Electric field measurement using a non-perturbative method based on a calibrated electric potential sensor

We present results of finite element analysis for simple test structures which demonstrate clearly that the measurement situation is complex. The test structure consists of an open geometry parallel plate capacitor within a screened enclosure. Indeed, the presence of earthed objects, even at considerable distances, is shown to have a significant effect on the field geometry close to the source. These simulations are compared with field measurements made using an ultra-high input impedance sensor, the Electric Potential Sensor. A single experimentally determined calibration factor is all that is required to achieve excellent agreement between experimental measurements and the results of the simulations. Given this, the sensor is capable of mapping accurately, and in a non-perturbative manner, the spatial potential both within and outside of the test structure

Evaluation of limestone layer’s effect for uwb microwave imaging of breast models using neural network

X-ray mammography is widely used for detection of breast cancer. Besides its popularity, this method did not have the potential of discriminating a tumor covered with limestone from a pure limestone mass. This might cause misdetection of some tumors covered with limestone or unnecessary surgery for a pure limestone mass. In this study, Ultra-Wide Band (UWB) signals are used for the imaging. A feed-forward artificial neural network (FF-ANN) is used to classify the mass in the breast whether it is a tumor or not by using the transmission coefficients obtained from UWB signals. A spherical tumor covered with limestone and pure limestone masses were designed and placed into the fibro-glandular layer of breast model using CST Microwave Studio Software. The radius of the masses for both cases is changed from 1 mm to 10 mm with 1 mm steps. Horn antennas were chosen to send and receive Ultra-Wide Band (UWB) signals between 2 and 18 GHz frequency range. The obtained results show that the proposed method, on the contrary of the mammogram, has the potential of discriminating the tumor covered with limestone from the pure limestone, for the mass sizes of 7, 8 and 10 mm. Consequently, the UWB microwave imaging can be used to distinguish these cases from each other

Discrete Event Simulation of a Suppression of Enemy Air Defenses (SEAD) Mission

Contemporary military campaigns increasingly count on the use of air power. Suppression of enemy air defenses (SEAD) operations have been a crucial element of military air power for 50 years. Several developments and evolution in both air defense and attack systems suggest that SEAD missions will continue to have growing importance to air forces. Since SEAD operations have a significant impact on air campaigns, it is important to examine their efficiency and identify improvement opportunities. This study explores factors that influence SEAD operations through use of a discrete event simulation built in Arena and subsequent statistical analysis of the results

Batch to Real-Time: Incremental Data Collection & Analytics Platform

Real-time data collection and analytics is a desirable but challenging feature to provide in data-intensive software systems. To provide highly concurrent and efficient real-time analytics on streaming data at interactive speeds requires a well-designed software architecture that makes use of a carefully selected set of software frameworks. In this paper, we report on the design and implementation of the Incremental Data Collection & Analytics Platform (IDCAP). The IDCAP provides incremental data collection and indexing in real-time of social media data; support for real-time analytics at interactive speeds; highly concurrent batch data processing supported by a novel data model; and a front-end web client that allows an analyst to manage IDCAP resources, to monitor incoming data in real-time, and to provide an interface that allows incremental queries to be performed on top of large Twitter datasets

CYBER SECURITY IN INDUSTRIAL CONTROL SYSTEMS (ICS): A SURVEY OF ROWHAMMER VULNERABILITY

Increasing dependence on Information and Communication Technologies (ICT) and especially on the Internet in Industrial Control Systems (ICS) has made these systems the primary target of cyber-attacks. As ICS are extensively used in Critical Infrastructures (CI), this makes CI more vulnerable to cyber-attacks and their protection becomes an important issue. On the other hand, cyberattacks can exploit not only software but also physics; that is, they can target the fundamental physical aspects of computation. The newly discovered RowHammer (RH) fault injection attack is a serious vulnerability targeting hardware on reliability and security of DRAM (Dynamic Random Access Memory). Studies on this vulnerability issue raise serious security concerns.  The purpose of this study was to overview the RH phenomenon in DRAMs and its possible security risks on ICSs and to discuss a few possible realistic RH attack scenarios for ICSs. The results of the study revealed that RH is a serious security threat to any computer-based system having DRAMs, and this also applies to ICS

A Robust Finite-Difference Model Reduction for the Boundary Feedback Stabilization of Fully-dynamic Piezoelectric Beams

Piezoelectric materials exhibit electric responses to mechanical stress, and mechanical responses to electric stress. The PDE model, describing the longitudinal oscillations on the beam, with two boundary feedback controllers is known to have exponentially stable solutions. However, the reduced model by the semi-discretized Finite Elements is shown to lack of exponential stability uniformly as the discretization parameter tends to zero. This is due to the loss of uniform gap among the high-frequency eigenvalues. In this paper, an alternate Finite-Difference based model reduction is investigated by cleverly reducing the order of the model together with the consideration of equidistant grid points and averaging operators. This new model reduction successfully retains the exponential stability uniformly as the discretization parameter tends to zero. Moreover, it does not need a further numerical Fourier filtering. Our results are based on a careful construction of a Lyapunov function. The numerical simulations are provided to compare reduced models and to show the strength of introduced results.Comment: 8 figures, 2 table

Antenna Selection For Receive Spatial Modulation System Empowered By Reconfigurable Intelligent Surface

Reconfigurable intelligent surface (RIS) enhances signal quality by adjusting the phase of electromagnetic waves in wireless communication. Spatial modulation (SM), a prominent index modulation (IM) technique, provides high spectral efficiency and low energy consumption. In this article, a new wireless communication system is proposed by combining capacity-optimized antenna selection (COAS), antenna correlation antenna selection (ACAS), and Euclidean distance-optimized antenna selection (EDAS)-supported RIS-empowered receive SM (RIS-RSM) system (AS-RIS-RSM) in a single-input multiple-output (SIMO) structure. The proposed AS-RIS-RSM schemes (COAS-RIS-RSM, ACAS-RIS-RSM, and EDAS-RIS-RSM) have superior features such as high spectral efficiency, high energy efficiency, and low error data transmission. Integrating COAS, ACAS, and EDAS techniques into the system enables the selection of the channel with the best conditions, thus increasing the error performance of the proposed system. Also, using RIS increases the error performance of the system by controlling the transmitted signal to a certain extent. The analytical ABER results of the proposed AS-RIS-RSM systems are derived and shown to overlap with simulation results. For the proposed systems, an optimal maximum likelihood (ML) detector and a sub-optimal low-complexity greedy detector (GD) are offered. Also, capacity analyses of the proposed AS-RIS-RSM systems are derived and it is observed that they have higher capacity compared to RIS-QAM/PSK and RIS-RSM systems. Then, computational complexity analyses of the proposed COAS-RIS-RSM, ACAS-RIS-RSM, and EDAS-RIS-RSM systems are presented. The proposed systems have been compared to counterpart wireless communication systems including RIS-RSM, RIS-QAM, and RIS-PSK under equivalent conditions, demonstrating that the proposed systems achieve better error performance.Comment: 10 pages, 3 Tables, 6 Figur

Corporate Governance and Firm Performance: Recent Evidence from Borsa Istanbul (BIST) Corporate Governance Index (XKURY)

As competition for foreign and domestic investment increases, firms look for new ways to remain competitive in today's complex business environment.  Good corporate governance is rewarded with higher market valuation and companies with better corporate governance practices enjoy higher price-to-book ratios. Investors are actually ready to pay a premium for a company that is respectful to corporate governance practices.  In this study, we aim to analyze the impact of several accounting ratios on the corporate governance scores of the selected companies from the Borsa Istanbul (BIST) Corporate Governance Index (XKURY). Our study covers the period of 2008 and 2014. To conduct our study, we selected three types of ratios : liquidity ratios, profitability ratios and operating efficiency ratios. Our results reveal the positive impacts between the liquidity ratios of Net Cash Flow by Operating Activities and Net Working Capital to Total Assets on the corporate governance rating scores. On the other hand, we could not obtain any significant associations between profitability ratios, operating efficiency ratios and corporate governance levels of the firms. Keywords : Corporate governance, firm performance, accounting ratios, liquidity ratios, Borsa Istanbul (BIST) Corporate Governance Index (XKURY

Vectorization of Large Amounts of Raster Satellite Images in a Distributed Architecture Using HIPI

Vectorization process focus on grouping pixels of a raster image into raw line segments, and forming lines, polylines or poligons. To vectorize massive raster images regarding resource and performane problems, weuse a distributed HIPI image processing interface based on MapReduce approach. Apache Hadoop is placed at the core of the framework. To realize such a system, we first define mapper function, and then its input and output formats. In this paper, mappers convert raster mosaics into vector counterparts. Reduc functions are not needed for vectorization. Vector representations of raster images is expected to give better performance in distributed computations by reducing the negative effects of bandwidth problem and horizontal scalability analysis is done.Comment: In Turkish, Proceedings of International Artificial Intelligence and Data Processing Symposium (IDAP) 201

The Probable Effects of the Modernization of the Customs Union Upon the International Road Transportation Sector: Izmir Region Example

This study aims to detect the probable effects of the modernization of the European Union (EU) - Turkey Customs Union upon the international road transportation sector. Izmir region has been selected as a research area. Izmir is located in the Aegean region, which is the third biggest city and second biggest port of Turkey. With its developed industry due to the region’s raw material resources, qualified labor force, and wide range of transportation opportunities, Izmir is one of the important trade centers, ranking second after the Marmara Region in terms of industry. Closeness to the landlocked centers with high processing capacities such as Manisa, Denizli, Aydin, Mugla, Bursa, Usak, Kutahya, and the presence of around 1,700 companies with international capital makes Izmir more critical for the logistics sector. Thus, it is considered an acceptable sample area for the research. A semistructured interview technique has been used in the investigation. According to the results of interviews with 19 international road transporters in Izmir, the modernization of the Customs Union will increase Turkey’s competitiveness of trading in goods and services with the EU countries. Removing the obstacles like visa problems, limitations on the free movement of drivers and transportation services, transit tolls that the Turkish road transport companies face in the EU member states, the modernization of the Customs Union will benefit both Turkish road transporters and exporters, as well as increase trade volume between the sides