The current paper is concerned with fuzzy controllers employing neural networks to implement control over power electronics systems committed to power quality improvement in a distribution grid. An optimization method technique for tuning fuzzy PI controller gains is introduced to improve a Hybrid Indirect Matrix Converter's control with a flying capacitor three-level inverter (HIMC), and it is connected via an RL filter to the power grid (PG). The harmonics are identified by an Artificial Neural Network (ANN). The effectiveness of this method is shown in the simulation results by MATLAB/Simulink ( Simscap, simpower blocks).
{"title":"ANN Identification technique and fuzzy PI Control of a Hybrid Indirect Matrix Converter with a Flying Capacitor three level Inverter in Power Active Filtering Application","authors":"Taki Eddine AMEUR, Aissa AMEUR, Benalia ATALLAH","doi":"10.35378/gujs.1001559","DOIUrl":"https://doi.org/10.35378/gujs.1001559","url":null,"abstract":"The current paper is concerned with fuzzy controllers employing neural networks to implement control over power electronics systems committed to power quality improvement in a distribution grid. An optimization method technique for tuning fuzzy PI controller gains is introduced to improve a Hybrid Indirect Matrix Converter's control with a flying capacitor three-level inverter (HIMC), and it is connected via an RL filter to the power grid (PG). The harmonics are identified by an Artificial Neural Network (ANN). The effectiveness of this method is shown in the simulation results by MATLAB/Simulink ( Simscap, simpower blocks).","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135895721","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}
There is a growing attention in circular economy through researchers, enterprises and goverments. The idea of circular economy is not to give any harm to enviroment while using material till end of its life and keeping it as much as possible in the cycle. From this point of view, to keep the material in cycle might be possible with a well-designed logistics infrastructure. In this study, the small and medium size enterprises (SMEs) that make sales through e-commerce and the way of handling e-commerce returns are brought forward. The case study created for footware industry in Istanbul and a network design is proposed. Afterwards, a linear programming is used to calculated to minimize cost. This study gives a clear and simple solution for SMEs to minimize the cost for handling return products while keeping the returns in the cycle.
{"title":"Circular Supply Chain Network Design for E-Commerce","authors":"Batuhan KOCAOĞLU, Meliha BULUT","doi":"10.35378/gujs.1234548","DOIUrl":"https://doi.org/10.35378/gujs.1234548","url":null,"abstract":"There is a growing attention in circular economy through researchers, enterprises and goverments. The idea of circular economy is not to give any harm to enviroment while using material till end of its life and keeping it as much as possible in the cycle. From this point of view, to keep the material in cycle might be possible with a well-designed logistics infrastructure. In this study, the small and medium size enterprises (SMEs) that make sales through e-commerce and the way of handling e-commerce returns are brought forward. The case study created for footware industry in Istanbul and a network design is proposed. Afterwards, a linear programming is used to calculated to minimize cost. This study gives a clear and simple solution for SMEs to minimize the cost for handling return products while keeping the returns in the cycle.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135781970","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}
The performance of inductive learners can be negatively affected by high-dimensional datasets. To address this issue, feature selection methods are used. Selecting relevant features and reducing data dimensions is essential for having accurate machine learning models. Stability is an important criterion in feature selection. Stable feature selection algorithms maintain their feature preferences even when small variations exist in the training set. Studies have emphasized the importance of stable feature selection, particularly in cases where the number of samples is small and the dimensionality is high. In this study, we evaluated the relationship between stability measures, as well as, feature selection stability and classification accuracy, using the Pearson Product-Moment Correlation Coefficient. We conducted an extensive series of experiments using five filter and two wrapper feature selection methods, three classifiers for subset and classification performance evaluation, and eight real-world datasets taken from two different data repositories. We measured the stability of feature selection methods using a total of twelve stability metrics. Based on the results of correlation analyses, we have found that there is a lack of substantial evidence supporting a linear relationship between feature selection stability and classification accuracy. However, a strong positive correlation has been observed among several stability metrics.
{"title":"An Empirical Evaluation of Feature Selection Stability and Classification Accuracy","authors":"Mustafa Büyükkeçeci̇, M. C. Okur","doi":"10.35378/gujs.998964","DOIUrl":"https://doi.org/10.35378/gujs.998964","url":null,"abstract":"The performance of inductive learners can be negatively affected by high-dimensional datasets. To address this issue, feature selection methods are used. Selecting relevant features and reducing data dimensions is essential for having accurate machine learning models. Stability is an important criterion in feature selection. Stable feature selection algorithms maintain their feature preferences even when small variations exist in the training set. Studies have emphasized the importance of stable feature selection, particularly in cases where the number of samples is small and the dimensionality is high. In this study, we evaluated the relationship between stability measures, as well as, feature selection stability and classification accuracy, using the Pearson Product-Moment Correlation Coefficient. We conducted an extensive series of experiments using five filter and two wrapper feature selection methods, three classifiers for subset and classification performance evaluation, and eight real-world datasets taken from two different data repositories. We measured the stability of feature selection methods using a total of twelve stability metrics. Based on the results of correlation analyses, we have found that there is a lack of substantial evidence supporting a linear relationship between feature selection stability and classification accuracy. However, a strong positive correlation has been observed among several stability metrics.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139348703","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}
Nathan DİBAL, Musa SAMAİLA CHİROMA, Martha ATTAH, Sunday MANYE
Quercetin is a flavonoid with a great capability of crossing the blood-brain barrier. It is reported to exert numerous beneficial effects on both animal and human health. The study evaluates the effects of onion waste quercetin (OWQ) on the histology of the hippocampus and dentate gyrus of mice. Twenty mice were assigned into four groups (n=5). The groups were given distilled water, and OWQ at 95mg/kg, 190mg/kg, and 380mg/kg respectively for 28 days. The brain of each mouse was harvested afterward, weighed, and processed for light microscopy. The normal and degenerating cells in the dentate gyrus and hippocampus Cornu Ammonis (CA1 & CA3) were counted. The micrographs of the dentate gyrus showed normal molecular, granular, and polymorphic layers in the control mice, as well as the mice, treated with OWQ with few degenerating cells in the granular layer of OWQ-treated (190mg/kg) mice. The CA3 area of the hippocampus showed normal molecular and polymorphic layers in OWQ-treated mice. However, the granular layer of the mice that received OWQ at 190mg/kg showed numerous degenerating cells. OWQ especially at 95mg/kg was found to significantly increase the number of normal cells in the dentate gyrus and hippocampus (CA1 & CA3) of the brain compared to the control at P< .05. It also significantly decreased degenerating cells compared to the control (P< .05). In conclusion, onion waste quercetin, especially at 95mg/kg was found to maintain the pool of normal cells within the dentate gyrus and hippocampus of mice brain.
{"title":"Effects of Sub-acute Administration of Onion Waste Quercetin on the Hippocampus of Mice: A Histological Approach","authors":"Nathan DİBAL, Musa SAMAİLA CHİROMA, Martha ATTAH, Sunday MANYE","doi":"10.35378/gujs.1272285","DOIUrl":"https://doi.org/10.35378/gujs.1272285","url":null,"abstract":"Quercetin is a flavonoid with a great capability of crossing the blood-brain barrier. It is reported to exert numerous beneficial effects on both animal and human health. The study evaluates the effects of onion waste quercetin (OWQ) on the histology of the hippocampus and dentate gyrus of mice. Twenty mice were assigned into four groups (n=5). The groups were given distilled water, and OWQ at 95mg/kg, 190mg/kg, and 380mg/kg respectively for 28 days. The brain of each mouse was harvested afterward, weighed, and processed for light microscopy. The normal and degenerating cells in the dentate gyrus and hippocampus Cornu Ammonis (CA1 & CA3) were counted. The micrographs of the dentate gyrus showed normal molecular, granular, and polymorphic layers in the control mice, as well as the mice, treated with OWQ with few degenerating cells in the granular layer of OWQ-treated (190mg/kg) mice. The CA3 area of the hippocampus showed normal molecular and polymorphic layers in OWQ-treated mice. However, the granular layer of the mice that received OWQ at 190mg/kg showed numerous degenerating cells. OWQ especially at 95mg/kg was found to significantly increase the number of normal cells in the dentate gyrus and hippocampus (CA1 & CA3) of the brain compared to the control at P< .05. It also significantly decreased degenerating cells compared to the control (P< .05). In conclusion, onion waste quercetin, especially at 95mg/kg was found to maintain the pool of normal cells within the dentate gyrus and hippocampus of mice brain.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135236328","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}
Double skin facades (DSF) aim to save energy reducing the heat losses in buildings. They are visually appeal while allowing to use daylight efficiently. Such facade systems can reduce glare and distribute daylight evenly in the interior when compared to conventional facade systems. That is a result of cavities between two glass facades and locating sunshading elements in them, although this system provides a high level of transparency. As their primary purpose of application is to ensure thermal performance and ventilation, most studies in literature have focused on these. However, to construct and maintain a holistic point of view in building performance, researchers and professionals need to take into account the integration of daylight use and analysis in such facades. This study aims to analyse daylight performance implemented studies in relation to these systems and presents a comprehensive and recent review on integration of daylight use and analysis. Recent studies are shown in tabulated form and interpreted in detail with graphics. considering their methodologies, daylight parameters and findings. Results show that the daylight parameter is one of the most important issues that architects or designers should consider from the moment they start the design, and they should make their designs based on the optimum penetration of daylight into the building. This review can contribute to literature in calling attention to daylight studies in DSF. It provides feedback information on how recent researches and technological developments in DSF can let them benefit from daylight more efficiently. That makes more and further improvements in such facade system design. Thus, DSF helps to build an integrated building performance approach in achieving sustainability.
{"title":"Integration of Daylight Use and Analysis in Double Skin Facades: A Literature Review","authors":"Mustafa Serhan Ünlütürk, Tuğçe Kazanasmaz","doi":"10.35378/gujs.1243933","DOIUrl":"https://doi.org/10.35378/gujs.1243933","url":null,"abstract":"Double skin facades (DSF) aim to save energy reducing the heat losses in buildings. They are visually appeal while allowing to use daylight efficiently. Such facade systems can reduce glare and distribute daylight evenly in the interior when compared to conventional facade systems. That is a result of cavities between two glass facades and locating sunshading elements in them, although this system provides a high level of transparency. As their primary purpose of application is to ensure thermal performance and ventilation, most studies in literature have focused on these. However, to construct and maintain a holistic point of view in building performance, researchers and professionals need to take into account the integration of daylight use and analysis in such facades. This study aims to analyse daylight performance implemented studies in relation to these systems and presents a comprehensive and recent review on integration of daylight use and analysis. Recent studies are shown in tabulated form and interpreted in detail with graphics. considering their methodologies, daylight parameters and findings. Results show that the daylight parameter is one of the most important issues that architects or designers should consider from the moment they start the design, and they should make their designs based on the optimum penetration of daylight into the building. This review can contribute to literature in calling attention to daylight studies in DSF. It provides feedback information on how recent researches and technological developments in DSF can let them benefit from daylight more efficiently. That makes more and further improvements in such facade system design. Thus, DSF helps to build an integrated building performance approach in achieving sustainability.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139351768","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}
Peptide biomolecules have important bioactivities and hence their use in drug design and development studies has increased in recent years. Conotoxins are natural peptides that obtained from cone snail venoms and have the potential to be used for chronic pain treatment, Parkinson's disease, schizophrenia, obesity and cancer due to their effects on the nervous system. However, their use as medicines has been limited as they can be easily broken down by many proteolytic enzymes in the body. Several modification methods are used to overcome these disadvantages. Cyclization of the peptide backbone is one such method and has been used to stabilize various linear peptides. In this study, the N- and C-termini of α-conotoxin TxID with two disulfide bridges were joined using a six amino acid long GGAAGG linker peptide chain to cyclize the peptide backbone and the serum stability of the cyclized peptide was examined. The cyclic TxID peptide remained intact about 50% in human serum after 24 hours.
{"title":"Head-to-Tail Cyclization of α-Conotoxin TxID Leads to Enhanced Stability in Serum","authors":"Nurcan BİÇEN KARAKOÇ, Muharrem Akcan","doi":"10.35378/gujs.1263833","DOIUrl":"https://doi.org/10.35378/gujs.1263833","url":null,"abstract":"Peptide biomolecules have important bioactivities and hence their use in drug design and development studies has increased in recent years. Conotoxins are natural peptides that obtained from cone snail venoms and have the potential to be used for chronic pain treatment, Parkinson's disease, schizophrenia, obesity and cancer due to their effects on the nervous system. However, their use as medicines has been limited as they can be easily broken down by many proteolytic enzymes in the body. Several modification methods are used to overcome these disadvantages. Cyclization of the peptide backbone is one such method and has been used to stabilize various linear peptides. In this study, the N- and C-termini of α-conotoxin TxID with two disulfide bridges were joined using a six amino acid long GGAAGG linker peptide chain to cyclize the peptide backbone and the serum stability of the cyclized peptide was examined. The cyclic TxID peptide remained intact about 50% in human serum after 24 hours.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41385874","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}
In this paper, we present a low profile, wideband dual-polarized suspended patch antenna for LTE700/LTE850/CDMA850/GSM900 applications with high isolation. The proposed antenna element consists of two suspended patches excited orthogonally through modified cross-slot. It is theoretically and experimentally verified that this modification significantly widens −15 dB impedance bandwitdh and improves port isolation between polarizations. Experiments reveal in parallel with conducted simulations that the antenna is capable of exhibiting 37% −15 dB impedance bandwidth (688-1000 MHz) and more than 35 dB port isolation over operating frequency band. In principle planes, the antenna provides symmetric broadside radiation patterns at boresight with half-power beamwidths of 55.32º-65.61º and 61.79º-66.84º. Gain of the antenna varies within 7.3-8.4 dBi range at measured frequencies. The size of the antenna is 380 × 380 × 43.6 mm3 which makes it very suitable to integrate into commercially deployed base stations. Geometry, feeding mechanism, parametric studies and experimental results of the proposed antenna are presented throughout the paper.
本文提出了一种用于 LTE700/LTE850/CDMA850/GSM900 应用的低剖面、宽带双极化悬浮贴片天线，具有很高的隔离度。拟议的天线元件由两个悬浮贴片组成，通过改进的十字槽正交激励。经理论和实验验证，这种改进大大拓宽了 -15 dB 阻抗带宽，并提高了极化间的端口隔离度。实验与模拟同时显示，该天线能够在工作频段内显示 37% -15 dB 阻抗带宽（688-1000 MHz）和超过 35 dB 的端口隔离度。在原理平面上，该天线在内径处提供对称的宽边辐射模式，半功率波束宽度分别为 55.32º-65.61º 和 61.79º-66.84º。在测量频率下，天线的增益在 7.3-8.4 dBi 范围内变化。天线尺寸为 380 × 380 × 43.6 mm3，非常适合集成到商用基站中。本文通篇介绍了拟议天线的几何形状、馈电机制、参数研究和实验结果。
{"title":"A Low-Profile High Isolation Wideband Dual-Polarized Antenna for Sub-1 GHz Base Stations","authors":"E. A. Miran, M. Çiydem","doi":"10.35378/gujs.1279556","DOIUrl":"https://doi.org/10.35378/gujs.1279556","url":null,"abstract":"In this paper, we present a low profile, wideband dual-polarized suspended patch antenna for LTE700/LTE850/CDMA850/GSM900 applications with high isolation. The proposed antenna element consists of two suspended patches excited orthogonally through modified cross-slot. It is theoretically and experimentally verified that this modification significantly widens −15 dB impedance bandwitdh and improves port isolation between polarizations. Experiments reveal in parallel with conducted simulations that the antenna is capable of exhibiting 37% −15 dB impedance bandwidth (688-1000 MHz) and more than 35 dB port isolation over operating frequency band. In principle planes, the antenna provides symmetric broadside radiation patterns at boresight with half-power beamwidths of 55.32º-65.61º and 61.79º-66.84º. Gain of the antenna varies within 7.3-8.4 dBi range at measured frequencies. The size of the antenna is 380 × 380 × 43.6 mm3 which makes it very suitable to integrate into commercially deployed base stations. Geometry, feeding mechanism, parametric studies and experimental results of the proposed antenna are presented throughout the paper.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139355722","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}
In this study, the distribution’s reliability and hazard functions, as well as the population parameters, are estimated for the length biased weighted Lomax (LBWLo) based on progressively Type II censored samples. The maximum likelihood and Bayesian methods are implanted to get the proposed estimators. Gamma and Jeffery's priors serve as informative and non-informative priors, respectively, from which the posterior distribution of the LBWLo distribution is constructed. To obtain the Bayesian estimates, the Metropolis-Hasting (MH) algorithm is also used. We obtain asymptotic confidence intervals based on the Fisher information matrix. Using the sample produced by the MH method, we construct the intervals with the highest posterior densities. A numerical simulation research is done to evaluate the effectiveness of the approaches. Through Monte Carlo simulation, we compare the proposed estimators in terms of mean squared error. It is possible to get coverage probability and average interval lengths of 95% .The study's findings supported the idea that, in the majority of cases, Bayes estimates with an informative prior are more appropriate than other estimates.
{"title":"Classical and Bayesian Inference for the Length Biased Weighted Lomax Distribution under Progressive Censoring Scheme","authors":"Amal S. HASSAN, Samah A. ATİA, Hiba Z. MUHAMMED","doi":"10.35378/gujs.1249968","DOIUrl":"https://doi.org/10.35378/gujs.1249968","url":null,"abstract":"In this study, the distribution’s reliability and hazard functions, as well as the population parameters, are estimated for the length biased weighted Lomax (LBWLo) based on progressively Type II censored samples. The maximum likelihood and Bayesian methods are implanted to get the proposed estimators. Gamma and Jeffery's priors serve as informative and non-informative priors, respectively, from which the posterior distribution of the LBWLo distribution is constructed. To obtain the Bayesian estimates, the Metropolis-Hasting (MH) algorithm is also used. We obtain asymptotic confidence intervals based on the Fisher information matrix. Using the sample produced by the MH method, we construct the intervals with the highest posterior densities. A numerical simulation research is done to evaluate the effectiveness of the approaches. Through Monte Carlo simulation, we compare the proposed estimators in terms of mean squared error. It is possible to get coverage probability and average interval lengths of 95% .The study's findings supported the idea that, in the majority of cases, Bayes estimates with an informative prior are more appropriate than other estimates.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139356327","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}
Capacity planning should be performed to balance investment costs and benefits of investing to meet the current and future demand in intensive care units. Having a high capacity to increase patient admission will lead to unutilized capacity in some periods, thereby increasing costs. On the other hand, patient admission requests from inborn and transported patients might be rejected due to lack of equipment. It should be considered in terms of cost-effectiveness and patient health; therefore, optimal equipment capacity must be determined. In this study, the optimal capacity planning problem has been considered for the neonatal intensive care unit of a hospital adopting the simulation-optimization approach. A discrete event simulation model is proposed for a neonatal intensive care unit in Adana, Turkey. Then, the optimization model identified the optimal numbers of incubators, ventilators, and nitric oxide devices to maximize equipment efficiency and minimize total inborn patient rejection and transport ratios. Three different resource allocations are presented, and the best is obtained from these three objectives as 72 incubators, 35 ventilators, and three nitric oxide devices. The application results obtained have revealed that the rejection and transport rate, which is found to be 1.12% in the current situation, can be reduced to 0.2% with different numbers of equipment and that equipment efficiency can be achieved with optimal numbers of equipment. The results of the study can help the decision-makers when minimum transport and rejection ratios are critical which almost intensive care units are required. Furthermore, the proposed simulation-optimization model can be adapted to different neonatal intensive care units having the same characteristics.
{"title":"Optimal Equipment Capacity Planning in the Neonatal Intensive Care Unit with Simulation-Optimization Approach","authors":"Mufide Narli, Yusuf Kuvvetli̇, Ali Kokangül","doi":"10.35378/gujs.1247829","DOIUrl":"https://doi.org/10.35378/gujs.1247829","url":null,"abstract":"Capacity planning should be performed to balance investment costs and benefits of investing to meet the current and future demand in intensive care units. Having a high capacity to increase patient admission will lead to unutilized capacity in some periods, thereby increasing costs. On the other hand, patient admission requests from inborn and transported patients might be rejected due to lack of equipment. It should be considered in terms of cost-effectiveness and patient health; therefore, optimal equipment capacity must be determined. In this study, the optimal capacity planning problem has been considered for the neonatal intensive care unit of a hospital adopting the simulation-optimization approach. A discrete event simulation model is proposed for a neonatal intensive care unit in Adana, Turkey. Then, the optimization model identified the optimal numbers of incubators, ventilators, and nitric oxide devices to maximize equipment efficiency and minimize total inborn patient rejection and transport ratios. Three different resource allocations are presented, and the best is obtained from these three objectives as 72 incubators, 35 ventilators, and three nitric oxide devices. The application results obtained have revealed that the rejection and transport rate, which is found to be 1.12% in the current situation, can be reduced to 0.2% with different numbers of equipment and that equipment efficiency can be achieved with optimal numbers of equipment. The results of the study can help the decision-makers when minimum transport and rejection ratios are critical which almost intensive care units are required. Furthermore, the proposed simulation-optimization model can be adapted to different neonatal intensive care units having the same characteristics.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139358669","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}
Dila Çi̇ğdem, Bilge Toprak Karakaya, Duru Deği̇mli̇, Meltem GÖNÜLOL ÇELİKOĞLU, Yavuz Öztürk
In this study, a novel magnetic system that allows observing quantized conductance for undergraduate and graduate laboratories is presented. Bending of a magnetic cylindrical beam, like a cantilever, was controlled by an electromagnet to provide contact between needle type electrode and a plane of conductor. It is shown that by using the beam bending, it is possible to displace an object on the beam in nanometer and micrometer scale. The measured quantized conductance results prove that the designed system can be used for demonstration of quantized conductance.
{"title":"OBSERVING CONDUCTANCE QUANTIZATION by a NOVEL MAGNETIC CONTROL SYSTEM","authors":"Dila Çi̇ğdem, Bilge Toprak Karakaya, Duru Deği̇mli̇, Meltem GÖNÜLOL ÇELİKOĞLU, Yavuz Öztürk","doi":"10.35378/gujs.1222023","DOIUrl":"https://doi.org/10.35378/gujs.1222023","url":null,"abstract":"In this study, a novel magnetic system that allows observing quantized conductance for undergraduate and graduate laboratories is presented. Bending of a magnetic cylindrical beam, like a cantilever, was controlled by an electromagnet to provide contact between needle type electrode and a plane of conductor. It is shown that by using the beam bending, it is possible to displace an object on the beam in nanometer and micrometer scale. The measured quantized conductance results prove that the designed system can be used for demonstration of quantized conductance.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46908279","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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