The learning-decoding approach as a means of overcoming the barriers to growth in small & medium size enterprises

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This thesis explores how small business owners learn to learn' to overcome barriers to growth or commercial success. This learning takes place within a process which has been termed the Learning-Decoding Approach. This Approach consists of three main factors - (1) how small business owners Scan their environment for signals and cues; (2) how they Decode any signals and cues; and (3) how they Test their Mental models and Assumptions - this factor incorporates an analysis of the inclination to be Open to changing or affirming the Mental Models and Assumptions held. Further, it examines what the small business owner does with the final result from this process: that is, is it used to influence the design of some strategic plan or does it become part of an emerging one? Generally, it was found that Strategic Planning is not a function of the Learning- Decoding Approach. It is not considered a core tool for overcoming barriers to growth. Its major role is at the task or operational level rather than the business level. Further, any attempt at Strategy Planning is only used as a guide. Fifty small firms were investigated within two `knowledge-worker' sectors: the Management Consulting Sector and the Marketing Consulting Sector. Within these sectors three sizes of firms were reviewed. Thirty-eight male and twelve female owner-managers were involved in the interviews. The research identified a number of similarities and some differences between the sectors; and provided a cultural explanation for them. The daily work practices used by owner-managers showed that the sectors were different but closely aligned. A tentative Learning-Decoding Approach model was developed and comprised three spectrums. Firms can be positioned on them according to their predisposition to, and skills in, Scanning the environment for signals, and Decoding the signals and then Testing them against their Mental Models and Assumptions. Further, if learning is to occur the owner-manager must be prepared to be open to changing any Mental Models and Assumptions held. By learning the skills implicit in this process, the owner-manager can move on to learning how to overcome the barriers to growth. This suggests that the Learning- Decoding Approach can provide a helpful model for advisers to enable them to mentor, coach, counsel or facilitate small business owners in a review of their business style and practice. The main conclusion drawn from the thesis is that Scanning, Decoding and Testing are perceived as valuable activities which influence commercial success. However, a gap is evident between attitude and behaviour. Due to this, it is felt that the aims of the research are only partly met

Incorporating solar activity into general perturbations analysis of atmospheric friction

A new parameter is introduced, termed the density index, which enables the solar activity cycle to be captured in a new analytical atmospheric density model. Consequentially, a new solar activity model is developed that uses a single independent variable per solar cycle to describe the solar activity across that cycle, as indicated by the F10.7 index. These models are combined and applied to a well-known general perturbations method for satellite orbit lifetime analysis, which is first modified using modern mathematical tools to remove simplifications in the derivation. Validation against historical data shows an improvement in orbit lifetime estimates from an average error of 50.44 percent with a standard deviation of 24.96 percent, to an average error of 3.46 percent with a standard deviation of 3.25 percent. Furthermore, the new method with applied atmospheric and solar activity models is found to compare favorably against other general and special perturbations methods, including third party, and commercial software, the most accurate of which was found to have an average error of 6.63 percent and standard deviation of 7.00 percent. A case study, the UKube-1 spacecraft, is presented and it is found that the spacecraft was inserted into an orbit 54km lower than required to comply with best-practice guidelines, and that with 1σ confidence its orbit will decay in June 2028 ± 2 years, and June 2028 ± 4 months if the next solar cycle is an average magnitude cycle

Improving the accuracy of general perturbations methods of spacecraft lifetime analysis

Using modern mathematic tool sets, various general perturbations methods such as the methods developed by the authors1,2, by Cook, King-Hele & Walker3 or by Griffin & French4 among others can be enhanced with the development of an average projected area model. A new method of determining the average projected area of a tumbling CubeSat is presented, which improves on the accuracy of the method recommended in Section 6.3 of the ISO standard 27852:2010(E)5. This enhancement can be applied to many different general perturbations methods and due to its simple mathematical nature it allows users to perform rapid Monte-Carlo analyses with thousands of permutations of the problem. Traditional numerical or even semi-analytical solutions would require a much greater length of time to produce an orbit lifetime prediction for a single permutation. For the range of CubeSat configurations presented it can be seen that the new method improves the error in the average projected area from, approximately 27% to within 5%. The enhancements are seen to outperform the ISO standard consistently and the ISO standard is seen to consistently overestimate the average projected area when considering non-cuboid spacecraft configurations, meaning that when applied to an orbit decay model it will consistently underestimate the orbit lifetime. However its worth lies not only in the improvement in accuracy but also in the time saved when considering space debris analysis or in initial mission design where many parameters may be unknown. In these situations the ability to swiftly provide solutions for thousands of permutations of the problem or to provide a range of predictions based on initial uncertainties and a confidence value for that range is invaluable. The enhanced solution has then been demonstrated using UKube-1 (COSPAR spacecraft identification 2014-037F) as a case study. It can be seen that the new method outperforms the ISO standard, with an error in the average projected area of 8.09% compared to the ISO standards 14.48%

An analytical low-cost deployment strategy for satellite constellations

This work proposes a novel method for the deployment of a constellation of nano-satellites into Low Earth Orbit by using carrier vehicles to deliver the nano-satellites into the required orbit positions. The analytical solution presented allows for rapid exploration of the design space and a direct optimisation of the deployment strategy to minimise the time for complete constellation deployment. Traditionally, the deployment of satellite constellations requires numerous launches – at least one per orbital plane – which can be costly. Launching as a secondary payload may offer significant cost reductions, but this comes at the price of decreased control over the launch schedule and final orbit parameters. The analytical method presented here allows for the optimal positioning of the orbit planes of the constellation to be determined and the minimum time for deployment determined as a function of the manoeuvre ΔV. The effect of atmospheric drag on the manoeuvre propellant cost is also considered to ensure a realistic deployment scenario. A case study considering three constellation designs is presented which compares the cost of deployment using traditional launch methods with that of deploying the constellation using carrier vehicles. The results of this study show a significant reduction in cost when using the carrier vehicles on a dedicated launch, compared with launching the satellites individually. Most significantly, the launch cost when using carrier vehicles is primarily determined by the total number of satellites in the constellation, rather than the number of orbital planes. Thus, the carrier vehicle deployment strategy would allow for constellations with a large number of planes to be deployed for a fraction of the equivalent cost if traditional launch methods were used

Improving the accuracy of orbit lifetime analysis using enhanced general perturbations methods

The general perturbations method for orbit lifetime analysis developed by the authors is improved by using spacecraft orbit decay tracking data to inform orbit lifetime predictions. This data is used to derive input parameters such as mass, and drag coefficient in order to make the method independent from error in these inputs, which can be a major source of error in orbit lifetime predictions. These derived inputs are then used to generate more accurate predictions while still maintaining the speed of the original method. The accuracy of the new method is validated against the authors' original method and historical data

General perturbations method for orbit lifetime analysis incorporating non-spherically-symmetrical atmospheres

A general perturbations method for orbit lifetime analysis is extended to include an analytical non-spherically-symmetrical atmospheric density model. This improvement allows the method to be applied with confidence to highly inclined orbits and special cases such as sun-synchronous orbits where the inclusion of the effects of atmospheric oblateness and the diurnal bulge will be particularly significant. These improvements can be applied to any general perturbations model for lifetime analysis. Using a case study of a sun-synchronous satellite a comparison is drawn between the original and improved methods, showing that by capturing the effects of a non-spherically-symmetrical atmosphere the orbit lifetime predicted could be up to 7% longer or 10% shorter than when using the spherically-symmetrical model. Also notable is the difference between the orbit lifetime predictions made using the spherically-symmetrical model derived from different data sets; for the case study this was approximately a third of the orbit lifetime

Fractional boundary value problems: Analysis and numerical methods

This is the author's PDF of an article published in Fractional calculus and applied analysis 2011. The original publication is available at www.springerlink.comThis journal article discusses nonlinear boundary value problems.Fundacao para a Ciencia e Tecnologi

Taxonomy and analysis of issues facing post mission disposal concept

In order to ensure a sustainable space environment for future generations a strategy for all spacefarers must be developed in order to mitigate the growth of the space debris population. To this end, this preliminary analysis is the first step towards the development of a cost-efficient but highly reliable PMD (Post Mission Disposal) module. This PMD module will be attached to the spacecraft on ground and will ensure the removal of the spacecraft at the end of the nominal operational lifetime or act as a removal back-up in the case of loss of control of the spacecraft. The PMD module will be scalable and flexible, enabling the PMD of any future spacecraft in an Earth orbit. Ultimately, the gap between the 90% PMD success rate required by ISO 24113:2011(E) and the current success rate of 50%-60% can be closed. A survey of de- and re-orbit techniques and concepts was carried out and a taxonomy of approximately 40 concepts, including 12 which do not appear in the literature, is presented. A qualitative analysis was carried out on the concepts identified in the taxonomy, and a comparison matrix was built including 12 different comparison metrics. The 5 most promising concepts for the PMD module were down-selected from this matrix. These concepts were: drag augmentation, solar sailing, electrodynamic tether, low thrust propulsion and high thrust propulsion. A further 3 additional concepts were also defined by considering combinations of the down-selected concepts. A quantitative analysis of the down-selected concepts was performed using a purpose built analytical analysis tool. This tool was designed to rapidly predict re-entry epochs of space objects, given specific mission parameters. The analytical nature of this tool allowed for a Monte Carlo analysis, resulting in trade-off analyses within and between the different concepts for various mission parameters. The output of the quantitative analysis provided preliminary mission parameters, systems sizing and trade-off data on each of the down-selected concepts and combination concepts. From this analysis it was concluded that each system had its advantages, and challenges, so recommendations were made on how each system could be used to its maximum potential and which systems were more effective than others in specific situations. The most prominent of these results were the need for the PMD to de-tumble the spacecraft prior to deployment of the removal system, and the fact that none of the down-selected concepts were recommended for use in long term missions