Biblio

Gait phase segmentation is the process of identifying the start and end of different phases within a gait cycle. It is essential to many medical applications, such as disease diagnosis or rehabilitation. This work utilizes inertial measurement units (IMUs) mounted on the individual's foot to gather gait information and develops a gait phase segmentation method based on the collected signals. The proposed method utilizes a weighted dynamic time warping (DTW) algorithm to measure the distance between two different gait signals, and a k-nearest neighbors (kNN) algorithm to obtain the gait phase estimates. To reduce the complexity of the DTW-based kNN search, we propose a neural network-based graph embedding scheme that is able to map the IMU signals associated with each gait cycle into a distance-preserving low-dimensional representation while also producing a prediction on the k nearest neighbors of the test signal. Experiments are conducted on self-collected IMU gait signals to demonstrate the effectiveness of the proposed scheme.

The threshold secret sharing technique has been used extensively in cryptography. This technique is used for splitting secrets into shares and distributing the shares in a network to provide protection against attacks and to reduce the possibility of loss of information. In this paper, a new approach is introduced to enhance communication security among the nodes in a network based on the threshold secret sharing technique and traditional symmetric key management. The proposed scheme aims to enhance security of symmetric key distribution in a network. In the proposed scheme, key distribution is online which means key management is conducted whenever a message needs to be communicated. The basic idea is encrypting a message with a key (the secret) at the sender, then splitting the key into shares and sending the shares from different paths to the destination. Furthermore, a Pre-Distributed Shared Key scheme is utilized for more secure transmissions of the secret’s shares. The proposed scheme, with the exception of some offline management by the network controller, is distributed, i.e., the symmetric key setups and the determination of the communication paths is performed in the nodes. This approach enhances communication security among the nodes in a network that operates in hostile environments. The cost and security analyses of the proposed scheme are provided.