Simulation of Tennis Match Scene Classification Algorithm Based on Adaptive Gaussian Mixture Model Parameter Estimation

This paper presents an in-depth analysis of tennis match scene classification using an adaptive Gaussian mixture model parameter estimation simulation algorithm. We divided the main components of semantic analysis into type of motion, distance of motion, speed of motion, and landing area of the tennis ball. Firstly, for the problem that both people and tennis balls in the video frames of tennis matches from the surveillance viewpoint are very small, we propose an adaptive Gaussian mixture model parameter estimation algorithm, which has good accuracy and speed on small targets. Secondly, in this paper, we design a sports player tracking algorithm based on role division and continuously lock the target player to be tracked and output the player region. At the same time, based on the displacement information of the key points of the player’s body and the system running time, the distance and speed of the player’s movement are obtained. Then, for the problem that tennis balls are small and difficult to capture in high-speed motion, this paper designs a prior knowledge-based algorithm for predicting tennis ball motion and landing area to derive the landing area of tennis balls. Finally, this paper implements a prototype system for semantic analysis of real-time video of tennis matches and tests and analyzes the performance indexes of the system, and the results show that the system has good performance in real-time, accuracy, and stability.

Decreasing Labor Pain through Sacralist Counter-pressure Therapy Using Tennis Ball in the Mother during the Labor Process

BACKGROUND: Labor pain is a physiological process caused by the contraction of uterus muscle as an effort to open the cervix and push the baby’s head toward the pelvis. One of the treatments giving by nurses to reduce the pain is by counter-pressure therapy. AIM: The aim of the study was to determine the effect of counter-pressure therapy using tennis balls toward the pain level in the first stage during the active phase of labor. METHODS: It was a quasi-experimental study with pretest-posttest one group design. The population in this study was patients with active phase I delivery in PKU Muhammadiyah Hospital of Temanggung. A total of 26 respondents were selected through purposive sampling technique. The data were analyzed using Wilcoxon matched paired test. RESULTS: The pain intensity in 26 respondents (100%) in the first stage during the active phase of labor before the treatment was categorized as severe pain. However, after the implementation of the counter-pressure therapy using tenis ball, the pain intensity was categorized as moderate in 18 respondents (69.2%) and severe in the rest of the respondents (30.8%). CONCLUSION: Counter-pressure massage therapy using a tennis ball was effective in reducing the level of pain in the first stage during the active phase of labor with a p = 0.000 (α < 0.05).

Investigation of the manifestation of the reaction of choice among combatants after performing exercises with tennis balls

Purpose: to investigate the dynamics of changes in the selection reaction of combatants after performing exercises with tennis balls. Materials and methods. The study used the following methods: analysis of scientific and methodological information, Internet sources and generalization of advanced practical experience, psychophysiological research methods, methods of mathematical statistics. The study involved 21 combatants, age 19,7±1,12 years. Of these: 73 % are candidates for Master of Sports of Ukraine, 27 % are Master of Sports of Ukraine. The selection reaction was assessed using the Reaction RCHR test, developed at the Department of Martial Arts of the KSAPC for tablet personal computers. A feature of the proposed test is the ability to simultaneously obtain both the selection reaction values and the heart rate (heart rate) value using a chest heart rate sensor (Bluetooth 4.0). The test result included the following indicators: the average value of the choice reaction and heart rate for the test, the average values of the choice reaction and heart rate at the first, second and third stages (10 attempts in each stage). To study the dynamics of changes in the manifestation of the choice reaction, the participants were asked to perform the task in the following sequence: 1. Test to determine the choice reaction; 2. Exercises with tennis balls (2 minutes) 3. Test to determine the reaction of choice. Results: of the study showed that, on average, the result of passing the test after doing exercises with tennis balls was improved: the first stage – by 11 %, the second stage – by 7 %, the third stage – by 6 %. The heart rate values at the end of the test are less than at the beginning by 4,9 beats/min (at the first test run) and by 16,7 beats/min (at the second test run). This reaction of the cardiovascular system is natural and is due to the recovery process of the studied combatants after the load. Conclusions. It was found that the performance of exercises with tennis balls has a positive effect on the manifestation of the choice reaction; this is the basis for recommending these exercises to activate the mechanisms of control of specialized movements of combatants. The efficiency and convenience of the Reaction RCHR test allows it to be used as an express control of the athlete's functional state. Keywords: combatants, selection reaction, movement control, recovery, heart rate

UTILIZATION OF STATIONARY UNDERWATER SURVEILLANCE SYSTEMS FOR THE ESTIMATION OF UNDERWATER CURRENTS AND SEA DISTURBANCE PARAMETERS

Системы стационарного подводного видеонаблюдения, разработанные в ТОИ ДВО РАН, помимо решения задач наблюдения за состоянием морской биоты прибрежных акваторий залива Петра Великого (Японское море) могут применяться для оценивания характеристик морского волнения и подводных течений. Эти характеристики важны как в контексте сопровождения наблюдений за жизнедеятельностью морских организмов информацией о гидрологических условиях их существования, так и сами по себе – как важные параметры состояния природной среды. В статье рассмотрены несколько методик измерения сигналов вариаций подводных течений и оценивания на их основе частотных свойств поверхностного волнения. Основная идея состоит в отслеживании на основе анализа видео горизонтальных движений легких маркеров под воздействием на них течений. В первой части работы приведены примеры использования искусственных маркеров двух видов – закрепленных на тонкой нити теннисных шариков с небольшой положительной либо отрицательной плавучестью и установленных на дне вертушек. Показано, что при небольших глубинах установки камер частотные свойства сигналов горизонтальных движений маркеров хорошо воспроизводятся в сигналах поверхностного волнения в диапазонах ветровых волн, корабельных волн, волнения зыби, сейшевых колебаний уровня моря с периодами от десятков секунд до десятков минут. Во второй части работы рассмотрены технологии измерений, основанные на использовании естественных маркеров–полей органических и неорганических взвесей, перемещаемых водными потоками перед камерой, либо растительности, изменяющей свой наклон под действием течений. Они могут применяться при отсутствии либо выходе из строя искусственных маркеров. Stationary systems for underwater video surveillance designed in POI FEB RAS apart from solving tasks of marine biot monitoring in the off-shore strip of Peter the Great Bay can be used for estimating characteristics of sea disturbance and underwater currents. These characteristics are essential both for supplementing the observations of life activities of marine organisms with hydrological existence conditions and by itself, as vital parameters of environmental conditions. This work considers several methods of measuring signals of variations of underwater currents and estimating frequency properties of sea disturbance on its basis. The main idea is to track horizontal movements of light markers driven by underwater currents based on the video analysis. The first part of the article presents examples of the utilization of markers of two types: tennis balls with slightly positive or negative buoyancy mounted on thin thread and propellers mounted on the bottom. It is shown that at a small depth of the camera installation, the frequency properties of the signals of markers horizontal movements are easily reproduced in signals of sea surface disturbance in the range of wind waves, sea swells, seiche oscillations of the sea level with a period from tens of seconds to tens of minutes. The second part of the article considers technologies of measurements based on the utilization of natural markers, such as fields of organic and inorganic suspended matter moved by water streams in front of a camera or submerged vegetation, which inclination angle is changed under the influence of currents. These approaches can be used in the absence of artificial markers or their failure.

AN ATTEMPT TO INDUCE POSTACTIVATION POTENTIATION TO IMPROVE KAYAK SPRINT PERFORMANCE USING AN ON-WATER KAYAK-SPECIFIC WARM UP

This study explores whether an on-water kayak-specific resistance exercise (KSRE) performed during the warm-up period can induce postactivation potentiation (PAP) to improve subsequent kayak-sprint performance. The KSRE involves stringing several tennis balls around the boat’s hull to induce drag while paddling. In a laboratory setting, 10 well-trained male ([Formula: see text]) and female ([Formula: see text]) kayakers performed three repetitions of the single-arm seated-row (SASR) at 91% one-repetition maximum to induce PAP and were assessed for their peak power output while performing SASR on the Keiser machine at two-minute intervals up to 16 min. Each individual’s latency period for the onset of PAP during this exercise was recorded. In separate sessions, athletes performed in random, a 30 m kayak-sprint in a swimming pool setting after either control (no pre-performance loading) or experimental (post-PAP induction via the KSRE taking into account the individual’ onset of PAP latencies period obtained in the laboratory) conditions. Criterion measures of boat velocities of the third and fourth stroke from the start and 30 m sprint times, assessed using video, were not significantly different between control and experimental conditions. The translation of increased power output elicited via PAP using land-based resistance exercises into water-based resistance exercises to improve kayak-sprint performance remains a challenge.