• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2419-2421
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• 2008

Some of the scallops like Amesium balloti have an excellent level-swimming ability, i.e. they can swim about 20m by single level swimming with a maximum swimming velocity of about 1.6m/s in the sea. On the other hand, some species like Patinopecten yessoensis have longitudinal grooves on the upper and lower surfaces and others do not. Therefore, in the present study, we measure the lift and drag forces on a real scallop model (Patinopecten yessoensis) in a wind tunnel. Experiments are performed at the Reynolds number of 75,000 based on the maximum chord length, which is within the swimming condition of real scallop (Re = $30,000{\sim}300,000$). To see the effect of longitudinal grooves, we measure the aerodynamic forces on a scallop model by removing the grooves. With the grooves, the lift force increases at low angles of attack (${\alpha}<10^{\circ}$). The drag force increases slightly at all the attack angles considered. The lift-to-drag ratio is increased by about 10% at ${\alpha}<10^{\circ}$.

• Journal of Korea Water Resources Association
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• v.41 no.4
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• pp.423-432
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• 2008

The local migration or movement behavior of fishes in streams are related to feeding, spawning, growing, dispersing, and refuging. The pale chub (Zacco platypus) is a dominant species that migrates locally and inhabits in river and stream in Korea. However, dams, weirs, culverts and other regulatory structures are physical barriers that limit fish movement and fragment habits and populations. If main stream and off-channel habitats are connected with culverts, they would restrict the small fish as pale chub movement due to the high flow velocities and low depths. But in Korea, there is no experimental study to evaluate the swimming performance of species in Korea. Therefore, it is difficult to proposed that design guidelines for pass fishes through culverts. The purpose of this experimental study is to evaluate the swimming performance of pale chubs. A series of swimming performance test has been used in both of the fixed velocity and the incremental velocity methods in an experimental flume. As a result, the critical swimming speed for pale chub(body length 8.9 cm) was found to be about 0.7 m/s. Therefore, the flow velocity for culvert design in the low flow condition should not be exceed the its swimming ability, especially 0.7 m/s for pale chubs(body length 8.9 cm). And the minimum depth for culvert design in the low flow condition should not be lower than the fish body height add a dorsal fin height.

• The Korea Journal of Herbology
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• v.22 no.2
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• pp.127-135
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• 2007

Objective : Investigation of the anti-stress effects of Sihosogansan Methods : Passive avoidance test(PAT) was performed after applying immobilization stress in water to rats. Also, forced swimming test(FST) was performed to another rats and after FST, the degree of Tyrosine Hydroxylase(TH) expression was measured with immunohistochemical method in the regions of locus coeruleus(LC) and ventral tegmental area (VTA). Results : In the PAT after immobilization stress in water, response latency was significantly increased in the Sihosogansan(400mg/kg) group in comparison with the control group. In the FST, immobility was significantly decreased in the Sihosogansan groups (100mg/kg, 400mg/kg), comparing with the control group. Stress-induced TH increases were suppressed in the Sihosogansan groups (100mg/kg, 400mg/kg) at the LC and the VTA region respectively. Conclusion : Sihosogansan can improve memory ability of rats, reduce behavior of depression in rats, decrease TH-immunoreactive cells at the LC and VTA region in rat, and it may be concluded that Sihosogansan has significant effect in reducing stress.

• Journal of Life Science
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• v.17 no.10
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• pp.1400-1405
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• 2007

The effect of supplementation with docosahexaenoic acid into n-3 fatty acid deficient diet on improvement of loaming related brain function was investigated. On the second day after conception, Sprague Dawley strain dams were subjected to a diet containing either n-3 fatty acid deficient (Def) or n-3 fatty acid deficient + docosahexaenoic acid (Def+DHA). After weaning, male pups were fed on the same diet of their respective dams until adulthood. Motor activity and Morris water maze tests were measured at 10 weeks old. In motor activity test, there were no statistically significant differences in moving time and moving distance between the Def and Def+DHA diet groups. The n-3 fatty acid deficient with DHA (Def+DHA) group exhibited a shorter escape latency, swimming time and swimming distance (P<0.05) compared to the n-3 fatty acid deficient group (Def) but there was no difference in resting time and swimming speed between the experimental diet groups. In memory retention trial, the number of crossing of the platform position (region A) was significantly greater than those of other regions for the Def+DHA group. However, the Def group swam randomly without preference for the provisions platform location, indicating poorer memory retention. From those results, supplementation with DHA into the n-3 fatty acid deficient diet improved the spatial loaming ability in rats as assessed by Morris water maze test.

• Korean Journal of Ichthyology
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• v.30 no.1
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• pp.9-17
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• 2018

This study investigated how the larvae of three winter-spawning fishes are adapted in a cold water environment by examining the morphology, digestive system, and swimming ability of larvae from three winter-spawning species (Gadus macrocephalus, Liparis tanakae, Hexagrammos agrammus). Data were collected at hatching and first feeding. The results were compared with repored data on several non-winter-spawning species. Mean total lengths at hatching (${\pm}SD$) were $4.35{\pm}0.11mm$, $5.26{\pm}0.08mm$, and $7.48{\pm}0.35mm$ for G. macrocephalus, L. tanakae, and H. agrammus, respectively. Three winter-spawning fishes had well-developed digestive tracts after hatching than those of non-winter-spawning fish larvae. Yolks were intact until 5 days post-hatching in all three species, indicating that they had longer mixed-feeding periods compared with fishes spawned during other seasons. G. macrocephalus, L. tanakae, and H. agrammus larvae had superior cruise and burst speeds (measures of swimming ability) than non-winter-spawning larvae. We conclude that the unique characteristics of these three winter-spawning species are naturally selected adaptations under lower water temperature in winter.

• Journal of Digital Convergence
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• v.14 no.5
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• pp.427-432
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• 2016

The purpose of this study was to investigate drowning death patients on clinical care and prevention. Drowning accidents that occurred in the Republic of Korea were identified by using the Emergency Activity Daily Report Data from the National Emergency Management Agency (NEMA). The age of drowning accidents was 20-29 years (25.4%). Drowning cases for the months of August was 17.6%. The main circumstance involved in the drowning cases was swimming (45.0%). Half of swimming incidents related the drowning accidents of people attempting to save a life of a family member or friend from the water. The most common location was at a lake or reservoir (40.2%). Drowning is a main cause of accidents in the Republic of Korea. Preventive strategies that may be beneficial for persons contain life jackets or life rings supply, upgrading swimming ability, placing lifeguards based on public education activities.

• The Journal of Internal Korean Medicine
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• v.40 no.6
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• pp.1136-1144
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• 2019

Objective: Physical inactivity contributes to mortality rates and is now the fourth most frequent cause of death worldwide. Red ginseng is a medicinal herb that is often used as an ergogenic aid. In this study, red ginseng was administered to rats to test whether it affected their ability to exercise. Methods: Forty-five rats were randomly distributed and divided into five groups: normal (N, n=5), control (C, n=10), the group to which only red ginseng was administered (H, n=10), the group to which only amino acid complex was administered (A, n=10), and the group to which both red ginseng and amino acid complex were administered (HA, n=10). Once a day for three weeks, 333.3 mg/kg body weight per day (b.w./day) of red ginseng and 750 mg/kg b.w./day of amino acid preparation were administered to rats. After three weeks, body weight, swimming time, and the weight of the anterior tibialis muscle of rat were measured. Blood was taken for analysis using the cardiac puncture method. Results: The swimming time of group H (921.3±199.26 sec) showed significant improvement compared to that of group C (798.48±156.37 sec) (p<0.05). Conclusion: Red ginseng has improved swimming time in rat and can be used as an effective ergogenic aid.

• Ecology and Resilient Infrastructure
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• v.8 no.1
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• pp.9-21
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• 2021

In this study, fish and flow surveys were conducted at 12 survey points to calculate the fish habitat suitability index of Miho Stream in the Geum River Water System. The field surveys were conducted four times from September 2019 to May 2020. The results show the presence of 8 families, 37 species, and 5,754 individuals. The number of water purification species that preferred waters with a low flow rate was the highest. The habitat suitability index was calculated according to the Washington Department of Fish and Wildlife method based on the populations collected at various water depths and flow rate sections and the flow rate survey results. For the dominant species, Zacco platypus and swimming species, the results were compared by calculating at Gasan Bridge and Palgye Bridge at the upper stream. The single species showed no significant difference between the upstream and downstream at water depths of 0.1 - 0.5 m and flow rates of 0.2 - 0.5 m/s. The species swimming ability was similarly calculated at water depths of 0.2 - 0.5 m and flow rates of 0.2 - 0.5 m/s. The dominant species, Pyramid, had a wide range of physical habitats. The habitat suitability index between the swimming species was similarly calculated. These results can be effectively used as basic data for calculating the environmental ecological flow rate and establishing a river restoration plan of the Miho Stream.

• Korean Journal of Ichthyology
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• v.31 no.1
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• pp.7-15
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• 2019

The present study aimed to investigate the influence of starvation on growth, survival and swimming ability of Pacific cod Gadus macrocephalus larvae. Notochord length, musculature height, body depth, gut height and volume of yolk of reared larvae were measured to determine the growth parameters. A significant difference was observed in all morphometric characteristics before 15 DAH (days after hatching). Body depth and volume of yolk of unfed larvae were significantly smaller than those of fed larvae from 9 DAH (P<0.05). Almost all yolk in fed group was consumed at 11 DAH. Survival and growth of larvae were observed to determine the effect of delayed initial feeding (2 DAH, 3 DAH, 4 DAH, unfed). All larvae in the unfed group died by 15 DAH and the larvae in other experimental groups survived until the end of the experiment to 21 DAH. Survival rate was not significantly different between the 2 DAH group ($17.5{\pm}4.27%$) and the 3 DAH group ($20.5{\pm}1.5%$) at 21 DAH (P>0.05). However, there was a significant difference in survival rate between the 3 DAH group and the 4 DAH group ($11.7{\pm}1.52%$) (P<0.05). There was no significant difference in notochord length among the groups fed from 2 DAH, 3 DAH and 4 DAH at 21 DAH (P>0.05). The swimming ability in fed group gradually increased in both cruising and burst swimming speeds, while those abilities in unfed group gradually decreased after reaching the peak at 6 DAH in both cruise ($18.7{\pm}6.56mm/s$) and burst swimming speed ($43.5{\pm}12.65mm/s$).

• Korean Institute of Interior Design Journal
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• v.21 no.1
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• pp.269-279
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• 2012

According to a progress in the quality of life and economy, recent years have seen an increase in interest in the cruise travel. However, it is important to provide them the optimum embarkation environment since there are to be many and unspecified persons staying for a long period on the cruise ship. In the architectural design field, a wide range of efforts are being recently made to meet customer's requirements by considering the rapidly changing society, environment, and economic trend. The most representative one of such efforts is the inclusive design concept. This concept means to perform design satisfying all the function, convenience, aesthetic appreciation, and utility, regardless of sex, age, ability, nationality, cultural background or any kinds of disabilities. Regarding this trend, the convenience-oriented design of a cruise ship using the inclusive design concept was performed in this study. To do this, the composition of cabins and swimming pools, and the exterior of the cruise ship were classified into several groups through literature survey. Then, in the point of view of the inclusive design concept, inconvenience matters of passengers about the cabins, swimming pools, and exterior were also extracted from literature survey. Next, basis designs for them were selected among the classified groups in order to solve such inconvenience matters. Finally, the convenience-oriented design of the Emerald Princess Cruise considering the inclusive design concept was performed by applying the basis designs. As a result, we can see that the inclusive design concept can be applied to cruise ship design.