55 research outputs found
The impact of strategic decisions on construction client satisfaction : an assessment framework
For some considerable time, client satisfaction has been a problematic issue in the UK construction industry with many projects failing to satisfy the client needs and meet or exceed the client expectations. Client satisfaction is, however, a key performance measure and a major determinant of project success. There is a common belief that strategic decisions made by clients have a significant impact on the levels of client satisfaction. Strategic decisions in the context of construction projects are often associated with project stages including pre-design, design, tender, construction, occupancy & maintenance and disposal and vary in nature. Consequently the impact of strategic decisions on client satisfaction depends as much on timing as on the subjects of the decisions. While such findings are useful to facilitate the industry’s focus on addressing the failure in achieving client satisfaction, and point to the route for improvement, they are arbitrary and do not provide a systematic basis for investigating the real impact on client satisfaction. The nature of strategic decisions and the significance of its impact on client satisfaction have not been clearly identified and client satisfaction has remained an elusive issue for a majority of construction professionals. This research was hence undertaken to seek empirical evidence of an interrelationship between strategic decisions and client satisfaction. Defining strategic decisions, often associated with project stages, as ones that are complex and made under uncertainty and have a long-term impact on project success, a quantitative research methodology combined with qualitative approaches, was adopted in investigating the interrelationship between strategic decisions and client satisfaction. Findings of a detailed literature review revealed that client satisfaction at any stage depends as much on the service quality attributes of service providers including overall service delivery, people of service providers and communications with clients as on the influence of strategic decisions and the client itself. These performance attributes and the groups of strategic decisions, referred as strategic decision cluster (SDC), were further assessed and the relationships between these measures and strategic decisions were examined using factor analysis and multiple regression modelling techniques. Analyses revealed SDCs including Design Approach, Procurement and Implementation predict better the outcomes of service quality and hence higher levels of client satisfaction. Service delivery and communications with clients have a positively significant correlation with the levels of client satisfaction. Of these two attributes, communications with clients makes the largest unique contribution to the variance and is considered the better predictor for client satisfaction. The developed models is validated via external and internal validation and the findings support the thesis that strategic decisions have a impact on client satisfaction by strongly influencing the performance of service quality although causality cannot be assumed. It is recommended that service providers including contractors and consultants devote more efforts to improve their performance on the attributes of service quality identified as having significant association with client satisfaction, particularly service delivery and communications with clients. Further research efforts focusing on providing a practical tool or expert system so as to address the practical issues for a wider range of clients and service providers are also recommended.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Robustness of interdependent networks under targeted attack
When an initial failure of nodes occurs in interdependent networks, a cascade
of failure between the networks occurs. Earlier studies focused on random
initial failures. Here we study the robustness of interdependent networks under
targeted attack on high or low degree nodes. We introduce a general technique
and show that the {\it targeted-attack} problem in interdependent networks can
be mapped to the {\it random-attack} problem in a transformed pair of
interdependent networks. We find that when the highly connected nodes are
protected and have lower probability to fail, in contrast to single scale free
(SF) networks where the percolation threshold , coupled SF networks are
significantly more vulnerable with significantly larger than zero. The
result implies that interdependent networks are difficult to defend by
strategies such as protecting the high degree nodes that have been found useful
to significantly improve robustness of single networks.Comment: 11 pages, 2 figure
Percolation of partially interdependent networks under targeted attack
The study of interdependent networks, and in particular the robustness on
networks, has attracted considerable attention. Recent studies mainly assume
that the dependence is fully interdependent. However, targeted attack for
partially interdependent networks simultaneously has the characteristics of
generality in real world. In this letter, the comprehensive percolation of
generalized framework of partially interdependent networks under targeted
attack is analyzed. As and , the percolation law is
presented. Especially, when , , , the
first and second lines of phase transition coincide with each other. The
corresponding phase transition diagram and the critical line between the first
and the second phase transition are found. We find that the tendency of
critical line is monotone decreasing with parameter . However, for
different , the tendency of critical line is monotone increasing with
. In a larger sense, our findings have potential application for
designing networks with strong robustness and can regulate the robustness of
some current networks.Comment: 6 pages, 9 figure
Robustness of a Network of Networks
Almost all network research has been focused on the properties of a single
network that does not interact and depends on other networks. In reality, many
real-world networks interact with other networks. Here we develop an analytical
framework for studying interacting networks and present an exact percolation
law for a network of interdependent networks. In particular, we find that
for Erd\H{o}s-R\'{e}nyi networks each of average degree , the giant
component, , is given by
where is the initial fraction of removed nodes. Our general result
coincides for with the known Erd\H{o}s-R\'{e}nyi second-order phase
transition for a single network. For any cascading failures occur
and the transition becomes a first-order percolation transition. The new law
for shows that percolation theory that is extensively studied in
physics and mathematics is a limiting case () of a more general general
and different percolation law for interdependent networks.Comment: 7 pages, 3 figure
Percolation of Partially Interdependent Scale-free Networks
We study the percolation behavior of two interdependent scale-free (SF)
networks under random failure of 1- fraction of nodes. Our results are based
on numerical solutions of analytical expressions and simulations. We find that
as the coupling strength between the two networks reduces from 1 (fully
coupled) to 0 (no coupling), there exist two critical coupling strengths
and , which separate three different regions with different behavior of
the giant component as a function of . (i) For , an abrupt
collapse transition occurs at . (ii) For , the giant
component has a hybrid transition combined of both, abrupt decrease at a
certain followed by a smooth decrease to zero for as decreases to zero. (iii) For , the giant
component has a continuous second-order transition (at ). We find that
for , ; and for ,
decreases with increasing . In the hybrid transition, at the
region, the mutual giant component jumps
discontinuously at to a very small but non-zero value, and when
reducing , continuously approaches to 0 at for
for . Thus, the known theoretical
for a single network with is expected to be valid
also for strictly partial interdependent networks.Comment: 20 pages, 17 figure
Loading of ionic compounds into metal-organic frameworks: a joint theoretical and experimental study for the case of La³⁺
Crystalline{,} highly orientated surface-anchored MOF thin films{,} grown on Au substrates{,} were prepared using liquid-phase epitaxy (LPE). The successful loading of La3+ ions into the Cu3(BTC)2 (HKUST-1) SURMOFs (surface-mounted metal-organic frameworks) was monitored using X-ray diffraction (XRD). Theoretical calculations using classical force-field based Monte Carlo simulations yield a structure with two La3+ ions within the large Cu3(BTC)2 pores{,} in full agreement with experimental results on the composition of these films and the relative intensities of the XRD peaks. Implications of these findings for using MOF thin films for electronic applications are briefly discussed
PPTPF: Privacy-preserving trajectory publication framework for CDR mobile trajectories
10.3390/ijgi10040224ISPRS International Journal of Geo-Information10422
Al-13-pillared montmorillonite modified by cationic and zwitterionic surfactants: A comparative study
Electric transport properties of surface-anchored metal-organic frameworks and the effect of ferrocene loading
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