• 제목/요약/키워드: Seasonal development

검색결과 848건 처리시간 0.032초

계절에 따른 농촌 지역 하수종말처리장의 처리 효율 변화 (Changes of Treatment Efficiency According to Seasonal Variation in Rural Area)

  • 임지열;길경익
    • 한국습지학회지
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    • 제17권3호
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    • pp.311-319
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    • 2015
  • 국토의 균형적인 개발과 수계 수질 보호를 목적으로 한국 정부는 농촌 지역 하수도 보급 사업을 진행하고 있다. 본 연구는 농촌 지역 하수도 보급 사업의 하나인 A 하수종말처리장의 연간 운전결과를 분석하였다. 농촌 지역 하수종말처리장 유입 하수 농도는 계절에 따라 변화하며, 여름철에 가장 낮은 것으로 나타났다. 계절 변화에 따른 생물반응조의 처리 효율은 유기물질에 비해 영양염류가 계절에 따라 처리 효율의 변화가 큰 것으로 나타났으며 겨울철에 가장 낮은 것으로 나타났다. 또한 영양염류는 체류시간과 F/M ratio에 대해 유기물보다 민감하게 반응한 결과를 보였다. 농촌 지역 하수종말처리장 공법 선정 시 계절에 따라 변화하는 유입 하수의 특성을 고려해야 한다. 또한 겨울철 영양염류의 안정적인 처리 효율을 위한 유지관리가 필요하다.

빙권요소를 활용한 겨울철 역학 계절예측 시스템의 개발 및 검증 (Development and Assessment of Dynamical Seasonal Forecast System Using the Cryospheric Variables)

  • 심태현;정지훈;옥정;정현숙;김백민
    • 대기
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    • 제25권1호
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    • pp.155-167
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    • 2015
  • A dynamical seasonal prediction system for boreal winter utilizing cryospheric information was developed. Using the Community Atmospheric Model, version3, (CAM3) as a modeling system, newly developed snow depth initialization method and sea ice concentration treatment were implemented to the seasonal prediction system. Daily snow depth analysis field was scaled in order to prevent climate drift problem before initializing model's snow fields and distributed to the model snow-depth layers. To maximize predictability gain from land surface, we applied one-month-long training procedure to the prediction system, which adjusts soil moisture and soil temperature to the imposed snow depth. The sea ice concentration over the Arctic region for prediction period was prescribed with an anomaly-persistent method that considers seasonality of sea ice. Ensemble hindcast experiments starting at 1st of November for the period 1999~2000 were performed and the predictability gain from the imposed cryospheric informations were tested. Large potential predictability gain from the snow information was obtained over large part of high-latitude and of mid-latitude land as a result of strengthened land-atmosphere interaction in the modeling system. Large-scale atmospheric circulation responses associated with the sea ice concentration anomalies were main contributor to the predictability gain.

일별, 월별 의도적 자해의 사망 양상에 관한 연구: 2011 인구동태동계자료 중심으로 (Daily and Monthly Death Pattern an Intentional Self-harm by Hanging, Strangulation and Suffocation in Korea, 2011)

  • 박상화;임달오
    • 보건행정학회지
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    • 제23권3호
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    • pp.260-265
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    • 2013
  • Background: The aim of this study was to examine the seasonal variation of death from intentional self-harm by hanging, strangulation and suffocation (HSS: Korean Standard Classification of Diseases-6 code: X70) using the 2011 death registry data. Methods: The analysis was based on data of 8,359 HSS deaths from 2011 national vital statistics in Korea. Daily, weekly, and monthly death pattern on HSS were used to examine the relationship seasonal variation and HSS deaths. Results: A total of 8,359 HSS deaths occurred in 2011, with a mean age of 50.6 years. The HSS death rate (per 100,000) was 25.5 in male and 10.8 in female. In one day 17.6 males and 8.0 females occurred HSS death on average. The number of HSS death per day was the highest on 8th June (45 deaths), and lowest on 1st February (7 deaths) during the period. The variations of daily HSS death showed wide fluctuation from a peak of 34 to 45 deaths (29th May to 9th June) to a trough of 17-26 deaths (10th-13th September: the Korean thank-giving consecutive holidays), 13-20 deaths (2nd-5th February: the new year's day by the lunar calendar) and 8-9 deaths (24th-25th December: Christmas holidays). There were no significant difference between gender and seasonal variation (month, season, and week). Conclusion: The mean number of HSS death per day was highest in June (30.6 deaths), and months with the lowest number of deaths was January and December (range, 19.4 to 19.6 deaths). HSS death were more prevalent during summer and spring and were less likely to occur during winter. On Saturdays (21.0 deaths), the number of HSS death per day was the lowest, and Monday (27.9 deaths) was the highest. HSS death was less likely to occur on holidays (21.4 deaths). There was significant seasonal variation in HSS death by weekly and monthly (p<0.01).

발생학습 전략의 적용이 계절변화 관련 지구과학개념 변화에 미친 효과 (The Effects on Earth Science Concepts about Seasonal Changes by Generative Learning Strategy)

  • 정진우;윤상화;이항로
    • 한국지구과학회지
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    • 제24권3호
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    • pp.160-171
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    • 2003
  • 본 연구에서는 계절 변화에 관련된 개념 유형을 분석하고, 관련 개념들에 관한 토의에 의해 인지갈등을 해소하는 방법을 강조한 발생학습 전략의 적용 효과를 알아보고자 하였다. 계절변화 관련 지구과학 개념 유형은 100가지 였으며, 그 중에서 66가지는 오개념을 포함한 비과학적 개념 유형이었다. 계절변화에 관련된 개념 평가도구는 R&D과정과 2번의 현장검증을 거쳐 개발되었다. 실험집단에는 지구과학개념 유형과 인지갈등을 반영한 4단계의 발생학습 전략을 적용하였다. 한편 통제집단에는 전통적인 교수 학습 전략을 적용하였다. 유의수준 .05에서 공변량분석을 실시한 결과 두 집단 간에는 유의미한 차이가 있는 것으로 나타났다. 이러한 연구 결과는 계절변화와 관련된 오개념을 지구과학적 개념으로 변화시키는 데 발생학습전략이 하나의 가능한 대안이 될 수 있음을 의미하는 것으로 볼 수 있다.

Assessment of Seasonal Variations in the Treatment Efficiency of Constructed Wetlands

  • Reyes, Nash Jett DG.;Geronimo, Franz Kevin F.;Choi, Hyeseon;Jeon, Minsu;Kim, Lee-Hyung
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2020년도 학술발표회
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    • pp.231-231
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    • 2020
  • Unlike conventional treatment technologies, the performance of nature-based facilities were susceptible to seasonal changes and climatological variabilities. This study evaluated the effects of seasonal variables on the treatment performance of constructed wetlands (CWs). Two CWs treating runoff and discharge from agricultural and livestock areas were monitored to determine the efficiency of the systems in reducing particulates, organics, and nutrients in the influent. For all four seasons, the mean effluent suspended solids concentration in the agricultural CW (ACW) increased by -2% to -39%. The occurrence of algal blooms in the system during summer and fall seasons resulted to the greatest increase in the amount of suspended materials in the overlying water. unlike ACW, the livestock CW (LCW) performed efficiently throughout the year, with mean suspended solids removal amounting to 61% to 68%. Algal blooms were still present in LCW seasonally; however, the constant inflow in the system limited the proliferation of phytoplankton through continuous flushing. The total nitrogen (TN) and total phosphorus (TP) removal efficiencies in ACW were higher during the summer (21% to 25%) and fall (8% to 21%) seasons since phytoplankton utilize nitrogen and phosphorus during the early stages of phytoplankton blooms. In the case of LCW, the most efficient reduction in TN (24%) and TP (54%) concentrations were also noted in summer, which can be attributed to the favorable environmental conditions for microbial activities. The mean removal of organics in ACW was lowest during summer season (-52% to 35%), wherein the onset of algal decay triggered a relative increase in organic matter and stimulate bacterial growth. The removal of organics in LCW was highest (54 % to 55%) during the fall and winter seasons since low water temperatures may limit the persistence of various algal species. Variations in environmental conditions due to seasonal changes can greatly affect the performance of CW systems. This study effectively established the contributory factors affecting the feasibility of utilizing CW systems for treating agricultural and livestock discharges and runoff.

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Improving SARIMA model for reliable meteorological drought forecasting

  • Jehanzaib, Muhammad;Shah, Sabab Ali;Son, Ho Jun;Kim, Tae-Woong
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2022년도 학술발표회
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    • pp.141-141
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    • 2022
  • Drought is a global phenomenon that affects almost all landscapes and causes major damages. Due to non-linear nature of contributing factors, drought occurrence and its severity is characterized as stochastic in nature. Early warning of impending drought can aid in the development of drought mitigation strategies and measures. Thus, drought forecasting is crucial in the planning and management of water resource systems. The primary objective of this study is to make improvement is existing drought forecasting techniques. Therefore, we proposed an improved version of Seasonal Autoregressive Integrated Moving Average (SARIMA) model (MD-SARIMA) for reliable drought forecasting with three years lead time. In this study, we selected four watersheds of Han River basin in South Korea to validate the performance of MD-SARIMA model. The meteorological data from 8 rain gauge stations were collected for the period 1973-2016 and converted into watershed scale using Thiessen's polygon method. The Standardized Precipitation Index (SPI) was employed to represent the meteorological drought at seasonal (3-month) time scale. The performance of MD-SARIMA model was compared with existing models such as Seasonal Naive Bayes (SNB) model, Exponential Smoothing (ES) model, Trigonometric seasonality, Box-Cox transformation, ARMA errors, Trend and Seasonal components (TBATS) model, and SARIMA model. The results showed that all the models were able to forecast drought, but the performance of MD-SARIMA was robust then other statistical models with Wilmott Index (WI) = 0.86, Mean Absolute Error (MAE) = 0.66, and Root mean square error (RMSE) = 0.80 for 36 months lead time forecast. The outcomes of this study indicated that the MD-SARIMA model can be utilized for drought forecasting.

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경상남도 창원시 산남저수지에서 삼각망으로 채집된 어류의 계절별 종조성 (Seasonal Variation in Species Composition of Fishes Collected by a Three Sided Fyke Net from Sannam Reservoir in Changwon-si, Gyeongsangnam-do)

  • 김경률;박종혁;박종식;최문성;이대현;백근욱
    • 한국수산과학회지
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    • 제52권6호
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    • pp.745-751
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    • 2019
  • Seasonal variation in species composition of fishes in the Sannam reservoir in Changwon, Korea was determined using samples collected by a three-sided fyke net in 2018. During the study period, we collected 2,181 individuals of 9 species, with a total weight of 111,552.2 g. The dominant species were Lepomis macrochirus, Carassius carassius, Erythroculter erythropterus, and Cyprinus carpio. These species accounted for 96.1% of the total number of individuals. The number of fish species, number of individuals, biomass and species diversity indices fluctuated with the seasons. The peak number of fish species occurred in May and August, the biomass of fishes was highest in May. Whereas the number of individuals was highest in February.

Gonadal Maturation and Main Spawning Period of Haliotis gigantea (Gastropoda: Haliotidae)

  • Shin, So Ryung;Kim, Hyeon Jin;Lee, Dong Han;Kim, Hyejin;Sohn, Young Chang;Kim, Jae Won;Lee, Jung Sick
    • 한국발생생물학회지:발생과생식
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    • 제24권2호
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    • pp.79-88
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    • 2020
  • This study was carried out to obtain information on the developmental biology and the management of biological resources of the abalone Haliotis gigantea in Korea. The sex ratio (female:male) in the present study was 1:1.7 and the proportion of females was 36.6% (n=106/290). Their gonadal structures displayed definitive seasonal changes which were similar in pattern to the changes in the gonad index (GI). The GI showed a pattern of definitive seasonal changes in both males and females it was high in the fall and low in the spring. The reproductive cycle could be categorized into the following six stages: inactive, early active, late active, ripe, spent, and degenerative stage. Based on the monthly changes in GI and stages of gonadal development, October to November was determined to be the main spawning period for H. gigantea on Jeju Island, Korea.