The Use of Poro-Elastic Finite Elements to Model the Structural Damping Effect of Fibrous Acoustical Treatments

Recently, new models for limp, fibrous sound absorbing materials have been proposed and verified. It has also been shown that these models may be used to optimize the sound absorption and barrier performance of layered acoustical systems. During that work, it was noticed that layers of fibrous materials can, under some circumstances, provide significant damping when they are applied to panel structures. It has since been shown that that structural damping effect may be predicted analytically by using a modal expansion procedure. The latter approach, however, can only conveniently be applied in circumstances when the vibrating structure has a simple shape and boundary conditions. Thus, in the work reported here it was of interest to demonstrate that the damping effect created by fibrous materials could also be predicted by using a finite element procedure. Successful application of the finite element method would then allow the damping effect of fibrous materials on arbitrarily shaped vibrating bodies to be studied. The poro-elastic finite element model that was used here to model the fibrous material has been described extensively elsewhere. That model has now been incorporated into a software package known as SAFE (Structural Acoustic Finite Element), an analysis module of the finite/boundary element package, COMET/Acoustics. The SAFE package was used to make the calculations reported here. The detailed objectives of the present work were first to duplicate analytical structural damping predictions by using a finite element approach, and thus to verify the earlier predictions. Secondly, it was desired to gain experience with modeling limp, fibrous materials by using SAFE. Finally, it was of interest to begin to optimize the acoustical behavior of acoustical materials by using numerical tools, and to examine the impact of these materials on the structural vibration of automotive panels, for example

Constructing pairs of dual bandlimited frame wavelets in L2(Rn)L^2(\mathbb{R}^n)

Given a real, expansive dilation matrix we prove that any bandlimited function $\psi \in L^2(\mathbb{R}^n)$, for which the dilations of its Fourier transform form a partition of unity, generates a wavelet frame for certain translation lattices. Moreover, there exists a dual wavelet frame generated by a finite linear combination of dilations of $\psi$ with explicitly given coefficients. The result allows a simple construction procedure for pairs of dual wavelet frames whose generators have compact support in the Fourier domain and desired time localization. The construction relies on a technical condition on $\psi$, and we exhibit a general class of function satisfying this condition.Comment: 21 pages, 6 figure

PrivGenDB: Efficient and privacy-preserving query executions over encrypted SNP-Phenotype database

Searchable symmetric encryption (SSE) has been used to protect the confidentiality of genomic data while providing substring search and range queries on a sequence of genomic data, but it has not been studied for protecting single nucleotide polymorphism (SNP)-phenotype data. In this article, we propose a novel model, PrivGenDB, for securely storing and efficiently conducting different queries on genomic data outsourced to an honest-but-curious cloud server. To instantiate PrivGenDB, we use SSE to ensure confidentiality while conducting different types of queries on encrypted genomic data, phenotype and other information of individuals to help analysts/clinicians in their analysis/care. To the best of our knowledge, PrivGenDB construction is the first SSE-based approach ensuring the confidentiality of shared SNP-phenotype data through encryption while making the computation/query process efficient and scalable for biomedical research and care. Furthermore, it supports a variety of query types on genomic data, including count queries, Boolean queries, and k'-out-of-k match queries. Finally, the PrivGenDB model handles the dataset containing both genotype and phenotype, and it also supports storing and managing other metadata like gender and ethnicity privately. Computer evaluations on a dataset with 5,000 records and 1,000 SNPs demonstrate that a count/Boolean query and a k'-out-of-k match query over 40 SNPs take approximately 4.3s and 86.4{\mu}s, respectively, that outperforms the existing schemes

The Moderating Effect of Different Types of Internet Use on the Relationship between Transitional Aging Changes and Self-esteem of Older Adults

This study investigates the moderating effect of different types of Internet use regarding the relationship between three transitional aging changes and self-esteem of older adults. The current paper is still in progress; this is a research-in-progress paper. An aging population increases government expenditures and family responsibilities, thus drawing more attention from the academic community. Recent research posits that self-esteem tends to decline in individuals from the ages around 50-65 due to role loss, social loss, and dissatisfaction resulting from unaccomplished life goals. To address this issue, previous studies considered that the general use of the Internet may help to enhance self-esteem among older adults. To fill this research gap, the present study proposes that the cultural use of the Internet could moderate role loss of older adults, while social use of the Internet could mitigate social loss. Furthermore, economic use could moderate the dissatisfaction of unfulfilled life goals. Regarding various theoretical contributions, this is the first study to apply different types of Internet use, so as to investigate its moderating effect concerning the relationship between transitional aging changes and self-esteem. Findings of the present study can also help shed light on interventions for the caregiver in both community centers and the domestic environment to moderate the decline of self-esteem among older adults. The data will be collected through surveys distributed to District Elderly Community Centers (DECCs) in Hong Kong. Multiple regression analysis will then be utilized to test the moderating effect of each type of Internet use

An Institutional Theory perspective on sustainable practices across the dairy supply chain

AbstractThe need for sustainable practices in the food supply chain, particularly in the area of energy reduction, is becoming acute. The food industry currently has to contend with multiple competing pressures alongside the new challenges of sustainable production. We applied Institutional Theory to explore the role of supermarkets in the development of legitimate sustainable practices across the dairy supply chains. The paper focuses on dairy supply chain organizations and their consumption of energy. We conducted 70 semi-structured telephone interviews with various stakeholders across the supply chain. Findings revealed that the majority of actors in the supply chain identified supermarkets as the dominant player, and that the supermarkets exert pressure on other smaller organizations across the supply chain. Although some organizations wished to pursue a sustainable agenda through integrating new rules and legitimate practices within their own organization, the dominant logic appeared to be one of cost reduction and profit maximization. There was also evidence that supermarkets and other large organizations attempt to replicate publicly available information on green successes for image purposes. We conclude that the dominant logic of cost reduction is so well established that challenging the dominant logic may prove difficult. The challenge is therefore to complement the dominant logic with sustainable practices across the whole supply chain, a role Government needs to play. This will require a broader more systemic approach to encouraging sustainable practices including investment and financing practices, so that all members of the dairy supply chain can co-operate and contribute to energy reduction

Practical Encrypted Network Traffic Pattern Matching for Secure Middleboxes

Network Function Virtualisation (NFV) advances the adoption of composable software middleboxes. Accordingly, cloud data centres become major NFV vendors for enterprise traffic processing. Due to the privacy concern of traffic redirection to the cloud, secure middlebox systems (e.g., BlindBox) draw much attention; they can process encrypted packets against encrypted rules directly. However, most of the existing systems supporting pattern matching based network functions require the enterprise gateway to tokenise packet payloads via sliding windows. Such tokenisation induces a considerable communication overhead, which can be over 100$\times$ to the packet size. To overcome this bottleneck, in this paper, we propose the first bandwidth-efficient encrypted pattern matching protocol for secure middleboxes. We resort to a primitive called symmetric hidden vector encryption (SHVE), and propose a variant of it, aka SHVE+, to achieve constant and moderate communication cost. To speed up, we devise encrypted filters to reduce the number of accesses to SHVE+ during matching highly. We formalise the security of our proposed protocol and conduct comprehensive evaluations over real-world rulesets and traffic dumps. The results show that our design can inspect a packet over 20k rules within 100 $\mu$s. Compared to prior work, it brings a saving of 94$\%$ in bandwidth consumption

Result Pattern Hiding Searchable Encryption for Conjunctive Queries

The recently proposed Oblivious Cross-Tags (OXT) protocol (CRYPTO 2013) has broken new ground in designing efficient searchable symmetric encryption (SSE) protocol with support for conjunctive keyword search in a single-writer single-reader framework. While the OXT protocol offers high performance by adopting a number of specialised data-structures, it also trades-off security by leaking ‘partial’ database information to the server. Recent attacks have exploited similar partial information leakage to breach database confidentiality. Consequently, it is an open problem to design SSE protocols that plug such leakages while retaining similar efficiency. In this paper, we propose a new SSE protocol, called Hidden Cross-Tags (HXT), that removes ‘Keyword Pair Result Pattern’ (KPRP) leakage for conjunctive keyword search. We avoid this leakage by adopting two additional cryptographic primitives - Hidden Vector Encryption (HVE) and probabilistic (Bloom filter) indexing into the HXT protocol. We propose a ‘lightweight’ HVE scheme that only uses efficient symmetric-key building blocks, and entirely avoids elliptic curve-based operations. At the same time, it affords selective simulation-security against an unbounded number of secret-key queries. Adopting this efficient HVE scheme, the overall practical storage and computational overheads of HXT over OXT are relatively small (no more than 10% for two keywords query, and 21% for six keywords query), while providing a higher level of security

“Dogged” Search of Fresh Nakhla Surfaces Reveals New Alteration Textures

Special Issue: 74th Annual Meeting of the Meteoritical Society, August 8-12, 2011, London, U.K.International audienceCarbonaceous chondrites are considered as amongst the most primitive Solar System samples available. One of their primitive characteristics is their enrichment in volatile elements.This includes hydrogen, which is present in hydrated and hydroxylated minerals. More precisely, the mineralogy is expected to be dominated by phyllosilicates in the case of CM chondrites, and by Montmorillonite type clays in the case of CI. Here, in order to characterize and quantify the abundance of lowtemperature minerals in carbonaceous chondrites, we performed thermogravimetric analysis of matrix fragments of Tagish Lake, Murchison and Orgueil

Understandings of scientific inquiry: an international collaborative investigation of seventh grade students

Although understandings of scientific inquiry (as opposed to conducting inquiry) is included in science education reform documents around the world, little is known about what students have learned about inquiry during their primary school years. This is partially due to the lack of any assessment instrument to measure understandings about scientific inquiry. However, a valid and reliable assessment has recently been developed and published, Views About Scientific Inquiry (VASI) (Lederman J. et. al., 2014). The purpose of this large scale (i.e., 19 countries spanning six continents and including 2,960 students) international project was to get the first baseline data on what grade students have learned. The participating countries were: Australia, Brazil, Canada, Chile, China, Egypt, England, Finland, France, Germany, Israel, New Zealand, Nigeria, South Africa, Spain, Sweden, United States, Taiwan, and Turkey. In many countries, science is not formally taught until middle school, which is the rationale for choosing seventh grade students for this investigation. This baseline data will simultaneously provide information on what, if anything, students learn about inquiry in primary school, as well as their beginning knowledge as they enter secondary school