A power‐based leadership approach to project management

The concept of leadership relates to power structuring whereby the project leader may lead and motivate through power disposition. Power, in its diverse guises, combines interpersonal and structural elements and can be enhanced through political manoeuvring. Power may also be distributed unevenly between individuals in the project team. In this article a power‐based model of project leadership is developed, underpinned by a behaviour‐performance‐outcome approach and an appropriate methodology is developed for testing the construction enterprises in China using structural equations modelling. The fitness indices show that the resulting model which postulates that the motivational function of good leadership operates through managing power gaps by means of power‐sharing and power‐amassing is acceptable. The effects (both predominant magnitudes and statistical significance) from the project managers' referent power to power‐sharing and power‐amassing show that the project manager's inherent personal traits and credentials are critical to his/her power exercising so as to motivate members to secure management effectiveness.     

A bid‐unbalancing method for lowering a contractor's financial risk

A method is presented for unbalancing bids and optimizing the allocation of overall project profits to individual activities by considering the financial parameters of a project (bid mark‐up and projected cash flow), in conjunction with lowering the exposure to possible financial disorder in the project. The method utilizes the general concept of entropy and a variant of it (hereby termed ‘monetary entropy’, H _M) as measures of a project's perceived level of disorder, in order to distribute the total bid mark‐up to the project activities. The entropy‐based bid‐unbalancing method seeks to minimize a possible financial disorder (the monetary entropy) resulting from limited monetary resources available to the project and from badly developed project cash flows. The intended primary users of the method are contractors during the initial bidding stage of a project.     

Performance‐Based Contracting: an alternative approach to transacting in construction

Cost versus quality has often been presented as if it were a zero sum game — ‘If I gain in terms of quality then I will hare to lose in terms of the money I need to spend’.In reality most design teams would contend that this is not necessarily true but find that they lack the technique to evaluate the proper balance between cost and quality in order to achieve value for their client. This paper outlines the problem and a possible framework for investigating a marginal increase in design quality against cost at the critical stage before drawn information is provided.     

A case‐based reasoning approach to application of value engineering methodology in the construction industry

A key point in value engineering (VE) methodology is to acquire and apply knowledge of the assorted fields. An appropriate definition of VE expert knowledge flow could, therefore, yield more productive VE workshops. A conceptual expert case‐based reasoning (CBR) framework is introduced in this paper to form a coherent basis for the provision of practically suitable VE expert models. The proposed framework outlines knowledge entities and their relations in the VE workshop. The model benefits from a fuzzy approach to handle uncertainties in the evaluation phase of the methodology. In addition, a computer program is devised, based on the proposed framework, using Borland Delphi 7.0. It comprises an interface representing several phases of the VE job plan. The model is employed in a tunnelling project to demonstrate feasibility of the model in a practical workshop. Owing to its expert nature, the developed model contributes to efficiency of the methodology through providing VE teams with canalized expert knowledge of diverse domains. The propounded model may avail researchers in promoting expert models for pre‐construction and specifically VE studies in major construction projects.     

Quantification of wind‐driven rain — An experimental approach

Fernando Henriques of LNEC, Lisbon, considers the long‐term performance of buildings related to exposure conditions and presents the first year results of a study on driven rain.     

Planning for road pricing: A multi‐rationality approach

Road pricing has climbed high on the political agenda in several countries during the last decade. This can be attributed to a growing concern regarding urban congestion problems, environmental impact of traffic growth, and difficulties in financing new transport infrastructure. Nevertheless, examples of actual implementation are few. This may to a large degree be due to a restricted comprehension of the planning challenges that road pricing actually poses. Literature on transport planning and transport economics gives the basis for a definition of road pricing and a clarification of some emerging planning issues. Furthermore, planning for road pricing is here linked to contemporary planning theory by exploiting a “compound rationale for planning” proposed by Tore Sager and coupling this to pro and con arguments. The communicative elements of road pricing planning are exemplified and discussed, drawing especially on John Forester's theories of planning as argumentation.     

Extension of Mononobe–Okabe approach to unstable slopes

The resultant force of lateral earth pressure is commonly used in the design of nearly vertical walls while flatter slopes are designed to be internally stable using a factor of safety approach. An unstable slope is considered to have an unsatisfactory factor of safety unless supported by internal and/or external measures. However, from an analytical viewpoint, the distinction between walls and unstable slopes is unnecessary. Using a limit equilibrium analysis combined with a log spiral surface, a previous formulation is extended to deal with the pseudostatic instability of simple, homogeneous, cohesionless slopes. Hence, the original approach by Mononobe–Okabe (M–O) is extended to yield the resultant lateral force needed to stabilize an unstable slope. Given the slope angle, the design internal angle of friction, the backslope, the surcharge, the vertical and horizontal seismic coefficients, and the inclination of the resultant force, one can calculate the magnitude of this resultant force. The approach allows for the selection of a rational inclination of the resultant for cases where soil-face interaction is likely to develop along vertical segments only. The approach generalizes Coulomb’s (static) and M–O (pseudostatic) methods as all are in the same framework of limit equilibrium. While all methods yield identical results for vertical slopes, where the critical slip surface defining the active wedge degenerates to the same planar surface, the presented approach becomes more critical for flatter unstable slopes where the active wedge is augmented by a curved surface. Hence, the seamless extension of the M–O approach is produced.     

Uncertainty analysis in structural number determination in flexible pavement design—a convex model approach

The AASHTO Guide for Design of Pavement Structures uses a structural number as one of the major inputs for flexible pavement thickness design. Previous studies have shown that the layer coefficients, which are a component of the structural number, have variability. The use of these values without a strong consideration of their variability can influence the overall determination of the structural number, hence, the thickness of the pavement. This paper proposes to use convex models as a tool for addressing the variability and uncertainty in the structural number determination. The convex models provide a completely non-probabilistic representation of uncertainty. The uncertainty is treated as unknown-but-bounded. The approach is illustrated by an example.     

Loan‐to‐value ratios in Sweden. The impact of financial deregulation

We ask how financial deregulation in Sweden during the 1980s affected housing finance by studying data on loan‐to‐value (LTV) ratios for home owners who moved recently. Accounting for the impact of demographic and economic determinants we find that LTV ratios were higher between 1985 and 1987 than in earlier and later years. This time pattern suggests that the deregulation of the mortgage institutions and the removal of the loan rate ceiling on banks in 1983 and 1984 were more important than abolishment of the bank loan ceiling in late 1985. They also indicate a decrease in loan demand and/or supply as early as 1988, i.e., well before the banking crisis.     

Delays to Large Construction Projects in Ghana： A Risk Overview

Delay to large scale projects, which is as a result of actions or inactions of some project stakeholders, is becoming a global phenomena and Ghana is no exception. The objective of the research is to identify, rate and rank the most significant risk factors that causes delay on projects and examine the social impact of these delays to recommend modalities to help mitigate these risk factors. The study adopted quantitative methods with the distribution of 144 questionnaires to built environment professionals receiving a response rate of 75.7%. The instrument listed 58 common factors under eight categories that contribute to the causes of delay for respondents to rate. Analysis of data non-parametric test revealed that client, contractor, material and finance category factors significantly resulted in the schedule delay of large infrastructural projects. The survey analysis revealed that micro-factors that result in delays to large construction projects are time constraint, cost overrun, payment problems, dispute and litigation. The research recommended the following modalities to minimize such delays： availability of resources, improved communication and coordination, proper scope definition and feasibilities, utilization of modern technology, appropriate application of technologically based systems and competent project management＇s structures.     

A computational approach to ‘The Image of the City’

In The Image of the City Lynch describes how individuals perceive and recall features in urban spaces. The most distinctive elements in the urban landscape - categorised in paths, nodes, edges, districts and landmarks - give shape to individuals' mental representation of the city. Lynch’s approach has stimulated research into spatial cognition, urban design and artificial intelligence, and it still represents an essential pillar in the analysis of urban dynamics. Nevertheless, an explicit link between The Image of the City and GIScience has not been completely explored yet. In this paper, a computational approach to The Image of the City is proposed. Different perspectives in spatial cognition and GIS research are integrated to obtain a complete Image of the City, in which the most salient elements are shared by a large part of citizens. Nodes, paths and districts were identified through network science techniques. Methods drawn from the information approach to The Image of the City are used to detect landmarks, integrating the complexity of points of reference in their visual, structural and semantic components, as conceptualised by Lynch and successive research. The methods were applied to the central area of Boston and built using freely available spatial datasets. Results were compared to Lynch’s maps to evaluate the methodology: besides a considerable discrepancy with regard to landmarks, a good correspondence for paths, nodes, edges and districts was found.     

The coal cleat system： A new approach to its study

After a general analysis regarding the concept of coal ＂cleat system＂, its genetic origin and practical applications to coalbed methane （CBM） commercial production and to C02 geological sequestration projects, the authors have developed a method to answer, quickly and accurately in accordance with the industrial practice and needs, the following yet unanswered questions： （1） how to define the spatial orientation of the different classes of cleats presented in a coal seam and （2） how to determine the frequency of their connectivites. The new available and presented techniques to answer these questions have a strong computer based tool （geographic information system, GIS）, able to build a complete georeferentiated database, which will allow to three-dimensionally locate the laboratory samples in the coalfield. It will also allow to better understand the coal cleat system and consequently to recognize the best pathways to gas flow through the coal seam. Such knowledge is considered crucial for understanding what is likely to be the most efficient opening of cleat network, then allowing the injection with the right spatial orientation, of pressurized fluids in order to directly drain the maximum amount of gas flow to a CBM exploitation well. The method is also applicable to the CO2 geological sequestration technologies and operations corresponding to the injection of CO2 sequestered from industrial plants in coal seams of abandoned coal mines or deep coal seams.     

Explosive construction in a micro‐state: environmental limit and the Bon curve: evidence from North Cyprus

The dynamo role of the construction sector in North Cyprus is documented on the basis of an empirical estimation of backward and forward linkages during the period 1998 to 2005. This was a period when the North Cyprus economy experienced an economic boom in the aftermath of the UN Peace Plan known as the Annan Plan for settling the Cyprus problem. The latest input–output table for the North Cyprus economy is 1998 and we had to derive backward and forward linkages for 2005 from a detailed breakdown of inter‐industry transactions per unit of construction output using the most significant purchases and deliveries, normalizing these transactions for comparability between 2005 and 1998. The results reflect radically different pattern of inter‐industry transactions in 2005 compared to 1998. This work also has general interest in highlighting the possibility of a modified Bon curve for micro‐states, such as North Cyprus, in which environmental constraints may be encountered earlier implying an inverted V‐shaped Bon curve in place of an inverted U‐shape.     

A simplified approach to directly consider intact rock anisotropy inHoekeBrown failure criterion

Many rock types have naturally occurring inherent anisotropic planes, such as bedding planes, foliation,or flow structures. Such characteristic induces directional features and anisotropy in rocks＇ strength anddeformational properties. The HoekeBrown （HeB） failure criterion is an empirical strength criterionwidely applied to rock mechanics and engineering. A direct modification to HeB failure criterion toaccount for rock anisotropy is considered as the base of the research. Such modification introduced a newdefinition of the anisotropy as direct parameter named the anisotropic parameter （Kb）. However, thecomputation of this parameter takes much experimental work and cannot be calculated in a simple way.The aim of this paper is to study the trend of the relation between the degree of anisotropy （Rc） and theminimum value of anisotropic parameter （Kmin）, and to predict the Kmin directly from the uniaxialcompression tests instead of triaxial tests, and also to decrease the amount of experimental work.
2014 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.     

A ‘smart’ bottom-up whole-systems approach to a zero-carbon built environment

ABSTRACT

Since the energy crisis of the mid and late 1970s, society has been aware of the need for a built environment that uses less fossil fuel energy. Although the built environment accounts for a large proportion of global fossil fuel use, it may be argued that the energy and buildings agenda is not being addressed at the depth or scale needed to meet global and national CO₂ emission-reduction targets. Most actions to reduce energy use in the built environment have mainly used a ‘top-down’ decision-making approach, from government and industry, with little end-user engagement. Greenhouse gas emission-reduction targets will not be met without providing the technological and socio-economic pathways for achieving them. The paper is divided into three parts. Firstly, it discusses the need to reduce fossil fuel use and the apparent failure to transition policy goals and aims into practice. Secondly, top-down and bottom-up approaches are reviewed, advocating a greater emphasis on a ‘whole-system’ bottom-up approach in delivering multiple benefit solutions. Thirdly, the concept of ‘smart’ is considered in relation to bottom up with its implementation at a regional scale.     

A systems theoretic approach to second moment modelling of probabilistic engineering systems∗

A new approach to modelling probabilistic and stochastic engineering systems using graph theory is outlined. This approach emphasizes the introduction of probabilistic and stochastic concepts at the very beginning of the model building process. This is in marked contrast to past tendencies to add probabilistic concepts to the end of an otherwise deterministic model building process. The development of topological models founded on oriented probabilistic measurements is given. which leads to the identification of some useful statistical properties of the’ random interconnection equations’. The development of probabilistic component models is given, where a component can be characterized independently of other components. Methods for automatically building the second moment representation of the Mixed Nodal Tableau are discussed. The application of the above theory to the probabilistic analysis of a pipe network problem is briefly described.     

Valuation of multi‐stage BOT projects involving dedicated asset investments: a sequential compound option approach

The valuation of multi‐stage build‐operate‐transfer projects is not a trivial task. It needs to deal with uncertain project values in future expansions and the possibility of expansions or abandonment in the presence of project risks. The valuation problem becomes more difficult when multi‐stage projects require upfront and intermediate dedicated asset investments for future expansions. Dedicated asset investments may or may not create project values, depending on whether future expansions could be justified and realized. A sequential compound option model is proposed to tackle these important valuation issues.