• 한국산업보건학회지
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• 제31권4호
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• pp.427-439
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• 2021

Objectives: This study aims to investigate differences in microbial contamination according to the duration and environment of mask wearing. Methods: Forty-five participants were recruited from workers in an offices, multi-purpose facilities, and a schools. After wearing of KF94 mask for two. four, and six hours, the microorganisms adsorbed on the outer and inner layers of the mask were inoculated on BAP(Blood Agar Plate), Chocolate agar, and SDA plates. The bacterial count (CFUs: colony-forming units) cultured in each plate was measured and analyzed for changes in filtration efficiency. Results: The microbial contamination of masks worn in classrooms, offices, and multi-purpose facilities showed a significant difference depending on the environment (p<0.000). The measured CFUs increased significantly according to the time wearing the mask. The difference between the inner and outer layers of the mask was also significant (p<0.05). However, there was no statistical difference in the filtration efficiency of the masks by duration time (p=0.515). Conclusions: Masks worn by workers in the offices, multi-purpose facilities, and schools showed an increase of microbial contamination with the amount of time wearing the mask. The results indicate that the masks used in daily life may have adverse health effects if they are worn for a long time or reused over several days without the realizing that the masks can be contaminated with biological hazards. Guidelines on the safe threshold time for mask use should be established through further research.

• 대한치과보철학회지
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• 제8권1호
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• pp.77-79
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• 1968

The swallowing threshold tests were conducted on the 8 subjects over one month of full denture wearing experience of Korean. The results were follows. 1) The swallowing threshold of the full denture wearer was higher than that of the normal control group. 2) The swallowing threshold of the full denture wearer was different according to the quality and quantity of the test food. 3) The swallowing threshold of full denture wearer seemed to be no correlation between short and long duration of wearing experience.

• The Journal of Korean Physical Therapy
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• 제13권3호
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• pp.693-699
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• 2001

The use of AFO in the management of patients with hemiplegia has been somewhat controversial. The purpose of the study was to identify the influence of the plastic ankle foot orthoses(AFO) on the characteristics of pelvic tilt in the patients with hemiplegia. Sixteen hemiplegic patients participated. The angle of pelvic tilt were measured using the BROM II . Results showed that the hemiplegia who weared plastic AFO, the angle of pelvic tilt was significantly less than not weared subjects. However. duration of wearing a plastic AFO and the degree of spasticity were not affected to the angle of pelvic tilt. Therefore the patients with hemiplegia should consider using the brace for the right purpose, also need to maintain the mobility of ankle joint while wearing the plastic AFO.

• 한국치위생학회지
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• 제14권4호
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• pp.539-545
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• 2014

Objectives : The purpose of the study is to investigate the knowledge and self care behaviors of orthodontic patients using clear aligner. Methods : A total of 181 orthodontic patients using clear aligner in Daegu filled out the self-reported questionnaire from September 6 to October 18, 2010. and 162 subjects completed orthodontic treatment. Results : There existed a significant difference in knowledge and self care behaviors between gender and wearing duration of clear aligner(p<0.01). Treatment duration influenced significantly on the score of self care behaviors(p<0.01) and the high score of self care behavior showed in short duration of treatment. Conclusions : Self care behaviors were closely correlated with treatment duration. An information for the clear aligner will be helpful to improve the knowledge and self care behaviors.

• 재활복지공학회논문지
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• 제11권4호
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• pp.323-330
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• 2017

무릎 슬리브는 재활뿐만 아니라 스포츠 활동 시 손상 예방의 목적으로도 사용되고 있다. 무릎 슬리브의 스포츠 손상 예방을 정의하기 위해서는 고유수용성감각으로부터 기인하는 균형을 평가하는 것이 중요한 요소이다. 본 연구의 목적은 골지 건 기관 자극 패드 무릎 슬리브의 효과를 분석하는 것이다. 5명의 건강한 성인 남성이 본 연구의 실험대상자로 참여하였다. 실험대상자들은 일반 무릎 슬리브와 자극 패드 슬리브를 착용한 상태에서 각각 BIODEX에서 설정된 타겟(Target) 각도를 재연하였고, 한 발 서기 동작을 수행하였다. 각도 재연성 평가의 결과를 보면, 5명의 실험대상자 중 4명의 실험대상자는 무릎 슬리브를 착용했을 때 보다 자극 패드 슬리브 착용 시 %Target angle이 증가하는 결과를 보였다. 한 발 서기 동작 수행 시 무릎 슬리브 착용 시 보다 자극 패드 슬리브 착용 시 유지 시간(duration time)이 증가했으며 x, y 방향에서 COP 길이가 모두 감소했다(COPx - 무릎 슬리브: $162.06{\pm}58.99mm$, 자극 패드 무릎 슬리브: $149.03{\pm}45.30mm$; COPy - 무릎 슬리브: $310.79{\pm}115.89mm$, 자극 패드 무릎 슬리브: $291.57{\pm}76.53mm$). 초기 전이구간, 정적 구간, 말기 전이구간이 차지하는 비율은 무릎 슬리브 착용 시와 자극 패드 무릎 슬리브 착용 시에 유의한 차이를 보였다 (all, p < 0.05). 본 연구의 결과로부터 골지 건 기관 자극 패드 무릎 슬리브 착용이 고유수용성 감각과 균형에 긍정적인 영향을 미치는 것을 확인할 수 있었다.

• 한국운동역학회지
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• 제16권1호
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• pp.65-79
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• 2006

The purpose of this study was firstly to investigate correctional function of custom semi-rigid foot orthotics for excessively pronated people during gait by observing comfort, navicular movement and leg muscles' activity according to short-term and mid-term wearing duration and secondly to understand positive and/or negative point of view of a recently proposed paradigm related to foot orthotics more profoundly. Sixteen subjects who showed excessive pronation at navicular drop test were recruited for this study. Custom semi-rigid foot orthotics were made fitting for foot characteristics of the subjects by podiatry division of Otto Bock Korea company. While wearing the foot orthotics for two months, comfort of wearing were questioned and vertical navicular movement and electromyography of leg muscles during gait were measured at the condition of both immediately after and 2 months after including a control condition, respectively. The subjects were required to walk on a treadmill at the speed of 1.5m/s and four digital video camera filmed the movement of navicular process at the speed of 60 frames/s. In conclusion, in excessively pronated group continuous increase of comfort from short-term to mid-term wearing of custom foot orthotics is assumed to be closely related with short-term and mid term correctional action, of which are consisted the decrease of the range of navicular drop and navicular raisins- the faster timing of minimum navicular position occurring, and the decrease of leg muscles' activities. This conclusion could lead to positively accept new paradigm related to foot orthotics suggested by Nigg and the author suggest that in the future study the variable which could observe navicular movement would be one of major variables to study preferred path of skeleton in the paradigm.

• 미생물학회지
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• 제46권2호
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• pp.152-156
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• 2010

연성 콘택트렌즈 종류의 하나인 일회용 렌즈는 사용상 편리함을 주는 반면 다양한 안과적 감염성 질환을 초래한다. 안 질환을 유발하는 미생물로는 Acanthamoeba, Bacteria, Fungi 등이 있다. 렌즈 착용시 손을 이용함으로 다양한 미생물 오염은 근절이 불가피한 실정이다. 다양한 미생물의 오염으로 인해 감염성 각막염을 유발하나 정확한 미생물 동정은 미비한 상태이다. 이런 이유로 렌즈를 세척하기 위해 흔히 사용하는 식염수와 ReNu Solution (Bausch and Lomb Company, USA)의 2그룹으로 나누고 식염수와 ReNu Solution을 사용하여 1, 3, 5 10 그리고 15일에 따라 미생물 오염의 정도를 살펴보고 분리되는 미생물을 동정하고자 하였다. 대구시 D대학 안경광학과 재학생들의 안과적 건강상태를 조사한 후 그룹별 10명씩 지정하였다. 일일 착용렌즈를 1일, 3일, 5일 10일, 그리고 15일에 따라 사용 후 배지에서 세균을 배양하였다. 배양된 집락을 선택하여 그람 염색한 결과, Gram-positive cocci 33%, Gram-negative cocci 2%, Gram-positive bacilli 34%, 그리고 Gram-negative bacilli 31%로 나타냈고 이러한 세균을 동정하기 위해 API kit와 VITEK system을 이용하였다. 그 결과 콘택트렌즈의 착용에 의해 유발되는 각막염의 원인세균으로 알려진 S. aureus, P. aeruginosa 등이 분리되었다. 본 연구에서는 연성렌즈의 하나인 일일 착용렌즈의 착용시 세척액에 따른 일반세균의 분포와 일회용 렌즈의 연속 착용에 따른 병원성 세균을 조사함으로 콘택트렌즈의 사용시 위생의 필요성을 시사한다.

• 대한치과교정학회지
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• 제46권1호
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• pp.36-41
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• 2016

Objective: The aim of this study was to evaluate retention practices commonly employed by orthodontists. The objectives were to identify the types of retainer frequently used and to investigate the variations in retention practice. Methods: A total of 97 orthodontists were randomly selected, and a questionnaire consisting of 25 multiple-choice questions sent to them by mail. Upon receiving of the completed questionnaires, the data were statistically analyzed. Results: A total of 32 responses were received; among these, 59.4% of orthodontists' practiced is in a government setting and 40.6% were in private practice. A vacuum-formed retainer was the most commonly used removable retainer for both maxillary (46.9%) and mandibular (46.9%) arches, followed by a Hawley retainer (maxilla, 43.8%; mandible, 37.5%), and a fixed retainer (maxilla, 3.1%; mandible, 9.4%). Of the responding orthodontists, 78.1% prescribed full-time wear (more than 20 h per day) for a duration of 3-9 months for a maxillary arch, compared to 71.9% for the mandibular arch. Only 18.8% of the orthodontists prescribed part-time wear of the retainer for the maxillary arch, compared to 21.9% for the mandibular arch. The majority of orthodontists did not instruct their patients to stop wearing removable retainers (71.9%) or fixed retainers (66.8%) at any specific time and they preferred their patients to continue wearing retainers. Conclusions: Vacuum-formed retainers are the most commonly used retainers among orthodontists. The majority of orthodontists prescribed full-time wear for more than 20 h per day with a duration of 3-9 months and preferred indefinite use of the retainer.

• 한국산업보건학회지
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• 제20권2호
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• pp.94-101
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• 2010

This study was performed to examine the asymmetry of hearing loss among the noise exposed male workers. Findings of otoscopic examination, pure tone audiometry and tympanometry were evaluated for 179 male workers working in the noise exposed workplace. And also selfadministered structured questionnaires were used for each worker's work-related and general characteristics including personal health behaviors. There were significant differences of hearing threshold between right and left ears at 1,000 Hz and 3,000 Hz(p<0.05). And also significant differences of hearing threshold were noted in the age group over 50 at 3,000 Hz, the high risk drinking group either at 3,000 Hz and 4,000 Hz, the work duration group 10-19 years at 3,000 Hz, the noise exposure group under 90 dB(A) at 3,000 Hz, the noise exposure group over 90 dB(A) at 1,000 Hz, the non-wearing protective device group at 4,000 Hz, and the wearing protective device group at 3,000 Hz(p<0.05). Further study is needed to explore the extent and the related factors of the asymmetry of hearing loss in the general population and occupationally noise exposed group.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1121-1128
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• 2007

Subway routes $1{\sim}4$ were constructed in gravel roadbed track structure in consideration of the technological capabilities, construction cost and duration at the time of the initial construction. As such, 224.8km, approximately 81.2% of entire length, of total length of railway track at 276.9km was constructed on gravel roadbed. However, improvement of gravel roadbed to concreted roadbed began in 1998 due to problems including frequent repair works and limited time application for such works caused by occurrence of tract distortion during operation as well as lowering of roadbed functions and generation of dust caused by frictional power, impact absorption capabilities, abrasion and crushing of gravel on roadbed. Currently, this improvement is continuing with target of converting entire route into concreted roadbed structure. Therefore, this Study modifies formula for setting cant, analyze the correlation between wearing of rail side of the curvature and cant insufficiency following increasing of the running speed of the train, and to present the directions for fundamental review for adjustment of cant insufficiencies at the time of improvement of gravel roadbed to concreted roadbed that is being implemented on the operational tracks of the railway trains.