Improved fuzzy vault scheme for fingerprint verification

Fuzzy vault is a well-known technique to address the privacy concerns in biometric identification applications. We revisit the fuzzy vault scheme to address implementation, efficiency, and security issues encountered in its realization. We use the fingerprint data as a case study. We compare the performances of two different methods used in the implementation of fuzzy vault, namely brute force and Reed Solomon decoding. We show that the locations of fake (chaff) points in the vault leak information on the genuine points and propose a new chaff point placement technique that makes distinguishing genuine points impossible. We also propose a novel method for creation of chaff points that decreases the success rate of the brute force attack from 100% to less than 3.5%. While this paper lays out a complete guideline as to how the fuzzy vault is implemented in an efficient and secure way, it also points out that more research is needed to thwart the proposed attacks by presenting ideas for future research

Pressure drop across micro-pin heat sinks under boiling conditions

Two-phase pressure drop was studied in four different micro pin fin heat sinks. Micro pin fin heat sinks used in the current studies were operated under boiling conditions using water and R-123 as working fluids. It was observed that once boiling was initiated severe temperature fluctuations and flow oscillations were recorded for three of the micro pin fin heat sinks, which was characterized as unstable boiling. Pressure drop signals were presented just before and after the unstable boiling conditions. Flow images and FFT (fast Fourier Transform) profiles of pressure signals were used to explain experimental results and unstable nature in flow boiling observed in the three of the devices. Stable boiling conditions where the temperature and pressure drop had a steady and stable profile could be only obtained from one micro pin fin heat sink at high mass velocities. The two-phase pressure drop in this hydrofoil-based micro pin fin heat sink has been investigated using R-123 as the working fluid. Two-phase frictional multipliers have been obtained over mass fluxes from 976 to 2349 kg/m2. It has been found that the two-phase frictional multiplier is strongly dependent on flow pattern. The theoretical prediction using Martinelli parameter based on the laminar fluid and laminar gas flow represented the experimental data fairly well for the spray-annular flow. For the bubbly and wavy-intermittent flow, however, large deviations from the experimental data were recorded. The Martinelli parameter was used successfully to determine the flow patterns, which were bubbly, wavy-intermittent, and spray-annular flow in the current study

Destek vektör makinesi kullanarak bağımsız bileşen tabanlı 3B nesne tanıma = Independent component based 3D object recognition using support vector machines

Bu makalede, zaman ve belleğin bileşimsel (kombinezon) patlaması olmaksızın yüksek dereceden istatistikleri kullanan bir nesne tanıma tekniği önerilmektedir. Önerilen yöntem literatürdeki iki gözde yöntem olan Bağımsız Bileşen Analizi (BBA) ve Destek Vektör Makinesi (DVM)’nin kaynaşımıdır. İmgelerdeki artıklığı gidermek ve her imge için daha düşük boyutlu öznitelik vektörleri elde etmek için BBA’yı ve sonrasında BBA adımından gelen bu öznitelik vektörlerini sınıflandırmak için DVM’nin kullanması önerilmektedir. Coil-20 veritabanı ve kendi ürettiğimiz bir 2B üretim nesneleri veritabanı için deney sonuçları verilmiştir

Nonlinear equalization for holographic data storage systems

10.1364/AO.45.002731Applied Optics45122731-2741APOP

Filter-bank modelling of multi-track optical tape

Starting from the physical model, it is shown that the two-dimensional output of a multi-track optical tape channel can be obtained by summing the outputs of a bank of linear-shift invariant filters together with the magnitude nonlinearity. This representation of the optical tape channel can be used in simulations for fast and accurate synthetic data generation and may be used to design linear and nonlinear equalisers

Two-dimensional equalization/detection for patterned media storage

Although patterned media storage (PMS) is a promising candidate for ultrahigh-capacity magnetic data storage, as the capacity of PMS increases, the bit error rate (BER) performance of the system is degraded by increased two-dimensional intersymbol interference (2D-ISI), which results from intertrack interference (ITI), intersymbol interference (ISI), and noise. To improve the system performance under these adverse effects and to increase the capacity, in this paper, we propose to use and/or devise two-dimensional equalization/detection techniques: iterative decision feedback detection (IDFD) and two-dimensional generalized partial response equalization, which is optimized in minimum mean square error (MMSE), followed by one-dimensional Viterbi algorithm (2D-GPR/1D-VA). We evaluate the performance of the proposed methods by using numerical experiments under different amounts of 2D-ISI and noise. Simulation results suggest that under high storage density, the performance of the IDFD is improved by using more iterations and that under the same computational load, 2D-GPR/1D-VA performs better than IDFD. 2D-GPR/1D-VA, therefore, is a good candidate for ultrahigh-capacity PMS

Soft Feedback Equalization for Patterned Media Storage

Patterned Media Storage (PMS) is one of the promising technologies to overcome the limitations of the conventional magnetic recording. For a high areal density PMS, both inter-track interference (ITI) and inter-symbol interference (ISI), and noise severely degrade the bit error rate (BER) performance of the system. In this work, we develop soft feedback equalization (SFE) to mitigate these adverse effects. We evaluate the performance of SFE by using numerical experiments under different amount of 2D-ISI and noise. Simulation results suggest that SFE is a good candidate for ultra-high capacity PMS. Index Terms— Patterned media, two-dimensional equalization/detection, inter-symbol interferenc

Iterative soft-minimum mean-square error equalization for digital nonlinear page-oriented memories

Digital page-oriented volume holographic memory (POVHM) is a promising candidate for nextgeneration ultrahigh capacity optical data storage technology. As the capacity of the POVHMs increases, the bit error rate performance of the system is degraded due to increased interpixel interference (IPI) and noise. To improve the system performance under these adverse effects and to increase the capacity, joint iterative soft equalizationdetection and error correction decoding might be attractive. To address that, by considering the nonlinearity inherent in the channel, an iterative soft equalization method that is optimized in the minimum mean-square error (MMSE) sense, called the iterative soft-MMSE (ISMMSE) equalization, is devised. The performance of the ISMMSE is evaluated by use of numerical experiments under different amounts of IPI and optical noise. Simulation results suggest that the ISMMSE is a good candidate for an ultrahigh capacity POVHM, which employs joint iterative equalizationdetection and decoding