Silicon shadow mask fabrication for patterned metal deposition with microscale dimensions using a novel corner compensation scheme

Pattern deposition of metals with controlled and microscale dimensions can be a challenging task if traditional photolithography is not a practical option. This is a particularly valid concern for the case of certain polymer substrates, which are gaining in importance in the microelectronics and related industries. Therefore, a novel design and process flow for batch fabricating low cost reusable silicon shadow masks was developed. Of note was the corner compensation scheme employed to avoid over-etching of the convex corners in the design. These shadow masks enabled deposition of metals or other suitable materials with feature sizes ranging from approximately 3 to 250 μm and were successfully utilized to form patterned metal heater lines and pads on various samples. The heaters, required for conducting thermal conductivity measurements of the underlying films/substrates using the three omega (3ω) method, showed resistance–temperature linearity, confirming theoretical estimates to within 0.2%. Moreover, the room temperature thermal conductivity of an amorphous SiO₂ film as well as a polyaniline thick film were measured, further validating the deposition through shadow mask technique.     

Interval routing in some planar networks

In this article, we design optimal or near optimal interval routing schemes (IRS, for short) with small compactness for several classes of plane quadrangulations and triangulations (by optimality or near optimality we mean that messages are routed via shortest or almost shortest paths). We show that the subgraphs of the rectilinear grid bounded by simple circuits allow optimal IRS with at most two circular intervals per edge (2-IRS). We extend this result to all plane quadrangulations in which all inner vertices have degrees4. Namely, we establish that every such graph has an optimal IRS with at most seven linear intervals per edge (7-LIRS). This leads to a 7-LIRS with the stretch factor 2 for all plane triangulations in which all inner vertices have degrees6. All routing schemes can be implemented in linear time.     

Integrated Data Management for a Fleet of Search‐and‐rescue Robots

Search‐and‐rescue operations have recently been confronted with the introduction of robotic tools that assist the human search‐and‐rescue workers in their dangerous but life‐saving job of searching for human survivors after major catastrophes. However, the world of search and rescue is highly reliant on strict procedures for the transfer of messages, alarms, data, and command and control over the deployed assets. The introduction of robotic tools into this world causes an important structural change in this procedural toolchain. Moreover, the introduction of search‐and‐rescue robots acting as data gatherers could potentially lead to an information overload toward the human search‐and‐rescue workers, if the data acquired by these robotic tools are not managed in an intelligent way. With that in mind, we present in this paper an integrated data combination and data management architecture that is able to accommodate real‐time data gathered by a fleet of robotic vehicles on a crisis site, and we present and publish these data in a way that is easy to understand by end‐users. In the scope of this paper, a fleet of unmanned ground and aerial search‐and‐rescue vehicles is considered, developed within the scope of the European ICARUS project. As a first step toward the integrated data‐management methodology, the different robotic systems require an interoperable framework in order to pass data from one to another and toward the unified command and control station. As a second step, a data fusion methodology will be presented, combining the data acquired by the different heterogenic robotic systems. The computation needed for this process is done in a novel mobile data center and then (as a third step) published in a software as a service (SaaS) model. The SaaS model helps in providing access to robotic data over ubiquitous Ethernet connections. As a final step, we show how the presented data‐management architecture allows for reusing recorded exercises with real robots and rescue teams for training purposes and teaching search‐and‐rescue personnel how to handle the different robotic tools. The system was validated in two experiments. First, in the controlled environment of a military testing base, a fleet of unmanned ground and aerial vehicles was deployed in an earthquake‐response scenario. The data gathered by the different interoperable robotic systems were combined by a novel mobile data center and presented to the end‐user public. Second, an unmanned aerial system was deployed on an actual mission with an international relief team to help with the relief operations after major flooding in Bosnia in the spring of 2014. Due to the nature of the event (floods), no ground vehicles were deployed here, but all data acquired by the aerial system (mainly three‐dimensional maps) were stored in the ICARUS data center, where they were securely published for authorized personnel all over the world. This mission (which is, to our knowledge, the first recorded deployment of an unmanned aerial system by an official governmental international search‐and‐rescue team in another country) proved also the concept of the procedural integration of the ICARUS data management system into the existing procedural toolchain of the search and rescue workers, and this in an international context (deployment from Belgium to Bosnia). The feedback received from the search‐and‐rescue personnel on both validation exercises was highly positive, proving that the ICARUS data management system can efficiently increase the situational awareness of the search‐and‐rescue personnel.     

Analysis of Combined Systems of Two Endoreversible Engines

A single endoreversible engine can operate as a cooler, a true heat engine, a heat pump, or a refrigerator. We investigate how many different modes of operation a combined system of two endoreversible engines may display. Special attention is paid to the independent combined system which neither consumes nor supplies power.     

Automatic benchmark profiling through advanced workflow‐based trace analysis

Benchmarking has proven to be crucial for the investigation of the behavior and performances of a system. However, the choice of relevant benchmarks still remains a challenge. To help the process of comparing and choosing among benchmarks, we propose a solution for automatic benchmark profiling. It computes unified benchmark profiles reflecting benchmarks' duration, function repartition, stability, CPU efficiency, parallelization, and memory usage. Our approach identifies the needed system information for profile computation and collects it from execution traces captured without benchmark code modifications. It structures profile computation as a reproducible workflow for automatic trace analysis, which efficiently manages important trace volumes. In this paper, we report on the design and the implementation of our approach, which involves the collection and analysis of about 500 GB of trace data coming from 2 different platforms (an x86 desktop machine and the Juno SoC board). The computed benchmark profiles provide valuable insights about the benchmarks' behavior and help compare different benchmarks on the same platform as well as the behavior of the same benchmark on different platforms.     

Using the cassiopeia method to design a robot soccer team

We have defined the Cassiopeia method, whose specificity is to focus the analysis and design of a multiagent system on the notion of organization. This article reports the use of this methodological framework for designing and implementing the organization of a robot soccer team in the context of a research project on collective robotics. We show why we chose this application, and we discuss its interest and inherent difficulties, in order to clearly express the needs for a design methodology dedicated to distributed artificial intelligence.     

Six Synthesis Methods for Reversible Logic

The (2 ^w )! reversible transformations on w wires, i.e. reversible logic circuits with w inputs and w outputs, together with the action of cascading, form a group, isomorphic to the symmetric group S ₂ ^w . Therefore, we investigate the group S _n as well as one of its subgroups isomorphic to S _n/2 × S _n/2. We then consider the left cosets, the right cosets, and the double cosets generated by the subgroup. Each element of a coset can function as the representative of the coset. The coset can then be considered as the set of all group elements that differ from the representative by merely multiplying (either to the left or to the right or to both sides) by an arbitrary element of the subgroup. Different choices of the coset space and different choices of the coset representatives lead to six different syntheses for implementing an arbitrary reversible logic operation into hardware. Evaluation of all six methods, by means of three different cost functions (gate cost, switch cost, and quantum cost), leads to a best choice.     

Application of a new algorithm using Doppler information to retrieve complex wind fields over the Black Sea from ENVISAT SAR images

Several algorithms have been proposed to retrieve near-surface wind fields from C-band synthetic aperture radar (SAR) images acquired over the ocean. They mainly differ in the way they retrieve the wind direction. Conventionally, the wind direction is taken from atmospheric models or is extracted from the linear features sometimes visible in SAR images. Recently, a new wind retrieval algorithm has been proposed, which also includes the Doppler shift induced by motions of the sea surface. In this article, we apply three wind retrieval algorithms, including the one using Doppler information, to three complex wind events encountered over the Black Sea and compare the SAR-derived wind fields with model wind fields calculated using the high-resolution weather research and forecasting (WRF) model. It is shown that the new algorithm is very efficient in resolving the 180° ambiguity in the wind direction, which is often a problem in the streak-based wind retrieval algorithms. However, the Doppler-based algorithm only yields good results for wind directions that have a significant component in the look direction of the SAR antenna. Furthermore, it is dependent on good separation of the contributions to the Doppler shift induced by surface currents and wind-related effects (wind drift and wind-sea components of the ocean wave spectrum). We conclude that an optimum wind retrieval algorithm should consist of a combination of the algorithms based on linear features and Doppler information.     

Switching networked attitude control of an unmanned quadrotor

In this article, a switching networked attitude controller for an unmanned quadrotor over a wireless sensor network is presented. To deal with the network induced time varying delays, the quadrotor is being modeled as a switching time varying linear system, while the applied switching output feedback control scheme, is calculated based on Linear Matrix Inequalities, and is able to guarantee the stability of the quadrotor under arbitrary changes in the time delays.