Money is enigmatic. Despite extensive investigation to date, conflicting theories persist regarding its nature. Examples include views that “Money is a physical object,” “Money is an abstract concept,” and “Money is institutional status,” among others. This paper aims to unravel this mystery by engaging in an ontological discourse on the essence of money and constructing a three-layer model that comprises (i) the representation (legitimacy) layer, (ii) the role layer, and (iii) the property layer. In the representation layer, official state-issued objects such as banknotes are examined through the lens of the representation theory. In the role layer, these objects act as monetary role holders, referred to as monetary objects, by playing the monetary role which is inherently social in nature. The three fundamental properties/functions of money—serving as a unit of economic value, being exchangeable with commodities, and capable of being stored—are inherent in monetary role, and hence in monetary objects. However, these properties/functions remain latent until they are possessed by agents. The property layer elucidates that money is a contingent property of the owner of monetary objects, who can engage in economic activities by harnessing/actualizing these three properties/functions. In summary, our ontological theory of money posits Money as a property, Monetary objects holding the Monetary role, whose player is the Legitimate representing thing issued by the authority. For instance, a freshly minted 20 Euro banknote is a legitimate representing thing, transitioning into a monetary object upon holding the monetary role within the economic context. Its institutional/causal power becomes operative upon ownership by an agent. Our theory adopts a monistic perspective rather than a dualistic one, facilitated by the above nuanced distinctions made among entities pertaining to “money.” Discussion about how our theory works for resolving some of the current issues is presented together with a justification for the observation that money virtually has use value in addition to exchange value.

We introduce and formalize the key elements of a recent approach [1] to function definition that covers both biological and artefact functions. The paper concentrates on the steps from informal definitions to formal expressions and aims to show how to develop an ontological module for generic function representation. This part is done assuming the YAMATO ontology as background system. The second goal of the paper discusses how the module could be adapted to other foundational ontologies. In this part, we first point out the ontological assumptions on which the module relies and then discuss problems in reformulating them in other systems. This step is needed to verify whether and how the function module can be meaningfully used in other ontologies. We exemplify this case by discussing BFO and DOLCE, and by formalizing the module in the latter ontology.

Both natural objects and artifacts have been studied from a variety of perspectives by the different sciences. One issue that has so far resisted philosophical and ontological investigations is the definition of a general notion of function capable of making sense of the functions attributed to natural objects, such as biological organisms, as well as of the functions attributed to artifacts, such as (designed) tools.

The purpose of this paper is to characterize some definitions of function in engineering and philosophy from an engineering point of view. To do this, this paper firstly discusses some fundamental kinds of function based on ontological distinctions. Next, based on them, we characterize our definition with justifications from the engineering view and present an ontological model of artifact function along the product life-cycle. Then, we try to characterize a philosophical definition of biological organs using the model. Next, we discuss function of a non-biological (non-organic) natural thing. Lastly, we characterize functions of an artifact, a biological organ and a non-biological natural thing based on another ontological model along the evolution of creatures.

Growth in the mobile services industry has remarkably increased in the number of mobile services provided, and present methods of service provision have proven insufficient to guide users efficiently to the services they need. To solve this problem, a task-oriented menu, which enables users to search for services by "what they want to do" instead of by "name of category", has been proposed. Construction of such a task-oriented menu is based on a task ontology modeling method which supports the description of user activity such as task execution and the solving of obstacles encountered during the task. This paper discusses a task ontology-based modeling method which supports the description of users' activity and related knowledge such as how to solve problems that occurs on the users and prevention method for accidents. Models described by our method contribute to checking, designing and improving mobile Internet services.