Unmanned aerial vehicles (UAVs) offer solutions to issues like traffic congestion and labor shortages. We developed a distributed UAV management system inspired by virtual circuit and datagram methods in packet-switching networks. By installing houses with wireless terminals, UAVs navigate routes in a multi-hop network, communicating with ground nodes. UAVs are treated as network packets, ground devices are treated as routers, and their connections are treated as links. Activating all nodes as relays increases control message traffic and node load. To optimize connectivity, we minimize relay nodes, connecting non-relay nodes to the nearest relay. This study proposes four relay node selection methods: random selection, two adjacency-based methods, and our innovative approach using Multipoint Relay (MPR) from the Optimized Link State Routing Protocol (OLSR). We evaluated these methods according to their route construction success rates, relay node counts, route lengths, and so on. The MPR-based method proved most effective for UAV route construction. However, fewer relay nodes increase link collisions, and we identify the minimum relay density needed to balance efficiency and conflict reduction.

High-quality software tends to be expensive to develop and maintain because it is used in social infrastructures. In previous studies, a description format for High-quality software tends to be expensive to develop and maintain because it is used in social infrastructures. In previous studies, a description format for

Nowadays, Java is one of the world’s most used object-oriented programming languages for its dependability and portability. To assist the self-studies of novice students, we have developed the Java programming learning assistance system (JPLAS). JPLAS offers several types of exercise problems for different difficulties, including the grammar-concept understanding problem (GUP), the mistake correction problem (MCP), the element fill-in-blank problem (EFP), and the phrase fill-in-blank problem (PFP), where a question asks to answer the corresponding keyword or phrase in the given source code. Unfortunately, some students cannot solve them well as the difficulty level is ascending. In this paper, to help such students, we propose a hint function that will show the first or more characters of each correct answer word in the answer interface on a web browser for JPLAS, when requested. The use of this function by a student can be traced by a teacher to analyze the performance and problem difficulty. For evaluations, we generated three instances for GUP, MCP, EFP, and PFP respectively, and assigned them to junior students taking the Java programming course in Okayama University, Japan. Their answer results found that the proposal is effective in helping students solve exercise problems in JPLAS, but the thinking time needs to be adjusted for PFP.

Portrait drawing is effective in cultivating artistic skills and visual understanding for a lot of people. Since drawing facial features with proper proportions, structures, and spatial relationships is hard for novices with no professional guidance, we developed the Portrait-Drawing Learning Assistance System, which offers auxiliary lines to assist in the drawing of portraits by acting as references; these auxiliary lines are extracted by applying OpenPose and OpenCV to a facial image. The drawing exactness assessment method using the Localized Normalized Cross-Correlation algorithm is also implemented to evaluate drawing accuracy. Unfortunately, previous experiments involving the use of the Portrait-Drawing Learning Assistance System by novices found that Localized Normalized Cross-Correlation scores for eyes are relatively low compared with others because of two drawbacks: (1) eye boundaries are often blurred by eyelids and eyelashes, which can make eyes bigger, and (2) the iris and pupil are not considered in auxiliary lines. In this paper, we propose an improved eye auxiliary line for the Portrait-Drawing Learning Assistance System to address these concerns. For the first drawback, we shift the lines for eye boundaries outside and add hatching (a series of short line segments) to them. For the second one, we expand region of interest of an eye and apply the Canny edge detector to capture its iris and pupil. In a preliminary within-subject evaluation, eight graduate students at Okayama University used the previous and proposed eye auxiliary lines in Procreate on an iPad. The average localized NCC scores increased for both eye regions under the tested conditions. These results suggest that the proposed auxiliary line may improve immediate eye-region reproduction accuracy; however, they do not constitute definitive validation of drawing-skill learning.

Unmanned delivery technology using unmanned aerial vehicles (UAVs) has the potential to solve issues such as traffic congestion and labor shortages. We investigated a method to construct a route between the source and destination nodes in a wireless multi-hop network by installing a radio terminal in each house. If the relay functions of all nodes in the network are in operation, the number of control messages for route construction increases, and the message relay forwarding load of each node increases. Keeping all node pairs multi-hop connectivity, we establish a method to operate the relay function with as few nodes as possible. End nodes that have not activated the relay function connect to the relay node with the closest physical distance. In this paper, we propose methods for selecting nodes to operate the relay function. Specifically, one method is based on random selection, another method is based on the number of adjacent nodes, and a third method is based on the Multipoint Relay (MPR) of the Optimized Link State Routing Protocol (OLSR). For each method, we evaluate whether the route construction is available, the number of relay nodes, the total distance of constructed routes, and the distance in population-dense regions. We clarify the characteristics of each method, and the method based on MPR is the best for constructing a network suitable for UAV navigation routes. In addition, the smaller the number of relay nodes, the more unexpected collisions on the links due to route conflicts. We clarify the minimum node density required to apply the MPR method which reduces the number of relay nodes suppressing route conflicts.