Background and Objectives: Applications and systems Software that are running constantly become obsolete due to the accumulation of error conditions or the depletion of resources like physical memory or performance degradation. In this regard, Software rejuvenation has been proposed to deal with such a phenomenon and prevent Software failure in the future. This paper proposes a multiple objective of Software rejuvenation models with several policies. The purpose is to identify the right rejuvenation policy in practical situations. Methods: We model Software system with four policies using the Markov process. These policies are: (a) Software system without rejuvenation; (b) Software system with partial rejuvenation; (c) Software system with partial and full rejuvenation; and (d) Software system with four different types of rejuvenation. In the models and each policy, we consider assigning the level of performance on which the availability and operating costs are calculated. Results: To evaluate the models with the four policies, many numerical experiments were performed. For each policy, we evaluated and compared three objectives, namely performance, availability and operating costs. The experimental results states that for Software System with the policy of four different type of rejuvenation have about 18 and 16 percent improvement in performance and availability, respectively, compared with those other policies. Moreover, the operating cost of the Software system with partial rejuvenation policy is lower and more efficient than other policies. Conclusion: According to the calculated objectives and the results of the policies, it can be concluded that in systems with lower operational costs, the most appropriate policy is the Software system with four different types of rejuvenation because this policy bring the maximum possible value for the performance and availability. The result of this study showed that the combined method is not always a suitable method because its operating cost is higher than other methods and in systems that are more important in terms of cost, this policy is not appropriate.

Introduction: Intense pulsed light (IPL) has long been used for skin rejuvenation.Photo rejuvenation with red light (with or without photo sensitizer) is a newer noninvasive way for this purpose; but, until now few comparative studies between these modalities have been performed. The aim of this study was comparing efficacy, adverse effects, and compliance of intense pulsed light rejuvenation and red light photo rejuvenation in a homogeneous group of women.Methods: In this clinical trial, ten female volunteers with Fitzpatrick skin type I, II, and III were enrolled. Patients underwent 6 sessions of IPL rejuvenation at 4-week intervals on one side, and 30 photo rejuvenation session (2 times a week) with red light on the other side of their face. Improvement of the skin texture and reduction in the wrinkles were determined in two ways. Firstly, by comparing the photographs, and secondly, by measuring the skin elasticity with Reviscometer MPA 9 system, before and after the procedure.Results: Both treatments were associated with improvement in the skin texture and wrinkle depth, but red light was more effective on the nasolabial fold and IPL was more effective on the fine wrinkles.Conclusions: Red light photo rejuvenation without the use of photosensitizer can be a new, effective and safe procedure for rejuvenation.