Abstract: A method for determining airborne particulate density, the method including: locating or positioning at least one dark target within a local environment and scanning the local environment using an image capturing component of a user equipment device; constructing a geometric three-dimensional model of the local environment; determining pertinent features within the local environment based on the geometric three-dimensional model; focusing the image capturing component of the user equipment device on the dark target, the user equipment device having quantified location and orientation within the local environment; determining an instantaneous light intensity of the local environment and capturing at least one image of the dark target using the image capturing component of the user equipment device; and analyzing the at least one image in correspondence with the pertinent features, the instantaneous light intensity, and the dark target, and determining therefrom an airborne particulate density in the local envi

Abstract: Methods and systems are disclosed which determine a location context of a mobile device such as a smartphone. The method may include the following steps: collecting sensor specific data from sensors of the mobile device, applying the sensor specific data to a decision function, and determining, as an output of the decision function, a location context of the mobile device. Also disclosed is a non-transitory computer readable medium containing instructions that when executed causes one or more processors of the mobile device to perform the disclosed method.

Abstract: In general, the subject matter described in this disclosure can be embodied in methods, systems, and computer-readable devices. An audio processing device plays a source audio signal, including causing the source audio signal to be audibly output by an electroacoustic transducer of a user earpiece. The audio processing device records, while playing the source audio signal, a recorded audio signal using the electroacoustic transducer. The audio processing device identifies one or more parameters that indicate how properties of the user earpiece affect playing of the source audio signal, at least one of the parameters being temperature dependent. The audio processing device determines a temperature value estimated to cause the source audio signal that was played by the audio processing device to result in the recorded audio signal, accounting for changes to the source audio signal that occur due to the one or more parameters.

Abstract: A method for determining airborne particulate density, the method including: locating or positioning at least one dark target within a local environment and scanning the local environment using an image capturing component of a user equipment device; constructing a geometric three-dimensional model of the local environment; determining pertinent features within the local environment based on the geometric three-dimensional model; focusing the image capturing component of the user equipment device on the dark target, the user equipment device having quantified location and orientation within the local environment; determining an instantaneous light intensity of the local environment and capturing at least one image of the dark target using the image capturing component of the user equipment device; and analyzing the at least one image in correspondence with the pertinent features, the instantaneous light intensity, and the dark target, and determining therefrom an airborne particulate density in the local envi