In this paper, the particle swarm optimization (PSO) technique is used in optimising the proportional integral derivative (PID) controller parameters for the exhaust temperature control of a gas turbine system. The performance of the PID controller whose parameters are tuned based on the PSO method (PSO-PID) is compared with the conventional PID (CPID) controller that employs the Ziegler-Nichols method. A new performance criterion, known as multipurpose performance criterion (MPPC) is proposed and used in the PSO algorithm. Time domain performance of the PSO-PID controller, such as the maximum overshoot , rise time , settling time and absolute error (AE) are being optimized based on the MPPC and compared with other performance criteria such as the integral of time multiplied by absolute error (ITAE), integral of time multiplied by square error (ITSE), integral square error (ISE) and integral of absolute error (IAE). Result shows that the PSO technique, combined with the MPPC performance criterion is very effective to yield optimal transient response of the gas turbine exhaust temperature. An adjustable weighting factor in the MPPC technique makes it more reliable, consistent and flexible as compared to the commonly used performance criteria.

We study problems of intercepting single and multiple invasive intruders on a boundary of a planar region by employing a team of autonomous unmanned surface vehicles. First, the problem of intercepting a single intruder has been studied and then the proposed strategy has been applied to intercepting multiple intruders on the region boundary. Based on the proposed decentralised motion control algorithm and decision making strategy, each autonomous vehicle intercepts any intruder, which tends to leave the region by detecting the most vulnerable point of the boundary. An efficient and simple mathematical rules based control algorithm for navigating the autonomous vehicles on the boundary of the see region is developed. The proposed algorithm is computationally simple and easily implementable in real life intruder interception applications. In this paper, we obtain necessary and sufficient conditions for the existence of a real-time solution to the considered problem of intruder interception. The effectiveness of the proposed method is confirmed by computer simulations with both single and multiple intruders.

Background & Objective: Cyclic mastalgia is clinically related to alterations in sex hormone levels during the menstrual cycle. A derangement in normal menstrual cycle leads to exacerbated mastalgia; which can also cause menstrual irregularities and abnormal uterine bleeding (AUB). A decrease in severity of mastalgia is observed in patients with simultaneous cyclic mastalgia and menstrual irregularities/AUB, following correction of menstrual irregularity. This study was designed and conducted to investigate the possibility of whether correction of menstrual irregularities can diminish cyclic mastalgia. Materials & Methods: This case-control study was carried out on women suffering from simultaneous mastalgia and menstrual irregularity. One-hundred and fifty patients were randomly distributed between case and control groups, each including 75 patients. Patients in both groups took 100 mg vitamin E oral tablet daily for 3 months. Patients in case group also received low-dose oral contraceptive pills (OCP-LD) to correct menstrual irregularity. Patients recorded the severity of mastalgia in Cardiff breast pain chart using Visual Analogue Scale (VAS). Results: At the beginning of study, there was no significant difference in the number of days suffering from mild and severe mastalgia between two groups. However, at the end of the study, mild and severe mastalgia reduced significantly in the case group compared to the control group (P=0.003 and P=0.045, respectively). Conclusion: In women with cyclic mastalgia, correction of menstrual irregularity leads to significant pain relief. Correcting menstrual irregularity is suggested as a first-line treatment in women with mastalgia.

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