Asymptotic Analysis for Systems with Deferred Abandonment

This short paper concerns the analysis of the M/M/k queueing system with customer abandonment. In this system, service managers provide a finite buffer space, which is a waiting area that prevents customers from abandoning the system. Abandonment of the system can occur from reneging (exiting from the queue while waiting), and/or balking (leaving the system without waiting). We derive an analytical expression to represent the impact of the buffer space capacity on the delay probability and the abandonment probability for a system with deferred abandonment. The result indicates the provision of the buffer space in a large system could only increase the delay probability while the abandonment probability remains unchanged. Despite the benevolent intentions of service managers, providing a buffer space may exacerbate the performance of larger systems.

Queueing Systems with Random Volume Customers and their Performance Characteristics

In the paper, we consider non-classical queueing systems with non-homogeneous customers. The non-homogeneity we treat in the following sense: in systems under consideration, we characterize each customer by random capacity (volume) that can have an influence on his service time. We analyze a stochastic process having the sense of the total volume of all customers present in the system at given time instant. Such analysis for different queueing systems with unlimited or limited total volume can be used in designing of nodes of computer and communication networks while determining their buffer space capacity. We discuss basic problems of the theory of these systems and their performance characteristics. We also present some examples and results for systems with random volume customers

GEOPOLITICS OF IRAN ACCORDING TO THE THEORY OF GEOGRAPHICAL BUFFER SPACES

With the occupation of India by one of the global powers namely Britain (1770), and its territorial expansion toward the West and Iran’s borders, Russia (the other global power) started to expansionism and move toward Indian Ocean and Iran’s north borders from the first of 19th century (1804-1813/ 1826/1828). Britain from East and South and Russia from North intruded on Iran’s borders, and buffered Iran and Afghanistan in order to not to collide with each other. In the rivalry pattern of buffered states, their geographic spaces should be separate. Low power geographic space is required between the powers. Geopolitical boundaries of these two powers should not contact because in such a case, the possibility of conflict can arise. So, the buffer space takes the form of vacuum space between the buffered powers.The research main question is that what are the nature, functions, characteristics and political behavior of geographic buffer space? Which geographic values and functions cause buffer space act as a buffer space and attract great powers?In this research, a new definition of buffer space is presented, and the process of formation of buffers (the whys and wherefores), functions and characteristics of buffers in two internal and external dimensions are investigated. Then, the validity of the variables is investigated using library and field findings, and is used in the process of evaluation of internal and external experts. The results are analyzed using statistical methods and SPSS. Finally, these variables are evaluated in the context of Iran.The research findings show that the pattern of geopolitical rivalry of great powers has been reflected in Iran’s space in the last two centuries, namely not only foreign relations, but also Iran’s internal political situation are reflections of the pattern of rivalry of great powers resulted from Iran’s buffer situation. The behavior of Iranian politicians and people have been affected by the behavior of buffered powers. This situation has caused some behaviors to be created like xenophobia, lack of trust in politicians, de-utilization etc. The buffer space cannot make decision without considering the interests of buffered states. In the buffer space, all of the political phenomenon are the reflection of buffered space.

Elastic buffer structured Si/C microsphere anodes via polymerization-induced colloid aggregation

The voids and void-holes provide the direct and elastic buffer space to ensure the structural integrity of carbon frameworks.

A Group-Based Buffer Management for SSD

Random writes limit the application of SSDs significantly because of their poor latency and high garbage collection overhead. Traditional page-based and block-based buffer management algorithms cannot achieve both high buffer hit ratio and good destage sequentiality at the same time. In this paper, we propose a hybrid scheme called the group-based buffer management (GBBM). To improve buffer hit ratio and decrease write/erase counts, GBBM divides buffer space into Page Region and Group Region. The frequently accessed data pages are placed at the Page Region, while infrequently accessed random written data are grouped in the Group Region. GBBM has been evaluated extensively through simulations. The write counts of GBBM show an average decrease of 12.7% compared with page-level buffer scheme. Compared with hybrid buffer management such as CBM, GBBM decreases the average write/erase count by 14.3%/12.1%. The write hit ratio of GBBM shows a 4.5% improvement as compared with PAB. The proposed GBBM can significantly reduce the number of write operations while maintaining a relatively high buffer hit ratio.