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We find new examples of harmaonic maps between compact Riemannian manifolds. A section of a Riemannian fibration is called harmonic if it is harmonic as a map from the base manifold into the total space. When the fibres are totally geodesic, the Euler-Lagrange equation for such sections is formulated. In the case of distributions, which are sections of a Grassmannian bundle, this formula is described in terms of the geometry of base manifolds. Examples of harmonic distributions are constructed when the base manifolds are homogeneous spaces and the integral submanifolds are totally geodesic. In particular, we show all the generalized Hopf-fibrations define harmonic maps into the Grassmannian bundles with the standard metric. Introduction.Let M and N be complete Riemannian manifolds. Assume M is compact. A smooth map f : M → N is called harmonic if it is a critical point of the energy functional. If N has non-positive curvature, then there exists a harmonic map in each homotopy class. However, if N has positive curvature, this is no longer true and it always has been meaningful to find examples of harmonic map between compact manifolds with nonnegative curvature. In this paper, we produce some new type of harmonic maps between compact Riemannian manifolds.We consider the case when N is a fibre bundle over M and f : M → N is a smooth map which happens to be a section of this fibration. If N is a vector bundle over M with a connection type metric, then f is a harmonic map if and only if it is a parallel section. We will consider the case when the fibres are totally geodesic compact submanifolds, and hence N is also a compact Riemannian manifold. In particular, if N is a Grassmannian bundle associated to the orthogonal bundle O(M), then the map f defines a smooth distribution on M. A distribution on a Riemannian manifold M will be called harmonic if it is harmonic as a map from M into the total space of the Grassmannian bundle over M. We will find the Euler-Lagrange equation of a harmonic map f in a general setting and find a solution to this equation to construct examples of harmonic distributions.The definition of harmonic distributions, or harmonic sections in general, is used by other authors [7], [8], [9], [13] in a similar context but for a different concept. They call a section harmonic if its vertical energy is stationary with respect to vertical variations. If one is looking for a better section, this notion of harmonic section makes more sense. A variation

This study suggests that a G-LOC detecting and warning system may be a customized, real-time countermeasure by improving the accuracy of detecting G-LOC.Kim S, Cho T, Lee Y, Koo H, Choi B, Kim D. G-LOC warning algorithms based on EMG features of the gastrocnemius muscle. Aerosp Med Hum Perform. 2017; 88(8):737-742.

Pilots are required to have the ability to evaluate their own physical and psychological status to operate high performance aircrafts effectively. Existing studies have lacked consideration of applying bio signal of pilots in real time flight situation. The purpose of this study is to develop a wearable bio signal monitoring system that can measure the condition of pilots under an extreme flight environment to ensure flight safety. The wearable bio signal monitoring system consists of an algorithm for evaluating pilots' physiological stability, algorithms for detecting Gravity-induced Loss of Consciousness (G-LOC) prognosis, pilots' interaction module, and pilots' context awareness platform. The algorithm for evaluating pilots' physiological stability uses psychomotor cognitive test (PCT) and heart rate variability (HRV) to measure pilots' mission performance before flight. The algorithms for detecting G-LOC prognosis utilizes electromyogram (EMG) to generate warning signal during flight. The pilots' interaction module was developed for pilots to operate the system efficiently under flight environment. The pilots' context awareness platform was designed for the system to process multiple sensor signals in real time. This wearable bio signal monitoring system is expected to enhance flight safety and mission performance of pilots.

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