Tolga İnan

Electrical Power Quality of Iron and Steel Industry in Turkey

The iron and steel industry has been growing increasingly in Turkey in the last decade. Today, its electricity demand is nearly one tenth of the installed generation capability of 40 GW in the country. In this paper, power quality (PQ) investigations based on the arc furnace installations of the iron and steel plants using field measurements according to the international standard IEC 61000-4-30 are documented. Interharmonics and voltage flicker problems occurring both at the common-coupling points of those plants and at the arc furnace and static VAr compensator (SVC) systems of the plants themselves are determined with the use of GPS receiver synchronization modules attached to the mobile PQ measurement systems. It has been observed that flicker and interharmonic problems are dominant at the points of common couplings where arc furnace installations are supplied. Based on the field measurements obtained with collaborative work of five arc furnace plants, it is possible to say that contemporary SVC systems cause interharmonic amplification problems around the second harmonic, and novel methods are required to solve this problem.

Multipurpose Platform for Power System Monitoring and Analysis With Sample Grid Applications

This paper is devoted to the design and implementation of a multipurpose platform (MPP) for power system monitoring and analysis. This MPP is a novel device, which combines the abilities of a power quality (PQ) analyzer, an event logger, a synchronized phasor measurement unit, and an interarea oscillation identifier, all in one device. The multiple functions of the proposed MPP can serve the needs of the power system operators (SOs) as a wide-area monitoring system to observe the states and stability of the power system, and as a PQ analyzer to monitor the PQ events and parameters, permanently. Furthermore, the algorithms of flicker and harmonic current contributions at a point of common coupling can be embedded on this MPP, to determine the individual contributions of different loads supplied from the same bus. The operational features of the developed MPP have been tested on the Turkish electricity transmission system and its interfaces with the distribution system by installing 450 MPPs and integrating them with a monitoring and control center. The proposed all-in-one MPP can therefore meet the multiple requirements of the power SOs to serve the needs of modern electricity markets and convert an ordinary electricity system to a smart grid.

3-D Face Recognition With Local Shape Descriptors

In this paper, we present a novel automatic approach based on local shape descriptors to discriminate 3-D facial scans of different individuals. Our approach begins with registration, smoothing and uniform resampling of 3-D face data. Then, uniformly resampled 3-D face data are used to generate shape index, curvedness, gaussian and mean curvature values on each point of the data. Hence we obtain 2-D matrices of shape index, curvedness, gaussian and mean curvature values representing 3-D geometry information. SIFT descriptors are applied to 2-D matrices and high dimensional feature vector having shape information is obtained. Finally, high dimensional feature vector is projected to the low dimensional subspace where projection matrix is calculated by linear discriminant analysis. Features in this low dimensional subspace are compared by using cosine distance similarity metric. Proposed method is shown to have 98.35% and 98.25% detection rates at 0.001 false alarm rate for All vs. All and ROC3 experiments respectively on FRGC v2.0 database. To the best of our knowledge, these are the best results among similar studies available in 3-D face recognition literature.

PQONT: A domain ontology for electrical power quality

Electrical power quality (PQ) data is a ubiquitous type of engineering data quantified as a set of PQ parameters, such as frequency, flicker, and harmonics, obtained from electricity transmission and distribution systems. For PQ problems detected as deviations from nominal power system behavior negatively affect the workings of governmental and industrial institutions, as well as the electronic equipment and the psychology of individual humans, several systems of varying complexities to measure and monitor PQ parameters have been developed in order to detect the problems and take the necessary countermeasures. Yet, the domain of PQ data still suffers from the lack of a common vocabulary to be shared by the involved parties. In this paper, a novel domain ontology for electrical PQ, called PQONT, is presented to fulfill this need. Relevant standards and regulations have been utilized extensively during the ontology building process. The proposed ontology also supports linguistic applications by providing a number of linguistic properties applicable to all of its concepts. This facility of the ontology is employed in a multilingual natural language based interface for PQ data collected through a nationwide PQ measurement system so that the data can be queried in a flexible way. The implementation details of the interface is presented with a couple of query examples to illustrate the contribution of the ontology to a real application. The future work includes the extension of PQONT to a more general power system ontology so that it can contribute to a wider range of applications in the power system domain.

National Power Quality Monitoring network and assessment center for the Turkish Electricity Transmission System: Recent developments

In this paper, the National Power Quality Monitoring System, which is designed to monitor the power quality (PQ) of the Turkish Electricity Transmission System is presented. The National PQ Monitoring System consists of three main parts: PQ monitors, which are installed all over the country; a monitoring center, which collects the data sent by the power quality monitors in a database and provides assessment facilities; and a client software for remote connection to the center and analysis of the collected PQ data. PQ monitors compute the PQ parameters according to the IEC-Standard-61000-4-30. The PQ monitoring center is located in the TEIAS Ankara Bahcelievler campus and it has a huge digital light processing (DLP) display to observe the PQ events on the map of Turkey as soon as the event occurs. The client software provides remote connection from universities, research institutes and TEIAS offices to the monitoring center to analyse the collected PQ data. This is a three-year project which started in March 2006 To date, PQ monitor design has been completed. 9 monitors have been installed at various transformer substations in Turkey and the monitoring center is now collecting and displaying PQ data continously. 150 PQ monitors will have been installed by the end of the project all over the country and the PQ of the whole electricity transmission system will be monitored. Some measurement results obtained upto now are also presented in this paper.

Building an ontology for flexible power quality querying

Electrical power quality (PQ) is measured as a set of PQ parameters, such as frequency, flicker, and harmonics, obtained from electrical transmission and distribution systems. The domain of electrical PQ suffers from the lack of a common vocabulary to be shared by the involved parties. There exist several systems of varying complexities to measure PQ parameters, yet no ontology development effort for PQ data has been reported in the literature. In this paper, a novel and generic domain ontology for electrical PQ is presented. During the ontology development process, relevant standards as well as experiences gained during the development of two distinct large-scale systems for nationwide PQ monitoring have been used. Among these monitoring systems, one is a mobile measurement system which has collected sample PQ data of considerable size all over the Turkish electricity transmission system to detect problematic locations. The second system, which aims to perform on line PQ monitoring with permanent monitors, is the successor of the previous one and has recently started to collect data at several problematic points in the transmission system. The PQ ontology is especially important for its being the first attempt to create a common vocabulary for the domain and hence to make differing PQ monitoring systems interoperable. The proposed ontology is utilized to develop a natural language based interface for querying the PQ data collected through mobile measurement system, in a flexible way. The implementation details of the interface is presented with a query example on the PQ data. The future work will include the extension of this natural language based interface into a speech recognition engine to get spoken queries into the system and enhance the interface to handle queries in Turkish.

Effects of 3D registration on subspace based face recognition methods

The effect of 3D registation is examined through various subspace based recognition algorithms. Iterative Closest Point (ICP) algorithm and its variations are used for registration and Eigenface, Fisherface, NMF (Nonnegative Matrix Factorization) and ICA (Independent Component Analysis) are used for recognition. It is observed that ICP and its variations converges to the place on the database FRGC v.1 used. Among the recognition algorithms Fisher-face and ICA are performed better than the others.

A comparison of PCA, LDA and DCVA in ear biometrics classification using SVM

Despite increasing three dimensional recognition rate in ear biometric, there is need for special equipment to three dimensional image. Ear biometrics recognition rate was obtained high success by combined distinctive common vector approach methods with support vector machines in two-dimensional low-resolution cameras used surveillance and security system. In particular, this method will provide an important contribution to the non-cooperative personnel identification.

Investigation of the effect of face regions on local shape descriptor based 3D face recognition

In this study, the effect of face regions on local shape descriptor based 3D face recognition was investigated. Our approach starts with calculation of the SIFT descriptors on the shape maps of the 3D faces. In the next phase, SIFT descriptors in the selected regions are concatenated to form feature vectors. Then these feature vectors are fed into linear discriminant analysis (LDA) for face recognition. In this study, faces are segmented into 47 regions and the descriptors in one or more regions are concatenated and their effect on face recognition was investigated. Face recognition tests were conducted by using the FRGC v2.0 face database.