Journal of Engineering and Natural Sciences – Sigma Mühendislik ve Fen Bilimleri Dergis最新文献

Time-varying parameter estimation and adaptive Kalman filter in computer aided control application 时变参数估计和自适应卡尔曼滤波在计算机辅助控制中的应用

Journal of Engineering and Natural Sciences – Sigma Mühendislik ve Fen Bilimleri Dergis Pub Date : 2021-01-01 DOI: 10.14744/sigma.2021.00023

Levent Özbek

{"title":"Time-varying parameter estimation and adaptive Kalman filter in computer aided control application","authors":"Levent Özbek","doi":"10.14744/sigma.2021.00023","DOIUrl":"https://doi.org/10.14744/sigma.2021.00023","url":null,"abstract":"Estimating the unknown parameter vector of the system model is the most important problems in system identification. Especially in cases where the system’s parameters are timevariable, it is observed that estimations obtained using estimator have deviated from the actual values, and therefore that the estimator must be corrected to some extent. In this paper, some methods for the parameter estimation in cases where a system is modelled with ARX Autoregressive Exogenous Input) are considered. After reviewing the problems, a simulation study has been made on comparing different estimation methods. Corrected (Adaptive) Kalman Filter (CKF) gives results more accurately than Normal Kalman Filter (NKF) for time varying parameter estimation. Moreover, after an introduction to the method of minimum variance feed-back control, using this method and CKF, a heating control is done in computer aided experimental study. CKF ensures that the system is kept under control by correctly estimating the parameter that changes over time. Cite this article as: Özbek L. Time-varying parameter estimation and adaptive kalman filter in computer aided control application. Sigma J Eng Nat Sci 2021;39(4):00–00. Sigma Journal of Engineering and Natural Sciences Web page info: https://sigma.yildiz.edu.tr DOİ: 10.14744/sigma.2021.00023","PeriodicalId":15669,"journal":{"name":"Journal of Engineering and Natural Sciences – Sigma Mühendislik ve Fen Bilimleri Dergis","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90157421","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

Determination of changes in some biological properties during storage of some conventional sorbets 几种传统冰沙贮藏过程中某些生物学特性变化的测定

Journal of Engineering and Natural Sciences – Sigma Mühendislik ve Fen Bilimleri Dergis Pub Date : 2021-01-01 DOI: 10.14744/sigma.2021.00024

Lutfiye Ekici

{"title":"Determination of changes in some biological properties during storage of some conventional sorbets","authors":"Lutfiye Ekici","doi":"10.14744/sigma.2021.00024","DOIUrl":"https://doi.org/10.14744/sigma.2021.00024","url":null,"abstract":"In this study, the evil eye, engagement, linaria, rose, unripe grape and sirkencubin from traditional Turkish sorbets were stored at different temperatures (4, 20 and 37 oC) for 90 days after they were concentrated to 62 ± 1 °Brix. The effects of storage temperature and time on color parameters and the bioactive properties of traditional sorbets were investigated. Although slight differences were observed, it was determined that total phenolic content, antioxidant and antiradical activities tended to decrease during storage in general. Storage temperature and time were found to be effective on color parameters and the biological characteristics of sorbets tested. The changes in the phenolic compound profiles of the concentrated sorbets during storage (at 0th and 90th days) were detected by LC-MS / MS. The observed results show that the bioactive properties and color of the sorbets are better when low temperatures for storage are preferred. Cite this article as: Kafadar AD, Ekı̇cı̇ L, Albayrak S. Determination of changes in some biological properties during storage of some conventional sorbets. Sigma J Eng Nat Sci 2021;39(4):351–366. Sigma Journal of Engineering and Natural Sciences Web page info: https://sigma.yildiz.edu.tr DOİ: 10.14744/sigma.2021.00024","PeriodicalId":15669,"journal":{"name":"Journal of Engineering and Natural Sciences – Sigma Mühendislik ve Fen Bilimleri Dergis","volume":"91 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80536800","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: 1

Vibration suppression of a micro beam subjected to magneto-electric load 磁电负载下微梁的振动抑制

Journal of Engineering and Natural Sciences – Sigma Mühendislik ve Fen Bilimleri Dergis Pub Date : 2021-01-01 DOI: 10.14744/sigma.2021.00028

Kenan Yildirim

引用次数: 1

Monitoring of heavy metal pollution by using populus nigra and cedrus libani 黑杨和柏树对重金属污染的监测

Journal of Engineering and Natural Sciences – Sigma Mühendislik ve Fen Bilimleri Dergis Pub Date : 2021-01-01 DOI: 10.14744/sigma.2021.00025

Çiğdem ER ÇALIŞKAN

引用次数: 1

Estimation of ground types in different districts of Gümüşhane province based on the ambient vibrations H/V measurements 基于环境振动H/V测量的甘肃<s:1> <s:1> <e:1>省不同地区地面类型估算

Journal of Engineering and Natural Sciences – Sigma Mühendislik ve Fen Bilimleri Dergis Pub Date : 2021-01-01 DOI: 10.14744/sigma.2021.00026

Mahmut Sari

{"title":"Estimation of ground types in different districts of Gümüşhane province based on the ambient vibrations H/V measurements","authors":"Mahmut Sari","doi":"10.14744/sigma.2021.00026","DOIUrl":"https://doi.org/10.14744/sigma.2021.00026","url":null,"abstract":"In this study, an attempt was made to estimate the ground types for Torul, Kürtün, Kelkit, Şiran and Köse districts of Gümüşhane, Turkey, by analyzing the predominant frequency and H/V ratio from microtremor data through the single station microtremor H/V ratio of Nakamura technique. For all districts, predominant frequencies show a general distribution between 1.36 and 9.84 Hz, H/V ratios between 1.01 and 9.58. According to these variations, three transient zones can be suggested as i) Z1, stiff rock composed of gravel, sand and other soils mainly consisting of tertiary or older layers with period of 0.1 to 0.2s, ii) Z2, sandy gravel, stiff sandy clay, loam or sandy alluvial deposits whose depths are 5m or greater with period of 0.2 to 0.4s, and iii) Z3, standard grounds other than type Z1, Z2 or Z4 (alluvial deposits whose depths are 5m or greater) with period of 0.4 to 0.8s. These results s uggest that predominant period obtained from predominant frequency shows significant changes based on the soil formation, and H/V ratio highly corresponds to these subsurface properties. Soil-structure interaction can also be evaluated by considering these results and possible resonance risk can be investigated for building resonant frequency in these residential districts in the next. Thus, this type of application and evaluation of microtremor data may provide primary and useful information for other geophysical, geological and geotechnical studies such as planning the seismic resistant infrastructure, detecting the small-scale seismic risks and making a suitable and reliable seismic hazard microzonation in Gümüşhane. Cite this article as: Öztürk S, Beker Y, Sarı M, Pehlivan L. Estimation of ground types in different districts of Gümüşhane province based on the ambient vibrations H/V measurements. Sigma J Eng Nat Sci 2021;39( 4):371-394. Sigma Journal of Engineering and Natural Sciences Web page info: https://sigma.yildiz.edu.tr DOİ: 10.14744/sigma.2021.00026","PeriodicalId":15669,"journal":{"name":"Journal of Engineering and Natural Sciences – Sigma Mühendislik ve Fen Bilimleri Dergis","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87155348","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: 2

How economic freedom affect the ease of doing business? Cross-country quantile regression mixture approach 经济自由如何影响经商的便利性?跨国分位数混合回归法

Journal of Engineering and Natural Sciences – Sigma Mühendislik ve Fen Bilimleri Dergis Pub Date : 2021-01-01 DOI: 10.14744/sigma.2021.00031

Serpil Kılıç Depren

引用次数: 1

Identification of the priority regions in the customer water meters replacement using the AHP and ELECTRE methods 使用AHP和ELECTRE方法确定客户更换水表的优先区域

Journal of Engineering and Natural Sciences – Sigma Mühendislik ve Fen Bilimleri Dergis Pub Date : 2021-01-01 DOI: 10.14744/sigma.2021.00022

M. Firat

{"title":"Identification of the priority regions in the customer water meters replacement using the AHP and ELECTRE methods","authors":"M. Firat","doi":"10.14744/sigma.2021.00022","DOIUrl":"https://doi.org/10.14744/sigma.2021.00022","url":null,"abstract":"The aim of this study is to determine the priority areas in the meter replacement or rehabilitation by using an integrated methodology combining the AHP and ELECTRE I methods to reduce the non-revenue water. For this, a total of 7 criteria such as the Water Consumption Rate, Mean Meter Age, Faulty Water Meter Ratio, Region Population Rate, Customer Loyalty Percentage, Average Operating Pressure and Calibrated Age were considered. The AHP method was applied to calculate the weights of the criteria and then a model based on weights of criteria was developed using the ELECTRE I method. The model based on AHP and ELECTRE I methods was applied by taking into account the field data records for 7 criteria and the priority regions in water meter replacement were determined. This study will make significant contributions in the scope of minimizing the losses caused by the meters, reducing the costs in meter management and making the most benefit in meter replacement. Cite this article as: Yilmaz S, Firat M, Bozkurt C, Özdemir Ö. Identification of the priority regions in the customer water meters replacement using the ahp and electre methods. Sigma J Eng Nat Sci 2021;39(4):331–342. Sigma Journal of Engineering and Natural Sciences Web page info: https://sigma.yildiz.edu.tr DOİ: 10.14744/sigma.2021.00022","PeriodicalId":15669,"journal":{"name":"Journal of Engineering and Natural Sciences – Sigma Mühendislik ve Fen Bilimleri Dergis","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82476031","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: 1

Thermodynamic studies on tert-amine modified polystyrene based polymer/solvent systems by inverse gas chromatography method 反相气相色谱法研究叔胺改性聚苯乙烯基聚合物/溶剂体系的热力学

Journal of Engineering and Natural Sciences – Sigma Mühendislik ve Fen Bilimleri Dergis Pub Date : 2021-01-01 DOI: 10.14744/sigma.2021.00029

Ö. Cankurtaran

{"title":"Thermodynamic studies on tert-amine modified polystyrene based polymer/solvent systems by inverse gas chromatography method","authors":"Ö. Cankurtaran","doi":"10.14744/sigma.2021.00029","DOIUrl":"https://doi.org/10.14744/sigma.2021.00029","url":null,"abstract":"In the present work, vinyl benzyl chloride (VBC) was polymerized by using free radical polymerization. The obtained PVBC was reacted with dibutyl amine to obtain tertiary amine modified polystyrene based polymer (PVBC-Dibutyl amine). The inverse gas chromatography (IGC) method was used to examine the thermodynamic properties of the polymer. Firstly, the retention diagrams of some polar and non-polar solvents on PVBC-Dibutyl amine were obtained over a temperature range from 135 to 160° C. Then, the thermodynamic parameters, including Flory–Huggins interaction parameter, weight fraction activity coefficient, partial molar heat of sorption, and partial molar heat of mixing were determined via interactions between the polymer and selected solvents at infinite dilution. The results reveal that the alkanes are poor solvents for the polymer whereas n-butyl acetate, i-butyl acetate, ethyl acetate, n-propylbenzene, i-propylbenzene, and ethylbenzene are moderately solvents in the studied temperature range. Cite this article as: Adigüzel AC, Korkmaz B, Çakar F, Cankurtaran Ö, Şenkal BF. Thermodynamic studies on tert-amine modified polystyrene based polymer/solvent systems by inverse gas chromatography method. Sigma J Eng Nat Sci 2021;39(4):414–421. Sigma Journal of Engineering and Natural Sciences Web page info: https://sigma.yildiz.edu.tr DOİ: 10.14744/sigma.2021.00029","PeriodicalId":15669,"journal":{"name":"Journal of Engineering and Natural Sciences – Sigma Mühendislik ve Fen Bilimleri Dergis","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73941731","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