2,964 research outputs found

    The role of the user and the society in new product development

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    Within the knowledge-based economy several institutions are involved in product innovation processes. Literature study has shown that the most researched and cited are the industry-universitygovernment relations, presented in the Triple Helix model of institutional relations within new product development (NPD). Based on a case study of the Academic Virtual Enterprise, we have put the sole input of these institutions in NPD into question. We have tested and supported the claim that the user and the society are equal partners in the product innovation process. We have put forward the Fourfold Helix model that features a new formation of institutional relations where special focus is placed on the involvement of the user and the society in NPD

    The air gap between tape and drum in a video recorder

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    Lubrication with ambient air is not quite generally applied. The best known application is the "oil bearing" in tape recording systems for audio, video and computer applications; where the gap height that is needed for effective lubrication may quite easily be attained. This air gap reduces tape friction and wear of tape and recording head substantially. On the other hand, though, the air gap for effective magnetic recording is very small. These conflicting demands on the lubrication conditions ask for an accurate calculation of the air gap distribution.\ud \ud The multigrid method — a fast, iterative equation solver — will be applied to calculate the film thickness in foil bearings on a fine grid. The results for a simple but adequate model for the air lubrication between the tape and the drum in a VHS-recorder will be presented, including details about the narrow gap between recording head and tape

    A preliminary look at techniques used to obtain airdata from flight at high angles of attack

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    Flight research at high angles of attack has posed new problems for airdata measurements. New sensors and techniques for measuring the standard airdata quantities of static pressure, dynamic pressure, angle of attack, and angle of sideslip were subsequently developed. The ongoing airdata research supporting NASA's F-18 high alpha research program is updated. Included are the techniques used and the preliminary results. The F-18 aircraft was flown with three research airdata systems: a standard airdata probe on the right wingtip, a self-aligning airdata probe on the left wingtip, and a flush airdata system on the nose cone. The primary research goal was to obtain steady-state calibrations for each airdata system up to an angle of attack of 50 deg. This goal was accomplished and preliminary accuracies of the three airdata systems were assessed and are presented. An effort to improve the fidelity of the airdata measurements during dynamic maneuvering is also discussed. This involved enhancement of the aerodynamic data with data obtained from linear accelerometers, rate gyros, and attitude gyros. Preliminary results of this technique are presented

    Attitude development in designer's education

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    Modern academic design and engineering education adopted the issues and goals of holistic development of design competence. Holistic design competence is a combination of generic capacities: capability, knowledge, skill, experience and attitude. All capacities should be addressed in academic education, but the development of attitude is not sufficiently emphasized. Designers’ attitude can be seen as the relationship between a designer and the design profession. With a good designers’ attitude, different types of design problems can be solved and all the capacities, including attitude, can be developed. This paper proposes that developing a good designers’ attitude can be implemented in design education and should be done. We present the five different elements that comprise an attitude: communication, reliability, trust, motivation and open mindset. The relations between elements of designers’ attitude and other capacities of design competence are discussed. We studied the manifestation of attitudes and their development in a project of the so called Global Product Realization (GPR) course. The GPR course incorporates students from several European universities who are asked to solve a real design problem for an industrial company. The conclusion is that this project has supported the development of all five attitudinal elements. Since GPR projects are multi disciplinary, multi cultural and communication is non face-toface, a certain level of designers’ attitude is required for such projects. Further research is needed to support the vision that development of designers’ attitude needs to be addressed earlier in design education, preferably from the very first course

    Wind-tunnel investigation of a flush airdata system at Mach numbers from 0.7 to 1.4

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    Flush pressure orifices installed on the nose section of a 1/7-scale model of the F-14 airplane were evaluated for use as a flush airdata system (FADS). Wing-tunnel tests were conducted in the 11- by 11-ft Unitary Wind Tunnel at NASA Ames Research Center. A full-scale FADS of the same configuration was previously tested using an F-14 aircraft at the Dryden Flight Research Facility of NASA Ames Research Center (Ames-Dryden). These tests, which were published, are part of a NASA program to assess accuracies of FADS for use on aircraft. The test program also provides data to validate algorithms for the shuttle entry airdata system developed at the NASA Langley Research Center. The wind-tunnel test Mach numbers were 0.73, 0.90, 1.05, 1.20, and 1.39. Angles of attack were varied in 2 deg increments from -4 deg to 20 deg. Sideslip angles were varied in 4 deg increments from -8 deg to 8 deg. Airdata parameters were evaluated for determination of free-stream values of stagnation pressure, static pressure, angle of attack, angle of sideslip, and Mach number. These parameters are, in most cases, the same as the parameters investigated in the flight test program. The basic FADS wind-tunnel data are presented in tabular form. A discussion of the more accurate parameters is included

    Exaggerated CpH methylation in the autism-affected brain.

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    BackgroundThe etiology of autism, a complex, heritable, neurodevelopmental disorder, remains largely unexplained. Given the unexplained risk and recent evidence supporting a role for epigenetic mechanisms in the development of autism, we explored the role of CpG and CpH (H = A, C, or T) methylation within the autism-affected cortical brain tissue.MethodsReduced representation bisulfite sequencing (RRBS) was completed, and analysis was carried out in 63 post-mortem cortical brain samples (Brodmann area 19) from 29 autism-affected and 34 control individuals. Analyses to identify single sites that were differentially methylated and to identify any global methylation alterations at either CpG or CpH sites throughout the genome were carried out.ResultsWe report that while no individual site or region of methylation was significantly associated with autism after multi-test correction, methylated CpH dinucleotides were markedly enriched in autism-affected brains (~2-fold enrichment at p < 0.05 cutoff, p = 0.002).ConclusionsThese results further implicate epigenetic alterations in pathobiological mechanisms that underlie autism

    In-flight investigation of shuttle tile pressure orifice installations

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    To determine shuttle orbiter wing loads during ascent, wing load instrumentation was added to Columbia (OV-102). This instrumentation included strain gages and pressure orifices on the wing. The loads derived from wing pressure measurements taken during STS 61-C did not agree with those derived from strain gage measurements or with the loads predicted from the aerodynamic database. Anomalies in the surface immediately surrounding the pressure orifices in the thermal protection system (TPS) tiles were one possible cause of errors in the loads derived from wing pressure measurements. These surface anomalies were caused by a ceramic filler material which was installed around the pressure tubing. The filler material allowed slight movement of the TPS tile and pressure tube as the airframe flexed and bent under aerodynamic loads during ascent and descent. Postflight inspection revealed that this filler material had protruded from or receeded beneath the surface, causing the orifice to lose its flushness. Flight tests were conducted at NASA Ames Research Center Dryden Flight Research Facility to determine the effects of any anomaly in surface flushness of the orifice installation on the measured pressures at Mach numbers between 0.6 and 1.4. An F-104 aircraft with a flight test fixture mounted beneath the fuselage was used for these flights. Surface flushness anomalies typical of those on the orbiter after flight (STA 61-C) were tested. Also, cases with excessive protrusion and recession of the filler material were tested. This report shows that the anomalies in STS 61-C orifice installations adversely affected the pressure measurements. But the magnitude of the affect was not great enough to account for the discrepancies with the strain gage measurements and the aerodynamic predictions

    Estimation of Stability and Control Derivatives of an F-15

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    A technique for real-time estimation of stability and control derivatives (derivatives of moment coefficients with respect to control-surface deflection angles) was used to support a flight demonstration of a concept of an indirect-adaptive intelligent flight control system (IFCS). Traditionally, parameter identification, including estimation of stability and control derivatives, is done post-flight. However, for the indirect-adaptive IFCS concept, parameter identification is required during flight so that the system can modify control laws for a damaged aircraft. The flight demonstration was carried out on a highly modified F-15 airplane (see Figure 1). The main objective was to estimate the stability and control derivatives of the airplane in nearly real time. A secondary goal was to develop a system to automatically assess the quality of the results, so as to be able to tell a learning neural network which data to use. Parameter estimation was performed by use of Fourier-transform regression (FTR) a technique developed at NASA Langley Research Center. FTR is an equation- error technique that operates in the frequency domain. Data are put into the frequency domain by use of a recursive Fourier transform for a discrete frequency set. This calculation simplifies many subsequent calculations, removes biases, and automatically filters out data beyond the chosen frequency range. FTR as applied here was tailored to work with pilot inputs, which produce correlated surface positions that prevent accurate parameter estimates, by replacing half the derivatives with predicted values. FTR was also set up to work only on a recent window of data, to accommodate changes in flight condition. A system of confidence measures was developed to identify quality-parameter estimates that a learning neural network could use. This system judged the estimates primarily on the basis of their estimated variances and of the level of aircraft response. The resulting FTR system was implemented in the Simulink software system and auto-coded in the C programming language for use on the Airborne Research Test System (ARTS II) computer installed in the F-15 airplane. The Simulink model was also used in a control room that utilizes the Ring Buffered Network Bus hardware and software, making it possible to evaluate test points during flights. In-flight parameter estimation was done for piloted and automated maneuvers, primarily at three test conditions. Figure 2 shows results for pitching moment due to symmetric stabilator actuations for a series of three pitch doublet maneuvers (in a doublet maneuver, a command to change attitude in a given direction by a given amount is followed immediately by a command to change attitude in the opposite direction by the same amount). A time window of 5 seconds was used. The portions of the curves shown in red are those that passed the confidence tests. The technique showed good convergence for most derivatives for both kinds of maneuvers - typically within a few seconds. The confidence tests were marginally successful, and it would be necessary to refine them for use in an IFCS

    A novel design education approach for professional global product realization

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    Emerging trends in design practice, such as collaborative design and multi-national, multi-cultural and multi-disciplinary (multi-x) teamwork, call for ongoing changes in design education. Educational institutions need to be proactive in adapting to such trends, in order to ensure an adequate development of the design competences of their students. The graduated design students must be able to effectively solve real-life new product development (NPD) problems in multi-x environments. In this paper we present a novel approach towards design education, where special focus is put on multi-x collaboration of design students in solving NPD tasks. We present the idea of an Academic Virtual Enterprise (AVE), a project oriented educational agreement, which is based on volatile alliance of industrial and academic partners for mutual advantages. A course, called Global Product Realization (GPR) is presented as an example of how to implement AVE into design education and provide a stimulating learning environment for students in several disciplines (i.e. mechanical engineering, programming, electronics, design, etc.), where they can get experience in multi-x collaboration in NPD and develop several aspects of design competences needed for their future professional practice

    Multi-dimensional digital human models for ergonomic analysis based on natural data representations

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    Digital human models are often used for ergonomic analysis of product designs, before physical prototypes are available. However, existing digital human models cannot be used to simultaneously: 1) consider the tissue loads and the physiological effects of the tissue loads; 2) optimise the product properties. This paper develops multi-dimensional digital human models for ergonomic analysis based on natural data representations, which include anatomy, morphology, behaviour, physiology, tissue, and posture data representations. The results show that the multi-dimensional digital human models can be used to: 1) accelerate the design process; 2) assess mechanical and physiological loads inside the body and in the contact area between the body and the product; 3) optimise the quality of the product; 4) reduce the number of user trials needed to create the product.Design EngineeringIndustrial Design Engineerin
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