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Spatial estimation of wind speed:a new integrative model using inverse distance weighting and power law

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International Journal of Digital Earth 2016年第8期9卷 733-747页

作者： Emre Ozelkan Gang Chen burak berk ustundag Agricultural&Environmental Informatics Research and Application Centre Istanbul Technical UniversityIstanbulTurkey Department of Geography and Earth Sciences University of North Carolina at CharlotteCharlotteNCUSA Laboratory for Remote Sensing and Environmental Change(LRSEC) University of North Carolina at CharlotteCharlotteNCUSA

Spatial interpolation(SI)is currently one of the most common ways to estimate wind speed(Ws).However,classic SI models either ignore the complex geography[*** distance weighting(IDW)],or demand high computational resources(***).This study aimed to develop a simple yet effective SI model for estimating Ws in Eastern Thrace of *** new method,named MIDW(Ws),is a modified IDW through the integration of IDW with wind profile model,power law(PL),representing the influence of land cover and topography on *** features and elevation data of PL were obtained using normalized difference vegetation index(NDVI)and digital elevation model(DEM),*** showed superior and comparable performance of MIDW(Ws)to standard IDW and ordinary kriging(OK)across all months of *** to ordinary cokriging(OCK)using DEM as covariate,MIDW(Ws)generated better results in the arid–semiarid seasons(around summer).Local complex atmospheric conditions during rainy seasons(around winter)may have affected the performance of incorporating PL with MIDW(Ws).Generally,the proposed MIDW(Ws)is simpler and easier to implement compared to *** landscape-scale projects,its high computational efficiency and relatively robust performance show potential to deal with large volumes of datasets.

关键词： Wind speed power law NDVI spatial interpolation modified inverse distance weighting

An adaptive Mealy machine model for monitoring crop status

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Journal of Integrative Agriculture 2017年第2期16卷 252-265页

作者： berk ustundag Agricultural and Environmental Informatics Application & Research Center/Faculty of Informatics and Computer Engineering Istanbul Technical University Istanbul 34469 Turkey

Variation in phenological stage is the major nonlinearity in monitoring, modeling and various estimations of agricultural systems. Indices are used as a common means of evaluating agricultural monitoring data from remote sensing and terrestrial observation systems, and many of these indices have linear characteristics. The analysis of and relationships between indices are dependent on the type of plant, but they are also highly variable with respect to its phenologicat stage. For this reason, variations in the phenologica! stage affect the performance of spatiotemporal crop status monitoring. We hereby propose an adaptive event-triggered model for monitoring crop status based on remote sensing data and terrestrial observations. In the proposed model, the estimation of phenological stage is a part of predicting crop status, and spatially distributed remote sensing parameters and temporal terrestrial monitoring data are used together as inputs in a state space system model. The temporal data are segmented with respect to the phenological stage-oriented timing of the spatial data, so instead of a generalized discrete state space model, we used logical states combined with analog inputs and adaptive trigger functions, as in the case of a Mealy machine model. This provides the necessary nonlinearity for the state transi- tions. The results showed that observation parameters have considerably greater significance in crop status monitoring with respect to conventional agricultural data fusion techniques.

关键词： plant phenology monitoring yield prediction finite automata Mealy machine remote sensing

Internal Validity Index for Fuzzy Clustering Based on Relative Uncertainty

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Computers, Materials & Continua 2022年第8期72卷 2909-2926页

作者： Refik Tanju Sirmen burak berk Üstündag Graduate School of Science Engineering&Technology Istanbul Technical UniversityIstanbul34469Turkey Faculty of Computer&Informatics Istanbul Technical UniversityIstanbul34469Turkey

Unsupervised clustering and clustering validity are used as essential instruments of data *** clustering being realized under uncertainty,validity indices do not deliver any quantitative evaluation of the uncertainties in the suggested ***,validity measures may be biased towards the underlying clustering ***,neglecting a confidence requirement may result in *** the absence of an error estimate or a confidence parameter,probable clustering errors are forwarded to the later stages of the ***,having an uncertainty margin of the projected labeling can be very fruitful for many applications such as machine ***,the validity issue was approached through estimation of the uncertainty and a novel low complexity index proposed for fuzzy *** involves only uni-dimensional membership weights,regardless of the data dimension,stipulates no specific distribution,and is independent of the underlying similarity *** tests and comparisons returned that it can reliably estimate the optimum number of partitions under different data distributions,besides behaving more robust to over ***,in the comparative correlation analysis between true clustering error rates and some known internal validity indices,the suggested index exhibited the highest strong *** relationship has been also proven stable through additional statistical acceptance *** the provided relative uncertainty measure can be used as a probable error estimate in the clustering as ***,it is the only method known that can exclusively identify data points in dubiety and is adjustable according to the required confidence level.

关键词： Machine learning data science clustering validity fuzzy clustering uncertainty intelligent systems data analytics

Remote sensing for agricultural applications

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Journal of Integrative Agriculture 2017年第2期16卷 239-241页

作者： zhengwei yang wu wen-bin liping di berk ustundag research and development division usda national agricultural statistics service VA22030USA institute of agricultural resources and regional planning chinese academy of agricultural sciences Beijing 1 00081PR.China center for spatial information science and systems george mason university VA 22030USA agricultural and environmental informatics application&research center/faculty of informatics and computer engineering istanbul technical university Istanbul 34469Turkey

Agricultural geospatial information is critical for agricultural policy formulation and decision making, land use monitoring, agricultural sustainability, crop acreage and yield estimation, disaster assessment, bioenergy crop inventory, food security policy, environmental assessment, carbon accounting, and other research topics that are of vital importance to agricul- ture and economy. Remote sensing technology enables us to collect, process, and analyze remotely sensed data and to retrieve, synthesize, visualize valuable geospatial information for agriculture uses. Specifically, remote sensing technology empowers capability for large scale field level or regional assessment and monitoring of crop land cover,

关键词： Remote sensing for agricultural applications MODIS RUSLE NDVI data

Effect of gamification applications on success of dentistry students

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World Journal of Methodology 2025年第1期15卷 80-87页

作者： Hatice Ahsen Deniz Elif Polat Balkan burak İncebeyaz Kıvanç Kamburoğlu Department of Dentomaxillofacial Radiology Ankara University Faculty of DentistryAnkara 06500Türkiye

BACKGROUND Gamification,the use of game materials in education,has been used in several scientific fields,and studies have demonstrated its effectiveness in student *** To evaluate whether the success of 4th-and 5th-grade dentistry students increases when using the gamification applications Kahoot!and *** An experimental design was used to measure the effect of gamification applications on students who were taught using the traditional *** this purpose,Mentimeter and Kahoot!applications were used in this experimental *** groups of 4th-and 5th-grade students were formed:Mentimeter,Kahoot!,and control *** effect of gamification applications on achievement was evaluated by administering a post-test to these groups after the instructional ***-way analysis of variance and t-tests were used for statistical *** A total of 35.5%of the students were in the Mentimeter group,29.8%in the Kahoot!group,and 34.6%in the control *** the total number of students,54.8%were female and 45.2%were male,while 52.2%were 5th-grade students and 47.8%were 4th-grade *** overall grade point average was found to be 66.65(range,24-100).There was a statistically significant difference in average success scores between students of different groups(P=0.003<0.05)and grades(P=0.036<0.05).The average success score was the highest in the Mentimeter group(71.64)and the lowest in the Kahoot!group(62.15).In the control group,this score was *** average success score was higher for students in the 5thgrade(68.16)and for female students(68.84).CONCLUSION Gamification has a great potential in the education of dentomaxillofacial radiology *** outperformed both the Kahoot!and the traditional method in terms of average student success rates.

关键词： Gamification Mentimeter Kahoot! Education Dentistry

Fused and Modified Evolutionary Optimization of Multiple Intelligent Systems Using ANN, SVM Approaches

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Computers, Materials & Continua 2021年第2期66卷 1479-1496页

作者： Jalal Sadoon Hameed Al-bayati burak berk Üstündağ Jalal Sadoon Hameed Al-bayati Istanbul Technical UniversityIstanbul34469Turkey burak berkÜstündağ Istanbul Technical UniversityIstanbul34469Turkey

The Fused Modified Grasshopper Optimization Algorithm has been proposed,which selects the most specific feature sets from images of the disease of plant *** Proposed algorithm ensures the detection of diseases during the early stages of the diagnosis of leaf disease by farmers and,finally,the crop needed to be controlled by farmers to ensure the survival and protection of *** this study,a novel approach has been suggested based on the standard optimization algorithm for grasshopper and the selection of *** conditions in plants are a major factor in reducing crop yield and *** delay or errors in the diagnosis of the disease can lead to delays in the management of plant disease spreading and damage and related material *** new heuristic optimization of swarm intelligence,Grasshopper Optimization Algorithm was inspired by grasshopper movements for their feeding *** simulates the attitude and social interaction of grasshopper swarm in terms of gravity and wind *** the decision on features extracted by an accelerated feature selection algorithm,popular approaches such as ANN and SVM classifiers had been *** the evaluation of the proposed model,different data sets of plant leaves were *** proposed model was successful in the diagnosis of the diseases of leaves the plant with an accuracy of 99.41 percent(average).The proposed biologically inspired model was sufficiently satisfied,and the best or most desirable characteristics were ***,the results of the research for these data sets were estimated by the proposed Fused Modified Grasshopper Optimization Algorithm(FMGOA).The results of that experiment were demonstrated to allow classification models to reduce input features and thus to increase the precision with the presented Modified Grasshopper Optimization *** and analysis were performed to prove the model validity through model parameters such as precision,recall,f-

关键词： Fusion machine learning plant leaves diseases feature selection fused modified grasshopper algorithm

Comparison of a commercial powder and a powder produced from Ti–6Al–4V chips and their effects on compacts sintered by the sinter-HIP method

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International Journal of Minerals,Metallurgy and Materials 2019年第7期26卷 878-888页

作者： Mustafa ustundag Remzi Varol Department of Mechanical Engineering Suleyman Demirel University

The present paper is related to the conversion of Ti–6Al–4V chips into powder and investigates the usability of the produced powder in powder metallurgy applications. In this regard, a disc-milling process was applied to Ti–6Al–4V chips and the obtained powder was subsequently compacted. The compacted samples were sintered by the sinter hot isostatic pressing (sinter-HIP) method at 1200°C under high vacuum, their mechanical properties and microstructure were investigated and compared with those of commercial powder compacts subjected to the same preparation processes. The results showed that the produced powder exhibits greater flowability and higher apparent density than the commercial powder. However, the sintered products prepared from the commercial powder exhibited a higher relative density, lower porosity, and, as a result, greater flexural strength compared with the sintered compacts prepared from the produced powder. In addition, transgranular fracture was greater in the sintered products of the commercial powder. The microstructural studies revealed that the sintered products made from both the commercial and the produced powders consisted of α- and β-phase but contained more α-phase. All of the examined properties were found to be substantially affected by the particle size of the powders.

关键词： Ti-6Al-4V chips sinter hot isostatic pressing flexural strength porosity

Cholangiocarcinoma:A compact review of the literature

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World Journal of Gastroenterology 2008年第42期14卷 6458-6466页

作者： Yucel ustundag Yusuf Bayraktar Department of Internal Medicine Gastro-enterology Clinic School of Medicine Karaelmas University Department of Internal Medicine Gastro-enterology Clinic School of Medicine Hacettepe University

Cholangiocarcinoma(CC) is a devastating cancer aris-ing from biliary ***,the incidence of this disease is increasing in Western *** tumors progress insidiously,and liver failure,biliary sepsis,malnutrition and cancer cachexia are general modes of death associated with this *** date,no established therapy for advanced dis-ease has been established or ***,our knowledge in tumor biology is increasing dramatically and new drugs are under investigation for treatment of this notorious *** clinical practice,there are better diagnostic tools in use to facilitate an earlier diagnosis of CC,at least in those patients with known risk *** is resectable for cure in only a small percentage of *** staging for vas-cular and biliary extension of CC is very important in this *** and recently endosonography seem to protect against unnecessary laparotomies in these *** the last 15 years,aggressive surgical approaches,including combined liver resec-tions and vascular reconstructive surgical expertise,have improved survival in patients with *** is contraindicated in CC cases having primary sclerosing cholangitis(PSC).Although CC was previously consid-ered a contraindication to liver transplantation,new cautious protocols,including neo-adjuvant chemora-diation therapies and staging procedures before the transplantation,have made it possible to achieve long-term survival after liver transplantation in this *** ablative therapies with photodynamic therapy,intraductal high-intensity ultrasonography and chemo-therapy-impregnated plastic biliary endoprosthesis are important steps in the palliative management of extra-hepatic *** and chemo-embolization methods are also applicable for intra-hepatic CCs as palliative modes of *** need more prospec-tive randomized controlled trials to evaluate the role of the new emerging therapies for CC patients.

关键词： Cholangiocarcinoma Primary sclerosing cholangitis Radiofrequency ablation Chemoembolization

Pancreatic hyperechogenicity on endoscopic ultrasound examination

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World Journal of Gastroenterology 2011年第15期17卷 2061-2062页

作者： Yucel ustundag Guray Ceylan Koray Hekimoglu Zonguldak Karaelmas University School of Medicine Department of Internal Medicine Gastroenterology Clinics Zonguldak 67100 Turkey Baskent University School of Medicine Department of Radiology Ankara 06100 Turkey

There is an ongoing discussion on how to diagnose a hyperechogenic pancreas and what is the clinical significance of diffusely hyperechogenic pancreas. Computerized tomography and magnetic resonance imaging are the more appropriate methods to diagnose pancreatic hyperechogenicity when compared with transcutaneous or endoscopic ultrasound examination. More importantly, pancreatic hyperechogenicity may not be a certain indicator of pancreatic fat infiltration. Even if it is true, we do not know the clinical significances of pancreatic fat accumulation. Some suggested that excess fat in the pancreas is associated with chronic pancreatitis. However, several histological studies on human alcoholic chronic pancreatitis did not prove the presence of fatty pancreas in such cases. Thus, except for aging, it is very rare to have truly steatotic pancreas in the absence of certain human diseases.

关键词： Hyperechogenic pancreas Fatty pancreas Endoscopic ultrasound Aging Chronic pancreatitis