# An Ontology for Spatio-Temporal Media Management and an Interactive Application
## 2 Related Works
### Related Ontologies and Studies  
The Music Ontology [18; 19] is a unified framework that describes music-related information. The Music Ontology is a combination of the Timeline Ontology [20], Event Ontology [21], and International Federation of Libraries (IFLA) Functional Requirements for Bibliographic Records (FRBR) Ontology [22], Friend of a Friend (FOAF) [23], etc. It is based on existing ontologies, can describe artist names and song titles and represents each stage from composition to performance, recording, and release. Furthermore, the Music Ontology does not represent technical aspects of the music production flow, unlike the Studio Ontology [24] represents. The Studio Ontology enables the description of a series of audio recording and editing flows, including microphone placement, wiring connections between devices, mixing, and signal processing. In particular, a more detailed description of audio effects has been extended and defined as the Audio Effect Ontology [25; 26].  
Meanwhile, the following are studies on building an ontology for instrument classification. Implementation experiments were conducted using a prototype ontology based on two different instrument classification methods [27]. A study was performed to identify and group instruments based on their timbre characteristics and to generate a hierarchical instrument ontology automatically [28]. Several ontologies work with the Music Ontology. The Audio Features Ontology [29; 30] provides a description of the computational workflow for audio feature extraction and a representation structure for various feature data formats.  
Figure 1: Overview of digital media production flow and scope of the SDM Ontology description.  
Another highly abstract ontology is the Audio Commons Ontology [31; 32]. The acoustics, musical compositions, and synthetic sounds used by various online services are stored in repositories on the Web. The Audio Commons Ontology was designed to facilitate the repository integration of audio content and access to the repository from client applications. The computing device network that handles data valid for music is called the Internet of the Musical Things (IoMusT), analogous to the Internet of Things (IoT). The Internet of Musical Things Ontology [33; 34] describes the IoMusT ecosystem.  
In addition, standards and related studies for general spatio-temporal media and data are summarised below. MPEG-7 [35] ([[https://mpeg.chiariglione.org/standards/mpeg-7](https://mpeg.chiariglione.org/standards/mpeg-7)]([https://mpeg.chiariglione.org/standards/mpeg-7](https://mpeg.chiariglione.org/standards/mpeg-7)) (accessed on 1 June 2023)) is a metadata representation standard for describing semantics information of multimedia content. MPEG-7 uses the Description Definition Language (DDL) to describe semantic information. DDL can represent a wide range of semantic information ranging from media data and the content expressed in media data to related contexts. The Multimedia Ontology (MMO) is an ontology that effectively solves the problem of the \"semantic gap\" between the perceptible media world and the advanced conceptual world [36]. The Multimedia Web Ontology Language (MOWL) [37] is an ontology for reasoning about media properties and potential concepts in multimedia applications. The MOWL employs the representation of spatio-temporal relations proposed in [38] to extend the MPEG-7 query language. [PERSON] et al. [39] showed that object motion could be recognized from low-level video information by mapping vocabulary and object motion using an ontology mapping technique. [PERSON] et al. [40] designed and implemented a prototype of an automated spatial reasoning system for geospatial information applications called NEXUS and showed that it could perform a variety of spatio-temporal queries and also explain why it reached the conclusions it did.