10 results
Search Results
Now showing 1 - 10 of 10
Conference Object Citation - WoS: 6Bar Code Localization in Wavelet Domain by Using Binary Morphology(Ieee, 2004) Öktem, REIn this paper, a wavelet transform based bar code localization algorithm is proposed. The algorithm is designed to enable fast and memory efficient application for automatic bar code recognition systems that are used in big manufacturing and distribution units. The region of interest areas are kept and other regions are discarded by applying binary morphology on wavelet transform coefficients.Conference Object Citation - WoS: 16Citation - Scopus: 35Swarm Aggregations Using Artificial Potentials and Sliding Mode Control(Ieee, 2003) Gazi, V; Ordóñez, RIn this article we build on our earlier results in [1, 2] on swarm stability. In [1, 2] we had considered aggregating swarm model in n-dimensional space based on artificial potential functions for inter-individual interactions and motion along the negative gradient of the combined potential. Here we consider a general model for vehicle dynamics of each agent (swarm member) and use sliding mode control theory to force their motion to obey the dynamics of the swarm considered in [1, 2]. In this context, the results in [1, 2] serve as a "proof of concept" for swarm aggregation, whereas the present results serve as possible implementation method for engineering swarms with given vehicle dynamics. Moreover, the presented control scheme is robust with respect to disturbances and system uncertainties.Conference Object A Segmentation Algorithm for Foreground/Background Extraction(Ieee, 2006) Oktem, Rusen; Guldogan, Esin; Gabbouj, MoncefThis paper describes a three-pass segmentation algorithm followed by a foreground/background extraction rule. Being imperfect, the basic objective of the proposed segmentation is to enable the extraction of objects that may be of main interest to the user, and the background. The formed segments are assigned points, according to the location of their center of mass and bounding box coordinates, and spatial dispersion. Each segment is labelled as foreground or background in compliance with the grade point they get.Conference Object Citation - WoS: 4A Layered Security Architecture for Corporate 802.11 Wireless Networks(Ieee, 2004) Erten, YM; Tomur, EIn this study we have investigated the security aspects of wireless local area networks and discussed the weaknesses associated with various conventional 802.11 security protocols such as WEP and 802.1x. We propose an architecture to control access to corporate 802.11 wireless networks, based on the privileges and location of users, using the tested wired network components such as VPNs and Firewalls. The presented architecture reduces the security risks in enterprise level deployment of wireless LANs.Conference Object Citation - WoS: 7Citation - Scopus: 8Formation Control of a Multi-Agent System Using Decentralized Nonlinear Servomechanism(Ieee, 2003) Gazi, VIn this article we consider the formation control problem of a system of M agents with general nonlinear dynamics. We show that the problem of the agents moving in a formation along constant or periodic trajectories can be formulated as a nonlinear output regulation (servomechanism) problem and solved using known techniques. Then, we consider the example of formation control of agents with point mass dynamics and apply the procedure. Few illustrative numerical simulation examples are also provided.Conference Object Citation - WoS: 16Target Tracking Using Artificial Potentials and Sliding Mode Control(Ieee, 2004) Gazi, V; Ordóñez, RIn this article we develop an algorithm for capturing/intercepting a moving target based on the sliding mode control method. First, we consider a "kinematic" model (in a sense) for the capture/intercept problem and develop a method for that case. Then, we build on the developed method to include general fully actuated vehicle dynamics for the pursuer agent. The algorithm is robust with respect to the system uncertainties and additive disturbances. Finally, we also provide a numerical simulation in order to illustrate the procedure.Conference Object Citation - WoS: 1Citation - Scopus: 2Changing Our Educational Institutions: Transition From Traditional To E-Learning Programs(Ieee, 2004) Yazici, A; Karakaya, Z; Dalgarno, B; Altas, IIn this. paper we examine basic elements of e-Learning, the features of the e-Learning model under implementation at Atilim University and the expected impact of the model on the organization of the institution. The paper also draws on examples at other institutions in discussing the issues that. form the dynamics of organizational change within Universities in the 21(st) century.Conference Object Citation - WoS: 9Citation - Scopus: 13Modeling of Subsonic Cavity Flows by Neural Networks(Ieee, 2004) Efe, MÖ; Debiasi, M; Özbay, H; Samimy, MInfluencing the behavior of a flow field is a core issue as its improvement can yield significant increase of the efficiency and performance of fluidic systems. On the other hand, the tools of classical control systems theory are not directly applicable to processes displaying spatial continuity as in fluid flows. The cavity flow is a good example of this and a recent research focus in aerospace science is its modeling and control. The objective is to develop a finite dimensional representative model for the system with appropriately defined inputs and outputs. Towards the goal of reconstructing the pressure fluctuations measured at the cavity floor, this paper-demonstrates that given some history of inputs and outputs, a neural network based feedforward model can be developed such that the response of the neural network matches the measured response. The advantages of using such a model arc the representational simplicity of the model, structural flexibility to enable controller design and the ability to Store information in an interconnected structure.Conference Object Citation - WoS: 1On the Decidability of Shared Memory Consistency Verification(Ieee, 2005) Sezgin, A; Gopalakrishnan, GWe view shared memories as structures which define relations over the set of programs and their executions. An implementation is modeled by a transducer where the relation it realizes is its language. This approach allows us to cast shared memory verification as language inclusion. We show that a specification can be approximated by an infinite hierarchy of finite-state transducers, called the memory model machines. Also, checking whether an execution is generated by a sequentially consistent memory is approached through a constraint satisfaction formulation. It is proved that if a memory implementation generates a non interleaved sequential and unambiguous execution, it necessarily generates one such execution of bounded size. Our paper summarizes the key results from the first author's dissertation, and may help a practitioner understand with clarity what "sequential consistency checking is undecidable" means.Conference Object Citation - WoS: 8Citation - Scopus: 12Low-power Test Pattern Generator design for BIST via Non-Uniform Cellular Automata(Ieee, 2005) Kiliç, H; Öktem, LAn efficient low-power Test Pattern Generator (TPG) design for Built-In Self-Test (BIST) is introduced. The approach uses the Non-Uniform Cellular Automata (NUCA) model. For our purpose, we designed a polynomial-time algorithm that converts the test pattern generation problem into the classical combinatorial problem called Minimum Set Covering (MSC) which is known to be NP-Complete. Solutions to the MSC problems give the low-power design topology for the test pattern sequence. Comparative analysis of the experimental results showed that even though the obtained designs lack in wiring uniformity they are promising in terms of overall performance criteria based on fault-coverage, test length, used area and dynamic power consumed.
