• Title/Summary/Keyword: FMI

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The novel expression method of pediatric body composition : fat mass index and fat-free mass index (소아 체성분의 새로운 표현법: 체지방량지수(fat mass index)와 제지방량지수(fat-free mass index))

  • Cho, Young Gyu;Kang, Jae Heon;Song, Hye Ryoung;Kim, Kyung A;Song, Ji Hyun;Jung, Myeong Ho
    • Clinical and Experimental Pediatrics
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    • v.50 no.7
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    • pp.629-635
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    • 2007
  • Purpose : This study was conducted to assess the usefulness of fat-free mass index (FFMI) and fat mass index (FMI) as novel expression methods of body composition in children. Methods : A total of 466 Second grade students-248 boys and 218 girls- from all elementary schools the Gwacheon City underwent anthropometric measures including bioelectrical impedance analysis (BIA) and biochemical tests. The correlation coefficients between obesity indices, including FMI and FFMI, and metabolic risk factors, were assessed. Metabolic risk factors of children with increased FMI were compared with those of children with normal FMI. We compared FMI and FFMI percentile distribution between this study's subjects and the subjects of the Fukuoka body composition study. Results : FMI was lower and FFMI was higher in this study's subjects compared to the subjects of the Fukuoka body composition study. FMI was correlated with other obesity indices and several metabolic risk factors. Metabolic risk was higher in children with increased FMI than in children with normal FMI. Conclusion : FMI and FFMI were useful indicators in comparing difference of body composition among children that had different body size and growth. High FMI was related to increase of metabolic risk in children.

Articulated Rotor/Aerodynamics Co-Simulation Using FMI Standard (FMI 표준을 활용한 관절형 로터/공력 연계시뮬레이션)

  • Paek, Seung-Kil;Park, Joongyong
    • Journal of Aerospace System Engineering
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    • v.9 no.4
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    • pp.1-7
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    • 2015
  • The purpose of this research is to develop co-simulation methodology of codes developed in different modeling and simulation environment. We develop aerodynamic FMU(Functional Mock-up Unit) meeting FMI(Functional Mock-up Interface) specification version2 utilizing Legacy FORTRAN aerodynamic code based on unsteady vortex lattice method. It is concluded that making FMU is possible utilizing Legacy code made in any language which can be compiled and linked with object in FMI API coded in C language. This paper explains QTronic's method of using FMU SDK(Software Development Kit) and suggestion for using FORTRAN properly. Finally, we make articulated rotor/aerodynamics co-simulation by integrating aerodynamics FMU and rotor FMU developed by Modelica.

An FMI-based Time Management Scheme for Real-time Co-Simulation (실시간 Co-Simulation을 위한 FMI 기반 시간관리 기법)

  • Kyung, Dong-Gu;Joe, Inwhee;Kim, Wontae
    • Journal of IKEEE
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    • v.24 no.2
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    • pp.426-434
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    • 2020
  • FMI is being researched as a standard for linking large-scale simulation of CPS. In order to guarantee the reliability of the results in large-scale simulations using FMI, event handling through time management techniques is required. This paper aims to guarantee real-time performance and accuracy in large-scale co-simulation environments such as CPS. Synchronize the wallclock time and simulation time to ensure real time. Also, to ensure the accuracy, before the simulation, the event is checked and the simulation is performed with the smallest step size while maintaining the real time until the event occurrence time. As a result, the events occurring in the co-simulation environment are processed immediately and sequentially, ensuring the real-time performance and minimizing the numerical integration error by maximizing the simulation resolution. In the experiment, the proposed method was processed immediately, and it was confirmed that the numerical integration error is reduced by about 1/5 unlike the existing time management method which does not guarantee the resolution.

FMI based Real-time CPS Distributed Simulation Framework using OMG DDS middleware (OMG DDS 미들웨어를 이용한 FMI기반 실시간 CPS 분산 시뮬레이션 프레임워크)

  • Hong, Seokjoon;Joe, Inwhee;Kim, Wontae
    • Journal of IKEEE
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    • v.22 no.1
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    • pp.6-13
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    • 2018
  • To develop highly dependable CPS, M&S(modeling and simulation) is very important. It is not easy to model any CPS whole system in a single simulation tool because each simulation tool is optimized for modeling each different part of the CPS. The FMI is the standard for M&S between different simulation tools. The DDS is a communication middleware suitable for large-scale real-time data transmission. In this paper, we proposed FMI based CPS real-time distributed simulaton framework using DDS. To evaluate the performance of the proposed framework, we performed distributed simulation using IEEE HLA/RTI and OMG DDS middleware and measured and compared the execution time of the entire simulation. From the simulation results, we can confirm that the simulation execution time using DDS is at least 1.14 times faster compared to execution time using HLA/RTI.

A Prediction Method using Markov chain for Step Size Control in FMI based Co-simulation (FMI기반 co-simulation에서 step size control을 위한 Markov chain을 사용한 예측 방법)

  • Hong, Seokjoon;Lim, Ducsun;Kim, Wontae;Joe, Inwhee
    • Journal of IKEEE
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    • v.23 no.4
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    • pp.1430-1439
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    • 2019
  • In Functional Mockup Interface(FMI)-based co-simulation, a bisectional algorithm can be used to find the zerocrossing point as a way to improve the accuracy of the simulation results. In this paper, the proposed master algorithm(MA) analyzes the repeated interval graph and predicts the next interval by applying the Markov Chain to the step size. In the simulation, we propose an algorithm to minimize the rollback by storing the step size that changes according to the graph type as an array and applying it to the next prediction interval when the rollback occurs in the simulation. Simulation results show that the proposed algorithm reduces the simulation time by more than 20% compared to the existing algorithm.

SCANNING ELECTRON MICROSCOPY ANALYSIS OF FUEL/MATRIX INTERACTION LAYERS IN HIGHLY-IRRADIATED U-Mo DISPERSION FUEL PLATES WITH Al AND Al-Si ALLOY MATRICES

  • Keiser, Dennis D. Jr.;Jue, Jan-Fong;Miller, Brandon D.;Gan, Jian;Robinson, Adam B.;Medvedev, Pavel;Madden, James;Wachs, Dan;Meyer, Mitch
    • Nuclear Engineering and Technology
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    • v.46 no.2
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    • pp.147-158
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    • 2014
  • In order to investigate how the microstructure of fuel/matrix-interaction (FMI) layers change during irradiation, different U-7Mo dispersion fuel plates have been irradiated to high fission density and then characterized using scanning electron microscopy (SEM). Specifially, samples from irradiated U-7Mo dispersion fuel elements with pure Al, Al-2Si and AA4043 (~4.5 wt.%Si) matrices were SEM characterized using polished samples and samples that were prepared with a focused ion beam (FIB). Features not observable for the polished samples could be captured in SEM images taken of the FIB samples. For the Al matrix sample, a relatively large FMI layer develops, with enrichment of Xe at the FMI layer/Al matrix interface and evidence of debonding. Overall, a significant penetration of Si from the FMI layer into the U-7Mo fuel was observed for samples with Si in the Al matrix, which resulted in a change of the size (larger) and shape (round) of the fission gas bubbles. Additionally, solid fission product phases were observed to nucleate and grow within these bubbles. These changes in the localized regions of the microstructure of the U-7Mo may contribute to changes observed in the macroscopic swelling of fuel plates with Al-Si matrices.

Serial Observations of Muscle and Fat Mass as Prognostic Factors for Deceased Donor Liver Transplantation

  • Jisun Lee;Woo Kyoung Jeong;Jae-Hun Kim;Jong Man Kim;Tae Yeob Kim;Gyu Seong Choi;Choon Hyuck David Kwon;Jae-Won Joh;Sang-Yong Eom
    • Korean Journal of Radiology
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    • v.22 no.2
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    • pp.189-197
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    • 2021
  • Objective: Muscle depletion in patients undergoing liver transplantation affects the recipients' prognosis and therefore cannot be overlooked. We aimed to evaluate whether changes in muscle and fat mass during the preoperative period are associated with prognosis after deceased donor liver transplantation (DDLT). Materials and Methods: This study included 72 patients who underwent DDLT and serial computed tomography (CT) scans. Skeletal muscle index (SMI) and fat mass index (FMI) were calculated using the muscle and fat area in CT performed 1 year prior to surgery (1 yr Pre-LT), just before surgery (Pre-LT), and after transplantation (Post-LT). Simple aspects of serial changes in muscle and fat mass were analyzed during three measurement time points. The rate of preoperative changes in body composition parameters were calculated (preoperative ΔSMI [%] = [SMI at Pre-LT - SMI at 1 yr Pre-LT] / SMI at Pre-LT x 100; preoperative ΔFMI [%] = [FMI at Pre-LT - FMI at 1 yr Pre-LT] / FMI at Pre-LT x 100) and assessed for correlation with patient survival. Results: SMI significantly decreased during the preoperative period (mean preoperative ΔSMI, -13.04%, p < 0.001). In the multivariable analysis, preoperative ΔSMI (p = 0.016) and model for end-stage liver disease score (p = 0.011) were independent prognostic factors for overall survival. The mean survival time for patients with a threshold decrease in the preoperative ΔSMI (≤ -30%) was significantly shorter than for other patients (p = 0.007). Preoperative ΔFMI was not a prognostic factor but FMI increased during the postoperative period (p = 0.009) in all patients. Conclusion: A large reduction in preoperative SMI was significantly associated with reduced survival after DDLT. Therefore, changes in muscle mass during the preoperative period can be considered as a prognostic factor for survival after DDLT.

NEAR REAL-TIME ESTIMATION OF GEOMAGNETIC LOCAL K INDEX FROM GYEONGZU MAGNETOMETER (경주 지자기관측소 자료를 이용한 준실시간 K 지수 산출에 관한 연구)

  • Choi, K.C.;Cho, K.S.;Moon, Y.J.;Kim, K.H.;Lee, D.Y.;Park, Y.D.;Lim, M.T.;Park, Y.S.;Lim, H.R.
    • Journal of Astronomy and Space Sciences
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    • v.22 no.4
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    • pp.431-440
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    • 2005
  • Local K-index is an indicator representing local geomagnetic activity in every 3 hour. For estimation of the local K-index, a reasonable determination of solar quiet curve (undisturbed daily variation of geomagnetic field) is quiet essential. To derive the solar quiet curve, the FMI method, which is one of representative algorithms, uses horizontal components (H and D) of 3 days magnetometer data from the previous day to the next day for a specific day. However, this method is not applicable to real time forecast since it always requires the next day data. In this study, we have devised a new method to estimate local K-index in near real-time by modifying the FMI method. The new method selects a recent quiet day whose $K_p$ indices, reported by NOAA/SEC are all lower than 3, and replace the previous day and the next day data by the recent quiet day data. We estimated 2,672 local K indices from Gyeongzu magnetometer in 2003, and then compared the indices with those from the conventional FMI method. We also compared the K indices with those from Kakioka observatory. As a result, we found that (1) K indices from the new method are nearly consistent with those of the conventional FMI method with a very high correlation (R=0.96); (2) onr local K indices also have a relatively high correlation (R=0.81) with those from Kakioka station. Our results show that the new method can be used for near real-time estimation of local K indices from Gyeongzu magnetometer.