• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.47 no.11
• /
• pp.803-811
• /
• 2019

Water rocket is a non-chemical rocket mechanically powered by pressurized gas and liquid (water) propellants. Since water rockets share many engineering commonalities with liquid propellant rockets for space launch vehicles, it is as a education tool for rocket engineering. Present paper investigated the availability of water rocket as an engineering education model by surveying the history of water rocket and making examples from K-12 education, commercial products and club activities. Finally, a way of improvement is suggested for water rocket competitions make changes in the perception on water rockets by examining the limitations of present competitions.

• Journal of Life Science
• /
• v.20 no.2
• /
• pp.314-320
• /
• 2010

As the nature of triathlons is competition in three successive sports, triathletes experience elevated levels of stress on the body that are absent in single-sport athletic events, and consequently there are more potential medical problems to prepare for. Triathletes can also experience problems such as hypothermia, heat illness, excessive exposure to ultraviolet radiation, musculoskeletal injuries and trauma, immunosuppression, and haemolysis. Depending on the potentiality of such above-listed problems occurring in any given race, race organizers will prepare preventative measures and treatments accordingly. Olympic distance is not the only triathlon racing distance. Sprints, which are normally around half the Olympic distance, are common distances, as well as Long (2 km swim, 80 km bike, 20 km run), Ironman (3.8 km swim, 180 km bike, 42 km run), and ultra-distance events varying in length. Races of longer duration normally result in a higher percentage of athletes experiencing the above-mentioned medical problems, as well as inducing additional health risks such as hyponatraemia. Minimizing the occurrences of serious health issues is possible through the following means: carefully preparing for the probable race-day weather conditions; proper management and organization of the race; preparing an extensive water-safety and ground-course safety plan; distributing necessary nutrition along the course; and stressing the importance for athletes to have proper knowledge concerning race nutrition, biomechanical technique, physical preparation, and utilization of safe equipment. While risks of competing in triathlon are many, the instances of such medical problems are not excessive, and the triathlon has a reputation of being a reasonably safe sport as long as athletes with high risk take added precautions.

• Journal of Korea Entertainment Industry Association
• /
• v.13 no.1
• /
• pp.111-119
• /
• 2019

The purpose of study was to evaluate the economic evaluation of Chuncheon curling stadium. In oder to estimate economic evaluation, benefit/cost ratio, net present value and internal rate of return were used. Additionally, in order to investigate the socio-economic spread effect, literature review and input-output analysis were used. The results of study were as follows. First, as a result of analyzing the demand for curling stadiums in Chuncheon, it was believed that the construction of the stadium will attract athletes from the Chuncheon region as well as athletes from Seoul, Incheon, Gyeonggi Province and North Chungcheong Province. Second, economic validity analysis showed that the initial investment did not make sense, but the players' training and competitions and the advantages of the potential experience of curling events for citizens in nearby areas, including Chuncheon, make the construction and operation reasonable. Third, as a result of the review of the social and policy validity of the curling stadium, the project to build a curling stadium in Chuncheon was secured with a policy validity as a public sports facility necessary for both professional and living athletes. Finally, the analysis of socio-economic spread effect of curling stadiums had shown that it would have a positive effect on the level of satisfaction of the general public as well as the discovery of elite athletes.