Abstract: An electronic device and a controlling method thereof are provided. The electronic device includes a memory and a processor configured to obtain importance data representing an importance of each of a plurality of words included in the text data using text data related to a plurality of items written by a plurality of users, obtain a topic model representing a relationship between a topic and a word by applying a topic modelling algorithm to the obtained importance data, obtain preference data representing preference of each of the plurality of users for the topic and relationship data representing a relationship between the plurality of items and the topic, based on the obtained topic model, and train a recommendation model to output result data including an estimated preference for the plurality of items of the plurality of users, based on the preference data and the relationship data.

Abstract: A system for measuring magnetic field gradients comprising a multi-bay support structure with a series of raised contact shoulders separated from each other by voids. An optical fiber is spaced along the length of the multi-cell support structure and traverses all the raised contact points and voids. The optical fiber has a plurality of Fiber Bragg gratings (FBGs) spaced lengthwise, each FBG suspended in a void. In addition, a plurality of ferromagnetic members are strung onto the optical fiber, each suspended in a void. Magnetic field gradients act on the ferromagnetic member to create localized tension in the optical fiber. The FBG's refractive indices are monitored, tension is calculated therefrom, and the tension is correlated to the magnetic field gradient. This greatly simplifies mechanical, optical, electronic and computational complexity and is bay suited for any FOSS array for measuring magnetic fields using many dense measurement points.

Abstract: A method and system for rendering the quaternion shape and orientation of a three-dimensional structure. The proposed system and method keeps track of twist/roll angles and updates its effect on pitch and yaw orientations. The system relies on a single or multi-core optical fiber or multi-fiber bundle containing fiber Bragg grating sensors (FBGs) arrayed in rosettes at 45° deltas and spaced at uniform intervals along the entire length of the structure to be monitored. A tunable laser is used to interrogate the sensors using optical frequency domain reflectometry (OFDR), which detects shifts in the wavelength reflected by the sensors in response to strain on the fibers. Each sensor is continuously queried by software which determines the strain magnitude (?L/L) for each fiber at a given triplet. Given these measured strain values, the software implements a novel quaternion approach to rendering the 3D shape of the fiber including twist.

Abstract: Various embodiments may provide a strain-sensing apparatus configured to be attached to a micrometeoroid and orbital debris (MMOD) shielding layer and data collection equipment in communication with the strain-sensing apparatus configured to detect an occurrence, a time, a location, and/or a severity of a MMOD strike on the MMOD shielding layer. The various embodiments may enable detection and/or location of potentially harmful MMOD strikes on both human occupied and unmanned spacecraft.

Abstract: Various embodiments may provide a strain-sensing apparatus configured to be attached to a micrometeoroid and orbital debris (MMOD) shielding layer and data collection equipment in communication with the strain-sensing apparatus configured to detect an occurrence, a time, a location, and/or a severity of a MMOD strike on the MMOD shielding layer. The various embodiments may enable detection and/or location of potentially harmful MMOD strikes on both human occupied and unmanned spacecraft.