• Environmental Engineering Research
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• v.25 no.4
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• pp.515-521
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• 2020

Nowadays, due to various pollution sources, it is essential for environmental scientists to monitor water quality. Phytoplanktons form the end of the food chain in water bodies and are one of the most important biological indicators in water pollution studies. Chlorophyll-A, a green pigment, is found in all phytoplankton. Chlorophyll-A concentration indicates phytoplankton biomass directly. Therefore, Chlorophyll-A is an indirect indicator of pollutants, including phosphorus and nitrogen, and their refinement and control are important. The present study, Moderate Resolution Imaging Spectroradiometer (MODIS) satellite images were used to estimate the chlorophyll-A concentration in southern coastal waters in the Caspian Sea. For this purpose, Multi-layer perceptron neural networks (NNs) were applied which contained three and four feed-forward layers. The best three-layer NN has 15 neurons in its hidden layer and the best four-layer one has 5 in each. The three- and four- layer networks both resulted in similar root mean square errors (RMSE), 0.1($\frac{{\mu}g}{l}$), however, the four-layer NNs proved superior in terms of R² and also required less training data. Accordingly, a four-layer feed-forward NN with 5 neurons in each hidden layer, is the best network structure for estimating Chlorophyll-A concentration in the southern coastal waters of the Caspian Sea.

• Journal of Korea Game Society
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• v.11 no.4
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• pp.27-35
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• 2011

Concentration is one of the most important factor in learning ability. It is important to improve concentration for learning ability. Most digital kids have been accustomed to addictive media like games since childhood, so traditional methods of teaching and learning has been difficult to give interests for them. Therefore introducing a new teaching methods was inevitable for students with low concentration. This is an experiment to prove the hypothesis that the concentration training by certain serious game would be helpful for improving students' concentration. Not only some serious games but also meditation by music was effective to improve concentration in the experiment. Average people is hard to immerge in meditation. but some serious games involve fun factors like curiosity, challenges, competitions and rewards. Games are not more negative to young people, will be helpful to society in various forms.

• PNF and Movement
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• v.17 no.1
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• pp.57-68
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• 2019

Purpose: This study is an investigation of the effects of long-term smart phone usage and of stretching on muscle stiffness, concentration, and visual acuity. Methods: Forty healthy young adults voluntarily participated in the study and were measured for muscle stiffness, concentration, and visual acuity before smartphone usage and after 30 minutes, 60 minutes, and 90 minutes of smartphone usage. The participants were randomly allocated to the intervention group (n=20) and the control group (n=20). Five minutes after the stretching exercise and eye exercise intervention, the participants were remeasured. Results: After long-term smartphone usage, increases in muscle stiffness and concentration were statistically significant (p<0.05), whereas decreases in visual acuity were statistically significant (p<0.05). After the stretching exercise and eye exercise intervention, muscle stiffness significantly decreased (p<0.05) and visual acuity significantly increased (p<0.05). Concentration, according to the stretching exercise and eye exercise intervention, showed no significant pre- or post-test difference. Conclusion: The results from this study indicate that long-term smartphone usage effectively improved concentration but increased muscle stiffness and decreased visual acuity. Appropriate stretching and eye movement during long-term smartphones usage should mitigate the effects on muscle stiffness and visual acuity. Furthermore, smartphones should be considered an effective tool for concentration training when coupled with the development of appropriate applications.

• Journal of Advanced Navigation Technology
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• v.25 no.6
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• pp.576-581
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• 2021

Compared to a low concentration, a high concentration clearly entails limitations in terms of predictive performance owing to differences in its frequency and environment of occurrence. To resolve this problem, in this study, an artificial intelligence neural network algorithm was used to classify low and high concentrations; furthermore, two prediction models trained using the characteristics of the classified concentration types were used for prediction. To this end, we constructed training datasets using weather and air pollutant data collected over a decade in the Cheonan region. We designed a DNN-based classification model to classify low and high concentrations; further, we designed low- and high-concentration prediction models to reflect characteristics by concentration type based on the low and high concentrations classified through the classification model. According to the results of the performance assessment of the prediction model by concentration type, the low- and high-concentration prediction accuracies were 90.38% and 96.37%, respectively.

• Korean Journal of Exercise Nutrition
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• v.16 no.2
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• pp.65-71
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• 2012

Oxygen is the final acceptor of electron transport from fat and carbohydrate oxidation, which is the rate-limiting factor for cellular ATP production. Under altitude hypoxia condition, energy reliance on anaerobic glycolysis increases to compensate for the shortfall caused by reduced fatty acid oxidation [1]. Therefore, training at altitude is expected to strongly influence the human metabolic system, and has the potential to be designed as a non-pharmacological or recreational intervention regimen for correcting diabetes or related metabolic problems. However, most people cannot accommodate high altitude exposure above 4500 M due to acute mountain sickness (AMS) and insulin resistance corresponding to a increased levels of the stress hormones cortisol and catecholamine [2]. Thus, less stringent conditions were evaluated to determine whether glucose tolerance and insulin sensitivity could be improved by moderate altitude exposure (below 4000 M). In 2003, we and another group in Austria reported that short-term moderate altitude exposure plus endurance-related physical activity significantly improves glucose tolerance (not fasting glucose) in humans [3,4], which is associated with the improvement in the whole-body insulin sensitivity [5]. With daily hiking at an altitude of approximately 4000 M, glucose tolerance can still be improved but fasting glucose was slightly elevated. Individuals vary widely in their response to altitude challenge. In particular, the improvement in glucose tolerance and insulin sensitivity by prolonged altitude hiking activity is not apparent in those individuals with low baseline DHEA-S concentration [6]. In addition, hematopoietic adaptation against altitude hypoxia can also be impaired in individuals with low DHEA-S. In short-lived mammals like rodents, the DHEA-S level is barely detectable since their adrenal cortex does not appear to produce this steroid [7]. In this model, exercise training recovery under prolonged hypoxia exposure (14-15% oxygen, 8 h per day for 6 weeks) can still improve insulin sensitivity, secondary to an effective suppression of adiposity [8]. Genetically obese rats exhibit hyperinsulinemia (sign of insulin resistance) with up-regulated baseline levels of AMP-activated protein kinase and AS160 phosphorylation in skeletal muscle compared to lean rats. After prolonged hypoxia training, this abnormality can be reversed concomitant with an approximately 50% increase in GLUT4 protein expression. Additionally, prolonged moderate hypoxia training results in decreased diffusion distance of muscle fiber (reduced cross-sectional area) without affecting muscle weight. In humans, moderate hypoxia increases postprandial blood distribution towards skeletal muscle during a training recovery. This physiological response plays a role in the redistribution of fuel storage among important energy storage sites and may explain its potent effect on changing body composition. Conclusion: Prolonged moderate altitude hypoxia (rangingfrom 1700 to 2400 M), but not acute high attitude hypoxia (above 4000 M), can effectively improve insulin sensitivity and glucose tolerance for humans and antagonizes the obese phenotype in animals with a genetic defect. In humans, the magnitude of the improvementvaries widely and correlates with baseline plasma DHEA-S levels. Compared to training at sea-level, training at altitude effectively decreases fat mass in parallel with increased muscle mass. This change may be associated with increased perfusion of insulin and fuel towards skeletal muscle that favors muscle competing postprandial fuel in circulation against adipose tissues.

• The Journal of Korean Society for School & Community Health Education
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• v.2 no.2
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• pp.1-22
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• 2001

The purpose of this study was to evaluate the effect of moderate physical exercise program on a number of immune parameters in middle school boys($15.07{\pm}0.39$ yrs). 14 volunteers were included in this physical exercise program. They were randomly assigned to an experiment(7) and a control(7) group. Measurements were taken before program, after 4 weeks and 8 weeks of aerobic exercise for immune parameters such as number of circulating leukocytes, concentration of WEC subsets, lymphocyte subsets, immunoglobulins, complements, and number of blood adipose components. Aerobic exercise consisted of track running at a work intensity of 65% HRmax, $45{\sim}55$ min per day, 3 times per week, and for 8 weeks. The results are as follows; 1. There were no significant changes between and within groups in the number of circulating leukocytes and concentration of WEC subsets. 2. There were significant(p<.05) changes in concentration of B-cell between groups, and T-cell, helper T-cell, and B-cell within experimental group. 3. There were no significant changes between and within groups in concentration of complements. 4. There were significant(p<.05) changes in concentration of IgG between groups and within experimental group. 5. There were significant(p<.05) changes in concentration of TG between groups, and TG, HDL-C and LDL-C within experimental group. In conclusion, the moderate exercise training for 8 weeks can be beneficial on immune function and decrease the concentration of flood adipose components in adolescents.

• Journal of Korea Entertainment Industry Association
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• v.13 no.1
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• pp.225-233
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• 2019

The study was to find out the effects of computer game and stretching on muscle tone and concentration. The subjects were 30 adults, who were divided into 15 stretching group and 15 control group after applying computer game for 120 minutes. The subjects measured muscle tone and concentration before experiment, the same measurements were made before and after applying the stretching. The muscle tone was respectively measured after 60 minutes and 120 minutes of computer game. The results showed that muscle tone increased significantly after 60 minutes and 120 minutes of computer game, and significantly decreased in the stretching intervention group. Concentration increased significantly after computer game, but there was no significant difference after application of stretching. In this study, computer game increased muscle tone and concentration, and stretching decreased increased muscle tone. Therefore, proper stretching after computer games will reduce musculoskeletal diseases caused by increased muscle tone, and development of appropriate game contents will be an effective tool for concentration training.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.5
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• pp.1254-1260
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• 2006

The purpose of this study was to the Pre-Post submaximal exercise for analyze the Blood Lactate, LDH(Lactate Dehydrogenase) and Glucose in the runners. The subjects were 12 volunteers 6 sprinters and 6 distance runners who agreed to intention of this study. Subjects peformed until possible all-out trials. Blood samples were taken from a Ante cubital vein Pre-Post exercise and every rest 5min during the all-out trial. The results obtained were summarized as follow; 1) Blood Lactate of Pre-Post exercise in treadmill test showed no significant difference between sprinters and distance runners, but showed significant in sprinters and distance respectively. 2) Serum LDH of Pre-Post exercise in treadmill test showed no significant difference between sprinters and distance runners, and that showed no significant in sprinters and distance respectively. 3) Blood Glucose of Pre-Post exercise in treadmill test showed no significant difference between sprinters and distance runners, and showed no significant in distance, but showed significant in sprinters. These data indicate first that the value of 4mmol/${\ell}$, commonly referred to as OBLA(Onset of Blood Lactate),may often underestimate the upper limit of tolerance to lactate during a maximal endurance peformance test until all-out. second, our date suggested that the sprinters exercise decreases serum LDH activities and the distance increases serum LDH activities. therefore serum LDH concentration changed following a different exercise. Third. for the concentration of the glucose in blood the sprinters was show to be higher. However it needs more studies to find out the relationship between this result and the fitness factor. therefor, since the runners has an intermittent characteristic which includes a frequent momentary change, it needs the fitness training that being consisted of various training. in the training method, it needs the training process which is from the whole fitness to specific fitness to improve general physical ability.

• Journal of Nutrition and Health
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• v.35 no.8
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• pp.825-833
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• 2002

The effects of dietary supplementation of Eleutherococcus senticosus, taurine and carnitine on maximal endurance exercise performance along with other related parameters were evaluated in rats that underwent aerobic exercise training for 6 weeks. Thirty-two male rats (4 weeks old) were randomly divided into 4 groups, and fed experimental diets and/or aerobic exercise trained according to the protocol: SC (sedentary control group), EC (exercise-trained control group), EE (exercise-trained Eleutherococcus senticosus-supplemented group), and EETC (exercise-trained Eleutherococcus senticosus, taurine and carnitine-supplemented group). The food efficiency ratio of EC rats was significantly lower than the value for SC rats (p < 0.01). Exercise-trained control animals (92 $\pm$ 8.8 min) could run significantly longer until exhausted on the treadmill than sedentary control rats (11 $\pm$ 0.8 min) (p < 0.001). Animals fed an Eleutherococcus senticosus-supplemented diet, and an Eleuthherococcus sonticosus, taurine and carnitine- supplemented diet while undergoing aerobic exercise training for 6 weeks exhibited, respectively, 8 and 5 minutes longer running performance until exhausted than the rats fed the control diet. The gastrocnemius muscle glycogen concentration of the rats, measured at 48 hours post maximal exercise performance test, was 43% higher in EC rats than the value for SC rats (p < 0.05), but was not different among EC, EE, and EETC rats. The mitochondrial citrate synthase activity of the soleus muscle was significantly higher in EC rats compared to the value for SC rats (p < 0.01), and showed a tendency to increase, without statistical significance, in EE or EETC rats compared to the value for EC rats. These results indicate that aerobic exercise training for 6 weeks significantly improved maximal exercise performance, muscle glycogen content along with citrate synthase activity, which are important in the energy metabolism of muscle under aerobic exercise. Dietary supplementation of Eleutherococcus senticosus in rats while undergoing aerobic exercise training improved maximal endurance exercise performance without significantly affecting muscle glycogen content and enzyme activities involved in energy metabolism during exercise. Taurine and carnitine supplementation failed to show an additive effect on maximal endurance exercise performance when consumed along with Eleutherococcus senticosus.

• The Journal of Korean Physical Therapy
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• v.11 no.3
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• pp.159-175
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• 1999

The purpose of this study lies in providing the basic materials for wrestlers' control of health and physical strength, the preventive, measure for injury during a practice or a game and the scientific training method for upgrading competitive power in a game. The result of analyzing the occurring tendency and therapeutical actions and attitude of sports injury, taking the 258 wrestlers from a high school, an university and pro-team as the object of study through a questioning sheet are like following. 1. Among every wrestlers' causes of injury, the main cause was a physical collision occupying $\50\%$, and an excessive training occupied $30\%$. on the contrary, the unsatisfied wrestler's cause of injury was a shortage of mental concentration and a burden of weight, occupying each $19\%$ and $17\%$. Therefore in order to prevent the injury, you should take care of especially in time of physical collision in a practice or a grme and prevent an excessive training. 2. The seasion with the most frequent occurrence of injury is the winter$(78\%)$, and in the spring and summer$(5.5\%)$, the frequency of occurrence of injury is very low. In the meantime, considering by occurring time, during a practice$(95\%)$ the injury occurs most frequently and during a game$(5\%)$ occure least frequently. Therefore, in order to reduce the injury, you should warm up sufficiently before the training and the practice and concentrate all of you attention and mind. 3. The injury occurs most highly in the afternoon hours occupying about $80\%$, and a little in the dawn and morning hours but in the contrary rarely in the night. 4. As the wrestler's injury type, the injury on muscles and tendons occupies the most to take $65\%$ of the whole injuries.