We explore the impact of using different modeling paradigms on the outcome of simulation studies. Modeling paradigms, once implemented, follow different computational rules regarding how calculations are made and are sequenced during runtime. To test the effects of computational differences on a simulation's outcomes, we implement a simple queuing system as a Discrete Event Simulation model, a System Dynamics model, an Agent-based Model, and a Multi-paradigm Model. Our findings show that paradigm selection does play a role in the generation of outcomes, as the System Dynamics model produces a significantly different set of outcomes than the other models for the selected output variables. This paper serves as a first step in examining how the selection of a paradigm affects the outcome of the simulation.
In this article, we present ConceVE, an approach for designing and validating models before they are implemented in a computer simulation. The approach relies on (1) domain-specific languages for model specification, (2) the Alloy Specification Language and its constraint solving analysis capabilities for exploring the state space of the model dynamically, and (3) supporting visualization tools to relay the results of the analysis to the user. We show that our approach is applicable with generic languages such as the Web Ontology Language as well as special XML-based languages such as the Coalition Battle Management Language.
In this paper, we propose an approach to formally verify and rigorously validate a simulation system against the specification of the real system. We implement the approach in a verification and validation calculator tool that takes as input a set of statements that capture the requirements, internal conditions of the system and expected outputs of the real system and produces as output whether the simulation satisfies the requirements, faithfully represents the internal conditions of the system and produces the expected outputs. We provide a use case to show how subject matter experts can apply the tool.
AbstractA large number of leadership theories focus on understanding the concept of leadership from an ontological perspective by focusing on the leader, the leader/follower relationship, or the concept of leadership itself. Others focus on axiological premises, referring to the moral values of the leader/manager under which he or she leads and makes decisions. However, one may argue that they tend to be too focused on finding intricacies that they forgo a comprehensive perspective. This paper focuses on the nature of the leader by considering his/her worldviews as driven by four philosophical dimensions: epistemological, ontological, teleological, and axiological. It is argued that these dimensions need to be considered simultaneously in order to present a holistic perspective of the nature of leaders. The proper balance of these dimensions are also contingent on the situation faced by the leader/manager at a given moment, which may make his or her leadership style appropriate or inappropriate given a situation. This appropriateness is also addressed in the paper and the concepts of wicked problems and complex situations are presented to establish a context. These arguments lead to the formulation of five propositions that provide an understanding on the underlying foundations of leaders.
This paper describes a SoSE environment designed to facilitate the problem-solving process of complex situations. Complex situations can be seen as the behavior of a system of systems that needs to be transformed to a desirable state. This is addressed by exploring the impact and implications of systems analysis and design within a social/group setting where many stakeholders with issues, concerns and independent perspectives develop solutions sets. To achieve this objective, the environment was designed to facilitate, in a social setting; (1) assessment of the complexity of the situation, (2) structure of possible frameworks from which the situation can be dealt with and (3) Take the situation to a desirable state.
Hybrid Simulation (HS) is not new. However there is contention in academic discourse as to what qualifies as HS? Is there a distinction between multi-method, multi-paradigm and HS? How do we integrate methods from disciplines like OR and computer science that contribute to the success of a M&S study? How do we validate a hybrid model when the whole (the combined model) is greater than the sum of its parts (the individual models)? Most dynamic simulations have a notion of time, how do we realize a unified representation of simulation time across methodologies, techniques and packages, and how do we prevent causality during inter-model message exchange? These are but some of the questions which we found to be asking ourselves frequently, and this panel paper provided a good opportunity to stimulate a discussion along these lines and to open it up to the M&S community.
The academic achievement gap is a persistent phenomenon in U.S. education system despite a long history of efforts and billions of dollars spent to correct it. Literature abounds with theories about why the gap exist, such as: student self-perception, parent involvement, teacher quality, and others. Model based approaches have been used to understand various aspects of the phenomenon. However, no models were identified that consider a comprehensive set of theories, and is specifically designed to investigate potential policies and strategies for reducing the gap. We build such a model using a methodology that includes: a) Modeling and Simulation-System Development Framework (MS-SDF); b) Systems Modeling Language (SysML); and c) a Systems Dynamics approach. Preliminary findings indicate that concepts from prevailing theories about the achievement gap can be accurately represented in a single system dynamics model. We also identify key stakeholders, functions, and variables affecting the achievement gap.
