Page 64 - ITU Journal - ICT Discoveries - Volume 1, No. 2, December 2018 - Second special issue on Data for Good

ITU JOURNAL: ICT Discoveries, Vol. 1(2), December 2018

3. PROPOSED PROCEDURAL METADATA microdata and provides the composable
FOR SEMANTIC WEB OF THINGS knowledge to make decisions and perform tasks by
expressing the procedural relations among data
In WoT, devices and data should be properly elements, devices, and systems in granular scales.
managed and engaged by relations and procedures. As procedural metadata is designed to work based
However, the data models and ontologies with on tag data rather than the entire raw data, it has
conventional metadata have shortcomings to advantages to processing time and complexity.
convey common descriptions on procedures Consequently, procedural metadata facilitates data,
among data elements, devices, and systems. devices, and systems to be fully or partially
Accordingly, this paper presents a concept of a new composed efficiently. As described in Fig. 2, a set of
type of metadata, so-called procedural metadata. procedural metadata can be composed as a part of
The goal of procedural metadata is to provide the data, devices, and systems for complex decision
common descriptions on composable procedures making and performing tasks.
of not only individual devices but also smart
systems as a whole based on existing data models Moreover, as a form of metadata, procedural
and ontologies. With procedural metadata, a device metadata can be not only internally inherent in but
or a system can make decisions and perform tasks also externally accompanied with data and devices.
automatically by cooperating with heterogeneous Therefore, the concept of procedural metadata can
devices and systems. Since procedural metadata be easily integrated on the top of the previous and
helps different types of data, devices, and systems ongoing work without much overhead. For an
to collaborate as long as they support micro- example, the concept of procedural metadata can
formatted metatag structures, it facilitates a high- be integrated with W3C’s TD as shown in Fig. 3. In
level of interoperability in WoT. this case, procedural metadata can be externally
stored and managed in a repository just like TD,
3.1 Concept of procedural metadata and the procedural metadata can be utilized by the
WoT Scripting API as needed.
In this paper, smart systems indicate IoT
environments consisting of one or more connected 3.2 Principle of procedural metadata
devices. Applicable data models and ontologies are
not restricted to one type of solution, thus they are In order to not only support interoperability but
not specified in this paper. It is assumed that the also manage procedural metadata efficiently and
common descriptions on the data and device level accessibly, there should be basic principles in
are accomplished based on previous and ongoing generation, organization, and utilization of
works, for example, W3C’s TD and SSN. Instead, procedural metadata. Some underlying principles
procedural metadata aims to achieve a higher level are provided as follows:
of interoperability, with common descriptions on – Procedural metadata is not a mandatory part
procedures. Heterogeneous types of data, devices, of data, devices, and systems, but it is op-
and systems can engage interoperably and support tional.
automation by composing a set of procedures – Procedural metadata should not affect data’s
described in granular components of data, devices, original formats, models, vocabularies, on-
and systems.
tologies, etc.
Procedural metadata is a script type of data that – The inputs and outputs of each procedural
describes event, condition, and action-based metadata should be clarified so that a set of
procedures of smart systems. It describes procedural metadata can be composed
composable logic, functions, and workflows among through output-input connections.
data, devices, and systems, thus they can – The inputs and outputs of procedural
interoperably and automatically engage together metadata need to be a set of IoT resource or
to make decisions and perform tasks. To empower data and a sort of action needed to be taken,
semantics, WoT data is often micro-formated and including actuating, sensing, data managing,
structured in parsable forms so that the data can etc.
be expressed and managed with their relationships – As an executable script-type data, procedural
and properties in granular scales as described in metadata needs to be described based on
Fig. 1. The procedural metadata utilizes the sets of conditions and actions of IoT re-

42 © International Telecommunication Union, 2018