Planning For Claims: An Ethnography of Industry Culture

Claims by contractors for additional payments have been identified by commentators as a major source of difficulty in the industry. Ethnographic research with industry members reveals some key features of planning practices that underlie such events. Claims are sometimes planned at tender stage and sometimes during the course of a project. One practice at tender stage is a pricing technique that minimizes the tender price while maximizing the out-turn cost of a contract by exploiting mistakes in the bill of quantities. Another is the programming of work to maximize its vulnerability to delay. More reactive techniques may be employed during the course of the project, often to make up for an unanticipated increase in costs. These and other similar practices may be reported as features of an integrated culture, defined in such a way as to encompass activity and reject Cartesian dualism. The unique adequacy requirements of methods are suitable criteria for the evaluation of such reports. The claims culture arises from economic conditions in the industry, which include low entry barriers and competitive tendering. However, removal of these conditions alone cannot guarantee that the practices will cease

Parameterizing by the Number of Numbers

The usefulness of parameterized algorithmics has often depended on what Niedermeier has called, "the art of problem parameterization". In this paper we introduce and explore a novel but general form of parameterization: the number of numbers. Several classic numerical problems, such as Subset Sum, Partition, 3-Partition, Numerical 3-Dimensional Matching, and Numerical Matching with Target Sums, have multisets of integers as input. We initiate the study of parameterizing these problems by the number of distinct integers in the input. We rely on an FPT result for ILPF to show that all the above-mentioned problems are fixed-parameter tractable when parameterized in this way. In various applied settings, problem inputs often consist in part of multisets of integers or multisets of weighted objects (such as edges in a graph, or jobs to be scheduled). Such number-of-numbers parameterized problems often reduce to subproblems about transition systems of various kinds, parameterized by the size of the system description. We consider several core problems of this kind relevant to number-of-numbers parameterization. Our main hardness result considers the problem: given a non-deterministic Mealy machine M (a finite state automaton outputting a letter on each transition), an input word x, and a census requirement c for the output word specifying how many times each letter of the output alphabet should be written, decide whether there exists a computation of M reading x that outputs a word y that meets the requirement c. We show that this problem is hard for W[1]. If the question is whether there exists an input word x such that a computation of M on x outputs a word that meets c, the problem becomes fixed-parameter tractable

FPT is Characterized by Useful Obstruction Sets

Many graph problems were first shown to be fixed-parameter tractable using the results of Robertson and Seymour on graph minors. We show that the combination of finite, computable, obstruction sets and efficient order tests is not just one way of obtaining strongly uniform FPT algorithms, but that all of FPT may be captured in this way. Our new characterization of FPT has a strong connection to the theory of kernelization, as we prove that problems with polynomial kernels can be characterized by obstruction sets whose elements have polynomial size. Consequently we investigate the interplay between the sizes of problem kernels and the sizes of the elements of such obstruction sets, obtaining several examples of how results in one area yield new insights in the other. We show how exponential-size minor-minimal obstructions for pathwidth k form the crucial ingredient in a novel OR-cross-composition for k-Pathwidth, complementing the trivial AND-composition that is known for this problem. In the other direction, we show that OR-cross-compositions into a parameterized problem can be used to rule out the existence of efficiently generated quasi-orders on its instances that characterize the NO-instances by polynomial-size obstructions.Comment: Extended abstract with appendix, as accepted to WG 201

A simple linear-time algorithm for finding path-decompositions of small width

We described a simple algorithm running in linear time for each fixed constant $k$, that either establishes that the pathwidth of a graph $G$ is greater than $k$, or finds a path-decomposition of $G$ of width at most $O(2^{k})$. This provides a simple proof of the result by Bodlaender that many families of graphs of bounded pathwidth can be recognized in linear time.Comment: 9 page

Obstructions to within a few vertices or edges of acyclic

Finite obstruction sets for lower ideals in the minor order are guaranteed to exist by the Graph Minor Theorem. It has been known for several years that, in principle, obstruction sets can be mechanically computed for most natural lower ideals. In this paper, we describe a general-purpose method for finding obstructions by using a bounded treewidth (or pathwidth) search. We illustrate this approach by characterizing certain families of cycle-cover graphs based on the two well-known problems: $k$-{\sc Feedback Vertex Set} and $k$-{\sc Feedback Edge Set}. Our search is based on a number of algorithmic strategies by which large constants can be mitigated, including a randomized strategy for obtaining proofs of minimality.Comment: 16 page

Climate change : a response surface study of the effects of CO2 and temperature on the growth of French beans

The possible impact of global rises in atmospheric CO2 concentration and temperature on the growth and development of French beans (Phaseolus vulgaris) was examined using growth cabinets. Five CO2 concentrations of 350, 450, 550, 650 and 750 vpm and five temperatures of 14·5, 15·5, 16·5, 17·5 and 18·5°C were tested using a fractional factorial design comprising nine treatment combinations of the two factors. Plants were grown under constant irradiance, common atmospheric humidities (vpd 0·5 kPa) and non-limiting supplies of water and mineral nutrients. The plant growth response was modelled by fitting polynomial response function curves to the times to first flower opening, first bean set, 50% maturity and the number and yield of beans. The effects of temperature were large and positive for most of the measured variables, whereas the effects of CO2 were small and negative or non-existent. Increased temperature substantially reduced the time to flowering and the time from bean set to 50% maturity and increased the number and yield of mature beans whereas increased CO2 concentration had little effect on plant growth except that bean yield was very slightly reduced. There was no significant evidence of interaction between the CO2 concentration effects and the temperature effects. The time to maturity and yield of mature beans was simulated for the 2020s (2010 to 2039) and the 2050s (2040 to 2069) using the fitted polynomial models and four climate change scenarios suggested by the UK Climate Impacts Programme. These simulations showed that, depending upon the assumed scenario, the 2020s yields could rise by 39–84% and time to maturity reduce by between 6 and 15 days whereas the 2050s yields could rise by 51–118% and time to maturity reduce by between 9 and 25 days

African Americans from Back Yonder : The Historical Archaeology of the Formation, Maintenance, and Dissolution of the American Enclave in Samaná, Dominican Republic

By the end of 1825, 6,000 African Americans had left the United States to settle in the free black Republic of Haiti. After arriving on the island, 200 immigrants formed an enclave in what is now Samaná, Dominican Republic. The Americans in Samaná continued to speak English, remained Protestant (in a country of devout Catholics), and retained American cultural practices for over 150 years. Relying on historical archaeological methods, this dissertation explores the processes of community formation, maintenance, and dissolution, while paying particular attention to intersections of race and nation. Fieldwork took place in the Spring and Summer of 2010 and involved local archival research, oral history interviews, and an aboveground survey of the cemetery in Samaná. Oral histories stemming from linguistic research conducted in the 1980s were also incorporated into this study. Analyses show that the geopolitical isolation of the Samaná Peninsula, in addition to the immigrants\u27 status as a large minority within a small but diverse population, allowed for the relatively unhindered formation of the American community. The immigrants and their descendants defined themselves in relation to the broader Samanesa population through their use of English, emphasis on a formal, English-language education for their children, their honesty and Protestant work ethic, and their devotion to God and their Methodist churches. Yet the 1930s, which saw the rise and adverse impact of the Trujillo regime, brought a series of changes to the town which led to the Americans\u27 diminished social status and eventual loss of community cohesion. Finally, the American enclave in Samaná is placed into a broader context; the impact on the community of the various racialized national projects with which it has contended is examined. In addition, the Americans in Samaná are then looked at as a case study in processes of transnationalism and globalization

Culture as a component of complexity in construction

W112 Culture in Construction: Paper ID: 798Both culture and construction have been suggested to be complex – culture as relating to, even governing, human behaviour and construction as a context in which human activities occur in the design, production, occupation, and use and disposal of major artefacts: buildings and infrastructure. Indeed, construction has been subject to various definitions and categorisations of complexity to assist analysis of the processes employed in the realisation and use of its outputs; including consideration of managerial and technical complexity. Historically, intuitive understanding of what constitute complex construction projects was supplemented with naïve objective measurements – such as the proportionate cost of building services. However, such approaches have failed to be very helpful in gaining understanding of the relationships between inputs to the realisations, the transformations within the processes and the resultant performance outputs. Following on from chaos theory, the emerging field of complexity theory, with its emphasis on linkages within systems and the ‘softer’ elements, has significant potential for providing insights. Hence, this paper examines culture in the context of and application to construction organisations and projects using the perspectives of complexity theory towards helping to determine a more detailed research agenda in the hope of gaining significantly greater understanding through this paradigm.postprintThe 2010 World Congress of CIB on Building a Better World, University of Salford, Salford, U.K., 10-14 May 2010. In Proceedings: TG59 and W112 - Special Track 18th CIB World Building Congress, 2010, p. 192-20

Addressing Issues across Organisational Boundaries in Construction Projects

Includes bibliographical references.The extensive and increasing specialisation in all sectors of the construction industry has prompted much criticism due to the common absence of sufficient coordination and collaboration of the separate organisations culminating in accusations that such fragmentation leads to poor performance.This paper focuses on the managerial issues which emerge due to the diversity of individual organisations which must be assembled to execute engineering construction projects. Managing any organisational interface is notoriously problematic and has prompted the generation oftheories concerning management of boundaries – including boundary spanning and boundary objects. This paper examines the theory, research perspectives and findings to date and relates them to the management of engineering construction projects. It is concluded that recognition of performance interdependence amongst project participants is an essential underpinning of cooperationand development and use of appropriate boundary management through boundary spanning and boundary objects can foster interaction and coordination even with participants‟ retention of their individual goals