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A two step approach combining the Gompertz growth model with genomic selection for longitudinal data

A two step approach combining the Gompertz growth model with genomic selection for longitudinal data

The two-step approach of growth model fitting and genomic selection on model parameters and on pre- dicted phenotype appeared to be a simple and reliable strategy. Despite that the Gompertz curve was not the true model used to simulate the data, the correlations between true and estimated breeding values at t600 were very high (Pearson and Spearman correlations above 0.93). The approach of estimating GEBVs for phe- notype at a time of interest using GEBVs of the three parameters and evaluating the Gompertz function could be beneficial when GEBVs are needed for different time points. In this study, the proportion of SNP affecting
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Altered Patterns of Fractionation and Exon Deletions in Brassica rapa Support a Two-Step Model of Paleohexaploidy

Altered Patterns of Fractionation and Exon Deletions in Brassica rapa Support a Two-Step Model of Paleohexaploidy

The two-step model for paleohexaploidy formation and fractionation (Lyons et al. 2008) suggests that two of the genomes came together first, and then the third genome was added some time later (Figure 6). The common way to form a hexaploid is between a diploid (2N) and a tetraploid (4N) cross, resulting in a triploid, which on doubling produces a hexaploid. If this were the case, two subgenomes could be in the same nucleus for a longer period of time (as a vi- able tetraploid) than the third, which is then relatively less fractionated than the first two. Additional support comes from the gene loss pattern between subgenomes I and II, where low-density regions of one of the two more fraction- ated genomes are compensated by less loss on the other, which indicates that the tetraploid genome (I + II) could be viable since most genes tend to have at least one copy (Wang et al. 2011).
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Numerical Study of Blast Initiation of Detonation Using a Two Step Chemical Kinetics Model

Numerical Study of Blast Initiation of Detonation Using a Two Step Chemical Kinetics Model

numerical simulation of the reactive Euler equation with a two-step chemical reaction model can predict no unique valve for the critical initiation energy. This fact is independent of the value of the activation energies of the two steps. The presented two steps model has the main drawback of a single step model that is both models represent only exothermic processes. In order to predict a real failure, the kinetic model must be able to capture the competition between chain branching and recombination reactions. Below about 1100 K, chain-branching reactions become ineffective and hence give a sudden decrease in the global reaction rate, which is an essential for true simulation of the critical initiation. This point, in fact, shows the route for the future research.
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A Space Time Finite Element Approximation of a Two Step Chemical Kinetics Model

A Space Time Finite Element Approximation of a Two Step Chemical Kinetics Model

Abstract In this paper we suggest a fully discretized problem of a model describing two-step chemical ki- netics. The model considered is a system of equations coupling Navier-Stokes equations with three non-linear reaction-diffusion equations. A space-time finite elements approximations are presented. The stability of the fully discretized problem is studied. Optimal error estimates are given.

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A two-step optimization model for quantifying the flexibility potential of power-to-heat systems in dwellings

A two-step optimization model for quantifying the flexibility potential of power-to-heat systems in dwellings

The two-step methodology will be applied to quantify the potential to absorb surplus electricity in year 2018. The quanti fi cation approach takes into account dimensions of: (i) time, related to the requests to absorb surplus generation, (ii) energy, related to the optimal quantity of surplus electricity absorbed, and (iii) cost, related to the price a pro- sumer is willing to accept for absorbing surplus generation. Therefore, four design cases are considered to reflect the frequency of requests for surplus electricity absorption: (1) Base case for a business as usual system using a boiler for heating and electricity imports to satisfy de- mand, here no requests are made, (2) Case A for surplus electricity absorption requests in summer, (3) Case B for surplus electricity ab- sorption in winter, and (4) Case C, an ideal case that assumes surplus electricity is available throughout the year. These cases are selected to determine the impact of request frequency and quantity of absorbed electricity on the Prosumer Price Signal (PPS), and number of active participants. Assumptions on technology prices and the energy market are provided in the Appendix.
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Role of recBC function in formation of chromosomal rearrangements: a two-step model for recombination.

Role of recBC function in formation of chromosomal rearrangements: a two-step model for recombination.

Since our experiments show that RecBC independent circle capture is associated with a normal frequency of donor site joining, we propose that the unactivated circles genera[r]

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Two Step Model for Sentiment Lexicon Extraction from Twitter Streams

Two Step Model for Sentiment Lexicon Extraction from Twitter Streams

To formalize all these assumptions we construct an undirected graphical model using extracted sen- timent word co-occurrence statistics. Each ex- tracted word is represented by a vertex in a graph and an edge between two vertexes is established in case if they co-occur together more than once in the collection. We drop all the edges where aver- age distance between words is more than 8 words. Our model by construction is similar to ap- proach based on the Ising spin model described in (Takamura et al., 2005). Ising model is used to describe ferromagnetism in statistical mechan- ics. In general, the system is composed of N bi- nary variables (spins), where each variable x i ∈
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One step and two step estimation of the effects of exogenous variables on technical efficiency levels

One step and two step estimation of the effects of exogenous variables on technical efficiency levels

The use of the scaling property to generate models was suggested by Simar, Lovell and Vanden Eeckaut (1994). There is nothing sacred about this property, and it is ultimately an empirical matter w hether models generated using it fit the data. However, it has some attractive features. The first of these is that it captures the idea, which we find intuitively reasonable and appealing, that the shape of the distribution of u is the same for all firms. The scaling factor h(z, δ ) essentially just stretches or shrinks the horizontal axis, so that the scale of the distribution of u changes but its underlying shape does not. By way of contrast, consider the KGMHLBC model, which does not have the scaling property. Suppose for simplicity that σ 2 = 1. If the pre-truncation
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Well-Characterized Monoclonal Antibodies against Cell Wall Antigen of Aspergillus Species Improve Immunoassay Specificity and Sensitivity

Well-Characterized Monoclonal Antibodies against Cell Wall Antigen of Aspergillus Species Improve Immunoassay Specificity and Sensitivity

antibodies, respectively, for the development of a two-step antigen-capture ELISA. This combination produced the high- est sensitivity of detection of the experimentally induced anti- genemia among the various combinations of MAbs. In rabbits infected with A. fumigatus and A. flavus, the most common agents of aspergillosis, our two-step assay detected an infec- tion-related antigen increase as early as 1 day following estab- lishment of the infection and continued to detect increasing amounts of antigen as the infection progressed. The amount of detectable antigen over time was also consistent with disease progression in rabbits infected with A. niger, A. nidulans, and A. terreus. The assay could detect transient antigenemia in A. niger-, A. nidulans-, and A. terreus-infected rabbits weakly, even though the assay yielded a high sensitivity for the detection of the culture filtrates from the three species. Comparison of the commercial one-step ELISA (the Platelia Aspergillus assay) with our two-step ELISA by using an experimental animal model of IA infection revealed similar sensitivities of detection in A. fumigatus-infected rabbits over time; the sensitivity of the one-step ELISA was higher than that of the two-step ELISA for A. flavus-infected rabbits.
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Two-step semiparametric empirical likelihood inference

Two-step semiparametric empirical likelihood inference

are the nuisance parameters. This approach is slightly different from the one in [74, 70], who proposed a nonparametric imputation method by sampling from a smoothed nonparametric estimator of the distribution of W given X and D = 0. Inference with this nonparametric imputation may be sensitive to the number of draws performed. Our approach overcomes this problem by imputing directly s and treating the imputation as a nuisance parameter in our semiparametric model. As shown in [74], our method is strictly more efficient than that based on imputing W with a finite number of draws, with the efficiency gap between these two procedures going to zero as the number of draws goes to infinity. Nevertheless, our main contribution in this example is not the nonparametric imputation of s, but rather obtaining distribution-free semiparametric EL inference without undersmoothing. [74], Lemma 1, provided sufficient conditions under which (2.5) holds with
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One step and Two step Classification for Abusive Language Detection on Twitter

One step and Two step Classification for Abusive Language Detection on Twitter

In this research, we aim to experiment a two- step approach of detecting abusive language first and then classifying into specific types and com- pare with a one-step approach of doing one multi- class classification on sexist and racist language. Moreover, we explore applying a convolution- al neural network (CNN) to tackle the task of abusive language detection. We use three kinds of CNN models that use both character-level and word-level inputs to perform classification on dif- ferent dataset segmentations. We measure the per- formance and ability of each model to capture characteristics of abusive language.
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Two-Step Machine Translation with Lattices

Two-Step Machine Translation with Lattices

Deneefe et al. (2008) overcome the vocabulary sparseness in Arabic-English MT by using input word lattices of mul- tiple source analyses of test sentences. The use of lattice in our work is more similar to the approach used by Costa- juss`a et al. (2007); their SMR (Statistical Machine Reorder- ing) model is split into two steps where the SMT system in the first step performs the translation from source S to S’, producing weighted output word graphs consisting of mul- tiple reorderings of source sentences. The system on the second step takes the weighted reordering graphs and pro- duces final translations.
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Optimization of A Two-Step Method to Synthesize Azelaic Acid from Oleic Acid

Optimization of A Two-Step Method to Synthesize Azelaic Acid from Oleic Acid

The resulted data was analyzed by RSM using Minitab 17 software to form the relationship between variables that can be determined by regression analysis. The significant variables then were defined using Analysis of Variance (ANOVA). ANOVA implicated Fischer's test to estimate the overall significance of the model, associated 'P' values and determination coefficient R 2 was used to determine

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Two-step Methods for Differential Equation Models.

Two-step Methods for Differential Equation Models.

error needs to be accounted in the estimates. Secondly, their approach is based on a sufficiently smooth criterion function, but the criterion function for the quantile function is even discontinuous. We therefore modify our approach using a sequence of smooth cri- terion functions approximating the one for the quantile function. Thus two modifications of the results of Yohai and Maronna [54] are needed: allowing a sequence of criterion functions instead of a fixed one and letting the model to be slightly misspecified in that the true distribution does not belong to the model but the approximation error decays to zero sufficiently fast. Both modification requires carefully dealing with the terms arising due to the approximations to the criterion function and the truth.
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Destination segmentation: a recommended two-step approach

Destination segmentation: a recommended two-step approach

To validate the model, the tourists were sorted based on the month of when the survey was collected. The month was considered the most effective option as it enabled both data sets to contain tourists from both the high (e.g. Christmas period) and low seasons (e.g. mid-year). Combining months also ensured that month of data collection did not bias the sample. Three odd-numbered months (n = 253) and three even-numbered months (n = 246) were chosen to split the file evenly. As can be seen from Table 2, both models produced a similar BIC value, BIC change and ratio of change. It was identified that the size of the segments varied very little. It was also noted that the split files accurately represented the final solution with only minor changes identified. On this basis, it was concluded that the three-cluster solution was validated for this study (Hair et al. 2006).
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Two step translation with grammatical post processing

Two step translation with grammatical post processing

Our two-step translation is essentially the same setup as detailed by Bojar and Kos (2010): (1) the English source is translated to simplified Czech, and (2) the simplified Czech is monotonically trans- lated to fully inflected Czech. Both steps are sim- ple phrase-based models. Instead of word forms, the simplified Czech uses lemmas enriched by a sub- set of morphological features selected manually to encode only properties overt both in English and Czech such as the tense of verbs or number of nouns. Czech-specific morphological properties indicating various agreements (e.g. number and gender of ad- jectives, gender of verbs) are imposed in the second step solely on the basis of the language model.
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A Two-Step Method for Damage Identification and Quantification in Large Trusses via Wavelet Transform and Optimization Algorithm

A Two-Step Method for Damage Identification and Quantification in Large Trusses via Wavelet Transform and Optimization Algorithm

frequencies and mode shapes is investigated in [15] where Charged System Search (CSS) algorithm and Enhance Charged System Search (ECSS) are utilized to search for global optimum. In [16], the problem of damage detection using modal data is solved via CSS optimization algorithm and their proposed method is also validated by using three numerical examples. The problem of damage detection is solved applying frequencies and mode shapes of structures via the model updating technique using Magnetic Charged System Search (MCSS) and PSO in [17]. By utilizing natural frequencies and mode shapes to generate an Objective Function (O.F), a damage detection method based on model updating is proposed in [18] where the optimization problem is solved by continuous Ant Colony algorithm. The ABC optimization algorithm is chosen to be the optimizer to solve the damage detection problem in [19, 20] in which the authors develop an O.F by a combination of natural frequencies and modal shapes of the structure. In [21] the authors detect damages of truss structures by applying simplified Dolphin Echolocation (DE) algorithm. The O.F in the mentioned paper is formed based on natural frequencies and mode shapes of the structure. Despite the fact that model updating is regarded as one of the most effective methods of damage localization and quantification, it has one major drawback. When the number of variables considerably increases in the inverse problem, it either diverges or converges to wrong results. To tackle this problem, generally, two-step approaches are employed. To provide an illustration, it can be referred to [22] in which a two-step method is presented for damage localization and quantification in linear-shaped structures via Grey System Theory (GST) and an
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On the Analysis and Design of the Locust Olfactory System

On the Analysis and Design of the Locust Olfactory System

Unlike PNs, KCs respond very sparsely to odors and their individual baseline activity is ~ 1 spike every 30 s on average (Perez-Orive et al., 2002). Hence, significant effort was made to find KCs that responded to some at least of the odors in our panel prior to initializing an experiment. Due to the large number of conditions in our experiments, we did not (nor did we wish to) pre-test all 44 stimuli. Rather, we searched for responsive KCs by presenting the eight monomolecular odors; we selected a recording position from which some spikes could be recorded in response to any one of these stimuli. Due to the rarity of KC spikes, KC-spike cluster models were defined using all trials (usually ~ 50 conditions, 7 trials each, 14 s per trial). The condition in the middle of the set was used to calculate the noise covariance matrix (Pouzat et al., 2002). The threshold was set typically at 4–5 times each channel’s signal SD. The model generated by this method was refined using criteria identical to those used with the PN data. Stability over the course of the experiment was assessed after sorting and was based on a stable baseline firing-rate over the course of the experiment.
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Models for Patch-Based Image Restoration

Models for Patch-Based Image Restoration

3.1. Belief Propagation. For acyclic graphs, the marginal distributions can be calculated e ffi ciently and exactly by a local message passing algorithm known as belief propagation (BP) [16]. In the case of graphs with cycles, the BP algorithm is not exact. The iterative version of BP algorithm produces beliefs which do not converge to true marginals. But, it has been empirically shown that loopy BP produces excellent results for several hard problems. Recently, Yedidia et al. [19] established the link between the fixed points of belief propagation algorithm and stationary points of the “variational free energy” defined on the graphical model. This important result sheds more light on the properties of loopy BP approximation.
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Two-step LASIK after penetrating keratoplasty

Two-step LASIK after penetrating keratoplasty

Many factors such as the size, curvature, and thickness of the corneal transplant, the underlying disease for the PK, preoperative refraction, the trephination technique, the type of suture, size and alignment of the corneal flap, whether the complete transplant is included in the lamellar flap or not, location of the hinge, the kind of mikrokeratome, and the used settings (advance rate, vacuum), the excimer laser and the chosen ablation profile as well as healing processes which vary among patients affect the refractive outcome of LASIK after PK. The interactions between these fac- tors are to a great extent still unknown. Keratotomy causes biomechanical changes in the cornea after PK and these are unpredictable. Despite the small patient sample of this study and its limited validity we share the opinion of Alió and colleagues 30 and Kwitko and colleagues 33 and favor a two-step
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