231 research outputs found
Performance Testing of Aero-Naut CAMFolding Propellers
The increase in popularity of unmanned aerial vehicles (UAVs) has been driven by their use in civilian, education, government, and military applications. However, limited on-board energy storage significantly limits flight time and ultimately usability. The propulsion system plays a critical part in the overall energy consumption of the UAV; therefore, it is necessary to determine the most optimal combination of possible propulsion system components for a given mission profile, i.e. propellers, motors, and electronic speed controllers (ESC). Hundreds of options are available for the different components with little performance specifications available for most of them. By examining a variety of existing long-endurance aircraft, Aero-Naut CAM carbon folding propellers were identified as the most commonly used type of commercial-off-the-shelf propeller. However, no performance data exist in the open literature for the Aero-Naut CAM carbon folding propellers. This paper describes the performance testing of 40 Aero-Naut CAM carbon propellers in 2-blade configuration with diameters of 9 to 16 in with various pitch values. The propellers were tested at rotation rates of 3,000 to 7,000 RPM and advancing flows of 8 to 80 ft/s, depending on the propeller and testing equipment limitations. Results are presented for the 40 propellers tested under static and advancing flow conditions with several key observations being discussed. The data produced will be available for download on the UIUC Propeller Data Site and on the Unmanned Aerial Vehicle Database
Interval-valued fuzzy decision trees with optimal neighbourhood perimeter
This research proposes a new model for constructing decision trees using interval-valued fuzzy membership values. Most existing fuzzy decision trees do not consider the uncertainty associated with their membership values, however, precise values of fuzzy membership values are not always possible. In this paper, we represent fuzzy membership values as intervals to model uncertainty and employ the look-ahead based fuzzy decision tree induction method to construct decision trees. We also investigate the significance of different neighbourhood values and define a new parameter insensitive to specific data sets using fuzzy sets. Some examples are provided to demonstrate the effectiveness of the approach
"Clone Wars": Episode II - The Next Generation: The Copyright Implications relating to 3D Printing and Computer-Aided Design (CAD) Files
The future market potential of 3D printing will rest on the dissemination of Computer Aided Design (CAD) files. Without clear instructions from a CAD file, a 3D printer will not function. In fact, “a 3D printer without an attached computer and a good design file is as useless as an iPod without music”. The importance of CAD-based design files, therefore, cannot be underestimated. Drawing on UK and EU copyright laws and their application to 3D printing and CAD files, this paper will, first, question whether CAD files can be protected by copyright law before considering the copyright implications thrown up by the modification of CAD files as a result of scanning and the use of online tools. Highlighting some of the challenges for rights holders and users existent in the present law the paper advocates new business models over a premature call for stringent intellectual property laws before concluding with some recommendations for the future
Development of simulation-based testing environment for safety-critical software
Recently, a software program has been used in nuclear power plants (NPPs) to digitalize many instrumentation and control systems. To guarantee NPP safety, the reliability of the software used in safety-critical instrumentation and control systems must be quantified and verified with proper test cases and test environment. In this study, a software testing method using a simulation-based software test bed is proposed. The test bed is developed by emulating the microprocessor architecture of the programmable logic controller used in NPP safety-critical applications and capturing its behavior at each machine instruction. The effectiveness of the proposed method is demonstrated via a case study. To represent the possible states of software input and the internal variables that contribute to generating a dedicated safety signal, the software test cases are developed in consideration of the digital characteristics of the target system and the plant dynamics. The method provides a practical way to conduct exhaustive software testing, which can prove the software to be error free and minimize the uncertainty in software reliability quantification. Compared with existing testing methods, it can effectively reduce the software testing effort by emulating the programmable logic controller behavior at the machine level
Skin cancer and Parkinson’s disease
© 2010 Movement Disorder Society
[The definitive version is available at www3.interscience.wiley.com] - [A versão definitiva está disponível em www3.interscience.wiley.com]The report of an increased frequency of melanoma during the clinical development of rasagiline prompted a renewed interest in a possible association between skin cancer and Parkinson's disease (PD). The evaluation of this risk ended in a recommendation to perform a periodic dermatological examination as a follow-up measure of their treatment. The recognition of this safety concern lead to the need to clarify if the risk of skin cancer is indeed associated with PD and if levodopa or other anti-parkinsonian drugs might contribute to increase such risk. To answer these questions, we critically reviewed all clinical studies available concerning the association between skin cancer and PD. We found 26 studies on cancer occurrence in PD. The best data available suggest the risk of cancer is reduced in PD patients. However, specific cancers like thyroid and the female breast were reported at higher-than-expected rates. Additionally, it was suggested that PD patients have a higher frequency of melanoma and non-melanoma skin cancers than the general population. The data on non-melanoma skin cancer are less robust than the data on melanoma. Causal factors remain unknown. Due to the weak association between skin cancer and PD, no robust recommendation can be made regarding the need for periodic dermatological screening.Financial Disclosure: In the past 12 months, the authors have the following information to disclose. Joaquim Ferreira, Consultancies: TEVA, Lundbeck, Ipsen, Solstice, Novartis, GlaxoSmithKline, Solvay, Grunenthal, BIAL; Advisory Boards: GlaxoSmithKline, Novartis, TEVA, Lundbeck, Allergan,
Solvay, BIAL. Mário Rosa, Honoraria: Tecnifar, Grunenthal. Olivier Rascol: Consultancies: Boehringer Ingelheim, Eisai, GlaxosmithKline, Novartis, Schering, Solvay, Teva Neuroscience, Lundbeck and UCB; Grants: Boehringer Ingelheim, Eisai, GlaxosmithKline, Novartis, Solvay, Teva Neuroscience and Lundbeck. Cristina Sampaio, Consultancies: In all cases the fees / honoraria due are paid to department and not received personally: Lundbeck, Abbott, Bial, Boeringher -LMS Group Schering-Plough, Solvay
- …