• 대한물리의학회지
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• 제12권3호
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• pp.67-71
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• 2017

PURPOSE: Muscle fatigue is a cause to change proprioception. The purpose of this study was to investigate the effects of calf muscle fatigue and visual control on postural balance during single-legged standing in healthy adults. METHODS: Nineteen healthy adults (male) were participated in this study (mean age: 24.36 years; mean height: 171.32 cm; mean weight: 64.58 kg). The postural balance (sway length, sway area, sway velocity of COG displacement) was measured by Balance Trainer System (BT4) in before and after calf muscle fatigue feeling in single legged stance. In this study, repetitive single-legged heel rise test was used to induce fatigue of the calf muscle. Paired t- test was used to compare the postural balance between before and after calf muscle fatigue. Data of subjects were analyzed using SPSS 22.0 (SPSS Inc., Chicago, IL, USA). Level of significance was set to .05. RESULTS: The sway length, sway area, sway velocity of COG (center of gravity) displacement after calf muscle fatigue feeling was significantly increased compared to before calf muscle fatigue feeling during single leg standing both eye open and close conditions (p<.05). CONCLUSION: This study suggested that calf muscle fatigue feeling has affected on postural balance when standing one leg both eye open and close conditions and postural control was disturbed by muscle fatigue and visual feedback in single leg standing.

• 대한기계학회논문집
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• 제15권1호
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• pp.61-68
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• 1991

본 연구에서는 스프링힌지, 클램프, 단순지지, 탄성지반, 다수의 병진 및 회 전스프링 그리고 중간지지점의 조합으로 구성되어 있는 보에 대하여 우선 Hamilton원 리에 의하여 정확한 보의 특성방정식을 유도하고 모든 경계조건을 만족하는 직교다항 식을 구한 후, 스프링, 댐퍼로 구성된 여러개의 질량이 일정한 속도로 이동할 경우에 대하여 Galerkin방법과 수치적분 방법을 사용하여 동적응답을 구하였다. 또한 구속 조건 및 경계조건이 변함에 따라 동적응답에 미치는 영향을 연구하였다.

• 대한교통학회지
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• 제9권2호
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• pp.135-144
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• 1991

In recent years parking problems have been rapidly highlighted. Particularly on-street parking has become a very serious problem so an immediate action needs to be taken to resolve this problem. On-steet parking is attributable not only to insufficient capacity of parking lots but also to the facts that must of the parking lots are far away from the destinations to which drivers intend to go and that their locations are unclear. The effect of on-street parking is so great as to cause road traffic problems such as traffic jam and danger to road safety as well as to lead to obstructing business activities resulting in a decline of commercial areas. Therefore on-street parking is an important problem for a city as a whole. In this paper I have investigated a parking lot information and guiding system as one of the techniques to resolve the on-street parking problem and have clarified the effect of introducing this system and necessary conditions for implementing an optimum information and guiding system. Moreover I have pointed out the problems to be encountered in imp-lementing such system in areas not equipped with infrastructures taking into account the road conditions in these areas and have stated that it would be necessary to develop a new idea of information and guiding system in order to overcome these problems. I have suggested a Shot Gun Method as a proposal and have discussed extensibility of this method in the future.

• Ocean Science Journal
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• 제41권4호
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• pp.235-244
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• 2006

Determining 'photosynthetically active radiation' (PAR) is a key part of calculating phytoplankton productivity in a biogeochemical model. We explore the daily and seasonal variability in the ratio of PAR irradiance to total irradiance that occurred at Ieodo Ocean Research Station (IORS) in the East China Sea under clear-sky conditions in 2004 using a simple radiative transfer model (RTM). Meteorological data observed at IORS and aerosol optical properties derived from Aerosol Robotic Network observations at Gosan are used for the RTM. Preliminary results suggest that the use of simple PAR irradiance-ratio values is appropriate in calculating phytoplankton productivity as follows: an average of $0.44\;({\pm}0.01)$ in January to an average of $0.48\;({\pm}0.01)$ in July, with average daily variabilities over these periods of about $0.016\;({\pm}0.008)$ and $0.025\;({\pm}0.008)$, respectively. The model experiments demonstrate that variations in the major controlling input parameters (i.e. solar zenith angle, precipitable water vapor and aerosol optical thickness) cause PAR irradiance ratio variation at daily and seasonal timescales. Further, increases (>0.012) in the PAR irradiance ratio just below the sea-surface are positively correlated with high solar zenith angles and strong wind stresses relative to those just above the sea-surface.

• 한국유체기계학회 논문집
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• 제7권2호
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• pp.41-49
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• 2004

Condition monitoring is very important in turbo machinery because single failure could cause critical damages to its plant. So, automatic fault recognition has been one of the main research topics in condition monitoring area. We have used a relatively new fault recognition method, Hidden Markov Model(HMM), for mechanical system. It has been widely used in speech recognition, however, its application to fault recognition of mechanical signal has been very limited despite its good potential. In this paper, discrete HMM(DHMM) was used to recognize the faults of rotor system to study its fault recognition ability. We set up a rotor kit under unbalance and oil whirl conditions and sampled vibration signals of two failure conditions. DHMMS of each failure condition were trained using sampled signals. Next, we changed the setup and the rotating speed of the rotor kit. We sampled vibration signals and each DHMM was applied to these sampled data. It was found that DHMMs trained by data of one rotating speed have shown good fault recognition ability in spite of lack of training data, but DHMMs trained by data of four different rotating speeds have shown better robustness.

• 대한조선학회 특별논문집
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• 대한조선학회 2009년도 특별논문집
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• pp.123-129
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• 2009

Ship painting procedures can be divided into two categories; Out-shell plate painting of the hull and the interior painting of each double gull blocks. It is really hard to apply standardized and automated operations to the latter because the double hull blocks contains a variety of complicated supportive materials and pipes to strengthen the ship structure. In addition their poor working conditions cause painting workers to avoid working in them, resulting in the waste of paints and additional pollution issues. So this research, successfully focused on overcoming the difficulties in working in the complicated blocks and the tough working conditions introduces the main details of automatic equipment systems and their transfer algorism which show how the equipment paints the inner sides of a longitudinal stiffener and moves to another automatically.

• 대한치과의사협회지
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• 제48권9호
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• pp.688-695
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• 2010

Burning mouth disorders (sometimes referred to as burning mouth syndrome) are characterized by a burning sensation in the tongue or other oral sites, usually in the absence of clinical and laboratory findings. Affected patients often present with multiple oral complaints, including burning, dryness and taste alterations. Burning mouth complaints are reported more often in women, especially after menopause. Typically, patients awaken without pain, but report increasing symptoms through the day and into the evening. Conditions that have been reported in association with burning mouth syndrome include chronic anxiety or depression, various nutritional deficiencies, diabetes and changes in salivary function. However, these conditions have not been consistently linked with the syndrome, and their treatment has had little impact on burning mouth symptoms. Recent studies have pointed to dysfunction of several cranial nerves associated with taste sensation as a possible cause of burning mouth disorders. The most common central mechanism that likely explains burning mouth disorders is a centrally mediated continuous neuropathic pain. Given in low dosages, benzodiazepine, tricyclic antidepressants or anticonvulsants may be effective in patients with burning mouth disorders.

• Archives of Reconstructive Microsurgery
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• 제15권2호
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• pp.111-116
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• 2006

An infection after total knee arthroplasty has many complications such as severe bone defect, skin and soft tissue problems, devastated general condition, so arthrodesis is preferred as treatment option. However, poor bony contact due to severe bone defect and inadequate conditions of the soft tissue often cause nonunion or severe limb shortening after arthrodesis. More over these conditions, it is not easy to choose appropriate fixative devices. In these situations, the arthrodesis using vascularized fibular graft can be the solution. Vascularized fibular graft (VFG) can playa role as a suitable material for the treatment of bone defects. And VFG can overcome poor blood circulation caused by scar tissues, and can be relatively more durable and adequate length. In the long term, VFG can be hypertrophied by weight bearing, and will give mechanical stablility. The purpose of the paper is to report the successful results of arthrodesis using VFG in a patient who got extensive bone defect after failed revision total knee arthroplasty with infection.

• 한국안전학회지
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• 제21권3호
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• pp.45-52
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• 2006

The AITs(autoignition temperatures) describe the minimum temperature to which a substance must be heated, without the application of a flame or spark, which will cause that substance to ignite. The AITs are often used as a factor in determining the upper temperature limit for processing operations and conditions for handling, storage and transportation, and in determining potential fire hazard from accidental contact with hot surfaces. The measurement AITs are dependent upon many factors, namely initial temperature, pressure, volume, fuel/air stoichiometry, catalyst material, concentration of vapor, time lag. Therefore, the AITs reported by different ignition conditions are sometimes significantly different. This study measured the AITs of benzene, toluene and xylene isomers from time lag using AS1M E659-78 apparatus. The experimental ignition delay times were a good agreement with the calculated ignition delay times by the proposed equations wtih a few A.A.D.(average absolute deviation). Also The experimental AITs of benzene, toluene, o-xylene, m-xylene and p-xylene were $583^{\circ}C,\;547^{\circ}C,\;480^{\circ}C,\;587^{\circ}C,\;and\;557^{\circ}C$, respectively.

• 한국농촌건축학회논문집
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• 제13권4호
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• pp.1-8
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• 2011

Korea is moving toward an aging society faster than the other advance countries such as the U.S. and France. Such aging phenomena are posing greater problems in rural areas than in urban areas, and particularly, decrease in productivity caused by aging population leads to economic difficulties and hinders the improvement of housing life. The purpose of this research is to examine and identify the housing conditions of the vulnerable in rural areas and to present ways to improve the elderly housing and the housing environment in rural areas and to provide basic data for materializing the policies to enhance the quality of life. The results of this research are as follows. First, the elderly in rural areas were found to receive relatively smooth supports for services related to clothing and food through the government and social organizations. But for the housing problems, it was found that there were not any supports. Second, the poor housing environment may cause diseases to the elderly with weak immunity, so ways to remedy these problems are urgently needed. Third, the vulnerable in rural areas can hardly bear the burden of improving the housing environment, so supports from the government and social organizations are needed. Fourth, ways to support the vulnerable such as households receiving basic living subsidies and to support the poor who are not receiving such subsidies should be explored.