Wright's Model Research Articles

Correlating multicomponent surface tension data with Padé approximants. Part I. Surface tension

Eberhardt (1966), Connors and Wright (1989), Piñeiro et al. (2001), Das and Bhattacharyya (2003) and Belda (2009) all proposed successful mixture models for correlating the surface tension data for binary liquid mixtures. Rational extensions of these semi-theoretical and empirical models are derived in order to cater for multicomponent mixtures. It is shown that a canonical Padé approximant emanates from the Piñeiro et al. (2001) and Das et al. (2003) proposals:σ=∑iβiixiσi∑jκijxj/∑i∑jβijxixjWhere the σi’s are the surface tensions of the pure components as a function of temperature. The βij and κij are adjustable model constants (with κii = 1) and they carry some physical meaning. The other models are special cases that are obtained by the application of different combining rules. For example, when the Extended Langmuir model developed by Piñeiro et al. (2001) holds, one obtains βij=βiiβjj; on the other hand, it reduces to the Connors and Wright (1989) model if βij=βii+βjj/2. The theories underpinning these models, suggest that the parameters βij and κij might be temperature dependent. However, Shardt and Elliott (2017) found that, for binary systems they can be assumed constant, i.e. that the temperature dependence is carried solely by the pure component surface tensions. This premise was confirmed for the seven ternary systems which were used to validate the proposed multicomponent canonical Padé approximant.

Prediction of learning curves of wired and wireless intraoral scanners

This clinical study aimed to predict the learning curve of wireless and wired intraoral scanners (IOSs) and to compare the reduction patterns of working time. Overall, 14 participants were enrolled in the study. The intraoral scanning procedure was repeated four times, each using wireless and wired IOSs (i700; MEDIT). The work time from the first to the 600th iterations was predicted using the Wright model. Regarding statistical analysis, the Mann–Whitney U-test was performed for comparison between wireless and wired IOSs and between groups with and without an IOS usage experience, and the Friedman test was performed to evaluate the time reduction (α = 0.05). There was a significant difference between wireless and wired IOSs in the first (P = 0.008) and the third (P = 0.035) iterations. Moreover, the time for 600 iterations was statistically significantly different between wireless and wired IOSs (P < 0.05); however, there was no significant difference after the sixth iteration (e.g., seventh iteration: P = 0.062). In wireless IOS, no significant difference was found between participants with and without an IOS usage experience after the 34th iteration (P = 0.053). The difference in the learning effect between wireless and wired IOSs can be overcome by initial learning; however, an IOS usage experience can affect the learning time of wireless IOSs.

Assessment of the Construction Project Costs by Using the Learning Curve

The project feasibility study, which is the scientific technique, a thorough technical and economic analysis, and a demonstration of the projects construction before the project decision are the most crucial components of the project's preparatory work. This paper uses the one-factor learning curve to analyze the project cost and then obtains the feasibility study results for the project. The Wright models are the foundation of the tool developed. The model was chosen due to its applicability to the construction sector and its effectiveness in terms of fitness (ability to fit historical data) and predictability in the past (ability to estimate future data).

The components of teachers' religious literacy: a systematic review based on Wright's model

The components of teachers' religious literacy: a systematic review based on Wright's model

Can Simulation Scenarios Be Designed to Assess Ongoing Nursing Competence?

Learner-centered verification methods are at the core of Donna Wright's model for competency assessment. Using Wright's framework, an academic medical center studied the use of simulation as a verification method for their annual ongoing nursing competency assessment. Of the 10 pilot participants, 60% used simulation as a verification method to successfully show competence. Assuming adequate professional development practitioner and facility resources, simulation can be used as an option for ongoing competency assessment.

Accuracy of the Shardt–Elliott–Connors–Wright equation for predicting the surface tension of metal alloys

Surface tension influences the processing of molten metals including welding, soldering, refining, and casting, but it is challenging to measure at high temperatures, and thus it is an important property to predict. In particular, the surface tension of metal alloys is crucial to predict as a function of alloy composition and temperature. Previously, we developed the Shardt–Elliott–Connors–Wright (SECW) model that has the advantage of being able to predict the surface tension of mixtures as a function of composition and temperature using as inputs only the temperature dependence of pure components and the composition dependence at a single reference temperature. This model has been shown to be accurate for a broad range of non-metal mixtures. In this work, we extend the applicability of our model to six metal alloy systems, resulting in an absolute average percent deviation from experimental measurements of 1.9% over all studied compositions and temperatures ranging between 513 K and 1503 K (419 experimental data points).

Stationary distribution and ergodicity of stochastic Wright's mutualism model with regime switching

We formulate a stochastic Wright's mutualism model with regime switching in this paper. Under some conditions, we testify that the model admits a unique stationary distribution that is ergodic, and the transition probability of the solution of the model exponentially converges to the stationary distribution. Some recent results are extended and improved greatly. An example and several simulations are also provided to illustrate the theoretical findings.

Inferred Measurements of the Zodiacal Light Absolute Intensity through Fraunhofer Absorption Line Spectroscopy with CIBER

Abstract Scattered sunlight from the interplanetary dust (IPD) cloud in our solar system presents a serious foreground challenge for spectrophotometric measurements of the extragalactic background light (EBL). In this work, we report on inferred measurements of the absolute intensity of the zodiacal light (ZL) using the novel technique of Fraunhofer line spectroscopy on the deepest 8542 Å line of the near-infrared Ca ii absorption triplet. The measurements are performed with the narrow band spectrometer (NBS) on board the Cosmic Infrared Background Experiment sounding rocket instrument. We use the NBS data to test the accuracy of two ZL models widely cited in the literature, the Kelsall and Wright models, which have been used in foreground removal analyses that produce high and low EBL results respectively. We find a mean reduced χ 2 = 3.5 for the Kelsall model and χ 2 = 2.0 for the Wright model. The best description of our data is provided by a simple modification to the Kelsall model, which includes a free ZL offset parameter. This adjusted model describes the data with a reduced χ 2 = 1.5 and yields an inferred offset amplitude of 46 ± 19 nW m−2 sr−1 extrapolated to 12500 Å. These measurements elude to the potential existence of a dust cloud component in the inner solar system whose intensity does not strongly modulate with the Earth’s motion around the Sun.

Innovative Utilization of Wright's Model for Competency Validation.

Wright's competency assessment model is well known, yet implementation has been largely challenging. Some organizations have attempted enterprise-wide implementation. This article summarizes how Wright's model was used from a specific topic perspective. Centralized nursing professional development practitioners created flexible competency validation guidelines and supplemental tools (literature review, exemplar, and peer review) for use by sedation nurses regardless of experience or practice setting. Post-implementation data show 62% adoption of new validation methods after 1 year.

Class differences and the Commercial Revolution: An equilibrium selection story

The reopening of the Mediterranean routes in the tenth century sparked, in some regions of Europe, a long period of economic boom. It also triggered a social change whereby some members of the nobility, despite their social status, turned to commerce. I explain these events through the lens a Kiyotaki and Wright (1989) model, extended to a two-country world. The response of the elite to a communication shock causes the economy to transit from a low-to a high-production equilibrium, if pre-existing class differences are not too large. Quantitative experiments illustrate the view of economic historians that medieval expansion ensued in regions where the elite enjoyed relatively modest privileges and was slow in places, most notably France, where the elite's preoccupation for preserving the social-status was strong.

Theoretical Issues and Conceptual Framework for Physical Facilities Design in Hospital Buildings

This study reviewed the theoretical issues relating to morphological and psychological design issues in hospital building design evaluation. The study of morphological configurations design issues, concentrates on the elements of building, shape/form, the structure of the environment, the structural efficiency and the architectural appearance of the hospital building forms. The psychological design issues focused on the essential issues relating to Proximity, Privacy and Wayfindings. Through the literature review of previous models such as, Khan (2012) Operational Efficiency Model, Haron, Hamid and Talib Usability Framework, (2012), Zhao, Mourshed &amp; Wright (2009) Model, Alalouch, Aspinall &amp; Smith Model (2016) and Hill &amp; Kitchen (2009). A conceptual framework for physical facilities design evaluation and satisfaction in hospital buildings was developed. The study, however, provides useful information for the development of a design framework that can inform policy on hospital buildings.

Optimal intervention in a random‐matching model of money

AbstractWe numerically find optimal transfer scheme in the Shi–Trejos–Wright model with extended upper bounds on money holdings. The choice of upper bound matters for the optimal policy as some potentially beneficial transfer schemes cannot be studied under small upper bounds. Money creation (and accompanying inflation) becomes optimal in more examples when the upper bound on money holdings is larger, and the type of optimal transfer depends on the parameters in utility function. This result is in line with the conjecture of Wallace, which says that there generically exists an inflation‐financed transfer scheme that improves welfare over no intervention in pure‐currency economies.

On the Extension of the Kiyotaki and Wright model to Transformable Goods

In this paper we extend the classical Kiyotaki and Wright (KW) model and consider a transformable good. Such an extension enables us to adapt the model to the specific conditions of the wine market. The most important change, with respect to the original model, is that one type of good (young wine, in our model) can improve its quality and thereby transform to another type of good (old wine). However, there is a certain probability that such transformation may not be successful and the good under consideration may simply spoil. We adapt the main KW theoretical features to the study of speculative strategies in a stylized wine market. This study can be generalized to other commodity markets in which goods are unstable and present intrinsic properties such as quality increase or decrease across time. These markets are also typically characterized by roles or types of agents, such as producers, merchants and consumers, whose interests lack double coincidence when they meet. We define a general model and then use simulation methods to systematically study under which conditions speculative strategies are possible in this setting and which is the most efficient distribution of types of agents under speculative equilibria. The theoretical results are also provided for the model, with equal numbers of agents of different types, similarly to the Kiyotaki and Wright original paper.

Time Series Analysis in Forecasting Mental Addition and Summation Performance.

An ideal performance evaluation metric would be predictive, objective, easy to administer, estimate the variance in performance, and provide a confidence interval for the level of uncertainty. Time series forecasting may provide objective metrics for predictive performance in mental arithmetic. Addition and summation (addition combined with subtraction) using the Japanese Soroban computation system was undertaken over 60 days. The median calculation time in seconds for adding 10 sequential six digit numbers [CTAdd) was 63 s (interquartile range (IQR) = 12, range 48–127 s], while that for summation (CTSum) was 70 s (IQR = 14, range 53–108 s), and the difference between these times was statistically significant p < 0.0001. Using the mean absolute percentage error (MAPE) to measure forecast accuracy, the autoregressive integrated moving average (ARIMA) model predicted a further reduction in both CTAdd to a mean of 51.51 ± 13.21 s (AIC = 5403.13) with an error of 6.32%, and CTSum to a mean of 54.57 ± 15.37 s (AIC = 3852.61) with an error of 8.02% over an additional 100 forecasted trials. When the testing was repeated, the actual mean performance differed by 1.35 and 4.41 s for each of the tasks, respectively, from the ARIMA point forecast value. There was no difference between the ARIMA model and actual performance values (p-value CTAdd = 1.0, CTSum=0.054). This is in contrast to both Wright's model and linear regression (p-value < 0.0001). By accounting for both variability in performance over time and task difficulty, forecasting mental arithmetic performance may be possible using an ARIMA model, with an accuracy exceeding that of both Wright's model and univariate linear regression.

The assessment of the genetic structure of bush snail (Fruticicola fruticum) populations based on the nonspecific esterases loci

Using the polymorphic esterases loci, the genetic structure of the gastropod mollusk Fruticicola (Bradybaena) fruticum Мll., most of which lives in the south of the Central Russian Upland, was studied. For comparison, the samples were taken from the Romania, the North Caucasus, the Ural and the Vyatka regions. A total of the 1668 individuals were investigated. Of the 28 studied populations in 11 (39.3%), there was significant shortage of the heterozygotes. The level of the expected heterozygosity fluctuated in the range He = 0.1160.454. Using the non-parametric statistics (Chao1-bc method and 1st order jackknife method), the populations with potentially high and low diversity of the multilocus genotypes were identified. The indicators of the genetic disunity between populations averaged st = 0.276, Fst = 0.292. The principal component analysis and the Mantel correlation criterion Rм = 0.007 showed the absence of a reliable relationship between the geographical and genetic distance between populations, which indicates a violation of the isolation model by distance and confirms the thesis put forward by us that the urbanized forest-steppe landscape disrupts the natural migration processes, leads to the strong isolation and the genetic drift in the snail populations. At the same time, the phenomenon of increasing the degree of division of the populations against the background of reduced the allelic diversity, noted by us in many groups of bush snails, can be regarded as a shift in genetic equilibrium towards an increase in the interpopupulation diversity (according to the Wright model). The revealed absence of the effect of isolation by distance can be a consequence of the action of the stabilizing natural selection. The assumption of the dependence of the esterase alleles frequencies in the bush snail populations on the genetic (biochemical) characteristics of the food objects was proposed. The effective size, calculated using the Slatkin formula turned out to be comparable with the background, adventive and relict species of the terrestrial mollusks living in the study area (Ne = 2.27.6).

Prediction of learning curves of 2 dental CAD software programs, part 2: Differences in learning effects by type of dental personnel

Statement of problemDental computer-aided design (CAD) software programs are essential elements of the digital workflow. Therefore, it is necessary to study the learning effect of dental CAD software programs for efficient use. PurposeThe purpose of this in vitro study was to predict the learning curve of dental CAD software programs according to dental personnel by using the Wright model and to investigate the tendency of dental personnel to reduce working time according to repeated learning. Material and methodsA total of 36 participants were recruited, including an equal number of dentists, dental technicians, and dental students (12 each). A custom abutment design was evaluated by using exocad CAD and Deltanine CAD software programs. The design was carried out in the following order: 4 steps repeated 3 times each. This study applied the formula of the Wright model to predict 500 repetitive times. In the statistical analysis, 3-repetition and 500-repetition times were analyzed with the Kruskal-Wallis H test and Friedman test (α=.05), and a post hoc comparison was performed by using the Mann-Whitney U-test and Bonferroni correction method (α=.017). ResultsThree repetitions resulted in shorter working time in the dental technician group. The 3-repetition time decreased statistically for all dental personnel (P<.001). The time for 500 repetitions showed a statistically significant difference according to the type of dental personnel (P=.036), but no significant difference was found after the fourth iteration (fifth iteration: P=.076). Furthermore, the estimated time of 500 iterations decreased statistically significantly from the first to the 500th iteration (P<.001). ConclusionsAll dental personnel showed learning effects of dental CAD software programs. Although the dental technician group initially showed less working time, after initial learning, the same learning effect appeared, regardless of the type of dental personnel.

Banking crises and liquidity in a monetary economy

This study investigates banks’ liquidity provision using the Lagos and Wright model of monetary exchange. With aggregate uncertainty, we show that banks sometimes exhaust their cash reserves and fail to satisfy their depositors’ needs for consumption smoothing. We also show that banking crises can be eliminated by a rate-of-return-equalizing policy under perfect risk sharing, but the first-best outcome can be only achieved with the Friedman rule. These results cannot be obtained with other monetary models (e.g., overlapping generations models). We also derive a rich array of non-trivial effects of inflation on equilibrium deposits, the probability of banking crises, and banks’ portfolios.

Nonlinear phenotypic variation uncovers the emergence of heterosis in Arabidopsis thaliana.

Heterosis describes the phenotypic superiority of hybrids over their parents in traits related to agronomic performance and fitness. Understanding and predicting nonadditive inheritance such as heterosis is crucial for evolutionary biology as well as for plant and animal breeding. However, the physiological bases of heterosis remain debated. Moreover, empirical data in various species have shown that diverse genetic and molecular mechanisms are likely to explain heterosis, making it difficult to predict its emergence and amplitude from parental genotypes alone. In this study, we examined a model of physiological dominance initially proposed by Sewall Wright to explain the nonadditive inheritance of traits like metabolic fluxes at the cellular level. We evaluated Wright’s model for two fitness-related traits at the whole-plant level, growth rate and fruit number, using 450 hybrids derived from crosses among natural accessions of A. thaliana. We found that allometric relationships between traits constrain phenotypic variation in a nonlinear and similar manner in hybrids and accessions. These allometric relationships behave predictably, explaining up to 75% of heterosis amplitude, while genetic distance among parents at best explains 7%. Thus, our findings are consistent with Wright’s model of physiological dominance and suggest that the emergence of heterosis on plant performance is an intrinsic property of nonlinear relationships between traits. Furthermore, our study highlights the potential of a geometric approach of phenotypic relationships for predicting heterosis of major components of crop productivity and yield.

ASSET DYNAMICS, LIQUIDITY, AND INEQUALITY IN DECENTRALIZED MARKETS

The Kiyotaki and Wright model has exerted a considerable influence on the monetary search literature. We argue that the model also delivers important insights into a broader range of macroeconomic and development issues. The analysis studies how market frictions and the liquidity of assets affect the distribution of income. Experiments illustrate how the economy adjusts to shocks to asset returns and to the matching technology. They also deal with long‐run transition. An experiment interprets the reversal of fortune hypothesis as a situation in which an economy with a low‐return asset takes over a similar economy with a high‐return asset. (JEL C61, C63, E41, E27, D63)

Prediction of the learning curves of 2 dental CAD software programs

Statement of problemDental clinical procedures are being replaced by digital workflows. Therefore, the time necessary to learn dental computer-aided design (CAD) software to achieve a change in the digital workflow should be evaluated. PurposeThe purpose of this study was to predict the learning curve according to the type of dental CAD software with the Wright model and to determine the rate of improvement in the learner’s working time with iterative learning. Material and methodsA total of 40 participants with various degrees of experience with dental computer-aided design and computer-aided manufacturing (CAD-CAM) systems were recruited. The 4 specified steps of a custom abutment design were performed with 3DSystem CAD software (Daesung) and exocad DentalCAD (exocad GmbH) software and were repeated 3 times in stages. The times were analyzed with repeated-measures 1-factor and 2-factor analyses. The learning time for 300 design iterations was estimated by applying the Wright model formula, and the 300-repetition times were analyzed with the Mann-Whitney U test (α=.05). Resultsexocad had a longer mean learning time than the 3DSystem. The overall change with repeated learning was significantly different (P<.001), and all differences were found in the first to third iterations. Software-dependent differences were also observed (P=.005). The Mann-Whitney U test also revealed a significant difference between the 2 software programs (P=.015), but no significant difference was found after the 56th iteration (57th iteration: P=.051). ConclusionsAs the time reduction patterns for iterative learning differ depending on the type of CAD software, the learning curves may differ according to the type of software. As the operator’s skill increased through iterative learning, the differences in learning times between the software programs gradually disappeared.