• Title/Summary/Keyword: Numeric model

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A Numeric Modelling Technique for the Shape Development of Fatigue Crack (피로 균열 형상 진전의 수치 모델링 기법에 관한 연구)

  • Han, Moon-Sik
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.2 s.95
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    • pp.225-233
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    • 1999
  • This paper describes a versatile finite element technique which has been used to investigate of wide range of structural defects of practical importance. The procedure automatically remeshes the three-dimensional finite element model during the stages of crack growth. Problems analyzed to date include the surface cracks in leak-before-break situations, the development of quarter-elliptical corner defects, planar semi-elliptical surface defects and the fatigue growth of defects.

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Interpretation of a Model Output : Fuzzy Logic Approach

  • Yang, Kyung Hoon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.3 no.2
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    • pp.36-44
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    • 1993
  • Not all business executives can afford the time or cost of having an expert interpret the output of management science models. They find these models perplexing because they are given in the form of numeric vectors or metrics. In this paper, we discuss the possibility of developing an expert system to assist managers' interpretation of the models' results. Having gained interpreting skills, these executive may integrate the system with commercial software.

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Sales Forecasting Model Considering the Local Environment

  • Kim, Chul Soo;Oh, Su Min;Park, So Yeon
    • Communications for Statistical Applications and Methods
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    • v.19 no.6
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    • pp.849-858
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    • 2012
  • Today, local environmental factors has an influence on our society. Local environmental factors, as well as weather-related natural phenomena, social phenomena are also included. In this paper, numeric factors and categorical factors were analyzed, looking for a local environmental factors affecting the company's sales.Sales model by performing a regression analysis based on this was implemented.Sales model considering the local environment had an accuracy of 88.89%.

A Study on the Linear Compensation Method of Ideal Surface Roughness to Actual Roughness in Milling (밀링에서 기하학적 표면조도와 측정조도의 선형보정 방법에 관한 연구)

  • Seo, Sang-Won;Kim, Dong-Hyeon;Kim, Su-Jin
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.15 no.3
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    • pp.15-20
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    • 2016
  • In this study, a numeric model for the prediction of ideal surface roughness in the rounded end mill was derived from the shape of the tool and feed per tooth. The model is compared with the well-known model of a ball and flat end mill. The ideal surface roughness was matched to the actual surface roughness by the linear equation, from which the empirical constant should be gathered from the test machining systems in the industry.

Certifying the Quality of Electronic Commerce Services (전자상거래 서비스 품질 인증에 관한 연구)

  • Choi, Doug-W.
    • Journal of Korean Society for Quality Management
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    • v.33 no.2
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    • pp.1-12
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    • 2005
  • An extensive literature review has been made in this paper to build the evaluation hierarchy structure for the certification of electronic commerce services. In building the evaluation hierarchy structure, major candidate evaluation factors are selected by bench marking the various certification practices, including the Malcolm Baldrige award, ISO9000, and BSC(balanced scorecard) techniques. This paper deployed principal component analysis and factor analysis techniques to develop a statistically solid and systematic evaluation model. The final evaluation model, as presented in this paper as a model for the certification of electronic commerce services, produces a numeric score on the 100% scale, which can be served as a metric for the certification decision. The AHP technique was used in converting the various qualitative and quantitative evaluation values into a single measure for the certification decision.

A Study on Making Map of Flood Using Digital Elevation Model (DEM) (수치표고모형 (DEM)을 이용한 침수재해 지도작성에 관한 연구)

  • Lim, Hyun Taek;Kim, Jae Hwi;Lee, Hak Beom;Park, Sung Yong;Kim, Yong Seong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.59 no.2
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    • pp.81-90
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    • 2017
  • Recent floodplain data are important for river master plan, storm and flood damage reduction comprehensive plan and pre-disaster impact assessment. Hazard map, base of floodplain data, is being emphasized as important method of non-structural flood prevention and consist of inundation trace map, inundation expected map and hazard information map. Inundation trace map describes distribution of area that damaged from typhoons, heavy rain and tsunamis and includes identified flood level, flood depth and flood time from flooding area. However due to lack of these data by local government, which are foundational and supposed to be well prepared nationwide, having hard time for making inundation trace map or hazard information map. To overcome this problem, time consumption and budget reduction is required through various research. From this study, DEM (Digital Elevation Model) from image material from UAVS (Unmanned Aerial Vehicle System) and numeric geographic map from National Geographic Information Institute are used for calculating flooding damaged area and compared with inundation trace map. As results, inundation trace map DEM based on image material from UAVS had better accuracy than that used DEM based on numeric geographic map. And making hazard map could be easier and more accurate by utilizing image material from UAVS than before.

A Development of 3-D Numeric Model for the Confined Flow and Discharge under Sea Ground (해저 지중 피압유체의 흐름과 양수량 산출에 관한 3차원 수치모형의 개발)

  • Kim, Sang-Jun
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.22 no.6
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    • pp.387-396
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    • 2010
  • A 3-D numeric model for the confined transient flow under sea ground have been developed. This is FDM model using Gauss-Seidel SOR (successive over-relaxation). This model shows the similar head distribution pattern to Theis analytic solution and MODFLOW simulation. The input flowrate to the aquifer and discharge of well have been compared. And it have been found that mass balance is influenced by the weight factor ${\alpha}$, i.e. fullyimplicit method (${\alpha}$=1) shows 5% error, but when ${\alpha}$ becomes to 0.5(Crank and Nicolson method) the mass balance becomes worse and the model result diverges. And the convergency of the model is not much different when $\lambda$ (over-relaxation factor)=0.8~1.5, but when $\lambda$>1.5, the model result diverges. The test-run shows that the well discharge becomes smaller when another well is near. This model can cover the isotropy$(Kx{\neq}Ky{\neq}Kz)$ and inhomogeneity, and can be used for the selection of well site, discharge calculation, and head prediction in case of the artificial recharge etc.

Developing a Quantitative Evaluation Model for Screening the Research Grant Applications (연구지원 대상자 선정을 위한 정량평가 모형개발)

  • Yoo, Jin-Man;Han, In-Soo;Oh, Keun-Yeob
    • The Journal of the Korea Contents Association
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    • v.17 no.4
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    • pp.541-549
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    • 2017
  • This research investigates the quantitative screening methods for the Grant Funding system and seeks for the efficient evaluation of a number of proposals. We search foreign cases of Grand Funding, but we found no appropriate model for using in Korea. Thus, we had to develope our own model for better screening. First, we analyse the existing evaluation system and find some problems and challenges. Second, we suggest a quantitative screening system for Grant Funding with a numeric model, and operates a tedious simulation by using the previous data and our suggested model. Third, we test the suggested model and find the optimal model by using simulation method The number of data analysed for simulation is larger than 200 thousands. Last, we suggest some brief policy implications based on the results in the paper.

Effect of model calibration on seismic behaviour of a historical mosque

  • Demir, Ali;Nohutcu, Halil;Ercan, Emre;Hokelekli, Emin;Altintas, Gokhan
    • Structural Engineering and Mechanics
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    • v.60 no.5
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    • pp.749-760
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    • 2016
  • The objective of the study is to investigate the effects of model calibration on seismic behaviour of a historical mosque which is one of the most significant Ottomon structures. Seismic analyses of calibrated and noncalibrated numeric models were carried out by using acceleration records of Kocaeli earthquake in 1999. In numerical analysis, existing crack zones on real structure was investigated in detail. As a result of analyses, maximum stresses and displacements of calibrated and noncalibrated numerical models were compared each other. Consequently, seismic behaviour and damage state of historical masonry Hafsa Sultan mosque was determined as more realistic in the event of a severe earthquake.

A Study on Automatic Security Diagnostic Evaluation System for Security Assurance (보안 안전성을 위한 자동화 보안진단평가 시스템에 관한 연구)

  • Eom, Jung Ho;Park, Seon Ho;Chung, Tai M.
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.5 no.4
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    • pp.109-116
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    • 2009
  • In the paper, we designed an automatic security diagnostic evaluation System(SeDES) based on a security diagnostic evaluation model(SeDEM) for an organization's security assurance. The SeDEM evaluates a security level of an organization quantitatively by a security evaluation formula which is composed of security variables and security index as applying the statistical CAEL model for evaluate risk level of banks. The SeDES has a good expandability as changing security variables according to an organization scale, characteristics and so on. And it also has a excellent usage because it inputs only numeric data got from statistical technique to security index. We can understand more a security level correctly than the existent risk assessment system because it is possible to assess quantitatively with an security grade as well as score. analysis.