Discrimination of crown closure of forest ecosystems using different remotely sensed data: a case study of Kızılcasu planning unit

Alkan Gunlu,Sedat Kele¸,Emin Zeki Ba¸sken,Ali Ihsan Kadıogulları 한국산림과학회 2016 Forest Science And Technology Vol.12 No.1

The objective of this study was to estimate crown closure using different satellite images, Landsat TM and QuickBird. As reference data, forest cover type map were used in the study, and two different methods were used to determine the crown closure. First, to classify crown closures from satellite images, a supervised classification method was used. Second, the linear mixture modeling (LMM) fuzzy classification method was used to determine the stand crown closure. Landsat TM and QuickBird data were used in this frame. The training dataset was derived from a fine spatial resolution land cover classification of QuickBird imagery. This classification was combined to estimate the percentage crown closure in Landsat TM spatial resolution. The research also focused on classifying and mapping the crown closure classes with the spatial analysis functions of geographical information systems (GIS). The results showed that the QuickBird image had the highest classification accuracies compared to the spatial analyses results of Landsat TM and fuzzy classification.

STRUCTURE OF APÉRY-LIKE SERIES AND MONOTONICITY PROPERTIES FOR BINOMIAL SUMS

Alkan, Emre Korean Mathematical Society 2017 대한수학회보 Vol.54 No.1

A family of $Ap{\acute{e}}ry$-like series involving reciprocals of central binomial coefficients is studied and it is shown that they represent transcendental numbers. The structure of such series is further examined in terms of finite combinations of logarithms and arctangents with arguments and coefficients belonging to a suitable algebraic extension of rationals. Monotonicity of certain quotients of weighted binomial sums which arise in the study of competitive cheap talk models is established with the help of a continuous extension of the discrete model at hand. The monotonic behavior of such quotients turns out to have important applications in game theory.

Critical buckling load optimization of the axially graded layered uniform columns

Alkan, Veysel Techno-Press 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.54 No.4

This study presents critical buckling load optimization of the axially graded layered uniform columns. In the first place, characteristic equations for the critical buckling loads for all boundary conditions are obtained using the transfer matrix method. Then, for each case, square of this equation is taken as a fitness function together with constraints. Due to explicitly unavailable objective function for the critical buckling loads as a function of segment length and volume fraction of the materials, especially for the column structures with higher segment numbers, initially, prescribed value is assumed for it and then the design variables satisfying constraints are searched using Differential Evolution (DE) optimization method coupled with eigen-value routine. For constraint handling, Exterior Penalty Function formulation is adapted to the optimization cycle. Different boundary conditions are considered. The results reveal that maximum increments in the critical buckling loads are attained about 20% for cantilevered and pinned-pinned end conditions and 18% for clamped-clamped case. Finally, the strongest column structure configurations will be determined. The scientific and statistical results confirmed efficiency, reliability and robustness of the Differential Evolution optimization method and it can be used in the similar problems which especially include transcendental functions.

Critical buckling load optimization of the axially graded layered uniform columns

Veysel Alkan 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.54 No.4

This study presents critical buckling load optimization of the axially graded layered uniform columns. In the first place, characteristic equations for the critical buckling loads for all boundary conditions are obtained using the transfer matrix method. Then, for each case, square of this equation is taken as a fitness function together with constraints. Due to explicitly unavailable objective function for the critical buckling loads as a function of segment length and volume fraction of the materials, especially for the column structures with higher segment numbers, initially, prescribed value is assumed for it and then the design variables satisfying constraints are searched using Differential Evolution (DE) optimization method coupled with eigen-value routine. For constraint handling, Exterior Penalty Function formulation is adapted to the optimization cycle. Different boundary conditions are considered. The results reveal that maximum increments in the critical buckling loads are attained about 20% for cantilevered and pinned-pinned end conditions and 18% for clamped-clamped case. Finally, the strongest column structure configurations will be determined. The scientific and statistical results confirmed efficiency, reliability and robustness of the Differential Evolution optimization method and it can be used in the similar problems which especially include transcendental functions.

On primary decompositions and radicals of submodules

M. Alkan,B. Saraç 장전수학회 2007 Proceedings of the Jangjeon mathematical society Vol.10 No.1

In this paper, we give some characterizations for prime and primary submodules of a …nitely generated free modules over PID’s and determine the height of prime submodules. We also char- acterize the minimal primary decompositions and radicals of submodules of any …nitely generated free module over a PID.

FINITE ELEMENT MODELING OF STATIC TIRE ENVELOPING CHARACTERISTICS

V. ALKAN,S. M. KARAMIHAS,G. ANLAS 한국자동차공학회 2011 International journal of automotive technology Vol.12 No.4

To investigate static tire enveloping characteristics, a three dimensional (3-D) finite element model is proposed. The vertical stiffness of the tire is studied on a flat surface with and without cleat. Tire rubber materials and cord layers are represented independently using “rebar” elements available in MSC Marc Mentat. Comparisons of numerical and experimental results are given to show the validity of the proposed model. It is shown that after a certain displacement, the results of the proposed model agree well with experimental results. In addition, the model results show that regardless of the type of the cleat placed under the rim center (hub center), all vertical force curves intersect after a certain displacement, which indicates typical static enveloping characteristics. Moreover, another typical characteristic of the radial tires that is unlike those of bias-ply constructions confirms that the contact patch does not expand laterally after a level vertical load is applied to the tire, which is directly related to fuel consumption and tire tread life.

Structure of Apery-like series and monotonicity properties for binomial sums

Emre Alkan 대한수학회 2017 대한수학회보 Vol.54 No.1

A family of Ap\'{e}ry-like series involving reciprocals of central binomial coefficients is studied and it is shown that they represent transcendental numbers. The structure of such series is further examined in terms of finite combinations of logarithms and arctangents with arguments and coefficients belonging to a suitable algebraic extension of rationals. Monotonicity of certain quotients of weighted binomial sums which arise in the study of competitive cheap talk models is established with the help of a continuous extension of the discrete model at hand. The monotonic behavior of such quotients turns out to have important applications in game theory.

Superoxide Anion Production by the Spermatozoa of Men with Varicocele: Relationship with Varicocele Grade and Semen Parameters

İlter Alkan,Meral Yüksel,Halil Lütfi Canat,Hasan Anıl Atalay,Osman Can,Hakan Özveri,Mehmet Murad Başar 대한남성과학회 2018 The World Journal of Men's Health Vol.36 No.3

Purpose: To investigate the pathophysiological role of superoxide anion and total reactive oxygen species (ROS) production by the spermatozoa of men with varicocele and its relationship with varicocele grade and semen parameters. Materials and Methods: This prospective study included 34 men with grade II–III varicocele, regardless of their fertility status. The control group consisted of 13 healthy men. Semen characteristics were examined according to the 2010 World Health Organization criteria. The swim-up method was used for sperm preparation. Total ROS and superoxide anion production was assayed by luminol- and lucigenin-dependent chemiluminescence (CL), respectively. Results: The men with varicocele had significantly higher total ROS and superoxide anion levels than the healthy control subjects (2.9±0.4 relative light unit (RLU) vs. 2.4±0.1 RLU, p=0.001 for luminol-dependent CL and 2.8±0.4 RLU vs. 2.3±0.2 RLU, p=0.002 for lucigenin-dependent CL). Cases of grade III varicocele had significantly higher superoxide anion and total ROS levels than grade II cases and control subjects (p<0.001). Superoxide anion and total ROS levels were negatively correlated with all semen parameters. Conclusions: The superoxide anion levels produced by spermatozoa were significantly higher in varicocele patients than in control subjects. ROS production was related to increased varicocele grade, impaired semen concentration, and abnormal morphology in men with varicocele. Our findings suggest that superoxide anion overproduction may be an important step in the cascade of ROS-related damage to spermatozoa, resulting in impaired semen parameters in patients with varicocele.

Automatic Diagnosis of Attention Deficit Hyperactivity Disorder with Continuous Wavelet Transform and Convolutional Neural Network

Sinan Altun(Sinan Altun ),Ahmet Alkan(Ahmet Alkan ),Hatice Altun(Hatice Altun ) 대한정신약물학회 2022 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.20 No.4

Objective: The attention deficit hyperactivity disorder has a negative impact on the child’s educational life and relationships with the social environment during childhood and adolescence. The connection between temperament traits and The attention deficit hyperactivity disorder has been proven by various studies. As far as we know, there is no machine learning study to diagnose. The attention deficit hyperactivity disorder in a dataset created using temperament characteristics. Methods: Machine learning-based semi-automatic/fully automatic expert decision support systems are frequently used for the diagnosis of various diseases. In this study, it was aimed to reveal the success of a semi-automatic expert decision support system in the diagnosis of attention deficit hyperactivity disorder by using temperament characteristics. The high classification success achieved is a resource for a potential diagnosis of attention deficit hyperactivity disorder expert decision support system. In this respect, this study includes original qualities and innovations. Results: Many different deep learning methods were used in the research. Deep learning methods are models that achieve high success by using a large number of images in various image processing competitions. The images of the signals in the data set were first obtained by Continuous Wavelet Transform. The highest classification success in our data set was obtained with the Squeeze Net model with 88.33%. Conclusion: The model we propose shows that an automatic system based on artificial intelligence can be created, as well as revealing the relationship between temperament characteristics in the diagnosis of attention deficit hyperactivity in the data set we created.

Age of Information in Multihop Multicast Networks

Baturalp Buyukates,Alkan Soysal,Sennur Ulukus 한국통신학회 2019 Journal of communications and networks Vol.21 No.3

We consider the age of information in a multihop multicastnetwork where there is a single source node sending timesensitiveupdates to nL end nodes, and L denotes the number ofhops. In the first hop, the source node sends updates to n first-hopreceiver nodes, and in the second hop each first-hop receiver noderelays the update packets that it has received to n further usersthat are connected to it. This network architecture continues infurther hops such that each receiver node in hop ` is connected ton further receiver nodes in hop ` + 1. We study the age of informationexperienced by the end nodes, and in particular, its scalingas a function of n. We show that, using an earliest k transmissionscheme in each hop, the age of information at the end nodes can bemade a constant independent of n. In particular, the source nodetransmits each update packet to the earliest k1 of the n first-hopnodes, and each first-hop node that receives the update relays it tothe earliest k2 out of n second-hop nodes that are connected to itand so on. We determine the optimum k` stopping value for eachhop ` for arbitrary shifted exponential link delays.