• 제목/요약/키워드: observational study

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영동 대설사례의 레이더 강설강도 추정 관계식에 관한 연구 (A Study on the Radar Reflectivity-Snowfall Rate Relation for Yeongdong Heavy Snowfall Events)

  • 정승필;권태영;박준영;최병철
    • 대기
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    • 제26권4호
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    • pp.509-522
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    • 2016
  • Heavy snowfall events have occurred frequently in the Yeongdong region but understanding of these events have trouble in lack of snowfall observation in this region because it is composed of complex topography like the "Taebaek mountains" and the "East sea". These problems can be solved by quantitative precipitation estimation technique using remote sensing such as radar, satellite, etc. Two radars which are able to cover over Yeondong region were installed at Gangneung (GNG) and Gwangdeoksan (GDK). This study uses radar and water equivalent of snow cover to investigate the characteristics of radar echoes and the $Z_e-R$ relations associated with the 10 Yeongdong heavy snowfall events during the last 5 years (2010~2014). It was found that the heights which the probability of detection (POD) of snow detection by GNG radar is more than 80% are 3,000 m and 1,500 m in convective cloud and stratiform cloud, respectively. The vertical gradient of radar reflectivity is less decreased in convective cloud than stratiform cloud. However, POD by GDK radar are lower than 80% at all layers because the majority of Yeondong observational stations are more than 100 km away from GDK radar site. Furthermore, we examined $Z_e-R$ relation from the 10 events using GNG radar and compared the "a" and "b" obtained from these examinations at Sokcho (SC) and Daegwallyeong (DG). These "a" and "b" are estimated from radar echo at 500 m (SC) and 1,500 m (DG). The values of "a" differ in their stations such as SC and DG are 30~116 and 6~39, respectively. But "b" is 0.4~1.7 irrespective of stations. Moreover, the value of "a" increased with surface air temperature. Therefore, quantitative precipitation estimation in heavy snowfall events by radar echo using fixed "a" and "b" is difficult because these values changed according to those precipitation characteristics.

초등과학영재와 일반학생의 과학적 의문 생성 패턴 분석 (An Analysis of the Patterns of Scientific Questions Generation among Elementary Science-Gifted and General Students)

  • 엄주경;이길재
    • 한국과학교육학회지
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    • 제35권4호
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    • pp.537-548
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    • 2015
  • 이 연구의 목적은 초등과학영재와 일반학생이 관찰 상황에서 나타내는 과학적 의문 생성 패턴을 분석하는 것이다. 이 연구에서 과학적 의문 생성 패턴(pattern in generating scientific questions)이란 과학적 의문의 유형(Type of scientific questions)과는 구분되는 것으로, 학생들이 탐구 과정 중 여러 유형의 의문들을 생성해가는 방식을 의미한다. 연구에 적합한 관찰 과제로 사이다 속 건포도, 촛불, 염색된 샐러리 과제를 선정하였다. 그리고 연구의 대상은 전라남도 S시 영재교육원 6학년 과학영재 26명과 같은 지역 시내에 위치한 초등학교 6학년 일반학생 27명으로 하였다. 연구 결과는 다음과 같다. 첫째, 초등과학영재와 일반학생이 관찰 상황에서 나타낸 과학적 의문 생성 패턴은 '[패턴 1] 한 가지 유형의 의문 생성', '[패턴 2] 서로 다른 유형의 의문을 차례로 생성', '[패턴 3] 서로 다른 유형의 의문을 반복하여 생성', '[패턴 4] 서로 다른 유형의 의문을 순환하여 생성', '[패턴 5] 서로 다른 유형의 의문을 반복 순환하여 생성'의 다섯 가지로 분류할 수 있었다. 둘째, 초등과학영재와 일반학생은 각각 다섯 가지 패턴을 모두 나타냈으나 그 빈도에는 차이가 있었다. 영재학생들은 [패턴 3]과 [패턴 5]를 주로 나타냈으나, 일반학생들은 [패턴 1], [패턴 2], [패턴 3]을 가장 많이 나타냈다. 이러한 연구 결과는 학생들이 탐구 과정 중 생성한 개별 의문의 유형과 더불어 각 유형의 의문들을 생성해나가는 방식 또한 매우 중요함을 시사한다. 이를 통해 교사들은 학습자의 특성에 알맞은 과학적 의문 교수 학습 전략을 수립할 수 있을 것이다.

감로수(甘露水)를 이용한 절식요법의 임상결과에 관한 후향적 관찰연구 (Clinical Outcomes after Modified Fasting Therapy Supplied with Gamrosu: A Retrospective Observational Study)

  • 신승우;김동환;신현택;오달석
    • 한방비만학회지
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    • 제16권1호
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    • pp.36-49
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    • 2016
  • Objectives: Two historical evidence supported the concept of Gamrosu. The first one was Jeho-tang, a selected thirst quencher in Chosun Dynasty and the second one was Saeng-Maek-san, Dongeuibogam's recommendation as one of the qi-vigorating summer beverages. Gamrosu is a modified fasting therapy beverage which is manufactured from those two prescriptions and the carbohydrates (420.6 kcal/d). A retrospective observational study was conducted to evaluate the clinical outcomes. Methods: Thirty-three cases were reviewed at three local Korean Medical clinics that each site's participant has finished the modified fasting for 10 consecutive days. Clinical outcomes were reviewed at pre- and post-fasting sessions by retrieving the changes of body composition, blood pressure, blood chemistries & urine tests, and subjective symptoms & fatigue scores. Results: Demographics of the observed participants were 17 of male and 16 of female. Post-Gamrosu session, -6.89% of body weight, -8.97% of body fat mass were reduced with the nutrition indices being improved (P<0.001). -8.72% of systolic blood pressure, -39.86% of serum triglyceride, -6.75% of fast blood sugar and -8.12% of waist circumference were improved (P<0.05). The levels of high sensitivity C-reactive protein (-58.34%), CRP (-43.55%) and eosinophil (-21.30%) showed the significant diminished profiles (P<0.05). Liver/kidney functions and the standard of electrolytes were maintained within normal range in stable manners. The fatigue scale scores indicated significant lower scores. Conclusions: Taken together, obesity-related clinical outcomes after a modified fasting therapy with Gamrosu were sufficiently feasible and the observed findings should be considered for further prospective clinical studies.

유비쿼터스 환경에서의 거울신경세포시스템에 근간한 동작관찰-신체훈련 (뇌졸중 환자의 상지기능과 일상생활활동에 미치는 영향) (The effect of action-observational physical training based on mirror neuron system on upper extremity function and activities of daily living in stroke patient)

  • 고효은;박진주;이경주;이은희;오명화
    • 한국전자통신학회논문지
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    • 제9권1호
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    • pp.123-130
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    • 2014
  • 본 연구는 유비쿼터스 환경에서 동작관찰-신체훈련이 뇌졸중 환자의 상지기능과 일상생활활동에 어떠한 영향을 미치는 지 알아보고자 실시하였다. 연구 대상자는 19명이며 실험군 10명, 대조군 9명으로 나누었다. 실험군은 일반 작업치료와 동작관찰-신체훈련을 병행하였고, 대조군은 일반 작업치료와 동작관찰만을 시행하였다. 훈련 과정은 4주였으며, 주 3회, 회당 30분씩 훈련에 참여하였다. 대상자 선별 후 WMFT와 MBI 평가를 시행하였으며 전-후 평가를 실시하여 증진 정도를 보고자 하였다. 그 결과 대상자들의 상지기능과 일상생활활동은 두 그룹 모두중재 후 유의한 증진을 보였다(p<.05). 하지만 각 측정 시점간의 두 군의 차이는 유의한 차이를 보이지 않았다.

Efficacy and Safety of Blood Stasis Based Herbal Medicine for Patients with Traffic Accident : A Prospective Observational Study

  • Bong, Sung Min;Jo, Hyo Rim;Jang, Woo Seok;Choi, Seong Kyeong;Sung, Won Suk;Jung, Chan Yung;Lee, Seung Deok;Kim, Kyung Ho;Kim, Eun Jung
    • Journal of Acupuncture Research
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    • 제37권3호
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    • pp.151-160
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    • 2020
  • Background: Blood stasis (BS) is commonly used for pattern identification in traumatic injuries, including traffic accidents (TAs). Various studies have identified the efficacy of Korean medicine treatments for TA patients, but studies focusing on the BS-based herbal medicine (BSHM), including Tongdo-san (TDS), are rare. Methods: This was a single-center, prospective observational study, conducted from August 24th, 2018 to December 27th, 2018, which included 40 TA patients. Participants underwent routine Korean medicine treatments including acupuncture, electronic moxibustion, cupping, physical therapy, and herbal medicine. In the herbal medicine treatment, participants took BSHM with more than 3 days including taking TDS. The primary outcome measures were the scores from a 100 mm visual analogue scale (VAS) and numerical rating scale (NRS). Secondary outcome measures included scores from EuroQol-5 dimension (EQ-5D) and EQ-VAS questionnaires, the BS and cold/heat indices, and safety assessments. Results: There were significant improvements in the VAS, NRS, EQ-5D, EQ-VAS scores, and BS index after treatment. In the sub-analysis, VAS, NRS, EQ-5D, and EQ-VAS scores were higher in groups with a higher BS index. The moderate and severe BS index groups showed more improvement than the minor BS index group, and there was a significant difference in the EQ-5D scores. There was no significant differences observed in cold/heat index groups scores. Conclusion: BS is associated with TA-related symptoms. BSHM, including TDS, may significantly reduce BS, pain, and discomfort.

식생/모래기반 자연해빈에서의 지하수위 변동특성 (Variation Characteristics of the Groundwater Level of Natural Vegetation and Sandy Beaches)

  • 박정현;윤한삼
    • 한국해양환경ㆍ에너지학회지
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    • 제19권1호
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    • pp.62-73
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    • 2016
  • 식생/모래기반 자연해빈에서의 파랑, 조석, 강우조건에 의한 지하수위 변동은 식생 환경과 밀접한 관련이 있으며 이는 식생 발달 및 지반 안정화에 크게 영향을 주는 요소이다. 본 연구는 낙동강 하구역의 사주섬 중 최서측에 위치하는 진우도를 대상으로 실험구를 구축한 후 해안선의 법선 방향으로 관측점 5곳을 선정하여 2012년 3월부터 2014년 9월까지(약 799일간) 관측된 수온, 전기전도도, 압력값을 이용하여 지하수위 변동해석을 하였다. 지하수위의 수온, 염분, 수위 변동과 조위, 파랑, 강수량 등의 외력조건과의 시계열 분석 및 상관분석을 통하여, 소상대 정점에서는 파랑 및 조위의 영향, 식생 및 모래지반 정점에서는 강수량 및 조위의 영향을 크게 받음을 알 수 있었다. 고파랑 내습시 관측점간의 지하수위 및 전기전도도의 공간적 거동을 살펴본 결과 Sand dune 및 Vegetation zone이 시작되는 인근에서 담수층과 해수층의 천이 영역(Transition zone)이 존재하였다.

한반도 남동해안 해상풍 모의에 적합한 경계층 물리방안 연구 (Study on planetary boundary layer schemes suitable for simulation of sea surface wind in the southeastern coastal area, Korea)

  • 김유근;정주희;배주현;송상근;서장원
    • 한국환경과학회지
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    • 제14권11호
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    • pp.1015-1026
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    • 2005
  • The southeastern coastal area of the Korean peninsula has a complex terrain including an irregular coastline and moderately high mountains. This implies that mesoscale circulations such as mountain-valley breeze and land-sea breeze can play an important role in wind field and ocean forcing. In this study, to improve the accuracy of complex coastal rind field(surface wind and sea surface wind), we carried out the sensitivity experiments based on PBL schemes in PSU/NCAR Mesoscale Model (MM5), which is being used in the operational system at Korea Meteorological Administration. Four widely used PBL parameterization schemes in sensitivity experiments were chosen: Medium-Range Forecast (MRF), High-resolution Blackadar, Eta, and Gayno-Seaman scheme. Thereafter, case(2004. 8. 26 - 8. 27) of weak-gradient flows was simulated, and the time series and the vertical profiles of the simulated wind speed and wind direction were compared with those of hourly surface observations (AWS, BUOY) and QuikSCAT data. In the simulated results, the strength of rind speed of all schemes was overestimated in complex coastal regions, while that of about four different schemes was underestimated in islands and over the sea. Sea surface wind using the Eta scheme showed the highest wind speed over the sea and its distribution was similar to the observational data. Horizontal distribution of the simulated wind direction was very similar to that of real observational data in case of all schemes. Simulated and observed vertical distribution of wind field was also similar under boundary layer(about 1 km), however the simulated wind speed was underestimated in upper layer.

초등학교 4학년 과학 수업에서 학생들의 포트폴리오 학습 경험 및 인식 변화 (Students' Experience and Changes in Perception Regarding Portfolio Based on Learning in Fourth Grade Science Classes)

  • 김찬종;임인숙;박영신;박현주
    • 한국초등과학교육학회지:초등과학교육
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    • 제26권4호
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    • pp.372-384
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    • 2007
  • The purposes of this study was to analyze qualitatively changes in students' experience and perceptions in relation to studying science using portfolios and any resultant effects on the portfolio itself. Five fourth-grade elementary students from one small city participated in this study. Data was collected through interviews as well as through student portfolios containing the science content matter of two units over two weeks. Observational diaries recorded by a teacher were also used to test the reliability of data collection. All interviews with students were transcribed to develop a suitable network to categorize students' responses. Students' portfolios were analyzed in order to reveal their essential characteristics in combination with their teacher's observational diaries. The results were as follows. First, student perceptions of their portfolios were categorized into three different levels; superficial, extended, and moderate perceptions. The changes in perception could also be divided into three levels; consistent-superficial, unstable, and a progressive-extended pattern. Second, the experience of students with their portfolio were investigated in terms of the following; successfully completing the elements of the portfolio, development of evidence, interaction with peers, teachers, and parents, and the standards of evaluation used for the portfolios. Third, the perceptions and experience of working on the portfolio by students had a number of direct effects on the way in which students actually created and developed their portfolios. Finally, students with positive attitudes towards their portfolios actively participated in the portfolio experience and finally understood what it meant completely. However, students with negative attitudes regarding portfolio based work, did not leave the experience with any heightened awareness of the utility or indeed, purpose of portfolio based work.

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Anti-Diabetic Medications Do Not Influence Risk of Lung Cancer in Patients with Diabetes Mellitus: a Systematic Review and Meta-analysis

  • Nie, Shu-Ping;Chen, Hui;Zhuang, Mao-Qiang;Lu, Ming
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권16호
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    • pp.6863-6869
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    • 2014
  • Objectives: Several preclinical and observational studies have shown that anti-diabetic medications (ADMs) may modify the risk of lung cancer. We performed a systematic review and meta-analysis evaluating the effect of metformin, sulfonylureas (SUs), thiazolidinediones (TZDs), and insulin on the risk of lung cancer in patients with diabetes mellitus (DM). Materials and Methods: We conducted a systematic search of Pubmed and Web of Science, up to August 20, 2013. We also searched the Conference Proceedings Citation Index (CPCI) and China National Knowledge Infrastructure (CNKI) for abstracts from major meetings. Fixed or random effect pooled measures were selected based on heterogeneity among studies, which was evaluated using Q test and the I2 of Higgins and Thompson. Meta-regression was used to explore the sources of between-study heterogeneity. Publication bias was analyzed by Begg's funnel plot and Egger's regression test. Associations were assessed by odds ratios (ORs) with 95% confidence intervals (CIs). Results: A total of 15 studies (11 cohort, 4 case-control) were included in this meta-analysis. In observational studies no significant association between metformin (n=11 studies; adjusted OR=0.99, 95%CI: 0.87-1.12), SUs (n=5 studies; adjusted OR=0.98, 95%CI: 0.79-1.22), or TZDs (n=7 studies; adjusted OR=0.92, 95%CI: 0.75-1.13), insulin (n=6 studies; adjusted OR=1.13, 95%CI: 0.79-1.62) use and risk of developing lung cancer was noted. There was considerable inherent heterogeneity between studies not explained by study design, setting, or location. Conclusions: Meta-analysis of existing studies does not support a protective or harmful association between ADMs use and risk of lung cancer in patients with DM. There was considerable heterogeneity across studies, and future, well-designed, prospective studies would be required for better understanding of any association.

잠재범주분석을 이용한 원인적 영향력 추론에 관한 연구 (Estimating Average Causal Effect in Latent Class Analysis)

  • 박가영;정환
    • 응용통계연구
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    • 제27권7호
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    • pp.1077-1095
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    • 2014
  • 관찰연구를 이용하여 인과관계를 추론할 경우 무작위 통제시험과는 달리 교란변수로 인한 편향을 제어하기 위한 통계적 전략이 필요하다. 최근에는 성향점수(propensity score) 를 이용한 짝짓기나 원인변수의 역확률을 가중치로 사용하는 주변구조모형이 제안되어 사용되고 있다. 이러한 인과관계 추론은 처치(treatment)가 명확히 주어진 경우에 교란변수를 통제하고 그 처치가 결과에 미치는 영향을 평가하는 방법에 초점이 맞추어져 있다. 하지만 기존의 방법의 경우 원인변수인 처치가 직접관측이 가능한 범주형 변수이고 결과변수 또한 직접관측이 가능한 변수인 경우에만 사용할 수 있는 한계를 갖고 있다. 본 연구에서는 원인변수인 처치와 결과변수의 결괏값의 직접적인 관측이 어려운 경우, 측정오차를 고려한 잠재범주모형(latent class analysis)의 변수로 모형화 함으로써 잠재범주 간의 원인적 영향력을 추정하는 방법을 제시하고자 한다. 그리고 미국의 The National Longitudinal Study of Adolescent Health 자료를 이용하여, 약물사용의 잠재범주에 대한 청소년기의 비행(delinquency)이라는 잠재범주의 원인적 영향력을 추정하였다.