Wear-out Aware Scheduling of Mixed-criticality Systems

, M.Sc. Thesis Sharif University of Technology Shaabani Ilani, Abolfazl (Author) ; Miremadi, Ghassem (Supervisor)

Abstract

Using a large number of processing nodes for distributed embedded computer systems, imposes many overhead costs such as increased production cost and communication cost and degradation of system reliability. One option to reduce this overhead is to schedule many applications consisting of several level of criticalities on the same system which has the advantages of high reliability, economical and easy to manage power consumption. In these systems, usually different tasks with different criticality levels simultaneously run on a single processor. On the other hand, due to aggressive factors such as aging, process variation, workload, ambient temperature and other wearing out factors,...

A Task Assignment Method to Reduce Aging in Multi-core Processors

, M.Sc. Thesis Sharif University of Technology Saadatmand, Faezeh Sadat (Author) ; Miremadi, Ghassem (Supervisor)

Abstract

Reducing the size of transistors has dramatically increased the impacts of NBTI, HCI, and EM phenomena in comparison with decade ago. These phenomena are able to have influence on properties of different parts of a chip to make it changed gradually; including threshold voltage of a transistor and electrical conductivity of interconnections. These changes are known as the aging of a transistors that diminish the performance and reliability of a chip. A common reason that plays a significant role in all these phenomena is temperature. The temperature becomes more important when the power density increases per unit area due to decreased size of transistors, which is a trend in multi-core...

Analysis of Contact Geometry Effect on the Slip Amplitude in Fretting Fatigue of a Turbine Blade Root

, M.Sc. Thesis Sharif University of Technology Shirzadi, Saba (Author) ; Adibnazari, Saeed (Supervisor)

Abstract

Turbine blades are exposed to mechanical and thermal stresses due to their operation in critical conditions and get into various damages such as fatigue and wear. These factors reduce the life of the blades and lead to expensive maintenances. As a result, recognizing the type of possible damage helps to increase the life of the blade and to delay the occurrence of failures by taking the necessary actions.The subject of this thesis is to investigate the effect of geometric parameters on the slip amplitude in the root of a turbine blade. In this work, the effect of three parameters of contact area length, contact angle, and coefficient of friction on relative slip amplitude and contact...

An Investigation on Aging of Rubber Compounds Against Acidic Gases

, M.Sc. Thesis Sharif University of Technology Aminizadeh, Pooria (Author) ; Mousavi, Abbas (Supervisor) ; Shojaei, Akbar (Supervisor)

Abstract

Aging of rubber compounds at high temperature and pressure acidic gas is a challenge for using them for a long time. Therefore, in this thesis aging of NBR/PVC compounds against H¬2S and CO2 has been investigated. The main method have been used is Full Factorial Design of Experiment. The parameters have been examined are content of zinc oxide, plasticizer RPO ASTM 290 and antioxidant 4010 NA. The content have been set in tow levels and effect of each have investigated in ambient and 120 degree of centigrad temperature. The results show that the effect of antioxidant 4010 NA on aging of compounds is negative and zinc oxide and plasticizer RPO ASTM 290 are positive