The Design and Implementation of a bespoke Enterprise Resource Planning System (ERP) for an acoustical engineering company

This paper will describe the tasks completed so far as part of a Knowledge Transfer Partnership between the University of Hertfordshire and Acoustical Control Engineers (ACE) a ‘small and medium sized enterprise’ (SME) based in Cambridgeshire, UK. ACE’s 25 personnel design, manufacture and install noise and vibration control systems to solve a wide range of acoustic problems. The projects undertaken include acoustic enclosures for supermarket refrigeration plant and for generators used in many situations, together with other more diverse applications such as controlling noise in the workplace and even on a luxury boat. Before the current KTP project the company used some partially computerised systems consisting of spreadsheets to perform acoustic analyses, pricing and project management functions supplemented with a paper based system to ‘fill the gaps’. Enterprise Resource Planning (ERP) systems provide an integrated database for all parts of the organisation allowing decisions to be based on a complete understanding of the organisation’s information, avoiding the problems due to duplication of data and ensuring that the consequences of decisions in one part of the organisation are reflected in the planning and control systems of the rest of the organisation. ERP systems became popular from the 1990’s mainly in relatively large organisations due to the complexity and cost of these systems. This project is unusual in that rather than adapting an off-the-shelf ERP solution to ACE’s very specific and specialised requirements we are taking an ERP development approach in an SME whose legacy systems are made up of spreadsheet and paper based systems. For the software development an Agile approach has been used. Agile involves software development methods based on iterative and incremental development. The initial attempt was to start developing the ERP from an Open Source ERP Source Code; however this effort was futile as a result of the bespoke nature of ACE’s business and product lines. Mapping ACE’s data model to the database which any existing ERP system could be adapted to, proved to be a very difficult problem. Therefore, developing the ERP from first principles was inevitable. Several of the ERP modules have been developed, user training has taken place and the core modules have been signed off. The project is due to complete in September 2014 and by this time we will have further information on how the ERP system has increased the competitiveness of the company, as well as experience of introducing an ERP into an SME. However, as would be expected the work undertaken developing the system so far has had several significant effects on ACE and acted as a catalyst for change in various parts of ACE’s business.Non peer reviewe

The Resonator Banjo Resonator, part 2: What makes them really crack?

A simple experiment quantifies the difference between the sound production of a banjo with and without a resonator back. Driven by a small tweeter mounted inside the pot, for frequencies above about 4500 Hz, the produced external sound is 6 to 10 dB louder with the resonator than without. With the banjo played in any normal fashion, this gives a negligible contribution to the overall volume. However, that difference is clearly a reflection of the universally recognized resonator sound, in close analogy to plosive consonants in human speech. No direct correlation is observed between the head-resonator separation and the spectrum of the enhanced response. This suggests that direct reflection off the back is not a primary contributor to the resonator/openback difference, leaving differences in overall absorption as the major suspect.Comment: 19 pages, 6 figures, 4 mp3 file

Acoustic tamper detection sensor with very low false alarm rate

We describe a device designed to detect interference (vandalism or tampering) by acoustic means. The design employs both a piezoelectric vibration transducer and a common microphone in a novel mechanical arrangement. In contrast to conventional acoustic sensors that simply respond to vibrations above a threshold, this design analyses the outputs of the two to trigger an alarm. The method confers a near-zero susceptibility to triggering by external loud noises. No complex calculations are required so that only a low-cost, embedded microcontroller is required and the whole sensor can be very cheap. Extreme sensitivity can be achieved with little risk of false alarms

3D-printed Acoustic Directional Couplers

Acoustic Directional Couplers permit separation of forward and reverse sound pressure waves. This separation opens the way to traceable precision acoustic reflection measurements. In order to span the audio frequency range, multiple couplers will be required, as each operates over a frequency range of slightly more than one octave. To reach 20kHz or above requires vary small, mechanically precise construction. We achieve this by 3D printing techniques. We manufactured two otherwise-identical couplers, one made with a powder-type 3D printer with photopolymer support structure, the other made with an ABS-filament thermoplastic-type 3D printer. We compare the measured acoustic performance of these two couplers. The wavelength of sound at 20 kHz is comparable to that encountered at a microwave frequency of 18 GHz. We expect to be able to fabricate couplers that reach 55 kHz where the wavelength is 6 mm, corresponding to a frequency of 50 GHz in the electromagnetic spectrum

Reduced-Noise Gas Flow Design Guide Developed as a Noise-Control Design Tool for Meeting Glenn's Hearing Conservation and Community Noise Goals

A Reduced-Noise Gas Flow Design Guide has been developed for the NASA Glenn Research Center at Lewis Field by Nelson Acoustical Engineering of Elgin, Texas. Gas flow systems are a significant contributor to t he noise exposure landscape at Glenn. Because of the power of many of these systems, hearing conservation and community noise are importan t issues. The purpose of the Guide is to allow Glenn engineers and de signers to address noise emission and control at the design stage by using readily available system parameters. Although the Guide was deve loped with Glenn equipment and systems in mind, it is expected to hav e wide application in industry

Semiempirical airframe noise prediction model and evaluation with flight data

A semiempirical maximum overall sound pressure level (OASPL) airframe noise model was derived. Noise radiated from aircraft wings was modeled on the trailing edge diffractes quadrupole sound theory. The acoustic dipole sound theory was used to model noise from the landing gear. The model was correlated with maximum OASPL flyover noise measurements obtained for three jet aircraft. One third octave band sound pressure level flyover data was correlated and interpreted

Modeling and Compensation of Nonlinear Distortion in Horn Loudspeakers

Horn loaded compression drivers are widely used in the area where high sound pressure levels together with good directivity characteristics are needed. Major disadvantage of this kind of drivers is the considerable amount of nonlinear distortion. Due to the quite high air pressures in the driver the air is driven into its nonlinear range. This paper describes a technique to reduce the distortion caused by this phenomenon. Using a Digital Signal Processor (DSP), a feedforward compensation technique, based on an equivalent lumped parameter circuit, is implemented and tested in real–time in series with the loudspeaker. Measurement and simulation results are given. The overall conclusion is that a distortion reduction is obtained in the frequency span from 600 to 1050 Hz

A Knowledge Transfer Partnership - the development of a Bespoke Enterprise Resource Planning System in the UK

Abstract. A Knowledge Transfer Partnerships (KTP) is a UK-wide programme designed to enable businesses to improve their competitiveness, productivity and performance. A KTP achieves this through the forming of a Partnership between a business and an academic institution. The aim is to enable businesses to access skills and expertise from academics and embed this knowledge in their businesses in order to develop the business. The knowledge sought is embedded into the business through a project, or projects, undertaken by a recently qualified person (known as the Associate). Part funding is provided by the government towards the Associate’s salary and towards the release of an Academic supervisor who works a half a day a week at the company. KTPs can vary in length from 6 months to three years, depending on the needs of the business and the desired outcomes. Therefore a KTP enables new capability to be embedded into the business and has benefited and continues to benefit a wide range of businesses across many sectors in the UK, including micro sized, small and large businesses across many sectors. This paper describes a Knowledge Transfer Partnership project between the University of Hertfordshire and a small and medium sized enterprise (SME) based in Cambridgeshire, UK.Final Accepted Versio