• Title/Summary/Keyword: Comparative modeling

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The Comparative Analysis of Agricultural Pipe House by 2 and 3-Dimensional Modeling (농업용 파이프 하우스의 2차원 및 3차원 구조해석 비교분석)

  • Choi, Won;Yoon, Seong-Soo;Lee, Jeong-Jae
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2001.10a
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    • pp.207-211
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    • 2001
  • The scope has been small and the specification has been not suggested yet when the pipe house was planed by farmer in Korea. The construction has been made by the suitable agreement of builder and farmer. Also, life cycle time of the pipe house material under serviceability load is not suggested yet. This study is to consider problems of past 2-dimension modeling, to introduce new 3-dimension modeling about pipe house analysis and to know that how the structure under various loads conditions behaves. Therefore, the object is to discuss the current design and to suggest new analysis modeling of the pipe house.

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A Study on Diagnostics of Machining System with ARMA Modeling and Spectrum Analysis (ARMA 모델링과 스펙트럼분석법에 의한 가공시스템의 진단에 관한 연구)

  • 윤문철;조현덕;김성근
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.8 no.3
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    • pp.42-51
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    • 1999
  • An experimental modeling of cutting and structural dynamics and the on-line detection of malfunction process is substantial not only for the investigation of the static and dynamic characteristics of cutting process but also for the analytic realization of diagnostic systems. In this regard, We have discussed on the comparative assessment of two recursive time series modeling algorithms that can represent the machining process and detect the abnormal machining behaviors in precision round shape machining such as turning, drilling and boring in mold and die making. In this study, simulation and experimental work were performed to show the malfunctioned behaviors. For this purpose, two new recursive approach (REIVM, RLSM) were adopted fur the on-line system identification and monitoring of a machining process, we can apply these new algorithm in real process for the detection of abnormal machining behaviors such as chipping, chatter, wear and round shape lobe waviness.

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Comparative Analysis of SOC Estimation using EECM and NST in Rechargeable LiCoO2/LiFePO4/LiNiMnCoO2 Cells

  • Lee, Hyun-jun;Park, Joung-hu;Kim, Jonghoon
    • Journal of Electrical Engineering and Technology
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    • v.11 no.6
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    • pp.1664-1673
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    • 2016
  • Lithium rechargeable cells are used in many industrial applications, because they have high energy density and high power density. For an effective use of these lithium cells, it is essential to build a reliable battery management system (BMS). Therefore, the state of charge (SOC) estimation is one of the most important techniques used in the BMS. An appropriate modeling of the battery characteristics and an accurate algorithm to correct the modeling errors in accordance with the simplified model are required for practical SOC estimation. In order to implement these issues, this approach presents the comparative analysis of the SOC estimation performance using equivalent electrical circuit modeling (EECM) and noise suppression technique (NST) in three representative $LiCoO_2/LiFePO_4/LiNiMnCoO_2$ cells extensively applied in electric vehicles (EVs), hybrid electric vehicles (HEVs) and energy storage system (ESS) applications. Depending on the difference between some EECMs according to the number of RC-ladders and NST, the SOC estimation performances based on the extended Kalman filter (EKF) algorithm are compared. Additionally, in order to increase the accuracy of the EECM of the $LiFePO_4$ cell, a minor loop trajectory for proper OCV parameterization is applied to the SOC estimation for the comparison of the performances among the compared to SOC estimation performance.

A Comparative Study of Ice Scour-Seabed Interaction Models (빙쇄굴-해저지반 상호작용 모델 비교연구)

  • 최경식;이종호
    • Journal of Ocean Engineering and Technology
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    • v.16 no.1
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    • pp.27-35
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    • 2002
  • The interaction of grounded ice ridges with underlying seabed is one of the major considerations in the design of Arctic pipeline system. Previously several ice scour models were developed by researchers to describe the ice scour-seabed interaction mechanism. In view of possible improvements, a comparative study of those ice scour models is performed and their limitation in modeling is discussed. Simple laboratory tests are carried out and then the shape pattern of deposited soil around the ice model is newly defined. Unlike the rectangular idealization of an ice block, in this modified ice scour model, trapezoidal cross sections are assumed to represent the typical shape of an ice ridge based on the field observation data. With the horizontal and vertical motion of ice model, the ice scour depth and soil reacting forces on seabed are calculated with varying the keel angle of an ice ridge.

A Comparative Study of Building Energy Simulations for Building Types in Multiple Stock Housing based on BIM(Building Information Modeling) (BIM기반의 공동주택 주동 유형별 건물에너지 시뮬레이션 비교에 관한 연구)

  • Lee, Byeongho;Lee, Geonwon;Yeo, Youngho
    • KIEAE Journal
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    • v.10 no.4
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    • pp.87-100
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    • 2010
  • The energy efficient design of the multiple stock housing is very important not only to save energy but also to increase sustainability in a whole city because the multiple stock housing type is dominated in the major residential supply markets in Korea. During the early design phase of the multiple stock housing type, the architect need convenient and accurate tools for evaluating energy consumptions based on building types rapidly. Building Information Modeling(BIM) is introduced as useful tool systems providing interoperability between 3rd dimensional modeling tools and environmental engineering analysis tools, and could reduce time and cost for unnecessary modeling works in the analysis. However, it is still hard to apply to building design practice and integrated energy simulation techniques because interoperability using industrial standard file formats such as IFC and bXML is still underdeveloped. Therefore, the purpose of this study is to perform the building energy simulations, to compare the results on typical building types in multiple stock housing based on BIM, and to clear the problems using industrial standard file formats between 3rd dimensional modeling and building energy simulation software. In addition, through comparisons with simulation results according to the typical building types such as building forms, orientations, and building stories, the interrelation ship and characteristics of BIM based building energy simulation software are analysed and evaluated.

Performance Analysis of Electricity Demand Forecasting by Detail Level of Building Energy Models Based on the Measured Submetering Electricity Data (서브미터링 전력데이터 기반 건물에너지모델의 입력수준별 전력수요 예측 성능분석)

  • Shin, Sang-Yong;Seo, Dong-Hyun
    • Journal of Korean Institute of Architectural Sustainable Environment and Building Systems
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    • v.12 no.6
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    • pp.627-640
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    • 2018
  • Submetering electricity consumption data enables more detail input of end use components, such as lighting, plug, HVAC, and occupancy in building energy modeling. However, such an modeling efforts and results are rarely tried and published in terms of the estimation accuracy of electricity demand. In this research, actual submetering data obtained from a university building is analyzed and provided for building energy modeling practice. As alternative modeling cases, conventional modeling method (Case-1), using reference schedule per building usage, and main metering data based modeling method (Case-2) are established. Detail efforts are added to derive prototypical schedules from the metered data by introducing variability index. The simulation results revealed that Case-1 showed the largest error as we can expect. And Case-2 showed comparative error relative to Case-3 in terms of total electricity estimation. But Case-2 showed about two times larger error in CV (RMSE) in lighting energy demand due to lack of End Use consumption information.

Comparative modeling of human tyrosinase - An important target for developing skin whitening agents (사람 티로시나제의 3차원 구조 상동 모델링)

  • Choi, Jong-Keun;Suh, Joo-Won
    • Proceedings of the KAIS Fall Conference
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    • 2012.05a
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    • pp.182-186
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    • 2012
  • human tyrosinase (hTyr) catalyzes first and the rate limiting step in the synthesis of polymerized pigment, melanin which determines skin, hair and eye colors. Mutation of hTyr often brings about decrease of melanin production and further albinism. Meanwhile, a number of cosmetic companies providing skincare products for woman in Asia-Pacific region have tried to develop inhibitors to bright skin color for several decades. In this study, we built a 3D structure by comparative modeling technique based on the crystal structure of tyrosinase from bacillus megaterium as a template to serve structural information of hTyr. According to our model and sequence analysis of type 3 copper protein family proteins, two copper atoms of active site located deep inside are coordinated with six strictly conserved histidine residues coming from four-helix-bundle. Cavity which accommodates substrates was like funnel shape of which entrance was wide and expose to solvent. In addition, protein-substrate and protein-inhibitor complex were modeled with the guide of van der waals surface generated by in house software. Our model suggested that only phenol group or its analogs can fill the binding site near nuclear copper center because inside of binding site has narrow shape relatively. In conclusion, the results of this study may provide helpful information for designing and screening new anti-melanogensis agents.

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Air Quality Modeling of Ozone Concentration According to the Roughness Length on the Complex Terrain (복잡지형에서의 지표면 거칠기에 따른 오존 농도 수치모의)

  • Choi, Hyun-Jung;Lee, Hwa-Woon;Sung, Kyoung-Hee
    • Journal of Korean Society for Atmospheric Environment
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    • v.23 no.4
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    • pp.430-439
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    • 2007
  • The objective of this work is the air quality modeling according to the practical roughness length using the building information as surface boundary conditions. As accurate wind and temperature field are required to produce realistic urban air quality modeling, comparative simulations by various roughness length are discussed. The prognostic meteorological fields and air quality field over complex areas of Seoul, Korea are generated by the PSU/NCAR mesoscale model (MM5) and the Third Generation Community Multi-scale Air Quality Modeling System (Models-3/CMAQ), respectively. The simulated $O_3$ concentration on complex terrain and their interactions with the weak synoptic flow had relatively strong effects by the roughness length. A comparison of the three meteorological fields of respective roughness length reveals substantial localized differences in surface temperature and wind folds. Under these conditions, the ascended mixing height and weakened wind speed at night which induced the stable boundary stronger, and the difference of simulated $O_3$ concentration is $2{\sim}6\;ppb$.

Comparative Study on Surrogate Modeling Methods for Rapid Electromagnetic Forming Analysis

  • Lee, Seungmin;Kang, Beom-Soo;Lee, Kyunghoon
    • Transactions of Materials Processing
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    • v.27 no.1
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    • pp.28-36
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    • 2018
  • Electromagnetic forming is a type of high-speed forming process to deform a workpiece through a Lorentz force. As the high strain rate in an electromagnetic-forming simulation causes infeasibility in determining constitutive parameters, we employed inverse parameter estimation in the previous study. However, the inverse parameter estimation process required us to spend considerable time, which leads to an increase in computational cost. To overcome the computational obstacle, in this research, we applied two types of surrogate modeling methods and compared them to each other to evaluate which model is best for the electromagnetic-forming simulation. We exploited an artificial neural network and we reduced-order modeling methods. During the construction of a reduced-order model, we extracted orthogonal bases with proper orthogonal decomposition and predicted basis coefficients by utilizing an artificial neural network. After the construction of the surrogate models, we verified the artificial neural network and reduced-order models through training and testing samples. As a result, we determined the artificial neural network model is slightly more accurate than the reduced-order model. However, the construction of the artificial neural network model requires a considerably larger amount of time than that of the reduced-order model. Thus, a reduced order modeling method is more efficient than an artificial neural network for estimating the electromagnetic forming and for the rapid approximation of structural simulations which needs repetitive runs.