Yaşar University

About: Yaşar University is a education organization based out in Izmir, Turkey. It is known for research contribution in the topics: Exergy & Job shop scheduling. The organization has 760 authors who have published 1436 publications receiving 20813 citations. The organization is also known as: Yaşar Üniversitesi.

An online structurally constrained LQR design for damping oscillations in power system networks

Abstract: This paper presents an online distributed control design for suppressing inter-area oscillations in large power systems under structural constraints posed on the underlying communication network. The presence of multiple clusters of generators in a power system results in several inter-area oscillation modes. By modal analysis, we first show that the contribution of each inter-area mode on the electromechanical state response of the generators is heavily dependent on the perturbed initial state of the system. We then take advantage of this observation to design structural constraints on the communication graph. A parallelized constrained linear quadratic regulator (LQR) design is then proposed to balance the tradeoff between performance and the level of sparsity induced in the network. Algorithms for practical implementation of the design are provided. Results are compared with the full order LQR, and illustrated on the New England 39-bus power system model.

Graph Based Representations of Density Distribution and Distances for Self-Organizing Maps

Abstract: The self-organizing map (SOM) is a powerful method for manifold learning because of producing a 2-D spatially ordered quantization of a higher dimensional data space on a rigid lattice and adaptively determining optimal approximation of the (unknown) density distribution of the data. However, a postprocessing visualization scheme is often required to capture the data manifold. A recent visualization scheme CONNvis, which is shown effective for clustering, uses a topology representing graph that shows detailed local data distribution within receptive fields. This brief proposes that this graph representation can be adapted to show local distances. The proposed graphs of local density and local distances provide tools to analyze the correlation between these two information and to merge them in various ways to achieve an advanced visualization. The brief also gives comparisons for several synthetic data sets.

The Relationship between CSR and Banks' Financial Performance: Evidence from Turkey

Abstract: The aim of this paper is to analyze the bidirectional relationship between CSR practices of Turkish banks and their financial performance which is proxied by ROE, ROA and NIM for the year 2013. Content analysis is used to analyze the degree of CSR level based on a CSR index calculation and the link between performance and CSR level is investigated. The results show that ROA and ROE have no explanatory power in explaining CSR, whereas there is a bidirectional relationship between CSR and NIMs. The results point to an intuition that the banks are likely to charge the costs of CSR practices from their customers