Yazar "Altin, Mustafa" seçeneğine göre listele
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Öğe Channel-boosted multi-scale R-CNN for accurate and real-time ship and land detection in complex SAR scenes(Elsevier Sci Ltd, 2026) Hanbay, Kazim; Ozcelik, Salih Taha Alperen; Altin, Mustafa; Uzen, HuseyinAccurate ship detection in Synthetic Aperture Radar (SAR) imagery is crucial for maritime surveillance but remains challenging due to small target sizes, speckle noise, and complex sea-surface backgrounds. While most existing methods focus exclusively on identifying ships, our approach also achieves reliable detection of land areas, providing an additional contribution to the literature. This study introduces CBM-RCNN (Channel-Boosted Multi-Scale R-CNN), a novel deep learning architecture that integrates Convolutional Block Attention Modules (CBAM) and a Bidirectional Feature Pyramid Network (BiFPN) on a ResNet50 backbone. CBAM enhances both spatial and channel-level feature representation, enabling reliable detection of small vessels, while BiFPN fuses multi-scale features bidirectionally, improving accuracy across vessels of different sizes and positions. CBM-RCNN was evaluated against standard Faster R-CNN and YOLOv8 models across diverse maritime scenes, including simple, densely populated, and visually complex scenarios. The model demonstrated superior detection accuracy, balanced class-specific performance, and strong generalization. It effectively resolves overlapping vessels, distinguishes ships from coastal structures, and maintains robustness under challenging SAR-specific noise conditions. Importantly, it achieves inference speeds suitable for near-real-time applications, highlighting practical applicability. By combining attention-driven refinement with multi-scale feature aggregation, CBM-RCNN addresses limitations of prior methods, particularly in small object recognition, complex scene generalization, and simultaneous land detection. This architecture provides a robust framework for automated maritime monitoring and offers a foundation for future improvements in large-scale SAR-based ship detection and environmental surveillance.Öğe HYPERSURFACE FAMILIES WITH SMARANDACHE CURVES IN GALILEAN 4-SPACE(Ankara Univ, Fac Sci, 2021) Altin, Mustafa; Kazan, Ahmet; Karadag, H. BayramIn this paper, we study the hypersurface families with Smarandache curves in 4-dimensional Galilean space G(4) and give the conditions for different Smarandache curves to be parameter and the curve which generates the Smarandache curves is geodesic on a hypersurface in G(4): Also, we investigate three types of marching-scale functions for one of these hypersurfaces and construct an example for it.Öğe Monge Hypersurfaces in Euclidean 4-Space with Density(Gazi Univ, 2020) Altin, Mustafa; Kazan, Ahmet; Karadag, H. BayramIn the present study, firstly we give the mean and Gaussian curvatures of a Monge hypersurface in 4-dimensional Euclidean space. After this, we study on Monge hypersurfaces in E-4 with different densities. In this context, we obtain the weighted minimal and weighted flat Monge hypersurfaces in E-4 with densities e(alpha x+beta y+yz+mu r)(linear density) and e(alpha x2+beta y2+yz2+mu t2) with the aid of different choices of constants alpha,beta,gamma and mu, where alpha,beta,gamma and mu are not all zero constants.Öğe ON CERTAIN SPACE CURVES DUE TO PARALLEL TRANSPORT FRAME IN En(Univ Nis, 2025) Singh, Charan; Kazan, Ahmet; Altin, Mustafa; Kazan, Sema; Jamali, MohammedIn this paper, we study k-type (k is an element of {0, 1, 2, ...., n-1}) slant helices due to non-zero parallel transport frame in E-n. We give some characterizations for 0-type, 1-type,..., and in general (n-1)-type slant helix due to parallel transport frame in terms of parallel transport curvatures in E-n and with the aid of these characterizations we give an important general theorem which gives the necessary and sufficient condition for any space curve to be k-type slant helices due to parallel transport frame in E-n. We also obtain the characterizations of the curves whose position vectors belong to the normal, rectifying and osculating spaces (called normal, rectifying and osculating curves, respectively) due to parallel transport frame in E-n.Öğe ON THE BEHAVIOUR OF TOTAL UMBILICAL FIBERS UNDER QUARTER-SYMMETRIC NON-METRIC CONNECTIONS IN RIEMANNIAN SUBMERSIONS(Editura Bibliotheca-Bibliotheca Publ House, 2025) Karatas, Esra; Zeren, Semra; Altin, MustafaIn this study, we investigate the geometric properties of Riemannian submersions endowed with quarter-symmetric non-metric connections. We focus specifically on the M-projective curvature tensor and the conformal curvature tensor, providing an analysis of the behaviour of these tensors. We emphasize how these curvature tensors interact with totally umbilical fibers in the setting of Riemannian submersions. We explicitly compute the relevant curvature tensors and examine how the totally umbilical condition influences their relations. This clarifies the connections among the tensors and shows how they affect the geometric structure of the submersions.Öğe RIEMANNIAN SUBMERSIONS ENDOWED WITH A NEW TYPE OF SEMI-SYMMETRIC NON-METRIC CONNECTION(Vinca Inst Nuclear Sci, 2023) Karatas, Esra; Zeren, Semra; Altin, MustafaIn this paper we study relations for the covariant derivative of O'Neill's tensor fields, Riemannian curvature, Ricci curvature and scalar curvature of the Riemannian submersion from a Riemannian manifold with respect to a new type of semi-symmetric non-metric connection to a Riemannian manifold, respectively, and demonstrate the relationship between them.Öğe ROTATIONAL SURFACES GENERATED BY PLANAR CURVES IN E3 WITH DENSITY(Etamaths Publ, 2019) Altin, Mustafa; Kazan, Ahmet; Karadag, H. BayramIn this paper, we obtain the parametric expressions of curves which have zero weighted curvature in a plane with density e(ax+by) and create the Smarandache curves of the obtaining curves. Also, we construct the rotational surfaces which are generated by planar curves with vanishing weighted curvature and give some characterizations for them.Öğe Ruled and Rotational Surfaces Generated by Non-Null Curves with Zero Weighted Curvature in (L3, ax2(Int Electronic Journal Geometry, 2020) Altin, Mustafa; Kazan, Ahmet; Karada, H. BayramIn this study, firstly we give the weighted curvatures of non-null planar curves in Lorentz-Minkowski space with density eax(2)+by(2) and obtain the planar curves whose weighted curvatures vanish in this space under the condition that the constants a and b are not zero at the same time. After giving the Frenet vectors of the non-null planar curves with zero weighted curvature in Lorentz-Minkowski space with density eax(2), we create the Smarandache curves of them. With the aid of these curves and their Smarandache curves, we get the ruled surfaces whose base curves are non-null curves of which vanishing weighted curvature and ruling curves are Smarandache curves of them. Followingly, we give some characterizations for these ruled surfaces by obtaining the mean and Gaussian curvatures, distribution parameters and striction curves of them. Also, rotational surfaces which are generated by non-null planar curves with zero weighted curvatures in Lorentz-Minkowski space E-1(3) with density eax(2) +by(2) are studied under the condition that the constants a and b are not zero at the same time. We draw the graphics of the obtained surfaces.Öğe RULED SURFACES IN E3 WITH DENSITY(Honam Mathematical Soc, 2019) Altin, Mustafa; Kazan, Ahmet; Karadag, H. BayramIn the present paper, we study curves in E-3 with density e(,)(ax2 + by2) where a, b is an element of R not all zero constants and give the parametric expressions of the curves with vanishing weighted curvature. Also, we create ruled surfaces whose base curves are the curve with vanishing weighted curvature and the ruling curves are Smarandache curves of this curve. Then, we give some characterizations about these ruled surfaces by obtaining the mean curvatures, Gaussian curvatures, distribution parameters and striction curves of them.
