Task Recovery in Self-Organised Multi-Agent Systems for Distributed Domains

Grid computing and cloud systems are distributed systems which provide substantial widely-accessible services to resources. Quality of service is affected by the issues around resource allocation, sharing, task execution and node failure. The focus of this research is on task execution in distributed environments and the effects of node failure on service provision. Most methods in the literature which provide fault tolerance, use reactive techniques; these provide solutions to failure only after its occurrence. In contrast, this research argues that using multi-agent systems with self-organising capabilities can provide a proactive methodology which can improve task execution in open, dynamic and distributed environments. We have modelled a system of autonomous agents with heterogeneous resources and proposed a new delegation protocol for executing tasks within their time constraints. This helps avoid the loss of tasks and to improve efficiency. However, this method on its own is not sufficient in terms of task execution throughput, especially in the presence of agent failure. Hence, we propose, a self-organisation technique. This is represented in this research by two different mechanisms for creating organisations of agents with a certain structure; we suggest, in addition, the adoption of task delegation within the organisations. Adding an organisation structure with agent roles to the network enables smoother performance, increases task execution throughput and copes with agent failures. In addition, we study the failure problem as it manifests within the organisations and we suggest an improvement to the organisation structure which involves the use of another protocol and adding a new role. An exploratory study of dynamic, heterogeneous organisations of agents has also been conducted to understand the formation of organisations in a dynamic environment where agents may fail and new agents may join organisations. These conditions mean that new organisations may evolve and existing organisations may change

Deploying self-organisation to improve task execution in a multi-agent systems

This paper discusses how the performance of a network of agents can be improved using a self-organisation technique. The multi-agent network performance can be improved by organizing the agents in clusters. Furthermore, principles of self-organisation can be used to create agent organisations triggered when some of the agents have high load. Hence, busy agents within the network may decide to create an organisation to receive extra support from other less busy agents in order to execute more tasks. The paper presents a simulation based on Repast Simphony that has been used to develop the proposed model and describes a set of experiments showing the performance of the system with and without the self-organisation technique

Development of Anti-bodies against Infliximab in Iraqi Patients with Rheumatoid Arthritis.

Background: Rheumatoid arthritis is a common chronic and destructive autoimmune arthropathy .Treatment with infliximab gives great improvement to a large numbers of patients with RA ,however, in some patients after prolonged treatment infliximab can induce anti-infliximab antibodies formation and result to loss of infliximab efficacy and active persistent disease. Objective: to investigate the frequency of anti-infliximab antibodies in Iraqi patients with rheumatoid arthritis. Patients and methods: fifty Iraqi RA patients(36 females and 14 males) compared with 50 control( 25 healthy control and 25 case control (patients with RA on other treatment) ) were included in this study from begging of March 2014 till end of September 2014.All patients were diagnosed by full history, complete clinical examination and laboratory test. Anti-infliximab antibodies were meatured using enzymelinked immunosorbent assay in serum of Iraqi patients with RA treated with infliximab more than 3 months duration. Results: Antibodies to infliximab were detected in 35(70%) Iraqi RA patients , while the patients without detectable antibodies against infliximab were 15(30%),also there were no anti-infliximab antibodies in the control groups. Conclusion: In this study, nearly three quarter of the Iraqi RA patients treated with infliximab developed anti-infliximab antibodies

Comparative experimental investigation and gap flow simulation in electrical discharge drilling using new electrode geometry

This study presents experimental and numerical investigation on the effectiveness of electrode geometry on flushing and debris removal in Electrical Discharge Drilling (EDD) process. A new electrode geometry, namely side-cut electrode, was designed and manufactured based on circular electrode geometry. Several drilling operations were performed on stainless steel 304 using rotary tubular electrodes with circular and side-cut geometries. Drilling performance was characterized by Material Removal Rate (MRR), Electrode Wear Rate (EWR), and Tool Wear Ratio (TWR). Dimensional features and surface quality of drilled holes were evaluated based on Overcut (OC), Hole Depth (HD), and Surface Roughness (SR). Three-dimensional three-phase CFD models were built using ANSYS FLUENT software to simulate the flow field at interelectrode gap. Results revealed that the overall performance of side-cut electrode was superior due to improved erosion rates and flushing capabilities, resulting in production of deep holes with good dimensional accuracy and surface quality

Oil palm leaf fibre and its suitability for paper-based products

Due to the shortage of wood as origin materials for paper-based production, agro-residue materials have been explored in the quest of finding the best alternative fibre. Oil palm leaf (OPL) is one of agro-residue that has potential due to its comparable characteristics with wood fibre. Studies on chemical compositions, fibre morphology, and mechanical property of OPL have been carried out aiming to evaluate its potential as a substitute raw material for pulp and paper-based production. The chemical compositions were analysed according to the TAPPI standard, Kurscher-Hoffner and chlorite methods accordingly. The mechanical property (tensile, tearing and bursting strengths) were determined as described in TAPPI test methods. Fibre dimensions were determined using Franklin method and analysed under the optical microscope. The content of cellulose in the OPL is determined to be 43.8%. Although, this result is lower than wood fibre (53%), OPL has higher hemicellulose content (36.4%) than the wood fibre (27.5%). In addition, the lignin content (19.7%) of OPL is in the low range of those in wood resources (18 - 25%). These parameters are important components to produce good quality pulp and will provide high mechanical strength of the paper-based products. The measured fibre length of oil palm leaf (1.13 mm) is shorter than the wood fibre (1.90 mm). Meanwhile, the mechanical property of OPL showed lower indexes than wood resources, however, tear (1.80 mN.m2/g) and burst (0.95 kPa.m2/g) indexes of OPL are higher than other published and successful wood resources (Eucalyptus). Based on the analyses, the oil palm leaf is indeed a suitable alternative of raw material for pulp and paper-based industries

Bloom Formation and Turing Patterns in an Infochemical Mediated Multitrophic Plankton Model

A two-species predator–prey plankton model is studied, where the grazing pressure of microzooplankton on phytoplankton is controlled through external infochemical mediated predation. The system stability is analyzed in order to explain the conditions for phytoplankton bloom formation and to explore system bifurcations. The interplay between the level of infochemical-mediated external predation and the phytoplankton carrying capacity is considered over a range of parameter values and the resultant system dynamics is illustrated. The model is extended to include a spatial diffusion term leading to a reaction–diffusion system that is investigated by determining the Turing space of the model. Thereafter, the bifurcation analysis of specific time-independent patterns is explored. Through time integration, the system is also shown to exhibit the potential for temporally varying spatial patterns

Synthesis of palm oil-based fatty methylhydrazide

Fatty methylydrazides (FMHs) have been successfully synthesized from palm oil. Glycerol was produced as a by-product. The synthesis was carried out by reflux palm oil with methylhydrazine in hexane. FMHs have been characterized using elemental analysis, Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance technique. The results showed that a 6:1 molar ratio of palm oil to methylhydrazine, a round 78 % maximum conversion of palm oil into FMHs and a 10 h reaction time are the optimum reaction conditions

Non-intrusive user identity provisioning in the internet of things

The Internet of Things (IoT) represents an evolutionary vision and a new era of such smart environments that encompass all identifiable things in a dynamic and interacting network of networks. Each user has wide interactions with a huge number of entities. It would be impractical to require users to confirm themselves every time they cross various network boundaries, as the frequent verification process would disrupt the users’ normal activities and degrades the overall performance. This paper presents a service provisioning framework for IoT that relies on verifying user identity using a non-intrusive method of monitoring and inferring certain types of user activities. The framework helps in supporting the purpose of the IoT for being smart, boundless, easier and safer to improve people’s lives. The proposed framework reduces the risk of identity theft that results from losing user devices, where the user identity is usually stored. It copes with the loss of the user’s ID or people impersonating other people, and raises an alarm to block an intruder from being verified as a legitimate user

Discreet verification of user identity in pervasive computing environments using a non-intrusive technique

This paper presents a new approach for verifying user identity in pervasive environments using a non-intrusive behaviour tracking technique that offers minimum interruption to the user’s activities. The technique, termed Non-intrusive Identity Assertion System (NIAS), uses knowledge of how the user uses the environment’s services to infer their identity. The technique monitors user behaviour through identifying certain types of activity without the need for detailed tracking of user behaviour, thus minimising intrusion on the user’s normal activities. The technique was evaluated using a simulated environment to assess its reliability. Simulation results show that the technique can be applied in various situations such as strict and relaxed security settings by applying different security policies. They also show that the technique is particularly effective where the environment has a mixture of high and low security resources in which case reliability could exceed 99%

Intelligent Robotic Welding Based on a Computer Vision Technology Approach

Robots have become an essential part of modern industries in welding departments to increase the accuracy and rate of production. The intelligent detection of welding line edges to start the weld in a proper position is very important. This work introduces a new approach using image processing to detect welding lines by tracking the edges of plates according to the required speed by three degrees of a freedom robotic arm. The two different algorithms achieved in the developed approach are the edge detection and top-hat transformation. An adaptive neuro-fuzzy inference system ANFIS was used to choose the best forward and inverse kinematics of the robot. MIG welding at the end-effector was applied as a tool in this system, and the weld was completed according to the required working conditions and performance. The parts of the system work with compatible and consistent performances, with acceptable accuracy for tracking the line of the welding path