• 제목/요약/키워드: Monthly variations

검색결과 365건 처리시간 0.027초

증발량의 시공적 변화 (Seasonal Variations of the Evaporation in Korea)

  • 이광호;김문일
    • 물과 미래
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    • 제18권3호
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    • pp.243-251
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    • 1985
  • 우리나라에서 증발량의 시간적 공간적 분포를 4대강 유역과 영동지방으로 나누어 기후자료를 이용하여 분석하고, 호수면 증발량과 증발산위량을 계산하여 다른 증발량 및 강수량과 비교함으로서 지역별 물수지요소의 변화를 조사하였다. 또한 증발에 영향을 미치는 기상요소와의 관계를 분석함으로서 기후관측요소 상호간의 관계를 규명하였다. 소형증발계에 가장 큰 영향을 미치는 기상요소는 일사량이며, 다음은 기온이나 풍속 및 상대습도 등은 그 월별값을 나타낼 때 거의 기여도가 없었다. 소형증발량과 대형증발량 및 호수면증발량은 서로 그 월별값의 상관이 0.90을 상회함으로 어느 한 증발량으로부터 유추할 수 있고, 년 소형증발계에 대한 대형증발량 및 호수면 증발량의 비는 각각 73% 및 55%정도이나, 산지에서는 그보다 약 10% 정도가 낮았다. 증발산위량은 작물생육기에 소형증발량의 약 80%에 달하나 년 평균치는 약 70% 정도이며, 강수량의 40∼60%에 달한다.

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족저 근막염의 계절성에 대한 인터넷 검색어 데이터와 건강보험심사평가원 자료의 연관성 (Correlation between Internet Search Query Data and the Health Insurance Review & Assessment Service Data for Seasonality of Plantar Fasciitis)

  • 황석민;이금호;오승열
    • 대한족부족관절학회지
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    • 제25권3호
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    • pp.126-132
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    • 2021
  • Purpose: This study examined whether there are seasonal variations in the number of plantar fasciitis cases from the database of the Korean Health Insurance Review & Assessment Service and an internet search of the volume data related to plantar fasciitis and whether there are correlations between variations. Materials and Methods: The number of plantar fasciitis cases per month was acquired from the Korean Health Insurance Review & Assessment Service from January 2016 to December 2019. The monthly internet relative search volumes for the keywords "plantar fasciitis" and "heel pain" were collected during the same period from DataLab, an internet search query trend service provided by the Korean portal website, Naver. Cosinor analysis was performed to confirm the seasonality of the monthly number of cases and relative search volumes, and Pearson and Spearman correlation analysis was conducted to assess the correlation between them. Results: The number of cases with plantar fasciitis and the relative search volume for the keywords "plantar fasciitis" and "heel pain" all showed significant seasonality (p<0.001), with the highest in the summer and the lowest in the winter. The number of cases with plantar fasciitis was correlated significantly with the relative search volumes of the keywords "plantar fasciitis" (r=0.632; p<0.001) and "heel pain" (r=0.791; p<0.001), respectively. Conclusion: Both the number of cases with plantar fasciitis and the internet search data for related keywords showed seasonality, which was the highest in summer. The number of cases showed a significant correlation with the internet search data for the seasonality of plantar fasciitis. Internet big data could be a complementary resource for researching and monitoring plantar fasciitis.

산지계류의 계절적 수온변동 특성 및 영향인자 분석 (Seasonal Variations of Stream Water Temperature and its Affecting Factors on Mountain Areas)

  • 남수연;최형태;임홍근
    • 한국물환경학회지
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    • 제35권4호
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    • pp.308-315
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    • 2019
  • The objective of this study was to investigate mountain stream water and air temperatures, area, latitude, altitude, and forest coverage in headwater catchments located in Kangwon-do, Mid-eastern Korea from 2015 to 2017. Daily mean value of mountain stream water temperature was approximately $6^{\circ}C$ lower than the daily mean value of air temperature on the monitoring sites during the observation period. Monthly mean value of mountain stream water temperature increased with increasing monthly mean value of air temperature from May to August during the observation period. Seasonal variations of mountain stream water temperature were dependent on air temperature rising and falling periods. Correlation analysis was conducted on mountain stream water temperature to investigate its relationship with air temperature, area, latitude, altitude, and forest coverage of air temperature rising and falling periods. The correlation analysis showed that there exists a relationship (Correlation coefficient: -0.581 ~ 0.825; p<0.05), particularly the air temperature showed highest correlation with mountain stream water temperature. Regression equations could be developed due to contribution of air temperature to affect mountain stream water temperature (Correlation coefficient: 0.742 and 0.825; p<0.01). Therefore, a method using various parameters based on air temperature rising and falling periods, could be recommended for predicting mountain stream water temperature.

동중국해에서 위성에서 추정된 10년 동안의 표층 입자성 유기 탄소의 시/공간적 변화 (Spatial and Temporal Variations of Satellite-derived 10-year Surface Particulate Organic Carbon (POC) in the East China Sea)

  • 손영백;이태희;최동림;장성태;김철호;안유환;유주형;김문구;정섬규
    • 대한원격탐사학회지
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    • 제26권4호
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    • pp.421-437
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    • 2010
  • SeaWiFS자료를 Maximum Normalized Difference Carbon Index(MNDCI) 알고리즘을 이용하여 추정된 particulate organic carbon(POC)는 장강에서 유입된 담수의 영향을 받는 동중국해에서 시/공간적 해양환경 변화를 조사하는데 사용했다. 10년 평균한 POC 농도는 (1997년-2007년) 뚜렷한 계절적 변화를 보인다. POC 경년 변화는 전체 지역 평균값과 표준편차를 이용하여 세 개의 지역으로 나누어 평균한 결과에서 1998년 이후 꾸준한 감소를 보이는 장강과는 달리 감소되는 경향이 관측되지 않았다. 자세한 POC 시/공간적인 변화를 관측하기 위하여, 2000년부터 2007년까지 여름철 (6월-9월) 자료를 선정하여 empirical orthogonal function(EOF) 분석을 실시하였다. 첫 번째 성분은 장강으로부터 유입되는 담수의 영향으로 공간적인 변화가 이루어졌다. 두 번째 성분은 장강의 유출량과는 약한 상관관계를 보이고, 공간적으로 남-북 방향의 변화가 관측되었다. 2000년부터 2003년까지 상대적으로 높은 POC 분포는 연구지역 남쪽 부분에서 나타난다. 2004년부터 2007년까지 이런 변화는 연구지역 북쪽 부분에서 관측되었다. 장기적인 변화는 방류량의 감소에 의한 영향보다는 공간적인 변화에 기인한 것으로 사료되며, 이는 현장 관측자료에서 유사한 결과를 보였다.

마산만 준설사업 및 하수처리장 가동에 따른 진해만의 수질변동 (Water Quality Variations in Jinhae Bay by Dredging & Operating the Sewage Disposal Plant)

  • 윤석진;이인철
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2004년도 학술대회지
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    • pp.117-122
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    • 2004
  • This study investigates the spatial and temporal distribution characteristics and relationships among water quality parameters, which based on 6 years' data(from 1989 to 1994) measured at 16 stations on Jinhae Bay. The results of these analysis, monthly variations range between surface and bottom layer of water quality had a tendency to increase and decrease, and appeared to be at the maximum value in August. The relationships between concentration of COD ana nutrients(DIN and DIP), which obtained by correlation analysis of water quality, were shown $85\%$ and $74\%$, respectively. Using the cluster analysis to develop the division of the sea basin by the dendrogram, before and after dredging of Masan bay and operating a sewage disposal plant, the variation characteristics of water quality of Jinhae Bay were discussed. Through it, we can see the serious pollution of northen sea basin of Jinhae Bay(B2) although dredging Masan bay and operating the sewage disposal plant. As the results, it doesn't appear the improvement effect of water quality in spite of carrying out the effort of water quality improvement.

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경기만내 담수 유입으로 인한 시·공간적인 염분변화에 대한 연구 (Study on the Temporal and Spatial Variations of Salinity by Freshwater Discharge in Gyeonggi Bay)

  • 정정호;김국진;양근호;장윤영;박선환;김영택
    • 환경영향평가
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    • 제16권6호
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    • pp.421-432
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    • 2007
  • To investigate temporal and spatial variations of hydrodynamics and environmental conditions in Gyeonggi Bay, including Han River estuary, numerical experiments were performed using 3-dimensional fine grid numerical ocean model. The model successfully reproduced the physical phenomena already known in Gyeonggi Bay where tide and fresh water discharge are dominant forcings. The calculated harmonic constants of tide and tidal current agreed well with those of observations at nine tide stations and two tidal current stations. Tidal asymmetries along the Yeomha Waterway, mainly caused by non-linear effect, were well reproduced and agreed well with observations. Time series of salinity at four stations(A, B, C and D) and horizontal distributions of monthly averaged salinity show that Gyodong and Seokmo Waterways play an important role in fresh water discharge into the Gyeonggi Bay rather than Yeomha Waterway.

2006년 고리 주변해역에 출현하는 자치어의 종조성과 출현양상 (Species composition and abundance of larval fishes in the coastal waters off Gori, Korea in 2006)

  • 백근욱;박주면;남기문;허성회
    • 수산해양기술연구
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    • 제48권3호
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    • pp.284-292
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    • 2012
  • Species composition and abundance of larval fishes in the coastal waters off Gori in the southeastern Korea were investigated from January to December in 2006. During the study period, 32 larvae species belonging to 20 families were collected. The dominant species were Engraulis japonicius, Hexagrammos agrammus, Sillago japonicus, Acropoma japonicum, Apogon lineatus, and Konosirus punctatus. These six species accounted for 87.0% of the total number of individuals collected. The number of species, number of individuals, and species diversity indices fluctuated by season. The peak numbers of species and individuals occurred in July and May, respectively. Correlation analysis showed that monthly variations in water temperature and salinity could act as an indicators of seasonal variations in the larval fish community structure and abundance of the dominant species; in particular, the abundance of S. japonicus, A. japonicum, and A. lineatus were significantly corrected with the water temperature.

2006~2010년 기간 동안 대한해협 서수도에서 관측된 해수 물성의 변동 (Observation of Water Property Variations in the Western Channel of the Korea Strait During 2006-2010)

  • 민홍식;박재훈;최아라;박영규;신경순;장풍국
    • Ocean and Polar Research
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    • 제33권spc3호
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    • pp.325-336
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    • 2011
  • Seasonal to inter-annual variations of water properties in the western channel of the Korea Strait are investigated using quasi-monthly hydrographic observations collected during 2006-2010. Weak vertical temperature and salinity gradients are observed during the winter months and these remain until May. At the upper layer, temperature increases from March and reaches a maximum in August, while salinity decreases during the same period. Near-bottom water shows low temperatures during late winter and fall with a minimum peak in September. Korea Strait Bottom Cold Water produces thick layers (>20 m) in 2006 and 2010, while it is observed very near the bottom with relatively high temperature in 2008 and 2009.

물수요 중심 용수공급시스템 활용을 위한 국내 농업용수 공급체계 분석 (Analysis of Agricultural Water Distribution Systems for the Utilization of Water-Demand-Oriented Water Supply Systems)

  • 이광야;최경숙
    • Current Research on Agriculture and Life Sciences
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    • 제31권2호
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    • pp.139-147
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    • 2013
  • This study analyzed agricultural water distribution systems for the utilization of water demand-oriented water supply systems. Three major TM/TC(telemeter/telecontrol) districts of agricultural water management were selected for analyzing the characteristics of the water distribution systems. In addition, the characteristics of the water supply systems for general water supply zones based on irrigation facilities were also investigated, along with the case of special water management during the drought season. As a result, high annual and monthly variations were observed for the water supply facilities, including the reservoirs and pumping stations. In particular, these variations were more obvious during the drought season, depending on the type of facility. The operations of the pumping stations and weirs were more sensitive to the stream levels than the reservoirs, and the smaller reservoirs were influenced more than the larger reservoirs. Therefore, a water-demand-oriented water supply system should consider the existing general practices of water management in the agricultural sector, and focus on achieving a laborsaving system rather than water conservation in the case of reservoirs. Equal water distribution from the start to the end point of irrigation channels could be an effective solution for managing pumping stations.

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MULTISPECTRAL REMOTE SENSING ALGORITHMS FOR PARTICULATE ORGANIC CARBON (POC) AND ITS TEMPORAL AND SPATIAL VARIATION

  • Son, Young-Baek;Wang, Meng-Hua;Gardner, Wilford D.
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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    • pp.450-453
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    • 2006
  • Hydrographic data including particulate organic carbon (POC) from the Northeastern Gulf of Mexico (NEGOM) study were used along with remotely sensed data obtained from NASA's Sea-viewing Wide Field-of-view Sensor (SeaWiFS) to develop POC algorithms to estimate POC concentration based on empirical and model-based principal component analysis (PCA) methods. In Case I and II waters empirical maximized simple ratio (MSR) and model-based PCA algorithms using full wavebands (blue, green and red wavelengths) provide more robust estimates of POC. The predicted POC concentrations matched well the spatial and seasonal distributions of POC measured in situ in the Gulf of Mexico. The ease in calculating the MSR algorithm compared to PCA analysis makes MSR the preferred algorithm for routine use. In order to determine the inter-annual variations of POC, MSR algorithms applied to calculate 100 monthly mean values of POC concentrations (September 1997-December 2005). The spatial and temporal variations of POC and sea surface temperature (SST) were analyzed with the empirical orthogonal function (EOF) method. POC estimates showed inter-annual variation in three different locations and may be affected by El $Ni{\tilde{n}}o/Southern$ Oscillation (ENSO) events.

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