Makoto Kayashima

Virtual machine placement algorithm for virtualized desktop infrastructure

Finding optimal placement of virtual machines on numerous physical servers is one kind of bin-packing problem, which is known as an NP-hard. We propose the use of a heuristic algorithm to solve this problem where the virtual machines play the roles of personal desktops. As we have found out that the changes in the amount of hardware resources required by a desktop often repeat a certain pattern, in the proposed algorithm, we uses the correlation between the patterns to find the group of desktops that are most suitable for sharing the same physical server. Simulation results show that the proposed algorithm can be used to reduce the number of physical servers required for hosting a certain number of virtual desktops.

A Proposal of Security Requirements Definition Methodology in Connected Car Systems by CVSS V3

The use of connected cars has been spreading recently. Security for connected cars is very important because an attacker can access connected cars remotely. Security requirements defined based on risk assessment are necessary to protect connected cars from attackers. However, the conventional risk assessment technique mostly depends on the evaluators security knowledge. Therefore, we propose a security requirement definition methodology for connected car systems. The proposed methodology is based on the security requirements definition methodology in IoT (Internet of Things) systems, which consists of four processes: modelization of target system, definition of security problems, consideration of security requirements, and decision of security function components. We applied the methodology in IoT systems to connected car systems. In particular, the risk assessment, which is executed to define security problems, uses CVSS v3 which was released in 2015. We can assess the risk of connected car systems objectively by using the base metrics of CVSS v3.