Jürg Gutknecht

An Educational and Research Kit for Activity and Context Recognition from On-body Sensors

We present an educational and research kit to support hands-on teaching and experience of real-time activity or gesture recognition from on-body sensors. The kit is comprised of: wireless wearable sensor nodes for motion and ECG sensing; software infrastructure for synchronized data acquisition from multiple sensors, data visualization, signal alignment, and synchronized signal/video exploration; algorithm demonstration and education software with a hidden Markov model-based activity recognition system and a low-latency gesture recognition for a platform game; support hardware for the annotation of user activities from a wireless keypad, and for prototyping of other wireless sensor nodes. All hardware and software is open-source.

Do the Fish Really Need Remote Control? A Proposal for Self-Active Objects in Oberon

Based on the language Oberon we propose a unified framework for concurrent, object-oriented programming. Inspired by simulation, the idea is to regard objects as processes in contrast with the more common approach treating processes as objects. More concretely, our framework extends the original Oberon language by four new concepts: (a) Object-centered access protection, (b) object-local activity control, (c) system-guarded assertions and (d) preemptive priority scheduling. (a) and (b) are expressed syntactically by upgraded record types, (c) by a passivation/activation mechanism and (d) by a priority option. None of the conventional facilities like semaphores, locks, critical regions, signals, channels, rendez-vous, forks etc. are primitive constructs in our framework. Currently, an implementation of a compiler, a corresponding runtime kernel and a non-blocking local server exists for native Intel architectures.

Stress and sleep quality estimation from a smart wearable sensor

The stress and poor sleep quality of a person may be used as two of several components for predicting the onset of mental health problems, in particular depression. Ergonomie smart sensors that can determine the heart rate variations related to stress and the variability of sleep may provide unique insights to the coping behavior of stressed people. Rather than relying on wearable computers, a single smart miniature sensor that is worn 24/7 should perform the complex embedded recognition tasks while meeting difficult battery life, wireless communications and ergonomie constraints. The development and testing of such a smart sensor is described focusing on implementation within a distributed intelligence based architecture. The manner in which the users heart rate and the users physical motion is used to measure stress and sleep quality is explained.

Towards dynamic and cooperative multi-device personal computing

The significant technological advances in hardware miniaturisation and data communications change the landscape of computing in a profound way. A rich variety of sensing, storage and processing nodes will soon be embedded in artefacts and clothes worn by people. Numerous computing elements will be integrated in appliances, furniture, buildings, public spaces and vehicles. It now becomes possible to move beyond the physical but also mental boundaries of the desktop, and to develop novel forms of computing that will efficiently support people in their daily activities without constantly being in the center of their attention.

Ergonomic Low Cost Motion Capture for every day health exercise

Pervasive applications often require context information about the posture, ambulatory and work activity of the user. This paper reports ongoing work on the development of a low cost ergonomic approach to motion capture that provides the opportunity to examine diverse body movement in home and office environments. In this research case it is applied to the automatic training of Tai Ji Quan at different levels of complexity. Results of the sensor design, communications architecture and human body computer motion modeling are presented.

Array-Structured object types for mathematical programming

In this paper a concept for structured mathematical programming within an object-oriented language is presented. It leads to better readable, more natural and more compact code in typical linear algebra applications and provides options for optimized implementation. We also discuss the realization of this concept as an extension of the programming language Active Oberon. We define new built-in array types that provide a slight modification of classical arrays in Oberon. By introducing range-valued indices as array designators, we permit the use of regular sub-domains of arrays as parameters of operators and procedures. The built-in types are complemented by custom array structured object types. The latter can be specified by the programmer and are designed to be syntactically compatible with the former. They provide the needed flexibility for the language.

Frequency-Specific Functional Connectivity Density as an Effective Biomarker for Adolescent Generalized Anxiety Disorder

Several neuropsychiatric diseases have been found to influence the frequency-specific spontaneous functional brain organization (SFBO) in resting state, demonstrating that the abnormal brain activities of different frequency bands are associated with various physiological and psychological dysfunctions. However, little is known about the frequency specificities of SFBO in adolescent generalized anxiety disorder (GAD). Here, a novel complete ensemble empirical mode decomposition with adaptive noise method was applied to decompose the time series of each voxel across all participants (31 adolescent patients with GAD and 28 matched healthy controls; HCs) into four frequency-specific bands with distinct intrinsic oscillation. The functional connectivity density (FCD) of different scales (short-range and long-range) was calculated to quantify the SFBO changes related to GAD within each above frequency-specific band and the conventional frequency band (0.01–0.08 Hz). Support vector machine classifier was further used to examine the discriminative ability of the frequency-specific FCD values. The results showed that adolescent GAD patients exhibited abnormal alterations of both short-range and long-range FCD (S-FCD and L-FCD) in widespread brain regions across three frequency-specific bands. Positive correlation between the State Anxiety Inventory (SAI) score and increased L-FCD in the fusiform gyrus in the conventional frequency band was found in adolescents with GAD. Both S-FCD and L-FCD in the insula in the lower frequency band (0.02–0.036 Hz) had the highest classification performance compared to all other brain regions with inter-group difference. Furthermore, a satisfactory classification performance was achieved by combining the discrepant S-FCD and L-FCD values in all frequency bands, with the area under the curve (AUC) value of 0.9414 and the corresponding sensitivity, specificity, and accuracy of 87.15, 92.92, and 89.83%, respectively. This study indicates that the alterations of SFBO in adolescent GAD are frequency dependence and the frequency-specific FCD can potentially serve as a valuable biomarker in discriminating GAD patients from HCs. These findings may provide new insights into the pathophysiological mechanisms of adolescent GAD.

Active Cells: A Computing Model for Rapid Construction of On-Chip Multi-core Systems

We present a novel computing model that allows to conveniently construct multi-core systems with different computer architectures, ranging from homogeneous many-core architectures to networks of heterogeneous general purpose processor cores or signal processing engines. A hardware library implemented on Field Programmable Gate Arrays (FPGAs) and a compiler provide a platform for prototyping and constructing distributed systems on a chip. A number of case studies have been carried out to prove the concept conveyed by the computing model.

A Reconfigurable Multi-core Computing Platform for Robotics and e-Health Applications

Increasingly embedded devices are turning to two technologies to achieve high performance and enable efficient programmability as well as product usability. The first is multi-core processing on FPGA devices in which the multi-core architecture allows software to map application-level parallelism to inherent parallel fabric to offer better performance, the re-configurability leads to flexible and adaptive designs. The second is wireless communications that allow sensors to be distributed flexibly across a structure for example in the case of a body area network. This paper describes the ongoing design of a multi RF channel, multi-core embedded design which will be used as a generic FPGA solution to meet the requirements of both e-health applications as well as robotics applications.

ERA: Evolving Reconfigurable Architecture

A new paradigm to design computer systems called evolving reconfigurable architecture (ERA) is proposed. Several holistic principles are introduced and pursued through the ERA design cycle. We show how reconfigurability is implemented at the level of hardware elements and system software structure. Two new models: (i) graph-logic and (ii) control-data-predicate are introduced and applied in the ERA. We propose a scheme to transform sequential programs for execution on ERA, we also show that ERA has exceptional flexibility and reconfigurability and fits embedded, high performance and safety critical applications. Finally, further progress of ERA is discussed.