Functional brain magnetic resonance imaging is a method of indirectly imaging brain activity by measuring blood oxygen level dependency signals that change depending on the degree of cerebral blood flow and blood oxygenation. The spatial and temporal resolution of the data is relatively high, so it is being widely used for brain function diagnosis. However, the detailed description of the acquisition principle and acquisition process of functional brain magnetic resonance imaging has been lacking so far. Therefore, in this paper, we introduce the overview of functional brain magnetic resonance imaging and the image acquisition principle and process.

Interest in functional magnetic resonance imaging (fMRI) has been increased in the field of brain function diagnosis. While fMRI has the advantage of having the highest spatial resolution of data and repeatable measurement non-invasively, it is an analytical technique that has limitations in diagnosing the brain function of a subject with reduced brain function. However, in recent years, various studies on basic brain function activation networks have been actively conducted due to the implementation of the ultra-high-speed image measurement method and the systematic supplementation according to the increase in the stability of the system. Therefore, the clinical application of fMRI currently being used and its future direction will be introduced.

Recently, functional magnetic resonance imaging (fMRI) has been usefully used for brain function evaluation and early diagnosis for patients with dementia. fMRI has several advantages, as is a non-invasive technique without radiational hazard and thus can be repeated many times for clinical trials during a longitudinal study. It has relatively high spatial and reasonable temporal resolution and can be acquired in the same session as structural MRI. In the future, fMRI study combined with various clinical data or genetic information such as the association of APOE 4 gene with cognitive function in the Alzheimer’s disease will outstandingly improve early detection and diagnostic accuracy of diseases for patients with dementia.

The angular dependence of ferromagnetic resonance signal showed single resonance mode (H_r) at near in-plane (θ_H ≈ 0), and dual resonance modes (H_r1 < H_r2) at near normal to plane (θ_H ≈ 90°) in NiFe(100 nm)/CoFe(5 nm) thin film, respectively. The single mode H_r was due to effective magnetic properties by the ferromagnetic exchange coupled NiFe/CoFe bilayers. The H_r1 of dual mode was same as the ferromagnetic resonance field of the NiFe single layer, and H_r2 of dual mode was explained by the ferromagnetic exchange coupling effect.

The number of devices using motors is increasing worldwide, and interest in permanent magnets, which are essential components of permanent magnet type synchronous motors with advantages of wide operating range and high power density, is increasing. In particular, rare-earth permanent magnets with high residual induction are used in various fields such as automobile driving motors , for example, EPS motors. However, due to the limited area in which rare earth elements exist, various problems such as supply-demand imbalance and price surges may occur. In response to this, various types of motors that do not use rare earth elements have been developed. In this paper, the characteristics of various types considering the magnetization process after assembly of the concentrated flux synchronous motor are reviewed, and through this, the design direction of the motor is suggested.