How to measure own-group preference? A novel approach to a sociometric problem

In this article we present a precise definition of the notion "own-group preference" and characterize all functions capable of correctly measuring it. Examples of such functions are provided. The weighted Lorenz curve and the theory developed for it will be our main tools for reaching this goal. We further correct our earlier articles on this subject. In the context of own-language preference, Bookstein and Yitzhaki proposed the logarithm of the odds-ratio as an acceptable measure of own-group preference. We now present a general framework within which the concept of own-group preference, and its opposite, namely own-group aversion, can be precisely pinpointed. This framework is derived form inequality theory and is based on the use of the weighted Lorenz curve. The concept of own-group preference is an interesting notion with applications in different fields such as sociology, political sciences, economics, management science and of course, the information sciences. Some examples are provided. This revised version was published online in June 2006 with corrections to the Cover Date.     

Which battery model to use?

The use of mobile devices like cell phones, navigation systems or laptop computers is limited by the lifetime of the included batteries. This lifetime depends naturally on the rate at which energy is consumed; however, it also depends on the usage pattern of the battery. Continuous drawing of a high current results in an excessive drop of residual capacity. However, during intervals with no or very small currents, batteries do recover to a certain extent. The usage pattern of a device can be well modelled with stochastic workload models. However, one still needs a battery model to describe the effects of the power consumption on the state of the battery. Over the years many different types of battery models have been developed for different application areas. In this study we give a detailed analysis of two well-known analytical models, the kinetic battery model (KiBaM) and the so-called diffusion model. We show that the KiBaM is actually an approximation of the more complex diffusion model; this was not known previously. Furthermore, we tested the suitability of these models for performance evaluation purposes, and found that both models are well suited for doing battery lifetime predictions. However, one should not draw conclusions on what is the best usage pattern based on only a few workload traces.     

Why do people want to use location-based application for emergency situations? The extension of UTAUT perspectives

This study aims to determine the factors that influence user intention to use location-based emergency applications. The Unified Theory of Acceptance and Use of Technology (UTAUT) is used as a fundamental theory by adding other relevant variables: trust, privacy concern, and fear of crime. Data were collected through questionnaires distributed to the users of the X-Igent Panic Button application. A total of 348 data were collected online using random sampling and processed using structural equation modeling. This study concludes that this application adoption's determinant factors are performance expectancy, trust, social influence, fear of crime, and collection as privacy concerns. These factors become significant predictors of behavioral intention by explaining about 60.5% of the total variation. The study also concludes that trust in services or service providers has the most significant positive impact on the behavioral intention to use location-based mobile applications in emergencies.     

To select or to combine? The inventory performance of model and expert forecasts

Demand forecasting is a crucial input of any inventory system. The quality of the forecasts should be evaluated not only in terms of forecast accuracy or bias but also with regards to their inventory implications, which include the impact on the total inventory cost, the achieved service levels and the variance of orders and inventory. Forecast selection and combination are two very widely applied forecasting strategies that have shown repeatedly to increase the forecasting performance. However, the inventory performance of these strategies remains unexplored. We empirically examine the effects of forecast selection and combination on inventory when two sources of forecasts are available. We employ a large data-set that contains demands and (statistical and judgmental) forecasts for multiple pharmaceutical stock keeping units. We show that forecast selection and simple combination increase simultaneously the forecasting and inventory performance.     

Chemical amplification — A novel approach to ultratrace analysis

The lowest concentration that can be estimated with 100% error in chemical analysis by instrumental technique is referred to as detection limit. It is equal to the ratio of twice the background signal to the magnitude of analytical signal corresponding to a concentration of unity. Detection limit (dl) could be improved if the analytical signal alone could be selectively amplified without affecting the background. It is shown that this could be achieved by chemical amplification. Atomic amplification of two or three orders of magnitude could be obtained by combining two chemical amplifications in series. It is demonstrated that by using heteropoly acid formation as the first amplification reaction and determining molybdenum in the heteropoly acid by catalyticdc polarographic wave, a detection limit for the hetero atom of less than a ppb can be obtained. It is pointed out that the approach of selectively amplifying analytical signals by tandem chemical amplification reactions makes it possible to perform ultratrace analysis (ppb level) with classical instrumental analytical techniques which havedl at ppm level.     

The development of ‘green’ airports: Which factors influence willingness to pay for sustainability and intention to act? A structural and mediation model analysis

The study's purpose was to determine which factors influence a consumer's willingness to pay for sustainability and their intention to take action against climate change related to airports. An expanding body of literature relates to assessing whether consumers would be willing to pay for these ‘green’ practices in the aviation industry, such as biofuels or sustainable airport construction/renovations. While previous studies have experimentally examined these scenarios, we are aware of no prior research that has proposed and assessed a structural model related to determining which factors influence consumer's perspectives on ‘green’ airports. A sample of 722 eligible participants from the United States completed the study using Amazon's Mechanical Turk. We examined future time perspective, affect toward climate change, the perceived value of sustainability, and perceptions of climate change on the endogenous variables of willingness to pay for sustainability and intentions to take action against climate change. Six of the seven hypotheses proposed were supported. Affect, perceived value, and perceptions of climate change were all significant and positively related to willingness to pay, which was positively associated with intention to act. Two non-hypothesized paths, between perceived value and future time perspective, were also positively related to intention to act. The model explained 42% of the variance in willingness to pay and 66% in intention to act. These findings offer insights into what factors significantly influence these relationships as they relate to airports. Perceived value and perceptions of climate change had the largest effect sizes in the model and were significantly related to willingness to pay and intentions to act.     

‘Little wake turbulence,huh?’ Applying a contemporary model of learning and memory to the American Airlines Flight AA587 accident

Loss of control has become a leading cause of aviation accidents and human error is often recorded as the cause in favour of other factors. This has the effect of downgrading the significance of corrective actions to address deeper systemic issues, and serves the bad-apple theory of human error. This paper uses a model of learning and memory to expand on the analysis of negative training from the AA587 accident, which documented the actions of the First Officer as the probable cause and training as contributory. Evidence from the investigation and our contemporary understanding of learning and memory is used to explain how the experiences of the First Officer fit the scenario in which the accident occurred, such that it is plausible to extend probable cause beyond his actions. The paper develops a model of causal inference that enables analysts to continue probing causality as part of a systems approach.     

A novel processing scheme for core – shell nano composites using controlled polymer adsorption

 A new processing scheme has been developed for the preparation of core-shell structured composite particles that can be used as building blocks for the fabrication of nanocomposites [1]. The scheme is a two stage coating process utilizing controlled polymer adsorption and bridging in which a layer of nano sized particles is bridged onto submicron sized core particles. The coating process is monitored using electrokinetic techniques as well as SEM. The controlled coating process was used also to prepare multilayer nanocomposites. The application of the coating process to concentrated suspensions (15 volume percent) required in ceramic processing was shown to be feasible. Ceramic compacts were successfully prepared using pressure filtration methods and tested for their green density and flexibility. Received: 18 October 1998/Revised and accepted: 1 December 1998     

The reservoir pressure concept: the 3-element windkessel model revisited? Application to the Asklepios population study

Traditionally the arterial system is either modeled as a lumped-parameter windkessel or a wave system. Recently, a hybrid model has been proposed in which the arterial system is considered to be a reservoir allowing for superimposed wave phenomena. This approach was applied to non-invasively obtained carotid pressure waveforms from 2019 subjects from the Asklepios population to investigate the contribution of reservoir pressure (PP _res,WS) to carotid pulse pressure (PP _car) with age and gender. Additionally, reservoir pressures were compared to the reservoir pressure (PP _res,WK) obtained from a 3-element windkessel model. PP _res,WK and PP _res,WS were determined by applying a 3-element windkessel model and the wave separation model to scaled carotid artery tonometry readings. The evolution of PP _car, PP _res,WK and PP _res,WS was examined for men and women after stratification into age quartiles. PP _car increased with age regardless of sex, but was more pronounced in women, with significant (P < 0.001) age–gender interaction. PP _res increases with age (P < 0.001), regardless of the model used for its determination, but more significantly for women. In men it only increases markedly in the oldest age group. Overall, the reservoir pressure concept showed large similarities to the classical 3-element windkessel model, especially in subjects characterized by a high reflection magnitude and high “windkesselness” of their arterial system. When applied to the Asklepios population, both models show the increase of pulse pressure with age to be largely due to increasing reservoir pressures.     

Can technology lead to a competitive advantage? A case study of Flanders using european patent data

The study tries to analyze regional technological capabilities, linking technological positions to economic strength of the region. To measure this link, we correlate the EPO patent data with trade data to assess the degree to which technological advantages are translated into comparative advantages for the Flemish region in Belgium. The analysis for Flanders provides some interesting insights. Following the skewed distribution of firms, the technological areas in which Flanders is able to build, a strong position are very specific: printing technology, weaving technology, photography and recently also telecommunications. Weak positions are outspoken in car technology. Linking these strengths and weaknesses in technological areas to economic activity revealed an important mismatch between both. Most of the Flemish patents are in sectors without any comparative advantage, while most of the sectors where Flanders does hold a comparative advantage, like chemicals and pharmaceuticals, do not show strong technological advantages in terms of patents. Given the mismatch that was detected between technological positions and economic advantages, it is of crucial importance to better understand the (missing) links between the various actors in the regional innovation system. The analysis points out two important issues. The large and growing number of foreign applications to Belgian/Flemish inventors and the large number of subsidiaries of foreign firms among Belgian/Flemish applications illustrate the pervasiveness of the foreign dimension in the Belgian/Flemish technological landscape. Also very specific to the Belgian/Flemish situation, is the limited importance of universities or research centers in terms of patenting activities.     

The role of cognitive absorption in predicting mobile internet users’ continuance intention: An extension of the expectation-confirmation model

This study uses the expectation-confirmation model (ECM) to investigate how individuals' cognitive absorption (CA) influences their continued use of mobile Internet services. Data were collected from 946 mobile Internet users. Structural equation modelling was employed to analyse the proposed model and examine the relationships between its constructs. Overall, the model accounted for 55% of the variance in mobile Internet users’ continuance intentions—an element substantially impacted by such factors as perceived usefulness, satisfaction, and CA. Of the factors, CA was found to be the most robust predictor of continuance intention. Alongside confirmation, CA also strongly influenced satisfaction. The findings of this study provide mobile network operators with insights into which determinants will inform retention policies and encourage existing users to continue using the service.     

A multi-phase kinetic model to simulate hydration of slag–cement blends

Ground granulated blast furnace slag, which shows cementitious behavior (latent hydraulic activity) and pozzolanic characteristics (reaction with lime), has been widely used as a mineral admixture in normal and high strength concretes. Hydration of slag–blended cement is much more complex than that of ordinary Portland cement because of the mutual interactions between the cement hydration and the slag reaction. This paper presents a kinetic hydration model for cement–slag blends. The proposed model analyzes the slag reaction separate from cement hydration by considering the production of calcium hydroxide in cement hydration and its consumption in slag reactions. The amount of free water and the amount of calcium hydroxide left in the system were adopted as the control indicators for determining the slag reaction. Using the proposed model, the reaction ratio of slag can be evaluated as a function of curing age, considering the influences of the water to binder ratio, the slag replacement ratio and the curing temperature. Furthermore, the amount of chemically-bound water (self-cementing properties), calcium hydroxide (pozzolanic capabilities), and the heat released from hydration are evaluated by determining the contributions from both the cement hydration and the slag reaction. The evaluated results show good accordance with the experimental results.     

A novel biomimetic approach to the design of high-performance ceramic–metal composites

The prospect of extending natural biological design to develop new synthetic ceramic–metal composite materials is examined. Using ice-templating of ceramic suspensions and subsequent metal infiltration, we demonstrate that the concept of ordered hierarchical design can be applied to create fine-scale laminated ceramic–metal (bulk) composites that are inexpensive, lightweight and display exceptional damage-tolerance properties. Specifically, Al₂O₃/Al–Si laminates with ceramic contents up to approximately 40 vol% and with lamellae thicknesses down to 10 µm were processed and characterized. These structures achieve an excellent fracture toughness of 40 MPa√m at a tensile strength of approximately 300 MPa. Salient toughening mechanisms are described together with further toughening strategies.     

The story behind Oncotarget? A bibliometric analysis

Being the most proliferative journal of oncology a cancer research of the past decade, the Open Access journal Oncotarget had reached more than 20,000 publications and a relatively high impact factor score in the past years. In 2018, the journal citation report decided to withdraw the status of an impact factor journal. Since there was a large discussion in the scientific community and specific reasons for the withdrawal were not stated, this bibliometric analysis was performed to assess if Oncotarget exhibits any differences in its bibliometric structure compared to other journals. For this purpose, we used the “New Quality and Quantity Indices in Sciences” platform and analyzed 20,000 Oncotarget articles. Density equalizing mapping technique helps to construct maps of cancer research in Oncotarget and shows that it has led to a unique global landscape which is not asymmetrically dominated by the Western hemisphere but exhibits a publishing architecture with a pronounced emphasis on Chinese articles.