Sigma Journal of Engineering and Natural Sciences-Sigma Muhendislik ve Fen Bilimleri Dergisi最新文献_第2页

On orthogonal fuzzy b-metric-like spaces and their fixed point application 正交模糊类b-度量空间及其不动点应用

Sigma Journal of Engineering and Natural Sciences-Sigma Muhendislik ve Fen Bilimleri Dergisi Pub Date : 2023-01-01 DOI: 10.14744/sigma.2023.00111

Fahim UDDIN

引用次数: 0

Robust methods for detecting bad leverage point in logistic regression 逻辑回归中不良杠杆点检测的鲁棒方法

Sigma Journal of Engineering and Natural Sciences-Sigma Muhendislik ve Fen Bilimleri Dergisi Pub Date : 2023-01-01 DOI: 10.14744/sigma.2023.00108

Ebru GÜNDOĞAN AŞIK

引用次数: 0

TRIZ approach to the relevant problem for the transport of assay tubes: A case study on family health centers in Amasya TRIZ对分析试管运输相关问题的处理方法:以Amasya家庭保健中心为例

Sigma Journal of Engineering and Natural Sciences-Sigma Muhendislik ve Fen Bilimleri Dergisi Pub Date : 2023-01-01 DOI: 10.14744/sigma.2023.00110

Erman ALBAYRAK

引用次数: 0

Isolation of kerosene-degrading bacteria from soil samples and determination of optimal growth conditions 土壤样品中煤油降解菌的分离及最佳生长条件的确定

Sigma Journal of Engineering and Natural Sciences-Sigma Muhendislik ve Fen Bilimleri Dergisi Pub Date : 2023-01-01 DOI: 10.14744/sigma.2023.001201

Yerlan BEKESHEV

{"title":"Isolation of kerosene-degrading bacteria from soil samples and determination of optimal growth conditions","authors":"Yerlan BEKESHEV","doi":"10.14744/sigma.2023.001201","DOIUrl":"https://doi.org/10.14744/sigma.2023.001201","url":null,"abstract":"Bacteria capable of decomposing hydrocarbon rocket power kerosene T-1 were isolated and studied. In the course of the studies, 30 isolates of microbial cultures were isolated from soils contaminated with hydrocarbon rocket fuel, of which 9 isolates were selected that actively assimilate kerosene T-1 as the only headwater of carbon. The strains that showed the best results in these screening analyses on four nutrient media with a concentration of T-1 kerosene 1% (10 g/kg) grow well 9 isolates of culture microorganisms: (cid:0) 4, 8, 14, 23, 5, 18, 20, 25 and yeast (cid:0) 12/5. Isolates on a medium with a concentration of T-1 kerosene 2% (20 g/kg) and 5% (50 g/kg) showed good growth in bacterial cultures (cid:0) 5, 18, 20, 25, and yeast (cid:0) 12/5. The selected microorganisms were identified by physiological and biochemical characteristics: (cid:0) 5 – Arthrobacter sp., (cid:0)18 – Acinetobacter calcoaceticum, (cid:0)20 – Bacillus sp., (cid:0)25-Micrococcus roseus, (cid:0) 12/5-Candida sp. Cultivation conditions for isolated microorganisms were created. It has been established that the optimal development temperature for the culture of Arthrobacter sp. 5 is 25-30°C, Acinetobacter calcoaceticum. 18 is 30-35 °(cid:0) , Micrococcus roseus. 25 is 25-37 °(cid:0). The optimal duration of cultivation of Candida sp. 12/5 is 1 day, for the rest of the studied cultures - 2 days.","PeriodicalId":45000,"journal":{"name":"Sigma Journal of Engineering and Natural Sciences-Sigma Muhendislik ve Fen Bilimleri Dergisi","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135610013","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}

引用次数: 0

Wong-Zakai approximation for stochastic models of smoking 吸烟随机模型的Wong-Zakai近似

Sigma Journal of Engineering and Natural Sciences-Sigma Muhendislik ve Fen Bilimleri Dergisi Pub Date : 2023-01-01 DOI: 10.14744/sigma.2023.00114

Süleyman ŞENGÜL

{"title":"Wong-Zakai approximation for stochastic models of smoking","authors":"Süleyman ŞENGÜL","doi":"10.14744/sigma.2023.00114","DOIUrl":"https://doi.org/10.14744/sigma.2023.00114","url":null,"abstract":"In this study, Wong-Zakai approximation method has been used to obtain approximate solutions for two compartmental models of smoking dynamics. Stratonovich stochastic differential equation systems are obtained for these two stochastic models for the application of Wong-Zakai method. Wong-Zakai method is used together with the predictor-corrector deterministic approximation method where Adams-Bashforth method is used as the predictor pair and Adams-Moulton method is used as the corrector pair. Stochastic Runge-Kutta IV, Euler-Maruyama and stochastic Runge-Kutta strong order 1.0 schemes are also used to investigate the models and the results are compared to the results from Wong-Zakai approximation. The comparison shows that Wong-Zakai method is a reliable tool for the analysis of stochastic models and can be considered as an alternative investigation method for modeling studies. Solution graphs, error graphs and numerical results have been given as evidence to show that Wong-Zakai method can also be a reliable method for analyzing various models. An alternate technique for parallelizing the algorithm has also been given to decrease CPU times for Wong-Zakai method. This technique is suggested to overcome the extra calculation load that comes with Wong-Zakai method.","PeriodicalId":45000,"journal":{"name":"Sigma Journal of Engineering and Natural Sciences-Sigma Muhendislik ve Fen Bilimleri Dergisi","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135260972","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}

引用次数: 0

Artificial neural network and multiple regression analysis for predicting abrasive water jet cutting of al 7068 aerospace alloy 人工神经网络和多元回归分析预测al 7068航空合金磨料水射流切割

Sigma Journal of Engineering and Natural Sciences-Sigma Muhendislik ve Fen Bilimleri Dergisi Pub Date : 2023-01-01 DOI: 10.14744/sigma.2023.00102

Fuat KARTAL

{"title":"Artificial neural network and multiple regression analysis for predicting abrasive water jet cutting of al 7068 aerospace alloy","authors":"Fuat KARTAL","doi":"10.14744/sigma.2023.00102","DOIUrl":"https://doi.org/10.14744/sigma.2023.00102","url":null,"abstract":"This study aims to predict machinability and high performance optimum surface roughness ( R a ) by developing multiple regression models and artificial neural network (ANN) model for abrasive waterjet cutting (AWJC) of Aluminum 7068 alloy. Important basic processing parameters such as pump pressure (3500-4000 Bar), nozzle distance (2-5 mm), abrasive flow rate (200-350 g/min), abrasive grain size (100-110, mesh), and nozzle traverse speed (240-300 mm/min) were selected in the study. To examine the effects of these parameters on R a , 32 experiments were conducted using the L32 orthogonal array, and data was collected. Additionally, the most important factors and interactions affecting R a were determined using multiple regression analysis and analysis of variance (ANOVA). The ANN model was designed to have multiple hidden layers using MATLAB. The model was trained and evaluated using experimental data, and its performance was measured using mean squared error (MSE) and mean absolute error (MAE). The model was optimized using hyper parameter tuning and cross-validation techniques. As a result, it was determined that the best R2 value of 95.65% from the multiple regression models created to estimate the surface roughness could be obtained from the linear regression model. While selecting the optimum process parameters for AWJC, it was determined that nozzle rotation speed, abrasive grain size and flow rate had the greatest effect by 35.5%, 25.4% and 21.9%, respectively. The optimized ANN model showed high accuracy in predicting R a for different input parameter combinations. This study provides a reliable and efficient tool for predicting R a in AWJC, which can contribute to improving process planning and control.","PeriodicalId":45000,"journal":{"name":"Sigma Journal of Engineering and Natural Sciences-Sigma Muhendislik ve Fen Bilimleri Dergisi","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136368240","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}

引用次数: 0

The effect of marble waste in the production of low-temperature porous material from Alkali-activated fly ash 大理石废料在碱活化粉煤灰生产低温多孔材料中的作用

Sigma Journal of Engineering and Natural Sciences-Sigma Muhendislik ve Fen Bilimleri Dergisi Pub Date : 2023-01-01 DOI: 10.14744/sigma.2023.00122

Hakan CENGIZLER

{"title":"The effect of marble waste in the production of low-temperature porous material from Alkali-activated fly ash","authors":"Hakan CENGIZLER","doi":"10.14744/sigma.2023.00122","DOIUrl":"https://doi.org/10.14744/sigma.2023.00122","url":null,"abstract":"The production of low-cost open-pore ceramic materials from fly ash (FA) and marble waste (MW) was investigated.The effect of MW (5-40 wt.%) onthe open porosity was determined. To reduce the sintering temperature and improve the properties of porous materials, the mixtures were activated with an alkali solution. Samples pressed from FA and FA+MW mixtures were sintered at low temperature (900 °C), but sufficient strength could not be obtained. However, when these mixtureswere subjected to alkali activation, pressed and sintered at 900 °C, sufficient strength and porosity values were reached. The open porosity of the MW neat specimen was 12.70%, but it increased up to 39.91% at 40 wt.% MW, which was the highest ratio used in the literature. The main phase structure was nepheline at 0-20 wt.% MW, but gehlenite became the dominant phase at 40 wt. % MW. The compressive and flexural strength values of 40 wt.% MW added specimen was determined to be 12 and 5.35 MPa, respectively.The open-pore ceramic of high MW ratio, produced by this new alternative route, has the potential for use in water purification membranes for macro filtration purposes.","PeriodicalId":45000,"journal":{"name":"Sigma Journal of Engineering and Natural Sciences-Sigma Muhendislik ve Fen Bilimleri Dergisi","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135660099","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}

引用次数: 0

Observation of experts, attitudes through multi-criteria decision-making 观察专家的态度，通过多标准决策

Sigma Journal of Engineering and Natural Sciences-Sigma Muhendislik ve Fen Bilimleri Dergisi Pub Date : 2023-01-01 DOI: 10.14744/sigma.2023.00112

Asma MAHMOOD

{"title":"Observation of experts, attitudes through multi-criteria decision-making","authors":"Asma MAHMOOD","doi":"10.14744/sigma.2023.00112","DOIUrl":"https://doi.org/10.14744/sigma.2023.00112","url":null,"abstract":"The aim of this paper is to obtain optimum fuzzy soft constants through multi-criteria decision-making approaches. TOPSIS and VIKOR are utilized for this purpose and results are compared with those obtained through Bonferroni mean. The hesitant fuzzy soft set is taken as initial data in decision-making methods. Hesitant fuzzy Bonferroni means and distance measures for TOPSIS and VIKOR are calculated in the structure of hesitant fuzzy set and hesitant fuzzy soft set. OFSCs are chosen from the constants which rank the alternatives in the decision-making process. By using the system of linear differential equations based on OFSCs, the future approach of people with respect to their decisions is analyzed and is observed through phase portrait and a line graph of that system of differential equations. To explain the proposed idea, explanative examples for two techniques are also given. These examples illustrate that if two persons select the two different alternatives, they do not favor each other after that decision. Cite this article as: Mahmood A, Abbas M, Murtaza G. Observation of experts, attitudes through multi-criteria decision-making. Sigma J Eng Nat Sci 2023;41(5):926−937.","PeriodicalId":45000,"journal":{"name":"Sigma Journal of Engineering and Natural Sciences-Sigma Muhendislik ve Fen Bilimleri Dergisi","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135156205","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}

引用次数: 0