General Electric composite ring-disk flywheel: Recent and potential developments

Recent developments of the General Electric hybrid rotor design are described. The relation of the hybrid rotor design to flywheel designs that are especially suitable for spacecraft applications is discussed. Potential performance gains that can be achieved in such rotor designs by applying latest developments in materials, processing, and design methodology are projected. Indications are that substantial improvements can be obtained

Flywheel containment and safety considerations

Flywheel safety and containment design technology are discussed. The effects of axial loading resulting from composite rotor burst tests are considered. Analysis of the radial burst problem is also included

Containment of composite fan blades

The development of containment concepts for use with large composite fan blades, taking into account the frangible nature of composite blades is considered. Aspects of the development program include; (1) an analysis to predict the interaction between a failed fan blade and the blade containment structure; (2) scaling factors to allow impact testing using subscale containment rings and simulated blades; (3) the design and fabrication of containment systems for further evaluation in a rotating rig test facility; (4) evaluate the test data against the analytically predicted results; and (5) determine overall systems weights and design characteristics of a composite fan stage installation and compare to the requirements of an equivalent titanium fan blade system. Progress in the blade impact penetration tests and the design and fabrication of blade containment systems is reported

From survey to fem analysis for documentation of built heritage: The case study of villa revedin-bolasco

In the last decade advances in the fields of close-range photogrammetry, terrestrial laser scanning (TLS) and Computer Vision (CV) have enabled to collect different kind of information about a Cultural Heritage objects and to carry out highly accurate 3D models. Additionally, the integration between laser scanning technology and Finite Element Analysis (FEA) is gaining particular interest in recent years for structural analysis of built heritage, since the increasing computational capabilities allow to manipulate large datasets. In this note we illustrate the approach adopted for surveying, 3D modeling and structural analysis of Villa Revedin-Bolasco, a magnificent historical building located in the small walled town of Castelfranco Veneto, in northern Italy. In 2012 CIRGEO was charged by the University of Padova to carry out a survey of the Villa and Park, as preliminary step for subsequent restoration works. The inner geometry of the Villa was captured with two Leica Disto D3a BT hand-held laser meters, while the outer walls of the building were surveyed with a Leica C10 and a Faro Focus 3D 120 terrestrial laser scanners. Ancillary GNSS measurements were also collected for 3D laser model georeferencing. A solid model was then generated from the laser global point cloud in Rhinoceros software, and portion of it was used for simulation in a Finite Element Analysis (FEA). In the paper we discuss in detail all the steps and challenges addressed and solutions adopted concerning the survey, solid modeling and FEA from laser scanning data of the historical complex of Villa Revedin-Bolasco

Recovery trends of commercial fish: the case of an underperforming Mediterranean marine protected area

Temporal trends in the recovery of exploited species in marine protected areas (MPAs) are useful for a proper assessment of the efficacy of protection measures. The effects of protection on the fish assemblages of the sublittoral rocky reefs in the \u201cPenisola del Sinis-Isola di Mal di Ventre\u201d MPA (W. Sardinia, Italy) were evaluated using a multi-year series of data. Four surveys, conducted 7, 10, 13 and 15 years after the area was designated as an MPA and carried out in the period spanning June and July, were used to estimate the abundance and biomass of commercial species. The surveys were carried out in zones with decreasing levels of fishing restrictions within the MPA (zones A, B, C) and in unprotected zones (OUT1 and OUT2), and underwater video visual census techniques were used. Protected zones only occasionally showed higher levels of abundance or biomass, and the trajectories of those metrics were not consistent across the years. In addition, the zone with the highest level of protection (zone A) never presented levels of abundance and biomass higher than those in zones B and C. This study shows that even 15 years after designation, protection has had no appreciable effect in the MPA studied. It is argued that this is emblematic of several shortcomings in the planning, regulation and enforcement frameworks of the MPA

WEIZZ: Automatic grey-box fuzzing for structured binary formats

Fuzzing technologies have evolved at a fast pace in recent years, revealing bugs in programs with ever increasing depth and speed. Applications working with complex formats are however more difficult to take on, as inputs need to meet certain format-specific characteristics to get through the initial parsing stage and reach deeper behaviors of the program. Unlike prior proposals based on manually written format specifications, we propose a technique to automatically generate and mutate inputs for unknown chunk-based binary formats. We identify dependencies between input bytes and comparison instructions, and use them to assign tags that characterize the processing logic of the program. Tags become the building block for structure-aware mutations involving chunks and fields of the input. Our technique can perform comparably to structure-aware fuzzing proposals that require human assistance. Our prototype implementation WEIZZ revealed 16 unknown bugs in widely used programs

ACCURACY ENHANCEMENT OF UNMANNED HELICOPTER POSITIONING WITH LOW COST SYSTEM

In the last years UAV (Unmanned Aerial Vehicle) systems are become very actractive for various commercial, industrial, public, scientific and military operations. The tasks include pipeline inspection, dam surveillance, photogrammetric survey, infrastructure maintenance, inspection of flooded areas, fire fighting, terrain monitoring, volcano observations and so on. The impressive flying capabilities provided by UAVs require a well trained pilot to be fully and effectively exploited; moreover the flight range of the piloted helicopter is limited to the line-of-sight or the skill of the pilot to detect and follow the orientation of the helicopter. Such issues have motivated the research and the design for autonomous system guidance which could both stabilize and also guide the helicopter precisely along a reference path. The constant growth of research programs and the technological progress in the field of navigation systems, as denoted by the production of more and more performing GPS/INS integrated units, allowed a strong cost reduction and payload miniaturization, making the design of low cost UAV platforms more feasible and actractive. Small autonomous helicopters have demonstrated to be a useful platform for a number of airborne-based applications such as aerial mapping and photography, surveillance (both military and civilian), powerline inspection and agricolture monitoring. In this paper we present the results of a flight simulation system developed for the setup of the servos which our autonomous guidance system will be based on. Building a simulated environment allows, indeed, to evaluate in advance what are the main issues of a complex control system, avoiding to damage fragile and expensive instruments as the ones mounted on a model helicopter

A BACKPACK MMS APPLICATION

Over the years, MMS systems have demonstrated that accuracies suitable for all but the most demanding cadastral and engineering applications can be achieved. This result, combined with a reduction in both the time and cost of data collection, made MMS a very interesting technology potentially able to meet the demand of GIS operators for rapid spatial data updating. However, the high costs involved in the arrangement of such systems did not favoured their growth in the market, so that MMS are still today mainly operated by the companies or institutions that build them. To allow a wider community of spatial data user to benefit of mobile mapping applications - in particular the lower costs and greater efficiency of data collection – a portable systems, the Backpack MMS, was developed at the University of Calgary MMS in 2001. The research centre of CIRGEO re-implemented such system introducing a few significative changes due to the adoption of different hardware and software solutions with respect to the original project. Then, within a collaborative work with a research team of the Vesuvius Observatory, in summer 2006 this version of the Backpack MMS was tested in a real environment: the goal was to assess the effectiveness of the Backpack as a tool for mapping evacuation routes on areas subjected to natural hazards. In this paper we report a description of our system configuration and the results of performed test along with a few comments on practical issues that affected the final accuracy of mapped routes