• Proceedings of the KIEE Conference
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• 2005.11c
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• pp.56-59
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• 2005

In this paper, electrical risk factors due to the powered recovery equipments thrown to escape the dangerous condition that electrical apparatuses were submerged were derived and analyzed. After surveying several underground flooding sites, we could find out the status quo of the underground electrical equipments and what the most dangerous factors to a human body under water were. The results acquired from this study are applying to safely assessment algorithm.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.4
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• pp.63-69
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• 2011

Hull forms for catamaran type small fishing boat powered by electric motor are newly developed by experimental approaches. Model tests for two hull forms having different length are made at circulating water channel. Resistance performance and wave patterns are compared to carry out an analysis of the effect of extension of main body. The results show that the extension of main body can give better resistance performance above a certain velocity.

• Membrane Journal
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• v.33 no.6
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• pp.398-408
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• 2023

This work developed a hood and filter for antibacterial protective clothing for medical powered air purifying respirators (PAPR) that can be used in medical settings and quarantine against infectious diseases such as Zika virus, Middle East respiratory syndrome (MERS), and coronavirus disease-19 (COVID-19). The hood material of the protective clothing was made of polypropylene spunlace nonwoven fabric (SFS) was used for withstand wind pressure and external physcial pressure. Forthermore, in order to reduce the user's risk of infection, phytoncide-based materials were used on the outer-surface of the hood to achieve a 99.9% antibacterial effect, and the inner-surface were treated with hydro-philic materials to improve absorbency by 25%. In addition to evaluating the artificial blood penetration resistance, dry mi-croorganism penetration resistance, wet bacteria penetration resistance, and bacteriophage penetration resistance required for medical protective clothing hoods, it received a passing evaluation of levels 2-6. Meanwhile, as a result of evaluating the performance of the antibacterial treated spunlace high efficiency particulate air (HEPA) filter, excellent antibacterial properties, dust removal rate, and differential pressure effect were confirmed. All performance evaluations were conducted by an accredited certification body in accordance with the medical PAPR certification standards.

• The Korea Journal of Herbology
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• v.22 no.4
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• pp.127-135
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• 2007

Objectives : In this study we investigated the antiobese effects of mixed pills of pickled black soybeans with herbs(herbal Chokong pill, hereafter HCKP) in rats fed high-fat diet. It was evaluated by measuring the changes of body weight, adipose tissues weight and lipid profiles in serum. Methods : Black soybeans were pickled in vinegar for 15 days to prepare Chokong, at room temperature. For treatment group, HCKP was prepared, which five kinds of medicinal herbs(Rhynchosia nulubilis, Glycyrrhiza uralensis, Zizyphus vulgaris, Atractylodes macrocephala K, Astragalus membranaceus and Cornus officinalis) were added to dried Chokong. Four groups of male Sprague-Dawley rats were fed different diets during 9 weeks: normal diet containing 5%(w/w) com oil, high-fat diet containing 10%(w/w) lard plus 5%(w/w) corn oil (HF), high-fat diet supplemented with 1%(T1) and 5%(T5) HCKP powder, respectively. Results : The T5 group had markedly lower body weight gain and weights of epididymal adipose tissue when compared with HF group. There were significant differences in visceral adipose tissue weights, serum total cholesterol and triglyceride concentrations between the HF and T5 group. Then, the efficacy of powered HCKP on body weight and lipid profiles change in rats fed high-fat diet were induced dose dependantly. Conclusion : These results suggest that the possibility of HCKP, as an antiobese functional formula, by suppression of body weight gain and improved lipid profiles.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.1
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• pp.70-75
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• 2003

There come various types of robot with researches for mobile robot. This paper introduces the multi-joint snake robot having 16 degree of freedom and composing of eight-axis. The biological snake robot uses the forward movement friction and the proposed artificial snake robot uses the un-powered wheel instead of the body of snake. To determine the enable joint angle of each joint, the controller inputs are considered such as color and distance using PC Camera and ultra-sonic sensor module, respectively. The movement method of snake robot is sequential moving from head to tail through body. The target for movement direction is decided by a certain article be displayed in the PC Camera. In moving toward that target, if there is any obstacle then the snake robot can avoid by itself. In this paper, we show the method of snake robot for tracing the target with experiment.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.604-609
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• 2002

In development of an advanced bicycle simulator, the investigation of the interactions between bicycle and rider during cycling is paramount important because bicycle is a two-wheeled human-powered vehicle. Tn this work, the tilt stability. among various interactions, of bicycling is investigated experimentally, In the experiments, the tilt angles of the bicycle, riders body and head are measured, as the riding p;1th and the speed are varied. Subjects are asked to ride along four typical paths on rigid flat ground : the straight, C-curved, S-curved and circle paths. The results from extensive experiments with different subjects can be summarized as : 1) The tilt angles of bicycle and rider are almost out of phase during pedaling along the straight path. 2) The bicycle tilt angle is nearly proportional to the square of bicycle speed for the straight and curved paths, and to the curvature for the curved paths. The head tilt angle is the biggest and the body tilt angle is the smallest for the straight path, but the tendency is reversed for the C-curved path. During the curve maneuvering, the rider's head tends to tilt by less than 40% of the bicycle tilt angle.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.9
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• pp.97-103
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• 2021

In this paper, an omni wheel-based electric wheelchair is proposed that can achieve safe and convenient movement and can improve the convenience of living for mobility-impaired people who cannot move on their own. Generally, mobility-impaired people are afflicted with physical health issues such as pain and secondary body deformities because they often remain seated in wheelchairs for long periods of time. Hence, an electric wheelchair is required whose posture can be changed and whose size can be adjusted according to the user's body type. Such a wheelchair should also facilitate easy change of direction (even in a narrow space) for convenient movement. In this paper, an electric wheelchair featuring omni wheels is proposed that allows posture transformation and facilitates movement in a narrow space. It is believed that the proposed wheelchair can aid in enhancing the convenience of living for mobility-impaired people.

• Journal of IKEEE
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• v.21 no.1
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• pp.66-69
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• 2017

In recent year, energy harvesting technologies from the ambient environments such as light, motion, wireless waves, and temperature again a lot of attraction form research community [1-5] due to its efficient solution in order to substitute for conventional power delivery methods, especially in wearable together with on-body applications. The drawbacks of battery-powered characteristic used in commodity applications lead to self-powered, long-lifetime circuit design. Thermoelectric generator, a solid-state sensor, is useful compared to the harvesting devices in order to enable self-sustained low-power applications. TEG based on the Seebeck effect is utilized to transfer thermal energy which is available with a temperature gradient into useful electrical energy. Depending on the temperature difference between two sides, amount of output power will be proportionally delivered. In this work, we illustrated a low-input voltage energy harvesting circuit applied discontinuous conduction mode (DCM) method for getting an adequate amount of energy from thermoelectric generator (TEG) for a specific wearable application. With a small temperature gradient harvested from human skin, the input voltage from the transducer is as low as 60mV, the proposed circuit, fabricated in a $0.6{\mu}m$ CMOS process, is capable of generating a regulated output voltage of 4.2V with an output power reaching to $40{\mu}W$. The proposed circuit is useful for powering energy to battery-less systems, such as wearable application devices.

• Fashion & Textile Research Journal
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• v.26 no.1
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• pp.123-136
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• 2024

This study aimed to assess the mobility and thermal comfort of personal protective equipment (PPE) among female healthcare workers, taking into account wearers' physique and PPE protection levels. A total of 16 participants (age: 26.3 ± 8.3 y, height: 161.5 ± 7.3 cm, body weight: 57.1 ± 11.0 kg, BMI: 21.9 ± 3.6), representing diverse body types, underwent four PPE conditions: L (Low_Plastic gown ensemble), M (Medium_Tyvek 400), H (High_Tyvek 800J with Powered Air Purifying Respirator [PAPR]), and E (Extremely high_Tychem 2000 with PAPR, Bib apron, and Chemical-resistant gloves). The mobility protocol consisted of 10 different tasks in addition to donning and doffing. The 10 tasks were repeated twice at an air temperature of 24.3 ± 0.1℃, 59±4%RH. Findings revealed a disproportionate relationship between PPE protection and wearer discomfort. Significant differences in clothing microclimate and total sweat rate were observed between the lowest (L) and highest (E) protection levels (p < 0.01), while distinctions among medium levels were inconclusive. Subjective evaluations favored conditions H and L over M and E (p < 0.05), indicating reduced heat, and humidity, increased comfort, and lower exertion. Instances of mobility discomfort, specially in the small body type group, underscored the need for a suitable PPE size system for Korean adult female medical workers. Furthermore, enhancements in gloves, shoe cover, and PAPR hood designs are essential for improving ease of movement and preventing hindrance.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2002.04a
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• pp.41-42
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• 2002

The powered missiles with very high thrust level can make highly underexpanded jet plume downstream of tile exhaust nozzle exit so that strong interactions between the exhaust plume and a free stream occur around the body at transonic or supersonic speeds. The interactions result in extremely complicated flow phenomena, which consist of plume-induced boundary layer separation, strong shear layers, various shock waves, and interactions among these. The flow characteristics are inherent nonlinear and severe unstable during the flight at its normal speed as well as taking-off and landing. Eventually, the induced boundary layer separation and pitching and yawing moments by the interactions cause undesirable effects ell the static stability and control of a missile.