14010108
conga: A Framework for Adaptive Conducting Gesture Analysis
Designing a conducting gesture analysis system for public spaces poses unique challenges. We present conga, a software framework that enables automatic recognition and interpretation of conducting gestures. conga is able to recognize multiple types of gestures with varying levels of difficulty for the user to perform, from a standard four-beat pattern, to simplified up-down conducting movements, to no pattern at all. conga provides an extendable library of feature detectors linked together into a directed acyclic graph; these graphs represent the various conducting patterns as gesture profiles. At run-time, conga searches for the best profile to match a user's gestures in real-time, and uses a beat prediction algorithm to provide results at the sub-beat level, in addition to output values such as tempo, gesture size, and the gesture's geometric center. Unlike some previous approaches, conga does not need to be trained with sample data before use. Our preliminary user tests show that conga has a beat recognition rate of over 90%. conga is deployed as the gesture recognition system for Maestro!, an interactive conducting exhibit that opened in the Betty Brinn Children's Museum in Milwaukee, USA in March 2006.
2078708
Improving orchestral conducting systems in public spaces: examining the temporal characteristics and conceptual models of conducting gestures
Designing interactive conducting exhibits for public spaces poses unique challenges, primarily because the conceptual model of conducting music varies amongst users. In a user study, we compared how conductors and non-conductors place their beats when conducting to a fixed orchestral recording of Radetzky March, and found significant differences between these two groups. Conductors lead the actual music beat with their gestures by an average of 150 ms, compared to 50 ms for non-conductors; non-conductors also vary their placement of the beat 50% more than conductors. Furthermore, we found differences in how users conceptually mapped their gestures to the music, such as conducting to the musical rhythm rather than to the beat. We are incorporating these results into an upcoming conducting system for public spaces to increase its usability; we believe they also apply to a more general class of musical gestures such as dance.
7551391
The Role of Time in Engineering Computer Music Systems
Discussion of time in interactive computer music systems engineering has been largely limited to data acquisition rates and latency. Since music is an inherently time-based medium, we believe that time plays a more important role in both the usability and implementation of these systems. In this paper, we present a time design space, which we use to expose some of the challenges of developing computer music systems with time-based interaction. We describe and analyze the time-related issues we encountered whilst designing and building a series of interactive music exhibits that fall into this design space. These issues often occur because of the varying and sometimes conflicting conceptual models of time in the three domains of user, application (music), and engineering. We present some of our latest work in conducting gesture interpretation and frameworks for digital audio, which attempt to analyze and address these conflicts in temporal conceptual models.
1549095
Education, entertainment and authenticity: lessons learned from designing an interactive exhibit about medieval music
In this paper we describe the design experience gathered from creating an interactive exhibit about medieval music. This system was designed as an educational exhibit that relies on audio as its only feedback channel. We focused our work on three major goals: educational value, entertainment aspects, and historic authenticity. We present insight into the challenges in designing a system with these goals, and how they could be solved.
7621577
Towards a quantitative analysis of audio scrolling interfaces
We present the results of a user study inspired by previous work in document navigation comparing rate and position control for navigating an audio timeline. Although interfaces for controlling playback speed (rate) are favored over playback position, we found that position control is, on average, 15-19% faster than rate control when searching for targets 90 to 100 seconds away in the audio timeline. Additional studies are being planned to further characterize audio scrolling performance with position and rate controls.
1540671
Bangarama: Creating Music with Headbanging
Bangarama is a music controller using headbanging as the primary interaction metaphor. It consists of a head-mounted tilt sensor and a guitar-shaped controller that does not require complex finger positions. We discuss the specific challenges of designing and building this controller to create a simple, yet responsive and playable instrument, and show how ordinary materials such as plywood, tin foil, and copper wire can be turned into a device that enables a fun, collaborative music-making experience.
9981963
Static Scheduling of Synchronous Data Flow Programs for Digital Signal Processing
Large grain data flow (LGDF) programming is natural and convenient for describing digital signal processing (DSP) systems, but its runtime overhead is costly in real time or cost-sensitive applications. In some situations, designers are not willing to squander computing resources for the sake of programmer convenience. This is particularly true when the target machine is a programmable DSP chip. However, the runtime overhead inherent in most LGDF implementations is not required for most signal processing systems because such systems are mostly synchronous (in the DSP sense). Synchronous data flow (SDF) differs from traditional data flow in that the amount of data produced and consumed by a data flow node is specified a priori for each input and output. This is equivalent to specifying the relative sample rates in signal processing system. This means that the scheduling of SDF nodes need not be done at runtime, but can be done at compile time (statically), so the runtime overhead evaporates. The sample rates can all be different, which is not true of most current data-driven digital signal processing programming methodologies. Synchronous data flow is closely related to computation graphs, a special case of Petri nets. This self-contained paper develops the theory necessary to statically schedule SDF programs on single or multiple processors. A class of static (compile time) scheduling algorithms is proven valid, and specific algorithms are given for scheduling SDF systems onto single or multiple processors.
207225124
A Linear Programming Approach to Discriminant Analysis with a Reserved-Judgment Region
A linear-programming model is proposed for deriving discriminant rules that allow allocation of entities to a reserved-judgment region. The size of the reserved-judgment region, which can be controlled by varying parameters within the model, dictates the level of aggressiveness (cautiousness) of allocating (misallocating) entities to groups. Results of simulation experiments for various configurations of normal and contaminated normal three-group populations are reported for a variety of parameter selections. Results of cross-validation experiments using real data sets are also reported. Both the simulation and cross-validation experiments include comparison with other discriminant analysis techniques. The results demonstrate that the proposed model is useful for deriving discriminant rules that reduce the chances of misclassification, while maintaining a reasonable level of correct classification.
12760368
A Flexible Architecture for Virtual Humans in Networked Collaborative Virtual Environments
Complex virtual human representation provides more natural interaction and communication among participants in networked virtual environments, hence it is expected to increase the sense of being together within the same virtual world. We present a flexible framework for the integration of virtual humans in networked collaborative virtual environments. A modular architecture allows flexible representation and control of the virtual humans, whether they are controlled by a physical user using all sorts of tracking and other devices, or by an intelligent control program turning them into autonomous actors. The modularity of the system allows for fairly easy extensions and integration with new techniques making it interesting also as a testbed for various domains from “classic” VR to psychological experiments. We present results in terms of functionalities, example applications and measurements of performance and network traffic with an increasing number of participants in the simulation
19038002
Computational Experience of an Interior-Point Algorithm in a Parallel Branch-and-Cut Framework
An interior-point algorithm within a branch-and-bound framework for solving nonlinear mixed integer programs is described. In contrast to solving the relaxation to optimality at each tree node, the relaxation is only solved to near-optimality. Analogous to using advanced bases for warmstart solutions in the case of linear MIP, a \dynamic" collection of warmstart vectors is kept. Computational results on various classes of nonlinear mixed integer programs are presented.
36370882
Multi-agent Based Hybrid System for Dynamic Web-Content Adaptation
Context-aware adaptation service is rapidly becoming an important issue. This service overcomes the limitations of wireless devices and maintains adequate service levels in changing environments. The majority of existing studies concentrate on adaptation modules on the client, proxy, or server. These existing studies thus suffer from the problem of having the workload concentrated on a single system. This means that increasing the number of users increases the response time of a user’s request. In this paper, the adaptation module is dispersed and arranged over the client, proxy, and server. The module monitors the context of each system and creates a dispersed adaptation system, optimized for efficient operation. Through this method, faster adaptation work is made possible, even when the number of users increases, and the dividing workload makes more stable system operation possible. In order to evaluate the proposed system, a prototype is constructed and dispersed operations are tested using multimedia content, simulating server overload and comparing the response times and system stability with existing server based adaptation systems. The effectiveness of the system is confirmed through the results.