• 제목/요약/키워드: Fatigue

검색결과 9,527건 처리시간 0.043초

후반고리관 양성돌발두위현훈의 치료에서 재평가 시기에 대한 피로 현상의 영향 (Influence of Fatigability on the Timing of Reassessment in the Treatment of Posterior Canal Benign Paroxysmal Positional Vertigo)

  • 김창희;신정은;신용국;송미현;심대보
    • Korean Journal of Otorhinolaryngology-Head and Neck Surgery
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    • 제61권12호
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    • pp.658-662
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    • 2018
  • Background and Objectives The early assessment of treatment is not done for benign paroxysmal positional vertigo (BPPV) since the well-known phenomenon of fatigability after a repeated positional test can mimic successful treatment. The aim of this study is to evaluate the clinical implication of 'fatigability' after Epley maneuver and to identify the therapeutic efficacy of Epley maneuver in posterior canal BPPV (PC-BPPV). Subjects and Method This study was prospectively conducted by two dizziness clinics on 51 consecutive patients diagnosed with PC-BPPV. All patients included in the study received Epley maneuver treatment. The therapeutic results were reassessed immediately after a single trial of Epley maneuver. After 30 minutes, results were reassessed repeatedly to confirm the fatigability of diagnostic procedure immediately after treatment. If the treatment was not successful after 30 minutes, Epley maneuver was repeatedly performed until complete resolution. Results Immediately after the first maneuver, 45 of 51 (88.2%) patients had neither vertigo nor nystagmus during the positional test. All patients demonstrated complete resolution after receiving one to three Epley maneuvers on the day of diagnosis. 'Fatigability (false negative result)' was confirmed for only one case (1 of 6 patients, 16.7%), in which nystagmus was observed after 30 minutes but not identified immediately after the first Epley maneuver. Conclusion The therapeutic efficacy of Epley maneuver is very high in PC-BPPV. Considering the possibility of fatigability when reassessment is performed immediately after therapeutic maneuver, clinicians should avoid assessing the outcome immediately after treatment in patients with PC-BPPV.

교대근무 간호사의 식사경험에 관한 현상학적 융합연구 (A phenomenological convergence study on the mealtime experience of shift nurses on duty.)

  • 김수정;김원정
    • 한국융합학회논문지
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    • 제10권1호
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    • pp.307-316
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    • 2019
  • 본 연구의 목적은 교대근무 간호사들의 근무 중 식사시간에 대한 경험의 의미와 본질을 이해하고자 하는 것이다. 자료수집은 교대근무를 하고 있는 종합병원 간호사 6명을 대상으로 개별 인터뷰 방법을 사용하였다. van Manen의 해석학적 현상학적 방법을 이용해 분석하였으며, 연구 결과 총 7개의 주제가 도출되었다. 각각의 주제는 '배고픔이 잊혀져 감', '피곤함에 자리를 양보함', '동료에게 미안하고 눈치가 보임', '짧은 시간에 폭풍 흡입함', '환자에 대한 책임과 내 몸에 대한 책임 사이에서 갈등함', '찾고 싶은 자유와 권리의 시간임', '소중한 시간이길 소망함' 이었다. 본 연구 결과는 교대 근무 간호사의 근무 환경에 대한 융합적 이해를 제공한 것에 그 의의가 있다.

Seismic damage mitigation of bridges with self-adaptive SMA-cable-based bearings

  • Zheng, Yue;Dong, You;Chen, Bo;Anwar, Ghazanfar Ali
    • Smart Structures and Systems
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    • 제24권1호
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    • pp.127-139
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    • 2019
  • Residual drifts after an earthquake can incur huge repair costs and might need to replace the infrastructure because of its non-reparability. Proper functioning of bridges is also essential in the aftermath of an earthquake. In order to mitigate pounding and unseating damage of bridges subjected to earthquakes, a self-adaptive Ni-Ti shape memory alloy (SMA)-cable-based frictional sliding bearing (SMAFSB) is proposed considering self-adaptive centering, high energy dissipation, better fatigue, and corrosion resistance from SMA-cable component. The developed novel bearing is associated with the properties of modularity, replaceability, and earthquake isolation capacity, which could reduce the repair time and increase the resilience of highway bridges. To evaluate the super-elasticity of the SMA-cable, pseudo-static tests and numerical simulation on the SMA-cable specimens with a diameter of 7 mm are conducted and one dimensional (1D) constitutive hysteretic model of the SMAFSB is developed considering the effects of gap, self-centering, and high energy dissipation. Two types of the SMAFSB (i.e., movable and fixed SMAFSBs) are applied to a two-span continuous reinforced concrete (RC) bridge. The seismic vulnerabilities of the RC bridge, utilizing movable SMAFSB with the constant gap size of 60 mm and the fixed SMAFSBs with different gap sizes (e.g., 0, 30, and 60 mm), are assessed at component and system levels, respectively. It can be observed that the fixed SMAFSB with a gap of 30 mm gained the most retrofitting effect among the three cases.

해양환경의 변동성을 고려한 해상풍력터빈 지지구조물의 기대수명 평가 (Expected Life Evaluation of Offshore Wind Turbine Support Structure under Variable Ocean Environment)

  • 이기남;김동현;김영진
    • 한국해양공학회지
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    • 제33권5호
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    • pp.435-446
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    • 2019
  • Because offshore structures are affected by various environmental loads, the risk of damage is high. As a result of ever-changing ocean environmental loads, damage to offshore structures is expected to differ from year to year. However, in previous studies, it was assumed that a relatively short period of load acts repeatedly during the design life of a structure. In this study, the residual life of an offshore wind turbine support structure was evaluated in consideration of the timing uncertainty of the ocean environmental load. Sampling points for the wind velocity, wave height, and wave period were generated using a central composites design, and a transfer function was constructed from the numerical analysis results. A simulation was performed using the joint probability model of ocean environmental loads. The stress time history was calculated by entering the load samples generated by the simulation into the transfer function. The damage to the structure was calculated using the rain-flow counting method, Goodman equation, Miner's rule, and S-N curve. The results confirmed that the wind speed generated at a specific time could not represent the wind speed that could occur during the design life of the structure.

부인과 수술 후 한방 조기 회복 치료를 받은 입원 환자에 대한 후향적 분석 (Traditional Korea Medicine for Enhanced Recovery after Surgery (ERAS) in Inpatients after Gynecological Surgery: Retrospective Analysis)

  • 김혜원;유정은
    • 대한한방부인과학회지
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    • 제32권3호
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    • pp.142-161
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    • 2019
  • Objectives: The purpose of this study is to report the effect and safety of traditional Korean medicine (TKM) for enhanced recovery after surgery (ERAS) after gynecological surgery. Methods: The study is conducted by analyzing the medical records of the hospitalized patients in TKM hospital. Eighty-six patients were enrolled who received TKM for ERAS after gynecological surgery from January 2015 to April 2018. We performed statistical analysis by using SPSS ver. 25.0. To prove the effect and safety of TKM for ERAS, we analyzed symptoms and Hemoglobin (Hb), aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and serum creatinine (Cr) with glomerular filtration rate (GFR). In addition, we checked other adverse reactions that the patients complained to prove the safety of TKM for ERAS. Results: Among symptoms of pain, there was a statistically significant decrease in abdominal pain, lower back pain, and shoulder pain. Other symptoms showed statistically significant improvement in fatigue, abdominal tympanosis, operation-site discomfort, dizziness, urinary discomfort, throat discomfort, constipation, dyspepsia and colporrhagia. Anemia in both ferritin combination treatment group and herbal medicine only group showed significant improvement. There was no liver damage or renal damage by TKM. Conclusions: The result has shown that TKM for ERAS after gynecological surgery is effective and safe. The further study of TKM for ERAS with more patients is needed.

여성 류마티스관절염 대상자의 고혈압, 당뇨, 이상지질혈증의 유병률, 인지율, 치료율 및 조절률 (Prevalence, Awareness, Treatment, and Control of Hypertension, Diabetes, and Dyslipidemia Among Patients with Rheumatoid Arthritis)

  • 윤혜원;부선주
    • 한국보건간호학회지
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    • 제33권2호
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    • pp.228-241
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    • 2019
  • Purpose: The purpose of this study was to evaluate the prevalence, awareness, treatment and control of hypertension, diabetes, and dyslipidemia among women with rheumatoid arthritis. Methods: This cross-sectional study of 288 women with rheumatoid arthritis was conducted in a university-affiliated hospital. Data were collected by reviewing the women's medical charts and self-report questionnaires. Results: The prevalence of hypertension, diabetes and dyslipidemia was 27.8%, 5.9% and 48.3%, respectively. Despite the high prevalence of dyslipidemia, the subjects'awareness of it and its treatment rates were the lowest, which resulted in a low control rate. Of the 288 subjects, 158 (55%) had at least one of the three conditions. The prevalence of the combination of cardiovascular risk factors increased with age, and 32.7% of those aged 60 or older had two or three of the cardiovascular risk factors. Combinations of cardiovascular risk factors were significantly related with severe pain and fatigue. Conclusion: Cardiovascular risk factors were highly prevalent among the women with rheumatoid arthritis, but the rates of awareness, treatment, and control were suboptimal. There is a pressing need to facilitate the prevention, early detection and appropriate management of hypertension, diabetes and dyslipidemia among patients with rheumatoid arthritis in order to prevent cardiovascular disease.

Strengthening RC frames subjected to lateral load with Ultra High-Performance fiber reinforced concrete using damage plasticity model

  • Kota, Sai Kubair;Rama, J.S. Kalyana;Murthy, A. Ramachandra
    • Earthquakes and Structures
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    • 제17권2호
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    • pp.221-232
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    • 2019
  • Material non-linearity of Reinforced Concrete (RC) framed structures is studied by modelling concrete using the Concrete Damage Plasticity (CDP) theory. The stress-strain data of concrete in compression is modelled using the Hsu model. The structures are analyzed using a finite element approach by modelling them in ABAQUS / CAE. Single bay single storey RC frames, designed according to Indian Standard (IS):456:2000 and IS:13920:2016 are considered for assessing their maximum load carrying capacity and failure behavior under the influence of gravity loads and lateral loads. It is found that the CDP model is effective in predicting the failure behaviors of RC frame structures. Under the influence of the lateral load, the structure designed according to IS:13920 had a higher load carrying capacity when compared with the structure designed according to IS:456. Ultra High Performance Fiber Reinforced Concrete (UHPFRC) strip is used for strengthening the columns and beam column joints of the RC frame individually against lateral loads. 10mm and 20mm thick strips are adopted for the numerical simulation of RC column and beam-column joint. Results obtained from the study indicated that UHPFRC with two different thickness strips acts as a very good strengthening material in increasing the load carrying capacity of columns and beam-column joint by more than 5%. UHPFRC also improved the performance of the RC frames against lateral loads with an increase of more than 3.5% with the two different strips adopted. 20 mm thick strip is found to be an ideal size to enhance the load carrying capacity of the columns and beam-column joints. Among the strengthening locations adopted in the study, column strengthening is found to be more efficient when compared with the beam column joint strengthening.

이음철근이 보강된 반단면 프리캐스트 판넬 이음부의 강도 안전성 평가 (Safety Evaluation of the Precast Half Deck Pannel Joints Reinforced by Connection Rebar)

  • 황훈희
    • 한국안전학회지
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    • 제34권2호
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    • pp.40-47
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    • 2019
  • The Half-depth precast deck is a structural system that utilizes pre-cast panels pre-built at the factory as formwork at the construction stage and as a major structural member at the same time after completion. These systems have joints between segments, and the detail and performance of the joints are factors that have a very large impact on the quality, such as the constructability and durability of the bridge decks. In this study, strength performance evaluation was performed for improved joints using connecting rebar by experimental method. Static loading tests were conducted on the test specimen with improved joint, those with existing joint and those without joint. The test results of the specimens were compared to each other, and the flexural strength required by the design was compared. The flexural strength required in the design was presented by finite element analysis. It has been shown that the flexural strength of the specimens with joints were more than twice that required by the design. But the flexural strength of the specimen with existing joint was about 84% of that without joint. The flexural strength of the specimen with improved joints was a nearly similar degree of that compared to the specimen without joint. And a comparison of the moment-deflection relationship curves of the two specimens also shows a very similar flexural behavior. It is confirmed that improved joint has sufficient flexural strength. In addition to strength, the bridge decks require serviceability, such as deflection and cracking, and in particular, fatigue resistance due to repetitive live loads is an important performance factor. Therefore, further verification studies are required.

고속철도차량 관절대차 갱웨이 링의 내구성 평가 (Durability Evaluation of Gangway Ring for the Articulated Bogie of High speed Railway Vehicle)

  • 강길현
    • 한국산학기술학회논문지
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    • 제20권5호
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    • pp.66-72
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    • 2019
  • 동력 집중식 고속 철도차량의 승차감과 주행 안정성 향상 방안으로서 채택한 관절형 대차는 차체와 결합된 기존 독립대차와 달리 객차 사이를 갱웨이 링에 의하여 연결한다. 갱웨이 링은 열차 주행 동안 객차분리를 방지하면서 객차사이 승객 이동에 대한 절대적 안전을 확보되어야 함에도 불구하고, 아직까지 정량적인 내구성 시험기준 설정이 미비하다. 따라서 동력 집중식 고속 철도차량의 승차감과 승객 안전성을 향상을 위해서는 관절형 대차 갱웨이 링에 대한 내구성 평가의 시험기준에 대한 체계적인 연구가 중요하다. 본 연구에서는 고속 철도차량 관절형 대차의 갱웨이 링에 대한 안전성을 검토하기 위하여, 열차 운행조건에 준한 전후, 좌우 및 수직의 3축 모드로부터 7가지 혼합모드 하중조건을 도출하였다. 이 하중조건하에 유한요소해석결과로부터 각 부품들의 안전율은 최소 2.4 이상이다. 또한 변형률-피로수명설계관점에서 내구성 해석을 통하여 피로안전성을 평가하였다. 본 갱웨이 링에 대한 내구성 시험은 혼합모드 하중조건하에 총 4단계의 1,000만 사이클을 수행하였다. 내구성 시험 후에 침투 탐상 검사기법을 이용하여 각 부품의 결함유무를 검토하였다.

결합부 강화구조용 탄소복합재 자동차 부품 개발 (Development of the CFRP Automobile Parts Using the Joint Structure of the Dissimilar Material)

  • 고관호;이민구;허몽영
    • Composites Research
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    • 제31권6호
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    • pp.392-397
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    • 2018
  • 본 연구에서는 기존의 스틸재 타이로드를 브레이딩 공법을 적용한 탄소복합재로 개발하고자 하였다. 탄소복합재 타이로드는 기존 제품과 동등한 성능을 만족시키기 위하여 브레이딩 직조에 필요한 코어 단면설계, 코어와 탄소섬유의 접합부에 대한 구조형상설계를 진행하였다. 그리고 브레이딩 공법을 적용한 시편을 제작하여 시험평가를 통해 구조해석에 적용하였다. 제작 공정은 브레이딩 직조 후 인퓨전 공정을 거쳐 후경화 공정까지 진행하였으며 최종 제품에 대한 시험평가는 인장 시험, 비틀림 시험, 압축 시험과 피로시험을 순차적으로 진행하여 모두 만족시켰다. 또한 탄소복합재 타이로드의 중량을 기존 제품 대비 약 37% 정도 경량화시킬 수 있었다.