Arama Sonuçları

Listeleniyor 1 - 10 / 11
  • Yayın
    FCC-HH: The hadron collider: future circular collider conceptual design report volume 3
    (Springer Heidelberg, 2019-07-01) Bayındır, Cihan; Abada, Asmaa; Abbrescia, Marcello; AbdusSalam, Shehu S.
    In response to the 2013 Update of the European Strategy for Particle Physics (EPPSU), the Future Circular Collider (FCC) study was launched as a world-wide international collaboration hosted by CERN. The FCC study covered an energy-frontier hadron collider (FCC-hh), a highest-luminosity high-energy lepton collider (FCC-ee), the corresponding 100km tunnel infrastructure, as well as the physics opportunities of these two colliders, and a high-energy LHC, based on FCC-hh technology. This document constitutes the third volume of the FCC Conceptual Design Report, devoted to the hadron collider FCC-hh. It summarizes the FCC-hh physics discovery opportunities, presents the FCC-hh accelerator design, performance reach, and staged operation plan, discusses the underlying technologies, the civil engineering and technical infrastructure, and also sketches a possible implementation. Combining ingredients from the Large Hadron Collider (LHC), the high-luminosity LHC upgrade and adding novel technologies and approaches, the FCC-hh design aims at significantly extending the energy frontier to 100TeV. Its unprecedented centre of-mass collision energy will make the FCC-hh a unique instrument to explore physics beyond the Standard Model, offering great direct sensitivity to new physics and discoveries.
  • Yayın
    Photogrammetric monitoring of an artificially generated shallow landslide
    (Wiley-Blackwell, 2013-06) Akça, Mehmet Devrim
    An artificial rainfall event was applied to a forested slope in Ruedlingen, northern Switzerland. The experiment triggered a landslide which resulted in mobilising about 130m3 of debris. The event was monitored by a photogrammetric network of four cameras, operating at 5 to 8 frames per second, in order to quantify spatial and temporal changes by tracking tennis balls pegged into the ground. Image measurements were performed using automated image matching methods, implemented through a software package developed in-house. Three-dimensional coordinates of the target points were estimated by running a customised type of bundle adjustment, achieving a positioning precision of +/- 1 center dot 8cm.
  • Yayın
    Progressive damage analyses of masonry buildings by dynamic analyses
    (Springer International Publishing AG, 2020-08) Aras, Fuat; Akbaş, Tolga; Ekşi, Hızır; Çeribaşı, Seyit
    This study investigates the effects of prescribed damage on the walls of masonry buildings by experimental and numerical methods. Ambient vibration survey method was applied to an existing, two-story, unreinforced masonry building to determine its dynamic characteristics, such as mode shapes and natural frequencies. Then, the walls on two exterior sides of the building were demolished, and dynamic testing was repeated for the damaged building. As the next step, the amount of damage on the building was increased by more impacts, and the dynamic characteristics of the heavily damaged building were identified. The results obtained from the undamaged, damaged and heavily damaged building were compared, and the damage effect on the natural frequencies of the building was noted. Besides, finite element analyses of the undamaged, damaged and heavily damaged buildings were performed. It was found that, the numerical models, constructed with code-based material properties, do not sufficiently represent the dynamic behavior of masonry buildings. Secondly, as the result of the sustained damage, while the experimental and the numerical modal analyses revealed the decrease in the dominant frequencies of the building, the difference between them increases with the severity of the damage. With the framework presented in this study, the behavior of masonry buildings can better be determined and used for analysis purposes.
  • Yayın
    Identification of the material properties of microisotropic materials
    (Springer Heidelberg, 2015-07) Kiriş, Ahmet; İnan, Esin
    The vibration problem of a rectangular plate is considered in the present work. The main purpose here is to identify the upper bounds of the unknown material moduli of the microisotropic plate material. The frequency spectrum is obtained by extending Ritz Method to the present case. Three dimensional (3-D) vibration analysis is performed and some additional frequencies are observed among the classical frequencies as characterizing the microisotropic effects. These additional frequencies disappear by increasing values of microisotropic constants beyond some certain limits while the classical frequencies remain in the spectrum. The inverse problem is established for the identification of the upper bounds of the microisotropic constants as an optimization problem where an error function is minimized.
  • Yayın
    Numerical modelling of energy dissipative steel cushions
    (Korean Soc Steel Constructiın-KSSC, 2019-08) Güllü, Ahmet; Smyrou, Eleni; Khajehdehi, Arastoo; Özkaynak, Hasan; Bal, İhsan Engin; Yüksel, Ercan; Karadoğan, Hüseyin Faruk
    Energy dissipative steel cushions (EDSCs) are simple units that can be used to join structural members. They can absorb a substantial amount of seismic energy due to their geometric shapes and the ductile behavior of mild steel. Large deformation capability and stable hysteretic behavior were obtained in monotonic and cyclic tests of EDSCs in the framework of the SAFECLADDING project. Discrete numerical modeling strategies were applied to reproduce the experimental results. The first and second models comprise two-dimensional shell elements and one-dimensional flexural frame elements, respectively. The uncertain points in the preparation of the models included the mesh density, representation of the material properties, and interaction between contacting surfaces. A zero-length nonlinear link element was used in the third attempt in the numerical modeling. Parameters are recommended for the Ramberg-Osgood and bilinear models. The obtained results indicate that all of the numerical models can reproduce the response, and the stiffness, strength, and unloading and reloading curves were fitted accurately.
  • Yayın
    An automatic calibration procedure of driving behaviour parameters in the presence of high bus volume
    (Faculty of Transport and Traffic Engineering, 2019-11) Dadashzadeh, Nima; Ergün, Murat; Kesten, Ali Sercan; Zura, Marijan
    Most of the microscopic traffic simulation programs used today incorporate car-following and lane-change models to simulate driving behaviour across a given area. The main goal of this study has been to develop an automatic calibration process for the parameters of driving behaviour models using metaheuristic algorithms. Genetic Algorithm (GA), Particle Swarm Optimization (PSO), and a combination of GA and PSO (i.e. hybrid GAPSO and hybrid PSOGA) were used during the optimization stage. In order to verify our proposed methodology, a suitable study area with high bus volume on-ramp from the 0-1 Highway in Istanbul has been modelled in VISSIM. Traffic data have been gathered through detectors. The calibration procedure has been coded using MATLAB and implemented via the VISSIM-MATLAB COM interface. Using the proposed methodology, the results of the calibrated model showed that hybrid GAPSO and hybrid PSOGA techniques outperformed the GA-only and PSO-only techniques during the calibration process. Thus, both are recommended for use in the calibration of microsimulation traffic models, rather than GA-only and PSO-only techniques.
  • Yayın
    Monitoring of a laboratory-scale inland-delta formation using a structured-light system
    (Blackwell Publishing Ltd, 2016-06) Akça, Mehmet Devrim; Seybold, Hansjörg J.
    A reduced complexity model, which simulates the process of fluvial inland-delta formation, has been developed in a previous study. The results have been compared and validated with a laboratory experiment. This work elaborates the laboratory investigation in which an experimental inland delta is generated and its eroding topography is measured using a structured-light 3D scanner. The least squares 3D (LS3D) co-registration and comparison method is used for alignment as well as for comparing data epochs both spatially and temporally. A spatial precision value of around ±50 ?m (1/20 000) is achieved. A series of high-quality digital elevation models (DEMs) are generated and the space-time evolution of the inland delta is monitored and analysed, in terms of slope and topography dynamics, in the consecutive DEM layers. The combination of high-resolution scanning together with high-precision co-registration techniques allows investigation of the details of the space-time variability of the sedimentation-deposition patterns to be used for geomorphological analysis.
  • Yayın
    Quality assessment of 3D building data
    (Wiley-Blackwell Publishing, 2010-12) Akça, Mehmet Devrim; Freeman, Mark; Sargent, Isabel; Gruen, Armin W.
    Three-dimensional building models are often now produced from lidar and photogrammetric data. The quality control of these models is a relevant issue both from the scientific and practical points of view. This work presents a method for the quality control of such models. The input model (3D building data) is co-registered to the verification data using a 3D surface matching method. The 3D surface matching evaluates the Euclidean distances between the verification and input data-sets. The Euclidean distances give appropriate metrics for the 3D model quality. This metric is independent of the method of data capture. The proposed method can favourably address the reference system accuracy, positional accuracy and completeness. Three practical examples of the method are provided for demonstration.
  • Yayın
    Early detection of rogue waves by the wavelet transforms
    (Elsevier, 2016-01-08) Bayındır, Cihan
    We discuss the possible advantages of using the wavelet transform over the Fourier transform for the early detection of rogue waves. We show that the triangular wavelet spectra of the rogue waves can be detected at early stages of the development of rogue waves in a chaotic wave field. Compared to the Fourier spectra, the wavelet spectra are capable of detecting not only the emergence of a rogue wave but also its possible spatial (or temporal) location. Due to this fact, wavelet transform is also capable of predicting the characteristic distances between successive rogue waves. Therefore multiple simultaneous breaking of the successive rogue waves on ships or on the offshore structures can be predicted and avoided by smart designs and operations.
  • Yayın
    FCC-EE: The lepton collider: Future circular collider conceptual design report volume 2
    (Springer Heidelberg, 2019-06) Bayındır, Cihan; Abada, Asmaa; Abbrescia, Marcello; AbdusSalam, Shehu S.
    In response to the 2013 Update of the European Strategy for Particle Physics, the Future Circular Collider (FCC) study was launched, as an international collaboration hosted by CERN. This study covers a highest-luminosity high-energy lepton collider (FCC-ee) and an energy-frontier hadron collider (FCC-hh), which could, successively, be installed in the same 100 km tunnel. The scientific capabilities of the integrated FCC programme would serve the worldwide community throughout the 21st century. The FCC study also investigates an LHC energy upgrade, using FCC-hh technology. This document constitutes the second volume of the FCC Conceptual Design Report, devoted to the electron-positron collider FCC-ee. After summarizing the physics discovery opportunities, it presents the accelerator design, performance reach, a staged operation scenario, the underlying technologies, civil engineering, technical infrastructure, and an implementation plan. FCC-ee can be built with today's technology. Most of the FCC-ee infrastructure could be reused for FCC-hh. Combining concepts from past and present lepton colliders and adding a few novel elements, the FCC-ee design promises outstandingly high luminosity. This will make the FCC-ee a unique precision instrument to study the heaviest known particles (Z, W and H bosons and the top quark), offering great direct and indirect sensitivity to new physics.