• Title/Summary/Keyword: ideal model

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Thermal Performance Analysis of Reciprocating Compressors for Refrigerator-freezers (냉장고용 왕복동 압축기의 성능 해석)

  • KIM, MAN-HOE
    • Transactions of the Korean hydrogen and new energy society
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    • v.27 no.2
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    • pp.236-243
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    • 2016
  • This paper presents a simple thermo-physical model of reciprocating compressors for household refrigerator-freezers. The compressor model has been developed based on thermodynamic principles and large data sets from the compressor calorimeter tests. The input data are compressor geometry (displacement and clearance volume), compressor speed, suction pressure and temperature, discharge pressure, and ambient temperature. The model can estimate mass flow rate and compressor power consumption within 3.0% accuracy, which is not much larger than measurement errors associated with calorimeter testing under ideal conditions.

SVM Load Forecasting using Cross-Validation (교차검증을 이용한 SVM 전력수요예측)

  • Jo, Nam-Hoon
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.55 no.11
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    • pp.485-491
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    • 2006
  • In this paper, we study the problem of model selection for Support Vector Machine(SVM) predictor for short-term load forecasting. The model selection amounts to tuning SVM parameters, such as the cost coefficient C and kernel parameters and so on, in order to maximize the prediction performance of SVM. We propose that Cross-Validation method can be used as a model selection algorithm for SVM-based load forecasting technique. Through the various experiments on several data sets, we found that the difference between the prediction error of SVM using Cross-Validation and that of ideal SVM is less than 5%. This shows that SVM parameters for load forecasting can be efficiently tuned by using Cross-Validation.

Walking robot Optimum Design by Jansen's mechanism (Jansen's Mechanism 기반의 보행로봇 최적설계)

  • Kim, Taehyun;Seo, Hankook;Lee, Seohyun
    • Proceeding of EDISON Challenge
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    • 2016.03a
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    • pp.443-454
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    • 2016
  • This study focus to make 8 legs robot based on Jansen's mechanism. In the process of making, we found GL(Ground length),GAC(Ground Angle Coefficient) and the height difference of tract and compare Several models with M.Sketch to find link's Length ratio Optimised simple walking and crossing of obstacles. In the process, our team Analyzed the difference ideal tract (Jansen holy number model's track) contrived by Jansen and our final model tract. As a result, we found optimal link's length ratio to over the obstacles and some features that our model differ from Jansen holy number model. It means that optimal link's length ratio depends on certain circumstances, perfect length ratio is nonexistent.

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Development of TVD Numerical Models: II. Shallow-Water Equations (TVD 수치모형의 개발: II. 천수방정식)

  • Lee, Jong-Uk;Jo, Yong-Sik
    • Journal of Korea Water Resources Association
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    • v.34 no.2
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    • pp.187-195
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    • 2001
  • In this study, a numerical model describing the shallow-water equations is newly developed by using a TVD scheme. The model has a second-order accuracy in time and space and is free from nonphysical oscillations, even in the vicinity of large gradients. Because a upwind based TVD scheme requires a Riemann solver, the HLLC scheme is employed in this model. To calibrate the applicability and accuracy, the developed model is used to simulate dam-break waves in an ideal channel and a sloshing flow n a paraboloidal basin. Agreements between numerical predictions and analytical solutions are very resonable.

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Nonlinear Magnetic Modeling of EI Core Inductor by PLECS Simulation

  • Wang, Zhuning;Sul, Seung-Ki
    • Proceedings of the KIPE Conference
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    • 2015.11a
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    • pp.9-10
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    • 2015
  • EI core inductor in power electronic circuit simulation is usually assumed as linear by using matrix model. However, nonlinear magnetic characteristics such as B-H characteristic are also important for the accurate simulation of the circuit behavior. To model nonlinear magnetic characteristics of EI core inductor with only DC bias table, this paper presents a method in PLECS simulation tool which is a commercially available simulation tool for power electronics circuit analysis. Comparing with ideal matrix model, the simplification and accuracy are improved by this modeling method. Also, compared to analysis by FEM, it is much simpler, faster and easier to simulate with power electronics circuit. Validation of the proposed model was verified by simulation and experiment results.

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A FUNDAMENTAL STUDY ON IMPROVING PROCESS BY APPLYING CONSTRUCTION MANAGEMENT(CM) METHODS TO HOUSING RECONSTRUCTION PROJECTS

  • Kyunghwan Ahn;Keunwon Lee;Myungun Kim;Byungjoo Kang;Won Kwon;Jaeyoul Chun
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.1497-1502
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    • 2009
  • Due to the construction union's inefficient manner of carrying out their construction projects, lot's of conflicts and arguments among the union members are happening, so the proper model of reconstruction and process at each level of projects are also being recognized as an important part of the industry. So I would like to present an ideal process model of home reconstruction industry. Here below I'm presenting the benefits of this model when its applied properly. Through the study of information gained from the survey of residents, benefits such as AHP, analysis of SPSS, reduced construction time, budget cut, etc. will be produced

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Development of the Multi-Path Finding Model Using Kalman Filter and Space Syntax based on GIS (Kalman Filter와 Space Syntax를 이용한 GIS 기반 다중경로제공 시스템 개발)

  • Ryu, Seung-Kyu;Lee, Seung-Jae;Ahn, Woo-Young
    • Journal of Korean Society of Transportation
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    • v.23 no.7 s.85
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    • pp.149-158
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    • 2005
  • The object of this paper is to develop the shortest path algorithm. The existing shortest path algorithm models are developed while considering travel time and travel distance. A few problems occur in these shortest path algorithm models, which have paid no regard to cognition of users, such as when user who doesn't have complete information about the trip meets a strange road or when the route searched from the shortest path algorithm model is not commonly used by users in real network. This paper develops a shortest path algorithm model to provide ideal route that many people actually prefer. In order to provide the ideal shortest path with the consideration of travel time, travel distance and road cognition, travel time is predicted by using Kalman filtering and travel distance is predicted by using GIS attributions. The road cognition is considered by using space data of GIS. Optimal routes provided from this paper are shortest distance path, shortest time path, shortest path considering distance and cognition and shortest path considering time and cognition.

Rehabilitation of a distressed steel roof truss - A study

  • Dar, M.A.;Subramanian, N.;Dar, A.R.;Raju, J.
    • Structural Engineering and Mechanics
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    • v.62 no.5
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    • pp.567-576
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    • 2017
  • Structural failures are undesirable events that devastate the construction industry resulting in loss of life, injury, huge property loss, and also affect the economy of the region. Roof truss failures occur mainly due to excessive loading, improper fabrication, deterioration, inadequate repair, etc. Although very rare, a roof truss may even fail due to inappropriate location of supports. One such case was reported from the recent failure of a steel roof truss used in an indoor stadium at Kargil in India. Kargil region, being mountainous in nature, receives heavy snowfall and hence the steel roof trusses are designed for heavy snow loads. Due to inappropriate support location, the indoor stadium's steel roof truss had failed under heavy snow load for which it was designed and became an interesting structural engineering problem. The failure observed was primarily in terms of yielding of the bottom chord under the supports, leading to partial collapse of the roof truss. This paper summarizes the results of laboratory tests and analytical studies that focused on the validation of the proposed remedial measure for rehabilitating this distressed steel roof truss. The study presents the evaluation of (i) significant reduction in strength and stiffness of the distressed truss resulting in its failure, (ii) desired recovery in both strength and stiffness of the rectified truss contributed by the proposed remedial measure. Three types of models i.e., ideal truss model, as build truss model and rectified truss model were fabricated and tested under monotonic loading. The structural configuration and support condition varied in all the three models to represent the ideal truss, distressed truss and the rectified truss. To verify the accuracy of the experimental results, an analytical study was carried out and the results of this analytical study are compared with the experimental ones.

Caenorhabditis elegans: A Model System for Anti-Cancer Drug Discovery and Therapeutic Target Identification

  • Kobet, Robert A.;Pan, Xiaoping;Zhang, Baohong;Pak, Stephen C.;Asch, Adam S.;Lee, Myon-Hee
    • Biomolecules & Therapeutics
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    • v.22 no.5
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    • pp.371-383
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    • 2014
  • The nematode Caenorhabditis elegans (C. elegans) offers a unique opportunity for biological and basic medical researches due to its genetic tractability and well-defined developmental lineage. It also provides an exceptional model for genetic, molecular, and cellular analysis of human disease-related genes. Recently, C. elegans has been used as an ideal model for the identification and functional analysis of drugs (or small-molecules) in vivo. In this review, we describe conserved oncogenic signaling pathways (Wnt, Notch, and Ras) and their potential roles in the development of cancer stem cells. During C. elegans germline development, these signaling pathways regulate multiple cellular processes such as germline stem cell niche specification, germline stem cell maintenance, and germ cell fate specification. Therefore, the aberrant regulations of these signaling pathways can cause either loss of germline stem cells or overproliferation of a specific cell type, resulting in sterility. This sterility phenotype allows us to identify drugs that can modulate the oncogenic signaling pathways directly or indirectly through a high-throughput screening. Current in vivo or in vitro screening methods are largely focused on the specific core signaling components. However, this phenotype-based screening will identify drugs that possibly target upstream or downstream of core signaling pathways as well as exclude toxic effects. Although phenotype-based drug screening is ideal, the identification of drug targets is a major challenge. We here introduce a new technique, called Drug Affinity Responsive Target Stability (DARTS). This innovative method is able to identify the target of the identified drug. Importantly, signaling pathways and their regulators in C. elegans are highly conserved in most vertebrates, including humans. Therefore, C. elegans will provide a great opportunity to identify therapeutic drugs and their targets, as well as to understand mechanisms underlying the formation of cancer.

Comparative Study on the Mixed Micellizations of Anionic Surfactant (DBS) with Nonionic Surfactnats (Brij 30 and Brij 35) (음이온성 계면활성제(DBS)와 비이온성 계면활성제(Brij 30과 Brij 35)와의 혼합미셀화에 대한 비교연구)

  • Park, In-Jung;Lee, Byung-Hwan
    • Journal of the Korean Chemical Society
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    • v.53 no.5
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    • pp.491-498
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    • 2009
  • The critical micelle concentration (CMC) and the counter ion binding constant (B) for the mixed micellizations of DBS (sodium dodecylbenzenesulfonate) with Brij 30 (polyoxyethylene(4) lauryl ether) and Brij 35 (polyoxyethylene (23) lauryl ehter) at 25 ${^{\circ}C}$ in pure water and in aqueous solutions of n-butanol were determined as a function of $\alpha$1 (the overall mole fraction of DBS) by the use of electric conductivity method. Various thermodynamic parameters (Xi, $\gamma$i, Ci, aiM, $\beta$, and ${\Delta}H_{mix}$) were calculated and compared for each mixed surfactant system by means of the equations derived from the nonideal mixed micellar model. There sults show that the molecules of DBS interact more strongly with Brij 35 than Brij 30 and that the DBS/Brij35 mixed system has greater negative deviation from the ideal mixed micellar model than the DBS/Brij 30mixed system.