973 resultados para Empirical Comparison


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Governments around the world are facing the challenge of responding to increased expectations by their customers with regard to public service delivery. Citizens, for example, expect governments to provide better and more efficient electronic services on the Web in an integrated way. Online portals have become the approach of choice in online service delivery to meet these requirements and become more customer-focussed. This study describes and analyses existing variants of online service delivery models based upon an empirical study and provides valuable insights for researchers and practitioners in government. For this study, we have conducted interviews with senior management representatives from five international governments. Based on our findings, we distinguish three different classes of service delivery models. We describe and characterise each of these models in detail and provide an in-depth discussion of the strengths and weaknesses of these approaches.

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In the study of traffic safety, expected crash frequencies across sites are generally estimated via the negative binomial model, assuming time invariant safety. Since the time invariant safety assumption may be invalid, Hauer (1997) proposed a modified empirical Bayes (EB) method. Despite the modification, no attempts have been made to examine the generalisable form of the marginal distribution resulting from the modified EB framework. Because the hyper-parameters needed to apply the modified EB method are not readily available, an assessment is lacking on how accurately the modified EB method estimates safety in the presence of the time variant safety and regression-to-the-mean (RTM) effects. This study derives the closed form marginal distribution, and reveals that the marginal distribution in the modified EB method is equivalent to the negative multinomial (NM) distribution, which is essentially the same as the likelihood function used in the random effects Poisson model. As a result, this study shows that the gamma posterior distribution from the multivariate Poisson-gamma mixture can be estimated using the NM model or the random effects Poisson model. This study also shows that the estimation errors from the modified EB method are systematically smaller than those from the comparison group method by simultaneously accounting for the RTM and time variant safety effects. Hence, the modified EB method via the NM model is a generalisable method for estimating safety in the presence of the time variant safety and the RTM effects.

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Sourcing funding for the provision of new urban infrastructure has been a policy dilemma for governments around the world for decades. This is particularly relevant in high growth areas where new services are required to support swelling populations. Existing communities resist the introduction of new taxes to fund such infrastructure, hence the introduction of charges to the developer has flourished. The Australian infrastructure funding policy dilemmas are reflective of similar matters to some extent in the United Kingdom, and to a greater extent the United States of America. In these countries, infrastructure cost recovery policies have been in place since the 1940’s and 1970’s respectively. There is an extensive body of theoretical and empirical literature that discusses the passing on (to home buyers) or passing back (to the englobo land seller) of these increased infrastructure charges, and the corresponding impact on housing cost and supply. The purpose of this research is to examine the international evidence that suggests infrastructure charges contribute to increased house prices as well as reduced land supply. The paper concludes that whilst the theoretical work is largely consistent, the empirical research to date is inconclusive and further research is required into these impacts in Australia.

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This study proposes a framework of a model-based hot spot identification method by applying full Bayes (FB) technique. In comparison with the state-of-the-art approach [i.e., empirical Bayes method (EB)], the advantage of the FB method is the capability to seamlessly integrate prior information and all available data into posterior distributions on which various ranking criteria could be based. With intersection crash data collected in Singapore, an empirical analysis was conducted to evaluate the following six approaches for hot spot identification: (a) naive ranking using raw crash data, (b) standard EB ranking, (c) FB ranking using a Poisson-gamma model, (d) FB ranking using a Poisson-lognormal model, (e) FB ranking using a hierarchical Poisson model, and (f) FB ranking using a hierarchical Poisson (AR-1) model. The results show that (a) when using the expected crash rate-related decision parameters, all model-based approaches perform significantly better in safety ranking than does the naive ranking method, and (b) the FB approach using hierarchical models significantly outperforms the standard EB approach in correctly identifying hazardous sites.

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Despite a general belief that incentive mechanisms can improve value for money during procurement and performance during project execution, empirical research on the actual effects is nascent. This research focuses on the design and implementation of incentive mechanisms in four different infrastructure projects: two road reconstructions in the Netherlands and two building constructions in Australia. Based on an analytical framework of key motivation drivers, a cross cases analysis is conducted in view of performance on the contract assumptions, selection phase, execution phase and project contract performance. It was identified that despite significant differences in the project characteristics, results indicate that they experience similar contextual drivers on the incentive effectiveness. High value was placed on risk allocation and relationship building in the selection and construction phase. The differences can be explained from both contextual and project related characteristics. Although there are limitations with this research in drawing generalizations across two sets of case projects, the results provide a strong base to explore the nature of incentive systems across different geographical and contextual boundaries in future research.

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The aim of this paper is to provide a comparison of various algorithms and parameters to build reduced semantic spaces. The effect of dimension reduction, the stability of the representation and the effect of word order are examined in the context of the five algorithms bearing on semantic vectors: Random projection (RP), singular value decom- position (SVD), non-negative matrix factorization (NMF), permutations and holographic reduced representations (HRR). The quality of semantic representation was tested by means of synonym finding task using the TOEFL test on the TASA corpus. Dimension reduction was found to improve the quality of semantic representation but it is hard to find the optimal parameter settings. Even though dimension reduction by RP was found to be more generally applicable than SVD, the semantic vectors produced by RP are somewhat unstable. The effect of encoding word order into the semantic vector representation via HRR did not lead to any increase in scores over vectors constructed from word co-occurrence in context information. In this regard, very small context windows resulted in better semantic vectors for the TOEFL test.

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In the era of a global knowledge economy, urban regions that seek to increase their competitive edge, become destinations for talent and investment and provide prosperity and high quality of life to their inhabitants have little chance of achieving these goals without forming effective knowledge-based urban development strategies. The research reported in this paper aims to address the questions of how a knowledge-based urban development performance measurement can be undertaken and the value contribution of such measurement. The paper focuses on the city of Helsinki. This empirical study analytically investigates Helsinki’s performance from the lens of knowledge-based urban development by comparing this urban region with eight international competitors, Boston, San Francisco, Birmingham, Manchester, Melbourne, Sydney, Toronto, and Vancouver. The results of the study not only reveal a clearer understanding of Helsinki’s benchmarked performance and competitive edge considering the regional policy context along with strategic directions in strengthening its international standing and competitiveness but also provide useful insights for other urban regions that aspire to such development.

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1. Biodiversity, water quality and ecosystem processes in streams are known to be influenced by the terrestrial landscape over a range of spatial and temporal scales. Lumped attributes (i.e. per cent land use) are often used to characterise the condition of the catchment; however, they are not spatially explicit and do not account for the disproportionate influence of land located near the stream or connected by overland flow. 2. We compared seven landscape representation metrics to determine whether accounting for the spatial proximity and hydrological effects of land use can be used to account for additional variability in indicators of stream ecosystem health. The landscape metrics included the following: a lumped metric, four inverse-distance-weighted (IDW) metrics based on distance to the stream or survey site and two modified IDW metrics that also accounted for the level of hydrologic activity (HA-IDW). Ecosystem health data were obtained from the Ecological Health Monitoring Programme in Southeast Queensland, Australia and included measures of fish, invertebrates, physicochemistry and nutrients collected during two seasons over 4 years. Linear models were fitted to the stream indicators and landscape metrics, by season, and compared using an information-theoretic approach. 3. Although no single metric was most suitable for modelling all stream indicators, lumped metrics rarely performed as well as other metric types. Metrics based on proximity to the stream (IDW and HA-IDW) were more suitable for modelling fish indicators, while the HA-IDW metric based on proximity to the survey site generally outperformed others for invertebrates, irrespective of season. There was consistent support for metrics based on proximity to the survey site (IDW or HA-IDW) for all physicochemical indicators during the dry season, while a HA-IDW metric based on proximity to the stream was suitable for five of the six physicochemical indicators in the post-wet season. Only one nutrient indicator was tested and results showed that catchment area had a significant effect on the relationship between land use metrics and algal stable isotope ratios in both seasons. 4. Spatially explicit methods of landscape representation can clearly improve the predictive ability of many empirical models currently used to study the relationship between landscape, habitat and stream condition. A comparison of different metrics may provide clues about causal pathways and mechanistic processes behind correlative relationships and could be used to target restoration efforts strategically.

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Several techniques have been proposed in the literature to measure productivity. While allowing for inefficiency of the production unit, we provide a methodological comparison of alternative approaches to measure total factor productivity. This article evaluates the effects of unintended policy outcomes such as government subsidies and foreign trade. Empirically, we analyse the forest productivity of timber in Japan by using panel data on 46 regions. The results suggest substantial variation in productivity between these two techniques although average trends are similar. We find that subsidies impede competition since the government is ready to rescue a loss-making firm with subsidies rather than allow it to close. In contrast, trade is shown to have positive effects on productivity.

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The function of a protein can be partially determined by the information contained in its amino acid sequence. It can be assumed that proteins with similar amino acid sequences normally have closer functions. Hence analysing the similarity of proteins has become one of the most important areas of protein study. In this work, a layered comparison method is used to analyze the similarity of proteins. It is based on the empirical mode decomposition (EMD) method, and protein sequences are characterized by the intrinsic mode functions (IMFs). The similarity of proteins is studied with a new cross-correlation formula. It seems that the EMD method can be used to detect the functional relationship of two proteins. This kind of similarity method is a complement of traditional sequence similarity approaches which focus on the alignment of amino acids

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The problem of collisions between road users and trains at rail level crossings (RLXs) remains resistant to current countermeasures. One factor underpinning these collisions is poor Situation Awareness (SA) on behalf of the road user involved (i.e. not being aware of an approaching train). Although this is a potential threat at any RLX, the factors influencing SA may differ depending on whether the RLX is located in a rural or urban road environment. Despite this, there has been no empirical investigation regarding how road user SA might differ across distinct RLX environments. This knowledge is needed to establish the extent to which a uniform approach to RLX design and safety is acceptable. The aim of this paper is to investigate the differences in driver SA at rural versus urban RLXs. We present analyses of driver SA in both rural and urban RLX environments based on two recent on-road studies undertaken in Victoria, Melbourne. The findings demonstrate that driver SA is markedly different at rural and urban RLXs, and also that poor SA regarding approaching trains may be caused by different factors. The implications for RLX design and safety are discussed.

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The Internet has been shown to positively enhance internationalisation for SMEs, but scant empirical testing limits our understanding of the explicit impact of the Internet on firm internationalisation. This paper highlights key areas where the integration of the Internet can be leveraged through Internet-related capabilities within the internationalisation of the firm. Specifically, this study investigates how Internet marketing capabilities play a role in altering international information availability, international strategic orientation, and international business network relationships. This study provides evidence, indicating that these key relationships may vary between countries. To examine these key relationships this study utilises draws from data small and medium sized enterprises (SMEs) in three export intensive markets; Australia (215 international SMEs), Chile (204 international SMEs) and Taiwan (130 international SMEs); and tests a conceptual model through structural equation modelling. Results from the data show the impact of Internet marketing capabilities in positively impacting traditional internationalisation elements, which varies between countries. That is, our findings highlight the international business network relationships in Australia and Taiwan are directly impacted by Internet marketing capabilities, but not in Chile. We offer some insight into why we see variance across comparative exporting countries in how they leverage new technological capabilities for internationalisation and firm performance.

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In this paper, we use an experimental design to compare the performance of elicitation rules for subjective beliefs. Contrary to previous works in which elicited beliefs are compared to an objective benchmark, we consider a purely subjective belief framework (confidence in one’s own performance in a cognitive task and a perceptual task). The performance of different elicitation rules is assessed according to the accuracy of stated beliefs in predicting success. We measure this accuracy using two main factors: calibration and discrimination. For each of them, we propose two statistical indexes and we compare the rules’ performances for each measurement. The matching probability method provides more accurate beliefs in terms of discrimination, while the quadratic scoring rule reduces overconfidence and the free rule, a simple rule with no incentives, which succeeds in eliciting accurate beliefs. Nevertheless, the matching probability appears to be the best mechanism for eliciting beliefs due to its performances in terms of calibration and discrimination, but also its ability to elicit consistent beliefs across measures and across tasks, as well as its empirical and theoretical properties.

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This study examines how do the processes of politicization differ in the Finnish and the French local contexts, and what kinds of consequences do these processes have on the local civic practices, the definitions and redefinitions of democracy and citizenship, the dynamics of power and resistance, and the ways of solving controversies in the public sphere. By means of comparative anthropology of the state , focusing on how democracy actually is practiced in different contexts, politicizations the processes of opening political arenas and recognizing controversy are analyzed. The focus of the study is on local activists engaged in different struggles on various levels of the local public spheres, and local politicians and civil servants participating in these struggles from their respective positions, in two middle-size European cities, Helsinki and Lyon. The empirical analyses of the book compare different political actors and levels of practicing democracy simultaneously. The study is empirically based on four different bodies of material: Ethnographic notes taken during a fieldwork among the activities of several local activist groups; 47 interviews of local activists and politicians; images representing different levels of public portrayals from activist websites (Helsinki N=274, Lyon N=232) and from city information magazines (Helsinki-info N=208, Lyon Citoyen N= 357); and finally, newspaper articles concerning local conflict issues, and reporting on the encounters between local citizens and representatives of the cities (January-June in 2005; Helsingin Sanomat N=96 and Le Progrès N= 102). The study makes three distinctive contributions to the study of current democratic societies: (1) a conceptual one by bringing politicization at the center of a comparison of political cultures, and by considering in parallel the ethnographic group styles theory by Nina Eliasoph and Paul Lichterman, the theory on counter-democracy by Pierre Rosanvallon and the pragmatist justification theory by Luc Boltanski and Laurent Thévenot; (2) an empirical one through the triangulation of ethnographic, thematic interview, visual, and newspaper data through which the different aspects of democratic practices are examined; and (3) a methodological one by developing new ways of analyzing comparative cases an application of Frame Analysis to visual material and the creation of Public Justification Analysis for analyzing morally loaded claims in newspaper reports thus building bridges between cultural, political, and pragmatic sociology. The results of the study indicate that the cultural tools the Finnish civic actors had at their disposal were prone to hinder more than support politicization, whereas the tools the French actors mainly relied on were frequently apt for making politicization possible. This crystallization is defined and detailed in many ways in the analyses of the book. Its consequences to the understanding and future research on the current developments of democracy are multiple, as politicization, while not assuring good results as such, is central to a functioning and vibrant democracy in which injustices can be fixed and new directions and solutions sought collectively.

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A careful comparison of the distribution in the (R, θ)-plane of all NH ... O hydrogen bonds with that for bonds between neutral NH and neutral C=O groups indicated that the latter has a larger mean R and a wider range of θ and that the distribution was also broader than for the average case. Therefore, the potential function developed earlier for an average NH ... O hydrogen bond was modified to suit the peptide case. A three-parameter expression of the form {Mathematical expression}, with △ = R - Rmin, was found to be satisfactory. By comparing the theoretically expected distribution in R and θ with observed data (although limited), the best values were found to be p1 = 25, p3 = - 2 and q1 = 1 × 10-3, with Rmin = 2·95 Å and Vmin = - 4·5 kcal/mole. The procedure for obtaining a smooth transition from Vhb to the non-bonded potential Vnb for large R and θ is described, along with a flow chart useful for programming the formulae. Calculated values of ΔH, the enthalpy of formation of the hydrogen bond, using this function are in reasonable agreement with observation. When the atoms involved in the hydrogen bond occur in a five-membered ring as in the sequence[Figure not available: see fulltext.] a different formula for the potential function is needed, which is of the form Vhb = Vmin +p1△2 +q1x2 where x = θ - 50° for θ ≥ 50°, with p1 = 15, q1 = 0·002, Rmin = 2· Å and Vmin = - 2·5 kcal/mole. © 1971 Indian Academy of Sciences.