Regression and hypothesis tests for multivariate GNSS state time series

A satellite based observation system can continuously or repeatedly generate a user state vector time series that may contain useful information. One typical example is the collection of International GNSS Services (IGS) station daily and weekly combined solutions. Another example is the epoch-by-epoch kinematic position time series of a receiver derived by a GPS real time kinematic (RTK) technique. Although some multivariate analysis techniques have been adopted to assess the noise characteristics of multivariate state time series, statistic testings are limited to univariate time series. After review of frequently used hypotheses test statistics in univariate analysis of GNSS state time series, the paper presents a number of T-squared multivariate analysis statistics for use in the analysis of multivariate GNSS state time series. These T-squared test statistics have taken the correlation between coordinate components into account, which is neglected in univariate analysis. Numerical analysis was conducted with the multi-year time series of an IGS station to schematically demonstrate the results from the multivariate hypothesis testing in comparison with the univariate hypothesis testing results. The results have demonstrated that, in general, the testing for multivariate mean shifts and outliers tends to reject less data samples than the testing for univariate mean shifts and outliers under the same confidence level. It is noted that neither univariate nor multivariate data analysis methods are intended to replace physical analysis. Instead, these should be treated as complementary statistical methods for a prior or posteriori investigations. Physical analysis is necessary subsequently to refine and interpret the results.

Application of multi-criteria decision making methods to compression ignition engine efficiency and gaseous, particulate and greenhouse gas emissions

Compression ignition (CI) engine design is subject to many constraints which presents a multi-criteria optimisation problem that the engine researcher must solve. In particular, the modern CI engine must not only be efficient, but must also deliver low gaseous, particulate and life cycle greenhouse gas emissions so that its impact on urban air quality, human health, and global warming are minimised. Consequently, this study undertakes a multi-criteria analysis which seeks to identify alternative fuels, injection technologies and combustion strategies that could potentially satisfy these CI engine design constraints. Three datasets are analysed with the Preference Ranking Organization Method for Enrichment Evaluations and Geometrical Analysis for Interactive Aid (PROMETHEE-GAIA) algorithm to explore the impact of 1): an ethanol fumigation system, 2): alternative fuels (20 % biodiesel and synthetic diesel) and alternative injection technologies (mechanical direct injection and common rail injection), and 3): various biodiesel fuels made from 3 feedstocks (i.e. soy, tallow, and canola) tested at several blend percentages (20-100 %) on the resulting emissions and efficiency profile of the various test engines. The results show that moderate ethanol substitutions (~20 % by energy) at moderate load, high percentage soy blends (60-100 %), and alternative fuels (biodiesel and synthetic diesel) provide an efficiency and emissions profile that yields the most “preferred” solutions to this multi-criteria engine design problem. Further research is, however, required to reduce Reactive Oxygen Species (ROS) emissions with alternative fuels, and to deliver technologies that do not significantly reduce the median diameter of particle emissions.

Explaining Pathe's global dominance in the pre-Hollywood film industry

For almost a decade before Hollywood existed, French firm Pathe towered over the early film industry with estimates of its share of all films sold around the world varying between 50-70%. This paper analyses Pathe’s rise to market leadership by applying a theoretical framework drawn from the business literature on causes of industry dominance, that provides insights into how firms acquire and maintain market dominance. This paper uses evidence presented by film historians to argue that Pathe “fits” the expected theoretical model of the dominant firm because it had a marketing orientation, used an effective quality- based competitive strategy and possessed the six critical strategic marketing capabilities that business research shows enable the best performing firms to consistently outperform rivals.

Regional characteristics, opportunity perception and entrepreneurial activities

This paper seeks to better understand the link between regional characteristics and individual entrepreneurship. We combine individual-level GEM data for Western Germany with regional-level data, using multi-level analysis to test our hypotheses. We find no direct link between regional knowledge creation, the economic context and an entrepreneurial culture on the one side and individual business start-up intentions and start-up activity on the other side. However our findings point to the importance of an indirect effect of regional characteristics as knowledge creation, the economic context and an entrepreneurial culture have an effect on the individual perception of founding opportunities which in turn predicted start-up intentions and activity.

Which cultural values matter to business process management? Results from a global Delphi study

Purpose – Business process management (BPM) requires a holistic perspective that includes managing the culture of an organization to achieve objectives of efficient and effective business processes. Still, the specifics of a BPM-supportive organizational culture have not been examined so far. Thus, the purpose of this paper is to identify the characteristics of a cultural setting supportive of BPM objectives. Design/methodology/approach – The paper examines the constituent values of a BPM-supportive cultural setting through a global Delphi study with BPM experts from academia and practice and explore these values in a cultural value framework. Findings – The paper empirically identifies and defines four key cultural values supporting BPM, viz., customer orientation, excellence, responsibility, and teamwork. The paper discusses the relationships between these values and identifies a particular challenge in managing these seemingly competing values. Research limitations/implications – The identification and definition of these values represents a first step towards the operationalization (and empirical analysis) of what has been identified as the concept of BPM culture, i.e. a culture supportive of achieving BPM objectives. Practical implications – Identifying these cultural values provides the basis for developing an instrument that can measure how far an existing cultural context is supportive of BPM. This, in turn, is fundamental for identifying measures towards achieving a BPM culture as a necessary, yet not sufficient means to obtain BPM success. Originality/value – The paper examines which cultural values create an environment receptive for BPM and, thus, specifies the important theoretical construct BPM culture. In addition, the paper raises awareness for realizing these values in a BPM context.

Ammonia emissions from a representative in-use fleet of vehicles in Guangzhou

Emission rates of ammonia (NH3) are reported for a fleet of 130 light-, medium-, and heavy-duty vehicles recruited in Guangzhou, China. NH3 measurements were performed using Nessler's Reagents spectrophotometry and nationwide standard chassis dynamometer test cycles required by Chinese EPA. Emissions of CO and NOx were also measured during these test cycles. Emission factors of NH3 were calculated for each type of vehicle and used to estimate the total emissions of NH3 from motor vehicles in Guangzhou (GZ) in 2009. Emission factors of NH3 show large variations among different categories of vehicles, with a range from 4 to 138 mg km-1. The average emissions of NH3 in Guangzhou in 2009 were estimated to be 983 t, with a range from 373 to 2136 t. In addition, it was found that vehicles with the highest NH3 emission rates possess the following characteristics: mediumand heavy-duty vehicles, certified with out-of-date emission standards, mid-range odometer readings, and higher CO and NOx emission rates. The results of this study will be useful for developing NH3 emissions inventories in Guangzhou and other urban areas in China.

The construction contract bidder homogeneity assumption : an empirical test

This paper describes an empirical study to test the proposition that all construction contract bidders are homogeneous ie. they can be treated as behaving collectively in an identical (statistical) manner. Examination of previous analyses of bidding data reveals a flaw in the method of standardising bids across different size contracts and a new procedure is proposed which involves the estimation of a contract datum. Three independent sets of bidding data were then subjected to this procedure and estimates of the necessary distributional parameters obtained. These were then tested against the bidder homogeneity assumption resulting in the conclusion that the assumption may be appropriate for a three parameter log-normal shape, but not for scale and location.

The distribution of construction project bids

This paper describes an analysis of construction project bids to determine (a) the global distribution and (b) factors influencing the distribution of bids. The global distribution of bids was found, by using a battery of ll test statistics, to be approximated by a three-parameter log normal distribution. No global spread parameter was found. A multivariate analysis revealed the year of tender to be the major influencing factor. Consideration of the construction order, tender price and output indices lead to the conclusion that distributional spread reflected the degree of difference in pricing policies between bidders and the skewness of the distributions reflected the degree of competition. The paper concludes with a tentative model of the causal relationships between the factors and distributional characteristics involved.

Board age and gender diversity : a test of competing linear and curvilinear predictions

We test competing linear and curvilinear predictions between board diversity and performance. The predictions were tested using archival data on 288 organizations listed on the Australian Securities Exchange. The findings provide additional evidence on the business case for board gender diversity and refine the business case for board age diversity.

Conceptual model linking knowledge management with organisational performance

Better management of knowledge assets has the potential to improve business processes and increase productivity. This fact has led to considerable interest in recent years in the knowledge management (KM) phenomenon, and in the main dimensions that can impact on its application in construction. However, a lack of a systematic way of assessing KM initia-tives’ contribution towards achieving organisational business objectives is evident. This paper describes the first stage of a research project intended to develop, and empirically test, a KM input-process-output framework comprising unique and well-defined theoretical constructs representing the KM process and its internal and external determinants in the context of con-struction. The paper presents the underlying principles used in operationally defining each construct through the use of extant KM literature. The KM process itself is explicitly mod-elled via a number of clearly articulated phases that ultimately lead to knowledge utilisation and capitalisation, which in turn adds value or otherwise to meeting defined business objec-tives. The main objective of the model is to reduce the impact of subjectivity in assessing the contribution made by KM practices and initiatives toward achieving performance improvements.

Sleeping Beauty : global advertising self regulation awakens

The system of self regulation of advertising in mass-media was a dream scenario. If stakeholders complained and the advertisement was deemed offensive by an expert panel, it was an easy matter to withdraw the advertisement from mass media and from public attention. This was done locally, according to the cultural values and aesthetics of the population and the mandate of the self regulation board. To advertising regulators, the internet became their worst nightmare. The system of self regulation was no longer closed, and could be circumvented by placing the offending advertisements online. The system of self regulation was also no longer local, but global. All internet users had access to the same advertisements, regardless of cultural considerations. The awakening of global advertising self regulation is something that demands discussion. It is of value to all conference goers of AAA 2010 Europe, as it affects all advertising academics and all stakeholders in the advertising process. As the leading advertising body seeking to bring global advertising issues to a new venue in Europe, the AAA 2010 European Conference seems ripe for a special session on advertising self regulation. This is especially true as the panel contributes a European, US and Asia-Pacific viewpoint.

Steps toward the validation of the Trendelenburg Test : the effect of experimentally reduced hip abductor muscle function on frontal plane mechanics

Objective: To investigate the validity of the Trendelenburg test (TT) using an ultrasound-guided nerve block (UNB) of the superior gluteal nerve and determine whether the reduction in hip abductor muscle (HABD) strength would result in the theorized mechanical compensatory strategies measured during the TT. Design: Quasi-experimental. Setting: Hospital. Participants: Convenience sample of 9 healthy men. Only participants with no current or previous injury to the lumbar spine, pelvis, or lower extremities, and no previous surgeries were included. Interventions: Ultrasound-guided nerve block. Main Outcome Measures: Hip abductor muscle strength (percent body weight [%BW]), contralateral pelvic drop (cPD), change in contralateral pelvic drop (Delta cPD), ipsilateral hip adduction, and ipsilateral trunk sway (TRUNK) measured in degrees. Results: The median age and weight of the participants were 31 years (interquartile range [IQR], 22-32 years) and 73 kg (IQR, 67-81 kg), respectively. An average 52% reduction of HABD strength (z = 2.36, P = 0.02) resulted after the UNB. No differences were found in cPD or Delta cPD (z = 0.01, P = 0.99, z = 20.67, P = 0.49, respectively). Individual changes in biomechanics showed no consistency between participants and nonsystematic changes across the group. One participant demonstrated the mechanical compensations described by Trendelenburg. Conclusions: The TT should not be used as a screening measure for HABD strength in populations demonstrating strength greater than 30% BW but should be reserved for use with populations with marked HABD weakness. Clinical Relevance: This study presents data regarding a critical level of HABD strength required to support the pelvis during the TT.