• 제목/요약/키워드: analysis with repeated measurements

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환경생태 자료 분석을 위한 시계열 분석 방법 연구 (A Review of Time Series Analysis for Environmental and Ecological Data)

  • 모형호;조기종;신기일
    • 환경생물
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    • 제34권4호
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    • pp.365-373
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    • 2016
  • 환경생태 자료 분석에 사용된 많은 자료가 시간에 따라 얻어지고 있다. 조사된 시점의 수가 적은 경우에는 자료가 충분한 정보를 주지 않기 때문에 반복 측정하거나 여러 지점을 조사하여 종합적인 분석을 수행하게 된다. 이때 사용하는 방법이 경시적 자료 분석(longitudinal data analysis) 또는 혼합모형(mixed model) 분석이다. 그러나 시점의 수가 많아 정보의 양이 충분하다면 반복적인 자료가 필요하지 않으며 이러한 자료는 시계열 분석 기법을 이용하여 분석하게 된다. 특히 현재와 같이 다수의 시점에서 얻어진 자료의 수가 많아지고 있는 상항에서 각 변수 간에 서로 어떤 영향을 주는지 또는 향후 어떤 경향을 띠게 되는지 예측을 원한다면 시계열 분석 기법을 사용하여 자료를 분석해야 한다. 본 연구에서는 단변량 시계열 분석(univariate time series analysis), 개입 분석(intervention time series model), 전이함수 모형 분석(transfer function model), 다변량 시계열 분석(multivariate time series model) 기법을 소개하고 현재까지 진행된 국내외 연구 논문을 살펴보았다. 또한 향후 환경생태 자료 분석에서 중요하게 사용될 수 있는 오차수정 모형(error correction model)을 소개하였다.

Effects of Heat Wave on Body Temperature and Blood Pressure in the Poor and Elderly

  • Kim, Young-Min;Kim, So-Yeon;Cheong, Hae-Kwan;Ahn, Byun-Gok;Choi, Kyu-Sik
    • Environmental Analysis Health and Toxicology
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    • 제27권
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    • pp.13.1-13.10
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    • 2012
  • Objectives: We aimed to investigate the acute effects of heat stress on body temperature and blood pressure of elderly individuals living in poor housing conditions. Methods: Repeated measurements of the indoor temperature, relative humidity, body temperature, and blood pressure were conducted for 20 elderly individuals living in low-cost dosshouses in Seoul during hot summer days in 2010. Changes in the body temperature, systolic blood pressure (SBP) and diastolic blood pressure (DBP) according to variations in the indoor and outdoor temperature and humidity were analyzed using a repeated-measures ANOVA controlling for age, sex, alcohol, and smoking. Results: Average indoor and outdoor temperatures were $31.47^{\circ}C$ (standard deviation [SD], $0.97^{\circ}C$) and $28.15^{\circ}C$ (SD, $2.03^{\circ}C$), respectively. Body temperature increased by $0.21^{\circ}C$ (95% confidence interval [CI], 0.16 to $0.26^{\circ}C$) and $0.07^{\circ}C$ (95% CI, 0.04 to $0.10^{\circ}C$) with an increase in the indoor and outdoor temperature of $1^{\circ}C$. DBP decreased by 2.05 mmHg (95% CI, 0.05 to 4.05 mmHg), showing a statistical significance, as the indoor temperature increased by $1^{\circ}C$, while it increased by 0.20 mmHg (95% CI, -0.83 to 1.22 mmHg) as outdoor temperature increased by $1^{\circ}C$. SBP decreased by 1.75 mmHg (95% CI, -1.11 to 4.61 mmHg) and 0.35 mmHg (95% CI, -1.04 to 1.73 mmHg), as the indoor and outdoor temperature increased by $1^{\circ}C$, respectively. The effects of relative humidity on SBP and DBP were not statistically significant for both indoor and outdoor. Conclusions: The poor and elderly are directly exposed to heat waves, while their vital signs respond sensitively to increase in temperature. Careful adaptation strategies to climate change considering socioeconomic status are therefore necessary.

LC/ESI-MS를 이용한 아미트롤의 정성확인 및 정량분석 (Quantitative Analysis and Qualification of Amitrole Using LC/ESI-MS)

  • 박찬구;어수미;김민영;손종열;모세영
    • 분석과학
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    • 제17권2호
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    • pp.117-129
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    • 2004
  • 본 연구에서는 극성이 높고, 휘발성이 낮아 GC나 GC/MS로 분석이 곤란한 환경매체 중의 아미트롤을 LC/ESI/MS를 사용하여 분석한 결과 다음과 같은 결론을 얻었다. 분자량이 84인 아미트롤은 LC/ESI/MS 방식에서는 m/z 85인$(M+H)^+$형태로 나타났으며, 피크강도는 30V에서 (SIR mode) 최대를 나타내었다. 질량 스펙트럼 비를 정성확인에 적용하기 위하여 실험한 결과 아미트롤은 m/z 85 와 m/z 58 이온으로 나타났으며, 50V에서 이 비는 1 : 7.03~7.58 로 나타났다. 동위원소 비를 이용한 정성확인은 isotope MS나 HR/MS가 주로 사용되나, 본 연구에서는 정성확인을 위한 보조수단으로 이용하고자 실험한 결과 아미트롤의 동위원소는 $86([M+H])^+$ 형태로 나타났으며, 시료에서(30V) m/z 85와 m/z 86의 질량 스펙트럼 비는 27.1~28.6 : 1(이론적 비 26.6 : 1)로 나타났다. 단계별 표준액을 시료의 전 처리 방법과 동일하게 처리하여 분석한 검량선의 직선성은 $y=1.09354e^6X+26947.2$이었으며, $r^2=0.99$로 나타났다. 분석의 정도관리를 위한 회수율검정과 반복 재현성을 알아보기 위한 실험에서 수질시료의 회수율은 77.64~83.44%, 토양시료에서는71.11~79.44%로 나타났으며, 각 농도 단계별 반복(5회)실험결과 상대표준편차 값은 10%이하를 나타내었다.

Comparison of Trunk Strategy to Maintain Balance during the One-Leg Stance on a Medio-Lateral Ramp and an Anterior-Posterior Ramp

  • Lee, Sang-Yeol;Lee, Myoung-Hee
    • The Journal of Korean Physical Therapy
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    • 제29권4호
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    • pp.223-226
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    • 2017
  • Purpose: This study examined two trunk strategies - medio-lateral ramp and anterior-posterior ram - and their effects on pelvis and trunk movements, providing basic material for safe ramp utilization. Methods: The present study included 20 asymptomatic males recruited from a local university. Participants were asked to stand with their feet shoulder-width apart. Their dorsal side faced the camera, and measurements were performed while standing in a neutral double stance, one leg stance, $15^{\circ}$ of medial and lateral ramp, and $15^{\circ}$ of anterior and posterior ramp. Participants were allowed to practice for 3 minutes, and each participant had a 30 seconds rest between the two ramp conditions. One-way repeated measures analysis of variance was used to determine the effects the ramp conditions on spinal alignment. In all analyses, p<0.05 was used to indicate statistical significance. Results: The trunk-inclination angle on the posterior ramp was significantly lower than that of the double stance position (p<0.05). The trunk imbalance angle was significantly higher on the medial ramp, than that on the double stance position (p<0.05). The pelvic position and pelvic torsion angles were significantly higher in the medial, lateral, and anterior ramp positions than that of the double stance position (p<0.05). The pelvic rotation angles on the medial, lateral, and anterior ramps were significantly lower than that of the double stance position (p<0.05). Conclusion: These findings suggest that when people are exposed to the same form of ramp for an extended period, posture modifications may be triggered.

Evaluation of proximal contact strength by postural changes

  • Kim, Hee-Sun;Na, Hyun-Joon;Kim, Hee-Jung;Kang, Dong-Wan;Oh, Sang-Ho
    • The Journal of Advanced Prosthodontics
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    • 제1권3호
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    • pp.118-123
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    • 2009
  • STATEMENT OF PROBLEM. Proper proximal contact is important for maintaining and stabilizing the dental arch. However, the proximal contact strength (PCS) is not a constant value and can be affected by a variety of factors. PURPOSE. This study examined the influences of postural changes on the posterior PCS. MATERIAL AND METHODS. Twelve adults with a normal occlusion and had not undergone prosthetic treatment or proximal restoration were participated in this study. A metal strip was inserted into the proximal surface and removed at a constant velocity. The contact strength was measured in every contact point between canine to second molar in both arches. The PCSs were obtained initially in the upright position, secondly in the supine position and finally in the upright position again. All measurements were repeated after a 2 hour period. Statistical analysis was carried out using the Friedman test (P < .05). RESULTS. Generally, a decrease in PCS occurred when the posture was changed from the initial upright to supine position, while it increased when the posture was changed from the supine to upright position. A significant change was observed in all areas except for between the canine-first premolar in the maxilla and between the first molar-second molar in the mandible areas. CONCLUSION. The posterior PCS, which dentists generally believe to be a static feature of occlusion, is affected significantly by posture.

전산화단층촬영법을 이용한 상악동 측벽의 형태학적 분석 (Morphological Analysis of the Sinus Lateral Wall using Computed Tomography)

  • 김용건
    • 구강회복응용과학지
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    • 제27권3호
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    • pp.285-292
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    • 2011
  • 이번 연구는 전산화단층촬영법 (computed tomography)을 이용하여 상악동 측벽의 두께를 측정하고, 상악동 거상술을 위한 측벽창 (lateral wall window)형성 시 가장 적절한 수직적 위치를 평가하고자 한다. 상악동 거상술이 필요한 30명 환자의 전산화단층촬영 방사선영상을 대상으로 분석하였다. 상악동 측벽의 두께는 상악동 하연을 기준으로 수직적 위치에 따라 분류하고, 3회 반복 측정하여 평균을 구하였다. 상악동 측벽의 두께는 상악동 하연 (sinus inferior border, SIB)을 기준으로 상방 2 mm (SIB + 2) 까지는 2 mm 이상으로 관찰되었고, 상악동의 하연을 기준으로 3 mm 상방 (SIB + 3)에서는 2 mm 미만으로 나타났다. 이번 연구에서 근거하여 측방 접근법을 이용한 상악동 거상술에서 측벽창의 위치는 상악골의 하연을 기준으로 약 3 mm 상방에서 형성하는 것이 적절할 것으로 사료된다.

협응이동훈련이 만성 뇌졸중 환자의 걷기에 미치는 효과 -단일사례설계- (The Effect of Coordinative Locomotor Training on Walking in a Chronic Stroke Patient -A Single Subject Design-)

  • 김진철;이문규;이정아;고효은
    • PNF and Movement
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    • 제16권1호
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    • pp.7-17
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    • 2018
  • Purpose: The aim of this study was to investigate the effects of coordinative locomotor training in a chronic stroke patient. Methods: A left hemiplegic patient diagnosed with a right middle cerebral artery stroke participated in this research. The patient's functional conditions were assessed, and a coordinative locomotor training program was initiated to resolve the problems identified. A set of movements deemed difficult based on the brief International Classification of Functioning, Disability and Health core set for stroke and d4501 (long-distance walking) were agreed as improvement targets. The program comprised warm up, main, cool-down, and home exercises. Repeated measurements were obtained, as follows: five times at baseline (A), 10 times during the intervention (B), and five times after the intervention (A). The study period was 7 weeks, and the intervention period was 1 h per day, twice a week for 5 weeks. Various tools, including the community walking test (CWT), 10-m walking test (10 MWT), 6-min walking test (6 MWT), and timed up and go (TUG) test, were conducted to assess the patient's walking ability. Changes in functional domains before and after the ICF Qualifier were compared. The mean values of the descriptive statistics were calculated, and a visual analysis using graphs was used to compare the rates of change. Results: The results showed that the CWT, 10 MWT, 6 MWT, and TUG test scores during the intervention period improved and that this improvement remained, even during the baseline period. In addition, the ICF Qualifier before and after the comparison decreased from moderate to mild. Conclusion: Based on the results, we propose that coordinative locomotor training can have positive effects on community ambulation of chronic stroke patients.

대기 굴절률을 이용한 원형레일 기반 지상 SAR 자료의 대기보정 (Atmospheric Correction of Arc-Rail Type GB-SAR Using Refractive Index of Air)

  • 이재희;김광은;조성준;성낙훈;이훈열
    • 대한원격탐사학회지
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    • 제28권2호
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    • pp.237-243
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    • 2012
  • 이 논문에서는 중심주파수 9.65 GHz의 X-밴드 안테나를 이용한 원형레일 기반의 지상 SAR(Arc-SAR) 시스템의 반복 실험을 통해 대기 효과를 정량적으로 분석하였다. 안정된 신호 획득을 위해 고정된 삼각삼면반사체 4개를 사용하였는데 이에 의한 신호는 약 43시간에 걸쳐 연속적으로 획득되었다. 분석 결과 반사체는 고정된 상태였지만 약 5 radian(12.4 mm)의 최대 오차를, 총 65회의 실험에 대한 RMSE는 1.62 radian(4 mm)을 보였다. 이러한 위상변화 양상은 온도, 습도, 그리고 기압을 통해 산출되는 대기굴절률의 변화 양상과 높은 상관관계를 보였다. 대기굴절률을 이용한 보정을 선택된 16시간에 대해 적용하였고 보정 결과 RMSE는 1.74 radian(4.3 mm)에서 0.10 radian(0.24 mm)으로 감소하여 보정이 효과적으로 이루어졌음을 확인하였다.

뇌졸중으로 인한 편마비 환자의 슬괵근 유연성과 보행능력에 대한 신경가동기법, 정적 신장기법 및 수축-이완기법의 즉각적 효과 비교 (Comparison the Initial Effects of Nerve Mobilization Techniques, Static Stretching and Contract-Relax on Hamstring Flexibility and Walking Ability in Post-Stroke Hemiplegia Patients)

  • 김용정;김택연;김선엽;오덕원
    • 대한물리의학회지
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    • 제6권4호
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    • pp.369-379
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    • 2011
  • Purpose : The purpose of this study is to compare the initial effect of nerve mobilization (NM), static stretching (SS), and contract-relax (CR) techniques to find the best method in improving hamstring flexibility and gait function in patients with hemiplegia. Methods : Eleven patients with hemiplegia were included in this study. Passive knee extension (PKE) range of motion and the sit and reach (SR) test were used to measure hamstring flexibility, while timed up and go (TUG) and the 10m walking (10MW) test were used to measure the subject's gait. Measurements on each test were assessed prior to the experiment, immediately following the experiment, and 30 minutes after the experiment. Analysis of the results utilized a repeated measures analysis of variance to examine hamstring flexibility and the difference in walking ability. Results : The results suggest significant increases in NM, SS, and CR techniques as they relate to hamstring flexibility (p<.05) following (both immediate and 30 minutes post experiment) PKE range of motion and the SR test, but post-hoc showed no significant difference between the three techniques (p>.05). Additionally, the results suggest significant increases in NM, SS, and CR techniques as they relate to gait function (p<.05) following the TUG test, but found no significant difference in the 10MW test (p>.05). Post-hoc analysis between the three techniques suggests that only the NM technique significantly changed gait function. The time of TUG and 10MW test showed no significant difference between the three techniques before an experiment, just after an experiment, and 30 minutes following the experiment according to the measurement points in time (p>.05). Conclusion : This study suggests NM, SS, and CR techniques immediately improve hamstring length and flexibility while improving gait function in patients with hemiplegia.

강절형 목질 문형라멘프레임의 수평내력성능 평가 (Evaluation of The Lateral Strength Performance of Rigid Wooden Portal Frame)

  • 이인환;송요진;홍순일
    • Journal of the Korean Wood Science and Technology
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    • 제45권5호
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    • pp.535-543
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    • 2017
  • 목구조물 기둥-보 접합물로는 슬릿 가공된 부재에 강판을 삽입한 형상이 통용되고 있다. 본 연구에서는 접합부가 접착된 강절형 문형라멘프레임 및 강판 대용인 목질접합물을 제작하여 절반은 기둥부재에 일체화하고 나머지 절반은 보부재와 핀으로 접합한 반강절형 문형라멘프레임을 제작하였다. 목질 문형라멘프레임들은 강판삽입형 접합부 문형라멘프레임과 수평내력성능을 비교 분석하였다. 수평내력성능은 완전탄소성모델 분석과 구간별 강성변화율 및 단기허용전단내력으로 평가하였다. 실험결과, 강절형 문형라멘프레임의 최대내력이 강판삽입형 접합부 문형라멘프레임 보다 낮게 측정되어 항복 내력은 0.58, 종국내력은 0.48로 산출되었으나, 초기강성과 소성률은 각각 1.35, 1.1 향상된 값이 측정되었다. 반강절형 문형라멘프레임의 완전탄소성모델 분석 결과 최대내력은 강절형 문형라멘프레임보다 낮았으나 파괴 후 인성이 우수하여 종국내력은 1.05~1.07 높은 값이 산출되었다. 강판삽입형 문형라멘프레임은 반복 시험이 진행됨에 따라 강성이 급격히 감소한 반면 접합부가 목질로된 문형라멘프레임들의 강성은 서서히 감소되었다.