OAR@UM Collection:
/library/oar/handle/123456789/25427
2025-11-04T21:50:13ZEmotional ‘design for X’ : a human and life phase systems meetings consequence knowledge approach
/library/oar/handle/123456789/70808
Title: Emotional ‘design for X’ : a human and life phase systems meetings consequence knowledge approach
Abstract: Throughout the various phases of its life, an evolving product meets with life phase system
elements that include technical systems (e.g. fabrication machines) and human individuals (e.g.
customers and factory operators). The design commitments made in relation to both the product
and life phase system elements are associated with consequences that emerge from life phase
system meetings. Knowledge of these consequences is of relevance to decision makers because of
their impact on business metrics such as cost and time.
An empirical study was carried out to address the lack of evidence on the relation between design
commitments, human factory operators’ emotions and business metrics. Throughout the study,
each subject was required to perform two manual assembly tasks. The emotions experienced by
each subject were captured via of a questionnaire that was administered by the author. A statistical
analysis established that the emotions experienced by human subjects during manual assembly,
mediate the impact of design commitments on metrics such as cost and time. Furthermore the
literature review established that product development decision makers lack adequate means to
foresee emotional consequences and to handle the impact on business metrics. This is because
design support means, such as design for manufacturing (DfM), have been intended to help
designers foresee direct (D) physical consequences that emerge from life phase system meetings.
Whereas design for emotion (DfE) support means focus exclusively on the emotions that customers
experience when meeting with a developed product.
By focusing on a single life phase, this dissertation implements and evaluates the ‘Human and Life
Phase Systems Meetings’ (HLSM) consequence knowledge approach framework to emotional
Design for X (eDfX). At the core of the HLSM approach framework is the knowledge model which
draws inferences about direct (D) and emotional (E) consequences associated with design
commitments. This knowledge guides decision makers in exploring alternative design commitments
to mitigate direct (D) and emotional (E) consequences having undesirable effects on metrics such
as cost and time. The HLSM approach framework has been implemented into a prototype
computer-based tool named ‘Foresight of Emotional and Direct Effects’ (FEDE).
The HLSM was evaluated by product development stakeholders from both industry and academia.
The main contribution of this research is the HLSM approach which supports decision makers by
providing knowledge of emotional consequences and their effects on business metrics. The
evaluation results show that knowledge of emotional consequences and the effect on business
metrics is novel and provides new decision-making opportunities.
Description: PH.D2017-01-01T00:00:00ZInvestigation of miniature lithium-bromide/water absorption refrigeration systems
/library/oar/handle/123456789/70807
Title: Investigation of miniature lithium-bromide/water absorption refrigeration systems
Abstract: Nowadays, due to the global demand for the reduction of energy usage and the
use of harmful refrigerants which are associated with vapour compression refrigeration
systems, alternative cooling means, like the Lithium-Bromide/Water (LiBr/H2O)
absorption refrigeration system, are being investigated and produced in developed
countries. However, the majority of these LiBr/H2O absorption refrigeration systems,
which are available on the market, have a large cooling capacity. In fact, there is little
literature related to miniature LiBr/H2O absorption refrigeration systems with small
cooling capacities. This is because of the difficulties encountered during the design and
operation of such systems (such as crystallization of the Lithium-Bromide/Water
solution, choosing the appropriate equipment, and dimensioning of the components for
compactness, etc.). Therefore, this research focuses specifically on the development of
mathematical design models and experimental work that provide a successful
description of the phenomenon of the absorption rate for a system with a small cooling
capacity.
For this reason, a miniature LiBr/H2O absorption refrigeration system
equipped with an adiabatic absorber was designed and constructed, having a cooling
capacity of 45 𝑊 at 10 ℃, which is also the minimum system temperature. A thermal
analysis consisting of mass and energy balances was made for a range of generator and
adiabatic absorber temperatures. This analysis enabled the optimum coefficient of
performance (COP) to be found and recommended components’ temperatures for the
absorption refrigeration system without a solution heat exchanger. The decision not to
include a solution heat exchanger was taken in order to keep the system as simple as
possible.
Thereafter, the sizing of the system heat exchangers was made to accommodate
this optimum COP and corresponding temperatures. The maximum temperature of the
system was set by the generator at 80 ℃. The designed heat input in the generator was
69.2 𝑊. The design of the system and individual components is presented and
explained. This includes the design of the helical coil condenser operating at 35 ℃, and the design of the adiabatic absorber operating at 30 ℃. The optimal exposed surface
area of the LiBr/H2O solution to the vapour refrigerant (vapour-solution interface area)
inside the adiabatic absorber was determined experimentally and found to be equal to
140 𝑐𝑚2. The most challenging part of the design was estimating the heat transfer
coefficients present in the various heat exchangers.
Description: PH.D2017-01-01T00:00:00ZModelling the self-induced cycle-to-cycle variations in the aerodynamic blade loads of a yawed wind turbine
/library/oar/handle/123456789/70739
Title: Modelling the self-induced cycle-to-cycle variations in the aerodynamic blade loads of a yawed wind turbine
Abstract: In the complex wind flow environment, horizontal axis wind turbines (HAWTs)
experience three dimensional rotational and unsteady aerodynamic phenomena at the
rotor blades sections. These highly unsteady three dimensional effects have a dramatic
impact on the flow field close to a HAWT rotor, the aerodynamic load distributions on
the blades, and the wake development downstream of the rotor. Unfortunately, there is
still an incomplete understanding of the flow physics governing unsteady flow
conditions, and hence the current theoretical models are often incapable of modelling
the impact realistically. On the other hand, physical modelling of the wind turbine
systems considering solely the average behaviour of the design variables and physical
constants in the design process eliminates the underlining physics associated with the
real dynamics of the system. These are characterised in the effects of the unstable
process of dynamic stall vortex kinematics and the unsteady wake phenomena occurring
in the close proximity of the rotor, amongst others. In this Ph.D. thesis, a different
approach is considered for the effects of the cycle-to-cycle variations in the
aerodynamic loads over multiple rotor rotations (cycles) for yawed rotors operating in a
uniform and steady wind flow. This could enable new insight on modelling the direct
influence of the blade on the three-dimensional flow.
Description: PH.D2017-01-01T00:00:00ZRegistration of thermographic video for dynamic temperature analysis in humans
/library/oar/handle/123456789/29523
Title: Registration of thermographic video for dynamic temperature analysis in humans
Abstract: The use of infrared thermography in medical applications has increased in popularity
in recent years. It facilitates the detection and examination of skin thermal signatures,
under both normal and abnormal conditions. Thermography has been employed in
numerous biomedical fields, including breast cancer detection, cutaneous temperature
monitoring during exercise and the analysis of normative temperature patterns.
Thermal imaging may be dynamic or static in nature. Using static thermography, the
steady state conditions and spatial distributions of the thermal patterns within a target
are analysed at a particular instant, usually following an acclimatisation period. In
contrast, via dynamic thermography, both spatial and temporal variations are
considered, making the acquired data more informative. However, issues including
involuntary target movement and the dynamic temperature changes undergone by the
target need to be considered.
Video registration was opted for in this work. Four steps constitute the registration
process. The Speeded-Up Robust Features (SURF) detector was utilised in the feature
detection stage. Matching features between images were then found based on the sum
of squared differences (SSD) error, following which an affine geometric
transformation was computed to adequately map the images in consideration. Bilinear
interpolation was then utilised to calculate pixel values in non-integer coordinates.
Two video registration methods were proposed in this work to address the primary
issues associated with dynamic thermography. Data was gathered from nine
participants for the testing of these methods. Following implementation, their
performance was assessed both qualitatively and quantitatively, and a two-sample ttest
was applied to verify that the difference between the mean errors per method was
statistically significant.
Dynamic temperature analysis was also carried out on the extracted temperature data
in both the time and frequency domains, where cyclic patterns having different
frequencies and magnitudes were observed across all participants. Such behaviour has
not been documented in literature thus far, which implies that the biological
significance of these patterns is yet to be determined.
Description: B.ENG.(HONS)2017-01-01T00:00:00Z