Browsing by Subject "Modularity"
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Item Open Access Disrupted network topology in patients with stable and progressive mild cognitive impairment and alzheimer's disease(Oxford University Press, 2016) Pereira, J. B.; Mijalkov, M.; Kakaei, E.; Mecocci, P.; Vellas, B.; Tsolaki, M.; Kłoszewska, I.; Soininen, H.; Spenger, C.; Lovestone, S.; Simmons, A.; Wahlund, L.-O.; Volpe, G.; Westman, E.Recent findings suggest that Alzheimer's disease (AD) is a disconnection syndrome characterized by abnormalities in large-scale networks. However, the alterations that occur in network topology during the prodromal stages of AD, particularly in patients with stable mild cognitive impairment (MCI) and those that show a slow or faster progression to dementia, are still poorly understood. In this study, we used graph theory to assess the organization of structural MRI networks in stable MCI (sMCI) subjects, late MCI converters (lMCIc), early MCI converters (eMCIc), and AD patients from 2 large multicenter cohorts: ADNI and AddNeuroMed. Our findings showed an abnormal global network organization in all patient groups, as reflected by an increased path length, reduced transitivity, and increased modularity compared with controls. In addition, lMCIc, eMCIc, and AD patients showed a decreased path length and mean clustering compared with the sMCI group. At the local level, there were nodal clustering decreases mostly in AD patients, while the nodal closeness centrality detected abnormalities across all patient groups, showing overlapping changes in the hippocampi and amygdala and nonoverlapping changes in parietal, entorhinal, and orbitofrontal regions. These findings suggest that the prodromal and clinical stages of AD are associated with an abnormal network topology.Item Open Access The effect of modular systems on spatial design and diversity: analysis through constructed modular buildings(2022-07) Sunsal, BelizModular systems are prefabricated building elements as a product of modern architecture. Compared to conventional methods, modular construction systems can find a place in many different projects with their two- and three-dimensional types, however, they have never become quite popular as an architectural design method. Modular systems, which offer various alternatives in terms of materials and construction methods, are produced as prefabricated; therefore, the problems that may arise during the construction phase and the time for on-site operations are minimized. In this sense, it significantly differs from other techniques in terms of time and work control and provides an advantage. However, modular systems could not provide the necessary place for themselves in the market, and their examples were limited to specific functions and locations. This thesis proposes an analysis method to investigate this problem, through examining the effect of modular systems on spatial design and diversity. In line with this target, this study examines the existing modular building examples worldwide through the number and the distribution of spaces generated, such as public-private zones, circulation areas, and bathrooms. When the relations of these areas with each other and the unit they are located in, are analyzed; it has been observed that the spatial design and diversity vary based on the number of utilized modules and the function of the project. When the shapes of the employed modules, indoor circulation, main entrance, private zones, and the relations of these areas with each other are compared with other examined projects, it is observed that the modular systems do not concentrate on a single type. Since a single type of unit does not have the vast majority, it has been concluded that modular systems have a high potential in terms of spatial diversity and design, they can be used in different projects and functions, but the spatial performance of curvilinear- or organic form-based modules and applicable examples in earthquake zones should also be examined in detail.Item Open Access Modeling history sensitivity and orthogonally restricting aspects(CEUR-WS, 2018) Er, Nagehan Pala; Tekin, Özgür Aydın; Köksal, ÖmerIn this paper, we describe evolution problems of typical software, concentrating on history sensitivity. We start with a basic Object-Oriented design for a simple game. Then, history sensitivity problem is introduced gradually as evolution scenarios. If two different history sensitivity concerns are semantically related, the problem of orthogonally restricting aspects occurs. We elaborate on several solution approaches, namely object-oriented design approach, aspect-oriented design approach, and composition of events and actions approach to tackle the history sensitivity evolution problems in a modular and reusable manner.Item Open Access Swappable distributed MIMO controller for a VCT engine(2011) Çakmakci M.; Ulsoy, A. G.In the early days of computer control, only one centralized computer was responsible for executing the algorithms. Increasingly, computer control algorithms reside inside individual system components in a distributed fashion. Variable camshaft timing (VCT) is an appealing feature for automotive engines because it allows optimization of the cam timing over a wide range of operating conditions. In this paper, a method to distribute the discrete multiple-input mutiple-output controller for the VCT engine to improve the component swapping modularity of the VCT actuator and the EGO sensor components using network communications is presented. First, a discrete LQG controller is designed, and then this controller is distributed to the engine control unit, the VCT controller, and the EGO sensor controller in order to maximize the component swapping modularity of the system. A control oriented pre-optimization technique, which simplifies the optimization problem, and a candidate solution was devised to maximize component modularity. © 2006 IEEE.