209,114 research outputs found
The Dag-Brucken ASRS Case Study
In 1996 an agreement was made between a well-known beverage manufacturer, Super-Cola Taiwan, (SCT) and a small Australian electrical engineering company, Dag-Brücken ASRS Pty Ltd, (DB), to provide an automated storage and retrieval system (ASRS) facility as part of SCT’s production facilities in Asia. Recognising the potential of their innovative and technically advanced design, DB was awarded a State Premiers Export Award and was a finalist in that year’s National Export Awards. The case tracks the development and subsequent implementation of the SCT ASRS project, setting out to highlight how the lack of appropriate IT development processes contributed to the ultimate failure of the project and the subsequent winding up of DB only one year after being honoured with these prestigious awards. The case provides compelling evidence of the types of project management incompetency that, from the literature, appears to contribute to the high failure rate in IT projects. For confidentiality reasons, the names of the principal parties are changed, but the case covers actual events documented by one of the project team members as part of his postgraduate studies, providing an example of the special mode of evidence collection that Yin (1994) calls ‘participant-observation’
Development of a twin-head infusion pump for micromixing
Mixing is a crucial process in most of the industrial technology such as the operation of chemicals and fermentation reactors, combustion engines, polymer blends, and pharmaceutical formulations [1]. For handling a smaller volume of liquid, micromixing is a suitable method that can be applied. Micromixing (micromixer) is one of the microfluidic functions for mixing and blending liquids as precursors for biological process such as cell activation, enzyme reaction, and drug delivery system [2, 3]. There are several advantages of applying microfluidic device (micromixer) in the chemical technological processes such as processing accuracy, efficiency, minimum usage of reagents and ease of disposing of devices and fluids [3]. Basically, micromixers are categorised into passive and active micromixers. Passive micromixer consists of no moving parts and free from additional friction. It does not use external forces, fully dependent on molecular diffusion and chaotic advection for mixing process [4]. In contrast to active micromixers, external forces are applicable to active micromixers by implementing moving elements either within the microchannels, a time-variant, or a pressure field [5]. To create the pressure field differences for moving the liquid within the micromixer, an infusion pump is usually applied
Design and simulation of 1.28 Tbps dense wavelength division multiplex system suitable for long haul backbone
Wavelength division multiplex (WDM) system with on / off keying (OOK)
modulation and direct detection (DD) is generally simple to implement, less
expensive and energy efficient. The determination of the possible design
capacity limit, in terms of the bit rate-distance product in WDM-OOK-DD systems
is therefore crucial, considering transmitter / receiver simplicity, as well as
energy and cost efficiency. A 32-channel wavelength division multiplex system
is designed and simulated over 1000 km fiber length using Optsim commercial
simulation software. The standard channel spacing of 0.4 nm was used in the
C-band range from 1.5436-1.556 nm. Each channel used the simple non return to
zero - on / off keying (NRZ-OOK) modulation format to modulate a continuous
wave (CW) laser source at 40 Gbps using an external modulator, while the
receiver uses a DD scheme. It is proposed that the design will be suitable for
long haul mobile backbone in a national network, since up to 1.28 Tbps data
rates can be transmitted over 1000 km. A bit rate-length product of 1.28
Pbps.km was obtained as the optimum capacity limit in 32 channel dispersion
managed WDM-OOK-DD system.Comment: Accepted for publication in Journal of Optical Communications - De
Gruyte
Modelling and validation of synthesis of poly lactic acid using an alternative energy source through a continuous reactive extrusion process
PLA is one of the most promising bio-compostable and bio-degradable thermoplastic polymers made from renewable sources. PLA is generally produced by ring opening polymerization (ROP) of lactide using the metallic/bimetallic catalyst (Sn, Zn, and Al) or other organic catalysts in a suitable solvent. In this work, reactive extrusion experiments using stannous octoate Sn(Oct)2 and tri-phenyl phosphine (PPh)3 were considered to perform ROP of lactide. Ultrasound energy source was used for activating and/or boosting the polymerization as an alternative energy (AE) source. Ludovic® software, designed for simulation of the extrusion process, had to be modified in order to simulate the reactive extrusion of lactide and for the application of an AE source in an extruder. A mathematical model for the ROP of lactide reaction was developed to estimate the kinetics of the polymerization process. The isothermal curves generated through this model were then used by Ludovic software to simulate the “reactive” extrusion process of ROP of lactide. Results from the experiments and simulations were compared to validate the simulation methodology. It was observed that the application of an AE source boosts the polymerization of lactide monomers. However, it was also observed that the predicted residence time was shorter than the experimental one. There is potentially a case for reducing the residence time distribution (RTD) in Ludovic® due to the ‘liquid’ monomer flow in the extruder. Although this change in parameters resulted in validation of the simulation, it was concluded that further research is needed to validate this assumption
Domain-oriented architecture design for production control software
this paper, we present domain-oriented architectural design heuristics for production control software. Our approach is based upon the following premisses. First, software design, like all other forms of design, consists of the reduction of uncertainty about a final product by making design decisions. These decisions should as much as possible be based upon information that is certain, either because they represent laws of nature or because they represent previously made design decisions. An import class of information concerns the domain of the software. The domain of control software is the part of the world monitored and controlled by the software; it is the larger system into which the software is embedded. The software engineer should exploit system-level domain knowledge in order to make software design decisions. Second, in the case of production control software, using system-level knowledge is not only justified, it is also imposed on the software engineer by the necessity to cooperate with hardware engineers. These represent their designs by means of Process and Instrumentation Diagrams (PIDs) and Input-Output (IO) lists. They do not want to spend time, nor do they see the need, to duplicate the information represented by these diagrams by means of diagrams from software engineering methods. Such a duplication would be an occasion to introduce errors of omission (information lost during the translation process) or commission (misinterpretation, misguided but invisible design decisions made during the translation) anyway. We think it is up to the software engineer to adapt his or her notations to those of the system engineers he or she must work with. Third, work in patterns and software architectures started from the programminglanguage level and is now moving..
The Maunakea Spectroscopic Explorer Book 2018
(Abridged) This is the Maunakea Spectroscopic Explorer 2018 book. It is
intended as a concise reference guide to all aspects of the scientific and
technical design of MSE, for the international astronomy and engineering
communities, and related agencies. The current version is a status report of
MSE's science goals and their practical implementation, following the System
Conceptual Design Review, held in January 2018. MSE is a planned 10-m class,
wide-field, optical and near-infrared facility, designed to enable
transformative science, while filling a critical missing gap in the emerging
international network of large-scale astronomical facilities. MSE is completely
dedicated to multi-object spectroscopy of samples of between thousands and
millions of astrophysical objects. It will lead the world in this arena, due to
its unique design capabilities: it will boast a large (11.25 m) aperture and
wide (1.52 sq. degree) field of view; it will have the capabilities to observe
at a wide range of spectral resolutions, from R2500 to R40,000, with massive
multiplexing (4332 spectra per exposure, with all spectral resolutions
available at all times), and an on-target observing efficiency of more than
80%. MSE will unveil the composition and dynamics of the faint Universe and is
designed to excel at precision studies of faint astrophysical phenomena. It
will also provide critical follow-up for multi-wavelength imaging surveys, such
as those of the Large Synoptic Survey Telescope, Gaia, Euclid, the Wide Field
Infrared Survey Telescope, the Square Kilometre Array, and the Next Generation
Very Large Array.Comment: 5 chapters, 160 pages, 107 figure
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