Compression of encrypted digital holograms using artificial neural networks

An important aspect of security and defense is information gathering, dissemination, processing,and analysis. Central to this is the encryption and decryption of messages for storage and transmission. Although public-key cryptosystems are the state of the art currently, there is a place for private-key systems in cases where hardware implementation permits very high through puts. Optical implementation is a candidate for this. Optics has some very promising scalability advantages over purely electronic systems as, in principle, the size of the key can be increased without increasing the encryption or decryption time..

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Risk and protective factors for depression in youth

Risk and protective processes and mechanisms associated with depression in youth are discussed within a developmental–ecological framework. Risk factors at the individual (genetics, biology, affect, cognition, behaviour) and broader contextual levels (e.g., family, school, community) are proposed to interact, leading to the development of depression in youth. Transactions between these individual and contextual factors are suggested to be dynamic and reciprocal, and these transactions are expected to change over time and developmental course. The 'best bet' for the prevention of depression may be multicomponent and multilevel interventions that address the multiple risk and protective factors associated with depression. Preventive interventions need to focus on building protective factors within young people themselves, as well as creating health-promoting environments at home and at school. These interventions likely need to be long term and geared towards assisting youth across successive periods of development.30 page(s

Research review : can we justify the widespread dissemination of universal, school-based interventions for the prevention of depression among children and adolescents?

This review examines the evidence concerning the efficacy and effectiveness of universal, school-based interventions designed to prevent the development of depression in children and adolescents. It evaluates the outcomes of research in relation to standards of evidence specified by the Society for Prevention Research (Flay et al., 2005). The limited evidence available brings into doubt the efficacy and effectiveness of current universal, school-based approaches to the prevention of depression, suggesting that the widespread dissemination of such interventions would be premature. Relatively brief programs, that focus specifically on enhancing individual skills and characteristics of the individual in the absence of environmental change, may be insufficient to produce lasting effects in the prevention of depression among children and adolescents.17 page(s

Compression of Optically Encrypted Digital Holograms Using Artificial Neural Networks

Compression and encryption/decryption are necessary for secure and efficient storage and transmission of image data. Optical encryption, as a promising application of display devices, takes advantage of both the massive parallelism inherent in optical systems and the flexibility offered by digital electronics. We encrypt real-world three-dimensional (3D) objects, captured using phase-shift interferometry, by combining a phase mask and Fresnel propagation. Compression is achieved by nonuniformly quantizing the complex-valued encrypted digital holograms using an artificial neural network. Decryption is performed by displaying the encrypted hologram and phase mask in an identical configuration. We achieved good quality decryption and reconstruction of 3D objects with as few as 2 bits in each real and imaginary value of the encrypted dat

A companding approach for nonuniform quantization of digital holograms of three-dimensional objects

We apply two novel nonuniform quantization techniques to digital holograms of three-dimensional real-world objects. Our companding approach, combines the efficiency of uniform quantization with the improved performance of nonuniform quantization. We show that the performance of companding techniques can be comparable with k-means clustering and a competitive neural network, while only requiring a single-pass processing step. The quantized holographic pixels are coded using lossless techniques for the calculation of compression ratio

Compression of encrypted digital holograms using artificial neural networks

An important aspect of security and defense is information gathering, dissemination, processing,and analysis. Central to this is the encryption and decryption of messages for storage and transmission. Although public-key cryptosystems are the state of the art currently, there is a place for private-key systems in cases where hardware implementation permits very high through puts. Optical implementation is a candidate for this. Optics has some very promising scalability advantages over purely electronic systems as, in principle, the size of the key can be increased without increasing the encryption or decryption time..

Compression of encrypted digital holograms using artificial neural networks

An important aspect of security and defense is information gathering, dissemination, processing,and analysis. Central to this is the encryption and decryption of messages for storage and transmission. Although public-key cryptosystems are the state of the art currently, there is a place for private-key systems in cases where hardware implementation permits very high through puts. Optical implementation is a candidate for this. Optics has some very promising scalability advantages over purely electronic systems as, in principle, the size of the key can be increased without increasing the encryption or decryption time..