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YTU
İstanbul, Turkey

Bakirman T.,YTU
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives | Year: 2012

In this paper, it is aimed to create a visual tour based on panoramic images for Civil Engineering Faculty in Yildiz Technical University. For this purpose, panoramic images should be obtained. Thus, photos taken with a tripod to have the same angle of view in every photo and panoramic images were created with stitching photos. Two different cameras with different focal length were used. With the panoramic images, visual tour with navigation tools created. Source


Kucuk I.,YTU | Kucuk I.,American University of Sharjah | Yildirim K.,Mus Alparslan University | Adali S.,University of KwaZulu - Natal
Computers and Mathematics with Applications | Year: 2015

Active vibration control problem for a rectangular plate subject to moment boundary conditions and forcing function is solved by means of a maximum principle. The control is exercised by a patch actuator and the solution is formulated using an adjoint variable leading to a coupled boundary-initial-terminal value problem. The application of the maximum principle yields the optimal control expression as well as the explicit solution for a simply supported plate. The objective functional to be minimized is defined as a quadratic functional of displacement and velocity and also includes a penalty in terms of control voltage applied to the piezoelectric patch actuator. The penalty term limits the amount of control energy spent during the control process. Numerical results are presented to assess the effect of the optimal control algorithm. © 2014 Elsevier Ltd. All rights reserved. Source


Sahin I.,General Command of Mapping | Alkis Z.,YTU
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives | Year: 2013

Increase in the number of satellites and the utilization of digital cameras in the aerial photography has spread the use of satellite image and oriented aerial photograph as real or near-real time resolution, accessible, cost effective spatial data. Co-registered images or aerial photos corrected for the height variations and orthogonality (scale) have become an essential input for geographical information systems and spatial decision making due to their integration with the other spatial data. Beyond that, images and photographs compose infrastructure for the other information in usage of spatial data with the help of the access and query facility web providing. Although the issue of the aerial photo ortho-rectification has been solved long ago, the problems related with the storage of huge amount of photos and images, their management, processes, and user accesses have been raised. These subjects concern the multitudinous private and governmental institutes. Some governmental organizations and private companies have gained the technical ability to perform these works in recent times. This situation has lead to significant increase in the amount of aerial photograph taking and processing in one year for whole country. General Command of Mapping has been using digital aerial camera since 2008 for the photograph taking. The total area covered by the satellite images, purchased for different purposes, and the aerial photographs, taken for some revision purposes or demands of governmental and private institutes, has reached up to 200.000 km2. It is considered that, colored and high resolution orthophotos of the whole country can be achieved within four years; provided that the annual production would continue similarly without any increase in amount. From the numbers given above, it is clear and inevitable that the orthophoto production procedure must be improved in order to produce orthophotos in the same year just after the photograph takings. Necessary studies about the storage, management and presentation of the huge amounts of orthophoto images to the users must be started immediately. In this study; metadata components of the produced orthophotos compatible with the international standards have been defined, a relational database has been created to keep complete and accurate metadata, and a user interface has been developed to insert the metadata into the database. Through the developed software, some extra time has been saved while creating and querying the metadata. Source


Yildirim K.,Mus Alparslan University | Kucuk I.,YTU
Journal of the Franklin Institute | Year: 2016

Optimal piezoelectric vibration control problem for a Timoshenko beam is considered. The performance index function to be minimized by using the minimum level of the control voltage consists of a weighted quadratic function of displacement and velocity of the beam and also includes a quadratic functional of the control voltage function as a penalty term. The optimal control function is derived by means of a maximum principle which transforms the control problem to an initial-boundary-terminal value problem. In order to show the effectiveness of the control actuation, numerical results are given by MATLAB in table and graphical forms. © 2015 The Franklin Institute. Source


Yastikli N.,YTU | Uzar M.,YTU
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives | Year: 2013

In this study, the automatic building extraction is aimed using object-based image analysis method with multi sensor system includes LiDAR, digital camera and GPS/IMU. The image processing techniques, segmentation and classification methods were used for automatic object extraction with defined rule set. The proposed method based on object based classification to overcome the limitation of traditional pixel based classification such as confusion of classes. The generated Digital Surface Model (DSM) from LiDAR point cloud was used to separate building and vegetation classes. The morphologic filters were utilized also optimization of mixed classes. In our proposed approach for building extraction, multi-resolution, contrast-difference and chessboard segmentations were applied. The object-based classification method was preferred in classification process with defined fuzzy rules. First, vegetation and ground classes were generated than building regions were derived with using the results of the classification and segmentation. The data set was obtained from the project of "NABUCCO Gas Pipeline Project". The data set actually was collected for corridor mapping of pipeline which will link the Eastern border of Turkey, to Baumgarten in Austria via Bulgaria, Romania and Hungary. The study area is a suburban neighborhood located in the city of Sivas, Turkey. The Leica ALS60 LiDAR system, DiMAC, Dalsa Area Bayer RGB Charge Coupled (CCD) Camera and GPS and CUS6 IMU system were used for data collection. The additional data sets were generated with point cloud collected by LiDAR and RGB images from digital camera. The rule sets for automatic building extraction were developed in Definiens e-Cognition Developer 8.64 program system. To evaluate the performance of proposed automatic building extraction approach, reference data set was generated with digitizing of extracted building over the orthoimage. The accuracy assessment was performed with completeness and correctness analyses. Based on the completeness and accuracy analysis, the success rates of 83.08% for completeness and 85.51% for correctness were achieved. Source

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