• Proceedings of the KIEE Conference
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.591-593
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• 2005

This paper presents the dynamic analysis of a humanoid robot using Nastran that is one of FEM analysis program. Generally, computer program based on the Lagrange-Euler method or Newton-Euler method was used for dynamic analysis of a robot. The Lagrange-Euler method requires much calculation performance and it is also hard to apply to complex structure, and the Newton-Euler method limits accurate modeling and calculation for closed structure like a humanoid robot. In this paper, mechanical and structural data are obtained from the Nastran. It is possible for Nastran to make model similar to real system and can apply a physical properties and laws to model. So, accurate simulation is possible. From this result, accurate data is gained by Nastran. Furthermore, this method is shown to be a useful method that guarantees accuracy for trajectory planning.

• The Transactions of The Korean Institute of Electrical Engineers
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• 제56권12호
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• pp.2109-2115
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• 2007

The wind generators have been installed with high output power to increase the energy production and efficiency. Hence, Optimal design of the direct-driven PM wind generator, coupled with F.E.M(Finite Element Method) and Genetic Algorithm(GA), has been performed to maximize the Annual Energy Production(AEP) over the whole wind speed characterized by the statistical model of wind speed distribution. Particularly, the parallel computing via internet web service has been applied to loose excessive computing times for optimization. The results of the optimal design of Surface-Mounted Permanent Magnet Synchronous Generator(SPMSG) are compared with each other candidates to verify the usefulness of the maximizing AEP model.

• Proceedings of the KSME Conference
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.351-356
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• 2000

The mechanical stress due to the wheel-rail contact and thermal stress due to the drag braking increase the incidence of wheel failure. So, firstly, stress analyses(mechanical, thermal and combined stress) of wheel plate are performed using 3-dimensional finite element method(FEM). Secondly, the optimum design of wheel plate is investigated in order to reduce weight of the wheel based on results of stress analysis. The optimum design is peformed using 2-dimensional axisymmetric F.E. model and its results are verified by 3-dimensional F. E. model.

• Proceedings of the KIEE Conference
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• 대한전기학회 2002년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.131-134
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• 2002

The optimum design technology using combind F.E.M and eauivalent circuit is so fast and accurate that it can be applied to the optimum rotor design of an inverter-fed induction motor in high efficiency motor making industry. The optimum characteristics fer a rotor slot model of a 3 phase inverter-134 nduction motor was previously verified by a time-step F.E.M. In this paper, four verification models with the design variables near the optimum point are designed to chech whether the characteristics of a slot model presented is not less than those of the near models. The outputs of whole models are analyzed in a time-step Finite Element Method and compared in the experimental test. The economical and efficient selecting method of design variables fur the computer simulation and experimental test is presented in order to assure the optimum point.

• Transactions of the Korean Society of Automotive Engineers
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• 제5권3호
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• pp.147-158
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• 1997

This paper presents the analysis technique and procedure of main engine components-cylinder block, cylinder liners, gasket and cylinder head-using the finite element method, which aims to assess mainly the potential of lower oil consumption in a view point of engine design and to decide subsequently the accuracy of engine design which was done. The F.E. model of an engine section consisting of one whole cylinder and two adjacent half cylinders is used, whereby the crankcase is cut off at the block bottom deck. By means of a 3-dimensional F.E. model-including cylinder block, liners, gasket, cylinder head, bolts and valve seat rings as separate parts a linear analysis of deformations and stresses was performed for three different loading conditions;assembly, thermal and gas loads. For the analysis of thermal boundary conditions also the temperature field had to be evaluated in a subsequent step.

• Korean Journal of Human Ecology
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• 제3권1호
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• pp.1-14
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• 1994

This study is carried out to develope parent education methodology by analysing "${\acute{E}}cole$ des Parents" of France. To study this subject we approach by following three methodes. Firstly, we examined bibliographes to find out motivation of initiative caused from hystological and sociological circumstance. Secondly, to analyse chronological developement and modification of "${\acute{E}}cole$ des Parents" we interviewed with three periods of persons : founder, developer and actually working animators. In addition, we riviewed three hundred eighty volumes of $\underline{{\acute{E}}cole\;des\;Parents}$, from first jurnals to october, 1993. Thirdly, this study were approached by participant observation in actual activities, and by analyse statstical records and subject of articals. In results, we noticed following caractors working in french parent education system. All the regional "${\acute{E}}cole$ des Parents" are alined with "$F{\acute{E}}d{\acute{E}}ration$ Nationale des ${\acute{E}}cole$ des Parents et des ${\acute{E}}ducateurs$"(F.N.E.PE.) in educational polish but activities and methodes of education are independant with F.N.E.P.E., and in most different regional "${\acute{E}}cole$ des Parents" focussed the educational programes to the middle class families in economic point of view. these programes adjust very rapidly systematicaly to social requirment due to successed intensive research. Mordern programs tend to contain all members of family in stead of targeting only maternal members. Methodes of education by lectures and speechs only to deliver information also replaced by discussion, forum and groop animation to induce self-correction. We propose that the systems of FNEPE can be ideal models to solve many actual problems facing in Korean parent education systemes.

• Journal of Korean Institute of Industrial Engineers
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• 제5권2호
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• pp.21-36
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• 1979

Static muscle contractions when prolonged or frequently repeated result in discomfort, fatigue, and musculosketal injuries. An analytic and quantitative model has been developed in order to expand the working knowledge on muscle fatigue. In this paper, three Markov models of muscle fatigue are developed. These models are based on motor unit fatigue-recovery characteristics obtained from information on motor unit behavior as it relates to fatigue and graded exertions. Three successively more realistic models are developed that involve: (1) homogeneous motor units with intensity-dependent fatigue rates and state-independent recovery rates (the HMSI model); (2) homogeneous motor units, intensity-dependent fatigue rates and state-dependent recovery rates (the HMSD model); and (3) non-homogeneous motor units (i.e., Type S and Type F), intensity-dependent fatigue rates and state-dependent recovery rates (the HMSD model). The result indicate that a simple stochastic model provide a means to analyze the complex nature of muscle fatigue in sequential static exertions.

• Proceedings of the Korean Society of Crop Science Conference
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.141-141
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• 2017

The ubiquitin-proteasome pathway is the major regulatory mechanism in a number of cellular processes for selective degradation of proteins and involves three steps: (1) ATP dependent activation of ubiquitin by E1 enzyme, (2) transfer of activated ubiquitin to E2 and (3) transfer of ubiquitin to the protein to be degraded by E3 complex. F-box proteins are subunit of SCF complex and involved in specificity for a target substrate to be degraded. F-box proteins regulate many important biological processes such as embryogenesis, floral development, plant growth and development, biotic and abiotic stress, hormonal responses and senescence. However, little is known about the F-box genes in wheat. The draft genome sequence of wheat (IWGSC Reference Sequence v1.0 assembly) used to analysis a genome-wide survey of the F-box gene family in wheat. The Hidden Markov Model (HMM) profiles of F-box (PF00646), F-box-like (PF12937), F-box-like 2 (PF13013), FBA (PF04300), FBA_1 (PF07734), FBA_2 (PF07735), FBA_3 (PF08268) and FBD (PF08387) domains were downloaded from Pfam database were searched against IWGSC Reference Sequence v1.0 assembly. RNA-seq paired-end libraries from different stages of wheat, such as stages of seedling, tillering, booting, day after flowering (DAF) 1, DAF 10, DAF 20, and DAF 30 were conducted and sequenced by Illumina HiSeq2000 for expression analysis of F-box protein genes. Basic analysis including Hisat, HTseq, DEseq, gene ontology analysis and KEGG mapping were conducted for differentially expressed gene analysis and their annotation mappings of DEGs from various stages. About 950 F-box domain proteins identified by Pfam were mapped to wheat reference genome sequence by blastX (e-value < 0.05). Among them, more than 140 putative F-box protein genes were selected by fold changes cut-offs of > 2, significance p-value < 0.01, and FDR<0.01. Expression profiling of selected F-box protein genes were shown by heatmap analysis, and average linkage and squared Euclidean distance of putative 144 F-box protein genes by expression patterns were calculated for clustering analysis. This work may provide valuable and basic information for further investigation of protein degradation mechanism by ubiquitin proteasome system using F-box proteins during wheat development stages.

• Korean Chemical Engineering Research
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• 제62권3호
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• pp.214-224
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• 2024

Valves play an essential role in a chemical plant such as regulating fluid flow and pressure. Therefore, optimal selection of the valve size and type is essential task. Valve size and type have been selected based on theoretical formulas about calculating valve sizing coefficient (Cv). However, this approach has limitations such as requiring expert knowledge and consuming substantial time and costs. Herein, this study developed a model for predicting valve sizes and types using machine learning. We developed models using four algorithms: ANN, Random Forest, XGBoost, and Catboost and model performances were evaluated using NRMSE & R² score for size prediction and F1 score for type prediction. Additionally, a case study was conducted to explore the impact of phases on valve selection, using four datasets: total fluids, liquids, gases, and steam. As a result of the study, for valve size prediction, total fluid, liquid, and gas dataset demonstrated the best performance with Catboost (Based on R², total: 0.99216, liquid: 0.98602, gas: 0.99300. Based on NRMSE, total: 0.04072, liquid: 0.04886, gas: 0.03619) and steam dataset showed the best performance with RandomForest (R²: 0.99028, NRMSE: 0.03493). For valve type prediction, Catboost outperformed all datasets with the highest F1 scores (total: 0.95766, liquids: 0.96264, gases: 0.95770, steam: 1.0000). In Engineering Procurement Construction industry, the proposed fluid-specific machine learning-based model is expected to guide the selection of suitable valves based on given process conditions and facilitate faster decision-making.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 한국경영과학회 1988년도 추계학술발표회 발표논문초록집; 서울시립대학교 사회과학관, 서울; 5 Nov. 1988
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• pp.9-9
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• 1988