driven approaches, the proposed technique is technically and practically scalable to real-world scenarios due to fast training time and easy implementation. An average activity recognition rate of 95.83% on CASAS Spring dataset was achieved and the average recognition run time per operation was measured as 12.86 mili-seconds.