Pub Date : 2022-09-12DOI: 10.5614/j.math.fund.sci.2022.54.1.9
D. Aldila, Tama Windyhani
This paper introduces a mathematical model for African animal trypanosomiasis (AAT) in white rhino and tsetse fly populations. The model accommodates two types of interventions, namely infection detection and ground spraying. The dynamical system properties were thoroughly investigated to show the existence of equilibrium points, backward bifurcation, and how they are related to the basic reproduction number. We found that there is a chance that AAT may die out from the population if the basic reproduction number is smaller than one. However, the possible existence of backward bifurcation implies a condition where we may have a stable endemic equilibrium, even when the basic reproduction number is smaller than one. Hence, the basic reproduction number is no longer sufficient to guarantee the disappearance of AAT from the population. Our sensitivity analysis on the basic reproduction number showed that the interventions of infection detection and ground spraying have good potential to eradicate AAT from the population. To analyze the most effective intervention as time-dependent variable, we reconstructed our model as an optimal control problem. Numerical simulations on various scenarios were conducted for the optimal control problem. Cost-effectiveness analysis using the Average Cost-Effectiveness Ratio (ACER) and the Incremental Cost-Effectiveness Ratio (ICER) methods was performed. From the cost-effectiveness analysis, we found that ground spraying is the most cost-effective intervention to combat the spread of AAT in white rhino populations.
{"title":"Backward Bifurcation Emerging from a Mathematical Model of African Animal Trypanosomiasis Disease in White Rhino Populations","authors":"D. Aldila, Tama Windyhani","doi":"10.5614/j.math.fund.sci.2022.54.1.9","DOIUrl":"https://doi.org/10.5614/j.math.fund.sci.2022.54.1.9","url":null,"abstract":"This paper introduces a mathematical model for African animal trypanosomiasis (AAT) in white rhino and tsetse fly populations. The model accommodates two types of interventions, namely infection detection and ground spraying. The dynamical system properties were thoroughly investigated to show the existence of equilibrium points, backward bifurcation, and how they are related to the basic reproduction number. We found that there is a chance that AAT may die out from the population if the basic reproduction number is smaller than one. However, the possible existence of backward bifurcation implies a condition where we may have a stable endemic equilibrium, even when the basic reproduction number is smaller than one. Hence, the basic reproduction number is no longer sufficient to guarantee the disappearance of AAT from the population. Our sensitivity analysis on the basic reproduction number showed that the interventions of infection detection and ground spraying have good potential to eradicate AAT from the population. To analyze the most effective intervention as time-dependent variable, we reconstructed our model as an optimal control problem. Numerical simulations on various scenarios were conducted for the optimal control problem. Cost-effectiveness analysis using the Average Cost-Effectiveness Ratio (ACER) and the Incremental Cost-Effectiveness Ratio (ICER) methods was performed. From the cost-effectiveness analysis, we found that ground spraying is the most cost-effective intervention to combat the spread of AAT in white rhino populations.","PeriodicalId":16255,"journal":{"name":"Journal of Mathematical and Fundamental Sciences","volume":"58 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84540019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-02DOI: 10.5614/j.math.fund.sci.2022.54.1.8
Edy Wijanarko, I. Arisbaya, P. Sumintadireja, W. Warsa, H. Grandis
Timor Island, Indonesia has complex geological structures related to its tectonic history. There is an existing subsurface geological model that is based on geophysical data. It is limited to the regional crustal scale and has a relatively low spatial resolution. The objective of our study was to delineate the sedimentary basin configuration of the area, both laterally and vertically, based on gravity data. Spectral analysis of the Bouguer anomaly allowed for anomaly enhancement by wavenumber domain filtering. Two main basins were identified from elongated low gravity anomalies that follow a SW-NE trend, i.e., the Central Basin and the Atambua Basin. The 2½D gravity modeling of selected profiles perpendicular to the regional structural direction revealed the sedimentary fills of the basins and the basement based on their densities. The Bobonaro mélanges and Viqueque sequences dominate and overlay the syn-rift (Kekneno sequences) and post-rift (Kolbano sequences) with varying lithology. These para-autochthon sediments are dominated by shale and carbonaceous rocks. Their respective thicknesses and depths of burial imply the possibility of hydrocarbon generation. The underlying basement may be associated with the Australian crust protruding from the south.
{"title":"Basin Study in Atambua, West Timor, Indonesia from Gravity Data","authors":"Edy Wijanarko, I. Arisbaya, P. Sumintadireja, W. Warsa, H. Grandis","doi":"10.5614/j.math.fund.sci.2022.54.1.8","DOIUrl":"https://doi.org/10.5614/j.math.fund.sci.2022.54.1.8","url":null,"abstract":"Timor Island, Indonesia has complex geological structures related to its tectonic history. There is an existing subsurface geological model that is based on geophysical data. It is limited to the regional crustal scale and has a relatively low spatial resolution. The objective of our study was to delineate the sedimentary basin configuration of the area, both laterally and vertically, based on gravity data. Spectral analysis of the Bouguer anomaly allowed for anomaly enhancement by wavenumber domain filtering. Two main basins were identified from elongated low gravity anomalies that follow a SW-NE trend, i.e., the Central Basin and the Atambua Basin. The 2½D gravity modeling of selected profiles perpendicular to the regional structural direction revealed the sedimentary fills of the basins and the basement based on their densities. The Bobonaro mélanges and Viqueque sequences dominate and overlay the syn-rift (Kekneno sequences) and post-rift (Kolbano sequences) with varying lithology. These para-autochthon sediments are dominated by shale and carbonaceous rocks. Their respective thicknesses and depths of burial imply the possibility of hydrocarbon generation. The underlying basement may be associated with the Australian crust protruding from the south.","PeriodicalId":16255,"journal":{"name":"Journal of Mathematical and Fundamental Sciences","volume":"74 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86341345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-30DOI: 10.5614/j.math.fund.sci.2022.54.1.7
Widodo Widodo, Farkhan Raflesia, Susanti Awaliyah, Setianingsih Setianingsih, D. Santoso, W. Parnadi, F. Fatkhan
Hybridization of algorithms can enhance the overall search capabilities to get the optimal solution. The aim of this study was to invert Time Domain Electromagnetic (TDEM) data using the Flower Pollination Algorithm (FPA) as a new inversion scheme technique. FPA was originally inspired by the fertilization process of flowers, in which pollen transfer grains from male flowers to female flowers. The modeling of TDEM data was done by combining the FPA and elitism (eFPA) techniques. The applicability was tested on forward modeling data and observed data in MATLAB 2017a. In testing the algorithm, we used a model from homogeneous half space to a multi-layer model using different parameters (resistivity and thickness). In addition, in the inversion process, we used field data with various starting model approaches. Based on the results of the TDEM data modeling, FPA and eFPA can both be applied as algorithmic techniques for inversion modeling of TDEM data. The eFPA technique gave better results than FPA.
{"title":"Flower Pollination and Elitism Algorithms for Inversion of TDEM Data","authors":"Widodo Widodo, Farkhan Raflesia, Susanti Awaliyah, Setianingsih Setianingsih, D. Santoso, W. Parnadi, F. Fatkhan","doi":"10.5614/j.math.fund.sci.2022.54.1.7","DOIUrl":"https://doi.org/10.5614/j.math.fund.sci.2022.54.1.7","url":null,"abstract":"Hybridization of algorithms can enhance the overall search capabilities to get the optimal solution. The aim of this study was to invert Time Domain Electromagnetic (TDEM) data using the Flower Pollination Algorithm (FPA) as a new inversion scheme technique. FPA was originally inspired by the fertilization process of flowers, in which pollen transfer grains from male flowers to female flowers. The modeling of TDEM data was done by combining the FPA and elitism (eFPA) techniques. The applicability was tested on forward modeling data and observed data in MATLAB 2017a. In testing the algorithm, we used a model from homogeneous half space to a multi-layer model using different parameters (resistivity and thickness). In addition, in the inversion process, we used field data with various starting model approaches. Based on the results of the TDEM data modeling, FPA and eFPA can both be applied as algorithmic techniques for inversion modeling of TDEM data. The eFPA technique gave better results than FPA.","PeriodicalId":16255,"journal":{"name":"Journal of Mathematical and Fundamental Sciences","volume":"20 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73195978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-21DOI: 10.5614/j.math.fund.sci.2022.54.1.6
I. Lister, C. Ginting, Ermi Girsang, A. Amansyah, L. Chiuman, N. L. W. E. Yanti, W. Widodo, D. T. Yusepany, R. Rizal, W. Widowati
Cirrhosis is a serious hepatic disease that occurs worldwide and is caused by progressive fibrosis in the liver. Free radicals are the major cause of reactive oxygen species (ROS) generation, which affects the balance of the liver metabolism. Piper crocatum, commonly called red betel, is widely used in ethnomedicine because it has biological capabilities, including antioxidant and anti-inflammatory properties. The present study was undertaken to examine the possibility of hepaprotective activity of red betel extract on acetaminophen (APAP)-induced HepG2 cells as the cirrhosis in vitro model. Assessment of red betel extract (RBE) was performed using the colorimetric method for the quantification of LDH, AST, and ALT. As preliminary study, a cytotoxicity assay was performed at various RBE concentrations (100.00; 50.00; 25.00; 12.50; 6.25; 3.13 μg/ml) using an MTS assay to decide the safe concentration based on cell viability. The RBE treatment did not affect cell viability, even at a high concentration (100 µg/ml, p > 0.05). RBE at concentrations 25 and 100 µg/ml successfully reduced LDH, AST, and ALT activities in the hepatotoxic model in a dose-dependent manner. In the APAP-induced hepatotoxicity model, RBE positively indicated a hepatoprotective effect and cell amelioration by a decrease in hepatotoxic markers.
肝硬化是一种严重的肝脏疾病，发生在世界各地，是由肝脏进行性纤维化引起的。自由基是活性氧(reactive oxygen species, ROS)产生的主要原因，影响肝脏代谢的平衡。藏红花，俗称红槟榔，因其具有抗氧化和抗炎等生物学特性而被广泛用于民族医学。本研究旨在探讨红槟榔提取物对对乙酰氨基酚(APAP)诱导的肝硬化HepG2细胞的肝保护作用。采用比色法定量测定LDH、AST和ALT，对红槟榔提取物(RBE)进行评估。作为初步研究，在不同浓度的RBE (100.00;50.00;25.00;12.50;6.25;3.13 μg/ml)，采用MTS法根据细胞活力确定安全浓度。RBE处理即使在高浓度(100µg/ml, p > 0.05)下也不影响细胞活力。浓度为25和100µg/ml的RBE成功地降低了肝毒性模型中LDH、AST和ALT的活性，并呈剂量依赖性。在apap诱导的肝毒性模型中，RBE通过降低肝毒性标志物积极显示出肝保护作用和细胞改善作用。
{"title":"Piper crocatum Ameliorates APAP-Induced Hepatotoxicity through Antioxidant and Anti-Inflammatory Mechanisms","authors":"I. Lister, C. Ginting, Ermi Girsang, A. Amansyah, L. Chiuman, N. L. W. E. Yanti, W. Widodo, D. T. Yusepany, R. Rizal, W. Widowati","doi":"10.5614/j.math.fund.sci.2022.54.1.6","DOIUrl":"https://doi.org/10.5614/j.math.fund.sci.2022.54.1.6","url":null,"abstract":"Cirrhosis is a serious hepatic disease that occurs worldwide and is caused by progressive fibrosis in the liver. Free radicals are the major cause of reactive oxygen species (ROS) generation, which affects the balance of the liver metabolism. Piper crocatum, commonly called red betel, is widely used in ethnomedicine because it has biological capabilities, including antioxidant and anti-inflammatory properties. The present study was undertaken to examine the possibility of hepaprotective activity of red betel extract on acetaminophen (APAP)-induced HepG2 cells as the cirrhosis in vitro model. Assessment of red betel extract (RBE) was performed using the colorimetric method for the quantification of LDH, AST, and ALT. As preliminary study, a cytotoxicity assay was performed at various RBE concentrations (100.00; 50.00; 25.00; 12.50; 6.25; 3.13 μg/ml) using an MTS assay to decide the safe concentration based on cell viability. The RBE treatment did not affect cell viability, even at a high concentration (100 µg/ml, p > 0.05). RBE at concentrations 25 and 100 µg/ml successfully reduced LDH, AST, and ALT activities in the hepatotoxic model in a dose-dependent manner. In the APAP-induced hepatotoxicity model, RBE positively indicated a hepatoprotective effect and cell amelioration by a decrease in hepatotoxic markers.","PeriodicalId":16255,"journal":{"name":"Journal of Mathematical and Fundamental Sciences","volume":"13 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84859565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-05DOI: 10.5614/j.math.fund.sci.2022.54.1.5
A. Nigwal, U. Khedlekar, Leena Sharma, N. Gupta
In this study, we developed a trade credit policy for a three-layer supply chain consisting of a supplier, a manufacturer and a retailer. We propose an optimal production rate and selling price for the manufacturer and the retailer under an imperfect production system. The suggested coordination policy optimizes the profit of each supply chain member. Two models were formulated for two real-life strategies respectively. The first one is a collaborative (integrated) system and the second one is a Stackelberg leadership system. Both strategies were analyzed for various credit periods, respectively offered by the supplier to the manufacturer, by the manufacturer to the retailer, and by the retailer to the customers, by considering price-sensitive demand and a certain replenishment rate. Finally, we concluded which strategy will be better for inventory management under the given restrictions in the form of propositions. The concavity property for the net profit function was established with respect to the selling price and the production rate, which was also described graphically and analyzed by numerical examples.
{"title":"Trade Credit Policies for Supplier, Manufacturer, and Retailer: An Imperfect Production-Inventory System with Rework","authors":"A. Nigwal, U. Khedlekar, Leena Sharma, N. Gupta","doi":"10.5614/j.math.fund.sci.2022.54.1.5","DOIUrl":"https://doi.org/10.5614/j.math.fund.sci.2022.54.1.5","url":null,"abstract":"In this study, we developed a trade credit policy for a three-layer supply chain consisting of a supplier, a manufacturer and a retailer. We propose an optimal production rate and selling price for the manufacturer and the retailer under an imperfect production system. The suggested coordination policy optimizes the profit of each supply chain member. Two models were formulated for two real-life strategies respectively. The first one is a collaborative (integrated) system and the second one is a Stackelberg leadership system. Both strategies were analyzed for various credit periods, respectively offered by the supplier to the manufacturer, by the manufacturer to the retailer, and by the retailer to the customers, by considering price-sensitive demand and a certain replenishment rate. Finally, we concluded which strategy will be better for inventory management under the given restrictions in the form of propositions. The concavity property for the net profit function was established with respect to the selling price and the production rate, which was also described graphically and analyzed by numerical examples.","PeriodicalId":16255,"journal":{"name":"Journal of Mathematical and Fundamental Sciences","volume":"20 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88056186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-01DOI: 10.5614/j.math.fund.sci.2022.54.1.4
U. Ma’rufah, T. June, Ashehad Ashween Ali, A. Faqih, Y. Koesmaryono, C. Stiegler, A. Knohl
Climatic conditions and land cover play crucial roles in influencing the process of carbon uptake through vegetation. This study aimed to analyze the effect of climate variability on carbon uptake of four different land covers in Jambi Province, Indonesia. The four land cover types studied were: forest, shrub, grass, and irrigated soybean, based on Community Land Model version 5. Forest was found to have the highest net primary production (NPP) compared to the other land covers. Seasonal climate variability showed no major effect on NPP and gross primary production (GPP). However, GPP and NPP experienced significant declines during El Niño Southern Oscillation (ENSO), particularly in 2015. Carbon use efficiency (CUE = NPP/GPP) was also affected by ENSO, where CUE decreased during El Niño, particularly in October and November with an increased number of days without rainfall. In addition, the difference between latent (LE) and sensible heat (H) flux, denoted as (LE-H), decreased from August to November. This difference was highly correlated with NPP. This result indicates that when water supply is low, stomata will close, thereby reducing photosynthesis and transpiration, and allocating more of the available energy to sensible heat flux rather than latent heat flux.
气候条件和土地覆盖在影响植被吸收碳的过程中起着至关重要的作用。本研究旨在分析气候变率对印度尼西亚占碑省四种不同土地覆盖的碳吸收的影响。基于社区土地模型第5版，研究了森林、灌木、草地和灌溉大豆四种土地覆盖类型。与其他土地覆盖相比，森林具有最高的净初级生产(NPP)。季节气候变率对NPP和gross primary production (GPP)无显著影响。然而，在厄尔Niño南方涛动(ENSO)期间，GPP和NPP出现了显著下降，尤其是在2015年。碳利用效率(CUE = NPP/GPP)也受到ENSO的影响，在厄尔尼诺Niño期间，CUE下降，特别是在10月和11月，无雨天数增加。潜热通量(LE)与感热通量(H)之差(LE-H)从8月到11月逐渐减小。这种差异与NPP高度相关。这说明当供水量不足时，气孔会关闭，从而减少光合作用和蒸腾作用，将更多的可用能量分配给感热通量而不是潜热通量。
{"title":"Vulnerability of Primary Productivity and Its Carbon Use Efficiency to Unfavorable Climatic Conditions in Jambi Province, Indonesia","authors":"U. Ma’rufah, T. June, Ashehad Ashween Ali, A. Faqih, Y. Koesmaryono, C. Stiegler, A. Knohl","doi":"10.5614/j.math.fund.sci.2022.54.1.4","DOIUrl":"https://doi.org/10.5614/j.math.fund.sci.2022.54.1.4","url":null,"abstract":"Climatic conditions and land cover play crucial roles in influencing the process of carbon uptake through vegetation. This study aimed to analyze the effect of climate variability on carbon uptake of four different land covers in Jambi Province, Indonesia. The four land cover types studied were: forest, shrub, grass, and irrigated soybean, based on Community Land Model version 5. Forest was found to have the highest net primary production (NPP) compared to the other land covers. Seasonal climate variability showed no major effect on NPP and gross primary production (GPP). However, GPP and NPP experienced significant declines during El Niño Southern Oscillation (ENSO), particularly in 2015. Carbon use efficiency (CUE = NPP/GPP) was also affected by ENSO, where CUE decreased during El Niño, particularly in October and November with an increased number of days without rainfall. In addition, the difference between latent (LE) and sensible heat (H) flux, denoted as (LE-H), decreased from August to November. This difference was highly correlated with NPP. This result indicates that when water supply is low, stomata will close, thereby reducing photosynthesis and transpiration, and allocating more of the available energy to sensible heat flux rather than latent heat flux.","PeriodicalId":16255,"journal":{"name":"Journal of Mathematical and Fundamental Sciences","volume":"31 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89784735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-02DOI: 10.5614/j.math.fund.sci.2022.54.1.3
Halawa Ernwati, Y. Bindar, A. Purqon, W. Srigutomo
Human and industrial activities produce air pollutants that can cause a decline in air quality. In urban areas, transportation activities are the main source of air pollution. One of the emitted air pollutants produced by transportation is carbon monoxide (CO). The understanding of CO concentration is crucial since its overabundance beyond a certain limit will have a negative impact on human health and the environment. In this study, the support vector regression (SVR) method was used to predict CO concentration. The purpose of this study was to predict the hourly CO concentration in the Ujung Berung district, Bandung City, West Java, Indonesia with optimal prediction accuracy. An experiment was carried out by modeling the CO concentration with varying kernel parameter values to obtain accurate prediction results. The suitability of the values between error (ɛ), a trade-off constant (C), and variation mismatch (γ) is vital to obtain optimal prediction results. The results showed that the best prediction accuracy value was 97.68% with kernel parameter values ɛ = 0.02, γ = 30, and C = 0.006. These results may lead to proper decision making on environmental issues and can improve air pollution control strategies.
人类和工业活动产生的空气污染物会导致空气质量下降。在城市地区，交通活动是空气污染的主要来源。交通运输产生的大气污染物之一是一氧化碳(CO)。对CO浓度的了解是至关重要的，因为CO浓度超过一定限度就会对人类健康和环境产生负面影响。本研究采用支持向量回归(SVR)方法对CO浓度进行预测。本研究的目的是预测每小时CO浓度在Ujung Berung地区，万隆市，西爪哇，印度尼西亚，以最佳的预测精度。为了获得准确的预测结果，对不同核参数值的CO浓度进行了模拟实验。误差(j)、权衡常数(C)和变异失配(γ)之间值的适宜性对于获得最佳预测结果至关重要。结果表明，当核参数值为ε = 0.02， γ = 30, C = 0.006时，最佳预测准确率为97.68%。这些结果可能会导致对环境问题的正确决策，并可以改善空气污染控制策略。
{"title":"Prediction of Carbon Monoxide Concentration with Variation of Support Vector Regression Kernel Parameter Value","authors":"Halawa Ernwati, Y. Bindar, A. Purqon, W. Srigutomo","doi":"10.5614/j.math.fund.sci.2022.54.1.3","DOIUrl":"https://doi.org/10.5614/j.math.fund.sci.2022.54.1.3","url":null,"abstract":"Human and industrial activities produce air pollutants that can cause a decline in air quality. In urban areas, transportation activities are the main source of air pollution. One of the emitted air pollutants produced by transportation is carbon monoxide (CO). The understanding of CO concentration is crucial since its overabundance beyond a certain limit will have a negative impact on human health and the environment. In this study, the support vector regression (SVR) method was used to predict CO concentration. The purpose of this study was to predict the hourly CO concentration in the Ujung Berung district, Bandung City, West Java, Indonesia with optimal prediction accuracy. An experiment was carried out by modeling the CO concentration with varying kernel parameter values to obtain accurate prediction results. The suitability of the values between error (ɛ), a trade-off constant (C), and variation mismatch (γ) is vital to obtain optimal prediction results. The results showed that the best prediction accuracy value was 97.68% with kernel parameter values ɛ = 0.02, γ = 30, and C = 0.006. These results may lead to proper decision making on environmental issues and can improve air pollution control strategies.","PeriodicalId":16255,"journal":{"name":"Journal of Mathematical and Fundamental Sciences","volume":"17 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87373942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-02-28DOI: 10.5614/j.math.fund.sci.2022.54.1.2
M. Barulina, D. Kondratov, Sofia Galkina, O. Markelova
In the present work, the equations of motion of a thin orthotropic nanoplate were obtained based on the new modified couple stress theory and the third-order shear deformation plate theory. The nanoplate was considered as a size-dependent orthotropic plate. The governing equations were derived using the dynamic version of Hamilton’s principle and natural boundary conditions were formulated. An analytical solution in the form of a double Fourier series was obtained for a simply supported rectangular nanoplate. The eigenvalue problem was set and solved. It was analytically shown that the displacements of the median surface points in the plane of the plate do not depend on the material length scale parameters in the same directions; these in-plane directional displacements depend on the material length scale parameter in the out-of-plane direction only. On the other hand, the out-of-plane directional displacement depends on the length scale parameter in the plane directions only. The cross-section rotation angles depend on all length scale parameters. It was shown that the size-dependent parameters only have a noticeable effect on the deformed state of the plate if their order is not less than the order (plate height)-1.
{"title":"Analytical Solution for Bending and Free Vibrations of an Orthotropic Nanoplate based on the New Modified Couple Stress Theory and the Third-order Plate Theory","authors":"M. Barulina, D. Kondratov, Sofia Galkina, O. Markelova","doi":"10.5614/j.math.fund.sci.2022.54.1.2","DOIUrl":"https://doi.org/10.5614/j.math.fund.sci.2022.54.1.2","url":null,"abstract":"In the present work, the equations of motion of a thin orthotropic nanoplate were obtained based on the new modified couple stress theory and the third-order shear deformation plate theory. The nanoplate was considered as a size-dependent orthotropic plate. The governing equations were derived using the dynamic version of Hamilton’s principle and natural boundary conditions were formulated. An analytical solution in the form of a double Fourier series was obtained for a simply supported rectangular nanoplate. The eigenvalue problem was set and solved. It was analytically shown that the displacements of the median surface points in the plane of the plate do not depend on the material length scale parameters in the same directions; these in-plane directional displacements depend on the material length scale parameter in the out-of-plane direction only. On the other hand, the out-of-plane directional displacement depends on the length scale parameter in the plane directions only. The cross-section rotation angles depend on all length scale parameters. It was shown that the size-dependent parameters only have a noticeable effect on the deformed state of the plate if their order is not less than the order (plate height)-1.","PeriodicalId":16255,"journal":{"name":"Journal of Mathematical and Fundamental Sciences","volume":"49 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81615485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-02-28DOI: 10.5614/j.math.fund.sci.2022.54.1.1
S. D. Isro, Soehianie Agoes, A. Iskandar
We report a study on the reflective performance of a dielectric meta-lattice formed by a one-dimensional periodic arrangement of silicon nanotubes. It was found that switching from transparent state to reflective state can be done by simply varying one optical parameter of the meta-lattice. The meta-lattice was shown to be capable of providing near-zero and near-unity reflectance at any desired wavelength, even in oblique incidence cases. The results are thus very promising for the development of future optical devices.
{"title":"Dielectric Meta-lattices with Tunable Reflectivity","authors":"S. D. Isro, Soehianie Agoes, A. Iskandar","doi":"10.5614/j.math.fund.sci.2022.54.1.1","DOIUrl":"https://doi.org/10.5614/j.math.fund.sci.2022.54.1.1","url":null,"abstract":"We report a study on the reflective performance of a dielectric meta-lattice formed by a one-dimensional periodic arrangement of silicon nanotubes. It was found that switching from transparent state to reflective state can be done by simply varying one optical parameter of the meta-lattice. The meta-lattice was shown to be capable of providing near-zero and near-unity reflectance at any desired wavelength, even in oblique incidence cases. The results are thus very promising for the development of future optical devices.","PeriodicalId":16255,"journal":{"name":"Journal of Mathematical and Fundamental Sciences","volume":"192 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73474244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-18DOI: 10.5614/j.math.fund.sci.2021.53.3.10
C. Ginting, I. Lister, Ermi Girsang, M. Mutia, Y. E. P. Lubis, A. Amalia, W. Widodo, D. Artie, R. Rizal, W. Widowati
Preeclampsia is a pregnancy complication characterized by proteinuria, hypertension, hypoxia as well an increased systemic inflammatory response. It affects 5 to 10% of all births and is a leading factor in fetal and maternal morbidity and death. Ficus elastica L. leaves are known to have natural compounds with anti-inflammatory and antioxidant properties. This research assessed the potential of F. elastica leaf extract (FEE) as anti-inflammatory agent in a hypoxic-induced human endothelial cell line (EA.hy926) as preeclampsia model. F. elastica leaves were extracted using 70% ethanol. Cytotoxic assay of the FEE in different concentrations (3.13 to 100 µg/ml) against EA.hy926 was done using MTS assay. The FEE’s anti-inflammatory activity was measured with ELISA for the TNF-α and IL-10 parameters. The FEE did not cause cytotoxicity to the EA.hy926 cells, with viability above 80% at the highest concentration. The FEE could decrease the pro-inflammatory TNF-α level and increase the IL-10 level as anti-inflammatory markers in the preeclampsia model at significance level p < 0.05. This study suggests that FEE is a safe alternative herbal medicine for preeclampsia treatment.
{"title":"Ficus elastica Leaf Extract Effect Toward IL-10 and TNF-α as a Preeclampsia Model on Hypoxia-induced EA.hy926","authors":"C. Ginting, I. Lister, Ermi Girsang, M. Mutia, Y. E. P. Lubis, A. Amalia, W. Widodo, D. Artie, R. Rizal, W. Widowati","doi":"10.5614/j.math.fund.sci.2021.53.3.10","DOIUrl":"https://doi.org/10.5614/j.math.fund.sci.2021.53.3.10","url":null,"abstract":"Preeclampsia is a pregnancy complication characterized by proteinuria, hypertension, hypoxia as well an increased systemic inflammatory response. It affects 5 to 10% of all births and is a leading factor in fetal and maternal morbidity and death. Ficus elastica L. leaves are known to have natural compounds with anti-inflammatory and antioxidant properties. This research assessed the potential of F. elastica leaf extract (FEE) as anti-inflammatory agent in a hypoxic-induced human endothelial cell line (EA.hy926) as preeclampsia model. F. elastica leaves were extracted using 70% ethanol. Cytotoxic assay of the FEE in different concentrations (3.13 to 100 µg/ml) against EA.hy926 was done using MTS assay. The FEE’s anti-inflammatory activity was measured with ELISA for the TNF-α and IL-10 parameters. The FEE did not cause cytotoxicity to the EA.hy926 cells, with viability above 80% at the highest concentration. The FEE could decrease the pro-inflammatory TNF-α level and increase the IL-10 level as anti-inflammatory markers in the preeclampsia model at significance level p < 0.05. This study suggests that FEE is a safe alternative herbal medicine for preeclampsia treatment.","PeriodicalId":16255,"journal":{"name":"Journal of Mathematical and Fundamental Sciences","volume":"40 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73240935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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