71 research outputs found
Fuzzy based load and energy aware multipath routing for mobile ad hoc networks
Routing is a challenging task in Mobile Ad hoc Networks (MANET) due to their dynamic topology and lack of central administration. As a consequence of un-predictable topology changes of such networks, routing protocols employed need to accurately capture the delay, load, available bandwidth and residual node energy at various locations of the network for effective energy and load balancing. This paper presents a fuzzy logic based scheme that ensures delay, load and energy aware routing to avoid congestion and minimise end-to-end delay in MANETs. In the proposed approach, forwarding delay, average load, available bandwidth and residual battery energy at a mobile node are given as inputs to a fuzzy inference engine to determine the traffic distribution possibility from that node based on the given fuzzy rules. Based on the output from the fuzzy system, traffic is distributed over fail-safe multiple routes to reduce the load at a congested node. Through simulation results, we show that our approach reduces end-to-end delay, packet drop and average energy consumption and increases packet delivery ratio for constant bit rate (CBR) traffic when compared with the popular Ad hoc On-demand Multipath Distance Vector (AOMDV) routing protocol
Evaluation of university performance using BSC and ANP
Measuring the relative performance of universities play important role on better educational planning. During the past few years, balanced scorecard (BSC) has become popular among researchers as a technique for measuring the performance of business units. This method studies a particular firm in terms of four different perspectives including internal processes, learning and growth, customer and financial figures. One primary concern on using such method is that this method does not consider the relative importance of these components. In this paper, we present a hybrid of BSC with analytical network process to measure the relative performance of an educational unit in Iran
Cluster-based supplier segmentation: a sustainable data-driven approach
Purpose – Supplier segmentation provides companies with suitable policies to control each segment, thereby saving time and resources. Sustainability has become a mandatory requirement in competitive business environments. This study aims to develop a clustering-based approach to sustainable supplier segmentation. Design/methodology/approach – The characteristics of the suppliers and the aspects of the purchased items were considered simultaneously. The weights of the sub-criteria were determined using the best-worst method. Then, the K-means clustering algorithm was applied to all company suppliers based on four criteria. The proposed model is applied to a real case study to test the performance of the proposed approach. Findings – The results prove that supplier segmentation is more efficient when using clustering algorithms, and the best criteria are selected for sustainable supplier segmentation and managing supplier relationships. Originality/value – This study integrates sustainability considerations into the supplier segmentation problem using a hybrid approach. The proposed sustainable supplier segmentation is a practical tool that eliminates complexity and presents the possibility of convenient execution. The proposed method helps business owners to elevate their sustainable insights
Ergonomic Risk Factors Evaluation of Work-related Musculoskeletal Disorders by PATH and MMH in a Construction Industry
One of the prevalent injurious factors and disabilities is work-related musculoskeletal disorders (WMSDs). The aim of this study is to evaluate the risks of ergonomic factors inducing musculoskeletal disorders consequent from industrial construction by means of PATH (Posture, Activity, Tools and Handling) risk evaluation and MMH (Manual Material Handling). A cross-sectional study was conducted on 357 construction workers working in 21 different jobs of construction industry in Parand New City, south-west of Tehran, Iran. Nordic musculoskeletal questionnaire (NMQ) was used to determine the prevalence of musculoskeletal disorders. PATH was served to assess different body part postures such as back, feet, hands, also weight of tools and equipment and catching by hand (hand-catch). Most prevalence of musculoskeletal disorders was around back (30.5%) and knee (28.9%), and in opposed side elbow (4.2%) respectively. The results of Nordic musculoskeletal questionnaire (NMQ) showed that there is meaningful relation through pain of neck, wrist, hand, back and knee with workers age and working experience (
A highly adaptive and efficient router architecture for network-on-chip
Network-on-Chip (NoC) is considered to be the solution for the communication demands of future multi-core systems. Efficient buffer management is not only instrumental in the overall performance of the on-chip networks but also greatly affects the network energy consumption. To increase the quality of service in NoCs and to efficiently utilize the available hardware resources, a novel adaptive router is proposed. Exploiting the notion of adaptivity, the proposed router adapts itself in terms of buffer size allocation for each input channel according to their corresponding traffic rate at run time, thus utilizing the maximum available buffer resources and improving quality of service in NoCs. For this reason, a flexible ring buffer architecture is proposed, which can be used by all input channels in the router. Implementation results show up to 50 % in reducing power consumption and up to five times reduction in memory utilization in router architectures when compared with a traditional router. Moreover, our extensive simulation study shows that the proposed router architecture enhances the network performance by increasing the acceptance traffic rate and decreasing the average message latency
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