This paper deals with the modeling of a preventive maintenance strategy applied to a single-unit system subject to random failures.

According to this policy, the system is subjected to imperfect periodic preventive maintenance restoring it to ‘as good as new’ with probability

p and leaving it at state ‘as bad as old’ with probability q. Imperfect repairs are performed following failures occurring between consecutive

preventive maintenance actions, i.e the times between failures follow a decreasing quasi-renewal process with parameter a. Considering the

average durations of the preventive and corrective maintenance actions a

A simple all optical fiber sensor based on multimode interference (MMI) for chemical liquids sensing was designed and fabricated. A segment of coreless fiber (CF) was spliced between two single mode fibers to buildup single mode-coreless-single mode (SCS) structure. Broadband source and optical signal analyzer were connected to the ends of SCS structure. De-ionized water, acetone, and n-hexane were used to test the performance of the sensor. Two influence factors on the sensitivity namely the length and the diameter of the CF were investigated. The obtained maximum sensitivity was at n-hexane at 340.89 nm/RIU (at a wavelength resolution of the optical spectrum analyzer of 0.02 nm) when the diameter of the CF reduced from 125 μm to 60 μ

هدف البحث الى تعرف :

1- مستوى الثقافة التنظيمية لرؤساء الأقسام العلمية في كليات جامعة بغداد.

2- الأهمية النسبية لأبعاد الثقافة التنظيمية لرؤساء الاقسام العلمية  في كليات جامعة بغداد.

بلغت العينة (380) تدريسي وتدريسية من الأقسام العلمية في كليات جامعة بغداد المتمثلة بـ (كلية الهندسة، كلية العلوم، كلية الإعلام، وكلية التربية للبنات)، اعتمدت الاستبانة أداة لتحقيق أه

The study aims to introduce at the difficulties in which delay the using of the internet In the educational process – learning , Study was conducted on a sample of students in the College of Education for Girls and the effects of variables : possession of computer , availability of the internet service , and the level of parents on these difficulties ,  Used for this purpose, a total sample size (400) students, distributed Departments . Results showed that the most important difficulties in which delay using of internet were : Lack of knowledge of internet availability , Lack of knowledge of the aim of using this service , and the students satisfaction that the disadvantages is more than the advantages of

 مشكلة البحث:

تعد مناهج كليات التربية العمود الفقري لإعداد مدرسين تربويين تقع على عاتقهم مهمة تربية وتعليم الجيل الذي سيتحمل مسؤولية بناء المجتمع وتطويره من خلال بناء وإعداد الأفراد في العديد من المجالات. ولما كان التغيير والتطوير المستمرين هما من السمات المميزة للعصر الذي نعيش فيه لذا تتطلب العملية التربوية مراجعة مستمرة لمناهجها بغية تقويمها وتطويرها بما يتناسب ومت

Image pattern classification is considered a significant step for image and video processing.Although various image pattern algorithms have been proposed so far that achieved adequate classification,achieving higher accuracy while reducing the computation time remains challenging to date. A robust imagepattern classification method is essential to obtain the desired accuracy. This method can be accuratelyclassify image blocks into plain, edge, and texture (PET) using an efficient feature extraction mechanism.Moreover, to date, most of the existing studies are focused on evaluating their methods based on specificorthogonal moments, which limits the understanding of their potential application to various DiscreteOrthogonal Moments (DOMs). The

Botnet detection develops a challenging problem in numerous fields such as order, cybersecurity, law, finance, healthcare, and so on. The botnet signifies the group of co-operated Internet connected devices controlled by cyber criminals for starting co-ordinated attacks and applying various malicious events. While the botnet is seamlessly dynamic with developing counter-measures projected by both network and host-based detection techniques, the convention techniques are failed to attain sufficient safety to botnet threats. Thus, machine learning approaches are established for detecting and classifying botnets for cybersecurity. This article presents a novel dragonfly algorithm with multi-class support vector machines enabled botnet

Magnetic Resonance Imaging (MRI) uses magnetization and radio waves, rather than x-rays to make very detailed, cross- sectional pictures of the brain. In this work we are going to explain some procedures belongs contrast and brightness improvement which is very important in the improvement the image quality such as the manipulation with the image histogram. Its has been explained in this worked the histogram shrink i.e. reducing the size of the gray level gives a dim low contrast picture is produced, where, the histogram stretching of the gray level was distributed on a wide scale but there is no increase in the number of pixels in the bright region. The histogram equalization has also been discuss together with its effects of the improveme