Media synchronization in multimedia Web using a neuro-fuzzyframework

We consider the problem of multimedia synchronization in a Web environment. The workload generated by the multimedia server during a Web session exhibits variations that are quite different from the traffic fluctuation offered by a single media stream, e.g., a variable bit rate (VBR) video. We propose a set of parameters that can be used to characterize the workload generated by the multimedia server in a Web-type browsing environment. The workload characterization scheme is subsequently used in designing a server-based synchronization scheme. The problem of scheduling multimedia information to ensure media synchronization in a Web environment is identified as a multicriteria scheduling problem, which is NP-hard. The ability of fuzzy control to deal with multivariables makes it a good alternative for the multicriteria scheduling problem considered. Consequently, we propose a neuro-fuzzy scheduler (NFS) that makes an intelligent compromise among multicriteria by properly combining some scheduling heuristics. Performance of the NFS is compared with several known heuristics and a branch and bound algorithm. The results show that the proposed NFS ran dynamically adjust to the varying workload quite well     

UWB over fiber transmission to multiple radio access units using all-optical signal processing

An ultra-wideband over fiber architecture is proposed where multiple coherent pulsed optical signals are used for transmitting high data rate signals to five different radio access units (RAUs). The RAUs are placed in a star topology to form a broadcast distributive antenna system architecture. The architecture transmits \(5 \times 1.25\) Gbps data from control unit to the RAUs using a wavelength division multiplexed signal. The multiple pulsed optical carriers forming the wavelength division multiplexed signal are generated using a single continuous wave optical source. The data modulated coherent optical pulsed signals are all-optically converted to electrical Gaussian mono-cycle pulses at the RAUs. The proposed architecture is cost-efficient and gives good bit-error rate results.     

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     

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.     

Media Streams Scheduling for Synchronization in Distributed Multimedia Systems

In this paper, we consider the problem of multimedia synchronization based on scheduling the transmission of multimedia documents in a networked environment. Assuming channels with different bandwidth and delay characteristics are established between the multimedia server and the client, we formulate the scheduling problem to ensure interstream and intrastream synchronization as a parallel processor scheduling problem. Since the heterogeneous parallel processor scheduling problem is NP-hard, we propose two heuristic algorithms with time complexity ofO(n log n+nm), wherenis the number of data units to be scheduled andmthe number of channels available. We also develop an enumerative algorithm to obtain the exact solutions. Extensive computational simulations reveal that the heuristics consistently obtain near-optimal solutions. From the simulation results, we also identify special structures of multimedia documents along with characteristics of the available channels which affect the relative performance of the algorithms.     

Saliency detection using contrast enhancement and texture smoothing operations

An effective framework to improve the saliency maps in complex (low-contrast, small object, and similar background etc.) images is proposed. In proposed scheme, firstly weighted approximated histogram equalization is used to enhance image contrast. Secondly, edge-preserving guided filter is used to minimize the unwanted details (texture) while maintaining the edges and semantics. Afterward, iterative rolling guidance filter is also applied to perform scale-aware local operations for image abstraction. Cellular automata is then used to obtain and optimize saliency cues by exploiting local similarity. Visual and quantitative analysis with state-of-the-art existing techniques shows the significance of proposed technique.     

All-optical regenerative technique for width-tunable ultra-wideband signal generation

We demonstrate all-optical generation of width-tunable mono-cycle pulses for ultra-wideband communication. It has been shown that the width of the mono-cycle pulses can be tuned dynamically by simply varying the power of the optical signal. We also investigate the regenerative property of the nonlinear medium-based technique for the generation of mono-cycle pulses. For the purpose of comparison, ultra-wideband mono-cycle pulses are also generated through the optical delay line-based technique. It has been demonstrated through numerical simulations that the nonlinear medium-based technique is highly resilient to amplified spontaneous emission noise that is induced over the optical signal. Furthermore, we have shown that the highly nonlinear fiber-based nonlinear medium performs better than the semiconductor optical amplifier-based medium. Bit error rate measurements are taken for different values of optical signal-to-noise ratios in order to elaborate our work.

     

Wireless network resource management for Web-based multimedia document services

Advances in wireless technology and availability of portable devices with networking capabilities have enabled ubiquitous Web accessibility. This has created the need to provide advance Internet services to mobile users without causing service failures due to connection migration or handoffs. However, scarcity of wireless resources restricts the provision of multimedia services in wireless networks. We address the issue of managing wireless resources to support Web-based multimedia document services including MPEG-4-based applications, in wireless networks with a high degree of user mobility. In particular, we formulate the resource management problem in wireless networks as an optimization problem with an objective function comprising different quality of presentation parameters.     

Synchronization and storage models for multimedia objects

A technique is presented for the formal specification and modeling of multimedia composition with respect to intermedia timing. The proposed model is based on the logic of temporal intervals and timed Petri nets. A strategy is evinced for constructing a database schema to facilitate data storage and retrieval of media elements based on the temporal relationship established by the proposed modeling tool. An algorithm which allows the retrieval of media elements from the constructed database in a manner which preserves the temporal requirements of the initial specification is presented. Using the proposed model, the synchronization requirements of complex structures of temporally related objects can be easily specified     

Beaconing Approaches in Vehicular Ad Hoc Networks: A Survey

A vehicular ad hoc network (VANET) is a type of wireless ad hoc network that facilitates ubiquitous connectivity between vehicles in the absence of fixed infrastructure. Beaconing approaches is an important research challenge in high mobility vehicular networks with enabling safety applications. In this article, we perform a survey and a comparative study of state-of-the-art adaptive beaconing approaches in VANET, that explores the main advantages and drawbacks behind their design. The survey part of the paper presents a review of existing adaptive beaconing approaches such as adaptive beacon transmission power, beacon rate adaptation, contention window size adjustment and Hybrid adaptation beaconing techniques. The comparative study of the paper compares the representatives of adaptive beaconing approaches in terms of their objective of study, summary of their study, the utilized simulator and the type of vehicular scenario. After implementing the representatives of beaconing approaches, we analysed the simulation results and discussed the strengths and weaknesses of these beaconing approaches with regard to their suitability to vehicular networks. Finally, we discussed the open issues and research directions related to VANET adaptive beaconing approaches.