• 제목/요약/키워드: determination of model parameters

검색결과 519건 처리시간 0.029초

Morin alleviates fructose-induced metabolic syndrome in rats via ameliorating oxidative stress, inflammatory and fibrotic markers

  • Heeba, Gehan Hussein;Rabie, Esraa Mohamed;Abuzeid, Mekky Mohamed;Bekhit, Amany Abdelrehim;Khalifa, Mohamed Montaser
    • The Korean Journal of Physiology and Pharmacology
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    • 제25권3호
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    • pp.177-187
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    • 2021
  • Metabolic syndrome (MBS) is a widespread disease that has strongly related to unhealthy diet and low physical activity, which initiate more serious conditions such as obesity, cardiovascular diseases and type 2 diabetes mellitus. This study aimed to examine the therapeutic effects of morin, as one of the flavonoids constituents, which widely exists in many herbs and fruits, against some metabolic and hepatic manifestations observed in MBS rats and the feasible related mechanisms. MBS was induced in rats by high fructose diet feeding for 12 weeks. Morin (30 mg/kg) was administered orally to both normal and MBS rats for 4 weeks. Liver tissues were used for determination of liver index, hepatic expression of glucose transporter 2 (GLUT2) as well as both inflammatory and fibrotic markers. The fat/muscle ratio, metabolic parameters, systolic blood pressure, and oxidative stress markers were also determined. Our data confirmed that the administration of morin in fructose diet rats significantly reduced the elevated systolic blood pressure. The altered levels of metabolic parameters such as blood glucose, serum insulin, serum lipid profile, and oxidative stress markers were also reversed approximately to the normal values. In addition, morin treatment decreased liver index, serum liver enzyme activities, and fat/muscle ratio. Furthermore, morin relatively up-regulated GLUT2 expression, however, down-regulated NF-κB, TNF-α, and TGF-β expressions in the hepatic tissues. Here, we revealed that morin has an exquisite effect against metabolic disorders in the experimental model through, at least in part, antioxidant, anti-inflammatory, and anti-fibrotic mechanisms.

Predicting blast-induced ground vibrations at limestone quarry from artificial neural network optimized by randomized and grid search cross-validation, and comparative analyses with blast vibration predictor models

  • Salman Ihsan;Shahab Saqib;Hafiz Muhammad Awais Rashid;Fawad S. Niazi;Mohsin Usman Qureshi
    • Geomechanics and Engineering
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    • 제35권2호
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    • pp.121-133
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    • 2023
  • The demand for cement and limestone crushed materials has increased many folds due to the tremendous increase in construction activities in Pakistan during the past few decades. The number of cement production industries has increased correspondingly, and so the rock-blasting operations at the limestone quarry sites. However, the safety procedures warranted at these sites for the blast-induced ground vibrations (BIGV) have not been adequately developed and/or implemented. Proper prediction and monitoring of BIGV are necessary to ensure the safety of structures in the vicinity of these quarry sites. In this paper, an attempt has been made to predict BIGV using artificial neural network (ANN) at three selected limestone quarries of Pakistan. The ANN has been developed in Python using Keras with sequential model and dense layers. The hyper parameters and neurons in each of the activation layers has been optimized using randomized and grid search method. The input parameters for the model include distance, a maximum charge per delay (MCPD), depth of hole, burden, spacing, and number of blast holes, whereas, peak particle velocity (PPV) is taken as the only output parameter. A total of 110 blast vibrations datasets were recorded from three different limestone quarries. The dataset has been divided into 85% for neural network training, and 15% for testing of the network. A five-layer ANN is trained with Rectified Linear Unit (ReLU) activation function, Adam optimization algorithm with a learning rate of 0.001, and batch size of 32 with the topology of 6-32-32-256-1. The blast datasets were utilized to compare the performance of ANN, multivariate regression analysis (MVRA), and empirical predictors. The performance was evaluated using the coefficient of determination (R2), mean absolute error (MAE), mean squared error (MSE), mean absolute percentage error (MAPE), and root mean squared error (RMSE)for predicted and measured PPV. To determine the relative influence of each parameter on the PPV, sensitivity analyses were performed for all input parameters. The analyses reveal that ANN performs superior than MVRA and other empirical predictors, andthat83% PPV is affected by distance and MCPD while hole depth, number of blast holes, burden and spacing contribute for the remaining 17%. This research provides valuable insights into improving safety measures and ensuring the structural integrity of buildings near limestone quarry sites.

신품종 토종닭의 계통과 성별에 따른 성장 특성에 관한 연구 (A Study on Growth Pattern in a New Synthetic Korean Native Commercial Chicken by Sex and Strains)

  • 김기곤;최은식;손시환
    • 한국가금학회지
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    • 제49권4호
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    • pp.229-237
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    • 2022
  • 본 연구는 신품종 토종종계로부터 생산된 토종실용닭 4계통의 성장 특성을 규명하고 출하일령 추정에 적합한 모형을 제시하고자 실시하였다. 체중은 발생시부터 12주령까지 2주 간격으로 개체별로 측정하였으며 성장곡선의 추정은 Von Berteralanffy, Gompertz 및 Logistic 모형을 이용하였다. 분석 결과, 발생시 체중을 제외한 모든 주령에서 수컷이 암컷보다 무겁게 나타났고, 계통 간 체중은발생시, 2주령 및 6주령을 제외하고는 차이가 없는 것으로 나타났다. 모든 성장곡선 모형의 결정계수와 수정된 결정계수는 97.4~99.7로 높은 적합도를 나타내었다. 성장곡선 모수 중성숙체중과 성장률은 수컷이 암컷보다 높게 나타났고, 성숙률은 암컷과 수컷이 비슷한 값을 보였다. 변곡점은 모형과 계통 별 차이가 있으나 암컷은 약 7주령, 수컷은 8~9주령으로 나타나 성별 간 10일 정도의 차이를 나타내었다. 성장곡선 모형의 거의 대부분은 실제 체중과 잘 일치하나, Von Bertalanffy 모형에서 수컷의 체중이 실제 체중과 다소의 차이를 보였다. 출하일령 예측을 위한 회귀함수의 결정계수는 0.9583~0.9746으로 나타나 예측 값에 대한 신뢰도가 높게 나타났다. 성장 곡선과 회귀식을 사용하여 추정한 주령 별 체중 값은 8주령과 10주령은 회귀식을 이용한 추정 값이, 12주령 체중은 Logistic 모형으로 추정한 값이 실제 체중과 가장 비슷하게 나타났다. 이러한 성장곡선에 따른 토종닭의 2 kg 도달일령의 평균 예측일수는 수컷이 62.0~64.6일, 암컷은 74.9~78.6일로 추정된다.

전주천 상류부의 서식처 적합도 지수 및 생태유량 산정 (Estimation of Ecological Flow and Habitat Suitability Index at Jeonju-Cheon Upstream)

  • 김경오;박영기;강재일;이병석
    • 대한환경공학회지
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    • 제38권2호
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    • pp.47-55
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    • 2016
  • 본 연구에서는 유량점증방법론에 입각하여 물리 서식처 모의 시스템의 기반을 둔 2차원 수리 및 서식처 모의인 River2D를 적용하였다. 대상 지점은 전주천 상류부이며, 수리모의 결과에 대한 비교는 갈수량 조건에서 검정된 HEC-RAS 수리모의 결과를 바탕으로 River2D와 유속, 수심 모의 결과를 비교, 평가하였다. 그 결과 유속의 RMSE는 0.18, NSE는 0.71, 결정계수는 0.78이고, 수심의 RMSE는 0.02, NSE는 0.71, 결정계수는 0.73으로 수리모의 결과가 실측치에 잘 반영되는 것으로 평가된다. 서식처 적합도 지수를 구축하기 위해 선정한 대표 어종은 10년간 어류 모니터링을 통하여 가장 출현빈도가 높은 피라미, 쉬리 어종에 대하여 선정하였다. 또한 평수량, 조건에서의 서식처 적합도 지수를 바탕으로 가중가용면적-유량 관계곡선을 산출하였으며, 한강 및 금강 수계에서 적합도 지수를 구축한 강형식(2010)의 지수를 가지고 모의한 결과와 비교, 평가하였다. 생태유량 산정 결과 피라미는 $1.5{\sim}2.0m^3/s$ 쉬리는 $1.8{\sim}2.0m^3/s$으로 산정되었다. 대상유역의 수질, 하도 구성, 생물 다양성 등이 매우 양호한 생태이고, 모의 결과 값을 유황분석과 비교해볼 때, 산정된 어류별 생태유량은 전주천 상류부에 적합한 것으로 평가된다.

B-spline polynomials models for analyzing growth patterns of Guzerat young bulls in field performance tests

  • Ricardo Costa Sousa;Fernando dos Santos Magaco;Daiane Cristina Becker Scalez;Jose Elivalto Guimaraes Campelo;Clelia Soares de Assis;Idalmo Garcia Pereira
    • Animal Bioscience
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    • 제37권5호
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    • pp.817-825
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    • 2024
  • Objective: The aim of this study was to identify suitable polynomial regression for modeling the average growth trajectory and to estimate the relative development of the rib eye area, scrotal circumference, and morphometric measurements of Guzerat young bulls. Methods: A total of 45 recently weaned males, aged 325.8±28.0 days and weighing 219.9±38.05 kg, were evaluated. The animals were kept on Brachiaria brizantha pastures, received multiple supplementations, and were managed under uniform conditions for 294 days, with evaluations conducted every 56 days. The average growth trajectory was adjusted using ordinary polynomials, Legendre polynomials, and quadratic B-splines. The coefficient of determination, mean absolute deviation, mean square error, the value of the restricted likelihood function, Akaike information criteria, and consistent Akaike information criteria were applied to assess the quality of the fits. For the study of allometric growth, the power model was applied. Results: Ordinary polynomial and Legendre polynomial models of the fifth order provided the best fits. B-splines yielded the best fits in comparing models with the same number of parameters. Based on the restricted likelihood function, Akaike's information criterion, and consistent Akaike's information criterion, the B-splines model with six intervals described the growth trajectory of evaluated animals more smoothly and consistently. In the study of allometric growth, the evaluated traits exhibited negative heterogeneity (b<1) relative to the animals' weight (p<0.01), indicating the precocity of Guzerat cattle for weight gain on pasture. Conclusion: Complementary studies of growth trajectory and allometry can help identify when an animal's weight changes and thus assist in decision-making regarding management practices, nutritional requirements, and genetic selection strategies to optimize growth and animal performance.

Determination of Optimal Scan Time for the Measurement of Downstream Metabolites in Hyperpolarized 13C MRSI

  • Lee, Hansol;Lee, Joonsung;Joe, Eunhae;Yang, Seungwook;Choi, Young-suk;Wang, Eunkyung;Song, Ho-Taek;Kim, Dong-Hyun
    • Investigative Magnetic Resonance Imaging
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    • 제19권4호
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    • pp.212-217
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    • 2015
  • Purpose: For a single time-point hyperpolarized $^{13}C$ magnetic resonance spectroscopy imaging (MRSI) of animal models, scan-time window after injecting substrates is critical in terms of signal-to-noise ratio (SNR) of downstream metabolites. Pre-scans of time-resolved magnetic resonance spectroscopy (MRS) can be performed to determine the scan-time window. In this study, based on two-site exchange model, protocol-specific simulation approaches were developed for $^{13}C$ MRSI and the optimal scan-time window was determined to maximize the SNR of downstream metabolites. Materials and Methods: The arterial input function and conversion rate constant from injected substrates (pyruvate) to downstream metabolite (lactate) were precalibrated, based on pre-scans of time-resolved MRS. MRSI was simulated using two-site exchange model with considerations of scan parameters of MRSI. Optimal scan-time window for mapping lactate was chosen from simulated lactate intensity maps. The performance was validated by multiple in vivo experiments of BALB/C nude mice with MDA-MB-231 breast tumor cells. As a comparison, MRSI were performed with other scan-time windows simply chosen from the lactate signal intensities of pre-scan time-resolved MRS. Results: The optimal scan timing for our animal models was determined by simulation, and was found to be 15 s after injection of the pyruvate. Compared to the simple approach, we observed that the lactate peak signal to noise ratio (PSNR) was increased by 230%. Conclusion: Optimal scan timing to measure downstream metabolites using hyperpolarized $^{13}C$ MRSI can be determined by the proposed protocol-specific simulation approaches.

Neural-based prediction of structural failure of multistoried RC buildings

  • Hore, Sirshendu;Chatterjee, Sankhadeep;Sarkar, Sarbartha;Dey, Nilanjan;Ashour, Amira S.;Balas-Timar, Dana;Balas, Valentina E.
    • Structural Engineering and Mechanics
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    • 제58권3호
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    • pp.459-473
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    • 2016
  • Various vague and unstructured problems encountered the civil engineering/designers that persuaded by their experiences. One of these problems is the structural failure of the reinforced concrete (RC) building determination. Typically, using the traditional Limit state method is time consuming and complex in designing structures that are optimized in terms of one/many parameters. Recent research has revealed the Artificial Neural Networks potentiality in solving various real life problems. Thus, the current work employed the Multilayer Perceptron Feed-Forward Network (MLP-FFN) classifier to tackle the problem of predicting structural failure of multistoried reinforced concrete buildings via detecting the failure possibility of the multistoried RC building structure in the future. In order to evaluate the proposed method performance, a database of 257 multistoried buildings RC structures has been constructed by professional engineers, from which 150 RC structures were used. From the structural design, fifteen features have been extracted, where nine features of them have been selected to perform the classification process. Various performance measures have been calculated to evaluate the proposed model. The experimental results established satisfactory performance of the proposed model.

Determination of structural performance of 3D steel pipe rack suspended scaffolding systems

  • Arslan, Guray;Sevim, Baris;Bekiroglu, Serkan
    • Structural Engineering and Mechanics
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    • 제64권5호
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    • pp.671-681
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    • 2017
  • This study investigates the structural performance of 3D steel pipe rack suspended scaffolding systems. For the purpose, a standard full scale 3D steel pipe rack suspended scaffolding system considering two frames, two plane trusses, purlins and wooden floor is constructed in the laboratory. A developed load transmission system was placed in these experimental systems to distribute single loads to the center of a specific area in a step-by-step manner using a load jack. After each load increment, the displacements are measured by means of linear variable differential transducers placed in several critical points of the system. The tests are repeated for five different system conditions to determine the structural performance. The means of system conditions is the numbers of the tie bars which are used to connect plane trusses under level. Finite elements models of the 3D steel pipe rack suspended scaffolding systems considering different systems conditions are constituted using SAP2000 software to support the experimental tests and to use the models in future studies. Each of models including load transmission platform is analyzed under a single loading and the displacements are obtained. In addition, to calibrate the numerical models some uncertain parameters such as elasticity modulus of wooden floor and connection rigidity of purlins to plane trusses are assessed experimentally. The results of this work demonstrate that when increasing numbers of tie bars the displacement values are decreased. Also the results obtained from developed numerical models have harmony with those of experimental. In addition, the scaffolding system with two tie bars at the beginning and at the end of the plane truss has the optimum structural performance compared the results obtained for other scaffolding system conditions.

신재생 발전 연료전환에 따른 영동1호기 발전기/제어계 특성시험 및 모델정수 도출 (Characteristics Test and Model Parameter Determination of Generator/Excitation System of Yeongdong Unit 1 due to Conversion of Renewable Generation Fuel)

  • 문정민;이태규;신우주;김정욱
    • 전기전자학회논문지
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    • 제23권2호
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    • pp.586-593
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    • 2019
  • 본 논문은 초미세먼지 증가를 억제하고자 1972년 건설된 국내무연탄과 유류를 혼소하는 발전설비를 2017년 국내최초, 최대 용량의 신재생 발전 연료 중 하나인 순수 목재를 가공한 친환경 고형연료인 바이오매스[우드팰릿] 발전방식으로 변경하였다. 발전기 제어계 중요 설비 교체에 따른 산업부 고시 "전력계통 신뢰도 및 전기품질 유지기준" 제 32조 발전설비 신/증설 시 발전설비 특성자료를 제출에 의거 발전기 기술특성시험을 실시하였으며, 시험을 통하여 발전기/제어계 모델정수 도출 및 검증을 수행하였다. 발전기 연료변경에도 해당 발전기 설비의 성능 및 여자시스템의 전압제어특성이 양호함을 재확인하였다. 차후 화석연료를 신재생 연료로 교체하고자 하는 발전소에서 참고하는데 기여할 수 있다.

일메나이트 중 철의 선택적 염화와 선광된 TiO2의 추가 염화반응에 대한 글로벌 피팅함수 (Global Fitting Functions for Kinetics of Fe-Selective Chlorination in Ilmenite and Successive Chlorination of Beneficiated TiO2)

  • 정동규;원용선;김용하;정은진;송덕용
    • 한국재료학회지
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    • 제29권7호
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    • pp.412-424
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    • 2019
  • Global fitting functions for Fe-selective chlorination in ilmenite($FeTiO_2$) and successive chlorination of beneficiated $TiO_2$ are proposed and validated based on a comparison with experimental data collected from the literature. The Fe-selective chlorination reaction is expressed by the unreacted shrinking core model, which covers the diffusion-controlling step of chlorinated Fe gas that escapes through porous materials of beneficiated $TiO_2$ formed by Fe-selective chlorination, and the chemical reaction-controlling step of the surface reaction of unreacted solid ilmenite. The fitting function is applied for both chemical controlling steps of the unreacted shrinking core model. The validation shows that our fitting function is quite effective to fit with experimental data by minimum and maximum values of determination coefficients of $R^2$ as low as 0.9698 and 0.9988, respectively, for operating parameters such as temperature, $Cl_2$ pressure, carbon ratio and particle size that change comprehensively. The global fitting functions proposed in this study are expressed simply as exponential functions of chlorination rate(X) vs. time(t), and each of them are validated by a single equation for various reaction conditions. There is therefore a certain practical merit for the optimal process design and performance analysis for field engineers of chlorination reactions of ilmenite and $TiO_2$.