Flexible LDPC Decoder Architectures

Flexible channel decoding is getting significance with the increase in number of wireless standards and modes within a standard. A flexible channel decoder is a solution providing interstandard and intrastandard support without change in hardware. However, the design of efficient implementation of flexible low-density parity-check (LDPC) code decoders satisfying area, speed, and power constraints is a challenging task and still requires considerable research effort. This paper provides an overview of state-of-the-art in the design of flexible LDPC decoders. The published solutions are evaluated at two levels of architectural design: the processing element (PE) and the interconnection structure. A qualitative and quantitative analysis of different design choices is carried out, and comparison is provided in terms of achieved flexibility, throughput, decoding efficiency, and area (power) consumptio

Photoelectrochemical properties of mesoporous NiOx deposited on technical FTO via nanopowder sintering in conventional and plasma atmospheres

Nanoporous nickel oxide (NiO x ) has been deposited with two different procedures of sintering (CS and RDS). Both samples display solid state oxidation at about 3.1 V vs Li+/Li. Upon sensitization of CS/RDS NiO x with erythrosine b (ERY), nickel oxide oxidation occurs at the same potential. Impedance spectroscopy revealed a higher charge transfer resistance for ERY-sensitized RDS NiO x with respect to sensitized CS NiO x . This was due to the chemisorption of a larger amount of ERY on RDS with respect to CS NiO x . Upon illumination the photoinduced charge transfer between ERY layer and NiO x could be observed only with oxidized CS. Photoelectrochemical effects of sensitized RDS NiO x were evidenced upon oxide reduction. With the addition of iodine RDS NiOx electrodes could give the reduction iodine → iodide in addition to the reduction of RDS NiO x . p-type dye sensitized solar cells were assembled with RDS NiO x photocathodes sensitized either by ERY or Fast Green. Resulting overall efficiencies ranged between 0.02 and 0.04 % upon irradiation with solar spectrum simulator (Iin : 0.1 W cm −2 )

Modified Gauss-Bonnet Gravity with Radiating Fluids

The main purpose of this paper is to investigates structure scalars in the context of $f(\mathcal{G}, T)$ gravity, where $\mathcal{G}$ is the Gauss-Bonnet invariant and $T$ is the trace of stress energy tensor. For this aim, we have considered the spherically symmetric spacetime and dissipative anisotropic fluid coupled with radiation and heat ejecting shearing matter distributions. We have found these scalar variables by orthogonally decomposing the Riemann curvature tensor in $f(\mathcal{G}, T)$ gravity. Moreover, the evolution equations of shear and expansion are also developed with the help of these scalar functions. We have also analyzed these scalars by taking constant $\mathcal{G}$ and $T$ for dust cloud. The physical behavior of structure scalars for radiating matter distributions has been examined in the presence of modified gravity. It is shown that the evolutionary stages of relativistic stellar structures can be explored via modified scalar functions.Comment: 21 pages, submitted for publicatio

Assured deletion in the cloud:requirements, challenges and future directions

Inadvertent exposure of sensitive data is a major concern for potential cloud customers. Much focus has been on other data leakage vectors, such as side channel attacks, while issues of data disposal and assured deletion have not received enough attention to date. However, data that is not properly destroyed may lead to unintended disclosures, in turn, resulting in heavy financial penalties and reputational damage. In non-cloud contexts, issues of incomplete deletion are well understood. To the best of our knowledge, to date, there has been no systematic analysis of assured deletion challenges in public clouds. In this paper, we aim to address this gap by analysing assured deletion requirements for the cloud, identifying cloud features that pose a threat to assured deletion, and describing various assured deletion challenges. Based on this discussion, we identify future challenges for research in this area and propose an initial assured deletion architecture for cloud settings. Altogether, our work offers a systematization of requirements and challenges of assured deletion in the cloud, and a well-founded reference point for future research in developing new solutions to assured deletion

VLSI Implementation of a Non-Binary Decoder Based on the Analog Digital Belief Propagation

This work presents the VLSI hardware implementation of a novel Belief Propagation (BP) algorithm introduced in [1] and named as Analog Digital Belief Propagation (ADBP). The ADBP algorithm works on factor graphs over linear models and uses messages in the form of Gaussian like probability distributions by tracking their parameters. In particular, ADBP can deal with system variables that are discrete and/or wrapped. A variant of ADBP can then be applied for the iterative decoding of a particular class of non binary codes and yields decoders with complexity independent of alphabet size M, thus allowing to construct ecient decoders for digital transmission systems with unbounded spectral eciency. In this work, we propose some simplifications to the updating rules for ADBP algorithm that are suitable for hardware implementation. In addition, we analyze the eect of finite precision on the decoding performance of the algorithm. A careful selection of quantization scheme for input, output and intermediate variables allows us to construct a complete ADBP decoding architecture that performs close to the double precision implementation and shows a promising complexity for large values of M. Finally, synthesis results of the main processing elements of ADBP are reported for 45 nm standard cell ASIC technology

"Yeah, it does have a...Windows `98 Vibe'': Usability Study of Security Features in Programmable Logic Controllers

Programmable Logic Controllers (PLCs) drive industrial processes critical to society, e.g., water treatment and distribution, electricity and fuel networks. Search engines (e.g., Shodan) have highlighted that Programmable Logic Controllers (PLCs) are often left exposed to the Internet, one of the main reasons being the misconfigurations of security settings. This leads to the question -- why do these misconfigurations occur and, specifically, whether usability of security controls plays a part? To date, the usability of configuring PLC security mechanisms has not been studied. We present the first investigation through a task-based study and subsequent semi-structured interviews (N=19). We explore the usability of PLC connection configurations and two key security mechanisms (i.e., access levels and user administration). We find that the use of unfamiliar labels, layouts and misleading terminology exacerbates an already complex process of configuring security mechanisms. Our results uncover various (mis-) perceptions about the security controls and how design constraints, e.g., safety and lack of regular updates (due to long term nature of such systems), provide significant challenges to realization of modern HCI and usability principles. Based on these findings, we provide design recommendations to bring usable security in industrial settings at par with its IT counterpart

Malignancy with unknown primary presenting as acute cardiac tamponade: a case report

A case report of a patient presenting in cardiac tamponade that was subsequently diagnosed as being secondary to malignancy of unknown primary. The patient was treated by urgent pericardiocentesis, followed by subsequent formation of a subxiphoid pericardial window. He was discharged home and given palliative chemotherapy. Malignant pericardial effusions are common, but it is rare for a patient to present in cardiac tamponade as the presenting feature of an unidentified malignancy. The causes, diagnosis and treatment of cardiac tamponade are discussed