The laser radiation parameters control method based on the digital video system registration

The paper describes a method of a beam radiation parameters analysis. Such analysis bases on the laser beam registration in the plane of a diffusely reflecting screen and digital processing of the registered image. The algorithm of the laser beam spatial parameters determination is presented and realized programmatically. The experiment was carried out using a digital high-speed video system and a solid-state pulsed periodic laser based on a Cr3+: BeAl2O4 alexandrite crystal. A comparison of the proposed method with a standardized method based on the registration of radiation by a matrix photodetector is presented. The development of measure methods of the laser radiation parameters is necessary due to the appearance of new sources of laser radiation and their use in various applications.

Effect of Taking the Liberal Arts Course ‘Creative Thinking and Problem Solving’ on the Improvement of Creative Competencies of College Students in Science and Engineering －Focusing on Comparison Before and After COVID-19

This study was conducted to derive implications on how educational activities should be organized and operated for improving creative competency in online class situations by analyzing how it has changed in classes before and after COVID-19. These classes were taken by science and engineering students who took the ‘Creative Thinking and Problem Solving’ subject operated by N University. In order to achieve the goals of this study, a pre-post test related to creative competency was administered at the beginning and end of the semester to 92 students who took the face-to-face class in the second semester of 2019, and to 120 students who took the on-line class in the second semester of 2020. The research results are as follows: Creative competency was significantly improved in the face-to-face class, but not in the online class. Looking at each sub-competency of creative competency, both the challenge spirit and problem solving ability were significantly improved in the face-to-face class. Moreover, the student’s challenge spirit ability was significantly improved in the online class, but their problem solving ability was not significantly improved. These results were similar regardless of whether the instructor changed, or if the students’ grades changed. Also, the students’ gender had no bearing on these results either. Based on these research results, as well as on our educational goals and the content of the classes, the project activities involved in the ‘Creative Thinking and Problem Solving’ subject can be used in online classes in their current form. But this study suggested that strategies for improving students' problem-solving abilities need to be supplemented. Specifically, instructors should increase communication opportunities through the parallel use of the real-time remote video system, and should guide their students to become faithful to the team-based project activities through the sub-session function of the real-time remote video system. To this end, the university may consider changing two credits of two hours into two credits of three hours, or three credits of three hours. Universities also need to operate this subject in connection with extra-activities. It is also necessary for instructors to provide a support environment where students can freely meet using the real-time remote video system, and can engage in solving problems through their own initiative.

Analysis of Running Performance in the Offensive and Defensive Phases of the Game: Is It Associated with the Team Achievement in the UEFA Champions League?

Although associations between running performance (RP) with ball possession and team achievement in soccer are often hypothesized, actual knowledge of this association in elite soccer remains limited. Therefore, this study aimed to evaluate players’ RPs according to ball possession to determine its possible influence on team achievement in the UEFA Champions League (UCL). The players’ RPs (n = 244) were collected during UCL group stage matches (n = 20) in the 2020/21 season using the semiautomatic video system InStat Fitness. Then, players’ RPs were classified according to the specific playing position: central defenders (CD; n = 79), fullbacks (FB; n = 65), central midfielders (CM; n = 55), wide midfielders (WM; n = 28) and forwards (FW; n = 17). RPs were observed in the attacking phase (AP, i.e., when the team was in possession of the ball) and defensive phase (DP, i.e., when the team did not have possession of the ball) of the game, and included the total distance covered (m) and distance covered in different categories: walking (<7.1 km/h), jogging (7.1–14.3 km/h), running (14.4–19.7 km/h), high-intensity running (>19.8 km/h), high-speed running (19.8–25.1 km/h) and sprinting (>25.2 km/h). Team achievement was defined by the total group points earned (TGP) at the end of the group phase of the UCL and by match outcome (win, draw, loss) of single matches. The results indicated that the total, walking and jogging distances covered were negatively and positively associated with TGP (Pearson’s correlations from 0.30 to 0.73; all p < 0.05) in the AP and DP of the game, respectively. Won matches were characterized by significantly lower and higher values of total, walking and jogging distances covered in AP and DP of the game, respectively (F tests: from 7.15 to 22.5, all p < 0.01; all small to medium effect sizes). In addition, RPs in the AP and DP of the game explained only 37.2% of the variance in the TGP. These findings demonstrate that the influence of RP on team achievement in UCL is limited in both the AP and DP of the game.

An approximate mathematical model for estimating the influence of vibrations on attached elements of a mobile robot video system

The problem of constructing and applying of mathematical model for assessing the influence of vibrations on the attached elements of the video system of a mobile robot is solved. This robot is considered as a mobile platform for placing of the special equipment for various purposes. The analysis of mathematical models and the results of experimental studies of vibrations of multi-support wheeled machine and its structural elements has been conducted. On the basis of this analysis, the form of a stochastic mathematical model of vibrations of the structure of a mobile robot has been substantiated. The vibration model is specified as a correlation function or spectral density of a random process for various conditions of the robot’s movement. Differential equations of the shaping filter for modeling а random vibration process with given characteristics are presented. Differential equations for the probabilistic moments of the vibration process are presented. Based on the equations for the probabilistic moments and the proposed formula, an assessment of events, which consist in exceeding the vibration amplitude of a given level was carried out. These events are named as outliers of a random process and characterize the range within the basic properties of the equipment installed on the mobile platform are preserved. An analytical study of a mathematical model to determine the intensity of emissions of a random vibration process has been carried out. The probabilistic characteristics of the vibration process and the intensity of emissions are determined. The obtained theoretical results make it possible to assess the performance of the elements of a video system installed on a mobile platform and to formulate the basic requirements for tolerances for their parameters. The results of computer modeling clearly showed the efficiency of the proposed mathematical model for assessing the influence of vibrations.

The reception of Cameroon Films and home videos in student residential areas: the case of Bambili – Cameroon

Film as a medium of communication uses visual and auditory signs between senders and receivers. It is considered as one of the most influential areas of media. The art form in Cameroon is valorised more through the home video system caused principally by the closure of theatre halls and the advent of cable TV channels dedicated to the broadcasting of movies for home consumption and the emergence of new media. This study looks at the reception of these home videos particularly in the student residential area of Bambili – Cameroon. A total number of 500 students served as sample for the study whose results show that a majority of viewers choose films according to different criteria but mostly influenced by their horizons of expectations.

Micro- and macro-borderless surgery using a newly developed high-resolution (4K) three-dimensional video system

Objective Microsurgery using conventional optical microscopes or surgical loupes features a limited field of view and imposes a serious strain on surgeons especially during long surgeries. Here we advocate the micro- and macro-borderless surgery (MMBS) using a novel high-resolution (4K) three-dimensional (3D) video system. This study aimed to confirm the applicability of this concept in several surgical procedures. Methods We evaluated the possible use and efficacy of MMBS in the following experiments in porcine subjects. Experiment 1 (non-inferiority test) consisted of dissection and anastomosis of carotid artery, portal vein, proper hepatic artery, and pancreatoduodenectomy with surgical loupe versus MMBS. Experiment 2 (feasibility test) consisted of intra-abdominal and intra-thoracic smaller arteries anastomosed by MMBS as a pre-clinical setting. Experiment 3 (challenge on new surgery) consisted of orthotopic liver transplantation of the graft from a donor after circulatory death maintained by machine perfusion. Circulation of the cardiac sheet with a vascular bed in experiment 2 and liver graft during preservation in experiment 3 was evaluated with indocyanine green fluorescence imaging equipped with this system. Results Every procedure was completed by MMBS. The operator and assistants could share the same field of view in heads-up status. The focal depth was deep enough not to be disturbed by pulsing blood vessels or respiratory movement. The tissue circulation could be evaluated using fluorescence imaging of this system. Conclusions MMBS using the novel system is applicable to various surgeries and valuable for both fine surgical procedures and high-level surgical education.

Rancang Bangun Remotely Operated Vehicle (ROV) untuk Monitoring Kondisi Terumbu Karang di Perairan Bontang

Coral reefs and all the life in them are one of the natural resources owned by the Indonesian people that are invaluable. Bontang city, located in East Kalimantan, is dominated by the ocean. Observation of the condition of coral reefs has been carried out by diving (diving) or snorkeling. For certain conditions, such as difficult locations, it does not allow humans to dive and observe directly the condition of coral reefs. This study proposes an alternative observation of coral reefs in Bontang waters using ROV. ROV is an underwater explorer robot controlled by an operator with a control device. The ROV in this study uses the arduino mega2560 as a controller, the BTS7960 module as a motor driver, MS5540CM sensor, motor as a driver. The ROV is equipped with a camera to take pictures and display them on a monitor. The results show that the ROV can work in the water, the ROV movement can be controlled and can maneuver well. ROV can automatically maintain depth when not operated with a range of ± 5 cm. The camera video system works well. The image captured by the camera can be displayed on the monitor in realtime. From the test results, it was found that the delay was less than 1 second between the image captured by the camera and the image displayed.