Hard, soft or lean? Planning on medium size construction projects

In a paper presented to the 11th Annual ARCOM Conference, Johansen examined the way that managers and planners in medium sized construction projects plan in a flexible manner. This was termed "soft planning" and contrasted with the textbook approach which was termed "hard" planning. The fundamental components of hard planning are firm dates and critical activities. The reality was found to be quite different from the textbook approach. (Johansen, 1996a) The conclusion then, was that methods of soft planning methodologies should be developed to support what was actually happening. Here this conclusion is revised in the light of lean production concepts. After defining these concepts, the authors consider how they can affect the development of planning theories in construction; in particular, how concepts such as “shielding”, “lookahead planning” and “last planner” can allow managers to overcome the barriers to hard planning

Implementing lean: UK culture and systems change

For the IGLC 12 Conference the authors reported the results of implementing Last PlannerTM methods with a large UK contracting company. The projects studied demonstrated some success but also some cultural, organizational and systemic barriers to its effective implementation. Alarcon and Conte’s White Paper for the IGLC11 conference discussed these issues and invited researchers to consider them. In response, the authors have reflected upon and critically re-analysed the research as a means to refocus their future work in implementing Lean Construction methods in UK construction. Based on a review of the literature on construction culture we have identified theoretical factors that, together with Alarcon and Conte's list of critical organizational elements, provide a framework against which the results of the research have been considered. We conclude that the implementation of Last Planner was hindered by not fully considering cultural, organizational and systemic problems and by failing to recognize how deepseated these problems could be. We intend, in future projects, to take a more considered, and wider approach to Lean Construction (possibly using the LCI’s Lean Project Delivery System) and to focus our attention upon construction ventures where efforts at culture change have already started - in particular, where strategic partnering arrangements are in place

The lack of design quality focus in construction: a case for examining suitable design processes

A large number of projects in UK construction now involve contractor-led design and are thus very different from the traditional approach which formed the basis of the original Royal Institute of British Architects (RIBA) Outline Plan of Work. Such integrated and contractor-led approaches support the reform agenda of the late 1990s that was introduced to tackle process inefficiency. However, within the design professions there has been concern that this resulted in buildings that were designed-down to a cost rather than designed-up to a value. An attempt to address this resulted in the formation of the Commission for Architecture and Built Environment (CABE) in 1999 and the launch, in 2003, of the Design Quality Indicator (DQI) which measures how well a building satisfies stakeholders. This paper presents the early phases of doctoral research which will examine the impact of integrated design management approaches upon Design Quality

The Properties of Model Selection when Retaining Theory Variables

Economic theories are often fitted directly to data to avoid possible model selection biases. We show that embedding a theory model that specifies the correct set of m relevant exogenous variables, x{t}, within the larger set of m+k candidate variables, (x{t},w{t}), then selection over the second set by their statistical significance can be undertaken without affecting the estimator distribution of the theory parameters. This strategy returns the theory-parameter estimates when the theory is correct, yet protects against the theory being under-specified because some w{t} are relevant.Model selection, theory retention

Selecting a Regression Saturated by Indicators

We consider selecting a regression model, using a variant of Gets, when there are more variables than observations, in the special case that the variables are impulse dummies (indicators) for every observation. We show that the setting is unproblematic if tackled appropriately, and obtain the finite-sample distribution of estimators of the mean and variance in a simple location-scale model under the null that no impulses matter. A Monte Carlo simulation confirms the null distribution, and shows power against an alternative of interest.indicators; regression saturation; subset selection; model selection

Implementation of Improved EDC Combustion Model in the Open LES Code FDS

In this thesis, Magnussen’s and Hjertager’s Eddy Dissipation Concept (EDC) Combustion Model has been implemented in the CFD code Fire Dynamics Simulator (FDS). FDS is an open source non-commercial Large Eddy Simulation (LES) code mainly developed by the National Institute of Standards and Technology (NIST). EDC is developed for Reynolds Avarage Navier Stokes (RANS) equations where fluctuating values caused by turbulence are modeled. The reaction rate in EDC is predicted by RANS quantities such as Turbulent Kinetic Energy (TKE) and Dissipation of Turbulent Kinetic Energy, which is not solved explicitly in LES codes. A promising extension of EDC to LES was proposed Panjwani et al. treating eddy viscosity and strain rate instead. In their validation work a model constant was established for jet flames for the Smagorinsky turbulence model. However, the main purpose of FDS is studying smoke spread, fire detection and smoke ventilation in building fires. Such fires involves low Mach number flows driven by buoyancy, in contrast to jet fire that are strongly influenced by the momentum fuel release and are highly turbulent. The first motivation of this thesis has been to implement LES-EDC in FDS, and second to establish a model constant for buoyancy driven fires and evaluate whether a static constant is sufficient or a dynamic constant is necessary. This is solved by validate the code against velocity profiles in Sandia plume experiments, Heskestad flame height correlation, McCaffery centerline temperature and velocity correlation. Results are also compared with the existing combustion model in FDS for the default turbulence model, Deardorff, in the unofficial version 6. Experiments with square pipes inserted in the persistent flame region were performed at Lund University. Particle Image Velocimetry (PIV) technique was applied to measure the velocity vector field above the pipes. The goal was to study the affected of generated turbulence from the pipes and perhaps be able to investigate how the turbulence effected the LES-EDC model constant. Unfortunately, the experiments gave unsatisfactory results for CFD validation. During the experiments it was some technical problems with the shutter on the camera occurred as well as the seeding of particles turned out to be quite challenging. Therefore, this part of the thesis must be regarded as a contribution to the project Prediction and validation of pool fire developed in enclosures by means of CFD models for risk assessment of nuclear power plants which the experiments were linked up to, and not validation of FDS-EDC. Amodel constant of 0.015 gave satisfactory results for all the chosen validation cases. But a somewhat smaller constant is preferable for the centerline temperature and velocity profiles in the McCaffery simulations. With CLES = 0.015 the maximum temperature i over estimated. The slope change in flame height around Q* ≈ 1 was not captured by the Vreman and Deardorff turbulence model. The already existing combustion had the same difficulties. LES-EDC with the Smagorinsky model in addition to the existing combustion did also capture the dip for vertical velocity profile in the Sandia plume experiment test 17. But the disadvantage with the Smagorinsky model is the CPU clock times compared with the two other turbulence models. The errors of the implemented code (referred as FDS-EDC) are in most cases less or the same as for the existing model. The models are also about the same computational expensive. In contrast to the existing model, the implemented code is strongly grid dependent. So before FDS-EDC can be applied in fire analysis the model must be modified to be grid independent. A dynamic constant is not necessary for buoyancydriven fires in fire engineering application but a more accurate constant is recommended to be established. Temperature and velocity should in further work be validated in a wider range of Q* for practical fire sizes than in this thesis.MAMN-PROPRO39

The impact of strategy on ICT projects

Strategic planning processes are oriented towards the selection of objectives and product/market choices by senior management. From this viewpoint strategic planning provides a mechanism for setting and reviewing objectives, focusing on choices of long-term significance, identifying strategic options, allocating resources, and achieving corporate-wide co-ordination, monitoring, and control. Current literature on strategic planning has recognised the problems with traditional approaches to planning. In this article, the authors seek to consider links between strategy and the implementation of ICT projects within the telecommunications industry

A nuclear-derived proteinaceous matrix embeds the microtubule spindle apparatus during mitosis

The concept of a spindle matrix has long been proposed. Whether such a structure exists, however, and what its molecular and structural composition are have remained controversial. In this study, using a live-imaging approach in Drosophilasyncytial embryos, we demonstrate that nuclear proteins reorganize during mitosis to form a highly dynamic, viscous spindle matrix that embeds the microtubule spindle apparatus, stretching from pole to pole. We show that this “internal” matrix is a distinct structure from the microtubule spindle and from a lamin B–containing spindle envelope. By injection of 2000-kDa dextran, we show that the disassembling nuclear envelope does not present a diffusion barrier. Furthermore, when microtubules are depolymerized with colchicine just before metaphase the spindle matrix contracts and coalesces around the chromosomes, suggesting that microtubules act as “struts” stretching the spindle matrix. In addition, we demonstrate that the spindle matrix protein Megator requires its coiled-coil amino-terminal domain for spindle matrix localization, suggesting that specific interactions between spindle matrix molecules are necessary for them to form a complex confined to the spindle region. The demonstration of an embedding spindle matrix lays the groundwork for a more complete understanding of microtubule dynamics and of the viscoelastic properties of the spindle during cell division

Teaching the Ethics of Biology

Discusses the basic principles of ethics and ethical decision making as applied to biology. Ethical issues associated with biology; Theoretical basis of ethical decision-making; Models of ethical decision-making; Social implications of scientific experimentation and discovery