• Title/Summary/Keyword: Quality of Predictions

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Stochastic Prediction of Strong Ground Motions and Attenuation Equations in the Southeastern Korean peninsular (한반도 동남부의 강진동 모사와 감쇠식)

  • 이정모
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2000.04a
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    • pp.70-80
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    • 2000
  • In order to reduce seismic hazard the characteristics of strong earthquakes are required. In the region where strong earthquakes do not happen frequently the stochastic simulation of strong motion is an alternative way to predict strong motions. this simulation required input parameters such as the quality factor the corner frequency the moment magnitude the stress drop and so on which can be obtained from analyses of records of small and intermediate earthquakes. Using those parameters obtained in the previous work the strong ground motions are predicted employing the stochastic method, . The results are compared to the two observed earthquakes-the Ulsan Offshore Earthquake and the Kyungju Earthquake. Although some deviations are found the predictions are similar to the observed data. Finally we computed attenuation equations for PGA PGV and ground accelerations for some frequencies using the results of predictions. These results can be used for earthquake engineering and more reliable results will come out as earthquake observations continue.

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Development of the wet and dry treatment using quadtree grids (사면구조 격자를 이용한 이동경계 기법 개발)

  • Kim, Jong-Ho;Lee, Seung-Oh;Cho, Yong-Sik
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.183-186
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    • 2008
  • All measures to cope with flooding rely on flood predictions to some extent, and the effectiveness of these measures is dependent on the quality of flood predictions. It is important to track properly the movements of the river-bankline in numerical modeling because the location of it varies continuously in the flood inundation. In this study, the wet and dry treatment is used to describe the moving river-bankline accurately (Cho, 1996). An oscillatory flow motion in a parabolic basin is used to validate the performance of the developed model based on quadtree grids. As a result of a simulation, a reasonable agreement is observed with analytical and Cho's results.

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A Comparison between the TCM and the CDMQC on Air Quality Prediction (대기오염 예측에서 TCM과 CDMQC의 비교)

  • 송동웅;김면섭;신응배
    • Journal of Korean Society for Atmospheric Environment
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    • v.3 no.1
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    • pp.34-40
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    • 1987
  • The Texas Climatological Model (TCM) Predicts long-term pollutant concentrations for a rectilinear array or receptors defined by the user. This paper describes the TCM and compares predictions from TCM with predictions from the Climatological Dispersion Model (CDMQC). A number of model runs have been made with the TCM and CDMQC using the same source inventories and sets of climatology. The concentrations predicted by these two models are compared and the result of several types of statistical analyses are reported. In most cases, the TCM predicts concentrations that are equivalent to those predicted by the CDMQC. However, in certain cases, the CDMQC tends to predict concentrations that are unrealistically high. In the computer time, the TCM requires about one-eights of the computer time used by the CDMQC.

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The Effects of Different Information Visualizations on Decision Quality in a Web Environment (웹 환경에서의 정보 시각화와 의사결정과의 상관관계)

  • Jung, Won-Jin
    • Journal of the Korean Operations Research and Management Science Society
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    • v.33 no.1
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    • pp.51-69
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    • 2008
  • Depending on the ways of information visualization, information can be interpretable, easy to understand, and represented concisely and consistently. This study explores the effects of different information visualizations on decision quality in a Web environment by conducting a laboratory experiment. The results demonstrated that the effects of information visualizations on decision quality were significant. The findings suggest that information users in a Web environment can expect to improve their decision quality by enhancing information visualizations. This research extends a body of research examining not only the effects of factors that can be tied to human decision-making, but also the predictions of various information visualization usages in a Web environment.

Quality Control System Based on Cbm in Injection Molding Product (CBM 기반의 사출품 품질 관리 시스템)

  • Park, Hong-Seok;Kim, Jong-Su
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.18 no.2
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    • pp.178-186
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    • 2009
  • Most of automotive plastic parts are injection molding products. Inspection of total product is impossible, because number of product to inspect is too many and various. Condition-based Monitoring was proposed to decrease cost and time for inspecting. In this research, a system that predicts quality of part at fabrication point of time, and confirms informations through the internet was developed. Cavity sensors were installed inside of mold, and gathered signals as measuring, and through this process Sensor-based Monitoring system can be observed manufacturing of a part. Monitoring system transmits signals to client through the internet, and finally developed system provides manufacturing informations and predictions of quality as web-based monitoring.

A Review of Mobile Display Image Quality

  • Kim, Youn Jin
    • Information Display
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    • v.15 no.5
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    • pp.22-32
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    • 2014
  • The current research intends to quantify the surround luminance effects on the shape of spatial luminance CSF and to propose an image quality evaluation method that is adaptive to both surround luminance and spatial frequency of a given stimulus. The proposed image quality method extends to a model called SQRI[8]. The non-linear behaviour of the HVS was taken into account by using CSF. This model can be defined as the square root integration of multiplication between display MTF and CSF. It is assumed that image quality can be determined by considering the MTF of the imaging system and the CSF of human observers. The CSF term in the original SQRI model was replaced by the surround adaptive CSF quantified in this study and it is divided by the Fourier transform of a given stimulus. A few limitations of the current work should be addressed and revised in the future study. First, more accurate model predictions can be achievable when the actual display MTF is measured and used instead of the approximation. Then, a further improvement to the model prediction accuracy can be made when chromatic adaptation of the HVS is taken into account[45-46].

Air Quality Prediction by CDMQC and Its Validation in the Ulsan Industrial Complex (CDMQC Model을 이용(利用)한 울산지역(蔚山地域)의 대기질(大氣質) 예측(豫測)과 실측치(實測値)와의 비교연구(比較研究))

  • Shin, Eung Bai;Lee, Kwang Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.1 no.1
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    • pp.77-90
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    • 1981
  • This study involves 1) air quality disperson predictions and 2) a comparison of the predicted data with the actually measured ones in terms of annual sulfur dioxide concentration in the Ulsan Industial Complex. The prediction was made by utilizing the CDMQC air quality simulation computer model. The higher concentrations were observed at the Bugok Dong (Sampling Site) and the Yeochun Dong Sampling Site with the values of 44 and 46 ppb, respectively whereas the predicted values for both sites were 52 and 47 ppb, respectively. A statistical examination has revealed that the level of confidence was 90.02% from the Chi-squared test and the corelation coefficient was 0.827. It thus demonstrates that the model used for the study appears to be applicable to yield reliable predictions in terms of annual sulfur dioxide concentrations in the study area.

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A Study on Spatial Prediction of Water Quality Constituents Using Spatial Model (공간모형을 이용한 수질오염물질의 공간적 예측 및 평가에 대한 연구)

  • Kang, Taegu;Lee, Hyuk;Kang, Ilseok;Heo, Tae-Young
    • Journal of Korean Society on Water Environment
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    • v.30 no.4
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    • pp.409-417
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    • 2014
  • Spatial prediction methods have been useful to determine the variability of water quality in space and time due to difficulties in collecting spatial data across extensive spaces such as watershed. This study compares two kriging methods in predicting BOD concentration on the unmonitored sites in the Geum River Watershed and to assess its predictive performance by leave-one-out cross validation. This study has shown that cokriging method can make better predictions of BOD concentration than ordinary kriging method across the Geum River Watershed. Challenges for the application of cokriging on the spatial prediction of surface water quality involve the comparison of network-distance-based relationship and euclidean-distance-based relationship for the improvement in the predictive performance.

A Method for Considering Performance Shaping Factors in Quantitative Human Error Analysis (정량적 인적오류 분석에서 수행도형성인자를 고려하기 위한 방법)

  • 정광태
    • Journal of the Korean Society of Safety
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    • v.12 no.1
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    • pp.113-121
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    • 1997
  • Human reliability attempts to make precise quantitative analyses and predictions of the performance of human-machine(or product) systems. In order to yield more precise human error analysis, precise human error probabilities(HEPs) must be used in the analysis. However, because human behavior is influenced by factors that are called performance shaping factors(PSFs), the effects of PSFs must be considered to obtain precise HEPs, These are called basic HEPs or situation-specific HEPs. This paper presents a theoretical method for obtaining basic HEPs (i.e. , considering PSFs) in quantitative human error analysis. In this method, the weight which characterizes the degree of importance of several PSFs is obtained by the analytic hierarchy process. The quality scores of PSFs in the task situation are obtained by percentile concept. These scores are used in conjunction with the relative Importance weights of PSFs to compute the composite quality percentile score of PSFs in the task situation. Then, a new mapping method of the composite quality percentile score of PSFs into a situation-specific basic HEP is proposed with a numerical example.

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The Impact of Ventilation Strategies on Indoor Air Pollution: A Comparative Study of HVAC Systems Using a Numerical Model (실내오염물질의 환기기술전략에 따른 영향평가 : 수치적 모델을 이용한 HVAC 시스템의 비교연구)

  • Park, Sung-Woo;Song, Dong-Woong;D.J. Moschandreas
    • Journal of Korean Society for Atmospheric Environment
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    • v.11 no.E
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    • pp.45-54
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    • 1995
  • Indoor air quality models are useful to predict indoor air pollutant concentrations as a function of several indoor factors. Indoor air quality model was developed to evaluate the pollutant removal efficiency of variable-air-volume/bypass filtration system (VAV/BPFS) compared with the conventional variable-air-volume (VAV) system. This model provides relative pollutant removal effectiveness of VAV/BPFS by concentration ratio between the conventional VAV system and VAV/BPFS. The predictions agree closely, from 5 to 10 percent, with the measured values for each energy load. As a results, we recommend the VAV/BPFS is a promising alternative to conventional VAV system because it is capable of reducing indoor air pollutant concentration and maintaining good indoor air quality.

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