• Korean Journal of Applied Biomechanics
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• v.17 no.3
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• pp.69-80
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• 2007

The purpose of this study was to investigate the difference of ground reaction forces of swimming athletes during their starting motion and to find out the most effective starting motions which were used in swimming athletes. The subjects were 9 male and 8 female high school swimming athletes who were athletic career over 7 years and used three starting motions in competition. The ground reaction forces were measured from each athletes performing three starting motion each of the open grap starting motion, closed grap starting motion and track starting motion. For the measurement, the force platform of AMTI company was utilized, and the analysis on measured ground reaction forces were used of Biosoft(Ver. 1.0). The items measured were stance time, Fz max deceleration force and Fz max deceleration force time, Fz mid stance force and Fz mid stance force time, Fz max acceleration force and Fz max acceleration force time, Torque maximum and Torque maximum time, Torque average, Excursion along Y axis of center of pressure of foot, Excursion along X axis of center of pressure of foot, Length of center of pressure of foot, Average velocity of center of pressure of foot. The data measured by the closed grap starting motion, open grap starting motion and track starting motion were analyzed by one-way repeated ANOVA. The results were as follows ; 1. The Fz max deceleration force time, Fz mid stance force, Fz max acceleration force, Torque maximum and Torque maximum time, Excursion along Y axis of center of pressure of foot, Average velocity of center of pressure of foot were significantly fast and large in the closed grap starting motion then open grap starting motion and track starting motion. 2. The Excursion along Y axis of center of pressure of foot was significantly long in the closed grap starting motion then open grap starting motion and track starting motion.

• Biomolecules & Therapeutics
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• v.27 no.4
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• pp.349-356
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• 2019

Behavioral analysis in mice provided important contributions in helping understand and treat numerous neurobehavioral and neuropsychiatric disorders. The behavioral performance of animals and humans is widely different among individuals but the neurobehavioral mechanism of the innate difference is seldom investigated. Many neurologic conditions share comorbid symptoms that may have common pathophysiology and therapeutic strategy. The forced swim test (FST) has been commonly used to evaluate the "antidepressant" properties of drugs yet the individual difference analysis of this test was left scantly investigated along with the possible connection among other behavioral domains. This study conducted an FST-screening in outbred CD-1 male mice and segregated them into three groups: high performers (HP) or the active swimmers, middle performers (MP), and low performers (LP) or floaters. After which, a series of behavioral experiments were performed to measure their behavioral responses in the open field, elevated plus maze, Y maze, three-chamber social assay, novel object recognition, delay discounting task, and cliff avoidance reaction. The behavioral tests battery revealed that the three groups displayed seemingly correlated differences in locomotor activity and novel object recognition but not in other behaviors. This study suggests that the HP group in FST has higher locomotor activity and novelty-seeking tendencies compared to the other groups. These results may have important implications in creating behavior database in animal models that could be used for predicting interconnections of various behavioral domains, which eventually helps to understand the neurobiological mechanism controlling the behaviors in individual subjects.

• Journal of Environmental Science International
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• v.32 no.2
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• pp.99-120
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• 2023

The community structure of benthic macroinvertebrates in Upo wetland was identified, and the biological water quality was evaluated. In addition, through statistical analysis of current and literature data, ecological changes over time were evaluated for each wetland. Benthos were quantitatively collected in March, June, and September of 2020 and 2021, and 4 phyla, 5 classes, 16 orders, 42 families, 81 species and 3,406 individuals were identified. In the functional feeding group of Upo wetland, predators were dominant with 34 species (45.95%) and 1,504 individuals (41.84%). In the habitual dwelling group, sprawlers and swimmers showed the highest proportion in the number of species and individuals. Average biological indices in Mokpo and Upo were the highest and lowest, respectively, and it is considered that Mokpo maintains the healthy ecosystem for benthic macroinvertebrates. Community stability was high in Upo, and other wetlands are thought to be stabilizing. The ecological score of benthic macroinvertebrate community is considered to be more suitable index among three biological water quality evaluation indices for the environmental evaluation of Upo wetland. The evaluation results on changes in environmental quality showed that Upo has stable ecosystem without significant change, Mokpo and Sajipo have significant increases in some indices.

• Korean Journal of Environment and Ecology
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• v.30 no.1
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• pp.58-70
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• 2016

An investigation was carried out to study the diversity of aquatic insects, functional feeding groups (FFGs), habitat oriented groups (HOGs), and species-specific distribution in the Taean area in Korea from June to August, 2015. As a result, a total of 72 species belonging to 30 families and six orders were identified in all the investigated regions. Odonata (22 spp.: 30.56%) was the largest group in species richness followed by Coleoptera (21 spp.: 29.16%), Hemiptera (17 spp.: 23.61%) and Diptera (8 spp.: 11.11%) while for Ephemeroptera and Trichoptera, only two species (2.78%) were found. In addition, Plecoptera and Megaloptera inhabiting clean and flowing waters were not found. In the FFGs, predators (48 spp.: 66.67%) were relatively larger as represented by Odonata, Coleoptera, and Hemiptera, whereas shredders and scrapers were lower in proportion. The dominant groups of HOGs were swimmers (24 spp.: 33.33%), climbers (18 spp.: 25.0%), and sprawlers (12 spp.: 16.67%), which were characterized as aquatic insects community of island. Four species: Cybister lewisianus Sharp, Helophorus auriculatus Sharp, Agrypnia pagetana Curtis, Diplonychus esakii Miyamoto & Lee that are designated as Endangered, Near Threatened, and Vulnerable (Korean Red List) have been found to inhabitthe Taean area. Also, two species belonging to the exportable species group (Ceriagrion auranticum Fraser, Paracercion melanotum (Selys)) and one species belonging to the climate-sensitive biological indicator group (Ischnura elegans (Van der Linden)) were identified. In this study, four significant species including the Endangered are presented on the Korean distribution map based on the information in the national ecosystem survey accumulated for 7 years (2006-2012) by the Ministry of Environment.

• Korean Journal of Environment and Ecology
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• v.26 no.1
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• pp.46-56
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• 2012

Benthic macroinvertebrates were investigated in Hoeongseong Lake region from March to October 2010, Korea. Macroinvertebrate communities, composition of the functional feeding groups, habitiat oriented groups and the biological water quality were assessed above and below Hoeongseong Dam in the lake region. Six sites, two (St.1~2) above the lake, two (St. 3~4) into the lake, and two (St. 5~6) below the dam, were selected for quantitative (Surber sampler $30cm{\times}30cm$, mesh size 0.2 mm) and qualitative (Hand net) samplings of benthic macroinvertebrates. As a result, a total of 83 species belonging to 43 families, 17 orders, 8 classes, and 5 phyla were recognized. The EPT-group (50 spp. : 60.24%) that is major taxa or EPT-group plus Diptera (61 spp. : 73.49%) occupied most of benthic macroinvertebrates community. Based on quantitative sampling, the number of benthic maroinvertebrates above the lake was 2,399 individuals including 54 species, 28 families, 11 orders, 4 classes, and 4 phyla, whereas 510 individuals including 16 species, 12 families, 7 orders, 4 classes, and 3 phyla in the lake and 626 individuals including 62 species, 33 families, 13 orders, 6 classes, and 4 phyla below the dam were collected respectively. Dominance index was the highest, with 0.82-0.93 ($0.87{\pm}0.05$) in Hoeongseong lake (St. 3-4), diversity index was 3.04-3.16 ($3.10{\pm}0.06$), evenness index was 0.79-0.85 ($0.82{\pm}0.03$), and richness index was 7.27-8.52 ($7.90{\pm}0.63$), which were relatively higher below the dam sites. In the functional feeding groups, collector-gatherers and collector-filterers were the highest in the whole sites, and predators (Micronecta sedula) was appeared highly in the lake. Moreover, swimmers, burrowers, and clingers were considerably occupied in all collecting sites. The result of the DCA, similarity analysis, and MRPP were well reflective of the composition of lake and stream macroinvertebrates. ESB indicate that the lake sites were evaluated heavily polluted under priority improvement waters. Also, Semisulcospira gottschei, Ecdyonurus kibunensis, Epeorus pellucidus, Rhoenanthus coreanus, Stenelmis sp., and Cheumatopsyche brevilineata are considered as an indicator species above and below Hoeongseong Lake, whereas Macrobrachium nipponense and Micronecta sedula are indicated in the lake.

• Journal of Life Science
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• v.32 no.4
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• pp.325-330
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• 2022

While swimming is a very popular competitive sports activity, swimming injuries are unique due to the repetitive nature of the swimming stroke and demanding training programs that can result in upper limb overuse. Therefore, the primary objective of this review was to analyze swimmers' injury areas, injury types by stroke type, and swimming rehabilitation, as well as to discuss safety management for improving swimming performance. In this study, the injuries incurred in swimming events were discussed in the order of upper limb injuries (neck, shoulder, arm, and wrist), lower limb injuries (knee and ankle), and waist injuries. An analysis by stroke type found that shoulder injuries occurred most often with freestyle, backstroke, and butterfly strokes, followed by rotator cuff injury, impingement syndrome, and SLAP (superior labral tear from anterior to posterior) lesions. Knee injuries were associated with the breaststroke, whereas spinal cord injuries occurred with the breaststroke and butterfly stroke. Finally, back injuries were associated with the butterfly stroke. During the freestyle stroke, the shoulder undergoes repetitive overhead movement; hence, shoulder and musculoskeletal pain are the most common and well-documented complaints of swimmers. For safety management, coaches and instructors must ensure that athletes do sufficient warm-up and cool-down exercises to avoid injuries. In case of an injury, they should be familiar with first aid measures so that secondary damage can be prevented with its quick application. In addition, coaches and instructors need to be trained in injury prevention and treatment so that they can provide appropriate rehabilitation treatment for athletes. Although swimming-related injuries cannot be completely eliminated, to reduce them to a minimum, leaders need the knowledge to apply scientific and systematic training principles and methods individualized for each athlete.

• The Korean Journal of Ecology
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• v.16 no.4
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• pp.489-499
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• 1993

Drifting aquatic insects were collected with using drift nets in the middle reaches of the Paenae stream. a tributary of the Naktong River in Korea, in four seasons from August 1989 to May 1990. During the study period, 6 orders and 31 families were collected. Drifted insects were the most diverse in autumn, while the number of collected individuals was the highest in spring. The abundant groups were the primary consumers such as Ephemeroptera and Diptera including Heptagenidae, Baetidae, and Chironomidae. The secondary consumers such as Plecoptera and Trichoptera, and the burrowers, Ephemeridae and Odonata were collected less than the primary consumers. Generally the first dominant species belonged to Ephemeroptera such as Pseudocloeotz sp., Heptagenia sp., and Baetis sp, In four seasons Ephemeroptera appeared more abundantly in drift(62%) than benthic samplings(33%). Diptera occurred similarly in drift and benthic samplings at 22%. Plecoptera and Trichoptera were collected at 4% and 11%, respectively, and appeared less than in benthic samplings. In functional groups collectors and scrapers were collected more than shredders and predators in drifts. In habit groups clingers and swimmers were present more than sprawlers and burrowers.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.289-292
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• 2007

This research focuses on the relationship between participation characteristics on exercise needs of swimming participants. To this end, our research efforts questioned adult swimmers with increasing partner, time, determined factor of participation evinced higher levels of exercise needs. The research targeted the current(2006) membership of an aquatic facility operating in the Busan Gwangyeok-Shi, both male and female were selected as 299 participants of the study. This research utilized a exercise needs survey developed by Byung Gi Lee's team(1989). The data was analyzed through Reliability, Frequency and the ANOVA method. The results of this study are as follows: First, Those who regularly swim with a partners and those who swim alone showed differences in their exhibitionist tendency levels. Second, Those who scheduled their swimming activities in the evenings showed more motivation to exercise than those who swim in the mornings or afternoons. Third, Determining factors in beginning an aquatic exercise routine were quality of facilities or instructors, and these participants showed a different level of desire to reduce stress and exhibitionist tendency levels.

• Journal of Navigation and Port Research
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• v.27 no.5
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• pp.527-537
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• 2003

The characteristics of ship induced waves caused by navigation become widely different from both ship's speed and water depth condition. The ship induced waves specially generated in coastwise routes frequently give rise to call unforeseen danger for swimmers and small boats as well as shoreline erosion or sea wall destruction in coastal zones. The main concern of ship induced wave study until now is either how to reduce ship resistance or how to manoeuvre the ship safely under a constant water depth in the view point of shipbuilding engineers. Moreover, due to the trends for appearance of the high speed ships at the shallow coastal water, we are confronted with the danger of damages from those ship induced waves. Therefore, it is necessary to examine the development of ship induced waves and the influence of their deformation effects according to its propagation ray. In present study, in order to predict the development of the ship induced waves and their propagation under the conditions of complicate and variable shallow water depth with varying ship's speed, we constructed a computer model using Boussinesq equation with a fixed coordinate system and verified the model results by comparison with experimental results. Additionally, the model was applied under the variable water depth based on actual passage and we then confirmed the importance of the variable water depth consideration.

• Korean Journal of Community Nutrition
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• v.8 no.6
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• pp.951-963
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• 2003

The purpose of this study was to investigate the eating behaviors, the self-perception of body images, the hematological indices and the nutrient intake of adolescent female athletes in Incheon. The subjects were 112 female athletes(track and fleld: n=32, target shooting: n=27, fencing n=29, swimming: n=14, badminton: n=10) from middle and high schools in Incheon. This cross-sectional study was conducted by means of a sol(-administered questionnaire. Fasting blood samples were obtained and analyzed for hemoglobin (Hb), hematocrit (Hct), ferritin, serum iron, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration(MCHC), unsaturated iron binding capacity (UIBC), total iron binding capacity (TIBC) and transferrin saturation (TS). Nutrient intakes obtained by means of the 3 day-recall method were analyzed using the Computer Aided Nutritional Analysis Program. Statistical analysis was conducted using the SPSS 10.0 program. Most of the female athletes had dietary problems such as eating unbalanced meals, skipping meals, and preferences for processed foods. More than 60% of the female athletes skipped breakfast. As for perception of their body images, track and field athletes in particular, controlled their weights significantly better than the other athletes (p<0.05). With regard to their physical exertion during exercise, 56.3% of the swimmers and 31.3% of the track and field athletes answered “very hard”, which was a significant difference (p< 0.001). More than 80% of the female athletes experienced vertigo during exercise (p< 0.01). Also more than 50% of the female athletes, with the exception of the badminton players, had experienced irregular menstruation (p<0.05). The average serum iron levels (p<0.05), the serum ferritin levels (p<0.05) and TS (p<0.05) of the track and field athletes was significantly lower as compared to that of the other athletes. The nutrient intakes of the female athletes, with the exception of Vitamin B$_{6}$, niacin and phosphorus were lower than the Korean Recommended Daily Allowances (RDA). In particular, the calcium and iron intakes of the female athletes were under 50% of the Korean RDA. Therefore, proper nutritional education and supplementation are required for female athletes to encourage desirable eating habits, as well as to improve their nutritional status and exercise performances.s.