[서평]「The Unified Modeling Language User Guide」

The Analysis of Time Series: An Introduction, 4th edn. By C. Chatfield. ISBN 0 412 31820 2. Chapman and Hall, London, 1989. 242 pp. £13.50.

The Analysis of Time Series: An Introduction

: One use of spectral analysis of time series is to determine if two different time series are realizations from the same process This thesis develops the theory behind Krishnaiah and Schuurmann's theoretical work reported in their report Approximations to the Distributions of the Traces of Complex Multivariate Beta and F Matrices We take the trace of a test statistic calculated from the spectral density matrices of the time series and test it The thesis applies the theory to two small sample simulations (Author)

Spectral Analysis of Time Series.

This paper presents a compression/decompression scheme based on selective Huffman coding for reducing the amount of test data that must be stored on a tester and transferred to each core in a system-on-a-chip (SOC) during manufacturing test. The test data bandwidth between the tester and the SOC is a bottleneck that can result in long test times when testing complex SOCs that contain many cores. In the proposed scheme, the test vectors for the SOC are stored in compressed form in the tester memory and transferred to the chip where they are decompressed and applied to the cores. A small amount of on-chip circuitry is used to decompress the test vectors. Given the set of test vectors for a core, a modified Huffman code is carefully selected so that it satisfies certain properties. These properties guarantee that the codewords can be decoded by a simple pipelined decoder (placed at the serial input of the core's scan chain) that requires very small area. Results indicate that the proposed scheme can provide test data compression nearly equal to that of an optimum Huffman code with much less area overhead for the decoder.

/pdf/an-efficient-test-vector-compression-scheme-using-selective-39jn9tlizp.pdf

An efficient test vector compression scheme using selective Huffman coding

Background

There is growing evidence for the positive impact of mindfulness on wellbeing. Mindfulness-based mobile apps may have potential as an alternative delivery medium for training. While there are hundreds of such apps, there is little information on their quality.

Objective

This study aimed to conduct a systematic review of mindfulness-based iPhone mobile apps and to evaluate their quality using a recently-developed expert rating scale, the Mobile Application Rating Scale (MARS). It also aimed to describe features of selected high-quality mindfulness apps.

Methods

A search for “mindfulness” was conducted in iTunes and Google Apps Marketplace. Apps that provided mindfulness training and education were included. Those containing only reminders, timers or guided meditation tracks were excluded. An expert rater reviewed and rated app quality using the MARS engagement, functionality, visual aesthetics, information quality and subjective quality subscales. A second rater provided MARS ratings on 30% of the apps for inter-rater reliability purposes.

Results

The “mindfulness” search identified 700 apps. However, 94 were duplicates, 6 were not accessible and 40 were not in English. Of the remaining 560, 23 apps met inclusion criteria and were reviewed. The median MARS score was 3.2 (out of 5.0), which exceeded the minimum acceptable score (3.0). The Headspace app had the highest average score (4.0), followed by Smiling Mind (3.7), iMindfulness (3.5) and Mindfulness Daily (3.5). There was a high level of inter-rater reliability between the two MARS raters.

Conclusions

Though many apps claim to be mindfulness-related, most were guided meditation apps, timers, or reminders. Very few had high ratings on the MARS subscales of visual aesthetics, engagement, functionality or information quality. Little evidence is available on the efficacy of the apps in developing mindfulness.

Review and evaluation of mindfulness-based iPhone apps

Secret Sharing is required in situations where access to important resources has to be protected by more than one person. We propose new secret-sharing scheme that works based on parallel counting of the ones within the shares to generate the secret output. Our work presented two different modeling variations that are mainly different in the secret-sharing keys generation where both are studied elaborating their pros and cons. Our counting-based secret shares key reconstruction is implemented and simulated considering the security level required by the usage functions. Comparisons showed interesting results that are attractive to be considered. This secret sharing method is of great benefit to all multimedia secret sharing applications such as securing bank sensitive accounts and error tracking, voting systems trust, medical agreements, wills and inheritance authentication management.

Counting-based secret sharing technique for multimedia applications

The increasing complexity of systems-on-a-chip with the accompanied increase in their test data size has made the need for test data reduction imperative. In this paper we introduce a novel and very efficient lossless compression technique for testing systems-on-a-chip based on geometric shapes. The technique exploits reordering of test vectors to minimize the number of shapes needed to encode the test data. The effectiveness of the technique in achieving high compression ratio is demonstrated on the largest ISCAS85 and full-scanned versions of ISCAS89 benchmark circuits. In this paper, it is assumed that an embedded core will be used to execute the decompression algorithm and decompress the test data.

/pdf/a-geometric-primitives-based-compression-scheme-for-testing-inp1t2i0ig.pdf

A geometric-primitives-based compression scheme for testing systems-on-a-chip

This paper proposed an enhanced system for securing sensitive text-data on personal computer benefitting from the combination of both techniques: cryptography and steganography. The system security is generated by involving RSA cryptography followed by video based steganography as two sequential layers to insure best possible security gaining the advantages from both. The study modeled the system and implemented it to be tested to explore the relation between security, capacity and data dependency. The experimentations covered testing securing data within 15 different size videos showing interesting results. The research gave enhancement to capacity vs. security, as enforced unavoidable tradeoff. The work uniqueness is presented in showing different measures allowing the user and application to be the decision maker to choose. The tests provided all possibilities of accepting security of 1-LSB, 2-LSB, and 3-LSB methods detailing their effects on the cover video. The main outcome proved applicability to be adopting 3-LSB approach to give acceptable security with practical capacity preferred making 3-LSB winning among 1-LSB and 2-LSB techniques.

/pdf/enhancing-pc-data-security-via-combining-rsa-cryptography-4jqjxkzt91.pdf

Enhancing PC Data Security via Combining RSA Cryptography and Video Based Steganography

An analytical study of mobile applications for Hajj and Umrah services

Hash functions are important security primitives used for authentication and data integrity. Among the most popular hash functions are MD5, SHA-1, and RIPEMD-160, which are all based on the function MD4. This similarity can be exploited for designing a unified engine to perform all three hash functions. Hash message authentication code (HMAC) is a shared-key security algorithm that uses these hash functions alternatively for IPSec authentication. Since some other security applications, such as digital signature, also use these three hash functions, it is prudent to design a unified, reconfigurable engine that can perform any one of them alone or with HMAC. In this work, we design an HMAC-hash unit that can be reconfigured to perform one of six standard security algorithms; namely, MD5, SHA-1, RIPEMD-160, HMAC-MD5, HMAC-SHA-1, and HMAC-RIPEMD-160. This paper applied pipelining and parallelism to the design of the HMAC-hash unit to improve throughput, especially for large message sizes. We achieved higher throughput than engines that integrated three hash functions or more and comparable throughput to those integrated only two hash functions.

Esam Khan

Papers

Counting-based secret sharing technique for multimedia applications

A geometric-primitives-based compression scheme for testing systems-on-a-chip

Enhancing PC Data Security via Combining RSA Cryptography and Video Based Steganography

An analytical study of mobile applications for Hajj and Umrah services

Design and Performance Analysis of a Unified, Reconfigurable HMAC-Hash Unit