Sajaa Kh. Sadon

Antifungal Activity of Lactobacillus fermentum Te007, Pediococcus pentosaceus Te010, Lactobacillus pentosus G004, and L. paracasi D5 on Selected Foods

UNLABELLED In the search for new preservatives from natural resources to replace or to reduce the use of chemical preservatives 4 strains of lactic acid bacteria (LAB) were selected to be evaluated for their antifungal activity on selected foods. The supernatants of the selected strains delayed the growth of fungi for 23 to 40 d at 4 °C and 5 to 6 d at 20 and 30 °C in tomato puree, 19 to 29 d at 4 °C and 6 to 12 d at 20 and 30 °C in processed cheese, and 27 to 30 d at 4 °C and 12 to 24 d at 20 and 30 °C in commercial bread. The shelf life of bread with added LAB cells or their supernatants were longer than normal bread. This study demonstrates that Lactobacillus fermentum Te007, Pediococcus pentosaceus Te010, L. pentosus G004, and L. paracasi D5 either the cells or their supernatants could be used as biopreservative in bakery products and other processed foods. PRACTICAL APPLICATION The heat stability nature of the antifungal compounds produced by the LAB isolates offers a promising application of L. fermentum Te007, P. pentosaceus Te010, L. pentosus G004, and L. paracasi D5 as biopreservative in bakery products or other processed foods to replace or reduce the use of chemical preservatives.

Intelligent Dynamic Bandwidth Allocation Algorithm in Upstream EPONs

An upstream access scheme for Ethernet passive optical networks, called the intelligent fuzzy-logic-based dynamic bandwidth allocation algorithm (IFLDBA) has been proposed. The algorithm provides the allotment of bandwidth between optical network units (ONUs) and within ONUs. Fuzzy logic is used to improve the bandwidth allocation within each ONU. We compare the IFLDBA algorithm with the existing broadcast polling algorithm. The results show that IFLDBA has bandwidth utilization of up to 21% better and lower delay than the broadcast polling algorithm.

Efficient dynamic bandwidth allocation algorithm for upstream EPON

In this paper, an efficient dynamic bandwidth allocation (DBA) algorithm based fuzzy logic for upstream Ethernet passive optical networks (EPON) is proposed. The algorithm provides the allotment of bandwidth for inter optical network unit (ONU) and intra ONU. We compared the performance of DBA algorithm based fuzzy logic and DBA algorithm without fuzzy logic in terms of bandwidth utilization and delay. The results shows that the usage of fuzzy logic improve the bandwidth utilization up to 20% and about 50% reduction on the system delay is achieved.

Dynamic hierarchical bandwidth allocation using Russian Doll Model in EPON

This paper demonstrates a new hierarchical Dynamic Bandwidth Allocation algorithm using the Russian Doll Model (RDM) to allocate bandwidth for intra-Optical Network Unit (ONU) in an Ethernet Passive Optical Network (EPON). The allocation of bandwidth is based on the classification and prioritization of service. The algorithm addresses the requests of ONUs and provides differentiated services by balancing priority and fairness. The simulation results show that the proposed algorithm performs well in supporting the triple-play services, i.e. video, voice, and data, as well as making effective adjustment in balancing bandwidth sharing between the ONUs compared with two other existing Dynamic Bandwidth Allocation (DBA) algorithm. The proposed algorithms shows significant performance improvements in terms of bandwidth utilization, packet delay and the fairness.

Improving the performance of hierarchical bandwidth allocation for upstream EPON

Many issues of intra- optical network unit (ONU) bandwidth allocation in Ethernet Passive Optical Network (EPON) remain open. In this paper, we report the performance of hierarchical bandwidth allocation algorithm incorporated Russian Doll Model (RDM) as a solution to allocate bandwidth for intra- ONU in upstream EPON. The allocation of bandwidth is based on the class of service and its priority. Results confirm significant performance improvements for a wide range of traffic loads and triple-play (video, voice, and data) services in terms of the bandwidth utilization, wasted bandwidth and fairness compared with the SHDBA algorithm. The RDDBA maximum significant performance improvements compared to SHDBA is up to 30% depending on the variant and the characteristics of the network traffic. The hierarchical bandwidth allocation with RDM improves the performance of EPON by satisfying the requests of all ONUs and provide differentiated services by guaranteeing both the priority and fairness.

Efficient dynamic bandwidth allocation for upstream EPON with global priority

An efficient dynamic bandwidth allocation (DBA) algorithm with global priority is proposed for upstream Ethernet passive optical network (EPON) in this paper. The algorithm is hierarchical and it ensures that the excessive bandwidth is allocated fairly according to the priority. The simulation is done using MATLAB by comparing Efficient DBA with global priority to Efficient DBA with local priority. The results show an improvement as high as 11% in terms of the bandwidth utilization and 46% in terms of the delay.

Enhanced Hierarchical Dynamic Bandwidth Allocation Algorithm with Excess Bandwidth and SLA Techniques for Upstream Ethernet PON

Passive Optical Networks (PONs) are thought to be the next step in the development of Access Networks and providing broadband access in the “last mile” area. Ethernet PON (EPON) gains the most attention from the researchers as it offers highly flexible and cost effective solution. In this paper we propose two high level scheduler algorithms inside the Optical Line Terminal (OLT) and Optical Network Units (ONU). In the proposed Dynamic Bandwidth Allocation (DBA) algorithm, the OLT allocates the bandwidth to the ONUs in proportion to the weight associated with the excess bandwidth available, while the ONU preferentially allocates its bandwidth to queues with a strict or non strict priority order. The algorithms provide dynamic bandwidth allocation and separate the burden of queue management fairly between the customer and the network. This led to less complicated and more intelligent equipment has been used on the customer’s premises. We show the results of simulations to validate the effectiveness of algorithms presented and to provide quality of service (QoS) for triple play real time services in Ethernet passive optical networks (EPONs).

Efficient Bandwidth Allocation Methods in Upstream EPON

The Internet has become the world’s leading universal global communication infrastructure. Optical solutions are sought after at the access network to support the ever increasing demand in bandwidth. Passive Optical Networks (PONs) are seen to provide a cost effective solution for this. PON Dynamic Bandwidth Allocation (DBA) scheme provides the means for upstream traffic allocation. In this paper, the operation of several bandwidth allocation algorithms in upstream Ethernet PON (EPON) is presented. An Efficient Distributed DBA (EDDBA) that supports Quality of Service (QoS) for both inter and intra ONU allocation is proposed. The proposed scheme introduces an identical DBA algorithm running simultaneously in each ONU. The simulation performance for the proposed DBA was conducted using Prolog and shows flexibility, reliability in handling data, voice, and video traffic.

Enhanced dynamic bandwidth allocation for upstream Ethernet PON

Ethernet Passive Optical Network (EPON) is a promising solution for access network. In this paper, we propose an enhanced Sharing DBA algorithm (SDBA) that supports multiple priority queues and fairness among optical network units (ONUs) over upstream EPON. We conduct simulation using MATLAB to study the performance and validate the effectiveness of the proposed algorithm in terms of fairness, throughput and packet delay. From the result, it has been shown that the proposed algorithm improves the Quality of Service (QoS) for EPON.

Multiple access ethernet passive optical network testbed

A multiple access Ethernet Passive Optical Network (EPON) testbed is proposed to provide a platform for testing and evaluating bandwidth allocation models. A few commercial and open source network simulators are available for EPON study but it does not take into account the real environment parameters and relatively difficult to configure. This paper proposes a simple effective EPON emulator testbed using several personal computers networked together that acts as EPON devices individually using Prolog. The testbed is a reprogrammable platform, enabling the testing of protocol for the EPON environment. A Dynamic Bandwidth Allocation (DBA) study was made for the EPON upstream traffic management using the emulator to illustrate its functionality. The design parameters studied are the offered load, amount of requested bandwidth for each type of traffic and the bandwidth allocated for the respective traffic type.