Intensive Data Management in Parallel Systems: A Survey

In this paper we identify and discuss issues that are relevant to the design and usage of databases handling massive amounts of data in parallel environments. The issues that are tackled include the placement of the data in the memory, file systems, concurrent access to data, effects on query processing, and the implications of specific machine architectures. Since not all parameters are tractable in rigorous analysis, results of performance and bench-marking studies are highlighted for several systems.     

A model for secure multimedia document database system in a distributed environment

The Internet provides a universal platform for large-scale distribution of information and supports inter-organizational services, system integration, and collaboration. Use of multimedia documents for dissemination and sharing of massive amounts of information is becoming a common practice for Internet-based applications and enterprises. With the rapid proliferation of multimedia data management technologies over the Internet, there is growing concern about security and privacy of information. Composing multimedia documents in a distributed heterogeneous environment involves integrating media objects from multiple security domains that may employ different access control policies for media objects. In this paper, we present a security model for distributed document management system that allows creation, storage, indexing, and presentation of secure multimedia documents. The model is based on a time augmented Petri-net and provides a flexible, multilevel access control mechanism that allows clearance-based access to different levels of information in a document. In addition, the model provides detailed multimedia synchronization requirements including deterministic and non-deterministic temporal relations and incomplete timing information among media objects.     

Techniques for the extraction of phytosterols and their benefits in human health: a review

This review summarizes the information on the health-promoting effects of phytosterols and the techniques for their extraction. The extraction and analysis processes of phytosterols are complex and have not been fully established. Phytosterols have significant roles in the areas of foods, nutrition, pharmaceuticals, and cosmetics. Free phytosterols extracted from plant sources are widely used in fortified foods and dietary supplements. Most phytosterols are extracted from plant matrices using organic solvents which are health and environmental hazards. However, the application of supercritical fluid in the extraction of phytosterols has offered a promising green technology in overcoming the limitations of conventional extraction.     

β-Glycosidase-assisted bioconversion of ginsenosides in purified crude saponin and extracts from red ginseng (Panax ginseng C. A. Meyer)

Major ginsenosides in ginseng (Panax ginseng) and its products are highly glycosylated, hence poorly absorbed in the gastrointestinal tract. β-Glycosidase-assisted deglycosylation of pure ginsenosides was peformed to study bioconversion mechanisms. Ginsenoside standard compounds, crude saponin, and red ginseng extracts were incubated with β-glycosidase (0.05% w/v, 55°C). β-Glycosidase has a broad specificity for β-glycosidic bonds, hydrolyzing the β-(1→6), α-(1→6), and α-(1→2) glycosidic linkages. The final metabolite of protopanaxadiol ginsenosides was Rg3 while the metabolite of protopanaxatriol ginsenosides was Rh1. β-Glycosidase treatment of red ginseng extracts resulted in a decrease in the amounts of Rb1, Rc, Re, and Rg2 after 24 h, whereas levels of the less glycosylated Rd, Rb1, Rg, Rg3, Rg1, and Rh1 forms increased. When crude saponin was incubated with β-glycosidase for 24 h, levels of Rb1, Rc, Re, and Rg1 decreased while levels of Rd, Rg3, and Rh1 increased as deglycosylated ginsenosides.     

Effects of the β‐glycosidase reaction on bio‐conversion of isoflavones and quality during tofu processing

BACKGROUND: Isoflavones are the most common group of phytoestrogens which are present in significantly large amounts in soybean and soy products such as tofu. Isoflavones occur naturally in glycoside forms having lower bioavailability than their aglycone forms. β‐Glycosidase acts as a bio‐catalyst for the conversion of isoflavone glycosides to isoflavone aglycones, raising the bioavailability of isoflavones; therefore, it can be used to improve the quality of tofu. We need to establish process conditions for the optimal outcome of the enzyme reaction in tofu. RESULTS: By using the β‐glycosidase (0.02% w/v) reaction at 55 °C for 30 min, a maximum 84.5% conversion of isoflavone glycoside to isoflavone aglycone was obtained. The enzyme reaction caused no significant effects on the sensory acceptability of soft tofu. The hardness of enzyme‐treated hard tofu increased with the coagulant amount whereas prolonged heating resulted in decrease of hardness. Incorporation of enzyme reaction before the coagulation process during soft tofu processing provided a sufficient bio‐conversion of isoflavones at optimal conditions. CONCLUSION: β‐Glycosidase can be effectively used for the bioconversion of isoflavones in soft tofu manufacturing process at optimal reaction conditions before the onset of coagulation process. Copyright © 2010 Society of Chemical Industry     

Distributed multimedia information systems: an end-to-end perspective

Emerging Web-based applications require distributed multimedia information system (DMIS) infrastructures. Examples of such applications abound in the domains of medicine, entertainment, manufacturing, e-commerce, as well as military and critical national infrastructures. Development of DMIS for such applications need a broad range of technological solutions for organizing, storing, and delivering multimedia information in an integrated, secure and timely manner with guaranteed end-to-end (E2E) quality of presentation (QoP). DMIS are viewed as catalysts for new research in many areas, ranging from basic research to applied technology. This view is a result of the fact that no single monolithic end-to-end architecture for DMIS can meet the wide spectrum of characteristics and requirements of various Web-based multimedia applications. One size does not fit all in this medium of communication. Management of integrated end-to-end QoP and ensuring information security in DMIS, when viewed in conjunction with real world constraints and system-wide performance requirements, present formidable research and implementation challenges. These challenges encompass all the sub-system components of a DMIS. The ultimate objective of achieving a comprehensive end-to-end QoP management relies on the performance and allocation of resources of each of the DMIS sub-system components including networks, databases, and end-systems. In this paper, we elaborate on these challenges and present a high level distributed architecture aimed at providing the critical functionality for a DMIS.

Interval-based conceptual models for time-dependent multimedia data

Multimedia data often have time dependencies that must be satisfied at presentation time. To support a general-purpose multimedia information system, these timing relationships must be managed to provide utility to both the data presentation system and the multimedia author. New conceptual models for capturing these timing relationships, and managing them as part of a database are proposed. Specifically, n-ary and reverse temporal relations are introduced and defined along with their temporal constraints. These new relations are a generalization of earlier temporal models and establish the basis for conceptual database structures and temporal access control algorithms to facilitate forward, reverse, and partial-interval evaluation during multimedia object playout. The proposed relations are defined to ensure a property of monotonically increasing playout deadlines to facilitate both real-time deadline-driven playout scheduling or optimistic interval-based process playout. A translation of the conceptual models to a structure suitable for a relational database is presented     

Structured Peer-to-Peer Real Time Video Transmission over Vehicular Ad Hoc Networks

Video communication over Vehicular Ad Hoc Networks (VANET) has several applications such as road safety, commercial advertisements and on-road entertainment. In this paper we present a structured peer-to-peer (P2P) network designed for the distribution of live-content, with low bandwidth consumption, within a VANET. This P2P network is modelled using a media distribution graph. The implementation of a structured network allows a peer to schedule consecutive data chunks produced by the media source by means of a scheduling algorithm. In our analysis we obtain a bound for the maximum delay between the media source and any of the peers of the network and the buffer size needed to allow consecutive scheduling. We study a type of media distribution graph and we calculate its order and diameter, which means that under stable conditions we can ensure certain quality-of-service parameters. The results of simulation over NS2 show the fitness of the mathematical analysis.