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

https://caltcm.memberclicks.net/assets/documents/acc_aha_chf_2013_guidelines.pdf

2013 ACCF/AHA Guideline for the Management of Heart Failure: A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines

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)

Soil Chemical Analysis

Statistics for Spatial Data.

The goal of a general purpose color scanner is to determine the color of an object in a device independent color space, such as the CIE XYZ tristimulus space. Raw sensor measurements from scanners rarely correspond to CIE XYZ due to design and realizability constraints. The conversion of data from scanner RGB to a device independent color space introduces errors due to the non-colorimetric nature of the scanner and due to the noise present in measurements. This paper analyzes the relative contributions of these two components to color errors. This analysis allows the designer to determine the most cost effective device meeting required specifications.

Color scanner performance trade-offs

We propose an analytic method to overcome the trade-off between the spatial and tonal resolution of traditional clustered dot halftones. Continuous phase modulated halftones that allow variations in screen frequency in different regions of the printed image are employed and halftone screen frequency is varied according to the frequency content of the image to be halftoned. The method, which we term self-modulated halftoning, has a computational complexity similar to screening and is significantly lower than that of other adaptive methods that have previously been used to address the same problem. We demonstrate the experimental performance of self-modulated halftones and discuss its capabilities and limitations.

/pdf/self-modulated-halftones-1hlxes8704.pdf

Self-Modulated Halftones

In music performance, vibrato is an important artistic effect, where slight variations in pitch are introduced to add expressiveness and warmth. Automatic vibrato detection and analysis, although well studied for monophonic music, has rarely been explored for polyphonic music, because of the challenge in multi-pitch analysis. We propose a video-based approach for detecting and analyzing vibrato in polyphonic string music. Specifically, we capture the fine motion of the left hand of string players through optical flow analysis of video frames. We explore two methods. The first uses a feature extraction and SVM classification pipeline, and the second is an unsupervised technique based on autocorrelation analysis of the principal motion component. The proposed methods are compared with audio-only methods applied to individual instrument tracks separated from original audio mixture using the score. Experiments show that the proposed video-based methods achieve a significantly higher vibrato detection accuracy than the audio-based methods especially in high polyphony cases. Further experiments also demonstrate the utility of the approach in vibrato rate and extent analysis.

Video-Based Vibrato Detection and Analysis for Polyphonic String Music.

Spatial frequency separability is proposed as an attractive exploit for obtaining color halftone watermarking methods from monochrome clustered-dot halftone watermarking techniques. Detection of watermarks embedded in individual halftone channels is typically confounded by the cross-coupling between colorant halftone separations and scan RGB channels caused by the so-called “unwanted absorptions”. This problem is resolved in the proposed framework by utilizing spatial filtering in order to obtain estimates of individual separation halftones that are suitable for watermark detection. The effectiveness of this methodology is experimentally demonstrated by utilizing continuous phase modulation for per-separation watermark embedding. The embedded watermark patterns in the halftone separations can be clearly detected from scans using the proposed spatial separability exploit. Continuous phase modulation based per-channel embedding with detection following spatial-filtering based separation thus provides an effective watermarking method for clustered-dot color halftones.

Clustered-Dot Color HalftoneWatermarks.

The group key agreement protocol enables to derive a shared session key for the remote members to communicate securely. Recently, several attempts are made to utilize group key agreement protocols for secure multicasting in Internet of Things. This paper contributes to identify the security vulnerabilities in the existing protocols, to avoid them in future constructions. The protocols presented by Gupta and Biswas have been found insecure to ephemeral secret key leakage (ESL) attack and also, malicious insiders can impersonate an honest participant. Additionally, the protocol presented by Tan is also ESL-insecure. We also present a fix to the Tan's protocol to make it secure.

/pdf/on-the-security-of-authenticated-group-key-agreement-249bu7sx27.pdf

Gaurav Sharma

Papers

Color scanner performance trade-offs

Self-Modulated Halftones

Video-Based Vibrato Detection and Analysis for Polyphonic String Music.

Clustered-Dot Color HalftoneWatermarks.

On the Security of Authenticated Group Key Agreement Protocols