• 제목/요약/키워드: quantitative models

검색결과 1,016건 처리시간 0.033초

미국 고등학습위원회 기관평가인증제 평가모형 개혁의 시사점에 관한 연구 (A Study on the Implication from Reform of HLC Institutional Accreditation Model)

  • 이영학
    • 비교교육연구
    • /
    • 제24권3호
    • /
    • pp.245-265
    • /
    • 2014
  • 본 연구는 미국 북중미학교기관협의회 산하 고등학습위원회의 기관평가인증제 평가모형 개혁에 따른 시사점 분석을 통해 한국의 제2주기 기관평가인증제 평가모형 수립에 대해 제언하는 것을 목적으로 수행되었다. 이를 위해 기관평가인증제 평가모형의 주요 요소인 인증모형, 인증 주기 및 종합평가, 평가준거, 결과판정, 인증지원시스템을 중심으로 고등학습위원회 및 한국대학평가원의 기관평가인증제를 비교 분석하였으며, 분석 결과를 바탕으로 한국의 제2주기 기관평가인증제 시행과 관련하여 다음과 같이 제언하였다. 첫째, 대학의 특성과 질 수준 차이를 반영한 다양한 인증모형을 개발하여 적용할 필요가 있다. 둘째, 최소 수준 질 인증과 함께 기관의 지속적인 질 제고를 유도하는 평가가 필요하다. 셋째, 대학 사명에 근거한 평가를 강화하고 정량적 평가를 최소화하며 평가위원 풀을 확대하고 교육훈련을 강화해야 한다. 넷째, 질 제고 강화를 위해 중간평가를 엄격하게 시행할 필요가 있다. 다섯째, 정부는 기관평가인증제 결과를 대학구조조정 등에 적극적으로 반영해야 한다. 여섯째, 기관평가인증제를 관리하는 시스템 구축 및 대학정보공시제와 연동이 필요하다.

Calibration of APEX-Paddy Model using Experimental Field Data

  • Mohammad, Kamruzzaman;Hwang, Syewoon;Cho, Jaepil;Choi, Soon-Kun;Park, Chanwoo
    • 한국수자원학회:학술대회논문집
    • /
    • 한국수자원학회 2019년도 학술발표회
    • /
    • pp.155-155
    • /
    • 2019
  • The Agricultural Policy/Environmental eXtender (APEX) models have been developed for assessing agricultural management efforts and their effects on soil and water at the field scale as well as more complex multi-subarea landscapes, whole farms, and watersheds. National Academy of Agricultural Sciences, Wanju, Korea, has modified a key component of APEX application, named APEX-Paddy for simulating water quality with considering appropriate paddy management practices, such as puddling and flood irrigation management. Calibration and validation are an anticipated step before any model application. Simple techniques are essential to assess whether or not a parameter should be adjusted for calibration. However, very few study has been done to evaluate the ability of APEX-Paddy to simulate the impact of multiple management scenarios on nutrients loss. In this study, the observation data from experimental fields at Iksan in South Kora was used in calibration and evaluation process during 2013-2015. The APEX auto- calibration tool (APEX-CUTE) was used for model calibration and sensitivity analysis. Four quantitative statistics, the coefficient of determination ($R^2$),Nash-Sutcliffe(NSE),percentbias(PBIAS)androotmeansquareerror(RMSE)were used in model evaluation. In this study, the hydrological process of the modified model, APEX-Paddy, is being calibrated and tested in predicting runoff discharge rate and nutrient yield. Field-scale calibration and validation processes are described with an emphasis on essential calibration parameters and direction regarding logical sequences of calibration steps. This study helps to understand the calibration and validation way is further provided for applications of APEX-Paddy at the field scales.

  • PDF

Relative contributions of weather systems to the changes of annual and extreme precipitation with global warming

  • Utsumi, Nobuyuki;Kim, Hyungjun;Kanae, Shinjiro;Oki, Taikan
    • 한국수자원학회:학술대회논문집
    • /
    • 한국수자원학회 2015년도 학술발표회
    • /
    • pp.234-234
    • /
    • 2015
  • The global patterns of annual and extreme precipitation are projected to be altered by climate change. There are various weather systems which bring precipitation (e.g. tropical cyclone, extratropical cyclone, etc.). It is possible in some regions that multiple weather systems affect the changes of precipitation. However, previous studies have assessed only the changes of precipitation associated with individual weather systems. The relative contributions of the weather systems to the changes of precipitation have not been quantified yet. Also, the changes of the relative importance of weather systems have not been assessed. This study present the quantitative estimates of 1) the relative contributions of weather systems (tropical cyclone (TC), extratropical cyclone (ExC), and "others") to the future changes of annual and extreme precipitation and 2) the changes of the proportions of precipitation associated with each weather system in annual and extreme precipitation based on CMIP5 generation GCM outputs. Weather systems are objectively detected from twelve GCM outputs and six models are selected for further analysis considering the reproducibility of weather systems. In general, the weather system which is dominant in terms of producing precipitation in the present climate contributes the most to the changes of annual and extreme precipitation in each region. However, there are exceptions for the tendency. In East Asia, "others", which ranks the second in the proportion of annual precipitation in present climate, has the largest contribution to the increase of annual precipitation. It was found that the increase of the "others" annual precipitation in East Asia is mainly explained by the changes of that in summer season (JJA), most of which can be regarded as the summer monsoon precipitation. In Southeast Asia, "others" precipitation, the second dominant system in the present climate, has the largest contribution to the changes of very heavy precipitation (>99.9 percentile daily precipitation of historical period). Notable changes of the proportions of precipitation associated with each weather system are found mainly in subtropics, which can be regarded as the "hotspot" of the precipitation regime shift.

  • PDF

파키스탄 밀-옥수수 재배시스템의 기후변화를 반영한 필요수량 산정 (Projecting the climatic influences on the water requirements of wheat-rice cropping system in Pakistan)

  • 미르자 주네드 아흐메드;최경숙
    • 한국수자원학회:학술대회논문집
    • /
    • 한국수자원학회 2018년도 학술발표회
    • /
    • pp.486-486
    • /
    • 2018
  • During the post green revolution era, wheat and rice were the main crops of concern to cater the food security issues of Pakistan. The use of semi dwarf high yielding varieties along with extensive use of fertilizers and surface and ground water lead to substantial increase in crop production. However, the higher crop productivity came at the cost of over exploitation of the precious land and water resources, which ultimately has resulted in the dwindling production rates, loss of soil fertility, and qualitative and quantitative deterioration of both surface and ground water bodies. Recently, during the past two decades, severe climate changes are further pushing the Pakistan's wheat-rice system towards its limits. This necessitates a careful analysis of the current crop water requirements and water footprints (both green and blue) to project the future trends under the most likely climate change phenomenon. This was done by using the FAO developed CROPWAT model v 8.0, coupled with the statistically-downscaled climate projections from the 8 Global Circulation Models (GCMs), for the two future time slices, 2030s (2021-2050) and 2060s (2051-2080), under the two Representative Concentration Pathways (RCPs): 4.5 and 8.5. The wheat-rice production system of Punjab, Pakistan was considered as a case study in exploration of how the changing climate might influence the crop water requirements and water footprints of the two major crops. Under the worst, most likely future scenario of temperature rise and rainfall reduction, the crop water requirements and water footprints, especially blue, increased, owing to the elevated irrigation demands originating from the accelerated evapotranspiration rates. A probable increase in rainfall as envisaged by some GCMs may partly alleviate the adverse impacts of the temperature rise but the higher uncertainties associated with the predicated rainfall patterns is worth considering before reaching a final conclusion. The total water footprints were continuously increasing implying that future climate would profoundly influence the crop evapotranspiration demands. The results highlighted the significance of the irrigation water availability in order to sustain and improve the wheat-rice production system of Punjab, Pakistan.

  • PDF

Vision-based dense displacement and strain estimation of miter gates with the performance evaluation using physics-based graphics models

  • Narazaki, Yasutaka;Hoskere, Vedhus;Eick, Brian A.;Smith, Matthew D.;Spencer, Billie F.
    • Smart Structures and Systems
    • /
    • 제24권6호
    • /
    • pp.709-721
    • /
    • 2019
  • This paper investigates the framework of vision-based dense displacement and strain measurement of miter gates with the approach for the quantitative evaluation of the expected performance. The proposed framework consists of the following steps: (i) Estimation of 3D displacement and strain from images before and after deformation (water-fill event), (ii) evaluation of the expected performance of the measurement, and (iii) selection of measurement setting with the highest expected accuracy. The framework first estimates the full-field optical flow between the images before and after water-fill event, and project the flow to the finite element (FE) model to estimate the 3D displacement and strain. Then, the expected displacement/strain estimation accuracy is evaluated at each node/element of the FE model. Finally, methods and measurement settings with the highest expected accuracy are selected to achieve the best results from the field measurement. A physics-based graphics model (PBGM) of miter gates of the Greenup Lock and Dam with the updated texturing step is used to simulate the vision-based measurements in a photo-realistic environment and evaluate the expected performance of different measurement plans (camera properties, camera placement, post-processing algorithms). The framework investigated in this paper can be used to analyze and optimize the performance of the measurement with different camera placement and post-processing steps prior to the field test.

비선형 탄성 다점지지 베어링 요소를 이용한 선미관 베어링의 유효지지점 검증 (Verification of Effective Support Points of Stern Tube Bearing Using Nonlinear Elastic Multi-Support Bearing Elements)

  • 정준모;최익흥;김규창
    • 대한조선학회논문집
    • /
    • 제42권5호
    • /
    • pp.479-486
    • /
    • 2005
  • The final goal of shift alignment design is that the bearing reaction forces or mean pressures are within design boundaries for various service conditions of a ship. However, it is found that calculated bearing load can be substantially variable according to the locations of the effective support points of after sterntube bearing which are determined by simple calculation or assumption suggested by classification societies. A new analysis method for shaft alignment calculation is introduced in order to resolve these problems. Key concept of the new method is featured by adopting both nonlinear elastic and multi-support elements to simulate a bearing support Hertz contact theory is basically applied for nonlinear elastic stiffness calculation instead of the projected area method suggested by most of classification societies. Three loading conditions according to the bearing offset and the hydrodynamic moment and twelve models according to the locations of the effective support points of sterntube bearings are prepared to carry out quantitative verifications for an actual shafting system of 8000 TEU class container vessel. It is found that there is relatively large difference between assumed and calculated effective support points.

풍력예보를 위한 단순 앙상블예측시스템 - 태풍 볼라벤 사례를 통한 평가 - (A Simple Ensemble Prediction System for Wind Power Forecasting - Evaluation by Typhoon Bolaven Case -)

  • 김진영;김현구;강용혁;윤창열;김지영;이준신
    • 한국태양에너지학회 논문집
    • /
    • 제36권1호
    • /
    • pp.27-37
    • /
    • 2016
  • A simple but practical Ensemble Prediction System(EPS) for wind power forecasting was developed and evaluated using the measurement of the offshore meteorological tower, HeMOSU-1(Herald of Meteorological and Oceanographic Special Unite-1) installed at the Southwest Offshore in South Korea. The EPS developed by the Korea Institute of Energy Research is based on a simple ensemble mean of two Numerical Weather Prediction(NWP) models, WRF-NMM and WRF-ARW. In addition, the Kalman Filter is applied for real-time quality improvement of wind ensembles. All forecasts with EPS were analyzed in comparison with the HeMOSU-1 measurements at 97 m above sea level during Typhoon Bolaven episode in August 2012. The results indicate that EPS was in the best agreement with the in-situ measurement regarding (peak) wind speed and cut-out speed incidence. The RMSE of wind speed was 1.44 m/s while the incidence time lag of cut-out wind speed was 0 hour, which means that the EPS properly predicted a development and its movement. The duration of cut-out wind speed period by the EPS was also acceptable. This study is anticipated to provide a useful quantitative guide and information for a large-scale offshore wind farm operation in the decision making of wind turbine control especially during a typhoon episode.

유기탄소 실시간 모니터링을 위한 분광학적 특성인자 분석 (Analysis of Optical Properties of Organic Carbon for Real-time Monitoring)

  • 유영민;박종관;이병준;이승윤
    • 한국물환경학회지
    • /
    • 제37권5호
    • /
    • pp.344-354
    • /
    • 2021
  • Optical methods such as UV and fluorescence spectrophotometers can be applied not only in the qualitative analysis of dissolved organic matter (DOM), but also in real-time quantitative DOM monitoring for wastewater and natural water. In this study, we measure the UV254 and fluorescence excitation emission spectra for a sewage treatment plant influent and effluent, and river water before and after sewage effluent flows into the river to examine the composition and origin of DOM. In addition, a correlation analysis between quantified DOM characteristics and dissolved organic carbon (DOC) was conducted. Based on the fluorescence excitation emission spectra analysis, it was confirmed that the protein-type tryptophan-like DOM was the dominant substance in the influent, and that the organic matter exhibited relatively more humic properties after biological treatment. However, DOM in river water showed the fluorescence characteristics of terrestrial humic-like and algal tyrosine-like (protein-like) organic matter. In addition, a correlation analysis was conducted between the DOC and optical indices such as UV254, the fluorescence intensity of protein-like and humic-like organic matter, then DOC prediction models were suggested for wastewater and river monitoring during non-rainfall and rainfall events. This study provides basic information that can improve the understanding of the contribution of DOC concentration by DOM components, and can be used for organic carbon concentration management in wastewater and natural water.

Maxillary first molar wear: a longitudinal study of children

  • Kim, Won-Hee;Nam, Shin-Eun;Park, Young-Seok;Lee, Seung-Pyo
    • Anatomy and Cell Biology
    • /
    • 제51권4호
    • /
    • pp.251-259
    • /
    • 2018
  • The aim of this study is to examine the correlation between tooth wear and age by quantitatively measuring maxillary first molar wear in children. A total of 150 maxillary dental models were analyzed in 30 subjects (male, 11; female, 19) with an age range of 6-14 years. Maxillary first molar wear were assessed based on area, volume and the shortest distance from the buccal occlusal plane to the central pit point (BCPH). The area and volume of the tooth cusps were measured at four different offset-plane heights (0.2, 0.4, 0.6, and 0.8 mm). Relationship between age and the amount of wear or BCPH were statistically analyzed. Correlation and regression analyses were also performed, and age estimation was obtained with linear regression analysis. Repeated measures analysis of variance (ANOVA) revealed significant differences between age and the amount of wear based on area, volume, and offset-plane height. Except age of 8 and 10, 12 and 14's 0.2-mm offset-plane-measured volume, all area and volume measurement of all ages and offset-plane height showed a significant amount of increase. Wear speeds were calculated using the BCPH. Among age and measurement variables, the correlation coefficient was strongest when the volume was measured from the 0.4-mm offset-plane. As age increases, the amount of wear, as quantified by area and volume measurements, also increases. According to this study, a regression equation that can be used for age estimation is follows: Age $(y)=0.16{\times}0.4V+0.85$ ($R^2=0.490$) using volume.

소스 종류를 달리한 햄 주먹밥에서의 Staphylococcus aureus 성장예측모델 개발 및 위해평가 (Development of a Predictive Model and Risk Assessment for the Growth of Staphylococcus aureus in Ham Rice Balls Mixed with Different Sauces)

  • 오수진;여성순;김미숙
    • 대한영양사협회학술지
    • /
    • 제25권1호
    • /
    • pp.30-43
    • /
    • 2019
  • This study compared the predictive models for the growth kinetics of Staphylococcus aureus in ham rice balls. In addition, a semi-quantitative risk assessment of S. aureus on ham rice balls was conducted using FDA-iRISK 4.0. The rice was rounded with chopped ham, which was mixed with mayonnaise (SHM), soy sauce (SHS), or gochujang (SHG), and was contaminated artificially with approximately $2.5{\log}\;CFU{\cdot}g^{-1}$ of S. aureus. The inoculated rice balls were then stored at $7^{\circ}C$, $15^{\circ}C$, and $25^{\circ}C$, and the number of viable S. aureus was counted. The lag phases duration (LPD) and maximum specific growth rate (SGR) were calculated using a Baranyi model as a primary model. The growth parameters were analyzed using the polynomial equation as a function of temperature. The LPD values of S. aureus decreased with increasing temperature in SHS and SHG. On the other hand, those in SHM did not show any trend with increasing temperature. The SGR positively correlated with temperature. Equations for LPD and SGR were developed and validated using $R^2$ values, which ranged from 0.9929 to 0.9999. In addition, the total DALYs (disability adjusted life years) per year in the ham rice balls with soy sauce and gochujang was greater than mayonnaise. These results could be used to calculate the expected number of illnesses, and set the hazard management method taking the DALY value for public health into account.