The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The non-binary weight distribution and its spectral shape is developed for a partially-structured ensemble of low-density parity-check codes over finite fields. The ensemble is characterized by all degree-2 variable nodes and some of the degree-3 variable nodes being separated. It is shown that, under node separation, the typical minimum distance is strictly positive and significantly higher than...
This paper uses extrinsic-information-transfer (EXIT)-function analysis employing the reciprocal channel approximation (RCA) to obtain optimal LDPC code degree distributions for initial hard decoding (one-bit quantization of the channel output) and for decoding with the soft information provided by additional reads in both SLC (two-level cell) and MLC (four-level-cell) Flash memory. These results...
Non-binary low-density parity-check (LDPC) codes are linear block codes defined by the sparse parity-check matrix over finite fields. The weight distribution is a significant factor to evaluate error floors of LDPC codes. In this paper, we propose a probabilistic method for estimating the low part of the weight distribution of non-binary LDPC codes. Using the proposed method, we can estimate the low...
The Extended Min-Sum (EMS) algorithm for non-binary low-density parity-check (LDPC) defined over an alphabet of size q operates on truncated messages of length q′ to achieve a complexity of the order q′2. In contrast, Walsh-Hadamard (WH) transform based iterative decoders achieve a complexity of the order q log q, which is much larger for q′ ≪ q. In this paper, we demonstrate that considerable savings...
We propose a universal channel coding for continuous output system with a parametric family of channels. Our encoder is the same as the previous paper [CMP 289, 1087]. For our decoding process, we invent α-Rényi divergence version of Clarke and Barron's formula for Bayesian average distribution, which are not required in the previous paper [CMP 289, 1087]. Combing this formula and the information...
Computation of the channel capacity for the discrete memoryless channel is considered when the input size J being larger than the output size K. In this case the Arimoto-Brahut algorithm requires considerable iterations. However, the capacity is achieved by an input distribution which is supported on the set with the size at most K. Thus we propose a new algorithm in which the original capacity computation...
In this paper, we propose a generalized write channel model for bit-patterned media recording by considering all sources of errors causing some extra disturbances during write process, in addition to data dependent write synchronization errors. We investigate information-theoretic bounds for this new model according to various input distributions and also compare it numerically to the last proposed...
For a class of mixed channels that are decomposed into finitely many stationary memoryless channels, the optimum second-order coding rate, or equivalently, channel dispersion, is derived. The addressed channel, which is an instance of non-ergodic channels, is a sub-class of regular decomposable channels introduced by Winkelbauer. The second-order coding theorem can be viewed as an extension of the...
Steganalysis detects the presence of hidden information in media files. In this paper, we propose a steganalysis technique based on an estimate of the complexity of media files. The technique detects not only the presence of hidden information but also the size of the hidden information. We compare our technique to another published technique and show empirically that, in some well-defined cases,...
Data hiding schemes using complete complementary codes have been developed for image and audio signals. It has been shown that a high payload and a low bit-error-rate can be achieved by such data hiding strategies because of the ideal auto- and cross-correlation properties of complete complementary codes. The authors have proposed a disaster prevention broadcasting system based on the data hiding...
In the spread spectrum (SS) fingerprinting technique, the averaging attack has been supposed to be the most damaging attack. It is because a number of nonlinear collusion strategies is supposed to be well approximated by averaging collusion plus additive noise. In this study, we intensively evaluate the conventional assumption, and reveal its drawbacks when a SS sequence is embedded in a digital image...
It is a well-known fact that young people frequently access and post their personal data to social networking services (SNSs) to facilitate better personal relationships. However, such information on SNSs can lead to invasion of privacy. On the other hand, there has been an increasing tendency toward protecting privacy throughout the world as per the Privacy by Design (PbD) concept. Among the seven...
The idea and techniques of DoS(Denial of Service) / DDoS(Distributed DoS) attack strategy become more effective and more complex. In our research, we focus on a Slow Read DoS attack which is one of sophisticated DoS techniques. This technique prolongs time to read the response from theWeb server, although an attacker sends a legitimate HTTP request. When an attacker sends many legitimate requests,...
An automated recognition technique was proposed for providing information on such as the skeleton of thoracic aorta, diameter of each cross-section along the skeleton, curvature of it and position of the aneurysm on the aorta using multi-slice CT images. The information was indispensable to design a stent with perfect fitting to the patient's aorta aneurysm region so that the stent kept the original...
Stability of sparse signal reconstruction in the noisy case via orthogonal matching pursuit has been widely studied in the literature of compressive sensing. To guarantee exact support identification under l2 / l∞-norm bounded noise, sufficient conditions, characterized in terms of the restricted isometry constant and the minimum magnitude of the signal components, were reported in [2]. In this paper,...
In radar applications, the target velocity is commonly determined using the Doppler effect. By comparing the transmit-receive differential frequency, the Doppler frequency shift can be measured, and as a result, the target velocity can be determined.
In this paper, we propose a variable multi-pulse pulse-position-modulation (VMPPM) system with a dimming control that combines the use of pseudo-orthogonal codes and MPPM. In VMPPM, r slots are selected from n MPPM slots and codes for data are generated in each selected r slot according to source data equation [bit/frame]. Therefore, VMPPM can achieve higher data-transmission rate than the conventional...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.