• 제목/요약/키워드: NNM

검색결과 33건 처리시간 0.036초

하천유역에서 기후변화에 따른 이상호우시의 최적 수문예측시스템 (The Optimal Hydrologic Forecasting System for Abnormal Storm due to Climate Change in the River Basin)

  • 김성원;김형수
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2008년도 학술발표회 논문집
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    • pp.2193-2196
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    • 2008
  • In this study, the new methodology such as support vector machines neural networks model (SVM-NNM) using the statistical learning theory is introduced to forecast flood stage in Nakdong river, Republic of Korea. The SVM-NNM in hydrologic time series forecasting is relatively new, and it is more problematic in comparison with classification. And, the multilayer perceptron neural networks model (MLP-NNM) is introduced as the reference neural networks model to compare the performance of SVM-NNM. And, for the performances of the neural networks models, they are composed of training, cross validation, and testing data, respectively. From this research, we evaluate the impact of the SVM-NNM and the MLP-NNM for the forecasting of the hydrologic time series in Nakdong river. Furthermore, we can suggest the new methodology to forecast the flood stage and construct the optimal forecasting system in Nakdong river, Republic of Korea.

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비선형 분리모형에 의한 증발접시 증발량의 해석 (Pan Evaporation Analysis using Nonlinear Disaggregation Model)

  • 김성원;김정헌;박기범
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2008년도 학술발표회 논문집
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    • pp.1147-1150
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    • 2008
  • The goal of this research is to apply the neural networks models for the disaggregation of the pan evaporation (PE) data, Republic of Korea. The neural networks models consist of the support vector machines neural networks model (SVM-NNM) and multilayer perceptron neural networks model (MLP-NNM), respectively. The SVM-NNM in time series modeling is relatively new and it is more problematic in comparison with classifications. In this study, The disaggregation means that the yearly PE data divides into the monthly PE data. And, for the performances of the neural networks models, they are composed of training, cross validation, and testing data, respectively. From this research, we evaluate the impact of the SVM-NNM and the MLP-NNM for the disaggregation of the nonlinear time series data. We should, furthermore, construct the credible data of the monthly PE data from the disaggregation of the yearly PE data, and can suggest the methodology for the irrigation and drainage networks system.

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신경망기법을 이용한 수문학적 분해모형 (Hydrologic Disaggregation Model using Neural Networks Technique)

  • 김성원
    • 한국습지학회지
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    • 제12권3호
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    • pp.79-97
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    • 2010
  • 본 연구의 목적은 연 증발접시 증발량의 수문학적 분해를 위하여 신경망모형을 적용하는데 있다. 신경망 모형은 각각 다층 퍼셉트론 신경망모형(MLP-NNM)과 지지벡터기구 신경망모형(SVM-NNM)으로 구성되어 있다. 그리고 신경망모형의 수행평가를 위하여 훈련 및 테스트과정으로 구성되었다. 신경망모형의 훈련과정을 위하여 실측, 모의 및 혼합자료와 같은 세 가지 형태의 자료가 사용되었으며, 테스트과정을 위해서는 실측자료만 이용되었다. 평가를 위하여 4가지의 통계학적 지표(CC, RMSE, E, AARE)가 각각 제시되었으며, ANOVA 및 Mann-Whitney U 검증을 이용하여 실측 및 계산된 월 증발접시 증발량자료에 동질성검증을 실시하였다. 본 연구를 통하여 비선형 시계열자료의 수문학적 분해를 위해서 MLP-NNM과 SVM-NNM의 적용성을 평가하였다. 게다가 연 증발접시 증발량 자료의 수문학적 분해로부터 신뢰성있는 월 증발접시 증발량자료를 구축할 수 있을 것이며, 관개배수 네트워크 시스템의 평가를 위한 이용가능한 자료를 제공할 수 있을 것이다.

PNA를 이용한 일 기준증발산량의 모형화 (Modeling of Daily Reference Evapotranspiration using Polynomial Networks Approach (PNA))

  • 김성원
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2011년도 학술발표회
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    • pp.473-473
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    • 2011
  • Group method of data handling neural networks model (GMDH-NNM) is used to estimate daily reference evapotranspiration (ETo) using limited climatic variables such as max temperature ($T_{max}$), min temperature ($T_{min}$), mean wind speed ($W_{mean}$), mean relative humidity ($RH_{mean}$) and sunshine duration (SD). And, for the performances of GMDH-NNM, it consists of training and test performances, respectively. The training and test performances are carried out using daily time series data, respectively. From this research, we evaluate the impact of GMDH-NNM for the modeling of the nonlinear time series data. We should, thus, construct the credible data of the daily ETo data using GMDH-NNM, and can suggest the methodology for the irrigation and drainage networks system. Furthermore, this research represents that the strong nonlinear relationship such as ETo modeling can be generalized using GMDH-NNM.

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제한된 기상변수와 Polynomial Networks Approach를 이용한 일 증발접시 증발량의 모형화 (Modeling of Daily Pan Evaporation using the Limited Climatic Variables and Polynomial Networks Approach)

  • 김성원
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2010년도 학술발표회
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    • pp.1596-1599
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    • 2010
  • Group method of data handling neural networks model (GMDH-NNM) is used to estimate daily pan evaporation (PE) using limited climatic variables such as max temperature ($T_{max}$), min temperature ($T_{min}$), mean wind speed ($W_{mean}$), mean relative humidity ($RH_{mean}$) and sunshine duration (SD). And, for the performances of GMDH-NNM, it is composed of training and test performances, respectively. The training and test performances are carried out using daily time series data, respectively. From this research, we evaluate the impact of GMDH-NNM for the modeling of the nonlinear time series data. We should, thus, construct the credible data of the daily PE data using GMDH-NNM, and can suggest the methodology for the irrigation and drainage networks system. Furthermore, this research represents that the strong nonlinear relationship such as pan evaporation modeling can be generalized using GMDH-NNM.

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SVM-NNM을 이용한 증발접시 증발량자료의 분해기법 (Disaggregation Approach of the Pan Evaporation using SVM-NNM)

  • 김성원
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2010년도 학술발표회
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    • pp.1560-1563
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    • 2010
  • The goal of this research is to apply the neural networks model for the disaggregation of the pan evaporation (PE) data, Republic of Korea. The neural networks model consists of support vector machine neural networks model (SVM-NNM). The disaggregation means that the yearly PE data divides into the monthly PE data. And, for the performances of the neural networks model, it is composed of training and test performances, respectively. The training and test performances consist of the historic, the generated, and the mixed data, respectively. From this research, we evaluate the impact of SVM-NNM for the disaggregation of the nonlinear time series data. We should, furthermore, construct the credible data of the monthly PE from the disaggregation of the yearly PE data, and can suggest the methodology for the irrigation and drainage networks system.

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지지벡터기구를 이용한 월 강우량자료의 Downscaling 기법 (Downscaling Technique of the Monthly Precipitation Data using Support Vector Machine)

  • 김성원;경민수;권현한;김형수
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2009년도 학술발표회 초록집
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    • pp.112-115
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    • 2009
  • The research of climate change impact in hydrometeorology often relies on climate change information. In this paper, neural networks models such as support vector machine neural networks model (SVM-NNM) and multilayer perceptron neural networks model (MLP-NNM) are proposed statistical downscaling of the monthly precipitation. The input nodes of neural networks models consist of the atmospheric meteorology and the atmospheric pressure data for 2 grid points including $127.5^{\circ}E/35^{\circ}N$ and $125^{\circ}E/35^{\circ}N$, which produced the best results from the previous study. The output node of neural networks models consist of the monthly precipitation data for Seoul station. For the performances of the neural networks models, they are composed of training and test performances, respectively. From this research, we evaluate the impact of SVM-NNM and MLP-NNM performances for the downscaling of the monthly precipitation data. We should, therefore, construct the credible monthly precipitation data for Seoul station using statistical downscaling method. The proposed methods can be applied to future climate prediction/projection using the various climate change scenarios such as GCMs and RCMs.

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Application of Soft Computing Model for Hydrologic Forecasting

  • Kim, Sung-Won;Park, Ki-Bum
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2012년도 학술발표회
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    • pp.336-339
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    • 2012
  • Accurate forecasting of pan evaporation (PE) is very important for monitoring, survey, and management of water resources. The purpose of this study is to develop and apply Kohonen self-organizing feature maps neural networks model (KSOFM-NNM) to forecast the daily PE for the dry climate region in south western Iran. KSOFM-NNM for Ahwaz station was used to forecast daily PE on the basis of temperature-based, radiation-based, and sunshine duration-based input combinations. The measurements at Ahwaz station in south western Iran, for the period of January 2002 - December 2008, were used for training, cross-validation and testing data of KSOFM-NNM. The results obtained by TEM 1 produced the best results among other combinations for Ahwaz station. Based on the comparisons, it was found that KSOFM-NNM can be employed successfully for forecasting the daily PE from the limited climatic data in south western Iran.

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뉴럴네트워크 모델 기반의 IPMC 셀프 센싱 액추에이터 (Self-Sensing Actuator Using an Ion-Polymer Metal Composite Based on a Neural Network Model)

  • 윤종일;딩광졍;안경관
    • 대한기계학회논문집A
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    • 제34권12호
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    • pp.1865-1870
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    • 2010
  • 이 논문에서는 뉴럴네트워크 모델에 기초하여 셀프 센싱이 가능한 IPMC 액추에이터를 개발하고자 한다. IPMC의 양면에 있는 두 개의 지정된 점에서 측정된 입력 전압과 입력 신호들을 뉴럴네트워크 모델의 입력 신호로 사용한다. CCD 레이저 변위 센서는 제시된 뉴럴네트워크 모델의 학습된 출력값으로 사용되는 IPMC 끝의 변위를 정확히 측정하기 위해 설치된다. 결과적으로 뉴럴네트워크 모델은 수집된 입력/출력 학습데이터에 의해 최대한으로 활용된 IPMC의 끝의 변위를 평가하기 위해 만들어진다. IPMC 액추에이터를 위해 설계된 모델의 효율성은 결과들을 모델링함으로서 증명되어진다.

A Case-Control Study on the Predictors of Neonatal Near-Miss: Implications for Public Health Policy and Practice

  • Johnson, Avita Rose;Sunny, Sobin;Nikitha, Ramola;Thimmaiah, Sulekha;Rao, Suman P.N.
    • Neonatal Medicine
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    • 제28권3호
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    • pp.124-132
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    • 2021
  • Purpose: Neonatal near miss (NNM) allows for the detection of risk factors associated with serious newborn complications and death, the prevention of which could reduce neonatal mortality. This study was conducted with the objective of identifying predictors for NNM in a tertiary hospital in Bangalore city. Methods: This was an unmatched case-control study involving 120 NNM cases and 120 controls. NNM was determined using Pileggi-Castro's pragmatic and management criteria. Data was collected from in-patient hospital records and interviews of postpartum mothers. Multiple logistic regression of exposure variables was performed to calculate adjusted odds ratio (AOR) with 95% confidence interval (CI). Results: Significant predictors were maternal age ≥30 years (AOR, 5.32; 95% CI, 1.12 to 9.29; P=0.041), inadequate antenatal care (ANC) (AOR, 8.35; 95% CI, 1.98 to 51.12; P=0.032), <3 ultrasound scans during pregnancy (AOR, 12.5; 95% CI, 1.60 to 97.27; P=0.016), maternal anaemia (AOR, 18.96; 95% CI, 3.10 to 116.02; P=0.001), and any one obstetric complication (hypertensive disorder in pregnancy, diabetes in pregnancy, preterm premature rupture of membranes, prolonged labour, obstructed labour, malpresentation) (AOR, 4.34; 95% CI, 1.26 to 14.95; P=0.02). Conclusion: The predictors of NNM identified has important implications for public health policy and practice whose modifications can improve NNM. These include expanding essential ANC package to include ultrasound scans, ensuring World Health Organization recommendations of eight ANC visits, capacity building at all levels of health care to strengthen routine ANC and obstetric care for effective screening, referral and management of obstetric complications.