Notes on the use of RTP for shared workspace applications

The Real-time Transport Protocol, RTP, has become the dominant protocol for streaming audio and video in IP-based environments. A number of proposals have been made which attempt to build on this success and apply RTP for shared workspace applications. We discuss the needs of such applications and the features provided by RTP, with an aim to showing why RTP is not appropriate for such uses

Using Architecture Models to Design Adaptive Socio-Technical Systems

An architecture framework is used to capture the overall design and structure of a complex system. The Human Viewpoint was developed to augment existing architectural frameworks with additional information relevant to the human component in the system. The Human View models collect and organize social parameters in order to understand the way that humans interact with other elements of the system; the Human View models define the socio-technological boundaries of the system. Analyses performed with the architectural data provide information regarding the congruence, or fit of the human and the system. For example, different key thread analyses identify problematic paths involving human level activities and their intersection with technology. Additionally, node analyses are performed to ensure the flexibility of the human system by evaluating the alignment of roles, tasks, and the impact of constraints. This results in a transition graph for the human system providing paths for adaptation, i.e., the lattice can be used to re-align roles and tasks to maintain overall process performance due to changes in available technology or personnel. By leveraging the architectural models, the human system is designed to be adaptable to its anticipated operating environment. © 2013 The Authors

A Model to Evaluate the Effect of Organizational Adaptation

When an organization’s output declines due to either internal changes or changes in its external environment, it needs to adapt. In order to evaluate the effectiveness of different adaptation strategies on organizational per- formance, an organizational model composed of individual models of a five stage interacting decision maker was designed using an object oriented design approach and implemented as a Colored Petri net. The concept of entropy is used to calculate the total activity value, a surrogate for decision maker workload, based on the functional partition and the adaptation strategy being implemented. The individual decision maker’s total activity is monitored, as overloaded decision makers constrain organizational performance. A virtual experiment was conducted; organizations implementing local and global adaptation strategies were compared to a control organization with no adaptation. The level of tolerance of the organization, the workload limit based on the concept of the bounded rationality constraint, was used to determined when a decision maker was overloaded: the limiting effect of theworkload on performance. The timeliness of the organization’s responsewas used in order to evaluate organizational output as a function of adaptation strategy

A Task Process Pre-Experimental Model

The Adaptive Architectures for Command and Control (A2C2) program is a multidisciplinary program that employs a scientific basis for designing and analyzing adaptive and reconfigurable organizational structures at the Joint Task Force level. As part of its unique model-driven experimentation method, a pre-experimental model is created to support the formulation of hypotheses, the determination of key variables and parameter values, and the prediction of organizational performance. The pre-experimental model is used to explore the parameters of the experimental design in order to determine the appropriate region to conduct officer-in-the-loop experiments at the Naval Postgraduate School. A pre-experimental model based on the task process was created for an upcoming A2C2 subject experiment, which will examine the congruence between organizational structure and mission requirements. The pre-experimental model is a dynamic model created with Colored Petri nets, which can represent the changes in the task environment over time by implementing the stages of the tasks (i.e., detection, identification, attack, destroy, and disappear). The simulator used in the subject experiments, Distributed Dynamic Decision-Making (DDD), records timing information over the life of each task. Therefore, timing information regarding the tasks can be extracted from the output files of the trial experimental runs and included in the model before the final experimental simulations. In this way the model can be validated at the pre-experimental stage

Incorporating Heterogeneity in Command Center Interactions

One of the many complexities of multinational coalition operations stems from differences in culture, military procedures, and command and control processes between the cooperating command centers. These differences can influence the interactions between decision makers of different command centers and can affect the outcome of the coalition operation. A coalition model, composed of individual models of the five-stage interacting decision maker model, was used in a virtual experiment. The subjective parameters included in the decision maker model can be any attribute that characterizes the heterogeneity of the decision makers. In this case, the parameters of power distance and uncertainty avoidance were used, two of Hofstede\u27s (1991) cultural dimensions. The accuracy and timeliness of the coalition\u27s response was used to evaluate its performance as a function of heterogeneity. Including the presence of heterogeneity in the coalition model, through the use of subjective parameters, is the first step in formalizing the process for developing adaptive coalition architectures

Modeling and Evaluating Role and Team Work Processes Using the Improved Performance Research and Integration Tool

The Human View architecture was designed to capture the human requirements of a system and to answer questions about the interactions between humans and systems. Data captured in the Human View can be used to populate a simulation model to evaluate the performance of the humans interacting in a work process. The work process model can be used to investigate different types of human system analyses, at both the role and team levels, and to identify the appropriate metrics to evaluate the results. This study examined individual role performance using the metrics readily available in the simulation tool, and then augmented these with calculated metrics in order to add additional insights to the simulation output. The second part of the study investigated the use of internal indicators to identify different aspects of team interactions. These indicators enable the work process model to be useful for evaluating team processes, and can aid in the understanding of the impact of the communication and coordination functions on crew performance

The Effectiveness of Visualization Techniques for Supporting Decision-Making

Although visualization is beneficial for evaluating and communicating data, the efficiency of various visualization approaches for different data types is not always evident. This research aims to address this issue by investigating the usefulness of several visualization techniques for various data kinds, including continuous, categorical, and time-series data. The qualitative appraisal of each technique\u27s strengths, weaknesses, and interpretation of the dataset is investigated. The research questions include: which visualization approaches perform best for different data types, and what factors impact their usefulness? The absence of clear directions for both researchers and practitioners on how to identify the most effective visualization approach for a specific data type poses a significant research challenge. Our findings will help both professionals and researchers determine the most successful visualization approach for different data types, as well as identify topics for future study in the field of data visualization

A Human View Model for Socio-Technical Interactions

The Human View was developed as an additional architectural viewpoint to focus on the human part of a system. The Human View can be used to collect and organize data in order to understand how human operators interact and impact the other elements of a system. This framework can also be used to develop a model to describe how humans interact with each other in network enabled systems. These socio-technical interactions form the foundation of the emerging area of Human Interoperability. Human Interoperability strives to understand the relationships required between human operators that impact collaboration across networked environments, including the effect of belonging to different organizations. By applying organizational relationship concepts from network theory to the Human View elements, and aligning these relationships with a model developed to identify layers of coalition interoperability, the conditions for different levels for Human Interoperability for network enabled systems can be identified. These requirements can then be captured in the Human View products to improve the overall network enabled system