Improvement of the Nonparametric Estimation of Functional Stationary Time Series Using Yeo-Johnson Transformation with Application to Temperature Curves

In this article, Box-Cox and Yeo-Johnson transformation models are applied to two time series datasets of monthly temperature averages to improve the forecast ability. An application algorithm was proposed to transform the positive original responses using the first model and the stationary responses using the second model to improve the nonparametric estimation of the functional time series. The Box-Cox model contributed to improving the results of the nonparametric estimation of the original data, but the results become somewhat confusing after attempting to make the transformed response variable stationary in the mean, while the functional time series predictions were more accurate using the transformed stationary datasets using the Yeo-Johnson model.

Individual growth profiling improves growth modelling in the geoduck clam Panopea generosa

Contemporary modelling of growth based on shell-length to terminal age (SLTA) in long-lived clams is subject to inaccuracies as a consequence of low representation of early age classes in population samplings. To increase early age representation and improve growth modelling, we implemented an approach that used individual growth profile (IGP) data recorded in shells of the Pacific geoduck (Panopea generosa). We compared IGP against SLTA and a combination of both IGP + SLTA data through a multi-model approach for the southernmost known P. generosa population. The most parsimonious model for both IGP and IGP + SLTA data sets was the Schnute model, with L∞ = 127.9 and 122.5 mm, respectively, with the asymptotic phase attained at ∼15 years. For SLTA data alone, the most parsimonious was the Johnson model, with L∞ = 161.6 mm reaching the asymptotic phase at >25 years. In terms of performance, the IGP and IGP + SLTA data sets informed individual growth models with stronger relationships (r2 > 0.9) and higher modelling efficiency (ME > 0.9) than those fitted to SLTA alone (r2 = 0.51; ME = 0.51). The results demonstrate that IGP yields reliable information from relatively few organisms, improves the biological knowledge of the population, and increases the accuracy of parameter estimates for better fishery management.

Individual growth analysis of the Pacific yellowlegs shrimp Penaeus californiensis via multi-criteria approach

Length-frequency data of juveniles and sub-adults of Penaeus californiensis were analyzed, collected from January 2002 to January 2003 in the Agiabampo lagoon system and adjacent marine coastal zone. Six models were parameterized with four criteria, in addition to a mixed criterion (fat-tail and depensatory), to estimate the parameters that best fit the growth curve. The model that best fit was the Johnson model with the mixed criterion in females and males: k = 6.02 (5.93-6.12); L∞ = 188.8 (186.3-191.8); t0 = 0.0221 (0.0207-0.0234); and: k = 8.98 (8.85-9.12); L∞ =153.3 (151.7-155.0); t0 = 0.0386 (0.0378-0.0394), respectively. The conclusion is that: 1) the mixture approach found in this study as best leads to the application of a very high-performance objective function to analyze individual length-at-age variability, 2) shows that the best model to describe the growth trajectory of P. californiensis in marine and estuarine environments is a sigmoid curve with an inflection point near to cero age (Johnson model).

Multiphysics Modeling of Fabrication Methods’ Effect on UO2-BeO Composite Fuels’ Performance

UO2-BeO is one of the most promising accident tolerant nuclear fuels due to its excellent thermal conductivity compared to pure UO2 fuel. Two different UO2-BeO fabrication methods have demonstrated the capability to fabricate enhanced thermal conductivity UO2-BeO composite fuels and improve fuel performance. In one method, BeO is continuously distributed around UO2 grains while BeO is dispersed in the UO2 phase in the other method. In the former type, BeO is considered as matrix and UO2 as dispersed particle. However, in the later type, BeO is considered as dispersed particle and UO2 as matrix. To calculate the thermal conductivity of UO2-BeO composite, Hasselman-Johnson model has been applied, which shows good agreement with experimental data. In this model, it includes the influence of thermal conductivity of matrix and particle, volume fraction of particle, radius of particle and the interfacial thermal conductivity between matrix and particle. To balance the improvement of thermal conductivity and enrichment of UO2, a UO2-BeO composite fuel with 10% volume fraction of BeO has been chosen. Besides, the grain size of matrix should be noticeable smaller than particle to relax thermal stress which may cause micro-cracks and destruction, leading to the grain sizes of UO2 in two types being distinctive, and resulting in very big effect on fission gas release. In the paper the thermal conductivity has been intensively studied as well as fuel performance in two different types of UO2-BeO fuels, and the two fabrication methods have also been compared to assess their applications in commercial reactors.

PENGEMBANGAN MODUL PEMBELAJARAN PENJUMLAHAN DAN PENGURANGAN BILANGAN BULAT DENGAN PENDEKATAN CTL BERDASARKAN KURIKULUM 2013

Penelitian ini bertujuan untuk mengembangkan modul pembelajaran penjumlahan dan pengurangan bilangan bulat dengan pendekatan CTL yang telah disesuaikan dengan Johnson. Model pengembangan yang digunakan dalam penelitian ini adalah model Plomp yang dibagi menjadi lima tahap. Desain pengembangan modul ini mengadopsi sampai tahap keempat. Instrumen penelitian dalam penelitian ini terdiri dari; (1) kuesioner untuk para ahli dan praktisi, (2) kuesioner siswa, (3) lembar observasi dan kuesioner, (4) salinan tes. Subyek penelitian ini adalah siswa kelas 4 SDN 4 Malasan. Pengembangan produk telah memenuhi kriteria valid, praktis, dan efektif. Persentase validitas mencapai 90, 46%. Sedangkan persentase ulangan harian 82, 35%, dan persentase respon siswa adalah 87, 5% dan ada satu subjek yang tidak dimasukan. Dalam hal kepraktisan, rata-rata hasil nilai validasi adalah 3, 6 (kriteria tinggi) dan pengisian skor kuisioner dari pengamat, yaitu 3, 5 (kriteria tinggi).

Dynamic behavior of the (3+1)-dimensional generalized Johnson model in a dusty plasma

In this paper, we study the (3+1)-dimensional generalized Johnson model, which can be used to describe the dust-ion-acoustic waves in a cosmic unmagnetized dusty plasma, and its perturbed model, which can be found in an unmagnetized dusty plasma for the electron temperature below the Curie temperature. (I) For the original model: Bilinear form and soliton solutions are obtained. Amplitude of the one soliton reaches the maximum when the equilibrium electron (ne0) and ion (ni0) densities take certain values which correspond withne0/ni0= 2. Overtaking and head-on interactions between the two solitons are given. (II) For the perturbed model: Phase projections are given numerically. Via the spectral analysis, two kinds of chaotic motions, i.e., the weak and developed chaos, are investigated. Largest Lyapunov exponents and power spectra are investigated to corroborate that those motions are indeed chaotic. Dynamic behavior of such a perturbed model varying with the external perturbation is different when the nonlinear term changes. With the damped term considered, two kinds of periodic motions are studied, and spectra of those periodic motions are also given. Through the comparison between the chaotic motions and periodic ones, possible chaotic or periodic motions in the perturbed model can be predicted.