• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.3
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• pp.303-308
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• 2014

Aircraft are an indispensable mode of modern transportation. They are also used as in a wide variety of other fields. For example, aircraft are used for accommodating passengers, carrying freight, and for military reconnaissance. Aircraft ground operations include landing and taking off. During landing, a higher load is applied to the landing gear than during takeoff. The landing gear should absorb impact energy and prevent damage to the main body of the aircraft in the case of an accident. In this study, simulations were performed for two types of plate-spring-type landing gear: that made of composite materials and that constructed with aluminum. The structural safety of landing gear made of each material was also evaluated.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.23 no.1
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• pp.21-31
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• 2016

Purpose: This study is a qualitative research to identify new nurses' adaptation experience to sleep changes. Method: Grounded theory methodology was utilized. Participants were 10 new nurses from one university hospital. The information was collected and analyzed using the grounded theory of Corbin and Strauss'(2008). Results: Through constant comparative analysis, central phenomenon was identified as 'Shaky daily life due to the sleep change'. A core category emerged as 'In the shaky daily life, go grab my position', Causal conditions were 'Heaviness in shift work', 'Not released after getting off work', and 'Body and mind are exhausted'. Context were 'An environment that does not tolerate mistakes' and 'Clogged breathing due to worries'. Intervening factors were 'Support of colleagues', 'Recovery volition in restoration of altered relationships due to sleep'. Action/Interaction Strategies were 'To strive for a good sleep', 'Require a reasonable duty schedule' and 'Find a breakthrough'. Consequences were 'Become the master of shaky daily life' and 'Accepting the life of a nurse'. Conclusion: New nurses experience sleep patterns changes from the hospital shift system. but throughout the process of adaptation, came to accept sleep disorder as part of the life of a nurse.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.331-335
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• 2006

Theoretically, stable operations of an inlet are achieved at the design condition. However, at off-design conditions supersonic inlets often encounter the problem of aerodynamic instability, called inlet buzz. During inlet buzz, supersonic inlets exhibit considerable oscillation of the shock system in front of the inlet and corresponding large pressure fluctuations downstream. This phenomenon results in decrease of engine performance. An experimental and numerical study was conducted to investigate the phenomenon of supersonic inlet buzz on a generic, axisymmetric, external-compression inlet with a single-surface center-body. This study suggest that intermittent buzz exist and the frequency become to be large as increasing the back pressure.

• Particle and aerosol research
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• v.14 no.3
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• pp.73-80
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• 2018

Recently, there has been much research on the effect of ultrafine dust on human body with increasing interest in the ultrafine dust. In the Republic of Korea, there are many old thermal power plants, and the amount of ultrafine dust emitted from the thermal power plants is reported to be about 14% of the total amount of domestic fine dust. Therefore, the amount of fine dust from the flue gas desulfurization facility in the thermal power plant needs be reduced. In this study, we made an experimental setup to simulate a flue gas desulfurization facility and analyzed the physical characteristics of the particles passing through a mist eliminator. Experiments were carried out to investigate the collection efficiency of the mist eliminator by using the Arizona Test Dust in a dry environment, and then spraying limestone slurry into the flue gas desulfurization system equipped with the mist eliminator to examine the size and morphology of limestone particles upstream and downstream of the mist eliminator. Cut-off size of the mist eliminator was formed at about $6{\mu}m$. The result of this study is expected to be helpful for designing an electrostatic precipitator for removing particles passing through the mist eliminator.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.705-706
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• 2002

Hemodynamics of the TPLS(Twin Pulse Life Support System) is numerically investigated to delineate the possibility of hemolysis in blood. Computational method employing finite element algorithm is utilized to solve the blood flow of the sac squeezed by moving actuator. We assume that the blood flow interacts with the sac material which is activated by the rigid body motion of the actuator. Valve dynamics at the ends of the sac is simplified as on/off type motion. We compute the transient viscous flow in the two-dimensional geometry of the blood sac. Incompressible laminar flow is simulated on the assumption of Newtonian fluid. Blood velocity has a step gradient near the throat of the sac formed by the moving actuator. According to the decrease of the gap size of blood passage, the magnitude of shear stress in the blood is dramatically increased. Numerical solutions show that the maximum value of shear stress in the blood flow in TPLS is relatively smaller than that of the roller type ECLS.

• Journal of Mushroom
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• v.12 no.2
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• pp.77-81
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• 2014

Mushrooms are considered not only as food but also for source of physiologically beneficial medicines. The culinary-medicinal mushrooms may important role in the prevention of age-associated neurological dysfunctions, including Alzheimer's and Parkinson's diseases. Hericium erinaceus (H. erinaceus), is edible mushrooms, is a parasitic fungus that grows hanging off of logs and trees and well established candidate for brain and nerve health. H. erinaceus contains high amounts of antioxidants, beta-glucan, polysaccharides and a potent catalyst for brain tissue regeneration and helps to improve memory and cognitive functions. Its fruiting bodies and the fungal mycelia exhibit various pharmacological activities, including the enhancement of the immune system, antitumor, hypoglycemic and anti-aging properties. H. erinaceus stimulates the synthesis of Nerve Growth Factor (NGF) which is the primary protein nutrient responsible for enhancing and repairing neurological disorders. Especially hericenones and erinacines isolated from its fruitin body stimulate NGF, synthesis. This fungus is also utilized to regulate blood levels of glucose, triglycerides and cholesterol. H. erinaceus can be considered as useful therapeutic agents in the management and/or treatment of neurodegeneration diseases. However, this review focuses on in vitro, in vivo and clinical trials for neurodegerative disease.

• Korean Journal of Applied Biomechanics
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• v.24 no.4
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• pp.317-327
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• 2014

As a single subject study, it was purposed to investigate kinematic differences between Yang Hak Seon vault (i.e., handspring forward and salto forward straight with triple twist, Yang-1 vault hereafter) and Tsukahara $1260^{\circ}$ twist with salto forward straight (Yang-2 vault hereafter) in gymnastics. Yang Hak-Seon (23 years, 160 cm, and 52 kg) voluntarily participated in this study. Motion capture system, consisting of fourteen cameras, were used to measure Yang-2 vault with the sampling rate of 200 Hz. Twenty six reflective markers were placed on major anatomical points of 15 body segments. Successful two trials of Yang-2 vault were collected and analyzed for the comparison. Compared Yang-1 results were based on the previous study of Park and Song (2012). Results indicated superior linear kinematics of Yang-1 vault to those of Yang-2 vault before the touchdown of vault table. However, Yang-2 vault revealed superior angular kinematics to Yang 1 vault showing more trunk twist angle (a triple and a half twist) and its faster angular velocity during the airborne. The Yang 2 vault could has advantage of increasing angular motion than Yang 1 vault as a result of a half turn off the springboard onto the vault table and a sequential touchdown of the hands.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.5 s.170
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• pp.113-120
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• 2005

Because of the turbulent markets and the increasing demand on product quality, the application of new technology to practice is increasingly important. In case of automotive industries, they take interest in laser welding to solve these problems because laser welding has many advantages such as good accessibility, welding quality, fast welding speed and so on. To apply this technology to welding of car body, the data of laser welding are collected through lots of the experiment according to the material, geometry and layer number of welding points. Based on the experiment results and the information of product, i.e. the car side panel, the clustering of stitches for laser welding was carried out and the optimal equipments are selected through the comparison between the requirements of welding and the potential of equipments. Using these results, laser welding cell for the car side panel are configured with the concept of the digital manufacturing, which ensures maximum planning security with visualization and simulation. Finally, the optimal laser welding cell is chosen by the evaluation of alternative cells with assessment criteria.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.3
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• pp.47-52
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• 2021

Fine dust generated from vehicle brakes accounts for a significant amount of fine dust from non-exhaust system. Since such brake fine dust contains a large number of heavy metal components that are fatal to the human body, a device capable of collecting them needs to be developed. A mini cyclone, one of the devices that can effectively collect fine dust, has the advantage of relatively simple shape and high collection efficiency. Therefore, in this study, the collection efficiency of the mini-cyclone was numerically analyzed using CFD in order to find out whether such a mini-cyclone is suitable for collecting brake fine dust. As a result, the cut-off diameter was predicted to be about 1.5㎛, which means that the particle trapping load of the filter can be drastically reduced. Therefore, there is a possibility that the mini-cyclone can be used to collect fine dust from disc brakes.

• Journal of the Korea Fashion and Costume Design Association
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• v.26 no.2
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• pp.101-114
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• 2024

Currently, in Korea, the number of handicapped children receiving inclusive education in general schools is expanding. In the inclusive education field, the most important tasks are personal needs support, such as toilet assistance, meal assitance, and support for wearing and taking off various assistive devices. A significant portion of the support work in the actual education field is related to clothing. Therefore, it is necessary to research and develop universal fashion designs for handicapped children at school where inclusive education is implemented. To achieve this aim, this study analyzed the concepts, principles and, characteristics of universal fashion design through theoretical research and established research principles. In this study, two fact-finding surveys were conducted. Next, a total of 10 universal fashion designs were proposed considering both the preceding survey results and the principles of universal fashion design Among them, the four designs that were considered most suitable were selected for universal fashion design through F.G.I (Focus Group Interview) analysis conducted by experts. The four selected designs were made by referring to the size framework based on the '6th Human Body Size Survey Report of Korea'. The completed experimental clothes were proposed as the final universal fashion design for handicapped children by conducting external evaluation through a virtual clothing system and real clothes.