Modelling oil absorption during post-frying cooling - II: solution of the mathematical model, model testing and simulations

The mathematical models that describe the immersion-frying period and the post-frying cooling period of an infinite slab or an infinite cylinder were solved and tested. Results were successfully compared with those found in the literature or obtained experimentally, and were discussed in terms of the hypotheses and simplifications made. The models were used as the basis of a sensitivity analysis. Simulations showed that a decrease in slab thickness and core heat capacity resulted in faster crust development. On the other hand, an increase in oil temperature and boiling heat transfer coefficient between the oil and the surface of the food accelerated crust formation. The model for oil absorption during cooling was analysed using the tested post-frying cooling equation to determine the moment in which a positive pressure driving force, allowing oil suction within the pore, originated. It was found that as crust layer thickness, pore radius and ambient temperature decreased so did the time needed to start the absorption. On the other hand, as the effective convective heat transfer coefficient between the air and the surface of the slab increased the required cooling time decreased. In addition, it was found that the time needed to allow oil absorption during cooling was extremely sensitive to pore radius, indicating the importance of an accurate pore size determination in future studies.

Testing Accrual-Based Model for Detecting Earnings Management: Comparison of Finland and France

The aim of this study is to test the accrual-based model suggested by Dechow et al. (1995) in order to detect and compare earnings management practices in Finnish and French companies. Also the impact of financial crisis of 2008 on earnings management behavior in these countries is tested by dividing the whole time period of 2003-2012 into two sub-periods: pre-crisis (2003-2008) and post-crisis (2009-2012). Results support the idea that companies in both countries have significant earnings management practices. During the post-crisis period companies in Finland show income inflating practices, while in France the opposite tendency is noticed (income deflating) during the same period. Results of the assumption that managers in highly concentrated companies are engaged in income enhancing practices vary in two countries. While in Finland managers are trying to show better performance for bonuses or other contractual compensation motivations, in France they avoid paying dividends or high taxes.

Improving wheat simulation capabilities in Australia from a cropping systems perspective - II. Testing simulation capabilities of wheat growth

To simulate cropping systems, crop models must not only give reliable predictions of yield across a wide range of environmental conditions, they must also quantify water and nutrient use well, so that the status of the soil at maturity is a good representation of the starting conditions for the next cropping sequence. To assess the suitability for this task a range of crop models, currently used in Australia, were tested. The models differed in their design objectives, complexity and structure and were (i) tested on diverse, independent data sets from a wide range of environments and (ii) model components were further evaluated with one detailed data set from a semi-arid environment. All models were coded into the cropping systems shell APSIM, which provides a common soil water and nitrogen balance. Crop development was input, thus differences between simulations were caused entirely by difference in simulating crop growth. Under nitrogen non-limiting conditions between 73 and 85% of the observed kernel yield variation across environments was explained by the models. This ranged from 51 to 77% under varying nitrogen supply. Water and nitrogen effects on leaf area index were predicted poorly by all models resulting in erroneous predictions of dry matter accumulation and water use. When measured light interception was used as input, most models improved in their prediction of dry matter and yield. This test highlighted a range of compensating errors in all modelling approaches. Time course and final amount of water extraction was simulated well by two models, while others left up to 25% of potentially available soil water in the profile. Kernel nitrogen percentage was predicted poorly by all models due to its sensitivity to small dry matter changes. Yield and dry matter could be estimated adequately for a range of environmental conditions using the general concepts of radiation use efficiency and transpiration efficiency. However, leaf area and kernel nitrogen dynamics need to be improved to achieve better estimates of water and nitrogen use if such models are to be use to evaluate cropping systems. (C) 1998 Elsevier Science B.V.

A landscape-scale test of the predictive ability of a spatially explicit model for population viability analysis

1. Although population viability analysis (PVA) is widely employed, forecasts from PVA models are rarely tested. This study in a fragmented forest in southern Australia contrasted field data on patch occupancy and abundance for the arboreal marsupial greater glider Petauroides volans with predictions from a generic spatially explicit PVA model. This work represents one of the first landscape-scale tests of its type. 2. Initially we contrasted field data from a set of eucalypt forest patches totalling 437 ha with a naive null model in which forecasts of patch occupancy were made, assuming no fragmentation effects and based simply on remnant area and measured densities derived from nearby unfragmented forest. The naive null model predicted an average total of approximately 170 greater gliders, considerably greater than the true count (n = 81). 3. Congruence was examined between field data and predictions from PVA under several metapopulation modelling scenarios. The metapopulation models performed better than the naive null model. Logistic regression showed highly significant positive relationships between predicted and actual patch occupancy for the four scenarios (P = 0.001-0.006). When the model-derived probability of patch occupancy was high (0.50-0.75, 0.75-1.00), there was greater congruence between actual patch occupancy and the predicted probability of occupancy. 4. For many patches, probability distribution functions indicated that model predictions for animal abundance in a given patch were not outside those expected by chance. However, for some patches the model either substantially over-predicted or under-predicted actual abundance. Some important processes, such as inter-patch dispersal, that influence the distribution and abundance of the greater glider may not have been adequately modelled. 5. Additional landscape-scale tests of PVA models, on a wider range of species, are required to assess further predictions made using these tools. This will help determine those taxa for which predictions are and are not accurate and give insights for improving models for applied conservation management.

An overview of APSIM, a model designed for farming systems simulation

The Agricultural Production Systems Simulator (APSIM) is a modular modelling framework that has been developed by the Agricultural Production Systems Research Unit in Australia. APSIM was developed to simulate biophysical process in farming systems, in particular where there is interest in the economic and ecological outcomes of management practice in the face of climatic risk. The paper outlines APSIM's structure and provides details of the concepts behind the different plant, soil and management modules. These modules include a diverse range of crops, pastures and trees, soil processes including water balance, N and P transformations, soil pH, erosion and a full range of management controls. Reports of APSIM testing in a diverse range of systems and environments are summarised. An example of model performance in a long-term cropping systems trial is provided. APSIM has been used in a broad range of applications, including support for on-farm decision making, farming systems design for production or resource management objectives, assessment of the value of seasonal climate forecasting, analysis of supply chain issues in agribusiness activities, development of waste management guidelines, risk assessment for government policy making and as a guide to research and education activity. An extensive citation list for these model testing and application studies is provided. Crown Copyright (C) 2002 Published by Elsevier Science B.V. All rights reserved.

A Generalized Model Study of Scour Around Bridge Piers and Abutments, HR-24, 1953

Four classes of variables are apparent in the problem of scour around bridge piers and abutments--geometry of piers and abutments, stream-flow characteristics, sediment characteristics, and geometry of site. The laboratory investigation, from its inception, has been divided into four phases based on these classes. In each phase the variables in three of the classes are held constant and those in the pertinent class are varied. To date, the first three phases have been studied. Typical scour bole patterns related to the geometry of the pier or abutment have been found. For equilibrium conditions of scour with uniform sand, the velocity of flow and the sand size do not appear to have any measurable effects on the depth of scour. This result is especially encouraging in the search for correlation between model and prototype since it would indicate that, primarily, only the depth of flow might be involved in the scale effect. The technique of model testing has been simplified, therefore, because rate of sediment transportation does not need to be scaled. Prior to the establishment of equilibrium conditions, however, depths of scour in excess of those for equilibrium conditions have been found. A concept of active scour as an imbalance between sediment transport capacity and rate of sediment supply has been used to explain the laboratory observations.

Using modular neural networks to model self-consciousness and self-representation for artificial entities

Self-consciousness implies not only self or group recognition, but also real knowledge of one’s own identity. Self-consciousness is only possible if an individual is intelligent enough to formulate an abstract self-representation. Moreover, it necessarily entails the capability of referencing and using this elf-representation in connection with other cognitive features, such as inference, and the anticipation of the consequences of both one’s own and other individuals’ acts. In this paper, a cognitive architecture for self-consciousness is proposed. This cognitive architecture includes several modules: abstraction, self-representation, other individuals'representation, decision and action modules. It includes a learning process of self-representation by direct (self-experience based) and observational learning (based on the observation of other individuals). For model implementation a new approach is taken using Modular Artificial Neural Networks (MANN). For model testing, a virtual environment has been implemented. This virtual environment can be described as a holonic system or holarchy, meaning that it is composed of autonomous entities that behave both as a whole and as part of a greater whole. The system is composed of a certain number of holons interacting. These holons are equipped with cognitive features, such as sensory perception, and a simplified model of personality and self-representation. We explain holons’ cognitive architecture that enables dynamic self-representation. We analyse the effect of holon interaction, focusing on the evolution of the holon’s abstract self-representation. Finally, the results are explained and analysed and conclusions drawn.

The Role of Attachment in a Social Cognitive Model of Social Domain Satisfaction in College Students

The study examined a modified social cognitive model of domain satisfaction (Lent, 2004). In addition to social cognitive variables and trait positive affect, the model included two aspects of adult attachment, attachment anxiety and avoidance. The study extended recent research on well-being and satisfaction in academic, work, and social domains. The adjusted model was tested in a sample of 454 college students, in order to determine the role of adult attachment variables in explaining social satisfaction, above and beyond the direct and indirect effects of trait positive affect. Confirmatory factor analysis found support for 8 correlated factors in the modified model: social domain satisfaction, positive affect, attachment avoidance, attachment anxiety, social support, social self-efficacy, social outcome expectations, and social goal progress. Three alternative structural models were tested to account for the ways in which attachment anxiety and attachment avoidance might relate to social satisfaction. Results of model testing provided support for a model in which attachment avoidance produced only an indirect path to social satisfaction via self-efficacy and social support. Positive affect, avoidance, social support, social self-efficacy, and goal progress each produced significant direct or indirect paths to social domain satisfaction, though attachment anxiety and social outcome expectations did not contribute to the predictive model. Implications of the findings regarding the modified social cognitive model of social domain satisfaction were discussed.

Swapping space for time and unfair tests of ecological models

Testing ecological models for management is an increasingly important part of the maturation of ecology as an applied science. Consequently, we need to work at applying fair tests of models with adequate data. We demonstrate that a recent test of a discrete time, stochastic model was biased towards falsifying the predictions. If the model was a perfect description of reality, the test falsified the predictions 84% of the time. We introduce an alternative testing procedure for stochastic models, and show that it falsifies the predictions only 5% of the time when the model is a perfect description of reality. The example is used as a point of departure to discuss some of the philosophical aspects of model testing.

Use of niche models in invasive species risk assessments.

Risk maps summarizing landscape suitability of novel areas for invading species can be valuable tools for preventing species' invasions or controlling their spread, but methods employed for development of such maps remain variable and unstandardized. We discuss several considerations in development of such models, including types of distributional information that should be used, the nature of explanatory variables that should be incorporated, and caveats regarding model testing and evaluation. We highlight that, in the case of invasive species, such distributional predictions should aim to derive the best hypothesis of the potential distribution of the species by using (1) all distributional information available, including information from both the native range and other invaded regions; (2) predictors linked as directly as is feasible to the physiological requirements of the species; and (3) modelling procedures that carefully avoid overfitting to the training data. Finally, model testing and evaluation should focus on well-predicted presences, and less on efficient prediction of absences; a k-fold regional cross-validation test is discussed.

On the Adoption of Partial Least Squares in Psychological Research: Caveat Emptor

The partial least squares technique (PLS) has been touted as a viable alternative to latent variable structural equation modeling (SEM) for evaluating theoretical models in the differential psychology domain. We bring some balance to the discussion by reviewing the broader methodological literature to highlight: (1) the misleading characterization of PLS as an SEM method; (2) limitations of PLS for global model testing; (3) problems in testing the significance of path coefficients; (4) extremely high false positive rates when using empirical confidence intervals in conjunction with a new "sign change correction" for path coefficients; (5) misconceptions surrounding the supposedly superior ability of PLS to handle small sample sizes and non-normality; and (6) conceptual and statistical problems with formative measurement and the application of PLS to such models. Additionally, we also reanalyze the dataset provided by Willaby et al. (2015; doi:10.1016/j.paid.2014.09.008) to highlight the limitations of PLS. Our broader review and analysis of the available evidence makes it clear that PLS is not useful for statistical estimation and testing.

White mold detection in common beans through leaf reflectance spectroscopy

ABSTRACT This study aimed to identify wavelengths based on leaf reflectance (400-1050 nm) to estimate white mold severity in common beans at different seasons. Two experiments were carried out, one during fall and another in winter. Partial Least Squares (PLS) regression was used to establish a set of wavelengths that better estimates the disease severity at a specific date. Therefore, observations were previously divided in two sub-groups. The first one (calibration) was used for model building and the second subgroup for model testing. Error measurements and correlation between measured and predicted values of disease severity index were employed to provide the best wavelengths in both seasons. The average indexes of each experiment were of 5.8% and 7.4%, which is considered low. Spectral bands ranged between blue and green, green and red, and red and infrared, being most sensitive for disease estimation. Beyond the transition ranges, other spectral regions also presented wavelengths with potential to determine the disease severity, such as red, green, and near infrared.

Teollisten palveluiden kehittäminen asiakaslähtöisesti

Teollisuuden palvelut tuottavat tulevaisuudessa yhä suuremman osan yritysten liikevaihdosta ja tämän vuoksi niiden systemaattinen kehittäminen yrityksessä on erityisen tärkeää. Tutkimuksen tavoitteena on luoda teorian pohjalta malli, jonka avulla mekatroniikkaklusterin yritykset voivat analysoida tarjottavia palveluitaan asiakkaan näkökulmasta. Tutkimuksessa pyritään myös selvittämään empiirisesti mallin soveltuvuus palvelutarjonnan kehittämiseen tutkimuksessa mukana oleville erikokoisille yrityksille. Tutkimuksen teoreettisessa osassa luodaan katsaus yrityksen kasvustrategioihin. Palveluiden innovaatio- sekä kehitysprosessit käydään lyhyesti läpi, sekä esitetään lähtökohtia, miten yritykset voivat siirtyä tuotetarjoajasta palveluntarjoajaksi. Teoriaosassa käydään läpi QFD -malli, jota voidaan käyttää hyödyksi kun analysoidaan asiakkaan palvelutarpeita ja priorisoidaan yrityksen resursseja. QFD -mallin lisäksi esitellään myös muita laatutyökaluja sekä asiakkaan tarpeiden selvitysmenetelmiä, joita yritys voi käyttää hyödykseen QFD -mallin kanssa. Synteesiosassa esitellään ensin MS Excel -pohjainen QFD -malli. Mallin käyttö-kokeilu toteutetaan työpaja tyylisessä kokouksessa, ja tutkimustulokset kerätään havainnoimalla, teemahaastattelulla sekä kyselyn avulla.

Rakennuskonepalveluita tuottavan pk-yrityksen investointi- ja kustannusmalli

Tämän tutkimuksen päätavoitteena oli luoda yleisellä tasolla kustannusmalli maarakennuskonepalveluita tuottavien pk-yritysten käyttöön ja käytännön päätöstilanteiden avuksi osana päätöksenteko organisaation ja myyntityötä tekevän portaan kustannustarkkailuun. Mallin luomisen tarkoituksena oli että mallia voidaan helposti muokata erilaisten myyntitilanteiden kannattavuuksien tarkasteluun ja sitä kautta malli luo käyttäjilleen etulyöntiaseman luodessa pitkiä palvelusopimuksia ja erilaisten projektityömaiden myyntisopimuksia simuloimalla kaluston siirtokustannuksia olemassa olevien tiedettyjen kustannustekijöiden toimesta. Teollisuudessa ja palvelujentarjoajapuolella on vastaavia malleja esitetty, mutta erityisesti maarakennuspuolen ja konevuokrauksen kustannuslaskentamalleja ei julkisesta ole juurikaan saatavilla. Työn kustannusmallin muutoksia simuloitiin ja testattiin luomalla erilaisia kysyntäskenaarioita joista yksi esitellään tarkemmin työn testausosiossa. mallilla on helppo kasata kustannusdataa erilaisina yhtälöinä miten uudet työmaat ovat kannattavampia luomalla kokonaisvaltaisesti paljon lisää uusia työkohteita. Kustannusmallin rakentamiselle oli kysyntää ja tärkeänä tietona pidettiin kokonaisvaltaista muutosta ja tietoa millä tehollisilla tunneilla vastaavat hankinnat olisivat kannattavia. Työn teoriaosa pohjautuu pääasiassa hinnoittelun, kannattavuuden ja investointilaskelmien teoriaan, artikkeleihin ja tutkimuksiin sekä kirjoihin. Työn empiirinen osa perustuu arvioihin tämän hetken hintatasoista sekä arvioihin kustannusten kertymisestä maarakennuspalveluita tuottavissa pk-yrityksissä joissa organisaatiokaavio on matala ja toiminta tehokasta. Keskeisimmät tulokset liittyvät siihen miten kustannuksia tulee huomioida erilaisille asiakkaille ja millainen kustannusmalli on käyttökelpoinen eri tilanteissa.

Étude multicentrique des facteurs influençant l’adoption d’un dossier clinique informatisé hospitalier par des infirmières

À l’instar de plusieurs systèmes de santé, les centres hospitaliers québécois ont amorcé l’informatisation du dossier patient sous forme papier pour la transition vers un dossier clinique informatisé (DCI). Ce changement complexe s’est parfois traduit par des répercussions sur les pratiques de soins, la sécurité et la qualité des soins offerts. L’adoption de la part des utilisateurs de technologies de l’information (TI) est considérée comme un facteur critique de succès pour la réalisation de bénéfices suite au passage à un DCI. Cette étude transversale multicentrique avait pour objectifs d’examiner des facteurs explicatifs de l’adoption, de l’utilisation réelle d’un DCI, de la satisfaction des infirmières et de comparer les résultats au regard du sexe, de l’âge, de l’expérience des infirmières et des stades de déploiement du DCI. Un modèle théorique s’appuyant sur la Théorie unifiée de l’adoption et de l’utilisation de la technologie a été développé et testé auprès d’un échantillon comptant 616 infirmières utilisant un DCI hospitalier dans quatre milieux de soins différents. Plus particulièrement, l’étude a testé 20 hypothèses de recherche s’intéressant aux relations entre huit construits tels la compatibilité du DCI, le sentiment d’auto-efficacité des infirmières, les attentes liées à la performance, celles qui sont liées aux efforts à déployer pour adopter le DCI, l'influence sociale dans l’environnement de travail, les conditions facilitatrices mises de l’avant pour soutenir le changement et ce, relativement à l’utilisation réelle du DCI et la satisfaction des infirmières. Au terme des analyses de modélisation par équations structurelles, 13 hypothèses de recherche ont été confirmées. Les résultats tendent à démontrer qu’un DCI répondant aux attentes des infirmières quant à l’amélioration de leur performance et des efforts à déployer, la présence de conditions facilitatrices dans l’environnement de travail et un DCI compatible avec leur style de travail, leurs pratiques courantes et leurs valeurs sont les facteurs les plus déterminants pour influencer positivement l’utilisation du DCI et leur satisfaction. Les facteurs modélisés ont permis d’expliquer 50,2 % de la variance des attentes liées à la performance, 52,9 % des attentes liées aux efforts, 33,6 % de l’utilisation réelle du DCI et 54,9 % de la satisfaction des infirmières. La forte concordance du modèle testé avec les données de l’échantillon a notamment mis en lumière l’influence des attentes liées à la performance sur l’utilisation réelle du DCI (r = 0,55 p = 0,006) et sur la satisfaction des infirmières (r = 0,27 p = 0,010), des conditions facilitatrices sur les attentes liées aux efforts (r = 0,45 p = 0,009), de la compatibilité du DCI sur les attentes liées à la performance (r = 0,39 p = 0,002) et sur celles qui sont liées aux efforts (r = 0,28 p = 0,009). Les nombreuses hypothèses retenues ont permis de dégager l’importance des effets de médiation captés par le construit des attentes liées à la performance et celui des attentes liées aux efforts requis pour utiliser le DCI. Les comparaisons fondées sur l’âge, l’expérience et le sexe des répondants n’ont décelé aucune différence statistiquement significative quant à l’adoption, l’utilisation réelle du DCI et la satisfaction des infirmières. Par contre, celles qui sont fondées sur les quatre stades de déploiement du DCI ont révélé des différences significatives quant aux relations modélisées. Les résultats indiquent que plus le stade de déploiement du DCI progresse, plus on observe une intensification de certaines relations clés du modèle et une plus forte explication de la variance de la satisfaction des infirmières qui utilisent le DCI. De plus, certains résultats de l’étude divergent des données empiriques produites dans une perspective prédictive de l’adoption des TI. La présente étude tend à démontrer l’applicabilité des modèles et des théories de l’adoption des TI auprès d’infirmières œuvrant en centre hospitalier. Les résultats indiquent qu’un DCI répondant aux attentes liées à la performance des infirmières est le facteur le plus déterminant pour influencer positivement l’utilisation réelle du DCI et leur satisfaction. Pour la gestion du changement, l’étude a relevé des facteurs explicatifs de l’adoption et de l’utilisation d’un DCI. La modélisation a aussi mis en lumière les interrelations qui évoluent en fonction de stades de déploiement différents d’un DCI. Ces résultats pourront orienter les décideurs et les agents de changement quant aux mesures à déployer pour optimiser les bénéfices d’une infostructure entièrement électronique dans les systèmes de santé.