There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

The lion's share of bacteria in various environments cannot be cloned in the laboratory and thus cannot be sequenced using existing technologies. A major goal of single-cell genomics is to complement gene-centric metagenomic data with whole-genome assemblies of uncultivated organisms. Assembly of single-cell data is challenging because of highly non-uniform read coverage as well as elevated levels of sequencing errors and chimeric reads. We describe SPAdes, a new assembler for both single-cell and standard (multicell) assembly, and demonstrate that it improves on the recently released E+V-SC assembler (specialized for single-cell data) and on popular assemblers Velvet and SoapDeNovo (for multicell data). SPAdes generates single-cell assemblies, providing information about genomes of uncultivatable bacteria that vastly exceeds what may be obtained via traditional metagenomics studies. SPAdes is available online ( http://bioinf.spbau.ru/spades ). It is distributed as open source software.

SPAdes, a new genome assembly algorithm and its applications to single-cell sequencing ( 7th Annual SFAF Meeting, 2012)

International Technology Roadmap for Semiconductors 2003の要求清浄度について － シリコンウエハ表面と雰囲気環境に要求される清浄度, 分析方法の現状について －

To alleviate the complex communication problems that arise as the number of on-chip components increases, network-on-chip (NoC) architectures have been recently proposed to replace global interconnects. In this paper, we first provide a general description of NoC architectures and applications. Then, we enumerate several related research problems organized under five main categories: Application characterization, communication paradigm, communication infrastructure, analysis, and solution evaluation. Motivation, problem description, proposed approaches, and open issues are discussed for each problem from system, microarchitecture, and circuit perspectives. Finally, we address the interactions among these research problems and put the NoC design process into perspective.

Outstanding Research Problems in NoC Design: System, Microarchitecture, and Circuit Perspectives

IEEE transactions on computer-aided design of integrated circuits and systems : a publication of the IEEE Circuits and Systems Society

In this paper, we describe NoCGEN, a Network On Chip (NoC) generator, which is used to create a simulatable and synthesizable NoC description. NoCGEN uses a set of modularised router components that can be used to form different routers with a varying number of ports, routing algorithms, data widths and buffer depths. A graph description representing the interconnection between these routers is used to generate a top-level VHDL description. A wormhole output-queued 2-D mesh router was created to verify the capability of NoCGEN. Various parameterized designs were synthesized to provide estimated gate counts of 129 K to 695 K for a number of topologies varying from a 2/spl times/2 mesh to a 4/spl times/4 mesh, with constant data bus size width of 32. The NoC was simulated with random traffic using a mixed SystemC/VHDL environment to ensure correctness of operation and to obtain performance and average latency. The results show an accepted load of 53% to 55.6% with an increase in buffer depth from 8 to 32 flits for the 4/spl times/4 mesh router.

http://www.cse.unsw.edu.au/~sridevan/index_files/01261011.pdf

NoCGEN:a template based reuse methodology for Networks On Chip architecture

Today, soft errors are one of the major design technology challenges at and beyond the 22nm technology nodes. This article introduces the soft error problem from the perspective of processor design. This article also provides a survey of the existing soft error mitigation methods across different levels of design abstraction involved in processor design, including the device level, the circuit level, the architectural level, and the program level.

Processor Design for Soft Errors: Challenges and State of the Art

Side channel attacks are becoming a major threat to the security of embedded systems Countermeasures proposed to overcome Simple Power Analysis (SPA) and Differential Power Analysis (DPA), are data masking, table masking, current flattening, circuitry level solutions, dummy instruction insertions and balancing bit-flips All these techniques are either susceptible to multi-order side channel attacks, not sufficiently generic to cover all encryption algorithms, or burden the system with high area cost, run-time or energy consumption A HW/SW based randomized instruction injection technique is proposed in this paper to overcome the pitfalls of previous countermeasures Our technique injects random instructions at random places during the execution of an application which protects the system from both SPA and DPA Further, we devise a systematic method to measure the security level of a power sequence and use it to measure the number of random instructions needed, to suitably confuse the adversary Our processor model costs 19% in additional area for a simplescalar processor, and costs on average 298% in runtime and 271% in additional energy consumption for six industry standard cryptographic algorithms

/pdf/rijid-random-code-injection-to-mask-power-analysis-based-37cfsvxcr0.pdf

RIJID: random code injection to mask power analysis based side channel attacks

Approximate multipliers enable the saving of area and power for implementation of many modern error-resilient compute-intensive applications. In this paper, we first propose a novel error-configurable minimally biased approximate integer multiplier (MBM) design. The proposed MBM design is devised by coupling a unique error-reduction mechanism with an approximate log based integer multiplier. Next, we propose an optimization (by removing leading-one detection and barrel shifting logic) of the MBM and a class of state-of-the-art approximate integer multipliers (DRUM and SSM), so that they can be efficiently used in approximate floating-point (FP) multipliers. Then, we propose a set of new approximate FP multipliers and we show that these FP multipliers lie on the Pareto front on the design spaces of area versus error and power versus error. We synthesize the designs using the TSMC 45-nm standard-cell library. Results show that the MBM integer design offers optimal points in the design space, offering up to 75% area reduction and 84% power reduction with $57 \times $ power and $28 \times $ area improvement for less than 25% peak error, 7% mean error, and 4% error bias, when compared with the IEEE-754 single-precision FP multiplier. We also perform application-level evaluations of the proposed approximate integer and FP multipliers, showing that our proposed multipliers enable significant power and area reduction with minimal degradation in applications’ output quality.

Minimally Biased Multipliers for Approximate Integer and Floating-Point Multiplication

Modern embedded system execute a single application or a class of applications repeatedly. A new emerging methodology of designing embedded system utilizes configurable processors where the cache size, associativity, and line size can be chosen by the designer. In this paper, a method is given to rapidly find the L1 cache miss rate of an application. An energy model and an execution time model are developed to find the best cache configuration for the given embedded application. Using benchmarks from Mediabench, we find that our method is on average 45 times faster to explore the design space, compared to Dinero IV while still having 100% accuracy.

/pdf/finding-optimal-l1-cache-configuration-for-embedded-systems-3yr5rah5t9.pdf

Sri Parameswaran

Papers

NoCGEN:a template based reuse methodology for Networks On Chip architecture

Processor Design for Soft Errors: Challenges and State of the Art

RIJID: random code injection to mask power analysis based side channel attacks

Minimally Biased Multipliers for Approximate Integer and Floating-Point Multiplication

Finding optimal L1 cache configuration for embedded systems